18-Nov-18 01:29 AM gripe gripe I still have an oil-soaked foreline to completely dismantle, clean, recharge, and reassemble. ugh 18-Nov-18 01:29 AM Turbos are hard 18-Nov-18 01:30 AM An engineer friend of mine had a dp backstream into a column earlier this weak. The valve over setpoint was set to atmosphere. 18-Nov-18 01:30 AM Ironically he had vented the column to clean other bits of oil out... And it back streamed when he pumped it back down. 18-Nov-18 01:30 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/2018-11-15-C2F5E.png 18-Nov-18 01:32 AM oooops 18-Nov-18 01:32 AM The lab had an individual in it known to twiddle with potentiometers that he shouldn't touch. 18-Nov-18 01:32 AM I have no vacuum control system whatsoever right now, so it's all kind of a carefully-choreographed dance of connecting and disconnecting alligator clips and watching analog meters & oscilloscope traces 18-Nov-18 01:33 AM Lol yeah. My sem is that way 18-Nov-18 01:33 AM it has an automatic system, but I dont trust it 18-Nov-18 01:33 AM so I do it myself 18-Nov-18 01:33 AM (its not like one of the switches I have to use to rough down is right next to the DP isolation valve or anything) 18-Nov-18 01:35 AM The last semi-functional 'scope I was looking at is, uh. I haven't looked at it in depth but I am led to believe the entire column's gotten soaked through with oil from .. something. 18-Nov-18 01:35 AM I imagine the cleanup job, assuming that happens, will be.. fun 18-Nov-18 01:36 AM Really thats kind of surprising 18-Nov-18 01:38 AM It may have been some kinda DP suckback incident 18-Nov-18 01:38 AM that particular scope has done a few.. very exciting things resulting in hard shutdowns 18-Nov-18 01:38 AM Ouch 18-Nov-18 01:38 AM I know that my ISI had the worlds sketchiest anti suck back system 18-Nov-18 01:38 AM My jeol is a bit better 18-Nov-18 01:38 AM As for cleaning a SEM column out, procedures vary depending on if it is a system with a column liner or discrete sections of optics that you have to pull out 18-Nov-18 01:38 AM if it has been back streamed then you pretty much have to clean everything 18-Nov-18 01:46 AM Joined the server. 18-Nov-18 01:46 AM o/ 18-Nov-18 01:46 AM meow 18-Nov-18 01:46 AM sweet channel av 18-Nov-18 01:47 AM yeah i'm mostly not involved in any of that scope's maintenance or logistics besides having drawn a heart on it and waved a geiger counter around it 18-Nov-18 01:47 AM bUt we'll see where things go 18-Nov-18 01:47 AM they got first light recently so 18-Nov-18 01:48 AM Apertures are the hardest to clean well 18-Nov-18 01:48 AM Well if you have a beam and reasonable resolution then you should be fine 18-Nov-18 01:48 AM Contamination usually shows up as excessive stagmation or probe skipping 18-Nov-18 01:48 AM also a contaminated systems performance will degrade as you reduce beam kv 18-Nov-18 01:50 AM @whitequark yeah the avatar is Goals As Hell 18-Nov-18 01:50 AM that makes sense yeah 18-Nov-18 01:50 AM by 'first light' i mean they got a spherical-looking glow on the display instead of scanlines or CRT eigengrau 18-Nov-18 01:50 AM so who knows >.> 18-Nov-18 01:51 AM You can do some stuff to figure out where the contamination is, but that an easier process in a TEM where you can literally project the inside of the column on the screen if you are clever with optics 18-Nov-18 01:51 AM thats good 18-Nov-18 01:51 AM if its just a circle then that's probably to much condenser current 18-Nov-18 01:51 AM or way way out of focuse 18-Nov-18 01:51 AM or bad gun alignment 18-Nov-18 01:51 AM or wrong detector/lens program 18-Nov-18 01:51 AM but probably condenser current 18-Nov-18 02:11 AM Joined the server. 18-Nov-18 02:11 AM Good morning and greetings from germany 18-Nov-18 02:17 AM Also good but early morning from the us! 18-Nov-18 02:18 AM Thanks! 18-Nov-18 02:18 AM Adam, you seem to have the most practical experience here, have you ever worked with GM cryocoolers? 18-Nov-18 02:19 AM No only cryo stuff I have done is ln2 bassed 18-Nov-18 02:19 AM Ah well 18-Nov-18 02:19 AM Maybe you've seen my problem on twitter ^^ 18-Nov-18 02:20 AM If you have questions though I know people who I am pretty sure have built them from scratch 18-Nov-18 02:20 AM I can't find any information on critical dimensions of the regenerator 18-Nov-18 02:21 AM Fixing the destroyed bit you posted on twitter? 18-Nov-18 02:21 AM Yep 18-Nov-18 02:21 AM the fragments are big enough to measure everything and rebuild it, but some things don't add up 18-Nov-18 02:23 AM Oh hey! 18-Nov-18 02:24 AM Guten morgen! 18-Nov-18 02:24 AM guten abend :3 18-Nov-18 02:24 AM I technically should be asleep, it's 2 AM >.> 18-Nov-18 02:25 AM sleep is overrated 18-Nov-18 02:26 AM What model of GM cryocooler, btw? 18-Nov-18 02:26 AM Leybold RGD 510 18-Nov-18 02:26 AM the thing is huge... 18-Nov-18 02:26 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181118_112755-4F776.jpg 18-Nov-18 02:30 AM Oh wow it's on conflat too :O 18-Nov-18 02:31 AM What critical dims are you missing? 18-Nov-18 02:32 AM the second stage is held in the first one with a small pin, right now it fits nicely, but the end is broken off, if there was any more material the holes for the pin wouldn't line up 18-Nov-18 02:32 AM Yep, it's CF100 18-Nov-18 02:33 AM so cf6 18-Nov-18 02:34 AM damn you and your weird units 18-Nov-18 02:35 AM It super trips me up that I can occasionally find silly-cheap conflat kit on ebay by searching for the inner diameter 18-Nov-18 02:35 AM '6" vacuum gate valve'? all $>1000. '4" vacuum gate valve'? the HVA pneumatic gate valve i got (and then broke) was $70 18-Nov-18 02:35 AM and, yes, in the former and latter case, the same kinds of products show up 18-Nov-18 02:35 AM unfortunately i doubt i'm gonna find another one that cheap, but even still, they're like >$200.. >.> 18-Nov-18 02:38 AM I have seen a couple go cheap in the past 18-Nov-18 02:38 AM I really envy you for what you can get from ebay.com, ebay.de is mostly broken things for way too much money 18-Nov-18 02:38 AM and shipping + customs from the usa adds like 100€ 18-Nov-18 02:39 AM Yeah there are certain advantage to being us based 18-Nov-18 02:39 AM but I can't complain, not with the things I get from my scrap yard 18-Nov-18 02:39 AM I was at a place yesterday that literally had barrels of vacuum scrap 18-Nov-18 02:40 AM want! 18-Nov-18 02:40 AM no you dont 18-Nov-18 02:40 AM it was really vacuum scrap 18-Nov-18 02:40 AM oh :/ 18-Nov-18 02:40 AM manufactuing goofs 18-Nov-18 02:43 AM I always take them if I can, most of them can be fixed on the lathe 18-Nov-18 02:43 AM at least the ones I've found so far 18-Nov-18 02:43 AM I honestly wish I had more machine shop capabilities >.> 18-Nov-18 02:43 AM that's kind of a blocking thing for me, sorta. i'm restricted to adrenaline-packed ebay hunting and it's hard to get stuff anywhere close to what materials and labor would be if i could do it myself 18-Nov-18 02:44 AM yep, a lathe is worth its weight in gold 18-Nov-18 02:44 AM that, and a 3D printer 18-Nov-18 02:44 AM get a small one, that's sufficient for most work 18-Nov-18 02:46 AM yeah, i'm really thinking about one of those lithographic resin printers 18-Nov-18 02:46 AM i would love to find a vacuum-safe resin material 18-Nov-18 02:46 AM 'cos internal voids are not a good time for anyone 18-Nov-18 02:46 AM and i'm already in 'outgassing is dangerous' territory 18-Nov-18 02:47 AM Yeah no I had to do sem on some 3d printed stuff one time and damn 18-Nov-18 02:47 AM those virtual leaks 18-Nov-18 02:47 AM it was some metal prints and it was not pretty 18-Nov-18 02:48 AM I've got some metal 3D printed parts here, they look like a big piece of sponge 18-Nov-18 02:49 AM Ended up just having to use a really small chunk 18-Nov-18 02:49 AM yeah pretty much 18-Nov-18 02:49 AM and when you zoom in they look like a bunch of small sponges 18-Nov-18 02:51 AM I've never seen a SLA print irl before, but I'd imagine that FDM would actually be best for high vacuum work? 18-Nov-18 02:51 AM I think sla with the right resin is probably really good 18-Nov-18 02:52 AM vacuum laser sintering seems like it could be an interesting option 18-Nov-18 02:52 AM i suspected at one point my turbo came out of a laser sinterer 18-Nov-18 02:52 AM the e- beam stuff? 18-Nov-18 02:52 AM yeah like that too 18-Nov-18 02:52 AM I'll try to get my hands on a SLA print and measure outgassing rate, compared to regular PLA FDM 18-Nov-18 02:53 AM i mean pla is already a no go 18-Nov-18 02:53 AM is it? 18-Nov-18 02:53 AM yeah 18-Nov-18 02:53 AM its pla 18-Nov-18 02:53 AM good fdm might work 18-Nov-18 02:54 AM what's the issue with PLA, high vapor pressure? 18-Nov-18 03:02 AM yeah out gassing in general 18-Nov-18 03:02 AM i mean it depends on what vac you want to get to 18-Nov-18 03:04 AM I mean, my current chamber will become a fusor, so high vacuum is not an issue 18-Nov-18 03:04 AM I'm trying to get a new one for some HV / XHV fun 18-Nov-18 03:04 AM but of course, any plastic in a 30 keV plasma is not a great Idea... 18-Nov-18 03:05 AM Well vacuum cleanliness is 18-Nov-18 03:05 AM You dont want your reaction poisoned 18-Nov-18 03:05 AM You want to pull your fusor down as far as it can go then back fill with d2 18-Nov-18 03:05 AM if you are going for maximum output or something like that 18-Nov-18 03:06 AM maximum output it is, I "need" / want a good neutron source at home 18-Nov-18 03:07 AM also the fact that outgassing in the molecular flow regime means 'every exposed surface experiences collisions with and potentially accumulates whatever that outgassing thing is' 18-Nov-18 03:07 AM afaik 18-Nov-18 03:07 AM like there's some manner of transport function at work there surely but 18-Nov-18 03:07 AM The higher your partial pressure of d2 you have, the more efficient thus higher flux you can get 18-Nov-18 03:07 AM if you can hit 60-70 kv and go beam on target hybrid you can get north of 10^7 isotropic 18-Nov-18 03:09 AM I can't seem to find a proper HV power supply for that voltage, my current one "only" does 30 kV 18-Nov-18 03:09 AM Build your own cw 18-Nov-18 03:10 AM but 30 kV @ 100 mA, so I might be able to go lower in pressure and use ion sources for higher current 18-Nov-18 03:10 AM Nah you want voltage 18-Nov-18 03:10 AM the highest output nuetron sources in the word use nA. 18-Nov-18 03:11 AM I know :/ 18-Nov-18 03:11 AM I was thinking about selling my PS, but for that to make sense I'd need an offer for a higher voltage one 18-Nov-18 03:11 AM It is acutally really hard to get anything good >10 kV here 18-Nov-18 03:11 AM I guess I'll have to diy 18-Nov-18 03:24 AM 2 or 3 nst and some hv caps and dioeds off of ebay plus a variac works pretty well 18-Nov-18 03:28 AM Building a HV supply is definately not impossible for me, it's just not the highes of priorities ^^ 18-Nov-18 03:28 AM I've got projects piling up here, gotta start finishing some of them >.< 18-Nov-18 03:29 AM You have 50hz dont you 18-Nov-18 03:29 AM Yep 18-Nov-18 03:29 AM thats going to make it 1/6th more interesting 18-Nov-18 03:29 AM I've got a big ferrite core and a couple of kg of 0.3mm magnet wire, if I DIY it will be a smps 18-Nov-18 03:31 AM but waltons are so much fun 18-Nov-18 03:32 AM why not both? 18-Nov-18 03:32 AM I totally forgot about that, my local particle accelerator will close down next year, maybe I'll get a ps there 18-Nov-18 03:33 AM can i come and assist with decommissioning? 18-Nov-18 03:34 AM I'll see what I can do 18-Nov-18 03:34 AM funny thing is, the copany I started working at does nuclear decon and will dismantle parts of the accelerator 18-Nov-18 03:34 AM soo much XHV stuff... 18-Nov-18 03:36 AM Oh what I would give... 18-Nov-18 03:36 AM sadly most parts are activated, so not even I might get a chance.... 18-Nov-18 03:37 AM oh 18-Nov-18 03:37 AM a big accelerator 18-Nov-18 03:37 AM 30 MeV Tandem 18-Nov-18 03:37 AM I mean im good with a bit of un 2903 18-Nov-18 03:38 AM they had a student who turned on the beam and then started opening the blinds one by one 18-Nov-18 03:38 AM And how did that go? 18-Nov-18 03:39 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180913_161926-2254E.jpg 18-Nov-18 03:40 AM ok then 18-Nov-18 03:40 AM as well as one would expect 18-Nov-18 03:41 AM and all of those parts have do be discarded somewhere 18-Nov-18 03:42 AM well what is the stuff north of the extractor like? 18-Nov-18 03:42 AM north of the extractor? 18-Nov-18 03:42 AM do you mean the beamline itself or the accelerator? 18-Nov-18 03:43 AM the stuff that is not in the direction the source is facing 18-Nov-18 03:44 AM that's all fine 18-Nov-18 03:44 AM the accelerator is a huge 15 MV van de graaf under ~6 bar SF6, if anything goes wrong it might arc over, but that's no problem 18-Nov-18 03:55 AM That fun 18-Nov-18 03:55 AM Biggest I have been around is mev. I wish I actually got to dig into it 18-Nov-18 03:56 AM If you're ever in munich (and the accelerator is still there) I can organize a visit 18-Nov-18 03:57 AM looks up flights 18-Nov-18 03:58 AM the whole campus there is awesome 18-Nov-18 03:58 AM A fission reactor as neutron source, the tandem acc., a fusion reactor (With fun specs like 8 MW RF heating and stuff like that), a petawatt laser for wakefield experiments, a center for ultralow temperature research and basically everything else one can imagine 18-Nov-18 04:33 AM Joined the server. 18-Nov-18 04:33 AM Hi 18-Nov-18 04:38 AM Hey it’s Tom - also @fusorfusion on Twitter 18-Nov-18 04:49 AM Thanks for organizing this 18-Nov-18 04:53 AM hey c: 18-Nov-18 04:53 AM yeah we're slowly trying to pull folks in 18-Nov-18 04:53 AM it's technically almost 5 AM here so I'm about to crash for a bit 18-Nov-18 04:56 AM Sleep is the ultimate nootropic 18-Nov-18 04:56 AM Zeloof coming? 18-Nov-18 04:57 AM @AdamMcCombs I assume you've also zonked out, but: UN 2903? do you mean 2913? >.> 18-Nov-18 04:57 AM Possiblymaybe! Adam might've pinged him already. 18-Nov-18 08:47 AM How about inviting the whole dead gauges society? 18-Nov-18 11:34 AM A friend of mine would like to join here, too, he's definately a vacuum hacker. 18-Nov-18 11:34 AM He's currently building a fusor, has built a new casing for his TMP, etc. 18-Nov-18 11:34 AM what are the rules for new members? 18-Nov-18 12:36 PM @GigaSquirrel rules are that they follow the rules in #welcome. We want this server to be open to anyone interested in vacuum and related technologies 18-Nov-18 12:36 PM We actually almost called this server the Dead Guages Society 18-Nov-18 12:38 PM Great, I sent him a invite 18-Nov-18 12:38 PM what stopped you? ^^ 18-Nov-18 12:38 PM Joined the server. 18-Nov-18 12:39 PM Welcome 18-Nov-18 12:42 PM Hi! Had to train some recaptcha AI before responding ^^ 18-Nov-18 12:42 PM Another win for humanity against skynet 18-Nov-18 12:45 PM It was 3am 18-Nov-18 12:45 PM Oh from calling it tdgs 18-Nov-18 12:46 PM yep ^^ 18-Nov-18 12:47 PM We felt that we wanted a more descriptive name than a inside joke on Twitter. It was a tough choice, @qualia even had this great back story written up and everything 18-Nov-18 12:47 PM I'd love to read that story, eventhough the name didn't make the cut 18-Nov-18 12:49 PM I'm on mobile right now so I will see if I can pull it up when I get back to my computer 18-Nov-18 12:50 PM Joined the server. 18-Nov-18 12:50 PM Hello! 18-Nov-18 12:50 PM Hi! 18-Nov-18 12:50 PM Hi! 18-Nov-18 01:11 PM Joined the server. 18-Nov-18 01:11 PM Twins? 18-Nov-18 01:12 PM Holy F, it has taken me like 10minutes to join from my phone. Hi everyone! 18-Nov-18 01:13 PM Welcome... back I guess? ^^ 18-Nov-18 01:15 PM Hey, welcome 18-Nov-18 01:16 PM XD, back to the server II 18-Nov-18 01:16 PM I too want to read Mx's story! 18-Nov-18 01:16 PM I too want to read Mx's story! 18-Nov-18 01:21 PM Ahh, ok ok, I'll recover it after I shower. Also, good morning! 18-Nov-18 01:21 PM good evening 18-Nov-18 01:22 PM Evening here! So, is there a trip with vacuum nerds to be held somewhere next year in Munich? 18-Nov-18 01:22 PM 18-Nov-18 01:23 PM I wish 18-Nov-18 01:24 PM there are enough things to do here to fill at least a week 18-Nov-18 01:24 PM and once we're done in munich, we can go on to other sights, like the haigerloch nuclear pile 18-Nov-18 01:24 PM I might be traveling out that way next year for Revision (demoscene thing) and judging from the amount of Stuff To Do out there, I might try to stretch my stay-time a bit longer 18-Nov-18 01:24 PM ooo 18-Nov-18 01:27 PM Damn...lets see if I can get a job soon so I can go and bother you. 18-Nov-18 01:27 PM Btw, who here knows Zeptobars? 18-Nov-18 01:27 PM not me 18-Nov-18 01:27 PM oh my, those are some sexy die shots 18-Nov-18 01:29 PM Yeah. 18-Nov-18 01:29 PM I asked him if I managed to do something on a die before end of January, if he would like to post it as an april fools. Said "yes, of course". 18-Nov-18 01:34 PM That's quite the service! 18-Nov-18 01:37 PM (the service? I don't understand the phrase. ) 18-Nov-18 01:39 PM sorry, bad translation, I meant it is nice of him to do it that quick (I suppose taking die shots takes some time) or even accept "comissions" from others 18-Nov-18 01:40 PM Ah, well, anything I do by that time will be visible to the naked eye in any case. XD But I think it is okay as an April Fools joke. 18-Nov-18 01:43 PM so, what was the actual joke? 18-Nov-18 01:53 PM God damn it, I misread your first message, I thought you asked him to do something on a die >.< 18-Nov-18 01:53 PM guess I should go to sleep... 18-Nov-18 01:53 PM good night to everyone 18-Nov-18 02:16 PM Good night! 18-Nov-18 03:15 PM Joined the server. 18-Nov-18 03:22 PM Hey everyone! Thanks for the invite to this chat, really awesome to put together a group of vacuum enthusiasts to share resources! 18-Nov-18 03:52 PM Welcome! 18-Nov-18 04:21 PM Welcome! 18-Nov-18 04:40 PM I would suggest adding Connor Krukosky too. @AdamMcCombs 18-Nov-18 04:45 PM Yeah I sent him ban invite 18-Nov-18 04:47 PM Ban invite? Automatically kicked off before getting in. XD (I know, I know, it was a typo, but anyways...XD) 18-Nov-18 04:47 PM yup 18-Nov-18 04:47 PM I invited him just to ban him 18-Nov-18 04:51 PM Btw, the show&tell section, is just for you or everyone? 18-Nov-18 05:08 PM Oh yeah no I made a channel just for me to post cool photos and no one else 18-Nov-18 05:08 PM jk of course you can post stuff there 18-Nov-18 05:12 PM Joined the server. 18-Nov-18 05:13 PM Hey ceder 18-Nov-18 05:13 PM Hello Adam! 18-Nov-18 05:13 PM Thanks for the invitation. I may not have a lot to contribute -- am here mostly to learn. 18-Nov-18 05:14 PM No problem! This server is here for everyone 18-Nov-18 05:15 PM @CGrover don't underestimate what we can learn from you. 18-Nov-18 05:15 PM Also, welcome! 18-Nov-18 05:16 PM Thanks @Nixie. 18-Nov-18 05:16 PM Yeah if anyone has circuit problems @CGrover is a great person to ask 18-Nov-18 05:17 PM 18-Nov-18 05:38 PM @qualia I just finished reading the whole chat, if you need something machined, just ask. I might be of help (or not, as @mbretti19 knows. . Long story short, his pieces where ginormous for my lathe/mill). 18-Nov-18 05:41 PM If anyone want some really big vacuum hardware made im friends with the folks at thermionics 18-Nov-18 05:41 PM They have some big toys 18-Nov-18 05:41 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181116_125825-2DA43.jpg 18-Nov-18 05:45 PM You just wanna make some people cry. 18-Nov-18 05:46 PM Hey I was asking how much it would cost to rent out the back room for myself 18-Nov-18 05:46 PM Will you be able to? 18-Nov-18 05:48 PM I wish 18-Nov-18 05:48 PM Its a bit far away from a lot of the instruments I work on 18-Nov-18 05:51 PM Shame... I'm crossing fingers for a space just next to my flat. (at road level). 18-Nov-18 05:52 PM They had a lot of other toys. 2 cnc mills, 2 cnc lathes, 6 Bridgeport's, surface frinders 18-Nov-18 05:53 PM 18-Nov-18 05:54 PM horizontal mills, band saws, grinders, every type of leak detector, every type of welder, vacuum decontamination, high class clean rooms, massive pumping stations with 2000lps+ ion pumps. Basically everything. 18-Nov-18 05:54 PM and that was just one location 18-Nov-18 05:54 PM they have more shops in California 18-Nov-18 05:56 PM Hm...is there a detector for certain words? 18-Nov-18 05:56 PM Yeah. It me. 18-Nov-18 05:59 PM XD 18-Nov-18 05:59 PM Then I'll just cry 18-Nov-18 05:59 PM 18-Nov-18 07:01 PM I kinda wanna visit the high vacuum places around here 18-Nov-18 07:01 PM I'm like walking distance from Duniway and MDC and HVA.. 18-Nov-18 07:01 PM (... well, 15-30m drive..) 18-Nov-18 07:26 PM Yeah if you can get a tour. It's really cool to see everything thing they can bring to a project. 18-Nov-18 07:53 PM So I heard you like cryo pumps 18-Nov-18 07:53 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181116_114613-383D0.jpg 18-Nov-18 07:56 PM Joined the server. 18-Nov-18 07:56 PM Cryo pumps are cool 18-Nov-18 07:56 PM Well you got that right discord 18-Nov-18 07:57 PM :P 18-Nov-18 07:57 PM also holy crap that lathe 18-Nov-18 07:57 PM Yeah for real 18-Nov-18 07:57 PM my grandfather has one about that big... but not as beefy 18-Nov-18 07:57 PM guess its for lighter bigger work 18-Nov-18 07:57 PM he has a smaller machine thats pretty good though 18-Nov-18 07:57 PM uhg man I've been behind on my vacuum assembling stuff because of upcoming bill stuff... 18-Nov-18 07:57 PM worked 60+ hours this last week too 18-Nov-18 07:57 PM so been a bit below the internet radar lol 18-Nov-18 08:00 PM Yeah work can do that 18-Nov-18 08:00 PM Some of the weeks I do the coolest stuff im so busy I dont post it 18-Nov-18 08:12 PM Joined the server. 18-Nov-18 08:13 PM Hello once more 18-Nov-18 08:13 PM lol sorry about that, switched discord accounts. But hello again 18-Nov-18 08:13 PM I accidentally made two, but didn't confirm one. Should be deleted soon. XD 18-Nov-18 08:24 PM i've got a boat load of papers and resources in my library that I have collected over the years (several thousands of papers on over a hundred topics). Good collection of vacuum engineering papers and data. is it ok to zip the vacuum stuff and post it in the resources section? also if anyone has a particular topic of interest related to high voltage, plasma, pulsed power, and need reference material let me know and I can see if I have something on it in my files. Chances are I have come across it at one point or another. 18-Nov-18 08:38 PM there's a file size limit, so it might make more sense to host it somewhere 18-Nov-18 08:38 PM but i would say yeah go for it if it's ok to share 18-Nov-18 08:40 PM yeah, one of the folders is rather large. Ill give it a shot and see if it works 18-Nov-18 08:40 PM You get 8mb... 18-Nov-18 08:42 PM yeah nvm, my first folder on vacuum technology is about 100MB 18-Nov-18 08:42 PM I can host those on my google drive if you want, or we could start a wiki? 18-Nov-18 08:46 PM whatever is easiest. Just a suggestion if there is any interest. I spend a lot of my free time collecting and reading papers, so I have tons of resources available. figure there may be useful vacuum engineering related info for those who want/need it 18-Nov-18 08:48 PM Yeah, I will send you a link to upload the folder to 18-Nov-18 09:22 PM So question for @Applied_Ion and anyone else, what would you recommend for a high current 5kv ish argon ion gun? 18-Nov-18 09:23 PM in terms of what? commercial product, design? 18-Nov-18 09:23 PM what application? 18-Nov-18 09:23 PM and how high current? 18-Nov-18 09:23 PM also, CW or pulsed? 18-Nov-18 09:26 PM Im looking to build my own ion gun for a cross section pollisher, something like this https://www.hitachi-hightech.com/global/science/products/microscopes/sample-preparation/tem-stem/im4000plus.html 18-Nov-18 09:29 PM sounds awesome! let me look a bit more into it. What types of currents are you looking at? nA, mA? i'm assuming not in the amps range 18-Nov-18 09:30 PM Def not amps. You want a coherent ish beam, but manufactures aren't that forthcoming with current... 18-Nov-18 09:30 PM More current means faster etch time though 18-Nov-18 09:30 PM which I am interested in 18-Nov-18 09:30 PM My guess is its just a thermal ion source with an extractor and some basic lenses 18-Nov-18 09:31 PM i got some great resource books on ion sources, I can upload design pictures from the books. 18-Nov-18 09:31 PM duoplasmatron is probably out, way too hardcore for your application 18-Nov-18 09:32 PM Yeah for sure 18-Nov-18 09:32 PM yeah quick ish and dirty is good 18-Nov-18 09:32 PM its going to get dirty 18-Nov-18 09:34 PM how much power you got to run a gun? 18-Nov-18 09:34 PM also, preferred ionization source? rf, dc, filament? 18-Nov-18 09:34 PM Well the industrial units just plug into a wall soooooo.... 18-Nov-18 09:34 PM Dc or filament would be nice 18-Nov-18 09:34 PM makes chamber feedthrough easier. 18-Nov-18 09:34 PM Ok so im finding some specs on these, around 500uA discharge current, ~200uA beam current 18-Nov-18 09:34 PM The guns on these things are pretty small 18-Nov-18 09:37 PM oh, only microamps? that should be super easy, ive been looking through the hundreds of mA designs. 18-Nov-18 09:37 PM Yeah I want to polish a sample 18-Nov-18 09:37 PM not vaporize a sample:) 18-Nov-18 09:38 PM yeah, i usually am on the side of complete annihilation. fortunately microamp would be very easy to obtain 18-Nov-18 09:39 PM Yeah, as I said I'm probably going to go with a thermal or dc source and a bit of extraction with some static lens stuff 18-Nov-18 09:39 PM do you already have a feedthrough you are looking to use? 18-Nov-18 09:39 PM No not specifically 18-Nov-18 09:43 PM btw the book I am looking through now has an amazing range of ion sources and drawings. "Atom and Ion Sources" by L. Valyi, very good read. Got it for a few dollars used online, great reference if you can get a hold of it 18-Nov-18 09:43 PM are you also looking to use an electrostatic lens to have some beam diameter control as well? 18-Nov-18 09:49 PM Possibly. I the that the beam size is just intrinsic to the gun design in the oem systems, but I dont know what that size is 18-Nov-18 10:03 PM actually, this came up the other day in a discussion about ion sources. Andrew Seltzman has the designs posted for his ion source. its an anode layer ion source, very wide beam, very simple structure. No filament needed. currents up to a few mA 18-Nov-18 10:03 PM Yeah i was looking at that 18-Nov-18 10:04 PM beam may not be what you are looking for though, since it is more cylindrical output than a focused spot 18-Nov-18 10:04 PM I don't think its coherent enough to get good surface quality 18-Nov-18 10:04 PM yeah it doesnt have high coherence at all 18-Nov-18 10:04 PM It would work for flat milling but not cross section stuff 18-Nov-18 10:04 PM One of those with a small turntable would be interesting for a delayering device 18-Nov-18 10:06 PM I got to head to bed, but I will visit this again tomorrow. I'll look more through my resources and see if I can CAD up a few example topologies with dirt simple structure 18-Nov-18 10:06 PM what are your machining limits? 18-Nov-18 10:06 PM like do you have access to machine basic stuff? 18-Nov-18 10:07 PM Lath and mill, I can get cnc at thermionics but that's a day trip and some other logistics 18-Nov-18 10:08 PM lathe and mill would be plenty, way more than I have now! btw is this a personal project or for work? doesn't make a difference either way, just curious 18-Nov-18 10:08 PM but I will see if I can get some simple designs up and posted for reference to explore 18-Nov-18 10:09 PM Just a personal project 18-Nov-18 10:09 PM I want to do some ic cross section images 18-Nov-18 10:09 PM also, what is your aniticipated budget range? 18-Nov-18 10:10 PM I mean I'm going to cheap, but not zero 18-Nov-18 10:10 PM a few hundred not including the chamber and pumping system 18-Nov-18 10:10 PM ok, so this is a complete seperate system with its own chamber and pump? 18-Nov-18 10:11 PM Oh yeah 18-Nov-18 10:11 PM few hndred would be no problem, we can probably do it for cheaper, especially if you have access to machining yourself 18-Nov-18 10:13 PM At home I have a drill press, but lathe and stuff is not to bad to get 18-Nov-18 10:13 PM I also got access to SIMION at work, I could probably throw the design in and run a simulation for you as well. cant use it to make money for myself, but for a side project to help someone that should be fine 18-Nov-18 10:14 PM Yeah no problem 18-Nov-18 10:14 PM not that i would charge or anything, just saying it would be fine for non-product stuff 18-Nov-18 10:15 PM As with all my sem stuff i do on occasion do commercial stuff with it, but it's not why I am building it 18-Nov-18 10:18 PM no problem lol (my institute can be a real aggressive hawk about IP stuff, ive heard horror stories about the lengths they are willing to go to get credit for things developed with their resources, hence why I do everything open source with free software on my own lol.) if I actually had a ton of free money, simion would be awesome to have. there is a very powerful free ion beam simulation software called ibsimu, but it is horrible to get running. 18-Nov-18 10:18 PM ibsimu has an advantage however that it simulates ion beam extraction from plasmas, which is ideal for ion sources, but it is a text based simulator 18-Nov-18 10:23 PM I mean i have done a bit of mcnp stuff, but... 18-Nov-18 10:23 PM id like to learn mcnp, though its not really for ion optics 18-Nov-18 10:23 PM @AdamMcCombs don't get caught with the lathe and mill. They require a few extra accesories to get them running. Especially a bandsaw, measuring devices and endmills and other bits. 18-Nov-18 10:23 PM It is a slippery slope. 18-Nov-18 10:25 PM I know my way around a machine shop, they just are not my shops... 18-Nov-18 10:25 PM Ah, okay, okay. Nevermind then. 18-Nov-18 10:26 PM I think you fail to realize the easy with which i can get large quantities of industrial hardware and very low prices in the united states... 18-Nov-18 10:26 PM Right now its just a space thing though 18-Nov-18 10:28 PM Probably, sorry for that. I'm used to see people around me not understanding what a metal workshop requires. 18-Nov-18 10:28 PM (in spain owning a personal metal workshop is extremely rare, we don't have a culture of machining like england, for example.) 18-Nov-18 10:28 PM So I tend to err in the cautious side with everyone that I have not seen posting machining pics. 18-Nov-18 10:35 PM Yeah no I know how to properly tap holes with an adjustable wrench and a Bridgeport and another tap upside-down and to apply pressure 18-Nov-18 10:35 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/kHUQf9LsZvdxK1dEObW8W45ibGLVQPRt1vGS1vfPgf-CE2AE.png 18-Nov-18 10:35 PM Also a Jacobs chuck is key 18-Nov-18 10:38 PM 18-Nov-18 10:38 PM Well, sorry for underestimating your comprehension of the trade. (Not sorry for being cautious, though) 18-Nov-18 10:39 PM Oh no problem 18-Nov-18 10:39 PM Im not going to call my self a good machinist by any means... 18-Nov-18 10:43 PM Good enough for sure. I do suck at taping, for example. 18-Nov-18 10:43 PM oh man the number of taps I have lost in 316 stainless 18-Nov-18 10:43 PM Im always trying to do m2 and m3 stuff to 18-Nov-18 10:54 PM 18-Nov-18 10:54 PM I have one M1 tap, don't ask me why. 18-Nov-18 10:54 PM Correction, M1.2 tap and die. Still don't ask why. 18-Nov-18 10:54 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20181119_075712-D798C.jpg 19-Nov-18 12:20 AM yawn Good morning! 19-Nov-18 12:20 AM A new video by Krasnow is a great thing to wake up to 19-Nov-18 12:28 AM Yeah, quite interesting! 19-Nov-18 12:28 AM /morning!/ 19-Nov-18 03:04 AM Hi! Since you guys are already talking about machining here i have a short question, though its more market research related. I Have recently made a new housing for leybold TW190/20/20 cartridge pumps so they can be used for normal vac systems. Now i have two others interested in such housings and i wonder if you have the same kind of situation in the us? These Pumps go on ebay for around 200 bucks in perfect working condition and they are pretty modern devices including inverter. 19-Nov-18 03:04 AM Thats the prototype 19-Nov-18 03:04 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_6148-632D2.JPG 19-Nov-18 03:07 AM I'd buy one of those adapters, but you already know that ^^ 19-Nov-18 03:08 AM there is one tw290 on ebay.com for $300 19-Nov-18 03:08 AM with shipping the ones from germany also end up around that price 19-Nov-18 04:40 AM I got one of those too. 19-Nov-18 04:40 AM But, what is the question exactly? (I'm in EU, so as far as I understand it doesn't affect me) 19-Nov-18 04:40 AM (no, not exactly one of those, mine is a bit overkill more) 19-Nov-18 04:40 AM Mine is a TW250S. Would love to switch it for something smaller. (I mean, my vacuum chamber is 100*100mm round). Literally, I can use the pump as bottom endplate for the glass chamber. 19-Nov-18 04:47 AM the Pumps are not Standard kf / cf / iso, Georg is offering to make a new outer shell for it which has a normal flange 19-Nov-18 04:47 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20181119_134746-2EFC8.jpg 19-Nov-18 04:47 AM he's in the eu, too, the question is if someone in the usa would be intetested im that part, too 19-Nov-18 04:48 AM (Not the real montage, just putting things together) 19-Nov-18 04:48 AM oh 19-Nov-18 04:48 AM the ones being sold here look different, one sec 19-Nov-18 04:48 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_20181119-134909-AABCB.png 19-Nov-18 04:49 AM Hdmtf...they're so small... 19-Nov-18 04:49 AM Noone interested in a trade? 19-Nov-18 04:49 AM that's the tw290/20/20 19-Nov-18 04:50 AM a trade for what? 19-Nov-18 04:52 AM I am Half-kidding. I mean thst my turbopump is super big for my purpose/setup, and would love to trade it for a smaller one, since my chamber is so small. 19-Nov-18 04:53 AM I can offer you some if you're ok with dirt in the Rotor, broken bearings and completly terrible condition :P 19-Nov-18 05:05 AM Bahaha 19-Nov-18 05:05 AM Mine is in working condition. Would love to buy something broken from you at one point to have as display (like my turbine blade) 19-Nov-18 05:05 AM Btw, to whomever is awake, I'll livestream the semiconductor oven refurbishing in an hour. 19-Nov-18 05:08 AM I'd love to watch, but I'm sitting in a QM lecutre right now 19-Nov-18 05:08 AM shipping a broken tmp to you should not be a problem, what country are you in? 19-Nov-18 05:10 AM Spain, but I have literally zero money for this sort of thing right now. I am in survival-experimentation mode (skipping a night out in order to afford repair pieces, for example) 19-Nov-18 05:10 AM Don't worry, it is going to be just a re-coiling of the oven, nothing fancy at any level. 19-Nov-18 05:12 AM let me know if you want one 19-Nov-18 05:13 AM Once I get a job, and are out of the pit, will let you know Thanks 19-Nov-18 05:14 AM good luck with the jobhunt! 19-Nov-18 05:14 AM just sell some geiger counters on ebay, that's how I got my job 19-Nov-18 05:27 AM XD 19-Nov-18 05:27 AM I am considering on selling my hackaday supercon badge. It is not a valuable/collectors item, though. (Not gonna undersell it, in any case.) 19-Nov-18 05:27 AM I moved to a lesser techie zone of my country, do have backups, but would prefer to find something that uses my habilities. 19-Nov-18 05:31 AM electronical engineering / chip design? 19-Nov-18 05:32 AM Problem solving & production line improvement/toolbuilding. (Background is electronic product design) 19-Nov-18 05:32 AM The chip thing is totally me demonstrating it can be done by anyone without a background on it. 19-Nov-18 05:32 AM 19-Nov-18 05:32 AM I'll find something, I guess. 19-Nov-18 05:33 AM hm, if I remember correctly sharp does (did?) some design work in spain, but just for consumer electronics 19-Nov-18 05:34 AM Maybe, the problem is that I am now in southern spain. (Murcia). It is not known for being a tech place by any means. But there are some places nonetheless. 19-Nov-18 05:35 AM the boss from my last job bought some semiconductor stocks and a couple of meters from them 19-Nov-18 05:35 AM Interesting. 19-Nov-18 05:36 AM but that's pretty much everything I know about tech in spain ^^ 19-Nov-18 05:36 AM I am trying to find out if there is avaliable jobs in a state funded "maker lab" near (60km) me. I have the perfect set of skills to teach anything to anyone in there. 19-Nov-18 05:36 AM Awesome! 19-Nov-18 05:37 AM Yeah, would be incredible, but, as said, I am not sure there are job positions in there. 19-Nov-18 05:37 AM Will have to go in person and bother someone. 19-Nov-18 05:37 AM (instead of just trying to comunicate via internet.) 19-Nov-18 05:38 AM that's always better 19-Nov-18 05:38 AM Good luck! 19-Nov-18 05:38 AM Thanks! 19-Nov-18 05:39 AM and even if they are not actively looking for new employees, just show them why the should employ you anyways, maybe they didn't even consider starting their own semicon procuction line 19-Nov-18 05:40 AM Bahahahahahahahah. Yeah. My point is that my home workshop is already 10 times better than what they have right now. 19-Nov-18 05:40 AM 19-Nov-18 05:40 AM I have included the semicon thingy in my resumee, in any case. 19-Nov-18 10:25 AM mornin, folx 19-Nov-18 10:25 AM Good evening 19-Nov-18 10:26 AM I'm on the train to work, trying to puzzle out the design of some fault-resistant vacuum controller hardware 19-Nov-18 10:26 AM flowcharts and other things I've never been very good at 19-Nov-18 10:27 AM if it really has to be failsafe I usually use relay logic, powered by a lead acid battery 19-Nov-18 10:33 AM Afternoon 19-Nov-18 10:33 AM Is it a custom system you are designing? 19-Nov-18 10:33 AM Yeah, definitely planning to have this whole thing live on a UPS of some kind eventually. I'm starting with some linear steps for pumpdown and back to atmosphere, and the idea is that it'd be ideal if I could have it be able to pick up wherever it left off after a power failure or circuit reset, by reading sensor states and statically-stored values on-chip, possibly, too. 19-Nov-18 10:33 AM Yeah. 19-Nov-18 10:33 AM I've looked into relay/ladder logic and it seems to be the right thing for this, but I've not yet wrapped my head around reading/writing the diagrams for it 19-Nov-18 10:35 AM I'm guessing you're talking about your TMP problem on twitter? 19-Nov-18 10:37 AM This is pertinent to that, yeah. It would be nice to be able to leave my system unattended and trust to some capacity that things won't go horribly awry. Plus I'm super forgetful.. >.> stuff like 'turn on the cooling fan' should not be a manual procedure 19-Nov-18 10:38 AM Turbos are better for set and forget. I'd still be hesitant to keep my diff pump on all day while at work away from it 19-Nov-18 10:38 AM We have a turbopumping station that we flip on and leave for pumpdown for days or even a week if needed without issue 19-Nov-18 10:38 AM Actually not too much control or interlocking on it either, but better safe than sorry 19-Nov-18 10:38 AM What's the issue you are having with your setup currently? 19-Nov-18 10:40 AM yeah that's the ideal goal 19-Nov-18 10:43 AM I don't know much about your system, what else could go wrong once it has a UPS? 19-Nov-18 10:44 AM How necessary is a ups for a turbo system though? I can see it being critical for diff setups where if power blows out you still would want to maintain cooling and roughing to prevent degredation of the oil 19-Nov-18 10:44 AM Unless your experiments require extremely tight control 19-Nov-18 10:45 AM cheap rotary vane pumps love to flow oil back into the vacuum line when powered off under vacuum 19-Nov-18 10:45 AM ^^^ 19-Nov-18 10:45 AM I was extremely concerned about that happening at one point. Also I'd like to have datalogging during outages still 19-Nov-18 10:46 AM but that's a totally different issue, imo you should really work on your foreline 19-Nov-18 10:46 AM That's not an issue with foreline traps though 19-Nov-18 10:46 AM If I was clever, I can pull 48VDC out of my turbo system while it's spinning down in a no-AC situation 19-Nov-18 10:46 AM once all the oil is out air will come through 19-Nov-18 10:47 AM I mean, true, but I hate cleaning out my foreline trap >.> 19-Nov-18 10:47 AM that's work and I'm lazy 19-Nov-18 10:47 AM True, but better the trap than the turbo foreline 19-Nov-18 10:48 AM and i don't like juggling zeolites more than necessary bc i can't find conclusive evidence on whether the pore structure makes them.. asbestos-like, or otherwise Bad To Breathe In 19-Nov-18 10:48 AM Probably not great for you in any event 19-Nov-18 10:48 AM Zeolites are sold as solid pellets, shouldn't be an issue unless you are crushing and inhaling them 19-Nov-18 10:49 AM The issues I'm having with my setup are basically that I am ADHD as hell and would like a SEM style diagnostic readout and automatic pumpdown and vent-to-atmosphere control 19-Nov-18 10:50 AM Btw, how did MegunoLink work out for you? Or are you looking for a different control solution? 19-Nov-18 10:50 AM Also my zeolites are kinda dusty. They are solid pellets from I assume a long extruded rod snapped into little rabbit-food-lookin' sticks 19-Nov-18 10:50 AM I'm working on that type of diagnostic and control now, but it's a lot of work 19-Nov-18 10:51 AM I haven't been able to get it to work on Linux at all. >.> I also have not yet looked at yr source code. I feel like I'd like to know how to implement this kind of industrial control logic anyways, so. 19-Nov-18 10:51 AM That was one of the goals of my system is that I wanted to safely automate all these steps. It's not strictly necessary to do, but I am an automation engineer and enthusiast by profession and in my personal life. (with computers, anyways. Puppet 'n stuff.) 19-Nov-18 10:52 AM Whst I don't get is why the cooling fan is not turned on simultaneously with power on the turbo. 19-Nov-18 10:52 AM easyest and properbly safest method for you would be to get a foreline pump that dosen't ooze oil once it's turned off 19-Nov-18 10:53 AM Well, >.> in my case my cooling fan is powered by a separate ATX power supply I have to turn on it make it go. This is, I freely admit, dumb as hell. 19-Nov-18 10:53 AM stuff like that happens 19-Nov-18 10:54 AM Yeah. My foreline pump is the cheapest dual-stage rotary vane pump I could find. It was $150 new. 19-Nov-18 10:54 AM I'm really glad it works at all, honestly. 19-Nov-18 10:54 AM I got my leybold D2.5E for around the same price 19-Nov-18 10:54 AM that can be left under vacuum when powered off, never had any issues with it 19-Nov-18 10:55 AM I also bought it at a time when I wasn't sure what I needed and wasn't sure how hard I'd dig into this hobby. Turns out, it's.. kinda spiraled out of control >.> 19-Nov-18 10:55 AM So yeah, I'm on the lookout for something better, but it's low on the list as long as I can engineer around it. 19-Nov-18 10:55 AM (mostly because i am approximately out of money to spend on a whole 'nother roughing pump, for now.) 19-Nov-18 10:55 AM bbiab, headed into work 19-Nov-18 10:57 AM Dammit...put a multi circuit switch and use one circuit to cross the green line with a groubd line so the psu starts. Quite simple. 19-Nov-18 10:57 AM Babay! 19-Nov-18 10:58 AM +1 19-Nov-18 10:58 AM Have fun at work ^^ 19-Nov-18 10:59 AM I know, lol. I should have it hooked into the turbo psu directly. Gotta do 80VDC- >12VDC, shouldn't be too hard. 19-Nov-18 10:59 AM o/ 19-Nov-18 11:36 AM oh, so, also, i need at least 3 CFM to back my turbo, iirc. so i'm, like.. quietly holding out for a good deal on an edwards rv5 or rv8 or somesuch 19-Nov-18 11:36 AM also if i spend a lot of dosh on a new pump, i'd like something i can rebuild without too much work if need be. have it be an investment and all that 19-Nov-18 11:36 AM i tried ~rebuilding one of these $150 pumps and that.. did not work at all. >.> 19-Nov-18 11:36 AM but, hey, learning experiences! 19-Nov-18 11:37 AM been there, done that, not-pinned stator parts are the worst >.< 19-Nov-18 11:38 AM Haha, I definitely had one of the rotor springs launch itself across my garage at one point 19-Nov-18 11:38 AM good times :3 19-Nov-18 11:39 AM fun! 19-Nov-18 11:39 AM oh my, I recently got an electrometer and the specs are... hardcore 19-Nov-18 11:39 AM Isolation: 10^9 ohms (decreasing to 10^8 ohms at 30°C and 70% relH) 19-Nov-18 11:43 AM delicious gigaohms 19-Nov-18 11:44 AM and that's just isolation against ground, ohm measurement goes up to 10^12 ohm 19-Nov-18 11:44 AM i bought a huge three-stage CW assembly at the local junkstore and it had three 400 megaohm wax-coated bleeder resistors. i have no way to measure them, lol 19-Nov-18 11:44 AM could do something clever with the HVDC supply, maybe 19-Nov-18 11:45 AM just send them over, I've got a pAmeter and Tohmmeter here, plus the electrometer, once it is repaired ^^ 19-Nov-18 11:45 AM oo neat 19-Nov-18 11:45 AM i have a picoammeter that may need calibration 19-Nov-18 11:45 AM plan to use it on the business end of a faraday cup for ion current measurements 19-Nov-18 11:46 AM I should add that the pAmeter ist just a loan and the Tohmmeter ist only calibrated up to 1 Gohm 19-Nov-18 11:46 AM NOISE: 2x10^-15 ampere peak-to-peak on the most sensitive range, exclusive of alpha particle disturbance 19-Nov-18 11:47 AM wow 19-Nov-18 11:47 AM haha 19-Nov-18 11:47 AM If I've got an exessive amout of alpha-decaying dust in the air the electrometer will be the least of my problems 19-Nov-18 11:47 AM oh, btw, with all the fires around you, have you set up a filter outside and checked it for radiological contamination? 19-Nov-18 11:52 AM I make a point of running my GM counter over the dustiest areas of my room whenever I clean, but... haven't yet during the fires, here. I could just run it over the filter on my bedroom fan, which has since turned a lovely grayish brown >.> 19-Nov-18 11:52 AM (my bedroom/lab is technically outdoors) 19-Nov-18 11:52 AM S'worth a look! 19-Nov-18 11:52 AM I heard down in LA (LA is about a 6 hour drive from where I am) an old waste processing plant went up in flames, so radiological contamination might be more of an issue down there. 19-Nov-18 11:53 AM My vane pump doesn't have springs in the vanes. 19-Nov-18 11:53 AM holy hell, good luck with that plant! 19-Nov-18 11:54 AM It does 33microns at 1450rpm 19-Nov-18 11:56 AM from what I know only the cheaper ones have springs, others do it just by centrifugal force, which wears the stator much less 19-Nov-18 11:56 AM Ah! 19-Nov-18 11:56 AM Its a quite old, but good double stsge pump 19-Nov-18 11:58 AM what manufacturer? 19-Nov-18 11:59 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20181119_205926-DBECE.jpg 19-Nov-18 11:59 AM never heard of them 19-Nov-18 12:12 PM @qualia post the dgs storyyyyy 19-Nov-18 12:12 PM aAaA ok sec 19-Nov-18 12:12 PM (ty for reminder lol) 19-Nov-18 12:12 PM Why the name? One fateful evening in October of 2018, on Twitter, Qualia (@profanegeometry) eavesdropped on a conversation between @GigaSquirrel and Tom McCarthy (@FusorFusion) that would change the course of history forever. Tom was looking for a high vacuum gauge for <10^-3 mbar measurements, to which GigaBecquerel provided a link to the notorious Fusor Forums documenting the repair and reverse-engineering of a low-cost analog-readout ion gauge available en masse on eBay (namely, the Instrutech IGM-400). Days later, Qualia received their very own gauge in the mail and posted a picture of it, to which a deluge of like-minded vacuum folx summarily took notice and bought their own. Dave A (@dave_32768) proposed starting a club; @Nixie_guy suggested the name "Dead Gauges Society" (à la 'Dead Poets Society'), and the rest... is history. ✨ 19-Nov-18 12:12 PM :D 19-Nov-18 12:12 PM oh it's all funky and link-y now that people are actually here lol 19-Nov-18 12:17 PM beautiful! 19-Nov-18 12:17 PM and from that day on things just started.... escalating 19-Nov-18 12:18 PM as they do 19-Nov-18 12:21 PM what have we learned? If you want to keep your sanity, never get: A geiger counter High vacuum equipment A Multimeter above 4.5 Digits 19-Nov-18 12:24 PM that last thing is still on the shopping list 19-Nov-18 12:25 PM hp 3478a? 19-Nov-18 12:25 PM I talked to keysight last week, the 3458a successor will should come out some time next year 19-Nov-18 12:25 PM So now I'm hoping that shortly after that the used marked will be filled with cheap 3458a... 19-Nov-18 12:28 PM oh good gosh they're expensive 19-Nov-18 12:28 PM here's hoping, but they're a mid four-figure item on fleabay rn 19-Nov-18 12:28 PM quite cheap, considering they're literally the best one can get for money 19-Nov-18 12:28 PM oh wait the 3478 is cheaper 19-Nov-18 12:29 PM 3478 should go for ~$100 19-Nov-18 12:29 PM 3458 like 30 times that, if you're getting it cheap 19-Nov-18 12:29 PM 8.5 digits whoa 19-Nov-18 12:30 PM yep 19-Nov-18 12:30 PM for when you want all the resolution 19-Nov-18 12:33 PM OMG, should get one of those even if I am not sure I will use it. 19-Nov-18 12:33 PM rumors are that the new version takes so long because they have to make new standards for it 19-Nov-18 12:33 PM Excellent writing, @qualia 19-Nov-18 12:34 PM ^.^ i hope i did our storied history due justice. 19-Nov-18 12:35 PM @GigaSquirrel , the vacuum pump was so old, it uses cork isolation gaskets (not on the low pressure area). Took me a while to find a piece to replace. 19-Nov-18 12:35 PM The story should be read with this music: https://www.youtube.com/watch?v=3MJslaIGvGQ&t=0s 19-Nov-18 12:35 PM wow, I've never seen that irl 19-Nov-18 12:35 PM I think I have photos 19-Nov-18 12:36 PM dont mind the dust 19-Nov-18 12:36 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-35B6E.png 19-Nov-18 12:36 PM whats wrong with good old Thus Spoke Zarathustra? 19-Nov-18 12:36 PM and since it is the dead gauges society: https://www.youtube.com/watch?v=hpJ6anurfuw 19-Nov-18 12:36 PM god damn it, @george 19-Nov-18 12:37 PM sorry 19-Nov-18 12:38 PM Bahahaha, too weird for my liking (NOT saying it's bad, I don't have a taste for music) 19-Nov-18 12:39 PM I wouldn't count that as music, rather as comedy 19-Nov-18 12:39 PM Dismantled and cleaned. 19-Nov-18 12:39 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180314_172255-0747F.jpg 19-Nov-18 12:39 PM Cork gasket. 19-Nov-18 12:39 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180314_090318-44EEE.jpg 19-Nov-18 12:40 PM howly that thing looks huge! 19-Nov-18 12:41 PM It is not super massive, it has a big outer casing to hold the oil. 19-Nov-18 12:42 PM the bores of the vane castings look like about 3 inches inside diameter 19-Nov-18 12:42 PM haha, yuck. that looks like it must've wanted to crumble to oily dust years ago 19-Nov-18 12:42 PM i had D16 pumps apart and they are tiiiny compared to this one 19-Nov-18 12:42 PM what'd you replace it with? some rubber sheeting cut to size? 19-Nov-18 12:43 PM Managed to find a leftover of same cork material in a truck repair shop. ^^ 19-Nov-18 12:43 PM oh nice :o 19-Nov-18 12:43 PM Cleaning bath. Did not measure the rotors, sorry! 19-Nov-18 12:43 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG-20180313-WA0055-BE528.jpeg 19-Nov-18 12:43 PM The vanes look like wood. Maybe they are some composite? 19-Nov-18 12:43 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG-20180313-WA0059-991EC.jpeg 19-Nov-18 12:44 PM they are most likely glass fiber 19-Nov-18 12:44 PM or phenolic resin with cotton 19-Nov-18 12:44 PM in both cases colured by the oil 19-Nov-18 12:44 PM there is not many places as disgusting than an old vane pumps oil sump... 19-Nov-18 12:46 PM I'd vote for the phenolic resin. Viewed from the side, they looked like multi layered wood. (forgot the name of it) 19-Nov-18 12:46 PM Mine was quite clean, I would say. 19-Nov-18 12:47 PM jep, most likely this stuff 19-Nov-18 12:48 PM Just after emptying the oil. It was not gross to touch. 19-Nov-18 12:48 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180313_172812-7177B.jpg 19-Nov-18 12:49 PM not bad, I've seen worse 19-Nov-18 12:50 PM 150€, used to make neon signs (the seller said). I am happy with the purchase. 19-Nov-18 12:51 PM It's always good to know where it came from, I'd never get one that was used by a chemist or biologist 19-Nov-18 12:51 PM XDDDDDD 19-Nov-18 12:53 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180917_145307-11512.jpg 19-Nov-18 12:54 PM That looks certainly mucky... 19-Nov-18 12:54 PM Is the white residue in the flask, also part of what came out? 19-Nov-18 12:55 PM after that picture we dropped a nut in the beaker, it broke and there was fun all around 19-Nov-18 12:55 PM yep 19-Nov-18 12:56 PM XDDDDDD 19-Nov-18 12:56 PM Oh, i guess when it has never seen anyvapor you are very lucky! 19-Nov-18 12:56 PM I think I have a photo of my oil. 19-Nov-18 12:57 PM I have had pumps used in physics labs and i have no idea what they used to pump but the stuff didnt drain with the oil... 19-Nov-18 12:57 PM Saved the oil to make french fries, btw. 19-Nov-18 12:57 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG-20180313-WA0011-4AF2A.jpeg 19-Nov-18 12:57 PM i had to take apart every single one and clean them out mechanically with gloves and fingers 19-Nov-18 12:57 PM taaaaasty 19-Nov-18 12:58 PM Probably pure metals that amalgamated once they came together. 19-Nov-18 12:58 PM it still was sludge 19-Nov-18 12:58 PM but definetly not the kind id like to eat 19-Nov-18 12:58 PM XD! 19-Nov-18 12:58 PM or touch for that matter 19-Nov-18 12:58 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/4a8412224fcbdc147a49fdd7e353899c-E5EC5.png 19-Nov-18 12:59 PM xD 19-Nov-18 12:59 PM this. 19-Nov-18 12:59 PM I have worked with 72% HF, I am not afraid anymore of the science. 19-Nov-18 12:59 PM (I should make a badge for that, it's the insanest thing I have ever done). 19-Nov-18 01:00 PM that stuff scares me 19-Nov-18 01:00 PM ("worked", bought a bottle, diluted it at home, in my homemade fume hood, makes it worse) 19-Nov-18 01:01 PM i dissolver mercury in hno3 19-Nov-18 01:01 PM im still scared the f of that beaker 19-Nov-18 01:01 PM i was 15 back then and havent touched it since 19-Nov-18 01:01 PM It makes an explosive, right? 19-Nov-18 01:01 PM mercury fulminate? 19-Nov-18 01:02 PM wel, youd have to continue doing stuff to it 19-Nov-18 01:02 PM (I know shit about chemistry, sorry if I say something stupid) 19-Nov-18 01:02 PM for fulminate you'd have to add etoh iirc 19-Nov-18 01:02 PM i tried back then 19-Nov-18 01:02 PM https://youtu.be/IUrEdExiwko 19-Nov-18 01:02 PM it didnt work out, so now i have a beaker of water soluable mercury salts 19-Nov-18 01:02 PM id much rather handle hf than get mercury in my blood 19-Nov-18 01:03 PM just add a sulfide solution 19-Nov-18 01:03 PM but the wors corpse in my basement is a 1/2 liter teflon container with unknown brown sludge obtained from uranium ore 19-Nov-18 01:03 PM Well, HF will kill you fast, mercury will turn you insane. 19-Nov-18 01:03 PM HOLY F 19-Nov-18 01:04 PM dose rate from that container? ^^ 19-Nov-18 01:04 PM have you tested it with a 19-Nov-18 01:04 PM what @GigaSquirrel said. 19-Nov-18 01:04 PM wel, my counters are not calibrated but i know that it is quite active ^^ 19-Nov-18 01:04 PM problem is that i followed someone elses "manual" for making yellowcake 19-Nov-18 01:05 PM /slowly walks away from georg/ 19-Nov-18 01:05 PM but the mineral i started with was a different one, so thechemistry didnt work out as planned 19-Nov-18 01:05 PM so now im left with sludge of unknown composition 19-Nov-18 01:05 PM acidic with free oxygen 19-Nov-18 01:06 PM I'm gonna bring some detectors from work when I visit you ^^ 19-Nov-18 01:06 PM I'll bring some lead. on myself probably. 19-Nov-18 01:06 PM XDDD 19-Nov-18 01:07 PM uell, tehre is no mre stuff in there than in 500g of ordinary rock found outside in nature ^^ 19-Nov-18 01:07 PM This group should have been called "About to die in some unusual ways society" 19-Nov-18 01:09 PM hopefully I'm not about to die, I haven't completed the list of things I want to do yet 19-Nov-18 01:09 PM Btw, @GigaSquirrel , have you priced a single of those capacitors? 19-Nov-18 01:09 PM for selling, I mean. 19-Nov-18 01:10 PM dunno, we got them for free, getting them into storage was a lot of work, we were thinking something like 100€ a piece as compensation 19-Nov-18 01:11 PM I might try to buy at least one from you in the long future. 19-Nov-18 01:11 PM I have a friend who does HV stuff who would be delighted to get that as a birthday gift. 19-Nov-18 01:12 PM tbh we're unsure about selling / shipping them outside of germany, since we were informed it is a legal gray area to own them 19-Nov-18 01:13 PM really?... 19-Nov-18 01:13 PM oh well. 19-Nov-18 01:13 PM well, owning a capacitor is legal ofc but something in that energy range implies a lot of things 19-Nov-18 01:13 PM True. 19-Nov-18 01:13 PM Well, I tried. 19-Nov-18 01:14 PM we're still on it getting that sorted 19-Nov-18 01:14 PM Will ask in the future, then. (starts his DeLorean) 19-Nov-18 01:15 PM starts like 5 deloreans at a time per capacitor... 19-Nov-18 01:15 PM XDDDDDDDDDDDDDDDDD 19-Nov-18 01:15 PM Btw, you will say it is all sorted out. (just came back from 2y in the future). 19-Nov-18 01:16 PM well in that case buys shipping lable for spain 19-Nov-18 01:16 PM Excellent. 19-Nov-18 01:18 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Z-F3F67.png 19-Nov-18 01:18 PM In the end I did not do the livestream of the oven today. I'll try tomorrow at 5 in the evening or something like that. 19-Nov-18 01:18 PM Also, will do a special, close up, edition of the HVAC manipulator for @qualia 19-Nov-18 01:18 PM (the time is that it seems the moment with most people awake/not doing much) 19-Nov-18 01:20 PM 5 pm what timezone? ^^ 19-Nov-18 01:20 PM Madrid/Paaris 19-Nov-18 01:21 PM finally someone in my timezone 19-Nov-18 01:21 PM XDD 19-Nov-18 01:21 PM and Georg? 19-Nov-18 01:22 PM same 19-Nov-18 01:22 PM 200km N/W 19-Nov-18 01:22 PM Cool. 19-Nov-18 01:23 PM I should be home at that time 19-Nov-18 01:23 PM (Georg, it will be me just recoiling my semiconductor oven, nothing super interesting, but I'm using it to get used to talk to a camera, and maybe do some youtube when the semicon processes have results) 19-Nov-18 01:23 PM @GigaSquirrel I'll ping you, and adjust my time of emission. 19-Nov-18 01:24 PM uh that would be nice 19-Nov-18 01:25 PM thanks! 19-Nov-18 01:25 PM I did oneor two narrated videos on my old youtube channel in 2013 or so 19-Nov-18 01:25 PM I have until 7:45, and recoiling doesn't take that much time. Might give a shop tour or something if people ask. 19-Nov-18 01:25 PM i know how freaking hard it is to listen to yourself afterwards 19-Nov-18 01:26 PM Yeah 19-Nov-18 01:26 PM It took me 71 takes to make my video for the Hackaday Prize 19-Nov-18 01:26 PM like 3 hours talking to a gopro mounted on my shoulder. 19-Nov-18 01:27 PM oh gawd 19-Nov-18 01:27 PM I hate photos being taken, could not imagine standing infront of a camera for that amount of time 19-Nov-18 01:28 PM Naaaa, did it with the camera mounted on my shoulder, showing only my hands. 19-Nov-18 01:28 PM XDDD 19-Nov-18 01:28 PM (I sent the link to georg via DM to not clutter the general) 19-Nov-18 01:29 PM ohh, I was thinking of something like a selfiestick mounted on your shoulder 19-Nov-18 01:30 PM na, I got a cheap RC gimbal and a shoulder strap. 19-Nov-18 01:30 PM I want as much space as you have in your workshop... 19-Nov-18 01:30 PM mine is like 1.5x3m 19-Nov-18 01:31 PM looks much bigger than what it is. I think it's 13,5 sq meters. Looks clean, but I am at max capacity. I can't fit anything else. The turbo and sensors sit behind me in the video, and they permanently clutter the electronics table. :/ 19-Nov-18 01:32 PM in that space I've got a tiny lathe, a drillpress and a whole lot of metal chips flying around everywhere 19-Nov-18 01:32 PM still gotta clean the lathe, according to tracking the first parts for the cryo will arrive next wednesday 19-Nov-18 01:35 PM Oh sh...yes, you need more space definitely. 19-Nov-18 01:36 PM At least you all have a workshop lol. Dining room table and tiny spare bedroom for my stuff 19-Nov-18 01:38 PM spare bedroom? sounds like a workshop to me 19-Nov-18 01:38 PM i sleep in the same room as my turbo is running all night 19-Nov-18 01:38 PM Except half the bedroom is for my clothes/laundry. Can't even walk in there now 19-Nov-18 01:38 PM Also, for those caps, you will mainly want to look at export control laws of your country 19-Nov-18 01:39 PM In europe we should at least not have to worry about export. 19-Nov-18 01:39 PM Ik for the US, pulsed power tech, especially ns stuff is export fontrolled, mainly since it's used fir weapons research 19-Nov-18 01:40 PM yep, that's what I've heard 19-Nov-18 01:41 PM I'm not sure what will happen when I start publishing my EXEDA build in that regard, but I will pursue it relentlessly until I get a cease and desist lol 19-Nov-18 01:41 PM You may want to save some caps when you can see what can be done with them... 19-Nov-18 01:42 PM we're going to keep at least 2 19-Nov-18 01:42 PM More than eough 19-Nov-18 01:43 PM I'd love to do some z-pinch fusion, but where... 19-Nov-18 01:43 PM Pinch stuff is pretty easy to do 19-Nov-18 01:43 PM you couldn't discharge one of those things anywhere near without someone calling the cops 19-Nov-18 01:44 PM Lots of sound insulation lol 19-Nov-18 01:44 PM If you are firing via spark gap switch, that should be easy to shield audibly 19-Nov-18 01:44 PM Of course the emp is another story, but one step at a time 19-Nov-18 01:45 PM I was not able to find any other switch for 150kA @ 40 kV but a spark gap 19-Nov-18 01:45 PM I could try to get a krytron, but in that case I'll definately end up in a high security prison, don't what to know how many lists I'm on already... 19-Nov-18 01:46 PM Spark gap is easy and cheap. You can get into some really insane high tech spark gap stuff too, the state of the art gaps are works of art 19-Nov-18 01:47 PM yeah, was thinking about 2 simple rods of WCu and a tungsten trigger 19-Nov-18 01:47 PM I've already talked @qualia ear off ad nauseum about spark gaps and how amazing they are lol 19-Nov-18 01:47 PM That will do it 19-Nov-18 01:47 PM For my system, I need a more optimized and engineered solution for the fast gap 19-Nov-18 01:47 PM Even simple triggered gaps have optimum ratios and geometries 19-Nov-18 01:49 PM iirc the caps were used in a system with a tsg under SF6 achiving ~100 kV/ns 19-Nov-18 01:49 PM sadly I didn't get a look at that gap 19-Nov-18 01:50 PM That's decent, but you can go much faster 19-Nov-18 01:50 PM really? 19-Nov-18 01:50 PM holy shit 19-Nov-18 01:51 PM Some of the fastest Russian tech hits around 200kv at a few hundred picoseconds FWHM 19-Nov-18 01:51 PM I have to retire, gentlemen. Will read all your nice writings tomorrow! 19-Nov-18 01:51 PM That's not rise time lol, that's pulse width 19-Nov-18 01:51 PM I envy you all! Gnait! 19-Nov-18 01:51 PM good night 19-Nov-18 01:51 PM Ttyl! Night! 19-Nov-18 01:51 PM gn8! 19-Nov-18 01:53 PM what's the most important factor in a fast sg? Distance? 19-Nov-18 01:53 PM A bunch of stuff. Inductance is primary, which is primarily a product of distance 19-Nov-18 01:53 PM However, to get subnanosecond, you need some additional stuff 19-Nov-18 01:54 PM but wont the connections still ave the largest inductance anyways? 19-Nov-18 01:55 PM That's the thing. The whole system has to be optimized. The spark gap is built into an impedance matched transmission line connected to the load 19-Nov-18 01:55 PM This isn't something you use wires or even bus bars for anymore 19-Nov-18 01:55 PM I actually brought this up with @AdamMcCombs before. There us a special type of electron gun that operates at atmosphere through runaway electron emission. Requires a driver that hits several hundred kv sub 100 ps 19-Nov-18 01:57 PM ok, i suspected you could just keep all connections insanely short 19-Nov-18 01:57 PM It's not so much short anymore, but about impedance matching and transmission lines 19-Nov-18 01:58 PM oh, btw, maybe someone here can help me, I'm looking for a name 19-Nov-18 01:58 PM Ridiculous optimized geometries and transitions 19-Nov-18 01:58 PM wich is also interestng when plasma is involved of wich you dont know the impedance 19-Nov-18 01:58 PM i guess tahts where the hard part is 19-Nov-18 01:59 PM I recently saw a measurement system originally designed for nuclear weapons research, based on analog transmission over fiber, the name was something like nucleofast? 19-Nov-18 01:59 PM Never heard of it 19-Nov-18 02:00 PM it was a 1 u 19" ...thing 19-Nov-18 02:00 PM capable of measuring kA currents in the ps range 19-Nov-18 02:00 PM but I can't find a mention of it anywhere 19-Nov-18 02:01 PM Does it connect to a scope? 19-Nov-18 02:01 PM Or is it standalone? 19-Nov-18 02:01 PM That's the problem with ultrafast stuff, the scopes needed are stupid expensive 19-Nov-18 02:01 PM I'd do more of it if I had a fast scope lol 19-Nov-18 02:01 PM I can play with it at work, but not really post stuff 19-Nov-18 02:01 PM Unless it's my own 19-Nov-18 02:02 PM the system consists of a battery powered box that turns the electrical signal into an optical one, the rackmount unit just had an output for a scope 19-Nov-18 02:02 PM I know, I'm currently looking for a new scope as well 19-Nov-18 02:03 PM Yeah, so you still need a scope with some ridiculous bandwidth 19-Nov-18 02:03 PM yep 19-Nov-18 02:03 PM it's not that I really want one of those systems, I'm just interested in all things nuclear ^^ 19-Nov-18 02:04 PM The best stuff is the fast stuff though! 19-Nov-18 02:05 PM and also the most expelsive.... 19-Nov-18 02:05 PM For me, it's all about intense beams 19-Nov-18 02:05 PM saw the 100 GHz keysight scope last week 19-Nov-18 02:05 PM and oh my, I want one 19-Nov-18 02:05 PM Oh man that's awesome 19-Nov-18 02:05 PM Isn't it like 500k? 19-Nov-18 02:05 PM twice that 19-Nov-18 02:06 PM Oh, been a while since I checked lol 19-Nov-18 02:06 PM "I want one" and "I can afford one" is a very different thing most of the time 19-Nov-18 02:06 PM Yeah... 19-Nov-18 02:06 PM They didnt want to borrow it to us though 19-Nov-18 02:06 PM You can improvise the physics side cheap, but there is no way around a good fast scope 19-Nov-18 02:07 PM yep 19-Nov-18 02:07 PM up to 100 MHz is <500€, but a decent 350 MHz one is like 5k :< 19-Nov-18 02:07 PM 4 channel that is 19-Nov-18 02:08 PM wouldnt analog do it in this case? 19-Nov-18 02:08 PM I'd be happy with just 1 channel for now, I technically don't even have a scope 19-Nov-18 02:08 PM if you are only interested in one event 19-Nov-18 02:08 PM There are good scopes that pop up on ebay for less 19-Nov-18 02:08 PM especially for single events you need good storage 19-Nov-18 02:08 PM https://www.youtube.com/watch?v=uuLP8-XnBxE 19-Nov-18 02:08 PM if this one had a storage tube it would do ii guess 19-Nov-18 02:10 PM dunno, digital really has its perks 19-Nov-18 02:10 PM Anyone here know how to build high speed scopes on the cheap? 19-Nov-18 02:10 PM Figure that out, and you're golden 19-Nov-18 02:10 PM can you debug a diy scope without a faster scope? 19-Nov-18 02:11 PM i would see it more liek a capture device in this case 19-Nov-18 02:11 PM when you have only one event to look at tehre is no averaging, calculating and filtering 19-Nov-18 02:11 PM just one shot and then analyze later 19-Nov-18 02:12 PM there is some calculating that needs to be done, like integrating the area 19-Nov-18 02:12 PM I'm not gonna conut squares for that 19-Nov-18 02:13 PM when its only the one shot to check a cap discharge id happily do that ^^ 19-Nov-18 02:13 PM I'm not getting the scope for my caps ^^ 19-Nov-18 02:14 PM i know, im talking about the pinch stuff, not detector building ^^ 19-Nov-18 02:15 PM pinch and stuff like that is in the far future, I'll not charge one of those caps unless I'm 100% sure I know what I'm doing 19-Nov-18 02:15 PM I'm in dire need of a faster scope 19-Nov-18 02:15 PM mine maxes out at like 5 MHz when doing any sampling 19-Nov-18 02:15 PM 50 MHz in pure analog mode 19-Nov-18 02:16 PM and that's just not the case with high voltage at that energy 19-Nov-18 02:16 PM this is not great for trying to capture fast transients 19-Nov-18 02:17 PM Yeah, at those stored energies you really need to have a well engineered safety and interlock system 19-Nov-18 02:17 PM @qualia I'll let you know if I find one ^^ 19-Nov-18 02:18 PM shipping might end up being more than the scope itself >.> 19-Nov-18 02:19 PM was thinking more of something like a model number ^^ 19-Nov-18 02:19 PM like 1054z, for starters 19-Nov-18 02:20 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-DAE48.png 19-Nov-18 02:20 PM Thats my "workhorse" 19-Nov-18 02:20 PM a whopping 60MHz 2ch... 19-Nov-18 02:22 PM ouch 19-Nov-18 02:23 PM surprisingly it actually does most stuff needed in electronics, just not physics 19-Nov-18 02:25 PM with electronics I'm mostly below 20 MHz, but physics is the issue 19-Nov-18 02:29 PM @GigaSquirrel oh, gotcha! :o 19-Nov-18 02:29 PM model numbers are nice because i can use them to turn ebay saved searches into credit card debt very efficiently 19-Nov-18 02:30 PM maybe I should sell more stuff for some money 19-Nov-18 02:30 PM anyone interested in looks around A couple of HeNe lasers some PMTs some GM tubes stuff like that 19-Nov-18 02:40 PM [shipping to the US not included] 19-Nov-18 02:40 PM this is why we-... you americans can't have nice things 19-Nov-18 02:40 PM uh, found a big box of electron tubes from radios and stuff, maybe some collectors are interested in that 19-Nov-18 02:43 PM XD! (I'm not here, I'm just a ghost of before bed reading past) 19-Nov-18 02:43 PM I will ask for help to find a diode/transistor analizer (not sure if that's the name). 19-Nov-18 02:44 PM are you looking for a curve tracer? 19-Nov-18 02:44 PM At some point next year I'll be doing transistors small enough to require actual measurements and such. 19-Nov-18 02:44 PM Yeah, exactly that. 19-Nov-18 02:45 PM the octopus circuit might be fine for first tests 19-Nov-18 02:46 PM Sorry, I don't speak chinese. 19-Nov-18 02:46 PM http://www.qsl.net/kd7rem/img/test/octopus.gif 19-Nov-18 02:46 PM (spanish idiom, for "whaaat?") 19-Nov-18 02:46 PM same idiom here in germany ^^ 19-Nov-18 02:47 PM Bhahah 19-Nov-18 02:47 PM https://www.instructables.com/id/Transistor-Curve-Tracer/ 19-Nov-18 02:47 PM Tjsts quite interesting! 19-Nov-18 02:47 PM how about this one? 19-Nov-18 02:47 PM Very nice too. 19-Nov-18 02:48 PM that looks very nice 19-Nov-18 02:48 PM I'm surprised I cant find that kit on ebay 19-Nov-18 02:49 PM not a market bi enough for chinai guess 19-Nov-18 02:49 PM i dont think they are needed as much as other chincy stuff 19-Nov-18 02:49 PM was hoping for something like the m tester 19-Nov-18 02:49 PM Hum...I should be able to actually use my cnc to analog comverters to do that. 19-Nov-18 02:49 PM (I made a circuit to use cnc signals and transform them into analog voltages with a R2R ladder. 19-Nov-18 02:49 PM (weird idea to transform a crt into a crude electron beam etcher) 19-Nov-18 02:51 PM hehe, nice 19-Nov-18 02:51 PM not a bad idea, actually 19-Nov-18 02:51 PM I will have spare pcbs soon if anyone wants. 19-Nov-18 02:51 PM (soon: a month) 19-Nov-18 02:52 PM what resolution? 19-Nov-18 02:53 PM Please be gentle, I am not a pro pcb designer. 19-Nov-18 02:53 PM I thought about making a crt into an electron beam weder but etcher could be even more useful 19-Nov-18 02:53 PM /highfives georg/ 19-Nov-18 02:53 PM (uploading photos) 19-Nov-18 02:53 PM I think I made it 12 bits. But since it is a handmade ladder, even if using 1% for the first 8bits and 0,1% for the 4 lsb's, I'm not sure if it has full precision. 19-Nov-18 02:59 PM hm, sounds interesting 19-Nov-18 02:59 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181119_235913-5F4E2.jpg 19-Nov-18 02:59 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181119_235906-34F53.jpg 19-Nov-18 03:00 PM oh, I see a shitton of shift registers and resistors 19-Nov-18 03:02 PM well, except for maybe that close to the edge soic8 i dont see anything i dont like here 19-Nov-18 03:02 PM and for the resistor tolerances, couldnt you just calibrate those in software? Should not be to much trouble i think 19-Nov-18 03:15 PM Yeah,better keep ot simple. I don't have the equipment to do such calibration. Ideally, I would love to use them as is. 19-Nov-18 03:15 PM Gnait everyone! 19-Nov-18 03:15 PM good night 19-Nov-18 03:37 PM gonna go now, too, good night 19-Nov-18 03:48 PM Joined the server. 19-Nov-18 03:49 PM o/ 19-Nov-18 03:49 PM hai 19-Nov-18 04:27 PM hihi c: I invited @rqou , we're about to start collaborating on some vacuum-adjacent project work together, hopefully 19-Nov-18 04:27 PM assuming the stars all align just so 19-Nov-18 04:31 PM Joined the server. 19-Nov-18 04:31 PM Hello! 19-Nov-18 04:32 PM Hello to you as well 19-Nov-18 04:34 PM Is this the meeting of the dead guage society? 19-Nov-18 04:37 PM Hello @rqou and @Dave 32768 19-Nov-18 04:41 PM So @Applied_Ion, I found a video on how to clean a ion polisher gun 19-Nov-18 04:41 PM https://youtu.be/wM5ocC74Ef0 19-Nov-18 04:47 PM Awesome! I'll watch it now, looks like it will give plenty of visual info to reverse engineer, though I'm assuming you don't need something as precision? 19-Nov-18 04:47 PM Also, do you prefer conflat or kf for your setup? 19-Nov-18 04:57 PM Anything will work, kf is probably cheaper, but I don't have a chamber for this yet 19-Nov-18 04:58 PM We can probably figure out something that could be adapted to either 19-Nov-18 05:06 PM Yeah. I also have to figure out what I am going to use for my stage and what no 19-Nov-18 05:07 PM Is the 5kv spec you stated earlier based on typical values for commercial systems? 19-Nov-18 05:09 PM Yeah. There are some higher kv systems that gatan makes, but the JEOL and Hitachi units run around 5 or 6 max 19-Nov-18 05:23 PM On the gatan website they quote an ion beam diameter of 1mm for argon ion polishing 19-Nov-18 05:23 PM We could also easily run SRIM/TRIM models to determine implantation depth, sputtering, and damage if needed, which they site using to confirm sputtering based on impingement angle as well 19-Nov-18 05:23 PM http://www.gatan.com/argon-ion-polishing-focused-ion-beam-specimens-pips-ii-system 19-Nov-18 05:23 PM The user manuals also give a bunch of very useful info for design specs as well 19-Nov-18 05:23 PM Jackpot. Looks like it's a Penning Ion Gun. 19-Nov-18 05:37 PM The pips system is usually used for TEM sample prep, but im sure there is a lot to learn from it 19-Nov-18 05:38 PM Still can be used for general sample polishing, and chances are most commercial systems are going to use similar technologies 19-Nov-18 05:38 PM Yeah that a good point 19-Nov-18 05:39 PM Knowing they use a Penning gun is a huge plus, narrows down the selection 19-Nov-18 05:39 PM They are fairly simple as well 19-Nov-18 05:41 PM Yeah that kinda what I was seeing 19-Nov-18 05:41 PM it gives me a place to start my research too 19-Nov-18 05:42 PM Page 60 and 61 show very basic assembly drawing of the gun 19-Nov-18 05:42 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Model691-19306.pdf 19-Nov-18 05:43 PM icp, W, photon, and field emission are the ones i mostly work with so I'm not very familiar with the others that are available 19-Nov-18 05:45 PM I thought penning could be an option to explore based on current levels and input parameters, but I wanted to confirm it first 19-Nov-18 05:45 PM Well I say we have 19-Nov-18 05:46 PM Granted it's not the only option, but it's a good start 19-Nov-18 05:46 PM It looks like it wont be to hard to build as well 19-Nov-18 05:48 PM Also, penning guns are generally cold cathode based, so no filament needed 19-Nov-18 05:48 PM All the better 19-Nov-18 05:50 PM I'll check my files. Generally my ion beam stuff is very high current, but I may have basic papers on this type of gun 19-Nov-18 05:51 PM I need to finish compressing those 19-Nov-18 05:58 PM Those are just my vacuum resources lol 19-Nov-18 05:58 PM I've got several gigabytes of papers in my main physics research folder 19-Nov-18 05:58 PM About 1500 digital papers, not including the several thousand of papers I obtained in print on pulsed power alone from very large IEEE international conference proceedings. 19-Nov-18 06:05 PM wow 19-Nov-18 06:05 PM thats a lot 19-Nov-18 06:08 PM Yeah lol, it's a good reference library of resources. Years of just downloading and reading about whatever cool physics stuff piques my interest, mainly high voltage, plasma, pulsed power, accelerator, etc. 19-Nov-18 06:25 PM I've been meaning to set up some i3 shortcuts that let me hit a keystroke, paste in a DOI, and then get my pdf viewer popped open to a saved local copy of whatever that thing was 19-Nov-18 06:25 PM c/o scihub 19-Nov-18 06:33 PM Joined the server. 19-Nov-18 06:33 PM hi kia~ 19-Nov-18 06:33 PM h-hi 19-Nov-18 06:34 PM Joined the server. 19-Nov-18 06:34 PM vacuum 19-Nov-18 06:35 PM Yeah i know it really sucks 19-Nov-18 06:35 PM ah, relevant content! my favorite 19-Nov-18 06:37 PM hello ive never built a vacuum machine but i do work with the very big vacuum so close enough 19-Nov-18 06:38 PM Well you are going to have to do some testing at some point I imagine 19-Nov-18 06:38 PM Joined the server. 19-Nov-18 06:38 PM Joined the server. 19-Nov-18 06:39 PM Hi phil 19-Nov-18 06:39 PM hi hi 19-Nov-18 06:39 PM big fan 19-Nov-18 06:39 PM oh hi :o 19-Nov-18 06:39 PM i do actually need to hire someone to build a weak vacuum for welding purposes but not really any time soon 19-Nov-18 06:39 PM e- beam stuff? 19-Nov-18 06:39 PM no nothing special just linear friction 19-Nov-18 06:40 PM Hi to all the new members joining! 19-Nov-18 06:40 PM like extremely rough vacuum from the way you described it 19-Nov-18 06:40 PM but it has to withstand some pretty rough stresses in flight so i care a lot about join quality 19-Nov-18 06:40 PM yeah 200 tor lol 19-Nov-18 06:40 PM actually while i'm thinking about it if you've got like a paper or a resource for that particular technique i'd be really curious to read it 19-Nov-18 06:40 PM it is only a vacuum system because it has to be like a 1000 sqft area 19-Nov-18 06:40 PM in a factory 19-Nov-18 06:41 PM Yeah thats not small 19-Nov-18 06:41 PM simple pump with moderately complex control requirements 19-Nov-18 06:41 PM i tried googling around and i couldn't find anything on it 19-Nov-18 06:42 PM at least its not one of the massive dp pumped systems 19-Nov-18 06:42 PM there was a bout of research about welds for in-orbit construction i pulled the idea from 19-Nov-18 06:42 PM i can dig it up again after i finish some business work 19-Nov-18 06:42 PM 'k! 19-Nov-18 06:42 PM @qualia what info are you looking for? 19-Nov-18 06:43 PM is applied ion that guy who's working on a propulsion project with a budget of like $30 19-Nov-18 06:44 PM snrk 19-Nov-18 06:44 PM @Applied_Ion sig and i talked about friction welding in vacuum at one point; apparently doing it in just a very, very rough vacuum helps a lot with joint strengthening? idr exactly. 19-Nov-18 06:44 PM but it was intriguing 19-Nov-18 06:46 PM the settled grain in the join is much better if you do it with just less ambient gas 19-Nov-18 06:46 PM not really important in most cases but i have a combination of acoustic and thermal stresses most people dont have to fuck with 19-Nov-18 06:46 PM @sigfig yes I'm doing propulsion on a "low" budget. Unfortunately not $30 lol, but still several orders of magnitude cheaper than industry now. The engines will be dirt cheap to build, but the vacuum system still a couple of thousand 19-Nov-18 06:46 PM All open source design hopefully 19-Nov-18 06:47 PM ive seen your blog before it seems cool 19-Nov-18 06:47 PM Thanks! 19-Nov-18 06:47 PM Also working on open source high power/high energy accelerators, but I haven't released info on that officially yet 19-Nov-18 06:47 PM @qualia not much on vacuum friction welding 19-Nov-18 06:48 PM nod, it seemed like a very particularly niche thing 19-Nov-18 06:49 PM however, I got info on very high current, high pressure ebeams for vacuum welding 19-Nov-18 06:50 PM oh hey actually 19-Nov-18 06:50 PM do you have any docs or papers on, like. betatron tuning 19-Nov-18 06:50 PM and i guess like charged particle optics in general 19-Nov-18 06:51 PM i have stuff on betatrons lol. plenty on general charged particle optics 19-Nov-18 06:53 PM Joined the server. 19-Nov-18 06:53 PM i am simultaneously wondering about high current e-beam sources as well as like storage ring dynamics 19-Nov-18 06:53 PM and it comes to mind in particular because someone on twitter tweeted a picture of a .. hold on 19-Nov-18 06:53 PM https://twitter.com/cyanoacry/status/1064005378914930688 this. i have never seen that sort of diagram before 19-Nov-18 06:55 PM here is the classic friction welding in space thing http://www.dtic.mil/dtic/tr/fulltext/u2/a245685.pdf 19-Nov-18 06:55 PM how high current? 19-Nov-18 06:55 PM you can tell its good because they call the space station freedom 19-Nov-18 06:56 PM @qualia I will definitely be releasing builds and info for some very high current ebeam stuff when my chamber is up 19-Nov-18 06:56 PM both low and very high voltage 19-Nov-18 06:56 PM Joined the server. 19-Nov-18 06:57 PM theres some other stuff about the actual advantages of it and outgassing fatigue under thermal stress but that part of my research library not so organized yet 19-Nov-18 06:58 PM What else do you need for your chamber? 19-Nov-18 06:58 PM Hello! 19-Nov-18 06:58 PM :3c 19-Nov-18 06:58 PM honestly, my damn adapter plates are preventing me from really pulling vacuum. I dont have the money to get them machined right now 19-Nov-18 06:58 PM they are simple designs, but I dont have the machining to do them myself 19-Nov-18 06:59 PM Oh, the ones you machined a groove into? 19-Nov-18 06:59 PM or wanted to 19-Nov-18 06:59 PM I switched from conflat to just flat surface for the top one 19-Nov-18 06:59 PM but yeah, those 19-Nov-18 06:59 PM the top one uses over-compression, I increased it from about 30% to almost 50% to help decrease permeation 19-Nov-18 07:00 PM Just surface finish problems? 19-Nov-18 07:00 PM no, just getting them machined lol 19-Nov-18 07:00 PM it will cost about $200 per plate 19-Nov-18 07:00 PM cheapest in my area 19-Nov-18 07:00 PM x2 plates 19-Nov-18 07:01 PM that seems annoying and excessively pricey 19-Nov-18 07:01 PM surface finish is standard 32 microinch for o-ring surfaces. ATP-5 already comes with 25 microinch or better 19-Nov-18 07:01 PM yeah lol, its the major cost constraint going forward 19-Nov-18 07:02 PM so, like, why not conflat? 19-Nov-18 07:02 PM i kinda wonder if you could just.. weld a zero-length flange into a mounting plate 19-Nov-18 07:02 PM I am adapting between diff pump and baffle, then baffle to chamber. getting conflat specs machined are atrocious 19-Nov-18 07:02 PM possibly much cheaper 19-Nov-18 07:02 PM ohh 19-Nov-18 07:03 PM the tolerances for cnflats are incredible. got several papers from cern on that subject lol 19-Nov-18 07:03 PM I also don't have welding either 19-Nov-18 07:03 PM or machining 19-Nov-18 07:03 PM Vacuum welding is hard as well 19-Nov-18 07:03 PM so, like, none of those are ASA or any ~standard fitting? o .o 19-Nov-18 07:03 PM sure, but i imagine this would be welding to the (less critical?) outside of the flange, nowhere near the critical knife edge region 19-Nov-18 07:04 PM yeah that takes serious skill. The diff pump is standard ASA, but I need a custom design to mount with my baffle 19-Nov-18 07:04 PM but then i don't know if that would have the potential to warp or damage things 19-Nov-18 07:04 PM hm, hrm. 19-Nov-18 07:04 PM moot point, then 19-Nov-18 07:05 PM yeah, its the cost of getting cheap stuff on ebay and free parts lol 19-Nov-18 07:05 PM mating them all is the challenge 19-Nov-18 07:05 PM Joined the server. 19-Nov-18 07:06 PM Hello! 19-Nov-18 07:07 PM are tolerances like extremely narrow with this stuff or is machining just inaccessible for some other reason 19-Nov-18 07:07 PM both 19-Nov-18 07:07 PM i've spent as much on CF zero-length converters as like the entire 6" cross that is my chamber 19-Nov-18 07:07 PM and awful materials 19-Nov-18 07:07 PM unless you are specifically set up for machining conflat, its a bear 19-Nov-18 07:07 PM no idea what conflat is 19-Nov-18 07:08 PM @whitequark 's opinion is that machining in the US is just stupidly overinflated in terms of cost and i can kinda believe it, from trawling taobao for cheap KF hoses and stuff 19-Nov-18 07:08 PM im the simpleton rocket engineer who just wandered in 19-Nov-18 07:08 PM Joined the server. 19-Nov-18 07:08 PM when i get gun parts made its really not very expensive 19-Nov-18 07:09 PM actually, the papers I have on conflat tolerancing are in the Vacuum Technologies folder that @AdamMcCombs shared that I sent 19-Nov-18 07:09 PM Joined the server. 19-Nov-18 07:09 PM howdy 19-Nov-18 07:10 PM here is a quote on tolerancing from one of the papers: "The knife edge diameter should better within 0.1 mm, the knife edge radius not bigger than 0.2 mm and the eccentricity should be held be within 0.1 mm related to the flange middle axis. The recess for the gasket should be tolerated to within 0.05 mm related to middle axis of the flanges. The sealed surfaces must not have any marks, scratches or dumps. And the sharp tolerance of sealing surfaces should be within 0.05 mm. And finally the knife edge angles should not be smaller than 90 °" 19-Nov-18 07:10 PM this might be an extrovert advantage thing because with the firearms work i usually know someone who can make it already and dont have to do things professionally 19-Nov-18 07:10 PM conflat is this standard for sexless ultra high vacuum connecting flanges that use a one-time-use metal-to-metal-to-metal sealing mechanism with a knife edge machined into the edge of the sealing surface 19-Nov-18 07:10 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screen_Shot_2018-11-19_at_7.09.30_PM-9D662.png 19-Nov-18 07:11 PM metal to metal to metal 19-Nov-18 07:11 PM Joined the server. 19-Nov-18 07:11 PM also the basic profiles I drew up for one of the manufacturers for a quote: 19-Nov-18 07:11 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Conflat_Knife_Edge_Angles_and_Radii-FD50C.jpg 19-Nov-18 07:11 PM There are two variations however, I forget which standard this is 19-Nov-18 07:11 PM i am a simple man. i aspire to build a sputter coater that i can use to ruin various things, shinily 19-Nov-18 07:11 PM units in mm? 19-Nov-18 07:11 PM Joined the server. 19-Nov-18 07:12 PM inch. I modified it a bit to reduce tolerances since I was using viton 19-Nov-18 07:12 PM https://www.phy.cam.ac.uk/research/research-groups-images/sp/images/mbe1.png conflat is used extensively in Extremely Science Machines, and it has very distinctive bolt counts and ratios that make it easy to spot once you know what it looks like 19-Nov-18 07:12 PM oh 19-Nov-18 07:12 PM so that diagram is not the full tolerances, my bad 19-Nov-18 07:12 PM thats wider tolerances than some of my reloader parts 19-Nov-18 07:12 PM Large Science Accelerator 19-Nov-18 07:12 PM yeah, I widened the tolerances in that diagram 19-Nov-18 07:13 PM sig hook us up we're a bunch of cheap bastards in need of carefully constructed SS316L disks and tubes 19-Nov-18 07:13 PM also hi @iximeow & @atomicthumbs c: 19-Nov-18 07:13 PM and @hillexed ! 19-Nov-18 07:14 PM i dont think i can effectively subsidize vacuum twitter however i can facilitate some networking 19-Nov-18 07:15 PM (mostly joking but by all means,) 19-Nov-18 07:15 PM hi vacuum twitter is very interesting but also i don't know vacuums so i lurk 19-Nov-18 07:15 PM the 70 degree angle is the tricky bit there, i think setup to have anyone i know do that would cost me like $1k and the units would be like $100 each 19-Nov-18 07:16 PM yeah, blanks with that edge go for that much or less brand new, depending on diameter 19-Nov-18 07:17 PM Vacuum looks enticing, but I got a mostly functional 3d-printer and a bunch of chem labware I should rather play with while I still don't earn money 19-Nov-18 07:17 PM vacuum tech is a great way to suck up all your money 19-Nov-18 07:17 PM if the geometry of the bottom of that cut doesn't matter it would be cheaper but presumably this is a high precision standard for a reason 19-Nov-18 07:19 PM @qualia astronomy works too 19-Nov-18 07:19 PM space. the final vacuum 19-Nov-18 07:19 PM pump that mess down 19-Nov-18 07:21 PM i went for a walk a few days ago and ran into the 2012 libertarian candidate for governor (who i have met before at a university physics conference) out with this ornate hexagonal wooden telescope staring at a half moon 19-Nov-18 07:21 PM that mans look is not very coherent but he is a character 19-Nov-18 07:26 PM Joined the server. 19-Nov-18 07:27 PM hiii c: 19-Nov-18 07:27 PM ok my head hurts i'm gonna go home and hunt leaks and maybe wire up some relays 19-Nov-18 07:27 PM @goopypanther i actually own that first book it's really good, but ty!! 19-Nov-18 07:29 PM yay 19-Nov-18 07:30 PM oh they're companion books :o NEAT 19-Nov-18 07:30 PM yeah my specific high-current e-beam interest was FEL design and it's basically right there in the intro so rad 19-Nov-18 07:32 PM o/ hi folks 19-Nov-18 07:33 PM hi! 19-Nov-18 07:37 PM @qualia you looking at FEL design? 19-Nov-18 07:37 PM how would you like to build an actual FEL? 19-Nov-18 07:37 PM im not gonna release too much info yet before my big announcement, but I think you will be very interested in the doors that EXEDA will open up to the maker community. Give me a few months to put together preliminary info for my big announcement... 19-Nov-18 07:42 PM Hi all! I'm here to make my head a vacuum so ambient knowledge rushes into it 19-Nov-18 07:44 PM I recall hearing about that, is it a pulse power source? 19-Nov-18 07:44 PM Also I live in Big New England City so I suspect I'm in prime position to get used equipment out of big universities? How do I do that and would it be helpful? 19-Nov-18 07:47 PM @goopypanther EXEDA is the "big system" I am working on. It is a completely integrated system. vacuum, power, everything. It is also a blueprint, a proof of concept design to be modified based on what others can obtain. I won't release to much info publicly yet, however it will be open source when I begin releasing build info. However, my hopes is that it will completely revolutionize the landscape for accessibility of real particle physics for the maker community. 19-Nov-18 07:58 PM looking forward to it, that sounds cool 19-Nov-18 08:07 PM @hillexed meet people, make connections, show interest, leverage yr expertise. but also depends a lot on being in the right place at the right time too i bet 19-Nov-18 08:07 PM @Applied_Ion mostly just a broad curiosity, esp. wrt: low-cost permanent magnet undulators/wigglers 19-Nov-18 08:16 PM permanent magnets can be used for undulators/wigglers. If you are interested in building a legitmate FEL however, a system like EXEDA would allow you to make one. Won't be like the crazy xray ones at SLAC, but certainly within the microwave frequency range. I will say that the FEL is on my radar and is currently being explored... 19-Nov-18 08:23 PM Joined the server. 19-Nov-18 08:24 PM I have the opposite of a vacuum project 19-Nov-18 08:24 PM give me all of the air you evacuate from your chambers so I can put it in my extremely high pressure chamber 19-Nov-18 08:24 PM Basically I keep reading about gas dynamic lasers 19-Nov-18 08:26 PM are you talking about high pressure gas eximer lasers? like co2 TEA? 19-Nov-18 08:26 PM wait nvm wrong laser 19-Nov-18 08:26 PM the supersonic combustion chamber pumped ones 19-Nov-18 08:26 PM those are awesome 19-Nov-18 08:26 PM lol 19-Nov-18 08:27 PM Joined the server. 19-Nov-18 08:27 PM Basically you can coax rocket exhaust into lasing 19-Nov-18 08:27 PM yeah those are really cool 19-Nov-18 08:28 PM And in my dreams also use it to drive a turbine that pressurizes the fuel 19-Nov-18 08:29 PM I have wondered if the physics for them is scaleable, so you can make them work with small rockets 19-Nov-18 08:29 PM But speaking of TEA, someone at the local hackerspace has been talking about making a multi-kV zinc air battery that is also its own TEA laser 19-Nov-18 08:30 PM not really sure that those two are applicable 19-Nov-18 08:30 PM TEA requires intense and very fast pulses. High pressure systems need tens of kV with ns pulses to work 19-Nov-18 08:30 PM not applicable, directly compatible 19-Nov-18 08:30 PM even low pressure systems require very fast ns pulses, which is why you see them built directly on blumlein transmission lines 19-Nov-18 08:30 PM the larger high pressure ones can be operated with discreet capacitors, but requires it to be geometrically optimized for fast pulses. Batteries aren't good for fast discharges 19-Nov-18 08:33 PM Joined the server. 19-Nov-18 08:34 PM unless the multi kv zinc air battery is used to power the laser by charging the caps, then it would be viable i that sense 19-Nov-18 08:35 PM I think that was the plan 19-Nov-18 08:36 PM that makes sense, though you still probably want at least 10kv min unless it is a really small system with very short gap spacing 19-Nov-18 08:37 PM The idea was for it to be a monolithic block of metal sheets and plastic film that would occasionally flash a UV beam. 19-Nov-18 08:37 PM The optical equivalent to the Oxford electric bell 19-Nov-18 08:37 PM I guess you could probably do that with just a neon tube 19-Nov-18 08:41 PM 'evening vacuum twitter 19-Nov-18 08:41 PM it could work (if I am thinking about it correctly) if the laser portion and fast transmission line/capacitor were on the output of the battery. 19-Nov-18 08:41 PM and evening 19-Nov-18 08:42 PM Yeah 19-Nov-18 08:42 PM Come to think of it, has anyone ever XRF'd the Oxford electric bell battery? 19-Nov-18 08:42 PM Everyone always mentions how they're reluctant to dissassemble it for fear of breaking it. 19-Nov-18 08:45 PM I've never even heard of that thing until now 19-Nov-18 08:46 PM Ye old zappy block 19-Nov-18 08:47 PM Joined the server. 19-Nov-18 08:48 PM o/ 19-Nov-18 09:05 PM Joined the server. 19-Nov-18 09:12 PM @AdamMcCombs d'you have any suggestions on troubleshooting SEM beam issues? 19-Nov-18 09:12 PM *or, I should say, resources that one should consult for that kind of thing 19-Nov-18 09:12 PM Define issues 19-Nov-18 09:13 PM From memory: unable to bring to focus above 1000X, seemingly very low beam brightness at smaller spot sizes. Reasonable image quality at <1000X with "larger" spot sizes and at a range of voltages 19-Nov-18 09:13 PM (Its a fixed aperture, so they do some kind of electromagnetic magic to control the spot size) 19-Nov-18 09:14 PM Yeah spotsize is controlled by the condenser lens 19-Nov-18 09:14 PM Tescan by chance? 19-Nov-18 09:15 PM Philips XL-30 19-Nov-18 09:15 PM Ok similar column 19-Nov-18 09:15 PM (The SEM is down right now so I don't want to bother you for "interactive" troubleshooting; I just figured I'd ask if you knew good resources for when I'm trying to bring it back up) 19-Nov-18 09:15 PM My resources are pretty much my experience... 19-Nov-18 09:16 PM Hah, fair enough! 19-Nov-18 09:16 PM But that sounds normal actually 19-Nov-18 09:16 PM It's kinda the point of spot size 19-Nov-18 09:16 PM Does it feel unreasonably bad compared to normal or is it worse than normal? 19-Nov-18 09:17 PM Unfortunately I don't have a reference point as to normal. The machine was broken when I acquired it, and I haven't had a chance to run any other than my own 19-Nov-18 09:17 PM At the smallest spot size; I'm unable to get an image out of the noise even at multi-minute-per-frame integration times 19-Nov-18 09:18 PM Yeah that seems pretty normal 19-Nov-18 09:19 PM (By broken, I mean more broken than it is now; the vacuum control electronics had failed due to a design flaw, and needed to be fixed before I could even get the machine up) 19-Nov-18 09:19 PM You only drop spot size as you increase magnification and need it 19-Nov-18 09:19 PM 1000x you should probably be at full spot size 19-Nov-18 09:19 PM What was wrong with vac system? 19-Nov-18 09:21 PM Short story, philips chose the wrong PTC for inductive kick suppression on the diff pump and roughing pump contactors, which failed shorted and took out traces and drive transistors on the PLCB. Long story is http://beta.david.carne.ca/blog/xl30_relays/ if you want to read details 19-Nov-18 09:22 PM Do you have the service manuals? 19-Nov-18 09:23 PM I have some, but not all 19-Nov-18 09:23 PM Anyhow, my biggest issue is probably just knowing what is "normal" and when it is operating as it should! I might be expecting too much out of the machine. 19-Nov-18 09:25 PM xl30 is a nice machine with a lot of probe current 19-Nov-18 09:25 PM I just have the tungsten filament variant; but thats probably a good thing for a vacuum/SEM novice like myself 19-Nov-18 09:25 PM Its got as good of performance as any other W based instrument 19-Nov-18 09:25 PM yeah don't touch field emission unless you don't like your money. 19-Nov-18 09:32 PM Its also possible that I wasn't leaving it pumped down long enough. Where I had it before, I wasn't allowed to leave the pumps on 24/7. Once I finish construction where I am now, I should be able to leave it on all the time budget allowing. So fingers crossed some of the image quality issues were just due to a poor vacuum. 19-Nov-18 09:32 PM So degraded quality even at 1000x? 19-Nov-18 09:33 PM Let me see if I can dig up some images 19-Nov-18 09:33 PM A skilled operator can take a xl30 to just north of 100kx 19-Nov-18 09:37 PM This is a terrible image (picture of a screen) and I apologize for linking it; but its all I have at the moment: https://photos.google.com/share/AF1QipPIJTkoLfsWRPj-jJQ74q1J4c3HReTJ2HXmf-pKzsYHRUoC-H87CIUEOEe1VUHhLQ?key=NXR3VHRRcEdaaVZGV280UUpMRU9yRlNZRWM4MUlB 19-Nov-18 09:37 PM Stig looks a bit off 19-Nov-18 09:37 PM What was measured probe current? 19-Nov-18 09:39 PM Things are a bit better at 30kv https://photos.app.goo.gl/9ydGWHRMeZVayhvEA , but I can't always convince it to work there. 19-Nov-18 09:39 PM You need to condition the gun 19-Nov-18 09:39 PM Id say get more practice running it 19-Nov-18 09:41 PM Yeah. I'm gonna get it back together, and leave it pumped down for a while. I added a vacuum gauge to the chamber so I know the actual chamber pressure, so hopefully I can rule that out. Could quite possibly just be all due to operator error! 19-Nov-18 09:41 PM (Weirdly, they don't actually have a chamber vac gauge on this model. They measure on the roughing side and estimate based on expected diff pump performance) 19-Nov-18 09:58 PM You sure about that? 19-Nov-18 09:58 PM You may just need to go to the dac page 19-Nov-18 10:15 PM Yup, its physically not present. 19-Nov-18 10:15 PM No physical gauge, no penning gauge (HVG) card, and the manuals say one isn't present in the W model 19-Nov-18 10:15 PM only in the LaB6 and Schottky models 19-Nov-18 10:17 PM hm 19-Nov-18 10:17 PM I might have those 19-Nov-18 10:17 PM or access to them 19-Nov-18 10:36 PM Joined the server. 19-Nov-18 10:42 PM Welcome all newcomers! 19-Nov-18 10:45 PM Joined the server. 19-Nov-18 10:48 PM υωυ 19-Nov-18 11:07 PM Joined the server. 19-Nov-18 11:07 PM has anyone reverse engineered the pinouts for the IGM400 ion vac gauge so it can be used without the controller? 19-Nov-18 11:15 PM @qualia and @GigaSquirrel have, I think 19-Nov-18 11:35 PM Joined the server. 19-Nov-18 11:36 PM Joined the server. 19-Nov-18 11:36 PM Hello! 19-Nov-18 11:37 PM Joined the server. 19-Nov-18 11:41 PM Joined the server. 19-Nov-18 11:41 PM Hi 19-Nov-18 11:45 PM hello 19-Nov-18 11:45 PM welcome to the server 19-Nov-18 11:46 PM thx 19-Nov-18 11:46 PM Tnx 20-Nov-18 12:06 AM yawn 20-Nov-18 12:06 AM wow, so many new people! 20-Nov-18 12:06 AM welcome to all of you! 20-Nov-18 12:09 AM /welcome party dance/ 20-Nov-18 12:10 AM 20-Nov-18 12:10 AM That's the same icons my Gf uses when she is on her period...very weird thoughts just crossed my mind... 20-Nov-18 12:13 AM [Time zone greeting] all. 20-Nov-18 12:13 AM Because, well, we have time zones. 20-Nov-18 12:14 AM Indeed. 20-Nov-18 12:14 AM In germany we have the universal "moin", which originated von "morgen" (morning) but is now used by most people at all times of the day 20-Nov-18 12:17 AM universal greeting time 20-Nov-18 12:17 AM yep, moin! 20-Nov-18 12:24 AM Raise your hand if you have a whole workshop to clean. /his hand shots up, making a hole in the ceiling/ 20-Nov-18 12:25 AM cough 20-Nov-18 12:25 AM raises hand 20-Nov-18 12:25 AM not only the workshop... 20-Nov-18 12:25 AM this is a test 20-Nov-18 12:26 AM Bahaha 20-Nov-18 12:26 AM heh, nice 20-Nov-18 12:27 AM I have only understood the "this is a test" 20-Nov-18 12:27 AM it tried saying my name before that 20-Nov-18 12:27 AM sounded more like "cheetahbecquerel" 20-Nov-18 12:29 AM XDDDD 20-Nov-18 12:38 AM there is a helium compressor on ebay.com for <$300 20-Nov-18 12:39 AM Can we see? 20-Nov-18 12:39 AM and $800 for shipping to me >.< 20-Nov-18 12:39 AM (ok everyone remember the no sniping rule) 20-Nov-18 12:39 AM https://www.ebay.de/itm/192533701889 20-Nov-18 12:39 AM (I'm not here, I'm cleaning my workshop /moves hands in the air) 20-Nov-18 12:39 AM I'm not gonna buy it, feel free to do so 20-Nov-18 12:39 AM Ah, USA 20-Nov-18 12:39 AM yep 20-Nov-18 12:39 AM and with that much shipping customs will be pretty expensive, too 20-Nov-18 12:40 AM its still 300 shipping in the us... 20-Nov-18 12:40 AM meh 20-Nov-18 12:40 AM why is it so damn expensive to get my hands on one 20-Nov-18 12:41 AM <9600#6712> Joined the server. 20-Nov-18 12:41 AM oh hey 20-Nov-18 12:42 AM Moin! 20-Nov-18 12:43 AM And I just looked up curve tracers...damn 20-Nov-18 12:43 AM Oh...https://www.ebay.com/itm/I-V-Curve-Tracer-adapter-XY-mode-Oscilloscopes-for-components-testing/142250242804?epid=2032801456&hash=item211ec672f4:g:YAkAAOSwUKxYf7C0:rk:24:pf:0 20-Nov-18 12:44 AM pretty sure that's just the octopus 20-Nov-18 12:45 AM Yeah, I would just like to not build it. 20-Nov-18 12:45 AM XDDD 20-Nov-18 12:46 AM fair 20-Nov-18 12:46 AM I got one of those made by hameg for cheap 20-Nov-18 12:46 AM you could look out for that one, it's a "Component tester HZ 65" 20-Nov-18 12:49 AM No results, but I get the idea 20-Nov-18 12:49 AM I'll look into them next month. 20-Nov-18 12:51 AM and now go clean your Workshop, stop procrastinating :P 20-Nov-18 12:53 AM Yes, dad. 20-Nov-18 12:53 AM XDDDDD 20-Nov-18 12:54 AM :D 20-Nov-18 01:34 AM Do u guys build particle accelerators? 20-Nov-18 01:36 AM I mean ish? 20-Nov-18 01:36 AM Well actually definitely yes 20-Nov-18 01:37 AM I guess a fusor is a spherical accelerator, so yes 20-Nov-18 01:37 AM I mean I think a 300kv tem counts? 20-Nov-18 01:38 AM definitely 20-Nov-18 01:40 AM Ion implanters count too, right? 20-Nov-18 01:42 AM Yep 20-Nov-18 01:42 AM Yep to all of them \o/ 20-Nov-18 01:42 AM Are there ongoing projects? 20-Nov-18 01:42 AM Especially ion implanters 20-Nov-18 01:47 AM Not yet, first i have to finish basic semiconductor processes. 20-Nov-18 01:48 AM And how to not die from nasty gasses 20-Nov-18 01:50 AM 20-Nov-18 01:50 AM @Applied_Ion maybe knows 20-Nov-18 01:50 AM I need a badge that says "Handled 72% HF and didn't die, yet" 20-Nov-18 01:54 AM Can’t I use lesser toxic dopant sources than posphine or boron trifluoride for Si doping? 20-Nov-18 01:56 AM iirc the HF is not for doping but etching 20-Nov-18 01:56 AM I mean, an ion implanter is also a spectrometer, so ... I dunno 20-Nov-18 01:56 AM Yeah HF is for Isotropic etching 20-Nov-18 01:58 AM Yes, I was just saying I have handled true deadly things before. 20-Nov-18 01:59 AM PH3 (phosphine) and BF3 (boron trifluoride) are often used as dopant sources at ion implanters 20-Nov-18 01:59 AM I have this weird plan for a "solid state" ion implanter. 20-Nov-18 01:59 AM Solid state accelerator? 20-Nov-18 01:59 AM Wakefield style? 20-Nov-18 02:00 AM Sounds fancy, Its this weird idea to fuse a sputtering machine with acceleration hardware, so I can produce the ions from solid sources instead of those gases. 20-Nov-18 02:00 AM Ah, ok 20-Nov-18 02:00 AM Yeah I guess solid dopant ion sources are built before - so should be feasible 20-Nov-18 02:00 AM There are paper about 20-Nov-18 02:02 AM Don't take my word on it, my mind just wanders easily. 20-Nov-18 02:02 AM Question is what are the downsides in practice 20-Nov-18 02:02 AM I would strongly prefer not using phosphine et al 20-Nov-18 02:05 AM Me too 20-Nov-18 02:05 AM Will let you know when I try it. 20-Nov-18 02:07 AM But first steps are accelerator, analyser, beam line & optics? 20-Nov-18 02:10 AM I guess. Wait for the experts to show up, they will answer much better. 20-Nov-18 02:10 AM Joined the server. 20-Nov-18 02:10 AM Welcome! Great nick, btw. 20-Nov-18 02:11 AM Moin! 20-Nov-18 02:15 AM I suppose in principle there’s no reason why you couldn’t do doping or PECVD with a solid reagent as long as you could volatilise it / react it once inside the chamber 20-Nov-18 02:15 AM It’s Luke btw 20-Nov-18 02:15 AM Liquid spin on glass is interesting stuff - I’ve never used it though 20-Nov-18 02:15 AM http://desertsilicon.com/products/spin-on-glass-applications/ 20-Nov-18 02:15 AM What does Sam use? Phosphoric acid and boric acid maybe? 20-Nov-18 02:15 AM Maybe triphenylphosphine or diphenylphosphine since they are used in organic chemistry as safer “phosphine carriers”. 20-Nov-18 02:25 AM For boron he is using boric acid, but it's a pain in the ass. 20-Nov-18 02:26 AM Joined the server. 20-Nov-18 02:26 AM (it makes t covering layer of borisilicate glass, and you have to get rid of it) 20-Nov-18 02:29 AM Hi, meowter! 20-Nov-18 02:56 AM @a_quiet_scientist should ask for samples of spin on dopants. 20-Nov-18 03:00 AM Joined the server. 20-Nov-18 03:05 AM Hello, crabs! 20-Nov-18 03:15 AM Hi 20-Nov-18 03:21 AM Joined the server. 20-Nov-18 03:27 AM Welcome, fib! 20-Nov-18 04:05 AM Joined the server. 20-Nov-18 04:08 AM Hello, nurelin! 20-Nov-18 04:10 AM Joined the server. 20-Nov-18 04:14 AM And hello to you, too, robmacl! 20-Nov-18 04:15 AM hello 20-Nov-18 04:19 AM Hi! Current project is multi layer optical coating for iridescence effects. 20-Nov-18 04:19 AM /applauds/ 20-Nov-18 04:19 AM Today at around 5pm (madrid/paris timezone) I'll be livestreaming my semicon oven refurbish, in case anyone wants to join. 20-Nov-18 04:35 AM https://www.pscp.tv/nixie_guy/follow 20-Nov-18 04:40 AM ^^ moin 20-Nov-18 04:40 AM Tach auch! 20-Nov-18 04:41 AM It's definitely regional. I haven't heard it used that way more than twice 20-Nov-18 04:42 AM Wow, ok 20-Nov-18 04:42 AM it's very common in the northern parts 20-Nov-18 04:44 AM Yeah, I associated it more with nrw and north of it 20-Nov-18 04:45 AM but it's starting to drift downwards, as you can see it has already reached bavaria 20-Nov-18 04:48 AM I can get behind this trend. 20-Nov-18 04:50 AM great! 20-Nov-18 04:53 AM Though I just realised I often greet people with "morgen" regardless of the time of day 20-Nov-18 04:55 AM Joined the server. 20-Nov-18 04:55 AM this is how it starts! 20-Nov-18 04:55 AM …person walks in in the early afternoon: "moin" Apparently I just don't listen (to what people greet me with) 20-Nov-18 04:55 AM Hi, frisnit! 20-Nov-18 04:56 AM (on the other hand: they were a student, so it might very well be early in the day for them) 20-Nov-18 04:56 AM /listens to the treatise about how to greet people/ XD 20-Nov-18 04:57 AM that's pretty early for a student to wake up 20-Nov-18 06:45 AM Things I love waking up to - discussions about accelerators. Things I hate waking up to - changing a flat tire while it's snowing on a workday... 20-Nov-18 06:45 AM @N00N you looking to build an accelerator? 20-Nov-18 06:49 AM Moin! 20-Nov-18 06:50 AM @Nixie technically accelerators that use "solid" starting ions do exist. For heavy ions usually the solid target is melted or vaporized. Classic example is cesium for negative ion sources 20-Nov-18 06:50 AM Morning! 20-Nov-18 06:50 AM For classical ion beam milling with gallium, the starting ions are evaporated from a solid source as well 20-Nov-18 06:50 AM Well, technically gallium is liquid at room temperature, so more of a liquid metal ion source 20-Nov-18 06:58 AM @Applied_Ion I would like to build an ion implanter 20-Nov-18 06:58 AM What voltage and current level we talking? 20-Nov-18 06:58 AM Also what ions 20-Nov-18 06:59 AM Dunno, what’s feasible, I guess 20-Nov-18 06:59 AM If MeV with enough current is possible, I would 20-Nov-18 07:00 AM Depends on your end goal and application lol. Any accelerated ion with high enough energy will be implanted. Depth and concentration, as well as sputtering and damage depends on energy, ion, and target 20-Nov-18 07:00 AM I will say MeV at tens to hundreds of amps is possible 20-Nov-18 07:01 AM For Si P, B , H & O are common 20-Nov-18 07:01 AM However you will have to wait on the details a bit for MeV stuff... 20-Nov-18 07:01 AM (H and O for processing not doping) 20-Nov-18 07:02 AM How deep do you need to implant? 20-Nov-18 07:02 AM Also, have you used SRIM? 20-Nov-18 07:02 AM That is exactly the program used for calculating and simulating this stuff 20-Nov-18 07:02 AM I kno 20-Nov-18 07:02 AM Question is, what is possible 20-Nov-18 07:04 AM It would be best to first determine your end goal. Depth, concentration, ions, etc. Then you can simulate ion source needed, and you will know what level accelerator you need 20-Nov-18 07:04 AM I have a more advanced example of SRIM/TRIM on my website looking at using custom input files for more advanced simulation. This one explores DC glow discharge cleaning using the Davis and Vanderslice ion energy distribution for DC plasmas 20-Nov-18 07:04 AM http://appliedionsystems.com/portfolio/trim-simulation-of-sputtering-and-implantation-from-dc-glow-discharge-plasma-in-stainless-steel/ 20-Nov-18 07:04 AM however, the basic principles can be applied to any ion source, especially beams. Simple simulations look at monoeenrgetic sources, but for more accurate simulations you can input an energy distribution 20-Nov-18 07:07 AM Most ion implanters are using small LINAC 20-Nov-18 07:07 AM note that for ion sources, if you put in lets say 100kV, your resulting ion energies will not be at that energy, but some general gaussian distribution below that, with peak tail at the 100kev range 20-Nov-18 07:10 AM And you need an analyser, maybe it’s possible to build an cyclotron which inherently analyzes, but maybe one get probs with sputtered material from the cyclotron electrodes? 20-Nov-18 07:10 AM Goal is a pure ion beam (isotopically and energy, right?) 20-Nov-18 07:13 AM yes, but what's your budget lol. that stuff adds up in not only cost, but expertise, and difficulty building 20-Nov-18 07:13 AM analyzers are relatively straigthfowrad to build 20-Nov-18 07:13 AM I know there are a couple of cyclotron based ion implanters 20-Nov-18 07:14 AM adding all this stuff to a beamline adds components and size 20-Nov-18 07:14 AM Yep 20-Nov-18 07:14 AM honestly, while amateur cyclotrons are a great way of looking at the physics, its not very practical for high energies. The size, weight, and shear power you need for the magnets just to get lousy energy beams isn't worth it in my opinion 20-Nov-18 07:14 AM actually, in all of my research, I have come across really only one truly viable and cheap way for intense MeV ion beams. It is a very old and forgotten accelerator technology, but is the only way that is really feasible at amateur budgets. Granted the energy spread is huge, but thats what downstream optics are for. 20-Nov-18 07:18 AM Tandem or what? 20-Nov-18 07:18 AM and again it really goes back to what you are trying to explore. Are MeV ions really needed? the implantation depth is every deep, not to mention damage that can occur, as well as radiation yields as well 20-Nov-18 07:18 AM no, if you are thinking van de graaf or cockroft walton for MeV ions on a budget, forget it lol. Especially VDG, to get any appreciable current it has to be a very large and highly engineered system. Really requires a pelletron topology at that level to be viable. Not something that is feasible on the maker budget 20-Nov-18 07:18 AM and cockroft walton are good for a couple hundred kev practically, but getting higher is a massive challenge, and parts get very expensive. Plus you have high losses with too many stages, even running more efficiently at high frequencies 20-Nov-18 07:27 AM Ah ok 20-Nov-18 07:33 AM I would say research into the tech more. explore what energy ranges are needed, and why they are needed. Also think about your experiment and what you want to accomplish. List out the parameters and objectives. Maybe look into lower energy proof of concept experiments first to get a feel for what is involved. also if you are serious about it then SRIM is a must. there are two versions out, 2008 and 2013. I would recommend downloading 2013. It is free, and extraordinarily powerful. Pretty much a standard in research and industry. It is often cited in academic papers, textbooks, and industrial papers for anything implantation, sputter, and damage related. 20-Nov-18 07:33 AM i have used it a bunch myself, and will be using it a lot going forward in the future as well 20-Nov-18 07:33 AM while it looks easy on paper, it is still a massive undertaking. each subsystem is its own complete field itself. The vacuum system, injector, accelerator, optics, and overall control require a lot of engineering and research. It's definitely do-able, but you gotta be in it for the long haul. There are a lot of free programs out there for simulation which is a huge bonus too, but they range in complexity to use, and all have learning curves. If you can stick it through from start to finish however, you will be an expert in many fields. But it most likely will be a process over several years, unless you have a massive budget and a huge amount of free time 20-Nov-18 07:33 AM but you can still make smaller scaled systems and experiment with the technology. It doesn't need to be a full-blown MEV ion implanter for it to be a useful research tool 20-Nov-18 07:40 AM Yeah, okay, I understand 20-Nov-18 07:45 AM if you need any help with srim, let me know, I can provide some pointers. I can also dig through my resources to see if I have stuff on implantation as well. 20-Nov-18 07:45 AM and of course on ion gun and optics. I still gotta figure out how to get the free ion beam simulation software running though. I know how to use simion a bit, but I don't have access to it outside of work. IBSIMU is a very powerful free software that does ion beam extraction from plasmas as well as optics, but just installing it is a horrible ordeal. It is also a text/code based input program, not user fiendly with very little documentation. 20-Nov-18 07:48 AM Joined the server. 20-Nov-18 07:49 AM if you are feeling really adventurous and desperate, you could always do what they did in the old days before all of these simulation codes, and use an electrolytic tank, but this is something even I am trying to avoid. 20-Nov-18 07:51 AM No electrolytic tank analogy simul please 20-Nov-18 07:51 AM Joined the server. 20-Nov-18 07:51 AM though the best way may be to design and buidl something as best you can with your resouces, power it up, and see what happens. A simple faraday cup, energy analyzer, and other beam profile diagnostics can be built and used easily to detemine rough qualities about your system, then tweak the design as you go. Iterative experimental design 20-Nov-18 07:51 AM We’ve computers in 2018!111 20-Nov-18 07:51 AM Yea “simple” linac and go? 20-Nov-18 07:55 AM no need to get into a whole linac from the start. The gun itself is already massively involved as is. And you can make a very simple gun to experiment with and do diagnostics on. I am actually looking at exploring miniaturized intense beams with my small 2.75" conflat chamber, and seeing how high energy and current I can dump into such a small form factor. My goal is at least a min of 100kev beams at hundreds of amps with that small setup. 20-Nov-18 07:55 AM even a small 10kv gun is more than enough to use for beam diagnostic development 20-Nov-18 07:55 AM technically, even guns themselves are accelerators. There are accelerators how there that are just very high power stand-alone injectors. No RF/DC or additional accelerating mechanisms beyond the gun itself. 20-Nov-18 08:16 AM True, but with RF the fun begins, or? 20-Nov-18 08:16 AM 100keV with 100s of A? 20-Nov-18 08:16 AM Neat 20-Nov-18 08:16 AM At what pulse length? 20-Nov-18 08:25 AM https://www.pscp.tv/w/1vAxRylZABNJl @Nixie is streaming! 20-Nov-18 08:39 AM I'm not using RF for any of my stuff. Pulse widths will vary from uS to nS. Microsecond is with the primary stage just calacitors, nanosecond is with pulse compression to get higher peak current and increase peak power 20-Nov-18 08:39 AM Also awesome! 20-Nov-18 08:39 AM Almost lunch break now, so maybe I can catch the livestream then 20-Nov-18 08:50 AM Joined the server. 20-Nov-18 08:50 AM 大家好 20-Nov-18 08:50 AM ！！！ 20-Nov-18 08:50 AM So, who all is everyone? Think I recognize most of the Twitter peeps I know, but I'm curious if there are others with different discord handles? 20-Nov-18 08:55 AM I have the same name here and on twitter 20-Nov-18 08:56 AM I have the same here as well 20-Nov-18 09:01 AM Joined the server. 20-Nov-18 09:30 AM Joined the server. 20-Nov-18 09:30 AM Cheers 20-Nov-18 09:30 AM I'm mostly gona lurk here. Work does stuff that includes turbo pumps and cryocoolers. 20-Nov-18 09:36 AM Joined the server. 20-Nov-18 09:36 AM Lurker here too. Someday I'll build a RF vacuum (wood) kiln. 20-Nov-18 09:41 AM I actually should ask at work if one fried pheiffer vacuum gauge got repaired or not 20-Nov-18 09:41 AM Because I'd love me one. And having over inflated expectations of my own skills, I'm sure I can repair it. 20-Nov-18 09:48 AM wow, this roomis getting pretty crowded ! 20-Nov-18 09:50 AM Yeah. 20-Nov-18 09:50 AM We're sorta beginining to propose to create specific channels so people don't get lost in the general chat with a few simultaneous chats. 20-Nov-18 09:58 AM thats probably a good idea. already a bunch of chats on vacuum, accelerators, ion guns, etc all mixed together 20-Nov-18 10:01 AM Yep. Whe're waiting for Mom (Mx) and Dad (Adam) to give permission. 20-Nov-18 10:55 AM Joined the server. 20-Nov-18 10:55 AM To all the new people: Is anyone here familiar with repairing HPGe detectors? 20-Nov-18 02:06 PM Don't know the acronym but I do know electronics 20-Nov-18 02:06 PM So if you need advice on troubleshooting I can provide @GigaSquirrel 20-Nov-18 02:07 PM High purity germanium detector 20-Nov-18 02:07 PM https://www.caensys.com/wp-content/uploads/2017/02/hpge-400.jpg One of those suckers 20-Nov-18 02:09 PM Yeah ok, what are you detecting? 20-Nov-18 02:09 PM nothing, that's the issue xD 20-Nov-18 02:09 PM Ok, let me rephrase: what are you /supposed/ to be detecting 20-Nov-18 02:10 PM it's basically a huge PIN diode cooled down to LN2 temps for gamma detection 20-Nov-18 02:10 PM Idk what HPGe detectors are supposed to be for 20-Nov-18 02:10 PM Ah, ok, so it's an interaction-count type of thing? And I'm assuming you have a predictable source to test with? 20-Nov-18 02:11 PM and either both the Ge crystal and internal PT100 sensor are broken in mine or for some reason it dosen't cool down properly 20-Nov-18 02:11 PM I'm assuming you probably want to find a fix without cracking it open? 20-Nov-18 02:11 PM it's used in gamma spectrometers as detector 20-Nov-18 02:11 PM yep 20-Nov-18 02:12 PM Hhhh 20-Nov-18 02:12 PM or at least find some photos what's inside, I've never seen one taken apart 20-Nov-18 02:12 PM Sensor repair without debug points is a pain :/ 20-Nov-18 02:12 PM What does it output for data? Raw analog signal? Or some digital count metrics? 20-Nov-18 02:13 PM and since these things cost more than 2 kidneys and half a lung I'd like to prepare myself well before opening it 20-Nov-18 02:13 PM Yeah, yeah, I think that's reasonable 20-Nov-18 02:13 PM analog signal, a cooled fet detects current through the crystal, a small preamp amplifies that 20-Nov-18 02:13 PM the crystal has to be cooled , otherwhise the intrinsic region conducts to well, resulting in extreme noise 20-Nov-18 02:13 PM my crystal is pretty conductive after filling the dewar with ln2 and waiting a couple of hours, the internal PT100 never shows a temperature below -70°C 20-Nov-18 02:13 PM we're talking about ~20 fC per detection event btw 20-Nov-18 02:20 PM I have no idea what I'm talking about, but assuming the ln2 circulates in the part sticking out (right side of image) couldn't you tape another PT100 to it and wrap insulation around that part and wait for the temp to drop? 20-Nov-18 02:20 PM If it agrees with the internal PT100, perhaps there's something blocking circulation? 20-Nov-18 02:21 PM If I got it right there is a copper rod going from the dewar to the front 20-Nov-18 02:21 PM everything under vacuum for insulation 20-Nov-18 02:21 PM with a weird-ass pump connector 20-Nov-18 02:22 PM Can you xray it? 20-Nov-18 02:23 PM huh, yeah, I didn't think of that yet 20-Nov-18 02:23 PM it's all al, so it should not be a problem that my x-ray is only 70 kV 20-Nov-18 02:23 PM actually the dewar itself is built very interesting 20-Nov-18 02:28 PM I'd be really interested in seeing x-ray pics, but I'd maybe start at lower energy? Just to be safe in case there's anything that would be sensitive in there? 20-Nov-18 02:28 PM it is only pumped down to ~e-3 mbar and has some adsorber in it, functioning as cryo pump once it is filled with LN2, resulting in a low maintenance good high vacuum for insulation 20-Nov-18 02:28 PM Can't think there would be but can't hurt to be careful 20-Nov-18 02:28 PM the thing is a radiation detector 20-Nov-18 02:28 PM ...right 20-Nov-18 02:28 PM Dub 20-Nov-18 02:28 PM *duh 20-Nov-18 02:29 PM "oh no but what if it's not safe to handle x-rays" "handling x-rays is basically its job" >.< 20-Nov-18 02:29 PM yep ^^ 20-Nov-18 02:35 PM Btw @GigaSquirrel is your username a homestuck reference??? 20-Nov-18 02:36 PM nope 20-Nov-18 02:36 PM didn't even know it was related to homestuck ^^ 20-Nov-18 02:36 PM Fair enough, probably good 20-Nov-18 02:36 PM Homestuck is long-since dead and that's probably a good thing tbh 20-Nov-18 02:37 PM I know some people in the fandom and they basically hate the fandom 20-Nov-18 02:37 PM my first radioactive thing was one gigabecquerel of tritium (one of those keychain lights) and it kickstarted, together with my first geiger counter, my whole hobby 20-Nov-18 02:37 PM hobby, now job and study 20-Nov-18 03:06 PM Never been on a Discord server with such well regarded ppl like all you. Am slightly in awe... 20-Nov-18 03:06 PM Only slightly mind you. 20-Nov-18 03:08 PM Glad you feel that way 20-Nov-18 03:10 PM I am hoping to learn by osmosis. 20-Nov-18 03:10 PM just keep close and some will diffuse through 20-Nov-18 03:47 PM Wait a becquerel is a unit? That explains the joke then >.< 20-Nov-18 03:47 PM 4 years later and now I get the damn reference. 20-Nov-18 03:47 PM I used to do material physics, shouldn't have let that slip by me 20-Nov-18 03:48 PM becquerel is a unit for radioactive decay, 1 Bq equals 1 decay per second 20-Nov-18 03:48 PM That makes sense 20-Nov-18 03:49 PM Can be used just like Hertz, exept that hertz implies a somewhat steady period 20-Nov-18 03:50 PM Well I mean, in radioactive materials, since it's all probablistic, a large lump of material will also have a fairly steady period, no? 20-Nov-18 03:50 PM Also, we do refer to the frequency of semi-random signals using Hertz, at least in EE. We just refer to the more-dominant harmonics to describe the signal 20-Nov-18 03:51 PM the period here would be the time between two decays, and that will always be different 20-Nov-18 03:52 PM How I know it's winter in Massachusetts: in the 4 hours I was at work today, enough snow fell that the whole complex needed plowing twice and noone in the office even cared 20-Nov-18 03:52 PM Huh, funny, we (I'm a physics studend) call everything with constant period Hertz, everything with varying period just eventy per second (1/s) and decay bq 20-Nov-18 03:52 PM we just had our first snow yesterday, it was at most ~3 cm and very uneven coverage 20-Nov-18 03:54 PM Where at? 20-Nov-18 03:54 PM Munich, germany 20-Nov-18 03:56 PM Oh cool, I've heard Germany is lovely in the winter 20-Nov-18 03:57 PM it can be, but last year it just was cold with almost no snow 20-Nov-18 03:57 PM "I am hoping to learn by osmosis." <-- Same 20-Nov-18 03:57 PM We do vacuum & cryo stuff at work, but I'm more involved with the electronics outside of it 20-Nov-18 03:58 PM oh, cool! 20-Nov-18 03:58 PM I'm currently repairing a cryopump ^^ 20-Nov-18 03:59 PM Anyway, yeah, since decay is a probablistic thing, with a normal distribution between events, you end up with an average frequency, basically 20-Nov-18 03:59 PM Tho 1*10^-5 mBar and sub 10 Kelvin are starting to become normal, so my definition of things seems to be evolving 20-Nov-18 03:59 PM @GigaSquirrel I think I saw pictures on twitter, that shattered absorber thing? 20-Nov-18 03:59 PM yeah, on average you get a constant frequency, hence Bq ^^ 20-Nov-18 03:59 PM yep 20-Nov-18 04:00 PM I have only once seen a disassembled cryopump tho 20-Nov-18 04:00 PM charred, molten and shattered 20-Nov-18 04:00 PM A tech from sumitomo did a field refurbishment as a demo on one unit 20-Nov-18 04:01 PM Yeah we'd just refer to that as Hz in EE, the signal you get from a detector is a pseudo-random pulse train and we'd just call that whatever the average frequency is because, here's a secret: 20-Nov-18 04:01 PM EE's are lazy as hell 20-Nov-18 04:01 PM We are! 20-Nov-18 04:01 PM Tho I have so far not gradueted, yet I'm in the industry 20-Nov-18 04:02 PM Honestly now that I'm doing cyber security instead of analog things most of my work is fixing the things lazy CE's did >.< 20-Nov-18 04:03 PM The main job of an engineer is basically to make things easyer, so lazyness has to be a given 20-Nov-18 04:04 PM Ugh, lyft I'm in smells really strongly of cigs :/ 20-Nov-18 04:04 PM ew 20-Nov-18 04:06 PM +1 20-Nov-18 04:18 PM it's getting late, good night 20-Nov-18 04:19 PM o/ good night 20-Nov-18 04:19 PM speaking of cryopumps, i got a chance to tour Aerospace Corp the other day -- i've never been surrounded by cryopumps that were bigger than me before https://www.youtube.com/watch?v=QXqHDDC9BVU 20-Nov-18 04:19 PM given that their electric propulsion test chambers feed lots of xenon i'm surprised that they can rely on cryopumps without them loading up 20-Nov-18 04:19 PM maybe there was another pump type i didn't see 20-Nov-18 04:26 PM Cryo pumps large capacity at high volume. They also have the highest pumping speeds in the world, really the only pump that can handle large electric propulsion engines. Biggest ones can hit the level of a million l/s 20-Nov-18 04:28 PM but if you're dumping in dozens of sccm per minute, does all of that Xe really just stick to the surfaces and never lets go? that's pretty amazing 20-Nov-18 04:32 PM It's all about maximizing surface area. Cryopumps are based on surface area pumping. The walls of some of these chambers are literally just cryo pumping panels 20-Nov-18 05:23 PM I've thought about whether or not I could make a not-really-cryopump by sticking the cold end of a peltier on a conflat blank in my system 20-Nov-18 05:23 PM might work for water vapor, not for much else probably 20-Nov-18 05:24 PM I have also thought of that as well, making a pseudo "cryo" panel with the cold side of a peltier to help pump water vapor 20-Nov-18 05:24 PM Cryo pumping fir other gases only works when the temperatures are cooler than the condensation point of the gas. Water vapor is easy, but other gases require liquid nitrogen or primarily helium 20-Nov-18 05:24 PM Actually, diffusion pump cold traps are essentially used exactly for capturing water vapor in the system, effectively pumping it out 20-Nov-18 05:24 PM They use liquid nitrogen mostly, but if you can get it cold enough through other means then it will work as long as it can freeze out the water 20-Nov-18 05:24 PM I do believe I have read that there are actually thermoelectric cold traps, though rare 20-Nov-18 05:28 PM it's a shame that stacked peltiers have basically no real heat pumping capacity and ridiculous inefficiency 20-Nov-18 05:28 PM Yes, but you shouldn't have a heat load in a vacuum 20-Nov-18 05:29 PM past like two or three stages you get extremely dimishing delta-T returns for either waaay increased hot-side waste heat output or very very small (<5W) cold side heat pumping performance 20-Nov-18 05:29 PM i suppose so 20-Nov-18 05:29 PM You can freeze out water of the atmosphere very fast with a peltier, even a plate on a peltier. As long as there is no real hear load, it should work in the vacuum 20-Nov-18 05:30 PM /wakes up to dog snoring, reads cryopump stuff, smiles/ 20-Nov-18 05:32 PM the last time i touched my thermoelectric cloud chamber project, i swapped out the manually-stacked 12715s for a single tec2-25408 and got about the same results with much less annoying split-voltage power requirements 20-Nov-18 05:32 PM (most of my issues with that are supersaturated-convection-chamber design, at this point... holdin' out for that special glass jar or petri dish that makes it all come together :P) 20-Nov-18 05:33 PM Are they water cooled, and with insulation? 20-Nov-18 05:33 PM I will be building a thermoelectric cloud chamber at some point as well 20-Nov-18 05:33 PM yeah, closed-loop water cooling. not much in the way of insulation though, just a bare cold plate and i've tried tucking bits of foam around the sides to little useful effect 20-Nov-18 05:33 PM hits -30 to -40C pretty quick 20-Nov-18 05:33 PM ideally it'd be more around -70C to be on par with dry ice but it's workable with lots of lighting 20-Nov-18 05:37 PM Having so much vacuum equipment and metal workshop, I think I would try to rebuild a water chiller circuit with a custom cold end, instead of using peltiers. 20-Nov-18 05:37 PM at one point i streamed (on twitch; i think the video's since expired off of there..) getting it working with the old dual-single-stage-and-loud-fan-on-huge-cpu-heatsink setup in the dead of winter in my frigid bedroom. got teeny tiny alpha trails off of a button source 20-Nov-18 05:37 PM i have a huge 2"x2"x0.5" magnet i plan to stick under the next iteration to get ✨ 20-Nov-18 05:37 PM ... but that needs some, like, safety-harness woodworking, or something. it is not a particularly forgiving chunk of ND52 20-Nov-18 05:37 PM ... also, i never did get a DC bias source put together. that'd probably help a lot with trail visibility too. 20-Nov-18 05:37 PM @Nixie i actually picked up a cheap airflow cryocooler from a now-gone local junkstore in hopes of doing exactly that, actually! 20-Nov-18 05:40 PM Yeah, be careful with that magnet. 20-Nov-18 05:40 PM Ohhhhh 20-Nov-18 05:40 PM it will take a gentle stream of gas and fairly effectively and controllably cool it down to.. i think -60C? 20-Nov-18 05:40 PM i am not sure what it was for originally 20-Nov-18 05:43 PM Cool (pun intended) 20-Nov-18 05:44 PM Fun times obviously? 20-Nov-18 05:44 PM Joined the server. 20-Nov-18 05:44 PM definitely something exciting :D 20-Nov-18 05:44 PM hi @m̺̻̪̞͚̪͖o̖͛ͧͪ͆̚õ̱͓ͯ͌ͫo͂ͣ̉ͤ͗̎n̗ ! 20-Nov-18 05:45 PM hey qualia, i'm sayaendopeace from twitter 20-Nov-18 05:46 PM oh rad, hi! 20-Nov-18 05:46 PM I don't know what you all are talking about needing some cryo stuff to make a cloud chamber. I walk outside my shop and I'm in a cloud chamber! 20-Nov-18 05:46 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181120_025512-401FA.jpg 20-Nov-18 05:46 PM https://www.spscientific.com/Products/Thermal_Products/FTS_Systems/Air_Stream/XR_AirJet_Sample_Coolers/ -- it was one of these, but a much older version, i think. NMR/EPR/x-ray diffraction sample chiller, i guess :D 20-Nov-18 05:46 PM Pump down times right now though... 20-Nov-18 05:47 PM snrk 20-Nov-18 05:57 PM Ahh, that is one of those comoressed air separators wich gives out hot air in one end and cold air in the other? 20-Nov-18 05:57 PM /vortex tubes/ 20-Nov-18 06:16 PM I don't think so, I think it's just a semi-sealed compressor like a refridgerator would use 20-Nov-18 06:16 PM i sorta wish i had the tools to safely disassemble and reassemble it, 'cos the huge cylindrical metal business end of the thing is at the end of 20ft of 3" diameter insulated mesh tubing. it's very heavy and awkward 20-Nov-18 06:18 PM But says "mechanically refrigerated" 20-Nov-18 06:18 PM has considered taking an hvac repair & licensing course just to be able to legally work on this thing 20-Nov-18 06:18 PM /you should/ 20-Nov-18 06:18 PM At least here in spain, I wouldn't need to do it "legally", as long as you don't do it for money, it's fine (and you are not dismantling hundreds of devices 20-Nov-18 06:20 PM I can definitely evacuate the hell out of an hvac system as-is, I'm just not exactly sure how one goes about doing coolant recovery and replacement 20-Nov-18 06:20 PM nod, California is pretty strict about emissions around this kind of thing 20-Nov-18 06:20 PM if you go to a store to buy a canister of vehicle-AC recharge coolant, there's like a $20 deposit to get you to return whatever you don't use and it's covered in 'IT IS ILLEGAL TO DISCHARGE THIS INTO THE ATMOSPHERE' warnings 20-Nov-18 06:22 PM Interesting. 20-Nov-18 06:22 PM I remember seeing lots of threads in computer modding forums about custom cold heads for this kind of refrigeration. Damn, the building worm bites again... 20-Nov-18 06:22 PM I hate-love you. XD 20-Nov-18 06:23 PM :D 20-Nov-18 06:23 PM that's what I'm here for 20-Nov-18 06:28 PM You're a precious Vacuum Succubus, my dear. 20-Nov-18 06:30 PM sings the siren song of well-used secondhand turbopump bearing whine 20-Nov-18 06:33 PM ties himself to his mill with a corrugated KF16 tube to resist further temptation 20-Nov-18 06:37 PM ok, it's time to go home and do some leak hunting or somethin' 20-Nov-18 06:37 PM go, go, go! 20-Nov-18 08:08 PM What's everyone up to? 20-Nov-18 08:09 PM Cleaning up my shop/building new benches and exploring some beam alignment mechanics. 20-Nov-18 08:10 PM Also @qualia you'd want a vacuum chamber for that, unfortunately. And a pretty big one. Not many repair shops equipped for that kind of work afaik. 20-Nov-18 08:10 PM Fun fun 20-Nov-18 08:10 PM Im thinking I'll build some simple benches when I burn up my excess vacation days during Christmas 20-Nov-18 08:11 PM Im actually taking down my original bench to replace with another one of my Intel benches, and then building a new stand for my cnc 20-Nov-18 08:11 PM Well I actualy have to build the cnc stand first but details... 20-Nov-18 08:12 PM Intel benches? I didn't know Intel made benches 20-Nov-18 08:13 PM They came from an intel r&d site 20-Nov-18 08:13 PM Oooooh 20-Nov-18 08:13 PM Lucky 20-Nov-18 08:13 PM Where do you guys find this shit 20-Nov-18 08:13 PM Like half of my shop infrastructure is intel stuff 20-Nov-18 08:14 PM I'm planning to build the benches myself from wood from home Depot because I don't think anyone else can quite get what I'm looking for 20-Nov-18 08:14 PM Oh hey @iximeow ! 20-Nov-18 08:14 PM i've seen some surprisingly interesting electronics pop up on craigslist of all places in the last few months 20-Nov-18 08:14 PM hi! 20-Nov-18 08:15 PM Hmm, I should spend some time trolling Craigslist, I'd be amazed if there wasn't weird low-cost electronics in Boston 20-Nov-18 08:15 PM Oh! My partner, Mattie, pointed out that there are storage unit auctions in Boston! So, hell, maybe i could find some cool stuff at those? 20-Nov-18 08:15 PM Idk, on one hand I want a lot of cool lab equipment and on the other hand I know I have neither the space nor the money to afford the space for it all 20-Nov-18 08:17 PM Seattle Craigslist is pretty great. Its how I found out about the intel stuff 20-Nov-18 08:17 PM these are my limiting factors for many things as well 20-Nov-18 08:18 PM Wish space in Boston wasn't so damn expensive or that, alternatively, my basement was insulated 20-Nov-18 08:18 PM @AdamMcCombs is most of it free to good home? 20-Nov-18 08:18 PM It was pretty cheap 20-Nov-18 08:18 PM it took a few day to de install... 20-Nov-18 08:19 PM Ah 20-Nov-18 08:19 PM All this was mine for ~100$ 20-Nov-18 08:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/5s6pHAvMIIbnBDg3_04X1xS6I8cipME0OlQCHuXwFa-3B877.png 20-Nov-18 08:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/8gDY3MhmO8QIwNgKutuJUWH_apMkQNAMoUhtU2vmlb-BB01A.png 20-Nov-18 08:20 PM niiiiice 20-Nov-18 08:21 PM I also got to go to some other cool rooms in the building... 20-Nov-18 08:21 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/e3DwuCgyxnAcUlhYJ9MPa1F-MYaVu0cT-57d-IDehy-E4833.png 20-Nov-18 08:26 PM Dude what the hell 20-Nov-18 08:26 PM Lucky 20-Nov-18 08:26 PM Trying to sleep unsuccessfully here... 20-Nov-18 08:26 PM That looks so cool 20-Nov-18 08:26 PM @Zhang what time zone are you in? 20-Nov-18 08:27 PM Uk 20-Nov-18 08:27 PM Oh yeah then it's late there. Go to bed! 20-Nov-18 08:27 PM And Adam is definitely cool. I love the stuff you share on twitter. It's is inspiring. 20-Nov-18 08:28 PM I think at this point it is early... 20-Nov-18 08:29 PM Yeah, it is early. 20-Nov-18 08:29 PM Also thanks, im glad that other people are interested in the stuff I am 20-Nov-18 08:30 PM I feel you, @Zhang Spain here. 20-Nov-18 08:30 PM Snoring dogs are, too. XD 20-Nov-18 08:30 PM Any more super cool photos, @AdamMcCombs ? 20-Nov-18 08:30 PM (and BTW, everyone in here will be interested in the stuff you are) 20-Nov-18 08:33 PM You just want me to find random cool photos? 20-Nov-18 08:33 PM oh ok i was confused b/c i got a ping about it being later here and was going to say that no im in east coast US 20-Nov-18 08:33 PM its only 23:30 here, plenty of night/morning left 20-Nov-18 08:34 PM That's fine, but I was thinking more on the line of the Shelves day. 20-Nov-18 08:34 PM Ah ok 20-Nov-18 08:34 PM I can do that 20-Nov-18 08:34 PM wish i had cool lab photos... 20-Nov-18 08:34 PM Yeah, I mismatched you and Zang, but corrected it before you saw it. Sorry for that. ^^U 20-Nov-18 08:34 PM but all cybersecurity photos are is computers, and not even old computers 20-Nov-18 08:34 PM you're fine! 20-Nov-18 08:35 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/3xFsQDNDzmkdYa0ql2kW-z5klBLkWbMEBkYCzdRGrm-E6191.png 20-Nov-18 08:35 PM :I aw lucky 20-Nov-18 08:35 PM It would have been a cool building to work in... 20-Nov-18 08:35 PM seriously 20-Nov-18 08:35 PM Arm64 for teh win... not that package photos are interesting. 20-Nov-18 08:35 PM what did they do with it after equipment was removed? 20-Nov-18 08:36 PM It was a massive facility 20-Nov-18 08:36 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/3xFsQDNDzmkdYa0ql2kW-z5klBLkWbMEBkYCzdRGrm-37DDD.png 20-Nov-18 08:36 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/GTek4D07CST-X0qo_5FaC0_ms2TeYJtAqe5LrZzqBn-4F331.png 20-Nov-18 08:36 PM Looks hugw. 20-Nov-18 08:36 PM Intel cleanrooms tend to be huge, yeah 20-Nov-18 08:36 PM They never finished the entire building either 20-Nov-18 08:36 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/mWVRejblUoG_qWl5246AB2f9Yv5zqJiYB4Q0LLaad9-1A0DF.png 20-Nov-18 08:36 PM The coms rooms were a mess 20-Nov-18 08:36 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Wx89QaAwlKsjZ0jq814SBpiWFHIauyVFp58MWDpRaV-21CD2.png 20-Nov-18 08:38 PM pffft 20-Nov-18 08:38 PM But also... 20-Nov-18 08:38 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/MBhFPyyAwOVwqDP9vFgeX5WtiYrVboONOTZTWkAuHr-58D54.png 20-Nov-18 08:38 PM so, wait, if im on craigslist boston 20-Nov-18 08:38 PM where should i look? 20-Nov-18 08:38 PM for sale? 20-Nov-18 08:39 PM The fire alarm went off while I was there as well... https://photos.app.goo.gl/oJiktbK5gvB91g6d8 20-Nov-18 08:39 PM did someone come to turn it off @AdamMcCombs ? 20-Nov-18 08:39 PM So funny story about that 20-Nov-18 08:39 PM .... uh, does anyone wanna drop 15k on getting into long-road trucking? 20-Nov-18 08:39 PM https://boston.craigslist.org/gbs/hvo/d/good-interior-peterbilt-379/6751724907.html 20-Nov-18 08:39 PM I like facilities stuff 20-Nov-18 08:39 PM I think its interesting. And I pay attention to it 20-Nov-18 08:39 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/zfM1qobHg-oIGB5klyj8plHyijtTirRDjceG_BW5hU-C93B8.png 20-Nov-18 08:39 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/yS6cE7kW5o8Wzy07Xwcsu8n0YSCKgaI2Zd99dTMw0K-79AD8.png 20-Nov-18 08:39 PM So when I was touring the building I found its ops docs 20-Nov-18 08:40 PM ooh neat 20-Nov-18 08:40 PM A nice find 20-Nov-18 08:41 PM So when the alarm when off and all of the auction people were freaking out... 20-Nov-18 08:41 PM I went and found the volume on the fire alarm system 20-Nov-18 08:41 PM ... i like where you're going with this 20-Nov-18 08:41 PM ... dude https://boston.craigslist.org/sob/ele/d/rare-vintage-olivetti-lettera/6750918324.html 20-Nov-18 08:41 PM craigslist is /wild/ 20-Nov-18 08:42 PM So I found the alarm control room right as the fire department was showing up 20-Nov-18 08:42 PM Turns out some kid had hit a pull station 20-Nov-18 08:42 PM Yeah craigslist is great 20-Nov-18 08:45 PM DUDE 20-Nov-18 08:45 PM https://boston.craigslist.org/bmw/ele/d/kenwood-ts-570sg/6754105118.html 20-Nov-18 08:45 PM Welp there goes hedgeberg 20-Nov-18 08:45 PM bookmarks 20-Nov-18 08:45 PM this was not an ok thing to recommend to me 20-Nov-18 08:46 PM come to socal, we have ... 20-Nov-18 08:46 PM https://losangeles.craigslist.org/lgb/ele/d/lamp/6752181986.html 20-Nov-18 08:46 PM "Lamp" 20-Nov-18 08:46 PM where you able to pick something up from those book shelves? 20-Nov-18 08:46 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/moth_1538209651-5CCD7.png 20-Nov-18 08:46 PM @iximeow 20-Nov-18 08:46 PM someone mention lamps? 20-Nov-18 08:47 PM lol 20-Nov-18 08:47 PM anyway @AdamMcCombs how are you getting all this stuff moved around? 20-Nov-18 08:47 PM At least I'm safe from craigslist because I'm in EU... XDDD 20-Nov-18 08:47 PM Well... 20-Nov-18 08:47 PM It does exist over there... 20-Nov-18 08:48 PM Yeah, Craigslist here seems pretty tame by comparison. 20-Nov-18 08:48 PM i love how i still cant afford most of those 20-Nov-18 08:48 PM yo wait seriously? https://boston.craigslist.org/gbs/ele/d/flashforge-creator-pro-3d/6734028908.html 20-Nov-18 08:49 PM @AdamMcCombs those photos of that empty Intel plant looks like the basement of the building I am sitting in atm lol 20-Nov-18 08:49 PM pffft they want $400 /or/ a nice set of milwaukee tools 20-Nov-18 08:49 PM they used to assemble MCMs down there 20-Nov-18 08:49 PM lol 20-Nov-18 08:49 PM just empty clean room now... well dirty room now I guess 20-Nov-18 08:49 PM @Conmega where at? 20-Nov-18 08:49 PM ibm? 20-Nov-18 08:49 PM IBM Poughkeepsie Bldg. 012 20-Nov-18 08:49 PM the building with the clock tower on it 20-Nov-18 08:50 PM oh neat 20-Nov-18 08:50 PM the second floor is the test floor 20-Nov-18 08:50 PM where we bringup new mainframe hardware 20-Nov-18 08:50 PM could you ever guess what I'm doing here :P 20-Nov-18 08:50 PM Never... 20-Nov-18 08:50 PM no, not really, I honestly don't know 20-Nov-18 08:50 PM I actually have no idea what IBM does anymore 20-Nov-18 08:50 PM I know that they used to have fabs before global gobbled them up 20-Nov-18 08:50 PM and I know they own the linux kernel dev team by proxy now 20-Nov-18 08:50 PM but past that I got nothing 20-Nov-18 08:51 PM global gobbled them up 20-Nov-18 08:51 PM LOL 20-Nov-18 08:51 PM we payed them to take our stuff... litterally 20-Nov-18 08:51 PM pffft 20-Nov-18 08:51 PM seriously? 20-Nov-18 08:52 PM because we didn't want to deal with the expense of running the plant anymore 20-Nov-18 08:52 PM I thought they bought it all 20-Nov-18 08:52 PM it was losing us money 20-Nov-18 08:52 PM thats hilarious 20-Nov-18 08:52 PM good thing we did too because now they are saying they can't even do 7nm 20-Nov-18 08:52 PM first process i ever designed in was IBM9...k? 20-Nov-18 08:52 PM remember AMD bailed ship from them 20-Nov-18 08:52 PM but yea, weird shit deals and stuff 20-Nov-18 08:52 PM I don't remember what the last digit was, been too long 20-Nov-18 08:52 PM we payed GF like billions I think lol 20-Nov-18 08:52 PM but yeah, that's wild 20-Nov-18 08:53 PM it was weird 20-Nov-18 08:53 PM https://orangecounty.craigslist.org/ele/d/lecroy-lsa1000-1ghz-ethernet/6707717659.html heck. this guy's been trying to sell this for about 6 months now 20-Nov-18 08:53 PM but that included them doing our next two chip runs 20-Nov-18 08:53 PM Funny thing about IBM SEMs and TEMS 20-Nov-18 08:53 PM for the next two projects 20-Nov-18 08:53 PM so it was a weird thing 20-Nov-18 08:53 PM @iximeow wait seriously 20-Nov-18 08:53 PM They all have twice as many fuses as the manufacture puts in them 20-Nov-18 08:54 PM @hedgeberg yeah i was hoping it would sell before i saw it again and was tempted. alas 20-Nov-18 08:54 PM how much??? 20-Nov-18 08:54 PM Also to remove a SF6 filled instrument from IBM you are suposed to recover the SF6 down to vacuum, then backfill with N2 20-Nov-18 08:54 PM You can't just recover sf6 down to atmosphere 20-Nov-18 08:55 PM Lecroy LSA1000 1Ghz Ethernet Digital Oscilloscope 2 Chan - $699 (Irvine) 20-Nov-18 08:55 PM oh I didnt see the pricestamp 20-Nov-18 08:55 PM thats... really pretty good for a lecroy... 20-Nov-18 08:55 PM ...what are these? https://boston.craigslist.org/gbs/ele/d/toa-input-modules/6748433184.html 20-Nov-18 08:56 PM some audio crap 20-Nov-18 08:56 PM Building AV stuff 20-Nov-18 08:56 PM that makes sense 20-Nov-18 08:56 PM That's what I did in high school... 20-Nov-18 08:57 PM yeah thats a shockingly common tech origin story 20-Nov-18 08:57 PM doing professional AV stuff as a high schooler 20-Nov-18 08:57 PM would this be cheap enough to make up for the cost of a blue laser diode? https://boston.craigslist.org/nos/ele/d/blue-laser-new/6739692930.html 20-Nov-18 08:57 PM I don't think so, right? 20-Nov-18 09:00 PM time to be productive and not spend all night windowshopping ebay 20-Nov-18 09:02 PM UH 20-Nov-18 09:02 PM https://boston.craigslist.org/gbs/ele/d/national-instruments-pci/6745252490.html 20-Nov-18 09:02 PM hey someone is selling NI PCI DAQ units 20-Nov-18 09:02 PM I am extremely tempted ngl 20-Nov-18 09:02 PM what the hell im suddenly finding a ton of good stuff 20-Nov-18 09:02 PM here we go, @AdamMcCombs familiar with this brand? 20-Nov-18 09:02 PM https://boston.craigslist.org/gbs/ele/d/dc-lab-pump-qvg50/6744966095.html 20-Nov-18 09:05 PM No if im doing anything critical with water is probably water chilling and then probably a water chiller. 20-Nov-18 09:05 PM fair enough 20-Nov-18 09:05 PM And then probably a haskris chiller 20-Nov-18 09:06 PM does anyone need any pentode tubes? someone is selling a set of 4 KT88's, which i think are meant for audio but idk for sure and i figured id ask 20-Nov-18 09:08 PM Hedgeberg stahp. XDDDDDD 20-Nov-18 09:08 PM Some of us are relatively poor. 20-Nov-18 09:08 PM dude i literally cant afford 90% of this stuff 20-Nov-18 09:08 PM but, hey, who knows, someone may be able to? 20-Nov-18 09:12 PM True. Especialy don't look for curve tracers, that would make me cry, manly tears, but whatever. XDDD 20-Nov-18 09:12 PM (Or wire bonders) 20-Nov-18 09:15 PM up to 500 MHz too 20-Nov-18 09:15 PM ?? 20-Nov-18 09:15 PM oh did you delete the message because I swore? 20-Nov-18 09:15 PM yeah, that tracks, sorry 20-Nov-18 09:16 PM No problem 20-Nov-18 09:18 PM ...why is there so much NI DAQ stuff for sale here? 20-Nov-18 09:18 PM is that normal? 20-Nov-18 09:28 PM @hedgeberg hi i'm home now -- vacuum chamber for what, now? hvac repair? 20-Nov-18 09:29 PM for ensuring no leaks 20-Nov-18 09:29 PM at least iirc 20-Nov-18 09:29 PM (for hvac, yeah) 20-Nov-18 09:29 PM like, the way people do HVAC system recharges is with vacuum pumps & manifolds designed for that sort of work. they do not put the entire system in a vacuum chamber afaik 20-Nov-18 09:29 PM the only reason i have a vacuum pump rn is because 3 CFM two-stage rotary vane pumps can be had at horror freight tools for $150 a pop 20-Nov-18 09:30 PM ?? fair enough, tbh prolly assume im wrong 20-Nov-18 09:30 PM dunno why i thought that, feels like i had a reason, but w/e 20-Nov-18 09:30 PM tbh I wish there was a horror freight near here 20-Nov-18 09:31 PM it's like, in the same way you fill a compressor with a working fluid, you can also take it out through there too. is my understanding, anyways 20-Nov-18 09:31 PM Besides, SAE connectors are pure shit, seriously. 20-Nov-18 09:32 PM yeah they're uh. idk if i would say 'great' but they do have cheap gloves and polycarbonate safety glasses and magnet trays 20-Nov-18 09:32 PM and they are not even HVAC, they do like 200 microns. 20-Nov-18 09:32 PM everything else is exceedingly suspect 20-Nov-18 09:32 PM dude https://boston.craigslist.org/sob/ele/d/like-new-in-box-pioneer-dj/6750009039.html uuuugh maybe i should get out of tech and back into djing :I 20-Nov-18 09:32 PM i remember wanting one of these years and years and years ago 20-Nov-18 09:34 PM you can get an actually brand new probably really similar version for about that much 20-Nov-18 09:34 PM yeah just checked on ebay 20-Nov-18 09:34 PM they're way overcharging 20-Nov-18 09:35 PM i wish my octatrack's synthesis primitives weren't so cold and thin 20-Nov-18 09:35 PM A lot of people on craigslist are selling dji phantom pro drones? 20-Nov-18 09:35 PM if anyone wants one i guess lmk and I can try bartering? 20-Nov-18 09:35 PM especially now that i've had it for like three years and i'm extremely fluent in its very annoyingly specific workflow 20-Nov-18 09:35 PM i want a sodium iodide PMT-coupled scintillator that isn't leaking thalliated iodine slime everywhere 20-Nov-18 09:35 PM lmk if u see one 20-Nov-18 09:36 PM no dice, but did just find: https://boston.craigslist.org/bmw/ele/d/p-8005a-pulse-generator/6752660869.html 20-Nov-18 09:36 PM that is remarkably nice for a $75 20-Nov-18 09:37 PM bonus points if it's wired for 900V or so so i can open palm slam that shit on my ludlum 3 and go uranium prospecting with the gals 20-Nov-18 09:37 PM ooh 20-Nov-18 09:37 PM are you like right by MIT 20-Nov-18 09:37 PM is that the thing 20-Nov-18 09:37 PM yup 20-Nov-18 09:37 PM I actually technically work for MIT 20-Nov-18 09:37 PM technically 20-Nov-18 09:37 PM its weird 20-Nov-18 09:38 PM I'm not super far from Boston myself. Being in Pok NY... just a half a day's drive :) 20-Nov-18 09:38 PM oh neat 20-Nov-18 09:38 PM i almost ended up working out that way 20-Nov-18 09:38 PM you should have, boston is great this time of year 20-Nov-18 09:38 PM doing hardware RE for some microfluidics folx 20-Nov-18 09:38 PM is it really or was that sarcasm 20-Nov-18 09:38 PM i grew up in western new york ok 20-Nov-18 09:38 PM no i was dead serious I love the cold 20-Nov-18 09:39 PM oh ok cool 20-Nov-18 09:39 PM i miss snow.... 20-Nov-18 09:39 PM yeah I can't understand living somewhere where theres no snow 20-Nov-18 09:39 PM i would've considered it more seriously if i didn't have gestures vaguely responsibilities 20-Nov-18 09:40 PM fortunately MIT provides good pay and benefits for the work I do, so I was able to satisfy the responsibilities easily enough 20-Nov-18 09:40 PM oh you know what 20-Nov-18 09:40 PM hm, afaict there are only two seasons. forever summer and california 20-Nov-18 09:40 PM I bet they'd have a lot of great stuff over at the tech flea market 20-Nov-18 09:40 PM I should go to that, if anyone has anything they'd want me to look for there they have a ton of weird stuff there from what I've heard 20-Nov-18 09:40 PM @iximeow sounds boring 20-Nov-18 09:41 PM it is. a half inch of rain really is an exciting day 20-Nov-18 09:42 PM uhhhh 20-Nov-18 09:42 PM https://boston.craigslist.org/gbs/ele/d/scanner-uniden-bearcat-hand/6747142412.html 20-Nov-18 09:42 PM Huh 20-Nov-18 09:42 PM Hey, I went to live in a place where supposedly doesn't rain a lot, and it's been raining a week now. 20-Nov-18 09:42 PM Gf says it rains since I came. 20-Nov-18 09:42 PM wonder if this could be junked any nice parts 20-Nov-18 09:42 PM (to live here) 20-Nov-18 09:42 PM hedgeberg, any luck with wire bonders? 20-Nov-18 09:43 PM nope sorry 20-Nov-18 09:43 PM but there are some nice dlp projectors if anyone wants to hack up a DLP lithography kit 20-Nov-18 09:44 PM I have been looking for a decent DLP projector for litho 20-Nov-18 09:44 PM I'm in the middle of a repurposed CRT as e-beam, no thanks 20-Nov-18 09:44 PM though e-beam does sound lovely 20-Nov-18 09:45 PM i fucking love tech flea markets 20-Nov-18 09:45 PM @Conmega how's this for a start? 20-Nov-18 09:45 PM https://boston.craigslist.org/nos/ele/d/dell-dlp-front-projector/6743038923.html 20-Nov-18 09:45 PM DLP will be more reasonable in a short time 20-Nov-18 09:45 PM @Conmega don't take me too seriously, it is you who will get a SEM. 20-Nov-18 09:45 PM i picked up a 30kv 1mA spellman power supply from the 70s in perfect working order for $40 from the local ham swap meet and i'm like. this is the most frugal fucking smart shopper shit i have ever pulled off 20-Nov-18 09:45 PM it came out of an ion implanter system 20-Nov-18 09:46 PM (LMAO, watching 1992 Hackers movie...it's so terrible, I love it) 20-Nov-18 09:46 PM I'd own an SEM right now if I had the money and time 20-Nov-18 09:47 PM same but also space 20-Nov-18 09:47 PM Mx, beware... XD 20-Nov-18 09:47 PM been doing overtime for work and just yea blugh 20-Nov-18 09:47 PM (or behave) 20-Nov-18 09:47 PM space isn't an issue, I just need to clean up the damn basement 20-Nov-18 09:47 PM if I got rid of two smart cars then I'd have more than enough space :P 20-Nov-18 09:47 PM ... 20-Nov-18 09:47 PM 2? 20-Nov-18 09:47 PM i will neither beware nor behave 20-Nov-18 09:47 PM one I got for 50 bucks 20-Nov-18 09:47 PM so 20-Nov-18 09:47 PM theres that 20-Nov-18 09:48 PM yeah 20-Nov-18 09:48 PM wow ok 20-Nov-18 09:48 PM my old boss had two smart cars 20-Nov-18 09:48 PM one gas, one electric 20-Nov-18 09:48 PM the other needed work but not the work I expected... it needs a lot more than I expected... 20-Nov-18 09:48 PM thought it was a fuel pump... oh was I wrong 20-Nov-18 09:48 PM i drove one of them once and it felt very unsafe and like it had a massive wind profile 20-Nov-18 09:48 PM head gasket, shouldn't have been suprised really 20-Nov-18 09:48 PM i did not care for it 20-Nov-18 09:48 PM uh oh 20-Nov-18 09:48 PM but even then, the price I got it for was reasonable enough 20-Nov-18 09:48 PM if I rebuilt it I could still easily profit 20-Nov-18 09:48 PM but time... blugh 20-Nov-18 09:50 PM YO 20-Nov-18 09:50 PM learning to appropriately value my time so that i don't let tons of fuckoff never-actually-gonna-do-this hobbies pile up and crush me was/is .. important 20-Nov-18 09:50 PM https://boston.craigslist.org/gbs/ele/d/bk-st-140-power-amplifier/6742066874.html 20-Nov-18 09:50 PM oh wait no 20-Nov-18 09:50 PM this is purely audio range 20-Nov-18 09:51 PM here's a black metal box full of gain 20-Nov-18 09:51 PM yeaaa... 20-Nov-18 09:51 PM i appreciate the design aesthetic 20-Nov-18 09:51 PM "Power amp" way to waste my time 20-Nov-18 09:51 PM (language) 20-Nov-18 09:51 PM but yeah feel that 20-Nov-18 09:51 PM i've considered building a 13.56 MHz power amp 20-Nov-18 09:52 PM you can do it with discrete transistors if you're so motivated 20-Nov-18 09:52 PM its not terribly difficult 20-Nov-18 09:52 PM I fixed it... but sure saw nothing in the rules about language specifically, just SFW but personally there is plenty of cussing where I work... 20-Nov-18 09:52 PM i wouldn't need a lot of power, i think; maybe a couple dozen watts 20-Nov-18 09:53 PM Yeah fair 20-Nov-18 09:53 PM yeah same, my boss and I swear up a storm, but its still best to be careful 20-Nov-18 09:53 PM @Conmega everyone swears a lot, but adam has been quite strict. 20-Nov-18 09:53 PM There he goes. 20-Nov-18 09:53 PM XD 20-Nov-18 09:53 PM yeah 13.56 MHz is an easy goal to achieve @qualia 20-Nov-18 09:53 PM right the rules did not say "Family Friendly" he is correcting it 20-Nov-18 09:54 PM and transistor-level design is real fun 20-Nov-18 09:54 PM I followed the rules as it is generally enforced by other servers when stating JUST SFW language is ussually specified by family friendly language 20-Nov-18 09:54 PM So, again, apologies for the mistake. Adam is updating the rules to be more clear. 20-Nov-18 09:54 PM uh, I just found a hospital bed? 20-Nov-18 09:55 PM >.> 20-Nov-18 09:55 PM @hedgeberg i have terrible urges to build nontrivial design from 7400-series chips now and then 20-Nov-18 09:55 PM yeah why not? 20-Nov-18 09:55 PM Idea is that anyone, including young students, can take part in this server 20-Nov-18 09:55 PM 7400-series are fine 20-Nov-18 09:55 PM price and space 20-Nov-18 09:55 PM (in that i'd be looking at hundreds of chips + wires + ... and... space) 20-Nov-18 09:56 PM that was how i did my first amplifier design/ring oscillator in my horrible second analog design course 20-Nov-18 09:56 PM Ok, then family friendly is the descriptor in most other discord server's descriptions, since "young students" would be children, and children are a part of a family, and keeping language to that standard is "family friendly". 20-Nov-18 09:56 PM (hated that class, professor was an absolute jerk and tried to fight me during lecture) 20-Nov-18 09:56 PM (he actually called me stupid for pointing out that lab instructions were exteremely unclear) 20-Nov-18 09:57 PM I generally see SFW used to describe image ruling... Not so much text ruling. 20-Nov-18 09:57 PM I know servers that the entire concept is not family friendly, but there are SFW channels for discussion purposes. Then NSFW channels for images. 20-Nov-18 09:57 PM As the rules stand, they are confusing in my mind. I'm not trying to excuse my mistake or action. But just want to help prevent similar mistakes in the future is all. 20-Nov-18 09:57 PM 2. Keep it SFW and family friendly. We want this to be a place that anyone and everyone can be a part of. Some folks might be slacking offhanging out while at work. Younger engineers may be present. Be mindful of what you post and take the lewds/foul language elsewhere. 20-Nov-18 09:57 PM makes a clearer picture in my mind 20-Nov-18 10:00 PM oooh hello this is cool 20-Nov-18 10:00 PM https://boston.craigslist.org/nwb/ele/d/ham-radio-icom-ex-627-antenna/6731234407.html 20-Nov-18 10:01 PM oh neat 20-Nov-18 10:01 PM its been up for 28 days too, wonder fi i could lowball them 20-Nov-18 10:01 PM aw man poor guy is selling a ton of stuff afaict 20-Nov-18 10:01 PM looks like theyre moving 20-Nov-18 10:01 PM but check this out!!! 20-Nov-18 10:01 PM https://boston.craigslist.org/nwb/ele/d/ham-radio-military-rec/6731236388.html 20-Nov-18 10:02 PM I know some people who collect military equipment, mostly radio... 20-Nov-18 10:02 PM Since a few of those people also collect computers 20-Nov-18 10:02 PM and well that's my hobby 20-Nov-18 10:06 PM ooh hey another cool one 20-Nov-18 10:06 PM https://boston.craigslist.org/gbs/ele/d/hallicrafters-sx-42-receiver/6731808876.html 20-Nov-18 10:06 PM and a vacuum tube tester? 20-Nov-18 10:06 PM does anyone need a tube tester? 20-Nov-18 10:06 PM oh my god 20-Nov-18 10:06 PM https://boston.craigslist.org/nos/ele/d/lot-of-telecom-equipment-sage/6744695490.html @iximeow @qualia uhhhhh does... does anyone want to help me buy this and then split the rewards??? 20-Nov-18 10:06 PM they're super overcharging but like 20-Nov-18 10:06 PM if they could be talked down that is an amazing haul 20-Nov-18 10:11 PM i legitimately do not know what any of those things are useful for 20-Nov-18 10:11 PM its all relatively modern telecomm test equipment 20-Nov-18 10:11 PM the real haul there is the tektronix handheld oscope 20-Nov-18 10:11 PM but those SAO units are for TV test signals 20-Nov-18 10:12 PM woaaaaaah that is an oscope! that's wild 20-Nov-18 10:13 PM i do not speak telecom at all 20-Nov-18 10:13 PM a tube tester, tho, ... 20-Nov-18 10:13 PM i've thought about making my own vacuum tubes 20-Nov-18 10:13 PM bc why not 20-Nov-18 10:15 PM for sure 20-Nov-18 10:15 PM ive been thinking about learning glasblowing for the same reason 20-Nov-18 10:15 PM oh, hey, someone is selling a lulzbot mini 20-Nov-18 10:15 PM a lot of mixers too 20-Nov-18 10:15 PM this listing is just "oscilloscope" 20-Nov-18 10:15 PM oh uh ok guys has anyone been looking for oscilloscopes 20-Nov-18 10:15 PM becasuse i just found a ton 20-Nov-18 10:15 PM pffft, this one is running win95 and takes a floppy disk 20-Nov-18 10:15 PM https://boston.craigslist.org/bmw/ele/d/tektronix-tds7104-1ghz-10gs/6735282497.html 20-Nov-18 10:21 PM aa 20-Nov-18 10:21 PM grabbypaws ;.; 20-Nov-18 10:21 PM i wannit.. 20-Nov-18 10:21 PM $1800 20-Nov-18 10:22 PM nghggghgnghn 20-Nov-18 10:22 PM if you want I can buy it and ship to you 20-Nov-18 10:22 PM 1 GHz bandwidth 20-Nov-18 10:22 PM IT RUNS WINDOWS 2000 20-Nov-18 10:22 PM omg omg 20-Nov-18 10:22 PM WAIT 20-Nov-18 10:22 PM Oh my god 20-Nov-18 10:22 PM i'm gonna play half life deathmatch on it 20-Nov-18 10:22 PM In the unlikely event that you ever have a problem with the scope, please contact me for repair services. I specialize in repairing TDS500, 600, 700, and TDS7000 series (up to and including 1GHz) scopes which are failing SPC (Signal path compensation) as well as various problems commonly found on Agilent 545XX and 548XX series of scopes. 20-Nov-18 10:22 PM what a fun life that must be... 20-Nov-18 10:22 PM this is my new gaming rig 20-Nov-18 10:22 PM lmao 20-Nov-18 10:23 PM program it to use the ADCs as joystick inputs 20-Nov-18 10:23 PM oh ok he lives near woonsocket 20-Nov-18 10:23 PM this seems like a fun guy 20-Nov-18 10:23 PM (as i assume that anyone who lives near a town called woonsocket would be) 20-Nov-18 10:24 PM Joined the server. 20-Nov-18 10:25 PM Everyone, say hi Dyno 20-Nov-18 10:25 PM looks busy at work while typing in discord? 20-Nov-18 10:25 PM hi dyno 20-Nov-18 10:25 PM Dyno is the new bot 20-Nov-18 10:25 PM ...wait what on earth did i just find 20-Nov-18 10:25 PM https://boston.craigslist.org/nwb/ele/d/vintage-brass-telephone/6751695328.html 20-Nov-18 10:25 PM henlo dyno 20-Nov-18 10:25 PM this was made in 1973?? 20-Nov-18 10:26 PM it was vintage then 20-Nov-18 10:26 PM it looks like it was made in 1873 20-Nov-18 10:26 PM hi dyno you are a good bot 20-Nov-18 10:26 PM im assuming all of the 3 people who bought these in 1973 must have had remarkably weird taste 20-Nov-18 10:26 PM oh hey! cheap server racks from salem! 20-Nov-18 10:26 PM https://boston.craigslist.org/nwb/ele/d/rack-electric/6736654922.html 20-Nov-18 10:26 PM wonder if i can get them per-cursed! 20-Nov-18 10:26 PM **pre-cursed 20-Nov-18 10:28 PM oh are those square holes 20-Nov-18 10:28 PM free is cheap for racks lol 20-Nov-18 10:28 PM that looks like a nice little rack 20-Nov-18 10:28 PM i wish i could find free racks what the heck 20-Nov-18 10:28 PM $75 20-Nov-18 10:28 PM but yeah 20-Nov-18 10:28 PM i wanna swap all the server hardware on mine out to a smaller/not-literally-from-varian's-QA-lab/not-on-wheels rack 20-Nov-18 10:28 PM im going to contact them, this is a heck of a deal 20-Nov-18 10:28 PM so i can use that one for .. Science Machine 20-Nov-18 10:28 PM nim bin, oscilloscope, power supplies, etc, etc 20-Nov-18 10:30 PM !!!!!!!! 20-Nov-18 10:30 PM WAIT 20-Nov-18 10:30 PM WHAT 20-Nov-18 10:30 PM https://boston.craigslist.org/gbs/ele/d/karl-suss-photomask-aligner/6751552861.html 20-Nov-18 10:30 PM @AdamMcCombs hey uh, thoughts??? 20-Nov-18 10:30 PM ahhhhh so expensive but oh my god 20-Nov-18 10:30 PM https://boston.craigslist.org/gbs/ele/d/varian-mod-gen-ii-molecular/6751552145.html 20-Nov-18 10:31 PM oh my god 20-Nov-18 10:31 PM MBE systems are so sexy 20-Nov-18 10:31 PM right???? 20-Nov-18 10:32 PM i have no idea how they do what they do 20-Nov-18 10:32 PM maybe someday 20-Nov-18 10:32 PM it's like what eight sputter guns and a giant chamber full of poison and then you press some buttons and upload an mspaint png and you get gtx 1080 dies out right 20-Nov-18 10:33 PM surprisingly accurate 20-Nov-18 10:33 PM also they're awful to maintain afaik 20-Nov-18 10:33 PM when I was at Army Research Labs they had one they were using for growing uh 20-Nov-18 10:33 PM what was it 20-Nov-18 10:33 PM Hi 20-Nov-18 10:34 PM I think it was Tungsten Di-Selenide? 20-Nov-18 10:34 PM one of the precursors was /super/ toxic 20-Nov-18 10:34 PM so they had a small MBE system, and then they enclosed that inside of its own secondary airtight chamber 20-Nov-18 10:35 PM hi! 20-Nov-18 10:35 PM oh no 20-Nov-18 10:35 PM https://boston.craigslist.org/gbs/ele/d/bede-xray-diffractometer/6751434653.html 20-Nov-18 10:35 PM that sounds awful 20-Nov-18 10:35 PM oh no I could 20-Nov-18 10:35 PM I could take out a loan 20-Nov-18 10:35 PM I could actually take out a loan and afford this 20-Nov-18 10:35 PM somewhere on ebay there is or was an MBE system being sold for, uh. not a lot of money actually. included like several 42U racks of hardware 20-Nov-18 10:35 PM but uh 20-Nov-18 10:35 PM one of the sputter gun cooling lines sprayed a leak and soaked the entire inside of the chamber in what may or may not have been water 20-Nov-18 10:35 PM and this did not do kind things to anything inside that chamber 20-Nov-18 10:36 PM no no it would not have 20-Nov-18 10:36 PM hey, another rack: 20-Nov-18 10:36 PM https://boston.craigslist.org/gbs/ele/d/cooper-line-rack/6751488214.html 20-Nov-18 10:36 PM it looked like a magnesium fire went off on every surface of that chamber 20-Nov-18 10:36 PM meh, 2-post racks 20-Nov-18 10:36 PM yeah 20-Nov-18 10:36 PM not as nice 20-Nov-18 10:37 PM what the heck the x-ray diffractometer also runs windows 2000 20-Nov-18 10:37 PM LAN PARTY 20-Nov-18 10:37 PM god I kind of want it... 20-Nov-18 10:37 PM oh actually that's not that expensive huh 20-Nov-18 10:37 PM @AdamMcCombs is an xray diffractometer worth 8k? 20-Nov-18 10:37 PM can't you do x-ray diffractometry with a SEM 20-Nov-18 10:37 PM or am i thinking of something else 20-Nov-18 10:38 PM i dont know, i just know this is killing me 20-Nov-18 10:38 PM I mean i got a xrd for 5$ 20-Nov-18 10:38 PM but also yes 20-Nov-18 10:38 PM wait what 20-Nov-18 10:38 PM how dare you 20-Nov-18 10:38 PM 5... dollars? period? 20-Nov-18 10:38 PM what kind of thing would you use it for? 20-Nov-18 10:38 PM did you bring enough for the class 20-Nov-18 10:38 PM sintag unit with a Peltier detector and all the software/computer stuff 20-Nov-18 10:39 PM ...What the heck is up with the last few pages of craigslist here???? 20-Nov-18 10:39 PM https://boston.craigslist.org/nos/ele/d/solar-cells-3x6/6751450298.html 20-Nov-18 10:39 PM thats a stack of 100 cells? 20-Nov-18 10:39 PM for 10 dollars? 20-Nov-18 10:39 PM mean it cost like 3k to get it moved it's massive 20-Nov-18 10:40 PM "Welcome to Vacuum Hackers! Here's your SWAG BAG! five 1.33" conflat gaskets, a box of kimwipes, and an ownership title for an x-ray diffractometer in uzbekistan" 20-Nov-18 10:40 PM it's like, i bought an upright grand piano off of someone's lawn for $50 at one point 20-Nov-18 10:41 PM oh my god more things 20-Nov-18 10:41 PM really what i did there was paid them for the privilege of letting them not have to pay a disposal service 20-Nov-18 10:41 PM https://boston.craigslist.org/gbs/ele/d/zeiss-axiotron-inspection/6751436288.html 20-Nov-18 10:41 PM ok this is seriously legitimately tempting. 20-Nov-18 10:42 PM wasn't that the same picture as the other thing 20-Nov-18 10:42 PM yeah 20-Nov-18 10:42 PM same seller 20-Nov-18 10:42 PM could they really not take more than one picture 20-Nov-18 10:42 PM also like do you just have several grand to burn 'cos like 20-Nov-18 10:42 PM no, absolutely not 20-Nov-18 10:42 PM bats eyelashes cutely ~ 20-Nov-18 10:42 PM aw 20-Nov-18 10:42 PM i'd burn all of my savings and still need to take out a bit of a loan 20-Nov-18 10:42 PM I have only been working a proper job for about a year 20-Nov-18 10:42 PM most of my money since getting here has gone into starting-out costs 20-Nov-18 10:42 PM hhhhhhhhhh Im really really tempted on that microscope ugh 20-Nov-18 10:42 PM I'd call and ask for a payment plan or something 20-Nov-18 10:42 PM "views features down to .8 um" 20-Nov-18 10:42 PM my heart is going to give out 20-Nov-18 10:42 PM here's another cool thing but at this point im just sad 20-Nov-18 10:42 PM ???? 20-Nov-18 10:42 PM ????????? 20-Nov-18 10:42 PM OH 20-Nov-18 10:42 PM As sociates 20-Nov-18 10:45 PM Sorry in advanced @hedgeberg im testing stuff 20-Nov-18 10:46 PM yup there we go 20-Nov-18 10:46 PM ?mute @hedgeberg 20-Nov-18 10:46 PM the bot is getting a false positive on as-sociates 20-Nov-18 10:46 PM nope ok 20-Nov-18 10:46 PM ?mute hedgeberg 20-Nov-18 10:46 PM you need to specify a timelimit you goofus 20-Nov-18 10:46 PM @AdamMcCombs you need to @ me 20-Nov-18 10:46 PM also the bot swore 20-Nov-18 10:46 PM ?mute @hedgeberg 5s sshhh 20-Nov-18 10:46 PM My role isn't high enough to moderate this user. Move the Dyno role up above other roles. 20-Nov-18 10:47 PM HMM. 20-Nov-18 10:47 PM oh yeah the bot needs admin 20-Nov-18 10:47 PM oh yeah look @ that sh*tposting 20-Nov-18 10:47 PM ALSO WAIT 20-Nov-18 10:47 PM no poopposting 20-Nov-18 10:47 PM WHY AM I THE TEST DUMMY 20-Nov-18 10:47 PM ?mute @hedgeberg 20-Nov-18 10:47 PM https://boston.craigslist.org/gbs/ele/d/ag-as sociates-610-rtp-system/6751435818.html 20-Nov-18 10:47 PM thats the thing i kept trying to post 20-Nov-18 10:47 PM @AdamMcCombs 1 it needs a time spec 20-Nov-18 10:47 PM like "?mute @hedgeberg 1s" 20-Nov-18 10:48 PM ?mute @hedgeberg 10s sshhsshHHhH 20-Nov-18 10:48 PM hedgeberg#7337 was muted 20-Nov-18 10:48 PM oh cool 20-Nov-18 10:48 PM @qualia you can do electron (backscatter) diffraction with the right imaging rig in your SEM, maybe you mean that 20-Nov-18 10:48 PM that might be what i was thinking of, yeah 20-Nov-18 10:48 PM hedgebewg.. 20-Nov-18 10:48 PM can you talk now 20-Nov-18 10:49 PM Ok what do you need bse for? 20-Nov-18 10:49 PM ?mute @iximeow 10s can anyone mute anyone? 20-Nov-18 10:49 PM no only mods 20-Nov-18 10:49 PM ah that explains the nick colors 20-Nov-18 10:50 PM ?unmute 20-Nov-18 10:50 PM ?unmute @hedgeberg 20-Nov-18 10:50 PM hedgeberg#7337 was unmuted 20-Nov-18 10:50 PM welcome back 20-Nov-18 10:51 PM that's weird i thought 10s would be like 20-Nov-18 10:51 PM 10 seconds 20-Nov-18 10:51 PM yeah same here 20-Nov-18 10:51 PM i guess the minimum thing is minutes 20-Nov-18 10:51 PM finally 20-Nov-18 10:51 PM @hedgeberg SOWWY 20-Nov-18 10:51 PM i ask again why I was the test dummy 20-Nov-18 10:51 PM anyway, as long as someone has the "muted" role 20-Nov-18 10:51 PM they are muted 20-Nov-18 10:51 PM You were the first name i saw 20-Nov-18 10:51 PM that makes a sense 20-Nov-18 10:51 PM should be an easier way to test 20-Nov-18 10:52 PM ehehe 20-Nov-18 10:52 PM we were trying to test on other admins but that wasnt working 20-Nov-18 10:52 PM Test on me bro 20-Nov-18 10:52 PM \o/ 20-Nov-18 10:52 PM ....??? https://boston.craigslist.org/sob/ele/d/att-microcell-3-for-90/6751415322.html 20-Nov-18 10:52 PM LMAOOOOOOOOO 20-Nov-18 10:52 PM wait this is a thing that you can buy? 20-Nov-18 10:52 PM Are these LTE enabled? 20-Nov-18 10:52 PM no theyre 3g 20-Nov-18 10:52 PM that might be even better? 20-Nov-18 10:52 PM uh??? 20-Nov-18 10:53 PM eehh 20-Nov-18 10:53 PM I want a TEM, gimme your TEM pls 20-Nov-18 10:53 PM you can just buy a limesdr also, 20-Nov-18 10:54 PM no i know, i have one 20-Nov-18 10:54 PM unless you really need like legitimate phone service 20-Nov-18 10:54 PM I was thinking I could use the limesdr and these as a fun RF reversing excercise 20-Nov-18 10:54 PM uh 20-Nov-18 10:54 PM wait 20-Nov-18 10:55 PM ?mute @N00N 1 20-Nov-18 10:55 PM N00N#4283 was muted 20-Nov-18 10:55 PM what is this 20-Nov-18 10:55 PM https://boston.craigslist.org/nwb/ele/d/trimax-sm-4500-digital/6751398087.html 20-Nov-18 10:55 PM please look at the listing picture 20-Nov-18 10:55 PM one (1) minutes 20-Nov-18 10:55 PM ?unmute @N00N 20-Nov-18 10:55 PM N00N#4283 was unmuted 20-Nov-18 10:55 PM what 20-Nov-18 10:55 PM when you see it, i think you will also be a bit confused 20-Nov-18 10:55 PM oh it's also an mp4 player 20-Nov-18 10:56 PM U happy now, @N00N ? 20-Nov-18 10:56 PM remember when chinese manufacturers kept incrementing the number 20-Nov-18 10:56 PM mp3s weren't good enough and mp4 players were soooo 2008 so then mp5 players came along 20-Nov-18 10:56 PM XDDD 20-Nov-18 10:56 PM Didn't know that history 20-Nov-18 10:56 PM i do remember someone telling me they got an mp5 player 20-Nov-18 10:56 PM and i looked at them like they were a fool 20-Nov-18 10:56 PM anyway @qualia no no look at the listing picture, specifically the screen 20-Nov-18 10:57 PM @Nixie satisfied ️ 20-Nov-18 10:57 PM yeah that's why i brought that up 20-Nov-18 10:57 PM clearly it plays your pirated .avis 20-Nov-18 10:57 PM OH 20-Nov-18 10:57 PM huh 20-Nov-18 10:57 PM yeah, i guess 20-Nov-18 10:57 PM your pirated .avi...tars .... 20-Nov-18 10:57 PM i kinda want this? 20-Nov-18 10:57 PM Coffee time 20-Nov-18 10:58 PM @iximeow STOP 20-Nov-18 10:58 PM im pupset 20-Nov-18 10:58 PM :3 20-Nov-18 10:59 PM ...what is this??? 20-Nov-18 10:59 PM https://boston.craigslist.org/nos/ele/d/it-automation-controls/6751383668.html 20-Nov-18 10:59 PM the first one i mean 20-Nov-18 10:59 PM this guy looks like he has a ton of neat stuff 20-Nov-18 10:59 PM hedgeberg, let me know when you reach the end of internet. 20-Nov-18 11:00 PM no can do, I have several petabytes left to go 20-Nov-18 11:00 PM i have however reached the end of craigslist @Nixie 20-Nov-18 11:01 PM oh there's some neat stuff in there yeah 20-Nov-18 11:01 PM still need a benchtop dmm 20-Nov-18 11:02 PM same 20-Nov-18 11:02 PM i figure if im going to get one, I'll get a source-meter 20-Nov-18 11:02 PM ... searches backlog for whatever @GigaSquirrel suggested while i was at work 20-Nov-18 11:02 PM was ist 20-Nov-18 11:02 PM one that can do 4pp measurement 20-Nov-18 11:02 PM oh, a source meter is just a source + a meter 20-Nov-18 11:03 PM oh like a bench supply and a DMM in one? 20-Nov-18 11:03 PM so you can get quick impedance measurements, or a bunch of other things 20-Nov-18 11:03 PM oic 20-Nov-18 11:03 PM @qualia yeah but with a bunch of cool other things in there 20-Nov-18 11:03 PM actually reminds me i've been meaning to check the ESR of my Scary Capacitors 20-Nov-18 11:03 PM which is, i think, one of those kinds of things what needs a function generator and some other kind of thing 20-Nov-18 11:06 PM ?space 20-Nov-18 11:06 PM thats cool 20-Nov-18 11:07 PM really? 20-Nov-18 11:07 PM XD 20-Nov-18 11:10 PM so uh 20-Nov-18 11:10 PM there are a ton of GTX 1070/1080's for sale around here? 20-Nov-18 11:10 PM I think a bunch of bitcoin miners got burned and are trying to recoup investments? 20-Nov-18 11:11 PM yeaah 20-Nov-18 11:11 PM i can't wait until fault-tolerant disributed gpu runtime platforms become a thing so i can buy a crate of gtx1080s for a nickel and run single-particle GEANT4 collision events in just a month 20-Nov-18 11:13 PM at this rate? 20-Nov-18 11:13 PM give it 6 months and every bitcoin miner will be trying to liquidate their stuff 20-Nov-18 11:13 PM technically the GPUs are probably from ethereum folks 20-Nov-18 11:13 PM oh true 20-Nov-18 11:13 PM people haven't been mining btc on gpus for a long time now 20-Nov-18 11:14 PM although i did see someone selling one of those ANT Miner boxes 20-Nov-18 11:14 PM so it's very likely those cards have all been run absolutely ragged 20-Nov-18 11:14 PM yeah 20-Nov-18 11:14 PM i doubt they rigged up high-quality cooling 20-Nov-18 11:14 PM unless theyre new-in-box 20-Nov-18 11:14 PM ????? 20-Nov-18 11:14 PM https://boston.craigslist.org/nwb/sop/d/new-premium-ieee-488-gpib/6752058191.html 20-Nov-18 11:14 PM that is 1 remarkably cheap for a gpib cable 20-Nov-18 11:14 PM and 2 not really what i expected to find in the computer parts section? 20-Nov-18 11:16 PM yea thats a pretty good price 20-Nov-18 11:16 PM @qualia you said you want a 13Mhz amplifier? 20-Nov-18 11:16 PM I did too ;; 20-Nov-18 11:17 PM kindayeah 20-Nov-18 11:17 PM wait 20-Nov-18 11:17 PM i sort of want to build one, but 20-Nov-18 11:17 PM whatcha got 20-Nov-18 11:17 PM leers 20-Nov-18 11:17 PM 13.56 MHz specifically, ISM band 20-Nov-18 11:18 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20181121_081800-51B4D.jpg 20-Nov-18 11:18 PM https://boston.craigslist.org/nos/sop/d/nvidia-gtxgb-gddr5/6745885015.html "This card is less than a year old ,Came out of my Gaming PC never been overclocked or used for mining" oh boy i do not believe that 20-Nov-18 11:18 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20181121_081837-417BB.jpg 20-Nov-18 11:19 PM you know, now that i think of it, that frequency is so low i think it would be usable on basically any amplifier 20-Nov-18 11:19 PM how much power output do you need? 20-Nov-18 11:19 PM i feel like building one & the associated umpteenth-pole notch filters to keep the FCC from clobbering me to smithereens would be an awesome little project 20-Nov-18 11:19 PM this is some kind od RF amplifier I got gitfted by the friend who helped getting the turbopump 20-Nov-18 11:20 PM oo 20-Nov-18 11:20 PM i was thinking like, less than 20W 20-Nov-18 11:20 PM https://boston.craigslist.org/gbs/sop/d/2x-zotac-geforce-1080-amp/6740832948.html 20-Nov-18 11:20 PM I think this was 100W or something. 20-Nov-18 11:20 PM "Used briefly for deep learning" 20-Nov-18 11:20 PM now that i do believe 20-Nov-18 11:20 PM n any case, I can't use it. 20-Nov-18 11:21 PM 'deeply learned that deep learning wasn't the learnings i needed, deeply' 20-Nov-18 11:21 PM "upgraded to the Titan Xp when it came out" 20-Nov-18 11:21 PM they're selling 2 20-Nov-18 11:21 PM how much you wanna bet they splurged using their research budget 20-Nov-18 11:21 PM and then the titan came out and they realized "aw dangit now i gotta make that money back" 20-Nov-18 11:22 PM my browser is full of craigslist tabs 20-Nov-18 11:22 PM soz 20-Nov-18 11:22 PM i don't even live near any of this !!! 20-Nov-18 11:22 PM yeah but now you can use the tabs to triangulate my address 20-Nov-18 11:23 PM beep boop ENHANCE "United States" 20-Nov-18 11:23 PM got 'em 20-Nov-18 11:24 PM XDDDDDDDD 20-Nov-18 11:25 PM oh no ive been doxed again 20-Nov-18 11:25 PM i never should have used the internet 20-Nov-18 11:25 PM my mother was right 20-Nov-18 11:25 PM oh wow craigslist tools have even better selections, neat 20-Nov-18 11:25 PM oh right i was going to order machine screws for my printer 20-Nov-18 11:25 PM I spaced out and order 3/8" machine screws and nuts instead of 1/8" machine screws and nuts 20-Nov-18 11:25 PM and now I have uh 20-Nov-18 11:25 PM colossal garantuan machine screws 20-Nov-18 11:33 PM whoops 20-Nov-18 11:34 PM so if anyone needs big machine screws lmk I have to get rid of these somehow 20-Nov-18 11:37 PM XDDDDD 20-Nov-18 11:37 PM No thanks, metric here. 20-Nov-18 11:37 PM you can convert! 20-Nov-18 11:38 PM lathe them to size 20-Nov-18 11:38 PM why does craigslist have a linux discussion forum? 20-Nov-18 11:38 PM Don't mess with my latte. XD 20-Nov-18 11:38 PM that is specifically regional? 20-Nov-18 11:38 PM what must that be like? 20-Nov-18 11:38 PM OH MY GOD 20-Nov-18 11:38 PM https://boston.craigslist.org/gbs/hvo/d/lambda-physik-compex-102/6745254678.html 20-Nov-18 11:38 PM WHAT 20-Nov-18 11:38 PM Lambda Physik Laser for 2k 20-Nov-18 11:40 PM well it's like how craigslist personals used to be a thing but instead it's more like 'f4f seeking experienced administrator to rebuild my initrd for bootsplash funtimes' 20-Nov-18 11:40 PM should I buy this? 20-Nov-18 11:40 PM also, lewd 20-Nov-18 11:40 PM missed encounters: 20-Nov-18 11:41 PM 'that clever print statement that just scrolled past way too fast during my gentoo recompile' 20-Nov-18 11:41 PM "subway encounter. You were developing an exploit for OpenBSD on a 2016 MacBook running Redhat" 20-Nov-18 11:41 PM should I buy this gargantuan laser? 20-Nov-18 11:41 PM this one is actually within my price range if i really stretch and also sell some plasma 20-Nov-18 11:43 PM do you need it. 20-Nov-18 11:43 PM well no obviously not 20-Nov-18 11:43 PM but do i /need/ anyhting? 20-Nov-18 11:43 PM leers! 20-Nov-18 11:43 PM food, water, meds, excimer lasers 20-Nov-18 11:44 PM ohhhhh 20-Nov-18 11:44 PM ok 20-Nov-18 11:44 PM yes i need it 20-Nov-18 11:44 PM oh man I see the point of this discord now 20-Nov-18 11:44 PM @hedgeberg what will you lase? 20-Nov-18 11:44 PM its to enable the worst spending behaviors 20-Nov-18 11:44 PM >_> 20-Nov-18 11:45 PM @iximeow well i mean, i figure its probably a bit too powerful for doing hair removal... 20-Nov-18 11:45 PM but I can try! 20-Nov-18 11:45 PM definitely hasn't spent, like.. thousands.. on stainless steel pipes.. 20-Nov-18 11:45 PM ... let me know how that works out because i want hair removal via Ridiculously Excessive Laser 20-Nov-18 11:46 PM if you set up enough beamsplitters & spreaders maybe you could do your whole body at once 20-Nov-18 11:46 PM "not only do we remove the hair, we also kill the folicle and char your bone 20-Nov-18 11:46 PM " 20-Nov-18 11:46 PM foomp 20-Nov-18 11:46 PM faint ozone and burnt hair smell EUREKA 20-Nov-18 11:46 PM Haven't had this much fun since ages. 20-Nov-18 11:46 PM thanks, people. 20-Nov-18 11:46 PM I'll use copper tape to protect the hair i want to keep 20-Nov-18 11:46 PM itll be great for my dysphoria 20-Nov-18 11:46 PM faraday mustache 20-Nov-18 11:46 PM and stylin as hec 20-Nov-18 11:48 PM Make sure to show the innards if you get it. 20-Nov-18 11:49 PM im really, really tempted honestly 20-Nov-18 11:49 PM im going to bookmark that 20-Nov-18 11:50 PM @hedgeberg can i ask what you do 20-Nov-18 11:50 PM well, now I work in cybersecurity 20-Nov-18 11:50 PM oh, condolences 20-Nov-18 11:50 PM condolen--- 20-Nov-18 11:51 PM i was an analog circuits/ic's/device physics/materials person 20-Nov-18 11:51 PM o neat 20-Nov-18 11:51 PM why the switch? (if you don't mind) 20-Nov-18 11:52 PM I started doing fault injection on game consoles and that was way the heck easier to get a job in 20-Nov-18 11:52 PM and i didnt need to get a phd 20-Nov-18 11:52 PM ah yeh that'll do it 20-Nov-18 11:52 PM I was really done with academia 20-Nov-18 11:52 PM my program was weird, i was kinda like, a year and a half into my PhD work when I finished undergrad? and I put in my app and it took forever to hear back 20-Nov-18 11:52 PM and when i finally did it was rejected 20-Nov-18 11:52 PM and i went to the professor who said he would let me continue my research as a phd student 20-Nov-18 11:52 PM and he was like "oh, yeah, uh, sorry. I had been meaning to tell you, I took a job as dean of engineering at U hawaii" 20-Nov-18 11:52 PM which, you know 20-Nov-18 11:53 PM ..... uh 20-Nov-18 11:54 PM would have been great to know before I put in the app 20-Nov-18 11:54 PM right 20-Nov-18 11:54 PM good for him but also that seems like something you communicate timely 20-Nov-18 11:54 PM and I had already been kinda sick of academia at that point 20-Nov-18 11:54 PM its not a good fit for me 20-Nov-18 11:54 PM and yet, now here i am working sort of for MIT and sort of not, in a bizarre spooky cybersecurity space 20-Nov-18 11:54 PM but its kinda neat because i get to do weird tool design for weird systems 20-Nov-18 11:54 PM plus if i really want to, i can take mit courses for free, so i could finish out a grad degree and switch back to cleanroom stuff if i really wanted 20-Nov-18 11:56 PM i never got to do the academia thing at all and i kinda wish i could go do it, like, now 20-Nov-18 11:56 PM after like almost a decade in tech 20-Nov-18 11:56 PM yeah, idk 20-Nov-18 11:56 PM its 20-Nov-18 11:56 PM or at least try it i guess 20-Nov-18 11:56 PM im not going to lie, it didnt fit well with me 20-Nov-18 11:56 PM I like teaching, but so many students just 20-Nov-18 11:56 PM yup yup 20-Nov-18 11:56 PM that is my bad 20-Nov-18 11:56 PM so many students just didnt give a dang 20-Nov-18 11:56 PM and like 20-Nov-18 11:57 PM yeah i love teaching and showing stuff off but ONLY if people actually like. care 20-Nov-18 11:57 PM all they wanted was to get their pristine perfect 4.0+ GPA and not learn anything 20-Nov-18 11:58 PM i have not and will not ever grow out of show and tell 20-Nov-18 11:58 PM I was teaching a lab course, and i had this guy who was graduating that semester 20-Nov-18 11:58 PM and he was really struggling 20-Nov-18 11:58 PM (our university did ECE, so to graduate you needed to take all 4 "core" courses; analog, sigproc, low-level comp-systems, and digital architecture) 20-Nov-18 11:58 PM and this guy had put off the analog circuits course as long as possible 20-Nov-18 11:58 PM so, I asked him what the regions of operation of a MOSFET were 20-Nov-18 11:58 PM and he just looked at me dumbfounded 20-Nov-18 11:58 PM and I was like "dude, youre graduating. This was just covered in the course. You need to know this. I don't care if you're flunking the course or anything, this is knowledge you really need to have" 20-Nov-18 11:58 PM turns out dude was getting an A mostly by just rote memorization of problems and number substitution 21-Nov-18 12:00 AM ouch 21-Nov-18 12:00 AM i wish i could answer that, and (more importantly) everything preceeding that 21-Nov-18 12:00 AM that is knowledge i'd love to learn but i can't afford to do anything but self-teach piecemeal between working fulltime 21-Nov-18 12:02 AM i found that the students that had the worst grades were both the happiest and the most knowledgable, and i guess at some point that just eroded my faith 21-Nov-18 12:02 AM I have a friend workin at HP spain, and he tells me how useless many of the engineers there are, with basic things, like breathing. XD 21-Nov-18 12:02 AM admittedly grad work is different, but then its kinda doing your time to further someone else's career 21-Nov-18 12:02 AM well that just prepares you for the industry , 21-Nov-18 12:02 AM coughs 21-Nov-18 12:03 AM the niche i landed in isnt private sector and it isnt academia and it isnt for profit at all 21-Nov-18 12:03 AM and I love that 21-Nov-18 12:03 AM at this point i dont think I could ever work for a for-profit institution 21-Nov-18 12:03 AM oof 21-Nov-18 12:04 AM d'oh 21-Nov-18 12:04 AM @iximeow yeah, i have no intention to go near the industry again 21-Nov-18 12:04 AM oh right the other thing about academia (and admittedly most of the cybersecurity industry) is the ego 21-Nov-18 12:04 AM worked at disney research for 6 months 21-Nov-18 12:04 AM boss was horrible, triggered a depressive relapse, and then published my research after i left without telling me or creditting me 21-Nov-18 12:04 AM idk, prolly dont listen to me admittedly, at this point im a cynic about a lot of stem 21-Nov-18 12:06 AM it's like. the thing that i think i would love about school is that i could see a linearized composition of stuff to learn in an order to reach some particular vision of mastery of a subject by someone else's determination, and. like. that would be useful because then i can go fly off in some random direction with the confidence that i have walked through the prerequisites and won't be like reading a plasma physics book on the train and have to stop completely because i don't know what a dot over a variable means 21-Nov-18 12:06 AM In the team I am part of, I try to ensure we don't recruit people with big egos. 21-Nov-18 12:06 AM Good morning! 21-Nov-18 12:06 AM I have had enough of egos in cybersec. 21-Nov-18 12:07 AM yeah. it really gets to you after not long. 21-Nov-18 12:07 AM and my grades would probably not be anything to write home about in the slightest because if i break myself in half to achieve someone else's vision of success again i'm gonna burn out and probably not recover from it 21-Nov-18 12:07 AM @hedgeberg my industry quip was also fairly cynical and sarcastic, i'm in a very uncomfortable situation w.r.t employer, manager(s), and uh, reappropriation of work 21-Nov-18 12:07 AM industry bad 21-Nov-18 12:07 AM There have been some companies I have refused to work due to people with egos larger than the building... 21-Nov-18 12:07 AM Morning! 21-Nov-18 12:08 AM same 21-Nov-18 12:08 AM morning, also! 21-Nov-18 12:08 AM Morn bTw 21-Nov-18 12:08 AM it's kinda late night talk time? 21-Nov-18 12:08 AM yea it sure is midnight rn 21-Nov-18 12:08 AM heh 21-Nov-18 12:08 AM Yee Haw 21-Nov-18 12:08 AM Not here! 21-Nov-18 12:08 AM Midnight? It's 9 am! 21-Nov-18 12:08 AM (the late night) 21-Nov-18 12:08 AM @qualia i really really really wish notation was easier to look up 21-Nov-18 12:08 AM I worked with a certain person who gaslit the heck out of me and then threw me and a few others to the curb, been hard to not find egos extremely grating after that 21-Nov-18 12:08 AM yeah, notation is awful 21-Nov-18 12:08 AM here neither 21-Nov-18 12:09 AM ?? @AdamMcCombs it doesnt censor h#ll 21-Nov-18 12:09 AM physics people especially seem to like to make stuff up or stick with ancient notation standards 21-Nov-18 12:09 AM Oh joy, @hedgeberg no one deserves that. 21-Nov-18 12:09 AM that or a lot of books are just old but still useful 21-Nov-18 12:09 AM yeah man totaly 9:09 21-Nov-18 12:09 AM am 21-Nov-18 12:09 AM anyway @qualia thats the thing about grad school: reading books on the train and trying to parse notation is most of it 21-Nov-18 12:10 AM I always cringe when my gf tells me horror stories about college? (university?)...I know that is not meant for me. 21-Nov-18 12:10 AM my inside voice sounds like klaus from american dad 21-Nov-18 12:10 AM like, i gurantee you are already far more talented, certifiably, than most people with at least a masters degree, if not a PhD 21-Nov-18 12:11 AM who? 21-Nov-18 12:11 AM sshhh don't do that to my ego 21-Nov-18 12:11 AM it's bad for me 21-Nov-18 12:11 AM A bit of ego is always good. 21-Nov-18 12:11 AM honestly most of the people here 21-Nov-18 12:11 AM It's too much of it that breaks the vase. 21-Nov-18 12:11 AM all of you 21-Nov-18 12:12 AM So qucik poll, is midnight to late for be to be ripping sheets of plywood with a circular saw outside? 21-Nov-18 12:12 AM XDD 21-Nov-18 12:12 AM i learned everything i know from low-quality nightposting on twitter and then getting told off by adults who actually know what they're doing 21-Nov-18 12:12 AM depends 21-Nov-18 12:12 AM if you can handle your own equipment and lab, you can do better than most grad students 21-Nov-18 12:12 AM my first thought was 'depends on zoning laws' 21-Nov-18 12:12 AM do you live in a single house, and are doing it in the basement, living alone? 21-Nov-18 12:12 AM then, no, it's not too late. 21-Nov-18 12:12 AM yeah, those nifty adults man 21-Nov-18 12:13 AM ah-hem officer this area is zoned Light Commercial thank you very much 21-Nov-18 12:13 AM Single house, but outside probably within earshot of the neighbors... 21-Nov-18 12:13 AM with their sophisticated language skills and stuf flike that 21-Nov-18 12:13 AM Adulting is overrated anyhow. 21-Nov-18 12:13 AM lol no it is very much not commercial of any sort 21-Nov-18 12:13 AM @Zhang correct! 21-Nov-18 12:13 AM @hedgeberg I really have to make that "Handled 72%HF and still alive" badge 21-Nov-18 12:13 AM i don't particularly want to but might end up handling HF at some point 21-Nov-18 12:13 AM "still" :3 21-Nov-18 12:14 AM @AdamMcCombs if you are underground, the sound should be muffled enough. 21-Nov-18 12:14 AM Ick yeah I don't want to get near hf ever again 21-Nov-18 12:14 AM @AdamMcCombs don't do heavy cutting when people are asleep, just in case you get injured 21-Nov-18 12:14 AM Having Fun? 21-Nov-18 12:14 AM jk 21-Nov-18 12:15 AM Know I'm a pain about it but srsly safety is important 21-Nov-18 12:15 AM ^ honestly 21-Nov-18 12:15 AM Almost died more than a couple times 21-Nov-18 12:15 AM it's like war dude 21-Nov-18 12:15 AM Having Fun i mean 21-Nov-18 12:15 AM having fun: like war, dude 21-Nov-18 12:15 AM Lab in university had a cylinder of pure hydrogen, a cylinder of pure methane, and a cylinder of argon 21-Nov-18 12:15 AM Naa, noone is a pain in the ash, as safety is concerned, it's the other pepople being careless. 21-Nov-18 12:15 AM n00n you go hard apparently 21-Nov-18 12:16 AM (test) carelass 21-Nov-18 12:16 AM i think that's fixed 21-Nov-18 12:16 AM XD 21-Nov-18 12:16 AM no srsly, you've the proper "antidotes"? like u know calcium gluconate 21-Nov-18 12:16 AM Made me paranoid enough to instill the fear of catastrophix failures 21-Nov-18 12:16 AM Oh god 21-Nov-18 12:17 AM @hedgeberg yeah people keep telling me like 'just try to find a cylinder of deuterium!' and i'm like i don't care if a lecture bottle is only half a liter i don't want to deal with /compressed hydrogen, but it burns even hotter/ in my bedroom 21-Nov-18 12:17 AM argon is fairly neutral right? so that one you'd only have to be worried about it like, decompressing? 21-Nov-18 12:17 AM also half a liter times whatever adiabatic expansion ratio is not a small volume anyways 21-Nov-18 12:17 AM argon's suffocate-y, at least 21-Nov-18 12:17 AM ah right 21-Nov-18 12:17 AM @N00N 21-Nov-18 12:17 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20181121_091748-3B125.jpg 21-Nov-18 12:17 AM Did you know that in fabs where they have super high purity HF, they have syringes of the stuff? 21-Nov-18 12:18 AM @Nixie yeah 21-Nov-18 12:18 AM They inject you with it 21-Nov-18 12:18 AM nnhh 21-Nov-18 12:18 AM i don't like it 21-Nov-18 12:18 AM And, the way you know it's working? 21-Nov-18 12:18 AM When it stops hurting 21-Nov-18 12:18 AM Just because, or when an accident happens? XDDDDDDDDDD 21-Nov-18 12:18 AM It's supposed to be heck 21-Nov-18 12:18 AM oh hf == hydrogen flouride not high frequency 21-Nov-18 12:18 AM and not Having Fun 21-Nov-18 12:18 AM parse error at "injecting high frequency" 21-Nov-18 12:18 AM And they won't numb you because they need to know if they dosed you high enough 21-Nov-18 12:18 AM And the only way to know for sure? When it stops hurting within the right time frame, of about 4 hours 21-Nov-18 12:19 AM ROFL! 21-Nov-18 12:19 AM @Nixie i've calcium gluconate for injection too 21-Nov-18 12:19 AM I will Have Fun on this semiconductor to remove the oxide layer 21-Nov-18 12:19 AM /dies horribly/ 21-Nov-18 12:19 AM don't know exactly how to apply, but hey! will see 21-Nov-18 12:20 AM So, for the 4 hours while you're waiting to see if it worked? You feel like your skin is burning off, apparently 21-Nov-18 12:20 AM @Nixie that you Had Fun %) 21-Nov-18 12:20 AM than 21-Nov-18 12:20 AM then 21-Nov-18 12:20 AM fluorine needs to quit being so dang negative 21-Nov-18 12:20 AM I do not want to go near HF ever again. 21-Nov-18 12:20 AM @hedgeberg for that i've lidocain and procain and stuff like that 21-Nov-18 12:20 AM Yeah! How dare it! 21-Nov-18 12:20 AM How dare it absorb a free electron! 21-Nov-18 12:21 AM i know, that's not they way it should be used, but ... 21-Nov-18 12:21 AM It only ever becomes more negative!!! 21-Nov-18 12:21 AM chemistry like legit scares the muffins out of me in general for a lot of reasons 21-Nov-18 12:21 AM which is a shame because chemistry is.. gestures widely interesting 21-Nov-18 12:21 AM AFAIK it's important to feel the pain, to be sure that the calcium gluconate works, right? 21-Nov-18 12:21 AM But you still need it to understand and do processes 21-Nov-18 12:21 AM Yup @N00N 21-Nov-18 12:21 AM you can hide, but you can't outrun needing it. 21-Nov-18 12:22 AM oh for sure @Nixie 21-Nov-18 12:22 AM At least process engineering doesn't need orgo usually 21-Nov-18 12:22 AM My mother was an orgo chem. She tried to tell me the other day that "gold is a noble metal and it can't ionize!" 21-Nov-18 12:23 AM XD 21-Nov-18 12:23 AM On the other hand she understands rna transcription and I absolutely do not, so like 21-Nov-18 12:24 AM RHIC would like to have some words with you 21-Nov-18 12:24 AM Rhic? 21-Nov-18 12:24 AM yeah, RHIC? 21-Nov-18 12:24 AM the relativistic heavy ion collider 21-Nov-18 12:24 AM they smash gold ions together 21-Nov-18 12:24 AM mx, go streaming. 21-Nov-18 12:24 AM Red-hot ion cannon? 21-Nov-18 12:24 AM among other things 21-Nov-18 12:24 AM Oh, yeah 21-Nov-18 12:24 AM AH! 21-Nov-18 12:25 AM So it is the red-hot ion cannon! 21-Nov-18 12:25 AM I have to wait like 1h more to start machining stainless 21-Nov-18 12:25 AM I was right! 21-Nov-18 12:25 AM I need entertainment 21-Nov-18 12:25 AM LHC has started doing Pb-Pb collisions for hot quark-gluon plasma studies i'm so excited 21-Nov-18 12:25 AM all of the jet/TPC/calorimeter pictures coming out of it are just this absolute isotropic clusterfluff of traces, it's beautiful 21-Nov-18 12:26 AM What are they hoping to demonstrate? 21-Nov-18 12:26 AM street cred 21-Nov-18 12:26 AM i have no idea exactly 21-Nov-18 12:26 AM i haven't looked into what their specific research goals are for the beam species cutover 21-Nov-18 12:26 AM i heard QGP research 21-Nov-18 12:26 AM but haven't dug 21-Nov-18 12:27 AM afaik right now they're just doing collisions ad the highes possible energies to look for events that are not described by the standard model 21-Nov-18 12:28 AM trying to pigeonhole more of the varieties of our universe into lie groups, as you do 21-Nov-18 12:28 AM Imagine if we find a way to prove the standard model 21-Nov-18 12:28 AM And it turns out? 21-Nov-18 12:28 AM Gravity isn't supposed to fit in 21-Nov-18 12:28 AM 'hey cool we 100%'d it' 21-Nov-18 12:28 AM It's not real, it was fake the whole time 21-Nov-18 12:28 AM ehehe 21-Nov-18 12:28 AM not so detailed physics engine 21-Nov-18 12:29 AM But THEY ARE CREATING BLACK HOLES, WE ARE ALL GOING TO DIE! 21-Nov-18 12:29 AM @hedgeberg that's what it currently looks like 21-Nov-18 12:29 AM "physicists around the world: 'uh, oops'" 21-Nov-18 12:29 AM tiny elves living in the cusps of the vacuum oscillations 21-Nov-18 12:29 AM No I know @GigaSquirrel that's the joke 21-Nov-18 12:29 AM bucket brigading isosurfaces of the higgs field along 21-Nov-18 12:29 AM We were right the whole time, gravity just isn't there 21-Nov-18 12:30 AM well, according to the LHC this "gravity" thing dosen't even exist 21-Nov-18 12:30 AM It was all a practical social joke, like no soap radio 21-Nov-18 12:30 AM i mean, if this stuff here is only a simulation on a proper quantum computer, that could totally happen 21-Nov-18 12:30 AM next thing would be searching/identifying glitches 21-Nov-18 12:31 AM We can't do this 21-Nov-18 12:31 AM fault inject our own universe... 21-Nov-18 12:31 AM We can't get into simulation theory 21-Nov-18 12:31 AM @hedgeberg y not? 21-Nov-18 12:31 AM It's theology and I won't stand for it 21-Nov-18 12:31 AM no, it's physics 21-Nov-18 12:31 AM children, 21-Nov-18 12:32 AM kinda de(con)structive, but hey 21-Nov-18 12:32 AM they'll never kno 21-Nov-18 12:32 AM It absolutely is not physics! It is a theory with no mechanism for proof or disproof! That is theology! 21-Nov-18 12:32 AM XDD 21-Nov-18 12:32 AM don't make me get the basilisk in here 21-Nov-18 12:32 AM @hedgeberg that wrong, you don't know if there is a proof mechanism 21-Nov-18 12:33 AM ?mute 21-Nov-18 12:33 AM That's all I'm going to say... 21-Nov-18 12:33 AM thunderclap 21-Nov-18 12:33 AM Watch it or I'll call the Homeopathy police. 21-Nov-18 12:33 AM Yeah yeah ok 21-Nov-18 12:33 AM damn, adam beat me 21-Nov-18 12:34 AM i could stream myself 21-Nov-18 12:34 AM making some vegemite 21-Nov-18 12:34 AM "you don't have to go home but you can't stay on this topic" I get it 21-Nov-18 12:34 AM vegemite? is that an explosive? 21-Nov-18 12:34 AM @qualia \o/ 21-Nov-18 12:34 AM no you're thinking of marmite 21-Nov-18 12:34 AM Discussing theology is quite pointless. 21-Nov-18 12:34 AM Isn't Vegemite the thing British people put on toast? 21-Nov-18 12:34 AM theological mereology 21-Nov-18 12:35 AM I'll let my brain think you are going to make explosives 21-Nov-18 12:35 AM it's more fun that way. 21-Nov-18 12:35 AM yeah, {vege,mar}mite are like a spread of the yeast left over from beermaking 21-Nov-18 12:35 AM it's intensely salty and umami as all get out 21-Nov-18 12:35 AM explosives for break feasts 21-Nov-18 12:36 AM XDDDD 21-Nov-18 12:36 AM talk about an energizing start to your day 21-Nov-18 12:36 AM hell yea. 21-Nov-18 12:36 AM i see coffeee & coffeee and more coffee? 21-Nov-18 12:36 AM (leaving the typo for maximum effect) 21-Nov-18 12:36 AM If by energizing you mean severely dehydrating, then sure 21-Nov-18 12:36 AM mhh, coffee :3 21-Nov-18 12:36 AM cordite? more like BOREDite! GIMME my VEGEMITE! 21-Nov-18 12:36 AM and beer 21-Nov-18 12:36 AM germans always have beer 21-Nov-18 12:37 AM @GigaSquirrel doesn't trust people who do not drink coffee... /and I do not do that.../ 21-Nov-18 12:37 AM it's not that I can't stand those people, but they scare me 21-Nov-18 12:37 AM But will have some explosive morning, thanks. 21-Nov-18 12:37 AM (already corrected the typo, sorry Giga. 21-Nov-18 12:38 AM ^^ 21-Nov-18 12:38 AM beer is the perfect isotonic thirst quencher 21-Nov-18 12:38 AM BOOOO 21-Nov-18 12:38 AM i am an espresso enby 21-Nov-18 12:38 AM My partner just got me a pourover unit for our anniversary :3 21-Nov-18 12:38 AM the quenchiest! 21-Nov-18 12:38 AM pourover? 21-Nov-18 12:38 AM oh i love pourover too :o 21-Nov-18 12:38 AM sounds like something in Mars 21-Nov-18 12:38 AM Its the snootiest way to make coffee @nixie 21-Nov-18 12:39 AM (i totally lack knowledge about coffee culture) 21-Nov-18 12:39 AM You literally pour the hot water over the grounds by hand so you can control how weak or strong the coffee is 21-Nov-18 12:39 AM put some wheels on it and give it to elon musk, should reach mars sometime. 21-Nov-18 12:39 AM interesting. 21-Nov-18 12:39 AM Or better say coffee time 21-Nov-18 12:39 AM i want coffee ;.; 21-Nov-18 12:40 AM @Nixie https://www.youtube.com/watch?v=fVDOB9mby_w 21-Nov-18 12:40 AM but it's midnight... 21-Nov-18 12:40 AM Oh speaking of my partner, anyone mind if I post a pic? I took this earlier and I think it's hilarious 21-Nov-18 12:40 AM I would like to pause for a moment to interject thusly: 21-Nov-18 12:40 AM there is now an #off-topic-thats-sometimes-on-topic 21-Nov-18 12:40 AM Oh 21-Nov-18 12:40 AM let us venture over yonder 21-Nov-18 12:40 AM sry 21-Nov-18 12:40 AM Yeah 21-Nov-18 12:40 AM das ok it just came into existence 21-Nov-18 12:40 AM like SECONDS ago. 21-Nov-18 12:40 AM y'all good 21-Nov-18 12:41 AM Little seconds ago 21-Nov-18 12:42 AM You're alone, Adam. /POOF!/ 21-Nov-18 12:45 AM noOoO 21-Nov-18 12:45 AM I have this whole Varian V-200 turbopump. I can make it spin. It needs watercooling, and it almost certainly needs to be cleaned and refilled with turbo oil, 'cos it got inverted in transit, and I think that this thing is not meant to be inverted in transit. 21-Nov-18 12:45 AM I'm considering getting a 6" CF to 4.5" CF zero-length adapter, sticking a spare 4.5" tee on it, putting my RGA on that tee once it gets here, and .. some other kind of converter on the other-other end of the tee, and making a very awkward and not-at-all-portable mass spectrometer/sniffer 21-Nov-18 12:45 AM that or i just qualify everything and try to sell it on fleabay as a bundle, but that feels kinda gross. 21-Nov-18 12:51 AM Yeah if you want to sell the bundle I think I have a buyer... It would be better if it was a portable turbo 21-Nov-18 12:52 AM I'd love to find a portable turbo, tbh. 21-Nov-18 12:52 AM me2 21-Nov-18 12:52 AM Like the little itty bitty baby KF thing John has? 21-Nov-18 12:52 AM But, like 21-Nov-18 12:52 AM but i guess i want one without oil 21-Nov-18 12:52 AM i assume you can't really move it once it's on 21-Nov-18 12:52 AM almost all new ones don't have oil 21-Nov-18 12:52 AM yeah 21-Nov-18 12:52 AM but i'm a cheapo guy 21-Nov-18 12:53 AM Those magnets eh? 21-Nov-18 12:53 AM my varian v-200 is actually, like, .. not branded as such. it actually has edwards/elettrorava(sp?) branding 21-Nov-18 12:53 AM new == expensive 21-Nov-18 12:53 AM ETP6/200 21-Nov-18 12:53 AM i've a "oil free" rig, but i need more rigs! 21-Nov-18 12:53 AM since bake out and stuff takes years!11 (ok, days) 21-Nov-18 12:53 AM would be cool to have i dunno 5 rigs and "revolve" 21-Nov-18 12:54 AM i'm too elastomeric for bakeouts 21-Nov-18 12:54 AM also i did not put anti-seize on like any of my non-silver-coated bolts, so, 21-Nov-18 12:55 AM Oh 21-Nov-18 12:55 AM That might be fun... 21-Nov-18 12:56 AM hope i don't die 21-Nov-18 12:56 AM y the die-ing? 21-Nov-18 12:56 AM silver? vampire stuff? 21-Nov-18 12:56 AM %) 21-Nov-18 12:56 AM like, if i need to take this thing apart at some point 21-Nov-18 12:56 AM and if thermal expansion's gone and seized up the jankier bolts.. 21-Nov-18 12:56 AM ok, what do you expect? 21-Nov-18 12:56 AM explosive desintegration? 21-Nov-18 12:57 AM Serious question, what was that colossal laser intended for? 21-Nov-18 12:57 AM High-power laser cutter? 21-Nov-18 12:57 AM ok, now im interested 21-Nov-18 12:57 AM high power laser? 21-Nov-18 12:57 AM CO_2? 21-Nov-18 12:58 AM yeah, what laser? 21-Nov-18 12:58 AM Always use antisieze 21-Nov-18 12:58 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180816_211954-8991A.jpg 21-Nov-18 12:58 AM ok high power CO_2 and scary stuff: SILEX? 21-Nov-18 12:58 AM like the custom threaded studs i made out of 304SS for this weird strange custom 6"-CF-to-4.5"-CF-to-3x-1.33"-CF thing? if those things have decided to seize up somewhere inside those zero-length flanges, i'll have a huge pain in the butt of a time getting them out 21-Nov-18 12:58 AM >.> 21-Nov-18 12:58 AM ^ that's what i'm worried about, yeah. 21-Nov-18 12:59 AM ah ok 21-Nov-18 12:59 AM If you don't just do this 21-Nov-18 12:59 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_junoyt-8BA7F.jpg 21-Nov-18 12:59 AM @AdamMcCombs do you have a recommendation for something other than 'a tiny bit of DCHVG' (per the rad attendant at duniway's suggestion) 21-Nov-18 12:59 AM that leverage can't be good. 21-Nov-18 12:59 AM for an antiseize compound 21-Nov-18 12:59 AM Moly 21-Nov-18 01:00 AM like, graphite/molybdenum disulfide? 21-Nov-18 01:00 AM Yeah the stuff that comes in the grey jar 21-Nov-18 01:00 AM That or lead grease but that's probably ilegal in California 21-Nov-18 01:00 AM ... 21-Nov-18 01:00 AM Ok look we cannot start calling MoS2 moly 21-Nov-18 01:00 AM We cannot 21-Nov-18 01:01 AM oh, that laser 21-Nov-18 01:01 AM Yeah fair 21-Nov-18 01:01 AM https://boston.craigslist.org/gbs/hvo/d/lambda-physik-compex-102/6745254678.html 21-Nov-18 01:01 AM Yeah that one 21-Nov-18 01:02 AM uhhh, an eximer laser 21-Nov-18 01:02 AM I've only ever seen one in a superconductor deposition system 21-Nov-18 01:02 AM So yes I should buy this 21-Nov-18 01:02 AM Is what you're saying 21-Nov-18 01:02 AM absolutely 21-Nov-18 01:03 AM 193nm, 4.8W, 20Hz/240mJ 21-Nov-18 01:03 AM hard af UV 21-Nov-18 01:03 AM what is it used for in the deposition? vaporize the superconductor? 21-Nov-18 01:03 AM Jesus, yeah 21-Nov-18 01:03 AM it's air cooled! 21-Nov-18 01:03 AM @Nixie uh, could also be energizing deposited materials 21-Nov-18 01:03 AM ahm 21-Nov-18 01:04 AM But idk 21-Nov-18 01:04 AM That's just me spitballing 21-Nov-18 01:04 AM oh wait i take that back there are a couple different wavelengths of COMPex 102 21-Nov-18 01:04 AM @Nixie Yep, ~100W CO2 for heating the area on which the sc is to be deposited on and µs pulses from the eximer for vaporizing the sc 21-Nov-18 01:04 AM Oh wow. 21-Nov-18 01:04 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/1542791067_20181121-011127-B6B9C.png 21-Nov-18 01:04 AM What I really want to get on is free@mit.edu 21-Nov-18 01:05 AM @AdamMcCombs wait that's a thing? 21-Nov-18 01:05 AM @AdamMcCombs have you met @hedgeberg 21-Nov-18 01:05 AM We were just talking about this 21-Nov-18 01:05 AM I work for MIT 21-Nov-18 01:05 AM adds Communications Facilitator to resume 21-Nov-18 01:05 AM How do you think there is a machine shop in the basements of ec 21-Nov-18 01:05 AM No idea I don't work on campus 21-Nov-18 01:05 AM My situation is weird 21-Nov-18 01:06 AM Friend got an optic table off of it 21-Nov-18 01:07 AM do you guys make SC coatings? 21-Nov-18 01:07 AM /goes away to machine some stainless/ 21-Nov-18 01:07 AM not me, but I know some who do 21-Nov-18 01:08 AM i want to build kinda shielding from HTC like YBCO or BSSCO 21-Nov-18 01:08 AM Mmmk so what you're saying is I should sign up for this mail list and cue you guys in if anything good shows up? 21-Nov-18 01:08 AM for "large" structures electrophoresis is the way to go, right? 21-Nov-18 01:08 AM @hedgeberg would be awesome 21-Nov-18 01:08 AM My understanding is it's for students, but yes 21-Nov-18 01:09 AM I am sort of technically a student? Or, I can be 21-Nov-18 01:09 AM it is really hard to deposit HTSC onto anything, because you have to get the crystal structure just right 21-Nov-18 01:09 AM they either use metallic SCs or or the lasersystem for HTSC 21-Nov-18 01:10 AM @GigaSquirrel yeah, you electrophoresis deposit small crystals on it 21-Nov-18 01:10 AM and then put the whole structure into a sinter oven 21-Nov-18 01:11 AM in that case you already know more than I do ^^ 21-Nov-18 01:11 AM (with many problems in-between i guess) 21-Nov-18 01:12 AM ^^ 21-Nov-18 01:12 AM but that's normal with SCs 21-Nov-18 01:13 AM yeah the devil is in the details 21-Nov-18 01:37 AM Always is though, right? 21-Nov-18 01:40 AM yeah 21-Nov-18 01:59 AM I think a lot of the g-cards on the market are new nvidia stock, as they bet on the bubble and now no one buys those models anymore 21-Nov-18 01:59 AM And @N00N I bet the non-use of painkillers is conditioning, so one doesn't splash HF on the self again… 21-Nov-18 03:11 AM @Leona lol 21-Nov-18 03:11 AM what's your fav UHV ceramics substrate? alumina? 21-Nov-18 03:11 AM for PCB kinda stuff 21-Nov-18 05:23 AM ... Anyone know how quickly acetone dissolves plastic droppers? Like: can I use them, but just for a short time, or do they literally fall apart before I've filled them completely? 21-Nov-18 05:38 AM what plastic? 21-Nov-18 05:38 AM pp / pe / pet is very resistant 21-Nov-18 05:44 AM Cool. I think it's milk jug plastic (pe?) 21-Nov-18 05:45 AM yep, most likely pe 21-Nov-18 05:47 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181121_1446002-0C664.jpg 21-Nov-18 05:49 AM lools Like Pe 21-Nov-18 06:00 AM Yep, thanks 21-Nov-18 06:21 AM It should work no problem. 21-Nov-18 08:58 AM Btw, I use empty 500ml cocacola bottles to store them before throwing them away. They are hermetic enough for a day or two. (Chloroform mainly) 21-Nov-18 09:19 AM the droppers? Do you do that so they fully outgas and you can dispose them in the domestic garbage? @Nixie 21-Nov-18 09:45 AM Joined the server. 21-Nov-18 09:45 AM Hey @vinkmar 21-Nov-18 09:47 AM Hallo 21-Nov-18 10:00 AM hi 21-Nov-18 10:06 AM moin! 21-Nov-18 10:18 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181121_191256-0F1FF.jpg 21-Nov-18 10:18 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181121_191315-AEB1C.jpg 21-Nov-18 10:18 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181121_191243-D728C.jpg 21-Nov-18 10:18 AM Started repairing the cryo 21-Nov-18 10:18 AM that's the second stage 21-Nov-18 11:34 AM once all parts are ready I might make a video where I assemble the pump with a bit of explaining, would there be any interest for that? 21-Nov-18 11:44 AM @Leona more like I can store them outside the fume hood while working. (It's a homemade desktop version, not huge. 21-Nov-18 11:44 AM Yeah! 21-Nov-18 11:44 AM Me wants to see cryopump things 21-Nov-18 11:47 AM @GigaSquirrel absolutely :D 21-Nov-18 11:48 AM Yes, that would be good! 21-Nov-18 11:54 AM guess I'll have to 21-Nov-18 11:54 AM prepare for a whole lot of german-english and bad editing 21-Nov-18 12:00 PM You could do German and Subtitles, if you wanted to. 21-Nov-18 12:01 PM I'll burn that bridge when I get to it 21-Nov-18 12:04 PM :D 21-Nov-18 12:09 PM qualia, playing OBS for 12 hours... what are you doing? 21-Nov-18 12:23 PM oh, .. >.> mostly forgetting i left OBS on on my other laptop 21-Nov-18 12:24 PM I'll watch it for the pretty pictures 21-Nov-18 12:25 PM is at work, but might do streamy things later 21-Nov-18 12:27 PM I'll be sleeping that later. Too bad 21-Nov-18 12:28 PM how much later? ^^ 21-Nov-18 12:28 PM like 1 or 2 am your place? 21-Nov-18 12:28 PM that's usually when I wake up 21-Nov-18 12:29 PM snrk 21-Nov-18 12:29 PM Well, it's half past noon right now 21-Nov-18 12:29 PM and i try to Do Work Stuff until about 5... 21-Nov-18 12:29 PM .. ish.. 21-Nov-18 12:29 PM Normally I have like an hour and a half of commute after that to actually get home, but today I'm working from home 21-Nov-18 12:29 PM ... so, maybe a bit earlier today >.> 21-Nov-18 12:29 PM wanders off for a while 21-Nov-18 02:41 PM goes ti sleep Gbait everyone! 21-Nov-18 02:43 PM Good night! 21-Nov-18 03:37 PM I'm gonna go now, too, good night everyone 21-Nov-18 03:37 PM I'll get up in 8 hours and expect @qualia to be streaming at that time! 21-Nov-18 07:56 PM What's everyone up to? 21-Nov-18 08:04 PM Molecular flow simulations for my small chamber with the pumping assembly. Trying to work out some bugs. 21-Nov-18 08:04 PM Almost everything looks reasonable, but there is one odd discrepancy in the pipeline that I need to resolve. 21-Nov-18 09:11 PM Evening everyone 21-Nov-18 09:11 PM @Applied_Ion what is the fea package you are using for the sims? 21-Nov-18 09:34 PM Oh cute, someone made an ion wind plane https://youtu.be/boB6qu5dcCw 21-Nov-18 09:35 PM Oh yeah i was meaning to watch that 21-Nov-18 09:35 PM I remember one of my friends built a rocket that use the motors ion transport to power corona discharge surfaces on the fins to cause differential flow and spin up the rocket to stabilize it. 21-Nov-18 10:07 PM That's cool 21-Nov-18 10:07 PM It worked in testing but at the competion it was to hot out and the carbon fiber layup was to soft. The motor housing went through the rocket. 21-Nov-18 10:07 PM I mean talk about failure modes 21-Nov-18 11:02 PM Time for some openscad, need to print a part for my printer 21-Nov-18 11:02 PM Need a filament-guide mountpoint for the current setup, and it needs to get the job done until I finally get an enclosure built 21-Nov-18 11:02 PM Also need to modify another part from a thing I'm working on, and that's going to be painful tbh. 21-Nov-18 11:02 PM actually anyone here got any good experience with openscad? i have a question about something im going to need to do for the second part im designing 21-Nov-18 11:10 PM I used to use it a bunch 21-Nov-18 11:11 PM Yeah same here 21-Nov-18 11:11 PM basically, im going to be making a rectangular donut, and then a torus 21-Nov-18 11:11 PM I moved to inventor then fusion 360 21-Nov-18 11:11 PM and then subtract the torus from the donut, so that the outside edge slopes inward 21-Nov-18 11:11 PM ugh i really really really dont want to use cloud cad 21-Nov-18 11:11 PM i know thats stupid but i just 21-Nov-18 11:12 PM Inventor is very good 21-Nov-18 11:12 PM I moved to freecad 21-Nov-18 11:12 PM I have mixed feelings on inventor 21-Nov-18 11:12 PM i think its pretty good, but it tends to break the way i use it 21-Nov-18 11:12 PM its what i learned on 21-Nov-18 11:12 PM I use constraints a lot though so it works well for me... 21-Nov-18 11:12 PM I do too thats the issue 21-Nov-18 11:12 PM i have a problem with ending up in situations where it insists its over-constrained 21-Nov-18 11:12 PM either way, point is moot since i dont think it runs on linux 21-Nov-18 11:13 PM That was the hard part for me when going to 360 21-Nov-18 11:13 PM True 21-Nov-18 11:13 PM and i honestly just f-ing refuse to load windows on my personal laptop at this point 21-Nov-18 11:13 PM I've reached a point where, for none-work stuff, I have no use for windows 21-Nov-18 11:14 PM I wish I could be there 21-Nov-18 11:14 PM all I use my windows partition for at work is Office apps + VMs 21-Nov-18 11:15 PM Eda I'm on kicad so I'm good there but I also am on a lot of Adobe/Autodesk stuff... 21-Nov-18 11:15 PM its the reverse-engineer's curse; at some point you stop using tools and start reversing the windows build so that you can run an alternative on linux that provides more control 21-Nov-18 11:15 PM I still use windows on personal systems for certain modern games, but now that steam is working on whatever-its-called 21-Nov-18 11:15 PM "proton" I think? 21-Nov-18 11:15 PM i wont have a use for that soon 21-Nov-18 11:15 PM so then its just email and bad enterprise software on my work pc, and i have no use for it past that. and I'm getting there fast. 21-Nov-18 11:17 PM Is that that rent GPU from Amazon thing? 21-Nov-18 11:17 PM Has anyone named a software framework "neutron" yet? 21-Nov-18 11:17 PM oh, no I didnt hear about that, i dont think its a streaming thing 21-Nov-18 11:17 PM iirc its a custom wine build thing 21-Nov-18 11:17 PM basically like PlayOnLinux but with a better exe translation layer? 21-Nov-18 11:17 PM anyway, rq 21-Nov-18 11:17 PM how would I go about making a torus in openscad? 21-Nov-18 11:17 PM in inventor, I'd do a revolve operation 21-Nov-18 11:17 PM do they have an equivalent in openscad? 21-Nov-18 11:18 PM I think so 21-Nov-18 11:18 PM I always forgot openscad syntax :/ 21-Nov-18 11:18 PM pulls up a reference program 21-Nov-18 11:18 PM dont do cad frequently enough so its always slipping, which is a shame 21-Nov-18 11:19 PM I mean you could do it the hard core way defining a bunch of points with coordinate translation 21-Nov-18 11:20 PM I could define a function that does translation 21-Nov-18 11:20 PM and an angular shift 21-Nov-18 11:20 PM and then another function that loops that radially 21-Nov-18 11:20 PM No it definitely does it 21-Nov-18 11:20 PM https://en.m.wikibooks.org/wiki/OpenSCAD_User_Manual/2D_to_3D_Extrusion 21-Nov-18 11:21 PM god I love OSS 21-Nov-18 11:21 PM And it looks like it does it your way 21-Nov-18 11:21 PM oh wow this is remarkably utilitarian 21-Nov-18 11:21 PM sometimes I remember that theres a whole community of people working together to make tooling free and open and available 21-Nov-18 11:21 PM and it makes me happy 21-Nov-18 11:21 PM and then I remember that computers are bad and a mistake 21-Nov-18 11:24 PM The multi part extrude stuff is cool 21-Nov-18 11:24 PM yeah 21-Nov-18 11:24 PM its a good feature 21-Nov-18 11:24 PM I need to remember that my printer doesnt do mm, it does inches 21-Nov-18 11:24 PM Ouch 21-Nov-18 11:24 PM I'll need to scale the final shape up 21-Nov-18 11:24 PM eh 21-Nov-18 11:24 PM I made that mistake before 21-Nov-18 11:24 PM I think you can do it in scad 21-Nov-18 11:25 PM its just remembering to add an mm-to-in scaling function as a final wrapper 21-Nov-18 11:25 PM Yeah 21-Nov-18 11:25 PM since stl's are unitless 21-Nov-18 11:25 PM the bigger question is why the heck cura doesnt have the switch 21-Nov-18 11:25 PM and why it uses inches???? 21-Nov-18 11:25 PM Or do it in a built or call a global definition file 21-Nov-18 11:26 PM idk, part of me thinks cura is bad and we should all go back to skeinforge 21-Nov-18 11:26 PM i kinda miss skeinforge 21-Nov-18 11:26 PM Yeah I never used cura 21-Nov-18 11:26 PM what do you use? 21-Nov-18 11:26 PM Well I did 21-Nov-18 11:26 PM For like 10 minutes 21-Nov-18 11:26 PM Pursa slic3r 21-Nov-18 11:27 PM theres some new one people are using thats a cad tool and a printing tool now 21-Nov-18 11:27 PM i forget what its called 21-Nov-18 11:27 PM but it looks really really easy to work with, just maybe not great at detail work 21-Nov-18 11:27 PM I always liked repiteir 21-Nov-18 11:28 PM yeah, i never got into repetier myself so much besides for movement/debugging stuff 21-Nov-18 11:28 PM That's why I used it 21-Nov-18 11:28 PM yeah, imo thats what octoprint is for 21-Nov-18 11:28 PM but I'm not using octoprint rn anyway so ignore me 21-Nov-18 11:28 PM I built my printer from scratch and then put a smoothie board in 21-Nov-18 11:29 PM RepRap build? what gen? 21-Nov-18 11:29 PM Weird custome i3 21-Nov-18 11:29 PM neat 21-Nov-18 11:29 PM the new gen of i3 looks amazing tbh 21-Nov-18 11:29 PM Yeah 21-Nov-18 11:30 PM im thinking of doing a retrofit of my printer to an i3-style unit 21-Nov-18 11:30 PM but first I need to get so much other stuff figured out 21-Nov-18 11:30 PM I did hall auto bed levelling before it was cool 21-Nov-18 11:30 PM rn im working on solving the filament tensioning and then i need to get some glass bed mounts going and then I want a physical-contact autolevel probe and.... 21-Nov-18 11:30 PM etc 21-Nov-18 11:31 PM Have you seen the new bonded silicone aluminum bed from I think e3d? 21-Nov-18 11:31 PM no, but i really do like and prefer borosolicate 21-Nov-18 11:31 PM every metal bed ive ever used ends up with pitting issues 21-Nov-18 11:32 PM It's designed to have one of those easy removal plastic beds on top I think 21-Nov-18 11:32 PM Morning! 21-Nov-18 11:33 PM ehhhh, those are ok, I guess? the mods im printing are to enable an easy-remove glass bed 21-Nov-18 11:33 PM Can't help with openScad, I am a Fusion360 guy 21-Nov-18 11:33 PM they're basically spring-loaded square edge brackets 21-Nov-18 11:33 PM yeah you and everyone else 21-Nov-18 11:33 PM sorry? XD 21-Nov-18 11:33 PM and i think you're all wrong for that 21-Nov-18 11:33 PM Not gona push Fusion into you, don't worry. 21-Nov-18 11:33 PM ok lets see, what dimensions will i need for this 21-Nov-18 11:34 PM go! 21-Nov-18 11:34 PM Yeah I should try borosilicate at some point 21-Nov-18 11:34 PM I'm running kapton+hairspray 21-Nov-18 11:35 PM oh ew, yeah, borosilicate + hairspray works way better imo 21-Nov-18 11:35 PM i find kapton works really well for ABS 21-Nov-18 11:35 PM I wouldn't use it for non-abs though 21-Nov-18 11:36 PM I was doing all abs 21-Nov-18 11:36 PM oh, then why hairspray? 21-Nov-18 11:36 PM hairspray works way better for PLA afaik? 21-Nov-18 11:36 PM maybe im out of the loop? 21-Nov-18 11:36 PM OH RIGHT @AdamMcCombs did you ever see the thing i posted to twitter when I swapped nozzles on my printer? 21-Nov-18 11:37 PM My cetus has something on the plate, and doesn't use anything to hold the PLA 21-Nov-18 11:37 PM if not I should dig that up because its /wild/ 21-Nov-18 11:37 PM I wanna see too 21-Nov-18 11:37 PM (BTW, now that it's 3D printers talk time, anyone heard of a filament detector coupled to an encoder wich gets compared to the injection motor so you can detect slip of the filament and in turn infere nozzle blockage?) 21-Nov-18 11:38 PM yeah 21-Nov-18 11:38 PM that was one of the appeals of the mk1 or mk2 prusa iirc 21-Nov-18 11:38 PM I haven't run my printer since checks watch I got a sem... 21-Nov-18 11:38 PM XDDDDD 21-Nov-18 11:38 PM SEM fever 21-Nov-18 11:39 PM So I'm probably out of the loop 21-Nov-18 11:39 PM I really wish I had a fancier thermal cam... 21-Nov-18 11:39 PM No I didn't 21-Nov-18 11:39 PM looking through my pics and its all my laptop repair stuff 21-Nov-18 11:39 PM and the one I have does great but I really wish I had one of those really-high-res flir camera 21-Nov-18 11:39 PM *cameras 21-Nov-18 11:40 PM No I haven't nixie 21-Nov-18 11:40 PM (you can edit your comment instead of usin *, if you want, btw) 21-Nov-18 11:40 PM Denial is the first stage, don't worry. 21-Nov-18 11:40 PM XDDDD 21-Nov-18 11:40 PM ok uh, I swore in this tweet, so uh 21-Nov-18 11:40 PM I was talking about the encoder... 21-Nov-18 11:40 PM CONTENT WARNING: 21-Nov-18 11:40 PM https://twitter.com/hedgeberg/status/1052463687611686912 21-Nov-18 11:40 PM END CONTENT WARNING 21-Nov-18 11:41 PM Oh yeah I remember that now 21-Nov-18 11:41 PM AH!, okay @AdamMcCombs It's something stuck in my head, maybe as an add-on module for the printer. 21-Nov-18 11:41 PM anyway @Nixie there you go since you also wanted to see 21-Nov-18 11:41 PM Yes, thanks! 21-Nov-18 11:41 PM That's bad 21-Nov-18 11:42 PM click through, look at all 3 pics 21-Nov-18 11:42 PM the last one makes it much clearer 21-Nov-18 11:42 PM forbidden oreo crumbs XDDDDDDDDDD 21-Nov-18 11:42 PM yeah, I ❤ jam 21-Nov-18 11:42 PM hes a good kid 21-Nov-18 11:42 PM still weird looking at that 21-Nov-18 11:42 PM its the width of the nozzle 21-Nov-18 11:43 PM I have to replace all my nozzles in my cetus... :/ 21-Nov-18 11:43 PM And it worked at all? 21-Nov-18 11:43 PM sort of? 21-Nov-18 11:43 PM if i ran it like 20C above where I wanted it? 21-Nov-18 11:43 PM this thing had issues 21-Nov-18 11:43 PM the filament lump probably formed when the thermistor was cracked 21-Nov-18 11:44 PM That would be catasstrophic 21-Nov-18 11:44 PM so it was usually registering as way above where it actually was, meaning there were a lot of temperature spikes up and down 21-Nov-18 11:44 PM yeah 21-Nov-18 11:44 PM i didnt notice until a while later 21-Nov-18 11:44 PM and in order to diagnose for sure i needed to get an external one 21-Nov-18 11:44 PM and then it was really clear 21-Nov-18 11:44 PM works so much better as is now but its still a budget printer. I have a ways to go before its actually good 21-Nov-18 11:45 PM Does cura plot temperature curves/pid? 21-Nov-18 11:45 PM if you want to build up UHV compatible PCB, you need to get rid of the epoxy of the package, right? 21-Nov-18 11:46 PM nope @AdamMcCombs but im using this with an sd card anyway 21-Nov-18 11:46 PM octoprint does provide curves, and thats where im planning to shift to eventually 21-Nov-18 11:46 PM @N00N no absolutely not, if anything that would make it worse 21-Nov-18 11:47 PM @hedgebert y? 21-Nov-18 11:47 PM any insulator is usually going to be helpful in high-voltage things, what you need to worry about is non-uniformities 21-Nov-18 11:47 PM ah, i mean "Ultra High Vacuum" 21-Nov-18 11:47 PM OH 21-Nov-18 11:47 PM not "Ultra High Voltage" 21-Nov-18 11:47 PM Ultra high voltage or vacuum? 21-Nov-18 11:47 PM OH OH OH 21-Nov-18 11:47 PM ok 21-Nov-18 11:47 PM yeah idk 21-Nov-18 11:47 PM on topic!11 21-Nov-18 11:47 PM epoxy could leech chemicals i guess? 21-Nov-18 11:47 PM especially if hot and in high vacuum? 21-Nov-18 11:48 PM I mean how far into uhv do you want to go? 21-Nov-18 11:48 PM yeah, so my question is, what is the best way to do it, using chips and bond them on ceramics substrate? 21-Nov-18 11:48 PM uh 21-Nov-18 11:48 PM 10^{-11} mbar 21-Nov-18 11:48 PM you can sometimes buy uncapped dies, yeah 21-Nov-18 11:48 PM Hm 21-Nov-18 11:48 PM and with a wirebonder thats doable 21-Nov-18 11:48 PM 10^{-10} would be ok, but the lower the better 21-Nov-18 11:49 PM but, you might have more success buying the chips off the shelf, then etch-and-polishing them? 21-Nov-18 11:49 PM Can you just use a multi pin feedthrough? 21-Nov-18 11:49 PM nitric isnt too too hard to make on-site 21-Nov-18 11:49 PM @hedgeberg yeah, that's what i mean 21-Nov-18 11:49 PM Problem is going to be bake out to get to that vacuum 21-Nov-18 11:49 PM yep, but the chips survive that 21-Nov-18 11:50 PM got DI water, urea, and uh... 21-Nov-18 11:50 PM shoot whats it called 21-Nov-18 11:50 PM oh right! 21-Nov-18 11:50 PM ammonia! 21-Nov-18 11:50 PM 200 Deg Celsius is no prob for normal semiconductor foo 21-Nov-18 11:50 PM (for hours) 21-Nov-18 11:51 PM -11 at 200c is cutting it close 21-Nov-18 11:51 PM urea + ammonia produces NO2 in gaseous form. Bubble that into chilled DI water in a lightly pressurized space (read: balloon) and you can get HNO2 + HNO3 in solution 21-Nov-18 11:51 PM @hedgeberg no problem, i have HNO3 on site 21-Nov-18 11:51 PM oh 21-Nov-18 11:51 PM man 21-Nov-18 11:51 PM then what the heck is the point of having knowledge of homebrewing things 21-Nov-18 11:52 PM i want to know if there are alternatives 21-Nov-18 11:52 PM not really? epoxy doesnt like high temperatures 21-Nov-18 11:52 PM around 150C youll start to see it degrade 21-Nov-18 11:52 PM like i dunno using special pottant 21-Nov-18 11:52 PM and then it becomes powdery and that might even worse 21-Nov-18 11:52 PM i mean decapsulated chips 21-Nov-18 11:52 PM or which were delivered as a die 21-Nov-18 11:53 PM what kind of chips? 21-Nov-18 11:53 PM are we talking discrete component's? or do you want to put a uC in there? 21-Nov-18 11:53 PM i want a uC/FPGA there 21-Nov-18 11:54 PM What kind of solder were you looking at? 21-Nov-18 11:54 PM and a couple of analog stuff for microwave generation 21-Nov-18 11:54 PM @AdamMcCombs bonding 21-Nov-18 11:54 PM @AdamMcCombs but normal solder is okay too 21-Nov-18 11:54 PM (the lead free) 21-Nov-18 11:55 PM @AdamMcCombs even lead solder would be fine, especially if you cover in conformal coating and then anneal at 120C 21-Nov-18 11:55 PM no, lead solder evaporates 21-Nov-18 11:55 PM the lead is the problem for UHV 21-Nov-18 11:55 PM read: conformal coating 21-Nov-18 11:55 PM ok 21-Nov-18 11:55 PM Conformal won't work in uhv 21-Nov-18 11:55 PM yeah 21-Nov-18 11:56 PM the conformal would degrade in UHV? 21-Nov-18 11:56 PM to leaky and itself is a problem 21-Nov-18 11:56 PM Yeah 21-Nov-18 11:56 PM :/ 21-Nov-18 11:56 PM Maybe making connections on top with deposited aluminium? 21-Nov-18 11:57 PM i cant imagine that would hold up well 21-Nov-18 11:57 PM Pretty much everything that's not ceramic or metal is going to have problems to various degrees 21-Nov-18 11:57 PM i mean it would be cool if there is an UHV compatible coating (coat the complete PCB, voila) but i think that's kinda impossible 21-Nov-18 11:58 PM Is there a reason you can't do a feedthrough? 21-Nov-18 11:58 PM yes, to complex 21-Nov-18 11:58 PM I'm using blue painters tape as a print surface. It's cheap 21-Nov-18 11:58 PM that's the answer! 21-Nov-18 11:58 PM blue painters tape in UHV 21-Nov-18 11:58 PM Morning @Leona 21-Nov-18 11:58 PM pffft 21-Nov-18 11:58 PM Lol 21-Nov-18 11:59 PM ^^ morning~ 21-Nov-18 11:59 PM hi Leona 21-Nov-18 11:59 PM but now: coffee time \o/ 21-Nov-18 11:59 PM WAIT! 21-Nov-18 11:59 PM If you need it in there so badly 21-Nov-18 11:59 PM why not make a special container with a feedthrough? 21-Nov-18 11:59 PM that way you can have it right beside the experiment you want to run. 21-Nov-18 11:59 PM You can go now. 22-Nov-18 12:01 AM i mean I will say if its not a sensor there really isnt a reason to want it inside the chamber, is there? 22-Nov-18 12:01 AM Dunno, I just provide solutions, not ask questions...I'm an igor 22-Nov-18 12:01 AM and im an engineer 22-Nov-18 12:02 AM Good for you, I'm just a technician. 22-Nov-18 12:02 AM its my job to point out that the constraint/request is stupid in order for me to not have to solve the hard problem 22-Nov-18 12:02 AM no no im not bragging, im saying thats a bad thing 22-Nov-18 12:02 AM (Not intended as being offended, don't worry, I got your meaning) 22-Nov-18 12:03 AM ... But maybe encasing the PCB in glass is an option… 22-Nov-18 12:03 AM yawn good morning everyone! 22-Nov-18 12:03 AM Still, if you had a big enough vacuum chamber, I could imaine the need for having the circuit close to the sensor, instead of super long feedthrough cables. 22-Nov-18 12:03 AM Morning, Giga! 22-Nov-18 12:04 AM The in vacuum uhv fpga stuff I have seen was all built on custom silicon and opto coupled through thousands of fibers 22-Nov-18 12:04 AM would be easier to make it in metal instead of glass encasing. 22-Nov-18 12:04 AM i cant imagine making a pcb inside of metal would be terribly easy or fun. 22-Nov-18 12:05 AM No, no, making a metal capsule, with feedthroughs. You could even stick a battery inside, and have a wireless sensor recorder 22-Nov-18 12:05 AM and you could feasibly make one end with metal gaskets, so it is compatible with UHV 22-Nov-18 12:05 AM Now I kinda want to make that...I need broken IGM400 gauges... 22-Nov-18 12:05 AM (to repurpose the feedthroughs) 22-Nov-18 12:09 AM you know what I wish openscad had? 22-Nov-18 12:09 AM polygons as objects 22-Nov-18 12:10 AM If I said yes, you would flip out 22-Nov-18 12:10 AM which you could do operations on 22-Nov-18 12:10 AM fusion 360 22-Nov-18 12:10 AM ahem 22-Nov-18 12:10 AM XDDDD 22-Nov-18 12:10 AM yeah ok get me a local executable and we'll talk 22-Nov-18 12:10 AM i need to make something very clear: i am regressing 22-Nov-18 12:10 AM i am moving backwards in tech time 22-Nov-18 12:11 AM Ah 22-Nov-18 12:11 AM !kcul doog 22-Nov-18 12:12 AM the more i do involving tech, the more I discover that modern things are bad. I really, really do not like running software in the cloud. 22-Nov-18 12:12 AM im at the point now where if i cant run it offline im probably not going to use it. 22-Nov-18 12:13 AM You'll arrive at the IBM mainframes, and realise even they were bad. 22-Nov-18 12:14 AM I totally understand 22-Nov-18 12:14 AM I mean solidworks and inventor both can run airgaped... 22-Nov-18 12:14 AM But I don't think that's what you want 22-Nov-18 12:16 AM I'd rather not pirate things, and it needs to be linux friendly 22-Nov-18 12:16 AM so 22-Nov-18 12:16 AM As I said... 22-Nov-18 12:16 AM actually, I wonder if i can get a solidworks license via mit... 22-Nov-18 12:16 AM shrugs 22-Nov-18 12:16 AM I know they give out inventor 22-Nov-18 12:17 AM I've had some success with freecad 22-Nov-18 12:17 AM But you notice that their version number still starts with 0.1 22-Nov-18 12:56 AM I'm not sure what it says about me that I still can't run my sputter coater without turning the lights off first 22-Nov-18 12:56 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181122_005359-759AD.jpg 22-Nov-18 12:56 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181122_005244-82FB7.jpg 22-Nov-18 12:56 AM Also I'm finding that boron nitride nano tubes are more sensitive to plasma than I originally thought 22-Nov-18 01:00 AM We all do the same...it's something on the glow 22-Nov-18 01:00 AM i never used modules in openscad before 22-Nov-18 01:00 AM and theyre great? 22-Nov-18 01:00 AM now that im figuring out the syntax its making a lot more sense a lot faster 22-Nov-18 01:00 AM also @AdamMcCombs i will sit around watching my printer for 45 minutes, fascinated by the fact that its constructing something in front of me. 22-Nov-18 01:00 AM its the dweeb effect 22-Nov-18 01:03 AM dweeb? 22-Nov-18 01:03 AM we can't help but be amazed by the things we're working on 22-Nov-18 01:03 AM ?? what, you dont know what it means? 22-Nov-18 01:03 AM just looked it up 22-Nov-18 01:03 AM no, didn't know the word (english is my third language) 22-Nov-18 01:04 AM i mean it in an endearing way, fwiw 22-Nov-18 01:04 AM whats your first and second? 22-Nov-18 01:04 AM Spanish and Catalan 22-Nov-18 01:04 AM because if english is your 3rd then damn 22-Nov-18 01:04 AM oh, neat 22-Nov-18 01:04 AM you might actually be the first person I've ever met that speaks catalan? 22-Nov-18 01:04 AM Also catalan is similar to french, so I can read documents on it. (not understand a word of it spoken, though) 22-Nov-18 01:05 AM all I speak are english and a bit of mandarin 22-Nov-18 01:05 AM and my mandarin is /bad/ 22-Nov-18 01:05 AM Better than my french for sure. 22-Nov-18 01:05 AM I speak English and JEOL basic... 22-Nov-18 01:05 AM press x to doubt 22-Nov-18 01:06 AM @AdamMcCombs XDDDDDDDDDDDDDDDDDDDDDDDDDDD 22-Nov-18 01:06 AM So basically English and a some poor translation of Japanese 22-Nov-18 01:06 AM To delete a file on a 16 bit JEOL system is kinda funny 22-Nov-18 01:07 AM I wish I could speak G-Code, but nah 22-Nov-18 01:07 AM why is it funny? exemplify 22-Nov-18 01:08 AM You think the terminal command would be del or delete or rm or something 22-Nov-18 01:08 AM But no 22-Nov-18 01:08 AM It's kill 22-Nov-18 01:08 AM BAHAHAHAHA 22-Nov-18 01:08 AM Who does that? 22-Nov-18 01:08 AM PLEASE, NAME A FILE BILL, then delete it. 22-Nov-18 01:08 AM xD 22-Nov-18 01:08 AM Lol 22-Nov-18 01:08 AM I figured out why though 22-Nov-18 01:08 AM It's who did the translation 22-Nov-18 01:09 AM XDDD 22-Nov-18 01:09 AM It was the wife of a us general who live 3 train stops away from the JEOL factory 22-Nov-18 01:10 AM /is supposed to be machininig stainless/ 22-Nov-18 01:10 AM She was a native English speaker 22-Nov-18 01:10 AM But not by any means an engineer 22-Nov-18 01:10 AM So jeol has a bunch of nonsense acronyms and terms that just barely make sense 22-Nov-18 01:10 AM And it was all her 22-Nov-18 01:11 AM That's a fun story 22-Nov-18 01:12 AM So the thing that turns a TEM into a SEM is called a ASID 22-Nov-18 01:12 AM Most manufacturers call it the STEM unit 22-Nov-18 01:12 AM For scanning transmission electron microscope 22-Nov-18 01:12 AM But jeol called it asid 22-Nov-18 01:12 AM For automated scanning imaging device 22-Nov-18 01:12 AM There's nothing automated about it 22-Nov-18 01:12 AM Literally it's all knobs 22-Nov-18 01:12 AM It's better than ISI though 22-Nov-18 01:12 AM They just left like half the stuff in Japanese 22-Nov-18 01:16 AM and by now everyone has gotten used to the weird commands so changing them to "proper english" would just cause more confusion? 22-Nov-18 01:16 AM ah, technical debt 22-Nov-18 01:16 AM our old friend 22-Nov-18 01:17 AM No they built the next gen systems on os2 22-Nov-18 01:17 AM And then never did that again 22-Nov-18 01:17 AM Ask any microscopist about a JEOL 1210 and they will either not know what it is because it only was around for 2 years (with 3 major revisions) or curse it out 22-Nov-18 01:17 AM The 1200 Mrk II was made for 8 years without major revision and still sells for north of 130k USD today 22-Nov-18 01:17 AM People pay to get rid of 1210s 22-Nov-18 01:17 AM I actually turned one into a movie prop 22-Nov-18 01:22 AM @Nixie yeah, i thought about containers first, but the feedthrough would be quite complex 22-Nov-18 01:22 AM if i could make a ceramics pcb with non-leaky vias or something like that 22-Nov-18 01:22 AM as the "feedthrough" i mean 22-Nov-18 01:26 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20181122_102601-B28F9.jpg 22-Nov-18 01:26 AM What's the application? 22-Nov-18 01:26 AM About to make a copy of this. 22-Nov-18 01:26 AM @N00N we were talking prevoously tonrepurpose existing feedthroughs from broken IGM 400 gauges. 22-Nov-18 01:28 AM @AdamMcCombs ion clocks 22-Nov-18 01:28 AM @Nixie ah ok, hmmm IGM 400 you say 22-Nov-18 01:29 AM How many feedthroughs is that? 22-Nov-18 01:30 AM for my application? 100s 22-Nov-18 01:31 AM Like what? 4 or 5 hundred? 22-Nov-18 01:31 AM yeah 22-Nov-18 01:31 AM 100-1000 22-Nov-18 01:32 AM I might still go with feedthroughs 22-Nov-18 01:32 AM Especially if you need to run uhv 22-Nov-18 01:32 AM 11 is just so hard 22-Nov-18 01:32 AM yeah, but i'm talking about microwave stuff too (BTW) 22-Nov-18 01:32 AM Ugh 22-Nov-18 01:33 AM so no long wires or stuff like that 22-Nov-18 01:33 AM So solder is pretty much out 22-Nov-18 01:33 AM Make sure you use ceramic that isn't pourus 22-Nov-18 01:34 AM and that's y i'm currently thinking the PCB/Breakout Interposer/Board whatever made of ceramics is the way to go 22-Nov-18 01:34 AM yes 22-Nov-18 01:34 AM Ensure good thermal couplings and remember no convection cooling... 22-Nov-18 01:34 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_from_2018-11-22_04-34-33-671F2.png 22-Nov-18 01:34 AM ceramics is for "distant" pcb 22-Nov-18 01:34 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_from_2018-11-22_04-34-59-4C3DC.png 22-Nov-18 01:34 AM thats starting to look like something 22-Nov-18 01:34 AM only took me forever 22-Nov-18 01:34 AM hate having to relearn things, but I should actually be done with this weird geographic mess soon 22-Nov-18 01:35 AM and the near electrodes substrate is sapphire 22-Nov-18 01:35 AM so maybe Al2O3 ceramics (alumina) and Al2O3 crystal (sapphire) 22-Nov-18 01:35 AM okayish for high frequency application (lost tangent) and an okayish thermal conductor 22-Nov-18 01:36 AM Yeah it during bake out is going to be killer 22-Nov-18 01:36 AM Def no epoxy 22-Nov-18 01:36 AM yep 22-Nov-18 01:36 AM That should say ir 22-Nov-18 01:36 AM Maybe differentially pump if you can 22-Nov-18 01:36 AM Yeah differental pumping on a calble bundle should get you an extra decade 22-Nov-18 01:36 AM Or a cold shield 22-Nov-18 01:43 AM morning @qualia, how was the late night nap? 22-Nov-18 01:43 AM Actually can the electronics be cold? 22-Nov-18 01:44 AM @AdamMcCombs what are you thinking? pump in coolant? 22-Nov-18 01:44 AM thats the only possible way to cool something like that in a vacuum, isnt it? 22-Nov-18 01:44 AM using the electronics as a cooling finger (cryopump style)? 22-Nov-18 01:45 AM Just conductively couple the electronics to one 22-Nov-18 01:45 AM because that feels like a lot of complication for a minimal benefit? 22-Nov-18 01:45 AM Outgassing curves start to make a lot of sense 22-Nov-18 01:45 AM good time to ask what exactly youre trying to do here @N00N 22-Nov-18 01:46 AM And cryo in vacuum is common 22-Nov-18 01:46 AM because I just realized I dont actually know 22-Nov-18 01:46 AM it will be cooled down, but only to app. 77K 22-Nov-18 01:46 AM @hedgeberg ion clock stuff 22-Nov-18 01:46 AM oh, neat 22-Nov-18 01:46 AM Ln2 feedthroughs with a phase separator work great 22-Nov-18 01:46 AM but then why an FPGA? 22-Nov-18 01:46 AM why internally? can't route the sensor's signal out of the chamber? 22-Nov-18 01:46 AM controlling the trap 22-Nov-18 01:46 AM to much feedtroughs (IMHO) 22-Nov-18 01:47 AM @hedgeberg meow! unexpected and extremely strange but very restful 22-Nov-18 01:47 AM Like I feel like there must be a better way to do this, especially if youre only pumping in a few signals 22-Nov-18 01:47 AM Few hundred 22-Nov-18 01:47 AM why do you need a few hundred? 22-Nov-18 01:47 AM stabilisation and stuff like that 22-Nov-18 01:47 AM are you doing freaking 3d-beamforming inside of the chamber? 22-Nov-18 01:48 AM Yeah I think cryo is your best bet 22-Nov-18 01:48 AM squints 22-Nov-18 01:48 AM no, it's more like an ion coulomb crystal 22-Nov-18 01:48 AM why not use optical viewports and keep the electronics outside of the critical region 22-Nov-18 01:48 AM this may be getting past my level of physics chops, admittedly 22-Nov-18 01:48 AM in.. terrestrial gravity? 22-Nov-18 01:48 AM because in need the electronics (RF/Microwave) inside the trap 22-Nov-18 01:48 AM @qualia yes 22-Nov-18 01:49 AM ok, can you describe the setup at least partially? like, what exactly are the active endpoints of your circuit? 22-Nov-18 01:49 AM i guess you could say, what are the analog frontends here? 22-Nov-18 01:50 AM mixers, PA & DAC 22-Nov-18 01:50 AM no not in that sense 22-Nov-18 01:50 AM i guess im thinking frontends more in a cross-domain sense 22-Nov-18 01:50 AM sensors/stimulators 22-Nov-18 01:51 AM ok, electrodes feed by the amplifier behind the mixers 22-Nov-18 01:51 AM (in between switches and power dividers/couplers) 22-Nov-18 01:51 AM how many electrodes are there attached to the OUT? 22-Nov-18 01:51 AM 100-1000 22-Nov-18 01:51 AM (Object Under Test, since I assume its not quite a device) 22-Nov-18 01:51 AM I cannot possibly imagine what creates the need for 100-1000 interfaces, mind cueing me in just a little? 22-Nov-18 01:53 AM the formation of the control fields 22-Nov-18 01:53 AM so, do you need to construct an extremely specific 3d control field? 22-Nov-18 01:54 AM yeah, kind of, exactly ... more 2D or 2.5D-ish 22-Nov-18 01:54 AM but yeah 22-Nov-18 01:54 AM what is the field being used for? 22-Nov-18 01:54 AM controling the state of the ion crystal 22-Nov-18 01:54 AM i need to google ion crystal rq 22-Nov-18 01:54 AM ok 22-Nov-18 01:55 AM yeah this is not something that google wants to help with 22-Nov-18 01:55 AM The other day it took me 2h to cut the same piece with a dull blade, any guesses with the new M42 blade? 22-Nov-18 01:55 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20181122_105440-DC0BE.jpg 22-Nov-18 01:55 AM "Ion Coulomb Crystal" to be more specific 22-Nov-18 01:55 AM ICC for short 22-Nov-18 01:56 AM oh, I see 22-Nov-18 01:56 AM @N00N I want to do exoerimebts on making my own ceramic chip carriers, that might be of help 22-Nov-18 01:56 AM ok 22-Nov-18 01:56 AM so this is for what the literature is calling a penning trap? 22-Nov-18 01:56 AM @hedgeberg https://arxiv.org/pdf/1411.4945.pdf illustrive paper 22-Nov-18 01:56 AM already looking at it 22-Nov-18 01:57 AM a penning trap is one sort of trap 22-Nov-18 01:57 AM @Nixie yeah, that would be helpful 22-Nov-18 01:57 AM so what, you need a static electric field for each atom? 22-Nov-18 01:57 AM no that doesnt make any sense 22-Nov-18 01:57 AM im confused by the physics here 22-Nov-18 01:58 AM Might end making a special miniature oven just for baking that out, so not to force the semicon oven, but it is definitely in the near future. 22-Nov-18 01:58 AM no, i need "an" RF-ish (< 100MHz) "global" field for the trap itself 22-Nov-18 01:58 AM sure 22-Nov-18 01:58 AM then i need 100s of microwave fields (adressable) to control the states 22-Nov-18 01:58 AM and then i need 100s of "low frequency" fields to compensate a few side effects 22-Nov-18 01:59 AM But do you have the bare chip that does the adressing? 22-Nov-18 01:59 AM Sorry for going quite. I'm in clearance is clearance mode with a very expensive detector 22-Nov-18 01:59 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181122_015709-19E0F.jpg 22-Nov-18 01:59 AM I have to wonder if you could achieve this all just as well using a cavity resonator 22-Nov-18 01:59 AM XDDD 22-Nov-18 01:59 AM don't crash it! 22-Nov-18 02:00 AM construct an overmoded n-point cavity resonator and do field-forming 22-Nov-18 02:00 AM this conversation is going waaaay out of my league. 22-Nov-18 02:00 AM XDDD 22-Nov-18 02:00 AM @hedgeberg well sounds complicated to me 22-Nov-18 02:00 AM that way, you'd go from 100s of electrodes to like, 10? 22-Nov-18 02:01 AM Fun part is I don't have a chamber camera for this scope yet 22-Nov-18 02:01 AM but the cavity is static 22-Nov-18 02:01 AM yeah 22-Nov-18 02:01 AM @Nixie Oh good, I way beginning to think that it's just me 22-Nov-18 02:01 AM a static cavity resonator can have many modes 22-Nov-18 02:01 AM hence "overmoded" 22-Nov-18 02:01 AM i kno, but i guess it's not enough 22-Nov-18 02:02 AM we're entering the territory of mad science @Nixie 22-Nov-18 02:02 AM @AdamMcCombs what is that? 22-Nov-18 02:03 AM basically, choose a set of modes such that you stimulate at a set of resonant frequencies, and by applying differently phased signals along the walls of the cavity you can change the spatial distribution of the fields? 22-Nov-18 02:03 AM @Leona I'm making my own semiconductors at home, don't know whatcha talking 'bout. 22-Nov-18 02:03 AM hm, I wonder if you could do this all using a couple of well-placed inductors... 22-Nov-18 02:03 AM I need to find my copy of pozar 22-Nov-18 02:04 AM you mean the microwave book? 22-Nov-18 02:04 AM yup 22-Nov-18 02:04 AM "microwave engineering"? 22-Nov-18 02:04 AM yup, 4th edition 22-Nov-18 02:04 AM ok, have it on my desk %) 22-Nov-18 02:04 AM ❤ pozar 22-Nov-18 02:05 AM That's the stage on my sem less than a mm from my semiconductor backscatter detector 22-Nov-18 02:05 AM i havent done microwave stuff in a long time so my theory is a bit weak 22-Nov-18 02:05 AM but I think you could achieve an almost perfect field distribution 22-Nov-18 02:05 AM question is, how's your signal processing chops? 22-Nov-18 02:05 AM @N00N is the idea here that each of these electrodes would effectively be monopoles? 22-Nov-18 02:05 AM Wish we had a whiteboard so you could draw the field shapes you needed 22-Nov-18 02:05 AM I really shouldnt be trying to spitball RF stuff at 5 AM 22-Nov-18 02:09 AM Is there a reason that a linear paul trap won't work beyond need for crazy tolerance? 22-Nov-18 02:09 AM @hedgeberg 22-Nov-18 02:09 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-50C26.jpg 22-Nov-18 02:09 AM yup there it is 22-Nov-18 02:10 AM I don't know what the tail end of the performance curve for those looks like 22-Nov-18 02:10 AM pozar is bae @N00N 22-Nov-18 02:10 AM anyway @AdamMcCombs i think the issue is that they want to trap several ions 22-Nov-18 02:10 AM making the fields a lot more complex 22-Nov-18 02:11 AM Yep, it’s near field stuff 22-Nov-18 02:11 AM Yeah I guess you would only have several positions you could tune for 22-Nov-18 02:11 AM because you cant exactly get 4 electrodes per atom in a space where the separation between ions is on the scale of bond-lengths 22-Nov-18 02:11 AM slamming stages/specimens in the expensive sensors sucks i guess @AdamMcCombs 22-Nov-18 02:12 AM @N00N you ever heard of time reversal? 22-Nov-18 02:12 AM @hedgeberg yeah, y? 22-Nov-18 02:12 AM no, i don't need exactly one quadrupol trap per ion, the number of quadrupol trap is lesser then the number of trapped ions 22-Nov-18 02:12 AM but i need the control electrodes in the scale of the ion distances, that's true 22-Nov-18 02:12 AM that's what the sapphire substrated electrodes are needed for 22-Nov-18 02:14 AM yeah 22-Nov-18 02:14 AM (structured with mikrometer resolution) 22-Nov-18 02:14 AM im being to understand your dilemna much better 22-Nov-18 02:14 AM I just feel like theere needs to be another way 22-Nov-18 02:15 AM yeah, would be cool if there is an alternative 22-Nov-18 02:15 AM the electrode structuring itself is not the problem (EBL) 22-Nov-18 02:16 AM yeah its all the signals that you need in order to drive the electrodes effectively 22-Nov-18 02:16 AM yep 22-Nov-18 02:17 AM are each of the electrodes 100% totally independent of each other? 22-Nov-18 02:17 AM or are there situations where, like 22-Nov-18 02:17 AM electrodes 7, 20, and 400 are all in-phase 22-Nov-18 02:18 AM wellll it can be optimized to make the connection/switch matrix sparse but in general more independece -> better 22-Nov-18 02:18 AM yeah 22-Nov-18 02:18 AM whats your budget on this project? is this a work project or a home project? 22-Nov-18 02:18 AM i think i need a copy of that microwave book 22-Nov-18 02:19 AM will be a trade off figured out by experimenting 22-Nov-18 02:19 AM @qualia i have a pdf on my ipad 22-Nov-18 02:19 AM can send 22-Nov-18 02:19 AM /me shovels dollars into amzn 22-Nov-18 02:19 AM i need physical books tbch 22-Nov-18 02:19 AM rip 22-Nov-18 02:19 AM i am not cursed with that particular affliction 22-Nov-18 02:19 AM (or an e-reader that does pdfs really really well) 22-Nov-18 02:20 AM @hedgeberg it's kinda home project 22-Nov-18 02:20 AM anyway though fair warning, its not exactly light afternoon reading 22-Nov-18 02:20 AM is it a dense sea of latex equations 22-Nov-18 02:20 AM or 22-Nov-18 02:20 AM i spent almost a month in undergrad trying to get a comprehensive understanding of the first 60 pages 22-Nov-18 02:20 AM its a lot of things 22-Nov-18 02:20 AM that sounds wonderful 22-Nov-18 02:21 AM a lot of that and a lot of other stuff. The thing that makes it great is that they walk through all the derivations 22-Nov-18 02:21 AM oo 22-Nov-18 02:21 AM also afaik its the only book that actually gives a good explanation of all the mechanics of Smith charts 22-Nov-18 02:21 AM its the singular Microwave Bible according to PhD students 22-Nov-18 02:21 AM everyone and their dog has a copy from what I've seen 22-Nov-18 02:22 AM and i'm more a cat person i guess 22-Nov-18 02:22 AM ?cat 22-Nov-18 02:22 AM Found one! 22-Nov-18 02:22 AM heck yeah 22-Nov-18 02:23 AM I'll post photos once I'm done with my beam alignment, but I think I'm literally looking at what causes cancer right now 22-Nov-18 02:23 AM but i can't let my cats in my secret lab 22-Nov-18 02:23 AM uh 22-Nov-18 02:23 AM there are a lot of things that cause cancer, but arent necessarily dangerous if powered off 22-Nov-18 02:23 AM are you looking at an unprotected e-beam? 22-Nov-18 02:24 AM Nano tubes are not one of those things 22-Nov-18 02:24 AM because then yes, that would be causing cancer and also some OSHA violations 22-Nov-18 02:24 AM oh christ 22-Nov-18 02:24 AM @AdamMcCombs what's the cancer thing you're talking about? 22-Nov-18 02:24 AM uh... dont... breathe??? 22-Nov-18 02:24 AM jesus dude 22-Nov-18 02:25 AM I'm trained in imaging abspestos so I'm following those sops 22-Nov-18 02:25 AM are u talking about xrays? or fibers? 22-Nov-18 02:25 AM fibers 22-Nov-18 02:25 AM ah ok 22-Nov-18 02:25 AM he's saying there are carbon nanotubes in his chamber 22-Nov-18 02:25 AM I'm imagining nanotubes in my sem right now 22-Nov-18 02:26 AM hmm, cool 22-Nov-18 02:26 AM Not carbon 22-Nov-18 02:26 AM Boron nitride 22-Nov-18 02:26 AM In bulk 22-Nov-18 02:26 AM ooooooooh love me some boro nitride 22-Nov-18 02:26 AM i didnt know it formed nanotubes! 22-Nov-18 02:26 AM I only know boro nitride b/c of hexa-BN 22-Nov-18 02:27 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181122_022730-FD11F.jpg 22-Nov-18 02:27 AM do you guys are experienced in "biological specimen" prep? 22-Nov-18 02:28 AM Regretfully yes 22-Nov-18 02:28 AM Tem or sem 22-Nov-18 02:28 AM I'm trying to take my scope to 100kx right now 22-Nov-18 02:29 AM i buyed a used book about that but haven't read it yet 22-Nov-18 02:29 AM but it would be interesting to make bio stuff pics 22-Nov-18 02:32 AM Wanna get into histo with that? 22-Nov-18 02:32 AM but i know, it's not that easy to preserve good shaped cells 22-Nov-18 02:32 AM @Leona no, just looking around 22-Nov-18 02:34 AM Yeah no look at what the Allen Institute is doing 22-Nov-18 02:35 AM what are they doing? tearing brains apart? 22-Nov-18 02:35 AM https://youtu.be/LO8xCLBv6j0 22-Nov-18 02:36 AM yeah ok 22-Nov-18 02:36 AM These are some of the Teams that I help keep running, and soon will be working on development for what's in effect the v2 scopes 22-Nov-18 02:37 AM so they throw away their old scopes? jk 22-Nov-18 02:37 AM No Princton just wants in on it... 22-Nov-18 02:37 AM btw, how good are those old zeiss EM902? 22-Nov-18 02:37 AM (i want a TEM) :3 22-Nov-18 02:37 AM @AdamMcCombs any recommendations for "entry level" TEM? 22-Nov-18 02:39 AM Get a Philips em400 or better yet em420 22-Nov-18 02:39 AM hmm, ok 22-Nov-18 02:39 AM There's no such thing as a entry level tem 22-Nov-18 02:39 AM Get a sem first, learn how to work on it, then very carefully think about how much you hate yourself 22-Nov-18 02:41 AM ok, implies operating an TEM is PITA 22-Nov-18 02:41 AM it's like "that's your job now"? 22-Nov-18 02:41 AM everything tem is a pita 22-Nov-18 02:41 AM isit like 40h/w to keep it running? 22-Nov-18 02:41 AM or 4h/w? 22-Nov-18 02:41 AM without external maintenance service of course 22-Nov-18 02:42 AM Like 2 months of 50 hour weeks to get a beam sometimes 22-Nov-18 02:42 AM ew 22-Nov-18 02:42 AM You don't get scopes in good shape for free 22-Nov-18 02:43 AM ok like 10-50 times harder then operating/maintaining a SEM? 22-Nov-18 02:43 AM It takes like 2 normal weeks tops to bring a seem up 22-Nov-18 02:43 AM *sem 22-Nov-18 02:43 AM If you get a tem in good shape probably only a month of work 22-Nov-18 02:44 AM and then? 22-Nov-18 02:44 AM If you know what you are doing 22-Nov-18 02:44 AM With that particular manufacturer 22-Nov-18 02:44 AM i mean how intense is the maintenence? 22-Nov-18 02:45 AM Uh 22-Nov-18 02:45 AM is it like "once it is running, never shut it down" 22-Nov-18 02:45 AM Yeah that 22-Nov-18 02:45 AM and then like "1h per day caring"? 22-Nov-18 02:46 AM Uh 22-Nov-18 02:46 AM and sometimes it f*cks up and you've like 2 weeks of fun? 22-Nov-18 02:46 AM Some scopes only need maintenance bonce a year 22-Nov-18 02:46 AM And others more so 22-Nov-18 02:46 AM ok, i mean "cheap"/old ones like the philips you recommended 22-Nov-18 02:46 AM or is it a individual thing 22-Nov-18 02:46 AM an individual thing like with people, some need more hugs than others 22-Nov-18 02:46 AM ok, maybe it's not the best idea 22-Nov-18 02:48 AM Yup 22-Nov-18 02:48 AM They hate being moved 22-Nov-18 02:49 AM like trees 22-Nov-18 02:49 AM Any chance you have a mic? 22-Nov-18 02:49 AM I'm trying to run my seem and chat at the same time and it's not working... 22-Nov-18 02:50 AM you mean the chance to buy a TEM? sometimes they're on ebay et al 22-Nov-18 02:50 AM i bid on a TEM once (3k or stomething like that) but the min price was something like 250k 22-Nov-18 02:51 AM What scope? 22-Nov-18 02:51 AM Philips cm30? 22-Nov-18 02:54 AM Tecnai F20 22-Nov-18 02:54 AM iirc 22-Nov-18 02:54 AM or no, it was a Tecnai G20 Spirit 22-Nov-18 02:54 AM Oh yeah no that what that scope costs 22-Nov-18 02:54 AM That's a good deal actually 22-Nov-18 02:55 AM yep, but sometimes such stuff goes way cheaper 22-Nov-18 02:55 AM like they need the space instant and stuff like that 22-Nov-18 02:56 AM Old stuff does 22-Nov-18 02:56 AM Tecnai doesn't 22-Nov-18 02:56 AM ok, openscad's 3d rotate algorithm is stupid 22-Nov-18 02:57 AM Can we move this to general voice chat? 22-Nov-18 02:57 AM sorry ill stop interjecting 22-Nov-18 02:57 AM is quiet now 22-Nov-18 02:58 AM No I'm just trying to run my sem at the same time... 22-Nov-18 02:58 AM And I only have so many hands 22-Nov-18 02:58 AM i'm def down for voice chats sometime fwiw 22-Nov-18 02:58 AM even if it's just idling 22-Nov-18 02:59 AM Cool I'm there 22-Nov-18 02:59 AM Any one else want to join? 22-Nov-18 03:04 AM oh brt actually 22-Nov-18 03:05 AM hey anyone want me to post a sin rq 22-Nov-18 03:05 AM color("purple") protrusion([midway + base_poly_height/2, base_poly_width, slant_vertical_offset] + [0, -((1/sqrt(2)) * (slant_len - base_poly_height)), (1/sqrt(2)) * (slant_len - base_poly_height)], [-90, -45, -90], total_len/2); 22-Nov-18 03:05 AM I write sins, not good scad 22-Nov-18 03:05 AM now I have to add the inset holes, then get my real actual measurements from the printer and write those in, and im done 22-Nov-18 03:13 AM I'll join to listen mostly 22-Nov-18 03:15 AM i spent way too long on this and its getting light out 22-Nov-18 03:15 AM for those in the US, enjoy the holiday and try to forget its roots i guess? 22-Nov-18 03:16 AM I'd listen, if I wasn't in class... 22-Nov-18 03:17 AM or, dont forget, and use your rage as fuel to help fix things? 22-Nov-18 03:17 AM idk im rambling I need to go to bed 22-Nov-18 03:17 AM night all 22-Nov-18 03:17 AM o/ nini 22-Nov-18 03:17 AM Nightynighty 22-Nov-18 03:17 AM Noone else joining the voice channel? 22-Nov-18 03:27 AM I don't have a mic :/ 22-Nov-18 03:28 AM You can listen and talk in private 22-Nov-18 03:43 AM The urge to join is strong, but the will to listen to this course is stronger 22-Nov-18 03:44 AM what's the topic of your lecture? 22-Nov-18 03:44 AM It's mostly vacuum talk, and Adam giving a talk about how horrible TEMS and SEMS are to work with if you don't know much about them. 22-Nov-18 03:44 AM Dijkstra's Algorithm 22-Nov-18 03:44 AM what's that? 22-Nov-18 03:44 AM gesundheit 22-Nov-18 03:45 AM A greedy-algorithm to discover short paths in a net 22-Nov-18 03:45 AM traveling businessman problem? 22-Nov-18 03:45 AM No, not a roundtrip. Just point 2point paths 22-Nov-18 03:45 AM Network optimization then? 22-Nov-18 03:46 AM ah, ok 22-Nov-18 03:46 AM I just disconnected, I have to finish the stainless connector! 22-Nov-18 03:46 AM @Nixie I guess... 22-Nov-18 03:46 AM Could probably work pretty well for that. 22-Nov-18 03:47 AM @Nixie have fun! 22-Nov-18 03:47 AM I'm gonna buy a mic after uni, how sensitive is discord to feedback from the speakers? 22-Nov-18 03:47 AM in other words: Do I need only the mic or a headset? 22-Nov-18 03:54 AM Better than Skype at least 22-Nov-18 03:54 AM (Back when I last used Skype) 22-Nov-18 03:59 AM that dosen't say too much, because skype is [DELETED BY BOT] 22-Nov-18 04:00 AM ^^ 22-Nov-18 04:00 AM agrees 22-Nov-18 04:00 AM I have used a mic and headphones for years. But that's mostly bc my speakers sit behind me and would certainly annoy anyone I voice chatted with. 22-Nov-18 04:00 AM Previously I had my speakers sideways, and didn't use discord yet 22-Nov-18 04:08 AM I'll just get a mic 22-Nov-18 04:36 AM I bought this today. I’m sure it’s great for dissolving carpet rust stains but actually I don’t have any carpet rust stains 22-Nov-18 04:36 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-6B2A2.jpg 22-Nov-18 04:36 AM Note to self: order calcium gluconate 22-Nov-18 04:37 AM pls b careful 22-Nov-18 04:37 AM Yes 22-Nov-18 04:38 AM https://www.honeywell-hfacid.com/wp-content/uploads/2014/06/2734-Medical-Treatment-for-HF-Acid-Exposure_v7-WEB.pdf print this out and keep it somewhere 22-Nov-18 04:38 AM bring it with if you ever go to the hospital 22-Nov-18 04:38 AM At least it’s 1% and not 49% 22-Nov-18 04:38 AM oh that's not too frightening 22-Nov-18 04:40 AM We have 49% in our cleanroom and dedicated fume hoods and hexafluorine showers but I haven’t gone through the induction and paperwork to touch it yet 22-Nov-18 04:41 AM Post this to #resources too pls 22-Nov-18 04:57 AM @GigaSquirrel buy a headset, even cheap, it will be better by orders of magnitude. 22-Nov-18 05:00 AM @AdamMcCombs good night 22-Nov-18 05:20 AM @Nixie too late, just bought an ok-ish webcam 22-Nov-18 05:23 AM i do all of my voice stuff with speakers & a dynamic & a condenser microphone 22-Nov-18 05:23 AM discord's echo cancellation is pretty solid 22-Nov-18 05:24 AM great 22-Nov-18 05:40 AM Will you join us? 22-Nov-18 05:40 AM or you are going back to work? 22-Nov-18 05:42 AM I'm on my way home right now, might join you later 22-Nov-18 05:42 AM like ~20 min 22-Nov-18 05:43 AM We can wait a bit for you 22-Nov-18 05:43 AM GO; GO; GO! 22-Nov-18 05:44 AM yes, I'll wait for my train faster :P 22-Nov-18 05:44 AM Joined the server. 22-Nov-18 05:44 AM hello! 22-Nov-18 05:45 AM Hi! 22-Nov-18 05:50 AM where's the train? 22-Nov-18 05:50 AM all around me 22-Nov-18 05:50 AM one more stop and I'm there 22-Nov-18 05:53 AM Okay! I'll go to the lathe to finish the piece meanwhile you arrive, eat something and setup the camera, and we'll talk afterwards 22-Nov-18 05:53 AM yep :) 22-Nov-18 06:08 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181122_150714-810B4.jpg 22-Nov-18 06:08 AM Look at my twins! 22-Nov-18 06:09 AM very nice, KF40? 22-Nov-18 06:09 AM to iso adapter 22-Nov-18 06:14 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181122_151145-3A8B6.jpg 22-Nov-18 06:14 AM KF40 to 45mm ID O-ring retainers for the 45mmOD quartz glass tube. Now the oven is fully sealed and I can do true vacuum (not super vacuum, but reduced pressure) or inert atmospheres. 22-Nov-18 06:44 AM Re. Signal feedthrus for logic, etc. Don't know how hi vac you can go with this approach, issues with reactive plasma, etc., but consider using a flex pcb run thru a seal using epoxy or o ring/grease. With a bell jar your can just run it between the baseplate and gasket. I've run USB into my HV chamber this way. Also issues with vacuum compatibility for solder, polymers, are much less if your keep the stuff cool and away from plasma. If your really need e-10 etc., then live clean, pray, sacrifice goats, etc. But those long lists of approved materials, cleaning procedures, etc., that you can download from national labs are about playing it safe. I read that in the LIGO gravity observatory many banned materials such as aluminum castings, pc boards, soft solder are actually used, not always by prior approval. 22-Nov-18 06:47 AM At some point I plan to do some custom feedthrough tests with Hysol 1-C, which seems to be a reasonably commonly-used low-volatility vacuum epoxy 22-Nov-18 06:47 AM i like that it doesn't smell like anything at all at any point while mixing/curing, as you'd expect 22-Nov-18 06:47 AM (it's also pretty inexpensive) 22-Nov-18 06:50 AM For epoxy feedthrus I've had better luck with JB weld than Hysol-1C. The hysol is too thick, does not wet out and forms small leaks. But JB weld is metal filled, not actually conductive, but seems iffy for HV electrical insulation. 22-Nov-18 07:30 AM Really?...Hmmmmmm.... 22-Nov-18 07:40 AM Lots to catch up on here after sleep and travel 22-Nov-18 07:40 AM Sleeping is dangerous here. 22-Nov-18 07:43 AM @AdamMcCombs I am using Molflow+ for high vacuum simulation, which is the standard really in the accelerator physics community. Note that before I ran any simulations I hand calculated every aspect of my system prior so I know what to reasonably expect. I have the pumping station complete, and will be releasing details on twitter after my nonthermal plasma and thermal torch walkthroughs 22-Nov-18 07:43 AM For those considering levels at 10^-10, I would strongly urge you to thoroughly study UHV engineering. If you do even simple calculations you will see just how difficult it us to reach. Outgassing loads are absolutely critical. We are talking high temperature baking and pumping for upwards of a hundred hours depending on the system. Ion pumping is needed for this. Teflon is rated for in UHV, but not between atmosphere and vacuum. Most polymers are a no go, as well as many solders. There are specific UHV rated brazes to be used, and sealing must be UHV with proper ceramic- metallic bonds 22-Nov-18 07:43 AM I could write a massively large article tens of pages on this alone 22-Nov-18 07:43 AM Remember, at those levels, stuff behaves counterintuitively. Getting to 10^-7 is do able with good effort. Breaking 10^-8 is a big, big hurdle, and higher gets much harder 22-Nov-18 07:43 AM For example, at the facility I work at, we have a small test egun injector. Very short 2.75" conflat beamline, like a foot long. Single ceramic break and feedthrough for Faraday cup. Dual ion pumps. When we upgraded the Faraday cup, it took weeks of pumping and baking to get back to our default 10^-11 torr standby vacuum. Probably a week with the turbo, then several weeks with ion pumps. In addition to high voltage conditioning of the gun as well. 22-Nov-18 07:43 AM With any ceramics, baking also must be ramped up very slowly to prevent cracking from thermal shock. We also nitrogen purged when venting and changing the cup, minimizing exposure to atmosphere to as short of a time as possible 22-Nov-18 08:21 AM JB Weld is amazing. I think it’s great for everything and cheaper than torrseal or hysol 22-Nov-18 08:21 AM We had a weird issue with a PMT today where it turned out that a vacuum feedthrough into a steel vessel was sealed at high vacuum but it was a subtle light leak. 22-Nov-18 08:33 AM Jb weld is indeed great, I use it for a lot of stuff as well. It is suitable for high vacuum, but definitely not UHV levels 22-Nov-18 09:00 AM Vacuum shop friends can cycle from atmosphere to -11 in about 5 days, but that's with a massive igp and a cryo pump, after a 3 day bake out. Everytime they vent it though they need to run a very sensitive leak check. It's definitely not easy. Thus the idea to souround what you can in ln2, even stuff that you should be able to take to -9 no problem. 22-Nov-18 09:05 AM Yeah, cryo will get you there faster than ion for sure 22-Nov-18 09:05 AM Ion pumps are pretty common and cheap on ebay, easier to run and obtain for a hobbyist 22-Nov-18 09:06 AM Eh 22-Nov-18 09:06 AM I'm not going to say eBay ion pump is a good idea 22-Nov-18 09:07 AM It's like any other ebay pump 22-Nov-18 09:07 AM Can find great ones or lousy ones. Same as diff and turbo 22-Nov-18 09:07 AM Except ion pumps have a limited shelf life even when at vacuum 22-Nov-18 09:08 AM True, but they last a while. You can recondition them to an extent through baking, though they do have a finite capacity 22-Nov-18 09:09 AM My experience bring up systems that have even just been at residual vacuum for some time is the ion pump is a massive limiting factor 22-Nov-18 09:09 AM Even after heavy bakes and argon surface cleaning 22-Nov-18 09:09 AM We use ion pumps almost exclusively, they have strength and weaknesses 22-Nov-18 09:09 AM Have always had to replace them 22-Nov-18 09:09 AM The ion pump needs to be rated for the gas used though 22-Nov-18 09:09 AM Some are strictly for nobels, others for non Nobel gases 22-Nov-18 09:09 AM Ours last for years 22-Nov-18 09:10 AM Yeah, I haven't had to use a tantalum pump before 22-Nov-18 09:10 AM My problem with eBay pumps is all the ones just sitting at atmosphere with foil on them 22-Nov-18 09:10 AM Very different than say getting one that's past shelf life but still under vacuum 22-Nov-18 09:13 AM Yeah, not saying they would be great, but could be useable. Ones at atmosphere would need a lot of baking and conditioning to get them useable, assuming they are in good condition to begin with 22-Nov-18 09:13 AM If you want to get deeper UHV on a budget, ion is a potebtial option, especially if you can't access cryo stuff. However, if you are using ion pumps, you can't be working with a high gas load system. Whatever process you are using with it, it has to be low load 22-Nov-18 09:16 AM That's for sure 22-Nov-18 09:16 AM Even load lock systems are brutal on IGPs 22-Nov-18 09:16 AM Outgassing from ceramic insulators has also caused a lot of headaches in the past on igp 22-Nov-18 09:16 AM Especially on Thermionic systems 22-Nov-18 09:41 AM hi 22-Nov-18 10:43 AM hmm, but most solder is UHV compatible, right? 22-Nov-18 10:43 AM i mean, they are mostly SnAgCu alloys 22-Nov-18 11:12 AM You have to look at the vapor pressure of the components though. Silver and copper are fine, but the tin is a limiting factor. While it can work at high vacuum, getting to deeper UHV requires baking and pumping. Also the fluxes are a contamination issue as well. Remember, there is a big difference between high vacuum and ultra high vacuum. Things that were fine at 10^-6 or 10^-7 may not be fine at 10^-10 22-Nov-18 11:12 AM Generally all solders are avoided for any bonding in UHV, and if used, kept to an absolute minimum 22-Nov-18 11:12 AM You can bake at lower temperature if there are limiting materials, but pumping time increases significantly as a result. However to get the gas load down sufficient for the highest vacuums, baking is a must to remove adsorbed gas 22-Nov-18 11:12 AM here is a great presentation from USPAS overviewing UHV materials: http://uspas.fnal.gov/materials/13Duke/USPASVacuumSession4_1VacMaterials.pdf 22-Nov-18 11:12 AM I believe I have included this download in the Vacuum Folder that I passed on the @AdamMcCombs to share 22-Nov-18 11:12 AM Of course if you are using high load handling pumps like cryopumps you can handle higher outgassing loads. There are a lot if factors to consider. The major equation to remember is S=Q/P. Speed = gas load/ultimate pressure 22-Nov-18 11:12 AM However even this equation gets complex when calculating everything, accounting for effective speeds, conductances, outgassing based on material and conditioning levels, etc 22-Nov-18 11:53 AM Yep 22-Nov-18 02:22 PM @robamacl seen "selfmade" flex feedtroughs 22-Nov-18 02:29 PM So those most definitely work 22-Nov-18 02:29 PM But also seen FR4 boards with flex connectors and then cast in place with epoxy 22-Nov-18 02:29 PM But that's most definitely not UHV 22-Nov-18 02:29 PM FR4 outgassing is easily noticable at -5 22-Nov-18 02:31 PM You can definitely make high vacuum feedthroughs on the cheap rated to at least 10^-6 without much issue 22-Nov-18 02:31 PM Yep 22-Nov-18 02:31 PM We do our own at work 22-Nov-18 02:31 PM due to the amount of signals 22-Nov-18 02:32 PM We have done this as well. Getting a custom feedthrough for tons of signals costs an arm and a leg. If your vacuum isn't too high, it's a great option 22-Nov-18 02:33 PM Yeah we have +500 :X 22-Nov-18 02:33 PM Holy crap that's a lot 22-Nov-18 02:33 PM What type of system is it for? 22-Nov-18 02:33 PM Thz imaging 22-Nov-18 02:33 PM vacuum is mainly used for thermal insulation 22-Nov-18 02:33 PM Sounds pretty cool! 22-Nov-18 02:34 PM Yeah. Awesome job where I get to work with cool tech 22-Nov-18 02:34 PM vacuum, sensitive preamps, custom silicon, superconductors, THz, THz optics, cryogenics and other fun stuff. 22-Nov-18 02:39 PM Haven't done anything with Thz, but it's really awesome stuff. Sounds like a fun job! 22-Nov-18 05:10 PM @qualia This is what I was talking about with focus instability 22-Nov-18 05:10 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Scan_10-E8E07.jpg 22-Nov-18 05:10 PM That's a 30 second scan. It was making any kind of image acquisition pretty hard. 22-Nov-18 05:12 PM Weird 22-Nov-18 05:12 PM It's either accelerating voltage instability or objective lens instability 22-Nov-18 05:12 PM Is this with your digital acquisition unit @AdamMcCombs 22-Nov-18 05:12 PM Yeah 22-Nov-18 05:12 PM Because you can work around it with some correlation 22-Nov-18 05:13 PM not really 22-Nov-18 05:13 PM If you've got an fpga you should be able to cross correlate frames shouldn't you? 22-Nov-18 05:13 PM No there is to much drift in the rest of the system 22-Nov-18 05:13 PM Aw 22-Nov-18 05:13 PM Is the drift because of charge buildup? 22-Nov-18 05:14 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-FD316.png 22-Nov-18 05:14 PM No everthing from sample instability to beam drift from hysteresis in def coils. 22-Nov-18 05:14 PM It better just to fix the lens 22-Nov-18 05:14 PM Its also really hard to run the scope at high mag with this kind of instability. I dont have time to correct other things like stigmation when the image doesnt come close to staying in focus 22-Nov-18 05:16 PM Yeah 22-Nov-18 05:16 PM Any plans on how to troubleshoot? 22-Nov-18 05:17 PM Yeah start looking at waveforms 22-Nov-18 05:17 PM trace it through the feedback circuit and find where the input does not match the output 22-Nov-18 05:17 PM Im pretty sure it's in the lens and not voltage, voltage would likely cause other symptoms beyond just focus 22-Nov-18 05:17 PM Stigmation was pretty stable during this, which would be thrown off by voltage 22-Nov-18 07:52 PM whats the feedback circuit look like? 22-Nov-18 07:52 PM just reflecting the beam straight back? 22-Nov-18 07:52 PM well obviously not directing the beam straight at the sensor that would be stupid 22-Nov-18 07:53 PM zero cross going to a current limited capacitor charge discarge circuit to a lens driver circuit 22-Nov-18 07:53 PM it's just feedback on lens current 22-Nov-18 07:53 PM yeah, thatmakes sense 22-Nov-18 07:53 PM my scope is not that smart 22-Nov-18 07:53 PM well hey if you want a smarter scope theres a bunch on craigslist here >.< 22-Nov-18 07:53 PM ... 22-Nov-18 07:53 PM pfffty 22-Nov-18 07:53 PM https://boston.craigslist.org/nwb/ele/d/audiophile-6-ft12-gauge-power/6736308853.html 22-Nov-18 07:53 PM "audiophile power cable" 22-Nov-18 07:53 PM ooof, all the computer parts are super on sale 22-Nov-18 07:53 PM I shouldnt 22-Nov-18 07:53 PM but I kinda want to 22-Nov-18 08:41 PM ooof 22-Nov-18 08:41 PM total cost of pc parts that i just specced: $1600 22-Nov-18 08:41 PM I guess now I wait, see if price dips significantly for black friday/cyber monday, and if it does I hit buy? 22-Nov-18 08:41 PM worst case I'll just buy the power supply and the liquid cooling elements and I'll buy the workhorse components another time? 22-Nov-18 08:41 PM shrugs 22-Nov-18 09:58 PM man I really like openscad... 22-Nov-18 09:59 PM But? 22-Nov-18 09:59 PM no, no but 22-Nov-18 09:59 PM Ijust really like it 22-Nov-18 09:59 PM i think its a clever design 22-Nov-18 09:59 PM Oh cool 22-Nov-18 09:59 PM its slow 22-Nov-18 09:59 PM yeah... 22-Nov-18 09:59 PM But still its pretty clever 22-Nov-18 10:00 PM but im ok with that, I like the way its basically just pushing polygons into the shapes you want 22-Nov-18 10:00 PM and the children() mechanic is great 22-Nov-18 10:00 PM Yeah i was going to say some of those functions are pretty powerful 22-Nov-18 10:01 PM and the fact that you can make it all variable based, and then just change the variables and get a whole new part is great 22-Nov-18 10:01 PM im designing this part without measurements rn 22-Nov-18 10:01 PM im speccing the basic structure, and then im going to go get actual lengths and plug those into the variables 22-Nov-18 10:01 PM Yeah when I do fusion work I try to do similar stuff. Makes design revs easy 22-Nov-18 10:02 PM mmmhm, plus its how i learned to do engineering in general as a circuit designer 22-Nov-18 10:02 PM you solve the circuit as a set of dependencies, choose what spec to use as your anchor, leave yourself some wiggle room, and then plug-and-play your way through the system 22-Nov-18 10:02 PM @AdamMcCombs funny thought: think there would be a way to make 3DP parts via, like, resin DLP, that would be vacuum tolerant? 22-Nov-18 10:02 PM I know the Form1/Form2 can do microfluidics things 22-Nov-18 10:05 PM No resin is going to be hard 22-Nov-18 10:05 PM yeah a lot of outgassing 22-Nov-18 10:05 PM I mean it depends on what vacuum you are going to 22-Nov-18 10:05 PM would outgassing be the main concern? 22-Nov-18 10:06 PM yes and possibly virtual leaks 22-Nov-18 10:06 PM but outgassing alone is going to be killer 22-Nov-18 10:06 PM virtual leaks? 22-Nov-18 10:07 PM Yeah, any pockets or inclusions will slowly leak trapped gas for very long periods of time 22-Nov-18 10:07 PM Not a true leak to atmosphere, but slow enough that it causes issues for a long time 22-Nov-18 10:07 PM yeah I figured as much, im mostly wondering what it would take to make somethnig that gets the job done 22-Nov-18 10:07 PM and I guess I have no idea 22-Nov-18 10:07 PM Even bolts inside vacuum are center drilled and slotted so trapped gases in the threads can escape 22-Nov-18 10:07 PM 3d printing for vacuum is hard 22-Nov-18 10:07 PM like you said, its basically just ceramics + metals in there that can be permitted, right? 22-Nov-18 10:08 PM At UHV levels 22-Nov-18 10:08 PM and some other stuff but yeah 22-Nov-18 10:08 PM hv is much more forgiving 22-Nov-18 10:08 PM There are some UHV plastics 22-Nov-18 10:08 PM you can get away with a lot 22-Nov-18 10:08 PM Teflon can be used, as well as PEEK 22-Nov-18 10:08 PM so, it would need to be laser-sintered or some other such thing, but in such a way that it wouldnt be porous /at all/ 22-Nov-18 10:09 PM any porosity would be a killer for UHV 22-Nov-18 10:09 PM Teflon is used in some differentially pumped rotating flanges for uhv stuff 22-Nov-18 10:09 PM you start to look at expansion ratios and things get insane 22-Nov-18 10:09 PM i figured that would be the answer, its mostly just that my brain kinda seized on the idea of like 22-Nov-18 10:09 PM additive manufacturing for vacuum applications 22-Nov-18 10:09 PM because i feel like, if it could be done, that would be really realy useful, right? 22-Nov-18 10:10 PM Not really beyond just structural stuff 22-Nov-18 10:10 PM ceramic stuff yes 22-Nov-18 10:10 PM but when you need crazy vacuum ceramic you need crazy vacuum ceramic, and printing that is hard... 22-Nov-18 10:11 PM yeah, i cant think of a way to do it 22-Nov-18 10:11 PM i just think its a neat problem 22-Nov-18 10:12 PM Definitely ceramic stuff for sure, even metal stuff if porosity was eliminated. But for probably down to 10^-7 levels it could be possible with what is available now 22-Nov-18 10:12 PM Viton can be used to 10^-9 properly prepped 22-Nov-18 10:13 PM ...oooooh idk if any of you guys are also into mobile security stuff but: https://medium.com/@topjohnwu/from-anime-game-to-android-system-security-vulnerability-9b955a182f20 22-Nov-18 10:13 PM Yeah just cleaning 3d printed parts is going to be hard 22-Nov-18 10:13 PM basically, topjohnwu makes a rooting tool, and it tries to hide its action, and a lot of anime games do things to work around it. in trying to block those workarounds, he wound up discovering a major android OS flaw 22-Nov-18 10:13 PM sorry, adhd is happening 22-Nov-18 10:13 PM anyway, yeah, I can't see any way to make that doable 22-Nov-18 10:13 PM feel like that would be a really interesting project for a matsci phd 22-Nov-18 10:16 PM Definitely could make a great thesis topic 22-Nov-18 10:16 PM Super late over here, I'm off to bed. Talk to you all tomorrow! 22-Nov-18 10:17 PM right? like, im sure there is /some/ solution, but idk what 22-Nov-18 10:17 PM yeah! sleep well! 22-Nov-18 10:17 PM o/ 22-Nov-18 10:24 PM Night 22-Nov-18 10:35 PM 3D printing could be used as plugs for metal casting, it eliminates the immediateness of just 3D printing, but can get you very complex parts. 22-Nov-18 10:35 PM Also, morning \o/ 23-Nov-18 12:44 AM @hedgeberg how about 3dprinting in a vacuum 23-Nov-18 12:45 AM There are already 3d printer systems that use e beam welding and run in vacuum, they still don't quite have the properties of a chunk of 316 stainless 23-Nov-18 12:45 AM Interesting 23-Nov-18 12:46 AM Look up Electron-beam additive manufacturing if you want to learn more 23-Nov-18 12:50 AM Oh, its basically laser sintering 23-Nov-18 12:50 AM Hi 23-Nov-18 12:52 AM Moin! 23-Nov-18 12:53 AM Sometimes there are cheap electron beam welders (with vacuum chamber) on eBay maybe we could mod one to be an e-beam slm system? 23-Nov-18 12:53 AM Ahm, SM no L involved 23-Nov-18 12:53 AM SpaceX uses this for engine parts, right? 23-Nov-18 12:53 AM EBM 23-Nov-18 12:59 AM Yeah. It's probably the closest you would get for serviceable in high vac 23-Nov-18 01:05 AM BTW ever tried e-beam induced deposition? 23-Nov-18 01:05 AM On purpose? 23-Nov-18 01:06 AM I mean deposition from precursor gases induced by the secondary electrons from the substrate surface 23-Nov-18 01:06 AM Yeah on purpose to build tiny objects 23-Nov-18 01:06 AM EBID is the correct acronym iirc 23-Nov-18 01:09 AM I mean I do it on accident all the time in instrument columns... I looked into for my scope but don't quite have the differential pumping to pull it off 23-Nov-18 01:09 AM Ah ok 23-Nov-18 01:10 AM If I could hack one more pumping stage into my column I could do it 23-Nov-18 01:10 AM The apurtures are there for it, and I can mount the igp to my gun, just have to get an igp in before my first condenser lens 23-Nov-18 01:10 AM That intermediate cylinder is where I was thinking about trying to hack in another IGP the get enough differential for ebid 23-Nov-18 01:10 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/XWDLb4uHfdoUGK9qEsjpoAi1y6nRjOIXSRHDDlBQuz-2F230.png 23-Nov-18 01:10 AM If i get another sem ahem jeol jsm6320f then i might do that with my 35c 23-Nov-18 01:28 AM In general there’s just so much hype in the world around 3d printing, like this belief that it is the solution for every problem 23-Nov-18 01:28 AM It’s usually not 23-Nov-18 01:31 AM I think it's a solution in a different way than just being able to make parts, but being able to change the way you trade engineering and manufacturing time 23-Nov-18 01:33 AM Morning @N00N 23-Nov-18 01:33 AM /slightly hacking the thread for a second/ 23-Nov-18 01:33 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20181123_103419-2E58F.jpg 23-Nov-18 01:33 AM Everyone needs a rotary table in their lifes. /Now, go on/ 23-Nov-18 01:42 AM nice 23-Nov-18 01:53 AM yeah, i need one too (rotary table) 23-Nov-18 01:58 AM Nice 23-Nov-18 01:59 AM Its just that it's harder to severely harm yourself when using a cheap 3dprinter untrained than a lathe. 23-Nov-18 01:59 AM (I absolutely do want access to a lathe) 23-Nov-18 02:16 AM What do you need, Leona? 23-Nov-18 02:16 AM Or is just to "play" (in the serious sense of learning) 23-Nov-18 02:16 AM You where talking about SEM's please, do continue. 23-Nov-18 02:20 AM Nothing specific (yet). but I want to learn and metal manufacturing is so fascinating 23-Nov-18 02:25 AM If you're anywhere near me you could come by and try the lathe 23-Nov-18 02:25 AM That's a nice offer. I think you're several hours of travel away though 23-Nov-18 02:26 AM if ^^ 23-Nov-18 02:37 AM oh are you both from germany? 23-Nov-18 02:41 AM Yeah 23-Nov-18 02:42 AM yep 23-Nov-18 02:47 AM \o/ 23-Nov-18 02:47 AM lower saxony? 23-Nov-18 02:49 AM munich ^^ 23-Nov-18 02:51 AM Hesse 23-Nov-18 02:56 AM ah ok ^^ 23-Nov-18 03:20 AM @N00N are you from germany, too? 23-Nov-18 03:34 AM @GigaSquirrel yes 23-Nov-18 03:34 AM Wolfenbuettel 23-Nov-18 03:38 AM why are all of you so far away :< 23-Nov-18 03:38 AM it's not thaat distant 23-Nov-18 03:39 AM it is, if you have to pay the train ticket 23-Nov-18 03:40 AM yeah okay, that's where a car comes handy 23-Nov-18 03:40 AM hmm, maybe we already know each other... 23-Nov-18 03:40 AM but first let's move this to #off-topic-thats-sometimes-on-topic ^^ 23-Nov-18 03:40 AM to OT? ok 23-Nov-18 03:43 AM final hijack of thread Look at how f awesome is: 23-Nov-18 03:43 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20181123_124358-A538D.jpg 23-Nov-18 03:45 AM Very nice! 23-Nov-18 03:45 AM have you done a leak test? 23-Nov-18 03:47 AM Is there an o-ring? How is it sealed? 23-Nov-18 03:50 AM looks like there's an o-ring inbetween the two parts, getting pressed against the glass when the screws are tightened 23-Nov-18 03:52 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181123_124838-88830.jpg 23-Nov-18 05:06 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181123_140217-DB185.jpg 23-Nov-18 05:06 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181123_135837-2EAB4.jpg 23-Nov-18 05:06 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181123_135853-39C0A.jpg 23-Nov-18 05:06 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181123_135935-8E22A.jpg 23-Nov-18 05:06 AM it's starting to take shape 23-Nov-18 05:06 AM not as nice as it'd like it to be, but that's just optics and wont make it worse 23-Nov-18 05:20 AM I haven't done a leak test yet, I wanted to see first if the o-ring itself did hold with temperature. (by the time I'm answering, yes, it does hold). The two pieces have ramps to compress the o-ring against the glass and between themselves, creating a seal. 23-Nov-18 05:20 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DpzPScKXUAAFlCU-F0455.png 23-Nov-18 05:20 AM (that is an old model, newest has the threads inverted, so you can turn the screws from the KF-40 flange side), but you get what I mean) 23-Nov-18 05:30 AM what o-ring material? Some high temperature stuff or regular NBR? 23-Nov-18 07:20 AM Ooh that’s beautiful Nixie 23-Nov-18 07:20 AM First world problems: I’m in cleanroom but I really need to pee but I would have to go and de suit and I’m in the middle of something 23-Nov-18 07:30 AM @a_quiet_scientist Pee everywhere, go out like a legend. @GigaSquirrel they are Viton, It's supposed to withstand 230ºC constant. 23-Nov-18 07:38 AM And now, since noone seems to be saying much, here, the ultimate beauty shot: 23-Nov-18 07:38 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DssqvHOWkAIOg4j-7F0C9.png 23-Nov-18 07:39 AM sexy 23-Nov-18 07:39 AM do you've ever build CF stuff from aluminium? (mean all of you) 23-Nov-18 07:40 AM CF? 23-Nov-18 07:40 AM is there a special sauce to make the edges working? 23-Nov-18 07:40 AM @Nixie really nice, looks awesome! 23-Nov-18 07:40 AM CF in aluminum is a major challenge 23-Nov-18 07:41 AM @Nixie ConFlat 23-Nov-18 07:41 AM Yeah, very nice! 23-Nov-18 07:41 AM I've got papers from CERN that deal with some technical challenges of it 23-Nov-18 07:41 AM Hmmm...no, I'm not in the business of UHV, so I don't need conflats, but to be made out of aluminium, the sealing rings would have to be quite soft. 23-Nov-18 07:41 AM the thing with the "knife" edges and copper gaskets 23-Nov-18 07:42 AM Thanks all ^^ I am super pleased with them. 23-Nov-18 07:42 AM @Applied_Ion yeah, found those too and from DESY 23-Nov-18 07:42 AM If they struggle with it, then you know it's tough. There are aluminum CF, but the edge must be hardened, and you have to use softer metal seals 23-Nov-18 07:42 AM discussions about different edge geometries and stuff like that 23-Nov-18 07:42 AM Yeah 23-Nov-18 07:43 AM ok, softer than copper? 23-Nov-18 07:43 AM But there are standard vacuum manufacturers that do make them 23-Nov-18 07:43 AM yeah 23-Nov-18 07:43 AM Yeah, usually aluminum conflat seal rings 23-Nov-18 07:43 AM my question is about "how to harden the edges properly" 23-Nov-18 07:43 AM Why would they need aluminium vacuum equipment? 23-Nov-18 07:44 AM I think a process like nitriding or titanium deposition 23-Nov-18 07:44 AM it's not so easy to activate 23-Nov-18 07:44 AM Other option is the explosively welded stuff 23-Nov-18 07:44 AM That too lol 23-Nov-18 07:44 AM and it's lighter and it has better thermal properties 23-Nov-18 07:44 AM and it is not magnetic 23-Nov-18 07:44 AM all the probs you have with iron based stuff, it has them not 23-Nov-18 07:44 AM Yeah, magnetic and activation are usually the areas where you would use it 23-Nov-18 07:44 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181116_123416-B4D6C.jpg 23-Nov-18 07:45 AM True...what a horrible can of worms. 23-Nov-18 07:45 AM X-plosion! 23-Nov-18 07:45 AM what is it for, @AdamMcCombs ? 23-Nov-18 07:45 AM xplosion welding is awesome 23-Nov-18 07:45 AM not that i've ever did stuff like that 23-Nov-18 07:45 AM That's copper titanium stainless 23-Nov-18 07:46 AM Also @Nixie , careful with viton at above 200C continuous, the typical rating of viton for bake out is 150C continous safely, and 200C max for short periods 23-Nov-18 07:46 AM That one is for some cryo hardware, but aluminum+stainless is also comon 23-Nov-18 07:46 AM @AdamMcCombs nice! Explosion bonded stuff is really cool 23-Nov-18 07:47 AM Oh, I had read it was 230 continuous and above for short periods. 23-Nov-18 07:47 AM Viton will in some applications hold to 4 or 500 23-Nov-18 07:47 AM any recomendations for new o-rings? 23-Nov-18 07:47 AM Yeah short periods is fibe 23-Nov-18 07:47 AM Is it for vacuum or general sealing? 23-Nov-18 07:47 AM No, here it's just sealing, or just low pressure. 23-Nov-18 07:47 AM You just have to scrape it off the flange when you are done 23-Nov-18 07:48 AM to mantain Argon inside, mostly. 23-Nov-18 07:48 AM Then you are fine 23-Nov-18 07:48 AM They do that on ion getter pumps during final bake out 23-Nov-18 07:49 AM Okay! 23-Nov-18 07:58 AM Really nice machining though, it must be great to have the capabilities to make what you need, sure can save a lot of money! Especially custom KF stuff 23-Nov-18 08:03 AM It has taken me years to get all the machinery. ^^U But I'm missing some tools (mainly mirror images of lathe tools, for example) But yes, this whole 2018 it's been the culmination of all that. XD BTW, I just removed the test endcap, the oring (wich was super compressed to ensure good holding power) has slightly formed into shape from the pressure, but other than that, doesn't seem fused at any point (hasn't adhered to the point of having to scrape to the stainless or the glass). So, once I get the KF-40 endplates (I'm lazy and they where cheap) I will be good to go. 23-Nov-18 08:03 AM Also, I haven't done much custom KF...now that you mention it. 23-Nov-18 02:30 PM Yo! Anyone know (uk) where I can get an FFL 1/4" to NPT adapter? Or even FFL to KF-16? I've got a Robinair 15501E and zero way to connect it to my EXT70 Turbo ;( 23-Nov-18 02:30 PM I've found some US solutions on eBay but international shipping is ££ 23-Nov-18 04:00 PM Actually I ended up needing to adapt from flared fitting to kf25 on my pump 23-Nov-18 04:00 PM Had to make several steps from flared to npt then to kf 23-Nov-18 04:00 PM Hold on I can find the parts liat, I may have recorded where I bought everything as well too 23-Nov-18 04:00 PM @meowter_space here is a photo of my adapter stack from flare to kf25: 23-Nov-18 04:00 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/SuperEvac_Backing_Pump_Close-up_-_Brass_Fi-15E07.jpg 23-Nov-18 04:00 PM The pump inlet is a 3/8" male flare fitting. I go from a 3/8″ female flare to 1/2″ male flare adapter, then 1/2" female flare to 1/2" male NPT. The final fitting is a 1/2" female NPT to kf25 23-Nov-18 04:00 PM I got all of the brass adapters from Amazon for quite cheap, and the NPT to Kf25 from LDS Vacuum Shopper 23-Nov-18 04:00 PM Unfortunately I don't know if there are cheap shipping options depending on your location. I am in the US, so its generally easier to get good deals on eBay or other online sellers. I know that there are definitely flare to npt. I don't think there are flare to KF, so if your setup is similar to mine, you will have to go from flare to NPT to KF. 23-Nov-18 04:00 PM I did vacuum check and verify this assembly down to 10^-3 torr, and got the blanked-off foreline pressure for this pump to about 1.25*10^-2 torr, which is probably the limit of this type of pump. Sounds like your setup is similar to mine, though I'm using a Yellow Jacket SuperEvac 93560 and adapting to a diffusion pump inlet. 23-Nov-18 04:00 PM Sorry its not much help directly for actual suppliers in the UK 23-Nov-18 04:27 PM ^ i also use a very similar setup, although i'm using 60" of 1/4" FFL hose from my vacuum to an FFL tee and then FFL-to-NPT and then NPT to KF25 23-Nov-18 04:27 PM it was profoundly frustrating trying to convert flare to something usable, so sympathies 23-Nov-18 04:27 PM (i'd like to do more like what @Applied_Ion is doing and go straight to KF25 and then have a short-ish corrugated metal hose to my foreline bits for conductance's sake, but .. eventually) 23-Nov-18 04:29 PM Yeah, it took some searching for me as well. I opted for the largest diameter adapters I could find to keep the conductance high 23-Nov-18 04:30 PM https://www.amazon.com/gp/product/B008E5CUFG/ref=oh_aui_search_detailpage?ie=UTF8&psc=1 i have a bunch of these now for doing that, @meowter_space 23-Nov-18 04:30 PM so maybe a UK equivalent can be found 23-Nov-18 04:30 PM For my final setup, my foreline is a bit longer, I have a 6" kf25 bellows on this, then a tee for the gauge, a 3" bellows, then a manual isolation valve 23-Nov-18 04:30 PM @Applied_Ion does your superevac have an anti-suckback arrestor? 23-Nov-18 04:30 PM like, if you turn the pump off, does that gauge ~instantly drift up to atmosphere 23-Nov-18 04:32 PM No, it slowly rises. I've only tested it with a blanked off foreline, not with my diff pump yet 23-Nov-18 04:32 PM But no issues with oil backing up or anything. Also have the foreline trap as well 23-Nov-18 04:32 PM I also tested the isolation valve built into the pump, also good to 10^-3 torr, so it seems well sealed to levels better than it can operate at at the pump side 23-Nov-18 04:32 PM I can pull up a quick CAD model of my full foreline setup for reference 23-Nov-18 04:32 PM here is the full foreline assembly connected to the diffusion pump, minus the 8020 table and cooling system: 23-Nov-18 04:32 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Foreline_Assembly-D70AD.jpg 23-Nov-18 04:32 PM I haven't yet rebuilt the foreline to the above final version yet, just planned it out. I need to dissasemble it from its old configuration to the new topology for the final system 23-Nov-18 04:32 PM took a it of planning to get everything to fit into the space I had to work with. This is the final assembly for the pumping station: 23-Nov-18 04:32 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Integrated_High_Vacuum_Test_Stand_Assembly-1DFE2.jpg 23-Nov-18 05:50 PM Such pretty CAD 23-Nov-18 07:43 PM @Applied_Ion what software do you use? 23-Nov-18 07:43 PM Fusion 360 23-Nov-18 07:53 PM Yeah fusion 23-Nov-18 08:27 PM I need to order some stuff on mcmaster-carr! yay! 23-Nov-18 08:27 PM I love using mcmaster 23-Nov-18 08:31 PM Yeah same here 23-Nov-18 08:31 PM It's kinda magic 23-Nov-18 08:31 PM ordering form mcmaster is always a treat 23-Nov-18 08:31 PM whats the diameter of an M5 screw? 23-Nov-18 08:31 PM oh, 5mm 23-Nov-18 08:31 PM duh 23-Nov-18 08:31 PM wait why did i want rubber washers? 23-Nov-18 08:31 PM I wanted them for something but I dont remember why... 23-Nov-18 08:31 PM mmm... 23-Nov-18 08:31 PM im going to order 2 sets to be safe since I figure I'll remember soon enough 23-Nov-18 08:31 PM how is their shipping so god damn fast if everything is by ground? 23-Nov-18 08:31 PM I should really make a kelvin probe system one of these days 23-Nov-18 08:31 PM wonder if I'd be able to even potentially use it for really really light AFM? 23-Nov-18 08:54 PM TIL kelvin probes 23-Nov-18 08:54 PM pretty neat, right??? 23-Nov-18 08:54 PM We used them why I was at ARL to gauge the effectiveness of our diamond substrates 23-Nov-18 08:54 PM we were trying to figure out the source of some kind of carrier decay 23-Nov-18 08:54 PM that was the same summer I tried to use a low-frequency spectrum analyzer to try and extract carrier behaviors from flicker noise 23-Nov-18 08:54 PM that was a mess 24-Nov-18 02:23 AM I don’t think we can even get McMaster to ship here. I wish they did. But DigiKey is divine 24-Nov-18 02:42 AM Joined the server. 24-Nov-18 02:42 AM Moin! 24-Nov-18 02:42 AM Hamlo 24-Nov-18 03:06 AM anyone ever used one of those little i2c displays? the 64x48 raw bitmap ones? 24-Nov-18 03:09 AM Have one, but never tried it (didn't get into serial programing with PIC...I'm bad at programming :/ ) 24-Nov-18 03:11 AM me too, generally speaking 24-Nov-18 03:21 AM Welcome Cap'n! 24-Nov-18 04:18 AM Simple but effective variac and isolation transformer and bridge and capacitor : 0-360VDC. Useful! (I’m not sure how high I really want to go without making the 400V big capacitor angry) 24-Nov-18 04:18 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-07539.jpg 24-Nov-18 05:45 AM @qualia $4.26 international shipping Score! Thanks 24-Nov-18 05:45 AM not bad :3 24-Nov-18 05:45 AM good luck! 24-Nov-18 07:49 AM Nice! 24-Nov-18 11:43 AM is "bio foobar specimen prep" for SEM Off-Topic? 24-Nov-18 11:43 AM i mean for the channel #off-topic-thats-sometimes-on-topic 24-Nov-18 12:02 PM Depends, is it a question or a how to? 24-Nov-18 12:28 PM Question 24-Nov-18 12:28 PM Or the book is kinda howto 24-Nov-18 12:59 PM oh cute I have one of those tiny variacs NIB somewhere 24-Nov-18 12:59 PM low current but neat little thing 24-Nov-18 12:59 PM I also have a massive 240V like 20/30A? Variac in the basement >:) 24-Nov-18 01:07 PM My sputtering variac is a wimpy 3000W one. 24-Nov-18 05:48 PM Yeah I wanted something compact and low power, without using the massive heavy variac and transformer 24-Nov-18 06:47 PM @hedgeberg I have used some of those 128x32 and 128x64 I2C OLED's. But mostly just via existing arduino libraries. The datasheet for the controller looks quite sane tho, so I guess it would not be impossible to write one's own routines for it. But for my usecases existing stuff has worked fine. 24-Nov-18 10:42 PM meow meow 24-Nov-18 10:42 PM i think my latest spat of vacuum problems are all in however i reassembled my foreline 24-Nov-18 10:42 PM 'cos .. normally, closed up, it'd hold 1e-3 torr pressures for, like, several hours 24-Nov-18 10:42 PM and in watching leakup rates on my scope, it was up to like a torr in an hour 24-Nov-18 10:42 PM so yay 24-Nov-18 10:42 PM either something's really goofy in how i reassembled it, or i overestimated how forgiving KF seals are 24-Nov-18 10:45 PM You should be able to find that leak with alcohol if you have enough pumping capacity. 24-Nov-18 10:46 PM maaaaaybe 24-Nov-18 10:46 PM so like 24-Nov-18 10:46 PM oh wait 24-Nov-18 10:46 PM i was gonna ask how you dispense alcohol for leak-checking, but i just remembered i bought some plastic syringes for precisely this 24-Nov-18 10:48 PM What gauge are you using for this? 24-Nov-18 10:48 PM mks 901p 24-Nov-18 10:48 PM reads through 1k torr to 10^-5 torr pretty smoothly, updates at 16 Hz 24-Nov-18 10:48 PM hm 24-Nov-18 10:48 PM I dont know how alcohol will work with a transducer gauge 24-Nov-18 10:48 PM Possibly? 24-Nov-18 10:49 PM dunno either 24-Nov-18 10:49 PM If there are gas calibration tables for you it you can figure it out 24-Nov-18 10:50 PM i might be able to jury rig a hasting thermocouple gauge on the FFL tee just before my KF converter 24-Nov-18 10:50 PM i am mostly looking for 'did it move' 24-Nov-18 10:50 PM Yeah that would work 24-Nov-18 10:50 PM Pirani gauge is probably the best 24-Nov-18 10:51 PM 901p claims it's a micro-pirani but idk 24-Nov-18 10:51 PM how does a pirani gauge work? 24-Nov-18 10:52 PM Similar to thermocouple but just uses the resistance of the sense wire to measure temperature 24-Nov-18 10:52 PM I like them a lot 24-Nov-18 11:09 PM @hedgeberg I've used OLED I2C displays for Arduino and CircuitPython based projects. CircuitPython is my focus for most projects any more, at least for those that don't require high-speed processing or nifty signal processing libraries. 24-Nov-18 11:09 PM I didnt know anyone used arduino for sigproc stuff 24-Nov-18 11:09 PM anyway im in the middle of fighting with beaglebone to figure out why it wont load this kernel from an sd card 24-Nov-18 11:17 PM There are some decent signal processing libraries for the Teensy that are accessible through an adapted Arduino IDE. 24-Nov-18 11:25 PM oh right i always forget that arduino was the go-to way of dev for teensy 24-Nov-18 11:25 PM at this point I try to stay away from the arduino IDE, especially when good GCC is available, like it is for all the freescale teensies 24-Nov-18 11:25 PM learned build scripts/linker scripts almost entirely for that purpose! 24-Nov-18 11:25 PM @qualia wanna make a kelvin probe with me at some point? 24-Nov-18 11:25 PM I want to try to rig one up in such a way that i can do surface profiling 24-Nov-18 11:25 PM figure if i bonded a sample using conductive epoxy and set the surface voltage to some specific value, I should at least be able to find material boundaries by just profiling over x/y 24-Nov-18 11:39 PM i'm honestly probably gonna do most of my vacuum control stuff on a raspi at this point 'cos like i'm seemingly deathly allergic to anything that isn't python 24-Nov-18 11:39 PM it will maybe probably be sufficient 24-Nov-18 11:39 PM @hedgeberg i am intrigued but woefully uninformed 24-Nov-18 11:40 PM honestly at this point I wouldnt touch an RPi with a 10 foot pole 24-Nov-18 11:40 PM shoot 24-Nov-18 11:40 PM right 24-Nov-18 11:40 PM no swears 24-Nov-18 11:40 PM sorry 24-Nov-18 11:40 PM either way it seems this wonderful beaglebone black is really not here to be my firned 24-Nov-18 11:40 PM *friend 24-Nov-18 11:49 PM So you know those oscillators in iphones that are helium sensitive? I have a pile of them, a couple of microtomes with wired blade setups and a SEM... 24-Nov-18 11:49 PM This is going to be a fun night 24-Nov-18 11:49 PM I know that ben did some decaping work on them with sand paper, but I think I can get some better results by using some precision blade work with my microtome/ultramicrotome 24-Nov-18 11:51 PM i only mostly hate the RPi 24-Nov-18 11:51 PM idk where my BBB is 24-Nov-18 11:51 PM but i liked it 24-Nov-18 11:56 PM I'd like it a lot more if it worked rn 24-Nov-18 11:56 PM I'm leaning more and more towards just using my snickerdoodle 24-Nov-18 11:56 PM since it loads all things off of SD/MMC with 4 lanes instead of 1, doesnt mess with dual storage, has significant ram, and I actually have baremetal execution working on it 25-Nov-18 12:19 AM when in doubt, Use What Works(tm) 25-Nov-18 12:19 AM annoyed at how easy it is to buy things on ebay and how difficult it is to bring a project to completion 25-Nov-18 12:19 AM there's a meter of 4.5" conflat that i want to try and build a neutron spectrometer around but i'm like. i don't actually know how to do that so perhaps i should not actually buy the thing yet, even if it does seem like a good deal 25-Nov-18 12:19 AM self control is the worst 25-Nov-18 01:15 AM Damn this thing is small 25-Nov-18 01:15 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181125_011443-50BAC.jpg 25-Nov-18 01:15 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181125_011454-A6E67.jpg 25-Nov-18 01:15 AM Supper glue clamp looks like it might work nicely 25-Nov-18 01:15 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181125_011843-6DAB1.jpg 25-Nov-18 01:23 AM the iphone mems? 25-Nov-18 01:30 AM Yup 25-Nov-18 01:30 AM looking forward for the pictures! 25-Nov-18 01:31 AM Admitidy this is not normally how an ultra microtome is used 25-Nov-18 01:31 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181125_013056-64647.jpg 25-Nov-18 01:31 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181125_012954-99E4C.jpg 25-Nov-18 01:32 AM what's the blade made of? 25-Nov-18 01:33 AM Glass 25-Nov-18 01:33 AM As I said this is not this things intended use 25-Nov-18 01:33 AM sorry if that's a stupid question, but are you trying to cut silicon dioxide with silicon dioxide? 25-Nov-18 01:34 AM It likes the abuse 25-Nov-18 01:34 AM I mean that's pretty close 25-Nov-18 01:35 AM well, good luck I guess? 25-Nov-18 01:35 AM @qualia that nTOF project sounds so cool 25-Nov-18 01:35 AM Now you just need/want a fantastic 4 Pi full sphere scintillation detector array 25-Nov-18 01:35 AM https://ntof-exp.web.cern.ch/ntof-exp/ 25-Nov-18 01:35 AM I love that giant conflat pipe 25-Nov-18 01:35 AM I wish it wasn’t on the other side of the room and I had a bigger house for experiments 25-Nov-18 01:35 AM Other side of the world I mean 25-Nov-18 01:39 AM Well that was cool 25-Nov-18 01:39 AM https://photos.app.goo.gl/BA36CAbtNr5topV16 25-Nov-18 01:41 AM did you win 25-Nov-18 01:41 AM The link is video 25-Nov-18 01:44 AM What’s the best way to get 25kV supply small and cheap for electro spinning? I’m thinking TV flyback with ZVS drive probably 25-Nov-18 01:44 AM But I need to hunt peoples trash for a proper Farnsworth TV and none of this newfangled stuff the kids use that doesn’t even have a vacuum 25-Nov-18 01:45 AM Well I did something 25-Nov-18 01:45 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181125_014531-2364E.jpg 25-Nov-18 01:50 AM So it’s just another layer of packaging? 25-Nov-18 01:50 AM Using the 4 balls for a sense of scale it’s obviously very small 25-Nov-18 01:52 AM Yeah it's miniscule 25-Nov-18 01:52 AM It also just flew across the room 25-Nov-18 02:39 AM Oops 25-Nov-18 03:39 AM Are you trying to open a MEMS with a microtome? 25-Nov-18 04:19 AM 25-Nov-18 04:19 AM Xploding silicon kittens! 25-Nov-18 04:19 AM @a_quiet_scientist ask @Applied_Ion Hmm...would a flyback from a vacuum tube TV work? (It's been outdoors quite a bit now, I doubt it's in good condition) 25-Nov-18 04:19 AM Btw, the other day I was at a local fair and there was a mineral seller. He had "silicon rocks". They where broken pieces from a leftover boule. At 6€ I didn't pick one. But lol'd a lot. 25-Nov-18 04:55 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181125_135424-E81D2.jpg 25-Nov-18 05:08 AM oh wow tubes 25-Nov-18 05:08 AM if the HV section is enclosed off in a little enclosure of its own, there might be some salvageable goodies in there.. 25-Nov-18 05:08 AM actually i have no idea how well a bunch 'o valves would stand up to the elements but there's a nonzero chance some of those might still be good too if they're not corroded to heck 25-Nov-18 05:08 AM peers at the clock, debates whether now is the right time to take a hacksaw to their leaky NaI(Tl) scintillator 25-Nov-18 05:17 AM That photo os four months old, I am not sure if thst is still going to be in that same spot, it was the dry bed from a river, as it's been rainikg for a straight week. Maybe I'll go check for the lulz. 25-Nov-18 05:17 AM That semi repeat-double post is messing with my eyes 25-Nov-18 05:30 AM If anyone needs TV flyback transformers, I've got tons of them, just PM me your address and for the price of shipping they'll be yours 25-Nov-18 05:49 AM Fixing moisture damage in a NaI scintillator is basically impossible. There are supposedly some who claim they have an arcane secret way of doing it - which I suspect is grinding and repacking the crystal inside a dry nitrogen glovebox 25-Nov-18 05:49 AM Lol 25-Nov-18 05:49 AM That would do it 25-Nov-18 05:50 AM It's not totally impossible, just getting them back to <10% is 25-Nov-18 05:50 AM Boring... waiting for the cryopump ... entertain me? 25-Nov-18 05:50 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-1C487.jpg 25-Nov-18 05:50 AM I've had some success heating them, we got to ~20% FWHM 25-Nov-18 05:51 AM Nice 25-Nov-18 05:51 AM So is there enough thallium to kill you or not? There always seems to be this great debate between “harmless” and “will kill you” camps 25-Nov-18 05:52 AM I'm not dead, yet. 25-Nov-18 05:52 AM Nice 25-Nov-18 05:52 AM Thanks 25-Nov-18 05:52 AM Doping is 0.5-3% by weight, but I don't have the LD50 of Tl in mind right now 25-Nov-18 05:54 AM I got a couple of those common 1’’ square ones from AlphaSpectra and Bicron that often come up surplus they are nice little units 25-Nov-18 05:56 AM I've got those round russian ones in an Al can in various sizes 25-Nov-18 05:57 AM Working on attempt 2 on the decap... 25-Nov-18 05:57 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181125_055423-C7CE4.jpg 25-Nov-18 06:09 AM i actually have an outstanding bloodwork & heavy metal panel test i'm probably going to put off until after i disassemble my scintillator 25-Nov-18 06:09 AM just to see if it makes a blip 25-Nov-18 06:09 AM i highly doubt that it's normally at all very dangerous, though. saint-gobain has a blurb in their docs on their NaI(Tl) crystals basically saying 'well we did the math and handed it to our lawyers and they don't give a dang, so it's probably safe if you don't eat an entire 3" crystal puck' 25-Nov-18 06:09 AM but, yeah; i am less interested in recovering the crystal and more trying to yank out the PMT 25-Nov-18 06:09 AM just wanna see if it still works, and i could probably get up to other mischief with it 25-Nov-18 06:17 AM This is interesting, I have decapped 2 different osilator packages and judging by the available pads they use the same osilator die, in both a silicon on board chip and a epoxy version 25-Nov-18 06:17 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181125_022943-2E160.jpg 25-Nov-18 06:17 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181125_060314-E09DF.jpg 25-Nov-18 06:25 AM Hm... 25-Nov-18 06:25 AM Wasn't the mems encapsulated in epitaxial silicon? Wouldn't it be very difficult to "decap" if it is a single crystal capsule? 25-Nov-18 06:27 AM Yup 25-Nov-18 06:27 AM Acid doesn't touch it 25-Nov-18 06:29 AM Wait 25-Nov-18 06:29 AM You could unfeasibly oxide the surface then etch it. 25-Nov-18 06:29 AM The ampunt of tinenwould be fantastic though 25-Nov-18 06:30 AM Oof 25-Nov-18 06:30 AM That would take a lot of time 25-Nov-18 06:39 AM Oh damn that worked 25-Nov-18 06:39 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181125_063909-EF0E1.jpg 25-Nov-18 06:39 AM You can see the osilator in the middle of the die right there 25-Nov-18 06:45 AM Ooh 25-Nov-18 06:45 AM It’s DRIElicious 25-Nov-18 06:46 AM I think I'm going to try thermal shock on the next die 25-Nov-18 06:47 AM I’ve been meaning to get blood Pb panel one day just out of curiousity because they will never take all my Pb solder 25-Nov-18 06:48 AM Damnit 25-Nov-18 06:48 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181125_064840-45205.jpg 25-Nov-18 06:48 AM It's gone 25-Nov-18 06:48 AM Final step has to be done on a sample stud 25-Nov-18 06:53 AM Doh 25-Nov-18 08:14 AM @a_quiet_scientist you looking to do electrospinning? Not sure if you saw my mini diy series on electrospinning with hot glue. I only used 10kv, from a 5kv ac transformer and a 2 stage CW multiplier. Fortunately current isn't needed so you can get away with a lot of low current supplies. What type if electrospinning are you looking to do? 25-Nov-18 08:16 AM Thermal decaping actually worked surprisingly well. I wonder how well doing this under an inert atmosphere would work. 25-Nov-18 08:16 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181125_081444-F7CD4.jpg 25-Nov-18 08:16 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181125_080704-703F5.jpg 25-Nov-18 08:16 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181125_080912-FC15B.jpg 25-Nov-18 08:16 AM What really amazed me was that the bond wires still stayed attached 25-Nov-18 12:55 PM Joined the server. 25-Nov-18 12:56 PM Welcome! 25-Nov-18 12:57 PM thanks, i guess 25-Nov-18 01:20 PM woohoo I'm yellow. 25-Nov-18 01:21 PM you're special! 25-Nov-18 01:21 PM * 25-Nov-18 01:23 PM Welcome, altough I have no idea who you are. 25-Nov-18 01:23 PM thanks Nixie, i'm a clone of GigaBecquerel 25-Nov-18 01:23 PM Well they are a member of TDGS 25-Nov-18 01:24 PM that much i knew 25-Nov-18 01:24 PM Hello, clone! 25-Nov-18 01:24 PM Then what more do you need to know? 25-Nov-18 01:24 PM Who in twitter is to follow? 25-Nov-18 01:26 PM He's the person I talk about 99.9% of the time I say "we" 25-Nov-18 01:27 PM Ah! 25-Nov-18 01:27 PM Hello, we! I'm dad. 25-Nov-18 01:27 PM 25-Nov-18 01:28 PM ...a "Hi Daddy" would be inappropriate, i think 25-Nov-18 01:28 PM :-D 25-Nov-18 01:28 PM so... hi ^^ 25-Nov-18 01:28 PM ROFL, technically under rules, not yet... 25-Nov-18 01:28 PM See @welcome... 25-Nov-18 01:30 PM Nixie wonders...is the 0,1% "we" is some kind of radiation induced allucination of @GigaSquirrel 25-Nov-18 01:30 PM can neither confirm nor deny 25-Nov-18 01:31 PM 25-Nov-18 01:32 PM I think the point at which you get radiation induced amnisa is well past the matalic taste... 25-Nov-18 01:33 PM My luck of dain bramage says it's not dangerous. 25-Nov-18 01:36 PM well, brain damage itself is not dangerous I'd say, but things that cause brain damage are... 25-Nov-18 01:37 PM like trains? and falling pianos? 25-Nov-18 01:39 PM exploded tmp shrapnell 25-Nov-18 01:39 PM It's only like a 1000ft lbs of torque... 25-Nov-18 01:40 PM ...which is how much in real units? 25-Nov-18 01:40 PM Mumble mumble 25-Nov-18 01:41 PM ^.^ 25-Nov-18 01:41 PM ~1356 science units 25-Nov-18 01:42 PM thanks 25-Nov-18 02:01 PM serious () Question: I'm doing the oven endplates next. They will provide vaccum connection, argon connection and pressure release connection. Should I make the vacuum and argon connectors in opposite endplates, or can I get away with one, having the vacuum on top and argon on bottom, so the latter pushes the former? 25-Nov-18 02:02 PM the placing should not matter, as long as you don't go into high vacuum range 25-Nov-18 02:02 PM Nope, just slight vacuum. 25-Nov-18 02:03 PM worst case you'd have to flush for a bit 25-Nov-18 02:03 PM 25-Nov-18 05:22 PM @Applied_Ion yeah! That got me interested! Maybe a general power supply for electrospinning in a vague general sense - something easy that other people could reproduce with standard parts? 25-Nov-18 05:22 PM Hot glue maybe or something like PET or PLA dissolved in dichloromethane. Something flammable like acetone seems risky - too much chance of a spark from something. 25-Nov-18 06:17 PM huh that's weird, just typed out a response, and it was censored by the bot, saying watch your language. Didn't have any swears or anything remotely like that, so not sure what's up - just going over some hv power supply options. 25-Nov-18 06:29 PM ok hold on let me test something, I think I know why the bot keeps censoring me 25-Nov-18 06:29 PM yup - for anyone discussing voltage multipliers, typing out the full name of a cw multiplier or coccroft-walton voltage multiplier (spelled wrong on purpose), the first name gets the whole post censored... 25-Nov-18 06:29 PM @a_quiet_scientist that's great to hear! for high voltage dc supplies, really anything will work. There is really no current loading experienced by the supply, so you have a wide range of options to explore. There are a bunch of hv supplies on ebay for cheap that you could explore, or even cheaper would be to build your own. Two major topologies here: rectified, and high frequency switching. For rectified, one simple method is the coccroft-walton voltage multiplier, like I used. My setup was a 2-stage multiplier, with just 2 diodes and capacitors off a hv ac transformer. Parts don't have to be anything special - the transformer was salvaged from the trash, the caps were generic hv mica caps, but any non-polarized ones would work (like the small cheap ceramic ones), and the diodes were spare 10kv mot diodes I had lying around. The other rectifier-based option would be a bridge-rectified setup, either full wave or half wave. For switching, you could use a simple 555 driven ignition coil or flyback transformer. All of these can be built for super cheap using common and standard parts, and there are more resources than can be counted on how to build all of these for cheap. 25-Nov-18 06:29 PM if you want to get playing with electrospinning fast and cheap, hot glue is the way to go. Dirt cheap glue gun for a few dollars, no special setup or chemicals needed. It is definitely limited, but you can explore the basic principles. If you want to get into nanofiber production, solution spinning is the way to go. Good idea to stay away from flammable soultions, until you really know what you are doing and have tested it out 25-Nov-18 06:29 PM another thing to try that I havent been able to yet but Ive wanted for a while is to try electrospinning fibers from a 3d printer extruder. Should be interesting with all of the filament options available now. 25-Nov-18 09:06 PM Hello! 25-Nov-18 09:55 PM @Applied_Ion ok that has been fixed, sry about that 25-Nov-18 09:56 PM I do like the idea of a coco walton multiplier though 25-Nov-18 10:39 PM Welcome Irena! 26-Nov-18 02:26 AM Welp looks like it's to bring down the ban hammer 26-Nov-18 02:26 AM ?ban @Deleted User 26-Nov-18 02:31 AM Irena Sorensen#5878 was banned 26-Nov-18 02:31 AM Cool that was easy 26-Nov-18 02:33 AM hooray, our first spam! 26-Nov-18 02:38 AM Yaaaay! we're famous! 26-Nov-18 02:44 AM now we're a real server! 26-Nov-18 03:19 AM Joined the server. 26-Nov-18 03:19 AM Welcome! 26-Nov-18 03:19 AM Hi, just looking around friend of GigaBecquerel 26-Nov-18 03:20 AM Is it just me or do softbros almost always fundamentally not understand what an FPGA is 26-Nov-18 03:20 AM What's a softbro? 26-Nov-18 03:20 AM Softwareguys? 26-Nov-18 03:22 AM Seems likely from context. Sounds like a romantic self ID though ^^ 26-Nov-18 03:22 AM Particularly douchey ones who think “code” solves everything 26-Nov-18 03:23 AM "code" solves alot, but not everything 26-Nov-18 03:39 AM Welcome Erdnusstabak 26-Nov-18 05:31 AM why are most high resolution scintillators hygroscopic? 26-Nov-18 05:31 AM like, is there a chemical reason for it or does physics just hate us? 26-Nov-18 05:34 AM Cleaning out all the old stuff in the lab... there are old cupboards that have hardly been used for like 10 years. I pull out a small box of yellowed, old dusty cardboard and blow the dust off it. 26-Nov-18 05:34 AM Scrawled messily on the old cardboard box in felt tip pen is an eleven-letter word. 26-Nov-18 05:41 AM ? 26-Nov-18 05:47 AM Well your name will give you a hint 26-Nov-18 05:47 AM Alpha or gama? 26-Nov-18 05:49 AM I'm talking about gamma scintillators 26-Nov-18 05:49 AM the only thing i could find with <10% FWHM is CsI(Tl), which is only slightly hygroscopic, but nothing with a better resolution is non-hygroscopic 26-Nov-18 05:49 AM @a_quiet_scientist sorry, no clue 26-Nov-18 05:57 AM This package stayed together fairly well during the decap process you can see the die to die bond wires 26-Nov-18 05:57 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181126_052957-BBDB6.jpg 26-Nov-18 07:44 AM hmm 26-Nov-18 07:44 AM you want to split the anodic bond between the Si parts? 26-Nov-18 07:46 AM Yup. Any Clever ideas? 26-Nov-18 08:21 AM Well these actually worked out really well. I don't think I am going to keep going with the sheer method, it looks like it cause some internal deformation that I want to avoid. Onto sanding. 26-Nov-18 08:21 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Scan_29.tifMon-26-Nov-2018_08-18-52-F2C47.jpg 26-Nov-18 08:21 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Scan_32.tifMon-26-Nov-2018_08-18-52-6C0B5.jpg 26-Nov-18 08:21 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Scan_37.tifMon-26-Nov-2018_08-18-52-51A14.jpg 26-Nov-18 08:21 AM God I love SEM sometimes 26-Nov-18 08:22 AM would be sick to find such stuff in a fossile ^^ 26-Nov-18 08:22 AM btw, what's the part number? does digikey have them? 26-Nov-18 08:22 AM is it a SiT1532? 26-Nov-18 08:22 AM https://www.sitime.com/products/32-khz-oscillators/sit1532 26-Nov-18 08:22 AM i guess, i would try to etch 26-Nov-18 08:22 AM but your approach using a blade/edge is not the worst idea, i guess 26-Nov-18 08:30 AM https://www.youtube.com/watch?v=vvzWaVvB908&t 26-Nov-18 08:30 AM Applied science did a video on these device. We were talking about them at supper con and figured they would be pretty cool under SEM 26-Nov-18 08:30 AM This is the oscillator from the iPhones that cause them to crash when exposed to helium. 26-Nov-18 08:35 AM More like, brick up for days 26-Nov-18 08:35 AM Yeah fair 26-Nov-18 08:54 AM yeah, SiT1532 hmm 26-Nov-18 08:54 AM he sanded it open 26-Nov-18 08:54 AM the Applied Science dude i mean 26-Nov-18 08:54 AM @AdamMcCombs did you embedded it in epoxy before microtomation? 26-Nov-18 08:54 AM your images are better, higher contrast etc 26-Nov-18 08:54 AM would be nice to have a more gentle way to open MEMS 26-Nov-18 08:54 AM like wet or dry etching i dunno 26-Nov-18 11:20 AM Aww yiss, back among the living! 26-Nov-18 11:21 AM Woohoo, welcome back! 26-Nov-18 11:21 AM did the tea infusion do its job? 26-Nov-18 11:22 AM As they say, Three liters a day, Keep the fever at bay 26-Nov-18 11:26 AM I don't think I actually had a fever, but it still got worse before it got better. 26-Nov-18 11:34 AM good thing you're better now, so you can enjoy the fresh snow 26-Nov-18 11:34 AM got ~10 cm snow in the last 3 hours 26-Nov-18 11:40 AM Great! now you can dissasemble the pump 26-Nov-18 11:40 AM XDDDD 26-Nov-18 11:40 AM wait what, thw snow isn't melting anymore @GigaSquirrel ? 26-Nov-18 11:41 AM most of the area I see from my window is grass, maybe not the best reference 26-Nov-18 11:41 AM but it started laying put on the sidewalks when I got home 26-Nov-18 11:41 AM snow never melted again, engulfing the whole world in white, making life impossible The End 26-Nov-18 11:41 AM let's move this to #off-topic-thats-sometimes-on-topic 26-Nov-18 11:42 AM ah, ok. i think i'll wait another hour or so and then drive / drift back home... :-D (and i'm done with this topic now, so no need to move) 26-Nov-18 01:25 PM Joined the server. 26-Nov-18 01:25 PM childish excited squealing 26-Nov-18 01:25 PM is sad its not irc though 26-Nov-18 01:25 PM tl;dr: you people do cool stuff and I will be lurking 26-Nov-18 01:38 PM Welcome! 26-Nov-18 05:21 PM anyone happen to know of an intro to electron gun design? i've been messing around with a simple design with a wehnelt but don't know where to look other than intuition and e-field sims 26-Nov-18 05:23 PM There is a very good book on the subject that I believe was posted in the resources section. Full pdf book that was made free by the author 26-Nov-18 05:23 PM What type if electron gun? There are countless styles 26-Nov-18 05:23 PM In this field, sims are pretty necessary, as well as intuition and experience. But there are tons of resources on electron guns and optics online, and a plethora of academic papers available on the subject 26-Nov-18 05:25 PM ah thanks, I'll take a look in resources! (that sounds like Humphries' principles of charged particle acceleration?) 26-Nov-18 05:26 PM yeah, thats the one 26-Nov-18 05:26 PM I downloaded it a while ago and have gone through some of it, but not all of it in depth 26-Nov-18 05:26 PM very good book, but very involved as well 26-Nov-18 05:26 PM yeah, it's a great book -- i'm happy to have snagged a copy from a college library-closing sale 26-Nov-18 05:26 PM doesn't really apply to the guns I'm working on, but nevertheless an invaluable resource for standard electron guns 26-Nov-18 05:26 PM nice! 26-Nov-18 05:26 PM I do want a text copy, but the pdf book is perfectly fine for now 26-Nov-18 05:26 PM what simulation software are you using? 26-Nov-18 05:28 PM i've been messing around with agros2d, but I think a copy of simion is in my future 26-Nov-18 05:29 PM I've used simion for work, but I don't have anything for personal use besides Poisson, which is only a field solver 26-Nov-18 05:29 PM luckily this is for a work project so I've got /some/ funds available 26-Nov-18 05:29 PM never heard of agros2d 26-Nov-18 05:29 PM simion is really great, I like it, but it costs money that I don't have 26-Nov-18 05:29 PM agros2d is actually surprisingly good for being free scientific software 26-Nov-18 05:30 PM the other standard out there in the physics community are codes like EGUN, but they are very difficult to use, and aren't free either 26-Nov-18 05:30 PM (though i wish it crashed less often) 26-Nov-18 05:30 PM do you do gun design professionally? 26-Nov-18 05:30 PM nope, we're dabbling in it as a solution for some of our problems 26-Nov-18 05:31 PM what type of gun are you looking at? guns and injectors are the area that fascinates me the most 26-Nov-18 05:32 PM superfish seems super arcane to me, it's a little scary when the docs say "don't try to make something from scratch, just try to adapt an example" 26-Nov-18 05:32 PM uh, i think what we need is something in the low hundreds of eV and maybe a couple of mA but even that we're not sure of 26-Nov-18 05:32 PM it's sort of a coupled problem, i wish i could share 26-Nov-18 05:33 PM oh its arcane all right. And that saying is correct, especially in the accelerator field 26-Nov-18 05:33 PM so more of a company sensitive system? low hundreds of eV at mA should be pretty easy to build yourself. Also depends on what you need for spot size, emittance, energy spread, vacuum level, etc 26-Nov-18 05:36 PM yeah, the bigger background is getting more performance out of electric propulsion systems, so there's also magnetic fields at play 26-Nov-18 05:36 PM which is why we're trying to go in-house vs find someone more knowledgable -- integrating this touches all of the sensitive bits 26-Nov-18 05:36 PM it's definitely fun but i'm the blind leading the blind at this point :) 26-Nov-18 05:37 PM makes sense, so like a neutralizer gun for hall effect thrusters 26-Nov-18 05:37 PM thats where the fun is though! experimenting and learning as you go! 26-Nov-18 05:38 PM yup yup 26-Nov-18 05:38 PM i'm really glad i ended up in a startup where i get to do vacuum stuff again 26-Nov-18 05:38 PM particularly all of the small tricks like, "hey, do you have a bottle of nail polish?" "???" "oh just plugging some leaks" 26-Nov-18 05:42 PM sounds like a fun place to work! 26-Nov-18 05:42 PM I hope to start getting into propulsion work soon after my chamber is running. I will be running the vacuum simulations for my propulsion chamber hopefully next week, working on my smallest chamber this week 26-Nov-18 05:43 PM ooh, exciting! as a hobby project or freelance? 26-Nov-18 05:44 PM its all hobby. The propulsion chamber is in parallel with my accelerator development at home. Both open source efforts to help lower the barrier of entry into these fields 26-Nov-18 05:44 PM though not sure where I want to go with it moving forward, both have the potential for commercial applications 26-Nov-18 05:54 PM freelance would be pretty cool though, it would definitely help fund the research faster. I don't have much left to go forward for now, and I've hit a bit of a snag with my current funding source. Been selling my spare vacuum parts to other hobbyists, but the last guy I sold to has been delaying/ignoring paying for half of the parts, which has killed my budget so far. That order would have paid for the custom adapter plates I need, but I'm kind of stuck until it gets resolved or I save up. Fortunately I still have tons of design work to keep me busy, but it would be nice to actually get the vacuum system qualified. 26-Nov-18 05:54 PM As advice to others from personal experience, never ship parts until you get the payment in full (unless you really know/are friends with the buyer). I try helping other hobbyists as much as I can, but I'm kind of paying for it now (literally) 26-Nov-18 05:57 PM oof :( best of luck 26-Nov-18 06:03 PM thanks, though I'd rather not be the one to perpetuate the stereotype that engineers are lousy business people lol. It's a learning experience nonetheless 26-Nov-18 06:03 PM good luck with your gun design! sounds like a fun project to be working on! 26-Nov-18 06:12 PM also if you need additional resources on electron guns let me know, I have a bunch of papers on them, though not necessarily specifically related to neutralizer design (more from accelerator design, but the principles are all the same) 27-Nov-18 01:22 AM @Applied_Ion damn! Sorry to hear that, and that I could not machine the pieces for you 27-Nov-18 03:00 AM Behold! My KF-40 oven multipurpose feedthough (remember, not for High vacuum, just KF40 for size convenience). Interchangeable plugs, gas inlets/outlets, all M8, o-ring sealed. 27-Nov-18 03:00 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-F5B30.png 27-Nov-18 03:02 AM now you just gotta machine that ^^ 27-Nov-18 03:03 AM It's easy enough. Shame I don't have a knurler, so I can't do the fancy diamond pattern in the plugs. In any case, they should not be so tight you can't unscrew them by hand. (with a smooth surface) 27-Nov-18 03:03 AM Also, having done the adapters, I think I can do this. if those where challenging words. XDDD 27-Nov-18 03:03 AM Workholding/centering is going to be more complicated than the machining itself. 27-Nov-18 04:38 AM Another mems decap in progress... 27-Nov-18 04:38 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181127_043742-FFB46.jpg 27-Nov-18 04:38 AM I'm developing a very precise and scientific method for this. 27-Nov-18 04:38 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181127_042720-0A396.jpg 27-Nov-18 08:44 AM More mems in the morning 27-Nov-18 08:44 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181127_081613-93DDE.jpg 27-Nov-18 08:44 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181127_083431-6E4E1.jpg 27-Nov-18 08:49 AM Cool, look at all those perforations. Are those the holes Ben Krasnow was guessing were for letting the HF in to etch away the support structure? 27-Nov-18 08:49 AM This is a different device entirely 27-Nov-18 08:49 AM Accelerometer this time 27-Nov-18 08:51 AM Ah. Maybe similar purpose tho? 27-Nov-18 08:53 AM Possibly 27-Nov-18 08:53 AM Actually yes 27-Nov-18 09:28 AM and you decap it with fire? 27-Nov-18 09:42 AM Just heat, not the flame 27-Nov-18 09:53 AM Nice 27-Nov-18 09:53 AM Need to test nxt WE 27-Nov-18 11:31 AM @N00N I realized I forget to respond to why my scopes images look different than Ben's. Both of our scopes were manufactured by JEOL in the 70s. In Today's dollars, mine was sold as the top of the line and with everything on it was well north of a half million, possibly even 750k. Ben's we ~100-125k new... 27-Nov-18 12:57 PM Y'all see that oshpark is doing 2 layer flex now??? 27-Nov-18 12:57 PM Yeah wait until you see what else they are releasing soon 27-Nov-18 12:58 PM How come you already know? 27-Nov-18 12:58 PM Drew and I are friends... 27-Nov-18 12:59 PM Oh 27-Nov-18 12:59 PM Good for you, then 27-Nov-18 12:59 PM Assembly service for some pretty good rates 27-Nov-18 01:06 PM hax 27-Nov-18 01:06 PM Wait they're releasing assembly services too? 27-Nov-18 01:06 PM Man 27-Nov-18 01:06 PM OSH community is doing work recently 27-Nov-18 01:06 PM <3 drew, he's a really good guy 27-Nov-18 01:06 PM Anyway the release of easy-access flex pcb's means I'm going to be able to repair so many more things now. 27-Nov-18 01:22 PM Not sure if the price for the flexy is that good. I have to test some chinese manufacturers. 27-Nov-18 01:22 PM (of course, beimg un EU makes more difficult for me to use them) 27-Nov-18 01:52 PM I mean, oshpark is a small batch manufacturer with good quality control and friendly staff. It's not about the price point necessarily. 27-Nov-18 01:52 PM If you want a small batch production with good quality for prototyping purposes, then imo oshpark is the go-to. It's not the best price point or the best quality or the best shipping times, but it's a good blend of all 3 with good service 27-Nov-18 01:52 PM Anyway @AdamMcCombs good time to ask, do you know what the chemical makeup of standard chip encapsulation epoxy is? 27-Nov-18 01:54 PM No i dont 27-Nov-18 01:54 PM Because zeptobars' question has me curious 27-Nov-18 01:54 PM Its a clever idea though 27-Nov-18 01:54 PM Yeah 27-Nov-18 01:54 PM I am would not use this method if I wanted to run the chip again. This is just being used for mems stuff 27-Nov-18 01:55 PM I only worry that oxygen would decay the wires, which makes me wonder if another active gas could be used 27-Nov-18 01:55 PM I would be woried about the aluminum in the chip 27-Nov-18 01:55 PM most bond wires are gold or copper 27-Nov-18 01:55 PM I mean, if the chip is well-passivated, the aluminum would be fine, wouldn't it? 27-Nov-18 01:55 PM I think that is what he was talking about. 27-Nov-18 01:56 PM Especially since the oxygen is going to be pretty sparse near the surface of the chip? 27-Nov-18 01:56 PM Do we know anyone here that can do material decomposition using uh 27-Nov-18 01:56 PM Side not just found out im helping lift a TEM of through a roof in about a week so that's fun 27-Nov-18 01:56 PM What's the tool 27-Nov-18 01:56 PM A spectrometer? 27-Nov-18 01:57 PM Also going to be in 20 weather 27-Nov-18 01:57 PM but anyways 27-Nov-18 01:57 PM Like laser ablative stuff? 27-Nov-18 01:57 PM Yeah 27-Nov-18 01:57 PM Although you can also do it with deflected non-ablative light sometimes? 27-Nov-18 01:57 PM Yeah i dont know how well that works on plastic 27-Nov-18 01:58 PM Maybe I'm confusing spectrometry with Raman spectrum stuff? 27-Nov-18 01:58 PM yeah i think so 27-Nov-18 01:58 PM In some materials uv/vis or ftir reflections works 27-Nov-18 01:58 PM How would we go about getting a good chemical breakdown for chip epoxy? Do they sell it? 27-Nov-18 01:58 PM If so the msds should have it? 27-Nov-18 01:58 PM It's not like, a trade secret, right? 27-Nov-18 01:58 PM /me goes to Google 27-Nov-18 02:02 PM All i know is that different devices can have different compositions 27-Nov-18 02:08 PM Yeah, which means you'd want a solution that works for all epoxies.... 27-Nov-18 02:08 PM All the msds'es I'm seeing are for the pre-set compounds, and all are remarkably vague because, you know, trade secrets 27-Nov-18 02:08 PM Ugh 27-Nov-18 02:08 PM I can see that high temperature oxygen would work for most epoxies, but I can't really see much else and I have to think there's no way to be sure other than testing... 27-Nov-18 02:13 PM Reactive ion etching is a pretty popular process 27-Nov-18 02:13 PM Oxygen is also the usual gas for that. If you are going to do that though you need special pump oil otherwise you are effectively making a bomb 27-Nov-18 02:24 PM Yeah 27-Nov-18 02:24 PM Pure oxygen is not exactly fun to work with. 27-Nov-18 02:24 PM Although if you're just doing atmospheric pressure cvd oven stuff you could get away with just a mass flow controller? Then no oil would be needed? 27-Nov-18 02:26 PM So just running atmosphere through mfc? 27-Nov-18 03:25 PM Yeah? 27-Nov-18 03:25 PM I mean youd want to limit pressure using a valve but yknow 27-Nov-18 03:25 PM That way you can get constant inflow without having to use a proper pump? 27-Nov-18 03:25 PM Should be safe, right? 27-Nov-18 03:29 PM You use the same pump, you just have to use a special pump oil for o2 27-Nov-18 03:29 PM you can honestly just use a needle valve 27-Nov-18 03:53 PM Joined the server. 27-Nov-18 04:16 PM Well, there is officially a place at my work place that gets down to 15 MILLIKELVIN now... 27-Nov-18 04:16 PM Maybe lower I can't remember exactly 27-Nov-18 04:28 PM I made a filter thing for shop air, oil and particulate filter, then zeolite column, then micron filter on the output. I don't really know what it accomplishes because I don't have a way to analyze the output. 27-Nov-18 04:28 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180825_211438917-1518B.jpg 27-Nov-18 04:28 PM You can use air to get the oxygen without special O2 safety precautions or pump oil. But of course you get nitrogen too and other stuff. That's what I've been doing. 27-Nov-18 04:37 PM It's the "pressure swing" idea. When delivering air zeolite is at 20 psi, then I regenerate at low vacuum. Thought I might get O2 , concentration, so I tried to be sort of O2 safe, but that doesn't seem to be happening according to the classic "does a glowing splint relight" test. 27-Nov-18 04:37 PM Green tank is argon. 27-Nov-18 06:07 PM oh, at one point i remarked about an MBE system i saw on ebay that had.. problems. i found my tweet abt it: https://twitter.com/profanegeometry/status/1005016101363707904 27-Nov-18 06:07 PM second picture there is .. enlightening 27-Nov-18 06:08 PM i can't imagine those colors are desired 27-Nov-18 06:11 PM that's amazing 27-Nov-18 06:28 PM @qualia meh that's polishible 27-Nov-18 06:28 PM How much? 27-Nov-18 06:28 PM For an MBE system I'd give my left butt 27-Nov-18 06:28 PM snrk 27-Nov-18 06:28 PM idr, it was quite a bit under 100k iirc 27-Nov-18 06:28 PM ... also i am not sure if e-beam evap and MBE are the same kind of thing 27-Nov-18 06:28 PM just anytime i see a vacuum chamber full of sputter guns with flappy metal lids i think 'MBE' 27-Nov-18 08:52 PM if you wanted to rubberize a single surface of a PLA print, how would you go about it? 27-Nov-18 08:52 PM are there, like, high-friction rubberized coatings I can get? 27-Nov-18 08:52 PM the obvious answer is "rubber band" but idk if they come in the right size or how long theyd last 27-Nov-18 08:52 PM and theyd need to be a pretty weird shape 27-Nov-18 08:52 PM actually you know what, this is a good time for mister mcmasterr carr 27-Nov-18 08:52 PM I guess I could use o-ring stock? 27-Nov-18 08:57 PM plastidip? 27-Nov-18 08:58 PM plastidip? 27-Nov-18 08:58 PM what is? 27-Nov-18 08:58 PM never heard of it 27-Nov-18 08:59 PM https://www.amazon.com/Performix-12213-Plasti-Dip-Black/dp/B00I9SK8XY 27-Nov-18 08:59 PM (i should clarify, im making a spool holder for my 3d printer and i want it to be one that uses bottom rollers, but to make that work as well as possible i need a good decently-high friction seating between the spool edge and the bearing) 27-Nov-18 08:59 PM hm 27-Nov-18 09:00 PM also comes in a spray can 27-Nov-18 09:00 PM that may be perfect 27-Nov-18 09:00 PM no, id want to brush it on 27-Nov-18 09:00 PM does it come in smaller cans? 27-Nov-18 09:01 PM 14.5oz https://www.walmart.com/ip/Plasti-Dip-Tool-Handle-Coating/21015332 27-Nov-18 09:01 PM yeah, just found that 27-Nov-18 09:01 PM i guess thats what ill do then? 27-Nov-18 09:02 PM yea, I can't find a smaller one 27-Nov-18 09:03 PM been working a lot on the getting the filament tension issue resolved on this printer 27-Nov-18 09:03 PM i set up a filament guide, which has helped /a lot/ but now the feed rate doesnt catch, it does little regularly-spaced movements, which is a lot closer to a permanent smooth roll, but what id really like is oil the filament and have it at the point where, as long as the extruder is pulling, the spool is turning 27-Nov-18 09:03 PM so im trying to remove as much friction and variance from the system as possible. It's working, slowly. 27-Nov-18 09:05 PM makes sense. 27-Nov-18 09:05 PM need to think about getting an auto-levelling probe too 27-Nov-18 09:05 PM this was a super cheap printer, like 200 dollars, and my pet project rn is to modify myself to the point that it prints like a 2000 dollar printer 27-Nov-18 09:05 PM dont think that will actually happen until i replace all the electronics and retrofit it as, like, a much nicer printer 27-Nov-18 09:05 PM looks like everyone passed out already 27-Nov-18 09:05 PM quiet chatroom 27-Nov-18 11:03 PM Damn, I seem to have missed all the fun. 27-Nov-18 11:03 PM Morning, everyone \o/ 28-Nov-18 12:00 AM Hello 28-Nov-18 12:00 AM I'm babysitting the printer while I wait for this print to start, gonna see if these new settings work well or not 28-Nov-18 12:38 AM hey so if anyone has ever been curious about antenna design, its basically this for EM fields instead of acoustic systems: https://twitter.com/SimoneSchnall/status/1067436722961575942 28-Nov-18 12:38 AM (not literally but you know) 28-Nov-18 12:40 AM @AdamMcCombs ah ok ^^ not that cheapo 28-Nov-18 01:43 AM MBE is not really the same thing as e-beam evaporation. MBE is typically -8 to -12 vacuum and we typically run our e beam at about -6-7. MBE is kind of like a CVD process from solid sources and epitaxial. With a chemical reaction. For example a source of elemental Ga and elemental As yields high purity GaAs 28-Nov-18 01:43 AM E-beam evap is a PVD process with no chemical reaction generally 28-Nov-18 01:43 AM E-beam evap is much more isotropic than sputter so you can do liftoff well on small structures without coating the sidewalls 28-Nov-18 01:43 AM And anything evaporates including materials you wouldn’t think of as evaporating or melting usually 28-Nov-18 01:43 AM SiO2, Al2O3, tungsten, hafnium oxide, incredible flexibility with materials 28-Nov-18 02:07 AM @hedgeberg i don't know what printer you have, but I'm about to buy a HallOn sensor. You could modify the 3d printed case of it to fit most x-carriages, it works well with marlin and because it's a touch probe even with any build surface. <10$ for the kit. 28-Nov-18 04:51 AM E-beam evap is standard for optical coatings like anti-reflection and dichroic (interference) filters. Good for depositing a wide variety of stuff, including metal oxides, which don't sputter well. Usually have a carousel for several materials that can be deposited without breaking vacuum. The iridescent colors inside that chamber are normal, what isn't is the white powder. In the outside pic the thing sticking up to the right seems to be a substrate positioner, maybe a load lock too. Mostly what you see inside is three of what look like sputter guns. The evaporator is in the box on the bottom. The ion source is probably the cylinder pointing straight up at bottom right. https://www.dentonvacuum.com/products-technologies/ion-beam/ There is remarkably little to the "gun" in an e-beam evap, just a filament and magnets that steer the beam in an arc onto the material. This beam is usually scanned to spread out the heat. https://www.dentonvacuum.com/products-technologies/e-beam-evaporation/ 28-Nov-18 06:27 AM So in case anyone is curios as to why you should not put a MEMS device in an ultrasonicator... This is why. 28-Nov-18 06:27 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Scan_47.tifWed-28-Nov-2018_05-58-18-585C7.jpg 28-Nov-18 06:27 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Scan_71.tifWed-28-Nov-2018_05-58-26-347BC.jpg 28-Nov-18 06:47 AM I will also say I did a plasma cleaning on the first image and I think that really improved the quality a lot. All I did was stick an aluminum target in my sputter coater and if its not sputtering its cleaning... 28-Nov-18 06:52 AM (because it breaks all the small pieces?) 28-Nov-18 06:52 AM Yeah 28-Nov-18 06:52 AM look at those beams and paddles in the upper right corner, and just how deformed they are 28-Nov-18 06:53 AM Oh, right, now I get it. 28-Nov-18 06:53 AM I had thought that silicon was super durable when made into small mechanisms 28-Nov-18 06:53 AM The waffer is 28-Nov-18 06:53 AM The devices that are grown not so much... 28-Nov-18 08:01 AM Ahm. Well, now you know. XD 28-Nov-18 08:01 AM (me too) 28-Nov-18 11:42 AM Oof 28-Nov-18 11:42 AM Nasty 28-Nov-18 01:21 PM So 28-Nov-18 01:22 PM So, so 28-Nov-18 01:22 PM Btw, who's in for a chat this weekend? Last time was super fun. 28-Nov-18 01:28 PM I saw this earlier, and I was thinking like "why would anyone want this? You could just use an MCU" 28-Nov-18 01:28 PM yeah, sure! 28-Nov-18 01:28 PM But then I saw the tooling and realized 28-Nov-18 01:28 PM It looks great for lab automation 28-Nov-18 01:28 PM https://www.crowdsupply.com/digilent/openlogger 28-Nov-18 01:28 PM (everyone remember, there is the voiceposting for the ones who do not have a microphone, we can read you and answer) 28-Nov-18 01:28 PM Easy wireless lab automation 28-Nov-18 01:29 PM Woooooow 28-Nov-18 01:29 PM Wish i could use that! 28-Nov-18 01:29 PM I mean you prolly could for like, just about anything 28-Nov-18 01:29 PM Even if it's just for monitoring like, idk, an oven or something 28-Nov-18 01:30 PM (I mean I am useless with software or programming, wich this will probably require) 28-Nov-18 01:30 PM /thinks about building his own data logger...hmmmmmmmmm/ 28-Nov-18 01:43 PM No dude look at their web portal 28-Nov-18 01:43 PM They've got a thing preconfigured for management and reporting 28-Nov-18 01:43 PM Afaict it requires literally 0 dev 28-Nov-18 01:43 PM Oooh this is cool too: 28-Nov-18 01:43 PM https://www.crowdsupply.com 28-Nov-18 01:43 PM No 28-Nov-18 01:43 PM https://www.crowdsupply.com/openh/quasar 28-Nov-18 01:43 PM LTE serial modem 28-Nov-18 01:43 PM Power and control the data logger remotely methinks! 28-Nov-18 01:43 PM God I love CrowdSupply 28-Nov-18 01:51 PM Hey @hedgeberg , did you see my recommendation? 28-Nov-18 01:51 PM https://discordapp.com/channels/513115950501855256/513115950501855261/517280345712754692 28-Nov-18 02:02 PM @Leona I did! Haven't looked it up yet though! 28-Nov-18 02:31 PM Hmm @Leona so is it a switch-based sensor? Or a piezo-based sensor? 28-Nov-18 02:31 PM Hrrrrrm so the hallon and the bltouch look to be the 2 most common 28-Nov-18 02:31 PM Although I'm also curious about direct piezo contact sensors.... 28-Nov-18 02:31 PM All options to consider for after I get the glass bed on!! 28-Nov-18 02:31 PM Thanks for the info though! 28-Nov-18 02:41 PM I think it's a hall-effect sensor and a magnet in a retracting tip 28-Nov-18 02:41 PM (educated guess based on name and knowing there's a magnet in the kit) 28-Nov-18 03:23 PM Yeah, looks like this type of sensor is actually considered to be the worst? 28-Nov-18 03:23 PM Some people recommend servo + limit switch instead afaict 28-Nov-18 03:27 PM This is a cool one 28-Nov-18 03:27 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181128_142524-7F681.jpg 28-Nov-18 03:33 PM Oooooooh 28-Nov-18 03:33 PM What is it? 28-Nov-18 03:33 PM Mems? 28-Nov-18 03:42 PM I would say a gyroscope. 28-Nov-18 04:11 PM That makes sense, methinks? 28-Nov-18 04:22 PM Adaaaaaaam, shed some electrons on this subject. laughs at his sort-of-pun 28-Nov-18 04:58 PM It's actually something a bit different, a magnetic field sensor 28-Nov-18 04:58 PM It a kmz41 28-Nov-18 04:58 PM I don't entirely know how it works yet, honestly I just got it on digikey because I thought it might be interesting 28-Nov-18 04:58 PM Also it's easy to decap 28-Nov-18 05:03 PM OoooooOOOoooOOOOoooh. 28-Nov-18 05:03 PM SEM - ITTTT! 28-Nov-18 05:04 PM Working on it... 28-Nov-18 05:05 PM annoying kid voice Are we there yet?... 28-Nov-18 05:05 PM Are we there yet?... 28-Nov-18 05:23 PM Also for anyone curious about what I meant by 15 millikelvin at work... https://twitter.com/a_giorgio/status/1067532937934065666 28-Nov-18 05:28 PM Niiiiice. 28-Nov-18 05:31 PM dig that cryochandelier :3 28-Nov-18 05:35 PM Sia likes this 28-Nov-18 05:55 PM the manager actually joked about selling these as chandeliers lol 28-Nov-18 08:52 PM How many bits is it? 28-Nov-18 08:52 PM 8? 28-Nov-18 08:52 PM I actually have no idea on what qubit density is like at this point tbh 28-Nov-18 09:39 PM Uhm I don't know... The issue isn't just the number of qbits though 28-Nov-18 09:39 PM its also the noise level 28-Nov-18 09:39 PM so its a balance of lower noise and more qbits 28-Nov-18 09:39 PM they can make a 1000 qbit machine now if they wanted too 28-Nov-18 09:39 PM but it would be useless 28-Nov-18 09:39 PM I think the last thing they had online was like 6 qbits? maybe a bit more 28-Nov-18 11:50 PM Do you know what architecture it is? 28-Nov-18 11:50 PM Oh, it's a gate array I think 29-Nov-18 01:43 AM gate array? 29-Nov-18 01:43 AM those chips have cooper pair box based transmons connected via strip lines 29-Nov-18 01:43 AM the prob with 1000s of qubits on one chip is the connectivity 29-Nov-18 01:43 AM D:Wave sells computers with > 2000 qubits, but they are poorly (1-neighbourhood) connected, so they can only operate as a non-perfect quantum annealer 29-Nov-18 01:43 AM (a perfect quantum annealer would be equivalent to a universal quantum computer) 29-Nov-18 02:06 AM Helium-3 dilution refrigerator? 29-Nov-18 02:16 AM yes 29-Nov-18 02:42 AM you can play with them 29-Nov-18 02:42 AM they have machines for public use in the webs 29-Nov-18 02:42 AM up to 14 qubits 29-Nov-18 02:42 AM https://www.research.ibm.com/ibm-q/technology/devices/ and you can get an API key via https://quantumexperience.ng.bluemix.net/ for using the real machines with https://qiskit.org/ 29-Nov-18 03:49 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181128_140421-7545F.jpg 29-Nov-18 03:49 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181128_140345-7F0B1.jpg 29-Nov-18 03:49 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181128_140238-02D45.jpg 29-Nov-18 03:49 AM you really just hate ICs, don't you? 29-Nov-18 03:49 AM How to turn an epoxy package into a ceramic package 29-Nov-18 03:49 AM I love ICs, I don't like epoxy 29-Nov-18 03:52 AM :D 29-Nov-18 05:21 AM So the top pic is the end result? Does the ash crumble away then? I'm guessing the ash is mineral fillers, since I'd think pure epoxy would have very little ash. 29-Nov-18 05:22 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181128_140705-5A717.jpg 29-Nov-18 05:22 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181128_140750-D8288.jpg 29-Nov-18 05:22 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181128_140437-521BE.jpg 29-Nov-18 05:22 AM Yeah I drop it in water while it's hot and most of the time the MEMS devices split open 29-Nov-18 05:36 AM I heard you could laser etch with a mid power CO2 laser the epoxy casings, but haven't tried it yet. 29-Nov-18 06:38 AM https://www.youtube.com/watch?v=uaBzFvwBukg 29-Nov-18 06:47 AM Yeah I have seen that method before. Acid works really well though... 29-Nov-18 06:47 AM Also I just got a gryo decaped and damn 29-Nov-18 06:49 AM WANNA SEE ITTTTTT 29-Nov-18 06:49 AM jumps over his virtual shoulder 29-Nov-18 06:52 AM Hold on I kinda dropped it 29-Nov-18 06:52 AM This is pre cleaning/drop 29-Nov-18 06:52 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181129_061946-5DF47.jpg 29-Nov-18 06:53 AM Well, the front fell off 29-Nov-18 07:01 AM yummy yummy gyro. ^^ 29-Nov-18 07:11 AM I'm kinda at a loss on how to clean these things without an ultrasonicator 29-Nov-18 07:11 AM Anyone have any idea? 29-Nov-18 07:11 AM Or just how to make the sonicator weaker? 29-Nov-18 07:17 AM could a constant stream of solvent do the job? 29-Nov-18 07:18 AM That's what I have been working on, the problem is contamination in-between parts of the device 29-Nov-18 07:19 AM what does the contamination consist of? 29-Nov-18 07:19 AM is it the ash or something else? 29-Nov-18 07:19 AM Yeah 29-Nov-18 07:19 AM so dissolving it won't be easy 29-Nov-18 07:20 AM Correct 29-Nov-18 07:20 AM the mems itsef ist just Si / SiO2? 29-Nov-18 07:20 AM Maybe use a different liquid as a dampener, or add mass to the bottom. 29-Nov-18 07:20 AM Ultrasonicating just is perfect for this is the problem 29-Nov-18 07:20 AM (to the bottom of the liquid container, no the machine) 29-Nov-18 07:20 AM It's like what it was made for 29-Nov-18 07:21 AM exept that it isn't 29-Nov-18 07:21 AM ROFL 29-Nov-18 07:21 AM There, putting the finger in the wound 29-Nov-18 07:21 AM want some salt too? 29-Nov-18 07:21 AM Yeah and a bit of some conductive stuff probably aluminum 29-Nov-18 07:21 AM damn, so most acids are out 29-Nov-18 07:22 AM Yup 29-Nov-18 07:22 AM boiling in nitric acid maybe? 29-Nov-18 07:22 AM Though I would sacrifice the aluminum 29-Nov-18 07:22 AM In thinking slightly decoupled ultrasonicating is best bet 29-Nov-18 07:23 AM worth a shot, I'm guessing those chips aren't that expensive 29-Nov-18 07:24 AM Im going to try a more aggressive solvent wash first 29-Nov-18 07:25 AM what solvent are you using? 29-Nov-18 07:25 AM I'd expect the ash to be highly polar... 29-Nov-18 07:25 AM Ethonal 29-Nov-18 07:25 AM 95% 29-Nov-18 07:26 AM If it's filler, silica or alumina, etc., good luck dissolving that. 29-Nov-18 07:26 AM yep... 29-Nov-18 07:27 AM Yeah I'm not trying to dissolve it 29-Nov-18 07:27 AM I don't have anything that will 29-Nov-18 07:27 AM I'm going to try some detergent stuff, maybe that will break it free 29-Nov-18 07:35 AM Maybe squirt it with a syringe or other squirty thing? 29-Nov-18 07:36 AM That's what I'm doing. I think u just need a bit more pressure than what I can do by hand 29-Nov-18 07:41 AM Hm 29-Nov-18 07:41 AM High pressure Mr clean is working 29-Nov-18 07:41 AM That's cool 29-Nov-18 07:59 AM I'm using a green liquid now so you know I'm scienceing 29-Nov-18 07:59 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181129_075826-E42D2.jpg 29-Nov-18 07:59 AM drop some dry ice in it and make a video 29-Nov-18 08:03 AM Im also surprised by how well a sputter coater with aluminum in it is working as a plasma cleaner 29-Nov-18 08:03 AM why dosen't the Al sputter? instead of cleaning? 29-Nov-18 08:03 AM oxide layer? 29-Nov-18 08:03 AM Aluminum just takes a massive amount of time to sputter 29-Nov-18 08:03 AM Something like 1/100th or more than gold 29-Nov-18 08:04 AM wow, ok 29-Nov-18 08:09 AM This is looking really good 29-Nov-18 08:09 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181129_080824-134FF.jpg 29-Nov-18 08:09 AM Also @Nixie in case you were curious how many of those cases I have... 29-Nov-18 08:09 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181129_081115-7B2F6.jpg 29-Nov-18 09:43 AM 29-Nov-18 09:47 AM what are those? 29-Nov-18 09:51 AM Boxes for carrying SEM samples. 29-Nov-18 09:51 AM he gave me two, and I was worried they where one too much. 29-Nov-18 09:52 AM oh, ok 29-Nov-18 01:48 PM Damn 29-Nov-18 01:48 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181129_134758-9C53F.jpg 29-Nov-18 01:48 PM @Nixie 29-Nov-18 01:51 PM That is a sweet sweet...thing 29-Nov-18 07:34 PM Woo final part of payment secured! I can finally move on to getting the plates manufactured, pulling vacuum, and working towards starting to get EXEDA operational. Just in time too, as I finalized the first vacuum simulations today. Vacuum design of the pumping station is verified and better than anticipated. The simulations are really amazing at looking at the behavior of a vacuum system, just an incredible amount of information and insight, in addition to validating all those hours calculating everything out by hand. Getting close to finally wrapping up a years worth of vacuum engineering R&D. 29-Nov-18 07:49 PM Yay :D 29-Nov-18 08:14 PM @Applied_Ion what are you working on? 29-Nov-18 08:14 PM I've seen your stuff retweeted a bit on Twitter and I've seen you talking here but I'm bad at paying attention 29-Nov-18 08:30 PM @hedgeberg The stuff I've been posting on twitter for the past couple of weeks have been some old projects I've worked on in the past, sharing ways to do some diy science at home for very cheap, like the electrospinning and gliding arc discharge plasma. Next week will wrap up gliding arc and move into nontransferred thermal plasma torches, then I will get back to posting on vacuum systems. The vacuum stuff I am doing consists of 3 major projects: micro propulsion for small satellites, a small chamber for miniaturized intense beam systems, and my big project, EXEDA. Of the three, EXEDA has been mostly under wraps, with hints dropped here and there. I will most likely make my major announcement for it after New Years if I finish all my prep work in time. I won't reveal too much on it for now, but I will say that as far as I am aware, this will be the first of its kind at the maker level. There are many of these systems around the world at major institutes, but no maker has tackled it before independently. If it works, it will be a legitimate high power/high energy research class device, and my hopes are that it will open the door for many exciting high power physics experiments not done at the maker level before. And it can be accomplished with parts on the surplus market, as well as homemade components. The principles are also scalable for a range of low and high power devices. I want to lower the barrier of entry for particle beam physics and bring the possibility of research in this field to the maker community. 29-Nov-18 08:31 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181129_203040-46BAA.jpg 29-Nov-18 08:31 PM Oh? I'm curious now, I did a lot of instrumentation physics in my undergraduate/graduate time 29-Nov-18 08:31 PM @Applied_Ion I'd be super interested in any crumbs you could drop re: exeda, or if there's anything i could do to assist 29-Nov-18 08:39 PM @hedgeberg thanks! There is certainly a lot of work to be done, and I can't wait to see the applications and experiments the maker community will come up with using a device like this. I'll be making more announcements on here and twitter for sure and keep everyone updated. Right now a crumb for this is that it is related to high power particle beams/accelerator technology. The specifics though will be for another day! 29-Nov-18 08:40 PM Ooooh are you making a DIY collider??? 29-Nov-18 08:40 PM Sorry you wanna keep it a secret I'll stop asking >.< 29-Nov-18 08:40 PM I get excited and then Im bad at shutting up sorry 29-Nov-18 08:44 PM Not a collider, but I garauntee it's not like any other beam device made by other makers. The shear number of experiments you can do with it is incredible though, a true jack knife in the accelerator world. The accelerators built in the hobbyist community so far are small toys compared to this. No worries about asking lol. I will be making this build open source, so the details will be available and fully intensive 29-Nov-18 09:06 PM Fair enough! I'll try to stay patient! 29-Nov-18 09:09 PM The actual device itself is very simple and even a bit underwhelming at first glance, but when you dive into the literature and see its uses, it is incredibly exciting. And it can be run from your wall outlet too, no need for huge power infrastructure (although shielding is an absolute must, it's getting into serious levels of yields, especially x rays) 29-Nov-18 09:09 PM Question: does zinc plated stainless steel also have the problem of galling? 29-Nov-18 09:09 PM Hmmmmmmm is it a cyclotron???? 29-Nov-18 09:11 PM Nope, no cyclotrons. Too weak for my taste, and requires unrealistic power with a huge magnet that's out of reach for most people. 29-Nov-18 09:11 PM If it is then I'm super excited because I've been thinking about trying to do IC imaging using reflected X-rays for a while based on that paper that used the giant cyclotron to do nanoscale imaging 29-Nov-18 09:11 PM Oh huh, well now I'm very interested considering I don't know much about high power x-ray sources past cyclotrons 29-Nov-18 09:12 PM While cyclotrons are great learning devices, the energy from amateur ones is abysmal for the amount of input you put in, especially to power the magnet 29-Nov-18 09:12 PM Most of my work was restricted to the stuff needed for materials growth so this is a region I have never delved into and its definitely picqued my curiosity 29-Nov-18 09:12 PM This thing is a very, very niche device in its field, but used a lot at major national labs 29-Nov-18 09:12 PM Makes sense, what kind of power/frequency/density are we talking about? 29-Nov-18 09:12 PM Hmmmmmmm 29-Nov-18 09:12 PM When did it start being used? If it was used more than 5 years ago there's a chance Ive heard about it and forgotten 29-Nov-18 09:12 PM Question, what's your education level and day job? 29-Nov-18 09:12 PM Also, question for anyone: does zinc-coated stainless steel also have the galling problem? Or is it just pure stainless-on-stainless contact? 29-Nov-18 09:21 PM Oh it's very old. For my device, which is still on the small side, if I get the system efficient, we are talking peak beam powers in the hundreds of MW range (depending on the experiment.) I have a bs in ee, and work as an ee for an accelerator facility. Because of my level not being a phd, I know academia in this field won't take me seriously, and i havent had any interest discussing its potential with others in the field for use to make accelerator physics more accessible, why I am putting a full blown engineering effort into it. But I know this could open up many doors for makers, and allow for new experiments at this level. My passion is beams, plasma, pulsed power, etc, and I have been studying these areas for a long time now. My desperation to build a high power system with little resources led me to search into the deep, dark, very old, and super niche fields to find my answer. 29-Nov-18 09:21 PM And for your other question, pure stainless on stainless is a galling issue. If one side is zinc coated, the risk is reduced 29-Nov-18 09:27 PM Ok, nice re: zinc, was worried for a second b/c I accidentally ordered pure stainless nuts 29-Nov-18 09:27 PM And yeah, I'm also not a PhD. I sort of started one but it died hard and I'm kinda glad it did. Being taken seriously by academia is overrated anyway and I'm really excited by the rapidly growing trend of open laboratories. 29-Nov-18 09:30 PM Definitely, I'm not worried about being taken seriously by them, though it makes it tough to do everything 100% myself. Takes more time, but I'll be more of an expert at the end. 29-Nov-18 09:30 PM I'm not interested in pursuing a phd, too many fun subjects to explore than being bogged down by 1 29-Nov-18 09:31 PM For sure. For what it's worth I do work in a sort of pseudo-academic-but-not-really environment? So if there are resources I can provide access to let me know 29-Nov-18 09:31 PM And I can at least try 29-Nov-18 09:31 PM But re: a lot of work on your own, I'm always happy to assist if needed. Can't guarantee it'll be useful help, but yknow 29-Nov-18 09:33 PM Defintely! The lab I work at is also rather unique, we don't really follow a conventional system, even though technically part of academia. Very hands on diy maker group I work with here 29-Nov-18 09:33 PM I'm putting probably on average 5 hours a day on this, plus the full time job, trying to get all the preliminary stuff sorted, published, etc. Lot of just grunt work - cad, write ups, research, etc on the small things so far. Haven't started the actual design for exeda yet, just the vacuum stuff from scratch, but I will be finally starting soon. Already collected and read hundreds of papers and several text books on the subject, so I got lots of resources to sift through for final details. 29-Nov-18 09:52 PM For a moment a flash in my brain happened where I wondered if we maybe worked at the same place 29-Nov-18 09:52 PM That would be weird 29-Nov-18 10:10 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Scan_17.tifThu-29-Nov-2018_22-07-57-99CB6.jpg 29-Nov-18 10:10 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Scan_30.tifThu-29-Nov-2018_22-07-41-FCA60.jpg 29-Nov-18 10:10 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Scan_32.tifThu-29-Nov-2018_22-07-42-53403.jpg 29-Nov-18 10:10 PM These MEMS gyroscopes are pretty damn cool 29-Nov-18 10:10 PM To get these I had to repair the digital scan rotation so I could get this perspective on the chips. My SEM stage only tilts in on axis so getting shots with it tilting away from the perspective of the view means the raster scan has to be rotated. 29-Nov-18 10:13 PM Amazing clarity, Adam. 29-Nov-18 10:13 PM Thanks 29-Nov-18 10:13 PM Im getting around to fixing a lot of little things on my acquisition system, like having actual magnifications in the info bar. 29-Nov-18 10:47 PM Anyone here ever played around with pyroelectric fusion? 29-Nov-18 10:54 PM 29-Nov-18 10:54 PM Might use it as screensaver or something 29-Nov-18 11:49 PM Good god that aspect ratio on those MEMS gyros 29-Nov-18 11:49 PM gorgeous 29-Nov-18 11:49 PM @goopypanther i have had thoughts about this off and on 30-Nov-18 12:00 AM So, y'all know those meal kit delivery services? 30-Nov-18 12:00 AM Like blue apron? 30-Nov-18 12:00 AM We started getting one of those, and uh 30-Nov-18 12:00 AM They have these insulated cardboard layers inside to keep things cool, so it's cardboard + a reflective metal later 30-Nov-18 12:00 AM *layer 30-Nov-18 12:00 AM Oops 30-Nov-18 12:01 AM Sounds cool/warm xD 30-Nov-18 12:01 AM I have attempted to make a thermal enclosure out of it for my printer 30-Nov-18 12:01 AM Look at this nonsense 30-Nov-18 12:01 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181130_025933-7B80C.jpg 30-Nov-18 12:01 AM It's going badly but in a fun way 30-Nov-18 12:01 AM I think the insulated metal spray they use vaporizes a bit tho, so I think I've been inhaling some carcinogens 30-Nov-18 12:01 AM So uh 30-Nov-18 12:01 AM Whoops 30-Nov-18 12:03 AM Beeee carefuuul 30-Nov-18 12:03 AM But it's kinda fun, hopefully I'll be able to demo a significant difference in shrinkage between layers if this works 30-Nov-18 12:03 AM 30-Nov-18 12:03 AM I figure this should keep things warm, yeah? 30-Nov-18 12:03 AM The gyro is electrostatically actuated/sensed? 30-Nov-18 12:03 AM You can also do a sandwich of insulating layers yourself if this doesn't work. 30-Nov-18 12:03 AM @Leona I shall have a knurler as christmas present. 30-Nov-18 12:10 AM Congrats! 30-Nov-18 12:28 AM Love that Bosch DRIE goodness 30-Nov-18 12:28 AM @Applied_Ion it’s not a Z-pinch you’re working on is it? 30-Nov-18 01:47 AM @AdamMcCombs what's the resolution of the ADC & DAC? 30-Nov-18 03:28 AM I'm going to do a totally experimental machining livestream. Like, right now. 30-Nov-18 03:30 AM cool, link? 30-Nov-18 03:30 AM no, wait, let me get a coffee first 30-Nov-18 03:40 AM ok, now you can stream 30-Nov-18 03:40 AM got it from twitter: https://www.pscp.tv/w/1ynKOOeERPOKR 30-Nov-18 05:03 AM the part is too stubby. I don't like it. :/ 30-Nov-18 05:03 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20181130_140403-8CF3D.jpg 30-Nov-18 05:19 AM @goopypanther while I haven't worked with it directly our lab did publish work on pyroelectric fusion. The yields are small so you would need a very good detector setup, but it can be used for xray production as well. The setup is pretty simple too. If you can find a source if cheap lithium tantalate crystals, a z-cut disk a few cm in diameter by a few cm thick, that's the critical part. Heater is easy, and vacuum is only around maybe 10^-4 torr or so 30-Nov-18 05:19 AM @a_quiet_scientist , nope, not z-pinch device either (though a friend of mine is building his own DPF himself) 30-Nov-18 06:18 AM V2! 30-Nov-18 06:18 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181130_151555-058E2.jpg 30-Nov-18 08:56 AM Anyways, @AdamMcCombs do you think you could ask Ben Krasnow about his ceramic pieces? 30-Nov-18 09:06 AM yeah, ask him 30-Nov-18 09:34 AM About ceramic for vacuum service? 30-Nov-18 10:09 AM @Nixie sounds like my kinda person esp with the sofa 30-Nov-18 12:46 PM @Zhang 30-Nov-18 12:46 PM @AdamMcCombs , yes, I mean, he can test it in his own chamber or send a test piece to someone of us to test. 30-Nov-18 07:45 PM I spent the day working with RFNA, HF, and sulphuric. Hopefully there will be some interesting results under the scope to show for it. 30-Nov-18 07:45 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181130_181108-6B864.jpg 30-Nov-18 07:53 PM I'll ask Ben about the ceramic stuff too 30-Nov-18 11:19 PM god, everyone's doing decapping these days 30-Nov-18 11:19 PM @AdamMcCombs did you mill down the chip ceramic first? 30-Nov-18 11:45 PM Decaping is some scary stuff 30-Nov-18 11:45 PM I was only doing smd epoxy stuff so no need to mill 01-Dec-18 12:35 AM I'll do "capping" someday. 01-Dec-18 02:45 AM I still think it would be possible to make a CNC CMP precision polisher that you could use to do safer decaps 01-Dec-18 03:27 AM Cmp? 01-Dec-18 07:31 AM Joined the server. 01-Dec-18 09:19 AM Welcome! 01-Dec-18 10:14 AM Chemical Mechanical Planarization 01-Dec-18 10:14 AM ok, to late 01-Dec-18 10:59 AM Not too late 01-Dec-18 10:59 AM Hm...not sure if cmp will be the best process for that (but I'm no expert) 01-Dec-18 11:13 AM I mean the acid works really well... 02-Dec-18 12:29 AM Yeah but the acid scary :( 02-Dec-18 01:23 AM @qualia feel free to hit me with a million kicad questions if you have them, I can try to make up for the lack of good content 02-Dec-18 01:23 AM i don't have any specific questions other than like i need to learn workflow and keybindings 02-Dec-18 01:25 AM Keybindings you can mostly learn from tooltips 02-Dec-18 01:25 AM The workflow is pretty decent so long as you don't have to add any weird footprints 02-Dec-18 01:25 AM But once you do it can get a bit painful 02-Dec-18 01:25 AM It's basically: design schematic using w/e parts 02-Dec-18 01:25 AM -assign a footprint for each part 02-Dec-18 01:25 AM (if you need to add custom footprints, this is where, and it's honestly awful imo) 02-Dec-18 01:25 AM -generate netlist and spawn new pcb layout project project 02-Dec-18 01:25 AM -design your edge.cuts layer with some really thin line 02-Dec-18 01:25 AM -import netlist and footprints 02-Dec-18 01:25 AM And it will then go ahead and drop all your footprints for all your assigned parts into the PCB layout 02-Dec-18 01:25 AM And then it's just placing and routing them 02-Dec-18 01:25 AM Oh and you'll want to enable the ratsnest I think? 02-Dec-18 01:25 AM Since that's the easiest way to lay out? 02-Dec-18 01:25 AM And I guess run lvs when you're done? But I honestly don't remember if kicad actually has a real lvs... 02-Dec-18 01:25 AM I feel like they must, but I'm not sure. I know I've wound up with situations where I thought I was matched to schematic and then it wasn't when I received my parts, but that was usually because of bad polygon pours 02-Dec-18 01:25 AM Idk, @qualia that's the, like, overview? Does that help at all? 02-Dec-18 01:25 AM I kinda just infodumped without asking if that was what you actually needed and I'm realizing that's bad 02-Dec-18 01:25 AM I'm trying to remember anything I can that I ran into that caused me problems 02-Dec-18 01:25 AM I think honestly the best thing to do might be to just try it for a bit and then when you get stuck ask someone for help? That's why I did when all my googling for good tutorials turned up nothing 02-Dec-18 02:22 AM yeah i think i just need to practice and drudge through a while until i pick up speed 02-Dec-18 02:22 AM tho the infodump is useful c: ty for sharing 02-Dec-18 03:33 AM So my uh... My bad insulation enclosure is working.... Upsettingly well I think 02-Dec-18 03:33 AM It's 10 degrees C above the temperature of the surrounding room in there 02-Dec-18 03:33 AM At least, that's just what I'm seeing on some of the cardboard that's near one of the air outlets on the top 02-Dec-18 03:33 AM So like 02-Dec-18 03:33 AM Yay? 02-Dec-18 03:39 AM Yoy! 02-Dec-18 03:39 AM My cetus with PLA doesn't give much trouble with printing other than clogged nozzles from time to time. 02-Dec-18 03:40 AM woohoo, cetus club! 02-Dec-18 03:40 AM o/ 02-Dec-18 03:41 AM yeah, the printer's great, if you've got the MK1 extruder 02-Dec-18 03:41 AM my MK2 one crapped out a while ago, got a free MK1 replacement, been working great ever since 02-Dec-18 03:50 AM My monoprice printer really isn't great. I'm trying to make it a lot better 02-Dec-18 03:50 AM Think the thing I really need to do after adding an enclosure is replacing the electronics 02-Dec-18 03:53 AM but...but...where's my highfive?...cries 02-Dec-18 03:55 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/FLIR0067-09B3A.jpg 02-Dec-18 03:55 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/FLIR0068-49AA7.jpg 02-Dec-18 03:55 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/FLIR0066-A06E5.jpg 02-Dec-18 03:55 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/FLIR0069-27337.jpg 02-Dec-18 03:55 AM Check it 02-Dec-18 03:55 AM I think I have a V2, hasn't let me down. 02-Dec-18 03:55 AM That's with like, a weak vent 02-Dec-18 03:55 AM Nice hotshots! 02-Dec-18 03:56 AM The cardboard is registering 26.1 C next to a vent pretty far from the center of the enclosure 02-Dec-18 03:56 AM The rest of the room is like, about 18-20C 02-Dec-18 03:56 AM Nice knowing this nonsense worked tbh 02-Dec-18 04:13 AM if it worked, it's no nonsense. Maybe just unpolished. 02-Dec-18 06:14 AM Well, it worked at raising the temperature of the print-environment. It might still not have an effect on layer adhesion 02-Dec-18 08:34 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/1dec18_run-4901F.pls 02-Dec-18 08:34 AM Does anyone use PRA for spectroscopy? It’s the software you can use with Gamma Spectacular gear, I’m trying to use it for neutron detection 02-Dec-18 08:34 AM But I have no idea what a neutron pulse looks like. I’ve tried getting a stable deuterium plasma and then removing my 3 Helium tube from the moderator but it doesn’t seem to have any noticeable effect on signal counts 02-Dec-18 08:36 AM could you please just upload a screenshot instead of the file? 02-Dec-18 08:36 AM Yeah hang on a few mins I’ll get something 02-Dec-18 08:37 AM have you done your noise floor stuff? 02-Dec-18 08:37 AM You also have to tune your input and whatnot 02-Dec-18 08:43 AM you've got to look out for a spectrum like this: https://www.researchgate.net/profile/Matteo_Maspero/publication/260887128/figure/fig12/AS:614135989559311@1523432838512/Expected-pulse-height-spectrum-in-a-3-He-tube-The-two-steps-in-the-spectrum-are-caused.png 02-Dec-18 08:43 AM that indicates a good, working He3 tube 02-Dec-18 08:43 AM depending on tube geometry the peaks are more or less defined, but you can always see at least one step 02-Dec-18 08:49 AM do you guys build your own neutron detectors? 02-Dec-18 08:49 AM I do ^^ 02-Dec-18 08:49 AM @GigaSquirrel cool 02-Dec-18 08:49 AM very much 02-Dec-18 08:50 AM @GigaSquirrel do you have a recipe for them? 02-Dec-18 08:50 AM shielding 02-Dec-18 08:50 AM as in a step by step build guide for nappels 02-Dec-18 08:51 AM I assume you want to buy a detector tube and are looking for information on how to use it properly? 02-Dec-18 08:51 AM instead of building your own tube 02-Dec-18 08:51 AM i "know" different design approaches in theory, but is feasile for a low-tec approach? 02-Dec-18 08:51 AM definately 02-Dec-18 08:52 AM no DIYse would be very nice 02-Dec-18 08:52 AM all you have to do is detect a 5 mV dip in a 3 kV rail 02-Dec-18 08:52 AM ok 02-Dec-18 08:53 AM http://www.fusor.net/board/viewtopic.php?f=13&t=12474&sid=678fa0c9f2557203546aab2ff04a30d5 This is a small writeup about the russian SNM tubes 02-Dec-18 08:53 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/ratetime1stdec18-A41F0.png 02-Dec-18 08:54 AM @to congrats, you've got a good noise generator 02-Dec-18 08:54 AM @GigaSquirrel tnx 02-Dec-18 08:54 AM Uh I don’t think I’ve done noise floor properly. Left it running for like 20 mins a couple times to see what showed up 02-Dec-18 08:54 AM Have you gone to energy domain instead of time? 02-Dec-18 08:54 AM Lots of noise wonderful 02-Dec-18 08:54 AM @AdamMcCombs looks like it 02-Dec-18 08:55 AM It's in pulse v Time 02-Dec-18 08:55 AM Yep 02-Dec-18 08:55 AM @N00N If you've got any specific questions just ask 02-Dec-18 08:55 AM You want to see something else? 02-Dec-18 08:55 AM Guess what I really want is to know what to discriminate for/against 02-Dec-18 08:56 AM View>whatever one does energy binning 02-Dec-18 08:56 AM Ok 1 sec 02-Dec-18 08:56 AM I don't remember the exact name 02-Dec-18 08:56 AM I’ll get it 02-Dec-18 08:57 AM @GigaSquirrel i guess, i will have plenty of questions in the near or not-so-near future 02-Dec-18 08:58 AM great! 02-Dec-18 08:59 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/01dec18_pulseheight-80A9F.png 02-Dec-18 08:59 AM Pulse height histogram 02-Dec-18 09:00 AM hmmm 02-Dec-18 09:00 AM everything below 7 is noise 02-Dec-18 09:00 AM what'S the diameter of your tube? 02-Dec-18 09:02 AM I think the discriminators need a bit of work 02-Dec-18 09:04 AM @AdamMcCombs how many bit does your ADC on the SEM sensors have? 02-Dec-18 09:04 AM 12 or 14 or something like that? 02-Dec-18 09:04 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-37CA3.jpg 02-Dec-18 09:04 AM 13.5mm tube diameter 02-Dec-18 09:05 AM @to was that expensive? 02-Dec-18 09:05 AM Smallish 02-Dec-18 09:05 AM The sem itself is 100% analog 02-Dec-18 09:05 AM It’s actually on loan from a guy 02-Dec-18 09:05 AM @AdamMcCombs yeah, i mean the capture unit 02-Dec-18 09:05 AM 16 bit 02-Dec-18 09:05 AM So I’m not sure how much it costs new 02-Dec-18 09:05 AM @AdamMcCombs okay 02-Dec-18 09:05 AM @AdamMcCombs ever tried EBL with that rig? 02-Dec-18 09:05 AM i guess your ADC/DAC interface is able to control x/y? 02-Dec-18 09:05 AM electron beam lithography i mean 02-Dec-18 09:06 AM Not with the current setup 02-Dec-18 09:06 AM hm ok 02-Dec-18 09:07 AM It's a very proprietary magic box 02-Dec-18 09:07 AM I'm starting development on a FPGA one soon though 02-Dec-18 09:07 AM hm, ok, wit that diameter the wall effects won't be very pronounced 02-Dec-18 09:08 AM ok, i guess i glue a generic ADC/DAC on a FPGA too and use a microcontroller with USB 02-Dec-18 09:08 AM ok wow, 20 bar 02-Dec-18 09:08 AM FPGA because of the digital interface of the most ADC & DAC 02-Dec-18 09:08 AM 20 bar of He3? wow 02-Dec-18 09:09 AM in that case you should definately see wall effects 02-Dec-18 09:09 AM Fpga to do faster scan patterns 02-Dec-18 09:09 AM btw, what's the current price for He3 per i dunno gramm? ^^ 02-Dec-18 09:10 AM way too much 02-Dec-18 09:10 AM @AdamMcCombs yeah, but i only need x & y, i guess the bottleneck is the bandwidth of the deflection unit (and the wire-ing path to it) :3 02-Dec-18 09:10 AM Yeah micros can do it 02-Dec-18 09:10 AM Sam built one 02-Dec-18 09:10 AM so i guess there is no 10GHz deflection bandwith, it's more like i dunno 100MHz max? 02-Dec-18 09:10 AM For ebeam 02-Dec-18 09:10 AM if you really want to build a neutron detector from the bottom up do yourself a favour and use boron 02-Dec-18 09:11 AM Static deflection setups can do some magic stuff 02-Dec-18 09:11 AM hm ok 02-Dec-18 09:11 AM but after all i need a relatively slow beam to get the right dosage on the resist, right? 02-Dec-18 09:12 AM I don't know mine, but you do a calibration that cheats bandwidth and increase magnitude as frequency increases 02-Dec-18 09:12 AM Yeah 02-Dec-18 09:12 AM Sam literally feeds his with g code 02-Dec-18 09:12 AM hehe ok 02-Dec-18 09:12 AM What scopes do you have? 02-Dec-18 09:13 AM Sooo what should I do to sort this out 02-Dec-18 09:13 AM Need to calibrate with a neutron source or can I reliably screen for non-noise somehow? 02-Dec-18 09:14 AM a neutron source would definately make things easyer 02-Dec-18 09:15 AM @AdamMcCombs i have one hitachi FESEM, one cambridge stereoscan and 3 ISI 02-Dec-18 09:15 AM but i'vent reworked the hitachi yet 02-Dec-18 09:15 AM got it in parts and declared as defect 02-Dec-18 09:16 AM Have emailed profs at uni to see if anything can be done 02-Dec-18 09:16 AM good luck! 02-Dec-18 09:16 AM But would like if I could screen for noise without having to do that 02-Dec-18 09:16 AM @to profs of your university? 02-Dec-18 09:17 AM Yeah 02-Dec-18 09:17 AM ok 02-Dec-18 09:17 AM Also I got this old Boxford CNC lathe 02-Dec-18 09:17 AM your neutron events will be in a certain pulse height range, with a window comparator you can reject most noise 02-Dec-18 09:17 AM would be funny to ask as a complete stranger 02-Dec-18 09:17 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-6CDF3.jpg 02-Dec-18 09:17 AM "gimme access to your neutron-source, pls!" 02-Dec-18 09:17 AM worked for me 02-Dec-18 09:17 AM brb, dinner 02-Dec-18 09:18 AM @GigaSquirrel where? :3 02-Dec-18 09:18 AM Haha yea @N00N though people tend to be quite open to interested outsiders! 02-Dec-18 09:19 AM @to ah, hm, okayyyyy 02-Dec-18 09:19 AM That CNC large doesn’t turn on but I’d like to get it functional somehow 02-Dec-18 09:19 AM Lathe^ .. not sure where to start 02-Dec-18 09:48 AM @N00N Local particle accelerator ;) 02-Dec-18 09:48 AM just mace sure to contact either someone high up or the radiation safety... guy 02-Dec-18 09:48 AM good thing they're the same persone at the accelerator here 02-Dec-18 09:53 AM hum, ok the PTB could have one in my neighbourhood (particle accelerator) 02-Dec-18 09:56 AM haha, oh god, I can't read "PTB" without thinking "physikalisch technische badeanstal" 02-Dec-18 09:56 AM lol 02-Dec-18 09:57 AM Ok I'm back my pellet stove need some work and I wanted to be warm 02-Dec-18 09:57 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181202_093107-2D656.jpg 02-Dec-18 09:57 AM I don't think they have an accelerator, but they have some neutron sources for sure 02-Dec-18 09:57 AM they had a pool afaik but it was a "Spent Fuel Pool" for their little reactor 02-Dec-18 09:57 AM The s3a is probably the best bet for ebl 02-Dec-18 09:57 AM Remove the c1 apurture and probe current goes through the roof 02-Dec-18 09:58 AM @AdamMcCombs tnx for the tip 02-Dec-18 09:58 AM @GigaSquirrel no tiny little accelerator? 02-Dec-18 09:59 AM I don't know ^^ 02-Dec-18 09:59 AM the accelerator here only has a neutron source because they have to test the neutron detectors along the beampipe 02-Dec-18 10:01 AM One of the "milk can" sources? 02-Dec-18 10:03 AM video / photos are coming, one sec 02-Dec-18 10:03 AM nvm, got it on twitter 02-Dec-18 10:03 AM https://twitter.com/GigaBecquerel/status/1040312690785378304 02-Dec-18 10:03 AM https://twitter.com/GigaBecquerel/status/1032294603695816705 02-Dec-18 10:11 AM @AdamMcCombs What do you mean by "milk can source"? 02-Dec-18 10:13 AM There are these sources that look exactly like a milk can that have just an hv feedthrough on one end. Apply power and get some crazy large amount of nuetrons out 02-Dec-18 10:13 AM Accidentally activated glass with one 02-Dec-18 10:14 AM ah, the ones I've seen were all straight tubes 02-Dec-18 10:14 AM oh wow O.o 02-Dec-18 10:14 AM 13 mev as well... 02-Dec-18 10:14 AM great, now I want one... 02-Dec-18 10:14 AM but no, I've only got access to AmBe and RaBe 02-Dec-18 10:15 AM Still those are fun 02-Dec-18 10:15 AM maybe even some Cf 02-Dec-18 10:15 AM yep 02-Dec-18 10:15 AM too bad i wasn't allowed to do any activation experiments with them yet 02-Dec-18 10:15 AM the sources must not leave the rad working area and no sources must be outside of the locked safe when you leave the working area 02-Dec-18 10:17 AM Where's the fun in that 02-Dec-18 10:17 AM and I don't really want to stand next to that kind of dose rate for a prolonged amount of time 02-Dec-18 10:17 AM dunno, in living past 50? 02-Dec-18 10:18 AM Eh fair 02-Dec-18 10:19 AM that's why I'm building the fusor 02-Dec-18 10:19 AM Sources that can be turned off are nice 02-Dec-18 10:20 AM that's the selling point for me ^^ 02-Dec-18 10:20 AM What shield are you going to be using beyond r2? 02-Dec-18 10:20 AM currently working on a way to dissolve Gd in paraffine wax 02-Dec-18 10:20 AM and also lead 02-Dec-18 10:20 AM but that dosen't do much for the neutrons ^^ 02-Dec-18 10:21 AM Cadmium? 02-Dec-18 10:21 AM gadolinium 02-Dec-18 10:21 AM way bigger cross section and not nearly as toxic 02-Dec-18 10:21 AM I mean are you going to be doing cad plates 02-Dec-18 10:21 AM Ah 02-Dec-18 10:21 AM not if the Gd shield works 02-Dec-18 10:22 AM Running gant sims? 02-Dec-18 10:22 AM no sims at all, just calculating by hand and carefull measurements 02-Dec-18 10:22 AM currently I'm working on the metrology and shielding, that's why I wanted to get my hands on the neutron source, so I could test them in a safe environment with known sources 02-Dec-18 02:20 PM What type of neutron yields are you expecting or aiming for with your fusor? 02-Dec-18 02:26 PM as high as possible, but currently I jsut want any neutrons ^^ 02-Dec-18 02:34 PM Any neutrons are easy. What type of power supply you got to run it? 02-Dec-18 02:34 PM Seems on average typical amateur fusors get several 100s of kilo neutrons per second, well conditioned ones hit 10^6. I think there are only one or two that hit 10^7, and these were run with some pretty high input voltage and current in more of a lab setup. 02-Dec-18 02:37 PM 30 kV 100 mA by glassman 02-Dec-18 02:43 PM Nice! a bit on the lower end on the voltage side but definitely enough to get easily measured neutron flux, and plenty of current for sure, you will get neutrons no problem with that. Well conditioned you could probably peak into the 10^6 based on others reported efforts I think. 02-Dec-18 02:45 PM that would be great! 02-Dec-18 02:45 PM but currently I'm working on shielding and neutron detection 02-Dec-18 02:45 PM so the actual fusor part is kinda being left behind right now 02-Dec-18 02:46 PM Yeah, doesn't do much good to have a fusor you can't run safely or detect stuff with 02-Dec-18 02:46 PM Shielding is my biggest concern, not sure how I am going to tackle it yet 02-Dec-18 02:46 PM Low power operation is easy, but if I want to run at full power it's going to be tough to deal with 02-Dec-18 02:48 PM I'm gonna shield it properly anyway, regardless of the actual power 02-Dec-18 02:48 PM ALARA and stuff 02-Dec-18 02:48 PM It would be Interesting to talk Kizmox in to fusor and other more "physics" kind of stuff. He has tons of toys like thuis one https://www.youtube.com/watch?v=dLK8E3y447k 03-Dec-18 05:06 AM XDD. Invite him to the server or something. 03-Dec-18 07:29 AM Joined the server. 03-Dec-18 07:38 AM Hello! 03-Dec-18 10:03 AM I noticed that with my hollow cathode setup I was getting more vivid colors on metal that was grounded (serving as anode) than on what was supposed to be the substrate. Both stainless hardware and copper heatsink. So I tried using a piece of stainless as substrate and giving it + bias so that it intercepts basically all of the anode current. This gave a very nice effect with the Ti cathode, giving a noticeable color much faster. 03-Dec-18 10:03 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181203_125658582-C9543.jpg 03-Dec-18 10:03 AM It also seemed than the effect was stronger with no deliberate air injection, just argon. My guess is still that this is Ti oxide rather than oxide of the substrate, mostly because the color is so vivid. There is probably enough O2 from leakage, water vapor, argon impurity, etc. In standard sputtering, cathodic arc, etc., substrate bias is always negative AFAIK. 03-Dec-18 10:11 AM do yo do multiple cleaning/flushings with argon, or just pump down then refill? 03-Dec-18 10:12 AM My aluminum pot and baseplate do not seem to work at all well as anodes, I guess because they build up a more insulating oxide. I get much more anode glow on the stainless fittings and copper than the aluminum. 03-Dec-18 10:23 AM I have not been doing Ar purges up eg. atmosphere, but with my use of glow bar as a pumping aid I do do some cycling from 1e-4 to 500e-3. But I also deliberately admitted air at low levels during this run when trying different things, so it might have been stuck in surfaces or whatever. 03-Dec-18 11:20 AM @qualia Here is the min order stuff for ortech 03-Dec-18 11:20 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-CEA0C.png 03-Dec-18 11:23 AM ROFL 175$ 03-Dec-18 11:25 AM I'm pretty sure I've seen ceramics distributors that don't have a min like that 03-Dec-18 11:25 AM I will see if I can find the one I was looking at, it's been a while 03-Dec-18 11:25 AM I need ceramic tuning for some of my experiments 03-Dec-18 11:26 AM Yeah im sure they are out there. I used ortech for some custom stuff some time ago and they did great work 03-Dec-18 11:26 AM I shouldn't laugh, I'll need some long tubes like those for the heavy CRT modifications. 03-Dec-18 11:26 AM https://es.aliexpress.com/store/product/99-5-Al2O3-High-Thermal-Corundum-Tube-OD3-5-ID2-5mm-Round-Single-Bore-Alumina-Tube/1950213_32780933684.html?spm=a219c.search0104.3.44.6eca7f30dC3viJ&ws_ab_test=searchweb0_0,searchweb201602_1_10065_10068_10547_319_10891_317_10548_10696_453_10084_454_10083_10618_10307_10820_10301_10821_10303_537_536_5727511_10059_10884_10887_100031_321_322_10103_5727011-10891,searchweb201603_51,ppcSwitch_0&algo_expid=fa3e22c8-2cec-4d2a-a036-0c7d9d300524-7&algo_pvid=fa3e22c8-2cec-4d2a-a036-0c7d9d300524 03-Dec-18 11:26 AM 300mm * 3.5mm OD 2.5mm ID, total with shipping for 5uds: 41€ 03-Dec-18 11:29 AM The other reason i used ortech was we needed guaranteed kv insulation and thermal properties. Cant really trust ali for that... 03-Dec-18 11:31 AM Actually ortech may be the place I was looking at, at least one of them 03-Dec-18 11:32 AM Hmm... 300x3x2mm, 75€ that's getting expensive 03-Dec-18 11:32 AM The other big one online is cortech and they are more expensive/hard to order from 03-Dec-18 11:59 AM oof, ouch 03-Dec-18 11:59 AM wallet-hurting juiceceramics 03-Dec-18 11:59 AM I will need some more exotic assemblages of ceramic for the other high-ish voltage/high current feedthroughs in my chamber at some point and I'd planned to order those simultaneously, so given those prices i might be able to scrounge up a minimum order... maybe 03-Dec-18 11:59 AM there is also the possibility of, maybe, a ceramics group-buy rotation :D 03-Dec-18 11:59 AM just hand em a weird af cumulative BOM and then redistribute the goodies accordingly 03-Dec-18 11:59 AM depends on how they calculate minimum order prices though i guess 03-Dec-18 11:59 AM maybe it's time to get into hobbyist vacuum pottery... :S 03-Dec-18 12:12 PM What voltage and current? You don't really need really crazy assemblies until you start getting to very high voltage/current levels. 03-Dec-18 12:12 PM Depending on your working vacuum level, there are ways of manipulating fields to minimize breakdown. Big MV pulsed systems use field grading structures made from stuff like acrylic at high vacuum. 03-Dec-18 12:12 PM When I get to the EXEDA II experiment, I will be sharing design for low cost specialized feedthroughs at ridiculous voltages and currents for high vacuum. EXEDA I will just use a special ceramic insulator I got since it's free and easiest to get running for the first system. 03-Dec-18 12:12 PM But again it goes back to your expected operating pressure, voltage, and current. 03-Dec-18 12:21 PM https://twitter.com/nanographs/status/1069384450780221440?s=19 03-Dec-18 12:25 PM There is an issue with bonding ceramics to metal. Glass feedthroughs can just have the metal pushed through the molten glass, but ceramic bonding requires a multi step bonding process. Usually a special metal that wets the ceramic, followed by other brazing processes, accounting for different thermal expansions, etc. It may work ok st low vacuum, but at high vacuum I would suspect issues 03-Dec-18 12:28 PM So for my one 6" CF feedthrough, it has what I believe are fairly standard electrical feedthroughs, which I believe are 7kv-rated insulation around (I think) 1/4" copper rods. Current capacity is probably up in the low hundreds of amps, if I had to guess. Mostly meant for higher-current usage than high voltage, and I have actually inadvertently (albeit predictably) ended up with breakdown arcs along the external body of said insulators while attempting higher voltage runs 03-Dec-18 12:28 PM What I need are some insulating rods for the inside of the vacuum chamber; on the HV side they are just these long columns of bare copper that I'd like to insulate from arcing to, specifically, the inner bit of the flange that they're settled into (they were not welded in flush and i am not sure if that is an expected design) 03-Dec-18 12:28 PM The flange itself says MDC but I have yet to poke through their catalog to see if its a standard feedthrough type they offer. Three power feedthroughs and one (insulated!) 1/4" VCR gas feedthrough. It really is begging to have an ion gun built around it. :9 03-Dec-18 12:28 PM But, yeah, at higher pressures there's been arcover problems internally, and obviously the entire column becomes a massive glow discharge point, which I'd like to avoid. At one point, uh, in some of my pictures, when I had a fusor-ish grid on there... I was using slurpee straws as insulation >.> 03-Dec-18 12:28 PM So I have some slightly melted and steel-sputtered Slurpee straw bits kickin' around somewhere as room decoration :D 03-Dec-18 12:34 PM @qualia I'm into it, I also want to make ceramic chip carriers. 03-Dec-18 12:38 PM You know what I'd like to research at some point is gases that have interesting charge recombination properties for chamber backfilling during particle optics experiments. Like, ways to 'see' electron beams being bent, focused/defocused, maybe localized non-neutral charge distributions.. 03-Dec-18 12:38 PM The backfill gas used in plasma globes immediately comes to mind, which, iirc, is not some monatomic species but some interesting mixture designed to give pretty tracers 03-Dec-18 12:38 PM The entire domain of 'what are ways I can get visual feedback from this thing' is interesting to me, from eyeballin' it and looking for pretty patterns/oscillations/striations to dc-to-gamma spectroscopy 03-Dec-18 12:41 PM This depends on the type of gun you are running 03-Dec-18 12:41 PM Also the distance of beam travel, voltage, current, etc 03-Dec-18 12:52 PM I do have an experiment planned for beam visualization like you are describing, but it would rely on using a very high kev beam... 03-Dec-18 12:53 PM I really like pressing my face up against viewports so I am aiming for rather lower energies :D 03-Dec-18 12:53 PM Oh yeah you don't want your face near this. Going to have to rely on remote Web cam or something 03-Dec-18 12:55 PM So the Princeton Plasma Physics Lab has this all-online Plasma Physics 101 thing with an actual control-it-yourself demo device. It's called the Remote Glow Discharge Experiment https://scied-web.pppl.gov/rgdx/ 03-Dec-18 12:55 PM And, like, I really /really/ like visual demos/teaching aids/etc where you get to turn knobs and watch stuff change. The Exploratorium in SF has a glow discharge tube very much like this too. 03-Dec-18 12:55 PM I'm kind of wondering if it would be possible to build a giant quadrupole mass filter/FODO lattice, where you can actually see the changing shapes of various beams as you tweak parameters 03-Dec-18 12:55 PM Or, like, a giant one of those in a big glass tube 03-Dec-18 12:58 PM If you had a clear glass tube, and inserted a phosphor coated plate along the length, and had the beam skimming past the surface to illuminate the line as it travels down the tube, couldn't you visualize these changes? 03-Dec-18 12:58 PM _apliedion started his machine the world went down in flames 03-Dec-18 12:59 PM is also getting totally distracted from work, also. 03-Dec-18 12:59 PM I could! That's the other option. 03-Dec-18 12:59 PM .. also, like, finding an even-grain-size phosphor I can paint onto things for diagnostics is also on the to-do list. 03-Dec-18 12:59 PM Maybe just some ZnS(Ag) powder 03-Dec-18 01:00 PM I think the phosphor screen may be your best bet for cool visualization at low energies 03-Dec-18 01:00 PM It also has practical applications with high energy systems. Same concept as YAG screens, except for yours you are looking to visualize changes along the length of the beam rather than the cross section at a point 03-Dec-18 01:03 PM I'd want to visualize cross sections at the end of the quadrupole, too. Part of my idea involved a combination of mass filtering of ionic species, resulting in what I would think could be a thin beam of excited ions of a single species.. and if that could be done at glow discharge pressures using some kind of cold cathode ion gun, then perhaps that could be coupled into a diffraction grating to get, say, the emission lines of just hydrogen or oxygen or whatever 03-Dec-18 01:03 PM but that's a bit adventurous perhaps 03-Dec-18 01:06 PM For visualizing at the end, you would place the phosphor screen (probably thin glass coated with it) to intersect the beam at the end. You could have both lengthwise and cross section on the same tube. 03-Dec-18 01:06 PM You could probably build the whole filtering and visualization with a cf cross, using compression fitting for glass visualization tubes, as well as other instrumentation 03-Dec-18 05:23 PM I dream of twitch-plays-electron-microscope with weekly or monthly sample slides 03-Dec-18 05:23 PM Hmmm 03-Dec-18 05:26 PM Or just some sort of random walk 03-Dec-18 05:26 PM Maybe try training a neural net off a gallery of curated photos and have it hunt for whatever it thinks are cool looking pictures 03-Dec-18 05:26 PM I think I remember hearing about a satellite imaging company that did that. 03-Dec-18 05:33 PM @qualia did you check advancer53 on eBay out? Re technical ceramics. He has a bunch of tubing. EBay makes looking for a particular seller horribly difficult. Here's a link. https://m.ebay.com/sch/advancer53/m.html?_ipg=50&_sop=12&_rdc=1 03-Dec-18 05:37 PM oh, goodness, i'm gonna hafta cross-check what I need with what he's got 03-Dec-18 05:37 PM although right off the bat i see some cylinders that look like they might be perfect for one of my feedthroughs.. 03-Dec-18 05:37 PM alsoalso i'll have to throw a couple dozen diamond cutoff wheels in the cart, too, and maybe buy some extras for practice 03-Dec-18 07:12 PM Well this is a pretty decap 03-Dec-18 07:12 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181203_191128-CC7F9.jpg 03-Dec-18 07:12 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181203_190915-EA319.jpg 03-Dec-18 07:13 PM very nice! 03-Dec-18 07:13 PM @AdamMcCombs if you just want chips to look at I have tons of bare dies that I may or may not have found in the trash at work... 03-Dec-18 07:13 PM Some that are old enough that a 50x magnification microscope is litterally enough to see all the features lol 03-Dec-18 07:13 PM looking down through the metal layers is really freaking cool 03-Dec-18 07:15 PM Yeah I would be interested... 03-Dec-18 09:00 PM Me too, altugh I don't have a good microscope yet. 04-Dec-18 12:11 AM hi 04-Dec-18 01:14 AM Morning! 04-Dec-18 01:15 AM Also morning! I have to wake up in 5 hours for my flight to Chicago and a smoke detector failed internally, triggering itself. 04-Dec-18 01:43 AM Oh 04-Dec-18 01:43 AM good luck or something. 04-Dec-18 02:20 AM About as much fun as insects deciding a smoke detector would make a good home... 04-Dec-18 02:20 AM And, def GL 04-Dec-18 03:23 AM Okay people, fasten your seatbelts. Here is the plan: Remove the front of a vidicon tube sensor, and use it as a pure electron gun, attached to an endplate for the vacuum chamber. Take an X-Y electrostatic stage and put it in front, making feedthroughs with JB-Weld. Cross all the fingers until bones break. 04-Dec-18 03:23 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-C18BC.png 04-Dec-18 03:32 AM Detail on the holding ledge for the glass and feeedthroughs. 04-Dec-18 03:32 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-8FC82.png 04-Dec-18 09:58 AM good luck, that sounds fun! 04-Dec-18 12:58 PM 04-Dec-18 01:27 PM Heh. that's a fun idea to use gassy tööbs as feedtroughs 04-Dec-18 01:38 PM Tööbs? 04-Dec-18 03:00 PM sounds like something from ikea 04-Dec-18 03:07 PM Totally. damn snoring gf 04-Dec-18 04:43 PM @Leona any answers from the knobs manufacturer? another sleepless night, trying to normalize sleep cycle 04-Dec-18 04:43 PM Nah. Didn't muster the energy to write them yet 04-Dec-18 04:45 PM XDDDD 05-Dec-18 12:20 AM hi 05-Dec-18 12:59 AM hi 05-Dec-18 01:25 AM Hi 05-Dec-18 01:26 AM Good morning everyone! 05-Dec-18 01:26 AM Whoa! A three word greeting? 05-Dec-18 01:27 AM half of my cup of coffee is already gone, I'm beginning to form sentences 05-Dec-18 01:27 AM Fair! 05-Dec-18 01:33 AM BOOOOOOOOOO... dissipates coffee effect 05-Dec-18 01:35 AM NNOOOOooooo snores 05-Dec-18 01:37 AM ...OOOOOD BORNING! 05-Dec-18 01:37 AM XD 05-Dec-18 02:09 AM finally, my second speaker stand is printing! 05-Dec-18 03:53 AM Yay! 05-Dec-18 06:09 AM Joined the server. 05-Dec-18 06:10 AM Welcome! 05-Dec-18 07:31 AM hello 05-Dec-18 08:12 AM Hello, sync 05-Dec-18 10:43 AM Plate stock is finally off to a machine shop, and the adapter plates will be in production in January (shop was super busy, earliest I could get them.) Vacuum simulations for the small 2.75" conflat chamber are complete, and I will be finishing vacuum simulations for the 6" conflat propulsion chamber next week. Once this is done, the design work for the accelerator can finally begin (saving the best for last!). If everything goes to plan, I should have vacuum hopefully end of January. 05-Dec-18 11:31 AM Yay!!! 06-Dec-18 12:27 PM Question 06-Dec-18 12:27 PM Interference and diffraction patterns cause peak intensity proportional to square of number of slots 06-Dec-18 12:27 PM So for large N you get very narrow very high intensity central peak 06-Dec-18 12:27 PM Does anything use this to produce some sort of high power cutting/burning, like a laser cutter? 06-Dec-18 02:42 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181206_133329-AD9BD.jpg 06-Dec-18 04:49 PM @to isn't that the same mechanism by how beamstretchers/compressors work in chirped lasers? 06-Dec-18 05:50 PM @qualia yeah, chirped compressors can use gratings. Prisms and dielectric mirrors are also used for compression as well 06-Dec-18 07:57 PM The last vacuum simulation for the micro propulsion chamber is now complete. Just have to do the project write-up page and organize the results. Looks like I should easily hit my target pressure with plenty of speed for thruster testing (assuming no leaks and negligible backstreaming). That wraps up all the vacuum engineering for everything except EXEDA, which will be very similar in performance for pumping to the propulsion chamber anyway since both are made with 6" conflat tees. I won't start those simulations until the design is finalized, but for V1 it will be pretty straightforward. Starting next week I will begin posting results of the vacuum simulations here and on twitter, and release the project pages. Full setup/input parameters, results, analysis, and simulation files will be available. 06-Dec-18 08:05 PM As an additional note, I will be organizing all of my other non-vacuum DIY science builds (electrospinning, non-thermal plasma processing, and thermal plasma torches) into project pages so all of the details and materials are available in one place. I will also be adding additional projects as well as I get around and tinker with them. I'm thinking the next small side project after the thermal plasma torch wrap-up tomorrow will be paper-based micro-fluidics, using the gliding arc systems and wax paper. 06-Dec-18 08:05 PM In the further future, I would like to do a properly engineered non-transferred thermal plasma torch build and experiment with DIY thermal plasma spray. Should be a pretty simple and straightforward system, since I already have the preliminary design work complete from a couple of years ago. 06-Dec-18 08:36 PM Sorry for being a bit absent the past days. I have been busy getting a lot of TEM stuff done on a secure site so limited phone. 2 300kV scopes that I'm writing software for, picking up a SEM, and getting another TEM ready to lift out through a roof. Its a lot of work... 07-Dec-18 04:30 AM We know, don't worry. 07-Dec-18 04:30 AM chat goes haywire afterwards 07-Dec-18 05:16 AM @qualia didn’t know they existed, looks cool I’ll investigate 07-Dec-18 08:06 AM Is anyone interested in attending High Gradient Wakefield Accellerators with me? 11-22nd March 2019 @ Sesmimbra, Portugal. Hosted by CAS 07-Dec-18 08:06 AM https://cas.web.cern.ch/schools/sesimbra-2019 07-Dec-18 08:18 AM @meowter_space any special requirements? 07-Dec-18 08:18 AM in what way? 07-Dec-18 08:20 AM for the participants 07-Dec-18 08:20 AM ok, you need to upload a CV, right? 07-Dec-18 08:20 AM and then they will decide if you're worthy 07-Dec-18 08:20 AM not if you're already part of the CERN club 07-Dec-18 08:20 AM of course 07-Dec-18 08:22 AM Yea basically :) I can ask if you want? I'm not sure how it works I've never attended a CAS thing before 07-Dec-18 08:23 AM yeah, asking would be nice, i guess others would be interested to? 07-Dec-18 08:23 AM .o(and then we take over the conference) 07-Dec-18 08:25 AM YAS 07-Dec-18 08:25 AM I'd love to go to IPAC but I can't afford a flight to Australia 07-Dec-18 08:55 AM @Nixie i mean to build up a pcb with them and a couple of OPA on it 07-Dec-18 09:02 AM 07-Dec-18 09:02 AM The taking over the conference suits my taste. 07-Dec-18 09:02 AM (don't have a curriculum that can fit me in there no matter what) 07-Dec-18 09:24 AM That would be amazing to attend. I can't afford to fly overseas right now though just for a class. Really cool that they cover both plasma wakefield and dielectric beam systems. Maybe one day, if they ever hold something closer to home. Right now I'd rather invest that money in my accelerator, but I've always wanted to attend these types of lectures/conferences. Also not sure what the selection criteria is like, they probably give much higher preference to CERN members and people involved with CERN than an engineer from a small lab and working in their basement lol. 07-Dec-18 09:28 AM fairs. Idk what you're doing with your accelerator @Applied_Ion but if you need any help hmu ^_^ I've ended up specialising in Beam-Dynamics, mainly longitudinal, but I can cover most BE-RF stuff 07-Dec-18 09:29 AM @meowter_space no RF used on this one, though thanks for the offer! I'm sure I will come across something I will need to reach out to the community for! 07-Dec-18 09:29 AM working with high peak power beams 07-Dec-18 09:29 AM technically it will be 2 types of accelerator, the primary stage can drive the output of a high-energy stage 07-Dec-18 09:29 AM very old and niche technology, the higher energy topology uses a practically forgotten technique that never made it mainstream due to the advances of modern super high energy RF systems, as well as issues with scaling. 07-Dec-18 09:29 AM This build is my own personal system, separate from the work I do at our accelerator facility, which is a conventional RF electron linac. Do you work at an accelerator facility yourself? 07-Dec-18 09:29 AM I think you mentioned something about visiting cern in the past yourself as well 07-Dec-18 09:38 AM In the future, when I have a big workshop I will organize a "conference". But unlike hackaday's this will be highly technical. 07-Dec-18 09:39 AM that would be awesome! Hackaday's Supercon wasn't highly technical? 07-Dec-18 09:45 AM Not at all. The workshops where, but the talks where a flop. They only gave 10minutes to @AdamMcCombs for his SEM talk, for example. Or another 10 minutes for the vacuum tubes guy. 07-Dec-18 09:45 AM And then the shebon was like 45"... 07-Dec-18 09:48 AM oh wow, only 10 minutes? can't fit much detail in that time. What do you mean by shebon? 07-Dec-18 09:49 AM It was sarah petkus project to sense personal arousement. Not that she doesn't deserve the time, but the other talks deserved at least the same. 07-Dec-18 09:49 AM I'd say in two years time I'll try to organize thatm. 07-Dec-18 09:52 AM I was thinking that if I got results for my accelerator in time, and could get funds to travel, maybe to try to give a talk next year but idk. Do you think it's worth attending, having been there yourself? 07-Dec-18 09:55 AM Hm...for you it would be definitely cheaper to go, wich is a bonus (my trip costed like 1500€) As for the worth. Only for the people, if people you know attend, OR you are capable to random talk with strangers (wich I can't) 07-Dec-18 09:55 AM The workshops costed money too, so I didn't attend any. Maybe its more fun if you do. 07-Dec-18 09:57 AM I can't start conversations with random people, I have always been more reserved. I do better with written chats like this, but still usually only on technical stuff 07-Dec-18 09:57 AM I think for presenters they do offer some travel help/reimbursement if you are accepted, not sure Id have to check 07-Dec-18 09:58 AM Not sure. I got invited as a poster presenter, got the goodies for free, but thst's all. 07-Dec-18 09:59 AM If anything it would give good visibility to the project if it works, and maybe help bring more interest in more research-level maker-based particle beams, but socially, I would only know a couple of people 07-Dec-18 09:59 AM The Sunday Talks help a lot with that, from a shy person to another shy person. 07-Dec-18 09:59 AM I only knew adam and he didn't atend until very late the first day, so i was pretty much lost 07-Dec-18 10:00 AM I feel like that's how my day would go there lol 07-Dec-18 10:00 AM huh I have not heard about the hackaday con, seems like a bad deal looking at the lineup 07-Dec-18 10:02 AM I may just do it for the sake of visibility. I don't think academia would give any interest or opportunity in presenting on it, and it's for the maker community anyway 07-Dec-18 10:02 AM @Applied_Ion cool! I don't work at an accelerator facility. I wish! I worked at cern over summer 2017 07-Dec-18 10:03 AM @meowter_space that must have been an amazing experience! I'd love to see the stuff at CERN one day! 07-Dec-18 10:04 AM If you ever pop over hmu! I'll come say hi :) 07-Dec-18 10:04 AM do you live near cern? 07-Dec-18 10:04 AM Nah I live in England but it's only a 2h flight for £50 return 07-Dec-18 10:04 AM oh wow, nice! 07-Dec-18 10:05 AM I go quite regually that way 07-Dec-18 10:05 AM Another uk person 07-Dec-18 10:05 AM Not sure how Brexit will mess with that 07-Dec-18 10:05 AM HELLO 07-Dec-18 10:05 AM although, I live on a small island off the south coast, so I don't know if I still count as UK... 07-Dec-18 10:08 AM XD 07-Dec-18 10:08 AM The superco definitely will give you visibility, that for sure. 07-Dec-18 10:09 AM @Zhang which small island? 07-Dec-18 10:09 AM Isle of Wight 07-Dec-18 10:09 AM But something must be organized in EU 07-Dec-18 10:09 AM Oooo 07-Dec-18 10:14 AM I know there was something named EHSM http://ehsm.eu/ But I think they don't do it anymore. 07-Dec-18 10:32 AM Benson Mute wanted to invite me because of my X-Ray youtube channel, but I declined, as it was me playing at work with no real knowledge. (And now hat I'm doing something interesting, They don't) 07-Dec-18 01:06 PM @Nixie didnt know you did xray stuff, what type of things were you working on with it? 07-Dec-18 01:13 PM Nothing really. They bought an xray machin to inspect led welding bubbles fornhigh power aplications, and I sort of got permission to xray whstever I wanted on my free time. https://www.youtube.com/channel/UCioDtoW5sryOfpgLpa_gtiw 07-Dec-18 01:16 PM Nice! Really cool stuff, I will have to take a look at it more 07-Dec-18 01:16 PM can't wait to start getting into xray stuff too. Will have to operate at severely reduced levels for safety, but its always exciting to see what can be done with it 07-Dec-18 01:16 PM I just read the program schedule for the CAS thing, man I want to see that stuff now. It turns out though that the CAS lectures from previous years are all available for download on the website. So much reading to do now, tons more resources to add to the library! Hopefully they will post this year's program afterwards as well 07-Dec-18 01:28 PM 07-Dec-18 01:32 PM definitely going to sit down now and download/review every available presentation and lecture. just way too much fun stuff in here 07-Dec-18 01:46 PM scanning through the various topics over the years, doesn't seem like there is anything specific to the accelerator tech i'm exploring now, but still an incredible collection of resources. glad they make it available. 07-Dec-18 05:11 PM ah, a nordson unit 07-Dec-18 05:11 PM I know the guy that developed the source in them 07-Dec-18 09:29 PM Finally, vacuum simulations and project write-ups are all done. So tedious, glad that's over! Won't have to do any more vacuum simulations for a while until my propulsion engine and accelerator designs are done. All the tedious stuff is out of the way, I can finally start the real and fun design work. 07-Dec-18 11:20 PM 07-Dec-18 11:28 PM o/ 07-Dec-18 11:28 PM evening everyone, happy weekend 07-Dec-18 11:53 PM moin! 08-Dec-18 12:55 AM Ohaio! 08-Dec-18 02:34 AM Oh, aluminium peg spot welding requires more amps to weld than my puny single transformer spot welder can give. /looks unsurprised/ Will have to TIG the thing to the other thing Dang! 08-Dec-18 03:51 AM get/build a capacitor discharge welder? 08-Dec-18 04:27 AM I don't have equipment or skills for any welding, but I have been brazing using a large propane torch with a swirl tip. Works great for copper to copper using phos-copper (no flux needed). For stainless to stainless or copper in vacuum I have been using sterling silver with the black paste flux. Sterling is close to the eutectic used in one vacuum braze alloy, but is far cheaper. It has more sliver, so will erode copper parts somewhat, especially if you overheat the copper. Aluminum braze alloys are high zinc, so not attractive for high vacuum with high temp operating conditions. 08-Dec-18 04:27 AM Most braze alloys have at least some zinc. Note that a "vacuum brazing alloy" is for brazing in vacuum, rather than necessarily vacuum use assemblies. But the issues with metal volatility are the same. At 1e-6 even soft solder seems to be ok for parts that don't get hot. 08-Dec-18 05:49 AM I want to make the holder posts for the targets in the sputtering chamber, so they'll get hot. Since I don't have the parts for a capacitor welder, it's just easier to tig it. 08-Dec-18 05:49 AM (I hate welding aluminium though) 08-Dec-18 10:04 AM This is so silent... 08-Dec-18 10:06 AM AAAAAAaaaahhhhh 08-Dec-18 10:08 AM XDDDDDDDDDD 08-Dec-18 10:18 AM @Nixie what is your holder design? Can you make it with non weld connections? 08-Dec-18 10:19 AM I have nothing in mind in particular. The idea was to attach some nipples to the aluminium refrigeration plate and use some steel springs to hold down the target. 08-Dec-18 10:19 AM (using said nipples as retention pins) 08-Dec-18 10:32 AM Got any cad for it? I did a sputter gun design a while ago, didn't get around to finalizing it though. Still preliminary concept like the thermal torch 08-Dec-18 10:32 AM It follows a more conventional gun design 08-Dec-18 10:35 AM My sputter gun / endcap for the vacuum chamber / refrigeration circuit are a single piece. XDDDDD Can't drill it, or change much of it without compromising the integrity of the endplate. 08-Dec-18 10:35 AM let me dig a file 08-Dec-18 10:35 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/img-20180312-wa0007-624FA.png 08-Dec-18 10:35 AM it's that piece, flat bottom. and 4mm thin at the sputtering zone. 08-Dec-18 10:35 AM Don't worry, I have to weld the pegs no matter what, I'm just complaining that the asy solution did not work. XDDD 08-Dec-18 10:35 AM (and I hate TIG aluminium welding) 08-Dec-18 10:35 AM (and also, I'm half bored. Sick Gf went to sleep (that part of the month sick) and I have been left to my own devices, but can't make noise at home. 08-Dec-18 10:54 AM Makes sense. Do you have your own tig welder? 08-Dec-18 10:58 AM offended face 08-Dec-18 10:58 AM XDDDD 08-Dec-18 10:58 AM you'd do better asking what (metal machinery) I don't have. 08-Dec-18 10:58 AM jumps to #off-topic-thats-sometimes-on-topic to show photos of the workshop 08-Dec-18 11:01 AM Oh nice, I'd like to learn to weld, it would be a major help. I'd like to have any tools for machining besides a lousy hand drill 08-Dec-18 11:01 AM If I could machine more stuff myself or had the tools to do it, I'd have an explosion of high tech toys I could just pump out. Lots of design work fir super low cost systems, but little physical products. 08-Dec-18 11:04 AM Plasma cutters are super cheap. mine costed 200€ shipped. they are a good start for sheet metal working. 08-Dec-18 11:04 AM the welder was a bit more expensive, 750€, but there are cheaper, mine just happens to be acceptable to do everything. ferrous, non ferrous and such. (AC/DC, electrode, TIG, etc etc... 08-Dec-18 11:04 AM Lathes and mills...well, that's another story. 08-Dec-18 11:05 AM Yeah, I know some stuff isn't expensive, but I don't have the money or space for what I need. Mainly simple machining. Lathe and small cnc would be perfect. Even a drill press lol 08-Dec-18 11:05 AM Though I'd prefer a non transferred torch to a plasma cutter any day, way more fun 08-Dec-18 11:06 AM Damn you have a tight space then. 08-Dec-18 11:06 AM Tight budget 08-Dec-18 11:06 AM Non transferred torch? 08-Dec-18 11:06 AM work more-die-raise from dead-buy tools. 08-Dec-18 11:06 AM XDDD 08-Dec-18 11:06 AM Yeah, the stuff I have posted on twitter the past few days lol 08-Dec-18 11:06 AM For things like thermal plasma spray 08-Dec-18 11:08 AM Ahh, I thought that was not useful for cutting, only spraying and metal treating. 08-Dec-18 11:08 AM Nozzles are much simpler, though. 08-Dec-18 11:08 AM (wich reminds me I would like to make a small version to adapt to the laser cutter and have a small metalcutting CNC machine. 08-Dec-18 11:13 AM You can cut, but not as effective. Way more power potential though. Both are pretty simple to make, I made a working demo with trash. For that though I'm more interested in just experimenting with controlling the raw arc power rather than practical stuff, but thermal spray would be pretty sweet. 08-Dec-18 11:13 AM The trouble is replacements. (I'm a lazy bastard, sorry for that) 08-Dec-18 11:13 AM XDD 08-Dec-18 11:13 AM I am more into practical stuff, I guess. (I mean, I would buy the plasma, then maybe build yours, then sell the other one, for example. 08-Dec-18 11:25 AM I like to primarily focus with practical, but some things are fun to just run for the sake of seeing how much power you can shovel into it. The beam system I'm building will have tons of practical applications, but I'm still gonna have fun trying to squeeze every ounce of beam power out, and really drive it to its knees. Same with the torch. Useful for thermal spray, but running it to the max power it can handle and trying to push it further is exciting. 08-Dec-18 11:29 AM XDDD 08-Dec-18 11:29 AM I can totally respect that. 08-Dec-18 11:32 AM I may have an unhealthy obsession with high power stuff lol. Probably why I am so enamored with pulsed power and it's related applications 08-Dec-18 11:33 AM unhealthy obsession does not exist within the boundaries of this group. 08-Dec-18 11:33 AM XDDDDD 08-Dec-18 11:38 AM That's how you know people here will push new limits and make more awesome stuff! 08-Dec-18 11:40 AM Absolutely yes. 08-Dec-18 11:40 AM group highfive 08-Dec-18 11:44 AM \o 08-Dec-18 11:44 AM o/ 08-Dec-18 11:44 AM heh, well done! 08-Dec-18 11:44 AM yay 08-Dec-18 11:44 AM let's just design our own diff pump 08-Dec-18 11:48 AM I would love to do that, but I know nothing about how to do it. Just a general flavor of what is going on. 08-Dec-18 11:49 AM we could keep the innerts and just replace the wall thingy 08-Dec-18 11:49 AM In my mind designing a water jacketed diff pump should not be that difficult. And in fact, the jacket itself could be made out of plastic, for example, if the heat was isolated properly. 08-Dec-18 11:51 AM wouldn't it be easier to weld a second wall to it and flood the resulting space? 08-Dec-18 11:51 AM I wonder if we could even make the bottom part like a KF-joint, so it's easily dissasemblable. 08-Dec-18 11:51 AM No because the L shaped port on one side, wich makes difficult to also jacket that. 08-Dec-18 11:51 AM also, if the jacket comes in two parts, you can dismantle, clean and reassemble it super quickly. 08-Dec-18 11:51 AM if welded, you risk corrosion going unnoticed. 08-Dec-18 11:51 AM (even if using stainless) 08-Dec-18 11:52 AM but the side port for the roughing pump is below the "line of cooling" 08-Dec-18 11:52 AM at least on mine 08-Dec-18 11:52 AM but requires cooling itself too, to reduce losses, afaik 08-Dec-18 11:52 AM (@Applied_Ion we're here!) 08-Dec-18 11:53 AM mine wasen't cooled ^^ 08-Dec-18 11:53 AM ah 08-Dec-18 11:53 AM I might be confused, then. 08-Dec-18 11:53 AM From the old stuff, diff pump design is a bit of a lost art 08-Dec-18 11:53 AM (highly probable) 08-Dec-18 11:53 AM But they are so useful, how come is lost? 08-Dec-18 11:53 AM but my pump is tiny, most bigger ones have a cooled one 08-Dec-18 11:54 AM In theory they are very simple. Bit building an optimized one is tough 08-Dec-18 11:54 AM I have looked into building one myself 08-Dec-18 11:54 AM Probably won't surprise you I worked on a small design for a kf50 hardware based one 08-Dec-18 11:55 AM Nope, by now we know you have done everything. (intended as a praise) 08-Dec-18 11:56 AM so there is no actual limitation to using KF seals at the bottom of the pump, then? 08-Dec-18 11:56 AM the bottom's getting pretty hot 08-Dec-18 11:56 AM like 200+ °C hot 08-Dec-18 11:56 AM I even considered manufacturing and selling them 08-Dec-18 11:56 AM No not for the bottom 08-Dec-18 11:56 AM (my evaporator for the oven was intended to be used as a base for a diff, but then I screwed up the pieces) 08-Dec-18 11:56 AM That would be welded 08-Dec-18 11:57 AM why welded? 08-Dec-18 11:57 AM and why not KF joint and a good thermal isolation? 08-Dec-18 11:57 AM (like, a deeper pump, and have the heat up into the pump) 08-Dec-18 11:57 AM (with a custom flange that acts as cartridge holder) 08-Dec-18 11:58 AM you don't need access to the bottom part, the jets can be taken out of the top and the heater can be screwed off from the outside 08-Dec-18 11:58 AM True. 08-Dec-18 11:58 AM it's just that welding that part would be...troublesome 08-Dec-18 11:58 AM here comes the expert. 08-Dec-18 11:59 AM I think the reason why they have the tube around it is that it is easier to make the barrel 08-Dec-18 11:59 AM I think welding the coil around is a nightmare. 08-Dec-18 11:59 AM no 08-Dec-18 11:59 AM not at all 08-Dec-18 11:59 AM it is brazed 08-Dec-18 11:59 AM (but not 100% sure) 08-Dec-18 11:59 AM oh, ok. 08-Dec-18 12:00 PM also helps with heat transfer 08-Dec-18 12:00 PM The bottom gets real hot. Yeah, the coil is brazed 08-Dec-18 12:00 PM the annoying thing with diff pumps is the cycle time 08-Dec-18 12:00 PM and the backstreaming 08-Dec-18 12:00 PM Backstreaming is a small price to pay for speed 08-Dec-18 12:00 PM valve on the high vacuum side and baffles 08-Dec-18 12:01 PM that helps only so much 08-Dec-18 12:01 PM well, a 1000l TMP is significantly smaller than a 1000l diff pump 08-Dec-18 12:01 PM Baffles cooled to 15C with dc 705 reduces it to negligeable amounts 08-Dec-18 12:01 PM and you can vent it to atm without doing damage at full speed 08-Dec-18 12:01 PM XDDD 08-Dec-18 12:01 PM So...how can we design our own diff pump, gentlepeople? 08-Dec-18 12:02 PM I'm not sure about a 1000l/s tmp being smaller 08-Dec-18 12:02 PM I do want that jacketed thing. it's stuck in my head. 08-Dec-18 12:03 PM go ahead an do it, no one's gonna stop you ^^ 08-Dec-18 12:04 PM Design work is a bit of a black art with them. Not much in the literature, only diagrams 08-Dec-18 12:04 PM and once we're done with the diff we should make a GM cryo 08-Dec-18 12:05 PM most of our systems are completely dry now 08-Dec-18 12:05 PM cryo would probably be easier 08-Dec-18 12:06 PM @GigaSquirrel you just want me to do it so you can copy it later. XDDDD 08-Dec-18 12:06 PM GM? 08-Dec-18 12:08 PM Tge original diff pumps were blown glass. Both mercury as well as oil 08-Dec-18 12:08 PM Cryo is easier physically, but u need liquid helium abilities 08-Dec-18 12:08 PM I have to reserve my glassworking for the cheap e-beam. 08-Dec-18 12:09 PM I was more thinking on the likes of air liquefier, not cryopumping, as a start 08-Dec-18 12:09 PM that is a completely different process 08-Dec-18 12:09 PM ? 08-Dec-18 12:09 PM but actually the only annoying thing is to source the last stage gas and a nitrogen membrane 08-Dec-18 12:09 PM or you go the high pressure linde way and need to find a high pressure compressor 08-Dec-18 12:10 PM depends on what tech you use, afaik linde is used for high scale stuff, and gm for small scale 08-Dec-18 12:10 PM well, yeah 08-Dec-18 12:10 PM but having to deal with stripping CO2 is annoying 08-Dec-18 12:10 PM so realistically you need a membrane anyway for a hobby system 08-Dec-18 12:10 PM but if you have a dewar it is not expensive to buy LN2 ime 08-Dec-18 12:12 PM I haven't found any store willing to sell <100 liters of LN2 08-Dec-18 12:12 PM yes 08-Dec-18 12:12 PM that is because 100l is nothing 08-Dec-18 12:13 PM 100 l is my dewar filled 5 times 08-Dec-18 12:13 PM and I'm not gonna spend a whole lot of money on a 100l dewar 08-Dec-18 12:13 PM XDDDDDDD 08-Dec-18 12:14 PM that's why I bought a broken cryopump, trying to build my own liquiefier 08-Dec-18 12:14 PM 200l is a good size, but you cannot really get away with just that much 08-Dec-18 12:14 PM I was suprised when I first started working with LN2 how much you actually need to do something useful 08-Dec-18 12:14 PM besides LN2 cookies and superconductor racetracks 08-Dec-18 12:15 PM yep 08-Dec-18 12:15 PM ^^U 08-Dec-18 12:15 PM took half of my dewar to fill the 2l dewar of my HPGe 08-Dec-18 12:15 PM but I guess it would be more efficient to use the proper filling lines... 08-Dec-18 12:16 PM protip, now that it is christmas time, dip some cookies in LN2 and eat them 08-Dec-18 12:16 PM makes for a good smokeshow 08-Dec-18 12:17 PM ehhh 08-Dec-18 12:17 PM my dewar comes from the scrapyard and the holders made it obvious it was used for sperm samples 08-Dec-18 12:17 PM just don't use ones that have a large thermal mass, eg chocolate/jam ones 08-Dec-18 12:18 PM https://www.ebay.com/itm/Martin-Marietta-CryoCooler-Cryogenic-Stirling-Liquid-Nitro-IR-Detector-21025493/222641040495?hash=item33d670ac6f:g:Ht8AAOSwuj5bcBJ3:rk:8:pf:0 08-Dec-18 12:18 PM I'm not going to use any of the LN2 for anything food related 08-Dec-18 12:18 PM @Nixie looks like a compressor for some stirling type? 08-Dec-18 12:18 PM or maybe pulsetube 08-Dec-18 12:19 PM could be worse, but it is good fun 08-Dec-18 12:19 PM I think they are pulsetube ones 08-Dec-18 12:19 PM with a coil and plunger 08-Dec-18 12:19 PM very low power tho 08-Dec-18 12:19 PM but still very cool 08-Dec-18 12:20 PM very cool XDDDDD 08-Dec-18 12:22 PM one of my lowkey projects is finishing my 2/3 stage cascade cooling system to actually make LN2 08-Dec-18 12:22 PM why so many stages? Isn't one enough? 08-Dec-18 12:22 PM Ohh. 08-Dec-18 12:22 PM anything we can see? 08-Dec-18 12:24 PM one is quite difficult to make 08-Dec-18 12:24 PM because you need a few gasses in there to make it work 08-Dec-18 12:24 PM and you have to separate the fractions 08-Dec-18 12:24 PM and you cannot make it with just one gas, look at the phase diagrams of common refrigerants 08-Dec-18 12:26 PM if I undertand correctly, using the last gas directly just would be impossibly inneficient? 08-Dec-18 12:28 PM most of the time you are not even able to liquify it 08-Dec-18 12:28 PM and then it is impossibly inefficient because it does not work 08-Dec-18 12:29 PM (I know nothing about cooling, sorry) 08-Dec-18 12:31 PM well, but you do know how phase change cooling (or heating for that matter) works in general? 08-Dec-18 12:36 PM Sort of, yes. 08-Dec-18 12:36 PM (ohh, small intro on cooling! shakes with excitement) 08-Dec-18 12:37 PM just expand some gas and it will get cooler, as easy as that 08-Dec-18 12:39 PM shush shush...i wanna hear 08-Dec-18 12:46 PM yeah kinda 08-Dec-18 12:46 PM the idea is, you take a gas and do work to it thus increasing its pressure 08-Dec-18 12:46 PM then you cool said high pressure gas and it will liquify 08-Dec-18 12:46 PM and then you shove the liquid through a metering device (read orifice) where it will come out and try to get gaseous again 08-Dec-18 12:46 PM but doing so requires energy again, which is the heat it removes from the surrounding 08-Dec-18 12:46 PM and then it is getting sucked into the compressor again and the cycle starts again 08-Dec-18 12:48 PM yep 08-Dec-18 12:48 PM so, what goes into cryo? 08-Dec-18 12:52 PM afaik cryo dosen't use phase change cooling 08-Dec-18 12:52 PM basically the same cycle but without phase a change 08-Dec-18 12:52 PM mostly just compressing / decompressing He because that will stay as a gas for sure 08-Dec-18 01:01 PM yeah it is a stirling expander 08-Dec-18 01:04 PM In terms of a diy system, I still think diff is much cheaper and easier to manufacture all things considered. Just simple machining and brazing with common parts. Cryo needs more specialty equipment. For pumping speed optimization however, cryo is much easier and straightforward to calculate. Diff requires more experimental work. 08-Dec-18 01:06 PM signed 08-Dec-18 01:07 PM depending on what you do an ion pump can be enough 08-Dec-18 01:07 PM one of our systems was like that 08-Dec-18 01:07 PM sorption pump for rough vacuum and then straight to ion/Ti sublimators 08-Dec-18 01:08 PM Oh yeah, ion pumps fir uhv clean is the way to go. Our accelerator uses big ion pumps down the beam line 08-Dec-18 01:08 PM They can't handle high gas loads, but for low gas systems thst need clean uhv they are the way to go 08-Dec-18 01:08 PM yeah, we supplemented the system with a cryo to get faster cycle times 08-Dec-18 01:08 PM but the annoying thing is the finite lifetime of the adsorber 08-Dec-18 01:08 PM before you have to turn it off an regen it 08-Dec-18 01:10 PM In principle ion pumps would be quite easy to build mechanically 08-Dec-18 01:10 PM There is more info on design equations for them than diffs 08-Dec-18 01:10 PM Ion pumps are pretty easy to run too 08-Dec-18 01:11 PM yes, I thought about it as well, but if you want them to be nice you need alnico magnets so you can use them during bakeout 08-Dec-18 01:11 PM Really set and forget 08-Dec-18 01:11 PM You can use removable magnets though 08-Dec-18 01:12 PM the rest is pretty simple, just a high surface area trap plate and that's it 08-Dec-18 01:12 PM sure 08-Dec-18 01:12 PM A lot of big ones can get them removed for baking 08-Dec-18 01:12 PM but eh, that's work 08-Dec-18 01:12 PM Though the nice ones are all in one 08-Dec-18 01:12 PM all I've seen can be baked 08-Dec-18 01:12 PM you really only gotta select the correct magnet 08-Dec-18 01:13 PM They are stupid heavy. My god, a 200 l/s ion pump is absurdly heavy 08-Dec-18 01:13 PM I got 2 super old ones used from decades ago. Not sure if they work, but I may rebuild the anode myself. They got removable magnets. 70 l/s. I'll post pictures some time. 08-Dec-18 01:13 PM Thing is none of my systems need super high vacuum lol 08-Dec-18 01:16 PM I have two pretty tiny varian ones 08-Dec-18 01:16 PM they are heavy indeed 08-Dec-18 01:18 PM I'd rather have smaller ones due to the weight 08-Dec-18 01:18 PM Don't really need ion pumping for my stuff though 08-Dec-18 01:18 PM If I needed to bake and pump to condition a system for a very long time, ion would be my bet. Takes almost no power to run. 08-Dec-18 01:22 PM yup, but you have to watch the current 08-Dec-18 01:22 PM Oh definitely, they can run away real fast 08-Dec-18 01:22 PM It's happened to me pushing our test injector a bit too hard 08-Dec-18 01:23 PM yeah we always push the limit of the pump rate when running deposition 08-Dec-18 01:23 PM so you have to be really careful outgassing the sources 08-Dec-18 01:23 PM Always a fun balance lol 08-Dec-18 01:23 PM otherwise click and there go two weeks of downtime 08-Dec-18 01:23 PM because when it shuts off you might as well replenish the sources, clean the windows and do all the other stuff 08-Dec-18 01:32 PM that's also the reason why we added the cryo 08-Dec-18 01:36 PM Makes sense, sounds like a real pain to deal with. Our stuff isn't as much of a pain on a normal basis, though we never should open it unless something major is needed, like changing the cathode in the injector once every 5-10 years or so. Or a catastrophic failure, which we try to avoid lol. Very, very rare, so many interlocks it's tough, but it has happened at least once in the 60 years of operation. 08-Dec-18 01:37 PM nah, it is not really that bad, the systems are just mostly old 08-Dec-18 01:38 PM Yeah, our stuff is ancient 08-Dec-18 01:38 PM there is an issue with one of the wafer handlers loosing home and ramming wafers into the chamber wall 08-Dec-18 01:38 PM but eh 08-Dec-18 01:38 PM once in a while you clean out the scrap out of the bottom and it is fine 08-Dec-18 01:38 PM or the PhD students turning off a source too fast and then it explodes 08-Dec-18 01:38 PM or a viewport shatters just because it felt like it 08-Dec-18 01:38 PM most of the issues come from the electronics burning up that support the equipment 08-Dec-18 01:45 PM Wow. For us, catastrophic failure would be devastating. Happened once like a few years after it was built in the 60s. They were told it would never run again, but the original guys literally took the thing apart, scrubbed it down in the parking lot with all nasty chemicals and self built sprayers, put it together, and made it run again. Really incredible. 08-Dec-18 01:45 PM like tmp controllers, valve drivers, ebeam supplies are a constant offender and stuff like that 08-Dec-18 01:45 PM Most of our issues are usually the old modulators that need tending and part replacement 08-Dec-18 01:46 PM why though? I mean if you suddenly vent it the only thing that is going to happen that there is a bit of dust in there 08-Dec-18 01:46 PM I'd suspect if you would just pump it again it would work 08-Dec-18 01:46 PM No its more complex for accelerators 08-Dec-18 01:46 PM Venting is real bad 08-Dec-18 01:46 PM When they are fabricated, they never see air again 08-Dec-18 01:46 PM Shipping and assembly 08-Dec-18 01:46 PM They high power rf in the structures makes it real crucial 08-Dec-18 01:46 PM Like MW peak power 08-Dec-18 01:48 PM sure, but they were vented when they were assembled at some point 08-Dec-18 01:48 PM so if you repair the issue and start pumping again I can't really see how that would change a lot 08-Dec-18 01:48 PM that might be the case again of people being afraid because they always did it like that 08-Dec-18 01:49 PM Held with neutral gas fill, but it cannot be air. Reassembly after shipping us a real tough process 08-Dec-18 01:49 PM Like I said it's not just the pumping 08-Dec-18 01:49 PM It's the high power rf 08-Dec-18 01:49 PM Any contamination that carbonizes in their from the intense fields would ruin operation 08-Dec-18 01:49 PM It must be kept UHV clean at all times 08-Dec-18 01:50 PM yes, but you vent them before assembly so they sit around for a while so that cannot be that bad 08-Dec-18 01:50 PM sure, but just venting them does not make them not uhv clean 08-Dec-18 01:51 PM They don't sit around for a while at all 08-Dec-18 01:51 PM They are held with positive pressure of argon/clean dry nitrogen. Always, until pumping. No air ever. Even during assembly. Often they are shipped under vacuum, but that's more expensive 08-Dec-18 01:53 PM sure, but you still have to vent them prior to assembly 08-Dec-18 01:53 PM even if you flush them constantly it hardly changes anything 08-Dec-18 01:53 PM we spent quite a while trying various stuff to improve our cycle time 08-Dec-18 01:54 PM It never vents to air though 08-Dec-18 01:54 PM like flushing with nitrogen or argon, and it made virtually no difference 08-Dec-18 01:54 PM you always get moisture in there and oxidation, as you cannot provide enough flow to actually keep the air out at the interfaces 08-Dec-18 01:55 PM It's not flushed. It never sees air 08-Dec-18 01:55 PM Oxidation us bad, can't happen 08-Dec-18 01:56 PM how can you take an end cap off without being in air? 08-Dec-18 01:56 PM Gate valve? 08-Dec-18 01:56 PM that has air on the other side 08-Dec-18 01:56 PM and you can see in the video that they did not have gate valves on the sections 08-Dec-18 01:56 PM just pinched off flanges 08-Dec-18 01:56 PM as I said, most likely it is people being overly cautious, which is fine, but I don't jump on that bandwaggon 08-Dec-18 01:58 PM That's fine. Neither do i, I'm just telling you the standard procedure in this field lol. It may not be able 100% nevessary, but accelerator systems usually do this 08-Dec-18 01:58 PM But I will say that oxidation cannot occur on the surfaces. It again goes back to the incredibly high electric fields it sees inside. It is very extreme, not your typical vacuum conditions 08-Dec-18 02:08 PM I know it's a bit crazy, but accelerator structures a bit unique for vacuum prep, primarily to field strengths seen inside. The precautions go a long way in ensuring optimal performance. Especially since they often produce data that is used as a standard for the physics community 08-Dec-18 02:08 PM Not all accelerators are this intensive, but larger and higher power machines generally require more careful prep 08-Dec-18 02:10 PM it's not really unique, if you look at the video it is pretty standard, which is why I circlejerk that point so much, they dip them, dry them and then pump them down for storage and transport 08-Dec-18 02:10 PM and at the target site they uncap them and assemble and then pump 08-Dec-18 02:10 PM nothing special in general 08-Dec-18 02:10 PM all of our systems came that way 08-Dec-18 02:10 PM then you assemble them, pump again and act suprised at how dirty they were in general although they already were baked at the factory 08-Dec-18 02:10 PM bright dipping aka chemical polishing really helps there as it decreases your surface area, but still 08-Dec-18 02:16 PM They are not unique from the pumping standpoint, but field strength standpoint. again it depends on the system. Higher field strength research accelerators need better conditioning. Does your MBE systems use a linac? Just curious, since I don't know much about MBE. 08-Dec-18 02:16 PM The older systems had more tolerance to them, but the newer structures tend to get increasingly complex due to the ability to further optimize their performance 08-Dec-18 02:19 PM well, if one would be pedantic, yes there is a linac in there, but no it is just a high current ebeam source 08-Dec-18 02:19 PM the rheed and leed also have an e gun in there 08-Dec-18 02:19 PM the rheed is really useful after you understood how it works and what you see 08-Dec-18 02:28 PM I think that may be the difference though between prep requirements, or at least why they go through so much extra effort in the accelerator field. It sees multi-MV equivalent field strengths on complex geometries in confined spaces. With intensities like that, any contamination at all is bad. If a structure arcs inside, it can damage the structure and impede performance. Though that's also why we rf condition each section for like weeks on its own before installing it on the main beamline. Slowly bring up power to prep the surfaces. I do agree it is probably overkill, and may not always be required, but just sharing my experience from the field talking to the engineers who design them. If anything, our old system is in fact a testament that they can be catastrophically contaminated, opened up, and cleaned to work again, but they had a lot of odds against them. Just for reference, what us rheed and leed? 08-Dec-18 02:37 PM One thing I will say that definitely can't be exposed to air for more than a few of minutes is the cathode emitter, at least the style we use. Air will poison and ruin it. Very briefly during installation is fine, but it's gotta be very fast otherwise it's ruined. They are LaB6 high current dispenser cathodes 08-Dec-18 02:53 PM electron diffraction 08-Dec-18 02:53 PM at different energies 08-Dec-18 02:54 PM I'm back! 08-Dec-18 02:55 PM it is very useful as you can do it in situ and see what the surface of the wafer looks like 08-Dec-18 02:56 PM what can you do in situ about the wafer surface? 08-Dec-18 02:58 PM Nice! 08-Dec-18 02:59 PM well, we're doing MBE 08-Dec-18 02:59 PM so we're putting stuff onto the surface 08-Dec-18 02:59 PM AH! Oh...huh... 08-Dec-18 02:59 PM goes elsewhere 08-Dec-18 03:00 PM the thickness metrology is also pretty neat 08-Dec-18 03:00 PM we use EIES which is basically a triode ionizing the chambers contents and then a PMT + narrowband filter to look at the spectra 08-Dec-18 03:00 PM and the rate is roughly linear with the intensity 08-Dec-18 03:27 PM What's the main application of the work you do? A particular industry or specific product, or is it more you do deposition of various materials based on a customer request? Or is it more research based? 08-Dec-18 03:27 PM it depends™ 08-Dec-18 03:27 PM lurks around 08-Dec-18 03:27 PM no, we specialize in certain materials 08-Dec-18 03:31 PM (stupid question for when you two finish: If I have boron vapor, can I accelerate it in any way? (like in an ion implanter) 08-Dec-18 03:31 PM What's the end goal? 08-Dec-18 03:31 PM How high acceletation? 08-Dec-18 03:32 PM taking into account that an ion implanter requires very high energy, ion implantation in the far future. 08-Dec-18 03:32 PM I should ask, what penetration depth onto your target 08-Dec-18 03:32 PM if you want to make devices, use diffusion 08-Dec-18 03:32 PM (but not pinpoint implantation, just bulk) 08-Dec-18 03:33 PM Goes back to the depth and the target 08-Dec-18 03:33 PM I'm on diffusion now. Just wondering out of curiosity ^^ 08-Dec-18 03:33 PM (my oven is super nice ) 08-Dec-18 03:33 PM Yes, you could certainly make a boron plasma and extract ions from the plasma 08-Dec-18 03:34 PM Thanks ^^ 08-Dec-18 03:34 PM I just wanted to know if it was possible at all. 08-Dec-18 03:34 PM might need too much work for what I want to do anyways. 08-Dec-18 03:35 PM Oh yeah lol, you can get ion sources really from anything. 08-Dec-18 03:35 PM Depends on what you want to do with it after that makes it easy or difficult 08-Dec-18 03:37 PM In whole, implant Boron or Phosphor in a non doped wafer, so I can avoid having to do wells from one type or the other and then diffuse on top of that. 08-Dec-18 03:37 PM good luck getting an undoped wafer 08-Dec-18 03:38 PM I thought I had seen them for sale in "normal" supliers for research 08-Dec-18 03:38 PM they are around 08-Dec-18 03:38 PM (might be wrong) 08-Dec-18 03:38 PM but if you really want to make devices you just get doped ones 08-Dec-18 03:38 PM How deep and what concentration? When you get to that stage, SRIM is your friend lol 08-Dec-18 03:39 PM I'll kidnap you if I get to that stage. 08-Dec-18 03:39 PM XDDD 08-Dec-18 03:39 PM If I manage to do the glass e-beam litography machine, I think I'll be satisfied. 08-Dec-18 03:39 PM oh god, srim 08-Dec-18 03:39 PM the flashbacks 08-Dec-18 03:40 PM (SRIM noted) 08-Dec-18 03:41 PM SRIM is amazing, I love using it 08-Dec-18 03:41 PM oh, and PV wafers off ebay are really iffy for stuff apart from PV 08-Dec-18 03:41 PM If u use it, go with the 2013 version 08-Dec-18 03:41 PM What worries me now is if I can put a viton-oring "near" the filament of the electron gun, and get away with it, so I can make it removable. 08-Dec-18 03:41 PM (noted, double) 08-Dec-18 03:41 PM (the glass filament holder, I mean) 08-Dec-18 03:43 PM the carrier lifetime in them is really bad compared to semi ones and depending on the process they were supposed to go in they might be the wrong dopant 08-Dec-18 03:44 PM It depends on your overall gun design 08-Dec-18 03:44 PM And vacuum level needed 08-Dec-18 03:44 PM I can use viton with my system cause it can use garbage vacuum and thrives on contamination practically lol 08-Dec-18 03:44 PM For your application, it's probably more stringent 08-Dec-18 03:45 PM viton is not so bad, but I would not go above 100°C or so with it 08-Dec-18 03:45 PM I know I don't need metal seals. and the gun, I wanted to steal as much as possible from already made hardware (CRT's and /or Vidicon tubes) 08-Dec-18 03:46 PM the big lids on our chambers are viton sealed 08-Dec-18 03:46 PM Yeah, you can get away with viton 08-Dec-18 03:46 PM I'm guessing you don't need very high voltage or current gun? 08-Dec-18 03:47 PM The viton oring doesn't have to sit exactly near the filament, everything can be made longer, te idea is to not have to handle the electron optics, but be able to change the filament when it fails, by removing the back piece. 08-Dec-18 03:47 PM yeah that is probably fine 08-Dec-18 03:47 PM neither, I plan to be at 2Kv max, to use the whole of the electronics in a CRT scope. 08-Dec-18 03:47 PM but you might have alignment issues 08-Dec-18 03:47 PM You should be fine, just post the design if you have concerns! 08-Dec-18 03:48 PM from the filament to the cup it resides in, right? (the alignment issues) 08-Dec-18 03:49 PM from the filament to the rest of the electron system 08-Dec-18 03:51 PM I hadn't considered that. How do real electron microscopes deal with that? super fancy correction stages ? 08-Dec-18 03:55 PM What is the egun for again for your system? 08-Dec-18 03:55 PM Getting hard to keep track of everything lol 08-Dec-18 03:55 PM Can you rephrase that? 08-Dec-18 03:55 PM ah, what I'm doing? 08-Dec-18 03:55 PM I want to make an e-beam litography machine for 30 micron linewidth. But without the need for a true electron microscope. 08-Dec-18 03:55 PM (for making devices, of course) 08-Dec-18 03:58 PM Yeah you will have to consider optics for that 08-Dec-18 03:59 PM consider optics? 08-Dec-18 03:59 PM Electron beam optics, like factor that into your design 08-Dec-18 03:59 PM Steering, focusing, correction, etc 08-Dec-18 03:59 PM That's the repurposed Vidicon tube for. 08-Dec-18 04:00 PM Ok, makes sense then, not doing it from scratch 08-Dec-18 04:00 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Vidikon-181E8.png 08-Dec-18 04:00 PM http://www.rapp-instruments.de/NewsPage/Vidikon/vidikon.htm 08-Dec-18 04:00 PM But the filament will ear out quickly even if mantained with Helium. 08-Dec-18 04:00 PM so I want to remove it from the glass it comes out, and make one with anular connections. and a removable glass endcap. 08-Dec-18 04:00 PM to change filaments as needed. 08-Dec-18 04:00 PM the vidicon results: 08-Dec-18 04:00 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/scanning-electron-microscope-vidicon-tube-8581B.png 08-Dec-18 04:00 PM his supposed schematic 08-Dec-18 04:00 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/aufbau-6BA6E.png 08-Dec-18 04:00 PM Hopefully I can achieve that resolution level, wich would be perfect for making devices. Smaller than that starts to require ion etching and weirder stuff. 08-Dec-18 04:25 PM Makes sense. Best way is just experiment, see what happens! 08-Dec-18 04:26 PM Yeah! Next year. 08-Dec-18 04:26 PM I have to figure the glasswork feedthroughs. 08-Dec-18 04:44 PM @Nixie I'm guessing the main reason for the spiral cooling tube in diffusion pumps is greater thermal efficiency, since it can operate with a higher temperature rise. Water comes in at the top, hi vac inlet (or cold cap), then winds down, ending up on the discharge tube. As pressure increases you don't need as low a temp to condense. 08-Dec-18 04:47 PM Sounds right. It's just that to do that at home gives me a headache. I feel it's easier to make a detachable jacket for a home project. 08-Dec-18 04:47 PM (I'm very lazy for somethings) 08-Dec-18 04:51 PM tbh wrapping a length of copper around a piece of stainless and then brazing it on doesn't sound too involved to me 08-Dec-18 04:51 PM If you know how to braze. XDDD 08-Dec-18 04:51 PM But doesn't the tube to braze have to be flattened on the inside edge? 08-Dec-18 04:51 PM for a good contact? 08-Dec-18 04:51 PM Also, the jacket wouldn't provide a better water flow and cooling? 08-Dec-18 04:52 PM eh, if you just put in a lot of braze it is going to be fine 08-Dec-18 04:52 PM ah 08-Dec-18 04:54 PM on the subject of diff pump cooling, i did a thermal study looking at my diff pump and baffle setup: 08-Dec-18 04:54 PM I probably would not even bother with silver containing fillers, just brass will do 08-Dec-18 04:54 PM http://appliedionsystems.com/portfolio/steady-state-thermal-analysis-of-a-high-vacuum-diffusion-pump-and-baffle-assembly/ 08-Dec-18 04:54 PM brazing the lines on the outside should be pretty straightforward, don't thin it needs to be anything too crazy, as long as you just have solid contact between the line and the wall 08-Dec-18 04:57 PM Interesting. i'm thinking that for my future attempt at a diff pump. I would like to make the baffles fixed to the top, and a removable bottom. 08-Dec-18 05:04 PM Some shots to get an idea of gradients. Study probably isn't perfect, but gives decent estimate with the resources I had: 08-Dec-18 05:04 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/8in_Baffle_Cross_Sectional_View_-_Cooled_2-B0D36.jpg 08-Dec-18 05:04 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Edwards_EO4_Diffusion_Pump_Thermal_Analysi-5A7AD.jpg 08-Dec-18 05:04 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Full_Model_thermal_Analysis_Overview_-_Cro-79D32.jpg 08-Dec-18 05:04 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Full_Pumping_Stack_Zoomed_Scale_-_Cooled_B-CA0C3.jpg 08-Dec-18 05:04 PM Stack was omitted for simplicity, but thermal transfer due to oil spray on the walls was accounted for. Also includes 175mL fill of DC-705 at the bottom 08-Dec-18 05:06 PM Just imagining, what would happen if you put liquid nitrogen or in the baffles? 08-Dec-18 05:06 PM or something cryo, I mean 08-Dec-18 05:06 PM LN2 baffle is common tho 08-Dec-18 05:06 PM I mean, for his calculations. 08-Dec-18 05:07 PM liquid nitrogen would be nice to cool the baffle. It would defintely eliminate all backstreaming at that point, and act as a cryo pump. This one is just a standard water cooled one from ebay 08-Dec-18 05:07 PM nice big 8" i got for $100 off ebay, practically new conditio 08-Dec-18 05:07 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/8in_Water_Cooled_Baffle_-_Resized-4DD34.jpg 08-Dec-18 05:08 PM Woah. 08-Dec-18 05:08 PM Could you run the LN2 into the diff? or would that be too much cooling? 08-Dec-18 05:09 PM My vacuum simulations also verify the efficiency of the baffle at 65-68%, which shows it is a very well design baffle. Pipeline is optimized for speed in my system. A good baffle should be about 60% efficient 08-Dec-18 05:09 PM lowest temp is usually 15C for diff cooliing 08-Dec-18 05:09 PM okay, too much. 08-Dec-18 05:09 PM you dont want to go lower, too low and the oil won't heat properly 08-Dec-18 05:09 PM XD 08-Dec-18 05:11 PM but you could probably circulate LN2 through the baffle. though 15C with quality oil is sufficient to get rid of most backstreaming 08-Dec-18 05:12 PM Don't take anything I ask too seriously, I'm just looking at what happens in the extremes with tooling. 08-Dec-18 05:37 PM time to go, Gnait! 08-Dec-18 05:39 PM Night! 08-Dec-18 10:57 PM Joined the server. 09-Dec-18 06:57 AM Uhg, bought 4 more shelves for the basement and starting to get some space to work on things... Would love to get back to the HV stuff but man money, time, and clear space are all at a premium these days... 09-Dec-18 06:59 AM clear space? What's that? 09-Dec-18 07:04 AM XDDDDDDDD 09-Dec-18 07:04 AM Space - Money - Time 09-Dec-18 07:04 AM You can only pick two. 09-Dec-18 07:06 AM or be a student and get only one 09-Dec-18 07:08 AM XDD 09-Dec-18 07:08 AM Or have a full time job, do school part time, and be paying multiple loans and have none. 09-Dec-18 07:10 AM Fun! 09-Dec-18 07:13 AM Dang. 09-Dec-18 07:13 AM Well, allow me to throw some fun in here: I'm 3D printing on metal with my TIG welder on my aluminium endplate to "grow" the pegs to hold the targets for sputtering. 09-Dec-18 07:13 AM Much easier than trying to actually weld machined pegs on the same place. 09-Dec-18 07:13 AM (one minute for Falcon 9 launch at link in #off-topic-thats-sometimes-on-topic ) 09-Dec-18 07:16 AM Saw that @Nixie lol looking good considering what the heck you are doing XD 09-Dec-18 07:18 AM Hey, it's working...sooo... Shame I don't have better aluminium inserts (those are triangulars, haven't bought them yet). but finish is good enough with a spring pass. 09-Dec-18 07:18 AM Meanwhile the plate cools with 2 grown pegs, I'll watch the launch. 09-Dec-18 07:18 AM go! 09-Dec-18 07:18 AM (the rocket) 09-Dec-18 07:18 AM Talking about rockets, The other day I heard scott manley saying that the pneumatic piston SpaceX uses to push the second stage, does it pushing on the top of the combustion chamber. That made me wonder, combustion chambers have a grid of injector nozzles, wouldn't pushing there risk damage to them? My head keeps saying they push the throat of the engine, instead. 09-Dec-18 07:26 AM Rip the first stage 09-Dec-18 07:27 AM Wait... am I seeing a repeat of the other day, or have they just had the same failure TWICE?? 09-Dec-18 07:27 AM did that happen the other day too? 09-Dec-18 07:27 AM jeez 09-Dec-18 07:27 AM yes, as far as I know. 09-Dec-18 07:27 AM I'm a bit confused. 09-Dec-18 07:27 AM lol that cheering so fake 09-Dec-18 07:27 AM added on top 09-Dec-18 07:27 AM YEAHHHHH....YAAAAAAAYYYY 09-Dec-18 07:27 AM WOooooHOOOOOO 09-Dec-18 07:27 AM XDDDD 09-Dec-18 07:28 AM water landing haha sure 09-Dec-18 07:28 AM They just have had the same failure 09-Dec-18 07:28 AM guess they saved it from crashing into land 09-Dec-18 07:28 AM and cut the video feed as the stage started spinning. 09-Dec-18 07:28 AM It is a safety measure. Until it is good to land, it stays on top of water. 09-Dec-18 07:30 AM yea, ok. 09-Dec-18 07:30 AM so it does that on purpose when it decides, nope, not going to land on land 09-Dec-18 07:34 AM Yeah. 09-Dec-18 07:34 AM I just tweeted elon musk. XDDDD 09-Dec-18 07:34 AM not going to even read my tweet, but whatever. 09-Dec-18 07:34 AM Let's go grow some aluminium pegs! 09-Dec-18 08:21 AM about what? 09-Dec-18 08:21 AM "i like your GF"? 09-Dec-18 10:24 AM No, about the second failure and bad triyng at covering it up 09-Dec-18 10:24 AM btw, I don't even know who his gf is 09-Dec-18 10:55 PM "Moin-ing" everyone! \o/ 09-Dec-18 11:56 PM o/ morning 10-Dec-18 01:27 AM Good morning! 10-Dec-18 01:27 AM uhh, new video by krasnow 10-Dec-18 01:49 AM It was great, I didn't like the amazon sneaky advertising, though. 10-Dec-18 01:50 AM if you see it like that it was advertisement for tek and keithley as well 10-Dec-18 01:50 AM oh, and I see a digikey ruler! 10-Dec-18 02:01 AM 10-Dec-18 02:03 AM yeah, that's how those laser mouses are working 10-Dec-18 02:04 AM ??? I thought they had a motion detector sensor. 10-Dec-18 02:04 AM Woah...now that you say it 10-Dec-18 02:09 AM Next up on applied sciences: Using a $1 lasermouse as interferometer for an AFM 10-Dec-18 02:12 AM With sneaky advertising from someone. 10-Dec-18 02:16 AM You've got a weird Definition of Advertisement 10-Dec-18 02:16 AM why would he advertise for amazon if he dosen't get any money from them? 10-Dec-18 02:35 AM @Nixie no, those laser sensors like the "twin eye" sensor are using self mixing of the laser 10-Dec-18 02:35 AM for laser doppler interferometry and if you sum/integrate that up, you've the relative position moved 10-Dec-18 02:35 AM http://www.photonics.philips.com/application-areas/sensing/laser-sensors/human-input-devices 10-Dec-18 02:43 AM Not that we know of. He could have put the batteries sideways. 10-Dec-18 02:43 AM I'm still annoyed about his 5 minute plug of the EL paint at the superconference. 10-Dec-18 02:43 AM don't take me seriously. 10-Dec-18 02:43 AM (otoh, I think I fixed my microphone, hopefully. The nice one) 10-Dec-18 02:44 AM Yeah! 10-Dec-18 02:44 AM @N00N amazing. 10-Dec-18 02:44 AM If I didn't fix it, at least now I know how to open the mouthpiece, so I can exchange the electret sensor if needed. 10-Dec-18 02:44 AM but so far so good. 10-Dec-18 02:44 AM I would still love to get my hands on the sensor of the wii nunchuck that tracks IR sources. 10-Dec-18 02:44 AM (sort of related to sensing and sensing devices) 10-Dec-18 02:47 AM just buy a wiimote ^^ 10-Dec-18 02:48 AM and learn SPI or I2C first... 10-Dec-18 02:48 AM ¬¬U 10-Dec-18 02:48 AM SPI/I2C isn't too bd 10-Dec-18 02:48 AM serial programming is just...my head understands it, but my programming skillls are not up to par 10-Dec-18 02:48 AM fair 10-Dec-18 02:49 AM (my programming skills suck...to be frank) 10-Dec-18 04:58 AM Joined the server. 10-Dec-18 05:00 AM Yeeee 10-Dec-18 05:00 AM OiD is a friend of mine, he doesn't come from twitter. But has an impossible cluttered workshop as anyone else in here. 10-Dec-18 05:01 AM Welcome! 10-Dec-18 05:01 AM Hi y'all! 10-Dec-18 05:01 AM First time in discord so I'll try not to mess things up... No promises 10-Dec-18 05:02 AM no worries 10-Dec-18 05:04 AM Just as Nixie said, clutter is the way. I do all sorts of stuff from low voltage, low power to high voltage and high energy 10-Dec-18 05:05 AM Show your transformers 10-Dec-18 05:05 AM XDDD 10-Dec-18 05:06 AM https://images-na.ssl-images-amazon.com/images/I/61-Vf1z%2BfSL._SL1100_.jpg 10-Dec-18 05:06 AM The group rules stated no lewds... 10-Dec-18 05:07 AM lewds of the other kind 10-Dec-18 05:07 AM no fleshy lewds 10-Dec-18 05:07 AM tech pr0n is totally fine. 10-Dec-18 05:07 AM I would even say, mandatory. 10-Dec-18 05:07 AM yep. 10-Dec-18 05:08 AM Let me crawl out from under this printer first 10-Dec-18 05:08 AM XDDD 10-Dec-18 09:20 AM first set of molecular flow simulation results released. This first series of simulations deals with the Integrated High Vacuum Test Stand diffusion pump assembly, looking at the comparison of 3 different levels of conditioning. I will release a set of data each day. The simulations were done using the free software Molflow+ from CERN. This first result looks at average molecular trajectories in the blanked off system: 10-Dec-18 09:20 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Integrated_High_Vacuum_Pump_Assembly_-_Mol-6024F.jpg 10-Dec-18 09:20 AM Input pumping speed from the pump is 600 l/s, resulting in a final speed at the chamber inlet at the blank-off of 392-408 L/s for the 3 simulations, resulting in a baffle efficiency of 65-68%, validating optimal design for an optically-opaque water cooled baffle (no direct line of sight between the pump and the chamber). 10-Dec-18 09:20 AM To better see the trajectories, here is a shot with reduced line counts: 10-Dec-18 09:20 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Integrated_High_Vacuum_Pump_Assembly_-_Mol-28F4D.jpg 10-Dec-18 09:20 AM from the results, you can see that a large fraction of interactions occurs between the upper and lower baffle fins, which is expected due to the indirect pumping path set up by the baffle geometry. This exemplifies the mechanism of baffles in dealing with particle backstreaming 10-Dec-18 09:20 AM tomorrow and Wednesday I will go over actual pressure results, showing the difference in ultimate pressure in the system for 3 different preparation cases: unbaked/pump <1hr, unbaked/pumped >24hr, and baked/pumped >24hr. This is particularly important for this system due to the several viton-o-rings used in the system. 10-Dec-18 09:20 AM after this system result walkthrough, I will move on to results for the small 2.75" conflat based full chamber, and the micro-propulsion testing chamber. Once my engine and accelerator designs are complete, I will then go back and do simulations for dynamic loading of the system from these sources. 10-Dec-18 09:38 AM As a general note, a baffle still needs to be cooled to minimize backstreaming. As observed, particles will continue to bounce around on wall surfaces until they stick, backstream, or are pumped out. The oil vapor needs to condense when it comes in contact with the baffle surface so that it does not migrate upwards. However, the indirect line of site and large surface area of the fins helps increase the probability of interaction dramatically, while maintaining high throughput. 10-Dec-18 09:42 AM 10-Dec-18 02:57 PM hm, interesting. looks like McCryoT is used for, e.g., cryopump sorption modeling? And it looks like SynRad can model desorption.. at least from skimming 10-Dec-18 02:57 PM that's kinda neat. really need to sit down at fusion 360 and staple my vacuum system together out of KJL's STLs 10-Dec-18 03:02 PM Go, fusion, go! 10-Dec-18 03:10 PM SynRad is used for modeling synchrotron radiation, though I think desorption is an output as well. These results aren't as interesting as the pumping profile curves I will post tomorrow 10-Dec-18 03:12 PM Oh, yeah, I misunderstood/misread the website, angle mapping based desorption is just a thing in MolFlow+ 10-Dec-18 03:13 PM On my project site I will have a description of generating the profiles, as well as results, discussion, and all the simulation files 10-Dec-18 03:13 PM I did spend the time first to hand calculate out everything so I know what to roughly expect, as well as getting familiarized more with vacuum engineering. Total gas load was especially needed for each o-ring for each level of preparation. Molflow has a learning curve, but it's not bad, but u would really recommend going through the fundamentals first before jumping straight into simulations 10-Dec-18 03:18 PM That's fair. I remember your blog postings about your manual vacuum flow rate calculations were the first thing that really caught my eye about your work, however many months ago that was 10-Dec-18 03:18 PM just imagine me mumbling 'wow this person actually knows how to plan out and measure what they're doing' to myself while I shovel entire credit cards directly into the ebay buy-it-now black hole button 10-Dec-18 03:24 PM My calculations are not perfect lol, and do differ from the sim results, though I did add extra correction factors for worst case estimates. Talk is easy, the real test is the doing. Haven't pulled vacuum yet myself, still working towards it. However, even if you don't have money for it, there are always ways to test and engineer the system while you wait to save up. 10-Dec-18 03:32 PM Simulations are not necessary at all for hobby work, but I'd figure since I have the time I might as well try to learn and characterize everything I can about my system, and provide the resources to make it easier for others. CERN doesn't need to be the only one who gets to play with this stuff! 10-Dec-18 03:39 PM fair enough :P 10-Dec-18 03:39 PM I do actually want to learn to do simulations and proper qualification of my hardware, especially as I get into the point where I'd like to be doing/attempting to do any kind of actual research or materials analysis. Just .. need to .. not be so lazy.. 10-Dec-18 03:41 PM I think the only time when I ran an actual calculation was when we were arguing how to improve the cycletime on the load lock 10-Dec-18 03:41 PM I will say it is incredibly powerful and useful 10-Dec-18 03:41 PM Particularly with systems that have process gas loads, or outgassing loads due to orings 10-Dec-18 03:41 PM Or if you have a lot of gases you work with, generating estimation curves for pumping speeds is very helpful so you don't have to go back and recalculate it for each gas every time. For molecular flow, each gas is counted seperate since interactions are dominated by the walls rather than each other, and speeds vary based on molecular weight and temp. 10-Dec-18 09:35 PM anyone know where I can get glass sheets with pre-applied aluminum on one side? 10-Dec-18 09:35 PM or, alternatively, does anyone know a good way to deposit aluminum or some other reflective metal easily and in a uniform manner onto glass? 10-Dec-18 09:35 PM there are a lot of options here actually 10-Dec-18 09:35 PM I guess I should specificy a bit better what the goal is 10-Dec-18 09:35 PM I want to rig up a high-res home pcb system for funsies at some point 10-Dec-18 09:35 PM my thought originally was to use an old photo enlarger we have lying around in my family's basement 10-Dec-18 09:35 PM thing is, the photo enlarger is prolly going to want to go from a negative-sized item and projecct out onto a base 10-Dec-18 09:35 PM so, I guess the question becomes, how do I go from regular photo enlarger to something more PCB oriented? 10-Dec-18 09:35 PM are there photo-negative printers, actually? 10-Dec-18 09:35 PM yeah, noone wants to go the opposite direction, unsurprising. 10-Dec-18 09:35 PM I guess theres always the DLP + X/Y staging option? 10-Dec-18 09:35 PM its still not ideal compared to a simpler process like laser etching.... 10-Dec-18 09:35 PM I should just go the laser-engraver/paint/FeCl3 etch route, huh 10-Dec-18 10:17 PM ugh, ok, so 10-Dec-18 10:17 PM who all is here? because im having some 3d printer issues and i want to run my potential solution by yall 10-Dec-18 10:17 PM basically, I've been messing with a glass bed, and thus far it seems to be working great, but im running into a couple of issues 10-Dec-18 10:17 PM this is PLA, so I shouldnt need an enclosure 10-Dec-18 10:17 PM however, without the enclosure, the bottom layer peels off the rest of the print 10-Dec-18 10:17 PM Im not 100% sure what would cause the first layer not to bond to the second layer, but the rest of the print to bond just fine 10-Dec-18 10:17 PM but, my solution was, once the print is done, to add some end gcode that raises the temperature of the bed to about 80C 10-Dec-18 10:17 PM thats enough to make the PLA of the bottom 2 layers into their amorphous state, methinks? 10-Dec-18 10:17 PM basically, a short anneal for the bottom 2 layers? 10-Dec-18 10:17 PM but im unsure if thats stupid or not 10-Dec-18 10:17 PM ngl it feels kind of stupid, but idk a better solution on this one 10-Dec-18 10:24 PM I never had that problem... Would probably look at your slicer settings first 10-Dec-18 10:24 PM how would slicer settings affect this? 10-Dec-18 10:24 PM its not like its jumping up higher than before on the last 2 layers 10-Dec-18 10:24 PM *on the 2nd layer 10-Dec-18 10:24 PM ill try the anneal, i think that might work 10-Dec-18 10:27 PM Like maybe it could have been configured to use the cooling fan on the first two layers or something. 10-Dec-18 10:28 PM oh yeah I did have it do that, mostly to just keep the DII cooling shroud from melting 10-Dec-18 10:28 PM I guess I could try turning it off, worst case I just print another one. 10-Dec-18 10:30 PM I just kinda remove my cooling shroud because it was not working right. Having some stringing but it's manageable 10-Dec-18 10:31 PM im having a lot of stringing, which is what im trying to solve 10-Dec-18 10:31 PM *one of the things im trying to solve 10-Dec-18 10:31 PM ive just been printing a bunch of cubes trying to balance the retraction length and speed etc 10-Dec-18 10:31 PM was printing too hot before, and the result was a lot of stringing, now ive gone from stringing to ooze, which is a step forward 10-Dec-18 10:31 PM but still not ideal 10-Dec-18 10:31 PM ive got a lot of stuff to work out on this printer tbth. I think part of the issue is just that the hot end blows 10-Dec-18 10:34 PM Is it one of those reprap v8 ones? 10-Dec-18 10:34 PM Morning! \o/ Hmmm @OiD might know something about layer adhesion. 10-Dec-18 10:34 PM no idea, this is a monoprice maker select plus 10-Dec-18 10:34 PM it gets the job done for a lot of things to some extent, but not well at all for anything fine or structural 10-Dec-18 10:35 PM Maybe stop the fan for the first layer? 10-Dec-18 10:35 PM yeah thats what im about to try 10-Dec-18 10:35 PM im also thinking about just completely replacing and rebuilding the hotend and extruder assembly at some point 10-Dec-18 10:35 PM the stepper motor seems fine, but the rest is... debatable 10-Dec-18 10:36 PM Can't hurt to do it. 10-Dec-18 10:36 PM on the last printer I was working on i bought this weird extruder head called the hexagon that was really well reviewed and tbh I really did like it 10-Dec-18 10:36 PM i got some really decent prints out ofthat 10-Dec-18 10:36 PM id swap that in but i don't have it here 10-Dec-18 10:36 PM ill think about ordering myself another one for christmas and designing a new extruder assembly around that 10-Dec-18 10:36 PM I think it was a J-head extruder? 10-Dec-18 10:36 PM it wouldnt surprise me if that would help, honestly. part of the issue with this one is that the heat dissipation element is /tiny/ 10-Dec-18 10:36 PM so you have a lot of hot filament a significant length up the extruder shaft 10-Dec-18 10:39 PM Heat disipation element, you mean the temperature separator? 10-Dec-18 10:40 PM idk if thats what its called, but im talking about the uh 10-Dec-18 10:40 PM the 10-Dec-18 10:40 PM hm 10-Dec-18 10:40 PM words 10-Dec-18 10:40 PM heatsink! 10-Dec-18 10:40 PM the heatsink shaft that sits about the heater block 10-Dec-18 10:40 PM Yes. You both mean the same thing 10-Dec-18 10:41 PM *above the heater block 10-Dec-18 10:41 PM i had never heard the term temperature separator before 10-Dec-18 10:41 PM TIL, I guess 10-Dec-18 10:41 PM I got it from the top of.my head, its pobably not called that way, sorry. 10-Dec-18 10:42 PM yeah, the monoprice printer has no separator, basically 10-Dec-18 10:42 PM That can seriously affect, yes. 10-Dec-18 10:42 PM the extruder wheel is almost right above the heat element 10-Dec-18 10:43 PM The cetus I have has a teflon lined long heatsink that works wonderfully. 10-Dec-18 10:43 PM (omg, I have to buy replacwments!) 10-Dec-18 10:43 PM all they have for reducing heat between the extruder gear and the heating block is a little block of metal weakly attached via screws to a heatsink 10-Dec-18 10:43 PM and that heatsink is really small 10-Dec-18 10:44 PM That doesn't sound like much 10-Dec-18 10:44 PM XD 10-Dec-18 10:44 PM no, its really not 10-Dec-18 10:44 PM Cant you just make a bigger block? (Probably not due to space, but i'll ask anyways) 10-Dec-18 10:45 PM not the way its designed, no, i dont think so 10-Dec-18 10:45 PM Can you post a photo of the culprit? 10-Dec-18 10:45 PM later, its printing rn 10-Dec-18 10:45 PM ill pick this back up tmrw 10-Dec-18 10:45 PM i think it would probably be a good idea to just design a whole new extruder assembly, honestly 10-Dec-18 10:45 PM along with a new hot end 10-Dec-18 10:58 PM I guess this is the standard assembly on prusa-style printers??? 10-Dec-18 10:58 PM I kinda think it's still probably a culprit tho 10-Dec-18 11:13 PM No idea. :/ 11-Dec-18 01:13 AM yawn Good morning! 11-Dec-18 01:29 AM Moin-ing! 11-Dec-18 02:51 AM Morning all! 11-Dec-18 02:51 AM I'm up to hear with 3dp... Really wish i could just have a 3DJetfusion at home... 11-Dec-18 02:51 AM I use an enclosure for my delta and the heated bed. Not sure if turning of the bed is a good idea as the thermal shrinkage can cause the print to pop right off 11-Dec-18 02:51 AM On the other hand, I'm in the middle of converting a Stratasys uPrint to open source. It's hell on wheels... 11-Dec-18 02:51 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG-20181201-WA0008-320FA.jpeg 11-Dec-18 04:58 AM \o/ 11-Dec-18 06:19 AM @Applied_Ion so when you talk about the o-rings effect and bake or not, is that something that molflow+ does? You also have numbers in your hand calculations for water desorption rate, etc. Where did those numbers come from? 11-Dec-18 06:46 AM @robamacl no, for generating the pressure for each simulation case, I had to run 3 different simulations. In each one, I had to manually apply outgassing loads for each material based on the method of preparation. So for all materials in the model, including the o-rings, I found average numbers in literature for outgassing rates of unbaked vs baked. In this case there are so many different numbers listed there isn't really a definitive right or wrong, more of an estimated range. I also factored in permeation as well, which contributes to a small part of the total initially. However, in the calculations you see that for higher vacuum levels, permeation loads begin to dominate. Unfortunately, even with baking, viton will still continue to outgas and have permeation. For the large diameter orings I am using, this adds up fast for the surface area and material length. While baking in this case doesn't really improve vacuum levels, what it does do that is not shown in the simulations is significantly reduce the time required to get to its ultimate vacuum level. Until UHV levels around 10^-8, it is generally assumed that water vapor is your primary outgassing load source. After this, hydrogen usually becomes the dominant gas load. Molflow works by assigning various parameters to the facets that are generated in the model. So outgassing, gas loads, and pumping rates must be applied manually for each facet. Loads can be either input as either mbar x l/s or as mbar x l/s/cm^2. I do have all of the final values listed for each facet for every simulation. How I calculated these numbers can be found in documentation I have also posted for the primary system overview. 11-Dec-18 06:46 AM Again, the calculations are not perfect, and should not be taken as absolute numbers, since vacuum systems are too variable to accurately account for everything, but give decent order of magnitude estimates of what to expect, and are within reason of what can be expected for the technology I am using 11-Dec-18 06:46 AM Permeation for elastomers can be reduced with a few methods. Severe over compression (which I am employing for one o-ring) and temperature. As temp decreases for the bulk material, permeation decreases, as the governing equation for permeation is directly related to temperature. A third method is employing a concentric outer "shield" oring, and pumping a channel between the two to about 10 torr, effectively reducing permeation. This technique is used mainly for systems that have huge oring diameters that need to get to high vacuum levels, not as practical for small systems. 11-Dec-18 07:12 AM I've got a few reference books that were bought used online for a few dollars that go really in depth in the mechanics of vacuum engineering and things like desorption that I would highly recommend anyone wanting to dive deeper into the field to grab. I will post the titles in the resources section. 11-Dec-18 07:37 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181211_083701-D77FC.jpg 11-Dec-18 07:41 AM So Long, and Thanks for All the Fish or I must go, my planet needs me! I can't decide. 11-Dec-18 10:28 AM Okay, stupid question: Is there any reason against using this type of coolant on my sputtering system? (using distilled water with drops of algae killer, now) https://www.youtube.com/watch?v=d25OksZMe4I 11-Dec-18 10:28 AM I don't think so 11-Dec-18 10:44 AM Red....I want red... 11-Dec-18 10:44 AM https://www.youtube.com/watch?v=nbW1u9T_Su8 11-Dec-18 10:46 AM looks very nice! 11-Dec-18 01:56 PM I think it is said that they can clog the system but really I don't see a reason why you could not 11-Dec-18 01:56 PM although I would just use straight tap water with antifreeze 11-Dec-18 02:00 PM I have been using just distilled water with maybe 25% clear undyed inhibited propylene glycol. 11-Dec-18 02:00 PM What metals are in your loop? Is it purely just aluminum for the cooled baseplate? 11-Dec-18 02:04 PM I never understood why people insist on distilled, demineralized is fine or even tap water is good 11-Dec-18 02:04 PM because with distilled you are dissolving the apparatus you are putting the water in 11-Dec-18 02:17 PM Demineralized is fine for most stuff. Both are very cheap and available from the grocery store for less than a dollar per gallon. I add the inhibited glycol to help control both growth and corrosion/dissolving. Certain antifreeze can contain silicates that could possibly cause issues, such as being more abrasive to pumps and seals. 11-Dec-18 02:17 PM Best cooling efficiency is straight water. If the coolant tank is small and easy to access, you could always just fill and drain as needed, though not ideal in terms of convenience for closed loop. 11-Dec-18 02:28 PM the silicates are in solution though 11-Dec-18 02:36 PM Over time they can precipitate out. Probably not a major issue, just something to be aware of. There are much less aggressive inhibitors that will do equally well for this application. The conditions in this type of system are way less intense than an engine. 11-Dec-18 02:47 PM or you use silicate free coolant 11-Dec-18 02:48 PM Yeah, lots of options out there 11-Dec-18 02:48 PM Just make sure everything is compatible and you are fine. I learned that at a cost for v1 of my cooling system. Apparently glycol and pvc are not compatible, and will soften the pvc over time. If your loop just has one metal like aluminum, as long as your algaecide is compatible with it (some are not), you could just use demineralized water and algaecide. 11-Dec-18 03:11 PM And carefull with soft vinyl tubing leeching plastisizers 11-Dec-18 03:17 PM Y only use silicone, acrylic and aluminium parts. 11-Dec-18 03:17 PM Right now I use distilled water and anti bacterial aditive. 11-Dec-18 03:17 PM Refrigeration circuit is simple enough: 11-Dec-18 03:17 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181212_002008-4D6ED.jpg 11-Dec-18 03:17 PM Pump -> Inner ring/Outer ring -> Radiator -> Reservoir. 11-Dec-18 03:17 PM (radiator on the right is for oil refrigeration) 11-Dec-18 03:17 PM In any case, I can't seem to find the pearled liquid for sale in my country or at a reasonable price, so I'll get back to distilled water. 11-Dec-18 03:27 PM It might look cooler, but sometimes it's best to keep it simple. Save that money for more fun stuff, like your egun 11-Dec-18 03:29 PM The egun requires about 150€ in parts, a bit out of my reach right now. Had I found the liquid for, say 15€, it was a small treat. 11-Dec-18 03:29 PM (time to sleep!) 11-Dec-18 03:31 PM Good night, nixie! 11-Dec-18 03:38 PM I mostly use PU pneumatic hose and pushin connectors 11-Dec-18 03:38 PM it's just so conventient 11-Dec-18 03:39 PM I read cooling recommendations from induction heater manufacturers. They said 50:50 glycol and distilled (but not DI) water. Auto antifreeze was very bad, caused tubes to clog with black gunk. Apparently DI water is very corrosive to copper. I have heard that from other sources. 11-Dec-18 03:41 PM yeah, but induction heating gets things way hotter than most other stuff 11-Dec-18 03:41 PM I can imagine that that cooks out stuff 11-Dec-18 03:47 PM I thought distilled water was DI too, because the Ions are usually there as salts, which don't evaporate, really, at these temperatures 11-Dec-18 03:50 PM DI water is standard for accelerator structure cooling. Distilled is not quite the same as DI. DI goes through additional purification processes to achieve ultra high purity. Generally a system that uses DI must be closed loop and continually deionized 11-Dec-18 03:51 PM Chiller process water is a surprisingly hard thing to get right 11-Dec-18 03:51 PM Chillers are honestly horrible lol, given me a harder time than my vacuum stuff so far 11-Dec-18 03:51 PM And cost way more than I wanted... 11-Dec-18 03:51 PM DI is also very common in pulsed power for transmission lines, has very high energy density compared with other insulators such as oil. Allows lines of equivalent pulse parameters to be much shorter and store greater energy. 11-Dec-18 04:19 PM we had never an issue with our chillers 11-Dec-18 04:19 PM we just put in tap water 11-Dec-18 04:19 PM twitch 11-Dec-18 04:19 PM it is convenient, and it will never freeze in the lab 11-Dec-18 04:20 PM Oh open loop 11-Dec-18 04:20 PM and we are not replacing the water often enough so that scale would build up 11-Dec-18 04:20 PM no 11-Dec-18 04:20 PM closed loop 11-Dec-18 04:20 PM we have a central chiller plant and then a HX per lab 11-Dec-18 04:20 PM with a pump and thermostatic control 11-Dec-18 04:20 PM so that if something leaks it only leaks like 30l 11-Dec-18 04:20 PM DI is fine if you need the water to be very non conductive, but apart from that tap water or demineralized is fine in my experience 11-Dec-18 10:42 PM what impedance on your DI water do you guys usually get? 11-Dec-18 10:48 PM Morning!! \o/ There is now a machining channel, btw! 11-Dec-18 10:48 PM As far as I knew, DI water is even more clean than distilled water. I happened to have bought about 100L of distilled for when I was about to dilute the 72% HF, but never did it, so, now I have a sort of lifetime supply of that. (Water in the beer chillers I use for the laser and router evaporates eventually, so it's not literally "a lifetime" but a long period indeed.) 12-Dec-18 12:29 AM hi 12-Dec-18 01:29 AM good morning! 12-Dec-18 01:43 AM https://giphy.com/gifs/bear-hello-waving-IThjAlJnD9WNO 12-Dec-18 04:35 AM The problem with DI water and copper is supposedly that it is too clean, it "strips" the copper. Anyway, I'm just running open loop cooling, which can lead to mineral deposits. The Edwards diffusion pump manual suggests yearly descaling such as by 15% HCl followed by 5% sodium carbonate. 12-Dec-18 04:36 AM Interesting procedure. 12-Dec-18 07:14 AM Interestingly, utility-scale inverters used for high voltage DC transmission lines use ultra pure water for cooling, across the 100s of kv potential. But they are also very careful with managing the potential, using platinum electrodes to intercept the residual current that does flow, to avoid electrolytic corrosion. As to issues with induction heating compatibility with auto antifreeze, my guess is that it is something other than temperature, since cars have pressurized cooling and run above boiling. More likely the voltage differences. 12-Dec-18 07:14 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181212_101418272_HDR-E5C67.jpg 12-Dec-18 07:14 AM This is an induction heating capacitor (from the University trash). Note the extra cooling tube length to increase coolant electrical resistance. 12-Dec-18 07:14 AM FWIW, it's 1.25 uf. Came with a coil. They don't make the exact model anymore, but IIRC it seemed to be for about 1kw at 100 kHz. No inverter, though. Parallel resonance. 12-Dec-18 07:14 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181212_101926311_HDR-A926D.jpg 12-Dec-18 07:35 AM Induction heaters are awesome. We built one at our lab for some hest fitting parts. We had some interesting test results with steel nuts, like starting to pull out the iron from the half melted nut. I'll have to find a picture of it 12-Dec-18 08:47 AM Ok, so the one on the left literally ignited. Probably some impurities in the steel which seperate out, like the white deposit on the surface. The one on the right, the iron started seperating and pulling out of the nut. 12-Dec-18 08:47 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20181212_114528-75CD6.jpg 12-Dec-18 08:49 AM left one looks like it had a zinc coating 12-Dec-18 08:52 AM It was red hot for a while, then just ignited. Just a random one lying around the lab, not sure what type of nut. The right nut is a lot more fun though to see the iron being seperate out 12-Dec-18 08:53 AM yeah, that really surprises me, since it looks like it was way above the curie temp 12-Dec-18 08:55 AM Induction heaters are lots of fun. Got 2 igbt bricks I've been saving to build a real high power one eventually 12-Dec-18 09:02 AM guess I gotta build one to someday 12-Dec-18 09:02 AM http://www.celem.com/image/Items/PDFs/6_SPec.pdf Got one of those lying around, the 22 nF version 12-Dec-18 09:04 AM Practically speaking, I'd primarily want it for induction brazing 12-Dec-18 09:04 AM Nice! Those pop up on ebay for pretty reasonable, need to get a celem cap sometime too 12-Dec-18 09:05 AM they're on ebay right now, only 11€ per 12-Dec-18 09:05 AM but I guess shipping's gonna kill it for you 12-Dec-18 09:05 AM https://www.ebay.com/itm/232558144579 12-Dec-18 10:11 AM OMG with the nuts. 12-Dec-18 10:11 AM XDDDD 12-Dec-18 10:11 AM DAmmit, why KF-16 4way tees are just 25€, and 5/6 ways are 100€????? 12-Dec-18 10:11 AM (and 3ways are like 22 12-Dec-18 11:39 AM Has anyone here got some experience with step recovery diodes? 12-Dec-18 11:39 AM I need a pulse with as sharp a risetime as possible and I've got a couple SRDs lying around 12-Dec-18 11:39 AM https://journals.plos.org/plosone/article/figures?id=10.1371/journal.pone.0136287 I was going to orient myself on this circuit 12-Dec-18 11:39 AM question is: Do I need the transmission line or is it just pulse shaping? 12-Dec-18 11:39 AM the risetime is important to me, not the absolute pulselength 12-Dec-18 11:51 AM I've done extensive research on DSRDs, or Drift Step Recovery Diodes. My favorite type of semiconductor on the planet 12-Dec-18 11:51 AM Can't buy them unless u have connections to research labs in Russia, but they are amazing 12-Dec-18 11:51 AM What is your end goal with the SRD? 12-Dec-18 11:53 AM bandwidth measurement of scopes 12-Dec-18 11:54 AM Have you worked with ultrafast circuit design before? 12-Dec-18 11:54 AM I just need something with <300 ps risetime and I've got the diodes here, so they came to mind 12-Dec-18 11:54 AM only in the hundreds of ns range 12-Dec-18 11:54 AM I think I know the basics, rest will be learning by doing 12-Dec-18 11:55 AM Oh that's really slow still lol 12-Dec-18 11:55 AM I've got a bunch of papers on SRDs, I'll do some digging 12-Dec-18 11:55 AM They are similar, but different to DSRDs 12-Dec-18 11:56 AM thanks! 12-Dec-18 11:56 AM Geometry becomes a major concern when you start getting subnanosecond 12-Dec-18 11:57 AM I was hoping to go with a ratsnest construction instead of designing a PCB, that's why I'm asking if I can omit the transmission line 12-Dec-18 12:01 PM Transmission lines can be pcb based, line based, or discreet though. I've done lots of avalanche pulse circuits combining fast pcb and short coax transmission lines 12-Dec-18 12:01 PM hm, yeah, I piece of coax might be worth a try 12-Dec-18 12:01 PM They key is minimizing inductance in your circuit connections 12-Dec-18 12:02 PM I know 12-Dec-18 12:03 PM A coax cable is literally how we set the pulse width for our egun pulser amplifier. Different cable lengths on the avalanche pulser set the initial pulse width 12-Dec-18 12:03 PM hold on, I got a great application note here from hewlett packard on SRDs 12-Dec-18 12:03 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Pulse_and_Waveform_Generation_with_Step_Re-1115B.pdf 12-Dec-18 12:03 PM lots of great design and application info in it 12-Dec-18 12:04 PM Thanks! 12-Dec-18 12:05 PM it's pretty old, but should have some info to get you started 12-Dec-18 12:06 PM Ha, it's perfect! 12-Dec-18 12:06 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-B7506.png 12-Dec-18 12:06 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181212_210628-4FA7A.jpg 12-Dec-18 12:08 PM most of my other papers are on the high power ultrafast DSRD 12-Dec-18 12:08 PM I do have one more SRD implementation paper: 12-Dec-18 12:08 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/An_Implementation_of_Step_Recovery_Diode-B-213C7.pdf 12-Dec-18 12:08 PM but man, the things that could be done with DSRDs if they were available on Digikey... 12-Dec-18 12:08 PM @Nixie maybe you should try manufacturing one lol 12-Dec-18 12:11 PM why aren't they available? 12-Dec-18 12:11 PM are they just not made in those numbers or is it some legal thing? 12-Dec-18 12:11 PM primarily for military applications. Ultra high power, high rep rate semiconductor based switches for UWB generation. Some stuf in the accelerator world, but they were never manufactured for civilian use 12-Dec-18 12:11 PM they are the semiconductor equivalent of ultrafast spark gap switching 12-Dec-18 12:12 PM so it's similar to the legal situation of krytrons? 12-Dec-18 12:12 PM you can buy some commercial pulser units that have them inside for pulse generation, but not the actual diode itself. that needs special connections to obtain 12-Dec-18 12:12 PM probably, but DSRDs can exceed the voltage handling of krytrons by a lot due to the ability to be stacked 12-Dec-18 12:15 PM oh, wow 12-Dec-18 12:15 PM table-top capable pulsers up to GW range due to the high-voltage subnanosecond pulses they can generate 12-Dec-18 12:15 PM and they can handle extremely high rep rates to boot 12-Dec-18 12:15 PM due to the special requirements of our new linac gun, we actually needed to get a DSRD based pulser due to its high voltage, high current, and high rep rate combined ability in the ns range. Also another major bonus - pulse width can be actively adjusted digitally. No need to use discreet transmission lines to set the pulse width with them. In short, for high power short pulse high rep stuff with full pulse width and amplitude control, DSRDs are quite amazing. 12-Dec-18 12:18 PM ...linac gun? O.o 12-Dec-18 12:19 PM yeah, the electron gun injector for the linac. These diodes are real impressive. Hence why they are my all-time favorite semiconductor device 12-Dec-18 12:21 PM sorry, I don't know much about that topic, you need the high speed stuff in a linac to produce good controlled bunches? 12-Dec-18 12:22 PM no, the bunches are generated in a structure after the gun called the pre-buncher. The short pulses are needed for our linac due to the mode of operation. The gun injects the initial high-current pulse, which is accelerated electrostatically with about -125kv to -150kv, which enters the pre-buncher, then the main accelerator structures 12-Dec-18 12:22 PM contained within that "macropulse" structure are the "micropulse" bunches of electrons that get accelerated 12-Dec-18 12:22 PM our linac is actually very unique in that it operates over a huge range of conditions. Everywhere from microsecond to nanosecond pulses, high average power to short pulse high peak, single shot to many hundreds of hz, over a spread of energy ranges. Its very unusual in terms of linacs, which are almost always single mode machines. We kind of consider it the "swiss army knife" of linacs 12-Dec-18 12:26 PM cool! 12-Dec-18 12:26 PM I'm only familiar with DC tandem accelerators so far... ^^ 12-Dec-18 12:28 PM Even DC accelerators have a huge variety of configurations, you can spend a whole career just studying those itself 12-Dec-18 12:29 PM yep 12-Dec-18 12:29 PM the the one here is getting replaced by a wakefield prototype, so this is going to be interesting... 12-Dec-18 12:31 PM Oh nice! 12-Dec-18 12:31 PM the whole laser facility there looks so much like portal 12-Dec-18 12:32 PM that would be amazing to see. Do you work there yourself? 12-Dec-18 12:32 PM the beamline is directly beneath the floor and the mirrors look like the portal mirror cubes embedded in the ground 12-Dec-18 12:32 PM oh, no, I'm just a student and try to get into whereever I can 12-Dec-18 12:34 PM best way to get involved is often to just jump right in! 12-Dec-18 12:34 PM and if you want to enter the field full time, it definitely helps to make connections and get hands-on experience 12-Dec-18 12:36 PM Tube on the back is part of the laser Beamline, just for scale... 12-Dec-18 12:36 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181013_152420-02914.jpg 12-Dec-18 12:37 PM cool! 12-Dec-18 12:38 PM extremly 12-Dec-18 12:38 PM I'm currently getting into the field of particle accelerators, but one can only do so much in the 3rd semester 12-Dec-18 12:38 PM *detectors, not accelerators >.< 12-Dec-18 12:39 PM is there a program at your school specifically for accelerator engineering? or are you more involved with like a nuclear program? 12-Dec-18 12:41 PM not really, but we've got a 20 MW research reactor used as a neutron source that always needs new engineers 12-Dec-18 12:42 PM we used to have a fantastic undergrad student reactor off campus, but due to politics it was shut down. Now they are building a casino in its place... 12-Dec-18 12:43 PM oh come on... 12-Dec-18 12:44 PM at our linac facility, due to the reactor shut down, we are introducing some student labs that uses the neutrons from the beamline to replace this learning center. Its not the same as raising and lowering the control rods yourself, but it still allows for some neutron based experiments 12-Dec-18 12:44 PM yeah its sad. Everyone in the nuclear department was understandably upset. The reactor is so low power you can walk in while its on 12-Dec-18 12:44 PM less power output than a lightbulb 12-Dec-18 12:45 PM here they're not letting any students control the reactor, as it always runs at full power until the fuel is used up 12-Dec-18 12:45 PM yeah, this was one of I think only a couple in the US where undergrads could fully control the rods and work an actual legit reactor 12-Dec-18 12:46 PM there are some like that in germany, but nowhere near me 12-Dec-18 12:46 PM there's a cute 100 mW one in stuttgart 12-Dec-18 12:46 PM well there's one less here now sadly 12-Dec-18 12:46 PM where students can get a "Nuclear reactor drivers license" ^^ 12-Dec-18 12:46 PM but there are protests to shut that down, too 12-Dec-18 12:46 PM because germany has decided to shut down all commercial nuclear power plants shortly after the japanese npp accident 12-Dec-18 12:46 PM dyno is censoring the name of the city >.< 12-Dec-18 12:54 PM Cool 12-Dec-18 12:54 PM Yep... 12-Dec-18 12:54 PM Tschernobyl isnt censored 12-Dec-18 12:54 PM neither is three mile island 12-Dec-18 12:55 PM The problem is fu*k 12-Dec-18 12:55 PM Without the asterisk 12-Dec-18 12:56 PM yeah, I can see your messages in the bot log 12-Dec-18 12:56 PM I thought that was fixed after the Cockcroft stuff 12-Dec-18 12:59 PM A 100mw student reactor was shut down there too? 12-Dec-18 12:59 PM Did whoever fixed it maybe just whitelist a word? 12-Dec-18 12:59 PM yeah, that may be 12-Dec-18 12:59 PM Finally a correct hit 12-Dec-18 12:59 PM @Applied_Ion no, some people want the 20 MW one near me to go 12-Dec-18 01:06 PM I didn't realize they just decided to shut down everything at once after Japan there. That just sounds phenomenally absurd. 12-Dec-18 01:06 PM it totaly is 12-Dec-18 01:07 PM That's gotta affect job prospects for you being interested in nuclear detection there. Or are you looking to seek work elsewhere after graduating? 12-Dec-18 01:07 PM unless you are staying particle accelerator field 12-Dec-18 01:07 PM I would not mind going abroad, was considering russia 12-Dec-18 01:07 PM but that's still a long time from now 12-Dec-18 01:09 PM Still, the fact that everything is just going down all at once, I am having trouble comprehending the stupidity of it. Not to mention the shear massive investment wasted on decomissioning 12-Dec-18 01:09 PM decon would also be a interesting field, and there will be more than enough after the last npp shuts down 12-Dec-18 01:09 PM yeah, no, there is nothing to understand about it 12-Dec-18 01:09 PM we're starting old coal power plants back up because of the missing power 12-Dec-18 01:10 PM wow... 12-Dec-18 01:10 PM and buy cheap nuclear power from france 12-Dec-18 01:10 PM logic seems to be "if we have no NPPs in germany the radiation from abroad won't make it over the borders" 12-Dec-18 01:12 PM granted, the nuclear field in the US isn't great to get into now. We need more scientists and engineers making these decisions lol, I know I'm preaching to the choir here, but there is just a lot wrong with this picture... 12-Dec-18 01:13 PM there is a lot going wrong here 12-Dec-18 01:17 PM if we ever manage to get fusion reactors running in the future, I'm sure they would face the same exact opposition eventually. Even if there is no risk of meltdown or anything, people will always find some reason to bring it down. 12-Dec-18 01:18 PM yeah, everything associated with the word "atom" here is evil 12-Dec-18 01:19 PM "Österreich ohne Atom" 12-Dec-18 01:19 PM oh god, is that a thing?! 12-Dec-18 01:20 PM what does that mean for non-German speakers? 12-Dec-18 01:20 PM austria without atom 12-Dec-18 01:20 PM and that's not a bad translation, the sentence structure really is that bad 12-Dec-18 01:21 PM is that a legit philosophy being pushed? 12-Dec-18 01:22 PM It's an initiative to shut down all nuclear facilities in Austria, but a lot of the people involved are zealots 12-Dec-18 01:22 PM oh god, greenpeace austria has a page about why nuclear power is bad 12-Dec-18 01:22 PM wow 12-Dec-18 01:23 PM and ouch, the points on that list cause physical pain 12-Dec-18 01:23 PM Im not sure I could even bring myself to read it 12-Dec-18 01:23 PM I mean cost-optimised management of nuclear power plants with inadequate regulations or enforcement of them scares me very much 12-Dec-18 01:23 PM Omg 12-Dec-18 01:23 PM don't worry, there dosen't seem to be an english version 12-Dec-18 01:23 PM http://www.greenpeace.org/austria/de/News/Aktuelle-Meldungen/Atom-News/2015/10-gute-Grunde-gegen-Atomkraft/ for the german speaking masochists here 12-Dec-18 01:24 PM (I'm sure I can't make that thing @GigaSquirrel asked, but is there any graphics I can check about what they are? @Applied_Ion ?) 12-Dec-18 01:25 PM I think there may be some general info buried in old papers I have 12-Dec-18 01:25 PM I think they are conceptually simple semiconductors to make, but no market incentive to make them outside military and physics research 12-Dec-18 01:25 PM Oh sweet found it. Paper by the original guy who created them 12-Dec-18 01:25 PM also another paper that has info for making similar devices 12-Dec-18 01:29 PM similar devices? 12-Dec-18 01:30 PM no never mind, same type, not similar 12-Dec-18 01:30 PM but there are some variations of pulse sharpening semiconductors for high power applications 12-Dec-18 01:31 PM And here am I, thinking about how to test a smd push button... 12-Dec-18 01:31 PM @Nixie here are the papers: 12-Dec-18 01:31 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/New_Principles_of_High_Power_Switching_wit-4433B.pdf 12-Dec-18 01:31 PM Downloading! 12-Dec-18 01:31 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Power_Drift_Step_Recover_Diodes_DSRD-D2E44.pdf 12-Dec-18 01:31 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/New_Approaches_for_Designing_High_Voltage_-E0FEA.pdf 12-Dec-18 01:31 PM I don't know much about semiconductor manufacturing, only applications and research with the devices. You may have a better grasp of what would be involved with them 12-Dec-18 01:33 PM you already seem to have made a diode maybe a PIN diode as a next step? 12-Dec-18 01:33 PM an a SRD after that 12-Dec-18 01:33 PM once you've mastered that you can produce DSRDs in the thousands and sell them to @Applied_Ion 12-Dec-18 01:33 PM Oh man I would buy them for sure 12-Dec-18 01:33 PM problem is, I would need a very high speed scope to do anything practical with them as well... 12-Dec-18 01:35 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181114_181408-CD573.jpg 12-Dec-18 01:35 PM something like... 12-Dec-18 01:35 PM yes. wow. that's not your personal scope is it?! 12-Dec-18 01:36 PM haha, no 12-Dec-18 01:36 PM just saw it at electronica fair and had to take a picture 12-Dec-18 01:36 PM my scope does pretty much exactly 1/100 of that with 1/10 of the power draw 12-Dec-18 01:36 PM it's an awesome feeling to scroll down with the vertical knob, all the way from 100 s / div down to 10 ps / div 12-Dec-18 01:36 PM if you need a faster scope just contact rohde & schwarz, they tend to lend equipment to hobbyists for free, sometimes for years at a time 12-Dec-18 01:43 PM :o 12-Dec-18 01:43 PM A company that supports hobbyists thats refreshing 12-Dec-18 01:44 PM oh, many of the "big players" actually do 12-Dec-18 01:44 PM also many of the extremly small ones 12-Dec-18 01:44 PM you just have to ask nicely 12-Dec-18 01:44 PM at least in my experience 12-Dec-18 01:56 PM wait what. I don't just need a faster scope, I need a scope to begin with. the only one I have is some real old one from the 1950s, and I don't think it really works 12-Dec-18 01:56 PM that would be amazing to have access to a loaner scope for an extended period of time 12-Dec-18 01:57 PM oh 12-Dec-18 01:57 PM I really need one to qualify my accelerator once it is built and ready for beam 12-Dec-18 01:58 PM surviving without a scope is pretty much on the same level as without coffee 12-Dec-18 01:59 PM actually, even before beam. I need to get the pulsed power supply working and tuned well 12-Dec-18 01:59 PM I may start asking around, definitely wouldn't hurt 12-Dec-18 01:59 PM ill need to also build all my instrumentation and calibrate it myself, but that is relatively easy and cheap. Scope is the major accessory needed 12-Dec-18 02:01 PM have you got one at work / do you have experience in using one? 12-Dec-18 02:01 PM if yes: Try to get an older tek / agilent one, because you can get a lot of bandwidth for cheap, of not: maybe go for a rigol one, they're really intuitive imo 12-Dec-18 02:04 PM Yeah, I use them all the time for beam and pulsed power stuff here. But I don't want to use lab ones, need to keep personal and work stuff seperate (if I ever develop something and maybe sell it, the institute could try to hunt me down for using their resources.) 12-Dec-18 02:06 PM fair 12-Dec-18 02:06 PM If I can get a hold of a loaner for free, that would be great to start with 12-Dec-18 02:06 PM of course ^^ 12-Dec-18 02:07 PM I'm still a ways away from needing it, but now that I've gotten into the official design phase I will need one eventually to start testing 12-Dec-18 02:09 PM tbh I can't imagine not having one 12-Dec-18 02:09 PM my scopes have basically replaced my dmms and pretty much everything else 12-Dec-18 02:10 PM Yeah, it's rather hard to be an ee without one. Even my dmm is a lousy cheap one 12-Dec-18 02:11 PM cheap DMMs do well for most things 12-Dec-18 02:11 PM but I would not cheap out on a scope 12-Dec-18 02:11 PM unless you can get one for free, that is ^^ 12-Dec-18 02:15 PM Your faith in my semiconductor results might be a bit too much. XD. As far as I understand you make a diode with a thin barrier in between that is thin enough that breaks when reversed, and being so thin, the conduction is ultrafast. 12-Dec-18 02:15 PM I suspect it's done with epitaxial growth. 12-Dec-18 02:15 PM (havent read the whole of the papers, but I will do it, as far as I can understand) 12-Dec-18 02:18 PM The diodes also need to handle very high voltages and currents as well at high rep rates. Probably quite a challenge all things considered 12-Dec-18 02:18 PM I believe they also rely on some sort of plasma conduction phenomenon internally as well 12-Dec-18 02:22 PM Reached the plasma section, wondered what it means. 12-Dec-18 02:22 PM just give it enough current and it will turn into a plasma 12-Dec-18 02:22 PM Well, once I read the paper, Ill understand it better 12-Dec-18 02:22 PM But don't expect to turn me into a semiconductor seller. 12-Dec-18 02:23 PM ...yet 12-Dec-18 02:41 PM Once you move on to automation@home i'm sure you'll get up to something 12-Dec-18 03:20 PM Hah, u wish. 12-Dec-18 03:23 PM so do you, you just don't know it yet 12-Dec-18 03:34 PM 12-Dec-18 03:34 PM Let me make transistors consistently, and then we will see. (Haven't made one yet) 12-Dec-18 05:18 PM Little bit more results for the Molflow simulations of the pumping assembly. The main purpose is determining the pressure of a system. There are several different ways of viewing this. The first is to use textures to map the pressure on the facets of the model. This example is just the first simulation case for unbaked/pumped 1hr: 12-Dec-18 05:18 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Integrated_High_Vacuum_Pump_Assembly_-_Unb-67E94.jpg 12-Dec-18 05:18 PM scale for reference: 12-Dec-18 05:18 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Integrated_High_Vacuum_Pump_Assembly_-_Nor-AE05E.jpg 12-Dec-18 05:18 PM We can also insert a transparent facet through the model to generate profile pressure plots through the system. For the same simulation case: 12-Dec-18 05:18 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Integrated_High_Vacuum_Pump_Assembly_-_Unb-660B6.jpg 12-Dec-18 05:18 PM The resulting plot is as follows: 12-Dec-18 05:18 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Integrated_High_Vacuum_Pump_Assembly_Final-C9ECF.jpg 12-Dec-18 05:18 PM Molflow splits the measurment plane into 100 equal segments of arbitrary units for the x-axis. The y-axis is in mbar. The plot is oriented from left to right equating to bottom (pump side) to top (blank-off side) for the model 12-Dec-18 05:18 PM The full simulation details, explanations, results, and molflow files can be found here: http://appliedionsystems.com/portfolio/molflow-simulation-of-a-high-vacuum-diffusion-pump-assembly/ 13-Dec-18 12:23 AM Btw, my reviewers have failed me. (joking). Noone catched that the mounting holes where skewed. 13-Dec-18 12:23 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/rpNq7jqL-87FE4.png 13-Dec-18 12:23 AM I am thinking on adding an output to the last counter, so you can daisy chain them and make automatic raster. Opinions? 13-Dec-18 01:02 AM hi 13-Dec-18 01:02 AM morning! 13-Dec-18 01:18 AM moin! 13-Dec-18 02:53 AM Chemical question! 13-Dec-18 02:53 AM I am using a very degraded 2% HF solution to etch my silicon dioxide layer in the semiconductor experiments. It now takes about 15 minutes to etch through 300nm of SiO2. but also seeps through the homemade PMMA resists after that much time. I am wondering if a stronger solution would take the same time to seep through the resist, but etch faster the exposed areas. 13-Dec-18 02:57 AM I think one is a chemical reaction, the other is pure diffusion, so if a higher concentration etches faster it might be worth a shot 13-Dec-18 02:57 AM bc diffusion rate is mainly set by temperature 13-Dec-18 03:05 AM Hmm...can't get my hands on stronger HF right now, but will look for it. 13-Dec-18 09:27 AM @qualia !! 13-Dec-18 09:27 AM explain this 13-Dec-18 09:27 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DuR5ddkVsAAvg9N-F2B53.png 13-Dec-18 09:27 AM like...how does this even exist. 13-Dec-18 09:27 AM what kind of USB can you put in UHV... 13-Dec-18 09:27 AM mind explodes 13-Dec-18 09:43 AM microcontrollers 13-Dec-18 09:43 AM usb feedthroughs are quite common 13-Dec-18 09:44 AM but...are there special UHV compatible cables and such? I can't wrap my head around it. 13-Dec-18 09:44 AM I thought that past HV, you only had feedthroughs and simple wires. 13-Dec-18 09:45 AM you can use stuff like polyimide isolation or directly plug in the pcb 13-Dec-18 09:45 AM but i currently use DE-9 (RS-232 style) feedthroughs 13-Dec-18 09:45 AM for USB and stuff like that 13-Dec-18 09:46 AM Omg... 13-Dec-18 09:47 AM they are cheaper and have more pins 13-Dec-18 09:47 AM https://ific.uv.es/elec/files/PCB-UHV.pdf 13-Dec-18 09:47 AM mmmkay.. 13-Dec-18 09:49 AM yeah 13-Dec-18 09:49 AM here with a price tag https://www.lewvac.co.uk/product/usb-feedthroughs/ 13-Dec-18 09:49 AM https://www.lewvac.co.uk/product/subminiature-c-type-feedthoughs-9-pin/ 13-Dec-18 09:53 AM OMFG 13-Dec-18 09:53 AM XDDDDDDDDDD 13-Dec-18 09:54 AM they are cheaper (the DE-9 ones) 13-Dec-18 09:54 AM https://www.lewvac.co.uk/product/subminiature-d/ i mean, sry 13-Dec-18 09:54 AM they have cables too 13-Dec-18 09:59 AM Impressively high margin products there. 13-Dec-18 10:00 AM normal vacuum stuff pricing, right? 13-Dec-18 10:02 AM True, but I barely know how to use my lathe and mill and I'm pretty sure I could make these. 13-Dec-18 10:03 AM it's like with pricey test/measurement equipment - on the inside only cheap electronics parts 13-Dec-18 10:03 AM yeah, if you now how to weld too, you could make them yourself, that's right 13-Dec-18 10:03 AM but if you want to build and sell them for cheap, you need a full automated process 13-Dec-18 10:03 AM (and enough customers to make sense of it) 13-Dec-18 10:03 AM question is, what you're willing to do - build it from scratch in 4 hours or so 13-Dec-18 10:03 AM and if it doesn't seal right, rework or build another one? 13-Dec-18 10:03 AM or pay a price and if it's crap make a phone call and get a new one within 24h 13-Dec-18 10:03 AM and yeah, i gues it's possible to make a good business around UHV parts, if you've (the money for) the tools, the people and the knowledge 13-Dec-18 10:12 AM For manufacturing it yourself at home, you may be greatly underestimating the entire process. The flange part is easy. The difficulty lies in machining the knife edge seal to tolerance, as well as bonding the metal and ceramic. Requires some rather specialized metallization, brazing, and tolerancing to get it to UHV standards 13-Dec-18 10:14 AM yea, but it's not that hard, he is right imho 13-Dec-18 10:14 AM but even if you're know what you're doing, you need time to get the job done 13-Dec-18 10:14 AM what i mean, the geometry is straight forward and brazing with kovar is well documented 13-Dec-18 10:14 AM but without a fully automated process or people doing that job for you, you need a couple of hours per feedthrough 13-Dec-18 10:14 AM without having warranty 13-Dec-18 10:33 AM Easy with experience, but I wouldn't say it's something that could be done at home super easy to industry standard levels. Well documented also doesn't mean easy necessarily, otherwise lots more hobbyists would be doing it. Not saying it is impossible, but not a process you learn over night. Reading and doing are still very different. Getting it bonded does not also garauntee UHV leak-free. I would still say if you want to try, definitely go for it. Doesn't hurt to try, and getting a process down that other makers could replicate that works well enough is always a big plus. Also, most people are not going for or able to hit UHV at home (like past 10^-8 torr), so less than perfect solutions could work fine for most cases. I don't want to discourage anyone from trying, I actually would greatly encourage and support an effort for this type of work, but it won't be an easy road. But if it was easy it wouldn't be fun! I do think this stuff could be done way cheaper than what it is sold for now, we just need more makers tackling the problem and innovating on standard processes. There is similar precedent in the hobby realm for stuff like this with the DIY vacuum tube group. Very small group, but still do able stuff. 13-Dec-18 11:01 AM CF would be harder, sure, but not KF. Seems to (uneducated) me that the actual wire/contacts feed through would be the hardest part, dealing with any tiny leaks or off gassing around those parts, etc. 13-Dec-18 11:03 AM Oh yeah kf would definitely be easier. That can be easily machined at home for sure. You don't even need to make it all yourself - just buy kf or CF blanks for cheap and drill them out yourself as needed. 13-Dec-18 11:03 AM The feedthrough and contact part would be tricky for UHV, but for HV you can get away with high vacuum epoxies and/or o-rings 13-Dec-18 11:03 AM Up to 10^-6 torr, DIY feedthroughs are cheap and relatively easy to manage, and would be plenty vacuum tight for most high vacuum stuff. 13-Dec-18 11:12 AM How deep do standard "waterproof" cable glands work? 13-Dec-18 11:14 AM Deep as in vacuum or deep as in water depth? 13-Dec-18 11:15 AM Probably depends more on the type of rubber used, and the cable/wire type now that I think about it, since you'd probably get leakage through the wire itself (under the insulation) 13-Dec-18 11:15 AM vacuum 13-Dec-18 11:15 AM Yeah, it would have to be to the bare metal, gas would leak in between the jacket and wire 13-Dec-18 11:16 AM I plan to use them for my vacuum kiln, but I'm going to 10^-2, maybe 10^-3 torr with that project 13-Dec-18 11:17 AM That level is very easy, I did that with a rubber stopper and pulling a wire through it. Regular hv rubber outside, copper wire, tight through a hole in the stopper. 10^-3 would be no problem to make a feedthrough for 13-Dec-18 11:17 AM at those kinds of pressures outgassing is pretty much not a problem at all 13-Dec-18 11:19 AM Yeah, you are still in transitional flow at that point, and outgassing doesn't really become a factor until you get to maybe 10^-4 13-Dec-18 11:19 AM Yeah, the outgassing of the wood itself will be measured in pounds of water removed, so the real project is dealing with that before it gets to the pump 13-Dec-18 11:19 AM I keep overthinking parts of this because I started the project with plans to use a little HVAC vac pump, but now have some 24cfm pumps to use. 13-Dec-18 11:22 AM just get some dry ice and build a cryotrap 13-Dec-18 11:27 AM Current plan is using an old portable A/C unit since removing the water too fast from hardwoods will cause cracking and splitting. A larger timber will take a week or two at best without an RF heating source. (just using an electric or water heating pad in the chamber to warm the wood) 13-Dec-18 11:27 AM RF heating is planned for further down the road though, which should be fun. 13-Dec-18 11:30 AM rf heating of... wood? 13-Dec-18 11:30 AM Yep, I want to build basically a hobbyist/maker scale version of this http://www.rfkilntech.com/ 13-Dec-18 11:31 AM huh 13-Dec-18 11:31 AM sure, why not, just install a magnetron in there 13-Dec-18 11:33 AM kinda what I was thinking, just do it and see what happens. 13-Dec-18 11:33 AM iterate from there 13-Dec-18 11:36 AM What are you vacuum drying wood for? 13-Dec-18 11:37 AM Me. 13-Dec-18 11:37 AM Just general woodworking uses. 13-Dec-18 11:37 AM Oh nice! What type of woodworking? 13-Dec-18 11:37 AM I've got a sawmill, so this is the natural next step, with a heaping helping of extra overkill added in 13-Dec-18 11:37 AM I do a lot of woodworking myself, though slowed down since I'm investing more in vacuum stuff 13-Dec-18 11:38 AM It'd be really cool to eventually build a small timber frame cabin with timbers dried this way, but that's getting way ahead of myself. 13-Dec-18 11:46 AM tbh, I've not yet gotten into doing any specific "thing" in woodworking. Mostly just projects around the house, bookshelves, tables, etc. Once I have a faster method for drying the wood I cut, then I'll probably expand to more stuff. 13-Dec-18 11:53 AM Sounds more involved than what I have done. I don't cut and dry my own wood, rather buy the stuff I need. Primarily instrument making, so it's not possible for me to harvest the woods I want for a particular project. 13-Dec-18 12:00 PM Buying wood is $$$, so naturally I've instead sunk a few grand into a sawmill and now this vacuum kiln project. Somehow allocating 10x the cost to a hobby project feels cheaper than just buying the wood... 13-Dec-18 12:01 PM Depends on the project. My stuff is relatively small in size, so I can get high end woods super cheap 13-Dec-18 12:02 PM It helps that I have 5-10 acres of woods I can pull logs from too, which is how I got started - a 26" diameter cherry tree fell across my driveway and I couldn't bring myself to cut and split it for firewood 13-Dec-18 12:02 PM Yeah, making small stuff it makes no sense, especially since many small things like instruments sell for waaay more than materials costs 13-Dec-18 12:06 PM Yeah, though I could never do it full time. Really involved, and puts a lot of stress on the joints over time in the hands. Just stuff for myself. 13-Dec-18 12:07 PM I once got a quote for just the frame of a timberframe cabin... it was 6 figures. So being able to buy a semi-load of logs, cut them, dry them, and then cut/mill the joints could save... incredible amounts of money on such a project 13-Dec-18 12:07 PM Definitely, if you can diy then you can save a lot 13-Dec-18 03:17 PM How does brazing, kovar and ceramics work together in the same sentence? 13-Dec-18 03:21 PM @Applied_Ion I had pretty good luck making CF flanges for strange stuff, but I cheated and made them on a cnc lathe 13-Dec-18 03:37 PM can you expand on that? 13-Dec-18 03:37 PM Stupid question. Can I drive the coils for magnetically moving an electron beam, with audio amplifiers connected to the UA341 opamp I have on the output of my CNC dac's? 13-Dec-18 03:46 PM I'm not sure, since all audio amplifiers AC couple their output 13-Dec-18 03:57 PM true...hmmm 13-Dec-18 03:58 PM @sync yeah, a cnc lathe definitely makes it easier. I'm pretty sure that's the standard way they are made 13-Dec-18 03:59 PM I think the reason why they use a 90° corner is because it was easier to use a form tool back in the day 13-Dec-18 03:59 PM but the angle is not entirely important 13-Dec-18 03:59 PM DESY uses a different one 13-Dec-18 04:01 PM @Nixie those three are very common together. Kovar is one of the common metals used for ceramic to metal joints. The ceramic is coated with some intermediate wetting metal, then the ceramic and kovar can be brazed together 13-Dec-18 04:02 PM AH, that was what I was missing 13-Dec-18 04:02 PM thanks ^^ 13-Dec-18 04:03 PM @sync I have a bunch of papers I recently acquired on the differences between the two standards. Conflat sealing engineering is pretty interesting stuff. The angle isn't that big of a difference, but there is a difference between stresses on the edge. I believe the 90 degree developes less stress than the DESY standard, which is at 70-something degrees 13-Dec-18 04:03 PM Not a difference for stainless conflats, but can make a difference for aluminum edges 13-Dec-18 04:03 PM Though the stuff they were exploring were some very atypical custom stuff, not really standard flanges 13-Dec-18 04:06 PM yeah they were looking how to make flanges machined into solid blocks of stuff more reliable 13-Dec-18 04:07 PM Yeah, or flanges that have less activation. Some really crazy non circular profiles too 13-Dec-18 04:10 PM is lost 13-Dec-18 04:10 PM O_o 13-Dec-18 04:10 PM I'll see if I can dig them up and post them 13-Dec-18 04:10 PM why would machined flanges not be reliable? 13-Dec-18 04:11 PM What machined flanges? 13-Dec-18 04:11 PM Like hand machined vs cnc lathe? 13-Dec-18 04:13 PM @sync said something about making flanges machined into solid blocks, more reliable 13-Dec-18 04:13 PM yeah like machining a CF flange into a plate 13-Dec-18 04:13 PM only that they had huge chunks of stainless 13-Dec-18 04:14 PM Oh, idk the stuff I saw was for weird custom profiles 13-Dec-18 04:14 PM heres some of the reference papers: 13-Dec-18 04:14 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Development_and_Test_of_a_Rectangular_CERN-41B16.pdf 13-Dec-18 04:14 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Development_of_Aluminium_Vacuum_Components-5AE82.pdf 13-Dec-18 04:14 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/The_Influence_of_Material_Properties_to_Mi-FE668.pdf 13-Dec-18 04:14 PM The third one gets into the stress analysis study more 13-Dec-18 04:20 PM ROFL 13-Dec-18 04:20 PM https://www.sciencedirect.com/science/article/pii/S0042207X15300440 13-Dec-18 04:20 PM I was just reading the same paper on the CERN rectangular conflat, but from somewhere else. 13-Dec-18 04:20 PM time to go to sleep 13-Dec-18 04:20 PM gnait everyone! 13-Dec-18 04:23 PM good night! 13-Dec-18 04:23 PM \o/ 13-Dec-18 04:24 PM And good luck with the boys 13-Dec-18 04:31 PM huh, I wonder why they bothered with a .2mm radius in the corner 13-Dec-18 04:31 PM I don't think it would have any influence 13-Dec-18 10:26 PM Maybe it is more resistant to damage than a sharp edge. 13-Dec-18 11:11 PM AFAIK now one knows exactly y DESY uses a different angle 13-Dec-18 11:11 PM and research they (DESY) made on this topic implies: 90deg is better 13-Dec-18 11:11 PM maybe a little trick to avoid offers from suppliers they don't like? 13-Dec-18 11:11 PM or to get funding for more own machine tools? 14-Dec-18 12:43 AM The more cnc, the better. 14-Dec-18 12:44 AM yawn Good morning! 14-Dec-18 12:51 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181214_094950-876AA.jpg 14-Dec-18 12:51 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181214_095037-B8173.jpg 14-Dec-18 12:51 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181214_094936-36B40.jpg 14-Dec-18 12:52 AM uhhh, shiny 14-Dec-18 12:52 AM do you know what those chips are? 14-Dec-18 12:59 AM @Nixie yeah machiiiines \o/ 14-Dec-18 12:59 AM good morning \o/ 14-Dec-18 01:08 AM Moin! 14-Dec-18 03:05 AM Morning! 14-Dec-18 03:05 AM Nope, they seem to be an amalgam of design tests 14-Dec-18 09:30 AM @Applied_Ion question about CRT/VIDICON beam optics. does the thickness of the metal pieces matter? or can I alter the outside shapes, as long as they mantain the inside profiles and relative sizes. 14-Dec-18 10:20 AM The thickness and general geometry will have an effect, though how much of an effect is hard to say without doing modeling. What exactly are you looking to modify, and for what purpose? 14-Dec-18 10:28 AM It actually would be relatively simple to look at the field changes from the original to modified using something like Poisson Superfish. It won't give you particle trajectories, but will give a good indication how much change could be expected. 14-Dec-18 11:18 AM Just thinking that, if the vidicon tube thing works, at some point we will run out of vidicon tubes to dismantle for parts, so I was wondering if it would be possible to machine the stainless parts. (Would be thicker, obviously) 14-Dec-18 11:33 AM Yeah you could certainly do that, I don't think there would be too big of an issue. Again you can always check the fields if you are unsure. Do you have pictures for reference of the parts you are looking to do? 14-Dec-18 12:27 PM Not yet, it is a future idea once, IF, the whole vidicon tube thing works. 15-Dec-18 07:41 AM Joined the server. 15-Dec-18 07:42 AM Welcome! 15-Dec-18 07:43 AM Hey ho 15-Dec-18 10:31 AM Joined the server. 15-Dec-18 10:35 AM Hi! 15-Dec-18 11:23 AM 'allo' allo! 15-Dec-18 11:23 AM Well, looks like the little UVC lamp is working at eradicating the fruit flies 15-Dec-18 11:24 AM nom, ozone 15-Dec-18 11:26 AM Smells pretty different from high voltage corona ozone. Maybe it's a much lower concentration 15-Dec-18 11:26 AM high voltage might have some NOX mixed with it 15-Dec-18 11:26 AM I really need to enable discord notifications 15-Dec-18 11:26 AM the spice is all about the blend 15-Dec-18 11:26 AM Hmm all is nice with spice 15-Dec-18 12:42 PM THE SPICE MUST FLOW! /rides his worm into the sunset/ 15-Dec-18 12:45 PM *leaving behind a trail of smo-... ozone 16-Dec-18 06:37 AM @Nixie you twittered a video sputtering with a leaf green plasma, how the hell is it that much green?! 16-Dec-18 09:00 AM To be frank, I absolutely don't k ow what happened. Might be some contamination from when I powermelted the target. 16-Dec-18 09:00 AM Never happened before. 16-Dec-18 10:35 AM Hehe 16-Dec-18 01:59 PM So just letting you all know I just bought vacuumhackers.com 16-Dec-18 02:02 PM which leads directly into this discord 16-Dec-18 02:02 PM great! 16-Dec-18 02:02 PM yup 16-Dec-18 02:02 PM At some point we need to setup a wiki like teh was talking about 16-Dec-18 02:03 PM sure would be great 16-Dec-18 02:25 PM Oh sure! 16-Dec-18 02:25 PM do we contribute with something? 16-Dec-18 02:25 PM (moneywise) 16-Dec-18 02:27 PM neato ^.^ 16-Dec-18 04:10 PM @AdamMcCombs if you need any site hosting at any point hmu. My work gives out unlimited free hosting if we need it 17-Dec-18 01:14 AM so this was way more of an undertaking than i meant for it to be, but it was very effective https://twitter.com/hedgeberg/status/1074591332352581632 17-Dec-18 01:14 AM (thats my desktop, its extremely out of date but ill be converting it to a high-power vm host later) 17-Dec-18 01:25 AM i see you @GigaSquirrel 17-Dec-18 01:25 AM huehuehue 17-Dec-18 02:16 AM I love adding wheels to stuff... 17-Dec-18 02:16 AM Cabinets, detolfs, static bike, 50kv xformers, printers... 17-Dec-18 02:17 AM wouldn't that make it a mobile bike? 17-Dec-18 02:36 AM Shhh! 17-Dec-18 02:36 AM It was an excuse to practice welding a frame and to help me be less lazy to use the thing! 17-Dec-18 02:36 AM I have a standing workbench because i'm not productive in chairs 17-Dec-18 02:36 AM So the bike fits at the desk when im procrastinating/coding/editing photos 17-Dec-18 02:52 AM sure, welding is always fun 17-Dec-18 04:55 AM 19" rack? 17-Dec-18 05:13 AM those can be welded, too 17-Dec-18 05:22 AM I need to build an enclosure for my server. I'm wasting 32 cores because its too noisy and the gf hates it. She hates anything with a fan actually... Her pc is so quiet... 17-Dec-18 05:22 AM I like fans, especially 120W ducted fans that shred pencils. They also fly away 17-Dec-18 05:25 AM levitating server 17-Dec-18 05:52 AM Joined the server. 17-Dec-18 05:52 AM herro 17-Dec-18 05:53 AM welcome! 17-Dec-18 05:54 AM Why thank you! 17-Dec-18 05:54 AM It would seem the random noise of the interwebs brought me here 17-Dec-18 05:55 AM the random noise here is actually might contain some information 17-Dec-18 05:55 AM It would seem so 17-Dec-18 05:55 AM maybe even something interesting 17-Dec-18 05:55 AM For sure, it will be interesting 17-Dec-18 05:55 AM I was hoping that someone would be able to help me with the gun and deflection parts of an electron microscope 17-Dec-18 05:55 AM ie, design these parts from scratch 17-Dec-18 05:55 AM I was hoping someone would have some examples or pictures 17-Dec-18 05:56 AM I guess @Applied_Ion and @AdamMcCombs are the right people to ask 17-Dec-18 05:57 AM cool, thanks GB 17-Dec-18 05:58 AM applied ion builds guns for accelerators and Adam works on SEM / TEM, they both got a lot of experience 17-Dec-18 05:58 AM cool 17-Dec-18 05:58 AM Can't wait to talk to them 17-Dec-18 05:58 AM you'll have to 17-Dec-18 06:00 AM First time using discord. It's like IRC that wants a gig of ram haha 17-Dec-18 06:00 AM 186.3 MB to be exact 17-Dec-18 06:01 AM that's a very small gigabyte 17-Dec-18 06:01 AM zram 17-Dec-18 06:01 AM lol 17-Dec-18 06:01 AM I believe there's IRC bridges, right? 17-Dec-18 06:02 AM no Idea 17-Dec-18 06:02 AM It's not a proper form of communication unless i can use it on a VT220 17-Dec-18 06:02 AM thb I know f-all about PCs and software 17-Dec-18 06:03 AM That's good. That means you must lead a trouble free and content life 17-Dec-18 06:03 AM yep 17-Dec-18 06:03 AM I looked into it and decided against it 17-Dec-18 06:03 AM Computers are finicky things 17-Dec-18 06:04 AM I can't scope-probe software, that's the issue 17-Dec-18 06:04 AM Maybe if you have nano probes 17-Dec-18 06:04 AM and very very steady hands 17-Dec-18 06:04 AM I can't 17-Dec-18 06:04 AM Some things are better left unknown 17-Dec-18 06:04 AM I'm not saying it's impossible ^^ 17-Dec-18 06:05 AM All you'll find is just layers and layers of abstraction 17-Dec-18 06:05 AM uargh 17-Dec-18 06:06 AM So i was going to ask if you're active in some open source project, but it would seem that you've definitively answered that question 17-Dec-18 06:07 AM so far I've not been part of any bigger project ^^ 17-Dec-18 06:07 AM just building at home whatever I feel like 17-Dec-18 06:07 AM cool 17-Dec-18 06:07 AM Building stuff in my garage too 17-Dec-18 06:07 AM and trying not to get raidation poisioning while doing so xD 17-Dec-18 06:07 AM i mean someone else's garage (bonus, i don't have to clean up) 17-Dec-18 06:07 AM uhhh 17-Dec-18 06:07 AM jackpot 17-Dec-18 06:08 AM exactly 17-Dec-18 06:08 AM radiation poisoning? Sounds interesting haha 17-Dec-18 06:09 AM Hi p13! 17-Dec-18 06:09 AM yeah, mostly building rad detectors 17-Dec-18 06:09 AM Hello! 17-Dec-18 06:09 AM cool 17-Dec-18 06:09 AM Glad i found this channel 17-Dec-18 06:09 AM Seems like a cool place 17-Dec-18 06:09 AM Right off the bat, the first guy i meet here is like yeah i'm working with radiation in my spare time ... no biggie lol 17-Dec-18 06:12 AM it's a low pressure environment 17-Dec-18 06:12 AM har har 17-Dec-18 06:28 AM I'd say I'm one of the least 'crazy' people here... 17-Dec-18 06:28 AM The voice of reason huh? 17-Dec-18 06:28 AM haha, not at all 17-Dec-18 06:29 AM Only slightly damaged DNA? haha 17-Dec-18 06:31 AM A bit of Evolution has never hurt anyone 17-Dec-18 06:31 AM It's not like in the comics, just FYI. You don't get superpowers 17-Dec-18 06:32 AM Welcome @p13 I see you are interested in electron beam optics for a scanning electron microscope? Are you looking to build this unit completely from scratch? I won't be able to talk details for a few hours until my lunch break, got an important run I'm prepping at the lab this week, but I can definitely provide some help. Just a bit of background, I work as an EE for an electron linac facility, as well as am personally building the highest peak power and energy accelerator ever built by any amateur effort, fully open source. I primarily focus on high intensity gun design in terms of electron guns, but I can provide assistance for lower power stuff. 17-Dec-18 06:34 AM @Applied_Ion We should talk!!!! 17-Dec-18 06:34 AM We are building this completely from scratch to be a low cost solution. 17-Dec-18 06:35 AM I might not get Comic book Superpowers, but I think having studied physics is pretty damn close 17-Dec-18 06:36 AM @GigaSquirrel You would think so haha 17-Dec-18 06:39 AM @p1very cool! My accelerator is also aimed to be very low cost (relatively speaking) for high power beam physics in the maker community. In terms of details for everything needed for a SEM, @AdamMcCombs can provide lots more details since this is his area of expertise, but I can help with looking at optics design. There are some free resources available to simulate fields, but actual particle trajectories requires some more expensive software 17-Dec-18 06:40 AM cool, well, when you have some time to spare, i'd love to talk to you @Applied_Ion 17-Dec-18 06:40 AM Sorry if I don't respond in a while, will be working in the shielded target room, zero signal in there lol. No problem, look forward to hearing more about this project! 17-Dec-18 06:41 AM lol no signal in a shielded room ... you don't say 17-Dec-18 06:59 AM Just be sure to not infringe on Hitachi's electron gun patent... xD 17-Dec-18 07:10 AM would also be interested @Applied_Ion @p13 17-Dec-18 07:12 AM @Koelzer cool 17-Dec-18 07:12 AM Just concept phase now 17-Dec-18 08:05 AM Anyone know what this flange is? 17-Dec-18 08:05 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181217_155606_1-88989.jpg 17-Dec-18 08:05 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181217_155623-71B49.jpg 17-Dec-18 08:05 AM I've never seen it before 17-Dec-18 08:12 AM Nope. 17-Dec-18 08:28 AM gah 17-Dec-18 10:09 AM @p13 Hey there. What type of SEM are you looking to build? Electro static or magnetic? I have photos of what various different scan and alingnment coils look like if you are interested 17-Dec-18 10:25 AM I wouldn't mind looking at the photos, I always wondered what they looked like inside. 17-Dec-18 10:27 AM For those of you here interested in SEM stuff, there is a free monte carlo simulation software called CASINO. This allows you to simulate beams and target interactions. 2 versions of this: 2.51, and 3.3. The latter is more involved, but allows you to simulate and predict SEM images and signals based on beam and target parameters. It also has the ability to simulate signals from x rays and back scattered electrons. Beam energies from 0.1 to 30keV are supported 17-Dec-18 10:27 AM http://www.gel.usherbrooke.ca/casino/index.html 17-Dec-18 10:28 AM How important is the surface finish of the electrodes, do you normally polish them? 17-Dec-18 10:30 AM Posted in the resources section for future reference as well 17-Dec-18 10:36 AM hmm, interesting, seems to be quite powerful. 17-Dec-18 10:37 AM @RDX are you working with @p13 on this? 17-Dec-18 10:37 AM do you know why the simulation is limited to 30kV? 17-Dec-18 10:46 AM We're working on different parts, I think he just wants to see how the sections of an SEM are arranged. 17-Dec-18 10:46 AM what materials are used, etc 17-Dec-18 10:52 AM Plain steel is common for column to cut down magnetic field interference 17-Dec-18 11:02 AM Well if you want photos of electron optics... 17-Dec-18 11:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180911_143556-A874C.jpg 17-Dec-18 11:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180729_193040-902CA.jpg 17-Dec-18 11:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180911_150017-15B4B.jpg 17-Dec-18 11:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180911_143601-94ED4.jpg 17-Dec-18 11:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180803_161612-10551.jpg 17-Dec-18 11:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180803_161545-E3D83.jpg 17-Dec-18 11:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180803_152754-20C88.jpg 17-Dec-18 11:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180803_140751-A6A90.jpg 17-Dec-18 11:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180731_141529-D5055.jpg 17-Dec-18 11:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180802_030111-ED022.jpg 17-Dec-18 11:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180722_023816-5DABB.jpg 17-Dec-18 11:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180722_024350-D3E8A.jpg 17-Dec-18 11:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180722_024255-C3E75.jpg 17-Dec-18 11:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180604_183341-5EBF4.jpg 17-Dec-18 11:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180723_205811-76DE4.jpg 17-Dec-18 11:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180524_180642-1EC77.jpg 17-Dec-18 11:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180723_205819-CED2E.jpg 17-Dec-18 11:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_-la7uiy-0DB4C.jpg 17-Dec-18 11:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180524_182246-F8400.jpg 17-Dec-18 11:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180729_182826-5F0AE.jpg 17-Dec-18 11:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Copy_of_IMG_20170903_232626-2F013.jpg 17-Dec-18 11:09 AM Do they use a type of plastic as an insulating material? 17-Dec-18 11:20 AM So what is the scope of this sem? Personal project, product development, open source, etc? 17-Dec-18 11:21 AM ideally an open source project at some point 17-Dec-18 11:21 AM Hardware isn't like software, we aren't offered the same protections as copyright, so we'll have to see how we can do it 17-Dec-18 11:24 AM What is your background? Do you have experience with sem, electron beam systems, high vacuum, etc? 17-Dec-18 11:30 AM I have a bit of experience with electron beam systems, but it definitely isn't my background, it's more of a hobby if anything. 17-Dec-18 11:33 AM What level of performance are you looking to achieve? Proof of concept, or more along the lines of commercial sem? Sorry for the million questions, just gauging the project at an upper level 17-Dec-18 11:36 AM SEM is probably overkill, more interested in how it's structured, and what materials are safe to use in a UHV 17-Dec-18 11:36 AM like if it uses plastic or glass/ceramics, and if plastic, what type of plastic is used 17-Dec-18 11:36 AM based on the pictures, you can tell value engineers haven't reduced the quality of the tech, so there's that too 17-Dec-18 11:36 AM and to see if they implement ion traps 17-Dec-18 11:45 AM I would strongly recommend reading on basic UHV technology, electron beam systems, sem, etc - really anything remotely related to the topic and material in that case. There are an incredible amount of resources available for little to no cost. Even old textbooks which I highly recommend. If it is a proof of concept design, your requirements are much more relaxed. I'd still recommend really diving into literature and technology on it as much as possible. Papers, books, etc. Absorb as much as you can. The more you prep ahead of time, the more you will know going in and have greater likelihood to succeed. For example, I spent a year on just the vacuum design and engineering of my system alone, gathering a huge library of resources. I only just started the official accelerator design now, after hundreds of hours of research, and even now am doing a full literature and tech review which will take probably another year or more of work. This is all hobby stuff on my free time as well, using freely available resources too. 17-Dec-18 11:45 AM I would say it's definitely reasonable to accomplish, but it will take a lot of work 17-Dec-18 11:46 AM So i can't just load SEM.stl and hit print on my cheap chinese 3D printer? 17-Dec-18 11:46 AM bummer 17-Dec-18 11:46 AM greetings @Applied_Ion 17-Dec-18 11:50 AM Hello @p13, sounds like this could be a quite involved project depending on how far you want to take it 17-Dec-18 11:50 AM It is a journey 17-Dec-18 11:50 AM We want to learn as well as do cool things 17-Dec-18 11:50 AM And share with the world 17-Dec-18 11:53 AM If you stick with it, you will learn a tremendous amount. Staying with it for the long haul is grueling, but worth it if you love doing it 17-Dec-18 11:53 AM I want to use it to finally see my bank account balance 17-Dec-18 11:53 AM so far i haven't been able to detect it 17-Dec-18 11:53 AM ok that was funnier in my head 17-Dec-18 11:56 AM Does the column have a coil/coils around the entire section? 17-Dec-18 11:57 AM With high vacuum stuff, there isn't much bank account left, even with the wonders of ebay it adds up fast 17-Dec-18 11:57 AM I just see a bunch of cylindrical electrodes 17-Dec-18 11:58 AM No you have pole pieces at certain places and place the optics where you need to to get the desired field 17-Dec-18 11:59 AM have to do it like they did it before mechanical vacuum pumps, with a mercury pump xD 17-Dec-18 12:13 PM There's a picture with a very reflective aperture, were would that be located? I'm guessing the cathode is in there. 17-Dec-18 12:42 PM Can you be more specific? 17-Dec-18 12:52 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180911_150017-06044.jpg 17-Dec-18 12:52 PM That's called a whenalt and it's part of the Electron Gun 17-Dec-18 12:52 PM The filament is inside of it 17-Dec-18 12:52 PM This is an example if an anode chamber and plate 17-Dec-18 12:52 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_fcu5qu-A354E.jpg 17-Dec-18 12:52 PM There's a lot of different styles that work 17-Dec-18 12:56 PM do you have any pictures of the electron gun internals? 17-Dec-18 12:56 PM shinu 17-Dec-18 12:56 PM shiny* 17-Dec-18 12:56 PM Under the whenalt? Yeah 17-Dec-18 12:59 PM ah, the wehnelt cylinder/control grid? 17-Dec-18 12:59 PM Control grid? 17-Dec-18 01:00 PM I would really suggest going through the literature. Download as many pdfs and examples as you can, get old textbooks on electron optics and sem, and familiarize yourself with the technology. There is a ton of info you can find, and very readily reverse engineer from. But you should have strong fundamentals in the tech before attempting to build it yourself. The technology is pretty consistent in the field and industry 17-Dec-18 01:00 PM a bias is typically applied to increase/decrease the beam current, it's a vacuum tube term 17-Dec-18 01:01 PM Ok yeah just different terminology in sem 17-Dec-18 01:01 PM it's also used for focusing 17-Dec-18 01:01 PM Not in sem 17-Dec-18 01:02 PM isn't the primary 17-Dec-18 01:02 PM Collimating yes, but there's other stuff for focusing and beam current 17-Dec-18 01:02 PM It's not something that has a major effect on bringing the beam down to a point 17-Dec-18 01:03 PM Control grid is seen in certain electron guns like in thermionic emission triode guns for accelerators as terminology 17-Dec-18 01:04 PM Yeah in sem tem we don't deal with stuff that fancy or high of current 17-Dec-18 01:04 PM Most of the time 17-Dec-18 01:04 PM What's the max beam current you would typically see in normal operation? 17-Dec-18 01:04 PM That a hard question to answer 17-Dec-18 01:04 PM Anywhere from -7 amps to -13 17-Dec-18 01:04 PM For Thermionic systems 17-Dec-18 01:05 PM That seems rather high? 17-Dec-18 01:05 PM Doing bright field imaging 17-Dec-18 01:05 PM -7 is usually for x ray micro analysis 17-Dec-18 01:06 PM The power supply should prove to be quite entertaining 17-Dec-18 01:07 PM that's an exponent value, correct? 17-Dec-18 01:08 PM Yup 17-Dec-18 01:08 PM 10x-7 amps? 17-Dec-18 01:08 PM oh right 17-Dec-18 01:08 PM not much then 17-Dec-18 01:08 PM High? That's extremely low, should be very easy to power lol 17-Dec-18 01:08 PM yeah right, makes sense now 17-Dec-18 01:10 PM Joined the server. 17-Dec-18 01:11 PM welcome! 18-Dec-18 12:33 AM Moin 18-Dec-18 01:00 AM 'gday 18-Dec-18 01:08 AM moin! 18-Dec-18 02:00 AM Joined the server. 18-Dec-18 02:04 AM welcome! 18-Dec-18 03:12 AM hey! 18-Dec-18 03:12 AM Welcome! 18-Dec-18 03:25 AM If I'm already here I might actually ask some questions 18-Dec-18 03:25 AM I'm currently trying to get / build a nanofocus xray source and as this is highly related to SEMs there are some things I don't get 18-Dec-18 03:25 AM first, am I right assuming that the focal spot size of the electron beam mainly determines the feature resolution of the microscope? 18-Dec-18 03:30 AM @AdamMcCombs @Applied_Ion , that sounds.like a summoning spell for you. 18-Dec-18 03:34 AM Like, reading literature about nanofocus xray, it seems like reaching focal spot sizes as big as 500nm at 180kv / 10W is already super hard and state of the art. 18-Dec-18 03:34 AM otoh most TEM reach down to single nanometer resolution also at a voltage >100kV and I don't get what's the big differenece 18-Dec-18 03:34 AM I would expect that for TEM the current / power is much lower and that's why its easyer to keep the electron beam together, but I didn't find any information on that 18-Dec-18 04:22 AM Anyone knows where can I get decent purity aluminium sheet to use as a target? 18-Dec-18 04:22 AM (that is not as expensive as a black market kidney, I mean) 18-Dec-18 04:31 AM ebay? 18-Dec-18 04:31 AM I can find Al 99.5 sheets for ~5€ 18-Dec-18 04:33 AM found those too, would it be good enough? 18-Dec-18 04:33 AM I can't find 99,9, for example. 18-Dec-18 04:33 AM I was thinking on even using this: 18-Dec-18 04:33 AM https://www.ebay.com/itm/INGOT-1-TROY-OUNCE-PURE-ALUMINIUM-999-BUFFALO-BAR-1146/323593005795?hash=item4b57a56ae3:g:A4EAAOSwmMNb5uK2:rk:3:pf:0 18-Dec-18 04:33 AM (but I don't know the size, I need it to be at least 4cm wide) 18-Dec-18 04:33 AM Hm...I think it's like 44*75mm. should be good enough! what does .999 purity mean in these ingot things? 18-Dec-18 04:47 AM Like, it's about 10€ and the size is correct. I could machine it down to have a flat surface. 18-Dec-18 04:50 AM @niklas afaik there's no such thing as an xray lens, you can use a zone plate, but the xray band needs to be very narrow for it to work properly 18-Dec-18 04:55 AM Well, just bought the thing. 18-Dec-18 04:55 AM 80mm x 45mm x 4mm 18-Dec-18 04:55 AM This must be the weirdest sputtering target ever. XDDDDDDDD 18-Dec-18 04:55 AM How sacrilegous is to mill it down to a flat surface, btw? 18-Dec-18 05:18 AM @RDX yeah I know you can really focus / deflect xray 18-Dec-18 05:18 AM From what I read online every nano focus x-ray tube is basically build exactly like a TEM, with the target beeing a tungstun coated beryllium window 18-Dec-18 05:18 AM But if I got this correctly I wonder how the specs between a TEM and a nanofpcus xray differ that much 18-Dec-18 05:18 AM for a TEM 1nm focal spot size doesn't seem to be a problem while for xray 500nm is state of the art 18-Dec-18 05:20 AM easier to manipulate charged particles 18-Dec-18 05:20 AM you can't really deflect light without something physically in its path 18-Dec-18 05:21 AM https://slideplayer.com/slide/4428471/14/images/15/Schematic+view+of+a+microfocus+X-ray+tube.jpg 18-Dec-18 05:21 AM huh? I don't talk about focusing x-ray 18-Dec-18 05:21 AM this is how a micro / nanofocus x-ray head work 18-Dec-18 05:21 AM to me, this basically looks exactly like the first stage of a TEM 18-Dec-18 05:23 AM ah, I was thinking about something else, it's probably due the current required 18-Dec-18 05:24 AM but at least you've to focus the x-rays, right? 18-Dec-18 05:24 AM after the transmission target i mean 18-Dec-18 05:24 AM no 18-Dec-18 05:24 AM you can't focus x-ray on a small scale 18-Dec-18 05:25 AM you can a but with CRL 18-Dec-18 05:25 AM https://en.wikipedia.org/wiki/Compound_refractive_lens 18-Dec-18 05:26 AM the idea is to have the x-ray point source as small as possible so for the imaging you can only rely on theorem of intersecting lines 18-Dec-18 05:27 AM yeah ok, but the "source" is not the electron beam 18-Dec-18 05:27 AM in the case of such a microfocus head 18-Dec-18 05:27 AM no, it's the bremsstrahlung emitted by the electrons 18-Dec-18 05:27 AM it's the excited region in the target 18-Dec-18 05:27 AM the focal spot size of the electrons determine how brilliant the x-ray source is 18-Dec-18 05:28 AM and that's much larger than the spotsize 18-Dec-18 05:28 AM dental x-ray tubes habe a spot size of ~1mmx1mm 18-Dec-18 05:28 AM yeah ok 18-Dec-18 05:28 AM Best you can get without magnetic lenses is ~8µm+ 18-Dec-18 05:28 AM but even with a sportsize arround 10nm or so 18-Dec-18 05:28 AM spotsize 18-Dec-18 05:28 AM you've a excited region with a diameter app. 1 micrometer? i dunno 18-Dec-18 05:29 AM ah so you think the actual electron beam spotsize in these head is actually similar to a TEM (<10nm) but still you only get 500nm feature resolution 18-Dec-18 05:29 AM maybe i'm wrong ^^ 18-Dec-18 05:29 AM yeah that would make sense 18-Dec-18 05:29 AM yep exactly 18-Dec-18 05:29 AM that's y they make so huge efforts to build FEL and stuff like that for more resolution 18-Dec-18 05:29 AM for "compact sources" 18-Dec-18 05:34 AM Next question, looking at the slide above / any other crosssection of a TEM: how to you power the filament at a voltage bias of -180kV? 18-Dec-18 05:34 AM Like, in microwave oven magnetrons the filement is also biased with high voltage, but that's "only" 3kV 18-Dec-18 05:34 AM how to you do that with a high voltage cable that is arm-thick? 18-Dec-18 05:43 AM Arm thick? Not needed at all for those low currents and voltages. Our cable that biases our accelerator gun to up to -160kV at mA of current is maybe 1/2" thick total at most 18-Dec-18 05:49 AM https://cdn.caeonline.com/images/ge-phoenix_nanomex-160_843086.jpg 18-Dec-18 05:49 AM okay, small arm 18-Dec-18 05:50 AM One way would be like how we bias our gun. The entire filament supply is biased floating at -160kv on an isolated deck. So the ground of the filament supply is referenced to the high voltage, as opposed to absolute ground. We use a large 175kv isolation transformer that provides 125v 1:1 with that hv isolation to bring power to the filament supply. Between the anode and cathode is a very large insulator. However, this isn't really feasible for the hobbyist since these isolation transformers are very expensive and need to be custom ordered usually 18-Dec-18 05:51 AM so there are in fact two wires in the cable, one with -180000V and one with, say -180010V to ground? 18-Dec-18 05:51 AM I guess I would be able to come up with something, either using a battery, inductive coupling (like QI charging) or something ligth-based (solarcell + floodligth :D) 18-Dec-18 05:57 AM No, just one wire for the hv, which connects to the corona shielded metal deck, making the whole deck float at 160kv creating a virtual ground biased to thst level 18-Dec-18 05:57 AM The isolation transformer brings up 120v through the deck to power the filament 18-Dec-18 05:58 AM ok, so one physical wire with two conductors inside? 18-Dec-18 05:59 AM It's just a multistrand single conductor insulated hv wire. Completely seperate from the isolation transformer. The biased deck literally sits on top of the whole transformer physically 18-Dec-18 05:59 AM We bias a whole deck because we have other supplies that need to sit at that voktage, like grid bias and the pulser 18-Dec-18 06:00 AM okay, but how do you apply the ~10V @ 1A for the filamant? 18-Dec-18 06:00 AM Note this is for an accelerator, not a TEM lol 18-Dec-18 06:00 AM I may have to draw a picture lol 18-Dec-18 06:00 AM It's a rather uncommon connection method 18-Dec-18 06:01 AM ah okay, I would like to know how more common TEM do this 18-Dec-18 06:01 AM For me, there are at least three connections that need to go to the electron source, two for the filament supply + the wehnelt cylinder 18-Dec-18 06:01 AM all biased at -180kV 18-Dec-18 06:02 AM Yeah, sounds exactly like what we do, except we have a bunch more connections that need to be biased 18-Dec-18 06:05 AM okay, and how to you get these three connections out of your vacuum connected to the electronics? 18-Dec-18 06:07 AM Huge custom high vacuum gun interface on a giant insulator lol 18-Dec-18 06:07 AM I'd take pictures if I could, but I don't think I can share it publicly due to some sensitivity of the stuff 18-Dec-18 06:07 AM I'll have to draw it 18-Dec-18 06:11 AM nah no worries, I think I got the idea 18-Dec-18 06:11 AM Halfway done lol 18-Dec-18 06:11 AM main question was if is actually popular to bias the whole filament supply 18-Dec-18 06:11 AM or if there is some weird magic going on with induction or something similar 18-Dec-18 06:11 AM I'm asking because I try to find out weather it is worth / possible to buy a TEM head without electronics, building the supply from scratch 18-Dec-18 06:22 AM In reality the corona shields for the cathode connection and deck overlap to reduce corona losses, but was just spaced out in the diagram for ease of viewing. 18-Dec-18 06:22 AM The connections between the filament, gun, and hv are also oversimplified, and more complex due to the other biases and pulser connections, so it's not quite this way in reality. The important take away is the filament supply is referenced to the hv virtual ground 18-Dec-18 06:22 AM I don't think I actually showed the filament reference correctly 18-Dec-18 06:28 AM okay, thanks 18-Dec-18 06:28 AM Sorry if it's still confising, diagram isn't quite right still, it's been a whole since I reviewed the connections 18-Dec-18 06:28 AM no it's fine, I get the idea 18-Dec-18 06:28 AM so do you think it works the same with the heads from commercial nanofocus heads? 18-Dec-18 06:28 AM like this one: https://www.ebay.de/itm/Phoenix-X-ray-Nano-Focus-XS160T000F-126907-and-Black-Tube-extra/163399412057 18-Dec-18 06:28 AM I was expecting the HV connector on the end was a single conductor, but then probably it's the same as with your accelerator and there are in fact at least three connections inside that isolator 18-Dec-18 06:42 AM Sorry, connections were off. Our filament is dc not ac 18-Dec-18 06:42 AM Need to redraw that diagram, it's not right 18-Dec-18 06:42 AM the insulator may have multiple connections for gun and bias for your stuff, though I'd have to look more closely 18-Dec-18 07:12 AM Our geometry will also be different in the sense that the connections are also configured coaxially as a 50 ohm impedance interface since we run in pulsed mode and need to match connections and load. In that regard the X ray head connections should be much simpler since it's just a dc bias and doesn't need special geometric considerations for pulses. 18-Dec-18 07:15 AM ahhh ok 18-Dec-18 07:17 AM However, the connections for this are typical for many thermionic emission biased guns. Google images "electron gun bias circuit" will give examples. It's all really the same for these types of guns 18-Dec-18 07:17 AM actually, this is extremely similar to how we set up our system: 18-Dec-18 07:17 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Electron_Gun_System_for_NSC_KIPT_LINAC-EF334.pdf 18-Dec-18 07:17 AM actually, for your setup, you may not need a whole biased deck at all 18-Dec-18 07:17 AM our system requires the cathode to be pulsed negative with the anode grounded 18-Dec-18 07:17 AM however, if the TEM gun anode is at +180kv and your cathode is at ground, it makes driving much simpler 18-Dec-18 07:17 AM you would have to check though, it may be that the cathode is negatively biased 18-Dec-18 07:17 AM usually, the anodes are grounded and a negative hv is applied to bias the gun 18-Dec-18 07:17 AM another general overview: 18-Dec-18 07:17 AM https://www.semitracks.com/reference-material/failure-and-yield-analysis/failure-analysis-die-level/scanning-electron-microscope.php 18-Dec-18 07:41 AM TorrSeal is frigging magic 18-Dec-18 07:41 AM Totaly saved my bacon last week ❤ 18-Dec-18 07:50 AM @niklas i'll look through my resources later and see if there are exact/specific circuit diagrams and schematics for the bias supplies, but most thermionic guns are the same in this regard 18-Dec-18 07:52 AM thanks! 18-Dec-18 09:21 AM hmm, I'm really tempted to buy that Phoenix head 18-Dec-18 09:21 AM I could get it for 570€ shipped 18-Dec-18 09:21 AM If I knew I'm able to get it running again I would totally buy it... 18-Dec-18 09:21 AM I have all the vacuum equipment and maschines for custom parts... What I'm missing is the high voltage source and documentation about the inner construction of the head 18-Dec-18 09:21 AM It has this weird high voltage connector at the top, plus a 11 pin low voltage connector, probably for the two focusing coils 18-Dec-18 09:21 AM Is there any chance to reverse engineer such a thing, without knowing anything about the optics? Just by using a multimeter to get the pinout and a lab bench power supply? @AdamMcCombs 18-Dec-18 10:45 AM awaits to see a positive answer 18-Dec-18 10:54 AM You can use a multimeter for the filament. 18-Dec-18 10:54 AM The cathode would probably be easier to locate by sight since that is where the hv feeds into 18-Dec-18 10:54 AM Not sure about other optics though 18-Dec-18 10:54 AM Of course you could always xray it lol 18-Dec-18 10:54 AM If my system was running I'd offer to xray it for you 18-Dec-18 01:14 PM I have a working xray setup 18-Dec-18 01:14 PM but as this is made of 10mm thick steel I would not expect to see anything with 120keV 18-Dec-18 01:25 PM Yeah definitely not with 120kev. This is not an xray tube though lol. It will take a lot of optimizing, but I could potentially achieve quite a bit higher than that at max output. Though initial testing will be much lower voltages for safety 18-Dec-18 01:25 PM Though optimizing for xray energy will be an easier mode to operate in than my major goal modes 18-Dec-18 01:32 PM I should look into x-ray focusing but safety first; i need more shielding! 18-Dec-18 01:59 PM So on a tem gun you use a multi stage ac isolation transformer to get the filament current up to the gun 18-Dec-18 02:01 PM So still similar principle to accelerator guns. The key is an isolation transformer 18-Dec-18 02:01 PM Yeah 18-Dec-18 02:01 PM That's tough. In theory you could do it yourself 18-Dec-18 02:02 PM The tanks are split into 2 sides, on is the transformer and the other is the cw 18-Dec-18 02:02 PM The hard part about using an existing gun is going to be the cable 18-Dec-18 02:03 PM Our transformer is a large single stage one completely epoxy encapsulated made by Stangenes 18-Dec-18 02:03 PM How many kV? 18-Dec-18 02:04 PM Our new one is maybe 170kv isolation 18-Dec-18 02:04 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180821_133053-54476.jpg 18-Dec-18 02:04 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180821_133151-C9F5C.jpg 18-Dec-18 02:04 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180821_132959-3F30B.jpg 18-Dec-18 02:04 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180821_132346-3D36E.jpg 18-Dec-18 02:05 PM Yeah, much more compact and elegant. Doesn't look as cool as yours though 18-Dec-18 02:05 PM The bias resistor is a physical pot driven by a motor and an insulating shaft 18-Dec-18 02:05 PM This thing is easy to service though 18-Dec-18 02:05 PM And cheap 18-Dec-18 02:07 PM Yeah there is no servicing ours. It has to work, if it fails you send it back. Not cheap, either, Stangenes is one of the big transformer suppliers for accelerator related stuff. Mostly pulse transformer stuff as well 18-Dec-18 02:07 PM They rarely fail though, so we rarely need servicing on them 18-Dec-18 02:07 PM All this work and cost for a lousy filament supply lol. 18-Dec-18 02:10 PM Is there any exoctic requirements? 18-Dec-18 02:10 PM @niklas what exactly do you want to reverse engineer? 18-Dec-18 02:16 PM For these transformers, no exotic requirements. Just isolation and compact form factor 18-Dec-18 02:16 PM I mean for the gun 18-Dec-18 02:20 PM Not really, mostly a typical thermionic gun. Though the new one is a bit more of a challenge. Up to 160kev operation with 20 amps out up to 1khz. Minimal grid intercept. We also run a bit odd gun topology in a grounded grid configuration. Allows us to bias the gun at hv with one supply, and pulse with low voltage high current to get the current requirements with another supply 18-Dec-18 02:20 PM Also ranges from ns to us pulse widths, so wide operational mode as well 18-Dec-18 02:33 PM Also allows us to operate gun as a constant current source in grounded grid mode 18-Dec-18 07:44 PM Joined the server. 18-Dec-18 07:44 PM Hi everyone, I stumbled upon this server while looking for resources on SEM troubleshooting. I'm new to electron microscopy but I recently acquired a JEOL JCM-5000 Neoscope at an auction for a price I couldn't refuse. 18-Dec-18 09:52 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_1264-37393.JPG 18-Dec-18 09:52 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_1265-6B807.JPG 18-Dec-18 09:52 PM I'm just a hobbyist so it's in my basement at home. The software is telling me the sample chamber isn't reaching high vacuum, although its says the column is reaching high vacuum. I don't even understand how that's possible, since they're both connected to the same turbo molecular pump. Obviously I have some things to learn... 18-Dec-18 10:08 PM Welcome! 18-Dec-18 10:08 PM You'll find answers here, probably. (Remember people here are from every part of the globe, so it might take a bit for them to wake up and answer, just be patient) 18-Dec-18 10:12 PM Thanks Nixie. Looking through some of the message history on the server, it seems like these are my kind of people. 18-Dec-18 10:30 PM Glad to hear that! Also, don't be afraid to mention names to make sure you get their attention. @AdamMcCombs 18-Dec-18 10:30 PM He is the go to person for scopes. 18-Dec-18 10:32 PM I found this server while looking through his twitter. I think he's local to me too, so maybe I can pick his brain. 18-Dec-18 10:52 PM Very nice. Definitely a more compact package than my JEOLs. Where are you at? 18-Dec-18 10:52 PM First thing to check is the oring on the door 18-Dec-18 10:52 PM Common leak 18-Dec-18 10:56 PM I'm in the Seattle area (Renton) 18-Dec-18 10:56 PM O-ring on the door looks perfect and I've cleaned it a few times. I'm using IPA and kimwipes to clean. I've checked the backing pump with a Pirani gauge and the ultimate vacuum is exactly per specifications. 18-Dec-18 10:58 PM Oh nice. You should come to the hardware Meetup sometime 18-Dec-18 10:58 PM Hm 18-Dec-18 10:58 PM Is it valving over to the tmp then? 18-Dec-18 10:59 PM I went to a hardware meet up that was based on the Eastside back in 2013-2014... That resulted in me going to China for a startup. 18-Dec-18 10:59 PM Lol 18-Dec-18 10:59 PM This is a new one 18-Dec-18 10:59 PM It's 3h 18-Dec-18 10:59 PM As in hardware happy hour 18-Dec-18 11:01 PM Yeah I'm pretty sure it's switching to the tmp, but I'll have to fire it up and double check. I know the tmp is spinning up because it makes cool jet engine noises. All of the valves passed a self-test diagnostic in the software... 18-Dec-18 11:01 PM I've been meaning to check out the hhh. I worry sometimes that it'll just be tech bros with arduinos. 18-Dec-18 11:03 PM There are indeed tech Bros with arduinos 18-Dec-18 11:03 PM But there's also a lot more 18-Dec-18 11:03 PM I have always had a good time 18-Dec-18 11:04 PM I'll try to make it to the next one! 18-Dec-18 11:04 PM I'm not sure if I will be there but I always try to be 18-Dec-18 11:04 PM Can you send me a photo of vacuum schematics? 18-Dec-18 11:07 PM Adam, do you have any quick tips for checking vacuum leaks? I've tried applying isopropanol to joints and checking for changes in the pirani gauge, but no luck so far. 18-Dec-18 11:07 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-EE5D4.png 18-Dec-18 11:07 PM It's probably pretty simple compared to a normal sized machine. 18-Dec-18 11:08 PM Is there a column isolation valve? 18-Dec-18 11:09 PM Hm, I'm not sure 18-Dec-18 11:11 PM Can you access what it thinks vacuum is? 18-Dec-18 11:11 PM Also can you do a leak rate check? 18-Dec-18 11:13 PM unfortunately the software only gives a "high vacuum", "low vacuum", or "vacuum leak" reading on the pirani gauge. I have my own gauge attached to the backing pump but I'm not sure how useful that location is.... 18-Dec-18 11:13 PM Hm 18-Dec-18 11:13 PM You need service mode 18-Dec-18 11:13 PM Which i don't have for a 5000 18-Dec-18 11:14 PM I bought it because I don't have space for a big machine, but the downside is that it seems to be designed as a black box/walled garden kind of machine. 18-Dec-18 11:15 PM You got that right 18-Dec-18 11:16 PM Maybe I can pester the JEOL service guy. I had to nag him for two weeks just to get the software. 18-Dec-18 11:16 PM Who are you asking? 18-Dec-18 11:17 PM Todd something 18-Dec-18 11:17 PM Todd Carey 18-Dec-18 11:19 PM I don't think he normally does neoscope 18-Dec-18 11:21 PM Ah, ok. Maybe he can point me towards someone. I've been apprehensive to ask about troubleshooting since I'm just an individual guy and I don't have an unlimited budget to fix problems. 18-Dec-18 11:22 PM Eh 18-Dec-18 11:22 PM JEOL sold the scope knowing they would have to support it 18-Dec-18 11:22 PM Albeit at a different level than one of the big scopes 18-Dec-18 11:24 PM It's kind of tricky to dig in to it and poke around. It's pretty cramped! 18-Dec-18 11:25 PM The big ones feel cramped to 18-Dec-18 11:25 PM I suppose I should ask JEOL for some hints before I end up with 200 SEM parts on my bench and no idea how to put them back together. 18-Dec-18 11:25 PM So down and dirty leak check 18-Dec-18 11:25 PM Pump the scope down, leave for a few hours, then see if the pump sounds like it's pumping air when it valves to the specimen chamber 18-Dec-18 11:25 PM Then do that overnight 18-Dec-18 11:25 PM When I say leave I mean turn off 18-Dec-18 11:30 PM Okay, I'll have to think about how to do that. I don't think it will try to pump down the chamber from a cold start unless I open the specimen door first. I could probably just trigger the door switch or something. 18-Dec-18 11:30 PM Thanks for the help Adam. I'll play around with it a bit and see if I can learn something. 18-Dec-18 11:38 PM Yeah no problem. I usually work on scopes I have schematics for, but I wish I could be more help for this one. 18-Dec-18 11:40 PM Well if you ever feel the urge to play with a Neoscope, just let me know. 19-Dec-18 01:48 AM aw, nice scope 19-Dec-18 01:48 AM what was the price? :3 19-Dec-18 01:55 AM my winning bid was $5k USD 19-Dec-18 02:02 AM ah ok, that's fair 19-Dec-18 02:02 AM (i mean that's a real good price i guess) 19-Dec-18 02:02 AM lol, only 50kg? 19-Dec-18 02:05 AM a bit heavier, I think around 70kg 19-Dec-18 02:05 AM It's small though, barely takes up any room on a bench 19-Dec-18 02:09 AM yeah, could be build in a car 19-Dec-18 02:59 AM Question: 19-Dec-18 03:00 AM Answer: 19-Dec-18 03:00 AM writing, dammit! 19-Dec-18 03:00 AM My rotary vane roughing pump is driven with an inverter. are there any drawbacks in reducing the rpm's so I can mantain a certain pressure level, as to not kill the plasma? 19-Dec-18 03:03 AM if the pump is oilfree, it should be no prob, i guess 19-Dec-18 03:03 AM if it still sucks away the flow of your tmp 19-Dec-18 03:05 AM no TMP in there, just the roughing one. 19-Dec-18 03:05 AM and is oil-full. 19-Dec-18 03:05 AM XDDD 19-Dec-18 03:05 AM and for drawbacks, I mean, if I can damage the pump. 19-Dec-18 03:06 AM well, if you reduce the rpms too far it might lead to bad lubrication, but that depends on the pump. 19-Dec-18 03:06 AM yep 19-Dec-18 03:06 AM Noted. 19-Dec-18 03:06 AM of those i had apart, one had an oil pump fixed to the shaft -> the oil flow to the bearing surfaces will decrease with decreasing rpm 19-Dec-18 03:07 AM Mine has sort of an inlet in the end of the pump. 19-Dec-18 03:07 AM that opens slightly every revolution. 19-Dec-18 03:07 AM but that's it. 19-Dec-18 03:07 AM another one just used its own vacuum to suck oil through tiny passages ... i guess that would be more suitable for low rpm use, as long as it can maintain at least some vacuum 19-Dec-18 03:08 AM yeah, just like that. 19-Dec-18 05:07 AM btw, just found a homemade 110mm diffusion pump. 19-Dec-18 05:07 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/file-6D4E6.png 19-Dec-18 05:07 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/file-BC79B.png 19-Dec-18 05:08 AM awwwww that's cute 19-Dec-18 05:10 AM The idea for a miniature one is just stuck in my head now. 19-Dec-18 05:11 AM how miniature? 19-Dec-18 05:11 AM KF16 as high vacuum port? 19-Dec-18 05:12 AM slightly bigger, about 30mm ID. 19-Dec-18 05:12 AM so KF25 high vacuum side :-D 19-Dec-18 05:12 AM to couple it to a vidicon directly, so it's not that the molecules can go anywhere other than down. 19-Dec-18 05:12 AM a vidicon? a camera tube? 19-Dec-18 05:13 AM yeah, I want to make an e-beam photolitography machine with a vidicon tube. 19-Dec-18 05:13 AM it can achieve a spot 10um in diameter, absolutely good enough for my purposes. 19-Dec-18 05:14 AM oh, nice 19-Dec-18 05:18 AM and miniature turbopumps are just not feasible, nor affordable. btw. 19-Dec-18 05:18 AM waiting for @AdamMcCombs to wake up 19-Dec-18 05:18 AM He will, at some point, don't worry. 19-Dec-18 05:22 AM @Nixie nah, getting a tmp ist really not a problem 19-Dec-18 05:22 AM if you're willing to spend 200€ you can easily get one 19-Dec-18 05:26 AM But they are too big 19-Dec-18 05:26 AM I got mine for £75 19-Dec-18 05:26 AM Just gotta look around 19-Dec-18 05:27 AM besides, getting a tmp in germany is not a problem, elsewhere, is much more problematic. 19-Dec-18 05:27 AM lucky you. 19-Dec-18 05:27 AM Fleabay 19-Dec-18 05:27 AM but that kind of cheap, doesn't happen often. 19-Dec-18 05:27 AM besides, is everyone not really curious about a fist sized DP? 19-Dec-18 05:29 AM DPs suck 19-Dec-18 05:29 AM pun not intended 19-Dec-18 05:30 AM ROFL 19-Dec-18 05:30 AM but can't get really damaged. And with newer oils, they can't even catch fire. 19-Dec-18 05:30 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-E9370.png 19-Dec-18 05:30 AM I would like to use that as a base. 19-Dec-18 05:30 AM waterjacket it. 19-Dec-18 05:30 AM ($19, free shipping) 19-Dec-18 05:34 AM Oh that mini diff pump has been around for a while lol. That's what gave me the idea for mine, similar direction to what you are proposing with the kf criss hardware, except I was looking at kf40 and kf50 stuff 19-Dec-18 05:34 AM Nice! 19-Dec-18 05:34 AM As far as I'm aware, for the small volume I want to work with, should work. (28mm ID, 130mm long) 19-Dec-18 05:34 AM My plan involves making a long plug fo the bottom to put the actual heating element away from the walls, generating the heat in the middle of the assembly. 19-Dec-18 05:45 AM Not quite following 19-Dec-18 05:45 AM Also as a general note, if you have it directly connected to the tube, you will still have oil backstreaming without a baffle 19-Dec-18 05:47 AM Nope, planning to add an elbow (also watercooled, might weld it) then to the roughing pump. 19-Dec-18 05:56 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181219_145558-EABB2.jpg 19-Dec-18 05:56 AM The long bottom-plug ensures that the heat is "only" applied to the oil. 19-Dec-18 05:56 AM (nothing in the drawing is to scale, before anyone says anything) 19-Dec-18 06:05 AM That won't work. It would boil the oil in the extended plug, then it will spray back down to the bottom where it is unheated and stop functioning 19-Dec-18 06:12 AM If I make the tube of the plug thin enough, and have it submerged in enough cooled oil, it should only boil in the top section, wich is enclosed in the chimney. All the colum is going to be watercooled with an external jacket (not drawn) 19-Dec-18 06:12 AM BUT, could still not work, as per your deduction, this is only from the top of my head. 19-Dec-18 06:14 AM Yeah, based on how it is drawn now, it won't work 19-Dec-18 06:14 AM Yeah, literally from the drawing, not at all. 19-Dec-18 06:14 AM Why use kf oring and clamp bottom though? My idea was just braze the cap on the bottom and heat it directly like a normal diff pump 19-Dec-18 06:16 AM Because I don't want to braze, or weld by that matter, anything, if possible. 19-Dec-18 06:17 AM Brazing that part would be very easy though, and solve the issue 19-Dec-18 06:17 AM Yeah, your point is totally valid, but that's why I'm relying in the heat isolation from a long plug. so I don't heat the whole thing and have to cool the f out of it to prevent heat spreading. 19-Dec-18 06:17 AM You need to cool the walls for it to work. The oil has to condense when it hits the wall surface 19-Dec-18 06:18 AM I'm not explaining myself correctly, let me try again. 19-Dec-18 06:18 AM The whole column is watercooled with a jacket. BUT, if I do as you propose and braze the endcap with a heating resistor, it's heat is going to get into the column base and transfer into the oil and up into the assembly. My idea, is to put the resistor way up into the column, with only a thin wall of metal to connect it to the body, and surrounding it with oil (wich is going to be cooled from everywhere, as the whole column is watercooled) that way, the heat is only applied to the oil surrounding the head of the bottom-plug. 19-Dec-18 06:18 AM The chimney goes to the bottom, so the oil vapors can either try to presurize it, or shot out from the top. 19-Dec-18 06:18 AM and condense as normally in the outher walls, as they are watercooled from everywhere. 19-Dec-18 06:22 AM by the way, how hot does the oil get? 19-Dec-18 06:23 AM no idea, 250ºC? 19-Dec-18 06:23 AM (and yes, my design uses a lot more oil than a normal pump) 19-Dec-18 06:23 AM Depends on the oil, average is around 250C 19-Dec-18 06:24 AM nailed it! 19-Dec-18 06:24 AM Higher quality oil uses higher temp usually 19-Dec-18 06:25 AM then you could turn an insulator from PTFE or sonethiung like thatto avoid heat transfer from the bottom plate to the outer walls 19-Dec-18 06:25 AM like an elongated centering ring 19-Dec-18 06:25 AM Ok, I see what you are saying now 19-Dec-18 06:26 AM Not sure I want to introduce any PTFE in there. 19-Dec-18 06:26 AM I don't think you will get up to temp easily though, it may still not work like you expect 19-Dec-18 06:27 AM I think I should be able to dump 100W+ with a cartridge there, but yes, the volume might be too small and just boil everything. 19-Dec-18 06:27 AM It could work, best way is just try and see what happens! 19-Dec-18 06:27 AM Of course! 19-Dec-18 06:27 AM I am highly tempted in ordering pieces, but I totally shouldn't. 19-Dec-18 06:28 AM of you know you should 19-Dec-18 06:28 AM we all want you to do this 19-Dec-18 06:28 AM you know I am jobless. 19-Dec-18 06:29 AM no, i didn't 19-Dec-18 06:29 AM ah, well, I'm jobless right now, searching, but nothing yet. 19-Dec-18 06:29 AM now i do. hmmmm. 19-Dec-18 06:29 AM yeah, well, more time to do experiments! 19-Dec-18 06:29 AM besides, I got the TMP for exactly those experiments. 19-Dec-18 06:29 AM yeah 19-Dec-18 06:29 AM at least I have that. ^^ 19-Dec-18 06:49 AM The whole hardware would be around 50$ 19-Dec-18 07:01 AM I actually considered making kits and selling them. Did cost analysis, supplier from China to reduce cost, etc. Got too busy though lol 19-Dec-18 07:05 AM XDDD 19-Dec-18 07:05 AM I can bet my hat that if china decided to produce small DP's they would be quite cheap. 19-Dec-18 07:14 AM Definitely. Even turbos, prices could really fall. We just need more demand. Gotta convince more people to join this hobby! 19-Dec-18 07:16 AM Would not trust them with turbos 19-Dec-18 07:16 AM (In the sense that a cheap turbo without good quality control, is a timed bomb) 19-Dec-18 07:16 AM a cheap DP can't really kill you. 19-Dec-18 07:17 AM Diff pumps would be lower risk, but I wouldn't dismiss turbos. 19-Dec-18 07:17 AM They don't explode like gas turbines lol. The vanes are already weak, it would shred itself internally if anything 19-Dec-18 07:19 AM for the sake of science, at some point the whole group should sacrifice a TMP with a very high speed camera recording, to actually show what happens 19-Dec-18 07:21 AM That's an expensive test... 19-Dec-18 07:22 AM @meowter_space says it's not. 19-Dec-18 07:25 AM i think at Pfeiffer they did some experiments like that with high-speed-cameras 19-Dec-18 07:25 AM and... well, i could potentially sacrifice a tmp or two for science... 19-Dec-18 07:28 AM You have that many lying around you can just trash like that!? 19-Dec-18 07:28 AM i have some. all in very bad condition, all lacking a controller 19-Dec-18 07:28 AM except for my big leybold, but i certainly wouldn't shred that thing. 19-Dec-18 07:30 AM What are you using your vacuum system for? 19-Dec-18 07:31 AM that's the big problem - no working vacuum system yet. just collecting parts, bits and pieces whenever they are cheap and/or available 19-Dec-18 07:31 AM i think i will finally get a lid for my vacuum chamber, so i can at least do some first tests on that 19-Dec-18 07:32 AM Makes sense. It's a long road for sure. Started a year ago, and only just now will be getting vacuum up in February 19-Dec-18 07:33 AM started... 10 or more years ago 19-Dec-18 07:33 AM Oh wow, you got me beat there! 19-Dec-18 07:34 AM by now i have a pretty big collection of pumps, fittings, flanges, gauges, parts, and stuff 19-Dec-18 07:34 AM I was able to get a bunch of stuff for free though which helps massively 19-Dec-18 07:35 AM yeah, free stuff is the worst... my first rotary vane pump was a gift. "take it, it doesn't turn anymore" 19-Dec-18 07:35 AM and then it escalated and more and more stuff began appearing in my home :-D 19-Dec-18 07:36 AM Free stuff is amazing. 2 diff pumps in practically brand new condition, 6" conflat hardware, 20+ large pulse caps, and a very special item I haven't revealed yet 19-Dec-18 07:36 AM Helps though that I work in the accelerator field. It's still really tough to get the stuff 19-Dec-18 07:37 AM CF is something I have not gotten in useable quantities yet... most of my stuff is KF, then some K or F 19-Dec-18 07:38 AM Most of my cf stuff is ebay purchased, but I got a few key items for free 19-Dec-18 07:38 AM I have 3 chambers I am prepping for experiments, all interchangeable on my pump stand 19-Dec-18 07:39 AM sawed off a CF16 weldflange from a completely deformed chamber a few weeks ago. maybe this is my way into CF stuff XD 19-Dec-18 07:39 AM interchangeable chambers... wow. 19-Dec-18 07:39 AM but i'll have to go now 19-Dec-18 07:39 AM so, read you later ^^ 19-Dec-18 07:40 AM Well, interchangeable in the sense they all fit on my pump adapter. Made it that way so they can be changed rapidly 19-Dec-18 09:03 AM hii 19-Dec-18 09:21 AM hey 19-Dec-18 09:21 AM https://www.ebay.com/itm/PHILIPS-DIAGNOST-X-Ray-31-38CM-9896-010-23251-91073980-Thales-Linox-XR-HELIFLEX/323241163817 19-Dec-18 09:21 AM any idea what this could be? 19-Dec-18 09:21 AM looks like the imaging unit from an xray, after the fluorscent screen 19-Dec-18 09:21 AM the "THALES ELECTRON DEVICES" makes it rather interesting 19-Dec-18 09:34 AM thales builds medical xrays 19-Dec-18 09:34 AM not only mil stuff 19-Dec-18 09:34 AM but i've no idea, what that is 19-Dec-18 09:34 AM but i guess it's not a nano/micro-xray-source 19-Dec-18 10:00 AM Thales builds all sorts of tubes in general. Klystrons, magnetrons, etc. This looks like one of their medical xray units parts 19-Dec-18 10:00 AM https://www.thalesgroup.com/en/global/activities/market-specific-solutions/microwave-imaging-sub-systems/medical-imaging-0 19-Dec-18 10:48 AM ah, then it's probably a CCD 19-Dec-18 11:05 AM Anybody here into lasers? I have a neat pulsed laser. Maybe I can do something fun with it in a vacuum... 19-Dec-18 11:07 AM Definitely, what type of laser? 19-Dec-18 11:08 AM It's a Spectra Physics HIPPO 19-Dec-18 11:08 AM 1064nm q-switched pulsed. I really wish I could find the harmonic generators for it to try different wavelengths 19-Dec-18 11:08 AM I've used it to pattern copper traces to make PCBs. 19-Dec-18 11:14 AM Photo emission EM work is fun 19-Dec-18 11:14 AM Nice! I've got a couple of crazy laser experiments I will be running with my setup down the road you may be interested in 19-Dec-18 11:17 AM Cool, what kinds of experiments? 19-Dec-18 11:23 AM I won't get into specifics yet (I will definitely release info when the time is right though!), but it will be laser generation rather than using a laser specifically for diagnostics. I will say if it works, it's going to open up a whole field of high power lasers that has never been touched or even remotely approached the maker level before 19-Dec-18 11:23 AM Welp time to get funranium in here 19-Dec-18 11:24 AM What (or who) is funranium? 19-Dec-18 11:24 AM Twitter's designated laser safety officer 19-Dec-18 11:25 AM @Applied_Ion like a material processing laser for makers? 19-Dec-18 11:25 AM Check out Funranium Labs (@funranium): https://twitter.com/funranium?s=09 19-Dec-18 11:26 AM No, it's a whole different laser field for sure. I'm willing to bet 100% there is not a maker on the planet with these types of laser systems 19-Dec-18 11:26 AM ultrafast lasers? I wish I was a maker with one of those... 19-Dec-18 11:27 AM @piGuy , @OiD is your man. He collects lasers, neon, ruby...all 19-Dec-18 11:27 AM Sadly no, though ultrafast lasers would be awesome to do 19-Dec-18 11:27 AM Though this laser is way more fun (in my biased opinion lol) 19-Dec-18 11:28 AM Now I'm going to go crazy trying to figure it out 19-Dec-18 11:28 AM Huh, I actually don't follow funranium. I'll check out his stuff 19-Dec-18 11:28 AM Thanks Nixie. Good to know there are more people here that share my sickness. 19-Dec-18 11:30 AM Sickness is not a word employed here. 19-Dec-18 11:30 AM I am into them, but not as much. 19-Dec-18 11:33 AM Laser drivers is what I'm really into, especially pulsed lasers. One day I want to build a high power magnetic pulse compressor for fast eximer lasers 19-Dec-18 11:34 AM @Applied_Ion someday, a bunch of us are going to kidnap you, strap you comfortably into a chair, offer biscuits and tea, and pleasantly extract the whole lot of information from your projects, probably using pillows and rainbows if you don't release info soon. 19-Dec-18 11:34 AM Believe me, I'm itching to release details lol 19-Dec-18 11:35 AM Because nobody expects the Spanish Inquisition! 19-Dec-18 11:35 AM I want an excimer laser. I played with one briefly at some university in china 19-Dec-18 11:35 AM (and double pun, with me being spaniard) 19-Dec-18 11:36 AM I know it's petty, but there are a lot of makers with way more money than me that could afford to beat me to the punch on this stuff. I kind if want to be the first for these systems, I've spent many hundreds of hours of research and planning so far lol 19-Dec-18 11:36 AM You underestimate how lazy people are. 19-Dec-18 11:36 AM Even if it doesn't work, once it's out there then someone else could take the torch and build upon it, but I definitely expect good results 19-Dec-18 11:36 AM Like I want the maker community to expand on this field 19-Dec-18 11:37 AM Of course, I can't tell you about my secret projects either. 19-Dec-18 11:37 AM It won't be secret hopefully for long, it will be open source 19-Dec-18 11:37 AM But I want to get to a certain stage before details are out 19-Dec-18 11:37 AM I was my mom's secret project for years. It didn't work out. 19-Dec-18 11:39 AM @Applied_Ion absolutely! I'm just itching to see it, and I like to mess with you. 19-Dec-18 11:39 AM I tried making a glass laser once. I was casting sol-gel silica doped with ytterbium. 19-Dec-18 11:39 AM Nice! How far did you get with that? 19-Dec-18 11:41 AM Well the silica needed to have high porosity so it wouldn't crack while drying. Then you're supposed to cook it at 1400C to collapse the pores and make it solid glass. But my furnace only goes to 1200C so I was out of luck. 19-Dec-18 11:41 AM Kind of a fun technique to just pour liquid into a container to make glass, like making Jello. 19-Dec-18 11:51 AM In other words, I didn't get very far. 19-Dec-18 11:53 AM Still doesn't hurt to give it a try 19-Dec-18 11:55 AM What do you guys do for a living? 19-Dec-18 11:56 AM Electrical engineer for an electron linear accelerator 19-Dec-18 11:56 AM What about you? 19-Dec-18 12:00 PM Previously was an aerospace engineer and researcher in bioengineering, currently trying to do a startup in the DIY Bio field 19-Dec-18 12:02 PM Cool! I've considered start up stuff for the micro propulsion and particle beam fields with a spin towards more open source and low cost solutions, but it's tough and risky 19-Dec-18 12:04 PM micropropulsion for something like cubesats? 19-Dec-18 12:05 PM Yeah. I actually have my chamber fully designed and emgineered. Everything ready for it except bolts and gaskets. It's one of the 3 chambers I am working on 19-Dec-18 12:05 PM me I missed @AdamMcCombs again 19-Dec-18 12:05 PM I'm still here 19-Dec-18 12:05 PM ah yay 19-Dec-18 12:05 PM You wanted to know what's my plan 19-Dec-18 12:05 PM https://www.ebay.com/itm/163399412057 19-Dec-18 12:05 PM I want to buy this head and get it working 19-Dec-18 12:05 PM afaik ist has two magnetic lenses 19-Dec-18 12:05 PM I wanted to know if it is generally possible to get something like this working without any docs... Just using a multimeter and lab bench power supplies for the optics 19-Dec-18 12:09 PM That's a hard one 19-Dec-18 12:09 PM Yes but at some risk 19-Dec-18 12:09 PM You can just start guessing lens currents, but going to far... 19-Dec-18 12:10 PM One of the big challenges goes back to the filament isolation transformer 19-Dec-18 12:11 PM It's much more complicated if any sort of alingnment coils are needed 19-Dec-18 12:29 PM I don't know if such coils exist 19-Dec-18 12:29 PM @Applied_Ion , how big is the electron linear accelerator you work at? 19-Dec-18 12:29 PM https://de.caeonline.com/buy/x-ray/ge-phoenix-nanomex-160/9194605 19-Dec-18 12:29 PM here are some images 19-Dec-18 12:30 PM Ah 19-Dec-18 12:30 PM Cae 19-Dec-18 12:30 PM My old "friend" 19-Dec-18 12:31 PM https://cdn.caeonline.com/images/ge-phoenix_nanomex-160_858124.jpg 19-Dec-18 12:32 PM I contacted CAE once about a bench top SEM I was interested in. Now they call me and email me about every single SEM they have. 19-Dec-18 12:32 PM bottom connector is for coils and potential other stuff, above the TMP + vacuum gauge, on the very top the 160kV high voltage cable 19-Dec-18 12:39 PM @piGuy it's a 60MeV machine, though we are in the process of upgrading to a brand new 140MeV machine. This one is still in use, probably for another year or so. Been around since the 60s, came online about the same time as SLAC 19-Dec-18 12:53 PM How risky is it to buy a used TMP? 19-Dec-18 12:59 PM It depends, generally much more risky than a diff pump. Never purchased one, but it ranges from non functioning to great condition. You looking at something from ebay? 19-Dec-18 12:59 PM The sellers generally aren't in the position to test functionality, or usually have much knowledge on them 19-Dec-18 01:02 PM I'm probably most concerned about the explosion risk 19-Dec-18 01:02 PM They can't explode 19-Dec-18 01:02 PM The vanes are generally fragile, which is why they can be damaged so easily 19-Dec-18 01:03 PM Are they designed to contain the rotor if it fails? 19-Dec-18 01:03 PM Yeah, the rotor isn't getting through the body if it fails. Fins will mangle and shred 19-Dec-18 01:04 PM I just have too many questions. I could overwhelm this channel with questions about everything vacuum related. 19-Dec-18 01:04 PM From what I have heard, a common failure point is the bearings, which can be tricky to change, but do able 19-Dec-18 01:04 PM Well, this is the vacuum hackers chat lol, plenty that can be answered by someone here 19-Dec-18 01:06 PM I'd like to put together a vacuum system, but right now I don't have much other than a dry scroll pump and a pirani gauge and a few hoses and fittings. 19-Dec-18 01:06 PM A dry scroll pump is a great pump to have, not many people with that, very expensive. Is it one that requires backing? 19-Dec-18 01:07 PM No it's just an Edwards XDS10 19-Dec-18 01:07 PM I'm interested in doing PVD coatings 19-Dec-18 01:09 PM Well if you need pointers on vacuum engineering, I can probably help out with most questions. I way over engineered my own system, including thermal, full vacuum calculations/outgassing loads, and Molflow simulations for pumping 19-Dec-18 01:09 PM Also wrote uo a long tutorial on how I approached the design of one of my systems 19-Dec-18 01:11 PM I think the most intimidating thing to me is finding a chamber 19-Dec-18 01:14 PM It all depends on what you are looking to do. The key is doing a lot of thorough research ahead of time and familiarizing yourself with vacuum tech and the process you are aiming to do. The chamber itself is not too tough to figure out after 19-Dec-18 01:14 PM Joined the server. 19-Dec-18 01:16 PM Joined the server. 19-Dec-18 01:16 PM hey 19-Dec-18 01:16 PM chirp 19-Dec-18 01:17 PM @piGuy so are you looking to do stuff like magnetron sputtering? 19-Dec-18 01:21 PM I think I'm leaning more towards thermal evaporation rather than magnetron sputtering. 19-Dec-18 01:21 PM Is something like this a reasonable/good value for a high vacuum gauge? https://www.ebay.com/itm/Pfeiffer-IKR-251-Compact-Cold-Cathode-Vacuum-Gauge-KF-Flange-with-Cable-2/153307850970?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D1%26asc%3D20131003132420%26meid%3D4cb778e6be9e49aa9cc4ac9514f192a2%26pid%3D100005%26rk%3D2%26rkt%3D2%26sd%3D233027345599%26itm%3D153307850970&_trksid=p2047675.c100005.m1851 19-Dec-18 01:23 PM Oh thermal evap is even easier! 19-Dec-18 01:23 PM and I might want to try ablating some stuff with my laser in a vacuum... 19-Dec-18 01:24 PM That's a reasonable price for a cold cathode gauge. Definitely negotiate down though if you can 19-Dec-18 01:24 PM Actually, you can do thermal evap with bell jar chamber, depends on the level you are looking to achieve. Lower vacuum is better for evap. Magnetron sputtering can afford to run at higher pressure 19-Dec-18 01:24 PM For the laser, chances are you will want to couple that in externally. Since yours is YAG, through an IR transparent vacuum viewport. 19-Dec-18 01:27 PM I suppose if I actually get my SEM working, I'll want magnetron sputtering for sample prep 19-Dec-18 01:27 PM Nice you got a sem too? 19-Dec-18 01:27 PM Yeah I have a small laser window that may or may not work. 25mm dia but only 3mm thick. Not sure if it's thick enough for vacuum 19-Dec-18 01:27 PM @Nixie does a lot with magnetron sputtering 19-Dec-18 01:28 PM Yeah I picked up a JEOL Neoscope desktop SEM 19-Dec-18 01:30 PM You can get a ton of different window materials and IR viewports from Thorlabs for IR conflat. We are actually getting one for some imaging of a system under vacuun 19-Dec-18 01:30 PM https://www.thorlabs.com/navigation.cfm?guide_id=2326 19-Dec-18 01:30 PM https://www.thorlabs.com/navigation.cfm?guide_id=2367 19-Dec-18 01:35 PM Ok, cool. Looks like those windows are thicker than mine, so I'll probably have to get a new one 19-Dec-18 01:37 PM yeah, 25mm D at 3mm may be a bit risky, though it depends on the unsupported area of the window and the material 19-Dec-18 01:37 PM actually, the ones from thorlabs come in either 3mm or 5mm thickness 19-Dec-18 01:37 PM seems like your window is actually the same size as there's you are probably good 19-Dec-18 01:37 PM they have the flat window conflat adapter ports for the 25mm diameter windows, which yours would fit since it is the same standard as theirs 19-Dec-18 01:37 PM this is the one you would probably be looking at, as long as your window is a flat window: 19-Dec-18 01:37 PM https://www.thorlabs.com/thorproduct.cfm?partnumber=VPCH12-FL 19-Dec-18 01:41 PM Different thickness though. 5.0mm vs my 3.0mm 19-Dec-18 01:42 PM yeah you are right, my bad. Only the 12.7mm diameter ones are 3mm 19-Dec-18 01:42 PM they only have conflat adapters for the 25mm D ones 19-Dec-18 01:42 PM you could make one yourself, depending on what machining capabilities you have 19-Dec-18 01:44 PM I put an offer in on the gauge. Maybe there will be a Christmas miracle. 19-Dec-18 01:50 PM it is good that the seller states it is guaranteed to function. There are a bunch for a bit cheaper, but are being sold untested, so at least you are getting a guaranteed working gauge. Hopefully they accept your offer and it actually functions as described 19-Dec-18 02:03 PM @JanHenrik welcome! 19-Dec-18 02:03 PM I find that thermal evaporation is worse in all aspects compared to magnetron. It requires expensive tungsten boats, demands high current feedthroughs, and won't work with alloys or certain materials. 19-Dec-18 02:06 PM It's very useful in a lot of cases though 19-Dec-18 02:06 PM Sure, but I don't like to depend on certain supplies I can't easily substitute. 19-Dec-18 02:06 PM As for vacuum chambers, @piGuy , mine is the worst-acceptable-piece-of-crap you can throw together from a few components. If mine works, anything you build, will too. 19-Dec-18 02:06 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181212_002008-A258A.jpg 19-Dec-18 02:06 PM Glass from a beer machine viewport (borosilicate), aluminium and stainless endplates. 19-Dec-18 02:10 PM Is a magentron setup more difficult or expensive to get up and running? 19-Dec-18 02:10 PM Less 19-Dec-18 02:11 PM It is cheaper, from my viewpoint. But depends if younare in the US 19-Dec-18 02:11 PM More machine work but less vacuum 19-Dec-18 02:11 PM So kinda depends 19-Dec-18 02:11 PM Tabletop sputter coaters for sem are nice... 19-Dec-18 02:12 PM At what price? 19-Dec-18 02:12 PM Anyways, in US you cand find parts much cheaper. Also in Germany. 19-Dec-18 02:13 PM Ideally I'd like to do some roll to roll coating. The only used machines I've seen for that are huge and expensive. 19-Dec-18 02:13 PM Wut? Those that sputter from a rotating drum? 19-Dec-18 02:14 PM like they take a roll of film and sputter onto it 19-Dec-18 02:14 PM Ah 19-Dec-18 02:14 PM I want to do that to make capacitors 19-Dec-18 02:14 PM Should be doable. 19-Dec-18 02:14 PM I developed glass rotary feedthroughs, if you can't find comercial ones for cheap. 19-Dec-18 02:14 PM https://youtu.be/_BD2sEOMzJg 19-Dec-18 02:14 PM Instead of the manual control setup, a simple stepper/slow motor can be attached to the outside. 19-Dec-18 02:19 PM How is it made? 19-Dec-18 02:19 PM (my chamber geometry would require some 90° translationsin the axes but can be done) 19-Dec-18 02:19 PM In few words: a borosilicate test tube gets the end shaped to interface into a KF16 port. Teflon magnet holders attach to stainless tubes. That gets actuated from the outside with other magnets. 19-Dec-18 02:19 PM For more, go check the book "compendium!" In here: https://hackaday.io/project/107598/files 19-Dec-18 02:27 PM That compendium looks amazing. I have a lot of reading to do... 19-Dec-18 02:30 PM I think thermal evaporation is more used for coating large films due to high deposition speed and production volume capability over magnetron. Magnetron is much preferred for semiconductors, but large surface coatings at higher deposition speeds thermal evap wins 19-Dec-18 02:30 PM I wouldn't say it's necessarily more expensive or difficult. Depends on a bunch of factors, but from a diy perspective I think both are on par for cost and difficulty. All depends on what level of control and results you are after. Though as a process I do much prefer magnetron, much cooler lol 19-Dec-18 02:33 PM Plasma wins 19-Dec-18 02:33 PM I don't know if anyone on the diy side has tried high power pulsed magnetron sputtering 19-Dec-18 02:33 PM Yeah plasma wins for sure 19-Dec-18 02:33 PM You did? What levels? 19-Dec-18 02:34 PM I did. 19-Dec-18 02:34 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_-k1v5wo-A8BAE.jpg 19-Dec-18 02:34 PM I was joking with the other day's target meltdown 19-Dec-18 02:34 PM @piGuy glad you like the book It's mainly photos, so not that much to read actually. 19-Dec-18 02:36 PM What target metals can be used with DIY magnetron sputtering? 19-Dec-18 02:36 PM Anything conductive 19-Dec-18 02:37 PM Was that from actual HIPIMS? 19-Dec-18 02:37 PM I have done aluminium, copper and titanium. 19-Dec-18 02:37 PM RF sputtering can do non conductive too 19-Dec-18 02:38 PM Nope, no HIPIMS, just plain old 300w constant power. I'm not that cool. 19-Dec-18 02:38 PM But rf sputtering gets complicated. 19-Dec-18 02:38 PM DC sputtering is super simple, in comparison. 19-Dec-18 02:38 PM You'll need argon OR waiting for the oxygen in the chamber to deplete. I use regular welding argon and works fine. 19-Dec-18 02:38 PM @Applied_Ion i like.messing with you, just ignore me. 19-Dec-18 02:43 PM Oh yeah dc is the easiest by far. RF would not actually be that tough to do. High power tube oscillator supply would be cheap and easy to build. HIPIMS would also be relatively easy as well. @Nixie for a second you got me excited about you experimenting with HIPIMS lol 19-Dec-18 02:43 PM Mission accomplished! Victory dance 19-Dec-18 02:45 PM What exactly is hard in RF sputtering? 19-Dec-18 02:45 PM The easy to build, coming from you has to be taken with a grain of salt. 19-Dec-18 02:45 PM And what is "high power"? 100W? 1kW? 100kW? 19-Dec-18 02:45 PM Rf requires high power rf source, a specific frequency and antennas that work at that frequency. 19-Dec-18 02:46 PM High power for HIPIMS is pretty low relatively speaking, around like 10kw pulsed. That's pocket change to do lol 19-Dec-18 02:46 PM It makes.my head hurt. 19-Dec-18 02:46 PM 10kW pulsed RF? 19-Dec-18 02:46 PM Bahaah 19-Dec-18 02:47 PM No, RF is continuous 19-Dec-18 02:47 PM HIPIMS is pulsed dc 19-Dec-18 02:48 PM Ah, ok 19-Dec-18 02:48 PM I have to go, my planet needs me Byeeee. 19-Dec-18 02:48 PM was briefly thinking about surplus soviet magnetrons 19-Dec-18 02:48 PM Yeah that will get you there easily 19-Dec-18 02:48 PM But for RF at the 27.12MHz for 100-350W is quite cheap. 19-Dec-18 02:49 PM Yeah, plenty of tubes on ebay cheap that can get you to that level 19-Dec-18 02:49 PM a 50eur amplifier driven with a 50eur CB radio as the exiter will do it 19-Dec-18 02:49 PM 100W of 27MHz 19-Dec-18 02:49 PM Tubes are only easy and cheap if you have a good high voltage PSU 19-Dec-18 02:50 PM I've seen 5kW CW rated tubes for about $100 on ebay 19-Dec-18 02:50 PM using modern mosfets gets much cheaper when you can use 24V or 50V instead of 3kV 19-Dec-18 02:50 PM The tube is cheap, the socket, mechanics, the vacuum caps for the output network and the PSU are not 19-Dec-18 02:51 PM Build it yourself 19-Dec-18 02:51 PM I have a 10kW tube in my junkbox. 4CX5000A 19-Dec-18 02:51 PM Oh nice! 19-Dec-18 02:51 PM Continuous or pulsed? 19-Dec-18 02:52 PM It requires 7.5kV 19-Dec-18 02:52 PM Continous 19-Dec-18 02:52 PM 10kW up to 100MHz in the spec 19-Dec-18 02:53 PM That's pretty awesome 19-Dec-18 02:53 PM Nah. It's a cool thing but unusable in practical terms 19-Dec-18 02:53 PM Sockets are hard to find and cost money 19-Dec-18 02:53 PM It would take more than 1000eur to build an amplifier around it 19-Dec-18 02:53 PM Little less if just building a power oscillator 19-Dec-18 02:56 PM why is that? 19-Dec-18 02:56 PM i haven't looked into high power tube applications yet, but i'm interested... got some russian power tubes lying around 19-Dec-18 02:59 PM In a power oscillator you can skip some of the output network of the amplifier 19-Dec-18 03:02 PM I'd say that's very usable/practical for rf plasmas. You could build a real mean atmospheric rf torch with that 19-Dec-18 03:04 PM Sure 19-Dec-18 03:13 PM Socket could be built yourself. For diy system on the cheap, efficiency and great matching isn't that necessary if you have enough overhead in terms of power. The prospect of high power rf plasma is plenty motivation in my book to tackle that tube head on! Though I'm sure the filament alone has got to have some pretty high power requirements itself. Rectified MOT stack could at least give you a few kW of high voltage power relatively cheap. Biggest obstacle would be upgrading your breakers to handle the full load of the filament and HV supply. 19-Dec-18 03:15 PM or just wind a transformer yourself, it's not that hard 19-Dec-18 03:15 PM 270W of dissipation in the filament alone 19-Dec-18 03:16 PM Not bad, though pretty high in terms of tubes still 19-Dec-18 03:16 PM But very do able to power 19-Dec-18 03:17 PM slightly over 1 amp on the mains side 19-Dec-18 03:17 PM And it's a steel+ceramic tetrode with a coaxial socket 19-Dec-18 03:18 PM for coax sockets: i have samples from a supplier of copper-beryllium spring contacts somewhere. those are perfect for custom tube sockets 19-Dec-18 03:19 PM eimac rates 4cx5000a for Minimum of 547W of filament power and maximum of 585W of filament dissipation. Must have remembered some other tube 19-Dec-18 03:19 PM It needs 7.5kV at 3A for normal operation 19-Dec-18 03:20 PM Yeah, standard for high powered tube. A full socket wouldn't necessarily by needed, you could make the connections to the electrodes. I've made fingers stock pcb sockets for tubes at work before, definetly doable for cheap 19-Dec-18 03:20 PM You can run the tube at reduced power input as long as the filament is fully powered though, no need to run full 10kw in 19-Dec-18 03:20 PM Yea 19-Dec-18 03:27 PM on the topic of custom built high voltage transformers: https://web.archive.org/web/20161006195419/http://www.hochspannung-bildhauerei.de/transformatoren.html 19-Dec-18 03:27 PM yes, i know, it's in german, but interesting nontheless 19-Dec-18 03:27 PM and the guy wrote a book, published by Franzis, about the construction of transformers like that 19-Dec-18 03:34 PM Very cool! Though I'm sure it costs a lot of money to do still. And it's tough to get access to that much power in the home, few have the space or power requirements 19-Dec-18 03:34 PM Yeah 19-Dec-18 03:34 PM I know the most hardcore teslacoil guy in Finland (Kizmox on youtube) has 63A triphase at an industrial property. 19-Dec-18 03:37 PM i think my parent's house gets 32A threephase... biggest outlets are 16A 3~. and in my flat i have 16A 3~ as well 19-Dec-18 03:37 PM and i love it - my big rotary vane pump needs threephase power :-D 19-Dec-18 03:38 PM Honestly though, from the physics application standpoint, it's kind of a waste to just make sparks. Everyone always tries to make the longest sparks possible, but no one tries to do much else with them. Sparks are easy - driving real loads is the tough part. Beautiful high voltage machines just making long arcs and not much else. With that much voltage and current, there's a lot of real physics you can do with that. 19-Dec-18 03:38 PM What type of pump? That's a pretty heft load for a rotary vane! 19-Dec-18 03:39 PM 32A triphase is still quite common here 19-Dec-18 03:39 PM @Applied_Ion the best thing would be no sparks at highest voltages... in a linac... :3 19-Dec-18 03:39 PM and the pump is an old Alcatel model... T2030 i think 19-Dec-18 03:42 PM @Pan Da give me a few months on that... For me, it's all about peak power. Even tesla coils have very real applications beyond just sparks (not talking energy transfer or the common applications). 19-Dec-18 03:42 PM What are you using the 3 phase pump for? 19-Dec-18 03:44 PM @Applied_Ion that kind of power is no issue at all in europe 19-Dec-18 03:44 PM since it's my only functional rotary vane pump at the moment - everything 19-Dec-18 03:44 PM most flats have 63A 3 phase 19-Dec-18 03:45 PM Yeah 3 phase in residential homes in the US is not common 19-Dec-18 03:46 PM ha, i knew it - i had the catalog data of the pump somewhere. it says 35m³/h and better than 10e-4mbar. with a weight of 48kg, 2l of oil and 1,1kW electrical power input. :-D 19-Dec-18 03:46 PM yes american residential power is completely unworkable imo 19-Dec-18 03:46 PM That's impressive lol, beats the crap out of my cheap rotary vane refrigeration pump 19-Dec-18 03:46 PM That's why I like pulsed power. Unreal output power levels at incredibly low input 19-Dec-18 03:47 PM american power grid is... very broken imho 19-Dec-18 03:47 PM and yeah, a lot of work went into that pump... i got it in a pretty bad condition. mud inside, completely stuck, original o-rings from 1980, aluminium debris in both stages, scratched vanes... 19-Dec-18 03:50 PM yeah, they are the workhorses usually 19-Dec-18 03:50 PM I got a few broken ones that are not worth the rebuild 19-Dec-18 03:52 PM but hey, i got it for free, invested some 200 euros in new rings and seals, another 100 Euro in oil and rebuilt the thing. i just wish i could let it run more frequently... the long open storage times are not good for the oil, i think 19-Dec-18 03:52 PM @sync why are they not worth? are they cheap chinese pumps, or just fubar? 19-Dec-18 03:52 PM Sounds like a good deal, and probably learned a lot from rebuilding it too 19-Dec-18 03:53 PM you can get working ones for under 300€ so they are just scrap metal 19-Dec-18 03:53 PM and getting the rusted innards apart is not worth the time and effort 19-Dec-18 03:54 PM @Applied_Ion yes, i think i had no idea how those things work when i started disassembling it. 19-Dec-18 03:54 PM if you store the pump for extended times just run it with the gas ballast running for some hours and it will be fine 19-Dec-18 03:55 PM ewwwwwwww, rust in pumps is pretty bad... i wouldn't want to regrind the stages 19-Dec-18 03:55 PM the inner running surfaces usually are fine 19-Dec-18 03:55 PM but the rest is a rustbucket 19-Dec-18 03:56 PM and yeah, just running it to outgas is fine, but i think i'll need to take it apart again before i can really start using it... there is an oil leak somewhere, i always need to top it off after a few weeks 19-Dec-18 03:56 PM oh, so with your pumps, the surfaces are fine because they were kept free by the vanes, but everything else begins to rot when the oil has too much moisture? 19-Dec-18 03:58 PM yeah 19-Dec-18 03:58 PM it is probably the sealing ring in the back of the pump housing 19-Dec-18 03:58 PM that usually grinds a groove into the shaft 19-Dec-18 04:00 PM ew. 19-Dec-18 04:00 PM i have one pump here... or rather, two partial pumps... edwards EDM2 i think. they are both beyond repair, but hey, i want them to work... 19-Dec-18 04:00 PM on one the motor burnt out, on the other one the pump stages are damaged, so at some point in the future i will try to rebuild one working pump from the good parts and scrap the rest 19-Dec-18 06:28 PM Came here for help on my SEM, then you guys get me jazzed up about vacuum stuff, next thing you know I'm buying vacuum gear on eBay... 19-Dec-18 06:55 PM Sounds about right 19-Dec-18 10:36 PM Morning! 19-Dec-18 10:36 PM Now that we are talking rf, why is 13-ish Mhz the preferred frequency for sputtering? 19-Dec-18 10:37 PM That's the designated band for industrial processes. 13.56 MHz 19-Dec-18 10:37 PM @piGuy show us what you got! 19-Dec-18 10:37 PM But why? 19-Dec-18 10:37 PM Ah, like the bands for military and civil coms? 19-Dec-18 10:39 PM Yeah, for interference purposes 19-Dec-18 10:40 PM Then I can just use a rf generator from ebay and a cheap amplifier at some other frequency? (For testing) 19-Dec-18 10:40 PM Hmmmm 19-Dec-18 10:40 PM clinges to the wall, this is a slippery slope 19-Dec-18 10:41 PM That's the frequency you want to be in so you don't interfere lol 19-Dec-18 10:41 PM Repeats the mantra "I only need DC, I only need DC..." 19-Dec-18 10:41 PM XD, got it. 19-Dec-18 10:47 PM @Nixie - nothing too crazy YET, just this: https://www.ebay.com/itm/BOC-EDWARDS-ACTIVE-GAUGE-AIM-SL-NW25-D14644000/273571436095?epid=1836672703&hash=item3fb220d63f:g:Hp4AAOSwFSNb9NWW:rk:2:pf:0 19-Dec-18 10:54 PM 20-Dec-18 12:37 AM It's just a slight water leak what's the big deal? 20-Dec-18 12:37 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181219_213822-0EE46.jpg 20-Dec-18 01:06 AM no worries, just top it off daily 20-Dec-18 01:06 AM good morning! 20-Dec-18 01:46 AM moin 20-Dec-18 02:53 AM Moin 20-Dec-18 05:31 AM @Nixie for MHz and below plasma there is no tuned antenna in the chamber, you just connect the feed to whatever. Different for microwave. And it is also not necessary to match the load to be resistive, especially when the generator is close to the chamber, as it would likely be. But you do need a high enough output voltage to start the discharge, which implies an output impedance >50 Ohm if you are in the 10-100 watt range. I have made a class E generator which is quite simple, but have not gotten it to make plasma, and this project is on the back burner at the moment. 20-Dec-18 05:39 AM Ohhh, so, If I made a powerful enough RF generator, I could just plug it in into my glass vacuum chamber as is? 20-Dec-18 05:39 AM (it uses the endplates as A & K ) 20-Dec-18 06:24 AM Yes. Also for a small chamber you are probably talking 200-300 watts max. There is the same issue as with dc that your get arcing if the current is too high (max power proportional to cathode area), and you do need cooling to get the power back out again. My impression is that HF and microwave plasma are used mainly for partly chemical processes like PECVD and RIE. One big use of HF is to create negative bias on an insulating substrate, or similarly, for plasma cleaning insulating substrates. You can use HF sputtering to deposit insulating materials, or to tolerate insulating deposits, such as with reactive sputtering, but this is now often done using pulse dc, which is cheaper and more efficient. With reactive sputtering, you sputter a metal target, and then it reacts with O2 or N2 on the substrate, forming your oxide or nitride film. 20-Dec-18 06:39 AM The reason I started going down the HF path was because the article I found on hollow cathode deposition used HF. But I tried DC, and that worked well with titanium, so I haven't gone back to the HF. Possibly HF would give a more stable discharge, especially with the aluminum. Anyway, the advantage of AC is that it can "flow through" an insulator. This is relevant if you are sputtering an insulating target or have an insulating substrate. Also, you can excite the plasma thru an insulator by inductive or capacitive coupling, which is useful if you are trying to create a plasma without any contamination by electrode material or wear-out due to electrode erosion. 20-Dec-18 06:54 AM Sort of knew parts of that. And yes, at some point I have to put it into action, for example to sputter SiO2 to cover the chip and protect it, for example. 20-Dec-18 06:54 AM My target holder is watercooled, so I should be fine, I guess. 20-Dec-18 07:02 AM With AC both sides take turns being the cathode, so everything is going to heat up. The magnetron is non functional when polarity is reversed, which is why HF sputtering is <50% power efficient w.r.t. DC, even without considering extra losses in the generator. IIRC semiconductor fab uses CVD from eg. silane + O2, rather than direct sputtering of SiO2. But of course silane is toxic as heck. 20-Dec-18 07:05 AM Not gonna touch silane. XD 20-Dec-18 07:05 AM Might have to be careful with the other endplate, but for small depositions, I should be safe. I wonder if it is possible to offset the RF and increase power in the cathode that has the magnets. 20-Dec-18 07:05 AM Like you do when welding aluminium, switching between heat input in the piece and cleaning effect of the arc. 20-Dec-18 07:55 AM silane isn't really dangerous, it burns when it comes out of the bottle, but apart from that 20-Dec-18 07:55 AM arsine and phosphine are much worse 20-Dec-18 08:57 AM I would just prefer to use solid sources. 20-Dec-18 10:37 AM @sync are you from Hannover? 20-Dec-18 11:53 PM Morning!! \o/ 21-Dec-18 12:48 AM moin 21-Dec-18 01:09 AM moin! 21-Dec-18 04:59 AM moin 21-Dec-18 05:20 AM Btw, am I the only one who gets his head messed up with the people that haven't changed the basic discord logo as avatars? It's like people not having faceeeeeeees. 21-Dec-18 06:49 AM I know, I mostly go by profile pictures as well 21-Dec-18 06:49 AM it's even worse when someone changes theirs 21-Dec-18 07:31 AM yeah, i also don't like profile pictures... oh wait. 21-Dec-18 07:31 AM :-D 21-Dec-18 07:33 AM well go and get one! 21-Dec-18 07:55 AM XDDDDDDDDDDD 21-Dec-18 08:00 AM I've been thinking about trying to build a DC magnetron sputter system and realized I happen to have a 600V electrophoresis power supply laying around. Any chance that 600V might be enough for a small setup? 21-Dec-18 08:01 AM should work! 21-Dec-18 08:01 AM my setup works at around 550V 0,5A 21-Dec-18 08:01 AM how much current can it supply? 21-Dec-18 08:01 AM (100mm between electrodes, btw) 21-Dec-18 08:02 AM I watched Ben Krasnow's video where he said he tried an electrohpersis power supply and wasn't happy with it, but it seemed like his complaints were specific to his power supply. 21-Dec-18 08:03 AM Not sure a DNA machine can supply 250W 21-Dec-18 08:03 AM 600V, 500mA, 150W 21-Dec-18 08:03 AM hum...should suffice, in theory. 21-Dec-18 08:03 AM wait. 150W? 21-Dec-18 08:03 AM then it's going to limit Vout at some point 21-Dec-18 08:04 AM well I'm assuming 250mA at 600V 21-Dec-18 08:04 AM Hmmm...could work. but you don't have much margin left. 21-Dec-18 08:04 AM Anyways, if it works erratically, you can always build the power supply later. 21-Dec-18 08:05 AM yeah that's true 21-Dec-18 08:05 AM Keeping my eye on this: https://www.ebay.com/itm/boc-edwards-EXT-70H-B722-21-000-vacuum-pump/292880686353?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20160908105057%26meid%3Da35ebc65aef54740971e6768552a697e%26pid%3D100675%26rk%3D2%26rkt%3D15%26sd%3D173679183110%26itm%3D292880686353&_trksid=p2481888.c100675.m4236&_trkparms=pageci%3A3d7ff9ec-053a-11e9-ac7d-74dbd18097b5%7Cparentrq%3Ad183bc8c1670aa472ebb41b4fff968ab%7Ciid%3A1 21-Dec-18 08:06 AM Nice! but no driver, right? 21-Dec-18 08:07 AM Driver can be found for about $100 21-Dec-18 08:08 AM Niiiice! 21-Dec-18 08:09 AM No sniping! 21-Dec-18 08:09 AM nice! 21-Dec-18 08:09 AM (messing with OiD, irl friend) 21-Dec-18 08:10 AM It's a small TMP but I think it would be enough for a small sputtering setup 21-Dec-18 08:10 AM wait 21-Dec-18 08:10 AM you don't need a TMP for a sputtering setup 21-Dec-18 08:10 AM (buy it anyways if you can afford it, will become handy later anyways) 21-Dec-18 08:10 AM in fact a TMP will make your setup impossible to run. 21-Dec-18 08:10 AM you need some gas in the chamber to make the plasma. 21-Dec-18 08:11 AM I thought maybe you need TMP to get as much O2 out before filling chamber with argon... 21-Dec-18 08:12 AM you can just flush the chamber 21-Dec-18 08:12 AM exactly 21-Dec-18 08:12 AM i think argon might be cheaper than a tmp XD 21-Dec-18 08:13 AM I do a pair of flushings, then wait for the o2 to react elsewhere. 21-Dec-18 08:13 AM Depends. 21-Dec-18 08:13 AM But at least for me, yes, it's cheaper than a TMP for sure. 21-Dec-18 08:15 AM hmmm. what about just sputtering with another target until the O2 is gone? so... a diy getter pump, i guess? 21-Dec-18 08:16 AM I guess you can switch magnet positions... 21-Dec-18 08:16 AM I cover my sample with the glass feedthrough. 21-Dec-18 08:17 AM I think I read pressure is like 100mbar for sputtering? 21-Dec-18 08:17 AM Can't measure it yet, sorry. 21-Dec-18 08:17 AM but it's more than 66 microns of mercury, for sure. 21-Dec-18 08:17 AM and I would say 100mbar is too much, will arc like a beast. 21-Dec-18 08:17 AM I'd say between 0,53 and 0,26mbar (400 to 200 microns) 21-Dec-18 08:26 AM I thought a sputtering system would be a good excuse to buy more gear, and I guess I have everything I need already. Darn! 21-Dec-18 08:28 AM but you might want to upgrade the system later 21-Dec-18 08:28 AM i mean, just buy stuff 21-Dec-18 08:28 AM it will come in handy sometime 21-Dec-18 08:29 AM highfives @Pan Da 21-Dec-18 08:30 AM noo, he's a bad influence! 21-Dec-18 08:31 AM How do you control the pressure in the chamber? 21-Dec-18 08:32 AM variable leak aka MFC? :-D 21-Dec-18 08:34 AM I have a servo pressure regulator. I wonder if I could use that as a MFC.... 21-Dec-18 08:34 AM @GigaSquirrel same as you...kid 21-Dec-18 08:35 AM is proud 21-Dec-18 08:35 AM I just let in more argon with my homemade valve. 21-Dec-18 08:36 AM uhh, homemade valve? 21-Dec-18 08:36 AM yeah, problem? 21-Dec-18 08:36 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG-20180322-WA0009-8AE94.jpeg 21-Dec-18 08:37 AM yeah, my problem is not having enough valves 21-Dec-18 08:38 AM (It's missing the o-rings in the photo, it has one at the bottom that performs the actual seal and one at the top of the plunger, to impede gas loss from the top) 21-Dec-18 08:39 AM very cool! 21-Dec-18 09:01 AM It is obviously not as good as a mass flow controller, but does the trick for me. 21-Dec-18 07:30 PM @piGuy oh i can absolutely vouch for the EXT70/EXT250 series btw, i have an EXT250H and an EXDC160 (also an EXDC80 i'm not using...) and it works incredibly well. they're pretty old but pretty durable too 21-Dec-18 07:30 PM bearings might be funky but they go for so cheap sometimes. i hope the auction goes well!! that'd be a great deal if so ~ 21-Dec-18 07:30 PM ... even if you end up not using it at all, more gear's always fun :D 21-Dec-18 09:25 PM Can the bearings be replaced or is the pump trash when the bearings give up? 22-Dec-18 03:27 AM As far as I know, they can be replaced, they are expensive most of the time, tho. (but ebay provides) 22-Dec-18 03:45 AM https://www.pscp.tv/w/1YpKkVpjaZMxj 22-Dec-18 04:37 AM nooo 22-Dec-18 04:37 AM I'de love to watch, but I'm not home :< 22-Dec-18 04:41 AM Yeah same. But with qualia's sleep-rhythm I'll be home before they end the stream :P 22-Dec-18 05:37 AM she's still on 22-Dec-18 05:37 AM (I went to buy some cables) 22-Dec-18 06:24 AM but I won't be home untill tomorrow 22-Dec-18 06:24 AM it's weekend, so they won't have to interrupt for work, maybe I'll still be able to catch the stream xD 22-Dec-18 06:44 AM XDDD 22-Dec-18 03:45 PM finally back home 22-Dec-18 03:45 PM and the livestream is 22-Dec-18 03:45 PM over 22-Dec-18 03:45 PM aww 22-Dec-18 03:50 PM The livestream was over a few hours ago, man. 22-Dec-18 03:52 PM I'll have to catch up tomorrow 22-Dec-18 03:53 PM XD 22-Dec-18 03:53 PM Go to sleep 22-Dec-18 03:53 PM but moooom 22-Dec-18 04:19 PM Bahahaha 22-Dec-18 04:19 PM Or you will be sleepy tomorrow. And there us much to talk about! 22-Dec-18 04:19 PM Btw, will you put another countdown? 22-Dec-18 04:23 PM I won't be sleepy, I'll still get ~10h of sleep, that's the secret 22-Dec-18 04:25 PM XD 22-Dec-18 04:26 PM also I got a 550 ml coffee cup as an early christmas present today :3 22-Dec-18 04:26 PM I'll try not to OD tomorrow 22-Dec-18 04:29 PM Bahahaa 22-Dec-18 04:29 PM OD? 22-Dec-18 04:29 PM overdose 22-Dec-18 04:29 PM /insert Fry gif with 100 cups of cofee/ 22-Dec-18 04:30 PM https://giphy.com/gifs/coffee-gif-brockurealities-DrJm6F9poo4aA 22-Dec-18 04:30 PM Good night 23-Dec-18 12:10 PM So alooooooone... 23-Dec-18 12:10 PM XDDDD 23-Dec-18 12:36 PM Where the dogs at? 23-Dec-18 12:39 PM the general voice chat 23-Dec-18 12:48 PM @OiD join usss 23-Dec-18 12:53 PM How? XD 23-Dec-18 01:00 PM Sorry, can't join this week, out and about travelling 23-Dec-18 01:01 PM ok, have fun! 23-Dec-18 01:04 PM Thanks! Flipping through the voice chat posts, looks like a lot of fun stuff! 24-Dec-18 02:12 AM Good morning and merry christmas! 24-Dec-18 02:34 AM Gmorning! \o/ 24-Dec-18 02:38 AM \o/ 24-Dec-18 02:47 AM merri kristmas from jermanni! 24-Dec-18 02:56 AM Frohe Weihnachten! 24-Dec-18 03:17 AM Ho Ho Ho meine freunde 24-Dec-18 03:17 AM Dies ist nun ein deutscher Weihnachtsserver? 24-Dec-18 03:17 AM offenbar ¯\_(ツ)_/¯ 24-Dec-18 03:27 AM BLITZKRIEG 24-Dec-18 03:27 AM we somehow need a ctf, to determine what language this server has. e.g. the smallest mosfet feature size :D 24-Dec-18 03:29 AM ctf? 24-Dec-18 03:31 AM capture the flag 24-Dec-18 03:31 AM no. 24-Dec-18 03:31 AM you don't challenge germans for ctf. 24-Dec-18 03:31 AM next thing you know, paris has fallen again and there is a reichskriegsflagge on top of the eiffel tower. 24-Dec-18 03:33 AM i dont see the problem? 24-Dec-18 03:33 AM any french here? 24-Dec-18 03:33 AM yeah, right... better than rioting yellowvests i guess 24-Dec-18 03:33 AM otherwise they do it by themselfs :D 24-Dec-18 03:33 AM yeah xD 24-Dec-18 03:47 AM ffs guys 24-Dec-18 04:26 AM I would move to #off-topic-thats-sometimes-on-topic 24-Dec-18 04:27 AM yes, let's move the silence to #off-topic-thats-sometimes-on-topic and talk more about generals here! 24-Dec-18 04:51 AM @qualia I'm just rewatching your stream from last saturday and I realised: Have you ever measured the actual current going through your SNM14? 24-Dec-18 05:07 AM MEOW 24-Dec-18 05:07 AM I have not, actually. 24-Dec-18 05:07 AM I probably should, though! I don't yet trust the picoammeter and I'm not so sure about the microamp mode on my multimeter, but it's probably worth double checking anyways 24-Dec-18 05:09 AM µA mode on the DMM is perfect 24-Dec-18 05:09 AM 'cause your resistor seems a bit high 24-Dec-18 05:09 AM and more corona current results in higher noise immunity 24-Dec-18 05:09 AM should be ~10 µA, 12.5 is max iirc 24-Dec-18 05:53 AM erm 24-Dec-18 05:53 AM an also, you do realise your scope has internal 50 Ohm termination? 24-Dec-18 05:53 AM and you have the termination turned of when you were testing it with your fgen 24-Dec-18 05:53 AM ok, you just found the feature, I'll stop commenting until I've watched the whole thing >.< 24-Dec-18 07:39 AM >:3 24-Dec-18 07:39 AM sometimes i know what i'm doing 24-Dec-18 07:39 AM but only sometimes 24-Dec-18 08:11 AM sometimes I forget not everyone's as stupid as me 24-Dec-18 08:35 AM XDDDD 24-Dec-18 10:57 PM @qualia Did you ever get that RGA up? 25-Dec-18 04:37 AM Merry Xmas \o/ 25-Dec-18 06:53 AM @AdamMcCombs nah, i got dragged aside by neutron detectors. it's still somewhat disassembled with half of its parts in a foil-covered box, need to either try and fire it up with the ceramics as-is or drop the cash on new ones. 25-Dec-18 06:53 AM also wanted to peel apart the electronics box a bit and snag some board pictures, but it is a dense box of magic so i might just.. not, at least until i see if it powers up 25-Dec-18 06:53 AM among other things, i got a monolithic 24VDC power supply i need to wire up for all the miscellaneous control hardware i'm accumulating, and I wanted to make sure it's not too noisy/explosion-prone before i connect it to all of my expensive instrumentation 26-Dec-18 03:01 PM Merry xmas everyone. I hope you all found some new vacuum gear under the tree! 26-Dec-18 04:39 PM Thank you, merry ynachten to you, too! 26-Dec-18 05:25 PM http://sam.zeloof.xyz/high-temperature-superconductor-sputtering-chamber/ 26-Dec-18 10:13 PM Morning! \o/ 27-Dec-18 02:06 AM moin! 27-Dec-18 05:23 PM Say one just bought an untested (but nice looking!) helium compressor for $200-ish. Most common problem would probably be something along the lines of needing to replace seals in the compressor I presume? 27-Dec-18 11:29 PM Moin 27-Dec-18 11:51 PM Morning! \o/ 28-Dec-18 02:57 AM moin! 28-Dec-18 05:14 AM Btw, finally got mentioned in some spanish media. (Article is in spanish, don't bother reading) https://www.microsiervos.com/archivo/hackers/semiconductores-artesanales.html 28-Dec-18 05:32 AM congrats! 28-Dec-18 05:38 AM sounds like "oh look, this guy is from spain and he does cool stuff" :D 28-Dec-18 05:48 AM They have mostly copypasted the email I sent them about the project. But it's something, nonetheless. 28-Dec-18 07:59 AM hi 28-Dec-18 07:59 AM Moin! 28-Dec-18 01:41 PM If anyone needs desiccant for making a home made air dryer or something, let me know... I have pounds of the stuff from opening electronics at work 28-Dec-18 01:41 PM https://i.imgur.com/S6BNwv9.jpg 28-Dec-18 01:41 PM TONS of these 28-Dec-18 01:51 PM Silica Gel? which pore size? xD 28-Dec-18 02:09 PM there's a MIL spec there I'd guess that would have the info. 28-Dec-18 02:52 PM But do you seal them back after opening them? 28-Dec-18 02:52 PM (don't need them in any case, just asking) 28-Dec-18 03:34 PM Huh? These are designed to be used as is. I pulled them out of vacuum sealed packages at work. They would need to be baked and re-activated. 28-Dec-18 03:34 PM But if you were going to make an air dryer you'd open the bags, bake the beads to drive off the moisture, then fill a cylinder with them that you'd pass compressed air through to remove the moisture from the air, so you can have a dry air supply 28-Dec-18 03:44 PM Ahhh!!! 29-Dec-18 12:31 AM Moin 29-Dec-18 12:31 AM Do Not Eat * Ne Pas Avaler * No Comas 29-Dec-18 12:52 AM Morning! 29-Dec-18 02:32 AM moin! 29-Dec-18 07:01 AM anyone experience with an TP*170 turbopump or similiar removing the stators/rotor? 29-Dec-18 07:01 AM With this one somehow the stators are fixed and I can't remove them 29-Dec-18 08:57 AM tries to refrain from joking about statory things and fixed things, but fails somehow 29-Dec-18 09:00 AM giggedy 29-Dec-18 11:39 AM Just saw this on twitter. Priceless! 29-Dec-18 11:39 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/10.1.1.50.9691-DA299.pdf 29-Dec-18 11:39 AM (evolutionary algorithms on reconfigurable silicon (aka FPGA) non clocked discrimination/detection between 1khz and 10khz. 29-Dec-18 11:39 AM It's from '96, no follow up exists. 29-Dec-18 12:57 PM stop joking, start helping! :D 29-Dec-18 12:57 PM jk 29-Dec-18 12:57 PM i really miss a citation function :( 29-Dec-18 01:07 PM ???? 29-Dec-18 01:07 PM It is. Put an @ and a name list will appear. Like @Koelzer this. 29-Dec-18 01:52 PM nono, so I can reference a message from someone directly 29-Dec-18 04:24 PM Ah...oh... 30-Dec-18 12:52 PM Erm, I accidentally just got a residency at ICL? 30-Dec-18 12:52 PM to work on their MALDI TOF Mass Spec 30-Dec-18 12:52 PM and convert it into 'something cool' 30-Dec-18 01:01 PM so this is mine now? 30-Dec-18 01:01 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-80836.png 30-Dec-18 01:02 PM oh, cool! 30-Dec-18 01:07 PM imma strip it all and see if i can put it towards my project 30-Dec-18 01:10 PM what's your project? 30-Dec-18 01:16 PM ohhhhh nice, a MALDI, ❤ 30-Dec-18 01:16 PM love th e pinrciple, want to build one day one too 30-Dec-18 01:22 PM @GigaSquirrel 3D APT 30-Dec-18 01:23 PM APT? 30-Dec-18 01:35 PM Atom probe Tomography 30-Dec-18 01:38 PM uhhh 30-Dec-18 01:46 PM okkayyy hang on 30-Dec-18 01:46 PM you get an atomically sharp tip, you use a HV Pulse through the tip, or more often a laser to evaporate atoms one by one. The atoms flyyyyyy into a Multi Channel Plate and you use a TOF calculation to work out what atom it was. You use a big phat computer to work out where in the tip it was 30-Dec-18 01:46 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/48392784_329005884602992_88149231466761420-E4BEB.png 30-Dec-18 01:46 PM so you can reconstruct a 3d image of the tip with atomic resolution 30-Dec-18 02:25 PM @meowter_space so are you building this at home, or as part of the residency? 30-Dec-18 02:26 PM I'm currently building it at home, might have to do it as part of my residency i guess? shrug 30-Dec-18 02:49 PM Nice! Not my area of expertise at all, but looking forward to seeing how it progresses! Where are you at now in the project scope? 30-Dec-18 02:49 PM I will definitely need to set up a TOF beamline for my system when running in high energy mode 30-Dec-18 02:57 PM early stages. I lack money 30-Dec-18 03:12 PM Yeah, money is the biggest obstacle for me as well. Always seems like it's the major bottleneck for science pursuits 30-Dec-18 03:20 PM Though I have found a lack of money to be one of the most powerful assets to have - it forces you to really think outside the box to get this expensive and high tech stuff done with very limited resources. 30-Dec-18 10:44 PM Last Morning of the year! Hello everyone! \o/ 30-Dec-18 10:44 PM Yep, lack of money is a bummer. 31-Dec-18 12:36 AM moin! 31-Dec-18 01:11 AM Moin 31-Dec-18 03:17 AM I'm wondering @AdamMcCombs how do SEMs cope these days with the vibrations from a TMP? 31-Dec-18 03:18 AM by using balanced ones? 31-Dec-18 03:19 AM You use expensive mag lev ones and isolate them even more 31-Dec-18 04:30 AM oh ok, nice 31-Dec-18 04:30 AM @GigaSquirrel I told you: just brake the vane on the opposite site of the already broken from the turbo I lended you! 31-Dec-18 05:16 AM Edit (coming from machining): Managed to get a 10$ discount for 4 vidicon tubes, for a total of 50$ shipped. They are LI144 Answering to @Koelzer : Because vidicon tubes have a much smaller dot than CRT tubes. 31-Dec-18 05:16 AM ah nice 31-Dec-18 05:16 AM was that "your idea" or did already someone else do that? 31-Dec-18 05:16 AM or similiar 31-Dec-18 05:17 AM I had the idea independently (with a CRT), but later found that someone had done it with a Vidicon tube (for the reasons explained above) 31-Dec-18 05:17 AM let me dig the link 31-Dec-18 05:17 AM (german) http://www.rapp-instruments.de/NewsPage/Vidikon/vidikon.htm 31-Dec-18 05:17 AM Y "only" have to add the X-Y deflection plates. ^^U 31-Dec-18 05:23 AM ohhh yeah, sweet 31-Dec-18 05:23 AM rapp is really incredible 31-Dec-18 05:27 AM Let's see what can I make next year. 31-Dec-18 05:35 AM good luck 31-Dec-18 05:35 AM his setup looks so cool, would like to try it out too, such a cute SEM 31-Dec-18 05:53 AM I love how just everyone knows and loves rapp 31-Dec-18 06:06 AM and wee, new coil on the cap gives way better results 31-Dec-18 06:20 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181231_142638-D83C5.jpg 31-Dec-18 07:50 AM I wish y'all a happy start in the new year! 31-Dec-18 07:50 AM a bit early, isn't it? ^^ 31-Dec-18 07:50 AM better too early then too late xD 31-Dec-18 09:01 AM Happy New Year to everyone as well! 31-Dec-18 09:01 AM @GigaSquirrel great to see you are getting better results with the can crusher now! 31-Dec-18 09:02 AM yep, now I'm happy with it 31-Dec-18 09:02 AM the spark gap has not failed me once so far 31-Dec-18 09:39 AM Zero-Leak year, everyone! \o/ 31-Dec-18 09:39 AM Post a photo of the spark gap electrodes 31-Dec-18 09:39 AM And how many firings have you done. 31-Dec-18 10:39 AM oh yeah, zero-leak would be perfect XD 31-Dec-18 11:03 AM ~20 firings, spark gap looks fine, exept for some surface stuff 31-Dec-18 11:03 AM am no longer at home, so I can't take proper Pictures 31-Dec-18 11:03 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181231_195803_773-63C59.jpg 31-Dec-18 11:03 AM but I have these 31-Dec-18 11:03 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181231_195654_170-11865.jpg 31-Dec-18 11:03 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181231_200152_481-BE7E9.jpg 31-Dec-18 11:14 AM funny, the second picure dosen't even show the actual spark but only a reflexion 31-Dec-18 11:23 AM At those low currents, voltages, and rep rates, the gap will function for a long time before it needs any repolishing of the surface 31-Dec-18 11:46 AM what are the signs of it needing repolishing? 31-Dec-18 11:47 AM Having difficulty firing at the same levels it was before lol 31-Dec-18 11:47 AM ok ^^ 31-Dec-18 11:47 AM idk, from you I expected something like ">1 ns jitter" or similar 31-Dec-18 11:49 AM Well, for fast stuff if you are monitoring it you may see reduced performance 31-Dec-18 11:49 AM For this level, it's not critical lol 31-Dec-18 11:49 AM If they look corroded and gross, doesn't hurt to take them out and clean them whenever either 31-Dec-18 11:50 AM yeah, I figured that 31-Dec-18 01:48 PM Niiice 31-Dec-18 01:48 PM 1h , 12" 31-Dec-18 03:23 PM happy new year to everyone (in my timezone) <3 31-Dec-18 03:25 PM Happy new year (5.5 hours for me to go still) 31-Dec-18 03:38 PM Happy new rotation! 31-Dec-18 05:45 PM happy new year everyone \o/ 01-Jan-19 02:57 AM Joined the server. 01-Jan-19 03:29 AM Welcome! 01-Jan-19 03:50 AM Welcome! Just spotted him on twitter and sent an invite. 01-Jan-19 03:50 AM oh cool, link to their twitter? 01-Jan-19 07:02 AM Hi Everyone, hope you all have a productive new year! 01-Jan-19 07:04 AM Thanks! 01-Jan-19 08:06 AM welcome 01-Jan-19 11:11 AM it's so quiet here 01-Jan-19 11:11 AM everyone hungover? 01-Jan-19 11:51 AM Busy with design work, project write up, house chores lol 01-Jan-19 12:13 PM oh well 01-Jan-19 12:13 PM finally got around to testing my photon counting head 01-Jan-19 12:13 PM after 10 min of cooling down the darkcount is ~90 cps 01-Jan-19 12:13 PM the as-dark-as-I-can-get-it count at least 01-Jan-19 12:13 PM now what to do with it 01-Jan-19 12:13 PM anyone want to get rid of their KDP Crystal? 01-Jan-19 01:12 PM @GigaSquirrel I don't drink coffee...oh wait. Can't be hungover from that either... In any case... BOOOO-New year... 01-Jan-19 01:17 PM No, you can't lick the science, you can shelve the tongue now. 01-Jan-19 01:19 PM naww 02-Jan-19 01:47 AM good morning everyone! 02-Jan-19 01:56 AM good morning :) 02-Jan-19 02:03 AM Morning! \o/ 02-Jan-19 02:12 AM Evening 02-Jan-19 02:12 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190102_021318-9D5E3.jpg 02-Jan-19 02:12 AM I don't know how but someone got some kind of glue on my backscatter electron detector and now it's charging and causing problems 02-Jan-19 02:16 AM oof 02-Jan-19 02:17 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190102_021658-569B3.jpg 02-Jan-19 02:17 AM The beam goes through this spot so when it discarges it causes this probe shift 02-Jan-19 02:17 AM Which on a 400 second scan is a pain 02-Jan-19 02:18 AM is it something that can be dissolved off? 02-Jan-19 02:18 AM Nope solvents will destroy the scintillator 02-Jan-19 02:18 AM I have to scrape it off 02-Jan-19 02:18 AM oh 02-Jan-19 02:18 AM good luck! 02-Jan-19 02:19 AM Yeah I love using razor blades a half a mm away from a sensitive scintillator... 02-Jan-19 02:19 AM SEM roulette 02-Jan-19 02:20 AM Hey I have only scratched one scintillator before 02-Jan-19 02:21 AM It was just a p47 one and had an ito coating so it still worked fine 02-Jan-19 02:23 AM let's hope it's the same with this one 02-Jan-19 02:37 AM Well this one already is scratch but it came that way... 02-Jan-19 02:37 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190102_023827-ACF96.jpg 02-Jan-19 02:41 AM the scintillator looks like metal? 02-Jan-19 02:41 AM Aluminum coated 02-Jan-19 02:41 AM ah 02-Jan-19 02:42 AM Thin enough that bse will go through it 02-Jan-19 02:42 AM It's a plastic scintillator so not great from the don't charge and deflect the beam prespective 02-Jan-19 02:42 AM Back scatter electron 02-Jan-19 02:44 AM and the coating prevents that 02-Jan-19 02:44 AM Yup 02-Jan-19 02:44 AM so in case of a scratch you'd have to recoat it? 02-Jan-19 02:45 AM Paint the section with carbon if it causes a problem 02-Jan-19 02:45 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190102_024536-241E3.jpg 02-Jan-19 02:45 AM It decrases preformance so eventually recoat 02-Jan-19 02:45 AM I have access to a evaporator though 02-Jan-19 02:46 AM hmm 02-Jan-19 02:46 AM is the coating light-tight? 02-Jan-19 02:47 AM Yeah 02-Jan-19 02:47 AM oh 02-Jan-19 02:47 AM Ish 02-Jan-19 02:47 AM Close 02-Jan-19 02:47 AM New ones yes, this one not as much... 02-Jan-19 02:48 AM I have the spec for it somewhere 02-Jan-19 03:08 AM And remounted 02-Jan-19 03:08 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190102_030815-0FEB6.jpg 02-Jan-19 03:09 AM so shiny 02-Jan-19 06:56 AM I'ld like to design a pcb that can be plugged onto the IGM-400 02-Jan-19 06:56 AM What type of display would you prefer for that? 02-Jan-19 06:57 AM hd44780 or 3 digit 7 segment should suffice 02-Jan-19 06:58 AM 1602 sucks, because it's hard to read from a distance 02-Jan-19 06:58 AM 7 segment is nice, however you're very limited in the data to display 02-Jan-19 06:58 AM you don't need to display much 02-Jan-19 06:58 AM pressure and "error" 02-Jan-19 06:58 AM X.Y *10^Z / Err 02-Jan-19 07:00 AM I'ld like to have at least a histogram 02-Jan-19 07:01 AM ah, ok 02-Jan-19 07:01 AM In that case I'd use those small OLEDs 02-Jan-19 07:01 AM which is super helpful to detect events like gas leakes 02-Jan-19 07:01 AM again, too small to be readable from a distance 02-Jan-19 07:02 AM maybe you don't need a bigger display, but better glasses 02-Jan-19 07:04 AM and sometimes you want to read thing not standing right next to the chamber... 02-Jan-19 07:04 AM like from 2-3m away 02-Jan-19 07:13 AM What about a 7 segment for the coarse value and small oled for the histogram? 02-Jan-19 07:13 AM It's not like the pcb is going to be much more expensive for the area. I'll buy one from you, btw. 02-Jan-19 08:14 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-2C6B3.jpg 02-Jan-19 08:14 AM Trying sound card spectroscopy with Windows 10 and it doesn’t seem to be seeing any audio jack input? 02-Jan-19 08:14 AM Check levels 02-Jan-19 08:14 AM And crank them all 02-Jan-19 08:14 AM They’re up to 100 02-Jan-19 08:14 AM Hm 02-Jan-19 08:14 AM Pra has a lot of annoying audio config I can never remember 02-Jan-19 08:15 AM Boost is low but I’ll crank it and see what happens 02-Jan-19 08:15 AM Pra is a pita 02-Jan-19 08:15 AM Yeah try boost 02-Jan-19 08:18 AM No luck 02-Jan-19 08:18 AM Doesn’t seem to be a level/volume thing 02-Jan-19 08:18 AM More that the laptop is not taking anything in from the jack 02-Jan-19 08:18 AM are you sure that you're getting a signal? 02-Jan-19 08:19 AM Quite certain 02-Jan-19 08:19 AM I've had some issues with a broken cable, giving an intermittent fault 02-Jan-19 08:19 AM From the 3He tube and amplifier, works with another laptop 02-Jan-19 08:19 AM oh, ok 02-Jan-19 08:20 AM But I’m trying a new laptop because it’s a bit suspicious with the other one 02-Jan-19 08:20 AM Giving long periods of silence/no signals when left alone 02-Jan-19 08:20 AM Only wants to detect when I’m clicking on the screen it’s weird 02-Jan-19 08:21 AM O.o 02-Jan-19 08:27 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-F7117.jpg 02-Jan-19 08:27 AM That’s from yesterday 02-Jan-19 08:27 AM Note the large periods of silence but the really dense tails on left and right when I was active 02-Jan-19 08:27 AM Running it right now and it seems to have sorted itself out 02-Jan-19 08:27 AM Getting regular pulses 02-Jan-19 08:28 AM are you doing BG runs or do you have a source? 02-Jan-19 08:28 AM Background 02-Jan-19 08:29 AM ah, ok 02-Jan-19 08:29 AM well, good luck with your run! 02-Jan-19 08:29 AM Cheers! 02-Jan-19 06:17 PM Testing the ultimate pressure on my dry scroll vacuum pump to see if it's within spec. Just a pirani gauge on the inlet, but it's taking hours and hours while the pressure steadily drops... 02-Jan-19 07:49 PM How low are you trying to go? You should get close to base pressure pretty quickly 02-Jan-19 08:22 PM Spec says .06mbar ultimate pressure. I reached .085mbar after 5 hours. 02-Jan-19 08:22 PM That sounds a lot like a leak 02-Jan-19 08:23 PM The pump does have 30k hours on it... Might need new seals... 02-Jan-19 08:23 PM Yeah that's possible 02-Jan-19 08:23 PM Or outgassing from contamination 02-Jan-19 08:24 PM I did use it for a vacuum casting apparatus and I think it may has sucked up some holt molten metal one time... Seems like it hasn't quite worked so well since then... 02-Jan-19 08:24 PM *have 02-Jan-19 08:25 PM Yeah that would do it 02-Jan-19 08:25 PM Roughing pumps are terrible industrial vacuum pumps 02-Jan-19 08:26 PM Expensive lesson learned! 02-Jan-19 08:26 PM It's probably fixable 02-Jan-19 08:27 PM Yeah, but I've seen the prices on tip seal kits. It ain't pretty! 02-Jan-19 08:27 PM This is also true... 02-Jan-19 08:27 PM Or it could be a seal on an oring or a bad guage 02-Jan-19 08:29 PM I used the gauge to test the pump on my SEM and it read exactly per spec for the pump 02-Jan-19 08:29 PM Hm... 02-Jan-19 08:29 PM @AdamMcCombs, going to hardware happy hour tomorrow? 02-Jan-19 08:29 PM Don't know yet 02-Jan-19 08:33 PM I'm planning on going. It's in Redmond. 03-Jan-19 12:09 AM Morning! \o/ 03-Jan-19 01:22 AM Moin! 03-Jan-19 02:44 AM Moinsen! 03-Jan-19 02:44 AM what? .06 specced and 0.85 reached? that sounds really good to me, especially if it has been used a while 03-Jan-19 02:44 AM and most gauges aren't reallly that precise, are they? 03-Jan-19 02:52 AM 85 vs .06, that orders of magnitude off... 03-Jan-19 02:54 AM sorry, miswrote, I kinda read 0.06 specced and 0.085 measured above, or is it just too early for me? 03-Jan-19 02:55 AM no, you're right, dirac 03-Jan-19 02:55 AM Oh 03-Jan-19 02:55 AM I wish my pump would come so near to the specs XD 03-Jan-19 02:56 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_20190103-025532-A0C8E.png 03-Jan-19 02:56 AM It put the decimal on the line before 03-Jan-19 02:56 AM oh, thats evil 03-Jan-19 02:56 AM So I read it as 85 instead of .085... 03-Jan-19 02:56 AM ahh 03-Jan-19 02:57 AM Ok yeah no leak 03-Jan-19 02:57 AM Some one tag pyguy when they are awake... 03-Jan-19 02:58 AM well, they're online 03-Jan-19 02:58 AM @piGuy we fixed your pump 03-Jan-19 02:59 AM haha 03-Jan-19 02:59 AM that makes 200 bucks (industry be like) 03-Jan-19 03:00 AM I love fixes like this 03-Jan-19 03:00 AM They are cheap 03-Jan-19 03:00 AM I have a 15 email long thread of troubleshooting a TEM with like 5 phds 03-Jan-19 03:00 AM They were saying that the high voltage light wasn't coming on 03-Jan-19 03:00 AM So they get lead through checking all the safety systems and what not 03-Jan-19 03:00 AM We check the lens PS switch to see if they hear the relay click when they flip it. No click. 03-Jan-19 03:00 AM They then get asked to check what vacuum pressure was on the computer and if the vac ok lights were on. Nada. 03-Jan-19 03:00 AM As in the computer wasn't on 03-Jan-19 03:00 AM They then get asked if the roughing pump and water chiller are on. Also nada. 03-Jan-19 03:04 AM it was not plugged in? 03-Jan-19 03:05 AM THE KEY WAS OFF 03-Jan-19 03:05 AM 15 emails 03-Jan-19 03:05 AM hahahahahaha 03-Jan-19 03:05 AM "oh that's why the big instrument was silent" 03-Jan-19 03:06 AM >.< 03-Jan-19 03:07 AM if they hadn't just paid an ungodly amount of money and time from like 4 different companies and 2 departments it would be funny 03-Jan-19 03:09 AM XD 03-Jan-19 03:09 AM nice 03-Jan-19 03:09 AM I mean at least your happy afterwards, that its running again 03-Jan-19 03:11 AM And it's not like these people hadn't worked with scopes before either... 03-Jan-19 03:14 AM actually I once had the same with an old HPLC, we had to re-setup. Was just half a day, but the on/off switch was somehow hidden under some "bulge" 03-Jan-19 03:15 AM well, everyone's got their ups and downs in... cognitive ability 03-Jan-19 03:26 AM definitive... cries after the hornet I killed 03-Jan-19 03:27 AM at least you're a true member of the DGS now 03-Jan-19 03:33 AM haha, but didn't try my second yet, at first I must revive my TMP controller... 03-Jan-19 03:35 AM any success yesterday after I left? 03-Jan-19 03:38 AM I left at the same time XD will exchange OPamps later 03-Jan-19 03:43 AM Wait even deader hornet? 03-Jan-19 03:44 AM 1.something kV at the output and no longer responding to anything - dead 03-Jan-19 03:44 AM Uh 03-Jan-19 03:44 AM How? 03-Jan-19 03:45 AM special talents 03-Jan-19 03:45 AM Yeah that's a given 03-Jan-19 03:45 AM *looks over to @Koelzer * 03-Jan-19 03:45 AM dunno, he figures he connected it wrong 03-Jan-19 03:45 AM I tested it successfully before sending it to him 03-Jan-19 03:45 AM but our postal service is quite rough of many packages 03-Jan-19 03:49 AM Don't talk to me about rough postal service I have a sputter coater in the mail right now 03-Jan-19 03:49 AM good luck! 03-Jan-19 03:50 AM I got it shipped for 170... 03-Jan-19 03:50 AM oh wow 03-Jan-19 03:51 AM I didn't ask if it had the gold in it, I didn't want to tip the seller off 03-Jan-19 04:01 AM so you might have gotten >$170 worth in gold and a free sputter coater with it? 03-Jan-19 04:05 AM If it's a new piece of gold then a lot closer to 500... 03-Jan-19 04:06 AM nice 03-Jan-19 04:07 AM ts ts ts 03-Jan-19 04:08 AM Yeah common dirac 03-Jan-19 04:08 AM ts;dr I crapped the circuit for the hornet 03-Jan-19 05:58 AM Can I has the dead Hornet? 03-Jan-19 05:59 AM asa I tried my new one :D 03-Jan-19 06:06 AM ¿? 03-Jan-19 06:22 AM as soon as I tried my second hornet if it works 03-Jan-19 06:22 AM not sure whats bad with it 03-Jan-19 06:22 AM maybe need to exchange the caps, because the now dead one has good caps in it xD 03-Jan-19 06:31 AM I actually only want the KF16 connector. 03-Jan-19 06:31 AM (feedthrough) 03-Jan-19 06:31 AM Ahh, you mean as soon as you try, (tried is past tense, and was getting me confused) 03-Jan-19 06:36 AM it would be very hard to do anything with it 03-Jan-19 06:36 AM as it is long and has a small opening 03-Jan-19 06:36 AM what is the overall output voltage range of the hornet? 03-Jan-19 06:36 AM 0-10V 03-Jan-19 06:36 AM okay 03-Jan-19 06:36 AM is there any offset on analog ground? 03-Jan-19 06:37 AM http://www.fusor.net/board/viewtopic.php?f=10&t=12165&sid=28d441eaa7c0332cf6d09b377e1c7a68 03-Jan-19 06:38 AM We acknowledged that, but guessed that a special tool can be made to spot weld on the inside, and have a perfectly usable electrical feedthrough. 03-Jan-19 06:38 AM sure, worth a shot 03-Jan-19 06:39 AM Or a more mechanical mechanism like crimping 03-Jan-19 06:40 AM Crimping on narrow places seems a lot less doable, in my head, as it usually requires a considerable amount of force. 03-Jan-19 06:41 AM I'm thinking of a certain pair of pliers I have made for stuff like that 03-Jan-19 06:41 AM mmmmkay. 03-Jan-19 06:41 AM maybe cut them open, do whatever you want inside and weld it shut again 03-Jan-19 06:41 AM Thats a no-no 03-Jan-19 06:41 AM the inside weld is going to be crappy, if nothing else. 03-Jan-19 06:42 AM ah, sure, outside welding is bad because of virtual leaks 03-Jan-19 06:42 AM altough welding it to a plate (a KF plate) might work. as you can weld the inside flush. Hmmmm 03-Jan-19 06:43 AM Push pin connection? 03-Jan-19 06:43 AM That can work too. I guess. 03-Jan-19 06:43 AM Like an inverse banana plug 03-Jan-19 06:43 AM btw, these gauges have two 24bit high precision ADCs in it 03-Jan-19 06:43 AM Female banana plug, you mean? XDDDDDDDDDDDDD 03-Jan-19 06:43 AM each worth $8 03-Jan-19 06:43 AM Interesting! 03-Jan-19 06:44 AM I cant believe they don't output digital data 03-Jan-19 06:44 AM No 03-Jan-19 06:44 AM yeah, its totally crazy 03-Jan-19 06:44 AM You need something with a bit of spring 03-Jan-19 06:45 AM the IG current is digitized, pushed through a LUT, into an DAC giving 0-10V, which is digitized again in the controller hardware 03-Jan-19 06:46 AM and there is no RS485 output? 03-Jan-19 06:46 AM what are those CG1 and CG2 for? 03-Jan-19 06:47 AM there is some RD485 chip inside, but I havent probed that yet 03-Jan-19 06:48 AM @niklas are you going to design the board so it can be directly welded to a DB9 connector? 03-Jan-19 06:48 AM CG1 and 2 appear to be for external piranis 03-Jan-19 06:48 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20141114_232936-EC28B.png 03-Jan-19 06:48 AM yes 03-Jan-19 06:48 AM NIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIICE 03-Jan-19 06:48 AM do you accept preorders of pcb's? 03-Jan-19 06:48 AM XDDD 03-Jan-19 06:49 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_from_2019-01-03_15-49-01-23D23.png 03-Jan-19 06:49 AM something like this 03-Jan-19 06:49 AM ewwwwwwww 03-Jan-19 06:49 AM I know it's more resistant to mechanical stress....but...the straight welded DB9 looks nicer. 03-Jan-19 06:49 AM even though I hate this practise, I tried to use as many modules from aliexpress as possible 03-Jan-19 06:49 AM Through hole is more manufacrable than hacked edge connector... 03-Jan-19 06:50 AM would also be interested 03-Jan-19 06:50 AM but hacked edge connector is truly hacker-ish. 03-Jan-19 06:50 AM yeah but this is a multi-pcb design with the DB9 in between the mainboard and the frontplate pcb 03-Jan-19 06:51 AM Ah!, in that case I have no complaints then. 03-Jan-19 06:51 AM Are you also going to put both Oled and 7 segment? 03-Jan-19 06:51 AM no 03-Jan-19 06:51 AM single 1.8" tft 03-Jan-19 06:51 AM ooook 03-Jan-19 06:52 AM https://de.aliexpress.com/item/1PCS-1-8-inch-TFT-touch-LCD-Module-LCD-Screen-Module-SPI-serial-51-drivers-4/32817839166.html 03-Jan-19 06:52 AM this one 03-Jan-19 06:52 AM That's a good price. 03-Jan-19 06:53 AM you can already start ordering 03-Jan-19 06:53 AM you also need a bluepill 03-Jan-19 06:53 AM In the end we might end needing to make a PCB selling chat/list/page/something. 03-Jan-19 06:53 AM What is a bluepill? 03-Jan-19 06:53 AM an arduino small form factor ? 03-Jan-19 06:54 AM basically 03-Jan-19 06:56 AM I think I'll ask someone to buy two and program one for me. I don't have anything arduino. 03-Jan-19 06:56 AM It's not that hard... 03-Jan-19 06:56 AM How much do you think you will charge for the PCB's? (guesstimate, I mean) 03-Jan-19 06:59 AM the pcbs will probably be <1€ for both, the components ~10€ 03-Jan-19 07:00 AM Well, count me in for one set. ^^ 03-Jan-19 07:00 AM If I end designing a 3D printed case, I'll post it somewhere for people to download. 03-Jan-19 07:02 AM A case is not neccesary 03-Jan-19 07:03 AM Mkay. 03-Jan-19 09:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_from_2019-01-03_18-02-02-F13B2.png 03-Jan-19 09:09 AM has anyone seen the hornet logo on the interwebs? 03-Jan-19 09:56 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_from_2019-01-03_18-56-08-BFB5F.png 03-Jan-19 10:31 AM okay yellow solder mask with black silkscreen is actually kinda expensive, 70€ for 25 sets shipped 03-Jan-19 12:07 PM Oh....shame. Why only two screws on top? 03-Jan-19 12:07 PM Looks gorgeous tho. 03-Jan-19 12:16 PM wow looks cool 03-Jan-19 10:15 PM Hey everyone! First post. I have a TEM that I bought from Southern Conneticut Univ - Phillips EM-400. I live a bit north of Los Angeles - actually in the middle of where those fires burned in Thousand Oaks. I have been able to get one moving quote; company would pallet and then use air-ride truck to move. I was surprised they didn't feel necessary to crate - about 3k. If anyone can suggest either local companies in Conneticut, or National, I would be deeply appreciative. Im guessing Adam will know. :). I have experience moving a SEM, that was much lighter and was only 350 miles from my house. The people at the University seem to feel I need to hire a company specializing in moving TEM's - I hope I didn't naively make a financially large mistake. 03-Jan-19 10:33 PM @AdamMcCombs 03-Jan-19 10:45 PM Btw, welcome, @barkingsheltie 03-Jan-19 10:45 PM Morning! \o/ 04-Jan-19 01:25 AM moin! 04-Jan-19 06:41 AM @barkingsheltie Averaging everything out, I have seen more damage during the crating process than just shipping somethin stretched wrapped and prepared really well. You really need someone who know a TEM is is really good at being very carful and familiar with sensitive vacuum systems and electronics to properly prepare it. This is what JEOL columns I ship normally look like during transit. 04-Jan-19 06:41 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/UlWPxM-tqXyiBZj1QUhI-xXjRwgVJZWwnT5ftxlQI--975A0.png 04-Jan-19 06:41 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/cimHJzfpdhyNscFb05_Q-_JaiQmbvrwmCmxzLyrMiq-DB584.png 04-Jan-19 06:53 AM The 400 series uses the integrated lifting jacks to get it on and off the ground. You don't always find them with the instrument though. Butch at SIS can probably supply some if you need any. 04-Jan-19 06:53 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/42020setup201-52B1D.png 04-Jan-19 08:14 AM Met a guy doing metal 3D printing who lives just a few blocks from me. He also told me @AdamMcCombs is a bona fide genius. 04-Jan-19 08:33 AM XDDDD, yep, we sort of knew the last part. 04-Jan-19 10:31 AM btw @Nixie how do you gonna protect the cathode of your vidicon when using it as a electron source? 04-Jan-19 11:23 AM You mean the filament? 04-Jan-19 11:49 AM yes 04-Jan-19 11:58 AM protect it from what? 04-Jan-19 12:28 PM air 04-Jan-19 12:29 PM I guess an isolating valve between the chamber and electron gun would make sense 04-Jan-19 12:29 PM you wouldn't want to vent the gun often anyways, due to high surface 04-Jan-19 12:30 PM It's fine if it's exposed to air as long as it's not hot 04-Jan-19 12:30 PM It's not that bad. You can run as low as -4, but you get way better filament life at -5 04-Jan-19 12:30 PM A lot of SEMs vent the gun during sample exchange as well 04-Jan-19 12:32 PM yeah but sems have bare tungsten 04-Jan-19 12:32 PM vidicons use bariumoxide which is hydrophilic 04-Jan-19 12:32 PM they usually die within ~1h beeing exposed to air 04-Jan-19 12:33 PM Nixi and I talked about this earlier and I remember him talking about tungsten, but I could be wrong 04-Jan-19 12:33 PM *am probably 04-Jan-19 12:34 PM I made this experience earlier myself with a crt 04-Jan-19 12:34 PM also this excellent site talks about this problem : http://www.rapp-instruments.de/foto/Raster/REM/Rem.htm 04-Jan-19 12:34 PM (use https://www.deepl.com ) 04-Jan-19 12:34 PM http://www.rapp-instruments.de/NewsPage/Vidikon/vidikon.htm 04-Jan-19 01:07 PM I wonder how well those micro crts from old video cameras would work 04-Jan-19 01:07 PM https://youtu.be/X0Lt9f1ykxc?t=238 04-Jan-19 01:07 PM like these 04-Jan-19 01:07 PM you can get them super cheap off ebay 04-Jan-19 01:07 PM https://www.ebay.de/itm/Alte-JVC-Videokamera/223292110522 04-Jan-19 01:07 PM and they already work with 5-7kV 04-Jan-19 01:11 PM Sorry for the late reply, I had to do chores. I plan to use argon/helium to protect it during tests. I don't mind running over a few vidicons if I need to during testing. The final step would be to actually put the innards in a special tube and make the filament interchangeable, like electron microscopes do. Also, would like to try to just dissolve the barium oxide and see what the bare filament does. 04-Jan-19 01:11 PM I think there are more vidicons than those crt avaliables, and in any case, I would like to end manufacturing the whole thing myself. (Supposing it works, of course) 04-Jan-19 01:11 PM Tose micro crts only make it more difficult to work with, as they are so damn small. 04-Jan-19 01:11 PM And there is no need to make this that size. As in any case, the miniature DP will need a minimal size to work properly. 04-Jan-19 01:11 PM Also, it's probable that the vidicon can be run at more than 1kv anyways. In a past chat with either @GigaSquirrel and/or @Applied_Ion we discussed that 2/3kv given the geometries and distances between components of the vidicon. 04-Jan-19 01:32 PM so you just apply an external acceleration voltage? 04-Jan-19 01:34 PM oh, nice - didn't know thomas made some efforts on those topics... but no surprise either 04-Jan-19 01:36 PM this is actually pretty old 04-Jan-19 01:36 PM I think I have seen this years ago already 04-Jan-19 01:38 PM yeah, i know - haven't visited his site in a long time. and back when i did my interests were somewhat different 04-Jan-19 01:38 PM hmm, I still have this stupid idea of building an open microfocus x-ra ytube myself 04-Jan-19 01:38 PM I wonder if I could use one of those micro crts 04-Jan-19 01:38 PM vidicons probably have too low beam current for this 04-Jan-19 01:38 PM but one of those crts... 04-Jan-19 01:53 PM wow how is vacuum equipment on aliexpress so cheap?? 04-Jan-19 01:53 PM last time I did stuff with vacuum, I bought everything from German sellers and payed a fortune 04-Jan-19 02:46 PM Its been like that for at least a year and a half, when I started. 04-Jan-19 02:46 PM @niklas what do you mean by an "external acceleration voltage"? 04-Jan-19 02:49 PM having an external anode that is biased with eg -30kV 04-Jan-19 03:32 PM I didn't find aliexpress particularly cheap, for the month of delivery time you just have to search a bit longer for a bargain in german ebay, imho 04-Jan-19 03:52 PM I still very badly want this vacuum assembly: https://www.ebay.de/itm/Phoenix-X-ray-Nano-Focus-XS160T000F-126907-and-Black-Tube-extra/163399412057 04-Jan-19 03:52 PM I could get it basically for free ($100) but shipping is $500 to Germany... 04-Jan-19 03:52 PM also, kinda feels bad to ship this thing to Germany, because well, that's where it came from 04-Jan-19 03:58 PM what holds you back from trying this nano electronbeam hitting a tungsten target approach? 04-Jan-19 04:01 PM I don't have a tungsten target 04-Jan-19 04:01 PM I would need a beryllium or diamond window, coated with ~100µm of tungsten 04-Jan-19 04:01 PM plus there is probably a reason why the phoenix head has three magnetic focusing coils... 04-Jan-19 04:01 PM btw @Applied_Ion I found this on ebay which is the HV source for the head: https://www.ebay.com/itm/Phoenix-x-ray-systems-FRIE0001-10105-Friedemann-180KV-x-ray-generator-/171831360756 04-Jan-19 04:01 PM too mee, it looks like as if there is only a single conductor inside the isolator 04-Jan-19 04:01 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_from_2019-01-05_01-04-40-EB0A2.png 04-Jan-19 04:01 PM still this slide highly suggests the filament is powered the way you supposed 04-Jan-19 04:01 PM how could this work? 04-Jan-19 04:01 PM internal trabsformer for heating? 04-Jan-19 04:21 PM Hmmm, I'll have to look into it more closely 04-Jan-19 04:28 PM Spellman has a similar style supply, looking through the manual. It's tough to tell from the pics, but the ebay one may use a coaxial hv/filament plug like we use for our accelerator gun to provide hv and filament power from a single port 04-Jan-19 04:28 PM In the manual for the Spellman one it says there are floating AC and grounded DC filament options 04-Jan-19 04:40 PM Unless there are plugs for the filament seperate on the tube, and stuff is still floating in the supply. It's hard to say. Though the grounded DC filament is an interesting prospect 04-Jan-19 04:40 PM Wait a second. The grounded filament uses a positive polarity supply, the floating AC one uses negative. So it greatly determines how the tube is actually configured 04-Jan-19 04:40 PM Grounded DC makes sense for a positive biased supply. Often times though you see a negative supply with the heater floating, since it allows the anode to be at ground, which is attached to the case. Positive is less common due to more isolation requirements on the gun side. 04-Jan-19 04:40 PM Two options in this case to make your own, each with tradeoff. Negative supply requires isolation transformer, but anode is at ground making gun easier to build. Positive supply eliminates isolation transformer, but requires floating anode increasing insulation needed in the gun, making it a bit more tricky 04-Jan-19 04:53 PM ohhhhh, slightly off-topic question on X-Ray supplies - i've got a short piece of high voltage wire with a 3-pin HV plug and a matching socket. 04-Jan-19 04:53 PM Plug looks like this: https://www.roentgen-boehnke.de/responsive/wordpress/wp-content/uploads/2017/01/Kopieren_von_IMG_8642.jpg 04-Jan-19 04:53 PM i can't for the love of * find a picture of the socket... but does anyone know where to find datasheets or similar about this type of plug? 04-Jan-19 04:53 PM 'cause maybe the socket is somewhat vacuum-tight... and i could use it as high-voltage feedthrough... 04-Jan-19 04:58 PM That looks in real rough shape, either really dirty or charred, it probably won't get up to very high voltage before surface tracking occurs 04-Jan-19 05:01 PM that picture was only as a reference, somwhere from the internet. my plug and socket look clean, slightly greased and have shiny contacts 04-Jan-19 05:01 PM according to the page the plug in the image had some kind of arcing accident 04-Jan-19 05:01 PM but it looks like the one i have, so i used that 04-Jan-19 05:01 PM ha, found a cleaner one: 04-Jan-19 05:01 PM http://www.essex-x-ray.com/essex_medical.html 04-Jan-19 05:28 PM That's looks like a standard hv plug that I can't remember the name of right now 04-Jan-19 05:36 PM if you remember the name, just let me know. it's not that important, just something that came to my mind when reading about floating AC heated X-Ray tubes 05-Jan-19 12:09 AM Moin! 05-Jan-19 12:09 AM Evening! 05-Jan-19 01:51 AM Morning! \o/ 05-Jan-19 04:50 AM @Pan Da good chance the socket would be pretty well sealed because both ends are going to be in oil, either the xray head or hv tank. But probably not so good for high to UHV range, because it looks like plastic. Cheapest way to get one is probably to buy a used xray head. There are also a lot of DIY options for feedthrus in the 1e-6 or even lower range because you can use epoxy or rubber seal. 05-Jan-19 05:13 AM BTW, what you need in a HV feedthru depends a lot on what you are doing. As someone who started interested in HV, then moved to vacuum, this took me a while to appreciate. The air side of the feedthru, and the thru conductor and insulation are determined by the current and voltage, so are only affected by the vacuum side use insofar as it affects the plasma impedance (and so current/voltage combination). You have to worry about arcing across the insulator on the air side, which may lead to the classic big flanged HV bushing. And you have to worry about the dielectric strength of the insulator inside the feedthru (enough thickness to not break down). A first point is that you cannot have much in the way of high voltage until you reach high vacuum, < 1e-4 Torr or so. You just get a glow discharge. Fusors typically operate in the 5-15 mTorr range, and can stand off many KV. Industrial plasmas are typically in the 50-250 mTorr range, with operating voltage 300-600V (tho perhaps 1kV to start). 05-Jan-19 05:27 AM When you have plasma, then the concern is with getting the discharge where your want it, and also having any exposed insulation withstand the plasma bombardment and chemical activity from reactive process gas. Getting the discharge to happen in the right place is a matter of making the desired discharge the path of least resistance. Since the whole interior of the chamber is going to be plasma (which is conductive) there is not any true insulation. The fusor uses a long internal insulator (longer than chamber radius) so that the discharge happens from the center to wall, not along the feed insulator. You do not actually need a long internal insulator in many uses. A common trick in industrial plasma is to use a gap that is too small for a glow discharge to form (shorter than the cathode dark space). And at really high vacuum you also do not need any separation to speak of. Eg mm in an xray tube or vacuum capacitor. 05-Jan-19 05:27 AM "Where there is an arc, there is no vacuum, and where there is vacuum there is no arc." 05-Jan-19 05:27 AM Something you can do in a DIY feedthru is seal the insulating cable into the feedthru using eg. silicone RTV. CRT displays operated fine at 20 KV without any big flanged bushing on the air side, they used rubber dielectric. No direct exposure of the full voltage to air. 05-Jan-19 06:17 AM With hollow cathode and magnetron plasma sources, these enable a discharge in the correct location at a lower voltage than would be possible with a plain electrode at that pressure. With many hollow cathodes the pressure is also higher in the discharge zone because of the gas feed thru the cathode. These factors minimize discharge along undesirable paths. 05-Jan-19 06:27 AM In my hollow cathode setup, the voltage is across the fat aluminum cylinders (negative) and the heatsink (ground), isolated only by the thin white silicone insulator. There is little discharge between the two under typical pressure of 50-150 mTorr and 300-500V. Probably there would be long term durability issues with exposure of silicone and Teflon to the reactive plasma, but the jet is to the right, away from these materials. BTW, the white plate insulator is cut from a decorative stone tile. Stone is a very cheap ceramic, some types machineable with metal tools. I had to use diamond saw blade for this. 05-Jan-19 06:27 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181123_155117038-2A107.jpg 05-Jan-19 06:27 AM I had much more trouble with insulation at the center gas feed because there is higher pressure there and exposure to the intense inner plasma. 05-Jan-19 06:38 AM Currently I have a ceramic tube which is cemented into a counterbore in the aluminum heat spreader using refractory cement (colloidal silica and zircon). Also, the heatsink is relieved in this area to give a longer discharge path. 05-Jan-19 06:38 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180916_201157493_HDR-49FE6.jpg 05-Jan-19 06:38 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181123_154956605-DBF0B.jpg 05-Jan-19 06:58 AM The issue was probably more dielectric breakdown across the gap, promoted by dirt, and also the intense plasma and heat deteriorated the mica and polymer insulation I was trying to use. I was also struggling with finding a compatible thermal interface gap filler, tried various things that did not work. Sodium silicate foams up under heat, and is not a good insulator. Grafoil and pyrolytic graphite are good thermal interface, but are conductive; I used with mica, but these also seem to promote discharges at the exposed edge (especially Grafoil, which has a complex microstructure). With the alumina tube, it would probably work to use mica or Kapton with silicone thermal grease, but I went for a silicone thermal interface used for eg. mounting transistors on a heatsink. This particular material was also rated for outgassing, tho I didn't evaluate the actual number. This was expensive in sheet form, $100 for 8x10 inch, but I was tired of messing with this particular problem. The bolts are grounded also, and have Belleville spring washers to maintain a moderate compression under thermal cycling. I didn't want to torque them down too much because the stone is not very strong. 05-Jan-19 07:09 AM The feed gas tubes are Teflon with short Viton coupling to the copper feedthru. There is only a relatively high pressure in the tubing, perhaps 1-2 Torr at this point (I don't really know). Pressure at the MFC output is 10 Torr or more. The feedthru for the water and process gas is copper tube with JB weld seal to hole drilled in the SS KF50 blank. The coax feedthrus are Pasternak hermetic bulkhead mount BNC connectors. I picked these up on eBay for $12 each, and list price is only $25 IIRC. Really I should be using a higher voltage connector like MHV/SHV, but they are more obscure, and I don't have any cables, etc. 05-Jan-19 07:09 AM https://www.pasternack.com/bnc-female-bnc-female-straight-adapter-pe9093-p.aspx? 05-Jan-19 07:09 AM If you can use any part that is not specifically sold into the vacuum market, then you will save a lot of money. 05-Jan-19 07:19 AM I have made electrical feedthrus using Loctite/Hysol EA 1C (supposedly the same as Torr-seal), but have had to backfill the outside with flowable silicone RTV to get a good seal. Perhaps this is because I vacuum degassed it? I don't know. I do not degass JB weld, and have so far always gotten a seal the first time. But JB weld is metal filled, so not a great insulator (tho not reliably conductive either). 05-Jan-19 07:19 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190105_101210699-A40B2.jpg 05-Jan-19 07:19 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20171116_180159872-03969.jpg 05-Jan-19 07:19 AM Oh, in the cold cathode picture 3 back you can see I patch I glued on the inside of the chamber using Hysol. The patch had to go on the inside because it is a bolt hole (I drilled too deep). This patch worked fine. Don't recall whether I degassed Hysol that time or not. 05-Jan-19 07:19 AM I stripped off the outer PVC insulation on the coax under the theory that it would outgas. The inner insulation is polyethylene, which is not so bad. This transitions to Teflon insulated wire, which is as inert and heat resistant as a polymer gets. 05-Jan-19 07:19 AM In the UHV setups I have seen pictures of, it looks like they are using magnet wire, or sometimes bare wire with ceramic sleeves where needed. 05-Jan-19 07:19 AM At UHV, as well as outgassing from the insulation, stranded wire may have pseudo-leak problems with gases trapped inside the insulation jacket among the strands. I don't have any UHV experience. 05-Jan-19 07:19 AM Drawing of hollow cathode 05-Jan-19 07:19 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190105_103957134-ED98C.jpg 05-Jan-19 08:06 AM Excellent writeup! I mainly want to learn to make feedthroughs so I can manufacture everything in-house and don't have to depend on ebay, as I don't hve access to deals the like US and GE have. 05-Jan-19 10:29 AM wrt controlling the plasma, an example in the hollow cathode. The plasma does not know which way is "forward", and may form going backward in the gas feed where the pressure is high, especially if the main discharge stops for whatever reason. Adding the front keeper anode helped with this, tho I now seem to be able to do without it to some degree. What also helped was adding extra length to the Teflon feed tubes. 05-Jan-19 10:29 AM I tried to control the back discharge by making the rear hole smaller, but this was not enough. 05-Jan-19 11:13 AM laughs internally at the 5yo joke 05-Jan-19 02:02 PM Joined the server. 05-Jan-19 02:02 PM so, I am into vacuum stuffs (I have a turbomolecular in a packing box somewhere) but also high pressure systems.. current project is hacking a modern diesel engine to an opensource ECU.. I have a flow bench in my kitchen of the HP fuel side, getting over 10k psi from a hand drill (capable over ~20k) .. I am currently working on the pressure regulation and PID 05-Jan-19 02:02 PM but yeah, was just linked to this server, so joining up 05-Jan-19 02:10 PM cool, welcome! 05-Jan-19 02:10 PM feel free to post pics of your projects 05-Jan-19 02:10 PM We like project pics here 05-Jan-19 02:15 PM posted over in show and tell 05-Jan-19 02:15 PM I'm a watchmaking student, so I am interested in e-beam lithography to etch out tiny gears and related parts 05-Jan-19 02:15 PM also, into amateur chemistry, and have some ideas on making a mass spec 05-Jan-19 02:15 PM looked a bit into the photoelectric effect of generating e-beams, over the heated tungsten wire 05-Jan-19 02:15 PM .. about all I am into, thus far 05-Jan-19 02:22 PM Sam zelof is working on some other scanning probe stuff not using electrons... If you don't need the crazy resolution of ebeam then no need for vacuum 05-Jan-19 02:22 PM I think I've seen all of his vids 05-Jan-19 02:23 PM Not there yet... 05-Jan-19 02:24 PM he has DLP vids and such.. I thought he did an e-beam vid recently, too? 05-Jan-19 02:24 PM Dlp is great for larger stuff as well 05-Jan-19 02:24 PM Yeah, there some new laser stuff happening 05-Jan-19 02:24 PM especially if you can focus down small 05-Jan-19 02:24 PM I also have 8 or so AG-LS25 stages (plus a controller) 05-Jan-19 02:24 PM just as a small background of some stuffs I have already 05-Jan-19 02:25 PM Those are those nice piezo ones right? 05-Jan-19 02:26 PM yeah 05-Jan-19 02:26 PM I may have a shot of one taken apart, it's a single piezo on a compliant (stainless?) mechanism that just nudges it around 05-Jan-19 02:26 PM Yeah. Looked at them for something else but they didn't have the life span needed 05-Jan-19 02:26 PM single arm 05-Jan-19 02:28 PM Anyways, photo emission 05-Jan-19 02:28 PM That's a fun thing to use for ebeam stuff 05-Jan-19 02:30 PM AG-LS25 05-Jan-19 02:30 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_4304-E349D.jpg 05-Jan-19 02:30 PM one single piezo on a compliant nudger 05-Jan-19 02:30 PM also has limit "switch" 05-Jan-19 02:30 PM which is the black part (the cover, which has basically a bus bar) 05-Jan-19 02:34 PM Do you have the micro interferometers to use on it? 05-Jan-19 02:37 PM no, I only recently looked into .. essentialy micro DRO 05-Jan-19 02:37 PM I have one idea I want to hack together, will likely be for larger scale things first, like a lathe or mill 05-Jan-19 02:37 PM also, it was an ebay purchase 05-Jan-19 02:37 PM nice bundle for the price 05-Jan-19 02:53 PM @Noxz welcome! I think you are by far the only one who has presented him/her/it self. I might bother you about the watchmaking. 05-Jan-19 02:53 PM hah, Hi! 05-Jan-19 02:53 PM I am a first year student, second quarter just started 05-Jan-19 02:53 PM (2 year trade school, only about 5 exist in the US anymore) 05-Jan-19 02:55 PM Way more than me, I am just amateurish, but love mechanics all the way. 05-Jan-19 02:55 PM I hear ya 05-Jan-19 02:55 PM (from small to big, i mean) 05-Jan-19 02:55 PM I was a bicycle mechanic for several years 05-Jan-19 02:55 PM About the e beam litography, you mean ion etching, right? 05-Jan-19 02:56 PM my reference? no, exposure 05-Jan-19 02:56 PM Omg...we have bicyclerepairman here! (Monthy phyton joke) 05-Jan-19 02:56 PM could be wet etching, but also interested in e-beam -> Molecular-beam epitaxy 05-Jan-19 02:57 PM Thats more of adam's zone. 05-Jan-19 02:57 PM I am only into wet etching. 05-Jan-19 03:16 PM I am also interested in Langmuir Films 05-Jan-19 03:24 PM slowly fades into the background 05-Jan-19 03:24 PM Eh...I think this is on the level of everyone else. 06-Jan-19 06:25 AM hm, paraffin oil is fairly cheap and a good electrical isolator, but I don't know too much about oils 06-Jan-19 06:25 AM could I just add it to an unknown (non-PCB) oil in a leaking capacitor? 06-Jan-19 06:26 AM after cooking down in vacuum, probably 06-Jan-19 06:26 AM I know there are some oils you should not mix, but I think it was synthetic and natural? 06-Jan-19 06:26 AM drying it is a given, I'm just not sure about maybe some chemical incompatibility 06-Jan-19 06:30 AM i would clean the cap and then refill with new oil 06-Jan-19 06:30 AM mixing is never a good idea 06-Jan-19 06:30 AM 'cause you shouldn't mix synthetic and natural oils... and even some of the sames don't mix well... 06-Jan-19 06:31 AM Also degas it 06-Jan-19 06:32 AM degas the oily juice? 06-Jan-19 06:33 AM a clear case of "lets put this in storage until I am willing to deal with it" 06-Jan-19 06:33 AM I can't think of that they would use natural oil in there 06-Jan-19 06:33 AM I would just mix it 06-Jan-19 06:33 AM xD 06-Jan-19 06:33 AM did you find the origin of the leak btw? 06-Jan-19 06:34 AM our big pulse caps have castor oil... 06-Jan-19 06:34 AM well, our big ones have castor oil 06-Jan-19 06:34 AM ah well 06-Jan-19 06:34 AM nope, no leak found 06-Jan-19 06:34 AM https://i.kym-cdn.com/photos/images/newsfeed/000/328/161/576.gif 06-Jan-19 06:34 AM found it! 06-Jan-19 06:35 AM look at the leek in the sink! 06-Jan-19 06:35 AM xD 06-Jan-19 06:35 AM look at it drippin'! 06-Jan-19 06:35 AM don't you mean the one in the boat? 06-Jan-19 06:35 AM well just a bit NaOH to your oil sample and see if anything happens 06-Jan-19 06:36 AM in order to find out what exactly? 06-Jan-19 06:36 AM see if it turns into soap? 06-Jan-19 06:37 AM if its a natural oil 06-Jan-19 06:37 AM yes 06-Jan-19 06:38 AM the new pulsecap handwash (tm) 06-Jan-19 06:38 AM would buy & use 10/10 06-Jan-19 11:04 AM If your are worried about mixing then you can't avoid it by oil change because the oil is all permeated into the capacitor layers. Really I suggest just using it as-is, but I would not push the ratings. Unless you are cycling it all day long you will probably move on to another project before it blows. Lots of HV tanks are not carefully dried out, and like all insulation based devices, caps have a bunch of margin so that they will be reliable across manufacturing variation and over time. I have tried and failed to blow out 50V caps at 300V. If the oil level is way down so that it might uncover stuff, then you might consider topping off. But just a bubble at the top is not such a big deal. 06-Jan-19 11:04 AM thanks! 06-Jan-19 11:04 AM so I guess I'll just try to solder it shut and put a warning lable on it 06-Jan-19 11:04 AM "Might Explode, don't know, good luck!" 06-Jan-19 11:13 AM Yeah, or seal any way you can. It's painted and oily, right? If leak is not under fluid pressure when upright then your can just cover it with anything you can get to stick. something like putty or silicone. 06-Jan-19 11:15 AM not sure about long term stability of something like that 06-Jan-19 11:15 AM just reflowing the solder might be fine 06-Jan-19 11:20 AM Yeah, on thinking, this is going to get exposed to some pressure when it warms up. Utility transformers have a "breather" which is an air filled expansion tank on the top. But with sealed caps I guess the sides just flex in and out a bit. 06-Jan-19 11:21 AM yeah, they're really thin, even with my sealed ones it is quite easy to deform them 06-Jan-19 11:58 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/isolan_porzelator2-32B43.jpg 06-Jan-19 11:58 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/isolan_porzelator-FFBB0.jpg 06-Jan-19 11:58 AM whoops, wrong way round 06-Jan-19 11:58 AM but hey 06-Jan-19 06:02 PM did you weigh both caps to get a feeling how much oil has been lost? 06-Jan-19 09:10 PM Just got my Suction Control Valve to operate at varying percentages.. but with the solenoid driver evaluation board current sense resistor used, it only has a resolution of about 10 values.. and sure 10 steps is better than none, but looking to possibly increase that, initially by using a larger sense resistor 07-Jan-19 01:22 AM @Pan Da Nope, they're too heavy for our kitchen scale 07-Jan-19 01:22 AM They are around 3 kg, our scale does 2 kg max, 2.5 with tare 07-Jan-19 04:58 AM bathroom scales work well for that 07-Jan-19 04:58 AM they can even calculate the fat levels... [sorry for the bad pun] 07-Jan-19 05:03 AM they don't if they're cheap, digital and have a 100 g Resolution ;) 07-Jan-19 05:03 AM the oil has a low density and only a couple of ml could have escaped 07-Jan-19 05:03 AM I think the sound during shaking is mostly due to air tahat got in and not oil getting out, as in tue cap had a lower pressure intetnaly 07-Jan-19 05:10 AM yeah, you think and guess 07-Jan-19 05:10 AM but you don't measure 07-Jan-19 05:14 AM because right now I don't have the proper tools for that 07-Jan-19 05:17 AM ... 07-Jan-19 05:22 AM I'm just gonna wait until you're back and measure it with one of your scales 07-Jan-19 05:22 AM at least the leak seems to be fixed 07-Jan-19 06:21 AM @GigaSquirrel nice! Did you use a soldering iron? Or torch? I was worried it might be hard to get the solder to flow because of paint and oil. 07-Jan-19 06:22 AM I used my daily driver soldering iron, the TS100 07-Jan-19 06:22 AM at 450°C and with some additional solder it powered through the old joint like it was nothing 07-Jan-19 06:23 AM I cleaned the cap before with break cleaner, don't want to evaporate and breath the oil 07-Jan-19 06:23 AM @robamacl did you have any problems with you teflon hose and the water in it? I'm not sure if I asked you yesterfay 07-Jan-19 06:24 AM @Koelzer the Teflon is just for gas. The water is in continuous copper tube U. 07-Jan-19 06:25 AM oh ok... 07-Jan-19 06:25 AM I see some rubber hose too, is it really exposed to HV or what material is it? 07-Jan-19 06:26 AM The Teflon slip fits in the back of the ceramic tube (same nominal diameter) 07-Jan-19 07:10 AM The short bit of viton is a coupler to the copper feedthru tube for process gas. What's on the other side is what we are going to vent in the chamber anyway, so no concern with permeation. And I have lots of elastomer seals anyway, the buna bell jar gasket for one, as well as lots of KF flanges. The process gas also goes thru a viton segment out in the air. I use a pinch clamp on this to direct to one cathode or the other. My impression is that the elastomer seals and tube do not become a big issue until below 1e-6. 07-Jan-19 07:10 AM For my coating I have mostly been running only down to 1e-4 before adding gas and going up to 100-200 e-3. I can reach that level of vacuum pretty fast if they chamber was only open a minute or two. 07-Jan-19 03:27 PM ayy, you're alive, nixie! 07-Jan-19 03:28 PM Yeah, I slept all evening and now I cant, obviously, but still bedridden. 07-Jan-19 03:28 PM (tl:dr for the rest: I hurt my back and I almost can't walk, but nothing serious) 07-Jan-19 03:30 PM build a motorized wheelchair! 07-Jan-19 03:30 PM Rofl 07-Jan-19 03:30 PM Would be fun, but it is complicated from bed. 07-Jan-19 03:30 PM I managed to send the helmet extension cord to OSHpark to manufacture 07-Jan-19 03:32 PM yay 07-Jan-19 03:32 PM 19$ x 3 boards 07-Jan-19 03:32 PM Free shipping. 07-Jan-19 03:32 PM I can't complain actually. 07-Jan-19 03:32 PM that's quite cheap for flat flex iirc 07-Jan-19 03:32 PM Yeah! 07-Jan-19 03:32 PM Foto de Armilar Zifferblatt 07-Jan-19 03:32 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG-20190104-WA0003-AE8CB.jpg 07-Jan-19 03:32 PM It's a micro usb extension cord with 90° connectors. It will be used to make an external charging port (altough the cable is fully connected) for my internal bluetooth headset on my motorbike helmet. 07-Jan-19 03:32 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181226_190157-8F639.jpg 07-Jan-19 03:32 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_s0np14-28253.jpg 07-Jan-19 03:32 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_-55tmka-D3E2E.jpg 07-Jan-19 03:37 PM looks like a factory part ^^ 07-Jan-19 03:37 PM XD 07-Jan-19 03:37 PM Its my first time doing many things at once. Flexy pcb: only dreamed I would ever do it. Rubber 3D print: making a functional part. 07-Jan-19 03:54 PM I know this is just low tech for this chat, but I enjoy mundane hobbies too. 07-Jan-19 04:15 PM Yet to do flex, but 19usd is a very sane price. 07-Jan-19 04:38 PM Totally. A friend said to me: "make two hard boards and join them with cabling" And I said "f**k no, if I do it, I do it properly". As this goes inside a helmet, I want low profile, very pro-looking. 07-Jan-19 09:10 PM so tired from school.. basically filed aluminum all day, even stayed a bit later to catch up and use the bigger lathe 08-Jan-19 01:31 AM And what did you lathe? 08-Jan-19 02:45 AM @rfs the boards are 9*88mm, btw. 08-Jan-19 06:23 AM @Nixie just some support rods, we are making 'hand pusher press' spring loaded sliding shaft thing to push watch hands back onto a cleaned and asembled movement 08-Jan-19 06:23 AM making the bushings today 08-Jan-19 03:11 PM @Nixie Ok good to know. I'm still very delighted to hear how cheap flex fabrication has gotten at so small volumes. 08-Jan-19 03:13 PM @GigaSquirrel we should try and x-ray your ex-leaky pulse cap 08-Jan-19 03:13 PM just came to my mind 08-Jan-19 03:13 PM yep, thought about that, too 08-Jan-19 03:13 PM anyone got a mass attenuation coefficient for insulating oil? 08-Jan-19 10:33 PM Yeah. I got pricing from fpcway for 10, and it came up to 96$, but from those, 25 where shipping, they only offered DHL. True that the boards will take a lot less time to be made, but price for price including shipping, they are more expensive (6,5 vs 9,6$ per board, and a huge upfront investment) had they offered e-packet service of 1$ or something, it just might be about a multiple of the OSHparks, but since they didn't, I went with the cheapest option. 09-Jan-19 06:32 AM kinda ontopic, has someone some experience with puls x-ray tubes? 09-Jan-19 06:35 AM What type of pulsed x ray tubes? 09-Jan-19 06:35 AM hahaha, yeah, I think there stops my ""knowledge"" 09-Jan-19 06:35 AM coldcathode 09-Jan-19 06:35 AM with a penlike electrode afaik 09-Jan-19 06:35 AM when I'm hope I'll send some pictures 09-Jan-19 06:35 AM is a soviet one from former udsse 09-Jan-19 06:39 AM Now you are getting into my area of study lol 09-Jan-19 06:39 AM type was IMA-6D 09-Jan-19 06:40 AM What do you need to know 09-Jan-19 06:40 AM nice yeahhh!!! 09-Jan-19 06:40 AM xD 09-Jan-19 06:40 AM dont worry of me outperforming you, definitly not going to happen :-D 09-Jan-19 06:40 AM I'll ask later when my brain is actually functional 09-Jan-19 07:23 AM moin 09-Jan-19 07:24 AM moin! 09-Jan-19 07:31 AM moin 09-Jan-19 07:31 AM moin 09-Jan-19 09:17 AM Boing! 09-Jan-19 09:18 AM C-C-COMBOBREAKER 09-Jan-19 03:08 PM Groin 09-Jan-19 03:12 PM N-N-N-NUTBREAKER! 09-Jan-19 03:18 PM D-D-D-DIELECTRIC BREAKDOWN! 09-Jan-19 03:22 PM hahaha 09-Jan-19 03:22 PM CND? 09-Jan-19 03:26 PM no nuclear disarmament :< 09-Jan-19 11:22 PM Morning! \o/ 09-Jan-19 11:52 PM good morning :) 10-Jan-19 03:34 AM moin 10-Jan-19 03:36 AM moin 10-Jan-19 12:12 PM guten morgen 10-Jan-19 12:14 PM Tach auch! 10-Jan-19 01:32 PM Bit late to say that, methinks 10-Jan-19 01:32 PM XDDD 10-Jan-19 01:42 PM it's universal 10-Jan-19 02:22 PM Transformer question: 10-Jan-19 02:22 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-C50E9.png 10-Jan-19 02:22 PM On the bottom right, it says to connect in parallel the 5-6/7-8 coils 10-Jan-19 02:22 PM by the resistance, I understand those are the primary, and the secondary is 1-4 10-Jan-19 02:22 PM and the parallel is to handle more current. 10-Jan-19 02:22 PM Am I right? 10-Jan-19 04:36 PM sounds about right 10-Jan-19 04:36 PM probably to do with manufacure... thinner wire may be easier to handle 10-Jan-19 05:28 PM ^^ 11-Jan-19 12:54 AM btw pcbs for the gauge display are ordered 11-Jan-19 04:27 AM The separate windings also gives you more driving options, configure as center tapped and use a push pull driver, or drive from higher voltage with series connection. 11-Jan-19 06:20 AM Nice! 11-Jan-19 06:20 AM (about the pcbs) 11-Jan-19 06:20 AM Interesting. I have put them in parallel as per specs. I am working at the very lowest limits, I guess. 11-Jan-19 10:03 AM In case anyone wants to know, my mini crt from an old cameras viewfinder uses 1200V acceleration voltage 11-Jan-19 10:44 AM another unit has 1800V 11-Jan-19 11:14 AM hmmm are they cheap? 11-Jan-19 11:14 AM those tubes 11-Jan-19 11:20 AM yes 11-Jan-19 11:20 AM you can get the cameras for <5€ 11-Jan-19 11:35 AM oh nice 11-Jan-19 03:01 PM Anyone else around here familiar with DSP work? Have a TI C2000 launchpad: http://www.ti.com/tool/LAUNCHXL-F28379D Been getting CCS setup and getting prepared to work on using it to drive an XYZ gantry I have that has +10/-10V motor controllers with Encoders. So going to have fun learning how to write PID loops and such. 11-Jan-19 03:01 PM The CPU itself is quite interesting with its layout and how the two cores talk to one another. They are quite separate actually only connected by a few registers and share memory spaces. They have their own DMA units and CLAs (math coprocessor things) 11-Jan-19 03:01 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-5AA7B.png 11-Jan-19 03:01 PM Either way, I figured I'd share here since DSP work would seem at-least somewhat relevant :) 11-Jan-19 03:19 PM It'll be to replace the old ISA motor controller this thing has in it since I can't find drivers for anything and the system currently runs some antiquated OS that... Yea... Just not going to be easy to work with sadly. https://imgur.com/qqGmiaz 11-Jan-19 03:19 PM https://i.imgur.com/PrtIsHo.jpg 11-Jan-19 03:19 PM It was used for putting the DAM/Ecapsulation around dies on a cleanroom floor... it even has a feed through which I don't think the previous company ever used.... I wanted to turn it into a pick and place but it might be more fun to try and utilize it for some other things... 11-Jan-19 03:19 PM But having my own motor controller, and eventually I/O controller unless I can get enough I/O off the DSP somehow, will make it many times easier to work with. 11-Jan-19 03:26 PM not sure if it its worth rolling your own controller, there are plenty of options around that can drive such things 11-Jan-19 03:26 PM Niiiiiiice 11-Jan-19 03:26 PM That are really expensive and not really 100% compatible with most open source software for like say PnP and such. So you'll end up needing to write your own "Driver" for the thing anyway. 11-Jan-19 03:26 PM I was interested in learning how to work with a DSP anyway, and so part of this is a personal education more than anything. 11-Jan-19 03:27 PM huh, most everything will do +-10V 11-Jan-19 03:28 PM And eventually knowing how to work with a DSP will be quite handy for fab processes and controlling things, even if it may be overkill... 11-Jan-19 03:28 PM and openpnp just does step/dir from the grbl which most drives will also take 11-Jan-19 03:28 PM Eh most of the controllers I see expect you to be using steppers.... And if they have +10/-10V support they aren't used often so people don't really support them well. 11-Jan-19 03:29 PM or you just use linuxcnc with a mesa card 11-Jan-19 03:29 PM Also most of these controllers are like 500+ dollars which while maybe not overpriced, its a lot of money when I can probably throw something together for 100-200 and have the education afterwards. 11-Jan-19 03:29 PM Those MESA things... right... 11-Jan-19 03:29 PM Linux CNC... 11-Jan-19 03:29 PM would rather not use software to control something with the capacity to easily kill someone 11-Jan-19 03:29 PM I've seen opensource software crash way too much as it is... Would rather not trust my life on it. 11-Jan-19 03:31 PM huh? 11-Jan-19 03:31 PM or my expensive hardware. 11-Jan-19 03:31 PM you are basically doing the same 11-Jan-19 03:32 PM Not at all. 11-Jan-19 03:32 PM you are much more likely to crash your machine trying to tune your pid loop than just using a working solution 11-Jan-19 03:33 PM So your claiming LinuxCNC to be a perfectly working solution for my device? 11-Jan-19 03:34 PM yes 11-Jan-19 03:34 PM and your safety argument is bs 11-Jan-19 03:34 PM plus I've seen much more enterprise software crashing than os btw... 11-Jan-19 03:35 PM linuxcnc might not be a perfect solution for your application, but it is a very good one 11-Jan-19 03:35 PM You seem to be claiming that code on a DSP is more volatile than code running under an OS? 11-Jan-19 03:35 PM and it supports legacy analog drives out of the box 11-Jan-19 03:36 PM I'd rather have my endstop/speed/etc control done in hardware than in software... 11-Jan-19 03:36 PM Pretty sure that's the way most industry does it. Just hobbiests avoid it because of the time/complexity/cost involved. 11-Jan-19 03:36 PM LinuxCNC is realtime, which is just as good as your DSP... 11-Jan-19 03:37 PM I don't think I saw support for my motor controller. 11-Jan-19 03:37 PM What? 11-Jan-19 03:37 PM LinuxCNC runs on a realtime kernel. The possibilities for the software to crash are more or less the same as for you self-implemented PID 11-Jan-19 03:37 PM LinuxCNC isn't some random "hobbyists software", it's controlling mills 10 times the size of your pnp... 11-Jan-19 03:37 PM If you want to stick to your DSP, fine, not my problem. 11-Jan-19 03:37 PM However I highly suggest giving LinuxCNC another try as you obviously didn't understand how it works 11-Jan-19 03:40 PM software estop is extremely common in the industry 11-Jan-19 03:40 PM it doesn't need "support" for "your" controller, it is just analog and encoder feedback 11-Jan-19 03:40 PM it is a common control scheme from that timeframe 11-Jan-19 03:41 PM Look I said I was playing with the DSP to learn about it and eventually develop a motor controller with it, and I showed what for. Instead of making a suggestion on a better solution your telling me I'm stupid for doing something one way. I am pretty sure back when I got this thing I looked into LinuxCNC fairly extensively as an option but was not happy with it or decided it was going to be a lot more effort than it would probably end up being worth. 11-Jan-19 03:41 PM I'll look back into LinuxCNC but I don't need any more information and or tone from you thanks. 11-Jan-19 03:45 PM hm, but you're trusting your first dsp project more than linuxcnc and think it would be easier to completly do it by your own instead of working into a sophisticated software like linuxcnc? not sure about that, I think niklas points are valid and he probably didn't mean to be mean, sometimes online conversations are just missing the other components of interaction :) 11-Jan-19 03:45 PM but I dont know your background 11-Jan-19 03:54 PM Hey, hey, let's try to be calm. 11-Jan-19 03:54 PM @Conmega have you thought about MACH 3? 11-Jan-19 03:54 PM (not sure if it has the capabilities you require, though) 11-Jan-19 03:55 PM That's assuming the other software I planned to use supports LinuxCNC and this is treating LinuxCNC like a plug and play system... From my research awhile ago I recall people working on getting things setup for months and months. And quite honestly I've always found it way more of a pain to debug things when I don't understand how the underlying hardware/software/firmware works. Also I completely understand that my "first DSP project" is likely less refined than something that has the pedigree of LinuxCNC. But I also don't plan to make the thing overnight nor do I expect it to work first thing. What I do expect is to learn a lot and have fun with it. But I suppose that's a stupid goal nowadays. Seems a lot of people think that anyway... sigh 11-Jan-19 03:57 PM Nope, that's pretty much what everyone is doing here, so you are among equals. (don't look at me, though) 11-Jan-19 03:59 PM Right but my point is I'm a part of a lot of servers with similar goals and "equals" but me or someone else speaks about a project slightly off topic and some people seem to lose their morals on the topic and calls someone's idea or work stupid instead of being encouraging or if they are to suggest something else at-least make sure that they just want the easy solution first. 11-Jan-19 03:59 PM Instead of "you could use LinuxCNC" it feels a lot like "you'd be better off because your goals aren't ideal or feasible" 11-Jan-19 03:59 PM Sorry to hear that, I do want to see how you do, though. 11-Jan-19 03:59 PM Totally understand, I'm on the semiconductors thingy...prety much insane. 11-Jan-19 03:59 PM Well, @everyone we ALL have to learn the lesson, okay? let's try to be more encouraging (not to mean that you can have your preferences) But I would like this to continue being a place where everyone wants to hang. I like to hang here a lot, and from time to time we will have our differences, just remember to try to be diplomatic, so it settles quickly. Okay? 11-Jan-19 04:05 PM Also on the Mach3 suggestion I think its not as good as an option as LinuxCNC is unless your doing SPECIFICALLY CNC stuff... In which case I think it has the better user interface if that's of importance? But I could be wrong. 11-Jan-19 04:05 PM You realize the at-everyone popped a notification up on probably 100 people’s phones/desktops..... 11-Jan-19 04:06 PM I believe he knows what it does. 11-Jan-19 04:09 PM It does 11-Jan-19 04:09 PM good 2AM folks 11-Jan-19 04:10 PM @davidc__ yes, I realize. I think it was important to understand the situation and LEARN (just emphasizing, not showting) of it. This kind of situation can get out of hand quickly, and it is important to recognize it. 11-Jan-19 04:10 PM (recognize the runaway situation, I mean) 11-Jan-19 04:12 PM mach3 is pretty popular with hobby cnc guys but it has severe drawbacks like only working with buffered motion controllers if you want something else than your LPT 11-Jan-19 04:13 PM I use it with an LPT for my router. Sort of works fine, I guess. 11-Jan-19 04:13 PM I don't know much about linux CNC, got suggested to me by a friend, but I know bananas about linux, so I just politely declined any kind of relationship with it. 11-Jan-19 04:15 PM for most users it would be a dropin replacement 11-Jan-19 04:28 PM I think Linux being in the name of LinuxCNC has a lot less to do with Linux than you think lol 11-Jan-19 04:28 PM probably more of an excuse to put Tux in the logo XD 11-Jan-19 04:32 PM Might be! I am now set with MACH3 in the router, wich works fine, and some other crappy CNC software in the laser. 11-Jan-19 04:32 PM so it's not like I'm going to change that soon. 11-Jan-19 04:32 PM Do you have access to the products/chemicals it can use? 11-Jan-19 04:37 PM the original name was emc2 but there is a huge company that is called the same name and they tried to sue maintainers 11-Jan-19 04:40 PM uh yea EMC makes a LOT of enterprise stuff... Now know as Dell/EMC lol 11-Jan-19 05:41 PM I got asked to put the pannels on this scope and I'm failing to see how they ever fit in the first place 11-Jan-19 05:41 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190110_161613-88AB5.jpg 11-Jan-19 05:41 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190110_162307-976AD.jpg 11-Jan-19 08:25 PM lol 11-Jan-19 08:25 PM without hammering and cutting 11-Jan-19 08:25 PM or is that hole supposed to line up 11-Jan-19 08:25 PM I can see how it would go on, you'd stick the bottom down in first with it tilted out, once its down low enough you tilt it up towards with the half circle cut out towards that pipe I guess? 12-Jan-19 02:49 AM Morning! \o/ 12-Jan-19 04:07 AM moin 12-Jan-19 08:31 AM moin 12-Jan-19 09:49 PM hey, what did the ping a couple days back (yesterday??) go out for? 12-Jan-19 09:49 PM the @ everyone? 12-Jan-19 09:49 PM sounded like some nasty business happened 13-Jan-19 01:57 AM An argument/opinion started to snowball, and I tried to make everyone conscious that it requires effort to prevent those things when strong opinions are involved (aka, being diplomatic is hard, but makes for a good place to be) 13-Jan-19 11:01 AM what software can you recommend for (magnetic) electron optics simulation? 13-Jan-19 11:01 AM I've tried using https://electronoptics.com but the software is crap, it doesn't start because the evaluation phase expired 1970... 13-Jan-19 11:01 AM I do have matlab so a plugin for that would also be nice 13-Jan-19 11:37 AM Any experience with https://quickfield.com ? 13-Jan-19 12:14 PM Are you just looking to do field solving or full particle trajectories as well? 13-Jan-19 12:35 PM I haven't used either of those pieces of software. For field solving, I use Poisson Superfish. Doing actual particle trajectories often requires either much more complicated and expensive codes. EGUN, SIMION, possibly COMSOL. I think for ebeam trajectory stuff for free you can use PARMELA which can be downloaded from Los Alamos website, which can actually take field inputs generated from Poisson Superfish. It is a standard code in the accelerator world, but I've heard it is really complex and difficult to use, and the learning curve is really steep. 13-Jan-19 12:35 PM https://laacg.lanl.gov/laacg/services/serv_codes.phtml 14-Jan-19 03:02 AM Thanks! I've been using FEMM for magnetic field simulation. The reason why I'm looking for simultion software is because I'ld like to get a feeling for electron optics, because rn it seems counter-intuitive sometimes 14-Jan-19 03:02 AM It's not that I have this one problem that I would like to solve, its more than I'ld like to play around with different electron source and optics arrangements to get a feeling for what's going on. For this, I could live with a pure trajectories solver, feed by FEMM or Poisson Superfish, but I would highly prefer a all in one solution where I can modell complex optics and get plots for focus spot distribution, chromatic aberration for different energies etc. 14-Jan-19 08:44 AM Anyone here got experience with casting paraffin wax? 14-Jan-19 08:44 AM How do I minimize shrinking? 14-Jan-19 08:54 AM well, not shrinking as a whole, ofc that can't be stopped 14-Jan-19 08:54 AM but my casts sink in the middle, I'd rather have it shrink homogeneously 14-Jan-19 09:15 AM I'm at a surplus store near me that I had no idea existed and wow 14-Jan-19 09:22 AM i wish we had something like that... 14-Jan-19 09:31 AM Any good? 14-Jan-19 09:32 AM "Any good?" means...POST PHOTOS! Sneak them if you have to! 14-Jan-19 09:52 AM @Pan Da we should open one 14-Jan-19 09:54 AM Totally 14-Jan-19 09:54 AM You'd be the ruin of me, but totally. 14-Jan-19 09:55 AM in that case we'd be glad to ruin you 14-Jan-19 10:03 AM "you'll be so ruined when we're done with you..." 14-Jan-19 10:49 AM @GigaSquirrel no experience, but presume that's bc the inside takes longer to cool to a set state? 14-Jan-19 10:50 AM I think so, too 14-Jan-19 10:50 AM remelting the surface after everything has cooled down seems to help a bit 14-Jan-19 11:00 AM do it like they do in ice cube machines. dip a cooled finger in liquid medium and freeze the medium to said finger 14-Jan-19 11:05 AM that would give something that's pretty bad to stack 14-Jan-19 11:08 AM cylinders? 14-Jan-19 11:08 AM yes 14-Jan-19 11:08 AM I want bricks 14-Jan-19 11:13 AM bricks with no sag are hard to do 14-Jan-19 11:13 AM you can heat the mold walls to reduce the cooling there 14-Jan-19 11:15 AM hm, yes 14-Jan-19 11:15 AM or make a larger brick and trim off the top after it's cool enough to not sag anymore but not rock solid yet 14-Jan-19 11:16 AM I want to avoid "machining" the wax, that's what all the effort is for 14-Jan-19 11:16 AM "machining"... one cut with a knife... 14-Jan-19 11:17 AM if it was that easy 14-Jan-19 11:17 AM huh? 14-Jan-19 11:17 AM ok, cut with a hotknife 14-Jan-19 11:17 AM where's the problem? 14-Jan-19 11:18 AM the wax goes from soft dough to brittle mess with no inbetween 14-Jan-19 11:19 AM oh. ok 14-Jan-19 11:19 AM yep 14-Jan-19 11:19 AM really sucks to work with it 14-Jan-19 11:19 AM hmmm. 14-Jan-19 11:19 AM at what temperature does it solidify? 14-Jan-19 11:20 AM liquid to dough is ~50°C, dough to brittle is ~25°C 14-Jan-19 11:24 AM you can dissolve pe in your wax to make it harder 14-Jan-19 11:24 AM or generally use a different kind of wax that has less shrinkage 14-Jan-19 11:26 AM I already have that wax, as leftover from another project 14-Jan-19 11:27 AM you've got a 3D printer. why don't you just print a lid for the forms... or simply any custom mold for it! 14-Jan-19 11:27 AM make the top domed, so the shrinkage is compensated 14-Jan-19 11:28 AM yeah, let's waste tons of PLA! 14-Jan-19 11:28 AM or just cast the stuff in layers 14-Jan-19 11:28 AM like 5mm thick layers 14-Jan-19 11:28 AM they should cool quickly and evenly 14-Jan-19 11:28 AM especially when the mold is snowcooled 14-Jan-19 11:28 AM wait, better keep it at room temperature so the layers melt together 14-Jan-19 11:32 AM I think I'm gonna spare myself 95% of the time and effort and just remelt the sutface 14-Jan-19 11:32 AM and live with ~5mm sinkdown 14-Jan-19 11:33 AM that's not the "BECAUSE WE CAN"-mentality i want to see! 14-Jan-19 11:35 AM that would be casting a giant plate of wax, building a CNC hot wire cutter and make blocks that way 14-Jan-19 11:35 AM totally worth the effort 14-Jan-19 12:05 PM @GigaSquirrel From what I have read, with casting aluminium one intentionaly has sacrifacial structures that "supply" the material to the wanted part as it contracts. Youtube should have some videos and the "backyard metalcasting" folks should also. As aluminium shrinks when it cools. 14-Jan-19 12:05 PM But if it sucks to "machine" then that might not be an option 14-Jan-19 12:06 PM I'm casting into a muffin tray, no way to add a "fill tube" 14-Jan-19 12:06 PM I do recall reading on hackaday about some "diy machinable wax" style of things where some dude dissolved LDPE (aka plastic bags) in to hot wax to improve it's machinability. 14-Jan-19 12:06 PM ok 14-Jan-19 12:06 PM @GigaSquirrel yes, a lid. ut you don't want that, so... 14-Jan-19 12:06 PM I like the PE Idea of sync and you 14-Jan-19 12:07 PM https://hackaday.com/2016/06/11/new-cnc-machine-diy-machinable-wax/ 14-Jan-19 12:08 PM sounds like that combines the best properties of both, thanks! 14-Jan-19 12:09 PM @GigaSquirrel how much does the print head of your 3D printer weigh? 14-Jan-19 12:10 PM like just the extruder? 14-Jan-19 12:10 PM one stepper motor, a bit of metal, some cables.... 14-Jan-19 12:10 PM I'd guess 150-200g? 14-Jan-19 12:11 PM hmmm, that sounds pretty good tbh 14-Jan-19 12:11 PM have you got some pictures how it's attached to the next axis? 14-Jan-19 12:13 PM two screws 14-Jan-19 12:13 PM into the sled 14-Jan-19 12:13 PM why? 14-Jan-19 12:19 PM just had the idea to design a machining attachment. 200g should be enough for a small bldc spindle 14-Jan-19 12:19 PM just imagine the possibilities of combined printing and milling 14-Jan-19 12:21 PM it's way to floppy for that 14-Jan-19 12:21 PM oh and btw, the ldpe doesn't seem to reduce the shrinking, just improves the machinability 14-Jan-19 12:21 PM @GigaSquirrel floppy for what? at the moment i thought about machining wax blocks on it XD 14-Jan-19 12:22 PM you can easily push it ~5mm without any amount of force 14-Jan-19 12:22 PM yeah, but if I can't cast it without shrinking I can at least sand / cut it down with the ldpe in it 14-Jan-19 12:22 PM and it might leave less wax stains 14-Jan-19 12:24 PM sanding will cost you probably as much in sanding paper as buying new wax blocks :-P 14-Jan-19 12:30 PM a cheese grater or vegetable slicer might do the job 14-Jan-19 12:31 PM ...that might actually work 14-Jan-19 12:31 PM I know 14-Jan-19 12:34 PM yeah, and i am surprised. :-P 14-Jan-19 01:24 PM Oh the surplus place... Got photos. will put them on imgur later 14-Jan-19 01:24 PM Also they had a MASSIVE ion pump for like 50 bucks... 14-Jan-19 01:24 PM I may go back for it... 14-Jan-19 01:24 PM Awesome! 14-Jan-19 01:24 PM like massive as in 8 or 10 inch conflat connection big 14-Jan-19 01:24 PM like jesus 14-Jan-19 01:25 PM but aren't ion pumps dead after some time on air? 14-Jan-19 01:25 PM I thought they could be refurbed or something 14-Jan-19 01:25 PM guess cleaning the plates 14-Jan-19 01:25 PM don't know, there are other experts on that on this server ^^ 14-Jan-19 01:25 PM but they are getting a shipment in from one of IBM's old facilities Thursday 14-Jan-19 01:25 PM like as in probably more vacuum pumps 14-Jan-19 01:25 PM oh myy 14-Jan-19 01:26 PM yeaaa 14-Jan-19 01:26 PM totally going back then 14-Jan-19 01:26 PM but they had TONS of things 14-Jan-19 01:26 PM completely unrelated they had panels off OLD IBM 700/7000 series machines from the 50s? 14-Jan-19 01:26 PM totally got one 14-Jan-19 01:26 PM Also got a REALLLLLYYYYY fancy X/Y Rotation motor controlled table 14-Jan-19 01:26 PM with the rotation part having indents for wafers 14-Jan-19 01:26 PM of different standard sizes 14-Jan-19 01:26 PM I assume this thing came off an inspection table or something 14-Jan-19 01:26 PM but oh is it going to be fun to play with 14-Jan-19 01:27 PM argh why don't we have something like that in germany >.< 14-Jan-19 01:28 PM Thought you had a scrap place? 14-Jan-19 01:28 PM I mean its same difference basically, except this stuff is purchased from the place instead of picked up for free or payed to take away 14-Jan-19 01:28 PM yeah, but that's literally scrap. 14-Jan-19 01:28 PM yeah, but most equipment there is literally thrown away 14-Jan-19 01:28 PM aka it demands a higher price 14-Jan-19 01:28 PM yeaa 14-Jan-19 01:28 PM that can be a problem 14-Jan-19 01:28 PM like, usable for parts only in most cases 14-Jan-19 01:29 PM but this guy says he gets whole units and has to take things off 14-Jan-19 01:29 PM of there is any stuff in good condition it's a great deal, but that's like 3x a year max 14-Jan-19 01:29 PM like there were tons of weird high vacuum bits with no specific standardization laying around 14-Jan-19 01:29 PM yea I dunno how often this place has GOOD stuff 14-Jan-19 01:29 PM it may have just been because no-one as crazy as me has shown up 14-Jan-19 01:29 PM but he says he sells things on ePay from time to time 14-Jan-19 01:29 PM but he's reasonable about it, if it can get like 250 easy on ebay hes like, eh 100 bucks? 14-Jan-19 01:29 PM because he understands that its more hassle and cost to sell on ebay... 14-Jan-19 01:29 PM so the guy is nice at-least 14-Jan-19 01:31 PM wanna swap? 14-Jan-19 01:31 PM lol your always welcome to visit :P 14-Jan-19 01:31 PM good luck getting some of this stuff through the airport though 14-Jan-19 01:32 PM good luck with getting me through an airport, with my google & ebay search history 14-Jan-19 01:34 PM and your irradiation. the detectors would probably just self-destruct... 14-Jan-19 01:34 PM ^^ 14-Jan-19 01:34 PM I'd gladly get rid of the scrap yard if something like the los alamos black hole moved here 14-Jan-19 01:35 PM depends on the prices 14-Jan-19 01:35 PM and i want both. 14-Jan-19 01:36 PM doesn't matter 14-Jan-19 01:36 PM I would like at least the possibility to buy stuff like that 14-Jan-19 01:37 PM balzer lager :-P 14-Jan-19 01:39 PM as if 14-Jan-19 01:39 PM most of the sh...tuff there is rotten like hell 14-Jan-19 01:39 PM almost everything is broken because it was "stored" at least a year outside 14-Jan-19 01:42 PM I wish we had good surplus in Washington 14-Jan-19 01:44 PM yeah it really depends on where you are located and what the local industries are 14-Jan-19 01:45 PM We have lots and lots and lots of servers 14-Jan-19 01:48 PM I heard Boeing used to have a good surplus store. 14-Jan-19 01:48 PM That's long gone... 14-Jan-19 01:49 PM UW Surplus is teeming with old retired guys 14-Jan-19 01:49 PM I think the best way to get deals is asset liquidation auctions 14-Jan-19 01:55 PM I was only at one liquidation so far, and a bit too late to get the best stuff 14-Jan-19 01:55 PM but still great 14-Jan-19 01:56 PM Uw stuff seems to always go for way to much money 14-Jan-19 01:57 PM @GigaSquirrel Dillitzer? 14-Jan-19 01:57 PM don't remember the name, but I'm talking about the gas station display guy 14-Jan-19 01:58 PM yup, dillitzer. we were too late for the good stuff, but just in time for the free stuff, so... not a bad deal, i think 14-Jan-19 01:58 PM as I said, still great 14-Jan-19 01:58 PM oh, and some widows sold their husbands stuff 14-Jan-19 07:04 PM One day I am going to sign off this group... XDDDDD 14-Jan-19 07:04 PM All the fancy things you find... 15-Jan-19 01:28 AM you just need to move to a more hacker-friendly area 15-Jan-19 01:28 AM maybe your new job will have an awesome electronics container 15-Jan-19 04:11 AM hmmmm 15-Jan-19 04:11 AM let's send nixie a care package? next few trips to the scrapyard put something usable aside for him 15-Jan-19 04:14 AM good Idea 15-Jan-19 04:17 AM DHL wants 20 Euros for 10 kg 15-Jan-19 04:17 AM not a bad deal 15-Jan-19 04:17 AM I bet they'll manage to trash even the stuff from the scrapyard 15-Jan-19 04:18 AM sends a massive lead brick - arrives in 15 pieces 15-Jan-19 04:18 AM yep 15-Jan-19 04:40 AM https://imgur.com/a/KuzxraL 15-Jan-19 04:40 AM the album 15-Jan-19 04:40 AM want 15-Jan-19 04:40 AM Heres that ion pump 15-Jan-19 04:40 AM https://i.imgur.com/M4lg5GZ.jpg 15-Jan-19 04:40 AM https://i.imgur.com/08dr9P9.jpg 15-Jan-19 04:40 AM https://i.imgur.com/GdBbJWL.jpg 15-Jan-19 04:40 AM OH and if anyone needs diamond cutting blades... 15-Jan-19 04:40 AM and like 15-Jan-19 04:40 AM a LOT OF THEM 15-Jan-19 04:40 AM https://i.imgur.com/Ye6tOBC.jpg 15-Jan-19 04:40 AM They have god 15-Jan-19 04:40 AM I dunno 15-Jan-19 04:40 AM thousands 15-Jan-19 04:43 AM oh myyy 15-Jan-19 04:44 AM now I am wet. 15-Jan-19 04:44 AM lewd! 15-Jan-19 04:44 AM this is what hartnagel and RIM might have been back in the days... and balzer could have been if it wasn't for Mr balzer... 15-Jan-19 04:44 AM Yea those blades are from this company 15-Jan-19 04:44 AM http://www.dynatex.com/ 15-Jan-19 04:44 AM SEMICONDUCTOR WAFER DICING SOLUTIONS 15-Jan-19 04:44 AM I kinda figured owo 15-Jan-19 04:45 AM there's so much sexy stuff in those pictures... gnaaaaaahhhhh i want to go there 15-Jan-19 04:46 AM let's go there together 15-Jan-19 04:46 AM "occupation?" - "no, just visiting this time" 15-Jan-19 04:47 AM Get a plane here and I'll drive you from the airport :P 15-Jan-19 04:47 AM where is "here"? 15-Jan-19 04:48 AM Right so the place is called P&T surplus: 198 Abeel St, Kingston, NY 12401 Its in NY state, but its not far from the major airports in NYC/NJ area 15-Jan-19 04:49 AM cool, I've wanted to go to NYC for some time 15-Jan-19 04:50 AM why? 15-Jan-19 04:50 AM to buy good flux from rossman 15-Jan-19 04:50 AM lol, I'm personally not crazy about the city 15-Jan-19 04:50 AM It could become its own state :P 15-Jan-19 04:51 AM I've been there once at the age of ~12 and I want to see how close to reality my "childish" memories are 15-Jan-19 04:51 AM oh nice, only ~400euros per person 15-Jan-19 04:51 AM x.x 15-Jan-19 04:51 AM oh also: https://i.imgur.com/BHiyTSI.jpg 15-Jan-19 04:51 AM Is this a good N2 flow sensor? I may pick it up next time I'm up there if more interesting stuff doesn't appear lol 15-Jan-19 04:52 AM it'S a mass flow controller, not a meter 15-Jan-19 04:53 AM Right, sorry I just woke up 15-Jan-19 04:53 AM the brain is still coming online :) 15-Jan-19 04:53 AM That's what I meant though. 15-Jan-19 04:53 AM also... 15-Jan-19 04:53 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-5CB0F.png 15-Jan-19 04:53 AM good morning 15-Jan-19 04:53 AM I just made some coffee, want some`? 15-Jan-19 04:53 AM I saw a TONNN of regulators? like that? 15-Jan-19 04:53 AM where they bolt down with 4 screws and have two weird holes on the bottom surface? 15-Jan-19 04:54 AM coffeeeeeee! 15-Jan-19 04:54 AM I didn't realize it was a standard I suppose 15-Jan-19 04:54 AM and no ew, no coffee for me, tea please :P 15-Jan-19 04:55 AM well, you gotta make one your own 15-Jan-19 04:55 AM the MFC looks fine 15-Jan-19 04:55 AM tea is a great idea, too - let me see distant noises of someone digging through layers of stuff 15-Jan-19 04:56 AM Cool alright, I just didn't know if it was an easy to communicate unit or was unknown 15-Jan-19 04:56 AM that's generally my deciding point for thinks like that 15-Jan-19 04:56 AM is it serial with a well documented interface? or something... custom with no real documentation... 15-Jan-19 04:56 AM just takes +/- 15V for power and 0-5 V for setting 15-Jan-19 04:56 AM http://www.technofittings.com/pdf/SEC-4400.pdf 15-Jan-19 04:57 AM oh nice, I didn't find that doc in my quick search, thanks 15-Jan-19 04:57 AM But yea, I mean this place is getting a shipment from the old IBM silicon plant near me in East Fishkill soon... 15-Jan-19 04:57 AM They may get a fresh batch of HV stuff 15-Jan-19 04:57 AM If there is good stuff I'll try to get photos here 15-Jan-19 04:57 AM and I'm not against shipping things out, especially if they are of reasonable size 15-Jan-19 04:57 AM shipping things like turbo pumps may be a bad idea... 15-Jan-19 04:57 AM but flanges and valves and MFCs and stuff is reasonable 15-Jan-19 05:00 AM we need a livestream from this shop when you're there 15-Jan-19 05:01 AM Thanks for the offer @Pan Da but I could not ever repay that. 15-Jan-19 05:02 AM @Nixie no need to repay. i have too much stuff, and leaving nice things at the scrapyard just because my storage capacities are full is always a shame - so i'd rather send it out to someone who can use it than leave it and know it's gonna be destroyed 15-Jan-19 05:03 AM @Nixie actually we still owe you one 15-Jan-19 05:05 AM ? 15-Jan-19 05:05 AM I have done nothing 15-Jan-19 05:05 AM hah I may beable to make something live happen 15-Jan-19 05:05 AM looks over to nixie You know what you have done. 15-Jan-19 05:07 AM @GigaSquirrel and he won't pay for it! giggles 15-Jan-19 05:17 AM Huh....the inserts never arrived, that doesnt count. 15-Jan-19 05:20 AM der Wille zählt! 15-Jan-19 05:22 AM Hah, no, it doesn't. 15-Jan-19 05:22 AM yes it does! 15-Jan-19 05:25 AM Wishes don't cut metal! 15-Jan-19 05:25 AM XD 15-Jan-19 05:25 AM Whatever. 15-Jan-19 05:25 AM shh, don't fight it 15-Jan-19 05:37 AM Can't, back pain. 15-Jan-19 05:37 AM 15-Jan-19 05:39 AM a real pain in the... back 15-Jan-19 05:39 AM please, take the back jokes back a notch 15-Jan-19 05:40 AM you can't quiet us! you may mute us but we will be back 15-Jan-19 05:41 AM @Nixie get well soon, and I hope the pain won't be back after that 15-Jan-19 05:49 AM Back to the future, you people. 15-Jan-19 06:03 AM aye you saying we should get back on topic? 15-Jan-19 07:14 AM Oh yea, I totally got this btw 15-Jan-19 07:14 AM https://i.imgur.com/Ivz402R.jpg 15-Jan-19 07:14 AM Didn't pay that much... But man is it beautiful. 15-Jan-19 07:14 AM Need to figure out who made it, but those rings on the top are standard wafer sizes... I believe it probably came off an inspect table or something. 15-Jan-19 07:14 AM But its a heck of a solid xy rotary table 15-Jan-19 07:14 AM has to weigh about 100lbs 15-Jan-19 07:20 AM @Conmega this place is only an hour away from where I live. I'm gonna definitely want to check it out! 15-Jan-19 07:20 AM Do they also buy surplus items as well? 15-Jan-19 07:23 AM They buy and sell as far as I know. 15-Jan-19 07:23 AM @Applied_Ion let me know when your going to be there, we should meet up :P 15-Jan-19 07:23 AM Are you located in NY? 15-Jan-19 07:23 AM I'm in Poughkeepsie so I'm about 30 mins out 15-Jan-19 07:23 AM So, yes I'm in NY :P 15-Jan-19 07:24 AM Oh nice, I'm north of that in Upstate NY near albany 15-Jan-19 07:24 AM Oh I have a friend up in Albany, he was just here actually lol 15-Jan-19 07:24 AM Also apparently that XY table is made by a company called new england affiliated technologies or NEAT 15-Jan-19 07:24 AM They are now known as dover motion 15-Jan-19 07:24 AM https://dovermotion.com/products/linear-stages/xy-stages/ 15-Jan-19 07:24 AM on their newer products... Travel 50 - 300 mm Accuracy 8 μm TIR Repeatability < ± 1 μm Payload 175 kg 15-Jan-19 07:24 AM Like... Jeez... 15-Jan-19 07:24 AM It's alright though. I'll ruin the specs of mine by driving it by a cheap arduino with stepper drivers :P 15-Jan-19 07:24 AM But even with that it'll probably be the most accurate XY table in the house lol 15-Jan-19 07:32 AM What are you planning on using it for? 15-Jan-19 07:33 AM Was thinking at-least to start using it for the stepping of photolitho patterns using a DLP projector over it. 15-Jan-19 07:33 AM Its already setup to hold wafers so why not 15-Jan-19 07:33 AM I dunno there are tons of uses for an XY table like this... its just wonderful 15-Jan-19 07:33 AM I mean I could even remove the rotary part and just used the XY part for something as silly as a really precise 3D printer haha 15-Jan-19 08:14 AM Omg 15-Jan-19 08:14 AM You have all my envy. 15-Jan-19 08:14 AM stages like that are really neat and often cheap in the aftermarket 15-Jan-19 08:14 AM I have a few steinmeyer ones 15-Jan-19 08:21 AM sweet stages 15-Jan-19 08:48 AM I have a soft spot for linear motors. I have some high speed single axis stages and a big heavy 2-axis linear motor stage. 15-Jan-19 10:46 AM @N00N what @Pan Da says... 15-Jan-19 10:46 AM for an heated filament you need a power supply 15-Jan-19 10:46 AM something like 6.3V 1A to get the tungsten glowing hot 15-Jan-19 10:46 AM however, as this is the reference for the acceleration voltage, this needs to be isolated if you want to have the anode at ground potential which is often required 15-Jan-19 10:48 AM acceleration voltage was the word i was missing. thanks! 15-Jan-19 10:53 AM yeah ok, and you want it simplier? 15-Jan-19 11:33 AM ping @Applied_Ion 15-Jan-19 11:33 AM I found papers using anything from a single 1.5nm thick carbon tube up to a cathode area of 0.2cm² all covered with CNTs 15-Jan-19 11:33 AM in general it probably depends on the emission current I want to achive 15-Jan-19 11:33 AM for the single tube it is 100nA max, and 28mA for the 0.2cm² cathode 15-Jan-19 11:33 AM I guess I would try multiple CNTs on a tungsten wire tip 15-Jan-19 11:33 AM this should give ~100µA, depending on the quality of the CNTs 15-Jan-19 11:50 AM So CNT is not a necessary requirement 15-Jan-19 11:50 AM I thought you needed it for just achieving super small spot size from a single emitter, but sounds like it is just used for field emission, since .2cm^2 is substantially larger than a single fiber itself 15-Jan-19 11:56 AM I find CNT interesting becausen it makes a potential selfbuilt x-ray tube substentially easier 15-Jan-19 11:56 AM First, you don't need a isolated power supply for the filament. Also the coated tungsten tip is smaller than a heated filament, making the optics easier for the same focal spotsize 15-Jan-19 11:58 AM Assuming you have CNTs to use. However, there are other methods quite easier than this in regards to the physical tube, but the driver becomes more work. 15-Jan-19 11:58 AM okay? 15-Jan-19 11:58 AM I only know field and thermionic emission 15-Jan-19 12:06 PM Those are by far the most common and widely implemented for sure, but there are a few others less well known. A downside to field emission is that it usually requires much more strict vacuum than thermionic, getting into some real serious vacuum levels where ion pumping would dominate more 15-Jan-19 12:06 PM At least cold field emission like you are looking at requires much higher vacuum. Allows you to operate at lower voltages though, but at the price of vacuum. Thermionic field emission can run higher vacuum, but requires higher voltage 15-Jan-19 12:06 PM Always a tradeoff somewhere 15-Jan-19 12:12 PM hmmk I've read that CNTs are pretty forgiving when it comes to high vacuum 15-Jan-19 12:12 PM One paper states >1000h operation at only 10^-7mbar 15-Jan-19 12:12 PM Btw why is beryllium so much prefered as a x-ray windows over standard glass? I would expect SiO2 to absorp not much more x-rays than beryllium 15-Jan-19 12:17 PM Yes, CNTS allow for much easier field emission than conventional pure tungsten tips. Cost to it though is actually getting CNTs 15-Jan-19 12:18 PM okay sure 15-Jan-19 12:20 PM Beryllium has low density and has low absorbtion. This can be useful especially at the lower range where xrays may not penetrate glass. The thin material also needs to be strong enough for the atmosphere - vacuum interface while being thin enough for relatively lossless transmission 15-Jan-19 12:20 PM A beryllium window can be made substantially thinner than glass 15-Jan-19 12:32 PM okay 15-Jan-19 12:32 PM thanks :3 15-Jan-19 12:32 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Sun_2017_Nanotechnology_28_065201-A7193.pdf 15-Jan-19 12:32 PM all of these components can be bought online for <$100 16-Jan-19 05:49 AM Joined the server. 16-Jan-19 05:50 AM Welcome! 16-Jan-19 05:52 AM Joined the server. 16-Jan-19 06:10 AM Hey! XDDDDDDDDDDDDDDDD 16-Jan-19 06:10 AM Hi 16-Jan-19 06:15 AM @Conmega , @heye is on the same boat as you and me. requires counsel, especially about the sputtering chamber. He is more on your side of go big than my side of teeny tiny. 16-Jan-19 06:18 AM Hi @Conmega - well 'go big' really not yet. Just starting here and trying to make some step by step progress 16-Jan-19 06:19 AM "I want to sputter full wafers" counts as go big. XDDD, absolutely nothing wrong with that, don't worry, noone is going to judge you or think you are insane. (not insaner than everyone else in here) so don't be afraid of where you truly want to go. ^^ 16-Jan-19 06:20 AM Hm yeah, that's right. It's nice to have found some other insane people! 16-Jan-19 06:21 AM Btw, there are people from all around the globe, so, if you see that your comment/mention doesn't get answered/notticed, and then a flood of something else buries it, just try to reach again. 16-Jan-19 06:22 AM Ok, thanks for the tip ^^ 16-Jan-19 06:22 AM My pleasure. 16-Jan-19 06:22 AM So conmega also want's to make semiconductors? 16-Jan-19 06:23 AM Yup! He wants to do full wafers too, still in researching/getting components. 16-Jan-19 06:23 AM I just want to do single chips, so some of the troubles you both are going to encounter, are above me. (I don't need repetition stages, for example) 16-Jan-19 06:24 AM Sounds exciting, also europe or somewhere else in the world? 16-Jan-19 06:25 AM Southern spain. 16-Jan-19 06:25 AM We have like 2 spaniards, a bunch of germans...and other people. 16-Jan-19 06:25 AM (in EU) 16-Jan-19 06:25 AM we need more germans here 16-Jan-19 06:26 AM and a world war too. 16-Jan-19 06:26 AM since we're at it. 16-Jan-19 06:26 AM XDDDDD 16-Jan-19 06:26 AM Oh I'm from Germany btw. You mentioned there were lots of cheap supply shops here? You don't have any links for that, do you? 16-Jan-19 06:26 AM +1 16-Jan-19 06:26 AM OHDAMMIT! 16-Jan-19 06:26 AM Gigabequerel does 16-Jan-19 06:26 AM haHA! Another victory for the reich! 16-Jan-19 06:26 AM Moin! 16-Jan-19 06:26 AM Moin my back! 16-Jan-19 06:26 AM Moin ^^ 16-Jan-19 06:27 AM @heye anywhere close to munich? 16-Jan-19 06:27 AM @Nixie rather moan, in that case 16-Jan-19 06:27 AM (lots of inside jokes, you'll get into them eventually, this group is addictive) 16-Jan-19 06:27 AM Nah, Hamburg @GigaSquirrel 16-Jan-19 06:27 AM @Pan Da talk to my hand. 16-Jan-19 06:27 AM XDDDDDDD 16-Jan-19 06:27 AM Moin 16-Jan-19 06:27 AM ah, cool, we've got another user from HH here 16-Jan-19 06:29 AM @Nixie hello, hand. 16-Jan-19 06:31 AM Hellp @Pan Da I'm dad. 16-Jan-19 06:31 AM 16-Jan-19 06:31 AM Btw, slightly hijack, anyone with motorbiker friends here? 16-Jan-19 06:32 AM that might be a topic for @Pan Da 16-Jan-19 06:32 AM (moved to off-topic) 16-Jan-19 06:42 AM @heye interesting, what are you doing? 16-Jan-19 06:42 AM bc le me from hamburg too 16-Jan-19 06:47 AM I want to experiment with making semiconductors, but I'm just starting to build some equipment 16-Jan-19 06:49 AM student somewhere? 16-Jan-19 06:50 AM was student at TUHH 16-Jan-19 06:50 AM ok, then I probably don't know you 16-Jan-19 06:51 AM How about you? Are you a student somewhere? 16-Jan-19 06:51 AM yepp, HAW 16-Jan-19 06:52 AM Ah, yeah probably not ^^ I know very few people there as well, but not much. What are you studying? 16-Jan-19 06:52 AM EE 16-Jan-19 06:52 AM or better the IT/EE mix, whatever you wanna call it 16-Jan-19 06:52 AM NIce, I was doing computer science and engineering, so a bit similar. 16-Jan-19 06:53 AM oh yeah 16-Jan-19 06:53 AM very interesting, any connection to CCCHH/attraktor? 16-Jan-19 06:59 AM No, not really ^^ I went to CCC a few times, but not more than that 16-Jan-19 08:43 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190116_174257-D3CCD.jpg 16-Jan-19 08:43 AM looks nice 16-Jan-19 08:43 AM what's the estimated cost so far? 16-Jan-19 08:46 AM 10-15€ for a full kit 16-Jan-19 08:46 AM Just joined, what is that? 16-Jan-19 08:46 AM ohai 16-Jan-19 08:46 AM it's hardware to interface those dirt-cheap IGM-400 Vacuum gauges 16-Jan-19 08:47 AM the broken ones. :-D 16-Jan-19 08:47 AM Oh I have seen those on ebay 16-Jan-19 08:47 AM 10-15 Euros... i'd take one. 16-Jan-19 08:47 AM @Pan Da 3/4 of mine are virtually new, the 4th looks used but is working as well... 16-Jan-19 08:48 AM there was a load of them with toasty capacitors, that's where this joke came from 16-Jan-19 08:48 AM ah I see 16-Jan-19 08:49 AM Ah ok 16-Jan-19 08:49 AM and @Koelzer completely broke one, but that's another story 16-Jan-19 08:49 AM yeah the 4th has a crusty cap but still works 16-Jan-19 08:49 AM there's a text in #resources on where the name came from 16-Jan-19 08:50 AM what did happen to Diracs unit? 16-Jan-19 08:50 AM messed it up 16-Jan-19 08:51 AM haha, I misswired it somehow and it seemed to toast it right to the point of outputting >1kV ? 16-Jan-19 08:52 AM oh @niklas when replacing the cap, sometimes the solder pads fall off... that's no problem, there are test points and other components' solder pads in the vicinity. :-D 16-Jan-19 08:52 AM btw the 15€ are because I bought high quality connectors and made the pcbs yellow, if you can live with chinese connectors and green pcbs you can probably built this fpr <5€ 16-Jan-19 08:52 AM That sounds amazing, what's the range those can measure? 16-Jan-19 08:52 AM 10^-2 to 10^-9 ? 16-Jan-19 08:52 AM e-3 to e-9 16-Jan-19 08:53 AM DC to daylight! 16-Jan-19 08:53 AM http://www.fusor.net/board/viewtopic.php?f=10&t=12165&sid=8405aab05136e913a047e38948d61f75 that's my writeup 16-Jan-19 08:53 AM We're all proud about @GigaSquirrel for that one! 16-Jan-19 08:53 AM ❤ 16-Jan-19 08:55 AM and i hate him. he started it... 16-Jan-19 08:55 AM :-P 16-Jan-19 08:55 AM you're welcome, panda 16-Jan-19 08:56 AM so these output either 10V in idle or 7V when reaching 10^-3mbar? 16-Jan-19 08:56 AM in idle there is no output at all iirc 16-Jan-19 08:56 AM 10V means not activated or fault, in normal measurement condition 7V is the highest possible 16-Jan-19 08:57 AM oh sorry, what do you mean by idle? 16-Jan-19 08:57 AM 7 or 8 iirc 16-Jan-19 08:57 AM I guess idle would be the enable pin floating 16-Jan-19 09:05 AM I'm think I'm gonna order some more, anyone from germany / eu want some hornets? 16-Jan-19 09:05 AM @Nixie maybe? 16-Jan-19 09:05 AM looks like it's gonna be 15-20€ per piece 16-Jan-19 09:06 AM Where do you get them from? I may also have use for one (or two, it seems they like to be destroyed by their operators ^^) 16-Jan-19 09:07 AM I get them from an ebay seller, got some connections there and might get some discount 16-Jan-19 09:08 AM That's nice, where are you from? US? 16-Jan-19 09:08 AM munich 16-Jan-19 09:08 AM Ah ok, I saw some of those from US sellers, but with high shipping costs... 16-Jan-19 09:09 AM that's where the connections come in handy 16-Jan-19 09:09 AM Ahh ok 16-Jan-19 09:11 AM guess I'll order like 10 and "resell" them here to those interested 16-Jan-19 09:57 AM 16-Jan-19 10:32 AM @AdamMcCombs @Applied_Ion is there anything special when it comes to SEM filaments? Or can I just buy tungsten wire on ebay and bend it in shape as a replacement? 16-Jan-19 10:33 AM bending tungsten wire is... not the easiest thing 16-Jan-19 10:34 AM Even when it's 600-800°C 16-Jan-19 10:34 AM I thought at the crystal order at this temperature it is soft as butter 16-Jan-19 10:38 AM I've heated my .5mm W wire until white hot, didn't really make a change, still behaved like spring steel 16-Jan-19 10:38 AM the elastic range of spring steel, not the plastic one 16-Jan-19 10:40 AM at high temperature, tungsten gets pretty hard again 16-Jan-19 10:40 AM there's a windows where it is soft 16-Jan-19 10:40 AM oh, ok 16-Jan-19 10:40 AM https://giphy.com/gifs/psa-the-more-you-know-public-service-announcement-d2YVk2ZRuQuqvVlu 16-Jan-19 10:41 AM In fact, this is a well known failure mode in electron tubes 16-Jan-19 10:41 AM If the heater voltage is too low, the tungsten is very soft and can short windings of the filament because the gravity pulls it out of shape 16-Jan-19 10:46 AM huh, I always thought the issue with low heating voltage is cathode poisoning 16-Jan-19 10:46 AM >>If the tube filament is really much too cold, it may begin to suffer from cathode poisoning, as some specific unwanted chemical traces do not evaporate also, and this can develop into an emission killing surface. Such a tube may be recovered by the classical process, of over heating the filament, but with EML tubes we found this not needed. Besides a tube that was first under heated, and then over heated to "repair", it is easy to understand it will not be like a new one any more. 16-Jan-19 10:49 AM @niklas not so much special, just different specs. Tungsten bent in a hairpin is perfectly fine and common. Downside is lower current density, beam brightness, and lifetime. The standard filament is LaB6, which has lower work function, higher currents, better beam quality, longer lifetime. They can be poisoned faster by air though and are more costly. Tungsten can operate at worse vacuum levels, but lifetime is still limited. However for cost and ease, and if you don't mind changing out the filament more often, it will work fine 16-Jan-19 10:49 AM I can't imagine bending such thin wire would be much issue either. Now, if you are replacing a filament in a head yourself, if you want similar specs to how it was operating before it would be best to try to match the filament gauge and profile. But if you are planning on experimenting and optimizing output it's probably not that critical since you will be adjusting everything again anyway 16-Jan-19 10:49 AM However I'm not an expert in SEM at all, so it would be good to get the opinion of someone who has directly worked with them 16-Jan-19 10:53 AM cough adam cough 16-Jan-19 10:54 AM here is a good simple pdf overview looking at the general types: 16-Jan-19 10:54 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Electron_Sources-82E6B.pdf 16-Jan-19 10:56 AM could you please repost that in #resources ? I'd hate or this to get lost in the chat 16-Jan-19 10:56 AM sure lol np 16-Jan-19 10:57 AM thanks 16-Jan-19 10:58 AM Thanks :3 16-Jan-19 10:58 AM I might indeed need to replace a commercial SEM filament but for now it is just experimenting around a bit 16-Jan-19 10:58 AM And I have the choice of either buying 10pcs of for 70€ or 5m of tungsten wire for 5€... 16-Jan-19 11:01 AM 10 pieces of pre-made filament? 16-Jan-19 11:01 AM Does the commercial sem use tungsten? Or a LaB6 crystal emitter? 16-Jan-19 11:01 AM If it's the latter, you may have to get creative with the holding the tungsten wire filament in place 16-Jan-19 11:18 AM Yes 16-Jan-19 11:18 AM https://www.ebay.de/itm/AGAR-A054-Filamente-Wolfram-Kathode-fur-Cambridge-LEO-REM-10-Stck/263743695804 16-Jan-19 12:20 PM @niklas @GigaSquirrel It's totally possible to make your own filament. The hard part is spot welding 16-Jan-19 12:20 PM You need capacitive discharge to have any hope of getting the rise time. 16-Jan-19 12:24 PM Cant I use mechanical clamping, like a screw terminal? 16-Jan-19 12:28 PM Hang on I'm finding some recorces 16-Jan-19 12:28 PM https://hackaday.io/project/3281/logs 16-Jan-19 12:28 PM One of the project logs here describes the process. Its not that hard. 16-Jan-19 12:28 PM Also Rob has some posts on spot welding he wire at http://hackerfriendly.com/new-year-new-emitter/ 16-Jan-19 12:28 PM and http://hackerfriendly.com/experiments-in-nano-manufacturing/ 16-Jan-19 02:07 PM oohhh 16-Jan-19 08:43 PM https://en.wikipedia.org/wiki/Plasma_ashing 16-Jan-19 08:43 PM So I suppose since photoresist is more of an organic compound they use ashing, then for etching silicon they use reactive ion etching... 16-Jan-19 08:50 PM Looks like that. My understanding was that if you didnt care about aspect ratio as much you could just use a asher with a different gas 16-Jan-19 09:31 PM Hmm, maybe? Will have to look into it. 16-Jan-19 09:31 PM Oh, also, if I buy that ion pump at that surplus place for fun... What's the best way to hack up a power supply? Old Neon sign transformer? :P 16-Jan-19 09:34 PM Rectified possibly 16-Jan-19 09:34 PM need to figure out what kv it needs 16-Jan-19 09:34 PM nsts are used to hi pot a igp if it develops a wisker and starts field emitting 17-Jan-19 10:50 AM what is the typical wire thickness of tungsten wire in hairpin filaments? 17-Jan-19 10:50 AM the guy from @AdamMcCombs used .2mm wire, but that was for a FEM source 17-Jan-19 10:51 AM Depends on the power supply 17-Jan-19 10:52 AM I guess thinner = better? 17-Jan-19 10:52 AM because smaller crossover diameter and less current to heat 17-Jan-19 10:52 AM Not necessarily. You don't want it burning out every 10 hours 17-Jan-19 10:52 AM The other thing is to remember to annele it before alignment 17-Jan-19 10:53 AM what are typical values? 17-Jan-19 10:53 AM eg. for the AGAR A054 filament 17-Jan-19 10:53 AM I don't know off the top of my head. I spoke to someone who used to design fillaments but I don't remember numbers. 17-Jan-19 01:04 PM A054 is 0.125 mm 17-Jan-19 01:12 PM haha, I'm just pumping down my leak detector and you can hear the turbo fighting against some crap that must have accumulated in the system 17-Jan-19 01:12 PM you can periodically hear it spin down due to high load and then come up again slowly 17-Jan-19 01:13 PM the poor little thing 17-Jan-19 01:13 PM Sneaky 17-Jan-19 01:17 PM pfft, it better pump that stuff out of there or it needs to come out 17-Jan-19 01:17 PM which I am not looking forward to 17-Jan-19 01:20 PM Hm...but we are talking stuff in the turbine or heavy degassing? 17-Jan-19 01:23 PM I have no idea, it sat around for some years, so probably all of it 17-Jan-19 01:23 PM you can actually hear your turbo significantly? 17-Jan-19 01:23 PM ok my rotary vane pump also makes louder noises than it should... 17-Jan-19 01:33 PM not more than I should, but you can hear it, yes 17-Jan-19 01:56 PM turboloch 17-Jan-19 02:11 PM Well, if some time degassing doesnt work, it's teardown time! 17-Jan-19 04:03 PM or I just put another turbo in there 17-Jan-19 04:03 PM I should have something with CF63 laying about 17-Jan-19 04:31 PM @Applied_Ion you coming to the surplus place tomorrow to dig through old IBM silicon manufacturing stuff they should be getting in? 17-Jan-19 04:32 PM Turbo hitting the current and temperature limit and spooling down at work means there's either a leak or too much moisture. 17-Jan-19 04:33 PM Well time to break out the rga and start lookin at ratios... 17-Jan-19 04:33 PM Also @niklas that display interface for the IGM-400 is looking fantastic, is that just using like an arduino pro mini or something because I have like 10 of them I don't know what to do with :) 17-Jan-19 04:35 PM well yes, but I'm trying to get the turbo up enough so I can degas the RGA properly before I go on the witch hunt 17-Jan-19 04:35 PM Oh the no mans land of leak hunting 17-Jan-19 04:35 PM I feel bad for you 17-Jan-19 04:37 PM just turned up the heat on the heating wire 17-Jan-19 04:37 PM I'll see what happens in a few hours 17-Jan-19 04:41 PM @Conmega take lots of photos! Drink something for me. 17-Jan-19 04:45 PM @AdamMcCombs You just spray the joints with soapy water to find leaks right? ;P (trolololo, seriously don't do this) 17-Jan-19 04:47 PM Soapy helium? 17-Jan-19 04:47 PM no, acetone or ipa 17-Jan-19 04:48 PM and as @GigaSquirrel found out, don't suck IPA through molecular filters... 17-Jan-19 04:48 PM hehehe 17-Jan-19 04:48 PM whoops 17-Jan-19 04:50 PM XD 17-Jan-19 04:52 PM On the topic of leaky vacuum joints, I'm trying to find a leak on my SEM. Is there any risk in just going through each joint and hand tightening? Are there fancy joints with fragile gaskets or something that could get damaged? 17-Jan-19 04:52 PM no, but you can oversquish rubber seals 17-Jan-19 04:58 PM @Conmega I won't unfortunately be able to go tomorrow, got work. Weekends are really the only time I'd be able to make the drive, unless it's during some time that I would get a day off when the lab is closed. 17-Jan-19 05:07 PM Daaaaaamn 17-Jan-19 05:09 PM I think it would definitely be great to meet up there though, maybe even invite some of my friends in the area who are also doing vacuum and tech research to come along as well 17-Jan-19 05:11 PM next thing you know, they made an improvised vacuum and Hi-Power CON 17-Jan-19 05:14 PM That would be awesome lol 17-Jan-19 05:14 PM Not a bad idea 17-Jan-19 05:16 PM But do it in a few years, so I can attend, please. 17-Jan-19 05:18 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/E0agb68NnBu9SoniILiQmHQ1B8OKs-vhu-nXPmYbb1-6122E.png 17-Jan-19 05:18 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/CFrj8OpprN9ZdNLYLH7Dv1b9W2xhYr5q52OYh4D5U3-CC45C.png 17-Jan-19 05:18 PM I've been considering over the past couple of days if maybe I could start something like an amateur pulsed power group, name it like Amateur Pulsed Power or Amateur Pulsed Power Society or something (AMPP, AMP^2, AMP^2S, etc) not sure how to make superscript in chat but you get the idea lol. Need to have some relevant acronym lol 17-Jan-19 05:18 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/NXB2EZiUyBHD_vhLKJmwA66eJbiLTJU3yvUnTtfAO6-73569.png 17-Jan-19 05:18 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/v5JN2qAURoLldiYhP-q43EYgRV2ayJTuQwST2N4kkt-4F721.png 17-Jan-19 05:18 PM @Conmega Its doable... 17-Jan-19 05:19 PM is that...soapy water? 17-Jan-19 05:21 PM yup 17-Jan-19 05:21 PM on my sem 17-Jan-19 05:21 PM I had to put a ratchet strap over the gun chamber to keep it closed 17-Jan-19 05:21 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/pJBfWW1jMjRIi6x5xd9o3U-nSpejDnkNbqAe6Rtjky-EBF57.png 17-Jan-19 05:21 PM I hacked together a fitting to pressurize it. 17-Jan-19 05:26 PM Are you okay, Adam?...you don't sound like yourself. 17-Jan-19 05:35 PM This is geter done engineering 17-Jan-19 05:35 PM Also this was my first time finding a leak on my first SEM... So my methods were less developed 18-Jan-19 01:55 AM wow %) 18-Jan-19 01:55 AM yeah, vac tec is basically plumbing 18-Jan-19 01:57 AM sophisticated plumbing 18-Jan-19 01:58 AM Yeah pluming where everything matters 18-Jan-19 03:44 AM Morning! 18-Jan-19 03:45 AM Moin! 18-Jan-19 03:45 AM moin 18-Jan-19 03:48 AM https://vid.pr0gramm.com/2018/02/07/0c64c4a100f8e266.mp4 18-Jan-19 03:50 AM seagull scene from Nemo 18-Jan-19 06:47 AM yeah seems like I can pump the crap out of the system 18-Jan-19 06:47 AM been running now for 20h at 100°C and the turbo goes to 70krpm 18-Jan-19 06:48 AM thermal expansion has closed your leak, will be back once it gets <50°C 18-Jan-19 06:49 AM intermittent virtual leaks. the best kind of leaks! 18-Jan-19 06:52 AM unlikely, that part was never open 18-Jan-19 06:52 AM but I just opened the valve to the RGA and it does not spin down 18-Jan-19 06:52 AM ofc with best vacuum practice, juuuuust cracking the valve slightly not to vent the turbo too much 18-Jan-19 06:52 AM and then just opening the valve fully after it spun up again 18-Jan-19 06:54 AM ah, that reminds me... how would you guys go about cleaning/refurbishing heavily used and slightly rusted vacuum stuff? 18-Jan-19 06:57 AM sonicate for a while and then see 18-Jan-19 07:07 AM hm, 3.6*10^-6mbar I guess that's ok for a leaky system 18-Jan-19 07:09 AM hmmm, ultrasonic cleaning is a good idea, but what about the flanges... i thought about machining custom rotary abrasive tools to clean up the important surfaces, but not sure about that 18-Jan-19 07:09 AM how "clean" or "polished" do KF-parts have to be in order to be vacuumtight? 18-Jan-19 07:09 AM and yeah, e-6 sounds good 18-Jan-19 07:11 AM they can be pretty beat ime, but ideally they have no scratches orthogonal to the axis of the flange 18-Jan-19 07:11 AM meh, it is all metal sealed 18-Jan-19 07:11 AM it should be better than that 18-Jan-19 07:11 AM I want to see at least 10^-8 18-Jan-19 07:19 AM yeah, i want to see e-12, but i probably never will, at least with my equipment at home. XD 18-Jan-19 07:20 AM -12 is very hard 18-Jan-19 07:20 AM -11 is actually not too hard 18-Jan-19 07:22 AM sigh i have to run my turbo pump this year... it just sitting around is probably not the best thing... 18-Jan-19 07:29 AM I mean, our system was only pumped with ion pumps and TSPs 18-Jan-19 07:29 AM and it would regularily go into the -11 range 18-Jan-19 08:30 AM 10^{-11}mbar measured via ion getter pump current? 18-Jan-19 08:39 AM any cheap sources for SHV connectors (especially those rated for >= 20kV) out there? 18-Jan-19 08:41 AM ebay china? 18-Jan-19 08:42 AM yeah, but more specific? 18-Jan-19 08:42 AM "china" ehehhe 18-Jan-19 08:46 AM the 5kV-version is cheap on aliexpress https://ru.aliexpress.com/item/SHV-straight-plug-crimp-5000V-for-the-cable-50-5/720418093.html 18-Jan-19 08:47 AM yep 18-Jan-19 08:47 AM those 20kV versions are different 18-Jan-19 08:48 AM yeah, i know. i thought i saw them there, too, bit now i can find nothing 18-Jan-19 08:48 AM much longer ferrule 18-Jan-19 08:48 AM ok 18-Jan-19 08:48 AM yeah 18-Jan-19 08:48 AM ...just use 4 of the 5kV in series, that's 20kV too 18-Jan-19 08:49 AM heh yeah? 18-Jan-19 08:49 AM :3 18-Jan-19 08:50 AM so thats the trick! 18-Jan-19 09:00 AM https://www.aliexpress.com/item/Gd/32950414004.html 18-Jan-19 09:00 AM exactly what I needed, high voltage banana plug 18-Jan-19 09:06 AM wait, there is 20 kV SHV? 18-Jan-19 09:06 AM I thought the standard only went up to 5 or 10 18-Jan-19 09:06 AM Standard SHV connectors are rated for 5000 volts DC and 5 amperes, although higher-voltage versions (to 20 kV) are also available. 18-Jan-19 09:06 AM thanks, wikipedia 18-Jan-19 09:09 AM I literally have one sitting on my desk right now. We use them occasionally, though the 20kv ones are difficult and expensive to get 18-Jan-19 09:09 AM Kings Electronics Co makes a lot of the SHV connectors 18-Jan-19 09:11 AM https://www.mouser.de/ProductDetail/Radiall/R317072000?qs=sGAEpiMZZMukCeVMgJHkjN2WA19TAYR3tZb8yqc6kkY%3d That one's 10 kV 18-Jan-19 09:11 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20190118_121141-D4719.jpg 18-Jan-19 09:12 AM oh wow. that looks amazingly stupid :-D 18-Jan-19 09:12 AM took me a moment to realize where the cable even goes in 18-Jan-19 09:12 AM https://www.mouser.de/ProductDetail/Radiall/R317580000?qs=sGAEpiMZZMukCeVMgJHkjN2WA19TAYR3Kz8fgcNHpN8%3d also 10 kV 18-Jan-19 09:13 AM Yeah, this one is a 20kv series one. Cable goes into the right side lol 18-Jan-19 09:13 AM are there ones up to ~50kV? 18-Jan-19 09:13 AM powering a fusor through SHV would look so wrong but be really fun 18-Jan-19 09:14 AM I doubt it. At that point you are getting more into connectors you see for like Glassman power supplies 18-Jan-19 09:16 AM the "connector" on my glassman is a deep hole with a PL connector with the dielectric punched out 18-Jan-19 09:16 AM afaik SHV goes up to 20kV 18-Jan-19 09:16 AM and no, PL is not a valid option. never. not even for DC low voltage. 18-Jan-19 09:17 AM PL? 18-Jan-19 09:17 AM UHF 18-Jan-19 09:17 AM https://en.wikipedia.org/wiki/UHF_connector 18-Jan-19 09:17 AM I'm looking for pics of my PS right now 18-Jan-19 09:18 AM Oh, that's way different than the plugs for our supplies 18-Jan-19 09:19 AM https://www.fingers-welt.de/imghost/up/20180319_2319__87-123-203-92_small_photo2018-03-1923-17-43.jpg 18-Jan-19 09:19 AM https://www.fingers-welt.de/imghost/up/20180319_2321__87-123-203-92_small_photo2018-03-1923-17-48.jpg 18-Jan-19 09:20 AM Yeah, that's the style we have 18-Jan-19 09:20 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20190118_121936-10328.jpg 18-Jan-19 09:20 AM UHF is the abbreviation for germen "Ungeeignet für Hochfrequenz" (not for high frequencies) 18-Jan-19 09:21 AM more like "not suitable for high freq" 18-Jan-19 09:21 AM and they actually use it for high voltages... well, at least it's somewhat useful then XD 18-Jan-19 09:44 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1287-104F9.jpg 18-Jan-19 09:44 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1288-77EA2.jpg 18-Jan-19 09:44 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1290-82D26.jpg 18-Jan-19 09:44 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1286-2690F.jpg 18-Jan-19 09:44 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1289-54A1B.jpg 18-Jan-19 09:45 AM Is that from the salvage place, or your own stuff? 18-Jan-19 09:45 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1291-6D44E.jpg 18-Jan-19 09:45 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1293-9250A.jpg 18-Jan-19 09:45 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1290-4292B.jpg 18-Jan-19 09:45 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1292-347A7.jpg 18-Jan-19 09:45 AM Surplus place 18-Jan-19 09:45 AM Holy crap I need to get down there lol 18-Jan-19 09:45 AM starts crying 18-Jan-19 09:45 AM These 40 two stage supers are MASSIVR 18-Jan-19 09:45 AM There are 3 18-Jan-19 09:46 AM How much they asking lol 18-Jan-19 09:47 AM Afraid to ask to be honest haha 18-Jan-19 09:47 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1294-9876F.jpg 18-Jan-19 09:47 AM They got a lot of awesome stuff there it seems 18-Jan-19 09:48 AM pretty standard stuff 18-Jan-19 09:48 AM fitting into what I would expect from an old research lab 18-Jan-19 09:49 AM He said 750 for one of the massive pumps 18-Jan-19 09:49 AM Oh... Yeah that's waaaay outside my budget for a single part 18-Jan-19 09:49 AM I can get my accelerator up and running with plenty of diagnostics for that price 18-Jan-19 09:50 AM that's not bad 18-Jan-19 09:50 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1295-37698.jpg 18-Jan-19 09:50 AM Not bad if you have the money to spend lol 18-Jan-19 09:50 AM Found more stuff 18-Jan-19 09:51 AM still holding pressure, but the question is if the adsorber is fresh 18-Jan-19 09:51 AM 25 hours 250... 18-Jan-19 09:51 AM 250 bucks for a compressor with 25 hours on it. 18-Jan-19 09:51 AM Looks like he has two 18-Jan-19 09:51 AM yep I'll take one 18-Jan-19 09:51 AM AaaaAAAAAHHHH screaming intensifies 18-Jan-19 09:51 AM I may have to call and ask about selling my vacuum stuff and what he can offer. I gotta sell some parts to continue funding this build 18-Jan-19 09:52 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1296-FAF34.jpg 18-Jan-19 09:52 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1297-8695C.jpg 18-Jan-19 09:52 AM This is a cool little pump 18-Jan-19 09:54 AM hmm, 1.1e-6 mbar, I guess that's ok for now 18-Jan-19 09:56 AM Dry pump. Suppose that would be desirable. 18-Jan-19 09:56 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1298-E2A14.jpg 18-Jan-19 09:56 AM Ah crap that only does up to 2Mhz... I'd really like 13.56 Mhz... He has some larger RF gens but they require 3 phase uhg 18-Jan-19 10:01 AM WHAT THE HELL ARE MY EYES SEEING THERE 18-Jan-19 10:01 AM the CLX 10kW seem to need 3phase, too 18-Jan-19 10:03 AM where do I get a greencard? 18-Jan-19 10:04 AM yeah, I used a 100W PA when I did HF plasma experiments, it survived all my torture 18-Jan-19 10:04 AM I have a amat hf supply but the regulation is iffy at very low powers 18-Jan-19 10:04 AM and the cooling requirements for a chamber at high power get out of hand very quickly 18-Jan-19 10:05 AM @Pan Da no it has a 48V DC input in the back 18-Jan-19 10:06 AM ohhhhh, ok. nice! 18-Jan-19 10:07 AM most of the 3 phase stuff will run on 240V just fine, you just have to figure out which phases to use 18-Jan-19 10:07 AM And I think there is a 48VDC powersupply that's 3 phase to go with it lol 18-Jan-19 10:07 AM Ah OK I didn't know that sync... 18-Jan-19 10:07 AM lel, what a strange design 18-Jan-19 10:07 AM well, you have a rectifier and most stuff works off the DC link 18-Jan-19 10:07 AM but fans are usually AC in supplies that big 18-Jan-19 10:16 AM This dry pump for 250 is fair I think but it's also 3 phase... 18-Jan-19 10:16 AM I wonder if I can run on single phase. 18-Jan-19 10:18 AM you could just send all that 3phase stuff over to europe. we can use it as is 18-Jan-19 10:18 AM :-D 18-Jan-19 10:20 AM it's actually very annoying to us US 3phase stuff here depending on the voltage it used before 18-Jan-19 10:20 AM depends on what the pump uses internally 18-Jan-19 10:20 AM otherwise you can just retrofit a VFD 18-Jan-19 10:20 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1299-CACC3.jpg 18-Jan-19 10:20 AM Also these things. 18-Jan-19 10:20 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1300-6FB67.jpg 18-Jan-19 10:24 AM @sync i find american electrics very... hm, how to describe it... discomforting? 18-Jan-19 10:26 AM it works 18-Jan-19 10:26 AM but apart from that, yeah some things are done very strangely 18-Jan-19 10:28 AM i understand where some of it comes from... high leg delta for example... but i fail to see why it doesn't get updated to a more safe and sane system 18-Jan-19 10:29 AM cost 18-Jan-19 10:29 AM but high leg delta is not unsafer than anything else 18-Jan-19 10:29 AM what's really strange to me is having to run some water pipe everytime I want to put some wire somewhere 18-Jan-19 10:29 AM and not having 3 phase is pretty much state of the art in the EU now as well 18-Jan-19 10:33 AM depends on where you live. in germany most houses get 3phase, most flats get 1phase (even though the complex has 3phase) (except for the oven which is 3phase in every newer building i know of) 18-Jan-19 10:35 AM no, most new construction is now designed not to get 3 phase anymore 18-Jan-19 10:35 AM as no oven needs it 18-Jan-19 10:35 AM i have 3phase in my flat... big red CEE-connector in the middle of the wall :-D 18-Jan-19 10:35 AM and it is preferred by the supplier 18-Jan-19 10:35 AM as they can control loadsharing better than relying on the electrician to do it for them 18-Jan-19 10:36 AM what? where? 18-Jan-19 10:36 AM most of europe in new construction zones 18-Jan-19 10:36 AM it depends where in germany you are but it's becoming the norm now 18-Jan-19 10:36 AM because realistically it does not make any sense to provide 3 phase to residential homes 18-Jan-19 10:39 AM but you need to run the big runs 3phase anyways, so why not deliver it to the houses... 18-Jan-19 10:39 AM it saves copper to the house and you can control what phases the house gets 18-Jan-19 10:39 AM and you can size your transformer better 18-Jan-19 10:40 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1302-C1818.jpg 18-Jan-19 10:40 AM Big old bendy boy 18-Jan-19 10:41 AM as you can expect a higher average utilization 18-Jan-19 10:42 AM @Conmega is that open port threaded on the outside? and the thing on the right looks like a post for tying down a ship. 18-Jan-19 10:43 AM cries alongside @GigaSquirrel 18-Jan-19 10:43 AM What are those in the box, branded fujikin? 18-Jan-19 10:43 AM @sync hmmm... ok, sounds plausible i guess... but i hadn't heard of that Oo 18-Jan-19 10:43 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1303-4A715.jpg 18-Jan-19 10:43 AM Not theaded.. 18-Jan-19 10:43 AM It's weird 18-Jan-19 10:43 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1304-9EA9C.jpg 18-Jan-19 10:44 AM they are gasvalves 18-Jan-19 10:44 AM conical inside, strangely ribbed outside... what.? 18-Jan-19 10:44 AM Yes 18-Jan-19 10:44 AM for a flat manifold 18-Jan-19 10:44 AM I'm getting the KF bend piece probably lol 18-Jan-19 10:44 AM And maybe this ion pump 18-Jan-19 10:44 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1245-8374B.jpg 18-Jan-19 10:45 AM F, not KF (i think) 18-Jan-19 10:46 AM Hey I needed one of these! 18-Jan-19 10:46 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1305-E4568.jpg 18-Jan-19 10:47 AM ahh, ok. nice 18-Jan-19 10:47 AM Surfaces are beat but I assume you can clean them up? Lap them? 18-Jan-19 10:47 AM yeah you can do that 18-Jan-19 10:47 AM ideal is turning them, as the finish is not incredibly important 18-Jan-19 10:47 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1306-6C3AE.jpg 18-Jan-19 10:47 AM but the direction of the groove 18-Jan-19 10:47 AM I would not pay 20 bux for that bendy 18-Jan-19 10:47 AM but I guess it is fair 18-Jan-19 10:49 AM it's not a bad price 18-Jan-19 10:49 AM if i had no cheap sources and needed one, that would be a brilliant deal 18-Jan-19 10:52 AM Cheapest on ePay seems to ussually be 40-50 shipped... ... 18-Jan-19 10:52 AM yeah you have to look around for a while but they come up pretty often 18-Jan-19 10:52 AM I have a drawer full of new ones I got off ebay over some time 18-Jan-19 10:52 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1309-1E6A3.jpg 18-Jan-19 10:52 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1310-5E473.jpg 18-Jan-19 10:52 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1308-AF10A.jpg 18-Jan-19 10:53 AM a mass flow controller! 18-Jan-19 10:54 AM two! 18-Jan-19 10:54 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1311-CB4C1.jpg 18-Jan-19 10:54 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1312-AF608.jpg 18-Jan-19 10:54 AM and oh my i want to be there... 18-Jan-19 10:56 AM Damn that shop is nice xD really want those flow controllers ^^ 18-Jan-19 10:58 AM Yea I was thinking abiut the controllers... The connectors are a little beat tho 18-Jan-19 10:58 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1313-74ADF.jpg 18-Jan-19 10:58 AM Hard to see I suppose 18-Jan-19 10:59 AM yeah the nipples are not cheap as well 18-Jan-19 10:59 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1314-613D4.jpg 18-Jan-19 11:00 AM controllers are pretty cheap on ebay tho 18-Jan-19 11:01 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1316-492AD.jpg 18-Jan-19 11:01 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1315-E59E4.jpg 18-Jan-19 11:01 AM Found a weird boi 18-Jan-19 11:02 AM that's a pretty old style 18-Jan-19 11:02 AM I think it is supposed to fit into the space where those swagelok round pneumatic valves would fit in 18-Jan-19 11:03 AM Hm haven't been looking long, I guess they pop up from time to time @sync Those I found were not really cheap ^^ 18-Jan-19 11:04 AM they are always around for around 50-100 bux, which is not bad 18-Jan-19 11:04 AM less if you spend the time to wait for a cheaper one 18-Jan-19 11:05 AM So these mass flows... If the connectors have damage on them they are pretty much done or? I'm not really familiar with the connectors on these gas feeds that are common 18-Jan-19 11:05 AM Thanks for the tip, I didn't really know what is considered expensive and what not ^^ 18-Jan-19 11:05 AM there are some pretty annoying ones as well that need various strange voltages 18-Jan-19 11:05 AM Like the shiny roundish surface. 18-Jan-19 11:06 AM cajon is the fitting 18-Jan-19 11:06 AM really nice system 18-Jan-19 11:06 AM if you cannot get them out of the mfc body it starts to get ugly 18-Jan-19 11:06 AM they work pretty well even if damaged like CF but it is not ideal 18-Jan-19 11:07 AM Ah OK. They are welded so... 18-Jan-19 11:07 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1320-66E26.jpg 18-Jan-19 11:07 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1319-0E12B.jpg 18-Jan-19 11:08 AM those gauges often don't like rough handling... i have several of them with broken filaments or even electrodes 18-Jan-19 11:08 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1321-F19A0.jpg 18-Jan-19 11:08 AM Massive cajons 18-Jan-19 11:08 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1323-F7314.jpg 18-Jan-19 11:08 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1324-2D1E9.jpg 18-Jan-19 11:08 AM Omg right above my head are NW160 seals... I need one for my turbo... LOL 18-Jan-19 11:15 AM XDDDD 18-Jan-19 11:15 AM I will stop looking for a while, I can't take it anymore. 18-Jan-19 11:27 AM There are quite a few new NW160 seals here if anyone needs one lol 18-Jan-19 11:27 AM I wish there were other sizes 18-Jan-19 11:27 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1325-AF451.jpg 18-Jan-19 11:27 AM Also caps 18-Jan-19 11:27 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1326-7437A.jpg 18-Jan-19 11:51 AM An ion pump with out magnets is an expensive hunk of vacuum chamber that outgasses... 18-Jan-19 11:51 AM @Conmega 18-Jan-19 11:51 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190118_033216-6EF81.jpg 18-Jan-19 11:51 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190118_032136-ABECD.jpg 18-Jan-19 11:51 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190118_030947-6E9A5.jpg 18-Jan-19 11:59 AM Ah hah didn't even think of or realize the whole magnets thing thanks! I didn't get it anyway. I just got out of the place. Got quite a few bits and bobs. Will post photos later of what I got. 18-Jan-19 11:59 AM I have to get home and changed to go into work to pay for the junk :P 18-Jan-19 12:01 PM They can still be fun for things though. I'm kinda growing to really not like them though, kinda a massive pain. 18-Jan-19 12:07 PM yeah the shape is also not very useful 18-Jan-19 12:10 PM I mean unless you want a vacuum resivor for something 18-Jan-19 12:26 PM yeah if I get back into messing with vacuum things I need to get my KF40 beerkeg out again 18-Jan-19 01:37 PM I mean it has a somewhat sizable center area... so theoretically maybe use it for sputtering area? I mean it has a HV pass through already so it might be handy 18-Jan-19 01:37 PM I also have that massive CF valve that I think is the same size... 18-Jan-19 01:37 PM but either way its not going anywhere fast and its 50 bucks 18-Jan-19 01:37 PM OHH 18-Jan-19 01:37 PM could make a chandelier out of it LOL 18-Jan-19 01:37 PM https://media.discordapp.net/attachments/513115950501855261/535892394135257089/DSC_1245.jpg 18-Jan-19 01:37 PM chandelier material right? 18-Jan-19 01:37 PM :P 18-Jan-19 01:42 PM with plasma flames! 18-Jan-19 01:42 PM and hung from the ceiling on a massive CF tube 18-Jan-19 03:16 PM I wish I got that dry pump but to be honest I'm not sure if it'll run on single phase and I have the RV12 and a turbo... I should be fine :) 18-Jan-19 03:16 PM I just need to get a few more specific pieces off the ePay and I should have enough for a chamber 18-Jan-19 03:16 PM and by specific pieces I mean like CF 6" to NW160 for the turbo. 18-Jan-19 03:16 PM maybe a CF 6" elbow too 19-Jan-19 04:16 AM It's always those specific bits of plumbing that get me. I find a great deal on a baratron gauge, or whatever, then I have to pay more than that for the adapters and whatnot. 19-Jan-19 05:13 AM I was looking for mass flow controllers on ebay, but a lot of the ceaper ones are really old. Is it a bad idea to buy them if they are 20+ years old? 19-Jan-19 05:15 AM not really 19-Jan-19 05:15 AM if you're in germany look out for the Burkert 8711 ones, they're amazing 19-Jan-19 05:23 AM Yep, from germany. What's so special about them? Easy to interface? 19-Jan-19 05:30 AM easy to interface and they also take RS232 to configure everything 19-Jan-19 05:30 AM time constants, integrator, feedback for pretty much everything, 2 or 3 digital inputs which can be used to activate certain actions 19-Jan-19 05:30 AM and actually pretty cheap, often <50€ 19-Jan-19 05:34 AM Oh that sounds nice! 19-Jan-19 05:34 AM And the biggest plus 19-Jan-19 05:34 AM they're sooo shiny 19-Jan-19 05:34 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190119_143521-9FDDE.jpg 19-Jan-19 05:41 AM Haha ok that's true 19-Jan-19 10:22 AM Yea I wish those were easily obtainable here in the US. 19-Jan-19 12:56 PM your wish is not accepted, you have too much nice shops nearby 19-Jan-19 12:56 PM 19-Jan-19 01:06 PM haha, yeah 19-Jan-19 11:36 PM Why does it seem like Germans always get the coolest stuff? 19-Jan-19 11:37 PM has an electron microscope 19-Jan-19 11:37 PM I'm going to Germany for my honeymoon, and I'm bringing empty suitcases so I can stock up on sweet German tools and equipment. 19-Jan-19 11:49 PM Or buy a cool German flight case 20-Jan-19 12:34 AM On the scale of sketchy vacuum blanks I have used this probably rates about a 6 or 7 20-Jan-19 12:34 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190120_003308-21264.jpg 20-Jan-19 12:34 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190120_003305-30C59.jpg 20-Jan-19 12:34 AM Breaking vacuum went about as well as you would expect 20-Jan-19 12:34 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190120_003627-E6BFB.jpg 20-Jan-19 01:28 AM @piGuy We have some great offers on some things here, but lacking any surplus stores I wouldn't go to germany for shopping... 20-Jan-19 01:28 AM Honeymoon, nice! Tech-interested partner? If yes I might know some places you might want to visit 20-Jan-19 01:33 AM On the area of pulsed power, I just spotted this: 20-Jan-19 01:33 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-1D873.png 20-Jan-19 01:33 AM Is that a spark gap in his desk? 20-Jan-19 01:33 AM Looks like it has some form of fluid input/output 20-Jan-19 01:34 AM sure looks like it! 20-Jan-19 01:34 AM maybe an oil tester? 20-Jan-19 01:34 AM No idea 20-Jan-19 01:35 AM mike doesn't seem to do much pulsed power 20-Jan-19 02:13 AM Yeah, but still. 20-Jan-19 02:13 AM Btw. MORNING! \o/ 20-Jan-19 02:17 AM Moin! 20-Jan-19 03:14 AM moin yawns 20-Jan-19 03:15 AM Whey, it's a panda! 20-Jan-19 03:16 AM not yet. at the moment it's a sleepy mess. 20-Jan-19 03:16 AM give me ~3 or 4 hours to fully boot... 20-Jan-19 03:17 AM throws some coffee in your face 20-Jan-19 03:30 AM hit! goes down 20-Jan-19 03:30 AM (maybe slightly offtopic...) 20-Jan-19 03:32 AM yeah, and once we go into #off-topic-thats-sometimes-on-topic adam will complain about us being too on topic 20-Jan-19 03:32 AM Hey that's off topic get to the right channel 20-Jan-19 07:01 PM jesus h christ... I was trying to figure out why my new code on the flow bench wasnt working... the damn little start switch I was using came unsoldered 20-Jan-19 07:51 PM https://vacaero.com/information-resources/vacuum-pump-technology-education-and-training/957-the-rv-vacuum-pump-is-21.html 20-Jan-19 08:06 PM The title makes it sound like rotary vane pumps have only been around for 25 years. I was like "no way!" 20-Jan-19 09:43 PM neat! 21-Jan-19 04:18 AM They should be giving away one or something. There are children in some countries that don't have vacuum pumps. 21-Jan-19 10:34 AM The tungsten filament for my SEM costs $185 each 21-Jan-19 10:34 AM I think that might be the most expensive filament in the world 21-Jan-19 10:44 AM wow 21-Jan-19 10:44 AM whats thefilament type? 21-Jan-19 10:48 AM Unobtainium, apparently. 21-Jan-19 11:00 AM Just tungsten. It's in a pre-centered cartridge with the wehnelt cup and everything. If you reuse the cartridge and replace just the tungsten, it only costs $150. 21-Jan-19 11:05 AM ah ok "only" 21-Jan-19 11:06 AM hehe, yeah it's a bargain! 21-Jan-19 11:07 AM thing is you dont have to center the filament to the hole in the cup? 21-Jan-19 11:09 AM No it's pre-centered. To replace the filament for $150 you have to send the assembly to someone to do it. 21-Jan-19 11:23 AM ok makes sense 21-Jan-19 11:23 AM is it a modern desktop sem? 21-Jan-19 11:46 AM Yeah 21-Jan-19 01:28 PM Yeah you can build your own 21-Jan-19 03:16 PM what defines a "Desktop SEM" anyway lol 21-Jan-19 03:16 PM how big of a desk are we talking? 21-Jan-19 03:41 PM Any desk that can handle 200lb worth of gear on top of it. 21-Jan-19 03:41 PM ooh I think I may have found a loose fitting! 21-Jan-19 03:41 PM That's a folding table... 21-Jan-19 03:41 PM Also I have computers that fill that role, litterally haha 21-Jan-19 03:41 PM https://i.imgur.com/OW0Z6P3.jpg 21-Jan-19 03:48 PM drop screw deep into bowels of SEM, try to convince myself I didn't need it anyways... 21-Jan-19 04:36 PM that's never good 22-Jan-19 10:57 PM nope 22-Jan-19 11:51 PM don't worry guys, I found it. 22-Jan-19 11:52 PM Ah so you have learned to play SEMchinko 22-Jan-19 11:52 PM The version of plachico where you find the normal distribution of places to lose screws 23-Jan-19 01:24 AM yawn 23-Jan-19 01:24 AM Good morning everyone! 23-Jan-19 01:47 AM moin! 23-Jan-19 03:09 AM moin 23-Jan-19 03:48 AM Morning! 23-Jan-19 03:48 AM @AdamMcCombs you mean Pachinko? 23-Jan-19 01:49 PM did anyone here try doing his own copper gaskets ? 23-Jan-19 01:54 PM did one for swagelok 23-Jan-19 02:07 PM or VCR? 23-Jan-19 02:07 PM dunno, the genderless one that needs gaskets 23-Jan-19 02:38 PM ok, and some bigger for CF? 23-Jan-19 02:39 PM njet, at least not me 23-Jan-19 03:12 PM I made one when we did not have a cf16 but I don't think it is worth the hassle 23-Jan-19 03:14 PM yeah, how much effort was it? did you cast the copper and then smoothed/polished it? did it seal well? 23-Jan-19 03:14 PM because in germany copper gaskets in CF sizes are rather rare and expensive 23-Jan-19 03:16 PM casting copper is a mayor pain in the lower back 23-Jan-19 03:16 PM and you won't get it clean enough to seal anything 23-Jan-19 03:16 PM most reliable way would be to take some 2mm Cu sheet and stamp out the rings 23-Jan-19 03:16 PM that's gonna be really wasteful 23-Jan-19 03:19 PM no, I cut it out of a sheet of copper 23-Jan-19 03:19 PM but CF gaskets are not rare or expensive in germany 23-Jan-19 03:19 PM the rings are 1-3 €per piece and can be reused to a certain extent 23-Jan-19 03:19 PM and with all the work you ideally should do to them they are almost as expensive as bought ones 23-Jan-19 03:20 PM +1 23-Jan-19 03:52 PM For custom cf stuff that they don't want to spin dies for they just cnc sheet copper 23-Jan-19 03:52 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190122_232459-B35B1.jpg 23-Jan-19 03:52 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190122_232442-56027.jpg 23-Jan-19 03:52 PM Doing a bit of vlave work on my SEM. I used to have to kick the valve open with a wrench. Not great when this valve not moving could cause a dif pump crash 23-Jan-19 04:35 PM God damn a turbo pump makes a nasty and terrifying noise if you slam it to atmosphere when it's at +20000rpm 23-Jan-19 04:35 PM gota love witnessing firmware bugs 23-Jan-19 04:36 PM Ouch 23-Jan-19 04:36 PM Whose pump is it? 23-Jan-19 04:36 PM Works 23-Jan-19 04:36 PM Nice 23-Jan-19 04:36 PM Edwards? 23-Jan-19 04:37 PM And there's a reason why there's a dedicated (and abused) firmware R&D pump system 23-Jan-19 04:37 PM Pfeiffer 23-Jan-19 04:37 PM Is it intact? 23-Jan-19 04:38 PM Suprisingly it seems so 23-Jan-19 04:38 PM I'm also very happy for various reasons. 1. It's not my firmware. 2. I was not the person testing it 23-Jan-19 04:39 PM Well that's good 23-Jan-19 04:39 PM Just happened to be in the R&D lab at the right time 23-Jan-19 04:39 PM I feel like this is a clap hands this is why you interlock moment 23-Jan-19 04:40 PM Everything is firmware based 23-Jan-19 04:40 PM the pfeiffer controller does not even have inputs to make it have hardware interlocks from what I recall reading the manual 23-Jan-19 04:40 PM That's unfortunate 23-Jan-19 04:40 PM Yes. 23-Jan-19 04:40 PM I also wish that there was e-brake or somthing for turbos 23-Jan-19 04:40 PM waiting for them to spin down in vacuum takes time which is annoying when you are testing pumping logic. 23-Jan-19 04:42 PM Can't just fudge the inputs? 23-Jan-19 04:43 PM Oh we can, and do. But the logic dislikes the pump being spinning when it does certain things. 23-Jan-19 04:43 PM and I want to avoid slamming a spinning pump to full or partial atmospheric pressure. 23-Jan-19 04:43 PM Sometimes I gripe that my work mostly is designing wiring harnesses and test equipment for production. 23-Jan-19 04:43 PM But it could be worse, I could be the dude writing firmware for the thing. 23-Jan-19 04:43 PM But anyway, this is likely the only group that can appreciate the horror of hearing the loud snap of a KF40 solenoid valve and then a turbo making loud angry sounds. 23-Jan-19 05:18 PM the pumps are rated for sudden atm venting 23-Jan-19 05:18 PM larger ones even feature stress risers should they crash on venting/whatever that the rotor breaks apart and crashes into the stator in a controlled fashion 23-Jan-19 05:34 PM but yes, the sound is alarming the first few times 23-Jan-19 05:34 PM i like the SMACK! when you vent a 1000l+ pump suddenly 24-Jan-19 01:26 AM Good morning everyone! 24-Jan-19 01:30 AM moin 24-Jan-19 02:57 AM \o/ 24-Jan-19 03:38 AM whey, this is going to be fun 24-Jan-19 03:38 AM got a letter from customs to go and get the preamp I ordered for my neutron detector 24-Jan-19 03:38 AM something about it not conforming to the rules of trade with the eu 24-Jan-19 04:12 AM XDDDDDDDDDDDDDDD 24-Jan-19 04:12 AM Does it have anything special or radioactive? 24-Jan-19 04:15 AM not that I know of 24-Jan-19 04:15 AM but it comes from israel, maybe that rises some red flags? 24-Jan-19 04:15 AM dunno, will find out in a couple of hours 24-Jan-19 05:24 AM I received yestarday my miniature photoflash transformers and they came from israel too, never had problems with that. 24-Jan-19 07:22 AM oh, the ones from ebay? 24-Jan-19 07:22 AM how are they 24-Jan-19 07:22 AM I can't believe they are so expensive 24-Jan-19 07:31 AM - relativly speaking 24-Jan-19 08:00 AM everything went fine, I got the amp with no issues ^^ 24-Jan-19 10:44 AM What was their concern? 24-Jan-19 10:44 AM I really don't know 24-Jan-19 10:44 AM didn't ask, was just happy to get it 24-Jan-19 10:44 AM usually you get called into the customs office when there is no receipt so they don't know how much to charge 24-Jan-19 10:44 AM but there was one in an extra envelope glued to the package, but not even opened 24-Jan-19 10:44 AM at least I got a chance to ask how high customs will be for the hornets 24-Jan-19 10:44 AM and just 19% taxes, regardless of the price of the gauges 24-Jan-19 10:44 AM which is great IMO 24-Jan-19 11:00 AM 24-Jan-19 02:27 PM Can't wait for my gallon of 99% Anhydrous Isoproponal to get here <3 Always hate worrying about running out with those little bottles lol. Of-course I would have ordered 4 gallons if I could afford it at the time. Next time though... 24-Jan-19 02:43 PM is it hard to get IPA in the usa? 24-Jan-19 02:43 PM https://www.amazon.com/Isopropyl-Alcohol-Grade-99-Anhydrous/dp/B01KK014F4/ref=sr_1_6_a_it?ie=UTF8&qid=1548369825&sr=8-6&keywords=isopropyl+alcohol+99.9 24-Jan-19 02:43 PM No LOL 24-Jan-19 02:44 PM ah, ok 24-Jan-19 02:44 PM would be surprised if it was 24-Jan-19 02:48 PM my inner metalorganic chemist starts cringing by the use of "anhydrous" 24-Jan-19 02:48 PM Yea I don't need it to be "anhydrous" lol I just need 99% 24-Jan-19 02:49 PM yeah all fine, in normal comparison its probably "anhydrous", just me being pedantic 24-Jan-19 02:49 PM yeah, nothing is worse than the yellow soup from the hardware store 24-Jan-19 02:49 PM you probably make everything dirtier than before with it 24-Jan-19 05:24 PM Easy way to get 99 is to grab 195 proof and store it on a bed of 3A molecular seives 24-Jan-19 05:24 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190124_042945-BBBF2.jpg 24-Jan-19 05:24 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190124_044020-B1E62.jpg 24-Jan-19 05:24 PM I got tired of dealing with NPT vacuum leaks. So I just used JB weld instead of pipe tape or dope 24-Jan-19 05:34 PM oh jeez... the next person to want to remove that is going to HATE your guts LOL 24-Jan-19 05:34 PM also this is why you get a big enough compressor, then you don't care about little leaks :) 24-Jan-19 05:34 PM oh oops you did say VACUUM leaks 24-Jan-19 05:34 PM huh ok 24-Jan-19 05:34 PM this is why you get a big enough vacuum pump* ;) 24-Jan-19 08:44 PM Yeah vacuum pump and conductance dont work like that 24-Jan-19 10:39 PM The person dismantling that next time will probably still be him. 24-Jan-19 10:39 PM yup 24-Jan-19 10:39 PM It was originally epoxied and some one removed it and put teflon tape in 24-Jan-19 10:39 PM XD 24-Jan-19 10:39 PM How come npt is used for vacuum? 24-Jan-19 10:40 PM I wonder the same thing 24-Jan-19 10:40 PM This was in the 70s 24-Jan-19 10:40 PM That explains a lot. 24-Jan-19 10:40 PM So like I guess... But still 24-Jan-19 10:40 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190124_180955-0CFC1.jpg 24-Jan-19 10:41 PM Keep calm and jb-weld on. 24-Jan-19 10:41 PM You can see an original epoxy joint on the right 24-Jan-19 10:42 PM The redish stuff? 24-Jan-19 10:42 PM yup 24-Jan-19 10:42 PM What are the things to the sides, valves? 24-Jan-19 10:47 PM Yeah the one on the right is the roughing valve from pump 2 on the SEM and the one on the left is the leak valve 25-Jan-19 12:51 AM moin 25-Jan-19 01:40 AM mornin! 25-Jan-19 01:43 AM Moin! 25-Jan-19 01:43 AM moin 25-Jan-19 01:43 AM Evening 25-Jan-19 02:42 AM Daylight savings! \o/ 25-Jan-19 03:50 AM moin 25-Jan-19 03:52 AM Woohoo, it's a panda 25-Jan-19 03:58 AM offers bamboo 25-Jan-19 04:02 AM Yes, please feed him so I won't have to make dinner tonight 25-Jan-19 04:20 AM Moin 25-Jan-19 04:21 AM Moin! 25-Jan-19 07:55 AM yey 27-Jan-19 02:03 AM good morning everyone \o/ 27-Jan-19 02:12 AM https://tenor.com/view/k08c-good-morning-gif-8431458 27-Jan-19 03:49 AM Moin! \o/ 27-Jan-19 02:42 PM helloo 27-Jan-19 02:42 PM I can hear everyone 27-Jan-19 02:42 PM in german 27-Jan-19 02:42 PM :PPPPPPPPPPPPPPPPPPPPPPP 28-Jan-19 12:39 AM Joined the server. 28-Jan-19 12:53 AM moin 28-Jan-19 01:18 AM Moin moin! 28-Jan-19 01:20 AM moin 28-Jan-19 01:22 AM Meine Deutsch ist nicht sehr gut aber ich bin leben auf Bremen 28-Jan-19 01:37 AM unser aller deutsch ist nicht so gut 28-Jan-19 01:41 AM deutsch ist nicht so gut. 28-Jan-19 01:41 AM Moin! 28-Jan-19 01:44 AM moin 28-Jan-19 01:48 AM I am Physicist, I did a Master in Beam Plasma Technologies and I am doing my PhD in Electron Beam induced chemical reactions 28-Jan-19 01:48 AM I am happy to be here, I have no so much experience in projects out of the academia but I want to start soon with my own Plasma sources at homme 28-Jan-19 01:48 AM I made in the past a small Plasma jet at home... 28-Jan-19 01:50 AM Awesome! 28-Jan-19 01:51 AM Welcome! 28-Jan-19 01:51 AM I am going to have to quiz you on ebid at some point 28-Jan-19 01:51 AM Im actually just setting up my STM/FEG tip etching stuff right now so im not going to be getting around to getting a gis setup right now but im still interested 28-Jan-19 02:10 AM Thank you very much, currently I am working in the FEBID community, I will happy to collaborate! 28-Jan-19 04:17 AM My research project is about EBID (Electron Beam induced Deposition) of metal-organic precursors for semiconductor manufacturing 28-Jan-19 04:30 AM organic semiconductors? 28-Jan-19 04:30 AM sounds sexy 28-Jan-19 04:30 AM oh no, probably not 28-Jan-19 04:30 AM what for deposits? 28-Jan-19 05:33 AM Now I am working, mainly with Iron Pentacarbonyl, Copper acetylacetonate and Cobalt acetylacetonates. 28-Jan-19 05:45 AM okay, simply said your evaporating it and then decompose it with an ion beam in the gas phase for deposition? 28-Jan-19 08:10 AM Depends, most of the time we sublimate the precursor in powder state over a gold coated silicon plate, then, we irradiate it with a low energy Electron-Beam 28-Jan-19 08:11 AM Yeah I'll stick to my crucible and heater 28-Jan-19 08:11 AM What instrument are you using? 28-Jan-19 08:12 AM The aim of the low energy Electron Beam is that in FEBID though the primary electrons are over kV range, the real chemical process occur because of the scattered electrons running at low energy range 28-Jan-19 08:12 AM How your crucible is heated? 28-Jan-19 08:14 AM Oh so improving resolution by decreasing the energy of the secondary electrons? 28-Jan-19 08:14 AM Thus r2 getting a lot better for the localization of deposition? 28-Jan-19 08:14 AM Resistively. Just talking about a standard mdc gis or the like 28-Jan-19 08:25 AM What we are studying more closely is how secondary electrons control the chemical reactions and the dependence of the mechanistic of such reaction because of de energy of the secondary electrons 28-Jan-19 08:25 AM I was thinking to design and build a laser driven crucible using a laser controlled by PWM pointing over one plate connected to the crucible 29-Jan-19 12:52 AM What are the benefits of the laser heating? 29-Jan-19 12:52 AM (sounds super mad-scientisty but awesome, in any case XDD) 29-Jan-19 02:24 AM does anyone have a similiar diffusion pump and maybe know how much oil is needed? 29-Jan-19 02:24 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190129_111848__01-5CF16.jpg 29-Jan-19 02:24 AM haven't found any information with the catalog number yet 29-Jan-19 02:25 AM good rule of thumb is to fill it to 50% below the foreline 29-Jan-19 02:25 AM but in my experience it is not very ciritical 29-Jan-19 02:27 AM Thats a massive amount of oil for that pump 29-Jan-19 02:27 AM Assuming the the flanged out bit at the bottom of the pump is the heater and that it stops there 29-Jan-19 02:28 AM hm ok, also have to find out how to remove the inner jet part, since there is a butterfly valve welded on top (yeah probably removable, but have to find out) 29-Jan-19 02:28 AM but would it make sense to build a pump like that? That's basically dead volume, isn't it? 29-Jan-19 02:29 AM They could need the room to do something odd internaly on the stack 29-Jan-19 02:29 AM If you pull the stack out you should be able to see a line on it that the oil usually went up to 29-Jan-19 02:30 AM something odd like what? 29-Jan-19 02:30 AM just curious 29-Jan-19 02:30 AM Multiple chambers for varying jet volumes 29-Jan-19 02:31 AM oh, ok 29-Jan-19 02:31 AM didn't know that's a thing 29-Jan-19 02:32 AM This is a jet I pulled to clean, you can see the oil fill line 29-Jan-19 02:32 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/7LE0Rx-WaBEXggmjdVy8etQJECsB3SduJctxpl-lSY-47B16.png 29-Jan-19 02:32 AM Better pic 29-Jan-19 02:32 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/YWsuTYGL5WWR9tjHDIhT-lenJJ3qKJaJhJcrezgjqx-2A488.png 29-Jan-19 02:32 AM That big jet is the fore line booster, gigabecquerel is right though its odd that there is is so much space between the bottom of it and the oil 29-Jan-19 02:32 AM I guess it is pretty close to half though 29-Jan-19 02:32 AM This is a fun one 29-Jan-19 02:32 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Yfrd6F91vCr8RWIa3RYxIasfAcuv_GP0SUYTXiONUS-A8EA0.png 29-Jan-19 02:37 AM and that's why you use Si based oils 29-Jan-19 02:37 AM Cant use Si oil if you are trying to analyze Si... 29-Jan-19 02:37 AM That looks like rp oil back streaming though 29-Jan-19 02:39 AM oof 29-Jan-19 02:39 AM The scope was a part out so it wasn't a big deal 29-Jan-19 02:41 AM it's jus that cleaning diff pumps can be a real pain 29-Jan-19 02:41 AM Yup 29-Jan-19 02:41 AM also for thin films I think Si oil is not always the best option, since contamination by Si oil can't be plasma cleaned away without residuals 29-Jan-19 02:41 AM been there, done that, but I'm guessing mine was just vented and not run for hours with rp oil in it 29-Jan-19 02:42 AM Yeah si oil is a pain to clean. Santovac is a thing for a reason 29-Jan-19 02:42 AM I want some Santocvac 5P :c 29-Jan-19 02:42 AM without paying for it 29-Jan-19 02:42 AM Yeah its good stuff 29-Jan-19 02:42 AM I cant help you there 29-Jan-19 02:43 AM Its also why I recover it if it looks good 29-Jan-19 02:43 AM I havent paid for DP oil yet for myself 29-Jan-19 02:43 AM lucky one 29-Jan-19 02:43 AM >.< 29-Jan-19 02:43 AM well @GigaSquirrel lets see what comes in a month or so :p 29-Jan-19 02:43 AM Yeah about cleaning DPs? 29-Jan-19 02:43 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/WG25zhKcndOqEkJgazHiHMljCiXKc9u7NqEsDysTio-E29E3.png 29-Jan-19 02:44 AM never got mine that clean, gave up after ~30 min with steel wool 29-Jan-19 02:44 AM Baffles are fun to clean 29-Jan-19 02:44 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IvKIEKydGf1zvzSHYmfD1_82wExLBLeGkF6UnlrDzj-61C36.png 29-Jan-19 02:44 AM Hanging a DP in this environment is even more fun 29-Jan-19 02:44 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/44Bf8aH7CZZCvrRjlPR4VeilYg1nqA_xS0Et_tsAGg-875C8.png 29-Jan-19 02:49 AM there are some things I don't envy you for on your job 29-Jan-19 02:50 AM I mean I dont have to clean a dp that well 29-Jan-19 02:52 AM but you do it for fun? 29-Jan-19 02:52 AM Wont have to clean it again as soon 29-Jan-19 02:52 AM When uptime is king... 29-Jan-19 02:53 AM ah, yes 29-Jan-19 02:55 AM *and you have scheduled downtime 29-Jan-19 02:56 AM "The pump is allowed be broken on the following dates:" 29-Jan-19 02:56 AM for real 29-Jan-19 02:56 AM Its when you dont have scheduled downtime that things get fun. 29-Jan-19 02:58 AM I can only imagine 29-Jan-19 02:59 AM Oh I can spend 500$ in fedex and get the pump tomorrow? Yes please 29-Jan-19 02:59 AM Actually have been there 29-Jan-19 02:59 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/zuAsN8lJWimaASmpWxqqf5IPSvb1ehXlJWvmheauPf-1F08A.png 29-Jan-19 03:04 AM ok, that I actually imagine to be quite fun 29-Jan-19 03:04 AM Yeah over night and same day logistics is a party 29-Jan-19 03:04 AM just not on your dime 29-Jan-19 03:04 AM It's why you send someone at your favorite vendors a gift card every so often 29-Jan-19 03:08 AM When you start using currier air service is when you know that stuff has gone seriously sideways 29-Jan-19 03:08 AM I can do same day logistics on most things for west coast united states at this point 29-Jan-19 03:10 AM and how about cheap and slow shipping of... let's say a SEM to europe? ^^ 29-Jan-19 03:11 AM I have a friend who has made the "i need a plane" call and I want to get to that level 29-Jan-19 03:11 AM Well I never said that any of this was cheap 29-Jan-19 03:11 AM In fact its quite the opposite 29-Jan-19 03:11 AM of course it is for fast shipping 29-Jan-19 03:12 AM Its really fun when you call some logistics company and the response back is call this number and ask for x, they will know how to deal with you 29-Jan-19 03:12 AM Or when the options are press 1 for Air special logics, 2 for ground special logistics, 3 for all other special logistics needs 29-Jan-19 03:12 AM Like overnighting a microscope to Canada. That was a 3 29-Jan-19 06:06 AM XDDDD 29-Jan-19 08:19 AM moin! 29-Jan-19 08:19 AM Moin! 29-Jan-19 08:54 AM Boing! 29-Jan-19 08:54 AM A satisfactory amount of sparks was generated while cutting this 29-Jan-19 08:54 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190129_074636-E5CEA.jpg 29-Jan-19 08:56 AM What are you going to do? 29-Jan-19 08:56 AM and will be generated welding it back together? 29-Jan-19 08:57 AM TIG god doesn't like your words @GigaSquirrel 29-Jan-19 08:57 AM Nah stages of the vibration isolation platform 29-Jan-19 08:58 AM @Nixie swings a 6013 stick like a magic wand 29-Jan-19 08:59 AM Also fabricating a tip holder and practing soldering to piezos 29-Jan-19 08:59 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190129_033658-A3B8E.jpg 29-Jan-19 08:59 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190129_055516-527F0.jpg 29-Jan-19 09:01 AM Woah! 29-Jan-19 09:01 AM @AdamMcCombs I have tons of piezos, especially big ones, would you need any? (doubt you have difficulty to get them, just offering) 29-Jan-19 09:05 AM I have a few larger ones but I'm keeping my scan head small to improve preformace at atomic resolution 29-Jan-19 09:05 AM ok! 29-Jan-19 09:07 AM It's about rigidity and resonate frequency 29-Jan-19 09:08 AM (yeah, yeah, I was just offering because I got them for free a few years ago, just that) 29-Jan-19 09:09 AM Are they the round type or something else? 29-Jan-19 09:13 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20190129_181306-A5172.jpg 29-Jan-19 09:13 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20190129_181337-BE7B7.jpg 29-Jan-19 09:13 AM yeah, just normal piezos, some huge, some smaller, different metal widths (from crystal to border) 29-Jan-19 09:15 AM What I'm really looking for is the fancy 300v tube piezos 29-Jan-19 09:16 AM Sorry, can't help there. 29-Jan-19 09:16 AM Yeah they are usually custom 29-Jan-19 11:25 AM @Nixie if my idea works I suppose that the laser could control the increasing of the temperature in the crucible according to the increasing in the dutty cycle, I guess could bring a better control than the resistences. 29-Jan-19 12:11 PM Awesome!! Can't wait to see your tests. Wich laser are you going to try? CO2 over graphite? 29-Jan-19 12:22 PM I want to use a solid state laser 29-Jan-19 12:22 PM Few watts, 4 W for example 29-Jan-19 02:30 PM Oh, are you heating a very small mass then? 29-Jan-19 02:57 PM hng I hope I can snag this auction 29-Jan-19 02:57 PM it'll be so beautiful if I can 29-Jan-19 02:57 PM I hope no-one here is bidding against me 29-Jan-19 03:00 PM @Conmega you going for that 6" cross, or you find a different chamber? 29-Jan-19 03:00 PM Speaking of crucibles, I'm pretty sure I am going with a solid graphite ~4" crucible for my Faraday cup/beam dump. 29-Jan-19 03:08 PM I already have an 8"/8"/6" T with 3x 2.75"s 29-Jan-19 03:08 PM I'm eyeing up some viewports 29-Jan-19 03:09 PM Nice! 29-Jan-19 03:10 PM I have like a 4"? or so viewport adapted to an 8" but I found an auction with some 8"ers 29-Jan-19 03:10 PM like holy moly 29-Jan-19 03:10 PM It ends soon, plz don't bid snipe me 29-Jan-19 03:11 PM Don't worry, I have no need for 8", and already got my 6" viewport 29-Jan-19 03:11 PM There are two in the auction, I really only care for one, as it is anyway, so I'll probably be happy to part with one, @AdamMcCombs gets first dibs 29-Jan-19 03:11 PM after that it'll be for sale probably here for basically what i payed for it 29-Jan-19 03:11 PM just to recoup some costs 29-Jan-19 03:11 PM It'll be wonderful to have that big of a viewport :) 29-Jan-19 03:13 PM Definitely lol, big viewports are a plus if you can accommodate them 29-Jan-19 03:13 PM What are you going to use your system for? 29-Jan-19 03:13 PM Yes this small laser is to heat very small mass 29-Jan-19 03:14 PM I'd like to experiment with plasma etching silicon 29-Jan-19 03:14 PM ussually RIE, but I think there are some other types 29-Jan-19 03:14 PM Avoiding super nasty gasses would be nice, but we will see :) 29-Jan-19 03:15 PM Sounds cool! Not my area so I don't know much about it, but looking forward to seeing how it goes! 29-Jan-19 03:15 PM Supposedly the way to neutralize most of the nasty gasses is just to pass the output of your pump through some plasma chambers and just burn the shit out of it 29-Jan-19 03:16 PM @rcartaya what type of solid state laser? 29-Jan-19 03:16 PM I'd be hesitant to run toxic gases, but that's just me lol 29-Jan-19 03:16 PM Ideally I will be running no gases 29-Jan-19 03:17 PM that's assuming I can even produce/aquire them lol 29-Jan-19 03:17 PM I'll need at-least something like N2 at a certain pressure for basic plasma etch 29-Jan-19 03:17 PM since it works by just accelerating particles towards your work piece and knocking bits off basically 29-Jan-19 03:17 PM as far as I know anyway 29-Jan-19 03:17 PM so I may not even need to run the turbo for it, but I can't remember what the ratios/pressures are 29-Jan-19 03:19 PM This is just DC plasma between parallel plates, no magnetron type enhancement? 29-Jan-19 03:20 PM I think that's one option? But RIE is generally high voltage RF, 13.56Mhz 29-Jan-19 03:20 PM Which I still need to get equipment to generate, or hack something together 29-Jan-19 03:25 PM I did a write up for more advanced simulation using TRIM to simulate sputtering of DC glow discharge plasma using the Davis and Vanderslice ion energy distribution for sputtering and damage yields for various gases. This was just for SS and DC glow discharge, but it can easily be modified for whatever target material and replacing the distribution function with one closer to RF plasma glow discharge. If you want to get really in depth into that area, TRIM is a huge asset, and possibly something you would be interested in exploring if you haven't already done so. Doesn't cover reactive etching specifically, but you can look at general target damage, implantation, and sputter yields for plasma ion bombardment of a substrate 29-Jan-19 03:26 PM I will have to look into that, I have never done any kind of simulation stuff so it'll be fun to learn, is the resource for this linked and pinned somewhere? :) 29-Jan-19 03:27 PM Yeah, it's free software, and I have the full write up page and modified input code generator for more advanced simulation 29-Jan-19 03:27 PM Hold on 29-Jan-19 03:28 PM https://giphy.com/gifs/x5kvlARMAkxri 29-Jan-19 03:28 PM http://www.srim.org/SRIM/SRIMLEGL.htm 29-Jan-19 03:28 PM Make sure you use SRIM 2013 29-Jan-19 03:28 PM General page: http://www.srim.org 29-Jan-19 03:28 PM Here is my write up page: http://appliedionsystems.com/portfolio/trim-simulation-of-sputtering-and-implantation-from-dc-glow-discharge-plasma-in-stainless-steel/ 29-Jan-19 03:29 PM Mind putting this in #resources? 29-Jan-19 03:30 PM Sure, no problem 29-Jan-19 03:30 PM I'm sure others will find use with this info :) 29-Jan-19 03:38 PM All posted 29-Jan-19 03:38 PM But it's a very powerful and standard simulator for exactly this area. Definitely recommend it for anyone getting into semiconductor manufacturing 29-Jan-19 03:43 PM \o/ Thanks! I'll have to play with it! 29-Jan-19 03:44 PM Np! It's actually pretty easy to use, has a full user interface and there is documentation and tutorials available as well 29-Jan-19 03:44 PM Welp that'll be run under my Windows 7 VM I guess 29-Jan-19 03:44 PM Running Linux is kinda a PITA when you come across obscure windows EXECs 29-Jan-19 03:44 PM does this require significant processing power today? or did it require it in 1997 and it doesn't matter anymore lol 29-Jan-19 03:44 PM I have two cores and like 4-8GB? Of ram to my win 7 VM 29-Jan-19 03:45 PM No lol, it doesn't really need much processing power at all 29-Jan-19 03:45 PM I have the VM for TI's Code Composer studio since its a PITA to get setup under Arch Linux... 29-Jan-19 03:45 PM cool 29-Jan-19 03:46 PM I just use windows, I don't know much about Linux. Even computers in general I'm horrible at 29-Jan-19 05:53 PM I started using a PC when I was like 18 months old... I just... computer... all the time :) 29-Jan-19 05:53 PM Woot! 29-Jan-19 05:53 PM https://www.ebay.com/itm/LOT-OF-MDC-VARIAN-VACUUM-VIEW-PORT-VIEWPORT-CONFLAT-8-034-OD-/153351794004?_trksid=p2047675.l2557&autorefresh=true&nma=true&si=HZYvcA9wZ9t5zS6TRXT7qw1xY3o%253D&orig_cvip=true&nordt=true&rt=nc 29-Jan-19 05:53 PM They are mine! 29-Jan-19 05:53 PM Kinda pricey for general HV purchase, but for those size of viewports... I'd call that cheap :) 29-Jan-19 06:30 PM Wow damn, major steal! That's super cheap for viewports that big! I think my 6" was more expensive 29-Jan-19 06:40 PM I hoped so :) 29-Jan-19 06:40 PM But yea I think I payed like 100 for the 4" viewport adapted to 8" awhile ago lol 29-Jan-19 06:40 PM Ah it was 4.5" Conflat viewport on a 4.5" to 8" adapter 29-Jan-19 06:40 PM I need more 8" Ts and stuff :) 29-Jan-19 06:53 PM Hrm... I really need a 6" CF to NW160 to attach my turbo... I was looking at this: https://www.ebay.com/itm/Conflat-EVAC-Adapter-Flange-6-inch-CF-to-NW160-NorCal-Products-unused/371847505106 But it doesn't appear to have clamping points on the top of the NW??? How do you clamp this? 29-Jan-19 06:53 PM ohh I should read the description... 29-Jan-19 06:53 PM its for a weird "quick connect" chain clamp? 30-Jan-19 01:48 AM yawn 30-Jan-19 01:48 AM Good morning! 30-Jan-19 03:57 AM morning! 30-Jan-19 03:57 AM \o/ 30-Jan-19 05:08 AM Moin 30-Jan-19 05:08 AM @Applied_Ion I am looking to order a 450 nm 4W laser by ebay 30-Jan-19 09:44 AM moin! 30-Jan-19 11:19 AM moin 30-Jan-19 07:36 PM yummy beer 30-Jan-19 10:59 PM Morning! \o/ 30-Jan-19 11:06 PM moin 30-Jan-19 11:32 PM Moin! 30-Jan-19 11:36 PM what's your fav cleaning process for fresh machined vac parts made of ss or alu? concatenation of rinsing baths etc 31-Jan-19 01:16 AM Water and soap rinse,+ KH7 rinse for ss, and a good rub with isopropyl alcohol. 31-Jan-19 01:16 AM Not sure it is a good method. 31-Jan-19 03:24 AM Acetone followed by isopropyl is a classic. I don't really like acetone that much because it is so volatile it's hard to be sure you even got it on there. Since I got an ultrasonic cleaner I've been using mainly that. The cleaner has plain water in it, and I put the parts in a zip bag with fresh degreaser solution. Then rinse with tap water. Can follow with distilled water spray. Wipe down with paper towel and blow out any holes with filtered compressed air. If it is going right in the chamber I heat it up with a heat gun to drive off water. 31-Jan-19 06:05 AM i want to use acetone and ipa with the US 31-Jan-19 06:05 AM ultra sonic cleaner 31-Jan-19 06:05 AM to gain the wettening 31-Jan-19 08:38 AM @AdamMcCombs I formally request that someday you make a chat about your latest atomic resolution scope 31-Jan-19 09:22 AM yeah 31-Jan-19 09:23 AM Like an ama or what? 31-Jan-19 09:23 AM yeah 31-Jan-19 09:24 AM https://dberard.com/home-built-stm/ 31-Jan-19 09:24 AM what are your best 1 atm down to uhv (10^-9 mbar) times? (small volumes are ok) 31-Jan-19 09:24 AM My scope is a build of Dan's, I did it back in high school but never got it to atomic resolution 31-Jan-19 09:24 AM So I decided to take a few days and see how far I could push the system 31-Jan-19 09:24 AM It also helps having support from an SEM this time around. It was my first microscope project and probably why I ended up getting my first SEM 31-Jan-19 09:24 AM Best time down to uhv hm 31-Jan-19 09:27 AM ever experienced pressure drop during methanol leakage ( > 10^-7 mbar) test? 31-Jan-19 09:27 AM Yeah 31-Jan-19 09:27 AM normaly you would have a rise but etf? 31-Jan-19 09:27 AM vvtf 31-Jan-19 09:28 AM It's not actually a pressure drop, just the different sized molecules interacting with the guage 31-Jan-19 09:28 AM more current? 31-Jan-19 09:29 AM What type of guage are you using? 31-Jan-19 09:29 AM penning 31-Jan-19 09:29 AM Yeah that tracks 31-Jan-19 09:29 AM in this case 31-Jan-19 09:29 AM i mean less current 31-Jan-19 09:29 AM When doing methonol testing you are looking for up or down 31-Jan-19 09:30 AM ok 31-Jan-19 09:30 AM thought only up 31-Jan-19 10:58 AM More than an ama, a show around, general explanation of the build. Easy parts, difficult parts. 31-Jan-19 10:58 AM You know, show the thing. 31-Jan-19 10:58 AM If you happen to be in the mood, I mean. 31-Jan-19 11:14 AM Yeah I think I'm going to do a big thread on everything once it's running 31-Jan-19 11:33 PM https://tenor.com/view/black-man-men-africa-uganda-gif-10858159 31-Jan-19 11:33 PM had to be done 31-Jan-19 11:33 PM also, Morning everyone! \o/ 01-Feb-19 12:51 AM Moin! 01-Feb-19 05:22 AM @N00N you don't really need the organic solvents with ultrasound, tho ppl do do that. It's a fire hazard for one, since things heat up. But also from what I hear it is unnecessary, from reading on websites for companies that do critical cleaning. FWIW, at the vacuum I have experience with ~3e-5 Torr I don't see any vacuum effects from other than water unless there is a big amount of non vacuum oil, like on an old stepper motor I tried. But coating adhesion and quality is pretty sensitive to the surface condition. Plasma cleaning is the final touch up, but you don't want any dirt to speak of on there when it goes on the chamber. 01-Feb-19 07:17 AM the lathe I've been looking at was lowered by ~25% 01-Feb-19 10:14 AM moin! 01-Feb-19 10:23 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190131_231004-E3411.jpg 01-Feb-19 10:30 AM Awesome! now, explain. 01-Feb-19 10:43 AM That's a bit involved. Next time I'm in the shop I will though 01-Feb-19 09:46 PM nice 01-Feb-19 09:55 PM @robamacl yeah, currently i'm using degreaser->acetone(with us)->IPA(with us) and then pre-baking. 01-Feb-19 09:55 PM degreasing with brushy 01-Feb-19 09:55 PM the brush 01-Feb-19 10:10 PM what i also wanna try is electropolishing for simplifying the surface finish process, any recommendations for electrolyte special sauces? 01-Feb-19 10:10 PM in theory it's like sulfuric acid, phosphoric acid, a dash of methanol plus bit of electric current, voila electro polishing - but i guess in practice it is not that simple, right? 01-Feb-19 10:52 PM Applied science has an electropolishing aluminum show. Problem for large items like chambers is that you need a big tank full of concentrated acid and there is a critical current density you have to operate at to get the effect, so a big power supply. And then fume disposal, acid disposal, etc. It seems that electropolishing is mainly for stainless. Aluminum gets a non electro "bright dip", also acid. 01-Feb-19 10:59 PM yep 02-Feb-19 01:18 AM moin! 02-Feb-19 11:07 PM Morning! 02-Feb-19 11:07 PM \o/ 03-Feb-19 12:12 AM moin 03-Feb-19 01:18 AM moin 03-Feb-19 10:34 AM https://share-ng.sandia.gov/news/resources/releases/2005/manuf-tech-robotics/mm-robot.html @GigaSquirrel 03-Feb-19 10:38 AM oh my 03-Feb-19 10:38 AM looks fun 03-Feb-19 10:38 AM I mean its better than other methods 03-Feb-19 10:38 AM cough 03-Feb-19 10:38 AM gets the angle grinder and a broom stick 03-Feb-19 10:39 AM dies 03-Feb-19 10:39 AM not an option 03-Feb-19 10:39 AM if you die, try again 03-Feb-19 10:40 AM contaminates everything 03-Feb-19 10:40 AM that's what the broom on the other side of the broomstick is for 03-Feb-19 10:41 AM Yeah because brooms are exactly what you want to use when trying to keep something from going airborne 03-Feb-19 10:42 AM :D 03-Feb-19 10:55 PM moin 03-Feb-19 11:17 PM morning 04-Feb-19 01:04 AM moin! 04-Feb-19 02:13 AM Borning! \o/ 04-Feb-19 02:26 AM Moin 04-Feb-19 02:26 AM Moin 04-Feb-19 02:26 AM I realize that @Applied_Ion is doing the CAD designs in autodesk, I have only experience in Solid Works, I would like to consult if you guys recommend to me to move to autodesk. 04-Feb-19 05:06 AM @rcartaya You mean Fusion 360? 04-Feb-19 05:06 AM Yesterday on the voicechat, we talked a bit about it. I came from a 2D software called DoubleCAD, and found Fusion extremely intuitive in many things (for mechanical pieces). @sync explained that for extremely complex things or profesional ones, he uses a different software (can't remember wich one, sorry). 04-Feb-19 05:39 AM @rcartaya I use fusion360. Both for hobby work and professional. I've tried a couple different programs (NX, Solidworks), and for me, I like fusion 360 the best by a long shot. For what I do, I enjoy using it tremendously and find it incredibly powerful. Not to mention it's free to use as well! But I definitely recommend it for sure. Definitely the most intuitive program for cad in my opinion. 04-Feb-19 06:19 AM @Nixie Yes I mean fusion360, thank you very much, you are right. @Applied_Ion thank you very much for your recommendation, I will install 360 tonight to start with my next project. 04-Feb-19 07:02 AM I can recommend also Lars Christensen youtube channel for the basics, it won't take much time to watch the 3 parts. https://www.youtube.com/watch?v=A5bc9c3S12g 04-Feb-19 07:02 AM And btw, I use a space navigator mouse with it. It is not necessary at all but, for me, when I began, I found the trinket helped me start and play with the program. They can be found cheap-ish on ebay at around 60€ 04-Feb-19 07:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/9k-248BB.png 04-Feb-19 07:02 AM (and now I can't work without it. It helps me move the pieces around, wich I do much) 04-Feb-19 07:02 AM (I have broken arm-induced ambidexterity, wich also helps, mouse on the right hand, 3D mouse on the left hand. ( write with my LEFT hand, so this is a very weird situation/setup) 04-Feb-19 07:50 AM it's not professional use that I meant, it's just that using fusion to CAM free form parts is really annoying 04-Feb-19 07:50 AM as they cannot do constant scallop height machining 04-Feb-19 08:41 AM Ah, I meant it with respect! ^^ 04-Feb-19 10:35 AM Solidworks has a free license for hobbyist/noncommercial use now. I've used virtually every major CAD program professionally (MechE) and to me, Solidworks is still the gold standard. 04-Feb-19 10:41 AM I should try solidworks, just to test. Any youtube tutorials on how to get started? 04-Feb-19 10:42 AM solidworks also seems to have a free maker license thesedays 04-Feb-19 10:42 AM But it's far more ristrictive than the fusion360 "free as long as you make less than 100k a year" 04-Feb-19 10:43 AM Solidworks is nice 04-Feb-19 10:43 AM how much more restrictive? 04-Feb-19 10:58 AM https://www.solidworks.com/sw/education/SDL_form.html 04-Feb-19 10:58 AM The code I found is 918MAKER 04-Feb-19 11:05 AM tree fell on my house :/ 04-Feb-19 11:05 AM luckily doesnt seem to have broken anything, the wind will stop in 5hrs 04-Feb-19 11:05 AM doesnt seem to be going anywhere 04-Feb-19 11:05 AM tree service coming tomorrow at 9am to take a look 04-Feb-19 11:05 AM https://imgur.com/a/cjlPuZe 04-Feb-19 11:05 AM oof 04-Feb-19 11:05 AM lol 04-Feb-19 11:05 AM it happened when I was out hiking with the dog in the woods 04-Feb-19 11:05 AM with the snow 04-Feb-19 11:05 AM meh 04-Feb-19 11:05 AM nothign broken, but that window it is near, I have a replacement for downstairs as I am renovating the house 04-Feb-19 11:05 AM so, uniquely prepared 04-Feb-19 11:05 AM anywho, school was obviously cancelled today 04-Feb-19 11:05 AM time to watchTV all day 04-Feb-19 11:08 AM Enjoy! 04-Feb-19 11:11 AM Was doing some soldering last night and the felt tip on my flux pen came off and dumped like 10mL of flux on my pants. 04-Feb-19 11:11 AM oof 04-Feb-19 11:11 AM Thats not fun 04-Feb-19 11:11 AM Wash machine probably smells funny now as well 04-Feb-19 11:12 AM my mother had burn holes on all of her pants from hot solder falling off and landing on her thighs 04-Feb-19 11:12 AM k, back to TV 04-Feb-19 11:20 AM Bahahaha 04-Feb-19 12:10 PM Thaks a lot for the advises about CAM/CAD softwares. I will restart with solidworks while I train a little in 360 04-Feb-19 03:14 PM @Nixie More restrictive as in no commercial use, or our lawyers will bill you. and yeah that 918MAKER worked for me a week or so ago. 04-Feb-19 10:23 PM Will have to try it and see which one works best for me. Altough fusion will eat a chunk of the market for sure. 04-Feb-19 10:33 PM Also: Morning! \o/ 04-Feb-19 10:33 PM Evening! 04-Feb-19 11:51 PM moin! 05-Feb-19 12:06 AM Moinsen 05-Feb-19 12:26 AM moin! 05-Feb-19 12:36 AM woohoo, the hornets are already in germany! 05-Feb-19 12:46 AM moin 05-Feb-19 01:10 AM Moin 05-Feb-19 01:55 AM That was fast! 05-Feb-19 02:27 AM Yep! 05-Feb-19 03:50 AM moin 05-Feb-19 03:50 AM hmm, I don't like the hornets that much 05-Feb-19 03:51 AM how come? 05-Feb-19 03:51 AM yep, they are 05-Feb-19 03:51 AM don't know if they work better with the original controller 05-Feb-19 03:51 AM but they're cheap 05-Feb-19 03:52 AM sometimes they work, sometimes you have to power cycle them five times, an sometimes they create enough EMI to reset my lab bench power supply 05-Feb-19 03:52 AM Oo 05-Feb-19 03:52 AM never had that issue 05-Feb-19 03:53 AM is seems to be some contact issue with the spring-loaded ground connection to the aluminium case 05-Feb-19 03:53 AM if that happens I have to open them, scratch the surface under the scew a bit, and then it works again for few days 05-Feb-19 03:54 AM that's a fair point, I've wondered if that really connects reliably 05-Feb-19 03:55 AM plus the range is a bit too low imho, 10^-2mbar or something even higher would be way more convinient 05-Feb-19 03:56 AM that's the range for piranis / baratrons etc 05-Feb-19 03:56 AM for a sealed system with a working oump setup it is fine, but when oftenly swapping receipients I noticed that small leaks are enough to not reach the measurement range, and then you have to debug everything 05-Feb-19 03:57 AM well, if you don't even get below e-3 I don't see what you'd need a ionisation gauge for 05-Feb-19 03:57 AM I'm really happy to now have that balzer full range gauge I got with the pumping setup and the other stuff, that thing is great 05-Feb-19 03:57 AM those combination pirani / penning things? 05-Feb-19 03:58 AM I do get below 10^-3, given my setup is properly sealed 05-Feb-19 03:58 AM but espacially for finding those leaks a gauge is particulary helpful, but only if it works in that range 05-Feb-19 03:59 AM I you don't go that low the hornet's just not the right gauge for you 05-Feb-19 03:59 AM it's like connecting a ion getter pump to a system working at e-3 and complaining that you don't get those crazy high pumping rates 05-Feb-19 04:00 AM actually I never had the problem with micro leaks, either I forgot grease at a flange or there was dirt on an O-ring and I ended up at only 10^⁻2mbar which I usually noticed by my turbo not reaching max speed within a minute, or the setup was sealed and I quickly reach <10^-5mbar which is good enough for everything I do 05-Feb-19 04:00 AM so yeah, the hornets are good for my application, given that I reach their range 05-Feb-19 04:00 AM which I usually don't do in case of a leak, in which situation a gauge would be espacially useful to locate the problem 05-Feb-19 04:03 AM yes, a gauge is great for finding leaks, but different gauges work in different ranges, from atmosphere to ~e-3 you want a pirani and not an ionisation gauge 05-Feb-19 04:03 AM with the pirany / penning combo I can now jiggle connections and apply manual pressure to flanges and quickly locate the location of the leak, speeding up debugging from reopening every connection to just cleaning the one that seems to cause the problem 05-Feb-19 04:03 AM yeah I knew that, just stating that out for everyone else who might haven't realized that yet 05-Feb-19 04:03 AM eg. for @Nixie with his turbo, he has to get everything working before he can even use the hornet 05-Feb-19 04:09 AM I still don't get your point 05-Feb-19 04:09 AM are you complaining that the gauges don't work outside of their specified range? 05-Feb-19 04:28 AM no 05-Feb-19 04:28 AM I'm just saying that you should keep in mind that these gauges are basically useless if you're just getting started with high vacuum stuff 05-Feb-19 04:28 AM because once you can use those, you already did reach pretty good vacuum 05-Feb-19 04:28 AM and, unrelated to that, I'm complaining that the hornet gauges are unreliable and should be considered as "better than nothing" if you really, really can't afford anything better 05-Feb-19 04:37 AM well, maybe one should learn about the basics of measuring vacuum before attempting to build a high vacuum setup 05-Feb-19 04:37 AM because it might be interesting to know your pressure before you turn on your high vac pump 05-Feb-19 05:44 AM criticizing the hornets is blasphemy! 05-Feb-19 05:44 AM go, get his yellow badge! 05-Feb-19 05:44 AM :D 05-Feb-19 05:45 AM 05-Feb-19 05:45 AM His point does have merit, though. 05-Feb-19 05:45 AM For the price, it's better than nothing for sure. 05-Feb-19 05:47 AM you are not allowed to criticize them for that price 05-Feb-19 05:47 AM yeah, grounding is fixable 05-Feb-19 05:47 AM and if you need higher pressure gauge, dont buy a hot ionisation gauge 05-Feb-19 05:52 AM The shame is that I only have either a micron gauge or the hornet. 05-Feb-19 05:52 AM nothing in between. 05-Feb-19 06:23 AM but that's not the fault of the hornet 05-Feb-19 06:36 AM True. 05-Feb-19 06:47 AM but isn't 1 micron ~1e-3 mbar? 05-Feb-19 06:47 AM so if your gauge measures down to single digit microns it bottoms out right where the hornet starts 05-Feb-19 06:52 AM Oh...I might have mixed units at some point. 05-Feb-19 06:52 AM Nice! 05-Feb-19 06:59 AM You're welcome 05-Feb-19 07:48 AM school cancelled again today, was a late start but they just updated to all day 05-Feb-19 07:49 AM so much free time! 05-Feb-19 07:49 AM how's your house doing? 05-Feb-19 07:50 AM no apparent damage, the tree guy cming in one hour to take a look and give me a quote on removal 05-Feb-19 07:50 AM was like a 20 meter limb or there abouts 05-Feb-19 07:50 AM half is diagonally slanted, the top half is ontop the roof itself 05-Feb-19 07:50 AM it's actually like 3 branches 05-Feb-19 07:50 AM and, I think the ivy that was aorund the tree helped slow it downn 05-Feb-19 07:51 AM Good! 05-Feb-19 07:51 AM he cuts the tree and you keep the wood or does he also keep the wood? 05-Feb-19 07:52 AM they typically discard the wood, but it is in a ECA.. environmentally critical area... a creek seperates me from the next guy, and because of this, they may have to leave it on the ground 05-Feb-19 07:52 AM ie, no disturbing the area 05-Feb-19 07:52 AM of course you are allowed to remove a tree from your roof.. but the actual removal of stuff is sometimes not allowed 05-Feb-19 07:52 AM it's strange 05-Feb-19 07:52 AM anywho this same tree service company has done work on that property - which isnt mine.. which makes everything 10x worse/harder 05-Feb-19 07:58 AM Well, nature needs to be preserved. 05-Feb-19 07:58 AM but, they got permission before 05-Feb-19 07:58 AM right 05-Feb-19 07:58 AM it's just a hassle 05-Feb-19 07:59 AM At least school was cancelled. 05-Feb-19 07:59 AM XDDD 05-Feb-19 07:59 AM ikr? 05-Feb-19 07:59 AM dog is feeling a bit better, too 05-Feb-19 08:03 AM safety comes first, so removing dangerous trees is always ok 05-Feb-19 08:04 AM "removing" and cutting it down and leaving it on the ground are two slightly diffeerent things 05-Feb-19 08:04 AM no 05-Feb-19 08:05 AM in a nature perspective 05-Feb-19 08:05 AM in both cases you cut it down and remove the hazard 05-Feb-19 08:05 AM err, the hazard is removed 05-Feb-19 08:05 AM but in certain situations you are not allowed to physically remove what you cut down 05-Feb-19 09:46 AM expensive estimate, relative to free 05-Feb-19 09:46 AM but.. tree on house, get tree off of house 05-Feb-19 09:46 AM pay the man 05-Feb-19 09:46 AM XD 05-Feb-19 09:50 AM does anyone have a better contact to vacuubrand than info@vacuubrand.com? 05-Feb-19 09:51 AM For what? Support? Sales? 05-Feb-19 09:51 AM https://www.vacuubrand.com/en/page536.html 05-Feb-19 09:52 AM I need some replacement parts, my pump broke yesterday 05-Feb-19 09:53 AM oh! 05-Feb-19 09:53 AM servicevacuubrand.com 05-Feb-19 09:53 AM bad luck 05-Feb-19 09:53 AM I already found all information I need and requested a quote, but I thought it might be possible someone here knows a service technician or anything and can get me the parts 05-Feb-19 09:53 AM service@vacuubrand.com 05-Feb-19 09:53 AM oh no nevermind... 05-Feb-19 09:54 AM https://www.vacuubrand.com/context/other_documents/20999231.pdf 05-Feb-19 09:54 AM this is (i think) what I need 05-Feb-19 09:54 AM http://www.myneolab.de/83/1/AD193/MjA2NDk5ODc=/193%2020649987%20neoLab.html 05-Feb-19 09:54 AM hmm, nervermind 05-Feb-19 09:54 AM I can get a new pump for that price... 05-Feb-19 10:00 AM ^^U 05-Feb-19 10:13 AM @niklas interesting point that occurrence rate of leaks decreases with decreasing size. This is something that surprised me when I read it on a professional vacuum co. blog, but is consistent with my experience. Big leaks common, smaller leaks less so. I would have expected the reverse, fractal leaks. 05-Feb-19 10:13 AM Perhaps this changes in UHV? But it seems that you may switch more to other gas loads, outgassing and permeation, rather than a point leak. 05-Feb-19 10:17 AM It really depends on why type of system it is, metal vs Viton seals, how old it is, and what vacuum it need to get to 05-Feb-19 10:28 AM IIRC this was on the Vacaero site. https://vacaero.com/ they make industrial vacuum furnaces, large, diffusion pump, elastomer seals. But I think the writer was talking about larger experience in systems where small leaks would matter. 05-Feb-19 02:59 PM tree off of roof 05-Feb-19 03:03 PM Yeah! 05-Feb-19 03:03 PM roof still on house? 05-Feb-19 04:41 PM yup, minimal damage.. this summer I am putting a new roof on, anyways 05-Feb-19 04:41 PM but, unplanned expenses 05-Feb-19 04:41 PM especially as I was looking at lathes 05-Feb-19 06:58 PM I got my 8" conflat viewports and 4.5" viewport in the mail today they are perfecttt <3 05-Feb-19 11:36 PM 05-Feb-19 11:45 PM moin 05-Feb-19 11:52 PM I just found a perfect word wich was not "moin", nor "boing"...but it contained the letter g, and might be a bit too much. XDDDDDD Morning, then! \o/ 06-Feb-19 12:05 AM loin! 06-Feb-19 12:23 AM Going! 06-Feb-19 01:41 AM Dobro Jutro! 06-Feb-19 02:01 AM Bon día! (catalan) 06-Feb-19 06:21 AM chirp chirp 06-Feb-19 06:28 AM stomps the insect while screaming like a girl 06-Feb-19 06:29 AM nooo 06-Feb-19 06:32 AM https://tenor.com/view/jonah-hill-yay-greek-aldos-gif-7212866 06-Feb-19 06:59 AM mystery part time 06-Feb-19 06:59 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_4234-7D912.JPG 06-Feb-19 06:59 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_4235-BDFA9.JPG 06-Feb-19 06:59 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_4236-D34E3.JPG 06-Feb-19 06:59 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_4237-3892E.JPG 06-Feb-19 06:59 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_4238-0DF52.JPG 06-Feb-19 06:59 AM https://i.ebayimg.com/images/g/MzQAAOSwxHlcWtdr/s-l1600.jpg 06-Feb-19 07:01 AM sputtering rig? 06-Feb-19 07:01 AM whatever is on top seems to be water cooled 06-Feb-19 07:01 AM the guy I got the viewports from is asking if I want to buy it 06-Feb-19 07:01 AM XDDD 06-Feb-19 07:01 AM Is it mostly free? 06-Feb-19 07:01 AM (super chea) 06-Feb-19 07:02 AM on one hand, its clearly conflat 6" on both ends, on the other, I have no idea what that thing on the end is and the only thing it adds to a conflat 6" setup is the viewport which seems custom, not standard conflat. 06-Feb-19 07:02 AM doesn't seem worth the hassle. 06-Feb-19 07:02 AM uhhm, well this is the guy I got the two 8" viewports and a 4.5" viewport for 177 bucks 06-Feb-19 07:02 AM so it might be "cheap" but not nothing :P 06-Feb-19 07:02 AM it looks like it might be an RF head though... 06-Feb-19 07:02 AM for etching or something 06-Feb-19 07:02 AM in which case I am interested 06-Feb-19 07:03 AM @AdamMcCombs or @Applied_Ion might know more. 06-Feb-19 07:03 AM whoever made it made the parts as unassuming as possible 06-Feb-19 07:03 AM yup 06-Feb-19 07:03 AM actually... 06-Feb-19 07:03 AM .... 06-Feb-19 07:03 AM ... 06-Feb-19 07:03 AM is that just a light bulb inside? 06-Feb-19 07:03 AM like a halogen bulb? 06-Feb-19 07:03 AM it kinda almost has that glassy texture to it 06-Feb-19 07:03 AM it might literally just be a light into a chamber... which seems silly to me but 06-Feb-19 07:04 AM that looks like a sputtering pattern to me. 06-Feb-19 07:11 AM I suppose I could see how its a sputtering head... hrm 06-Feb-19 07:11 AM suppose I just didn't realize they did smaller heads like that in conflat, but I suppose there are tons of weird use cases for this stuff lol 06-Feb-19 07:13 AM I know sh|t, better ask around some more. ^^U 06-Feb-19 07:13 AM (but I will do put the medal if it was what I said. XDDDD) 06-Feb-19 07:15 AM if it is a sputtering you definitely get a metal though I think adam may have suggested that when I DMed him last night with no photos on the inside :P 06-Feb-19 07:15 AM So you'll have to fight for it 06-Feb-19 07:15 AM but I think I'll get it if its a sputtering head... could use a sputtering head 06-Feb-19 07:15 AM if its of any quality like the viewports I got from the guy... the knife edges should be perfect 06-Feb-19 07:18 AM Not sure, difficult to say st this point. With the cooling lines and connector like that it could be some sort of sputtering head. Size isn't an issue - you can get 1" sputtering heads in conflat hardware, so definitely not too small to be one 06-Feb-19 07:18 AM I'm going with water cooled evap / sputter rig 06-Feb-19 07:18 AM cool 06-Feb-19 07:18 AM yea I was looking for that similar color... most of the sputtering heads you see are copper? 06-Feb-19 07:18 AM https://static1.squarespace.com/static/527ba911e4b088797b06ebdb/t/530e12c6e4b0362463e5e999/1393431270418/Sputtering-Target_Specialty-Metals-Smelters-and-Refiners.gif?format=300w 06-Feb-19 07:18 AM *cooled 06-Feb-19 07:19 AM but that looks very similarly colored for the target 06-Feb-19 07:19 AM depends on what you want to sputter? 06-Feb-19 07:19 AM sure, I was mostly curious as to what the target that was on there was if it was a sputtering head 06-Feb-19 07:19 AM its gotta be silver or some other odd material, the copper targets are pretty obvious :) 06-Feb-19 07:19 AM ahhh 06-Feb-19 07:19 AM Aluminum maybe 06-Feb-19 07:19 AM http://periodictable.com/Samples/013.52/s12s.JPG 06-Feb-19 07:19 AM Looks like an 1.5" 2"? head or something like that, so smaller... hrm I'll have to get some more conflat for my chamber :P 06-Feb-19 07:19 AM or have this be off on its own thing 06-Feb-19 07:19 AM Worst case its a conflat 6" to 6" with a little viewport I guess 06-Feb-19 07:19 AM I'll ask him what he was thinking of getting for it 06-Feb-19 07:19 AM its good to have too much conflat for trading fodder too I guess ¯\_(ツ)_/¯ 06-Feb-19 07:33 AM thats uh... 06-Feb-19 07:33 AM interesting... 06-Feb-19 07:33 AM first time I've seen a MICROWAVE integrated into a product... 06-Feb-19 07:33 AM https://www.ebay.com/itm/PLASMA-PREEN-with-gas-control-panel-etching-sputtering-cleaning-semi-conductor/303032830440?hash=item468e2a09e8:g:brUAAOSwN5hcQKe2 06-Feb-19 07:36 AM That's definitely interesting lol, though way overpriced. I've talked to a few people who converted normal microwave ovens into plasma cleaners for microfluidics work, but haven't seen a commercial microwave unit sold as a plasma cleaner before. 06-Feb-19 07:36 AM lol 06-Feb-19 07:45 AM ah yes, make an offer 06-Feb-19 08:54 AM wait and see if I can get Adam's opinion before making an offer on that thing 06-Feb-19 08:54 AM because I have a feeling its going to be like... 100+shipping, which isn't unreasonable if its what we think it is, but may be unreasonable if its just useful as a 6" T? 06-Feb-19 08:58 AM If it ends up being useless for you and you decide not to buy it, I may be interested in it for the tee part, since that is exactly what I need for my TOF beamline 06-Feb-19 11:18 AM I mean, I'd be mostly interested in the head piece if it is for sputtering, I don't necessarily need the T unless its integrated some how, which it doesn't appear to be 06-Feb-19 11:18 AM so maybe we can split it? 06-Feb-19 11:18 AM you get your T I get whatever the hell that head unit is lol 06-Feb-19 11:19 AM Yeah im not really sure about that sputtering head 06-Feb-19 11:19 AM If you have a use for it 06-Feb-19 11:19 AM I think that could work, as long as the seller asking price isn't crazy lol 06-Feb-19 11:19 AM he's asking for an offer 06-Feb-19 11:19 AM But otherwise /shrug 06-Feb-19 11:19 AM so its whatever won't offend him I guess 06-Feb-19 11:19 AM Im not sure if its good for SEM 06-Feb-19 11:19 AM What's the listed price? 06-Feb-19 11:19 AM well I need a sputtering device... 06-Feb-19 11:19 AM and having something off a chamber that I can control the gas environment better is probably better for silicon stuff than just those little sputtering units you can get 06-Feb-19 11:20 AM Silver will work for SEM but you want gold or gold palladium 06-Feb-19 11:21 AM oh right, that's what you mean 06-Feb-19 11:21 AM I wasn't even thinking of a sputtering device for my SEM... since I mostly want to look at dies and such under the scope which... is well hopefully not really going to need much sputtering... 06-Feb-19 11:21 AM just surfacing and such 06-Feb-19 11:21 AM but I mean I can replace the target in a sputtering head like that right? if it is one 06-Feb-19 11:21 AM @Applied_Ion he doesn't have it listed, he DMed me about it after I bought the viewports 06-Feb-19 11:21 AM so its wild west, what do you want to offer, the viewports started at like 50 bucks starting bid or something I got for 177... so I was thinking offering like 75 plus any shipping costs or something to start? 06-Feb-19 11:21 AM since this is just an odd piece of conflat to him I'm sure 06-Feb-19 11:23 AM If it's sputtering head it has to be replaceable, I can't imagine a one time use head, unless it's for some really crazy 06-Feb-19 11:23 AM Yeah but the cost to put the gold in... 06-Feb-19 11:23 AM Just to be sure, is it a 6" conflat tee with a 2.75" conflat port? 06-Feb-19 11:24 AM I.... don't think the viewport is standard conflat 06-Feb-19 11:24 AM its a viewport, but I am not sure if its any standard 06-Feb-19 11:24 AM the bolt pattern looks... too spread out? 06-Feb-19 11:24 AM at-least to my untrained eye 06-Feb-19 11:24 AM Yeah that's what I was wondering 06-Feb-19 11:24 AM That looks right for 2.75 06-Feb-19 11:24 AM oh ok 06-Feb-19 11:24 AM I mean did you plan on removing the viewport or just using it inline with stuff? 06-Feb-19 11:24 AM Yeah 275 is only 6 bolts 06-Feb-19 11:25 AM right, but it looks too... spread apart 06-Feb-19 11:25 AM I don't need the viewport. I agree it looks a bit oddly spread out as well 06-Feb-19 11:25 AM https://media.discordapp.net/attachments/513115950501855261/542721102867070987/IMG_4234.JPG https://www.accuglassproducts.com/sites/default/files/styles/medium/public/112659_001_10.jpg?itok=BOXTnhFH 06-Feb-19 11:25 AM ehhh I guess it looks about right 06-Feb-19 11:26 AM Maybe it's just the angle them lol 06-Feb-19 11:26 AM yea 06-Feb-19 11:26 AM I mean I can offer 75 I'll measure it before we make a deal, if its completely custom weird shit then you don't need to buy it from me lol 06-Feb-19 11:26 AM And hey as long as something is bolted to it its probably in good shape 06-Feb-19 11:26 AM yup 06-Feb-19 11:28 AM I think that works. If we make a deal, I will also cover half of the shipping charge as well. If it is 2.75" standard, that would be absolutely perfect 06-Feb-19 11:28 AM well I sent an offer lets make the gamble lol 06-Feb-19 11:28 AM alright cool I'll let you know 06-Feb-19 11:29 AM Thanks! It is a tremendous help, you have no idea lol 06-Feb-19 11:29 AM do you want the 2.75" viewport with it or do you want me to remove it? lol 06-Feb-19 11:29 AM if it is 2.75" 06-Feb-19 11:29 AM because if you don't need it I'll definitely use it or find it a home 06-Feb-19 11:30 AM Yeah, you can take it. I don't really need it for my setup 06-Feb-19 11:30 AM cool alright 06-Feb-19 11:30 AM man if I could get my hands on like an 8" conflat 4 way or something... I could have an awesome chamber lol 06-Feb-19 11:36 AM That would be a huge chamber lol. The adapters and blanks for that would certainly add up 06-Feb-19 11:39 AM 8"... what is that in real units? 06-Feb-19 11:39 AM about 20cm? 06-Feb-19 11:39 AM yeah 06-Feb-19 11:39 AM giggle 06-Feb-19 11:39 AM *approximate 06-Feb-19 11:40 AM i'm sorry, i'm not fluent in medieval measurement units. always have to google or use my reference books ... 06-Feb-19 11:42 AM @Applied_Ion I already have like... 2x 8" blanks and 2x 8" viewports :P 06-Feb-19 11:42 AM and an 8" - 8" - 6" T 06-Feb-19 11:42 AM oh and an 8" valve 06-Feb-19 11:42 AM problem is the T is all of like... 12" of 8" chamber 06-Feb-19 11:42 AM not very much 06-Feb-19 11:42 AM sorry if I'm flinging too many freedom units :P 06-Feb-19 11:43 AM Still plenty of good hardware to put something decent sized together! 06-Feb-19 11:44 AM yea, I just really need like one more 8" tee or something.. though I had a terrible terrible idea for a tiny silicon process line... 06-Feb-19 11:44 AM if I can get enough 8" pieces and valves... have a little track inside for a carier to ride along with different chambers for different processes 06-Feb-19 11:45 AM That would be awesome and quite an impressive setup 06-Feb-19 11:45 AM yea, unlikely I'll find another like 80 dollar 8" valve any time soon, so thats like pipe dream... lol 06-Feb-19 11:45 AM only that in reality it doesn't work like that 06-Feb-19 11:45 AM our prep chamber was like that and the stage always gets stuck 06-Feb-19 11:45 AM ball bearings and vacuum don't mix well 06-Feb-19 11:46 AM Got that right 06-Feb-19 11:46 AM There are good vacuum slide surfaces though 06-Feb-19 11:47 AM or you get DLC coated bearings 06-Feb-19 11:47 AM those work fine 06-Feb-19 11:47 AM i have a few linear bearing modules for vacuum applications. fancy stuff with ceramic ball bearings in a plastic carrier... sadly only 30mm or so of travel. 06-Feb-19 11:47 AM I can get into details but one of the fabs I work with built a 8ft chamber with a 3+2 stage in it that could move something like 2 tons 06-Feb-19 11:48 AM jesus 06-Feb-19 11:48 AM yeah it is not impossible 06-Feb-19 11:49 AM With high acceleration and jerk. It was insane 06-Feb-19 11:50 AM @AdamMcCombs ouch. the kind of machine that makes the whole building move... 06-Feb-19 11:50 AM Yeah 06-Feb-19 11:50 AM I wont even get into the shielding 06-Feb-19 11:52 AM somebody did not design the foundation correctly then 06-Feb-19 11:52 AM but yeah, one of our MBEs has a wafer robot in it, but it mostly crashes the wafers into the chamber wall 06-Feb-19 11:52 AM I never saw it in its home, just when it was being built 06-Feb-19 11:55 AM LOL thats uh... bad... 06-Feb-19 11:55 AM is it because of improper setup for the bot or just those bearing/vacuum issues you were mentioning? 06-Feb-19 12:23 PM no, the issue is the control 06-Feb-19 12:27 PM ah figures 06-Feb-19 12:30 PM Quick question 06-Feb-19 12:30 PM quick answer 06-Feb-19 12:30 PM :) 06-Feb-19 12:31 PM For diffpumps, do you turn off the heating and wait for it to cool down before turning off cooling or switch it both off at once? 06-Feb-19 12:31 PM Depends on the pump 06-Feb-19 12:31 PM On the EMs there's normally enough thermal mass that you can do that, not that its recommended 06-Feb-19 12:32 PM EM? 06-Feb-19 12:32 PM Electron Microscope 06-Feb-19 12:32 PM ...what else was I expecting from you 06-Feb-19 12:32 PM thermal mass might be an issue for mine, since it is air cooled 06-Feb-19 12:33 PM Yeah leave cooling on 06-Feb-19 12:33 PM ok ^^ 06-Feb-19 12:33 PM thanks! 06-Feb-19 01:31 PM this guy is weird, but yea he said Ok to 75 plus shipping costs 06-Feb-19 01:31 PM so yea probably like 100 bucks all in all for this thing 06-Feb-19 01:31 PM whatever this thing is lol 06-Feb-19 01:31 PM Awesome! 06-Feb-19 01:32 PM actually I just realized this guy is like an hour from my place... maybe a little more 06-Feb-19 01:34 PM Does he sell vacuum stuff regularly? An hour in which direction? 06-Feb-19 01:35 PM south of me 06-Feb-19 01:35 PM this is his seller page 06-Feb-19 01:35 PM https://www.ebay.com/sch/surplus2012/m.html?_nkw=&_armrs=1&_ipg=&_from= 06-Feb-19 01:36 PM Oh lol, even farther from me 06-Feb-19 01:36 PM he seems to sell other HV stuff 06-Feb-19 01:36 PM just not too much of it 06-Feb-19 01:36 PM but I mean I got those viewports from him too 06-Feb-19 01:36 PM so it may be that he just hasn't posted stuff 06-Feb-19 01:36 PM I mentioned I'm not far and if he has more to sell it might be easier for me to pickup, otherwise let me know when he has the part posted so I can purchase 06-Feb-19 01:44 PM Nice, sounds like you got some great deals from this guy 06-Feb-19 03:07 PM Card rack pneumatics 06-Feb-19 03:07 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/1YGEOXjhpW5caKfXNKFV1ck649xHwLahrDFbf3adIS-C0E9A.png 06-Feb-19 04:30 PM lol neat 06-Feb-19 04:30 PM so uh... @AdamMcCombs familiar with dry ice blasters at all? 06-Feb-19 04:36 PM they are nice to remove undercoating from cars 06-Feb-19 04:40 PM heh this is a smaller unit, only 1.2LBS per minute... but yea... 06-Feb-19 04:40 PM something I could possibly acquire... 06-Feb-19 04:41 PM "only" 06-Feb-19 04:41 PM you need quite a lot of compressed air as well 06-Feb-19 04:41 PM 140psi max yes 06-Feb-19 04:41 PM 12-50CFM 06-Feb-19 04:41 PM its sad this one doesn't seem to say it supports straight ice too... 06-Feb-19 04:41 PM I saw some that could 06-Feb-19 04:41 PM which is a bit more economical and easier to get any time 06-Feb-19 04:41 PM also it seems to be rougher 06-Feb-19 04:43 PM you need micropellets with those, mostly 06-Feb-19 04:43 PM the ones that work with regular pellets have a mill and compression thing in them 06-Feb-19 05:23 PM uh... this takes a solid block of dry ice and grinds it up 06-Feb-19 05:23 PM Did you make an aquasition? 06-Feb-19 05:34 PM Uhm... well I know where one is... and it might be seeing a metal grinder as its next stop... 06-Feb-19 05:34 PM You are saving it yes? 06-Feb-19 05:34 PM though I'm not sure if it is... 06-Feb-19 05:34 PM its kinda like a gamble... one of the machines have had parts removed it looks like so... its probably all going to scrap 06-Feb-19 05:34 PM but I'm not sure. 06-Feb-19 05:34 PM the unit is from 2010... so its like uh wow this isn't old 06-Feb-19 08:18 PM I get my LDS order in tomorrow woot 06-Feb-19 08:39 PM Nice! I got the diff pump oil today. Cleaned out the pump, and doing final assembly now 06-Feb-19 11:01 PM Bloing! 06-Feb-19 11:01 PM @Conmega we will await your dissasembly of the thing 07-Feb-19 03:26 AM moin! 07-Feb-19 05:26 AM so, how's everyone doing today? 07-Feb-19 05:29 AM moinsen! 07-Feb-19 05:29 AM don't answer @GigaSquirrel for his own sake, he has to learn! 07-Feb-19 05:29 AM otherwise relativly good, thanks 07-Feb-19 05:30 AM damn you 07-Feb-19 05:30 AM I need a distraction 07-Feb-19 06:31 AM I finished all my current small projects (that I got parts for) and my brain knocked myself out at midday. 07-Feb-19 06:52 AM sounds relaxing 07-Feb-19 06:52 AM want 07-Feb-19 06:56 AM I want pieces, not fall to the bed and loose half the day. 07-Feb-19 07:47 AM dreams of being able to just fall into bed and sleep 07-Feb-19 07:47 AM ahh, new valve installed, three days of pumping later and I'm back to e-7 range 07-Feb-19 08:01 AM 5.37 +/- 0.795 * 10^-7 to be precise 07-Feb-19 08:05 AM continous pumping, even in the night? 07-Feb-19 08:06 AM no, only ~13h per day 07-Feb-19 08:18 AM @Nixie going to actually try to get away with no re-building the RV12 since the kit is like 150 bucks and Adam said rebuilding them is a realllll PAIN 07-Feb-19 08:18 AM Just going to use flushing fluid to hopefully clean it out 07-Feb-19 08:18 AM the Loadlock is a little module, not much to dissasemble and the docs on it have pinouts so its not a big deal 07-Feb-19 08:19 AM It's fun but a pain 07-Feb-19 08:19 AM And the thing is pretty damn bullet proof 07-Feb-19 08:25 AM yea the little green flap on the output?input? was in good shape if I recall, so hopefully the rest of the seals internally are too 07-Feb-19 08:25 AM I need to power and get serial to this MKS 901P-11040 loadlock I have so I can test the pump: https://www.mksinst.com/docs/UR/HPS901ds.pdf 07-Feb-19 08:26 AM Did you read the article I sent you? 07-Feb-19 08:26 AM hmm? you sent me an article? 07-Feb-19 08:26 AM The RV 25 year thing 07-Feb-19 08:26 AM oh yea I don't think I read it all 07-Feb-19 08:26 AM was there some story of someone running one straight for the last 25 years with no rebuild lol 07-Feb-19 08:26 AM You should. It's a deep dive into that pumps mechanism 07-Feb-19 08:26 AM No, it just been around for 25 years 07-Feb-19 08:26 AM https://vacaero.com/information-resources/vacuum-pump-technology-education-and-training/957-the-rv-vacuum-pump-is-21.html 07-Feb-19 08:26 AM Also talks about common ware items and stuff 07-Feb-19 08:28 AM right, I was just wondering if it had some story on its reliability, I just got a, we've been doing this design for 25 years meaning its great! from my glance lol 07-Feb-19 08:29 AM Oh no it gets super in depth like seal by seal design breakdown 07-Feb-19 08:29 AM Not even made by Edwards 07-Feb-19 08:29 AM Just some guy who likes vacuum pumps 07-Feb-19 08:31 AM I see 07-Feb-19 08:46 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-6FDA0.png 07-Feb-19 08:46 AM https://www.johnmorrisgroup.com/Content/Attachments/122205/901PStandardSetup-MAN.pdf https://www.mksinst.com/Docs/R/HPS901man-REVI.pdf 07-Feb-19 08:46 AM These 901Ps are well documented 07-Feb-19 08:46 AM and you can get them for like 40-50 bucks all day, probably much cheaper from time to time 07-Feb-19 08:46 AM it also has 3 setpoint relays which is nice for process contol 07-Feb-19 08:46 AM these are neat little gauges 07-Feb-19 09:00 AM (i meant a dissasembly of the sputtering thing, or whatever it is) 07-Feb-19 09:14 AM oh yea I actually just purchased that 07-Feb-19 09:14 AM 95 bucks shipped 07-Feb-19 09:14 AM Oh neat it looks like I CAN get a pressure reading from the RS232 line on this transducer instead of having to read the analog voltage. 07-Feb-19 09:14 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-2D307.png 07-Feb-19 09:14 AM I'll have to get an arduino programmed with a little OLED to talk to this and spew out the treasure reading so I can make it a nice little integrated thing. Probably even just run it off a 9V battery so I don't even need external power since the unit runs on 9-30VDC 07-Feb-19 09:14 AM Maybe I'll make little boards for these if this little gauge is useful and people are interested. 07-Feb-19 09:14 AM Oh actually it looks like MKS makes the datalogger software available for free and easily downloadable... https://www.mksinst.com/vtsw/ Along with firmware flashing tools. 07-Feb-19 09:14 AM Well that was easy 07-Feb-19 09:14 AM Might still be nice to have a display readout on it. But to test my pump tonight or tomorrow, freaking just use the software. I'll just have to hack up a VGA cable to make a serial cable woot 07-Feb-19 05:57 PM moin 07-Feb-19 08:19 PM https://www.ebay.com/itm/High-Vacuum-DN35-2-75-CF-Feedthrough-to-NW25-Flange/132876280626 Thats one way to do CF 2.75" to NW25 LOL 07-Feb-19 11:37 PM hehe 07-Feb-19 11:37 PM did the job i guess 08-Feb-19 01:34 AM hello general 08-Feb-19 01:35 AM Hello N00N 08-Feb-19 01:35 AM hii @GigaSquirrel 08-Feb-19 02:27 AM is there any way to balance a tmp? 08-Feb-19 02:27 AM I just read that my TMH 064 is supposed to be more quite, <50dBA, and its definetly more noisy than that 08-Feb-19 02:27 AM and I'm not sure if that's due to the potentially demaged bearing or unbalanced rotor 08-Feb-19 02:27 AM it has a lot of threads in the top to screw in one or multiple srcews to balance it 08-Feb-19 02:27 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Dy0u9VHU8AAlYfE.jpglarge-B99EF.jpeg 08-Feb-19 02:40 AM Bearings seem likely 08-Feb-19 02:44 AM Moin! 08-Feb-19 02:48 AM Moinsen! 08-Feb-19 03:10 AM @AdamMcCombs I don't know what even happened to the pump 08-Feb-19 03:10 AM when I received it, it didn't turn at all 08-Feb-19 03:10 AM when I took it apart to find the problem, this is what the bearings looked like: 08-Feb-19 03:10 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Dy4CJ3CWwAEefJc.jpglarge-DFC9A.jpeg 08-Feb-19 03:10 AM the bearing has crashed and all the balls came loose 08-Feb-19 03:10 AM I cleaned everything with ultrasonic because there was lots of metal dust suspended in the bearings oil 08-Feb-19 03:10 AM I was able to reasseble the bearing, and the ceramic balls appear to be undemaged 08-Feb-19 03:10 AM but maybe there is too much slackness in the metal parts now that cause the oscillation 08-Feb-19 10:09 AM Moist! 08-Feb-19 10:18 AM @niklas That sounds likely 08-Feb-19 10:42 AM So you reused the bearing that was crashed?? I would suspect that to be the issue if so... That will totally be out of tolerance now... New bearing shouldn't cost an arm and a leg... And if you got the pump for cheap/free I think its well worth the investment. 08-Feb-19 10:42 AM Especially if you've already tested it with the old bearing and it works 08-Feb-19 12:01 PM yes I reassembled the bearing and tested it 08-Feb-19 12:01 PM pump works fine but is pretty loud 08-Feb-19 12:01 PM The ceramic balls look fine, but I wthing the metal is out of tolerance 08-Feb-19 12:01 PM where can I get this very specific bearing? 08-Feb-19 12:05 PM Might be a standard size, just with fancy ceramics 08-Feb-19 12:05 PM Tho years ago a friend got a TMP with busted bearings and had trouble sourcing them. But he did not have this group to rely on. 08-Feb-19 12:05 PM Or more like he did not want a TMP so strongly that he would have paid for new ceramic bearings at that time. 08-Feb-19 12:44 PM well I've been looking for bearings already years ago for another leybold pump, and I had to accept that it is impossible to find a new bearing for that 08-Feb-19 12:44 PM so I'm very curious if that changed 08-Feb-19 12:49 PM oh.... wow... 08-Feb-19 12:49 PM that sucks 08-Feb-19 12:54 PM Part Number: B064RK Model: TMH/U 064/065 Description: Repair Kit Price: $785.00 08-Feb-19 12:54 PM yeah... 08-Feb-19 12:55 PM fdsaf 08-Feb-19 12:55 PM wow 08-Feb-19 12:55 PM that sucks 08-Feb-19 12:55 PM Well its either run with the old bearing hoping shit doesn't hit the fan and destroy a pump or buy a new bearing... 08-Feb-19 12:55 PM OR keep an eye out for another used turbo for that price XD 08-Feb-19 12:56 PM at least it doesn't sound like that pump 08-Feb-19 12:56 PM https://www.youtube.com/watch?v=a9WT8MuMGpw 08-Feb-19 12:56 PM I guess for my aplication the bearing is still fine 08-Feb-19 12:56 PM jesus 08-Feb-19 12:56 PM also turning a turbo on in open atomsphere... heh... I guess if you don't let it spin all the way up its fine but yea 08-Feb-19 12:58 PM yup it's fine 08-Feb-19 01:04 PM Just got a call for a scope that ran for 3 hours with no cooling and the safety circuit didn't engage. So 3 hours with no diffusion pump cooling, no optics cooling, and no power supply cooling. I can't even. 08-Feb-19 01:04 PM No water baffels, and 15 amps of linear supply would have overheated 08-Feb-19 01:07 PM Woooooooow 08-Feb-19 01:07 PM That is going to be sooooooo dead 08-Feb-19 01:11 PM :/ 08-Feb-19 01:11 PM It's not going to be good 08-Feb-19 01:11 PM Back streamed oil 08-Feb-19 01:11 PM It's blowing fuses 08-Feb-19 01:11 PM The key doesn't even work 08-Feb-19 01:11 PM The e stop doesn't work 08-Feb-19 01:12 PM I thought scopes had multiple safety sensors 08-Feb-19 01:13 PM Yeah so did i 08-Feb-19 01:13 PM 08-Feb-19 01:13 PM Some one apparently bypassed them all 08-Feb-19 01:13 PM HS! 08-Feb-19 01:13 PM :XXX 08-Feb-19 01:13 PM oh my 08-Feb-19 01:14 PM They had some work done recently because one of the safety's wouldn't disengage 08-Feb-19 01:14 PM And my guess is instead of fixing the problem they just bypassed everything 08-Feb-19 01:16 PM Aaaaaaaand...it's dead. 08-Feb-19 01:20 PM So is the verdict gona be "All your equipment is now scrap" 08-Feb-19 01:20 PM No 08-Feb-19 01:20 PM I'll fix it 08-Feb-19 01:32 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/descarga_3-88511.jpeg 08-Feb-19 01:32 PM had to be imaged 08-Feb-19 01:32 PM /not sorry at all/ 08-Feb-19 01:39 PM Snow storm started 08-Feb-19 01:39 PM found a leak + rip in the roof 08-Feb-19 01:39 PM but no worries since it is able to drain 08-Feb-19 01:39 PM and I will be replacing (have the wood and new weatherproofing on hand) it anyways 08-Feb-19 02:52 PM Snow storm started here too. 08-Feb-19 03:00 PM Yeah same here. SEM is supper not happy about starting up in the snow 08-Feb-19 03:04 PM I just pictured you SEMing something outside. 08-Feb-19 03:04 PM I have literally run ice and snow in one before 08-Feb-19 03:04 PM That was a pised off instrument 08-Feb-19 03:06 PM XD 09-Feb-19 08:32 AM Okay, stupid question. 09-Feb-19 08:32 AM How much does the deflection plates size matter for electrostatic electron beam deflection? 09-Feb-19 08:32 AM wait. let me explain. 09-Feb-19 08:32 AM I notticed that the first plates are smaller than the second plates on my scope CRT tube. Given that those are designed to deflect the beam varous centimeters (at end of travel), but I only need to deflect it 1cm or so, Can I just make both of them smaller? 09-Feb-19 08:32 AM I have the feeling that the actual lenght of the plates is more important. (lenght as in the axis of the beam, so the field can actually affect the beam). 09-Feb-19 08:32 AM Also, I understand that the second plates (further away from the beam generator) are wider because the beam will move side to side in them, whereas the first plates have just to move the beam from center. 09-Feb-19 08:32 AM I also notticed that the secondary plates, have one of them with a U shape 09-Feb-19 08:32 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-5D2C9.png 09-Feb-19 08:32 AM Is that to prevent the beam from going too far to the sides? (first plates are just parallel plates, no U shape on any of the two). 09-Feb-19 08:32 AM If so, since my deflections are very small in comparison, can I get away without it? 09-Feb-19 10:42 AM Hrm, should I get a Variable Leak Valve from this guy? Not sure what I'd be needing it for other than I suppose getting to an exact vacuum? 09-Feb-19 10:42 AM https://www.agilent.com/en/products/vacuum-technologies/vacuum-components/vacuum-valves/variable-leak-valve#productdetails 09-Feb-19 10:42 AM know a guy who has this one it looks like anyway, for sale 09-Feb-19 10:42 AM Suppose could use it for letting gas in at a controlled rate 09-Feb-19 10:49 AM @Nixie The plate geometry will determine the shape of the field. The potential you apply will determine the magnitude. It's tough to day without modeling though. In specific, which plates are used for what deflection? Are the first small plates vertical, the second wide ones horizontal? Focusing, etc? Chances are plates are wider further from the beam in part to account for beam divergence 09-Feb-19 11:32 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190209_203134-8804B.jpg 09-Feb-19 11:32 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190209_203109-12BF0.jpg 09-Feb-19 11:32 AM Yes, secondary plates are "longer" than the primary, also slightly wider. 09-Feb-19 11:32 AM I will probably just remove plates like these and use them as is. 09-Feb-19 11:32 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-A15A1.png 09-Feb-19 11:32 AM Thats the plates for a miniature 3LO1I tube. 09-Feb-19 11:32 AM what metal should I make the plates, if I try to make them myself? (for the lulz) 09-Feb-19 11:50 AM The extra pictures help, makes more sense now lol. In terms of metal, you can probably just use anything for this purpose. For a gun like this I don't think metal selection is critical at all, especially for plate deflectors 09-Feb-19 11:54 AM Nice! I might use stainless for trials then. 09-Feb-19 11:54 AM (because I have thin sheet) 09-Feb-19 11:54 AM I'll try to mimic the aspect ratios and such. 09-Feb-19 11:54 AM (in any case, my deflections are going to be much smaller than a normal electrostatic CRT) 09-Feb-19 11:57 AM Stainless would be perfect, probably what they already use. Low outgassing, easy to spot weld. 09-Feb-19 11:57 AM 09-Feb-19 11:57 AM At some point, if this manages to work, I'll ask for help redesigning te whole electronics, to make a complete independent assembly. 09-Feb-19 11:57 AM (Btw, the stainless I have is from SMT stencils. XDDDD) 09-Feb-19 12:22 PM @Applied_Ion How can I know the deflection of the beam vs the voltage aplied? (like, where do I find info about that) 09-Feb-19 12:22 PM like this? 09-Feb-19 12:22 PM http://practicalphysics.org/deflection-electric-fields.html 09-Feb-19 12:22 PM Where, Vd is the voltage in the plates, d is the distance between plates and Va is voltage acceleration 09-Feb-19 12:22 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-28DE0.png 09-Feb-19 12:22 PM But is y an angle of deflection? 09-Feb-19 12:47 PM Yes that can work, though in this case y is the vertical distance deflected. For parallel plate deflectors, you can reasonably calculate electron deflection without much difficulty. Other focusing and gun optics are much more challenging and generally require some field modelling. But parallel plate stuff doesn't really need it as much 09-Feb-19 01:32 PM snow 09-Feb-19 01:32 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0073-4A97B.jpg 09-Feb-19 01:32 PM just went up on the roof and patched two holes from the tree falling on the house on monday 09-Feb-19 01:32 PM noticed a leak yesterday, patched up the main rip, then we got 6" of snow and the dirp continued 09-Feb-19 01:32 PM found the holes easily enough as it was melted all around 09-Feb-19 03:41 PM @Applied_Ion but that vertical deflection calculation in wich distance is it applied? Like, that will be at the end of the plate? 09-Feb-19 03:41 PM And the plates have to be apart enough as to not touch the beam, I assume. 09-Feb-19 03:41 PM (or be shorter, maybe) 09-Feb-19 03:48 PM That's where modeling comes in to help lol. I'm not sure where the point of deflection would start. You can calculate the max deflection, but it won't tell you how the field is shaped exactly between the plates and the exact trajectory the electrons would travel. You could also figure this out experimentally though. Make a phosphor target screen, and measure deflection vs voltage to come up with your own curves 09-Feb-19 03:49 PM 09-Feb-19 03:49 PM Will do! Thanks. 09-Feb-19 03:54 PM I'd say the experimental part is where you will learn the most. At this level the optics don't have to be crazy precise, and you can probably achieve your goal just messing around with it and observing trends. Something like Poisson Superfish will give fields, but that's still not helpful without some particle trace solver, which are either expensive or very challenging to use. For my system, I will probably model the field strength to make sure I am at the appropriate levels needed for my system, but other than that I will be optimizing the beam through trial and error. 09-Feb-19 03:54 PM Lots of trial and error... 09-Feb-19 11:10 PM Well, as a jobless person, I have the time to do lots of that! 09-Feb-19 11:10 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/PCQHMc-A3D00.gif 09-Feb-19 11:57 PM Can anyone recommend a gross vacuum gauge? Or are there any you should stay away from? XD 10-Feb-19 12:02 AM Gross? Hm...my SVG3 works nice, BUT it has a SAE connector and I had to make an adaptor for my KF16 circuit. 10-Feb-19 12:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/descarga_4-635EB.jpeg 10-Feb-19 12:32 AM I'd recommend the MKS 901P they can be had for 20-50 dollars, 50 dollars easy all day long. They are serial, has software you can download from MKS directly, you have to make up a cable from DB15 but thats easy. It also has 3 relay setpoints for system control and it has a voltage output with a linear pressure reference if you don't want to use serial even. 10-Feb-19 12:32 AM There are lots of models though so reference one of the docs like this one: https://www.mksinst.com/docs/UR/HPS901ds.pdf On which model your looking at on ePay to make sure your getting the features/interface you need/want. 10-Feb-19 12:32 AM they also have different HV interface, KF16 being most common it seems 10-Feb-19 12:32 AM https://www.ebay.com/itm/MKS-VACUUM-LOADLOCK-TRANSDUCER-901P-11040-Money-Back-Guarantee/253958599268 10-Feb-19 12:32 AM It does require a 9-30V input though for reference. 10-Feb-19 12:39 AM Dammit...I need to invent a teleportation device. (And ruin all shipping companies) 10-Feb-19 12:40 AM But with that and a serial line to a winblows box you can get the MKS software for it here: https://www.mksinst.com/vtsw/ 10-Feb-19 12:53 AM good morning! 10-Feb-19 12:53 AM wanted to order one of these MKS gauges for some time now, never got around to do it 10-Feb-19 02:28 AM moin 10-Feb-19 02:29 AM доброе утро 10-Feb-19 02:31 AM priwjet! 10-Feb-19 02:32 AM Mining! 10-Feb-19 03:50 AM Moin moin 10-Feb-19 08:22 AM coin! 10-Feb-19 10:01 AM Man its killing me, I think I have everything for my custom chamber, EXCEPT for the adapter I need to attach my turbo in any way... 10-Feb-19 10:01 AM I should have not gotten an NW attach turbo... Uhg... 10-Feb-19 10:10 AM The tyranny of plumbing. I'm always getting a good deal on this or that major component and then end up spending more on adapters and fittings to hook things up. Prices are good on the basic KF components like tees and so on, but if you want a KF to VCR adapter, or even KF to NPT there are a lot fewer vendors and prices jump. 10-Feb-19 10:13 AM yea... 10-Feb-19 10:13 AM The problem is the piece I need is fairly specific, NW160 to CF 6" or CF 8" if I really have to, then I'll probably need a CF 8" T 10-Feb-19 11:30 AM Yeah, that was a massive cost for my system as well. Needed the custom adapter plates to adapt from the diff pump, to baffle, to 6" conflat. Diff pump was free, chambers were mostly free, the baffle was $100, and the adapters cost an arm and a leg... 10-Feb-19 12:14 PM oof 10-Feb-19 01:39 PM The top of my broken SEM is turning into a surface for storing things. Not a good sign! 10-Feb-19 01:40 PM We have got to get that thing going 10-Feb-19 01:42 PM Every vacuum joint I can reach seems tight... I'm wondering if there's a malfunctioning valve... Self-test in the software says all the valves work, but one of them doesn't seem to make much/any clicking noise during the test. Pretty sure self-test is just checking for electrical abnormalities. 10-Feb-19 01:47 PM Tight doesnt matter 10-Feb-19 01:47 PM quality of the seal is where you find leaks 10-Feb-19 01:47 PM and overtighten can cause leaks 10-Feb-19 01:47 PM Things like cracks forming in o rings or fibers laying across orings is likely what you are going to see 10-Feb-19 01:56 PM My master plan is to just pay @AdamMcCombs to fix it for me. 10-Feb-19 01:57 PM We we can do that or I have a ISI S3A, a 35C, and JSM6400 looking for a home... 10-Feb-19 01:57 PM Well maybe an 840 instead of a 6400 looking for a home. One of the two 10-Feb-19 01:57 PM They aren't what I would call apartment scopes though... 10-Feb-19 02:00 PM Yeah I think I only have space for a desktop scope.... for now... 10-Feb-19 02:01 PM Yeah. I think im just going to have to start Adams home for wayward scopes 10-Feb-19 02:07 PM I think it would be good for you to get experience with desktop scopes. 10-Feb-19 05:19 PM Test point on the Pirani gauge during sample chamber pump down.... 10-Feb-19 05:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_1347-498D1.JPG 10-Feb-19 05:21 PM When does it switch over to high vac? 10-Feb-19 05:21 PM When the curve slows down? 10-Feb-19 05:24 PM Well there's no audible valve switching noise, and according to the vacuum system display, it seems like it's using the TMP to pump the sample chamber from the beginning. 10-Feb-19 05:24 PM Hm 10-Feb-19 05:24 PM That's interesting 10-Feb-19 05:24 PM Is there 24v on the valve? 10-Feb-19 05:25 PM I tested all the valves with a 24V supply and they all make kerchunking sounds 10-Feb-19 05:25 PM Not sure if that means they're working properly, but they make noise at least 10-Feb-19 05:26 PM Ok I have an idea but am going to need to explain it over voice. For now get and keep the system pumping 10-Feb-19 05:26 PM There's a bit of a kink/dip in the test point reading now.... dipped down, now going back up. Around 2.8V now... 10-Feb-19 05:26 PM *2.68V 10-Feb-19 05:29 PM Also make sure the valve is getting 24v 10-Feb-19 05:30 PM I don't think there's any test points for the valves... I closed the swing out portions before firing up the scope.. not sure if it's meant to run with the sides swung open. 10-Feb-19 05:30 PM I'm probably a bit conservative still with messing with this thing. 10-Feb-19 05:31 PM Yeah as long as nothing is shorted, disconnected, and you are comfortable working around equipment with the covers of you are fine 10-Feb-19 05:31 PM I run scopes with guts sprawled out on the bench so you should be fine 10-Feb-19 05:32 PM Until a few months ago I considered SEMs to be magic boxes full of unobtanium 10-Feb-19 05:33 PM Eh 10-Feb-19 05:33 PM They are boxes full of parts built to a cost and made to be serviced 10-Feb-19 05:34 PM Left side open 10-Feb-19 05:34 PM Pirani up to 2.71V 10-Feb-19 05:34 PM No idea what that correlates to though 10-Feb-19 05:35 PM TMP running? 10-Feb-19 05:36 PM Man it's a lot more convenient to tap into a test point than deal with my own pirani gauge 10-Feb-19 05:36 PM Yeah TMP is running 10-Feb-19 05:36 PM Photo of valve page? 10-Feb-19 05:38 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_1348-2CF43.JPG 10-Feb-19 05:38 PM Not sure if I always trust the valve page. Right now it says column is low vacuum but usually when I vent chamber, the page updates and shows column at high vacuum. 10-Feb-19 05:39 PM That makes sense actualy 10-Feb-19 05:40 PM It shows V2 as closed even from the very beginning of pumping... so I've never seen the state change where it closes V2 and opens V1 10-Feb-19 05:41 PM exciting stuff going on in here tonight 10-Feb-19 05:42 PM Hm 10-Feb-19 05:42 PM Should I keep pumping? 10-Feb-19 05:42 PM yeah 10-Feb-19 05:43 PM There's also a high pitched sound from the TMP area that is intermittently off for maybe 100ms every second 10-Feb-19 05:43 PM Click the show results tab 10-Feb-19 05:44 PM That just shows saved results from previous tests. Everything passes until it reaches part of the test that needs high vacuum in sample chamber 10-Feb-19 05:45 PM Can you show me the data though? 10-Feb-19 05:46 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_1349-71974.JPG 10-Feb-19 05:46 PM Oh wait, other results showed the RP/TMP test passing. I may have shown you results that I aborted. 10-Feb-19 05:51 PM What does the HV check do? 10-Feb-19 05:51 PM high vac 10-Feb-19 05:52 PM Yes, but what do the valves do when it does that 10-Feb-19 05:52 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_1351-B06F2.JPG 10-Feb-19 05:52 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_1352-A5C08.JPG 10-Feb-19 05:52 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_1350-9E648.JPG 10-Feb-19 05:52 PM I have a video running the test but might be too big to upload here? 10-Feb-19 05:52 PM It clicks through all the valves and then starts pumping down to do the HV tests. I don't think I can access the vacuum system screen while it's running the test. 10-Feb-19 05:52 PM Might be able to, but I'll have to vent sample chamber to start the test and find out. 11-Feb-19 01:16 AM yawn Good morning! 11-Feb-19 01:30 AM Bloing bloing! 11-Feb-19 01:30 AM moin 11-Feb-19 02:21 AM moinsen! 11-Feb-19 04:53 AM Does anyone know how to calculate the counterpressure resistance of a round glass window VS thickness? 11-Feb-19 04:53 AM Because I know that putting a 10mm thick window in the dodecaedron vacuum chamber is past overkill. 11-Feb-19 04:53 AM But the next cheap option is 4mm thick. 11-Feb-19 04:53 AM We are talking borosilicate all the time, btw. 11-Feb-19 04:53 AM The window itself would rest in an o-ring, so should not have hard contact points that can induce breaking on the edges. 11-Feb-19 04:53 AM (I posted a model in #machining , heres a small image of what I am talking about: 11-Feb-19 04:53 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-69509.png 11-Feb-19 04:53 AM It's not that the 10mm thick windows are too expensive (8 vs 10€, from a reputable europe glass seller) but that if I can get away with thinner glass because it's a few times strong enough, I'll also save weight, etc... 11-Feb-19 05:33 AM Also, checked the glass diameter and it is noth 100mm, but 117mm. The thing becomes even more huge. 11-Feb-19 05:33 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-BA70C.png 11-Feb-19 06:14 AM Just found this calculator, is it good? 11-Feb-19 06:14 AM https://www.swiftglass.com/psi-calculator-for-sight-glass-discs 11-Feb-19 06:14 AM It says that for an unsupported diameter of 112,5mm, the glass should be about 8mm in thickness. 11-Feb-19 06:16 AM If you are doing plasma, heating, or high voltage stuff inside you need to take some more things into consideration with the glass 11-Feb-19 06:18 AM sits and takes notes 11-Feb-19 06:18 AM yes? 11-Feb-19 06:18 AM Risk is heating/physical damage 11-Feb-19 06:18 AM Heating from plasma ect, and surface charging and discharge 11-Feb-19 06:18 AM View ports in systems with high charging potential need to be coated with something to enable charge disapation, and x rays are also a concern 11-Feb-19 06:18 AM Heating can cause differential expansion and thus leads to a potential for failure 11-Feb-19 06:21 AM Hmmm...so at least it's back to the 10mm thickness, at least. 11-Feb-19 06:21 AM Plasma etching is also a concern, can etch micro cracks and cause local failure 11-Feb-19 06:21 AM That then propagates... 11-Feb-19 06:22 AM scribbling fast in his notebook 11-Feb-19 06:22 AM yes, yes 11-Feb-19 06:22 AM Well...10mm thick AND only 109mm in diameter. 11-Feb-19 06:22 AM (they name both glasses a 4" diameter, but diameters vary wildly between thicknesses :/ ) 11-Feb-19 06:22 AM The thing is still going to be huge, AND have at least 100mm in diameter to fit the hands/experiments. 11-Feb-19 06:52 AM lol 11-Feb-19 06:52 AM I contacted pfeiffer about the replacement bearing for the tmp 11-Feb-19 06:53 AM How expensive? 11-Feb-19 06:54 AM they responded that they are not allowed to sell me the requested replacement part (ball bearing) until I complete a course at their office 11-Feb-19 06:54 AM Well 11-Feb-19 06:54 AM That's special 11-Feb-19 06:55 AM the actual part is affordable (48€) but they can only sell it to my when a service technician does the replacement 11-Feb-19 06:55 AM which costs 670€ 11-Feb-19 06:56 AM Contact duniway stockroom 11-Feb-19 06:56 AM so either I take that course (I don't know the costs for that) or they do the replacement by sending a technician 11-Feb-19 06:56 AM I replyied to them that I already took apart the pump multiple times without an issue... But I don't think that helps 11-Feb-19 06:59 AM A bearing with similar properties you can just order somewhere doesn't exist, I guess? ^^ 11-Feb-19 06:59 AM I don't think so 11-Feb-19 07:08 AM I'd call that extorsion. 11-Feb-19 07:09 AM Or lawyers 11-Feb-19 07:24 AM Wow, that's pretty messed up. What are the specs for the bearing? 11-Feb-19 07:30 AM I will have to take it apart again and take exact measurements 11-Feb-19 07:30 AM I would guess 10mm inner diameter 30mm outer diameter 11-Feb-19 07:30 AM highest precision, 90000rpm 11-Feb-19 07:30 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190204_122924-2FEAF.jpg 11-Feb-19 07:35 AM It's really crazy they are making it so inaccessible to get. You would think that if someone knew that the bearing was the issue with a tmp and can take it apart, they probably know what they are doing lol. If you own the pump yourself, I can't see why they care if you take it apart yourself or not. 11-Feb-19 07:35 AM Is it just the size that is difficult to find, or the fact that it's high precision? Does it look like it's some super custom fit part? 11-Feb-19 07:38 AM The most important key pareters is precision, max speed, lubrication and bearing type 11-Feb-19 07:38 AM Ball bearings are tricky 11-Feb-19 07:39 AM Have you tried maybe searching for model jet turbine bearings if there is a size similar? Those are definitely rated for the speed and stresses, well over 100k rpm and high precision 11-Feb-19 07:39 AM Especially for such applications 11-Feb-19 07:39 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190211_163942_748-E0048.jpg 11-Feb-19 07:39 AM First to to will be finding out what forces the bearing has totake 11-Feb-19 07:39 AM Afair it is preloaded so I probably need an open precision angular contact hybrid spindle bearing 11-Feb-19 07:39 AM That is compatible to the used lubricant in the pump 11-Feb-19 07:39 AM bearings are a science in itself 11-Feb-19 07:47 AM I know this probably wouldn't be an exact fit, but maybe something similar? Open style, preloaded bearing, angular contact, 10mm ID, 26mm OD, 90-100k RPM, 153KGF dynamic load: https://www.bocabearings.com/products/d6000-602c-4283 11-Feb-19 07:47 AM These types of bearings have to handle much more extreme conditions than in a tmp at the same RPM level with heavier loading and dynamic stresses (especially for in-flight use), and are much easier to come by. Not cheap, but not crazy expensive either all things considered. 11-Feb-19 08:11 AM might work, thanks for the idea 11-Feb-19 08:20 AM No problem, hopefully something like this could work, or you can find some equivalent replacement and not worry about pfeiffer's utter nonsense. 11-Feb-19 08:32 AM groin! 11-Feb-19 09:47 AM Forget about using normal bearings or chinese hybrid ones. 11-Feb-19 09:47 AM I have rebuilt two of my pumps for bearing issues, upwards of 50k you really need the right ones if you plan on any sort of lifetime 11-Feb-19 09:47 AM use normal high quality skf steel bearings for testing and decide if its worth it, they will survive a few minnutes to one hour in the tmp but look out for vibrations and unusual noise 11-Feb-19 09:47 AM i have run my varian tv81m on home made bearings for over 100h but they need constant attention and relubrication if you dont have bearings made for this purpose. 11-Feb-19 09:47 AM the biggest issue is the expansion of the cage andthereby increased friction against the balls wich will heat the cage 11-Feb-19 09:47 AM in air thats no issue but in vacuum the cunduction fro cage to outer ring is nonexistant 11-Feb-19 09:47 AM the gnm bearings utilize cotton/phenolicresin "plastic" impregnated with oil for a lifetime lubrication and high mechanical strength 11-Feb-19 10:09 AM what do you think about using those turbine bearings? 11-Feb-19 10:09 AM my pump uses oil fog cooling 11-Feb-19 10:15 AM I'd say in terms of tolerances and specs turbine bearings may be a solid option to consider, they seem very similar to what you require (in addition that both tmp and jet engines are forms of turbomachinery. Different use cases, but still very stringent specs and requirements needed) 11-Feb-19 10:15 AM I've never rebuilt or serviced a tmp before though, so just a suggestion based on your needs and what is accessible on the market. 11-Feb-19 10:56 AM https://tenor.com/view/jonah-hill-yay-greek-aldos-gif-7212866 11-Feb-19 10:56 AM Just the thought I might have an SEM by the end of the week <3 11-Feb-19 10:56 AM Though I may jinx it... I have a handy strip of wood of the front of my desk at work to knock on so I should be fine. lol 11-Feb-19 10:56 AM If anything it'll happen, it'll just cost more and be harder than I thought. 11-Feb-19 11:14 AM I actually was able to turn on the beam on my SEM last night thanks to amazing help from @AdamMcCombs 11-Feb-19 11:15 AM CONMEGAGRATS! 11-Feb-19 11:15 AM 11-Feb-19 11:17 AM awesome! 11-Feb-19 11:17 AM now we want some fotos 11-Feb-19 11:19 AM I have to resolve some firewire issues before I can get a picture. Some sort of data transfer mode the scope uses that my computer isn't properly handling. 11-Feb-19 12:09 PM Yeah haha have fun with FireWire 11-Feb-19 12:15 PM Yea sorry piGuy but I loled once the amazing story of getting your SEM up ended with a And now he has to fix a firewire issue so anticlimactic XD 11-Feb-19 12:24 PM Hey I'm just happy to make progress and find a new issue to resolve. 11-Feb-19 12:58 PM Oooooh, I switched to legacy firewire driver and now I can pass the firewire self test! 11-Feb-19 12:58 PM Ah the ahc or whatever complient driver? 11-Feb-19 01:00 PM Not sure what's different about it, there's just a normal driver and one with "(legacy)" appended to the driver name. Apparently a lot of firewire devices don't work in Windows 7 if you don't use the legacy driver 11-Feb-19 01:00 PM Yeah it's common on TEM camera systems I should have mentioned it for you 11-Feb-19 01:02 PM Stupid question: is the sample chamber shielded for x-rays? Is there a way I can unintentionally expose myself? 11-Feb-19 01:02 PM Yeah 11-Feb-19 01:02 PM 30kv is pretty weak 11-Feb-19 01:03 PM I think it only goes to 15kV 11-Feb-19 01:03 PM Even more so 11-Feb-19 01:03 PM So do you know about filament heating saturation curves? 11-Feb-19 01:04 PM So should I pump it down and try to get a presumably blurred and unfocused image? 11-Feb-19 01:04 PM I do not 11-Feb-19 01:04 PM Learn as much as you can about filament saturation first 11-Feb-19 01:04 PM There's a lot of stuff you have to do when bringing the filament up the first time on an unaligned column 11-Feb-19 01:07 PM I know there's an alignment procedure with thumbscrews 11-Feb-19 01:08 PM Problem is it's hard to saturate a beam with a bad alignment, which is what you have to do 11-Feb-19 01:09 PM Is it possible my machine is dumbed down enough to prevent me from being able to screw things up? I think it's designed do more handholding for the user... 11-Feb-19 01:10 PM Uh 11-Feb-19 01:10 PM Kinda 11-Feb-19 01:10 PM It will probably let you blow out a filament or cause excessive pmt/scintillator ware 11-Feb-19 01:11 PM Hm okay 11-Feb-19 01:11 PM Maybe I should read the manual again 11-Feb-19 01:11 PM I'M SO EXCITED!!!!!!! 11-Feb-19 02:08 PM Do SEM parts really need to be replaced this often? 11-Feb-19 02:08 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-E0F74.png 11-Feb-19 02:09 PM For a system seeing heavy use yeah 11-Feb-19 02:09 PM Sometimes even more frequently 11-Feb-19 03:21 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_1361-13E22.JPG 11-Feb-19 03:21 PM Don't know what the heck I'm looking at, but it's something! 11-Feb-19 03:22 PM Final appurature and stage probably 11-Feb-19 03:22 PM Scope automatically turns filament on after reaching HV, so can't really avoid, just letting her rip 11-Feb-19 03:23 PM Try a stage move 11-Feb-19 03:23 PM Mmmmmm 11-Feb-19 03:23 PM That's disappointing 11-Feb-19 03:23 PM But ok 11-Feb-19 03:23 PM What does the filament image look like? 11-Feb-19 03:24 PM Ah yeah the stage moves! 11-Feb-19 03:25 PM Well time to get a sample in and learn about stigmators! 11-Feb-19 03:26 PM 11-Feb-19 03:27 PM Bring voltage up to 15 (with a pause a 10) and everything will get easier 11-Feb-19 04:14 PM so much snow 11-Feb-19 04:22 PM It's nuts 11-Feb-19 04:41 PM No,no, snow. 11-Feb-19 04:47 PM school will be cancelled again 11-Feb-19 05:33 PM just got cancelled 11-Feb-19 05:49 PM Any more sem images? 11-Feb-19 06:18 PM Not yet, I think I want to button it up before I play with it more 11-Feb-19 06:18 PM Getting distracted by snowmageddon coverage 11-Feb-19 06:34 PM fun to run around the streets 11-Feb-19 06:34 PM kids were sledding 11-Feb-19 06:34 PM down streets 11-Feb-19 06:34 PM not hills 11-Feb-19 07:25 PM News guy said 5th snowiest month in Seattle history, and we're only 11 days in!! 11-Feb-19 10:33 PM heh... leme know when you have snow drifts up to the windows on small SUVs 11-Feb-19 10:33 PM That was NOT a fun winter here... 11-Feb-19 10:33 PM https://i.imgur.com/UhbyEpc.jpg 12-Feb-19 12:47 AM Guten morgen! 12-Feb-19 01:58 AM German is not a language that deserves any support. Change my mind. 12-Feb-19 02:02 AM by now I'm pretty sure that the majority here speaks german 12-Feb-19 02:03 AM yeah, still I don't like the German language nor culture 12-Feb-19 02:03 AM there is a german culture? 12-Feb-19 02:03 AM exactly 12-Feb-19 02:03 AM oh, I forgot, beer, conservatism and slow internet 12-Feb-19 02:03 AM well, actually German does have culture, at least some parts of it 12-Feb-19 02:03 AM and it's all horrible 12-Feb-19 02:03 AM Oktoberfest, Weißwurst, Sauerkraut 12-Feb-19 02:04 AM german culture is not letting someone order replacement parts because that one is not 'qualified' to put them in his turbo pump ^^ 12-Feb-19 02:04 AM that's bavaria 12-Feb-19 02:04 AM yep 12-Feb-19 02:04 AM Sauerkraut is very north Germany 12-Feb-19 02:04 AM oh, is it? 12-Feb-19 02:04 AM or Kohl 12-Feb-19 02:04 AM Grünkohl is northern germany as well right? 12-Feb-19 02:04 AM everything that grows without sunlight 12-Feb-19 02:04 AM both are extremly common down here 12-Feb-19 02:04 AM wihich tells alot about life quality there 12-Feb-19 02:04 AM Also, the language sucks. I don't understand why we just make a clean cut and chnage to English or Chinese as the official language 12-Feb-19 02:04 AM people can still talk German if they feel like it, but why do we teach children a language that encapsulates them within a small country? 12-Feb-19 02:09 AM german's fine, just get rid of bavarian and similar dialects 12-Feb-19 02:35 AM 3 things: Morning! I speak 3 languages, one of them is an "encapsulative" one, but also happens to make me understand a written fourth. Learning languages expands your mind and flexes your brain. We should move this to #off-topic-thats-sometimes-on-topic 12-Feb-19 08:37 AM moin! 12-Feb-19 11:05 AM Welp I "kinda" own a scope! yay 12-Feb-19 11:05 AM define scope, it has too many meanings in this group 12-Feb-19 11:26 AM https://www.ebay.com/itm/Scanning-Electron-Microscope-/192676386408?_trksid=p2047675.m43663.l10137&nordt=true&rt=nc&orig_cvip=true 12-Feb-19 11:26 AM made a deal, picking it up Friday with Adam hopefully :) 12-Feb-19 11:27 AM cool! 12-Feb-19 11:27 AM have fun, good luck 12-Feb-19 11:27 AM lol yea luck will be necessary 12-Feb-19 11:28 AM I can only imagine 12-Feb-19 11:28 AM saw some pics of adam moving scopes 12-Feb-19 11:48 AM Nice! 12-Feb-19 11:52 AM https://imgur.com/a/Ix1Onv9 12-Feb-19 11:52 AM also 12-Feb-19 11:52 AM this came in 12-Feb-19 11:52 AM thats an album 12-Feb-19 11:55 AM Awesome! So is it looking like it's a confirmed sputter head? 12-Feb-19 11:56 AM oh yea for sure 12-Feb-19 11:56 AM there is metal flaking off the inside of the chamber 12-Feb-19 11:56 AM and its plated on the viewport too LOL 12-Feb-19 11:56 AM Sounds like your gamble paid off 12-Feb-19 11:57 AM yea well the real gamble is once we get some of the metal into my SEM and find out what EDS says about it :) 12-Feb-19 11:57 AM knife edge on the open end looks NICE though 12-Feb-19 11:57 AM so you'll have a nice fully rotatable 6" 6" 2.75" T 12-Feb-19 11:58 AM So you still interested in splitting the head and the tee? 12-Feb-19 11:59 AM Yea I mean, it is a NICE T, but I know you need it for your chamber, I've been mostly aiming for 8" stuff for my chamber anyway, I have an 8/8/6 T as it is, I'd probably wait for another or something similar to attach the head to my chamber 12-Feb-19 11:59 AM and the head doesn't jut down into the T much at all, like maybe a quarter inch? 12-Feb-19 11:59 AM not even? 12-Feb-19 11:59 AM so I really don't need the height I don't think 12-Feb-19 11:59 AM so yea, lets help get your chamber up and going and worry about mine later :P I have an SEM to worry about here soon anyway lol 12-Feb-19 11:59 AM I just hope I can get the stainless steel bolts off... 12-Feb-19 11:59 AM I really hope they aren't galled up 12-Feb-19 12:08 PM Wow, thanks again so much, you have no idea how much of a massive help this is! Like you have literally made it possible for me to set up a TOF beamline for high energy particle measurements, as well as modifying my original beamline for beam transport efficiency measurements. 12-Feb-19 12:10 PM :) 12-Feb-19 12:10 PM now this thing is only 4.5" log from 6" to 6" for reference btw 12-Feb-19 12:10 PM so take that into account 12-Feb-19 12:10 PM if you need a straight 6" exstention... the guy has one 12-Feb-19 12:17 PM Short is actually better for this part of the beamline. I will need to get additional extensions, but the 2.75" port is needed here at least for a diagnostic input. This attaches to the end of the accelerator tee, and another extension pipe will attach after as a long drift tube with a Faraday cup at the end for the MEVI beamline. 12-Feb-19 12:17 PM Actually so far in all, I have 8 different systems in the works that the main accelerator will drive. MEVI is one of the most important, but there are 7 other experiments that use the main EXEDA accelerator as the driver 12-Feb-19 12:17 PM I will definitely reach out to the ebay seller and ask about any 6" extensions he has for sure. 12-Feb-19 12:23 PM he has one, I can post photos 12-Feb-19 12:23 PM BTW @Conmega how much did you want for the tee? 12-Feb-19 12:23 PM That would be great too if u have pics 12-Feb-19 12:24 PM I payed like 100 shipped for everything, so like 40 bucks plus shipping I guess? Or I can drop it off when I'm in Albany sometimes. 12-Feb-19 12:24 PM so just like 40 bucks I suppose 12-Feb-19 12:24 PM sound fair? 12-Feb-19 12:24 PM https://i.ebayimg.com/images/g/mEMAAOSw6HJcYD2U/s-l1600.jpg https://i.ebayimg.com/images/g/zsUAAOSwQpVcYD2n/s-l1600.jpg https://i.ebayimg.com/images/g/bm0AAOSwJtNcYD2x/s-l1600.jpg 12-Feb-19 12:25 PM I'll pay 50, said I'd cover half the sihpping before lol 12-Feb-19 12:25 PM ok lol sure 50 bucks 12-Feb-19 12:25 PM and there are I think all the photos of that 6" extension 12-Feb-19 12:25 PM so far everything I've gotten from this guy has had clean knife edges, like as if it was just removed from the piece 12-Feb-19 12:25 PM packaging has been... minimal... but haven't had any bad time yet 12-Feb-19 12:25 PM he is in NY state so it doesn't go far 12-Feb-19 12:26 PM Nice, thanks a bunch! Sounds like this guy has a decent stock at least 12-Feb-19 12:26 PM also you'll want to wire brush the inside of this chamber to get all the plating off lol 12-Feb-19 12:26 PM I may do that if I find out this source is silver or platinum or some precious metal :) 12-Feb-19 12:26 PM yea he keeps sending me photos of stuff 12-Feb-19 12:26 PM like this... 12-Feb-19 12:26 PM https://i.ebayimg.com/images/g/QwIAAOSwQpVcYtF1/s-l1600.jpg 12-Feb-19 12:26 PM https://i.ebayimg.com/images/g/djsAAOSwdwlcYtGA/s-l1600.jpg 12-Feb-19 12:26 PM cutest little sputter head 12-Feb-19 12:26 PM its just freakin adorable XD 12-Feb-19 12:26 PM https://i.ebayimg.com/images/g/0~0AAOSwWbZcYtF8/s-l1600.jpg 12-Feb-19 12:28 PM Eh, the inside plating won't affect me really, probably just wipe down with acetone and alcohol. 12-Feb-19 12:28 PM Pretty cool little sputter head lol 12-Feb-19 12:29 PM yea but some of the plating is flaking off... so you'd probably want to clear that out at-least :) 12-Feb-19 12:30 PM Oh yeah, I guess if it's actually flaking off in chunks 12-Feb-19 12:30 PM yea it is 12-Feb-19 12:30 PM but also hrm I'm really tempted by that little sputter head but if he realizes thats probably gold... uhg 12-Feb-19 12:31 PM Don't mention gold lol 12-Feb-19 12:31 PM alright I have to go shovel snow... I'll be back later o/ 12-Feb-19 12:31 PM I wasn't going to I just said its interesting, and asked what he was looking to get for it 12-Feb-19 12:31 PM he asked for higher on the leak valve last time so he knows what stuff is he just doesn't really let on to it 12-Feb-19 12:33 PM I really don't want to shovel... 12-Feb-19 12:59 PM I need more photos of the miniature sputter head...for reasons. 12-Feb-19 12:59 PM pins medal for guessing correctly about the big sputtering head 12-Feb-19 10:23 PM moin 12-Feb-19 10:29 PM Gloin! 12-Feb-19 11:22 PM moin 13-Feb-19 03:48 AM moin! 13-Feb-19 03:57 AM Does anyone have an idea how to take apart this epoxied plumbing? I tried clamping the 90° angle of the tc gauge in a vise and then turn the cross, but it is too strong. I want to attach the tc gauge directly to the kf connector 13-Feb-19 03:57 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20190213_125412-FA64D.jpg 13-Feb-19 03:59 AM Hm...heat it somehow? and then brute force? 13-Feb-19 04:01 AM Yeah was thinking about that too, but what about the tc gauge? How much heat can I use on it? 13-Feb-19 04:03 AM Maybe protect it with a fiberglass cloth/aluminium sheet combo 13-Feb-19 04:03 AM Also, there are epoxy solvents out there, but I am not sure if they would damage the gauge (by inmersion, I mean) 13-Feb-19 04:07 AM the gauge should be made with baking in mind 13-Feb-19 04:09 AM How hot can baking be? 13-Feb-19 04:10 AM 200ºC for CF systems? 13-Feb-19 04:10 AM Hm that's nice. I think I'll try it with a bit of protection, then see how much heat it really needs. 13-Feb-19 04:11 AM (don't take that as a definitive answer! wait for the pros to check it) 13-Feb-19 04:23 AM Tested it on a different part and it worked very well, temperature was a bit over 100°C (82 according to my ir thermometer but I think it was more) 13-Feb-19 04:23 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20190213_131649-CE2B5.jpg 13-Feb-19 04:45 AM Nice! 13-Feb-19 05:41 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20190213_143659-0F65F.jpg 13-Feb-19 05:41 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20190213_143959-5567C.jpg 13-Feb-19 05:41 AM First test 13-Feb-19 05:41 AM So the gauge is not calibrated, but it's still showing something! Had to wait a bit until it bottomed out at 1.0 e-3 torr. Doesn't look like much but I'm still very happy 13-Feb-19 05:47 AM Good! 13-Feb-19 06:26 AM Oh! 13-Feb-19 06:26 AM I got a reply from pfeiffer that they would like to send me the replacement parts kit for free, or would even repair the pump for me at my university free of charge 13-Feb-19 07:12 AM Nice! great to hear pfeiffer decided to actually help out and offered parts and repair for free! 13-Feb-19 07:26 AM Nice! 13-Feb-19 07:26 AM How come they changed their mind? 13-Feb-19 07:53 AM Yeah I'm curious about that as well, that's a pretty big change lol 13-Feb-19 09:13 AM alright, I got that little baby sputter head for 170 shipped, I offered quite a bit more on that incase he thought GOLD THOUGH?! I guess I could have probably gone lower lol 13-Feb-19 09:13 AM I mean I suppose I don't even know if its gold, but its some kind of gold mix I'd think 13-Feb-19 09:16 AM Nice! 13-Feb-19 09:16 AM its just so cute, though it sticks quite far in through a 2.75" conflat, so I'm not sure where I can use it quite yet but I figured it would be handy to have 13-Feb-19 09:16 AM either use it to sputter tiny samples or even a single die or something 13-Feb-19 09:16 AM though I'm not sure how fun it will be to get different targets... 13-Feb-19 09:16 AM and I don't think they really use gold for metal layers in silicon process 13-Feb-19 09:18 AM Can we have high resolution photos all around of that? please? offers cookies 13-Feb-19 09:18 AM I suppose it wouldn't hurt, its just cheaper to use aluminum or something 13-Feb-19 09:18 AM I'll send all the photos I got 13-Feb-19 09:18 AM once I get it I'll get more 13-Feb-19 09:18 AM I assume you want to make one? :P 13-Feb-19 09:19 AM I got mine, thanks, but I got a fixation with miniaturised things. 13-Feb-19 09:19 AM lol ok 13-Feb-19 09:19 AM https://i.ebayimg.com/images/g/QwIAAOSwQpVcYtF1/s-l1600.jpg https://i.ebayimg.com/images/g/0~0AAOSwWbZcYtF8/s-l1600.jpg https://i.ebayimg.com/images/g/djsAAOSwdwlcYtGA/s-l1600.jpg https://i.ebayimg.com/images/g/sIoAAOSwLi1cYtGH/s-l1600.jpg 13-Feb-19 09:19 AM thats what I got 13-Feb-19 09:20 AM I am eager to see how the targets can be changed. 13-Feb-19 09:21 AM yea it might be that whole assembly on top 13-Feb-19 09:21 AM Btw, gold self-diffuses into silicon and it's a nightmare for nowadays processes. 13-Feb-19 09:21 AM https://www.edn.com/electronics-news/4325260/Semiconductor-contamination-Not-your-usual-suspects 13-Feb-19 09:25 AM oh wow 13-Feb-19 09:25 AM good to know :) 13-Feb-19 09:25 AM good read btw haha thank you 13-Feb-19 09:50 AM sploin! 13-Feb-19 10:13 AM @Applied_Ion @Nixie Well the sales person I was writing to mentioned a service technician in her last mail because he is responsible for my University, so for my last mail I clicked the "reply to all" button so he also gets my mail. I wrote them that I'm capable of changing a bearing and used as much technicals terms as possible (basically explaining exactly what I did and why I think the bearing is defective) and this time not the sales person replied, but the technician, stating that he is impressed about my knowledge in vacuum pumps and that he would like to support me by sending me the replacement parts. 13-Feb-19 10:14 AM AWESOME! 13-Feb-19 10:15 AM So same as always, if you know the right people nothing is impossible 13-Feb-19 10:15 AM impossible? :P 13-Feb-19 10:15 AM but yes absolutely 13-Feb-19 10:15 AM That's awesome, great to hear! 13-Feb-19 10:15 AM yayyy turbo pumps for all though 13-Feb-19 10:15 AM gotta love fast spinny things 13-Feb-19 10:15 AM also from what it looked like I can probably get the adapter I need for my turbo from LDS Vacuum for like 500~ bucks if I REALLY need to buy it new 13-Feb-19 10:15 AM which isn't horrid but yea would love to get it cheaper lol 13-Feb-19 10:18 AM Nice 13-Feb-19 10:18 AM What adapter is this? 13-Feb-19 10:18 AM Electrical? 13-Feb-19 10:19 AM no no, the ISO160 to CF 6" 13-Feb-19 10:19 AM because my infinite wisdom decided, lets get an ISO turbo because it was cheap and big and good then conflat all the other things 13-Feb-19 10:19 AM shoulda taken more than two days off for the scope move, I'm so ADD I just can't even focus on work right now lol 13-Feb-19 12:15 PM Just scored some tungsten filaments for my SEM. Still insanely expensive but somehow I feel like I got a good deal. 13-Feb-19 12:15 PM Seller is from Germany., naturlich 13-Feb-19 12:19 PM nice! 13-Feb-19 12:26 PM Gongrats @niklas 13-Feb-19 01:49 PM man gona have fun wet mopping the basement tonight 13-Feb-19 01:49 PM have to try and get as much dirt and dust up off the floor 13-Feb-19 02:00 PM Go, go, go! 13-Feb-19 02:05 PM still at work for another 2 hours atm 14-Feb-19 01:21 AM yawn Good morning! 14-Feb-19 01:21 AM ahh, this feels great, first time I got 10 full hours of sleep in weeks! 14-Feb-19 02:13 AM Don't get used to that. 14-Feb-19 02:14 AM still got a couple years of uni 14-Feb-19 10:40 AM moin! 14-Feb-19 10:54 AM moinmoin ^^ 14-Feb-19 12:17 PM Any USA people here with a recommendation for a source of lab grade ethanol? 14-Feb-19 12:24 PM Liquor store 190 proof ever clear 14-Feb-19 12:24 PM If you can get an industrial/scientific liquor license in Washington you can get 195 and 200 proof synthetic alcohol 14-Feb-19 08:22 PM I have an Adam next to me next 14-Feb-19 10:35 PM Hullo, Adam. 15-Feb-19 12:31 AM moin 15-Feb-19 12:38 AM moinsen! 15-Feb-19 12:55 AM Madam, I'm Adam 15-Feb-19 01:08 AM moin! 15-Feb-19 01:22 AM moin 15-Feb-19 01:34 AM Groin! 15-Feb-19 12:14 PM Neun! 15-Feb-19 02:00 PM Doch! 15-Feb-19 11:48 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1519-2F0ED.jpg 15-Feb-19 11:48 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1517-61A82.jpg 15-Feb-19 11:48 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1518-B2BB9.jpg 15-Feb-19 11:48 PM Stufffff 15-Feb-19 11:56 PM Basement full of toys 15-Feb-19 11:58 PM Previously a trailer full SEM 15-Feb-19 11:58 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190215_171111-2261D.jpg 16-Feb-19 12:03 AM Previously in not LOST. 16-Feb-19 12:23 AM Hehe 16-Feb-19 12:23 AM Also we found out what that "tiny sputter head" is. It's a thin film deposition quartz sensor! Which will be super handy for process checking for sputtering on silicon processes! 16-Feb-19 01:13 AM Moin! 16-Feb-19 02:11 AM moin 16-Feb-19 04:53 AM yeah, I have a few of the crystal balances 16-Feb-19 11:56 AM My favourite phrase from yesterday has to be "cat-induced foreline cleaning adventure" 16-Feb-19 03:48 PM just learned/discovered t-SPL .. will bring it up in the voicechat tomorrow (If I am not at school?) to see if anyone has experience with it, etc 17-Feb-19 01:28 AM moin 17-Feb-19 01:28 AM Moin! 17-Feb-19 01:29 AM moinsen 17-Feb-19 03:26 AM what's a proper black (300nm - 1000nm light absorbing) coating for "UHV" applications? 17-Feb-19 03:28 AM erm 17-Feb-19 03:28 AM pretty much any metal? 17-Feb-19 03:28 AM ah, no, it has to absorb an not reflect 17-Feb-19 03:29 AM yep 17-Feb-19 03:29 AM want to make fluorescence spectroscopy and need to prevent photons from the ionization laser etc finding their way to the detectors 17-Feb-19 03:29 AM in normal atmospheric optics most black matt colour coatings would do the job 17-Feb-19 03:38 AM but it also needs to be vacuum compatible 17-Feb-19 03:39 AM yep 17-Feb-19 03:39 AM maybe there is a cheap solution like aquadaq 17-Feb-19 03:39 AM hum, is aquadaq UHV compatible? 17-Feb-19 03:39 AM but it's to shiny, i guess :/ 17-Feb-19 03:40 AM >>Mit Hilfe von Aquadag erhaltene Beschichtungen werden z. B. in der Vakuumtechnik verwendet, wenn elektrisch leitende, temperaturunempfindliche Beläge mit geringer Neigung zur Sekundärelektronenemission benötigt werden. 17-Feb-19 03:41 AM yeah, it's kinda black 17-Feb-19 03:41 AM >>and now even in english: 'A conductive aquadag coating applied to the inside of the glass envelope of cathode ray tubes, serves as a high-voltage electrode. 17-Feb-19 03:43 AM and i have a bottle %) 17-Feb-19 03:43 AM try using that and some clever geometry 17-Feb-19 03:44 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-48E8E.jpg 17-Feb-19 03:44 AM "store in a cool place" looks at the background Yep, that lab looks pretty cool 17-Feb-19 03:44 AM i store it in a fridge next to the beer 17-Feb-19 03:46 AM Prost! 17-Feb-19 03:47 AM my fear is contamination of the chamber of course 17-Feb-19 03:47 AM it'll all be pumped out eventually 17-Feb-19 03:47 AM but if it works in sealed vacuum tubes it should work well in a constantly pumped chamber 17-Feb-19 03:48 AM hehe yeah i mean wurst kaese is if all the chamber/tubing insides becomes coated with sticky foo 17-Feb-19 03:49 AM What if allowed to freeze? 17-Feb-19 03:49 AM high vacuum compatible wurstbrot! 17-Feb-19 03:50 AM i guess i need a "pre bake" chamber (easy to clean if i fail) with a RGA attached 17-Feb-19 03:50 AM maybe a RGA is overkill, but it would be nice 17-Feb-19 03:51 AM what exactly do you wanna measure? some gaseous excimers? 17-Feb-19 03:52 AM you mean the fluorescence spectrum? 17-Feb-19 03:52 AM only of small amounts of molecules/atoms in general 17-Feb-19 03:53 AM yeah 17-Feb-19 03:53 AM do you habe anythinf particular in mind? 17-Feb-19 03:53 AM playing with atomic physics 17-Feb-19 03:54 AM //is interested// 17-Feb-19 05:00 AM well, multiwalled carbonnanotubes would also work, they got cheaper, but hm, depends on how big your chamber is xD 17-Feb-19 05:00 AM otherwise soot from some high carbon stuff like naphthalin would be pretty black, but not sure how many volatile compounds would abe into the soot 17-Feb-19 05:00 AM but I didn't fully get your intent tbh 17-Feb-19 05:09 AM okay, in optics under normal atmosphere you paint shiny surfaces/edges with black paint to prevent stray light problems 17-Feb-19 05:09 AM my question is, what's a recommended UHV compatible coating for this job 17-Feb-19 05:09 AM maybe aquadaq it is 17-Feb-19 05:09 AM or highend stuff like https://www.acktar.com/about-us/press-releases/ultra-black-coatings-ultra-high-vacuum/ 17-Feb-19 05:09 AM i guess that stuff is pricey 17-Feb-19 05:18 AM ah sorry, I meant what exactly you want to do with the fluorescence spectrometry 17-Feb-19 05:18 AM you can give burning naphthaline a try, the soot is extremly black, but I would think it will have outgas problems from the uncompleted combustion 17-Feb-19 05:18 AM hmm, maybe you can also try acetylene 17-Feb-19 05:18 AM maybe you have some and I would propose less outgas 17-Feb-19 05:32 AM yeah hmm 17-Feb-19 11:33 AM Joined the server. 17-Feb-19 08:31 PM https://twitter.com/nanographs/status/1097351325078020096 17-Feb-19 08:31 PM Im steaming fixing Connors new SEM 17-Feb-19 10:30 PM Yay! 17-Feb-19 10:51 PM You both look funny. 17-Feb-19 10:51 PM I just wondered, if sufficiently shielded, can you run a sem in the ISS by just opening a port to space? 17-Feb-19 10:51 PM Also, morning! \o/ 17-Feb-19 11:08 PM How useful is a variac around the lab, and, what size should I spec out? 20A? 17-Feb-19 11:23 PM I use one for my sputtering rig. Its 3000VA, slightly overkill 17-Feb-19 11:26 PM pizza 17-Feb-19 11:26 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20190218_082616-0EC82.JPG 17-Feb-19 11:26 PM Slightly less chinese than that. 17-Feb-19 11:26 PM hehe 17-Feb-19 11:26 PM the 3000VA ones isn't all too much more than the 2000VA one.. but I dont have a wall socket that can deliver that much as of right now 17-Feb-19 11:26 PM same one, just in red, for $140 USD, https://www.amazon.com/Max-Amp-Variac-Variable-Transformer/dp/B07MJHJR95/ 18-Feb-19 12:13 AM Joined the server. 18-Feb-19 01:14 AM moin 18-Feb-19 01:22 AM Moin! 18-Feb-19 08:57 AM moin! 18-Feb-19 08:57 AM any comments on Variacs? 18-Feb-19 09:33 AM a variac is extremly usefull 18-Feb-19 09:33 AM and honestly, get the biggest one you can get 18-Feb-19 09:33 AM I don't know what american houses get in terms of power, but here you get 230V, usually with a 16 amp fuse, so most people get a 10 or 20 A one 18-Feb-19 10:20 AM yeah, currently looking at a 20A/2000VA 18-Feb-19 10:20 AM the motor I want to control is rated at 1250W 18-Feb-19 10:23 AM they should not be too expensive, maybe go for a used one 18-Feb-19 10:23 AM as they are either perfectly working (maybe clean the wiper, but that's it) or totally fried 18-Feb-19 10:24 AM I checked on ebay, and brand new ones are on-par price-wise with the used ones 18-Feb-19 10:24 AM oh, lol 18-Feb-19 10:25 AM ebay had better prices for brand new, over amazon, but the shipping was unclear, whereas w/ amazon I could get it by wednesday 18-Feb-19 10:25 AM there is a place in town with some for double the price.. but I dont want to go across the lake to go get it 18-Feb-19 10:25 AM do you need it quickly? 18-Feb-19 10:26 AM need vs want 18-Feb-19 10:26 AM also, I could likely get similar response with a triac based controller, considering that was the original speed controller 18-Feb-19 10:26 AM but, the variac could find uses elsewhere, and I dont have one yet 18-Feb-19 10:26 AM the project will the router motor will eventually come to an end 18-Feb-19 10:26 AM but it will eventually need another speed controller, likely one I build myself 18-Feb-19 10:26 AM since it does have some magnets on the rotor for tachometer/closed loop 18-Feb-19 10:28 AM glue a stepper to your variac and write some code for feedback 18-Feb-19 10:29 AM I have a 500 pulse optical encoder from my steppers that I had on the rig before, but now with the adapters it doesnt really fit.. but, there is that hall effect feedback 18-Feb-19 10:29 AM also, steppers arent designed to go fast 18-Feb-19 10:29 AM not the ones I have 18-Feb-19 10:29 AM ie, I need 600-6000 rpm 18-Feb-19 10:29 AM and 600rpm is pushing what my steppers can do, under no load 18-Feb-19 10:30 AM wait, a stepper as router motor? 18-Feb-19 10:31 AM it is a universal motor 18-Feb-19 10:31 AM I attempted steppers before 18-Feb-19 10:31 AM on the same stup 18-Feb-19 10:31 AM I used a hand drill for mos tof my testing to date 18-Feb-19 10:31 AM but I just installed the router over the weekend 18-Feb-19 10:31 AM and have it hooked up to a 12v DC PSU, and getting 600rpm 18-Feb-19 10:31 AM but I need it to go faster, and my variable DC PSU cant give enough amps 18-Feb-19 10:31 AM so, my options are to get a bigger amperage variable DC PSU, a triac based controller, or a variac 18-Feb-19 10:31 AM and I want something "now" so I am not going to build a clsoed loop variac cotroller for it just yet, mainly ebcause load will not change.. so I can look at the speed on the scope and adjust power input, however needed 18-Feb-19 10:34 AM yep, sounds like a variac is the way to go 18-Feb-19 10:35 AM okay, and 2000VA seems a decent size unless I feel 3000VA is better for whichever purpose in the future 18-Feb-19 10:35 AM thanks for the input 18-Feb-19 10:36 AM so... 2500W? 18-Feb-19 10:36 AM if only... 18-Feb-19 10:36 AM * goes to hardware store looking for a 15.555 bolt, comes back with a 16mm and a 15mm * 18-Feb-19 10:38 AM just get a 15 bolt and glue a small timer IC to it 18-Feb-19 10:38 AM that'll fix it 18-Feb-19 10:38 AM is there any way to make a variac more... sensitive? it's not a pot that you are moving but physically moving brushes, right? mechanically 18-Feb-19 10:39 AM you can gear it down 18-Feb-19 10:39 AM but it basically looks like a huge potentiometer 18-Feb-19 10:41 AM but not like I can add resistors in series to trick the potentiometer into a certain range 18-Feb-19 10:41 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190218_194042-63161.jpg 18-Feb-19 10:41 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190218_194051-9E500.jpg 18-Feb-19 10:41 AM you can, it just would not be very efficient 18-Feb-19 10:41 AM the variac works inductively, just like a transformer 18-Feb-19 10:42 AM thanks for those pics, explains it a bit more than some GIF that a 13 year old made explaining how they work 18-Feb-19 10:46 AM oh, wow, found a 3000VA one on ebay, with shipping within the week, for the price of a 2000VA via amazon.. will go with this 18-Feb-19 10:47 AM nice! 18-Feb-19 10:47 AM also.. jus tput in an offer for the jig borer, and about to buy that watchmaker's lathe.. the hardinge hlv-h sold over the weekend though... btu they have like 3 more.. a little bit more expensive, but also better condition.. 18-Feb-19 10:48 AM quite the shopping week 18-Feb-19 10:48 AM and I still need to pay for that tree removal, I have the invoice next to me 18-Feb-19 10:48 AM and I need to file my taxes 18-Feb-19 10:48 AM and in one week is our first certification exam... 18-Feb-19 10:48 AM fun! 18-Feb-19 10:49 AM ...and my eye is twitching... 18-Feb-19 10:49 AM offers you some coffee 18-Feb-19 10:49 AM yeah, I just had an espresso, thanks anyways 18-Feb-19 10:49 AM "an" espresso can range from 20 ml to 1 L 18-Feb-19 10:50 AM 30ml in this case 18-Feb-19 10:50 AM err 18-Feb-19 10:50 AM 60ml 18-Feb-19 10:50 AM 1/4 cup 18-Feb-19 10:50 AM I actually put it in a specific, coloured, ceramic, measuring cup 18-Feb-19 10:50 AM our uni's got an offer, 250 ml espresso for 4€ 18-Feb-19 10:50 AM pfffff 18-Feb-19 10:50 AM how many "shots" in there? 18-Feb-19 10:50 AM my 60ml is a double shot 18-Feb-19 10:51 AM no Idea 18-Feb-19 10:51 AM but it wakes you up 18-Feb-19 10:53 AM https://photos.app.goo.gl/TWBDGrcXg6CcGSAG6 18-Feb-19 10:53 AM what the hell discord 18-Feb-19 10:53 AM chopped sooo abd 18-Feb-19 10:53 AM open original 18-Feb-19 10:53 AM uhh, a real coffee machine 18-Feb-19 10:54 AM a green 1/4 cup measuring cup is my glass 18-Feb-19 10:54 AM it's an epsresso machine 18-Feb-19 10:54 AM and I kinda half hacked it 18-Feb-19 10:54 AM repalced the SCR with a double transsitor + mosfet 18-Feb-19 10:54 AM .. mainly because the scr was broken! 18-Feb-19 10:54 AM also made it "naked"/bottomless by drilling out the bottom of the portafilter 18-Feb-19 10:54 AM and maybe a few other little hacks 18-Feb-19 10:54 AM but yeah 18-Feb-19 10:55 AM nice 18-Feb-19 10:55 AM ...now I want coffee >.< 18-Feb-19 10:56 AM I used to drink like 2 or 3 double shots a day 18-Feb-19 10:56 AM now just one 18-Feb-19 10:56 AM we had a free espresso machine at work 18-Feb-19 10:56 AM used to be hopped on that all the time 18-Feb-19 10:56 AM also soda-pop was free, too 18-Feb-19 10:57 AM oh my 18-Feb-19 10:57 AM best investment of getting work done 18-Feb-19 10:57 AM yep 18-Feb-19 10:57 AM until everyone dies of a heart attack xD 18-Feb-19 10:57 AM or diebetes 18-Feb-19 10:57 AM diabetes? 18-Feb-19 10:57 AM I tried to stay away from the soda 18-Feb-19 10:57 AM but when the coffee beans were out for the week, they were out.. 18-Feb-19 10:58 AM https://giphy.com/gifs/diabeetus-RbaUECDJktXUc 18-Feb-19 11:01 AM no coffee for a week 18-Feb-19 11:01 AM that's my biggest fear 18-Feb-19 11:03 AM talkative in here this morning 18-Feb-19 11:03 AM I saw mentions of variacs 18-Feb-19 11:03 AM Yes, I just purchased a 3000VA one via ebay 18-Feb-19 11:03 AM for controlling a universal motor from a hitachi router 18-Feb-19 11:03 AM to drive my biodiesel flow bench 18-Feb-19 11:03 AM y'all were too busy fixing that SEM to do a real voice chat to learn about this 18-Feb-19 11:03 AM was anything fixed in the end? 18-Feb-19 11:05 AM https://i.imgur.com/tn6FHEZ.jpg 18-Feb-19 11:05 AM this is what ya need 18-Feb-19 11:05 AM okay, sure 18-Feb-19 11:05 AM hehe 18-Feb-19 11:05 AM send it to me via USPS priority mail, if it fits 18-Feb-19 11:05 AM what is that rated at? 18-Feb-19 11:05 AM can't remember, I have to go downstairs and check, it can take 120 in and boost it to 240 though 18-Feb-19 11:05 AM :) 18-Feb-19 11:06 AM neat neat 18-Feb-19 11:06 AM and I think those are 30A plugs on it 18-Feb-19 11:06 AM huh actually I'm not sure the sticker says 18-Feb-19 11:09 AM I highly doubt this chinese 3000VA can do the full 30A.. but it should be more capable of doing 20A than the 20A one 18-Feb-19 11:09 AM https://i.imgur.com/IfqS51S.jpg 18-Feb-19 11:09 AM and sorry, it can boost 120 to 280V 18-Feb-19 11:10 AM dang 18-Feb-19 11:10 AM what do you use it for, if anything 18-Feb-19 11:10 AM nothing yet... but I had planned for using it for bringing up really old computers with linear supplies... 18-Feb-19 11:10 AM its not ussually the best idea to just give the old massive caps full voltage right off the bat... 18-Feb-19 11:10 AM but since they are linear supplies, you can safely just slowly creep them up with them disconnected 18-Feb-19 11:11 AM BANG 18-Feb-19 11:11 AM yeaaa... 18-Feb-19 11:11 AM I don't think that will happen but it could 18-Feb-19 11:14 AM So you got one like mine, then? 18-Feb-19 11:14 AM yup, price was right 18-Feb-19 11:14 AM and shipping within a week is acceptable.. I still need to figure out some solenoid valves.. 18-Feb-19 11:15 AM Can pricing be known? 18-Feb-19 11:15 AM I think mine costed 150€ 18-Feb-19 11:15 AM or whereabouts. 18-Feb-19 11:16 AM ~$100 USD tax+shipped 18-Feb-19 11:16 AM thats niiiiice 18-Feb-19 11:16 AM US.. https://www.ebay.com/itm/110V-Auto-3000w-30Amp-Variac-Variable-Transformer-AC-Voltage-Regulator/183558390352 18-Feb-19 11:16 AM as chinese as you can get 18-Feb-19 11:16 AM but hey.. $100 18-Feb-19 11:18 AM Correction 92.82$ + shiping, so about 100€ 18-Feb-19 11:18 AM (year and a half ago) 18-Feb-19 11:19 AM okay, yeah, not too far off 18-Feb-19 11:20 AM but yea, SEM progress so far for those wondering: 30A circuit run from breaker panel over water chilling lines ran, quick disconnects at chiller side for easy drain/fill/flush operations lines flushed with Calcium Lime Rust remover twice now, the second time last night did wonders, we now see the flow rate we would expect, that is still currently in the lines we are thinking of bringing up the machine with it in to let it warm up a bit since its only gotten to about 15 degrees C so far, then after the CLR has run like that for a bit, flush, do the H2O2 flush, then flush with distilled, then final fill Started re-cabling the console/column, about, 1/3rd the way there with that. Column is up on its feet. We bodged a blanking plate for the Kevex EDS system which is out of commission at the moment. So that should be good now. Roughing pump we have to re-wire to a standard outlet, has a twist lock that goes into the system, once that is done we can do the LDS flushing fluid and oil refill. All console boards have had their connectors cleaned, board and console side, all chips ensured they are seated well, and re-plugged. 18-Feb-19 11:20 AM I wanted it in red, but it was more expensive, so I got stuck with the beige one. 18-Feb-19 11:20 AM Thats all been 2 days of work so far... We have another 3 ahead of us... 18-Feb-19 11:20 AM hoping everyone is crossing their fingers for SEM images by Wednesday :) 18-Feb-19 11:20 AM So far Adam and I are quite happy with how things are looking though 18-Feb-19 11:21 AM We are crossing things that are not fingers to see your SEM running, don't worry. 18-Feb-19 11:21 AM hehe 18-Feb-19 11:22 AM tries to hide envy, fails 18-Feb-19 11:22 AM When did you say I could visit? 18-Feb-19 11:22 AM XDDDDDDDDDDDDDD 18-Feb-19 11:22 AM So there was a missing module for the eds? 18-Feb-19 11:22 AM Or was it destroyed or something 18-Feb-19 11:27 AM so the EDS was removed from the column when it was brought over to the storage building it was in 18-Feb-19 11:27 AM and well it was duct taped to the side of the column and it stuck out the furthest... 18-Feb-19 11:27 AM and the tip of the EDS head has Beryllium on it... 18-Feb-19 11:27 AM and that little window of Beryllium was shattered inward... 18-Feb-19 11:27 AM @Treehouseman 18-Feb-19 11:29 AM WOAH 18-Feb-19 11:29 AM so, what now? 18-Feb-19 11:29 AM yeaa... don't want to snort that stuff kids 18-Feb-19 11:29 AM @GigaSquirrel might want to. 18-Feb-19 11:29 AM He's weird. 18-Feb-19 11:30 AM my EDS system is currently dead... its possible to get a new window for it... or make something work with it... so long as the sensor in the back of the thing isn't shot... 18-Feb-19 11:30 AM and so long as we can pump the EDS gun back down 18-Feb-19 11:30 AM because that Beryllium keeps a vacuum inside the EDS gun 18-Feb-19 11:30 AM it even has a tiny little ION pump on it to keep its internal vacuum 18-Feb-19 11:30 AM rubs white powder off his nose Sorry, wasn't listening, what? 18-Feb-19 11:30 AM heh 18-Feb-19 11:30 AM shoulda seen Adam yesterday, he was practically snorting pixie sticks 18-Feb-19 11:31 AM Be Windows pose close to no danger, since they don't produce dust 18-Feb-19 11:31 AM Really? it was pretty shattered... I'm sure there was some small particulate 18-Feb-19 11:31 AM Except when are crushed into something 18-Feb-19 11:32 AM Wth happened to it O.o 18-Feb-19 11:32 AM all the ones I've seen so far just burst like Al foil 18-Feb-19 11:33 AM It got smashed into something 18-Feb-19 11:33 AM yeah, but... ouch. 18-Feb-19 11:34 AM yea... its not pretty 18-Feb-19 11:34 AM I really hope the EDS sensor is OK... 18-Feb-19 11:34 AM I kinda doubt it 18-Feb-19 11:34 AM but I can hope 18-Feb-19 11:34 AM it would be a real shame to have to write off a dry EDS system 18-Feb-19 11:36 AM Yeah. I bet we can figure something out though 18-Feb-19 11:36 AM like i don't care that I payed for it at this point, I just think it would suck considering how far and few between they seem to be, since well everyone wants them 18-Feb-19 11:36 AM yea hopefully its not like someone crammed a screwdriver down the thing 18-Feb-19 11:36 AM at-least as far as we know 18-Feb-19 11:36 AM oh also, you should see if one of your friends has the door latch for this thing on one of their scrap machines they would be happy to part with... 18-Feb-19 11:36 AM I'm still really confused who removed that and why 18-Feb-19 11:40 AM just cleared off my surface plate withe rsome ether, and finally put some cloth over it to protect it 18-Feb-19 11:40 AM not a real cover, but better than nothing 18-Feb-19 11:41 AM You should just buy a cnc machine next and make your own latch! 18-Feb-19 11:44 AM @AdamMcCombs's talk just hit the HaD YouTube channel https://youtu.be/Mam2kt0Dcvg 18-Feb-19 11:44 AM I bet he has access to a CNC somewhere. 18-Feb-19 11:44 AM nice 18-Feb-19 11:44 AM so conmega is the one with the pony tail.. okay 18-Feb-19 11:44 AM I used to have long hair myself, now I shave entire head, every day 18-Feb-19 11:46 AM You see the guy who is moving his head a lot in Adams talk? thats me. XDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD 18-Feb-19 11:46 AM Your internet famous now! 18-Feb-19 11:50 AM Yeah, right. As the guy who sat 7h in the first day at supercon because he wasn't able to talk to anyone. 18-Feb-19 11:50 AM (and I meant it as I didn't expect to see myself there) I thought they cropped the image a bit more. 18-Feb-19 11:55 AM Nice talk @AdamMcCombs not that I haven't heard a million things from you in the last 3 days anyway, but that was clear, concise, well times, and well compacted for 10 minutes :) 18-Feb-19 11:55 AM better than a conversation going from "simple SEM bringup" to like TEM holy shit in 20 minutes lol 18-Feb-19 11:56 AM Yeah the 10 min part was fun... 18-Feb-19 11:56 AM (somewhat OT, but on the topic of great talks: https://www.youtube.com/watch?v=38mTnnR4dSI ) 18-Feb-19 11:57 AM vintage computers lol 18-Feb-19 11:57 AM I remember when some nuclear reactor people came to our vintage computer forums asking to hire some people who knew about PDP 11 systems and managing them since they got approved to run there until like 2025 or something 18-Feb-19 11:59 AM XDDD 18-Feb-19 11:59 AM yep, that's nuclear security for you 18-Feb-19 11:59 AM if it dosen't use 5.12" floppies it's too new 18-Feb-19 12:02 PM 5.25"? pft, you mean 8"? 18-Feb-19 12:02 PM nuclear missles are still controlled with 8" disks and IBM Series/1 minicomputers 18-Feb-19 12:02 PM I downloaded the doc the government released saying those were going to be run until 2020 I think it was lol 18-Feb-19 12:05 PM yeah missles are a different story 18-Feb-19 12:05 PM compared to that reactor safety is nothing more than a sign saying "Please do not enter" 18-Feb-19 12:06 PM lol 18-Feb-19 12:07 PM well, that's at least in theory 18-Feb-19 12:07 PM good thing there are absolutely no stories of anything going wrong with any of this 18-Feb-19 12:12 PM never 18-Feb-19 12:21 PM I'm actually hoping for some more fun stories once I've started working 18-Feb-19 12:21 PM hoping to hear them, not to cause them 18-Feb-19 01:47 PM Festo solenoid valves are good, yeah? 18-Feb-19 01:47 PM Aye 18-Feb-19 01:48 PM I was trying to come up with some inappropriate word for 'good' but decided against it 18-Feb-19 01:49 PM watch out or the admins might hear you 18-Feb-19 01:49 PM as I said, I chose against it 18-Feb-19 01:49 PM plenty of 3-way (which I either need that or two single valve) festo valves on the fleabay 18-Feb-19 01:49 PM Is there any other brand I should look at? 18-Feb-19 01:53 PM is the valve critical in any way? 18-Feb-19 01:53 PM if not get the cheapest one you trust 18-Feb-19 01:53 PM if it is critical festo, burkert etc are the way to go 18-Feb-19 01:56 PM I am just measuring the amount of fuel ouput from the pump for 60s, and want to divert the running pump to start colelcting into a beaker/similar with a valve 18-Feb-19 01:56 PM low pressure as it will be venting to atm 18-Feb-19 01:59 PM in that case I would not cheap out, fuel can do some pretty nasty stuff to cheap stuff 18-Feb-19 01:59 PM especially biodiesel 18-Feb-19 01:59 PM it wont be in use for much time though.. could likely get most of the testing done in a single day 18-Feb-19 02:00 PM hmm 18-Feb-19 02:00 PM you're in the USA, right? 18-Feb-19 02:00 PM Yes 18-Feb-19 02:01 PM hm 18-Feb-19 02:01 PM "that changes everything" 18-Feb-19 02:01 PM If you're willing to pay for shipping I can send you some burkert valves 18-Feb-19 02:01 PM hah, I woudl like to have the valves on hand when the variac is delviered in a week 18-Feb-19 02:02 PM no way with our postage system 18-Feb-19 02:02 PM right, who knows when my watchmaker's lathe will get here 18-Feb-19 02:02 PM where's that coming from? 18-Feb-19 02:02 PM "Germany" 18-Feb-19 02:02 PM wait, no, The Netherlands 18-Feb-19 02:02 PM Delft? 18-Feb-19 02:04 PM yep, netherlands 18-Feb-19 02:04 PM so many of these valves are for psneumatics.. would that also work for fluids? 18-Feb-19 02:04 PM I would assume more leakage w/ air than a viscous liquid 18-Feb-19 02:04 PM gasses are just compressible, less dense fluids 18-Feb-19 02:05 PM that statement was almost on par with "hydrogen atoms are just glorified protons" 18-Feb-19 02:05 PM ...aren't they? 18-Feb-19 02:05 PM they are 18-Feb-19 02:05 PM but the point being.. 18-Feb-19 02:05 PM your response in way way helped me make a conclusion 18-Feb-19 02:06 PM which would be? 18-Feb-19 02:06 PM "Yes, they also work with fluids" 18-Feb-19 02:06 PM Yes 18-Feb-19 02:07 PM lots of these Festo valves have a 'pilot' port.. so they would need some back pressure? 18-Feb-19 02:07 PM I think so, yes 18-Feb-19 02:14 PM may pick up two normally closed valves on amazon, wire two SSR and a PNP for revsersing one.. that way I get two valves in the end.. 18-Feb-19 02:14 PM so, yeah, I called out the guy with the watchmaker lathe for trying to charge me to use paypal.. I linked him to the PP user agreement stating that you arent allowed to surchage for such a thing 18-Feb-19 02:14 PM he came back with a US based bank number for to wire, lol 18-Feb-19 02:17 PM that would be an instant no-go for me 18-Feb-19 02:17 PM he gave me a different netheland based bank initially 18-Feb-19 02:17 PM and he is well established and known for selling quality stuffs 18-Feb-19 02:17 PM but yeah, I think people jsut dont know 18-Feb-19 02:17 PM that you arent allowed to surcharge 18-Feb-19 02:17 PM unless you always add that amount no matter what payment service is chosen 18-Feb-19 02:17 PM but it was specifically raised base dont he take PP takes 18-Feb-19 02:17 PM lol 18-Feb-19 02:17 PM I basically stated that it discourages customers from using that service 18-Feb-19 02:17 PM I get it, but yeah 18-Feb-19 02:17 PM I called him out on it 18-Feb-19 02:19 PM was that on ebay or some other site? 18-Feb-19 02:19 PM anywho, I did wire him to the US account (Transferwise) 18-Feb-19 02:19 PM he has his own site 18-Feb-19 02:20 PM ah, ok 18-Feb-19 02:20 PM because ebay can be weird in that regard, too 18-Feb-19 02:20 PM I liek PP because they offer buyer protexction 18-Feb-19 02:20 PM and well, I used to work for them for 5 years before quitting and goign to watchmaking school 18-Feb-19 02:21 PM with those 10 hornets, I just contacted the seller, basically "Make me a good offer and give me your pp address", but after we agreed on a price he told me to make an offer through ebay 18-Feb-19 02:21 PM yeah, you need to 18-Feb-19 02:21 PM it's against their ToS 18-Feb-19 02:21 PM and there is also buyer protection 18-Feb-19 02:22 PM next day I got an email from ebay "Thank you for being a faithfull customer, we know you wanted to pay someone directly but decided not to" 18-Feb-19 02:22 PM an additional layer 18-Feb-19 02:22 PM hsahaha 18-Feb-19 02:22 PM yeah dude, you cant talk about that stuff through ebay 18-Feb-19 02:23 PM didn't know they scanned messages for stuff like that 18-Feb-19 02:23 PM what else would they look for? 18-Feb-19 02:23 PM let me rephrase 18-Feb-19 02:23 PM I didn't know they scanned messages at all 18-Feb-19 02:23 PM I was a sysadmin for the backend of t he search engine for ebay before paypal split off and I jumped ship.. but I dont know half of what they scanned for 18-Feb-19 02:23 PM heh, why not? 18-Feb-19 02:23 PM one of our admins read off some emaisl of webmaster@ebay.com of people being annoyed and whatnot with 'spam' etc.. as if you cant turn off every setting of emails 18-Feb-19 02:23 PM some of them were funny 18-Feb-19 02:23 PM he read them off during a friday happy hour 18-Feb-19 02:25 PM so, looks like $30 USD or so for a stainless teel solenoid valve, 12v.. and like $5 for some 1/4" NPT Male to 3/8" barb for the tubing 18-Feb-19 02:25 PM $30 for a simple valve seems a lil expensive, meh 18-Feb-19 02:25 PM only thing I ever complained about to ebay is them censoring searches depending on your country and that goddamn autotranslate thing 18-Feb-19 02:25 PM try and get some used valves maybe 18-Feb-19 02:26 PM I dont think 1/4" is too small, neither, but I may look for a bigger version 18-Feb-19 02:26 PM my (Viton) tubing is 3/8" ID 18-Feb-19 02:27 PM what kind of flow rate are we talking about? 18-Feb-19 02:27 PM sorry for inches 18-Feb-19 02:27 PM let's see, theoratical max is something like... 18-Feb-19 02:27 PM 1cc/rev ... 6k RPM.. so 6L/min max 18-Feb-19 02:28 PM pipes here are in inches, too... :/ 18-Feb-19 02:28 PM oh? 18-Feb-19 02:29 PM yeah, all of that plumbing stuff is NPT / BSP 18-Feb-19 02:29 PM I dont like BSP too much 18-Feb-19 02:30 PM for most of the stuff you don't have a choice 18-Feb-19 02:31 PM industry standards.. 18-Feb-19 02:32 PM yep... 18-Feb-19 02:32 PM does ebay.com also autotranslate offers from different countries? 18-Feb-19 02:37 PM no? 18-Feb-19 02:37 PM ? = I dont htink so 18-Feb-19 02:37 PM hrmpf 18-Feb-19 02:37 PM some items are not available outside the country of origin 18-Feb-19 02:37 PM because ebay.de does so 18-Feb-19 02:37 PM I tracked stuff down on the australian site and messaged the seler to ask for international shipping, and he did 18-Feb-19 02:38 PM and it translates "pound" to "kg" and "inches" to "cm" 18-Feb-19 02:38 PM like it does not calculate the value, it just replaces the words 18-Feb-19 02:38 PM and it translates "LASL" to the german word for "farmer" 18-Feb-19 02:38 PM and I just can't understand why 18-Feb-19 02:38 PM also that can't be turned off 18-Feb-19 02:39 PM oh, I guess I have a 1/4" NPT die.. so I could just machine the barbed fittings myself.. hrmm 18-Feb-19 02:39 PM on your new lathe! 18-Feb-19 02:39 PM hah, that wont arrive for a while 18-Feb-19 02:39 PM I'll do it on the Wabeco 18-Feb-19 02:39 PM also, we dont stock stainless at school 18-Feb-19 02:39 PM so I will need a bar 18-Feb-19 02:39 PM most watchmakers lathes cant accept more than 8mm 18-Feb-19 02:41 PM oh, ok 18-Feb-19 02:41 PM some only 6mm 18-Feb-19 02:41 PM you can get a 3 jaw or 6 jaw chuck for them, but the arbmor moutn into the spindle is only 8mm 18-Feb-19 02:41 PM arbor mount 18-Feb-19 02:42 PM and I thought the 18mm of my lathe were small 18-Feb-19 02:43 PM the wabeco normally ha the 3 jaw on, but we also have a set of metric 5C collets 18-Feb-19 02:43 PM so, a max of what, like 30mm in them? 18-Feb-19 02:43 PM but bigger in the 3 jaw 18-Feb-19 02:45 PM uh, nice 18-Feb-19 02:45 PM something that big would make a lot of things easier 18-Feb-19 02:46 PM also, jsut looked up, max flow rate of a 3/8" copper pipe is ~2gpm, or ~7.5L, so I should be plenty good in that regard 18-Feb-19 02:46 PM if my max expected (a whole lot less, acctually) of 6L/min is within spec 18-Feb-19 02:46 PM yeah, need the valves, buying two 18-Feb-19 02:49 PM and even more shopping yay 18-Feb-19 02:49 PM if you can't pay the tree guys will they put the wood back onto your roof? 18-Feb-19 02:50 PM I am sure it goes to "collections" 18-Feb-19 02:50 PM and gets marked on your credit report 18-Feb-19 02:50 PM so, a foot of 1/2" 316 stainles sis only $6.64 .. nice 18-Feb-19 02:50 PM and like $5 for shipping, right? 18-Feb-19 02:50 PM I may be able to piggy-back onto a school order, will ask tomorrow 18-Feb-19 02:52 PM heh, nice 18-Feb-19 02:54 PM I coudl also make them out of brass.. we have stock.. but the deal with that is that brass can accelerate some oxidation w/ biodiesel 18-Feb-19 02:54 PM doubt much of anythign for a while, especially small valves/whatnot 18-Feb-19 02:54 PM could also pickup premade barbs at the hardware store right now.. but why not make them? 18-Feb-19 02:54 PM well, time, that is one reason... 18-Feb-19 02:57 PM making them gives you experience! 18-Feb-19 02:57 PM ^^ 18-Feb-19 02:57 PM experience with what? 18-Feb-19 02:57 PM like, its nothing new 18-Feb-19 02:58 PM yeah, but even repeating known things can help you make it better 18-Feb-19 02:58 PM just the hours on the lathe 18-Feb-19 02:58 PM or minutes, depending 18-Feb-19 02:58 PM turn outside of thrread, cut threads, drill hole, turn outside barb, part off 18-Feb-19 02:58 PM rinse repeat 18-Feb-19 02:58 PM but yeah, I do need to learn some optimizations 18-Feb-19 02:58 PM our parting off tool sucks ass, I need to figure it out 18-Feb-19 02:58 PM it keeps "walking" 18-Feb-19 02:58 PM out of allignment 18-Feb-19 02:59 PM urgh 18-Feb-19 03:00 PM for the adapter I made yesterday I took the bar out and stuck it ina vise and took a saw to it 18-Feb-19 03:00 PM after it walked a bit on me 18-Feb-19 03:00 PM I think the quick change post can only get so tight 18-Feb-19 03:01 PM time to get out the welder 18-Feb-19 03:01 PM the only "welder" at school is for attaching "feet" onto the backside of a dial 18-Feb-19 03:02 PM oh 18-Feb-19 03:02 PM well 18-Feb-19 03:02 PM that might take a while 18-Feb-19 03:02 PM maybe just maybe 18-Feb-19 03:02 PM but htink of all the experience! 18-Feb-19 03:02 PM Yeah! 18-Feb-19 03:02 PM I'm just imagening someone wirebonding that thing until it no longer moves 18-Feb-19 03:04 PM oh, doh, I might have forgotton about making/buying a union valve 18-Feb-19 03:04 PM not valve 18-Feb-19 03:04 PM but, a "T" thing 18-Feb-19 03:04 PM one input two outputs 18-Feb-19 03:04 PM which go into the solenoid valves 18-Feb-19 03:05 PM just a three way cross? 18-Feb-19 03:05 PM simple to do, but no need to make it NPT 18-Feb-19 03:05 PM yes 18-Feb-19 03:05 PM requires a plug tap, basically 18-Feb-19 03:05 PM or a welder 18-Feb-19 03:06 PM k, time to watch tv as I half study for this first cert exam in one week 18-Feb-19 03:07 PM good luck with that 18-Feb-19 03:07 PM I'm gonna go to bed now 18-Feb-19 03:07 PM good night 18-Feb-19 03:07 PM or... whatever time it is at your place 18-Feb-19 03:08 PM 3pm 18-Feb-19 11:43 PM Borning! \o/ 19-Feb-19 12:42 AM moin 19-Feb-19 12:42 AM have an ISI DS 130 and an ISI SS 60 many parts in common? 19-Feb-19 12:42 AM @AdamMcCombs could know 19-Feb-19 12:42 AM or @Conmega 19-Feb-19 12:42 AM since he's the one who bought a DS 130 currently, right? 19-Feb-19 01:00 AM Moin! 19-Feb-19 01:22 AM (i bought a DS 130 recently :3) 19-Feb-19 01:22 AM it has two sample stages, one is for STEM, what would be very nice, i guess 19-Feb-19 01:22 AM i know, you could upgrade every SEM to a STEM with a proper reflector rig 19-Feb-19 09:01 AM Hey @N00N, Adam knows someone with some ISI DS-130 parts 19-Feb-19 09:01 AM I also have dual sample stages, no STEM detector, though Adam thinks he might have one for me... So I'd be curious if you could note down how yours is hooked up. I think it connects right to the console but Adam thinks there may be some external control box. 19-Feb-19 09:03 AM okay, i will make pictures, scheduled pickup is March 22 19-Feb-19 09:04 AM Awesome, talk to Adam about moving one of these properly... We took 5:30 hours just to get mine loaded up working together pretty much as fast as possible. 19-Feb-19 09:04 AM You might have an easier time since if your not working with a short trailer like me... you might not need to take off the top of the column and everything. 19-Feb-19 09:05 AM well ... i'm from germany 19-Feb-19 09:05 AM I know, I mean't just for knowledge in general 19-Feb-19 09:05 AM you can probably move it yourself, just he can tell you want to remove for safe transit and how to package them 19-Feb-19 09:05 AM ah ok, yeah, i'll do 19-Feb-19 09:05 AM but i have already moved an ISI SS-60 19-Feb-19 09:05 AM (without damaging it) 19-Feb-19 09:06 AM oh nice ok, didn't know your experience 19-Feb-19 09:06 AM well good luck then! 19-Feb-19 09:06 AM These are cool machines 19-Feb-19 09:06 AM yep 19-Feb-19 09:06 AM and oh btw, the column is on metal tripod configuration of casters 19-Feb-19 09:06 AM so the column isn't too bad, and for default config weight, which yours doesn't sound like base default config, its like 900~? LBS 19-Feb-19 09:06 AM so its not actually that heavy either 19-Feb-19 09:06 AM So hopefully you'll have an easier time 19-Feb-19 09:06 AM I had a height restriction for mine of 5 feet max... Small trailer I have to move it heh... 19-Feb-19 09:06 AM so we had to take off a lot of the column 19-Feb-19 09:09 AM it's located at ground level, so it should be no mega effort to move it in my trailer 19-Feb-19 09:09 AM according to your pictures i have a similar truck-trailer pair 19-Feb-19 09:31 AM Well measure the height of the opening of your trailer, if its like 6ft and you don't have an IGP then you should be fine. If its less than 6ft or you have an IGP... you'll probably have to disassemble part of the column. Also the place I got my DS-130 had a forklift on site... So loading we just got it in the trailer... At home we made ramps with some car ramps and some 3/4" plywood... but the front caster on the column punched through the 3/4" plywood a few times in places were the ramps didn't cover... and towards the end of the ramp one of our strap points pulled out of the wall... Like Adam says this was the sketchiest move he's ever done... I said it was the most professional for me... But ya know... 19-Feb-19 09:31 AM my trailer is just a little enclosed like 8ftx5/6?ft trailer 19-Feb-19 09:31 AM with like a 6ft internal height almost, but 5ft opening on the door for height. 19-Feb-19 09:31 AM But yea... we had me, Adam, and another friend for unloading and I'd say that was JUST enough people 19-Feb-19 09:31 AM it would have taken exponentially longer with only the two of us, and by myself it would have probably just not happened lol 19-Feb-19 09:31 AM I also went to a hardware store and bought like 200 dollars in just strapping/ratcheting/tiedown tools and materials, along with like a 100 dollar run for wood for blocking things, packing materials, etc... 19-Feb-19 09:36 AM Again, most prepared I've been, least prepared Adam's been lol 19-Feb-19 09:36 AM i mean it's pain but it's kinda fun too 19-Feb-19 09:36 AM moving this old bulky HW stuff 19-Feb-19 09:36 AM you only have to accept that it will be painful 19-Feb-19 09:36 AM imho 19-Feb-19 09:38 AM oh yea for sure, you just don't want it to be your last move, or end up having to part out the thing you just bought because it went wrong :) 19-Feb-19 09:38 AM Yea, just take your time and you should be fine 19-Feb-19 09:38 AM get as many people to help as you can too 19-Feb-19 09:38 AM yep 19-Feb-19 09:38 AM The SS-60 is a cute little thing in comparison though 19-Feb-19 09:38 AM its so smol 19-Feb-19 09:42 AM yeah, bottom chamber has the same size, right? 19-Feb-19 09:42 AM but the DS-130s column is bigger 19-Feb-19 09:43 AM yea chamber looks similar, column is a TON bigger 19-Feb-19 09:43 AM and a ton heavier 19-Feb-19 09:43 AM console also looks a bit bigger ,but the console is only like 500lbs and on wheels so its not too bad 19-Feb-19 09:43 AM Vac system is also a lot bigger 19-Feb-19 09:43 AM ^ 19-Feb-19 09:43 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1558-75C84.jpg 19-Feb-19 09:43 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1556-8F278.jpg 19-Feb-19 09:43 AM there is a lot of stuff on that column... 19-Feb-19 09:47 AM bigger -> better 19-Feb-19 09:47 AM most of the time :) 19-Feb-19 09:48 AM it has a aperture changer, right? 19-Feb-19 09:49 AM Lovely. 19-Feb-19 09:51 AM I think you have to change out the aperture if you want something else. I don't think it has any piece that you can change apertures on the fly with? If thats your question 19-Feb-19 09:52 AM yeah, that's the question 19-Feb-19 09:53 AM It has a changable apurture 19-Feb-19 09:54 AM yay 19-Feb-19 09:54 AM as in "turn a knob and that changes the aperture like from circular shaped to triangular shaped or the diameter etc"? 19-Feb-19 09:55 AM Well they are all circular 19-Feb-19 09:56 AM afaik non-circular is handy for deconvolution image enhancement 19-Feb-19 09:56 AM You can put one in it's not stock 19-Feb-19 09:56 AM of course you can do deconvolution with circular apertures too but ... 19-Feb-19 09:56 AM ah ok 19-Feb-19 09:58 AM @AdamMcCombs I think he's asking if it has an aperture holder that can hold like 3 apertures and you can turn a knob to change from one to another on the fly without taking the spec chamber down and changing it out by hand 19-Feb-19 09:58 AM like this 19-Feb-19 09:58 AM https://i.ebayimg.com/images/g/1J4AAOSwUTZcZ5nk/s-l500.jpg 19-Feb-19 09:58 AM Yeah 19-Feb-19 09:58 AM mine doesn't have that does it? 19-Feb-19 09:58 AM or a DS-130 doesn't 19-Feb-19 09:58 AM It does 19-Feb-19 09:58 AM \o/ 19-Feb-19 09:59 AM oh hrm, ok, I must just be thinking of the final aperture then I suppose 19-Feb-19 09:59 AM Yeah 19-Feb-19 09:59 AM apologies 19-Feb-19 09:59 AM Most have it as a final app 19-Feb-19 09:59 AM But yours is special 19-Feb-19 09:59 AM hehe 19-Feb-19 09:59 AM it's so special dude 19-Feb-19 10:00 AM ah... I see lol 19-Feb-19 10:01 AM do you guys give your scopes names? 19-Feb-19 10:24 AM I'm both jealous of your big scopes and also glad that mike doesn't take up so much space 19-Feb-19 10:24 AM *mine 19-Feb-19 10:26 AM well i want such a desktop SEM too 19-Feb-19 10:26 AM you can take it with you 19-Feb-19 10:27 AM It took two of us to throw it in the backseat of a compact rental car. 19-Feb-19 10:27 AM but they are relatively pricey 19-Feb-19 10:28 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-4C665.png 19-Feb-19 10:28 AM compared with old "tombstone" hardware 19-Feb-19 10:28 AM yeah, that's compact 19-Feb-19 10:28 AM Luckily the cops didn't pull me over, there would have been questions 19-Feb-19 10:29 AM because there is a radiation sign? ^^ 19-Feb-19 10:29 AM Yep! 19-Feb-19 10:29 AM lol 19-Feb-19 10:29 AM you weren't speeding with trailer lights out with 2000lbs of equipment in a beat to crap trailer :P 19-Feb-19 10:29 AM but man that 5:30 hours of driving both ways made that a LONG day 19-Feb-19 10:29 AM Adam at-least got to nod off in the passenger seat 19-Feb-19 10:32 AM Man I'd be f'd without Adam's help troubleshooting my machine. The man is a saint! 19-Feb-19 10:34 AM He's just passionate about something :P So he knows a lot about it. 19-Feb-19 10:34 AM Just like I know too much about mainframes lol 19-Feb-19 10:34 AM Anyone who's ever emailed me about getting one running gets a long email in response :) 19-Feb-19 10:35 AM Are there hobbyists buying old mainframes and putting them in their basements? 19-Feb-19 10:36 AM yup, just far and few between 19-Feb-19 10:36 AM you have to really like sitting at a terminal all day lol 19-Feb-19 10:36 AM but yea, mostly people who collect old computers, and mainframes are kinda far and few between 19-Feb-19 10:36 AM many more people getting old DEC PDP-8s/11s, Apple IIs, etc... 19-Feb-19 10:36 AM vintage computing is fun, and to be honest helps with a lot of knowledge of the electronics side of this 80s SEM :P 19-Feb-19 10:36 AM Also the Aesthetic is spot on with this scope. 19-Feb-19 10:39 AM Maybe you could image a chip from an Atari with it. Period-correct SEM imaging! 19-Feb-19 10:40 AM I have an Atari system 19-Feb-19 10:40 AM honestly, I have TONS AND TONS of wafers and dies I'd love to image 19-Feb-19 10:40 AM and old pocket watch parts :P 19-Feb-19 10:40 AM I have way too many niknaks 19-Feb-19 10:40 AM also with the specimen size of 5" max... oh man... 19-Feb-19 10:40 AM I can look at all the things 19-Feb-19 10:52 AM Do you have EDS? 19-Feb-19 03:18 PM Awwww. Connor pulled his first first vacuum 19-Feb-19 03:18 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190219_181710-77A11.jpg 19-Feb-19 10:24 PM Congrats! 19-Feb-19 11:36 PM Morning! \o/ 20-Feb-19 01:05 AM moin! 20-Feb-19 01:15 AM @AdamMcCombs Naw, they're growing up so fast! 20-Feb-19 01:20 AM emptying 20-Feb-19 01:26 AM moin 20-Feb-19 07:46 AM moin! 20-Feb-19 08:59 AM So we had started pumping down the SEM last night, Diffusion pump seems to work great, the roughing pump is running well but both oil mist filters I had are shot, we bodged one together for the mean time. 20-Feb-19 09:03 AM ok nice so far 20-Feb-19 09:41 AM That sounds very Apollo 13-bodge. XDDDD 20-Feb-19 09:45 AM Joined the server. 20-Feb-19 09:57 AM <3Victoria#2375> Joined the server. 20-Feb-19 10:00 AM Welcome everyone! 20-Feb-19 10:29 AM Joined the server. 20-Feb-19 11:07 AM Welcome! 20-Feb-19 05:05 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1581-48BB2.jpg 20-Feb-19 08:34 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1583-4308D.jpg 20-Feb-19 08:57 PM yay 20-Feb-19 09:11 PM what's the pattern above? char gen? 20-Feb-19 10:27 PM Niiiice! Conmegagrats! 20-Feb-19 10:29 PM cant wait to ge my ds130 20-Feb-19 10:29 PM @Conmega since youve an igp on top, has it a LaB6 source? 21-Feb-19 12:14 AM moin 21-Feb-19 12:14 AM ok u night persons 21-Feb-19 12:17 AM Boin! 21-Feb-19 11:01 AM @N00N my machine has the LaB6 option, but I have no LaB6 filaments, my machine came with about 5 filaments I think it was all tungston. Which the IGP, if we can get it going, will give me great filament life 21-Feb-19 12:22 PM doesn't that just more or less run itself? 21-Feb-19 12:23 PM Not at all on this one 21-Feb-19 12:24 PM oh, I figured this was the kind of thing that was self controlling, you'd just apply voltage and it'd bring the vacuum down lower 21-Feb-19 12:25 PM Ion pumps are way harder to deal with than that 21-Feb-19 12:25 PM In therory that's what should happen 21-Feb-19 12:25 PM But just getting an ion pump to start can be an ordeal 21-Feb-19 12:25 PM I know the feeling 22-Feb-19 01:48 AM Morning! \o/ 22-Feb-19 01:52 AM Moin! 22-Feb-19 10:14 AM pfew, its been a crazy last 7 days 22-Feb-19 10:14 AM dropped Adam off at the train station this morning 22-Feb-19 10:14 AM now I'll be on my own with the scope hopefully not going to blow it up without professional supervision :) 22-Feb-19 10:49 AM hehe 22-Feb-19 11:13 AM Got my first real SEM image 22-Feb-19 11:13 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Export.20190222.000008-C44F4.tif 22-Feb-19 11:13 AM ...apparently Discord won't show TIFF images. Here is a JPEG... 22-Feb-19 11:13 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Export.20190222.000008-FF8D9.jpg 22-Feb-19 11:13 AM Sometimes I'm getting slight glitches in the image. But when I use the scope's software to export the image, the glitches will go away... Hm... 22-Feb-19 11:13 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20190222.000011-3CC01.jpg 22-Feb-19 11:58 AM Niiiiiice 22-Feb-19 11:58 AM I envy you all. 22-Feb-19 12:32 PM nice! 22-Feb-19 12:32 PM and hey, I'll image something for people, its just going to cost a deposit into the filament tip jar ;) 22-Feb-19 12:35 PM Looking nice! I think this weekend I'm going to host a SEM how to, if anyone is interested. 22-Feb-19 12:42 PM @AdamMcCombs, an online type thing or in person? 22-Feb-19 12:45 PM Online 22-Feb-19 12:45 PM I'm thinking Sunday for it, I'm guessing at least you and @Conmega would be interested 22-Feb-19 12:46 PM I'd be interested. I have no idea what I'm doing! 22-Feb-19 12:46 PM I'm about to take off, let's talk more about this later 22-Feb-19 12:48 PM Yea I want to run my scope over the weekend, hoping to finish the cooling loop and fix air leaks tonight 22-Feb-19 12:48 PM would be nice to not have the compressor run all the time 22-Feb-19 12:48 PM Carful with those air leaks, that could take your scope down hard 22-Feb-19 12:49 PM well right I'd have to ensure the valve is working right, I can do that on the bench with a powersupply 22-Feb-19 12:49 PM take it off, rebuild it, fix the wiring, test 22-Feb-19 12:49 PM more effort then bodging it on the scope, but will be a longer term fix 22-Feb-19 12:49 PM I'm going to tackle that one major leak we noticed first, then see where that gets me 22-Feb-19 12:49 PM if I recall that doesn't have the line running over the top of it so it shouldn't be too much of a pain to remove 22-Feb-19 12:49 PM I'll also figure out what valve it goes to and see which one I'll be affecting so I can watch carefully when I bring it back up 22-Feb-19 12:49 PM I'll post info about it as I go 22-Feb-19 12:53 PM What's the story with the leak? Looks like you were getting an image a couple days ago. I assume that means there were no leaks... 22-Feb-19 12:54 PM uhm, not vacuum leaks, air leaks from the 70psi air feed 22-Feb-19 12:54 PM which controls the valves in the vacuum system 22-Feb-19 12:54 PM ooooh 22-Feb-19 12:54 PM the pneumatic valves which control the air are old and o-rings in them are hard as rocks 22-Feb-19 12:54 PM because some of those valves get held in one position when up and running 22-Feb-19 12:54 PM and as such the coils get hot 22-Feb-19 12:54 PM and the orings dry out fast 22-Feb-19 12:54 PM so it needs servicing 22-Feb-19 12:54 PM right now my small compressor is running like ever 4 minutes or so 22-Feb-19 12:54 PM which is annoying and bad 22-Feb-19 12:54 PM so trying to resolve as many of those leaks as possible 22-Feb-19 12:56 PM Your machine is probably like an order of magnitude more complex than mine 22-Feb-19 12:56 PM I found a very very similar valve at the surplus place I go to, I'll practice on tearing that one down first to be sure its viable, if not, I'll leave the leaky valve in until I can find an exact drop in replacement. 22-Feb-19 12:56 PM I believe it is lol 22-Feb-19 12:56 PM well 22-Feb-19 12:56 PM in ways it is 22-Feb-19 12:56 PM in other ways its not 22-Feb-19 12:56 PM its controlled by a z80... which is very simple lol 22-Feb-19 12:56 PM but its also a lot bigger of a machine I believe, much more complex vacuum system 22-Feb-19 12:56 PM well and optics too 22-Feb-19 12:56 PM @AdamMcCombs correct me if I'm wrong, I know your trying to butt in to explain but I'm trying to also make sure I learned something over this last week ;) 23-Feb-19 02:46 AM moin 23-Feb-19 03:18 AM Morning! \o/ 23-Feb-19 12:30 PM got some hose hardware today, for the flow bench.. not sure how many hose clamps I have though.. the lil hardware store was selling htem by the piece, and didnt have enough of the size I needed.. and were expensive.. but I know auto stores have packs for cheap 23-Feb-19 12:30 PM this will be for determining the volumetric efficiency of the fuel pump at various RPM, SCV%, and Temperatures 23-Feb-19 12:30 PM for instance, if the engine is at 1800rpm and there is a desire for 0.2cc fuel injection into the rail on the next revolution, and the fuel is X hot, what % should the SCV be set at 23-Feb-19 12:30 PM which is really the only variable capable of being changed 23-Feb-19 12:30 PM I wish the data was publically, or even NDA, available 23-Feb-19 02:31 PM had to run back out, this time with solenoids in hand.. the phrase of the parts I got made me think I was getting barbs that were 3/8" but were in fact 1/4 ("1/4 x 3/8" Hose Barb").. so I had the opposite of what I needed 23-Feb-19 02:31 PM 1/4 hose x 3/8 barb is the correct phrase 23-Feb-19 02:31 PM I was not fully expecting on goign to the hardware store earlier.. so I didnt bring it with me, but we eventually came onto one during the dog walk.. anywho, yay 23-Feb-19 11:32 PM XD! 23-Feb-19 11:32 PM Those imperial measurements make my head hurt. (It's a friendly joke, but let me know if it is sensitive for you and I'll back out, we mainly like to bother Adam with that) 24-Feb-19 12:54 AM moin! 24-Feb-19 01:26 AM Gloin! 24-Feb-19 01:26 AM T-10,5h 24-Feb-19 01:26 AM ish 24-Feb-19 01:26 AM Yeah! 24-Feb-19 01:26 AM (I hope you aren't talking about the voicechat, because in that case you'd be a bit late) 24-Feb-19 02:29 AM Whatever, yes, voicechat 24-Feb-19 02:29 AM ah 24-Feb-19 02:29 AM ffs 24-Feb-19 02:29 AM you were right, I just was not awake enough to realise we use a 12 hour system instead of 10 hours XD 24-Feb-19 03:10 AM BAHAHAHAHAHAHHA 24-Feb-19 09:09 AM moin! 24-Feb-19 09:42 AM moin 24-Feb-19 07:41 PM evenin 24-Feb-19 07:42 PM Wanna join in on alignment chat? 24-Feb-19 07:42 PM sure! 24-Feb-19 07:42 PM where? 24-Feb-19 07:43 PM accept the friend request 24-Feb-19 07:45 PM I have one friend! 24-Feb-19 10:35 PM moin 24-Feb-19 11:58 PM boing! \o/ 25-Feb-19 01:26 AM Moin! 25-Feb-19 11:05 AM Joined the server. 25-Feb-19 11:05 AM moin! 25-Feb-19 12:41 PM hmmm. how do i assess the ability of a given stainless steel "thing" to stand up to vacuum (or rather: to the one bar of air pressure from the outside)? 25-Feb-19 12:41 PM i got a vessel from the scrapyard some time ago that i wanted to use, but i'm not sure i want to evacuate it... the flanges i thought were KF40 on the top might not even be KF, 'cause at least the two flanges i cut off a similar but destroyed chamber seem to be neither KF32 nor KF40 25-Feb-19 04:02 PM Variac arrived! 25-Feb-19 04:24 PM works on the motor 25-Feb-19 07:34 PM Joined the server. 25-Feb-19 09:54 PM moin 25-Feb-19 11:13 PM @Pan Da if you can bend it with your finger, maybe it's a bit too flimsy. XD (totally made up) 25-Feb-19 11:13 PM Noxz, great, how was the exam, btw!¿ 25-Feb-19 11:13 PM Also: 25-Feb-19 11:13 PM Groin! \o/ 26-Feb-19 12:09 AM Moin! 26-Feb-19 05:26 AM Joined the server. 26-Feb-19 05:29 AM Welcome! 26-Feb-19 08:15 AM Joined the server. 26-Feb-19 08:43 AM Joined the server. 26-Feb-19 08:47 AM Welcome, come, ome...! XD 26-Feb-19 08:51 AM Hey. I've been 'send' here by the amp hour podcast but you might have expected that. Hopefully this community got a few new members from it. I was looking for a SEM forum as I'm in the process to buy a SEM with my hackerspace Bitlair (Amersfoort, the Netherlands). A few other participants will join when they feel like it. 26-Feb-19 08:52 AM Cool, welcome! 26-Feb-19 08:52 AM If you've got any questions about SEMs ask @AdamMcCombs 26-Feb-19 08:57 AM @GigaSquirrel Thank you. What's the easiest way of navigating the channel? I'm used to forums where you just find a topic with all the information a a specific topic. This is useful as information on keeping a 80's SEM running will still be valid as long the SEM exist. Discord I've used where the history did not matter much. 26-Feb-19 08:58 AM of course you can search for keywords, but this is still just a regular chat 26-Feb-19 08:58 AM no information gets deleted, you just have to scroll for some time 26-Feb-19 09:00 AM I'll search around. 26-Feb-19 09:00 AM Good luck 26-Feb-19 09:11 AM nice 26-Feb-19 09:31 AM @jwrm22 you can also ask again, noone is going to mind much. XD 26-Feb-19 09:40 AM I would also suggest sending a friend request to Adam. 26-Feb-19 10:10 AM Joined the server. 26-Feb-19 10:59 AM Welcome! 26-Feb-19 03:48 PM Joined the server. 26-Feb-19 06:41 PM Welcome! 26-Feb-19 09:31 PM Joined the server. 26-Feb-19 10:16 PM Welcome! 26-Feb-19 10:28 PM Joined the server. 26-Feb-19 10:42 PM Ok everyone I setup a music bot. Go to #🎶beeps-boops🎶 and join to bep bop voice channel to try it out 26-Feb-19 10:42 PM use !join to start 26-Feb-19 10:42 PM and !help to get commands 26-Feb-19 10:53 PM Welcome! 26-Feb-19 11:15 PM (rythm is the music bot) 26-Feb-19 11:39 PM Borning! \o/ 27-Feb-19 12:31 AM moin 27-Feb-19 12:58 AM Joined the server. 27-Feb-19 01:00 AM Joined the server. 27-Feb-19 01:00 AM hi, I've got a Jeol JSM-T200 that needs work... got it in 2015... and a Seiko SMI3200 FIB that was sold in working order, purchased in 2017... just got around to ordering some SJOOW cable a week ago, along with some NEMA l6-30 connectors/plugs to get it plugged into the wall of my garage. Otherwise gonna tack up some 6 mil plastic around the FIB in the garage, and silicone the plastic to the floor, to keep the major dust and outdoors debris out. Hope to have all the cable supplies by next week! 27-Feb-19 01:00 AM Otherwise been learning a lot about FIB lithography lately on an FEI FIB 200, gonna be doing some high-res experiments to get glyphs/text written with a few 100nm features 27-Feb-19 01:08 AM cool 27-Feb-19 01:10 AM using PMMA as the resist so far, which is supposed to have some of the best res 27-Feb-19 01:15 AM what have you paid for the SMI3200? 27-Feb-19 01:15 AM (any chances to get one for free) 27-Feb-19 01:17 AM actually a friend paid for it, $1500 27-Feb-19 01:17 AM it was in fact being offered for free 27-Feb-19 01:17 AM to a 501(c)3 27-Feb-19 01:17 AM ok, that's cheap i assume? 27-Feb-19 01:17 AM (nonprofit) 27-Feb-19 01:17 AM ah ok 27-Feb-19 01:17 AM yeah super cheap 27-Feb-19 01:17 AM I paid $3k to get it home 27-Feb-19 01:18 AM hehe 27-Feb-19 01:18 AM yeah, that's okayish pricing for moving such a beast 27-Feb-19 01:18 AM sold from the original importer/sales/installers 27-Feb-19 01:18 AM did all the moving myself with a friend's help, rented an air-ride trailer, rented forklifts on both ends, crated everything ourselves in the alley behind the seller's shop 27-Feb-19 01:18 AM it was a grueling 2 days 27-Feb-19 01:19 AM ah 27-Feb-19 01:19 AM the hard way 27-Feb-19 01:19 AM remembers me that i've to move a ISI DS-130 in 3 weeks 27-Feb-19 01:20 AM I guess I was sneezing or something at the time too, and got to the sales shop, talked with the folks a while, then asked to use the restroom... went to wash my hands and noticed I had a burst blood vessel in my eye 27-Feb-19 01:20 AM looked like a total freak 27-Feb-19 01:20 AM black eye style? 27-Feb-19 01:21 AM if I hadn't come for the FIB... they could have probably assumed I was some alcoholic bum 27-Feb-19 01:21 AM I was shocked to see my eye all red 27-Feb-19 01:21 AM never happened before to me 27-Feb-19 01:21 AM yeah, looks scary 27-Feb-19 01:21 AM srsly 27-Feb-19 01:21 AM friend of mine had it one day 27-Feb-19 01:21 AM i told him "dude, your eye??!" 27-Feb-19 01:22 AM I also was wearing "construction work" clothes, so looked pretty bummy 27-Feb-19 01:23 AM but the doctor said it's no problem, 1-2 weeks and the eye becomes normal 27-Feb-19 01:23 AM friend of mine was super scared 27-Feb-19 01:23 AM mmm, yeah I was all good soon after 27-Feb-19 01:23 AM once I got the hell outta California, lol 27-Feb-19 01:24 AM Welcome, and nice! 27-Feb-19 01:24 AM thanks, glad to have joined 27-Feb-19 01:24 AM well, I shouldn't have joined at 1am 27-Feb-19 01:24 AM I need to sleep 27-Feb-19 01:24 AM ttyl 27-Feb-19 01:25 AM See you later 27-Feb-19 03:30 AM Joined the server. 27-Feb-19 03:31 AM Welcome! 27-Feb-19 04:07 AM Joined the server. 27-Feb-19 05:51 AM Joined the server. 27-Feb-19 06:45 AM Your own garage FIB. That’s super cool. 27-Feb-19 09:08 AM Lotsa newcomers! Welcome to all. 27-Feb-19 07:12 PM Joined the server. 27-Feb-19 07:12 PM Hello everyone! 27-Feb-19 07:14 PM Hey 27-Feb-19 10:31 PM Welcome! 27-Feb-19 11:41 PM Eightdot and Thomastheo are from Hackerspace Bitlair as well. 28-Feb-19 02:21 AM moin 28-Feb-19 02:27 AM moin! 28-Feb-19 02:55 AM gloin! 28-Feb-19 02:57 AM on my way to uni, finally listening to adams amp hour podcast :) 28-Feb-19 02:57 AM Got unlimited mobile data this month, gotta use it :D 28-Feb-19 05:58 AM Why only this month? 28-Feb-19 06:06 AM I switched operator, that's a welcome gift 28-Feb-19 06:06 AM after that 2.5 gb per month 28-Feb-19 09:46 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-1BB70.png 28-Feb-19 09:46 PM Woot got the MKS 901P talking 28-Feb-19 10:00 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1651-2A14C.jpg 28-Feb-19 10:00 PM An old Lenovo 20V brick, USB to serial adapter. And a DB15. 28-Feb-19 10:00 PM Again, these are pretty decent piezo/pirani combo gauges, needs 9-30VDC and RS232 for most models commonly available and they can be had for 30-50 bucks on ePay 28-Feb-19 11:31 PM Boinging! \o/ 01-Mar-19 12:01 AM moin 01-Mar-19 12:41 AM that price in US...shipping to wherever else would be another matter. 01-Mar-19 12:41 AM sad 01-Mar-19 12:46 AM Moin! 01-Mar-19 08:39 AM @Nixie I'm going to be putting together your box this weekend and shipping it out early next week. If you want one of these 901p gauges I can send you mine and I can buy another. That along with the ion gauge should give you a pretty full range on vacuum. 01-Mar-19 08:59 AM Thanks, but literally I only have money for shipping. 01-Mar-19 08:59 AM (besides, I'm useless at programming, so I can't really hack anything to read the serial port of that) 01-Mar-19 08:59 AM Anyways, thanks for the help and effort ^^ 01-Mar-19 09:07 AM @Nixie the software is freely available from MKS 01-Mar-19 09:07 AM you can just data log 01-Mar-19 09:07 AM Still, I can only pay shipping. 01-Mar-19 09:07 AM someday in the future, don't worry. 01-Mar-19 09:08 AM okie I just mentioned that mostly for others information too, since it kinda makes the gauges more usable for some people 01-Mar-19 09:09 AM https://tenor.com/view/goodjob-thumbsup-nice-excellent-gif-7248436 01-Mar-19 09:11 AM Woot just ordered, hopefully, the rest of the PTC 4mm air stuff for the SEM, going to be upgrading it to way newer SMC valve blocks and PTC air fittings and hose for the pneumatic vacuum system 01-Mar-19 09:11 AM vs the old air system that is leaking badly, has old valves that are worn out and leaking, and also has a holding wattage of like 11W, which makes them hot to the touch when holding... 01-Mar-19 09:11 AM the new SMC valves are like 0.1W :P 01-Mar-19 09:14 AM I'll just be happy to not hear the compressor run every 5 minutes uhg 01-Mar-19 09:14 AM Every 6? 01-Mar-19 09:14 AM XDDDD 01-Mar-19 09:14 AM something like that 01-Mar-19 09:14 AM Will be good for the voicechats 01-Mar-19 09:14 AM XDDDD 01-Mar-19 09:14 AM nah it really shouldn't be using any air when its up and running 01-Mar-19 09:14 AM the only time it should use air is when coming up or going down or opening the second stage or something 01-Mar-19 09:14 AM when its changing state basically 01-Mar-19 09:14 AM and even then it shouldn't be using much 01-Mar-19 09:15 AM (i know, I know, just trolling you) 01-Mar-19 09:15 AM :P 01-Mar-19 09:15 AM apparently some JEOLs run off tanks of N2 because they just use so little 01-Mar-19 09:15 AM What is the benefit of running the air system with N2? 01-Mar-19 09:15 AM I'd go through a tank of N2 in like a half hour probably at the moment lol 01-Mar-19 09:15 AM not having a compressor in the building? 01-Mar-19 09:16 AM ah! 01-Mar-19 09:16 AM I guess? 01-Mar-19 09:16 AM they are specced to run off that tank for like 01-Mar-19 09:16 AM but...a scuba tank would work and be cheaper 01-Mar-19 09:16 AM months 01-Mar-19 09:16 AM (scuba, or compressed, or CO2) 01-Mar-19 09:16 AM since most in service SEMs stay up 24/7 they just shut the HV off and open the specimen chamber now and then 01-Mar-19 09:16 AM I think the thing with N2 is you get a higher density in the canister 01-Mar-19 09:16 AM and its really not all that expensive 01-Mar-19 09:16 AM considering you'd probably be paying thousands a month for a service contract with some company 01-Mar-19 09:17 AM XD, okay, yes, in that kind of scene. 01-Mar-19 09:17 AM yea at home you could just run it off compressed air 01-Mar-19 09:17 AM its not a big deal 01-Mar-19 09:18 AM unless leaks 01-Mar-19 09:18 AM XDDD 01-Mar-19 09:18 AM I got today the KF25 weldable flange for the assembly 01-Mar-19 09:18 AM Hopefully I'll be testing electron beam shenanigans in three or four weeks. 01-Mar-19 10:35 AM usually you have LN2 in a building where you'd find a sem, so you have nitrogen instead of compressed air 01-Mar-19 10:35 AM as it basically comes free with the LN2 01-Mar-19 11:01 AM or you have an attachment for your sem that needs LN2 itself, then you're already there 01-Mar-19 11:56 AM @Nixie @Conmega Reason for using N2 interested of compressed air is for the health of the pnumatic system and to improve room conditions, in addition to the fact that it's a good ideas vent with N2. Instruments that run on building air need expensive air dryers to ensure the valves don't rust out, and scopes that use compressors have to deal with the vibrations from them. So you run the system off of dry N2 and don't have to deal with any of those problems. 01-Mar-19 02:46 PM So uhm... anyone know what the difference between different styles of Residual Gas Analyzers are? I primarily see two types... One with a really short sensor, one with a really long detector head. I kinda get roughly how the long style detector works, Sam Zeloof roughly describes it in one of his videos about an RGA. Clearly the short style can't operate quite the same way. Are they just grossly gimped, limited in some way? Just kinda considering what the differences between them are for second hand market since they all go for around the same money. 01-Mar-19 02:46 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Transpector-XPRplus-3-sil-right-SMALL-7E241.png 01-Mar-19 02:46 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/TranspectorMPH_web-6C58F.png 01-Mar-19 02:46 PM I assume the long style is an Open Ion Source style? 01-Mar-19 02:46 PM huh I guess there is also one kinda inbetween in size, probably the longer one has an electron multiplier or something 01-Mar-19 02:46 PM I guess the detector types are both FC/EM on them I just suppose they will be limited in their "amu"? which I suppose is the range of gases you can measure since well the length of the detector matters when detecting heavier gas particles I suppose. 01-Mar-19 09:56 PM I think “smaller” ones are OIS since it’s “hidden” in the process vessel 01-Mar-19 09:56 PM It’s really just a quadrupole. A mass spectrometer. The AMU range will be determined by the RF and DC amplitudes reachable on the rods from the driver, and the frequency 01-Mar-19 09:58 PM OIS? sorry? 01-Mar-19 09:58 PM is an ignorant fool 01-Mar-19 10:00 PM Open ion source vs closed ion source 01-Mar-19 10:01 PM ahh ok, right 01-Mar-19 10:01 PM guess I didn't realize the longer ones could be closed ion source but it makes sense 01-Mar-19 10:01 PM just weighing options for when I eventually get one used on fleabay 01-Mar-19 10:01 PM the real concern is software... I know Sam Zeloof got his used and somehow has the software so... wondering if he can help with that. 01-Mar-19 11:11 PM The SRS ones are RS232 interface I think 01-Mar-19 11:11 PM Should be pretty easy to decode? 01-Mar-19 11:49 PM All the ones I was looking at had RS232 at minimum. I posted one I was looking at in #swap-meet 02-Mar-19 06:18 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_-m2bsww-7E70C.jpg 02-Mar-19 06:18 AM Well, that's more or less how it's going to be. 02-Mar-19 06:18 AM 02-Mar-19 10:21 AM electron beam etching to balance the tmp? :P 02-Mar-19 10:40 AM Rofl. There will be something in between the beam and the turbine 02-Mar-19 02:49 PM also @Applied_Ion in my recent LDS vacuum order I bought a 10 pack of 6" conflat copper, if you need some you can buy them from me at cost if you want I probably only need a few of them but I bought a 10 pack because buying like 3 at the cost of individual is just uhg 02-Mar-19 02:49 PM since I know your doing 6" conflat 02-Mar-19 02:49 PM 46 bucks for a 10 pack so 4.60 a pop 02-Mar-19 02:51 PM Nice! I. May actually take you up on that 02-Mar-19 02:54 PM I just thought about it :P glad to help in any way, especially with saving money haha 02-Mar-19 02:54 PM idividual gaskets are 6 bucks a pop so its definitely worth buying 10 packs and splitting them up 02-Mar-19 02:54 PM at-least your not doing 8" conflat... 10 pack was 69 dollars uhg 02-Mar-19 02:56 PM Yeah for sure lol. 8" has gotta be a pain to deal with. I've got a friend with 13" conflat hardware he is planning on using. They don't even make gaskets for those, gotta use custom wire seals 02-Mar-19 02:57 PM oh crap yea they only have 13.25" seals on LDS shopper... 02-Mar-19 02:57 PM 13" is so common to see on ePay unless they are missing the measurement by a quarter inch 02-Mar-19 02:58 PM Speaking about seals, are the chinese viton KF gasgets ok? 02-Mar-19 02:58 PM And how is the chinese KF hardware in general? 02-Mar-19 02:58 PM sure it's not hugely expensive but I'd still rather not spend money on total garbage 02-Mar-19 02:59 PM I've gotten a few pieces 02-Mar-19 02:59 PM I mean its hard to screw up KF... 02-Mar-19 02:59 PM its a flat surface, a centering ring whos job is to mostly just hold the oring in place and center those surfaces 02-Mar-19 02:59 PM and a viton oring 02-Mar-19 03:00 PM could be roughly machined with tons of scratches 02-Mar-19 03:00 PM I've gotten some pieces and they are really well machined 02-Mar-19 03:00 PM like scarily so 02-Mar-19 03:00 PM and even if it has bad scratches you can sand and resurface easy enough 02-Mar-19 03:00 PM its just like getting used KF with scratches 02-Mar-19 03:00 PM leme get a photo of one I have in a bit 02-Mar-19 03:00 PM but yea from what I've heard they are ok 02-Mar-19 03:00 PM the easiest part to be "bad" is the viton oring 02-Mar-19 03:00 PM but you can get those and use the rest of it still 02-Mar-19 03:00 PM and the orings should be the cheapest part 02-Mar-19 03:01 PM Yeah 02-Mar-19 03:05 PM can't wait to get chamber setup 02-Mar-19 03:05 PM seriously just need a way to attach my turbo 02-Mar-19 03:07 PM Yeah I've gotten both chinese kf hardware and orings. Very nice quality, wouldn't be able to tell the difference from the big name brands. Not all are like this - I've seen some real lousy ones on ebay, but so far I'm happy with mine, no issues yet 02-Mar-19 03:08 PM Ok, good to hear. 02-Mar-19 03:10 PM also @Applied_Ion you undersold this model XD 02-Mar-19 03:10 PM really nice work 02-Mar-19 03:21 PM yea wow that is weird 02-Mar-19 03:21 PM its like so similar to ISO but the dimensions are wrong 02-Mar-19 03:22 PM Oh thanks! That was a while ago lol. And yeah, the butterfly valve is close but not quite. The gate valve is definitely ASA 02-Mar-19 03:23 PM its so close to ISO 160 too.... which is what my turbo is 02-Mar-19 03:23 PM could probably just make it work... maybe... 02-Mar-19 03:23 PM the center oring for an iso 160 would just barely be too small for the inner diameter of that tube 02-Mar-19 03:23 PM 6.25" vs 6.024" uhg 02-Mar-19 03:23 PM might be-able to make it work with a custom centering ring and some custom clamps 02-Mar-19 03:32 PM Yeah, it's just off enough to be a nuisance to use 02-Mar-19 03:43 PM I used chinese KF16 and everything has worked well so far. 02-Mar-19 03:44 PM sweet 02-Mar-19 03:45 PM (including corrugated 500mm tube, btw) 02-Mar-19 03:45 PM I made my own KF16 glass isolator, though 02-Mar-19 05:40 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1656-93EDC.jpg 02-Mar-19 05:40 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1658-64BEF.jpg 02-Mar-19 05:40 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1655-62EF4.jpg 02-Mar-19 05:40 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1657-27A9E.jpg 02-Mar-19 05:40 PM This poor Alcatel has been a bit neglected. 02-Mar-19 07:35 PM yea I tilted it on its side while cleaning 02-Mar-19 07:35 PM heard some kind of metal piece slide on the inside... 02-Mar-19 07:35 PM pretty sure this pump is SUPER DED 02-Mar-19 07:35 PM finished cleaning and filled it with used pump oil/flushing fluid mix because screw wasting new stuff on this thing with how nasty it was just for a first flushing 02-Mar-19 07:35 PM place your bets on if its completely blown up or if that thing sliding inside is perfectly fine XD 02-Mar-19 07:47 PM it... pumps... 02-Mar-19 07:47 PM but it doesn't sound healthy... 02-Mar-19 08:04 PM https://imgur.com/PHYJQb2 02-Mar-19 08:04 PM I mean it seems to pump good 02-Mar-19 08:04 PM audio if you go to imgur I think 02-Mar-19 08:49 PM I’m not sure if this is standard or what diameter it is exactly (where do you take the measurement) but it was like “do you want it free” and I’m like yussss 02-Mar-19 08:49 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-24D1A.jpg 02-Mar-19 08:49 PM It’s a bit dirty and rusty... what’s the best way to clean this stuff? Both inside for vacuum and outside for pretty 02-Mar-19 08:53 PM looks like ASA standard? 02-Mar-19 08:53 PM https://www.lesker.com/newweb/flanges/flanges_technicalnotes_asa_1.cfm 02-Mar-19 08:53 PM These flanges are sized by the connecting pipe's nominal I.D. in inches. The normal range is: 1", 1.5", 2", 3", 4", 6", 8", and 10", although some manufacturers make sizes up to 36". They have large diameter bolt holes through the rim—a legacy from positive pressure uses. Consequently, for any given tube diameter, ASA flanges have much larger O.D.s than other flange types. The adaptation and adjustment to suit vacuum conditions led to a deterioration of standards. 02-Mar-19 08:53 PM first thing to try would be just wiping it down of any contaminates with like acetone/alcohol/etc 02-Mar-19 08:53 PM something to just clean it up, get gunk off 02-Mar-19 08:53 PM for polishing... sealing surfaces use something like this if its not scratched deeply or anything https://www.amazon.com/gp/product/B076JKWBP2/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1 02-Mar-19 08:53 PM outside just use whatever metal polish... like brasso lol 02-Mar-19 08:53 PM @a_quiet_scientist 02-Mar-19 08:58 PM It’s 4” I think 02-Mar-19 09:01 PM cool! 03-Mar-19 12:25 AM Maybe add scotch brite pads for polishing the outside. 03-Mar-19 12:48 AM ehh... thats too much really 03-Mar-19 12:48 AM unless its really really really crusty 03-Mar-19 12:48 AM from the photo you'll just want brasso tbh 03-Mar-19 12:48 AM you'll rough up the surface with scotch brite 03-Mar-19 01:14 AM no, no, I meant the super thin one used for polishing. 03-Mar-19 01:14 AM also: 03-Mar-19 01:14 AM \o/ 03-Mar-19 01:17 AM anyone here doing CVD or ALD? I am thinking of building an ALD, possibly starting in a few months, and was informed I should start by converting a CVD or etch system (versus starting from an oven and various parts, as described here http://diyhpl.us/~nmz787/pdf/Cost-Effective_Systems_for_Atomic_Layer_Deposition.pdf) (another open-source paper on CVD https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0210817) 03-Mar-19 01:18 AM yawn Moin! 03-Mar-19 01:19 AM (I still have a bunch of reading to do regarding what materials I need to aim to grow, but generally a conductive layer for quantum tunneling current measurements across a nanopore, in a biochemical mix mostly consisting of water) 03-Mar-19 01:19 AM probably need to build the Dan Berard STM first, so I have some tunneling experience first 03-Mar-19 01:22 AM Woah, good luck! (only doing sputtering/oven construction, so can't help, but maybe @Applied_Ion can. 03-Mar-19 01:25 AM have been using this paper as a goal to reproduce http://diyhpl.us/~nmz787/pdf/Fabrication_of_sub-20_nm_nanopore_arrays_in_membranes_with_embedded_metal_electrodes_at_wafer_scales.pdf 03-Mar-19 01:25 AM but at this point I'm questioning whether platinum is really needed, or if this is a case of "everyone else in bio/electrochem is using Platinum electrodes, so we should too" 03-Mar-19 01:25 AM gotta revisit and dig deeper into electrochem 03-Mar-19 12:21 PM Is there any way to determine if a CF flange has a copper ring or the viton variant without taking it apart? 03-Mar-19 12:21 PM because my TMP has some weird Al ring around something 03-Mar-19 12:21 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190303_212617-F66DD.jpg 03-Mar-19 12:21 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190303_212632-9AC13.jpg 03-Mar-19 12:44 PM maybe you can try spraying solvents like DCM on the outside to see if some diffuses into it with the hornet? 03-Mar-19 12:44 PM copper shouldn't do anything 03-Mar-19 12:45 PM to see if it dissolves the rubber? 03-Mar-19 12:48 PM if its NBR yeah, that wouldn't be too nice 03-Mar-19 12:48 PM but viton should stand it 03-Mar-19 01:17 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190303_221602-28D7A.jpg 03-Mar-19 01:17 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190303_221607-18958.jpg 03-Mar-19 01:17 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190303_221556-B0921.jpg 03-Mar-19 01:17 PM well f this 03-Mar-19 01:18 PM And...? 03-Mar-19 01:18 PM Oring or cf? 03-Mar-19 01:18 PM neither 03-Mar-19 01:18 PM this looks weird 03-Mar-19 01:18 PM Rofl 03-Mar-19 01:18 PM what, foto 1 and 2 ? 03-Mar-19 01:19 PM the Al itself is the seal 03-Mar-19 01:19 PM is it the same part?! 03-Mar-19 01:19 PM Will be arriving at vpicechat in 30 minutes or so 03-Mar-19 01:19 PM Thst doesn't sound like a good seal 03-Mar-19 02:37 PM @rfs I've gotten lots of Chinese kf hardware. One case where a 1/4 adapter was just machined wrong, too small recess for the o-ring thing. Also one bad weld, visible light thru. But on eBay vendors eager to avoid bad review, happy to ship you another. 03-Mar-19 02:39 PM Ok 03-Mar-19 02:39 PM And if the parts are reasonably cheap they vendors hopefully wont fight it that much 03-Mar-19 02:43 PM @Conmega I have one like that, American made under license. Oil was super gunky, rust on the discharge value post, like that. After using a gallon of flushing fluid it cleaned up fine, pulls vacuum down in the single digit microns. I found manual online. Suggests pouring fluid directly into intake for severe gunk. The siding part might be one of the check valves or anti suck-back valve, etc. Possibly not a problem. 03-Mar-19 04:01 PM @robamacl cool thanks for the info! I learned that the Alcatel 2008AC model that I have is rated for corrosive gases which is fun :P The 2008A model wouldn't be rated for corrosive. It runs well, seems to pull good vacuum, its just... loud... which probably means its a bit worn out... Could need some more flushing, not sure. I'll probably use it for some basic vacuum work for now but until I get my centering ring and clamp for KF16 I won't be-able to hook up my vacuum gauge and find out how it pulls for vacuum 03-Mar-19 07:24 PM Joined the server. 04-Mar-19 12:02 AM moin 04-Mar-19 01:05 AM Gloin! \o/ 04-Mar-19 01:21 AM moin! 04-Mar-19 10:02 AM https://www.youtube.com/watch?v=IrtGp8hv-0Y something like that @N00N @Nixie 04-Mar-19 10:02 AM Saw it long time ago, I'm a great fan of Tom Scott. 04-Mar-19 10:22 AM moin! 04-Mar-19 12:45 PM Joined the server. 04-Mar-19 07:57 PM what methods of detecting angles do y'all know? advanced techniques welcomed 04-Mar-19 10:36 PM So yea, going to try an experiment... My EDS detector is borked for my SEM, someone smashed the Be window in on the front... mmm Beryllium, so yea if I can get a new window for it I need to pump the inside of the detector back down through a 1.33" conflat to copper pinch off. 04-Mar-19 10:36 PM So for a pinch off tool for cold weld I am going to try and use one of these modified to have two steel rods in it for a pinch off tool 04-Mar-19 10:36 PM https://www.ebay.com/itm/10-Ton-Hydraulic-Cable-Crimper-9-Dies-Carrying-Case-Professional-Grade-Tool/302354325132 04-Mar-19 11:22 PM Woah. 05-Mar-19 12:07 AM Wait...is it 10 Ton, or 16 Ton? is it metric or imperial? 05-Mar-19 12:07 AM XDDDDD 05-Mar-19 12:36 AM Moin! 05-Mar-19 01:16 AM Murican I'm sure 05-Mar-19 01:16 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1703-0D1D2.jpg 05-Mar-19 01:16 AM Got the PSU for the turbo sorted tonight. 60V supply adjusted down to 50V. Turbo needs 24-59VDC. Figured I'd play it safe at 50V 05-Mar-19 01:16 AM Still need an ISO 160 to conflat anything adapter 05-Mar-19 01:39 AM You'll find it easily enough in US 05-Mar-19 01:39 AM could not find anything on eBay.com 05-Mar-19 01:39 AM but my search voodoo is a bit weak atm 05-Mar-19 01:39 AM If you were in germany on the other hand... :P 05-Mar-19 01:39 AM http://www.vacom-shop.de/epages/VacomShop.mobile/en_US/?ViewObjectID=1089587 05-Mar-19 01:42 AM That's a bit expensive 05-Mar-19 01:42 AM welcome to new, cleanroom grade vacuum hardware 05-Mar-19 01:52 AM I don't understand your words. 05-Mar-19 01:52 AM 05-Mar-19 01:52 AM They have no meaning and are dimensionless. 05-Mar-19 01:52 AM https://tenor.com/view/confused-what-wut-lol-huh-gif-4124713 05-Mar-19 11:27 AM @GigaSquirrel actually thats cheaper than lds vacuum 05-Mar-19 11:27 AM I was considering buying brand new, and thats like 100-200 dollars cheaper than what I was looking at 05-Mar-19 11:27 AM er, thats 100 ISO to 160 Conflat? 05-Mar-19 11:27 AM so ISO 100 to 8" conflat it seems like 05-Mar-19 11:30 AM whoops, yes 05-Mar-19 11:30 AM but look around at vacom, I'm sure they got the right one somewhere 05-Mar-19 11:32 AM yup! 05-Mar-19 11:32 AM http://www.vacom-shop.de/epages/VacomShop.mobile/en_US/?ObjectPath=/Shops/Store.VacomShop/Products/303933 05-Mar-19 11:32 AM 6" conflat to ISO 160, out of stock ofcourse... 05-Mar-19 11:32 AM http://www.vacom-shop.de/epages/VacomShop.mobile/en_US/?ObjectPath=/Shops/Store.VacomShop/Products/302468 05-Mar-19 11:32 AM then 8" conflat to ISO 160 05-Mar-19 11:32 AM which they do stock, 350 dollars though, weeww 05-Mar-19 11:32 AM still going to keep an eye on the ePay... I've been hunting one for a few months now though with nothing showing up so I'll probably be forced to buy new 05-Mar-19 11:36 AM contact them, explain your situation, maybe show them some of the stuff you've done / the talks you've held 05-Mar-19 11:36 AM they told me they like supporting students 05-Mar-19 11:42 AM oh cool ok! I may give that a shot. I am kinda a student too, well I should be back to college in the fall anyway 05-Mar-19 11:45 AM good enough 05-Mar-19 11:54 AM https://i.ebayimg.com/images/g/UGMAAOSws7Fcfqpu/s-l1600.jpg 05-Mar-19 11:54 AM drool 05-Mar-19 11:54 AM 1600 l/s ISO 250 05-Mar-19 11:54 AM freaking KF40 roughing flange 05-Mar-19 11:56 AM think we've got one of these lying around... 05-Mar-19 11:56 AM Pfeiffer something? 05-Mar-19 11:57 AM Varian V-2K-G 05-Mar-19 11:57 AM https://i.ebayimg.com/images/g/730AAOSwpLxcewdF/s-l1600.jpg 05-Mar-19 11:57 AM it has a built in power supply and controller <3 05-Mar-19 11:57 AM just takes 120V in 05-Mar-19 11:57 AM just yes, all my yes 05-Mar-19 11:59 AM oh, ok 05-Mar-19 11:59 AM that's quite a bit better 05-Mar-19 11:59 AM go get it! 05-Mar-19 12:00 PM except for the 120V part... 05-Mar-19 12:00 PM well it could be 240V for all I know 05-Mar-19 12:00 PM yeah, well... can't have everything 05-Mar-19 12:00 PM I haven't checked the docs 05-Mar-19 12:00 PM but remember 120V is the standard outlet over here :P 05-Mar-19 12:00 PM also, the guy is going to send me a video of the blades spinning, if it looks decent I'll go for it 05-Mar-19 12:00 PM hopefully can get it cheaper than I got my current 690 l/s pump heh... 05-Mar-19 12:01 PM ...a country where you have things like high leg delta... and occasional rotting grounds which lift whole houses to hogh voltage potential... 05-Mar-19 12:05 PM oh I was going to say, I am having a hard time finding an ISO 160 to conflat adapter, can't imagine ISO 250... and I realized I already have an ISO 250 to CF 10" adapter sitting on the shelf... :) 05-Mar-19 12:13 PM ROFL 05-Mar-19 12:16 PM And I can get 10" to 8" on ePay all day long. 05-Mar-19 12:18 PM Yeah, just ebay-shame southerners. 05-Mar-19 12:18 PM the fun part about that turbo would be getting a roughing pump to back it 05-Mar-19 12:18 PM XDDDD 05-Mar-19 12:18 PM Hum...would it? I mean, once you have evacuated good enough, won't just work the same? 05-Mar-19 12:20 PM i have this damn Iso320 valve... 05-Mar-19 12:20 PM lol, i sent this ~10 minutes ago Oo 05-Mar-19 12:20 PM hello internet. 05-Mar-19 12:20 PM I have an edwards RV12... which is like a good pump... nearly 17 m3/h, that turbo recommends 40 m3/h... 05-Mar-19 12:20 PM o/ 05-Mar-19 12:20 PM lol 05-Mar-19 12:20 PM only a little late, but wow an ISO 320 valve? 05-Mar-19 12:20 PM I'd love to see a photo of that haha 05-Mar-19 12:20 PM thats like a loadlock for a small child XD 05-Mar-19 12:22 PM uhm, give me a second 05-Mar-19 12:22 PM @GigaSquirrel pictures, please! 05-Mar-19 12:22 PM no rush lol, this is the internet 05-Mar-19 12:22 PM oh, haha I guess Giga has it on hand XD 05-Mar-19 12:22 PM german internet 05-Mar-19 12:22 PM ah right, you CANT rush haha 05-Mar-19 12:22 PM uhg, I can't find my other hornet ion gauge... I know I bought two... one just like evaporated in my house somehow 05-Mar-19 12:23 PM he made the pictures, so i guess he can post 'em here 05-Mar-19 12:23 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180317_103122-06D69.jpg 05-Mar-19 12:23 PM sigh sometimes I wonder if I have too much stuff 05-Mar-19 12:24 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180317_120958-59C73.jpg 05-Mar-19 12:24 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180317_120934-A44EB.jpg 05-Mar-19 12:24 PM @Conmega yes, you do. as we all do. and it's good that way. 05-Mar-19 12:24 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180317_120915-F884C.jpg 05-Mar-19 12:24 PM heh... guess they used it for throttling LOL 05-Mar-19 12:24 PM but just wow 05-Mar-19 12:24 PM yes, that's what it is meant for according to VAT 05-Mar-19 12:24 PM yeah, it acutally is something like a 3200 l/s throttle valve 05-Mar-19 12:24 PM heck of a valve 05-Mar-19 12:24 PM ah ok 05-Mar-19 12:24 PM so its not a gating mechinism? 05-Mar-19 12:24 PM like where it clamps shut? 05-Mar-19 12:25 PM it does so at the end 05-Mar-19 12:25 PM oh ok thats nice then 05-Mar-19 12:25 PM so its electric drive for fine control with throttling and a gate 05-Mar-19 12:25 PM thats really cool 05-Mar-19 12:25 PM aye 05-Mar-19 12:25 PM now you just need a lathe to adapt it down to KF25 to use it :) 05-Mar-19 12:26 PM that is EXACTLY my problem 05-Mar-19 12:26 PM XD 05-Mar-19 12:26 PM or just get bigger pumps 05-Mar-19 12:26 PM like me :) 05-Mar-19 12:26 PM uhg the fun part will be finding more big conflat bits to build my chamber out with or make more chambers 05-Mar-19 12:27 PM bigger pumps? my rotary vane pump needs 3phase... 05-Mar-19 12:27 PM ohhh, so you have a nice roughing pump 05-Mar-19 12:27 PM now find an ISO 320 turbo that spins at like 30K RPM 05-Mar-19 12:27 PM shouldn't be terrifying at all :) 05-Mar-19 12:27 PM that ISO 250 one spins at 33K RPM 05-Mar-19 12:27 PM could not imagine the sound it makes 05-Mar-19 12:28 PM i'm currently in contact with VAT to get some replacement parts for the valve... damn, they're cheaper than i thought. except for the sealing kit... those rubber rings are f*** expensive... 05-Mar-19 12:28 PM heh... 05-Mar-19 12:28 PM yea it seems to be that way with companies 05-Mar-19 12:28 PM your either amazed by the prices or flabbergasted 05-Mar-19 12:28 PM for rebuild bits anyway 05-Mar-19 12:29 PM yeah, well, our biggest turbo is CF... 260 or so. 05-Mar-19 12:29 PM like roughing pumps... uhg... 200-300 bucks a pump yay 05-Mar-19 12:30 PM i got that 3phase pump for free... "doesn't spin anymore, we'll just throw it out. take it if you want" 05-Mar-19 12:30 PM I have 3 roughing pumps, one that I need to try and make a new main seal for, one that needs a rebuild but "works" and my RV12 that seems decent 05-Mar-19 12:30 PM ohhh nice 05-Mar-19 12:30 PM you guys get good free stuff 05-Mar-19 12:30 PM i then scooped the alu shavings out of the first stage, ground the vanes back in shape and it ran great (oh, and i bought custom o-rings for 200 euros. XD ) 05-Mar-19 12:31 PM I've spent quite a bit of money for all my stuff uhg, like its available more readily here but even if its complete scrap they want cash. 05-Mar-19 12:31 PM nice! 05-Mar-19 12:31 PM yeah, i paid too much, too, but sometimes i were in the right place at the right time 05-Mar-19 12:32 PM actually, how does that work, grounding vanes back into shape that is, is that a common practice for a partial rebuild on a pump with not a ton of hours, or is that only on larger pumps? smaller pumps the vanes are more disposable I'd assume. 05-Mar-19 12:32 PM because it would be cool to get away with a rebuild kit without the vanes in it, since they are ussually the expensive part of the kit 05-Mar-19 12:32 PM like you can get the gasket/orings for a rebuild for like half the cost or less even usually 05-Mar-19 12:32 PM maybe I'll give that a try on the Alcatel 2008AC I have hrm 05-Mar-19 12:32 PM yea $115 vs $250 05-Mar-19 12:34 PM in this case - i was young, i had the time, and no idea how and where to get replacement vanes. 05-Mar-19 12:34 PM and they were shot anyways and the pump was free, so i guessed i might just try it :-D 05-Mar-19 12:34 PM I mean, I'd assume re-honing the vanes multiple times is a bad idea... but once per set of vanes? I'd assume you could probably get away with it if they aren't too chewed up 05-Mar-19 12:34 PM its not like we are running a production line on these things, we just use them every now and then 05-Mar-19 12:34 PM probably save us hobbiests quite a bit of cash 05-Mar-19 12:34 PM the fun concern about my Alcatel 2008AC though is that the C in the model stands for corrosive :) It can withstand corrosive gases... meaning its a bit special... and it has some interesting pitting on the outlet KF haha 05-Mar-19 12:36 PM maybe just turning them around helps? as i guess they're unevenly abraded 05-Mar-19 12:36 PM hrm... I've never been inside a rotary pump but I thought they would wear pretty evenly 05-Mar-19 12:38 PM since the axis of rotation is offset from the axis of the stators, they might not wear evenly... less on the suction side, more on the pressure side maybe 05-Mar-19 12:38 PM just a thought, haven't paid attention on that detail in the past 05-Mar-19 12:39 PM ah ok 05-Mar-19 12:39 PM disassembled 3 or 4 pumps but never thought of that 05-Mar-19 12:39 PM it'll be worth the experiments 05-Mar-19 12:40 PM well, i have 2 "new" ones to undergo full rebuild, so i'll try and experiment in that direction ^^ 05-Mar-19 12:40 PM oh, and my big one is an alcatel 2030, so the big big brother of your 2008 :-D 05-Mar-19 12:47 PM oh neat! 05-Mar-19 12:52 PM Conmega, ever heard of knife valves for KF25? 05-Mar-19 12:53 PM erm I suppose but I can't picture one in my head atm 05-Mar-19 12:53 PM I wish I could have gotten the pumps from the surplus place... they wanted a lot per though... well not a lot for this pump but a lot for me on the spot... 05-Mar-19 12:53 PM https://i.imgur.com/VSL31Tm.jpg 05-Mar-19 12:53 PM they wanted like 750 bucks... 05-Mar-19 12:54 PM @Nixie https://www.ebay.de/itm/333046719173 05-Mar-19 12:54 PM if they still have one I might consider it in the future but man 05-Mar-19 12:54 PM Nice! 05-Mar-19 12:54 PM Should consider getting one and building a feeding port for the e-beam thing if it works 05-Mar-19 12:57 PM could you use a ball valve for that? 05-Mar-19 12:57 PM i mean it both gives you a direct pass through the valve when open and a seal when closed... 05-Mar-19 12:58 PM does it seal good enough? 05-Mar-19 12:58 PM it's an electron beam after all 05-Mar-19 12:59 PM @GigaSquirrel has one on his chamber (or two) and they're good until e-8mbar 05-Mar-19 01:00 PM ah 05-Mar-19 01:00 PM Will have to give a thought then. 05-Mar-19 01:05 PM give me a minute 05-Mar-19 01:13 PM @Pan Da your time is over. 05-Mar-19 01:14 PM @Nixie https://www.ebay.de/itm/SF-1-4408-G-1-2-2-Wege-Kugelhahn-Absperrhahn-Hahn-Ventil-1-2-Zoll/163350315768?hash=item26087002f8:g:izoAAOSwfONb2~NQ 05-Mar-19 01:14 PM we have those, got them with KF16 preinstalled. maybe @GigaSquirrel has the link to those, i can't find them 05-Mar-19 01:14 PM https://www.ebay.de/itm/EA-1-4408-DN15-PN64-Kugelhahn-mit-Betatigungssperre-Edelstahl-14-mm-Valve-Vakuum/143003160768 05-Mar-19 01:14 PM this one seems to have KF, but not sure 05-Mar-19 01:37 PM there are of-course these guys for a bit more 05-Mar-19 01:37 PM https://www.ebay.com/itm/new-VAT-valves-series-265-KF16-vacuum-normally-open-valve-qty-available-mks-AMAT/263035830144 05-Mar-19 01:37 PM they've been up for quite awhile now actually 05-Mar-19 01:37 PM probably take lower offers 05-Mar-19 01:44 PM Oh! 05-Mar-19 01:44 PM the valve seems pretty affordable 05-Mar-19 01:44 PM yea remember those? 05-Mar-19 01:44 PM I shared those with you like 05-Mar-19 01:44 PM a year ago 05-Mar-19 01:44 PM :P 05-Mar-19 01:44 PM (the other ball valve) 05-Mar-19 01:44 PM ah I see 05-Mar-19 01:44 PM I know the pneumatic one by heart 05-Mar-19 01:44 PM XDDD 05-Mar-19 01:45 PM I mean, the VAT valve, after making a 20 dollar offer on it, is like 7 bucks more 05-Mar-19 01:45 PM Yes, but it's true inline 05-Mar-19 01:45 PM the other one, not so much 05-Mar-19 01:45 PM might be usable 05-Mar-19 01:45 PM but right now my eyes are closing by themselves 05-Mar-19 01:45 PM and in any case, I can't afford anything other than your shipping 05-Mar-19 10:41 PM Morning! \o/ 06-Mar-19 12:53 AM Moin! 06-Mar-19 06:12 AM Joined the server. 06-Mar-19 06:15 AM Joined the server. 06-Mar-19 06:16 AM Welcome, new people! 06-Mar-19 06:17 AM ✌ 06-Mar-19 07:17 AM Ohaio, soon to not-be-strangers! 06-Mar-19 11:11 AM https://www.ebay.com/itm/MDC-VACUUM-PRODUCTS-DOUBLE-ENDED-7052-GLASS-ADPT-NW50-PART-NO-462023-NEW/223431133967 06-Mar-19 11:11 AM this is a cute weird little piece 06-Mar-19 11:47 AM Hrmmmm I think I might buy two helium compressors with like less than 10 hours on each this Friday... 06-Mar-19 11:47 AM I think I need some cryo capability :) 06-Mar-19 12:37 PM XD 06-Mar-19 12:37 PM Go, go, go! 06-Mar-19 11:17 PM Those ends are probably invar and cost a fortune (even before adding the glass) So nice! 06-Mar-19 11:17 PM Damn the price is good...cries a bit 06-Mar-19 11:32 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1708-33D86.jpg 06-Mar-19 11:32 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1706-B6022.jpg 06-Mar-19 11:32 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1709-5E34F.jpg 06-Mar-19 11:32 PM I'll just leave this here. Someone has to post some vacuum bits from time to time. 06-Mar-19 11:32 PM :) 06-Mar-19 11:46 PM Oh yeah...keep removing layers, baby! 06-Mar-19 11:46 PM but you can keep your hat on... 07-Mar-19 12:43 AM Moin! 07-Mar-19 01:16 AM Coin! \o/ 07-Mar-19 02:54 AM whoohoo, I got mail! 07-Mar-19 02:54 AM gaskets for the TMP and the heating wire for my oven \o/ 07-Mar-19 03:12 AM Nice! 07-Mar-19 03:21 AM hmm, but my table is a bit too narrow 07-Mar-19 03:21 AM => no place for the pump to stand 07-Mar-19 03:21 AM and I don't want the valve to hold it, that worked with the small DP, but might be an issue with a 3+ kg TMP... 07-Mar-19 03:26 AM Just start it and never stop it, the gyroscopic effect will keep it upright. 07-Mar-19 03:27 AM xD 07-Mar-19 03:27 AM upright is not an issue 07-Mar-19 03:27 AM but 07-Mar-19 03:27 AM one sec 07-Mar-19 03:27 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190307_122743-81D01.jpg 07-Mar-19 03:27 AM those two KF40 have to mate 07-Mar-19 03:39 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190307_123932-21966.jpg 07-Mar-19 03:39 AM hmmmm 07-Mar-19 03:39 AM but I don't really trust my welds holding the chamber 07-Mar-19 03:39 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190307_124331-670CF.jpg 07-Mar-19 03:39 AM cough cough professional solution! 07-Mar-19 04:17 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190307_131143-1D4DB.jpg 07-Mar-19 04:17 AM time for some leak checking! 07-Mar-19 04:48 AM LMAO 07-Mar-19 04:48 AM what is the aluminium tape in the top auge and right connector for? 07-Mar-19 04:49 AM to make the chamber light tight 07-Mar-19 04:49 AM How to: leak check 07-Mar-19 05:05 AM XDDD 07-Mar-19 05:05 AM The gentle tap is to ensure everything is bolted? 07-Mar-19 05:06 AM yep, that was totally planned! 07-Mar-19 05:35 AM no leaks found 07-Mar-19 05:35 AM currently pumping down 07-Mar-19 06:37 AM but then https://www.youtube.com/watch?v=a9WT8MuMGpw 07-Mar-19 06:37 AM (this sound) 07-Mar-19 06:37 AM cries out loud in pain 07-Mar-19 06:40 AM yeah 07-Mar-19 06:56 AM I need to get new oil for mine, I guess some hydrocarbon diff pump oil will do 07-Mar-19 07:28 AM That's a dead bearing, right? 07-Mar-19 07:32 AM in the TMP video? 07-Mar-19 07:32 AM yes 07-Mar-19 07:32 AM and the chamber is in the upper e-6 range, woohoo! 07-Mar-19 08:19 AM https://tenor.com/view/despicable-me-minions-funny-lol-gif-3410946 07-Mar-19 10:09 AM @GigaSquirrel how are you leak checking with the helium before you pumped down? 07-Mar-19 10:09 AM I thought the point is to get your chamber to its ultimate pressure then leak check with helium and a detector off your chamber, a detector like a RGA or a specific helium leak check too 07-Mar-19 10:40 AM the way I did it I can only check for mayor leaks, that's true 07-Mar-19 10:40 AM like the ones that would limit me to e-3 to e-4 07-Mar-19 10:40 AM right now I'm pumping down as far as it will go to properly leak check it 07-Mar-19 10:40 AM currently at 4.3e-6 07-Mar-19 10:40 AM only two more orders of magnitude to break my record xD 07-Mar-19 10:40 AM might even bake it on the weekend 07-Mar-19 10:46 AM Niiiiice 07-Mar-19 10:48 AM wanna see how low I can get with the turbo 07-Mar-19 10:48 AM but I'm afraid I'm limited by everything being rubber sealed 07-Mar-19 10:48 AM all ISO / KF 07-Mar-19 10:51 AM Eh I mean I think you'll ultimately be limited by the turbo itself and the way your attached to your big chamber 07-Mar-19 10:51 AM remember, the more bends and smaller openings from your main chamber to your pump gives less efficiency because the chance for a floating particle to bounce down through to the turbo is lower... 07-Mar-19 10:51 AM I mean your setup isn't too bad all things considering, just a general note though 07-Mar-19 10:51 AM Remember, most SEMs and such are sealed completely with orings 07-Mar-19 10:53 AM nah, the turbo's rated to e-10 and it got the chamber to e-8 with my old 40 l/s DP at the same spot 07-Mar-19 10:53 AM I don't think my massive SEM has a single metal/metal seal 07-Mar-19 10:53 AM how far down does your SEM go? 07-Mar-19 10:54 AM the darn Ion gauge doesn't work and I think I have a minor leak somewhere so I'm not sure 07-Mar-19 10:54 AM just use a hornet 07-Mar-19 10:55 AM yea waiting for a controller :P 07-Mar-19 10:55 AM also remember, outgassing is a big thing 07-Mar-19 10:55 AM you have to be pumping for a few days to really get most of your outgassing to go away 07-Mar-19 10:55 AM I know my SEM I had to run for hours mutliple days to get the outgassing to slow down 07-Mar-19 10:55 AM let alone to get it to go away completely I dunno if that will really happen 07-Mar-19 10:56 AM nope, that'll never happen 07-Mar-19 10:56 AM once you've gotten rid of all the "volatiles" in your vacuum you'll see hydrogen diffusing through your walls 07-Mar-19 10:57 AM I thought e-7 was like what you'd get max with like any general diffusion/turbo and if you wanted lower you'd need cryo or something. 07-Mar-19 10:57 AM maybe it was more like e-8/9 07-Mar-19 10:57 AM but yea... I know at some point turbos/diff pumps aren't really going to get you any further 07-Mar-19 10:59 AM not really, e-7 / 8 is the limit for non metal seals, with pure metal to metal to metal you can get way lower with just a TMP / DP (if properly baffeled) 07-Mar-19 10:59 AM hopefully getting some helium compressors tomorrow so I can end up playing with cryo 07-Mar-19 10:59 AM well so, thats the limit, if you don't have enough pumping capacity right? 07-Mar-19 10:59 AM it seems like even the largest/best turbos come with freaking ISO 07-Mar-19 11:00 AM but at those kinds of pressures your couple of 100 l/s from a tmp aren't that much, that's why you want 1000s l/s from a cryo / ion getter 07-Mar-19 11:00 AM instead of CF 07-Mar-19 11:00 AM right, I currently have a 690 l/s turbo and might be getting a 1600 l/s turbo... 07-Mar-19 11:00 AM and with two massive helium compressors I can run some big cryo heads 07-Mar-19 11:00 AM I should be-able to do.... whatever... 07-Mar-19 11:00 AM lol 07-Mar-19 11:01 AM that's a bit... massive 07-Mar-19 11:01 AM not that I need it... but science! 07-Mar-19 11:01 AM good luck on the compressor! 07-Mar-19 11:02 AM they are both like... new... they have 10 hours on each of them I think 07-Mar-19 11:02 AM its from the surplus place 07-Mar-19 11:02 AM they got them surplus and kinda just want them gone and they are asking nothing for them almost 07-Mar-19 11:02 AM like 250 a pop is what he last told me 07-Mar-19 11:02 AM which for basically new compressors... 07-Mar-19 11:02 AM is nothing 07-Mar-19 11:02 AM ah, those two you weren't sure about the first time(s) you went there? 07-Mar-19 11:02 AM well I was sure I wanted them 07-Mar-19 11:02 AM I just didn't have the space/money at the time 07-Mar-19 11:02 AM I've organized the basement a bunch since then 07-Mar-19 11:02 AM and I kinda still don't have money, but I'm going to make a bulk purchase and see if I can't get him down to 200 a piece 07-Mar-19 11:03 AM awesome! 07-Mar-19 11:10 AM I mean these are pretty big compressors too. I probably don't really need two, but I am going to get both because I can probably cut a deal and if anyone wants to pay me what I payed to own one someday I'd probably be fine to do that 07-Mar-19 11:10 AM or I'll just delegate one to LN2 generation because yay running up the hours on a compressor for no good reason but to freeze things. 07-Mar-19 11:13 AM having LN2 is always great 07-Mar-19 11:14 AM or LOX 07-Mar-19 11:14 AM :) 07-Mar-19 11:15 AM that's a whole different kind of fun 07-Mar-19 11:17 AM nice thing is oxygen generators are cheap 07-Mar-19 11:17 AM not much capacity, but you don't need much for LOX generation I'd imagine 07-Mar-19 11:17 AM it's suprising that filtering oxygen out of air is cheaper than nitrogen 07-Mar-19 11:18 AM right? I had a theory about that though 07-Mar-19 11:18 AM so the oxygen generators right? 07-Mar-19 11:18 AM their exhaust is the 80% of nitrogen and other stuff that is in air right? 07-Mar-19 11:18 AM the issue you run into with that is the CO2 07-Mar-19 11:18 AM most of the other stuff in air like argon and such probably don't liquify at the same temp as LN2 07-Mar-19 11:18 AM so honestly 07-Mar-19 11:18 AM I thought about that as well 07-Mar-19 11:19 AM ahh, fair point 07-Mar-19 11:19 AM they don't make molecular sieves for N2? 07-Mar-19 11:19 AM that you could run the output of an O2 concentrator through? 07-Mar-19 11:19 AM I basically have a linde machine and the issue is the CO2 freezing in it 07-Mar-19 11:19 AM hrm 07-Mar-19 11:20 AM there are membranes for N2 07-Mar-19 11:20 AM however they are not cheap 07-Mar-19 11:20 AM ah darn 07-Mar-19 11:20 AM I'm really curious how the hosing for the helium compressor works... 07-Mar-19 11:20 AM like the connections... 07-Mar-19 11:20 AM https://i.ebayimg.com/images/g/tX0AAOSwmOJaQ3sW/s-l500.jpg 07-Mar-19 11:20 AM these things 07-Mar-19 11:20 AM like being that its helium those must be some pretty darn fancy connectors 07-Mar-19 11:22 AM they are 07-Mar-19 11:22 AM which makes them extremely expensive 07-Mar-19 11:24 AM yea I noticed... even used they are like 200 bucks for a set 07-Mar-19 11:24 AM they seem super standardized though 07-Mar-19 11:24 AM like there is ONLY this style of connector/cable for all the cryo pumps 07-Mar-19 11:25 AM pretty much, yep 07-Mar-19 11:25 AM I've seen cryo heads all over ePay for like 70~ bucks or so though 07-Mar-19 11:25 AM last I saw them 07-Mar-19 11:25 AM so luckily those are cheap :) 07-Mar-19 11:28 AM mumbles angrily something about ebay in the usa 07-Mar-19 11:28 AM if they are not worn out, that's a fair price 07-Mar-19 11:28 AM the helium connectors are not really fancy, they are a drybreak design that is very common in a few industries 07-Mar-19 11:37 AM doesn't appear to be any that cheap atm tho hrm 07-Mar-19 11:37 AM @Applied_Ion you need to come over someday 07-Mar-19 11:37 AM like this weekend maybe. I have tomorrow off from work and I'm going to have another friend over anyway 07-Mar-19 11:37 AM your welcome by anytime, we can dis-mount that sputter head and you can get your 6" conflat T 07-Mar-19 11:37 AM even though I may have realized how useful it might be... I know you have a mighty need for it and I want to see your project going :) 07-Mar-19 11:37 AM man I really want to spin up my turbo, the annoying thing is, a conflat 8" with the copper ring still stuck to it, the ID of the copper ring is like JUST BARELY TOO SMALL to go over the centering ring of ISO160... 07-Mar-19 11:37 AM it would have been awesome to just throw one of the 8" viewports I have over the turbo and see if I can rough it down 07-Mar-19 11:37 AM I mean I could probably file the copper ring open just a bit... and bodge something... 07-Mar-19 02:28 PM By file, you mean lathe right? () 07-Mar-19 02:28 PM I mean, won't the huge increase i surface from the filing scratches mess with the vacuum? 07-Mar-19 03:14 PM This is on the ID of the ring not the sealing surface but also this is a bodge not a proper thing. 07-Mar-19 03:14 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1710-47855.jpg 07-Mar-19 03:14 PM Also mail time 07-Mar-19 03:15 PM damn it, I only got ISO gaskets in the mail 07-Mar-19 03:20 PM @Conmega yeah that would be great! I think I can make it down this weekend, probably on saturday, I'll let you know 07-Mar-19 03:22 PM The turbos I might have access to are like ISO 100. So I’m thinking ISO 100 conical adapter down to CF 3.38 and then a zero length reducer from CF3.38 to CF2.75 and then a CF2.75 butterfly valve into the chamber (CF2.75 cross). 07-Mar-19 03:22 PM Does that sound like the best approach? 07-Mar-19 03:26 PM yep, sounds great 07-Mar-19 03:27 PM It seems ridiculous but tiny turbos are rare and less efficient presumably 07-Mar-19 03:27 PM how do you define efficiency? 07-Mar-19 03:27 PM like just by raw input power? 07-Mar-19 03:30 PM Well we could just define efficiency as “two nearly brand new Agilent turbos in known intact condition with controllers sitting there unused in our lab and if I ask my supervisor nicely I can maybe score one” which I think will be high efficiency ^_^ 07-Mar-19 03:31 PM oh, that kind of efficiency 07-Mar-19 03:33 PM And bigger throat should work better right? But it makes no difference on a 2.75 chamber 07-Mar-19 03:33 PM Mmm 07-Mar-19 03:33 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-C7C55.jpg 07-Mar-19 03:35 PM with a setup that small the diameter won't really limit you 07-Mar-19 03:35 PM like down to e-7 / 8 is no issue, if your parts are clean 07-Mar-19 03:35 PM you young people and your modern day TMPs... 07-Mar-19 03:35 PM xD 07-Mar-19 03:39 PM I have access to an enormous diff pump... big and heavy, probably full of dust and spiders, probably takes gallons of expensive oil, and they’re just so bulky and heat up the room. 07-Mar-19 03:39 PM So yes I like millennial turbos 07-Mar-19 03:42 PM nice 07-Mar-19 04:29 PM What's a tiny turbo? The one's at work are approx 1liter beercan size 07-Mar-19 04:48 PM 1 litre beer can? That seems massive and you would think that would be an Australia thing but it’s not 07-Mar-19 04:57 PM It was relatively briefly a thing 07-Mar-19 04:57 PM I think it was a partial protest to alcohol regulations. As it was ruled that a beercan could not be cheaper when bought in bulk. 07-Mar-19 04:57 PM They are rarely available thesedays because you really need to slam that can to drink it before it gets all warm and stale. 07-Mar-19 05:20 PM A 2.75 CF 4 way cross seems like a tiny vessel. But apparently that’s what all the cool fusor kids are using these days. 07-Mar-19 05:37 PM 2.75" hardware is tight, but enough if you know what to do with it. I designed a 5 way 2.75" cross chamber to eventually doing scaled experiments of the EXEDA system. Probably can get away with transporting a couple hundred amp beams in that size. In my opinion, fusors are too limited, not that much you can do with them. I may be biased, but beams is where the fun is at. 07-Mar-19 05:56 PM Is there any good well documented, photographed example of a 2.75 fusor out there? 07-Mar-19 05:57 PM Several in the fusor community on the fusor forums 07-Mar-19 05:57 PM It's becoming more popular due to cost 07-Mar-19 05:57 PM Also for the power you can put in, they can yield relatively decent neutron counts. Less deuterium required than larger systems 07-Mar-19 05:57 PM You are limited in ultimate voltage though due to tight dimensions 07-Mar-19 05:57 PM It's unfortunate no one in the fusor community is looking to do pulsed fusors. Actually there haven't been any amateur pulsed fusor efforts. It's too bad, since you can get higher peak yields for less power input, and scale to far higher voltages and currents than any dc system. 07-Mar-19 06:25 PM Hard to do pulsed neutron counting? 07-Mar-19 06:30 PM You can still use bubble dosimeters. Activation is also a viable method. 07-Mar-19 08:27 PM I don't pop in here too often, but I just realized something that may be of use to y'all 07-Mar-19 08:27 PM Chinese electrodeless fluorescent lamps, and their ballasts, are readily available on eBay and AliExpress 07-Mar-19 08:27 PM seems like if you need 150 watts of RF power at 2.65 mhz, that might be a way to go 07-Mar-19 08:27 PM just add matching network 07-Mar-19 08:30 PM That is interesting 07-Mar-19 08:30 PM Got a link to an example? 07-Mar-19 08:31 PM https://www.ebay.com/itm/Universelite-UNL150-150-Watt-Electronic-Ballast-Electrodeless-110-277V/183696957581?hash=item2ac531208d:g:b40AAOSw44BYXzsf 07-Mar-19 08:31 PM 2.65mhz seems to be a very common frequency 07-Mar-19 08:32 PM Hmm, that Ain't too expensive at all 07-Mar-19 08:37 PM oh thats awesome to know! 07-Mar-19 08:37 PM i don't know it for sure, it is a hypothesis 07-Mar-19 08:45 PM It's a tempting price point to just buy one to tear apart 07-Mar-19 08:45 PM I'm also interested in general on the parts used and so on. And how hard it would be to convert it to a linear amplifier, or phase lock it to a more stable reference. 07-Mar-19 10:37 PM Morning! \o/ 08-Mar-19 12:30 AM @rfs pulsed neutron counting can be very hard, what kind of pulses are we talking about? 08-Mar-19 12:30 AM and how many neutrons? 08-Mar-19 12:30 AM and also: Moin! 08-Mar-19 12:31 AM Huh? 08-Mar-19 12:31 AM I was refering to that RF ballast thing 08-Mar-19 12:31 AM All of which selling on ebay with similar descriptions are in USA. 08-Mar-19 12:31 AM Unfortunately :/ 08-Mar-19 12:32 AM ah, sorry, mixed you up with @a_quiet_scientist , they asked that question 08-Mar-19 12:32 AM np 08-Mar-19 12:58 AM Do you think the RF ballast can be used to RF sputter? 08-Mar-19 12:59 AM should be possible 08-Mar-19 12:59 AM if you match it well 08-Mar-19 01:13 AM https://tenor.com/view/adventure-time-now-kiss-gif-5658105 08-Mar-19 01:15 AM A match made in heaven a matching network 08-Mar-19 01:15 AM XDDD 08-Mar-19 01:37 AM wonder if my dentron supertuner can match an RF sputtering chamber to my drake T-4XB 08-Mar-19 01:37 AM peak envelope power into a plasma 08-Mar-19 01:41 AM I'd suspect it could 08-Mar-19 01:41 AM and if not some additional components on the outside would not be that hard to add. 08-Mar-19 01:41 AM But good old tuners tune up anything. The USA example is usually a lawn chair, here it's a heteka bed. 08-Mar-19 01:41 AM I'm not that up on drakes, but if it has a vacuum tube final it should be quite robust, if you are not running it at it's absolute limits. 08-Mar-19 01:53 AM The problem I'd see in RF ballast sputter usage is that it's likely gona be free running, so the frequency is gona change depending on the load. And I have no idea how much, and the loading is gona change when the plasma ignites, I think. I'm not properly aware of that side of things. 08-Mar-19 02:35 AM Well, I might try in the long future, just for giggles. 08-Mar-19 02:35 AM As I'll be needing to sputter SiO2 to protect the silicon 08-Mar-19 02:36 AM If I could get a 150W unit for under 30eur shipped, I'd get one for tearing appart and possibly modding. 08-Mar-19 04:57 AM @GigaSquirrel I was the one who actually brought up pulsed sources, specifically referring to pulsed fusors. I don't believe pulsed neutron counting would be hard at all. Most people doing measurements on it for sources mainly care about average n/s rate still. For a fusor source, pulses are very wide and slow. 10s to 100 uS, at rep rates of 10s to 100s of hz, neutron fluxes probably on the order of 10^7 per sec minimum. The most common method I see is simple activation foil counting with something easy to activate lile silver. Bubble dosimeters can also be used - they don't care if the neutrons coming in are pulsed or continuous, and will give you the time averaged flux like a dc system. Even for single shot stuff like the DPF, the foil activation method is pretty common as long as fluxes are at appropriate levels. 08-Mar-19 05:06 AM The gear used for PECVD and DRIE and RF sputter etc is not super high tech - looks very similar to the sort of thing HF HAMs use for high power - big variable capacitors motorised with auto-tuners that measure the reflected power and automatically tune the knobs. 08-Mar-19 05:07 AM yes, activation is an easy way to detect neutrons, but it's hard to do quantitative analysis that way 08-Mar-19 05:07 AM bubble dosimeters are just tools for guesstimation imo 08-Mar-19 05:07 AM and for direct detectors like scintillators / He3 / B10 electrical noise can produce false detections 08-Mar-19 05:18 AM Ueah, I wouldn't use direct detectors for this. Bubble dosimeters are rough, but easy and foolproof to get order of magnitude measurements. I don't think in depth quantitative analysis is really necessary for tabletop electric neutron sources 08-Mar-19 05:19 AM not necessary, but that's the interesting part 08-Mar-19 05:19 AM Point is, I don't think detection should be an excuse to not pursue pulsed fusors lol, not any more difficult than dc ones 08-Mar-19 05:26 AM Yep! 08-Mar-19 11:39 AM @a_quiet_scientist Afther having used an ACOM 2000, I dont want to go back to "boring" manualy tuned PA's. Thing autotunes on any frequency between 1.8-30MHz and gives 1500W CW all day long 08-Mar-19 11:39 AM Seen it produce 3200W CW to a dummyload, but that's just abuse. 08-Mar-19 11:39 AM Just key up a bit and it autotunes the PA to the load ❤ 08-Mar-19 11:39 AM I do have an LDG 200PRO or something for personal use, but I still mostly just use the manual tuner. 08-Mar-19 02:14 PM yay, friday 08-Mar-19 02:14 PM may get to run a few baseline volumetric efficiency runs 08-Mar-19 02:14 PM maybe more of mass flow efficiency 08-Mar-19 02:14 PM since I will be weighing it.. just a simple density translation to turn it into volume though 08-Mar-19 03:07 PM Go, go, go! 08-Mar-19 04:51 PM I'm getting my name on a patent. Oh boy! 08-Mar-19 05:03 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1711-3A16D.jpg 08-Mar-19 05:03 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1713-91516.jpg 08-Mar-19 05:03 PM Helium compressors mmmm 08-Mar-19 05:03 PM 26 and 28 hours on each. Either rebuilt or new from Ebara in 1998 and has 200 psi of something in there. Hopefully helium 08-Mar-19 05:03 PM They were palletized at the surplus place so yea... 08-Mar-19 05:04 PM Lol you actually did it 08-Mar-19 05:18 PM anyone know anything about turbo sputter coaters? 08-Mar-19 05:19 PM Yup and got a few boxes of labware too 08-Mar-19 05:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1714-C596F.jpg 08-Mar-19 05:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1715-F6DB6.jpg 08-Mar-19 05:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1716-73EAA.jpg 08-Mar-19 05:22 PM @piGuy what specifically? 08-Mar-19 05:24 PM It seems like they can be used with oxidizing metals for targets which I find interesting, but I'm not exactly sure why the turbopump is needed 08-Mar-19 06:24 PM Clearly the proper way to find out what that one system is charged with is to inhale it and see how your voice sounds! 08-Mar-19 07:42 PM Joined the server. 08-Mar-19 08:56 PM I like labware.. I have barely unboxed any of my stuff until I finish house reno.. 08-Mar-19 08:56 PM I need to bring my lab scale up for weighing the fuel returned for the upcomming experiment 08-Mar-19 10:57 PM @piGuy cograts! Will you sjare what is it in the future? Also, turbo sputter coaters? 09-Mar-19 01:50 AM sputter coater evacuated by tmp? thats the most common sputter rig, i guess? 09-Mar-19 01:50 AM u need HV for sputtering (if its not gold) 09-Mar-19 01:50 AM right? 09-Mar-19 01:50 AM and how else could it be possible to make a "pure" atmosphere for the process? 09-Mar-19 01:54 AM moin! 09-Mar-19 01:57 AM moin 09-Mar-19 02:02 AM MOINSEN! 09-Mar-19 03:14 AM No, actually if you evacuate too much, there will be no gas left to actually generate the plasma for sputtering. (But thermal evaporation does require HV) 09-Mar-19 03:14 AM And the pure atmosphere can be just argon, for example. 09-Mar-19 03:14 AM Argonium is NOT a thing 09-Mar-19 03:16 AM wiki says it is 09-Mar-19 03:17 AM Wiki also talks about flat earthers. 09-Mar-19 03:17 AM sadly they also exist 09-Mar-19 03:17 AM But they are more common than Argonium. So... 09-Mar-19 04:28 AM well 09-Mar-19 04:28 AM you can't get a defined "argon atmosphere" without proper evacuation 09-Mar-19 04:28 AM since desorption is a thing 09-Mar-19 04:28 AM for sputtering you have to clean your chamber first and then make the defined atmosphere 09-Mar-19 04:28 AM you simply can't let your process gases flow forever 09-Mar-19 04:28 AM and it would take forever - literally 09-Mar-19 04:28 AM that's y normal sputter configurations have TMPs, or not? 09-Mar-19 04:28 AM and yeah, it's possible to sputter without cleaning the chamber, if you don't need a good coating, because u need it for SEM imaging, it's okay ... but for most other applications it would be not okay, right? 09-Mar-19 04:28 AM you will get a foamy conglomerate of reaction products mixed with the sputter material on the substrate 09-Mar-19 04:51 AM or what 09-Mar-19 05:01 AM Well reactive sputter is a thing, to make titanium nitride films and stuff, but I presume you just want straight up argon sputter 09-Mar-19 05:01 AM Our evaporator doesn’t have a turbo I think. It’s a huge CTI cryopump 09-Mar-19 05:01 AM Not sure what the sputter coaters have 09-Mar-19 05:01 AM Proposed basic fusor architecture in a 2.75 cross. Any comments or feedback on this? 09-Mar-19 05:01 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-4D1E5.jpg 09-Mar-19 05:07 AM looks okay? 09-Mar-19 05:07 AM what i wanted to say, it doesn't matter what you want to sputter, if you want to sputter it right, u need (U)HV first 09-Mar-19 05:07 AM and that's y every normal commercial sputter setup has TMPs? 09-Mar-19 05:07 AM and without a TMP it's not possible to reach HV in a practical manner? 09-Mar-19 05:13 AM I made a magnetic feedthough for that, so i can cover the sample until the sputter action has deposited the residues of leftover gases, and then uncover it for proper deposition. 09-Mar-19 05:14 AM you mean, u use a getter pump, right? 09-Mar-19 05:14 AM that's possible but highly inefficient, i guess 09-Mar-19 05:14 AM yea of course you can use your sputter setup for getter-pumping, but that's energy and time intensive and kinda not reliable 09-Mar-19 05:14 AM iirc the initial question was about TMPs for sputtering - only wanted to illustrate why it makes sense and everyone does it 09-Mar-19 05:14 AM you could also use diffusion pumps, but that's another PITA, since you need baffles to prevent the contamination of the chamber with the pumps oil, right? 09-Mar-19 06:11 AM Not a getter pump per se, but the actual material (copper or aluminium) gets reacted and diposited around, then the atmosphere is much cleaner. 09-Mar-19 06:11 AM But yes, I get the point on using the tmp for not doing that. 09-Mar-19 06:11 AM I just don't want to expose mine to that, as it would get sputter material on it bcause of my chamber configuration. 09-Mar-19 06:21 AM yeah 09-Mar-19 10:45 AM Joined the server. 09-Mar-19 11:02 AM Welcome! 09-Mar-19 11:03 AM @Nixie , the patent is not HV related or anything. It has to do with controlling fluid flow in disposable diagnostic devices. 09-Mar-19 11:05 AM Doesn't matter if it's not HV related, it's awesome nonetheless. Congrats! 09-Mar-19 11:05 AM I would like to read it once avaliable. 09-Mar-19 11:10 AM Although I invented it, I can barely understand what the patent lawyers wrote. 09-Mar-19 11:14 AM XDDD, but I can look at the drawings, and fluid control is always interesting. 09-Mar-19 12:15 PM First finding on the flow bench thus far... running baselines 600rpm.. it appears the fuel output is 400ml, not the expected 600ml.. and I hgihly doubt it is 66% efficient at near no speed... so I think literature was wrong about the specs of 0.5cc/stroke of the 2 plungers, and is instead 1/3cc 09-Mar-19 12:15 PM will revierfy and continue experiments in a bit, but yeah, interesting stuff thus far.. sure changes some of my equations if it is the case 09-Mar-19 12:15 PM I should really take the whole thing apart and measure stuffs 09-Mar-19 12:22 PM do it! 09-Mar-19 12:22 PM post photos! 09-Mar-19 12:23 PM no new photos.. just a digital tachometer that I velcrod to the variac 09-Mar-19 12:26 PM (of the dismantling, I meant) 09-Mar-19 12:26 PM oh! 09-Mar-19 12:26 PM yes! 09-Mar-19 12:26 PM XD 09-Mar-19 12:27 PM yeah, well, service ktis arent too easy to get in the states.. so before I do that, I would want one on hand.. many seals in various pumps are one time use 09-Mar-19 12:29 PM Oh 09-Mar-19 02:07 PM literature? that is not the black box you said you would treat it as 09-Mar-19 03:08 PM hah, one ref in an Isuzu spec sheet.. 09-Mar-19 03:08 PM either I have a very OEM variant... or that info was wrong.. but... time to run it at various RPMs and double check! 09-Mar-19 04:59 PM 200rpm increments, next round is 2k.. am seeing ~95% now (over ~100) 09-Mar-19 04:59 PM the decrease started around 1400rpm 09-Mar-19 04:59 PM but hasnt really changed much 09-Mar-19 04:59 PM thus far 09-Mar-19 04:59 PM 1600 rpm was pulling about 1L/min 09-Mar-19 04:59 PM semi interesting to note.. 09-Mar-19 05:11 PM 2k still at ~95%.. time for a break 09-Mar-19 07:51 PM 2200 = 90%, 2400 = 82.5% .. noice 09-Mar-19 07:51 PM exact readings I need 09-Mar-19 08:48 PM super neat, right around there is the max flow.. so any additional speed and nope.. limit is about 1.3L/min 09-Mar-19 08:48 PM 66% VE @ 3k RPM 09-Mar-19 08:48 PM ~2300 rpm is when it starts to do the limit though 09-Mar-19 08:48 PM anywho, super neat 10-Mar-19 01:22 AM and thats the pure limit for the engine, then. (or would that overflow the engine with fuel?) 10-Mar-19 01:51 AM Moin! 10-Mar-19 01:54 AM Moin! 10-Mar-19 01:58 AM Bloing! 10-Mar-19 03:02 AM do I dare baking my chamber today? 10-Mar-19 03:02 AM it's raining outside so I can't open the window if it gets to hot in here 10-Mar-19 03:21 AM Why not? 10-Mar-19 03:21 AM and, is it raining that much or is your window badly designed? 10-Mar-19 03:21 AM (in a friendly question tone) 10-Mar-19 03:21 AM (OMFG...I decided to jump into trying to learn STM32 programming...my screams of terror inside could wake up a snorlax) 10-Mar-19 03:22 AM raining heavily 10-Mar-19 03:22 AM + strong winds 10-Mar-19 03:22 AM had my window open , like a 5 cm slit and got drops on my desk, which is ~2m away from the window 10-Mar-19 03:33 AM Hum... 10-Mar-19 03:33 AM bake hot enough to boil any drops? 10-Mar-19 03:33 AM XDDDD 10-Mar-19 03:34 AM I would listen to nixie 10-Mar-19 03:34 AM 10/10 trustful advise 10-Mar-19 03:44 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190310_114409-F4A08.jpg 10-Mar-19 03:44 AM like a christmas tree 10-Mar-19 03:44 AM lets test the smoke detector try 80 °C for a start 10-Mar-19 03:44 AM oof, you can smell the wire wasn't used for a while 10-Mar-19 03:54 AM is it outgassing? 10-Mar-19 03:54 AM XD 10-Mar-19 03:54 AM Very much 10-Mar-19 03:54 AM https://tenor.com/view/lol-dinosaurs-thebaby-hahaha-funny-gif-8843570 10-Mar-19 04:37 AM well, let's go up to 100°C 10-Mar-19 04:37 AM don't want to go any higher because of o-rings 10-Mar-19 04:47 AM Viton can go to 200ºC 10-Mar-19 04:48 AM I don't trust the stuff from ebay china to be actually viton 10-Mar-19 04:50 AM Good point. 10-Mar-19 04:50 AM I baked my oven o-rings up to 200ºC or whereabouts and they did seem unaffected (as material goes, not talking about outgassing) 10-Mar-19 04:50 AM how is it reacting, in any case? 10-Mar-19 04:50 AM will you get even lower pressure? 10-Mar-19 04:52 AM while heating the pressure is rising, once the temp has stabilized it's dropping again 10-Mar-19 04:52 AM I have now reached 100°C, pressure is 7.5e-4, which seems a bit too high... 10-Mar-19 04:52 AM started at e-6 10-Mar-19 04:52 AM quick leakcheck didn't show up anything 10-Mar-19 04:52 AM guess my chamber / o-rings just had lots of water 10-Mar-19 04:58 AM now we wait for the pressure to go down again 10-Mar-19 05:27 AM oof, it's still rising... 10-Mar-19 05:58 AM went down to 80°C, something in there dosen't like the higher temps 10-Mar-19 05:58 AM might have been the epoxy, totally forgot about that 10-Mar-19 06:03 AM I can hear you screaming for an RGA 10-Mar-19 06:04 AM I can hear you bringing me one 10-Mar-19 06:04 AM good thing is: I can play around with that chamber as much as I want, since I've got a new one coming 10-Mar-19 06:04 AM builds a nose-to-KF adapter 10-Mar-19 06:04 AM but not that the new one has unknown problems 10-Mar-19 06:07 AM do you think it does? 10-Mar-19 06:08 AM not really, otherwise there would also be a backup, right 10-Mar-19 06:08 AM but yeah, maybe you'd need to repolish the ISO-K flange 10-Mar-19 06:09 AM right, that chamber's got iso, DN100 by any chance? 10-Mar-19 06:10 AM looked more like DN160 10-Mar-19 06:10 AM damn it 10-Mar-19 06:10 AM or was it CF? damn 10-Mar-19 06:10 AM I don't know, you have the chamber 10-Mar-19 06:51 AM well, I fcked something up 10-Mar-19 06:51 AM can't get my chamber below e-3 now xD 10-Mar-19 06:51 AM that's somewhat... ironic 10-Mar-19 07:05 AM HA 10-Mar-19 07:05 AM haha 10-Mar-19 07:05 AM hahahahaha 10-Mar-19 07:05 AM the viewport leaked, I guess the expansion rates were too different 10-Mar-19 07:05 AM tightened the screws and boom! 10-Mar-19 07:05 AM 1.6e-7 10-Mar-19 01:49 PM ?memberinfo 10-Mar-19 01:49 PM ?serverinfo 10-Mar-19 01:50 PM humans 99 10-Mar-19 01:50 PM bots 2 10-Mar-19 01:50 PM the uprising has begun 10-Mar-19 01:50 PM They are coming for use 10-Mar-19 01:51 PM "region us-east" (just the server) 10-Mar-19 01:51 PM Yeah 10-Mar-19 01:51 PM I had it as west coast but moved it to east to try and get better performance for our friends across the Atlantic 10-Mar-19 01:52 PM thanks! 10-Mar-19 01:52 PM honestly, just move it to germany, highest user density here 10-Mar-19 01:52 PM Nah 10-Mar-19 01:52 PM but lowest internet. 10-Mar-19 01:52 PM It's still my server... 10-Mar-19 01:52 PM you could move to germany, too 10-Mar-19 01:52 PM GIGA speed, up to 400 mbit! 10-Mar-19 01:53 PM I like my surplus... 10-Mar-19 01:54 PM https://giphy.com/gifs/reaction-MMosGw0xKIZji 10-Mar-19 05:22 PM Joined the server. 11-Mar-19 01:00 AM Morning! \o/ 11-Mar-19 01:07 AM Moin! 11-Mar-19 02:17 AM Moin! 11-Mar-19 02:24 AM moin 11-Mar-19 03:02 AM can anyone here tell me why the hell it is snowing out there? 11-Mar-19 03:03 AM burn the snow away 11-Mar-19 03:03 AM pls 11-Mar-19 03:04 AM I'm not hans 11-Mar-19 03:11 AM go and get hans! 11-Mar-19 03:11 AM he's invited, but his train won't arrive due to 3+ mm of snow on the rails 11-Mar-19 03:14 AM thats heavy... 11-Mar-19 03:15 AM heavy snow? 11-Mar-19 03:15 AM uhh I want it to be snowing D2O 11-Mar-19 03:25 AM Just imagine all the stuff hobbyists could do 11-Mar-19 03:30 AM LMAO 11-Mar-19 12:25 PM Got a email from a head hunter about a cleanroom nanofabrication job at... Facebook. What strange times we live in... 11-Mar-19 12:39 PM weird.. 11-Mar-19 12:40 PM OOOOHH 11-Mar-19 12:40 PM a job! 11-Mar-19 12:40 PM XD 11-Mar-19 12:40 PM I haven't had any replies from any of the three scientific glassblowers I contacted. I found the fourth (the one in my area I tried for the other three to refer me to him) and wrote him too. 11-Mar-19 12:40 PM And then they wonder why that art is dying (in spain)...yeah, right. 11-Mar-19 12:50 PM Facebook probably needs techs to build their tracking chips they implant in people to datamine all the things :P 11-Mar-19 12:53 PM XD 11-Mar-19 08:11 PM Joined the server. 11-Mar-19 08:46 PM Joined the server. 12-Mar-19 12:41 AM cleanroom used for safe space 12-Mar-19 02:29 AM moin! 12-Mar-19 03:00 AM Coin! 12-Mar-19 01:56 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190312_215603-CC455.jpg 12-Mar-19 01:56 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190312_215526-22E1B.jpg 12-Mar-19 01:56 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190312_215506-FF129.jpg 12-Mar-19 01:56 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190312_215554-57A56.jpg 12-Mar-19 01:56 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190312_215539-2B3DE.jpg 12-Mar-19 01:56 PM anything you recognize @AdamMcCombs ? 12-Mar-19 01:56 PM the "Microscope interlock" got me thinking 12-Mar-19 02:42 PM 15% off ebay today, up to $100 off, likely US only 12-Mar-19 03:09 PM Ohhhhh, lovely valve! 13-Mar-19 01:39 AM yeah 13-Mar-19 08:18 AM @GigaSquirrel oh yeah that's half of an Oxford load lock assembly 13-Mar-19 08:18 AM May have been attached to a cryo sem system at one point. 13-Mar-19 08:19 AM uhh, sweet 13-Mar-19 08:22 AM Here is a later version of that system 13-Mar-19 08:22 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Gatan_Alto-C19EF.png 13-Mar-19 08:29 AM wait, is that an optical microscope combined with an sem? 13-Mar-19 08:31 AM Yeah 13-Mar-19 08:31 AM It just to look at the sample why you freeze fracture it 13-Mar-19 08:54 AM maybe we'll find the rest of it next saturday 13-Mar-19 08:55 AM I would definitely be interested in it... 13-Mar-19 08:55 AM @Koelzer can help us search 13-Mar-19 08:55 AM in the valve or the rest? 13-Mar-19 08:55 AM The rest 13-Mar-19 08:55 AM ah, ok 13-Mar-19 08:55 AM could have guessed that :D 13-Mar-19 08:55 AM we'll see what we can find ;) 13-Mar-19 09:39 AM @AdamMcCombs do you want the valve, too? i don't think i have a need for it... 13-Mar-19 10:35 AM mounted to the scope, i would take it 13-Mar-19 04:14 PM ...hey I know I haven't posted here in a while but like 13-Mar-19 04:14 PM Dude 13-Mar-19 04:14 PM http://www.3ders.org/articles/20190313-bu-researchers-3d-print-acoustic-metamaterial-that-cancels-sound-without-blocking-airflow.html 13-Mar-19 04:14 PM Acoustic metamaterials 13-Mar-19 04:14 PM So freaking cool 13-Mar-19 04:14 PM Wanna see if i can make one that gets some level of similar behavior using my bad SLA printer 13-Mar-19 04:19 PM oohh neat 13-Mar-19 04:19 PM Also doesn't matter how often or not you post here :P 13-Mar-19 04:19 PM Some of us have periods of extreme productivity and periods of extreme lazyness, and during those times we will be more or less active, its pretty normal. 13-Mar-19 04:19 PM Also some of us have hobbies other than high vacuum :P 13-Mar-19 04:54 PM I wonder how and if that works 14-Mar-19 12:14 AM @sync the 3d printed open-air attenuator? 14-Mar-19 12:14 AM It works using metamaterialistic properties 14-Mar-19 12:14 AM A metamaterial is a weird thing. Basically, the idea is that take a material that does exist in the real world, and you make it do something that should theoretically not be possible in classical physics, in a sense 14-Mar-19 12:14 AM The basic idea is that you use small building blocks of matter with specific predicable properties in terms of how they do things like reflect/redirect energy 14-Mar-19 12:14 AM Then you arrange those blocks in an array of some kind, and the result is that you can do things like create a negative index of reflection 14-Mar-19 12:14 AM I.e. you can make something reflect straight back on itself with inverted phase, for instance 14-Mar-19 12:14 AM So you can set up really weird resonances and things that can be used for things like, among other uses I've seen listed, completely passive radiative signal columnation 14-Mar-19 12:14 AM Usually tho metamaterials are exclusively an RF field of research, this is the first time I've ever seen someone make an acoustic metamaterial. 14-Mar-19 12:14 AM What they're doing is basically reflecting instances of the sound wave being transmitted inwards into that big hole in the middle 14-Mar-19 12:14 AM So, you gave the main sound wave, and then you have the incident reflected inverted sound wave interacting with it, creating a much lower magnitude sound wave 14-Mar-19 12:14 AM You can think of it as being the endpoint of a large resonant chamber, I guess. It's complicated, basically, but imo it's brilliant 14-Mar-19 12:14 AM It's the same concept as active noise cancelling basically -- transmit the inverse to create a space of 0 pressure differential -- but it's done purely using passive components 14-Mar-19 12:14 AM Pretty smart tbh 14-Mar-19 01:31 AM Super interesting! 14-Mar-19 01:31 AM Reminds me of the hallbach arrays, (as in that a specific arrangement can produce weird results. 14-Mar-19 01:32 AM you're not talking about that free energy motor bullsh1t, are you? 14-Mar-19 01:32 AM Now I need for that kind of material to also be a good shock absorber, and make that into a motorbike helmet lining. 14-Mar-19 01:33 AM oh and good morning 14-Mar-19 01:33 AM looks at @GigaSquirrel Really? by now, you dare to think I would do that? (moves blanket over his offgrid magnetic generator powering the whole house) 14-Mar-19 01:33 AM 14-Mar-19 01:33 AM Morning! 14-Mar-19 01:33 AM No, just talking about the hallbach arrays of magnets to increase magnetic force on one side of them. 14-Mar-19 01:33 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/halbachvsalt-61B7A.png 14-Mar-19 01:33 AM (that's much simpler than what hedgeberg posted, sure!) 14-Mar-19 01:35 AM (It's not a contest ) 14-Mar-19 01:36 AM (I mean't as that I understand the metamaterial is MUCH more complex than a magnet array) 14-Mar-19 01:47 AM Correction, if that works as it says, that could be inserted inside the helmet ear spaces. 14-Mar-19 03:52 AM hmmmmm... so could you also invert the function of that audio-metamaterial to generate much louder noise without additional input? 14-Mar-19 03:52 AM moin btw 14-Mar-19 04:40 AM Facebook Nanofabrication? That sounds evil 14-Mar-19 04:43 AM @Pan Da that would require inputting energy (afaik), what you described could be a horn to impedance match(?) the loudspeaker or sound generator to the surrounding air. (speculative exercise) However, let's say the structure amplifies sound. It is going to rob energy from some waves and put them into other waves, so it's not going to work for normal audio, it might clip it to an extent to enhance some frequencies. and for a "single" frequency audio, it might get louder, but it will change something in it, maybe make the wave top sharper (going from a sine to a spiked shape) Reminds me of this: https://en.wikipedia.org/wiki/Rogue_wave 14-Mar-19 04:50 AM The other day we had a discussion about why pulse fusors aren’t a thing... personally I think the answer is health physics. I want my neutrons at a constant rate so I know what is safe. A pulse means it’s too easy to dose yourself and not know until it’s done. 14-Mar-19 04:55 AM @a_quiet_scientist simple solution to that. Set up the system with proper safety and you should be fine. Most research and industrial systems out there are pulsed. It's just a matter of taking the time to set everything up safely. So don't stand next to it when it's running, proper shielding, remote setup and diagnostics, etc. The system I'm working on now is a pulsed system and is significantly more dangerous than a fusor, it's just a matter of engineering the system well with a proper setup. A lot of people just try to rush to make neutrons with a fusor. 14-Mar-19 04:55 AM @Nixie @GigaSquirrel hallbach arrays are pretty cool, I've looked at implementation of them before for accelerators fir things like permanent magnet based optics 14-Mar-19 06:21 AM Random cleanroom photo. Sometimes I miss blue light 14-Mar-19 06:21 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-A4DB4.jpg 14-Mar-19 06:24 AM Oooooohhhh 14-Mar-19 08:43 AM yeah, I hated working in the litho rooms 14-Mar-19 08:43 AM smells like photoresist? 14-Mar-19 08:43 AM after you got out everything looked real strange 14-Mar-19 08:43 AM yeah, like with las0r goggles 14-Mar-19 08:43 AM the floor is now photoresist 14-Mar-19 08:43 AM @a_quiet_scientist is that at your university? 14-Mar-19 01:50 PM god how could you ever not like the orange rooms 14-Mar-19 01:50 PM I get migraines, and the orange rooms are so soothing for them 14-Mar-19 01:50 PM Takes the photosensitivity issue right out 14-Mar-19 06:04 PM Joined the server. 15-Mar-19 12:24 AM Does anyone know of something like an adhesive polymer sheet that would evaporate nicely under a 2.5W blue laser without producing too many fumes? 15-Mar-19 12:43 AM I found one once, let me look it up for you. 15-Mar-19 12:43 AM https://ikonicsimaging.com/lasertape.html 15-Mar-19 12:43 AM BUT, I don't know if that works with 2.5W 15-Mar-19 01:06 AM It looks like it should work. Worst case I tighten the beam to max, max power, and go slow. 15-Mar-19 01:06 AM I'd also do a painted solution fwiw @Nixie 15-Mar-19 01:06 AM I'm looking for something etch resistant 15-Mar-19 01:27 AM I think tht one is, but not totally sure. 15-Mar-19 01:36 AM I've lasered traditional double-sided sticky tape (scotch tape type stuff) before with good effect... not sure what fumes were generated as they were exhausted out the window immediately 15-Mar-19 01:36 AM https://www.youtube.com/watch?v=igqv5dtiv6g 15-Mar-19 01:39 AM I tried lasering kapton, and the film does fine, but it left the adhesive in place, and for very fine detail scrubbing would remove the tape anyways. 15-Mar-19 01:39 AM I guess in the case I posted, we cut the tape layer first, then applied it to the substrate later 15-Mar-19 03:00 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1726-DDAEA.jpg 15-Mar-19 03:00 PM Mmm cutsie turbo. Bearings seem decent too! 15-Mar-19 04:26 PM You know... This is odd. So the Turbo-V70 has a few different frequency ratings between different ones I see online... 15-Mar-19 04:26 PM The specs in the docs say 1250Hz, which times 60 is the operational speed of 75,000 RPM 15-Mar-19 04:26 PM But like mine says 1176Hz, I've seen one on ePay at 1166Hz... 15-Mar-19 04:26 PM I am wondering if when they re-certify them they test them to a certain speed for stability and if say balance has gone off slightly, instead of re-balancing they just rate it at a lower frequency and thus a lower speed, like mine will only run at 70,560 RPM at 1176 Hz 15-Mar-19 04:26 PM Dunno if anyone knows why the frequency/speed would be different against the exact same model turbo even though the technical documentation doesn't say that should be a thing. 15-Mar-19 11:46 PM ok 16-Mar-19 02:14 AM moin! 16-Mar-19 03:41 AM Coin! 16-Mar-19 10:50 AM Joined the server. 16-Mar-19 02:14 PM I need to do a little coding for the suction valve experiments.. not too much as I've done similar stuff before and still have the code on hand, but still.. and will likely take a bit of incremental runs before I get to the actual range.. maybe an hour or so of runs before I get into the range I need to be in 16-Mar-19 02:14 PM I had data from running it with high pressure before and the current needed was entirely different than the valve sitting on my desk.. but this will be no high pressure but atleast flow going through 16-Mar-19 02:14 PM about 23 decimal dfferences (maybe incr by 2 or more to catch up) from what was on my desk vs what worked on the bench 16-Mar-19 02:14 PM anywho, some planned flow experiements.. basically the other half of the equation 16-Mar-19 02:14 PM the only thing missing after this will be the temperature relationaship 16-Mar-19 02:14 PM and then of course making the PID for regulating the pressure 17-Mar-19 01:51 AM It’s a collaborative sort of lab that several universities share 17-Mar-19 01:51 AM Maybe they de-tune the resonant frequency of the turbopump slightly to make it Stuxnet resistant 17-Mar-19 01:51 AM I’m thinking of making a fusor HV feedthrough myself. 2.75 CF blank flange and an alumina tube 5mmODx3mmID 17-Mar-19 01:51 AM Maybe torrseal on the inside and jb weld on the outside because jb is stronger but I don’t know if it’s good for vacuum 17-Mar-19 01:51 AM And a bit of M3 allthread down the middle and a little more torrseal 17-Mar-19 01:51 AM For like 30kV use 17-Mar-19 01:51 AM Sound sensible? Or poor? 17-Mar-19 03:58 AM OHHHHHH 17-Mar-19 03:58 AM @Conmega what size is it? 17-Mar-19 03:58 AM AH! ISO63 17-Mar-19 03:58 AM prepares gear to steal it from him 17-Mar-19 03:58 AM I shall find one similar in the future for the dodecagonal vacuum chamber. 17-Mar-19 08:01 AM @a_quiet_scientist the way I will approach high voltage feedthroughs, mainly for my small chamber for beam stuff will be using compression fittings to alumina tube and the conductor. Cost a bit more, but has a lot of flexibility for quick changes, and garaunteed to rated vacuum of the seal 17-Mar-19 08:09 AM So for a 2.75" conflat chamber to 1"od alumina tube to 1/2" conductor for example, I would go: 2.75" conflat chamber --> 2.75" conflat to 1" compression --> 1" alumina tube --> 1" compression to kf --> kf to 1/2" compression --> 1/2" conductor (solid) 17-Mar-19 08:09 AM For like 30kv use though, your idea should work perfectly fine (depending on ultimate vacuum you want.) The way I will do it is mainly for flexibility and quick changes, going to much higher pulsed voltages. 17-Mar-19 02:55 PM That ISO63 turbo is beautiful, I want one 17-Mar-19 03:05 PM @a_quiet_scientist keep an eye on ePay for Varian Turbo V70 17-Mar-19 03:05 PM They come up a LOT I think they were super common 17-Mar-19 09:05 PM ?serverinfo 17-Mar-19 11:38 PM Huh? 17-Mar-19 11:38 PM Also, morning! \o/ 18-Mar-19 12:21 AM moin 18-Mar-19 02:08 AM “You affirm this product exported from the United States will not be used for nuclear technology” Hmmm. I think technically I just lied. A tiny bit 18-Mar-19 02:16 AM @Conmega I’m a little wary of ePay turbos - too many things in them that might be broken 18-Mar-19 02:19 AM Yeah, but where else to get them? ^^U 18-Mar-19 02:19 AM (at a reasonable price for hobbyists, I mean) 18-Mar-19 02:25 AM Moin! 18-Mar-19 02:42 AM Yeah true 18-Mar-19 09:39 AM Joined the server. 18-Mar-19 12:43 PM Welcome! 18-Mar-19 12:46 PM 110kv oil tank for a TEM filament power supply. 18-Mar-19 12:46 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190315_120604-BDAB9.jpg 18-Mar-19 12:49 PM #show-and-tell maybe? 18-Mar-19 12:50 PM I'm working on bring up on it so it may very well turn into a discussion... 18-Mar-19 01:01 PM Just take a swig and see if you can identify the vintage 18-Mar-19 01:15 PM Ah, proceed, then. 18-Mar-19 01:15 PM XDD 18-Mar-19 03:28 PM I hope I don't have to go into my HV tank... 18-Mar-19 10:57 PM Mmm polychlorinated biphenyl 19-Mar-19 01:58 AM it doesnt look that old, so I think they didn't use that 19-Mar-19 07:19 AM Joined the server. 19-Mar-19 07:30 AM Hello, I'm looking to buy a used UHV vacuum chamber for a 10 to 20 cm3 volume for an personnel experiment with ions and laser beams (a lot view-port are needed:more than 4 viewport). Mechanical requirements should be a Vaccum that looks like, more or less, the one attached. My experiment pressure will be between 10^-9 to 10^-10 torr. So i need to have a Turbo Pump and an Ion pump. I'm a complete newbie to Vaccum stuff Do you know someone in Europe that sell such used setups. ? Thanks . Yann 19-Mar-19 07:30 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/2Q-BE0DD.png 19-Mar-19 07:32 AM Welcome @yann35! Glad you got my message and decided to reach out to this community as well! 19-Mar-19 07:32 AM A chamber like that is definitely going to be a custom part. Appears to be an 8" conflat nipple section maybe 3" long with x8 2.75" conflat adapters. 19-Mar-19 07:41 AM welcome! 19-Mar-19 07:41 AM where in europe? 19-Mar-19 07:41 AM germany by any chance? 19-Mar-19 07:42 AM I'm located in France but I would be able to buy such system anywhere from europe I think 19-Mar-19 07:43 AM ah, ok 19-Mar-19 07:43 AM well, I might get a chance to get my hands on some systems like that in the coming month(s) 19-Mar-19 07:43 AM so, if you're willing to wait we might get a chance 19-Mar-19 07:45 AM Ok thanks. Don't hesitate to contact me on this channel when you will have found such systems (or a system near to this configuration for the vacuum chamber) 19-Mar-19 07:46 AM Will do 19-Mar-19 07:46 AM are you looking for a complete system or just the parts and build it yourself? 19-Mar-19 07:51 AM Both option could be studied 19-Mar-19 09:37 AM Out of curiosity, do you have more photos of the chamber you showed? 19-Mar-19 09:54 AM But be aware! Nixie will copy the design and rebuild it at home with his skills 19-Mar-19 10:21 AM probably 19-Mar-19 12:47 PM Thinking about the chamber, 10/20cm3 is not THAT big. 19-Mar-19 12:47 PM could be milled from a single piece of metal without much effort. 19-Mar-19 12:47 PM the only drawback is the CF seats for those extreme low pressures. And also, if they are going to be lasers shined through, window axial perpendicularity must be extremely good. 19-Mar-19 01:50 PM Hi I would like to introduce myself. I am Johannes and is from a hackerspace, Omega Verksted(https://omegav.no/), in Norway. We have been geting into high vacuum work recently. We have gotten quite a bit of high vacuum equipment. Among them a varian vacuum coating setup and a Hitachi TM-1000 table top sem. Unfortunatly we are missing the software for the microscope. Hitachi recently got back to us with a qoute for the software 2000 euro. I am just wondering if this manufactures normaly charges this much for such software. Keep in mind that the microscope is probobly 15 years old. Alternatly might someone in this group have acces to this software? 19-Mar-19 01:51 PM @AdamMcCombs is our SEM guy, if he dosen't know a source there is none 19-Mar-19 01:53 PM Ok. I have been in breef contact with him over twitter a while ago. 19-Mar-19 01:53 PM Here is some pictures of our coting setup: https://confluence.omegav.no/display/OV/Varian+3119+Vaccuum+Chamber 19-Mar-19 01:53 PM We have not gotten it wroking yet. It has been in storage for the past 20 years. 19-Mar-19 01:53 PM It is capable of both Electron beam deposition and evaporation deposision. The electron beam powersupply is 10kV, 1A. 19-Mar-19 02:07 PM I take the photo on Internet 19-Mar-19 02:28 PM @johannesw that page... the descriptions... i like you guys. :-D 19-Mar-19 02:28 PM and the machine is beautiful. wow. 19-Mar-19 04:02 PM Thanks. We are located at a universety so we are able to get some stuff that is getting thrown out. 19-Mar-19 04:02 PM ah, that's always nice. 19-Mar-19 04:49 PM Beautiful AND huge. XD 19-Mar-19 04:49 PM Also, welcome! 19-Mar-19 05:16 PM that's what she said. 19-Mar-19 06:57 PM We had to get a bit creative to save on space. 19-Mar-19 06:57 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20190320_025653-31727.jpg 19-Mar-19 07:03 PM The Pfeiffer Vacuum Technology Book is largely just a catalog selling their stuff you’ll never be able to afford - but there are some really good parts in the theory parts. Like a really good explanation of the stability equations for a quadrupole mass filter and how they translate to RF/DC drive voltages 19-Mar-19 07:03 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-E7B4F.jpg 19-Mar-19 07:03 PM Wow. That’s my kind of hackerspace 19-Mar-19 09:32 PM So I found this little shop of jewellery making supplies 19-Mar-19 09:32 PM Ti wire, SS wire, Ag, Cu, brass in all diameters, mesh, foil, exotic solders and fluxes, etchants, little metal spheres - all sorts of wonderful great stuff! 19-Mar-19 10:40 PM @johannesw Check your Twitter dm. 19-Mar-19 10:55 PM What’s the best way to protect vacuum parts disassembled in atmosphere? Foil or plastic caps? 19-Mar-19 10:56 PM Varies a lot 19-Mar-19 10:56 PM What vacuum, what plastic, and what oil is used when making the foil 19-Mar-19 11:43 PM That lab needs a sign that goes somewat like this: "Short people should bring their own ladders" (I'm on the near-to-ground height spectrum, so I'm entittled to make short people jokes, unlike @Pan Da ) 19-Mar-19 11:43 PM Also, Morning! \o/ 20-Mar-19 01:19 AM moin 20-Mar-19 01:19 AM @Nixie is it difficult to make glas chambers? 20-Mar-19 01:19 AM @Nixie in principle it should be possible to build a machine that makes them 1k per minute style ... like jars for marmelade, right? 20-Mar-19 01:19 AM (could u design such a machine in fusion pls (jk)) 20-Mar-19 02:02 AM IDK really. 10^-6, not UHV, ordinary plastic caps sold with CF components to protect the flange. I know you can get fancy UHV science foil but let’s just say it’s consumer Al foil. 20-Mar-19 02:17 AM science foiiiil 20-Mar-19 02:28 AM Moin! 20-Mar-19 02:54 AM @N00N It is not (in part) because it's difficult, but that glassworking requires tools you don't easily find, to some extent. Especially if you want to work with borosilicate OR fused silica. 20-Mar-19 02:54 AM I mean, even in spain I can buy secondhand metal lathes, for example, but a glass lathe would be nowhere to be found. 20-Mar-19 02:54 AM For a more industrialised production, yes, a machine could churn glass chambers like bottles (not at 1K per minute, though) With the proper two sided mold, and internal blowing, a shape not that dissimilar to the one posted by yann35, could be made. 20-Mar-19 02:54 AM It would still require glass machining to ensure flatness (but that can be done). Metal machining would be much easier, in any case. 20-Mar-19 03:09 AM Hm... @yann35 are you sure your volume calculation is correct? 20cm3 is just a cylinder with 3cm in diameter and 3cm height. (21.2cm3) I am not even sure there are CF ports small enough. XD (unless the openings for the viewports are much bigger than the chamber. 20-Mar-19 03:11 AM @Nixie yeah, molding would be perfect, so that the tools could simply made of steel with water cooling, right? 20-Mar-19 03:11 AM "simply" 20-Mar-19 03:11 AM and btw couldnt u use a normal lathe for glas stuff? attach a few burners and voila? 20-Mar-19 03:14 AM Hum ...; @Nixie you'r right. The devices i need to put in the UVH Chamber is 10cm10cm10cm (around)... So the useful volume I gave is not correct... ;-p 20-Mar-19 03:15 AM Thats my vacuum chamber volume XD 20-Mar-19 03:15 AM Altough it's shaped the other way around Metal on the edges, and a circular glass envelope. 20-Mar-19 03:16 AM glass tissue over metal endoskeleton 20-Mar-19 03:20 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/9697161532518782623-991F1.png 20-Mar-19 03:21 AM looks like a blender 20-Mar-19 03:21 AM :3 20-Mar-19 03:23 AM @N00N the issue with using a normal lathe for glass, is that you could damage the ways with the heat (accidentally de-hardening parts of them (spots, more probably) 20-Mar-19 03:23 AM ah ok 20-Mar-19 03:25 AM Also, you would not blow everything from a single piece, but more probably attach the viewports to a big glass boule, using sinchronized heads, wich a normal lathe doesn't have. 20-Mar-19 03:27 AM ok ok 20-Mar-19 03:37 AM and at the new 101010cm that glass would have to be immensely thick. better to stick with metal. 20-Mar-19 04:28 AM New baby 2.75 chamber 20-Mar-19 04:28 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-277DC.jpg 20-Mar-19 04:37 AM Lovely! 20-Mar-19 04:38 AM so cute ❤ 20-Mar-19 06:34 AM Fusor forums reminds me a lot of amateur radio... completely dominated by grumpy old men 20-Mar-19 06:40 AM ehehe yeah 20-Mar-19 06:41 AM This is why I like making friends with the prof and getting in his favour 20-Mar-19 06:41 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-7B78C.jpg 20-Mar-19 06:43 AM I hate rotatable CF especially when the flange bit gets jammed at an angle and you can’t tap it back down 20-Mar-19 07:00 AM totally agree on the fusor forum 20-Mar-19 07:00 AM and damn, that's the good stuff 20-Mar-19 07:02 AM gawd... 20-Mar-19 07:02 AM ohh yes 20-Mar-19 07:03 AM it can't be like that in the forums, there's young people in there: 20-Mar-19 07:03 AM https://www.popsci.com/science/article/2012-02/boy-who-played-fusion#page-3 20-Mar-19 07:05 AM There are two major groups now in the forums. The really old guys who have been there forever, and a large influx of super young kids 20-Mar-19 07:06 AM @Nixie he hasn't postet there for years 20-Mar-19 07:06 AM confusion 20-Mar-19 07:06 AM And there are some big issues with the whole Taylor Wilson thing that I think fuels a lot of the wrong motivation for pursuing this stuff 20-Mar-19 07:07 AM what was the motivation? 20-Mar-19 07:07 AM building a doomsday device? 20-Mar-19 07:07 AM Not was, but what it has evolved into, particularly with the most recent admittee to the neutron club 20-Mar-19 07:07 AM (I just looked for the article to mess up with giga, didn't know much about the person) 20-Mar-19 07:07 AM "evolved into"? 20-Mar-19 07:08 AM or is every other motivation wrong? 20-Mar-19 07:08 AM I don't really follow the neutron club, could you elaborate? 20-Mar-19 07:09 AM yes please. 20-Mar-19 07:12 AM I’m sure if Richard Hull was watching me wrap a length of 0.9mm Ti wire around a sharpie right now he would have something to moan and complain about 20-Mar-19 07:12 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-4EE60.jpg 20-Mar-19 07:12 AM chainmail! 20-Mar-19 07:13 AM Nuclear chainmail! 20-Mar-19 07:13 AM out of couriosity, why Ti? 20-Mar-19 07:13 AM Is the "most recent admitee" , Jackson Oswalt? 20-Mar-19 07:14 AM I could get it and it was cheap and it’s like #3 on Hull’s sacred FAQ list of materials you should use, and I couldn’t get W or Ta cheap and quickly 20-Mar-19 07:14 AM Oh, ok 20-Mar-19 07:14 AM you're not in europe, right? 20-Mar-19 07:15 AM Australia 20-Mar-19 07:15 AM if you are I could mail you some .5mm W wire 20-Mar-19 07:15 AM whoops 20-Mar-19 07:16 AM (deleted the gif because the reference is super flimsy) 20-Mar-19 07:20 AM Regardless of what metal it is, NFI how I’m going to weld it 20-Mar-19 07:20 AM The Sharpie mandrel is giving me ~ 15mm which seems reasonable for the 2.75” chamber 20-Mar-19 07:20 AM I put the Cu conflat gaskets in, 3 bolts in and just barely tightened finger tight - I’m hoping this means the gaskets are not committed and are reusable 20-Mar-19 07:20 AM (Got 10 anyway of course) 20-Mar-19 07:20 AM We should replace dead gauge society with dead gadfly society 20-Mar-19 07:20 AM *gasket 20-Mar-19 07:26 AM gadfly? 20-Mar-19 07:26 AM just googled it, didn't know that word 20-Mar-19 07:26 AM those weird kids with their weird yellow gauges and weird russian detectors! 20-Mar-19 07:28 AM The fusor has kind of evolved into a device for quick and easy fame, rather than scientific pursuit. There is massive hype around fusion in general due to the lack of public knowledge and basics about the science. Recently there has been a huge rush by younger and younger people to get into the neutron club, competing for youngest just for the sake of the title. Once it eeks out detectable neutrons, the projects often stop, no further work or optimization. I have been watching the forums for a while now, and over time, particularly in the past year, things have kind of stagnated. No push to innovate or drive the science further, explore new territory. All the same simple stuff, but very little motivation or advance to drive into new areas not explored with the fusor before. Many put the fusor community on a very high pedastal, when in reality the fusor is one of the most easy and simple plasma and neutron devices to build - vacuum requirements are pretty loose, power is low, and really minimal engineering effort is needed. This stagnation is on part of the community as a whole - the older guys not wanting to push new territory, the younger guys having no experience or background at all to push beyond the basics. 20-Mar-19 07:28 AM In terms of Taylor wilson, he was touted as a genius and became famous for his fusor. However, he did not build it purely on his own - he had the backing of a very well equipped university lab and significant professional mentoring, along with most of the tools and parts available at the lab. What he accomplished and became famous for was something that many others had done before him and with completely scavenging from nothing on their own over years of patient and great effort. As of recent, it appears the rules have changed a bit to enforce better documentation of the process, as well as eliminating the title of youngest fusioneer due to concerns of transparency and issues with potentially parents taking advantage of the title for the wrong reasons. Sorry if I have offended any fusor enthusiasts here, just my observations on the subject having been involved with and watching the community for a while now. 20-Mar-19 07:34 AM I agree but I’m still building it 20-Mar-19 07:35 AM I still think the fusor forums provide a great resource for people pursuing the topic, and have contributed a huge amount to the amateur physics community, and inspired a lot of people to pursue this field. 20-Mar-19 07:36 AM I don't think anything you said could be marked as offensive. 20-Mar-19 07:38 AM That being said, I still think that people who pursue the fusor now should try to advance it more than just doing what has already been done. Still so much to explore! So for those of you out there are working on the fusor, I personally challenge you to try what the community hasn't already yet. Lead new developments, push the boundaries further. 20-Mar-19 07:54 AM Good night all 20-Mar-19 08:07 AM good afternoon to you, too! 20-Mar-19 08:36 AM I thing the fusor forum needs something like ">e6 n/s club", "Activation club" etc 20-Mar-19 08:36 AM if people want bragging goals let them work for it 20-Mar-19 08:40 AM I agree, a fusor is one of the most simple things you can build 20-Mar-19 08:48 AM simple to build and yet there are many Things one can do with it 20-Mar-19 08:52 AM Bahahaah 20-Mar-19 09:01 AM Eh, you can do some stuff with fusors, but they are still overall pretty limited. Intense beams are significantly more versatile, but I'm sure you all are sick of me repeating that point lol. 20-Mar-19 09:22 AM but intense beams are way harder to achieve if you're only looking for a neutron source 20-Mar-19 09:26 AM Oh yeah lol, if you only want a neutron source then fusors are the way to go 20-Mar-19 09:26 AM Until you want to start breaking the 10^8 per shot range, or even neutrons without deuterium... 20-Mar-19 09:45 AM no Deuterium, but... uranium? :D 20-Mar-19 09:50 AM Lol no uranium, not getting that nuclear! 20-Mar-19 09:50 AM naw 20-Mar-19 09:50 AM but what are you talking about? 20-Mar-19 09:50 AM iirc the cross sections for fusion are tiny for most other nuclides 20-Mar-19 09:50 AM unless you're talking about spallation / fission / fractioning, which should be somewhat doable with most 20-Mar-19 09:52 AM Yeah, not talking fusion anymore 20-Mar-19 09:53 AM 5 MeV He(2+) onto Be target? :D 20-Mar-19 09:55 AM Fusion is easy. Can do it on the table. Spallation, now that takes some planning 20-Mar-19 09:56 AM yep 20-Mar-19 09:56 AM And He is not necessary, H will do the job. Much easier in this configuration anyway 20-Mar-19 10:10 AM p-n thresholds are quite low for several elements - Li, Be, B, C 20-Mar-19 10:11 AM quite low is still MeV range, right? 20-Mar-19 10:12 AM Yeah. Low for big machines, but untouched for makers at home 20-Mar-19 10:14 AM for bigger machines it is actually too easy 20-Mar-19 10:14 AM first time I was in an accelerator I was actually surprised that the neutron dose rate was ~10x as big as the gamma dose rate 20-Mar-19 10:15 AM Yeah, I think big machines often have a min lower energy. Like the electron linac I work at can only go as low as like 20MeV min lol 20-Mar-19 10:17 AM well, the one here is a tandem, powered by a van de graaff generator, afaik it can go down to basically zero 20-Mar-19 10:18 AM Yeah, a lot of RF ones can't do that really 20-Mar-19 10:18 AM Well, technically we can just fire the gun without any RF, but I don't think it would transport well through the whole length 20-Mar-19 10:18 AM Easier when you have a DC system you can smoothly crank up from 0 to max lol 20-Mar-19 10:20 AM from 0 up to wherever it arcs over 20-Mar-19 10:20 AM but I guess a DC accelerator is actually harder to make at home, compared to pulsed power 20-Mar-19 10:20 AM at least if you want to get above let's say 500 keV 20-Mar-19 10:25 AM Much harder. I've looked into the feasibility, not practical at our level. At most I've seem maybe 150kev. The problem is, people often don't take into consideration loading effects on the supply the beam will introduce 20-Mar-19 10:25 AM Cockcroft-walton get tricky and expensive above a couple hundred kv, and van de Graf require a lot of engineering to design a system that can handle any load at all 20-Mar-19 10:25 AM At most you are looking at micro amp currents best case for a home system 20-Mar-19 10:25 AM Not enough, I need kAs lol 20-Mar-19 10:27 AM xD 20-Mar-19 10:27 AM still wondering what you're actually up to 20-Mar-19 10:29 AM I do not believe anyone will guess what type MEVI is. It's far forgotten today, though I did come across maybe 1 paper on it from 2017. Most everything else is decades ago. EXEDA is less unconventional, but still not really explicitly discussed like if you were to take an accelerator class at CERN 20-Mar-19 10:42 AM We are eager to see.. 20-Mar-19 10:42 AM Dang 20-Mar-19 10:42 AM XDDDD 20-Mar-19 10:42 AM Can't we just overload you with coffee so you finish sonner? 20-Mar-19 10:44 AM Lol I'm pushing to finish as fast as I can. It's tough when you are also working full time and are married, can't just spend the whole day on the build (though I very easily could, so much to do still.) 20-Mar-19 10:44 AM Not to mention I still haven't tested anything at all yet lol 20-Mar-19 10:45 AM Take my words only as encouragement and interest over your project, only. 20-Mar-19 10:46 AM I know lol, believe me, I am eager to see if I can make it work too 20-Mar-19 10:46 AM you better do 20-Mar-19 10:47 AM Oh, btw 20-Mar-19 10:47 AM @Applied_Ion that CF100 pipe with an extra cf40 connection, do you need more like that? 20-Mar-19 10:47 AM I've got one which is basically the same, except for two 40 ports instead of one 20-Mar-19 10:47 AM I'll get a new chamber next month, if that part is not needed on it I don't need it 20-Mar-19 10:53 AM That's a 6" conflat right? How long is the pipe? 20-Mar-19 10:53 AM 6"ish 20-Mar-19 10:53 AM maybe 8 20-Mar-19 10:53 AM length that is, cf100 is 6", yes 20-Mar-19 10:53 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181009_122716-A3FB4.jpg 20-Mar-19 10:57 AM Ok cool. I'll definitely consider! Having a beam pipe with extra ports is a huge bonus, since I currently am planning now 10 different beamlines for the system. Cf100 is exactly the size of my system as well. That could definitely come in handy for sure! 20-Mar-19 10:57 AM You don't need something like that yourself? 20-Mar-19 10:59 AM I'm trying to avoid CF atm 20-Mar-19 10:59 AM and I'll get many chances to get my hands on something like that in the future 20-Mar-19 11:02 AM Many chances to get more in the future? Sounds like you found quite a secret stash of parts lol. 20-Mar-19 11:02 AM How come you are avoiding cf at the moment? 20-Mar-19 11:04 AM I don't need low pressures, as my only current vacuum project is a fusor 20-Mar-19 11:04 AM and once you've started with CF it tends to get a bit more expensive 20-Mar-19 11:04 AM Yeah, though on the plus side investing now makes it easier to upgrade later 20-Mar-19 11:05 AM Well, decommissioning and decontamination of a synchrotron can get get you quite some parts 20-Mar-19 11:05 AM Holy **** that's amazing 20-Mar-19 11:05 AM That will set you up for sure! 20-Mar-19 11:07 AM I'll stark working there next week, I'm worried I won't be able to carry everything and fit in the car xD 20-Mar-19 11:08 AM This full time work? 20-Mar-19 11:08 AM Make as many trips as possible lol 20-Mar-19 11:08 AM Bigger car 20-Mar-19 11:08 AM Pay friends lots of pizza to help 20-Mar-19 11:08 AM yep, until the semester starts again 20-Mar-19 11:08 AM Sounds awesome! 20-Mar-19 11:08 AM So, should I expect a synchrotron build in your basement? 20-Mar-19 11:09 AM xD 20-Mar-19 11:09 AM it was made for medical isotope production, so spallation etc should not be a problem 20-Mar-19 11:12 AM Do it 20-Mar-19 11:12 AM Actually, with the caps you currently have, you could build a far more powerful accelerator than I could hope to build now lol 20-Mar-19 11:12 AM Easily GW class beams 20-Mar-19 11:12 AM Or maybe build a pulsed fusor with one of those caps. That would be a truly absurd and awesome fusor build. 20-Mar-19 11:12 AM Certainly untouched territory in the fusor community as well 20-Mar-19 11:15 AM the issue is 20-Mar-19 11:15 AM where 20-Mar-19 11:15 AM Basement 20-Mar-19 11:16 AM in my 1.5x3 meter workshop? 20-Mar-19 11:16 AM Yes. Make long control cables, have everyone clear the house, fire it from outside lol 20-Mar-19 11:16 AM xD 20-Mar-19 11:16 AM I'm in a somewhat densely populated area 20-Mar-19 11:16 AM I'll bet someone will call the cops if I let off 50+ kJ pulses 20-Mar-19 11:16 AM and I can't have that atm, I'm currently in a safety assessment for handling nuclear fuel 20-Mar-19 11:19 AM Yeah, makes it tougher lol 20-Mar-19 11:23 AM "Oh yes I can surely work with this safely" He said while irradiating his neighbours as a hobby 20-Mar-19 11:30 AM Lol 20-Mar-19 12:45 PM Note the "atm" wich doesn't discard the future. 20-Mar-19 03:30 PM People, we have setup a channel for introductions: #introductions_and_directory If you feel inclined to contribute, that can allow people to quickly find common interests, but it's NOT mandatory. Your post can be edited unlimited times, so don't worry about making it perfect at the first try. If you want to add an image, you will have to add text to it (text is editable afterwards) but you can't add an image to the message afterwards. 20-Mar-19 03:31 PM cool! 20-Mar-19 03:31 PM so what about Adam? 20-Mar-19 03:32 PM he still has some homework to do 20-Mar-19 03:51 PM ohhh, ok 20-Mar-19 08:47 PM This NIM power supply plugin has an an interesting provenance. It has seen things. 20-Mar-19 08:47 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-016F5.jpg 21-Mar-19 02:53 AM the bottom symbol looks like a juggling stick figure. 21-Mar-19 06:07 AM What would rough value of a working second hand Pfeiffer hipace 80 be? 21-Mar-19 09:37 AM @cyanoacry what are the benefits you expect from the glass fusor, compared to a metal chamber with a big window? 21-Mar-19 09:37 AM purely presentation 21-Mar-19 09:37 AM Nice! 21-Mar-19 09:37 AM Will watch closely. perches in cyanoacry shoulder and squeaks 21-Mar-19 09:38 AM i also think it'd go a long way as a "hey, amateur science isn't so scary!" coffee table piece 21-Mar-19 09:38 AM in my mind i'd like to run it off of LiPos and make the chamber maybe 4-5" in diameter, with support electronics no bigger than a textbook 21-Mar-19 09:38 AM Just keep in mind plasma heating of the glass, if you go into jet mode that can cause pretty significant local heating. 21-Mar-19 09:38 AM Do you plan to use leaded glass so it doesn't emit much radiation? 21-Mar-19 09:39 AM definitely -- I'm intending on making it a "press and hold for fusion" type of demo 21-Mar-19 09:39 AM that's a secondary concern, I might have to put it in a leaded diorama case 21-Mar-19 09:39 AM but! if your electrons aren't colliding with a metal chamber, maybe there will be less X-ray emission with the glass/e- interaction 21-Mar-19 09:40 AM Glass still produces it's fair share of x rays... 21-Mar-19 09:41 AM ah, i haven't looked at it deeply -- do X-ray tubes use metal targets for efficiency? 21-Mar-19 09:41 AM you still get X-rays from normal bulk stopping, even if it's not glass? (makes sense) 21-Mar-19 09:42 AM Among other things, yes. It's not to say that glass doesn't produce x rays though 21-Mar-19 09:42 AM er, even if it's not metal rather 21-Mar-19 09:44 AM Yeah. Additionally you are also going to get counts on your poiser regardless 21-Mar-19 09:44 AM Other reasons for metal are thermal disapation and the surface won't charge under the beam. 21-Mar-19 09:46 AM that makes sense! the watercooling setups that I've seen for some tubes really wouldn't work without a metal target 21-Mar-19 09:47 AM If you were dealing with charging you would have a really hard time getting the spot size down as well 21-Mar-19 09:57 AM If you are staying below 20kv, xrays wont really penetrate thick glass needed for a glass chamber, though ion heating is still definitely a safety concern. Xray targets generally rely on heavier metals like tungsten or tantalum for high xray conversion efficiency. Voltage determines energy, current determines flux. Though glass will produce some still, but not nearly as efficiently. At your voltages you probably don't have too much to worry about, but start hitting in the many tens of kv to hundreds of kv, that's when to be concerned 21-Mar-19 09:57 AM @ @cyanoacry also awesome to see another EP thruster person here! I don't do it full time like yourself, but still working on it as one of my main projects. 21-Mar-19 10:00 AM i've been following your progress on twitter, really excited to see how your stuff goes! i'm pretty new to the EP field (just started at this company a little over a year ago), it's all pretty neat 21-Mar-19 10:01 AM Great! If you don't mind me asking, what type of thrusters do you work with? 21-Mar-19 10:03 AM ambipolar RF heated thrusters -- we published a pretty comprehensive paper last year: http://www.phasefour.io/wp-content/uploads/2018/07/Siddiqui-and-Cretel-Phase-Four-RFT-updated-performance-measurements-AIAA-2018.pdf 21-Mar-19 10:03 AM it's quite neat, our company is pretty willing to publish results and methodologies as a differentiating business strategy 21-Mar-19 10:05 AM Awesome, I've definitely looked at Phase Four's stuff before! 21-Mar-19 10:05 AM yeah, my day job is to take that half-height RF power rack and... somehow stuff it into the size of a couple of VHS tapes 21-Mar-19 10:05 AM it's quite a challenge 21-Mar-19 10:07 AM Definitely really cool stuff for sure! 21-Mar-19 10:07 AM i think the coolest thing is that we're a lot closer to classical rocket motors than I expected 21-Mar-19 10:07 AM much more "make hot stuff, convert hot into net velocity" vs the "hey we need an electrostatic gradient" that prevails in other designs 21-Mar-19 11:18 AM Yeah, the plasma thrusters are definitely some of the cooler EP, been leaning towards that approach with PPTs since rf is more complicated/expensive to start with lol. Interestingly it appears that PPTs can actually either operate in an ion mode or more like a thermal mode closer to your stuff based on engine configuration. 21-Mar-19 11:19 AM your all way too smart and way too cool 21-Mar-19 11:20 AM yeah 21-Mar-19 03:17 PM says the supercomputer man Is there something akin to bi*chslap but to put an awesome person back in the awesome side? 21-Mar-19 03:17 PM friendslaps @Conmega into space, among the other star kids 21-Mar-19 03:17 PM Don't try to get down into normie (for this group) space, you are too awesome for that. 21-Mar-19 03:49 PM @Conmega I agree with @Nixie lol, I saw the crazy stuff you are working on, don't downplay your stuff. You got some real crazy projects going on yourself I couldn't possibly comprehend doing myself. Not to mention you are actually recognized and known to the outside world beyond a small maker community. 21-Mar-19 05:52 PM Heh, I have a mental image of Hull ranting and raving against glass fusor already 21-Mar-19 05:52 PM Just a miniaturised and cheap fusion-capable power supply would be a great project 21-Mar-19 05:52 PM I like knowing interesting people with fusor knowledge in that sweet spot in between the grumpy old people and the ones who are barely potty trained and building fusors 21-Mar-19 05:52 PM Your propulsion work sounds brilliant! 21-Mar-19 06:07 PM To get fusion, you don't really need that much juice. Detecting it on the other hand becomes much more challenging at the low end. But 20kv at 10mA or more will probably give neutrons, though very low yields that would be a challenge to see. Even beam on target really doesn't require too much. Now you could always get higher numbers on a miniaturized supply "cough" pulsed "cough" 21-Mar-19 06:07 PM Looking at Glassman supplies, which are top of the line standard in terms of hv supplies, a 35kv, 10mA supply is still about as big as a shoebox, it's tough to miniaturize a whole lot more. 21-Mar-19 06:09 PM This advertises 30kV @10mA max https://www.aliexpress.com/item/HIGH-VOLTAGE-SUPPLY-WITH-30KV-OUTPUT/1858563832.html 21-Mar-19 06:09 PM I can't imagine that supply actually working under load though 21-Mar-19 06:10 PM Ya 21-Mar-19 06:10 PM The 40kV and 60kV models also advertise 10mA max 21-Mar-19 06:12 PM Same with all these types of things. Van de graaf, cockcroft walton, flyback. Open voltage is easy, but making it handle full voltage at rated load current under load is tough. Most people that make hv supplies just use them for arcs or charging caps - that stuff is easy. 21-Mar-19 06:13 PM Those chinese units advertize arc detection so I guess not arcs 21-Mar-19 08:18 PM I appreciate the kind words, and sure I am known outside the maker community but also realize I am probably thought about by some like you guys think about the race to the youngest fusor... I basically bought a mainframe and plugged it in and turned it on. Sure I learned how to use it but its like a kid learning to use a computer... Its not a major feat or anything to RTFM and play around with something. I know I'm not dumb but I am severely lacking in the engineering/sciences/maths side of things. I think I can learn and get there but yea some of you have bigger cooler backgrounds than me is all I was saying :P 21-Mar-19 08:18 PM Well... actually thats bad wording... I dunno if anything gets much bigger or cooler than a mainframe ;P 21-Mar-19 11:15 PM for my mini HV supply I was thinking of leveraging steve ward's CCPS design: https://www.stevehv.4hv.org/ccps1.htm 21-Mar-19 11:15 PM if i don't need a whole lot of watts, might be able to fit it inside a VHS tape volume 21-Mar-19 11:15 PM of course that will depend on what the chamber assembly and grids actually look like :) 21-Mar-19 11:28 PM its not kind wording. If something, kind violence. What you say comes with age, but is the drive you have, at the age you had it, that marks you as a star. 21-Mar-19 11:29 PM i've got to agree there -- @Conmega, your background actually reminds me a lot of mine 21-Mar-19 11:29 PM i started out as a random guy who brought home all the computers that my school threw out 21-Mar-19 11:29 PM and then i fell into the right (wrong??) crowd on the internet, and that seemed to play out pretty nicely 21-Mar-19 11:33 PM In any case, we're not saying that to cheer you up. We are just pinpointing reality. You can't escape it. 21-Mar-19 11:39 PM i've got to get my lab setup back in working order -- when i got my first job and real paycheck out of college, i went out and celebrated by buying a scroll pump on ebay 21-Mar-19 11:39 PM that poor pump still hasn't been connected to a chamber... 21-Mar-19 11:48 PM Hmm fusor forums are down. Did they get slashdotted or something? Or hackaday’d or whatever the youth are doing these days 22-Mar-19 12:34 AM That's a nice way to spend a first pay! 22-Mar-19 12:34 AM Aplied Ion closed them up to stirr them a bit. XD (JK!) 22-Mar-19 01:03 AM moin! 22-Mar-19 01:11 AM Gloin! 22-Mar-19 01:40 AM moin 22-Mar-19 05:39 AM Loin! 22-Mar-19 08:24 AM 'morning! 22-Mar-19 08:58 AM YO! 22-Mar-19 08:58 AM I GOT A JOB! 22-Mar-19 08:58 AM Just got a call. 22-Mar-19 08:58 AM Start on Monday 22-Mar-19 08:58 AM good pay, good timetable 22-Mar-19 08:59 AM Congrats, great to hear! 22-Mar-19 08:59 AM What will you be doing? 22-Mar-19 08:59 AM (I know timetable it's not the good word for the job hours and start/end time, but whatever) 22-Mar-19 08:59 AM https://giphy.com/gifs/snl-thumbs-up-awesome-d2Z9QYzA2aidiWn6 22-Mar-19 09:00 AM It's in a truck company, in the R+D area. They do roadworks trucks. 22-Mar-19 09:00 AM Congratulations! 22-Mar-19 09:01 AM I shall learn...how do you name it? those state machines 22-Mar-19 09:01 AM industrial 22-Mar-19 09:01 AM you'll repair the trucks destroyed by adams way to heavy microscopes 22-Mar-19 09:01 AM (they know I don't know them, yet, so it's ok) 22-Mar-19 09:01 AM XDDD 22-Mar-19 09:01 AM I shall see what I fully do on Monday. 22-Mar-19 09:01 AM (thanks to everyone ^^ ) 22-Mar-19 09:05 AM worst thing is 22-Mar-19 09:05 AM you still won't have any money for months since you will now buy all the stuff you've waited for the last few months 22-Mar-19 09:06 AM BAHAHAHA 22-Mar-19 09:06 AM I'm afraid not. 22-Mar-19 09:06 AM I owe 3000€ to a friend (who does not need the money back) 22-Mar-19 09:06 AM So I have to save for returning that too. 22-Mar-19 09:06 AM First, let's hope I fit in there, and I perform as they expect (I was super sincere at the interview, so they already know where my head lies). 22-Mar-19 09:06 AM Then we will find what is what. 22-Mar-19 09:08 AM "I will weld high vacuum chambers to every single truck" 22-Mar-19 09:08 AM They have vacuum chambers, you know, right? 22-Mar-19 09:08 AM Congrats Nixie, now I expect great things because you can afford fancy bits :P 22-Mar-19 09:09 AM (some systems work with vacuum as failsafe, like train brakes) 22-Mar-19 09:09 AM Thanks, let's wait first for things to settle down. (I'm shaking) 22-Mar-19 09:09 AM not vacuum 22-Mar-19 09:09 AM low pressure maybe 22-Mar-19 09:09 AM but not vacuum 22-Mar-19 09:10 AM well larger trucks should have air brakes, the way it works is if you lose air pressure your brakes lock 22-Mar-19 09:10 AM meh, details. 22-Mar-19 09:10 AM they are called vacuum lines, not "low pressure lines". 22-Mar-19 09:10 AM thats a fun concern when moving 34,000lbs of steel at 55mph 22-Mar-19 09:10 AM you don't want to have to spin up your TMP before breaking 22-Mar-19 09:10 AM well most of the air brakes I know don't have "vacuum lines" they just have springs you fight with the 120PSI of air pressure 22-Mar-19 09:10 AM I'm no expert in trucks anyways. don't take my word for that 22-Mar-19 09:10 AM but trains do work with "low meh pressure brakes. 22-Mar-19 09:10 AM AH, no, I didn't mean truck brakes, I meant that somethings in the truck, might work with vacuum, instead of pressurised air. 22-Mar-19 09:10 AM (as train brakes do, but no relation between both brakes) 22-Mar-19 09:10 AM in any case 22-Mar-19 09:10 AM got a job victory dance 22-Mar-19 09:10 AM Also, pay is good: 1400€ for starters, for the zone, it's awesome, I was expecting something around 900€ 22-Mar-19 09:10 AM I expect it to go down to around 1250 or something when I raise the tax percentage. (when they first hire you, the tax is the minimum 2%, I shall raise it to 13% if things go well. 22-Mar-19 09:10 AM Still, that's the same pay I had in Barcelona, so it's excellent for me. 22-Mar-19 09:10 AM Start is at 7am, finish at 4pm, wich I pretty much like. 22-Mar-19 09:10 AM (I guess it has about half an hour in between those to eat) 22-Mar-19 09:10 AM (in spain, main meal is around 2pm) 22-Mar-19 09:17 AM wait 22-Mar-19 09:17 AM 2 to 13 % tax?! 22-Mar-19 09:17 AM yeah, what? 22-Mar-19 09:17 AM I pretty much like spains universal medical care. 22-Mar-19 09:17 AM money has to come from somewhere 22-Mar-19 09:17 AM The catch is that I prefer to pay 13, and have money returned to me at the end of the year. 22-Mar-19 09:17 AM than having to worry about paying taxes at the end of the year. 22-Mar-19 09:19 AM taxes here are 10 to 40%... 22-Mar-19 09:20 AM so? 22-Mar-19 09:20 AM you think it's low percentage, then? 22-Mar-19 09:20 AM yep 22-Mar-19 09:20 AM ah 22-Mar-19 09:20 AM lower than expected 22-Mar-19 09:21 AM well, we should take into account that the hirer, already pays taxes on me too. 22-Mar-19 09:21 AM all that is too complicated for me anyways 22-Mar-19 09:21 AM let's keep on topic (so topic speak) 22-Mar-19 09:21 AM XDDDD 22-Mar-19 09:22 AM USA is great, you have no idea what your taxes are because sure you might know what your rough federal will be, but then alllll the little things 22-Mar-19 09:22 AM uhg 22-Mar-19 09:22 AM XDDDDDDDDDDDD 22-Mar-19 09:22 AM this is why you must hire an accountant 22-Mar-19 09:22 AM or basically pay extra taxes 22-Mar-19 09:22 AM so he can run with your wife? 22-Mar-19 09:22 AM (wife, husband, partner) 22-Mar-19 09:22 AM that's what I'll do, pay extra and not worry about it. 22-Mar-19 09:22 AM then receive a letter with "you paid this X too much, here, have it back" 22-Mar-19 09:23 AM so you want to lose thousands of dollars a year because you didn't fill out all the proper tax forms? 22-Mar-19 09:23 AM oh hahaha 22-Mar-19 09:23 AM no thats not how it works 22-Mar-19 09:23 AM you won't get it back if you don't do the right stuff 22-Mar-19 09:23 AM that's how it works in spain. 22-Mar-19 09:23 AM like right now for example 22-Mar-19 09:23 AM that much I do know. 22-Mar-19 09:23 AM I am renting out two rooms to room mates 22-Mar-19 09:23 AM if I just pay the tax on the income I lose that money 22-Mar-19 09:24 AM aha 22-Mar-19 09:24 AM if I claim the tax, write off the square footage as a % of the total of the house, then take that % and apply it to all my utilities, repair costs, etc on the house, then file that under some other forum, then I get some of that money back 22-Mar-19 09:24 AM they make it complex so you HAVE to hire an accountant or a company like turbotax to do your crap 22-Mar-19 09:24 AM like litterally, companies like HRBlock and Turbotax pay the government to keep the tax code complicated 22-Mar-19 09:24 AM they would be out of buisness if the goverment spent the time to make a fancy website that everyone can just go and fill out and be done their taxes 22-Mar-19 09:25 AM Woah 22-Mar-19 09:26 AM anyway, going to kill this political speak now 22-Mar-19 09:26 AM poof its dead 22-Mar-19 09:26 AM but it is stupid 22-Mar-19 09:26 AM I guess spain's tax can get complicated too if you own things and rent things and such, but I don't own anything apart from my motrbike (tax related) so I just have to care about that 2 to 13% increase. 22-Mar-19 09:26 AM okay 22-Mar-19 09:26 AM anyways 22-Mar-19 09:26 AM I 22-Mar-19 09:26 AM GOT 22-Mar-19 09:26 AM A 22-Mar-19 09:26 AM JOB 22-Mar-19 09:26 AM YAY! 22-Mar-19 09:26 AM (damn I'm still shaking) 22-Mar-19 09:26 AM best part is that I pretty much liked the main boss persona and attitude. 22-Mar-19 09:26 AM so it's a win/win 22-Mar-19 09:28 AM awesome 22-Mar-19 09:28 AM if they fabricate machinery, I guess that at a minimum they'll have plasma cutting. Wich, if I perform in my duties, I can probably ask to buy machine time. 22-Mar-19 09:28 AM (I always want to pay for that) 22-Mar-19 09:28 AM yeah! also the main engineer seemed cool too 22-Mar-19 09:28 AM fun conversation: 22-Mar-19 09:28 AM Boss: You'll get a medical exam. Me: Yeah, I don't smoke nor drink, and I sport, so I should be good with that. Both: Laughter. Boss: Yeah, you'll totally nail it. 22-Mar-19 10:51 AM congratulations! \o/ 22-Mar-19 11:47 AM Wooottt found an ISO63 to CF 4.5" adapter 22-Mar-19 11:47 AM https://www.ebay.com/itm/254153745023 22-Mar-19 11:47 AM So hopefully soon (tm) I'll have the turbo-V70 spun up yayyy 22-Mar-19 11:51 AM Nice! 22-Mar-19 11:52 AM Don't have a centering ring and clamps though... Dunno if I want to get something from hongkong new or something used from the US for about the same price... Hrm... 22-Mar-19 11:52 AM I do have 4.5" conflat to 8" conflat so I can theoretically kinda get my big chamber together, but I also have a 4.5" viewport, I think I will try to use that first because I'd love to see the turbo spinning up :) 22-Mar-19 11:52 AM Also that turbo would be a bit small for the larger chamber 22-Mar-19 11:52 AM I mean it would work but it would take quite awhile to pump down 22-Mar-19 12:02 PM Do you know the pumping speed? 22-Mar-19 12:08 PM 65 l/s 22-Mar-19 12:08 PM its a small pump heh 22-Mar-19 12:08 PM still looking for an ISO 160 to CF adapter for my large 690 l/s turbo :) 22-Mar-19 12:27 PM Nice. 690 will get you far fast, my main pump is a 600 l/s. One day I'd like to install my 1200 l/s, but I don't have the power to run it with everything else for now. 22-Mar-19 12:27 PM aw man, I'd have had a little sputter chamber if I had kept that T... I just found a 4.5" to 6" CF adapter for not a terrible price LOL 22-Mar-19 12:27 PM But I can also use that with my larger chamber too hrm 22-Mar-19 12:27 PM might get it to have, because having any which adapter around is really handy lol 22-Mar-19 12:27 PM yea I nabbed it, why not 22-Mar-19 12:27 PM tbh I was designing my process around 8" conflat because I thought the most commonly available cheap wafers were 6" anymore... new that is... 22-Mar-19 12:27 PM but Nixie found that company that does 2" and 4" as-well so I can start thinking about other sizes 22-Mar-19 12:27 PM honestly it would be neat to do a bunch of 4.5" conflat stuff but its kinda a step-child size... don't see it too often, but its not as bad as like 3.33" 22-Mar-19 12:33 PM The 3" stuff is just awful lol 22-Mar-19 12:33 PM ikr? 22-Mar-19 12:33 PM its like oh hey a really large neat piece of conflat 22-Mar-19 12:33 PM oh it has 3" stuff 22-Mar-19 12:33 PM rip 22-Mar-19 12:34 PM Our new accelerator is still using that standard. Why tf would it be designed with it still, ends up being less common and more expensive lol, especially for beamlines. 22-Mar-19 12:34 PM Btw, if you want the tee back, let me know. You were generous enough to sell it to me in the first place lol 22-Mar-19 12:35 PM well if your buying new I'd think its not a problem? companies still make 3" stuff new... 22-Mar-19 12:35 PM but if your going to be trying to piece something together from used parts yea there is no point 22-Mar-19 12:35 PM and nah its yours, perform science 22-Mar-19 12:35 PM if you ever scrap the whole project or tear it down, let me know, i may be interested in buying it back or something 22-Mar-19 12:35 PM I assume you'd let people know here if you were going to sell stuff though :P 22-Mar-19 12:39 PM Oh yeah lol, il post here first if I ever sell anything 22-Mar-19 12:53 PM Though I don't think I will tear down this project (as long as it works). This is a really long term research system, I'd like to see it go for many, many years. Though I can always help others build them lol. Who knows, maybe one day il build cheap accelerators to sell lol 22-Mar-19 01:19 PM I am planning on HOPEFULLY having a lathe by next month that can handle up to 9" stock so once I get that hopefully I can start helping make more custom bits and bobs 22-Mar-19 01:19 PM stock will be the expensive/hard part, I haven't really dug around the surplus place yet, but hopefully they have some good stock for cheap 22-Mar-19 01:19 PM if the lathe I'm looking at is still posted by next month when I have the money 22-Mar-19 01:25 PM Nice! A lathe would be amazing to have, even a small one 22-Mar-19 01:41 PM Yea this is a benchtop one, an old south bend, but it'll be good for making some custom parts, especially standard ISO stuff. 22-Mar-19 01:41 PM I'll challenge myself with conflat someday, especially if I find some cheap SS stock 22-Mar-19 01:41 PM benchtop 9"? 22-Mar-19 01:42 PM yea its interesting, here leme link it 22-Mar-19 01:42 PM a benchtop lathe that can swing around 9" pieces????????? 22-Mar-19 01:42 PM https://www.ebay.com/itm/South-Bend-9-inch-Model-A-Engine-Lathe/143176093485 22-Mar-19 01:42 PM I mean, its a BIG BENCH TOP 22-Mar-19 01:42 PM and you'd want something pretty damn sturdy to put it on 22-Mar-19 01:42 PM especially big considering the back belt part... 22-Mar-19 01:42 PM But yea its a nice inbetween 22-Mar-19 01:42 PM compared to the tiny chinesium stuff and the standard standing lathe 22-Mar-19 01:42 PM this will be easy to go pick up 22-Mar-19 01:42 PM and the model A was a SUPPPERRR common lathe 22-Mar-19 01:42 PM they made bajillions of them 22-Mar-19 01:42 PM so there are parts all over 22-Mar-19 01:44 PM Sweet 22-Mar-19 01:44 PM never heard of it 22-Mar-19 01:44 PM its an american brand 22-Mar-19 01:44 PM I don't quite like it, but it's nice. 22-Mar-19 01:44 PM in Aus they rebadged it as something else, so if it sold in europe it may have a different name as-well 22-Mar-19 01:44 PM what don't you like? 22-Mar-19 01:44 PM looks like any american lathe to me 22-Mar-19 01:45 PM the belt drive first. 22-Mar-19 01:45 PM well sure, you can't get all the features in an old cheap lathe 22-Mar-19 01:45 PM you can always VFDafy the motor 22-Mar-19 01:45 PM well, my lathe doesn't have gearbox, that one does, wich is a nice feature. 22-Mar-19 01:45 PM yea, its really nice to have a gearbox 22-Mar-19 01:46 PM however, it only does imperial measurements, right? 22-Mar-19 01:46 PM (at least with my gears I can do both, but that's minor) 22-Mar-19 01:46 PM I am not entirely sure? 22-Mar-19 01:46 PM me neither 22-Mar-19 01:46 PM don't take my word for it 22-Mar-19 01:46 PM I mean I'd assume there are crossover points or something 22-Mar-19 01:47 PM inspect the ways as good as you can 22-Mar-19 01:47 PM and either way, its a feature I probably won't use super often? I am not sure lol 22-Mar-19 01:47 PM mmm...not sure if you are going to use it or not, being in US 22-Mar-19 01:47 PM (requiring metric pieces, I mean) 22-Mar-19 01:47 PM but it's handy to have. 22-Mar-19 01:48 PM absolutely, I love using metric for stuff I make, but yea oh well 22-Mar-19 01:48 PM anyway, I dunno how much "inspection" I'll get 22-Mar-19 01:48 PM I could contact the guy, see if I can drive the hour and a half out to inspect before buying, but if someone freaking buys it now on Ebay on my trip out there its like 22-Mar-19 01:48 PM welp 22-Mar-19 01:48 PM that was a great waste of time 22-Mar-19 01:48 PM it apparently has 16 watchers now 22-Mar-19 01:48 PM thats a great price for a lathe 22-Mar-19 01:48 PM oh 22-Mar-19 01:48 PM and its not a PITA to transport like other standard lathes would be 22-Mar-19 01:48 PM so it has some activity 22-Mar-19 01:49 PM well, if it's not this one, it will be a different one. 22-Mar-19 01:49 PM its probably going to be a matter of, buying it and just yoloing it 22-Mar-19 01:49 PM XDDDDDDDDDDD 22-Mar-19 01:49 PM its at-least not rusted badly, and even if there is wear in the ways, that is theoretically repairable afaik 22-Mar-19 01:49 PM but I can also work around it 22-Mar-19 01:49 PM I dunno I think it looks in pretty good shape for the money, I have seen people on youtube restoring machines where its covered in rust haha 22-Mar-19 01:55 PM yeah 22-Mar-19 01:56 PM hrm maybe I'll try to wrangle that this weekend 22-Mar-19 01:56 PM I have to evaluate my monz 22-Mar-19 01:56 PM Still paying off a credit card from the SEM adventure lol 22-Mar-19 02:32 PM XDDDDDDD 22-Mar-19 02:32 PM You are going to need to rearrange the workshop again 22-Mar-19 02:32 PM (wich reminds me that with the prospective pay of the job, I might end with a proper worksop much sooner than expected). 22-Mar-19 03:49 PM oh jeez I bought this incase I needed it for something... and I don't think I will 22-Mar-19 03:49 PM https://www.ebay.com/itm/2-75-Conflat-Flange-Cap-with-3-4-Copper-Tube/123641575646 22-Mar-19 03:49 PM but I didn't read the description... it came with 3 of them!! 22-Mar-19 03:49 PM for 18 bucks shipped... wth XD 22-Mar-19 04:10 PM I mean, getting it to copper line is extremely handy, gives you a link to standard "consumer" stuff 22-Mar-19 04:10 PM now you'll be HVAC compatible! 22-Mar-19 09:29 PM I mean these actually have SS or Aluminum rings silver soldered? to the end of the copper... so kinda not really 22-Mar-19 11:01 PM Tonight is quite the night of rework 22-Mar-19 11:01 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190322_194242-C710A.jpg 22-Mar-19 11:01 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190322_230002-E05F2.jpg 22-Mar-19 11:16 PM Bench so pretty! 23-Mar-19 03:27 AM I just bought the 10KV power supply. 23-Mar-19 03:27 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Fuente-de-alimentaci-n-de-alto-voltaje-con-A980E.png 23-Mar-19 05:42 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-14ACC.jpg 23-Mar-19 05:42 AM Very big and ostensibly well made Chinese CO2 laser HV supply 23-Mar-19 05:42 AM Designed for 100W (optical power) I think 23-Mar-19 05:50 AM Supposedly 50kV 35mA 23-Mar-19 05:50 AM Now, I assume these 3 big potted transformers have diodes inside like a TV fly back 23-Mar-19 05:50 AM The HV just goes in “series” from one transformer to the next then to the HV output 23-Mar-19 05:50 AM The “start” does appear to just go to ground 23-Mar-19 05:50 AM So I’m wondering if it’s reversible and I can get negative HV from it 23-Mar-19 05:50 AM Except for the four blue primary wires the HV transformer board is a completely separate PCB 23-Mar-19 07:01 AM Joined the server. 23-Mar-19 12:11 PM Woah 23-Mar-19 12:11 PM Welcome! 23-Mar-19 06:11 PM kewl found a 4.5" to 2.75" conflat adapter, so I can now coberfobble a 2.75" conflat chamber using ISO63-CF4.5-CF2.75 lol 23-Mar-19 06:24 PM Since I have like 3 2.75" conflat 4 ways I can actually attach quite a bit of things and start performing some experiments. I even have a single 2.75" conflat viton ring so I can use that for semi quick access to the chamber. 24-Mar-19 12:24 AM Do those viton gaskets just go onto normal knife edge CF flanges? And you can use them repeatedly? 24-Mar-19 02:21 AM moin! 24-Mar-19 02:25 AM moin 24-Mar-19 03:01 AM Cloin! 24-Mar-19 05:41 AM groin! 24-Mar-19 07:16 AM @a_quiet_scientist yes, the viton conflat gaskets are specifically designed to mate into the corresponding size cf flange. They are flat with beveled edges that match the angle of the knife edges, and can be used repeatedly 24-Mar-19 07:16 AM Here is a cad model cross section I did of the interference fit between a cf viton gasket and cf flange knife edges for reference: 24-Mar-19 07:16 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Conflat-Knife-Edge-Mating-Profile-with-Vit-D35C3.jpg 24-Mar-19 12:14 PM Oh man, conflat dealer came through with something interesting... 24-Mar-19 12:14 PM Know how I got two cryo compressors recently? 24-Mar-19 12:14 PM https://i.ebayimg.com/images/g/08MAAOSwbRRcl666/s-l1600.jpg 24-Mar-19 12:14 PM He has this 24-Mar-19 12:14 PM Which is an older tiny baby cryo head 24-Mar-19 12:14 PM like only conflat 6" lol its so cute 24-Mar-19 12:14 PM This is an RPK 500 model, and I can only find info on RPK 800/1500/3000 24-Mar-19 12:14 PM which are all much larger 24-Mar-19 12:14 PM I think this little one only requires a tiny compressor lol 24-Mar-19 12:14 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-2D343.png 24-Mar-19 12:14 PM one of the larger models, that cable apparently goes to their compressor... Not sure what its for... 24-Mar-19 12:14 PM It looks like it may only be like 2 freaking pins lol 24-Mar-19 12:14 PM OH lol 24-Mar-19 12:14 PM 21 Motor 220 V; 50/60 Hz 24-Mar-19 12:14 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-34CF0.png 24-Mar-19 12:14 PM so its just 220V for a motor in the head side 24-Mar-19 12:14 PM easy peezy 24-Mar-19 03:37 PM Moin 24-Mar-19 03:37 PM Wish I could find an affordable small turbo that ships internationally 25-Mar-19 01:29 AM Moin! 25-Mar-19 01:59 AM what would be "affordable" for you? 25-Mar-19 02:36 AM So unstable image. What type of artifact was it? 25-Mar-19 02:37 AM no it was stable, but messed up 25-Mar-19 02:37 AM I haven't seen it get that far 25-Mar-19 02:37 AM the controls don't show simple stuff like vacuum levels 25-Mar-19 02:37 AM since it's supposed to be so "easy" to use 25-Mar-19 02:37 AM I guess 25-Mar-19 02:37 AM Yeah without seeing what it is I wouldn't be too worried 25-Mar-19 02:37 AM so I wasn't sure if it wasn't getting good vacuum and preventing the HV startup 25-Mar-19 02:37 AM but I didn't have a water cooler and was changing buckets of cold tap water 25-Mar-19 02:38 AM Honestly the t200 was a very low end system... 25-Mar-19 02:38 AM which I also read could mess with the diff pump oil 25-Mar-19 02:38 AM and cause it to not achieve the proper temp, thus vac 25-Mar-19 02:38 AM well the manual says 5nm spot 25-Mar-19 02:38 AM Calling bull on that... 25-Mar-19 02:38 AM er, maybe 10nm 25-Mar-19 02:39 AM By maybe an order of magnitude 25-Mar-19 02:39 AM ctrl-f "10 nm" richardandersson.net/wp-content/uploads/2015/02/FullManual_small.pdf 25-Mar-19 02:39 AM Nah cold water is not going to be a problem 25-Mar-19 02:39 AM "10 nm (100 A) at 25 kV and 20 rom working distance." 25-Mar-19 02:39 AM Yeah I'm sure the manual says that, but it's not a practical number 25-Mar-19 02:39 AM 20 mm* 25-Mar-19 02:40 AM At least not for a scope that old 25-Mar-19 02:41 AM I don't see why they'd lie... seems like they'd have been caught quickly and lost credibility 25-Mar-19 02:41 AM it has an old Intel badge on it... so either Intel bought junk and then got rid of it soon, or they didn't buy junk 25-Mar-19 02:41 AM Anyways, for a dif pump I'm way more worried about it getting to warm than to cold 25-Mar-19 02:42 AM moin 25-Mar-19 02:42 AM now i have a ds 130 25-Mar-19 02:42 AM (in the trailer) 25-Mar-19 02:43 AM When it was manufactured it was probably capable of that at the factory 25-Mar-19 02:43 AM btw is scope blabla off topic? 25-Mar-19 02:43 AM so doesn't that just mean it's a cleanup away, or control electronics upgrade away... or a new emitter or some sort of aperture? 25-Mar-19 02:43 AM @N00N you mean like this https://www.pdx.edu/surplus/node/1494 25-Mar-19 02:45 AM But if you look at service contracts that not what they would service it too 25-Mar-19 02:47 AM @nmz787 yep but more like @Conmega s 25-Mar-19 02:53 AM Congrats on the ds130! 25-Mar-19 02:54 AM tnx 25-Mar-19 02:54 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-64DA2.jpg 25-Mar-19 02:54 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-4AB15.jpg 25-Mar-19 02:58 AM Nice! With the STEM detector! 25-Mar-19 02:58 AM yep 25-Mar-19 02:58 AM Is it a 130 or a 130C? 25-Mar-19 03:00 AM hum dunno 25-Mar-19 03:00 AM Did you sucure the vibration isolation stage? 25-Mar-19 03:00 AM yep 25-Mar-19 03:00 AM It will say on the control panel 25-Mar-19 03:00 AM Nice 25-Mar-19 03:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-CB2CF.jpg 25-Mar-19 03:02 AM it says 130 right? 25-Mar-19 03:03 AM Yup 25-Mar-19 03:03 AM System looks like it's in great shape 25-Mar-19 03:05 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-BAC91.jpg 25-Mar-19 03:05 AM ok 25-Mar-19 03:05 AM That's very clean for a scope of that age 25-Mar-19 03:08 AM ah ok 25-Mar-19 03:08 AM now ive to clean up a place for it 25-Mar-19 03:09 AM Did we just forget about voice chat today? 25-Mar-19 03:19 AM huh? 25-Mar-19 03:19 AM do you mean yesterday? 25-Mar-19 03:19 AM *yesterday 25-Mar-19 03:19 AM I was there, so was nixie and a couple of others 25-Mar-19 03:19 AM Was there an @ everyone ? 25-Mar-19 03:20 AM nope, forgot about that 25-Mar-19 06:11 AM @N00N Congrats on the scope! Yours looks in significantly better shape than mine was, and we and Adam were able to get it going in a few days so I'm sure you'll have that thing running in no time. Hope you have a water chiller and shop air :) 25-Mar-19 06:24 AM That cryo pump is on my way, now I just need to bite the bullet and buy 150 dollar freaking cryo hoses 25-Mar-19 06:24 AM https://www.ebay.com/itm/LOT-of-2-CTI-Cryogenics-Pressurized-Helium-Hose-8081271-P02/332812336425 25-Mar-19 06:24 AM like these uhg 25-Mar-19 08:42 AM Oh and I need a 3 phase motor to turn into a 3 phase converter lol 25-Mar-19 08:51 AM VFD 25-Mar-19 08:51 AM They're cheap enough 25-Mar-19 08:52 AM erm... I wouldn't trust running a cryo compressor of a VFD 25-Mar-19 08:52 AM its a 3 phase compressor, I don't think its going to like the output of a VFD... nor would I trust it 25-Mar-19 08:52 AM also I should be-able to get like a 3 phase motor for less than 100 bucks and make it a 3 phase converter 25-Mar-19 08:52 AM which I think a VFD big enough will cost way more than that 25-Mar-19 08:52 AM yea totally not spending hundreds of dollars on a VFD 25-Mar-19 09:35 AM XDDDDDD 25-Mar-19 10:16 AM @Conmega yeah, but the user interface console PCB is pretty fckd up 25-Mar-19 10:16 AM but i hope i'm able to fix it 25-Mar-19 10:43 AM She is up an running, unfortunately the fillament is broken. Fortunately we have found a source. Thank you @AdamMcCombs for the help. 25-Mar-19 10:43 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20190325_183628-33415.jpg 25-Mar-19 10:48 AM Awesome! 25-Mar-19 10:48 AM Cute little machine :) 25-Mar-19 10:53 AM At first glance I thought it was a label printer LOL 25-Mar-19 10:53 AM https://www.safetylabelprinters.com/images/labeltac9.jpg 25-Mar-19 11:51 AM I want to see the insides of that SEM 25-Mar-19 11:54 AM @Nixie look at the docs for it, probably has some cut-aways? 25-Mar-19 12:44 PM True, will check. 25-Mar-19 12:55 PM Anyone knows how these perform? 25-Mar-19 12:55 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/HTB14OCSSXXXXXaIXFXXq6xXFXXXM-01D8E.png 25-Mar-19 12:55 PM These types are aout 200€ 25-Mar-19 12:55 PM more conventional types are around 700€ in aliexpress. 25-Mar-19 12:56 PM What are you trying to see? Do you want a scope for slides or for things more like dissecting? 25-Mar-19 12:57 PM it all depends on the optics, which you'd likely need to find direct reviews for 25-Mar-19 12:57 PM There are models with XY stage for 300€ 25-Mar-19 12:57 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/HTB1YioaJVzqK1RjSZFvq6AB7VXaU-42157.png 25-Mar-19 12:57 PM For the chips 25-Mar-19 12:57 PM does it mention the word "plan" or "apo" ? 25-Mar-19 12:57 PM I can't see well with a normal microscope 25-Mar-19 12:57 PM as light bounces off weirdly 25-Mar-19 12:57 PM https://es.aliexpress.com/store/product/1-set-Industry-Handheld-Portable-Metallographic-Microscope-Zoom-100X-400X-Polarizing-Light-Microscope-Magnetic-Base-Polarizer/3200040_32983055457.html?spm=a219c.search0104.3.74.430c33b5TFyKUG&ws_ab_test=searchweb0_0,searchweb201602_2_10065_10068_10547_319_10891_317_10548_10696_10084_453_454_10083_10618_10307_10820_10821_10301_10303_537_536_10902_10059_10884_10887_321_322_10103,searchweb201603_35,ppcSwitch_0&algo_expid=a84b54b4-47f3-4d6f-9780-97e16ca42a75-12&algo_pvid=a84b54b4-47f3-4d6f-9780-97e16ca42a75 25-Mar-19 12:57 PM (it's in spanish, sorry) 25-Mar-19 12:57 PM Not that I can see 25-Mar-19 12:57 PM It includes a C-type adaptor, so I can put a camera, wich is a plus. 25-Mar-19 01:01 PM when you say light bounces around all weird, you're just interested in that for it's shroud sort of thing? 25-Mar-19 01:02 PM no, I mean. I have a small microscope, but when I want to look at the oxide etchings or metal depositions, and I bounce light from a flashlight, it is extremely difficult to actually see properly. This, on the other hand, has a special mirror that makes the light be confocal with the view, giving a clear picture. 25-Mar-19 01:02 PM I think 400X should be enough for the chips I'm going to do. 25-Mar-19 01:04 PM is that sort of like a condenser for the light source, but coming from above, rather than below? 25-Mar-19 01:04 PM sort of, I guess. 25-Mar-19 01:10 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1770-61205.jpg 25-Mar-19 01:10 PM Yesss one step closer to running a turbo. 25-Mar-19 01:15 PM nice! 25-Mar-19 01:22 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1772-BE1A4.jpg 25-Mar-19 01:22 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1771-FC6E2.jpg 25-Mar-19 01:22 PM Mmm nice and shiny clean. 25-Mar-19 01:25 PM touches the inside 25-Mar-19 01:27 PM don't do this, only villains do this 25-Mar-19 01:28 PM https://giphy.com/gifs/YwOFosmTM0Vag 25-Mar-19 01:38 PM XDDDDDDDDDDDDDDD 25-Mar-19 01:51 PM nice 25-Mar-19 05:20 PM cute little desktop SEM from 1973 25-Mar-19 05:20 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/lWCmu4Rl-1E6AE.png 25-Mar-19 05:31 PM Cute 25-Mar-19 06:01 PM @Koelzer well to answer your question - what’s the cheapest I can reasonably expect a second hand turbo ? 25-Mar-19 06:01 PM I should find an excuse to use the smol Hitachi desktop SEM at the lab, I’ve never used one 25-Mar-19 06:01 PM Well I do have an excuse to use a SEM just have to get around to it 25-Mar-19 06:01 PM I really want to use a FIB one day too, they’re neat 25-Mar-19 08:24 PM I'd say 200 bucks all in total for the cheapest turbo that has a chance of running... 25-Mar-19 08:24 PM But that's going to be one heck of a hunt on Ebay... 25-Mar-19 08:24 PM Ive been keeping a sharp eye on ebay for the last year or two on and off and got this turbo V70 for 110 bucks shipped and I had spent 100 bucks on a turbo v200 controller back awhile ago before I didn't receive a Turbo V200 in the mail like I was supposed to so yeaaa.... Going to adapt that because the real V70 controllers are like 200-500 commonly so I'd probably have gone the route of adapting a cheap v200 controller anyway. 25-Mar-19 08:24 PM Reasonably you can get a decent turbo for like 300-400 once or twice a month. 25-Mar-19 08:24 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1779-2B6C4.jpg 25-Mar-19 08:24 PM Also Yay conflat 25-Mar-19 08:53 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1780-B8AD8.jpg 25-Mar-19 08:53 PM Preperations for the smol chamber are coming along nicely. 26-Mar-19 12:24 AM That baby smol turbo! I love it 26-Mar-19 12:24 AM I’ll allow myself $300USD and go hunting 26-Mar-19 12:24 AM I’m comfortable with hundreds of dollars but looking at some new turbo prices they are scary - like nearly 10k 26-Mar-19 05:39 AM Check #swap-meet I had found a V70 with controller for like 300-400 range it was I think? That I had found on ePay it sjould still be posted. 26-Mar-19 06:22 AM Ah sorry it looks like that turbo sold for 425 winning bid, a bit above your price range 26-Mar-19 06:22 AM I'll try to DM you turbos in your pricerange when I find them 26-Mar-19 06:23 AM well, DHL says sshipping germany - australia is up to 10kg around 65€. so you would have around 200€ for the actual turbo, hard but not impossible 26-Mar-19 06:23 AM if you find one that suits you, I could arrange shipping to australia 26-Mar-19 06:25 AM I think @a_quiet_scientist is in the 'Murica landz 26-Mar-19 06:26 AM IIRC he is Luke Weston from twitter, so an aussie? 26-Mar-19 06:30 AM ah, I haven't really put everyone 1-1 on twitter/here yet so you may be right... 26-Mar-19 06:30 AM hrm... 26-Mar-19 06:30 AM I know a guy in Australia that has friends at a scrap place and he mayyyy be getting a large machine to tear down for fun soon and that "mayyyy" have some HV equipment on it. 26-Mar-19 06:30 AM With low hours too, so I may be-able to have you buy something from him (I planned to pay shipping to get stuff over to the US but if some of it can be used in Aus, lets go for that) 26-Mar-19 06:32 AM mayyyy * mayyyy = unlikely? XD 26-Mar-19 06:32 AM but yeah, that sounds pretty nice 26-Mar-19 06:38 AM I dunno, its a CD pressing machine, which from the process I looked up on the googlerz requires some HV stuff 26-Mar-19 06:38 AM It sounded like he was going to try and get it, but it may end up being too big or the scrap yard might be a pain and refuse to let him have it, I dunno. 26-Mar-19 06:38 AM I'll let you all know what I know when I can. 26-Mar-19 10:35 AM Last month I've mentioned we (hackerspace Bitlair) was buying a SEM. We made an offer and the seller rejected the offer. Bid the asking price and never heard from him again. So at the moment I'm looking for a another SEM. I'm located in the Netherlands and will drive up to 500 miles to pick it up :) While browsing I've found loads of resources on SEM and still want one. Preferably one of the newer table top models. Running 98se/ME/XP and infested with WannaCry or without a software license is no problem. I'm better with computers than vacuum. But somehow they don't exist. It's either new for €100k+ or a SEM from 1980 or earlier. I'll keep an eye out. 26-Mar-19 10:36 AM You can always get a digital interface on the older SEMs... and generally the older SEMs are way better machines than any desktop model, and parts will be more commonly available, filaments cheaper, and more readily repairable 26-Mar-19 10:36 AM the desktop ones are really designed like consumer devices are nowadays... 26-Mar-19 10:36 AM you CAN fix a cellphone... doesn't mean you'd want to... 26-Mar-19 10:36 AM for example, column liner in my DS-130 can be cleaned... the column liner in a tabletop SEM will be a throw away part basically... 26-Mar-19 10:36 AM so you CAN clean it... but its small and going to be a REAL pain 26-Mar-19 10:36 AM I'd recommend and older larger unit if you can find the space for it, especially if your better with computers/electronics than HV 26-Mar-19 10:36 AM newer tabletop models A) require their software, so if the software is missing or doesn't have their license, have fun cracking the software or hunting for it... B) you really are going to hate a software interface, my machine has a bajjilion knobs on the panel and its way way way easier to work with than any GUI ever will be C) the electronics are going to hardly be user serviceable, because yea gals/pals/fpgas/rommed micros... you'll be SOL if one of those dies. The older machines, eh mostly 7400 series chips lol. 26-Mar-19 10:41 AM You are making a good point 26-Mar-19 10:41 AM But that's just some of my opinion, I can't help too much for Netherlands, since I don't live over there and I'm not sure about the landscape, but i know lots of good equipment shows up over there from people I know who collect vintage computers. Wish you a lot of luck, and don't just forget about the one you didn't get an accepted offer on... He might have it in 6 months/ a year from now, and may accept that offer then ;) 26-Mar-19 10:41 AM @AdamMcCombs can give more insight if he is ever not busy :P 26-Mar-19 10:41 AM I think he's been @'d here at-least 10 times today lol 26-Mar-19 11:15 AM :3 26-Mar-19 01:56 PM @AdamMcCombs Make it 11. 26-Mar-19 04:09 PM @jwrm22 Everything Connor says is right. There's some exceptions, but for the most part I like to stay completely analog. Exception would be an xl30 26-Mar-19 04:29 PM Joined the server. 26-Mar-19 04:29 PM Not sure how I left but ok 26-Mar-19 04:30 PM Welcome back 27-Mar-19 02:09 AM moin! 27-Mar-19 02:09 AM moin 27-Mar-19 02:19 AM Is it some kind of law for dosimeters to reach their dose alarm threshold only at night? 27-Mar-19 02:37 AM Oo 27-Mar-19 03:00 AM other than color-coded velcro cable ties, anyone have any tips on 'the art and zen of cable management'? I am dealing with about 30+ cables of various power, high voltage, and data (and probably some with mixed power+data) http://diyhpl.us/~nmz787/pdf/smi3200/pics.html#cables 27-Mar-19 03:00 AM BTW... I am seeing 2005 as the vintage of this FIB... pretty sweet! I can almost smell that "new car smell" 27-Mar-19 04:40 AM You can get tiny little plastic rings, cylinders that slip over the wire. 10 different colours, just like a resistor colour code, so you use a few rings to number every wire in the loom at every end 27-Mar-19 05:25 AM Not stainless. Black passivated bolt, 304 stainless washers, zinc plated nuts 27-Mar-19 05:25 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-4042F.jpg 27-Mar-19 05:25 AM Is this mixed approach going to be ok for conflats or poor? 27-Mar-19 05:25 AM 1/4” - 28 (UNF) btw 27-Mar-19 06:16 AM uhm I mean I'm ignorant, but I think anything that is the right sized bolt/washer/nut that clamps the conflat is ok... 27-Mar-19 06:16 AM @a_quiet_scientist its probably fine, I am using some long black set screws loctite to my aluminum 6" conflat adapter plate for clamping 27-Mar-19 06:16 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/High-Vacuum-Top-Plate-Assembly-3-1024x576-87167.jpg 27-Mar-19 06:16 AM just remember, if your using similar metal to similar metal for the bolt/nut, put some antiseize on it 27-Mar-19 06:16 AM otherwise your not going to have fun removing it 27-Mar-19 06:19 AM If you are worried, I second the antiseize idea, though it can make stuff really messy. I use non-metal molybdenum-disulfide Moly-Lit for some of my stuff 27-Mar-19 06:19 AM But those bolts you are using should probably be fine 27-Mar-19 06:20 AM LDS vacuum sells antisieze that comes in chapstick form, it looks pretty hard to make a mess off 27-Mar-19 06:20 AM just put some on the bolt, and while threading the nut on it should disperse 27-Mar-19 06:20 AM automotive anti-seize oh god yea that makes a mess every time guaranteed but oh man do those bolts come apart later <3 27-Mar-19 08:16 AM getting my last adapter I need for the turbo today, I'll be-able to hook to 2.75" conflat and build a little chamber. I unfortunately only have one 4.5" conflat ring atm used between a 4.5" viewport and a 4.5" to 8" adapter, so I'll have to try and re-use that, its doesn't look fully clamped so I may be-able to get another use out of it... if not I'll have to wait until I can get an order in from LDS vacuum with new rings... 27-Mar-19 08:16 AM I guess I should wait until the weekend anyway because I'll be getting the gauge for one of the HV sensors I have on saturday so eh 27-Mar-19 08:16 AM hrm 27-Mar-19 10:34 AM sigh cryo helium lines are sooo expensive 27-Mar-19 10:34 AM gona spend more on the hoses than on two helium compressors and cryo heads like jeeezz 27-Mar-19 10:34 AM unless I can find some laying around the surplus store where I bought the compressors from... 27-Mar-19 10:34 AM I haven't noticed any the last few times I've been there but I may not have looked in the right places 27-Mar-19 02:45 PM anyone here using something like this on their roughing lines? https://www.amazon.com/dp/B004XW6EL0 27-Mar-19 03:00 PM @jwrm22 , I have a tabletop model SEM. Don't have enough experience with it yet to offer much advice, but I can say the small size and minimal utilities required are nice. When I bought it, I just threw in in the backseat of a compact car. I think they're also usually designed to be easier to use, so depending on who would be using it, that might be something to consider. Hitachi TM-1000 shouldn't be too hard to find for about $20k USD. I bought my JCM-5000 Neoscope for $5k USD but it took me years to find a good deal. 27-Mar-19 03:09 PM @nmz787 I dunno why you would when the little MKS 901P transducers are 50 bucks on ePay all day long... So half the price and from an actual vacuum company. That looks like its designed for working on A/C units and such... and will need weird adapting and just... ehh 27-Mar-19 03:09 PM Also that only goes down to 0.02 Torr? 27-Mar-19 03:33 PM I already have one of those MKS probes 27-Mar-19 03:33 PM I ask because I think I saw something like it on Nixies compendium or hackaday 27-Mar-19 03:33 PM or maybe it was Thought Emporium 27-Mar-19 05:54 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1785-F0DE9.jpg 27-Mar-19 05:54 PM NW25 to NW16 4way right? :) 27-Mar-19 07:57 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1786-362FF.jpg 27-Mar-19 07:57 PM So uh yea adjusting the frequency on the turbo-V200 pump controller will be easy :) 27-Mar-19 07:57 PM lol 27-Mar-19 07:58 PM So yea most varian pumps are 54Vac and just a different current/freq 27-Mar-19 07:58 PM So like... For V70 pumps where controllers are far and few between... Get like a V200 controller for 50-75 bucks and have fun lol 27-Mar-19 07:59 PM Im going to wait until you make sure it works 27-Mar-19 08:00 PM Of course. I have no doubt I can get it going though... I mean worst case I may have to change another resistor in line since the pot may only go so far. 27-Mar-19 08:00 PM But with the range of frequency of the pot and resistance change I should beable to correlate that and the in line resistor to figure out the resistance to frequency ratio. 27-Mar-19 08:08 PM Yup uses a voltage to frequency converter chip. RC4151N which is a current part still from TI as the LM331 it does 1hz to 100khz.... 27-Mar-19 08:08 PM That will have the formula and I'll be set. This is easy. All of varian's controllers from the Era looked exactly the same. It'd make sense to share similar boards and just have option boards or more power capable drivers. 27-Mar-19 08:08 PM It's pretty modular in here. 27-Mar-19 08:08 PM So yea hurptie durptie this will be easy. Now whether I build a good chamber and my turbo has good bearings or not is a different story. 27-Mar-19 11:14 PM moin 27-Mar-19 11:30 PM good yawnrning 28-Mar-19 06:16 AM moin 28-Mar-19 09:12 AM Moing! 28-Mar-19 09:18 AM ohai nixie! 28-Mar-19 09:19 AM waves back with a very tired hand 28-Mar-19 09:19 AM ^^U 28-Mar-19 09:19 AM no, I don't want to know. 28-Mar-19 09:21 AM Uh...okay, I guess. 28-Mar-19 09:21 AM :-D 28-Mar-19 09:44 AM LOL 28-Mar-19 10:26 AM Question for all you vacuum hackers: Is a foreline trap crucial to protecting your turbo from oil back-streaming? Or is a long KF25 roughing line (3~4 FT, could theoretically add some KF40 lines to this too which are like 3~ FT each) decent enough to capture/condense most of the oil back-streaming? From what I have read the foreline filter is just SS/Copper/something swarf basically in a cylinder to prevent line of site to the other side and to condense?? the oil vapors on the cool metal surface? 28-Mar-19 10:47 AM Some if not most rotary vane pumps will dump all of their oil into the vacuum side if turned off under vacuum 28-Mar-19 10:47 AM unless yours has a special mechanism to prevent that I recommend a trap 28-Mar-19 11:10 AM hrm maybe I used the wrong termonology 28-Mar-19 11:10 AM I have an RV12 I plan to use, which has the backflow prevention mech 28-Mar-19 11:10 AM so does my Altcatel 2008AC I think actually, since all the major rebuild kits I saw specific mention including that part in the rebuild. 28-Mar-19 11:10 AM so that shouldn't be much of an issue, I'm just talking about oil backstreaming, aka like oil vapor slowly slowly migrating back into your process/upstream pumps/etc 28-Mar-19 03:10 PM well isn't the turbo specifically there to pump any molecules... including oil vapors? 28-Mar-19 05:11 PM uhm... right from the chamber, but as far as I know once the system is running for awhile its possible for oil vapor from the pumps inlet to migrate up and kinda start... coating things slowly... 28-Mar-19 05:11 PM I believe that's what a foreline trap is for, to help prevent that as much as possible. 28-Mar-19 05:11 PM I dunno @AdamMcCombs would probably just know but I figured I'd ask here first, ping him later :P 28-Mar-19 05:12 PM I use a foreline trap, mainly to prevent contamination of the diff pump oil from the roughing oil backstreaming 28-Mar-19 05:12 PM I have an fl20k foreline trap. Few usually floating on ebay pretty cheap 28-Mar-19 05:13 PM right ok, but how much oil backstreaming actually happens, how fast, and is it possible to simulate or create your own foreline pump? 28-Mar-19 05:13 PM oh there is one of those up atm, what do the refills on those cost specifically? 28-Mar-19 05:13 PM https://www.ebay.com/itm/Edwards-FL20K-Foreline-Trap-w-Rubber-Clamp-Valve-Connection-Seals-USA-SHIP/133000937310 28-Mar-19 05:14 PM Really cheap, I got 1lb of zeolite from lds 28-Mar-19 05:14 PM Like $25 28-Mar-19 05:14 PM That will last you quite a while 28-Mar-19 05:15 PM oh cool! 28-Mar-19 05:15 PM The kf25 ports, and removable basket is really convenient too 28-Mar-19 05:15 PM hrm I was looking at some foreline traps and they had metal swarf type material in it 28-Mar-19 05:15 PM I like this style much better 28-Mar-19 05:16 PM but yea I was asking how easy it is to make something like that since I have like... 6ft of KF40 hose now... LOL I could just litterally bend a hose down, fill it with that zeolite and profit??? 28-Mar-19 05:16 PM technically yeah lol 28-Mar-19 05:16 PM lets see if I got some pictures of when I was cleaning it 28-Mar-19 05:16 PM kinda trying not to spend money atm because I am waiting on tax refund, paying of a credit card from the SEM still, out the money I had to pay the accountant lol 28-Mar-19 05:16 PM cool, that would be helpful 28-Mar-19 05:19 PM Kind of crappy picture, I didn't really take a good picture of this when I was cleaning it (this was when I started way back a while ago before I decided to document stuff more seriously lol). Kind of can see some of the pieces of the basket in there 28-Mar-19 05:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/High_Vacuum_Foreline_Assembly_2-61476.jpg 28-Mar-19 05:19 PM Here is the datasheet for the trap as well: 28-Mar-19 05:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/FL20K_Foreline_Trap-037F1.pdf 28-Mar-19 05:26 PM cool thanks! alright looks fairly simple 28-Mar-19 05:26 PM I have a KF40/KF10 cross actually and two KF40>KF25 adapters 28-Mar-19 05:26 PM so I could probably make a foreline trap with that if I got despirate enough lol 28-Mar-19 05:27 PM Yeah its super simple. Just a basket that holds the zeolite in the center of a canister with kf flanges lol 28-Mar-19 05:27 PM Yeah, you could make one yourself pretty easy I think 28-Mar-19 05:27 PM Improvising with kf parts and filling with zeolite 29-Mar-19 11:05 AM moin 29-Mar-19 11:48 AM Nabend! 29-Mar-19 12:11 PM does moin == man? 29-Mar-19 12:11 PM or moin == morning ? 29-Mar-19 12:12 PM moin originated from the german "Morgen", which means "morning", but in many parts here they use it as an universal greeting, regardless of time 29-Mar-19 12:12 PM being from the U.S. it sounds like a ghetto exclamation 29-Mar-19 12:13 PM like latino 29-Mar-19 12:13 PM that might be more commonly written "meng" 29-Mar-19 12:14 PM I've never heard of that tbh 29-Mar-19 12:14 PM "sup meng" so I figured "sup moin" 29-Mar-19 12:15 PM ah, lol 29-Mar-19 12:15 PM https://www.urbandictionary.com/define.php?term=Meng 29-Mar-19 12:16 PM well, feels like most (active) users here are german anyways and due to timezone stuff we just kinda stuck with moin 29-Mar-19 12:16 PM ah, I shoulda looked it up https://www.urbandictionary.com/define.php?term=moin 29-Mar-19 12:16 PM etymology is diff than what you said tho 29-Mar-19 12:16 PM huh 29-Mar-19 12:16 PM I've been told it originated from morgen, but I'm not gonna argue with urban dictionary 29-Mar-19 12:17 PM oh, nevermind, the 'second' def says morning, but not from German 29-Mar-19 12:17 PM "People in more southern parts of Germany often mistakenly assume that Moin is a short from of Morgen (meaning "morning") and should be used like "good morning"." 29-Mar-19 12:17 PM haha, of course Urban Dict is right! 29-Mar-19 12:18 PM >>People in more southern parts of Germany often mistakenly assume that Moin is a short from of Morgen (meaning "morning") and should be used like "good morning". 29-Mar-19 12:18 PM tha explains a lot 29-Mar-19 12:18 PM whoops 29-Mar-19 12:19 PM what can folks recommend for a water vapor trap for compressed air? 29-Mar-19 12:19 PM my FIB says it wants nitrogen for valves and venting... but I know a local guy that just uses compressed air 29-Mar-19 12:19 PM and he's been fine for years 29-Mar-19 12:49 PM <0xDBFB7#9254> Joined the server. 29-Mar-19 12:49 PM Welcome 29-Mar-19 12:50 PM <0xDBFB7#9254> @GigaSquirrel Howdy! 29-Mar-19 12:51 PM no worries, the server is open for everyone ^^ 29-Mar-19 12:51 PM <0xDBFB7#9254> ah, cool! 29-Mar-19 12:57 PM @nmz787 you'll be fine on shop air, just yes make sure its dry. Any real dryer should be "ok" so long as its sized properly. Also they spec N2 because of the environment its probably run in. Also if it doesn't have any leaks it probably runs for months on a N2 cylinder and N2 is cheap 29-Mar-19 12:57 PM Its not like once the machine is up and running the valving should be changing too much, its just on bring up it'll be valving over and doing a lot of stuff 29-Mar-19 12:57 PM and since you won't be running it 24/7 (I assume) you'll be happier with shop air :) 29-Mar-19 04:48 PM hmm, the whole dyer sizing thing is a bit drawn out and boring 29-Mar-19 04:48 PM I do live in the PNW where it rains for 9 months 29-Mar-19 04:48 PM but also already have a dessicant air dehumidifier in the garage (shop) 29-Mar-19 04:48 PM yeah they usually spec N2 because it's just standard for semicon processing, not terribly reactive, relatively homogenous 29-Mar-19 06:51 PM it seems bizarre that my FIB has what seems to be an oil-gun permanently installed, I can only guess it's for lubing the various mechanical bits 29-Mar-19 06:51 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Y58xZoYG7z7F3-TF5tcSXux8Fy6KUJYcTSvv7Z0xyU-9CBCD.png 29-Mar-19 07:11 PM If you run on compressed air be sure to disconnect the vent line from the rest of the air system 29-Mar-19 07:11 PM You never want to vent with compressed air 30-Mar-19 01:18 AM @AdamMcCombs I know a professional FIB shop that's been using it for almost a decade for venting and valving, they don't do semiconductor work though, only FIB machining of mostly diamond, glass, and metals 30-Mar-19 01:18 AM @AdamMcCombs what's your reasoning/logic? 30-Mar-19 01:50 AM @nmz787 There is a massive risk of contamination, unless you have an incredibly robust clean dry air system it's usually better to not. Additionally most systems have provisions to disconnect the vent from the rest of the system and recommend you do so if configuring like that. 30-Mar-19 01:50 AM The regular water separator is definitely not enough to get the oil and moisture out before venting 30-Mar-19 01:59 AM well not all compressors use oil 30-Mar-19 01:59 AM mine for example has teflon piston rings 30-Mar-19 01:59 AM but I believe the shop I part-time for simply uses a dessicant pack in-line before the regulators 30-Mar-19 01:59 AM but again, I'l like to know your logic 30-Mar-19 01:59 AM I'd* 30-Mar-19 01:59 AM contamination in what sense? just rusting things? 30-Mar-19 01:59 AM I guess maybe he has his system only connected for valving and the pneumatic dampeners.... and just sucks in atmosphere for venting 30-Mar-19 01:59 AM but that would only skip the compressor, opting for the HEPA filtered operating room air 30-Mar-19 02:02 AM Oil is the big concern for venting, which is alleviate by oil free compressors of course. Even with a desicant pack though (unless it's a really massive one) it's still going to result in more moisture content than just filtered room air 30-Mar-19 02:03 AM but to what disaster? he regularly gets to 10-6 and lower pressures? 30-Mar-19 02:03 AM (sorry no ? at the end of that last sentence) 30-Mar-19 02:03 AM Yeah room air is fine 30-Mar-19 02:04 AM I'll have to ask him tomorrow if he knows whether he's using room air or compressed for venting 30-Mar-19 02:04 AM I could swear the second FIB he has was using compressed 30-Mar-19 02:04 AM since it wouldn't vent unless some valve was openend 30-Mar-19 02:04 AM (he had a leak somewhere and rather than finding it, just valved off an entire portion of the system) 30-Mar-19 02:06 AM Compressed might not degraded vacuum in the short run, but if any moisture condences a lot of the parts of em systems are straight iron and can rust very quickly 30-Mar-19 02:06 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181108_132952-845E2.jpg 30-Mar-19 02:06 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181108_133306-42F75.jpg 30-Mar-19 02:06 AM Air leaks on a system are bad news 30-Mar-19 02:06 AM This was on a system that had a regular air water separator and dual desicant stacks. It was a relatively minor air leak as well, but left un fixed this is what happens 30-Mar-19 02:08 AM well it's mostly his "parts FIB" which has had more electronics troubles than anything 30-Mar-19 02:08 AM but I will definitely check with him tomorrow 30-Mar-19 02:08 AM his air leak was causing his compressor to turn on like crazy 30-Mar-19 02:10 AM Yeah no that's really bad 30-Mar-19 02:10 AM he actually just had a service tech bring that machine down a week or two ago, doesn't want to sink any more cash into it 30-Mar-19 02:10 AM said he's sunk probably 30-40k over the last 6 years, with no work ever making up for it 30-Mar-19 02:11 AM Ouch 30-Mar-19 02:11 AM Ever got a beam on it? 30-Mar-19 02:11 AM oh yeah 30-Mar-19 02:11 AM even recently 30-Mar-19 02:11 AM but it seemed like the MDAC cards might have been bad, or a reference board 30-Mar-19 02:11 AM or the deflection amp, or the octopole 30-Mar-19 02:11 AM basically only the center of the image was half-decent, and changing focus made the whole circumference get all weird 30-Mar-19 02:11 AM and it wasn't symmetrically weird 30-Mar-19 02:11 AM I replaced the deflection amp main AC:DC supplies, which were supposed to give 150VDC+/- 30-Mar-19 02:11 AM but were putting out 243=/- 30-Mar-19 02:11 AM +/- 30-Mar-19 02:13 AM Yeah that will fry coils non uniformly 30-Mar-19 02:14 AM saw the MDAC cards had some browning on a protective plastic cover, but the tech said they often are fine getting too hot, at least for a little while 30-Mar-19 02:14 AM but the system debug/diagnostic program wouldn't get past something about the reference board not finding a reference 5V signal 30-Mar-19 02:14 AM so he was scratching his head, since the system obviously could get /some/ image 30-Mar-19 02:15 AM Ah the dreaded orange/red M&Ms 30-Mar-19 02:15 AM and a lot of other parts wouldn't actually allow HT to come up if the ref wasn't there 30-Mar-19 02:15 AM orange/red M&Ms? 30-Mar-19 02:15 AM Wait 30-Mar-19 02:15 AM This is a fib 200 isn't it 30-Mar-19 02:16 AM yeah 30-Mar-19 02:16 AM this was the card 30-Mar-19 02:16 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/1jcX6pjySXnd3jLDMS9uFfuBj8QLpAa6W_MSBpnzM3-DAB6C.png 30-Mar-19 02:16 AM Never mind that's a more recent thing 30-Mar-19 02:16 AM under that cover 30-Mar-19 02:16 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/90k44yhepigxT_adJw610LYc2DOUQvOyRx09EUjEJD-2C70F.png 30-Mar-19 02:16 AM ne5534na op-amps 30-Mar-19 02:21 AM It's hard to say what over volting a system like that will do precisely 30-Mar-19 02:22 AM yeah, they had a spare deflection amp and swapped that, and same image 30-Mar-19 02:22 AM anyway, do you know how they fill N2 cylinders? 30-Mar-19 02:22 AM like is the cylinder size based on atmospheric volume? 30-Mar-19 02:22 AM i.e. a CF80 tank, is that 80 CF atmospheric? 30-Mar-19 02:23 AM Yeah 30-Mar-19 02:24 AM cause my FIB chamber has got to be a good 2 or 4 CF 30-Mar-19 02:24 AM Wait 30-Mar-19 02:24 AM The cylinder itself will displace 80cf 30-Mar-19 02:24 AM But it's pressurized up to 2500psi 30-Mar-19 02:24 AM So the nitrogen inside will displace a lot more 30-Mar-19 02:25 AM uhhh, but at sea-level, if that all escapes, it will only fill 80 1 cubic foot balloons? 30-Mar-19 02:25 AM I guess I'm just wondering how often I will need to drag a heavy ass cylinder to the airgas store 30-Mar-19 02:25 AM damn, I should've called them earlier today 30-Mar-19 02:25 AM to see what sizes they normally carry and will swap out 30-Mar-19 02:29 AM No your right I'm thinking of cryo 30-Mar-19 02:29 AM I'm reading an 80CF weighs 58 lbs empty 30-Mar-19 02:29 AM not terrible, but not something I want to get into a habit of lugging 30-Mar-19 02:29 AM at least the gas shop is only 8 mins drive 30-Mar-19 02:29 AM Most labs I'm in use boil off of ln2 for vent 30-Mar-19 02:30 AM I think that's what the FIB shop I part-time at used to use 30-Mar-19 02:30 AM Venting with atmosphere is ok as long as you pump down again soon 30-Mar-19 02:30 AM hmm 30-Mar-19 02:30 AM but there's still the valving 30-Mar-19 02:30 AM Ion pumps are a different story 30-Mar-19 02:30 AM I'd rather avoid any rusting 30-Mar-19 02:30 AM Yeah 30-Mar-19 02:30 AM If you just don't have leaks you will be fine 30-Mar-19 02:30 AM different in what sense? by ion pumps you mean IGPs? 30-Mar-19 02:31 AM Yeah 30-Mar-19 02:31 AM Those hate to be vented with atmosphere 30-Mar-19 02:31 AM You can do it 30-Mar-19 02:31 AM doesn't any reasonably high-vac system have an IGP? 30-Mar-19 02:31 AM It's just not good 30-Mar-19 02:31 AM No it's mostly a Philips/FEI thing 30-Mar-19 02:31 AM They only use them on ion column and feg now 30-Mar-19 02:32 AM oh, this is a Seiko (now Hitachi) 30-Mar-19 02:32 AM Ion column you need it 30-Mar-19 02:32 AM well most e-beams are FEGs these days, right? 30-Mar-19 02:32 AM the new ones 30-Mar-19 02:32 AM Chamber vacuum not really 30-Mar-19 02:32 AM They can be 30-Mar-19 02:32 AM You can still get both 30-Mar-19 02:33 AM yeah the IGP on mine is at the top of the column, right near the source 30-Mar-19 02:33 AM Yeah, there is likely a column isolation valve 30-Mar-19 02:33 AM yeah probably 30-Mar-19 02:33 AM So you can vent just the chamber 30-Mar-19 02:33 AM the chamber seems to still be under vac, and I haven't powered it in almost 2 years of owning it so far 30-Mar-19 02:33 AM it also has a load-lock so you don't have to vent the whole chamber even 30-Mar-19 02:34 AM And if you do vent a igp with not n2 you can beak it out 30-Mar-19 02:34 AM got a second, smaller, turbo for that 30-Mar-19 02:34 AM Using N2 to vent also drastically decreases pump down time 30-Mar-19 02:35 AM I will have to open the source soonish, once I get it up and running, the source was at the end of its life 30-Mar-19 02:35 AM a professor told me how to refill them last week, basically just said you need to do it in vacuum, have a crucible with hot liquid gallium, hold the source from above with a few volts going through it to get it warm, then dip the source in the pool and it will wick up into the coil reservoir 30-Mar-19 02:35 AM I immediately had a use for @Nixie 's manipulator 30-Mar-19 02:36 AM Yeah, it's not the worst thing in the world 30-Mar-19 02:36 AM Just never ever thouch the tip... 30-Mar-19 02:37 AM well he actually said it isn't atomically sharp like on a FEG 30-Mar-19 02:37 AM No it's not that bad 30-Mar-19 02:37 AM mentioning you can make them yourself pretty easily 30-Mar-19 02:37 AM It's not actually field emission 30-Mar-19 02:37 AM well it is, just at the tip of the taylor cone 30-Mar-19 02:37 AM (I think) 30-Mar-19 02:37 AM Is yours a llim? 30-Mar-19 02:37 AM LMIS 30-Mar-19 02:38 AM So no storage coil or yes? 30-Mar-19 02:38 AM uhh 30-Mar-19 02:38 AM idk 30-Mar-19 02:38 AM what is that? 30-Mar-19 02:38 AM never heard that term in 5 years of FIB talk 30-Mar-19 02:39 AM It's a winding of wire that increases the capacity of the tip 30-Mar-19 02:39 AM you mean the Ga reservoir? 30-Mar-19 02:39 AM Early tips didn't have that, just used kinda a bead 30-Mar-19 02:39 AM I have no idea what Seiko used now 30-Mar-19 02:40 AM oh, I thought they all used a coil that got gallium wicked into the center 30-Mar-19 02:40 AM with a kink at one end where the emission started 30-Mar-19 02:40 AM I know it's all fei does now 30-Mar-19 02:41 AM that's what the 90s era FIB 200 does 30-Mar-19 02:41 AM But the really early stuff like a fib 600 sometimes didn't 30-Mar-19 02:41 AM hmm 30-Mar-19 02:42 AM I'm pretty sure they just swapped the new style source in on the old stuff though 30-Mar-19 02:42 AM ah, was gonna say this page shows 200 and 600 are compatible https://www.appliedbeams.com/gallium-lmis-for-fei-fib-and-fib-sem-systems.html 30-Mar-19 02:42 AM I honestly don't know much about the diffs between the various FIB columns that FEI has made 30-Mar-19 02:42 AM pre-lens/Magnum/Sidewinder/Tomahawk 30-Mar-19 02:42 AM I am just a few cables away from having my FIB all connected 30-Mar-19 02:45 AM Nice 30-Mar-19 02:45 AM By fib 600 I mean things like the 610 and 611 30-Mar-19 02:46 AM I guess I should vent the rough pump to the outside of my plastic-film room 30-Mar-19 02:46 AM Very early instruments 30-Mar-19 02:46 AM and then figure out N2 or if I want to get an air dryer 30-Mar-19 02:46 AM (dessicant) 30-Mar-19 02:46 AM Like completely rack mount stuff 30-Mar-19 02:47 AM yeah mine is all rack mount 30-Mar-19 02:47 AM but it's 2005 vintage 30-Mar-19 02:47 AM I'm talking large descrite analog boxes 30-Mar-19 02:47 AM mm 30-Mar-19 02:47 AM my compressor always seems to be able to drip some water from its tank drain... so I'm definitely hesitant to connect it in case it will cause rusting 30-Mar-19 02:47 AM especially when the bigger dessicant packs are like $80 30-Mar-19 02:49 AM If you don't have leaks you will be fine 30-Mar-19 02:49 AM I have had so many problems as a result of desiccant packs 30-Mar-19 02:49 AM The stuff ndegrades and gets stuck in leack valves causing vacuum leaks 30-Mar-19 02:50 AM hmm 30-Mar-19 02:50 AM so just forgo it altogether? (as long as I can vent from atmosphere?) 30-Mar-19 02:50 AM Just actuating valves won't cause problems even if you just have a basic air dryer 30-Mar-19 02:50 AM It's when you have a constant gas expansion of compressed air 30-Mar-19 02:51 AM this is the only air dryer I saw today https://www.harborfreight.com/compressed-air-dryer-40211.html 30-Mar-19 02:51 AM Like when you vent 30-Mar-19 02:51 AM mmm 30-Mar-19 02:51 AM Those are for high cfm loads like cnc 30-Mar-19 02:52 AM yeah I could tell 30-Mar-19 02:52 AM def seemed like overkill 30-Mar-19 02:52 AM If your pnumatcs are running right you should hardly use any air 30-Mar-19 02:52 AM is there some other option for drying, beside that or desiccant? 30-Mar-19 02:52 AM i.e. something I might be able to cobble together tomorrow? 30-Mar-19 02:52 AM it would be pretty fun to try flipping this thing on... though even just routing the rough pump to outside might take a bit of time 30-Mar-19 02:52 AM I might need to order a flange adapter or something I guess 30-Mar-19 02:54 AM Just a regular air water separator should be fine 30-Mar-19 02:54 AM oh 30-Mar-19 02:54 AM those are definitely available at Harbor Freight or Home Depot 30-Mar-19 02:54 AM If you don't have a leak you won't condense water 30-Mar-19 02:55 AM If you are getting any water in it it means you have a problem 30-Mar-19 02:55 AM So by not venting with compressed air you won't be running a high load, so you won't get any water condensing 30-Mar-19 02:55 AM hmm, ok, will have to check on where the air lines are all routed to tomorrow 30-Mar-19 02:55 AM there's a bunch of stuff for sure 30-Mar-19 02:56 AM Yeah if it's configured for N2 it's probably connected 30-Mar-19 02:56 AM An inline particulant filter is not a bad idea for vent if you are disconnecting it from the rest of the air system 30-Mar-19 02:57 AM yeah 30-Mar-19 02:57 AM You don't want dust causing a leak in a leak valve 30-Mar-19 02:57 AM especially since I am not in a cleanroom 30-Mar-19 02:57 AM diff question 30-Mar-19 02:57 AM what do you do about grounding? 30-Mar-19 02:57 AM the manual says to provide a 100ohm ground 30-Mar-19 02:58 AM Yeah they like to say that 30-Mar-19 02:58 AM from reading, I can't tell if they mean between the outlet and the grounding rod outside, or between the grounding rod and the soil elsewhere in the yard 30-Mar-19 02:59 AM There is non insignificant leakage current from the HV systems 30-Mar-19 02:59 AM It's a reference to the ground rod to ground 30-Mar-19 02:59 AM But 100ohm spec is more to sink noise 30-Mar-19 02:59 AM seems the national standard is 25 ohms 30-Mar-19 03:00 AM Yeah, 100 is just minimum 30-Mar-19 03:00 AM In many labs you can have a very noisy ground 30-Mar-19 03:00 AM So they just put that spec in to cover themselves 30-Mar-19 03:00 AM In my shop I run a reply massive/excessive grounding setup, but that's because I'm close to a massive source of RF noise 30-Mar-19 03:03 AM hmm, so you drove another rod in the ground? 30-Mar-19 03:03 AM More like another few rods and did a mesh field as well 30-Mar-19 03:03 AM hmm 30-Mar-19 03:03 AM how did you measure things? 30-Mar-19 03:03 AM My situation is unique though 30-Mar-19 03:03 AM I drove rods until the problem went away 30-Mar-19 03:03 AM Bit if you aren't near a truly astoundingly powerful RF source you will probably be fine 30-Mar-19 03:05 AM hmm, I guess I'll just give it a shot as-is then 30-Mar-19 03:06 AM Yeah as long as you are up to nec spec you should be good to go 30-Mar-19 03:06 AM Be sure to check transformer taps and ir drop 30-Mar-19 03:06 AM what do you mean? 30-Mar-19 03:06 AM I checked the transformer of the FIB 30-Mar-19 03:06 AM to make sure it was set on the right tap for the wall voltage (240V) 30-Mar-19 03:06 AM the breaker is a 30A, and the FIB specifies a 20A 30-Mar-19 03:07 AM Yeah that, and then see how much your voltage drops when under load 30-Mar-19 03:07 AM so I guess I need to swap to a lower breaker 30-Mar-19 03:07 AM ah, ok, can do 30-Mar-19 03:08 AM It should be fine, it's just part of my startup check list 30-Mar-19 03:08 AM I try to start a instrument with as few systems running as possible 30-Mar-19 03:08 AM I don't know how possible that is on your fib though 30-Mar-19 03:08 AM As I'm bringing systems up I don't want to be checking for all sorts of voltages while simultaneously making sure it's not going to crash a turbo 30-Mar-19 03:08 AM Every system I bring I check all the voltages associated with it, then check for ac ripple. 30-Mar-19 03:08 AM When I bring more systems online I go back and check voltages and ripple in case there is a load down problem 30-Mar-19 03:11 AM hmm 30-Mar-19 03:12 AM Then I periodically check during the first few hours in case I have a cap degrading 30-Mar-19 03:12 AM should I plug the PC and LCD panels into the free plugs on the power distribution unit? or just into another extension cord from a diff breaker? 30-Mar-19 03:12 AM I get really sensitive when bringing lenses and deflectors up 30-Mar-19 03:12 AM No get everything on the same circuit if possible 30-Mar-19 03:12 AM There is probably quite a bit of consideration given to ground loops 30-Mar-19 03:14 AM the power unit says 100VAC... so I guess I just have to give it a try since the PCs probably spec 120V +/- 10% 30-Mar-19 03:14 AM but maybe it's 20% 30-Mar-19 03:14 AM When bringing optics up I go coil by coil 30-Mar-19 03:14 AM What does the power unit power? 30-Mar-19 03:14 AM Everything? 30-Mar-19 03:15 AM pretty much everything except the HT, the turbos, the IGP 30-Mar-19 03:15 AM they are all slaved off of it tho 30-Mar-19 03:15 AM coming from 'normal' wall plugs it has 30-Mar-19 03:15 AM Ah I missed the part about pc 30-Mar-19 03:15 AM What is the pc interface to the scope? 30-Mar-19 03:15 AM the other rack mount units are also slaved off of the power unit, through bigger weirder connectors 30-Mar-19 03:15 AM basically a bunch of BNC cables, and a serial port, and ethernet 30-Mar-19 03:16 AM Hm 30-Mar-19 03:16 AM Yeah check for an edvidence of consideration for ground loops 30-Mar-19 03:17 AM well there's a bank of ground lugs on the main frame, and on the power unit 30-Mar-19 03:17 AM But it's entirely possible it's fine to run on a different circuit 30-Mar-19 03:17 AM I've already connected a big ass ground wire from the frame to the power unit lug 30-Mar-19 03:17 AM everything has been really well labelled so far 30-Mar-19 03:17 AM I think the PC desk might have a ground cable too 30-Mar-19 03:17 AM and there's a power strip attached to the desk, which has it's ground lead ripped out from the main cable (i.e. to the wall) 30-Mar-19 03:18 AM I have never worked on a Seiko, so I'm just drawing off experience with FEI/jeol/Hitachi pre merger 30-Mar-19 03:18 AM so I wasn't sure if they intentionally did that or not 30-Mar-19 03:19 AM Yeah see if it goes back to the main ground 30-Mar-19 03:19 AM An independent power source for the computers is not uncommon 30-Mar-19 03:19 AM like, rip the ground from the power strip, and rely only on the lead from the desk to the power unit (the PC has a ground lead from the PC case to the desk) 30-Mar-19 03:19 AM Also before you get the vacuum system spinning test the estop 30-Mar-19 03:19 AM Or epo 30-Mar-19 03:19 AM Or emo 30-Mar-19 03:20 AM hmm, what should I expect it to do? 30-Mar-19 03:20 AM Or whatever Seiko calls it 30-Mar-19 03:20 AM mm 30-Mar-19 03:20 AM I think EMO 30-Mar-19 03:20 AM You should hear the main contactor open up probably 30-Mar-19 03:20 AM I always go through and test that and low air pressure safety's as soon as I can 30-Mar-19 03:20 AM Manual should have a list a safety circuits 30-Mar-19 03:22 AM "Note: When the vacuum interlock in the ion source chamber and in the main chamber are activated simultaneously, the power supply to the ion optical system control power supply are not restored until the vacuum degrees in both the ion source chamber and the main chamber are restored." 30-Mar-19 03:22 AM there are things like that scattered throughout 30-Mar-19 03:23 AM Do you have the service manual? 30-Mar-19 03:23 AM no 30-Mar-19 03:23 AM /does one exist? 30-Mar-19 03:23 AM Hm 30-Mar-19 03:24 AM they wouldn't provide it, as the service reps sold it to me 30-Mar-19 03:24 AM I guess they either think I'm so big shot with $$$$$ or that I'll leak the sekretz 30-Mar-19 03:24 AM Sold the instrument to you? 30-Mar-19 03:24 AM yeah 30-Mar-19 03:24 AM the main sales folks for them 30-Mar-19 03:24 AM Who did you get it from? 30-Mar-19 03:24 AM beam services in pleasanton CA 30-Mar-19 03:25 AM Well it came from the factory with it... 30-Mar-19 03:25 AM they only gave me the 3 PDFs here http://diyhpl.us/~nmz787/pdf/smi3200/ 30-Mar-19 03:25 AM I might have better luck finding one I can share for a Seiko 30-Mar-19 03:25 AM this is the "manual" http://diyhpl.us/~nmz787/pdf/smi3200/HiReSc22.pdf 30-Mar-19 03:25 AM yeah that'd be great 30-Mar-19 03:25 AM I contacted Hitachi, and then got a stern email a few days later from beam services saying "we told you so" 30-Mar-19 03:27 AM ? 30-Mar-19 03:27 AM i.e. that they hold all the cards when it comes to service info 30-Mar-19 03:28 AM Did Hitachi tell beam services or what? 30-Mar-19 03:28 AM "HHS (formerly Epolead service for the Seiko SMI3200) forwarded to me your request for the SMI3200 service manual. The Director of Service asked that I contact you and inform you that they do not provide service manuals and re-iterated to me the agreement between BSI and Epolead to not provide corporate service documentation (see copied quote from him below). " 30-Mar-19 03:28 AM part of the quoted forwarded email "As you know, it is not allowed to provide maintenance documents SMI3200 by the customer.BSI services SMI3200.Please explain it to him." 30-Mar-19 03:28 AM then he signs off with "I am hoping that you have had some success in getting the system operational. If not I can send our Sr. engineer up there to help. Let me know where you are having problems." 30-Mar-19 03:32 AM Wait so Hitachi out sources their service on this system? 30-Mar-19 03:33 AM that's what I seem to understand 30-Mar-19 03:33 AM they were the original sales and service channel 30-Mar-19 03:33 AM this professor told me around the year 2000 is when all the companies stopped providing service docs to customers 30-Mar-19 03:34 AM Hitachi never ceases to amaze me 30-Mar-19 03:34 AM Do you have schematics? 30-Mar-19 03:35 AM nope 30-Mar-19 03:35 AM Wiring diagram? 30-Mar-19 03:35 AM this is a fab-level machine so it makes sense in a capitalistic sense 30-Mar-19 03:35 AM nope 30-Mar-19 03:35 AM Wow 30-Mar-19 03:35 AM Even Thermo isn't that bad 30-Mar-19 03:35 AM At least they weren't in the 2000s 30-Mar-19 03:39 AM more reason I don't want to misstep and break things too soon 30-Mar-19 03:39 AM anyway, gotta sleep now 30-Mar-19 03:39 AM wayyy past my bedtime 30-Mar-19 03:39 AM ttyl 30-Mar-19 10:58 AM moinp 30-Mar-19 10:59 AM moinmoin 30-Mar-19 11:25 AM Moinmoinmoin! 30-Mar-19 01:12 PM I was trying to get a test going last night on the turbo, but unfortunately I wasn't able to get the controller to do anything 30-Mar-19 01:12 PM it kept giving its overload LED which can mean like 1 of 20 things 30-Mar-19 05:55 PM Oh oh oh! It's the thermocouple value not being compatible! 30-Mar-19 05:55 PM The Turbo-V70 has a 50K at 20C termpcouple... I put a 1K resistor in parrelel just to see what would happen... Spun right up :) 30-Mar-19 05:55 PM So the V200 must only require like a 10K or something 30-Mar-19 05:55 PM And now I must wait for spindown Yay... Lol 30-Mar-19 05:55 PM Bearings seem quite happy though. 30-Mar-19 05:58 PM Why wait when you could just not? 30-Mar-19 05:58 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190312_101607-49F1F.jpg 30-Mar-19 06:06 PM that looks like a salad bowl. 30-Mar-19 06:12 PM https://twitter.com/ConnorKrukosky/status/1112160546625855488?s=19 30-Mar-19 06:12 PM I don't know what pressure I got to since I don't have a gauge on the chamber side yet... But I know it was pumping the pressure went up on the roughing side when it started spinning up :) 30-Mar-19 06:58 PM https://twitter.com/ConnorKrukosky/status/1112171891840729089 31-Mar-19 01:11 AM Moin! 31-Mar-19 01:11 AM @Conmega congrats on the TMP! 31-Mar-19 03:06 AM Turbosalad! 31-Mar-19 03:06 AM @Conmega ! 31-Mar-19 03:06 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20190331_121205-80CB1.jpg 31-Mar-19 03:12 AM uhhh 31-Mar-19 03:12 AM nice! 31-Mar-19 03:22 AM I'll definitely try to make the XY section from scratch (milling/turning the whole thing) so the retention sections for the plates are easily machined. 31-Mar-19 07:34 AM LDS are weird with export controls on vacuum gauges. Barotrons and capacitive nanometers are export banned, but ion gauges and inverted magnetrons are just fine to export? 31-Mar-19 07:37 AM why would you ban gauges O.o 31-Mar-19 07:41 AM * manometers 31-Mar-19 07:41 AM They treat every international customer like you’ve got a garage full of Zippe centrifuges. 31-Mar-19 07:45 AM well... 31-Mar-19 07:45 AM a garage alone is not going to help you much 31-Mar-19 02:44 PM I can see that the left-side diagrams here are the main flange pipe, but have no clue what the right-side is https://www.lesker.com/newweb/flanges/flanges_technicalnotes_kf_1.cfm 31-Mar-19 02:44 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Photo_TechnicalNote_Figure6C-C2053.png 31-Mar-19 02:44 PM are they blocking plates? 31-Mar-19 02:44 PM i.e. to cap off a connection? 31-Mar-19 03:09 PM That’s what they look like to me 31-Mar-19 03:09 PM I think a lot of vacuum stuff from the US is export controlled since it can be used in some way with weapons systems. Same with any pulsed power stuff, accelerators, propulsion, etc 31-Mar-19 03:09 PM @nmz787 yes those are KF blank off caps 31-Mar-19 03:12 PM Like this 31-Mar-19 03:12 PM https://www.ldsvacuumshopper.com/nw16blanks.html 31-Mar-19 03:12 PM Yeah but it’s weird that they only prohibit export on cap manos and barotrons and not ion gauges or any other gauge type 31-Mar-19 03:16 PM Yeah I don't know the specifics of why very particular items like that cannot be shipped 31-Mar-19 03:16 PM I have to do loads of export paperwork for all US purchases... benign stuff from Digikey, all LDS Vacuum orders, all University Wafer orders, FLIR stuff... but the weird items they straight up refuse to ship are interesting 31-Mar-19 03:16 PM I wonder if cap manos are specifically good for UF6 use or something 31-Mar-19 03:18 PM Baratron looks like a proprietary capacitance manometer, it looks like other vacuum companies restrict this part too 31-Mar-19 03:18 PM But it does look like other types are banned as well. It seems to have high accuracy, and is referenced often being used in flow controllers due to fast response. 31-Mar-19 03:18 PM Yup, I found it 31-Mar-19 03:18 PM In a reference paper on a case of foreign chinese sellers being arrested for illegally selling them abroad, it states these sensors use metals internally that are resistant to corrosive gases like uranium hexafluoride, and are often used in nuclear centrifuges 31-Mar-19 03:18 PM Makes sense now 31-Mar-19 03:32 PM Yep 01-Apr-19 12:57 AM Cool 01-Apr-19 12:57 AM Still, a lot of applications like DRIE and CVD use corrosive fluorine chemistries with similar material demands to what you would use for UF6, it seems hard to avoid. 01-Apr-19 01:01 AM moin 01-Apr-19 01:31 AM Coin! 01-Apr-19 01:56 AM Moin! 01-Apr-19 01:58 AM night! 01-Apr-19 01:58 AM /sleeps 01-Apr-19 01:58 AM good night 01-Apr-19 01:58 AM most photoresists are quite insensitive to wavelengths >440nm, right? 01-Apr-19 02:13 AM that means yes? 01-Apr-19 02:13 AM ok 01-Apr-19 02:49 AM Yeah, “yellow rooms” are quite brightly lit but just... yellow 01-Apr-19 02:49 AM long as you filter off the blue sharply you can throw quite a bit of light at the resist and it doesn’t care 01-Apr-19 02:49 AM We have a microscope filter that is safe for PR but it looks quite green, it’s not yellow light, so even into the green is a safe wavelength 01-Apr-19 03:22 AM of course it's safe - it's green :3 01-Apr-19 03:22 AM so i guess it's okay to use RGB LED for illumination? 01-Apr-19 03:22 AM WS2812 and alike should be perfect, right? and if their blue is to blue - simply don't use it? 01-Apr-19 06:20 AM RGB LED for exposure? Or for safelight? Or both? You could probably use red for safelight fine and blue for exposure. 01-Apr-19 06:20 AM What photoresist are you using? 01-Apr-19 06:20 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-D6E91.gif 01-Apr-19 06:20 AM Curves for the common AZ positive resists 01-Apr-19 06:20 AM Blue is a bit borderline. 405nm lasers are quite usable for exposure and are quite well matched to the Hg h-line 01-Apr-19 08:47 AM just want to be prepared 01-Apr-19 10:54 AM any Idea what this might be? 01-Apr-19 10:54 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190401_195302-FBEF7.jpg 01-Apr-19 10:54 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190401_195329-9EEAE.jpg 01-Apr-19 10:54 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190401_195312-E49A9.jpg 01-Apr-19 10:54 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190401_195255-837ED.jpg 01-Apr-19 10:54 AM the cup in the middle is connected to the feedthrough, on its sides are magnets 01-Apr-19 10:54 AM built like a penning, but just no inner electrode 01-Apr-19 10:54 AM the feedthrough is a regular BNC, so no >1 kV 01-Apr-19 11:12 AM Looks pretty interesting, difficult to tell. You can definitely push bnc more than 1kv depending on setup though. It could still be a type of penning 01-Apr-19 11:12 AM I've just never seen a BNC in commercial use above 1 kV 01-Apr-19 11:15 AM Got to work on the insides of pheiffer full range gauges today at work. 01-Apr-19 11:15 AM Things with pirani+magnetorn pressure detectors 01-Apr-19 11:15 AM I was suprised that the old "fat" units seem to be 100% analog on the inside. 01-Apr-19 11:15 AM But new one's have a modern ARM mcu 01-Apr-19 11:15 AM And I have pictures! 01-Apr-19 11:16 AM Recently at the lab I was pushing a very tightly spaced SMA feedthrough with probably less that 1mm clearance between ground and central pin to more than 1kv stress testing it at 10^-7 torr with 10ns pulses. 01-Apr-19 11:16 AM Gona dump them in #show-and-tell 01-Apr-19 11:18 AM @GigaSquirrel I don't think your device is pulsed so doesn't really apply as much in your case, but you can stress things quite a bit higher than regular ratings depending how it's driven. That's where all the fun is anyway lol 01-Apr-19 11:19 AM I know you can push BNC way harder 01-Apr-19 11:20 AM @GigaSquirrel That rectangular thing looks like a WR-62 waveguide, possibly WR-75. WR-62 is specified for 12-18GHz or something like that. Tho usable on the upper end of 10GHz and with carefull thinking, on 24GHz. So that thing could be some microwave thing 01-Apr-19 11:20 AM Like power detector with isolator 01-Apr-19 11:20 AM I've just never seen anyone do that on a non prototype device 01-Apr-19 11:20 AM Thus the BNC, but very non-RF "cabling" from the waveguide to BNC 01-Apr-19 11:20 AM if it is a waveguide it would just be stopped 01-Apr-19 11:20 AM like there is no antenna / diode / whatever at the end 01-Apr-19 11:21 AM With a detector diode in the waveguide or something, or there used to be one 01-Apr-19 11:21 AM Ok 01-Apr-19 11:21 AM Just a random thought, because the dimensions look very right for waveguide and magnetic stuff in the middle like that could imply an isolator/circulator, something weirder. 01-Apr-19 11:21 AM It could also be the reverse and be a Gunn-diode mount and the BNC power+modulation 01-Apr-19 11:24 AM direct DC path from the cup to the BNC 01-Apr-19 11:24 AM I don't think that is an rf waveguide piece, bnc would be horrible at that high frequency range 01-Apr-19 11:25 AM +1 01-Apr-19 11:25 AM @Applied_Ion Yep, that's why I was thinking DC bias to a Gunn- or detector diode 01-Apr-19 01:10 PM well 01-Apr-19 01:10 PM today was a day 01-Apr-19 01:10 PM I got a new chamber 01-Apr-19 01:10 PM with lots of weird flanges 01-Apr-19 01:10 PM gold sealed 01-Apr-19 01:10 PM almost 4 g of gold wire 01-Apr-19 01:10 PM which is almost enough to buy a single adapter to actually use one of the holes 01-Apr-19 01:10 PM I'm gonna try replacing that with solder 01-Apr-19 01:13 PM Was the chamber from your synchrotron stuff? I saw the chamber, looks pretty sweet, though those odd flanges could be a pain to deal with 01-Apr-19 01:14 PM nope, I got that from @Koelzer 01-Apr-19 01:14 PM who got it from university scraps iirc? 01-Apr-19 01:15 PM Gold wire seals make sense for UHV stuff needing large flange sizes, especially for rf based systems. What's iirc again? 01-Apr-19 01:15 PM if i remember correctly 01-Apr-19 01:15 PM everything is gold sealed, but there was one iso seal with some o-ring 01-Apr-19 01:15 PM so I guess the whole thing was not designed for UHV 01-Apr-19 01:16 PM !!! Why haven't I thought about university surplus (tbh my rubidium frequency source among other crap is from that source) about vacuum stuff. 01-Apr-19 01:16 PM you're welcome 01-Apr-19 01:17 PM I know a dude who at least used to work on accelerators 01-Apr-19 01:17 PM @rfs yeah if you can find connections at a university to get vacuum stuff, do it lol. That is literally one of the best ways to get the highest tech equipment for nothing, and universities are amazingly wasteful 01-Apr-19 01:18 PM They are! 01-Apr-19 01:18 PM And yeah I do have some friends who work at a local university. 01-Apr-19 01:18 PM Just not on vacuum, nuclear or accelerator stuff. 01-Apr-19 01:18 PM That accelerator dude is just an aquintance. I have only scrapped some HUGE power supplies in that accelerator lab 01-Apr-19 01:18 PM like +30kg ~3phase low voltage DC beasts. 01-Apr-19 01:19 PM uhm 01-Apr-19 01:19 PM 3 phase DC? 01-Apr-19 01:20 PM 3phase mains input 01-Apr-19 01:20 PM My most important vacuum component for my system I have yet to reveal was gained through these means, as well as other critical part through a friend who knows people tossing stuff. 01-Apr-19 01:20 PM I should have some of the output copper busbars somewhere 01-Apr-19 01:20 PM it had like +20 TO-3 transistors in the current regulator 01-Apr-19 01:20 PM Yeah I'll have to mention my relatively new interest in vacuum stuff to those folks the next time we meet. 01-Apr-19 01:22 PM Accelerators are scrapped more than they are built now at universities, but it's mainly luck to be in the right place at the right time. If you know someone, definitely use it to your advantage, you can get some crazy awesome stuff really only through this way. 01-Apr-19 01:22 PM The electrical engineers guild there has a hobby SEM, I think, but IIRC no motivated folks with knowledge to bring it up. And due to renovations it's in storage. 01-Apr-19 01:22 PM Yeah I know that there's awesome stuff floating around, I'm just an appartment dweller, I cant hoard the parts from an accelerator. I'd have to call friends and share :/ 01-Apr-19 01:22 PM invite them to the server 01-Apr-19 01:26 PM Though I have contacted dozens of labs in the US asking for scraps and trash way back when I was started over a year ago, no luck getting anything. Tbh, being younger helps an almost absurd amount, labs are much more inclined to give stuff to a high schooler than a working adult lol (I am the latter) 01-Apr-19 01:26 PM And I see no issue with hoarding accelerator parts... 01-Apr-19 01:27 PM well just tell them you're young 01-Apr-19 01:27 PM Lol I refuse 01-Apr-19 01:27 PM I've signed mails asking for stuff with "Regards, Dr. [Name]" 01-Apr-19 01:27 PM that's how you get stuff 01-Apr-19 01:29 PM I can't do that, I don't like misrepresentation and lack of transparency in engineering (a bit ironic since my big system is under wraps still, but I will release the full details and show how it's built hopefully soon!) 01-Apr-19 01:30 PM Yeah being young helps a lot. Everybody loves motivated and interested beginners. And wants to provide them with tools and advice they did not have. 01-Apr-19 01:30 PM @Applied_Ion The issue with hoarding accelerator parts is not the hoarding part, but the lack of space to do the hoarding. 01-Apr-19 01:33 PM I have a baby... I can definitely tell places the stuff is for his (future) school science projects 01-Apr-19 01:33 PM "my son is looking for XXYY" 01-Apr-19 01:35 PM My 3 month old kid wants to build a fusor, please sponsor! 01-Apr-19 01:35 PM fusor forum be like 01-Apr-19 01:35 PM Yeah, I have noticed a quite significant age bias when it comes to science and donations for hobby stuff. I have seen high schoolers get many thousands of dollars in money and parts for vacuum stuff, and do little more than rudimentary basics with them that can be done for an order of magnitude cheaper usually. But that's also the reason I like the radical underdog approach. No help, built from scraps from the ground up, scraping by on the knife edge between success and failure, it's the brutal struggle that makes the victory sweeter 01-Apr-19 01:35 PM Oh god, don't get me started on the fusor stuff again lol... 01-Apr-19 01:35 PM @rfs yeah, space is definitely the big issue 01-Apr-19 01:35 PM Especially since vacuum stuff is often heavy af 01-Apr-19 01:35 PM I swear by the time I'm done with these builds I should be ripped lol. I'm pretty sure accelerator and vacuum people are all secretly ripped having to lug massive pumps, chambers, torque down bolts, etc 01-Apr-19 01:37 PM lol 01-Apr-19 01:37 PM Lol fusors. I did not even consider them before joining this discord. Now I'm interested in building one. 01-Apr-19 01:37 PM I guess the real interest in that is "ooh shiny", "lol table top fusion in my kitchen" and "Building the measurement electronics for detecting the neutrons, possible activation and other related stuff is fun" 01-Apr-19 01:37 PM My main interest in vacuum was building a sputtering rig for the metallization of 3d printed waveguide parts and fixtures. 01-Apr-19 01:39 PM Don't get me wrong. There is absolutely nothing wrong with them, despite how often I kind of rip on the fusor group. I just think a lot of times people pursue it for the wrong reasons. And that no one tries anything new with them, all the same usual stuff that has been done ad nauseum. 01-Apr-19 01:40 PM Should be better than MG Chemicals spray on EMC stuff 01-Apr-19 01:40 PM @rfs I have actually considered sputtering 3d printed parts as well! 01-Apr-19 01:40 PM Certainly be useful for waveguide stuff 01-Apr-19 01:41 PM everyone should have a fusor and HPGe to do activation analysis stuff 01-Apr-19 01:42 PM so called airgas about Nitrogen, they sell full 80CF tanks for $250 and full 150CF tanks for $270... with refills (swap actually) being $43 and $50 respectively 01-Apr-19 01:42 PM a friend was telling me last night that liquid hitting the gas valve/regulator can be catastrophic 01-Apr-19 01:42 PM so obviously I'm a bit wary of getting into gas cylinders 01-Apr-19 01:42 PM (i.e. if it got knocked over) 01-Apr-19 01:47 PM @Applied_Ion you don't have to lie to people to make them think your young 01-Apr-19 01:47 PM I would just tell them I'm a student, I am on and off finishing a degree, I do go to college, so I am a student 01-Apr-19 01:47 PM :) 01-Apr-19 01:47 PM most people assume students are young and don't have a job 01-Apr-19 01:48 PM @GigaSquirrel the only activation stuff you will see me attempting will be through proton reactions lol, no fusion neutrons for me 01-Apr-19 01:48 PM doesn't mean you don't 01-Apr-19 01:48 PM @Conmega I'm not a student anymore... 01-Apr-19 01:48 PM Just go take a course once a year and legally your a student every year :P 01-Apr-19 01:48 PM If your that concerned about it anyway 01-Apr-19 01:48 PM @Applied_Ion well you're going to have stray neutrons, no mater what 01-Apr-19 01:49 PM but I dunno, in my opinion, yes they may be more willing to give stuff to students sometimes, but sometimes I've seen people more willing to give stuff to competent people, no-matter what your age/etc is 01-Apr-19 01:49 PM @GigaSquirrel yes but they won't be fusion products 01-Apr-19 01:49 PM because they would rather give it to someone who will put it to good use and not destroy the object 01-Apr-19 01:49 PM yep 01-Apr-19 01:50 PM so your either a student and get extra stuff from bob, or your a competent adult doing amazing things and getting something from jeff 01-Apr-19 01:50 PM I'm just saying everyone should have a fusor bc I thing some might shy away from a spallation source 01-Apr-19 01:51 PM I'd love to build a little fusor in some 2.75" conflat just because I don't think I have a use for a massive one? But I also have no idea what I'd do with a fusor other than say oohhh ahhh... XD 01-Apr-19 01:51 PM I need to learn of some of the cool uses for it 01-Apr-19 01:51 PM I saw that video someone posted of using neutrons for that gold implantation 01-Apr-19 01:51 PM anyone here boil LN2 for N2 gas supply? 01-Apr-19 01:51 PM but I don't think turning gold to mercury is... the best use lol 01-Apr-19 01:51 PM do some physics with it @Conmega 01-Apr-19 01:52 PM @Conmega yeah that's true, also why I've put so much effort into documenting my stuff and building up a website as more of a professional approach than purely hobby per say, with the hope maybe one day I'll have enough decent resources maybe I could start crowd funding research 01-Apr-19 01:52 PM build detectors and use the fusor as check source 01-Apr-19 01:52 PM @nmz787 LOL I dunno if that's the most efficient or cheapest way to get N2... but you could? 01-Apr-19 01:52 PM 2.75" fusor would be fine to work with 01-Apr-19 01:52 PM I mean go to a welding supply shop and get N2 01-Apr-19 01:52 PM @Conmega adam said most labs do it that way 01-Apr-19 01:52 PM @Conmega and the FIB lab I part-time at used to do it that way too 01-Apr-19 01:52 PM before switching to compressed air 01-Apr-19 01:54 PM @Conmega I'd actually prefer to do 2.75" and see how far I could push it with a pulsed approach 01-Apr-19 01:54 PM There might also be food grade N2 as it's also used as a protective gas in packaging. 01-Apr-19 01:54 PM A friend uses food grade CO2 for welding due to it being cheaper to him. 01-Apr-19 01:55 PM @GigaSquirrel yeah, and spallation wouldn't be a beginner learning project anymore. Not to mention it's really starting to take up way more room than I initially planned lol 01-Apr-19 01:56 PM the welding company said they only have "industrial" as the standard grade... anything else would be special order (I didn't ask about pricing on that) 01-Apr-19 01:57 PM @nmz787 any reason you need boiled N2 vs just compressed nitrogen? What's the purity you need? 01-Apr-19 01:58 PM nah, just @AdamMcCombs mentioned many labs prefer getting LN2, I guess being in a low-pressure cylinder vs high-pressure maybe safer? 01-Apr-19 01:58 PM @Applied_Ion just dry, no moisture for rust to form 01-Apr-19 01:58 PM @AdamMcCombs said desiccant filters for compressed air won't dry things enough for chamber venting 01-Apr-19 01:59 PM If you have a proper regulator the gas cylinders are not a problem. Also, we have just used nitrogen from tanks when venting our high vacuum stuff, just regular grade, nothing special 01-Apr-19 01:59 PM What level of vacuum are you going for? Not really worth crazy effort if you are below UHV levels 01-Apr-19 02:01 PM my FIB has a big turbo and an IGP 01-Apr-19 02:01 PM also more than likely has column isolation valves 01-Apr-19 02:01 PM and a load-lock, so the main chamber doesn't even need to vent 01-Apr-19 02:01 PM (the load lock has it's own smaller turbo) 01-Apr-19 02:01 PM otherwise there's valving that needs 100PSI gas 01-Apr-19 02:02 PM @Applied_Ion You're going for spallation? I thought you were aiming to crack the 1 MeV "barrier"? 01-Apr-19 02:02 PM (well the input to the whole machine takes 100PSI) 01-Apr-19 02:02 PM iirc there's still some way from there to spallation 01-Apr-19 02:03 PM I know the FIB I part-time work on sometimes, gets to 10-6 or 10-7 at best, with 30-60 mins of pumping 01-Apr-19 02:03 PM I haven't fired mine up yet 01-Apr-19 02:03 PM I feel like the column/source might get to 10-8 01-Apr-19 02:04 PM @GigaSquirrel spallation is not the goal. First goal is break the 1 MeV barrier. I can theoritically hit a max of 6MeV with my current system if everything works perfectly, so the primary sources of activation will be proton capture at that level. 01-Apr-19 02:05 PM 6 MeV if everything goes to plan or the kind of "if friction was not real" theory? 01-Apr-19 02:05 PM looks like the spec sheet says the source would be at 10^-5 pascals, which is 10^-7 mbar 01-Apr-19 02:06 PM "Assume spherical cow" 01-Apr-19 02:06 PM http://i.imgur.com/nO5cW4c.jpg 01-Apr-19 02:06 PM Just a classic thing from the high school physics text books around here. 01-Apr-19 02:09 PM @GigaSquirrel No, if everything goes to plan (I.E. primary beam succesfully hits 300kv, min 1kA beams). Based on the primary driver specs and a thorough literature review of historic systems built in the past it should be attainable with my setup. Remember, the ultimate goal is reviving a dead accelerator technology and bringing it to light again. The beauty is, the mechanism has show to be scalable down to the 10s of kev range. I'm just going overboard with mine, but I could very easily drive it at radically reduced power to generate many hundreds of kev beams easier. 01-Apr-19 02:10 PM really looking forward to see the kind of accelerator you're using 01-Apr-19 02:10 PM like having an injector accelerator and somehow boosting that, dependant on the injector beam current 01-Apr-19 02:10 PM that sounds like some slac level stuff 01-Apr-19 02:17 PM Having seen spark gap teslacoils I have some slight doubts about the spark gap switches. But at the voltages and currents mentioned, it is the path I would also attempt. Just wondering how much copper will vaporize and coat the insides of the spark gaps, if they don't blow appart. 01-Apr-19 02:31 PM @rfs wow, don't get me started on spark gap switching, this is one of my specialties. Spark gaps can be incredibly high performance 01-Apr-19 02:31 PM Like state of the art spark gaps are unreal 01-Apr-19 02:31 PM trig'd 01-Apr-19 02:32 PM Ok, good to hear. I figured you had thought it out properly and consulted tons of literature. 01-Apr-19 02:32 PM You haven't lived pulsed power until you have gone into high performance gaps 01-Apr-19 02:32 PM no actually do get started on that 01-Apr-19 02:32 PM it's always great to learn something 01-Apr-19 02:32 PM My system actuslly will use it think 12 gaps now? 01-Apr-19 02:33 PM I'm just a loud mouth idiot with high school physics and some collage under my belt. And weird friends and acquittances. 01-Apr-19 02:33 PM 9 small pressurized air gaps, 1 large pressurized air gap, and 2 water switches 01-Apr-19 02:33 PM Water switches? 01-Apr-19 02:33 PM some of them laser triggered? 01-Apr-19 02:33 PM Tesla coil gaps are weak cheap crap of the gap world. 01-Apr-19 02:33 PM Oh yes. That's why my friend built it! 01-Apr-19 02:34 PM you said it's not an induction linac, right? 01-Apr-19 02:34 PM Was easier and cheaper than proper IGBT bridge. 01-Apr-19 02:34 PM Oh yeah. Spark gaps can be high pressure air, gas, water gaps, oil gaps, solid spark gsps, the technology is crazy 01-Apr-19 02:36 PM MY main thinking about spark gaps has been the generation of microwaves and millimeter waves. As JC Bose used spark gap transmitters for his 60GHz and 100GHz experiments around 1898. Dude discovered circular polarisation and invented the split prism attenuator. 01-Apr-19 02:36 PM @GigaSquirrel no laser triggering. Not done for water gaps, those are almost always overvoltage self breaking gaps. Also, current doesn't really determine boosted energy of the accelerator. It's a two stage device, but radically unconventional, a passive type acceleration mechanism 01-Apr-19 02:37 PM And I have heard that some USA ham has made a legal spark gap transmitter for the 5.6GHz band. 01-Apr-19 02:37 PM damn it, every time I get an Idea you tell my what it's wrong 01-Apr-19 02:41 PM Also not an induction linac, though I believe one could be done wth cheap metglass cores from china. It would be more costly and complex, but theoretically possible 01-Apr-19 02:41 PM But you are on an interesting track... 01-Apr-19 02:43 PM found pieces of a paper describing a light ion accelerator that somewhat matched your specs 01-Apr-19 02:43 PM scaled accordingly ofc 01-Apr-19 02:43 PM but the main accelerator was induction based 01-Apr-19 02:43 PM https://digital.library.unt.edu/ark:/67531/metadc625526/m1/1/ 01-Apr-19 03:26 PM @GigaSquirrel good guess, but not the type I am building. Hermes and the accelerators in that power class are absolute beasts lol, really awesome stuff. The highest peak power systems use some of the craziest pulsed power techniques. Like looking at the power flow for the Z machine is thrilling (at least for me lol) 01-Apr-19 03:27 PM Everyone's got their thing they get of to 01-Apr-19 03:27 PM Very excellent guess though 01-Apr-19 03:28 PM ^^ 01-Apr-19 03:28 PM well, I've got to go to work tomorrow 01-Apr-19 03:28 PM => Good night everyone 01-Apr-19 03:33 PM Night! 01-Apr-19 03:34 PM Night! 01-Apr-19 03:35 PM I feel like the more I chat in here about what to do with my small turbo/chamber after I use it for pumping down my EDS head the more I am led towards building a small fusor lol 01-Apr-19 03:35 PM would be fun to experiment with different designs of the anode/cathode wire frames and such... 01-Apr-19 03:35 PM I always see very very similar designs, like shown from the original built fusors I guess. I dunno if thats just the most "efficient" that we've found or just because they are simple to construct. 01-Apr-19 04:46 PM Personally I'm an beam on target fan, I think there is more work you can do with that to make some really high flux sources 01-Apr-19 04:51 PM Oh that looks pretty cool and useful 01-Apr-19 04:51 PM going through a thread on the fusor forums on a beam on target build, I just learned there is machinable ceramic... that's awesome to know :) 01-Apr-19 05:42 PM Oh yeah macor 01-Apr-19 05:42 PM That stuff is expensive 01-Apr-19 05:42 PM But super awesome 01-Apr-19 06:06 PM @AdamMcCombs +1 for beam stuff, in my opinion it's infinitely more versatile. If you want real neutron fluxes though, u gotta go pulsed. There is a reason why commercial generators are pulsed. 01-Apr-19 06:08 PM Oh yeah, and just getting into BoT gets you into a lot of other ion optics stuff 01-Apr-19 06:10 PM @Conmega grid geometry doesn't really play as much role. Loading and drive parameters do more. Current, voltage, pressire, external beams, etc 01-Apr-19 06:10 PM Cough pulsed cough 01-Apr-19 06:10 PM Also lots of other stuff most people don't try, like multiple grid topologies (more than the single one, I've seen like 3 or 4 grid fusors, etc) 01-Apr-19 06:10 PM Also boron nitride is another machinable ceramic that is thermally conductive 01-Apr-19 06:21 PM yea the first thing that came to my mind was multiple grids... 01-Apr-19 06:21 PM awesome I may have to play with fusor stuff, need tons more parts though 01-Apr-19 06:21 PM also hrm, I think I found my leak, I tightened a bunch of stuff, the 4.5" conflat which I re-used a seal for... and all the 2.75" I tightened to 10ftlbs 01-Apr-19 06:21 PM and pumping down with the roughing I noticed I only got to like 4~E-2 01-Apr-19 06:21 PM put some iso near the 4.5 and instantly went down to like 2... 01-Apr-19 06:24 PM Reusing conflat gaskets is not a good idea, it won't seal the same as the first time 01-Apr-19 06:24 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-78C80.png 01-Apr-19 06:24 PM I know... I need to make an order to LDS but have been putting it off 01-Apr-19 06:24 PM I had one 4.5" that was used I pulled out of something and tried... figured it was worth a shot 01-Apr-19 06:24 PM oh well 01-Apr-19 06:24 PM lol 01-Apr-19 06:24 PM man that iso plugs up the leak for a long time doesn't it... 01-Apr-19 06:55 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-7883C.png 01-Apr-19 06:55 PM the center dip was the turbo on, the small dip after that is adjusting the gas load on the roughing pump, the curve off is shutting off the valve for the roughing pump and turning off the roughing pump 01-Apr-19 07:06 PM Is that for the tiny turbo? What chamber is it hooked up to? 01-Apr-19 07:44 PM the one I posted to twitter the other night 01-Apr-19 07:44 PM I realized I had a different adapter though and am going to try and simplify this down a bunch 01-Apr-19 07:45 PM I remember seeing that, I'll have to go back and look closer, too many projects flying around to keep track of everything lol 01-Apr-19 07:46 PM :) 01-Apr-19 07:46 PM yea I bet its my 4.5" that is the main problem but I am trying to get rid of the other parts that I might suspect too 01-Apr-19 07:46 PM I need more KF16/10 adapters blugh 01-Apr-19 07:48 PM Uh, is that hose clamp on the kf flange maybe an issue too? 01-Apr-19 07:48 PM hm? 01-Apr-19 07:48 PM where? 01-Apr-19 07:48 PM leme get a photo 01-Apr-19 07:49 PM With a chamber that small hooked up to the turbo, you should be able to pull pretty high vacuum quite fast 01-Apr-19 07:49 PM It's across from the gauge 01-Apr-19 07:49 PM After the elbow 01-Apr-19 07:49 PM The black plastic one? I am trying to replace that one atm 01-Apr-19 07:50 PM No, it's after that, unless I am seeing it wrong 01-Apr-19 07:50 PM On that 4 way kf adapter after the plastic piece where the gauge is attached, looks like a hose clamp is clamping down on the kf blank directly across from the gauge 01-Apr-19 07:50 PM Also maybe on the gauge as well? 01-Apr-19 07:52 PM These are weird KF clamps... 01-Apr-19 07:52 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1833-2F21E.jpg 01-Apr-19 07:54 PM That doesn't look standard, looks like it was broken and the previous owner tried to clamp it with hose clamps lol 01-Apr-19 07:54 PM I'm not sure how well it clamps compared to normal, maybe it will work but that's one thing that stood out immediately 01-Apr-19 07:54 PM I'd say that and your reused conflat gasket may be the two big potential contributors for leaks 01-Apr-19 07:54 PM When I was troubleshooting my roughing line, I systematically went to every joint and cranked down while watching the gauge. It's usually just one or two joints that may be slightly less clamped enough that you don't get a fully solid seal 01-Apr-19 08:01 PM these are totally designed to clamp like this... 01-Apr-19 08:01 PM they came off a machine and there were tons of these on there 01-Apr-19 08:01 PM these are never meant to be removed so it makes sense 01-Apr-19 08:01 PM but yea they clearly aren't broken off clamps... 01-Apr-19 08:03 PM That's pretty weird lol. If you still decide to use them, I'd crank down extra hard on the hose clamp to be sure 01-Apr-19 08:03 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1834-5A8AB.jpg 01-Apr-19 08:03 PM Will do lol 01-Apr-19 08:04 PM Idk, those look modified still to me. Like they were cut/ground from a normal one 01-Apr-19 08:04 PM I'm not sure hose clamps will give as good of a clamping force compared with the normal mechanism, it may have to be clamped really, really hard to work similar 01-Apr-19 08:09 PM I mean they have grooves on the outer surface to keep the clamp centered... 01-Apr-19 08:09 PM I have not seen any other clamp with that outer grooving... 01-Apr-19 08:10 PM Yeah idk lol, this is a first for me 01-Apr-19 08:20 PM ok roughing seems a bit better now... 01-Apr-19 08:20 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-E4439.png 01-Apr-19 08:20 PM but yea definitely still not happy 01-Apr-19 08:20 PM I'll have to order 4.5" copper 01-Apr-19 08:20 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-C7468.png 01-Apr-19 08:20 PM and some more KF stuff 01-Apr-19 08:20 PM shut off the turbo, still pumping lower lol 01-Apr-19 11:23 PM moin! 01-Apr-19 11:33 PM Yeah that turbo cure is characteristic of a leak 01-Apr-19 11:33 PM Or heavy contamination, but more likely a leak 02-Apr-19 12:28 AM hiiii 02-Apr-19 12:28 AM miin 02-Apr-19 12:28 AM moin 02-Apr-19 12:32 AM I'm heading to Seattle tomorrow afternoon, aiming to meet a friend who's at a medical conference thing there but not sure what time he's available, I'm aiming to arrive around 5PM... in case anyone wants to tour me around a lab, etc 02-Apr-19 12:32 AM I might end up leaving tomorrow night, or sometime the next day 02-Apr-19 01:07 AM @nmz787 Check this out https://www.meetup.com/Seattle-Hardware-Happy-Hour-3H/ 02-Apr-19 01:07 AM Im not sure if im going but you will be in town at the perfect time for it 02-Apr-19 01:08 AM alas I will be back in Portland-area at the latest, sometime on the 3rd 02-Apr-19 01:18 AM I'm 1 day off aren't i 02-Apr-19 01:19 AM stupid midnight date shift 02-Apr-19 01:19 AM Yeah 02-Apr-19 01:19 AM It's not great 02-Apr-19 05:59 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190402_132419-987AA.jpg 02-Apr-19 05:59 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190402_132411-A7F0A.jpg 02-Apr-19 05:59 AM I think someone wants me to go in there 02-Apr-19 07:38 AM And i finally held some Pu 239 02-Apr-19 07:38 AM next point off my list :D 02-Apr-19 10:38 AM Tomorrow I'll get an LiI:Eu scintillator, has anyone here ever worked with those? 02-Apr-19 10:38 AM it's a bit too small for gamma spectroscopy, so my only task is to reject all non neutron events 02-Apr-19 10:38 AM my first thought is pulse height disc, but I don't know if that is enough 02-Apr-19 12:06 PM Oh dear lord 02-Apr-19 12:06 PM https://www.ebay.com/itm/Giant-Beryllium-metal-window-14-40cm-clear-aperture-with-high-vacuum-conflat/123718542260 02-Apr-19 12:07 PM Wow, that's insane 02-Apr-19 12:08 PM oh wow 02-Apr-19 01:24 PM that's incredible 02-Apr-19 01:26 PM yea... stick that in front of a decent xray source and have bunches of fun :) 02-Apr-19 01:26 PM Horrible idea... what happens if you filled the cut in a used conflat with solder and tried to reuse it from there? lol 02-Apr-19 01:26 PM I think solder cracks more than it deforms so probably just super bad leaking 02-Apr-19 01:26 PM just a stupid idea lol 02-Apr-19 01:43 PM I mean 02-Apr-19 01:43 PM it might work? 02-Apr-19 01:44 PM would be fun to try I guess 02-Apr-19 01:44 PM shouldn't hurt anything theoretically 02-Apr-19 01:44 PM so long as I clean all the flux off real well 02-Apr-19 01:45 PM dunno how critical the thickness is 02-Apr-19 01:45 PM haven't worked with CF yet 02-Apr-19 01:45 PM yea I dunno 02-Apr-19 01:46 PM worst case you'd have to mill / turn it down 02-Apr-19 01:46 PM its something I can do if only to make @AdamMcCombs cringe :) 02-Apr-19 01:46 PM nahhh sand it flat on some glass 02-Apr-19 01:47 PM exact same result, just more physical work 02-Apr-19 01:49 PM sure, don't have a mill or lathe yet though so.... :) 02-Apr-19 01:49 PM but I'm good at soldering, I should be-able to get it pretty smooth 02-Apr-19 01:49 PM perfect excuse to get one 02-Apr-19 01:50 PM just need to use the heat gun to get the gasket pretty evenly heated 02-Apr-19 01:50 PM otherwise its going to be a nightmare trying to get it to solder 02-Apr-19 01:51 PM Yep 02-Apr-19 01:51 PM maybe preheat it in the oven 02-Apr-19 01:51 PM maybe lol 02-Apr-19 01:51 PM gotta make another 100+ LDS order yay 02-Apr-19 01:51 PM running out of roughing pump oil and need these 4.5" conflat gaskets 02-Apr-19 01:57 PM just get a 20 liter barrel of S2R100 02-Apr-19 01:57 PM @Pan Da and I did that, was like 100 bucks and we'll never have to buy new 02-Apr-19 01:58 PM lol what 02-Apr-19 01:58 PM didn't realize shell made vacuum pump oils 02-Apr-19 01:58 PM looks unavailable everywhere 02-Apr-19 01:58 PM either they don't make it anymore or 02-Apr-19 02:00 PM maybe it's more common in the european market? 02-Apr-19 02:00 PM I can get 1 liter for 17€, 20 liter for 116€ and 209 liter for 990€ 02-Apr-19 02:01 PM LDS's vacuum pump oil for 38 bucks a gallon isn't bad 02-Apr-19 02:01 PM they do sell it in 55 gallon barrels for like a stupid amount 02-Apr-19 02:01 PM but I mean 02-Apr-19 02:01 PM I used a lot because of trying all the roughing pumps I had 02-Apr-19 02:01 PM and unfortunately realizing one needed a partial rebuild 02-Apr-19 02:01 PM I probably would have only been half way through my gallon jug if I had not found out I had two pumps that need work 02-Apr-19 02:01 PM after this gallon I get I will probably be fine for months and months 02-Apr-19 02:03 PM unless you buy more and more pumps 02-Apr-19 02:03 PM or sell the rest 02-Apr-19 02:04 PM also another chunk of the order is buying an NW25-NW16 adapter I want to get... I could totally save like 10-20 bucks buying from ePay/china but I am impatient and don't want to spend the time finding all the cheapest little bits 02-Apr-19 02:04 PM I mean I have 4 roughing pumps now, the Hitachi for the SEM which is in good shape just the two orings and 4 shaft seals were dried out... 02-Apr-19 02:04 PM so I ordered those parts and will put it back together and run it for a good long while 02-Apr-19 02:04 PM the Alcatel 2008A which I got just the other day which is totally a fresh rebuild and runs GREAT 02-Apr-19 02:04 PM the Alcatel 2008AC which is rated for corrosive gases... doesn't run great, is pretty loud, but will be worth rebuilding if I ever need corrosive gas use 02-Apr-19 02:04 PM And the RV12 which runs okish... but is probably going to need a rebuild someday in the future 02-Apr-19 02:04 PM the Hitachi will be in service on the SEM when I get those parts, the Alcatel 2008A is my main experimenting pump at the moment on the bench, the RV12 will be a secondary to that if I ever need it or don't want to be switching between pumps on two different rigs. 02-Apr-19 02:04 PM I just need more conflat dangit 02-Apr-19 02:08 PM don't we all 02-Apr-19 02:08 PM and a name to my weirdaß flange thingy 02-Apr-19 02:09 PM LOL creative use of the ß 02-Apr-19 02:12 PM I took the tiniest bit of german back in high school and remember thats that like double s sound thing 02-Apr-19 02:12 PM I really need to get a foreline trap but I don't want to spend the 125 bucks for a used filter 02-Apr-19 02:12 PM its like just a cylinder with a wire cage with some of that crushed stone 02-Apr-19 02:12 PM its like gahh why 02-Apr-19 02:13 PM I've got one I don't really need 02-Apr-19 02:14 PM I am tempted to just use the KF40 stuff I have to make one lol 02-Apr-19 02:14 PM what does the one you have look like? 02-Apr-19 02:15 PM https://www.n-c.com/ECommerceSite/media/Images/MenuLevelPhotos/01TRAP09_md.jpg 02-Apr-19 02:15 PM bit bigger body and two KF16 flanges 02-Apr-19 02:15 PM ah interesting 02-Apr-19 02:15 PM my roughing lines are KF25 though on all my pumps 02-Apr-19 02:15 PM https://www.ebay.com/itm/Edwards-High-Vacuum-Foreline-Inlet-Trap-For-Rotary-Vane-Pump-KF-25-NW25/192346311769 02-Apr-19 02:15 PM oh this just got discounted 02-Apr-19 02:15 PM 75 bucks is a bit more.... reasonable 02-Apr-19 02:15 PM wish there were more photos 02-Apr-19 02:16 PM if there are no phots the seller is trying to hide something 02-Apr-19 02:16 PM imo 02-Apr-19 02:16 PM I mean possibly but its also listed as remanufactured 02-Apr-19 02:16 PM so if its not freshly refilled/clean/ready to go I can get my money back EASY 02-Apr-19 02:16 PM yea screw it I'll go for it now that I noticed that 02-Apr-19 02:16 PM if it looks not refurbished I can just do an ePay claim 02-Apr-19 02:18 PM good luck 02-Apr-19 02:19 PM this is why you must be honest and write things up well on eBay 02-Apr-19 02:19 PM if you cut corners you will be burned 02-Apr-19 02:19 PM hehehehe 02-Apr-19 02:19 PM hehe 02-Apr-19 02:19 PM he 02-Apr-19 02:19 PM yep 02-Apr-19 02:19 PM I don't ever abuse eBay's buyer protection, but if your going to lie, post things incorrectly, etc 02-Apr-19 02:19 PM then nope your gona get it 02-Apr-19 02:19 PM or just in general not provide the amount of photos for something you expect to get a reasonable amount of money for 02-Apr-19 02:20 PM is currently suing someone over lying on ebay and sending insults and threads over a bad review 02-Apr-19 02:20 PM like if it was 20 bucks then sure I wouldn't argue if it was half missing pieces really 02-Apr-19 02:20 PM LOL WTF 02-Apr-19 02:20 PM seriously?? 02-Apr-19 02:21 PM bought a manual for 15€, but that only was a cheap copy 02-Apr-19 02:21 PM like some parts not readable cheap 02-Apr-19 02:21 PM ahh wow wth 02-Apr-19 02:22 PM after a month of asking for a refund i was like "f this, I can live with 15€less" and gave him a negative review 02-Apr-19 02:22 PM after which he suddenly started answering to my mails 02-Apr-19 02:22 PM and wrote the most stupid insults 02-Apr-19 02:22 PM and stuff like "watch out what you do or I will come over and beat you up, I've still got your adress" 02-Apr-19 02:22 PM maybe sue is not the right word? 02-Apr-19 02:22 PM sue / bring him to court 02-Apr-19 02:22 PM whatever 02-Apr-19 02:25 PM Now that I made the order to LDS I'll realize I need this that and the other thing by tomorrow :) 02-Apr-19 02:25 PM oh jeez yea threatening like that over a freaking review wow 02-Apr-19 02:25 PM Best mail from him was "Bet you're really stupid and went to a school for mentally retarded people, because you misspelled your name, "gigabequerel" would be correct" 02-Apr-19 02:26 PM lol wtf 02-Apr-19 02:26 PM haha, and his newest offers on ebay warn people in the description not to interact with me, without any context xD 02-Apr-19 02:26 PM just wow yea print all that out and just like court you me now buddy 02-Apr-19 02:26 PM LOL WHAT seriously?! 02-Apr-19 02:26 PM HAHAHA 02-Apr-19 02:26 PM WHATTT 02-Apr-19 02:26 PM jesus some people man 02-Apr-19 02:27 PM yep 02-Apr-19 02:27 PM BUT 02-Apr-19 02:27 PM when I was with the police they just typed his name into the database and got a dirty grin 02-Apr-19 02:27 PM Oh god 02-Apr-19 02:27 PM so he's already known there 02-Apr-19 02:27 PM lmao 02-Apr-19 02:28 PM I'm somewhat hoping I ruined a probation for him 02-Apr-19 02:28 PM but yeah 02-Apr-19 02:28 PM from that point on I changed my buying behaviour 02-Apr-19 02:28 PM paypal only, so it's easy for me to get my money back 02-Apr-19 02:28 PM and only buy things where it's obvious what I'll get 02-Apr-19 02:36 PM Lol fair enough 02-Apr-19 02:41 PM aww yeah 02-Apr-19 02:41 PM just ordered the final parts for my oven 02-Apr-19 02:41 PM 1400°C here we come 02-Apr-19 02:41 PM oh wow, you can't buy borax as an individual anymore 02-Apr-19 02:48 PM LOL wat 02-Apr-19 02:48 PM also sweet! 02-Apr-19 02:48 PM I need a freaking tube furnace 02-Apr-19 02:48 PM forgot... need to add that to my radar again 02-Apr-19 02:48 PM what for, semiconductor stuff? 02-Apr-19 02:49 PM yea 02-Apr-19 02:49 PM I need a quartz tube furnace so I can grow silicon oxide layers in certain atmospheres for a clean growth 02-Apr-19 02:49 PM https://twitter.com/thomasfuchs/status/1112589950359236608 02-Apr-19 02:49 PM First off, LOL, second, HOLY MOLY conflat batman! 02-Apr-19 02:52 PM I.... don't get the joke? 02-Apr-19 02:52 PM javascript is an overcomplicated mess 02-Apr-19 02:52 PM and its a gross language 02-Apr-19 02:52 PM I dunno I guess thats about the simplicity of it XD 02-Apr-19 02:53 PM oh, ok 02-Apr-19 02:53 PM yeah, chambers like that are just pornographic 02-Apr-19 02:55 PM and then there is me with my little CF 2.75" chamber and worrying about conductance 02-Apr-19 02:55 PM and me and my puny brain forget, thats literally not a problem, you don't have something like THAT 02-Apr-19 02:56 PM conductance is not an issue if you're not after UHV or fast pumpdown 02-Apr-19 02:57 PM I really wish I had some partners in crime local to me to learn with. I know how to hunt down and buy good cheap hardware... I just don't know what to do with it afterwards :) 02-Apr-19 02:57 PM I mean I have almost cryo, I have some turbo, and I have an ION controller on the side if I ever get a pump thats in decent shape lol 02-Apr-19 02:58 PM put up some flyers at a local uni 02-Apr-19 02:58 PM visit a maker space 02-Apr-19 02:58 PM lol unfortunately the two closest unis are software and food, the other is a general mix but a state uni so its probably more washed out with people who just want to get a degree and get out 02-Apr-19 02:58 PM and no local makerspaces AFAIK 02-Apr-19 02:58 PM closest I've gotten so far is @Applied_Ion and his group of friends an hour and half away 02-Apr-19 02:58 PM we have discussed briefly getting some shared space. 02-Apr-19 03:00 PM build your own tiny dune, @Applied_Ion dies the accelerator stuff and you build the neutrino detector 02-Apr-19 03:02 PM LOL that would be awesome 02-Apr-19 03:03 PM I'm getting bad Ideas again, I should go to sleep 02-Apr-19 03:03 PM good night ^^ 02-Apr-19 03:09 PM lol night! 02-Apr-19 03:17 PM I really want a controller for my IGM-400 so I don't have to try and find and use another guage ;; I'd start making a controller if it weren't for someone having one almost done :) 02-Apr-19 07:01 PM Moin 02-Apr-19 10:14 PM @Conmega I guess you're in Poughkeepsie by the sound of things? 02-Apr-19 10:14 PM @Conmega I have the same problem with collecting things for projects that are complex and needs lots of things... it appears like hoarding to some outsides :/ 02-Apr-19 10:14 PM outsiders* 02-Apr-19 10:14 PM (or even insiders like my wife) 02-Apr-19 11:44 PM moin! 03-Apr-19 12:28 AM nacht 03-Apr-19 12:28 AM ordered one of these (but from Amazon for $3 less) https://www.adafruit.com/product/3686 03-Apr-19 12:28 AM figure I'll start with just an ESP8266 and wifi into it for datalog viewing... but will likely at least throw an SD card on too for recording, and probably should eventually add a RTC... but I also plan to make the wifi more stable than it has been in the garage, so can probably just rely on internet time 03-Apr-19 12:28 AM nacht (for realz this time) 03-Apr-19 01:01 AM gute nacht :) 03-Apr-19 01:39 AM moin 03-Apr-19 01:42 AM Using an ATmega328P in a project after doing heaps of ESP8266 stuff. I’m annoyed it has no ROM boot loader! Need to clean up all my stuff to find ISP programmer! 03-Apr-19 05:09 AM @nmz787 yea in Poughkeepsie, and you know nothing about hoarding :P stop by my place sometime and see how I've lost track of the number of shelves I have setup in the basement yet need more at the same time lol 03-Apr-19 10:16 AM So, the Hackaday 2019 prize just started, anyone going to present a project? (tl:dr, I won't) 03-Apr-19 10:17 AM I considered it a while ago, but now I don't think my stuff really fits it lol 03-Apr-19 10:20 AM I thought the same about this year "we want a marketable product" 03-Apr-19 10:20 AM Oh wait that's the criteria? 03-Apr-19 10:20 AM I haven't looked 03-Apr-19 10:20 AM Technically, I would like to maybe try to develop my thrusters into an actual viable marketable system, maybe use it to help fund my work more. Not sure the Hackaday competition is the way I'd want to pursue it, but idk, I'm still trying to think of where to go from here, especially if my tests in the next month or so are successful 03-Apr-19 10:24 AM Thats this years criteria. 03-Apr-19 10:24 AM Made me totally non-interested. 03-Apr-19 10:26 AM is it? I watched the video 03-Apr-19 10:26 AM it heavily implies they are trying to help you bring your idea to market 03-Apr-19 10:26 AM but it doesn't appear to "specify" that? unless there is more than that video in information 03-Apr-19 10:26 AM I really hate how marketie that video is 03-Apr-19 10:26 AM reminds me of some stupid stuff big corporations make up 03-Apr-19 10:28 AM Last year it was "change the world" and the winner was a pretty lame robot arm... 03-Apr-19 10:29 AM I think I could probably do pretty well in this criteria, considering the timing with my own stuff now, but idk. I don't want to design to meet a competition criteria rather than an actual market (kind of like how senior capstone is about writing some bs report and not real engineering lol) 03-Apr-19 10:29 AM I dunno I think the whole hackaday project sharing platform started off as a great thing then devolved into a contest of who takes the prettiest pictures 03-Apr-19 10:29 AM @Applied_Ion I'd post stuff to hackaday if you have time, but don't bend your schedule and plans around them 03-Apr-19 10:29 AM I agree I think you'd be a decent fit for it 03-Apr-19 10:29 AM I'd love to help you somehow if I can, but most of your stuff is way above my head, I know how to do microcontroller based systems automation, I know how to do CAD work, I know how to source random bits of parts and cobble things together, but I know nothing about thruster design and operation :) 03-Apr-19 10:33 AM Lol this isn't my area either, I do pulsed power not thrusters, I just have always been interested in propulsion and plasma technologies, and doing stuff cheaper. A lot of what I'm doing now is running on intuition and educated guesswork based on experience lol, I can't do advanced simulations or stuff like that for this 03-Apr-19 10:34 AM well I'd love to learn anything and everything so if there is anyway I can contribute to your project without big blue getting pissy, aka don't mention my name anywhere in your stuff lol then yea I'd love to help 03-Apr-19 10:34 AM Who is big blue lol 03-Apr-19 10:35 AM you realize I've basically decided to build a fusor because I have this little vacuum chamber and bits together now but I dunno what I'd use it for for my silicon stuff, maybe I can use it for some stuff I dunno and yea boredom lol 03-Apr-19 10:35 AM big blue = IBM 03-Apr-19 10:35 AM contracts and blah blah everything you do belongs to us blah blah 03-Apr-19 10:35 AM its really stupid and outdated 03-Apr-19 10:35 AM Oh lol yeah, that honestly terrifies me about the university 03-Apr-19 10:35 AM I'm doing it all at home, but they are bloodthirsty hawks when it comes to ip and product stuff 03-Apr-19 10:36 AM god... 03-Apr-19 10:36 AM but yea leme know if I can help at all, I'd love to be a part of your project in some way if only to have some of your knowledge rub off on me lol 03-Apr-19 10:37 AM And I see no problem with your motivation to try a fusor, sounds good to me 03-Apr-19 10:37 AM Yeah definitely lol 03-Apr-19 10:37 AM I am quite curious about the uses of a neutron source 03-Apr-19 10:37 AM seems like a fun way to make weird materials 03-Apr-19 10:37 AM Anyone can ask anything whenever lol, and I usually go into more detailed stuff 03-Apr-19 10:38 AM how close are you to getting your chamber all together? are you missing any bits? 03-Apr-19 10:38 AM @GigaSquirrel has been taking lots of great shots trying to figure out my system, I'm sure he has learned some stuff in our discussions lol 03-Apr-19 10:38 AM Technically I have everything ready for vacuum 03-Apr-19 10:38 AM oh sweet 03-Apr-19 10:39 AM But I don't want to seal it up until either a thruster is built and mounted, and/or the accelerator is built 03-Apr-19 10:39 AM ah yea because you don't have any way to access other than a 6" conflat gasket being wasted right? 03-Apr-19 10:39 AM I mean... it wouldn't hurt to seal it up, test everything, ensure you don't have leaks and start de-gassing/etc 03-Apr-19 10:39 AM its 7 bucks to crack it open and re-seal it 03-Apr-19 10:39 AM not a massive cost in the whole outlook of everything 03-Apr-19 10:42 AM Technically the accelerator is shockingly dirt sinple, bit I need to finish cadding the final demensions on stuff before moving forward. True on the gaskets, I need to still qualify the vacuum and cooling system, but I'm being stretched real thin between both projects and gotta save where I can. The major parts that won't move will use copper, but will use viton for interchangeable parts (like the engine mount flange. ) 03-Apr-19 10:42 AM I still have to finish and calibrate the pulsed power supply too, that's way more work than the physical accelerator... 03-Apr-19 10:44 AM Hrm... 03-Apr-19 10:44 AM Oh and if your really worried about leak checking since your chamber is a lot bigger and more complex than mine at the moment... I plan on hopefully getting one of the RGAs on eBay in the future... I could loan it to you at some point if I get one so you could use it for He leak checking 03-Apr-19 10:47 AM That would be pretty awesome lol, hopefully I won't run into any major issues but with this stuff, no matter how much u plan, there are always variables that make it less ideal than planned 03-Apr-19 10:47 AM I need to go up to Albany some weekend coming up and go to a welding supply shop up that way to get some supply gasses so I can start planning for my processes and stuff 03-Apr-19 10:47 AM I think major stuff like Nitrogen and Argon would be pretty handy 03-Apr-19 10:48 AM Nice! 03-Apr-19 10:48 AM because for my silicon process stuff just having a clean backfilled environment will be important 03-Apr-19 10:48 AM but I only have so much money and need so many parts uhg 03-Apr-19 10:49 AM There's no welding supply around you? 03-Apr-19 10:49 AM Yeah, I know what that's like. A million things to do, nit enough money to do it all 03-Apr-19 10:50 AM I'd assume there probably is... But a friend who used to live up there said there was a big store up that way that had everything really cheap and was a great shop 03-Apr-19 10:50 AM What store? 03-Apr-19 10:51 AM I don't know the name off the top of my head... He mentioned it to me a few months ago 03-Apr-19 11:02 AM @GigaSquirrel well... i had another barrel of S2R100 in the past... and i had to buy new... so, it doesn't last as long as you think. :-D 03-Apr-19 11:42 AM @Applied_Ion regardless of the stated goals, the hackadayprice is a bit of a popularity game. So it pays to get in early. 03-Apr-19 11:42 AM And considering how lame stuff qualifies, you have a good shot at getting some money. 03-Apr-19 11:42 AM Because even if you dont win, you might get a couple of grand if all goes well. 03-Apr-19 11:42 AM And that might buy a couple of more caps. 03-Apr-19 11:42 AM Vacuum, high power, physics and so on. And yeah having pretty pictures help 03-Apr-19 11:42 AM Shiny things. 03-Apr-19 11:46 AM @rfs yeah, another reason why I'm hesitant. At the end of the day it may just be more about popularity than engineering. But it's also a good point you bring up that qualifiers still get money even without winning. That would go a huge way towards development, and help massively. Especially since I'm really stretching myself now. 03-Apr-19 11:57 AM to be honest your project will either be sciency enough that people won't understand it and so long as you post lots of cool photos people will vote for it ANYWAY 03-Apr-19 11:57 AM or it will be too sciency and no-one will vote for it because its confusing 03-Apr-19 11:57 AM and or they will assume you don't need the money because you already have this super fancy equipment and your entitled 03-Apr-19 11:57 AM I dunno, again, do it if you have the free time 03-Apr-19 11:57 AM don't let it get in the way of your work 03-Apr-19 11:58 AM Yeah lol, all good and very valid points to consider 03-Apr-19 11:59 AM of-course you'd probably have all of our votes but 20-100 votes means nothing when your competing with a guy who has the RGB LED gaming mouse that will change the world TM 03-Apr-19 12:00 PM somedays I just hate the internet 03-Apr-19 12:00 PM I think its one of those days XD 03-Apr-19 12:01 PM Lol you are not wrong, I think a lot will boil down to popularity and what the general audience feels cool to them 03-Apr-19 12:01 PM I think maybe the route I may take for now is wait until I start running tests on the accelerator and thrusters, and depending if they work and there is more interest, I'll push it further with like a patreon or something. I can't ask for help/money now if nothing works to begin with and I got no results to show yet. Right now I'm just all talk, which means nothing until I can prove it and make an actual working system lol. 03-Apr-19 12:07 PM fair enough, to be honest if you can prove your making progress in research you should be able to just even get contracts for building testing rigs like yours 03-Apr-19 12:07 PM I am sure there are companies who want to do in-house testing but don't have the expertise on staff to build HV chambers and such 03-Apr-19 12:07 PM maybe they have the scientists to RUN them but not to build them 03-Apr-19 12:07 PM that may be a viable buisness for you 03-Apr-19 12:07 PM I know there is a lot of business for building custom stuff like that 03-Apr-19 12:14 PM That would be nice lol, but I won't consider it a personal success unless it works as spec'd. I'm going all in on this, it's a gamble. Either it works as designed or its nothing, in some sense it's the ultimate personal test to see if I really know what I think I know. I have been thinking a lot about it more and more, and it would be cool to do custom systems in these fields. I spend a lot of time gawking at pulsed power companies custom product lines and thinking man, this s### is freakin hot lol, it would be cool to get paid to do it. There is certainly a growing market for micro propulsion stuff, though accelerator, pulsed power, and vacuum is much more niche and highly custom for a smaller crowd. 03-Apr-19 12:14 PM Though I'm sure no one here would object if I were to offer something like a low cost FEL... (possible foreshadowing maybe?!) 03-Apr-19 12:15 PM the other big thing is miniaturization right? 03-Apr-19 12:15 PM I assume thats something you would be-able to work on and advance 03-Apr-19 12:17 PM That's the goal of all this stuff lol, take the big, high power, and expensive stuff and bring it to a more accessible level 03-Apr-19 12:17 PM well... miniaturization doesn't always mean... cheaper... easier... 03-Apr-19 12:17 PM just smaller because you can't expect to send up 400 pounds of control for a 10 pound thruster lol 03-Apr-19 12:17 PM Also FEL? (ignorance yay) 03-Apr-19 12:18 PM True lol, but that's were I think am unconventional, maker based approach shines 03-Apr-19 12:18 PM FEL is free electron laser 03-Apr-19 12:18 PM ah 03-Apr-19 12:20 PM A big and popular physics toy considered well outside the realm of amateur possibility. For now. 03-Apr-19 12:20 PM that would be cool 03-Apr-19 12:20 PM I really need to focus on the home silicon fab thing but to be honest it feels like a really out there project at the moment and I'm allowing the taste of vacuum seed other stupid projects lol 03-Apr-19 12:21 PM Hypothetically speaking, if it were to happen, it may be hard to convince people something of that tech is possible. But then again, also the goal of the MEVI beamline for MeV stuff. 03-Apr-19 12:21 PM It's tough to focus on one thing 03-Apr-19 12:21 PM Way, way too many cool things out there 03-Apr-19 12:21 PM Especially with vacuum systems 03-Apr-19 12:22 PM because I was super focusing on 8" conflat for everything because I was assuming the only way to get silicon was via whole like 6" wafers 03-Apr-19 12:22 PM reliably anyway... 03-Apr-19 12:22 PM but then @Nixie found that company that sells little silicon squares prepared and diced already 03-Apr-19 12:22 PM which is cheap and reliable source 03-Apr-19 12:22 PM I just don't want to design a system that someone couldn't reasonable re-produce 03-Apr-19 12:22 PM and theoretically I'd like to design something that IF for some reason I got other funding for it I could re-produce with all new parts 03-Apr-19 12:22 PM thus the standardization on conflat bits and such 03-Apr-19 12:22 PM and worrying about not getting 2" russian wafers 03-Apr-19 12:22 PM because designing yourself into a corner where your process/design relies on some weird source of old parts is... bad in my opinion... 03-Apr-19 12:22 PM like extremely bad lol 03-Apr-19 12:22 PM but now that I know of these guys 03-Apr-19 12:22 PM https://www.alphananotechne.com/silicon-wafers 03-Apr-19 12:22 PM they have 5x5mm diced squares available for like 48 bucks for 25 of them 03-Apr-19 12:22 PM I could design a silicon fab process around that using like 2.75" conflat 03-Apr-19 12:22 PM which is cheap, available, etc 03-Apr-19 12:25 PM That sounds quite reasonable 03-Apr-19 12:25 PM no need for wafer slicing 03-Apr-19 12:25 PM just each chip individually 03-Apr-19 12:25 PM it would be slow... but it greatly simplifies things 03-Apr-19 12:25 PM I just... look at that MIT or whoever did it research paper of like, we tried to make a sub million dollar fab... and failed... 03-Apr-19 12:25 PM its like. HAH no we can do this for way less I bet 03-Apr-19 12:25 PM even considering NEW parts 03-Apr-19 12:28 PM Sam Zoolof is proof that it can be done for under a million. 03-Apr-19 12:28 PM Well, that depends. For the first iteration, I have one part that is not reproducible, but I am only using to reduce expenditures. However, I will show how it's done with the standard method using low cost materials. As for the stuff like pulse caps, I stumbled across old caps, but there are many ways to do this, a huge amount of approaches, with new and easily homemade stuff. For example, the second stage of my generator will probably rely on a lot of aluminum foil to keep the cost down. In some sense, the pulsed power field has always been one of the ideal, DIY experimental fields making do with scraps. I read an old report were they literally used water beds to help make the pulse forming lines lol 03-Apr-19 12:29 PM Lol 03-Apr-19 12:29 PM I'm reminded of that low vacuum pulsed X-Ray tube made from polycarbonate or lexan or something, with fork & spoon electrodes. 03-Apr-19 12:30 PM @Applied_Ion of-course I mean I am using used old parts, I just mean like... I can get the parts made for reasonable or get them new still 03-Apr-19 12:30 PM "Built to prove a point" 03-Apr-19 12:30 PM like... I just didn't know there was a company that made silicon wafers below 6" anymore 03-Apr-19 12:30 PM and it would cost WAYYYYY too much to try and tell a company, make me 2" wafers or something 03-Apr-19 12:30 PM like thats what I mean by... try not to design in not available stuff 03-Apr-19 12:30 PM Stupid question, if I have some random scrap wafers with stuff on them, could I somehow re-use the other side? 03-Apr-19 12:31 PM @rfs yeah JC Martin did that. Spoon and fork in a plastic cup chamber to xray a knife. 03-Apr-19 12:31 PM Even better if the wafer is prediced and thus falling to small squares? 03-Apr-19 12:31 PM @rfs you could... and can't.... ussually wafers come pre-doped... so one side will have no doping and is super rough not polished the other is generally P doped 03-Apr-19 12:31 PM Because I just recalled that I dumpster dove some random wafers from a local semiconductor company like 15years ago 03-Apr-19 12:32 PM if its... clean... polished... and bear silicon/silicondioxide 03-Apr-19 12:32 PM then yes you could take off the dioxide and dope it yourself if you wanted to? 03-Apr-19 12:32 PM but I mean... 03-Apr-19 12:32 PM its pretty cheap to get wafers/prediced new silicon from that one company 03-Apr-19 12:32 PM they litterally sell on amazon lol 03-Apr-19 12:33 PM Ya. Just recalled that I might have some wafers at my parents place in a shoe box somewhere. 03-Apr-19 12:33 PM I'd recommend saving the time and effort :) 03-Apr-19 12:33 PM already used wafers are more for... looking at... 03-Apr-19 12:33 PM :P 03-Apr-19 12:33 PM Too bad they moved and that was the first time I heard about them, they are fabless now. 03-Apr-19 12:33 PM Would have applied for a summer job as a kid if I knew. 03-Apr-19 12:33 PM oh wow 03-Apr-19 12:33 PM yeaaa... unfortunately tons of companies have done that 03-Apr-19 12:33 PM They literally had a prototype fab 1km from me for 15years. 03-Apr-19 12:33 PM wow 03-Apr-19 12:33 PM well 1-1.5km. 03-Apr-19 12:34 PM I still know of a silicon fab nearish... 03-Apr-19 12:34 PM the old IBM one that sold off to GF then split up into multiple places 03-Apr-19 12:34 PM theres still a section of line run there for one company a friend subcontracts under 03-Apr-19 12:34 PM Always wondered what company used that 3 stories high liquid nitrogen container when I passed the place on a bus. But no signage or anything. 03-Apr-19 12:34 PM My friend said he is going to try and get me in on the cleanroom at some point 03-Apr-19 12:34 PM I have never been in a cleanroom yet 03-Apr-19 12:34 PM like uhg 03-Apr-19 12:34 PM LOL yea 03-Apr-19 12:36 PM I have only passed clean rooms with those obnoxious yellow lights. That's like 10km away. 03-Apr-19 12:36 PM And I think Aalto university or VTT has one or two prototype research fabs in the Otanimei campus. 03-Apr-19 12:37 PM One of you DIY semiconductor people out there need to get the process down good so you can make me some DSRDs and PCSSs lol 03-Apr-19 12:38 PM Tbh I'm quite afraid of HF and other chemicals involved in semiconductor manufacture. 03-Apr-19 12:38 PM HF is scary stuff 03-Apr-19 12:38 PM Yes. 03-Apr-19 12:38 PM Jeri Ellsworth did use weak HF for the diy FET build years back 03-Apr-19 12:38 PM And I guess it could be generated in-situ from NaF or KF. But I ain't doing that in the kitchen. No thanks 03-Apr-19 12:42 PM well thats why I was interested in experimenting with Ion Etching 03-Apr-19 12:42 PM they use reactive ion etch for current stuff, though generally the gases used for that can be more fun than HF if not properly handled/processed lol 03-Apr-19 12:45 PM are some nasty chemicals always required for semiconductor fab? 03-Apr-19 12:47 PM thats the thing I wanted to research more into 03-Apr-19 12:47 PM because its like... there seems to be a million ways to do every step of the process 03-Apr-19 12:47 PM one is most effecient, one is cheapest, then there are like a billion other ways 03-Apr-19 12:47 PM simplest/etc 03-Apr-19 12:47 PM like 03-Apr-19 12:47 PM I think the only real processes that you CAN'T do many different ways are doping... and doping you can only do with a few different chemicals/gases 03-Apr-19 12:47 PM some of which are NASTY 03-Apr-19 12:47 PM some are like... ehhh.. be careful 03-Apr-19 12:48 PM You can't dope purely with implantation? 03-Apr-19 12:48 PM SRIM actually has great resources, background info, and tutorials for applications of semiconductor doping via ion beam implantation 03-Apr-19 12:48 PM That's a major use for the program to begin with 03-Apr-19 12:52 PM ah right I guess you could 03-Apr-19 12:52 PM then yea like... if you use ion etch and ion implantation... 03-Apr-19 12:52 PM like ion etch I believe you want SF6 which is... well you may not want to use that in a low basement type area without really good airflow... 03-Apr-19 12:52 PM but I mean 03-Apr-19 12:53 PM SF6 is inert and nontoxic 03-Apr-19 12:53 PM exactly 03-Apr-19 12:53 PM you'll just suffocate 03-Apr-19 12:53 PM :P 03-Apr-19 12:53 PM Open a window lol 03-Apr-19 12:53 PM Problem is it's expensive 03-Apr-19 12:54 PM but if you have a good well and sealed vacuum chamber your putting the gas in and you have an outlet that plasmas the out gassing then you destroy it all anyway 03-Apr-19 12:54 PM We need it for the accelerator for insulating the rf waveguodes, it's not cheap 03-Apr-19 12:54 PM yea... not sure how much is required for ion etch... 03-Apr-19 12:54 PM it is said you can do ion etch with N2 03-Apr-19 12:54 PM I can't imagine much 03-Apr-19 12:54 PM but it requires 10 times the power 03-Apr-19 12:54 PM which... 03-Apr-19 12:54 PM is a LOT of times lol 03-Apr-19 12:54 PM How much power 03-Apr-19 12:54 PM We got this lol 03-Apr-19 12:54 PM Give me a number 03-Apr-19 12:55 PM I don't have exact values... hrm leme see 03-Apr-19 12:55 PM https://en.wikipedia.org/wiki/Reactive-ion_etching 03-Apr-19 12:55 PM Plasma is initiated in the system by applying a strong RF (radio frequency) electromagnetic field to the wafer platter. The field is typically set to a frequency of 13.56 Megahertz, applied at a few hundred watts. The oscillating electric field ionizes the gas molecules by stripping them of electrons, creating a plasma. 03-Apr-19 12:55 PM ok... hundreds of watts, I assume thats for like a whole wafer 03-Apr-19 12:55 PM if I just want to do a single die... I couldn't image requiring much power at all actually 03-Apr-19 12:55 PM the problem is the RF source 03-Apr-19 12:56 PM Few houndred watts on 13.56MHz ain't that bad 03-Apr-19 12:56 PM god are RF power sources hard to get 03-Apr-19 12:56 PM at-least from what I've see 03-Apr-19 12:56 PM they are massive, heavy, require 3 phase 03-Apr-19 12:56 PM At what power level? 03-Apr-19 12:56 PM and people want like well over a grand for one 03-Apr-19 12:56 PM because 1.5kW single pahse stuff is available in the form of amateur radio amplifiers 03-Apr-19 12:57 PM yea thats where I was thinking of going 03-Apr-19 12:57 PM Yeah 1usd/watt is quite common for linears 03-Apr-19 12:57 PM I was looking at used commercial stuff 03-Apr-19 12:57 PM because the ham linear will do 13.56MHz easily in the 14MHz band settings and 27.12MHz in the 28MHz settings 03-Apr-19 12:57 PM Some older amplifiers might lack the 28MHz range 03-Apr-19 12:58 PM Etch conditions in an RIE system depend strongly on the many process parameters, such as pressure, gas flows, and RF power. A modified version of RIE is deep reactive-ion etching, used to excavate deep features. A typical (parallel plate) RIE system consists of a cylindrical vacuum chamber, with a wafer platter situated in the bottom portion of the chamber. The wafer platter is electrically isolated from the rest of the chamber. Gas enters through small inlets in the top of the chamber, and exits to the vacuum pump system through the bottom. The types and amount of gas used vary depending upon the etch process; for instance, sulfur hexafluoride is commonly used for etching silicon. Gas pressure is typically maintained in a range between a few millitorr and a few hundred millitorr by adjusting gas flow rates and/or adjusting an exhaust orifice. 03-Apr-19 12:58 PM some snippets of important information 03-Apr-19 12:58 PM I'd stay away from weird amps for "26-28MHz" and "24-30MHz Illegla to use on 27MHz" 03-Apr-19 12:58 PM Because those are CB amps and most are the cheapest trash one can find. 03-Apr-19 12:59 PM I think 13.56 is used because... the FCC won't be on your ass 03-Apr-19 12:59 PM Yep 03-Apr-19 12:59 PM though I guess its not super critical for the etch process either 03-Apr-19 12:59 PM And it's harmonics fall on 27.12MHz and 40.660MHz, both of which are license free 03-Apr-19 12:59 PM I know a university lab in Turku used a 100W Yaesu ham rig for plasma generation. 03-Apr-19 12:59 PM But I'd suspect that some hamfesting should yield you a Linear amplifier and some HF rig to drive it 03-Apr-19 12:59 PM BLF188 LDMOS should do 1.2kW output on any HF frequency with 50V VCC or something like that. 03-Apr-19 01:01 PM I have an old 1000W tube AM station amplifier but not what I need for this XD 03-Apr-19 01:01 PM kinda... ended up with that for free 03-Apr-19 01:01 PM That might be buildable for around 500usd in parts and requires around 2-10W drive for 1kW 03-Apr-19 01:02 PM 3 of those massing 833A tubes in there 03-Apr-19 01:02 PM but yea if they need hundreds of watts for lets say a 4-6" wafer 03-Apr-19 01:02 PM then for a 5mmx5mm die... 03-Apr-19 01:02 PM not using SF6 so 10 times power requirement being considered 03-Apr-19 01:02 PM maybe get away with a few hundred watts 03-Apr-19 01:02 PM dunno 03-Apr-19 01:02 PM luckily I have an SEM so after I try something I can just throw it under and see if I etched anything lol 03-Apr-19 01:03 PM if 27MHz is ok then it would be a RM Italy CB amp + 50eur CB radio as driver 03-Apr-19 01:03 PM and a surplus server psu to feed them 12V 03-Apr-19 01:03 PM I mean I don't care what frequency I use so long as I don't piss off the FCC 03-Apr-19 01:03 PM which it will be in a stainless steel chamber thats grounded 03-Apr-19 01:03 PM so it should be OK 03-Apr-19 01:03 PM and for RIE I don't think it matters much at all 03-Apr-19 01:03 PM so long as its like... 10-50Mhz or something like that 03-Apr-19 01:03 PM I remember reading and its not critical 03-Apr-19 01:04 PM FCC does not care at all about the 27MHz band 03-Apr-19 01:04 PM official power limit is 5W AM and 12W SSB 03-Apr-19 01:04 PM None of these dudes run under 1kW https://www.youtube.com/watch?v=ef6z3MaLOrU 03-Apr-19 01:05 PM oh ok cool! 03-Apr-19 01:05 PM There's multiple +30kW CB stations in USA 03-Apr-19 01:05 PM just absolutely zero enforcement 03-Apr-19 01:06 PM I also don't want to piss off any other hams in the area or anything 03-Apr-19 01:06 PM I mean I like to be respectful 03-Apr-19 01:06 PM And 27.12MHz is a legit industrial frequency for plasma generation and industrial heating 03-Apr-19 01:06 PM ah ok 03-Apr-19 01:06 PM Oh yeah, the power levels you need from this are nothing lol, definitely do at home 03-Apr-19 01:06 PM just stay as close as possible to 27.12MHz and hams wont care 03-Apr-19 01:06 PM okie dokie 03-Apr-19 01:07 PM The closest hambands to that are 24.980MHz and 28-29.700MHz, so you are a cool megaherz a way anyway 03-Apr-19 01:07 PM and none of the harmonics fall on hambands 03-Apr-19 01:07 PM yea so can you advise me on what I should purchase or bodge for like... 100-200~W of output for some some experiments? 03-Apr-19 01:08 PM You can build a high power oscillator pretty cheap and easy. No need for 3 phase or any tens of thousands of dollars of equipment 03-Apr-19 01:08 PM I'd look at local craiglist for what's available 03-Apr-19 01:08 PM The oscillator will be oscillating "somewhere around there" 03-Apr-19 01:08 PM I've seen 5kW Russian rf tubes on ebay for like $100 03-Apr-19 01:08 PM Yeah they do that 03-Apr-19 01:09 PM I mean like I said I have those 833A tubes 03-Apr-19 01:09 PM But you need forced air cooling and something around 2-8kV PSU on the anode 03-Apr-19 01:09 PM Eh, that's all easy 03-Apr-19 01:09 PM https://www.rfparts.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/8/3/833A-TAY.jpg 03-Apr-19 01:09 PM hehe 03-Apr-19 01:09 PM they are like 250-300W a tube lol 03-Apr-19 01:09 PM 2-8kv anode supply is nothing 03-Apr-19 01:09 PM They are annoying to source. 03-Apr-19 01:09 PM but mostly joking 03-Apr-19 01:09 PM A coupl of MOTS will do it for you 03-Apr-19 01:09 PM the 833As? sure but I have a box with 3 or 4 of them 03-Apr-19 01:09 PM :P 03-Apr-19 01:10 PM @Applied_Ion Like 6+mots 03-Apr-19 01:10 PM I need to build a home amp with them at some point haha 03-Apr-19 01:11 PM Friends 1.5kW linear had 6x mot and the MOT's ran hot even with the shunts hammered out and additional primary windings. 03-Apr-19 01:11 PM You can also just use less with a CW multiplier to boost the voltage a couple of times 03-Apr-19 01:11 PM Tho for plasma generation things dont need to be clean and can be run in class-c, so that helps. 03-Apr-19 01:12 PM I assume there also has to be some sort of pulsed reactive ion etching as well 03-Apr-19 01:12 PM That is way easier to get voltages and currents you need 03-Apr-19 01:14 PM oh... 03-Apr-19 01:14 PM LOL 03-Apr-19 01:14 PM https://en.wikipedia.org/wiki/Deep_reactive-ion_etching 03-Apr-19 01:14 PM The Bosch process, named after the German company Robert Bosch GmbH which patented the process,[1][2][3] also known as pulsed or time-multiplexed etching 03-Apr-19 01:14 PM heh... 03-Apr-19 01:14 PM I mean its a bit different from that 03-Apr-19 01:14 PM but yea 03-Apr-19 01:14 PM https://www.microsemi.com/document-portal/doc_download/14718-low-cost-1000-watt-300-volt-rf-power-amplifier-for-27-12mhz 03-Apr-19 01:14 PM I mean anything ion/plasma etching will be a million times better than HF 03-Apr-19 01:15 PM https://www.microsemi.com/document-portal/doc_download/14714-500w-class-e-27-12-mhz-amplifier-using-a-single-plastic-mosfet 03-Apr-19 01:15 PM Old-ish appnotes, but modern stuff is just cheaper 03-Apr-19 01:16 PM cool, RF voodoo :) 03-Apr-19 01:16 PM But seriously, unless you have the tubes or got them really cheap, I'd just use modern LDMOS or MOSFET's at <1kW levels 03-Apr-19 01:16 PM oh I know I will 03-Apr-19 01:16 PM I was mostly joking about the tubes 03-Apr-19 01:16 PM Surplus -48V telecom PSU's are easily available and even new they are reasonably priced. 03-Apr-19 01:16 PM I'd only use a tube amplifier if like I got it working already for free lol 03-Apr-19 01:17 PM And 48-60V is safer and easier than 4kV 03-Apr-19 01:17 PM I wasn't lol, though to be fair, you don't need high voltages for this stuff 03-Apr-19 01:17 PM I passed up 48V supplies already for free... 03-Apr-19 01:17 PM Tubes are quite robust, so they can be abused. 03-Apr-19 01:17 PM yea I think you need a few hundred volts for the RIE process? 03-Apr-19 01:17 PM not Kvs for sure 03-Apr-19 01:17 PM Yeah, tubes can take a massive beating 03-Apr-19 01:17 PM So you are good. Even easier lol 03-Apr-19 01:17 PM You don't need kv for sure 03-Apr-19 01:18 PM Modern LDMOS is quite robust these days, only way to kill is to get them to oscillate or overdriving them 03-Apr-19 01:18 PM Related: https://www.youtube.com/watch?v=8ziYqjMQGEQ 03-Apr-19 01:18 PM I find almost all semiconductors grossly weak for what I need... 03-Apr-19 01:18 PM You ware faster 03-Apr-19 01:18 PM I was just about to link it 03-Apr-19 01:18 PM huehue 03-Apr-19 01:19 PM @Conmega I think you can definitely do the plasma etching at home for sure and bypass HF 03-Apr-19 01:19 PM You said even N2 can be used? 03-Apr-19 01:20 PM That does sound Attractive 03-Apr-19 01:21 PM Also you can simulate etching, sputtering, and implantation with SRIM as well, which can be useful at looking at the physics of the process 03-Apr-19 01:21 PM Different gases, input parameters, substrates, etc 03-Apr-19 01:23 PM LDMOS based CB 27MHz amplifier https://www.youtube.com/watch?v=FMVuWqM9BuM 03-Apr-19 01:24 PM hrm dunno where I read that but I am re-reading some stuff 03-Apr-19 01:24 PM Dry etching refers to the removal of material, typically a masked pattern of semiconductor material, by exposing the material to a bombardment of ions (usually a plasma of reactive gases such as fluorocarbons, oxygen, chlorine, boron trichloride; sometimes with addition of nitrogen, argon, helium and other gases) that dislodge portions of the material from the exposed surface. A common type of dry etching is reactive-ion etching. Unlike with many (but not all, see isotropic etching) of the wet chemical etchants used in wet etching, the dry etching process typically etches directionally or anisotropically. 03-Apr-19 01:27 PM Semiconductor manufacturing isn't my area of expertise by any stretch of the imagination, but I think this stuff is well within the home brewer capability, especially to bypass some of the nasty processes. Maybe more time and effort, but you will be that much more of an expert. The MIT report that said they failed to make one less than $1M is because quite frankly academia is grossly wasteful, innefficient, and restricted, especially at doing practical stuff. This is where the maker community shines. Less money, but we do far more fir our investment 03-Apr-19 01:27 PM Does the etching process have to be reactive? 03-Apr-19 01:27 PM Can you just etch with pure argon and brute force it? 03-Apr-19 01:28 PM think that's the only way to really dislodge chunks of material at any rate? 03-Apr-19 01:28 PM I mean most of what your etching is Silicon Dioxide 03-Apr-19 01:28 PM Any material will sputter when subjected to plasma bombardment, just depends on rate you need 03-Apr-19 01:29 PM well and remember, having a photoresist that doesn't get etched when SiO2 does 03-Apr-19 01:29 PM or does at a lesser rate 03-Apr-19 01:29 PM Yeah, so there is purely sputter etching with no reactive gases 03-Apr-19 01:29 PM hrm 03-Apr-19 01:30 PM Less efficient, but maybe the cost of efficiency is worth it at our level 03-Apr-19 01:30 PM yea, again I don't know how they are etching the SiO2 and not the photoresist, or what special photoresist does that 03-Apr-19 01:30 PM Other issues are trenching, redeposition, low selectivity 03-Apr-19 01:30 PM But maybe it's not a terrible tradeoff for simple stuff 03-Apr-19 01:32 PM When do I want to use dry etching? The first thing you should note about this technology is that it is expensive to run compared to wet etching. If you are concerned with feature resolution in thin film structures or you need vertical sidewalls for deep etchings in the substrate, you have to consider dry etching. If you are concerned about the price of your process and device, you may want to minimize the use of dry etching. The IC industry has long since adopted dry etching to achieve small features, but in many cases feature size is not as critical in MEMS. Dry etching is an enabling technology, which comes at a sometimes high cost. 03-Apr-19 01:32 PM I love this, how is it more expensive to dry etch when you consider the cost of acids and disposal of those acids lol 03-Apr-19 01:32 PM I just don't know if this information is old.. .because the last time they used wet etch was in the 80s 03-Apr-19 01:33 PM There also seems to be higher density plasmas using inductively coupled vs more common capacitive coupled systems 03-Apr-19 01:33 PM or if there really is some massive cost to dry etch I am blind to at the moment other than stuff like SF6 and such 03-Apr-19 01:33 PM Pshh, it's only more expensive if you working with brand new custom vacuum systems lol 03-Apr-19 01:33 PM I suppose that's a fair point 03-Apr-19 01:33 PM Remember, industry and academia approach problems differently than we do 03-Apr-19 01:33 PM We are both more restricted but more free in certain areas 03-Apr-19 01:33 PM And, you already have the vacuum system lol 03-Apr-19 01:33 PM That's the major cost 03-Apr-19 01:35 PM I do, I am waiting on CF 4.5" gaskets from LDS... but once I get those I should have a nice 2.75" chamber with those feedthroughs already ready to go 03-Apr-19 01:35 PM I do need to get some gas feed ins and I do need to get some kind of throttle valve for the turbo... 03-Apr-19 01:35 PM Ahhhhh, talking here is so dangerous for my budget, I can't afford to get into more stuff lol 03-Apr-19 01:35 PM :P 03-Apr-19 01:35 PM thats OK! 03-Apr-19 01:35 PM you know why? because I am going to foot the bill for most of it, I just need your knowledge and I can implement your evil ideas for you :) 03-Apr-19 01:35 PM lol 03-Apr-19 01:36 PM Lol fair, I'm mainly interested in the technologies used rather than the end goal itself for semiconductor stuff. Any suggestions that makes it easier for others to do is a win 03-Apr-19 01:36 PM Also, you have a SEM. that's gotta be a crazy powerful asset for doing this stuff at home 03-Apr-19 01:38 PM It very much is. 03-Apr-19 01:38 PM Yeaaa really glad that worked out so well 03-Apr-19 01:38 PM its going to be super critical for characterizing these processes 03-Apr-19 01:38 PM I am super happy to image stuff for others for a small fee too once we get it all aligned and happy in the future 03-Apr-19 01:38 PM But yea I am really all for opensource information on this stuff, so if you can give me the knowledge I need to run the experiments for the community and make this more like lego blocks than multi-million dollar experiments that would be awesome 03-Apr-19 01:38 PM I learn by implementation too so it will help me learn 03-Apr-19 01:38 PM like I may not understand RF stuff... but as I start to build circuits around it and see how sections make other bits work... 03-Apr-19 01:38 PM Its like how I've slowly learned how CRTs work with their HV generation and such... since I've repaired quite a few of them at this point for my vintage computing hobby lol 03-Apr-19 01:38 PM I mayyy be gutting an old scratched/beat CRT for a 20~kV source at some point hehe... 03-Apr-19 01:38 PM its just laying around taking up space 03-Apr-19 01:38 PM it'll be something handy to have around, but I may just take the parts from it to build something a bit nicer than just basically using the HV as is... 03-Apr-19 01:38 PM just considering things I can make at home with junk I have at this point since I'm kinda spent on money atm between stuff I have bought and stuff I NEED to buy lol 03-Apr-19 01:49 PM Well, I will certainly offer whatever assistance I can for these endeavors as well as others pursuing similar vacuum based projects lol. 03-Apr-19 01:50 PM hugs everyone 03-Apr-19 01:50 PM I see you havee been having fun. 03-Apr-19 01:50 PM Sorry I missed the bits I can contribute somewhat to. 03-Apr-19 01:51 PM I think I am going to change the config on my chamber a bit to prepare for some small Ionic etch experiments 03-Apr-19 01:51 PM mostly probably stack another darn 4 way on top of the current one 03-Apr-19 01:51 PM so I can make the fitting opposite of the feedthrough a viewport as an access door with a viton ring 03-Apr-19 01:51 PM so i can easily get samples in and out and attach some parts to that feedthrough 03-Apr-19 01:51 PM mainly to the two BNCs 03-Apr-19 01:51 PM I'd love to get a CF 2.75 6 way but don't know if I want to spend 150~ bucks on one lol 03-Apr-19 06:15 PM https://www.ebay.com/itm/HIGH-VACUUM-16-PORT-MANIFOLD-W-1X-KF40-PORT-TO-16X-KF16-PORTS/332226577709 03-Apr-19 06:15 PM why get a bunch of small roughing pumps when you could just get one massive one and rough ALL THE THINGS AT ONCE 03-Apr-19 06:16 PM Congrats on stumbling into the concept of vacuum revivors 03-Apr-19 06:29 PM revivors?? 03-Apr-19 06:47 PM evenin! 03-Apr-19 06:53 PM hey 03-Apr-19 07:48 PM Woo, charging resistors done for the primary pulsed power stage, compressor coming in tomorrow for the spark gap switches. Releasing my next conceptual thruster design Friday, and hopefully I will begin testing on the pulsed power system next week. I'll see if I can try to do a live firing of the system 03-Apr-19 11:24 PM @Conmega as I mentioned on twitter when @AdamMcCombs posted about his new ion mill... that machine is basically a sputter coater without a sputtering target, and a mask/aperture to form a "beam"... so indeed you can use nonSF6 gasses for etching/milling... the catch is not whether it is effective but rather if it is selective 03-Apr-19 11:24 PM bleach is super effective for killing cancer cells... so are xrays and e-beams... but it isn't selective... they will affect any/all cells in a bulk substrate/media 03-Apr-19 11:29 PM yawn Good morning! 04-Apr-19 03:27 AM Joined the server. 04-Apr-19 08:35 AM moin! 04-Apr-19 02:17 PM @nmz787 yea... I've got a lot of experimenting ahead of me :) Luckily I have TONS of junk wafers I got that are dirty, handled,etc but are bare wafers 04-Apr-19 02:17 PM They are like 6" wafers, so even breaking one of those up into small chunks will give me PLENTY of test subjects. 04-Apr-19 02:17 PM The other fun part will be photoresist testing 04-Apr-19 02:17 PM Also finally got the 4mm hose for the pneumatics for the SEM, I will still need a few more bits and bobs for final main connections and stuff, but I can start re-doing the pneumatics on the SEM now. Woot 04-Apr-19 02:17 PM This is especially since I'm waiting for parts for the roughing pump anyway so I can start on the pneumatics and get that going, not like I'm creating any extra downtime lol 04-Apr-19 02:20 PM But you have that actel? 04-Apr-19 02:20 PM Sure, but I am using that for my other chamber work. I could slap the RV12 back on the SEM but to be honest, I hate the idea that I have to plug the pump in, plug in the SEM, then let it come up... 04-Apr-19 02:20 PM Because remember, the connection for the Hitachi is 100V.... 04-Apr-19 02:20 PM It only outputs 100V and that is NOT enough for the 120V pumps 04-Apr-19 02:20 PM So the only way to permanently replace it would be a relay box 04-Apr-19 02:20 PM The Hitachi is in great shape and pumped fine, I just need those orings and shaft seals which I already ordered... 04-Apr-19 02:20 PM I'm just waiting 04-Apr-19 02:20 PM Mail is slow 04-Apr-19 02:23 PM Yeah... I don't think I ever voltage drop on your scope when running, if you have problems with that easiest fix is to out the RP on another circuit 04-Apr-19 02:27 PM right... again, to get the SEM running with the RV12 I had to hook it up to another circuit before powering up... 04-Apr-19 02:27 PM its a pain... 04-Apr-19 02:28 PM Yeah I was just mentioning I never checked it 04-Apr-19 02:30 PM Yea I did after I blew a breaker in the SEM trying the RV12 on the SEM :P 04-Apr-19 02:30 PM I'll sit in general voice chat as I get some work done, because blah 04-Apr-19 04:34 PM re: transformers for 100V... you don't need a step-down or variac, you can also use a bucking transformer and the price and mass/weight will both be MUCH much less http://sound.whsites.net/articles/buck-xfmr.htm 04-Apr-19 04:34 PM so if you need 100V, you can find a 120V to 20V transformer, and re-wire it for a bucking configuration... you will also not need it to be rated lowe than the kVa needed by the power circuit 04-Apr-19 04:34 PM as the majority of the power flows through the secondary, and the primary:secondary action is only used to buck the 20V difference down to 100V 04-Apr-19 05:01 PM whoa, ESP really has a page on everything -- hadn't heard about bucking transformers, that's awesome 04-Apr-19 05:38 PM @AdamMcCombs with BSE, can you get better topological images for samples with really shallow features? 04-Apr-19 05:38 PM i.e. less edge effects like secondaries yield? 04-Apr-19 06:29 PM @Conmega also, dry etching doesn't really mean less chemicals, it just means not liquid-phase 04-Apr-19 06:31 PM right, there is dry etching that doesn't require flourine gases but selectivity is bad... 04-Apr-19 06:31 PM But I do understand you may need some fun gasses... 04-Apr-19 06:31 PM but disposing of those are generally just... passing the output through some high energy plasma and it breaks them down into more disposable gasses... 04-Apr-19 06:47 PM yeah, it all comes back to chemistry and what sort of processing you're looking to do 04-Apr-19 06:47 PM I've recently been entranced with Atomic Layer Deposition, and it's counterpart, Atomic Layer Etch 04-Apr-19 07:32 PM @nmz787 Depends on the material composition. 04-Apr-19 07:32 PM On a flat surface with just small features, a bse multi quadrant detector will give you info on where there is a change in height, but it will be entirely based on where there is an edge 04-Apr-19 07:32 PM So it wont be bright edges like secondary (in some cases) but it will just be edges 04-Apr-19 08:01 PM @Conmega "1.10 miscellaneous etchants" seems like something you might find interesting, even though it's for wet-etch https://nanolab.berkeley.edu/public/manuals/equipment_manual.shtml 04-Apr-19 11:27 PM Moin! 05-Apr-19 02:27 AM moin 05-Apr-19 02:33 AM just two more barrels and I can go home! 05-Apr-19 03:10 AM Feierabend! 05-Apr-19 03:10 AM Now I've got to buy a suit 05-Apr-19 03:10 AM the "professional" kind, not the protective one 05-Apr-19 03:10 AM this is going to be... interesting 05-Apr-19 07:50 AM whoop whoop 05-Apr-19 07:50 AM my helium 3 detector came! 05-Apr-19 12:24 PM nice! 05-Apr-19 12:26 PM god those prop tubes are sensitive 05-Apr-19 12:26 PM not for detection, but electrical noise 05-Apr-19 12:26 PM first tests are very much in favor of the corona tubes 05-Apr-19 07:01 PM not high vacuum related... but decided to re-try some vhdl... 05-Apr-19 07:01 PM https://media.discordapp.net/attachments/175038434753118208/563866778514489354/DSC_1852.jpg 05-Apr-19 07:01 PM got an EL display out of an old piece of medical equipment 05-Apr-19 07:01 PM https://media.discordapp.net/attachments/175038434753118208/563866113021181976/DSC_1850.jpg 05-Apr-19 07:01 PM have possum lol 05-Apr-19 07:01 PM friend who was helping me with the code likes possums so I was like, eh use this as the test image lol 05-Apr-19 07:01 PM Also yay 1-bit monochrome ditheringgggg 05-Apr-19 07:01 PM could have put this in off topic I guess... I've been up all night 05-Apr-19 07:01 PM Oh, on topic, I got the orings from globalorings for the Hitachi... Just waiting on Granger for the shaft seals and she'll be good 05-Apr-19 07:05 PM The Oxford PlasmaLab system I use is 13.56MHz, both ICP and RF plasma drives (they somehow have different properties for the etch), up to like 3000W. A load lock is used to minimise pump time, with a robot loader thing that automatically moves the wafer into the main vessel. Helium backing cooling for DRIE. A stack of multiple MFCs to support different processes (it’s a research lab not fab) so you have SF6 and C4F8 for Bosch, and O2 as a glorified plasma cleaner, chlorine (for metals etch I think) and maybe some other stuff I can’t remember. 05-Apr-19 07:06 PM neat! 05-Apr-19 07:07 PM And auto-tuning impedance match capacitors to avoid killing the RF driver. The auto match is overridden with manual match parameters during the plasma strike phase to ensure it ignites 05-Apr-19 07:07 PM Ideally, those are the basic components you want 05-Apr-19 07:07 PM SF6 alone should do basic etch, with just RF in from one amp, and you can skip the load lock and just accept pumping down the whole vessel to reduce cost and complexity 05-Apr-19 07:09 PM right I kinda figured I'd need at-least a few hundred watt transmitter, impedance matching to not blow that up, and yes I am thinking at this point I am going to design around doing single dies at a time since well that one company sells them pre-diced 05-Apr-19 07:09 PM like my concern was making it reproducable for others, so if I had to work with a source of wafers, I'd work with a source of wafers 05-Apr-19 07:09 PM but if I can get pre-diced guys... why not use 2.75" conflat which is dirt cheap nearly, and just do really small simple processes 05-Apr-19 07:09 PM need maybe 200-400 watts?? if even? 05-Apr-19 07:09 PM instead of like 3kW 05-Apr-19 07:09 PM save on gas use, etc 05-Apr-19 07:11 PM I use 1000W for “make sure you really killed it” oxygen cleaning but i don’t think you need that much power for etch 05-Apr-19 07:11 PM well I think you can use as low as like 100W its just your etch rate will be like... null... 05-Apr-19 07:11 PM Aw no 05-Apr-19 07:12 PM or it will be bad, I dunno, variables I have not yet played with 05-Apr-19 07:12 PM Now I’m like “this is super cool can we do it” and I’m into it 05-Apr-19 07:12 PM there is a big Asher at work I can pull parts from, that SHOULD have an RF source and everything 05-Apr-19 07:12 PM I have to scope it out for more parts later 05-Apr-19 07:12 PM I believe ICP will give you higher plasma density than capacitive coupled rf, though both would be driven with rf. Note that SF6 is still pretty expensive 05-Apr-19 07:12 PM Distraction from real work ^_^ 05-Apr-19 07:13 PM If you want to look at etch rates, you can use SRIM to simulate this 05-Apr-19 07:13 PM right, I know you can do etch without sf6 but selectivity can be real bad, but its worth a shot, for a massive process it may not matter 05-Apr-19 07:13 PM If you want low capital cost just use wet HF, but cheap simple RIE is a great hack project. 05-Apr-19 07:13 PM Maybe this is dumb but 05-Apr-19 07:14 PM well I wanted to avoid HF for the well inherent dangers of that, not that... I'm afraid of it... 05-Apr-19 07:14 PM I'd say give non SF6 a shot, you have nothing to lose lol 05-Apr-19 07:14 PM but for accessibility 05-Apr-19 07:14 PM nothing is dumb lol 05-Apr-19 07:14 PM its just... maybe not the best way of doing it :P 05-Apr-19 07:14 PM Even if it's not selective, I would use it to refine your process before spending $$$ on sf6 05-Apr-19 07:14 PM What if we abuse some organofluorine refrigerant like 134a which is cheaper 05-Apr-19 07:14 PM yea I was wondering that 05-Apr-19 07:14 PM I did see info on R-12 actually being a usable etchant 05-Apr-19 07:14 PM like that was used for a long time supposedly for certain processes 05-Apr-19 07:14 PM my grandfather mayyyy still have a canister somewhere... 05-Apr-19 07:14 PM but thats not a good long term thing 05-Apr-19 07:14 PM but newer refrigerants... I mean... I think the important thing is the flourine in there 05-Apr-19 07:14 PM but I am no chemist and I have no idea how any of this reacts... I am trying to pick up bits and pieces of chemistry as it flys by me here :P 05-Apr-19 07:14 PM but I am no chemist at the moment 05-Apr-19 07:16 PM I think the way Bosch works with C4F8 is it forms a Teflon-like protective side wall as you alternate between SF6 and C4F8 cycles 05-Apr-19 07:16 PM Not sure if that carbon will be a problem in the refrigerants 05-Apr-19 07:18 PM right, I have seen a lot about the bosch process, that would be awesome for doing home MEMs stuff I'd think 05-Apr-19 07:18 PM And while that's awesome, that is really not a necessity for simple logic :) 05-Apr-19 07:18 PM But yea there are tons of refrigerants around... 05-Apr-19 07:18 PM there may be one that can be made to work, even if it may need some pre-processing chemically, so long as its not super dangerous or crazy complex... I'd consider that worth the effort 05-Apr-19 07:18 PM Its like for fusors... you either buy deuterium...or get some heavy water and make your own :) 05-Apr-19 07:18 PM https://pubchem.ncbi.nlm.nih.gov/compound/1_1_1_2-tetrafluoroethane#section=Use-and-Manufacturing 05-Apr-19 07:18 PM It is used as a foam blowing and dry etching agent. 05-Apr-19 07:18 PM hrm, so apparently at some point, someone doing something has used R-134a for an etching agent... 05-Apr-19 07:18 PM Totally worth a shot, its readily available enough... 05-Apr-19 07:18 PM oh neat! 05-Apr-19 07:18 PM https://www.sciencedirect.com/science/article/pii/S0040609014002971 05-Apr-19 07:18 PM apparently you can use it for depositing a flourocarbon film to make a super hydrophobic surface :) 05-Apr-19 07:18 PM So yea I guess there is a flourocarbon deposition issue 05-Apr-19 07:18 PM still seems like something fun to play with 05-Apr-19 07:28 PM CHF3 is used as a SiO2 and Si nitride RIE etchant, but not for Si I think - it’s also a refrigerant 05-Apr-19 07:28 PM If i built the apparatus I would try R134a - it’s plausible 05-Apr-19 07:29 PM Yea I definitely will. I am like... 80% of the way there to be honest with my little build... 05-Apr-19 07:29 PM I just need the RF stuff, and the air fittings/adapters to get a pressure regulation/feed going... 05-Apr-19 07:29 PM I have a MFC or two laying around 05-Apr-19 07:29 PM the real problem at the moment is I have no valve to throttle my turbo... 05-Apr-19 07:29 PM there are a lot of hacky ways I could do it... but yea kinda been hunting out some valves on ePay 05-Apr-19 07:29 PM but money has been tight so been kinda trying to keep myself distracted and uh do more research instead of just doing stuff like I normally do lol 05-Apr-19 07:29 PM I'm a very... hands on have to try something type person... I assume I have some major adhd that no-one has never noticed lol 06-Apr-19 01:24 AM moin! 06-Apr-19 03:05 PM Moin! 06-Apr-19 03:08 PM @Applied_Ion or any one else do you have experience with UHV and non evaporable getter pumps? 06-Apr-19 03:23 PM @AdamMcCombs I have never used them directly myself, though I know they are popular at CERN. Molflow actuslly has a couple of tutorials looking at NEG pump simulations. 06-Apr-19 03:23 PM UHV I have experience with ion, but not NEG 06-Apr-19 03:24 PM Oh cool 06-Apr-19 03:24 PM Ion just doesn't quite get me to -12... 06-Apr-19 03:24 PM At least not in a dif pumped feg 06-Apr-19 03:24 PM It should, we can get to 10^-13 with ours 06-Apr-19 03:25 PM Gas load in a feg during emission is the problem 06-Apr-19 03:25 PM Oh yeah lol diff pump is tough, we use a turbo to prepump, them do extended baking with the ion pump 06-Apr-19 03:25 PM It can take a real long time, but definitely do able. So do you need 10^-13 during FEG operation? 06-Apr-19 03:26 PM What I'm trying to do is get pressure low enough that I don't embed gas in the lattice of the 310 feg to try and hit a quazi stable extended emission regime 06-Apr-19 03:27 PM What's FEG stand for again? 06-Apr-19 03:27 PM Field emission electron gun 06-Apr-19 03:27 PM Right lol 06-Apr-19 03:27 PM What's your ion pump speed? 06-Apr-19 03:27 PM During operation we use 2 for our test injector. A small one right at the gun, and a large 200 l/s one dowmstream, though pumping is choked since it's connected from 8" to 2.75" bellows 06-Apr-19 03:29 PM Apparently it's possible to retrofit old cold guns with a massive amount of pumping speed and get 10-100 times more brightness during the stable emission platou 06-Apr-19 03:29 PM If you need pumping speed, there is always cryo lol, but that opens up other challenges lol 06-Apr-19 03:29 PM Stock ones are pretty small, 50-100 lps 06-Apr-19 03:29 PM Cryo doesn't work on high res sem/tem because of vibrations 06-Apr-19 03:30 PM Do you have a NEG? 06-Apr-19 03:30 PM Unfortunately no 06-Apr-19 03:30 PM I don't even have a personal feg setup yet 06-Apr-19 03:31 PM What level does your ion pump setup get to now with diff backing? 06-Apr-19 03:31 PM Also what chamber volume you working with? 06-Apr-19 03:31 PM I have been looking to get a certain old that sem that used semi in lens optics to get better resolution than any scope of it's day 06-Apr-19 03:32 PM Wait, I forget of we get to 10^-11 or 10^-13, it's been so long since we have had our setup run lol 06-Apr-19 03:33 PM -11 is very common for most feg systems 06-Apr-19 03:33 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_20190406-153244-85A48.png 06-Apr-19 03:33 PM This is what I'm trying to do 06-Apr-19 03:33 PM The ion pumps on these setups currently have a base pressure of -11 06-Apr-19 03:34 PM 10^-13 takes a massive amount of baking time at as high temp as possible 06-Apr-19 03:35 PM Yeah I know... 06-Apr-19 03:35 PM At that point you are getting into permeation of hydrogen through bulk metal lol 06-Apr-19 03:35 PM Hydrogen is relatively ok, which is why Hitachi was able to use neg to do this 06-Apr-19 03:35 PM Apparently Hitachi was able to just put a bunch of neg in front of an ion pump on a really old system and get these results 06-Apr-19 03:37 PM Yeah, that's the only gas left at that point lol 06-Apr-19 03:37 PM We get 10^-11, I remember now, 10^-13 is real tough 06-Apr-19 03:37 PM Are there even any negs on ebay? 06-Apr-19 03:40 PM I just need mid 12 fortunately 06-Apr-19 03:40 PM Yeah I was wondering if you had a vendor for neg... 06-Apr-19 03:48 PM Oh lol, we have never used one at our facilty, we don't go below 10^'11 06-Apr-19 03:48 PM You can hit 10^-12 with ion I think, but that's getting to the limits lol 06-Apr-19 03:48 PM I'm looking more into it now, pretty interesting challenge 06-Apr-19 03:49 PM And the fact that it can be retrofit to an old feg system is very attractive... 06-Apr-19 03:55 PM Is there any reason you can't use evaporable getter pumps? It looks like stuff at cern combines ion with neg, as well as TSPs 06-Apr-19 03:57 PM It would be accommodation, mounting neg before the igp 06-Apr-19 03:57 PM I don't know if there is a reason that tsp won't work 06-Apr-19 03:59 PM Something that also seems to help is coating the SS surfaces with NEG materials. I think the biggest thing though in order to achieve this will be bringing the gas load of the walls to XHV levels, so a crap ton of baking for a long time over multiple sessions. That's really the only way, you gotta get the SS down to 10^-13 torr-l/s/cm^2 06-Apr-19 03:59 PM SS will hit that, but it's baking and pumping for stupid amounts of time 06-Apr-19 03:59 PM You will probably need the TSP to help boost pumping speed with your ion pump too 06-Apr-19 03:59 PM NEG seems to have an advantage due to its high pumping speed of hydrogen 06-Apr-19 04:06 PM It looks like tsp works, it's just harder to modify on to a sem 06-Apr-19 04:07 PM You gonna build your own tsp? 06-Apr-19 04:07 PM On the test rig that Hitachi ran they used tsp on it 06-Apr-19 04:07 PM But on their retrofit sem they ran neg 06-Apr-19 04:07 PM It seems like the hydrogen pumping is what does it 06-Apr-19 04:07 PM Hydrogen embedding in the tungsten tip is what appears to be causing the instability after flashing 06-Apr-19 04:11 PM Yeah, that's the only thing left at that point. Hmm, is it possible to buy the material used in neg and make your own? 06-Apr-19 04:11 PM Or contact a company that does metal sintering and have them make something like that if you got the specs? 06-Apr-19 04:13 PM That seems possible, but tsp might be cheaper 06-Apr-19 04:14 PM Yeah, if a tsp will work, I'd say go for that first 06-Apr-19 04:14 PM The gun already had conflat on it so it shouldn't be to hard to put a larger chamber on 06-Apr-19 04:15 PM You will want super pure Ti, I read in some presentation that TSPs can have a possibility to outgas methane if not using super pure Ti 06-Apr-19 04:15 PM You will also need to use LN2 for the TSP to be effective at that level to cool the walls 06-Apr-19 04:17 PM I was just looking at that 06-Apr-19 04:17 PM That's why Hitachi didn't use it on the SEM 06-Apr-19 04:17 PM Ln2 boiling off causes to many vibrations 06-Apr-19 04:18 PM That much? 06-Apr-19 04:18 PM Yeah it's a pain 06-Apr-19 04:18 PM For most SEMs it doesn't matter 06-Apr-19 04:19 PM Couldn't you dampen the vibration? 06-Apr-19 04:20 PM But it's why ultra high resolution instruments use cryo gass with laminar flow cooling paths 06-Apr-19 04:20 PM Vibration dampening something mounted directly to the column/gun in that way is really hard 06-Apr-19 04:20 PM I think I'm just going to have to source neg 06-Apr-19 04:20 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181130_182635-EF799.jpg 06-Apr-19 04:23 PM https://www.saesgetters.com/products-functions/products/getters/non-evaporable-getters/coated-strips 06-Apr-19 04:23 PM This place sells NEG strips 06-Apr-19 04:23 PM SAES St707 appears to be a common material 06-Apr-19 04:23 PM Maybe give these guys a call, see if they can quote you for some strips 06-Apr-19 04:23 PM Unfortunately it appears this stuff is really mainly used in accelerators, making it tough to find companies that supply it, and at a reasonable cost 06-Apr-19 04:26 PM I'll have to give them a call on Monday 06-Apr-19 04:27 PM There may be other places that provide SAES St707 coated strips, but probably not that many 06-Apr-19 05:17 PM @AdamMcCombs you mentioned that hydrogen adsorption on the FEG causes issues, which I assume is a tungsten tip? Are you using commercial or diy? Are there other materials that are used which may have better stability or can do what you want at relaxed vacuum levels? 06-Apr-19 05:17 PM Diy, tungsten is what works for cold feg 06-Apr-19 05:18 PM You can get cold field emission from any material under the right conditions though 06-Apr-19 05:18 PM The systems run just fine right now, I just think I can get a bit more resolution out if I can improve vacuum 06-Apr-19 05:18 PM Yeah, but you can't get the probe size and energy spread with other materials 06-Apr-19 05:18 PM There are some other exotics that can work, but aren't practical 06-Apr-19 05:21 PM What determines energy spread? Probe size is just how small you can get the tip, correct? 06-Apr-19 05:21 PM Vacuum stabilized cold feg is pretty much the best emitter out there at this point, I just realized that I might be able to stabilize an older instrument 06-Apr-19 05:21 PM A lot 06-Apr-19 05:23 PM The field emission I specialize in is at a radically different level lol, not too familiar with these types of feg 06-Apr-19 05:24 PM One part of it is the temperature of the material, but things ranging from what lattice (eg 100, 110, 310) you are running to how good the material is in vacuum also have large effects 06-Apr-19 05:24 PM The problem with cold feg is is that it is so sensitive to everything 06-Apr-19 05:24 PM Non vacuum cold feg works because after the initial drift any ions that implant themselves in the surface do so in a stable fashion until the lattice is filled and you start to increase current again at the cost of probe size, energy spread, and noise 06-Apr-19 05:24 PM At a certain point you will get a vacuum arc and that's that 06-Apr-19 05:24 PM Additionally (in sem) you want as low of a final voltage as possible, while still keeping the wavelength low low in optics 06-Apr-19 05:24 PM So you ened up with all the magnetic static hybrid lenses that accelerate the electrons up before entering the lens the back down again 06-Apr-19 05:24 PM But you can only do that so much, so you end up having to uses sources that can run a really low kv for extraction 06-Apr-19 05:31 PM What voltages we talking? 06-Apr-19 05:31 PM I'm curious what other materials have been used 06-Apr-19 05:32 PM Final voltage on sample as low as 50 06-Apr-19 05:32 PM For cold feg or feg in general? 06-Apr-19 05:39 PM Cold feg. Like 50v extraction only? 06-Apr-19 05:39 PM Oh no that's final voltage 06-Apr-19 05:39 PM Around 1 kv for extraction is pretty useful in some cases 06-Apr-19 05:39 PM The new columns have all kinds of different modes and different deceleration acceleration profiles, I really can't keep track of all of them... 06-Apr-19 05:50 PM That's way lower than I was expecting lol 06-Apr-19 05:50 PM Yeah no its a complete pain 06-Apr-19 05:50 PM For cold mono crystal w is about the only thing that you can use that has the probe size 06-Apr-19 05:50 PM For high brightness sources zirconium is common 06-Apr-19 05:50 PM But those are more for e beam stuff 06-Apr-19 05:50 PM There also the distributed feg guns 06-Apr-19 05:50 PM I think those are made in a mems process, I don't know the materials involved though 06-Apr-19 05:50 PM But at the end of the day you get something like a .3ev spread, feed that through a mono chromator and damn. 06-Apr-19 05:57 PM What type of spread are you aiming for? 06-Apr-19 05:57 PM Pretty cool stuff, waaaay different than what I'm used to 06-Apr-19 06:00 PM Sem if you can hit .1 or .2 and are running semi in lense with beam deceleration and a through the lens electron detector with magnetic compensated static extraction detector then you are just about the the therotical limit that's practical 06-Apr-19 06:00 PM Tem though 06-Apr-19 06:00 PM 0 06-Apr-19 06:00 PM In a 300kv mono chromated with multiple sperical correction energy spread is probably your limiting factor 06-Apr-19 06:00 PM Then when you go to the atomic resolution 60kv systems energy spread is definitely your limiting factor 06-Apr-19 06:00 PM There are now systems that can do individual atmom imagine in 2 lattice layers at 30kv which is just insanity 06-Apr-19 06:04 PM Jeez that's crazy 06-Apr-19 06:04 PM Yeah the high end of this is just ludicrous 06-Apr-19 06:04 PM The resolution record is currently held by a 30kv system that did single electron difraction tracking and computation stuff that is really amazing 06-Apr-19 06:04 PM They needed a high resolution high speed direct electron camera capable of picking up individual electrons on some insanely short time base 06-Apr-19 06:09 PM You aiming for that one day? 06-Apr-19 06:09 PM In sem no way 06-Apr-19 06:11 PM You got this lol 06-Apr-19 06:12 PM The systems that do this are really only useful for solving very specific problems 06-Apr-19 06:12 PM I see some other areas that can make way more accessible systems way more useful in other fields 06-Apr-19 06:12 PM If you want to see some really crazy stuff look at the atomic resolution time domain scopes 06-Apr-19 06:12 PM Able to watch reactions happen on the atomic scale and at a time domain that let's us understand processes 06-Apr-19 06:17 PM That's pretty insane 06-Apr-19 06:18 PM They thermal assist field scopes with phemto second lasers guided into the emmision chamber with in vessel optics the get photo field emmision 06-Apr-19 06:18 PM Then they use uktra fast CCDs with static deflectors above the camera, so they steer the beam to different parts of the sensor every laser pulse 06-Apr-19 06:18 PM Then they still ran out speed, so they started running the beam on the same part of the sensor multiple times, and used video compression algorithms to pull multiple frames out 06-Apr-19 06:54 PM A photo emission gun build would be pretty fun to do 06-Apr-19 08:56 PM Fascinating stuff Adam 07-Apr-19 12:40 AM Moin! 07-Apr-19 01:00 AM what's "dead gauges society"? 07-Apr-19 01:02 AM Per @qualia " Originally the server was going to be called the Dead Gauge Society, after a particularly funny inside joke on twitter. @qualia.xm wrote this as the original channel introduction before we switched the name to Vacuum Hackers. Why the name? One fateful evening in October of 2018, on Twitter, Qualia (@profanegeometry) eavesdropped on a conversation between @Gigasquirrel and Tom McCarthy (@FusorFusion) that would change the course of history forever. Tom was looking for a high vacuum gauge for <10^-3 mbar measurements, to which GigaBecquerel provided a link to the notorious Fusor Forums documenting the repair and reverse-engineering of a low-cost analog-readout ion gauge available en masse on eBay (namely, the Instrutech IGM-400). Days later, Qualia received their very own gauge in the mail and posted a picture of it, to which a deluge of like-minded vacuum folx summarily took notice and bought their own. Dave A (@dave_32768) proposed starting a club; @Nixie_guy suggested the name "Dead Gauges Society" (à la 'Dead Poets Society'), and the rest... is history. " 07-Apr-19 01:03 AM we need a bot that posts just that everytime someone asks 07-Apr-19 04:23 AM moin 07-Apr-19 04:59 AM O captain, my captain! 07-Apr-19 04:59 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-59EAD.jpg 07-Apr-19 04:59 AM I kinda want one of those glass gauge heads for no reason other than they look cool 07-Apr-19 05:06 AM glass gauge? 07-Apr-19 05:06 AM I don't see any glass there 07-Apr-19 05:15 AM That sort of reminds me of the insides of a vacuum tube. All the parts are there, a directly heated kathode, grid and anode. 07-Apr-19 05:16 AM Yep 07-Apr-19 05:46 AM <0xDBFB7#9254> it's a triode where the grid is air 07-Apr-19 05:46 AM <0xDBFB7#9254> note: this is false 07-Apr-19 05:46 AM on so many levels 07-Apr-19 06:15 AM <0xDBFB7#9254> Edgar Wright movie with ionization gauges: 07-Apr-19 06:15 AM <0xDBFB7#9254> the town's end 07-Apr-19 06:15 AM <0xDBFB7#9254> nick frost plays a cryopump 07-Apr-19 06:15 AM <0xDBFB7#9254> pegg plays a dishonourable discharge in a downwards spiral 07-Apr-19 06:15 AM <0xDBFB7#9254> four friends that wanted to get annihilated, except then they get caught in an avalanche 07-Apr-19 06:30 AM discharge in a downwards spiral? 07-Apr-19 06:30 AM sounds like a penning 07-Apr-19 08:19 AM Half the grid is missing (in my photo) but maybe it will still kinda work 07-Apr-19 08:56 AM beep 07-Apr-19 12:55 PM @a_quiet_scientist what does that even attach to? It's clearly to seal to some surface with an oring Grove for an oring or its like iso-K or something wierd. 07-Apr-19 02:34 PM Some weird nonstandard vacuum flange yes 07-Apr-19 02:55 PM is there a wiki associated with this room? like where can I find the info on the IGM-400? 07-Apr-19 04:12 PM That would be neat idea 07-Apr-19 04:13 PM Yea I have never really felt like contributing to a wiki before in my life... 07-Apr-19 04:13 PM This is the weird flange that mates to the big ion gauge head 07-Apr-19 04:13 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-AA1BF.jpg 07-Apr-19 04:13 PM But this group has enough people who I know would be HELPING ME, I'd love to return the help and help them with info if I can. 07-Apr-19 04:13 PM Yeah I could do that 07-Apr-19 04:13 PM So having a wiki would be great, we have the domain vacuumhackers.com I think so we should do a wiki.vacuumhackers.com 07-Apr-19 04:13 PM I could probably spin something up on a computer here at my house to host, I have gigabit fios :) 07-Apr-19 04:13 PM @AdamMcCombs lets talk about this later 07-Apr-19 04:15 PM TIL after chasing it down - Loctite 9492 is the same thing as Hysol 1-C when it is sold in EU/AU (it’s the same as Torr-Seal) which helps a lot because it was impossible to find any seller of Hysol 1-C 07-Apr-19 04:16 PM neat 07-Apr-19 10:12 PM @Conmega never thought of contributing to a wiki??? damn, that's bizarre to me! (being that this group is so technically adept) 07-Apr-19 10:12 PM I bet diyhpl.us (hosted at Portland State University) would let us spin up something there too 07-Apr-19 10:12 PM it would be backed by GIT too 08-Apr-19 12:15 AM moin 08-Apr-19 01:58 AM nacht 08-Apr-19 03:30 AM @nmz787 http://fusor.net/board/viewtopic.php?f=10&t=12165 08-Apr-19 03:43 AM ah nice 08-Apr-19 03:43 AM but already found that thread 08-Apr-19 03:45 AM that's all the Info I got on the gauges 08-Apr-19 03:47 AM I’m thinking Ta might be a really good fusor grid material. It’s melting point is really high, slightly lower than W but still up there, and it’s much more malleable and easier to work than W. 08-Apr-19 03:48 AM huh, I might play around with that 08-Apr-19 03:48 AM bc working with W is a real pain in the... 08-Apr-19 09:27 AM but in private Wolfram is a nice guy 08-Apr-19 09:28 AM >.< 08-Apr-19 10:23 AM @GigaSquirrel thanks, I also found that last night, but it's still a little unclear to me... for example it seems to say not to turn it on before a certain level of vacuum is attained, but does it sense that itself and fail-safe, or do I need another detector/sensor and be careful when I turn it on (or turn it off) 08-Apr-19 10:27 AM It slowly ramps up the filament in 5-10 seconds, measuring pressure during that time 08-Apr-19 10:27 AM if the pressure is too high it turns off to protect the filament 08-Apr-19 10:27 AM but if you do that in air the filament will still reach a couple hundred degrees before it turns back off, likely killing it 08-Apr-19 02:02 PM woot, got my LDS order, will be swapping out the CF 4.5" tonight and re-trying my chamber, though I have a TON of different bits and bobs I just got, I should probably explore other options for chamber stuff and attachments hrmm 08-Apr-19 02:02 PM I also have to build some kind of frame, which will be some fabrication from either bits of wood or metal scrap I have laying around 08-Apr-19 04:06 PM https://www.technologyreview.com/s/613267/borophene-the-new-2d-material-taking-chemistry-by-storm/?utm_source=pocket-newtab 08-Apr-19 04:06 PM vapor deposition on silver? seems.... easy enough :) 08-Apr-19 05:47 PM yea this trap is not clean.... 08-Apr-19 05:47 PM inputs and outputs are filthy 08-Apr-19 05:47 PM so its not... refurbished... 08-Apr-19 05:47 PM uhg hate ePay sometims 08-Apr-19 05:47 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1877-6F22E.jpg 08-Apr-19 05:47 PM Nice... Ffs 08-Apr-19 05:47 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1879-3C532.jpg 08-Apr-19 05:47 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1878-9D4A3.jpg 08-Apr-19 07:25 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1880-06331.jpg 08-Apr-19 07:40 PM oh darnit... 08-Apr-19 07:40 PM I thought this hastings teledyne gauge was like an ion gauge... 08-Apr-19 07:40 PM nope... just thermocouple 08-Apr-19 07:40 PM so only goes down to like -4 ffs 08-Apr-19 07:49 PM uhg wtf 08-Apr-19 07:49 PM now that I've swapped out the conflat ring I can't get the roughing pump to get the chamber below 1~Torr 08-Apr-19 07:49 PM like... unless that trap is outgassing like hell and loading the heck out of the pump 08-Apr-19 07:49 PM well now its below... 08-Apr-19 07:49 PM veryyyy skiwky 08-Apr-19 07:49 PM hrmmm 08-Apr-19 07:49 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-C0CF9.png 08-Apr-19 07:49 PM that little up jut was me closing the roughing valve then opening it again 08-Apr-19 07:49 PM I was wondering how fast it would rise back up 08-Apr-19 07:49 PM I'll let this rough for a while... 08-Apr-19 07:49 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1881-1BB8D.jpg 08-Apr-19 08:09 PM Pretty colors 08-Apr-19 08:09 PM Hrm I don't like how the pump oil is starting to look... Cloudy... 08-Apr-19 08:09 PM @AdamMcCombs didnt you say cloudy means... Oxygen... This sieve trap I have no idea what it was used with in the past... Is this a concern? 08-Apr-19 08:09 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1882-22330.jpg 08-Apr-19 08:09 PM Haven't seen it like this before... 08-Apr-19 08:09 PM Or is that just a sign of high gas load? 08-Apr-19 08:09 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-575CC.png 08-Apr-19 08:09 PM I only got down to like 0.5~ Torr still after a long time 08-Apr-19 08:13 PM @Conmega cloudy oil usually means a lot of water vapor 08-Apr-19 08:13 PM I only torqued the CF 4.5 down to like... 11~ FT lbs but yea 08-Apr-19 08:13 PM hrm ok maybe this edwards trap is just loaded with vapor, I'll try removing it and seeing what I can do 08-Apr-19 08:14 PM Are you using fresh zeolite? 08-Apr-19 08:14 PM No... the seller labeled it as "remanufactured" so I assumed considering it was sealed pretty well, it was referbed.... 08-Apr-19 08:14 PM but yea... with how dirty it was this guy was an idiot 08-Apr-19 08:14 PM Oh yeah lol I wouldn't reuse the old stuff, I went with fresh fill, no issues at all with it 08-Apr-19 08:14 PM I'll have to get some and re-pack this later 08-Apr-19 08:14 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-76602.png 08-Apr-19 08:14 PM I wonder if that was the outgassing.... 08-Apr-19 08:32 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1884-929CD.jpg 08-Apr-19 08:32 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1883-CEF2E.jpg 08-Apr-19 08:32 PM I think the MKS gauge is bad... 08-Apr-19 08:32 PM I mean it works, but it bottoms out earlier than it should 08-Apr-19 08:32 PM it may have contamination or something 08-Apr-19 08:32 PM guess thats what I get for relying on a used gauge 08-Apr-19 08:32 PM this teledyne gauge kept going lower, past 1 micro of mercury, after the MKS gauge basically stopped dropping 08-Apr-19 08:32 PM so... yea... 08-Apr-19 11:30 PM moin 09-Apr-19 05:25 AM Hello, Could you tel me What are the best practices to follow when My UHV chamber need to go to normal atmosphere ? I’masking to do that without breaking the system ? (I can open a valve but is there any safety procedure ? Thanks for answer . Yann @ NextGenQ 09-Apr-19 05:30 AM @yann35 what kind of UHV system are we talking about here? 09-Apr-19 05:31 AM A 10-10 / 10-11 torr 09-Apr-19 05:31 AM What kind of hardware do you have? Detectors, cryo, or anything else? 09-Apr-19 05:31 AM What is the chamber used for? 09-Apr-19 05:33 AM For now I have noting (purchase are in progress) but I need to have a turbo pump , a ion pump , a chamber with many viewport . Usage = quantum computing with ion trap in the chamber 09-Apr-19 05:34 AM Yeah big thing is just vent with nitrogen 09-Apr-19 05:34 AM An make sure that on your nitrogen vent line you have a very low pressure regulator, like 2-3 psi 09-Apr-19 05:34 AM Might want to put some type of needle valve on as well to enable to to slow the turbo down faster, but if you are not venting frequently I would not bother 09-Apr-19 05:34 AM If you can I also recommend a constant flow of N2 into the system while you have any ports open. It will significantly decrease pump down time. When do servicing the system, just bring it down to vacuum on the turbo at least, even if you are not going to try to start up the ion pumps for over night storage. If its not possible don't bother, but it can be very helpful. For your application you need to make sure that you have a good ion shield or no line of site from the ion pumps to your main chamber. Ion cross talk is a pain. 09-Apr-19 05:34 AM Also if you are not using a dry rotary pump, be sure to molecular trap. Back streaming oil during startup is a hard thing to fix on ion pumps, that much hydrocarbon contamination can cause real problems. 09-Apr-19 05:43 AM Thanks for the quick reply @AdamMcCombs 09-Apr-19 05:44 AM Yeah no problem. If you have any more questions feel free to ask! Im not always this fast at replying... Especially this week. I'm working in the sub basement of a university. 09-Apr-19 05:47 AM @yann35 i use N2 or Ar for venting 09-Apr-19 05:47 AM of the ion trap chamber 09-Apr-19 05:59 AM @N00N How is your system going? 09-Apr-19 06:05 AM @AdamMcCombs you mean if i have results like ported DOOM to the QC yesterday? 09-Apr-19 06:05 AM @AdamMcCombs unfortunately no 09-Apr-19 06:06 AM In that case how is the chamber coming? 09-Apr-19 06:07 AM ah ok, you mean the vacuum stuff alone? well - it sucks eh pumps down 09-Apr-19 06:07 AM we will see if it still works with all the electronics foo in it 09-Apr-19 06:18 AM @AdamMcCombs according to the measurements it reaches < 10^-11 mbar 09-Apr-19 06:18 AM if that is the question 09-Apr-19 06:18 AM but the 'exact' quality of the vacuum with the electronics inside i can only calculate via the ion loss rate of the trap etc 09-Apr-19 06:18 AM optimistically i'm app. 3 months away from acquiring that necessary data 09-Apr-19 06:18 AM (optimistically because it kinda implies that all relevant elements are up and running properly) 09-Apr-19 06:18 AM oven, trap (incl electronics) photoionisation set-up, cooling lasers and the imaging system counting the fluorescent ions 09-Apr-19 06:18 AM and the vacuum stuff of course 09-Apr-19 06:46 AM @AdamMcCombs or was the question about the method of venting it? yeah, with a needle valve 09-Apr-19 06:46 AM @AdamMcCombs like you have recommended 09-Apr-19 05:51 PM Hmmm. I finally got the primary stage wired with all the switches, resistors, and air hoses installed. Did a pressurized test, gaps held off +27kv with 20 psi at 1/4" spacing. Decided to do a test shot. Completely blew out my charging supply and variac. Back pulse was large enough that it actually arced across the primary terminals of the hv charging transformer. Also fried my variac and tripped the breaker. On the plus side, my capacitor insulation works perfectly, the gaps seemed to fire fine, trigger at about 15psi. Bit of leaking in a couple switches, but not much of an issue at such low holdoff pressure. I may need to add more charging supply protection lol... 09-Apr-19 07:12 PM Ouch 09-Apr-19 09:07 PM Awesome science. Sucks in the variac... I may be able to loan you another or maybe we can find you one at the surplus place :) 09-Apr-19 09:07 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1888-FD2AC.jpg 09-Apr-19 09:07 PM Working on new valves on the SEM :) 09-Apr-19 09:30 PM I at least was able to capture this with my crappy phone camera. I had to slow it down to x0.125 speed on the computer and press play/pause as fast as I could to step through the video to capture the discharge. Looks like its a corona discharge. Spacing is 200mm, so not quite enough voltage to hit 200kV. The losses back through the charging supply are probably what killed the rest of the energy in the pulse. I'm going to have to build a copper sulfate divider so I can look at pulse width and rise time. I'm reasonably confident that I am achieving a faster pulse than anticipated, which makes pulse charging the second stage easier. At least everything else I wanted to verify checked out, its always the thing you never expect to fail lol. 09-Apr-19 09:30 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/First_Test_Shot_-_Corona_Discharge_200kV-0757D.jpg 09-Apr-19 09:30 PM @Conmega thanks for the offer lol, though I may want to run a bunch of tests to make sure I don't kill anymore supplies and really beef up my protection first. I just had some large ferrite chokes on the +hv charging line, which always worked fine for single and double cap tests, but I guess it wasn't even close to enough for the full 20 cap bank shot. 09-Apr-19 09:34 PM Hehe okie. You know the size of my variac if you need to borrow it lol 09-Apr-19 09:37 PM I've got one more 30kv Plastic Capacitor rectified transformer supply, but I really don't want to kill it. My upgrade supply is a TDK-Lambda Adjustable 40kV supply that can do 1kJ/s charging, but I'm definitely not putting that on until I get the protection in. I may want to put a small Pearson coil on the charging lines and monitor if there is any nasty back-pulse coming through. Probably want to use a big string of protection diodes with a much more beefy choke as well. 09-Apr-19 09:37 PM The other possible failure which would be worse is if I blew out a capacitor, which could cause the supply to short while trying to charge, though I definitely know a nasty pulse went back through the supply. 09-Apr-19 10:54 PM I need to come over to your place at some time to just see this stuff omg. 09-Apr-19 10:54 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1899-E8DA4.jpg 09-Apr-19 10:54 PM Also what is wrong with me... I've started bagging and labeling extra parts.. 09-Apr-19 10:54 PM I think it's time for bed lmao 10-Apr-19 12:48 PM Just submitted an order for a bunch of stuff for getting the charging supply up, as well as taking pulse measurements. Hopefully next week I can have everything made for a better isolated supply as well as seeing the pulse parameters. Since this is probably a faster than typical pulse for similar amateur builds, in addition to having low total stored energy, I most likely cannot do a regular distance breakdown measurement in air over such a long distance (like 200mm for 200kv) and will have to rely on the copper sulfate divider as well as fast current transformers for measurements. No more arcs except in the spark gaps! The tricky part will be setting the output switches to about 90% breakdown of the full voltage pulse. If the measurements next week show the rise time is fast enough, I can actually directly drive the load with the primary stage and operate the accelerator at lower beam power for now to start getting results with beam. 10-Apr-19 01:14 PM Would omething like a 3000A rogowski work for that? 10-Apr-19 01:14 PM Awesome! 10-Apr-19 01:14 PM I think I have 3000A and 4000A rogowskis somewhere. 10-Apr-19 01:14 PM re: pulse measurement 10-Apr-19 01:16 PM Actually yeah, I'm only expecting 1.2kA at most for this stage. If the second stage works, I will need to make my own to measure up to 30kA, but that's still quite a while away. 10-Apr-19 01:16 PM I've got 2 small 500 amp ones, which I can use for both thruster testing as well as looking at any back pulses to make sure my new charging resistor and chokes are suppressing it 10-Apr-19 01:17 PM I should dig up the rogowskis, they are currently doing anything 10-Apr-19 01:17 PM either it was 2x 1500A and one 3000A, or 2x 3000A and one 4000A one 10-Apr-19 01:19 PM I can also make my own pretty easy and use my Pearson coils to calibrate it. I've got x2 500A Pearson, not rogowskis. 10-Apr-19 01:19 PM Tbh, I really should have started testing at very low voltage and worked my way up with proper instrumentation, got a bit too anxious to try firing lol 10-Apr-19 01:34 PM :) I think we all do that from time to time 10-Apr-19 01:56 PM Wellll I am ending up with a third cryo compressor... What science can I do with all this cryo capability? hrmmm... 10-Apr-19 01:56 PM some very cool stuff 10-Apr-19 01:56 PM I could get to UHV easy peasy now I'm sure hah 10-Apr-19 01:56 PM Unfortunately this compressor isn't brandy new like the other but it only appears to have 8000 or less hours on it, so its not worn out either... 10-Apr-19 01:56 PM It also has a cryo head with it but NO HOSES AGAIN 10-Apr-19 01:56 PM GAH 10-Apr-19 01:56 PM but this is a SINGLE PHASE compressor, so less capacity I'm sure but oh man, I can run it off the outlet I have setup for the SEM if I wanted to 10-Apr-19 01:56 PM This surplus place I am going to will also have a billion 3 phase motors 10-Apr-19 01:56 PM So I could probably nab one for cheap and make a converter finally 10-Apr-19 02:00 PM you could play around with superconductor stuff 10-Apr-19 02:00 PM might even get down to type 1 SCs 10-Apr-19 02:00 PM @Conmega did you get it from the surplus place? 10-Apr-19 02:00 PM soo... build a sputtering system and start with josephson stuff 10-Apr-19 02:03 PM Oh man, boards arrived for my first thruster, and parts arrived for the second thruster! 10-Apr-19 02:03 PM I've successfully timed the offset of the thruster and accelerator projects so I always have something to work on lol. When parts are ordered for one, the other is ready for some stage of the next build phase 10-Apr-19 02:10 PM @Conmega or grab a VFD and use that for the 1phase --> 3phase 10-Apr-19 02:42 PM @Applied_Ion nope from HGR Inc out in Ohio 10-Apr-19 02:42 PM @rfs I don't think VFDs are good for running compressor motors with... 10-Apr-19 02:42 PM depends on the quality of the VFD 10-Apr-19 02:56 PM ^ 10-Apr-19 02:57 PM right, they do have some surplus VFDs there 10-Apr-19 02:57 PM I could see about one of those 10-Apr-19 02:57 PM I just discounted VFDs because of their inherent price 10-Apr-19 02:57 PM just give them a try, if the compressor sounds unhappy let it be 10-Apr-19 02:59 PM Sure, I'll just need to find one at HGR while I'm there for a reasonable amount lol 10-Apr-19 05:41 PM No pump or gate valve yet but it’s slowly coming together 10-Apr-19 05:41 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-1ADD7.jpg 10-Apr-19 07:06 PM So, I started troubleshooting the pulser. All the charging resistors checked out. I tried the variac and hv supply on my spare test cap. Works perfectly fine. I don't think I blew out the charging supply. This could be really bad news. The only thing left are the caps. If I blew any of those out I'm screwed lol. It's gonna take a while to test each set to see if any are shorted. 10-Apr-19 07:06 PM The only possible other thing is if there was surface tracking on the inside of a gap and it's causing the charging supply to short. Rather lose a gap than a cap. 10-Apr-19 07:06 PM Gotta say though, I'm really impressed with the Plastic Capacitor supply. It's taken an absolute beating, and still survived that nasty back arc. Really well built stuff. 10-Apr-19 10:29 PM @a_quiet_scientist Awesome!!! like my little baby chamber haha 10-Apr-19 10:29 PM uhggg that sucks, I hope your caps aren't shot 11-Apr-19 12:12 AM moin 11-Apr-19 12:15 AM Moin 11-Apr-19 12:15 AM Pulling an all nighter tonight to crash early today to get up early Friday for the drive out to Ohio 11-Apr-19 12:54 AM If you follow Carl Willis on Facebook he has another awesome post on X-ray spectroscopy of a plutonium sample 11-Apr-19 12:54 AM His ability to scrounge up plutonium with ease is incredible 11-Apr-19 01:21 AM oh wow 11-Apr-19 01:21 AM I don't have facebook on my phone, can you post a Screenshot? 11-Apr-19 01:21 AM I'love to see the Pu sample 11-Apr-19 01:23 AM PU 11-Apr-19 01:23 AM O_O 11-Apr-19 01:23 AM free Pu \o/ 11-Apr-19 01:26 AM Puh. 11-Apr-19 01:26 AM getting microgramms of the stuff is pretty easy 11-Apr-19 01:26 AM old sovjet smoke detectors used it, because there is no way mother russia uses americium 11-Apr-19 01:28 AM lol srsly? 11-Apr-19 01:28 AM no joking? 11-Apr-19 01:28 AM https://hackaday.com/2017/02/09/soviet-era-smoke-detector-torn-down-revealing-plutonium/ 11-Apr-19 01:28 AM it's on hackaday, so it must be true 11-Apr-19 01:31 AM https://carlwillis.wordpress.com/2017/02/07/analysis-of-soviet-smoke-detector-plutonium/amp/ 11-Apr-19 01:31 AM yeah 11-Apr-19 01:36 AM Things that are still on my must have list 11-Apr-19 01:48 AM (is it illegal) ^^' 11-Apr-19 01:48 AM to own i dunno 2 microgram of Pu 11-Apr-19 01:48 AM in germany 11-Apr-19 01:48 AM i've 'learned' that even operating a low energy device like a SEM with 50keV max is regulated in germany - 11-Apr-19 01:48 AM if it would be a large colour CRT television it would be ok though 11-Apr-19 01:48 AM right? 11-Apr-19 01:48 AM kinda sick imho 11-Apr-19 01:54 AM yeah, it's pretty restricted 11-Apr-19 01:54 AM heh maybe i should mod my CRT to become an "empfangsbereites geraet" 11-Apr-19 01:54 AM to pay extra gez? :D 11-Apr-19 01:54 AM i mean, i should mod my SEM 11-Apr-19 01:54 AM well i pay GEZ but don't use their "high quality" services 11-Apr-19 01:55 AM I wonder why 11-Apr-19 01:55 AM ehehehee 11-Apr-19 01:55 AM :D 11-Apr-19 01:55 AM but yeah, the law is not that obvious, some old things are still legal in spite of being above the "freigrenze", something like "Bestandsschutz" 11-Apr-19 01:56 AM yeah, it's like "Bestandsschutz" not like "Freibier" 11-Apr-19 01:56 AM :D 11-Apr-19 01:56 AM it's all a bit weird 11-Apr-19 01:56 AM rule of thumb is: If you don't hurt anyone the Behörde does not care 11-Apr-19 01:58 AM actually i pay GEZ three times 11-Apr-19 01:58 AM yeah, simply don't tell anyone about your SEM %) 11-Apr-19 01:58 AM one time for my flat, then for an small office space and another fee for my "hacker space" 11-Apr-19 01:59 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/34c649619e40488b81fe76e7daa0892f-9854B.jpg 11-Apr-19 01:59 AM pay for three times the quality 11-Apr-19 02:00 AM and iirc that's app 30-40 Euros per month 11-Apr-19 02:00 AM like netflix + spotify + amazon prime ... 11-Apr-19 02:00 AM per or in total? 11-Apr-19 02:00 AM in total 11-Apr-19 02:00 AM maybe more like 50? 11-Apr-19 02:00 AM the flat is "full rate" which is app 20 euro? 11-Apr-19 02:00 AM or more? hum 11-Apr-19 02:00 AM and "Betriebsstaetten" have reduced fees 11-Apr-19 02:01 AM hm, ok 11-Apr-19 02:02 AM never had a television 11-Apr-19 02:02 AM yeah, what for 11-Apr-19 02:02 AM yeah, maybe as a "cheap large display" but ... 11-Apr-19 02:02 AM i use a projector for comfy console gaming or movies 11-Apr-19 02:02 AM i stop cause it's off topic %) 11-Apr-19 02:06 AM sometimes on topic 11-Apr-19 02:06 AM xD 11-Apr-19 06:24 AM operating a störstrahler is actually only a problem if you have employees 11-Apr-19 08:41 AM depends on the dose rate 11-Apr-19 09:04 AM This is cursed and bad 11-Apr-19 09:04 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-13D76.jpg 11-Apr-19 09:04 AM Carl’s German made plutonium spinthariscope 11-Apr-19 09:04 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-7EB90.jpg 11-Apr-19 09:04 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-AA4CF.jpg 11-Apr-19 09:07 AM damn, nice 11-Apr-19 09:08 AM Next week I get to use the SEM ... SEM training day ^_^ 11-Apr-19 09:08 AM SEM alll the things 11-Apr-19 09:33 AM Why... why would you waste a piece of a synchrotron for a planter... 11-Apr-19 09:33 AM It's like physicists in the field don't actually do this stuff at home for fun apparently lol 11-Apr-19 09:34 AM no, the dose rate is completely irrelevant in the RöV 11-Apr-19 09:34 AM if you are only irradiating yourself as the owner of the company, that is absolutely fine 11-Apr-19 09:39 AM @sync that was a bad joke on the word "strahler" 11-Apr-19 09:43 AM but theehehe 11-Apr-19 09:43 AM jeez 11-Apr-19 02:18 PM wow SEM is regulated in Germany? 11-Apr-19 02:18 PM that's crazy 11-Apr-19 02:18 PM USA is pretty much, if you aren't paying taxes on business income, then you're being bad... or if you're doing dangerous business in a residential zoned area, then you're doing bad... otherwise pretty much everything is OK 11-Apr-19 02:21 PM Sem is regulated in most states as an x Ray device 11-Apr-19 02:30 PM yeah but that would be for manufacturers 11-Apr-19 02:30 PM right? 11-Apr-19 02:31 PM No end users as well 11-Apr-19 02:33 PM eh? 11-Apr-19 02:33 PM any hard info on that? 11-Apr-19 02:34 PM I'm more familiar with the laws in Washington than where you are, but I have gone through registration on multiple systems 11-Apr-19 02:35 PM looks like electron microscopes are exempt https://secure.sos.state.or.us/oard/viewSingleRule.action?ruleVrsnRsn=60023 11-Apr-19 02:35 PM unless I'm reading the wrong info 11-Apr-19 02:35 PM Does that mean any sem user at home needs to register? What about any other xray producing device? 11-Apr-19 02:35 PM or there's other laws 11-Apr-19 02:38 PM Where's documentation on the regulation of xray stuff? 11-Apr-19 02:38 PM Because my idiot self was able to buy one for $50 from the state lol 11-Apr-19 02:39 PM For people building fusors, no one ever registers for personal use, so I'm wondering what is considered regulated 11-Apr-19 02:39 PM in germany a fusor is technically illegal 11-Apr-19 02:39 PM well not only technically 11-Apr-19 02:39 PM it's just that stuff like that is never enforced unless you hurt someone 11-Apr-19 02:41 PM I'm interested in regards to my accelerator. That will certainly produce xrays as a byproduct (or intentionally depending on the configuration) 11-Apr-19 02:42 PM http://i.imgur.com/ABhGrUp.jpg 11-Apr-19 02:42 PM (not legal advice and applies to Washington) 11-Apr-19 02:42 PM As the law is written, every SEM needs to be rigistered. They are however exempt from ceartian requirements that other instruments are. 11-Apr-19 02:42 PM I'm practice though, you don't/can't register unless you have a business liscense at your address. 11-Apr-19 02:42 PM Additionally enforcement is spotty. I have had scope be fully surveyed and other ones forgotten about for years. 11-Apr-19 02:42 PM I have had the department or radiation health and safety come look at a fusor before, and because the thing was shielded they were just kinda ok with it. Yeah it produces a massive amount of x rays but meh isn't quite what I was expecting. A sem in that same lab is registered though and got surveyed, the fusor did not 11-Apr-19 02:42 PM It's definitely state by state though, so I couldn't really speak to anyone else 11-Apr-19 02:52 PM I'm sure NY state is pretty strict... 11-Apr-19 02:52 PM Though given the xray pulse would be less than 1us single shot, it's not quite the same as a fusor or sem running continuously, though higher intensity for that short duration. 11-Apr-19 02:57 PM @Treehouseman sounds like a setup 11-Apr-19 03:06 PM Well it was like 6+ months ago and no one has come around asking about it :P 11-Apr-19 03:06 PM Plus the thing is pretty weaksauce, I haven't even gotten a third arm yet 11-Apr-19 03:45 PM @AdamMcCombs I did not realize I need/should register my SEM... 11-Apr-19 04:50 PM If you aren't a business don't 11-Apr-19 04:50 PM I think 11-Apr-19 04:50 PM I wasn't able to when I tried 11-Apr-19 04:54 PM wait wat registering an SEM lmao hate regulations 11-Apr-19 04:56 PM It's for x ray 11-Apr-19 04:58 PM @Treehouseman bought a dental Xray.... I mean... regulation seems super lax 11-Apr-19 05:02 PM I mean the cancer will take me soon enough, it's a self solving issue 11-Apr-19 07:32 PM Is it possible to use fluorocarbons like CF4 in a home lab? 11-Apr-19 07:44 PM Hm, I see it requires cryogenic storage.... 11-Apr-19 08:43 PM I mean you need flurocarbons for reactive ion Etching so I hope so but a ton of them are super expensive... 11-Apr-19 08:43 PM The only storage I know for them is standard bottles... Like refridgerents... Which are generally also flurocarbons. 11-Apr-19 08:43 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1904-F6740.jpg 11-Apr-19 08:43 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1901-BFF66.jpg 11-Apr-19 08:43 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1902-51C10.jpg 11-Apr-19 08:43 PM New valvesss 11-Apr-19 08:43 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1898-5BAD3.jpg 11-Apr-19 08:43 PM Vs the old stuff 11-Apr-19 09:01 PM @Conmega , I'm getting outbid on those plasma prep machines 11-Apr-19 09:04 PM Uhg really? What are they to? 11-Apr-19 09:05 PM $430 11-Apr-19 09:05 PM Not sure if I should go higher 11-Apr-19 09:10 PM Hrm... @AdamMcCombs seemed to value them higher... I could go up to like 250 I guess.. 11-Apr-19 09:10 PM Too late, auction over 11-Apr-19 09:10 PM After taxes and fees it would have come to $500... too rich for my blood since one of them was missing a pyrex chamber piece that would cost another $500 to replace. 12-Apr-19 01:55 AM Yeah I would have gone a bit higher but not much. Fully functional worth at least 1k 12-Apr-19 01:55 AM "worth" 12-Apr-19 01:55 AM SPI sells them a supper big markup, all of the sample prep tools are that way though 12-Apr-19 01:55 AM It's really unfortunate, but honestly its easier to sell a 20k tool to a university than it is to sell a 5k one. 12-Apr-19 01:55 AM So tools like that get supper over priced for what they are. 12-Apr-19 01:55 AM The valuation on prep tools like that is kinda odd in general. For a few hundred bucks you can build your own system that does the same thing as one of those though 12-Apr-19 08:13 AM the lab tax 12-Apr-19 08:19 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1908-C3BC6.jpg 12-Apr-19 08:19 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1907-7B886.jpg 12-Apr-19 08:19 AM I'm in heaven 12-Apr-19 08:19 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1912-D7845.jpg 12-Apr-19 08:19 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1913-D9FD1.jpg 12-Apr-19 08:19 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1911-26C75.jpg 12-Apr-19 08:19 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1914-63A52.jpg 12-Apr-19 09:32 AM HGR is where I bought my jig borer that I still have to ship, was going to try to schedule something soon 12-Apr-19 09:32 AM @Conmega so you're visiting Cleveland, eh? 12-Apr-19 09:32 AM Wanna pickup my borer and freight it to me? :) 12-Apr-19 09:32 AM Second Saturday of every month they are open iirc 12-Apr-19 09:32 AM I am having a buddy who lives in CLE who viewed it to nab it, bring it home, and ship it out 12-Apr-19 09:32 AM They don't allow outside shippers, so if you buy something big, bring your own truck and they will load up for free, their contracted shipper is a lil pricey 12-Apr-19 12:22 PM but yeah, lmk next time you are going there in case I have some equipment that needs some picking 12-Apr-19 04:27 PM Hah yes I am, its an 8 hour trip for me though, I am coming from NY state 12-Apr-19 04:27 PM I don't have a truck but an SUV and an exclosed trailer, can't really go over 3000~lbs 13-Apr-19 12:37 AM are there those shops in europe? 13-Apr-19 02:52 AM i mean such shops alike 13-Apr-19 11:25 AM @Conmega good to know.. I am nearing the completeness of my larger machines, so it would simply be smaller items.. I havent really looked at them for anything too small though 13-Apr-19 11:25 AM I have yet to be there myself.. but my buddy who lives in CLE told me about it and checked out the machine I got for me 13-Apr-19 11:25 AM once I move back to Columbus I will likely be checking them out more often 13-Apr-19 11:25 AM surface and tool grinder is sorta on my list still 13-Apr-19 11:25 AM also ID and OD 13-Apr-19 01:59 PM They have atleast 40 surface grinders and surface plates at any given time like lmao 13-Apr-19 01:59 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_2051-821AD.jpg 13-Apr-19 01:59 PM I'm now able to dual weild SEMs :) 13-Apr-19 02:53 PM @Conmega did you get a second sem? 13-Apr-19 03:02 PM Maybeeee 13-Apr-19 03:02 PM :) 13-Apr-19 03:02 PM I mean this thing is pretty tired looking, missing all panels and yea... probably needs a lot of work 13-Apr-19 03:02 PM going to be a side project, I mean I'll just have a small Electron Microscopy lab going in the basement I guess heh... 13-Apr-19 03:08 PM Nice! 13-Apr-19 07:36 PM was that from them? did they even know what they had? 13-Apr-19 07:42 PM The surplus place? 13-Apr-19 07:42 PM yes, but they never care what they have 13-Apr-19 07:42 PM just care what people are willing to pay for it 13-Apr-19 07:42 PM right 13-Apr-19 07:42 PM and how quickly they can move it 13-Apr-19 07:42 PM they do specialize in certain equipment 13-Apr-19 07:42 PM they know machinery better 13-Apr-19 07:43 PM Sure, but same difference 13-Apr-19 07:44 PM once I move back to Ohio I'll check them out in person a bit more 13-Apr-19 08:37 PM This is normal desk right? 13-Apr-19 08:37 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-F4256.jpg 13-Apr-19 08:37 PM Yes 13-Apr-19 08:37 PM Mine looks almost exactly the same 13-Apr-19 08:37 PM Did some excavation and now my keyboard is only 1/3 blocked 15-Apr-19 04:57 PM Oh dear, just walked past a lab (not a lab I use fortunately) and the handwritten sign stuck to the door is not a good sign : Do not enter due to HF leak in tool. Have fun cleaning that up. 15-Apr-19 04:58 PM That's... What? 15-Apr-19 05:10 PM They’ve evacuated and locked out that room as a precaution, full chemical cover suits for cleanup 15-Apr-19 05:10 PM Etching / wet processing tank I think 15-Apr-19 05:10 PM Have fun cleaning that up was my comment above, the sign doesn’t say that 15-Apr-19 05:22 PM HF scares me 15-Apr-19 06:51 PM The key is to make it HFHV, stuff involving high frequency high voltage is always a fun time 15-Apr-19 09:14 PM @Treehouseman HF as in hydrofluoric acid 15-Apr-19 09:57 PM As in death 15-Apr-19 09:57 PM While hurting the entire time 16-Apr-19 03:07 AM I know :P 16-Apr-19 03:30 AM HF actually does not hurt most of the time while it kills you 16-Apr-19 07:14 AM I’ve never figured out what this is for sure but it does kind of remind me of a SEM chamber sort of 16-Apr-19 07:14 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-667C1.jpg 16-Apr-19 07:14 AM It’s a beautiful machined single block of aluminium about 250mm across 16-Apr-19 09:19 AM nice 16-Apr-19 09:19 AM does anyone know some cheap RGA? 16-Apr-19 04:54 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_2071-C17F9.jpg 16-Apr-19 04:54 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0000_BURST20190416190824143-CD698.jpg 16-Apr-19 04:54 PM Vacuum pump back in action. 16-Apr-19 05:38 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_2072-8BF25.jpg 16-Apr-19 05:43 PM Nice 16-Apr-19 05:43 PM Time to figure alignment out 17-Apr-19 04:56 PM Joined the server. 18-Apr-19 02:06 AM I wish international McMaster-Carr was a thing. I mean Digi-Key manages it fine so you can too 18-Apr-19 09:33 AM This is no McMaster-Carr, but they have a decent selection and re in UK https://www.pts-uk.com/ 18-Apr-19 09:33 AM More of a nuts and bolts kinda store 18-Apr-19 10:33 AM Arrow > digikey as long as they have it in stock 18-Apr-19 12:54 PM mouser > everything 18-Apr-19 12:59 PM Does mouser have free overnight shipping on a $1 order? 18-Apr-19 01:26 PM @Treehouseman digikey will if you send a check or money order to them https://www.digikey.com/en/terms-and-conditions "* When a check or money order accompanies your order, Digi-Key pays all shipping and insurance (our choice for method of shipping) to all addresses in the U.S. and Canada." 18-Apr-19 01:26 PM @Treehouseman err, sorry, not free overnight 18-Apr-19 01:26 PM oop 18-Apr-19 01:26 PM oops 18-Apr-19 01:32 PM no, but mouser ships to germany :P 18-Apr-19 01:35 PM Arrow doesn't? 18-Apr-19 01:35 PM AFAIK it's free overnight for international for most countries 18-Apr-19 01:35 PM One of their distribution centers is in the Netherlands 18-Apr-19 02:46 PM hm, ok 18-Apr-19 02:46 PM gotta look into that, not sure if they do 18-Apr-19 02:56 PM just an fyi, their site sucks as far as searching, if you know a part you want, search it directly with the manufacturer part number and you should find it 18-Apr-19 02:56 PM I've had quite a few things not show up in the parametric catetory searches, but when I pull it up via direct part number in the search bar it takes me right to it 18-Apr-19 02:56 PM but it's really nice to order something by like 12PM EST, and have it on my porch by 10AM EST the next morning 18-Apr-19 02:56 PM And they'd literally do it if I ordered a single 10 cent resistor 18-Apr-19 02:56 PM for just the 10 cents plus tax 18-Apr-19 02:56 PM They've lost SO much money on my orders lol 18-Apr-19 06:35 PM Arrow’s free international (worldwide?) on any small order is nice 18-Apr-19 06:35 PM Haha in other words you can just search for it on Digikey and put the part number into Arrow? 18-Apr-19 06:35 PM Frankly I think website usability, search usability and the amount of things they stock is the reason I use Digikey first. Free international shipping (to here at least) on orders over $50 and a reliable 4-5 days to get it 18-Apr-19 07:01 PM This week's project 18-Apr-19 07:01 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190418_185615-5B979.jpg 18-Apr-19 07:04 PM garage sem yaaay :D 18-Apr-19 07:06 PM This is scope 1 of 4 going in here 18-Apr-19 07:27 PM yeah, digikey has better stock generally but if you're just needing that one resistor you don't have arrow is beautiful 18-Apr-19 07:27 PM used to put off projects because I wasn't going to order $2-3 worth of parts and then pay $8+ of shipping 18-Apr-19 07:27 PM now, if I need a single part, or smoke a part, I'm just instantly ordering it 18-Apr-19 07:27 PM Like that time I needed to order a single 180k ohm resistor to fix a huntron tracker 2000, I put that off for months and months before I felt I could justify the shipping on a digikey order, but if that was needed today? new arrow order for a qty of 2 just in case, it'll cost me <$1 and be here the next morning 18-Apr-19 07:27 PM If I hadn't put it off for so long I'm pretty sure I could have gotten an extra few hundred dollars out of it when I sold it 19-Apr-19 12:18 AM Getting it the next day? I wish that was really a thing here 19-Apr-19 03:52 AM Arrows parametric search sucks. In terms of search usability Digikey > Mouser > TME > Farnell > Arrow 19-Apr-19 03:59 AM Arrow used to have free international shipping at the 20usd mark. But I think that promotion ended. 19-Apr-19 03:59 AM The customs VAT limit is 22.44eur here 19-Apr-19 03:59 AM so if I ordered 22eur (no discounts) worth of stuff from arrow I got it fast and did not have to deal with customs 19-Apr-19 08:45 AM moin 19-Apr-19 08:45 AM Moin ^^ 19-Apr-19 08:45 AM moin and greetings from the stuttgart airport 19-Apr-19 08:46 AM yay 19-Apr-19 08:46 AM what are your plans? 19-Apr-19 08:47 AM well my plan was to get into a bus 20 mins ago to drive home 19-Apr-19 08:47 AM bus company says no. 19-Apr-19 08:47 AM ok y not 19-Apr-19 08:47 AM kinda easteregg 19-Apr-19 08:47 AM you've got a no-egg 19-Apr-19 08:47 AM the kind of surprises everyone likes 19-Apr-19 08:47 AM yeah 19-Apr-19 08:47 AM at least the weather is nice I guess 19-Apr-19 08:48 AM sunny 19-Apr-19 08:48 AM but not too warm with a nice breeze 19-Apr-19 08:48 AM my plan is building a small stm32 board for my hornets 19-Apr-19 08:49 AM cool! 19-Apr-19 08:49 AM but... isn't the stm a bit op? ^^ 19-Apr-19 08:49 AM currently i'm using a pitaya, what's kinda overkill, i guess 19-Apr-19 08:49 AM well 19-Apr-19 08:49 AM xD 19-Apr-19 08:49 AM it's cheap, i mean, what else should i use? 19-Apr-19 08:49 AM stm32f10x costs 50 cent or something? 19-Apr-19 08:49 AM even a complete board like a "blue pill" is about 1.50 19-Apr-19 08:50 AM dunno, my first try would be something like an atmega8 19-Apr-19 08:50 AM oh, ok 19-Apr-19 08:50 AM ok, but i want USB 19-Apr-19 08:50 AM yea you can't beat that 19-Apr-19 08:50 AM or ethernet 19-Apr-19 08:50 AM but USB is ok for that purpose 19-Apr-19 08:52 AM I agree with you, didn't think of anything but a display 19-Apr-19 08:52 AM but you're right, i should add a cheap oled display 19-Apr-19 08:52 AM maybe talk to @niklas , he already did something like that 19-Apr-19 08:53 AM i have such cheap oled displays with SPI 19-Apr-19 08:53 AM i guess they are enough for me 19-Apr-19 08:53 AM only the cheapest is good for me 19-Apr-19 08:58 AM as long is it works why not ^^ 19-Apr-19 08:58 AM damn it 19-Apr-19 08:58 AM my bus is here but I don't think it's got wifi 19-Apr-19 08:58 AM and my phone is almost dead >.< 19-Apr-19 09:11 AM ok! 19-Apr-19 09:39 AM @N00N There is this Finnish saying "Halvin, eli paras." Which translates to something like "The cheapest,also known as The best." 19-Apr-19 09:40 AM finnish it! 19-Apr-19 09:40 AM killer combo finnish move 19-Apr-19 09:40 AM https://pics.me.me/the-ill-assault-is-a-wonderful-tank-apologize-to-the-1765776.png 19-Apr-19 10:58 AM unfortuantly I have no IGM 400 kits left 19-Apr-19 10:58 AM but feel free to order some pcbs: https://github.com/NiklasFauth/IGM-400 19-Apr-19 10:58 AM should be <$10 for both pcbs on jlcpcb.com 19-Apr-19 11:27 AM ah ok 19-Apr-19 11:27 AM want to use a stm32f103 19-Apr-19 11:27 AM but similar display 19-Apr-19 11:38 AM those family meetings - now im drunk i guess 19-Apr-19 11:38 AM jk i'm always drunk 19-Apr-19 11:44 AM prost! 19-Apr-19 12:41 PM Joined the server. 19-Apr-19 10:18 PM wee, I helped the guy I work part-time for today replacing his air compressor and got some cash, some 1" ID tubing, and a nitrogen tank regulator in exchange 19-Apr-19 11:19 PM @niklas got a photo of the assembled IGM400 board? 19-Apr-19 11:19 PM This giant 6-part History of Photoresist is interesting https://www.polymersolutionsfe.com/single-post/2018/02/26/60-Years-of-Photoresist-Materials-Part-3-The-Age-of-NovolakDNQ 21-Apr-19 04:56 AM The AnaLog website has a wealth of interesting stuff on well logging hardware - building electronics for rugged environments at high temperature, scintillation detectors, neutron detectors, high voltage regulation and all that good stuff http://logwell.com 21-Apr-19 09:34 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_2128-B38A2.jpg 21-Apr-19 09:34 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_2129-F81DE.jpg 21-Apr-19 11:18 PM Wow, a twitter spam bot appears to have actually provided a reputable seller for exactly what I wanted 21-Apr-19 11:18 PM https://twitter.com/hmndyh/status/1120195509388488704?s=21 22-Apr-19 01:54 AM Moin! 22-Apr-19 01:54 AM @a_quiet_scientist is that... slotin?! 22-Apr-19 05:12 AM You haven’t seen this before then 22-Apr-19 05:13 AM @Conmega comfy chair! 22-Apr-19 05:16 AM @GigaSquirrel Do a google image search for デーモンコア 22-Apr-19 05:16 AM 20 sieverts of memes right in your face 22-Apr-19 05:16 AM @Conmega I like the chair 22-Apr-19 05:18 AM omg 22-Apr-19 05:19 AM And no, I don’t know why the demon core is a meme 22-Apr-19 05:19 AM this is so wrong :D 22-Apr-19 05:19 AM I know 22-Apr-19 05:19 AM I love it 22-Apr-19 05:25 AM “they gathered eight rods painstakingly crafted out of plutonium, and positioned them side-by-side on a table to photograph how nice they looked” https://www.sciencemag.org/news/2017/06/near-disaster-federal-nuclear-weapons-laboratory-takes-hidden-toll-america-s-arsenal 22-Apr-19 05:25 AM You would think this would be deadly serious at LANL after melting somebody the last 3 times it has happened. 22-Apr-19 05:26 AM @a_quiet_scientist It is a cool story, with a moral about hubris or something. But not a well known story in the US. As we say, "it just goes to show". 22-Apr-19 05:58 AM WRT the current situation at LANL, what I'm really puzzled about is (aside from tedious details about avoiding various accidents), how could management fail to decide to create the impression of a strong response to their operation being shut down. It seems they have leveraged their monopoly into a license to be ineffective. 22-Apr-19 08:09 AM Just finished reading all six articles. Really shocking and quite disturbing how many accidents occur on a regular basis involving nuclear contamination, chemicals, explosions, etc 22-Apr-19 08:11 AM But how else are you supposed to learn 22-Apr-19 08:12 AM I was recently contacted by a recruiter earlier this year from Los Alamos to interview for a position engineering detonators for nuclear weapons for their nuclear stockpile stewardship program. Besides declining from the fact that I have no desire to contribute to weapons development or use of pulsed power for weapons, feels like I dodged some nasty bullets as well lol. 22-Apr-19 12:20 PM My feel is that while it is essential to have people whose job is specifically safety, once you go and put those people in their own department in a bureaucratic structure, it is almost inevitable that the safety people come to be seen as an obstacle rather than a resource. This is a difficult circle to square even for competent management. It is also plausible that they might have in some sense devoted too much resource to avoiding criticality accidents (which are sensational), and as consequence evolved a structure of complex restrictive work rules which eventually lead the whole safety system to be held in contempt. The people who were stacking up the plutonium ingots didn't want to die, they just weren't thinking. And perhaps the whole system was overly reliant on rules such as who was allowed to use which glovebox which did indeed avoid accidents, but the very absence of those accidents led to a perception that the rules were unnecessary. 22-Apr-19 12:25 PM A lot of the articles goes into the connection between lack of penalties, massive profits and rewards, and continuous repeated instances of safety negligence. Not all the issues are related to nuclear - a lot of chemical and explosion injuries too. 22-Apr-19 12:25 PM All in all, despite making historic advances in physics, these facilities that do mainly weapons still seem like sketchy places to work lol 22-Apr-19 12:53 PM Yes, I am not at all surprised that there are many other safety problems. I was speculating that an over emphasis on the extra-special unusual safety problems might be part of what caused the evolution of a dysfunctional safety culture at LANL. Re. insufficient penalties, I am unsure of what to think about the proper role of government safety regulations in avoiding major disasters vs. ordinary accidents (sometimes fatal). If there are too many accidents where people got hurt, then that is an occupational health and safety issue, and fines could help if they are big enough. With actual blow-up-the-plant disasters, management doesn't want those, and I don't think outside regulators are sufficiently informed about the unusual systemic problems to help much there. Really I would put criticality accidents closer to the group of ordinary workplace accidents rather than catastrophes. The cleanup can be more of a mess, but usually only one or two people get killed. I'm sure that at LANL way more people get hurt by machinery than nuclear stuff, and even more than those get hurt driving to/from work. 22-Apr-19 02:57 PM I am thinking I will be getting my first hand held gieger counter here soon 22-Apr-19 02:57 PM @GigaSquirrel opinions on this? 22-Apr-19 02:57 PM https://www.ebay.com/itm/Ludlum-Measurement-Survey-Meter-Geiger-Counter-Model-2-Alpha-Beta-Gamma-Sensor/143176431641 22-Apr-19 02:57 PM Helps if I copy the right link. 22-Apr-19 02:57 PM I have a friend with this setup just in nicer shape. He says the 44-7 probe is a nice sensitive probe. 22-Apr-19 02:58 PM yeah, ludlums are great 22-Apr-19 02:58 PM maybe ask the seller for a pic of the battery compartment before buying 22-Apr-19 02:58 PM the detector on the other hand 22-Apr-19 02:58 PM it is a nice detector in bad condition 22-Apr-19 02:58 PM you'll have to replace that some time soon 22-Apr-19 02:58 PM I'm not sure about the metal covering the mica, but it might be Be 22-Apr-19 03:01 PM https://ludlums.com/products/all-products/product/model-44-7 22-Apr-19 03:01 PM Detector Type End window, halogen-quenched G-M 22-Apr-19 03:02 PM I'm just not sure what's covering the mica 22-Apr-19 03:02 PM The film/dirt that looks eh? 22-Apr-19 03:03 PM aye 22-Apr-19 03:03 PM https://www.lndinc.com/products/geiger-mueller-tubes/723/ 22-Apr-19 03:03 PM I was wondering if that was just dirt. My friend's didn't appear to really have a coating, it was just clean and shiny 22-Apr-19 03:03 PM but mica is transparentish 22-Apr-19 03:03 PM can I try to clean the end of that detector with anything like alcohol and a q-tip if I get it? 22-Apr-19 03:04 PM no 22-Apr-19 03:04 PM do not ever touch that 22-Apr-19 03:04 PM ah... ok. 22-Apr-19 03:04 PM Also this is something fun looking I'd think you'd appreciate 22-Apr-19 03:04 PM https://www.ebay.com/itm/Ludlum-43-1-Alpha-Detector-Scintillator-Radiation-Probe/293042822934 22-Apr-19 03:04 PM that's extremly thin, any amount of pressure will break it 22-Apr-19 03:04 PM oh damn 22-Apr-19 03:04 PM I know that detector, but I've never seen anything from ludlum that was that old 22-Apr-19 03:04 PM https://electrosparkles.com/wp-content/uploads/2018/06/GEIGTUBEFRONT4.jpg That's what mica usually looks like 22-Apr-19 03:06 PM Really? hrm. ok 22-Apr-19 03:06 PM I would think its a thin glass but not so thin, I mean clearly dirt and stuff has touched that thing, my friend who has one didn't make it sound that fragile. 22-Apr-19 03:06 PM figured a qtip wouldn't break it with very light to no pressure and just a spinning motion, but what do I know. 22-Apr-19 03:06 PM I'll keep an eye out for one in better shape 22-Apr-19 03:06 PM its just the better shape ones are generally uh 22-Apr-19 03:06 PM https://www.ebay.com/itm/Ludlum-3-w-44-7-GM-End-Window-Geiger-Radiation-Survey-Meter-Alpha-Beta-Gamma/254203314770 22-Apr-19 03:06 PM spensive 22-Apr-19 03:08 PM yep 22-Apr-19 03:08 PM I'd buy that offer you posted and try to get as many detectors for it as possible 22-Apr-19 03:10 PM hrm ok 22-Apr-19 03:10 PM https://www.ebay.com/itm/Ludlum-44-7-End-Window-Geiger-Detector-Probe-Alpha-Beta-Gamma/254203314784 22-Apr-19 03:10 PM There are more 44-7s out there 22-Apr-19 03:10 PM and I can of-course get different probe ends 22-Apr-19 03:11 PM maybe look for the 44-9, similar detector but usually a bit cheaper due do higher numbers in production 22-Apr-19 03:11 PM I am just less knowledgable about the other probe ends, my friend just said the 44-7 is a great sensitive detector end for alpha/beta/gamma 22-Apr-19 03:11 PM Hrm ok 22-Apr-19 03:12 PM get all the detectors, there's a use case for everything 22-Apr-19 03:13 PM Yea I've noticed... its crazy how many there are 22-Apr-19 03:13 PM I've got a tungsten shielded end window GM for alpha / beta stuff, a NaI scintillator for low energy gamma and a plastic scintillator for higher energy gamma & fast neutrons 22-Apr-19 03:13 PM I also need to poke at that little gieger tube I got in that weird RMS box 22-Apr-19 03:13 PM https://www.lndinc.com/products/geiger-mueller-tubes/71210/ 22-Apr-19 03:13 PM it has one of these 22-Apr-19 03:14 PM oh, sweet 22-Apr-19 03:14 PM it was 10 bucks for the entire like 70lbs wall mounted box lol 22-Apr-19 03:14 PM energy compensated means it only sees gamma but is very accurate in telling you the actual dose rate 22-Apr-19 03:14 PM so yea... 10 bucks for a gieger tube, and some ciruitry to make it network connected and has a serial port on it.... 22-Apr-19 03:14 PM cool ok 22-Apr-19 03:14 PM I gotta power that box up and poke at the serial port 22-Apr-19 03:14 PM The network thing on it has no "open ports" it may just be spewing stuff over a port, not actually take anything in. 22-Apr-19 03:14 PM Hopefully the serial port has some configuration or something. 22-Apr-19 03:14 PM Not sure what I'll do with the detector unless I take the PCB out and hack it to be some portable thing. 22-Apr-19 03:21 PM build a dosimeter with it! 22-Apr-19 03:21 PM Maybe I'll mount it in my car somewhere lmao, just have a screen with the readings so whereever I'm driving I can see if anything picks up. 22-Apr-19 03:21 PM Hm.. the PCB in there is kinda large, and currently takes like 48V input I think? 22-Apr-19 03:21 PM leme get a photo 22-Apr-19 03:21 PM That would be a cool idea though considering the tube itself is fairly small 22-Apr-19 03:21 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_2039-A5223.jpg 22-Apr-19 03:21 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_2083-9006F.jpg 22-Apr-19 03:21 PM Oh also a photo of my friend's Ludlum setup 22-Apr-19 03:21 PM and his CD lol 22-Apr-19 03:23 PM just give it its desired ~500V and count the pulses 22-Apr-19 03:23 PM that thing above the GM tube also looks like a GM... 22-Apr-19 03:23 PM Yea I know they just have a little voltage multiplier and that regulator tube next to it 22-Apr-19 03:23 PM I believe its just a HV regulator 22-Apr-19 03:23 PM not another GM 22-Apr-19 03:23 PM Part number is there on the silkscreen though 22-Apr-19 03:24 PM oh, lol 22-Apr-19 03:24 PM that's a very... antique way to do it 22-Apr-19 03:24 PM its not like a... vacuum tube like you think 22-Apr-19 03:24 PM its like a ballast or something like that 22-Apr-19 03:24 PM they have a little voltage multiplier on the back and some other stuff going on 22-Apr-19 03:24 PM I don't have the thing open atm, that was a photo I had from when we opened a friend's 22-Apr-19 03:25 PM from your description it sonds like a voltage regulator tube 22-Apr-19 03:25 PM It only has 2 pins on it 22-Apr-19 03:25 PM https://en.wikipedia.org/wiki/Voltage-regulator_tube 22-Apr-19 03:25 PM And that shielding thats held down 22-Apr-19 03:25 PM oh hrm maybe it is then lmao 22-Apr-19 03:25 PM I dunno, I'll kinda reverse engineering whats going on with that thing here soon I guess. 22-Apr-19 03:25 PM I'll likely just wire it up straight first in the box with everything then hook to the serial port first before pulling it out and powering the unit by itself 22-Apr-19 03:25 PM the box is a radiation monitoring box, has tamper devices, 4 camera little capture device, the geiger box, a network switch, and a mains to 12/24/48v powersupply/ups I think? 22-Apr-19 03:27 PM lol 22-Apr-19 03:28 PM it was a project by the government, looking it up it appears they made about 160 of them to monitor.... sites... 22-Apr-19 03:28 PM we checked the boxes, none of them were really detectably hot or anything 22-Apr-19 03:29 PM detectable hot and contamination are two very different things 22-Apr-19 03:29 PM contamination is stuff like 0.01 Bq/cm² 22-Apr-19 03:30 PM Hrm... well we didn't have a really good detector checking anything on it... Maybe when I power up the little sensitive gamma detector it'll be going off lmao 22-Apr-19 03:30 PM My friend just checked them with one of those stupid little amazon plastic box things 22-Apr-19 03:31 PM its just a ton of aluminum and PCBs and such 22-Apr-19 03:32 PM yeah 22-Apr-19 03:32 PM please post more photos tomorrow, gotta go to sleep now 22-Apr-19 03:32 PM good night ^^ 22-Apr-19 03:33 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1940-EDB73.jpg 22-Apr-19 03:33 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1939-BD48E.jpg 22-Apr-19 03:33 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1936-40A4D.jpg 22-Apr-19 03:33 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1941-5D11E.jpg 22-Apr-19 03:33 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1945-164DB.jpg 22-Apr-19 03:33 PM Okie good night! and here are some more general photos of the thing this was in. 22-Apr-19 03:33 PM I'll poke at it tonight sometime 22-Apr-19 03:35 PM Let me know when you start 22-Apr-19 03:53 PM That thing above the GM tube does remind me of a Corotron regulator tube. But those things are dinosaur obsolete technology 22-Apr-19 03:58 PM yea I dunno why it would be there, I'll figure it out 22-Apr-19 08:17 PM Whoa that backplane connector 22-Apr-19 09:11 PM I like the cabinet and the beautiful neat DIN rail terminal block wiring 22-Apr-19 11:46 PM ahh, 8 o clock maths lecture 22-Apr-19 11:46 PM I almost missed this feeling 22-Apr-19 11:46 PM @Conmega looks like the thing was made for way more detectors and most have been taken out 22-Apr-19 11:46 PM all those male bnc connectors 23-Apr-19 12:11 AM Uh no those BNCs are for cameras :P 23-Apr-19 12:11 AM all those BNCs are very clearly labeled, but its a bad photo 23-Apr-19 12:11 AM along with all those other connections 23-Apr-19 12:16 AM naw, ok 23-Apr-19 12:16 AM what were the cameras looking at? 23-Apr-19 12:16 AM in other words: Why do they use male BNCs instead of female 23-Apr-19 12:16 AM lol, one hour into the lecture and the prof finally figured out how to turn on the light 23-Apr-19 01:52 AM https://www.eevblog.com/forum/projects/has-anybody-built-their-own-mass-spectrometer-before/ 23-Apr-19 01:52 AM "I like KF fittings and used them in the higher pressure sections of my MS. It looks like this will be a lost bit of history, can't find anything on-line, but I believe that KF fittings were derived from the dairy industry. If you lookup "milk line fittings" they look familiar. The story I remember is that Nor-Cal (now part of Pfeiffer Vacuum Technology AG) was originally in the dairy equipment business. They don't mention that on their Web site but they do say that they worked with Lawrence Livermore Laboratory to design standardized vacuum fittings." 23-Apr-19 03:49 AM yeah, they are basically the same thing 23-Apr-19 05:06 AM Depends what you mean by mass spectrometer 23-Apr-19 05:06 AM Quadrupole filter? 23-Apr-19 05:06 AM Or time of flight ? 23-Apr-19 05:06 AM Our research mass spectrometers (including both QMF and TOF parts) are a combination of different stuff - CF and KF and ISO and bits of Bruker MALDI systems being chucked out by the rich biologists, and sometimes just O-rings and Perspex plates and Hysol 23-Apr-19 05:06 AM The stages are at different vacuum levels so by the time you get to the end detector it’s all real stainless and conflat 23-Apr-19 05:43 AM We use the 6146 valve pair, basically the Anderson group university of Utah design, as a rugged general building block for ~1MHz high voltage 23-Apr-19 05:43 AM https://chem.utah.edu/_documents/anderson_research_group/simplified%20RF%20RSI.pdf 23-Apr-19 05:43 AM https://chem.utah.edu/directory/anderson/research-group/rfstuff.php 23-Apr-19 05:43 AM This paper is a nice open source driver for electrostatic Bradbury Nielsen gates 23-Apr-19 05:43 AM https://par.nsf.gov/servlets/purl/10045946 23-Apr-19 05:55 AM This amplifier has a bit of pileup when used with a micro channel plate detector, it’s no Amptek A250 but it’s much cheaper and does the job. https://github.com/lukeweston/MCPAmplifier 23-Apr-19 06:26 AM Could someone help me design a simple flip flop circuit? It’s late and I’m dumb and uncaffeinated 23-Apr-19 06:26 AM Input A has a rising edge and a little later input B has a rising edge. Output C turns on immediately at this time of the B edge. Input B has another rising edge later which immediately turns off output C. If output C is low then a rising edge on input B will not turn the output high if it is not also preceded by an input A rising edge. If C is high and a B edge is received with no previous A edge then C immediately turns off. If C is high and an A edge is received followed by a B edge then it remains high. 23-Apr-19 10:56 AM I've seen the fittings used for the milk industry and yes they look very similar and are practically even compatible. 23-Apr-19 10:56 AM The funnier thing is I've found HV equipment with the SAME shape! Like with the KF fitting style but with that little round indent in it all the way around. 23-Apr-19 10:56 AM So yea... Weird history there. 23-Apr-19 11:56 AM Also I believe I have found our cheap etching gas, hopefully, will need some experiments. R-152a: https://en.wikipedia.org/wiki/1,1-Difluoroethane 23-Apr-19 11:56 AM Its whats used in canned air lol. So its definitely cheap and available. 23-Apr-19 11:56 AM Another one that's likely much more difficult to get but is supposedly great for etching is R-218 23-Apr-19 11:56 AM https://en.wikipedia.org/wiki/Octafluoropropane 23-Apr-19 11:56 AM https://efgases.com/gases/pure-gases/octafluoropropane/ 23-Apr-19 11:56 AM When halocarbon 218 is exposed to the RF field generated in the etching process, a gas plasma is produced that will etch silicon dioxide or silicon nitrite with exellent selectivity. 23-Apr-19 11:56 AM because all the flourine 23-Apr-19 11:59 AM huh, I thought the cans use 1,1,1,2-tetrafluoroethylene / R134a 23-Apr-19 11:59 AM Nope, my friend found out its R-152a 23-Apr-19 11:59 AM at least here they do 23-Apr-19 11:59 AM check, it may not be... 23-Apr-19 11:59 AM I am pretty sure R-152a is what all canned air duster is 23-Apr-19 11:59 AM because it should be cheaper 23-Apr-19 11:59 AM unless your canned air duster is as expensive as R-134a refrigerant cans 23-Apr-19 11:59 AM we can get canned air duster for like 3 bucks a can here lol 23-Apr-19 12:00 PM lol, fire alarm in munich central station and no one cares about the sirens 23-Apr-19 12:00 PM nah this is fine 23-Apr-19 12:00 PM I'll need to get an RGA to anaylize my output gasses from this process to figure out what deadly stuff I'm making 23-Apr-19 12:04 PM I'll look up the gas once I'm home 23-Apr-19 12:04 PM probably hydrogen flouride and carbonyl fluoride are the two biggest concerns 23-Apr-19 12:45 PM ha! 23-Apr-19 12:45 PM https://www.amazon.de/Trend-Time-%C2%AE-www-Trend-Time-ErsatzFlasche-Dosen-Luftdruckfanfaren/dp/B07DL6NHDN 23-Apr-19 12:45 PM Inhalt: HFC 134a - Tetrafluoroethane 23-Apr-19 12:49 PM weird... but that's an air horn... maybe R-134a has a different vapor pressure and works better for airhorns and thus is worth the extra cost? 23-Apr-19 12:49 PM but to be honest... R-134a will not work well for etching I'm pretty sure so uhm... eh... 23-Apr-19 12:50 PM pretty sure the non burnable air in a can is also r134a 23-Apr-19 12:50 PM no i just wanted to make sure because I was doubting my memory 23-Apr-19 12:50 PM er actually 23-Apr-19 12:50 PM <0xDBFB7#9254> @a_quiet_scientist almost certainly unhelpful, got nerdsniped but couldn't finish 23-Apr-19 12:50 PM <0xDBFB7#9254> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_from_2019-04-23_15-49-41-16AA9.png 23-Apr-19 12:50 PM R-134A should be better I guess... 23-Apr-19 12:50 PM I think we just need to do some tests. 23-Apr-19 12:50 PM Once I get setup for this stuff I'll try everything. 23-Apr-19 12:52 PM hehe 23-Apr-19 01:00 PM Just going to be fun trying to not kill myself with this stuff. 23-Apr-19 01:00 PM well you've made it so far 23-Apr-19 01:00 PM I'd like to try and have the output gasses not be like super deadly stuff, even if I have to put something on the output to do more processing with more chemicals. 23-Apr-19 01:00 PM I've not bought any chemicals and weird gasses so far 23-Apr-19 01:00 PM aka I've done nothing lol 23-Apr-19 01:01 PM Just stop caring and buy an xray machine like me :D 23-Apr-19 01:01 PM I've been looking into it forever 23-Apr-19 01:01 PM I have xray machines that will tell me the exact elemental composition of stuff. What can your xray machine do? 23-Apr-19 01:01 PM Take an image of internals? 23-Apr-19 01:02 PM at an extremely low resolution, yes, yes they can 23-Apr-19 01:02 PM Uh 23-Apr-19 01:02 PM pfft, go big or go home! prompt gamma neutron activation analysis is the way to go! 23-Apr-19 01:02 PM lol 23-Apr-19 01:02 PM You realize there's some really nice dpi on dental sensors right? I've contacted that guy on Twitter but he hasn't responded yet 23-Apr-19 01:02 PM Might have to try poking him again 23-Apr-19 01:02 PM Not that I need to spend more money being that I've already spent >$150 on ebay junk this week 23-Apr-19 01:10 PM I am working towards a 3nm resolution 23-Apr-19 01:10 PM so yaknow 23-Apr-19 01:10 PM any resolution of xray stuff compared to Electron Microscopy is bad lol 23-Apr-19 01:10 PM But yes you can tell me black blob box has electronics in it 23-Apr-19 01:10 PM the problem is if its more than like 1 or maybe 2 layers of circuitry its useless 23-Apr-19 01:12 PM that's what ct is for 23-Apr-19 01:14 PM ^ 23-Apr-19 01:14 PM And I plan on making one 23-Apr-19 01:14 PM iirc ct can go down to nm resolution 23-Apr-19 01:14 PM @Treehouseman maybe look over at andrew seltzmans site, he's currently doing that 23-Apr-19 01:15 PM Ben krasnow did a nice simple one 23-Apr-19 01:15 PM very simple 23-Apr-19 01:15 PM just to demonstrate the physics, not actually use it 23-Apr-19 01:15 PM I still find this on the level of building an SEM vs buying a used SEM.... You can BUILD an SEM but your not getting anywhere near 10nm even probably... which is what even the cheapest SEMs can get to in good shape. 23-Apr-19 01:15 PM I'd assume you can get an old CT scanner surplus for an amount of money 23-Apr-19 01:15 PM and play with that 23-Apr-19 01:15 PM but hey, build one, thats neat too 23-Apr-19 01:17 PM depends on your goal 23-Apr-19 01:17 PM I want to reverse engineer stuff 23-Apr-19 01:17 PM So getting to a few dozen lpmm is fine 23-Apr-19 01:18 PM thats the opposite of building something from scratch kinda... 23-Apr-19 01:18 PM reverse engineering a CT scanner would be reverse engineering 23-Apr-19 01:18 PM but I know what you mean, I'm being pedantic, you mean reverse engineering just the image sensor 23-Apr-19 01:18 PM No, that's my goal 23-Apr-19 01:18 PM oh you want to get a CT scanner, this is a new goal I was unaware of lol 23-Apr-19 01:18 PM Which means just getting a sensor with enough resolution 23-Apr-19 01:19 PM I just know you have no space for one atm 23-Apr-19 01:19 PM unless your going to sleep in it lol 23-Apr-19 01:19 PM You can reverse engineer technology and build it from scratch, they aren't mutually exclusive lol 23-Apr-19 01:20 PM I have been thinking of taking a old 200 kv tem a friend has and turning it into a high coherent x ray source 23-Apr-19 01:20 PM Anyone want to turn this into a voice chat? 23-Apr-19 01:21 PM I just don't know why you'd want to reverse engineering something just to build it from scratch unless your the chinese and want to clone it lol 23-Apr-19 01:21 PM @AdamMcCombs sure, but I'm at work for awhile longer 23-Apr-19 01:21 PM That's literally what I'm doing for my accelerator lol. Because it would be impossible to afford or obtain any other way 23-Apr-19 01:22 PM How is discord for data usage in voice chat? 23-Apr-19 01:22 PM No idea 23-Apr-19 01:22 PM I doubt it's optimized at all 23-Apr-19 01:25 PM I actually remember it not being the worst thing in the world when I used it last, but don't quote me on that. 23-Apr-19 01:25 PM @Applied_Ion your effectively building a consumable part though?? It would be like building an SEM filament in my mind... you can't really GET those used. Though I suppose you can't really buy a satellite used either, but that would be its a one time use item, aka consumable so... you have no other choice period in my mind. 23-Apr-19 01:25 PM but the conflat stuff your getting used 23-Apr-19 01:27 PM Consumable? The accelerator better not be consumable lol 23-Apr-19 01:27 PM your not measuring and building your own vacuum chamber, your using off the shelve parts you got used because it would be really expensive and time consuming otherwise 23-Apr-19 01:27 PM If you put an accelerator out to space and use it on something do you expect it to come back down to earth and be sold on ePay to go back up on another device? 23-Apr-19 01:27 PM or do you expect it to go up and never be seen again? 23-Apr-19 01:27 PM in my mind that makes it... consumable 23-Apr-19 01:28 PM I'm confused by what you are trying to say 23-Apr-19 01:28 PM like old rocket boosters, those were consumable until spacex was like, lets land these 23-Apr-19 01:29 PM You know the accelerator is 100% seperate from my space stuff lol 23-Apr-19 01:29 PM I am saying you can't go buy a used thruster for cheap, and reverse engineer it for your use, there is no second hand market for these thrusters really as far as I know 23-Apr-19 01:29 PM I have a 40 minute drive once I leave work in a few 23-Apr-19 01:29 PM so you have no choice but to build from scratch 23-Apr-19 01:29 PM where as a CT scanner probably could get for almost nothing surplus 23-Apr-19 01:29 PM Though I feel like you guys might kick me out for background noise after a few minutes lol 23-Apr-19 01:29 PM thus its likely more time efficient to get one and go ham on it 23-Apr-19 01:30 PM True, but it depends on your end goals 23-Apr-19 01:30 PM Sure, if you want to learn about Xrays and theory and such playing with them directly is probably a better use of your time 23-Apr-19 01:30 PM if you want a CT scanner to scan stuff around the house, buying one used is probably a better use of your time is my only point here 23-Apr-19 01:30 PM Like for me, regarding a sem, I'd rather build one from scratch than buy one, because I'm more interested in gun optics and design than the end use 23-Apr-19 01:31 PM like I want to do silicon development... So to me building an SEM from scratch is another massive project that gets in the way of my goals, so I am better off buying a used one and spending a quarter of the time getting that running 23-Apr-19 01:31 PM Yeah lol, different goals 23-Apr-19 01:31 PM Sure exactly, thats your goal, and I'd tell you to go build one and let me know how I can help 23-Apr-19 01:31 PM That was all I was expressing 23-Apr-19 01:31 PM because I see people get started on projects like that with the end goal of having an SEM 23-Apr-19 01:31 PM and all I'm trying to say is its a waste of their time if they don't want to invest in learning the knowledge of gun optics and such 23-Apr-19 01:31 PM like wanting the prize without the work 23-Apr-19 01:31 PM and its not going to be a fun time for them and its going to be... boring... probably for them 23-Apr-19 01:31 PM or its going to be a long arduous process instead of a long fun process. 23-Apr-19 01:31 PM this is just from my experience though with projects I've started and left behind lol 23-Apr-19 01:34 PM In that regard, it would definitely be more productive to learn the optics and do the hardcore modeling and design if you want a really optimized system. Though one could also be after a working demo, even if it barely works. 23-Apr-19 01:34 PM For a CT scanner, I still think it would be a cool and worthwhile challenge to build from scratch, even if you can get them surplus 23-Apr-19 01:35 PM Sure, you could at-least get a lot of the good parts of a larger unit and then use them individually 23-Apr-19 01:39 PM Though if you want to play with real xrays, tubes are weak. Gotta go full accelerator lol. Something I'd like to try with high flux xray would be xray pumping of deep UV lasers, among other things... 23-Apr-19 01:56 PM oohh fancy 23-Apr-19 02:05 PM <0xDBFB7#9254> farnsworth-pumped He-Ar 23-Apr-19 02:06 PM Not sure fusors put out enough xray flux 23-Apr-19 02:06 PM It needs to be high enough intensity to ionized the lasing gas 23-Apr-19 02:07 PM <0xDBFB7#9254> not if your name is Lowell Wood 23-Apr-19 02:07 PM Continuous devices aren't strong enough 23-Apr-19 02:07 PM Need a much higher intensity pulsed source 23-Apr-19 02:07 PM Who is Lowell wood lol 23-Apr-19 02:08 PM <0xDBFB7#9254> https://en.wikipedia.org/wiki/Project_Excalibur 23-Apr-19 02:08 PM <0xDBFB7#9254> Forged nuclear-pumped laser test results 23-Apr-19 02:08 PM <0xDBFB7#9254> sorry, stupid joke 23-Apr-19 02:10 PM Lol 23-Apr-19 02:30 PM hrmmm thinking about making an offer on this Ludlum 23-Apr-19 02:30 PM https://www.ebay.com/itm/LUDLUM-MEASUREMENT-GEIGER-COUNTER-MODEL-2/262063836785 23-Apr-19 02:30 PM its cheap already just for the ludlum, so I dunno what the probe end is but yea 23-Apr-19 02:30 PM its clean other than the battery compartment which needs some cleaning 23-Apr-19 02:30 PM I just don't like the scale on it? I am used to seeing the ludlumns with like 2-3 scales on the gauge 23-Apr-19 02:30 PM They've been trying to sell it since December 2017 lol 23-Apr-19 02:30 PM Eh I'll throw a 75 dollar offer at it 23-Apr-19 02:30 PM I think thats fair considering it needs cleanup and the probe end may be junk for all I know 23-Apr-19 02:30 PM there is no clearly marked model on it so its odd 23-Apr-19 02:30 PM Hopefully @GigaSquirrel approves :P 23-Apr-19 02:30 PM I need to get some sources once I get a Ludlum, luckily I could probably just go to my goodwill and try not to get kicked out haha 23-Apr-19 02:30 PM find some fiestaware 23-Apr-19 02:56 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190423_145523-3AFA5.jpg 23-Apr-19 02:56 PM That's what I call a clogged jet 23-Apr-19 02:57 PM eughhh 23-Apr-19 02:57 PM Really hope neither of my diff pumps look like that 23-Apr-19 02:59 PM This ain't even bad 23-Apr-19 02:59 PM I'd think you'd really have to try to make them look like that though lol 23-Apr-19 02:59 PM oh... jeez 23-Apr-19 02:59 PM is that just with use or with dump atmosphere/not enough cooling/etc? 23-Apr-19 02:59 PM Years of use 23-Apr-19 02:59 PM ah ok 23-Apr-19 03:00 PM And a bit of atmosphere 23-Apr-19 03:00 PM This is less good 23-Apr-19 03:00 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190423_150115-5D17B.jpg 23-Apr-19 03:02 PM eughhh 23-Apr-19 03:02 PM Still not awful 23-Apr-19 03:02 PM how do you clean that?? scotch bright/magic eraser at first then polishing compond to finish it off then cleaning with acetone/alcohol? 23-Apr-19 03:02 PM These don't need to be shinny 23-Apr-19 03:02 PM Wipe with acetone 23-Apr-19 03:03 PM ah ah language buddy :P 23-Apr-19 03:03 PM Wipe with alcohol 23-Apr-19 03:03 PM see how hard this is for all of us? 23-Apr-19 03:03 PM :P 23-Apr-19 03:03 PM Wait 23-Apr-19 03:03 PM you need not apply admin 23-Apr-19 03:03 PM Why didn't it censor? 23-Apr-19 03:03 PM I can say stuff too 23-Apr-19 03:04 PM Hmmm 23-Apr-19 03:04 PM just edit the message or delete it for now lol 23-Apr-19 03:04 PM I'm not going to say I don't slip up either... 23-Apr-19 03:04 PM its not slipping up in my mind 23-Apr-19 03:04 PM its having a conversation 23-Apr-19 03:04 PM unless you use it at someone aggressively 23-Apr-19 03:04 PM then its... well being rude 23-Apr-19 03:04 PM but anyway so what do you use to clean that? 23-Apr-19 03:04 PM scotchbrite? 23-Apr-19 03:04 PM steel wool? 23-Apr-19 03:04 PM whats worked best for you in the past? 23-Apr-19 03:05 PM Yeah 23-Apr-19 03:05 PM On occasion I will strap that to a drill 23-Apr-19 03:06 PM NEVER SEEN YOU DO THAT BEFORE OR ANYTHING 23-Apr-19 03:06 PM Soda blasting works well as well 23-Apr-19 03:06 PM cool, so those things have quite a bit of meat to them and taking some off won't hurt them then 23-Apr-19 03:06 PM which was my concern 23-Apr-19 03:07 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Copy_of_IMG_cihzz0-92230.jpg 23-Apr-19 03:07 PM if they were like exact interference fit parts or something it could cause a problem if you take off so much of the material through servicing 23-Apr-19 03:07 PM ah yes, how to start a steel wool fire inside a diff pump 23-Apr-19 03:07 PM stick, wool, drill 23-Apr-19 03:07 PM heh 23-Apr-19 03:07 PM I kid 23-Apr-19 03:08 PM Yeah discoloration doesn't matter, just physical obstruction 23-Apr-19 03:08 PM again, my concern was dimensions of the material 23-Apr-19 03:08 PM if you take a thou off or something... what does that do... 23-Apr-19 03:08 PM thats a lot of material, but just an example 23-Apr-19 03:08 PM over time with cleanings I assume you end up taking material off 23-Apr-19 03:09 PM Edwards says don't mess with the surface finish 23-Apr-19 03:09 PM Jeol disagrees 23-Apr-19 03:09 PM Jeol actually tried to use Edwards pumps 23-Apr-19 03:09 PM They caused to many vibrations 23-Apr-19 03:09 PM So I don't know what's up with your pump 23-Apr-19 03:11 PM hmm? 23-Apr-19 03:11 PM I don't think anything is up with my pump? 23-Apr-19 03:11 PM was there something I am forgetting? 23-Apr-19 03:11 PM Why isi used it 23-Apr-19 03:11 PM ah I dunno 23-Apr-19 03:11 PM I mean I assume there is enough mass and dampening to sort out vibrations 23-Apr-19 03:11 PM am pretty sure from the back column to the main column everything is attached via compression fittings, aka vibrations have to go through viton anyway? 23-Apr-19 03:11 PM so I guess its just not as bad 23-Apr-19 03:11 PM but I dunno how you get vibrations from spewing oil vapor like that, I mean sure I guess I can see it but man would it be small 23-Apr-19 03:11 PM I dunno maybe I should just replace the diff pump on my SEM with a cryo head :) 23-Apr-19 03:11 PM I surely have enough helium compressors lmao 23-Apr-19 03:11 PM of-course I understand the gas load from pumping down from atmosphere from the second stage everytime would just load up the cryo head pretty quick 23-Apr-19 03:11 PM but if you were only running the first stage you could probably get quite a bit of use out of it between needing to valve off and warm it up, bake it out, rough it out, etc 23-Apr-19 03:23 PM I really don't think any cryo head will be ok on a sem 23-Apr-19 03:26 PM probably another issue of vibrations 23-Apr-19 03:26 PM Yeah 23-Apr-19 03:26 PM but there are tons of ways to shock mount things 23-Apr-19 03:26 PM Still 23-Apr-19 03:26 PM Low frequency stuff is the worst 23-Apr-19 03:26 PM I would have thought high frequency like a turbo would be worse tbh 23-Apr-19 03:27 PM Both for effect on the image and how difficult it is to dampen 23-Apr-19 03:38 PM interesting, I suppose that makes sense though, lower frequency likely has a higher amplitude and thus more energy to dampen... 23-Apr-19 03:39 PM Yeah, the longer time constants make passive dampening harder 23-Apr-19 05:36 PM I’m glad I’m not the only one who forgets about the potty mouth filter sometimes 23-Apr-19 06:19 PM whats a good vacuum for mbar with a turbo on a small chamber 23-Apr-19 06:19 PM I'd assume somewhere in the x10-4/5 like similar to torr land 23-Apr-19 06:19 PM but uhg 23-Apr-19 06:19 PM all these different standards are confusing the heck out of me 23-Apr-19 06:20 PM You should be able to hit 10-7 torr 23-Apr-19 06:20 PM Even with viton 23-Apr-19 06:21 PM right ok so like 10-8 or so mbar 23-Apr-19 06:21 PM Small turbo pumping station with small chamber all viton seals at work hits upper 10^-8 torr with like 24 hours pumping 23-Apr-19 06:21 PM so my little hornet gauge is doing nothing atm 23-Apr-19 06:21 PM grr wonder if it needs caps 23-Apr-19 06:21 PM That's assuming it's very clean and leak free with minimal outgassing lol 23-Apr-19 06:21 PM this one looked like the filaments inside were super clean 23-Apr-19 06:21 PM might be the controller, I can build another I have 3 kits here... hrm 23-Apr-19 06:23 PM 10^-6 torr should be do able without much effort. 10^-4 with a turbo and no gas load is pretty high pressure considering 23-Apr-19 06:24 PM oh the gauge is realding 1.3mbar 23-Apr-19 06:24 PM like its just not doing anything 23-Apr-19 06:24 PM the parani gauge I have is off the end of the scale, below 0mmhg which is equal to torr 23-Apr-19 06:31 PM You might want to get better gauges for high vacuum lol. What gauge are you using now that is bottoming out at 1.3 mbar? 23-Apr-19 06:35 PM The hornet IGM-400 that Niklas made a controller for 23-Apr-19 06:35 PM its an ION gauge 23-Apr-19 06:42 PM That's odd, similar to the one I will use, different model by pfeiffer. Haven't tested it yet though 23-Apr-19 06:42 PM You sure the electronics are working? 23-Apr-19 06:42 PM If its reading is right, and the turbo is on, you have a massive, massive leak lol 23-Apr-19 06:42 PM How are you reading and interfacing with it? 23-Apr-19 07:19 PM was just the controller kit I must have foobared assembling 23-Apr-19 07:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_2153-D81D9.jpg 23-Apr-19 07:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_2154-2FE67.jpg 23-Apr-19 07:19 PM 2.8x10-4 torr it seems like 23-Apr-19 07:19 PM hrm 23-Apr-19 07:19 PM must still have a leak somewhere or whatever 23-Apr-19 07:19 PM or the controller isn't perfected yet 23-Apr-19 07:20 PM That's better lol, how long you been pumping for? 23-Apr-19 07:21 PM the last... hour? or two? 23-Apr-19 07:21 PM left it running while I assembled the second kit lol 23-Apr-19 07:21 PM Is this your super tiny turbo? 23-Apr-19 07:21 PM yea 23-Apr-19 07:21 PM not running at full speed too 23-Apr-19 07:21 PM Wait why not lol 23-Apr-19 07:21 PM That could be a factor 23-Apr-19 07:21 PM haven't adjusted the controller yet 23-Apr-19 07:21 PM its running at like 51Krpm instead of 75K 23-Apr-19 07:22 PM That's a big reduction, probably contributing a lot 23-Apr-19 07:23 PM ok I'll adjust that next 23-Apr-19 07:24 PM Yeah try that first, see what happens 23-Apr-19 08:26 PM Well I adjusted the frequency pot as far as it will go. 23-Apr-19 08:26 PM its up from 850hz to 1087hz 23-Apr-19 08:26 PM which gets it up to 65Krpm 23-Apr-19 08:26 PM reads 3.2x10-4mbar 23-Apr-19 08:26 PM so 2.4x10-4 torr 23-Apr-19 08:26 PM the turbo quieted WAYYYY down when adjusting the frequency up which is cool 23-Apr-19 08:35 PM Gauge totally isn't just stuck somewhere, because when I shut off the turbo and valved off the roughing it slowly started rising in pressure. 23-Apr-19 08:35 PM so yea leak somewhere, oh wow what a surprise, my used conflat/KF stuff is leaking lmao 23-Apr-19 08:35 PM or its totally just dirt inside 23-Apr-19 08:35 PM well some of this is NOS some of it is used used 23-Apr-19 11:59 PM @Conmega the ludlum looks nice, apart from the battery compartment 23-Apr-19 11:59 PM i was always under the impression that the thing is gone once a battery leaks in it 23-Apr-19 11:59 PM and you'll want to get a scale that does cpm and nothing else 23-Apr-19 11:59 PM because stuff like mr/h is 100% dependant on the detectir 23-Apr-19 11:59 PM and unless you're planning to use the thing with only one energy compensated detector it doesn't make any sense 23-Apr-19 11:59 PM and there's no closeup of the detector, no guarantee that it still works 24-Apr-19 12:27 AM is the pump i dunno reworked? 24-Apr-19 12:27 AM ahok not full speed 24-Apr-19 12:27 AM y? 24-Apr-19 02:47 AM do you guys have a good calibration method for ionisation gauges? 24-Apr-19 02:47 AM or is their geometry very the same for all individuals of them? 24-Apr-19 02:47 AM and how reliable is the current of an igp? 24-Apr-19 04:47 AM Ionization gauges response differs on geometry. Nude vs tubular gauges will behave differently. Regular gauges are more accurate than combination gauges. Readings also have to be compensated based on the gas measured. Things like gauge degassing also plays a role in accuracy 24-Apr-19 04:47 AM I have a combo gauge, an HPT-100 that while accuracy is +-10%, has some nice features like degassing, a gauge recalibration function, and range from atmosphere to 10^-9 torr 24-Apr-19 06:24 AM ok i could use 2 hornets instead of one 24-Apr-19 06:24 AM and if they differ badly something is wrong 24-Apr-19 11:25 AM ok one is not ok 24-Apr-19 11:25 AM the first one kinda correlates with the igp controller 24-Apr-19 11:25 AM the other one starts with far to less voltage 24-Apr-19 11:25 AM maybe a recap candidate? 24-Apr-19 12:36 PM so those inficon TR100 RGAs seem a lot smaller than a lot of the RGA stuff I've been seeing 24-Apr-19 12:36 PM like they usually have a 4-5 inch metal plate assembly hanging off the black box 24-Apr-19 12:36 PM but the one @Conmega posted has a Tee like an inch away 24-Apr-19 12:36 PM (https://www.ebay.com/itm/Leybold-Inficon-Transpector-XPR-TR100/183249380754) 24-Apr-19 12:36 PM so I wonder if that lacks something the others have, like an ionizer 24-Apr-19 12:36 PM or maybe it's just new enough and the tech got smaller? 24-Apr-19 12:36 PM I literally can't find any info on it 24-Apr-19 12:47 PM emailed the microscopy mailing list, let's see if anyone there knows something 24-Apr-19 01:18 PM Cool, yea I was having a hard time finding what the difference was other than maybe like resolution on the scale it generates? 24-Apr-19 01:59 PM I'm thinking lacking ionizer or electron multiplier (I think that's an amplifier 24-Apr-19 01:59 PM ) 24-Apr-19 03:26 PM I'm pretty sure it's mass range and the presence of a electron multiplyer 24-Apr-19 08:17 PM I took apart an old flange and found that it has the shiny gasket 24-Apr-19 08:17 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-9AFF9.jpg 24-Apr-19 08:17 PM “Ultra High Vacuum And its applications” by Roberts and Vanderslice. To give you an idea of the age of the book, quadrupoles and Conflat are both mentioned as brand new radical inventions the youth are experimenting with 24-Apr-19 08:17 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-5C71C.jpg 24-Apr-19 08:50 PM lol cool 24-Apr-19 10:22 PM Do they even show a B-A gauge in that book or just those two types? 25-Apr-19 12:11 AM @a_quiet_scientist do you have a pic of the open flange? 25-Apr-19 12:11 AM does it look like this? 25-Apr-19 12:11 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190425_091121-F6C12.jpg 25-Apr-19 12:14 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-1DAD6.png 25-Apr-19 12:14 AM Totally having output on that little ethernet connected rad box LOL 25-Apr-19 12:15 AM heh, sweet! 25-Apr-19 12:21 AM The data is +1.3200-02mR/hr 25-Apr-19 12:21 AM I would assume thats 1.32x10^-2mR/hr?? 25-Apr-19 12:21 AM I don't have any sources or anything 25-Apr-19 12:21 AM and I don't know what is reasonable 25-Apr-19 12:21 AM but this is an energy compensated detector 25-Apr-19 12:21 AM meaning it should be a very precise gamma detector 25-Apr-19 12:21 AM as you told me :) 25-Apr-19 12:22 AM that's pretty much spot on the average background 25-Apr-19 12:22 AM cool! 25-Apr-19 12:22 AM so it works 25-Apr-19 12:22 AM now I need fiesta ware or something lmao 25-Apr-19 12:23 AM fiestaware outputs almost no gamma ^^ 25-Apr-19 12:23 AM ah ignorant me 25-Apr-19 12:23 AM and so I am reading that right for background right? 25-Apr-19 12:23 AM the whole 10^-2 25-Apr-19 12:23 AM because the raw data is just that 1.3200-02 25-Apr-19 12:23 AM which is up to interpretation 25-Apr-19 12:24 AM well if it's 0.013 mr/h that's spot on 25-Apr-19 12:24 AM ok cool that sounds right then 25-Apr-19 12:24 AM its just broadcasting that data every 60 seconds to one of like 5 IP addresses it expects to see 25-Apr-19 12:24 AM the rest of it seems to be a time/date stamp 25-Apr-19 12:24 AM seeing how easy it is to get check sources I'd just buy one from united nuclear 25-Apr-19 12:25 AM how much are they? 25-Apr-19 12:25 AM ~100 bucks 25-Apr-19 12:25 AM oof ok I mean thats reasonable for someone who needs to calibrate stuff I guess and check things 25-Apr-19 12:25 AM but man seems like a lot for something I spent 10 bucks on lol 25-Apr-19 12:26 AM some are $79, some are $145, some are inbetween that ^^ 25-Apr-19 12:26 AM ok, is there a cheaper way to just get a source of some description? 25-Apr-19 12:26 AM uranium ore of questionable source on ePay? lmao 25-Apr-19 12:27 AM of course there's cheaper sources, but having a known one would make it easy to check calibration 25-Apr-19 12:27 AM I mean I have no way to "calibrate" this 25-Apr-19 12:27 AM I believe this is all hard coded?? unless I find an onboard serial port for management, which I may... 25-Apr-19 12:27 AM this is kinda just a hard coded hard set IP address box broadcasting readings every 60 seconds 25-Apr-19 12:27 AM the serial port on the front appears to go to another board so its useless for this 25-Apr-19 12:28 AM but you can check if the numbers you get are trustworthy 25-Apr-19 12:28 AM sure 25-Apr-19 12:28 AM but I don't need a detector like this every day?? and to be honest the readings above backround tells me more than an accurate reading, with at-least my current interest into nuclear stuff 25-Apr-19 12:29 AM anyway, radium gets some good gamma dose rate per activity, try to get some military radium painted stuff 25-Apr-19 12:29 AM So its good to know I can get a good source for 100 bucks but I don't need to spend that atm haha 25-Apr-19 12:29 AM ah cool okie 25-Apr-19 12:29 AM like radium paint? 25-Apr-19 12:29 AM aye 25-Apr-19 12:30 AM my friend was wearing a watch that sets his ludlum off like crazy but thats alpha/beta/gamma detector end 25-Apr-19 12:30 AM its hillarious he just had a kid and the doctor was like do you have any other questions? and he was like uhm... what about my radioactive watch and holding the kid? and he was like it should be fine lmao 25-Apr-19 12:30 AM normal watches output almost nothing, but the military stuff is coated so thick that you easily get in the µSv/h range 25-Apr-19 12:31 AM his is an old watch which i want to say was used for airforce or something like that 25-Apr-19 12:31 AM one of those models of watch 25-Apr-19 12:31 AM old bulivia I want to way 25-Apr-19 12:31 AM oh, that might actually output something 25-Apr-19 12:31 AM yea... on the ludlum it sounds crazy lol 25-Apr-19 12:31 AM eh maybe I'll rig this little module up to a raspberry pi with networking, get it powered off a battery, and go through some stores with it or something lmao 25-Apr-19 12:31 AM now that I know it does SOMETHING 25-Apr-19 12:31 AM but I'd like to get it giving a reading more than every 60 seconds 25-Apr-19 12:31 AM kinda boring 25-Apr-19 12:33 AM many monitoring stations make their output rate dependant on the doserate change 25-Apr-19 12:33 AM hrm ok 25-Apr-19 12:33 AM https://www.lndinc.com/products/geiger-mueller-tubes/71210/ 25-Apr-19 12:33 AM this is the tube 25-Apr-19 12:33 AM I assume its gamma only anyway 25-Apr-19 12:38 AM yep, energy compensated is always gamma only, as betas don't get through the filter 25-Apr-19 12:38 AM yea its a 2mm Silver filter 25-Apr-19 12:38 AM what about alphas? 25-Apr-19 12:38 AM Sn is tin, not silver 25-Apr-19 12:38 AM duh tired 25-Apr-19 12:38 AM sorry 25-Apr-19 12:38 AM XD 25-Apr-19 12:39 AM no worries 25-Apr-19 12:39 AM alphas are pretty much stopped by anything 25-Apr-19 12:51 AM https://media.discordapp.net/attachments/529468991652233216/570879545511510016/DSC_2175.jpg 25-Apr-19 12:51 AM https://media.discordapp.net/attachments/529468991652233216/570879545511510018/DSC_2174.jpg 25-Apr-19 12:52 AM heh, looks like the whole thing is made by ludlum 25-Apr-19 12:52 AM wait 25-Apr-19 12:52 AM now I am confused 25-Apr-19 12:52 AM how many of those PCBs do you have? 25-Apr-19 12:54 AM I don't think so... I think the rabbit board that sits on there controls alarms in the system 25-Apr-19 12:54 AM we bought 3 of the big boxes, I only kept one 25-Apr-19 12:54 AM because those two don't match up: https://media.discordapp.net/attachments/529468991652233216/570879545511510016/DSC_2175.jpg https://cdn.discordapp.com/attachments/513115950501855261/570011634790170634/DSC_2039.jpg 25-Apr-19 12:54 AM the other two are going to friends respectively 25-Apr-19 12:54 AM yea different designs 25-Apr-19 12:54 AM its weird 25-Apr-19 12:55 AM ah, ok 25-Apr-19 12:55 AM there are plenty of similarities but yes it is different 25-Apr-19 12:55 AM but yea I believe they just had Ludlum cal these 25-Apr-19 12:56 AM hm, ok 25-Apr-19 12:56 AM weird stuff anyways 25-Apr-19 12:56 AM Yup, I believe the MSP430 chip on the bottom does all the radiation stuff so the weird rabbit module with ethernet is not even a part of the equation here hopefully 25-Apr-19 12:57 AM are you still missing something? 25-Apr-19 12:57 AM you're getting output, what else do you want? 25-Apr-19 12:58 AM I mean every 60 seconds over a specific IP address 25-Apr-19 12:58 AM so its kinda... klunky... 25-Apr-19 12:58 AM the MSP430 is probably just sending serial to the red rabbit module 25-Apr-19 12:58 AM with the reading in a higher freqency I bet 25-Apr-19 12:58 AM and even if it isn't I can dump the MSP430 and modify the code basically 25-Apr-19 12:59 AM ah, right 25-Apr-19 12:59 AM but don't make the integration too short, otherwise you'll get weird results 25-Apr-19 12:59 AM well not weird but just... less usefull 25-Apr-19 02:24 AM Calibrating radiation detectors is a complex specialised thing... I mean if you only need gamma dose in uGy/h you can use a point source of 137Cs of known activity (because detector response changes with energy they are typically calibrated for a known radioisotope of given energy) 25-Apr-19 02:24 AM because detector response changes with energy they are typically calibrated for a known radioisotope of given energy Energy compensation fixes this ^^ 25-Apr-19 02:26 AM At the very least you need to get a “real” small radioactive source. Or ideally (especially if it is important for safety) send it out to a specialist. 25-Apr-19 02:26 AM And calibration of the instrument is really the rate meter and the probe/detector as a set together 25-Apr-19 02:27 AM +1 25-Apr-19 02:28 AM Even with energy compensation you need a known radionuclide because you need the gamma factor for that nuclide. 25-Apr-19 02:28 AM gamma factor? 25-Apr-19 02:28 AM for measuring dose rate you don't need a specific energy, as long as it is in the compensated range 25-Apr-19 02:28 AM if you want to do sth. like measuring activity you'll need to calibrate with a known source 25-Apr-19 02:31 AM http://www.iem-inc.com/information/tools/gamma-ray-dose-constants 25-Apr-19 02:32 AM ah, yes 25-Apr-19 02:32 AM that just saves you from a bit of maths for calibration 25-Apr-19 05:55 AM moin 25-Apr-19 06:00 AM Somebody requested a pic of this flange - there’s no groove at all, it’s flat with a gold seal 25-Apr-19 06:00 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-DE414.jpg 25-Apr-19 06:02 AM ah, ok 25-Apr-19 06:02 AM thanks! 25-Apr-19 09:36 AM https://media.discordapp.net/attachments/529468991652233216/571011096786501632/DSC_2174.jpg 25-Apr-19 09:36 AM So yea, its probably just spitting the readings from the gieger tube out over that serial line over to the main controller that spits out TCP/IP every 60 seconds 25-Apr-19 09:36 AM But the main 5V regulator can take in anywhere from 7.4V to 40V so I could theoretically run this off a 9V battery :) 25-Apr-19 09:36 AM I'll just need to throw another micro on there and drive a display from the serial line, or dump the MSP430 chip and hack that up 25-Apr-19 10:07 AM Hey @GigaSquirrel a friend posed the question, would a gamma detector like this pick up xrays? 25-Apr-19 10:08 AM Sure 25-Apr-19 10:08 AM gammas and x-rays are both high energy photons, the difference in name only comes from different origins of the photon 25-Apr-19 10:11 AM Cool! Ok 25-Apr-19 10:11 AM many people think something like <100 keV is x-ray and above is gamma 25-Apr-19 10:11 AM but that's bullcrap 25-Apr-19 10:11 AM gamma comes from the nucleus and x-rays from the electron shells 25-Apr-19 10:13 AM Right 25-Apr-19 10:13 AM That makes sense 25-Apr-19 10:13 AM I mean if you want to not get into arguments just say high energy photons and let them figure out what you mean lmao 25-Apr-19 10:14 AM yep 25-Apr-19 10:14 AM I'll have to see when I crank my SEM to 40kV someday if I can get any detection of xrays out of the side of the chamber where we have a bodge on there. 25-Apr-19 10:14 AM because at 25kV on that ludlum detector my friend has we saw nada 25-Apr-19 10:14 AM probably still won't at 40kV 25-Apr-19 10:14 AM there just isn't enough emmision current when around 100uA 25-Apr-19 10:15 AM hm, most compensated tubes are blind below 30 keV 25-Apr-19 10:15 AM there is also that 25-Apr-19 10:15 AM but yea the little KF16/25? blanking plate probably blocks it all 25-Apr-19 10:15 AM even if it is just aluminum 25-Apr-19 10:16 AM not sure about that 25-Apr-19 10:16 AM I've got a 30 kV power supply on my fusor, the 2-3mm ss walls of the chamber block everything, but the 5mm Al feedthrough lets out hell of a lot 25-Apr-19 10:16 AM https://www.youtube.com/watch?v=soKkkPy-tmg And that's with a counter that's not rated for anything below 45 keV 25-Apr-19 10:16 AM if you want to detect slight amounts of x-rays get one of these for your ludlum https://twitter.com/GigaBecquerel/status/1116716091248644106 25-Apr-19 10:19 AM ohhh very nice 25-Apr-19 10:19 AM I need to get some scintilation material for my pmt 25-Apr-19 10:19 AM I was thinking about tearing apart a smoke detector as a test sample because bla its easy and accessable 25-Apr-19 10:19 AM Well, aside from my xray cassettes, those aren't sensitive enough and for a different purpose 25-Apr-19 10:20 AM @GigaSquirrel what do I search on ePay for that scintillator you got? 25-Apr-19 10:20 AM It'll put out a tiny amount of gamma, but mostly alpha, if that tube is meant for gamma only it'll barely register, my gmc doesn't get more than a few clicks per second with the smoke detector sources 25-Apr-19 10:20 AM I think I'm going to pull the trigger on this ludlum 25-Apr-19 10:20 AM https://www.ebay.com/itm/LUDLUM-MEASUREMENT-GEIGER-COUNTER-MODEL-2-/262063836785 25-Apr-19 10:21 AM Even though those are stupid hot alpha that would drive a scintilation detector crazy 25-Apr-19 10:21 AM I can recommend the gmc detectors 25-Apr-19 10:21 AM I like mine, the more modern ones would be even nicer 25-Apr-19 10:26 AM that's a bicron scintillation detector 25-Apr-19 10:27 AM https://www.ebay.com/itm/BICRON-SAINT-GOBAIN-CRYSTALS-AND-DETECTORS-1-12x1-12m3-1-12-l/223381977245 25-Apr-19 10:27 AM ? 25-Apr-19 10:27 AM heh, that's the seller I bought mine from 25-Apr-19 10:27 AM accepted a $30 offer 25-Apr-19 10:28 AM oh wow ok 25-Apr-19 10:28 AM that makes it more reasonable lol 25-Apr-19 10:28 AM That's integrated crystal and detector? 25-Apr-19 10:28 AM I guess you just need to but a BNC or whatever connector you need on the end? 25-Apr-19 10:29 AM Aye 25-Apr-19 10:29 AM can be connected as is to the ludlum 25-Apr-19 10:29 AM Does it cover alpha? 25-Apr-19 10:29 AM nice 25-Apr-19 10:29 AM Nope, only photons 25-Apr-19 10:29 AM Ah, damn 25-Apr-19 10:29 AM and this is why we don't waste money on those GMC things, because ludlums are so versitile lol 25-Apr-19 10:29 AM there are very few alpha sintillators and even fever scintillation detectors 25-Apr-19 10:29 AM you can get plenty of alpha detectors for a ludlum @Treehouseman 25-Apr-19 10:29 AM the GMCs are way overpriced for what they are 25-Apr-19 10:29 AM https://twitter.com/GigaBecquerel/status/1116772739606560770 25-Apr-19 10:30 AM I know, but I like the idea of something compact and kinda discreet 25-Apr-19 10:30 AM like most of them I've seen anyway are like alpha/beta/gamma detectors 25-Apr-19 10:30 AM Good for checking stuff at stores 25-Apr-19 10:30 AM I got my gmc for like $50 25-Apr-19 10:30 AM like the 44-7 detector end is apparently pretty sensitive for an a/b/g 25-Apr-19 10:30 AM the 44-9 is basically the go to for a/b/g 25-Apr-19 10:30 AM But does it support 802.11? 25-Apr-19 10:31 AM ffs 25-Apr-19 10:31 AM >.< 25-Apr-19 10:31 AM Add neutron and it's a/b/g/n, still not any better LOL 25-Apr-19 10:31 AM I don't know of any abgn detector, but that would be interesting 25-Apr-19 10:32 AM 2 detectors in one assembly? 25-Apr-19 10:32 AM Makes the assembly detector a/b/g/n 25-Apr-19 10:33 AM ah ok, so the 44-9 looks like a slightly larger scintillator compared to the 44-7 25-Apr-19 10:33 AM I guess there's too much overlap in the scintillation events to discriminate between the different particles 25-Apr-19 10:33 AM https://www.ebay.com/itm/Ludlum-Model-14C-Survey-Meter-And-Ludlum-Model-44-9-Probe-PARTS-ONLY/273717676807 25-Apr-19 10:33 AM I think you're getting mixed up with terms here, @Conmega 25-Apr-19 10:33 AM scintillator and GM are two very different ways to detect radiation 25-Apr-19 10:33 AM also the 14c often goes for cheap because it can only do 900V, instead of at least 400-1500 like all the others 25-Apr-19 10:36 AM I see, I did a little bit of reading now 25-Apr-19 10:36 AM though I also see two different styles of 44-9 model detector ends... 25-Apr-19 10:36 AM pancake and that one listed above 25-Apr-19 10:36 AM or like a little pancake thing on the end of a handle 25-Apr-19 10:36 AM https://www.ebay.com/itm/Ludlum-3-w-44-9-GM-Pancake-Probe-Geiger-Radiation-Survey-Meter-Alpha-Beta-Gamma/254203314773 25-Apr-19 10:36 AM which is a GM 25-Apr-19 10:37 AM that's a 44-9, the one above looks like a 44-7 25-Apr-19 10:38 AM I know, but it appears to say 44-9 on it... weird... anyway so a 44-7 thats a scintilator? and the 44-9 is a GM 25-Apr-19 10:38 AM I'd assume by its shape its got a PMT in it? the 44-7 that is 25-Apr-19 10:39 AM nope 25-Apr-19 10:39 AM oh jeez ok haha guess its not always obvious 25-Apr-19 10:39 AM just look on the website of ludlum, they always say what detector type 25-Apr-19 10:39 AM ok 25-Apr-19 10:46 AM most are GMs 25-Apr-19 11:10 AM Thank you for the educational conversation lol 25-Apr-19 11:11 AM haha, ask away if you've got any more questions ^^ 25-Apr-19 11:13 AM I have yet to really learn much about different types of radiation and such since I don't handle or use it regularly really?? Or at-least have to deal with it like you do haha 25-Apr-19 11:13 AM Like I see how xrays from electron bombardment for EDS can be useful, and some people where were starting to educate me on how neutrons can be useful for certain things, but yea still learning what I could want or use other types of radioactive sources for other than like @Treehouseman 's want for radium paint to make things glow lmao 25-Apr-19 11:19 AM I expect that vial to go for a few hundred 25-Apr-19 11:19 AM It's already got 2 bids 25-Apr-19 11:19 AM vial? 25-Apr-19 11:20 AM https://www.ebay.com/itm/Lot-of-Luminous-Radium-Salts-Paint-for-clock-Watch-hands-and-dials-SUN-RAY-25/264295331487?_mwBanner=1&ul_ref=https%3A%2F%2Frover.ebay.com%2Frover%2F0%2F0%2F0%3Fmpre%3Dhttps%253A%252F%252Fwww.ebay.com%252Fulk%252Fitm%252F264295331487%26rvr_id%3D0%26rvr_ts%3D55ba38b216a0ac3d8cc05352ffd73ac7&ul_noapp=true&pageci=526b19fd-b7f1-4319-8b9f-884ca3640cd5 25-Apr-19 11:21 AM oof 25-Apr-19 11:21 AM no 25-Apr-19 11:21 AM don't hold that in your hand 25-Apr-19 11:21 AM don't be near it 25-Apr-19 11:21 AM I wanna taste it 25-Apr-19 11:21 AM and really, really don't ship it 25-Apr-19 11:22 AM Lolol 25-Apr-19 11:22 AM if that vial breaks everyone in the room this package is opened in is fücked 25-Apr-19 11:24 AM yeaa 25-Apr-19 11:24 AM can't imagine radium inhalation is good for you 25-Apr-19 11:25 AM for radium you get into the range of mSv per incorporated Bq 25-Apr-19 11:25 AM that vial is easily in the MBq range 25-Apr-19 11:25 AM totally worth it for glowing watch hands! 25-Apr-19 11:25 AM ^ 25-Apr-19 11:25 AM This 25-Apr-19 11:26 AM if it breaks and you bring the dust in the air you could easily inhale a lethal dose 25-Apr-19 11:26 AM What's life without a little risk 25-Apr-19 11:26 AM its been around for how many years and not broken yet :) 25-Apr-19 11:26 AM lol 25-Apr-19 11:26 AM It aint like the xray isn't going to do it for me as it is 25-Apr-19 11:27 AM it isn't broken yet, but give it some days with a disinterested postman... 25-Apr-19 11:27 AM its just a dental Xray I mean 25-Apr-19 11:27 AM That can still do it 25-Apr-19 11:27 AM sure if you leave it on all night pointed at you in bed 25-Apr-19 11:28 AM They're lower energy than large units, it absorbs more 25-Apr-19 11:28 AM with normal dental x-ray units the tube would burn out before you get a lethal dose 25-Apr-19 11:28 AM If you want to do it on one sitting 25-Apr-19 11:28 AM also so 1 mSv/h is 100 mR/h? 25-Apr-19 11:29 AM Aye 25-Apr-19 11:29 AM not sure what you mean by mSv per incorporated Bq? whats Bq? 25-Apr-19 11:29 AM Bq is becquerel, it's a measure of decay rate 25-Apr-19 11:29 AM 1 Bq is one decay per second 25-Apr-19 11:29 AM same as Ci, there's just a factor between them 25-Apr-19 11:31 AM Ahhh I see, so with a given Bq if you have one atom for example you'd have one count of a given output, but with the more material you have the decay rate doesn't go up, you just have more decaying at the same rate and thus giving higher count rates 25-Apr-19 11:31 AM No 25-Apr-19 11:31 AM ^^ 25-Apr-19 11:31 AM (ignoring daughter products) Decay rate is getting lower with time, as more atoms have decayed 25-Apr-19 11:33 AM I still want that vial :P 25-Apr-19 11:33 AM Ah right of-course 25-Apr-19 11:33 AM if I've got 1 kBq of a radionuclide after 1 half life I've got 500 Bq 25-Apr-19 11:39 AM Ah ok ok that makes sense 25-Apr-19 11:44 AM Yep 25-Apr-19 11:46 AM @Conmega https://www.nwnlabs.org/s/Nuclear-Physics-1-NWNC.pdf 25-Apr-19 11:46 AM https://www.nwnlabs.org/s/Nuclear-Physics-2-NWNC.pdf 25-Apr-19 11:47 AM and http://users.lngs.infn.it/~dimarco/Radiation%20Detection%20and%20Measurement,%203rd%20ed%20-%20Glenn%20F.pdf if you want to learn about detectors 25-Apr-19 11:47 AM That's the doe handbook on nuclear physics, the first few chapters of part 1 will give you a really good primer on the fundamentals 25-Apr-19 11:47 AM It's what we use to bring students up to speed on whats up with these atom things 25-Apr-19 11:50 AM The 101 course is fun and all, but which one starts teaching how to split them? :P 25-Apr-19 11:51 AM pff 25-Apr-19 11:51 AM splitting them is easy 25-Apr-19 11:51 AM but keeping up a chain reaction is the hard part 25-Apr-19 11:53 AM cool thanks! 25-Apr-19 11:58 AM Gotta go for the combo high score 25-Apr-19 12:01 PM activating yourself enough that you can't be burried? 25-Apr-19 02:32 PM That's one heck of a life goal there 25-Apr-19 02:32 PM Needing to be buried in a lead lined coffin 25-Apr-19 02:53 PM nah just dump me in the final disposal site 25-Apr-19 02:53 PM throw a geiger counter in there that ticks happily and I'll be resting in peace 25-Apr-19 03:21 PM Make it so bad that they wind up sealing you inside chernobyl 25-Apr-19 04:05 PM If you inhale or ingest a certain activity (Bq) of a certain radionuclide (say 226Ra) then using both its biological behaviour (elimination from the body), chemistry and physical half-life you can calculate the total integrated dose (radiobiological equivalent dose, in Sv) over time from that intake, using a factor known as the committed effective dose equivalent or CEDE. 25-Apr-19 04:20 PM I’d like a standard charge sensitive preamplifier - a “building block” to reuse for multiple projects and for other scientists to reuse - an open source sort of thing. I could use something like the HP5554A from the manual but it’s quite old and impossible to get appropriate transistors. I wonder if a modern solution incorporating opamps could beat it 25-Apr-19 04:20 PM Has anyone ever come across a schematic like that? 25-Apr-19 04:59 PM Amptek seems to have fet frontend folowed by one of their amplifier IC's 25-Apr-19 04:59 PM Hmm. This reminds me that I found a baggie of 20pcs of some random expensive sounding jfet's at work few years back. 25-Apr-19 04:59 PM I should check if they ware Amptek. 25-Apr-19 04:59 PM Some dude's charge sensitive amplifier http://w3.atomki.hu/ar98/d/d07/d07.html 25-Apr-19 04:59 PM Uses some jfet folowed by AD8011 op-amp 25-Apr-19 06:42 PM Amptek is not good as a standard building block because they are $$$$ 25-Apr-19 06:42 PM And they don’t make the JFET just the ic 25-Apr-19 06:42 PM Amptek reference design calls for a 2SK152 but they are not easy to get - 25-Apr-19 08:34 PM Coooolll! 25-Apr-19 08:34 PM Snooping Serial at the same time as the rabbit transmitting a packet: Serial data: 00000001720000000000001000000500000975105000L 00000001720000000000001000000500000975105000L 00000001720000000000001000000500000975105000L 00000001720000000000001000000500000975105000L 200144400000000100000050000097510500000400685350 00000001720000000000001000000500000975105000L TCP Packet: LMI25000001444001101/04/1980RAD READING 0617 +1.7200-02mR/hr 25-Apr-19 08:34 PM So the MSP430 just spews R/hr ratings in the format: 000.000017200 00000000001000000500000975105000L 25-Apr-19 08:34 PM with whatever that extra stuff is... 25-Apr-19 08:34 PM I've never seen it read below 0.01mR/hr accuracy so I dunno why the extra zeros are there 25-Apr-19 08:34 PM but yea 25-Apr-19 08:34 PM neat 25-Apr-19 08:34 PM and the MSP430 spits out that R/hr figure like every 2-3 seconds instead of the 60 seconds the little ethernet board does 25-Apr-19 08:34 PM So way more useful 25-Apr-19 08:34 PM It seems to take in serial config??? like when I transmit something to it it stops transmitting, but I will have no idea what it is expecting until I dump the MSP430's code and dissasemble it 25-Apr-19 08:34 PM https://media.discordapp.net/attachments/529468991652233216/571178698275946498/DSC_2184.jpg 25-Apr-19 08:34 PM Also the msp430 and the geiger tube on the board with the rabbit module removed consumes around 20-50mAh at 8V 25-Apr-19 08:34 PM so you'd probably only get like 5-7 hours battery out of a 9V which isn't great... 25-Apr-19 08:34 PM there are other things on the board that take power and if desoldered may improve this quite a bit 25-Apr-19 08:34 PM like there are little 5v relays... 25-Apr-19 08:34 PM if those are being held or powered for some reason... yeaa... 26-Apr-19 12:37 AM @a_quiet_scientist I'm working on just that ^^ 26-Apr-19 12:44 AM https://arxiv.org/pdf/1904.09726 26-Apr-19 12:44 AM "An inexpensive biasing system for use in electrostatic steering of ions" 26-Apr-19 12:44 AM <=$500 26-Apr-19 12:44 AM "We introduce a design for an electronic device capable of superposing 8 bias voltages up to ±48V on a voltage of up to 1.5 kV. Such a device has been implemented to provide biasing of a beam steerer-shifter system for use in aligning an ion beam with the optical axis of a multi-reflection time-of-flight mass spectrograph. The device features a 16-bit digital interface both to set and to monitor the applied voltages, and can be built for less than $500 USD. By selection of higher isolation components, the design could allow operation up to 10 kV or more." 26-Apr-19 02:05 PM Does someone know of a good chart/diagram of the different products swagelok makes and their male/female counterparts with like cutaways, consumable parts if applicable, etc? Because there are tonsss of different standards and like its really confusing looking at 10 different types of connections saying yup its swagelok and not knowing EXACTLY what type it is and what its good for. 26-Apr-19 02:05 PM I have an old Swagelok parts catalog but there has to be a better single or couple of page thing... 26-Apr-19 02:12 PM Er I guess some of the stuff I have isn't specifically swagelok though they may make it too 26-Apr-19 02:12 PM like VCR fittings, not sure if that was a swagelok brand originally or someone else 26-Apr-19 02:12 PM I guess I've figured out what I have mostly by random googling and such... tube fittings and vcr... but yea, surprised there isn't like an identification sheet or something easily available 26-Apr-19 03:55 PM Yea 26-Apr-19 03:55 PM Tho it sounds like one gets to make their own chart. 26-Apr-19 10:28 PM @Conmega what book/catalog do you have now? 27-Apr-19 12:59 AM @nmz787 the way I usually do that sort of thing for TOF ion gating is with a 12v-to-48V isolated DC-DC module (or a couple in series if they are 24V out) and an optocoupler, ensuring that the DC-DC and the optocoupler have several kV isolation ratings. Then you just sit the whole thing on top of a 2kV power supply, so “ground” is not case ground it’s the 2kV rail, and you can turn on and off your 48V pulses superimposed on the HV. 27-Apr-19 12:59 AM Swagelok eDTR (electronic desktop technical reference) is only available as an iPad app which is a bit annoying. A Swagelok encyclopaedia with pictures would be really nice 27-Apr-19 08:20 AM @Conmega I think swagelok has a big app note on identifying fluid connectors. Either that or it was Parker. Measure od, measure thread pitch, look at general style, etc. 27-Apr-19 08:42 AM @a_quiet_scientist @rfs some clever stuff going on in that link, mostly from the cited design. It takes a bunch of gain in the FET stage. I was expecting a source follower. L1 is a puzzle though. http://w3.atomki.hu/ar98/d/d07/d07.html 27-Apr-19 08:42 AM I guess a charge sensitive amp is basically a transimpedance amp with low input capacitance and reasonably high bandwidth? 27-Apr-19 08:46 AM I guess. 27-Apr-19 08:56 AM I am confident there is not deep irreducible magic in the amptek ic, especially if they are using an external fet. And the fet itself is almost certainly a particular selected version of a standard part. Many jfet characteristics are highly correlated with the saturation current, the main variable beyond that is whether it is a big or small device. Wrt leakage current (especially for mosfet), that is something that is almost always orders of magnitude smaller that the specified (tested) limit. Much money was made, back in the day, by testing 10's of different transistor die into thousands of specs. 27-Apr-19 05:39 PM <0xDBFB7#9254> Quick question: 27-Apr-19 05:39 PM <0xDBFB7#9254> is brass that's been electroplated with nickel likely to be vacuum compatible? 27-Apr-19 05:40 PM How high vacuum? 27-Apr-19 05:40 PM <0xDBFB7#9254> KJL et al have things to say about brass vapor pressure 27-Apr-19 05:40 PM <0xDBFB7#9254> oh, 10^-5 mbar 27-Apr-19 05:40 PM <0xDBFB7#9254> 10^-6 torr 27-Apr-19 05:40 PM <0xDBFB7#9254> brass might be at elevated temperature though 27-Apr-19 05:40 PM <0xDBFB7#9254> like 300 c 27-Apr-19 05:41 PM Idk, that's like on the border. Brass is a very poor material for high vacuum. If it's being heated, you definitely don't want to use it for sure 27-Apr-19 05:41 PM What's the application and part? 27-Apr-19 05:41 PM Any reason to not use copper or aluminum instead? 27-Apr-19 05:41 PM <0xDBFB7#9254> electron extraction electrode 27-Apr-19 05:41 PM <0xDBFB7#9254> right next to a 2000 K filament 27-Apr-19 05:41 PM <0xDBFB7#9254> so yeah 27-Apr-19 05:41 PM Oh, no need to use brass for that 27-Apr-19 05:42 PM <0xDBFB7#9254> My lathe can't do copper unfortunately 27-Apr-19 05:42 PM SS is usually the most common option for electron optics 27-Apr-19 05:42 PM Why can't the lathe do copper? 27-Apr-19 05:42 PM Brass and copper both very easy to machine 27-Apr-19 05:43 PM <0xDBFB7#9254> having spent the better part of a few hours trying to hold reasonable tolerances with copper 27-Apr-19 05:43 PM <0xDBFB7#9254> this HF minilathe inclines to disagree 27-Apr-19 05:43 PM <0xDBFB7#9254> (probably user error, actually) 27-Apr-19 05:43 PM <0xDBFB7#9254> but I stripped a few teeth off a belt and blew a fuse 27-Apr-19 05:43 PM <0xDBFB7#9254> on one particularly agressive parting op 27-Apr-19 05:44 PM How close is the electrode to the filament? 27-Apr-19 05:45 PM <0xDBFB7#9254> 0.2 mm 27-Apr-19 05:45 PM <0xDBFB7#9254> previous electrodes got very hot indeed 27-Apr-19 05:45 PM <0xDBFB7#9254> this is a terrible idea 27-Apr-19 05:45 PM <0xDBFB7#9254> and I will fill my chamber with a monolayer of zinc. 27-Apr-19 05:45 PM That's really close lol, is it a grid or a electrode with central hole? 27-Apr-19 05:45 PM <0xDBFB7#9254> electrode with hole - pierce/wehnelt style 27-Apr-19 05:46 PM Yeah I'd say brass is not a good choice for this lol 27-Apr-19 05:46 PM Farther spacing u might be able to get away with it, but this spacing is practically touching lol 27-Apr-19 05:46 PM <0xDBFB7#9254> yeah 27-Apr-19 05:46 PM <0xDBFB7#9254> thanks for the advice! I shall go find some other material. 27-Apr-19 05:47 PM How complex is the electrode? 27-Apr-19 05:47 PM You got pictures or model of it? 27-Apr-19 05:47 PM <0xDBFB7#9254> ~15 stages 27-Apr-19 05:47 PM <0xDBFB7#9254> 'fraid not yet 27-Apr-19 05:48 PM What's this for? Homemade sem or something else? 27-Apr-19 05:49 PM <0xDBFB7#9254> something slightly more cloak-and-dagger 27-Apr-19 05:49 PM <0xDBFB7#9254> actually neither cloak nor dagger 27-Apr-19 05:51 PM Tem? 27-Apr-19 05:51 PM <0xDBFB7#9254> NDA 27-Apr-19 05:52 PM Fair enough lol, I've got some projects that aren't ready for public release yet 27-Apr-19 05:54 PM <0xDBFB7#9254> it's not nearly as cool as your ion thruster, I can assure you! 27-Apr-19 05:54 PM <0xDBFB7#9254> (and the corresponding bamf test system) 27-Apr-19 05:57 PM Eh, the thruster isn't really cool if it doesn't work to begin with! Thruster stuff is all fully available though, so no secrets with that one! 27-Apr-19 05:58 PM <0xDBFB7#9254> that's the way to do it 27-Apr-19 06:19 PM I don't care if your thruster works or not (though I'm sure it will), totally jealous of your HV work bench @Applied_Ion lol 27-Apr-19 06:19 PM I am working on a similar 8020 thing since I got an 8020 table from HGR Inc recently for cheap. 27-Apr-19 06:19 PM Probably mount both turbo pumps in it on either side so I can have two test chambers, should barely have enough space under for two roughing pumps on the underlying support frame. 27-Apr-19 06:19 PM Still hunting down an adapter for the one darn turbo 27-Apr-19 06:19 PM its like ISO160 never shows up... I've only seen a few parts... 27-Apr-19 06:19 PM Theres an ISO160-100 adapter elbow thing up atm but its a bit large and excessive for what I need 27-Apr-19 06:30 PM @Conmega nice! How big is the 8020 table? I was originally gonna do multiple chambers on one table, but I decided to consolidate it as 1 pumping station for multiple chambers to save money, and just use 6" CF inlet for everything 27-Apr-19 06:30 PM Turns out I made a dumb mistake that set me back a few days. The HPT-100 can communicate either through RS-232 to gauge controller or RS-485 through pfeiffer protocol. I ended up writing the communication code for the latter, and bought the UART to rs232. Problem is, there isn't info how to use rs232, just interfaces with their controller. Rs485 can be written directly from computer. So now I'm waiting for the right adapter lol 27-Apr-19 06:30 PM Once I verify communication and plotting in my MegunoLink control panel, I can finally turn this thing on 27-Apr-19 06:38 PM <0xDBFB7#9254> covers a pressure range from 1,000 to 5 · 10-10 mbar 27-Apr-19 06:38 PM <0xDBFB7#9254> whew, that's a slick gauge 27-Apr-19 06:42 PM Yeah, if it works it will be super nice 27-Apr-19 06:42 PM Also has degas and calibration function as well 27-Apr-19 06:42 PM I got 3 for $40 each on ebay, plus another with broken filaments, but the electronics should still be good 27-Apr-19 06:43 PM <0xDBFB7#9254> nice 27-Apr-19 06:43 PM <0xDBFB7#9254> just break an old incandescent light for the filament 27-Apr-19 06:43 PM <0xDBFB7#9254> it'll be fine 27-Apr-19 06:43 PM <0xDBFB7#9254> yttrium? more like yitrigone 27-Apr-19 06:47 PM Lol, problem is it's not super accessible, and if the filament isn't same size and material, readings would possibly be off. The electronics detach from the head though, so they should be swappable if ones got a bad box 27-Apr-19 08:14 PM oh wow thats a fancy gauge I'll have to keep an eye out for one. 27-Apr-19 08:14 PM Also I'll get a photo of the table here in a bit... 27-Apr-19 08:14 PM er oh heres a bad photo of it 27-Apr-19 08:14 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_2172-BE66A.JPG 27-Apr-19 08:14 PM Thing was like 140 or so dollars, which for the amount of 8020 and the fact that most of the surface is like half inch thick delrin... it was a great deal 27-Apr-19 08:14 PM and there is a few pneumatic parts and enclosures with some PLC stuff in it 27-Apr-19 08:14 PM like yea, love surplus :) 27-Apr-19 11:47 PM https://twitter.com/ConnorKrukosky/status/1122391809185984512?s=19 28-Apr-19 12:34 AM moin 28-Apr-19 01:54 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_2189-A6F1A.JPG 28-Apr-19 01:54 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_2190-458CF.JPG 28-Apr-19 01:54 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_2191-DD355.JPG 28-Apr-19 01:54 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_2192-B2D2E.JPG 28-Apr-19 01:54 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_2193-E5EE9.JPG 28-Apr-19 02:06 AM @Applied_Ion the 8020 table is 40"x30" in its x/y dimensions. 28-Apr-19 02:06 AM I expect to be-able to barely squeeze two roughing pumps and two turbos under there, would only really work if I had the exact pieces I need. Might end up just making it one chamber with a few load locks and such, that's also a possibility. It'll probably morph over time since I have no real design down like you do :) 28-Apr-19 02:06 AM But yea that 8020 thing with all the parts and pieces for 140 bucks was nice 28-Apr-19 02:06 AM There was a lot of din rail stuff in there, 4x 24V 4.5A I think it was industrial PSUs two cute little PLCs, two pneumatics valves which I may use, may not since I have other valves I like. A bunch of PTC pneumatic stuff, two estop buttons, some light break detectors, a few 30A din rail fuses, some din rail relays. A festo air filter and regulator, a festo air filter without regulator, and those two wonderful din rail boxes, one of which will probably go back on the chassis after I get some custom pneumatics for vacuum control since a lot of my vacuum valves are pneumatic. 28-Apr-19 02:20 AM Lovely big sheet of Delrin 28-Apr-19 02:20 AM It’s a great material 28-Apr-19 02:26 AM its a few "chunks" since those holes that were there held aluminum plates with fictures on it 28-Apr-19 02:26 AM but yea love the delrin surface 28-Apr-19 04:07 PM That’s such a great deal for all the stuff. It’s a neat little 8020 table 28-Apr-19 04:27 PM Yea the place had a ton of them but I only bought the one on the sale day and the rest were sold the day before. Didn't realize they would get bought up so fast. But I only really ended up having room for one. 28-Apr-19 06:25 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_2194-670CE.JPG 28-Apr-19 06:25 PM Mounted up the turbo. 28-Apr-19 06:25 PM Via scrap aluminum bits from some boxes I tore apart. 28-Apr-19 06:34 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_2195-00AFF.JPG 29-Apr-19 12:37 AM moin 29-Apr-19 12:37 AM Moin! 29-Apr-19 12:37 AM are there any complications with indium in UHV applications? 29-Apr-19 12:38 AM Nope, indium is a pretty common seal 29-Apr-19 12:38 AM only issue is the lowish melting point 29-Apr-19 12:39 AM if the bakeout temp doesn't exceed 135 deg celsius everything should be fine? 29-Apr-19 12:39 AM oof 29-Apr-19 12:39 AM melting point is 150°C 29-Apr-19 12:40 AM just asking to be sure(rerish) 29-Apr-19 12:40 AM I would not go above 100, for that temp I can be sure it doesn't melt / become a problem 29-Apr-19 12:41 AM hmm 29-Apr-19 12:41 AM my chambers window is sealed with indium, I baked that at 100°C 29-Apr-19 12:41 AM i use 120 29-Apr-19 12:41 AM with 15 margin if there is something wrong 29-Apr-19 12:42 AM hmm 29-Apr-19 12:42 AM it might work 29-Apr-19 12:42 AM I just can't tell you from experience if it does ^^ 29-Apr-19 12:42 AM is 100 realy enough? 29-Apr-19 12:42 AM from what I understood any temp is enough and hotter just makes it faster 29-Apr-19 12:42 AM ok 29-Apr-19 12:42 AM ok 29-Apr-19 12:42 AM how many orders of magnitude faster? 29-Apr-19 12:44 AM No idea 29-Apr-19 12:44 AM me too 29-Apr-19 06:33 AM Yeah, any elevated temp will help, higher is better (assuming the materials are compatible ) 29-Apr-19 06:33 AM You won't get orders of magnitude reduction at 100 C though lol 29-Apr-19 06:33 AM Also it depends what level you are trying to achieve 29-Apr-19 06:33 AM If you are going for UHV, high temp baking is a requirement anyway 29-Apr-19 06:33 AM Lots of factors involved, which is why it's so difficult to calculate 29-Apr-19 06:33 AM For the bonded gas, you will want to look at the energy required to desorp it from the surface. Input energy must be higher than this for a given gas 29-Apr-19 06:33 AM Under 10^-8, it's mainly water vapor 29-Apr-19 06:33 AM UV prep can be very effective as well, and UV bulbs in the chamber can decrease pumpdown time by a factor of 2 29-Apr-19 06:33 AM For water vapor at least 29-Apr-19 06:38 AM Why uv? 29-Apr-19 06:38 AM What makes it speed up pump down? 29-Apr-19 06:39 AM It is effective at breaking the bonds for water vapor on surfaces. I'll have to go back through my resources, but it is very efficient, and a specific reason why it's a factor of 2 reduction 29-Apr-19 06:39 AM And if uv works, what about gamma/xray? 29-Apr-19 06:39 AM More energy more better right? 29-Apr-19 06:39 AM :P 29-Apr-19 06:40 AM I don't think there is data for that, no one uses gamma/x rays to precondition a chamber lol 29-Apr-19 06:41 AM Well, time to do some science then! 29-Apr-19 06:42 AM It might not be effective, since they will pass straight through the chamber walls. UV stops at the surface, and it is specifically surface adsorbed water vapor you want to remove 29-Apr-19 11:19 AM yeah i use uv lamps for monolayer destruction 29-Apr-19 11:19 AM but they shine through the viewports 29-Apr-19 11:19 AM but better than nothin 29-Apr-19 11:20 AM Yeah, through viewports can still be effective 29-Apr-19 11:21 AM yep 29-Apr-19 11:43 AM Upgrade to fancy fused quartz for better efficiency :P 29-Apr-19 12:53 PM I don't have data on it but we use x rays to precondition chambers in electron guns all the time 29-Apr-19 12:59 PM Neat 29-Apr-19 03:20 PM Now that I have the Turbo pump mounted to the table I will have to spend some time trying to figure out where my leak is. I don't know if I have a KF40 blank so I may need to just throw a 2.75" blank over where the KF stuff was hanging off. But then I won't be-able to connect the ion gauge... Hrm.. 29-Apr-19 03:20 PM I'm going to have to dig through stuff to figure out how simple I can make my chamber without sacrificing the ion gauge 29-Apr-19 04:37 PM I can't imagine xray conditioning is much effective, I never seem anything in any literature using it specifically for conditioning 29-Apr-19 04:55 PM @Conmega have you tried going 'round all the seals and gaskets and viewports and feedthroughs with a syringe of isopropyl? 29-Apr-19 04:55 PM demounting everything and hunting for leaks is liable to introduce new ones when you put it all back together; better if you can narrow it down without tearing it all apart 29-Apr-19 04:57 PM I agree with @qualia 29-Apr-19 04:57 PM I forget, is isopropyl compatible with viton? 29-Apr-19 04:57 PM I'm like a day or two from first pumpdown, gonna probably need to leak check as well lol 29-Apr-19 04:58 PM yeah isopropyl and viton are compatible 29-Apr-19 04:58 PM no acetone though 29-Apr-19 04:58 PM K good lol 29-Apr-19 04:59 PM i'm really excited for your pumpdown! i really hope you don't encounter any massive issues, but you've been real meticulous up to this point so i kinda doubt it 29-Apr-19 04:59 PM Man I'm nervous as hell though, this is it lol. A year of work finally tested 29-Apr-19 04:59 PM @qualia thanks. I hope I won't have issues, but even with meticulous prep something could always go wrong 29-Apr-19 04:59 PM I just have no idea what to expect 29-Apr-19 04:59 PM Especially if the cooling system can't handle the diff pump lol 29-Apr-19 05:01 PM do you have a gate valve in front of your diff pump? 29-Apr-19 05:01 PM or like any kinda shutter besides the baffle? 29-Apr-19 05:02 PM Nope lol, I sacrificed that for speed, cost, and reducing further gas loads with more large o rings 29-Apr-19 05:02 PM if you haven't already, do a bunch of system characterization before you even turn on the diff pump at roughing pressures 29-Apr-19 05:02 PM see what the leakup rate, if any, is like, and low-end pressure 29-Apr-19 05:04 PM Oh yeah lol I got the thing instrumented well. I will be plotting data fir cooling and vacuum and looking at everything. At least using 705 oil instead of 704 will help with backstreaming. If I can keep baffle below ambient, it will help a bunch as well 29-Apr-19 05:04 PM also if anything like a viewport is gonna implode then better to do it into a cold diffusion pump 29-Apr-19 05:04 PM Yeah I have pre pumped with the roughing pump already, viewport is in great condition 29-Apr-19 05:04 PM >.> i don't know how common that is but i worry about like smacking a wrench into my viewport like constantly and turning my turbo into hypervelocity tinsel 29-Apr-19 05:04 PM ah ok! 29-Apr-19 05:05 PM If this goes well, I will probably be firing the engine this weekend. Got a couple more things coming in for ebay for the hv supplies 29-Apr-19 05:05 PM there's seemingly a real big safety factor on viewports 29-Apr-19 05:05 PM eee :3! 29-Apr-19 05:05 PM hey, what do you use for charging your cap bank? anything fancy? 29-Apr-19 05:05 PM also also, got any papers/schematics for rogowski integrators, or do you just do it in-scope? 29-Apr-19 05:06 PM A variac and rectified transformer lol. I'm waiting for the variacs. The igniter will be driven with an old thyratron trigger chassis I haven't revealed yet, which is pretty cool. Got like 3 of them 29-Apr-19 05:06 PM I have a bunch of papers on rogowskis 29-Apr-19 05:06 PM I can share those 29-Apr-19 05:06 PM For this test, I will probably use my small Pearson current transformers into the scope 29-Apr-19 05:06 PM They are only rated to 500A though, not sure how big the main bank discharge will be 29-Apr-19 05:08 PM i've got some intensive design work to do with my caps before i dump any coulombs into 'em 29-Apr-19 05:10 PM These caps are tiny, don't need much energy for thrusters 29-Apr-19 05:10 PM and my thyratrons are extremely tempting to try a low-energy firing with. i only have a filament transformer, though, and i'm gonna need a fast & non-jittery couple of millijoules at around 5-10kv iirc to light 'em 29-Apr-19 05:10 PM that seems like a fun transmission line design project 29-Apr-19 05:11 PM Yeah, I've thought about doing some pulse charged tlines with the thyratron pulser as a demo 29-Apr-19 05:11 PM Will be using one at least for triggering my accelerator bank as well 29-Apr-19 05:11 PM They were originally used as triggers for massive thyratrons for driving klystrons 29-Apr-19 05:12 PM ooo 29-Apr-19 05:12 PM my whole assembly is part of the advanced test accelerator induction rf linac, and these cx1538 tubes were also used at one point for driving some klystrons iirc 29-Apr-19 05:13 PM Nice! 29-Apr-19 05:13 PM but the risetime sucks, compared to most of the big ridiculous ceramic deuterium thyratrons they were kicking around at that point in the 80s 29-Apr-19 05:13 PM buuuut they're cheap and plentiful 29-Apr-19 05:14 PM We still use the big ceramic deuterium ones 29-Apr-19 05:14 PM I think rated 50kv, 6kA 29-Apr-19 05:18 PM these things can handle a lot of current.. but the risetime leaves a bit much to be desired. still, though... i got one positive hold-off and one negative hold-off, to see if there's much difference in performance between the two in my application 29-Apr-19 05:18 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/1556583333_20190429-170433-E0537.png 29-Apr-19 05:18 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/1556583460_20190429-170440-FA156.png 29-Apr-19 05:19 PM What I really want to play with is photoconductive semiconductor switches. Switching levels of thyratrons, super low jitter and much faster rise times. Though rep rate is very limited. More modern induction linacs and dielectric wall accelerators use these since you can synchronize the timing of the blumleins driving the linac very accurately with low jitter 29-Apr-19 05:20 PM also like everything's very ring-friendly so i can maybe not be super ridiculously meticulous about critically damping the whole thing, which is great bc i barely know what i'm doing there 29-Apr-19 05:20 PM Yeah thyratrons can take a beating lol 29-Apr-19 05:20 PM oooh 29-Apr-19 05:21 PM Also I believe the Z machine marxes use PCSSs for synchronizing firing of the marxes 29-Apr-19 05:21 PM For the triggers 29-Apr-19 05:21 PM Oh yeah, for those of you intetested in pulsed power, there is a new advance in tech the past decade or so on a new type of generator. They will be using it for the Z machine upgrade 29-Apr-19 05:21 PM It's called a Linear Transformer Driver 29-Apr-19 05:21 PM Combines the advantage of Marx/pulse forming line stages into a single stage 29-Apr-19 05:28 PM briefly considers a pulsed power channel.. very briefly 29-Apr-19 05:29 PM I'd be game for that lol 29-Apr-19 05:33 PM might figure out the thing when i get home.. i'm gettin' too distracted >_> 29-Apr-19 05:33 PM this way lies incredible ebay impulse-buys 29-Apr-19 05:33 PM sci-hub's ssl cert expired. the universe is clearly saying 'get back to work, slacker' 29-Apr-19 05:37 PM Also @qualia I went around with a heavily soaked kimwipe, need to get an empty syringe for better test... Not sure if your injecting liquid in or the vapors are what block up the leaks. 29-Apr-19 05:37 PM But the only part I really suspect is the stuff going off to orings and such, I have a good feeling most of the conflat should be OK 29-Apr-19 05:37 PM some of the parts were brand new, just old stock so they should be OK, I am only suspect of most of the KF stuff hanging off the side of my chamber since that was all older, used and was quite dirty before some cleanup. 29-Apr-19 05:38 PM the vapors might if you got the atmosphere around it all concentrated enough, but ime the liquid and its low viscosity working around o-rings and such makes all the difference in actually finding leaks with less than ridiculously precise measurement equipment 29-Apr-19 05:38 PM And the one CF 2.75 I plan to "remove" and swap some parts out on is using one of those CF viton rings for an easy swap between stuff, so it may be that leaking even. 29-Apr-19 05:38 PM Ah ok, I'll have to get an empty syringe then 29-Apr-19 05:40 PM the one major irritating leak on my chamber, that i've yet to properly fix, is actually on my turbopump itself. super annoying.. 'cos, like, the shroud part that has the CF flange slips up and off the thing and can be replaced with a different shroud to get ISO/whatever 29-Apr-19 05:40 PM and that gasket is huge and last i looked at it it was kinda grimy on the inside 29-Apr-19 05:40 PM gotta work up the wherewithal to carefully heft a hundred pounds of stainless around to get it off the bolt mounts >.> 29-Apr-19 05:40 PM but yeah, definitely qualify everything up in sequential pieces with as many valves as you've got access to. like, make sure your whole foreline is ok and bottoms out/stays bottomed out nicely 29-Apr-19 05:40 PM alsoalso, if you have Daiso stores where you're at (japanese dollar store), they have three-packs of cheap plastic syringes with thin metal tubes for $1.50 29-Apr-19 05:45 PM never heard of Daiso 29-Apr-19 05:47 PM i wish they were more common.. i only know of 'em existing in washington/seattle-ish and california, aside from japan 29-Apr-19 05:47 PM https://www.amazon.com/Bstean-Syringe-Blunt-Tip-Needle/dp/B01HFTYINS/ref=sr_1_4?keywords=syringe&qid=1556585182&s=gateway&sr=8-4 29-Apr-19 05:47 PM probably just grab this set of stuff 29-Apr-19 05:47 PM oh perfect 29-Apr-19 05:47 PM i.. might also >.> 29-Apr-19 06:00 PM Holy $*** gauge is reading and verified. Apparently my chamber has been at 10 torr for a week since my roughing check lol 29-Apr-19 06:00 PM I think I am actually clear for pumpdown 29-Apr-19 06:00 PM Gonna run a roughing check again and see if gauges are in agreememt 29-Apr-19 06:00 PM Well, they should read differently from the pump inlet to chamber gauge for roughing 29-Apr-19 06:22 PM Not much different I would think, but yea. 29-Apr-19 06:36 PM ooh nice! that bodes well for sure 29-Apr-19 06:59 PM Yea awesome to see it held for that long! 29-Apr-19 06:59 PM conflat is nice :) 29-Apr-19 06:59 PM I am really tempted to re-configure my chamber to my larger conflat bits, pump down would be slow... but I'd love to be-able to use some of my other passthroughs and such 29-Apr-19 06:59 PM Oh hrm... I forgot about the one "chamber" I have 29-Apr-19 06:59 PM an old CF 10" cryo pump housing with a CF 6" coming off the side along with some other connections like 1.33" conflats for some smaller passthroughs 29-Apr-19 06:59 PM It does have limited feed ins though so it would be somewhat limited 29-Apr-19 07:29 PM Well, not there yet. I can definitely communicate and pull values on my test arduino, but in the main MegunoLink code it won't display the values at all 29-Apr-19 07:29 PM Worst case scenario I use a seperate arduino and display on a lcd, got parts for that as a backup in the event this exact thing happens lol 29-Apr-19 07:29 PM Well, at least temp data still displays. Now is the best time to start pumping, ambient is 14C... 29-Apr-19 07:29 PM And I've got a dead TC channel as well. It will be an absolute miracle if I ever see high vacuum 29-Apr-19 07:55 PM At least TC is not dead, probably just the chip. That's easy to replace 29-Apr-19 07:59 PM Okie, got an ISO100 throttle valve so I can add throttling to my little turbo, and seal it off when I decided to open the chamber so I don't have to wait for spindown to open. 29-Apr-19 08:31 PM Ok, so I think I figured out my data issue. Since I'm using 2 serial ports on the mega, and 1 serial port is constantly polled by the timing I set in megunolink, it never had time to send or receive the commands for the second serial reading. I added some delays, I seem to be getting a reading now. 29-Apr-19 08:31 PM Times like this I hate having no idea what I'm doing when it comes to programming embedded stuff, I'm still mostly winging it 29-Apr-19 08:34 PM I could help with that 29-Apr-19 08:34 PM I know code lol 29-Apr-19 08:35 PM I can't code for s***. I think I got it worked out, but I can't turn pump on and verify since it's super loud and late. Tenants might not appreciate that lol. 29-Apr-19 08:45 PM I swear at this rate I'm just going to forego data acquisition and just use an arduino with lcd display on every individual thing that needs reading. 29-Apr-19 08:45 PM Just quickly looking at before and after, my rate of rise also seems really high. I'll take this as foreshadowing to more bad news 29-Apr-19 09:21 PM Well once VCF E is over this coming weekend I'll see about helping you on a data acquisition system that isn't crap. Should be-able to get it on one Mega no problem. And just using the arduino libraries it shouldn't take me too long. The better way would be to use C directly and forgo the arduino stuff, but I have yet to actually do that on an Arduino, only on other chips. 30-Apr-19 01:03 AM I’m tempted to say CAN or something like that for modular data acquisition 30-Apr-19 01:03 AM Arduino GPIB ? 30-Apr-19 01:39 AM I really shouldn’t drink a pint of monster just before suiting up for cleanroom 30-Apr-19 04:23 AM Oh Lordy he comin 30-Apr-19 04:23 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-B7DD5.jpg 30-Apr-19 06:07 AM woah 30-Apr-19 07:09 AM If you ever need to do liftoff of micro devices and struggle with it, use the photoresist toluene soak, it’s magic 30-Apr-19 11:15 AM Fixed one issue, another pops up. I don't think megunolink can handle large amounts of decimals. For graphs, I can display the values down to 10^-6, but can only adjust the graphs on 10^-5 increments. Their table to display values directly seems like it can only handle 2 decimals. Can't believe after all this work, lousy data display is holding me back so much lol. I emailed them, see what they say first. If it's their program, I'm going to lcd and turning this thing on. I'm gonna brute force this if I have to and I will run this until it catches fire if needed. 30-Apr-19 11:15 AM Anyone got any alternative data display/acquisition solutions that is low cost, can take multiple analog and digital inputs, serial, and ideally doesn't use programming harder than arduino? I feel like my current solution is less and less desirable as I progress lol. 30-Apr-19 12:21 PM I can probably live with the graphing for now. Not perfect but it will do short term. For the table, I can display the number and exponent seperately, so that should work to get around decimal limitations. Going to see endgame tonight, but tomorrow I will hopefully be firing up the diff pump. Other supplies will arrive so I can start setting up the pulser and hv supplies for the engine as well. 30-Apr-19 01:01 PM @a_quiet_scientist from what I hear thats a small cryo pump :) My friend works on a process line for vapor deposition with cryo pump openings big enough to crawl through into the chamber heh... And to clean the vapor deposition line they literally have to put scaffolding inside and walk inside it. 30-Apr-19 01:01 PM @Applied_Ion I mean, for me anyway, to do data acquisition, my first thought would be to just spew a semi formatted data over serial, so you can make a very simple program on the PC in python or something to take that data and plot it or whatever. No need to over complicate it. Otherwise you can always use a graphic LCD or color LCD or graphic OLED, something on the arduino for immediate feedback. 30-Apr-19 01:05 PM Yeah I can't program lol. Arduino and MegunoLink has made it super easy to set up a user interface with minimal skill, but it does come with some drawbacks. I'm sure it would work better if I was better at it lol, I can't knock the program completely. It's worked amazing for the cooling system data lol 30-Apr-19 01:05 PM I think I got the major issues worked out for now which will allow me to do pumpdown tests 30-Apr-19 01:09 PM Hrm, Maybe I should work towards some kind of general vacuum system controller that's cheap and semi universal for people. Vacuum gauge reading is hard since everyone uses a different standard, but some gauges support switching an output relay at certain setpoints which would still allow for triggering other system components. 30-Apr-19 01:09 PM Cool! Yea get it working, just baby-sit it :) 30-Apr-19 01:09 PM I've gotta say, I really like the HPT-100 30-Apr-19 01:09 PM Because oh man is it great when code runs away into the weeds when something critical is running :) 30-Apr-19 01:10 PM The UART to rs485 converter works flawlessly, and very easy to send and receive commands 30-Apr-19 01:10 PM Best part is it isn't like 0-10v output, instead it puts out a string that you convert to a float after so you get a lot more resolution 30-Apr-19 01:10 PM Neat, they look like nice gauges, but there aren't many on the use market it seems and they are expensive. 30-Apr-19 01:10 PM Sure, many of the parani gauges and such nowadays do that, and I'm sure a lot of the Ion gauges and controllers will do similar, but ion gauges are expensive, controllers are expensive. 30-Apr-19 01:12 PM Everything is expensive in vacuum lol 30-Apr-19 01:12 PM I mean the IGM-400 has a controller now that someone designed that basically slaps an STM32 on it, so I could program in uart controls now. 30-Apr-19 01:12 PM Also, it does atmosphere to 10^-10 torr. 30-Apr-19 01:12 PM once you put a microcontroller on something the sky is the limit 30-Apr-19 03:06 PM @Applied_Ion how long have you been pumping before looking at your leak rate? 30-Apr-19 03:11 PM I was just roughing, haven't turned diff pump on yet. Don't remember, maybe an hour while I was fiddling with the software. I'm fairly certain though the leaking is in the roughing side, I think I know where the main issue is. 30-Apr-19 03:12 PM If you roughed down and were measuring with dif pump oil that hadn't been pumped with yet then I wouldn't be surprised... 30-Apr-19 03:14 PM Makes sense. On my prior check I got to 20 millitorr blanked off through the diff pump though. I'm only hitting 40 now, but I'm pretty sure it's where the rubber gum hose is clamped 30-Apr-19 03:18 PM Why is that? 30-Apr-19 03:20 PM I don't think it's clamped as well as the first time lol. Everything else is kf and conflat 30-Apr-19 03:21 PM Normally with gum rubber I don't even have to clamp it 30-Apr-19 03:23 PM This one is larger diameter, should've got one size down 30-Apr-19 03:31 PM I'll probably put an order in for the right size, this works for now. 30-Apr-19 05:21 PM data acquisition is a hard and annoying problem. i grabbed a mega2560 a long while ago with the intent of doing some alternative thing not involving megunolink ('cos i don't use windows, mostly) and the thing that's caught my eye most recently is actually a library called Firmata which, afaict, exposes the entirety of an arduino's I/O capabilities directly to a host computer, to be interfaced with in software. i'd planned to do (persistent!) graphing with InfluxDB + Grafana, and write some control logic on a dedicated little computer (like a raspi or something) 30-Apr-19 05:21 PM also, like your setup, i also grabbed that same big 'ol relay board 30-Apr-19 05:21 PM Firmata seems to solve the issue of 'i want to write complicated logics and datalogging functionality but am too lazy to learn to do so on a tiny underpowered single-threaded 8-bit uC', and the rest is just oodles of python, probably 30-Apr-19 05:44 PM That sounds reasonable tbh 30-Apr-19 06:03 PM But yea arduinos are very outdated nowadays... so many other dev boards for cheap with much more powerful chips on them. And to be honest the arduino IDE/bootstrap/coding enviroment/libraries are much more restrictive than just programming chips in C. Its more effort, but once you've gotten one project out of the way its much more smooth. 30-Apr-19 06:03 PM But I can respect people's time and not wanting to invest a bunch of time in learning programming for microcontrollers and learning how to scan through a thousand page datasheet for the stuff you need. Its a real pain. 30-Apr-19 06:03 PM I think the whole datalogging thing is an issue in of itself though since everyone will have a different preference on how they want their data formatted, viewed, etc. So while the microcontroller can probably be done and tucked away, the PC side of the software and such can be a much bigger pain. Its then much more reasonable to find some toolchain with the features you want. But in some cases I could see this leaving you with more work depending on what the toolchain requires/etc. 30-Apr-19 06:03 PM I think the whole having to learn to code thing is just a major part of data collection nowadays. Unfortunately its not as easy as HP made it back in the 80s with their micro/minicomputers with basic and HPIB and how simple that whole system was. It can, with some products, be simplier, with others, way more complex. But all in all, whether it be basic, or C, or Verilog/VHDL you need to learn something I feel, in at-least a basic capacity, to do different types of data collection just because you'll have a different opinion on how to do it than if you had someone else do it for you. 30-Apr-19 06:03 PM Though that's not to say you MUST learn to program, can always just get digital/analog readouts on everything and take notes by hand, but this will only get you so much accuracy. Which for many projects I am sure could be OK. 30-Apr-19 06:03 PM And if you really want computer controlled data collection, but don't want to learn it yourself but would rather pay someone, just learn how to express your needs very well to the other person, and when they express that the way you suggest might be a challenge, talk it out, discuss other possibilities. I think many people who don't know how to code think you can just do anything any way with all the same ease, take the same amount of code and same amount of effort. This is really far from the case. Its like saying propulsion can be generated from any form of energy storage just as easily as the other. Ok, let me know when you get a man to the moon using purely the stored power of rubber bands. :P 30-Apr-19 06:50 PM TBH if you’re a scientist today you should learn some basic exposure to code. It doesn’t matter if you’re in chemistry or biology, I would advise all grad students to have a little bit of basic experience with code, at least some. And that should equally apply to those in their garage rather than the university system 30-Apr-19 06:50 PM Also for Arduino users - try using PlatformIO. Use the same language, same code, but the IDE is far better, programming the device and building is much faster, managing libraries is much easier, git integration, testing integration, it’s black, tabbed IDE, support for loads of different hardware 30-Apr-19 07:07 PM I agree coding is valuable and needed, it's just one of my weakest skills lol. Can't be a pro at everything. But I can do enough to get by. Compared to all the other engineering and prep I've done for the whole thing, the code is a tiny part. 30-Apr-19 07:07 PM I just use arduino cause that's what I've been exposed to in the past and can get stuff running. Besides, I've already got the real time graphing and logging implemented lol, just getting around the last bugs. Anxious to start the real work. 30-Apr-19 07:47 PM here's a GUI I wrote that plots data that was acquired serially https://github.com/kanzure/culture_shock/blob/master/tk_adc_gui.py 30-Apr-19 07:47 PM I basically just spy on a serial terminal program, then grab the output, throw it onto a TK canvas element 30-Apr-19 07:47 PM key functions are "read_serial" https://github.com/kanzure/culture_shock/blob/master/tk_adc_gui.py#L73 30-Apr-19 07:47 PM and "replot" https://github.com/kanzure/culture_shock/blob/master/tk_adc_gui.py#L139 30-Apr-19 07:47 PM here's what that GUI looks like https://imgur.com/a/I3CLt 30-Apr-19 07:47 PM as far as "arduinos are outdated" I really have to disagree... it's all about what your application is 30-Apr-19 07:55 PM I still think arduino is great 30-Apr-19 07:55 PM I use it for a lot of stuff 30-Apr-19 07:56 PM I mean in the literal sense the chips are outdated, they are old, there are newer chips now that do the same thing that will have longer term support, and well while I think the arduino code is great to get you started, as soon as you realize a digitalwrite takes FOREVER like its really slow... you should hopefully move on to writing code in C to avoid problems due to the bad libraries that arduino comes with. 30-Apr-19 07:56 PM Like cortex M0s or the newer TI MSP430s are great, STM32 (aka the blue pill boards which you can also run arduino bootloader on) 30-Apr-19 07:58 PM Arduino has a lot of support and projects that are much easier for someone with my level of coding can follow, copy, and modify. 30-Apr-19 07:58 PM Like I understand they can still be used, but it would be a shame to see someone invest a ton of time into an older Atmel product, then decide to use a similar chip and find out its all different from what you've learned 30-Apr-19 07:58 PM a digital write is a function of the clock speed 30-Apr-19 07:58 PM and as such you can make said product without tearup. 30-Apr-19 07:58 PM For reference, here are my monitoring screens: 30-Apr-19 07:58 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Control-System-Vacuum-System-Data-Screen-4-09975.jpg 30-Apr-19 07:58 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Control-System-Cooling-System-Data-Screen--16C8F.jpg 30-Apr-19 07:58 PM nothing to do with the era of chip design 30-Apr-19 07:59 PM Weird, picture is clipped, but u get the idea lol 30-Apr-19 07:59 PM https://www.peterbeard.co/blog/post/why-is-arduino-digitalwrite-so-slow/ 30-Apr-19 07:59 PM @Applied_Ion looks pretty simple 30-Apr-19 07:59 PM @nmz787 no the way arduino implemented digitalwrite... its bad... really bad 30-Apr-19 07:59 PM @Conmega just use direct port manipulation 30-Apr-19 07:59 PM I think you're conflating the arduino ecosystem with the actual hardware underlying 30-Apr-19 08:00 PM Works for what I need right now. Just looking at analog and digital values once a second to make sure stuff isn't going sideways lol 30-Apr-19 08:00 PM @Conmega https://www.arduino.cc/en/Reference/PortManipulation 30-Apr-19 08:00 PM I understand that's one way around it 30-Apr-19 08:00 PM but again, my point is your better off learning more about the hardware your working with and working on a lower level. 30-Apr-19 08:01 PM also for something like PWM, you should be using the hardware timer IPs, not the CPU 30-Apr-19 08:01 PM I love arduino because it's a single download and I'm all ready to go 30-Apr-19 08:01 PM I can do low-level C/C++ or even inline ASM 30-Apr-19 08:01 PM right from their kid-friendly GUI 30-Apr-19 08:02 PM Not enough time in the day unfortunately. Like literally. I'm getting up early, I work during my lunch break, I do stuff after work for these projects. Already a full time second job doing R&D on everything else, just need a simple solution to monitor stuff right now 30-Apr-19 08:02 PM the toolchain is super fast to get up and running 30-Apr-19 08:02 PM Its like owning an SEM and just wanting to learn to use it vs learning how it works at a more fundamental level. I think it goes to say you need to learn at-least SOMETHING about its underlying function to use it. Not just the top level stuff. Not to say you can't get by with just that top level knowledge. I am arguing that learning the lower level information, like how to configure the UART on your chip, can help you understand problems as they occur. 30-Apr-19 08:03 PM it's a cost tradeoff... if you want to cheap-out on the hardware, you need to invest on learning how to squeeze every drop of performance out of it 30-Apr-19 08:03 PM same with SEM 30-Apr-19 08:03 PM if you just want to use it, spend half a mil and get a 10 year service contract 30-Apr-19 08:03 PM done. 30-Apr-19 08:04 PM And I think that programming, the biggest part of it is debugging... which no-one ever knows how to do it seems. Like the last programming course I took... eughhh god it was horrible. 30-Apr-19 08:04 PM idk, I learned GDB in college CS 30-Apr-19 08:05 PM This class... the teacher didn't ONCE explain the error output when it popped up 30-Apr-19 08:05 PM when he made a mistake, he would go quiet, and think about it 30-Apr-19 08:05 PM ratemyprofessor.com 30-Apr-19 08:06 PM then some kid would shout "you forgot a parenthesis" or something. 30-Apr-19 08:11 PM @Conmega that article you sent is a little weird that they disassemble the binaries, rather than starting with a source-code view https://github.com/arduino/ArduinoCore-avr/blob/b7c607663fecc232e598f2c0acf419ceb0b7078c/cores/arduino/wiring_digital.c#L138 30-Apr-19 08:15 PM I dunno, that was the classic article that started the conversation over digitalwrite being slow that I remember looking at years ago. But yea I prefer decent IDEs that help you write code... The arduino IDE practically fights you lmao. 30-Apr-19 08:15 PM And yes you can write C/C++/ASM inline with the arduino stuff, but if your going to do that... you find yourself writing all C, then whats the point of the Arduino fluff at that point? 30-Apr-19 08:15 PM I just found myself spending more time trying to understand broken libraries than just reading datasheets and writing my own half the time, and when using a good IDE it just really helps you write code oh my god. The money and time that has gone into some of the well developed IDEs over the years... 30-Apr-19 08:31 PM I'm all about Cypress PSoC microcontroller. 30-Apr-19 08:31 PM PSoc 5LP is da bomb. It's got some nice analog bits, a DSP, digital logic (can run verilog), and a nice IDE. I'm not sure why nobody seems to use it. 30-Apr-19 08:53 PM Senior capstone was around the cypress psoc for me. Unfortunately I couldn't code, so I had to work on other stuff. Everyone automatically assumes all EEs are coding wizards... 30-Apr-19 08:53 PM Seems like a pretty cool system though, haven't looked into it in a while 30-Apr-19 08:53 PM Speaking of code, I think I got a work around for displaying the high vacuum gauge values 30-Apr-19 08:53 PM I think all that's left is a couple more supplies to wire, and I can start pumpdown 30-Apr-19 08:53 PM Looks like tomorrow will be the day lol 30-Apr-19 08:53 PM From yesterday's roughing check, looks like residual is pressure is 3.3 torr 30-Apr-19 09:09 PM Also confirmed I have dead TC chip for sure, so need to order one for the last cooling channel 30-Apr-19 10:02 PM @Conmega I am a professional software developer and I prefer to use Sublime Text without any plugins... pretty much just like the color scheme and the ability to use multi-caret for editing 30-Apr-19 10:17 PM @Applied_Ion at work, all the software folks pretty much assume terrible code must have been written by EEs so, much different view than where you came from 30-Apr-19 10:50 PM That color scheme is selectable in almost any other professional IDE, and well most of them allow you to create your own color scheme. But yea I mean a lot of the professional editors like TI's IDE is just... Well nice... They spent a lot of money developing that thing and well, remember, they used to charge a LOT of money for licenses, which now because of other free editors, its also free. Which is wonderful for us. 30-Apr-19 10:50 PM But yea, I dunno I am speaking from my experiences and from experiences I have heard from people who have been in the industry since before IDEs existed heh... I take their knowledge above all else since they have practically tried everything and really knows whats best, but can sometimes really mean whats best for them of-course, different strokes for different folks 30-Apr-19 11:41 PM I mostly just care about slim RAM footprint 30-Apr-19 11:41 PM good text search, like regex (which most good text editors have), and multi-caret 30-Apr-19 11:41 PM I use VI often too though... IDEs much less frequently 30-Apr-19 11:56 PM Sure, I use vi too for a lot of my perl/python/etc scripting. But when your working with a chip with thousands of register names/etc/etc its nice to have autocompleteing of the bit name labeled like: this.is.a.bit.somewhere.out.on.the.chip.bit2 And a lot of the time the compilers that come with these IDEs are custom compilers that know way better how to get code compiled for their chip than something like GCC. And when you can get that compiler for free its generally good to go-ahead and use it. 30-Apr-19 11:56 PM I think the TI code composer studio has multi-caret support. It also has some nice other shortcuts and things. I mean a lot of this fancy editor functionally has basically trickled down from stuff that's been in payed software for years. 30-Apr-19 11:56 PM Small ram footprint is kinda just a pipedream for a large feature rich software anymore though. Its like getting a small simple FPGA dev software... That compiles fast on no resources... Right... These things are big and complex nowadays and you just can't get away with trying to process FPGA compilation on a small simple box with no ram... I mean I have a Windows 7 VM on my desktop with like 12 threads and 8 or 16 gigs of ram just because of Altera's FPGA software... Its a complex process to compile that stuff, and trust me they have that stuff optimized as best they can since some places rely on the compile time for compiling entire CPUs onto FPGAs for testing an architecture before spinning silicon... I work partially with that stuff at work... Its... Slow... 30-Apr-19 11:56 PM But ultimately, you can have a desktop with like 8 threads and 16 gigs of ram for a few hundred bucks anymore... Like hardware is CHEAP. We live in a utopia of compute power for the average consumer or even prosumer. 30-Apr-19 11:56 PM Like I mean you can get a quad-core Atom single board computer, with 2 gigs of ram and 16GB of eMMC for like 34 dollars now. Seriously this is a thing: https://dlidirect.com/products/atomic-pi We have way more compute power at our hands for dirt cheap than we ever have. 30-Apr-19 11:56 PM Anyway, I am sick and I am going to try and get some sleep tonight unlike I did last night. 01-May-19 01:02 AM well I /do/ happen to work in semiconductor validation, so I deal with insanely huge amounts of registers with nested hierarchies... so I'm familiar with the problem space 01-May-19 01:02 AM I still hate the idea of /having/ to buy better hardware because: lazy programmers; monetization and tracking 01-May-19 01:02 AM I have a 22 core, 40M cache, 128GB ECC RAM with 1080Ti GPU server sitting in my closet that mostly just plays videos on my TV and runs folding@home... 01-May-19 01:02 AM but my laptop is from 2011 and still runs great because I use linux and no snazzy graphics animations and other "modern" crap 01-May-19 01:02 AM I literally hang out with people that don't use javascript in their web browser, just because it sickens them to waste so much performance on basically janky aesthetics (and tracking) 01-May-19 01:02 AM also, x86 is a pretty terrible choice for anything having to do with real-time operations.... there's just too much latency between the CPU and the real-world pins 01-May-19 06:37 PM Been live tweeting updates for the first vacuum system test. 10^-5 torr in 30 minutes from cold start, now at about 7.2x10^-6 torr a little over 2 hours pumping. Foreline pressure stable at 29 millitorr, cooling system stable at 22C. 01-May-19 06:37 PM 1 year of work and I'm finally in the high vacuum game at home. System is actually operating as designed 01-May-19 06:37 PM Need to wire hv supplies, but I'm ready for thruster testing 01-May-19 06:37 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20190501_213938-931ED.jpg 01-May-19 06:41 PM Awesome!! 01-May-19 07:29 PM Final pressure dipped to about 5.8x10^-6 torr in 3 hours of pumping. I only need 10^-5 torr for PPT tests, so plenty of overhead and hit the target from worst case outgassing from new system start. Really happy the whole thing worked on the first go, honestly I'm shocked. 01-May-19 08:27 PM Now that I can record system temperature, environmental temp/humidity, and pumpdown curves, I can compare collected data from each run to qualify my system performance based on operational and environmental factors. This can be a very powerful tool for benchmarking and troubleshooting down the road. 02-May-19 01:11 AM I just impulsively spent a big chunk of money impulsively 02-May-19 01:11 AM Irresponsibly 02-May-19 01:11 AM But hey, nice shiny turbo 02-May-19 02:58 AM shiny! 02-May-19 06:50 AM Want some photos :) 02-May-19 06:56 AM Haven’t physically got it yet 02-May-19 07:07 AM I'm thinking about buying a new turbo myself 02-May-19 07:46 AM Wrong turbo @Treehouseman 02-May-19 07:46 AM I know your talking about a vehicular turbo for your Jetta and not a high vacuum turbo-molecular pump like I assume we are :P 02-May-19 07:50 AM It still moves air molecules! :P 02-May-19 07:50 AM #vntlivesmatter 02-May-19 07:56 AM The pressure difference is inverse to that of what is desired in this server though :P 02-May-19 08:02 AM I guess at least somewhat related I'll be rebuilding a vacuum pump, apparently you're supposed to do the vacuum pump rebuild on the Jetta at 200k 02-May-19 08:02 AM It's a little baby thing driven right off the camshaft 02-May-19 01:11 PM Joined the server. 02-May-19 01:22 PM o/ hello! 02-May-19 01:22 PM Hello! 02-May-19 01:23 PM Welcome mason, great that you could finally join! 02-May-19 01:23 PM Btw @Mason_Yu, @qualia is the one also looking to do a DPF. 02-May-19 01:24 PM Happy to find someone else who's interested in the same thing! 02-May-19 01:24 PM @Mason_Yu is more of the expert in this field, he has done a lot of impressive design work on his so far 02-May-19 01:24 PM Do I hear fusion? 02-May-19 01:24 PM :D yeah! I started working on a sort of high-vacuum fusor-like thing last year, but @Applied_Ion has since rekindled my long-standing interest in pulsed power and now I'm gently puzzling out the logistics of building a small (1.6kJ) mather-type focus device 02-May-19 01:27 PM I have a 300 uF 10 kV capacitor bank (15 kJ) for my plasma focus, design work is mostly finished and I'm machining parts for it right now. Are you mostly interested in the fusion neutron yield @qualia ? 02-May-19 01:27 PM do you have a website / blog @Mason_Yu ? 02-May-19 01:28 PM Not right now... Doing this stuff is taking up most of my time and I don't have a significant social media presence. I'm seriously considering starting one though after looking at what @Applied_Ion has done on his website 02-May-19 01:29 PM Mostly, yeah! I have a 25kV 5.14uF "bank" (it's two capacitors) . I am interested in the neutron yield for purposes of.. attempts at imaging, yeah; I'm also kind of generally interested in what options are available for fast diagnostics of plasma dynamics 02-May-19 01:29 PM I expect to do a lot of dry runs with hydrogen, though 02-May-19 01:29 PM and past a point if I get my fill of trying to do anything substantial with measly little blips of 10^6 neutrons or so, I'm likely to just stick with non-fusing fuels past using it as a diagnostic criteria 02-May-19 01:30 PM If you are interested in imaging the plasma you will likely need an intensified CCD camera, for fast x-ray diagnostics a PIN diode is the way to go. But for a plasma focus you can deduce a lot about the performance of the z-pinch by looking at the current trace through a Rogowski coil 02-May-19 01:33 PM a friend has offered access to their intensified camera for this purpose, and I had the idea of trying fast two-frame imaging using a pair of scientific cameras genlocked together, one through a delay line 02-May-19 01:33 PM it's a lot of experimental ideas; I am just a hobbyist, after all 02-May-19 01:33 PM Next step, I think, is to sit down with a resistive GV snowplow solver and plug some numbers in to get vague estimates of what to expect, given what design. I'd like to try and build some intuition around all this before I start machining expensive copper stock 02-May-19 01:35 PM Yeah, I'm trying to get my ICCD to work too, but it's very old and all the software for it is extremely outdated. For the first runs I'm planning to use filtered x-ray film behind a pin-hole camera 02-May-19 01:35 PM Try using the Lee Model code too 02-May-19 01:35 PM Super easy to use but you have to be aware of the assumptions made in the calculations 02-May-19 01:36 PM I'm in the market for a suitable ion chamber for this, too, since I'm led to believe they are generally rather more suitable for pulsed fields 02-May-19 01:36 PM nod 02-May-19 01:36 PM Also gosh I'm technically at work rn but I would love to pick this whole subject up later :D 02-May-19 01:36 PM Definitely let me know if you end up making a twitter, or something! I'm @profanegeometry 02-May-19 01:36 PM currently debugging a major leak in my main turbopump, as is tradition 02-May-19 01:39 PM Yeah! I have just wired up my turbo pump as well and I'm trying to figure out how to read my vacuum gauges with a STM32-F4 microcontroller 02-May-19 01:40 PM @Treehouseman diesel jetta, i have a 2003 02-May-19 01:40 PM ? 02-May-19 01:40 PM @Applied_Ion what sensor do you use for rough vac line? 02-May-19 01:40 PM @all can you reuse kf gaskets on rough vacuum lines? 02-May-19 01:41 PM the viton ones? yeah absolutely 02-May-19 01:41 PM i always give them and their mating surfaces a clean wipedown before reinstalling 02-May-19 01:41 PM and sometimes letting them sit out in the open to decompress is useful, 'cos i have a bad habit of cranking down my kf clamps and leaving funny indents in the gaskets 02-May-19 01:41 PM bad at working 02-May-19 01:43 PM @nmz787 I use a thermocouple gauge on the roughing line. However, the hpt100 also covers from roughing to high cav 02-May-19 01:43 PM Also yeah, kf are completely reusable, and meant to be reusable 02-May-19 01:43 PM but, barring weird and inadvisable trickery involving thickness gauges, any metal gaskets are single-use only 02-May-19 01:43 PM @qualia thanks 02-May-19 01:43 PM My foreline is all kf 02-May-19 01:43 PM same ^ 02-May-19 01:44 PM @Applied_Ion yeah hpt100 looks nice but expensive for rough levels 02-May-19 01:44 PM i use an mks 901p as a foreline gauge. it's kf16 and they're about $50 on ebay 02-May-19 01:44 PM and go from atmosphere to ~10^-5-ish 02-May-19 01:44 PM they're extremely featureful for what they are, tiny little dongle with a serial interface, gas compensation, can control up to three relays iirc 02-May-19 01:45 PM Oh cool, i have an mks something something 02-May-19 01:45 PM mks makes real good something somethings :D 02-May-19 01:46 PM G2g now 02-May-19 01:46 PM Ttyl 02-May-19 01:46 PM cya! 02-May-19 01:47 PM @nmz787 I got mine for $40 each on ebay. One like brand new, 2 pretty used, 1 broken 02-May-19 01:47 PM I wouldn't use it for rough levels, but it's nice to verify against roughing line 02-May-19 01:47 PM Yea I like the 901p, simple gauge to work with relatively 02-May-19 01:47 PM there is a LOT of features on it though so the manual looks pretty intimating for talking to it. 02-May-19 01:57 PM Looks like i have a 901 that i paid $50 for a year and a half ago 02-May-19 01:57 PM 901p 02-May-19 01:58 PM Yeah, 2003 jetta wagon tdi 03-May-19 04:04 AM TFW you need a vacuum chamber big enough to fit your space station inside https://twitter.com/lougrims/status/1120773701396586497?s=21 03-May-19 05:02 AM @a_quiet_scientist please read the pinned Message in #introductions_and_directory 03-May-19 12:40 PM So, I went back to check my simulation numbers and calculations I ran for stuff during my system design phase. Looks like my estimates were practically dead on. Estimated steady state average baffle temp with 15C ambient and cooling with full diff load was 21C. Actual measured temp was 22C with ambient conditions at 15-16C, with slightly higher cooling temp. Hand calculated final pressure for ideal outgassing numbers for very short pumping times was 3.8 x 10^-6 torr. Simulated pressure was 3 x 10^-6 torr. Actual pressure was 6 x 10^-6 torr, but outgassing rates are higher than ideal since I'm using all fresh materials and new oil. I'm also using a couple more viton orings than in the original simulation. With baking and pumping more I should be able to bottom out the 10^-6 range. Finally foreline goal with full diff pump load was estimated to 30 millitorr. Actual pressure was stable at 28 millitorr. +1 for engineering! 03-May-19 12:43 PM awesome! 03-May-19 12:43 PM when I calculate and measure something I'm happy if both results are in the same order of magnitude... 03-May-19 12:44 PM Honestly I never thought I would even be this close 03-May-19 12:44 PM I'm happy if i get a result at all :P 03-May-19 04:14 PM Joined the server. 03-May-19 09:48 PM <0xDBFB7#9254> @Applied_Ion holy crap, that's super impressive 03-May-19 09:48 PM <0xDBFB7#9254> How'd you hand-calculate the base pressure? 03-May-19 09:54 PM @0xDBFB7 thanks lol. Initially all of my estimates and simulations were meant to be rough guidelines, but it turned out closer than I was expecting. At least it helps validate the stuff I've posted so if people want to follow the process I have gone through for their own system its been experimentally verified. 03-May-19 09:54 PM Base pressure calculations was a real long process lol 03-May-19 09:54 PM I posted all of the calculations for each chamber I worked on, as well as a general calculation walkthrough tutorial on my website 03-May-19 09:54 PM for the propulsion chamber, all of the PDF calculations can be found on the main engineering page under "Engineering Design Calculations" 03-May-19 09:54 PM http://appliedionsystems.com/portfolio/micro-propulsion-testing-chamber/ 03-May-19 09:54 PM for the calculation walkthrough and explanation, its a long, multi-part blog series. First page of the design walkthrough can be found here: http://appliedionsystems.com/high-vacuum-system-example-design-walkthrough-01-introduction/ 03-May-19 10:03 PM <0xDBFB7#9254> Huh, I can't seem to access your website 03-May-19 10:04 PM Same, I was just on it now, but it seems like it went down briefly. Could be the host temporarily, I usually almost never have any down time. 03-May-19 10:05 PM <0xDBFB7#9254> Nvm got it sorry 03-May-19 10:05 PM yeah its back up lol 03-May-19 10:05 PM Been organizing the data more and reviewing it. I still need to add graphing functionality to monitor the flow-rate sensors for each loop, but its not too critical for now. Also need to add a simple amplifier circuit to boost the thermocouple gauge foreline sensor so the arduino can log it. Need to troubleshoot 2 thermocouple cooling channels that were acting up as well, I suspect its just the reader chips. I was able to get data for the diff pump though, in addition to the main coolant tanks (which are the most important readings). Looks like an average of about 3C temperature rise from the cooling inlet to cooling outlet on the diff pump for my given flow rate. I will hopefully get around to some thermal imaging of the system which should be pretty cool to see. 03-May-19 10:15 PM The full pumpdown graph, which I will post later, is also pretty cool to see looking at the phases of operation of the diff pump. When it first kicks on, pressure spikes up high, from 50 millitorr to 90, then starts to drop. At 10^-4 torr it plummets very rapidly as speed increases, then tapers off into the 10^-5 to 10^-6 torr range. 03-May-19 10:24 PM <0xDBFB7#9254> This is seriously badass, I have a lot of reading to do 04-May-19 02:52 AM moin 04-May-19 03:19 AM moin! 04-May-19 08:34 PM Here is the pumpdown data from the first pumpdown run. Pressure measured in the chamber through the test: 04-May-19 08:34 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Run_05-01-2019_-_Micro_Propulsion_Testing_-2FE41.jpg 04-May-19 08:34 PM After pressure reaches a critical point and diff pump speed starts to increase, pressure plummets very fast within minutes. Shot through the 10^-4 torr range like it wasn't even there lol 04-May-19 08:34 PM Also, I will be attempting first ignition tests of the first PPT tomorrow. Pumpdown starts 11am (-4 UTC) and I will be tweeting updates live as it progresses. Hopefully I will capture some video of it in action if it works, and release it after. 05-May-19 03:41 AM moin 05-May-19 03:53 AM Moin! 05-May-19 06:38 AM Checked and set hv and pulser supplies. Wired up thruster feedthrough. Got 1 of the 2 broken TC channels back, so I can look at peltier chiller output performance now. Other TC looks bad and will need to be rebuilt later. Should be a go for testing at this point! 05-May-19 06:47 AM Pumpdown will probably start a bit earlier than anticipated 05-May-19 07:28 AM Cooling system on, test has started! 05-May-19 07:51 AM excited pumpdown noises 05-May-19 09:12 AM Thruster test failed. There was arcing across the ignition board with each ignition pulse. Spacing may be too tight on this thruster for the connectors 05-May-19 09:12 AM Fortunately the small gridded thruster is about ready so I can swap those out while I examine the first thruster. 05-May-19 09:16 AM but nothing died? 05-May-19 09:22 AM Well, some discharges caused the arduino to reset and crash a bunch lol. Also the thyratron pulser needs a rectifier tube replacement. But I think the issue was the connector, not the actual thruster module itself. 05-May-19 09:22 AM The plug was discharging. I solve that, thruster should probably fire. 05-May-19 09:22 AM The gridded PPT should work though. Much closer electrode spacing, pure hardware, and no boards to fail across 05-May-19 11:55 AM @Applied_Ion congrats on getting to test fire! 05-May-19 12:14 PM @sigfig thanks lol, though the engine didn't fire. Breakdown in the pcb socket prevented succesful testing. 05-May-19 12:14 PM Another important lesson I did learn though. Save the pumpdown data before turning on hv supplies. I lost all the data when the arduino crashed the first time lol. 06-May-19 12:18 AM @Applied_Ion lol vacuum arcs do that. On one particular sem vacuum arcs are known for causing the computer to throw up garbage all over the place and needing a hard reset after that. Kinda a pita, but thankfully it's hv is set by an analog dial and not my the computer. 06-May-19 04:18 AM Yeah ik, I've dealt with shielding before for gun arcs on the linac gun. I tested the shielding enclosure for the computer by running an arduino inside since its so sensitive to crashing and firing a 90kv marx next to it for emp testing lol 06-May-19 06:14 AM Lol sounds like fun 06-May-19 06:14 AM You ran the Marx with the aurdrino right? 06-May-19 09:02 PM Lol no, just running a simple sketch and monitoring it to see if it crashed while firing. 07-May-19 07:15 AM How does Swagelok VCR work? It looks like you need to buy only premade weld stubs and weld them onto your tube? You can’t just use bulk tube and assemble the end connector and swage it like a normal Swagelok fitting? 07-May-19 07:15 AM No wonder the eBay VCR metering valves are relatively cheap 07-May-19 07:15 AM New Swagelok metering valves are upwards of A$200 each which is one expensive valve 07-May-19 07:17 AM I thought VCR works like swagelok, but with unisex connectors and you need a gasket? 07-May-19 08:32 AM New thruster is mounted, thyratron pulser fixed, and everything wired again. Will be attempting another pumpdown and ignition test tonight after work. Hopefully two is a charm lol 07-May-19 08:32 AM If this works and I proceed to lifetime testing, I will look to try and live streaming the actual first lifetime test of 10k shots at a later date. Never live streamed before though. 07-May-19 09:12 AM I have what might be a laughable request: does anybody know where I can find a JEOL 35C manual? They seem to be mighty rare 07-May-19 09:14 AM That's an @AdamMcCombs question :P 07-May-19 09:14 AM If anyone has any JEOL doc Adam would know 07-May-19 09:31 PM I just need to scan mine in... 07-May-19 10:29 PM So I get this black square “burn” or “shadow” thing that appears on my sample during SEM imaging. It’s not there at first and seems to only cover the scan area. Is that normal? I’m told it may be outgassing from the carbon tape 07-May-19 10:29 PM It's either charging or sample contamination 07-May-19 10:29 PM Basically electron beam induced deposition of hydrocarbons in the vacuum. Is it a TMP system or something else? 08-May-19 03:36 AM Moin! 08-May-19 04:27 AM Moin! 08-May-19 04:27 AM The sample is Au on a GaAs substrate - so charging shouldn’t be a problem although GaAs is relatively high resistivity compared to other semiconductors 08-May-19 04:27 AM The SEM is a FEI Nova FEG system. I think it is kept pretty free of contamination by our staff keeping the researchers / students under pretty tight oversight of what materials are allowed in 08-May-19 04:27 AM I have been told to keep the carbon tape to the absolute minimum though 08-May-19 04:27 AM Might use a little oxygen plasma or piranha on the sample after SEM 08-May-19 04:27 AM Not piranha actually, I think it eats GaAs 08-May-19 04:27 AM I’m not sure what types of pumps are in there - I’ve never seen it under the hood and I won’t be allowed to by the owners of this one I would guess TMP - it’s a modern-ish SEM 08-May-19 04:27 AM A NW63 protective turbo screen is like AUD400 08-May-19 06:22 AM @AdamMcCombs I felt bad about asking so much back then, so I was just going to ask the server, not knowing they would ask you 08-May-19 06:23 AM No problem. It's just my scanner is hella slow and I am going to have to run it one page at a time... I should be getting a new scanner soon ish. 08-May-19 06:24 AM Maybe Dave will vacation out there again and can make a project of the scanning so you're not stuck doing it for ten hours 08-May-19 06:24 AM If I get the scanner I want I should be pretty fast 08-May-19 06:24 AM I think our repairs are going well regardless though 08-May-19 06:25 AM Yeah it's not going to help very much 08-May-19 08:41 AM Joined the server. 08-May-19 08:51 AM Haha, playing with more than thermal cameras then @tmbinc 08-May-19 08:59 AM Heh, yes. Sad fact: I can't keep up with the number of projects that I start, but never finish. But I guess that's a common thing. 08-May-19 04:35 PM story of my life 08-May-19 04:35 PM also hi! o/ 08-May-19 05:08 PM Yup 08-May-19 05:08 PM At least I don't usually have a reason to be bored 09-May-19 05:43 AM not having a reason to be bored and not getting bored are very different things 09-May-19 06:06 AM What’s the minimum safe setup I need for a quick open atmosphere spinup of a TMP? Just like 10 seconds or whatever. No backing pump at this time and no reducer to close the ISO63 port, so both the main port and foreline will be open. A gentle spin and it spins smoothly. Do I need to physically restrain the pump? Do not want to wreck it - the second most expensive thing I own. 09-May-19 06:06 AM just make sure it can't fall over or anything 09-May-19 06:09 AM Reposting this from Twitter in case anyone has ideas - I want to standardise a JFET choice for experiments which is actually cheap and easily available in 2019 for charge-sensitive preamplifiers. I'm thinking maybe PF5102 or NSVJ3910SB3T1G (Yfs is higher and Ciss is lower but it's SMD) 09-May-19 06:09 AM I hate the idea of relying only on NOS eBay surplus 2SK152 or whatever 09-May-19 06:22 AM https://www.mouser.de/ProductDetail/106-2N6453 Those are the fets used in canberra HPGEs, if they're good enough for <2 keV FHWM it surely is good enough for everything else 09-May-19 06:22 AM don't know if it counts as cheap 09-May-19 02:45 PM @a_quiet_scientist i've spun mine up for quick 'does it work' tests just on a bench 09-May-19 02:45 PM don't move it while it's spinning at any kind of speed 09-May-19 02:45 PM and ideally cover the top of it with something solid but translucent to prevent it from sucking in 10,000,000,000,000 dust particles 09-May-19 02:45 PM i wouldn't even run for 10 seconds 09-May-19 02:45 PM you won't hit max speed with it if your controller is working properly and limiting draw current; it'll be way high in atmosphere since max continuous inlet pressures on TMPs are in the, like, 10^-4 range (speaking from my ext250 anyways) 09-May-19 02:45 PM orders a fistful of carbon composition 47M resistors, waits impatiently 09-May-19 02:50 PM Just turn it on and stick your finger in it 09-May-19 02:50 PM What's the worst that could happen 09-May-19 02:51 PM unfurls a very long scroll covered in dollar signs and medical bills 09-May-19 02:51 PM And blood 09-May-19 02:52 PM turbomachinery is an unforgiving domain 09-May-19 03:02 PM are there any low cost options for dry/oilless roughing pumps that can back a big turbo? diaphragm pumps seem to be a thing, but i don't know if there are any low-cost brands applicable for this kinda thing 09-May-19 03:02 PM most of 'em seem to have reeeally high base pressures 09-May-19 03:52 PM How big of a turbo? And how critical is an oil free pump? 09-May-19 03:52 PM Oil free tends to be on the expensive side. Diaphragm or scroll pumps, but they are costly. Not too many that I have seen on ebay, though I haven't specifically looked for them 09-May-19 04:01 PM Also not sure diaphragm is good for high load backing. Usually you see them on smaller turbo pumping stations 09-May-19 04:24 PM https://reprap.org/wiki/MetalicaRap Ambitious reprap 09-May-19 04:24 PM Moin! 10-May-19 02:11 AM My plan is to clean my SEM's molybdenum apertures by heating them. Instructions from the manual say: "Heavily contamined (sic!) apertures should be boiled several minutes in 20% NaOH, rinsed and then boiled in distilled water for approx. 5 minutes. then bring up aperture to bright read heat in vacuum (better than 5x10^-4, vacuum evaporator) on a strip of molybdenum sheet or in a molybdenum boat; avoid overheating because the aperture easily melts on molybdenum. Allow aperture to cool down well before ventilating the vacuum evaporator (danger of oxidation)." I have a Balzers MED 010 (sputter/coater) that can also be used for carbon evaporation coating; is that a suitable device for this purpose? It can generate the right vacuum and has a high current power supply (though I have no idea how much current I actually need to bring a molybdenum boat to that temperature).I think I don't have the proper holder for a boat, so I may have to improvise (and also the high current output is at the top (cover) of the chamber). I also have a couple of molybdenum boats (BALZERS BD 482 048-T) that I hope I can use. Any obvious holes or stupid ideas in my plot? 10-May-19 03:06 AM I think I'm doing it wrong(tm). The molybdenum boat nicely glows "bright red" but apparently the heat transfer to the aperture is not sufficient? 10-May-19 03:06 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/bf9f06dd-f83e-4b6a-abf6-0dcf631af672-74621.png 10-May-19 06:01 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190510_145539-8AFB1.jpg 10-May-19 06:01 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190510_145553-62115.jpg 10-May-19 06:01 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190510_145605-A968D.jpg 10-May-19 06:01 AM Got some more vacuum pumps :3 10-May-19 06:01 AM All appearently failed electrical inspection so chances are good the mechanics is still ok 10-May-19 06:01 AM The two membrane pumps are super nice, very similar with the one that came with my turbo pump stand 10-May-19 06:21 AM @tmbinc using a sputter coater evaporator may destroy the apuretures, vacuum is very poor and may permanently contaminate it. It's likely not above 10x-4 10-May-19 06:21 AM Unless it's turbo or diff pump it's not good enough 10-May-19 06:46 AM It’s turbo pump and I get it to 10^-4 before i start heating it up. 10-May-19 06:47 AM Ok nice. Honestly I would let it get further if it can before you start. Did it eventually heat up? 10-May-19 06:49 AM It takes ~a few minutes to get to 10^-4, the spec has a graph that shows it could in theory go to 10^-6 but in practice to 10^-5 in ~20-30 minutes 10-May-19 06:49 AM However the device is ~30 years old as well (came from the same place as the SEM) and likely hasn't seen sufficient service. At least oil was replaced apparently a few times 10-May-19 06:50 AM Have you replaced the rp oil? 10-May-19 06:51 AM The aperture didn't heat up sufficiently (and then I had to leave.... stupid real life obligations...) but I think it was not having good contact with the boat 10-May-19 06:51 AM I haven't replaced any oil yet (just checked that there is still oil) 10-May-19 06:51 AM But something is wrong with the MED 010 RP as it sometimes doesn't start. Powercycling a few times usually helps. 10-May-19 11:09 AM @Applied_Ion one major reason i'd like an oilless pump is that i am curious about differentially pumping a pair of chambers through a three way valve; roughing the chamber down to vacuum as needed, then to high vacuum on one side while another chamber (open to the other) stays at a potentially much higher pressure. i see this setup appear in a variety of cases and one instance of this was for very low energy collisional studies with a high vacuum drift/acceleration region leading into a (relatively) gas-dense target area 10-May-19 11:09 AM in that one example they'd used a roots pump with the inlet/outlet connected between the high/low sides, i thought it was kinda clever 10-May-19 11:09 AM another reason, aside from the usual annoying backstreaming fears, is that i plan to design a chamber as a a leak-tight assembly when closed off through a gate valve for process purposes, and then once i'm done getting up to mischief i'd like to be able to open the gate valve and draw out the process gas into a collection vessel for storage/analysis 10-May-19 11:09 AM trying to do this through a pool of grimy pump oil seems pointless 10-May-19 11:09 AM perhaps i could possibly do this even just using pressure differences to fill an evacuated chamber just before the gate valve, pumped down to (U)HV pressures, but the idea of being able to do gas recovery and recirculation seems novel and interesting 10-May-19 11:26 AM there is also just the simple fact that i've been making due with a terribly noisy and tremendously finicky bargain bin hvac pump of questionable long-term performance for so long now that i would really quite like to upgrade to something that will sate my needs for a long time coming.. but my desire for an oilless pump is also at odds with the fact that i definitely would like much higher pumping speeds for my large-ish chamber/turbo. @AdamMcCombs 's recommended the Edwards RV5 series a couple times now, iirc, and I'm still keeping tabs on fleabay for any of that series that show up of reasonable cost/shipping/condition 10-May-19 01:14 PM I sometimes take for granted the low cost availability of Welch duo seal pumps here in the US. They quietly just spin along. Kind of a soothing sound when running right. 10-May-19 01:15 PM Anyone have any good intro info on electrostatic vs electromagnet affecting ions vs electrons more/less? I am interested to read about trying to get a dualbeam FIB/SEM to have a colinear beam line. I was reading about bending ion paths recently due to mass-spec investigation... But haven't gotten around to googling for this idea. Seems like it would be a great boon to keeping the apertures for the ebeam clean, since FIB is pretty much self cleaning 10-May-19 01:23 PM @qualia yeah differential pumping can be tricky. Usually you need high pumping speed to compensate for the leak you introduce from the low side. It depends on the difference between the two sides too, and how high vacuum one side you want vs how low vacuum on the other. Gas recovery and recirculation through vacuum systems would be quite a challenge too 10-May-19 01:23 PM @Mason_Yu is looking to do a differentially pumped chamber for his DPF 10-May-19 01:23 PM @nmz787 what energy level, and what type of manipulation are you looking to do? 10-May-19 01:26 PM Both fib and sem run at 30kV normally 10-May-19 01:26 PM Wouldn't want to run both sources simultaneously 10-May-19 01:26 PM Was thinking a T shaped beam system, where either side of the top of the T is a source, and destination is the bottom of the T 10-May-19 01:34 PM So just something like a dipole bend? 10-May-19 01:34 PM Except it can enter from either side 10-May-19 01:37 PM Erhmm 10-May-19 01:37 PM I was thinking a 90 bend from each source, to merge into a common beamline 10-May-19 01:37 PM Where the lensing would be 10-May-19 01:37 PM I've heard that e beam apertures get dirty from oil redepositing and such, but with FIB this stuff is always being ablated away 10-May-19 01:37 PM So fibs don't really suffer as much performance degradation over time or with dirty conditions 10-May-19 01:48 PM Yeah 90 degree bending would be a dipole lol 10-May-19 01:48 PM Well, doesn't have to be 90 10-May-19 01:48 PM General bend 10-May-19 01:48 PM Depends on the space in your chamber 10-May-19 01:48 PM Electrostatic vs magnetic have different strengths and weaknesses 10-May-19 01:48 PM Depends on the application 10-May-19 01:48 PM How much space do you have to work with? 10-May-19 01:48 PM I'd say 90 degree would be better with magnetic usually 10-May-19 01:48 PM Bending though can introduce beam spreading and other changes that may need correction 10-May-19 02:54 PM Well I was thinking this would need to be a custom chamber 10-May-19 02:54 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190323_134324-CCA18.jpg 10-May-19 02:54 PM That's the current FIB chamber with gun at the top 10-May-19 03:10 PM nice 10-May-19 03:16 PM Pretty sweet, so that your personal system? 10-May-19 04:36 PM Fired up my SEM for the first time in a couple months. Tried out low vac mode for the first time! 10-May-19 06:35 PM https://twitter.com/FauthNiklas/status/1127024143248056320 10-May-19 06:35 PM I can haz microfocus xray :3 10-May-19 06:44 PM @niklas do you still have any of those POE xray sensors? 11-May-19 02:30 AM moin! 11-May-19 07:02 PM evenin! 12-May-19 03:13 PM Joined the server. 12-May-19 03:17 PM Welcome! 13-May-19 01:18 AM Moin! 13-May-19 03:06 AM Thank you!! 13-May-19 03:13 AM I'm seeing some impressive setups! 13-May-19 04:26 AM moin 13-May-19 05:41 AM Joined the server. 14-May-19 12:47 AM Moin! 14-May-19 02:37 AM moin 14-May-19 03:15 AM For a SEM, what's a typical a.) Wehnelt and b.) anode/top liner tube aperture size? I have found used ~1250um and ~500um apertures in the SEM supplies, but currently installed are 2x 1250um 14-May-19 08:05 AM @tmbinc There's no typical size, depends on the scope and if it was modified for something special. 15-May-19 07:29 AM @tmbinc what's the model of scope again? 15-May-19 08:12 AM Zeiss DSM 950 (almost same column as DSM 940, DSM 960) 15-May-19 08:12 AM https://dsm950.debugmo.de/page-161-6-2-1-3-3-0.html (username "dsm950", password "zeiss" ) has a diagram of the cathode, https://dsm950.debugmo.de/page-169-6-2-2-3-2-0.html has the anode, but I can't find specs for the aperture 15-May-19 08:12 AM (this was extracted from a huge, scanned, non-indexed PDF that Zeiss sold to me) 15-May-19 09:03 AM @Applied_Ion yeah it's in my garage :p 15-May-19 09:25 AM @tmbinc Does your scope have one of the interchangeable wehnelt tophats or something? 15-May-19 09:25 AM As far as what apertures to use the reason you may see something other than spec is using lab6 vs no lab6 and if they setup the wider apps to get more probe current for EDS 15-May-19 09:28 AM "interchangeable" as in "there are multiple to chose from"? I don't think so; I mean, I have to remove it to change the cathode of course. I think the SEM once had EDS but is was removed. It never had LaB6 as that requires a different configuration. So not unlikely that someone intentionally used a bigger aperture than required; equally likely though that someone just used the wrong aperture (especially because it's not documented) 15-May-19 09:29 AM Some scopes have the very center of the wehnelt setup as a consumable. 15-May-19 09:29 AM https://www.tedpella.com/apertures-and-filaments_html/aperture_tantalum.htm 15-May-19 09:29 AM Example 15-May-19 09:29 AM As if 60$ for a filament was not enough already 15-May-19 09:32 AM Yes - the center of the wehnelt is replaceable 15-May-19 09:32 AM It's basically a massive piece with an "aperture" (very similar to the aperture at the anode) that's replaceable 15-May-19 09:32 AM (I'll make some photos on Friday) 15-May-19 01:25 PM afternoon! 15-May-19 01:34 PM Heya 15-May-19 01:45 PM Joined the server. 15-May-19 02:04 PM Welcome @DarkOnion ! 15-May-19 08:49 PM Is there a minimum size that a sputter chamber needs to be? 16-May-19 12:41 AM as big as your biggest sample will be 16-May-19 01:07 AM or bigger if you want the whole sample coated with an uniformly film 16-May-19 05:48 AM moin! 16-May-19 06:23 AM Hello , I 'm looking for to purchase an used UHV vacuum chamber + Pumps & Gauge for my Quantum computing project with ion trap. Chamber need to have at least 4 viewports and 2 passthrough + Ionpump & Turbo pump + Gauge etc (10-10 to 10-11 torr objective). I need to have a 15cmx15cm*15cm space inside the vacuum chamber. Idelay, it will looks like the image below . Can you make me offer by DM message if you have such system to sell (i'm located in France) ? thanks 16-May-19 06:23 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/9k-EE211.png 16-May-19 07:23 AM That is going to be either a very expensive journey, or a somewhat less expensive and very very long time consuming journey! With that out of the way, a few questions to guide the conversation. Do you have access to a machine shop? Do you have any ultra high vacuum experience already? Do you have funding or are you self funding? Do you feel comfortable with EBay and other surplus goods sources. Past that it’s doable. If you are just looking to purchase something ready to go I first suggest finding something used that you can make work. If you have serious funding then there are many commercial sources for vacuum chambers, but if you were in that position my guess is you would not be asking here. 16-May-19 07:23 AM But let’s hope somebody here has something close available already. Good luck on your project. I always error on the side of build it yourself! 16-May-19 08:07 AM @Charles IMHO, it will be a very expensive AND long time consuming journey . I have access to a sort of HackerSpace with machine. I also have my own lab with a lot stuff... I have my own hackerspace at home ! I have no practical experience with UHV (as already mentioned in this forum before). But i learned the topic since several month . I 'm self funding. Ebay is fine for me. buying something ready is an option under study now (quotes received from several suppliers) but some prices are too expensive from my point of view and, I like to build things with" hacker style" so buying "second hand" equipment is a sort a religion for me (and it save my money !). 17-May-19 01:47 AM Moin! 17-May-19 01:54 AM moin 17-May-19 01:54 AM yeah you need an tmp and an igp which also acts as an gauge for low pressures 17-May-19 01:54 AM for higher pressures you need a pirani to get the point for starting tmp and later the bayard alpert gauge to get the point for fireing up the igp ( < 10^-6 mbar) 17-May-19 01:54 AM and after pre bakeout 17-May-19 01:54 AM used tmp are ok 17-May-19 01:54 AM used igp are mostly dead 17-May-19 01:54 AM as in to saturated/contaminated 17-May-19 01:54 AM so yeah the expensive parts are: fresh & big enough igp 17-May-19 01:54 AM and good valves 17-May-19 01:54 AM to isolate the chamber from the tmp when your bake out is complete, and you only have the igp running 17-May-19 01:54 AM also expensive: fancy substrate (for some laser wave lengths) and fancy coated viewports and not-so-bad leaking feedthroughs for optical fiber or electrical foo 17-May-19 01:54 AM the chamber itself should be polished or electropolished but thats not a must 17-May-19 01:54 AM depends by different factors 17-May-19 01:54 AM and you need to know what material you chamber has to be made of 17-May-19 01:54 AM SS is magnetic 17-May-19 01:54 AM Aluminium not but bakeout temp max is 120 deg celsius 17-May-19 01:54 AM quartz glas or sapphire is quite expensive 17-May-19 01:54 AM but perfect 17-May-19 01:54 AM but if SS or Al is sufficient it is not that expensive 17-May-19 06:45 AM Heya all 17-May-19 06:45 AM Err... Moin 17-May-19 07:56 AM I think your turbo pump then an ion pump idea is good. You will want a long long turbo pumping and bake out to get the contamination out the first time. -11 or -10 range is a big big goal. Everything from the turbo pump back must be metal on metal. No elastomer seals. Even ceramic feedthroughs are going to need to be verified leak free. Try to find somebody with a good leak detector with a small gas wand. Excellent cleaning procedures will be needed too. 18-May-19 02:10 AM you will absolutely have to do a 450+C bakeout to desorb hydrogen out of the metal, and everything else, and that will dictate a lot of your materials choices 18-May-19 02:10 AM for your particular application you may want to try and nail down some goals in terms of trapping times vs. chamber mean free path and collision/disturbance rates 18-May-19 02:46 AM I present to you 18-May-19 02:46 AM copper cf 18-May-19 02:46 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190518_111131-6369A.jpg 18-May-19 02:46 AM maybe it's one time use with ss rings :D 18-May-19 03:14 AM nice but kinda well fcked? 18-May-19 03:14 AM @qualia nah no need for 450 18-May-19 03:14 AM i would prebake the parts after cleaning in a clean vacuum oven at 300 deg celsius 18-May-19 03:14 AM a must for used parts of course 18-May-19 03:14 AM (cleaning) 18-May-19 03:14 AM oven vacuum at < 10^-4 mbar 18-May-19 07:23 AM Prebaking will help with volatiles and initial water vapor, but as soon as it's exposed to atmosphere for assembly it will start adsorbing on the surface again. It will definitely help make pumpdown in the high vacuum range must faster though. 450C isn't necessary, but higher temp helps with pumpdown times. To get to the upper UHV levels, baking during pumping is an absolute must, and you will be pumping for quite a while regardless. Past 10^-8 hydrogen is the dominant gas like @qualia mentioned as is the tough one to remove. Glow discharge cleaning with baking can help as well 18-May-19 08:53 AM yeah bakin with 120 is okayish 18-May-19 08:53 AM and a relative large igp comes handy 18-May-19 08:53 AM in system mounted 18-May-19 08:53 AM in the bakeout oven 300 max esp for Al 18-May-19 09:52 AM Hydrogen is especially a problem with copper. Actually at near red heat copper becomes pours to hydrogen and can be used as an admittance device in vacuum systems. 19-May-19 02:38 AM moin 20-May-19 01:46 AM PRINTED CIRCUIT BOARDS FOR ULTRA HIGH VACUUM ? What UHV compatible PCB providers or material for PCB (double face needed) you could advice to me (10-9 to 10-10 Torr is the objective). I See the the Rogers RO3003 ceramic-filled PTFE composite will be find. Any other suggestion ? 20-May-19 06:20 AM waves 20-May-19 06:20 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-DB656.jpg 20-May-19 06:20 AM There’s a LIGO technical note (you can google it) on PCB assembly for UHV environments, which describes the cleaning and solder protocol they use 20-May-19 07:00 AM thanks for the link to the LIGO technical note (already read before asking my question) it is here that i See that RO3003 ceramic-filled PTFE composite is comptatible 20-May-19 10:08 PM yeah ro3000 and ro3000 are ok 20-May-19 10:08 PM but you could also use ceramics as a substrate - but then its up to you how you depose the conductors (pvd, cvd, wet galvanics ...) of course 20-May-19 10:08 PM and Silicium wafers are a good substrate 20-May-19 10:08 PM ro4000 and ro3000 20-May-19 10:27 PM moin 20-May-19 10:31 PM moin! 20-May-19 10:31 PM Evening 20-May-19 10:52 PM It's always moin somewhere. 21-May-19 06:41 AM thanks to all for your answer about PCB assembly in UVH environment ! 21-May-19 09:28 AM Hello fellow vacuum hackers! We have a vacuum port on our SEM EDS dewar and we have no idea what this connector is, any ideas? 21-May-19 09:28 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/f0MxlbQeFbh_Gr1XC0EBYbGFu926NVXtqverAg6wVm-4CC5D.png 21-May-19 09:29 AM Need to repule vacuum on it? 21-May-19 09:29 AM yup! considering connecting directly to the INT chamber 21-May-19 09:29 AM but need to figure out wth that port is 21-May-19 09:33 AM iirc they have to be opened under vacuum 21-May-19 09:33 AM there's an adapter for it, a rotationary feedthrough and pumping port 21-May-19 09:49 AM oh hey it looks like one of these: http://burro.astr.cwru.edu/Schmidt/Schmidt_Manual/pumping_dewar.html 21-May-19 10:05 AM looks to be called an "operator" 21-May-19 10:06 AM yep, that's the thing 21-May-19 09:51 PM Joined the server. 21-May-19 11:24 PM Got to walk around a solar cell factory today 21-May-19 11:30 PM @sirus I have a friend at the llnl detector shop that might be able to loan one 22-May-19 12:02 AM moin 22-May-19 02:40 PM ended up fabricobbling this thing together 22-May-19 02:40 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/D7IxVz_VsAEwDJi-000A9.png 22-May-19 02:51 PM This gets uglier every time I work on it. 22-May-19 02:51 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190522_175050193-7C2D8.jpg 23-May-19 01:37 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190522_123417-87D77.jpg 23-May-19 01:37 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190522_123533-EFA56.jpg 23-May-19 01:37 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190522_123721-525F6.jpg 23-May-19 01:39 AM oh myy 23-May-19 01:39 AM Well I'm finally back home after what pretty much amounts to 5 weeks straight in the field. 23-May-19 01:39 AM Got some cool stuff done though 23-May-19 01:39 AM I think this is the first SEM I've seen that doesn't use CRTs 23-May-19 01:39 AM Did this cool SEM install 23-May-19 01:39 AM DAMN IT 23-May-19 01:39 AM Lol 23-May-19 01:39 AM Wait 23-May-19 01:39 AM It didn't work? 23-May-19 01:40 AM well the dyno downtime was fun while it lastet 23-May-19 01:40 AM ?cat 23-May-19 01:40 AM Found one! 23-May-19 01:40 AM ?dog 23-May-19 01:40 AM Found one! 23-May-19 01:41 AM Anyways 23-May-19 01:41 AM I got that scope to ~6nm resolution 23-May-19 01:41 AM Which for a thermionic tungsten instrument that's 25 years old is pretty good 23-May-19 01:42 AM congrats! 23-May-19 01:42 AM for finer resolution you'd need field emission? 23-May-19 01:43 AM Lab 6 can get you a bit further but yeah 23-May-19 01:44 AM LaB6 cathodes look like it's the crystal glued onto the a tungsten filament 23-May-19 01:45 AM Your not wrong 23-May-19 01:45 AM and the crystal can be ground sharp 23-May-19 01:45 AM Can be 23-May-19 01:45 AM so basically you want to get as close to a point source as possible? 23-May-19 01:46 AM You get better life with a very percisly ground flat bit 23-May-19 01:46 AM That's part of it 23-May-19 01:46 AM Energy spread also plays a bid deal 23-May-19 01:46 AM Cold feg is the best resolution, and recently it's getting closer to matching the stability of thermal assist feg 23-May-19 01:46 AM Thermal assist feg is less vacuum though which makes it cheaper 23-May-19 01:48 AM thermal assist feg? 23-May-19 01:48 AM so just a very fine hot top? 23-May-19 01:48 AM I'd say warm but yeah 23-May-19 01:48 AM Covered in zirconium 23-May-19 01:49 AM but why only warm? 23-May-19 01:49 AM (and by warm I mean only 1400c) 23-May-19 01:49 AM ahh, ok 23-May-19 01:49 AM iirc thermionic emission follows T^4? 23-May-19 01:49 AM ah, no, only T² 23-May-19 01:50 AM Gun pysics make it a bit different 23-May-19 01:50 AM It's the interaction with filament bias that changes it a bit 23-May-19 01:52 AM ah, right, external field counteracts the work function 23-May-19 01:52 AM Yup 23-May-19 01:52 AM So you hot your saturation point and that's it 23-May-19 01:52 AM I mean you can keep heating it up 23-May-19 01:53 AM ah, thanks for reminding me 23-May-19 01:53 AM But you just melt the poor thing at that point 23-May-19 01:53 AM what exactly is the saturation? 23-May-19 01:53 AM (talking about tungsten not field here) 23-May-19 01:53 AM The saturation curve is the relationship between filament heat and emmison current 23-May-19 01:55 AM yeah, but what's the mechanism there? 23-May-19 01:55 AM This is easier to explain with video give me a sec 23-May-19 01:55 AM looking at richardson's law I'd say current rises with temperature 23-May-19 01:55 AM Ironically using a tem 23-May-19 01:55 AM https://photos.app.goo.gl/6qfARPiAavKsMdDSA 23-May-19 01:55 AM Start at 35 seconds 23-May-19 02:00 AM I see... a lot of free space charge effects? 23-May-19 02:00 AM As you heat the filament the relationship between the work function flucuations and the tempurture of the filament the source of the electrons stars to change. In this caseni have the tem optics configured to project the focal plane of the filament onto the screen to see where the emmison is coming from 23-May-19 02:03 AM the work function is temperature dependant? 23-May-19 02:05 AM I'm saying that emmison is the relationship of the effective localized work function as determined by local free space charge, and as the temp changes you start to get emmison of of different parts of the filament due to minute surface imperfections 23-May-19 02:06 AM ahh, ok 23-May-19 02:06 AM Thanks! 23-May-19 02:07 AM Field emission is.. completely different 23-May-19 02:08 AM yeah, that's a topic for another time 23-May-19 02:08 AM maybe once I pass my QM class xD 23-May-19 02:08 AM Yeah 23-May-19 02:08 AM They are really cool though 23-May-19 02:09 AM badum-tss 23-May-19 02:09 AM Especially the vacuum stabilized cold feg 23-May-19 02:09 AM Sub NM resolution 23-May-19 02:09 AM Want 23-May-19 02:09 AM what's stopping you? 23-May-19 02:10 AM Just waiting for the right microscope 23-May-19 02:10 AM at this time can't you just call up jeol and ask for one? 23-May-19 02:10 AM There's a very, very specified one I want 23-May-19 02:10 AM I want the only one that has a snorkel lens and the gen 2 pre x vision analog computer 23-May-19 02:10 AM It's not a common configuration 23-May-19 02:10 AM Oh and the full dry pump config 23-May-19 02:10 AM I could get any old thermal feg pretty easy 23-May-19 02:10 AM But this really good cold feg... Bit harder 23-May-19 02:10 AM It gets .9nm at 30kv and 1.3 at 1kv 23-May-19 02:10 AM Which is pretty insane 23-May-19 02:14 AM this may be a dumb question 23-May-19 02:14 AM but what's in that range? 23-May-19 02:14 AM Hm 23-May-19 02:14 AM So that's a fwhm resolution 23-May-19 02:14 AM I'd assume it's an order of magnitude too big for intermolecular bonds and too small for bigger structures? 23-May-19 02:15 AM So having that allows me to get very good surface images of things as small as viruses 23-May-19 02:15 AM I'm trying to find a good size reference, but in addition to resolution the system has better lumosity and brightness 23-May-19 02:15 AM So you get less noise for a given spot size 23-May-19 02:19 AM what kind of currents are we talking? 23-May-19 02:20 AM -9 to -12 usually 23-May-19 02:21 AM oh 23-May-19 02:21 AM Yeah 23-May-19 02:21 AM so basically the base noise of a normal electrometer 23-May-19 02:21 AM -6 is considered a lot for an electron microscope 23-May-19 02:21 AM My sem I'm at -9 or 10 for low mag images, and -11 for high 23-May-19 02:27 AM wow 23-May-19 02:27 AM as I said, noise 23-May-19 02:27 AM well, gotta go, @george is here ^^ 23-May-19 02:27 AM Night/morning! 23-May-19 02:28 AM neither, 1130 am 23-May-19 06:00 AM ^^ 23-May-19 09:40 AM Well blueboy stabilized at 1.43Torr, which is not 10mTorr. 23-May-19 09:40 AM Now to put a real gasket on the bell jar, that we just got in the mail yesterday 23-May-19 09:40 AM Also the leak rate is about 40 seconds per Torr 23-May-19 09:40 AM I feel like in the vacuum hackers community I'm in the corner eating crayons 23-May-19 09:51 AM you and me both bud, except I'm probably in the corner munching on viton 23-May-19 09:51 AM since I am blowing money and crayons are too cheap for me I guess 23-May-19 09:51 AM lol 23-May-19 09:51 AM we all can't know everything :) 23-May-19 09:51 AM though we can all learn! 23-May-19 03:38 PM afternoon! 23-May-19 05:24 PM You’ve got to start somewhere - everybody does and that’s okay. 23-May-19 05:24 PM People like Hull might bang on about “the wrong way” to do it - but don’t worry about them. A bell jar is fine for a low vacuum application, just be mindful of the pressure and temperature that it can withstand. 23-May-19 05:44 PM I mean an atmosphere is an atmosphere, and it's all room temp 23-May-19 05:44 PM Also, I'm putting my homemade passthrough out of it's misery lol 23-May-19 07:41 PM so spent way too much money at auction on high vacuum stuff yayyy 23-May-19 08:14 PM yeah that's a mood 23-May-19 08:14 PM i have a huge pile of fittings and trimmings en route to hook up my alpha spec properly 23-May-19 08:14 PM aaaand i might have a new rotary vane pump en route soon >.> 23-May-19 08:15 PM nice 23-May-19 08:15 PM whatdja get? 23-May-19 08:15 PM I have... a pallets worth of rotary vanes :) 23-May-19 08:15 PM and a pallet of turbos... 23-May-19 08:15 PM oh wow 23-May-19 08:15 PM https://www.go-dove.com/shared/auction/images/photos/96387/96386313.jpg 23-May-19 08:15 PM uhm 23-May-19 08:15 PM yea 23-May-19 08:15 PM https://www.go-dove.com/shared/auction/images/photos/96164/gl_large_thumb/96163886_gl_large_thumb.jpg 23-May-19 08:15 PM few other smaller lots of Leybold rotary vanes too 23-May-19 08:15 PM smaller and larger 23-May-19 08:15 PM two BIG oxygen rated pumps 23-May-19 08:15 PM hehehe 23-May-19 08:16 PM wow 23-May-19 08:16 PM I spent... a LOT... 23-May-19 08:16 PM >_> 23-May-19 08:16 PM but it was all great deals 23-May-19 08:16 PM this will mostly be for person build up of processes and stuff but also some re-sale and stuff 23-May-19 08:16 PM like if someone needs a custom chamber for something I can build out a process chamber for them 23-May-19 08:16 PM I have enough parts at this point 23-May-19 08:16 PM I did get some beautiful evaporation source furnaces 23-May-19 08:16 PM so I will have some heads and PSUs for that 23-May-19 08:17 PM and here i'm nervously wondering if i can justify $150 for a single leybold trivac d8c 23-May-19 08:17 PM oh neat, like resistive heating evap? 23-May-19 08:17 PM or something weirder 23-May-19 08:21 PM yea 23-May-19 08:21 PM https://www.go-dove.com/shared/auction/images/photos/96387/96386268.jpg 23-May-19 08:21 PM I got: $50 - 1x D8A $100 - 5x D4A $50 - 2x D2A $50 - 2x D16AC (corrosive/oxygen rated pumps) 23-May-19 08:21 PM those prices are for the lots 23-May-19 08:21 PM not per 23-May-19 08:21 PM I mean even if they all need rebuilds... 23-May-19 08:21 PM the rebuild kits are 200-300 a pop 23-May-19 08:21 PM which still makes them uber cheap pumps 23-May-19 08:21 PM I will definitely not need them all so I will be happy to resell some after I go through them :) 23-May-19 08:26 PM oh wow 23-May-19 08:26 PM i wonder if rebuilding an oxygen-rated pump requires any particular additional care & precaution 23-May-19 08:26 PM besides 'wear gloves' i guess 23-May-19 08:29 PM not really its just the materials used 23-May-19 08:29 PM and the oil used 23-May-19 08:29 PM major rebuild kit is actually reasonable for that D16AC 23-May-19 08:29 PM $245 23-May-19 08:31 PM wow, nice 23-May-19 08:41 PM so yea if your looking to buy a pump, especially if you can get by with a D4A which for any small chamber like a single 6" conflat T sized chamber or something, you'd probably be fine with, I will totally sell you one for a reasonable price 23-May-19 08:41 PM shipping is just going to be the fun thing 23-May-19 08:46 PM are they all 115V/60Hz 1ph motors? 23-May-19 08:47 PM I believe so, I guess I'll find out but they gotta be single phase, maybe 240 but too big to be 3 phase 23-May-19 08:47 PM ussually the 3 phase ones are tiny motors compared to the pumps 23-May-19 08:51 PM makes sense 23-May-19 08:51 PM we'll see how my auction goes; i am moderately interested in a D16AC 23-May-19 08:52 PM we might be-able to work that out 23-May-19 08:52 PM I really just need to keep one for my purposes 23-May-19 08:52 PM that was one I was really interested in... 23-May-19 08:53 PM figures :3 23-May-19 08:54 PM :P 24-May-19 08:31 AM I got a chamber from the auction as well, along with two turbopumps and other small parts 24-May-19 08:31 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/96164533-E25FF.png 24-May-19 08:31 AM Are you planning to go down to NJ to pick up the stuff you got @Conmega? 24-May-19 09:10 AM yea... Also oops had no idea you were bidding on that chamber..... 24-May-19 09:10 AM Had no idea how many people here were actually bidding on stuff I just know Adam DMed me a link like the day before the last lots were ending 24-May-19 12:57 PM hah 24-May-19 12:57 PM Just like when there was a qualcomm auction in Oulu here 24-May-19 12:57 PM former Nokia modem division 24-May-19 12:57 PM sooooo much testgear 24-May-19 12:57 PM Folks on #elektroniikka had to co-ordinate that they did not bid on the same stuff. 24-May-19 12:57 PM And old farts paid 500eur/pcs for ancient "200MHz" 250msps HP scopes 24-May-19 12:57 PM while folks paid 70eur for 10-2700MHz spectrum analyzers 24-May-19 01:03 PM CRTU-RU, yeah I've bought like 12 of them. 24-May-19 01:03 PM for an average cost of ~200 EUR including shipping and fees etc. 24-May-19 01:12 PM Lol 24-May-19 01:12 PM Yeah 24-May-19 01:12 PM I have a CRTU-G at my desk atm 24-May-19 01:12 PM my CMU200 is out on a loan 24-May-19 01:12 PM Then there's the old nokia stuff from Salo 24-May-19 01:12 PM where they had manufacturing 24-May-19 01:12 PM but EQT bought ALL the factory parts 24-May-19 01:12 PM they still have like pallet loads of CRTU-RU and CMU200, but they want 450eur/pcs VAT0% for them. 24-May-19 01:12 PM (CRTU-G = CRTU-RU, but can run GSM/GPRS signaling without CRTU-PU) 24-May-19 01:34 PM I've spent some time scraping all the GSM test cases I could find from the various harddrives, so in theory I could run an open source GSM firmware through pre-certification. (In practice, I lack the GSM skills to fix the numerous non-conformities that will appear) 24-May-19 01:34 PM Back to vacuum - I figured out I need to improve my setup to bake the molybdenum apertures. At the minimum, I need better molybdenum boats, but also I need to cool the evaporator better. So instead I followed the alternative approach of bathing them (=final apertures, spray apertures) in hot 20% NaOH, then rinsing a few times in ultrasonic bath. It's not perfect yet but I think SEM resolution significantly improved. (I still want to do the vacuum baking, but I don't want to risk killing the apertures due to oxidation should the chamber vent accidentally) Or maybe I should just buy replacement apertures. Is there anything special to consider on top of "3mm diameter, 40um hole" (for the smallest final aperture)? 24-May-19 01:42 PM @tmbinc Heh yeah, especially when osmocomBB is mostly non-conformities 24-May-19 01:42 PM and FreeCalypso is abandonware texas instruments code 24-May-19 01:43 PM I only tried OsmocomBB. And while it's nicely written, everything in GSM is just so ... different... from what I'm used to work with. (I clearly don't have the telco background) 24-May-19 01:44 PM Even then the L1/phy stuff is different from most telco stuff. There's always open DSP coder positions at Nokia for a reason 24-May-19 11:56 PM can AFM be measured such as through the concept of STM ? ie, the ref I see for AFM is a laser, but the cantilever is still on a piezo.. can't you use that piezo + tunneling effects as a distance meter? 24-May-19 11:56 PM or I may be missing some concepts, just simply that came through my head 24-May-19 11:56 PM the aim here would be to measure surface "finish"/roughness 25-May-19 01:27 PM @tmbinc no not really. Ted Pella carries 3mm apuretures for about 70$ a piece. The small ones cost a bit more depending on the size. 25-May-19 03:18 PM or maybe my question was more so: what other methods are there for measuring AFM? 25-May-19 03:56 PM looks like a simple quartz tuning fork with a probe can be used.. and basically another piezo for the Z will adjust and be the input for the distance factor 25-May-19 06:55 PM Joined the server. 25-May-19 09:20 PM @Conmega , Hi new to the world of vaccum. Wanted to get my first vaccum pump for sputtering and maybe a diy vaccum tube experiments. Saw your post about buying and salvaging “D4A” & “D8A”. Can you give me some info about them. And what is a good website to get some build information/showcase 25-May-19 10:24 PM Joined the server. 26-May-19 06:13 AM Hey @mradi those are just general rotary vane pumps, people here will commonly call them roughing pumps since for most applications we do, we want a higher vacuum than can be achieved with just this pump alone, so this "roughs" the chamber down to anywhere from 1x10^-3 to 1x10^-4 Torr then you'll use some other pump technology like a Turbomolecular Pump or Diffusion pump to get much lower with the roughing pump backing either of those pumps since they just grab molecules and compress them effectively, you still need to remove that higher pressure area and thats what the roughing pump does. For your work I'd assume you just need a roughing pump. So you can look out for Alcatel/Edwards/Leybold/etc They are just rotary vane pumps. The important thing about getting a used rotary vane pump is understanding it MIGHT need a rebuild unless the seller tested it thoroughly for you to ensure it still pumps well. Rebuild kits are about 200-300 bucks depending on the pump. You can search the name and model of a pump and generally find good info on them. For example here is a D4a specs from this site after searching "Leybold D4a" https://www.idealvac.com/Leybold-D4-D4A-Trivac-Rotary-Vane-Dual-Stage-Mechanical-Vacuum-Pump-Rebuilt-Refurbished/pp/P10356 So when finding a roughing pump to buy my recommendation is this. Search it, can you find good general info on the pump? If YES continue, if NO probably don't want to buy the pump but go on to step 2. Search for " Rebuild kit" Can you find a rebuild kit available from the companies like Duniway/etc? If YES the pump could be a good candidate to get and have as a long term service pump for your applications. If NO be aware that you may be stuck with a pump that needs rebuild at some point and not able to rebuild it, in which case you will have to get a new pump. 26-May-19 06:13 AM That's my general knowledge of pumps so far, there are other rules and considerations, like for pumping oxygen and other flammable/corrosive gasses you need a pump rated for that with the RIGHT pump oil otherwise you will create a BOMB!!! And some pumps have nicer features than others, like suckback prevention, which prevents oil from being sucked back up the roughing line tube when you shut it off with a vacuum. Most general Edwards/Alcatel/etc pumps do have this, but its a good idea to check, if it doesn't have this then all you need to do is open the roughing pump to atmosphere before powering it off. 26-May-19 06:13 AM Most people feel the Edwards RV line of pumps like the RV5/8/12/etc are the best designed pumps out there. But they go pretty expensive and their rebuild kits are COMPLEX. So I wouldn't say its a good starting place for some people. 26-May-19 06:13 AM Anyway, I have some stuff I need to be distracted by for awhile, let me know if you have any other questions and I'll try to get back to you in a few hours. 26-May-19 06:20 AM @Conmega I am at the research phase, I have been reading about vaccums, getters and high vaccum pumps. All the links in the resources section. Seems like I will have a vaccum in my home soon. Excited. I will look at my options when I am buying and post here to get some feedback. But in the mean time I will see what I can get. I thought of a starting budget of ~300 for a pump. Thanks again for your answer, I would have overlooked the maintenance part for sure. Glad I asked 26-May-19 06:20 AM @Conmega , also What would you recommend a good starting price would be, if 300 is just the rebuild kit. ~ 1000 USD 26-May-19 06:47 AM Uhm, I'd expect to pay anywhere around 50-100 bucks for a reasonable sized unknown condition pump... One working and in decent shape which doesn't need immediate rebuild maybe 150-250 depending on the pump. The problem is shipping since you could get one for 100 bucks used but then have to pay 50-75 buck for shipping. 26-May-19 06:47 AM So your budget of $300 for a roughing pump is like right on target for a pump ready to go or even after rebuild costs. 26-May-19 06:47 AM Now this is assuming you do the work rebuilding yourself. If you want to pay someone to do the rebuild well it depends on what they charge for the service/etc. 26-May-19 06:47 AM I'll probably be trying to sell rebuilt pumps for like 300 bucks or so to other hobbyists depending on the rebuild kit cost. Basically enough for me to justify the time and the cost of the rebuild kit. But shipping will the other other thing to consider as that could quickly add up. Oh also consider roughing pump oil which you have to change every now and then to keep your pump running good and for the longevity of the pump parts so you can keep your rebuild going as long as you can. That's like LDS vacuum has their roughing pump oil which is like 38 bucks a gallon and a standard roughing pump takes about quarter to a 1/3rd of a gallon somewhere in there 26-May-19 06:47 AM So if your only managing one roughing pump ordering by the gallon is generally the most cost effective, but if you have a small fleet may consider 5 gallon pails :) 26-May-19 08:24 AM Def buy from LDS. Support my local economy 26-May-19 10:31 AM Thanks! I am happy to hear that, around 300 is good. A little above will do. I rather start with know working good than, fix something to unknown state condition and scratch my head for days/weeks 26-May-19 10:40 AM The regulars here know by now that I am not one for fusors (unless they are pulsed). However, on that note, I was curious to see if anyone here who is working on or interested in fusors has considered operating one with gas puff injection synchronized to a high intensity pulse? Similar to gas puff injectors for high power DPFs, z-pinches, or standard ion diodes for fusion. The fusor is in fact a type of ion diode, but I don't believe I have seen any papers on the operation of one like more conventional fusion diodes with synchronized gas puff. For this mode of operation, I'm also talking about single shot - the pulse power supply capable of delivering many thousands of amps at tens to over 100kV. Fairly typical specs from a pulsed power point of view, but applied to the fusor with a synchronized gas puff. The inner grid would probably need to be modified from the conventional wire topology to a more robust version to withstand the intense pulse. I know @GigaSquirrel and @qualia have interest or worked on a fusor as well as pulsed systems in general. Any thoughts on this mode of operation? 26-May-19 10:43 AM I don't think the farnsworth fusor is the best geometry for pulsed stuff 26-May-19 10:43 AM pulsed I'd go with pinch, BOT or maybe even BOB 26-May-19 10:43 AM I am in fact looking into the possibility of injecting a gas puff in the central pinch column of a plasma focus to enhance pinch density 26-May-19 10:43 AM It is not trivial though, the yield enhancement is most likely going to be offset by energy lost to ionizing the gas and also loss in compression ratio 26-May-19 10:43 AM I agree that the Farnsworth design is likely not the most optimal for incorporating a gas puff 26-May-19 10:46 AM I think it could work well modified as a pulsed spherical ion diode. I have seen designs for cylindrical fusion diodes and some other much more radical geometries. Gas puff could easily be delivered at the central electrode through a hollow stalk for injection 26-May-19 10:46 AM Actually, a cylindrical pulsed diode would be easier and cheaper than spherical in a standard conflat 26-May-19 10:46 AM Though I guess at that point it may be more of a classic fusion diode than a typical fusor lol 26-May-19 10:49 AM Exactly 26-May-19 10:49 AM If pre-ionization in the form of a plasma injector can be added, it might even be more interesting 26-May-19 10:49 AM Sounds like it might not be too hard to build neither. 26-May-19 10:50 AM That shouldn't be too hard to make a plasma injector. 26-May-19 10:51 AM Would space charge effects limit the peak current though? 26-May-19 10:51 AM So we take a standard fusor. Replace the ion guns with a plasma injector. Replace gas delivery with a gas puff. And replace the standard supply with a high peak power pulsed supply 26-May-19 10:51 AM Depends how it is designed 26-May-19 10:51 AM Historically fusion diodes have reached MA level currents 26-May-19 10:51 AM I think though this could be quite an interesting and radical experiment to try with the fusor 26-May-19 10:53 AM Again I don't think we should call it a fusor at that point... Maybe call it at least a pulsed fusor 26-May-19 10:53 AM Yeah it wouldn't be a standard fusor anymore. Absolutely a pulsed one lol 26-May-19 10:55 AM It would take quite a bit of analysis to figure out the pulsed power requirement and electrode geometry/design. But I am open for an entirely empirical approach too 26-May-19 10:56 AM Though to be fair, a fusor is just one type of ion diode. It is always operated as a dc diode, but in physics pulsed diodes reign supreme 26-May-19 10:56 AM Something to do with the new chamber and the 35 kV caps I have lying around maybe? 26-May-19 10:57 AM Lol something to think about for the fusor people here at least 26-May-19 10:57 AM Just thinking about it this morning, I'm just surprised I haven't seen anyone try to operate one on a more intense pulse like classic ion diodes. 26-May-19 10:57 AM Not from the terms of break even or anything, but from optimizing neutron yields in a fusor type diode topology to improve over more classical dc driven designs. 26-May-19 10:57 AM Since dc is grossly limited in voltage and current that can be generated for equivalent cost and power input to a pulsed system. 26-May-19 10:57 AM For reference, George Miley did release a paper decades ago on a much lower power pulsed fusor that just used a simple hydrogen thyratron switching a PFN through a pulse transformer into a standard fusor. Only 17A peak, 50kV, 100uS, 10 Hz, creating production of up to 8x10^8 n/s with just D-D 26-May-19 10:57 AM Those pulse parameters are trivial to achieve, and the neutron rates are exceptionally high for such low pulse inputs 26-May-19 10:57 AM Why not take it up a notch? 26-May-19 11:20 AM Also note that in his setup, only a 5kv supply was needed, since the output pulse was boosted by a 1:10 pulse transformer. 26-May-19 11:21 AM I'm pretty sure we're looking at the same paper? "High-Current Pulsed Operation of an IEC Device"? 26-May-19 11:22 AM Yeah lol, I think you should have it 26-May-19 11:22 AM He never mentions the yield per shot though 26-May-19 11:22 AM There are many more ways to get an intense neutron source, it's just that the high production rate only lasts microseconds at best 26-May-19 11:24 AM Neutron rate is per second since it operates at 10hz 26-May-19 11:24 AM Average power is still the same as a dc system, but with higher yields per second due to peak power increase 26-May-19 11:24 AM While each burst is only microseconds, operating at high rep rates essentially makes it a continous output from activation standpoint 26-May-19 11:24 AM Same thing for other commercial sources and linacs 26-May-19 11:24 AM Almost all higher yield devices operate pulsed at a certain rep rate to increase average neutron yields per second 26-May-19 11:27 AM I do have to say that the I^2 or even I^3 neutron scaling law is not bad at all 26-May-19 11:27 AM Though I'm not quite sure if it can be extended to the kA or even MA region 26-May-19 11:28 AM Now a single shot device like I described, maybe not as useful, but would be interesting to see just how many neutrons can be pumped out in a single shot for a modified high intensity pulsed fusor 26-May-19 11:28 AM I think kA would be do able 26-May-19 11:28 AM MA, that would require a massive facility lol 26-May-19 11:28 AM Going back to the pulsed fusor Miley describes, the point is it is a very simple system with very low input voltages, and can yield such higher orders of magnitude n/s than any DC system with equivalent input power. I think if people want to try breaking into like the 10^7 n/s and above range for small fusors, like in a 2.75" cross, this is the way to go. Xray transformers or glassman supplies just can't ever reach these currents. 26-May-19 04:32 PM Just ran the first ignition test for the new thruster and have finally confirmed repeated successful ignitions! 26-May-19 07:48 PM Joined the server. 27-May-19 03:19 AM skims the pulsed fusor paper above 27-May-19 03:19 AM i was scrolled up and didn't see all the conversation that'd happened earlier, and started writing out a long thing about how pulsing a fusor seems like it'd circumvent the inertial property that makes them work, but apparently that thing was pulsed 100us at a time which is waay longer of a time period than i was considering, lol 27-May-19 03:38 AM i wish i knew my way around MHD well enough to be able to make meaningful assertions about the actual behavior of a fusor. i know it's a profoundly lossy device in its classical form but i really would like to see the charged species distribution (i know it's very non-neutral), collisional parameters at the wall / grids, per-particle orbits as they sweep through the acceleration gradients, etc 27-May-19 03:38 AM any given plasma physics question seems to have at least a couple really hairy unsolved optimization problems hiding in it 27-May-19 03:38 AM glossing over tokamak ICRH lit has definitely piqued my interest in a weird way about all this and i could definitely idly fantasize about, like, a precisely-optimized grid geometry coupled to well-modeled deuteron gyrokinetics in a high-rep-rate (read: RF) pulsed E-field 27-May-19 03:38 AM on a hobbyist scale if you tuned your power delivery transmission line just so you could maybe get it to ring at whatever that frequency ought to be for your system 27-May-19 03:38 AM shrug 27-May-19 01:46 PM Joined the server. 27-May-19 01:52 PM Welcome! 27-May-19 02:01 PM Thanks Lukas for inviting me 27-May-19 02:02 PM ohai @chucrut, or should i call you - Sauerkraut? 27-May-19 02:03 PM Chucrut is for sandwiches 27-May-19 02:03 PM Pan in spanish is bread 27-May-19 02:03 PM So, everything is connected 27-May-19 02:06 PM can I post a screenshot of your latest post in the fusor forum? @chucrut 27-May-19 02:07 PM Yes please 27-May-19 02:07 PM A moderator deleted my post 27-May-19 02:07 PM i can't imagine why... 27-May-19 02:07 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/photo_2019-05-27_23-07-12-9A735.jpg 27-May-19 02:07 PM the thread was going so well 27-May-19 02:15 PM I want to make a high power electron gun 27-May-19 02:15 PM Now im thinking how to make the power supply 27-May-19 02:15 PM I need high NEGATIVE voltage. Like -20kv 27-May-19 02:16 PM 20 kV is nothing 27-May-19 02:16 PM xD 27-May-19 02:16 PM I've got a -30 kV 100 mA supply right here! 27-May-19 02:16 PM I have many high POSITIVE voltage power supplies here 27-May-19 02:16 PM But i think they cant be used. Or im wrong? 27-May-19 02:16 PM You have a homemade power supply Lukas? 27-May-19 02:17 PM when it comes to electron guns go talk to @AdamMcCombs , he knows everything in that topic 27-May-19 02:17 PM nah, mine's bought 27-May-19 02:17 PM got it for a price where DIY would make no sense 27-May-19 02:17 PM Yes, you are right 27-May-19 02:17 PM @AdamMcCombs please come here a minute 27-May-19 02:17 PM I need to talk seriously with you 27-May-19 02:17 PM I speak spanish by the way 27-May-19 02:21 PM funny, I thought you were speaking english right now 27-May-19 02:22 PM Adam is like the boss here? 27-May-19 02:22 PM I should measure my words 27-May-19 02:22 PM he's the main admin 27-May-19 02:22 PM Okay. I will be a decent person 27-May-19 02:23 PM and don't use quotes, they use up too much storage! 27-May-19 02:23 PM Yes. Quotes eats too much ram memory 27-May-19 02:23 PM ram memory, the contents of which are displayed on the lcd display? 27-May-19 02:24 PM Yes, I need to download more ram 27-May-19 02:24 PM xD 27-May-19 02:25 PM Do you sell your power supply Lukas? 27-May-19 02:26 PM nope, sorry ^^ 27-May-19 02:27 PM Dont worry. I will make my own power supply 27-May-19 02:27 PM I still need it for my fusor 27-May-19 02:27 PM -31kv 27-May-19 02:27 PM damn 27-May-19 03:10 PM @chucrut how high power gun you looking to make? 27-May-19 03:10 PM I've got a 300MW beam gun in the works 27-May-19 03:12 PM -30kv, 100ma aprox 27-May-19 03:12 PM (Lukas, im looking at you) 27-May-19 03:14 PM Still pretty low power class lol (all things considered in the realm of electron guns). What's it for? 27-May-19 03:14 PM And yes, despite what everyone was saying (I have followed the forum topic myself), you can make a positive power supply electron gun. Just some extra things to consider 27-May-19 03:14 PM It's not nearly as common, but it's still do able 27-May-19 03:28 PM Someone was also asking about this on the fusor fb group, I'm assuming that was you as well? (I'm Michael btw, who was answering questions on that post in case it was you.) 27-May-19 03:49 PM Hi Michael 27-May-19 03:49 PM Yes, I was asking in the fb group too 27-May-19 03:49 PM I made some simulations for the electron gun with positive voltage 27-May-19 03:49 PM The electrons return to the anode after exit 27-May-19 03:50 PM What software are you using? 27-May-19 03:51 PM CPO 27-May-19 03:51 PM What's it stand for? 27-May-19 03:51 PM electronoptics.com 27-May-19 03:51 PM The software is easy to use 27-May-19 03:51 PM Haven't heard of it before lol 27-May-19 03:51 PM Free? 27-May-19 03:52 PM Not free, but the evaluation version is enough 27-May-19 03:52 PM The ground voltage of the components after the anode repel the electrons 27-May-19 03:52 PM I mean, the anode at POSITIVE voltage makes the electrons return 27-May-19 03:52 PM I think the electronic part for a POSITIVE gun is more simple 27-May-19 03:52 PM I dont understand why is not common 27-May-19 05:24 PM Can you shape the anode and space it in a way that "shields" the electrons from seeing the field as it transitions into the grounded chamber, and add optics to focus the beam to prevent beam blow-up? 27-May-19 05:24 PM I think in general any system that uses an ebeam commercially or in research is already expensive enough that adding a high voltage isolation transformer for the filament ends up being easier than dealing with injection issues like this, which makes gun design more complicated. Can't get everything for free lol. If your supply gets easier, gun design usually gets harder, and visa versa 27-May-19 05:45 PM Application is also important too. How far the beam must travel, it's use, beam parameters, etc. Needing to transport the beam a few mm vs a meter makes a big difference. Thermionic emission guns also need at least reasonable vacuum to prevent the filament from dying too quickly. A 100mA beam is going to kill filaments fast, and you will need a beefier filament with decent vacuum, probably 10^-6 torr at least 28-May-19 12:37 AM what is a goink on a 28-May-19 03:39 AM Joined the server. 28-May-19 06:10 AM Good morning 28-May-19 06:10 AM 9:12am here in Chile 28-May-19 06:50 AM Anyone have experience making his own feedthroughs with alumina tube? 28-May-19 06:50 AM I was quoting a 3 poles HV feedthrough in China for 20kv at 450 USD aprox 28-May-19 06:50 AM I dont know if the price is fine 28-May-19 07:08 AM DIY feedthrough with alumina tube 28-May-19 07:08 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/2014-06-14_10-28-53_653_zps90e37c56-0E9A1.jpg 28-May-19 07:08 AM It worth a try? Will work for 30kv? 28-May-19 07:09 AM only one way to find out 28-May-19 07:09 AM insulation distance along the tube is enough for 50 I'd say 28-May-19 07:09 AM but I don't know if the tube itself can withstand that 28-May-19 07:13 AM I think i can buy alumina tubes with thicker walls 28-May-19 07:13 AM I dont know hoy to "glue" or seal the copper conductor inside the alumina tube 28-May-19 07:14 AM 2k epoxy works well in vacuum 28-May-19 07:37 AM Maybe Im wrong. I think in the picture they didnt used any glue 28-May-19 07:37 AM Maybe they used a Swagelok cap in the left for sealing the conductor 28-May-19 07:38 AM No need to glue it. I've sketched out similar designs that just use compression fittings for all of the transitions 28-May-19 07:38 AM Like vacuum compression fittings, not plumbing ones lol 28-May-19 07:41 AM Wow. Now it seems to be very easy 28-May-19 07:41 AM It is lol 28-May-19 07:41 AM Hold in I'll draw it out roughly 28-May-19 07:42 AM Thanks Michael 28-May-19 07:52 AM Ok so this is just an arbitrary design for reference 28-May-19 07:52 AM Alumina tubes from Mcmaster have thin walls 28-May-19 07:52 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/alumina-FB6E6.png 28-May-19 07:56 AM Mounts to a 2.75"CF chamber inlet. 1" OD ceramic tube. 1/4" copper conductor. Substitute the sizes and compression fittings as needed 28-May-19 07:56 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20190528_105151-21C1D.jpg 28-May-19 07:59 AM Looks fast to build 28-May-19 07:59 AM What do you think about replacing all CF parts by glue? 28-May-19 07:59 AM Like JB Weld 28-May-19 07:59 AM So, make a dirt cheap feed through 28-May-19 07:59 AM Lukas recommended 2 epoxy 28-May-19 07:59 AM 2k epoxy 28-May-19 08:04 AM I wouldnt. It costs more initially up front, but if you are investing time and money in a vacuum system I'd do it right lol. Also, with non glued compression fittings you can make it very modular and change stuff out pretty easy 28-May-19 08:04 AM Yes. You are right 28-May-19 08:04 AM Just my opinion, different for everyone lol 28-May-19 08:04 AM Really depends on your goals 28-May-19 08:10 AM https://www.aliexpress.com/store/group/Al2O3-single-bore-Alumina-insulators-tubes/2343249_509303715.html?spm=2114.12010608.0.0.4bf914348cE8OQ 28-May-19 08:10 AM Alumina tubes are very cheap in aliexpress 28-May-19 08:59 AM moin! 28-May-19 10:07 AM moin 28-May-19 10:47 AM what's a good beginner vacuum chamber (for high vacuum stuff). I want to try PVD initially and maybe sputtering later 28-May-19 10:47 AM I see a lot of silicone degassing chambers on ebay. are those too leaky / outgassy for high vacuum? 28-May-19 10:47 AM maybe I should just get a bell jar and a stainless steel plate I can drill holes into? 28-May-19 10:47 AM I think that's basically the approach Applied Science (Ben Krasnow) used 28-May-19 10:57 AM Silicone degassing chambers aren't what you really associate with high vacuum lol 28-May-19 10:57 AM You can do basic sputtering at those levels though 28-May-19 10:57 AM Depends on what you mean by high vacuum tgougg 28-May-19 10:58 AM my pump can go down to 4 millitorr 28-May-19 10:58 AM I figured it was a long shot but they are made of stainless so I thought maybe 28-May-19 10:59 AM Yeah that's very low vacuum, roughing levels 28-May-19 10:59 AM You can do sputtering at roughing levels 28-May-19 10:59 AM Just the results won't be semiconductor grade lol 28-May-19 10:59 AM yeah I'm not worried about that 28-May-19 11:00 AM What type of sputtering though? 28-May-19 11:00 AM Thermal evap, magnetron, etc? 28-May-19 11:00 AM Thermal evap needs higher vacuum than magnetron 28-May-19 11:01 AM whatever is most basic, probably. I'm just a hobbyist 28-May-19 11:01 AM All of them are do able at the hobbyist level lol 28-May-19 11:01 AM Tradeoffs for each 28-May-19 11:01 AM Thermal evap is easier, but requires better vacuum 28-May-19 11:03 AM better than what I can achieve? I think I'll probably get a turbo eventually but for now I don't want to dump that much money into this 28-May-19 11:03 AM Yeah 28-May-19 11:03 AM Thermal evap requires better mean free path 28-May-19 11:03 AM At least probably 10^-4 for reasonable results 28-May-19 11:04 AM Yea I mean you can get a good vacuum with a small turbo or diff for evap work. Which you can get fairly clean... 28-May-19 11:04 AM Most configs are just a bell jar with an oring seal to like an aluminum base plate 28-May-19 11:04 AM Some high current feed throughs, etc. 28-May-19 11:04 AM Yeah, bell jar is common for evap 28-May-19 11:04 AM But they use at least a diff pump 28-May-19 11:05 AM But you can also get some old cryo heads that are trash for evap 28-May-19 11:05 AM Since we'll they have a few 1.33" conflat holes which are what most high current feed throughs are. 28-May-19 11:05 AM Some cryos are iso on the top so just with a simple iso blanking plate and using the roughing opening to rough the system... 28-May-19 11:06 AM Plasma assisted sputtering doesn't need as high vacuum, but setup is more complicated 28-May-19 11:06 AM eating, will be reading but can't type for a few minutes 28-May-19 11:06 AM @Nixie has experience with this 28-May-19 11:07 AM Yea sputtering requires a HV supply were as resistive evap just needs an old MOT converted for like 1-3V at a billion amps 28-May-19 11:07 AM I think resistive evap is what I meant by PVD 28-May-19 11:07 AM Which is super easy and cheap. But you need the higher vacuum. So both have trade offs 28-May-19 11:07 AM Yeah then you will need a high vacuum 28-May-19 11:07 AM But I think getting a higher vacuum is easier, but that's because I'm ignorant when it comes to HV systems. 28-May-19 11:08 AM well I guess there are some pretty cheap diffusion pumps on ebay 28-May-19 11:08 AM It all depends on how well you plan in advance 28-May-19 11:08 AM idk how hard those are to get running 28-May-19 11:08 AM A lot of people struggle since they rush in without prior research 28-May-19 11:08 AM In my experience with my system, diff pumps are fantastic. If you have cooling and a baffle lol 28-May-19 11:09 AM Diffusion pumps generally need to be adapted but they are pretty bulletproof 28-May-19 11:09 AM Yeah they are pretty indestructible lol 28-May-19 11:09 AM But you will need a cold trap and chilled water for a clean eviroment 28-May-19 11:09 AM Can take huge contamination 28-May-19 11:09 AM Otherwise you'll have some oil backstreaming 28-May-19 11:09 AM Also I'd recommend 705 oil 28-May-19 11:09 AM At min for this 28-May-19 11:10 AM There are some edwards 306 evap systems going up for auction next week. 28-May-19 11:10 AM If they go cheap I'll likely end up with one or more of them... But it depends. 28-May-19 11:10 AM I'll have to rent a truck if I get anything more than just small stuff lol 28-May-19 11:10 AM They have a ton of great stuff there even with this last call auction. Like enough to get a silicon production line up and running basically which is terrifying haha 28-May-19 11:10 AM Mostly larger machines left though so unless someone wants to pay to freight stuff... 28-May-19 11:16 AM For basic evap sputtering you can make a setup reasonably easily without a massive cost if you are patient on ebay and have some planning ahead of time 28-May-19 11:16 AM They have a few RIE systems I really would love to get one of those since I can build an evap system no problem. That's easy. But RIE is fairly complex 28-May-19 11:16 AM Oh absolutely. 28-May-19 11:18 AM back 28-May-19 11:18 AM And if people here need roughing pumps I'll be getting a ton of them and most of them are smaller so good for simple smaller chambers. But I'm going to go through and test them. If they are working OK and clean Id be happy to part with them for a fair price to help people avoid getting into the situation I did when I got my first pump which was a discustingly broken pump... 28-May-19 11:18 AM Which wouldnt be a problem if you didn't just like spend 150 bucks on the pump which now needs a rebuild that costs like 200-300 dollars. 28-May-19 01:37 PM Too bad you are on the wrong side of the pond most likely 29-May-19 07:07 AM I have been wondering lately: How can I get a negative high voltage output from a flyback transformer? 29-May-19 07:07 AM It will work if I connect a flyback transformer in reverse Polarity? 29-May-19 07:07 AM (Reverse the secundary of course) 29-May-19 07:44 AM Joined the server. 29-May-19 08:35 AM Olivia is a bot 29-May-19 08:35 AM already took care of them 29-May-19 08:35 AM I know there are no real womeN in places like this 29-May-19 08:35 AM https://giphy.com/gifs/avengers-90ies-fwfTXz9n1IVr2 29-May-19 08:35 AM We are all virgin 29-May-19 08:35 AM I know there are no real womeN in places like this If only you knew 29-May-19 08:46 AM Female humans* 29-May-19 08:49 AM of course there are 29-May-19 08:49 AM we're not all grumpy old men, unlike the fusor forum 29-May-19 08:51 AM Yeah, not sure what you are getting at, but there are certainly women here doing high vacuum physics projects 29-May-19 12:11 PM sup 29-May-19 12:11 PM points in the general direction of rule #1 in #welcome ; sexism is not appreciated or welcome here 29-May-19 12:16 PM I'm going to go out on a limb and say "grumpy old men" is being used as a stereotypical behavior and not a literal statement, especially since I recall complaints about the forums being overrun with "kids" 29-May-19 12:19 PM perhaps, yeah, but i will remark that in my time browsing those forums, i saw exceptionally few instances of women in that environment, and in at least one of those instances they were made an awkward spectacle of 29-May-19 12:19 PM i know for a fact there are other women here besides myself 29-May-19 12:19 PM just, be respectful, is all 29-May-19 12:19 PM @chucrut re: your flyback question, you could try rectifying its high frequency AC output to get +/- HVDC, or you could feed it into a cockroft-walton multiplier (depending on your voltage/current needs) wired up for positive or negative-referenced output 29-May-19 12:19 PM this is assuming that your flyback doesn't already have a hardwired multiplier/cascade epoxied into it 29-May-19 12:19 PM (many "modern" CRT TV/monitor ones do) 29-May-19 02:48 PM Yea old TV/monitor flyback with new/external rectifier should work for + or - HV 29-May-19 04:59 PM @qualia @rfs I want to use a flyback with internal diodes. Without disconnecting the diodes. The flyback already have a DC output for 20kv. But I dont know if I can get negative high voltage from it 29-May-19 05:02 PM Flyback with internal diodes will probably be positive rectified. 29-May-19 05:34 PM yeah, unfortunately, you're gonna need to find an old fashioned flyback without the internal diodes, like one of these https://en.wikipedia.org/wiki/Flyback_transformer#/media/File:Flyback_transformer_arc.jpg 29-May-19 05:34 PM they do show up on ebay occasionally 29-May-19 05:35 PM Those put out more power anyway lol, and you can drive them harder 29-May-19 05:51 PM I have a pair of nos ones that look to be made post 2000 29-May-19 07:05 PM I cant understand why internal diodes are a problem for connecting the secondary in reverse polarity 29-May-19 07:42 PM Hey, I haven't posted here in a while, so sorry for just jumping back in 29-May-19 07:42 PM Been busy with non-science things unfortunately 29-May-19 07:42 PM But anyway 29-May-19 07:42 PM Is this a good vacuum pump 29-May-19 07:42 PM https://boston.craigslist.org/gbs/tls/d/norfolk-edwards-vacuum-pump/6897090459.html 29-May-19 07:42 PM And is it worth the price 29-May-19 07:42 PM Realized I don't actually know, haven't done enough vacuum stuff 29-May-19 08:10 PM @AdamMcCombs really quite likes the RV series of Edwards pumps 29-May-19 08:10 PM and that thing,'s OEM cost brand new, is .. squints.. $3341 29-May-19 08:10 PM so if it is actually brand new rv8, then, yeah, that does seem like quite the deal. rather more than i'd be able to spend at once on a pump, but, still 29-May-19 08:10 PM also hi @hedgeberg , been a while! 29-May-19 08:26 PM yea I would say thats a good deal for a new RV8, if thats within your budget @hedgeberg but you can also get roughing pumps for way cheaper if you want to save some cash 29-May-19 08:30 PM Hrrrrm I mean it's not within my budget rn but I might be able to call the seller and ask them to agree to payment in installments, or to wait a couple weeks until I could make it work 29-May-19 08:31 PM What do you need it for? 29-May-19 08:31 PM A few things, but first on the list is that I wanna try making a lyophilator for goofs 29-May-19 08:31 PM Also yeah heya @qualia good to see you, this is the problem with not using twitter anymore :/ 29-May-19 08:31 PM The upside is my mental health is way better without being constantly reminded how much I dislike people 29-May-19 08:31 PM (people in general, not anyone here to be clear) 29-May-19 08:31 PM (I really like everyone here, y'all are great) 29-May-19 08:31 PM But, yeah, I've got several projects down the line for which something like a vacuum pump would be good 29-May-19 08:31 PM The thing I'm wondering though is if it would be better to buy a damaged pump from eBay or something and repair it 29-May-19 08:31 PM And if so, how much would it save? 29-May-19 08:36 PM you could get very lucky and grab a grimy pump for $100-$150 off ebay or some other auction site that needs nothing other than an oil flush to get going back to spec 29-May-19 08:36 PM ooorrr you could buy that same pump and need a $200-$300 rebuild kit 29-May-19 08:37 PM I have a pile of roughing pumps and will be getting more... I am going to go through and test them all and I will be selling clean/working pumps with no guarantee if people need them, the biggest cost will likely be shipping 29-May-19 08:37 PM ^^ 29-May-19 08:38 PM Mostly some smaller pumps, think RV3-5 sized pumps for edwards fans but they are good for starting out and smaller projects 29-May-19 11:05 PM Dude seriously? I'm absolutely in if you decide to do that. If I don't say anything here between now and then or don't respond when you start, pls dm me 29-May-19 11:05 PM Side note, has anyone else gotten sick of all the discussion of the "5G war"? 29-May-19 11:05 PM Cuz maybe I'm misreading this since I'm just an EE person who's been out of the game, but it kinda feels like everyone is just constantly spreading telecom propaganda marketing matetials?? 30-May-19 01:05 AM -> #off-topic-thats-sometimes-on-topic 30-May-19 02:59 AM Valid 30-May-19 05:49 AM Joined the server. 30-May-19 07:30 AM For an alternative to a unrectified flyback coil try an old style automotive ignition coil. 30-May-19 09:42 AM Thanks @Charles for your suggestion 30-May-19 11:57 AM moin! 31-May-19 01:04 AM moin 31-May-19 01:11 AM Moin! 31-May-19 06:23 AM Good morning 31-May-19 08:42 AM moin! 31-May-19 12:43 PM Valid 01-Jun-19 05:17 AM I'm thinking using marble material for cnc machining high voltage insulator. Marble is relatively easy to machine and I think can handle high temperature for the electron gun. 01-Jun-19 05:17 AM But I dont know about marble outgassing 01-Jun-19 05:17 AM I was looking in NASA list for outgassing materials, but they haven't tested marble 01-Jun-19 09:09 AM Joined the server. 01-Jun-19 04:29 PM afternoon! 01-Jun-19 04:32 PM hi 01-Jun-19 07:18 PM Marble is a ban choice. It’s got a ton of contamination in it and it will break down to things that will work against you. You want what’s called wonderstone or grade A Lava stone. It’s pretty easy to shape with hand tools and you fire it when you are done and it works well in vacuum fires or unfired. 01-Jun-19 07:26 PM there's also macor machineable ceramic 02-Jun-19 04:21 AM Yes, but is more expensive. Marble is very cheap 02-Jun-19 04:24 AM Marble is just not going to handle vacuum very well and will get exponentially worse with tempurture, even after a long bake out. Depending on the kv and application you might be able to get away with it, but that seems unlikely. Vacuum arcing is going to be a non stop problem on something so porus 02-Jun-19 04:24 AM It's hard enough to get well engineered ceramics to work at high voltages, I can only imagine what a material as inconsistent as marble is going to do. The quarzt content is not going to help either. 02-Jun-19 04:53 AM http://www.technicalproductsinc.com/lava.html This is the material you want. It was used in millions of vacuum tubes and CRT’s for extra high voltage protection and arc reduction you can coat it with a suspension on very fine magnesium oxide. We used to use Phillips Milk Of Magnesia antacid without the mint flavoring and spray it with a paint gun and then lightly fire it in hydrogen. 02-Jun-19 07:19 AM @AdamMcCombs if it's hard enough to get well engineered ceramics to work at high voltages, maybe is easier not using any kind of insulator at all. Only vacuum as insulator. 02-Jun-19 07:19 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20190602_101838-E135F.jpg 02-Jun-19 07:19 AM Feedtroughs can be made strong enough to hold the tungsten filament 02-Jun-19 07:20 AM keep in mind that plastic softens way before its melting point 02-Jun-19 07:28 AM First off what kv are we talking? That's going the determine a lot. 02-Jun-19 07:29 AM The voltage is 20-30kv 02-Jun-19 08:29 AM I am using fused quartz for high voltage insulation in vacuum 02-Jun-19 08:29 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Fused_Quartz_Inuslator_Machined-8E0FD.jpg 02-Jun-19 08:29 AM It's not super easy to machine, grinding is the way to go if the geometry allows it. But there are specialized companies that supply tubes and rods for cheap 02-Jun-19 08:29 AM What is the required shape of the insulator? And what kind of machining capability do you have access to? 02-Jun-19 08:55 AM @Mason_Yu i have a metal lathe. I'm going to search quartz tubes. Maybe I can find quartz tubes with thicker walls than alumina tubes from mcmasters 02-Jun-19 08:56 AM https://technicalglass.com/product_pages/fused_quartz_tubing/fused_quartz_tubing.html 02-Jun-19 08:56 AM Will any of these sizes work? 02-Jun-19 08:56 AM Machining any ceramics on a manual lathe without a toolpost grinder will be a serious challenge 02-Jun-19 09:04 AM Many thanks @Mason_Yu Mason 02-Jun-19 09:04 AM Their prices are very accessible 02-Jun-19 09:04 AM I email them to quote some custom sizes tubes 02-Jun-19 09:05 AM I have access to ceramic machining capability at a very reasonable price as well 02-Jun-19 09:05 AM For example the tube I got costs $67, from a different company 02-Jun-19 09:06 AM Do you seal quartz tube with orings or using glue? 02-Jun-19 09:06 AM I use a viton o-ring seal, but not around the tube 02-Jun-19 09:07 AM You used oring for sealing the interior of the tube? 02-Jun-19 09:07 AM Between the conductor and the tube? 02-Jun-19 09:09 AM No, the seal is not made against the ceramic at all. There is an end plate that bolts onto the stainless steel flange and there is an o-ring groove machined on the face of the stainless flange 02-Jun-19 09:09 AM For illustration 02-Jun-19 09:09 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Cathode_Plate_Back_-B5094.jpg 02-Jun-19 09:09 AM To seal the gas leak through the ID of the tube, you will need another o-ring on the other side of that insulating end plate as well 02-Jun-19 09:09 AM I need to do this for a very high current feedthrough with very thick copper conductors 02-Jun-19 09:15 AM The proper way to do this is a porcelain insulator with a metalized band in the center for brazing the flange too and then another metalized band at the vacuum end to braze the conductor too. Companies make and sell them. Look up a book called vacuum sealing techniques. It’s available in the AVS technical reprint series and covers all of this stuff in depth. It’s available online I believe. 02-Jun-19 09:16 AM What kind of vacuum level are you going for? @chucrut 02-Jun-19 09:17 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20190528_105151-8764F.jpg 02-Jun-19 09:17 AM You are using this system? 02-Jun-19 09:17 AM I need 10^-4 pascal 02-Jun-19 09:18 AM No, I am not using compression fittings at all, my feedthrough is too large for that. 02-Jun-19 09:18 AM Okay, so o-rings are close to a no-go for that high of a vacuum requirement 02-Jun-19 09:18 AM I would recommend getting a proper commercial high voltage feedthrough with brazed ceramic then 02-Jun-19 09:21 AM Okay. Maybe the DIY approach is not easy in this case 02-Jun-19 01:01 PM O-rings will get you that far, though you are getting close to reasonable limits without some modification (chilling, concentric channel pumping, etc). However it will take a lot of pumping, baking would be advised, and everything else should be very well prepped. The turbo station we have at work has only ISO and KF, and it will get to 10^-8 torr eventually. KF will reach that low, though I don't know how far compression fittings are rated. 02-Jun-19 01:01 PM It's definitely tough though, you need to pretty much completely eliminate water vapor at those levels. 02-Jun-19 04:46 PM If you have time, look Chernobyl series 02-Jun-19 04:50 PM I've wanted to watch it, don't have HBO lol 02-Jun-19 05:36 PM Pirateproxy.cc 02-Jun-19 11:22 PM Quick note the McMaster Car ceramic is really bad at high vacuum and really bad at high voltage. 03-Jun-19 05:59 AM Good to know @AdamMcCombs 03-Jun-19 02:49 PM Joined the server. 05-Jun-19 10:11 AM moin! happy birthday to me! 05-Jun-19 10:20 AM Woohoo, congrats! 05-Jun-19 02:03 PM Happy birthday! 05-Jun-19 02:07 PM Happy birthday piGuy! 05-Jun-19 02:14 PM Thanks! 05-Jun-19 02:35 PM Happy birthday! 05-Jun-19 03:05 PM I hope you received a vacuum chamber for your birthday 05-Jun-19 07:02 PM All I want is a sputter coater for my birthday 05-Jun-19 07:54 PM So I got this diffusion pump for $180 05-Jun-19 07:54 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20190605_195416-7CA4A.jpg 05-Jun-19 07:54 PM It's a CVC model 1200 05-Jun-19 07:54 PM cool! 05-Jun-19 07:55 PM Unfortunately the heaters might be dead 05-Jun-19 07:55 PM Duniway is selling similar-looking heaters for $50 05-Jun-19 07:55 PM Is it worth it, or is this thing scrap? 05-Jun-19 07:55 PM The unit has 4 heaters 05-Jun-19 07:56 PM You would never need to scrap a diff pump if the heaters are dead, they are made to be replaceable 05-Jun-19 07:56 PM Really easy to remove and install 05-Jun-19 07:57 PM I get that, I'm just wondering if it's cheaper to get a working one 05-Jun-19 07:57 PM As long as the jet stack is good and the cooling lines are good, the diff pump is good 05-Jun-19 07:57 PM How does it look inside? 05-Jun-19 07:57 PM Haven't checked those yet 05-Jun-19 07:57 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20190605_195748-9DBC7.jpg 05-Jun-19 07:57 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20190605_195804-BD155.jpg 05-Jun-19 07:59 PM Seems like it looks fine and in good shape. 05-Jun-19 07:59 PM What are the specs of the pump? 05-Jun-19 08:00 PM Bolt circle is larger than my calipers (probably 160mm ID) 05-Jun-19 08:00 PM 135mm sorry 05-Jun-19 08:00 PM CVC stuff is hard to find info on 05-Jun-19 08:00 PM Lile cooling requirements, roughing, speed, power, etc 05-Jun-19 08:00 PM Info plate unreadable 05-Jun-19 08:01 PM Bigger pumps will cost more to run since you will need higher throughput roughing pump, more oil, more power, more cooling 05-Jun-19 08:02 PM Yeah I'm a bit concerned about power 05-Jun-19 08:02 PM Oil is expensive too 05-Jun-19 08:02 PM There were 5 diff pumps at the place I visited and I bought the smallest 05-Jun-19 08:03 PM It doesn't look too big, hard to tell though 05-Jun-19 08:03 PM Figured local pickup would save me money 05-Jun-19 08:03 PM You sure it uses 4 heaters on the pump? 05-Jun-19 08:03 PM Multi heaters are usually reserved for massive pumps 05-Jun-19 08:04 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20190605_200429-5A300.jpg 05-Jun-19 08:04 PM It's maybe 2 feet tall 05-Jun-19 08:04 PM I was thinking it was this heater https://www.duniway.com/part/cvc-120v 05-Jun-19 08:04 PM looks kind of similar to this unit https://www.ebay.com/itm/Bendix-High-Vacuum-Diffusion-Pump-CVC-Consolidated-5-5-Inch-ID-9-Inch-OD-Flange-/254164820166 05-Jun-19 08:10 PM bit of an odd style of heater lol. Its like a 5" inlet diameter? at 1200W, not too bad. The heaters though are for the smaller CVC PMC-2, you will want to make sure yours uses them as well 05-Jun-19 08:11 PM yeah 05-Jun-19 08:11 PM I'm pretty worried about even attaching stuff to the flange 05-Jun-19 08:13 PM so is yours a CVC PMC6? It looks close to it 05-Jun-19 08:13 PM that does look like it 05-Jun-19 08:13 PM there are so many ebay listings with the wrong product name for this thing lol 05-Jun-19 08:14 PM hold on, 4 heaters looks like a PMC-4 05-Jun-19 08:14 PM cross-reference chart: 05-Jun-19 08:14 PM http://daltonelectric.com/index.php/oem-cross-reference 05-Jun-19 08:15 PM ah thanks 05-Jun-19 08:15 PM I just found this https://www.myers-vacuum.com/update15/used-equipment/diffusion-pump-heater-replacment-guide/ 05-Jun-19 08:15 PM seems like the same 05-Jun-19 08:15 PM weird though, since nothing on the thing is 4 inches 05-Jun-19 08:16 PM yeah, I think its for the number of cartridges 05-Jun-19 08:16 PM damn the 48" diff pump on that chart 05-Jun-19 08:16 PM looks like its definitely a 120V PMC-4 05-Jun-19 08:16 PM can't even imagine that 05-Jun-19 08:17 PM found the pumping speed at least 05-Jun-19 08:17 PM looks like 720 L/s, but thats all Ive found so far 05-Jun-19 08:17 PM is that fast? 05-Jun-19 08:18 PM for reference, my Edwards EO4 diff pump is 850 watts, 600 L/s. 05-Jun-19 08:18 PM for amateur chambers, yeah, thats fast if you get it right to the chamber 05-Jun-19 08:18 PM with an ideal baffle however, straight to the chamber max efficiency is about 66% 05-Jun-19 08:18 PM I was originally hoping to get a edwards diffstak 100m but the guy had already sold it 05-Jun-19 08:18 PM so for my setup, I am realistically getting about 400 L/s 05-Jun-19 08:18 PM generally, diff pumps have pretty similar characteristics, so if you find a similar pump from a different manufacturer, specs will be comparable 05-Jun-19 08:18 PM the agilent VHS-4 is slightly bigger, at 1450W, 750 L/s. Backing requirements are 10 CFM, cooling at 0.15 g/m (15-26C), fluid charge of 300 cc 05-Jun-19 08:18 PM cooling requirements for water cooled diff pumps in the same class are all pretty much the same at least 05-Jun-19 08:37 PM Varian VHS-4 is the same specs, though the pumping speed shows up as either 750 L/s on the Ideal Vacuum website, though 1200 L/s in the actual original datasheet 05-Jun-19 08:37 PM it has a bulge as opposed to straight chamber though which improves pumping speed by increasing gas capture 05-Jun-19 08:37 PM I actually have the varian VHS-4, but haven't used it due to the much higher power needs and backing pump throughput of 10 CFM - that would be a very expensive roughing pump 05-Jun-19 08:44 PM my backing pump does 8.2 CFM 05-Jun-19 08:44 PM EO4 is slightly below yours, at 850W, 600 L/s, with 175 cc fluid fill, .26gpm cooling flow at 15-25C, 4cfm backing requirement 05-Jun-19 08:44 PM I think you could get away with that for your pump 05-Jun-19 08:44 PM tough to say for sure though without exact specs 05-Jun-19 08:44 PM but its probably fine as long as you are not maxing out gas loads in your chamber and pushing the diff pump to its limits, which would require some decent process gas loads anyway lol 05-Jun-19 08:46 PM oooh found something that looks like a manual maybe 05-Jun-19 08:46 PM http://www.fusor.net/board/viewtopic.php?t=9187 05-Jun-19 08:47 PM yeah thats it, lucky someone scanned it in 05-Jun-19 08:47 PM yours is the 4" (even though the flange is larger) 05-Jun-19 08:47 PM yeah looks like a PMC-4 05-Jun-19 08:47 PM yeah 05-Jun-19 08:47 PM 400 cc of pump fluid (oil?) 05-Jun-19 08:48 PM looks like 5cfm backing, so you are good lol 05-Jun-19 08:48 PM great 05-Jun-19 08:48 PM damn, seems like some weird proprietary flange 05-Jun-19 08:49 PM damn, 400cc is a lot of oil for that size. the larger VHS-4 only requires 300cc 05-Jun-19 08:50 PM that's $82 (for duniway DC-704) 05-Jun-19 08:51 PM .16 gpm flow rate, pretty standard for diff pumps 05-Jun-19 08:51 PM still a lot of fluid 05-Jun-19 08:51 PM for oil, not water lol 05-Jun-19 08:51 PM cvc seems like a pretty old one, doesn't seem like it lasted as long as the other major companies 05-Jun-19 08:52 PM yeah 05-Jun-19 08:52 PM the weirdness of this thing is definitely part of why it was cheap 05-Jun-19 08:52 PM 400cc for that size makes me think its a less efficient pump 05-Jun-19 08:52 PM yeah, you will need a custom adapter 05-Jun-19 08:52 PM i got custom adapters machined for mine, even though it was a standard flange anyway, to adapt to baffle, then 6" conflat chamber 05-Jun-19 08:54 PM so I understand that aluminum isn't great for high vacuum stuff but I don't exactly have a machine shop, do you think I could get away with drilling some holes in 1/4" thick aluminum plate and JB welding on a KF adapter 05-Jun-19 08:54 PM or brazing maybe 05-Jun-19 08:55 PM aluminum is perfectly fine for high vacuum 05-Jun-19 08:55 PM nothing wrong with aluminum, it is UHV compatible 05-Jun-19 08:55 PM gotcha 05-Jun-19 08:55 PM maybe this is incorrect folklore I saw somewhere 05-Jun-19 08:56 PM my adapter plates are aluminum lol 05-Jun-19 08:57 PM oh yeah does it matter which kind of diffusion pump oil I get? like DC-704 versus 705 versus Santovac 05-Jun-19 08:58 PM it depends 05-Jun-19 08:58 PM I guess it just depends what kind of pressure I'm aiming for? 05-Jun-19 08:58 PM the lower the grade, the less clean it is due to worse backstreaming and vapor pressure, but can handle higher contamination loads 05-Jun-19 08:58 PM like 702 is lowest grade, but you use that for large bulk chemical vapor degassing 05-Jun-19 08:58 PM 704 average general purpose, not semiconductors or clean processes 05-Jun-19 08:58 PM 705 can be used with clean processes 05-Jun-19 08:58 PM santovac is crazy expensive, but semiconductor grade 05-Jun-19 08:59 PM so 704 is probably best for me 05-Jun-19 09:01 PM yeah, depends on what you want to do. Like for me, I'm doing space stuff, so 705 is much better than 704. I don't need santovac however 05-Jun-19 09:02 PM I mean it's $80 versus $150 05-Jun-19 09:02 PM yeah, though backstreaming and ultimate pressure is improved 05-Jun-19 09:02 PM yeah 05-Jun-19 09:02 PM no I was saying not much of a diff 05-Jun-19 09:03 PM for me, its worth the cost. depends on what you are trying to accomplish 05-Jun-19 09:03 PM oh lol 05-Jun-19 09:03 PM in either case though, you will want a baffle 05-Jun-19 09:03 PM you mean like a cold trap? 05-Jun-19 09:04 PM cold trap isn't necessary, water cooled baffle is perfectly fine unless you trying to push past like 10^-7 torr 05-Jun-19 09:04 PM okay cool 05-Jun-19 09:04 PM idk how to google for this 05-Jun-19 09:07 PM I use water cooled. You can get away with a passive baffle to impede some of the backstreaming, though there will still be some backstreaming. Cooling helps condesne the vapors back. Also could do something like an externally cooled 90 degree bend if you get desperate and can't find a baffle. Some older systems I have seen actually does this 05-Jun-19 09:08 PM ah okay so this is something I should build/cobble, rather than buy? 05-Jun-19 09:09 PM I would still try to see if you can find one on ebay or surplus, but they aren't as common 05-Jun-19 09:09 PM so it's basically a water cooled heatsink that obstructs the flow? 05-Jun-19 09:09 PM judging from the pics on http://www.vacuumbaffles.com/products.html 05-Jun-19 09:10 PM like I said though, you could get away with some other options worst case scenario, like build your own passive baffle to act like a cold-cap by having it touch the water-cooled walls, or a cooled bend 05-Jun-19 09:10 PM pretty much lol 05-Jun-19 09:10 PM an ideal baffle will have an optically opaque line of sight, but still allow about 60% of the pumping speed 05-Jun-19 09:14 PM stuff like this seems like it would work decently https://www.ebay.com/i/253029856452?chn=ps ? 05-Jun-19 09:14 PM maybe with a bucket of ice or something 05-Jun-19 09:18 PM You would want the baffle to sit over the diff pump. Like mate to the surface of the oring, then the chamber connection above. 05-Jun-19 09:18 PM I was thinking that it would go above the adapter plate 05-Jun-19 09:18 PM and have a square hole 05-Jun-19 09:18 PM so I'd lose some flow, but I'm planning for that anyway 05-Jun-19 09:19 PM Yeah that could work, though you need to feed water into high vacuum 05-Jun-19 09:19 PM And a system like that would scare me right over the diff pump lol. Those connections are not high vacuum rated, and if it sprung a leak inside it would be a bad day 05-Jun-19 09:22 PM lol good point 05-Jun-19 09:22 PM 1200 W of electricity + HOT OIL + water 05-Jun-19 09:39 PM what about activated charcoal 05-Jun-19 09:40 PM Unless you have the square hole with an o ring groove and have that mate to the radiator edge so the watee feeds are at atmosphere, but I doubt the surfaces are flat enough for thst 05-Jun-19 09:40 PM I'm reading https://doi.org/10.1063/1.1751709 05-Jun-19 09:40 PM Activated charcoal in the high vacuum area would probably be a bad idea 05-Jun-19 09:40 PM I haven't seen charcoal traps used on the high vacuum side for diff pumps 05-Jun-19 09:41 PM "The use of activated charcoal or other materials having similar properties such as silica gel, P2O5 , etc., is well known and the ability of such traps to absorb gases has been investigated by many workers. It is probable that the lowest pressures ever attained have been reached in this manner." 05-Jun-19 09:41 PM the main problem seems to be admittance? 05-Jun-19 09:42 PM For sorbtion based trapping, they work best cooled 05-Jun-19 09:42 PM Also they will saturate eventually and have to be baked to release water vapor 05-Jun-19 09:43 PM seems like a pain 05-Jun-19 09:44 PM Yeah lol, you can do externally cooled fins. If you have the fins with good thermal contact to the wall surfaces which are cooled from the outside, that can work too, and can be easier to build 05-Jun-19 09:44 PM That's how passive cold caps in diffusion pumps work 05-Jun-19 09:44 PM At the top of the stack, there is a cap that can be placed that has a clamp that makes solid contact with the walls. Since the inlet cooling flow is at the top, it is coolest at the top of the pump, and can cool the cap to help with some backstreaming 05-Jun-19 09:44 PM My EO4 has one 05-Jun-19 09:44 PM You can do the same with an adapter plate 05-Jun-19 09:46 PM lol this paper is hilarious 05-Jun-19 09:46 PM Maybe 1" thick aluminum, and make baffle plates that touch the sides. Then run some cooling lines on the outside and cool the plate 05-Jun-19 09:47 PM it suggests using refrigerator cooling coils 05-Jun-19 09:47 PM it's from 1940 05-Jun-19 09:47 PM Actually that is one way. Meissner traps are just cooling coils inserted into the system 05-Jun-19 09:47 PM Or, like I mentioned, you can get a large 90 degree elbow piece and cool that, and add some simple baffle sheets inside as well 05-Jun-19 09:49 PM could I cut a tube at 45 degrees and glue or braze it together? 05-Jun-19 09:49 PM I don't really have a good sense for how much pressure 1 atm actually is 05-Jun-19 09:49 PM a 90 degree elbow at that size just seems like it would be pricey 05-Jun-19 09:50 PM I would go with standard vacuum bends for that 05-Jun-19 09:51 PM oh you mean after the adapter 05-Jun-19 09:51 PM like a KF-40 elbow or something 05-Jun-19 09:51 PM I think cheapest option is externally cooled adapter plate with passive fins touching the walls inside 05-Jun-19 09:51 PM yeah with maybe phase change chiller 05-Jun-19 09:51 PM or peltier 05-Jun-19 09:51 PM or ice bath 05-Jun-19 09:52 PM Since you need to most likely make an adapter, might as well make it multi purpose lol 05-Jun-19 09:52 PM idk how much heat this thing actually has to sink now that I think about it 05-Jun-19 09:52 PM like obviously it's somewhere between 0 and 1200W 05-Jun-19 09:52 PM The baffle shouldn't see that much heat load 05-Jun-19 09:52 PM I built a closed loop peltier chilled system for mine 05-Jun-19 09:53 PM okay so peltier is feasible 05-Jun-19 09:53 PM For the diff pump and baffle 05-Jun-19 09:53 PM It is feasible, but you have to really design it right 05-Jun-19 09:53 PM I'm not using the peltier to handle the full diff pump load 05-Jun-19 09:53 PM It runs in parallel with a main air cooled heat exchanger 05-Jun-19 09:53 PM It's a triple loop system 05-Jun-19 09:54 PM I see 05-Jun-19 09:54 PM Mine operates around 22-23C steady state full load 05-Jun-19 09:54 PM http://appliedionsystems.com/portfolio/closed-loop-peltier-water-chiller-for-diffusion-pump-cooling/ 05-Jun-19 09:54 PM And the chiller block: 05-Jun-19 09:54 PM http://appliedionsystems.com/portfolio/peltier-chiller-module/ 05-Jun-19 09:56 PM btw is brazing good for vacuum? I can't weld (yet) 05-Jun-19 09:57 PM Depends on your vacuum and how good you are lol 05-Jun-19 09:57 PM this question is ungoogleable because there's a technique called vacuum brazing 05-Jun-19 09:57 PM I've never brazed 05-Jun-19 09:57 PM Yeah vacuum brazing or hydrogen furnace brazing is used for complex UHV assemblies like particle accelerator sections 05-Jun-19 09:57 PM Or ceramic component to metal brazing 05-Jun-19 09:57 PM But that's like top of the line brazing, really advanced stuff 05-Jun-19 09:58 PM no I know, I was just saying that vacuum brazing is what pops up when you google "brazing high vacuum" 05-Jun-19 09:58 PM so you can't find e.g. forum posts on whether brazing is okay for high vacuum 05-Jun-19 09:59 PM It is, but it depends on how you do it 05-Jun-19 09:59 PM Most amateurs don't have the skillset for UHV level stuff. High vacuum can be done. But you need to select the right braze material and really do it well 05-Jun-19 10:02 PM is there a better bonding technique (other than welding, which I can't really feasibly do in my current apartment)? 05-Jun-19 10:02 PM I know there's epoxy (/ JB weld) but I assume that's just for feedthroughs and stuff? 06-Jun-19 05:29 AM is SEM talk OT or not? ^^ 06-Jun-19 09:52 AM Sem talk is always ot 06-Jun-19 10:51 AM ... Uh... Does OT mean On Topic or Off Topic...??? You all are going to get yourselves in trouble using these abbreviations lol. Because that could have been Noon asking if its off topic, then Adam saying its always on topic. Which of-course noon would read as always being off topic... 06-Jun-19 01:25 PM But of-course, Adam being Adam, he 100% meant that SEM talk is ALWAYS on topic :P 06-Jun-19 10:58 PM ah ok 06-Jun-19 10:58 PM sooo if in remove then end aperture or even more apertures up the liner, i'll get pretty "higher" currents, right? 06-Jun-19 10:58 PM @AdamMcCombs mentioned something like that iirc months ago 06-Jun-19 11:01 PM Possibly. Final/objective app will make biggest difference 06-Jun-19 11:02 PM okay 06-Jun-19 11:02 PM humm 06-Jun-19 11:02 PM What are you going for? If you really want a lot if current change the filament bias/spacing to the whenalt 06-Jun-19 11:02 PM Bit see if you can open up the final ap first 06-Jun-19 11:02 PM If you are using a ds130 throw all this out the window 06-Jun-19 11:04 PM i read about micro- and nano joining 06-Jun-19 11:04 PM Oh lol 06-Jun-19 11:04 PM Sem gun design is just not made for it 06-Jun-19 11:04 PM out of the window as in "forget it"? 06-Jun-19 11:05 PM No it's just different 06-Jun-19 11:05 PM wait the book said for powers <= 10W use a SEM 06-Jun-19 11:05 PM I think the most you can get from a sem is in the -6 or -7 range 06-Jun-19 11:05 PM That's lower than I was expecting 06-Jun-19 11:06 PM what is okay if you only want to weld some micrometer thick things (according to the book) 06-Jun-19 11:06 PM ah ok 06-Jun-19 11:06 PM Micrometer makes sense though 06-Jun-19 11:06 PM Are you using a DS 130? 06-Jun-19 11:07 PM yeah i would 06-Jun-19 11:07 PM or another like SS 60 06-Jun-19 11:07 PM Put the condensor in to manual and try to eliminate crossovers running with the final app out and the condenser app fully retracted 06-Jun-19 11:07 PM It's going to burn through your scintillators like crazy but shouldn't be too bad otherwise 06-Jun-19 11:08 PM yeah thats also mentioned in the book 06-Jun-19 11:08 PM with the condensor 06-Jun-19 11:09 PM Will also cause more contamination but that's just kinda to be expected with that much current 06-Jun-19 11:09 PM Adam your going to have to come over to help me lift the DS130 out the window if you think thats a good idea :P 06-Jun-19 11:10 PM ? 06-Jun-19 11:10 PM You mentioned throwing it out the window 06-Jun-19 11:10 PM its kinda heavy to throw :P 06-Jun-19 11:10 PM Oh 06-Jun-19 11:10 PM Yeah you need pnumatics 06-Jun-19 11:10 PM Like really big pnumatics 06-Jun-19 11:16 PM Think you meant hydraulics :P 06-Jun-19 11:48 PM the hydraulic sem channel 06-Jun-19 11:48 PM btw do you guys have ever seen an "atmospheric" particle beam with your own eyes? i only know such photographs 06-Jun-19 11:48 PM https://upload.wikimedia.org/wikipedia/commons/b/ba/Cyclotron_with_glowing_beam.jpg 07-Jun-19 05:04 AM Generally beams need to be high enough energy to pass through a foil of a certain thickness to atmosphere. If you are at that level, radiation would make it dangerous to be around. You can pass low energy ebeam through foil, like less than 100kev, but the foil has to be incredibly thin and travel will be like a cm in air. Most ebeam particle accelerators for research will extract the beam to air to run experiments for irradiation, neutron production, etc. The linac I work at does that. At 60 mev, the beam will travel many feet in the air. For such machines, it would be lethal to be around to witness it. Proton accelerators will also do the same, but energy has to be higher for an equivalent foil window thickness due to larger size of the particles. Xrays are not as much of a hazard with proton machines vs ebeam machines, but you still have radiation from proton interactions and activation if the energy is high enough. For the one in the picture, it most certainly would be. The glow at atmosphere is the ionization of air from the beam. 07-Jun-19 05:04 AM Colliders will stay in vacuum. Also the intensity of the glow will be a function of beam current as well. Higher beam current, the more dangerous the beam is 07-Jun-19 05:43 AM ok but u could use a thick enough window? 07-Jun-19 05:43 AM or mirrors? 07-Jun-19 05:43 AM to make it visible behind the shield 07-Jun-19 05:43 AM i guess i would go for mirrors :3 07-Jun-19 05:46 AM Window won't really protect you against xrays unless it's leaded glass 07-Jun-19 05:47 AM yep 07-Jun-19 05:47 AM i mean leaded glass 07-Jun-19 05:47 AM Wy, you thinking about atmospheric extraction? 07-Jun-19 05:47 AM but mirrors are more elegant 07-Jun-19 05:47 AM just for curiosity 07-Jun-19 05:47 AM i mean, it's like amateur astronomy 07-Jun-19 05:47 AM capturing the photons with your own retina 07-Jun-19 05:48 AM If I ever get EXEDA running I could have pictures of a pretty intense beam in air lol 07-Jun-19 05:48 AM yeah, that would be awesome 07-Jun-19 05:49 AM I'd have to figure out safety, still don't have the space to run something like that in air 07-Jun-19 05:49 AM i mean, storage rings like LHC et al have "beam dumps" right? 07-Jun-19 05:49 AM mostly concrete (?) blocks in a atmospheric chamber, right? 07-Jun-19 05:50 AM Yeah lol, they are huge at that energy 07-Jun-19 05:50 AM but no "optical" sensors 07-Jun-19 05:50 AM "only" IR stuff afaik 07-Jun-19 05:50 AM y they don't have "normal" cameras in there 07-Jun-19 05:50 AM or have they? if, where is the footage? ^^ 07-Jun-19 05:51 AM Our beam dump is literally a giant soup pot from mcmaster-carr filled with water and lead bricks 07-Jun-19 05:51 AM I doubt they take pictures, the bean dumps would only have current monitoring really 07-Jun-19 05:51 AM ok, mount a gopro? 07-Jun-19 05:51 AM i mean, the whole things costs 10^10 euro or something 07-Jun-19 05:51 AM y no gopro? 07-Jun-19 05:51 AM with mirrors or fiber optics, i dunno 07-Jun-19 05:52 AM No need really, they just need to make sure the beam gets dumped, you can measure that with current, since the beam dump can double as a Faraday cup 07-Jun-19 05:52 AM to prevent it getting fried 07-Jun-19 05:52 AM but it should look cool? 07-Jun-19 05:52 AM even this old image from a small cyclotron looks cool 07-Jun-19 05:54 AM You don't want a high energy beam traveling far in air since it activates the air. Generally want to minimize air exposure, though air has a very short half life anyway 07-Jun-19 05:54 AM a LHC beam in atmosphere must be optical badass 07-Jun-19 05:54 AM It depends, it may be too low current, or too high energy to see anything lol 07-Jun-19 05:54 AM you mean there is no air in the beam dump chambers? 07-Jun-19 05:54 AM Also if it's a single pulse vs continuous vs rep rate 07-Jun-19 05:54 AM aka vacuum? 07-Jun-19 05:55 AM You can have air fine, just generally you want to minimize total travel in air 07-Jun-19 05:55 AM but i guess it's hard to make a large concrete block vacuum compatible? 07-Jun-19 05:55 AM ok, the free way is short, you mean that? 07-Jun-19 05:55 AM ok, would be interesting to know the free air traveling distance 07-Jun-19 05:55 AM i don't find the documentation about that detail 07-Jun-19 05:56 AM Chances are the beam gets extracted through a window and goes right into the dump with minimal air gap 07-Jun-19 05:56 AM I think I have papers on high energy beam dump design lol 07-Jun-19 05:56 AM ah, it's graphite 07-Jun-19 05:56 AM Yeah, graphite, copper, and aluminum are the most common 07-Jun-19 05:56 AM Graphite has the lowest activation energy 07-Jun-19 05:56 AM Copper usually used with higher power beams 07-Jun-19 05:57 AM http://www.lhc-facts.ch/index.php?page=strahlenergie 07-Jun-19 05:57 AM fun 07-Jun-19 05:57 AM Usually there can be multiple layers of different materials to slow beam and dissipate energy across a spectrum 07-Jun-19 06:10 AM yeah first they spread it with a magnet etc 08-Jun-19 05:10 AM Anyone going to Sunnyvale Electronics Flea Market today? @qualia 08-Jun-19 09:19 AM I'm headed there now! 08-Jun-19 03:11 PM Joined the server. 09-Jun-19 04:40 AM Joined the server. 09-Jun-19 03:09 PM Joined the server. 09-Jun-19 03:37 PM Hi 09-Jun-19 03:37 PM Any advice for cleaning the vacuum chamber? 09-Jun-19 03:37 PM Acetone is okay? 09-Jun-19 03:38 PM I think some solvents can be contaminated with impurities that offgas later 09-Jun-19 03:38 PM so the purity of the acetone matters 09-Jun-19 03:39 PM Or is better with acid? 09-Jun-19 04:11 PM Acetone, till its clean, then ethonal or alcohol, not IPA, but like pure grain alcohol. 09-Jun-19 04:11 PM Acetone does leave stuff behind, thus you go back with some high purity alcohol, high proof grain alcohol works to give everything a final wipedown. 09-Jun-19 04:20 PM Isopropyl alcohol is not recommended? 09-Jun-19 04:24 PM IPA also leaves residue behind 09-Jun-19 04:24 PM This is what I've been told anyway, so yea for HV parts your best off going to a liquor store and getting the highest grain proof alcohol you can. Or going to a chemical store and buying high grade ethanol, but thats quite a bit more expensive and more of a pain to do. 09-Jun-19 07:50 PM It depends on what vacuum you are getting to and what your process is 09-Jun-19 07:50 PM Also depends on what grade of IPA you can get 09-Jun-19 11:36 PM I know when cleaning wafers (even with VLSI grade acetone and IPA) you don’t just use acetone, you use acetone then rinse with IPA before it dries, because acetone leaves a scum 09-Jun-19 11:36 PM Yeah you pretty much never leave acetone 09-Jun-19 11:36 PM Hardware store stuff is bad, lab grade stuff is only kinda bad 09-Jun-19 11:56 PM Hi everyone 10-Jun-19 04:57 AM Hi @a_quiet_scientist 10-Jun-19 04:57 AM We need to apply a turing test to @a_quiet_scientist to check if is human 10-Jun-19 07:16 AM Human somewhat, like those memes mocking Zuckerberg 10-Jun-19 07:59 AM moin! 11-Jun-19 05:49 PM Any advices on neodymium magnet outgassing in vacuum? 11-Jun-19 05:52 PM Keep pulling a vacuum until it stops? :P 11-Jun-19 06:44 PM i've used Nd magnets in vacuum before, they shouldn't pose a problem -- assuming they're clean 11-Jun-19 06:44 PM mine were nickel plated (pretty typical), no issues 11-Jun-19 07:16 PM yea if they are nickel plated I'd assume they shouldn't have much issue if you clean them down first. 12-Jun-19 10:12 AM moin! 12-Jun-19 10:42 AM Moin! 12-Jun-19 10:42 AM o/ 12-Jun-19 10:44 AM I got a new chamber today \o/ 12-Jun-19 10:44 AM well "chamber" 12-Jun-19 10:44 AM it's an ISO-100 cross 12-Jun-19 10:44 AM Anything's a chamber if you're brave enough? 12-Jun-19 10:45 AM but it's the first chamber I have that has an opening bigger than KF40 12-Jun-19 10:45 AM but not everything goes down to e-8, even if you're brave enough 12-Jun-19 10:46 AM not with that attitude 12-Jun-19 10:47 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190612_181529-8CFE5.jpg 12-Jun-19 10:47 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190612_181518-4279E.jpg 12-Jun-19 10:47 AM fun 12-Jun-19 10:47 AM fun sized 12-Jun-19 10:47 AM not I need two more flanges 12-Jun-19 10:47 AM and I hope I can make them on the lathe 12-Jun-19 10:47 AM the issue is workholding, since 130mm is the absolute maximum I an turn 12-Jun-19 10:47 AM it's not the maximum my chuck takes but 6.5 cm is the distance from the spindle centre to the bed 12-Jun-19 10:47 AM so workholding is going to be an adventure 12-Jun-19 10:47 AM I can't really use an superglue arbor, since the surface of my Al stock isn't flat 12-Jun-19 10:47 AM and I can't make it flat without turning it 12-Jun-19 10:51 AM time to buy a granite surface plate 12-Jun-19 10:51 AM I'm sure HGR will freight you one :D 12-Jun-19 10:52 AM I don't need a surface plate to know the face isn't flat 12-Jun-19 10:52 AM you put sandpaper on the surface plate :P 12-Jun-19 10:52 AM alternatively make your own from 3 faces of stock 12-Jun-19 10:52 AM making a flat face is easy 12-Jun-19 10:52 AM just time consuming 12-Jun-19 10:52 AM sanding a 130mm blank down by ~2mm is going to be fun 12-Jun-19 10:53 AM making a true flat face requires more work 12-Jun-19 10:53 AM just use the proper grit 12-Jun-19 10:53 AM it's Al, not hardened steel 12-Jun-19 10:53 AM only has to be flat enough to stick to superglue 12-Jun-19 10:53 AM A non smooth surface from a lower grit would likely make it stick even better 12-Jun-19 10:53 AM maybe I'll find someone with a lathe big enough 12-Jun-19 10:54 AM attach it to your car tire 12-Jun-19 10:54 AM get a jack stand 12-Jun-19 10:54 AM ???? 12-Jun-19 10:54 AM Profit 12-Jun-19 10:54 AM I din't have a car 12-Jun-19 10:54 AM bike tire? 12-Jun-19 10:54 AM microwave turntable? 12-Jun-19 10:54 AM ceiling fan? 12-Jun-19 10:55 AM xD 12-Jun-19 03:09 PM Looking good @GigaSquirrel :) 12-Jun-19 03:10 PM Thanks! 12-Jun-19 04:11 PM Nice! You can directly mount an ISO100 turbo without necking down the turbo at all 12-Jun-19 07:16 PM Joined the server. 12-Jun-19 08:59 PM @Andero#7456 >_> 12-Jun-19 08:59 PM Wait did Andero join and leave already? 12-Jun-19 11:17 PM they joined and left one minute later 12-Jun-19 11:17 PM @a_quiet_scientist I know, right? 12-Jun-19 11:17 PM I'll measure its actual pumping speed, will be interesting 13-Jun-19 10:14 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/voltmultip22-67A9B.jpg 13-Jun-19 10:14 AM Look what i found 13-Jun-19 10:14 AM Maybe is easier to make a voltage multiplier for generating Negative HV 13-Jun-19 10:14 AM I cannot find negative output flybacks 14-Jun-19 09:54 AM older flybacks without a built in rectifier are just transformers, so you can get whatever polarity output you want, depending on how you rectify it. 14-Jun-19 12:14 PM Any tips for someone trying to get a hose adapter into a rubber hose with the metal slinky embedded in it? 14-Jun-19 12:14 PM Should I be greasing the adapter up? 14-Jun-19 12:14 PM Adapter is for 1/2" ID hose and I've measured hose to be 1/2" ID 14-Jun-19 12:14 PM I can get this thing like a third inch on, but not the full inch of barb 14-Jun-19 01:54 PM Yeah use grease and a liberal application of force 14-Jun-19 01:54 PM maybe a heat gun 14-Jun-19 02:38 PM Hey @AdamMcCombs in the server's avatar, is the vacuum pump on that thing directly mounted to that chamber, or did y'all couple it through a hose to keep it away from sputtering/stray e-fields/Deadly Radiations 14-Jun-19 03:09 PM Oh, the avatar is a vacuum chamber 14-Jun-19 03:09 PM I thought it was some vaporwave picture of something in a parka with a dark face and glowing purple eyes 14-Jun-19 03:09 PM like some kind of cyberpunk ice climber 14-Jun-19 03:41 PM the avatar is the northwest nuclear consortium's beam-on-target research fusor, iirc 14-Jun-19 09:14 PM @rfs o think I mentioned before somewhere. You can possibly use an automotive ignition coil or if that’s to high in voltage use a fly back transformer from a tube television. They have no rectifier. Additionally one from a tube type CRO can possibly work. Or possibly even a microwave oven transformer. 14-Jun-19 09:14 PM Just some thoughts of what you might find in a junk pile somewhere 14-Jun-19 09:14 PM Oh and also possibly an old neon sign transformer 15-Jun-19 05:06 AM Yep 15-Jun-19 06:41 AM @AdamMcCombs we have grease and a heat gun. Will use both sparingly. Thanks 15-Jun-19 12:03 PM :3 16-Jun-19 10:32 PM <__ice9#6039> Joined the server. 16-Jun-19 11:58 PM So, figure if anyone would appreciate this it's you guys 16-Jun-19 11:58 PM https://twitter.com/hedgeberg/status/1140513697846255616?s=19 17-Jun-19 03:34 PM @__ice9 o hai 17-Jun-19 06:44 PM O/ @qualia 17-Jun-19 06:44 PM Btw saw your hair pics during my short log on time, the color is really cool :O 17-Jun-19 06:53 PM ty :3 18-Jun-19 01:23 PM I concur, beautiful blue color <3 18-Jun-19 10:47 PM moin 19-Jun-19 07:23 AM <__ice9#6039> HAI 19-Jun-19 07:23 AM <__ice9#6039> I was hoping I might find you here as well 19-Jun-19 07:23 AM <__ice9#6039> Ah yeah that turned out well color gradient wise 19-Jun-19 07:23 AM <__ice9#6039> NICE LATHE! 19-Jun-19 07:23 AM <__ice9#6039> @hedgeberg following ^^ also I like your handle, very humorous to me having done some work in the fund management space 19-Jun-19 07:23 AM <__ice9#6039> But yeah that's a very impressive restoration and looks super useful 19-Jun-19 07:23 AM <__ice9#6039> It is indeed appreciated 19-Jun-19 11:05 PM moin 19-Jun-19 11:05 PM where do you guys buy isotopically pure elements? 19-Jun-19 11:05 PM "pure" like highly enriched 19-Jun-19 11:16 PM i know about americanelements.com but it would be nice to have (cheap :3) alternatives 20-Jun-19 04:17 AM <__ice9#6039> eBay 20-Jun-19 04:17 AM <__ice9#6039> It's very hit-or-miss, but it's often worth doing a very quick search first 20-Jun-19 04:17 AM <__ice9#6039> United Nuclear sometimes has things as well, but usually pretty basic 20-Jun-19 04:17 AM <__ice9#6039> American Elements I have found tends not to have very good pricing, though selection is excellent. They are sort of like the McMaster-Carr of materials science. 20-Jun-19 08:18 AM ah ok thanks for the hint 20-Jun-19 02:01 PM also depends on what sort of enriched thing you're looking for 20-Jun-19 02:01 PM apparently at one point you could buy 6LiF powder on amazon. coulda sworn i saw it in a 'Currently unavailable' listing once 20-Jun-19 02:09 PM just buying Li6 would be awesome... 20-Jun-19 02:23 PM i know the NRC regulates lithium isotope separation equipment in the same way they would other enrichment hardware, so it's probably slightly harder to get ahold of due to that 20-Jun-19 02:23 PM i know one weird isotope i was briefly curious about was calcium-48, which is not regulated as such 20-Jun-19 02:23 PM something something ion trapping something something can be cooled with low-cost diode lasers iirc 20-Jun-19 02:29 PM isn't that the double magic nucleus for heavy isotope production? 20-Jun-19 02:30 PM that too! 20-Jun-19 02:30 PM so there would be some production interest in enrichment 20-Jun-19 02:30 PM maybe enough to drive the price down 20-Jun-19 02:34 PM it's definitely an active field of research 20-Jun-19 02:41 PM sweet 20-Jun-19 02:41 PM Has any amateur ever done enrichment? 20-Jun-19 02:41 PM except for Deuterium of course 20-Jun-19 02:58 PM i think the only hobbyist-scale enrichment i've heard of so far is just deuterium 20-Jun-19 02:58 PM and that was mr. cody slab 20-Jun-19 02:58 PM he also ended up getting a Visit recently for all of his shenanigans in that space. i will never forget his uranium-ore-to-metal video where he starts by just taking it outside and smashing it up into dust with some metal pole thing 20-Jun-19 03:03 PM I'm sorry but that was just stupid 20-Jun-19 03:04 PM ok good i'm glad i'm not the only one that cringed at that 20-Jun-19 03:04 PM (ALTHOUGH i do still intend to taste a bit of my heavy water when i finally pop it open) 20-Jun-19 03:04 PM i have to know if it tastes sweet 20-Jun-19 03:06 PM I does 20-Jun-19 03:06 PM I've tried 20-Jun-19 03:06 PM :D 20-Jun-19 03:06 PM it's really weird 20-Jun-19 03:06 PM a chemical kind of sweet if that makes sense? 20-Jun-19 03:06 PM like an artificial sweetener? 20-Jun-19 03:06 PM doesn't taste like sugar, more like sweeteners 20-Jun-19 03:06 PM yep 20-Jun-19 03:06 PM hm ok 20-Jun-19 03:07 PM not unplesant 20-Jun-19 03:07 PM that sounds like it could make for a really interesting study in something like the kinetic isotope effect on taste receptors 20-Jun-19 03:08 PM I'd volunteer for that study 20-Jun-19 03:08 PM "Why does D2O taste sweet? Why does T2O taste metallic?" 20-Jun-19 03:10 PM maybe T2O is sweet and metallic. you could use it as a flavoring substitute for beryllium 20-Jun-19 03:10 PM >.> 20-Jun-19 03:10 PM I like the way you're thinking 20-Jun-19 03:10 PM lol 20-Jun-19 03:11 PM I think cody also tried water with heavy oxygen and didn't taste any difference 20-Jun-19 03:11 PM but I guess that's to be expected, since the mass difference isn't that big 21-Jun-19 03:22 AM yeah primary i want to enrich calcium 21-Jun-19 03:22 AM calcium 43 to be exact 21-Jun-19 03:22 AM i have a photo-selective process, but that is also a bottleneck 21-Jun-19 03:22 AM every higher order of enrichment of the metal in the oven would be awesome 21-Jun-19 03:22 AM And of course i want to try other (stable!!!11one) elements too 21-Jun-19 03:22 AM and yeah, poor cody btw 21-Jun-19 04:02 AM btw, what would be a good universal "enrichment" (i'm talking about micrograms) rig? 21-Jun-19 04:02 AM simply a sector analyzer? 21-Jun-19 04:12 AM i mean to get a few micrograms of an element, you would need a relatively high beam current in the mA range for a day or so? 21-Jun-19 04:12 AM + would we get in trouble with such a tiny enrichment rig? 21-Jun-19 04:31 AM I guess the easiest way at home would be a sector analyzer 21-Jun-19 04:31 AM but yeah, that's very slow 21-Jun-19 04:31 AM afaik enrichment is not illegal, but owning certain isotopes is 21-Jun-19 04:31 AM what do you want to do with the Ca43? 21-Jun-19 04:45 AM QC stuff 21-Jun-19 04:45 AM yeah micrograms are enough for me 21-Jun-19 04:45 AM enriched ion source in the oven makes the loading process faster 21-Jun-19 04:45 AM (since i don't have to handle the wrong isotopes) 21-Jun-19 04:59 AM quality control? 21-Jun-19 04:59 AM no, what's QC? 21-Jun-19 04:59 AM ah, i mean Quantum Computing 21-Jun-19 04:59 AM ahh 21-Jun-19 05:00 AM the isotope stuff needs to get atomized (thermically) 21-Jun-19 05:00 AM and then photoionized over an intermediate state (what can be used as a selector, since the nucleus of different isotopes shifts the frequency a bit) 21-Jun-19 05:00 AM but a lower rate of atoms per second makes the whole thing more manageable, so it's good if you've an enriched source 21-Jun-19 05:00 AM and if you want to know why 43Ca, it's because of its good reachable hyperfine doublet states 21-Jun-19 05:09 AM sweet 21-Jun-19 05:09 AM (quantum computing goes way over my head) 21-Jun-19 05:11 AM over mine too, but i don't care 21-Jun-19 05:11 AM That's the spirit 21-Jun-19 06:43 AM Should I help some random person on the internet build a calutron? Hmmm 21-Jun-19 06:43 AM It’s just a sector analyser (classic calutrons) but I wonder if a quadrupole would work better? No need for a magnet 21-Jun-19 06:52 AM To @N00N : may i ask what is the benefit (for quantum computing with ion trap) of using 43Ca instead of 40ca Ion ? And why thermal heat a CA powder in an oven with photoionization seems not so easy as you seems to mentioned ? 21-Jun-19 06:55 AM Home AVLIS 21-Jun-19 06:55 AM Oh by the way did you know you can just buy these on AliExpress? You don’t even have to take the smoke detector apart! 21-Jun-19 06:55 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-30C1D.jpg 21-Jun-19 06:58 AM By the way ... to @N00N what do you think of Chris monroe (IonQ) statement at last Nisq workshop : https://www.youtube.com/watch?v=-gzrbFk9Z64 « … in atomic physics we don't really take error correction very seriously yet because we don't need to the passive errors in atomic systems can be very very low may-maybe not low enough we don't know yet but I'm pretty sure that we can we can get pretty wide and deep circuits certainly well beyond quantum supremacy where you can't simulate the behavior of the system on any classical computer and I would say not unlikely even without error correction to be able to hit applications ... »(copy paste of the YouTube transcript) ... surprising talk , isn’t it !? 21-Jun-19 07:03 AM @a_quiet_scientist yep, they're on ebay, too. But at least in germany the activity is above the legal amount and since Am-241 is theoretically fissile they can really f you up 21-Jun-19 08:14 AM I thought 0.8 uCi sounded a bit low for a smoke detector! What’s the legal limit? 21-Jun-19 08:36 AM 10 kBq / ~0.3 uCi 21-Jun-19 08:36 AM ionisation detectors are illegal 21-Jun-19 08:36 AM no matter the acivity 21-Jun-19 08:36 AM many fun rules Like "if a house that had sn ionisation detector in it burns down and the detector can't be retrieved all of the rubble has to be discarded as contaminated waste 21-Jun-19 08:36 AM and that's ~30k per barrel 21-Jun-19 08:52 AM Gigasquirrel or [Gs] could be a measure unit 21-Jun-19 08:52 AM "My vacuum chamber reached 42 [Gs]" 21-Jun-19 08:52 AM "Now all squirrels are dead" 21-Jun-19 09:03 AM well it was gigabecquerel but someone could not read and so I changed it to what they thought it said 21-Jun-19 09:21 AM @yann35 43Ca because of the stable hyperfine clock states 21-Jun-19 09:21 AM @a_quiet_scientist yeah i guess a calutron would be nice 21-Jun-19 09:21 AM @yann35 i guess he (Munroe) is right? 21-Jun-19 09:21 AM Monroe 21-Jun-19 10:17 AM those aliexpress/ebay 241Am sources kinda wig me out, 'cos -- for US folks -- they're definitely over the NRC exempt source limi; they're not listed here https://www.nrc.gov/reading-rm/doc-collections/cfr/part030/part030-0071.html and considering it's an alpha-emitting byproduct material i don't know if any amount is legal to have 21-Jun-19 10:17 AM ionization smoke alarm manufacturers have a general license to use the stuff in their products 21-Jun-19 10:17 AM IANAL but i do not advise 21-Jun-19 10:17 AM ... but TIL up to a millicurie of tritium is exempt. huh 21-Jun-19 11:54 AM @a_quiet_scientist would you help me building a calutron? 21-Jun-19 04:20 PM you could see if this could be adapted to your needs @N00N https://oup.silverchair-cdn.com/oup/backfile/Content_public/Journal/ptep/2015/3/10.1093_ptep_ptv020/4/ptv020.pdf?Expires=2147483647&Signature=IxPWj7SXqtHaA0O3CoIghhKJ-UUBkNIKFwmXwt2C7JYPexRd0sgJ1ssnqGfixZMrNmUo7p~p359OKXc4nbHA3CkHTnJSiOwCrjG0k8Q0ZOL6q7KsVJfFxRSCbkxR595sBz-NGeHjVLGKBRh9nwakfTrg3xv-lEy95Tv5XjSMSWQVB2zstV~qZl8keDye6PbO~8vb0cGro1b3OBeo49CJOt2DsWFUGudMZFRmfCd7-pSTFq1fzHJh-TsMMn0sa~hC4NrPw5Ud-B6gBzrJDHF30Oiu4fzxZDGIg1rdKtvsvSdkXLKrp-SHGyGsgFethIKpKhwBy5jcbJcsI3k1nB1k4w__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA 21-Jun-19 04:20 PM apologies for huge url :D 21-Jun-19 06:26 PM OK so what do you need? (a) vacuum chamber, pumps and vacuum gauge (b) ion source with the material desired (c) large drift region and huge magnet and (d) collector cups or some sort of detector such as a MCP or fluorescent plate so you can aim the beam 21-Jun-19 06:26 PM https://link.springer.com/chapter/10.1007/978-3-7091-5087-0_11 21-Jun-19 06:26 PM I think a quad will be easier 21-Jun-19 06:26 PM https://aip.scitation.org/doi/10.1063/1.1143286 21-Jun-19 11:26 PM @qualia ah nice 21-Jun-19 11:26 PM @a_quiet_scientist so is there any advantage of a calutron left? 21-Jun-19 11:26 PM i mean for ion implantation magnetic diplole analyzers are still in use 21-Jun-19 11:26 PM for i dunno ion beam optikal reasons? 21-Jun-19 11:26 PM optical 22-Jun-19 08:06 AM ping? 22-Jun-19 03:20 PM would it be bad to have a shop-vac hooked up to my rough pump exhaust? 22-Jun-19 03:21 PM uhm.... why would you even want to do that? 22-Jun-19 03:21 PM I would want to say yes since you'd cover the inside of your vacuum in roughing pump oil 22-Jun-19 03:21 PM aka mineral oil 22-Jun-19 03:21 PM and it would probably cause fire in the vacuum's motor through arcs and sparks 22-Jun-19 03:21 PM basically I have a big air extractor on the outside of my garage, which I use to pull out laser cutter fumes, and since I already have an insulated pass-through in the window for this, I figured I could just get a TEE and add the rough pump exhaust into it... so there's no chance of breathing oil vapor 22-Jun-19 03:22 PM oh hrm... air extractor and a vacuum cleaner are two different things 22-Jun-19 03:22 PM I could of course, just not turn on the outside vacuum if I was using my FIB/SEM 22-Jun-19 03:22 PM eh, it pulls a good "vacuum" 22-Jun-19 03:22 PM I would think through an air extractor you probably have enough air flow it would be diffused enough not to be a problem 22-Jun-19 03:22 PM I dunno, the inside of that extraction tube would probably slowly still get covered in oil 22-Jun-19 03:23 PM https://www.harborfreight.com/13-gallon-industrial-portable-dust-collector-31810.html 22-Jun-19 03:23 PM like I don't think it will hurt the motor or anything 22-Jun-19 03:23 PM but stuff is going to get covered in oil over time 22-Jun-19 03:24 PM I'm not too concerned with that really, at least not at this time 22-Jun-19 03:24 PM worst case the oil would cause particles from the laser cutter to stick, causing the motor to work harder or CFMs to drop 22-Jun-19 03:24 PM as-is I was planning to use a dimmer switch on the thing to "turn it down" 22-Jun-19 03:25 PM well and just cause you to have to clean the piping and stuff out over time 22-Jun-19 03:25 PM eh, it's 4 in HVAC pipes 22-Jun-19 03:25 PM I mean its not a big deal just maintenance 22-Jun-19 03:25 PM clean that when I die 22-Jun-19 03:25 PM lol 22-Jun-19 03:28 PM I think for now I'll give it a shot, will install a damper on each side of the TEE (to rough pump, to laser cutter) and then I should be able to modulate things a bit 22-Jun-19 03:28 PM start with outside extractor turned off 22-Jun-19 04:46 PM @tmbinc wow your blog post on the NV2 camera is really impressive! I figure that would have taken me a few years (before I had a kid... now it seems like probably triple the time) 22-Jun-19 04:48 PM I'm still trying to work out the data loss 22-Jun-19 04:48 PM I'm waiting on an FX2 board to come in 23-Jun-19 05:51 AM @GigaSquirrel + i need a ion gun design for Ca 23-Jun-19 05:52 AM I have absolutely no Idea whatsoever about ion guns 23-Jun-19 05:52 AM heh like me 23-Jun-19 05:52 AM but as always 23-Jun-19 05:52 AM i don't care 23-Jun-19 05:53 AM xD 23-Jun-19 05:54 AM the most productive calcium isotope separation facility is in Lesnoy, Russia 23-Jun-19 05:54 AM according to professor poliakoff 23-Jun-19 05:55 AM https://www.gsi.de/work/beschleunigerbetrieb/beschleuniger/ionenquellen/sources/ion_sources.htm 23-Jun-19 05:55 AM knowing the guys from the GSI just calling them and asking might actually work 23-Jun-19 05:56 AM ah nice idea 23-Jun-19 05:56 AM and damn they are sexy 23-Jun-19 05:57 AM in lesnoy they are mostly interested in the magic 48Ca for nucleo synthesis 23-Jun-19 05:57 AM double magic (20p and 28n) 23-Jun-19 05:57 AM yep 23-Jun-19 09:13 AM Joined the server. 23-Jun-19 05:36 PM My rough pump exhaust tube solution (existing hole goes out window for laser cutter exhaust) 23-Jun-19 05:36 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190623_173309_exported_5597534188311-287A7.jpg 25-Jun-19 08:45 AM @Applied_Ion you were proposing metal baseplates for bell jars, any tips on aluminum plate selection? 25-Jun-19 09:19 AM Metal baseplates are standard. Aluminum is perfectly fine. I used ATP-5 since it comes with a default surface finish of 25 micro inch or better, where the standard surface for o ring mating for vacuum is 32 micro inch or better. I went 1" thick to have enough thread engagement for bolts, as well as rigidity for mounting and thermal dissipation 25-Jun-19 01:29 PM Is there a good place to go for these measurement standards listed? 25-Jun-19 01:29 PM Or is that professional experience speaking 25-Jun-19 01:32 PM From lots and lots of background reading and research into the field. Numbers pop up but they aren't everywhere unfortunately lol 25-Jun-19 01:34 PM Fair 25-Jun-19 09:15 PM bad idea? https://www.ebay.com/itm/Acrylic-Vacuum-Bottom-Draw-Bell-Jar-20-dia/283467554722?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649 25-Jun-19 09:15 PM seems pretty big, would be worried about implosion risk without a cage 25-Jun-19 09:15 PM idk how bad acrylic is for outgassing, or whether I could coat the inside with something that will outgas less 25-Jun-19 09:15 PM "Acrylics have high outgassing rate and high affinity to water." - wikipedia 25-Jun-19 09:17 PM Depends on how deep of a vacuum you want 25-Jun-19 09:17 PM How far you looking to go? 25-Jun-19 09:18 PM I have a diffusion pump, and I'm looking to do resistive evap 25-Jun-19 09:18 PM So like 10^-5 torr or so? 25-Jun-19 09:18 PM yeah 25-Jun-19 09:19 PM You can do a rough calculation to estimate your operating conditions 25-Jun-19 09:19 PM What is your vacuum pump speed? 25-Jun-19 09:19 PM one sec 25-Jun-19 09:19 PM my backing pump can do 8 CFM, and I think the diffusion pump is rated for 5 CFM backing 25-Jun-19 09:22 PM What's the speed of the diffusion pump 25-Jun-19 09:23 PM sorry I'm trying to find it, it's in a non-OCRed PDF 25-Jun-19 09:23 PM 720 L/s according to you-in-the-past 25-Jun-19 09:26 PM In the meantime, here are some outgassing rates for acrylic in torr-l/s/cm^2: 1hr = 2×10^-6 10hr = 1×10^-6 24hrs = 5×10^-7 Baked/pumped = 1×10^-8 25-Jun-19 09:26 PM What's the size of the bell jar? If you know the surface area, you can use that to calculate ultimate pressure for a given vacuum level based on gas load 25-Jun-19 09:27 PM 1300 square inches 25-Jun-19 09:27 PM sorry 25-Jun-19 09:27 PM 650 25-Jun-19 09:27 PM forgot to divide by 2 25-Jun-19 09:28 PM Ok, so about 4194cm^2 25-Jun-19 09:28 PM 4200 cm^2 25-Jun-19 09:28 PM yea 25-Jun-19 09:28 PM Yeah lol 25-Jun-19 09:28 PM Are you using a baffle or trap above the pump? 25-Jun-19 09:29 PM I probably will, but I haven't designed enough of the system yet 25-Jun-19 09:29 PM I don't have one yet 25-Jun-19 09:29 PM Well we can estimate for both cases. Assume with a good trap you have about 65% of the pump speed 25-Jun-19 09:30 PM so torr-l/s/cm^2 means you multiply by area and divide by (pressure * pumping speed) I guess 25-Jun-19 09:31 PM So for a rough estimate, P=Q/S 25-Jun-19 09:31 PM or oh wait you're trying to find the pressure 25-Jun-19 09:31 PM Q is gas load, so in this case assume ideal with just multiplying load of acrylic by surface area 25-Jun-19 09:31 PM so you don't divide by pressure 25-Jun-19 09:32 PM Then divide by speed to get the ultimate pressure you can reach for thst gas load and speed 25-Jun-19 09:32 PM (2 * 10^-6) * 4200 / 720 torr 25-Jun-19 09:32 PM in worst case 25-Jun-19 09:34 PM Yeah, so you are looking at about 1.17 x 10^-5 torr 25-Jun-19 09:34 PM However, this is only the load from the chamber 25-Jun-19 09:35 PM I guess there is vapor pressure from diffusion pump oil? 25-Jun-19 09:35 PM Doesn't include the baseplate, oil backstreaming (not negligeable without a trap), and your process gas 25-Jun-19 09:35 PM everything else will be stainless steel or aluminum 25-Jun-19 09:35 PM Yes, depending on the oil you use 25-Jun-19 09:35 PM Well, all oils have it 25-Jun-19 09:35 PM Some are much better than others 25-Jun-19 09:35 PM probably DC-704 25-Jun-19 09:36 PM So you will definitely have some with that oil at least. A baffle should be used at least 25-Jun-19 09:36 PM So is your ultimate pressure goal 10^-5 torr, or is that your process pressure? 25-Jun-19 09:36 PM Rough rule of thumb is that ultimate pressure achievable should be an order of magnitude lower than process pressure 25-Jun-19 09:38 PM well I haven't really thought that far ahead frankly 25-Jun-19 09:39 PM Once the heaters start going and you start evaporating metal that will add an additional gas load that will increase pressure during the process, unless the system has enough overhead 25-Jun-19 09:39 PM Oh yeah almost forgot, another gas load to account for is the oring 25-Jun-19 09:39 PM The larger the oring, the more load 25-Jun-19 09:40 PM ah yeah I meant to ask about that, so I guess I can't just use a silicone gasket then? 25-Jun-19 09:40 PM You will want to add both outgassing and permeation loads for the oring 25-Jun-19 09:40 PM You can, but you won't probably won't hit 10^-5 torr with that large of a seal 25-Jun-19 09:42 PM making a groove for an o-ring to ride in will complicate things (I don't think there's a machine shop near me that will be able to chuck a 20" aluminum plate on a lathe lol) 25-Jun-19 09:43 PM http://www.vacuumcursus.nl/casussen/Vacuum_Systems_UHV.pdf 25-Jun-19 09:43 PM this has outgassing rates for a lot of common materials for reference 25-Jun-19 09:43 PM thanks, this seems useful 25-Jun-19 09:43 PM wouldnt need a lathe could just be CNC, thats how my plates were done 25-Jun-19 09:44 PM ah good point 25-Jun-19 09:44 PM there are standard dimensions for vacuum o-ring seals you will want to make sure to spec your groove to for a given o-ring size 25-Jun-19 09:45 PM are there like OCW/edX/whatever lecture videos online about this stuff? I've been watching some on semiconductor stuff and it's been great. I don't have much trouble reading papers and textbooks but I find it more relaxing to watch a lecture 25-Jun-19 09:45 PM for a large bell jar like that, it may have to e clamped down to compress the oring in the groove to be more effective 25-Jun-19 09:45 PM no videos really lol, the best info is in the older textbooks 25-Jun-19 09:46 PM can you link a good textbook? 25-Jun-19 09:48 PM yeah I can get you some titles I use. Note though that some of these go way deep into vacuum engineering lol 25-Jun-19 09:48 PM here is a reference for o-ring groove sizes: 25-Jun-19 09:48 PM http://www.row-inc.com/sizes.html 25-Jun-19 09:48 PM ideally you will want to spec the surface finish of the groove to at least 32 micro-inch 25-Jun-19 09:50 PM so like down to 2000 grit then polished? 25-Jun-19 09:51 PM this place also has an excellent amount of articles on vacuum engineering, definitely recommend looking through them: 25-Jun-19 09:51 PM http://www.normandale.edu/departments/stem-and-education/vacuum-and-thin-film-technology/vacuum-lab/articles 25-Jun-19 09:51 PM I remember at the metallography lab I did some stuff in we got down to 0.3 micron surface roughness with that 25-Jun-19 09:51 PM but for a complex shape like a groove idk if that's sufficient 25-Jun-19 09:52 PM groove doesnt need to be complex, regular rectangular shape is fine 25-Jun-19 09:52 PM I just meant "more complex than a plane" 25-Jun-19 09:52 PM oh lol yeah 25-Jun-19 09:53 PM this site looks great, thanks 25-Jun-19 09:53 PM here are the books I have used for reference: 25-Jun-19 09:53 PM 1.) Fundamentals of Vacuum Science and Technology - Gerhard Lewin, 1965 2.) Introduction to the Theory & Practice of High Vacuum technology - L. Ward, J.P. Bunn, 1967 3.) Handbook of High Vacuum Engineering - H. A. Steinherz, 1963 4.) Practical Vacuum Systems - Rolland Rutledge LaPelle, 1972 25-Jun-19 09:53 PM found used either on Amazon or Abebooks 25-Jun-19 09:55 PM any of them on libgen? 25-Jun-19 09:55 PM though I have also downloaded a lot of other reference papers and materials as well. I think I posted a very large vacuum folder of all my papers somewhere early in the Resources area here 25-Jun-19 09:55 PM idk lol, never looked 25-Jun-19 09:57 PM none of them on libgen 25-Jun-19 09:57 PM I found #1 on ebay for $14, just bought it 25-Jun-19 09:57 PM might scan it lol 25-Jun-19 09:58 PM I ended up getting them pretty cheap, only a few dollars each. Though the Normandale College link has excellent articles 25-Jun-19 09:58 PM https://archive.org/details/HighVacuumTechnology 25-Jun-19 09:58 PM some great person uploaded this one to archive.org 25-Jun-19 09:59 PM nice lol 25-Jun-19 09:59 PM #1 and #2 go into the more heavy theory stuff, #3 is a good longer general reference book, and #4 is a good top-level overview 25-Jun-19 10:00 PM cool 25-Jun-19 10:00 PM if I can find #4 I'll check it out, but I have #3 downloaded now 25-Jun-19 10:02 PM Ah, speaking of grooves, here you go. From #4: 25-Jun-19 10:02 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20190626_010210-F6806.jpg 25-Jun-19 10:02 PM I've got all the major stuff marked with color coded sticky notes, makes it fast to find info lol 25-Jun-19 10:02 PM sorry picture isnt that great, you will need to zoom in on the original to read it 25-Jun-19 10:06 PM yeah I checked it out 26-Jun-19 10:03 AM @Applied_Ion is "polished" a meaningful term in aluminum grading for these systems? 26-Jun-19 10:13 AM Polished can have a wide variety of meanings. If you are specifying plates for manufacture, you will want to use actual surface roughness numbers. 26-Jun-19 10:13 AM 32 micro inch is standard for o ring interfaces 26-Jun-19 11:41 AM Though polishing probably in general surpasses that roughness 26-Jun-19 04:19 PM Interesting 26-Jun-19 04:19 PM I had a feeling 27-Jun-19 01:24 AM Are you sure you don't mean milli inch? Aka thousandths? When i looked up the ATP-5 it just said something stupid like "RMS 20-30" and i didn't see anything about micro 27-Jun-19 01:34 AM Yes, RMS is measured in micro inches 27-Jun-19 01:34 AM So that is a root mean square of 20-30 micro inch for peaks and valleys 27-Jun-19 01:34 AM General overview on the subject: https://www.destinytool.com/surface-finish.html 27-Jun-19 01:34 AM RA is more common now, but RMS is a more typical and cited reference for vacuum finishes 27-Jun-19 02:10 AM Actually even in the page I took a picture of above, you can see it states 32 rms finish. This number has also appeared in other vacuum texts and nasa references for vacuum chamber sealing standards 27-Jun-19 02:10 AM Other interfaces will have different tolerances though. For example, a rotary vacuum feedthrough using an oring usually requires a finish of 15 rms 27-Jun-19 04:00 AM To @N00N : do you know a good free tool to simulate the geometry surface of an ion trap? I know Simion but it cost 1200 € ! Thanks ( Yann an Ion trappers) 27-Jun-19 08:46 AM So now I wait for the bossman to flip a coin between a slab of ATP-5 and my machining it, vs buying a $2.2k unit fully furnished from Kurt J Lesker 27-Jun-19 08:46 AM Thanks for the input on a cheap option @Applied_Ion 27-Jun-19 01:14 PM Woah, Lesker lead times are no joke. 10 weeks!? 27-Jun-19 01:16 PM @tokyodrip np lol 27-Jun-19 01:16 PM And yeah, vacuum lead times for custom stuff can be long, that's not unusual 27-Jun-19 01:28 PM Well LDS Vacuum balked at 10 weeks, so hopefully that wasn't arrogance. I'm drawing up a design for their engineer to give an estimate on 27-Jun-19 01:52 PM LDS is a bit different from the big companies like Lesker, Ancorp, etc 28-Jun-19 04:15 AM Do you know a good free tool to simulate the geometry surfaces of an ion trap? I know Simion but it cost 1200 € ! Thanks 28-Jun-19 04:40 AM Not sure there are many free ion trajectory simulation softwares out there. You can get a 1 year license of Simion for like $600 I think. Still not cheap, though if you will be using it a lot it may be best to get the indefinite license. 28-Jun-19 10:28 AM @yann35 maybe this? http://ibsimu.sourceforge.net/ 28-Jun-19 11:06 AM ibsimu is quite powerful, but it is focused primarily on extracted ion beams from plasmas (which is something that SIMION actually lacks, and was built specifically for ion extraction from plasmas). It is also extremely difficult to get installed and running properly. 28-Jun-19 11:20 AM Maybe something with FENICS? 28-Jun-19 11:20 AM Searching '"fenics" ion trap' shows some articles 28-Jun-19 06:22 PM @AdamMcCombs is there a good primer or guide to cleaning SEM columns? Aside fron use gloves, kimwipes, acetone, aluminum foil? 28-Jun-19 07:46 PM @nmz787 I haven't found a good guide. A lot of it comes down to polishing compound+decontamination method and knowing the gotchas of different columns that will bite you. Do you have reason to embark on a column cleaning? FIBs also have a lot more consumables than SEMs 28-Jun-19 07:46 PM A good ultrasonicator is a must. 28-Jun-19 07:53 PM I like LDS because they gave me a tour and a reusable shopping tote 28-Jun-19 08:12 PM @AdamMcCombs was thinking about you mentioning my SEM sounded like a vacuum issue vs electronic 28-Jun-19 08:12 PM And that i should start with cleaning the column before trying the fib 28-Jun-19 08:27 PM That was with the assumption that there was a full set of alignment/service docs like the 200... 28-Jun-19 08:27 PM SEM is a different story. That's easy enough to do and will improve resolution 28-Jun-19 08:27 PM On the SEM I would have to see what it looked like, but if you are getting a image deflection that is ancillary and different than stage move directions that is usually a vacuum issue as the beam will ionize gas molecules that will act like charge neutralizers and cause beam deflection 28-Jun-19 10:58 PM Joined the server. 28-Jun-19 11:01 PM Welcome! 28-Jun-19 11:03 PM Thanks 28-Jun-19 11:03 PM Lots of interesting discussion to read back on 30-Jun-19 05:16 AM hi 30-Jun-19 05:16 AM @yann35: well comsol ... but we're using our own "FDTD" solver 30-Jun-19 05:16 AM for the optimization of ion trap electrode configurations 30-Jun-19 06:06 AM Thanks for the replies @N00N & others ... Comsol is not cheaper than Simion (according to my discussion with their sales ). It’s around 10x the price of Simion ... 30-Jun-19 10:29 AM I found this procedure : Venting a Vacuum Chamber https://www.instructables.com/id/Venting-a-Vacuum-Chamber/ . Sounds good to me but what is your opinion as expert ? 30-Jun-19 10:32 AM I don't see the point of using LN2 to vent it, as it would surely introduce condensation? 30-Jun-19 11:52 AM I think I heard something about that, I think something to do with LN2 being a more pure nitrogen source 30-Jun-19 11:52 AM Ugh, I think I may have to potentially gear up for a fight on the fusor forums about pulsed power with some of the old guard. 30-Jun-19 11:55 AM https://giphy.com/gifs/reactiongifs-tyqcJoNjNv0Fq 30-Jun-19 11:56 AM Lol 30-Jun-19 11:58 AM but don't you remember how [insert old member here] did something that vaguely related to something somewhat similar to the topic on hand and it worked-ish and so this is the way to do it? Keep in mind you're just young and don't have the experience that Mr. Hull and futter ye olden members have! 30-Jun-19 12:01 PM Lol yeah we will see how it goes. I have been mentoring Joshua Guetler on pulsed power applications to fusors as he is interested in tackling a pulsed fusor, and started a new thread recently about it on the forums. Already they are jumping in saying not to do it at the amateur level and it is too difficult and expensive 30-Jun-19 12:01 PM Nonsense lol 30-Jun-19 12:01 PM Pulsed power is the key to research class outputs at home on our limited budgets! 30-Jun-19 12:02 PM yeah, I've got the thread open right here 30-Jun-19 12:02 PM tbh I was surprised you didn't chime in earlier 30-Jun-19 12:03 PM I only just saw it like today lol 30-Jun-19 12:03 PM I try to avoid conflict where I can, but when it comes to certain stuff like pulsed power it's one area I gotta defend lol 30-Jun-19 12:04 PM any opinions on rowleys I-Pinch? 30-Jun-19 12:08 PM I think it's good someone is doing pulsed plasma. I haven't seen much about that particular pinch device, very uncommon type of pinch device 30-Jun-19 12:14 PM It's interesting to see that other pulsed stuff is welcome, but pulsed fusors are not encouraged lol. They are literally just ion diodes, though if it were me I'd rather build a classic high power ion diode like the PBFA II before it became the z-machine 30-Jun-19 12:22 PM you keep calling them diode, do they really have a polarity dependant behaviour? 30-Jun-19 12:22 PM or is the name just because of the two connections, not the electrical component 30-Jun-19 12:29 PM In terms of vacuum diodes for accelerating electrons or ions, it is a current flow between two electrodes. For the fusor, still the same principle, specifically for ion current flow. Why else would the outer grid require positive polarity relative to the inner? Demo fusors in bell jars often use grounded inner grid and positive outer since it is easier, but fusion fusors use grounded outer and negative inner for safety. In either case polarity between the two electrodes is the same to accelerate the ions towards the central region. 30-Jun-19 12:29 PM The current flow of ions in the fusor is essentially one direction, making it an ion diode by strict definition 30-Jun-19 12:30 PM I know the devices need the right polarity to work at all, but my question was more... electrical. If you could use the a fusor as a rectifier 30-Jun-19 12:31 PM Oh lol, idk that's a good question. Usually though rectifier tubes are electron diodes, not sure it would work the same with an ion diode 30-Jun-19 12:31 PM Though I guess if you reversed polarity and drew a deeper vacuum to limit background gas, yeah I think it could work 30-Jun-19 12:31 PM I think "diode" literally just means two electrodes, and it only has the connotation of rectification because of the vacuum tube 30-Jun-19 12:32 PM Well, even in this case current flow is still essentially in one direction, though in this case you do not use them for rectification 30-Jun-19 12:32 PM Diodes are not necessarily only for rectification, though thst is by far the most common implementation in modern semiconductor devices 30-Jun-19 12:34 PM until someone builds a step recovery ion diode I'm going to call them rectifier 30-Jun-19 12:34 PM For example, DSRDs, which I have touched upon extensively before, are special solid state diodes in pulsed power specifically for generating ultrafast high peak power ns pulses, not for rectification 30-Jun-19 12:34 PM Actually, even DSRDs operate using a plasma phenomenon, makes them quite unique and interesting semiconductor devices 30-Jun-19 12:36 PM ...damn it 30-Jun-19 12:36 PM Lol 30-Jun-19 01:45 PM @Applied_Ion that paper you linked in the fusor forum post states that the Q of an IEC device is only dependant on the neutron output, but not the proton output. there is no mention on why they ignore the protons, do you have any Idea about that? 30-Jun-19 01:45 PM an also off, those conclusions are a bit... optimistic 30-Jun-19 02:22 PM I don't know about the nuclear side - all I know is the pulsed power supply is not some mythical contraption. 30-Jun-19 02:22 PM but it seems like the fight has started lol 30-Jun-19 02:25 PM hahaha 30-Jun-19 02:25 PM I think this is part of the reason why pulsed power is so inaccessible for those interested in starting - too much mysticism by the old folks in it. Yeah, it needs a lot of hands on tinkering and stuff never works the way its designed, but historically it has always been like that. Build stuff from scrap, tinker a bit until it catches fire or works somewhat right lol. But the actual circuits used are dirt simple, just operating at much higher voltages and currents than average 30-Jun-19 02:26 PM yep 30-Jun-19 02:26 PM ahh, his answer is just wonderful 30-Jun-19 02:26 PM IMO this translates to "I do not understand this paper and it is not a step by step instruction, so it has no place in this forum" 30-Jun-19 02:34 PM yeah... 30-Jun-19 02:34 PM if it didn't hurt the community so much it would be a great laugh 30-Jun-19 02:39 PM it is irritating to deal with this level of ignorance. Normally I'd let it go, but again as an advocate for amateur efforts in pulsed power, I can't just put it down without a fight 30-Jun-19 02:39 PM everyone needs to start somewhere, no need to go hard core with some massive supply. A super small and simple one can be built dirt cheap and easy 30-Jun-19 02:39 PM just needs some hands on experience to work your way up 30-Jun-19 02:43 PM yep 30-Jun-19 02:43 PM I guess most people get scared when they read MV/ MA / MW 30-Jun-19 02:43 PM and maths 30-Jun-19 02:43 PM you can build a fusor literally without calculating anything, but there's no way you do that with a pulsed system 30-Jun-19 02:46 PM eh, you can still get away with it in a pulsed system lol 30-Jun-19 02:46 PM an optimized pulsed system needs calculation, but you can get impressive outputs without much effort 30-Jun-19 02:46 PM well, my response is sent 30-Jun-19 02:46 PM their move 30-Jun-19 02:47 PM oh my 30-Jun-19 02:47 PM one day someone will publish a book, every page being one of your answers 30-Jun-19 02:47 PM hey, I've got a thyratron just like this right beside me 30-Jun-19 02:47 PM got it for 20 bucks 30-Jun-19 03:01 PM and you can use a spark gap switches instead if needed 30-Jun-19 03:01 PM thyratrons are a dime a dozen on ebay, its a load of crap 30-Jun-19 03:01 PM you dont need deuterium tube diodes either lol, we use just chains of generic semiconductor ones at far higher powers and rep rates than in the paper 30-Jun-19 03:01 PM absolutely unimaginative bunch of old guys who clearly don't know how to scrounge and make stuff beyond just the basic fusor 30-Jun-19 03:03 PM yeah I never really got that 30-Jun-19 03:03 PM so often I see Q calculations for IECs 30-Jun-19 03:03 PM and everyone optimates for Q if they optimate at all 30-Jun-19 03:03 PM but... why?! 30-Jun-19 03:03 PM do people really think that IEC is the way for breakeven? 30-Jun-19 03:05 PM ik lol, it is a great low-cost neutron source, but not energy. Why optimize for that when more work can be done to make it a valuable laboratory neutron generator 30-Jun-19 03:07 PM that also bothers me about the paper 30-Jun-19 03:07 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-1F3A8.png 30-Jun-19 03:09 PM I think they are over optimistic about break even, but they are after it as a energy source rather than neutron source. The way I see it, achieving in the upper 10^8 n/s range with a reasonably simple supply more than justifies efforts in this area to improve nuetron yields for home-based fusors 30-Jun-19 03:10 PM it really does justify it 30-Jun-19 03:10 PM just not if you're going after break-even, as I said 30-Jun-19 03:10 PM hell, people have built betatrons, cyclotrons and whatnot at home, but pulsed power? No way! 30-Jun-19 03:13 PM ik, god forbid! a pulsed fusor is simply unacceptable and far too archaic for any amateur to make! 30-Jun-19 03:13 PM im going to start posting pictures of my pulsed power stuff I have built with trash that cost me nothing. Charging chokes, pulse transformers, spark gap switches, etc 30-Jun-19 03:15 PM you'll be told that takes up too much space 30-Jun-19 03:20 PM I already have a complete thyratron pulser that can be used to drive a fusor lol. Its the one I use for testing my thrusters and is quite compact 30-Jun-19 03:20 PM I just dont have a fusor, otherwise I would have driven it by now 30-Jun-19 03:22 PM why not? 30-Jun-19 03:26 PM im too stretched for resources between thrusters and the accelerator lol 30-Jun-19 03:26 PM I also don't have much interest in fusors, there are much more tantalizing systems out there. However, I may just bang one together just to shut these old guys up. Can't afford to run it on deuterium at the moment though 30-Jun-19 03:28 PM ah well 30-Jun-19 04:38 PM new response almost typed out lol 30-Jun-19 04:38 PM got loads of pictures prepped to show how simple and cheap pulsed power parts can be made 30-Jun-19 05:04 PM well its up lol 30-Jun-19 05:15 PM come into my house saying pulsed power is not worth trying and you will be in a world of hurt lol. The old guard may be cowards when it comes to it, but maybe the new generation of experimenters will try some stuff that hasn't been done before. 30-Jun-19 05:15 PM And it helps no one to discourage others efforts. Everyone needs to start somewhere. 30-Jun-19 05:15 PM Ok hopefully rant is over lol 30-Jun-19 10:30 PM not going to buy this, but what is a "mechanical booster pump"? https://www.ebay.com/itm/C116370-Edwards-EV100-Rotary-Vane-Vacuum-Pump-EH1200-Mechanical-Booster-Pump/293105493108?hash=item443e72e474:g:cZIAAOSwkoVc4ylM 30-Jun-19 10:30 PM does it just increase flow rate or something 30-Jun-19 10:37 PM it's usually an additional stage to get more compression and lower base pressures 30-Jun-19 10:37 PM the one i worked with, you can actually hear the second stage rev up and see the pressure go down accordingly, it's pretty cool 30-Jun-19 10:42 PM oh so it's just an old-fashioned version of a dual rotary vane pump? 30-Jun-19 10:42 PM or does it go lower? 30-Jun-19 10:52 PM not sure if it goes lower, but google tells me the EV100 is a single stage, and the EH1200 is a roots blower 30-Jun-19 10:52 PM iirc the advantage between this and a similar dual stage vane pump is probably just the larger flow 30-Jun-19 10:52 PM definitely made for bigger chambers at least 30-Jun-19 11:07 PM hmm I found 2 residual gas analyzer sensor heads for $100 and a controller for a very similar model for $60 30-Jun-19 11:12 PM Yeah that's usually for massive chambers like big PVD setups or some massive semiconductor process. They pretty drastically improve pump down speed in big systems. 01-Jul-19 02:27 AM I thought they were anti step by step instructions, not criticising things because they are not step by step instructions? There’s no arguing with them. 01-Jul-19 02:29 AM yep... 01-Jul-19 10:36 AM Yeah... well hopefully others will see the absurdity of not trying and the benefits if you want to push into more serious neutron/s numbers. Nothing magical or special about the fusor vs any other vacuum load. Probably much easier to drive than other loads like klystrons. The fact remains that the physics is there and does not change just because the old guys only do it one way: higher voltages (to an extent) and higher currents will lead to more output. It's just that pulsed power has an advantage that it can generate the currents at the high voltages needed to push it further. You are pretty maxed out at the 100kv level for reasonable operation. But that's mA of current DC. Imagine the increase in rate when you are operating at orders of magnitude higher currents though - 1A, 10A, 100A - all achievable without that much investment. 01-Jul-19 12:32 PM I've been thinking about it more, and I am going to start working on getting EXEDA running. I will pump it down connected to the propulsion chamber so I don't have to switch out the big chambers or anything, and will make it faster to experiment with both systems. 01-Jul-19 12:32 PM I can also drive it at voltages theoretically as low as 25kV, so I will just build a 30kV blumlein cable pulser and drive it like I have done for the linac gun at work, and build up voltage and power over time. 01-Jul-19 12:32 PM Get prepared to be inundated with a boat load of details and data on pulsed accelerators in addition to new propulsion stuff. 01-Jul-19 02:29 PM /excited geiger counter noises/ 01-Jul-19 02:29 PM can't wait to see the accelerator! 01-Jul-19 02:30 PM For all the hype, you may be very disappointed how stupid simple it is lol. Like it is underwhelming simple in construction. 01-Jul-19 02:32 PM which makes it very easy to build 01-Jul-19 02:32 PM But I think it is time to start getting the ball rolling and sharing info on it. It's still not built or finished, but I can get beam without the full pulsed power driver 01-Jul-19 02:32 PM Yes lol 01-Jul-19 02:32 PM Just wait to see the experiments you can do with it though 01-Jul-19 02:33 PM what's the energy goal here? 01-Jul-19 02:33 PM for the first test atleast 01-Jul-19 02:34 PM Lasers, xrays, microwaves, oh my! 01-Jul-19 02:34 PM Like 30kev 01-Jul-19 02:34 PM cute :D 01-Jul-19 02:35 PM I will use a simple blumlein cable pulser using RG8 coax 01-Jul-19 02:35 PM Probable can get 100A beam with that at least 01-Jul-19 02:35 PM instant sun tan! 01-Jul-19 02:36 PM Since the primary stage of my main driver is built, I can drive it to maybe 100-200kv at several hundred amps min 01-Jul-19 02:36 PM I hope you have really good shielding AND dosimetry 01-Jul-19 02:37 PM Yeah that's why I'm starting small lol 01-Jul-19 02:37 PM that will give off quite some dose, even into a low z dump 01-Jul-19 02:39 PM Dose actually isn't really all that much. At ideal power in a regular dump, maybe 1 CT scan per pulse next to it? Actual direct beam dose would be absurdly high, but that's only in the chamber. 01-Jul-19 02:39 PM Not that I will stand next to it ever lol, and only operate it single shot 01-Jul-19 02:40 PM I thought you were above using "CTs" and "X hours of flight" as units of dose :P 01-Jul-19 02:41 PM Lol since when. Only when talking about maybe electronics dosing we may need to go to higher number references 01-Jul-19 02:42 PM but how much is one CT scan? 500 uSv, 1 mSv, maybe even 50 mSv? 01-Jul-19 02:42 PM or will you strap a detector on your shirt and make an actual CT? :P 01-Jul-19 02:43 PM Idk, just a guess looking at some similar but more high power machines I have seen for reference. 01-Jul-19 02:43 PM Not me, but maybe a chicken from Walmart lol 01-Jul-19 02:44 PM :D 01-Jul-19 02:44 PM at least get a film badge dosimeter 01-Jul-19 02:45 PM Though the real interesting thing will be fast xrays of high speed phenomenon 01-Jul-19 02:45 PM and literal tonnes of lead 01-Jul-19 02:45 PM Oh yeah I will get at least a pen dosimeter 01-Jul-19 02:45 PM Eh, you don't need that much lead for 300kV xrays 01-Jul-19 02:45 PM But that's a long way away 01-Jul-19 02:46 PM well, you don't need much lead to half their number, but you need a lot of you half the dose rate still is 32 times too high 01-Jul-19 02:47 PM Less than 100kv is more where I will be for a while at lower current 01-Jul-19 02:47 PM Makes it more manageable, and that's plenty enough for proof of concept experiments 01-Jul-19 02:47 PM 100kV at even 10A still 1MW peak beam power, plenty you can do there and very easy to achieve 01-Jul-19 02:49 PM it's annoying that there doesn't seem to be a quick and easy HVL/TVL calculator online anymore for this kinda thing 01-Jul-19 02:49 PM the math isn't too complicated at low energies like this but maybe it's a liability thing 01-Jul-19 02:50 PM if you're only talking Photoeffect it's really easy to do 01-Jul-19 02:50 PM above ~500 keV compton comes into play, and at a couple MeV pair production will be an issue 01-Jul-19 02:52 PM yep 01-Jul-19 02:52 PM i've been digging through research papers for similar-sized dense plasma focus devices to try and figure out what my x-ray shielding needs will be for my device, and it seems that it'll primarily peak at whatever the characteristic x-rays of the anode material are (so, with copper, like 8 keV; higher for heavier anodes) but with a broad spectrum extending up to 100s of keV from acceleration bremsstrahlung 01-Jul-19 02:52 PM which is pretty interesting from a spectroscopy perspective.. kinda want to try a bunch of different anodes and see if i can spectrographically measure the peaks 01-Jul-19 02:56 PM Sounds like plenty of xray fun lol 01-Jul-19 02:59 PM @AdamMcCombs made a suggestion the other day involving lots of concrete and an engine hoist and i've been having really serious considerations about a ridiculously brute force solution to this problem since >_> 01-Jul-19 03:03 PM Distance can help 01-Jul-19 03:03 PM Just stand really far away lol 01-Jul-19 03:03 PM r² jazz hands 01-Jul-19 03:03 PM If you want to go the engine hoist route a multipart shield is probably your best bet because you are going to run into capacity limits fast. For me I was evaluating in because I have access to all the tools, but to get started you can just use wooden forms, cut rebar with an angle grinder if you don't have a proper cutter, and the tie tools for rebar are only a few bucks. You might have to rent a bender from home Depot but it should be relatively inexpensive. The material itself is probably the cheapest part 01-Jul-19 07:16 PM Hopefully that was not a bad buy 01-Jul-19 07:16 PM But how wrong can you really go when you get two Leybold D2.5E for $70 01-Jul-19 07:28 PM Nice! Were they in good shape? 01-Jul-19 07:29 PM The one that there is a photo of looks alright https://www.ebay.com/itm/123804327843 01-Jul-19 07:29 PM My girlfriend is picking them up on her way out here Wednesday so I suppose I will find out then. 01-Jul-19 07:29 PM Hmm...preview is not the item I got but the link is correct 01-Jul-19 07:30 PM Hopefully they are usable 01-Jul-19 07:31 PM I figure I can probably get at least one usable pump out of the two 01-Jul-19 09:16 PM so I found a pretty cheap baffle / cold trap for a diffusion pump and it's local so I can pick it up, but it only seems to have 1 inlet presumably for LN2 01-Jul-19 09:16 PM I'm thinking I could make some kind of coaxial adapter 01-Jul-19 09:16 PM like take small diameter copper tubing and stick it down the 1 inlet, then have the water come back up around the tubing 01-Jul-19 09:16 PM the inside is also not very high surface area, it's more like a spheroid suspended in the high vacuum area 01-Jul-19 09:16 PM so maybe I could attach some fins to it 01-Jul-19 09:16 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/s-l1600-9614C.png 01-Jul-19 09:16 PM looks like that 01-Jul-19 09:40 PM I think the key thing is...how cheap is cheap and how much work do you need to do to get it working in the way that you want it to? That is an interesting design. 01-Jul-19 09:47 PM huh, i don't usually see conflat on cold traps meant to be coupled to a diffusion pump, interesting 01-Jul-19 10:19 PM it's $175, free shipping 01-Jul-19 10:19 PM (well, no shipping, since it's a local pickup) 01-Jul-19 10:19 PM and it's roughly the size (a bit bigger) than the flange on my diff pump, which should make connecting them fairly straightforward 01-Jul-19 10:19 PM all the other ones I've found are too small, way too expensive, or come with a diffusion pump 01-Jul-19 10:39 PM How big is your diff pump inlet? 01-Jul-19 10:54 PM ID is 5.25 inches, bolt circle is 7.5 inches, OD is 9 inches 01-Jul-19 11:21 PM That is pretty large. Not sure what sort of ability you have to make things yourself but I have been trying to work up a good design for a chevron baffle for my own diff pump based on an older one I was given but am not sure I can clean up enough (lot of rust between the baffles). If you have access to machining facilities the parts are fairly simple. An outer collar with a coil of copper tubing soldered to it and an insert with the baffles located in slots that press fits inside the collar. I probably should just take a photo of the pieces. 01-Jul-19 11:36 PM https://i.gyazo.com/7d1180a20aa1e936f6c3d011898a36a8.jpg <-- outer collar, inner collar, and the baffle insert. You can see the line where the outer collar was welded up and the transition between the inner press fit piece with the slots for baffles and the part that press fits into the outer collar. 01-Jul-19 11:36 PM If you have to modify that spheroid trap (beyond sorting a way to recirculate water) I think it will be a whole lot of frustration for you. 03-Jul-19 08:51 AM If I got one of these things: https://www.ldsvacuumshopper.com/nwto1bab.html 03-Jul-19 08:51 AM Should I be removing the o-ring and greasing under it? 03-Jul-19 08:51 AM I guess it would not hurt 03-Jul-19 08:51 AM but usually things like this are not greased 03-Jul-19 08:56 AM Yeah, grease is not really needed for something like this. Only time I ever used any coating on an oring in my system is to very lightly coat the diff pump inlet oring with diff pump oil, wiping off the excess. Your big bell jar seal would probably want some, but usually standard oring seals don't require it. 03-Jul-19 09:35 AM Wait we shouldn't have greased the NW25 orings? 03-Jul-19 09:35 AM Oh no 03-Jul-19 09:37 AM Not that you shouldn't, but it is not needed at all. By itself dry KF is good to 10^-7 torr. Using grease would actually lower it's performance at the higher level due to poor outgassing of grease 03-Jul-19 09:37 AM Well, I guess in that sense you really shouldn't lol 03-Jul-19 09:38 AM We've got 12 orings feeding into the baseplate, and they're all greased, and from 30mTorr we're leaking at ~1.6mTorr per second 03-Jul-19 09:38 AM And that's with the plumbing blanked off 03-Jul-19 09:38 AM so no bell jar, no feedthrough 03-Jul-19 09:38 AM So if we're nowhere near outgassing of grease vacuum, grease don't hurt? 03-Jul-19 09:38 AM At your vacuum levels it won't cause an issue besides extra mess, but if you are using KF to push to high vacuum, best to leave them as is 03-Jul-19 09:43 AM We just have a roughing pump hooked up, and the goal is 10e-2 03-Jul-19 09:43 AM So grease probably isn't the issue eh? Probably hair or sawdust? 03-Jul-19 09:45 AM At that level, no. Hair and sawdust is always a bad idea regardless of the level 03-Jul-19 09:45 AM With one bizarre exception 03-Jul-19 09:48 AM I probably shouldn't be sharing a room with a bandsaw 03-Jul-19 09:49 AM Probably less than ideal lol 03-Jul-19 09:50 AM Oh well, we just got a box of kimtech wipes, so I can use those instead of paper towels for cleaning seals 03-Jul-19 09:50 AM And a plate of ATP-5 is on the way for a new baseplate that won't deform like our acrylic one is 03-Jul-19 09:53 AM At what level of vacuum does acrylic stop being acceptable? 03-Jul-19 10:03 AM Depends on the preparation, as well as the size and pumping speed lol. I actually will have some very interesting info regarding acrylic for pulsed accelerators that will allow anyone to convert standard conflats into these devices, since that is technically the default method anyway. 03-Jul-19 10:03 AM Generally speaking though, 10^-6 torr at most 03-Jul-19 10:03 AM But often high pumping speeds are used at this level 03-Jul-19 10:05 AM Hmm 10^-6 is probably plenty for most of what I want to do. 03-Jul-19 10:05 AM I have a ton of acrylic that I rescued from a friend's driveway. He does set building for the film/tv industry and brings home the extras 03-Jul-19 10:06 AM What's the part and application? I wouldn't recommend acrylic generally under normal circumstances 03-Jul-19 10:07 AM I was thinking about using it for a viewport but glass is probably better. I already have the acrylic though. 03-Jul-19 10:18 AM How big of a viewport? 03-Jul-19 10:27 AM If I use the body of the cold trap on the leak detector Ive got as the chamber there are two options. The larger opening is ~4.5" and the smaller option is 1.5". 03-Jul-19 10:27 AM Ive got acrylic in anywhere from just a bit under 0.25" up to 1" 03-Jul-19 10:31 AM How thick is the acrylic? 03-Jul-19 10:31 AM Oh nvm just saw your response 03-Jul-19 11:07 AM If you err on the side of caution and use a thick piece it probably would work though I wouldn't say I recommend it unless you understand the risks involved lol 03-Jul-19 11:15 AM Our 1" cast acrylic is now a paraboloid 03-Jul-19 11:15 AM So we're going with an aluminum plate 03-Jul-19 11:15 AM You can see a distinct curvature along its edges 04-Jul-19 02:12 AM https://www.youtube.com/watch?v=mvZ1dJuvenw 04-Jul-19 02:45 AM Some exported images, of a hair and a Xeon CPU http://diyhpl.us/~nmz787/pdf/smi3200/pics.html#micrographs 04-Jul-19 02:45 AM I really need to get my SEM working... Ablating stuff is fun, but sometimes definitely not what you want when you're trying to get good high res images 04-Jul-19 02:55 AM Il trade you 04-Jul-19 11:19 AM So, this was not really my original plan, but it could actually freakin work. I have enough parts to actually configure my accelerator to be attached directly to the propulsion chamber, with a small gate valve to isolate the chambers in between, and another large valve that goes to an old 6" ion pump. I could prepump the accelerator through the propulsion chamber, isolate it, and run it from the ion pump. That means I could have both systems simultaneously operational... 04-Jul-19 11:19 AM This would leave the inputs and diagnostics open for both chambers, so I don't lose any functionality for either 04-Jul-19 11:19 AM In theory I could even attach my third 2.75" conflat chamber to the rig and have that simultaneously set up for miniaturized pulsed beam stuff as well. 04-Jul-19 03:08 PM Playing with my new atmospheric plasma wand. It really makes the air stinky, I assume from ozone generation... 04-Jul-19 03:27 PM Lol 04-Jul-19 03:27 PM I kinda like the smell of ozone 04-Jul-19 03:27 PM In a very brief amount 04-Jul-19 07:44 PM Well, I have tentatively finished the CAD for the primary EXEDA configuration for its highest power mode. Unfortunately each mode and experiment will require a different internal configuration and machined parts, but it will be designed to be modular and easily changed based on desired output. This mode should be able to deliver several kA beams, anywhere from 1-5kA. I need to still do electrostatic simulation to make sure field strengths are where I want them, but now the design is finally coming together. Looking at it actually together for the first time, it's exciting and quite scary. Finally feels like I'm actually starting to do some legit particle accelerator engineering for the first time lol. 04-Jul-19 07:44 PM If the field strengths for this model checks out, then I should be a go to actually share renders and details of this beast for the first time, actually finishing up the first cut away renders now. 05-Jul-19 02:41 AM If anyone's interested the work I did at CERN just got released :D Got ma name in the acknowledgements http://accelconf.web.cern.ch/AccelConf/ipac2019/papers/thprb067.pdf 05-Jul-19 02:41 AM I'm very happy 05-Jul-19 06:27 AM Nice! 05-Jul-19 06:42 AM Congrats! 05-Jul-19 07:32 AM That's awesome! 05-Jul-19 11:02 AM If I'm using a pump that's rated for ultimate pressure of 20 mTorr, 11.7 m^3/hr, and it's attached via an 18" long, 1" ID hose plus some plumbing, to a 30 gallon vessel. Is it reasonable for it to take two hours to hit 50mTorr? 05-Jul-19 11:02 AM I don't know what's reasonable speed and what's not. It hits ultimate pressure in a minute or two when the volume is only about a liter or so 05-Jul-19 12:04 PM What type of pump? Single stage or two stage rotary vane? Also what are the physical dimensions of the 30 gallon vessel? Speed is 3.25 L/s (just for reference for myself) 05-Jul-19 02:48 PM Edwards RV8 05-Jul-19 02:48 PM It's an 18" ID and 24" tall bell jar 05-Jul-19 02:48 PM Two Stage Rotary Vane 05-Jul-19 02:53 PM Yeah that is way too long lol 05-Jul-19 03:13 PM How is 18" ID * 24" tall 30 gallons??? My calculations show 22.23 liters 05-Jul-19 03:13 PM Oh, whoops 05-Jul-19 03:13 PM I used 18 as circumference 05-Jul-19 03:13 PM Still i get 26.44 gallons 05-Jul-19 03:13 PM Or 100.1 liters 05-Jul-19 03:13 PM http://m.wolframalpha.com/input/?i=%28%28%2818%22+%2F2%29%5E2+*+pi%29*+24%22%29+to+gallons 05-Jul-19 03:13 PM Honestly that seems reasonable if it takes a minute for a liter, but 120 for 100 liters 05-Jul-19 03:19 PM [whups, scrolled up] 05-Jul-19 03:19 PM (i am a newb tho) 05-Jul-19 03:19 PM actually nvm my question still stands, valve it off if you can and see what it leaks up to 05-Jul-19 03:19 PM or how quickly.. the curve of change is usually pretty telling 05-Jul-19 03:21 PM Leak rate once closed off from pump is about 1mTorr every two or three seconds 05-Jul-19 03:21 PM big 05-Jul-19 03:21 PM It's 3 l/s, at 100 L it shouldn't take 2 hours still 05-Jul-19 03:21 PM We've isolated that leak to the L gasket and bell jar seam 05-Jul-19 03:21 PM So 05-Jul-19 03:21 PM We'll see how it do when we switch to ATP-5 aluminum base instead of acrylic 05-Jul-19 03:21 PM @applied_ion Isn't that assuming full pressure though? 05-Jul-19 03:22 PM Well I guess it could also be the baseplate adapter 05-Jul-19 03:22 PM Once you start pumping, don't you get more time required from diffusion 05-Jul-19 03:22 PM ? 05-Jul-19 03:22 PM Yeah it gets real slow towards the eng 05-Jul-19 03:22 PM it hit 100mTorr in the first hour 05-Jul-19 03:22 PM The last 50% took ages 05-Jul-19 03:22 PM like several minutes per mTorr 05-Jul-19 03:22 PM I should have charted it , but bossman said "stop charting your pumping times" 05-Jul-19 03:22 PM I'm a simple man, I see science, I write it down 05-Jul-19 03:23 PM Seems like you baseplate shouldn't matter about the material for these pressures 05-Jul-19 03:24 PM The baseplate... it tends to curve after a while under pressure 05-Jul-19 03:24 PM Can't you try recreating the gasket after some cleanup? 05-Jul-19 03:24 PM At those levels, it's so high pressure diffusion is not a factor 05-Jul-19 03:24 PM Oh, add reinforcement?? 05-Jul-19 03:24 PM @Applied_Ion ahh 05-Jul-19 03:24 PM Ok 05-Jul-19 03:24 PM We clamped a bunch of angle aluminum on. Now the acrylic and aluminum both bow 05-Jul-19 03:24 PM Inside the jar? 05-Jul-19 03:24 PM I'd epoxy it on inside or on bottom 05-Jul-19 03:25 PM We got much better pump down times replacing the six foot 1/2" ID hose with an 18" long, 1" ID hose 05-Jul-19 03:25 PM (of acrylic sheet) 05-Jul-19 03:25 PM Like I said, we've got aluminum baseplate in the mail 05-Jul-19 03:25 PM Ah, so it's not ages away 05-Jul-19 03:26 PM Aye, should be less than two weeks. 05-Jul-19 03:26 PM Plus, LDS being on vacation, there's a sale on anything ordered this week 05-Jul-19 05:57 PM hey, whats a good starter low-power vacuum pump? 05-Jul-19 05:57 PM not looking for UHV, just looking for something decent that wont break and has semi-standard fittings 05-Jul-19 05:57 PM for example, does this look any good? Im ok buying used, for the most part https://www.ebay.com/itm/2450AE-44-Thomas-Oil-Free-Compressor-Vacuum-Pump-115V-3-CFM-PARALLEL-PRESSURE/153535564834?epid=13027364072&hash=item23bf6ecc22%3Ag%3ASIcAAOSwLuJa0UYN&LH_ItemCondition=4 05-Jul-19 05:57 PM if so, what would be needed in addition to this get a working setup? 05-Jul-19 05:57 PM (sorry, am noob) 06-Jul-19 09:23 AM What are you planning on using it for? 06-Jul-19 09:23 AM All depends on your use case. Pumps like this aren't for chamber based vacuum stuff, rather for applications where fluid or gas needs to be drawn into something, like gas analyzers, particulate counters, etc (if something like that is your goal) 08-Jul-19 10:28 AM a random find: https://petapixel.com/2019/07/05/goodbye-aberration-physicist-solves-2000-year-old-optical-problem/ , I wonder if this is applicable to electron microscopy 08-Jul-19 10:28 AM given the picture at the top of the page id guess not though xD 09-Jul-19 09:54 AM It's just an analytic solution to something we solved numerically before 09-Jul-19 09:54 AM Not very useful afaict 09-Jul-19 12:46 PM It seems less approximate that previous solutions 09-Jul-19 01:35 PM Anyone know of a mini/micro robot arm that would work in vacuum as a micromanipulator? Something like a 5dof or 6dof robot? 09-Jul-19 01:35 PM Everything I see on google is about 10x too big 09-Jul-19 02:03 PM Sounds like a custom build lol 09-Jul-19 02:03 PM That's how I had to approach my pendulum stand for propulsion, everything is normally way too big, had to improvise 09-Jul-19 02:05 PM or you just build a bigger chamber :D 09-Jul-19 02:27 PM the big problem would be building it with materials that wouldn't outgas heh... 09-Jul-19 02:27 PM easy enough to replace all the lubricants with diff pump oil or something, but yeaaa 09-Jul-19 02:27 PM can't use belts or most plastics 09-Jul-19 02:33 PM Depends on your vacuum level 09-Jul-19 02:38 PM true 09-Jul-19 02:53 PM @nmz787 how high vacuum, what size chamber, and what application? 09-Jul-19 02:55 PM Inside my FIB, for doing things like sectioning dies and transferring to a TEM window... 10^-5 torr. chamber is maybe 8-12" tall and at least the same wide and long... But working around the pole piece means the clearance on the arm ends needs to be pretty small 09-Jul-19 02:56 PM 10^-5 torr you can get away with a lot of materials at least 09-Jul-19 02:57 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190625_155046_exported_7509058907486-D9C5B.jpg 09-Jul-19 02:57 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190625_155149_exported_2243051988440-C0EA2.jpg 09-Jul-19 02:57 PM Looks like a pretty awesome setup 09-Jul-19 02:57 PM Also seems like there is plenty of room 09-Jul-19 02:58 PM It is pretty nice so far :) 09-Jul-19 02:58 PM You buy it as a full system? 09-Jul-19 03:00 PM Yeah 09-Jul-19 03:00 PM It was a pretty amazing buy 09-Jul-19 03:00 PM If I can only fill the rest of my lab with such deals 09-Jul-19 03:00 PM https://youtu.be/FctGTnlRK0U 09-Jul-19 03:09 PM Nice lol, so I guess you are going for similar except more like a robotic arm manipulator? 09-Jul-19 03:26 PM Yeah, just thinking on how to add something like an arm inside... Lots of FIBs have something like an arm inside, so maybe I can just find one of those used 09-Jul-19 03:26 PM Basically to cut a section of silicon with the beam, then bring in the arm with a rod on the end, and then weld on the piece of silicon to the arm tip 09-Jul-19 03:26 PM So you can transfer the cut piece 09-Jul-19 04:09 PM If you get to that functionality you will need to take some videos of the system in action! 09-Jul-19 04:09 PM I've seen videos of FIB processes before, really cool stuff. Almost convinced me to try myself, but just too many projects lol 09-Jul-19 04:58 PM It's working, I just made a clone of the system harddrive to add some reverse-engineering tools for the vendor software.. I'll add a screen recording tool too 09-Jul-19 04:58 PM But maybe you meant a video of the robot arm... @AdamMcCombs recommended an IR camera for in the chamber, so that's on my list of plans too 09-Jul-19 05:01 PM Oh yeah lol of the arm if you get it running and moving samples around 10-Jul-19 08:31 AM Well, I'm officially revealing one of the major, critical components I will be using for EXEDA this friday. I garauntee this component teardown will be quite a unique and new one at the home-maker level 10-Jul-19 01:50 PM ohhh what where link? 10-Jul-19 01:55 PM Not yet lol, Friday will be first reveal, then teardown after. This is the non reproducible piece that I will be designing a conventional replacement version for use with standard conflat chambers. 10-Jul-19 03:24 PM ohh, I think you teased that before 10-Jul-19 03:24 PM that it's some special semiconductor, was it the DSRD? 10-Jul-19 03:32 PM Oh no lol, no DSRD. It's a big piece, passive component 10-Jul-19 03:34 PM hmmm 11-Jul-19 08:54 AM moin! 12-Jul-19 12:16 AM moin 12-Jul-19 12:53 PM Has anyone ever plasma cleaned optical elements? Trying to figure out if that's something people do.... 14-Jul-19 09:21 PM Anyone happen to know if the VAT pneumatic valves can be converted to manual operation? Something like this: https://www.ebay.com/itm/273792551898 14-Jul-19 09:21 PM Tons of the pneumatic ones on eBay but I really don't want to deal with a compressed air source for them. 14-Jul-19 09:21 PM Already have a compressor but do not really want to need to use it for valves....extra complications that aren't really needed. 14-Jul-19 09:33 PM uhm.... I'd just recommend using pneumatics, if you don't have leaks you should litterally just be-able to run the system off a nitrogen cylinder if you really don't want a compressor running once in a blue moon. But either way you could probably tear them apart, remove whatever big spring in there keeping it NO/NC and just manually actuate it... But it'll only stay held in a position of vacuum sucking it shut unless you machine a mech to actuate them... Which would be more time and effort probably than just setting up pneumatics. 14-Jul-19 09:33 PM I have personally never torn into the VAT values, so I can't tell you what they are like inside, much newer so I would suppose probably less likely canidates to convert to manual 14-Jul-19 09:42 PM Yeah I was considering that too, keeping my costs low is the goal at the moment 15-Jul-19 06:12 AM I think @qualia has experience with the vat valves 15-Jul-19 02:51 PM w00t, pretty sure I just passed the 2nd certification exam 15-Jul-19 02:51 PM building a hairspring from scratch, and timing it out in a serviced watch (that had issues) 15-Jul-19 04:08 PM congrats! 15-Jul-19 04:38 PM i do not have experience with those particular VAT valves, fwiw 15-Jul-19 04:38 PM but i have done a little bit of pneumatics noodling before 15-Jul-19 04:48 PM looks like that one is normally closed, you put 4-8 bar of pressure on it and it pops open http://www.vatvalve.com/en/business/valves/product?id=26524-KA21 15-Jul-19 04:48 PM do be mindful of the pressures that various pneumatic bits and bobs will need; my gate valve only wants something like 20psi while my pitched-vane throttle valve needs rather higher pressure to actuate 15-Jul-19 04:48 PM i am not yet sure how to best deal with mix-and-match pneumatics without an 'everything gets a regulator' kind of approach 15-Jul-19 05:29 PM the "everything gets a regulator" approach is the one used in most applications i have seen this far 15-Jul-19 05:29 PM except for matched components maybe (everything the same pressure) 16-Jul-19 09:56 AM moin! 16-Jul-19 11:15 AM moin c: 16-Jul-19 01:51 PM moin @qualia ! 16-Jul-19 01:51 PM and moin @piGuy 16-Jul-19 01:51 PM and moin @GigaSquirrel ^ 16-Jul-19 01:51 PM and moin rest of you. 16-Jul-19 01:51 PM :-D 16-Jul-19 01:51 PM Moin @Pan Da ! 16-Jul-19 02:02 PM moins all around 16-Jul-19 11:59 PM moin 17-Jul-19 06:58 AM moin 17-Jul-19 07:17 AM Moin! 17-Jul-19 10:19 AM moin! 17-Jul-19 02:45 PM https://i.gyazo.com/d08425a55ff4d43a4feb80ff899c3d35.png If I want to hook up the exhaust of this diff pump to a KF16 connection on my roughing pump what sort of tubing should I be aiming for? 17-Jul-19 02:45 PM Thinking about making a simple KF16 to hose adapter on my lathe but not sure what tubing options are really acceptable. Had some of the thick red natural rubber tubing originally as far as I know 17-Jul-19 02:50 PM watch out, there will always be some diffoil in the foreline 17-Jul-19 02:50 PM I'd go for metal 17-Jul-19 02:54 PM How would you go about hooking up the metal to the diff pump exhaust? All the ways I am coming up with still involve a section of non-metal tubing unless I have someone try welding/silver soldering a flange to the tube 17-Jul-19 02:54 PM The welding/soldering route seems adding extra sources of complexity 17-Jul-19 02:54 PM yeah, brazing 17-Jul-19 02:54 PM but maybe someone else here has a better idea, I've never worked with a pump like that 17-Jul-19 02:54 PM all of mine already have KF 17-Jul-19 02:56 PM Yeah this one is pretty old but the spec sheet claims it operates up to a backing pressure of 500microns which is rather impressive 17-Jul-19 02:56 PM not bad 17-Jul-19 02:56 PM what's your use case where you have that high pressure? 17-Jul-19 02:56 PM plus what oil are you using? 17-Jul-19 02:57 PM I am not planning to have that high of pressure, just what the spec sheet claims 17-Jul-19 02:57 PM and I have some DC704 (equivalent anyway i think) 17-Jul-19 02:59 PM sweet, I got down to e-8 with my 704 17-Jul-19 03:00 PM Thats impressive! 17-Jul-19 03:00 PM Here is what the spec sheet for that diff pump says, if you were curious: "Veeco EP3AB 170 L/s air cooled 4 stage fully fractionating stainless steel body and thermo insulation collar. Fractionation assures that only the lowest vapor pressure fractions of the pumping fluid are fed to the top jet to give the highest possible vacuum. Foreline tolerance exceeds 500 microns. Optically dense foreline baffle minimizes loss of diffusion pump oil." 17-Jul-19 03:01 PM ohh the foreline baffle is a very nice feature 17-Jul-19 03:02 PM I am trying to decide if I want to deal with sticking a chevron baffle in between that necked down adapter for the diff pump or just go without one to start...probably should just finish cleaning up this old one I was given or making a new insert for the cooling jacket 17-Jul-19 03:02 PM Also need to decide how I want to hook up this turbo I have once I make sure everything works haha. Somehow I ended up building two vacuum systems when intending to end up with one 17-Jul-19 03:07 PM if slight contamination is no issue you don't need the baffle 18-Jul-19 03:33 AM https://petapixel.com/2013/07/29/hack-transforms-common-microscopes-into-gigapixel-superscopes/ 18-Jul-19 09:32 AM Wow 18-Jul-19 09:32 AM That's cool 18-Jul-19 09:34 AM Why is this the first I am hearing about this...that is really neat 18-Jul-19 09:34 AM http://www.biophot.caltech.edu/research/fpm.html 18-Jul-19 09:34 AM seems like the actual research...links were broken on the petapixel story 19-Jul-19 08:07 AM I know it’s several posts ago but en regard to the fore line material to the little diffusion pump we would use a short length of gum tubing to an L shaped copper pipe. Sometimes a elbow sweated to a length of pipe. That was mounted sloped back towards the diff pump as to allow the diff oil that made it too far up the outlet and into the fire line to eventually work its was back to the diff pump. A short length of gum rubber in the total fire line system, say less than a foot, will not hurt you so much. When you are working with many feet of it you are asking for trouble though. 19-Jul-19 08:07 AM Fore. Not fire. Why can’t there be auto correct on IPhone for people like me who use words the average 14 year old does not? Don’t do what you think you want me to do, or say phone! Sorry about the autocorrect rant. 19-Jul-19 08:22 AM For my foreline I am also using gum rubber vacuum hose to adapt from the Edwards flange to a standard KF adapter on my roughing pump assembly. The diff pump I have has an integrated foreline baffle which the cooling lines wrap around, which prevents backstreaming from the diff pump. Small pumps probably do not have this feature. 19-Jul-19 09:34 AM https://www.youtube.com/watch?v=Cyu7etM-0Ko 19-Jul-19 09:34 AM Shows just how cheap you can make a sputtering setup for experimentation at home. 19-Jul-19 09:34 AM Obviously the better materials/etc you can use the better off you'll probably be for tuning it and long term use. But yea cool to see you can get something working on a really tight budget like that. 19-Jul-19 09:39 AM Oh yeah lol sputtering can be set up dirt cheap. Mason jar sputterers are not something really for diy semiconductor level stuff, but for simple coatings and mirrors it's a great demo unit. 19-Jul-19 12:00 PM Yea I need to actually setup a system considering I have like an actual proper sputter head kicking around. 19-Jul-19 12:00 PM Though I think evap is going to be easier/better for what I want to do. 19-Jul-19 01:27 PM Hurts my soul how viton conflat seals are like 5 times more expensive than proper copper gaskets. 19-Jul-19 01:27 PM Which I will need for certain chambers I have for either easy access into the chamber or for sealing to conflat with damaged knife edges 19-Jul-19 01:27 PM I understand its more expensive due to the weird topology of the viton, its not a simple O-ring of-course 19-Jul-19 01:27 PM but yea still staggering what they cost 19-Jul-19 01:31 PM Yeah lol, though the are generally reusable indefinitely. 19-Jul-19 01:36 PM Yea that is true, so long as your not baking out up to near their max temp anyway I'm sure. 19-Jul-19 02:00 PM This is why jointless glass systems remained in use so long. No seals or gaskets to buy. Just gas and glass tubing. It’s a shame many labs have or are loosing their glassworking abilities. 19-Jul-19 09:16 PM I discovered the hard way that laminar flow benches are not designed to fit through standard residential doorways.... 19-Jul-19 09:53 PM RIP 19-Jul-19 11:27 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/chrome_wGdk5mrqwr-97989.png 19-Jul-19 11:27 PM "emollient in cosmetics"... 19-Jul-19 11:27 PM too bad makeup (unless it's lotion or something) is probably more expensive in quantity than diffusion pump oil 19-Jul-19 11:29 PM lol isn't some diff and most of rouging pump oils just highly highly refined mineral oil? 19-Jul-19 11:29 PM no it's a special silicone oil I'm pretty sure 19-Jul-19 11:29 PM ah right for diff pump it may be different 19-Jul-19 11:29 PM I know roughing pump is just mineral oil basically 19-Jul-19 11:29 PM for normal applications 19-Jul-19 11:29 PM corrosive is different 20-Jul-19 01:15 AM Yeah good did pump oil is pretty specialized. You can use to oil in a pinch if you have low gas load and don't care about contamination/fire risk. 20-Jul-19 01:16 AM Morning sunshine :P 20-Jul-19 01:17 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190720_004448-ECE63.jpg 20-Jul-19 01:17 AM wth is that? 20-Jul-19 01:18 AM I'm literally up the morning of the 50th anniversary of the appolo 11 landing painting a Russian lander because a friend needs it later today 20-Jul-19 01:18 AM Kinda ironic 20-Jul-19 01:19 AM lmao 20-Jul-19 01:19 AM Is it what I should be working on today? 20-Jul-19 01:19 AM No 20-Jul-19 01:19 AM But here I am waiting for the 3rd coat to dry because damn they liked shinny things back then 20-Jul-19 01:20 AM hehe 20-Jul-19 01:21 AM It's Luna 9 20-Jul-19 01:21 AM Why didn't you just sputter coat it? :P 20-Jul-19 01:21 AM First sucsesful soft landing on the moon 20-Jul-19 01:21 AM I mean 20-Jul-19 01:21 AM This thing is 3d printed on a very nice stratasys 3d printer 20-Jul-19 01:21 AM But there's no way it would ever pump down 20-Jul-19 01:21 AM Would be the virtual leak from hell 20-Jul-19 12:16 PM What are these fittings called? With the nut you tighten to grab them 20-Jul-19 12:16 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-3BB00.png 20-Jul-19 12:16 PM I think we want to convert those to NW25 20-Jul-19 12:16 PM Because our OD pump has NW25 on the outlet, but all our valves are this nut grip style 20-Jul-19 02:04 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190720_140254-F1361.jpg 20-Jul-19 02:04 PM Just got an MKS 971B ionization gauge 20-Jul-19 02:04 PM Should I be worried about the rust / schmutz in there? 20-Jul-19 02:06 PM it's gonna need recalibration anyways so cleaning it before would not hurt 20-Jul-19 02:07 PM how can I calibrate it? and why do you say it will need recalibration? 20-Jul-19 02:07 PM That looks pretty rough. It may be a sign of heavy wear. Over time the filament will sputter, but being on the outside it was probably exposed to some heavy contamination process 20-Jul-19 02:08 PM just looking at it I thing it's a cold cathode / penning 20-Jul-19 02:08 PM yeah cold cathode ionization gauge 20-Jul-19 02:08 PM inverted magnetron I think 20-Jul-19 02:08 PM https://www.mksinst.com/f/971b-unimag-cold-cathode-transducer 20-Jul-19 02:09 PM Yeah its cold cathode 20-Jul-19 02:09 PM That external contamination could be more troubling in that case 20-Jul-19 02:09 PM You would definitely need to recalibrate 20-Jul-19 02:11 PM I guess my question re calibration is, if I can't buy an ionization gauge without needing to recalibrate, how can I ever find a suitable reference to calibrate it against 20-Jul-19 02:11 PM unless I could calibrate it against my pirani gauge at roughing pump pressures 20-Jul-19 02:12 PM you could try a hornet 20-Jul-19 02:12 PM https://gigabecquerel.wordpress.com/2019/05/22/reverse-engineering-the-instrutech-igm-400-hornet-gauge/ 20-Jul-19 02:13 PM what leads you to believe that those would be better calibrated than this though? 20-Jul-19 02:13 PM hot cathodes are way harder to get out of spec 20-Jul-19 02:14 PM ah, okay, that's good to know 20-Jul-19 02:17 PM cold cathodes can only apply a voltage and read the resulting current, but hot cathodes can regulate a known electron current and measure the resulting ion current 20-Jul-19 08:34 PM okay... how do you all move big heavy equipment? pallet jack? engine hoist? 20-Jul-19 08:34 PM What specifically are you looking to move? 20-Jul-19 08:43 PM (just read a lot of people saying dont do engine hoist) 20-Jul-19 08:43 PM a universal tool and cutter grinder (looks more like a surface grinder, and can be used as such) 20-Jul-19 08:43 PM a bit over 1100kg, or about 2500lbs 20-Jul-19 08:43 PM That's a lot for most engine hoists 20-Jul-19 08:44 PM I have no idea how close they will deliver/drop the thing off.. maybe in the street, maybe sidewalk, maybe the sloped driveway 20-Jul-19 08:44 PM if from the sloped drive way, it is a straight shot over one bump tot he front door.. then inside the front and against a wall 20-Jul-19 08:44 PM the issue is getting it to the inside of the house 20-Jul-19 08:44 PM wish I had space in the garage, honestly 20-Jul-19 08:44 PM Even if it's rated for it moving it down a complex grade is a lot of dynamic load 20-Jul-19 08:45 PM there's a lot of hindsight going on right now (also, it is due to arrive thursday, so enough time to find a rigging company to bring it in if need be, I dont want to die..) 20-Jul-19 08:46 PM Picture of it? 20-Jul-19 08:46 PM lots of people recomending using pipes to roll a bridgeport into position.. this will be on a pallet 20-Jul-19 08:46 PM yeah, one sec 20-Jul-19 08:46 PM backside 20-Jul-19 08:46 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/s-l1600-ABE73.jpg 20-Jul-19 08:46 PM I think that is a 4x4ft pallet 20-Jul-19 08:46 PM the front is less interesting, that shot shows some good spots to grab 20-Jul-19 08:48 PM Looks 40x48 20-Jul-19 08:48 PM if you say so.. 20-Jul-19 08:48 PM they may have repaletized with all of the accesories and such, too 20-Jul-19 08:48 PM or at least wrapped those up in a box with it 20-Jul-19 08:48 PM Any clearance issues? 20-Jul-19 08:48 PM I have french doors in the front, 6ft.. should clear it 20-Jul-19 08:49 PM No steps through front door? 20-Jul-19 08:49 PM there is a bump, a few inches 20-Jul-19 08:49 PM but there are 4 or 5 steps from ground level to patio/front door 20-Jul-19 08:49 PM or a steep small driveway 20-Jul-19 08:50 PM So you can roll up the driveway instead of steps? 20-Jul-19 08:50 PM the delivery guy may be nice enough to put it on the drieway right by the door 20-Jul-19 08:50 PM the driveway isnt exactly smooth, neither 20-Jul-19 08:50 PM but, I mean, a rod will roll, sure 20-Jul-19 08:51 PM I think you want either pallet jack or roll a lifts 20-Jul-19 08:51 PM I can also take a shot of said driveway before nightfall 20-Jul-19 08:51 PM Also a chain fall 20-Jul-19 08:51 PM roll-a-lifts? 20-Jul-19 08:51 PM oh, thanks google 20-Jul-19 08:51 PM yeah, those look pretty good 20-Jul-19 08:53 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_1481-237A1.JPG 20-Jul-19 08:53 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/2018-09-22_14.18.46-FEDE2.jpg 20-Jul-19 08:53 PM They are incredibly useful. Looks like they would strap on ok to each side 20-Jul-19 08:54 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0468-1EA37.JPG 20-Jul-19 08:54 PM and yeah, my fence is half cut away already (had to replace the sheathing behind it) 20-Jul-19 08:54 PM and willing to take it all down (making a gabion fence anyways, this summer) 20-Jul-19 08:55 PM Can you go through the garage door? 20-Jul-19 08:56 PM no, car in the way 20-Jul-19 08:56 PM immobile project car 20-Jul-19 08:56 PM So you have to get it up to that platform? 20-Jul-19 08:56 PM yeah 20-Jul-19 08:56 PM hindsight.. 20-Jul-19 08:57 PM Well that is a fun one 20-Jul-19 08:57 PM You could build a ramp but the compound angle is going to be hard 20-Jul-19 08:58 PM a ramp up the stairs or from the driveway 20-Jul-19 08:58 PM I have plenty of 2x4 + OSB and plywood on hand 20-Jul-19 08:58 PM even some 2x6 20-Jul-19 08:58 PM oh, and time till thursday.. 20-Jul-19 08:58 PM but yeah, I could build a level/ramp to go on that hump, from the driveway 20-Jul-19 08:59 PM What about that pile of dirt? 20-Jul-19 08:59 PM and pray the delivery guy will atleast put it on there 20-Jul-19 08:59 PM ... you mean my rose? 20-Jul-19 08:59 PM What's it being delivered on? 20-Jul-19 08:59 PM pallet? 20-Jul-19 08:59 PM As in truck 20-Jul-19 09:00 PM yeah, residential delivery, liftgate 20-Jul-19 09:00 PM that's all I know 20-Jul-19 09:00 PM is it uyp to me to get it off of liftgate? 20-Jul-19 09:00 PM I should really check some of these nuances out 20-Jul-19 09:00 PM Unless you paid for indor delivery they usually drop it off street level 20-Jul-19 09:01 PM well, so long as they drop it off, and not just bring a liftgate down and shrug when I dont have tools to pull it away... 20-Jul-19 09:01 PM Do you know if it's a semi or a straight truck? 20-Jul-19 09:01 PM I also wonder if I throw $100 at the dude how close he could move it 20-Jul-19 09:01 PM I think Semi? 20-Jul-19 09:01 PM RoadRunner Freight 20-Jul-19 09:01 PM Damn 20-Jul-19 09:01 PM I was thinking back the lift gate up to the platform 20-Jul-19 09:02 PM the street is right in the front there.. no space 20-Jul-19 09:02 PM Yeah 20-Jul-19 09:02 PM smaaaal driveway 20-Jul-19 09:02 PM Forklift might be the way to go 20-Jul-19 09:02 PM So is the street right there or are you standing on a driveway in this photo? 20-Jul-19 09:03 PM I was on the sidewalk 20-Jul-19 09:03 PM so, another 5 ft till the street 20-Jul-19 09:04 PM Can you drive a vehicle over it or is there grass and stuff? 20-Jul-19 09:04 PM which means the distance I have to go from the street is not much 20-Jul-19 09:04 PM no grass 20-Jul-19 09:04 PM Dirt? 20-Jul-19 09:04 PM nope 20-Jul-19 09:04 PM Or just concrete? 20-Jul-19 09:05 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0469-78E82.JPG 20-Jul-19 09:05 PM sorry, window screen in.. 20-Jul-19 09:05 PM but you can see the rose 20-Jul-19 09:06 PM How bad would it be to block a lane for a few min? 20-Jul-19 09:06 PM kinda bad, busy-ish street 20-Jul-19 09:06 PM You could put dollies under the wheels of the project car to move it, if that makes it easier... 20-Jul-19 09:06 PM Iv done that several times in Seattle... 20-Jul-19 09:06 PM but when I had my packrat/POD dlivered they did it.. 20-Jul-19 09:06 PM most moving companies will do it on their own, like no need for a permit or whatever 20-Jul-19 09:07 PM Think your best bet is having it dropped in the driveway and building up cribbing to level with that concrete slab... 20-Jul-19 09:07 PM if it is mid day, it likely wont be too bad 20-Jul-19 09:07 PM So this might be an awful idea, but roll back tow truck with roll a lifts 20-Jul-19 09:07 PM Or rent a forklift 20-Jul-19 09:07 PM @LRM the 'cribbing' is a decent idea 20-Jul-19 09:07 PM I think 2500lbs is pushing most liftgates... 20-Jul-19 09:08 PM and pay the guy to move the item the 15 ft to the driveway 20-Jul-19 09:08 PM Nah 20-Jul-19 09:08 PM Not for the nice ones 20-Jul-19 09:08 PM This is why I don't buy big heavy equipment. 20-Jul-19 09:08 PM once I have a platform, I can just roll it 20-Jul-19 09:08 PM on rods 20-Jul-19 09:08 PM sometimes deals are too good to pass up 20-Jul-19 09:08 PM Usually the bigger the piece of gear, the better the deal. 20-Jul-19 09:09 PM Yeah, depending on how they are delivering it you might want to just slip the guy a couple bux to make things more convenient 20-Jul-19 09:09 PM Maybe you will get lucky and they will have a forklift too 20-Jul-19 09:09 PM Noxz, you're in seattle area? 20-Jul-19 09:09 PM they dealt with restaurante equipment, and came across it from a storage auction, so they didnt exacltty know what they had 20-Jul-19 09:09 PM @piGuy yes 20-Jul-19 09:09 PM just north of green lake a little 20-Jul-19 09:09 PM north west, I guess 20-Jul-19 09:10 PM If you need someone to stand around and provide questionable assistance/advice, let me know. 20-Jul-19 09:10 PM So standard freight truck has a lift gate and a pallet jack 20-Jul-19 09:10 PM I was actually there for a bbq earlier 20-Jul-19 09:10 PM @piGuy hah, sounds neat.. this would be thursday 20-Jul-19 09:10 PM So getting it most the was down the driveway should not be a problem 20-Jul-19 09:10 PM down? 20-Jul-19 09:10 PM you mean up.. right? 20-Jul-19 09:10 PM Up 20-Jul-19 09:11 PM we're on the same page 20-Jul-19 09:11 PM How rough/smooth is the driveway? 20-Jul-19 09:11 PM Your driveway is right on the edge of to steep to just push 2500 lbs up 20-Jul-19 09:11 PM The steep part 20-Jul-19 09:12 PM If you cant go straight you can always do switchbacks haha 20-Jul-19 09:12 PM Another good reason to slip the delivery guy a $10 20-Jul-19 09:12 PM $100 20-Jul-19 09:12 PM That's not a good idea with a pallet jack 20-Jul-19 09:12 PM it's a real bumpy driveway 20-Jul-19 09:13 PM Only go straight up inclines with a jack 20-Jul-19 09:13 PM home depot had a whole forklift when the gave me my stuffs 20-Jul-19 09:13 PM set it down right on the driveway 20-Jul-19 09:13 PM Bumps might be a problem for going up with a pallet jack 20-Jul-19 09:13 PM My driveway is a 15% grade. The thought of rolling any heavy equipment down or up it scares me. 20-Jul-19 09:13 PM Yeah road runner doesn't have that 20-Jul-19 09:13 PM yeah, this is a lil steep 20-Jul-19 09:13 PM hrm, k 20-Jul-19 09:14 PM 15 is nothing... 20-Jul-19 09:14 PM I actually got a digital inclinometer.. Ishoudl see what grade it is.. 20-Jul-19 09:14 PM (not doing anythign else right now but chatting) 20-Jul-19 09:14 PM Ok it's hard to see from photo 20-Jul-19 09:14 PM sun is going down.. so any mor ephotos? 20-Jul-19 09:14 PM Does that machine run on single phase power? 20-Jul-19 09:15 PM dont worry about that 20-Jul-19 09:15 PM VFD, plus the final destination ( after another year of school) and I have confirmed 3 ph 20-Jul-19 09:15 PM That's a no 20-Jul-19 09:15 PM One from further back? 20-Jul-19 09:15 PM I have other photos I can look through.. 20-Jul-19 09:15 PM but yeah, the sun kinda went down 20-Jul-19 09:15 PM Yeah... 20-Jul-19 09:15 PM Also if I'm available Thursday I may be able to come by with some of my rigging gear 20-Jul-19 09:16 PM OOoo 20-Jul-19 09:16 PM free pizza if you do.. 20-Jul-19 09:17 PM I should be around too. I have no rigging gear, but I do have puny muscles. 20-Jul-19 09:17 PM if you are using your muscles, you may die (dont stop it from falling) 20-Jul-19 09:18 PM That is true. 20-Jul-19 09:20 PM Last time I did a massive equipment move in greenwood this was my solution 20-Jul-19 09:20 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180418_082420-EC13B.jpg 20-Jul-19 09:20 PM 20 deg max incline (22%?) 20-Jul-19 09:20 PM oh wow 20-Jul-19 09:20 PM and yeah, greenwood is like 15blocks away 20-Jul-19 09:20 PM was that a rental or a service? 20-Jul-19 09:21 PM Service 20-Jul-19 09:21 PM and how heavy + dimensions? 20-Jul-19 09:21 PM It's rated for 24000lbs 20-Jul-19 09:21 PM And it was only like 600$ 20-Jul-19 09:21 PM Unfortunately Ballard Transfer is no longer around 20-Jul-19 09:21 PM If that was available for a rental, I could imagine some fun things to do with it. 20-Jul-19 09:22 PM also, remember, I gotta get it outta here in anothe ryear 20-Jul-19 09:22 PM I can also make a forklift just show up 20-Jul-19 09:22 PM hrrmm 20-Jul-19 09:22 PM do you own one or would it be a rental? 20-Jul-19 09:22 PM like, I have cash to throw at this to make sure nobody dies 20-Jul-19 09:22 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/2018-09-22_13.55.10-F05E2.jpg 20-Jul-19 09:22 PM Rental 20-Jul-19 09:23 PM @Noxz have you considered a storage unit for a year if you will be moving again soon? 20-Jul-19 09:23 PM They just bring it in on a truck 20-Jul-19 09:23 PM Or do you have plans for using this in the meantime 20-Jul-19 09:23 PM well, I wanna get it operational before then 20-Jul-19 09:23 PM and it is worth it to me to do that in the year 20-Jul-19 09:23 PM I can drive it as well 20-Jul-19 09:23 PM special licence needed? 20-Jul-19 09:23 PM Well that's a complicated question 20-Jul-19 09:23 PM 12hr saftey course with cones? 20-Jul-19 09:23 PM hehe 20-Jul-19 09:23 PM OSHA covers this 20-Jul-19 09:23 PM So all the regulations apply to employees 20-Jul-19 09:23 PM And fork lift certifications are given through employers 20-Jul-19 09:23 PM So me owning my own company... 20-Jul-19 09:24 PM hrmm 20-Jul-19 09:24 PM That doesn't apply 20-Jul-19 09:24 PM Well you're not an employee, so it's all good 20-Jul-19 09:25 PM So I have been trained and checked out 20-Jul-19 09:25 PM if you say so 20-Jul-19 09:25 PM But not certified 20-Jul-19 09:25 PM meh.. I dont need to be certified in watchmaking at the end of the day 20-Jul-19 09:25 PM I dont want to work in a service center.. 20-Jul-19 09:25 PM I want to make watches.... hence the machine(s)! 20-Jul-19 09:25 PM no cert needed 20-Jul-19 09:25 PM but I know how to service watches at this point 20-Jul-19 09:26 PM Very cool goals 20-Jul-19 09:26 PM If I worked for someone I would have been certified by my employer 20-Jul-19 09:26 PM I was looking into that awhile back but watches dont quite do it enough for me 20-Jul-19 09:26 PM oh, yes, the age old debate on who gave the cert 20-Jul-19 09:26 PM and what standards does it represent 20-Jul-19 09:26 PM I guess I could certified myself? 20-Jul-19 09:26 PM Have any designs in the works, @Noxz ? 20-Jul-19 09:26 PM @LRM it's certainly a step back from more technical things 20-Jul-19 09:26 PM @AdamMcCombs , do you have business insurance? 20-Jul-19 09:27 PM I do carry a rider 20-Jul-19 09:27 PM yes, some designs, but I have some initial plans.. more so replicating vintage designs that are hard to get (but I have some of).. then once I establish a brand I can release my own thing 20-Jul-19 09:27 PM Nice, I have some similar plans with fly reels in the works but have other projects I am wrapping up first 20-Jul-19 09:28 PM So im thinking we have 2 easy options 20-Jul-19 09:28 PM so... @AdamMcCombs would you reccomend me to NOT go out and get an engine hoist (which I will eventually need fro my project car) tomorrow (which was the intiial plan) 20-Jul-19 09:28 PM I would not want to be anywhere near that machine and an engine hoist 20-Jul-19 09:28 PM btw, I do have a simple hydraulic floor jack for cars 20-Jul-19 09:29 PM Engine hoist seems like it would be hard to roll around that driveway 20-Jul-19 09:29 PM and I lifted a pretty good sized mill with a hoist not too long ago 20-Jul-19 09:29 PM yeah, really sucky driveway 20-Jul-19 09:29 PM unless the wheels were rubber + air 20-Jul-19 09:30 PM Option one is a forklift. The freight company will delivery the unit to ground level via pallet jack. We will use the fork lift to get the unit on the pallet up to the upper level then use a pallet jack to move the unit. We can get a narrow jack so we can roll the unit off the pallet onto blocks, the roll the jack under and pick it up, put it into place on blocks, then rock it back and forth on the blocks using a burk bar or j bar to get it on the ground 20-Jul-19 09:30 PM Option two is a roll back tow tuck and roll a lifts 20-Jul-19 09:33 PM btw the patio isnt exactly level and has some gravely spots 20-Jul-19 09:33 PM but a sheet of osb/ply would fix a bit of that 20-Jul-19 09:34 PM Freight company delivers the unit on pallet to grade level. We use rollers and blocks to get the unit down to grade level. Roll a lifts are then mounted to the sides of the unit and a roll back tow truck is brought in. The roll back is brought down to the unit and the winch mounted with a 2 point ridged strap rig to the roll a lifts. The unit is the rolled onto the roll back, roll back comes up to level with the patio and back up to it. Unit is then rolled from roll back to patio grade level and roll a lifts are used to get unite inside and placed on blocks. Burk bar or j bar is used to get off blocks. 20-Jul-19 09:34 PM You want to avoid osb in this at all cost. Very bad for rolling over. 20-Jul-19 09:34 PM This tends to happen a lot 20-Jul-19 09:34 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/6VMwcsNPYfCCILY7bW_BVapbP7USbEIb0XBVdiaybq-49F26.png 20-Jul-19 09:35 PM yeah.. not deisgned for that load 20-Jul-19 09:36 PM What you want is high density overlay plywood 20-Jul-19 09:36 PM for my 'scaffolding' for working ont he house I took a 4x8 ply and made two layers of 2x8 20-Jul-19 09:36 PM it seems to have held 200lbs just fine.. but 10+x that, meh 20-Jul-19 09:36 PM simply insertting that comment here like it is at all relavent 20-Jul-19 09:37 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Edits-400x243-4AB92.png 20-Jul-19 09:37 PM the stuff I have on hand is not that 20-Jul-19 09:38 PM HDO or MDO has a stack up with a hard top that is really good for rolling equipment on. Its commonly used for concrete forms as well due to its strength. 20-Jul-19 09:41 PM the rolback flatbed idea may not have enough room from the side.. but re-thinking about head-on (essentially above the rose, to the front of the house) 20-Jul-19 09:41 PM having the gaping hole between driveway and patio right now confuses me slightly, ie, misleading 20-Jul-19 09:42 PM Yeah thats why i was asking about blocking the road for a bit 20-Jul-19 09:42 PM if it isnt long, and not during rush hour or whatever, then tot he hell with anyone else 20-Jul-19 09:43 PM at 2500 lbs we would need a 11k forklift to pick it safely on the tips of the forks to clear the rose 20-Jul-19 09:43 PM man.. hindsight.. 20-Jul-19 09:44 PM We with a 6k lift we would need to get a lot closer to the edge of the patio 20-Jul-19 09:44 PM I also was simply asking the seller questions.. and all of a sudden he was like: to offset shipping charges, $300 off!... and had the deal posted publically or watever so if i didnt act on it, somene else may have 20-Jul-19 09:44 PM the fork truck is ~46 wide 20-Jul-19 09:45 PM the unit is hard to describe the dimensions, and I havent found too detail of it, beyond something like 55" wide and tall (76 long, but we can disregard that section since it is completly unsupported ont eh sides 20-Jul-19 09:46 PM I was just saying to see if you had clearance to the side of the rose 20-Jul-19 09:46 PM between the rose and the steps? 20-Jul-19 09:46 PM yeah 20-Jul-19 09:46 PM if we want to not nail the rose then i think a roll back is the best bet 20-Jul-19 09:46 PM or rig it and hire someone with a articulated lift 20-Jul-19 09:48 PM yeah, that may be slightly better when thinking more and more on it.. 20-Jul-19 09:48 PM I kinda liek the idea of rollback and just doing it ourselves (btw, there is a parking burm) 20-Jul-19 09:48 PM "ourselves" needs ot be in quotes there 20-Jul-19 09:48 PM and yay, typing is gone to hell 20-Jul-19 09:51 PM someone say OBS? 20-Jul-19 09:51 PM :P 20-Jul-19 09:51 PM get out 20-Jul-19 09:51 PM LOL 20-Jul-19 09:51 PM i still blame you 20-Jul-19 09:51 PM was that osb photo of a conmega move? 20-Jul-19 09:52 PM This is why we can't have nice things 20-Jul-19 09:52 PM sigh yes 20-Jul-19 09:52 PM Hey that OSB is still usefull as a ramp 20-Jul-19 09:52 PM I've used it a few times since 20-Jul-19 09:52 PM "ramp" 20-Jul-19 09:52 PM HEY IT GOES OVER TOP OF ALUMINUM RAMPS 20-Jul-19 09:52 PM its not like I use it by itself 20-Jul-19 09:52 PM alumoinum ramps is a neat idea.. home depot truck rental has 'em 20-Jul-19 09:52 PM no 20-Jul-19 09:52 PM LOL 20-Jul-19 09:52 PM Yea don't listen to us 20-Jul-19 09:52 PM what's being moved I don't feel like reading 4000 lines of scroll back 20-Jul-19 09:53 PM what if the truck is able to load the item into a lil pickup truck that we can drive however 20-Jul-19 09:53 PM 2500lbs thats what 20-Jul-19 09:53 PM OH LMAO 20-Jul-19 09:53 PM in a 4x4 ft footprint or so 20-Jul-19 09:53 PM we put that hole in that plywood with only like 800lbs 20-Jul-19 09:53 PM Yeah as i said no 20-Jul-19 09:53 PM lol 20-Jul-19 09:53 PM yea you need like half inch thick steel plate as a ramp 20-Jul-19 09:53 PM and you'll get run over with an incline over 0.5 degrees 20-Jul-19 09:53 PM aka 20-Jul-19 09:54 PM nah 20-Jul-19 09:54 PM get a forklift 20-Jul-19 09:54 PM well you see someone put a rose in the way of a forklift 20-Jul-19 09:54 PM hey, dude, it was a different plant before, a more ugly one 20-Jul-19 09:54 PM this one looks nice 20-Jul-19 09:54 PM it is a Hansa rose 20-Jul-19 09:54 PM sorry a rose? like a single flower? 20-Jul-19 09:54 PM the flowers a purple 20-Jul-19 09:54 PM it blooms all summer long 20-Jul-19 09:54 PM but they only last like 4 or 5 days 20-Jul-19 09:55 PM like as in, dig it up, put it in a pot, then do the move and re-plant 20-Jul-19 09:55 PM like if you said an entire flower bed ok... 20-Jul-19 09:55 PM hrmm... sure, if need be 20-Jul-19 09:55 PM Buy a new rose 20-Jul-19 09:55 PM but a SINGLE FLOWEr? 20-Jul-19 09:55 PM I'm moving in a year anyways 20-Jul-19 09:55 PM I mean 20-Jul-19 09:55 PM you can use OBS 20-Jul-19 09:55 PM Then we have a 6000lb fork lift and a 2500lb grinder on top of dirt 20-Jul-19 09:55 PM so, this puppy has got to come back out 20-Jul-19 09:55 PM soft dirt 20-Jul-19 09:55 PM its just you'll have an OSB flower at the end 20-Jul-19 09:55 PM ... 20-Jul-19 09:56 PM So im looking at a roll back truck. Im just checking capacity right now 20-Jul-19 09:56 PM passenger car size or something? 20-Jul-19 09:56 PM I wonder how nice of a guy the shipper owuld be to load it on said truck 20-Jul-19 09:57 PM I've used a rollback before... minute and I'll get a photo 20-Jul-19 09:57 PM CG is very low on this so with roll a lifts it should be no problem 20-Jul-19 09:57 PM ever hear dof ness campbell rigging? there is a truck with their name on it that I go past on many dog walks, chatted with the guy a few times, never about his jerb though, usually about my dog 20-Jul-19 09:57 PM https://i.imgur.com/DLbWfV0.jpg 20-Jul-19 09:57 PM 2500 really is not that bad 20-Jul-19 09:57 PM nah, cars weigh that easy 20-Jul-19 09:57 PM Used the roll-back hoist strapped around it to lower it 20-Jul-19 09:58 PM well we want to put it right and the end of it 20-Jul-19 09:58 PM this was from a box truck whom's lift gate was not big enough for the item... it was loaded at a loading dock 20-Jul-19 09:58 PM roll-backs have such menuverability, its like a loading dock with all the adjustments to go down to ground level lol 20-Jul-19 09:58 PM how can a lfitgate not be big enough for that? 20-Jul-19 09:59 PM just wasn't deep enough 20-Jul-19 09:59 PM Im thinking we are going to have to roll it back to the cab, then level it out and land the end of the roll back on the patio 20-Jul-19 09:59 PM the feet would have stuck off by like 4 inches 20-Jul-19 09:59 PM it sucked 20-Jul-19 09:59 PM Then we can roll it off the truck onto the patio 20-Jul-19 09:59 PM but I mean for like 100 bucks we got a rollback to unload it 20-Jul-19 09:59 PM so it was whatever 20-Jul-19 09:59 PM Conmega, what is that equipment? 20-Jul-19 09:59 PM Glue machine 20-Jul-19 09:59 PM seriously 20-Jul-19 09:59 PM like 20-Jul-19 09:59 PM https://i.imgur.com/97eh07Q.jpg 20-Jul-19 09:59 PM its for putting encapsulation around dies 20-Jul-19 09:59 PM hrmm 20-Jul-19 10:00 PM its a stupid overengineered massive glue machine 20-Jul-19 10:00 PM because... why not 20-Jul-19 10:00 PM Its easy you have a crappy lift gate like this 20-Jul-19 10:00 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/kywlJVgYHt68zd7epxn29ySkcPJz7xZc1xbnFuRyaV-92698.png 20-Jul-19 10:00 PM like, I need one of those 20-Jul-19 10:00 PM this is what happens to that kid who ate glue still going into college 20-Jul-19 10:00 PM Man you guys have all kinds of cool toys 20-Jul-19 10:00 PM eugh thats a worse lift gate than my friend's box truck 20-Jul-19 10:00 PM Yeah they wanted to move a sem with it 20-Jul-19 10:00 PM his is at-least full width and doesn't look as flimsy as a cookie sheet 20-Jul-19 10:01 PM That lift gate got added to the list of days that involved unexpected forklifts 20-Jul-19 10:02 PM lol 20-Jul-19 10:02 PM oh more photos 20-Jul-19 10:02 PM https://i.imgur.com/KURdRiy.jpg 20-Jul-19 10:02 PM worked pretty darn well 20-Jul-19 10:02 PM Because there was no way that this ridiculously top heavy feg sem was going to go up it 20-Jul-19 10:02 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/nMYRAEx6gkYivRbEYba5hOj2bFF_4ld_Mtb7LbyU0r-7A161.png 20-Jul-19 10:02 PM The things has like 500 lbs in just ion pumps at the top of the column 20-Jul-19 10:03 PM LOL 20-Jul-19 10:04 PM hrmmmm 20-Jul-19 10:04 PM so, rollback > forklift ? 20-Jul-19 10:05 PM uhm, no, cheaper 20-Jul-19 10:05 PM ah 20-Jul-19 10:05 PM forklift any day of the week 20-Jul-19 10:05 PM any minute of the day 20-Jul-19 10:05 PM I think in this application yes 20-Jul-19 10:05 PM If you dont want to move the rose 20-Jul-19 10:05 PM I actually may get a forklift for basically free 20-Jul-19 10:05 PM I dont know what that response was towards 20-Jul-19 10:05 PM with off-road tires 20-Jul-19 10:06 PM Rollback > forklift 20-Jul-19 10:06 PM okay.. 20-Jul-19 10:06 PM moving the rose isnt that big of a deal 20-Jul-19 10:06 PM but like, I've been ttending to it for 2+ years 20-Jul-19 10:06 PM kinda free, my friend got it for a few hundred bucks but moved from Albany, NY to VA so it got left at a friends place. Basically if I can get it down to my place in POK then I can use it lol 20-Jul-19 10:06 PM also, it has thorns.. 20-Jul-19 10:06 PM I think you should just recruit a dozen really strong guys off craigslist to carry it. 20-Jul-19 10:06 PM In that case fork lift... 20-Jul-19 10:06 PM Im still trying to figure out exactly how to strap the roll a lifts on 20-Jul-19 10:06 PM the little handles and what not protruding may cause problems 20-Jul-19 10:07 PM oh, you didnt see the other side which has the actual handle.. 20-Jul-19 10:08 PM Photos? 20-Jul-19 10:08 PM other side 20-Jul-19 10:08 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/s-l1600-A30C7.jpg 20-Jul-19 10:08 PM Photo of the over side? 20-Jul-19 10:08 PM that is the automatic lubrication handle 20-Jul-19 10:08 PM Where is the center of gravity front to back? 20-Jul-19 10:08 PM .. front? 20-Jul-19 10:08 PM front 20-Jul-19 10:08 PM Mmmmmm 20-Jul-19 10:08 PM with the table 20-Jul-19 10:09 PM Forklift is really not a bad idea 20-Jul-19 10:09 PM I think roll a lifts would work 20-Jul-19 10:09 PM But I could see having a problem straping on 20-Jul-19 10:09 PM what about putting wood blocking between the machine and rollalift on the side wit hthe handle? 20-Jul-19 10:09 PM or... remove the handle 20-Jul-19 10:10 PM The roll a lifts need to grip undernearth 20-Jul-19 10:10 PM oh, yeah, I have no idea what the body is formed as 20-Jul-19 10:10 PM 1/4" steel? 20-Jul-19 10:10 PM metric equivilent maybe 20-Jul-19 10:10 PM and by 1/4, mor elikely 1/8 or something 20-Jul-19 10:10 PM The CG needs to fall in-between the two feet on the roll a lift 20-Jul-19 10:10 PM which looking at that table being so far forwards might be a problem 20-Jul-19 10:10 PM the machine will have an instruciton manual delviered with it 20-Jul-19 10:10 PM but it will be in german 20-Jul-19 10:11 PM A fork lift will just for sure come undernearth 20-Jul-19 10:11 PM @Noxz, let me know as Thursday approaches if you need any help. 20-Jul-19 10:11 PM @piGuy do you speak german? 20-Jul-19 10:11 PM a few people on here do 20-Jul-19 10:11 PM they could help us translate the specs as to how to lift and move the machine 20-Jul-19 10:11 PM we can put down support material over the dirt and roll up to the patio just fine 20-Jul-19 10:12 PM maybe I hsould ask the company how they stuck it on the pallet, too 20-Jul-19 10:12 PM I know a little bit. :--) 20-Jul-19 10:12 PM like, how did they lift it, etc 20-Jul-19 10:12 PM jus tot gain insight as to how it behaves 20-Jul-19 10:12 PM I still need to make sure I'm available Thursday. 20-Jul-19 10:12 PM Not 100% on that 20-Jul-19 10:13 PM hah, yeah, well, in the end it may just be: pay the guy 20-Jul-19 10:13 PM but cant really have it in the street neither 20-Jul-19 10:13 PM for long 20-Jul-19 10:13 PM I'm not nearly as helpful as @AdamMcCombs , but I can get you a drink or 911 when something bad happens. 20-Jul-19 10:13 PM *dial 911 20-Jul-19 10:14 PM man, I've already called 911 afew times this week 20-Jul-19 10:14 PM I'm hoping after the conference my schedule will finally open up a bit. If it was then it would be easy. 20-Jul-19 10:15 PM front quarter shot, for reference 20-Jul-19 10:15 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/s-l1600-76E94.jpg 20-Jul-19 10:15 PM What about the other side? 20-Jul-19 10:15 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/s-l1600-2A6C6.jpg 20-Jul-19 10:15 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/s-l1600-C972B.jpg 20-Jul-19 10:16 PM Are you going to make watch parts with this thing? Seems huuuuuge for watch parts... 20-Jul-19 10:16 PM hahaha 20-Jul-19 10:16 PM it's basically an all purpose grinder 20-Jul-19 10:16 PM so, making jigs 20-Jul-19 10:16 PM and tools 20-Jul-19 10:16 PM not parts directly, but the tools and machines to make tiny watch parts 20-Jul-19 10:16 PM and cutters 20-Jul-19 10:17 PM I have a Sanford SG48 surface grinder. Smallest surface grinder ever made! 20-Jul-19 10:17 PM yeah, I kinda looked into small ones, but decided this ONE machine will do everything 20-Jul-19 10:17 PM ~24x12" of reach/travel of the beds 20-Jul-19 10:17 PM also, the price was right 20-Jul-19 10:17 PM sanfords were kinda pricey, upon initial gander 20-Jul-19 10:17 PM like, more than this thing 20-Jul-19 10:17 PM and I can do surface, ID, OD, and tool grinding 20-Jul-19 10:17 PM and it was made in switzerland 20-Jul-19 10:17 PM 2 HP motor ont he thing, just for ref 20-Jul-19 10:17 PM anywho, not comparing galiformes or anything.. 20-Jul-19 10:17 PM I love the idea of more universal machines.. if I had a dozen employees making me stuff then maybe having specific machines for ea purpose to not tie a single machine up would make sense.. but it's just me 20-Jul-19 10:17 PM okay.. so maybe leaving it at this point for the night, but it sounds like a forklift would be a better shot than not 21-Jul-19 08:47 AM discovered the generic name for roll-a-lift is 'lifting dolly' - but even that isnt quite universal 21-Jul-19 09:34 AM I got a Harig from a friend to try to fix. It had tipped over when they tried to move it. Upon getting it to my place and after fixing the obviously broken bits I found a fatal crack in the casting so out it went. Waiting for the scrap equipment guy to pick it up. He parts machines out. Still need a surface grinder. 21-Jul-19 10:08 AM doh! .. will be careful, overall the machine is relatively new (1980s, just shy of CNC) and appears to be in decent condition - so dont want it to fall or whichever 21-Jul-19 10:08 AM half wonderng if I can get a pair of lifting dollies for relatively cheap, as I may be moving machines often enough that having a set would be good to always have on hand 21-Jul-19 10:08 AM ~$700 USD for a pair doesnt sound ridiculous.. but I dont see any near by, and shipping appears to be 1-2 weeks out for most places 21-Jul-19 10:55 AM @Noxz , link to example lifting dollies? I'm curious... 21-Jul-19 10:56 AM https://www.homedepot.com/p/Vestil-4-000-lb-Capacity-Furniture-and-Crate-Movers-Hydraulic-MFM-4000/303210108 21-Jul-19 10:56 AM https://www.northerntool.com/shop/tools/product_200673748_200673748 21-Jul-19 10:56 AM Those aren't what you want 21-Jul-19 10:56 AM no? 21-Jul-19 10:56 AM what are they lacking? 21-Jul-19 10:57 AM beef probably 21-Jul-19 10:57 AM Look a little... anemic 21-Jul-19 10:57 AM Yeah 21-Jul-19 10:57 AM even though it's rated at 4k lbs? 21-Jul-19 10:57 AM No where near as robust as actual roll a lifts 21-Jul-19 10:57 AM harbor freight rates things for weights too 21-Jul-19 10:57 AM also working weight and max capacity are not anywhere near eachother 21-Jul-19 10:57 AM you might be-able to barely get a 4Klbs thing up on that, but you probably wouldn't want to try and move it 21-Jul-19 10:59 AM well, the thing is 2500lbs 21-Jul-19 10:59 AM Yeah the wheels on the roll a lifts are amazing and enable you to get away with a lot more than what the wheels on those one will 21-Jul-19 10:59 AM also, leaning more towards a set of these + roll-back flat bed onto the patio 21-Jul-19 10:59 AM The roll a lifts you can winch on to, those would not be safe to do 21-Jul-19 11:00 AM @AdamMcCombs know of a place in town that rents them? 21-Jul-19 11:00 AM Yeah I usually get them from star rentals 21-Jul-19 11:00 AM looking.. 21-Jul-19 11:01 AM Also unless you can get them flush up against the machine you are not going to be able to safely pick it up. Additionally the reason I was leaning towards the fork lift due to center of gravity concerns with the table 21-Jul-19 11:01 AM daily: $60, weekly, $230, hot damn 21-Jul-19 11:02 AM Man, I should get into the roll a lift rental business 21-Jul-19 11:02 AM yea for the once a year some crazy guy moving an SEM needs them :P 21-Jul-19 11:02 AM They are supper popular for safe moving 21-Jul-19 11:02 AM I guess the daily, or even weekly rate, outweighs buying a pair 21-Jul-19 11:02 AM hold up.. I know lockpickers who do safe stuff.. lemme ask them if anyone has any 21-Jul-19 11:03 AM Is it easy/possible to move heavy equipment with roll-a-lifts as a one man operation? 21-Jul-19 11:04 AM Yeah 21-Jul-19 11:04 AM You still have to get the thing about a half inch off of the ground 21-Jul-19 11:04 AM how often do you have someone come to you and immediately think of safely moving something Adam? 21-Jul-19 11:04 AM Not recommended thogh 21-Jul-19 11:05 AM :P 21-Jul-19 11:05 AM With the exception of you? 21-Jul-19 11:05 AM I think roll-a-lifts are extremely popular with you 21-Jul-19 11:05 AM :P 21-Jul-19 11:05 AM I dont have a toe jack or whatever it's called, just a simple car hydraulic jack.. may need to rent such a pry bar thing 21-Jul-19 11:05 AM I have a Burk bar 21-Jul-19 11:05 AM Though you may need a j bar for 2500 21-Jul-19 11:06 AM well, you are just tipping it at that point, right? 21-Jul-19 11:06 AM also, what about the pallet it is on? 21-Jul-19 11:06 AM Yeah 21-Jul-19 11:06 AM it's gotta come off the pallet? 21-Jul-19 11:06 AM (I know eventually) 21-Jul-19 11:06 AM @AdamMcCombs , forget a course on SEM basics, I want a course on moving heavy equipment. 21-Jul-19 11:06 AM I gave a talk on it at one point 21-Jul-19 11:06 AM It was supposed to be recorded but... Apparently that didn't happen 21-Jul-19 11:06 AM Anyways 21-Jul-19 11:06 AM Getting it of the pallet would be super easy with a forklift 21-Jul-19 11:06 AM All you have to do is block it up then pick it up 21-Jul-19 11:10 AM nods 21-Jul-19 11:18 AM k, so star rentals seems like a good source for roll-a-lifts, the flat bed would be most any towing company that is willing to do what I ask? what sucks is blocking the road for a little bit 21-Jul-19 11:20 AM Can you completely remove the lubricant pump? 21-Jul-19 11:20 AM I have no idea where it is actually located.. but I assume the handle comes off 21-Jul-19 11:20 AM the full manual [in german] will come with the machine.. 21-Jul-19 11:21 AM Im still not 100% on the roll a lifts being compatible with this 21-Jul-19 11:21 AM because of the center of gravity? 21-Jul-19 11:21 AM being front heavy 21-Jul-19 11:21 AM Yeah thats part of it 21-Jul-19 11:21 AM more so I think just... the rollalifts are supposed to sit against a flat side... 21-Jul-19 11:21 AM not some weird bed sticking out... 21-Jul-19 11:22 AM but the roll a lifts have to be perfectly flush against a flat side 21-Jul-19 11:22 AM https://i.ytimg.com/vi/3MZScyw9yJg/hqdefault.jpg 21-Jul-19 11:22 AM like that 21-Jul-19 11:22 AM @Conmega the sides are actually pretty flat.. there is a lever on one side to be avoided though 21-Jul-19 11:23 AM they look flat for the first like foot and a half? 21-Jul-19 11:23 AM repost.. https://media.discordapp.net/attachments/513115950501855261/602366157013385219/s-l1600.jpg?width=1292&height=969 21-Jul-19 11:23 AM oh jesus this thing is like 5 times deeper than I thought 21-Jul-19 11:23 AM 55 inches? 21-Jul-19 11:23 AM the other thing is normaly to get the CG back far enough you would move the table back, but doing that means you cant put the roll a lifts on 21-Jul-19 11:23 AM your first photos hide the back jut REALLY well 21-Jul-19 11:23 AM https://cdn.discordapp.com/attachments/513115950501855261/602367934660083712/s-l1600.jpg 21-Jul-19 11:23 AM the table does not move back 21-Jul-19 11:23 AM like... 21-Jul-19 11:23 AM the head moves back 21-Jul-19 11:24 AM im also not sure that its wide enough, and I donk know what is under the base 21-Jul-19 11:24 AM yeah, iunno 21-Jul-19 11:24 AM conmega, so the front/back ius not where you would put the roll-a-lift 21-Jul-19 11:24 AM would be the sides 21-Jul-19 11:25 AM I fully understand that 21-Jul-19 11:25 AM squints 21-Jul-19 11:25 AM I may have missed something 21-Jul-19 11:25 AM but I don't think that is going to work out well with the whole balancing the front/back and the stuff jutting out the sides 21-Jul-19 11:25 AM I am sure the manual talks about how to rig it.. 21-Jul-19 11:25 AM I asked due to scan it, and he said: 55 pages is too much, and some things liek electrical schems are foldout/larger than a page that can fit in his scanner 21-Jul-19 11:25 AM example 21-Jul-19 11:25 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/s-l1600-A5E6E.jpg 21-Jul-19 11:27 AM Yeah they way to rig it is just from the bottom 21-Jul-19 11:27 AM I wish they would have given me other pics 21-Jul-19 11:28 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-A1919.png 21-Jul-19 11:28 AM The other thing im woried about is I dont think a roll a lift will fit in this gap 21-Jul-19 11:29 AM going to have way too much weight up front I think there 21-Jul-19 11:29 AM Yeah that another unknown 21-Jul-19 11:29 AM the point here is... this machine was designed to be moved with other BIG machines, not our feats of engineering that allow us to cheat 21-Jul-19 11:29 AM If it were just on flat ground would not be a problem 21-Jul-19 11:29 AM human size relation 21-Jul-19 11:29 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/prospec-strausak-kellen-3-81A05.jpg 21-Jul-19 11:30 AM but we are talking about reversing it up a roll back truck at a angle... 21-Jul-19 11:30 AM and that when it could get unstable 21-Jul-19 11:30 AM I thought that thing looked a little small relative to the electrical box 21-Jul-19 11:30 AM yea no way a rollalift is fitting anywhere on that 21-Jul-19 11:30 AM oh? 21-Jul-19 11:30 AM unless you get the happy meal version 21-Jul-19 11:30 AM which uh 21-Jul-19 11:30 AM hrmm 21-Jul-19 11:30 AM think mcdonalds stopped offering those... forever ago lol 21-Jul-19 11:31 AM I believe it is 55" from the front to the back 21-Jul-19 11:31 AM right from the extremes 21-Jul-19 11:31 AM including that jut out the back 21-Jul-19 11:31 AM right, which is the electrical stuff 21-Jul-19 11:31 AM A roll a lift is 36 21-Jul-19 11:31 AM so, not particularly heavy 21-Jul-19 11:31 AM oh, yeah, this is more narrow than 36 I would say 21-Jul-19 11:32 AM Yeah so if that total depth we are def going to have problems getting the roll a lifts on 21-Jul-19 11:32 AM what about making cripples or something, to go from the edge of the rollalift up to the hump back 21-Jul-19 11:32 AM still front heavy, I bet 21-Jul-19 11:32 AM even if you move the head unit all the way back 21-Jul-19 11:33 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-15EA3.png 21-Jul-19 11:33 AM rollalift is over half the depth of that thing aka its going to cover about allllll of that area there probably 21-Jul-19 11:33 AM the table is 18" deep 21-Jul-19 11:33 AM 57 U 21-Jul-19 11:33 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/prospec-strausak-kellen-8-04764.jpg 21-Jul-19 11:33 AM wow, what a crummy shot 21-Jul-19 11:34 AM yea that looks about right the bed is about half the width of what I drew 21-Jul-19 11:35 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/prospec-strausak-kellen-8-F1E01.jpg 21-Jul-19 11:35 AM stop making me push my MS-paint skills 21-Jul-19 11:35 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-0FE67.png 21-Jul-19 11:35 AM lol 21-Jul-19 11:35 AM like seriously, you would have to be extremely lucky with the placement of the roll-a-lifts to get them to sit flush 21-Jul-19 11:36 AM what about wood blocks/"shims" ? 21-Jul-19 11:36 AM Problem is the feet that grab undernearth 21-Jul-19 11:36 AM yeah, how long are they? 21-Jul-19 11:37 AM http://www.airtoolequipment.com/485-thickbox_default/skarnes-rol-a-lift-rental.jpg 21-Jul-19 11:37 AM Just a few inches 21-Jul-19 11:37 AM not much 21-Jul-19 11:37 AM you could maybe afford to shim an inch..... 21-Jul-19 11:37 AM like they are not designed for that 21-Jul-19 11:37 AM meh, would still need to gank the lube handle off 21-Jul-19 11:37 AM does a shaft not just 21-Jul-19 11:37 AM stick out? 21-Jul-19 11:38 AM dude, I don't know 21-Jul-19 11:38 AM looks like it has a mounting thing on it 21-Jul-19 11:38 AM 4 bolts into the main body 21-Jul-19 11:38 AM but the hand wheels to the left of it, hrm 21-Jul-19 11:39 AM I would not be worried about a 1 inch shim, but the 2 sides of the lift still need to be in contact with the frame 21-Jul-19 11:39 AM I mean the other option is to just strap it to the pallet really damn well and pallet jack it maybe? not that it sounds like a safe idea but... 21-Jul-19 11:39 AM the are under a lot of force as well due to the strapping 21-Jul-19 11:39 AM That is an option Connor... 21-Jul-19 11:39 AM But... 21-Jul-19 11:39 AM Its not greate 21-Jul-19 11:40 AM never said it was great lol 21-Jul-19 11:40 AM The better way of doing that is to block it as well 21-Jul-19 11:40 AM that is true 21-Jul-19 11:40 AM I was just thinking about tilting when going down a flat bed 21-Jul-19 11:40 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/aPX0vOmGU4OIKeVV9iQlwHZ6DErF6D1y-JMMt6DG5r-8736D.png 21-Jul-19 11:40 AM That basicly what I did for this SEM 21-Jul-19 11:41 AM cute looks like my pallet jack 21-Jul-19 11:41 AM I dont know how they palletized it 21-Jul-19 11:41 AM For lift prob 21-Jul-19 11:41 AM the shot was from orig listing, not as shipped 21-Jul-19 11:41 AM aye, I really need food... bbiab 21-Jul-19 11:41 AM thanks for the help thus far 21-Jul-19 11:43 AM No problem 21-Jul-19 12:13 PM strawberries are 2x2lbs for $5 @ QFC 21-Jul-19 12:13 PM fyi 21-Jul-19 01:20 PM anyone know much about hoke gyrolok? 21-Jul-19 01:20 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20190721_132100-94EC2.jpg 21-Jul-19 01:20 PM the nut says "hoke gyrolok" on it 21-Jul-19 01:20 PM but I'm confused by the big tube sticking out 21-Jul-19 01:20 PM doesn't really seem consistent with any of the gyrolok drawings here http://catalog.hoke.com/Asset/Gyrolok-Tech-data.pdf 21-Jul-19 01:20 PM the OD of the tube is 0.75" 21-Jul-19 01:20 PM and the thread diameter is about 24 mm (hard to measure) 21-Jul-19 01:20 PM hmm maybe I could 3D print something for this before I waste money on fittings (it's not under vacuum) 21-Jul-19 01:20 PM I think it might just be NPT 21-Jul-19 01:56 PM If the tubing is 3/4" OD maybe just go with what the spec sheets say for the 3/4" OD fittings and print up a test piece 21-Jul-19 01:56 PM Does not look like they use tapered threads though... 21-Jul-19 05:56 PM Hoke is a long standing valve and fitting manufacturer. Gyrolock is their version of Swagelock type of thing. They make small vacuum valves of the quality of Nupro and such. http://www.hoke.com/Catalogs/Catalog_79104ENG_Condensed_Product_Catalog_09.2012.pdf 21-Jul-19 05:56 PM There is pretty good info on it In this catalog. 22-Jul-19 05:16 PM looks like my machine is already at the terminal like 30mi south of here.. I hope they dont try to deliver it sooner and will stick with a thursday delivery date.. 22-Jul-19 05:16 PM also, fellow student who has machines says that he disassembles and uses enigine hoists all the time 22-Jul-19 05:16 PM easier when it weighs less 22-Jul-19 05:30 PM Of if it's close by you might be able to pick it up yourself 22-Jul-19 05:30 PM Use a lift gate truck to get it from the terminal then use the lift gate to put it on the platform 22-Jul-19 05:35 PM hrm.. ryder lifts cant do 2500lbs? 22-Jul-19 05:35 PM also, I paid shipping through the seller of the item 22-Jul-19 05:35 PM so, I already paid for residential+liftgate 22-Jul-19 05:36 PM Yeah 22-Jul-19 05:36 PM But this might be easier 22-Jul-19 05:36 PM hrm, maybe 22-Jul-19 05:36 PM Because you might be able to just set it on the patio 22-Jul-19 05:36 PM right 22-Jul-19 05:36 PM Ryder can be hit or miss sometimes 22-Jul-19 05:37 PM it was simply noted from a picture posted over the weekend 22-Jul-19 05:37 PM At 2500 lbs 22-Jul-19 05:38 PM roger 22-Jul-19 05:38 PM I think the ford Penskes can do 2500 22-Jul-19 06:27 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0472-71DC3.JPG 22-Jul-19 06:27 PM grade at the front of the garage to patio 22-Jul-19 06:27 PM just for the sake of the shot 22-Jul-19 06:27 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0473-C78D9.JPG 22-Jul-19 06:27 PM and remainder of the driveway.. 22-Jul-19 06:27 PM doesnt seem too bad to lay even a 4x4 or something down to level it.. if the shipping company would/is capable of brining it to there 22-Jul-19 06:27 PM but, who knows what they have/wil bring with them 22-Jul-19 11:00 PM Chop it up into 50lb pieces and then weld it back together. 23-Jul-19 07:54 AM Shame it can't just go in the garage? I hope the entire house is on a concrete slab... Because oh man if the floor is just rafters/beams... Uh... Machine will probably find the ground real quick lol 23-Jul-19 07:54 AM Houses were not built for machines like this... Heaviest thing they expect through is probably a fridge lol 23-Jul-19 09:33 AM The base floor is concrete.. And garage is too small with project car ( which cant really go on the street without proper tags) 23-Jul-19 09:33 AM The house is like half underground.. So there is decent foundation, standard house concrete is assumed at like 1500psi iirc.. I have notes from house reno stuff that I still need to complete 23-Jul-19 04:34 PM my notes say 2500psi concrete is a fair assumption for renovations/structural planning... so plenty of load for that machine 24-Jul-19 05:51 AM I also need to know if people will be available for this tomorrow - otherwise I need to get that engine hoist tonight 24-Jul-19 10:09 AM I can't help but put on my engineering hat and note that 2500psi concrete won't support anything if it's paper thin. 24-Jul-19 11:52 AM true.. my house is a 4" slab on grade.. says the orig building plans 24-Jul-19 11:52 AM I should be good 24-Jul-19 04:46 PM @AdamMcCombs availability status of tomorrow? 24-Jul-19 05:03 PM Any idea what time it is arriving? 24-Jul-19 05:05 PM Nope.. But it's not going to go anywhere if early (without me or help) 24-Jul-19 05:05 PM ie, if you are busy till later, it will still be there later 24-Jul-19 05:05 PM or inside if I figure that part out.. as I am pretty sure I should jus tpickup that hoist now anyways, especially since I am doing engine work (biodiesel stuff) anyways 24-Jul-19 05:05 PM (it's on the list of things to get for othe rprojects) 24-Jul-19 05:05 PM also, dog walk time.. be back in an hour or so 24-Jul-19 05:58 PM So.. Seafair preparade is going on 24-Jul-19 05:58 PM When? 24-Jul-19 06:45 PM Is the preparade going to cause problems tomorrow? 24-Jul-19 06:55 PM Now, greenwood, i think it is one day 24-Jul-19 07:24 PM actual seafair is this weekend.. I think saturday downtown 24-Jul-19 07:24 PM also, about to go get that engine hoist.. 24-Jul-19 07:34 PM Sorry I still don't know what I'm doing tomorrow and without a time it's hard. 24-Jul-19 07:44 PM aye, no worries, I had this other plan in the works from the get go.. just have to be careful.. and if I need to take it apart into pieces.. I will 24-Jul-19 07:44 PM thanks anywho 24-Jul-19 08:52 PM hah, so the one that the auto store had was the assembled model 24-Jul-19 08:52 PM okay, makes my job a little easier... but I do need to tighten all of the nuts/bolts 24-Jul-19 09:03 PM Remember that those hoist may not do very well with dynamic loads 24-Jul-19 09:04 PM understood 24-Jul-19 09:04 PM the distance it must move is very small 24-Jul-19 09:04 PM "small" 24-Jul-19 09:04 PM big machine.. 24-Jul-19 09:04 PM "big" 24-Jul-19 09:05 PM If you can take the fence down see if the freight company could just use the patio as a loading dock 24-Jul-19 09:05 PM I didn't think about framing it as a loading dock before. Might be the magic words to use with the freight company 24-Jul-19 09:07 PM ahhh, yes 24-Jul-19 09:07 PM that was essentially the idea with the rollback tow 24-Jul-19 09:07 PM all depends on how big of truck they bring, because traffic will be diverted in at least the northbound lane 24-Jul-19 09:08 PM Yeah but with a lift gate you are not having to tilt it at all 24-Jul-19 09:09 PM sure 24-Jul-19 09:09 PM it's agreat idea 24-Jul-19 09:09 PM I would not be afraid to insist upon that 24-Jul-19 09:09 PM yeah dude 24-Jul-19 09:09 PM That would make everything so easy 24-Jul-19 09:09 PM Just be sure they land the gate ontop of the surface very carfully 24-Jul-19 09:09 PM If done wrong it can tip the gate back 24-Jul-19 09:10 PM the surface isnt exactly flat neither 24-Jul-19 09:10 PM designed for rainwater runoff and such 24-Jul-19 09:10 PM and I used that word, designed, very loosely 24-Jul-19 09:12 PM If the machine is not blocked on the pallet right be very carful about it slipping of 24-Jul-19 09:12 PM If the pallet jack gets caught up on something it can cause the load to slip forward 24-Jul-19 09:13 PM hrm 24-Jul-19 09:13 PM standard common sense here (but thank you for noting it) 24-Jul-19 09:13 PM is being strapped to the pallet completely different than blocked? 24-Jul-19 09:13 PM ie,s traps break 24-Jul-19 09:14 PM Straps rely mostly on friction to keep it from sliding 24-Jul-19 09:14 PM Blocks well... Block it. 24-Jul-19 09:14 PM If you have a few cut up 2x4s and a screw gun you can block it really fast 24-Jul-19 09:15 PM I have wood on hand.. I could block it in myself 24-Jul-19 09:15 PM yeah, I got plenty of dimensional lumber on hand 24-Jul-19 09:15 PM house work and all 24-Jul-19 09:15 PM That usually what I do if I suspect it will be a problem 24-Jul-19 09:18 PM I still have to prep the area.. I wasnt planning on the parade eating time 24-Jul-19 09:18 PM I prepped most of it a few days ago, but still stuff to mvoe around 24-Jul-19 09:18 PM a lot of chemistry stuff 24-Jul-19 09:18 PM oh, also need to move the diesel enigne and the surface plate 24-Jul-19 11:28 PM Good luck tomorrow, @Noxz 24-Jul-19 11:29 PM gee thanks 24-Jul-19 11:29 PM Interested to see what you end up doing 24-Jul-19 11:29 PM it will depend on the truck driver, I think 24-Jul-19 11:29 PM Hopefully everything goes smoothly and no major issues 24-Jul-19 11:29 PM That is always a crap shoot 24-Jul-19 11:30 PM yeah, I Just have to be smart and careful 24-Jul-19 11:30 PM Did you have a chance to get the manual to see about any rigging instructions? 24-Jul-19 11:30 PM the manual will come with the machine 24-Jul-19 11:30 PM Ahh ok 24-Jul-19 11:30 PM so, I could flip through it (in german) and check out what they say 24-Jul-19 11:31 PM Use google translate on a smartphone, works wonders for translations on the fly if you are fluent in word sala 24-Jul-19 11:31 PM *salad 24-Jul-19 11:31 PM yeah, I recently got a full german book on watchmaking stuff from 1894 that I am doing that to 24-Jul-19 11:31 PM oooh fun! 24-Jul-19 11:33 PM I've basically been arguing with other students about a certain aspect that our "main" textbook spends about half a page on, and why do we not follow it (which is the page after the method we do) and simply wanted more info on it, and to prove the point 24-Jul-19 11:34 PM interesting, can you elaborate a bit because now you have me curious haha 24-Jul-19 11:34 PM regarding the inner pinning point of the hairspring of a watch.. 24-Jul-19 11:34 PM we learn to have it in line w/ the regulating pins (the LeRoy method).. but a page later in our textbook says: that's all great and such, but smaller watches dont have that affect and you should do it this other way 24-Jul-19 11:34 PM basically having it in line creates a full coil 24-Jul-19 11:34 PM and we are supposed to get a gain (increase in rate) with full coils at lower amplitudes 24-Jul-19 11:34 PM ie, the watch runs faster as it runs down on power 24-Jul-19 11:34 PM which is desirable, so you are early not late 24-Jul-19 11:34 PM amongst other reasons 24-Jul-19 11:34 PM the full coil idea works based on the change of the center of gravity as the hairspring changes shape (mass moves) 24-Jul-19 11:34 PM what my book/argument states though, is that newer stuff is not affected by gravity as much, that the hairspring overpowers it, and ot pin at 90 deg 24-Jul-19 11:34 PM and I found only one real technical reference as to what/why.. 24-Jul-19 11:34 PM beyond the book 24-Jul-19 11:34 PM which is in german.. 24-Jul-19 11:34 PM if only I knew some german speaking people... >_> 24-Jul-19 11:34 PM +google translate 24-Jul-19 11:38 PM that seems like something that would be more commonly encountered than just an obscure little half page bit 24-Jul-19 11:39 PM well... most of the hairsprings I have looked at (new) from one mfgr has the pinning in line, but it is a large movement, not small 24-Jul-19 11:39 PM but yeah... not much reference 24-Jul-19 11:39 PM and lots of secrets of the trade are... wel... secrets 24-Jul-19 11:40 PM my knowledge of horology goes about as far as knowing "horology" and knowing a guy ages ago who did clock repair so this is all a bit over my head 24-Jul-19 11:40 PM everyone is making high end hairsprings out of silicon these days, too 24-Jul-19 11:40 PM All simulated and FEA etc 24-Jul-19 11:40 PM yeah, I tried to dumb it down a little 24-Jul-19 11:40 PM ie, full coils give a gain at smaller amplitudes 24-Jul-19 11:41 PM If you run into any big problems just stop tarp it. Il make time on Friday if you really need it. 24-Jul-19 11:41 PM when the center of gravity moes... but does that matter? or rather, how much of an effect does it have 24-Jul-19 11:41 PM @AdamMcCombs thanks dude.. I do have a tarp 24-Jul-19 11:42 PM At that point I think that the solutions is going to be a forklift but heres hoping the driver just lets you use the thing as a loading dock 24-Jul-19 11:42 PM hah, yeah 24-Jul-19 11:42 PM the street/sidewalk doesnt give too much to play with.. so maybe not 24-Jul-19 11:42 PM if he comes in a semi? nope 24-Jul-19 11:43 PM I mean... Yeah. 24-Jul-19 11:43 PM plus there is a fire hydrant nearby 24-Jul-19 11:43 PM In my experince local deliveries are done by a 16 or 24 straight truck 24-Jul-19 11:43 PM probably a 24 24-Jul-19 11:43 PM I'm optimistic about being able to do it with the simple tools I have 24-Jul-19 11:43 PM Just dont do anything @Conmega would do 24-Jul-19 11:44 PM riiight 24-Jul-19 11:44 PM if the thing is dropped off between the stairs and the rose, I could potentially just raise it up and into the patio (after rippinga litttle fence down) 24-Jul-19 11:44 PM there's a lot of IFs 24-Jul-19 11:44 PM dependant on driver 24-Jul-19 11:44 PM I think I am about done for th enight, I did a little more cleaning/arranging down there, plus I tightened all the bolts on the hoist 24-Jul-19 11:46 PM If you want to use that as a loading dock the fence is already going to need to be down 24-Jul-19 11:47 PM yup, the fence is rotten and I was planning on replacing it with a gabion this summer anyways 24-Jul-19 11:47 PM Also moving the thing with a pallet jack on flat ground is supper easy 24-Jul-19 11:47 PM "flat" 24-Jul-19 11:48 PM A pallet jack will do fine on that rock 24-Jul-19 11:48 PM How tall is your patio? 24-Jul-19 11:48 PM 5 steps? 24-Jul-19 11:48 PM A loading dock is normaly 48 inches 24-Jul-19 11:48 PM way less than that 24-Jul-19 11:49 PM Ok perfect 25-Jul-19 12:00 AM wait noxz are you in bay area 25-Jul-19 12:00 AM slash adam 25-Jul-19 12:01 AM I used to be, but I am in seattle now 25-Jul-19 12:01 AM ah okay 25-Jul-19 12:01 AM I was in San Jose for about 5 years up untill about 3 years ago 25-Jul-19 12:01 AM Yeah im Seattle ish as well 25-Jul-19 12:02 AM so, the top of the 'lip' (more of a retaining/parapet of the patio) is about hip height, but the patio level is like theigh height 25-Jul-19 12:02 AM 36" or under for it all 25-Jul-19 12:02 AM but yeah 25-Jul-19 12:02 AM that was the measurement standard at the dog walk 25-Jul-19 12:02 AM anywho, time for bed 25-Jul-19 12:02 AM cheers 25-Jul-19 12:04 AM Night 25-Jul-19 05:35 AM Yea tbh the truck should be-able to back right up to the patio with the lift gate sticking out and it should be right on the correct level with how short your driveway/yard is and the incline change and how far out the back of the truck sticks out... 25-Jul-19 05:35 AM The only problem will be the railing around the patio, tear that down now... 25-Jul-19 06:00 AM hrmm 25-Jul-19 06:03 AM Like remember the rear wheels of the truck aren't at the back of the truck 25-Jul-19 06:03 AM they are a good distance under... so the back of the truck would hit the house before it even started to go up your nasty ramp of a driveway 25-Jul-19 06:03 AM So you should be-able to get the truck backed up to the patio without railing around it... Get the lift gate out, and get the machine onto the lift gate then bring the lift gate down to level with the patio or even sit on it slightly, and roll it onto the patio 25-Jul-19 06:03 AM That should actually be super easy 25-Jul-19 06:03 AM and you won't crush your rose... just be sitting over it is all 25-Jul-19 06:03 AM But oh nvm don't listen to me, apparently you don't want to do anything I'd do >.> @AdamMcCombs 25-Jul-19 06:11 AM biggest deal would be to dodge the retaining wall fo r the bridge I am half under 25-Jul-19 06:11 AM but that is up o the driver 25-Jul-19 06:11 AM I should measure that distance real quick 25-Jul-19 06:14 AM ??? I am confused 25-Jul-19 06:14 AM truck should just be-able to back up on the stree straight to the patio... probably block the street for awhile so I hope your not on a busy street otherwise you'll have to be quick 25-Jul-19 06:14 AM you'll only be-able to line it up so much with the patio due to the wall on the stairs there... 25-Jul-19 06:15 AM I live near a bridge 25-Jul-19 06:15 AM but the what 4ft? wide you have there should JUST be enough 25-Jul-19 06:15 AM an overpass 25-Jul-19 06:15 AM from house plans looks like the width is like 8ft 25-Jul-19 06:15 AM is that bridge in your front yard??? 25-Jul-19 06:15 AM from the steps to teh edge 25-Jul-19 06:15 AM it is diagonal? 25-Jul-19 06:15 AM I'll get a better pick during dog walk soon 25-Jul-19 06:15 AM retaining wall 25-Jul-19 06:15 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0468-9D2AB.jpg 25-Jul-19 06:15 AM y you so smoll 25-Jul-19 06:15 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0468-B8C95.jpg 25-Jul-19 06:15 AM so the edge of where the retaining wall starts, to the edge of the rose/drive/patio is like only 8ft 25-Jul-19 06:18 AM you mean the wall for the stairs? 25-Jul-19 06:18 AM I dunno if I'd call that quite a retaining wall but you have plenty of freaking space there 25-Jul-19 06:18 AM this is going to be so easy 25-Jul-19 06:18 AM I could unload that thing by my scrawny self there 25-Jul-19 06:18 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-9175D.png 25-Jul-19 06:18 AM Here is a HORRIBLE drawing of what I mean 25-Jul-19 06:18 AM that is what your doing 25-Jul-19 06:18 AM remove whatever stupid tall ass fence is on the patio 25-Jul-19 06:18 AM and your going to have the truck back up right there 25-Jul-19 06:18 AM thats the only simple way your going to do this 25-Jul-19 06:18 AM just god who thought it was a good idea to put that massive fence?!?! on a patio??!? 25-Jul-19 06:18 AM like whats the point of the patio now? 25-Jul-19 06:18 AM you can't even see out your damn windows!!! 25-Jul-19 06:20 AM there was one tiny window in the entry (kitchen-ish) area before 25-Jul-19 06:20 AM like that should just be a little steel railing lol 25-Jul-19 06:20 AM also, it isnt a view 25-Jul-19 06:20 AM Thats not the point?!?? 25-Jul-19 06:20 AM also, that wall goes up to like 20+ ft 25-Jul-19 06:20 AM The point is to let sun in 25-Jul-19 06:20 AM wall? 25-Jul-19 06:20 AM it still gets sun, the houses on the other side of the street block it ebfore it gets to the level of the fence 25-Jul-19 06:20 AM Ok anyway, I won't argue house design 25-Jul-19 06:21 AM I didnt design it 25-Jul-19 06:21 AM the point is do you see what I am saying? 25-Jul-19 06:21 AM and housing is hard to get in seattle 25-Jul-19 06:21 AM for unloading? 25-Jul-19 06:21 AM yeah, absolutely 25-Jul-19 06:21 AM Cool. 25-Jul-19 06:21 AM I think that is your best course of action, @AdamMcCombs can review when hes around 25-Jul-19 06:21 AM it's more a question on if 8ft space between the start of the wall and end of the patio is wide enough for a truck 25-Jul-19 06:21 AM But eugh Seattle, I can barely stand Poughkeepsie, NY lmao 25-Jul-19 06:21 AM and housing is like quarter to half the price haha 25-Jul-19 06:22 AM there is a reason I am going back to ohio in one year 25-Jul-19 06:22 AM that, and, well, the people 25-Jul-19 06:22 AM Doesn't need to be wide enough for a truck? 25-Jul-19 06:22 AM just for the machine 25-Jul-19 06:22 AM the lift gate can stick out over the driveway 25-Jul-19 06:22 AM who cares 25-Jul-19 06:22 AM just needs to be wide enough for the pallet to get onto the patio 25-Jul-19 06:22 AM which it looks like you have AT-LEAST 4 ft there 25-Jul-19 06:22 AM you should be fine 25-Jul-19 06:22 AM Also your moving back to Ohio??? why did you buy a big thing now then? lol 25-Jul-19 06:22 AM Ohio has like all the industrial surplus in the world 25-Jul-19 06:22 AM HGR Inc man... 25-Jul-19 06:22 AM they get anything from entire steel mills for sale surplus, not kidding millions of dollars, down to SEMs 25-Jul-19 06:22 AM like... man I would have waited haha 25-Jul-19 06:22 AM HGR is like 25-Jul-19 06:24 AM there is a drop into the patio 25-Jul-19 06:24 AM 2 super walmarts of surplus machining equipment/electronics/robotics/whatever you name it 25-Jul-19 06:24 AM of like 6 inches 25-Jul-19 06:24 AM I have two machines waiting for me at HGR 25-Jul-19 06:24 AM OK I am confused what is the patio? 25-Jul-19 06:24 AM this machine comes from michigan (orig switzerland) 25-Jul-19 06:24 AM lemme get a shot from this window... 25-Jul-19 06:25 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-F6973.png 25-Jul-19 06:25 AM This is the patio to me 25-Jul-19 06:25 AM sure 25-Jul-19 06:25 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0480-4F4F3.JPG 25-Jul-19 06:25 AM this is where your truck will back up to and you will use the lift gate to get level and just roll the machine onto 25-Jul-19 06:25 AM that is a terrible shot 25-Jul-19 06:25 AM the top of the retainer wall of the patio (diff wall here) is like 6" above the ground level of the patio 25-Jul-19 06:25 AM so, if the liftgate falls onn that, it will not touch anything but 4" of concrete 25-Jul-19 06:27 AM first off, wtf why the heck did they keep like a few square feet of dirt instead of just pouring it all concrete 25-Jul-19 06:27 AM and be 6" off a ground 25-Jul-19 06:27 AM also your not unloading there 25-Jul-19 06:27 AM I thought we were not talking about house design... 25-Jul-19 06:28 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-9A591.png 25-Jul-19 06:28 AM Right there 25-Jul-19 06:28 AM is that not level concrete? 25-Jul-19 06:29 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0480-93787.jpg 25-Jul-19 06:29 AM that part is higher 25-Jul-19 06:29 AM what the ACTUAL afjldsafds, did 40 contractors molest this poor house? 25-Jul-19 06:29 AM uhg how high is the lip? 25-Jul-19 06:29 AM like 6" 25-Jul-19 06:29 AM it varries 25-Jul-19 06:29 AM one moment... 25-Jul-19 06:30 AM WTF 25-Jul-19 06:30 AM Ok I have no idea how you'd handle that other than some wedge ramp build like super strong 25-Jul-19 06:31 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0481-A1D2E.JPG 25-Jul-19 06:31 AM raised concrete border 25-Jul-19 06:31 AM WTH??? 25-Jul-19 06:31 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0482-3F92B.JPG 25-Jul-19 06:31 AM sloped 25-Jul-19 06:31 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0483-E1AB1.JPG 25-Jul-19 06:31 AM Get a company out there and get another few yards of concrete poured 25-Jul-19 06:31 AM like wtf, finish the job someone never did 25-Jul-19 06:32 AM .. I'm at the sidewalk dude... 25-Jul-19 06:32 AM no more space left in seattle 25-Jul-19 06:32 AM ????? 25-Jul-19 06:32 AM I mean within the retaining wall there 25-Jul-19 06:32 AM it's all taken 25-Jul-19 06:32 AM to get it up to level 25-Jul-19 06:32 AM heh 25-Jul-19 06:32 AM wtf are you talking about? 25-Jul-19 06:32 AM that should be your property, just get it leveled up 25-Jul-19 06:32 AM like wth 25-Jul-19 06:33 AM yeah, I didnt design it 25-Jul-19 06:33 AM Also that looks more like a foot to me 25-Jul-19 06:33 AM not 6 inches 25-Jul-19 06:33 AM only thing I could think at this point 25-Jul-19 06:33 AM get a ton of cinder blocks and bricks... 25-Jul-19 06:33 AM and put them down in that area 25-Jul-19 06:33 AM then lay plywood on top 25-Jul-19 06:33 AM maybe some 2x4 chunks for better leveling 25-Jul-19 06:33 AM and just build out a wood deck basically 25-Jul-19 06:33 AM to get the machine on and level with the door its going through 25-Jul-19 06:33 AM thats my last suggestion, otherwise, wait for Adam to get there and let him help you with this madness haha 25-Jul-19 06:33 AM Like even a forklift won't save you here 25-Jul-19 06:33 AM I'm sorry but there is NO WAY a forklift will do anything for you here 25-Jul-19 06:33 AM you couldn't even drop the pallet up there with a forklift due to those walls 25-Jul-19 06:35 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0484-57015.JPG 25-Jul-19 06:35 AM @AdamMcCombs your boned bud, this is going to make my unload look easy 25-Jul-19 06:35 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0485-70E94.JPG 25-Jul-19 06:35 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0486-B2E99.JPG 25-Jul-19 06:35 AM I meant a foot in that corner 25-Jul-19 06:35 AM that's a good shot 25-Jul-19 06:35 AM yeah, like 9" I guess 25-Jul-19 06:35 AM thats crazy 25-Jul-19 06:35 AM excuse the trash 25-Jul-19 06:35 AM thats just 25-Jul-19 06:35 AM wth 25-Jul-19 06:36 AM you want a level border... but you need a slope for rain runoff 25-Jul-19 06:36 AM they didnt do 1/4" grade stuff back then 25-Jul-19 06:36 AM uhhh 25-Jul-19 06:36 AM thats a joke 25-Jul-19 06:36 AM seriously? 25-Jul-19 06:36 AM HAHAHAHA... I dont get it 25-Jul-19 06:36 AM thats not even funny man, there is no reason to put a grade for RUNOFF 25-Jul-19 06:36 AM INTO A WALL 25-Jul-19 06:37 AM there are spouts/holes for it 25-Jul-19 06:37 AM it diverts water away from the house 25-Jul-19 06:37 AM Look, either level it with concrete, or again, get some 2x4s/bricks/cinder blocks/something 25-Jul-19 06:37 AM while still looking straight 25-Jul-19 06:37 AM and a good shet of plywood 25-Jul-19 06:37 AM I got plenty of 2x4s 25-Jul-19 06:37 AM and level it up with the door and the wall 25-Jul-19 06:37 AM you'll want support like every 6 inches under that plywood minimum 25-Jul-19 06:37 AM more like ever 4 inches 25-Jul-19 06:37 AM basically 25-Jul-19 06:38 AM sure 25-Jul-19 06:38 AM your building a floor our of all the other bits 25-Jul-19 06:38 AM the plywood is just to really close up any small gaps 25-Jul-19 06:38 AM otherwise you will punch through, the pallet will topple, and you'll get a machine punching a hole in the side of the house. 25-Jul-19 06:38 AM just what I want 25-Jul-19 06:38 AM and here I was scared a car would run over the bridge and into the house.. 25-Jul-19 06:38 AM but it'll just be me moving a machine 25-Jul-19 06:38 AM k, well some advice and so forth.. 25-Jul-19 06:38 AM thanks 25-Jul-19 06:38 AM and yeah, it's all goofed 25-Jul-19 06:38 AM the house is a triangle if you look at it overhead 25-Jul-19 06:38 AM because of that bridge/overpass thing 25-Jul-19 06:38 AM which comes in at an angle 25-Jul-19 06:38 AM k.. dog walk time 25-Jul-19 07:35 AM time to finish prepping the path + destination, I suppose 25-Jul-19 09:16 AM Uh yeah that's quite the problem 25-Jul-19 09:16 AM I'm really not sure regular plywood should be used at all 25-Jul-19 09:16 AM How were you planning to get an engine hoist to reach out over that? 25-Jul-19 09:16 AM If you can get some of that HDO stuff to use as a topper 25-Jul-19 09:16 AM I think with that much weight a pallet jack is just going to punch through almost anything 25-Jul-19 09:23 AM I am not planning on building a platform 25-Jul-19 09:23 AM Almost anything meaning most types of less dense plywood 25-Jul-19 09:23 AM So how are you getting it off? 25-Jul-19 09:23 AM The pallet jack needs to roll off the lift gate 25-Jul-19 09:24 AM I am pretty sure I will have the dude drop it at the stairs (between the rose) or if we can get it up the garage, plant it in front of there.. then I can hoist it around myself at that point 25-Jul-19 09:24 AM I am still waiting on slings and whatnot to be delivered, so there's that 25-Jul-19 09:25 AM But a hoist needs to have wheels fully under the load 25-Jul-19 09:25 AM They don't use a counter balance 25-Jul-19 09:26 AM and I am not heavy enough for a counterbalance 25-Jul-19 09:26 AM a bit of this is still hindsight scenario 25-Jul-19 09:26 AM not that I am going to anything stupid/unsafe 25-Jul-19 09:26 AM I'll take time, and figure it out as the truck arrives, I think 25-Jul-19 09:27 AM So are you planning on having the wheels hang off the edge? 25-Jul-19 09:28 AM there isnt exactly a "plan" 25-Jul-19 09:28 AM the 'worst' case scenario is take off large pieces 25-Jul-19 09:28 AM then the base will be more manageable 25-Jul-19 09:28 AM Yeah but the casting is still several k 25-Jul-19 09:28 AM I got all day.. who knows when it'll be delivered 25-Jul-19 09:28 AM sure 25-Jul-19 09:29 AM Are you sure the car can't move? 25-Jul-19 09:29 AM there is too much on/around it 25-Jul-19 09:29 AM Just to enter through the garage door 25-Jul-19 09:29 AM it rolls, but it would take all day to clear it 25-Jul-19 09:29 AM umm, the garage -> house entrance wont work 25-Jul-19 09:29 AM Because this is a really hard problem 25-Jul-19 09:29 AM Hm 25-Jul-19 09:29 AM 3ft door 25-Jul-19 09:29 AM maybe 4? but the hallway you go into is tiny 25-Jul-19 09:32 AM Ok look up adjustable height portable A frame Gantry 25-Jul-19 09:32 AM oh, yeah, that would be nice to have 25-Jul-19 09:32 AM + a winch 25-Jul-19 09:33 AM You can rent them 25-Jul-19 09:33 AM I am fairly sure when I move back to ohio, and the art studio's load is verified with the engineer.. I will be paying a rigging company to move it all 25-Jul-19 09:33 AM star rentals? 25-Jul-19 09:36 AM Don't know 25-Jul-19 09:36 AM Haven't had to rent one, just used some one elses 25-Jul-19 09:42 AM I guess time to do homework while I wait 25-Jul-19 09:44 AM Anyways I'm going to be afk for a few hours. If you have any questions let me know 25-Jul-19 09:44 AM Maybe getting a small crane or a articulated arm truck is worth it 25-Jul-19 09:47 AM yeah, I am all for throwing money at getting it up and in safely/easily.. but almost want/need to see it in person first 25-Jul-19 09:49 AM Yeah as you said you have a tarp 25-Jul-19 09:50 AM yup.. going to be a hotter one today, 78F forecasted here.. 80 tomorrow, and a little drizzle on saturday (71) 25-Jul-19 09:52 AM When does your machine come today, Noxz? 25-Jul-19 09:52 AM dunno, no calls yet 25-Jul-19 09:53 AM One last thought. If you want to level off the porch you could use sand, compact that down really good then out HDO on top 25-Jul-19 09:53 AM hrmm.. noted 25-Jul-19 09:54 AM You would need to be very careful as there is some pitfalls but it could work 25-Jul-19 09:54 AM I really dont like the concrete 25-Jul-19 09:54 AM Well jack hammer then 25-Jul-19 09:55 AM yeah, that has been figured into renovation costs (just pay a guy to rip it all up and cart it) 25-Jul-19 09:55 AM the south west corner has a bad spot where water likes to congregate, and the sheathing is super close (there was rot there before) 25-Jul-19 10:03 AM Seems like the cheapest option would be to quickly demolish that "patio" and rebuild later 25-Jul-19 10:03 AM Especially if you don't like it 25-Jul-19 10:03 AM well, it comes down to time, and also I will be moving in a year... soooo.... 25-Jul-19 10:03 AM it's all about how I change it for resale 25-Jul-19 10:03 AM Renting a forklift was like $300 or $400 from what I remember (it's been two years) 25-Jul-19 10:04 AM it's cheaper to simply buy sand and some thick board to lay ontop to move things when I do move, then cleanup the sand 25-Jul-19 10:04 AM Seems like someone could rebuild that for $1000 or so 25-Jul-19 10:04 AM depends on cost of living, yeah? 25-Jul-19 10:04 AM it was like $4k to remove a tree from my roof 25-Jul-19 10:04 AM I'm figuring around here, which isn't too much less than your area, I think 25-Jul-19 10:04 AM k 25-Jul-19 10:05 AM Huh i just talked to a tree guy anf he charged $96/hr 25-Jul-19 10:05 AM But to remove trees he would climb them and then cut piece by piece from the top 25-Jul-19 10:05 AM it took 4 dudes the better part of a day to remove it, then a day or two later the chipper came out to remove the chunks 25-Jul-19 10:05 AM (unless falling it was safe) 25-Jul-19 10:06 AM felling? I thought was the spelling? 25-Jul-19 10:06 AM Oh, yeah maybe 25-Jul-19 10:08 AM not sure real differences 25-Jul-19 10:08 AM w00t, last question on homework 25-Jul-19 10:08 AM 12. Define the term “horn clearance”. How is it checked? 25-Jul-19 10:11 AM Have you considered using a "come along" (manual winch)? 25-Jul-19 10:11 AM At least for getting the beast up the grades? 25-Jul-19 10:11 AM I have.. simply do not have one 25-Jul-19 10:11 AM Cheap at harbor freight 25-Jul-19 10:11 AM Maybe $30 25-Jul-19 10:11 AM hrrmm 25-Jul-19 10:12 AM You'd probably need some chain too, in case the cable it comes with is too short 25-Jul-19 10:12 AM ratcheting straps were one idea 25-Jul-19 10:12 AM I doubt you'd get enough leverage on a ratchet strap 25-Jul-19 10:12 AM I feel like I've had those ratchets twist/buckle on me, but i can't specifically remember 25-Jul-19 10:15 AM if you end up having to just tarp it, make sure you spray it down liberally with something like fluid film. that should protect it from rusting much even with the humidity/weather up there. 25-Jul-19 10:15 AM I have some hydraulic oils and whatnot 25-Jul-19 10:15 AM gear oils 25-Jul-19 10:19 AM Jack hammer or sledge will take care of that ledge in a few minutes 25-Jul-19 10:20 AM thanks for that advice 25-Jul-19 10:21 AM Is the patio big enough to make the turn? ( Assuming you'd come up the driveway first, to the side entrance) 25-Jul-19 10:22 AM turn? 25-Jul-19 10:22 AM to spin the machine? just barely 25-Jul-19 10:22 AM and yeah, I really hope to come from the garage side, actually 25-Jul-19 10:23 AM Yeah, if you come up the driveway then make a right into the patio, then parallel to the house, then a left into the door 25-Jul-19 10:24 AM one issue is that the room above the garage.. where I am sitting right now, is an overhang/cantilever (oriel window) so there isnt really height there immedietly 25-Jul-19 10:24 AM oh, also, there is afirehydrant nearby 25-Jul-19 10:24 AM basically right at the corner of the driveway 25-Jul-19 10:24 AM north end 25-Jul-19 10:24 AM so, not much space for a car to actually pivot around there 25-Jul-19 10:24 AM back up to the patio? sure, but not really meanuever 25-Jul-19 10:26 AM if you dont have a can of fluid film...i think it is worth getting if you plan to be getting any more machines. its really hard to get a nice coating of oil up in all the nooks and crannies vs. spraying it down with an aerosol can of fluid film. 25-Jul-19 10:26 AM just my opinion tho 25-Jul-19 10:26 AM yeah, I'll look into it 25-Jul-19 10:26 AM I do have spray bottles.. 25-Jul-19 10:26 AM i had a lathe i kept outside for a few months in coastal southern california that i sprayed down with it every week and when i finally got it inside there wasnt any new rust 25-Jul-19 10:26 AM good to know 25-Jul-19 10:27 AM since then ive been pretty sold on it haha 25-Jul-19 10:27 AM (please dont keep machines outside ) 25-Jul-19 10:27 AM wasnt my first choice thats for sure but it was up at my uncle's place 25-Jul-19 10:30 AM @Noxz are you trying to get this upstairs?? 25-Jul-19 10:31 AM there are 5 concrete steps outside.. but no 25-Jul-19 10:31 AM Ok, just wondered since you mentioned height 25-Jul-19 10:31 AM slab level, just the slab is not level with the sidewalk 25-Jul-19 10:31 AM repost 25-Jul-19 10:31 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0468-6A9E6.jpg 25-Jul-19 10:31 AM the driveway is decent enough landing spot 25-Jul-19 10:31 AM also, I hope y'all learn from me - and to plan the whole delivery dealio first 25-Jul-19 10:32 AM uh, its going to tip off the pallet if you drop it there... 25-Jul-19 10:32 AM I'd think anyway 25-Jul-19 10:32 AM there is actually a flatter spot near the top 25-Jul-19 10:32 AM about where that red moss is 25-Jul-19 10:32 AM not entirely level, but yeah 25-Jul-19 10:32 AM but not in frame, tothe bottom left corner, is a hydrant 25-Jul-19 10:36 AM Oh man, and you have exposed plywood? 25-Jul-19 10:37 AM no? 25-Jul-19 10:37 AM thats concrete I think your seeing 25-Jul-19 10:37 AM Above the doorway? 25-Jul-19 10:37 AM the blue stuff is self-adheared house wrap 25-Jul-19 10:37 AM the gray stuff is exterior insullation, Roxul comfortboard 80 25-Jul-19 10:37 AM it's basically expanded rock 25-Jul-19 10:37 AM Hmm, looks brown to me 25-Jul-19 10:37 AM I dont yet have siding 25-Jul-19 10:37 AM I will be removing the trim that still remains, and a new door eventually 25-Jul-19 10:37 AM french doors suck 25-Jul-19 10:37 AM at least those do 25-Jul-19 10:37 AM but hey - I got 6ft to play with! 25-Jul-19 11:23 AM Just replaced my siding this spring. Man that was a big bill. 25-Jul-19 11:44 AM what kind? I am going with Allura concrete lap, but with an air gap, on a rainscreen 25-Jul-19 11:44 AM thinking like 5.5" width? I have some 1x3 windows that I want to allign with 25-Jul-19 11:44 AM 3x1? 25-Jul-19 11:44 AM also, no call yet - and no truck (justfinished a small afternoon dog walk) 25-Jul-19 11:44 AM was hot at top of hill, sitll 70 in the house, once it hits 71 I'll switch on the one small portbale AC I have 25-Jul-19 11:44 AM 66 in the bedroom that gets near no sun 25-Jul-19 11:44 AM also - half thought of building an extension /"floor" support for the hoist front feet that hang off.. I have plenty to make it work.. one single 2x4 is rated at like 500lbs, vertically.. 3+ of them on each side and I should be decent (basically small cripples/studs, and a double+top plate, with some diagonal bracing) 25-Jul-19 11:44 AM not sure how crazy the idea really is 25-Jul-19 11:44 AM this would be done between stairs + rose 25-Jul-19 11:44 AM then roll the hoist back onto the patio with machine lifted.. I am sure that 4" space for the wheels is not enough.. maybe block them in, ie, little railings 25-Jul-19 11:44 AM just ideas based on having a bit of lumber on hand 25-Jul-19 11:44 AM I really dont want to do much with it coming soon though, as the front of the hous eis west facing and is about to get hit with sun 25-Jul-19 11:44 AM shaved head - and no sunscreen (I should really get some...) 25-Jul-19 11:44 AM hats work, but then arms 25-Jul-19 11:44 AM ramble ramble 25-Jul-19 11:57 AM Get a hat with a string to tie it on? 25-Jul-19 11:57 AM what purpose is t his string? 25-Jul-19 11:57 AM So it doesn't fall off 25-Jul-19 11:57 AM that isnt the problem 25-Jul-19 11:57 AM Idk why you mentioned 'arms' 25-Jul-19 11:57 AM the problem is - even if I cover my head - my arms are exposed 25-Jul-19 11:58 AM Oh, long sleeve shirt 25-Jul-19 11:58 AM but, my head will get hit first.. I have like 20 hats 25-Jul-19 11:58 AM long sleves in 80 F... meh 25-Jul-19 11:58 AM How long do you plan on being out there?? 25-Jul-19 11:58 AM as long as it takes? 25-Jul-19 11:58 AM sun kinda gets blocked around 7:30pm 25-Jul-19 11:58 AM I mean, an hour or so seems OK as for vitamin D production 25-Jul-19 11:58 AM hah, I have spent that long out there already (dog walks) 25-Jul-19 11:59 AM Also, it isn't even noon yet 25-Jul-19 11:59 AM I am pretty active outside, not sure why I am complaining 25-Jul-19 11:59 AM How are you having afternoon walks?!?! 25-Jul-19 11:59 AM and I used to live in cali, so meh 25-Jul-19 11:59 AM it just turned 12pm here 25-Jul-19 11:59 AM which is the typical time I get here from school during lunch break 25-Jul-19 11:59 AM My phone says 11:59 25-Jul-19 11:59 AM Ah 25-Jul-19 11:59 AM but, since I was here already, I decided on an earlier walk 25-Jul-19 11:59 AM I guess it is not an AFTERnoon walk 25-Jul-19 11:59 AM but a NEARLYnoon one 25-Jul-19 11:59 AM or noon walk 25-Jul-19 11:59 AM but that doesnt sound good 25-Jul-19 11:59 AM sounds like moon walk 25-Jul-19 12:00 PM Getting hot here too 25-Jul-19 12:00 PM 78 f my phone says 25-Jul-19 12:00 PM my house doesnt start to get hot till 2+ 25-Jul-19 12:00 PM I live under a bunch of huge trees 25-Jul-19 12:00 PM So i usually do pretty well 25-Jul-19 12:01 PM I have quite a few trees too 25-Jul-19 12:01 PM but also half underground 25-Jul-19 12:01 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20190725_120125-44AF0.jpg 25-Jul-19 12:01 PM do I have a shot of mine... 25-Jul-19 12:01 PM flat rooftop 25-Jul-19 12:01 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0429-F2344.jpg 25-Jul-19 12:01 PM doesnt show it well, not really 25-Jul-19 12:01 PM but trees kinda all around 25-Jul-19 12:02 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20190725_120212-9ABD0.jpg 25-Jul-19 12:02 PM douglas firs and broad leaf mapples 25-Jul-19 12:02 PM Is that from your roof? 25-Jul-19 12:02 PM yes 25-Jul-19 12:02 PM on the flat section 25-Jul-19 12:02 PM gable end 25-Jul-19 12:02 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0426-AA55A.jpg 25-Jul-19 12:02 PM ooposite end 25-Jul-19 12:02 PM you can kinda see how close the trees are.. 25-Jul-19 12:02 PM heh 25-Jul-19 12:03 PM Mmm 25-Jul-19 12:03 PM it was a long shot 25-Jul-19 12:03 PM okay, yeah, this was right after ripping off the front stairs which went to the upper "unit" (not officially a duplex, but kinda was..) 25-Jul-19 12:03 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20181020_131138-C83DC.jpg 25-Jul-19 12:03 PM trees 25-Jul-19 12:03 PM also, fire hydrant, and retaining wall 25-Jul-19 12:03 PM the trees are like 50+ft tall 25-Jul-19 12:03 PM there is a creek that sepaarates me from next dude (a 40ft drop!) 25-Jul-19 12:03 PM oh, and streets 25-Jul-19 12:17 PM Nice 25-Jul-19 12:22 PM I guess the hydrant is further away than how I imagined it.. but still need to know it is there 25-Jul-19 12:28 PM That machine is a mill? 25-Jul-19 12:28 PM universal tool & cutter grinder 25-Jul-19 12:28 PM I more or less have a mill already 25-Jul-19 12:28 PM and a lathe 25-Jul-19 12:28 PM and a surface plate.. but that may be the limit of my machinig tools? 25-Jul-19 12:28 PM in ohio I have a old swiss jig borer+accesories, and a pantograph-mill 25-Jul-19 12:28 PM (3d) 25-Jul-19 12:28 PM oh, I guess I have some watchmaking specific stuff too 25-Jul-19 12:28 PM a bit of that 25-Jul-19 12:28 PM lifting slings + shackles are out for delivery.. 25-Jul-19 01:42 PM are now in hand.. 25-Jul-19 01:42 PM btw, a 2"x6' and 2"x8'.. rated at 12800 basket, or 5100 choker.. so plenty of power in them 25-Jul-19 02:46 PM no appointment date being shown on the freights online tracker... but it took several days to even get posted, so timely manner stuff isnt high up there.. the est delivery date is still today 25-Jul-19 02:46 PM no call yet 25-Jul-19 03:01 PM I'm on the edge of my seat! 25-Jul-19 03:03 PM hah, I am settling down, finally 25-Jul-19 03:03 PM kinda wish it doesnt happen soon, as it is hot 25-Jul-19 03:03 PM may even be up for a reschedule - maybe when I know I have more help 25-Jul-19 04:31 PM .. 25-Jul-19 04:31 PM I guess I will call customer service tomorrow morning 25-Jul-19 04:31 PM figure out the if/when 25-Jul-19 05:51 PM hah, had a false alarm, a truck backed up my steep driveway, simply to turn around 25-Jul-19 05:51 PM facepalms 25-Jul-19 09:38 PM :( 26-Jul-19 04:52 AM Joined the server. 26-Jul-19 12:03 PM no news is good news? 26-Jul-19 12:24 PM You still haven't heard from them? 26-Jul-19 12:24 PM Should probably call to make sure they did not screw something up... 26-Jul-19 01:03 PM nothing yet, I think what it is - is that it was transported, but it still needs to be delivered, and they are backlogged in that area 26-Jul-19 01:03 PM dont know if they are open tomorrow to call though, so maybe giving customer service a ring will give me more info 26-Jul-19 01:03 PM I sort of want a few more days to prep.. so I would preffer to not contact them till Monday if I can help it.. 26-Jul-19 08:47 PM Finally got my laminar flow bench through the door. Now to reassemble.... 26-Jul-19 08:47 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_2108-3DFA3.JPG 26-Jul-19 09:12 PM Is that a jun air? 26-Jul-19 09:32 PM Silentaire, same as a Jun Air I think 26-Jul-19 09:58 PM Those things are so nice 26-Jul-19 11:10 PM neat neat 26-Jul-19 11:10 PM I'm into a little bit of mycology (blue oysters and enokitakes on agar) and have wanted a laminar for a while.. just been doing glove/still boxes 27-Jul-19 12:33 AM mycology stuff is fun...Southern California makes it hard though. only get to find fungi out in the wild about 3months a year if you are lucky. 27-Jul-19 12:33 AM @piGuy what are your plans with the laminar flow bench? 27-Jul-19 09:43 AM Nice flow hood! 27-Jul-19 09:43 AM If I lived alone, I'd probably have one in my livingroom too 27-Jul-19 10:58 AM I bought it on eBay for only $250 with a brand new HEPA filter in it. I think the owner was using it for a nursery, something to do with orchids. I'm going to use it for medical diagnostic device development (doing contract work for a university developing a device for HIV testing) 27-Jul-19 10:58 AM @AdamMcCombs , the air compressor I got is a bit of lemon. It lived a hard life doing spray tanning before I bought it. Check valves keep sticking and getting clogged with debris. 27-Jul-19 11:06 AM very cool. 27-Jul-19 11:06 AM i wonder what field has more flow hoods... orchid propagation or mycology 27-Jul-19 11:06 AM ive got a big hepa filter that i am keeping around to eventually build a flow hood with, was a great deal like $50 after they shut down San Onofre's nuclear generating station 27-Jul-19 11:34 AM well biotech in general covers orchids or fungi.... but any cell culture benefits from a flow hood 27-Jul-19 01:03 PM I assume you've all seen this by now: https://hackaday.com/2019/07/26/the-march-toward-a-diy-metal-3d-printer/ 27-Jul-19 01:11 PM I've seen it before. Definitely interesting, but not much on the gun design. Current is more important than voltage for ebeam welding, it seems like they are going a more SEM gun approach, which I have some reservations about for this application. 60kv, but chances are current will be in the uA range. 27-Jul-19 01:11 PM Ebeam welders usually much lower voltage but much higher current. 27-Jul-19 01:11 PM I think a better approach would be using a hollow plasma cathode source which has current density capabilities up to 10^4 A/cm2 and can operate at pressures as high as in the millitorr range. 27-Jul-19 01:11 PM Completely eliminates the need for a filament supply and high voltage isolation transformer. Also significantly longer lifetimes, not to mention massive current handling for serious ebeam welding 27-Jul-19 01:23 PM How do you go from a hollow plasma cathode source to getting an ebeam from it? 27-Jul-19 01:23 PM I've read a bit about them, but only in context of activating chemistry for deposition 27-Jul-19 01:23 PM So if anything, I'd think you'd get an ion beam if you had some extractor and lensing 27-Jul-19 01:25 PM Plasma has infinite work function, making electron extraction at huge currents very easy. Has to be set up properly to prevent ion emission 27-Jul-19 01:25 PM But if you want real ebeam currents, plasma cathodes are the way to go 27-Jul-19 01:25 PM Thermionic is pitifully weak in comparison 27-Jul-19 01:26 PM Lower kV means fatter beamspot tho right? 27-Jul-19 01:26 PM At least for acceleration? 27-Jul-19 01:26 PM Depends on the source 27-Jul-19 01:26 PM Generally beam spot is larger, but you can focus it down after the emission source 27-Jul-19 01:26 PM Thermionic emission is still far more used, but you need more than a hairpin filament for ebeam welding 27-Jul-19 01:26 PM Actually plasma cathode is probably overkill lol 27-Jul-19 01:26 PM Just want a more beefy filament 27-Jul-19 01:26 PM Well, depending on weld depth you would want higher potential. Up to a couple hundred kv can be used for deep penetration welds 27-Jul-19 01:26 PM Still usually need an average power of kWs though 27-Jul-19 01:34 PM Hmm 27-Jul-19 01:36 PM So 60kV is definitely in the right range, but I don't think uAs will cut it at all 27-Jul-19 01:36 PM Unless they plan on going with a much higher current source, but from the limited info it looks more like a sem setup 27-Jul-19 01:36 PM For the general 60-200kV typically used at higher DC currents, xrays will be nasty lol 27-Jul-19 01:36 PM For 3d printing based deposition and sintering, penetration depth can be far less than typical industrial ebeam welding, which is why I think it would be better to go with a low voltage, high current hollow cathode source in this case. It would probably be cheaper and safer 27-Jul-19 01:36 PM Or using a very beefy, larger filament 27-Jul-19 01:36 PM However, your gun has to be designed so that it can also extract the required beam current. Even if your supply and source can provide it, you still need to extract the beam 27-Jul-19 01:45 PM Is a hollow cathode anything special, or literally just a piece of pipe with a wire connected at one end? 27-Jul-19 01:45 PM (or the middle) 27-Jul-19 01:48 PM It's kind of like that, but a bit more complicated. General there is a hollow cathode and anode seperate by an insulator, but they can also require a keep alive for ionization and a gas supply depending on application. Also usually magnetic fields are necessary 27-Jul-19 01:48 PM I'll get some diagrams one sec 27-Jul-19 01:48 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Hollow_Plasma_Cathode_Source_-_200kV_1kA-8D00C.jpg 27-Jul-19 01:48 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Hollow_Plasma_Cathode_Source_Example-F79C6.jpg 27-Jul-19 01:48 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Foreline_Pressure_Hollow_Plasma_Cathode_So-30463.jpg 27-Jul-19 01:48 PM They can operate anywhere from like 1kV to several hundreds of kV at kAs of current, anywhere from ns pulses to DC, and up to pretty high foreline pressures 27-Jul-19 01:48 PM you can also make a vacuum arc extraction source: 27-Jul-19 01:55 PM Yeah i remember reading about high pressure elsewhere 27-Jul-19 01:56 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Hollow_Cathode_Vacuum_Arc_Source_Diagram-C0A11.jpg 27-Jul-19 01:56 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Hollow_Cathode_Vacuum_Arc_Source_Operation-C7A82.jpg 27-Jul-19 01:56 PM I'm sure by now you can see that I'm not a fan of thermionic emission guns. Too boring and weak, costs more than what you get from them lol 27-Jul-19 01:56 PM though I guess they are necessary for UHV processes still lol 27-Jul-19 02:02 PM Hmm, the diagrams make me want to try my sputter coater build this way 27-Jul-19 02:03 PM Now, a dc gun at amps of current at 10s of kv would be an absurdly costly supply. Not practical for the amateur. However, you just build a simple thyratron pulser to drive one of these at 10s to 100s of hz, and you easily have a cheap supply capable of amps of current at 10s of kV. Perfect for diy vacuum sintering and welding. 27-Jul-19 02:05 PM Did you get those diagrams from the same book? 27-Jul-19 02:05 PM Or are they collected from various places? 27-Jul-19 02:06 PM Want to do deposition with it? No problem either: 27-Jul-19 02:06 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Enhanced_Hollow_Cathode_Plasma_Source_for_-6340F.pdf 27-Jul-19 02:06 PM Diagrams are from verious places. Like I've said, I have collected and read a lot of papers over the years lol 27-Jul-19 02:07 PM Awesome 27-Jul-19 02:07 PM Thanks! 27-Jul-19 02:07 PM I really need to bite the bullet and pay someone to build a garage extension for me 27-Jul-19 02:07 PM I need more space 27-Jul-19 02:08 PM No problem lol, gotta get more people introduced to the potential of more unique beam sources. A lot more can be done at home if more people knew this stuff existed 27-Jul-19 02:08 PM (or just move somewhere with a huge shop) 27-Jul-19 02:08 PM The place I learned about hollow cathode plasma sources was from a linkedin group I'm in about atomic layer deposition, from this company meaglow.com 27-Jul-19 02:08 PM Www.meaglow.com 27-Jul-19 02:08 PM Well i guess links don't post here without some special formatting or the http prefix 27-Jul-19 02:10 PM I'm sure their stuff costs an arm and a leg. But sources like this could be built super cheap, and are very versatile. I think it would be easier than a filament based gun, and would get you more bang for your buck 27-Jul-19 02:12 PM Nice 27-Jul-19 02:12 PM Have you heard of Oregon Physics? 27-Jul-19 02:12 PM Nope 27-Jul-19 02:12 PM http://www.oregon-physics.com/ 27-Jul-19 02:12 PM They make ion and e beam optics and sources 27-Jul-19 02:12 PM I visited them once 27-Jul-19 02:12 PM Maybe I should try befriending them 27-Jul-19 02:12 PM Get some mentorship or something 27-Jul-19 02:13 PM Never hurts to make connections in the industry! 27-Jul-19 02:22 PM Also, I think I misspoke earlier. Plasmas have zero work function, not infinite lol 27-Jul-19 02:22 PM Quite a difference between the two 27-Jul-19 02:45 PM Yeah i was reading and thinking you might have meant infinitely small 27-Jul-19 03:20 PM my other freighted machine on same carrier is on it's way to this state (small in comparison, 200lbs).. I wonder if they will simply deliver both together, I would 27-Jul-19 03:22 PM Haha might make your life harder that day 27-Jul-19 03:22 PM But at least concentrate the pain into a single workout session 27-Jul-19 03:31 PM this other machine should be simple though.. like really no lift gate needed for it 27-Jul-19 03:31 PM I think it is less than 200#, that is simply a safe estimate 27-Jul-19 03:31 PM but yeah, when they went to pick it up a week ago there as no paper work, so the truck turned back around and went hime 27-Jul-19 03:31 PM had to call customer service and sort out what was needed 27-Jul-19 03:31 PM of course I wasnt there, as I am the destination, so trying to figure it all out was meh 27-Jul-19 03:31 PM deciding if I want to rig something up and do it now, or order a boring head for the mill which I need anyways (imported one until I can make my own) 29-Jul-19 04:55 PM my other item has arrived at the same depot.. 30-Jul-19 01:40 AM @Applied_Ion so I see some hollow cathode light bulbs... I guess there's some "simpler" applications of this idea, might mean I can find some decent intro material (i.e. YouTube stuff or slideshows) 30-Jul-19 01:40 AM Seems the lightbulbs might even be useful for scavenging electrodes from? 30-Jul-19 01:11 PM Just got a call for shipment of this second machine.. But, apparently the large one got misplaced in Chicago! 30-Jul-19 01:11 PM Even though tracking said it was in WA 30-Jul-19 01:11 PM They know where it is though.. 30-Jul-19 01:14 PM @nmz787 maybe? Idk, looking at them, they are a bit different, though maybe similar in principle, but not really for generating beams. For a hollow cathode ebeam source, you can just use like copper tubing probably, doesn't have to be any exotic metal 30-Jul-19 01:23 PM @AdamMcCombs how many X zoom can a psem get to? 30-Jul-19 01:23 PM I.e desktop unit 30-Jul-19 02:12 PM @Applied_Ion oh, ok,makes it easier then, at least for a first-pass attempt 30-Jul-19 04:17 PM @nmz787 I'm not sure but it's definitely less than what a SEM can theroreticaly do 30-Jul-19 04:18 PM But definitely more than an optical microscope, Right? 30-Jul-19 04:18 PM I'm realizing there is two psems I'm thinking of 30-Jul-19 04:18 PM What's the exact model? 30-Jul-19 04:19 PM Just thinking about driving around with a better-than-optical scope in my car, etc... 30-Jul-19 04:19 PM Nothing specific 30-Jul-19 04:33 PM Oh the little tiny tiny one? 30-Jul-19 04:33 PM Like looks like it could be an optical scope? 30-Jul-19 04:44 PM adam, any days available in the nearish future? I dont expect the big machine to arrive/be ready for delivery before friday 30-Jul-19 04:44 PM but yeah, it's still in Chicago 30-Jul-19 04:44 PM also - gives plenty of time to figure stuff out 30-Jul-19 04:44 PM and they seem pretty open on delivery dates.. re the smaller one they called about today, they basically said: tomorrow? thursday? friday?... 30-Jul-19 04:44 PM fridays are my half days - so I picked that 30-Jul-19 07:39 PM I'm prepping for a conference in Portland next week... 30-Jul-19 07:40 PM k, no worries, will figure it out 30-Jul-19 07:40 PM thanks for all the info thus far 30-Jul-19 07:40 PM will probably give y'all a play-by-play 31-Jul-19 01:57 PM https://upload.wikimedia.org/wikipedia/commons/5/5f/2mv_accelerator-MJC01.jpg I just found this picture on wiki, it has the description "A 1960s single stage 2 MeV linear Van de Graaff accelerator, here opened for maintenance" 31-Jul-19 01:57 PM and I just love the garage hacker feeling it gives off 01-Aug-19 07:27 AM Looks like a movie prop! Gotta love big chunky 60’s components. 01-Aug-19 07:27 AM Although doorknob caps and stuff have not really changed that much. 01-Aug-19 08:38 AM I lost the game 01-Aug-19 04:53 PM @Noxz , any update on your equipment? 01-Aug-19 04:54 PM I am getting my small grinder tomorrow.. the large one I got a small update on tuesday saying it stayed behind in chicago for some ungodly reason 01-Aug-19 04:54 PM so, it still needs to work it's way to WA 01-Aug-19 04:54 PM which means more time to also figure out a crane type of thing 01-Aug-19 04:54 PM maybe a winch/come along wouldn't be a terrible idea 01-Aug-19 04:54 PM 2 weeks untill summer quarter ends - then I have a month off 02-Aug-19 10:25 AM Joined the server. 02-Aug-19 10:34 AM ...... my small freight delivery today was pushed back, didnt get unloaded yet 02-Aug-19 10:34 AM doh 02-Aug-19 10:34 AM it was scheduled, but is way back in the trailer or something 02-Aug-19 10:34 AM even if they find it, they will not get it out today, so, next week it is 02-Aug-19 10:34 AM means I also do not have to chill around for it 02-Aug-19 10:35 AM Whoa, this server has a bunch of people I recognize! 02-Aug-19 10:35 AM This is very nifty, glad I was invited by @ali_as 02-Aug-19 10:37 AM I actually don't think anyone here knows me, I joined a few days ago. I recognise some people from twitter. 02-Aug-19 10:37 AM Yeah that's where I see people from 02-Aug-19 10:38 AM But this is so your kind of place. 02-Aug-19 10:38 AM Absolutely my kind of place 02-Aug-19 10:38 AM my DIY SEM project is perhaps a bit too ambitious, but if I get this high vac system running, won't hurt to try 02-Aug-19 11:18 AM DIY SEM is also in my future 02-Aug-19 11:18 AM planning on my electron source to be from the photoelectric effect, ie, shine a laser on a photodiode and it'll create a 'mass' of electrons that fly off.. vs some old heated tungsten wire 02-Aug-19 11:18 AM allows you to turn it ON/OFF pretty quick, for things like e-beam lithography 02-Aug-19 11:29 AM I doubt you'd get much current that way 02-Aug-19 11:30 AM it's used on a large scale at SLAC 02-Aug-19 11:30 AM As for beam blanking, you can just shove them off to the side with a magnet or an unbalanced electrostatic deflection plate 02-Aug-19 11:30 AM many people have told me that 02-Aug-19 11:30 AM you just have to do that before it gets focused 02-Aug-19 11:30 AM so after the wehnelt, but before beam forming 02-Aug-19 11:32 AM My favorite microscopes are photo electric 02-Aug-19 11:32 AM oh? 02-Aug-19 11:32 AM I wasnt aware that microscopes do it 02-Aug-19 11:32 AM Also the amount of probe current is insanity 02-Aug-19 11:32 AM very few references I have come across 02-Aug-19 11:32 AM Hm 02-Aug-19 11:32 AM I was thinking about the probe current in a practical way 02-Aug-19 11:32 AM Enough to shove off a quantifiably detectable amount of secondaries 02-Aug-19 11:33 AM Oh yeah 02-Aug-19 11:33 AM way more than enough 02-Aug-19 11:33 AM On that topic - I still wonder whether regular scintillators would be fine for DIYing an everhart-thornley detector, or if a YAP/YAP:Ce scint is required 02-Aug-19 11:34 AM Regular p47 is fine 02-Aug-19 11:34 AM I can very easily detect both tiny and huge amounts of beta from a Sr-90 source with a generic CsI:Tl crystal 02-Aug-19 11:34 AM Though it is a very angry Sr-90 source 02-Aug-19 11:34 AM But then again, photon packet counting is different from running the PMT in current mode 02-Aug-19 11:35 AM https://phys.org/news/2017-02-combining-pulsed-laser-electron-gun.amp 02-Aug-19 11:35 AM femtosecond pulses 02-Aug-19 11:35 AM that would be really hard 02-Aug-19 11:35 AM nanosecond UV too 02-Aug-19 11:35 AM Yeah you don't need that 02-Aug-19 11:35 AM those lasers alone would cost as much as a very nice field emission SEM :P 02-Aug-19 11:36 AM The fempto pulse is to image ultra short time scale events 02-Aug-19 11:36 AM if a CW laser can be used, that should be very possible 02-Aug-19 11:37 AM I need to see if something else is public give me a sec 02-Aug-19 11:38 AM not sure what advantage it would give for a DIY SEM though 02-Aug-19 11:38 AM given you can get electron guns of all shapes and sizes from scrap gear 02-Aug-19 11:38 AM it's more so: havent seen it done and sounds cool 02-Aug-19 11:38 AM it'd be difficult to get a regular DIY SEM working, let alone photocathode 02-Aug-19 11:38 AM but it's a worthy upgrade later 02-Aug-19 11:38 AM I'm thinking of modifying a soviet oscilloscope gun to drop the focus, since they're physically large and easy to work on 02-Aug-19 11:42 AM about time for a dog walk, bbl 02-Aug-19 11:45 AM So I can say photo electric SEM column is a thing, but wasn't actually used as a sem 02-Aug-19 11:45 AM Totally works though 02-Aug-19 11:46 AM I'll be getting a quartz window in my vacuum chamber 02-Aug-19 11:46 AM So I'll try making a photoelectric electron source 02-Aug-19 11:47 AM You can do it off regular filaments/other sources as well 02-Aug-19 11:47 AM from what I can see in papers, it mostly concerns nanosecond pulses with field emission off needles 02-Aug-19 11:47 AM but everything mentions that it's "super bright" 02-Aug-19 11:48 AM Yeah that's the highest performance 02-Aug-19 11:48 AM Which if you are going to spend the money to do it right you might as well really do it right 02-Aug-19 11:49 AM Field emission requires vacuums I probably won't achieve though 02-Aug-19 11:49 AM I'll be happy if after cleaning and baking I get to -6 02-Aug-19 11:49 AM No point in going field if you are just doing a diy column 02-Aug-19 11:49 AM My only goal for a DIY SEM is to image further than optical can resolve 02-Aug-19 11:49 AM So around 150-180nm feature sizes 02-Aug-19 11:49 AM Which I think I could do 02-Aug-19 11:50 AM You are definitely going to be resolution limited by your aberation and not gun 02-Aug-19 11:50 AM But all I have right now is a forepump, a turbopump, and two gauges(pirani and ion to cover the entire range), so nothing is set in stone yet 02-Aug-19 11:50 AM Vacuum gear is expensive :s 02-Aug-19 11:54 AM Eugh I am going to have to keep an eye out at my surplus store for a good thick aluminum plate for the base of a bell-jar... 02-Aug-19 11:55 AM Might be cheap to just buy one 02-Aug-19 11:55 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-03BD4.png 02-Aug-19 11:55 AM Aluminium isn't that expensive 02-Aug-19 11:55 AM Erm 02-Aug-19 11:55 AM not really 02-Aug-19 11:55 AM Yikes, that is off the charts 02-Aug-19 11:55 AM when you get above 1/2" 02-Aug-19 11:55 AM its just unreasonably expensive 02-Aug-19 11:56 AM Here's a thought - you don't need more than 1/2" for vacuum tightness 02-Aug-19 11:56 AM for a hack together evap coater 02-Aug-19 11:56 AM But you could reinforce it 02-Aug-19 11:56 AM well its more for feedthroughs... 02-Aug-19 11:56 AM That should still be just about fine for feedthroughs 02-Aug-19 11:56 AM Especially if you add a bit of reinforcement 02-Aug-19 11:57 AM if your using off the shelf feedthroughs attached to the plate, sure, if your going to build them into the plate, not so much 02-Aug-19 11:57 AM you'd be pressed for space 02-Aug-19 11:57 AM Do you have a lathe? 02-Aug-19 11:57 AM I don't know if I know anyone with a lathe big enough to handle a piece of stock that large 02-Aug-19 11:57 AM Nono, you'd turn the feedthrough 02-Aug-19 11:57 AM but I have access to lathes through various people, grandfather, friends, etc 02-Aug-19 11:57 AM Fine threads would work fine in about 10mm of alu 02-Aug-19 11:58 AM I am talking more mechanical feedthrough 02-Aug-19 11:58 AM Get the largest tap you can and turn the feedthrough 02-Aug-19 11:58 AM which requires a seal or two and bearings 02-Aug-19 11:58 AM Look at how Ben Krasnow did his for an evap coater 02-Aug-19 11:58 AM He got those fancy seals from McMaster 02-Aug-19 11:58 AM Thats what I'm referencing 02-Aug-19 11:58 AM I believe he used 3/4in 02-Aug-19 11:58 AM those aren't fancy, fairly common shaft seals 02-Aug-19 11:58 AM One thing you could do is TIG weld some bar stock on to thicken the feedthrough area 02-Aug-19 11:58 AM I had to replace them in a roughing pump I have for my SEM 02-Aug-19 11:58 AM you only ever want to weld from the inside edge for vacuum applications otherwise you get virtual leaks 02-Aug-19 11:58 AM which you can't do if butt-welding two plates together 02-Aug-19 11:59 AM You won't get virtual leaks if you use no filler and weld solid bar stock with no holes 02-Aug-19 11:59 AM And then drill it out 02-Aug-19 11:59 AM you could probably just bolt on a thicker piece if you just need another bearing for example 02-Aug-19 12:00 PM You could also do that 02-Aug-19 12:00 PM Thread in a larger piece with a larger thread 02-Aug-19 12:00 PM Sort of as a thread-in mechanical feedthrough, all pre-assembled 02-Aug-19 12:00 PM I mean this isn't a rush project 02-Aug-19 12:00 PM I could also just wait for some stock to appear at the surplus place 02-Aug-19 12:00 PM The bigger part of the equation is finding a good bell jar 02-Aug-19 12:00 PM https://www.ebay.com/itm/Glass-Vacuum-Bottom-Draw-Bell-Jar-18-inch-wide-12-inch-tall/254318353182 02-Aug-19 12:01 PM Oh, yeah. Bell jars suck, I've given up on finding one a while ago 02-Aug-19 12:01 PM Something like this looks nice, and would give me plenty of room for a small evap 02-Aug-19 12:01 PM This is why I'm probably going with an ISO160 tee chamber 02-Aug-19 12:01 PM Yea, I'd just build it into conflat or something but you can only get so large before it just becomes so stupid expensive. 02-Aug-19 12:02 PM But I also have the issue of shipping a fragile chunk of glass across the world 02-Aug-19 12:02 PM I actually have some conflat 8 or 10" endcaps with mechanical and massive electrical feedthroughs already 02-Aug-19 12:02 PM But I'd be mostly concerned with getting in and out of the chamber and cleaning of that chamber every now and then 02-Aug-19 12:02 PM it would become a pain... bell jar is nice and accessable and I think why most commerical coaters that aren't the size of the room they get installed in are just bell jars 02-Aug-19 12:02 PM like I have seen two styles of evap coaters 02-Aug-19 12:02 PM bell jar, little cart things 02-Aug-19 12:02 PM and ones big enough to climb inside for cleaning 02-Aug-19 12:02 PM like seriously, they open the massive door, put scaffolding in, and climb in to clean it. 02-Aug-19 12:02 PM The cryo pumps for those things have openings large enough for someone to climb in through 02-Aug-19 12:04 PM And cryocompressors enough to chill a building, I bet 02-Aug-19 12:05 PM probably, though I have enough to cool my house at this point... 02-Aug-19 12:05 PM Somehow have 3 compressors in my basement now, two of which I can't even run because 3 phase 02-Aug-19 12:05 PM I was super lucky to find some hoses for them at the surplus place, but they are in rough shape... I dunno if you can "rebuild" those hoses since they do have rubber?viton?something bits in the ends of them 02-Aug-19 12:06 PM the hoses themselves are probably just fancy rubber 02-Aug-19 12:06 PM since they don't get cold 02-Aug-19 12:06 PM well, they don't get that cold 02-Aug-19 12:14 PM @Conmega how about this pricing? 02-Aug-19 12:14 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_20190802-121240-A369B.png 02-Aug-19 12:14 PM 77$ for 2x2 02-Aug-19 12:18 PM thats 1x1 and half inch? 02-Aug-19 12:18 PM Yeah 02-Aug-19 12:18 PM oh I see you calculated more 02-Aug-19 12:18 PM thats way more reasonable, a place local to you? 02-Aug-19 12:19 PM No 02-Aug-19 12:19 PM But that's probably what I could get it for here as well 02-Aug-19 12:19 PM Aluminum should be pretty darn cheap 02-Aug-19 12:19 PM 120 bucks for 2x2ft 3/4 not bad 02-Aug-19 12:19 PM ok yea I'll just order from this place, also nice being able to specify by the inch and not the foot 02-Aug-19 12:19 PM so if I only get a 16" belljar I can get like an 18x18 base or something 02-Aug-19 12:20 PM I would look for something local 02-Aug-19 12:20 PM Also a taller jar is nice for coating 02-Aug-19 12:21 PM I've noticed they go for taller jars normally, any particular reason? 02-Aug-19 12:21 PM just for putting the coated piece further for slower coating spead? 02-Aug-19 12:21 PM More uniform 02-Aug-19 12:21 PM ah right that too 02-Aug-19 12:21 PM I'll have to keep an eye out then 02-Aug-19 12:21 PM Also less thermal effect 02-Aug-19 12:21 PM IR in a vacuum... 02-Aug-19 12:22 PM I wish that the place in NJ didn't just go miraculously back into business otherwise I wouldn't be fussing with this. 02-Aug-19 12:22 PM Lol yeah 02-Aug-19 12:22 PM I mean good for em 02-Aug-19 12:22 PM But also 02-Aug-19 12:22 PM yea I suppose at-least they will continue to GET STUFF from the sources they were 02-Aug-19 12:22 PM which if they went out could have just turned to scrapping the stuff outright 02-Aug-19 12:22 PM but yea 02-Aug-19 12:22 PM either way, I am starting to get organized in the basement 02-Aug-19 12:22 PM once I get a shelf emptied off I am going to move all HV stuff to it and maybe poke at the SEM again 02-Aug-19 12:22 PM Get the column out and probably hopefully not destroy apertures 02-Aug-19 12:24 PM You need an apurture flamer 02-Aug-19 12:24 PM or a propane torch apparently >.> 02-Aug-19 12:24 PM with nitrile gloves right? :P 02-Aug-19 12:25 PM Well both 02-Aug-19 12:25 PM I already have a torch for map/propane 02-Aug-19 12:25 PM thats not a problem 02-Aug-19 12:25 PM The flamer is just to hold the apuretures 02-Aug-19 12:25 PM ah I see 02-Aug-19 12:25 PM well you know how to find them on eBay kinda, I don't lol 02-Aug-19 12:25 PM It's platinum so it doesn't contaminate it like steel does 02-Aug-19 12:25 PM ahhh 02-Aug-19 12:25 PM Yeah there's a few up right now 02-Aug-19 12:26 PM Well DM me if your interested in sharing, if not its whatever it can wait 02-Aug-19 12:26 PM I can always start on the other SEM 02-Aug-19 12:26 PM I have one so I haven't been paying very close attention 02-Aug-19 12:27 PM Well then DM me your search terms lol 02-Aug-19 12:27 PM Not like I'm going to buy out the market on flamers, I should only need one I presume 02-Aug-19 12:28 PM I forget do you have a strip apurture in the variable one or is it a bunch of disks? 02-Aug-19 12:29 PM I think its a strip? I'll have to check the docs again, but I believe its strip and like I remember you kind of mentioning I'm SOL if its broken or missing 02-Aug-19 12:29 PM You want a flamer with a hook then 02-Aug-19 12:29 PM Il check my ISI one and see what it is so you don't have to vent 02-Aug-19 12:30 PM do those strip apertures have a hole for hanging them or something? 02-Aug-19 12:31 PM Yeah 02-Aug-19 12:31 PM Something platinum preferably 02-Aug-19 12:31 PM well if I'm cleaning the column I have to vent anyway... 02-Aug-19 12:31 PM Yeah but you don't want to leave it vented ever 02-Aug-19 12:31 PM Always store under vacuum 02-Aug-19 12:31 PM I know 02-Aug-19 12:32 PM I spent way too much time on that damn gun chamber 02-Aug-19 12:32 PM also could you make one out of platinum wire then? not saying platinum wire is cheap but it might be cheaper than the tool 02-Aug-19 12:32 PM heh... yea I know 02-Aug-19 12:32 PM The tool also has a boat for the other apuretures 02-Aug-19 12:32 PM I know 02-Aug-19 12:32 PM could make a "boat" out of the wire too if you just kinda make a mesh out of it 02-Aug-19 12:32 PM would be a royal pain but doable 02-Aug-19 12:33 PM Yeah that might work 02-Aug-19 12:33 PM but the wire probably costs more than a used aperture burner? 02-Aug-19 12:33 PM https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F252944436070 02-Aug-19 12:33 PM This is similar to what I got 02-Aug-19 12:33 PM But way more money 02-Aug-19 12:34 PM yea I saw that one, I also saw they sell new for like 350... so yea thats stupid for used 02-Aug-19 12:35 PM I think i got mine for about 125? 02-Aug-19 12:35 PM thats more reasonable 02-Aug-19 12:36 PM I thought so to, especially for cleaning 500$ strips 02-Aug-19 12:36 PM yeaaaa.... 02-Aug-19 12:37 PM One of those things I should bill for using 02-Aug-19 12:38 PM heh yeaaa 02-Aug-19 12:38 PM But yea I dunno if I need the apertures clean as much as just the column 02-Aug-19 12:38 PM I should add before I got the tool I always just used tweezers and got by 02-Aug-19 12:38 PM I think column contamination is my major issue 02-Aug-19 12:38 PM They need cleaned 02-Aug-19 12:38 PM Apureture contamination is usually what I find 02-Aug-19 12:39 PM Ah ok 02-Aug-19 12:39 PM Yours is going to be both apureture and bulk 02-Aug-19 12:39 PM *likely 02-Aug-19 12:40 PM so how important is the platinum wire for cleaning? just where it TOUCHES or anywhere near it is a problem? 02-Aug-19 12:40 PM looks like platinum wire is like 12-35 bucks an inch depending on the gauge 02-Aug-19 12:40 PM Touches and a little bit of proximity 02-Aug-19 12:40 PM could build a frame out of other metal then just use the platinum where it touches 02-Aug-19 12:40 PM The boat for the 3mm disks is going to be hard 02-Aug-19 12:40 PM Also I wouldn't use map gas for this 02-Aug-19 12:40 PM Straight propane gets plenty hot and you don't want to melt the thing 02-Aug-19 12:43 PM oh yea I know, I was just saying i have the torch head, I can get a propane bottle if I don't already have one laying around 02-Aug-19 12:43 PM Yeah just letting you know 02-Aug-19 12:44 PM also 3mm? shouldn't be too hard, I was thinking a circular ring of steel wire? tungston? then making a mesh of platinum wire by tieing it across the opening then I can just sit the apeture on that? 02-Aug-19 12:44 PM sound sane? maybe? 02-Aug-19 12:44 PM It sounds doable 02-Aug-19 12:44 PM you could have the other material wire at-least a few mm away from the aperture itself and it wouldn't be "downstream" if the flame at all 02-Aug-19 12:45 PM Anyways.i have to head off 02-Aug-19 12:46 PM Alright seeya! 02-Aug-19 01:03 PM MAPP gas is easier to work with 02-Aug-19 01:03 PM since you don't need oxygen, you can just supply plain air through the mixing tube 02-Aug-19 01:03 PM but for cleaning platinum it's more of a "getting it hot quickly and not melting it" problem 02-Aug-19 01:03 PM rather than a "getting it hot enough" 02-Aug-19 01:27 PM they located my smaller freight, rescheduled for next friday 02-Aug-19 10:01 PM https://i.spirit.re/0IXN6.png https://i.spirit.re/aHZ7J.png https://i.spirit.re/GPVba.png 02-Aug-19 10:01 PM Here's a more or less final version of the vacuum system I designed out of parts I could get 02-Aug-19 10:01 PM Well, could/can. 02-Aug-19 10:01 PM Any suggestions from the more experienced gurus here? 02-Aug-19 10:01 PM The vacuum gauges are placeholders, in reality I have a PPT-100 and an IGM-400, just couldn't find CAD for those 02-Aug-19 10:13 PM I will just say... ISO 160 stuff is a PITA to find... I have ISO 160 turbos and I've been looking for adapters and bits and bobs... most I've gotten was ISO 160 to ISO 100 so far... 02-Aug-19 10:13 PM ISO 100 is much much more common 02-Aug-19 10:13 PM unless your buying new of-course 02-Aug-19 10:16 PM They're all over eBay 02-Aug-19 10:16 PM But don't steal the ones I'm looking at ;~; 02-Aug-19 10:16 PM ISO 160? 02-Aug-19 10:16 PM Yeah 02-Aug-19 10:16 PM I've seen bellows most of the time but nothing else 02-Aug-19 10:16 PM Used tubes/tees/fittings and new adapters is the combo I've been able to find 02-Aug-19 10:16 PM Adapters barely exist, but used 160 stuff is plentiful 02-Aug-19 10:17 PM Ah I see, yea quite expensive stuff but sure its there I guess 02-Aug-19 10:17 PM However the ISO160 part and everything above the topmost KF50 clamp will be added later on, as I already don't have enough money to afford everything below the clamp 02-Aug-19 10:17 PM but I did find and snag a nice KF50 VAT gate valve 02-Aug-19 10:17 PM to reduce the turbopump pucker factor 02-Aug-19 10:18 PM yea the KF40/50 throttle valves are plentiful and cheap 02-Aug-19 10:18 PM I bought a gate instead of throttle 02-Aug-19 10:18 PM much harder to blow out if you vent the whole thing to the atmosphere 02-Aug-19 10:18 PM you can use that to throttle too if its manual 02-Aug-19 10:18 PM pneumatic 02-Aug-19 10:18 PM but I might convert to electric 02-Aug-19 10:18 PM also blow out? 02-Aug-19 10:18 PM its a stainless steel disc that turns? 02-Aug-19 10:19 PM the blanked out port will be used either for a baratron later down the line, or for filling vacuum tubes 02-Aug-19 10:19 PM if a vacuum tube implodes, it'll just fill the whole chamber with air at a pretty high rate 02-Aug-19 10:19 PM worst thing that could happen is the oring could displace, but they use throttle valves all over SEMs and such 02-Aug-19 10:20 PM so I'll be roughing down first with it closed, then opening the gate valve and turning the turbo on, and then right before I use a torch to seal the tube off, I will close both valves 02-Aug-19 10:20 PM and I'll probably add a valve right before the tube 02-Aug-19 10:20 PM just the lower bit below the ISO160 adapter is going to cost me $475 in flanges, not counting the valves 03-Aug-19 08:08 PM if I wanted to get into the business of making custom valves and flanges and whatnot.. could I make a good living? 03-Aug-19 08:09 PM you'd be one foot in the grave with debt before you got the equipment to build systems that'd be highly sought after 03-Aug-19 08:09 PM flanges generally attach to something 03-Aug-19 08:09 PM that something requires manufacturing 03-Aug-19 08:11 PM hrm 03-Aug-19 08:11 PM I'm just thinking if this watchmaking thing doesn't work out.. 03-Aug-19 08:12 PM you can't really make high vacuum stuff on a watchmaking lathe 03-Aug-19 08:13 PM nobody said anything about a tiny lathe 03-Aug-19 08:13 PM you need a rather large lathe to make normal size adapters 03-Aug-19 08:13 PM my bigger one can do ~200mm diameter 03-Aug-19 08:13 PM closer to 300, but not quite 03-Aug-19 08:13 PM havent pushed it that far 03-Aug-19 08:14 PM what size of chuck? 03-Aug-19 08:15 PM well, it's more dependant on the headstock + center height (and height about the carriage) 03-Aug-19 08:15 PM the size of mounted chuck sort of gauges the size of the lathe 03-Aug-19 08:15 PM also, wouldn't it be super cute if you had a 8mm size vacuum chamber? 03-Aug-19 08:15 PM swagelok chamber :P 03-Aug-19 08:15 PM basically 03-Aug-19 08:15 PM but that was in ref to the small watchmakers lathe 03-Aug-19 08:16 PM but if you can machine something 200mm in diameter, that should be enough for making parts 03-Aug-19 08:16 PM which, I spent time yesterday looking into self compensating hydrostatic bearing spindles, super neat 03-Aug-19 08:16 PM If you just want to make basic flanges you are going to be in direct competition with shops that just turn them out all day on cnc, so at that small of scale shops usually do more custom stuff 03-Aug-19 08:16 PM yeah 03-Aug-19 08:16 PM @AdamMcCombs yeah, I hear you on that 03-Aug-19 08:16 PM you'd have to get real good at internal gas-flooded TIG to make custom stuff 03-Aug-19 08:16 PM usually in stainless 03-Aug-19 08:16 PM it was more of a side t hought, not a goal 03-Aug-19 08:17 PM Being well versed in vacuum tech/equiped with a leak detector puts you well ahead of most other shops 03-Aug-19 08:17 PM oh 03-Aug-19 08:17 PM oh yeah, that too 03-Aug-19 08:17 PM *general machine shops 03-Aug-19 08:17 PM you'd need to leak test custom stuff 03-Aug-19 08:18 PM The big vacuum shops in the north west are the UW physics instrumentation shop and Thermionics Vacuum 03-Aug-19 08:18 PM I'm going to try building a thermocouple equilibrium leak detector 03-Aug-19 08:18 PM spin the turbo down until the vacuum doesn't change, zero it out, and turn the gain up a few orders of magnitude 03-Aug-19 08:18 PM then flow helium on 03-Aug-19 08:19 PM That being said if you can produce interciate mechanical assemblies that are fully vacuum compatible it's definitely in demand 03-Aug-19 08:19 PM ah, interesting to note 03-Aug-19 08:19 PM You don't necessarily have to make the massive stuff to make useful stuff 03-Aug-19 08:19 PM you know.. incase this other thing doesnt work out 03-Aug-19 08:20 PM If you want to see insanity look at TEM sample rods 03-Aug-19 08:20 PM TEM requires slices that are of very little use normally 03-Aug-19 08:20 PM sadly 03-Aug-19 08:21 PM neat lil things though 03-Aug-19 08:22 PM https://images.app.goo.gl/vrTXUiBD2KgFXAjz7 03-Aug-19 08:22 PM a SEM without the detector, basically 03-Aug-19 08:22 PM a very fancy CRT 03-Aug-19 08:22 PM :P 03-Aug-19 08:22 PM I'm going to fundamentally disagree with the TEM statement 03-Aug-19 08:22 PM But I'm pretty biased... 03-Aug-19 08:23 PM I'd be biased too if I had a TEM! 03-Aug-19 08:23 PM I'm biased that way in terms of thermal and high speed imaging, given my rather nice collection of cameras 03-Aug-19 08:24 PM It's not the right tool for every job, but the capital value of the instrumentation is so high that you can specialized and make a nice living at it 03-Aug-19 08:24 PM And custom holders are definitely a big deal. There is not many places that can do good one off interciate mechanical assemblies for special experiments 03-Aug-19 08:25 PM The entire hacker community needs to crowdfund a KERN micromachining center 03-Aug-19 08:25 PM those machines hold +-2um for years if run all the time 03-Aug-19 08:25 PM and can machine parts you need a microscope to see 03-Aug-19 08:25 PM anything smaller you can just knock down with a FIB! :P 03-Aug-19 08:27 PM If you want to see someone doing tem stuff locally @Noxz check out hunting bird scientific 03-Aug-19 08:27 PM *huming 03-Aug-19 08:28 PM looking.. 03-Aug-19 08:28 PM http://hummingbirdscientific.com/ 03-Aug-19 08:28 PM yeah, hrm 03-Aug-19 08:29 PM how does positioning work? 03-Aug-19 08:29 PM MEMS? Piezo? 03-Aug-19 08:29 PM In what exactly? 03-Aug-19 08:29 PM ine the image he posted, piezo 03-Aug-19 08:29 PM positioning the sample in the beam 03-Aug-19 08:29 PM Goiniometer stage 03-Aug-19 08:29 PM purely mechanical, then raster offset? 03-Aug-19 08:30 PM Mechanical for coarse, electromagnetic for fine 03-Aug-19 08:30 PM I keep thinking of overcomplicated solutions 03-Aug-19 08:30 PM That goes for all axis including tilt 03-Aug-19 08:31 PM these are really cool things, hrmm 03-Aug-19 08:31 PM Yeah insitue TEM is crazy cool 03-Aug-19 08:31 PM Combine one of those insitue holders wit an atomic resolution TEM, add a fempto second pulsed electron source, and a static deflector to a high speed direct electron camera and you have a time domain resolved atomic video camera recording material or environmental interactions 03-Aug-19 08:34 PM When things start sounding like buzz words, you know you're at the bleeding edge 03-Aug-19 08:34 PM anyone know where I can get exact dimensions for CF flanges 03-Aug-19 08:35 PM either googling, or if you want a 3d model, find some adapters on idealvac 03-Aug-19 08:35 PM they all have step files 03-Aug-19 08:35 PM hmm I guess that could work 03-Aug-19 08:35 PM most dimensions just come as picture drawings 03-Aug-19 08:36 PM I mean I tried googling and I get some stuff like the bolt circle but not the specific dimensions of the knife edge and such 03-Aug-19 08:36 PM yeah go to idealvac for that 03-Aug-19 08:36 PM measure in something like inventor or fusion360 03-Aug-19 08:36 PM makes it a lot easier for me to understand dimensions for DIYing stuff 03-Aug-19 08:36 PM and you can create your own drawings 03-Aug-19 08:37 PM yeah I'm working on making a solidworks model for my cold trap which has some 10" CF flanges 03-Aug-19 08:37 PM yeah solidworks is fine too 03-Aug-19 08:37 PM I think there's even sldprt files for them 03-Aug-19 08:37 PM not only step 03-Aug-19 08:37 PM oh nice 03-Aug-19 08:37 PM 10" CF is ouchie though 03-Aug-19 08:37 PM the copper alone costs more than a few flanges for my system 03-Aug-19 08:38 PM I'm not trying to achieve the pressures needed for CF, so I'm thinking I might be able to get away with a kludge 03-Aug-19 08:38 PM well, copper is copper is copper 03-Aug-19 08:38 PM oxygen-free is a good idea 03-Aug-19 08:39 PM well I just mean my adapter plate need not actually have a CF flange 03-Aug-19 08:39 PM which would be the expensive part 03-Aug-19 08:39 PM are you making a custom adapter from 10"? 03-Aug-19 08:39 PM from my diff pump which has a weird proprietary flange to 10" 03-Aug-19 08:39 PM my condolences 03-Aug-19 08:40 PM I'm saying I'm not going to try to use the full conductance of that 10" orifice 03-Aug-19 08:40 PM just the dimensions alone make it painful 03-Aug-19 08:40 PM even if it's a straight hole adapter 03-Aug-19 08:41 PM I suspect I can do this in a way that will need no welds or large diameter lathe 03-Aug-19 08:41 PM but I may be biased as I'm cheap and I will be turning my own ISO63 to NW50 adapter, which is only $40ish 03-Aug-19 08:41 PM you will absolutely need a way to machine at least an o-ring groove 03-Aug-19 08:41 PM I will soon have free access to a large CNC mill 03-Aug-19 08:42 PM a mill will do the trick 03-Aug-19 08:42 PM can't easily machine a knife edge without a custom shape tool though 03-Aug-19 08:42 PM yeah I realize that 03-Aug-19 08:42 PM so get free access to a grinder and some scrap carbide endmills first :P 03-Aug-19 08:42 PM hence me mentioning a kludge 03-Aug-19 08:43 PM rough it down with something like a ball mill 03-Aug-19 08:43 PM then chase it with a form tool 03-Aug-19 08:44 PM this is the mill (plus some CNC conversion stuff) https://www.elitemetaltools.com/tool-shop/products/acra-precision-milling-machine-am2ac 03-Aug-19 08:44 PM doesn't really matter here 03-Aug-19 08:44 PM as long as you can gen the code 03-Aug-19 08:45 PM yeah 03-Aug-19 08:45 PM thankfully HSM is the same for inventor and solidworks 03-Aug-19 08:45 PM both are made by autodesk 03-Aug-19 08:45 PM solidworks is by dassault systemes 03-Aug-19 08:45 PM not autodesk 03-Aug-19 08:45 PM yeah, the CAM module is usually HSM Express 03-Aug-19 08:45 PM which made by Autodesk 03-Aug-19 08:45 PM :P 03-Aug-19 08:45 PM ah okay 03-Aug-19 08:47 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/a-Original-CERN-knife-design-b-Modified-de-13874.png 03-Aug-19 08:47 PM nice is that from the ISO standard or something 03-Aug-19 08:47 PM CERN developed it it's from that 03-Aug-19 08:48 PM in this case I would still advise to download the model from idealvac 03-Aug-19 08:48 PM because it's easy to make a mistake :P 03-Aug-19 08:48 PM ISO 3669 is what I meant 03-Aug-19 08:48 PM There's several variants on the base standard 03-Aug-19 08:49 PM I need to bug my CERN mates to bug the high vacuum guys and ask how they manage standards 03-Aug-19 08:49 PM I think that one is the CERN one with the slightly different life edge angle 03-Aug-19 08:49 PM copper generally takes up the slack 03-Aug-19 08:49 PM thankfully I only have one CF part, the PPT-100 pirani 03-Aug-19 08:49 PM and I will be immediately converting that to KF, because I'm not made of gold 03-Aug-19 08:56 PM this was pretty neat.. https://www.youtube.com/watch?v=FJ83hHDwOB8 03-Aug-19 08:57 PM Kleindiek is also a pretty cool company 03-Aug-19 08:57 PM Lot of very precise piezo gear 03-Aug-19 08:58 PM obviously 03-Aug-19 08:59 PM I'm going to see humingbird and kleindiek on Monday actually 03-Aug-19 09:00 PM how about that 03-Aug-19 09:00 PM that conferance thing? 03-Aug-19 09:00 PM Yeah 03-Aug-19 09:00 PM Unfortunately all of their hardware is too new so I haven't found any for free... 03-Aug-19 09:04 PM You should start a YouTube channel about the stuff you do 03-Aug-19 09:04 PM Once you're popular enough, things start to become free ;) 03-Aug-19 09:05 PM I actually have one 03-Aug-19 09:05 PM Haven't used it in a long time 03-Aug-19 09:05 PM I need this for watches.. https://www.youtube.com/watch?v=w_DsOIMZCbo 03-Aug-19 09:05 PM I streamed me working on scopes when I first started and didn't actually have a job in the industry 03-Aug-19 09:05 PM It's funny looking back at how naive I was 03-Aug-19 09:06 PM I'm very into pro video and cine stuff, I can help with starting from scratch easily 03-Aug-19 09:06 PM I plan on doing YT stuff for watchmaking once I finish up school 03-Aug-19 09:06 PM The stuff you do, even if not presented in a talk-like fashion, would definitely be a hit in the nerd world 03-Aug-19 09:06 PM more for promotion 03-Aug-19 09:07 PM I used to run a production company with friends so I have got that stuff under control 03-Aug-19 09:07 PM Oh, that's great then 03-Aug-19 09:07 PM Recording a bunch of b-roll and commentary on top is probably the easiest thing to setup 03-Aug-19 09:08 PM why is it naive to stream yourself working on scopes? 03-Aug-19 09:08 PM I was naive relating to the scopes 03-Aug-19 09:08 PM I think I'm at that stage right now 03-Aug-19 09:09 PM oh I see 03-Aug-19 09:09 PM But I can't afford to ship a scope over here, even though I found several that are in my budget 03-Aug-19 09:09 PM I'm pretty sure I'll always look back and feel niave 03-Aug-19 09:09 PM Yeah shipping can be a pain 03-Aug-19 09:09 PM if not, you're not learning anything 03-Aug-19 09:09 PM I think we all look naive to older selves 03-Aug-19 09:10 PM hah, I found out about shipping... so far havent recieved anything via freight, recently at least (got some building material a few years ago that was fine) 03-Aug-19 09:10 PM I bought an industrial robot via freight once 03-Aug-19 09:10 PM they keep misplacing the item 03-Aug-19 09:10 PM Shipping a single 120kg pallet from Italy to Belarus(via ground!) cost me over $200 03-Aug-19 09:10 PM Yeah I try to never never use freight 03-Aug-19 09:10 PM Van line service is where it's at 03-Aug-19 09:11 PM that's way less than I'd have expected, actually 03-Aug-19 09:11 PM I went with a local company, not a big shipper 03-Aug-19 09:11 PM (I have never shipped anything big) 03-Aug-19 09:11 PM it gets cheaper if you go bigger/heavier 03-Aug-19 09:11 PM much of that cost is simply in 'gas' and storage 03-Aug-19 09:11 PM or rather, pickup/dropoff 03-Aug-19 09:12 PM Those Amrays and JEOLs that are all over eBay(all in the US) would cost me roughly $1500-2000 to ship(1 metric ton, 3m^3) 03-Aug-19 09:12 PM (but I paid like $400 for movers to move my stuff 1 mile over 1.5 hours recently, so it sounds cheap) 03-Aug-19 09:12 PM And another ~$4000 to clear customs 03-Aug-19 09:12 PM ;~; 03-Aug-19 09:12 PM So while some scopes are under $500, shipping and customs end up being impossible obstacles 03-Aug-19 09:13 PM luckily, I live in silicon valley, so I'm pretty confident that if I wanted a scope, I could find a localish (20 miles) pickup. unfortunately, I live in silicon valley, so I will never be able to afford a place that has enough room for a scope. 03-Aug-19 09:14 PM Oh I have no room for a scope 03-Aug-19 09:14 PM But if I had a chance to buy one, I'd still buy one 03-Aug-19 09:14 PM I am very miffed that I had the chance to buy a JEOL JSM 6-something for $1200, in full kit and full working order, a couple hours away on a truck 03-Aug-19 09:14 PM And I passed on it 03-Aug-19 09:15 PM my last place in San Jose could not house a SEM.. not inside at least, there was a full gated backyard though 03-Aug-19 09:15 PM build a lil workshop out there if need be 03-Aug-19 09:17 PM I got lucky and got the only apartment in my complex that has a 200 sq ft concrete backyard area, but it's useless for this kind of thing because it rains in the winter 03-Aug-19 09:17 PM yeah, well, I was basically in a converted attic at that last place 03-Aug-19 09:17 PM before that was a nice sized loft, but they tried to increase my rent by 30% the next year, thus moving to the attic 03-Aug-19 09:18 PM that sucks 03-Aug-19 09:18 PM bay area housing is awful 03-Aug-19 09:18 PM yeah, Seattle isnt much better 03-Aug-19 09:18 PM I mean, half the price, but meh 03-Aug-19 09:18 PM maybe 3/4 the price 03-Aug-19 09:18 PM all depends wha tyou want 03-Aug-19 09:18 PM at least there are plenty of spots available though 03-Aug-19 09:18 PM for houses that is 03-Aug-19 09:18 PM apartments are another story 03-Aug-19 09:18 PM and I dont know the full story there 03-Aug-19 09:18 PM k, time for some tv shows 03-Aug-19 09:18 PM I'll be sure to keep 'In Situ TEM Probes' in my back pocket 03-Aug-19 10:48 PM Joined the server. 03-Aug-19 10:49 PM Welcome! 03-Aug-19 10:51 PM hello 03-Aug-19 10:51 PM I worked in an UHV lab for a while 03-Aug-19 10:53 PM I invited a few friends from a small science server 03-Aug-19 10:56 PM whats this server about 03-Aug-19 10:59 PM In general, anything relating to vacuum generation or processes that need vacuum 03-Aug-19 10:59 PM That being said, things that require vacuum are pretty diverse, so the technologies we talk about here are similarly so 03-Aug-19 10:59 PM Also moving large things comes up quite a bit 03-Aug-19 11:01 PM It's also filled with the best nerds of... twitter? 03-Aug-19 11:01 PM Yeah 03-Aug-19 11:01 PM Most of us met on Twitter 03-Aug-19 11:01 PM I was a lurker and only recently discovered that everyone was interconnected 03-Aug-19 11:01 PM Which mostly consisted of "whoa click" over and over 03-Aug-19 11:02 PM Lol 03-Aug-19 11:02 PM Lurker on Twitter or? 03-Aug-19 11:02 PM Yeah 03-Aug-19 11:04 PM When it came down to it there was a bunch of threads on Twitter relating to vacuum stuff and it was quickly getting out of hand so qualia and I set this up 03-Aug-19 11:05 PM I kept diving into threads about this and was wondering why it wasn't discussed anywhere outside of twitter 03-Aug-19 11:05 PM Then someone invited me here 03-Aug-19 11:06 PM It seemed like the other vacuum place in the internet was the fusor.net form 03-Aug-19 11:06 PM Which... Well @GigaSquirrel can speak to that 03-Aug-19 11:06 PM And now we have a radiation channel! 03-Aug-19 11:06 PM I tried signing up, didn't even get a confirmation email 03-Aug-19 11:06 PM I'm pretty well-versed in nuc so if anyone needs help in terms of that, ping me in #radiation 03-Aug-19 11:06 PM I've also invited a friend that works at the bleeding edge of particle physics 03-Aug-19 11:08 PM A lot of my work as an undergrad was maintaining an approximately 5x10^-11 mbar chamber 03-Aug-19 11:08 PM Baking, TSP, ion pumps... all that jazz 03-Aug-19 11:09 PM Fun times 03-Aug-19 11:09 PM I'm not looking forward to cleaning and baking my first chamber 03-Aug-19 11:10 PM why not it’s fun 03-Aug-19 11:10 PM Im know in advanced I'm going to hate myself for it but I'm looking at a doing a system soon that goes from -3 and differentially pumps to -12 03-Aug-19 11:10 PM Field emission? 03-Aug-19 11:10 PM Yup 03-Aug-19 11:10 PM Vacuum stabilized cold feg 03-Aug-19 11:11 PM I wonder if it's possible to make gettered vacuum chambers 03-Aug-19 11:11 PM Yeah 03-Aug-19 11:11 PM er, vacuum tubes 03-Aug-19 11:11 PM That's what TSP is 03-Aug-19 11:11 PM Ah 03-Aug-19 11:11 PM getter pumps exist, but I had this crazy idea of building an x-ray tube with a LaB6 filament 03-Aug-19 11:12 PM I definitely wouldn't seal it in a tube 03-Aug-19 11:12 PM If you don't need the micro focus you can get with lab 6 then zerconium makes way more sense due to much long source life 03-Aug-19 11:13 PM regular x-ray tubes are a dime a dozen 03-Aug-19 11:13 PM I have a brand new spare one that I'll give away for peanuts 03-Aug-19 11:13 PM but microfocus is very, very expensive and complicated 03-Aug-19 11:13 PM I don't think lab6 actually increases resolution over tungsten when used in micro focus x Ray 03-Aug-19 11:13 PM it'd be more durable 03-Aug-19 11:13 PM and not evaporate everywhere 03-Aug-19 11:14 PM Longevity yes but if you look at lab6 wrong it breaks 03-Aug-19 11:14 PM Lol no lab6 covers everything it's awful 03-Aug-19 11:14 PM Takes forever to clean the lab6 off of everything 03-Aug-19 11:15 PM Oh, I was under the impression that it doesn't evap 03-Aug-19 11:15 PM A field emission tungsten x-ray tube... hm.... 03-Aug-19 11:15 PM Yeah no 03-Aug-19 11:15 PM The lanthanum residue cause problems with the electron beam as well 03-Aug-19 11:15 PM Pluss lab 6 doesn't like to be turned off 03-Aug-19 11:16 PM Someone is talking about sending me a giant Yxlon microfocus tube, rated at 160kV @ 3mA and 6um focus 03-Aug-19 11:16 PM It takes 15-20 minutes minimum to warm up as well. And sometimes it just breaks on warm up because why wouldn't it 03-Aug-19 11:16 PM The thing is just designed to have a 24/7 turbopump spinning directly on it 03-Aug-19 11:17 PM 3mA is pretty damn respectible 03-Aug-19 11:18 PM Why not use the normal Al or Mg for an x-ray source 03-Aug-19 11:18 PM It seems to have been scrapped and marked as "leaky 1*10^-9 Torr/min He" 03-Aug-19 11:18 PM but... free tube is free tube. 03-Aug-19 11:18 PM What's the source on it? 03-Aug-19 11:18 PM Yeah free tube ftw 03-Aug-19 11:18 PM Source? 03-Aug-19 11:18 PM Electron source 03-Aug-19 11:19 PM Oh, tungsten I'm guessing 03-Aug-19 11:19 PM It's a black box, I'm just saying "yes please give it to me" 03-Aug-19 11:19 PM Yeah at 6um you are really not going to see a performance improvement with lab6 or feg 03-Aug-19 11:20 PM if I can DIY a 75kV 10um tube, I'd be extremely happy 03-Aug-19 11:20 PM I mean if you want a longer life between changes then yeah lab6 makes total sense 03-Aug-19 11:20 PM current isn't that important, since my C9732 detector seems to detect an x-ray sneeze 03-Aug-19 11:20 PM 10um should be doable with straight static optics 03-Aug-19 11:21 PM that's what I'm thinking 03-Aug-19 11:21 PM Soviet oscilloscope tubes are very simple to hack, so I'm hoping I can mod them to squeeze the focus down to x-ray/crappy SEM levels 03-Aug-19 11:23 PM If you get clever about it you can use a bunch of dividers instead of separate supplies and if you set everything up right and ripple in voltage causes an equivalent change in focus/defocus and you maintenan a stable spot 03-Aug-19 11:23 PM that's how Soviet microfocus tubes work! 03-Aug-19 11:23 PM they have a third pin connected to the wehnelt and somehow coupled to other focusing things inside 03-Aug-19 11:25 PM Well best of luck with your project. I'm off to bed, early morning tomorrow 03-Aug-19 11:25 PM Thanks 03-Aug-19 11:25 PM I should be sleeping too 04-Aug-19 01:12 AM Whey, finally some x-ray talk! 04-Aug-19 01:12 AM @Deleted User sounds like you've done a lot in the area, do you have a website etc? 04-Aug-19 03:49 AM Joined the server. 04-Aug-19 09:29 AM @GigaSquirrel I do, but I haven't posted there much 04-Aug-19 09:29 AM It's https://spirit.re/ 04-Aug-19 09:29 AM @Moist Mayonnaise is someone who does stuff at CERN 04-Aug-19 09:32 AM no im not 04-Aug-19 09:32 AM Joined the server. 04-Aug-19 09:32 AM He does something and it often results in beam dumps 04-Aug-19 09:32 AM And then he gets sad. 04-Aug-19 09:33 AM i dont get sad 04-Aug-19 09:33 AM Not denying beam dumps though 04-Aug-19 09:33 AM He knows a lot about particle physics and is sometimes scary about it 04-Aug-19 09:34 AM no i dont no im not 04-Aug-19 09:34 AM shhh 04-Aug-19 09:36 AM DAE love changing tipseals on scroll pumps 04-Aug-19 09:50 AM Joined the server. 04-Aug-19 09:58 AM Joined the server. 04-Aug-19 10:00 AM @Goldsteel is the guy working on high end nuclear physics 04-Aug-19 10:00 AM He builds the things that scientists use 04-Aug-19 10:01 AM technically only i use them right now 04-Aug-19 10:01 AM i do a lot of things 04-Aug-19 10:01 AM im not actually a nuclear physicist but i work with HPGe detectors 04-Aug-19 10:03 AM The practical side of things is more fun 04-Aug-19 10:03 AM i dunno 04-Aug-19 10:03 AM i do what i need to do 04-Aug-19 10:03 AM playing with sources that are hotter than I'd consider putting in my lab is also a perk 04-Aug-19 10:03 AM thats true 04-Aug-19 10:03 AM and y'know, casually manufacturing eu-152 for calibration 04-Aug-19 10:04 AM and the rest 04-Aug-19 10:04 AM its fairly trivial to tailor your neutron tank to specific energies for the activation of salt samples 04-Aug-19 10:04 AM its about as easy as putting blocks of graphite under water and then putting the sample on a fishing rod and leaving it there for a few hours, then putting it under the detector to check the spectra 04-Aug-19 10:05 AM If you look at the names @Goldsteel you might recognize that most of the people here are from the cool science side of twitter 04-Aug-19 10:05 AM i dont use twitter 04-Aug-19 10:05 AM I don't either but I did notice 04-Aug-19 10:07 AM im honestly quite adverse to a lot of the social media stuff going on 04-Aug-19 10:07 AM discord is fine for me most of the time 04-Aug-19 10:09 AM finally the nuclear physics Side is more represented on this Server 04-Aug-19 10:09 AM welcome, all of you new people! 04-Aug-19 10:10 AM im actually a particle physicist interested in muon physics for the purpose of measuring anomalous and rare decays 04-Aug-19 10:10 AM the process of discovering those decays requires me to understand the interactions of exotic radiation with matter, and the smoking gun of certain decays is nuclear transitions with defined energies only made possible by BSM physics 04-Aug-19 10:10 AM which requires me to study nuclear physics as well as understand how to operate high precision gamma ray spectrometers 04-Aug-19 10:10 AM i build them using HPGe systems 04-Aug-19 10:12 AM ohhh, sweet! 04-Aug-19 10:12 AM I've got a couple of HPGes myself, but they still need to be repaired... 04-Aug-19 10:12 AM as a consequence as spirit mentioned it also means i have to quantify the backgrounds and performance at different energy scales 04-Aug-19 10:12 AM right now most of our detectors are going for annealing again 04-Aug-19 10:13 AM with my sources luckily I don't need that 04-Aug-19 10:13 AM i need to make them survive a collimated beam of 10^12 neutrons/cm^2 04-Aug-19 10:13 AM 23 hours of operation is all i can squeeze out of a 200 grand crystal 04-Aug-19 10:14 AM doesn't that activate the hell out of your crystal? 04-Aug-19 10:14 AM i honestly dont know 04-Aug-19 10:14 AM I'd be more concerned with that than damaging the crystal lattice 04-Aug-19 10:14 AM they just go for annealing in containment 04-Aug-19 10:14 AM it does 04-Aug-19 10:14 AM which is why they go for annealing 04-Aug-19 10:14 AM the plan right now is to just get a bigger crystal and 'scan' across the surface circle 04-Aug-19 10:14 AM destroying sections of the Ge but preserving others 04-Aug-19 10:14 AM ill have to figure out the line spacing 04-Aug-19 10:14 AM ive proposed the idea of using PTFE to thermalise the neutrons far before they reach the detector since it doesnt attenuate the gammas much but people all recoil at the prospect of arguably the most intense thermal neutron pulses on the planet 04-Aug-19 10:14 AM so back to stage 1 04-Aug-19 10:14 AM 'burn a bit less of it' 04-Aug-19 10:17 AM are you sure? Our reactor here does like 10^20 n/cm²*s thermal 04-Aug-19 10:18 AM over what area 04-Aug-19 10:18 AM there are plenty of reactors with high throughput 04-Aug-19 10:18 AM the problem we have is that we are putting an enormous amount through the eye of a needle, with all the bunching on the order of uS per shot 04-Aug-19 10:20 AM ah, you're right, the reactor does 10^18, but at the experiments it's only 10^10 n/cm²*s, over a couple of cm² 04-Aug-19 10:20 AM these neutrons are also monochromatic 04-Aug-19 10:20 AM yeah 04-Aug-19 10:20 AM the way i make them is i bombard aluminium wafers with muons at the GeV range and some get captured, and converted by electron capture, emitting a neutron in the process sometimes 04-Aug-19 10:20 AM the end result is a horrifying death ray of monochromatic fast neutrons 04-Aug-19 10:22 AM (can you post pics?) 04-Aug-19 10:22 AM no 04-Aug-19 10:22 AM :< 04-Aug-19 10:22 AM HK wouldnt let me either 04-Aug-19 10:22 AM idk how many experiments let you show off their hardware honestly 04-Aug-19 10:22 AM the japanese wouldnt even let us smile in photographs because it was seen as unprofessional 04-Aug-19 10:22 AM theyre doing the same thing at COMET 04-Aug-19 10:24 AM too bad 04-Aug-19 10:24 AM people get iffy about me taking photographs of things 04-Aug-19 10:24 AM ive still sneaked a few 04-Aug-19 10:25 AM tbh I never got the secrecy about stuff like this 04-Aug-19 10:25 AM I've been in a couple of research reactors and accelerators so far, and everyone is like "ehh better not take pictures" 04-Aug-19 10:25 AM of course, if it is some current work you want to publish first I get it, but standard stuff everyone can google in like 5 minutes? 04-Aug-19 10:27 AM the US DoE hates photos and the KEK group and SK/HK people also hate photos 04-Aug-19 10:27 AM also JPARC hate photos 04-Aug-19 10:27 AM oh 04-Aug-19 10:28 AM heh 04-Aug-19 10:28 AM yeah, I know, but I don't get why 04-Aug-19 10:28 AM im not even allowed to take photos of the computing platforms, it warns you on login 04-Aug-19 10:28 AM any photos are property of the US government (?) i think 04-Aug-19 10:28 AM not sure 04-Aug-19 10:28 AM i was told to not 04-Aug-19 10:29 AM oh, lol 04-Aug-19 10:32 AM I’ll have to check in my phone before entering the lab at LANL. No chance of sneaking a pic or anything 04-Aug-19 10:33 AM ohhh you work at LANL? 04-Aug-19 10:34 AM I’ve accepted a job but I don’t start for a month or so :) 04-Aug-19 10:34 AM congrats! 04-Aug-19 10:34 AM may I ask / can you tell what you'll be doing? 04-Aug-19 10:34 AM thank you! Its a dream job tbh 04-Aug-19 10:35 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/elena-F5564.jpg 04-Aug-19 10:35 AM Sure. I’ll be a research technologist at the DARHT facility. Basically I’ll be involved in building and using diagnostic equipment for the facility. 04-Aug-19 10:36 AM oh wow 04-Aug-19 10:37 AM I can’t wait to get started 04-Aug-19 10:37 AM oh I totally get that 04-Aug-19 10:37 AM LANL is on the list of places I have to visit at some time 04-Aug-19 10:39 AM mayo presents: 04-Aug-19 10:39 AM canned antimatter (tm) 04-Aug-19 10:39 AM The town is really neat. Lots of history to absorb if you’re into that! 04-Aug-19 10:39 AM It was snowing during my interview so it was also very pretty 04-Aug-19 10:40 AM tbh all I really know are the texts of feynman about los alamos, but they paint a wonderful picture 04-Aug-19 10:40 AM I'm sure a lot has changed today, but still 04-Aug-19 10:41 AM Ok I'm leaving for a conference soon but I have to say please don't post photos that shouldn't exist some of us have to be careful around that 04-Aug-19 10:41 AM Carry on about cool nuclear stuff 04-Aug-19 10:41 AM The whole place feels like a time capsule tbh. They have preserved the original security gate and buildings 04-Aug-19 10:41 AM With statues of some of the people involved 04-Aug-19 10:42 AM oh wow 04-Aug-19 10:42 AM now I really want to go there 04-Aug-19 10:42 AM Lemme find the photo of the statue it’s really cool 04-Aug-19 10:43 AM I found one of oppenheimer and the general(?) 04-Aug-19 10:43 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_5934-19518.JPG 04-Aug-19 10:43 AM infront of what looks like one of the old school buildings 04-Aug-19 10:43 AM Yup 04-Aug-19 10:43 AM yep 04-Aug-19 10:44 AM I only walked around a bit when I visited. Didn’t get to explore the museums or anything. But I’m looking forward to checking them out 04-Aug-19 10:44 AM is it possible for an individual to get in there or do you have to work in something related? 04-Aug-19 10:45 AM You can visit the town easily it’s all public 04-Aug-19 10:45 AM There is only a security checkpoint to enter the lab area 04-Aug-19 10:46 AM plans out trip 04-Aug-19 10:47 AM Nice :) lemme know if you end up going. I may have some suggestions after living out there for a while! 04-Aug-19 10:47 AM I will, for sure! 04-Aug-19 10:47 AM it's just gonna be a lot of money, as I live in germany 04-Aug-19 10:48 AM Yeah that would be quite the trip 04-Aug-19 10:49 AM I will go at some point, there's a lot in the USA I want to visit 04-Aug-19 10:49 AM I want to go for a tour of CERN and bug mayo and another friend in person 04-Aug-19 10:49 AM just might take some time 04-Aug-19 10:50 AM @Ouais you work with the DARHT accelerator? 04-Aug-19 10:50 AM nobody ever bugs me 04-Aug-19 10:50 AM I don't remember where you work @Goldsteel 04-Aug-19 10:50 AM NOBODY DOES 04-Aug-19 10:50 AM I do 04-Aug-19 10:50 AM do you 04-Aug-19 10:50 AM now that's how security should work 04-Aug-19 10:51 AM my security feature is nobody cares about my experiments 04-Aug-19 10:51 AM I'll come bug you if you tell me where you work @Goldsteel 04-Aug-19 10:51 AM oh no 04-Aug-19 10:51 AM I can't promise I won't nick a few neutrons in a matchbox to take home 04-Aug-19 10:51 AM empty your pockets sonny jim 04-Aug-19 10:51 AM thats right 04-Aug-19 10:51 AM i thought so 04-Aug-19 10:51 AM 7 neutrons and a gamma ray 04-Aug-19 10:51 AM you're in the nick now 04-Aug-19 10:52 AM not if I activate myself 04-Aug-19 10:52 AM and decay 04-Aug-19 10:52 AM "you cant kill me, i kill me!" 04-Aug-19 10:53 AM just enough for a healthy glow 04-Aug-19 10:54 AM @Applied_Ion I will. Haven’t started yet 04-Aug-19 10:54 AM That's awesome lol 04-Aug-19 10:55 AM youre telling me!! haha 04-Aug-19 10:55 AM You can say the darht accelerator is of particular interest to me 04-Aug-19 10:55 AM Nice 04-Aug-19 10:55 AM Well I’ll be able to tell you more once I’m there (as long as the info isn’t classified :p ) 04-Aug-19 10:56 AM You bet it will be 04-Aug-19 10:57 AM The details I need on the system is readily available, I'd just love to see it 04-Aug-19 10:57 AM I didn’t even get a proper tour of it when I visited because a snow storm knocked out all the power lol 04-Aug-19 10:59 AM What will you be doing there? 04-Aug-19 11:03 AM Mostly beam diagnostics, building and using various spectrometers 04-Aug-19 11:06 AM just the stuff @Applied_Ion is into 04-Aug-19 11:08 AM nice 04-Aug-19 11:08 AM did we just become best friends? 04-Aug-19 11:08 AM Well, firstly building the actual accelerator lol 04-Aug-19 11:08 AM :o 04-Aug-19 11:08 AM You might really like my accelerator build lol 04-Aug-19 11:09 AM I’m interested 04-Aug-19 11:10 AM I think you could find plenty of use cases for it, especially with experience at LANL 04-Aug-19 11:11 AM looks like it's finally time to reveal it 04-Aug-19 11:11 AM I’m really a noob at all things accelerators right now. My undergrad experience was just spectroscopy 04-Aug-19 11:11 AM But hopefully that changes in the near future 04-Aug-19 11:11 AM Not quite yet. I want the parts at leat machined for it 04-Aug-19 11:11 AM Right now it was between thrusters or accelerator, and there was more momentum for thrusters, so I gotta split cost 04-Aug-19 11:13 AM ehehehe momentum 04-Aug-19 11:13 AM But I'm so close to beam I can almost taste it 04-Aug-19 11:13 AM Lol no pun intended for that 04-Aug-19 11:13 AM ah yes, the wonderful taste of metal 04-Aug-19 11:14 AM Is this an electron accelerator like DARHT? 04-Aug-19 11:14 AM I mean momentum lol. Wonder what the beam would taste like though... 04-Aug-19 11:14 AM I imagine like radiation burns 04-Aug-19 11:14 AM @Ouais depends 04-Aug-19 11:14 AM Given that the beam would be at least a few hundred kev 04-Aug-19 11:14 AM and electrons 04-Aug-19 11:14 AM Which makes it beta :P 04-Aug-19 11:15 AM I would say yes and no to that 04-Aug-19 11:15 AM Well, more accurately, in part 04-Aug-19 11:16 AM The best non-obvious advice when dealing with beta is, and I'm not kidding, wear safety goggles 04-Aug-19 11:16 AM Because it fries your eyes much faster than anything else 04-Aug-19 11:18 AM Oh I'm not gonna be anywhere near this when it fires, xrays will be way too high in all cases but first testing at maybe 30kV. Still can't run it to 300kv for quite a while 04-Aug-19 11:18 AM Yeah this advice only really works with actual beta sources 04-Aug-19 11:18 AM i still dont know if i believe you spirit 04-Aug-19 11:18 AM i dont have that problem with my sources 04-Aug-19 11:18 AM i dont stare at them though 04-Aug-19 11:19 AM I verified it empirically and very stupidly 04-Aug-19 11:19 AM But it's not a huge issue 04-Aug-19 11:19 AM im not sure i want to put these near my eyes 04-Aug-19 11:20 AM If you do anything to do permanent eye damage(which I do not have), you have to worry about actual burns around your other parts 04-Aug-19 11:20 AM But I did get some eye strain which was scary 04-Aug-19 11:20 AM whats your source activity 04-Aug-19 11:20 AM not enough 04-Aug-19 11:20 AM but it was too close. 04-Aug-19 11:21 AM well ive looked at my 800kBq source just fine emitting beta 04-Aug-19 11:21 AM no eye effects 04-Aug-19 11:21 AM maybe 10cm distance? 04-Aug-19 11:21 AM could've been placebo 04-Aug-19 11:21 AM i dont wear goggles but i do wear nitrile 04-Aug-19 11:21 AM but I don't know how that would happen since I only found out beta had that effect after I was done with the testing 04-Aug-19 11:21 AM how far does beta even travel 04-Aug-19 11:21 AM I forget 04-Aug-19 11:22 AM depends 04-Aug-19 11:22 AM one, two, maybe three meters in air 04-Aug-19 11:22 AM well yeah but it open air 04-Aug-19 11:22 AM oic 04-Aug-19 11:22 AM depends on the energy, air pressure 04-Aug-19 11:22 AM thought it was much shorter 04-Aug-19 11:22 AM maybe I’m thinking of alphas 04-Aug-19 11:22 AM whatever is in the way too 04-Aug-19 11:22 AM anyone up for voicechatting today? 04-Aug-19 11:22 AM alphas are stopped by paper 04-Aug-19 11:22 AM yes 04-Aug-19 11:23 AM haven't done it in a while 04-Aug-19 11:23 AM yep, I'd be in 04-Aug-19 11:23 AM what time works for everyone? 04-Aug-19 11:24 AM 2100 berlin time, as usual? That would be in ~30 min 04-Aug-19 11:24 AM allthough I might join a bit later 04-Aug-19 11:24 AM I have a few micrograms of Am-241, and it's really bizarre to see that while the source can peak at like a few hundred kHz in terms of count rate 04-Aug-19 11:24 AM But when I put a piece of paper in front of the detector, all of it just stops, and you get just a bit of gamma 04-Aug-19 11:24 AM but americium gammas are so minuscule they're harmless 04-Aug-19 11:25 AM that bit of gamma quickly adds up tho 04-Aug-19 11:25 AM not from americium 04-Aug-19 11:26 AM https://www.youtube.com/watch?v=vuOvGY0QWSg 04-Aug-19 11:26 AM my source barely registers on a shielded gamma detector 04-Aug-19 11:26 AM and it's a lot less than 3.7 GBq :P 04-Aug-19 11:27 AM I only deal with sources I'm confident I can store correctly 04-Aug-19 11:27 AM And that would not be the case with 3.7GBq 04-Aug-19 11:27 AM Plus it helps to stay below the legal limit ;P 04-Aug-19 11:28 AM no Idea what the legal limit is at your place 04-Aug-19 11:28 AM Extremely strict, but I have workarounds to let me have my calibration sources in peace 04-Aug-19 11:30 AM too bad, everyone should have GBq sources at home! 04-Aug-19 11:30 AM @Ouais yeah energy and pressure, but other factors if talking about beam transport 04-Aug-19 11:30 AM brb, gotta do some housework.... 04-Aug-19 11:32 AM Actually have to rely on some very unique transport mechanisms for this beam, standard accelerator transport doesn't work with these beams 04-Aug-19 11:34 AM sounds spicy 04-Aug-19 11:34 AM Wouldn't your accelerator be the first DIY one in the world? @Applied_Ion 04-Aug-19 11:34 AM It gets pretty spicy when talking about kA level beams lol 04-Aug-19 11:35 AM I've never seen an actual linac built by a hobbyist 04-Aug-19 11:35 AM @Deleted User of this type, not of accelerators in general 04-Aug-19 11:35 AM It's not a linac, no RF 04-Aug-19 11:35 AM afaik linac doesn't explicitly require rf 04-Aug-19 11:35 AM just an ac that is also a lin :P 04-Aug-19 11:36 AM Usually in the accelerator world linac refers to linear rf 04-Aug-19 11:36 AM gotcha 04-Aug-19 11:36 AM Even straight dc electrostatic are still in their own class of electrostatic lol 04-Aug-19 11:37 AM will your accelerator be putting the beam through the atmosphere? 04-Aug-19 11:39 AM I could if running at peak energy and using a thin enough window, but I won't really need to for all the beamlines I have planned. Beam will be fully contained, but can do a huge amount of experiments with it 04-Aug-19 11:39 AM Beamline will change though 04-Aug-19 11:39 AM That is very cool 04-Aug-19 11:39 AM And I'll show others how to make this type 04-Aug-19 11:39 AM One day, if I succeed with a DIY x-ray tube, I want to try mastering making beryllium or diamond windows 04-Aug-19 11:40 AM Should be able to convert standard 6" conflat to the same power class, though in theory it can scale much smaller. Bigger is easier but cost goes up, but the accelerator itself is stupid simple 04-Aug-19 11:40 AM You could definitely do some nasty x rays with this lol 04-Aug-19 11:41 AM except in your case it's an ugly side effect 04-Aug-19 11:41 AM Actually, even high speed xrays for hydrodynamic studies 04-Aug-19 11:41 AM It depends 04-Aug-19 11:41 AM One beamline is to optimize xray yields 04-Aug-19 11:41 AM But generally I want to keep it down 04-Aug-19 11:42 AM focus the beam below 10 microns and start competing with Yxlon, Kevex, and Hamamatsu :P 04-Aug-19 11:42 AM I might get a continuously pumped 160kV 3mA 6um tube for repair soon 04-Aug-19 11:42 AM Yeah, my primary mode beam is like 8 cm diameter lol 04-Aug-19 11:43 AM that'd make a bit of an uh 04-Aug-19 11:43 AM how do I call it 04-Aug-19 11:43 AM "soft" spot 04-Aug-19 11:43 AM :P 04-Aug-19 11:43 AM but put 20kW through it and you're set to image... airliners, or something? 04-Aug-19 11:45 AM Peak power would be several hundred MW, average power almost nothing 04-Aug-19 11:46 AM Pulsed operation? 04-Aug-19 11:46 AM In that case you can't really compete with explosive emission cold cathode x-ray tubes 04-Aug-19 11:56 AM That is pulsed though 04-Aug-19 11:56 AM Well, You're saying peak is several hundred megawatts 04-Aug-19 11:56 AM I'm assuming your accelerator is pulsed 04-Aug-19 11:56 AM Yes 04-Aug-19 11:57 AM Yeah, the explosive tubes operate at several hundred kilowatts to megawatts 04-Aug-19 11:57 AM A couple sieverts per pulse 04-Aug-19 11:58 AM Small sealed tubes 04-Aug-19 11:58 AM My system would far outperform that 04-Aug-19 11:58 AM Look like light bulbs 04-Aug-19 11:58 AM Yeah yours would 04-Aug-19 11:58 AM Just not in a small package 04-Aug-19 11:58 AM I'm not going small though lol 04-Aug-19 11:58 AM Have you seen metal jet x-ray systems? 04-Aug-19 11:58 AM Those things are fascinating 04-Aug-19 11:59 AM Relatively small, 6" conflat 04-Aug-19 11:59 AM Very little info online 04-Aug-19 11:59 AM Haven't heard of them befote 04-Aug-19 11:59 AM They use a jet of liquid metal as the target 04-Aug-19 11:59 AM Huge power outputs 04-Aug-19 11:59 AM https://www.excillum.com/technology/ 04-Aug-19 12:02 PM bumps the table and spills liters of liquid tungsten inside the tube 04-Aug-19 12:02 PM My guess is that those bellows hide a very chunky granite stand for exactly that reason 04-Aug-19 12:03 PM EUV lasers seem a bit similar 04-Aug-19 12:03 PM with molten tin droplets 04-Aug-19 12:04 PM Interesting for small spot size stuff, but I'm aiming for the highest peak power class accelerators. Need kA beams for many things 04-Aug-19 12:05 PM kA x-ray beams is scary 04-Aug-19 12:05 PM even just pulsed 04-Aug-19 12:06 PM Opens up a new level of physics 04-Aug-19 12:06 PM Lots of systems require such high intensity beams that would be impossible to drive otherwise 04-Aug-19 12:06 PM And it can be done quite cheap 04-Aug-19 12:09 PM voice chat? 04-Aug-19 12:10 PM finishing up lunch, will join soon 04-Aug-19 12:11 PM How do you define beam current for an x-ray beam? 04-Aug-19 12:13 PM current is just charge (which is effectively just # of elementary charges) per second, so I assume the analogous quantity would be photons per second 04-Aug-19 12:13 PM and probably there's just a convention that you talk about the current required to make the beam 04-Aug-19 12:14 PM Oh ok 04-Aug-19 12:16 PM @Moist Mayonnaise beam current is measured at the electrical side 04-Aug-19 12:16 PM you have x kV and x mA emitting from the cathode towards the target, that's your beam current 04-Aug-19 12:16 PM same as beam current in cern 04-Aug-19 12:16 PM just injection 04-Aug-19 12:16 PM It's the beam current of the thing producing the x-ray beam not the x-ray beam then? 04-Aug-19 12:16 PM yeah 04-Aug-19 12:17 PM Ah ok that makes more sense 04-Aug-19 12:17 PM the x-ray output is pretty easy to calculate given efficiencies, angles, focus, target material and depth, all that 04-Aug-19 12:17 PM not many variables to change it 04-Aug-19 12:17 PM but in general it's in the single digit percent range in terms of power 04-Aug-19 12:17 PM around 3-5% 04-Aug-19 12:24 PM actually it's kind of funny that coulombs and mol are fundamental SI units but there is no base unit for quantity of photons (candela is closest, but it's strangely enough weighted by the luminosity function, which is an approximation of the sensitivity of the human eye) 04-Aug-19 12:24 PM I guess you could talk about moles of photons though 04-Aug-19 01:23 PM Does anyone know of any vacuum shops in Europe(preferably Germany because DHL Paket) that have reasonably priced vacuum fittings? 04-Aug-19 01:23 PM I need some more or less exotic stuff for my chamber, like a KF50-KF16 cross, KF16 to CF16(1.33") adapter 04-Aug-19 01:23 PM KF50 mesh ring 04-Aug-19 01:23 PM I don't want to have to order all this stuff from a million shops in China and wait two months for it to get here 04-Aug-19 01:25 PM novotek are great 04-Aug-19 01:27 PM Ouch, the prices are more than double than the shop in Russia I'm looking at 04-Aug-19 01:27 PM :< 04-Aug-19 01:28 PM oh 04-Aug-19 01:28 PM link to the russian one? 04-Aug-19 01:29 PM http://evacuum.ru 04-Aug-19 04:28 PM Ordered more parts! 04-Aug-19 04:28 PM https://i.spirit.re/ZNZRj.png 04-Aug-19 04:28 PM Green is stuff I have, yellow is what's coming, red is what I'll be machining. 04-Aug-19 04:28 PM Getting there. Slowly. 04-Aug-19 04:28 PM Found a guy who undersold eBay by a few percent and provided some vacuum advice. 05-Aug-19 12:16 AM Are you dry pumping or? 05-Aug-19 12:39 AM Dry pumping? 05-Aug-19 12:39 AM That's not a diffpump, that's a turbo 05-Aug-19 12:39 AM Oil free 05-Aug-19 12:39 AM Yeah but the backing pump 05-Aug-19 12:40 AM No, the forepump is full of thoroughly wet oil 05-Aug-19 12:40 AM It's not a bad idea to have 2 fore line valves 05-Aug-19 12:40 AM oh yeah I have that handled, sort of 05-Aug-19 12:40 AM There's a pressure relief on the forepump adapter and the valve basically closes the system off 05-Aug-19 12:41 AM This is something a bit different than that 05-Aug-19 12:41 AM Once it's stopped I'll vent the forepump to air 05-Aug-19 12:41 AM And there will be a backstreaming filter before the valves, after the forepump 05-Aug-19 12:41 AM Not sure what kind yet, but I will machine one 05-Aug-19 12:42 AM Any part of the roughing line constantly exposed to the roughing pump, even with traps, will get coated with oil over time 05-Aug-19 12:43 AM How do I fix that? If it's even necessary, given the minuscule duty cycle it'll have 05-Aug-19 12:44 AM So your roughing line right where it connects to the chamber is going to get a lot of build up. By putting a second valve before your roughing line, then pumping line down first then chamber through line you minimize the hydrocarbon contamination in chamber 05-Aug-19 12:45 AM Good idea to get another valve in then 05-Aug-19 12:45 AM Can I get away with something as generic as a ball valve? 05-Aug-19 12:45 AM Not sure what kind of cheap plumbing will go down to roughing pressures without leaking like a sieve 05-Aug-19 12:46 AM Because you really get most your back streaming when you just are pumping on base pressure. It's also why you don't over pump with you roughing pump before going to high vav 05-Aug-19 12:46 AM Yeah I don't think so 05-Aug-19 12:46 AM Will I get less contamination if I ramp the forepump speed? It has a VFD on it 05-Aug-19 12:46 AM Ball valves are so many separate parts unlikely to be highish vac sealed 05-Aug-19 12:46 AM No. It's about pressure gradient 05-Aug-19 12:47 AM I guess I'll have to look for another valve 05-Aug-19 12:47 AM It's only really a big deal if youre system is super sensitive to contamination 05-Aug-19 12:47 AM Which I don't know if it is 05-Aug-19 12:47 AM Vacuum tubes and a very crappy SEM 05-Aug-19 12:47 AM That's the main application 05-Aug-19 12:48 AM Should probably be ok 05-Aug-19 12:48 AM Especially if not running 24/7 05-Aug-19 12:48 AM Not going to be chasing nanometers, "it magnifies" is a perfectly valid result for me 05-Aug-19 12:48 AM Just thought I would mention that trick 05-Aug-19 12:48 AM I will make a note of that 05-Aug-19 12:49 AM I know some folks in here are doing in vacuum optics and uhv stuff in which case this totally matters 05-Aug-19 12:49 AM Given my distinct lack of proper equipment and conflats, I don't think I'll be doing UHV any time soon... 05-Aug-19 12:50 AM (like crazy optics spec will cause laser to melt glass stuff) 05-Aug-19 12:50 AM Yeah, my stuff will be much more crude 05-Aug-19 12:50 AM Maybe a TEM first, because a TEM is inevitable when building a DIY SEM 05-Aug-19 12:50 AM (looking at the beam with a screen) 05-Aug-19 12:51 AM Well that's not quite tem 05-Aug-19 12:51 AM Maybe stm 05-Aug-19 12:51 AM An electron camera obscura :P 05-Aug-19 12:51 AM *stem 05-Aug-19 12:51 AM well it'll be just the beam first, no S in STEM 05-Aug-19 12:51 AM Tem image forming is optics is really different than any sem 05-Aug-19 12:52 AM yeah the beam is different 05-Aug-19 12:52 AM I might try putting a naked PMT into it and seeing if I can replicate the original SE detector 05-Aug-19 12:52 AM Rather than an E-T one 05-Aug-19 12:52 AM Can't find any ET-capable scintillators, and I only have some CsI:Tl scraps on hand 05-Aug-19 12:53 AM Oh et scintillator is easy 05-Aug-19 12:53 AM It's just p47 phosphor 05-Aug-19 12:53 AM I guess I could just scrape off the inside of a CRT 05-Aug-19 12:54 AM You can totally make your own 05-Aug-19 12:54 AM Or grab one for ~100$ 05-Aug-19 12:54 AM Y2SiO5 doped with Ce? 05-Aug-19 12:54 AM I can totally not make that at home 05-Aug-19 12:54 AM :P 05-Aug-19 12:54 AM Lol it works 05-Aug-19 12:55 AM If I can buy the actual scintillator, sure 05-Aug-19 12:55 AM Can't synthesize it 05-Aug-19 12:55 AM I meant get a vial of it 05-Aug-19 12:55 AM Yeah, I can't find any 05-Aug-19 12:55 AM But yeah I have scraped old phosphor in a pinch before 05-Aug-19 12:56 AM I'll grind up a bit of CsI:Tl to see if it works 05-Aug-19 12:56 AM in slow scan mode it should work 05-Aug-19 12:56 AM Yeah 05-Aug-19 12:56 AM Recovery is... not good 05-Aug-19 12:57 AM And yield is awful 05-Aug-19 12:57 AM Eh 05-Aug-19 12:57 AM Just throw massive amounts of beam current at it 05-Aug-19 12:57 AM Though the currents here are a lot higher than in actual dosimeters 05-Aug-19 12:58 AM http://www.agarscientific.com/scintillator-discs 05-Aug-19 12:58 AM These Plano ones are my favorite 05-Aug-19 12:58 AM Not awful but definitely not cheap either 05-Aug-19 12:59 AM Yeah these are basically the best p47 ones out there 05-Aug-19 12:59 AM Making the HV and light passthroughs will be the most difficult part of the ET detector 05-Aug-19 12:59 AM specifically sealing them 05-Aug-19 12:59 AM Light pass through is just acrylic tube and epoxy 05-Aug-19 12:59 AM If you have a lathe o-ring seal is easy 05-Aug-19 01:00 AM Yeah I do 05-Aug-19 01:00 AM Just do a compression wedge style seal 05-Aug-19 01:00 AM No critical dimensions and self correcting 05-Aug-19 01:01 AM Getting very far ahead here 05-Aug-19 01:01 AM First, -5 or -6 05-Aug-19 01:04 AM Anyways off to bed 05-Aug-19 01:04 AM Same here, haha 05-Aug-19 01:04 AM 11:04 AM here 05-Aug-19 01:04 AM Lots of scopes to deal with tomorrow 05-Aug-19 01:04 AM Fun times 05-Aug-19 01:04 AM Hopefully 05-Aug-19 01:05 AM Alright, see you later 05-Aug-19 04:54 AM Hy, is there any specific content scheduled during the voice chat period as yesterday or is it a free voice chat about vacuuming ? Just wondering 05-Aug-19 04:57 AM you can talk about whatever you want with whomever you want whenever you want 05-Aug-19 06:04 AM we talked about TV shows for a while yesterday 05-Aug-19 10:04 AM @Deleted User You like cables 05-Aug-19 10:04 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20190805_111042-F33E7.jpg 05-Aug-19 10:05 AM eye diagrams are mean and I don't deal with bit rates that high 05-Aug-19 10:12 AM I see eye diagrams a lot since i work in analog silicon validation 06-Aug-19 12:59 AM Joined the server. 06-Aug-19 01:00 AM Here's a vacuum dude from Moscow that I met recently 06-Aug-19 01:00 AM Still not entirely sure what he does, but he did sell cheap vacuum parts to me so I'm happy :P 06-Aug-19 02:01 PM @Applied_Ion did you buy your HPT-100 gauge new, what did it cost? Ebay shows one for $350 in bad calibration, $400 for one that was pulled from equipment (but no info on whether it was working well at that time) 06-Aug-19 02:07 PM Well, I got pretty lucky. I bought 2 working ones for 40 each which I proceeded to kill, then another 2 for maybe 200 each, one of which I again proceded to kill. The electronics are highly sensitive to arcs, and well, working on pulsed plasma thrusters, that kind of goes with the territory. I found that if I disconnect the electronics during testing from the sensor head, they are fine after. Only 3 gauges later... 06-Aug-19 02:07 PM Fortunately the gauge heads are fine, so I can just pop them on working electronics and recalibrate 06-Aug-19 02:15 PM By disconnect do you mean unplug power and rs485, or actually something inside the gauge housing? 06-Aug-19 02:26 PM Like not only power and rs485, but the full electronics module. It can be disconnected from the sensor head for bake out 06-Aug-19 02:33 PM Ahh, cool,good to know 06-Aug-19 02:33 PM I guess I'll keep my eyes open for a better price 06-Aug-19 02:33 PM I like the idea of a full scale gauge 06-Aug-19 02:33 PM I'm so new at this, I want as much info and least guesswork as possible 06-Aug-19 02:34 PM They are amazing gauges, just watch out if you are doing any pulsed or hv stuff thst can arc to your housing 06-Aug-19 02:42 PM @Applied_Ion if you have the dead gauges, I might want them to try repairing 06-Aug-19 02:42 PM I've always liked the idea of combined gauges, and I already wrote the drivers for the pfeiffer protocol 06-Aug-19 02:42 PM the PPT-100 is a joy to use compared to the IGM-400 06-Aug-19 03:11 PM Pheiffer vacuum protocol aint thatbad 06-Aug-19 03:11 PM Tho the defaults mentioned in manuals and reality don't always meet. 06-Aug-19 03:11 PM Tho the only pheiffer gauges I have used had analog output. 06-Aug-19 03:20 PM @Deleted User awesome! The pfeiffer protocol for the hpt-100 ended up being much easier to use than I first expected 06-Aug-19 03:20 PM I haven't written the full API for it 06-Aug-19 03:20 PM But I do calculate the checksum.... 06-Aug-19 03:21 PM @rfs the nice part about the non-analog output ones is that you get significantly more resolution since you aren't limited from 0 to 10 signal, it just outputs the value as a string which you can convert pretty easy 06-Aug-19 03:21 PM That's actually a bit false 06-Aug-19 03:21 PM You don't really get more than 1-3 significant digits 06-Aug-19 03:21 PM It does basically the same thing as digitizing 0-10 but internally and not at 0-10 06-Aug-19 03:21 PM And yes I know that it does output a whopping 4 digits, but 2 of them are generally useless(0) 06-Aug-19 03:21 PM But the digital protocol is much better and easier to use 06-Aug-19 03:23 PM Ah, makes sense, my bad. Not too good on the digital electronics front. 06-Aug-19 03:24 PM Yeah most of these gauges are rather low resolution or high noise 06-Aug-19 03:24 PM But when do you need more than 3 significant digits 06-Aug-19 03:24 PM Basically never 06-Aug-19 03:24 PM Yeah, especially since accuracy is fairly limited anyway 06-Aug-19 03:25 PM But yeah, it might be possible to repair your dead gauges 06-Aug-19 03:25 PM I bet it's the sampling part that's dead, since HPTs are rated to ~2kV inside the chamber 06-Aug-19 03:26 PM That would be fantastic, I only have 1 gauge left and like a bunch of dead electronics and mostly good heads 06-Aug-19 03:26 PM Send the dead stuff and 2-3 good heads 06-Aug-19 03:26 PM If I can repair them, I keep one gauge and head as payment ;) 06-Aug-19 03:26 PM If not, they're dead anyway, so no loss 06-Aug-19 03:26 PM The only issue is that I won't be able to calibrate them beyond making them not read garbage, since I don't have a good reference meter like a baratron 06-Aug-19 03:29 PM Yeah, sounds reasonable. I'll have to go back and check which are dead vs uncalibrated. Calibration is pretty easy for them. Just send a command at atmosphere, and a command when they are at 10^-5 torr. I can just recalibrate using my working gauge as needed initially 06-Aug-19 03:29 PM You also need to be at 1000 mbar I believe 06-Aug-19 03:29 PM Not just atmosphere 06-Aug-19 03:29 PM And getting to actual -5 torr is a lot harder than getting to where your other gauges read -5 torr 06-Aug-19 03:29 PM Unless you have a choir of gauges that all agree 06-Aug-19 03:31 PM Not sure, it's been a while since I checked the manual. But for starters, using a working gauge for reference is good enough 06-Aug-19 03:31 PM THe one's I have calibrated ware just cal'd at atmospheric pressure. 06-Aug-19 03:31 PM Quick question though - does the pirani part read? 06-Aug-19 03:31 PM I can check then against sone of my friends gauges as well 06-Aug-19 03:31 PM Or is it completely dead, with no comms? 06-Aug-19 03:31 PM Yeah, no comms I think 06-Aug-19 03:32 PM I just hope the CPU isn't dead 06-Aug-19 03:32 PM Getting the firmware out of one might be tricky, especially if pfeiffer had the fun idea of locking the flash 06-Aug-19 03:33 PM Oh yeah, the old fat analog pheiffers had no MCU in then, the new slim red one's do. 06-Aug-19 03:33 PM They do. 06-Aug-19 03:33 PM There should be some ancient pictures by me in #show-and-tell when I repaired some. 06-Aug-19 03:33 PM We're talking about the HPTs, which talk digitally 06-Aug-19 03:33 PM The white and red stripey ones 06-Aug-19 03:33 PM Ah yeah 06-Aug-19 03:33 PM Not the red digiline 06-Aug-19 03:34 PM Only dealt with the red slim one (has EFM32 from silabs as mcu, so quite frsh design) and fat ones that are just beige/white 06-Aug-19 03:34 PM The old fat ones are analog and use those funny connectors 06-Aug-19 03:34 PM Same as the new ones actually 06-Aug-19 03:34 PM The white and stripey ones use a regular DB9 and have RS232 and RS485 on there 06-Aug-19 03:34 PM I prefer RS485 because it's easier to make work with voltages and it's a lot more resilient to noise 06-Aug-19 03:40 PM Funny connector is Molex mPm series 6-pin 06-Aug-19 03:40 PM But other vendors exist 06-Aug-19 03:40 PM DIN valve connectors 06-Aug-19 03:40 PM huh 06-Aug-19 03:40 PM I knew they looked familiar! 06-Aug-19 03:42 PM Yea the Pheiffer control port for RS485 stuff is the usual M12 industrial standard connector, I think. We made custom cabling harnesses for the pumps 06-Aug-19 03:42 PM Speaking of pumps 06-Aug-19 03:42 PM I found a ton of cheap-ish Leybold pumps that seem to be mass spectrometer surplus 06-Aug-19 03:42 PM IIRC pheiffer wanted 230-250eur/pcs for the cables. 06-Aug-19 03:42 PM But they have no flanges 06-Aug-19 07:11 PM Viewport shutter 06-Aug-19 07:11 PM Diy approach 06-Aug-19 07:11 PM Anyone says magnets? 06-Aug-19 07:12 PM bellows passthrough or magnets 06-Aug-19 07:12 PM though bellows passthroughs are also magnet-based 07-Aug-19 12:52 AM By the way there is free Pfeiffer soft , "turbo viewer", it also can deal with HPT100 and PPT100. You only need usb-rs485 adapter and a power for gauge, But it's not always handful to use PC near the system. 07-Aug-19 12:52 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_2619-04C18.JPG 07-Aug-19 12:52 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_2620-29FA7.JPG 07-Aug-19 04:22 AM Oh,hmm, I guess i need to start a table of gauges... Turns out I already have an MKS 901p which can go from atmospheric to 10^-5 torr 07-Aug-19 08:20 AM Wow. I just looked at the price for those 901 sensors and gauges. I should go into the vacuum gauge business. Our company already makes water pressure sensors and I have all of the parts, materials, and designs from a company in the 50’s and 60’s that made thermocouple gauges and ion gauges. 07-Aug-19 08:20 AM Would be a natural progression. 07-Aug-19 08:20 AM The question is, how much of a market is there for this stuff. Is it a growing or shrinking market for vacuum systems. 07-Aug-19 09:09 AM Thermocouple gauges are a dime a dozen 07-Aug-19 09:09 AM Ion gauges need to be reliable and precise 07-Aug-19 09:55 AM You don't really need proprietary software to read a pfeiffer protocol gauge 07-Aug-19 09:55 AM Here's 6 lines of python that do the same thing: https://gist.github.com/Spirit532/29513731ed9e9b71df8ead4858c31006 08-Aug-19 11:37 AM @Moist Mayonnaise what's this 08-Aug-19 11:38 AM @iSpy I don't know 08-Aug-19 11:39 AM @Moist Mayonnaise who does know? 08-Aug-19 11:40 AM @iSpy Spirit knows 08-Aug-19 11:40 AM @Deleted User what's this 08-Aug-19 11:41 AM What? 08-Aug-19 01:55 PM @Moist Mayonnaise he doesnt know 08-Aug-19 01:59 PM @iSpy he does know 08-Aug-19 03:25 PM Hi! 08-Aug-19 03:35 PM Hi there! 10-Aug-19 07:28 AM Joined the server. 10-Aug-19 07:28 AM Welcome! 10-Aug-19 07:29 AM Hi! 10-Aug-19 04:10 PM @obtusecrimes are you on Twitter as well? 10-Aug-19 04:38 PM w00t, update on my big package, is now in SD 10-Aug-19 04:38 PM the floor for that machine is now covered in bits of this old machine I've been working on.. just scrubbing off some of the grime.. so much more to do on it though 10-Aug-19 04:38 PM I think I need a new 40gal tub for soaking/cleaning parts 10-Aug-19 04:45 PM bolt a couple 300W ultrasonic transducers to the bottom 10-Aug-19 04:45 PM and a few kettle heaters 10-Aug-19 04:45 PM hah, I have some ultrasonic homogenizers.. 10-Aug-19 04:45 PM I can target 10-Aug-19 04:45 PM we use baths at school and it's so... meh 10-Aug-19 04:45 PM homogenize the gears into powder, pour back into mold, let it set 10-Aug-19 04:46 PM yeah, so many watts it can pitt metal 10-Aug-19 04:46 PM that sounds like a consumable-less alternative to sandblasting 10-Aug-19 04:46 PM and now I want a homogenizer 10-Aug-19 04:46 PM but I have a lathe! 10-Aug-19 04:46 PM I have 3 transducers and two electronic unit parts 10-Aug-19 04:46 PM so I can just wing it and then tune the transducer to the thingy in post 10-Aug-19 04:46 PM 250 and 400watt iirc 10-Aug-19 04:46 PM I did some work with my lathe yesterday, still plenty more to do, but I thikn what I am doing should really be done with a boring head on the mill 10-Aug-19 04:47 PM or I could go all FEA on it and math out all the resonances in CAD before I machine a horn 10-Aug-19 04:47 PM you should 10-Aug-19 04:47 PM I should but will I? 10-Aug-19 04:47 PM that's the question 10-Aug-19 04:48 PM the only reason you should not is to expediate experimentation.. but the stability of the systemw ill be sorely lacking if you miss the harmonics 10-Aug-19 04:48 PM anyways, right now it's just scotch brite 'sponges' and 00 steel wool 10-Aug-19 04:48 PM I will be repainting this machine, too... still figuring out colours 10-Aug-19 04:48 PM I want it to be more... fun 10-Aug-19 04:50 PM pure white 10-Aug-19 04:50 PM and lately the RAL6011 has gotten boring 10-Aug-19 04:50 PM or vibrant pink 10-Aug-19 04:51 PM yeah, I was thinking white, with maybe hte moveable segments as a bright blue, red, and green 10-Aug-19 04:51 PM we need more white in the machining industry 10-Aug-19 04:52 PM white: https://www.smsa.ch/en/Products/Conventional-turning/70-CF-Conventional-high-precision-lathes.html 10-Aug-19 04:52 PM d'awww 10-Aug-19 04:52 PM wait 10-Aug-19 04:52 PM HOLD ON, NOT D'AWW 10-Aug-19 04:52 PM their picture sucks, lol 10-Aug-19 04:52 PM MY MINI LATHE IS A SCHAUBLIN CLONE! 10-Aug-19 04:52 PM https://spirit.re/lathe.jpg 10-Aug-19 04:52 PM tell me they're not nearly identical 10-Aug-19 04:52 PM what is your center height? 70mm ? 10-Aug-19 04:53 PM a little taller 10-Aug-19 04:53 PM .. 102? 10-Aug-19 04:53 PM 80mm chuck 10-Aug-19 04:53 PM I didnt ask about the chuck, I asked about center height 10-Aug-19 04:53 PM yeah I don't know the center height 10-Aug-19 04:53 PM let me see 10-Aug-19 04:53 PM fromt he bed to the center of the chuck 10-Aug-19 04:53 PM that's how Schaublin designated their models 10-Aug-19 04:54 PM "maximum disk type work: 125mm" "maximum shaft type work above the carriage: 75mm" 10-Aug-19 04:54 PM it may not be a 1:! clone, but there are slight similarity.. it appears more like a mini lathe to me 10-Aug-19 04:54 PM not a direct clone 10-Aug-19 04:54 PM made from 1971 to 1976 in Armenia 10-Aug-19 04:55 PM hrmm 10-Aug-19 04:55 PM so a Soviet clone 10-Aug-19 04:55 PM ahh 10-Aug-19 04:55 PM but even the slant is the same 10-Aug-19 04:55 PM TIL 10-Aug-19 04:55 PM prismatic geometry 10-Aug-19 04:55 PM I'll need to rescrape all ofmy ways 10-Aug-19 04:55 PM not too necessary, but I want to only do this kind of overhaul once 10-Aug-19 04:55 PM this new machine came from the Elgin watch factory 10-Aug-19 04:56 PM the good and bad thing about these lathes is that they don't have sliding carriages 10-Aug-19 04:56 PM so the ways remain perfect forever 10-Aug-19 04:56 PM scraping marks from the factory 10-Aug-19 04:56 PM ohh.. yeah, most watchmakers lathes are like that 10-Aug-19 04:56 PM you still have ways on the cross slide though 10-Aug-19 04:56 PM just not really on the bed 10-Aug-19 04:56 PM the sliding is never under load/friction 10-Aug-19 04:56 PM anywho, yeah 10-Aug-19 04:57 PM the cross slides wear yeah 10-Aug-19 04:58 PM two of my 'ways' on this new/old machine are clampable/non adjsutable during operation 10-Aug-19 04:58 PM that house the [removeable] spindles 10-Aug-19 04:59 PM that's interesting 10-Aug-19 05:00 PM including those, there are 7 sliding parts.. which means 14...*3 to 6, mating surfaces I need to work on.. 10-Aug-19 05:00 PM sounds like a relatively small surface area though 10-Aug-19 05:00 PM two parts on each, but a few surfaces of each 10-Aug-19 05:00 PM yeah, no bigger than two hands 10-Aug-19 05:00 PM (decent measurement?) 10-Aug-19 05:01 PM applies when there's no banana for scale 10-Aug-19 05:01 PM pisan zapra 10-Aug-19 05:01 PM (in Malay, the time it takes to eat one banana) 10-Aug-19 05:02 PM that's one odd time measure 10-Aug-19 05:02 PM there is also one for the distance a raindeer can go before needing to relieve itself 10-Aug-19 05:02 PM all in a 'Lost in Translation' book I have 10-Aug-19 05:02 PM "it's about 3 reindeer pees away" 10-Aug-19 05:03 PM words/phrases that never really needed to be translated 10-Aug-19 05:03 PM I'm getting hungry.. dinner suggestions? 10-Aug-19 05:05 PM pizza 10-Aug-19 05:05 PM hrmm 10-Aug-19 05:05 PM maybe tomorrow 10-Aug-19 06:18 PM Am I being fooled by bad sound recording on youtube videos, or do very quiet rotary vane pumps exist? 10-Aug-19 06:18 PM Mine gives off a nice solid hum even when it's not loaded(plugged and pumped down) 10-Aug-19 06:19 PM mine hums, but not too loud 10-Aug-19 06:47 PM of course it hums, the fan on the motor usually does make some noise 10-Aug-19 06:49 PM mine is a lot louder than just the fan 10-Aug-19 06:49 PM which I've 3D printed and optimized for airflow 11-Aug-19 10:15 PM I'm thinking about designing a low cost universal custom turbomolecular pump controller 11-Aug-19 10:15 PM Is there a market for it? Do people here have closets full of turbos without controllers? 11-Aug-19 10:25 PM Controllers for them are hardly complicated, and most people here know their way around the basics of electronics, but still 12-Aug-19 09:21 AM I'd guess there's a market, not sure how big 12-Aug-19 09:21 AM I'd suggest using a differential signalling/communication protocol though, ethernet or rs485 12-Aug-19 10:12 AM I'm already going to be using rs485 for talking to my vacuum station controller 12-Aug-19 10:56 AM I like how robust and simple it is 12-Aug-19 01:56 PM I would be happy with one that had plain wiring terminals rather than some impossible to find and expensive when you do cable. And would it kill them to put a plain old on/off switch on it in conjunction with the remote control? 12-Aug-19 01:56 PM Btw. Here are the remains of a “guaranteed not dead, removed from working environment” EXT70 upon passing a few thousand RPM the infamous sound occurred, then the sound of bearing going dead, and screeching to a halt, and the sound of my money being flushed down the drain. Never again! Hahahaha 12-Aug-19 01:56 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-C937B.jpg 12-Aug-19 01:56 PM It’s now a testament of check eBay seller reviews before bidding. 12-Aug-19 02:04 PM yeah, it'll have wire terminals 12-Aug-19 02:04 PM poor turbo :( 12-Aug-19 02:04 PM I see the syringe of what-used-to-be-oil :P 12-Aug-19 02:04 PM I worry that my turbo will seize as well, though I did drive it up to ~3000 rpm in air 12-Aug-19 02:04 PM and the oil wick cartridge seems very wet still 12-Aug-19 02:24 PM I'm thinking of making two modules and one brain 12-Aug-19 02:24 PM one for 2 or 4 phase motors 12-Aug-19 02:24 PM and another for 3 phase motors 12-Aug-19 02:24 PM since they're driven differently 12-Aug-19 02:30 PM eBay ussually allows you to return stuff like that so long as the seller didn't list it for parts or as is basically 12-Aug-19 02:30 PM generally eBay will force the seller to refund you if you have a problem and return it 12-Aug-19 02:30 PM that is so long as its been within a reasonable amount of time since you got it 12-Aug-19 02:38 PM making a desk fan out of the turbo blades is also a nice idea 12-Aug-19 02:38 PM quiet and perfectly balanced! :P 12-Aug-19 03:09 PM lol 12-Aug-19 07:12 PM Ooo, grinder says it arrived in WA.. again 12-Aug-19 07:12 PM this time hopefully with the mahcine, not just papaerwork 12-Aug-19 07:12 PM I should clean up the pieces of the other tiny grinder (radius dresser) 13-Aug-19 02:31 PM @AdamMcCombs busy with trade shows, still? Got the call to schedule a delivery 13-Aug-19 02:31 PM You gave me plenty of options / ideas to make it work 13-Aug-19 02:31 PM But, extra hands are always nice 13-Aug-19 09:22 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_2435-F58F2.JPG 13-Aug-19 09:22 PM I'm making blue juice :) 13-Aug-19 10:02 PM That was quick 13-Aug-19 10:02 PM If you get a boiling equilibrium, you can actually fractionally distill oxygen by just letting the rest evaporate 13-Aug-19 10:02 PM Extremely inefficient, but requires pretty much no effort to get clean LOx 13-Aug-19 10:22 PM I assume you mean using LN2? This was making LOx directly 13-Aug-19 10:22 PM I had a canister of Oxygen I had nothing better to do with 13-Aug-19 10:22 PM so I had that flowing into it while it was running. 13-Aug-19 10:22 PM Looks like it took about 2 hours to make 1/3rd of a cup of the stuff 13-Aug-19 10:22 PM not too bad considering it had to take about 30 minutes to start to produce ANYTHING at all 13-Aug-19 10:22 PM https://pbs.twimg.com/media/EB5_-5kXYAAkstH?format=jpg 14-Aug-19 12:16 AM Congrats @Conmega ! 14-Aug-19 12:16 AM looks like I've started something... again 14-Aug-19 02:05 AM moin 14-Aug-19 02:06 AM moin! 14-Aug-19 02:08 AM looks cold 14-Aug-19 02:08 AM the oxygen 14-Aug-19 02:09 AM so blue 14-Aug-19 02:09 AM so... fire Hazard 14-Aug-19 02:10 AM yeah 14-Aug-19 02:10 AM p...put your stick in it 14-Aug-19 02:11 AM until it goes blue? 14-Aug-19 02:11 AM so blue 14-Aug-19 02:11 AM with a vacuum pump he could make oxygen ice cubes 14-Aug-19 02:11 AM tried it once for building a hybrid engine with solid oxidizer 14-Aug-19 02:11 AM just kidding 14-Aug-19 02:15 AM haha, that would be great 14-Aug-19 02:15 AM inverse hybrid rocket 14-Aug-19 02:15 AM burning gas in solid oxygen 14-Aug-19 02:18 AM or a powder mixture 14-Aug-19 02:18 AM oxygen powder mixed with hydrogen powder 14-Aug-19 02:32 AM that's a high explosive 14-Aug-19 08:31 AM haha jeez you guys 14-Aug-19 08:31 AM Also thanks @GigaSquirrel ! 14-Aug-19 09:37 AM Hrm thought my cryocooler had two stages... Suppose not! 14-Aug-19 09:37 AM https://www.cryomech.com/products/pt60/ 14-Aug-19 09:37 AM https://www.cryomech.com/wp-content/uploads/2018/11/PT60.jpg 14-Aug-19 09:37 AM Sure looks like its just a single stage 14-Aug-19 09:37 AM which is fine for what I am using it for here, but I wonder what the other copper bits inside are for then... Maybe just extra sinking to cool the air in its original application, or maybe something else... 14-Aug-19 09:49 AM if it was two stages they should be in series 14-Aug-19 09:49 AM waht does it sound like when working? 14-Aug-19 10:04 AM Sounds like an MRI machine running, you get that pst-pst-pst-pst pumping noise 14-Aug-19 10:04 AM hmmm 14-Aug-19 10:04 AM I guess it's just pulsing slowly 14-Aug-19 10:05 AM Also I know it would be in series, I dunno if you saw my photos but there is what appears to be a second stage? 14-Aug-19 10:05 AM the thingy with two pipes running up into the valve section? 14-Aug-19 10:05 AM https://media.discordapp.net/attachments/513120662756524044/611010620384346122/DSC_2424.JPG 14-Aug-19 10:05 AM I thought that was the body where the gas to be cooled flows through 14-Aug-19 10:05 AM No so thats down at the bottom of the frame in that photo 14-Aug-19 10:05 AM oh 14-Aug-19 10:06 AM this is another copper bit that extends past that into this SS tube 14-Aug-19 10:06 AM huh 14-Aug-19 10:06 AM no idea tbh 14-Aug-19 10:06 AM https://core.ac.uk/download/pdf/81824226.pdf 14-Aug-19 10:06 AM https://images-ext-2.discordapp.net/external/LqxcfJRLTeUaOVlAnnzlA0Wng6XdXeW_KFGtferai3c/https/i.imgur.com/B9pqVB1.jpg 14-Aug-19 10:06 AM this is my standard reference when it comes to cryocoolers 14-Aug-19 10:06 AM Because remember it looks like that not hacksawed up 14-Aug-19 10:06 AM Also the one video I took had audio if you want to hear it 14-Aug-19 10:07 AM yeah I remember 14-Aug-19 10:07 AM https://imgur.com/Wi4rr1l 14-Aug-19 10:08 AM yeah no idea 14-Aug-19 10:08 AM I may have to try and cut more of the tube off around that 14-Aug-19 10:08 AM to see whats going on there 14-Aug-19 10:08 AM if its a second stage neat, if its just a copper block to help spread the cold out for the air to flow over when it was just making air cold then I may have to see about removing some of it. 14-Aug-19 10:11 AM you mean if it was a second stage 14-Aug-19 10:12 AM What? lol 14-Aug-19 10:12 AM Also I am pretty sure its not... I can't find anything from Cryomech suggesting it would ever be 14-Aug-19 10:13 AM didn't you say something about hacksawing it open? 14-Aug-19 10:13 AM I did open up the end of the SS canister, which is just surrounding the cold end. 14-Aug-19 10:13 AM But I mean cutting further back on the SS tube, probably where its brazed to the copper to see what all it is in there attached to the end 14-Aug-19 10:13 AM I assume just copper sinking to spread the effect out and allow it to cool the N2 that was flowing through this better. 14-Aug-19 10:13 AM It doesn't matter much to have it on there really anyway, because this will be sitting down in a dewer at some point. 14-Aug-19 10:15 AM right 14-Aug-19 10:15 AM I just cut the tip off first to ensure I didn't cut into anything sensitive before 14-Aug-19 10:15 AM I thought the cylinder was already part of the possible second stage 14-Aug-19 10:15 AM Oh no no haha 14-Aug-19 10:15 AM Its just a gas flow chamber 14-Aug-19 10:15 AM the two thin SS tubes are an in and out gas flow 14-Aug-19 10:15 AM but now it sounds like it's just a heat spreader, because you need quite the surface to get rid of 60W 14-Aug-19 10:15 AM the conflat sealing around it was simply for insulation. 14-Aug-19 10:15 AM yup and to cool N2 to -196C out the tip of a spray nozzle 4 ft away 14-Aug-19 10:15 AM even if the entire path is insulated with vacuum... 14-Aug-19 10:15 AM still need to get the air a bit cooler than that :P 14-Aug-19 10:15 AM But yea this thing churns out liquid oxygen pretty quick, I have some used dessicant bags I need to dry out then build up an air compressor/drier and set it up so I can make liquid air 14-Aug-19 10:15 AM I will get an oxygen concentrator at some point to get an oxygen and or nitrogen source 14-Aug-19 10:18 AM we did some calculations 14-Aug-19 10:18 AM Put out like 4oz? of LOx in like 90 minutes with poor insulation lol 14-Aug-19 10:18 AM 100g of LN2 per hour is ~2.2W, assuming you use pure nitrogen at 300k 14-Aug-19 10:18 AM now just imagine what you can do with 10, 20 or even 60 watts 14-Aug-19 10:19 AM Dang yea hahaha 14-Aug-19 10:19 AM I'll have to get a big dewer :) 14-Aug-19 10:19 AM Man then I can try overclocking on some old motherboards and CPUs with LN2, something I've always wanted to try for the luls 14-Aug-19 10:20 AM I'm just imagining a constant stream of LN2 dripping into your dewar 14-Aug-19 10:20 AM https://thumbs.gfycat.com/MiniatureAmusingImperatorangel-size_restricted.gif 14-Aug-19 10:22 AM I would LOVE to get that on video... 14-Aug-19 10:22 AM I'll have to get a clear glass dewer just temporarily to get video... 14-Aug-19 10:22 AM that would be SO good 14-Aug-19 10:22 AM that would be really impressive 14-Aug-19 10:22 AM Because I always see people making it but I don't think I've personally seen video of the liquid forming 14-Aug-19 10:23 AM looks just like water condensing 14-Aug-19 10:23 AM only way less surface tension 14-Aug-19 10:25 AM yea 14-Aug-19 10:25 AM I just need to find a good dewer now... 14-Aug-19 10:25 AM I really would like to find something with a reasonable insulation to it... I know some of them aren't quite as good as others 14-Aug-19 10:26 AM while I don't get a coldhead or compressor as easily as you I at least have lots of dewars 14-Aug-19 10:26 AM most people just forget pumping their dewars every couple of years 14-Aug-19 10:27 AM Uhm most dewers I see are sealed 14-Aug-19 10:27 AM Hgr has dewars 14-Aug-19 10:27 AM the big storage ones usually aren't 14-Aug-19 10:28 AM Wanna send some of your surplus dewars this way? :P 14-Aug-19 10:28 AM Ah yea I'd love one of those big storage ones that actually seal and just vent every now and then. 14-Aug-19 10:28 AM There are a few that roll around work and I'm not sure why lol 14-Aug-19 10:28 AM https://www.ebay.com/itm/used-Pope-4L-Pyrex-Dewar-Lab-Flask-for-use-with-liquid-nitrogen/254307595635 14-Aug-19 10:29 AM wanna pay shipping for a cubic meter of padding? 14-Aug-19 10:29 AM Something like this might be nice for basic playing around with 14-Aug-19 10:30 AM I don't have a big dewar like that, but a 30l for short term storage and 18l for long term storage, with some sample holders for 200+ days 14-Aug-19 10:30 AM https://hgrinc.com/5-thoughts-before-buying-used-equipment/ 14-Aug-19 10:30 AM for my coldhead I'm building a dewar from glass fiber and some styrofoam from the hardware store 14-Aug-19 10:30 AM just an experiment 14-Aug-19 10:43 AM This one has an alarm on it https://hgrinc.com/5-thoughts-before-buying-used-equipment/ 14-Aug-19 10:43 AM Access from your Country was disabled by the administrator. 14-Aug-19 10:44 AM This is the last one I have saved https://hgrinc.com/5-thoughts-before-buying-used-equipment/ 14-Aug-19 10:44 AM Links are more for Connor than anything :P 14-Aug-19 10:44 AM Since he'll have the ability to pick up in person 14-Aug-19 10:46 AM oh sweet 14-Aug-19 11:02 AM @Treehouseman wth? all of those are just links to 5 thoughs before buying used equipment? 14-Aug-19 11:02 AM are you uh having an aneurysm over there? 14-Aug-19 11:03 AM Huh? 14-Aug-19 11:03 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-2A6CE.png 14-Aug-19 11:03 AM https://hgrinc.com/5-thoughts-before-buying-used-equipment/ 14-Aug-19 11:03 AM Thats all what they link to 14-Aug-19 11:03 AM are you mad? 14-Aug-19 11:04 AM lol 14-Aug-19 11:11 AM Give me a few 14-Aug-19 11:11 AM When I copied the link on the iPhone that's what it gave me 14-Aug-19 11:12 AM LOL what 14-Aug-19 11:12 AM Go get a real phone jeez 14-Aug-19 11:13 AM https://hgrinc.com/productDetail/Inspection/USED-TAYLOR-WHARTON-PORTABLE-NITROGEN-TANKDEWAR/02110818923/ https://hgrinc.com/productDetail/Inspection/USED-FORMA-SCIENTIFIC-NITROGEN-TANKDEWAR/02110818929/ https://hgrinc.com/productDetail/Inspection/USED-THERMOLYNE-NITROGEN-TANKDEWAR/02110818930/ 14-Aug-19 11:13 AM There 14-Aug-19 11:15 AM Eh they want ePay prices atm 14-Aug-19 11:22 AM Just wait for a sale day 14-Aug-19 11:22 AM But there's 3 nice good sized dewars 14-Aug-19 11:37 AM Yea, I have to also check out the surplus store near me sooner than later too 14-Aug-19 11:44 AM I got married on Sunday. In her vows, wife said I could have all the lab equipment I want in the basement. She's going to regret that. 14-Aug-19 11:49 AM LOL congrats! 14-Aug-19 12:00 PM Lolol 14-Aug-19 12:00 PM Maybe she's taking the till death do you part literally 14-Aug-19 12:00 PM The more equipment you have and play with, the higher the risks! 14-Aug-19 12:15 PM She's probably already taken out a life insurance policy on me 14-Aug-19 12:18 PM Do you blame her? 14-Aug-19 12:18 PM :P 14-Aug-19 04:50 PM You know how we were talking about atmospheric turbopumps don't exist? 14-Aug-19 04:50 PM HA, THEY DO! 14-Aug-19 04:50 PM https://www.idealvac.com/Edwards-EPX-500LE-EPX500LE--All-In-One-Atmosphere-To-HiVac-Dry-Vacuum-Pump-PN-A41953012/pp/P102980 14-Aug-19 04:50 PM The ultimate pressure is... disappointing 14-Aug-19 04:50 PM But it does vent to atmosphere and it is the way I thought it'd be made. 14-Aug-19 05:00 PM oh neat :o 14-Aug-19 05:16 PM https://www.ebay.com/itm/Edwards-EPX500L-Dry-Vacuum-Pump/332601904223 14-Aug-19 05:16 PM not that expensive either.... 14-Aug-19 05:16 PM though the power requirements are ridiculous 14-Aug-19 05:16 PM over 1kW at ultimate 14-Aug-19 05:48 PM Also, holy absolute hell 14-Aug-19 05:48 PM https://www.ebay.com/itm/233181980567 14-Aug-19 05:48 PM 2200l/s 14-Aug-19 05:48 PM You can stand inside this turbo 14-Aug-19 05:48 PM I can only imagine what would happen if the bearings seized in one of these at full speed... 14-Aug-19 11:40 PM ohjeez 14-Aug-19 11:40 PM do they ship to germany? 14-Aug-19 11:41 PM For enough money I'm sure they will 14-Aug-19 11:41 PM yeah ok 14-Aug-19 11:41 PM tmp 1k shipment over 9k 14-Aug-19 11:42 PM Probably over 100kg worth of stainless alone 14-Aug-19 11:42 PM But 1k is a bargain 14-Aug-19 11:42 PM Even with dead bearings 14-Aug-19 11:43 PM yeah man cool pumps though 14-Aug-19 11:44 PM And 27krpm is within the reach of a regular VFD 15-Aug-19 12:08 AM yep 15-Aug-19 12:08 AM normal high speed spindle stuff i guess 15-Aug-19 12:55 AM Except with a sloooooooooooooooooooooooooooooooooooooooooooooow ramp profile 15-Aug-19 05:48 AM could you give me some advice on how to "stick" a PCB-type substrate (which is compatible with UHV as the Rogers RO3003 model) but that I have to stick into an Integrated Circuit carrier like this one? what kind of glue or any other solution exist to achieve that goal in UHV constraint? (10^-12 torr) 15-Aug-19 05:48 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/CeramicSOIC-223F5.png 15-Aug-19 07:34 AM Sodium silicate or another silicate might be an option. 15-Aug-19 08:54 AM I've moved a turbo that big for Mason_Yu and man those massive turbos are spectacular. His was nice enough to have a built in controllers, so you just plugged an IEC in haha. 15-Aug-19 10:17 AM Here's the manual for my big turbopump. It has a variety of control interfaces including RS232, analog controls for PLCs, Profibus, and also a simple on/off button 15-Aug-19 10:17 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/T1600-Leybold-7A566.pdf 15-Aug-19 10:17 AM It's also just about light enough for one person to carry without a crane. Took me a while to figure out how to adapt the ISO200 flange though 15-Aug-19 10:17 AM Adaptors, tees and crosses for these huge flanges don't show up too often. 15-Aug-19 10:28 AM No they don't but some simple adapters aren't SUPER expensive new, especially just aluminum. 15-Aug-19 10:29 AM If it's ISO, you can also probably make them 15-Aug-19 10:47 AM What are you using something this huge for? 15-Aug-19 10:51 AM I have a differentially pumped ion drift tube for TOF. A pin-hole plate separates it from another chamber housing my plasma focus experiment, which is filled with a gas at up to several Torr of pressure. I need the pumping speed to keep the drift tube at a low pressure despite the large gas load from the pin hole 15-Aug-19 10:51 AM I had an Edwards EXT200 originally and had to use the absolute tiniest pin hole, but then I saw a good deal with this massive turbo 15-Aug-19 11:01 AM What does TOF refer to here? 15-Aug-19 11:01 AM I associate it with time of flight 15-Aug-19 11:01 AM Yeah, time of flight 15-Aug-19 11:02 AM So what's the experiment? Forgive my cluelessness 15-Aug-19 11:05 AM The experiment is a 15 kJ, 10 kV plasma focus. It is a class of pulsed linear z-pinch device that can generate quite intense ion and electron beams together with a short x-ray pulse. It is made up of concentric electrodes isolated from each other by an insulator, and the entire assembly is in a chamber of low pressure fill gas. 15-Aug-19 11:05 AM Gotcha 15-Aug-19 11:05 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20190815_123013-26D80.jpg 15-Aug-19 11:05 AM What's your application for it? 15-Aug-19 11:06 AM Electrode for reference, ignore the gage block 15-Aug-19 11:06 AM It is known as a good fusion neutron source if you fill the chamber with deuterium 15-Aug-19 11:06 AM For my set-up, theoretical predictions indicate 10^9 neutrons per shot may be possible 15-Aug-19 11:06 AM It is also a very, very short pulse. Almost all the neutrons are emitted in less than 100ns through the beam-on-target process. 15-Aug-19 11:08 AM I hope you're stocked up on neutron moderators, or plan on submerging this in a swimming pool :P 15-Aug-19 11:08 AM It's in a massive radiation shielded concrete chamber lol 15-Aug-19 11:08 AM That'll do 15-Aug-19 11:10 AM For now I am just looking for x-ray signals and a good pinch using argon as a fill gas. Need a cheap source of deuterium before I can generate any neutrons 15-Aug-19 11:11 AM PEM electrolysis of D2O is cheap 15-Aug-19 11:11 AM Yeah, maybe that's an option. I would prefer a free tank which is apparently just lying somewhere on the campus of my college... 15-Aug-19 11:12 AM I'm sure nobody would miss that if it suddenly vanishes... 15-Aug-19 11:12 AM I need to find it first. I just heard rumors that it's there somewhere 15-Aug-19 11:13 AM Security guard: "What are you doing!?" "Digging for deuterium. It's here somewhere." 15-Aug-19 11:13 AM lol 15-Aug-19 11:14 AM That's probably what will happen when I sneak into these buildings requiring card access 15-Aug-19 11:16 AM Some of the people on this server do some pretty crazy interesting stuff 15-Aug-19 11:16 AM I feel like I'm a vacuum weenie compared to most of you. 15-Aug-19 11:17 AM I'm just playing around with wasting my money in my free time on weird fascinating hardware. 15-Aug-19 11:17 AM I definitely feel like that 15-Aug-19 11:17 AM And using it in inappropriate ways. 15-Aug-19 11:17 AM But I'm in the same boat as Conmega 15-Aug-19 11:17 AM Wasting money strategically :P 15-Aug-19 11:18 AM Most people in here are physics nuts and I'm more of a physics n00b :P 15-Aug-19 11:18 AM I currently still have no degree in anything except being completely insane. 15-Aug-19 11:18 AM I know enough about physics to be safe and not kill myself by accident 15-Aug-19 11:18 AM Doesn't take a full understanding of anything to have fun and learn something though! 15-Aug-19 11:19 AM Having a basement helps 15-Aug-19 11:19 AM Being safe is important but I hope most of it is common sense and asking for help when you need it. 15-Aug-19 11:19 AM Can never ask too many questions. 15-Aug-19 11:19 AM You can only annoy some people with short tension spans :P 15-Aug-19 11:19 AM Until the people get annoyed with your questions 15-Aug-19 11:19 AM ha 15-Aug-19 11:19 AM But thats not your fault 15-Aug-19 11:19 AM still not wrong to ask too many questions 15-Aug-19 11:19 AM its just some questions could be better served by google 15-Aug-19 11:19 AM since thats what some of us do for you in some cases lol 15-Aug-19 11:20 AM I'm great at googling things until I can't figure it out 15-Aug-19 11:20 AM And then I ask questions 15-Aug-19 11:21 AM I just have an SEM that produces blurry images and some vacuum pumps. 15-Aug-19 11:21 AM I have no SEM, only some vacuum pumps 15-Aug-19 11:21 AM But I have an industrial robot 15-Aug-19 11:22 AM I have two SEMs and an industrial robot :) 15-Aug-19 11:22 AM My SEM also produces meh images and has flucuations atm 15-Aug-19 11:23 AM My industrial robot is 6 axis though :) 15-Aug-19 11:23 AM ah thats much nicer :P 15-Aug-19 11:23 AM SCARA is cool too, but I haven't found one yet 15-Aug-19 11:23 AM I want to make a 3D printer out of one 15-Aug-19 11:24 AM I used to have an industrial robot 15-Aug-19 11:24 AM lol I dunno if that is the best idea but I suppose doable 15-Aug-19 11:24 AM decent large printers are so cheap now 15-Aug-19 11:24 AM it's more of a cool points project 15-Aug-19 11:24 AM it would be like machining your own set of wrenches when you can just buy them 15-Aug-19 11:24 AM SCARAs aren't particularly useful at home 15-Aug-19 11:24 AM I get it, would be cool to do 15-Aug-19 11:24 AM but eh? 15-Aug-19 11:24 AM XD 15-Aug-19 11:24 AM Nah, I got mine because it says IBM 15-Aug-19 11:24 AM or a pick&place assembly machine 15-Aug-19 11:25 AM and I collect old computery stuff 15-Aug-19 11:25 AM did you get yours from IBM too? 15-Aug-19 11:25 AM or just an IBM bot 15-Aug-19 11:25 AM so the fact that it hooks to an old IBM PC for the control software it was cool 15-Aug-19 11:25 AM its an old IBM labeled scara 15-Aug-19 11:25 AM hook it to your z system 15-Aug-19 11:25 AM run LinuxCNC on it 15-Aug-19 11:25 AM ;P 15-Aug-19 11:25 AM its a sanyo sekie design though. 15-Aug-19 11:25 AM or however you spell their name 15-Aug-19 11:25 AM never can 15-Aug-19 11:25 AM sanyo seiki I'm guessing 15-Aug-19 11:25 AM lol the control software was designed for DOS so 15-Aug-19 11:25 AM yea that order of s,e,i,k,i 15-Aug-19 11:25 AM Dyslexia or something 15-Aug-19 11:27 AM not sure what seiki means in this case 15-Aug-19 11:27 AM it can be a name 15-Aug-19 11:27 AM "denki" is "electric" 15-Aug-19 11:27 AM ah dur 15-Aug-19 11:27 AM its sankyo seiki 15-Aug-19 11:27 AM Mine was a Staubli 15-Aug-19 11:27 AM I sold it to a guy who put a camera on it to filming TV commercials. 15-Aug-19 11:28 AM 6 axis, or scara? 15-Aug-19 11:28 AM *for filming tv commercials 15-Aug-19 11:28 AM 6 axis 15-Aug-19 11:28 AM https://i.imgur.com/4BEyhYY.jpg 15-Aug-19 11:28 AM Yeah, staublis are used in cinebot stuff 15-Aug-19 11:28 AM simple little thing 15-Aug-19 11:29 AM I'm actually working as a "lead engineer"(I got to pick the title!) for a company that is building a cinebot 15-Aug-19 11:29 AM Should have picked Senior VP of Engineering 15-Aug-19 11:29 AM We're using off the shelf robot though 15-Aug-19 11:29 AM I don't have an actual title yet 15-Aug-19 11:29 AM Not officially hired 15-Aug-19 11:29 AM But the company has some massive brands in the portfolio already 15-Aug-19 11:30 AM should have picked retired billionare 15-Aug-19 11:30 AM that looks great on the portfolio 15-Aug-19 11:30 AM lmao 15-Aug-19 11:30 AM heh 15-Aug-19 11:30 AM I wish 15-Aug-19 11:30 AM if I had a billion dollars I wouldn't retire though 15-Aug-19 11:30 AM I'd build the best not-quite-hackerspace 15-Aug-19 11:30 AM for me and friends 15-Aug-19 11:31 AM That seems to be what most of us would do... 15-Aug-19 11:34 AM Then I suggest we split the billion between us all 15-Aug-19 11:34 AM Should only be a few easy monthly payments of $12.99 15-Aug-19 11:39 AM lol yea then you realize everyone lives hundreds of miles away from eachother and it makes no sense to all invest in a central location in the middle of the pacific ocean... 15-Aug-19 11:43 AM Instead of Epstein's pedo-island, we'd have a hacker island 15-Aug-19 12:12 PM …somehow I was thinking of the Epstein-barr virus before I remembered the other E. 15-Aug-19 02:55 PM @Conmega ok look, if we have a billion dollars, I'm pretty sure relocation or a 24/7 private charter jet is not an issue :P 15-Aug-19 02:59 PM Right, but you ain't getting a billion dollars with 12 bucks a month any time soon 15-Aug-19 02:59 PM even with a thousand people 15-Aug-19 02:59 PM Also a billion dollars will go FAST with a goal like that 15-Aug-19 04:40 PM https://link.springer.com/article/10.1007/s11814-015-0232-6 15-Aug-19 04:40 PM Neat apparently Zeolite 5A is just fine for oxygen/nitrogen separation, kinda learning here what I can get for cheap for nitrogen/oxygen seperation for cheap at home via a PSA process. 15-Aug-19 04:40 PM Everyone just glosses over how they are doing this part or specifies hard to get stuff like CMS-200 or some places say Zeolite 13X 15-Aug-19 04:40 PM but yea... there appears to be many things that work, its just whats better/higher purity/etc 15-Aug-19 05:00 PM Delivery scheduled for Tuesday 15-Aug-19 05:00 PM they didnt have Liftgate service listed on their form... but I have a conversation with the seller where when he quoted me shipping, it was for liftgate+residential.. so it better be as such 15-Aug-19 05:00 PM (they were going to double check and get back to me) 15-Aug-19 05:00 PM oh wow, forecasted temp for tuesday is 81 F (27 C), unfphh 15-Aug-19 07:51 PM https://twitter.com/lukeweston/status/1162165226491408384 15-Aug-19 07:51 PM Oh jeez 15-Aug-19 08:12 PM It's not a bad solution if you have a budget of "yeah sure go ahead" 15-Aug-19 08:20 PM my question is why it's ISO100 when it goes directly to a reducer 16-Aug-19 06:48 AM 6 axis industrial bot as a camera dolly you mean? 16-Aug-19 06:48 AM ok yesterdays topic 16-Aug-19 09:25 AM moin! 16-Aug-19 09:30 AM moin 16-Aug-19 10:55 AM forgot how to vacuum... 16-Aug-19 11:04 AM I don't think that's how it's supposed to work 16-Aug-19 11:04 AM and on that note, I propose plumbers switch to KF fittings so they become cheap 16-Aug-19 12:23 PM i support that idea fuly! 16-Aug-19 12:23 PM pump went to 4mBar before, after flush with dishwashergranulate, water and 5%HCL its now @1.3 16-Aug-19 12:23 PM a full success 16-Aug-19 12:23 PM may even be good enough for a turbo, thatd be awesome 16-Aug-19 12:25 PM for the newer turbos - no problem 16-Aug-19 12:32 PM seems like the tv81 qualifies as a newer one 16-Aug-19 12:32 PM even though it lacks a drag stage 16-Aug-19 12:32 PM also sorry for filming with a potatoe, dont have the ood cam at hand 16-Aug-19 12:32 PM WUHOOO, finally oil free 16-Aug-19 12:36 PM most turbos will happily start at 10-20mbar 16-Aug-19 12:36 PM just a heavy gas load 16-Aug-19 12:38 PM i had problems with this one before trying to run it of membrane pumps 16-Aug-19 12:38 PM it seems to need below 5mBar or it will stall even without load 16-Aug-19 12:38 PM the big adapted tw290 would do it up to 10mBars but its pretty pointless tu run sich a giant on this sort of pump... 16-Aug-19 12:40 PM It's likely that the controller is very conservative 16-Aug-19 12:41 PM powerwise? 16-Aug-19 12:41 PM safety wise 16-Aug-19 12:41 PM if it doesn't see the correct speed/power curve, it kills it because of the gas load 16-Aug-19 12:42 PM aahh well, luckily this one is a pretty stupid one not sutting off pretty much ever 16-Aug-19 12:42 PM closed loop control can't really stall 16-Aug-19 12:42 PM it will spool up almost fully and draw around i think it was 100W 16-Aug-19 12:42 PM so it must be thinking something 16-Aug-19 12:42 PM maybe 80 16-Aug-19 12:42 PM oh, stall is the wrong word 16-Aug-19 12:42 PM i mean it just stops accelerating at almost full speed going into current limit 16-Aug-19 12:43 PM oh 16-Aug-19 12:43 PM and at that power this pump will heat up very fast 16-Aug-19 12:43 PM yeah that's a heavy gas load 16-Aug-19 12:44 PM well, now i have a working setup i can run without killing myself in my college dorm 16-Aug-19 12:44 PM no pipe out the window in winter any more 16-Aug-19 12:45 PM just wait until a loose chip falls into the blades 16-Aug-19 12:46 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/photo_2018-10-03_20-54-03-22C1E.jpg 16-Aug-19 12:46 PM ow 16-Aug-19 12:46 PM that was the one i took the bearings from 16-Aug-19 12:46 PM first stage was damaged, i balanced it by removing it entirely 16-Aug-19 12:46 PM worked fine to around 60k and then "stopped working" 16-Aug-19 12:47 PM a small accident 16-Aug-19 12:47 PM well, i expected it, mostly i was curious what would happen 16-Aug-19 12:47 PM I sliced my finger open on mine while I was stopping it 16-Aug-19 12:47 PM it was a fairly hard thwack 16-Aug-19 12:48 PM ouch 16-Aug-19 12:48 PM I hope I didn't break the pump 16-Aug-19 12:48 PM finger is fine now, just a tiny bit of nerve damage 16-Aug-19 12:48 PM but the pump I'm not sure about 16-Aug-19 12:48 PM priorities set right 16-Aug-19 12:48 PM I spent $300 on it 16-Aug-19 12:48 PM :< 16-Aug-19 12:49 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-FBC72.png 16-Aug-19 12:49 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-3721F.png 16-Aug-19 12:49 PM it hurts so much 16-Aug-19 12:49 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-1ADB4.png 16-Aug-19 12:50 PM why is it sitting on a scrap bin? 16-Aug-19 12:50 PM is it about to jump in? 16-Aug-19 12:50 PM i think it already did 16-Aug-19 12:50 PM while running or sth 16-Aug-19 12:50 PM I would've kept it 16-Aug-19 12:50 PM the pump 16-Aug-19 12:50 PM rip the rotor out, nice vacuum chamber with high vac feedthroughs 16-Aug-19 12:50 PM mh, thats true 16-Aug-19 12:50 PM we will see, i dont have a car so i couldnt save it yet 16-Aug-19 12:50 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-A32ED.png 16-Aug-19 12:50 PM though those ones will need rescue anyways 16-Aug-19 12:51 PM if you can rescue more turbos, I'll trade one of my not quite qualifying microfocus tubes for one :P 16-Aug-19 12:51 PM I have a turbo, but I'm already foreseeing that I will have a catastrophic vacuum loss accident some day 16-Aug-19 12:51 PM and they are not turbodrag... :( 16-Aug-19 12:52 PM if there wasnt the shipping problem... 16-Aug-19 12:52 PM not really a big deal 16-Aug-19 12:52 PM I mean unless you offer me an ISO200 1kl/s pump 16-Aug-19 12:52 PM xD 16-Aug-19 12:52 PM be careful what you whish for 16-Aug-19 12:53 PM see, that has the ability to actually injure someone if it seizes 16-Aug-19 12:53 PM a couple kilos spinning at many times supersonic 16-Aug-19 12:53 PM a grenade or two worth 16-Aug-19 12:55 PM That frightening prospect wakes me up at night... 16-Aug-19 12:55 PM im not sure if i have annoyed you guys with my turbine stuff already 16-Aug-19 12:55 PM https://www.youtube.com/watch?v=yqwIURdXBrk 16-Aug-19 12:56 PM the wrong kind of turbo! 16-Aug-19 12:56 PM thats 3kg rotor @ 50k with no containment 16-Aug-19 12:56 PM this one makes pressure! 16-Aug-19 12:56 PM is that a turbostarter? 16-Aug-19 12:56 PM jup 16-Aug-19 12:56 PM figured it from the exhaust 16-Aug-19 12:56 PM looks like it came from a mini APU 16-Aug-19 12:56 PM though it could also be a turboprop 16-Aug-19 12:57 PM sadly no apu but it will be a TP 16-Aug-19 12:57 PM well, an apu by itself is a suffocation generator 16-Aug-19 12:57 PM not much use without a big fighter jet 16-Aug-19 12:57 PM https://www.youtube.com/watch?v=V_pXlOkCQCg 16-Aug-19 12:58 PM oh it's a TS-21! 16-Aug-19 12:58 PM jup 16-Aug-19 12:58 PM they pop up in Russia from time to time 16-Aug-19 12:58 PM $300-3000 depending on luck 16-Aug-19 12:58 PM I believe they're only rated to operate for around 40 seconds at a time 16-Aug-19 12:58 PM and in certain german surplus shops from poland 16-Aug-19 12:58 PM i paid 1600 and it was as good as new 16-Aug-19 12:58 PM Igor Negoda built an actual engine from one 16-Aug-19 12:58 PM including pump 16-Aug-19 12:59 PM I'm sure you're subscribed 16-Aug-19 12:59 PM :P 16-Aug-19 12:59 PM bingo 16-Aug-19 12:59 PM though i was first 16-Aug-19 12:59 PM also a friend of mine 16-Aug-19 12:59 PM one sec 16-Aug-19 01:00 PM I wonder if it's possible to turn a turbopump into an axial turbojet... 16-Aug-19 01:00 PM mhhh crap, the video file is too big... 16-Aug-19 01:00 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/mouser1-318B5.jpg 16-Aug-19 01:01 PM what's it going to sit in? 16-Aug-19 01:01 PM an ultralight? 16-Aug-19 01:01 PM sadly nothing i guess 16-Aug-19 01:01 PM c'mon, you have a turbine 16-Aug-19 01:01 PM build an ultralight kit 16-Aug-19 01:01 PM might need to toss the seat, controls... and maybe the pilot 16-Aug-19 01:01 PM but it'll fly 16-Aug-19 01:02 PM i had an opportunity to get it to fly illegally but the guy killed himself last year doing stupid shit with one of his ultralights... 16-Aug-19 01:02 PM you can fly legally just as easily 16-Aug-19 01:02 PM not in germanoi 16-Aug-19 01:02 PM thought depending on where you live you might need a PPL 16-Aug-19 01:02 PM yeah you might need to get a PPL in Germany 16-Aug-19 01:02 PM nah, the licence is not the issue 16-Aug-19 01:02 PM but i have to have the machine certified 16-Aug-19 01:03 PM experimental doesn't require certification 16-Aug-19 01:03 PM experimental engines are actually somewhat easy, it requires 5h of full throttle running 16-Aug-19 01:03 PM it does here ^^ 16-Aug-19 01:03 PM experimental aircraft I mean 16-Aug-19 01:03 PM i still need to proove it will be allright in the aircraft i want to use 16-Aug-19 01:03 PM the resource of the ts21 is nowhere near 5h of full runtime 16-Aug-19 01:03 PM and the systems i have to change 16-Aug-19 01:03 PM oh, it will survive it, dont worry 16-Aug-19 01:03 PM my friend did his masters thesis on characterizing his TP build and it ran several houres on a test stand with no wear showing 16-Aug-19 01:05 PM at full throttle? 16-Aug-19 01:05 PM not all the time 16-Aug-19 01:05 PM but still 16-Aug-19 01:05 PM we have researched into it a lot and we are pretty confident it can do it 16-Aug-19 01:05 PM you'll need to mod it quite a bit 16-Aug-19 01:05 PM but it's possible 16-Aug-19 01:06 PM worst case the blades and stator have to be replaced by some modern alloy to stop creepage 16-Aug-19 01:06 PM all other parts are no issue 16-Aug-19 01:06 PM the compustion chamber is amazingly well designed and wont burn 16-Aug-19 01:06 PM its below 300°C almost all the way to the ngv 16-Aug-19 01:06 PM bearings are well oversized 16-Aug-19 01:06 PM and all other parts are cold 16-Aug-19 01:06 PM gearbox is also built like a tank 16-Aug-19 01:07 PM as soviet stuff tends to be 16-Aug-19 01:08 PM if this was built to purpose in europe, it'd be a miracle if you could run it for more than 3 minutes straight 16-Aug-19 01:08 PM there is almost no special tooling needed on this thing 16-Aug-19 01:08 PM pretty much everything is standard M4,5,6 threds 16-Aug-19 01:08 PM just stuff like the main shaft nuts are mildly special 16-Aug-19 01:08 PM also considering that this thing would not be changed regularly and would have the same tbo as the main engine it would see around 50h of runtime 16-Aug-19 01:08 PM and a shitton of cycles 16-Aug-19 01:08 PM sadly though it guzzles fuel and oil 16-Aug-19 01:08 PM efficiency is around 5% 16-Aug-19 01:08 PM and oil burn rate 2l/h 16-Aug-19 01:11 PM that's the cost of having a device that's meant to produce as much exhaust as possible 16-Aug-19 01:11 PM but not really power 16-Aug-19 01:12 PM and adrenaline 16-Aug-19 01:12 PM also fun fact 16-Aug-19 01:12 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-F43A1.png 16-Aug-19 01:12 PM thats an older version as starter on the NK12 engines used in the TU95 bombers 16-Aug-19 01:12 PM this engine was designed by german POW after ww2 16-Aug-19 01:12 PM the design is almost 70 years old now... 16-Aug-19 01:12 PM but btt: 16-Aug-19 01:12 PM im still interested in our microfocus tube, im just not sure if it will fit... 16-Aug-19 01:17 PM show me the "fit" it's supposed to be in 16-Aug-19 01:17 PM and I'll tell you 16-Aug-19 01:17 PM i have the same small thermosscientific head mikeselectricstuff tore down in 2012 16-Aug-19 01:17 PM I have a rough idea of the operating parameters, I just don't know the exact ones 16-Aug-19 01:18 PM sadly by some sad accident the tube is in shards 16-Aug-19 01:18 PM the filament drive is compatible with my BS6 16-Aug-19 01:18 PM and I got it to produce a slightly in focus image 16-Aug-19 01:18 PM by driving it the same way as my bs6 is supposed to be driven 16-Aug-19 01:18 PM https://i.spirit.re/AvL9L.png 16-Aug-19 01:18 PM I'm sure it can be focused down better 16-Aug-19 01:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-2B3C6.png 16-Aug-19 01:19 PM yours is magnetically focussed, isnt it? 16-Aug-19 01:19 PM electrostatically 16-Aug-19 01:19 PM and I'm pretty sure your thing can be repaired 16-Aug-19 01:19 PM mhh, tahts nice 16-Aug-19 01:19 PM well, the filament has seen oil 16-Aug-19 01:20 PM nothing a bit of pure acetone, then ethanol, can't fix 16-Aug-19 01:20 PM otherwise i would actually have asked a relaticve to reseal the thing 16-Aug-19 01:20 PM mh 16-Aug-19 01:20 PM I can't see where it broke though 16-Aug-19 01:20 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-AEDD8.png 16-Aug-19 01:20 PM oh 16-Aug-19 01:20 PM oh no :( 16-Aug-19 01:20 PM I doubt that can be fixed 16-Aug-19 01:20 PM ... 16-Aug-19 01:20 PM well, the glass metal transition is allright 16-Aug-19 01:21 PM unless you get into glass blowing 16-Aug-19 01:21 PM welllll 16-Aug-19 01:21 PM and even then... eugh 16-Aug-19 01:21 PM the other one isn't 16-Aug-19 01:21 PM plus your head is one of those funny ones with a side anode 16-Aug-19 01:21 PM i have a relative who was glasblower at a local university for 40y... 16-Aug-19 01:21 PM you can still use the hv psu though 16-Aug-19 01:21 PM and focusing 16-Aug-19 01:21 PM we have a resident glassblower here too 16-Aug-19 01:21 PM Charles 16-Aug-19 01:22 PM jup, psu works 16-Aug-19 01:22 PM well, i asked mike for his one 16-Aug-19 01:22 PM he told he would have a look if its still around and then never replied to my messages any more... 16-Aug-19 01:22 PM it would be a drop in replacement... 16-Aug-19 01:23 PM if everything goes great and I wasn't lied to, I might get a full continuously pumped Yxlon kit in September 16-Aug-19 01:23 PM described as "very leaky and won't go past 75kv" 16-Aug-19 01:24 PM sweeet 16-Aug-19 01:24 PM but knowing murphy, I won't hear from the dude ever again 16-Aug-19 01:24 PM and it'll get scrapped 16-Aug-19 01:24 PM :< 16-Aug-19 01:24 PM ... 16-Aug-19 01:26 PM I need to work on my cooling loop for the SEM, add in a new tap in point and valving. And add some flow control boards and stuff as @AdamMcCombs recommended. Looking into parts for that now. 16-Aug-19 01:26 PM no idea where I'm going to be putting the system if I get it though 16-Aug-19 01:26 PM the HV PSU alone is 110kg 16-Aug-19 01:26 PM and the vacuum/control cabinet is another 170kg 16-Aug-19 01:26 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/photo_2019-07-06_22-53-30-623DD.jpg 16-Aug-19 01:26 PM I see an XRF tube 16-Aug-19 01:26 PM I pray you never power it up 16-Aug-19 01:27 PM i have more devious plans than that 16-Aug-19 01:27 PM several sieverts per minute 16-Aug-19 01:27 PM also have two of them 16-Aug-19 01:27 PM jep 16-Aug-19 01:27 PM i plan on building a tube myself 16-Aug-19 01:27 PM for sterilization 16-Aug-19 01:27 PM that's my plan as well 16-Aug-19 01:27 PM that's not my plan 16-Aug-19 01:27 PM 20-30kV 16-Aug-19 01:27 PM several kW 16-Aug-19 01:28 PM sterilization of what? 16-Aug-19 01:28 PM bacteria growth media 16-Aug-19 01:28 PM if you want a very high power low voltage tube, get a soviet BSV tube 16-Aug-19 01:28 PM the water cooled ones 16-Aug-19 01:28 PM they have 4 beryllium output windows 16-Aug-19 01:28 PM i wanted to just take a KF40 chamber, add a window and throw in the rest of the stuff myself 16-Aug-19 01:29 PM it's a bit more involved than that 16-Aug-19 01:29 PM running a turbo with it 16-Aug-19 01:29 PM have a play around with an uh 16-Aug-19 01:29 PM obtained version of COMSOL Multiphysics 16-Aug-19 01:29 PM the electron optics modules 16-Aug-19 01:29 PM fairly intuitive to set up x-ray tube simulations 16-Aug-19 01:29 PM model the wehnelt, focusing optics, target 16-Aug-19 01:29 PM and then you can even do some heat dissipation analysis 16-Aug-19 01:29 PM the only downside(downside?) is that it uses actual physical models, so computation takes a hellishly long time 16-Aug-19 01:30 PM but is it really nessecary if im just after power? 16-Aug-19 01:30 PM yeah, it is 16-Aug-19 01:30 PM mh 16-Aug-19 01:31 PM you want to at least direct the bremsstrahlung where you need it 16-Aug-19 01:31 PM otherwise you'd be burning a bunch of x-rays in the shielding 16-Aug-19 01:31 PM wasted power 16-Aug-19 01:31 PM but you should be ok with just a filament and separate wehnelt focusing 16-Aug-19 01:31 PM no extra electrostatics required 16-Aug-19 01:32 PM jup 16-Aug-19 01:32 PM my plan was to first use a flourescent fim on the anode surface 16-Aug-19 01:32 PM a what 16-Aug-19 01:32 PM running it at limited power and getting it to hit in the rght spot 16-Aug-19 01:32 PM *film 16-Aug-19 01:33 PM oh for focus development 16-Aug-19 01:33 PM it's best to just simulate and then test 16-Aug-19 01:33 PM simulation is free, machining is not :P 16-Aug-19 01:33 PM though im better at machining so it will still cost less time 16-Aug-19 01:33 PM machining many parts over and over 16-Aug-19 01:34 PM well, you are right, i just dont like admitting that thinking first doing second actually is a valid approach 16-Aug-19 01:35 PM that's my usual process 16-Aug-19 01:35 PM but electron optics require just a bit more work 16-Aug-19 01:35 PM on the other hand considering the copper targets peaks could be in the right energy and the tubes i have are rated for CW operation... 16-Aug-19 01:35 PM i would have just build a whenelt cylinder and playing with the voltage i guess 16-Aug-19 01:36 PM try simulating a wehnelt 16-Aug-19 01:36 PM it broke my brain how actually finicky they are 16-Aug-19 01:37 PM oh 16-Aug-19 01:37 PM https://i.spirit.re/HVmPs.png 16-Aug-19 01:38 PM mhhhmmm 16-Aug-19 01:38 PM this is a failed simulation of the BS7-W tube 16-Aug-19 01:38 PM which is a "reverse" tube 16-Aug-19 01:38 PM filament on top, wehnelt, then a needle target, and the exit window is on the top 16-Aug-19 01:38 PM above the filament 16-Aug-19 01:38 PM but all the electrons went to the sides of the needle 16-Aug-19 01:38 PM none hit the tip :( 16-Aug-19 01:40 PM but doesnt that show getting the sim right is just as difficult and unreliable as a non professional? 16-Aug-19 01:41 PM that shows I'm incompetent in electron optics 16-Aug-19 01:41 PM i mean you may be able to get the sim to work but who knows if the real deal will not be much different if suh detaild play such a roll 16-Aug-19 01:41 PM xD 16-Aug-19 01:41 PM or just still learning... 16-Aug-19 01:41 PM a regular tube design is much easier 16-Aug-19 01:42 PM im happy to know the basics, not even thinking about actually designing something outside of trying 16-Aug-19 01:42 PM as in, filament -> wehnelt -> target ^ x-rays 16-Aug-19 01:42 PM jup 16-Aug-19 01:42 PM try it yourself 16-Aug-19 01:42 PM maybe with our combined efforts we can make a meh-o-focus x-ray tube! 16-Aug-19 01:43 PM maybe there is even someone around knowing this stuff better than us... 16-Aug-19 01:44 PM @Charles made x-ray tubes 16-Aug-19 01:44 PM and knows about glassblowing 16-Aug-19 01:44 PM i have a prof doing xray optics 16-Aug-19 01:44 PM x-ray optics is what happens after you don't fail at making x-rays in the first place 16-Aug-19 01:44 PM :D 16-Aug-19 01:44 PM just saying 16-Aug-19 01:44 PM there is people arount you can reach as a mortal 16-Aug-19 01:44 PM hes part of the zeiss (?) peope building the x ray stuff for making smaller semiconductors 16-Aug-19 01:46 PM EUV? 16-Aug-19 01:46 PM there's a huge cooperation consortium thing working on EUV photolithography 16-Aug-19 01:47 PM no, even shorter than euv 16-Aug-19 01:47 PM literal x ray 16-Aug-19 01:47 PM ehhhh 16-Aug-19 01:47 PM the lines are blurry 16-Aug-19 01:47 PM well ok 16-Aug-19 01:48 PM one moment you're UVing 16-Aug-19 01:48 PM the next it's x-rays 16-Aug-19 01:49 PM i would also say its all gaussian anyways but im pretty sure they are quite narrow 16-Aug-19 01:50 PM you can buy cheap hamamatsu photoionizers 16-Aug-19 01:50 PM they're ultra low voltage(I think around 2 to 9 kV) beryllium x-ray tubes 16-Aug-19 01:50 PM designed to remove static charges 16-Aug-19 01:53 PM mh, but such low power? 16-Aug-19 01:53 PM yeah, quite low 16-Aug-19 01:53 PM a couple watts 16-Aug-19 01:53 PM wonder if they could be used for extreme DIY photolithography 16-Aug-19 01:53 PM jup, in that case i can just use the 1.5kW tube and supply it with less oomph 16-Aug-19 01:53 PM mhm 16-Aug-19 01:53 PM well, i do have a microscope with purely reflective optics 16-Aug-19 01:53 PM not good enough for this wavelength but it will do everything tat will reflect off of Al 16-Aug-19 01:55 PM UV would work 16-Aug-19 01:57 PM jup 16-Aug-19 01:57 PM well, enough for today, need o go or Gbq will lynch me tomorrow if i miss the meeting 16-Aug-19 01:57 PM you work together? 16-Aug-19 01:58 PM hobby meetng 16-Aug-19 01:58 PM oh 16-Aug-19 01:58 PM heh 16-Aug-19 01:59 PM though sometimes these things turn out to be work 16-Aug-19 01:59 PM gn8! 16-Aug-19 02:00 PM gn 16-Aug-19 02:59 PM Does anybody here happen to have a wafer dicer? 16-Aug-19 03:20 PM Or an oxygen concentrator.... for sale? 16-Aug-19 03:20 PM Something something MAPP gas, something something black snow, something something room is now covered in black spots. 16-Aug-19 03:49 PM what did you do? Oo 16-Aug-19 03:50 PM Tried to run a small torch with compressed air and mapp gas 16-Aug-19 03:50 PM Instead of pure oxygen 16-Aug-19 04:33 PM Hrm so I was thinking of making a PSA system using zeolite sieves for making N2/O2 but I see some people get nitrogen membranes... I figured these were more expensive and less accessable, which I guess is true since I can't find any... But Does anyone know of a good source for them? 16-Aug-19 04:33 PM it would heavily simplify the system 16-Aug-19 04:33 PM I see PSA is best for purity but I don't care about 99% purity... 16-Aug-19 04:33 PM Getting to like 80-90% would be plenty good enough for me 16-Aug-19 04:42 PM PSA is cheaper overall 16-Aug-19 04:53 PM Is it? with the need for two pressure chambers, the material being somewhat expensive in the first place, valving and control/tuning? 16-Aug-19 04:53 PM Seems like a ready to go membrane may be more expensive but in terms of valuing time I may see the cost justifiable 16-Aug-19 04:59 PM oxygen concentrators are super cheap in the US 16-Aug-19 04:59 PM talk to medical supply places for scrap units 16-Aug-19 04:59 PM ask for those that can't be used medically 16-Aug-19 04:59 PM DIYing one is only worth it at a massive scale 16-Aug-19 04:59 PM think 40l cylinders each, 30 bar compressor 16-Aug-19 04:59 PM vents loud enough to make your ears ring 16-Aug-19 05:11 PM So, I was offered an A3 sized lithography thing today 16-Aug-19 05:11 PM A3 is way too big for my storage capabilities, so I had to pass. 16-Aug-19 10:52 PM Most oxygen concentrators I have seen seem to go for around 300-500 bucks used. There are a few that have gone lower but I question if they need new molecular sieves or not... 17-Aug-19 01:23 AM https://twitter.com/ConnorKrukosky/status/1162640979335229441 17-Aug-19 01:23 AM So uhm yea 17-Aug-19 01:23 AM Insulation dripping liquid are anyone? 17-Aug-19 01:28 AM ...goddamn you 17-Aug-19 01:29 AM hehe 17-Aug-19 01:29 AM have you ever measured your power draw? 17-Aug-19 01:29 AM I need a dewer with like a 3-4" opening and just push it up to the conflat so I get every last drip 17-Aug-19 01:29 AM I don't have a kill-a-watt for 240 twist-locks... 17-Aug-19 01:29 AM I might have a clamp meter somewhere 17-Aug-19 01:29 AM but the compressor is rated at 10A at 240V 17-Aug-19 01:29 AM so a lot I am sure 17-Aug-19 01:30 AM ahh, ok, I thought was running at 110V 17-Aug-19 01:30 AM Though once it cools down mostly it gets a bit higher pressure on the low side so I am sure it tapers off after startup 17-Aug-19 01:30 AM heh... no 17-Aug-19 01:30 AM this isn't one of those dinky sterling cycle cell site cryo heads 17-Aug-19 01:30 AM I do wish I had one of those though to play with! 17-Aug-19 01:30 AM Would be a lot more portable than this lol 17-Aug-19 01:30 AM but sadly people want stupid money for those due to a lot of people using them for this purpose 17-Aug-19 01:31 AM a cute little PTR like the superconductor tech ones 17-Aug-19 01:31 AM for LN2 on the go 17-Aug-19 01:31 AM so I will stick with my 130 dollar 60W cryo head and compressor 17-Aug-19 01:31 AM one guy on ePay is trying to sell one of those little PTR ones for making LN2 for 3 grand 17-Aug-19 01:31 AM he's nuts 17-Aug-19 01:32 AM worst thing is 17-Aug-19 01:32 AM veretasium did a video with one just like that recently 17-Aug-19 01:32 AM so I'm pretty sure someone will buy the thing 17-Aug-19 01:32 AM people like vertasium can pay for it 17-Aug-19 01:32 AM oh yea I am sure! 17-Aug-19 01:32 AM if they can find it 17-Aug-19 01:32 AM he doesn't say the company name either 17-Aug-19 01:32 AM tbh it took me a good solid few hours to find the company and find the listing LOL 17-Aug-19 01:32 AM like applied science doesn't say anything either 17-Aug-19 01:33 AM he does, in his blog 17-Aug-19 01:33 AM ah ok 17-Aug-19 01:33 AM I need to read his blog... 17-Aug-19 01:33 AM that no one seems to read or even know about xD 17-Aug-19 01:34 AM I actually remember reading this a long time ago 17-Aug-19 01:34 AM wait a second I bet I have it book marked 17-Aug-19 01:34 AM I wanted to build an LN2 gen for YEARSSSS 17-Aug-19 01:34 AM Its kinda funny I ended up doing this without even thinking about it lol 17-Aug-19 01:34 AM but yea... I have entire folders of bookmarks of info for this I found when I was like 12-14 years old lol 17-Aug-19 01:36 AM https://benkrasnow.blogspot.com/2008/08/diy-liquid-nitrogen-generator.html 17-Aug-19 01:37 AM yea I found it :) 17-Aug-19 01:37 AM but yea I really wonder if he says where he got his nitrogen membrane from 17-Aug-19 01:37 AM we found some on eBay but they were small and hundreds of dollars 17-Aug-19 01:37 AM just get an old, used O2 concentrator 17-Aug-19 01:37 AM they're very expensive on ebay, but not if you ask the right people, eg. in homes for the elderly 17-Aug-19 01:38 AM yea a PSA system seems just more fussy tbh, sure better purity but a lot more failure points I like the simplicity of the membrane system 17-Aug-19 01:38 AM yea... I will definitely keep an eye out for one! 17-Aug-19 01:38 AM but they seem to hold value 17-Aug-19 01:38 AM I mean makes sense, some old people can't afford new ones 17-Aug-19 01:40 AM plus they're medical devices, so if there's any sign of failure they have to get scrapped 17-Aug-19 01:40 AM at least here 17-Aug-19 01:41 AM oh I am sure, but if grandson is trying to get something for grandma who needs her oxygen machine, they don't care 17-Aug-19 01:41 AM a hospital will 17-Aug-19 01:41 AM a home would... 17-Aug-19 01:41 AM but not individuals 17-Aug-19 01:41 AM fair 17-Aug-19 01:42 AM but yea found most of the "membranes" by searching "nitrogen filter" on ePay 17-Aug-19 01:42 AM https://www.ebay.com/itm/QAM-GPF-6-N2-MAX-250-PSIG-FILTER-2-5-DIAMETER-QAM100171-NITROGEN/193048742444 17-Aug-19 01:42 AM Like this ain't a terrible price 17-Aug-19 01:42 AM if its what that is 17-Aug-19 01:45 AM hmm 17-Aug-19 01:45 AM not entirely convinced 17-Aug-19 01:48 AM yea me either 17-Aug-19 01:48 AM ah lol read description durp "can hear pellets inside" probably not or its borked 17-Aug-19 01:49 AM that's why I wasn't convinced 17-Aug-19 01:50 AM Eh I'll find or get something 17-Aug-19 01:50 AM What I need to do is get or make some high pressure sealable cylinders for the desiccants I have 17-Aug-19 01:50 AM So I can make at-least some dry air 17-Aug-19 01:50 AM the dessicants I have pounds of from work are bags of clay dessicant, so probably not as great as silica gel but should work just fine for free lol 17-Aug-19 01:50 AM https://www.uline.com/Product/Detail/S-8031/Desiccants/Tyvek-Bag-Desiccants-Unit-Size-4-34-Gallon-Drum 17-Aug-19 01:50 AM These guys to be exact 17-Aug-19 01:50 AM apparently you can re-activate in the bags! 17-Aug-19 01:52 AM sure, just bake them ^^ 17-Aug-19 01:52 AM at 245F 17-Aug-19 01:52 AM I would have expected the bags to burn lol 17-Aug-19 01:52 AM at-least on cheaper silica gel ones 17-Aug-19 01:52 AM but these are nice 17-Aug-19 01:52 AM ah, didn't think about that 17-Aug-19 01:52 AM if I can keep them in the bags it'll be less messy to re-gen the whole system 17-Aug-19 01:52 AM but yea I have like a 7" by 20" cylinder of these bags lol 17-Aug-19 01:52 AM so PLENTY 17-Aug-19 01:52 AM and I can get more just as easily 17-Aug-19 01:52 AM I just have to ask the guys who unpack our chips at work to save them for me 17-Aug-19 01:52 AM there are two per box which ussually have like 2-3 chips per box lmao 17-Aug-19 01:52 AM sometimes just one chip 17-Aug-19 01:52 AM its... silly but hey expensive chips! 17-Aug-19 01:54 AM xD 17-Aug-19 01:54 AM free silica gel for life 17-Aug-19 01:54 AM clay dessicant but yes free for life lol 17-Aug-19 01:54 AM but oh yea 17-Aug-19 01:54 AM bentonite? 17-Aug-19 01:54 AM I got you some video of liquid air pouring off my cryo head :P 17-Aug-19 01:55 AM try extracting the thorium 17-Aug-19 01:55 AM sure, just rub it in 17-Aug-19 01:55 AM https://www.uline.com/PDF/SS-5163.pdf 17-Aug-19 01:55 AM here is the SDS for the dessicant 17-Aug-19 01:55 AM SCINACLAYDES? 17-Aug-19 01:56 AM gesundheit 17-Aug-19 01:56 AM I dunno if its bentonite 17-Aug-19 01:56 AM but thorium huh? 17-Aug-19 01:57 AM most bentonites contain some thorium, that's why cat litter bags often trigger radiation alerts in shipping crates etc 17-Aug-19 01:58 AM ah lol 17-Aug-19 02:05 AM https://imgur.com/a/K9gHPst 17-Aug-19 02:05 AM The amount that pours off the head is kinda a lie because I believe the liquid air was up into the sintered copper at that point lol 17-Aug-19 02:05 AM so it was all running out of it 17-Aug-19 02:05 AM Still that amount in there was made in like an hour 17-Aug-19 02:05 AM hour after it got basically down to temp then I put that mug on 17-Aug-19 02:05 AM I was trying to run it with a pyrex glass on there but it was futile 17-Aug-19 02:05 AM it was just liquifying on the foam lol 17-Aug-19 02:07 AM :D 17-Aug-19 02:07 AM that's so awesome 17-Aug-19 02:07 AM But yea extremely happy with this, I can't NOT just make this stuff and play with it 17-Aug-19 02:07 AM I need to get some proper portable flasks and stuff so I can make everyone at work some liquid nitrogen icecream 17-Aug-19 02:07 AM lol 17-Aug-19 02:08 AM don't know about electricity cost in your area but at this point it might actually be cheaper than buying it in small quantities 17-Aug-19 02:08 AM Electric is pretty high but I think buying it would be fairly expensive here too 17-Aug-19 02:08 AM Its maybe SLIGHTLY cheaper 17-Aug-19 02:08 AM but its more fun :P 17-Aug-19 02:08 AM After you consider maintenance and or new hardware every now and then.... Its probably cheaper to buy LN2 but eh 17-Aug-19 02:08 AM whats the fun in that :P 17-Aug-19 02:10 AM right? :D 17-Aug-19 02:11 AM Just wish more of us were nearby each-other so we could all benefit from each other doing silly projects like this. Like Adam could use the LN2 on his SEM cold traps and EDS systems 17-Aug-19 02:11 AM I mean thats probably what I'll use mine for mostly 17-Aug-19 02:11 AM but yea it would be nice to share the stuff 17-Aug-19 02:25 AM applied ion and qualia could use our caps 17-Aug-19 02:25 AM stuff like that 17-Aug-19 02:25 AM we should get our own Island 17-Aug-19 02:26 AM lol 17-Aug-19 02:33 AM with an LN2 well in the middle 17-Aug-19 02:33 AM cooling down the LHe well beneath 17-Aug-19 02:33 AM pulsecaps grow in trees made of CF Hardware 17-Aug-19 02:41 AM heh 17-Aug-19 04:39 AM ok let's buy one 17-Aug-19 04:39 AM island 17-Aug-19 04:39 AM or a group of islands 17-Aug-19 04:39 AM rook islands style 17-Aug-19 05:00 AM bikini atoll should be cheap 17-Aug-19 06:56 AM heh yeah 17-Aug-19 04:12 PM afternoon! 18-Aug-19 02:06 AM Moin! 18-Aug-19 02:06 AM quick question about cryocoolers, I hope someone here is better at thermodynamics than me and @george 18-Aug-19 02:06 AM the joule-thomson effect doesn't work on He above 40 kelvin, so you can't cool it down in a linde refrigerator 18-Aug-19 02:06 AM BUT why do GM, PTR, Stirling and whatnot work with helium above 40 k 18-Aug-19 02:06 AM our guess was that cooling due to adiabatic expansion is enough to make it work 18-Aug-19 02:06 AM but if it is, why doesn't it work in linde coolers 18-Aug-19 07:44 AM and since we still know it somehow works its time for a home made gm 18-Aug-19 07:44 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/photo_2019-08-18_16-44-18-C66B8.jpg 18-Aug-19 07:45 AM oh hell yeah 18-Aug-19 10:14 AM I'm pretty sure they use helium because it has the best Prandtl number 18-Aug-19 10:14 AM Of any elemental gas (you can do better with mixtures of heavy noble gasses) 18-Aug-19 10:14 AM And by best I mean lowest 18-Aug-19 10:14 AM At least that's definitely why PTRs use it 18-Aug-19 10:14 AM I have some background in thermoacoustics 18-Aug-19 11:40 AM the reason for them to use helium is its low boiling point 18-Aug-19 11:40 AM thequestion is why it works.... 18-Aug-19 11:47 AM what effect is there that cools the He at a pressure difference of maybe 20 bar in a GM, PTR or what not, but not at an order of magnitude more in a linde liquefier 18-Aug-19 11:48 AM https://upload.wikimedia.org/wikipedia/commons/thumb/8/8f/Joule-Thomson_curves_2.svg/400px-Joule-Thomson_curves_2.svg.png 18-Aug-19 11:48 AM according to this diagram i should not be able to run the gm cooler using helium AND nitrogen 18-Aug-19 11:48 AM but both do work 18-Aug-19 11:48 AM and this question freaks me out 18-Aug-19 02:49 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-14203.png 18-Aug-19 02:49 PM shooould be almost done 18-Aug-19 02:49 PM just the regenerator assembly is missing 18-Aug-19 02:49 PM sadly i wont produce any for sale if the design works or im pretty sure cti would sue my ass for all kinds of patent violations 18-Aug-19 02:59 PM produce them for hobbyists :P 18-Aug-19 03:00 PM maybe open source for people with a lathe 18-Aug-19 03:00 PM im afraid selling pressure vessles with no profit margin is a risky buisiness 18-Aug-19 06:28 PM I think I'll actually go ahead and design a universal turbopump controller 18-Aug-19 07:13 PM I've decided that it'll only work for 4 or 2-phase sensored turbopumps for now, since I don't have a 3-phase turbo to test with, and the design would get a bit more complicated. If you want it to work with 3-phase turbos, send me one to test with :P 18-Aug-19 10:04 PM @0xDBFB7 ah, you are in here! I should've looked before mentioning it. 18-Aug-19 11:14 PM mhhh, though there is pretty intelligend vfds out there, maybe there already is a fitting one? 18-Aug-19 11:14 PM i know you can run old leybold ones off of them 18-Aug-19 11:54 PM You can run turbos off VFDs, but they generally output way too much voltage and the current limiting capabilities only exist on higher end models 18-Aug-19 11:54 PM I'm going to be targeting a max power supply voltage of around 70V and a max current of... I don't know, maybe 15 amps? Whatever the fets max out at. 18-Aug-19 11:54 PM That will cover 99.9% of turbos that are useful for hobbyists 18-Aug-19 11:54 PM On another note - does anyone here play with RF plasma? 18-Aug-19 11:54 PM I found an entire market of stupidly cheap medical RF generators that might be worth trying to hack, but they're all at around 200-500kHz and have odd impedance requirements, anywhere from 100 to 500 ohms. 18-Aug-19 11:54 PM But they are really cheap and can output tons of power(hundreds of watts) 18-Aug-19 11:54 PM The "for real" power generators are surprisingly expensive on eBay - almost no good working units for under $500, and most tend to be in the multi-kW 3ph input power, need-two-people-to-life range. 19-Aug-19 12:29 AM oh, there issmall danfoss ones capeable of bldc and low voltage operation ^^ 19-Aug-19 12:29 AM and they are not even that expensive 19-Aug-19 12:29 AM (used) 19-Aug-19 12:38 AM Still not as advanced though 19-Aug-19 12:38 AM You could implement the logic with a controller talking to it, but what's the point at that point 19-Aug-19 12:38 AM Could just build your own drive for less than $100-200 19-Aug-19 12:42 AM mh yes, but 100-200 is also roughly the figure of a used vfd 19-Aug-19 12:42 AM i have gone that way and usually its not worth it 19-Aug-19 12:42 AM Well, I've already built my own 4-phase controller 19-Aug-19 12:42 AM It's just that it's sitting on perfboard and I had to do math to avoid spurious noise on the hall sensor readings 19-Aug-19 12:43 AM youst pick accordingly, there is pumps running off of 3 phase low voltage, they can be run with VESC controllers, there is high voltage, they can be run on vfds 19-Aug-19 12:43 AM Something something signal integrity 19-Aug-19 12:43 AM jup, the 4phase ones are the only annoying ones but they are really simple 19-Aug-19 12:43 AM 2 phase is just 4 phase but 2 in parallel, pretty much 19-Aug-19 12:43 AM So the controller can be shared 19-Aug-19 12:43 AM And for 3 phase I'm thinking of doing a small embedded module 19-Aug-19 12:43 AM Or just using a cheap RC car ESC for low voltage turbos, since not all of them need 70V at 10A to start 19-Aug-19 12:44 AM well, or just use vesc... 19-Aug-19 12:45 AM vescs are like $200 alone 19-Aug-19 12:45 AM if needed its als pretty easy to give it a different output stage 19-Aug-19 12:45 AM but they are open source 19-Aug-19 12:45 AM at least were 19-Aug-19 12:45 AM but they are $200 19-Aug-19 12:45 AM so the software and basic layout is out there 19-Aug-19 12:45 AM naaaahhhh 19-Aug-19 12:45 AM bill of materials is maaaybe 50 19-Aug-19 12:45 AM I already have the software and I'm really good at making embedded UI 19-Aug-19 12:45 AM and you can't talk me out of it because I already ordered a bunch of cheap displays and I need to put them to use now 19-Aug-19 12:45 AM one for the vacuum meter/station controller combination, one for the turbo drive 19-Aug-19 12:45 AM in NIM-style housings so they all fit nicely together c: 19-Aug-19 12:47 AM I'll build a modular vacuum controller, for eating all the different probes 19-Aug-19 12:47 AM log analog, pfeiffer protocol, thermocouple drivers.... 19-Aug-19 12:47 AM just in my experience the stuff got pretty cheap by now 19-Aug-19 12:47 AM the vacuum controllers and gauges are often incompatible and/or very very different from mfg to mfg 19-Aug-19 12:47 AM and for soeone with a money problem it wont be useful to have one for all that costs more than a used specific one 19-Aug-19 12:48 AM as for turbos, having a universal controller is nice 19-Aug-19 12:48 AM especially if it's cheap 19-Aug-19 12:48 AM just usually people have one or two pumps and thats it 19-Aug-19 12:48 AM the BOM is probably going to be around $20 19-Aug-19 12:48 AM + housing 19-Aug-19 12:48 AM really depends on the power stage 19-Aug-19 12:48 AM jup 19-Aug-19 12:48 AM bigger fets = exponentially more money 19-Aug-19 12:48 AM naaaaahh not today 19-Aug-19 12:48 AM fets are still so cheap 19-Aug-19 12:49 AM but cheap is relative! :P 19-Aug-19 12:49 AM in the sizes needed for turbos they are all peanuts 19-Aug-19 12:49 AM if small $0.40 fets can drive my turbo, a big leybold that wants 700 watts to start will require $4 fets 19-Aug-19 12:49 AM not expensive by any means, but there goes $16 of the BOM 19-Aug-19 12:50 AM but isnt that the purpouse of having a home made one? 19-Aug-19 12:50 AM or, well, in the case of a 3ph driver, $36 19-Aug-19 12:50 AM so you can use the ones you need? 19-Aug-19 12:50 AM yep 19-Aug-19 12:50 AM it'll be more or less universal 19-Aug-19 12:50 AM the drivers are gonna be more expensive 19-Aug-19 12:50 AM the controller is the same, populate the parts you need 19-Aug-19 12:50 AM gate drivers are CHEAP 19-Aug-19 12:50 AM the trick is to not buy those turbo-intelligent ones 19-Aug-19 12:50 AM and when you have to run a 700w pump you will not worry about 20 bucks 19-Aug-19 12:51 AM it's just relying on luck 19-Aug-19 12:51 AM but they are worth it 19-Aug-19 12:51 AM I got this one and it wants 100ish watts on startup if given the full 30ish volts 19-Aug-19 12:51 AM dont go to cheap, it wont be fun 19-Aug-19 12:51 AM but there's stupidly cheap giant leybold turbos that I mentioned a bit ago 19-Aug-19 12:51 AM the cartridge pumps 19-Aug-19 12:51 AM and they already have a cntroller 19-Aug-19 12:51 AM the cheap ones don't have the td400 :( 19-Aug-19 12:52 AM file:///home 19-Aug-19 12:52 AM gnah 19-Aug-19 12:52 AM ...so close 19-Aug-19 12:52 AM that's not how it works 19-Aug-19 12:52 AM :P 19-Aug-19 12:52 AM tahts what hapens when you ctrlC the image in a folder... 19-Aug-19 12:52 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/turbo-66A46.jpg 19-Aug-19 12:54 AM that's the less cheap one 19-Aug-19 12:54 AM built the cartridge seal yourself? 19-Aug-19 12:54 AM yes 19-Aug-19 12:54 AM and its 200 for the entir cartridge with controller 19-Aug-19 12:55 AM I'm contemplating getting one of those cheap ones with dead bearings 19-Aug-19 12:55 AM are they a standard size? 19-Aug-19 12:55 AM at least here you cant get it without controller 19-Aug-19 12:55 AM i havet taken this one apart but i know someone who crashed one 19-Aug-19 12:55 AM ill ask him about the size 19-Aug-19 12:57 AM they look uncrashed 19-Aug-19 12:57 AM but the seller says "I am unable to turn the device with my hand" on one 19-Aug-19 12:57 AM and "Spins freely, appears to have bearing issue" on the other 19-Aug-19 12:57 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/tmp-52133.jpg 19-Aug-19 12:57 AM that is a brutal way to turn a billet into a tube 19-Aug-19 12:58 AM the spins freely one could be allright 19-Aug-19 12:58 AM 19V @ 6A 19-Aug-19 12:58 AM 48krpm 19-Aug-19 12:58 AM only 2015 19-Aug-19 12:58 AM well yes, but holow stock in this size is more expensive 19-Aug-19 12:58 AM it had to be a bit smaller on one side for the iso 100 19-Aug-19 12:59 AM the ones on ebay are huge 19-Aug-19 12:59 AM turbovac 400/300/25s 19-Aug-19 12:59 AM at 48k you may get away with very high quality generic bearings 19-Aug-19 12:59 AM mine is a 290 but removed the old housing 19-Aug-19 12:59 AM i didnt just buld an adapter 19-Aug-19 12:59 AM i think original diameter was around 200mm 19-Aug-19 12:59 AM of useless cheese aluminium 19-Aug-19 12:59 AM im just not so sure about this pumps construction and if the bearings are a standard size 19-Aug-19 12:59 AM i had an issue with the small varian / agilent pumps as they use a special size with 6.1mm bore 19-Aug-19 01:02 AM I guess I could machine an adapter/shim to a standard size 19-Aug-19 01:02 AM I sure as hell don't have the capability to machine the housing on my own, I'd need to annoy my friend into letting me have free reign over his big lathe 19-Aug-19 01:02 AM there is one manufacturer for those bearings and they sell 10 pieces @ 200 € as the cheapest option 19-Aug-19 01:02 AM yes, shimming is possible but not easy 19-Aug-19 01:02 AM He also has grinding equipment, including a gear grinder 19-Aug-19 01:02 AM you will have to machine the shim on the rotor 19-Aug-19 01:02 AM So I could make the most stupidly precise shim 19-Aug-19 01:03 AM and having the entire rotor in the grinder is ha really "interesting" feeling 19-Aug-19 01:03 AM nah, I'd make the shim myself 19-Aug-19 01:03 AM or grind the bearing race out 19-Aug-19 01:03 AM nah, grinding the bearing is stupid, you will do it every time you have to change it 19-Aug-19 01:03 AM thats annoying af 19-Aug-19 01:04 AM or I can just get a stack of bearings and put them away in to a special bearing seize box 19-Aug-19 01:04 AM chrinkfit an oversized shim on the shaft is what im saying 19-Aug-19 01:04 AM "in case of emergency, take one" 19-Aug-19 01:04 AM and machine it down to the right diameter 19-Aug-19 01:04 AM right 19-Aug-19 01:04 AM wait, shrinking onto aluminium? 19-Aug-19 01:04 AM that'd deform the rotor to hell 19-Aug-19 01:04 AM tehre is no ftting accurate arts an expecting them to stay in shape/position here 19-Aug-19 01:04 AM nah, i works fine 19-Aug-19 01:04 AM its a shim with less than .5mm thickness made from brass 19-Aug-19 01:04 AM no problems there 19-Aug-19 01:05 AM Sent the ebay seller a question of how much it'll cost to ship these monsters to Belarus 19-Aug-19 01:05 AM but well, maybe you are lucky and its not one of the a**hole diameter 19-Aug-19 01:05 AM I'm betting it'll be double the price of the pumps, because he's selling them for scrap metal prices 19-Aug-19 01:05 AM oh :d 19-Aug-19 01:05 AM And there ain't much metal to scrap in a turbo 19-Aug-19 01:05 AM I want a turbodrag pump for glassblowing experiments 19-Aug-19 01:05 AM They're happy being vented to air 19-Aug-19 01:05 AM Sadly they seem to be a thing of the past 19-Aug-19 01:05 AM do you have a pinout for the DB connector on the bottom? 19-Aug-19 01:05 AM the one on the housing, so yours would probably be covered by the turbodrive itself 19-Aug-19 01:05 AM doesn't seem like leybold shared it anywhere 19-Aug-19 01:12 AM mhhh, im really not sure but there may be something in a file i have 19-Aug-19 01:12 AM i opened it up back then but i cant remember 19-Aug-19 01:12 AM i just know its 3 phase and no hall 19-Aug-19 01:13 AM it'd be pretty nice to have a big pump if I can buy it 19-Aug-19 01:13 AM it'd be comically oversized for my vacuum station 19-Aug-19 01:13 AM ISO300(ish) to KF50... lol 19-Aug-19 01:13 AM oh, i just remembered, i still have two prototype boards frm an inturnship at the company that made the newer turbodrives for them 19-Aug-19 01:13 AM never got them to work sadly 19-Aug-19 01:13 AM propably some developement firmware on them or something... 19-Aug-19 01:14 AM if I don't succeed I'll just run it backwards and hang it as a fan 19-Aug-19 01:14 AM 480rpm instead of 48000 19-Aug-19 01:14 AM and now I must sleep 19-Aug-19 01:19 AM gn8! 19-Aug-19 08:50 AM rescheduled freight delivery for thursday.. going to rain on wednesday and if I didnt get it in the house on the tuesday delviery date... I would prefer to not put a tarp over it 19-Aug-19 02:36 PM afternoon! 19-Aug-19 03:03 PM night! 19-Aug-19 03:03 PM oh wait, good morning! 19-Aug-19 04:00 PM For my universal vacuum meter reader, I think I'm going to go with a backplane system 19-Aug-19 04:00 PM Display+UI+controls on one side of a PCB, global PSU+PCI slots on the other 19-Aug-19 04:00 PM and the readers will slot in 19-Aug-19 04:00 PM probably internal RS485 communication between modules 19-Aug-19 04:00 PM something like 24V @ 5-10A for the power supply, distributed to every module 19-Aug-19 04:00 PM I wish there was an off the shelf solution for this 19-Aug-19 04:19 PM something between NIM and Eurocard or similar, then? 19-Aug-19 04:19 PM haven't worked with eurocard but i know m-labs builds all their hardware on that backplane format iirc 19-Aug-19 04:19 PM i think CAMAC has backplane data 19-Aug-19 04:20 PM yeah 19-Aug-19 04:20 PM I wonder what the turbopump controllers fit into 19-Aug-19 04:20 PM they all seem to have the same height 19-Aug-19 04:28 PM they look like they're meant to sit in a 3U rack frame 19-Aug-19 04:28 PM at least, the one for my varian v80 clone is 19-Aug-19 04:38 PM there's turbopump clones? 19-Aug-19 04:47 PM this is sort of what I'm imagining 19-Aug-19 04:47 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/cPCIS-ET1100_Series_ProductImage_en_201704-B2B00.png 19-Aug-19 04:47 PM except smaller 19-Aug-19 04:47 PM and not $2000 19-Aug-19 05:13 PM rackmount? 19-Aug-19 05:13 PM I think rackmount is the perfect chassis for most equipment that may be stackable 19-Aug-19 05:14 PM It could be made rackmount 19-Aug-19 05:14 PM but the issue is the internal backplane itself 19-Aug-19 05:15 PM you can also buy those angled flanges to put onto anything, so they dont need to be a certain width by default.. just setup/buy the two vertical bars and set your own width, good to go 19-Aug-19 05:15 PM say you have 3-4 gauges 19-Aug-19 05:15 PM plus, say, an rs485 module to talk to the universal turbo controller 19-Aug-19 05:15 PM a power supply module 19-Aug-19 05:15 PM and a relay module to control a couple valves, powering the forepump 19-Aug-19 05:16 PM so long as there is access to the plugs/recepticles in the back.. 19-Aug-19 05:16 PM So what are we talking about? Single board computers and various busses and interfaces? 19-Aug-19 05:16 PM yeah, so I'm thinking that the backplane will be a frontplane instead 19-Aug-19 05:16 PM no SBC, just a main brain with a display 19-Aug-19 05:16 PM There is a lot of stuff out there 19-Aug-19 05:16 PM it'll talk to gauge reading modules 19-Aug-19 05:16 PM power control 19-Aug-19 05:16 PM internal comms will be rs485 19-Aug-19 05:17 PM So a PC with an RS-485 card 19-Aug-19 05:17 PM no 19-Aug-19 05:17 PM lol 19-Aug-19 05:17 PM whether that PC be PC-104 formfactor or whatever you like 19-Aug-19 05:17 PM no 19-Aug-19 05:17 PM What do you need that a PC can't do? 19-Aug-19 05:17 PM not be a kludgy mess 19-Aug-19 05:18 PM ASIC 19-Aug-19 05:18 PM Uhm 19-Aug-19 05:18 PM so what, it'll be running a common OS 19-Aug-19 05:18 PM you realize half of the "products" your looking at are just PCs in special formfactors 19-Aug-19 05:18 PM a single server is hardly 'kludgy' 19-Aug-19 05:18 PM and half the time are kludgy messes in nice boxes 19-Aug-19 05:18 PM and I'm not trying to make something like that 19-Aug-19 05:18 PM it'll be simple and low level 19-Aug-19 05:18 PM I have torn apart TONS of industrial control gear and yea 19-Aug-19 05:18 PM I mean just make something fuctional with common equipment 19-Aug-19 05:18 PM then if you want to button it up look into special formfactor stuff and compacting it 19-Aug-19 05:19 PM make it serviceable 19-Aug-19 05:19 PM Because if you start down some route with a specific box or formfactor 19-Aug-19 05:19 PM which means easy to obtain parts(and software) 19-Aug-19 05:19 PM then find out you want to expand it with X and find out that formfactor is limited in a way you can't add X 19-Aug-19 05:19 PM there exists no common equipment that does this for a low price 19-Aug-19 05:19 PM you just played yourself and wasted money 19-Aug-19 05:19 PM that does what? rs232? 19-Aug-19 05:20 PM a universal vacuum controller 19-Aug-19 05:20 PM No, all of this stuff is thousands of dollars new, your going to be looking at old used equipment if you want nice formfactor industrial control stuff 19-Aug-19 05:20 PM with gauge reading modules, pump control 19-Aug-19 05:20 PM uhhh 19-Aug-19 05:20 PM yea your looking at a probably 10K box 19-Aug-19 05:20 PM like companies make them 19-Aug-19 05:20 PM which is plain stupid 19-Aug-19 05:20 PM but there is no universal thing 19-Aug-19 05:20 PM I'm MAKING a universal thing 19-Aug-19 05:20 PM you need their gauges and their controllers 19-Aug-19 05:20 PM no 19-Aug-19 05:20 PM there is no standard.. you're going to have 20 libraries/interfaces for all the different kinds 19-Aug-19 05:21 PM 99% of the gauges output a logp voltage 19-Aug-19 05:21 PM so your going to support all digital and analog gauges? 19-Aug-19 05:21 PM most analog 19-Aug-19 05:21 PM and in the end, you're going to end up writing a kernel for it all? 19-Aug-19 05:21 PM some digital 19-Aug-19 05:21 PM Uhm sure ones that have built in circuitry 19-Aug-19 05:21 PM each module will read a specific gauge 19-Aug-19 05:21 PM and most good gauges have built in electronics anyway 19-Aug-19 05:21 PM except thermocouples 19-Aug-19 05:21 PM which are easy to make a universal driver for 19-Aug-19 05:21 PM the most useful gauges are those that output logp or speak already documented protocol 19-Aug-19 05:21 PM pfeiffer, inficon 19-Aug-19 05:22 PM Also I already started designing a gauge controller for most of PFeiffer gauges 19-Aug-19 05:22 PM I already built one 19-Aug-19 05:23 PM I am confused here then 19-Aug-19 05:23 PM you were asking about stuff now your just saying its done? 19-Aug-19 05:23 PM it only talks to pfeiffer gauges and it's not modular 19-Aug-19 05:23 PM I'm going to build a modular vacuum gauge reader/station controller 19-Aug-19 05:23 PM because I need one and I like the idea 19-Aug-19 05:23 PM i feel like your effort might be best spent writing a general purpose bit of library software that can talk to arbitrary gauges and then start adding in controller support bit by bit 19-Aug-19 05:24 PM that's pretty much what I'm going to do 19-Aug-19 05:24 PM I only have pfeiffer protocol, logp, and thermocouple right now 19-Aug-19 05:24 PM no inficon 19-Aug-19 05:24 PM or, like, if you're going for a vacuum system control platform, the whole state machine mechanism around that will be an interesting and challenging bit of work 19-Aug-19 05:25 PM for now it'll just read the vacuum level and maybe blend it with weights 19-Aug-19 05:25 PM I thought I already announced that I was working on this exact thing basically but its just a gauge controller/readout. It does have a USB->Serial on it though so it could have added communications to a PC to control other stuff. 19-Aug-19 05:26 PM (thermocouples with lower weights, piezo/cap transducer with higher weights, that kind of stuff) 19-Aug-19 05:26 PM mine will definitely have USB 19-Aug-19 05:26 PM and maybe ethernet 19-Aug-19 05:26 PM not sure if I want ethernet, but it's fairly trivial to add on the hardware side 19-Aug-19 05:26 PM the idea is to have ultra low cost gauge reader modules 19-Aug-19 05:26 PM in some cases almost free(RS485/232 for pfeiffer and inficon) 19-Aug-19 05:28 PM from a software angle i would love an open source vacuum process controller that let me define my system and my gauges/valves/etc in some DSL, and let me build pipelines like 'rough the chamber, spin up the turbo, check the RGA, light up some heaters for a while until water's driven out, let it cool down, if pressure's below 10^-8 then turn on the MFC.." etc 19-Aug-19 05:29 PM I think I'll make it opensource 19-Aug-19 05:29 PM but the sequencing won't come until later 19-Aug-19 05:29 PM not sure if I want to make the brains complicated or not 19-Aug-19 05:29 PM I feel a bit weird trying to stuff linux into it, the original plan was an stm32f1 or maybe f4, but backed by mbed or arduino so it's easier for less skilled people to extend 19-Aug-19 05:30 PM i have considered slapping an atmega on a tiny board with a voltage divider for some of my gauges 19-Aug-19 05:30 PM but lazy 19-Aug-19 05:30 PM the reader modules will all have either mega328 or stm32f108 19-Aug-19 05:30 PM because cheap 19-Aug-19 05:30 PM the protocol will have a few mandatory commands and the rest will be totally flexible 19-Aug-19 05:30 PM the logp reader will probably be just that, a multichannel ADC with voltage dividers 19-Aug-19 05:30 PM might just go with a teensy for the main controller brain 19-Aug-19 05:30 PM the latest teensies are super powerful 19-Aug-19 05:39 PM oh, yeah, my last arduino control adventure consisted of me slapping Firmata on a Mega and then poking at it with python on a host computer 19-Aug-19 05:39 PM i can't stand embedded development i'm far too lazy 19-Aug-19 05:39 PM I like embedded development 19-Aug-19 05:39 PM but I'm struggling to find a competent desktop C++ dev 19-Aug-19 11:32 PM Labview can't do what you want? 19-Aug-19 11:45 PM Labview is a hack and should be avoided at all costs 19-Aug-19 11:49 PM Matlab? 19-Aug-19 11:50 PM Same deal 19-Aug-19 11:50 PM Not for production imo 19-Aug-19 11:50 PM Plus ties you to a PC 19-Aug-19 11:57 PM I've always had the impression that labview is used in a lot in factory production systems 19-Aug-19 11:58 PM Yeah it's pretty good for that sort of thing 19-Aug-19 11:58 PM Should you sell a product with it in it? Probably a cheaper option out there. Should you build a product with it? Yeah 19-Aug-19 11:58 PM It's advantage is how many different things you can quickly bring together with it 19-Aug-19 11:59 PM I had a piece of lab equipment (forget what it was) that used a self-contained labview executable for its control software. 20-Aug-19 12:00 AM I'm a firm believer in the idea of keeping simple things simple. 20-Aug-19 12:00 AM It was a microfluidic viscometer! 20-Aug-19 12:00 AM It ain't cheap but when time is money and you have an entire line that needs to be constantly updated with new sensors, actuators and feedback loops it does a good job 20-Aug-19 12:00 AM Controlling an entire sem? Labview is okay. Reading gauges? Absolutely not 20-Aug-19 12:01 AM Yeah one off dodad... Probably not unless you already use it for everything else then consistency is more important 20-Aug-19 12:01 AM This will be an embedded card cage host 20-Aug-19 12:02 AM To be clear I'm not saying it's right for you 20-Aug-19 12:02 AM How much is a one off license for labview theese days? 20-Aug-19 12:02 AM In the slightest 20-Aug-19 12:02 AM At all 20-Aug-19 12:02 AM Yeah, I know 20-Aug-19 12:03 AM Just saying it's got it's purpose 20-Aug-19 12:03 AM A lot... 20-Aug-19 12:03 AM That’s what I figured 20-Aug-19 12:03 AM My first and biggest peeve is the atrocious UI 20-Aug-19 12:03 AM FYI, with temporary email accounts, you can create new Matlab trial accounts every month.... or so I've heard.... 20-Aug-19 12:04 AM Allegedly is the word I believe you are looking for 20-Aug-19 12:04 AM friend of a friend told me 20-Aug-19 12:04 AM If you're going to go that far, might as well pirate it lol 20-Aug-19 12:05 AM I feel like we are quickly approaching you should not use the website sci hub that gives you questionably obtained scientific papers territory here 20-Aug-19 12:05 AM Hahahahaha 20-Aug-19 12:06 AM Scihub is great 20-Aug-19 12:06 AM Don't use sci hub 20-Aug-19 12:06 AM never used scihub, must investigate.... 20-Aug-19 12:06 AM The website that gives be you free scientific papers 20-Aug-19 12:06 AM The scientists and reviewers don't see a penny from the publisher cartels 20-Aug-19 12:07 AM Whistling a non discript tune and slowly walking away is not a legitimate defense or alliby? 20-Aug-19 12:07 AM Most pay to publish and review to be reviewed, while the publishers swim in money 20-Aug-19 12:08 AM created in Kazakhstan, seems legit.... 20-Aug-19 12:09 AM By one girl who couldn't get access to the info she needed to study 20-Aug-19 12:09 AM No comment here. I have never done any base research with which I could have something published 20-Aug-19 12:09 AM Only historical type things for Hack A Day 20-Aug-19 12:10 AM I find papers to be fairly useful for fringe subjects 20-Aug-19 12:11 AM I just let people list me as an author and have them do all the writing. 20-Aug-19 12:11 AM I contribute like one paragraph 20-Aug-19 12:11 AM Hahahahaha. 20-Aug-19 12:11 AM Do I spot a Prof or lazy PhD 20-Aug-19 12:12 AM Well I think I might try going to sleep now. 20-Aug-19 12:13 AM mechanical engineer developing devices for microbiologists. all my work ends up being like a small footnote in the paper. 20-Aug-19 12:13 AM Heh 20-Aug-19 12:13 AM Free credit 20-Aug-19 12:14 AM "We tested our theory with this device that piGuy spent 6 months designing and building" 20-Aug-19 12:14 AM This is @Goldsteel 20-Aug-19 12:14 AM The theory was wrong 20-Aug-19 12:14 AM Except he's a particle physicist 20-Aug-19 12:15 AM There is a non-zero possibility I could test positive for ebola exposure.... 20-Aug-19 12:15 AM Oh 20-Aug-19 12:16 AM That reminds me I need to come look at your scope 20-Aug-19 12:16 AM but it's practically zero, just not non-zero. 20-Aug-19 12:16 AM @AdamMcCombs , I will do whatever it takes to get you to look at it! 20-Aug-19 12:17 AM Well let's see what I'm doing tomorrow 20-Aug-19 12:17 AM I might be unexpectedly available due to... Reasons... 20-Aug-19 12:17 AM Also same goes for @noxz 20-Aug-19 12:17 AM Still don't know for sure but 20-Aug-19 12:17 AM @Noxz 20-Aug-19 12:20 AM His delivery comes tomorrow or Thursday, something like that? 20-Aug-19 12:21 AM Something 20-Aug-19 05:08 AM I just work here 20-Aug-19 08:20 AM Thursday 20-Aug-19 08:20 AM rescheduled due to the rain coming tomorrow 20-Aug-19 08:20 AM incase I was unable to get it inside today 20-Aug-19 08:20 AM better safe than not safe 20-Aug-19 08:20 AM have a tarp and all, but yeah.. 20-Aug-19 08:32 AM btw, the current plan is to take as much of the machine apart as I can to make hauling the base easier 20-Aug-19 08:46 AM $200/day for a forklift rental would certainly be advantageous 20-Aug-19 08:46 AM doesnt have to go far 20-Aug-19 08:46 AM half reminds me to jump on the roof today to make sure those douglas fir needles are clear of the drain for the rain 20-Aug-19 12:51 PM @Noxz , my offer still stands to come help (or stand around and watch) if needed. 20-Aug-19 01:11 PM noted 20-Aug-19 01:15 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/vakuumloten_Teststucke-3C135.jpg 20-Aug-19 01:15 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/vakuumloten_gesamtaufbau-F19EF.jpg 20-Aug-19 01:15 PM finally something useful to do with vacuum 20-Aug-19 01:19 PM I like the setup.. fairly clean imo 20-Aug-19 01:25 PM Yea looks nice! What is it for? Sputtering chamber or something? 20-Aug-19 01:28 PM Looks like a desiccator on steroids 20-Aug-19 01:31 PM kinda 20-Aug-19 01:31 PM vacuum brazing 20-Aug-19 01:31 PM allways wanted to do that but never had an applcation, now ill braze some copper parts for the home made gm coldhead 20-Aug-19 01:33 PM cool 20-Aug-19 01:34 PM sadly on the first attempt the glass heated to much, will retry tomorrow using a server fan to cool the entire thing 20-Aug-19 09:09 PM What are you using as a heat source? Induction RF? 21-Aug-19 12:05 AM for now just resistive but as soon as i get around to finish the induction heater that will be it 21-Aug-19 12:05 AM i could put the test setup back together but for now its not worth the work 21-Aug-19 01:13 AM https://i.spirit.re/W0jwn.jpg 21-Aug-19 01:13 AM This is why you don't let intern programmers make your UIs 21-Aug-19 02:26 AM moin 21-Aug-19 02:41 AM Wow, Comic Sans and double gradients? I did not know it was possible to design industrial interfaces with ms word 21-Aug-19 02:41 AM moin 21-Aug-19 02:41 AM (but apart from the questionable typographical choice of having a serif, two sans, at least three different font sizes, resulting in 7+ combinations visible, the interface looks very usable) 21-Aug-19 08:54 AM TBH I bet that came out of someone who was a senior programmer 21-Aug-19 08:54 AM just not a UI designer lol 21-Aug-19 08:54 AM You don't seem to realize that programming and UI design are not even close to the same thing 21-Aug-19 09:17 AM b...but teh colors 21-Aug-19 09:17 AM like R, G & B - makes sense 21-Aug-19 10:12 AM @Conmega that's why it was probably designed by a programmer 21-Aug-19 10:12 AM "You wrote the algorithms, make it pretty" came down from somewhere above, and.... 21-Aug-19 10:20 AM lol 21-Aug-19 12:51 PM Needs some Papyrus font... 21-Aug-19 03:26 PM @Noxz still on track for delivery tomorrow? 21-Aug-19 03:26 PM Yes, 11am-4pm, with a 30min courtesy call before 21-Aug-19 03:26 PM .. are you available to help?!? 21-Aug-19 03:27 PM Yeah it looks like it 21-Aug-19 03:27 PM I was just cleaning up the area it is going to live in, pushed the engine aside.. all that is in the way is basically the surface plate+stand, and a box full of chemicals (not mine, but mine now) 21-Aug-19 03:27 PM I think there is some NaBH4 in there... 21-Aug-19 03:27 PM amongst other things, but yeah.. basically gearing up for it 21-Aug-19 03:28 PM So what's your current plan? 21-Aug-19 03:28 PM the basic plan was basically get it near enough my entry steps, and take it apart, down to the base 21-Aug-19 03:28 PM Then? 21-Aug-19 03:28 PM but.. with help, that may change 21-Aug-19 03:28 PM well, I have a crumy-not-socrumy 800lbs rated dolly that I figured would be good enough to pull up the base 4 steps 21-Aug-19 03:28 PM but, yeah, plans may change if I have help.. 21-Aug-19 03:28 PM if able to, rent a forklift for me.. would make it a 5min job 21-Aug-19 03:31 PM Have you fixed the uneven landing? 21-Aug-19 03:31 PM nope, had some ideas, but nothing actually happened with it.. I could build a lattice tomorrow AM 21-Aug-19 03:31 PM part of it was I had no idea where the machine was for a while 21-Aug-19 03:31 PM not that it would have been terrible to have had a landing in place 21-Aug-19 03:31 PM also, was about to head out for a small dog walk, havent been out since the misty hike this morning.. will you be around in say, 30 mins? 21-Aug-19 03:31 PM I can also start building the landing when I get back 21-Aug-19 03:31 PM I think part of that was that if my backup was to disassemble without help, then no need for a landing 21-Aug-19 03:31 PM doh! started to rain 21-Aug-19 03:31 PM which is that it is happening today, and not tomorrow or whenever 21-Aug-19 03:31 PM so, half thought - would be better to build the landing tomorrow (if that is what should be done) to dodge the rain and keep it all sturdy - not soft 21-Aug-19 03:31 PM gotta love the sporratic brain dump, eh? 21-Aug-19 03:31 PM .. dog walk, bbiab 21-Aug-19 05:05 PM we were just gifted a doggie backpack from a previous dal owner! 21-Aug-19 11:29 PM I think I'm going to try using mechanical keyboard switches for my next projects, including the turbo and vacuum controllers 21-Aug-19 11:29 PM I use an Alps based keyboard 21-Aug-19 11:30 PM I meant that as in, individual buttons 21-Aug-19 11:30 PM Starting/stopping the turbo for example 21-Aug-19 11:30 PM yeah, I know 21-Aug-19 11:30 PM afaik Alps doesnt make individual keys anymore 21-Aug-19 11:30 PM so, you're "stuck" with Cherry and it's clones 21-Aug-19 11:31 PM still not a bad deal 21-Aug-19 11:31 PM in some cases less than $0.2 per switch 21-Aug-19 11:31 PM but I'm thinking of using the highest actuation force ones, just to have that vintage tactile feel 22-Aug-19 05:06 AM moin 22-Aug-19 05:54 AM Newbie UHV question: when using a turbo molecular pump as leyblod TW 290/20/20 , do I need to a suitable sized backing pump to exhaust to atmosphere ? (Read this on several paper ) ... any link to great ressource about that will be Cool . Thanks 22-Aug-19 06:05 AM It seems that backing pump is mandatory (according to Wikipedia) but what type of backing pump I could use ? A normal one ? Have you some exemple of pump I could use ? ( my objective is 10^-11 to 10^-12 torr) 22-Aug-19 06:05 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-EE5EC.jpg 22-Aug-19 06:06 AM yep, atm there's no UHV pump that can vent directly into atmosphere 22-Aug-19 06:17 AM i would recommend a oil free scroll pump 22-Aug-19 06:27 AM an 22-Aug-19 06:37 AM What is the ideal pump ignition sequence : 1st the dry scroll pump (wait for pressure down to 10-4), 2nd the turbo molecular pump (wait for pressure down around 10-8/10-9) & finally turn on the ion pump ? Is that correct ? Do I need to switch off already powered pump before started the next one (newbie question ) 22-Aug-19 06:38 AM yep, although 10^-4 might be a bit optimistic 22-Aug-19 06:38 AM you can switch the TMP on as soon as you have reached it's maximum allowed pressure 22-Aug-19 06:38 AM plus the TMP pumping will take a long time, for 10^-8 and below you'll have to bake 22-Aug-19 06:41 AM If I use a TMP , it’s not mandatory to use Ion pump ? Or do I need Ion Pump OR a TMP pump but not both ... Or do I need to use both for my UHV objective ? 22-Aug-19 06:41 AM I will bake for sure 22-Aug-19 06:45 AM the pressures given by the manufacturers for finalpressure arepretty much theoretical numbers, you can see them more as a limit for doing calculations 22-Aug-19 06:45 AM a normal vanepump may be classified as 10-4but in reality in suchasetup it will do 10-1 or 10-2 22-Aug-19 06:45 AM a turbo with a given final pressure of 10-11 is most likely gonna be good für 10-8, maybe 10-9 if yoursetup is very good 22-Aug-19 06:45 AM i think if you dont have unlimited finantial resources, -11 to -12 is not realistic, thats some hardcore stuff there... 22-Aug-19 06:45 AM i reached 10-8 with my 290/20/20, thats pretty achieveable, maybe a bit better would be possible but.... 22-Aug-19 06:48 AM and the forepump will run all the time 22-Aug-19 06:48 AM you will just first pump everything down to 1mBar or so and then start your turbo because before that point itwill not spool up 22-Aug-19 06:48 AM also venting your chamber with the turbo spinning will wreck it instantly 22-Aug-19 06:50 AM I see that @N00N succeed to go to 2 10-12 on a twitter photo ... is he a rockstar of UHV ? 22-Aug-19 07:22 AM as far as I understand a ion pump could help me go to my UHV objective (10^-11 to 10^12 after propoer backing the Chamber).... So the setup for my needs is : A dry scrull pump + TMP pump + Ion Pump... Is that correct ? 22-Aug-19 07:22 AM As understand this Ion Pump from Agilent Graph 22-Aug-19 07:22 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/chart-pu-gammaion25s-45s_01-34DF7.svg 22-Aug-19 07:24 AM doesn't have to be a dry scroll, but that's pretty much it 22-Aug-19 07:56 AM Correct. To achieve -11 or -12 levels you will need a baked system after the TMP and all metal to metal sealing (no O rings or elastomers of any kind if possible, or greases in general) and some kind of ion or getter pump. Once the system is verified leak free (both real and virtual leak) after a long period in that state the main valve can be closed and the ion or getter pump can continue to achieve and maintain the final vacuum level. You could also leave the main pumps running but eventually your ion pump or whatever else you are using will need to be regenerated. 22-Aug-19 07:59 AM Any huge difference between cryo and getter? 22-Aug-19 07:59 AM cryo is a higher investment to begin with, but they don't need to be regenerated, right? 22-Aug-19 08:03 AM Cryo has the highest pumping speeds of any pump 22-Aug-19 08:03 AM If you want very fast pumping with high gas loads and uhv, cryo is better 22-Aug-19 08:03 AM Probably overkill for small systems, ion traps wouldn't need high pumping speed 22-Aug-19 08:03 AM Once down to uhv levels, ion pumps will last a very long time running continuously with minimal gas loads 22-Aug-19 08:03 AM Getter and cryo also pump differently for different gases 22-Aug-19 08:06 AM right, cryo doesn't care if your gas is noble 22-Aug-19 08:07 AM Cryo struggles with H2 and He though 22-Aug-19 08:07 AM How about He in a getter? 22-Aug-19 08:07 AM it would not react with the getter material, but maybe just physically implanted in it? 22-Aug-19 08:07 AM Getter pumps can provide higher ultimate vacuum than cryo, especially non evaporable getter (NEG) 22-Aug-19 08:08 AM oh, ok 22-Aug-19 08:08 AM I think in that case NEG is the best bet 22-Aug-19 08:08 AM Evaporable Ti sublimation pumps react with the gases. H2 is fine, not sure it's pumping efficiency with He 22-Aug-19 08:08 AM A plus about ion pumps is there are different ones available for different gases 22-Aug-19 08:08 AM Noble diode will do better with things like He, diode is good for general purpose, star cell is kind of a mix between the two 22-Aug-19 08:08 AM For more advanced stuff like NEG, you can buy the elements, but it's probably not cheap, though to be fair, any UHV is not going to be cheap, unless you maybe find a very good condition pump for free from somewhere 22-Aug-19 08:56 AM i have seen replacement "15K assemblies" for cryopumps. Under wich circumstances do they have to be replaced? 22-Aug-19 08:56 AM at some interval or only if something goes wrong? 22-Aug-19 08:58 AM well you've seen mine :D 22-Aug-19 08:59 AM did i? 22-Aug-19 08:59 AM i cant remember 22-Aug-19 08:59 AM oh waet, wrong person 22-Aug-19 08:59 AM xD 22-Aug-19 09:00 AM question is, does the activated charcoal on there get saturated regularly or just when something goes seriously wrong 22-Aug-19 09:01 AM I thought the whole point is to saturate it, hence the thermal Regeneration with a heater 22-Aug-19 09:02 AM saturate in such a way you cant regen 22-Aug-19 09:03 AM ah 22-Aug-19 09:05 AM oxygen saturated charcoal? 22-Aug-19 09:05 AM jk 22-Aug-19 09:05 AM @yann35 and a full metal valve for the final isolation of the chamber + IGP or whatever would be nice too 22-Aug-19 09:09 AM IGP ? 22-Aug-19 09:10 AM Ion Getter Pump 22-Aug-19 09:10 AM like those varian starcell pumps you've referenced 22-Aug-19 09:14 AM Charcoal cryo pumps have practical limits well above where you want to be. There are better sieve materials available for that use. 22-Aug-19 09:14 AM and for noble gases tantalum cathods are handy 22-Aug-19 09:15 AM Remember that noble gasses will ion implant quite well so diode pumps are very good for that 22-Aug-19 09:15 AM Arghh. Brain fart 22-Aug-19 09:15 AM Noble diode pump. 22-Aug-19 09:18 AM yeah, with tantalum cathods 22-Aug-19 09:18 AM titanium ... not so good 22-Aug-19 09:18 AM with titanium only you will get funny noble gas oscillations 22-Aug-19 09:18 AM pressure peaks 22-Aug-19 09:21 AM Thanks all for your advices !!! Great group of vacuum hacker 22-Aug-19 09:21 AM I have some titanium and tantalum wire just for this use. Never bothered to build up a system to use them though 22-Aug-19 09:21 AM I also have some small unused varian style ion pumps. Cute little suckers that fit in your hand. 22-Aug-19 09:23 AM yep for tiny chambers perfect 22-Aug-19 09:23 AM They would be very easy to duplicate. 22-Aug-19 09:23 AM In other news I have some spun stainless steel parts inbound I found cheap on amazon. They looked just right to use for a small single stage diffusion pump. Never built my own pump before so I think I might give it a try. I was looking at some nickel plated brass sink drain tails thinking they would be great pump bodies and cheap as heck from Home Depot. 22-Aug-19 09:28 AM heh yeah, a fire powered diffusion pump 22-Aug-19 09:28 AM hell yeah 22-Aug-19 09:28 AM for outdoor vakuum fun 22-Aug-19 09:28 AM doesn't have to be outdoor 22-Aug-19 09:28 AM just a small bunsen burner 22-Aug-19 09:28 AM for the real lab a e s t h e t i c s 22-Aug-19 09:29 AM for the instagrams!11 22-Aug-19 09:29 AM just for the instagrams! 22-Aug-19 09:29 AM ok but ... cooling with the water from a mountain stream 22-Aug-19 09:29 AM please, twitters 22-Aug-19 09:29 AM ok, twitters and yts 22-Aug-19 09:29 AM better 22-Aug-19 09:29 AM pure fresh nature + a diffusion pump :> 22-Aug-19 09:30 AM right, cooling is important 22-Aug-19 09:30 AM for the green, bio vacum 22-Aug-19 09:30 AM runs with rapeseed oil 22-Aug-19 09:30 AM or soy oil 22-Aug-19 09:30 AM wasn't santovac made from soy oil? or fomblin? 22-Aug-19 09:30 AM (just kidding) 22-Aug-19 09:31 AM :D 22-Aug-19 10:11 AM There's a really easy way to get to -12 22-Aug-19 10:11 AM Launch into deep space with an e-beam welder, a bakeout oven, and some polished stainless. 22-Aug-19 10:11 AM :D 22-Aug-19 10:11 AM I wonder what pumping speed deep space has... 22-Aug-19 11:06 AM sooo... uhm... don't mind me, i'm just cleaning my vacuum hoses 22-Aug-19 11:06 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_8913-5A755.JPG 22-Aug-19 11:08 AM heh, reminds me of when I got my iso 100 valve 22-Aug-19 11:08 AM once I was done vacuuming (not the kind this server is about) it it was time for the pressure washer as well 22-Aug-19 11:09 AM oh, and i just cleaned the vessels to freeze the cum samples, too 22-Aug-19 11:09 AM ...that sounds wrong 22-Aug-19 11:09 AM the vessels for our big dewar. 22-Aug-19 11:09 AM we all know how you meant it 22-Aug-19 11:09 AM which makes it even worse 22-Aug-19 11:09 AM tbh I'm surprised dyno doesn't complain 22-Aug-19 11:12 AM maybe he's broken? 22-Aug-19 11:13 AM nope still works 22-Aug-19 11:13 AM xD 22-Aug-19 11:13 AM ahahahaha 22-Aug-19 11:13 AM nice. 22-Aug-19 11:27 AM I wonder if short bellows gas hoses would be a cheap suitable replacement for forevacuum lines 22-Aug-19 11:27 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/2-48574.png 22-Aug-19 11:27 AM This kind 22-Aug-19 11:28 AM @AdamMcCombs the machine has landed 22-Aug-19 11:28 AM hooray! 22-Aug-19 11:28 AM no 30 min call before hand.. I was actually giving hte dog a bath when the call came saying he was rihgt here 22-Aug-19 11:28 AM now you get to disassemble and clean every bit of it 22-Aug-19 11:28 AM right 22-Aug-19 11:28 AM more so to transxport.. but yeah, looking over the manual now 22-Aug-19 11:28 AM The eagle has landed! 22-Aug-19 11:31 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0539-C26DF.JPG 22-Aug-19 11:32 AM @Deleted User thought about that too. you can even get "wellschlauch" (corrugated tube?) on ebay in stainless in any length and diameter you want... and turning the KF-pieces for the ends is no problem... i just need a passable TIG machine. 22-Aug-19 11:32 AM just braze it 22-Aug-19 11:32 AM silver solder 22-Aug-19 11:33 AM hmm, could definitely try that 22-Aug-19 11:33 AM maybe with the leftover pieces from the cut hose i have 22-Aug-19 11:33 AM do you have some silver solder left over? 22-Aug-19 11:35 AM well someone wanted to give me some at the stammtisch... 22-Aug-19 11:35 AM same stuff we brazed those aeroquip adapters with so you see it works well 22-Aug-19 11:36 AM works for thick stuff at least 22-Aug-19 11:36 AM we'll see what it does for thin walled tubing 22-Aug-19 11:37 AM I'd assume it will create less holes than TIG welding 22-Aug-19 11:37 AM I think the standard "wellschlauch" is for cables 22-Aug-19 11:37 AM The non-solid stuff 22-Aug-19 11:37 AM That can split easily 22-Aug-19 11:37 AM But there's propane corrugated tube 22-Aug-19 11:37 AM wait a second, just looking for the link 22-Aug-19 11:38 AM https://giphy.com/gifs/link-reaction-gifs-fe3NDdz8tl6Vwm4xbr 22-Aug-19 11:40 AM not that one 22-Aug-19 11:40 AM didn't find the link, but i just found out there's corrugated tube for solar applications 22-Aug-19 11:40 AM will buy a meter or two of that stuff and just play around 22-Aug-19 11:40 AM if i find that link again. 22-Aug-19 11:41 AM don't you have some lengths of holy tubing? 22-Aug-19 11:43 AM no, no priests were involved in the making 22-Aug-19 11:44 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0540-F0FFC.JPG 22-Aug-19 11:44 AM Rustier than I pictured, but mostly all moveable 22-Aug-19 11:44 AM A little damage, but mostly functional 22-Aug-19 11:58 AM awesome! 22-Aug-19 11:58 AM and I'm still amazed at what you've done to your camera 22-Aug-19 11:59 AM Took like 4 years to get the camera to be vintage 22-Aug-19 12:00 PM now brand it "instagram" and sell it for 4x its value! 22-Aug-19 12:06 PM Tumblr 22-Aug-19 12:19 PM Spotted the rare and elusive @AdamMcCombs in his natural environment 22-Aug-19 12:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_2244-7F08B.JPG 22-Aug-19 12:21 PM that's a weird looking SEM 22-Aug-19 12:23 PM I see a turbo 22-Aug-19 12:26 PM It's my little baby SEM 22-Aug-19 12:27 PM whaaa 22-Aug-19 12:27 PM how cute ❤ 22-Aug-19 12:28 PM Adam said it was cute, and then proceeded to tell me how lame it was compared to a "real" SEM. 22-Aug-19 12:28 PM well you can't have everything, can you? 22-Aug-19 12:30 PM i definitely thought that was a weird modded computer case at first 22-Aug-19 12:31 PM with turbopump vacuumcooling... no, wait 22-Aug-19 12:32 PM turbo for an insulating vacuum for the cryocooler on the CPU 22-Aug-19 12:32 PM ohhhhh 22-Aug-19 12:32 PM overclocking at -196°C 22-Aug-19 12:32 PM with bad insulation, air condensing on the outside of the modded case 22-Aug-19 12:33 PM @Conmega s head could easily cool a medium sized CPU 22-Aug-19 12:33 PM and if that's not enough you just take one of those 600 W thingies 22-Aug-19 12:40 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0541-B9190.JPG 22-Aug-19 12:40 PM Table pivots fine. 22-Aug-19 12:54 PM If your SEM sucks, I'll trade it for a large vintage sem 22-Aug-19 12:54 PM You pay shipping, I just buy you a new surplus SEM :P 22-Aug-19 12:55 PM @Deleted User @Pan Da @GigaSquirrel Brazing works fine, i repaired some hoses this way, absolutely trouble free 22-Aug-19 12:55 PM welding sucks big time 22-Aug-19 12:55 PM sucking big time is generally the idea of what we build here 22-Aug-19 12:56 PM repaired helium lines this way because for some reason i was to stupid to remember brazing even existed while the brazing stuff was laying next to me in the drawer 22-Aug-19 12:56 PM Hehe 22-Aug-19 12:56 PM when i hose is broken just push it together so the bumps make contact and then flow them together, works beautifully, should definetly work with flanges too 22-Aug-19 12:56 PM just remembered i have a hose with a carpton of holes in it somewhere, i will cut the ends off as soon as i will revist my scrapyard to get some new corrigated pipe 22-Aug-19 01:12 PM tell me the diameter, we could save shipping costs if i ordered your hose in the same process as mine 22-Aug-19 01:21 PM im fine with trash 22-Aug-19 01:21 PM have enough vac tubing anyways 22-Aug-19 01:21 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/zwischenplatte_montiert1-2A2D0.jpg 22-Aug-19 01:21 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/zwischenplatte_montiert2.jpg-6C131.jpg 22-Aug-19 01:21 PM first part of the gm taking shape 22-Aug-19 01:21 PM i hope tomorrow will be more productive... 22-Aug-19 01:27 PM what's the stepper for? 22-Aug-19 01:27 PM valve drive 22-Aug-19 01:27 PM makes everything much much more compact 22-Aug-19 01:30 PM your machining a GM? 22-Aug-19 01:30 PM I'd just buy a used one for like 50-150 bucks if you really want one... There are so many of them all over the place. Even if you find one that is shot you could at-least rebuild it yourself machining new parts if that's what you want to do. 22-Aug-19 01:30 PM But if you just like the idea of machining it, hey go for it! 22-Aug-19 01:32 PM he already has... three? 22-Aug-19 01:32 PM maybe 4 22-Aug-19 01:32 PM oh lol didn't know :P 22-Aug-19 01:32 PM but none that fits his dewar just right 22-Aug-19 01:32 PM Sorry I'm not Google 22-Aug-19 01:32 PM I don't know everyone's life :P 22-Aug-19 01:32 PM ah lol 22-Aug-19 01:33 PM dunno if you saw my liquifier pics / videos on twitter, not the head I repaired but the ones before 22-Aug-19 01:33 PM that's his 22-Aug-19 01:35 PM ah 22-Aug-19 01:35 PM ok 22-Aug-19 01:35 PM @Conmega yep, when you live in the US you can get them for free, sadly not around here ^^ 22-Aug-19 01:35 PM the ones i have are up to 10w @77K wich is by far to small for what my compressor can supply 22-Aug-19 01:35 PM for kind of economical liquid air production i want a single stage one between 50 and 60W @ 77K 22-Aug-19 01:39 PM Yea I got a compressor and 60W head paired up at surplus here for 130~ bucks 22-Aug-19 01:39 PM now I needed to drive half way across the country to get it 22-Aug-19 01:39 PM So with fuel tolls and time it was more... 22-Aug-19 01:41 PM still a very good deal 22-Aug-19 01:41 PM http://www.tekservakum.com/wp-content/uploads/2016/11/Yuksek_Vakum_182_54_02_COOLPOWER_MD_EN.pdf 22-Aug-19 01:41 PM thats ... impressive 22-Aug-19 01:41 PM by the name i expected the 10 to have 10W 22-Aug-19 01:42 PM https://www.cryoandmore.de/partners-and-products/cryomech/gifford-mcmahon-cryorefrigerators/ 22-Aug-19 01:42 PM not 110... 22-Aug-19 01:42 PM dang 22-Aug-19 01:42 PM yeah i know 22-Aug-19 01:42 PM but these ones look tiny 22-Aug-19 01:42 PM AL600 22-Aug-19 01:42 PM omg 22-Aug-19 01:42 PM https://www.ebay.de/itm/Cryogenic-System-mit-zeistufigem-Kaltkopf-Coolpower-10-MD-von-der-Firma/254333832298?hash=item3b377a4c6a:g:OEIAAOSw53dc7u~5 22-Aug-19 01:42 PM dont want to spend the money at this point but that would be a sweet deal still 22-Aug-19 01:43 PM I mean you can always wait it out 22-Aug-19 01:43 PM a pretty much brand new 110W/18W head 22-Aug-19 01:43 PM if its up for a long while you might be-able to offer a bit less 22-Aug-19 01:43 PM some people are motivated to move stuff after it sits around for too long 22-Aug-19 01:43 PM i dont expect it to go below 1k and keeping in mind i have 3 working ones... 22-Aug-19 01:43 PM if i knew what this thing was for... 22-Aug-19 01:43 PM except for obvious stuff like the mfc i have no idea what components there are that would be worth reselling 22-Aug-19 01:46 PM yea I dunno, it looks like he took the cover off some varian box 22-Aug-19 01:46 PM might be-able to find a model number 22-Aug-19 01:46 PM might be as simple as the same product idea that my device is 22-Aug-19 01:46 PM an air cooler basically lol 22-Aug-19 02:14 PM meh, after all my compressor is to small for this behemoth and i dont need liquid air that bad 22-Aug-19 02:14 PM its a definete want to have but no need 22-Aug-19 10:12 PM Decided to buy an MKS 901P gauge 22-Aug-19 10:12 PM Wider range than my PPT-100, and I can implement another protocol into my vacuum reader(they're both analog and RS232/485)! 22-Aug-19 10:12 PM Super cheap too, only $40 for a working unit. 22-Aug-19 10:29 PM ayo, so, update.. got the table inside with help from some buddies nearby.. going to work on getting the main work head off tomorrow.. which will t hen leave the base... a few ideas for that, but basically lighten the load as much as possible, fist 22-Aug-19 10:30 PM Spirit, the range of the 901P is a bit of a lie... depending on which spec your looking at 22-Aug-19 10:30 PM if you read the manual the whole down to 1x10^-5 thing is not true... it can logically send that over serial, but it really only goes down to like somewhere in the 5x10^-4 and even thats pushing it a bit. 22-Aug-19 10:30 PM I have dug into the 901p quite a bit since my gauge controller uses that for a pirani and uses the activeline for the HV/UHV range 22-Aug-19 10:30 PM https://i.imgur.com/CIVMysc.jpg 22-Aug-19 10:30 PM there is the prototype of that guy 22-Aug-19 10:30 PM I can't seem to find a photo of the first prototype board I made 22-Aug-19 10:30 PM Ah wait here we go 22-Aug-19 10:30 PM https://i.imgur.com/3h2bSEp.jpg 22-Aug-19 10:30 PM So yea, have the second prototypes out on order now 22-Aug-19 10:30 PM which adds the SAR ADC for the activeline stuff 22-Aug-19 10:30 PM And yes the 901Ps are great pirani gauges for the money, always available around 40-50 bucks and generally in good shape too, highly reccomended for the RS232 interface, and free (albeit bad) software. 22-Aug-19 10:45 PM I really like the Pfeiffer protocol 22-Aug-19 10:45 PM At first it hits you like a wall of bricks, but then you realize it's actually fairly elegant 22-Aug-19 10:45 PM I'll probably be using a 24-bit delta-sigma ADC for the system 22-Aug-19 10:45 PM just to get that extremely unnecessary extra resolution 22-Aug-19 10:52 PM Uhm, your going to be lucky to get a clean enough signal to at that resolution, anything above like 12 and you start getting into crazy board layout territory and needing highly precise parts 22-Aug-19 10:53 PM Not really, 24 bits is fairly doable 22-Aug-19 10:53 PM I am using this part 22-Aug-19 10:53 PM http://www.ti.com/lit/ds/symlink/ads8866.pdf 22-Aug-19 10:53 PM I'm experienced enough to know that I can get "24 bits" of resolution(ignoring SNR and DR) 22-Aug-19 10:53 PM But the gauges output a helluva lot more noise and a lot less data than 24 bits 22-Aug-19 10:53 PM Despite being analog 22-Aug-19 10:53 PM I think I'm going to be using an ADS131M04 22-Aug-19 10:53 PM It's cheap, has multiple channels, and a good enough SNR to shave off ~6 bits into oversampling to get stable values 22-Aug-19 10:59 PM But with Sigma Delta you can get bits for cheap but your absolute values aren't precise, only your steps are... So its probably not the right part to go for... This is why I choose SAR personally. 22-Aug-19 10:59 PM I guess you could calibrate it? but thats extra trickery to deal with 22-Aug-19 11:00 PM The values aren't massively off 22-Aug-19 11:00 PM those 6 bits would "calibrate" it 22-Aug-19 11:02 PM To do proper oversampling wouldn't you need dithering and then you'd need a better signal but yea... Over 12 bits it gets difficult. I dunno. I learned most of what I know from a guy who has like 40 years experience in the EE space. He has worked with ADCs for quite awhile. You can do anything but yea just a matter of if its worth the effort/time. 22-Aug-19 11:04 PM I doubt there will be more than 12 bits of actual data coming from any gauge anyway 22-Aug-19 11:04 PM And even if there is, the tolerances are WILD on most of them 22-Aug-19 11:04 PM Except maybe capacitance transducers, for doing precise gas work 22-Aug-19 11:04 PM And MFC monitor outputs 22-Aug-19 11:05 PM Again, best to use a SAR in this application, I choose the part I choose since its sudo differential allowing you to take account for the signal ground and its cheap. 22-Aug-19 11:05 PM But hey, go for it, give whatever a try I say 22-Aug-19 11:05 PM Differential input doesn't matter here 22-Aug-19 11:05 PM Just reference the signal ground to ground 22-Aug-19 11:06 PM uhm lol wut 22-Aug-19 11:06 PM if ground didn't matter multimeters would just have one lead :P 22-Aug-19 11:06 PM The output is 0-10 on most 22-Aug-19 11:07 PM ground carries current remember. 22-Aug-19 11:07 PM I think you're underestimating how much I know by just a bit :P 22-Aug-19 11:08 PM I don't know what you know, I just know the guy I am talking to right now knows a hell of a lot more than I ever probably will lol. 22-Aug-19 11:08 PM Differential inputs aren't required here, single-ended is just fine, and if you ground the negative input you're turning it into a single-ended amp regardless 22-Aug-19 11:08 PM Sorry, brainfart, not amp, ADC 22-Aug-19 11:12 PM That's correct but not what you want, if you take a multi meter, measure at the signal ground at your controller, and the signal ground at the gauge you will measure a small voltage because there is a current flowing there... It is significant. Why would they put a signal ground there if it wasn't necessary and why would the put a massive warning not to connect power ground to the signal ground if it wasn't significant? 22-Aug-19 11:13 PM For twisted-pair reading from a gauge that is not a power supply and not referenced to ground 22-Aug-19 11:13 PM You can clamp the signal ground at your board with some diodes to ensure it doesn't drift past zero too much, something I had to do since this ADC is a single ended effectively with the differential input to account for this current. But yea... Its significant if you want any decent resolution. 22-Aug-19 11:14 PM For gauges with signal grounds I'd probably do a differential voltage follower input 22-Aug-19 11:14 PM I think in my design I'll just do that for all inputs, with a jumper to optionally short signal ground to ground if it's not present on the sensor 22-Aug-19 11:18 PM Well give it a go, I'll be interested to see your controller and progression, if your planning on 4 gauges of control thats pretty nice, this is just going to be a single pirani and single activeline gauge 22-Aug-19 11:19 PM a 4-gauge analog input module should be enough 22-Aug-19 11:19 PM plus another 4 digital... I guess? 22-Aug-19 11:19 PM Going to be a heck of a micro for that :) 22-Aug-19 11:19 PM Unless your chaining SPI stuff for everything I suppose 22-Aug-19 11:19 PM I am using two UARTs and an SPI currently on my chip 22-Aug-19 11:20 PM chip selects are a magical thing 22-Aug-19 11:20 PM or enables 22-Aug-19 11:20 PM well sure for SPI 22-Aug-19 11:20 PM most chips have them 22-Aug-19 11:20 PM I suppose you could do that on RS232 as-well 22-Aug-19 11:20 PM Suppose I wasn't super concerned about cost cutting the board by a buck on the micro 22-Aug-19 11:22 PM The controller will be split into modules with their own brains 22-Aug-19 11:22 PM And I'm thinking they'll communicate either via SPI, I2C, or just RS485 22-Aug-19 11:23 PM Multiple micros talking to eachother? 22-Aug-19 11:23 PM yeah, separate modules for stuff 22-Aug-19 11:23 PM analog gauge module, digital gauge module, relay module for doing stuff 22-Aug-19 11:24 PM I mean I just used one micro talking to everything, I made each device its own little area on the board but yea 22-Aug-19 11:24 PM I'm planning on making it a completely modular design to expand in the future 22-Aug-19 11:25 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-ECA04.png 22-Aug-19 11:25 PM thats whats out to fab atm 22-Aug-19 11:25 PM So many missing ground planes :P 22-Aug-19 11:25 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-532FB.png 22-Aug-19 11:25 PM You were saying GND? 22-Aug-19 11:26 PM The bottom is filled, the top isn't 22-Aug-19 11:26 PM Looking nice though 22-Aug-19 11:26 PM top is filled around devices for the most part, and stitching areas of the bottom ground where it has to run through some thinner sections 22-Aug-19 11:27 PM What's driving the relays? 22-Aug-19 11:27 PM those come from the MKS-901P 22-Aug-19 11:27 PM It has built in relays 22-Aug-19 11:27 PM Ah 22-Aug-19 11:27 PM thats simply wiring them out from the DE15 22-Aug-19 11:27 PM thus the warning of the limitation of those relays on the board 22-Aug-19 11:28 PM I think I'll make both my turbo controller and the vacuum station dingus arduino-compatible 22-Aug-19 11:28 PM To make them easier to extend 22-Aug-19 11:28 PM And to make me do less work because I'm lazy 22-Aug-19 11:29 PM Easier to bloat* lol 22-Aug-19 11:29 PM arduino libraries are just soooo slow and for the most part bad... also the Arduino IDE just eugh 22-Aug-19 11:29 PM yea I just used MSP430, its nice having live in circuit debugging 22-Aug-19 11:29 PM has helped all way too much 22-Aug-19 11:30 PM Who cares about speed when you're running the whole thing at 72MHz :P 22-Aug-19 11:30 PM hah... right you mean like 12Mhz after all the ram waitstates? 22-Aug-19 11:30 PM I admit I've fallen into the convenience trap all too often 22-Aug-19 11:30 PM you should poke around the STM32 datasheets a bit :P 22-Aug-19 11:30 PM and mhz is not what matters remember 22-Aug-19 11:30 PM But with modern chips you don't have to squeeze kilobytes and cycles 22-Aug-19 11:30 PM there are a LOT of variables 22-Aug-19 11:30 PM sure 22-Aug-19 11:30 PM you say that... 22-Aug-19 11:31 PM There's HUGE amounts of free space if you do it correctly 22-Aug-19 11:31 PM but either way, use what tools your comfortable with 22-Aug-19 11:31 PM Arduino-compatible doesn't have to mean only stock arduino code, you know :P 22-Aug-19 11:32 PM sure if you utilize the rams/roms/etc all nicely but using the arduino IDE makes it a pain to map all that nicely 22-Aug-19 11:32 PM And spreading the work load over multiple small chips is fairly easy 22-Aug-19 11:32 PM The main device only handles sending and receiving data, displaying it and interacting with the UI 22-Aug-19 11:32 PM The modules do the sampling and get the data ready 22-Aug-19 11:33 PM just a silly way to do it since one micro can easily do it all if you write it well 22-Aug-19 11:33 PM and don't use digitalread/write 22-Aug-19 11:33 PM lol 22-Aug-19 11:33 PM It's still fine for most applications 22-Aug-19 11:33 PM Including this 22-Aug-19 11:33 PM And I don't think it's silly, since it's infinitely extensible, more or less 22-Aug-19 11:33 PM Need more IOs? Make just a module and add in support for some extra commands, rather than respinning the entire thing 22-Aug-19 11:33 PM Found a funny gauge that speaks a proprietary protocol? Just another module. 22-Aug-19 11:34 PM also you realize there probably isn't a library for your ADC... 22-Aug-19 11:35 PM I'm not that much of a lemon 22-Aug-19 11:35 PM Only slightly 22-Aug-19 11:35 PM I can write libs 22-Aug-19 11:35 PM I just really dislike doing that 22-Aug-19 11:35 PM uhm 22-Aug-19 11:35 PM thats like 90% of the work 22-Aug-19 11:35 PM 10% is putting the libraries together 22-Aug-19 11:35 PM also using libraries inheriently means you pick up other people's bugs lol 22-Aug-19 11:35 PM The ADCs all talk some sort of serial protocol 22-Aug-19 11:36 PM which then you don't understand the library and have fun debugging it 22-Aug-19 11:36 PM Right... but a libraries job is to set up the local side SPI interface, then setup the control registers in the ADC then do the reading/wriiting of that data 22-Aug-19 11:36 PM Which is also going to use existing libraries 22-Aug-19 11:36 PM I dunno doing the gauge I did took me a solid week of code development to get where I was and that was with significant help 22-Aug-19 11:36 PM no it won't? 22-Aug-19 11:36 PM lol I wrote all my libraries from scratch 22-Aug-19 11:37 PM Took me two days to develop the entire single-gauge reader 22-Aug-19 11:37 PM only libraries I used were the TI libraries that mapped registers 22-Aug-19 11:37 PM thats it 22-Aug-19 11:37 PM We ended up at the same result but what a time difference 22-Aug-19 11:38 PM same result huh? so what licenses do you use? mine I can license any way I want? also you got lucky with grabbing libraries and taping them together, I have been bitten by libraries before causing weeks of debug to find out the library was the broken thing 22-Aug-19 11:39 PM I have been too, and I only used the standard arduino libs to get me through the boring setup 22-Aug-19 11:39 PM So licensing is free 22-Aug-19 11:39 PM Sometimes it's all about the end result 22-Aug-19 11:39 PM you seem to misunderstand the size of those libraries, also licensing isn't meaning what you think it means, I mean what license does your code HAVE to fall under now? MIT, GPL? 22-Aug-19 11:40 PM MIT, all of it 22-Aug-19 11:40 PM Also how do you measure performance in this case, how is the result the same? 22-Aug-19 11:40 PM I look at the screen and see a gauge reading 22-Aug-19 11:40 PM And I can output it via USB to a PC to log it 22-Aug-19 11:40 PM This seems silly to try and objectify to what comes out to a bragging competition which isn't the point here. I am just discussing a project. 22-Aug-19 11:40 PM I am just discussing my experiences and opinions 22-Aug-19 11:41 PM My point is, libraries and abstraction aren't something to completely run away from 22-Aug-19 11:41 PM I don't care what or how you do something, I spent this project to learn, and that's what I did. 22-Aug-19 11:41 PM I can't put "Arduino pro" on my resume but I can put "Knowledge in programming C for the MSP430 family of microcontrollers" 22-Aug-19 11:41 PM I wouldn't say it is either 22-Aug-19 11:41 PM but I would just say to seperate them into something that is a fun hobby thing to throw together and something that you want to control thousands of dollars of equipment 22-Aug-19 11:41 PM would you trust an Arduino to put you into space? 22-Aug-19 11:43 PM I can put "Moderately competent in C/C++ across a wide range of platforms" on my resume, but this is a hobby thing 22-Aug-19 11:43 PM I wouldn't trust an arduino to put me across town if I couldn't kill it with a big red button 22-Aug-19 11:43 PM But for what I'm doing, I'm happy with what it does, because I just got to a result without dwelling on writing all of my own code 22-Aug-19 11:44 PM Its just kinda insulting to sit here and tell me that 2 days of putting together arduino libraries and learning how to program a microcontroller in C and writing all custom libraries for UART/SPI/Display graphics libraries/etc is the complete same thing and what I did was stupid. 22-Aug-19 11:44 PM If I were developing a product, I sure as hell wouldn't put an arduino in there 22-Aug-19 11:44 PM conmega, just because you link into MIT code doesn't mean you have to license your code as MIT. that only applies to (A)GPL 22-Aug-19 11:44 PM I'm not saying it's the same amount of effort 22-Aug-19 11:44 PM But the result, for all intents and purposes, is the same 22-Aug-19 11:45 PM @taktoa I understand this, there are license contigencies with just writing something using TI's base libraries too, but the point was to be careful just picking up random libraries 22-Aug-19 11:45 PM I was going for the result, you were going for the process and learned more 22-Aug-19 11:46 PM This is something I am developing along with someone to sell as a product, so its kind of a different thing, this started by Adam needing something for a certain price for a client. This is why I am doing multiple prototypes and learning from mistakes and really having people review my work and testing for code reliability. 22-Aug-19 11:46 PM In that case I'd go closer to your route 22-Aug-19 11:46 PM Either way, I think its great to go and hack on something, I just think everyone should strive for greater learning and arduino is a great starting place for beginners, and I started there myself 22-Aug-19 11:47 PM Though I'm more experienced with AVR and STM32 22-Aug-19 11:47 PM but if you already know code and board design, I'd say to challenge yourself 22-Aug-19 11:47 PM I just wanted it done quickly, and already existing boilerplate code is the way to achieve that 22-Aug-19 11:47 PM Fair enough 22-Aug-19 11:48 PM Get excited for the certification process if you're selling it :P 22-Aug-19 11:49 PM Heh this is not going to be a product of quite that scale... 22-Aug-19 11:49 PM Though I know people with certification labs 22-Aug-19 11:49 PM I believe the FCC care about that if you're actually doing the full business thing 22-Aug-19 11:49 PM Not entirely sure as I'm not from the US 22-Aug-19 11:50 PM I think it really depends, my one friend has been selling boards for years, as kits for hobbiests and to clients who run entire silicon production lines 22-Aug-19 11:50 PM Kits definitely don't fall under that 22-Aug-19 11:50 PM I remember that for sure 22-Aug-19 11:50 PM It's complete products that can run and require no significant assembly 22-Aug-19 11:51 PM Well the ones he sells to big clients are fully assembled and he installs them on site and such 22-Aug-19 11:51 PM So... uh... put a 0-ohm jumper in there and include it in the kit unsoldered. 22-Aug-19 11:51 PM * some assembly required 22-Aug-19 11:51 PM :P 22-Aug-19 11:51 PM well this is a card that just plugs into a PC and works 22-Aug-19 11:51 PM so I mean I dunno if that constitutes that or not but yea 22-Aug-19 11:51 PM I'm joking 22-Aug-19 11:51 PM A jumper won't qualify as a kit 22-Aug-19 11:51 PM I know 22-Aug-19 11:52 PM But a PC card will definitely require some sort of certification 22-Aug-19 11:52 PM But if you're just selling it to a couple guys and one company, it shouldn't be too much trouble 22-Aug-19 11:52 PM Even if you just run a basic EMC compliance test and don't get the actual expensive certification 22-Aug-19 11:52 PM I thought the major thing the FCC cared about certification for was devices that do any kind of wireless communications 22-Aug-19 11:52 PM since then your broadcasting which can cause major issues if not implemented correctly 22-Aug-19 11:53 PM Wireless is a separate rabbit hole of its own 22-Aug-19 11:53 PM But there's loopholes, such as using pre-certified modules 22-Aug-19 11:53 PM But all products, even those that don't broadcast intentionally, have to be certified pretty much everywhere in the world 22-Aug-19 11:54 PM Yea I dunno what the requirements are. But either way this is all small product, he keeps track of all sales and does his taxes I think the Government is happy enough about that 22-Aug-19 11:54 PM (if you're planning to sell in that part of the world) 22-Aug-19 11:54 PM It probably doesn't matter for a small product that won't sell more than a handful of copies 22-Aug-19 11:54 PM Otherwise the FCC would show up with party vans to every single radio amateur's home 22-Aug-19 11:54 PM (or most of them anyway, I've seen everyone sell something) 22-Aug-19 11:54 PM The EEVBlog forum has some nice threads about EMC compliance and certification 22-Aug-19 11:58 PM I thought most of the "certifications" were just stuff that companies care about, not necessarily government agencies, except for silly interference or actual wireless transmission. 22-Aug-19 11:58 PM the regulations are silly complex though so you'd just hire someone to tell you what you need/don't need really 22-Aug-19 11:59 PM Those CE, FCC, TUV marks on everything? They mean the device is actually certified 22-Aug-19 11:59 PM (unless it's cheap and comes from China, in which case CE means China Export) 22-Aug-19 11:59 PM And yeah, compliance is fairly complex 23-Aug-19 12:01 AM a lot of certifications are required for EU apparently they are sticklers lol 23-Aug-19 12:01 AM Not a lot 23-Aug-19 12:01 AM But there's plenty of overlap 23-Aug-19 12:01 AM You do your own pre-compliance in house(conducted, radiatied emissions, sensitivity, all that stuff), once you think it's good, you pay an actual certification house to do fully certified and registered testing, and then hand you an official cert 23-Aug-19 12:01 AM And then you're legally allowed(sometimes required) to slap CE, FCC, TUV, and other marks 23-Aug-19 12:01 AM TÜV is German, so that mostly covers the EU 23-Aug-19 12:01 AM In theory, you can also just put the FCC mark on your product, they won't actively buy one and test it to catch you red-handed, but it's a declaration of conformity, so if you don't conform and have a label that says otherwise, that's when the troubles start. 23-Aug-19 12:01 AM You need an actual certificate of conformity for the mark to be legitimate, and there's many many companies that are accredited to actually issue them. 23-Aug-19 12:06 AM So apparently stuff like computer peripherals that go in the computer minus the PSU/CPU board don't need certification so long as the rest of the system is certified? 23-Aug-19 12:06 AM but its loose terms and such 23-Aug-19 12:06 AM I believe it's the opposite 23-Aug-19 12:06 AM The PC doesn't have to be certified, but the parts inside do 23-Aug-19 12:06 AM I have the FCC laws up in front of me 23-Aug-19 12:06 AM (e) Subassemblies to digital devices are not subject to the technical standards in this part unless they are marketed as part of a system in which case the resulting system must comply with the applicable regulations. Subassemblies include: 23-Aug-19 12:06 AM It's something about "assembled out of individually certified parts" 23-Aug-19 12:06 AM But if it's for a specific client or select people and it's not a publicly sold product, plainly speaking, you don't care about any of this at all 23-Aug-19 12:07 AM Devices that are enclosed solely within the enclosure housing the digital device, except for: Power supplies used in personal computers; devices included under the definition of a peripheral device in § 15.3(r); and personal computer CPU boards, as defined in § 15.3(bb); 23-Aug-19 12:07 AM (unless it has the potential to cause damage or harm) 23-Aug-19 12:07 AM But again I am not a lawyer so 23-Aug-19 12:07 AM Refer to the above 23-Aug-19 12:07 AM ¯\_(ツ)_/¯ 23-Aug-19 12:08 AM I'm not a lawyer either 23-Aug-19 12:08 AM And I live on the other side of the world 23-Aug-19 12:08 AM part 15 is the right document, that's all I know 23-Aug-19 12:08 AM there's also 18 but I don't remember what that's about 23-Aug-19 12:09 AM Ah so... 23-Aug-19 12:09 AM with devices that are unintentional radiators 23-Aug-19 12:09 AM most of them can be certified with a real Certification or the following: Supplier’s Declaration of Conformity (SDoC) is a procedure that requires the party responsible for compliance ensure that the equipment complies with the appropriate technical standards. The responsible party, who must be located in the United States, is not required to file an equipment authorization application with the Commission or a TCB. Equipment authorized under the SDoC procedure is not listed in a Commission database. However, the responsible party or any other party marketing the equipment must provide a test report and other information demonstrating compliance with the rules upon request by the Commission. The responsible party has the option to use the certification procedure in place of the SDoC procedure. 23-Aug-19 12:10 AM Basically, point an antenna at it and hook it up to a spectrum analyzer 23-Aug-19 12:10 AM Print the screenshots and you're ok 23-Aug-19 12:10 AM Simple enough as long as you don't have anything very high speed on the board 23-Aug-19 12:11 AM Yea basically, just make sure it doesn't puke stuff everywhere and make a paper on it and if we ask you for it, which we never will because you sell less than a million of these things, your fine. 23-Aug-19 12:11 AM yea I wouldn't call an internal oscillator running at 32Khz and being FLLed up to 20Mhz as high speed 23-Aug-19 12:11 AM Oh yeah that's completely missing the point here, no need to worry about that 23-Aug-19 12:11 AM Worrying about trace lengths on silicon is the job of bleeding edge particle physics guys 23-Aug-19 12:12 AM :P 23-Aug-19 12:12 AM This is more of a "PCIe Gen4 across a coat hanger" kind of thing 23-Aug-19 12:13 AM yea lol 23-Aug-19 12:14 AM Are you actually going to be doing PCIe? 23-Aug-19 12:14 AM "Card inside a PC" makes me think of PCIe cards 23-Aug-19 12:14 AM Its 8-bit ISA the friend's card 23-Aug-19 12:14 AM lol 23-Aug-19 12:14 AM so uh 23-Aug-19 12:14 AM yea no 23-Aug-19 12:14 AM far from it 23-Aug-19 12:14 AM That's rather extreme vintage 23-Aug-19 12:15 AM Guess what nearly bleeding edge OLED on a chip production lines run on? :P 23-Aug-19 12:15 AM IBM Industrial PCs... aka 286s 23-Aug-19 12:15 AM Hardware with "DO NOT TOUCH, IT WORKS" stickers on it? 23-Aug-19 12:15 AM :P 23-Aug-19 12:15 AM basically the only thing that changes in those machines is optics 23-Aug-19 12:15 AM I mean... 23-Aug-19 12:15 AM the hardware has been reliable for the last 40 years with minor repairs 23-Aug-19 12:15 AM the replacement hardware is cheap if it needs to be replaced/upgraded 23-Aug-19 12:15 AM it WORKS 23-Aug-19 12:15 AM so whats wrong with it? :P 23-Aug-19 12:16 AM Nothing! 23-Aug-19 12:16 AM But I wouldn't like developing on one 23-Aug-19 12:16 AM But there's modern alternatives for actually new developments 23-Aug-19 12:16 AM Often from the same companies 23-Aug-19 12:18 AM I mean you can at-least look at the schematics of that system, the datasheets, and repair things reasonably. 23-Aug-19 12:18 AM You can, but you don't want to 23-Aug-19 12:18 AM Uhm 23-Aug-19 12:18 AM when having a production line down every minute costs money 23-Aug-19 12:18 AM I mean if you had a choice 23-Aug-19 12:18 AM so first off generally having spares laying around is important, the other thing is my friend can repair those systems for a fraction of the cost of new system to the customer 23-Aug-19 12:18 AM re-cap power supplies/replace boards/etc 23-Aug-19 12:18 AM just a lot cheaper 23-Aug-19 12:18 AM its all common parts that have been around and proven reliable 23-Aug-19 12:18 AM Industry just likes reliable proven technology 23-Aug-19 12:18 AM also not paying to upgrade things when it still "just works" :P 23-Aug-19 12:18 AM so there is stupid reason and reasonable reason behind it 23-Aug-19 12:20 AM Some industry also likes to stay in the past and stay with weird past technology shoves KUKA robot controller 23-Aug-19 12:21 AM lol 23-Aug-19 12:21 AM sometimes past technology is just superior 23-Aug-19 12:21 AM Not this horror 23-Aug-19 12:21 AM you are just barely starting to see silicon replace tubes for SUPER high power transmission stuff 23-Aug-19 12:22 AM Windows XP Embedded running side by side with VxWin, which is a weird custom version of VxWorks 23-Aug-19 12:22 AM its much easier to make a million watt tube that can transmit nicely vs a million watt transistor to do the same lol 23-Aug-19 12:22 AM Talking to an ISA card(2007 device!!!!!) 23-Aug-19 12:22 AM lol 23-Aug-19 12:22 AM yea 23-Aug-19 12:22 AM there is a lot of that crap around in industrial stuff 23-Aug-19 12:22 AM but also realize 23-Aug-19 12:22 AM ISA is super easy to talk to, has REAL hardware interrupt 23-Aug-19 12:22 AM like its why a lot of systems still use it 23-Aug-19 12:22 AM They're using PCIe now 23-Aug-19 12:22 AM seriously, ISA will be around in industrial applications as long as they can push it 23-Aug-19 12:22 AM Well I'm sure at this point with UEFI and shit its going to be de-throned if not already 23-Aug-19 12:22 AM but yea its uh 23-Aug-19 12:22 AM develop something for PCIe and leme know how it comes out 23-Aug-19 12:23 AM No thanks, I'm not masochistic 23-Aug-19 12:23 AM I'm avoiding it until I'm on a team of like 50 people lol 23-Aug-19 12:23 AM :P 23-Aug-19 12:24 AM If I need PCIe, I'm buying a PCIe dev board and beating the hello world demo into something that does what I need 23-Aug-19 12:24 AM And then I put it on the furthest shelf possible 23-Aug-19 12:24 AM yea pmuch 23-Aug-19 12:47 AM moin 23-Aug-19 07:45 AM En regard to the million watt single device transmitter. I have seen million watt tubes. They are pretty straight forward. Generally they are water cooled. As for solid state, I have never seen a single device capable of that sort of power. Based on that I assume the physical implementation of such a transmitter would be easier with a tube based on the fact that they have existed for many years. 23-Aug-19 09:43 AM just imagine the voltages/currents 23-Aug-19 09:43 AM its relatively easy to handle 20kV supply for a tube at odest current, pushing 1MW @ 50 or 100V throug a semiconductor is a whole different storry 23-Aug-19 09:43 AM just imagine the inductive heating in surrounding metal parts... 23-Aug-19 10:23 AM doh, long standing water inside of the electrical cabinet.. 23-Aug-19 10:23 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0543-650BF.jpg 23-Aug-19 10:23 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0544-6C17B.jpg 23-Aug-19 10:23 AM about 1 or 2 cups 23-Aug-19 10:23 AM paper towells worked, but yeah, will be needing to go through that 23-Aug-19 10:23 AM I think I finally got the upper workhead disconnected (minus the oil feed) from everything.. turns out it was on scrapped ways instead of linear roller bearings like the table 23-Aug-19 10:25 AM I bet the transformer and everything else is moist 23-Aug-19 10:25 AM So I'd take the cabinet and do a "bakeout" 23-Aug-19 10:25 AM should be able to lift it off with engine hoise, as that hump in the trunk (back of the unit) allows the lifter stabalizer feet to get near 23-Aug-19 10:25 AM I had to cut one wire to the motor, screw at the junction terminal thing wouldn't budge, the other 7 or however many did though 23-Aug-19 10:25 AM k, daylight is wasting.. 23-Aug-19 10:25 AM the main goal for today is the workhead removal (and store inside).., the main base unit is still half questionable.. may be getting some things today to help 23-Aug-19 10:25 AM .. maybe 23-Aug-19 10:25 AM kthxbye 23-Aug-19 12:58 PM taking a moment to reocuperate.. lunch time 23-Aug-19 02:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/brazed_KF10-A77E1.jpg 23-Aug-19 02:19 PM @Pan Da broken KF10 Brazed with Ag40Cd, then beadblast to remove the flux 23-Aug-19 02:55 PM uh sexyyyyyy 23-Aug-19 02:55 PM i ordered NW25 hose yesterday and have re-machined fittings from a broken KF25 Hose 23-Aug-19 02:55 PM we'll see how that goes once the hose arrives 23-Aug-19 02:55 PM oh, did you buttwel...buttsolder or is that hose shoved over a stickout of pipe on the flange? 23-Aug-19 03:28 PM this one is just two corrigations of the pipe soldered together because there was a crack in the valley between the two 23-Aug-19 03:28 PM im not sure wich kind of connection i would do otherwise, i guess id decide depending on the shape of the flange i had at hand and choose which ever option has the lowest virtual leak geometry 23-Aug-19 04:04 PM ohhhh, ok 23-Aug-19 04:45 PM I think I fiigured out strapping the head drive unit on this puppy.. thing is it basically needs to be extended in order to get out of the base, then it's kinda tall and the hoist is having trouble getting that high 23-Aug-19 04:45 PM lots of 'in hindsight' thoughts 23-Aug-19 04:45 PM going to actually make a dinner though, got consumed with this yesterday that all I fed myself was a sandwich at 11pm 23-Aug-19 10:48 PM drive unit off and barely on my property.. the base unit is now light enough I can tip it 23-Aug-19 10:48 PM but holy hell... sometimes helping hands dont know what they are doing 23-Aug-19 10:48 PM prob messed up a few of the spindles 23-Aug-19 10:48 PM oh, a forklift woulda been awesome 23-Aug-19 10:50 PM But the base is light enough you can just push it? 24-Aug-19 12:54 AM I can tilt it.. and I got 2 skates, polus I have a hydraulic jack that has some wheel resembling things... is the half though 24-Aug-19 12:54 AM also, I am pretty sure I messed my back up... will pay the money to have someone else figure this all out next time 24-Aug-19 12:55 AM Sounds like you got a lot of weight off 24-Aug-19 12:55 AM Oof 24-Aug-19 12:55 AM Yeah you have to watch out for that 24-Aug-19 12:55 AM I have no idea how much damage (till tomorrow) we did to the head unit though 24-Aug-19 12:55 AM it scrapped a bvit 24-Aug-19 12:55 AM some of the spindle oputputs 'touched' the concrete... 24-Aug-19 12:55 AM they all still spin free enough 24-Aug-19 12:55 AM but, how true 24-Aug-19 12:55 AM also, I think I got my appetite back, less stress 24-Aug-19 12:55 AM about to watch the latest BattleBots 24-Aug-19 12:56 AM What's the current plan for getting the base up? 24-Aug-19 12:57 AM there isnt one because the head unit still has to make it inside, it is just at the bottom of my exterior stairs 24-Aug-19 12:57 AM the initial thought is to skate it off the pallet 24-Aug-19 12:57 AM Then? 24-Aug-19 12:58 AM then into the same spot, bottom of stairs.. and then........ 24-Aug-19 12:58 AM figure out if the engine hoist can pull it up 24-Aug-19 12:58 AM I discovered my lifting straps are not long enough for the proposed method 24-Aug-19 12:58 AM I may still need a rigging company to move it up and in 24-Aug-19 12:58 AM I dont htink I will ever try to do that on my own again 24-Aug-19 12:58 AM it is visibly making progress though, which is good because even this evening tons of pepople would park their friggin car and come outto look at it.. those were typically truck drivers too, if that tells you anything 24-Aug-19 12:58 AM I am so glad I cooked that chicken earlier... k... time to watch battlebots and more or less pass out... will examine where things stand tomorrow AM... 24-Aug-19 03:29 AM Remember taking your iodine pills boys 24-Aug-19 04:41 AM New news on the accident with the nuclear powered missile? (Or just general advice) 24-Aug-19 04:57 AM informaion is very smeared, all I know is that friends of mine all over germany didn't measure any significant rise of synthetic nuclei 24-Aug-19 06:09 AM moin 24-Aug-19 06:09 AM yeah what's about that "germany buys over 9 billion iodine pills ..."? y? 24-Aug-19 06:12 AM 9 billion O.o 24-Aug-19 06:12 AM as I heard was 190 Million 24-Aug-19 06:13 AM yeah, was a joke 24-Aug-19 06:13 AM 9B style 24-Aug-19 06:13 AM over 9B style 24-Aug-19 06:13 AM instead of over 9k 24-Aug-19 06:14 AM ahh, ok :D 24-Aug-19 06:16 AM but 190 million is also plenty 24-Aug-19 06:16 AM but afaik that's just a precaution 24-Aug-19 06:16 AM ":|" 24-Aug-19 06:17 AM iodine are a good first measure if some reactor has a misshap, actually I'm surprised they only bought them now 24-Aug-19 06:17 AM every country should have them in storage 24-Aug-19 06:18 AM i have some 24-Aug-19 06:19 AM those aren't regular iodine pills 24-Aug-19 06:19 AM let's just say iodine overdose is easier to treat than the corresponding cancer 24-Aug-19 06:20 AM well they are "regular iodine pills" 24-Aug-19 06:20 AM 65mg or something 24-Aug-19 06:20 AM you can buy them at the apotheke 24-Aug-19 06:20 AM but i would not eat theme without a nuclear mishap ^^ since yeah, they can fck u up quite a bit 24-Aug-19 06:20 AM or not? 24-Aug-19 06:23 AM there are iodine supplement pills and those for nuclear emergencies, for blocking iodine intake 24-Aug-19 06:23 AM but maybe they're special i only know the "normal" free pills 24-Aug-19 06:23 AM yeah 24-Aug-19 06:23 AM according to the internet everyone above 13 should take two of those 65 mg pills a day 24-Aug-19 06:23 AM well, 65mg are the proper ones 24-Aug-19 06:23 AM yes 24-Aug-19 06:23 AM 1-2 in case of emergency 24-Aug-19 06:24 AM they are free - even in germany 24-Aug-19 06:24 AM or more exactly they were free a few years ago ^^ 24-Aug-19 06:24 AM just most people dont have a clue and just buy "some iodine pills" 24-Aug-19 06:24 AM not sure if they still are free, since germany is all about safety 24-Aug-19 06:25 AM "IoDiNe HeLpS aGaInSt NuCleAr RaDiAtIoN" 24-Aug-19 06:26 AM well, since the new 190mil are not going to be distributed without a reason you can be sure you wnt get any for fee 24-Aug-19 06:26 AM you can always jus take 1337 of the supplement ones 24-Aug-19 06:26 AM and i guess its the right move, people would just be to retarded to use them the right way 24-Aug-19 06:26 AM but 24-Aug-19 06:27 AM how ever, i have the 65mg ones 24-Aug-19 06:27 AM some people would just take them regularly and wonder about yellow skin and others would scream chemtrails 24-Aug-19 06:27 AM and i got them at the apotheke 24-Aug-19 06:27 AM may neighbour has some weird antennae in his backyard, better take some iodine against the radiation! 24-Aug-19 06:27 AM but some more years ago even ephedrine was free ^^ 24-Aug-19 06:28 AM I am pretty sure that if you run into a pharmacy and scream I NEED AN EPIPEN they still are free 24-Aug-19 06:28 AM btw i have a few epipens 24-Aug-19 06:28 AM not free versions %) 24-Aug-19 06:28 AM do you need them? 24-Aug-19 06:29 AM since i'm a little paranoid 24-Aug-19 06:29 AM just in case!11 24-Aug-19 06:29 AM what if you need one and then you have NONE 24-Aug-19 06:29 AM just in case you suddenly develop a strong allergy 24-Aug-19 06:29 AM my dad just carries an ampule and a syringe 24-Aug-19 06:29 AM @george wise man 24-Aug-19 06:29 AM at least in times when epipens are on a shortage again... 24-Aug-19 06:29 AM yep 24-Aug-19 06:29 AM some joke about my grandpa always carrying some pills with him during the war 24-Aug-19 06:30 AM xD 24-Aug-19 06:30 AM well, my dad is allergic to bees so.... 24-Aug-19 06:30 AM i mean rly i don't want to rely on the german emergency infrastructure 24-Aug-19 06:30 AM he was a beekeeper a few decades ago and then developed an allergy 24-Aug-19 06:30 AM and found out thehard way 24-Aug-19 06:30 AM @N00N fair point 24-Aug-19 06:31 AM i don't belive they can handle any kind of a bigger "mishap" 24-Aug-19 06:31 AM though honestly speaking of apocalypses, electricity outage is by faar the most likely 24-Aug-19 06:31 AM I know they can't 24-Aug-19 06:31 AM if two semitrucks full of milk crashed ... that max them out 24-Aug-19 06:32 AM if only you knew 24-Aug-19 06:32 AM or disarming of WW2 bombs 24-Aug-19 06:32 AM I got some inside in the nuclear erm... katastrophenschutz during work 24-Aug-19 06:33 AM evacuate everyone in a 3km radius without a real indication and stuff 24-Aug-19 06:33 AM like that 24-Aug-19 06:33 AM if anything would happen 24-Aug-19 06:33 AM no one knew what to do 24-Aug-19 06:33 AM who to call 24-Aug-19 06:33 AM yeah thing is, most "katastrophenschutz" is more a hobbyists domain in germany 24-Aug-19 06:33 AM the main motivation is "gemeinsammes grillen und bier" :> 24-Aug-19 06:34 AM we don't even have sirens in our bigger cities 24-Aug-19 06:34 AM ehehehe 24-Aug-19 06:34 AM THW, Trinken, Helfen, Weitersaufen! 24-Aug-19 06:34 AM yeah, that's funny in my small village we have 5 sirenes 24-Aug-19 06:34 AM all the käffer still have them 24-Aug-19 06:34 AM one of em on my house 24-Aug-19 06:34 AM but no hospitals 24-Aug-19 06:34 AM yeah 24-Aug-19 06:34 AM only vets 24-Aug-19 06:34 AM but vets are okay 24-Aug-19 06:34 AM they are not afraid of fleischwunden 24-Aug-19 06:36 AM id preffer to have surgery by my local vet over my local hospital... 24-Aug-19 06:36 AM i know our dogs never got infected like my mom did in hospital 24-Aug-19 06:37 AM with the smallest thing a normal hausarzt sends you to the krankenhaus 24-Aug-19 06:37 AM eigentlich können wir hier ja gleich wieder deutsch reden oder? xD 24-Aug-19 06:37 AM but the krankenhaus is annoyed about those small thing 24-Aug-19 06:37 AM yeah 24-Aug-19 06:38 AM but i guess the tommys and yanks would get democracy eyes 24-Aug-19 06:38 AM As moderator I'll have to enforce english 24-Aug-19 06:39 AM okay, i've you go the hospital and all you want are a few stitches 24-Aug-19 06:39 AM they'll let you wait for 1-2 days and make everything overcomplicated 24-Aug-19 06:39 AM and yeah, the infection risc with those super-resistant germs is another ugly thing 24-Aug-19 06:41 AM if it was something non life threatening id just have my dad do it 24-Aug-19 06:41 AM like stitches, not surgery 24-Aug-19 06:41 AM he can stitch gums well enough not to leave any scar, i guess normal skins not different from that 24-Aug-19 06:43 AM should I never need stitches reminds me to buy a train ticket to your dad 24-Aug-19 06:43 AM and the hands on surgeons here are northafricans, iranians and arabs - i guess because they have some experience in improvising things 24-Aug-19 06:43 AM yeah, where are the promised full auto robot surgeons 2019? 24-Aug-19 06:45 AM in a magical Land with good Internet 24-Aug-19 06:49 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/frasen_schragloch-56526.jpg 24-Aug-19 06:49 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/alle_scheiben-1D5C6.jpg 24-Aug-19 06:49 AM fun fun 24-Aug-19 06:49 AM now ill finally have to get some stailess tubing 24-Aug-19 06:49 AM none to be found so far 24-Aug-19 06:50 AM cool 24-Aug-19 06:50 AM milling like this is scary af 24-Aug-19 06:50 AM tilting this 200kg (?) table 24-Aug-19 06:52 AM is that a cryo head? 24-Aug-19 06:52 AM and if, what kind of? ^^ 24-Aug-19 06:52 AM i mean the working principle 24-Aug-19 06:52 AM looks like you DIY it from scratch? 24-Aug-19 06:53 AM gm 24-Aug-19 06:53 AM have posted a few more pics over the last few days 24-Aug-19 06:53 AM sadly some stuff is still missin that i most likely wont get my hands on before ill leave home for a month.... 24-Aug-19 06:53 AM but well, it will work somehow 24-Aug-19 06:55 AM nice 24-Aug-19 06:55 AM the plan was to get it woking this weekend or maybe next week but thats doubtful 24-Aug-19 06:56 AM :< 24-Aug-19 06:56 AM we want cryo now! 24-Aug-19 06:56 AM me too 24-Aug-19 06:56 AM maybe you should finish your compressor faster then we have cryo as well 24-Aug-19 06:57 AM but in that case I'd have to to something instead of telling others they should work more 24-Aug-19 06:57 AM who knows where this might lead to, in the end I'd have to make my stuff myself! 24-Aug-19 06:59 AM that would be... 24-Aug-19 06:59 AM devestating 24-Aug-19 06:59 AM I know, right? 24-Aug-19 06:59 AM btw, is there any kind of drossel inbetween the oil cooler and compressor inlet? 24-Aug-19 07:00 AM of cause 24-Aug-19 07:00 AM well 24-Aug-19 07:00 AM on the exit of the compressor oil sump 24-Aug-19 07:00 AM good, because I don't remember one, but I thought there should be one 24-Aug-19 07:00 AM limiting the exiting ammount of oil 24-Aug-19 07:00 AM but somewhere inside of that kreislauf 24-Aug-19 07:01 AM have a look at the schematic in the manual 24-Aug-19 07:01 AM maaayyybe it was a piece of capillary but i dont remember 24-Aug-19 07:01 AM didnt you take pics? 24-Aug-19 07:01 AM not of the compressor :/ 24-Aug-19 07:02 AM well that sucks xD 24-Aug-19 07:02 AM i allways wanted to and forgot to as well 24-Aug-19 07:03 AM right 24-Aug-19 07:07 AM The supplement iodine pills have 2mg of potassium iodide (equiv. 1530 ug potassion ions) 24-Aug-19 07:07 AM (There's 28 in a box) 24-Aug-19 07:11 AM yep 24-Aug-19 07:14 AM So I guess in a pinch you could take a whole box to reduce your risk of developing pancreatic cancer years after. 24-Aug-19 07:14 AM thyroid, but yes 24-Aug-19 07:15 AM all the cancers 24-Aug-19 07:15 AM Ah, should have looked up the translation 24-Aug-19 07:15 AM not 24-Aug-19 07:15 AM The other Drüse 24-Aug-19 08:19 AM @george stainless hose arrived! now just have to wait for your silver solder to be delivered here by you. :-P 24-Aug-19 08:19 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/photo_2019-08-24_17-15-18-21788.jpg 24-Aug-19 08:20 AM personally i assume? 24-Aug-19 08:20 AM we've got goods for exchange 24-Aug-19 08:20 AM (top one is one of my older KF hoses as reference 24-Aug-19 08:20 AM yes of course personally, what fun would it be without you? 24-Aug-19 08:20 AM and the silver solder is also easily transportable by bike. 24-Aug-19 08:21 AM and the Ti tube and whatnot on your way back.... well that's your issue 24-Aug-19 08:22 AM https://webimg.secondhandapp.com/w-i-mgl/536e7a1ad928d1d2308b45f4 24-Aug-19 08:22 AM do whatever you want do with it 24-Aug-19 08:25 AM will just replace the handlebars 24-Aug-19 08:26 AM noooo, do one of those sparks-when-wheelie-thingies! 24-Aug-19 08:26 AM nixie would be proud 24-Aug-19 08:28 AM mhh, just stick it through some place next to the engine so it will stick out both sides like trainingwheels 24-Aug-19 08:28 AM having fun in the corners 24-Aug-19 08:28 AM level advancing on its own 24-Aug-19 08:28 AM just dont get to close to some lamp post 24-Aug-19 08:30 AM DÖNG Hier ist das erste deutsche Fernsehen mit der Tagesschau. 24-Aug-19 12:02 PM moin! 24-Aug-19 01:13 PM Joined the server. 24-Aug-19 01:28 PM So far I've gathered that there's two local communities of nerds 24-Aug-19 01:28 PM One in Germany, one in... around(?) silicon valley 24-Aug-19 01:43 PM and one is called "ostblock" 24-Aug-19 01:50 PM I visited my friend's shop this morning 24-Aug-19 01:50 PM he's got a ton of fun equipment 24-Aug-19 01:50 PM a WEDM system, a huuuge grinder(for tools?), a gear hobber(/gear mill thing) 24-Aug-19 01:50 PM I'm really tempted to make one of those smooth fit joints that are made into gifs 24-Aug-19 01:50 PM WEDM the pieces, then grind the surface... 24-Aug-19 01:59 PM More like USA folks and Europeans. 24-Aug-19 01:59 PM Do we have members on other continents? 24-Aug-19 02:00 PM we have russians. but i don't know from which side of the ural... 24-Aug-19 02:01 PM I'm pretty sure that it's technically still the same continent :P 24-Aug-19 02:01 PM east of it is called asia... 24-Aug-19 02:01 PM at least that's what i have been told in school 24-Aug-19 02:02 PM That's not a continent 24-Aug-19 02:02 PM "European Russia" or just everything west of Urals. 24-Aug-19 05:49 PM Just so you know @Conmega this is about how much wood I like to have to move heavy things in odd situations 24-Aug-19 05:49 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190824_163134-7D2E7.jpg 24-Aug-19 05:53 PM jeez ok 24-Aug-19 06:17 PM for those not in the know... a forklift is being dropped off tomorrow for 24hrs.. which is how it should have been done from the start 24-Aug-19 07:18 PM just moved the surface plate and lab chemicals out of the way for a clearer path 24-Aug-19 07:18 PM also, I am imagining the custom connectors and whatnot y'all will be requesting once all setup.. 24-Aug-19 07:18 PM sneak peak at existing scrapped V way on the base 24-Aug-19 07:18 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0551-DB4A2.jpg 24-Aug-19 07:18 PM plenty of meat left on there 24-Aug-19 08:45 PM @AdamMcCombs I actually enjoy building packing crates. It’s a very satisfying feeling of quickly going from need to final product. 25-Aug-19 12:25 PM oh boy... 25-Aug-19 12:25 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_0554-23F9E.jpg 25-Aug-19 02:02 PM Holy hell 25-Aug-19 02:02 PM If anyone with a sem here has access to an Epson piezoelectric printhead (inkjet, most epsons are), PUT IT IN THE SEM 25-Aug-19 02:02 PM I just pulled apart one that suffered a leak and wow... 25-Aug-19 02:02 PM Hundreds of absolutely tiny piezoelectric crystals tombstoned on a flat flex, inserted into what looks like a sinker EDM'ed piece, folded over, and inserted on the second row. 25-Aug-19 02:02 PM This is an engineering marvel 25-Aug-19 02:07 PM oh wow 25-Aug-19 02:07 PM care to share any pics? ^^ 25-Aug-19 02:08 PM I will if I can get my macro setup working fine enough to even see this 25-Aug-19 02:15 PM yeah, those printheads are sick... 25-Aug-19 02:15 PM allways wondered if there was some easy mischief to do with them 25-Aug-19 02:16 PM there is 25-Aug-19 02:16 PM printers all over the world do it every day 25-Aug-19 02:17 PM thats to devious 25-Aug-19 02:17 PM https://www.youtube.com/watch?v=IU6uwvM5euo 25-Aug-19 02:17 PM i wand one of these 25-Aug-19 02:17 PM though i know there is more beefy ones for industrial applications and outdoors 25-Aug-19 02:17 PM like marking concrete sewage pipes 25-Aug-19 02:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/printer-0E836.gif 25-Aug-19 02:19 PM buy a xaar 128 head and a ps2 mouse :P 25-Aug-19 02:19 PM exactly 25-Aug-19 02:19 PM ooooooooohhhhhhhh 25-Aug-19 02:19 PM sweet 25-Aug-19 02:19 PM i dindt know they existed so tinkering friendly 25-Aug-19 02:20 PM they're not supposed to be 25-Aug-19 02:20 PM but the datasheet got cough 25-Aug-19 02:20 PM and someone cough 25-Aug-19 02:20 PM and now it's public 25-Aug-19 02:20 PM oh 25-Aug-19 02:20 PM whoops 25-Aug-19 02:22 PM https://i.kym-cdn.com/entries/icons/original/000/028/186/spidey.jpg 25-Aug-19 02:41 PM 270eur is not "gona buy this for playing around" cheap, but much cheaper than a full printer. 25-Aug-19 02:42 PM The xaar? 25-Aug-19 02:42 PM Yeah they're industrial heads 25-Aug-19 02:42 PM I do people playing around with epson inkjet cartridges ten years ago or something like that. 25-Aug-19 02:42 PM I recall seeing stuff on hackaday. 25-Aug-19 02:42 PM There's inkjet hacks 25-Aug-19 02:42 PM ANd yeah the xaar. 25-Aug-19 02:42 PM Did also take a look at direct to gearment printing years back out of general interest. 25-Aug-19 02:43 PM But driving consumer inkjet heads is like sequencing the appollo launch, but with 10 voltage rails and levels 25-Aug-19 02:43 PM You can find new xaar heads for around $100-150 25-Aug-19 02:44 PM Sweet 25-Aug-19 02:44 PM With that said, you can pretty much only find new heads lol 25-Aug-19 02:44 PM There's almost no used market for them 25-Aug-19 02:56 PM I've played around with the xaar 128 a bit 25-Aug-19 02:57 PM I swear, I mention anything and someone from this chat has already done it 25-Aug-19 02:58 PM Made a controller for it, formulated my own ink, and jetted it 25-Aug-19 02:58 PM That's why it's awesome to be surrounded by like minded geeks who are just as insane as you are. 25-Aug-19 02:58 PM Or in case of this board, even worse. 25-Aug-19 02:58 PM In all the best ways. 25-Aug-19 03:00 PM No voice chat today? 25-Aug-19 03:02 PM just join if you want to, I can send out a notification 25-Aug-19 06:27 PM Gah, I caved. Ordered $170 worth of stainless vacuum fittings from the land of the east. 25-Aug-19 06:27 PM Still going to machine a few, since they're either very expensive or I have spare alu stock to make them 25-Aug-19 06:27 PM And the KF50 gate valve should arrive any day now 25-Aug-19 06:34 PM please don't mention KF50 in my vicinity. always gives me a nervous breakdown. i have fittings, valves, clamps, a viewglass, everything in KF50... everything except the o-rings. and i'm not yet ready to pay vast amounts of money on those suckers... 25-Aug-19 06:34 PM Ha! There's a trick! 25-Aug-19 06:34 PM Buy them separately. 25-Aug-19 06:34 PM The o-rings and centering rings. 25-Aug-19 06:34 PM Got mine for half price that way 25-Aug-19 06:34 PM but i haven't found a good source on them yet 25-Aug-19 06:35 PM eBay 25-Aug-19 06:35 PM sort by -> Price + Shipping - Lowest First 25-Aug-19 06:36 PM yes. been there, done that, but this is germoney... 25-Aug-19 06:36 PM I'm only a country away 25-Aug-19 06:36 PM in which direction? the cheap or the expensive one? 25-Aug-19 06:36 PM the dictator one 25-Aug-19 06:39 PM oh, the chinese have 10pcs for 40 bucks... 25-Aug-19 06:39 PM or 3 for 3,50 each 25-Aug-19 06:40 PM mhm 25-Aug-19 06:40 PM make sure you buy viton 25-Aug-19 06:40 PM the rubber is questionable 25-Aug-19 06:41 PM yes, of course 25-Aug-19 06:41 PM uhhhh, KF50 with mesh. nice 25-Aug-19 06:42 PM here's a handy chart 25-Aug-19 06:42 PM https://i.spirit.re/HvCs3.png 25-Aug-19 06:42 PM 5x55 is KF50 25-Aug-19 06:43 PM and some with "FKM viton O-Ring" :-D 25-Aug-19 06:44 PM yep 25-Aug-19 06:44 PM and thanks for the chart 25-Aug-19 06:44 PM thank the site I stole it from 25-Aug-19 06:44 PM https://www.ebay.com/itm/KF50-Stainless-steel-vacuum-Centering-Ring-with-O-ring-FKM-viton-10pcs-pack/222620467087 25-Aug-19 06:44 PM $4.5 each 25-Aug-19 06:46 PM 4€ each ^^ 25-Aug-19 06:46 PM at least in the german version of ebay 25-Aug-19 06:46 PM always use ebay.com unless you're hunting for local deals 25-Aug-19 06:47 PM less censorship, less translation errors, but is there another reason? 25-Aug-19 06:47 PM local versions often skip a bunch of listings 25-Aug-19 06:47 PM it's also handy to use .com and switch to US shipping 25-Aug-19 06:47 PM because there's tons of sellers(including outside the US!) who will ship worldwide but mess up with setting up shipping options 25-Aug-19 08:20 PM Surgery with a forklift 25-Aug-19 08:20 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190825_195214-E8FAE.jpg 25-Aug-19 08:22 PM this grinder is awfully similar to the one my friend has 25-Aug-19 08:22 PM except my friend's is soviet 26-Aug-19 12:22 AM https://www.ir-dichtungstechnik.de/gewerbe/en/o-ring-50-0-x-2-5-mm-fkm-75-5-shore-a-braun-brown.html 26-Aug-19 12:22 AM (o-rings only) 26-Aug-19 06:14 AM Hey TW 290/20/20 user ! , I have a question : how to connect a TW 290/20/20 Turbo pump to my scroll pump? There is only a small output with a sort of Black plastic ring at the bottom of the TMP pump; Do I need to use a "OERLIKON LEYBOLD VACUUM 16840, Screw-in flange DN16 KF" to connect it to my scroll pump with 16KF input flange? 26-Aug-19 06:14 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/TMP_TW290_20_20-BEF6F.jpg 26-Aug-19 07:05 AM A question about the Turbo drive TD 400 (leybold Pump controller) : Do you know if somewhere i can found an open source alternative for LEYASSIST leybold software (that drive the TD 400 driver) ? Or do I need to code one myself to send all commands by hand via the RS485 connecter and? ... any other suggestion is welcomed .... 26-Aug-19 07:15 AM I mean unless you really need super complex control you could always just get a USB to RS485 adapter and just send the command to spin up/spin down the turbo. 26-Aug-19 07:15 AM Just to get it going and test it. Automated control you'll obviously need to make some software, I don't know of any good open source general turbo control software available just because of the sheer number of options and special applications these things go into... 26-Aug-19 07:15 AM Its generally custom made for every product its placed in. 26-Aug-19 07:25 AM naaahhhh 26-Aug-19 07:25 AM they can be started by a simple switch on the io port 26-Aug-19 07:25 AM vacuum connection is done by a "clamp" made from sheetmetal directly pressing a KF16 into the hole 26-Aug-19 07:25 AM the hole should accept a standard KF16 seal ring 26-Aug-19 07:25 AM the plastic part should just be a dummy / plug 26-Aug-19 07:25 AM i did all via the rs232, i dont remember the name of the software but you can download it for free directly from leybold 26-Aug-19 07:25 AM also lets you trigger the run in mode wich is recommended after 6months+ of resting time 26-Aug-19 07:28 AM to @george , ah ok, I will check this "dummy" plug... thanks to @Conmega also. 26-Aug-19 07:29 AM i cant really tell from the picture, maybe its just a blackened kf16 ring 26-Aug-19 07:29 AM however you will have the pleasure of filing a piece of sheetmetal to fit this setup 26-Aug-19 07:29 AM To @george : Do you know how to vent the pump circuit when I turn off the pump. is there any specific procedure when I turn on the TMP? 26-Aug-19 07:29 AM https://www.picclickimg.com/d/l400/pict/392234449053_/OERLIKON-LEYBOLD-800160V0021-TURBOVAC-TW290-20-20-UHV-mit-TURBODRIVE.jpg 26-Aug-19 07:29 AM thats how it looks with a blind flange fitted 26-Aug-19 07:29 AM well, first turn it off 26-Aug-19 07:29 AM then have it spool down, preferrably completely but that can take up to an hour due to the very massive rotor in this one 26-Aug-19 07:29 AM the manual states you are allowed to vent it at full speed BUT NOT SUDDENLY 26-Aug-19 07:31 AM I couldn't find the manual on line... Have you one to send to me Please? 26-Aug-19 07:31 AM you can do so very very very craefully and slowly but it will load the bearings more 26-Aug-19 07:31 AM one sec 26-Aug-19 07:31 AM can you read german? 26-Aug-19 07:32 AM Yes, it why I want to use a software to control de TMP... To control the speed of the fan inside the TMP during the turn-off procedure 26-Aug-19 07:33 AM i have the full manual sent to me by leybold but its not the english version 26-Aug-19 07:33 AM you will not be able to do that thoug, i t accepts reduced speed commands but only down to 80% speed iirc 26-Aug-19 07:33 AM No , But Google translate will do the job for me if you have a pdf file in German. Ich konne ein btichen deutch sprechen (i'm a right?) 26-Aug-19 07:33 AM bearings actually dont like slower speeds 26-Aug-19 07:33 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/GA_TW290_20_20-8BA9E.pdf 26-Aug-19 07:33 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/TD_400_GA_17200492_001_C0-17F1C.pdf 26-Aug-19 07:33 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Schnittstellen_GA05281_001_C01-614DD.pdf 26-Aug-19 07:33 AM if you want to do software control the last one will be the most useful to you 26-Aug-19 07:33 AM i have programmed some stuff in arduino to control mine and display the most needed parameters on oled displays but its a few years back now and i cant promise anything about code quality 26-Aug-19 07:38 AM Thanks 26-Aug-19 07:38 AM maybe just ask leybold for documents, they are usually very helpful even to individuals 26-Aug-19 07:38 AM at least regarding support by documents 26-Aug-19 07:39 AM ok I 'll do contact Leybold 26-Aug-19 07:39 AM another useful feature of doing software control is to be able to read the run time counter to judge how many years it has already done 26-Aug-19 07:42 AM Good point you'd spot there @george 26-Aug-19 07:42 AM Here is your doc automatically translate into englush by Google Translate.. 26-Aug-19 07:42 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/GA_TW290_20_20.de.en-326DE.pdf 26-Aug-19 07:42 AM No so bad translation in 2 mn 26-Aug-19 08:48 AM @yann35 just remember that you have to plug up the cartridge separation if you want to use it as a regular turbo 26-Aug-19 08:48 AM only the top opening is high vacuum 26-Aug-19 09:38 AM did anyone else actually use one of these and go through the trouble of plugging it all? 26-Aug-19 09:54 AM A friend ordered a 400/ model 26-Aug-19 09:54 AM If it's not too expensive to ship, I'll get it 26-Aug-19 09:54 AM I'm going to need one hell of a lathe to make the housing 26-Aug-19 11:59 AM Is it possible to mount a CF vacuum flange on the TW 290/20/20 Turbo pump? (My objective is 10^-11 torr...) 26-Aug-19 12:18 PM To properly clean the spare parts I order on Ebay for my UVH device, here is a procedure I watched on Sam Zeloof's video (https://www.youtube.com/watch?v=iZ9ieSHOZsg&t=1s). He indicates : " Note: for all manupulations used nitrile gloves 1st step - wipe the parts (CF, Tube, Valve, chamber interior, ...) with acetone (to remove fingerprints and organic matter) 2nd step - then use a wipe impregnated with isopropyl alcohol to remove the Aceton residues ... " These 2 only steps seem to you sufisantes? For the record, I will also then back the Chamber because I have to get a very low vacuum level (10 ^ -11 ... 10 ^ -12) 26-Aug-19 02:53 PM you're not going to reach -11 with the 290 26-Aug-19 02:53 PM I believe it's only rated to -7 26-Aug-19 02:53 PM you will need all CF flanges on every device to get to -11 26-Aug-19 02:53 PM as well as very heavy bakeout 26-Aug-19 02:53 PM but more importantly, why do you need -11? 26-Aug-19 02:53 PM it's quite an extreme vacuum and there aren't many applications for it 26-Aug-19 03:06 PM Off course , I will add an ion pump to achieve that goal ... it’s for a quantum computer (ion trap based ) 26-Aug-19 03:06 PM you can't make a quantum computer in just a vacuum 26-Aug-19 03:06 PM you'll need to chill below ~4K to observe any meaningful quantum effects 26-Aug-19 03:07 PM No... but I need one . It’s one part of the all setup 26-Aug-19 03:07 PM No need to go to -4K with ion trap. As the ion are laser cooled ... no need of any fridge ... it run at room temperature :-p 26-Aug-19 03:12 PM Unless you have the ability to make precision devices(probably chip fab), I doubt you'll get anywhere at home 26-Aug-19 03:12 PM But, no, this pump won't get you anywhere near what you need 26-Aug-19 03:12 PM you can attach any flange you want to it 26-Aug-19 03:12 PM but there aren't any existing housings, it's a cartridge pump meant to go into a mass spectrometer 26-Aug-19 03:12 PM so you'll need to machine your own 26-Aug-19 03:16 PM Ah... will see... may I ask you what type of pump you would recommande to me ? 26-Aug-19 03:16 PM a normal turbopump 26-Aug-19 03:16 PM rated at -10 26-Aug-19 03:16 PM so enough to reach around -9 26-Aug-19 03:17 PM Ok 26-Aug-19 03:17 PM good luck getting to -11 on a budget though 26-Aug-19 03:21 PM I think there are a couple others here who have done it at home. It takes effort but I wouldn't say it's not possible on a budget. As long as you have a turbo and a ion pump in reasonable condition with all metal seals you don't really need that much. Just be prepared for very long bakeouts, which is easy to run continuously with ion pumps 26-Aug-19 03:21 PM The bigger the chamber though, the longer it will take 26-Aug-19 03:21 PM it's certainly not impossible 26-Aug-19 03:21 PM but -11 is quite extreme 26-Aug-19 03:22 PM Yeah its at the extreme end for sure. You still gotta be pretty dedicated to get there 26-Aug-19 07:28 PM Measuring -11 accurately is very difficult without a properly calibrated gauge setup. Cold cathode tykes May not even start properly and BA type gauges begin having X ray limitations. Lots of literature on it. Big bucks unless you get very lucky finding good second hand gear. 26-Aug-19 07:32 PM Ion pump controllers are often used to measure vacuum if using an ion pump. Current can be related to vacuum level pretty easily 26-Aug-19 07:36 PM the trick to using cold or hot cathode is to start them early 26-Aug-19 07:36 PM though you still have to find one that will actually read at -11 26-Aug-19 07:36 PM most top out at -9 or maaaaaaaybe -10 26-Aug-19 07:36 PM (inaccurately) 26-Aug-19 07:38 PM If you are using an ion pump and you have the specs there is usually a provided curve or formula relating current to vacuum. That's how we do it at our linac facility. No extra gauges, just direct readings from the ion pump controllers. Easiest way really since you need an ion pump usually to get to those levels anyway. 26-Aug-19 07:39 PM Ion pumps are super cheap 26-Aug-19 07:39 PM Ion pump controllers are not 26-Aug-19 07:40 PM Eh, you could build one if needed. The old school ones are pretty simple, though stupid heavy. 26-Aug-19 07:40 PM I want to stick one of those micro pumps into a spare KF16 port 26-Aug-19 07:41 PM Yeah lol, some of them get stupid small 26-Aug-19 07:41 PM it'd be completely useless for me 26-Aug-19 07:41 PM since I doubt I'll reach below -6 without putting actually serious effort into going low 26-Aug-19 07:41 PM and I only need around -5 for my experiments 26-Aug-19 07:41 PM Same for me 26-Aug-19 07:41 PM (and my entire setup is all viton KF and ISO) 26-Aug-19 07:41 PM the only CF fitting I have is... on a pirani gauge 26-Aug-19 07:41 PM the only thing that can top that is if it's on a thermocouple 26-Aug-19 07:42 PM Even with my conflat ports half use viton gaskets since I'm constantly removing them for changes 26-Aug-19 07:43 PM some day I will build a system out of conflats 26-Aug-19 07:43 PM peppered with bolts 26-Aug-19 07:44 PM Bolts and hardware add a surprising amount to cost lol, even if just getting basic SS hardware, none of the fancy stuff 26-Aug-19 07:44 PM this is why it'll be an indeterminate some day 26-Aug-19 07:44 PM and not a soon 26-Aug-19 07:44 PM :P 26-Aug-19 08:22 PM @Noxz , did you get your grinder moved successfully? Sorry I wasn't available yesterday to help... 26-Aug-19 08:22 PM Yes! 26-Aug-19 08:22 PM and we have a GoPro timelapse of most of the move 26-Aug-19 08:22 PM so people can learn how the master does it 26-Aug-19 08:24 PM Sweet 26-Aug-19 08:24 PM unfourtenately my shirt was tucked into my underware in the back.. and no one told me.. the entire night 26-Aug-19 08:27 PM Haha, awesome 26-Aug-19 08:27 PM Orange ones 26-Aug-19 08:27 PM Nerd fashion statement 26-Aug-19 08:27 PM sure 26-Aug-19 08:27 PM but now it is up to me to fix the electrical.. but overall, it seems in decent shape.. everything (mostly) moves smoothly 26-Aug-19 08:27 PM half thinking about how to design the new fence for the front patio (which has been mostly removed) to allow for easy removal of the machiens in one year when I move back to the midwest 27-Aug-19 12:38 AM How many big machines will you be moving in a year? 27-Aug-19 09:11 AM this machine (2500lbs), lathe (+milling attachment) (800lbs), surface plate (500lbs), a few smaller amchines around the 250lbs mark... 27-Aug-19 09:18 AM and a dozen glass vivariums/aquariums 27-Aug-19 09:18 AM kit car chassis, electric car parts, diesel engine.. 27-Aug-19 10:03 AM The heaviest machine I own is only 150lbs 27-Aug-19 10:08 AM does it do the job? 27-Aug-19 10:08 AM also, I have two large machiens and some smaller ones waiting fo rme int he midwest.. 2000lbs jig borer, 1200lbs 3d pantograph, and some 250lbs stuffs 27-Aug-19 12:07 PM k.. lattice frame (to make the patio even and rollable) completely torn down and all the large pieces had the nails completely removed.. time for lunch! 27-Aug-19 12:07 PM next up will be replanting the rose 27-Aug-19 08:25 PM Any suggestions for IC decapping techniques? 27-Aug-19 08:25 PM I wanted to try soaking the epoxy in methylene chloride to soften in and then ultrasonication, but after a few hours in the methylene chloride, nothing seems to be happening (no swelling) 27-Aug-19 08:44 PM fuming nitric acid at ~90C 27-Aug-19 08:44 PM bring up slowly, add TINY amounts 27-Aug-19 08:44 PM fume hood required. 27-Aug-19 10:35 PM No fuming nitric acid or fume hood in my home lab. Might try CO2 laser ablation... 27-Aug-19 10:59 PM regular will work too 27-Aug-19 10:59 PM just slowly and you need to get it hotter 27-Aug-19 10:59 PM but it won't really do much unless it's actually hot 27-Aug-19 10:59 PM nitric in one container, IPA in a spray bottle in the other 27-Aug-19 10:59 PM alternate 27-Aug-19 11:53 PM concentrated sulfuric works too but you will have to heat it more and its a mess 27-Aug-19 11:53 PM but easier to obtain in most countries 27-Aug-19 11:53 PM there's one other dirty trick 27-Aug-19 11:53 PM if you don't care about the package, the leadframe, and just want the chip - boil it in rosin 27-Aug-19 11:53 PM just straight up rosin 28-Aug-19 12:04 AM same case with sulphuric, it eats everything except for gold and silicon 28-Aug-19 01:25 AM yeah nitric acid works fine 28-Aug-19 01:25 AM rosin works too 28-Aug-19 01:25 AM since it's mostly abietic acid ^^ 28-Aug-19 01:25 AM but do it outside if you don't have a fume hood 28-Aug-19 01:25 AM same for nitric acid :> 28-Aug-19 01:55 AM To be clear nitric acid is a bit more than a use it outside sort of thing 28-Aug-19 01:55 AM More of a outside with a fan with a proper mask/nitric acid resistant gloves that won't catch on fire. 28-Aug-19 02:00 AM yeah 28-Aug-19 02:00 AM of course 28-Aug-19 02:00 AM for rosin you should use also a mask :> 28-Aug-19 02:08 AM that is a proper glove 28-Aug-19 02:08 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-21CCC.jpg 28-Aug-19 02:08 AM and that's the kind of mask you need all the time 28-Aug-19 02:08 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-CE0FB.jpg 28-Aug-19 02:18 AM "Protects against organic, anorganic and acidic gases, ammonia and derivatives" 28-Aug-19 02:18 AM that's a wild claim 28-Aug-19 02:23 AM normal 28-Aug-19 02:23 AM it simply says, that it fullfills the ABEK standard in a way ^^ 28-Aug-19 02:23 AM and it simply works for my purpose 28-Aug-19 02:23 AM i smell nothing with the mask on 28-Aug-19 02:23 AM and of course if you surely know that you only have to handle inorganic vapours you should use a B cartridge since it is better in absorbing those 28-Aug-19 02:23 AM but in a normal amateur style lab environment you simply have a wild mix of all teh stuffs so ABEK cartridges are the way to go, right? 28-Aug-19 02:23 AM I mean by/side products you'vent thought about etc ^^ 28-Aug-19 02:23 AM "whats that nasty sme..." game over 28-Aug-19 02:37 AM good thing I haven't done any real chemistry yet 28-Aug-19 03:55 AM mh well but the quantities you need for decapping are so small i wouldnt actually worry 28-Aug-19 03:55 AM keep water neraby to klean yourself off, wear eyeprotection and gloves 28-Aug-19 03:55 AM if you dont have large ammounts arround the catching on fire thing will not happen so fast 28-Aug-19 08:45 AM I threw a xeon CPU into rosin and it didn't do as much as i hoped 28-Aug-19 08:45 AM The solder holding the heat spreader detached, but the interposer/carrier pcb didn't detach or disintegrate 28-Aug-19 08:45 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190628_230912-61D13.jpg 28-Aug-19 08:47 AM Maybe I'll just try my CO2 laser first before getting into the nasty chemicals... 28-Aug-19 08:47 AM It smelled wonderful 28-Aug-19 08:47 AM Like Christmas 28-Aug-19 08:47 AM Lol 28-Aug-19 08:47 AM I also have a co2 laser, and a 1W 405nm 28-Aug-19 08:47 AM Haven't tried decapping with either yet 28-Aug-19 08:50 AM I have a q-switched nd:yvo4 laser that can probably just go through everything: the epoxy, bond wires, silicon, and leadframe... 28-Aug-19 08:51 AM Nice what wavelength? 28-Aug-19 08:52 AM 1064nm. There are harmonic generators for it to convert to 512nm, 355nm, or 266nm, but I haven't been able to find them for cheap. 28-Aug-19 11:56 AM I really want a high power, high frequency q-switched laser 28-Aug-19 11:56 AM To make PCBs through ablation 28-Aug-19 11:56 AM But they're $1k+ on eBay 28-Aug-19 08:15 PM @Deleted User , I've done it with mine. That's why I bought it. 28-Aug-19 08:15 PM heh 28-Aug-19 08:15 PM It was like $6k though 28-Aug-19 08:16 PM oh you and your money 28-Aug-19 08:16 PM :P 28-Aug-19 08:16 PM you can find a working one on eBay for ~$1k 28-Aug-19 08:16 PM just have to look for the 50 or 100W units 28-Aug-19 08:16 PM tons of 10W ones out there 28-Aug-19 08:16 PM Chinese fiber laser can probably do it 28-Aug-19 08:17 PM their 10-20W units start at ~$1.5-2k 28-Aug-19 08:17 PM so no go 28-Aug-19 08:17 PM to ablate copper you need rather high pulse powers and frequencies 28-Aug-19 08:17 PM mainly fluence and pulse length are the most important 28-Aug-19 08:18 PM it's a shame so many of them come with the head, but the fiber is cut 28-Aug-19 08:18 PM the scrappers/sellers don't understand that the fiber is the resonant cavity :( 28-Aug-19 08:18 PM frequency doesn't matter much, because the time between pulses is pretty large compared to the actual pulse length and the time scale of the ablation mechanics 28-Aug-19 08:19 PM higher frequency q-switched ones are usually higher pulse power 28-Aug-19 08:19 PM at least on ebay 28-Aug-19 08:19 PM Yeah lots of fiber lasers on eBay with cut fiber 28-Aug-19 08:19 PM which means it's pretty much dead 28-Aug-19 08:19 PM I guess you can pull the AOM out 28-Aug-19 08:19 PM and pump lasers 28-Aug-19 08:20 PM You want single mode laser for best results. You can get a cheap high pulse power YAG laser (flash lamp pumped) for stuff like tattoo removal. Butt loads of energy per pulse, but very poor beam quality 28-Aug-19 08:21 PM and the life will last about a couple fingernails of PCB area 28-Aug-19 08:21 PM lol 28-Aug-19 08:23 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_1763-72977.JPG 28-Aug-19 08:23 PM One of my earlier practice pieces 28-Aug-19 08:23 PM Ablating the copper while leaving the FR4 undamaged is the trickiest part 28-Aug-19 08:26 PM basically ProtoLaser U3 quality right there 28-Aug-19 08:26 PM :P 29-Aug-19 10:49 AM Going on my honeymoon in Europe starting tomorrow. Anyone from Italy/Switzerland/Germany want to meet up? 29-Aug-19 10:50 AM german here 29-Aug-19 10:50 AM we could do a small meetup 29-Aug-19 10:51 AM I'll be in Munich and Berlin. 29-Aug-19 10:52 AM I'm in munich 29-Aug-19 10:52 AM when? 29-Aug-19 10:53 AM i heard munich meetup? count me in! 29-Aug-19 10:54 AM We'll be in Munich Sept 10, 11, 12 29-Aug-19 10:55 AM we should be mostly free on those days 29-Aug-19 10:55 AM at least I am 29-Aug-19 10:56 AM Cool, maybe we can meet up for dinner or something? 29-Aug-19 10:57 AM sure! 29-Aug-19 10:57 AM preferably on the 11., but I don't know about @Pan Da 29-Aug-19 10:57 AM when will you go to switzerland? 29-Aug-19 10:57 AM Sept 6-9 29-Aug-19 10:58 AM naww 29-Aug-19 10:58 AM if you went there after your trip to munich we could have gone to the cern open days together 29-Aug-19 10:58 AM !!! 29-Aug-19 10:58 AM Wife wouldn't be happy if I tried to change the schedule. 29-Aug-19 11:00 AM heh 29-Aug-19 11:00 AM we could go to the deutsches museum 29-Aug-19 11:00 AM only a shadow of its former self, but still great 29-Aug-19 11:03 AM That's on my list of things to do. It looks awesome! 29-Aug-19 11:04 AM no thanks, no deutsches museum for me 29-Aug-19 11:07 AM @Pan Da , how about dinner? 29-Aug-19 11:08 AM we could meet in the klenze 29-Aug-19 11:08 AM 10 minutes by foot from the deutsches museum and not flooded by tourists 29-Aug-19 11:10 AM yeah thanks dyno. i know it's not nice to say that, but sadly true 29-Aug-19 11:10 AM any alternatives? 29-Aug-19 11:10 AM @piGuy 10.-12. is perfect, nothing important on my list yet 29-Aug-19 11:11 AM ...lol 29-Aug-19 11:11 AM dyno censors the german word for fat 29-Aug-19 11:11 AM I mean I should have seen that coming 29-Aug-19 11:11 AM but 29-Aug-19 11:17 AM big meeting i germany?? 29-Aug-19 11:18 AM the biggest 29-Aug-19 11:18 AM @piGuy where will you stay? 29-Aug-19 11:18 AM of at least 3 (three!) 29-Aug-19 11:39 AM We're staying in a hotel on Dachauer Straße 29-Aug-19 11:40 AM nice, not too far from us both 29-Aug-19 11:40 AM almost in the middle 29-Aug-19 11:40 AM do you like icecream? :-D 29-Aug-19 11:41 AM crazy icecream 29-Aug-19 11:41 AM YES 29-Aug-19 11:41 AM mad icecream rather 29-Aug-19 11:41 AM perfect 29-Aug-19 11:41 AM we'll need to show you the "verrückter Eismacher". 29-Aug-19 11:43 AM We had liquid nitrogen ice cream at our wedding. 29-Aug-19 01:18 PM cute.. is your wife a science nerd also? 29-Aug-19 01:38 PM Nope, she's a finance nerd 29-Aug-19 01:39 PM oof 29-Aug-19 01:39 PM best of luck 29-Aug-19 01:48 PM Haha 31-Aug-19 06:44 AM well sh++... 31-Aug-19 06:51 AM will leave germany on ttuesday next week... 31-Aug-19 06:51 AM we have to do some planned interational meetup some day 31-Aug-19 08:11 AM Hello, I'm looking for the exact denomination to buy a cable. It will be connected between my 4UVH Agilent Ion Pump and the Ion pump itself. This ion pump would be Agilent Varian 9191340 VACION PLUS 55 StarCell Pump (or closed to this model) . On my ion pump controller there is , see the 2nd photo, the , so called, Interlock cable connector. But i would like to be sure of the correct designation of the cable I need to buy (ebay or lesker?). Is this called an "Interlock cable" or there is a special designation ? I ask the question as most of cables I found on ebay contain 7 pins??? I don't think is suitable for my Ion pump controller (cf the photo) 31-Aug-19 08:11 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG-3344-C82C0.JPG 31-Aug-19 08:11 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG-3342-8125A.JPG 31-Aug-19 08:11 AM Below, here is most form factor of the cable I saw on ebay (7 pins ???!!!)... any help would be appreciate to find the correct designation before buy one unit . 31-Aug-19 08:11 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/s-l1600-23A83.png 31-Aug-19 09:30 AM Both are LEMO 31-Aug-19 09:30 AM Probably 1B or 0B series 31-Aug-19 09:30 AM Get familiar with their designations, you'll find them on a lot of high end equipment :P 31-Aug-19 02:37 PM Thanks for this info @Deleted User 31-Aug-19 07:27 PM "You're a student and working in a university on a project and require a connector (1 or 2 units). Log into LEMO's intranet to make a sample request. Every effort will be made to send the requested samples; however, samples are subject to availability." 31-Aug-19 07:42 PM I have a dilemma 31-Aug-19 07:42 PM This VAT valve that I have operates in a funny way - the vacuum valve bit itself operates without friction on the seals. When you give the air cylinder(32mm diameter,4.5 to 7 bar) pressure, it first pushes the actual gate all the way in, then it slips, and the two bits of the gate are pushed against the flanges. 31-Aug-19 07:42 PM Now, I don't have an air supply for my proposed vacuum station, and I'd like to avoid having to purchase and rig up a valve/solenoid system, as well as a dedicated mini compressor. 31-Aug-19 07:42 PM What's the best way to apply 40-50kgf to this piston rod without air? 31-Aug-19 07:42 PM A car air compressor could work, but that's going back to air... 01-Sep-19 05:00 AM moin! 01-Sep-19 05:22 AM @yann35 ehm, you need a https://www.idealvac.com/s-Ion-Pumps/pp/P105796 right? 01-Sep-19 05:22 AM moin 01-Sep-19 05:23 AM yes. Thanks for the reference 01-Sep-19 05:33 AM np 01-Sep-19 05:35 AM outch... 1130 $ for a 20m cable !? ... I hope there is some gold inside at this price ... it's crazy no? 01-Sep-19 05:43 AM normal vacuum stuff prices for new sht 01-Sep-19 05:43 AM but modern HV connectors itself are not cheap 01-Sep-19 05:44 AM Regarding Ion pump on Ebay, I think there is a risk to buy a very used pump...but, according to your experience, what is the impact of using a very old ion pump? does it work less well (more difficult to reach the desired vacuum level) or is there a risk of damaging the vacuum chamber? 01-Sep-19 05:44 AM you have to need to clean, rework and regenerate it first 01-Sep-19 05:44 AM maybe it's cheaper/easier to buy a new or a refurbished one 01-Sep-19 05:44 AM and yeah, a dirty ion getter pump will contaminate your chamber 01-Sep-19 05:44 AM it's not destroyed, but you've to reclean it then 01-Sep-19 05:47 AM Ok, I will invest in a new one... 01-Sep-19 05:47 AM That and I believe they do have a lifespan to a degree as far as I know. But yea basically any ION pump you get will need a bakeout too. Unless you get a referb or new one and its sealed up and you install it quickly and pump down quickly. Even then a bakeout wouldn't hurt. 01-Sep-19 05:47 AM yep, what conmega says 01-Sep-19 05:56 AM Ok. Have you seen this kit : Controleo3 Reflow Oven Controller (https://www.whizoo.com/) ?IMHO, it could be used for the backing process of some UHV element (with few modification). It's normally used for PCB soldering of SMT component in small oven , But I Thinks this kit could be adapted to a for Baking purpose of some UHV Parts We just need to put on the BIGGEST Oven.... UHV Backing Oven with Hacker's style.... 01-Sep-19 05:56 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/c3_oven-D1185.jpg 01-Sep-19 05:56 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/reflowprofile-C49F2.gif 01-Sep-19 05:59 AM no 01-Sep-19 05:59 AM i mean you could use the controller, of course 01-Sep-19 05:59 AM but not a pizza oven 01-Sep-19 06:00 AM Yess... we need a bigger oven... 01-Sep-19 06:00 AM in theory, yes, but practical: yyy? 01-Sep-19 06:01 AM We will see ... let's try ... 01-Sep-19 06:02 AM but 01-Sep-19 06:02 AM you only need a hood 01-Sep-19 06:02 AM in the simpliest case a pile of aluminium foil 01-Sep-19 06:02 AM with heating strips and or halogen lamps 01-Sep-19 06:02 AM and a cheap thermostat controller switching on and off your heat sources 01-Sep-19 06:05 AM hum... Seems more simple than I thougth first... I like the idea 01-Sep-19 06:05 AM No need to put a temperature probe inside de chamber? 01-Sep-19 06:07 AM no, i mean it's not bad having one, but no 01-Sep-19 06:07 AM Ok 01-Sep-19 06:08 AM only outside probing is okay - place the probes where the most thermosensitive stuff is ... like elastomere (viton et al) gaskets 01-Sep-19 06:08 AM and then slowly ramp up (and later on down of course) 01-Sep-19 06:10 AM to fast can fck up feed-throughs and viewports and maybe could lead to other nasty little leaks 01-Sep-19 06:10 AM and as always keep the complexity of your rig small as possible 01-Sep-19 06:10 AM -> more flanges -> more potential leaks and stuff like that 01-Sep-19 06:13 AM Regarding Ion pump techno. I'm wondering the pro & cons of each techno such as Diode , StarCell and Noble Diode version? 01-Sep-19 06:14 AM ok, starcell has an optimized surface geometry for more l/s per volume/weight of the pump 01-Sep-19 06:14 AM noble diode simply means that some part of the cathods is made of tantalum instead of titanium 01-Sep-19 06:14 AM tantalum keeps even noble gases inside 01-Sep-19 06:14 AM but has a lesser pumping cap for the other gases 01-Sep-19 06:18 AM @yann35 when you bake UHV parts, it's not with a literal oven, but rather wrapping parts in heat tape and insulation and heating things while they are being pumped down 01-Sep-19 06:18 AM Modern ion pumps actually can come with heater elements for baking during pumping. Magnets must be removed first 01-Sep-19 06:21 AM heating strips and aluminium foil is okay in many cases ^^ 01-Sep-19 06:22 AM Cheap and easy. You should use a variac though and bring temperature up slowly, especially if you have viewports or ceramic feedthroughs 01-Sep-19 06:22 AM Or some controller to ramp temp up slow 01-Sep-19 06:25 AM yeah, wrote that above 01-Sep-19 06:29 AM Ah, didn't see 01-Sep-19 06:35 AM Thanks all for your answers 01-Sep-19 08:05 AM Regarding reflow controlelrs and baking out large components. 01-Sep-19 08:05 AM A small aircraft company that an accosiate works for rebuilt a used pizza oven. 01-Sep-19 08:05 AM And then made it temperature controlled and gave it functionality to follow temperature curves. 01-Sep-19 08:05 AM They use it to cure epoxy parts. 01-Sep-19 08:05 AM Reportedly it still smells of pizza when heated up. Even if it has been extensivly cleaned. 01-Sep-19 08:58 AM but pizza smell is not a bad thing 01-Sep-19 09:32 AM I'd be up for some voicechatting today at normal time 01-Sep-19 09:32 AM if anyone else will be around 01-Sep-19 01:26 PM I'm wondering if the characteristics indicated in "l/s" on ion pumps only indicate that the pump will more or less quickly to make the vacuum level ? no doubt, the choice of the number of liters to be pumped per second depends on the volumetric of the vacuum chamber. For a vacuum chamber of 15 to 20 cm3 of volume (+ some pipe and valve trough T pipe and Gauges...) , I hesitate between the 75 l / s or the 150 l / s : Would you have any advice to give me about that choice (objective of vacuum search = 10 ^ -12). what will be the performance gap for my goal? (The vacuum will take longer to get done, is that it?), Is there another parameter to take into account in the choice of l / s? 01-Sep-19 01:28 PM Higher speed = usually better 01-Sep-19 01:28 PM The faster the pump is, the faster it'll reach the desired vacuum 01-Sep-19 01:30 PM ok 01-Sep-19 01:30 PM https://www.norm.gr/documents/Vacuum-Technology-Book-II-Part-2.pdf 01-Sep-19 01:30 PM read this 01-Sep-19 01:34 PM Yes I will. Thanks for the doc 02-Sep-19 06:53 AM moin! 02-Sep-19 10:37 AM enjoying the US holiday? 02-Sep-19 10:30 PM I wonder, has anyone here tried electron beam welding? 02-Sep-19 10:30 PM I'm curious how low power you can go 02-Sep-19 10:30 PM Most the welders I see are in the multi-keV range and multi-kW range in terms of power 02-Sep-19 10:37 PM There was a discussion in here a while ago about using a sem as a micro ebeam welder, I forget who brought it up though. The math seemed reasonably though 02-Sep-19 10:37 PM there exist EBW systems that act as low mag SEMs 02-Sep-19 10:37 PM https://www.youtube.com/watch?v=grzbTs69wuw 02-Sep-19 10:37 PM here's one 02-Sep-19 10:37 PM For all intents and purposes it's a SEM on steroids 02-Sep-19 10:37 PM Except the steroids are in the electron gun, not the resolution 02-Sep-19 10:41 PM Yeah I remember that discussion, came up about one of the hackaday prize entries 02-Sep-19 10:41 PM I don't think a sem would work 02-Sep-19 10:41 PM It could, if your materials are extra thin 02-Sep-19 10:41 PM Micro amps of current would really get you nowhere 02-Sep-19 10:41 PM Yeah, if foils or wire bonding maybe 02-Sep-19 10:41 PM You can definitely boil some materials, I've seen it happen 02-Sep-19 10:41 PM There's mention of dielectric welding 02-Sep-19 10:43 PM Like plastics or ceramics? 02-Sep-19 10:43 PM I'm not sure what kind, just "welding of dielectric materials" 02-Sep-19 10:44 PM It could work for low melting point materials or very thin material welds, but not any larger things really 02-Sep-19 10:44 PM I like that at this point an SEM is just thrown in as a package deal 02-Sep-19 10:44 PM "this welder is also a microscope" 02-Sep-19 10:45 PM Fair lol 03-Sep-19 02:56 AM Meh, my TCP040 (attached to a TPH050) in my sputter just died, emitting magic smoke. Any hints? I wasn't able to find more information other than https://fusor.net/board/download/file.php?id=6862 ,especially no complete schematics. Can I typically use a different (Pfeiffer) turbopump controller? 03-Sep-19 02:56 AM It had worked fine for quite a while, but then it shut down the TP in the middle of operation, and blew a fuse. 03-Sep-19 03:20 AM Ah, I found http://www.hsdengineering.com/images/pfeiffer_table.pdf 03-Sep-19 04:35 AM @AdamMcCombs me 03-Sep-19 04:35 AM removing apertures n stuff 03-Sep-19 06:42 AM moin! 03-Sep-19 09:48 AM @tmbinc DIY it! 03-Sep-19 09:48 AM It's really simple 03-Sep-19 09:48 AM Common power, a fet for each phase, and two hall effect sensors 03-Sep-19 11:22 AM I've decided to go with air to actuate the vat valve 03-Sep-19 11:22 AM It closes quietly(minus the sound of the $10 car compressor), but when it's given pressure to open, hooooooo boy 03-Sep-19 11:22 AM pressure builds, builds, builds, then CLACK and the lock mechanism snaps open, then it quickly retracts into the body 03-Sep-19 11:22 AM definitely need to build a muffler for this mini hellpump though 03-Sep-19 01:35 PM @N00N did you ever try anything with it? 03-Sep-19 03:08 PM still trying to figure out why the extra lubrication line looped into itself.. maybe a base unit that if some other type would have more lube points or something.. 03-Sep-19 03:08 PM oh, and I need new bellows for the column, and likely the ways of that saddle 03-Sep-19 03:08 PM may just do the leather trick à la Stffean Gotteswinter 03-Sep-19 03:08 PM he got proper replacement bellows for his tool and cutter grinder, though 03-Sep-19 03:08 PM oh, neat, bellows are made to some of the vacuum fitting standards... anyone use them? what is the end result 03-Sep-19 04:00 PM @tmbinc I have a working TCP040 controller. Let me know if I can help with anything 03-Sep-19 04:00 PM this isn't really vacuum related, should go offtopic/machining instead 03-Sep-19 04:00 PM simply came across metal bellows in ISO format 03-Sep-19 09:23 PM water spewing up from teh manhole cover in the street in front of my house (not the manhole cover/drain that is at the foot of my patio steps at the sidewalk).. reported it 03-Sep-19 09:51 PM a firetruck showed up, noted it, left.. and a few mins later the water stopped spewing 03-Sep-19 09:52 PM thus we conclude that firetrucks make water disappear 03-Sep-19 09:52 PM it's only logical 04-Sep-19 12:06 AM apparently it was sewage, not mains water, unst 04-Sep-19 04:54 AM Thats bad... you must have a backflow prevention valve if your showers/toilets/etc didn't start backing up 04-Sep-19 07:15 AM Don’t know how it goes where you live but we have separate storm water sewers and sanitary sewers. 04-Sep-19 08:38 AM @AdamMcCombs nope I'm scared fckn things up 04-Sep-19 08:38 AM but have read paper about doing it, does that count? 04-Sep-19 09:51 AM @Conmega talked wtih the dudes outside a lil as I took out the trash, and they were asking if I had a smell inside... but nope 04-Sep-19 09:51 AM he seemed very relieved when I told him that too 04-Sep-19 11:29 AM that rose isnt doing too good... 04-Sep-19 06:33 PM utility guys showe dback up 04-Sep-19 06:33 PM for the sewer 06-Sep-19 01:01 PM Greetings from Switzerland 06-Sep-19 01:01 PM It is cold and expensive here. 06-Sep-19 02:21 PM OOoooOOoo... that's been the only place on my vacation list for a while now.. bicycle aorund the alps and tour watch manufacturer workshops 06-Sep-19 07:02 PM I somehow found a store that sells all the cool electronics, chemical, and glassblowing components, but for 2-10x the prices of Sigma-Aldrich and the like 06-Sep-19 07:02 PM How are they still in business!? 06-Sep-19 07:02 PM 2lb of beeswax for $32, 2.5L of acetic acid for $172 06-Sep-19 07:02 PM 500ml of FeCl for $40 06-Sep-19 07:02 PM On another note, I randomly reconnected with an old acquaintance and now he's donating a high-end oxygen concentrator towards the DIY tube effort! Yay! 06-Sep-19 11:07 PM moin! 07-Sep-19 12:32 AM moin 07-Sep-19 12:32 AM so we are ready for engines with LOX? 07-Sep-19 12:32 AM i mean getting spaceborn is kinda ultimative vacuum challenge? 07-Sep-19 10:32 AM liquid oxygen? 07-Sep-19 10:37 AM need to get some UDMH as well 07-Sep-19 09:50 PM der general! 09-Sep-19 07:08 AM @Applied_Ion you've been named! https://hackaday.com/2019/09/09/plasma-powered-thrusters-for-your-homebrew-satellite-needs/ 09-Sep-19 07:08 AM (at least I never came across your name before) 09-Sep-19 09:29 AM Yay, my vacuum stuff arrived 09-Sep-19 09:29 AM Finally assembling something resembling a vacuum system 09-Sep-19 09:29 AM Still missing the key piece, a KF50 to ISO63 adapter 09-Sep-19 10:43 AM I messed up and ordered one too few KF50 clamp/ring sets :< 09-Sep-19 10:43 AM But I still need extra parts, so I'll throw that into the next order 09-Sep-19 11:56 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190909_215237-2B478.jpg 09-Sep-19 11:59 AM @nmz787 yeah lol, only a matter of time before it was more publicly revealed, though wasn't expecting it through a hackaday article! 09-Sep-19 01:44 PM It could be that nobody else understood what it was about and that it really only applies to micro sats and HaD readers have a high population that would understand the application that they would move faster to publish it. I write for them from time to time and always looking for something interesting to give them. 09-Sep-19 11:04 PM moin! 09-Sep-19 11:04 PM on the train from Switzerland to Germany. Unofficial Vacuum Hackers meetup tonight! 10-Sep-19 12:30 AM The old "vacuum train" 10-Sep-19 12:30 AM I'm at this thing called the Semiconductor Research Corporation TECHCON 10-Sep-19 12:30 AM chairing two sessions tomorrow : bioinfluenced computing and bioinfluenced storage 10-Sep-19 12:30 AM Basically just introducing the speakers and keeping them to 15 mins max time 10-Sep-19 09:50 AM How did the vacuum meetup go? 10-Sep-19 09:50 AM Was there any evacuation, or was the atmosphere normal? 10-Sep-19 11:10 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-E847A.jpg 10-Sep-19 12:59 PM We want a picture of Lukas drinking a glass of dielectric fluid 10-Sep-19 01:41 PM :D 10-Sep-19 01:41 PM you'll have to ask @piGuy about that, his wife took the photos ^^ 10-Sep-19 01:51 PM but I have to say 10-Sep-19 01:51 PM it was a very fun evening! 10-Sep-19 01:51 PM more of you guys should come to munich 10-Sep-19 02:28 PM I drank my first beer ever 10-Sep-19 02:29 PM coming from a american visiting Bavaria this can mean one of two things :P 10-Sep-19 10:51 PM Dielectric fluid can just be be some form of vegetable oil, seems legit and paleo too ;) 11-Sep-19 01:26 AM yes, but... 11-Sep-19 08:59 AM I would not use vegetable oil. It’s carbon break down point is too low. It will do in a pinch but if anything carbon bearing gets in it, it will eventually break down. Mineral oil is a better cheap choice. 11-Sep-19 08:59 AM Oh and by the way. Vegetable oil is not paleo. Look up Vinnie Tortarich. He gives excellent break downs on keto and oil. Olive oil is a far better and coconut or avacado oils even better still. But not the chat room for this topic. 11-Sep-19 09:01 AM well our huge pulsecaps have castor oil in them 11-Sep-19 09:01 AM Castor is good 11-Sep-19 09:01 AM Vegetable oils with the solvent extraction they use has lots of other garbage in it. 11-Sep-19 09:01 AM It’s made to be cheap 11-Sep-19 09:01 AM Castor oil being generally for medical and industrial use has lower dissolved water and generally tighter source controls 11-Sep-19 09:01 AM Vegetable oil can me a mix of any number of things. Rape seed, sunflower, cotton, etc. 11-Sep-19 09:26 AM I have anhydrous oil for my alkali metals.. I'm sure that would be decent 11-Sep-19 09:26 AM or do a NurdRage and use unscented baby oil, which is basically the same thing, just over the counter 11-Sep-19 09:26 AM most of the anh/long chained ones are also saturated, ie, no pi bonds.. so they dont oxidize like many cooking oils do 11-Sep-19 09:26 AM so they will never go 'rancid' 11-Sep-19 09:26 AM they are likely mostly synthetic from petroleum based starting points, but that shouldn't matter much if that's what you need 11-Sep-19 06:35 PM I had this really weird idea 11-Sep-19 06:35 PM what if I use a microchannel plate stage with/without a phosphor plate, to use as an SEM detector? 11-Sep-19 06:35 PM not sure if that makes any more sense than just using a bare electron multiplier, but MCPs have quite a high gain 11-Sep-19 06:56 PM Do you need the spatial resolution of an MCP in that application? 11-Sep-19 06:56 PM A bare multistage electron multiplier could give you more gain I think when space is not a problem 11-Sep-19 08:20 PM it might... 11-Sep-19 08:20 PM resolution isn't required of course 12-Sep-19 12:46 PM @Charles I actually meant fruit oils :p 12-Sep-19 12:46 PM Or nut oils 12-Sep-19 02:55 PM re: electron multiplier.. I have the idea of using MgOx/AlOx on nichrome mesh.. so before/during drawing a vacuum it can heta itself, converting any hydroxides back into oxides.. a series of stacks of them with voltage difference would create some multiplication.. havent tested it at all yet though 12-Sep-19 02:55 PM can be relatively easily made with Mg + MeOH (becareful for runaways, plus it produces hydrogen gas), then dip the mesh into the solution, bring out, let evaporate, repeat 12-Sep-19 03:28 PM You can just use a beheaded PMT for it 12-Sep-19 03:28 PM but that's what Zworykin did, and it's exactly what the Everhart-Thornley detector was made to outperform 12-Sep-19 03:28 PM which, logically, doesn't make sense - how could adding more conversion steps creates more signal 12-Sep-19 03:28 PM but once you understand why, it does actually make sense 12-Sep-19 11:33 PM @Deleted User can you enlighten us as to /why/? 12-Sep-19 11:42 PM In short, the way I understand it is: When you accelerate the electrons very hard inside the faraday cage, you give them a lot more energy - so when a single electron with a lot of energy slams into a scintillator, it creates thousands of photons, which get converted into thousands of electrons at the photocathode in the PMT. I believe that initial gain of 110^3 to 110^4 is what makes the Everhart-Thornley detector much more sensitive than just a dynode electron multiplier. In theory, it should be possible to make an electron multiplier with enough stages to get the same efficiency, but it'd be huge. 12-Sep-19 11:42 PM I could be wrong on this, since I didn't read up on exactly why the ET detector is now used instead of electron multipliers, but that's my understanding of why it's better. 12-Sep-19 11:42 PM Someone like @AdamMcCombs who actually knows what they're doing could probably explain it better. 13-Sep-19 02:03 PM Yeah you pretty much got it 13-Sep-19 02:03 PM Et also collets a lot more electrons from the rest of the chamber, which drastically improves image performance 13-Sep-19 02:03 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190912_165846-E4E78.jpg 13-Sep-19 02:03 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190912_164228-423B1.jpg 13-Sep-19 02:11 PM Some see a hoarding problem 13-Sep-19 02:11 PM I see a goldmine 13-Sep-19 02:11 PM that conflat chamber is very nice 14-Sep-19 12:49 AM oh jeez 14-Sep-19 02:15 AM what is that chamber for? 14-Sep-19 11:57 AM Sale, I'm guessing 14-Sep-19 07:09 PM Actually no. Its for uh... stuff. 14-Sep-19 08:46 PM I re arranged my chemicals. Acids got moved to a separate cabinet, accept nitric of course. That lives in a completely different place. Separated all the hydrocarbon bearing liquids to another location, and segregated the magnesium and aluminum nitrates to another spot. Probably should have done this before. Hopefully the white mystery precipitate does not come back. 14-Sep-19 08:46 PM Dry goods and non reactives are all that are left in the original spot. 15-Sep-19 11:49 AM Joined the server. 15-Sep-19 01:47 PM Joined the server. 15-Sep-19 02:28 PM Welcome @Epilogis and @pelukkk 15-Sep-19 02:48 PM Joined the server. 15-Sep-19 02:52 PM Joined the server. 15-Sep-19 03:21 PM Joined the server. 15-Sep-19 11:43 PM Joined the server. 15-Sep-19 11:44 PM Welcome all the new folks! 16-Sep-19 04:04 AM Wow, so many new people 16-Sep-19 04:04 AM welcome! 16-Sep-19 04:04 AM if I may ask, how did you learn of our server? 16-Sep-19 05:51 AM Joined the server. 16-Sep-19 06:13 AM it was not me!! 16-Sep-19 06:38 AM looks over to N00N and suspects them 16-Sep-19 08:59 AM I may or may not have mentioned it on a Marco Reps video that teased high vacuum gear 16-Sep-19 09:03 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190915_011634-C6156.jpg 16-Sep-19 09:03 AM Seems like your garage is now clogged with SEMs 16-Sep-19 09:03 AM Yeah there's a traffic jam at the moment 16-Sep-19 09:03 AM I spilled a bunch of antifreeze while getting the shop ready 16-Sep-19 09:03 AM You'll need a roots-style plunger to get all it out 16-Sep-19 09:04 AM So the bay this scope goes into is covered in absorbant right now 16-Sep-19 09:04 AM Yeah that or a pallet jack 16-Sep-19 09:04 AM Still, having a garage full of SEMs sounds like very non-issue to someone with precisely zero SEMs 16-Sep-19 09:05 AM Yeah an I'm still over here trying to get more 16-Sep-19 09:05 AM The person I got the sem from threw in another goodie as well 16-Sep-19 09:05 AM If someone tosses a benchtop SEM in the bin of a university, I call dibs 16-Sep-19 09:06 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190911_175131-31E0E.jpg 16-Sep-19 09:06 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190911_175354-7752D.jpg 16-Sep-19 09:06 AM A vacuum system? 16-Sep-19 09:06 AM Yeah 16-Sep-19 09:06 AM Looks very tentacly 16-Sep-19 09:06 AM Fully self contained and came with some instrumentation 16-Sep-19 09:06 AM That’s a nice looking system right there 16-Sep-19 09:06 AM Got a rga as well 16-Sep-19 09:06 AM And a sem cryo stage 16-Sep-19 09:07 AM Do you just get SEMs donated at this point? 16-Sep-19 09:07 AM Also 2 wavelength dispersive spectrometers 16-Sep-19 09:07 AM On occasion yeah 16-Sep-19 09:07 AM I did pay for this one but it was basically covering what this person had into it 16-Sep-19 09:09 AM That looks to be a 6” nrc or latter varian versions diff pump and a one of the bigger Welch pumps. 16-Sep-19 09:09 AM I also got a massive pile of spare parts 16-Sep-19 09:09 AM Yeah no it's a really big nice pumping system 16-Sep-19 09:10 AM Some day you will be looking to toss away some SEMs, and that is when I will swoop in 16-Sep-19 09:10 AM That’s ready to make some nice tubes. Just put a coupler port on one of those arms and you are off and running 16-Sep-19 09:10 AM Yeah it's got plenty of arms 16-Sep-19 09:10 AM I'm still terrified of my tubes breaking when I'm pumping on the turbo 16-Sep-19 09:10 AM Hell. With that you can do some serious large pipe leak testing 16-Sep-19 09:11 AM I have a gate valve, but it won't save me from a tube shattering during high vac pumpdown 16-Sep-19 09:11 AM Hmmm.... I can put my rga on it 16-Sep-19 09:11 AM Generally small glass tubes very very rarely break on the pump. 16-Sep-19 09:12 AM I think it's only a 100 amu rga but it's tinny which is nice 16-Sep-19 09:12 AM Leak, yes, all the time, but actually break. Hardly ever. 16-Sep-19 09:12 AM I'll build in some gas load detection in my turbo driver 16-Sep-19 09:13 AM You are more likely to break them by accidentally bumping them with something and breaking them that way 16-Sep-19 09:13 AM a 100 amu rga is still plenty for a leak detector 16-Sep-19 09:13 AM Yeah 16-Sep-19 09:13 AM That’s why you never use turbos on tubes too. If something breaks, turbos do not like the little glass particles 16-Sep-19 09:13 AM And I can see someone carbon contamination 16-Sep-19 09:14 AM I'll be choking it a little, but I'm putting a fine mesh centering ring on the pump @Charles 16-Sep-19 09:14 AM it'll happily take particles smaller than the mesh 16-Sep-19 09:14 AM (ish) 16-Sep-19 09:14 AM it took my finger once and still runs.... 16-Sep-19 09:14 AM happily 16-Sep-19 09:14 AM angry turbo noises 16-Sep-19 09:15 AM Nothing about a sudden break, sudden vent, small glass bits, and a fully spun up turbo sound happy 16-Sep-19 09:16 AM sudden vent is what scares me most 16-Sep-19 09:16 AM a finger is nothing compared to the entire chamber jumping to a lot of mTorr 16-Sep-19 09:16 AM A lot 16-Sep-19 09:16 AM this is why I want an old turbodrag! 16-Sep-19 09:16 AM I just love the soothing sound of a well sealed system, a fresh Welch pump, and the silent diffusion pump just humming along. 16-Sep-19 09:17 AM you can vent a full speed turbodrag over and over and they'll just make angry noises and keep running 16-Sep-19 09:17 AM Maybe 760000? 16-Sep-19 09:17 AM What? 16-Sep-19 09:17 AM 760000 militor 16-Sep-19 09:17 AM something like that 16-Sep-19 09:18 AM If the backing pump is still going maybe a bit less 16-Sep-19 09:18 AM my forepump can definitely keep sucking down a chamber that is venting through a suction tube(7mm od, 5.5mm ID) 16-Sep-19 09:18 AM just not very low 16-Sep-19 09:18 AM maybe a few hundred torr 16-Sep-19 09:18 AM though at that point it will sound very angry 16-Sep-19 09:20 AM Yeah labs using Welch and rv pumps for high gas load applications makes me cringe 16-Sep-19 09:20 AM I mean I do it as well 16-Sep-19 09:20 AM But I also cringe then 16-Sep-19 09:20 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190911_232024-A0E2D.jpg 16-Sep-19 09:20 AM The sem is turbo pumped as well 16-Sep-19 09:21 AM securely mounted 16-Sep-19 09:21 AM Naturally 16-Sep-19 09:21 AM This was a after thought for jeol 16-Sep-19 09:21 AM So there is zero provision for proper transportation hardware 16-Sep-19 09:21 AM Getting the thing into my shop though... 16-Sep-19 09:21 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190914_132750-5F5AB.jpg 16-Sep-19 09:22 AM I swear, vacuum stuff is timeless 16-Sep-19 09:22 AM Give it a bit of a buff, and it looks new 16-Sep-19 09:24 AM It took a 6 point turn to get the truck in just the right spot to get the lift gate in the door 16-Sep-19 09:25 AM A small obstacle :P 16-Sep-19 09:26 AM I've dealt with this every time I have to move a system in or out 16-Sep-19 09:27 AM at some point you'll just upgrade to a hangar 16-Sep-19 09:27 AM Believe me I'm looking 16-Sep-19 09:27 AM I really need more shop space 16-Sep-19 09:27 AM I've got more systems that need to come in the shop 16-Sep-19 09:27 AM And by really I mean desperately 16-Sep-19 09:45 AM Ugh. Everything just blew up here at work firmware wise. We thought we were Good Friday and ready to reprogram everything but now I found another problem our fix may have caused. 16-Sep-19 10:05 AM Of course, fixing code always leads to more bugs 16-Sep-19 10:05 AM You just fix until you can sweep the new bugs under the rug without affecting the application 16-Sep-19 11:03 AM We found it. One of the files was wrong when we built the hex. 16-Sep-19 11:04 AM Well it could have been a lot worse 16-Sep-19 05:48 PM Joined the server. 16-Sep-19 06:36 PM @AdamMcCombs have you got that alcatel hooked up to your sputtering system yet? 16-Sep-19 07:57 PM Kinda, there's a leak in it I have to chase down 16-Sep-19 08:47 PM what kind of sputtering system 16-Sep-19 08:47 PM Just a DC system for sem 16-Sep-19 10:27 PM ah ok 16-Sep-19 11:50 PM hey, im poring over boston craigslist atm, and just came across something I feel like someone here might have more use for 16-Sep-19 11:50 PM https://boston.craigslist.org/nos/ele/d/medford-avcom-psa-45d-mhz-portable/6979617774.html 16-Sep-19 11:50 PM Im ngl, kinda want it but dont have the money, and I feel like the frequency range would be good for debugging some things 16-Sep-19 11:50 PM if anyone wants to use me as an intermediate to get this, just lmk 17-Sep-19 12:00 AM I found a wonderful 640x512 thermal camera on eBay, but as always it comes at a time where I have no money to spare 17-Sep-19 12:00 AM Maybe I just need to sell my PTZ thermal unit and keep the money in the back pocket for this exact purpose 17-Sep-19 06:25 AM 300usd for something that limited is IMO too much 17-Sep-19 06:25 AM I have managed to get far better gear for less 17-Sep-19 06:25 AM my HP 8555A (9kHz-18GHz) was 150eur from a hamfest, my R&S CRTU was 250eur (10-2700MHz spectrum, 100kHz-2700MHz signal generation and power meter, can also function as a GSM basestation for testing handset regulatory compliance) 17-Sep-19 06:25 AM And that satellite IF frequency range does not even cover any widely used ISM bands. 17-Sep-19 06:25 AM It only covers 1800MHz and 1900MHz cellular bands, the DECT 6.0 USA DECT band and partially the 2100MHz 3g&4g band. 17-Sep-19 09:39 PM I found a really interesting vintage soviet oil diffusion pump 17-Sep-19 09:39 PM https://i.spirit.re/tKQXP.jpg 17-Sep-19 09:39 PM All glass, and only 13.3*10^-3 Pa @ 5l/s 17-Sep-19 09:39 PM Not really useful today, but quite an interesting design. 18-Sep-19 06:10 AM stacks of percolators? 18-Sep-19 06:10 AM and some ebedded calrod heaters in the bases? 18-Sep-19 06:10 AM (trying to figure out the concept of how it works in my head) 18-Sep-19 06:10 AM air cooled? 18-Sep-19 06:10 AM and I guess what I was calling a percolator are really just the jets/nozzles 18-Sep-19 08:52 AM moin! 18-Sep-19 08:55 AM hio @piGuy 18-Sep-19 12:28 PM My first borosilicate to tungsten seal! 18-Sep-19 12:28 PM https://i.spirit.re/cL28E.png 18-Sep-19 12:28 PM Very ugly, but there's no cracks or bubbles! Over-oxidized though. 18-Sep-19 12:28 PM tungsten burns yellowish-white 18-Sep-19 12:28 PM but cleaning it directly in the flame is very handy 18-Sep-19 12:28 PM I need to figure out how to make a crappy light bulb in this 6mm tube. 18-Sep-19 12:50 PM Don't need it, but I want it. https://www.equipnet.com/auctions/ge-sensing-and-inspection-tech-gmbh-nanome%7cx-listid-652132/ 18-Sep-19 02:14 PM @piGuy there's a few very low cost high end x-ray systems in Japan if you want to get one 18-Sep-19 02:14 PM all are under $3000 18-Sep-19 02:14 PM some under $400 18-Sep-19 02:14 PM the problem is shipping and getting them out 18-Sep-19 02:14 PM (that's why they're so cheap) 18-Sep-19 02:14 PM https://page.auctions.yahoo.co.jp/jp/auction/f337188811 18-Sep-19 02:15 PM Japan hm? 18-Sep-19 02:15 PM $2500 for a 2015 microfocus system, 0 bids 18-Sep-19 02:15 PM https://page.auctions.yahoo.co.jp/jp/auction/v600488325 18-Sep-19 02:15 PM Here's a relatively recent microtomograph... for $700 18-Sep-19 02:15 PM the keyword is "X線" 18-Sep-19 02:15 PM "x sen", means x-ray 18-Sep-19 02:15 PM or a working x-ray microscope for $850 18-Sep-19 02:15 PM https://page.auctions.yahoo.co.jp/jp/auction/d354003767 18-Sep-19 02:15 PM but they're all very heavy :( 18-Sep-19 02:40 PM So horrific shipping. Unless using sea freight, when it's only bad. 18-Sep-19 02:42 PM And the logistics within the country 18-Sep-19 02:43 PM Some broker like rinkya will help with that. 18-Sep-19 02:43 PM I mention rinkya because I have used it. 18-Sep-19 02:43 PM Rinkya, buyee 18-Sep-19 02:43 PM They all seem to have a limit around 30kg 18-Sep-19 02:43 PM Ah 18-Sep-19 02:43 PM though at 30kg it's not that expensive 18-Sep-19 02:43 PM Was just about to mention that I never went over 27kg 18-Sep-19 02:43 PM airmail is $200-300ish 18-Sep-19 02:43 PM 24kg is like 300eur via fedex. 18-Sep-19 02:43 PM Never bid on cheap radios. 18-Sep-19 02:44 PM I just want a microfocus source ;~; 18-Sep-19 02:44 PM Thought I was buying one for 15eur+fees. Got 12pcs+some accessories. 18-Sep-19 02:44 PM I have a beautiful x-ray detector 18-Sep-19 02:44 PM But nothing to pew pew the x-rays out of 18-Sep-19 02:45 PM so that ship that ~20-30eur pile of radios cost 300eur. 18-Sep-19 02:45 PM Well that's a lie, but nothing to pew pew the microfocus x-rays out of 18-Sep-19 02:45 PM Even better, the radios are trash. :DDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDDD 18-Sep-19 02:45 PM aw 18-Sep-19 02:45 PM but you can sell a few to make up for the loss 18-Sep-19 02:45 PM At least I was properly employed back then. 18-Sep-19 02:45 PM Lol that's gona be a LOOOOONG game. 18-Sep-19 02:46 PM there's these weird chinese sites that claim to be reselling used gear 18-Sep-19 02:46 PM https://i.spirit.re/OnqZP.jpg 18-Sep-19 02:46 PM look at the URLs under each image 18-Sep-19 02:46 PM they all lead to some weird Chinese number-word site 18-Sep-19 02:46 PM If the image ever loaded... 18-Sep-19 04:24 PM I'm frustrated 18-Sep-19 04:26 PM why? 18-Sep-19 04:29 PM I bought a tig welder 18-Sep-19 04:32 PM well if you don't need / want it you can always send it my way 18-Sep-19 04:32 PM I'm making a stainless steel vacuum chamber 18-Sep-19 04:32 PM I laser cut all the parts 18-Sep-19 04:32 PM 10mm thickness 18-Sep-19 04:32 PM But with the welding heat all parts are warping and deforming 18-Sep-19 04:32 PM I'm thinking just use small racks of weld and seal everything with silicone 18-Sep-19 04:32 PM Tacks* 18-Sep-19 04:32 PM Maybe silicone outgassing is not too bad 18-Sep-19 04:32 PM For an electron gun 18-Sep-19 04:33 PM if you want to glue something for vacuum application always use epoxy 18-Sep-19 04:33 PM is the warping so bad it can't be fixed with a grinder? 18-Sep-19 04:34 PM Yes. The warping is like 3mm 18-Sep-19 04:34 PM Is horrible 18-Sep-19 04:35 PM ouch 18-Sep-19 04:36 PM Here in Chile I can buy epoxy glue, but no one can tell you about the outgassing 18-Sep-19 04:36 PM Do you think any epoxy is better than silicone? 18-Sep-19 04:36 PM yes, definitely 18-Sep-19 04:36 PM I got my chamber down to e-8 with tonnes of 2k epoxy in it 18-Sep-19 04:36 PM the epoxy will do a lot of outgassing at first, but once that's done (usually a day of baking at 80-100°C for me) it will be a perfect seal 18-Sep-19 04:37 PM Just note that a LOT of epoxies will outgas like someone after a bean soup 18-Sep-19 04:37 PM Even after baking 18-Sep-19 04:37 PM Loctite Hysol 1C is known to be vacuum-safe and temp-safe 18-Sep-19 04:37 PM TorrSeal is the same thing but costs more and is a different brand 18-Sep-19 04:37 PM Oh and of course JB Weld, but you'd have to buy that online 18-Sep-19 04:38 PM 2k is a common epoxy or is more specific? 18-Sep-19 04:39 PM 2k is just two component 18-Sep-19 04:39 PM JB Weld is common and very cheap, but only in the US 18-Sep-19 04:39 PM Not hard to buy with shipping though 18-Sep-19 04:39 PM I guess it's a german name ("2 komponenten") 18-Sep-19 04:39 PM Jajaja 18-Sep-19 04:39 PM Uhu endfest is my goto, but that's a very german product as well ^^ 18-Sep-19 04:40 PM Hysol is available worldwide if you can find it 18-Sep-19 04:40 PM JB Weld is available, but only online 18-Sep-19 04:40 PM Just make sure you always buy the standard/high strength and slow setting version of every epoxy you try 18-Sep-19 04:40 PM Fast setting ones just have too much activator, which could result in outgassing 18-Sep-19 04:41 PM Good to know 18-Sep-19 04:41 PM I literally went to China and bought this tig welder 18-Sep-19 04:41 PM 400A 18-Sep-19 04:42 PM a 400A tig? 18-Sep-19 04:42 PM Can weld very thick parts 18-Sep-19 04:42 PM Yes 18-Sep-19 04:42 PM if anyone wants to organize a group buy of Hysol 1C, I'd definitely be in 18-Sep-19 04:42 PM they're not even that expensive 18-Sep-19 04:42 PM ~120g for $20 18-Sep-19 04:43 PM I hate your developed countries 18-Sep-19 04:43 PM I'm in Belarus lol 18-Sep-19 04:43 PM you can't buy anything locally here 18-Sep-19 04:44 PM You can buy anything 18-Sep-19 04:44 PM I buy everything on ebay, sometimes through reshippers 18-Sep-19 04:45 PM Okay. I will glue everything 18-Sep-19 04:45 PM If doesnt works will be Lukas fault 18-Sep-19 04:47 PM ^:D 18-Sep-19 04:47 PM fair enough, I think I can live with that 18-Sep-19 04:47 PM good luck and good night! 19-Sep-19 06:20 AM I was going to ask if jb weld was available outside the US 19-Sep-19 06:20 AM I've used a reshipper (sometimes called a proxy shipper) only once.. for some stuffed animal bear in japan 19-Sep-19 08:36 AM I don’t see anything that would preclude it from being available outside of the US apart from shipping costs. One of the shows I engineer for had the owners of JB weld on to interview. Nice people. JB was the initials of the chemical engineer their father had employed. They were looking for an adhesive to patch holes in cast iron exhaust manifolds, hence the steel in it to approximate the thermal expansion coefficient of cast iron. Like all other ubiquitous products they soon found other uses for it. 19-Sep-19 10:40 AM @chucrut what country is your lab in? 19-Sep-19 11:55 AM @nmz787 I'm located in Chile 19-Sep-19 11:55 AM chile reminds me of somebody 19-Sep-19 11:56 AM no thanks I've got a sweater @Pan Da 19-Sep-19 11:57 AM i know you sweat much, yes 19-Sep-19 11:57 AM Sweaty hands? 19-Sep-19 11:57 AM Bad for high voltage 19-Sep-19 11:57 AM Lukas, you need to retire 19-Sep-19 11:58 AM I'll retire when I'm dead 19-Sep-19 11:58 AM found it: that guy https://ludens.cl/ 19-Sep-19 11:58 AM did some great stuff, reading through his page is great fun 19-Sep-19 11:58 AM but i think after starting to build his round house he didn't post much anymore 19-Sep-19 12:00 PM Round houses are for hippies 19-Sep-19 12:44 PM my jeans are Round-House brand.. american made 19-Sep-19 12:44 PM I need some extra pairs before autumn really sets in 20-Sep-19 12:24 AM I read up a little on how TOF spectrometers work 20-Sep-19 12:24 AM it's... very intuitive, actually 20-Sep-19 12:24 AM and the math fits onto one page! 20-Sep-19 12:24 AM I wonder if it's possible to build one at home 20-Sep-19 12:24 AM then bolt a nanosecond laser onto it, and you've got a scary looking acronym, MALDI TOFMS 20-Sep-19 05:57 AM I am interested in mass specs (I'm a bit into chemistry).. I have a book on them, but only a chapter or so on the construction, mostly quadrapole 20-Sep-19 05:57 AM this one: https://www.springer.com/gp/book/9783319543970 20-Sep-19 05:57 AM I wanted more info on the construction 20-Sep-19 05:57 AM I didnt read it all the way though 20-Sep-19 05:57 AM it is on libgen 20-Sep-19 10:01 AM @Deleted User did you find that info in a single article/book? Or spread out? 20-Sep-19 10:11 AM spread out 20-Sep-19 10:26 AM I just bought this TOF Spectrometer chamber for $35 20-Sep-19 10:26 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/s-l1600-5B166.png 20-Sep-19 10:26 AM It is a MALDI TOF chamber with a reflectron and various ion gates and stuff 20-Sep-19 10:29 AM ... what else can you buy for $35? ;~; 20-Sep-19 10:29 AM 3 viewports and quite a few feedthroughs. Should be possible to adapt the two end ports to ISO flanges 20-Sep-19 10:29 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/s-l1600-77CE7.png 20-Sep-19 10:29 AM https://www.ebay.com/itm/Bruker-ULTRAFLEX-TOF-TOF-MS-Detector-/133165161593?nma=true&si=vFaIXGO7Lzo4QqzM9a2jyeIbUq0%253D&orig_cvip=true&nordt=true&rt=nc&_trksid=p2047675.l2557 20-Sep-19 10:29 AM Got that as well for $35 20-Sep-19 10:30 AM that chamber would be perfect for a DIY SEM 20-Sep-19 10:30 AM Altogether including shipping and tax is $125, should arrive next Monday 20-Sep-19 10:30 AM Yeah 20-Sep-19 10:30 AM Unfortunately that "detector" is probably not actually a detector 20-Sep-19 10:35 AM @Mason_Yu glad you grabbed it, I was considering but thought best to keep to trying to finish existing projects first... Could be years and years before i am ready to build my own 20-Sep-19 10:35 AM Likely a precursor ion selector 20-Sep-19 10:35 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-6E2AE.png 20-Sep-19 10:35 AM I also was wary that it wasn't a full detector 20-Sep-19 10:35 AM The ultra flex machine looks quite large 20-Sep-19 10:36 AM Yeah I probably should finish my current projects first lol 20-Sep-19 10:36 AM But this seller is close to me and shipping is cheap 20-Sep-19 10:36 AM "but it was only $70 before shipping!!!" 20-Sep-19 10:36 AM That too 21-Sep-19 12:25 AM woah 21-Sep-19 06:42 AM Joined the server. 21-Sep-19 06:14 PM Has anyone here reverse-engineered older Hamamatsu x-ray heads? 21-Sep-19 06:14 PM There's tons of them on eBay, some for just aboooout acceptable prices, so I was thinking of getting one. I know someone reversed a Glenbrook/Oxford head a while ago, but there's so many Hamamatsu heads without controllers. 21-Sep-19 06:14 PM I'm talking about these: 21-Sep-19 06:14 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Hamamatsu-Photonics-L7902-X-ray-Tube-Unit-996DE.png 21-Sep-19 07:32 PM Building a filament flashing cart from stuff laying around the place. Welch 1402 and a CVC MCF 60 pump. 20 amp 30 volt filament supply on a variac and a thermocouple gauge. All built from things laying in my garage. With the acception of the harbor freight cart nothing in this system is less than 50 years old! 21-Sep-19 07:32 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_7240-71341.JPG 24-Sep-19 10:42 AM Anybody know anything about solar cells? I'm interested in playing with monocrystalline cells (Sunpower C60). I have one that is bare and unencapsulated/unprotected. I noticed it seems to absorb stuff like a sponge. Accidentally touched it with my bare thumb and my thumbprint eventually just disappeared and left a sort of oil stain on it. Any way to clean it? Solvents, plasma? 24-Sep-19 12:17 PM https://news.fnal.gov/2019/09/cool-and-dry-a-revolutionary-method-for-cooling-a-superconducting-accelerator-cavity/ 24-Sep-19 12:17 PM I wonder why no hobbyist has ever built an RF accelerator 24-Sep-19 12:17 PM at least I can't find any records of it 24-Sep-19 12:18 PM Technically cyclotrons are RF accelerators 24-Sep-19 12:19 PM should be well within reach with a bachelors in physics and a good machine shop 24-Sep-19 12:19 PM fair enough, although I'm talking about the cavity ^^ 24-Sep-19 12:20 PM I don't know about that lol 24-Sep-19 12:20 PM I've sat in on design reviews for accelerator cavities 24-Sep-19 12:20 PM My god it's utter absurdity, at least for performance linacs 24-Sep-19 12:21 PM I'm not saying it would be easy 24-Sep-19 12:21 PM Are you talking about ion or electron? 24-Sep-19 12:21 PM electron I guess? 24-Sep-19 12:21 PM haven't thought about that 24-Sep-19 12:22 PM There is a lot more than just machining the cavity lol 24-Sep-19 12:22 PM but people are making ICs, Coldheads and pinch fusion reactors nowadays 24-Sep-19 12:22 PM Believe me, of all people out there I am a major proponent of diy accelerators lol 24-Sep-19 12:22 PM There is a reason I'm going pulsed and not rf 24-Sep-19 12:22 PM Many reasons lol 24-Sep-19 12:22 PM For fusion reactors, if you are talking about fusors thst doesn't count lol 24-Sep-19 12:22 PM The level of complexity is so many orders of magnitude different it's not even funny 24-Sep-19 12:24 PM I'm mainly looking at @qualia for that 24-Sep-19 12:24 PM oh I know regular fusors are nothing 24-Sep-19 12:24 PM http://www.rapp-instruments.de/Beschleuniger/Mikrotron/Mikrotron.htm This guy tried some RF stuff 24-Sep-19 12:25 PM Even I wouldn't attempt an RF linac lol. Not unless I was loaded or had real serious connections 24-Sep-19 12:26 PM but just some few keV have to be doable 24-Sep-19 12:26 PM i'd love to get into RF stuff eventually but i already (unfortunately) have a day job and i don't dream in multipole spherical harmonics just yet 24-Sep-19 12:26 PM That's closer to a betatron than a linac lol 24-Sep-19 12:26 PM More do able, but if you are going rf linac cavity good luck lol 24-Sep-19 12:27 PM I'm not really planning on doing that, I was just wondering 24-Sep-19 12:27 PM so many wonderful people out there 24-Sep-19 12:27 PM pinch fusion seems like its easy to do and tricky to optimize, whereas anything RF seems opaque and bizarre to even get started in 24-Sep-19 12:27 PM Yeah, there are a ton of factors 24-Sep-19 12:28 PM i got a 50W HF power amp kit i'm gonna solder together soon, first SMD project.. gonna use it to light some plasmas 24-Sep-19 12:29 PM If you want several hundred kev ebeams on the cheap, go pulsed lol 24-Sep-19 12:29 PM sweet, I've been looking for some like that, got a link? 24-Sep-19 12:29 PM sec 24-Sep-19 12:30 PM @Applied_Ion it was just a theoretical thought, as IMO the design looks doable if you only have one cavity 24-Sep-19 12:30 PM but what am I missing? 24-Sep-19 12:31 PM https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F361745212678 24-Sep-19 12:31 PM sweet, thx 24-Sep-19 12:31 PM it came with absolutely no assembly instructions and no heatsink, but that particular series of kit has a lot of clones/recs/docs on building it 24-Sep-19 12:31 PM 54W over SMA and uncooled fets? 24-Sep-19 12:31 PM @GigaSquirrel depends how you define a cavity lol 24-Sep-19 12:32 PM yeah it Needs a big heatsink 24-Sep-19 12:32 PM (sma should be fine tho? idk) 24-Sep-19 12:32 PM I'm pretty sure a few people have built DIY cyclotrons 24-Sep-19 12:32 PM @Applied_Ion Well, 30+ GHz and Superconducting of course, everything else would be just a weekend project 24-Sep-19 12:33 PM https://www.youtube.com/watch?v=1JmpU5ChaoA 24-Sep-19 12:33 PM someone on the fusor foruma definitely was working on an H-magnet for a smol cyclotron iirc 24-Sep-19 12:34 PM Oof, 30 Ghz lol. Although cavity size reduces as frequency goes up, machining tolerances skyrocket 24-Sep-19 12:34 PM Big L-band stuff have much lower tolerances than like x-band and higher linacs 24-Sep-19 12:35 PM I was kidding about the 30 GHz 24-Sep-19 12:35 PM a microwave magnetron came to mind 24-Sep-19 12:36 PM I don't think frequency stability is high enough for a microwave magnetron 24-Sep-19 12:36 PM @qualia I think it was tim koeth? He already built one before http://koethcyclotron.org/ 24-Sep-19 12:36 PM you would need a higher performance pulsed magnetron like in radar 24-Sep-19 12:36 PM yeah, I was about to mention that as well 24-Sep-19 12:36 PM furuno! 24-Sep-19 12:36 PM there's TONS of furuno magnetrons on eBay 24-Sep-19 12:36 PM Yeah, cyclotrons are definitely do-able at the amateur level 24-Sep-19 12:36 PM for home built ones, you would really struggle to get over 100keV for all of the money and effort you put into it 24-Sep-19 12:36 PM Tim Koeth's is at a university lol, the resource difference available is much higher than average DIYer 24-Sep-19 12:36 PM Like I said, I've weighed the pros and cons of each type lol 24-Sep-19 12:36 PM weight, infrastructure, power, complexity, material availability - go pulsed 24-Sep-19 12:39 PM building the magnet is a very painful part of a cyclotron or betatron build 24-Sep-19 12:39 PM thats the major cost. Not to mention how much power and cooling they require 24-Sep-19 12:39 PM if it was just a matter of building a pancake cylinder with a few copper plates, everyone and their dog would be building one :( 24-Sep-19 12:39 PM and they weigh literally about a ton 24-Sep-19 12:39 PM honestly, I don't think cyclotrons are worth the effort if you are on a budget if you want to really get serious energy or power levels for research 24-Sep-19 12:40 PM I want to find a soviet betatron tube 24-Sep-19 12:40 PM they exist and they're sometimes sold for peanuts, when they are sold 24-Sep-19 12:41 PM if you knew a good scientific glass blower, you could get one made. Still need a reasonable magnetic field for it though 24-Sep-19 12:42 PM you're overestimating the peanuts 24-Sep-19 12:42 PM I mean less than $100 for a NIB tube 24-Sep-19 12:42 PM enough to make a magnet worth its price 24-Sep-19 12:43 PM idk lol, still needs a big magnet 24-Sep-19 12:43 PM Microwave oven magnetrons can be phase locked 24-Sep-19 12:43 PM they're super noisy though 24-Sep-19 12:43 PM and very wide band 24-Sep-19 12:44 PM @rfs its not about phase locking them, its that they are too unstable in themselves. They drift a lot 24-Sep-19 12:44 PM And people have also phase locked larger units like 8kW industrial units, the germans pulled echoes of venus with that kludge. Did some DSP magic to make it re-produce linear modes. 24-Sep-19 12:44 PM there are plenty of high power pulsed radar magnetrons floating around ebay pretty cheap though 24-Sep-19 12:44 PM you really need good stability for electron linacs to work. I mean even temperature changes in the cavities will cause it to detune 24-Sep-19 12:45 PM And IIRC the spectrum cleans up a lot if you shut of the heaters after initial startup 24-Sep-19 12:45 PM at least unlocked microwave oven magnetrons stop being 15MHz wide lumps on noise. 24-Sep-19 12:45 PM That's why you phaselock it. 24-Sep-19 12:45 PM So that drift like that gets compensated 24-Sep-19 12:46 PM the microwave oven magnetrons output so much power they act like heaters unto their own 24-Sep-19 12:47 PM Yep 24-Sep-19 12:48 PM they are still not stable enough on their own. No way to adjust the output to compensate for other variations in detuning, you would need a phase shifter on the output 24-Sep-19 12:48 PM Also, about that previously linked HF PA kit, it's not super robust and not inherently stable due to the high gain. 24-Sep-19 12:48 PM It requires milliwatts of drive due to the high gain section. 24-Sep-19 12:48 PM A friend also reported that sometimes he's unit oscillates around 6MHz when connected to his 7MHz band antenna. 24-Sep-19 01:32 PM yeah i expect it to perform like garbage 24-Sep-19 01:32 PM but, hey, <$20, plus SMD soldering experience, plus probably plenty of juice for some fun RF burns 24-Sep-19 01:32 PM it's only gonna be used for 13.56 MHz in my case 24-Sep-19 01:32 PM i suspect there's like a class E topology that would work a lot better for that, but shrug 24-Sep-19 01:35 PM I might pick that up for oxygen plasma and rf sputtering experiments 24-Sep-19 01:35 PM can't imagine it'd survive long without a matching network though 24-Sep-19 01:35 PM oh yeah absolutely have a matchbox in front of it 24-Sep-19 01:35 PM plus a low pass filter 24-Sep-19 01:35 PM completely failed to grab one of the cheap MFJ versatuners the last few ham swap meets.. RIP 24-Sep-19 01:41 PM Depending on your use case, you might not need a LPF 24-Sep-19 01:42 PM I want one of those fancy auto-tuning rack mount RF power sources with a big knob to adjust them watts 24-Sep-19 01:42 PM And if the tuner you use is Pi-type inherently does some harmonic suppression. 24-Sep-19 01:42 PM @Deleted User just buy ACOM2000 with autotuner option and drive it with any 100W amateur radio with a nice knob for outputpower 24-Sep-19 01:43 PM https://i.spirit.re/87lkm.png 24-Sep-19 01:43 PM very nice, only $6600. 24-Sep-19 01:44 PM The manual units are cheaper 24-Sep-19 01:44 PM I think my tenth kidney is almost done growing 24-Sep-19 01:44 PM But it does have a widerange autotuner in it 24-Sep-19 01:44 PM and being tube based it survives missmatch MUCH better than solid state stuff 24-Sep-19 01:44 PM I'm unsure if some solid state amplifier + autotuner at +1kW would be any cheaper. All depending on what kind of powerlevels you are after. 24-Sep-19 01:46 PM I only need a maximum of maybe 150W for sputtering 24-Sep-19 01:46 PM 50W for plasma cleaning 24-Sep-19 01:46 PM what frequencies? 24-Sep-19 01:46 PM ISM to be safe from the angry party van 24-Sep-19 01:47 PM 27.21MHz whatever is used industrialy and is ISM, you can do that for under 300eur. 24-Sep-19 01:47 PM my understanding is that its amateur radio best practice to slap a LPF on any HF transmitter to keep spurious noise emission down 24-Sep-19 01:47 PM can't imagine they'd be too happy if I started pushing 150W out at 1GHz or something 24-Sep-19 01:47 PM just add in some tuner on top of that. 24-Sep-19 01:47 PM @qualia Yes, but if you are pushing everything in to a closed vessel it does not really radiate anything. 24-Sep-19 01:47 PM my vacuum chamber is all-metal so far 24-Sep-19 01:47 PM Classic industrial stuff could be +1kW free running oscillators. 24-Sep-19 01:48 PM fair 24-Sep-19 01:48 PM But yeah thinking about the potentialy radiated emissions is good practice. 24-Sep-19 01:48 PM If you have a sense of humor put some FSK-WSPR on the 13.56MHz carrer with some small shift and see if you get reports. 24-Sep-19 01:48 PM Because people do run milliwatt class 13.56MHz beacons. They call that band "HiFer" 24-Sep-19 01:50 PM just modulate an industrial 13.56 source with an FSK-WSPR signal 24-Sep-19 01:50 PM I'm sure that won't lead to any legal consequences at all 24-Sep-19 01:51 PM @Deleted User But really, you can get a 4-8W 27MHz driver for 50-150eur, a 100W amplifier for it for 50-300eur. and then spend the rest on a 12-14V PSU, fans to make the aforementioned parts actually suitable for continuous duty and then buy a 100W or 200W auto or manual tuner. 24-Sep-19 01:51 PM I'll look into it once I've recovered from the emotional and fiscal stress of spending another $250 on vacuum components to get my system running 24-Sep-19 01:52 PM the struggle is real 24-Sep-19 01:52 PM Ok 24-Sep-19 01:52 PM and probably soon to be spending $1000+ on my dream x-ray head 24-Sep-19 01:52 PM frowns loudly at her 6" 6-way CF cross >_>` 24-Sep-19 01:53 PM ABBREE AR-925 is <50eur shipped from china, KL203 (or it's clones) is between 50-70eur, but it's barely usable for continous duty. So something like KL300 might be better. Add in an LDG tuner. 24-Sep-19 01:53 PM The autotuner being the most expensive part, locally LDG Z-100 is 219eur. 25-Sep-19 12:07 AM An update on experimenting with Hositrad, the vacuum parts supplier in the Netherlands 25-Sep-19 12:07 AM DHL just informed me that there's an express shipment awaiting declaration. From them. To my email address as the company. I paid nothing. They quoted me 200 EUR for shipping alone, I replied that it's an absurd price, and have since not replied. ... free box of vacuum components, yay? 25-Sep-19 12:07 AM I will try to resolve the situation with them when I have the box, but for now I advise you refrain from dealing with the company until further notice. 25-Sep-19 12:07 AM If they sent me something without any signed agreement and expect me to pay an outrageous price for it, I'm going to be very upset. 25-Sep-19 12:48 AM So wait what? You asked for a quote and they sent you it? 25-Sep-19 01:08 AM I asked for a quote, made the order WITHOUT shipping, they sent me a quote WITH shipping(200 EUR), I replied that it's way too much. They sent me "give us your forwarding something something something", to which I still haven't replied. 25-Sep-19 01:08 AM They sent me the actual package with all the parts I ordered, but DID NOT PAY FOR. 25-Sep-19 01:08 AM and now I'm raking my brain with our customs and DHL Express, because I explicitly stated that this is a truly horrible way to send things here, because I am currently sucking up to the head customs inspector to let it through 25-Sep-19 01:08 AM oh, and I'll be paying like $90 to do it 25-Sep-19 01:10 AM :/ 25-Sep-19 01:10 AM if anything, they should be paying me now... 25-Sep-19 01:10 AM I could, of course, refuse the package and have it sent back, but who doesn't like free cheese, even if you have to step into the mousetrap to get it 25-Sep-19 01:10 AM I wrote an entire A4 page to the customs inspector explaining why this is happening 25-Sep-19 01:14 AM why do you need to explain anything to customs about some vacuum kit parts? 25-Sep-19 01:15 AM Because you have to pay customs duties on stuff you import? 25-Sep-19 01:15 AM but that sounds like a money order/check/credit card/cash, etc... not an explanation 25-Sep-19 01:16 AM excuse me what 25-Sep-19 01:16 AM How do you know how much the shipment is worth, if you never ordered it? 25-Sep-19 01:16 AM there was no swearing in that, Dyno! 25-Sep-19 01:16 AM @rfs dhl told me about the declaration 25-Sep-19 01:16 AM Ah 25-Sep-19 01:16 AM it matches the order price of 132 EUR + the absurd shipping cost of 200 EUR 25-Sep-19 01:17 AM If they insist on DHL should at least send with DDP incoterms(correctly spelled?) or something. 25-Sep-19 01:17 AM not a thing here 25-Sep-19 01:17 AM lol 25-Sep-19 01:17 AM 200eur is pretty absurd for inter-european DHL, how many kg was it? 25-Sep-19 01:17 AM DHL Express, when using it, drops it off at our customs warehouse and says "yep, go ahead, you do the declaring now, or we can do it for you for $18" 25-Sep-19 01:17 AM in the U.S., the sender seems to pay customs... I have never paid for customs for received packages in my memory (been ordering stuff online for more than 15 years) 25-Sep-19 01:18 AM it's like a kilo and a half of parts 25-Sep-19 01:18 AM 200 eur is clearly just a placeholder "we don't want to deal with you" prices 25-Sep-19 01:18 AM since dyno deleted my message, in short: 25-Sep-19 01:18 AM 1) see DHL mess above 2) it contains copious industrial parts that a normal human doesn't order 3) anything over 3 of the same thing is considered "commercial use", I've had to explain to them a few times how minimum orders on pieces worth cents each work... 25-Sep-19 01:18 AM oh, and 4) they addressed it to "Spirit" as a company 25-Sep-19 01:20 AM @nmz787 Ever ordered stuff abroad worth more than 500usd or 1500usd? I think the limit is around there for USA when they bother you about customs duties. Here the limit is 150eur for customs duties, but 22eur for VAT. 25-Sep-19 01:20 AM which just puts another nail in this coffin 25-Sep-19 01:20 AM now we wait and pray what this nice DHL lady that's handling my case will do 25-Sep-19 01:20 AM she said she's going to meet the inspector and take him to open the package for inspection 25-Sep-19 01:20 AM and now I need sleep, it's 11:20 AM 25-Sep-19 01:21 AM @rfs probably more than $500, but I think those were considered free samples... I don't really know anything about VAT other than it stands for "Value Added Tax"... I don't really understand what it's for or how/when/why it's applied 25-Sep-19 01:22 AM Goods sold have a tax in the price. 25-Sep-19 01:22 AM Goods sold outside of country don't have this tax. 25-Sep-19 01:22 AM Thus you get to pay it if importing. 25-Sep-19 01:22 AM I've ordered weird stuff though, like custom chemistry glassware from china... never got any weirdness 25-Sep-19 01:23 AM 24% for most, 16% on books/magazines and 6% or 8% on food, IIRC. 25-Sep-19 01:23 AM @rfs hmm, around here sales tax depends on the state you live in 25-Sep-19 01:23 AM we don't have sales tax where I live currently 25-Sep-19 01:24 AM Sure, I just happen to live in the State of Finland. 25-Sep-19 01:24 AM And we have all kinds of fun European style taxation. 25-Sep-19 01:24 AM That VAT thing on import is there to make it less easy for foreign companies to compete and to stop gray market importing. 25-Sep-19 01:24 AM Less of a thing nowdays with EU and the customs union. As you don't pay extra for inter-EU stuff. 25-Sep-19 01:24 AM So I mostly get to deal with VAT when ordering stuff from USA, Canada, Japan and China. 25-Sep-19 01:27 AM ah, hmm, well that helps explain things 25-Sep-19 01:27 AM @rfs do you mean these: http://www.88radio.com/RM-Italy-KL-300 https://ldgelectronics.com/index.php/products/zero-power/z-100-plus/ 25-Sep-19 01:27 AM @qualia have you seen this kit? any reviews on it? https://www.ebay.com/itm/Linear-Power-Amplifier-180W-Amp-Kits-For-Transceiver-Intercom-Radio-HF-FM-Ham/312648432909 25-Sep-19 01:27 AM seems like a better power envelope for sputtering/etc... 25-Sep-19 01:30 AM @nmz787 Yes 25-Sep-19 01:30 AM And that PA kit needs more drive. 25-Sep-19 01:30 AM The one mx.qualia linked needs much less and can be driven from a signal generator. 25-Sep-19 01:31 AM can you use them in stages? 25-Sep-19 01:31 AM the 45W kit feeding the 180W kit? 25-Sep-19 01:32 AM that "180W" one needs watts of drive 25-Sep-19 01:32 AM @rfs the KL300 seems to be higher freq than the 13.56 MHz ISM 25-Sep-19 01:33 AM Yes, it works there also, and I did refer to it in reference to 27.12MHz 25-Sep-19 01:33 AM and LDG-Z100 seems too low power (at least I thought I saw 150W target someone mentioned earlier) 25-Sep-19 01:33 AM Which is also an ISM freq used in the industry, and unsurprisingly double 13.56MHZ 25-Sep-19 01:33 AM Yea Z100 is rated for 125W, but KL203 or KL300 ain't good for above 100W constant use anyway. 25-Sep-19 01:33 AM I do have an LDG AT-200Pro myself and that's rated for 200W continuous. 25-Sep-19 01:36 AM sleeps 25-Sep-19 03:10 AM Good news! And bad news. 25-Sep-19 03:10 AM Good news is: The inspector said yes! Going to go pay the fees now. 25-Sep-19 03:10 AM Bad news is: I'm awake. I should be not awake. The eternal struggle continues. 25-Sep-19 03:17 AM I just made some coffee and can offer you one ^.^ 25-Sep-19 03:17 AM if that helps with you not wanting to be awake 25-Sep-19 03:26 AM I can wake up easily 25-Sep-19 03:26 AM sucks to fall back asleep though 25-Sep-19 03:26 AM but I guess I'll just ruin my day completely and go pick up some glassblowing things across the city as I go 25-Sep-19 03:28 AM what time is it at your place? 25-Sep-19 05:27 AM 3:26 now 25-Sep-19 05:27 AM GMT +3 25-Sep-19 08:49 AM Joined the server. 25-Sep-19 08:50 AM Welcome! 25-Sep-19 10:34 AM Joined the server. 25-Sep-19 10:35 AM Welcome! 25-Sep-19 10:35 AM Joined the server. 25-Sep-19 10:48 AM Joined the server. 25-Sep-19 10:49 AM how romantic 25-Sep-19 10:55 AM Joined the server. 25-Sep-19 11:04 AM hey, i know all those people! 25-Sep-19 11:05 AM I wonder where they all of a sudden came from 25-Sep-19 11:05 AM i have no clue. some idiot must have dropped the invite link to this server somewhere 25-Sep-19 12:28 PM Joined the server. 25-Sep-19 12:32 PM Ok where did you all get the link? Regardless welcome to the server! 25-Sep-19 12:32 PM I posted it in a discord of a famous german electronics youtuber 25-Sep-19 12:38 PM Haha 25-Sep-19 12:38 PM Very famous 25-Sep-19 12:40 PM recently surpassed 100k 25-Sep-19 12:45 PM dabs in greeting 25-Sep-19 12:45 PM @nmz787 no experience with that kit, personally, sry 25-Sep-19 12:45 PM I did only extremely cursory research into cheap rf power amps before my $17 impulse purchase :D 25-Sep-19 01:08 PM @GigaSquirrel Told me this was a great place to talk about hacking my Dyson. 25-Sep-19 01:09 PM it sure is! 25-Sep-19 01:09 PM if you want your dyson to get down to e-8 mbar, that is 25-Sep-19 02:03 PM wonder how long it'd take those bearings to burn up without any air resistance 25-Sep-19 02:03 PM get a tach on the centrifugal blower 'n let it (silently) rip 25-Sep-19 03:33 PM Joined the server. 25-Sep-19 03:34 PM yay, welcome! 25-Sep-19 10:02 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/readmsg-0D3E5.png 25-Sep-19 10:02 PM Here's what's inside a Hamamatsu microfocus tube 25-Sep-19 10:02 PM I found a seller who is willing to strike a deal with me 25-Sep-19 10:02 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/readmsg-6B1B9.png 25-Sep-19 10:02 PM It's deceivingly simple. 25-Sep-19 10:02 PM I'm getting a tube and a controller, both random and as-is, and no cable, but for a very very low price. 25-Sep-19 10:06 PM Very nice 25-Sep-19 10:06 PM All the juicy bits are potted :( 25-Sep-19 10:06 PM At least I think that's what the silver brick is 25-Sep-19 10:07 PM Looks like a bit oscillating stuff for high voltage, some stabilized lens stuff and a bunch of potting for the multiplier and filament isolation transformer? 25-Sep-19 10:08 PM I wonder if it's isolated 25-Sep-19 10:08 PM oh, it must be, duh 25-Sep-19 10:08 PM the anode is flapping in the breeze 25-Sep-19 10:08 PM focusing is clearly electrostatic, given the mini multiplier 25-Sep-19 10:08 PM in fact looks like there's two of them, one much lower voltage 25-Sep-19 10:12 PM Maybe 25-Sep-19 10:12 PM the tube looks pristine too 25-Sep-19 10:12 PM super shiny window, just a few scruffs 25-Sep-19 10:12 PM so either someone literally just tossed it out, or I'm paying money for a very pretty brick with a flat filament or unhappy transformer/multiplier. 25-Sep-19 10:14 PM I may be able to pick up a Hitachi S 450 SEM next month, there are transport issues though. I don't have access to a garage, so it may have to squeeze through some doorways or even go up/down a few steps of stairs. 25-Sep-19 10:14 PM I'd like to evaluate my options. How feasible is it to transport a SEM column with stage attached when the diffusion pump and baffle is detached from it? Should I be really concerned about messing up alignment and so on? 25-Sep-19 10:15 PM Got photos of it? 25-Sep-19 10:16 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/s-l1600-A265D.png 25-Sep-19 10:16 PM oh, it's that one! 25-Sep-19 10:16 PM For $250 it's worth it for me to go and get it 25-Sep-19 10:16 PM As you can see it is bolted down to an aluminum plate, the baffle is right under that thing, may be possible to just undo the bolts and lift the stage and column out. 25-Sep-19 10:18 PM Yeah it's doable 25-Sep-19 10:18 PM But the frame is the frame 25-Sep-19 10:18 PM So are you just hoping to get weight down? 25-Sep-19 10:19 PM Yeah, and the height down 25-Sep-19 10:19 PM The frame is pretty empty if I take out the diff pump, baffle and its cooling 25-Sep-19 10:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/s-l1600-65A30.png 25-Sep-19 10:21 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20170226_141638-6EBAD.jpg 25-Sep-19 10:21 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20170226_143633-2EDF0.jpg 25-Sep-19 10:21 PM That's essentially what I aim to do yeah 25-Sep-19 10:21 PM Have to take apart the power supply, but I hope to leave the console in one piece 25-Sep-19 10:22 PM You need to teach classes on how to become a SEM magnet 25-Sep-19 10:22 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_-ptzuub-CACF2.jpg 25-Sep-19 10:22 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20170227_080352-58E78.jpg 25-Sep-19 10:22 PM So this is how my first sem came 25-Sep-19 10:22 PM I want to just walk into a university and have a SEM handed to me for free 25-Sep-19 10:22 PM Preferably a tiny desktop one, like a mochii 25-Sep-19 10:22 PM Lol I think my university just tossed out a SEM last winter 25-Sep-19 10:22 PM It was not working though, seemed to be in rough condition 25-Sep-19 10:23 PM Not taking it for scrap value is a sin 25-Sep-19 10:23 PM I didn't get on the "excess inventory" email list at that time 25-Sep-19 10:24 PM Hopefully you're on it now 25-Sep-19 10:24 PM Yeah, but all the good stuff usually gets snatched by professors first 25-Sep-19 10:24 PM Yeah a lot of SEMs meet that fate 25-Sep-19 10:24 PM But yeah it's definitely possible to take a scope apart like that 25-Sep-19 10:25 PM Any concerns with transporting the column on its side? 25-Sep-19 10:25 PM Yeah 25-Sep-19 10:25 PM Mostly the gun 25-Sep-19 10:25 PM Take the photo multiplier off for sure 25-Sep-19 10:26 PM So take the gun off if possible too? 25-Sep-19 10:26 PM I wouldn't like try to carry the chamber on one end and the column on the other 25-Sep-19 10:26 PM That would be a really bad idea 25-Sep-19 10:27 PM Okay, I need to see if they can be separated for this particular SEM 25-Sep-19 10:27 PM So I don't see how else to carry the column 25-Sep-19 10:27 PM Why can't it just stay vertical? 25-Sep-19 10:27 PM Definitely advoide seperating the column from the chamber as well 25-Sep-19 10:27 PM The gun is just hinged is why it is a problem 25-Sep-19 10:27 PM All those column bolts work with the help of gravity 25-Sep-19 10:29 PM I will try my best to provide space for the column to stay vertical during transport, but space is tight with the vehicle I will be using 25-Sep-19 10:29 PM I am so poor that I can't even afford a Uhaul... 25-Sep-19 10:30 PM Yeah definitely do not transport on its side 25-Sep-19 10:30 PM That would probably destroy it 25-Sep-19 10:30 PM If it gets warped at all your done 25-Sep-19 10:30 PM The outside of the column is also part of the magnetic lens in some cases 25-Sep-19 10:31 PM Okay thanks for the advice, time to ask for detailed measurements to make sure it will stay upright and in one piece during transport 25-Sep-19 10:31 PM Seperating from the base is fine 25-Sep-19 10:31 PM If you do absolutely need to, go ahead and take column off chamber 25-Sep-19 10:31 PM Be very very very careful as the poll piece will be exposed 25-Sep-19 10:31 PM If that gets scratched your also done 25-Sep-19 10:31 PM Be sure to pull it off as one piece if you don't know where the column liner is 25-Sep-19 10:34 PM Okay, if I get an opportunity to put it in a trailer or a larger van I will do so to avoid any more disassembly than necessary 25-Sep-19 10:34 PM Yeah that's preferred 25-Sep-19 10:34 PM Though a trailer can be rough 25-Sep-19 10:34 PM Another thing with this SEM is that some traces on the console control boards are cut to accomodate for digital beam control. There's apparently just a DB25 connector going out 25-Sep-19 10:35 PM un-cut them! :P 25-Sep-19 10:35 PM Yeah just jumer everything and it should be fine 25-Sep-19 10:35 PM But 25-Sep-19 10:35 PM Having those is nice 25-Sep-19 10:35 PM Yeah that's my plan, but DBC would be nice... 25-Sep-19 10:35 PM It's best to build a jumper to plug into the db25 port 25-Sep-19 10:35 PM That's pretty much how my ISI runs 25-Sep-19 10:35 PM Also keep the oil tank upright 25-Sep-19 10:35 PM If it has one 25-Sep-19 10:35 PM S450 is a good beginer sem 25-Sep-19 10:40 PM It's still going to be by far the largest thing I've moved though... And I will be moving quite often in the future I think. But can't turn it down with that price 25-Sep-19 10:40 PM Yeah the 450 is bigger than the isi I showed 26-Sep-19 01:03 AM hm such an ISI was my first SEM ^^ 26-Sep-19 01:05 AM hey @AdamMcCombs your SEM gun is way different from what Ben made on this DIY SEM ? 26-Sep-19 02:19 AM @Mason_Yu if you need to use a trailer, try to get one with an air suspension, it will reduce the shock a lot 26-Sep-19 02:19 AM @Mason_Yu this is the one I rented to bring home my FIB, and it seems to work without any obvious mechanical issues https://www.portlandrentall.com/equipment.asp?action=category&category=5&key=13225%2D2 26-Sep-19 02:19 AM @Vini's Lab depends on which SEM you're talking about, he has both thermal and field emission guns 26-Sep-19 02:46 AM Joined the server. 26-Sep-19 02:59 AM my first ISI i cleaned ^^ 26-Sep-19 02:59 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/pekoskop2-1483A.jpg 26-Sep-19 02:59 AM @AdamMcCombs %) 26-Sep-19 03:07 AM Beautiful 26-Sep-19 03:08 AM hi Nixie 26-Sep-19 03:22 AM Hellooo 26-Sep-19 04:08 AM it's i dunno 2 1/2 years ago and of course i put it together again 26-Sep-19 04:08 AM just sayin 26-Sep-19 04:42 AM Hello everyone 26-Sep-19 04:42 AM I have a outgassing question 26-Sep-19 04:42 AM Outgassing is forever or just the first minutes? 26-Sep-19 04:42 AM For example for silicone adhesive 26-Sep-19 04:44 AM forever 26-Sep-19 04:45 AM depends the material, some resins start to decompose in vacuum , silicone is better but even them, if you wanna a permanent solution you need to go to metal seals 26-Sep-19 04:46 AM I'm making a vacuum chamber, and welding heat distort the metal 26-Sep-19 04:46 AM So I m thinking to seal the walls using silicone adhesive 26-Sep-19 04:46 AM use metal seals 26-Sep-19 04:46 AM not a good idea 26-Sep-19 04:46 AM never will be what we call a "vacuum chamber" 26-Sep-19 04:46 AM if the weld is bad, try again 26-Sep-19 04:46 AM till it's good 26-Sep-19 04:48 AM I cant handle the distortion of the metal sheet with the heat 26-Sep-19 04:48 AM maybe you are using to thin sheets 26-Sep-19 04:48 AM with tig and thick enough sheets you should be able to weld 26-Sep-19 04:49 AM question is, what kind of vacuum do you expect 26-Sep-19 04:49 AM I'm tig welding 5-10mm metal sheets 26-Sep-19 04:49 AM which chamber size? 26-Sep-19 04:49 AM i think is better if you send pictures 26-Sep-19 04:49 AM thing is proper TIG welding is not that easy and needs alot of practice 26-Sep-19 04:49 AM especially if you're trying to build vacuum stuff 26-Sep-19 04:50 AM 10^-2 to 10^-4 pascal 26-Sep-19 04:50 AM size not pressure 26-Sep-19 04:53 AM i would recommend throwing the part away and try again til it's good enough 26-Sep-19 04:53 AM for vacuum stuff there is no "grinder and paint makes you ..." 26-Sep-19 04:55 AM Okay. I will try again. I need to think how to handle the distortion 26-Sep-19 04:56 AM yep 26-Sep-19 04:56 AM that's the art of welding, i guess ^^ 26-Sep-19 05:58 AM There is viton rubber too. 26-Sep-19 05:58 AM It would be interesting to see the actual piece and the amount of warpage. 26-Sep-19 06:23 AM yeah, wrapping the whole thing in viton ^^ 26-Sep-19 06:23 AM or a chamber made of viton with a steel endoskeleton 26-Sep-19 06:25 AM Rofl 26-Sep-19 06:25 AM Holes would need to be small for the rubber to hold, and then you would have virtual leaks all over the place from air pockets. 26-Sep-19 08:35 AM This is why I tend to braze vacuum components. Regular tig techniques add too much heat. In brazing you can bring the temp up on the whole piece more easily then go in and make the joint. 26-Sep-19 08:40 AM I would need to see the pieces, but with TIG you can just spot weld the perimeter to make everything stay in place, then weld short bits at a time. If anything, the body should be thin and the flanges thick, so if something has to "give" it will be the body, leaving the sealing surfaces in good shape. Also TIG allows very clean fill of big gaps, not sure brazing will be as easier. 26-Sep-19 08:40 AM (but each technique has it's pros and cons, not arguing against brazing at all!) 26-Sep-19 10:10 AM Does brazing prevent best vacuum relative to Tig? 26-Sep-19 10:16 AM @Vini's Lab yeah my new SEM definitely is. Field emmison and especially cold field emmison is a massive step up in resolution compared to Thermionic. 26-Sep-19 10:29 AM Thanks 26-Sep-19 10:29 AM @AdamMcCombs do you u know manufacturers prefer electromagnetic than electrostatic lenses only by the factor it has less chromatic aberrations or there's any other reason? 26-Sep-19 10:40 AM Electromagnetic definitely wins out in chromatic 26-Sep-19 10:40 AM There are some hybrid systems out there that are ultra high resolution 26-Sep-19 10:40 AM But they are levraging static in unique ways 26-Sep-19 10:42 AM I wonder if there's a way to get rid of chromatic aberrations with electrostatic 26-Sep-19 10:43 AM Kinda 26-Sep-19 10:43 AM Some sort of monochromator 26-Sep-19 10:43 AM trade current for image 26-Sep-19 10:44 AM Monochromator doesn't fix cs 26-Sep-19 10:44 AM Oh wait I see what you are asking now 26-Sep-19 10:44 AM I miss spoke, magnetic wins out in spherical aberation 26-Sep-19 10:44 AM Chromatic is dependent on the electron gun 26-Sep-19 10:47 AM Ah, I see 26-Sep-19 10:47 AM I have the vacuum parts that Hositrad sent to me as an accidental gift 26-Sep-19 10:47 AM So I can finally start assembling 26-Sep-19 10:47 AM I think I'll make the SEM column out of the same KF50 size flanges 26-Sep-19 10:48 AM accidental gift: 26-Sep-19 10:48 AM you build your SEM from scratch? 26-Sep-19 10:48 AM ok, nice 26-Sep-19 10:48 AM can't afford one 26-Sep-19 10:48 AM ah 26-Sep-19 10:48 AM so I'll spend the same amount of money on building my own o\ 26-Sep-19 10:49 AM D= 26-Sep-19 10:49 AM with a better chance never completing it! 26-Sep-19 10:49 AM but the learn is higher, i guess 26-Sep-19 10:57 AM Don't be so negative, @N00N , with the knowledge and help from here, he certainly has possibilities. 26-Sep-19 10:59 AM Well, technically, everyone has a chance of success 26-Sep-19 10:59 AM it's just usually a very low fractional number :P 26-Sep-19 11:00 AM wasnt meant so negative 26-Sep-19 11:00 AM i mean of course he can do! 26-Sep-19 11:05 AM Xd, OK 26-Sep-19 11:05 AM Well, I expect your success nonetheless. 26-Sep-19 12:53 PM https://i.spirit.re/Ki4yk.jpg 26-Sep-19 12:53 PM It's finally coming together! 26-Sep-19 12:53 PM Though I'm still missing a few pieces because I'm dumb. 26-Sep-19 12:55 PM Just woke up from a nap i took with my toddler... Had a pretty bad dream... Came home to neighbors in my house preparing for some neighborhood party... Saw junk in my backyard rearranged and was slightly thrown off, but then went into my garage and saw more party stuff... And then noticed my FIB had been moved and the cables seemed disconnected too!!!! 26-Sep-19 12:56 PM Your neighbors, in your house, preparing for a party? 26-Sep-19 12:56 PM Ended up trying to clear space to get things back together, loaded excess garage junk into my truck to take to my shed, which somehow was no longer in my backyard but a drive, and when i got to the storage shed I found the cap on my pickup truck was loose and the bolts holding it on had broken and subsequently scratched my truck's paint a lot 26-Sep-19 12:57 PM Also how in the hell do your neighbors move an entire FIB while you were asleep 26-Sep-19 12:57 PM Right??!?! 26-Sep-19 12:57 PM check for missing pieces 26-Sep-19 12:57 PM if I were you I'd call the police lol 26-Sep-19 12:57 PM To be fair the pallet jack is still under my fib 26-Sep-19 12:58 PM I'm also confused by how your neighbors are just casually in your house 26-Sep-19 12:58 PM It was a dream! 26-Sep-19 12:58 PM oh 26-Sep-19 12:58 PM Err, nightmare! 26-Sep-19 12:58 PM I'm really tempted to suck the vacuum system down now 26-Sep-19 12:58 PM but the only way I can do that is by plugging the purge/vent port with a kf16 cap 26-Sep-19 12:58 PM at which point.... I will have no way to vent the system, at all 26-Sep-19 12:58 PM aside from explosive venting which will probably destroy the ion gauge and turbo blades 26-Sep-19 01:03 PM Yeah, don't chance it 26-Sep-19 01:03 PM It probably could leak slowly back to normal pressure, but it could take weeks or months depending on how well you did your job 26-Sep-19 01:03 PM I waited 2 years to power up my fully functional FIB from the time I brought it home 26-Sep-19 01:03 PM Just because I was scared to break it 26-Sep-19 01:17 PM Anyone here who knows their stuff when it comes to ludlum meters? 26-Sep-19 01:17 PM I got a Model 12 from '74, according to some internal datecodes 26-Sep-19 01:17 PM but it's a bit weird 26-Sep-19 01:17 PM doesn't have a HV test button and no HV on the dial 26-Sep-19 01:17 PM and it won't go above 1.6 kV, which bothers me the most 26-Sep-19 01:17 PM I'm not sure if it's broken or of the old ones just didn't go as high 26-Sep-19 01:40 PM isn't 1.6 a fairly typical limit? 26-Sep-19 01:41 PM it would be, but all the documents I can find on model 12s mention 2.5 26-Sep-19 01:41 PM and the poti for setting voltage is only half way to two thirds at 1.6 kV, turning it further doesn't change anything 26-Sep-19 01:43 PM i think you should open and check the resistors 26-Sep-19 01:43 PM big chance you have a resistor way over the specs 26-Sep-19 01:43 PM I opened it, and everything looks fine at first glance 26-Sep-19 01:43 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190926_171320-6C01E.jpg 26-Sep-19 01:43 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190926_171350-7ACF6.jpg 26-Sep-19 01:45 PM voltage rails? 26-Sep-19 01:45 PM please change the caps 26-Sep-19 01:47 PM they're all fine 26-Sep-19 01:48 PM the pot is fine? 26-Sep-19 01:48 PM the oscillator just tops out at 1.6 kV 26-Sep-19 01:48 PM yep 26-Sep-19 02:33 PM Joined the server. 26-Sep-19 02:34 PM yay, Welcome! 26-Sep-19 02:36 PM Aloha 26-Sep-19 02:41 PM Anyone have a nice printable poster with number lines and scales fot torr, pascal, mbar, etc??? Something I can hang up in the lab. 26-Sep-19 02:52 PM Pfeiffer has some nice Posters for free 26-Sep-19 02:57 PM how does one pronounce 'Pfeiffer' 26-Sep-19 02:57 PM I just start with 'P' and continue with an arbitrary number of ff's and letters 26-Sep-19 02:57 PM xD 26-Sep-19 02:58 PM https://www.youtube.com/watch?v=h19YjALZQ_g 26-Sep-19 02:58 PM I am thinking if there is any english word with some similar pronounciation 26-Sep-19 02:58 PM nope 26-Sep-19 03:02 PM Pifffufffler 26-Sep-19 03:03 PM not even close xD 26-Sep-19 03:03 PM I know 26-Sep-19 03:03 PM feif-er 26-Sep-19 03:04 PM that, but with a P infront 26-Sep-19 03:04 PM you don't pronounce the P 26-Sep-19 03:04 PM yes you do 26-Sep-19 03:04 PM FIF-ER 26-Sep-19 03:04 PM PFEIFFER 26-Sep-19 03:04 PM xD 26-Sep-19 03:05 PM P is silent 26-Sep-19 03:05 PM just need a good aim 26-Sep-19 03:05 PM god damn it 26-Sep-19 03:05 PM xD 26-Sep-19 03:06 PM but still 26-Sep-19 03:06 PM Pfeiffer 26-Sep-19 08:36 PM Morning! 26-Sep-19 11:48 PM Someone just helped me buy this 26-Sep-19 11:48 PM https://www.hamamatsu.com/eu/en/product/type/L9181-05/index.html 26-Sep-19 11:48 PM The seller says it's in fully functional condition and tested by "our technician".... 26-Sep-19 11:48 PM now I need to make hamamatsu happy and have them send the datasheet over 27-Sep-19 12:04 AM Nice 27-Sep-19 12:04 AM that should be a lot of fun 27-Sep-19 12:16 AM awww 27-Sep-19 12:37 AM Tomorrow I have to go pick up the viton o-rings I found locally 27-Sep-19 12:37 AM Because I don't like how the eBay KF16 vent valves are made, and I want to make my own smooth/slow vent valve 27-Sep-19 12:37 AM And then I can try sucking my system down for the first time! And being disappointed in how badly it performs, probably, since I didn't clean the turbo at all, and it's super dirty. 27-Sep-19 12:45 AM you could use a HEPA filter to vent your system with clean air 27-Sep-19 12:46 AM the air is plenty clean 27-Sep-19 12:46 AM I need a vent valve that doesn't just rip the flange open and blast the chamber with air 27-Sep-19 12:46 AM so I'm going to make my own 27-Sep-19 12:47 AM yes but i mean regarding the turbo dirtiness 27-Sep-19 12:47 AM it's already dirty 27-Sep-19 12:47 AM oily and dirty 27-Sep-19 12:47 AM came this way 27-Sep-19 12:47 AM well so you need to clean first hehe 27-Sep-19 12:47 AM only if I can get it to work properly first 27-Sep-19 12:47 AM I don't want to disassemble it to find out I've destroyed some sacred holy balancing alignment of the ancient mayans 27-Sep-19 12:48 AM uheuhehue, it's not so critical 27-Sep-19 12:48 AM you cant bend the blades for sure 27-Sep-19 12:48 AM it's a 90krpm turbo 27-Sep-19 12:48 AM i know 27-Sep-19 12:48 AM there is videos on youtube showing the disassembly 27-Sep-19 12:49 AM showing the disassembly of some random old turbo 27-Sep-19 12:49 AM that is not mine 27-Sep-19 12:49 AM well the working principle is the same 27-Sep-19 12:50 AM a truck engine and building-sized LNG tanker engine have the same working principle 27-Sep-19 12:50 AM hehehe 27-Sep-19 12:50 AM use soap and water so 27-Sep-19 12:52 AM that'll outgas like hell 27-Sep-19 12:52 AM I have pure acetone and ethanol 27-Sep-19 12:52 AM works too 27-Sep-19 12:52 AM but you need a lot 27-Sep-19 12:52 AM if I give it a bath, yeah 27-Sep-19 12:52 AM but I'd prefer to avoid that 27-Sep-19 12:53 AM you can start with water after with ethanol and finishing with acetone 27-Sep-19 12:53 AM I'll start with getting the controller for it running 27-Sep-19 12:54 AM oh okay so you dont know if the turbo works yet? 27-Sep-19 12:54 AM I've only spun it up to 3krpm in air 27-Sep-19 12:54 AM still need to iron out the kinks in my prototype controller and build a proper one 27-Sep-19 12:55 AM yeah 27-Sep-19 12:55 AM well if spins smooth without weird noises big chance is working good 27-Sep-19 12:55 AM these only spin smooth without weird noises at vacuum-only speeds 27-Sep-19 12:55 AM the bearings sound gnarly until you start getting it up to speed 27-Sep-19 12:56 AM well more weird than normally i mean hehe 27-Sep-19 12:56 AM anyway biggest problem that you can have is to have to replace the bearings 27-Sep-19 12:57 AM I'm well aware 27-Sep-19 06:23 AM gee wow 27-Sep-19 06:23 AM ludlum being friendly and helpful as usual 27-Sep-19 06:23 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-BD809.png 27-Sep-19 06:30 AM Hehe 27-Sep-19 06:30 AM Was worth a try 27-Sep-19 06:34 AM was it? 27-Sep-19 06:34 AM I hope I have better luck with my RGA... 27-Sep-19 06:34 AM @Pan Da wanna try the same but from your address? Maybe they just dislike me for some reason 27-Sep-19 09:13 AM UK Peeps: https://vacuum-expo.com/ 27-Sep-19 10:58 AM Left the FIB at 4am, now 7 hours later, let's go see if my garage is on fire or my turbo crashed (i always think of scary situations) 27-Sep-19 10:58 AM (I left it on, pumping down) 27-Sep-19 11:00 AM watch the vacuum meter say 1*10^-3 mbar 27-Sep-19 11:47 AM ok wth 27-Sep-19 11:47 AM my ludlum has a tunnel diode inside 27-Sep-19 11:47 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/17_closer-63FEF.jpg 27-Sep-19 11:47 AM CR3, below the left rotary switch 27-Sep-19 12:49 PM Anyone happen to have a good list of oring sizes for standard KF? Chart or table or something? I have a ton of KF centering rings with bad orings on them. Centering rings are fine though. But I rarely seen standard vacuum supply companies just selling orings without centering rings. I assume I can just order them from standard oring supply companies but don't know what the sizes are. 27-Sep-19 01:04 PM I got viton o-rings from aliexpress and ebay, just stating the KF size. 27-Sep-19 01:06 PM @Conmega https://www.marcorubber.com/o-ring-kf-centering-rings.htm 27-Sep-19 01:06 PM and yeah, you can order them in bags from eBay 27-Sep-19 01:06 PM the seller "connekt" is reputable, I bought from them 27-Sep-19 01:06 PM https://www.ebay.com/sch/m.html?_odkw=kf+flange&_ssn=connekt&_armrs=1&_osacat=0&_from=R40&_trksid=m570.l1313&_nkw=kf+viton&_sacat=0 27-Sep-19 01:12 PM I was hoping to get sizes for https://www.globaloring.com so I could buy from them. They are SUPER cheap lol I guess because they practically have the market on orings lol. 27-Sep-19 01:12 PM Ah cool that first link has all the info I need I think 27-Sep-19 01:12 PM you can just buy "FKM" since viton is only the trademark name 27-Sep-19 01:13 PM But yea I highly reccomend global oring, so does Adam 27-Sep-19 01:13 PM FKM and FKP are also the same thing 27-Sep-19 01:13 PM cool, never even heard those acronyms? before 27-Sep-19 01:13 PM it's the family of fluoroelastomers 27-Sep-19 01:13 PM FKM is ASTM international standard, FPM is ISO/DIN 1629 27-Sep-19 01:13 PM they're all the same 27-Sep-19 01:15 PM @DUIofPhysics I reccomend for a turbo, if you can find any similar model's controller from the same company of larger capacity you can generally hook it up and make it work. Thats what I did for my Turbo-V70. 27-Sep-19 01:15 PM there's a chart for the older pfeiffer turbos 27-Sep-19 01:15 PM that shows which controller works with what turbo 27-Sep-19 01:15 PM I got like a Turbo-V200? Controller or something for cheap and hooked it up... Same exact type of motor. It just ran at a slower speed so I just had to change one resistor in it to get the speed within range then trim it with the scope. 27-Sep-19 01:15 PM Right but we are talking about doing it on the cheap. 27-Sep-19 01:16 PM the chart is for older controllers :P 27-Sep-19 01:16 PM newer controllers don't work with any of them lol 27-Sep-19 01:16 PM If the turbos are common the controllers are generally expensive. If the controllers are common and cheap the turbos are impossible to find. 27-Sep-19 01:16 PM So generally hacking the two together works great for the money. 27-Sep-19 01:16 PM but for doing it on the cheap, nothing beats a pair of fets+drivers for $5 in total 27-Sep-19 01:16 PM driving 2 and 4 phase turbos is stuuuuuuupid easy 27-Sep-19 01:16 PM 3 phase is also easy and very cheap if you have a motor that runs under ~20-24V 27-Sep-19 01:17 PM Eh if you want to futz with that. Its a lot of effort and generally the proper controllers have a lot of safety interlocks, spin up/down features and stuff you won't get without months of development on your own driver board. 27-Sep-19 01:17 PM The problem is a lot of these are like 48V 27-Sep-19 01:17 PM at-least from what I've seen 27-Sep-19 01:17 PM there's very little in terms of effort and especially safety 27-Sep-19 01:17 PM surprisingly little actually 27-Sep-19 01:17 PM my controller will probably have a few safeguards in terms of load detection 27-Sep-19 01:17 PM temperature is a painful bit, since almost no single turbo has the same temperature sensor or margins 27-Sep-19 01:17 PM I've also found that a lot of turbo controllers(older ones of course, the ones we can afford) take the extreme brute force approach to getting the turbos up to speed, pushing many amps through the motor at the start 27-Sep-19 01:21 PM Well if you want to build your own controller you can but I think some people here are not inclined to and just want to have a working turbo I think. 27-Sep-19 01:21 PM And yes there is the different value thermistor to deal with 27-Sep-19 01:21 PM but thats not a big deal to reverse engineer that little circuit and change some values to make it within range. 27-Sep-19 01:22 PM an acquaintance of mine requested I make a batch of controllers for his lonely pfeiffer turbos 27-Sep-19 01:22 PM so I think I'll just order a larger batch and offer a few as DIY kits 27-Sep-19 01:22 PM but they'll be open source and very simple to build, so anyone with a bit of soldering skills could do it 27-Sep-19 01:22 PM I haven't figured out what I want to do for 3-phase turbos though, they're a massive pain 27-Sep-19 01:27 PM Why 3 phase turbos can',t use rc brushless drivers? 27-Sep-19 01:27 PM if they're low voltage, you can! 27-Sep-19 01:27 PM but because of the speeds they run at, most turbos require at least 24 volts to get up to speed, sometimes above 48 27-Sep-19 01:27 PM and most RC brushless drivers have very low voltage, high current fets 27-Sep-19 01:28 PM The newer 150w/300w drivers do operate at such high voltages 27-Sep-19 01:28 PM even older ones 27-Sep-19 01:28 PM leybolds, agilents, edwards 27-Sep-19 01:28 PM 10S bateries of 35V are common now. 27-Sep-19 01:28 PM 10S controllers are very much not 27-Sep-19 01:28 PM the only exception is hoverboard-style motor controllers, but they're huge and not rated for these speeds or amounts of back-emf 27-Sep-19 01:28 PM so the turbo controller board will have a section for 2 and 4-phase drivers(they're the same electrically, one just doubles up the fets) 27-Sep-19 01:30 PM https://hobbyking.com/en_us/turnigy-monster-2000-200a-4-12s-brushless-esc.html?___store=en_us 27-Sep-19 01:30 PM look at how stupid the price is 27-Sep-19 01:31 PM Up to 12S, 180 euro 27-Sep-19 01:31 PM and it has no current limit 27-Sep-19 01:31 PM it'll push the full current at full voltage at all times 27-Sep-19 01:31 PM which will destroy the motor 27-Sep-19 01:31 PM Aha, that's what I was asking. 27-Sep-19 01:31 PM So it's not just driving it, but doing so carefully. 27-Sep-19 01:32 PM you have to drive it in CC-CV mode 27-Sep-19 01:32 PM sort of like battery charging 27-Sep-19 01:32 PM at full speed the motor won't take much current due to back-emf 27-Sep-19 01:33 PM I wonerif the firmware could be rewritten to some extent to not destroy the motor 27-Sep-19 01:33 PM it probably can, yeah 27-Sep-19 01:33 PM NOT that I'm going to look into it. 27-Sep-19 01:34 PM but most of these ESCs use tiny microcontrollers and run very optimized assembler code 27-Sep-19 01:34 PM the amount of effort the developers put into making these perform the best for the lowest price is astonishing 27-Sep-19 01:34 PM Yeah. 27-Sep-19 01:34 PM I am lucky that my turbo has driver, crippled, but working. 27-Sep-19 01:34 PM my controller won't be doing constant-current control per se 27-Sep-19 01:34 PM I'll be using PWM to drop the average current 27-Sep-19 01:35 PM How much do you expect the kits to go for? 27-Sep-19 01:35 PM no idea 27-Sep-19 01:35 PM very likely under $50 if it's just a bag of parts and a PCB 27-Sep-19 01:35 PM the kits won't include a mains supply though 27-Sep-19 01:38 PM Sounds interesting, will you put them on Tindie? 27-Sep-19 01:38 PM probably not 27-Sep-19 01:42 PM Ok. 27-Sep-19 01:51 PM I think the conversation has basically finished in #resources 27-Sep-19 02:10 PM @spirit just a little lower pressure 27-Sep-19 02:10 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190927_140915-994C3.jpg 27-Sep-19 02:11 PM that smells like a leak 27-Sep-19 02:11 PM -4 in 7 hours seems like air is screaming in 27-Sep-19 02:13 PM Been around 10 hours now 27-Sep-19 02:13 PM what's tmp2 for? 27-Sep-19 02:13 PM load lock? 27-Sep-19 02:13 PM The top section is IGP and according to specs is doing great 27-Sep-19 02:13 PM Yeah load lock 27-Sep-19 02:14 PM IGP should get sucked down by tmp1 27-Sep-19 02:14 PM Specs say chamber should achieve 8*10-5 or lower 27-Sep-19 02:14 PM The bypass is only open during startup 27-Sep-19 02:15 PM try closing the load lock valve 27-Sep-19 02:15 PM see if it goes down faster 27-Sep-19 02:15 PM And v1 between column and chamber is closed 27-Sep-19 02:15 PM Load lock has been closed 10 hrs 27-Sep-19 02:15 PM Thats indicated by the solid green vertical bar 27-Sep-19 02:15 PM odd 27-Sep-19 02:15 PM Maybe load lock door is leaking? 27-Sep-19 02:16 PM is the load lock turbo working? 27-Sep-19 02:17 PM Yeah 27-Sep-19 02:17 PM This is pascall not torr 27-Sep-19 02:17 PM oh, that's right 27-Sep-19 02:17 PM torr to pascal is very different to torr to mbar 27-Sep-19 02:17 PM in that case it's very good 27-Sep-19 02:18 PM 2.4x-6 torr is not bad 27-Sep-19 02:18 PM yeah 27-Sep-19 02:18 PM Yeah especially for a chamber this massive 27-Sep-19 02:18 PM It's probably min 24 hours probably more to get to spec base pressure 27-Sep-19 02:21 PM Box of gloves for scale 27-Sep-19 02:21 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190927_142042-1B9A0.jpg 27-Sep-19 02:21 PM you're one lucky guy 27-Sep-19 02:21 PM and that is a gigantic chamber 27-Sep-19 02:21 PM Chamber continues down for another two boxes of gloves worth 27-Sep-19 02:22 PM this is a couple thousand dollars in pure stainless alone 27-Sep-19 02:22 PM and probably a couple hundred in gold lol 27-Sep-19 02:23 PM Big turbo too 27-Sep-19 02:23 PM no turbo in that picture though 27-Sep-19 02:23 PM I have a photo of it but it's over 8mb 27-Sep-19 02:24 PM you're probably the only person in the world who also does scanning electron tourism 27-Sep-19 02:24 PM That is worth a few thousand in stainless?!? 27-Sep-19 02:24 PM yes 27-Sep-19 02:24 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190927_142419-4A4E8.jpg 27-Sep-19 02:25 PM https://www.ebay.co.uk/itm/HV-Vacuum-Chamber-GATE-VALVE-TURBO-PUMP-DIFFUSION-PUMP-ROTARY-PUMPS/233351148542?hash=item3654cff3fe%3Ag%3A3U8AAOSwJQZdi0--&LH_ItemCondition=4 27-Sep-19 02:25 PM so this would be worth a buy in scrap metal alone? xD 27-Sep-19 02:25 PM yes. 27-Sep-19 02:25 PM one hell of a diffusion pump below... 27-Sep-19 02:25 PM for 1500 it's basically free 27-Sep-19 02:25 PM it has a gigantic turbo too 27-Sep-19 02:25 PM holycrap, that turbo pump 27-Sep-19 02:25 PM yeah o.o 27-Sep-19 02:25 PM 1380l/s 27-Sep-19 02:25 PM It's not as much tourism as it's my job... 27-Sep-19 02:26 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190927_142538-FEE7A.jpg 27-Sep-19 02:26 PM your job acquisition story is always funny to me 27-Sep-19 02:26 PM you wanted a SEM, you got a SEM, now you work with them 27-Sep-19 02:26 PM now that I think about it, my job with industrial robots happened exactly the same way.... 27-Sep-19 02:26 PM Funny enough I do more TEM work 27-Sep-19 02:26 PM But yeah same thing 27-Sep-19 02:36 PM hello hello 27-Sep-19 02:36 PM settled on a deal for some of those watchmaking machinery, and it is in Columbus, so it will await my arrival uponc ompleting school 27-Sep-19 02:36 PM funny thing there is, the person who got it/sold it to me makes machines with another guy I took a class with, who co-teaches it with a lady here that I may intern with - that catalog'd and sold the machine from a a watchmakers estate like 5 years ago 27-Sep-19 02:36 PM so.. 5 machines in Ohio awaiting me 27-Sep-19 02:46 PM A new version of gear acquisition syndrome 27-Sep-19 02:46 PM Remote GAS 27-Sep-19 02:46 PM You buy the gear, but you don't get it. 27-Sep-19 02:46 PM I uh think I might want to put new back up batteries in my turbo controller. 27-Sep-19 02:46 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190923_031303-9780A.jpg 27-Sep-19 02:46 PM It says it's new! 27-Sep-19 02:46 PM /s 27-Sep-19 02:46 PM that is a huge turbo controller, is it maglev? 27-Sep-19 02:47 PM Yup 27-Sep-19 02:47 PM there's so many maglev turbos showing up cheap now 27-Sep-19 02:47 PM but I'm too hesitant to get one 27-Sep-19 02:47 PM 4 main machines left on the list.. a press (maybe hydraulic given the relatively small quantities, so speed wont really be needed).. a four-slide 'press' for forming springs, and an automatic-cam lathe with the machine to make the cams 27-Sep-19 02:48 PM I wouldn't have mag lev if I didn't need it 27-Sep-19 02:48 PM SEM vibrations \o/ 27-Sep-19 02:48 PM Yup 27-Sep-19 02:48 PM 2/3/4ph drive turbos are at least a little documented 27-Sep-19 02:48 PM but maglev is voodoo 27-Sep-19 02:48 PM You have that right 27-Sep-19 02:49 PM have you ever seen a molecular drag vacuum gauge in person? 27-Sep-19 02:49 PM I've seen them described, but I have a feeling there's like 3.5 in the world and they're all in super duper labs 27-Sep-19 02:50 PM Well kinda 27-Sep-19 02:50 PM But not the fancy one your thinking of 27-Sep-19 02:50 PM there are non-fancy molecular drag gauges? 27-Sep-19 02:51 PM Kinda 27-Sep-19 02:51 PM d'you guys read the job description that I posted yesterday? 27-Sep-19 02:51 PM But that's where I have to shut up 27-Sep-19 02:51 PM nasa needs a high vacuum watchmaker 27-Sep-19 02:51 PM you seem to fit the bill 27-Sep-19 02:51 PM Lol what? 27-Sep-19 02:51 PM assembly of spaceflight mass spectrometers 27-Sep-19 02:51 PM Mass spec eh? 27-Sep-19 02:51 PM A person is required to perform detailed, hi precision assembly of miniaturized mechanical parts for laboratory and spaceflight mass spectrometers as well as other delicate scientific instruments. The ability to read/ interpret engineering drawings is required assuring individual parts are within the specified tolerances. Exceptional organization skills and practices such as parts tracking and adherence to quality control procedures are needed. A demonstrated ability to assemble small, complex parts is desired. Experience using small conventional machining equipment, microscopes, inspection systems and assembly tools is essential. Most assembly will be performed under cleanroom conditions. Knowledge of vacuum technology and chemical cleaning procedures is desirable, however not necessary as this can be part of the training. A basic understanding of some physics and electrical principles would be very helpful in performing this work. 27-Sep-19 02:51 PM this is in MD 27-Sep-19 02:52 PM Well it seems perfect 27-Sep-19 02:52 PM no joke 27-Sep-19 02:52 PM you should apply! :P 27-Sep-19 02:52 PM I should send an emial to be like: watup... but let them know 1) I have a year left.. 2)... I have machines in OH 27-Sep-19 02:52 PM like, the plan is to setup shop in OH 27-Sep-19 02:53 PM drop the 2) 27-Sep-19 02:53 PM they have many and more impressive machines than you 27-Sep-19 02:53 PM if they want to give a thumbs up on a cleanroom that I build out there.... and I assembly things remotely... can do 27-Sep-19 02:53 PM :P 27-Sep-19 02:53 PM you can't 27-Sep-19 02:53 PM my machines arent made anymore 27-Sep-19 02:53 PM theirs aren't made either unless you have pockets full of gold 27-Sep-19 02:53 PM but yeah, it's an awesome sorta job 27-Sep-19 02:53 PM and I would likely enjoy something like it 27-Sep-19 02:54 PM I'd go for it if I were you 27-Sep-19 02:54 PM school might be a bit of an issue 27-Sep-19 02:55 PM yeah.. I'd like to learn what is in store for this year 27-Sep-19 02:55 PM but, dayumn cool job 27-Sep-19 02:55 PM plus, you'd get to say: I work for NASA 27-Sep-19 02:55 PM (well, contracted to them) 27-Sep-19 02:59 PM make sure you're contracted to them directly 27-Sep-19 02:59 PM I've heard horror stories of working for a nasa contractor 27-Sep-19 03:00 PM the owner of t he company (I think it is a very small operation) worked as an engineer of the cassini mass specs for 10 years or something 27-Sep-19 03:00 PM started raining 27-Sep-19 11:57 PM Morning! 28-Sep-19 04:33 AM Does this sound reasonable for a gas ballast? 28-Sep-19 04:56 AM with it open the pump has ~2x its base pressure, I've been told that's the normal value 28-Sep-19 04:56 AM it just is a bit louder than expected 28-Sep-19 04:56 AM here's a better look (or listen) 28-Sep-19 05:20 AM Plasma cleaning devices... Is it literally just high voltage and a vacuum? / Tinted with oxygen? 28-Sep-19 05:20 AM Or do I need RF? 28-Sep-19 05:35 AM I need to plasma clean PTFE sheet 28-Sep-19 07:00 AM (if anyone is interested in the outcome, I ran the pump for an hour with the ballast open and it went from >2e-2 mbar to <1e-2 28-Sep-19 07:00 AM still factor of 5 worse than spec, but that thing is old, I don't know its history and it's only backing my turbo 28-Sep-19 08:02 AM @DUIofPhysics lots of plasma devices, DC, RF, inductively coupled... 28-Sep-19 08:02 AM Lots of different gasses you can use too 28-Sep-19 08:05 AM Hnm 28-Sep-19 08:05 AM How would one work out the frequency and power requirements? 28-Sep-19 08:05 AM If I wanted to excite oxygen for RF plasma cleaning? 28-Sep-19 08:07 AM I think everyone has settled for 13,5Mhz because it's an open band. 28-Sep-19 08:07 AM (as far as I can recall from a previous discussion) 28-Sep-19 08:16 AM @GigaSquirrel One of my Welch Direct Drive pump has a gas ballast that sounds like that as well. But the sound generally dies down a bit after like a minute 28-Sep-19 08:16 AM cool, thanks! 28-Sep-19 08:16 AM do you know why it dies down? 28-Sep-19 08:16 AM No idea 28-Sep-19 08:16 AM shouldn't it be constant all the time? 28-Sep-19 08:18 AM Might be just due to the pressure increase. Once it stabilized it sounded better. I haven't had to use the gas ballast for an extended amount of time though, and the pump is quiet with it closed 28-Sep-19 08:18 AM hmmm, ok 28-Sep-19 08:18 AM I'm just gonna assume everything is fine with my pump 28-Sep-19 11:00 AM @Nixie so the thing is 28-Sep-19 11:00 AM yeah? 28-Sep-19 11:00 AM we don't need a huge scan area 28-Sep-19 11:00 AM so if you drive the focus tighter on a CRT 28-Sep-19 11:00 AM you lose the deflection on electrostatics 28-Sep-19 11:00 AM but it shooooooould get a tighter spot 28-Sep-19 11:01 AM Worth trying for sure! 28-Sep-19 11:02 AM if I can get 100-500x magnification on a CRT, I'll be confident I can push it further with a vidicon 28-Sep-19 11:02 AM I am aiming at 10x10mm max, wich is less than the vidicon scan area in any case. 28-Sep-19 11:02 AM yeah, and that's still plenty for any SEM 28-Sep-19 11:02 AM or electron beam etch-a-sketch 28-Sep-19 11:02 AM Good step by step approach, in any case. 28-Sep-19 11:02 AM you'll need to figure out how to implement beam blanking... 28-Sep-19 11:02 AM unless your vidicon has grids 28-Sep-19 11:03 AM Hmmm... 28-Sep-19 11:03 AM let me check 28-Sep-19 11:03 AM I am not sure if it has grids for that 28-Sep-19 11:06 AM you'll have a very messy etch a sketch if you don't blank your beam between segments 28-Sep-19 11:06 AM but I think it does, as the schematic of the vidicon matches the schematic of the CRT 28-Sep-19 11:06 AM and the CRT did blank. 28-Sep-19 01:59 PM ... at what point do you know you've overtightened a CF flange? 28-Sep-19 01:59 PM I am currently at the point where the bolts no longer want to go and I have another ~100um between the flanges 28-Sep-19 01:59 PM I can see the copper gasket inside 28-Sep-19 02:34 PM Normally the metal surfaces should meet fully tightened, depends on the screws you use here are some torque values 28-Sep-19 02:34 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-0D4F4.png 28-Sep-19 02:41 PM I've tightened them way beyond 4nm 28-Sep-19 02:41 PM they're closer to strip-the-head-nm 28-Sep-19 02:43 PM Stupid question...could it be that the copper gasket is too thin? 28-Sep-19 02:43 PM thick 28-Sep-19 02:43 PM but I did buy CF1.33" specific oxygen free gaskets 28-Sep-19 02:43 PM Where are the 100um left? 28-Sep-19 02:43 PM between the flange faces 28-Sep-19 02:44 PM I didn't know they are supposed to meet, I thought that once the gasket was pinched, it was enough. 28-Sep-19 02:44 PM yeah that's my impression 28-Sep-19 02:44 PM I guess with larger flanges they'd meet 28-Sep-19 02:44 PM since it's CF, not KF 28-Sep-19 02:44 PM if your KF flanges meet, you may be hulk. 28-Sep-19 02:45 PM 28-Sep-19 02:45 PM but now the vacuum station is mostly ready 28-Sep-19 02:45 PM active pirani gauge, hot cathode ion gauge 28-Sep-19 02:46 PM for measuring from atm to 1*10^-9 28-Sep-19 02:46 PM now I need to machine a soft vent valve 28-Sep-19 02:48 PM Soft vent valve? Like, a very small pinhole? 28-Sep-19 02:48 PM yep 28-Sep-19 02:48 PM that's the plan 28-Sep-19 02:48 PM a large flat bolt with a flat flange on the other end, viton between them 28-Sep-19 02:48 PM pinhole at the bottom of the bolt hole, KF16 flange 28-Sep-19 02:48 PM I did a very fancy one in stainless 28-Sep-19 02:48 PM I only have aluminium stock 28-Sep-19 02:48 PM I'd do it out of stainless 28-Sep-19 02:49 PM Should work too, just a bit soft compared to 304 28-Sep-19 02:49 PM my lathe will be thankful 28-Sep-19 02:50 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190928_235016-02406.jpg 28-Sep-19 02:50 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190928_235022-67682.jpg 28-Sep-19 02:50 PM OOooo 28-Sep-19 02:50 PM that, my friend, is entirely too many parts 28-Sep-19 02:50 PM :D 28-Sep-19 02:50 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190928_235027-F9F49.jpg 28-Sep-19 02:50 PM Yeah, fancy as f**k 28-Sep-19 02:51 PM my valve will just be a viton-reinforced bolt 28-Sep-19 02:51 PM with no gas feed 28-Sep-19 02:51 PM or maybe I should add gas feed... 28-Sep-19 02:51 PM Gas feeds are nice to have, and can always vent to atm if necessary 28-Sep-19 02:53 PM I might replace it with a mass flow controller at some point 28-Sep-19 02:53 PM to fill nixies 28-Sep-19 02:54 PM I'm already full, thanks. 28-Sep-19 02:54 PM ... should I take a nap... or drink some coffee.... 28-Sep-19 02:54 PM I shouldnget a mfc, but for what I'm doing now, I can get by without. 28-Sep-19 02:54 PM Drink a nap? 28-Sep-19 02:55 PM if only I knew how 28-Sep-19 02:55 PM pentobarbital 28-Sep-19 02:55 PM Invent, adapt, overcome. 28-Sep-19 02:55 PM Does Elon Musk take pentobOrbital? 28-Sep-19 02:55 PM or benadryl 28-Sep-19 02:56 PM Ba, dum, ts! 28-Sep-19 02:56 PM "You can't sneeze if you're unconscious™" 28-Sep-19 02:56 PM I recently watched the NYC CNC video on the 10 tips for successful busniness tuff... and in it they list have a plan, then next tick was be flexible to change the plan... that caught me offgaurd slightly because Linus Torvalds says: dont have a plan 28-Sep-19 02:56 PM Well, the same.linus torvalds that berated coworkers... 28-Sep-19 02:57 PM I understand being agile and so forth 28-Sep-19 02:57 PM Would.not follow his advice. 28-Sep-19 02:57 PM the faces of an cf flange are supposed to meet, but if it does seal it should be ok 28-Sep-19 02:57 PM well, he made something that changed the world, more or less 28-Sep-19 02:57 PM I like the idea of goals, not plans 28-Sep-19 02:57 PM Doesn't give him.any moral rights. 28-Sep-19 02:58 PM did you read his apology? 28-Sep-19 02:58 PM https://lkml.org/lkml/2018/9/16/167 28-Sep-19 02:58 PM Nope...lets see 28-Sep-19 03:06 PM btw, went with that espresso 28-Sep-19 03:06 PM only 3pm, and I turned on the machine this morning without pulling a shot, so might as well have had one 28-Sep-19 03:09 PM Meh, an apology under duress 28-Sep-19 03:11 PM there are articles that exam it.. just search torvalds apology .. I guess it wasn't the first time 28-Sep-19 03:11 PM so, in one of those videos where I hear the 'dont have a plan' .. it's actually of Torvalds' boss (if there is such a thing) at a Ted (TedX?) and another point was: You dont have to be nice 28-Sep-19 03:11 PM the 3rd point they say is: give it all away 28-Sep-19 03:11 PM I was taking notes from that for t he idea of starting a YT channel.. initial thoguth was chemistry, but now it will be watchmaking.. maybe some chem shoved in there, but mostly watchmaking 28-Sep-19 03:11 PM btw, the purchase for that automatic pinion cutter went through he'll store it for a year for whence I return 28-Sep-19 03:14 PM Nice! 28-Sep-19 03:15 PM I kind of know him, and yes, I was right about where the machines came from 28-Sep-19 03:15 PM so, he kind of wanted me to have it more than anyone else 28-Sep-19 03:15 PM Btw, thought of you today in anantique flea market 28-Sep-19 03:15 PM OOooo 28-Sep-19 03:15 PM we actually went into a second-hand market place today on our morning walk, played with another dog inside, and left.. without looking at anything.. I should go through their jewelry/watches sometime 28-Sep-19 03:15 PM likely something in there 28-Sep-19 03:17 PM Wait for the photo 28-Sep-19 03:17 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190928_114323-DA571.jpg 28-Sep-19 03:18 PM cuute 28-Sep-19 03:19 PM Sold as is, no accesories. Shame. 28-Sep-19 03:19 PM yeah, the accesories are really what makes a small watchmaker's lathe worth anything 28-Sep-19 03:19 PM Yeah. 28-Sep-19 03:20 PM $1500 USD for a full set of simple accesories is not uncommon 28-Sep-19 03:20 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190928_112308-34750.jpg 28-Sep-19 03:20 PM Saw a few other things, but didn't end buuing anything 28-Sep-19 03:20 PM I cant buy anything until my stock sale goes through 28-Sep-19 03:20 PM well, maybe on credit card 28-Sep-19 03:20 PM I was not expecting to buy those machines.. but they were available, so I had to jump on it 28-Sep-19 03:20 PM I think I have like 5 major machines left on the list 28-Sep-19 03:22 PM 28-Sep-19 03:22 PM I really hope to see your watches somewhere someday. 28-Sep-19 03:22 PM Like very collectible pieces. 28-Sep-19 03:29 PM well, if I make only 100 a year, then that is fairly collectable 28-Sep-19 03:29 PM I asked the one dude in class that states he really wants to get into manufacturing if he would be willing to move where I "plan" on being.. and basically said 'no' 28-Sep-19 03:29 PM oh.. I am somewhat designing a small watchmakers jig boring/milling machine.. since we dont have one in class that is worthy 28-Sep-19 03:29 PM right now just sketches 28-Sep-19 03:29 PM it'll come down to: what can I produce with the machines I have on hand 28-Sep-19 03:29 PM only looking at ~150mm travel in ea axis 28-Sep-19 03:36 PM Well, frick him. 28-Sep-19 03:36 PM Be a single man watchmaker genius and playboy. 28-Sep-19 03:36 PM hah, yeah.. it'll be just me 28-Sep-19 03:36 PM Philantropist too. 28-Sep-19 03:36 PM Billionare, too 28-Sep-19 03:36 PM Genius.. 28-Sep-19 03:37 PM I can help making big acrylic versions on the laser cutter 28-Sep-19 03:37 PM https://www.youtube.com/watch?v=VVyoXimCrdQ 28-Sep-19 03:38 PM That can be you. 28-Sep-19 03:38 PM Make a five axis tourbillon. Rotates in three axes and then around the watch AND around the whole wrist strap. 28-Sep-19 03:39 PM I actually know of someone who made the whole mvoement rotate inside t he watch 28-Sep-19 03:39 PM I had an idea of putting the mvoement on the autoamtic rotor.. havent quite figured out the nuances just yet 28-Sep-19 03:40 PM Yeah, saw it too long ago 28-Sep-19 03:40 PM It looked fantastic 28-Sep-19 03:46 PM doh, I need to go to the plastics store sometime.. may just order what I need as I wont be able to get to it till next weekend 28-Sep-19 03:46 PM it is mroe or less what is inhibitting me from using the new grinder machine 28-Sep-19 03:46 PM protecting the ways and such 28-Sep-19 03:58 PM Important. Grinder machines don't forgive. 28-Sep-19 03:58 PM right 28-Sep-19 03:59 PM (time to sleep here) 28-Sep-19 03:59 PM have a good one 28-Sep-19 03:59 PM Thanks! 29-Sep-19 02:41 AM Morning! 29-Sep-19 02:42 AM Moin! 29-Sep-19 03:45 AM moin 29-Sep-19 04:14 AM @Nixie Need to make a 'Watchmakers 5 axis CNC' 29-Sep-19 04:15 AM why only 5? 29-Sep-19 04:15 AM xD 29-Sep-19 04:15 AM https://www.youtube.com/watch?v=F8iisuprgVQ 29-Sep-19 04:15 AM woah 29-Sep-19 04:15 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-9FC14.png 29-Sep-19 04:15 AM http://wwlathetools.blogspot.com/p/the-fully-dressed-watchmakers-lathe.html O.o 29-Sep-19 12:13 PM Damn things of beauty 29-Sep-19 12:13 PM @DUIofPhysics yeah, why not? 29-Sep-19 12:24 PM @DUIofPhysics I got my little watchmaker's lathe from Niels 29-Sep-19 12:24 PM huh ok 29-Sep-19 12:25 PM a Lorch Junior 29-Sep-19 12:25 PM also, in case you havent gathered it yet.. I am a watchmaking student.. just started second (final) year 29-Sep-19 12:25 PM it's more of service and repair, but we do learn some manufacturing (though not enough) 29-Sep-19 12:25 PM I'm actually half way trying to design a small watchmaker's jig boring machine right now 29-Sep-19 06:46 PM Does a little tiny Swiss man (complete with tiny mustache) come with that mega lathe setup to run it for you??? 29-Sep-19 08:43 PM XDDDD 30-Sep-19 09:49 AM @Noxz Oh god, I just read 'I got my little watchmaker's lathe from Nazis' 30-Sep-19 09:49 AM xD 30-Sep-19 09:55 AM Dunst 30-Sep-19 12:14 PM moin 30-Sep-19 12:55 PM Night! 30-Sep-19 03:33 PM https://youtu.be/B3aukYST880 30-Sep-19 03:43 PM Aplied Ion's plasma thruster live testing! 30-Sep-19 03:55 PM @Nixie That's me you hear in the background lol 30-Sep-19 03:55 PM Can't stay to watch it in person for too long though 30-Sep-19 04:21 PM Finally firing right lol 30-Sep-19 04:21 PM Took 1.5 hours, had to boost input to 5V 01-Oct-19 11:44 AM Glad to hear you, @Mason_Yu ^^ 01-Oct-19 11:44 AM Sorry @Applied_Ion that I could not stay longer, but I was sleep deprived and needed to rest. 01-Oct-19 11:45 AM Oh no worries at all, I wouldn't expect anyone to stay the full test lol 01-Oct-19 11:45 AM Most of it ended up being troubleshooting anyway 01-Oct-19 11:45 AM I'm taking apart and debugging it tonight, and will try to run another live stream tomorrow with new caps and running at 4V. I was told I can get 4V direct from satellite bus. 3.3V is too low after a bunch of shots, and 5V works great but blows stuff up, so let's see if there is a middle ground here at 4 lol 01-Oct-19 12:09 PM @GigaSquirrel I noticed your trivac pump in your tweets 01-Oct-19 12:09 PM Is it really that quiet with no gas ballast? Almost silent? 01-Oct-19 12:09 PM I really want a silent forepump. 01-Oct-19 12:09 PM yes 01-Oct-19 12:09 PM I need that pump now 01-Oct-19 12:09 PM opens up ebay 01-Oct-19 12:09 PM mine sounds like a demon skeleton is inside it, the vanes hate you and everything you stand for 01-Oct-19 12:09 PM opening the gas ballast also makes it hate itself 01-Oct-19 12:09 PM oh my god the trivacs are expensive 01-Oct-19 12:09 PM o k 01-Oct-19 12:11 PM xD 01-Oct-19 12:11 PM got mine without oil for 160 in an auction 01-Oct-19 12:11 PM the oil costs more than my pump 01-Oct-19 12:11 PM D: 01-Oct-19 12:11 PM but the silence... 01-Oct-19 12:14 PM Yeah, silent pumping would be nice. Mines like a jack hammer lol 01-Oct-19 12:14 PM But it works, and was the right price 01-Oct-19 12:14 PM I thought that you couldn't get a forepump that was so quiet 01-Oct-19 12:14 PM but apparently you can 01-Oct-19 12:15 PM You can get pretty quiet ones 01-Oct-19 12:15 PM The belt drive ones are also very quiet 01-Oct-19 12:27 PM Don't we all hate @GigaSquirrel ? XDDD 01-Oct-19 12:27 PM My pump also sounds like a jackhammer. At least I'll have a workshop for it to not annoy people. 01-Oct-19 12:28 PM Mine is fairly quiet, but sounds angry and is annoying enough to not want to run it in the background 01-Oct-19 12:28 PM but the trivac sounds almost completely silent judging by the video, and I must have that 01-Oct-19 12:30 PM Has everyone thought that he might have it switched off and is just playing with our feelings? 01-Oct-19 12:30 PM but I saw the mist 01-Oct-19 12:30 PM after effects. 01-Oct-19 12:30 PM XDDDDDDDDDDD 01-Oct-19 12:35 PM @Nixie true, even I hate that idiot! 01-Oct-19 12:35 PM I wonder what other pumps are as quiet as that 01-Oct-19 12:35 PM nobody suggest the sprengel pump 01-Oct-19 12:38 PM holding @GigaSquirrel hand /why...slap!...are...slap!...you...slap!...hitting...slap!...yourself...?/ 01-Oct-19 12:38 PM @Deleted User kidding apart, and not as a joke-ish, a mercury pump (with it's own troubles, of course) 01-Oct-19 12:41 PM Which is why I just said not to suggest it 01-Oct-19 01:57 PM Uh, is sprengel, mercury? 01-Oct-19 01:57 PM If it is, sorry, not everyone here speaks german. 01-Oct-19 02:02 PM sprengel pump is the name of a pump using mercury 01-Oct-19 02:02 PM mercury in german would be quecksilber 01-Oct-19 02:55 PM Is that "fast silver"? 01-Oct-19 02:55 PM Here it is "elohopea", which translates to something like "live/living silver" 01-Oct-19 02:55 PM Tho "eloisa" is lively, so that sort of relates to it. And "lively silver" is such a comfy translation. 01-Oct-19 02:57 PM not exactly, queck is old german for something like "alive" iirc 01-Oct-19 02:57 PM apparently queck / quick means "alive, moveable" 01-Oct-19 02:58 PM Ah 01-Oct-19 08:49 PM Quecksilber sounds like germans didn't want to make the effort to find a proper own word and just said, "how can we rewrite Quicksilver, so we don't write it like americans?" but then even that fell halfway through. @Deleted User in any case, sorry, I did not know that was the pumps name, I supposed it was a different type, like scroll or something. 01-Oct-19 08:53 PM heh 02-Oct-19 03:13 PM https://i.imgur.com/WdFqAx8.jpg 02-Oct-19 03:13 PM It's wonderful how small and effecient pneumatics have gotten. 02-Oct-19 03:42 PM Whatcha making? 02-Oct-19 04:02 PM Getting back around to finally working on the ISI again... 02-Oct-19 04:02 PM All the old pneumatics are shot. Leak like crazy. 02-Oct-19 04:02 PM They "work" but yea... If you notice the old valve are basically a fire hazard due to all the insulation falling off the wires from baking forever. 03-Oct-19 10:27 AM Joined the server. 03-Oct-19 10:30 AM Invited ChrisSmol over from a different discord. Apparently he has worked on interesting detectors. 03-Oct-19 10:34 AM thanks for the invite! in a former life i worked in industrial nuclear gauging. we made systems to measure the thickness of materials while they were being made (metal, plastics, paper etc) using the attenuation of radiation (beta, and gamma / x-ray mostly) via ionization chambers, scintillation detectors, photodiodes, etc. 03-Oct-19 10:57 AM Welcome! 03-Oct-19 12:17 PM @ChrisSmol is going to have a huge fan in @GigaSquirrel 03-Oct-19 12:26 PM oh i see we have a #lasers_and_optics here as well 03-Oct-19 02:38 PM We have a diagnosis for Lucas 03-Oct-19 02:38 PM You have hyperhydrosis (fancy word for sweating a lot) 03-Oct-19 02:38 PM Basically, we need to cut your arms and legs 03-Oct-19 02:38 PM What quality of life will you have without arms and legs? 03-Oct-19 02:40 PM ...what are you even talking about? 03-Oct-19 02:42 PM The question is if we can harvest your organs 03-Oct-19 03:06 PM ... 03-Oct-19 03:06 PM dibs on the kidneys. 03-Oct-19 03:13 PM uhhh, i always wanted an organ 03-Oct-19 03:13 PM but without donator, i can't afford that 03-Oct-19 05:53 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/outgas1-67E55.jpg 03-Oct-19 05:53 PM I think outgassing is not well understood 03-Oct-19 05:53 PM When I said I will use silicone adhesive to make the vacuum chamber some people said it will outgass forever 03-Oct-19 05:53 PM But from this graph I see outgassing rate diminishes with time 03-Oct-19 05:53 PM Maybe I can wait some time before turn on the gun 03-Oct-19 06:08 PM You'll be at least 4-5 orders of magnitude short of your goal(of -11, which is quite extreme already) if you manage to make the absolute best silicone adhesive chamber. I'm talking about HTV silicone by the way, not RTV. You won't get near even the 4-5 orders below with RTV due to the chemistry. 03-Oct-19 06:08 PM Outgassing is very well understood, and that graph is meaningless, especially with no numbers 03-Oct-19 07:45 PM good evening! 03-Oct-19 08:36 PM Morning! 04-Oct-19 09:14 PM @qualia was that you posting on Twitter a while ago about the mini turbo pumps? 04-Oct-19 09:24 PM maaaaybe? 04-Oct-19 09:24 PM i am never not posting and that sounds plausible 04-Oct-19 09:24 PM i do kinda want a tiny KF turbo just for a l'il pumping station 04-Oct-19 09:24 PM and i definitely did crawl up john mcmaster's butt abt using one as a booster to back a diffusion pump in a SEM 04-Oct-19 09:29 PM I seem to recall the post featuring something like AliExpress or maybe TaoBao... But I can't remember if I'm just dreaming 04-Oct-19 09:31 PM oh, dunno then 04-Oct-19 09:31 PM maybe someone else 04-Oct-19 10:28 PM @qualia pfeiffer make a KF...25? turbo! 04-Oct-19 10:28 PM yeah, KF25 04-Oct-19 10:28 PM https://www.pfeiffer-vacuum.com/en/products/vacuum-generation/turbopumps/hybrid-bearing/hipace-10/5420/hipace-10-with-tc-110-and-power-supply-pack-ops-40-dn-25 04-Oct-19 10:28 PM it's adorbs 04-Oct-19 10:28 PM I kinda want to try making one 04-Oct-19 10:28 PM whoa, Honeywell developed a MEMS turbopump 04-Oct-19 10:28 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/90-39D7A.png 04-Oct-19 10:28 PM and University of Michigan made an equally tiny 24-stage forepump 04-Oct-19 10:28 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/90-B1227.png 04-Oct-19 10:36 PM That's so neat 04-Oct-19 10:36 PM I wonder if it's possible to DIY this kind of turbopump by just layering tons of metal layers on top of each other 04-Oct-19 10:36 PM it'd be quite useless without a way to seal and spin it 04-Oct-19 10:36 PM but metal on metal on metal deposition... even being MEMS, surely it's easier than making full ICs? 04-Oct-19 10:36 PM make wedge-style alignment jigs for repeating the process... or even depositing with a rotating mask in situ 04-Oct-19 10:36 PM though the latter is probably impossible unless you make tapered(triangular) blades, since you can't deposit on nothing 04-Oct-19 10:47 PM What kind of bearing do you even put this on? MEMS bearing? It needs so much speed to get anywhere close to the molecular speed 04-Oct-19 10:48 PM I'm guessing you could maybe grow some sapphire pins 04-Oct-19 10:48 PM but then how do you spin a bit of... silicon(?) or pure metal 04-Oct-19 10:50 PM Looks like they made it on silicon, could be driven with an induction motor? 04-Oct-19 10:50 PM They apparently go up to 55000 rpm 04-Oct-19 10:50 PM 55krpm isn't enough for a lot of regular turbos though 04-Oct-19 10:50 PM I imagine this would need to spin closer to 500krpm 04-Oct-19 10:51 PM Yeah, but will the wafer even hold up to that speed? 04-Oct-19 10:51 PM That's insanely fast, it might just have to operate relatively inefficiently for each stage and just have tons of stages 04-Oct-19 10:52 PM I imagine it would 04-Oct-19 10:52 PM but yeah, if you can mass-produce these on a wafer, it makes sense to stack 10, 20, 50 of these in series 04-Oct-19 10:52 PM and get a turbo that can pump a few ml/s 04-Oct-19 10:52 PM I believe the project was started around 2008 by darpa, and the goal was to evacuate chambers smaller than 3mm^3 04-Oct-19 10:54 PM Like what they did for the 24 stage forepump, DARPA is funding that too 04-Oct-19 10:55 PM the only interview where these photos came from can be summed up by this sentence: 04-Oct-19 10:55 PM Wong: How small can the pumps be? Yang: Our micro vacuum pump consists of two silicon wafers – each slightly smaller than a U.S. penny -- that are attached to a small motor capable of spinning the wafers at a high speed. 04-Oct-19 10:55 PM about as much info as the picture shows... 04-Oct-19 10:55 PM but it looks like it's attached to a regular motor with a metal shaft: 04-Oct-19 10:55 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/96371_fig1-3FB76.png 04-Oct-19 10:55 PM sometimes I feel like building a 5-axis mini CNC system with a Nakanishi spindle to build micro turbos at home 04-Oct-19 11:03 PM https://www.hems-workshop.org/6thWS/Talks/Kline-Schoder.pdf 04-Oct-19 11:03 PM Want to make that? 04-Oct-19 11:04 PM give me a budget to buy the parts and I will :P 04-Oct-19 11:04 PM there's a few EM-3060 spindles with ATCs and controllers on eBay for ~$1300 04-Oct-19 11:04 PM 350W @ 60krpm 04-Oct-19 11:04 PM plus a 5 axis positioning stage... 04-Oct-19 11:04 PM at that scale you can probably use not-machining-related lab translation stages 04-Oct-19 11:04 PM (optical/bio) 04-Oct-19 11:04 PM I won't mention the price of the NSK collets though 04-Oct-19 11:11 PM Two of these tiny turbos is currently on Mars 04-Oct-19 11:11 PM On the Curiosity rover 04-Oct-19 11:11 PM venting to atmosphere I bet 04-Oct-19 11:11 PM cheating! 04-Oct-19 11:12 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-A9586.png 04-Oct-19 11:12 PM I could totally make the impeller on page 7 if I spent the money to build a 5-axis micromachining center 04-Oct-19 11:12 PM or even one on page 12 04-Oct-19 11:12 PM In what material? 04-Oct-19 11:13 PM at that point, anything 04-Oct-19 11:13 PM a single part would take days to machine and probably hundreds of dollars in consumables though 04-Oct-19 11:13 PM at that point you can't run tools until they start getting dull, you only get maybe 1-2 hours of machining time tops until a tool that feels and looks sharp is unusable 04-Oct-19 11:13 PM (for anything but roughing) 04-Oct-19 11:17 PM Ball bearings that can handle 100krpm to 200krpm 04-Oct-19 11:17 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-9E2D9.png 04-Oct-19 11:17 PM hard ceramics can easily handle 1M 04-Oct-19 11:17 PM but any imbalance and any vibration turns them into dust 04-Oct-19 11:17 PM this kind of stuff is machined on temperature-stabilized KERN granite epoxy machining centers 04-Oct-19 11:17 PM and if I had to guess, actually by KERN in their job shop 04-Oct-19 11:17 PM if I were to build my own, I'd do it slightly differently, but still with epoxy granite 04-Oct-19 11:17 PM I have a friend with a full machine shop and a WEDM system that is mostly idle 04-Oct-19 11:22 PM is that forepump just little high-deflection piezo elements or is that mems too 04-Oct-19 11:22 PM I think it's mems with piezo 04-Oct-19 11:43 PM That bearing in the turbo is actually retained in vibration dampening material (plastics) to enable it to go through all the resonances when it accelerates. It survived launch and landing and is still working after more than 7 years 04-Oct-19 11:43 PM No maintenance, no adding lubricant and yes, exhausting directly to atmosphere 04-Oct-19 11:43 PM Need a Datron CNC machine 05-Oct-19 12:04 AM datron can't do this 05-Oct-19 12:04 AM it's likely machined on KERN machines 05-Oct-19 01:46 AM I want a KERN ._. 05-Oct-19 02:21 AM I want a cern 05-Oct-19 09:22 AM @Deleted User actually dentistry turbines run between 400 and 800k even though they are not in the cleanestof environments and also experience some mechanical load 05-Oct-19 09:22 AM high speed isnt as magical as all the manufacturers want you to believe 05-Oct-19 09:25 AM @george dentistry turbines run on slightly wet air bearings though 05-Oct-19 09:25 AM and they're really just a little nut slowly wearing itself away 05-Oct-19 09:26 AM nonono 05-Oct-19 09:26 AM they are plain hybrid ballbearings 05-Oct-19 09:26 AM my dad does the service on his turbines himself, we have those bearings y the dozend somewhere around 05-Oct-19 09:26 AM ill try to get a pic later 05-Oct-19 09:27 AM are you sure the bearing ones run at 400-800k? 05-Oct-19 09:28 AM jup 05-Oct-19 09:28 AM they allways did 05-Oct-19 09:28 AM well, maybe not 800k, thats more modern but 400-500 is no problem to them 05-Oct-19 09:28 AM dont underestimate the reduction in circomferal speed in such things 05-Oct-19 09:28 AM i once had to seal 50kmin⁻¹ and expected having to do some crazy hih tech solution 05-Oct-19 09:28 AM turns out on 8mm shaft diameter even normal radial ruber seals are in spec 05-Oct-19 09:28 AM same goes for bearings, even 0608 is rated to 50k if you ask a proper manufacturer 05-Oct-19 09:28 AM the magic is in lubricating them for life and there im not sure about things 05-Oct-19 09:43 AM all the turbines I've seen have had wet air going through them for power and lubrication 05-Oct-19 11:09 AM The ones i know use prelubrication by the personel 05-Oct-19 11:09 AM they are first sterilized and then flushed with a special lue spray 05-Oct-19 11:09 AM it will last the time needed for one patient 05-Oct-19 10:21 PM https://media.discordapp.net/attachments/529468991652233216/630227982786625537/DSC_2750.JPG 05-Oct-19 10:21 PM https://media.discordapp.net/attachments/529468991652233216/630248136127807507/DSC_2751.JPG 05-Oct-19 10:21 PM SEM came back OK with the new pneumatics tonight. 05-Oct-19 10:21 PM Well OK to where it was before. Still probably needs column cleaning and well other stuff. 05-Oct-19 10:21 PM Need to organize a bit and clean up bench space before doing that though. 05-Oct-19 11:07 PM https://posifatech.com/wp-content/uploads/2019/08/Datasheet_PVC3000_Vacuum_RevC_C1-1.pdf 05-Oct-19 11:07 PM Well this is super cool 05-Oct-19 11:07 PM a thermopile vacuum gauge, in a can, with MEMS bolted onto it 05-Oct-19 11:07 PM wonder how much it costs 05-Oct-19 11:07 PM it's super new, only released this month 05-Oct-19 11:10 PM cool 05-Oct-19 11:10 PM I can see this being used in an array of sensors to monitor foreline pressure in complex setups 05-Oct-19 11:11 PM Yea I mean most of the time they just pair pirani and piezo into one package and call it a day. 05-Oct-19 11:11 PM That's what the MKS 901ps are 05-Oct-19 11:11 PM MEMS pirani exists, yeah, it's those 05-Oct-19 11:11 PM I'd assume this is aimed at cost reduced part reduced integrated solutions. Not so much standalone 05-Oct-19 11:12 PM yeah, no flanges on it 05-Oct-19 11:15 PM I suppose I more meant like, integrated into a larger product not say just a standalone gauge. But I suppose its possible to see companies like MKS or Pfeiffer integrate them into standalone gauges. 05-Oct-19 11:15 PM I'm going to guess that the big guys have their own near-zero-bom-cost deals 07-Oct-19 08:59 AM Got my cheap chinese RF amps today, ofc without any assembly instructions 07-Oct-19 08:59 AM https://pa0fri.home.xs4all.nl/Lineairs/RF-AMP-2078/4Z4TJ%20(1).pdf But I found this 07-Oct-19 08:59 AM @qualia weren't you looking for the instructions as well? 07-Oct-19 10:21 AM naw i found those same ones 'n i've been using 'em 07-Oct-19 10:22 AM great 07-Oct-19 10:22 AM have you tried the thing yet? 07-Oct-19 10:22 AM i gotta get on with building my kit soon.. weh. i got some little SMD tweezers so now i have no excuse 07-Oct-19 10:22 AM nah 07-Oct-19 10:22 AM actually i could probably definitely come up with more excuses if need be 07-Oct-19 10:23 AM just do it 07-Oct-19 10:23 AM have some ICP fun 07-Oct-19 10:23 AM or CCP, might also be interesting 07-Oct-19 10:23 AM just don't go to CCCP 07-Oct-19 02:44 PM PERESTROIKA!!!! 07-Oct-19 02:46 PM bless you! 08-Oct-19 12:35 AM ROFL 08-Oct-19 03:55 AM <__ice9#6039> Intriguing 08-Oct-19 03:55 AM <__ice9#6039> Re: SMD, could also perhaps try https://twitter.com/__ice9/status/1177839345958563841?s=19 08-Oct-19 03:55 AM <__ice9#6039> https://twitter.com/GregDavill/status/1166718850047414272?s=19 08-Oct-19 03:55 AM <__ice9#6039> Some other cheap amp designs based on IRF510s-- https://www.g0kla.com/scpa/SimpleCheapPA.php 08-Oct-19 03:55 AM <__ice9#6039> http://frenning.dk/OZ1PIF_HOMEPAGE/50MHz_IRF510.htm 500W and can be paralleled (with appropriate splitting/recombination) or just scaled up further 08-Oct-19 11:50 AM Joined the server. 08-Oct-19 07:12 PM How bad are thoriated tungsten rods for health? 08-Oct-19 07:12 PM I'm using 2% thoriated 08-Oct-19 07:12 PM I'm not dying from cancer yet 08-Oct-19 07:17 PM the thorium accumulates and has a very long biological decay time. so it's hard to tell if your cancer in 10 years is caused by thorium or other things 08-Oct-19 09:24 PM 'yet' 09-Oct-19 04:25 AM "In a review of air sampling measurements carried out during grinding it was concluded that during grinding air concentrations could approach or even exceed concentrations at which it would be necessary to consider designating the area as a controlled area as defined by the Ionising Radiation Regulations 1999." 09-Oct-19 04:25 AM "However, the risk of cancer in TIG welders due to thoria exposure is very low, since the exposure times to individuals are invariably small. The Danish Welding Institute estimates that of 1200 full-time TIG welders, a cancer incidence of 0-3 may occur during a thirty year working life. While this figure is considered acceptable, the Danish Welding Institute has recommended that thoriated tungsten be phased out in Denmark since non-radioactive alternatives are available." 09-Oct-19 04:25 AM https://www.twi-global.com/technical-knowledge/faqs/faq-the-use-of-thoriated-tungsten-electrodes Fine during handling. Don't do the Doc Brown move and store it under your bed. The grinding dust is a fast-track to cancer. 09-Oct-19 09:17 AM My recommendation is to not use thoriated tungsten electrodes for tig @chucrut 09-Oct-19 09:17 AM There are equally good, but just slightly more expensive alternatives 09-Oct-19 09:49 AM https://youtu.be/siX4wSotsKk 09-Oct-19 09:49 AM we could crowdfund one, right? 09-Oct-19 10:02 AM Gona be honest. Just feels like the advert for some alien technology out of a video game... Like jeez. Its easy to forget the crazy technology our world has then you have adverts like this. 09-Oct-19 10:03 AM 15Ci/hr production 09-Oct-19 10:03 AM That is terrifying 09-Oct-19 10:03 AM https://i.spirit.re/uCvsa.png 09-Oct-19 10:03 AM Looks so simple inside! Just an ISO...1500(lol) flange with some copper pizza slices! 09-Oct-19 10:03 AM 3kW standby, 45kW when the beam is on, for the lowest power option 09-Oct-19 10:03 AM And a feather light 18 tons 09-Oct-19 10:08 AM with a semi attached it's a portable 09-Oct-19 10:08 AM You'd need another semi with a turboshaft generator to run it 09-Oct-19 10:09 AM @Conmega yeah, right ... esp with this female voice 09-Oct-19 10:10 AM I like that they even produced an advertisement video 09-Oct-19 10:10 AM everyone needs a cyclon kiube now! 09-Oct-19 10:10 AM I have a feeling the potential customers would be flown out to touch it and have a sales rep attached to them at all times 09-Oct-19 10:10 AM If you don't need to produce 1500 chernobyls per hour of radioactive rust, it's pretty feasible to DIY a cyclotron to generate a few(single-digit) uA at a few MeV 09-Oct-19 10:10 AM As complicated as that machine is, at the very basic end cyclotrons are just a pancake vacuum chamber with some plates and an RF feedthrough 09-Oct-19 10:12 AM how does one make a proton source legally? 09-Oct-19 10:12 AM and what can one do with it o3o 09-Oct-19 10:13 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/The-duoplasmatron-proton-source-F6D31.png 09-Oct-19 10:13 AM there's a lot of things you can do 09-Oct-19 10:13 AM almost none are safe though, lol 09-Oct-19 10:30 AM lol 09-Oct-19 12:29 PM I recently learned that most HV transfer (in europe) is coaxial 09-Oct-19 12:29 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Hochspannungskabel_110kV_400kV-416DE.png 09-Oct-19 12:29 PM and I wonder how well their impedance control is 09-Oct-19 12:30 PM is that an aluminium or a steel core on the right? 09-Oct-19 12:30 PM Al methinks 09-Oct-19 12:31 PM but why Oo 09-Oct-19 12:31 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/1024px-Hochspannungskabel_400kV_Querschnit-271A8.png 09-Oct-19 12:31 PM 'cause Al is cheaper I guess 09-Oct-19 12:31 PM but I want to get some and build a blumlein with them 09-Oct-19 12:51 PM Impedance control does not need to be that good for HV DC, it's likely more about consistent quality in the dielectric. 09-Oct-19 12:51 PM But interesting if the HV AC transmission lines also use a shielded cable like that. I ownder if it's some noise thing or capacitive coupling thing. 09-Oct-19 12:53 PM those are AC lines 09-Oct-19 12:53 PM afaik 09-Oct-19 12:55 PM yep, 50 Hz AC 09-Oct-19 12:55 PM @GigaSquirrel for AC line you have to be very aware of impedance the same for normal transmission lines, as stated for DC it is not that bit of an issue but for fault condition it is also again important 09-Oct-19 12:56 PM I know their capacitance starts coming into play, but I'm unsure about the overall impedance 09-Oct-19 12:56 PM lemme rephrase 09-Oct-19 12:58 PM it is inductance and capacitance, if you have high load it becomes inductive. You use that also to further optimize cos phi, just by changing the loading of a power line 09-Oct-19 12:58 PM the energy supplier doesn't care about the cables impedance when they install them, but I wonder how constant it actually is 09-Oct-19 12:58 PM and at what value 09-Oct-19 12:59 PM they build to spec you specify the impedance 09-Oct-19 12:59 PM Depending on how much nominal Power it has to transfer 09-Oct-19 01:00 PM I don't think you understand my question 09-Oct-19 01:00 PM I know cables can be built for a certain impedance, but the ones in our power grid are not, I know that for a fact. But they still have some impedance, and I wonder how constant that actually is, over the whole cable 09-Oct-19 01:01 PM No in the power grid they are build to impedance, as i sad it is very important 09-Oct-19 01:01 PM they are are in the same region as normal Coax cabel from like 40 to 70 ohms 09-Oct-19 01:01 PM if you take like a 2XS(FL)2Y 1 RM/50 it hast for 2000mm² 52,2ohm 09-Oct-19 01:01 PM it is the same problem you have with RF but at high power even at low frequency this is important, maybe i still misunderstand you, sorry 09-Oct-19 01:08 PM I believe the central alu core is actually for mechanical support 09-Oct-19 01:09 PM could also be that it is needed for manufacturing 09-Oct-19 01:10 PM I'm guessing also for mechanical support during manufacturing 09-Oct-19 01:11 PM jup possible 09-Oct-19 01:13 PM @GigaSquirrel you need to build blumleins with those 09-Oct-19 01:13 PM My god at that size you could generate such absurd peak power levels 09-Oct-19 01:15 PM I'll see if I can get my hands on a few meters ^^ 09-Oct-19 01:15 PM If you pulse charge then instead of dc charge them, you can charge them to much higher voltages than spec'd for ac or dc if the pulse is not too wide 09-Oct-19 01:15 PM But even dc charged, you are talking about hundreds of thousands of volts 09-Oct-19 01:16 PM well we have some pulse capacitors... 09-Oct-19 01:18 PM What are the dimensions of the cable? We could estimate impedance on geometry alone 09-Oct-19 01:20 PM will be probably about 50 it is hard without exact knowledge of the dialectic 09-Oct-19 01:20 PM Interfacing supervoltage pulse generators into a real load becomes a big challenge, have to worry about grading the fields through the interface 09-Oct-19 01:20 PM Also you can play some tricks with stacked blumleins to get further voltage gains on the output 09-Oct-19 01:20 PM Most plastic dielectrics will be pretty similar 09-Oct-19 01:20 PM In terms of calculating impedance 09-Oct-19 01:23 PM yes but if you what it down to the ohm you have to be quite precise, and there is allot of magic in the Electric of an HV cable. 09-Oct-19 01:24 PM Eh, that's not super critical. Pulsed power is more about hands on tweaking than calculation 09-Oct-19 01:24 PM ok so 50 ohm it is 09-Oct-19 01:24 PM You can get away with a lot using trash lol 09-Oct-19 01:24 PM 50 ohms is probably a good start lol 09-Oct-19 01:24 PM Problem is with a blumlein the total impedance will be double the single leg, so it will be 100 ohms 09-Oct-19 01:25 PM jup 09-Oct-19 01:26 PM High impedance is great for flash xray drivers where voltage is generally more critical than current 09-Oct-19 01:27 PM but depending on what you want to do you can build quite simple ones out of those HV cables just for tinkering around 09-Oct-19 01:27 PM Oh yeah definitely lol 09-Oct-19 01:27 PM Even regular 50 ohm standard coax for bnc can generate quite high peak power 09-Oct-19 01:27 PM Spend a bit more for RG-8 and you are easily in several MW peak at hundreds of amps, as long as you can store enough charge to deliver the desired current. 09-Oct-19 01:31 PM i once build one with RG 213 was quite power full, some colleges did the same but with those power line cable at uni, just insane 09-Oct-19 01:31 PM Let's say you pulse charge that big coax to 500kv, into a matched 100 ohm load that's 5kA, so 2.5GW. Problem is the impedance. I'm building a much lower impedance driver that pulse charged with less voltage could give me 10GW 09-Oct-19 01:31 PM RG213 is great for this if you can get your hands on it 09-Oct-19 01:31 PM Can handle at least a couple hundred kv charging 09-Oct-19 01:33 PM ok for HAM Radio you often have allot of it around ;), i did only 85kV 09-Oct-19 01:33 PM getting the impedance down is an other problem 09-Oct-19 01:33 PM there are lower bounds witch are hard do beat 09-Oct-19 01:33 PM Yeah, you need a lot in parallel 09-Oct-19 01:33 PM What do you charge the coax with? Series-parallel marx? 09-Oct-19 01:33 PM That's where large flat strip line blumleins work best with 09-Oct-19 01:33 PM You can pulse charge them via cap bank, marx bank, pulsed air core transformer, etc 09-Oct-19 01:33 PM Very flexible 09-Oct-19 01:33 PM They can be DC charged of course, but fast pulse charging has advantages for higher voltages 09-Oct-19 01:34 PM Oh, on the note of pulsed air core transformers - if anyone wants a cheap, very high voltage, high current pulse source, look into soviet x-ray NDT machines 09-Oct-19 01:34 PM they sometimes pop up on eBay 09-Oct-19 01:34 PM up to 250kV, a good few mA 09-Oct-19 01:35 PM You can actually build them quite cheap and easy 09-Oct-19 01:36 PM you could, but it can be easier to just buy one if it's $100 09-Oct-19 01:37 PM Single turn wide primary, with either spiral wound or helical wound secondary. Benefit is much higher peak currents, and can go up to a few hundred kv in air, and with a bit of dilute copper sulfate, MV outputs with fast pulses 09-Oct-19 01:37 PM I'd rather build than buy lol 09-Oct-19 01:38 PM Dilute copper sulfate? What does that do? 09-Oct-19 01:38 PM For fast pulses, at extreme field gradients it helps relieve field enhancement stresses without conducting or breaking down 09-Oct-19 01:38 PM J.C. Martin pioneered the technique 09-Oct-19 01:40 PM Would something like that survive discharging in air continuously? 09-Oct-19 01:41 PM It wouldn't be a continuous discharge 09-Oct-19 01:41 PM yeah, but pulsing over and over 09-Oct-19 01:41 PM Yeah shouldn't be an issue if designed properly 09-Oct-19 01:42 PM would be cool to just build a demonstrator that shoves a 2-3MV discharge through the air 09-Oct-19 01:43 PM It wouldn't break down at the same length as a slow pulsed 2-3MV marx or van de graaf generator 09-Oct-19 01:44 PM how fast are we talking? 09-Oct-19 01:44 PM Nanosecond level, probably on the order of hundreds of ns 09-Oct-19 01:44 PM You can build fast marxes that are in that range, but you wouldn't see a fat, long arc like normal slow banks 09-Oct-19 01:44 PM But anyone who knows my rants on the subject knows that arcs are a waste lol 09-Oct-19 01:47 PM they also create much more refined pulse shape, you still have to tweak them 09-Oct-19 01:47 PM Arcs are a pretty waste 09-Oct-19 01:47 PM @GigaSquirrel you are going to get me going on the subject again lol 09-Oct-19 01:47 PM Yeah fast pulse transformers can be tricky to tweak. Really any of the fast stuff where square pulses are needed gets kind of into weird territory 09-Oct-19 01:53 PM Doing something right is all ways allot of work no matter what it is 09-Oct-19 02:25 PM Joined the server. 09-Oct-19 02:25 PM What is this place 09-Oct-19 02:25 PM Hello people 09-Oct-19 02:26 PM hiho @Jon 09-Oct-19 02:26 PM this place is where madness resides. or something like that 09-Oct-19 02:27 PM :o 09-Oct-19 02:27 PM mainly vacuum related stuff, also many other things 09-Oct-19 02:27 PM and yeah, we have a bot that censors everything that might possibly contain words that someone somewhere might find offensive. :-D 09-Oct-19 02:27 PM Vaccum related stuff? 09-Oct-19 02:27 PM So we talk about stuff where air is not present? 09-Oct-19 02:27 PM Or oxygen maybe I should say idk 09-Oct-19 02:28 PM we strive to get all gas molecules out of our chambers 09-Oct-19 02:28 PM with more or sometimes less success 09-Oct-19 02:28 PM and with different purposes 09-Oct-19 02:28 PM some to get images (electron microscope stuff), some to make chips ( @Nixie stuff), some to make tubes, some to try their luck at fusion 09-Oct-19 02:30 PM Suck-cess, @Pan Da 09-Oct-19 02:31 PM oh, and we have nixie, the one with the jokes even worse than mine. which is quite an achievement. 09-Oct-19 02:39 PM another medal for the nixie 09-Oct-19 02:42 PM you already had that one! 09-Oct-19 02:48 PM I can't wait until reprap starts selling "diy silicon fab" kits in 50 years time 09-Oct-19 03:27 PM Heh thats what I want to make feasible. 09-Oct-19 03:27 PM I think its quite do-able if we figure out all the right corners to cut 09-Oct-19 03:27 PM If Sam can figure out blueray laser lithography, and I can figure out if KOH could maybe just maybe work for an enchant. Then someone needs to figure out something other than SU-8 for the resist... 09-Oct-19 03:27 PM I need to get my hands on some SU-8 still but I need to be ready for it. 09-Oct-19 03:49 PM Sam didn't do a bluray laser litho 09-Oct-19 03:49 PM He used a DLP projector pointing backwards through a microscope 09-Oct-19 03:49 PM Did you watch and read his entire series? 09-Oct-19 03:49 PM He showed what resists you can use other than su8, also showed what you can do to etch 09-Oct-19 03:49 PM KOH probably will work, but with a cheap resist it's almost guaranteed to wash it off 09-Oct-19 04:05 PM I didn't see anything about resists other than SU-8 I remember him mentioning it briefly but using SU-8 himself. 09-Oct-19 04:05 PM Also did you not see his work with PS3 Blue-ray lasers and the driver board he designed and built? 09-Oct-19 04:05 PM He mentioned using it for Litho in the future. I am quite aware that he used a modified DLP projector through a microscope. 09-Oct-19 04:05 PM Just replaced the bulb with a high power UV LED and probably removed whatever color generation there was, whether it be a color wheel or LCD panel of some kind. 09-Oct-19 04:10 PM You can't really use a bluray laser for litho directly efficiently 09-Oct-19 04:10 PM You could probably draw, but projector is just as good 09-Oct-19 04:10 PM however, you have a SEM 09-Oct-19 04:10 PM you can do e-beam litho! 09-Oct-19 04:10 PM maskless AND stepless 09-Oct-19 04:10 PM a ton of materials act as e-beam resists 09-Oct-19 04:10 PM including regular UV resist 09-Oct-19 04:12 PM This is true. But I thought e-beam was almost harder due to how sharp it is. Its basically like trying to play a scratch off with a sewing needle vs a coin... 09-Oct-19 04:12 PM You'll spend forever just trying to get a solid infill of space. 09-Oct-19 04:12 PM I mean if your process is as good as the width of the beam then your golden I guess. Or if you don't care about rounded corners you could change the beam size I suppose to get a larger beam. Or I suppose have some process that automatically adjusts this. But either way it would be a lot of management of stuff. I suppose the same problem exists with a laser. 09-Oct-19 04:12 PM Not sure why you couldn't use a laser for litho. I think the idea was to use the lens assembly for local really fine detail movement then step the assembly. 09-Oct-19 04:12 PM It wouldn't have the same problems as DLP with uneven lighting/lens shifting problems/etc/etc. 09-Oct-19 04:17 PM You can just crank up the current and defocus to draw a fatter line 09-Oct-19 04:17 PM But why not let e-beam litho run? It's not like you're turning the handles through the process, you can just load a wafer into the SEM, pump it down in the evening, hit "go" and come back the next morning with a stepped, clean mask 09-Oct-19 04:17 PM That also doesn't expire because it's sitting under high vacuum in a cleanroom environment 09-Oct-19 04:17 PM At this point with DIY, sharper and tighter control = better, even if it means an order of magnitude slower 09-Oct-19 04:17 PM Sure, you can't manufacture dozens of dies per run with an e-beam system(unless you really hate your filament and focusing coils), but if you can guarantee high quality litho without fiddling with optics, I see it as a huge plus 09-Oct-19 04:32 PM Sure, for initial test runs and such. But its still a process to figure out/debug. And not really a feasible option for everyone if trying to make it more accessible. So it seems eh to put the effort into it. 09-Oct-19 04:33 PM Let's face it - anyone who wants to build chips at home is either in the US and can find a SEM within their budget, or outside the US and is unlikely to succeed due to a lack of parts 09-Oct-19 04:33 PM Excluding lucky finds 09-Oct-19 04:33 PM (our European friends, the Japanese auctions) 09-Oct-19 04:34 PM Well see thats just all the more reason to drive simpler processes that are more accessible. 09-Oct-19 04:34 PM I'd try e-beam just to prove that making chips is not a one-off venture like Sam's success, and that people can replicate it 09-Oct-19 04:34 PM DLP projectors, accessible. SU-8 not really, HF or some kind of RIE not really. 09-Oct-19 04:34 PM I mean Sam did it with a DLP though, even though he had an SEM. He did prove he could do e-beam but didn't use it for the chips. 09-Oct-19 04:34 PM I have to wonder why that is. 09-Oct-19 04:35 PM HF is accessible 09-Oct-19 04:35 PM it can be synthesized, if anything 09-Oct-19 04:35 PM But not really all that fun to handle and own... 09-Oct-19 04:35 PM but do you want HF? 09-Oct-19 04:35 PM yeah that's where I was going 09-Oct-19 04:35 PM Right that's the problem. 09-Oct-19 04:36 PM DLP lets you process things significantly faster 09-Oct-19 04:36 PM KOH behaves etching OK in certain directions/crystal orientations 09-Oct-19 04:36 PM but Sam is now doing e-beam 09-Oct-19 04:36 PM So you'd be limited in shapes and formations. for your SiO layers 09-Oct-19 04:36 PM Is he? for all his chips? I didn't realize he switched. 09-Oct-19 04:37 PM not for all, but from what I gather that's his next project 09-Oct-19 04:37 PM I know he did it as a test but didn't know he made any chips with them. 09-Oct-19 04:37 PM what with the beam blanker and DAC 09-Oct-19 04:37 PM Ah ok 09-Oct-19 04:37 PM Right. 09-Oct-19 04:37 PM Either way. I have two SEMs, if I can get one going to use for imaging and one for e-beam litho it would probably work out ok. 09-Oct-19 04:37 PM The one SEM I have does have a large secondary chamber 09-Oct-19 04:37 PM I can basically get a whole wafer in there 09-Oct-19 04:38 PM you don't need a separate SEM for litho, or anything else 09-Oct-19 04:38 PM I think it can actually handle up to a 6" wafer 09-Oct-19 04:38 PM the hard part is modifying it to blank the beam 09-Oct-19 04:38 PM I know 09-Oct-19 04:38 PM I was just saying I have two, I can use both at the same time theoretically. I have the power and cooling capacity. 09-Oct-19 04:38 PM Either way. I'll figure something out. My next step is to get my hands on some resist of some type. 09-Oct-19 04:38 PM I have wafers. 09-Oct-19 04:38 PM KOH is easy 09-Oct-19 04:39 PM buy some liquid UV resist 09-Oct-19 04:39 PM and build a spinner to play with thickness 09-Oct-19 04:40 PM Thats fairly ambiguous? 09-Oct-19 04:40 PM yep, there's a huge variety 09-Oct-19 04:40 PM I'd buy a few 09-Oct-19 04:40 PM I have a feeling that if you don't get the KOH too hot and do it gently, good UV resist will survive 09-Oct-19 04:41 PM Right. 09-Oct-19 04:41 PM Either way, so long as the resist is thick enough and etches at a similar rate to the silicon it doesn't matter too much. 09-Oct-19 04:42 PM but not too thick to get washed away 09-Oct-19 04:42 PM I've had experience with some resists that were ridiculously stainy and sticky 09-Oct-19 04:43 PM hm 09-Oct-19 04:43 PM the nastiest in that regard will probably work best 09-Oct-19 08:33 PM The only thing with e-beam is that getting your hands on a SEM is plainly difficult. I don't have much faith in my e-beam drawer either, XD 09-Oct-19 08:33 PM Good thing with e-beam is that the resist is not too expensive (I think it was 1€ per ml, for a 250ml bottle or so) But maybe we could persuade the producer to actually sell it in smaller amounts (same volume, but in many small bottles instead of a big one). 09-Oct-19 08:52 PM you don't necessarily need e-beam resist 09-Oct-19 08:52 PM you can also probably make your own 09-Oct-19 08:52 PM a common e-beam resist is PMMA dissolved in chlorobenzene or [ethyl lactate + 1-methoxy-2-propyl acetate] 09-Oct-19 08:52 PM there's also styrene acrylates in anisole 09-Oct-19 08:52 PM http://www.allresist.com/faq-ebeamresists-compositing/ 09-Oct-19 08:52 PM this page is really informative 09-Oct-19 08:52 PM and almost all of these are replicable at home 09-Oct-19 08:52 PM PMMA is very sensitive to electron beams in thin layers 09-Oct-19 08:52 PM even the regular plexiglas kind 09-Oct-19 09:37 PM Hrm 09-Oct-19 09:37 PM I thought PMMA was inferior as a resist but I suppose it depends on application and grade of the PMMA, aka the molecular mass I suppose? 09-Oct-19 09:50 PM yeah that page talks about the molecular mass 09-Oct-19 10:51 PM @Applied_Ion not gonna beat you to anything, as I am not even sure I can get my hands of those cables 09-Oct-19 10:51 PM plus I'm working full time atm 09-Oct-19 10:51 PM so there's that 09-Oct-19 10:51 PM but I'm currently testing those cables if they're up to spec, after delivery to my company 09-Oct-19 10:51 PM so I get to work with 20 cm pieces 09-Oct-19 11:23 PM @Deleted User @Conmega you can definitely do litho with laser, I've done it, and plenty of universities have these line of machines https://www.himt.de/index.php/direct-write-lasers.html 09-Oct-19 11:23 PM You get a much better beam spot than DLP, due to the shorter working distance and NA 09-Oct-19 11:23 PM Trouble is registration of features across the substrate puts more pressure on having good mechanical stability of your stage, and good encoders to keep track of where you are as well as accounting for mechanical flaws like backlash 09-Oct-19 11:23 PM PMMA in anisole is one of the best resolution and easiest e-beam or FIB resists, the reason others exist is to reduce the beam dosage required for better throughput or for steeper/higher aspect ratio walls 09-Oct-19 11:23 PM Also, you need a spin coater, which you could build from a hobby airplane motor and a custom vacuum chuck/spindle 09-Oct-19 11:29 PM @nmz787 which is why I said it's not very feasible at the DIY level 09-Oct-19 11:29 PM you're either limited by the precise control of the bluray writer stage(so a few mm in each direction max), or you have to build something very stable and complicated 10-Oct-19 12:07 AM Yeah but a decent stage or encoders and a good computer algorithm is WAYY less expensive and complicated from a DIY standpoint than SEM and all the vacuum knowledge 10-Oct-19 12:07 AM If the market is a kit for hobbyists anyway 10-Oct-19 12:07 AM That said, my $100 405nm laser etcher does hust fine for circuit board photolithography, and I was planning for it to work fine for submillimeter microfluidic interfaces for nanofluidics that I make with e-beam/FIB 10-Oct-19 12:07 AM The latter are a lot slower processing times, and if contracting out the work, a lot more expensive too, so a hybrid approach is what I've been planning to take 10-Oct-19 12:07 AM This is the newer version of the one https://www.amazon.com/Engraver-Resolution-Engraving-Bluetooth-Protective/dp/B073TRJDPS/ref=asc_df_B073TRJDPS/ 10-Oct-19 12:07 AM This is the bluray drive PCB i got to upgrade to smaller spot size http://www.diyouware.com/DiyoPCB-MKI 10-Oct-19 12:07 AM My plan was to use an offset microscope video camera to watch a set of nice grid lines and use machine vision like openCV to calibrate out backlash and do route planning 10-Oct-19 12:22 AM Oh yeah, sub-mm is really easy 10-Oct-19 12:22 AM But doing something with chips at a repeatable accuracy and large process( -> large sizes)? 10-Oct-19 12:22 AM I don't know 10-Oct-19 12:22 AM This is definitely sub-micron encoder region 10-Oct-19 12:22 AM Which, while not very expensive(magnetic of course, good luck getting cheap sub-micron glass scales), it's also not very cheap 10-Oct-19 12:22 AM In some cases it's also just a better option to get a SEM(you get a SEM!), since the old ones are available easily if you're in the right places 10-Oct-19 12:22 AM but if we're talking about strictly a DIY kit and not the common sense/practicality route, then it probably is cheap enough to go with a couple voice coil magnetic actuators with magnetic encoders 10-Oct-19 12:51 AM anisol with pmma is nice 10-Oct-19 12:51 AM smells good 10-Oct-19 12:51 AM and doesnt give cancer 10-Oct-19 01:09 AM I foubd it was easier for me to get chloroform (and a fume hood) 10-Oct-19 01:09 AM Getting a SEM in my country is just unfeasible. (Spain) 10-Oct-19 01:09 AM (nor a wire bonder, I will have to make my own too) 10-Oct-19 02:13 AM hm yeah 10-Oct-19 03:57 AM (well, I have had to make everything... ) 10-Oct-19 04:25 AM it like cooking 10-Oct-19 07:45 AM XDDDDDDDDDD 10-Oct-19 08:37 AM I would think for the lasers you'd want to use mirrors more than a stage, just like SLA 3D printing works. But either way the idea of getting it into a cheaper friendlier environment isn't to make microprocessors at home right away. Its more to get it into people's hands to drive interest to it. Prove it CAN be done and let more people join the crusade and figure out how to refine it further. Imagine allowing a student to make a few transistor chip right there in the lab though... It allows for the student to learn the process. What changing variables like gate oxide thickness does. Etc... its a learning tool. Now obviously I want to push myself at home using e-Beam litho and such too. And I will. But for the goal of DIY being able to use the process to make a very simple large scale chip at home would be awesome. On the order of 5 transistors or something on a little chip. Not like hundreds off the bat. 10-Oct-19 08:37 AM But either way this is a big group oriented project. Only problem is the group consists of people all over the world, different tool sets, and different accesses to materials. So right now collaboration isn't quite as easy as it should be. But this discord and other avenues are places to start sharing info :) 10-Oct-19 08:37 AM And ideas of-course. 10-Oct-19 02:06 PM @GigaSquirrel Now that I think about it (regarding power cable) I do recall that a year a go an IRC associate got a contract to dredge up couple of km of underwater power cable due reasons unknown the me. Interesting dude. IIRC bought a used warship and retrofitted it with self built equipment for rising and laying cable. 10-Oct-19 02:06 PM oh damn that sounds fun 10-Oct-19 02:09 PM He had problems disposing of the used cable and made a machine to cut it to 4m long pieces for disposal 10-Oct-19 02:09 PM @Nixie This dude in portucal managed to find a a wirebonder https://www.qsl.net/ct1dmk/wire_bonding.pdf 10-Oct-19 02:09 PM https://www.qsl.net/ct1dmk/wbond_m.html 10-Oct-19 02:18 PM Extremely well said, @Conmega 10-Oct-19 02:18 PM Good for him! 10-Oct-19 10:45 PM Anybody have experience with sputtering or evap coating a thin layer of aluminum of thin steel or nickel? Need to make a modern equivelant of aliron which i do not believe was clad. 10-Oct-19 10:45 PM If it was of course I’m screwed cause like hell am I going to figure out diy garage cladding! Hahaha 11-Oct-19 08:33 AM Hrm I mean sputtering is generally a smaller process limited in what materials you use because they can get real hot and you end up needing fancy HV power sources. But EVAP coating is scaled quite large sometimes, although you end up needing tons of power as-well for all the metal melting. But that is at-least easy to get, simple transformer down from mains to a few volts at a LOT of amps. You could probably use a few boats of metal in a large chamber to coat a large piece. 11-Oct-19 08:33 AM But this only produces a very thin layer of material. You can run them for a long time and it should build the layer up. But I don't know what the application of an aliron will need for thickness of a certain type of metal. 11-Oct-19 08:33 AM I assume you mean putting aluminum on steel or nickle which should be do-able? Steel or nickel on aluminum may be do-able as-well but I don't know how easy it is to evaporate steel haha. 11-Oct-19 09:03 AM Hm...I thought sputtering was a "cold" process, and it had less limits than thermal because it will sputter everything, but not decompose it (like ITO coatings, for example). And the power supply is just a microwave oven with no mods (for the low voltage/high amperage, you can mod it like a spot welder). BUT, for aluminium, evap should work good too. 11-Oct-19 09:03 AM What s an "aliron", btw?? 11-Oct-19 09:05 AM aerospace stuff. planes/rockets I'd assume 11-Oct-19 09:05 AM Not sure why the cladding is needed, I'd always assumed they just either used solid steel or aluminum 11-Oct-19 09:10 AM Ah, like those explosive welded plates that require one metal on the inside of the container for protection and other on the outside for mechanical resistance? 11-Oct-19 09:21 AM Possibly! 11-Oct-19 10:21 AM @Nixie RF sputtering will sputter everything when mixed with DC sputtering 11-Oct-19 10:48 AM In this particular application I want as thin of a coating of aluminum as possible but still be a good bond and opaque on a steel or nickel substrate. This is for tube applications. It was produced in multi ply with an additional layer of copper for thermal properties by TExas Instruments by the cladding process and then rolled to thickness. It was discovered that the aluminum coating was doing most of the work and was changed to just the aluminum on steel and AlIron was born. When heated in a vacuum thin aluminum films turn grey and they get most of the way to a decent black body radiator without many of the drawbacks of carbon coatings or graphite anodes. They give up their adsorbed gasses much more radially. It has to be thin though so the conversion takes place and melted aluminum does not run all over. The chemical process that converts the aluminum to grey takes some time. 11-Oct-19 10:49 AM You should be able to sputter aluminium with an RF coater that way 11-Oct-19 10:56 AM You don't need an RF coater for that! A simple DC sputer is good enough. 11-Oct-19 10:56 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/1570816791756-727331189-B35AF.jpg 11-Oct-19 10:56 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/15708168737441176369131-C8985.jpg 11-Oct-19 11:05 AM I'd use RF for uniformity and thickness control 11-Oct-19 11:06 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_20191011-200552-450AD.png 11-Oct-19 11:06 AM that's a rough coat 11-Oct-19 11:06 AM Not gonna argue with that. 11-Oct-19 11:06 AM Just getting hold of the equipment for rf sputtering can be a bit more difficult. 11-Oct-19 11:07 AM it's still amazing that you can do that with a MOT and a high end jam jar 11-Oct-19 11:10 AM If t works, it works. 11-Oct-19 11:10 AM Not sure how to interpret the "high end jam jar" thing, though. 11-Oct-19 11:16 AM I'm oversimplifying 11-Oct-19 12:03 PM https://i.spirit.re/jnSCd.png 11-Oct-19 12:03 PM Just a quick PSA 11-Oct-19 12:03 PM If anyone is looking at buying STM32F103 blue pills from China - beware, the sellers started unloading totally fake, half-dead chips! 11-Oct-19 12:03 PM On the left is what I pulled from a blue pill I received, on the right is a brand new f103 from ST. 11-Oct-19 12:03 PM Buy the black-colored version of the board. Those seem to be genuine too. 11-Oct-19 12:20 PM Ok very good to know 11-Oct-19 12:20 PM I just thought at most they ware re-labeled GD32F103's, not just crap. 11-Oct-19 12:44 PM GD32s are genuine chips that are "compatible" with STM32 11-Oct-19 12:44 PM but not quite 11-Oct-19 12:44 PM CS32 are just plain crappy clones 11-Oct-19 12:44 PM GD32s are also "red pills" and cost a fair bit more 11-Oct-19 01:35 PM Who manufactures CS32? 11-Oct-19 02:45 PM Good to know! 11-Oct-19 04:37 PM Unfortunately something like this was inevitable in the price war of these cheap boards. Good to know people are at-least aware and spreading the info. 11-Oct-19 06:13 PM @rfs "CKS" or "China Key System" 11-Oct-19 06:13 PM ty 11-Oct-19 06:13 PM So they tried to do a GigaDevice with STM32 compability but could not? 11-Oct-19 06:19 PM Nope, it's a straight up stm32f103 clone 11-Oct-19 06:19 PM at least giga implemented their own core and their own peripherals 11-Oct-19 06:34 PM ok 11-Oct-19 06:34 PM Like copy of the silicon, not just a functional clone like GD32 series? 11-Oct-19 06:34 PM IIRC GD32 is code and binary compatible with the corresponding STM32 parts 11-Oct-19 06:34 PM even their IDE and some libraries ware 1:1 from ST 11-Oct-19 06:53 PM the GD32 is supposed to be code and binary compatible but it's not quite compatible, a few minor quirks in terms of timing and register high/low order 11-Oct-19 06:53 PM the cs32 is a bad silicon clone 11-Oct-19 06:53 PM confirmed by ST that it's not licensed 11-Oct-19 06:59 PM ok 11-Oct-19 08:28 PM An update on the Hositrad ordeal: They still want me to pay for it. They're offering to give me a whopping 50% discount off the 200 euro shipping cost for a 1.2kg box not even halfway across Europe, with less than 200 eur of parts inside! 11-Oct-19 08:28 PM I think I'm just going to stop replying instead of trying to explain to them that they slammed me with a ton of totally unwelcome import charges and its purposes being questioned(from a legal point of view) when DHL Express threw it at our customs. I advise to not deal with this company. The parts are nice quality and all, but if this is how they behave after making a mistake... 11-Oct-19 08:28 PM On another note - glass annealing oven parts started arriving, and the evacuation tubes for the nixies are here! The second chuck for the metal->glass lathe conversion addon is almost here too, I'll make a short project video on that, since some people might find it useful. 12-Oct-19 12:27 AM nice! 12-Oct-19 12:27 AM (on the glass things) 13-Oct-19 11:18 PM moin! 13-Oct-19 11:19 PM So big heads up here 13-Oct-19 11:19 PM You can see the first exclusive concept reveal for EXEDA tomorrow livestreamed from the open source cubesat workshop 13-Oct-19 11:20 PM https://media.tenor.com/images/0b3e8f533ef1ad6057a2fa384c87ba8b/tenor.gif 13-Oct-19 11:20 PM I have a pretty full schedule this week, will you record it? 13-Oct-19 11:27 PM I think it's recorded here 13-Oct-19 11:27 PM On YouTube at least I think 13-Oct-19 11:28 PM yay! 13-Oct-19 11:28 PM so excited 13-Oct-19 11:28 PM This is not the version I'm building, but a look at the conflat compatible system 13-Oct-19 11:28 PM will you finally reveal the topology? 13-Oct-19 11:29 PM A conceptual peak, then cover it more fully on twitter 13-Oct-19 11:29 PM yay² 14-Oct-19 11:32 PM for what is EXEDA the acronym? 14-Oct-19 11:37 PM That's what you will find out lol 14-Oct-19 11:37 PM This is a very basic top level overview, I will do much more in depth details on twitter after 14-Oct-19 11:46 PM I just want to know what topology it is, this has been driving me a bit crazy xD 14-Oct-19 11:46 PM I don't have time to go over the driver, just the accelerator 14-Oct-19 11:46 PM Again this is a bit different than what I'm building, but serves as the basis to scale and adapt it to any conflat standard 14-Oct-19 11:47 PM maybe topology isn't the right word? I wanna know if it's an induction linac, betatron, RF cavity linac etc 14-Oct-19 11:47 PM In some sense, this is the true EXEDA 14-Oct-19 11:47 PM None of the above lol 14-Oct-19 11:47 PM Topology is correct wording 14-Oct-19 11:47 PM Like I said, you may be disappointed how simple it is 14-Oct-19 11:47 PM But its versatility is extraordinary, unlike any other type of accelerator 14-Oct-19 11:47 PM Beauty and functionality in simplicity 14-Oct-19 11:47 PM Perhaps this isn't the right venue for unveiling such a system, but it relates to radiation dosing of space electronics at least for one of the many things that can be done with it 14-Oct-19 11:47 PM The first part of the talk will cover a micro tvac, since I was requested to do a tvac one 14-Oct-19 11:47 PM So I got 12 minutes to cover 2 complex systems lol 14-Oct-19 11:52 PM yeah I figured it's none of the above :D 14-Oct-19 11:52 PM It's so much simpler lol 14-Oct-19 11:52 PM But it can be used as an injector for many other types 14-Oct-19 11:52 PM Though the big systems are usually standalone 14-Oct-19 11:55 PM https://media.tenor.com/images/3b91159bcf42b1883cc907d83f8b34e5/tenor.gif 14-Oct-19 11:56 PM By big, we are talking the TW class monsters that constitute the most powerful accelerators ever built. But they can be compact and fit on the table too. And the systems they can drive can scale accordingly. New untouched particle beam physics just waiting to be realized at the amateur level. 14-Oct-19 11:57 PM you goddamn tease :D 14-Oct-19 11:58 PM I've gotta try building some hype lol 14-Oct-19 11:58 PM the hype is real! 15-Oct-19 12:01 AM Well, maybe for like the 3 people actually interested in it lol 15-Oct-19 12:01 AM But let's just say it will touch many areas of the diy community. Rf, xray, laser, accelerators, radiation, semiconductor - the possibilities are endless. No home built DC or cyclotron accelerator would ever be able to match it's versatility and functionality for equivalent cost and complexity that could be achieved at home 15-Oct-19 12:01 AM Get ready for one hell of an info dump soon after the conference on the possibilities lol 15-Oct-19 12:05 AM I hope I don't miss it, got a lot to do at work :/ 15-Oct-19 12:05 AM It's honestly going to be super short lol. I'll be doing full detailed releases on Twitter 15-Oct-19 12:08 AM @GigaSquirrel contain yourself 15-Oct-19 12:10 AM never! 15-Oct-19 12:16 AM Lol 15-Oct-19 02:44 AM is it like a wakefield accelerator? 15-Oct-19 02:47 AM my current guess is lots of pulseforming for very high voltage and then just a cathode and anode with hole on it for acceleration 15-Oct-19 03:27 AM EXEDA-MEVI is the closest to Wakefield, buy not quite 15-Oct-19 03:27 AM I doubt anyone would guess the type MEVI is lol, its really arcane. @GigaSquirrel is getting hot lol 15-Oct-19 03:31 AM :D 15-Oct-19 03:31 AM so hot I start emitting a cloud of free electrons? 15-Oct-19 03:32 AM Yes, but not with heat lol 15-Oct-19 03:52 AM Extremely hot, Low pressure alkaline gas (or maybe RF-exited plasma?), pulsed high energy E-beam pump (MEgaVolt Injection?) injected at acoustic chamber resonance and small pulsed proton gun fed from same PFN but with some physical delay length? IDK, that's pretty damn close to a regular wakefield. Forgive me if this is way off, i'm rather new to the field. 15-Oct-19 03:55 AM Nope. Way, way simpler 15-Oct-19 03:55 AM So simple it's stupid, yet no one really knows about this type anymore 15-Oct-19 03:55 AM Well, MEVI requires EXEDA to run, so there is an injector initially, but its quite unconventional 15-Oct-19 03:55 AM It's not actually Wakefield however 15-Oct-19 03:55 AM Loosely related, but predates Wakefield 15-Oct-19 09:41 AM I propose we just give @Applied_Ion a wack between all of us until he splurts out all the details. The fact that he will reveal it soon is just details. 15-Oct-19 09:45 AM Well I just presented a brief overview live of both EXEDA and EXEDA-MEVI lol 15-Oct-19 09:45 AM I will start posting details now though lol 15-Oct-19 09:54 AM nice 15-Oct-19 09:54 AM would build 15-Oct-19 09:54 AM 10/10 15-Oct-19 09:56 AM You catch presentation? 15-Oct-19 10:13 AM Joined the server. 15-Oct-19 10:28 AM @Applied_Ion I see nothing re details on your Twitter 15-Oct-19 10:31 AM Yeah, I haven't released it on twitter yet lol 15-Oct-19 10:31 AM I can't do it like now 15-Oct-19 10:31 AM It will be released soon, but I can't physically do it at the moment lol 15-Oct-19 10:52 AM Joined the server. 15-Oct-19 10:54 AM @Applied_Ion Linklinklink! 15-Oct-19 11:09 AM Link? 15-Oct-19 11:09 AM Link for talk is on my twitter lol 15-Oct-19 11:09 AM I'm last 20 minutes if it's uploaded to youtube 15-Oct-19 11:09 AM I'll also share presentation slides too 15-Oct-19 11:43 AM @Applied_Ion last 20 mins of the YouTube link you posted yesterday is software 15-Oct-19 11:43 AM https://youtu.be/ushHJOwnaB4 15-Oct-19 11:44 AM Yesterday's was software mostly. Not sure if today's is up yet 15-Oct-19 11:44 AM Idk I don't control uploads lol 15-Oct-19 11:45 AM I dont see any other links on your Twitter 15-Oct-19 11:46 AM From today? I posted today, but it might not be uploaded yet. It's a long recording, probably take quite a while to process 15-Oct-19 11:48 AM I only see tweets from 11 hours ago for you 15-Oct-19 11:48 AM But i think i found the video on their YouTube 15-Oct-19 11:48 AM Yeah its probably on their channel if anything 15-Oct-19 11:49 AM https://youtu.be/O5b30xv8Sfo 15-Oct-19 11:49 AM Only seems to work on the YouTube app 15-Oct-19 11:49 AM Starts at -36:00 15-Oct-19 12:28 PM Dyno seems to be deleting @Shiz's introduction 15-Oct-19 12:29 PM I'm not writing that awkward wall of text again 15-Oct-19 12:29 PM Welcome anyway! 15-Oct-19 12:29 PM thank you! 15-Oct-19 12:29 PM Joined the server. 15-Oct-19 12:30 PM and there's the third collaborator :p 15-Oct-19 01:00 PM The world of nerds is slowly acquiring SEMs 15-Oct-19 01:00 PM (some particular nerds acquire TEMs and FIBs as well) 15-Oct-19 01:07 PM we almost acquired a questionable-state TEM for 50$ 15-Oct-19 01:12 PM you should have! 15-Oct-19 01:12 PM they make for terrible x-ray tubes. 15-Oct-19 01:14 PM Joined the server. 15-Oct-19 02:03 PM Welcome Shiz, pbx, and PeterC! 15-Oct-19 02:33 PM Welcome all! 15-Oct-19 02:33 PM @Shiz is probably unkowingly writing a banned word. For example catas*trophic could be banned because of the obvious word included. 15-Oct-19 02:36 PM yeah, Dyno's censoring is quite crаppy 15-Oct-19 02:36 PM side note: catastrophic has one s 15-Oct-19 02:53 PM yeah, I did 15-Oct-19 03:14 PM Why don't we just disable the censorship and ban anyone who goes against a code of decency? 15-Oct-19 03:14 PM That censorship has hit me too before, in really stupid ways 15-Oct-19 03:16 PM well keeping a long story from the intro short, I've been mostly doing software, just getting into hardware analysis & hacking stuff and @pbx/peterbjornx and @PeterC and me started a project of obtaining a SEM for our hackerspace :> 15-Oct-19 03:23 PM Awesome! If I had a hackerspace near me I would have totally set one of the SEMs I have up there... But alas, nothing like that decent around here. 15-Oct-19 03:23 PM This is a good place to be for help and assistance with that kind of stuff though :) 15-Oct-19 03:23 PM Also where are you guys based out of? US? Europe? Its fairly diverse here heh. 15-Oct-19 03:45 PM ah right, whoops 15-Oct-19 03:45 PM europe, the netherlands 15-Oct-19 03:45 PM no hackerspaces around here with a SEM yet to my knowledge, so time to make a public SEM available! 15-Oct-19 03:49 PM And a public person to teach people how to use the SEM! :P 15-Oct-19 03:51 PM yes, very much 15-Oct-19 03:51 PM nobody will be using it without training 15-Oct-19 05:38 PM In my experience using a microscope is almost self explanatory, but being sure you're not going to break it, and how to keep it running, is where things get scary! 15-Oct-19 05:50 PM Well depending on which make you get it can be self explanatory or not really heh... Also generally you need to perform an alignment every time you run a sample through incase someone else did something weird. And there is also training required with sample prep and such. 15-Oct-19 05:50 PM Also yea not breaking things is important, proper filament saturation/etc. 15-Oct-19 08:43 PM ( @nmz787 the owner of the channel can bring people from work and other sensible people (relatively younglings) in here, so he has deemed that the channel better be made Family frendly at all times. His Discord, His Rules, basically. ) 15-Oct-19 08:46 PM Who is that anyway? 15-Oct-19 08:46 PM I'm just asking since i dont really know the history of this room... Never even used discord before hearing of this chatroom 15-Oct-19 09:01 PM That would be Adam McCombs, Electron Microscopy Wizard/Magician. 15-Oct-19 09:07 PM Oh, makes sense ;) 16-Oct-19 12:27 AM worstSEMmel 16-Oct-19 12:58 AM the best SEM instructor for your hacker space is martin SEMmelrogge 17-Oct-19 07:30 AM https://www.foodengineeringmag.com/articles/98504-vacuummicrowave-drying-technology-supports-food-cannabis 17-Oct-19 12:41 PM That article really looks like an advertisement 17-Oct-19 12:44 PM Quick question for those who have worked with second hand residual gas analyzers... How critical is the bit of ceramic insulation towards the tip on the left here: https://i.ebayimg.com/images/g/n5sAAOSw~c1dXZaw/s-l1600.jpg 17-Oct-19 12:44 PM I have seen quite a few of these come up cheap with those damaged just a bit like that or about 8mm down or so. Just so its no-longer insulating past the round end. 17-Oct-19 12:44 PM Like would this be OK? 17-Oct-19 12:44 PM https://i.ebayimg.com/images/g/7kMAAOSwzq5dRfBC/s-l1600.jpg 17-Oct-19 12:44 PM Just slightly more damaged. 17-Oct-19 12:44 PM Also on a side question, is that bit of ceramic repairable with anything known on the market if it is critical? 17-Oct-19 12:44 PM Going to nab that one in the second photo there if that bit of insulation missing isn't superbly critical. 17-Oct-19 12:44 PM Price is super right. 17-Oct-19 12:44 PM I'd assume its not since the connector on the tip is bulbous and near to that plate anyway... 17-Oct-19 12:44 PM But figured I'd ask the hivemind before spending money. 17-Oct-19 12:54 PM given the large physical size of the nubs, I don't think it matters much 17-Oct-19 12:54 PM I think the ceramic is there to prevent contact with the other things on the left, where it's not broken 17-Oct-19 12:55 PM That's what I was thinking :) 17-Oct-19 12:55 PM Thing is literally less than 200 bucks shipped so I think considering its not completely smashed in and it looks clean I will probably go for it this afternoon when I get home. 17-Oct-19 12:55 PM Worst case I have something to take apart and learn about and I get an electrical feedthrough I guess. 17-Oct-19 01:00 PM I need to find a good supplier of ceramic for these projects 17-Oct-19 01:00 PM yea... ceramic insulators like that would be cool to have a source for! 17-Oct-19 01:00 PM I bet you can find stuff on aliexpress 17-Oct-19 01:00 PM dead RGAs are a nice source of UHV HV feedthroughs 17-Oct-19 01:00 PM not often you can find UHV and HV 17-Oct-19 01:01 PM heh yea 17-Oct-19 01:01 PM I mean I hope this RGA WORKS 17-Oct-19 01:01 PM but they do have quite a few that are smashed beyond want... 17-Oct-19 01:02 PM I wonder how they end up in this condition 17-Oct-19 01:02 PM I mean you can find these if you look but I am not linking them because... yea... 17-Oct-19 01:02 PM I want one and I have a friend who will want one. 17-Oct-19 01:02 PM After that I will link the guy selling them. 17-Oct-19 01:02 PM I think these are field pulls... 17-Oct-19 01:02 PM I think I know the guy you're talking about 17-Oct-19 01:02 PM But you can have them 17-Oct-19 01:02 PM Yea probably... 17-Oct-19 01:02 PM They have been up for months... 17-Oct-19 01:02 PM I mean its been fair game for those looking haha 17-Oct-19 01:02 PM like two have sold I think? 17-Oct-19 01:03 PM If "field pull" literally means "pulled out from a field" then it's probably right 17-Oct-19 01:03 PM But honestly I haven't had the money and I've been waiting to see if maybe cheaper offers can be made if we let them sit for awhile. 17-Oct-19 01:03 PM lmao 17-Oct-19 01:03 PM These are clean enough they haven't sit on a shelf disconnected for long 17-Oct-19 01:03 PM and its unlikely that they all just failed a similar timeframe... 17-Oct-19 01:03 PM I have a feeling a line got disassembled or upgraded possibly 17-Oct-19 01:03 PM and they are just selling off what they had as parts stock and what was installed 17-Oct-19 01:03 PM Would make some sense. 17-Oct-19 01:05 PM Some of them look rusted to death 17-Oct-19 01:05 PM The stainless parts are shiny, but the non-stainless parts are red dust 17-Oct-19 02:04 PM must be a different seller then? these don't have a spec of rust 17-Oct-19 02:04 PM unless if the photos are wrong... which then even if its parts or not working that's terms for a return 17-Oct-19 02:04 PM I see one for $270 OBO that looks pretty good, no rust 17-Oct-19 02:04 PM I got one for 180 shipped just now 17-Oct-19 02:04 PM they had one a bit cheaper I made an offer on 17-Oct-19 02:04 PM the 270 is the same seller I think 17-Oct-19 02:04 PM https://www.ebay.com/itm/LEYBOLD-INFICON-TRANSPECTOR-TSP-TH100-6185-RESIDUAL-GAS-ANALYZER-T7-D14/153612833622 17-Oct-19 02:04 PM looks like they have a few 17-Oct-19 02:04 PM yea same seller 17-Oct-19 02:04 PM they have some that are too beaten up 17-Oct-19 02:04 PM some are OK 17-Oct-19 02:04 PM https://www.ebay.com/itm/LEYBOLD-INFICON-TRANSPECTOR-TSP-TH100-6939-RESIDUAL-GAS-ANALYZER-T7-D14/163803475171 17-Oct-19 02:04 PM This is what I got 17-Oct-19 02:06 PM I think I paid $50 for a power supply for mine 17-Oct-19 02:07 PM its just 48V DC? 17-Oct-19 02:07 PM https://www.ebay.com/itm/Computer-Products-Power-Supply-Leybold-Inficon-RGA-720164-23-CL40-7624I-24V/123750789107 17-Oct-19 02:08 PM I mean I'll just make a supply probably... 17-Oct-19 02:08 PM $52 shipped 17-Oct-19 02:08 PM unless I can find one of those for cheap 17-Oct-19 02:08 PM https://www.ebay.com/itm/LEYBOLD-INFICON-TRANSPECTOR-TSP-TH100-5362-RESIDUAL-GAS-ANALYZER-T7-D14/153612916247 17-Oct-19 02:08 PM Here is one from that seller without the 2.75" extension 17-Oct-19 02:08 PM so you can see how it looks 17-Oct-19 02:08 PM I got my RGA for $250 shipped 17-Oct-19 02:09 PM But eh here in #swap-meet 17-Oct-19 02:09 PM https://www.ebay.com/itm/LEYBOLD-INFICON-TSP-TC100-TRANSPECTOR-RESIDUAL-GAS-ANALYZER/264411385594 17-Oct-19 02:09 PM The guy has like 12 of these for 270 make offer 17-Oct-19 02:09 PM well, it's already been swapped 17-Oct-19 02:09 PM ah one of those shorter ones 17-Oct-19 02:10 PM looks like mine is TC100, yours TH100 17-Oct-19 02:10 PM maybe a difference in AMU resolution or something? 17-Oct-19 02:11 PM That and also yours is shorter... but there are stubby ones that I think work on a different principle and aren't as good 17-Oct-19 02:11 PM the one you got is like... in-between... 17-Oct-19 02:12 PM what's your email, I can forward the manual I received 17-Oct-19 02:12 PM So I dunno whats different. 17-Oct-19 02:12 PM Oh cool, leme DM you 17-Oct-19 02:12 PM I was thinking less pathlength, less ability to get resolution 17-Oct-19 02:12 PM pmuch, something like that 17-Oct-19 02:12 PM I just tried to keep an eye out for the long ones 17-Oct-19 02:27 PM I reckon if one of them works, all of them will @Conmega 17-Oct-19 02:27 PM so if you can get yours running, I'd just buy all of his RGAs for a low price in bulk 17-Oct-19 02:27 PM it'd make nice packages for hobbyists 17-Oct-19 02:28 PM Well some of them have some damage on the ends... 17-Oct-19 02:28 PM but if reasonably repairable I suppose yea probably worth doing. 17-Oct-19 02:28 PM Could get a test rig setup with some really pure argon to calibrate them 17-Oct-19 02:29 PM there's those argon dispenser things 17-Oct-19 02:29 PM with a specified flow rate and purity 17-Oct-19 02:29 PM yup 17-Oct-19 02:30 PM I wonder why a lot of the RGAs are sold... well, without the RGA itself 17-Oct-19 02:30 PM But yea don't just buy one... 17-Oct-19 02:30 PM because 17-Oct-19 02:30 PM https://i.ebayimg.com/images/g/~A0AAOSwfD5dVIgz/s-l1600.jpg 17-Oct-19 02:30 PM because people just unplug things off big chambers 17-Oct-19 02:30 PM bolts are hard 17-Oct-19 02:30 PM that controller just unplugs off the back of the RGA itself 17-Oct-19 02:30 PM also, re: your ceramic problem 17-Oct-19 02:30 PM https://i.spirit.re/lXQNF.png 17-Oct-19 02:30 PM from another ebay listing 17-Oct-19 02:30 PM these ones have the ceramic end all the way even before the final plate 17-Oct-19 02:30 PM I think you're good 17-Oct-19 02:31 PM kewl 17-Oct-19 02:31 PM but yea some of these are totally beat, some are just bent though 17-Oct-19 02:32 PM step 1: remove controller step 2: apply sledgehammer to the bit that doesn't unplug 17-Oct-19 02:32 PM lol 17-Oct-19 02:32 PM yea scrappers are real smart people 17-Oct-19 02:32 PM difference between like 300 bucks and 0 dollars 17-Oct-19 02:33 PM I want an international scrapper licensing board 17-Oct-19 02:33 PM And to make it illegal to do scrapping without showing the presence of brains 17-Oct-19 02:33 PM but that could also result in a total lack of too good to be true deals... 17-Oct-19 02:33 PM lmao 17-Oct-19 02:33 PM Honestly... It doesn't upset me more that I don't get a good deal... I am most upset that things are just not freaking being re-used 17-Oct-19 02:35 PM reused by us! 17-Oct-19 02:35 PM its like the most crucial part of Reduce Reuse Recycle!!! 17-Oct-19 02:35 PM I wana see all the 1um silicon production lines in all the basements! 17-Oct-19 02:36 PM but yeah, so much equipment just goes into the bin because some mоron thought "doesn't say gold, must be worthless" 17-Oct-19 02:36 PM and so much gets destroyed because "we can't allow anyone to reuse it because we paid full price 15 years ago" 17-Oct-19 02:37 PM What something is worth is the difference between if you know what it is or if you don't... 17-Oct-19 02:37 PM Yea there is a lot of that too... 17-Oct-19 02:37 PM funnily enough the opposite is also true 17-Oct-19 02:37 PM some scrappers jack up the prices on things they don't know because they sound sciency 17-Oct-19 02:37 PM or better yet, charge new prices for old and dead gear 17-Oct-19 02:40 PM yea... 17-Oct-19 02:40 PM it's all a mess 17-Oct-19 02:53 PM hmm... so the SEM we were having our eyes on was advertised as fully working and recently deinstalled from a company that went bankrupt 17-Oct-19 02:53 PM seller referred us to the maintenance company and they said "uhh we haven't worked on this machine since 2015 and don't support it anymore, sorry" 17-Oct-19 02:56 PM Some people think that is "recently" and also assumes its like a vehicle or something where, oh we just turned it off so it'll start again no problem 17-Oct-19 02:56 PM no... SEMs when moved will need service period pretty much lol 17-Oct-19 02:56 PM at minimum a service alignment probably 17-Oct-19 04:15 PM @Shiz most likely you can't afford the maintenance company anyway... 17-Oct-19 04:15 PM no, but we did want to get logs from them and an idea of the state of the machine :p 17-Oct-19 04:15 PM @Shiz do you know if it's a FEG (field emission) electron gun? 17-Oct-19 04:15 PM Those are going to be more complex to get running and maintain 17-Oct-19 04:16 PM it's a tungsten source, afaik 17-Oct-19 04:16 PM Getting manuals and schematics is more interesting or important than service logs I think 17-Oct-19 04:17 PM we have manuals, and are contacting the manufacturer's archive division for schematics 17-Oct-19 04:17 PM They'd be good, but schematics will let you manage things yourself after a lot of study 17-Oct-19 04:17 PM who said they may be able to help us if we send them pictures and a serial number 17-Oct-19 04:17 PM As long as it has a working computer and no cut wires you should be in OK shape to get started debugging any issues 17-Oct-19 04:17 PM to a degree yes, but I'm not sure if we have the full knowledge right now to work on SEM maintenance 17-Oct-19 04:18 PM Or more generally working electronics 17-Oct-19 04:18 PM Yeah that's what this chat is for! 17-Oct-19 04:18 PM also there's a worry about hard-to-get/expensive replacement parts -- it's not exactly the newest SEM 17-Oct-19 04:18 PM From what I've heard most stuff is pretty standard 17-Oct-19 04:18 PM I too worried about that sort of thing 17-Oct-19 04:18 PM Might just need to manually measure things when ordering new parts, rather than expect suppliers to know what your system needs based on model number 17-Oct-19 04:19 PM that's good to hear 17-Oct-19 04:19 PM and yeah :) 17-Oct-19 04:19 PM but say if for instance the turbopump is in a rough state/broken, that's not gonna be cheap to replace :p 17-Oct-19 04:19 PM and I'm not sure if we could make that fit in our current budget projection immediately 17-Oct-19 04:19 PM so we have some vested interest in knowing at least what the current state is 17-Oct-19 05:25 PM Used turbos on good condition can be had for$300-500 on the low end, especially if you build your own controller 17-Oct-19 05:38 PM If I'd have ignored those sort of worries when i first had the chance to get an SEM, I'd be a lot further along in learning and skills 17-Oct-19 06:44 PM https://www.ebay.com/itm/Electronic-microscope-RCA-model-EMU-2A-1943-1945/113890866999? 17-Oct-19 06:44 PM Holy vintage technology 17-Oct-19 06:44 PM A SEM from 1945! 17-Oct-19 06:48 PM wow 17-Oct-19 06:48 PM I thought the first TEMs/SEMs were mass-manufactured in the 60ies... 17-Oct-19 07:05 PM They left immediately but banned 17-Oct-19 07:05 PM Looks like they're avoiding bans through delayed messages 17-Oct-19 07:13 PM Joined the server. 17-Oct-19 07:21 PM I'm going to skip class for a day tomorrow and head down to Philidelphia to pick up a Hitachi S450 SEM. Looks like I'll have to take the chamber and column off their base and take the power supplies apart pretty quickly for loading 17-Oct-19 07:21 PM I hope the parts will arrive somewhat intact 17-Oct-19 07:21 PM I also just befriended the SEM manager at my school, who might be willing to let go of some Kevex digital beam control modules 17-Oct-19 07:21 PM Hopefully I can snatch up some hardware when one of the 5 SEMs at the school eventually retires 17-Oct-19 07:21 PM Chamber looks a little grimy 17-Oct-19 07:21 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-6BA7E.png 17-Oct-19 09:28 PM @Mason_Yu chamber looks clean compared to what mine looked like! 17-Oct-19 09:29 PM Really? Well we'll see tomorrow when I get to look at it myself 17-Oct-19 09:29 PM I was told that the diffusion pump oil got spilled somehow 17-Oct-19 09:29 PM I don't know if it got into the chamber or was it just on the floor, but I think I'll have to convert this to a turbo sooner rather than later 17-Oct-19 09:31 PM Lol i had diff pump oil all the way in my electron gun!!! 17-Oct-19 09:32 PM Ouch, and it lived through that? 17-Oct-19 09:32 PM Well, maybe roughing oil 17-Oct-19 09:32 PM Adam started helping me clean it ;) 17-Oct-19 09:32 PM Not running yet, I need to get a new filament, new condenser aperture, and new scintillator 17-Oct-19 09:32 PM Then we will see what happens when we try turning it on 17-Oct-19 09:34 PM What's the make and model of your SEM? 17-Oct-19 09:34 PM Jeol JSM-T200 17-Oct-19 09:35 PM Oh! The Applied Science scope 17-Oct-19 09:35 PM It sounded like I could've cleaned it and tried running it, but likely the filament had oil, so if any sort of beam would turned on, it would just contaminate the column again, needing cleaned again 17-Oct-19 09:35 PM Not the same scope, but same model 17-Oct-19 09:35 PM Got schematics from him 17-Oct-19 09:35 PM Its similar to the T100 as well 17-Oct-19 09:35 PM Which someone in EU has a blog about 17-Oct-19 09:40 PM Luckily someone on Hackaday had some thorough documentation for the Hitachi S450, and it looks like I'll get the schematic and user manual as well. It doesn't appear to be too complicated 17-Oct-19 09:40 PM Oh is that Jerry Biehler? 17-Oct-19 09:40 PM He lives nearby, well I think within half an hour 17-Oct-19 09:40 PM Yeah, looks like he's got a serious high vacuum set-up in his garage 17-Oct-19 09:41 PM He bought a 3 phase generator for something 17-Oct-19 09:41 PM Not sure what 17-Oct-19 09:41 PM I have an Edwards EXT225Hi turbopump, is a vibration dampener absolutely necessary if I want to use it for a SEM like this? 17-Oct-19 09:42 PM Necessary, no 17-Oct-19 09:42 PM But you'll likely see the effects of the turbo jiggling around on your image 17-Oct-19 09:42 PM Doesn't hurt to try. 17-Oct-19 09:42 PM It's an issue I'm looking forward to not solving on my DIY sem 17-Oct-19 09:43 PM With vidicon tubes? 17-Oct-19 09:43 PM the plan is to see if it's any use at all 17-Oct-19 09:43 PM if not, I've got a lathe 17-Oct-19 09:44 PM At least you might be able to use parts of it? 17-Oct-19 09:44 PM I don't need ultra high magnification - the project will be considered a success if I can reach beyond what an optical microscope can do, even by a hair 17-Oct-19 09:44 PM so probably something around 200-500nm resolution 17-Oct-19 09:45 PM That would still be the best DIY SEM yet right? 17-Oct-19 09:45 PM when you put it that way I get worried 17-Oct-19 09:45 PM there's a Korean institution that has a class on building a SEM IIRC 17-Oct-19 09:45 PM so I guess not the best DIY SEM 17-Oct-19 09:46 PM Well, that's kinda different 17-Oct-19 09:46 PM they do build one from scratch 17-Oct-19 09:46 PM just using a refined desing 17-Oct-19 09:46 PM so I guess.. yeah, the best DIY SEM, or at least better than the only other truly homemade one in the world... which is Ben Krasnow's 17-Oct-19 09:46 PM at this point the only thing I'm certain about is that I'm not even sure I can get an image 17-Oct-19 09:46 PM while my thing building skills are up there, this project is still shooting for the moon 17-Oct-19 09:49 PM Has anyone looked into using extractor type ion sources to do "focused" ion beams with low brightness? 17-Oct-19 09:49 PM I know that a full-on FIB built at home with gallium or helium field emission type sources is essentially impossible 17-Oct-19 09:49 PM But if you don't need the high brightness and tiny spot size, extractor sources that are just an ionization chamber surrounded by a Wehnelt cup could provide quite a bit of beam current on target 17-Oct-19 09:49 PM With heavy ions like argon, it may be possible to use it as a pretty fast etching process on a localized area 17-Oct-19 09:57 PM proton/ion injectors work that way 17-Oct-19 09:57 PM so I don't see why not, besides the physical constraints 17-Oct-19 09:58 PM The thing is I have no idea how tight of a beam you can get out of a source like that 17-Oct-19 09:58 PM with enough aperture collimation? 17-Oct-19 09:58 PM It could also have a disgusting gaussian energy profile 17-Oct-19 09:59 PM that's why you want collimation 17-Oct-19 09:59 PM look into how CERN's proton source works 17-Oct-19 09:59 PM it's like a mass spec's monochromator 17-Oct-19 10:00 PM Yeah, but collimation would decrease current on target by quite a bit 17-Oct-19 10:00 PM as is with all DIY, compromises have to be made... 17-Oct-19 10:05 PM Well, this is something I will wonder about while I'm on this 7 hour bus trip to Philly 17-Oct-19 10:05 PM The bus driver must be very fond of you to take on a SEM 17-Oct-19 10:07 PM Hah, I was actually looking into moving options where I'd get a container and some company would move it for me 17-Oct-19 10:07 PM Made the terrible mistake of giving my number to this website which apparently just sends out requests for quote to every moving company in exisitence 17-Oct-19 10:07 PM Alas, a friend is helping me, I'm running out of favors I can ask for though. 17-Oct-19 10:07 PM On the other hand, I hope to get trained in the FEI Versa 3D dual beam SEM/FIB system next week. It's free for students to use here, apparently 24/7 17-Oct-19 10:09 PM you can always sell one of those gigantic turbos you have 17-Oct-19 10:09 PM I only have one of those lol 17-Oct-19 10:09 PM And it's in active service 17-Oct-19 10:10 PM There's a $75k zeiss sem on eBay with "only 1 left!" 17-Oct-19 10:19 PM https://www.youtube.com/watch?v=ZHlgL4DZFQ0 17-Oct-19 10:19 PM Someone's got 21 of the massive turbos 17-Oct-19 10:19 PM "Please don't do this at home" 17-Oct-19 10:29 PM If I have 21 massive turbos at home, thank you I will do this at home 17-Oct-19 10:29 PM I like how you can hear the phase switching noise 17-Oct-19 10:30 PM Yeah it's very satisfying 17-Oct-19 10:30 PM it's almost as if they're driving them with pure DC 17-Oct-19 11:03 PM @Mason_Yu why would an extractor type ion source like gallium fib be impossible at home? I'm literally designing a Galinstan field emission thruster lol. It's essentially the same as a fib, except probably more current and lower beam quality. 17-Oct-19 11:04 PM how does gallium fall into this? 17-Oct-19 11:04 PM or a liquid alloy in general 17-Oct-19 11:04 PM Fall into what? 17-Oct-19 11:04 PM what it does 17-Oct-19 11:04 PM What I was referring to with the gallium source is not the extractor type, its the field emission type with orders of magnitudes higher brightness 17-Oct-19 11:04 PM You know, the ones involving a tip only 3 atoms wide 17-Oct-19 11:04 PM Yeah, a liquid metal thruster is field emission lol 17-Oct-19 11:04 PM You don't need that fine tip for it to work though 17-Oct-19 11:04 PM I'm going to use just off the shelf micrometer tungsten needles 17-Oct-19 11:04 PM You could chemically polish it finer probably 17-Oct-19 11:06 PM But for focusing a beam to do etching on a fine spot, wouldn't smaller be better? I would be interested to see how good a homemade source can be though 17-Oct-19 11:06 PM There's also the issue of feeding the liquid metal/helium to this tip in a controlled manner under ultra high vacuum too 17-Oct-19 11:07 PM It would be lol, but why start hardcore tiny? Just go larger first, make it work, then refine 17-Oct-19 11:07 PM Feeding liquid metal is not am issue in high vacuum 17-Oct-19 11:07 PM It is just wicked to the tip 17-Oct-19 11:07 PM If you look at commercial fib tips, it's just an ultra fine tungsten needle dipped in a resevoir, I think maybe like a tiny glass vike, or even heated wicking crucible 17-Oct-19 11:08 PM I wonder if you can make an indirectly heated x-ray or SEM cathode out of microprobing needles 17-Oct-19 11:08 PM they sell off-the-shelf submicron needles 17-Oct-19 11:09 PM Why not lol, anything can be used as a cathode 17-Oct-19 11:09 PM I don't see an issue with it 17-Oct-19 11:09 PM but one that can shove off enough electrons to be useful? 17-Oct-19 11:09 PM pushing 50-100uA through it seems difficult 17-Oct-19 11:10 PM Sure lol. Sem and fib need way less current than what I do, it's certainly possible 17-Oct-19 11:10 PM for x-rays, higher current = better 17-Oct-19 11:10 PM now I'm thinking about a dual needle x-ray tube 17-Oct-19 11:10 PM needle cathode, needle anode 17-Oct-19 11:10 PM Well, depends 17-Oct-19 11:11 PM but then you get the issue of dissipating 1-2 watts on the anode 17-Oct-19 11:11 PM Flash xray tubes are optimized for higher voltage rather than current necessarily. Often they are 3x the input driver impedance to get a voltage gain 17-Oct-19 11:11 PM I'm talking about CW 17-Oct-19 11:11 PM Oh lol, yeah, like I said, depends 17-Oct-19 11:11 PM I know there was talk here about liquid metal anode xray sources 17-Oct-19 11:11 PM I think that's very do able at home 17-Oct-19 11:12 PM I should again clarify that what I was referring to with the homemade FIB is the issue of getting a high quality beam that can be focused down to sub-nm spots. I didn't mean field emission tips in general is not possible at home with a tungsten needle 17-Oct-19 11:12 PM the hobbyist dream is a ~1-10W x-ray tube with a <10um focal spot 17-Oct-19 11:12 PM I bought a 40-130kV 16um x-ray head, but it's still sitting in the US and waiting for a person to help me ship it 17-Oct-19 11:12 PM massive power output though 17-Oct-19 11:13 PM Well, like I said, start bigger, get it working, then optimize down. 17-Oct-19 11:13 PM What power? 17-Oct-19 11:14 PM 39W into a 16-50 micron variable spot 17-Oct-19 11:14 PM constant 300uA at 40 to 130kV 17-Oct-19 11:16 PM Nice lol, pretty solid for continuous. Sounds like you got a good deal on it. Hopefully it's fully functional and you can just start using it. When I optimize my system for xray yield, it will be scary. kA beams on a heavy tungsten target at hundreds of kV makes even me nervous lol. 17-Oct-19 11:16 PM I paid less than $1000 for it, so I'd consider it a good deal 17-Oct-19 11:16 PM but it'll still cost me $220 to ship 17-Oct-19 11:16 PM ;~; 17-Oct-19 11:17 PM Well, at least you will have a hopefully great system if it works! 17-Oct-19 11:17 PM Still way cheaper than new 17-Oct-19 11:17 PM seller said tested working 17-Oct-19 11:18 PM Even better lol 17-Oct-19 11:18 PM but I can't trust them on that, and if it's a dud, refunding will be very hard, considering I'm going through someone to buy it 17-Oct-19 11:18 PM on that note, if anyone has hamamatsu x-ray head rs232 protocol information, that would be appreciated... 18-Oct-19 04:37 AM ugh man making me jealous again of that massive turbo you have @Mason_Yu with that video haha 18-Oct-19 04:38 AM Well you made me jealous with your shelf full of vacuum stuff and smaller turbos 18-Oct-19 04:39 AM Can't build too much with a pile of elbows and such heh... 18-Oct-19 04:39 AM But yea I'd happily start doing some horse trading for stuff. 18-Oct-19 04:39 AM Also I did try cleaning one of those turbos that was covered in dust... 18-Oct-19 04:39 AM I took a clean paintbrush and stuck that down in there and spun the blades by hand letting it knock most of that stuff free, then just blew most of it out 18-Oct-19 04:39 AM it'll probably be clean enough that when it first spins up it'll knock most of the rest of whatever is left off.. 18-Oct-19 04:40 AM They all had controllers attached right? 18-Oct-19 04:40 AM there was some nastyness down in the blades too though, like I put an acetone then alcohol soaked kimwipe in through the roughing port and gave it a spin to get some cleaned out of there too 18-Oct-19 04:40 AM I have enough controllers for all but one? 18-Oct-19 04:40 AM I think there are 4 pumps 18-Oct-19 04:40 AM there are 2 8" 1 6" and like an ISO 100? 18-Oct-19 10:13 AM https://www6.slac.stanford.edu/news/2019-08-12-atomic-trojan-horse-could-inspire-new-generation-x-ray-lasers-and-particle 18-Oct-19 11:40 AM Thats awesome. 18-Oct-19 07:18 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20191018_204436-A75C8.jpg 18-Oct-19 07:18 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20191018_214324-C1BD5.jpg 18-Oct-19 07:18 PM SEM in a car 18-Oct-19 07:56 PM Someone said FIB?? The height of the horizontal bar in the H character measures 50nm tall. 18-Oct-19 07:56 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191018_195516-28FF1.jpg 18-Oct-19 07:56 PM Here's what the crappy bitmap I used to etch it looks like 18-Oct-19 07:56 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191018_195816-1CEE8.jpg 18-Oct-19 07:56 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191018_195821-073AD.jpg 18-Oct-19 08:24 PM That is just plain cool 18-Oct-19 09:21 PM If you want me to etch your name on something, let me know 18-Oct-19 09:27 PM I have an idea on what you can manufacture with the FIB 18-Oct-19 09:27 PM Wire bonding practice wafers 18-Oct-19 09:27 PM Rows of plain metal strip next to bonding pads of various sizes 18-Oct-19 09:27 PM From huge to tiny 18-Oct-19 09:27 PM (say, 300um to whatever the current smallest size is) 18-Oct-19 09:27 PM because I gave you this idea, you are now morally obligated to etch my name all over it :P 18-Oct-19 09:48 PM The pads would be 300uM to smaller? What size would the wires be? Would the wire loop from one pad to the next so you could do loopback testing? 18-Oct-19 09:49 PM 300um to smaller, yeah, gradually reducing for testing and learning 18-Oct-19 09:49 PM wires... irrelevant, really, unless you're talking about the second bonding point 18-Oct-19 09:49 PM which should maybe be 10-30% larger than the actual pad size 18-Oct-19 09:49 PM and bonding from wherever you want to wherever you want, just practice wafers 18-Oct-19 09:49 PM skip a pad if you're learning to do long bonds, bond from pad to pad if you want shorter, bond from pad to strip if you're just practicing 18-Oct-19 09:49 PM if you could manufacture small(<100mm) wafers just full of thousands upon thousands of these pads in different sizes, I reckon it'd actually be a worthwhile product 18-Oct-19 09:49 PM nothing but pads 18-Oct-19 09:52 PM It sounds like a FIB lithography project rather than a FIB etching project 18-Oct-19 09:52 PM which one would be faster? 18-Oct-19 09:52 PM Litho 18-Oct-19 09:52 PM then I guess litho is the way 18-Oct-19 09:52 PM could also be interesting to see FIB-made complex multilayer x-ray target anodes manufactured 18-Oct-19 09:52 PM with anti-scattering inside, to make the sharpest x-ray outputs 18-Oct-19 09:52 PM nanofocus x-ray 18-Oct-19 09:52 PM that's definitely an etching project 18-Oct-19 09:52 PM etching + litho maybe even 18-Oct-19 09:54 PM Hmm 18-Oct-19 09:54 PM you could also manufacture neutristors 18-Oct-19 09:54 PM I don't know what they generally look like 18-Oct-19 09:54 PM So you just want a nice sharp tip for electron emission? 18-Oct-19 09:55 PM sharp tip for emission, and very fine targets(anodes) for braking radiation without scattering and diffraction 18-Oct-19 09:55 PM sharp tips are mostly made by electropolishing 18-Oct-19 09:55 PM though if you could use the FIB to cleave out a super flat tiny spot(<3um), they could also be used in "reverse" x-ray tube target fashion 18-Oct-19 09:55 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/microfocusxray-B2C91.png 18-Oct-19 09:55 PM this is the only x-ray tube I know of that operates on this principle, and it's one hell of a unicorn 18-Oct-19 09:55 PM the Russian BS7-W 18-Oct-19 09:55 PM 10-15kV, 5 degree beam, and a focal spot of less than.... I want to say 5 microns? 18-Oct-19 09:55 PM hot cathode and ZERO focusing required, just filament and extraction 18-Oct-19 09:55 PM I tried to model it in COMSOL, but failed quite spectacularly 18-Oct-19 09:55 PM you could also play with x-ray optics 18-Oct-19 09:55 PM http://photon-science.desy.de/research/research_teams/fs_petra/overview/x_ray_optics/nanofocusing_lenses/index_eng.html 18-Oct-19 09:59 PM So in that tube the anode has the aperture? 18-Oct-19 09:59 PM Where the xray cone starts? 18-Oct-19 09:59 PM the anode is the needle 18-Oct-19 09:59 PM the cathode is the red filament, and the cone is... a wehnelt and a collimator 18-Oct-19 09:59 PM the electrons boil off, get pinched by the wehnelt, then somehow that results in them hitting only the very tippy tip of that needle, the x-rays go BACK THROUGH the wehnelt, AROUND the filament and out the window 18-Oct-19 09:59 PM it's like a "folded" tube 18-Oct-19 10:00 PM When you say a fine anode, do you mean thinning it to a smaller gauge, basically? 18-Oct-19 10:00 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/images-51F70.png 18-Oct-19 10:00 PM this is what I mean by a fine anode 18-Oct-19 10:02 PM So the tip of that needle would be a different compound than the bulk below in that image? 18-Oct-19 10:02 PM I'm thinking that that would actually work, yeah 18-Oct-19 10:02 PM Just for cost savings? 18-Oct-19 10:02 PM for energy cutoff 18-Oct-19 10:02 PM ideally you want the x-rays to only be generated in one atom, but that's obviously not possible 18-Oct-19 10:03 PM The interaction volume seems like it would not change too much 18-Oct-19 10:03 PM it makes the focal spot bigger 18-Oct-19 10:03 PM But I guess the substrate might not generated x rays 18-Oct-19 10:03 PM you don't want to make a microfocus source by just collimating the crap out of it 18-Oct-19 10:03 PM the brightness goes to nil 18-Oct-19 10:03 PM (and your beam angle is also tiny) 18-Oct-19 10:06 PM Screenshot (Oct 18, 2019 10:06:36 PM) 18-Oct-19 10:06 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_20191018-220636-A596A.png 18-Oct-19 10:06 PM Neutristor 18-Oct-19 10:06 PM Basically a plasma chamber but at microscale i guess 18-Oct-19 10:06 PM Apply a voltage across the opposing horizontal electrodes, where both electrodes are deuterium 18-Oct-19 10:10 PM This seems like a FIB thing to me, for prototyping 18-Oct-19 10:10 PM or maybe etching of sorts 18-Oct-19 10:10 PM wonder what the deuterium is alloyed with 18-Oct-19 10:11 PM I was thinking of trying to make these microscale vacuum tubes that I found last night 18-Oct-19 10:11 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/thomas_s03_glow_discharge-7AB8A.pdf 18-Oct-19 10:11 PM "Glow discharge in microfluidic chips for visible analog computing" 18-Oct-19 10:12 PM nanonixies! 18-Oct-19 10:12 PM oh wait that's the shortest parth problem 18-Oct-19 10:12 PM Both!! 18-Oct-19 10:12 PM someone did this with acrylic! 18-Oct-19 10:12 PM it burned out but it worked 18-Oct-19 10:14 PM Oh that's cool 18-Oct-19 10:14 PM I wonder if you can etch nano nixie electrodes 18-Oct-19 10:14 PM make some z-tape-style vacuum passthroughs if that's possible at all 18-Oct-19 10:14 PM make nixie wristwatches 18-Oct-19 10:14 PM but this time actually small 18-Oct-19 10:16 PM Probably with multiple steps, start with glass, sputter with metal, spin coat photo resist, fib litho, plasma etch metal where litho removed resist, add glass coverslip? 18-Oct-19 10:17 PM or just take thin foil and rip into it with the fib 18-Oct-19 11:35 PM @nmz787 freaking FIB is awesome, congrats on getting it going 18-Oct-19 11:40 PM @Conmega thanks, it's been fun and challenging!! If you have any project ideas or requests, send them my way 18-Oct-19 11:50 PM May have some FIB work for silicon stuff someday haha. But I have lots to do before that. 19-Oct-19 01:36 AM Got my decade old eeePC to work as a bridge between my laptop and the internet, now to move this little guy in between my FIB PC and the system controller 19-Oct-19 01:36 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191019_013254-5A3D7.jpg 19-Oct-19 01:36 AM (for Ethernet sniffing) 19-Oct-19 03:27 AM Joined the server. 19-Oct-19 04:45 AM Joined the server. 19-Oct-19 06:27 AM I can still use my eeepc for arduino coding 19-Oct-19 06:53 AM neat! 19-Oct-19 09:38 AM Joined the server. 19-Oct-19 09:38 AM Hi there ! Thanks for invitation 19-Oct-19 09:40 AM Welcome! 19-Oct-19 09:42 AM Squirrel xD neat ! 19-Oct-19 09:46 AM all thanks to someone who never really read my name and all of a sudden called ne Squirrel xD 19-Oct-19 09:47 AM skwirel 19-Oct-19 10:08 AM welcome @Black Lemming ! 19-Oct-19 11:58 AM Hositrad are still trying to get me to pay an invoice I didn't agree to, for a mistake they made. I just received a physical letter from them with the invoice inside. Still addressed to a nonexistent company("Spirit") 19-Oct-19 12:03 PM wth 19-Oct-19 02:20 PM @Black Lemming ever done any roll to roll mass production of holograms on plastic film? Thermal/pressure or UV casting? 19-Oct-19 06:56 PM evening! 20-Oct-19 12:27 AM Morning! 20-Oct-19 12:27 AM Moin! 20-Oct-19 09:24 AM Joined the server. 20-Oct-19 09:58 AM @nmz787 nope I’m pretty basic for now embossed are parts of what I’d like to try one day though 20-Oct-19 05:46 PM Well I successfully tapped my FIB's communication to its control PC! Was able to see some data in plaintext as well, only a bit was understandable so far 20-Oct-19 05:47 PM If you can get all the software out, I can probably help you reverse engineer it 20-Oct-19 05:47 PM Find all the commands 20-Oct-19 06:01 PM It's written in Delphi 20-Oct-19 06:01 PM ew 20-Oct-19 06:01 PM IDA will still eat it 20-Oct-19 06:01 PM spit out all the strings 20-Oct-19 06:02 PM We tried ghidra, idapro, and some delphi specific stuff 20-Oct-19 06:02 PM Ida didn't show much 20-Oct-19 06:02 PM But yeah i can put the software online later 20-Oct-19 06:03 PM https://discord.gg/PSfAu8N 20-Oct-19 06:03 PM These guys are wizards 20-Oct-19 06:03 PM The delphi specific stuff showed the most so far, but they are all unmaintained for at least a decade and suck pretty bad 20-Oct-19 06:03 PM I'll let them know who you are 20-Oct-19 06:03 PM Cool 20-Oct-19 06:03 PM Thanks 20-Oct-19 11:30 PM Lol 21-Oct-19 12:25 AM Joined and left. XD 21-Oct-19 12:25 AM Not the reverse engineering I was expecting. 21-Oct-19 03:01 AM well, tonight I end with a command-set for some in-built scripting language, which I guess I'll write a Python wrapper for: http://diyhpl.us/~nmz787/fib/batch.translated 21-Oct-19 09:22 AM Joined the server. 21-Oct-19 11:00 AM Got another flask stand for my chemistry stuff at the MIT Flea, woot! Now I just need to get more glassware :) Have to figure out what sizes of ground glass fittings I am going to be using/need based on what I already have... 21-Oct-19 11:00 AM Seems to be a few standards of sizes. 21-Oct-19 11:05 AM 24/40 seems to be the most popular size in the states, especially if you're doing things with larger (500-1000ml) volumes 21-Oct-19 11:05 AM But make sure you buy a bunch of adapters because those things are worth their weight in gold when it's 2am and you really need to fit a 19/22 thermometer into a 24/40 distillation adapter... 21-Oct-19 11:43 AM 24/40 for USA, 24/29 for EU 21-Oct-19 11:52 AM eeepcs seem like really good dumb terminals for that kind of thing 21-Oct-19 11:52 AM .. whoops, scrolled up a bunch, lol 21-Oct-19 12:00 PM Cool thanks guys. 21-Oct-19 02:10 PM good afternoon! 21-Oct-19 03:03 PM @Conmega what are your chemistry plans that require gassware in good quantity? 21-Oct-19 06:49 PM More-so just to have them available if I want to start learning/experimenting with things... I like collecting tools of science if you haven't noticed yet. :P 22-Oct-19 01:41 AM sooo, if I needed to build a really large vacuum chamber, like 3 ft x 3 ft x few inches... for plasma application... where should I start? I mean, I obviously have a lot on my plate as far as designing a plasma system, i.e. if it were capacitively coupled then what electrode material/size/placement... or inductively coupled, I think the chamber needs to be dielectric then (would some sort of paint work to coat metal?). 22-Oct-19 01:41 AM but obviously there's the vacuum pump aspect too 22-Oct-19 01:41 AM like, if I stuck small rough and turbo pumps on the chamber, would it ever pump down, or do you need higher liters/min pump speed for some reason for larger chambers? 22-Oct-19 01:41 AM (I think the process would be infrequently used enough that a slow pumpdown would be OK) 22-Oct-19 04:46 AM Hi Folks! I bought a Leybold Trivac D8B forepump some time ago, with the aim of setting up a vacuum system for sputtering, and eventually to play with some turbos we have lying around. It was only 75 euros, and it is in dire need of some maintenance. All the machine parts seem to be in excellent condition, but the seals/gaskets will have to be replaced, and I'm considering taking apart the pump module to replace the vanes as well. Better to sink some money into this thing than spend an equal sum on a lesser quality new unit, i think. Are there people here with experience working on these pumps? They seem to be quite common. Where do you prefer to get your parts, and would you trust aftermarket alternatives? I'm based in the Netherlands by the way, at the same hackerspace as Shiz et al (hi!). Leybold really like to play close to their chest when it comes to the more involved maintenance procedures, so i would also be quite interested to hear any experiences of taking apart the Trivac B series pump modules. This deliciously vintage film posted on youtube (the music alone is worth the price of admission) is still the only bit of info i've managed to find on what Leybold calls "stage 3" maintenance, so any more info would be greatly appreciated! https://youtu.be/KkNtV-VGJ6Y 22-Oct-19 06:25 AM @nmz787, Welding is your second largest issue outside of cost; If you have a decent TIG machine you are familiar with then you might be able to build something quite decent out of stainless, but if the chamber is only supposed to be a few inches tall you will be introducing porosity and virtual leaks from welding the outsides. Not a major issue for plasma use, just keep it in mind. If you only have a stick welder or don't think you can make a completely tight fusion weld around the box, go for more normal carbon steel and take care not to warp the chamber too much. Cut holes and taps afterwards. Also, calculate the forces on the top and bottom plates under the vacuum, they may need reinforcing struts to keep from buckling if they are too thin. 3'x3' is pretty wide. I think Capacitively coupled or RF is the way to go, ICP would require a nonconducting (often i.e. quartz) section for gas feed and ionization as metal chamber walls are extremely good faraday cages. For flow rates do some basic calculations on chamber conductance, preferred gas pressure and max feed gas flow rates. As long as you don't have leaks the chamber will pump down, it'll just take a while with a teeny pump. A small pump also means you don't have to waste nearly as much feed gas to maintain pressure, but will result in a dirtier plasma. Electrode materials depend on plasma temperature and composition. If you don't mind some contamination, won't be running too hot and will be using low pressures and duty cycles, just go simple and use a stainless sheet. What plasma applications are we talking? Reactive Ion Etching/Plasma Cleaning? 22-Oct-19 07:04 AM Heh was looking at old inficon quartz crystal thin film deposition controllers seeing if they will work with the sensor I have and turns out looking in the manual an an OLD IC6000 the head I have is in there! Looks exactly the same! 22-Oct-19 07:04 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-EDB8A.png 22-Oct-19 07:04 AM And its Bakeable!! 22-Oct-19 07:04 AM woot 22-Oct-19 07:53 AM Well getting an IC 6000 for 40 bucks shipped is cheap enough I'm ok with using an older unit. Also the docs for it are good, full schematics. So I will get that and fix it up and get it going. It also has two control modules on it so I can end up using it for controlling two evap/sputter sections, probably for two different metals. 22-Oct-19 07:53 AM Just need to find a second quartz head 22-Oct-19 07:53 AM Unfortunately they are apparently a ton of money on ePay generally. I was super lucky to get a clean unused one for cheap. 22-Oct-19 07:53 AM But totally going to start building up some chambers and fixtures now that I found some 3-4ft sections of 8020 at the surplus store for like 10 bucks a piece <3 22-Oct-19 10:36 AM @Conmega I've been planning to make my own QCM with some 32kHz realtime clock computer crystals. It should just be a driver circuit that can also detect the resonant frequency, and have enough resolution to detect small shifts of that freq (as stuff deposits it will change) 22-Oct-19 10:36 AM @hanstj wow, thanks! Application in mind immediately is anti-adhesion layer coating on a big nickel sheet that is to be wrapped around a drum for roll-to-roll nanoimprint lithography. 22-Oct-19 10:36 AM @hanstj C4F8 was the gas I've been reading about, combined with around 15% oxygen, 30 second processing time 22-Oct-19 10:49 AM https://www.sciencedirect.com/science/article/pii/S0025540814007806 22-Oct-19 10:49 AM There's also a vapor phase coating procedure using a chemical called FDTS, you put a boat of the liquid in a vacuum oven with your sample, pull vacuum and warm slightly. 22-Oct-19 10:49 AM My thought is the plasma process will have better bonding strength va the vapor phase idea, since the plasma has more energy. 22-Oct-19 10:49 AM (more energy to start the surface reaction, higher bond strength) idk if that's reasonable logic or not 22-Oct-19 10:57 AM @nmz787 so I am not sure the significance of the frequency but I know almost all of them used in the industry are 5 or 6 Mhz crystals... 32khz may be way too slow? I'd imagine the slower the frequency the less resolution you'll get since it'll take more material to change the frequency, where as 5-6Mhz will change faster with smaller changes allowing for a higher resolution with less complex circuitry and lower resolution ADCs and such I'd think. 22-Oct-19 10:57 AM I think it's the size and ease of decapping the RTCs 22-Oct-19 10:57 AM So if your trying to measure THICK coatings a slower frequency may be best, but if you want to see angstroms of thickness best to maybe try and go for the standard crystals 22-Oct-19 10:58 AM I doubt bandwidth would be that important for starting out 22-Oct-19 10:58 AM You could always pulse your deposition power source, or the gas valves 22-Oct-19 10:58 AM the proper crystals also are pretty cheap, like 10 for 30 bucks 22-Oct-19 10:58 AM just need to make a little holder 22-Oct-19 10:58 AM To slow things down for the qcm to catch up 22-Oct-19 10:58 AM Oh nice 22-Oct-19 10:59 AM Also honestly a lot of the controllers go pretty cheap, the holders are expensive, so if you can machine up your own you can use a proper controller cheap 22-Oct-19 10:59 AM Getting any crystal should be pretty similar to build a controller for i think 22-Oct-19 10:59 AM and the nice thing is the right controllers have setup for shutters, and heat soak then open the shutter, coat, close the shutter at your desired thickness 22-Oct-19 10:59 AM its reallllyyy nice for just controlling your process nice and easily 22-Oct-19 10:59 AM though it is a fairly simple process to control manually/semiautomated 22-Oct-19 10:59 AM Just need to heat up the source/boat, let it heat soak for awhile then open the shutter, measure the thickness your going for then stop 22-Oct-19 11:01 AM Seems like a shutter is not for the qcm tho 22-Oct-19 11:01 AM Right,? 22-Oct-19 11:01 AM That'd be for the deposition target/substrate 22-Oct-19 11:01 AM though some of the controllers I see up to 2-3 cycles of this, not sure of the significance but I assume for purity you want to make sure you heatsoak long enough otherwise you get contaminates flying off the source initially probably? 22-Oct-19 11:01 AM Seems you're talking about evaporation 22-Oct-19 11:01 AM Which i haven't ever really been interested in personally 22-Oct-19 11:02 AM uhm so you want one for the QCM too probably since apparently sometimes when initially heating your source it can throw large particles off 22-Oct-19 11:02 AM Hmm 22-Oct-19 11:02 AM and if you hit your crystal with one of those it damages it or stops it oscilatting 22-Oct-19 11:02 AM at-least the doc I just read said 22-Oct-19 11:02 AM also longer life out of your crystal 22-Oct-19 11:02 AM I haven't heard of preheating the qcm 22-Oct-19 11:02 AM this is thermal/ebeam/whatever evaporation yes 22-Oct-19 11:02 AM is what I am talking about 22-Oct-19 11:03 AM I guess some steps like ashing or flushing might not need the qcm for monitoring 22-Oct-19 11:03 AM sputtering is apparently a bit special and sometimes even requires special crystal holders? and they have magnets in them and you must align them with the magnetic field of the sputtering/rf setup or whatever 22-Oct-19 11:03 AM @nmz787 Aah, was about to ask about the oxygen. Thanks for the info, haven't looked much into nanoimprinting before. Got something new to read up on for the evening! I see it's most common to use ICP for C4F8, but there has been decent success with capacitive coupling aswell. You will probably get a better, thinner overall coating from FDTS as most CVD/MVD- techniques with some process control (just a vacuum gauge, some thermocouples and a few PID loops) will allow you to deposit even, incremental monolayers, you need rather fancy plasma diagnostics to be able to accurately deposit C4F8 as the rate is strongly temperature gradient dependent and your CCP electrodes will not give uniform field strengths. Also, a ~1kW RF generator, complicated plasma monitoring and soforth is far more work than a gentle boat setup with a couple of circulators and some copper coils to control chamber and substrate temperature. If the FDTS isn't too expensive, just go for that. 22-Oct-19 11:03 AM oh no you don't need that for ashing or something 22-Oct-19 11:03 AM generally ashing is for removing organic layers like resist layers 22-Oct-19 11:03 AM where you just want it ALL GONE 22-Oct-19 11:03 AM and QCM won't work with that anyway unless you also coat the crystal with the resist at the same time with the same thickness 22-Oct-19 11:03 AM which would be weird... 22-Oct-19 11:06 AM @Conmega well something like DRIE uses qcm and has an intermediate ashing part of the cycle 22-Oct-19 11:06 AM Ashing/etching 22-Oct-19 11:06 AM ALD too uses this commonly as part of their"super cycles" 22-Oct-19 11:20 AM Wait why would you use QCM for RIE? 22-Oct-19 11:20 AM I.e. maybe you have more control over etching a layer than depositing, so your deposition cycle consists of depositing (too much) then etching (just enough) 22-Oct-19 11:20 AM That... doesn't make sense how that works... 22-Oct-19 11:20 AM you'd only be-able to etch whatever material is on the QCM at that rate... 22-Oct-19 11:20 AM like most of them are covered in a thin gold coating I think initially? 22-Oct-19 11:20 AM so if your etching silicon... the flourine won't etch that the same as it etches the silicon 22-Oct-19 11:21 AM Well i think for DRIE you'd be watching the passivation layer build up, so I guess you'd want a shutter for that 22-Oct-19 11:21 AM To shut out the sf6 step 22-Oct-19 11:22 AM That would still be... hard to associate since not everything is deposited onto the other surface (I assume that is what you mean by passivation layer buildup, on the opposite plate) since most of the material carries out of the vacuum through your pumps I would assume... 22-Oct-19 11:23 AM Passivation layer is a deposition step 22-Oct-19 11:23 AM I think RIE is just simple enough that you just make sure your gas feed and pump out is constant enough you just turn on your power source for x amount of time, measure the etch depth in an SEM and that tells you the etch rate and how long you need to etch for 22-Oct-19 11:23 AM It should not be directionally dependent from what I know 22-Oct-19 11:23 AM DRIE != RIE 22-Oct-19 11:25 AM Ahh right DEEP reactive ion etch 22-Oct-19 11:25 AM DRIE is a two step cycle, you deposit passivation layer, then sputter with reactive ions, preferentially etching surface in the normal direction, but also slightly the passivation on the sidewall 22-Oct-19 11:25 AM uhm yea I would just have assumed that was a timed and controlled process 22-Oct-19 11:25 AM didn't realize they would use QCM for that 22-Oct-19 11:25 AM The you repeat the deposition and etching 22-Oct-19 11:26 AM yea yea thats cool 22-Oct-19 11:26 AM more useful for MEMs I think than just standard silicon circuits 22-Oct-19 11:26 AM thus why I am not concerned with it myself. 22-Oct-19 11:26 AM Honestly I would just try to do it with timing before being concerned about adding complexity with a homemade QCM 22-Oct-19 11:26 AM I think its more of just a timed computer controlled process. Never personally seen machines with QCMs in them. 22-Oct-19 11:26 AM https://www.semanticscholar.org/paper/AN-ultra-low-cost-deep-reactive-ion-etching-(drie)-Gould-Hsing/f6fa00694932ae4e8dfbf22315ddca2b8c16c86a 22-Oct-19 11:26 AM For example 22-Oct-19 11:26 AM https://d3i71xaburhd42.cloudfront.net/f6fa00694932ae4e8dfbf22315ddca2b8c16c86a/2-Figure1-1.png 22-Oct-19 11:34 AM Yeah but I like data and feedback for debugging 22-Oct-19 11:34 AM I'm pretty sure most of the current and cutting edge processes use QCM for various steps 22-Oct-19 11:34 AM And DRIE is often used for MEMS, but also for things in modern silicon processing like making TSVs (through silicon vias) 22-Oct-19 11:34 AM I want to make fluidic channels with integrated electrodes and onchip amplifiers 22-Oct-19 11:37 AM @nmz787 Get some old or new old stock HC-6U cased crystals and open those, easy with a dremel. Then you just need a simple relatively low drift crystal oscillator for it and a suitable frequency counter. 22-Oct-19 11:37 AM Hrm ok, I suppose go for it then! I just would think if you want to do research into DRIE I wouldn't also do research into your instruments and just try and get ahold of proper instruments, otherwise you could get some unknowns in your process. 22-Oct-19 11:37 AM So i need to kludge it all together anyway 22-Oct-19 11:37 AM I'd use a 3.200MHz HC6U one, but I have like 100+ pcs of those thanks to a hamfest bargain 22-Oct-19 11:39 AM @rfs good tip, I'll grab some. i feel like i heard that model before, but dont see it in my email so I guess i never ordered any 22-Oct-19 11:40 AM It's large 22-Oct-19 11:40 AM And oldest have soldered cases, so VERY easy to open. 22-Oct-19 11:40 AM Newer stuff is welded steel, but easy to dremel 22-Oct-19 11:40 AM @Conmega yeah I have a problem getting deep into stuff and trying to do it all. It's a bit tough when you want to do more than what already exists i guess 22-Oct-19 11:40 AM And on a budget 22-Oct-19 11:42 AM Yup I get that... I've been telling myself to stop wanting to make every tool myself because its just too frustrating and can ussually take either more money or more time or sometimes both vs just finding the right tools for cheap and waiting and hunting them out. 22-Oct-19 11:42 AM Honestly its just the type of thing you have to determine if its worth doing yourself or finding the tool. 22-Oct-19 11:42 AM Like I can get RIEs, little desktop ones or large setups, but they generally go for a few thousand dollars, I do have ePay searches for them but nothing cheaper than like 2 grand has popped up yet and most of the small ones will probably be slightly limiting. 22-Oct-19 11:44 AM The only issue with DIY thickness monitors is that calibrating them is very hard 22-Oct-19 11:44 AM But like for example an RF supply... while I could try to buy one I don't know much about the design of that type of circuit and will probably have problems just tuning my system so I decided it will probably be cheaper/easier to just find an RF supply for cheap 22-Oct-19 11:44 AM Haha well at least I have a FIB to cross section things and inspect! 22-Oct-19 11:44 AM heh yes you do! 22-Oct-19 11:44 AM @Deleted User actually... 22-Oct-19 11:44 AM there is no calibration 22-Oct-19 11:44 AM its more like a load cell 22-Oct-19 11:45 AM Yeah jack of all trades, master of none syndrome 22-Oct-19 11:45 AM you just tare it generally 22-Oct-19 11:45 AM Hertz to angstroms is the hard bit 22-Oct-19 11:45 AM right that is the problem, figuring out what your scale is 22-Oct-19 11:45 AM but if you have an SEM or something 22-Oct-19 11:45 AM you can deposit stuff, see how much your hertz changes then measure in your FIB or SEM a cross section of how thick it is 22-Oct-19 11:45 AM easy peasy 22-Oct-19 11:45 AM But you will want a reliable very similar crystal each time 22-Oct-19 11:45 AM so stock up if you decide to base it off something otherwise you will be doing that every time you change crystal models heh 22-Oct-19 11:45 AM But yea, I dunno I suppose I'm being a downer, you could totally build your own QCM but I'd recommend also just keeping an eye out for them :P 22-Oct-19 11:49 AM unless it's cheaper than scrap, it's easier to build your own 22-Oct-19 11:49 AM Eh I just got the controller for my stuff for 40 bucks shipped... 22-Oct-19 11:49 AM the older controllers are dirt cheap, the crystals a pack of 10 new are like 30-40 bucks 22-Oct-19 11:49 AM its honestly just the little holder you put the crystals into and mount in the chamber, that passthrough piece that is hard to search for and find/buy 22-Oct-19 11:49 AM they are all over I bet but no-one knows how to list them or what they are 22-Oct-19 11:50 AM you don't need a special passthrough 22-Oct-19 11:50 AM When I got mine originally I thought it was a little sputter head or something haha 22-Oct-19 11:50 AM kf10 and 2 pins 22-Oct-19 11:51 AM oh no but they are generally one assembly... and have water cooling lines 22-Oct-19 11:51 AM cooling might be important right 22-Oct-19 11:52 AM Hmm yeah true 22-Oct-19 11:52 AM https://www.ebay.com/itm/Inficon-007-221-Feed-Through-w-ALD-Sensor-Crystal-Sensor-Feedthru/323142253246 22-Oct-19 11:52 AM for example 22-Oct-19 11:52 AM this is basically what I have but a LOT longer and maybe some kind of shutter assembly 22-Oct-19 11:52 AM though stupid expensive haha 22-Oct-19 11:52 AM Here is a non high temp bakeable one 22-Oct-19 11:52 AM https://www.ebay.com/itm/INFICON-FEEDTHROUGH-SELECTION-with-Dual-Crystal-Sensor/123214721401 22-Oct-19 12:33 PM Honestly if I could just find a service to run the plasma step on that 3ft item, i would,since that is a project I'm working on for a company with some money 22-Oct-19 12:50 PM Probably can somewhere... I'd start asking around haha. 22-Oct-19 01:25 PM Another question: what oil do you guys use in your rotary vane pumps? The Trivac manual mentions a leybonol LVO "100" mineral oil, but locally i can mostly find vacuum pump oils with a slightly lower base viscosity of around 70 cSt at 40 degrees C. Does this matter enough to worry about? 22-Oct-19 01:30 PM i've just been buying cases of https://www.duniway.com/part/mpo-190-1 for my leybold trivac d8c, i've never figured out how much viscosity matters 22-Oct-19 01:30 PM duniway does sell a higher-viscosity oil though 22-Oct-19 01:41 PM The viscosity varies so much with temperature, perhaps a few centistokes here or there won't make too much of a difference, as long as the other properties are there. I do wonder whether it's better to go lower or higher. 22-Oct-19 05:28 PM viscosity will always go down with higher temperature 23-Oct-19 07:15 AM Most roughing pumps warm up and depending on gas load and ballast setting they can get quite hot 23-Oct-19 07:15 AM I have never heard of specifications of viscosity or anything... if your in the states just get this: https://www.ldsvacuumshopper.com/lds19mecpumf.html 23-Oct-19 07:15 AM Pretty much all standard roughing pump oil is just highly refined mineral oil... Nothing else special about it really, some could have additives I suppose. There is a different type of oil if you need to be pumping oxygen though, like pure oxygen that is in a system for like plasma ashing... That you need an oxygen rated pump and oil. 23-Oct-19 07:15 AM Otherwise you make a bomb 23-Oct-19 07:55 AM There is an iso standard classification for viscosity, and here in the netherlands at least it seems to be used widely as a way of differentiating the various types of vacuum oil on offer. Anyway, I just order a jerrycan of ISO VG 68, which in terms of viscosity is somewhere in between the oil you recommended and the oil that leybold recommends for this pump. 25-Oct-19 02:09 AM does anyone here know anything about bearings? 25-Oct-19 02:09 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191023_214656-DA8C7.jpg 25-Oct-19 02:09 AM I have two of these, rotating at 27 krpm 25-Oct-19 02:09 AM and the manual says to lubricate them with grease 25-Oct-19 02:09 AM no further explanation 25-Oct-19 02:09 AM and now tue question is 25-Oct-19 02:09 AM what kind of grease? 25-Oct-19 02:09 AM they're both in the foreline path of my drag, so only e-3 mbar tops 25-Oct-19 08:44 AM Ony 27k rpm? 25-Oct-19 08:46 AM aye, drag is slowish 25-Oct-19 09:18 AM @GigaSquirrel ... What a drag. 25-Oct-19 10:18 AM These are regular bearings @GigaSquirrel 25-Oct-19 10:18 AM So you just need low outgassing grease 25-Oct-19 10:18 AM PTFE? 25-Oct-19 10:18 AM looks like it has some PTFE grease inside 25-Oct-19 11:47 AM Enjoy while it’s still legal. PTFE might become unauthorized due to pollution I heard.. 25-Oct-19 11:48 AM wat ugh 25-Oct-19 11:50 AM When I worked at Pfeiffer we got an internal note about we have to find a replacement for ptfe because it’s too pollutive 25-Oct-19 11:50 AM They quote a legal text from whatever jurisdiction stating that 25-Oct-19 11:53 AM I doubt it'll affect vacuum stuff, at least hobbyist related 25-Oct-19 12:03 PM I can't imaging a general ban on PTFE. It's in so many things. 25-Oct-19 12:03 PM * imagine 25-Oct-19 04:11 PM tantalum capacitors...why must you taunt me 25-Oct-19 04:11 PM guy who sent me this board says it was working when he tested it a few years ago...but almost all the tantalum capacitors being shorted gives me doubts haha 25-Oct-19 05:05 PM they can fail offline too 25-Oct-19 06:42 PM i have just never seen them all go bad at once when it was just finicky old tantalums...until today anyway 25-Oct-19 06:42 PM usually one or two here and there that go in my experience 25-Oct-19 06:42 PM things still need some more troubleshooting but the turbo + controller are showing signs of life finally 25-Oct-19 06:42 PM $40 turbo that i got a $20 partial refund for due to the bearing falling apart during shipping (gotta love eBay)...and a gift of a controller board. cant be too annoyed for those prices 27-Oct-19 05:43 AM banning ptfe wth 27-Oct-19 07:56 AM banning PTFE? 27-Oct-19 07:58 AM y...yeah 27-Oct-19 07:58 AM as @Black Lemming wrote 27-Oct-19 08:56 AM AH, sorry, missed that comment. 27-Oct-19 08:56 AM Good luck banning PTFE 27-Oct-19 09:18 AM yeah i mean I'm shocked 27-Oct-19 09:18 AM for sure germany is the first country implementing that ‍♂️ 27-Oct-19 10:49 AM I've heard PTFE contamination is observable in like major waterbodies 27-Oct-19 10:55 AM It is! 27-Oct-19 10:55 AM But also other microplastics.... 27-Oct-19 02:33 PM What does that contamination come? I mean, I am used to have PTFE as cover in pans and sheets I machine for vacuum things. 27-Oct-19 02:33 PM Is it only industry leftovers? 27-Oct-19 02:46 PM Well it does also come from those pans 27-Oct-19 03:04 PM It comes from everywhere 27-Oct-19 03:04 PM The coatings break down into tiny particles 27-Oct-19 03:48 PM Ahh 27-Oct-19 04:06 PM Just wait till you guys learn about fluon and the super trivial uses it finds in entomology for keeping insects from escaping... https://www.bioquip.com/search/DispProduct.asp?pid=2871A 28-Oct-19 12:39 AM @Conmega how do you refinish vacuum sealing surfaces? I'm looking at turbos on ebay, thinking I want to have a small chamber for testing gizmos like the RGA and a little xray detector circuit I started years ago 28-Oct-19 12:42 AM I'd use a surface plate and mild abrasive 28-Oct-19 12:42 AM short of that, float glass will do in a pinch 28-Oct-19 12:51 AM honestly flatness isn't as important as smooth for KF/ISO really... 28-Oct-19 12:51 AM no scratches that the oring can't seal 28-Oct-19 12:51 AM a not super flat surface an oring can deal with, a scratch not really if its deep enough to see really 28-Oct-19 12:51 AM so just wet-sanding then to a polish if you want to go nuts 28-Oct-19 12:51 AM Conflat... uhm... outside of lathe work or just cutting it off an welding a new flange on... yea no 28-Oct-19 12:51 AM just use viton rings for dinged conflat if you don't care about UHV 28-Oct-19 01:08 AM how low are viton rings good for? or does it depend on the size of the ding in the conflat 28-Oct-19 09:54 AM moin!! 28-Oct-19 11:31 AM Coin! 28-Oct-19 11:31 AM Very late though. 28-Oct-19 02:27 PM @LRM it matters on your pumping speed and how much viton seals you have in the system, they do let stuff seep through better than other things, I don't have an exact figure but like 10^-8 should be easily do-able on viton with a decent sized pump for the chamber really part of the limitation is bake-out, you can't bake the chamber out as hot as you can with just copper 28-Oct-19 06:31 PM Well even bake out doesn't need to be super hot, right? You can slow bake longer at lower temps 28-Oct-19 06:31 PM My buddy baked out his ion column gun with a simple space heater pointed at it over like 5 days, turning it off at night when he wasn't around 28-Oct-19 06:33 PM hrm I am not sure about that, I thought ultimate temp also really helped with certain things 28-Oct-19 06:33 PM like I know viton your only going to bake out to just around 200 degrees F?? where as conflat with copper you can go up to like 400 degrees easy 28-Oct-19 06:34 PM I swear i just read about this on duniway stockroom re turbos or something 28-Oct-19 06:34 PM Right after my friend did it 28-Oct-19 06:34 PM I can see how going faster would be desired when you're paying a service tech 28-Oct-19 06:35 PM Bake out doesn't need to be super hot 28-Oct-19 06:35 PM Lower temp takes longer for sure. Really for orings, fresh ones can have volatiles that need to be baked out which can help, but only needed if going to very low pressures 28-Oct-19 06:35 PM They are limited to 10^-8 torr on permeation, so baking after a certain point won't help 28-Oct-19 06:35 PM Only way to go lower at that point is to chill the oring so the bulk temp drops to slow permeation, which is in part temperature dependent. 28-Oct-19 06:35 PM I just used my straight up new no baking. Few hours of pumpdown gets me to mid 10^-6 torr, faster if I have pumped the chamber prior and haven't broken to atmosphere 28-Oct-19 06:35 PM You only need super high bake out temperatures if you are trying to get to deeper UHV levels, but at that point you need all metal seals anyway 28-Oct-19 06:53 PM But it definitely helps getting down in pressure faster if you have higher pumping speed to handle the gas load. I have a pretty high speed and about as direct and short path as possible, so I can afford a bunch of orings in my system 28-Oct-19 10:10 PM I have a question for those not limited by pump selection: Which forepump is the absolute quietest? 28-Oct-19 10:10 PM From @GigaSquirrel's videos it's evident that the smaller, older Leybold Trivac pumps are quiet, but I'm wondering if there's any forepumps that(when muffled and at foreline pressure) approach whisper quietness levels that one could sleep next to 28-Oct-19 10:10 PM While the pump I have is nice and pulls quite a high vacuum, the low rumble and clacking of the vanes gets very annoying after a while 28-Oct-19 10:24 PM damn i think i have finally satisfied myself that the hall sensors in this turbo are dead...wonder if i can use the +-1ohm change in resistance to fake the pulses and get this working... probably not 28-Oct-19 10:24 PM replace em 28-Oct-19 10:24 PM they're very simple inside, usually just sticking into the rotor's path 28-Oct-19 10:26 PM i had heard that the ones in this pump, TPU050, are potted in epoxy 28-Oct-19 10:27 PM I can see the windings of the rotor through the exhaust port of my TPH-062 28-Oct-19 10:27 PM the 050 is older but it should be similar in construction 28-Oct-19 10:28 PM i am hesitant to open it up and mess around too much but i suppose i do not have a whole lot to lose at this point 28-Oct-19 10:28 PM mark the rotor positions 28-Oct-19 10:28 PM screws, housing rotation 28-Oct-19 10:28 PM the manual i have does not have much information on disassembly and i think this has a one piece rotor 28-Oct-19 10:29 PM I think it does, yeah 28-Oct-19 10:29 PM with stator rings 28-Oct-19 10:29 PM most of the disassembly info is about changing the bearing 28-Oct-19 10:29 PM ah 28-Oct-19 10:29 PM does yours clunk when you flip it upside down? 28-Oct-19 10:31 PM https://i.gyazo.com/9f99962ea0dda3b8091c1c1d0f11ed49.png 28-Oct-19 10:31 PM hmm maybe it just lifts off 28-Oct-19 10:31 PM yes it does 28-Oct-19 10:31 PM see if you can see the windings through the exhaust port 28-Oct-19 10:33 PM they are 28-Oct-19 10:33 PM not potted then 28-Oct-19 10:33 PM wonder if i undo the screws marked 10 on that diagram if the top lifts off the windings 28-Oct-19 10:34 PM the housing will start to lift off 28-Oct-19 10:34 PM the top... pipe, essentially 28-Oct-19 10:34 PM be careful though, the rings are fragile 28-Oct-19 10:36 PM guess i will give that a look in a bit...see what exactly i am dealing with on the hall sensors 28-Oct-19 10:36 PM nice of them to include the oring sizes in the manual 28-Oct-19 10:36 PM they're antique and very easy to kill 28-Oct-19 10:36 PM I semi-killed mine 28-Oct-19 10:36 PM the weirdest part is they still put out a resistance change of +-1ohm just no signal when they are powered up 28-Oct-19 10:37 PM they're not meant to be driven with current 28-Oct-19 10:37 PM 5V, ground, and they output a differential...ish 28-Oct-19 10:37 PM signal 28-Oct-19 10:38 PM datasheet i found says 4.5v to 18v input and then yeah a differential sort of signal 28-Oct-19 10:39 PM the way the original controller works is that there's just a BCD decoder that's fed by two comparators, which are in turn fed directly by the differential output of the halls 28-Oct-19 10:39 PM problem is mine only puts out an unchanging 0.1v and 0.3v on the two sensors outputs 28-Oct-19 10:39 PM the BCD decoder just drives four fets 28-Oct-19 10:39 PM no sign of it even recognizing the magnets 28-Oct-19 10:39 PM yeah i have the schematic for the controller and a board i was given with the relevant bits to drive it 28-Oct-19 10:39 PM just the hall sensors are the sticking point 28-Oct-19 10:40 PM I had to figure it out all myself, and then got a schematic 28-Oct-19 10:40 PM ouch 28-Oct-19 10:40 PM hmm i was checking back on my paypal history and it looks like i actually got a full refund for the turbo anyway 28-Oct-19 10:41 PM damn, lucky 28-Oct-19 10:41 PM so i am not out any money even if i royally mess it up 28-Oct-19 10:41 PM I paid close to $300 for mine 28-Oct-19 10:42 PM yeah the seller said it still spun and stuff...but when it arrived the rotor was frozen up. got a new bearing that i am sort of experimenting with ($5 chinese ceramic) and everything spins really nicely with a fingertip 28-Oct-19 10:42 PM i didnt even ask for the refund just asked if it spun before shipping 28-Oct-19 10:42 PM original price was.... $40 28-Oct-19 10:43 PM ... was the seller... Canadian? 28-Oct-19 10:43 PM no, fairly local to me in california 28-Oct-19 10:43 PM Alright, felt similar 28-Oct-19 10:43 PM I might have a nice deal on a vintage-ish CF pump that spins 28-Oct-19 10:43 PM Well, I do, but shipping is a pain and they're figuring it out 28-Oct-19 10:44 PM nice, in good working order or mystery buy? 28-Oct-19 10:44 PM "spins freely with no noise or grinding" is what I got so far 28-Oct-19 10:44 PM for the money that's good to me 28-Oct-19 10:44 PM thats what mine was sold as lol 28-Oct-19 10:44 PM "spins maybe not as freely as it should" 28-Oct-19 10:44 PM something like that 28-Oct-19 10:45 PM that's a red flag 28-Oct-19 10:45 PM dying bearing 28-Oct-19 10:45 PM yeah for $40 i wasnt too worried about it 28-Oct-19 10:45 PM the unexpected refund made it even more painless 28-Oct-19 10:45 PM I really want a turbodrag pump 28-Oct-19 10:46 PM i have not seen a ton of those on ebay but it is possible i just did not notice 28-Oct-19 10:46 PM They're bad for large volumes, but perfect for making vacuum tubes that can suddenly go from sub-mbar to 1 bar 28-Oct-19 10:46 PM since they survive running in air 24/7 28-Oct-19 10:47 PM always wanted to see how they machine the bore of those things 28-Oct-19 10:47 PM ... pipe? 28-Oct-19 10:47 PM ive seen a few that had a sort of spiral milled pattern in the outer wall 28-Oct-19 10:48 PM that's the easy bit 28-Oct-19 10:48 PM the inside... 28-Oct-19 10:48 PM we could ask @Black Lemming who worked at Pfeiffer and is also selling a turbodrag 28-Oct-19 10:49 PM was looking for a photo of it but then i remembered i think it was on here that i saw the most recent one 29-Oct-19 12:40 PM @Deleted User why would the vac tubes go from sub-mbar to 1 bar so quick? a broken piece of glass? 29-Oct-19 12:41 PM yeah, if it shatters during pumpdown/bakeout/getter flashing/sealing 29-Oct-19 01:14 PM sooo, scroll pumps vs diaphram? 29-Oct-19 01:14 PM I'd say scroll 29-Oct-19 01:14 PM but it's also $croll 29-Oct-19 01:15 PM +1 29-Oct-19 01:16 PM I read an article (trying to sell scroll pumps) and it said diaphram are less reliable, higher pressure, and harder to maintain/rebuild 29-Oct-19 01:16 PM but yeah, $croll 29-Oct-19 01:16 PM correct 29-Oct-19 01:16 PM a used scroll pump is generally over $1000 29-Oct-19 01:16 PM usually over $2000-2500 29-Oct-19 01:16 PM a good, modern scroll pump is closer to $3-5k 29-Oct-19 01:16 PM they're very much a non-ancient tech 29-Oct-19 01:17 PM seems like if I want to do some semiconductor, or at least precision coating stuff, precision etching stuff... oil contamination would best be avoided... 29-Oct-19 02:23 PM maybe add in a big cold trap between your pump and the coating chamber 29-Oct-19 02:23 PM the brute force solution 29-Oct-19 02:23 PM @Deleted User opened up my TPU-050 today and...the hall sensors are potted 29-Oct-19 02:23 PM not what i wanted to find inside my turbo 29-Oct-19 02:24 PM gouge them out! 29-Oct-19 02:24 PM cut off enough potting to pull them out, put in a tiny sot23 hall sensor in, dab a bit of epoxy in 29-Oct-19 02:25 PM not sure that is possible but i am going to think about it a bit 29-Oct-19 02:25 PM you can also just add your own elsewhere 29-Oct-19 02:25 PM modern hall sensors are very sensitive and will work at longer distances 29-Oct-19 02:25 PM think creatively :P 29-Oct-19 02:26 PM i still think it might be possible to rig up a resistance based sensor with the way these failed 29-Oct-19 02:26 PM i get a very consistent +-1ohm change in them 29-Oct-19 02:26 PM just not sure if it would change fast enough or be readable fast enough to be a viable signal 29-Oct-19 02:26 PM https://i.gyazo.com/bf889690bf4d37ff26b87de94e22ae0b.jpg 29-Oct-19 02:26 PM i think this is one of the sensors https://i.gyazo.com/a8d1b10d13cb5dc80a2e0cacb5fff545.jpg 29-Oct-19 02:29 PM I wouldn't bother 29-Oct-19 02:29 PM there's enough space under it for a tiny SOT23 sensor 29-Oct-19 02:29 PM right above the stator poles 29-Oct-19 02:33 PM hmm... could be, i didnt measure the gap 29-Oct-19 02:36 PM you can definitely figure out how to stuff something in there 29-Oct-19 02:36 PM if a sot23 doesn't fit, you can go even smaller 29-Oct-19 02:36 PM DFN or even WLCSP 29-Oct-19 02:36 PM 0.5mm on the side 29-Oct-19 02:36 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/BGA_6_t-593BF.png 29-Oct-19 02:42 PM dead bugging that must suck 29-Oct-19 02:42 PM @Deleted User which side? 29-Oct-19 02:42 PM that's just an example of a wlcsp 29-Oct-19 02:42 PM there's square hall sensors that are about as wide as that one is tall 29-Oct-19 02:42 PM 2x2 pins 29-Oct-19 02:44 PM :D 29-Oct-19 02:44 PM I guess those are for use in cellphones or something 29-Oct-19 02:52 PM yep, tiny stuff 29-Oct-19 03:40 PM @LRM maybe a wheatstone bridge to amplify that resistance difference 29-Oct-19 08:38 PM So i need a way to detect if I've drilled nanopores through silicon chips, inside the fib 29-Oct-19 08:38 PM I was thinking well maybe I could have a separate charge sensor, separate from the stage ground, below the chip that was smaller than the chip so when I punched a hole through the chip, the sensor would start reading and presenting a signal 29-Oct-19 08:38 PM Alternatively I was thinking that I could have a gas source below the chip bonded or sealed to the chip with an o-ring and when the nanopore was etched I would see a vacuum leak or potentially using my RGA sniff the type of gas, say some sort of carbon 29-Oct-19 08:38 PM Or use an xray dosimeter below the chip, sensor smaller than the chip, and watch for auger emissions out the backside of the chip indicating I was close to drilling all the way through 29-Oct-19 08:38 PM I'm not quite sure which direction to think hard about actually implementing 29-Oct-19 08:47 PM I'd put a charge sensor under it 29-Oct-19 09:23 PM I wonder if I could just use the faraday cup that's already built in 29-Oct-19 11:58 PM https://www.lesker.com/newweb/chambers/aluminum-chambers.cfm 29-Oct-19 11:58 PM why aren't we talking more about using aluminum? 30-Oct-19 12:00 AM because i havent gotten my turbo running 30-Oct-19 12:00 AM or taken photos of the aluminum i was given 30-Oct-19 12:00 AM well, I mean, I always hear about stainles being used for vacuum chambers 30-Oct-19 12:00 AM think that is because it can be brazed or welded 30-Oct-19 12:00 AM but aluminum you basically have to go with welding or orings 30-Oct-19 12:01 AM Al can be used just as well, but for DIY stainless is waaaay easier, because welding Al tight is hard(er) 30-Oct-19 12:01 AM and stuff like CF can't be made of Al 30-Oct-19 12:01 AM not with that attitude 30-Oct-19 12:02 AM Al is way easier to machine at home 30-Oct-19 12:02 AM it all has it's advantages and disadvantages 30-Oct-19 12:04 AM oh so the welding is harder, hmm 30-Oct-19 12:07 AM my experience with welding al is extremely limited but the main thing seemed to be surface prep 30-Oct-19 12:07 AM if it is not scrupulously clean you will have a big mess and not much else 30-Oct-19 12:08 AM it's not that extreme, but it's very important 30-Oct-19 12:08 AM plus, if you have surface contamination in SS you can just push it into the puddle, resulting in some inclusion but it's still tight 30-Oct-19 12:08 AM with Al if you have some contamination it's grinding time 30-Oct-19 12:08 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/EHgNyuWX4AQHBXi-13A21.png 30-Oct-19 12:10 AM oh man, searching 'stainless plate' on craigslist brought this up https://portland.craigslist.org/clk/app/d/vancouver-viking-36-professional/6995909509.html 30-Oct-19 12:10 AM that would be pretty sweet if it could be sealed up as a vacuum chamber 30-Oct-19 12:14 AM well the geometry is close to worst-possible 30-Oct-19 12:14 AM you want as few flat surfaces as possible 30-Oct-19 12:14 AM it's basically an inverse pressure container, and the pressure of just one atmosphere can really add up 30-Oct-19 12:14 AM 1 atm is ~1 kg/cm² 30-Oct-19 12:14 AM the offer mentions 36" somewhere 30-Oct-19 12:14 AM let's say it's 90x90 cm 30-Oct-19 12:14 AM =>8100 cm², roundabout 8 tonnes 30-Oct-19 12:43 AM from top and bottom each, trying to turn the thing into a pancake 30-Oct-19 12:45 AM i was just thinking about that 30-Oct-19 12:45 AM first is how far could you go before implosion 30-Oct-19 12:45 AM second is how would that go down 30-Oct-19 12:57 AM some mbar maybe, at some point it doesn't really matter anymore 30-Oct-19 12:57 AM if you're at e-4 or e-8, you're still at one bar difference 30-Oct-19 12:57 AM and reinforcement 30-Oct-19 03:30 AM Nano text debugging, destined for roll-to-roll imprint lithography 30-Oct-19 03:30 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191030_010423-EEC1A.jpg 30-Oct-19 03:30 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191030_030222-918F8.jpg 30-Oct-19 03:30 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191030_010345-0EE9A.jpg 30-Oct-19 03:49 AM Woooow 30-Oct-19 03:54 AM Here's a pretty smudged one, there are some sections that are nearly pristine 30-Oct-19 03:54 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/5-1-E2B8F.jpg 30-Oct-19 03:54 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/25-D03EE.jpg 30-Oct-19 03:54 AM Something bad happened there... Which is what I need to figure out how to prevent/avoid 30-Oct-19 10:50 AM བོད་ 30-Oct-19 10:50 AM This is Tibetan mantra for Om-mani-Peme-houm-(hhri) ! 30-Oct-19 11:06 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-85D26.png 30-Oct-19 11:16 AM good job! 30-Oct-19 11:17 AM This is actually not really Tibetan though 30-Oct-19 11:17 AM It’s Brahamin’s hindi Sanskrit transliterated in Tibetan sanskrit xD 30-Oct-19 11:17 AM That’s the reason why the ནི ( NI) lettre is horizontally flipped 30-Oct-19 11:20 AM I...only see a mouse and a chernobyl cat portrait... 30-Oct-19 11:20 AM It must be me that I'm weird. 30-Oct-19 11:20 AM All letters are pronounced somehow ending with an « Ahh » sound 30-Oct-19 11:20 AM Ka, Kha, Ga, Nga... etc 30-Oct-19 11:20 AM The diacritic accents on letters changes the sound « A » in « I » or « Ou » or « O » or « E » 30-Oct-19 11:20 AM ི = i 30-Oct-19 11:20 AM ན = na, add ི on it and you have ནི ni 30-Oct-19 11:24 AM mantra lithography, that's awesome 30-Oct-19 11:24 AM Whatever if you are interested in leaning Tibetan ask me xD I created a French site for learning if you happen to talk French xD ( http://www.montibet.com ) 30-Oct-19 11:24 AM Lithography at this scale is insanely great ! 30-Oct-19 11:29 AM What is the end use of the tiny lithography like that? 30-Oct-19 11:30 AM @LRM presumably there's a prayer-wavelength 30-Oct-19 11:30 AM I must be in the wrong channel, I thought I came here for high vacuum hehehe 30-Oct-19 11:30 AM @Black Lemming my wife learned Sanskrit when she was growing up in India, but not sure she knows a lot about Tibetan usage 30-Oct-19 11:30 AM man language stuff is above my head, I was just learning how to play with vacuum tubes last night hah 30-Oct-19 11:32 AM @LRM in general, some folks think printed prayers send good vibes out into the universe when rotated 30-Oct-19 11:32 AM Amplified anything interesting, @Conmega ? 30-Oct-19 11:32 AM (like, got a picture of a tube working, or smt) 30-Oct-19 11:33 AM That’s the thing with the prayer flags, which in Tibetan are called somehow « Wind-horses » 30-Oct-19 11:33 AM The inverse-lorentz force for prayers 30-Oct-19 11:33 AM @nmz787 Interesting. Not my kinda thing but interesting for sure 30-Oct-19 11:33 AM But it’s about vacuum here not vacuity xD 30-Oct-19 11:33 AM oh I litterally just used a VT-121 triode acorn tube to blink an led feeding it a square wave and just hooking the other side to an LED, really stupid use but hehe 30-Oct-19 11:33 AM Haha 30-Oct-19 11:34 AM I want to play with digital logic and tubes not radio stuff really 30-Oct-19 11:34 AM I do collect computers and computer artifacts 30-Oct-19 11:34 AM The plasmod plasma chamber I got a tour of how to use yesterday used tubes 30-Oct-19 11:34 AM The inductive coupling coil was literally just sitting next to the quartz tube, not even wrapped around it, I was surprised by that 30-Oct-19 11:35 AM hehe 30-Oct-19 11:37 AM Where's a good source on tubes for high voltage control, and I guess in the RF freq range? 30-Oct-19 11:37 AM Is there a good catalog anywhere with a nice table of info? 30-Oct-19 11:37 AM Or do I need to do a lot of correlation myself? 30-Oct-19 11:37 AM I.e. search ebay, lookup each part number until I find a match to my needs? 30-Oct-19 11:37 AM Also, is the solid state substitute IGBT? 30-Oct-19 11:38 AM uhm yea I think most tube stuff nowadays is people just learning about them through others 30-Oct-19 11:38 AM Or is there no modern substitute 30-Oct-19 11:39 AM I have a friend who is a big tube nut, he has had 1 million watt sunburst tubes 30-Oct-19 11:39 AM uhm I think for high wattage tubes are still basically best but there are beginning to be new silicon replacements that are getting close 30-Oct-19 11:39 AM if you ever have to look a tube up 30-Oct-19 11:39 AM http://www.nj7p.org/Tubes/SQL/Tube.php 30-Oct-19 11:39 AM one of the best databases 30-Oct-19 01:11 PM Oh, cool, thanks 30-Oct-19 01:45 PM Don't TV stations still broadcast using tubes? Klystron tubes or whatever... 30-Oct-19 01:54 PM Some analog ones used to 30-Oct-19 01:54 PM And likely still do in places with analog tv and especially in poor old ex-soviet republics. 30-Oct-19 01:54 PM DVB-T is just tons of solid state units in parallel 30-Oct-19 03:25 PM @Conmega that's more tubes than I have made work! A photo/gif would have been nice 30-Oct-19 03:25 PM I took a video but honestly I had a few different circuits in view at the time so its a bit confusing to understand how everything is connected hehe... need to make an actual tube breadboard and play some more with tubes later 30-Oct-19 03:25 PM Because coolness. 30-Oct-19 03:25 PM 30-Oct-19 03:25 PM Well, hotness, because filaments. XD 30-Oct-19 03:25 PM Would be interesting to make a simple pcb tube driver for tube explanations. Like a few tube examples driveable/interconnectable to do simple things. 30-Oct-19 03:28 PM hard to see in the one photo I took... its a tiny tube hehe 30-Oct-19 03:28 PM Absolutely imprqctical, of course. 30-Oct-19 03:28 PM Oh I am sure people have done that a million times over 30-Oct-19 03:29 PM 1.000.001, yes. 30-Oct-19 03:29 PM https://media.discordapp.net/attachments/424014648757452800/639228868871323677/DSC_2873.JPG 30-Oct-19 03:29 PM here tiny tube off to the left under my shadow to see the glow 30-Oct-19 03:29 PM one of these little guys 30-Oct-19 03:29 PM http://www.r-type.org/pics/aai0058.jpg 30-Oct-19 03:29 PM acorn tube 30-Oct-19 04:07 PM oh no it's so cute 30-Oct-19 06:09 PM Neat! 30-Oct-19 09:43 PM Lovely! Never saw one tube in that shape before. 30-Oct-19 11:28 PM dang these hall sensors pfeiffer used are weird with 4 leads...going to be fun finding replacements 30-Oct-19 11:41 PM anyone know a hall sensor with Vin, gnd, +Out, and -Out off the top of their heads? 30-Oct-19 11:41 PM why not build an external adapter board? 30-Oct-19 11:41 PM I'd go all the way and replace the very antiquated controller 30-Oct-19 11:42 PM well i already have the controller...if i can just replace the hall sensors that would be the easiest option. 30-Oct-19 11:42 PM there's also a part number in the manual for the TPH series 30-Oct-19 11:42 PM find an alternative to that - I recall one clearly existing 30-Oct-19 11:43 PM hmm i will check the manuals i have but i do not remember a part number for the hall sensor 30-Oct-19 11:43 PM it was all potted in epoxy 30-Oct-19 11:45 PM I believe this is what is used 30-Oct-19 11:45 PM http://pdf.dzsc.com/2008711/200807110908552757.pdf 30-Oct-19 11:45 PM probably two in tandem 30-Oct-19 11:46 PM there are two hall sensors 90deg from each other but i do not believe it is one of those 30-Oct-19 11:47 PM you should be able to replace it with any single-ended sensor by tacking on a voltage offset 30-Oct-19 11:47 PM so that the comparators always see a positive or negative swing relative to the virtual rail 30-Oct-19 11:48 PM i was considering that, finding a direct replacement is my first choice though 30-Oct-19 11:48 PM https://i.gyazo.com/da624e5aa6921f7a1287ca9cb289db7c.jpg 30-Oct-19 11:48 PM dont mind the mess of epoxy 30-Oct-19 11:48 PM they had a very thin PCB that was put in there and then potted into epoxy 30-Oct-19 11:48 PM so thats actually the bottom of the sensor 30-Oct-19 11:50 PM that looks gnarly 30-Oct-19 11:50 PM it's unlikely you'll find a drop in replacement 30-Oct-19 11:50 PM actually, now that I think about it 30-Oct-19 11:50 PM yeah, you should be totally fine with just putting a small static offset on the negative rail 30-Oct-19 11:50 PM https://www.electronicshub.org/wp-content/uploads/2015/09/Hall-Effect-Integrated-Circuit-IC-Sensors.jpg 30-Oct-19 11:50 PM thats what i need 30-Oct-19 11:50 PM now if only they had left the freaking part number! 30-Oct-19 11:51 PM something like 1.8V or whatever, from a regular voltage reference 30-Oct-19 11:51 PM I would do that for ease, really 31-Oct-19 02:03 PM I was just thinking about turbo drag pumps again, and thinking about testing old equipment (i.e. my surplus RGA) or stuff I might try making (feedthroughs, gas injectors)... I might really benefit from a drag pump's survivability to atmosphere 31-Oct-19 02:03 PM yep 31-Oct-19 02:03 PM or an oildiff 31-Oct-19 02:03 PM with silicone oil 31-Oct-19 02:03 PM can survive atmosphere just fine, you might have to do some cleaning afterwards 31-Oct-19 02:04 PM yeah, that's why I want a drag 31-Oct-19 02:04 PM for glassblowing 31-Oct-19 02:04 PM they don't get damaged or burn up 31-Oct-19 02:04 PM heh I was thinking about the same 31-Oct-19 02:04 PM slow pumping is fine for small tubes and a fail doesn't matter 31-Oct-19 02:05 PM our hopes are in lemming dragging out a bin of "scrap" turbos from pfeiffer 31-Oct-19 02:05 PM or sellers coming down in price on the MDP 5011s 31-Oct-19 02:08 PM this one looks pretty strange https://www.ebay.com/itm/PFEIFFER-TMH-260-130-2P-TURBO-DRAG-TURBOMOLECULAR-VACUUM-PUMP-CONTROLLER-TCP120/362791289918 31-Oct-19 02:08 PM it's molecular 31-Oct-19 02:08 PM two stage, probably for a mass spec 31-Oct-19 02:08 PM they're all molecular 31-Oct-19 02:09 PM drag is cheating 31-Oct-19 02:09 PM but this one is turbo, not drag 31-Oct-19 02:09 PM https://www.ebay.com/itm/Alcatel-Adixen-MDP-5011-Turbo-Pump/303322538448 31-Oct-19 02:09 PM these are drag 31-Oct-19 02:10 PM yep 31-Oct-19 02:14 PM @GigaSquirrel what do you mean it's not drag, is the title of the listing wrong? 31-Oct-19 02:14 PM yep 31-Oct-19 02:14 PM there's two types of pump in a modern turbomolecular pump 31-Oct-19 02:14 PM the top section is a turbomolecular section, which is an angry fan that shoves the molecules down 31-Oct-19 02:14 PM but below that is usually a howleck stage, which increases the foreline pressure a lot and lets turbos vent easier 31-Oct-19 02:15 PM holweck is a type of drag, just so we're all talking the same 31-Oct-19 02:15 PM https://gigabecquerel.wordpress.com/2019/10/22/molecular-drag-vs-turbomolecular-pump/ 31-Oct-19 02:15 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/1-s2-43513.png 31-Oct-19 02:15 PM and this is what modern pumps are usually like 31-Oct-19 02:15 PM sometimes it's in reverse 31-Oct-19 02:15 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/n-o-dsc-6572-rgb1-C12D1.png 31-Oct-19 02:16 PM yep 31-Oct-19 02:16 PM the rotor is smooth, the spiral is on the body 31-Oct-19 02:16 PM the top part of a turbomolecular pump can't survive venting to air 31-Oct-19 02:16 PM the bottom drag stage doesn't care 31-Oct-19 02:17 PM huh, so basically a pure-drag has howleck+spiral... and the turbo-drag has turbo+howleck 31-Oct-19 02:17 PM howleck is spiral 31-Oct-19 02:17 PM a pure drag pump usually has one set of very tiny molecular fins at the top 31-Oct-19 02:17 PM to get it started and create a tiny pressure 31-Oct-19 02:17 PM then the rest of the pump is just a thin spiral spinning very close to the housing 31-Oct-19 02:17 PM essentially just dragging the molecules down with friction 31-Oct-19 02:17 PM a pure turbomolecular pump only has the turbine stage 31-Oct-19 02:17 PM but that requires a good forepump 31-Oct-19 02:17 PM it doesn't require a special forepump, but the foreline pressure must be low 31-Oct-19 02:20 PM but! The turbines in a drag work like a fan, while the turbines in a turbo do not 31-Oct-19 02:20 PM (unless you vent to air) 31-Oct-19 02:20 PM (angry turbine noises) 31-Oct-19 02:20 PM welll 31-Oct-19 02:21 PM varian/agilent also make this weird third type 31-Oct-19 02:21 PM the siegbahn pump 31-Oct-19 02:21 PM they call it macro-torr 31-Oct-19 02:21 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/turbomolecular20vacuum20pumps201-DD9F4.png 31-Oct-19 02:23 PM guess they had some hard disks left over 31-Oct-19 02:23 PM but it's interesting to see that 31-Oct-19 02:23 PM I only knew holweck so far 31-Oct-19 02:26 PM oh, I've seen those macro-torr pumps 31-Oct-19 02:26 PM on ebay 31-Oct-19 02:26 PM are they also OK with atmosphere? 31-Oct-19 02:26 PM Siegbahn sounds like some 1940es german propaganda... 31-Oct-19 02:28 PM @nmz787 nope! Just more tolerant to higher foreline pressure, like a few mbars 31-Oct-19 02:28 PM everything with a turbo stage is no good for atmosphere 31-Oct-19 02:32 PM soo do you think this setup is worth $900 (shipped) ? https://www.ebay.com/itm/Alcatel-Drytel-31-Pumping-Station-Please-View-Video-Of-Unit-Working/372752711671 31-Oct-19 02:32 PM this is the closes manual I can find www.idealvac.com/files/manualsII/Alcatel_Drytel_100_Instruction_Manual.pdf 31-Oct-19 02:33 PM depends on how much it is worth to you 31-Oct-19 02:33 PM "The MDP has 2 ball bearings: at every relubrication (see fig. 5/1 and 5/2) schedule, the user mustrelubricate the two ball bearings ." 31-Oct-19 02:33 PM do you need a drag 31-Oct-19 02:33 PM "You mustuse only the grease contained in the syringe available from Alcatel." 31-Oct-19 02:33 PM well, I don't want to kill a turbo and potentially hurt myself in doing so 31-Oct-19 02:33 PM if some crappy feedthrough I build fails during testing 31-Oct-19 02:33 PM and a gas injector I build accidentally opens wayy too much 31-Oct-19 02:34 PM https://gigabecquerel.wordpress.com/2019/06/02/quick-n-dirty-vacuum-feedthrough/ Build a feedthrough like this 31-Oct-19 02:35 PM well I might need like 10 or 20 pins 31-Oct-19 02:35 PM idk at this point 31-Oct-19 02:35 PM also depends on power levels 31-Oct-19 02:35 PM sensors vs power 31-Oct-19 02:35 PM that system being 'ready to go' aside from knowing if it's in good health is a nice thing 31-Oct-19 02:35 PM wth are your plans 31-Oct-19 02:35 PM proof-of-concept fab stuff 31-Oct-19 02:35 PM I wanna get an SEM going on my FIB chamber so I have a dual beam 31-Oct-19 02:35 PM at least 31-Oct-19 02:35 PM but also want to add on an RGA for correlative secondary ion microscopy 31-Oct-19 02:35 PM and then adding in-chamber camera, maybe some stage/electro-mechanical stuff 31-Oct-19 02:35 PM my own faraday cup/ion/charge detector 31-Oct-19 02:35 PM but not knowing if I can get "grease contained in the syringe available from Alcatel." is worrisome 31-Oct-19 02:35 PM but I'm so new to all these pumps... so I don't know if that's going to be easy or impossible 31-Oct-19 02:45 PM you don't need an extra pump to add extra volume to your fib 31-Oct-19 02:45 PM not at all 31-Oct-19 02:45 PM I want to have test rig for stuff 31-Oct-19 02:47 PM it's probably not worth $900 31-Oct-19 02:47 PM if you just want a drag, lemming here is selling one 31-Oct-19 02:47 PM https://www.ebay.com/itm/Turbo-Molecular-MDP-5011/193177545837? 31-Oct-19 02:47 PM it's out of my price range, but at least we know it's actually functional 31-Oct-19 02:57 PM bit late to the party but there is a good illustration of the original siegbahn type of drag pump here https://archive.org/details/HighVacuumPumpingEquipment/page/n103 31-Oct-19 02:57 PM reminded me of the talk of the tesla turbine concept people were talking about awhile ago but probably far more workable 31-Oct-19 02:58 PM we could always crowdfund a 5 axis desktop mill 31-Oct-19 02:58 PM ;) 31-Oct-19 02:58 PM make our own turbos and turbodrags 31-Oct-19 02:59 PM you could probably do the siegbahn style with just a regular cnc mill and a manual lathe... 31-Oct-19 02:59 PM it would also not suck 31-Oct-19 02:59 PM which is a bad thing in this case 31-Oct-19 04:40 PM psst @GigaSquirrel , have you done any kinda writeup of your oil changing adventures? i have a similar varian turbo with an oil cup where the oil's gone all dark-brown and gross on me >.> 31-Oct-19 04:40 PM i'd like to flush it clean first if possible, wondering if/hoping the answer is something like 'dump fun solvents through it until it runs clear' or something similarly lazy :D 31-Oct-19 05:01 PM called pfeiffer sales rep for my area, couldn't tell me immediately if the Drytel 31 parts were available, but did say he had one of these I could borrow if my process was clean enough: https://www.pfeiffer-vacuum.com/en/products/vacuum-generation/pumping-stations/turbo-pumping-stations/hicube-eco/20020/hicube-80-eco-dn-63-iso-k-mvp-015-4 31-Oct-19 05:01 PM now idk for how long, butttt 31-Oct-19 05:02 PM ooooh 31-Oct-19 05:08 PM and he said it could survive hitting atmosphere... not a lot of atmosphere, but he said it would start to overheat and shutdown, so nothing catastrophic 31-Oct-19 05:08 PM $5k new 31-Oct-19 05:16 PM your rep can just let you... borrow.. one? 31-Oct-19 05:42 PM The rep I just cold called earlier, yeah apparently 31-Oct-19 06:00 PM most reps for scientific stuff here are in Russia 31-Oct-19 06:00 PM and they're the driest, most stone cold, useless companies 31-Oct-19 06:00 PM "Oh you're interested in that thing... hand over your entire life history and sign this document promising you'll buy 10 000 of it tomorrow. Now see that kitten? Kill it." 31-Oct-19 06:00 PM I may or may not have added that last bit in 01-Nov-19 01:03 AM @qualia Don't worry, I will report my findings! I am not yet happy with the mix I have, once I get that done I will write sth 01-Nov-19 02:30 AM Joined the server. 01-Nov-19 06:44 AM Welcome, Igor! 01-Nov-19 09:15 AM when buying kapton tape anyone have preferred brands? 01-Nov-19 09:55 AM @Nixie thanks, hello too 01-Nov-19 11:13 AM @LRM I just use "Koptan" from ebay, but compared to the stuff I had at work from Farnell the adhesive is inferior. 01-Nov-19 11:13 AM Still usable for my hobby uses. 01-Nov-19 11:13 AM And the Farnell stuff was ok at 10^-7 mBar and 90K 01-Nov-19 11:37 AM Wow 01-Nov-19 04:58 PM there are also low outgassing kapton Tapes those polyimide tapes have acrylic or even silicone adhesive, 1×10-9 Torr is no problem, the stuff from Digikey and Farnell works quite well 01-Nov-19 10:24 PM Just a regular Friday night... 01-Nov-19 10:24 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191101_222358-5A3A4.jpg 01-Nov-19 10:26 PM the angry dishwasher 01-Nov-19 10:26 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191101_221625-EE9AB.jpg 01-Nov-19 10:26 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191101_221751-3B995.jpg 01-Nov-19 10:26 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191101_221751-9C794.jpg 01-Nov-19 11:30 PM https://youtu.be/TtuUANbaEFI 02-Nov-19 12:15 AM Smoothing mechanically milled features in aluminum with a FIB is a no-go, at least for average scale machine tooling marks 02-Nov-19 12:15 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191102_001323-887C3.jpg 02-Nov-19 12:15 AM Maybe with some machine vision but not manually 02-Nov-19 12:15 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191102_001654-D13FD.jpg 02-Nov-19 10:00 AM I recall andrew zonenberg lapping a cut/milled chip with different grits of diamond lapping paste to be able to see the different layers (sidewalls) 02-Nov-19 10:00 AM mainly for thicknesses and ID what metal layers were used 02-Nov-19 12:45 PM Yeah 02-Nov-19 12:45 PM He did it recently with a capacitor too, for @Applied_Ion 02-Nov-19 12:53 PM I should invite azonenberg here 02-Nov-19 12:53 PM but I don't think he uses discord 02-Nov-19 01:26 PM I am in at least one IRC room with him 02-Nov-19 01:26 PM He's on my Facebook too, so I guess he may not be opposed 02-Nov-19 01:33 PM I'm also in at least one IRC room with him 02-Nov-19 01:33 PM but not in the same one as you 02-Nov-19 03:46 PM https://hackaday.io/project/1129-openexposer 02-Nov-19 03:46 PM I wonder if that thing would be useful for this crowd 02-Nov-19 03:50 PM seems quite pointless to do this 02-Nov-19 03:50 PM you can buy SLA printers really cheap nowadays 02-Nov-19 03:50 PM and just expose the PCB as a single layer print 02-Nov-19 03:56 PM Heya that's a neat idea I did not think of. 02-Nov-19 03:57 PM doesn't seem like many have, I only saw one video of someone doing it 02-Nov-19 03:57 PM (successfully) 02-Nov-19 03:57 PM I'll have to mention that to the friend who's contemplating buying an SLA printer. 02-Nov-19 03:57 PM you can usually just remove the thin floor vat and leave the LCD screen there directly 02-Nov-19 03:57 PM place the PCB on there, a book of weight, and print your PCB for a few minutes 02-Nov-19 07:02 PM going to be honest... why does anyone make PCBs at home anymore, its SO DARN CHEAP 02-Nov-19 07:02 PM Even if I just need a single board for something I just order boards lol 02-Nov-19 07:06 PM instant gratification 02-Nov-19 07:06 PM because sometimes you can't wait two weeks for them to arrive 02-Nov-19 07:06 PM because sometimes keeping IP in house is important 02-Nov-19 07:07 PM 6 days flat every time for me 02-Nov-19 07:07 PM you're not the entire world 02-Nov-19 07:07 PM that is a fair point, but if IP is a massive concern you probably have lawyers which means you can afford a real board process lol 02-Nov-19 07:07 PM not always 02-Nov-19 07:07 PM small hobbyist designs a thing, doesn't want it cloned 02-Nov-19 07:07 PM it takes a month to get PCBs from china here, unless I pay through the nose for express shipping and manufacture 02-Nov-19 07:08 PM there are genuinely good board houses that aren't JLCPCB that you can probably get contracts for that stuff about that aren't stupid expensive either 02-Nov-19 07:08 PM sure, but in China? 02-Nov-19 07:08 PM Hours vs. days for a one off board is attractive. 02-Nov-19 07:08 PM iphones keep falling off production lines 02-Nov-19 07:08 PM I'm sure apple is paying for the best 02-Nov-19 07:09 PM so sure if your in uganda I guess there is nothing in the country, but most mainland countries at this point seem to have some form of fab house 02-Nov-19 07:09 PM Even more, if you do ANYTHING on higher frequencies, cheap and fast just does not happen 02-Nov-19 07:09 PM its hard to find one that isn't just looking to do government contracts and charge a million bucks sure, but they exist 02-Nov-19 07:09 PM But roger's etch just like fr4 does 02-Nov-19 07:09 PM to be fair @rfs you're not going to do a controlled impedance rogers board at home 02-Nov-19 07:09 PM lol 02-Nov-19 07:09 PM just etching ain't enough in that case 02-Nov-19 07:10 PM Still gona get less loss than fr4 02-Nov-19 07:10 PM I think he meant faster design iterations 02-Nov-19 07:10 PM design iterations don't matter if none of your iterations work 02-Nov-19 07:10 PM ah no ok you meant like 4 layer higher freqency stuff 02-Nov-19 07:10 PM yeah 02-Nov-19 07:10 PM then again, I have been looking at a friend working with thin ebay sourced teflon laminate 02-Nov-19 07:10 PM 4 layer is not necessary for HF 02-Nov-19 07:10 PM and now trying to reverse what laminate it actually was. 02-Nov-19 07:10 PM in fact 1 layer is often much better 02-Nov-19 07:10 PM Yep 02-Nov-19 07:10 PM But when you want 0.4mm thick teflon for a hobby project... 02-Nov-19 07:11 PM you talk to suppliers and ask nicely for samples...? 02-Nov-19 07:11 PM that sometimes works 02-Nov-19 07:11 PM I have like a square meter of 0.79mm and 1.2mm teflon pcb 02-Nov-19 07:12 PM why not try making your own ceramic boards? 02-Nov-19 07:12 PM @Deleted User Oh yeha that works if you have uni mail, rogers does samples. 02-Nov-19 07:12 PM ceramic plate is relatively available, then you do electroless deposition 02-Nov-19 07:12 PM Could be interesting 02-Nov-19 07:12 PM or activation and then electrodeposition of Ni-Au, as usual 02-Nov-19 07:12 PM surface quality matters a lot at the higher frequencies for loss 02-Nov-19 07:18 PM how do you search for ceramic plates without finding dinnerware? 02-Nov-19 07:18 PM because I haven't figured out how to yet lol 02-Nov-19 07:18 PM sheet? 02-Nov-19 07:18 PM sheet! 02-Nov-19 07:18 PM yeah, ceramic sheet. 02-Nov-19 07:19 PM Well I doubt too much dinnerware get's made from BeO or alumina. 02-Nov-19 07:19 PM or substrate 02-Nov-19 07:20 PM cool thanks, dunno why didn't think sheet... my vocabulary is often bad 02-Nov-19 09:03 PM Funny mentioning Andrew. I just worked with him all week. I'll be sure to mention the discord to him on Monday 02-Nov-19 09:05 PM small world! 02-Nov-19 09:06 PM It also may or may not have involved certain ion based Microscopes 02-Nov-19 09:06 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191101_185057-85468.jpg 02-Nov-19 09:06 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/flir_20191028T230030-7C06E.jpg 02-Nov-19 09:06 PM would it also have to do with his dayjob? 02-Nov-19 09:06 PM And ion pumps for some type of electron column as well 02-Nov-19 09:06 PM Yes and no 02-Nov-19 09:07 PM ha, he told me what he's doing 02-Nov-19 09:07 PM it all lines up now! 02-Nov-19 09:08 PM I did chemical analysis on the capacitors and elemental mapping on the soldering stuff 02-Nov-19 09:08 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191028_212420-63517.jpg 02-Nov-19 09:08 PM Had an ion guage read -9 instantly on startup 02-Nov-19 09:08 PM For a chamber 02-Nov-19 09:08 PM ... 02-Nov-19 09:08 PM So I pulled it apart and this stuff fell out 02-Nov-19 09:08 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191028_213955-229C0.jpg 02-Nov-19 09:10 PM are they... what are they even? 02-Nov-19 09:10 PM tin whiskers... but... tin beard? 02-Nov-19 09:10 PM or is that some sort of flaking coating... 02-Nov-19 09:10 PM wow so you found one worse than mine! congrats! 02-Nov-19 09:10 PM lmao 02-Nov-19 09:11 PM Yeah thanks 02-Nov-19 09:11 PM I'm so proud of that accomplishment 02-Nov-19 09:11 PM what is it? 02-Nov-19 09:11 PM But yeah I don't know what it is 02-Nov-19 09:11 PM is that the gauge? 02-Nov-19 09:11 PM It's not conductive avoiding to my multimeter 02-Nov-19 09:11 PM But this is on a dual beam 02-Nov-19 09:12 PM some sort of pentaetherene or tungsten-related thing 02-Nov-19 09:13 PM So it's got XeF2 and (CH3)3Pt(CpCH3) gas injectors on it 02-Nov-19 09:13 PM So you know nasty stuff in vacuum 02-Nov-19 09:13 PM It's got 2 other glasses I don't remember off the top of my head 02-Nov-19 09:13 PM But yeah I think it put the guage power supply into an overcurrent protection so the software saw it as low current 02-Nov-19 09:13 PM And so with that information it decided to try to start up all the ion pumps. Which seeing as it was probably at -4 torr went less than well 02-Nov-19 09:23 PM that is one heck of a failure chain 02-Nov-19 09:24 PM Yeah 02-Nov-19 09:24 PM reminds me of the therac failure chain, except nobody dies 02-Nov-19 09:28 PM Lol yeah 03-Nov-19 01:25 AM would you look at that 03-Nov-19 01:25 AM after running for another 24 hr straight my rotary vane pump actually reaches nominal pressure 03-Nov-19 01:25 AM I even swapped the pirani 03-Nov-19 01:25 AM but yep 03-Nov-19 01:25 AM 2x10^-3 mbar 03-Nov-19 01:25 AM hell yeah! 03-Nov-19 01:46 AM and also wow 03-Nov-19 01:46 AM closing the valve to my rotary vane pump leads to an extreeeemly slow rise in pressure 03-Nov-19 01:46 AM like 5 min to get up to e-2 03-Nov-19 01:48 AM From the -3s? 03-Nov-19 01:48 AM yep 03-Nov-19 01:49 AM Not bad for just a roughed system 03-Nov-19 01:49 AM tbh I don't really trust those numbers yet 03-Nov-19 01:49 AM but chamber is at e-6, on the verge to e-7 so it all would add up, it's just a lot better than I had before 03-Nov-19 01:49 AM I mean if had been pummped beyond that for any length of time that would be pretty bad 03-Nov-19 01:50 AM maybe I had a leak / bad connection in the foreline and unknowingly got rid of it when adding the drag 03-Nov-19 01:50 AM But for just outgassing from toughing not bad 03-Nov-19 01:50 AM Wait was the pressure rise foreline or chamber? 03-Nov-19 01:52 AM my chamber is pumped by the turbo, that is pumped by the drag which is pumped by the RV pump, I closed the valve between the drag and RV and the pressure on the drag side increased to e-2 in ~5 mins 03-Nov-19 01:53 AM Ah got it 03-Nov-19 01:53 AM Yeah definitely not bad, how long had the chamber been down for? 03-Nov-19 01:53 AM If the chamber had been down for more than 2 days I would expect a lot slower rise 03-Nov-19 01:55 AM it was at atmosphere for a few weeks until I changed the TMPs oil recently, did some pumping and venting, right now it's been pumped for 24 hrs, but I vented it this morning to swap some gauges around 03-Nov-19 01:55 AM Ok pretty normal then 03-Nov-19 01:56 AM first time for me 03-Nov-19 01:57 AM Lol not bad then 03-Nov-19 01:57 AM I am pretty sure one of my adapters was leaky, with the oil change I also swapped it for a welded one 03-Nov-19 01:57 AM Yeah the oil looked bad 03-Nov-19 01:59 AM the new oil is still a bit discolored due to some traces of the old oil left in the pump, but it's not nearly as bad 03-Nov-19 01:59 AM plus the pump is a lot quieter now for some reason 03-Nov-19 02:00 AM It funny how it works when the oil is the right viscosity 03-Nov-19 02:00 AM the new oil actually is a lot more viscous 03-Nov-19 02:00 AM Exactly 03-Nov-19 02:00 AM Right viscosity 03-Nov-19 02:02 AM anyway, I'm happy 03-Nov-19 02:02 AM Quite pump is usually a happy pump 03-Nov-19 02:02 AM would not exactly call it quiet 03-Nov-19 02:03 AM The drag or the rotary? 03-Nov-19 02:03 AM yes 03-Nov-19 02:03 AM louder than most tmps I know 03-Nov-19 02:03 AM Lol 03-Nov-19 02:03 AM but it's old and I don't know its history 03-Nov-19 02:03 AM got it from someone who definitely did not know what he was doing 03-Nov-19 02:04 AM I'm spoiled with mag lev pumps a lot 03-Nov-19 02:04 AM it ran for ~200 hrs since I got it and it didn't change, so yeah 03-Nov-19 02:04 AM What's it sounds like? 03-Nov-19 02:04 AM The rotary 03-Nov-19 02:04 AM Is the noise constant or slightly more intermittent? 03-Nov-19 02:05 AM the rotary sounds just fine, very constant 03-Nov-19 02:07 AM Try lubricating the motor bearings 03-Nov-19 02:07 AM Surprisingly common source of noise 03-Nov-19 02:07 AM ah, sorry, I misread 03-Nov-19 02:07 AM I thought you asked if the drag or turbo were "loud", not if the drag or rotary 03-Nov-19 02:07 AM the rotary works perfectly, but the drag and turbo are somewhat whiney 03-Nov-19 02:09 AM Ah ok 03-Nov-19 02:09 AM Whine or grinding noise? 03-Nov-19 02:09 AM whine 03-Nov-19 02:09 AM grinding would be a bit concerning 03-Nov-19 02:09 AM Does it ramp up or steep up on startup? 03-Nov-19 02:09 AM The frequency 03-Nov-19 02:10 AM ramp 03-Nov-19 02:10 AM Not definitive but that's usually bearings 03-Nov-19 02:10 AM isn't that just a function of the controller? 03-Nov-19 02:11 AM ? 03-Nov-19 02:11 AM In what way? 03-Nov-19 02:11 AM the ramp on startup 03-Nov-19 02:11 AM Oh 03-Nov-19 02:11 AM Controllers often ramp up frequency in steps 03-Nov-19 02:12 AM yeah, you can hear those steps 03-Nov-19 02:12 AM So if you can hear distinct steps with no frequency ramp can sometimes be coil whine instead of bearings 03-Nov-19 02:13 AM yep 03-Nov-19 02:13 AM spindown in vacuum takes 5 to 10 minutes, I guess that's good enough 03-Nov-19 02:13 AM of course it's not toe 20+ mins of a maglev 03-Nov-19 02:13 AM but hey 03-Nov-19 02:13 AM datecode of 82 iirc 03-Nov-19 02:14 AM Lol it's doing great then 03-Nov-19 02:14 AM Some mag leaves sound awful on landing 03-Nov-19 02:15 AM never heard them 03-Nov-19 02:15 AM only in regular use 03-Nov-19 02:16 AM Yeah bellow some rpm some just drop to the safety bearings 03-Nov-19 02:16 AM In spectacular fashion 03-Nov-19 02:18 AM just looked up some videos 03-Nov-19 02:18 AM I'd get a panic attack every time my pump would make that sound 03-Nov-19 02:18 AM Yeah I didn't hear it for a while because the pumps I was around didn't do that 03-Nov-19 02:18 AM So the first time I did I was like what the hell? 03-Nov-19 02:18 AM Except I didn't say hell 03-Nov-19 02:19 AM but that would not be child friendly 03-Nov-19 02:20 AM I can neither confirm nor deny 03-Nov-19 02:21 AM https://www.youtube.com/watch?v=Jnb6uYAzuno 03-Nov-19 02:21 AM cough whoops https://www.youtube.com/watch?v=4wKPTWXD2Z0 03-Nov-19 02:22 AM Original actually sounds better 03-Nov-19 02:23 AM yep 03-Nov-19 02:24 AM In the next video in recommend they start tapping brand new turbine blades together 03-Nov-19 02:25 AM whoops 03-Nov-19 02:25 AM Like internally 03-Nov-19 02:25 AM On purpose 03-Nov-19 02:25 AM Before installing them 03-Nov-19 02:25 AM It's strange seeing something so sensitive yet they can be handled with no gloves 03-Nov-19 02:25 AM Working with vacuum stuff distors my perspective on cleanliness 03-Nov-19 02:27 AM it's not high vacuum stuff 03-Nov-19 02:27 AM yeah, definitely 03-Nov-19 02:32 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190312_101606-C80FD.jpg 03-Nov-19 02:32 AM F 03-Nov-19 02:32 AM Obligatory turbo crash photo 03-Nov-19 02:32 AM Well this was actually a burst 03-Nov-19 02:32 AM So a lot worse 03-Nov-19 02:32 AM a tad of hot glue, a bit bending those fins 03-Nov-19 02:32 AM it's work for another 5 years 03-Nov-19 02:33 AM Yeah 03-Nov-19 02:33 AM ouch 03-Nov-19 02:33 AM Especially after you mealt it back down and re machine everything from scratch 03-Nov-19 06:54 AM @AdamMcCombs is it possible to ask for a piece of rotor? 03-Nov-19 06:54 AM For display purposes. 03-Nov-19 06:54 AM Especially after you mealt it back down and re machine everything from scratch 03-Nov-19 06:54 AM I would actually machinea disk and put into a brushless motor to see what happens in vqcuum 03-Nov-19 06:57 AM it would 03-Nov-19 06:57 AM dumroll 03-Nov-19 06:57 AM spin! 03-Nov-19 06:57 AM actually that's how the earliest drag pumps worked 03-Nov-19 12:05 PM @Nixie the customer kept it at their site so unfortunately I don't have any of it... I wanted it though 03-Nov-19 12:11 PM Oh well. 03-Nov-19 12:11 PM Yeah same 03-Nov-19 02:24 PM Yeah it's possible to turn a fib column into a sem column 03-Nov-19 02:24 PM But it's optical performance is pretty bad 03-Nov-19 02:26 PM he said 10-20nm res 03-Nov-19 02:26 PM limited on spherical aberration 03-Nov-19 02:27 PM Yeah 100% 03-Nov-19 02:27 PM would be great if that's the only column I could fit 03-Nov-19 02:27 PM For semiconductor stuff it really doesn't have the resolution 03-Nov-19 02:27 PM well I am not really doing too much of that 03-Nov-19 02:28 PM But if you're doing larger stuff it should work 04-Nov-19 01:30 AM "The MDP 5011 CP is specially designed for aggressive environments. Ball bearings and motor are isolated from process gases by a dynamic inert gas purge system." 04-Nov-19 01:30 AM (re: chemically "tolerant" drag turbo) 04-Nov-19 11:51 AM Sounds like a regular purge system, my pfeiffer turbo has one as well 04-Nov-19 11:51 AM But then again, they probably come from the same design team 04-Nov-19 04:12 PM Is yours a chemically resistant model? 04-Nov-19 04:31 PM aluminium and stainless, and the purge input is at the bottom of the blade stack... so probably, but I'm not open to testing it 04-Nov-19 08:36 PM Just wondered if it was common or you knew it was specially labeled. Does it have a C in the model name? 04-Nov-19 08:37 PM nope, TPH-062 04-Nov-19 08:37 PM Got the ebay turbo today, is it normal if the turbine below the top one doesn't spin? 04-Nov-19 08:37 PM The topmost one spins 04-Nov-19 08:37 PM that's a stator 04-Nov-19 08:37 PM it's just like a jet engine 04-Nov-19 08:37 PM rotor | stator | rotor 04-Nov-19 08:38 PM Hmm, ok, cool, will have to keep it in mind to read about 04-Nov-19 08:38 PM Didn't know about jet engines either 04-Nov-19 08:38 PM the one below that is the rotor, the one below that is a stator ring 04-Nov-19 08:38 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/250px-Turbo_pump_schematic-2011-05-02-6D52A.png 04-Nov-19 08:41 PM Without the stators the molecules would just bounce in a circle 04-Nov-19 08:41 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/blade-removal-5501B.png 04-Nov-19 08:42 PM The stators redirect them downwards 04-Nov-19 08:42 PM And into the next stage. They also help maintain the pressure gradiant more than just the rotors alone 04-Nov-19 08:44 PM It's also probably what makes it quite expensive 04-Nov-19 08:44 PM You can machine the rotor out of a single billet on a 5-axis machine, but stators, not so much 04-Nov-19 08:44 PM Even if they don't need balancing at all 04-Nov-19 08:45 PM The precision and care needed for stators is way less 04-Nov-19 08:46 PM Still can't stamp them 04-Nov-19 08:46 PM And you need multiple setups to machine a single stator piece 04-Nov-19 08:46 PM Yeah but still 04-Nov-19 08:46 PM With a rotor, you can just hit "go" and get a rotor out 20 hours later, on a relatively modern machine 04-Nov-19 08:47 PM It's not a high precision piece of metal made on an expensive machine being spun or levitated faster than most hard drives 04-Nov-19 08:47 PM Hard drives are mass-manufactured though 04-Nov-19 08:47 PM 2d fixturing is so cheap though 04-Nov-19 08:47 PM cost has to be down in the double digit dollars 04-Nov-19 08:47 PM 2d fixturing is cheap but it's a ton of effort 04-Nov-19 08:47 PM I guess it's 50/50 in terms of the cost, assuming your balancing rig is automated 04-Nov-19 08:50 PM The stators are going to take so much less time to machine 04-Nov-19 08:50 PM You have way better clearing access 04-Nov-19 08:50 PM And the rotor is going to be multi op multi machine 04-Nov-19 08:51 PM with a modern machine, it's probably only two setups 04-Nov-19 08:51 PM machine the bottom, reclamp the bottom, machine the blades 04-Nov-19 08:51 PM something like a DMG Monoblock could do that 04-Nov-19 08:51 PM though I'm guessing they're not made on a monoblock but closer to something like a KERN, because precision and surface quality 04-Nov-19 08:53 PM And depending on the rotor you need the add the magnets for levitation or purpolsion 04-Nov-19 08:53 PM you do need to add magnets regardless 04-Nov-19 08:53 PM I wonder how they balance the magnets... do they buy special super perfectly sintered magnets? 04-Nov-19 08:53 PM And it's a very high strength aloy, the metrology in turbos is a bit proprietary 04-Nov-19 08:53 PM they must be, given the dynamic load... 04-Nov-19 08:53 PM regular magnets are rough and the internal structure is not uniform 04-Nov-19 09:19 PM @AdamMcCombs nice Hackaday piece 04-Nov-19 09:20 PM Uh 04-Nov-19 09:20 PM https://hackaday.com/2019/11/04/investigating-retroreflectors-with-one-heck-of-a-microscope/ 04-Nov-19 09:20 PM Oh shit 04-Nov-19 09:20 PM Front page, top post 04-Nov-19 09:20 PM That's the first I heard of that 04-Nov-19 09:20 PM Cool! 04-Nov-19 09:20 PM That's actually my first front page besides my talks 04-Nov-19 09:20 PM I'm also giving a workshop with a sem at supercon in 2 weeks as well 04-Nov-19 09:20 PM So I'm sure there's going to be more on the site soon 04-Nov-19 09:29 PM Lol 04-Nov-19 09:29 PM Nice 05-Nov-19 12:13 AM https://www.youtube.com/watch?v=9tKs55UYlAY 05-Nov-19 12:13 AM A cool video showing how giant turbo+drag combos are made 05-Nov-19 12:13 AM 36 hours of non-stop work 05-Nov-19 02:17 AM as ugly a fix as that was...my turbo seems to have some life in it 05-Nov-19 02:17 AM video tomorrow or sometime when i am not about to head off to bed heh 05-Nov-19 02:35 AM @Deleted User that drag part is called Holweck stage 05-Nov-19 05:49 AM Huh...those stators look stamped to me, what am I missing that makes @Deleted User say they can't be made rhat way? 05-Nov-19 05:50 AM where did spirit say that? 05-Nov-19 05:50 AM I know stators and even rotors can be stamped 05-Nov-19 05:52 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_20191105-145211-B5404.png 05-Nov-19 05:52 AM remind me to take some pics once I'm back home 05-Nov-19 05:52 AM because the stators of my small balzers are stamped (don't remember the name) 05-Nov-19 05:52 AM and the rotors of my turbovac 150 are stamped 05-Nov-19 05:52 AM https://cdn.shopify.com/s/files/1/1919/1299/products/leybold-turbomolecular-turbovac-150-vacuum-pump-85471-1182-19t068-leybold-3_1024x1024.jpg?v=1532764933 05-Nov-19 05:52 AM looks pretty stamped to me 05-Nov-19 05:52 AM ah and the balzers is a TPH-062 05-Nov-19 05:52 AM but I can't find any pics of the internals 05-Nov-19 05:52 AM hah, found pics! 05-Nov-19 05:52 AM https://twitter.com/GigaBecquerel/status/1048961389702856705 05-Nov-19 05:52 AM the top ones are CNCd, but the later stages are just stamped 05-Nov-19 10:15 AM @Nixie @GigaSquirrel thick ones can't be stamped 05-Nov-19 10:15 AM thin ones can, yes 05-Nov-19 11:50 AM Wow, did not expect stamped rotors to be feasible. 05-Nov-19 11:50 AM Define "thick ones" 05-Nov-19 11:52 AM the rim has to be thin enough to stamp 05-Nov-19 01:47 PM tbh I'm still not sure what you're getting at @Deleted User 05-Nov-19 01:47 PM of course you can't samp an infinitely large turbo 05-Nov-19 01:48 PM there's a limit to how thick the source material can be for this aspect ratio of stamping 05-Nov-19 01:48 PM the thin blades can be stamped, but large ones would crack or shear 05-Nov-19 01:51 PM ah, yes 06-Nov-19 12:49 PM How good is glass for vacuum chambers? Permeability and I guess hydrogen solubility, if that's the right term 06-Nov-19 12:49 PM Like obv vac tubes... 06-Nov-19 12:49 PM Was thinking if i could 'weld' a glass chamber 06-Nov-19 12:49 PM Since it's relatively easy to melt borosilicate 06-Nov-19 12:51 PM Glass chambers have definitely been used for UHV and possibly even in the XHV range (I'll have to double check that though). There are many different grades of glass though with different outgassing rates and permeability. 06-Nov-19 12:52 PM I was actually thinking a glass lined metal chamber, metal reducing stress, have them pumped together to rough vac, then valve off the metal and only go high on the glass 06-Nov-19 12:52 PM So I could make an inductively coupled plasma chamber, but huge 06-Nov-19 12:52 PM And cubic, instead of round 06-Nov-19 12:54 PM How high vacuum? Double pumped chamber is probably way overkill 06-Nov-19 12:54 PM How big of a glass chamber as well? Like bell jar? 06-Nov-19 12:58 PM You don't want to mix glass and plasma for delicate processes 06-Nov-19 12:58 PM You'll get a ton of glass ions flapping around in the chamber 07-Nov-19 12:36 AM Chamber I'm thinking would be around 26" x 26" x maybe 2" 07-Nov-19 12:36 AM Glass/quartz 07-Nov-19 12:36 AM The plasma cleaner I've been using is glass/quartz (I don't know how to tell) 07-Nov-19 12:37 AM why cubic? 07-Nov-19 12:38 AM I am thinking i may need to put a nickel 'shim' in it 07-Nov-19 12:38 AM and chambers are a thing, but there's always an implosion risk involved 07-Nov-19 12:39 AM Which is formed by electroforming on photoresist, then stamped into uv cured resin to make a bigger imprinted area, then electroformed again 07-Nov-19 12:39 AM Then that big "shim" would be wrapped around a drum 07-Nov-19 12:39 AM And the drum used in a roll to roll process for production of imprinted plastic film 07-Nov-19 12:39 AM Using UV cured resin again 07-Nov-19 12:39 AM Implosion risk was why I was thinking a metal box, with a smaller glass box inside (but I guess I really mean quartz .. which presumably is much harder to fuse than borosilicate) 07-Nov-19 12:39 AM So that probably defeats my idea 07-Nov-19 01:02 AM but would the metal not defeat the advantages of glass? 07-Nov-19 01:19 AM Glass chambers are a thing, absolutely /snickers/ However, wouldn't there be problems with glass/metal expansion rate (and a kovar chamber would be insanely expensive. ) 07-Nov-19 02:04 AM co-wario 07-Nov-19 05:55 AM Its'a me, Luigi! 07-Nov-19 09:47 AM I was thinking the metal and glass would be separated by a few mm, not fixed together 07-Nov-19 11:03 PM yeah let them space for breathing 08-Nov-19 11:38 AM I just saw Richard Hull in a YouTube video 08-Nov-19 11:38 AM Is a nice old man 08-Nov-19 11:38 AM I'm in Chile. The country just imploded 08-Nov-19 11:44 AM Good timing? 08-Nov-19 11:44 AM Or living there in general? 08-Nov-19 11:46 AM I live here 08-Nov-19 11:46 AM Hope things get better 08-Nov-19 11:46 AM this is going worse each day 08-Nov-19 11:47 AM :( 08-Nov-19 11:47 AM I think I will live with Lukas 08-Nov-19 11:47 AM In Germany 08-Nov-19 11:47 AM He can clear his workshop and put another bed 08-Nov-19 11:47 AM Heh 08-Nov-19 11:48 AM This is the subway 08-Nov-19 11:50 AM Oh boy that is so much worse 08-Nov-19 11:51 AM please move this to #off-topic-thats-sometimes-on-topic 08-Nov-19 11:51 AM Not encountered much in the local media since the initial protests 08-Nov-19 07:41 PM during this long us weekend (veterans day on monday) I may be tempted to do a brief email to that job about assemblage of spaceflight mass specs.. they've been calling the school a bunch, and they do have an alumni applicant, not sure if it was a recent grad or what.. but I figure I should atleast introduce myself to some degree.. but it sounds liek their current assembler is really gearing for retirement and they are trying to onboard someone asap 08-Nov-19 07:41 PM which - I can't do just yet 09-Nov-19 12:48 AM I had no idea it was a "long weekend" 09-Nov-19 12:48 AM huh, I wonder what that means since someone scheduled a meeting with me that day... and that's also one of my scheduled part-time days 09-Nov-19 01:03 AM Good luck @chucrut !! 09-Nov-19 02:41 AM well, it's almost there (lab poster)... I think I just need to use a log scale 09-Nov-19 02:41 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/vac_compare-4F9E2.png 09-Nov-19 02:41 AM and then send to a graphic designer friend for making look cool 09-Nov-19 10:38 AM hey @nmz787, someone wants to know what material your fib uses to do the milling 09-Nov-19 10:46 AM @Deleted User gallium 09-Nov-19 10:46 AM in some sort of gas? 09-Nov-19 10:47 AM It's an LMIS, liquid metal ion source 09-Nov-19 10:47 AM Gallium is liquid at low temp 09-Nov-19 10:47 AM So it is wetted on a filament, and the filanent is heated slightly 09-Nov-19 10:47 AM And a 30kV bias applied between the filanent and stage 09-Nov-19 10:48 AM So you're basically... boiling off gallium ions instead of electrons 09-Nov-19 10:48 AM Almost, the electric field causes a mechanical movement of the material to form a cone, a taylor cone 09-Nov-19 10:48 AM And ions exract off the tip of that cone 09-Nov-19 10:49 AM That is ingenious and very cool, I never knew that's how they worked! 09-Nov-19 10:49 AM Yeah pretty neat stuff 09-Nov-19 10:50 AM Electrostatically steered? 09-Nov-19 10:50 AM Yep 09-Nov-19 10:51 AM That is neat 09-Nov-19 10:51 AM What's the difference between deposition and milling? Extraction voltage/ion speed? 09-Nov-19 11:12 AM Hmm, I'm not sure, I guess so. Mostly it's milling. Deposition usually is only intentionally done when a gas is introduced in the beam path near the sample 09-Nov-19 11:12 AM Can yours do deposition? 09-Nov-19 11:12 AM I only have a carbon deposition injector right now 09-Nov-19 11:12 AM I would like platinum or even tungsten 09-Nov-19 11:13 AM With a bit of software hacking you could build the world's least versatile 3D printer 09-Nov-19 11:13 AM FIBSlicer™ 09-Nov-19 11:15 AM Lol, basically 09-Nov-19 11:15 AM That would make a cool youtube video and/or talk 09-Nov-19 11:15 AM "I turned a vintage FIB into a nano 3D printer" is a totally true, yet somehow clickbait title 09-Nov-19 11:15 AM I'm already trying to get control over the beam for more-automated imaging and milling 09-Nov-19 11:15 AM Any success on reversing the libraries? 09-Nov-19 11:16 AM Well, it's only 14 years old 09-Nov-19 11:16 AM Not terribly vintage 09-Nov-19 11:16 AM "old" instead of vintage :P 09-Nov-19 11:17 AM Nah I haven't spent any more time besides buying an FPGA with SDRAM for $20, and doing a bit of research onto what PCB would be compatible with 33MHz 09-Nov-19 11:17 AM It wouldn't help much if you just get a bunch of byte sequences 09-Nov-19 11:17 AM Too much other life happening 09-Nov-19 11:17 AM Well,I was thinking I could replay PCI bus sequences 09-Nov-19 11:17 AM My new hardware "driver" 09-Nov-19 11:18 AM But then you wouldn't know which messages control what part of the beam 09-Nov-19 11:18 AM Basically a family member came from out of town on Tuesday 09-Nov-19 11:18 AM Plus work, plus the kid 09-Nov-19 11:18 AM Plus using the FIB for a project 09-Nov-19 11:18 AM Seems like next step is to instrument the EXE to get it to log DLL calls 09-Nov-19 11:20 AM yeah you could just inject something that would hook all the function calls 09-Nov-19 11:28 AM moin! 09-Nov-19 11:28 AM Oh, apparently my wife was just looking at the driver in IDA before my son called her away 09-Nov-19 11:28 AM moin! 09-Nov-19 11:28 AM Now that's a cool wife 09-Nov-19 11:29 AM Hehe I'll let her know 09-Nov-19 11:29 AM Have you tried contacting the manufacturer? 09-Nov-19 11:29 AM If it even exists 09-Nov-19 11:29 AM Well the FIB manufacturer, yes 09-Nov-19 11:29 AM Perhaps they'd be willing to give you the source code for the driver and the old software 09-Nov-19 11:30 AM They won't give me the service manual for the fib 09-Nov-19 11:30 AM Oh, it's one of those manufacturers. 09-Nov-19 11:30 AM OKI made the PCI card, but I didn't think to try them 09-Nov-19 11:30 AM Try talking to them 09-Nov-19 11:30 AM Hmm, worth a shot 09-Nov-19 11:30 AM I'd give them a call 09-Nov-19 11:30 AM Way more intimidating and causes immediate action 09-Nov-19 11:30 AM Wait, if OKI made the card - is it a standard card? 09-Nov-19 11:30 AM Like an off the shelf product used elsewhere? 09-Nov-19 11:33 AM Doesn't seem so 09-Nov-19 11:34 AM Well, worth trying to talk to them 10-Nov-19 01:41 AM Good morning! 10-Nov-19 07:50 AM moin 10-Nov-19 12:23 PM Joined the server. 10-Nov-19 12:23 PM Yay! 10-Nov-19 07:43 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191110_192708-3E492.jpg 10-Nov-19 07:43 PM I'm about to pack this scope up to bring it to a conference 10-Nov-19 07:43 PM For 2 days of use at the conference 10-Nov-19 08:57 PM woot wish I could be there 10-Nov-19 09:31 PM Nice! 11-Nov-19 07:05 AM awesome 11-Nov-19 11:24 AM Adam. You going to supercon? 11-Nov-19 11:26 AM Me and the scope yup 11-Nov-19 01:58 PM Just bought a few hundred dollars in vac pump oil, for my SEM and general-use rough pump, for my diff pump, and for my ebay turbo bearing sump 11-Nov-19 01:58 PM Now I have to pull the SEM diff pump off and clean the silicone oil I added a few years ago (but never ran with) 11-Nov-19 01:58 PM Since Adam said, and the internet confirms, silicone oil will turn into a hard glassy dielectric with e-beam irradiation 11-Nov-19 01:58 PM Thus messing up the beam shape/quality 11-Nov-19 03:32 PM jeez adam I get conflicted about spending the extra $$ on another checked bag for multi-day-long conventions 11-Nov-19 03:32 PM how in the world do you afford doing that sort of thing? >.> 11-Nov-19 04:20 PM I think he basically only had to rent a truck for a local transport. He's also doing a workshop that was sold-out, so hopefully that will make up some of the costs 11-Nov-19 04:34 PM oh, fair enough 11-Nov-19 04:35 PM Lol were not charging much for the workshop 11-Nov-19 04:35 PM Hackaday is paying for the hard expenses 11-Nov-19 04:58 PM oh, score 11-Nov-19 04:58 PM It's really not much though 11-Nov-19 04:58 PM Plus I shipped this system earlier this year so I had the shipping hardware for it on hand 11-Nov-19 04:58 PM And it's already in la. It would be a lot more if it were from Washington 12-Nov-19 04:41 AM Hi 12-Nov-19 04:41 AM I have a question. I cannot reach below 0.7 Pascal in my vacuum chamber 12-Nov-19 04:41 AM I'm using a diffusion pump 12-Nov-19 04:41 AM At this vacuum level I should focus in finding leaks or in reducing outgassing? 12-Nov-19 04:44 AM thats a serious leak 12-Nov-19 04:44 AM Hi Lukas. You dont think outgassing is relevant at this level? 12-Nov-19 04:48 AM well, depends 12-Nov-19 04:48 AM of you have a piece of wood in your chamber it's outgassing a lot 12-Nov-19 04:48 AM but if everything is metal that's a leak 12-Nov-19 04:49 AM I put compressed air from the outside to see any difference in the vacuum sensor 12-Nov-19 04:49 AM I have a big rubber seal 12-Nov-19 04:49 AM And I used silicone to reinforce some seals 12-Nov-19 04:50 AM hardware store silicone? 12-Nov-19 04:50 AM Yes 12-Nov-19 04:50 AM there's your issue 12-Nov-19 04:51 AM Not hot glue 12-Nov-19 04:51 AM Cold silicone 12-Nov-19 04:51 AM that's nowhere near vacuum rated 12-Nov-19 04:51 AM it's gonna outgass a lot 12-Nov-19 04:51 AM all the acetic acid etc 12-Nov-19 04:51 AM Ieutral 12-Nov-19 04:51 AM I bought neutral silicone 12-Nov-19 04:51 AM Without acetic acid 12-Nov-19 04:52 AM hmm 12-Nov-19 04:52 AM but still 12-Nov-19 04:52 AM if you really can't weld your leaks shut use epoxy 12-Nov-19 04:54 AM I made a custom silicone-rubber seal because is a rectangular vacuum chamber 12-Nov-19 04:55 AM you know pictures would really help here 12-Nov-19 04:55 AM Okay 12-Nov-19 05:34 AM This is a very hard rubber. 11mm thickness 12-Nov-19 05:34 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20191112_100835-F87F0.jpg 12-Nov-19 05:34 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20191112_100831-F1689.jpg 12-Nov-19 05:34 AM I put silicone below and the hard rubber up 12-Nov-19 05:34 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20191112_103400-41C34.jpg 12-Nov-19 05:34 AM This is the silicone. I hope you dont have a heart attack 12-Nov-19 05:34 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20191112_100939-4654E.jpg 12-Nov-19 05:34 AM So this is the main sealing for the chamber. I dont know if 0.7 Pascal is because I have a leak or I should focus in outgassing 12-Nov-19 05:54 AM Also this is my workshop. Is located in the forest near the city 12-Nov-19 05:54 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20191112_100356-BE25B.jpg 12-Nov-19 05:54 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/15735670870598977457790614981257-899CF.jpg 12-Nov-19 06:00 AM Also, what kind of rubber? Maybe its not rated for vacuum. 12-Nov-19 06:08 AM I think is a sealing rubber. The main application is not for vacuum sealing, but is what I found here 12-Nov-19 07:55 AM I made another vacuum test. I put many chunks of silicone inside the chamber. And the final vacuum was the same 0.7 Pascal 12-Nov-19 07:55 AM So I think silicone outgassing is not relevant at this level 12-Nov-19 07:55 AM Maybe I have a leak 12-Nov-19 11:07 AM Why would you make a seal out of two materials? 12-Nov-19 11:07 AM Just a thin sheet of vacuum rated rubber should be enough 12-Nov-19 11:07 AM But you can completely forget reaching anything below -5 or so with this kind of chamber 12-Nov-19 11:07 AM Definitely not the -11 you want 12-Nov-19 01:17 PM You are right. Maybe i need to use only 1 material 12-Nov-19 01:19 PM for e-11 the only viable seal is metal to metal 12-Nov-19 01:27 PM yea if you want e-11 all metal to metal and tons of different pump types, definitely not just diffusion 12-Nov-19 01:27 PM at-least tons of cryo 12-Nov-19 01:30 PM are you sure about non-diffusion? 12-Nov-19 01:30 PM with sth like DC705 it just may work 12-Nov-19 01:30 PM that and a good baffle ofc 12-Nov-19 01:40 PM I don't think you can realistically hit that with a diffusion pump. Even with cryo trapping and all metal seals 12-Nov-19 01:41 PM how would you achieve it? 12-Nov-19 01:41 PM 10^-11? 12-Nov-19 01:41 PM like torr? 12-Nov-19 01:42 PM torr, mbar, doesn't really matter 12-Nov-19 01:45 PM lol fair. Thats gotta be ion pumped or NEG and a whole lot of baking. Maybe cryo or turbo, but with special considerations 12-Nov-19 01:45 PM you don't need 10^-11 for a whole lot though lol 12-Nov-19 01:48 PM Turbo would end up being a "roughing pump" for that kinda vacuum 12-Nov-19 01:48 PM yeah lol 12-Nov-19 01:48 PM though in some KJL application note there is a mention of some Japanese team putting several turbos in series to get down that low 12-Nov-19 01:49 PM But honestly Cryo is a good start to something like that, Cryo has the added benifit of being quite robust, no worries of oil fires or crashing turbos 12-Nov-19 01:49 PM Worst you'll get is overloaded on the cold fingers and end up outgassing a ton when you turn it off, which can over-pressure the chamber but I have yet to see a cryo head WITHOUT a blowoff valve on it 12-Nov-19 01:53 PM Issue with going up to 10^-11 and deeper with cryo is that you have to ideally reduce gas load as much as possible prior to getting there so you don't need to regenerate. Either way, you will be baking and pumping for a long time lol 12-Nov-19 01:53 PM I don't think there's a situation in which you could overpressure a chamber 12-Nov-19 01:53 PM Given that you pump the chamber down with a forepump first 12-Nov-19 01:57 PM You can always gate off the cryo pumps too to regenerate them on the fly, especially if you have more than one on a chamber 12-Nov-19 01:58 PM I wonder if a cryopump would survive being continuously overloaded, to liquefy gases 12-Nov-19 01:58 PM yeah, though the real question is why do you need 10^-11 lol. That's a pretty large undertaking lol 12-Nov-19 01:58 PM He never explained why 12-Nov-19 02:01 PM unfortunately, there is no way he is getting even remotely close with that setup, its not physically possible. Maybe 10^-5 like you mentioned after everything is perfect 12-Nov-19 02:01 PM which most processes require only up to 10^-6 at most, that covers like 90% of what you would do in vacuum lol 12-Nov-19 02:04 PM That's what I'm hoping to reach with a fully off the shelf setup 12-Nov-19 02:04 PM But it's all KF, the only CF fitting in the whole thing is the pirani gauge... ironically 12-Nov-19 02:05 PM The prices of conflats made me not want to look at the prices of conflats 12-Nov-19 02:05 PM Especially in the sizes I want 12-Nov-19 02:08 PM kF can do that fine 12-Nov-19 02:08 PM -6 is my minimum goal, -7.5 is the target 12-Nov-19 02:08 PM but I don't really need anything higher than that 12-Nov-19 02:09 PM even my 6" conflat thruster chamber is mostly viton, though still CF hardware, and can get down mid 10^-6 after a couple hours. What process are you looking to do at those levels? 12-Nov-19 02:10 PM Checking off "high vacuum" off my bucket list 12-Nov-19 02:10 PM But also experimenting with x-ray tube manufacture 12-Nov-19 02:12 PM depends on the x-ray tube and how you define a "tube" lol 12-Nov-19 02:12 PM The (probably unobtainable for me) goal is an actual microfocus x-ray tube 12-Nov-19 02:12 PM Glass, probably, since the rest is very expensive to make 12-Nov-19 02:12 PM makes sense in that case 12-Nov-19 02:34 PM All this reminds me of that plexiglass x-ray tube with a fork and spoon as the electrodes. 12-Nov-19 02:34 PM "we can deal with bad vacuum by just pumping in more energy" 12-Nov-19 02:35 PM Oh yeah lol from JC Martin 12-Nov-19 02:35 PM But that was a fast pulsed system, much different mechanisms than dc. You don't need as good vacuum in that case 12-Nov-19 02:40 PM Maybe I should get into XRF tube manufacture 12-Nov-19 02:40 PM Focus doesn't matter for them, all you have to do is shove as many watts into the anode at 60kV as possible 12-Nov-19 02:46 PM What's XRF? 12-Nov-19 02:46 PM x-ray fluorescence 12-Nov-19 02:46 PM Oh lol 12-Nov-19 02:46 PM you slam x-rays into a thing, physics happen, you measure the resulting spectra 12-Nov-19 04:47 PM i love it when physics happens 12-Nov-19 05:13 PM x-rays knock out lower orbital electrons, higher orbital electrons jump down to fill the hole, the net energy difference is another x-ray peak, proportional to the atom 12-Nov-19 05:13 PM or concisely put, physics happens 12-Nov-19 05:21 PM the world desperately needs* a DIY handheld XRF gun 12-Nov-19 05:21 PM * needs in the 'i want it but it's probably a terrible idea' sense 12-Nov-19 05:24 PM handheld is very complicated 12-Nov-19 05:24 PM or, well, either very complicated or very expensive 12-Nov-19 05:24 PM the only way to get handheld xrf is by using a silicon drift detector 12-Nov-19 05:24 PM a tiny SDD in a TO-can package is all you need 12-Nov-19 05:24 PM "all you need" is also ~$3k for each detector 12-Nov-19 05:24 PM https://www.ebay.com/itm/Amptek-FAST-SDD-Silicon-Drift-Detector-Spectrometer-XRF/223718366407 12-Nov-19 05:24 PM this is slightly cheaper, but far worse performance 12-Nov-19 05:24 PM https://www.ebay.com/itm/NEW-Amptek-Si-PIN-Detector-w-PA230-PreAmp-25mm-2-1mil-Be-Win/223738201914 12-Nov-19 05:28 PM yeah i was thinking along the lines of a PIN diode detector 12-Nov-19 05:28 PM not just any pin diode 12-Nov-19 05:28 PM it has to be a special x-ray kind 12-Nov-19 05:28 PM (trust me, I tried the other ones, they suuuuuuuck) 12-Nov-19 05:29 PM And thermoelectrically cooled 12-Nov-19 05:29 PM yeah, those TO can packages have teeny weeny peltier stacks 12-Nov-19 05:29 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/TO-8_ASM_Selector-32x-92423.png 12-Nov-19 05:29 PM this is what Amptek use 12-Nov-19 05:30 PM what makes it special? die size/thickness? depletion region size? waves hands around purity?? 12-Nov-19 05:30 PM haha omg it's wonderful 12-Nov-19 05:30 PM probably all three 12-Nov-19 05:30 PM waves hands around magic 12-Nov-19 05:31 PM you can get cascaded peltier modules off the shelf at least 12-Nov-19 05:31 PM was considering a four-element one just to, like, have around 12-Nov-19 05:31 PM and my current best iteration of my indefinitely-deferred cloud chamber uses a dual-element TEC2 somethingorother 12-Nov-19 05:32 PM What was the FWHM resolution for your DIY PIN diode spectrometer @Deleted User ? 12-Nov-19 05:33 PM it was "weh" 12-Nov-19 05:33 PM I saw what kind of sort of looked like an x-ray peak 12-Nov-19 05:33 PM lol 12-Nov-19 05:33 PM which diode did you use? 12-Nov-19 05:33 PM tried a few 12-Nov-19 05:33 PM (betting BPW43) 12-Nov-19 05:33 PM or was it 34 12-Nov-19 05:33 PM don't think I tried that one 12-Nov-19 05:33 PM 34 12-Nov-19 05:34 PM i have a fistful of bpw34s i bought to attempt similar with, with the caveat that i am not expecting any kind of great performance 12-Nov-19 05:34 PM also to try decapping 'em 12-Nov-19 05:34 PM you can get ok-ish performance with 34s 12-Nov-19 05:34 PM I know of an university project that made several low cost spectrographs with those 12-Nov-19 05:34 PM but nowhere NEAR XRF 12-Nov-19 05:34 PM with a carefully designed preamp to get more performance from them 12-Nov-19 05:35 PM I'm thinking about getting some SiC UV photodiodes to do this 12-Nov-19 05:35 PM xrf has super demanding resolution requirements, i know that much 12-Nov-19 05:35 PM I believe SiC UV XRF photodiodes exist 12-Nov-19 05:35 PM I've seen a few papers on them 12-Nov-19 05:35 PM https://sci-hub.se/10.1016/j.nima.2018.01.054 12-Nov-19 05:35 PM such at this 12-Nov-19 05:36 PM https://www.newark.com/sglux/sg01s-18/photodiode-sic-uv-a-0-06mm2-to18/dp/53W9990 12-Nov-19 05:36 PM yep that's the company 12-Nov-19 05:36 PM Not too expensive at all 12-Nov-19 05:36 PM from the paper 12-Nov-19 05:36 PM they sell directly from their site too iirc 12-Nov-19 05:36 PM including delidded photodiodes 12-Nov-19 05:36 PM the only downside is that the sizes are TINY 12-Nov-19 05:36 PM so conversion efficiency is nigh zero 12-Nov-19 05:38 PM Just count for a long time, but hey, you'd get your resolution 12-Nov-19 05:38 PM or using a very powerful XRF tube 12-Nov-19 05:38 PM the kind that delivers many sieverts/rad per second 12-Nov-19 05:39 PM wonder if pulsed XRF is feasible 12-Nov-19 05:39 PM nope 12-Nov-19 05:39 PM you don't want a high voltage, you want a stupidly high flux 12-Nov-19 05:39 PM most XRF tubes are only rated at 60kV 12-Nov-19 05:39 PM This is based on charge sensitive preamps that does pulse height discrimination, so you'd run into piling up with pulsed 12-Nov-19 05:40 PM the sensitivity is so low that you won't 12-Nov-19 05:40 PM you'd definitely crash an SDD if you shined a full-on XRF tube at it 12-Nov-19 05:40 PM instead of a handheld one 12-Nov-19 05:41 PM With larger area detectors biased at a high voltage I think you would... They sell pulse shaping IC with different time constants specifically to address this 12-Nov-19 05:41 PM It depends on how long a pulse is of course 12-Nov-19 05:43 PM You can pulse at lower voltages to get very high currents still. Pulsed will always give higher flux regardless 12-Nov-19 05:44 PM pileup avoidance in pulsed measurements still sounds like it'd be a no-go situation tho 12-Nov-19 05:44 PM (have also wondered how this affects ToF measurements, too) 12-Nov-19 05:44 PM oh, those diodes.. 200 attoamp dark current 12-Nov-19 05:47 PM at a very low bias surely? 12-Nov-19 05:48 PM yeah, only 1V 12-Nov-19 05:48 PM I wonder how they measure these kinds of currents 12-Nov-19 05:48 PM That's below even the best SMU range 12-Nov-19 05:48 PM still impressively small to me, for i am easily mystified 12-Nov-19 05:49 PM This of any interest? 12-Nov-19 05:49 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/6714042-EEDFA.pdf 12-Nov-19 05:49 PM fluorescent lifetime measurement 12-Nov-19 05:50 PM ooooh 12-Nov-19 05:52 PM I'll see if I can access this paper as well: https://ieeexplore.ieee.org/document/4326755 12-Nov-19 05:52 PM https://sci-hub.se/10.1109/TNS.1972.4326755 12-Nov-19 05:52 PM :P 12-Nov-19 05:52 PM scihub is a wonderful thing 12-Nov-19 05:52 PM a pulsed x-ray system that gates the electron flow 12-Nov-19 05:53 PM Ah, there you go lol 12-Nov-19 05:53 PM thanks to sci-hub having journal access is much less glamorous 12-Nov-19 05:53 PM getting stuff from ieeexplore and scinece direct used to be cool! 12-Nov-19 05:54 PM That tube shouldn't be hard to build at all 12-Nov-19 05:54 PM Essentially just a triode 12-Nov-19 05:54 PM i have sci-hub set up as a search engine in my browser, it's so very critically important 12-Nov-19 05:54 PM Just add a control grid, voltages are super low too 12-Nov-19 05:55 PM most tubes have a controllable wehnelt 12-Nov-19 05:55 PM just gate that and you're set 12-Nov-19 05:55 PM Problem solved lol 12-Nov-19 05:55 PM you'll get some electron overspray, so your rise and fall times will be weird, but it requires no modification 15-Nov-19 12:55 AM So I think I want to make a vacuum pumped acetone vapor etcher/smoother, taking hints from the 3d printer people who use acetone vapors to smooth their prints 15-Nov-19 12:55 AM Seems like my choices for vacuum pumping are either an aspirator pump (acetone into the discharge water, some water backstreaming), or get a cold trap for any old rotary vane pump. 15-Nov-19 12:55 AM Cold trap seems like something I might be able to cobble together... People online say ice and road salt can get to -40 C... Or I could get some dry ice, crush it, and make an alcohol bath 15-Nov-19 12:55 AM Any better ideas? 15-Nov-19 06:49 AM huh? acetone smoothing, vacuum? I thought everyone just used a container that can hold acetone, put a bit in the bottom, use wire to hang the part from the top of container from the lid, then just let it hang in the container, it'll slowly become saturated with vapors and you just either check every now and again or if its like a glass jar you can just see when you want to stop. 15-Nov-19 08:54 AM moin! 15-Nov-19 10:18 AM o/ 15-Nov-19 10:55 AM @Conmega yeah that's how the 3d printing people do it, but I think I need much better control over the process than they probably do. I'm trying to smooth a square edge off of ~160nm features 15-Nov-19 10:55 AM thinking more last night, the air environment probably doesn't matter, so I might not need vacuum, but probably would want a closed box that I could purge with air to stop the reaction 15-Nov-19 10:57 AM yea probably don't NEED vacuum but yea controlling that precisely would be uh... fun... 15-Nov-19 10:57 AM probably need to monitor temperature too 15-Nov-19 10:58 AM yea 15-Nov-19 10:58 AM for sure 15-Nov-19 10:59 AM do you have any links about that process? i searched a little and didn't really see much but there is a lot to sort through 15-Nov-19 10:59 AM ive seen where people use heated acetone vapors to smooth stuff instead of a sealed container...but ~160nm is super tiny to be working with 15-Nov-19 11:23 AM https://rigid.ink/blogs/news/acetone-vapor-smoothing 15-Nov-19 11:45 AM Joined the server. 15-Nov-19 12:18 PM ah, that is what i have seen done before also, sorry. 15-Nov-19 03:48 PM Idk if that's a problem in your undertaking, but with 3d prints there's overshoot because the acetone dissolves into the plastics and can't be immediately removed with the atmosphere 15-Nov-19 03:48 PM Depending on what you're working with, just using hot air might be a less dangerous approach. Using mylar sheets or tape to mask off the rest of the object. 15-Nov-19 03:48 PM Also: please think twice before you fill a vacuum chamber with acetone vapours. Thats essentially a pipe bomb 15-Nov-19 06:04 PM On the point above about cold traps, people often use acetone for the cold trap, with acetone mixed in the dry ice - it won’t freeze and is good for like -40 15-Nov-19 10:19 PM Can anyone help me with a manual for a Granville Phillips Micro-Ion E gauge? Need the interface specs, pinout and supply voltage etc. 15-Nov-19 10:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image1-1A2E2.jpg 15-Nov-19 10:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-92318.jpg 15-Nov-19 10:41 PM I found a manual that looks to be for the same style of gauge...but not sure it is that exact one 15-Nov-19 10:41 PM did you try emailing MKS? 15-Nov-19 11:02 PM Haven’t tried that yet 16-Nov-19 12:56 AM @Leona good thought on trying heat, I guess I can just suspend the item above a hotplate with a ceramic tile sitting on it to diffuse, or something 16-Nov-19 12:56 AM Yeah was reading about the acetone getting embdedded deep into the plastic, was thinking short pulses with intermediate vacuum stages with no acetone vapor to dry it out. 16-Nov-19 12:56 AM It would be pretty cool to have an acetone gas injector and watch it react in a SEM or FIB... But that's a little too harsh I think without a dedicated instrument, or bunch of specialized pumps 16-Nov-19 07:47 AM T-3:15 to my workshop and the water chiller stopped working Emergency hardware store run to connect sem to sink in progress. 16-Nov-19 07:47 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191114_172120-07DB7.jpg 16-Nov-19 07:53 AM oh man 16-Nov-19 07:53 AM good luck and have fun! 16-Nov-19 08:05 AM Yeah good luck! Still can't believe you are bringing and demoing a whole SEM setup, really awesome! 16-Nov-19 05:18 PM The SEM is probably screaming in fear given its proximity to all the big CNC equipment 17-Nov-19 01:26 PM Joined the server. 17-Nov-19 01:27 PM Welcome ^^ 17-Nov-19 01:46 PM Hey there! Lot of familiar names from my twitter feed here 17-Nov-19 02:03 PM all the cool kids hang here 17-Nov-19 02:42 PM Hi 17-Nov-19 02:42 PM Silly idea this morning: is it plausible to easily modify (a) a microwave oven magnetron or (b) a cold cathode inverted magnetron gauge as an easy sputter coating magnetron? 17-Nov-19 02:42 PM Oven magnetrons are basically free 17-Nov-19 02:42 PM The idea of running a SEM while someone next to you insists on CNC milling a sheet of particleboard is mildly horrifying 17-Nov-19 02:52 PM at first thought, based on the videos of microwave oven magnetron teardowns, I don't think it would work 17-Nov-19 02:52 PM people have made magnetrons easily enough though, even with watercooling 17-Nov-19 02:52 PM (easily if you have machine tools) 17-Nov-19 03:03 PM @a_quiet_scientist yes, it will work 17-Nov-19 03:03 PM however, it doesn't work the way you think it works 17-Nov-19 03:03 PM you will not be able to use the microwave magnetron as an RF source(too dirty, way too powerful, unmatched, hard to waveguide) - instead, you could use the MOT combined with the magnet(which is perfect for this) to make a DC magnetron 17-Nov-19 03:03 PM slap a variac onto the input of the MOT, a lightbulb in series(with the primary) to limit the power, and an ammeter in the secondary ground, reusing the big capacitor and rectifier diode to make an adjustable, high voltage, high current supply 17-Nov-19 03:13 PM hmm, ~2.5 thousand miles to bring home an SEM into a garage I feel is already overcrowded... not sure I want to do it in the next week :/ 17-Nov-19 03:14 PM I'll take it if you don't want it 17-Nov-19 03:14 PM buttt, the deal seeker in me really wants to pull the trigger 17-Nov-19 03:14 PM I seem to recall you're in UK though 17-Nov-19 03:14 PM even more miles 17-Nov-19 03:14 PM Belarus 17-Nov-19 03:14 PM ah 17-Nov-19 03:14 PM even more miles 17-Nov-19 03:16 PM buyer must remove within 7 days of purchase :/ 17-Nov-19 03:22 PM it's a SEM, go get it 17-Nov-19 03:24 PM I think I'll call a shipper tomorrow, Adam said if it's in a truck it doesn't need to be crated 17-Nov-19 03:24 PM main problem is, I've got work (flexible enough I can ignore that for the immediate consideration), I've got class twice a week (haven't been able to study outside of simply attending the lectures), and mainly I take care of my 1.5 year old most of the week 17-Nov-19 03:26 PM sounds like you don't want a sem 17-Nov-19 03:26 PM haha, more like I don't want to upset my wife too much 17-Nov-19 03:26 PM also I already have 1 SEM... but it's lower resolution than the one in question 17-Nov-19 03:28 PM all these people hoarding SEMs 17-Nov-19 03:28 PM you always need two 17-Nov-19 03:28 PM its like having only one philips screwdriver 17-Nov-19 03:45 PM Ok, that's a good point 18-Nov-19 10:25 AM Joined the server. 18-Nov-19 09:15 PM Anybody know anything about silicon photomultipliers? 18-Nov-19 09:48 PM I'm using them on a beam loss monitoring project for an electron LINAC 18-Nov-19 09:48 PM They're coupled to scintillating and regular fibers through PMMA light guides 18-Nov-19 09:56 PM I'm using photodiodes in a medical diagnostic device and my signal is really weak. Seems like it could be a straightforward replacement for improved sensitivity. 18-Nov-19 09:56 PM Do you mean avalanche photodiodes when you say silicon photomultiplier? 18-Nov-19 09:57 PM No, SiPM: https://www.ketek.net/sipm/ 18-Nov-19 10:00 PM Huh, pretty cheap, at least the raw sensor 18-Nov-19 10:00 PM I wonder how they compare to PMTs 18-Nov-19 10:05 PM I have experience with them 18-Nov-19 10:05 PM The cheap ones do not, very high dark count rates and low signal output 18-Nov-19 10:05 PM The more expensive ones are pretty alright 18-Nov-19 10:05 PM The MicroFC-60035 is around $100, a 6x6mm SiPM 18-Nov-19 10:05 PM Works very well in low-power settings 18-Nov-19 10:16 PM My signal is about 1nW and a bit tough to detect with a plain ol photodiode 18-Nov-19 10:16 PM Oh, and if you're using them in current mode, it's easier 18-Nov-19 10:16 PM Yeah SiPMs will do this 18-Nov-19 10:16 PM they're basically a drop in PMT replacement without all the bias issues 18-Nov-19 10:26 PM Thanks for the info! 18-Nov-19 10:34 PM hnnngh that link 18-Nov-19 10:34 PM I almost worked at ketek, they're really close to me 18-Nov-19 10:41 PM I saw they're in Munich. All cool stuff comes from Germany 18-Nov-19 10:42 PM hehe 18-Nov-19 10:42 PM guess you need to come here and visit 18-Nov-19 10:43 PM ...and visit the scrapyard! 18-Nov-19 10:48 PM Yes! 18-Nov-19 10:48 PM and well, "almost worked there" 18-Nov-19 10:48 PM They asked me if I want to do an internship, I said yes, never heard back from them 18-Nov-19 11:00 PM Don't call us, we'll call you 18-Nov-19 11:01 PM like 18-Nov-19 11:01 PM I applied and all 18-Nov-19 11:01 PM wrote a CV and whatnot 18-Nov-19 11:01 PM but ah well 18-Nov-19 11:01 PM what can you do 19-Nov-19 05:18 AM oof why cryopumps so £££ 19-Nov-19 05:25 AM the pump isn't the issue 19-Nov-19 05:25 AM they go for cheap once in a while 19-Nov-19 05:25 AM but the compressor 19-Nov-19 05:25 AM yikes 19-Nov-19 05:27 AM everything is yikes 19-Nov-19 05:30 AM :D 19-Nov-19 05:30 AM do you have access to a lathe? 19-Nov-19 05:30 AM then you can repair cryos 19-Nov-19 05:30 AM https://gigabecquerel.wordpress.com/2019/08/11/repairing-and-testing-a-gm-cryocooler/ 19-Nov-19 08:01 AM Nah I don't currently. Might have at some point but only moved ~2 months ago so haven't explored any local hackspaces yet 20-Nov-19 06:39 PM Joined the server. 20-Nov-19 07:25 PM heya! o/ 20-Nov-19 08:33 PM Well, everyone say hi to Sam... 20-Nov-19 09:01 PM Awesome! Hey Sam! Glad Adam was able to drag you in here. There are a few of us who are working towards silicon fab stuff at home here. :) 20-Nov-19 09:01 PM But there are also just a ton of other people doing fun HV stuff. 20-Nov-19 09:06 PM Hi! 20-Nov-19 11:27 PM hi 20-Nov-19 11:42 PM Welcome! 21-Nov-19 12:42 AM Hello 21-Nov-19 12:43 AM Moin ^^ 21-Nov-19 01:29 AM @AdamMcCombs so those varians have welch pumps in them huh? 21-Nov-19 01:29 AM The old ones yeah 21-Nov-19 01:29 AM oh wow here is a good page 21-Nov-19 01:29 AM https://brmlab.cz/project/heliovy_hledac_netesnosti/start 21-Nov-19 01:29 AM Its where I got 2 of my welch from 21-Nov-19 01:29 AM omg they have vacuum tubes in them? 21-Nov-19 01:29 AM yup 21-Nov-19 01:29 AM as i said very dead 21-Nov-19 01:29 AM heh now that's just cool 21-Nov-19 01:30 AM very very dead 21-Nov-19 01:30 AM cute little diff pump on them 21-Nov-19 01:30 AM Yeah its awful 21-Nov-19 01:30 AM Cant really clean it out 21-Nov-19 01:31 AM no real way to take the tree out? 21-Nov-19 01:31 AM https://brmlab.cz/_media/project/brmvacuum/dsc_0023.jpg 21-Nov-19 01:31 AM Oh 21-Nov-19 01:31 AM that different than mine 21-Nov-19 01:31 AM pretty! 21-Nov-19 01:32 AM yea I don't think this can do sniffing its a mass spec? I see filaments in this guy's teardown 21-Nov-19 01:32 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/h1o6Vkykd1DBhQCzlt0P5-5g8hkSF5OwiVQcEP_4fn-CF759.png 21-Nov-19 01:32 AM thats... weird 21-Nov-19 01:32 AM They are all mass spec with an analysis magnet 21-Nov-19 01:32 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/5IhbwFG73lX-aufpSnaP29lmICCsqGGmHvmgu8sQ_L-FA4FD.png 21-Nov-19 01:32 AM This was mine 21-Nov-19 01:33 AM oh god that is VERY different 21-Nov-19 01:33 AM I took it apart on a live stream years ago 21-Nov-19 01:33 AM Oh yeah it was a veco 21-Nov-19 01:33 AM not a varian now that I think about it 21-Nov-19 01:33 AM these are all varians I am looking at 21-Nov-19 01:33 AM https://brmlab.cz/_media/project/brmvacuum/20161014_134314_.jpg 21-Nov-19 01:33 AM If it was varian it would be good 21-Nov-19 01:33 AM https://brmlab.cz/_media/project/brmvacuum/20161019_011144.jpg 21-Nov-19 01:33 AM Varian is a fascinating company btw 21-Nov-19 01:33 AM yea they seem that way 21-Nov-19 01:34 AM At one point they were trying to build a engineering utopia village 21-Nov-19 01:34 AM Before they split up 21-Nov-19 01:34 AM Man I'd have to drive out to Ohio this coming weekend to get these or like closer to new years if they still had them... 21-Nov-19 01:34 AM oh jeez wow 21-Nov-19 01:34 AM I kinda hope these drop to like half what they are asking before I want to nab a bunch of them 21-Nov-19 01:34 AM the two are already marked down 100 bucks but that's still a bit much 21-Nov-19 01:34 AM Kinda bet they get bought up as soon as a local shop notices them 21-Nov-19 01:34 AM unless they dropped them off there heh 21-Nov-19 01:34 AM They are really old models though to have vacuum tubes in them... so I kinda feel like shops are just avoiding them at this point lol 21-Nov-19 02:26 AM Is there any written thing about that utopia, @AdamMcCombs ? 21-Nov-19 08:02 AM That’s a sharp looking little Cvc air cooled pump down there. Only problem with them is you can’t open them to clean them without having to do major surgery. 21-Nov-19 11:00 AM Woot finally bit the bullet and get an aperture flamer on the way. 21-Nov-19 11:00 AM Now I just need to actually go tear my column down, clean the liner and flame the apertures... 21-Nov-19 11:06 AM hi friends ! 21-Nov-19 11:09 AM Welcome :) 21-Nov-19 11:17 AM Hello! 21-Nov-19 12:05 PM Howdy! 21-Nov-19 12:05 PM @Nixie I don't. I don't know how well it was documented, one of my friends is a long time accelerator engineer from there so I've gotten some stories from him. 21-Nov-19 12:05 PM @Conmega is that just a platinum boat, or does it include a heat source and vacuum chamber? 21-Nov-19 12:06 PM Hey Sam, thanks for the response on the questions about lithography processes btw. That was me, Connor K :) 21-Nov-19 12:06 PM @nmz787 its just a little tool that you put the platinum apertures in to hold over a flame I believe its at-least platinum plated to prevent dirtying the aperture. 21-Nov-19 12:07 PM @Conmega of course! happy to talk any time, come down to new jersey this winter for a tour if you want 21-Nov-19 12:07 PM @AdamMcCombs would know most about them hehe 21-Nov-19 12:07 PM Anyone got a good needle valve, or electronic valve they could recommend? I'm trying to build one of these, probably minus the plasma 21-Nov-19 12:07 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/15743668381182138477332447906236-D01CF.jpg 21-Nov-19 12:08 PM You might want to look into mass flow controllers @nmz787 21-Nov-19 12:08 PM they're precision closed loop needle valves 21-Nov-19 12:08 PM @szeloof absolutely! I was actually talking to your brother, missed him at the MIT flea, he mentioned it would be nice if we could plan something when he's also in town. I have a busy December ahead of me, but I may be-able to stop on through on the way back from the holidays with the family in MD. 21-Nov-19 12:08 PM you won't have any calibrated values if you feed weirdness through them, but you will still have proportional control 21-Nov-19 12:09 PM Yeah i saw some last night for like $30... The one I saw said isobutane tho, wasn't sure if that was a chemical compatibility thing or just what gas it was calibrated against 21-Nov-19 12:09 PM it's mostly only calibration 21-Nov-19 12:09 PM Erik said he has a lot of MFC you could buy 21-Nov-19 12:09 PM I dont really need any specific flow rate, as it's jist volatility driving the precursor 21-Nov-19 12:09 PM All of them should have calibration tables 21-Nov-19 12:09 PM any MFC will work then, as long as your material isn't very aggressive 21-Nov-19 12:09 PM Ah, ok ,cool... Yeah lemme email erik 21-Nov-19 12:09 PM I kinda want to start with manual valves actually 21-Nov-19 12:09 PM For sake of quick prototyping 21-Nov-19 12:10 PM yea either mass flow controller or variable leak valve 21-Nov-19 12:10 PM I only would need to open close them like 8 times in one run 21-Nov-19 12:10 PM If they're easy enough to hook up to an Arduino then I'm convinced on MFC 21-Nov-19 12:10 PM I guess for manual it'd just be a stopcock? 21-Nov-19 12:11 PM Yeah they are pretty easy to use 21-Nov-19 12:11 PM @Conmega sounds great, dec or jan work for me 21-Nov-19 12:11 PM Way more repeatable than needle valve 21-Nov-19 12:11 PM Yeah they are pretty easy to use 21-Nov-19 12:11 PM Yeah they are pretty easy to use 21-Nov-19 12:12 PM most take a 0-10V input singal and output 0-10V monitoring 21-Nov-19 12:12 PM Can also have a dial on them 21-Nov-19 12:12 PM Can also have a dial on them 21-Nov-19 12:12 PM (but the control loops are inside) 21-Nov-19 12:13 PM Ah yeah so I'd at least need some voltage level shifters 21-Nov-19 12:13 PM Literally a opamp 21-Nov-19 12:14 PM Yea just a basic DAC and an opamp 21-Nov-19 12:14 PM honestly some DACs support just driving basic stuff if the load isn't crazy... 21-Nov-19 12:14 PM or a pot if you just want to control manually 21-Nov-19 12:14 PM "As the MFC takes an analog input, I was iffy about whether or not the Arduino’s PWM would work by itself (not an analog signal). Sam Zeloof helped here - told me to use an RC low-pass filter on the PWM and that’d give the desired 0-5v analog output, which worked a charm. " 21-Nov-19 12:14 PM "As the MFC takes an analog input, I was iffy about whether or not the Arduino’s PWM would work by itself (not an analog signal). Sam Zeloof helped here - told me to use an RC low-pass filter on the PWM and that’d give the desired 0-5v analog output, which worked a charm. " 21-Nov-19 12:14 PM Lol 21-Nov-19 12:14 PM Lol 21-Nov-19 12:15 PM Lol who's sam zeloof 21-Nov-19 12:17 PM Isn't that that kid who is crap with a wire bonder? 21-Nov-19 12:17 PM Haha 21-Nov-19 12:17 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_8226-A6071.JPG 21-Nov-19 12:17 PM everything is worse when you look closely 21-Nov-19 12:17 PM Andddd discord won't let me upload the tiff 21-Nov-19 12:18 PM got u 21-Nov-19 12:18 PM There we go 21-Nov-19 12:18 PM I mean like it was conductive right? 21-Nov-19 12:18 PM heh... 21-Nov-19 12:19 PM That's all you really need... 21-Nov-19 12:19 PM to be fair you picked the worst one... just don't breathe on it 21-Nov-19 12:19 PM Sam I think the crowd picked the worst one 21-Nov-19 12:19 PM This was the most overkill truck I had to use to get the sem back from supercon 21-Nov-19 12:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191119_193057-8CFD0.jpg 21-Nov-19 12:22 PM So uh... what was the diagnosis on the chiller? 21-Nov-19 12:22 PM Like that was all that was in it 21-Nov-19 12:22 PM No idea 21-Nov-19 12:22 PM Stage fright? 21-Nov-19 12:22 PM The room ac failing didn't help anything 21-Nov-19 12:22 PM uhhh 21-Nov-19 12:22 PM wow 21-Nov-19 12:22 PM Yeah 21-Nov-19 12:22 PM Well I mean 21-Nov-19 12:22 PM It was an ordeal 21-Nov-19 12:23 PM you did bring all that vacuum equipment in, scared the compressors in the room I guess 21-Nov-19 12:23 PM No 21-Nov-19 12:23 PM It was literally an ice cube 21-Nov-19 12:23 PM A AC unit sized ice cube 21-Nov-19 12:23 PM oh... then you made it try extra hard to make you think it was better at compressing than your pumps were at vacuuming I guess 21-Nov-19 12:23 PM Just how does it fail like that... worst case if all control is lost cycle the breaker? 21-Nov-19 12:24 PM Yeah so the plumb the Microscope up to the sink option worked well 21-Nov-19 12:24 PM that option always works well 21-Nov-19 12:24 PM also works on helium compressors to make LOX 21-Nov-19 12:24 PM :P 21-Nov-19 12:25 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191118_132049-6C5E1.jpg 21-Nov-19 12:25 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191118_132052-364F5.jpg 21-Nov-19 12:25 PM The problem was there was a water hammer issue if the flow of the sink was to low 21-Nov-19 12:26 PM heh... 21-Nov-19 12:26 PM https://pbs.twimg.com/media/EB5_-5kXYAAkstH?format=jpg 21-Nov-19 12:27 PM So it rudely interupted a few talks 21-Nov-19 12:27 PM Also leme tell you, Styrofoam cups burn good when full of blue liquid 21-Nov-19 12:27 PM Lol 21-Nov-19 12:27 PM Pyro much? 21-Nov-19 12:28 PM I just didn't really know what else to do with it at the time... It was poorly planned first time playing with liquid oxygen/air/whatever 21-Nov-19 12:28 PM I mean... I at-least got video 21-Nov-19 12:29 PM What no liquid ozone? 21-Nov-19 12:29 PM Lame 21-Nov-19 12:29 PM omg... I watched one video about that stuff, some crazy auzzie making it... all I had to know about it 21-Nov-19 12:29 PM although I am tempted 21-Nov-19 12:29 PM But the fact that even NASA said, yeaaa nope, too 'splody, is probably a good sign to stay away 21-Nov-19 12:31 PM I mean NASA has a very low risk tolerance 21-Nov-19 12:32 PM yet nitrogen tetroxide is super safe in comparison and fine 21-Nov-19 12:33 PM Does liquid ozone have any better of a specific impulse though? 21-Nov-19 12:34 PM its a higher density oxidizer? but the problem is it makes litterally everything explosive 21-Nov-19 12:34 PM LOX makes everything flammable, liquid ozone makes everything explosive pretty much all you need to know 21-Nov-19 01:05 PM I wonder which compounds become hypergolic with lox 21-Nov-19 08:52 PM lol at that truck pic 21-Nov-19 08:52 PM No response from my NASA spaceflight mass spectrometer assembler job, yet 21-Nov-19 08:52 PM which may be a good thing, actually reviewing vs "sorry you are still a student and we need someone ASAP" 22-Nov-19 05:51 AM http://www.high-light.com.tw/upload/website/home_kv/index/htcvacuum-vacuum-chambers.jpg 22-Nov-19 06:42 AM what is that poster? 22-Nov-19 07:26 AM the text is funny 22-Nov-19 07:26 AM "WE MAKE YOU NEED Vacuum Chamber" 22-Nov-19 07:26 AM it's from http://www.high-light.com.tw/en-global 22-Nov-19 07:26 AM a taiwaneese vacuum stuff vendor 22-Nov-19 07:26 AM and reseller 22-Nov-19 09:54 AM If anyone here is a C/C++ and math wizard, would you like to contribute to the project in #machining? 22-Nov-19 09:54 AM I'm not sure I can do this myself lol 22-Nov-19 04:20 PM I'm not a wizard, but I own a tool at work that has C as one of the languages 22-Nov-19 04:20 PM I know a wizard however, and can effectively direct questions to him 22-Nov-19 04:20 PM I also happen to be in a vector calculus class right now... 22-Nov-19 04:20 PM About 3 weeks away from it being over 22-Nov-19 04:20 PM Aforementioned wizard is wizard-y in C/C+++/math/logic/other programming languages too 23-Nov-19 09:51 AM moin! 24-Nov-19 04:47 AM Ugh, well went down to the basement the other day to a roughing pump leaking on the floor... One I was using for my test bench too :/ 24-Nov-19 04:47 AM Like a drop every now and again... so super slow, guessing the cork main seal is seeping slowly... Great. 24-Nov-19 04:47 AM It was a "rebuilt" pump that probably sat in a closet for 15 years so its not suprising... Will have to see if I can just cut a new main seal since I'd hope the rest of it is alright still. 25-Nov-19 06:58 AM I still dont know if i have a leak or outgassing problem. 25-Nov-19 06:58 AM I reach 10 Pa with my double stage pump 25-Nov-19 06:58 AM And 0.6 Pa with the diffusion pump 25-Nov-19 06:58 AM At this vacuum level i dont know what is the most probable cause 25-Nov-19 06:58 AM Maybe the diffusion pump must be perfectly levelled? 25-Nov-19 07:07 AM diff pumps have to be vertical as far as I know... like a very very slight angle won't hurt anything, like a few degrees... but it can't be at like a 45 degree angle... 25-Nov-19 07:09 AM My diffusion pump is vertical. Maybe not perfectly vertical. 25-Nov-19 07:10 AM then you must have some kind of leak or bad outgassing 25-Nov-19 07:10 AM you should easily shoot down to below 0.01 Pa 25-Nov-19 07:10 AM really settling down somewhere in the 0.001-0.0001 Pa range 25-Nov-19 07:10 AM What is the chamber built with? 25-Nov-19 07:13 AM I made it with stainless Steel. Tig welded. And i used silicone for sealing the door 25-Nov-19 07:13 AM Is a rectangular Chambers 25-Nov-19 07:13 AM So i dont found viton orings 25-Nov-19 07:23 AM well you can take a round ring and if you make some kind of grove to lay it in with rounded corners you could use a standard viton ring 25-Nov-19 07:23 AM silicone I think outgasses a bit and if you layed it down yourself may be difficult to ensure its perfect, if you cut it out of a sheet maybe? 25-Nov-19 07:23 AM there are also viton sheets 25-Nov-19 07:23 AM do you have photos of your build? I'd love to see it and also someone here might be-able to point out something if its obvious 25-Nov-19 07:29 AM Thanks @Conmega !!. I will show you some pictures later. 26-Nov-19 08:14 PM @chucrut are you sure it's not your pump, or your vacuum gauge? 26-Nov-19 08:14 PM But if a diffpump powering up manages to drop the pressure lower than the forepump, I'm thinking that it's a damaged pump, or when the diffpump starts, the oil backstreaming contaminates the gauge and makes it read lower than it actually is(somehow, but I can't think of a way it would read lower instead of higher) 26-Nov-19 08:14 PM I also want to see your chamber, because if you welded it from the outside, you've destroyed your chances at getting a low enough vacuum because of virtual leaks, but that's a worry for later. 26-Nov-19 09:17 PM I think he posted a photo of his chamber awhile ago and he had a rather thick silicone gasket that had been made with what seemed to be construction silicone... 26-Nov-19 09:17 PM That is probably the issue more than anything 26-Nov-19 09:17 PM Oh right I found it in the search...it is some rubber sheet and then construction silicone 26-Nov-19 11:24 PM Wheeee... that long lost MKS-901P transducer arrived! 26-Nov-19 11:24 PM Only took what... three months? 26-Nov-19 11:24 PM Even threw in a free KF16 centering ring and o-ring seal 26-Nov-19 11:24 PM My universal vacuum station controller* will have MKS protocol support after all! 26-Nov-19 11:24 PM (*date of existence TBD) 26-Nov-19 11:24 PM Hefty bit of kit for its size! 27-Nov-19 01:14 AM Hi @Deleted User I'm thinking breaking a lightbulb and turn it on in the vacuum chamber. Maybe if the filament last 10 hours the vacuum is okay 27-Nov-19 01:15 AM That's an awful way to check the vacuum level 27-Nov-19 01:15 AM Not to mention light bulbs work close to atmosphere, just with no oxygen. 27-Nov-19 01:16 AM You mean with a gas? 27-Nov-19 01:16 AM At atmospheric pressure 27-Nov-19 01:16 AM or just below 27-Nov-19 01:17 AM I thought old lightbulbs works in vacuum 27-Nov-19 01:17 AM No, just an inert gas fill 27-Nov-19 01:17 AM Usually not full atmospheric pressure, so technically a vacuum, but it's many orders of magnitude higher than you'd need for any practical experiments 27-Nov-19 01:19 AM The gas helps regenerate the filament. 27-Nov-19 01:20 AM Damn Thomas Edison 27-Nov-19 01:20 AM There's no filament regeneration 27-Nov-19 01:20 AM The gas prevents sputtering and evaporation of the filament onto the glass bulb, as well as cooling it down through convection 27-Nov-19 01:22 AM But a lightbulb under vacuum should last some hours or not? 27-Nov-19 01:22 AM Sure, it'll probably burn up all the remaining oxygen and then last for a very long time 27-Nov-19 01:22 AM But it'll last a very long time even in a bad vacuum 27-Nov-19 01:34 AM @chucrut did you ever find out what kind of rubber that was exactly you are using for half of your seal? 27-Nov-19 01:43 AM @LRM I'm using construction neutral silicone. I hope outgassing is low 27-Nov-19 01:44 AM No i mean the black rubber material in the photos from awhile back? 27-Nov-19 01:44 AM Or are you just using the silicone now 27-Nov-19 01:47 AM I removed the black rubber. So I now only have the silicone 27-Nov-19 01:47 AM It was a bad idea to have to seals 27-Nov-19 01:47 AM 2 seals 27-Nov-19 02:13 AM @Deleted User from wikipedia: 27-Nov-19 02:13 AM The role of the gas is to prevent evaporation of the filament, but the fill must be chosen carefully to avoid introducing significant heat losses. For these properties, chemical inertness and high atomic or molecular weight is desirable. The presence of gas molecules knocks the liberated tungsten atoms back to the filament, reducing its evaporation and allowing it to be operated at higher temperature without reducing its life. 27-Nov-19 02:13 AM Of course, its wikipedia so I have no way to fully confirm, but I just remembered reading about filament regeneration. 27-Nov-19 02:13 AM (somewhere else, not there) 27-Nov-19 11:15 AM Yeah, so no regeneration. 27-Nov-19 11:15 AM Just preventing it from destroying itself. 27-Nov-19 11:37 AM Halogen bulbs have gas filling for filament regeneration, allowing them to be driven hotter 27-Nov-19 02:18 PM Well, if the metal filament boils off, that is destruction, if the gas causes the metal to bounce back and redeposit, that seems like it would qualify as regeneration 27-Nov-19 03:39 PM the atoms don't actually leave the filament afaik. It's maybe comparable to vapor pressure? 27-Nov-19 03:39 PM if the lone wolfram got out, there's no putting it back in the lattice 27-Nov-19 04:21 PM Yes, it's mostly vapor pressure 27-Nov-19 04:21 PM Plus convection 27-Nov-19 05:00 PM What's the difference between a vapor and liberated free atoms?? 27-Nov-19 05:00 PM One you prevent, the other you force 27-Nov-19 05:00 PM (usually) 27-Nov-19 05:04 PM Ah 27-Nov-19 05:04 PM Hmm, the sputter coater here at my part-time has an mdp5011 drag pump on it 27-Nov-19 05:05 PM Everyone has a 5011! 27-Nov-19 05:05 PM Except me :( 28-Nov-19 10:54 AM happy thanksgiving to my fellow 'muricans 30-Nov-19 04:09 PM https://www.youtube.com/watch?v=nIKhUizkXxA 30-Nov-19 04:09 PM Jus' drop this here~ 30-Nov-19 04:23 PM I have a feeling Ben would feel at home here 30-Nov-19 04:23 PM As would Marco 30-Nov-19 04:35 PM Haha 30-Nov-19 06:06 PM Watched that video earlier, was quite good 01-Dec-19 06:16 AM Joined the server. 01-Dec-19 06:17 AM Joined the server. 01-Dec-19 07:14 AM Hey @robotgrrl ! Welcome! 01-Dec-19 07:15 AM Hello @Nixie! I know hardly anything about electron microscopes, but had the chance to see @AdamMcCombs's SEM at Supercon and am hooked to learn more! 01-Dec-19 07:30 AM He's the master ^^ 01-Dec-19 07:30 AM I briefly meet you last year at the supercon. 01-Dec-19 07:30 AM hope you enjoy being here, Adam posts amazing things about EM's (and the other people does amazing things too) 01-Dec-19 07:54 AM best way to learn is simply buying an old one and using it 01-Dec-19 07:54 AM I guess @AdamMcCombs knows the market for old electron microscopes in the US as an expert, right? 01-Dec-19 07:54 AM need more scopes 01-Dec-19 10:15 AM Can never have enough SEMs 01-Dec-19 03:01 PM lol @ applied science "well, first of all, this is not a high end vacuum system" 01-Dec-19 03:01 PM it's actually interesting, that you need less vacuum for shorter distances, ie, less chance of bumping into something else 01-Dec-19 03:01 PM I read a paper on a pocket/field mass spec before.. ToF/distance on the order of under 30cm 01-Dec-19 03:03 PM 10^-4 is within the range of a very good forepump 01-Dec-19 03:03 PM so he's right 01-Dec-19 03:04 PM does look like he has a filter on the fore of the roughing pump too (you dont want any of the vacuum oil to get inside the sample chamber) 01-Dec-19 03:04 PM Hi. I read some people replace CF copper gasket by viton gasket. 01-Dec-19 03:05 PM That's possible, but you're nowhere near needing conflat. 01-Dec-19 03:05 PM Get your vacuum down to a reasonable level first. 01-Dec-19 03:06 PM Anyone knows if viton gasket can be round section? 01-Dec-19 03:06 PM Or need to be flat? 01-Dec-19 03:06 PM It gets crushed 01-Dec-19 03:06 PM Either works 01-Dec-19 03:06 PM I was surprised by the lack of a metal frame over his turbo... He always seems to put so much effort into things and then that was glaring at me as a safety miss 01-Dec-19 03:07 PM Metal frame? 01-Dec-19 03:07 PM Like in case of failure 01-Dec-19 03:07 PM Turbos don't explode 01-Dec-19 03:07 PM Ummm 01-Dec-19 03:07 PM Yyyyeaaa 01-Dec-19 03:07 PM or 'walking' away? 01-Dec-19 03:08 PM Not until you get into the 90kg 20krpm 10-20-grenades-worth-of-kinetic-energy kind of turbos 01-Dec-19 03:08 PM Aren't all turbos running at like 40-70krpm?? 01-Dec-19 03:08 PM but the mass is lower for small ones 01-Dec-19 03:08 PM Today I removed some silicone and replaced by another polymer and outgassing lowered. Now I reach 0.47 Pa 01-Dec-19 03:08 PM is the point, I think 01-Dec-19 03:08 PM The largest turbos spin as low as 20-25krpm 01-Dec-19 03:08 PM the housings are large enough to comfortably sit inside of 01-Dec-19 03:08 PM the smallest turbos spin at 90krpm 01-Dec-19 03:08 PM the real smallest turbos spin up to 120krpm, but those are super rare and not very useful 01-Dec-19 03:12 PM Hmm I guess coming from Intel here, I've mainly heard horror stories about fab equipment maintenance and failure 01-Dec-19 03:12 PM fab equipment has those turbos large enough to sit inside of. 01-Dec-19 03:12 PM but most of the time, if a turbo fails, you have a dead turbo and lots of sadness 01-Dec-19 03:12 PM if a mid-sized turbo fails, it can try running away 01-Dec-19 03:12 PM shearing the bolts off 01-Dec-19 03:12 PM if a large sized turbo fails a) you're fired b) you'll need health insurance 01-Dec-19 03:12 PM but the large size turbos are very very expensive and very heavy 01-Dec-19 03:23 PM I want to put a viton gasket here 01-Dec-19 03:23 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20191201_202552-4C7DF.jpg 01-Dec-19 03:23 PM What equipment do you have that has CF flanges? 01-Dec-19 03:24 PM I ordered CF fittings, but they have a leak 01-Dec-19 03:24 PM For? 01-Dec-19 03:25 PM For an electron gun 01-Dec-19 03:25 PM You can't put a regular viton o-ring there. You also don't need CF for an electron gun. 01-Dec-19 03:26 PM If it's an FESEM you do 01-Dec-19 03:26 PM he can't get below .1Pa 01-Dec-19 03:26 PM he's not building a SEM 01-Dec-19 03:27 PM Do you suggest crush the viton gasket with the knife.edge? 01-Dec-19 03:27 PM You need to order special viton gaskets for CF flanges 01-Dec-19 03:27 PM Just buy copper 01-Dec-19 03:28 PM Okay. A thicker copper 01-Dec-19 03:28 PM No, you need to buy the right thickness oxygen-free copper. 01-Dec-19 03:28 PM Only reason to use viton is if the knife edge is damaged 01-Dec-19 03:28 PM But I see no reason for you to be using CF when you can barely get a vacuum 01-Dec-19 03:28 PM Gotta learn to walk before you learn to fly 01-Dec-19 03:28 PM Well isn't viton much cheaper and reusable? 01-Dec-19 03:28 PM It's not very reusable for CF 01-Dec-19 03:28 PM Maybe 2-3 times 01-Dec-19 03:28 PM With a bit of annealing you can do the same with copper. 01-Dec-19 03:29 PM Ah 01-Dec-19 03:29 PM I think individually the copper ones are actually cheaper too but you have to buy them 20 at a time? 01-Dec-19 03:29 PM Been awhile since I looked last 01-Dec-19 03:29 PM Sure, but they're disposable 01-Dec-19 03:29 PM Still very cheap, maybe a few dollars a piece for the large ones 01-Dec-19 03:29 PM I got a pack of however many CF1.33" gaskets for $5 or so, I have a whole ribbon full of them. 01-Dec-19 03:31 PM So viton definitely works just fine in conflat, I use it on the regular 01-Dec-19 03:31 PM I don't think you can crush regular KF sized viton orings though 01-Dec-19 03:31 PM One particular system I have probably used the same oring at least 20 times 01-Dec-19 03:31 PM Oh yeah no 01-Dec-19 03:31 PM I don't even think the kf and cf o-rings line up 01-Dec-19 03:31 PM ID wise 01-Dec-19 03:32 PM They do for some, but they're painfully oversized 01-Dec-19 03:32 PM If you're in the US I like ordering from global o-ring 01-Dec-19 03:32 PM @AdamMcCombs do you crush the viton with the knife edge? 01-Dec-19 03:32 PM Or with the flat edge? 01-Dec-19 03:33 PM Flat 01-Dec-19 03:33 PM It might get squished a but by the knife 01-Dec-19 03:33 PM Should squeeze out to fill the whole space 01-Dec-19 03:33 PM There should be a spec out there for copper replacement viton 01-Dec-19 03:33 PM Like the drawing? 01-Dec-19 03:33 PM Let me find it 01-Dec-19 03:33 PM https://www.ldsvacuumshopper.com/conflanvitga.html 01-Dec-19 03:33 PM Yeah like the drawing 01-Dec-19 03:33 PM A bit more contact but very similar 01-Dec-19 03:36 PM They are square orings 01-Dec-19 03:36 PM I've been using the same viton gasket for my system on the 6 " conflat ports for a while now. Opened and closed at least 20 times now, no leaks or issues at all 01-Dec-19 03:37 PM Can I do the same with round orings? 01-Dec-19 03:38 PM If you can find perfect round viton orings in that size... maybe 01-Dec-19 03:38 PM But... why? 01-Dec-19 03:38 PM Round can be easier to source 01-Dec-19 03:38 PM In vacuum rated viton? 01-Dec-19 03:38 PM I use the square cross section ones. Circular will still work 01-Dec-19 03:38 PM Square is easier to manage in this case though 01-Dec-19 03:39 PM Viton is pretty much vacuum rated by default lol 01-Dec-19 03:39 PM Yeah you can get nearly any size viton 01-Dec-19 03:39 PM Fair enough 01-Dec-19 03:39 PM Never have had a problem finding the right oring 01-Dec-19 03:39 PM Just some vacuum suppliers prebake to remove volatiles, but a general viton oring will do the job 01-Dec-19 03:40 PM Also you don't really need oxogen free copper most of the time 01-Dec-19 03:40 PM It's easier to find in conflat sizes 01-Dec-19 03:40 PM ? 01-Dec-19 03:40 PM Most places sell both 01-Dec-19 03:40 PM Really? What for? 01-Dec-19 03:41 PM https://www.globaloring.com/ 01-Dec-19 03:41 PM "Good gasket" and "slightly worse gasket but a hair cheaper"? 01-Dec-19 03:41 PM https://www.theoringstore.com/ 01-Dec-19 03:41 PM Square orings are for edge knife crushing? 01-Dec-19 03:41 PM It's not worse for every application 01-Dec-19 03:41 PM Conflat is useful for a lot more than just uhv 01-Dec-19 03:41 PM Sometimes the mechanical properties are nicer 01-Dec-19 03:41 PM Sometimes assembly is better 01-Dec-19 03:42 PM If you look at the square ones, you will actually see the edges are slightly chamfered to match the conflat sealing angle as well. Square orings exist in general for a variety of purposes 01-Dec-19 03:42 PM Sometimes it's just thermal constraint 01-Dec-19 03:44 PM One thing I like about conflat is that it's a mechanical joint 01-Dec-19 03:44 PM But price and assembly time is hard to get around 01-Dec-19 03:45 PM @chucrut is one of the knife edges damaged? 01-Dec-19 03:45 PM No damage knife. But the crushing is not uniform 01-Dec-19 03:46 PM Hm 01-Dec-19 03:46 PM In what way? 01-Dec-19 03:46 PM Probably using oversized orings 01-Dec-19 03:46 PM So it have a leak 01-Dec-19 03:47 PM What method are you using to tourque the bolts? 01-Dec-19 03:48 PM Little crushing at one side 01-Dec-19 03:48 PM Show us pictures of your flanges and how your orings fit in them 01-Dec-19 03:49 PM No method 01-Dec-19 03:49 PM Just my hands and a wrench 01-Dec-19 03:49 PM The opposite bolts 01-Dec-19 03:49 PM Unless it's completely the wrong size by quite a bit it's pretty hard to get the copper the wrong size 01-Dec-19 03:49 PM I don't think he's using copper 01-Dec-19 03:50 PM Are you going full tourque the first time around or gradually applying force? 01-Dec-19 03:50 PM Oh yeah the way I read that all your using copper right now but I could be mistaken? 01-Dec-19 03:51 PM I'm using the right size copper gasket 01-Dec-19 03:51 PM Not so dumb 01-Dec-19 03:51 PM I'm gradually applying force to the opposite bolts 01-Dec-19 03:51 PM In that case you shouldn't have any leaks 01-Dec-19 03:51 PM Try just going in a circle 01-Dec-19 03:51 PM Also, how are you testing it? You said your vacuum system doesn't reach below 0.47Pa 01-Dec-19 03:51 PM That's the actual spec in a lot of cases 01-Dec-19 03:52 PM Okay. I will try applying forcein a circle. 01-Dec-19 03:52 PM Thanks Adam !! 01-Dec-19 03:53 PM Make sure it closes all the way too 01-Dec-19 03:53 PM Or at least almost all the way, my 1.33" has ~100um of spacing left 01-Dec-19 03:53 PM It no close 01-Dec-19 03:54 PM Hm yeah that's a bit odd 01-Dec-19 03:54 PM It have like 1mm separation 01-Dec-19 03:54 PM That's very wrong 01-Dec-19 03:54 PM I've done conflat using tourque specs and complete compression specs 01-Dec-19 03:54 PM Both work in practice 01-Dec-19 03:55 PM The flanges must meet or be close to meeting, so either your gasket is the wrong size or installed incorrectly 01-Dec-19 03:55 PM Not necessarily 01-Dec-19 03:55 PM 1mm is close to the thickness of a gasket 01-Dec-19 03:55 PM So maybe just a little more torque is needed? 01-Dec-19 03:55 PM I think the copper is crushed nice. 01-Dec-19 03:55 PM If you use tourque specs you can have much larger spaces and still be assured you have a good seal 01-Dec-19 03:56 PM Maybe the method is wrong 01-Dec-19 03:56 PM But you need a really good touch or a torque wrench to pull that off 01-Dec-19 03:56 PM So is it 1mm all the way around? 01-Dec-19 03:56 PM What size conflat is this? 01-Dec-19 03:57 PM Yes 01-Dec-19 03:57 PM Like 50mm diameter. 01-Dec-19 03:57 PM 2" then 01-Dec-19 03:57 PM Ok so pretty small 01-Dec-19 03:57 PM The gasket should kinda sit in the grouve on both sides of the mate 01-Dec-19 03:58 PM Like 6 or 8 bolts 01-Dec-19 03:58 PM My gasket filled the entire groove 01-Dec-19 03:58 PM With a bit of wiggle 01-Dec-19 03:59 PM With the bolts out you can move the thing around and feel it kinda click into place 01-Dec-19 03:59 PM Yes 01-Dec-19 03:59 PM Does yours do that? 01-Dec-19 03:59 PM Hm 01-Dec-19 03:59 PM Yes. The gasket feels well fitted 01-Dec-19 03:59 PM I'm still curious about the test system, how do you know you have a leak? 01-Dec-19 03:59 PM It sounds like you're doing everything right with the flange itself 01-Dec-19 04:00 PM Do you keep going around and applying tourque until the bolts remaining tight? 01-Dec-19 04:00 PM I put silicone in the copper gasket. And the pressure drop from 2600 pa to 0.5 Pa 01-Dec-19 04:01 PM No... why would you do that... 01-Dec-19 04:01 PM What? Did you reuse the copper gasket? 01-Dec-19 04:01 PM When you say you put silicone in was that while the system was under vacuum? 01-Dec-19 04:02 PM No 01-Dec-19 04:02 PM So you pulled it apart and applied it to both sealing surfaces? 01-Dec-19 04:03 PM It was a separate test 01-Dec-19 04:03 PM Looking for leaks 01-Dec-19 04:03 PM I put silicone everywhere. Now I have a outgassing problem with so many silicone 01-Dec-19 04:03 PM Also I have the same question as mason 01-Dec-19 04:03 PM Yes 01-Dec-19 04:03 PM Forget silicone exists for your foreseeable future in vacuum building 01-Dec-19 04:03 PM It's not your friend 01-Dec-19 04:03 PM Ok there is the problem 01-Dec-19 04:03 PM I put silicone both sides of the copper gasket 01-Dec-19 04:04 PM Yeah, just get new copper gaskets each time you pull the flange off. If that costs too much, get viton gaskets from the o-ring store or LDS 01-Dec-19 04:04 PM Reusing copper is possible but it takes a bit of care 01-Dec-19 04:04 PM It's never going to be consistent 01-Dec-19 04:06 PM Yeah if you always use new copper on clean undamaged conflat and follow a valid tourque procedure you're pretty much guarented sucsess 01-Dec-19 04:06 PM you don't put grease on copper, you install those dry... 01-Dec-19 04:06 PM Yeah also very much that 01-Dec-19 04:06 PM I have plenty of copper gaskets 01-Dec-19 04:06 PM I will try the circle method tomorrow 01-Dec-19 04:06 PM Conflat relies on the metal on metal interface 01-Dec-19 04:07 PM Also most copper you pull off stuff used will have been torqued to full depth of cut, only way you can try to reuse them is if you install one new and torque it to a certain torque, make sure it seals well, then when you de-install torque it further... 01-Dec-19 04:07 PM The distortion and then the residual strees in the copper wanting to shrink back on the stainless is what makes it work 01-Dec-19 04:07 PM but for small stuff its so cheap anyway... even the large stuff its not too expensive 01-Dec-19 04:08 PM Using viton in conflat is a bit more finiky 01-Dec-19 04:08 PM And by a bit I mean kinda a pain 01-Dec-19 04:08 PM and more expensive, but they are reusable 01-Dec-19 04:08 PM the formed viton rings anyway 01-Dec-19 04:08 PM Especially when mounted vertical 01-Dec-19 04:08 PM if your just using orings... uhm eh... good luck 01-Dec-19 04:08 PM https://www.ldsvacuumshopper.com/coppergaskets.html 01-Dec-19 04:08 PM Be sure to clean the silicone off the conflat before you try again 01-Dec-19 04:08 PM I'm still thinking that he's using a very bad vacuum system in general 01-Dec-19 04:09 PM for example 10 pack of rings for 6" conflat is 46 bucks... so 4.60 a pop... 01-Dec-19 04:09 PM really not that bad 01-Dec-19 04:09 PM if your opening it every 5 seconds it bad but at that rate get a gate valve for 100-200 bucks 01-Dec-19 04:09 PM Grease in there with prevent the metal on metal seal 01-Dec-19 04:09 PM that too 01-Dec-19 04:10 PM I mean if it's conflat what's wrong with it? 01-Dec-19 04:10 PM The rest of it 01-Dec-19 04:10 PM Also it's totally possible to hack together the worst vacuum system into some completely functional 01-Dec-19 04:10 PM 2.6kPa on a completely sealed system with no chamber? 01-Dec-19 04:10 PM Seems wrong 01-Dec-19 04:11 PM The crushing is not uniform 01-Dec-19 04:11 PM Pictures? 01-Dec-19 04:11 PM Did you start at a low tourque then go up? 01-Dec-19 04:12 PM Think a circle 01-Dec-19 04:12 PM At the right too much crushing 01-Dec-19 04:12 PM At the left little crushing 01-Dec-19 04:12 PM Yes. I started from low torque and slowly applying more torque in opposite bolts 01-Dec-19 04:12 PM Just go around in a circle this time 01-Dec-19 04:12 PM Don't bother with the opposite thing 01-Dec-19 04:13 PM Okay 01-Dec-19 04:13 PM Starting out just go around to get the bolt slightly snug 01-Dec-19 04:13 PM The gradually increase force on each one 01-Dec-19 04:13 PM yup 01-Dec-19 04:13 PM The goal is to not get one side to compress before the others 01-Dec-19 04:13 PM Anyways back to stories of bad vacuum systems 01-Dec-19 04:13 PM @Conmega can share what I did to his sem 01-Dec-19 04:15 PM Some overall photos of your system might help diagnose the issues in the future, @chucrut 01-Dec-19 04:15 PM Yeah photos are worth a lot 01-Dec-19 04:15 PM Allow us to catch stuff we might not think to ask about 01-Dec-19 04:16 PM I am wondering if the issue might be something with the way the two flanges are coming together and not so much an issue with torque 01-Dec-19 04:16 PM I know 01-Dec-19 04:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190218_181421-B4060.jpg 01-Dec-19 04:19 PM Example this vacuum seal 01-Dec-19 04:19 PM It's still a great seal 01-Dec-19 04:19 PM Just unconventional 01-Dec-19 04:19 PM You've got a KF cap, seal, probably a centering ring in there 01-Dec-19 04:20 PM sanded down centering ring 01-Dec-19 04:21 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180528_013117-DE197.jpg 01-Dec-19 04:21 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20180528_013105-6C991.jpg 01-Dec-19 04:21 PM Or this type of thing 01-Dec-19 04:21 PM Juicy 01-Dec-19 04:21 PM Something something jb weld and paint something something welder you ain't 01-Dec-19 04:21 PM Transist damaged the welds in the manifold quite badly 01-Dec-19 04:21 PM I guess it's fine to use epoxy to seal small cracks 01-Dec-19 04:22 PM You can epoxy flanges together in a pinch 01-Dec-19 04:22 PM Totally works 01-Dec-19 04:22 PM Then you get yelled at in retrospect 01-Dec-19 04:22 PM In this case though jb weld didn't work 01-Dec-19 04:22 PM It was to ridged so I went and got 10 minute epoxy from the hardware store and that worked 01-Dec-19 04:22 PM Eh 01-Dec-19 04:22 PM Or you get rewarded for it 01-Dec-19 04:24 PM I mean when someone tries to take the flanges apart 01-Dec-19 04:24 PM Fixing a vacuum leak on production in record time and sometimes without having to break vacuum on a system is definitely worth it 01-Dec-19 04:25 PM I was thinking. The difference between the best vacuum in the world and a crappy vacuum is just 1 Pa 01-Dec-19 04:25 PM There's a reason it's measured in orders of magnitude 01-Dec-19 04:25 PM Lol 01-Dec-19 04:25 PM Yup 01-Dec-19 04:25 PM Explaing that to people is fun 01-Dec-19 04:25 PM The amount of money efferort and time spent to remove that last .0000000000001% is so much greater than even the .000001 01-Dec-19 04:25 PM The funny ones are when someone is afraid that a uhv system is going to implode 01-Dec-19 04:25 PM Because of how high of a vacuum it is 01-Dec-19 04:31 PM Then the 1% analogy works 01-Dec-19 04:31 PM Exactly that's why I use it 01-Dec-19 04:32 PM People are used to dealing with pressures 01-Dec-19 04:32 PM In which case 1000% is a lot bigger than 1% 01-Dec-19 04:32 PM 1000% fewer molecules than 0.00001% is a almost nothing 01-Dec-19 04:32 PM (but it ends up costing 1000% more lol) 01-Dec-19 08:50 PM Helium still used as the leak detector dealio? or some other method 01-Dec-19 08:57 PM It is. 01-Dec-19 08:57 PM Mass separation calibrated for helium detection, single-channel mass spec 02-Dec-19 10:10 AM Yep, interesting thing to use. 02-Dec-19 10:12 AM But you don't need a helium leak detector to build a helium leak detector 02-Dec-19 10:12 AM RGAs often even have built-in leak detector modes 02-Dec-19 10:12 AM (much cheaper!) 02-Dec-19 10:25 AM well RGAs are much cheaper SOMETIMES 02-Dec-19 10:25 AM RGA for 200 bucks or an entire leak detector station for 200 bucks... 02-Dec-19 10:26 AM Leak detectors are generally huge 02-Dec-19 10:26 AM RGAs can be shipped around easily 02-Dec-19 10:26 AM sure, but you need to attach those to at-least a turbo and roughing pump 02-Dec-19 10:26 AM even with small roughing pumps your going to get some bulk 02-Dec-19 10:26 AM Chances are you have them already though 02-Dec-19 10:27 AM Right sure, either way I'd say do what makes the most sense for your space/money/availability nearby 02-Dec-19 10:27 AM Unless you're like.... a paranoid perfectionist plumber 02-Dec-19 10:27 AM if you have the parts build one, if not and one shows up buy one 02-Dec-19 10:27 AM If a full leak detector is available cheaply, definitely going for one is good 02-Dec-19 12:21 PM Full on leak detectors are useful in much much wider variety of pressures, and can often be attached to the roughing side of a system making it so you don't have to break vacuum on the chamber 02-Dec-19 12:21 PM Now depending on the device setup a full detector might have less sesetivity or a long delay in that type of config, but they can also be ran in a sniffer mode or a much lower vacuum and then use counter flow in a turbo or diff pump to act as a mass filter for helium while keeping the ion gun and analyzer head under high vacuum 02-Dec-19 12:21 PM In those modes they are way more sensitive than RGA and can even help with bulk leaks 02-Dec-19 12:26 PM Yeah, if a proper leak detector is available, I'd go for it, but as far as I've seen they're quite rare overall 02-Dec-19 12:26 PM Especially in working condition 02-Dec-19 12:26 PM Now that being said I love RGAs... 02-Dec-19 12:26 PM They really aren't that uncommon 02-Dec-19 12:26 PM Maybe more common in the US 02-Dec-19 12:26 PM Here I can barely find vacuum-related anything, let alone a leak detector or mass spec 02-Dec-19 12:27 PM Yeah I'm guessing shipping a rga overseas is easier then? 02-Dec-19 12:27 PM Well yes, a fridge versus a small box 02-Dec-19 12:28 PM They come a lot smaller than fridge sized 02-Dec-19 12:28 PM Mini fridge 02-Dec-19 12:28 PM Way smaller 02-Dec-19 12:28 PM Either way it's a pallet item at that point 02-Dec-19 12:28 PM Or it's newer/smaller and expensive 02-Dec-19 12:28 PM Not really 02-Dec-19 12:28 PM There's this really common leybold model that uses a counter flow turbo that's like twice the size of a RV 12 02-Dec-19 12:30 PM Hm 02-Dec-19 12:30 PM But it's still damn heavy 02-Dec-19 12:30 PM So I get how shipping would suck 02-Dec-19 12:30 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/V10995-440_1-8BC19.jpg 02-Dec-19 12:33 PM That looks modern 02-Dec-19 12:33 PM Not the smallest one but on the smaller end 02-Dec-19 12:33 PM Yeah but I see these surplus a lot 02-Dec-19 12:37 PM I'm guessing they don't cost less than $1000 02-Dec-19 12:38 PM I've seen them go that cheap 02-Dec-19 12:38 PM "that cheap" 02-Dec-19 12:38 PM Actually a lot cheaper 02-Dec-19 12:38 PM But I don't see any right now for a good deal 02-Dec-19 12:38 PM Considering that you can pick up a presumed working RGA for as low as $150, it's some perspective 02-Dec-19 12:39 PM Yeah 02-Dec-19 12:39 PM Just a different level of tool is all 02-Dec-19 12:39 PM The being able to work from atmosphere thing is pretty great 02-Dec-19 12:39 PM But I've solved a lot of leaks with RGAs 02-Dec-19 12:39 PM They work really well 02-Dec-19 12:40 PM can they really sniff helium out from atmosphere at the input? 02-Dec-19 12:40 PM Yeah 02-Dec-19 12:40 PM You throttle it down externally but yeah 02-Dec-19 12:40 PM Yha transflow setup is like a helium amplifier almost 02-Dec-19 12:41 PM helium leak amplifier 02-Dec-19 12:41 PM not to be confused with drill bits 02-Dec-19 12:41 PM Really does improve sensitiveity ratio performance 02-Dec-19 12:41 PM Lol 02-Dec-19 12:41 PM But if you're trying to fix a leak keeping you in the -5 when you should be at -7 02-Dec-19 12:41 PM Rga is awesome 02-Dec-19 12:41 PM Even a bit lower if you can make filaments cheap 02-Dec-19 12:44 PM I wonder how feasible it is to use regular tiny incandescent bulbs as filaments 02-Dec-19 12:44 PM I'm sure some manufacturer in China wouldn't mind selling you a thousand stems with tungsten attached, but no bulb 02-Dec-19 12:44 PM I don't think it's quite the right dimensions 02-Dec-19 12:45 PM and probably too high power 02-Dec-19 12:45 PM But just grabbing tungsten wire and making them isn't hard 02-Dec-19 12:45 PM As I've learned, tungsten wire oxidizes a lot 02-Dec-19 12:46 PM For the rga I have at least 02-Dec-19 12:46 PM Which speaking of I need to setup soon 02-Dec-19 12:46 PM It's this tiny little thing 02-Dec-19 12:46 PM Old balzers unit 02-Dec-19 12:46 PM The quadruple is like 3 inches long 02-Dec-19 12:48 PM For very light gases? 02-Dec-19 12:48 PM I don't even think it goes to 100 amu 02-Dec-19 12:48 PM Yeah 02-Dec-19 12:48 PM I want a 200 amu electron multiplyer one 02-Dec-19 12:48 PM Those are nice 02-Dec-19 12:49 PM crack a PMT open and bolt it on 02-Dec-19 12:49 PM Also earlier I completely understated the utility of the plot of partial pressure of compounds in vacuum 02-Dec-19 12:49 PM For anything past -6 it can be super useful 02-Dec-19 12:49 PM Not 100% necessary by any stretch of the imagination 02-Dec-19 12:49 PM But crazy useful 02-Dec-19 12:49 PM Hm 02-Dec-19 12:51 PM Then your RGA registers a bunch of carbon 02-Dec-19 12:51 PM It can 02-Dec-19 12:51 PM Or water vapor 02-Dec-19 12:51 PM Or excessive argon 02-Dec-19 12:51 PM Or other contamination 02-Dec-19 12:51 PM When your RGA tells you you need to clean your chamber, you need to clean your chamber 02-Dec-19 12:52 PM Yeah or it shows you something else 02-Dec-19 12:52 PM Like that you have a virtual leak 02-Dec-19 12:52 PM What phase of bake out you are in 02-Dec-19 12:52 PM If youre remaining gasload is outgassing or a leak 02-Dec-19 12:52 PM If you are going to struggle to get to based pressure after a bake out 02-Dec-19 12:52 PM If you're ion pumps are starting to saturate 02-Dec-19 12:52 PM If you have a excessive water load due to pourous metetrial 02-Dec-19 12:52 PM A lot more than just hydrocarbon 02-Dec-19 12:55 PM A very useful tool to have 02-Dec-19 12:55 PM I'll get one at some point 02-Dec-19 12:55 PM If you're at high vacuum trying to go further 02-Dec-19 12:55 PM If you're just going to -6 it's kinda eh 02-Dec-19 12:56 PM I still haven't pumped down the chamber I've built 02-Dec-19 12:57 PM Oh yeah focus on more useful stuff then 02-Dec-19 12:58 PM Makes sense for me to build a proper vacuum gauge reader/controller now that I have four completely different gauges 02-Dec-19 12:58 PM The full range hopefully 02-Dec-19 12:58 PM ? 02-Dec-19 12:59 PM A thermocouple, a Pfeiffer PPT-100(Pirani), the MKS-901p(MicroPirani + Piezo), and the Hornet IGM-400 02-Dec-19 12:59 PM So from atmospheric to UHV 02-Dec-19 12:59 PM That should work nicely 02-Dec-19 12:59 PM My prefered combo is either pirani and penning or convectron and penning 02-Dec-19 12:59 PM Penning just does not burn like hot anything 02-Dec-19 01:01 PM I hunted for cheap deals and I couldn't find a cheap penning 02-Dec-19 01:01 PM Yeah 02-Dec-19 01:01 PM Not surprising 02-Dec-19 01:01 PM They are out there 02-Dec-19 01:01 PM But penning ware out over years 02-Dec-19 01:01 PM So more consumable 02-Dec-19 01:02 PM "Years" is not often in the expected lifetime of my projects 02-Dec-19 01:02 PM Closer to "hours" 02-Dec-19 01:03 PM Ye they are aware for this sort of thing 02-Dec-19 01:03 PM Just finding them surplus is a bit harder 02-Dec-19 01:03 PM Often dead ones are just dirty though 02-Dec-19 01:04 PM dump some oxygen in them and ignite? 02-Dec-19 01:04 PM And by dirty I mean caked on semiconductor process mistery compound 02-Dec-19 01:04 PM More like sand and scrape 02-Dec-19 01:05 PM It probably contains some things that end with "ane" 02-Dec-19 01:05 PM Maybe 02-Dec-19 01:05 PM The yummiest instant death stuff. 02-Dec-19 01:05 PM It's a little ion source 02-Dec-19 01:05 PM It split's whatever is in vacuum and deposits it on the walls 02-Dec-19 01:06 PM I have a quick question about TIG welding. About how much would it cost for someone to TIG weld a CF275 flange to a 1.5 inch pipe? 02-Dec-19 01:07 PM Depends on how much your welder likes you 02-Dec-19 01:07 PM Anywhere from a beer to $329.99 02-Dec-19 01:07 PM Yeah pretty much 02-Dec-19 01:07 PM Remember that it has to be welded on the inside 02-Dec-19 01:08 PM Has to is a bit strong 02-Dec-19 01:08 PM Should 02-Dec-19 01:08 PM Yeah 02-Dec-19 01:08 PM Has to... 02-Dec-19 01:08 PM You can get away with a bit... 02-Dec-19 01:08 PM Highly recommend 02-Dec-19 01:08 PM For flanges it's about as easy to do the inside as outside 02-Dec-19 01:08 PM Oof, any tips for what I can do to get a better deal? 02-Dec-19 01:09 PM Shop around? 02-Dec-19 01:09 PM Us based or? 02-Dec-19 01:09 PM Befriend the welder and ask for quotes from various places 02-Dec-19 01:10 PM I'm from New England, are there any good local places that I should keep my eye out for? 02-Dec-19 01:10 PM Yeah there's one up there 02-Dec-19 01:10 PM Can't remember the name 02-Dec-19 01:10 PM I normally use the uw physics instrumentation shop or Thermionics north west 02-Dec-19 01:10 PM But those are both Washington based 02-Dec-19 01:12 PM Ah, I'll check those guys out anyways. It's fairly light, so I could imagine shipping being that bad 02-Dec-19 01:12 PM What's it for? 02-Dec-19 01:12 PM Both of those are probably at least 150 02-Dec-19 01:12 PM Minimum 02-Dec-19 01:14 PM I was planning to use it for connecting a CF275 flange to a pipe, however if it's that much I may as well just go with the pre-welded half nipple 02-Dec-19 01:14 PM Yeah 02-Dec-19 01:14 PM Unless you have a friend who is awesome at tig 02-Dec-19 01:16 PM Cool, thanks for the advice 02-Dec-19 01:16 PM Sorry there isn't something better we could offer 02-Dec-19 01:16 PM I want to get a Tig but need more shop space first... 02-Dec-19 01:17 PM @GigaSquirrel is making tig on SS look super easy 02-Dec-19 01:17 PM Its at-least not Aluminum I guess which is apparently 10 times harder 02-Dec-19 01:17 PM if you can SMD solder you can TIG SS 02-Dec-19 01:18 PM I can freehand .4mm pitch recessed pin QFN 02-Dec-19 01:18 PM does this mean I can wire bond by vibrating my hand a little 02-Dec-19 01:18 PM TIG on Al vs TIG on SS is like soldering tht vs soldering smd 02-Dec-19 01:19 PM SMD isn't hard though really... that feels like a bad analogy 02-Dec-19 01:19 PM Al isn't that hard either 02-Dec-19 01:19 PM Welding vs a weld that's good to the -11s? 02-Dec-19 01:20 PM yeah never tried that 02-Dec-19 01:20 PM What I heard from professional vacuum welders was that even perfect looking welds often needed rework to hit those levels 02-Dec-19 01:20 PM And that everything was vanurable to micro cracks 02-Dec-19 01:22 PM can't say anything about that, but it sounds reasonable 02-Dec-19 01:22 PM all I know is that welding for e-6 is easy 02-Dec-19 01:23 PM Good to know 02-Dec-19 01:23 PM I guess that's what 5 orders of magnitude does lol 02-Dec-19 01:25 PM yep 02-Dec-19 01:25 PM Have you taken your system to-7? 02-Dec-19 01:26 PM nope, haven't even baked the "new" chamber yet 02-Dec-19 01:26 PM Or done a leak rate after several days of pumping? 02-Dec-19 01:26 PM "new" 02-Dec-19 01:26 PM I like it 02-Dec-19 01:26 PM Cut some holes in something, melt a bit of it to other stuff and now it's new 02-Dec-19 01:28 PM haven't even baked the old chamber after working on it yet 02-Dec-19 01:28 PM happy? 02-Dec-19 01:29 PM Lol I'm fine calling it new 02-Dec-19 01:29 PM Just think it's funny 02-Dec-19 01:29 PM New configuration right? 02-Dec-19 01:29 PM welded some ports onto it and new config 02-Dec-19 01:29 PM New arrangement of atoms? 02-Dec-19 01:29 PM New metelurgical properties surrounding the welds 02-Dec-19 01:30 PM and new atoms introduced! 02-Dec-19 01:30 PM See 02-Dec-19 01:30 PM Definitely new 02-Dec-19 01:30 PM Heck 02-Dec-19 01:30 PM Even new atoms exposed! 02-Dec-19 01:31 PM hell yeah! 02-Dec-19 01:32 PM Speaking of new atoms I can't wait until I can afford to introduce a few bajillion atoms of steel building into the back yard for a massive workshop/storage area 02-Dec-19 01:32 PM I may try to re-finance the house at a higher value next year just to swing it, once I have that I'll be a lot happier and be way better off with working on things. 02-Dec-19 01:34 PM Ok Conner we expect an accurate accounting of each atom in the new building 02-Dec-19 04:15 PM have what is possibly a stupid question. in my diffusion pump if there is a little peg that is the right size for a notch in the bottom of the stack to register on i am assuming that is the correct orientation for everything to sit in...right? 02-Dec-19 04:37 PM yes, but diffpumps are pretty symmetrical in cross section afaik 02-Dec-19 06:13 PM just was wondering because the ejector stage on mine, when the notch and peg are aligned, points off at an angle from the exhaust arm 02-Dec-19 06:13 PM seems like a sort of arbitrary angle too but i cannot imagine any other reason for the notch 02-Dec-19 09:53 PM Its possible that not an alignment notch. there needs to be some way for the oil to flow to the inner stages of the jet stack 02-Dec-19 09:53 PM But the peg makes it sound like alignment... Does your pump have outflow baffles? 02-Dec-19 10:33 PM it has a baffle that goes inside the exhaust 02-Dec-19 10:33 PM aside from the notch there are thinner slots that I think are for the oil to flow... 02-Dec-19 10:33 PM https://i.gyazo.com/4dcb50cdf25b60c98f1dfed4a1d48bef.png 02-Dec-19 10:48 PM Joined the server. 02-Dec-19 10:48 PM Welcome! 03-Dec-19 02:52 AM Welcome! 03-Dec-19 04:44 AM Joined the server. 03-Dec-19 04:44 AM quite a few familiar faces from the reps and/or odrive channels 03-Dec-19 05:07 AM heyo! 03-Dec-19 05:21 AM Ahoy! 03-Dec-19 05:48 AM faces yeah. 03-Dec-19 05:48 AM XDDDD 03-Dec-19 06:01 AM hehe 03-Dec-19 06:01 AM internet faces in the internet places 03-Dec-19 06:08 AM /insert reps-safe joke with the word faces/ 04-Dec-19 12:51 AM atoms 04-Dec-19 12:10 PM Finally ordered my replacement scintillator for the SEM! I've been meaning to for like a month now :O 04-Dec-19 12:10 PM At least all that's needed before more debugging ensues 04-Dec-19 12:37 PM heh... 04-Dec-19 12:37 PM Trust me we all have parts we've been meaning to buy for months hehe 04-Dec-19 05:57 PM Joined the server. 04-Dec-19 06:05 PM Welcome o/ 04-Dec-19 06:56 PM @digshadow yo yo yo 04-Dec-19 11:53 PM so much parts 04-Dec-19 11:58 PM @N00N you can't say something like that without posting pictures 04-Dec-19 11:58 PM has your christmas time started yet? 05-Dec-19 12:12 AM no I mean it related to @Conmega s message 05-Dec-19 01:27 AM ok, ok :< 05-Dec-19 01:33 AM T_T 05-Dec-19 07:31 PM So normal high pressure valves should work well for not-high vacuum gas metering/control, right? 05-Dec-19 07:31 PM If it's rated to stop 100psi, why wouldn't it stop atmospheric?? 05-Dec-19 07:31 PM Is it just that it would be leaking enough that you'd never reach high vacuum? 05-Dec-19 07:31 PM (I'm working on a molecular vapor deposition setup, where it's only gonna be at like 1 ot 0.1 torr) 05-Dec-19 07:31 PM It's just super annoying to me that the cheapish vacuum valves on ebay are pneumatically controlled. Like, I have some pneumatic solenoid control valves, but it just really annoys me that I'd need to string air tubes across the lab 05-Dec-19 07:51 PM it's rated to stop 100 psi, but it will still leak 05-Dec-19 07:51 PM I'm building a little air station for my vacuum valves, tiny car compressor, power supply, welded square tube buffer tank 05-Dec-19 07:51 PM they don't take much volume and they don't constantly leak 06-Dec-19 05:57 AM the problem with leaks is that it will introduce oxigen and other gases in your system, wich might frick up your chemical processes. 06-Dec-19 01:50 PM Well bought two vacuum valves, just in case. We're using a PVC pipe for the vacuum chamber and cutting the end was done with a table saw, rotating the pipe around, causing some discontinuities in the cut edge. Trying to use a few hot plates with a 1 inch thick plate, with the pipe resting on that, to melt the end into flatness 06-Dec-19 01:50 PM The thinking to use a silicone gasket, or make one with silicone ourselves... So that seems bound to possibly produce leaks, probably more than a gas high pressure valve would 06-Dec-19 01:52 PM PVC vacuum chamber!? 06-Dec-19 01:52 PM It's going to outgas like hell 06-Dec-19 02:05 PM yeah, that is not going to work... 06-Dec-19 02:27 PM depends what kind of "vacuum" is the goal? 06-Dec-19 02:27 PM what are you guys planning to do @nmz787 ? 06-Dec-19 02:31 PM Molecular vapir deposition of FDTS (anti adhesion layer) 06-Dec-19 02:34 PM not something i know enough about to give input on but what ultimate pressures do you need? maybe other people can tell you if that is way too far for the PVC or not 06-Dec-19 02:45 PM Like 1 or .1 torr 06-Dec-19 05:58 PM if you manage to hit 1 torr i will be surprised 06-Dec-19 05:58 PM depending on your pump speed and the length/diameter of the pipe 06-Dec-19 05:58 PM but, hey, by all means give it a shot 06-Dec-19 05:58 PM if you really want to make it work you could probably coat the majority of the inside in some low-outgassing sealant and that might help matters 06-Dec-19 05:58 PM definitely consider a different formulation of pipe if it has a 'smell' to it 06-Dec-19 10:32 PM 1 torr was pretty easy to hit with the salad bowl we tried as a bell jar, happened pretty much within 30 seconds 06-Dec-19 10:32 PM Unless i messed up my math and conversion from the gauge's reading of -97 kPa 06-Dec-19 10:32 PM I can't imagine how offgassing would significantly affect such a feat 06-Dec-19 10:32 PM The tube is 10" across, and something like 30" long 06-Dec-19 10:32 PM Figure it will take a bit longer, but as long as the ends are sealed up, seems like it wouldn't leak so much to disallow what we already saw with the crappy sheet of silicone gasket over a plate with a salad bowl on top 06-Dec-19 10:32 PM Melting the PVC ended up not working out too well IMO, I guess the temperature overshot on the hotplates and the bottom started bubbling and turning to some brown hard thermal insulator 07-Dec-19 06:47 PM met @Noxz and visited with him this afternoon. I've met 4 people from this discord in person now! 07-Dec-19 06:48 PM how long was the drive back? less traffic? 07-Dec-19 06:49 PM Not too bad by Seattle standards, only about 45 minutes. 08-Dec-19 12:18 AM yay! 08-Dec-19 12:18 AM gotta catch them all @piGuy 09-Dec-19 02:56 PM Is there a cheap way to get into cryocoolers? 09-Dec-19 03:15 PM No :( 09-Dec-19 03:15 PM Look for a cryocompressor and cold head/cryopump 09-Dec-19 03:15 PM You might find a deal 09-Dec-19 03:15 PM eBay search terms are "cryopump", "cti cryogenics", "helium compressor", "polycold", "cryotiger" 09-Dec-19 03:48 PM Yeah I’ve searched before and I can’t find the amazing deals like “I found this perfect cryocooler on eBay for $75” 09-Dec-19 04:20 PM there were a few that have popped up in the last 5yrs or so but they were closer to $500-$1000 and kinda iffy 09-Dec-19 04:20 PM there were a few of the crycooled cellular infrastructure pieces that showed up too for $200-$800 09-Dec-19 04:20 PM i bought one of those for $250 and then the guy said he couldnt find it which i took to mean that he realized it was worth way more 09-Dec-19 05:13 PM I'm going to assume that's the same guy selling it now for $2500 09-Dec-19 05:13 PM lol 09-Dec-19 05:13 PM @piGuy https://www.ebay.com/itm/Oxford-Instruments-M600/202706622184 09-Dec-19 05:15 PM Listing says $200 09-Dec-19 05:15 PM yes, that's cheap 09-Dec-19 05:15 PM then you hook it up to something like this 09-Dec-19 05:15 PM https://www.ebay.com/itm/CTI-CRYOGENICS-ON-BOARD-P300-CRYOPUMP-0190-27350R-SOLD-AS-IS/182392835241 09-Dec-19 05:15 PM using a pair of these 09-Dec-19 05:15 PM https://www.ebay.com/itm/Pressurized-50-Cryogenic-Helium-Pump-Hose-1-2-ID-Cryo/143355042010 09-Dec-19 05:15 PM in this case you also get a RIDICULOUSLY fast high vacuum pump 09-Dec-19 05:15 PM https://i.spirit.re/bMoYT.png 09-Dec-19 05:15 PM the largest pumps(think ISO300ish) go above 15-20 000 l/s for water 09-Dec-19 05:20 PM Hmm, that first item is like 35 mins from me 09-Dec-19 05:20 PM the compressor is only the compressor 09-Dec-19 05:20 PM you need a cold head and hoses to start it up 09-Dec-19 05:20 PM oh, and you'll need an ultra high purity helium refill 09-Dec-19 05:20 PM but for these sizes it's not too expensive afaik, even here it's only $20-40ish 09-Dec-19 05:23 PM And that'd be used for.... Cooling diffusion pump baffles? Or cooling any gas and using this as a vacuum pump? 09-Dec-19 05:23 PM Cooling my beer? 09-Dec-19 05:23 PM the cryopumps are literally just cold heads that liquefy and/or freeze all the gases in your vacuum chamber 09-Dec-19 05:23 PM it's a high vacuum pump category, next to diffpumps and turbos 09-Dec-19 05:23 PM but they're very fast, very clean(literally no moving parts or liquids in the vacuum chamber), they don't care about venting(UHV to atmosphere in seconds) 09-Dec-19 05:23 PM downside is that they're large and expensive 09-Dec-19 05:23 PM since you need a helium compressor running continuously and hoses going to it 09-Dec-19 05:23 PM another downside is that the pumping speeds and capabilities are very varied(see picture above) 09-Dec-19 05:23 PM that, and since they run on liquid helium, it... well, it can't pump helium or gases that liquefy/freeze below ~LN2 temps, lol 09-Dec-19 05:23 PM @GigaSquirrel and @Conmega have hands-on experience with these and can tell you more about it 09-Dec-19 09:28 PM @Deleted User I think he ended up selling it for around $1800 or something haha 09-Dec-19 09:28 PM was one of the STI Superlink things 09-Dec-19 09:33 PM yeah the superlinks got a ridiculous hike in price when one was shown in a veritasium video 09-Dec-19 09:33 PM cooky ebay sellers 09-Dec-19 09:33 PM all the telco resellers ones got snapped up in HOURS 09-Dec-19 09:33 PM a good 50 units went 09-Dec-19 09:36 PM this was before they were cool even! like 2010ish 09-Dec-19 09:37 PM 2010ish was when Ben made a blog post about them :P 09-Dec-19 09:38 PM i think this was actually before his stuff went up but it was long enough ago that im not really sure 09-Dec-19 09:38 PM it was the blog, not the video 09-Dec-19 09:38 PM what this stuff did remind me of from a few years ago was a really cool video i saw https://www.youtube.com/watch?v=GFfMruoRMGo 09-Dec-19 09:38 PM would love to have one of those cute little things to make liquid air...and that boat engine? adorable 09-Dec-19 09:40 PM you can make liquid air in small amounts by butchering an old Agema thermal camera 09-Dec-19 09:40 PM but that's a bit of an evil thing to do in the hobby world 09-Dec-19 09:40 PM but even the hybrid98 cryocoolers inside the amplinks and other sti cryogenics devices are very low power 09-Dec-19 09:40 PM the thermal camera cryocoolers are 1/10th of that, so you'll maybe make 50-100ml of liquid air in 24 hours 09-Dec-19 09:40 PM but the cryopump/compressor combos are very powerful, maybe 10x the rating of the hybrid98 coolers 09-Dec-19 09:40 PM enough to make several liters per day 09-Dec-19 09:45 PM i wonder what sort of tolerances are needed in that motor driven stirling thing 09-Dec-19 09:45 PM mirror polish on the business surfaces 09-Dec-19 09:45 PM except not polished, but diamond machined :P 09-Dec-19 09:45 PM perhaps ground? 09-Dec-19 09:45 PM the powerful ones, are a bit more crude, someone here made their own cryo regenerator(business end, not the compressor) IIRC 09-Dec-19 09:45 PM but the helium compressors are pretty much just slightly better fridge compressors, including constructions 09-Dec-19 10:24 PM Sorry if this has already been mentioned. Hackaday chat with @Applied_Ion Dec 11.... https://hackaday.com/2019/12/09/open-source-satellite-propulsion-hack-chat/ 10-Dec-19 12:23 AM also a note re: cryopumps on vacuum systems: be careful and have an overpressure burst valve or somesuch somewhere on your system, because when you warm it up everything it 'pumped' is going to turn back to gas in your chamber 10-Dec-19 12:23 AM so if you pumped anything nasty it's all gonna come right back 10-Dec-19 12:23 AM and if you had a leak somewhere in your chamber you may have frozen in enough gas to now exceed ambient pressure on warming 10-Dec-19 12:23 AM i am told viewports don't like that sort of thing 10-Dec-19 12:39 AM just drop one of the KF clamps once the system is under vacuum 10-Dec-19 12:39 AM if it overpressures something will fly off 10-Dec-19 11:39 AM Joined the server. 10-Dec-19 12:31 PM Joined the server. 10-Dec-19 12:32 PM Seems like the server got linked somewhere? 10-Dec-19 12:33 PM Joined the server. 10-Dec-19 12:34 PM It definitely did get linked somewhere. That's a name I recognize! :) 10-Dec-19 12:36 PM Hey to everyone thanks for inviting in chat @GigaSquirrel 10-Dec-19 12:40 PM Welcome o/ 10-Dec-19 12:47 PM I know where it got linked 10-Dec-19 12:47 PM wait @ZeptoBars you weren't here already?! 10-Dec-19 12:47 PM damn, was about time 10-Dec-19 12:49 PM Hi there, joined as I am building first HV system for experiments with semiconductor manufacturing technology... So far forevacuum is at 0.5Pa, waiting for ISO100 fittings and such... 10-Dec-19 12:49 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-C9F63.png 10-Dec-19 12:50 PM @ZeptoBars if you need a supplier of vacuum stuff in Moscow, I know a guy I bought stuff from 10-Dec-19 12:50 PM We talked about soviet x-ray tubes via email a while ago 10-Dec-19 12:52 PM He-he, world is small 10-Dec-19 12:52 PM indeed 10-Dec-19 12:53 PM I have questions about mks901p vacuum Sensor . What is best voltage for transducer I thinke 9v0.6 Adapter is okay ? Or 12v1amp adaptor. 10-Dec-19 12:53 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-C208A.jpg 10-Dec-19 12:53 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image1-543A3.jpg 10-Dec-19 12:53 PM https://www.mksinst.com/mam/celum/celum_assets/resources/HPS901man-REVI.pdf 10-Dec-19 12:53 PM Here's the datasheet 10-Dec-19 12:53 PM Looks like it only consumes 1.2W at anywhere from 9 to 30VDC 10-Dec-19 12:53 PM so I'd go for 12V just to be safe and power efficient 10-Dec-19 12:53 PM 12V @ 200mA should be more than sufficient for it, since that's the fuse current limit 10-Dec-19 12:57 PM I have one 12v1amp adapter it could be safe for transducer? @Deleted User 10-Dec-19 12:57 PM yep 10-Dec-19 12:57 PM just make sure it's connected the right way around 10-Dec-19 12:58 PM I was planning to use 12v since the bipolar (+/-15V) for my mass flow controller can take 12 in 10-Dec-19 12:58 PM Bought some VGA cables to cut apart 10-Dec-19 12:58 PM One had a missing pin, but it's attached to a relay control which I'm not going to use 10-Dec-19 12:59 PM I will make some interface just soldering not cutting 10-Dec-19 12:59 PM using serial is the best option, since the "analog" outputs are driven by a DAC 10-Dec-19 01:00 PM @ahmadalinia VGA cable was $3, 15 pin high density connector was $1... Figured I'd have to do 1/2 as much soldering just cutting a cable 10-Dec-19 01:01 PM I recommend using VGA cables, since they have a nice connector and ferrite suppression built right in 10-Dec-19 01:01 PM And shielding, lots of shielding 10-Dec-19 01:01 PM not to mention pretty much everyone has a spare VGA cable somewhere :P 10-Dec-19 01:01 PM I was surprised 10-Dec-19 01:02 PM @nmz787 I want to some job not massy but job also good and acceptable 10-Dec-19 01:04 PM A cut VGA cable looks quite professional, vs starting with bare wire and a solder-cup connector. To get it looking nice I guess you'd need at least a fair amount of heatshrink tubing. 10-Dec-19 01:04 PM I mean this one as interface 10-Dec-19 01:04 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-68672.jpg 10-Dec-19 01:04 PM Jus I must be careful about PIN number 10-Dec-19 01:06 PM Easy enough with an ohmmeter 10-Dec-19 01:06 PM Of course 10-Dec-19 01:07 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191211_000723-E98F8.jpg 10-Dec-19 01:07 PM It's a popular device :P 10-Dec-19 01:09 PM I have 1 and just ordered 2 more last week 10-Dec-19 01:09 PM Ebay said they're brand new 10-Dec-19 01:09 PM From an apple fab that didn't go into production 10-Dec-19 01:09 PM Spent way too long reading about welders last night, thinking of how to connect all this stuff 10-Dec-19 01:10 PM I'm tempted to order more than one but I already have 4 gauges now, two of which are pirani 10-Dec-19 01:10 PM Yeah, these 901P will be everywhere. I've seen lots where they show hundreds of these. 10-Dec-19 01:11 PM For good reason 10-Dec-19 01:11 PM MKS nailed their design on this one 10-Dec-19 01:11 PM Tiny, cheap, more accurate than just piezo or just pirani 10-Dec-19 01:11 PM Speaking of which, @ZeptoBars you might want to pull one apart for the IC blog 10-Dec-19 01:11 PM They're actually vacuum gauges on a chip! 10-Dec-19 01:11 PM More reliable - that's the main factor. No place for human error to turn on heating too soon. 10-Dec-19 01:11 PM On two chips 10-Dec-19 01:11 PM There's a pirani microassembly, and a piezo chip-ish thingy 10-Dec-19 01:11 PM You can see one of them if you look through the flange 10-Dec-19 01:12 PM Yeah, that could be interesting, but as it is more of a mems, it might really benefit from SEM... Definitely will take a look 10-Dec-19 01:12 PM @Deleted User it’s like Toyota Corolla in every where 10-Dec-19 01:12 PM They're not SEM-scale 10-Dec-19 01:12 PM You can easily see the working innards with the naked eye 10-Dec-19 01:12 PM @ahmadalinia lol 10-Dec-19 01:13 PM Yeah, but they will be very 3D which does not look very good in optical microscope... We'll see anyways 10-Dec-19 01:13 PM Focus stacking! 10-Dec-19 01:13 PM You've done that 10-Dec-19 01:13 PM the only downside is that as far as I know they're welded shut 10-Dec-19 04:13 PM I am designing a controller around that gauge @ahmadalinia but it does just talk RS-232. And you can just interface it with a PC and a power source. 10-Dec-19 04:13 PM Let me see if I have some photos of the controller I am making 10-Dec-19 04:15 PM @Conmega by controller do you mean a program? 10-Dec-19 04:15 PM No a board with a display and button interface for different graph modes and such. 10-Dec-19 04:15 PM Ah, I'm just using a raspi 10-Dec-19 04:16 PM It will also have an ADC for Pfeiffer's activeline gauges which is a cheap source for could cathode gauges ATM so with an activeline cold cathode and that MKS you get a full range vacuum gauge solution in one controller. 10-Dec-19 04:16 PM And they are cheap and readily available on ePay 10-Dec-19 04:16 PM Here are what those look like 10-Dec-19 04:16 PM https://photos.app.goo.gl/eUEbyyJrZtGdH8tZA 10-Dec-19 04:17 PM a 0-10V ADC with some reverse LUTS in firmware and you can read pretty much every gauge out there 10-Dec-19 04:17 PM besides raw thermocouples 10-Dec-19 04:17 PM and funnily enough, MKS provide a complete set of 0-10V scales in their 901P datasheet! 10-Dec-19 04:17 PM https://www.mksinst.com/mam/celum/celum_assets/resources/HPS901man-REVI.pdf 10-Dec-19 04:17 PM pages 23 through 45 show you every kind of output from all kinds of manufacturers 10-Dec-19 04:17 PM and you can even use the 901p to calibrate all the readings, since the RS232 interface lets you select which output you want the 901p to behave as 10-Dec-19 04:20 PM Yes they do. But I will specifically be setting this up for all of Pfeiffer's activelines because they have identification resistors I am using with a resistor divider and a simple ADC in the micro I am using to identify and properly graph them and such. 10-Dec-19 04:20 PM Here is the board without through hole stuff yet 10-Dec-19 04:20 PM https://photos.app.goo.gl/LyxVqjWY7F1a9vcZ8 10-Dec-19 04:20 PM Firmware will be upgradable via USB/Serial interface 10-Dec-19 04:21 PM I see a distinct lack of ground planes 10-Dec-19 04:21 PM but the layout looks nice 10-Dec-19 04:21 PM grould flooded on the back 10-Dec-19 04:21 PM and I ground flooded around specific areas 10-Dec-19 04:21 PM then stitched through to the back 10-Dec-19 04:21 PM should be on the front too, you don't want capacitive funny business 10-Dec-19 04:21 PM stitching is always good 10-Dec-19 04:22 PM Especially around those relay traces 10-Dec-19 04:22 PM eh true, I may do one more run of the board anyway, this was just the second revision adding the ADC 10-Dec-19 04:22 PM fair enough, thanks for the feedback. 10-Dec-19 04:22 PM I will definitely add ground flooding to the front when I open that back up again. 10-Dec-19 04:22 PM Its mostly I just need to get back to firmware development and actually get a vacuum chamber that can pull down low enough to test a darn cold cathode gauge >:( 10-Dec-19 04:22 PM I could hook it up to my SEM I suppose 10-Dec-19 04:28 PM on the vacuum hardware note 10-Dec-19 04:28 PM https://i.spirit.re/DjPnh.png 10-Dec-19 04:28 PM I'm working on it, I swear™ 10-Dec-19 04:33 PM Nice 10-Dec-19 04:33 PM I've learned a bunch about motor control from this AC servo project, which I'm still writing firmware for 10-Dec-19 04:33 PM But I feel like I have to design the turbo controller now, send it off to manufacture(which will take 3-4 weeks to arrive), and keep working on the AC servo 10-Dec-19 04:35 PM hehehe 10-Dec-19 04:35 PM I should set I'm working on it, I swear™️ as my status lmao 10-Dec-19 04:37 PM I'm going to use a powerful and quite recent STM32G474 for the turbo controller 10-Dec-19 04:37 PM 170MHz, FPU, all the good stuff 10-Dec-19 04:37 PM That way I won't have to cry as I cram fixed point PID controllers into it, like I am doing right now with the servo 10-Dec-19 04:37 PM Total overkill? Maybe. 10-Dec-19 04:39 PM Could also look into TI's C2000 Delphino chips 10-Dec-19 04:39 PM Time has value, so does coder sanity. 10-Dec-19 04:39 PM I'm sticking with STM32 because I've already sanded my brain with it sufficiently to understand the basic operation 10-Dec-19 04:39 PM They are really nice, and just remember clock speed isn't everything and ram access time is a BIG thing, a LOT of STM32s can't touch ram but every few instruction cycles which slows them down a lot... 10-Dec-19 04:39 PM Fair enough, just remember to read the datasheet and family documention closely! 10-Dec-19 04:40 PM Trust me, you don't need 170MHz to run a turbo controller 10-Dec-19 04:40 PM Oh no I know 10-Dec-19 04:40 PM Which means you have 170MHz to do things very inefficiently! 10-Dec-19 04:40 PM :D 10-Dec-19 04:40 PM I have seen 8085s running them I think haha 10-Dec-19 04:40 PM Funnily enough I am building exactly the same sort of thing right now. Pfeiffer cold cathode inverted magnetron, 0-10V output. 18V into the board, passed through to the gauge and also regulated to 5V for the MCU, LCD display, ATmega328P, simple 1:2 voltage divider on the analog input, simple maths to get the pressure, it’s basically just 10^-V torr on most 0-10V ion gauges 10-Dec-19 04:40 PM cool! 10-Dec-19 04:40 PM I'll be building a vacuum controller at some point 10-Dec-19 04:40 PM Universal input modules, pressure level sequencing with relays/rs232/rs485 10-Dec-19 04:40 PM But that's a project after a project after a project and I don't plan things out that far 10-Dec-19 04:42 PM Nice. Automatic turbo interlock until rough vacuum is reached, and high vacuum interlock for sensitive devices like channeltrons and MCPs are really nice features to have 10-Dec-19 04:42 PM Not sure if I'll stick with STM32 for that or just plop a tiny linux brain into it 10-Dec-19 04:42 PM Seems like it could benefit from a high level scripting language 10-Dec-19 04:43 PM Yea, ours at former employer was Python. 10-Dec-19 04:43 PM With C for the embedded controller talking to the embedded PC 10-Dec-19 04:53 PM For the turbo driver maybe a cheap hobby king 3ph brushless motor driver is good 10-Dec-19 04:57 PM Definitely not good 10-Dec-19 04:57 PM Too much back-EMF, too little voltage, very different topologies(unless it's an actual 3ph motor) 10-Dec-19 04:57 PM Should be ok for driving turbodrag pumps though 10-Dec-19 05:21 PM Pft just turn the turbo and rotary on at the same time 10-Dec-19 05:21 PM It I'll probably pump fast enough 10-Dec-19 05:21 PM I was at a university lab working on a system and a student was building a new vacuum setup and the student asked the pi if you have to wait for the rotary to pump it down before turning the turbo on. He says yeah you do while at the same time simultaneously turning both on 10-Dec-19 05:29 PM Lol 10-Dec-19 06:40 PM Joined the server. 10-Dec-19 07:12 PM Quick question for turbo owners - an input voltage range of, say, 20-70V should be fine, right? 10-Dec-19 07:39 PM Into the controller or into the pump itself? 10-Dec-19 07:59 PM into the controller, but that doesn't matter since all pumps are current driven 10-Dec-19 07:59 PM I'm just wondering if there are pumps that need over 70V 10-Dec-19 08:21 PM All the ones I have seen take 24V DC into the factory driver, or 230V or 115V AC from the grid 10-Dec-19 08:53 PM if you are doing the 3 phase kind of turbo controllers just make sure that you do not get one of the old pfeiffer turbos with 4 coils 10-Dec-19 08:57 PM Mine Edwards EXT 255H requires 80V, and controller will abort if voltage drops below some 75V. Newer controllers though are 24V 10-Dec-19 09:25 PM I'm building a universal turbo controller 10-Dec-19 09:25 PM The first version will be 2/4 phase, since my pfeiffer turbo is 4-phase 10-Dec-19 09:25 PM But then I'll probably make an addon or second version for 3ph turbos 10-Dec-19 11:13 PM good morning everyone! 10-Dec-19 11:13 PM and welcome to all the newbies :) 10-Dec-19 11:29 PM hmm i think i identified the issue with one of my D2.5Es 10-Dec-19 11:29 PM bubbles around the sight glass are probably a bad thing 10-Dec-19 11:31 PM Bubbles in the oil? 10-Dec-19 11:34 PM yes but also bubbling that seems to be right at the edge of the sight glass 10-Dec-19 11:35 PM I'm not sure I understand 10-Dec-19 11:35 PM bubbeling inside of the pump or outside (leaking)? 10-Dec-19 11:38 PM https://www.youtube.com/watch?v=iV6nwtd39xk 10-Dec-19 11:38 PM easier to just link that 10-Dec-19 11:42 PM yep, thanks 10-Dec-19 11:42 PM looks like bubbles in the oil being flushed around 10-Dec-19 11:42 PM not an issue 10-Dec-19 11:43 PM on the left it seemed like blow by to me but i hope your suggestion is all it is 10-Dec-19 11:44 PM whats the Problem with your pumps? 10-Dec-19 11:44 PM Quick off-topic interjection: 5A is a good upper current limit for pretty much all turbos, right? 10-Dec-19 11:45 PM nothing major just one doesn't get down as far as fast as the other so i was trying to figure out why 10-Dec-19 11:45 PM that is what the old pfeiffer ones are current limited at but those are all i know about 10-Dec-19 11:45 PM ah nevermind, found a better current sensor 10-Dec-19 11:46 PM oh, that sounds like issues with some internal gaskets or even the vanes 10-Dec-19 11:46 PM maybe the ballast? 10-Dec-19 11:46 PM the gas ballast system leaking is my suspicion 10-Dec-19 11:46 PM good point 10-Dec-19 11:46 PM or that oring by the sight glass playing a part 10-Dec-19 11:47 PM yep, sounds like the gas ballast 10-Dec-19 11:47 PM unscrew the gas ballast valve and block the port with a piece of rubber 10-Dec-19 11:51 PM it could also be leaking from the other way? 11-Dec-19 12:02 AM i can't really do any more tonight but blocking off the gas ballast will be my next test because i really do not want to tear the pump apart 11-Dec-19 12:02 AM my neighbors like me and i am trying to keep it that way haha 11-Dec-19 12:03 AM huh? 11-Dec-19 12:03 AM the D2.5E should be very quiet 11-Dec-19 12:05 AM the pump is quiet but doing other things like moving a couple boxes to get the stuff needed for blocking off the gas ballast has a pretty decent chance to not be 11-Dec-19 12:05 AM they are in a bad spot and i have to get out the ladder heh 11-Dec-19 12:07 AM ah well :D 11-Dec-19 12:08 AM the D2.5Es are really nice with how quiet they are 11-Dec-19 12:12 AM oh yes 11-Dec-19 12:12 AM can have them running 24/7 in an appartment with no issue 11-Dec-19 12:12 AM my setup was a tiny air cooled oildiff with my D2.5E 11-Dec-19 12:12 AM ahhh it was whisper quiet 11-Dec-19 12:12 AM a bit too quiet at times, had to check if the fan is still alive 11-Dec-19 12:20 AM Welome @ZeptoBars ! 11-Dec-19 12:24 AM https://i.spirit.re/Li4Dw.png 11-Dec-19 12:24 AM https://i.spirit.re/yedIA.png 11-Dec-19 12:24 AM This is going to be a mess to lay out 11-Dec-19 12:24 AM and I really really don't want to go 4 layers on this big of a board 11-Dec-19 12:24 AM the STM32G474 has quite a massive set of features though - DACs, ADCs, opamps, comparators with adjustable hysteresis, and internal routing for it all! 11-Dec-19 12:24 AM I'm using the DACs to generate a trigger voltage for the negative rail of the internal comparators, the positive rail is directly connected to hall effect sensor inputs, zero external components needed! 11-Dec-19 12:24 AM (zener clamped of course) 11-Dec-19 01:23 AM Why? 11-Dec-19 01:24 AM why... which part? 11-Dec-19 01:24 AM that. 11-Dec-19 01:24 AM XD 11-Dec-19 01:24 AM Why is going to be a mess to lay out 11-Dec-19 01:24 AM doesn't look that bad to me. 11-Dec-19 01:24 AM because 2-layer power electronics are hard 11-Dec-19 01:24 AM current capacity and all that 11-Dec-19 01:25 AM good luck. 11-Dec-19 04:07 AM @Deleted User HiPace 80 is 4.6A 24V. So that’s under 5A. (Just one data point - that’s the only turbo on my desk at the moment.) 11-Dec-19 04:15 AM It's also usually limited by temperature, not current. 11-Dec-19 04:15 AM Or that's what I recall from ours. 11-Dec-19 04:15 AM Never truly hit the current limit, but if there was too much gas load it would hit thermal limits and shutdown. Even with the tiny pheiffer fan mounted and running :P 11-Dec-19 09:40 AM haha oh wow 11-Dec-19 09:40 AM at 15°C you can hear the turbo complain about cold oil 11-Dec-19 09:43 AM :D 11-Dec-19 09:43 AM I dont recall if the cutoff was 40C or 50C 11-Dec-19 09:43 AM but then it shut down due to over temperature, this being HiPace80 11-Dec-19 10:07 AM moin! 11-Dec-19 12:43 PM Hi I make interface between mks and serials port but I connect it to pc by R232 to usb but there is not any signal send . Please told my self what I must to do . 11-Dec-19 12:43 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-9676A.jpg 11-Dec-19 12:43 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image1-2B60A.jpg 11-Dec-19 12:44 PM Did you read the manual? 11-Dec-19 12:44 PM Set the right baud rate, right pins? 11-Dec-19 12:46 PM Yes I connect pin correct but i don’t why it not show anything on pc and another thing i realize about port 5and6 it’s not show any voltage by voltmeter 11-Dec-19 12:51 PM Did you check your part number? 11-Dec-19 12:51 PM It can be either rs485 or rs232 11-Dec-19 12:57 PM Part number? What is that and where is this number 11-Dec-19 12:57 PM ? 11-Dec-19 12:58 PM "P/N: 901P-mod" on your gauge's label 11-Dec-19 12:58 PM there's a few variations of the 901P 11-Dec-19 12:58 PM 901p-11040 11-Dec-19 01:00 PM 901P 1 - KF16 1 - RS232 0 - 0-9VDC analog output 4 - 3 relays, dual analog output(piezo differential) 0 - no display 11-Dec-19 01:00 PM Yes 11-Dec-19 01:00 PM It’s 11-Dec-19 01:01 PM So check your baud rate, try using the MKS Vacuum Logger software 11-Dec-19 01:01 PM make sure you don't have RX and TX swapped 11-Dec-19 01:02 PM Baud rate is 9600 11-Dec-19 01:02 PM How I could realize RX TX swapped ? 11-Dec-19 01:04 PM ... by swapping it again 11-Dec-19 01:04 PM only one of two ways it can work 11-Dec-19 01:12 PM Okay thanks 11-Dec-19 01:37 PM that is weird that you do not get any voltage on pins 5/6... 11-Dec-19 01:37 PM when you apply power does the LED light up green immediately or is it red and then goes green in about 2s? 11-Dec-19 01:37 PM ...thought the green only lights up if it passes its internal self checks but maybe those do not catch if something has blown the analog out... 11-Dec-19 02:04 PM does anyone know what kind of temperature sensor this is? 11-Dec-19 02:04 PM https://i.spirit.re/xD3Dr.png 11-Dec-19 02:04 PM the documents say nothing about what it actually is 11-Dec-19 02:04 PM looks like a thermistor? 11-Dec-19 02:05 PM it is 11-Dec-19 02:05 PM but... two in series? 11-Dec-19 02:06 PM maybe two different points of measurement 11-Dec-19 02:07 PM the turbo drive is slowly taking shape 11-Dec-19 02:07 PM https://i.spirit.re/NCwDZ.png 11-Dec-19 02:07 PM but I'm trying to figure out how to make a nice and universal temperature input 11-Dec-19 02:26 PM @LightningPhil you might want to talk to @Charles, he's the vacuum tube master here 11-Dec-19 02:29 PM I got a plink. What am I being asked about? 11-Dec-19 02:30 PM Looks like Phil is interested in sealing and evacuating triodes 11-Dec-19 02:38 PM Given his #introductions_and_directory message 11-Dec-19 02:52 PM Gotcha. @LightningPhil pretty straight forward. Roughing pump, I prefer belt drive dual seal babe pumps personally. A small diffusion pump with silicone oil, 704 preferred, 3 valves, and some form of compression port and that’s about it for the vacuum side. You will need to build a removable oven for baking out. A bench top system or something that can fit in a rolling 19” rack is pretty simple to work up. I typically start with a Welch 1402 and go from there. You will also need a induction heater and the 500 watt hobby ones on eBay work just fine. The rest is a variac and high current filament transformer, and a 10 or 15 amp one and step down transformer to vary the induction heater and you have a evacuation station not unlike what we used to build. The rest is glass work, chemical work, hydrogen reduction tube furnace, spot welders, and other small metal working tools. Piece of cake! 11-Dec-19 02:52 PM Type. Not babe. Hahahaha. Damn iPhone 11-Dec-19 02:59 PM Thanks Charles. Have a turbo to use rather than a diffusion pump. Will start off being a wobbly mess on lab jacks and retort stands. Later some sort of frame would be in order. The first challenge is finding enough space in the garage. 11-Dec-19 02:59 PM Would like a diffusion pump, but the only ones I have access to are full of mercury. And no wish to go the way of the hatter. 11-Dec-19 03:33 PM Expecting the glasswork to be tricky. Will be starting with attaching glass tubes to 12ax7 valves, flooding with air, then try and get them working again. 11-Dec-19 03:47 PM strongly recommend ensuring your turbo is rigidly mounted, they are not at all happy being moved while running. the rest can wobble at will :D 11-Dec-19 03:47 PM i'd really like to get into tubemaking at some point, too. do be extra sure you have some kind of mechanism for catching glass shards/dust/particulates, also; turbo won't like that much at all if you accidentally conk a tool against it and send chunks rushing in 11-Dec-19 03:47 PM one thing i've always wondered about with tubemaking.. do folks usually just get a glass-to-kf adapter and repeatedly cut off/melt on new tube bodies to it? 11-Dec-19 03:47 PM or is that what the compression port is for? 11-Dec-19 04:14 PM That's what the compression port is for 11-Dec-19 04:14 PM But you generally do reuse the tube and melt new ones onto it 11-Dec-19 04:22 PM @LRM it’s first red and after second it’s become green I get some voltage but it really small 0.01 voltage. When I connect the sensor by serial USB port to pc mks logger write tranduser are not conect or wire ... . Maybe my port serial is have problem or maybe my sensor have problem but tomorrow I will use another usb serial cable 11-Dec-19 04:22 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-3CE44.jpg 11-Dec-19 04:26 PM You need a USB to RS232 cable 11-Dec-19 04:26 PM Not serial 11-Dec-19 04:27 PM USB to db9 11-Dec-19 04:27 PM DB9 is just a physical size 11-Dec-19 04:28 PM I buy it . Omega model @Deleted User 11-Dec-19 04:28 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-315ED.jpg 11-Dec-19 04:35 PM ... are you sure it's a good adapter? 11-Dec-19 04:36 PM Every supplier say it’s best one . But they say I am not completely understand 11-Dec-19 04:36 PM What you suggested @Deleted User ? 11-Dec-19 04:37 PM not sure what you can get locally 11-Dec-19 04:37 PM Give me name ? @Deleted User 11-Dec-19 04:38 PM a max232 based adapter should work 11-Dec-19 04:38 PM or ft232rl 11-Dec-19 04:39 PM Uhm just test the adapter... 11-Dec-19 04:39 PM hook pins 2 and 3 together and type in your terminal emulator 11-Dec-19 04:39 PM you should get loop-back 11-Dec-19 04:39 PM that too 11-Dec-19 04:39 PM if that works then you know its not your adapter 11-Dec-19 04:39 PM it could still be the adapter 11-Dec-19 04:39 PM rs232 has become a very washed out, very abused spec 11-Dec-19 04:39 PM then just try both combinations of 2-2 3-3 and 2-3 3-2 11-Dec-19 04:39 PM For straight through and null modem 11-Dec-19 04:39 PM You get used to troubleshooting RS-232 problems when collecting vintage computer hehe 11-Dec-19 04:39 PM when most larger machines that was the interface.... terminal... 11-Dec-19 04:39 PM so yea you end up carrying around db25-db9 adapters db25 null modems, gender changers, lightboxes, smart boxes, etc... 11-Dec-19 04:45 PM @Conmega are there any clip on YouTube to check it on there. 11-Dec-19 05:21 PM i exclusively use the analog voltage output on my mks 901p, if you're not getting around 8.8V out of there then you've got some other issue 11-Dec-19 05:21 PM of note, do not tie the power ground and analog-voltage grounds together, they need to be kept separate per the manual 11-Dec-19 05:21 PM what kind of external power connector are you using there, what's the voltage? dumb question, but -- it's DC, right? 11-Dec-19 06:24 PM I got 8.9 voltage 5-6 . My voltmeters have some problem. But i guess r232 to usb cable maybe have some problem . @qualia 11-Dec-19 11:24 PM 8.9V may be too low, isn't the minimum specification 9V? 11-Dec-19 11:28 PM i think he meant the analog out voltage is 8.9V 11-Dec-19 11:28 PM and that he was having an issue with his voltmeter when he said before that he was not getting any voltage on the analog out 11-Dec-19 11:28 PM now he just needs to sort out the rs232 problems 12-Dec-19 12:07 AM @nmz787 @LRM i got analog voltage output 8.9 v mean pin 6 and 5 . But for Rs232 I don’t know it’s because of cable of sensor ? But I will test it with another RS232 to USB cable. 12-Dec-19 12:08 AM Oh 12-Dec-19 12:08 AM Yeah try the loopback connection as suggested before 12-Dec-19 12:08 AM Connecting rx to tx 12-Dec-19 12:08 AM Then open the serial terminal, whatever you send should come back as reply 12-Dec-19 12:09 AM In pc mean of sensor? 12-Dec-19 12:10 AM Pc to usb to serial... Serial rx to serial tx 12-Dec-19 12:10 AM No sensor involved in the test 12-Dec-19 12:10 AM That way you confirm if your PC can talk to the Usb-to-serial properly 12-Dec-19 12:10 AM If so, then your sensor has something up 12-Dec-19 12:10 AM Maybe the default protocol is in rs485 mode 12-Dec-19 12:10 AM Read the mks 901 manual and search "default" 12-Dec-19 12:13 AM For loop back is need special programs? To understand it ? 12-Dec-19 12:13 AM It talks about the factory default settings and how to revert to factory default 12-Dec-19 12:13 AM No 12-Dec-19 12:13 AM Just any serial terminal... Picocom, hyperterminal, python with pyserial, PuTTy 12-Dec-19 12:13 AM What OS are you using on your PC? 12-Dec-19 12:14 AM Windows 8.1 12-Dec-19 12:14 AM Do you ever use Python? 12-Dec-19 12:14 AM For programming? 12-Dec-19 12:14 AM No 12-Dec-19 12:14 AM MATLAB is could work ? 12-Dec-19 12:15 AM Umm 12-Dec-19 12:15 AM Probably, I haven't used matlab in like 10 years though 12-Dec-19 12:15 AM Is that what you were planning to use to talk to the sensor? 12-Dec-19 12:15 AM This looks like a simple 4 line example for matlab 12-Dec-19 12:15 AM https://www.mathworks.com/help/matlab/matlab_external/getting-started-with-serial-port-communication.html 12-Dec-19 01:57 AM Thanks for all help @nmz787 @LRM#6898 @Conmega#3813 @Spirit#0643 final i get some pressure on pc in logger and lab view but pressure in logger 380torr and in lab view 760torr . I guess it need some calibration in vacuum logger. 12-Dec-19 01:57 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-FAC5A.jpg 12-Dec-19 01:57 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image1-20C01.jpg 12-Dec-19 01:57 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-F0F6D.jpg 12-Dec-19 10:19 AM ooh neat, i didn't know mks made any official software for the 901p -- assuming that's what that is 12-Dec-19 10:52 AM Yeah, neither did I 12-Dec-19 11:03 AM The datasheet has several commands that give you pressure 12-Dec-19 11:03 AM You can read the pirani and piezo separately, as well as a calibrated pirani+piezo blend 12-Dec-19 11:03 AM @ahmadalinia 12-Dec-19 11:05 AM I will check it to understand how is that @Deleted User 14-Dec-19 04:13 AM So, this is tue future setup of the e-beam. Adam already commented on how i should get the turbo away from the working parts. 14-Dec-19 04:13 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191214_131149-61842.jpg 14-Dec-19 04:13 AM And I am thinking on buying a KF25 extension, clamp the "T" to the table and put the turbo away, on the bottom shelves. 14-Dec-19 04:13 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191214_131158_8-D7248.jpg 14-Dec-19 04:13 AM Is there any other concern about the KF25 tube to the turbo? 14-Dec-19 04:13 AM Can I measure vacuum at the turbo instead of at the T itself? 14-Dec-19 04:13 AM (I made the turbo flange to have one KF25 port just over the blades, and a KF16 port on the other side. 14-Dec-19 05:14 AM what kinda vacuum level do you need for e-beam stuff? 14-Dec-19 05:14 AM keep the hose between your turbo and chamber as short and wide as possible, and.. you'll definitely want the gauge closer to the chamber, as the pressure closer to the pump may be quite a bit lower than at the chamber itself 14-Dec-19 05:14 AM if im understanding correctly anyways 14-Dec-19 05:23 AM It depends on the emitter and mechanism. Anywhere from atmosphere to UHV, there is an ebeam system for every level 14-Dec-19 05:23 AM @Nixie measuring at the tee is ideal, but if it's directly connected at the turbo may be ok. 14-Dec-19 05:23 AM If you use an extension hose, you will want to really measure at the tee if possible. 14-Dec-19 05:35 AM Noted! I might have to look into KF25 Tees with a small KF16 addon. XDDD 14-Dec-19 09:55 AM @Nixie KF25 is tiny for e-beam 14-Dec-19 09:55 AM Also, look into isolators 14-Dec-19 09:55 AM They're big flexible flanges with a rubber outer shell, designed to dampen turbo vibrations 14-Dec-19 09:55 AM You mount the flange, but hang the turbo. 14-Dec-19 01:39 PM Kf25 isn't tiny for ebeam stuff. It's about the same diameter as 2.75" conflat hardware and we use that as the drift tube and beamline for our spare test injector that operates at -160kv, 20A pulsed. Much bigger beam than what you would be using too 14-Dec-19 01:39 PM Wait, kf40 is closer, my bad 14-Dec-19 01:40 PM just choking the turbo if you're putting it further away 14-Dec-19 01:42 PM Yeah, you lose pumping speed. Depends on the outgassing of the application. We go from 8” ion pumps to a 2.75" bellows extension for the test injector. Horribly choked but need the pump capacity 14-Dec-19 01:43 PM For an ebeam setup like this being limited by conduction a bit is not that bad 14-Dec-19 01:43 PM You really only need -5 range to run an Electron Gun 14-Dec-19 01:43 PM A turbo effectively straight piped to this thing and considering how small the system is is not going to pump it just fine 14-Dec-19 01:45 PM the only issue with straight piping is that it's not isolated at all 14-Dec-19 01:45 PM Yeah I wouldn't stress too much about it 14-Dec-19 01:45 PM so you have to either bolt the rest of the thing very rigidly, or put an isolator on it 14-Dec-19 01:47 PM Nixi and I had a discussion a while ago about this. It's not 100% perfect but he put some engineering controls in but this is prototyping so there's something to be said for just throwing it together and seeing what happens 14-Dec-19 01:47 PM Yeah the turbo might interfere, but you will know if it works or not 14-Dec-19 01:48 PM Always can optimize after you confirm beam 14-Dec-19 01:49 PM Yeah to move it further you just need a hose 14-Dec-19 02:49 PM 14-Dec-19 02:55 PM I am really interested in the result 14-Dec-19 02:55 PM A lot of people have said yeah turn a crt into a sem but I haven't seen anyone do it yet 14-Dec-19 02:57 PM I don't think a CRT will work 14-Dec-19 02:57 PM but a vidicon might! 14-Dec-19 09:54 PM Joined the server. 14-Dec-19 09:54 PM What have you done @AdamMcCombs 14-Dec-19 09:54 PM Oh no 14-Dec-19 09:54 PM Oh my 14-Dec-19 09:54 PM Lazer Law is Here 14-Dec-19 09:55 PM Hey I said if we're doing lasers we're doing them right 14-Dec-19 09:55 PM It's literally in the channel description 14-Dec-19 09:56 PM We're very responsible adults 14-Dec-19 09:56 PM "(be laser safe or I'm calling Twitters Laser Safety Officer Funranium)", so I guess we ware not being safe enough :PPP 14-Dec-19 09:58 PM I'm one to error on the side of not being a place that teaches someone how to melt their eyes 14-Dec-19 09:58 PM With the stuff we're discussing your eyes either exist or don't, so adequate safety equipment is assumed 14-Dec-19 10:00 PM Professional experience has taught me to NEVER assume adequate/correct safety equipment is available. Even in a damn Nobel Laureate's labs. 14-Dec-19 10:05 PM It's interesting there is more concern about laser safety than stuff like pulse cap banks, in which you will be either dead before you hit the floor, or blow a hole through an appendage (in addition to hearing damage and eye damage from intense discharges), or x-rays (plenty of damage mechanisms here). Is it just that eye damaging lasers are much more accessible and easy to get into for the average person? 14-Dec-19 10:06 PM Yes. 14-Dec-19 10:06 PM It seems that lasers tend to attract a very unique kind of disregard for safety 14-Dec-19 10:07 PM And you can mail order ready made devices that are dangerous. And it's easy. 14-Dec-19 10:07 PM Makes sense lol 14-Dec-19 10:07 PM You can't get the same ease of ordering ready made cap banks or X-ray equipment. 14-Dec-19 10:08 PM Well, depends lol. Plenty on eBay readily available. But yeah, people working with that stuff, especially here, generally are well knowledgeable about the risks 14-Dec-19 10:08 PM Though even small caps can fibrillate a heart 14-Dec-19 10:09 PM lasers are also dangerous-at-a-distance (to you and bystanders!) in a way that the above things are somewhat less so 14-Dec-19 10:09 PM plus i guess there's a big ooh-shiny factor in fricken' laz0rz 14-Dec-19 10:10 PM Yeah 14-Dec-19 10:10 PM It comes down to WWI and the deep distaste for intentionally blinding weapons. 14-Dec-19 10:10 PM What about a big big ooh-shiny factor? 14-Dec-19 10:10 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/toob_bright-E3BC9.jpg 14-Dec-19 10:10 PM is that your HeNe thing 14-Dec-19 10:10 PM Like a meter-long HeNe powerful enough to fry your eyes :^) 14-Dec-19 10:10 PM yes 14-Dec-19 10:11 PM How long does it take to heat up lol? 14-Dec-19 10:11 PM Just what I need, a laser channel to follow to reignite my interest in laser systems. I don't have the money to go down this path lol 14-Dec-19 10:11 PM Lol sorry 14-Dec-19 10:11 PM Then you're joining me and Mason in not having money 14-Dec-19 10:11 PM Joined the server. 14-Dec-19 10:11 PM rip our respective finances 14-Dec-19 10:11 PM Optics using photons is something I have yet to really dig into yet 14-Dec-19 10:11 PM But I'm seeing way to much cool stuff now 14-Dec-19 10:11 PM And this is not healthy for my prior commitments or wallet 14-Dec-19 10:12 PM Man I'd love to work on some pulsed power laser systems. Magnetic pulse compression is a big thing in pulsed power lasers. Need to get some metglass cores 14-Dec-19 10:13 PM Non-linear optics are addictive and will send you to the poorhouse. 14-Dec-19 10:13 PM If I ever get EXEDA up, you will definitely be seeing stuff on DIY FELs. EXEDA-FEL is a beamline in the works... 14-Dec-19 10:13 PM Guess that still counts as laser stuff here? 14-Dec-19 10:14 PM Laser and x-ray... 14-Dec-19 10:15 PM I can also use it for an x-ray pumped laser. I've got details on that too 14-Dec-19 10:15 PM I'm really interested in what the brightness of photo emmison can do in SEM and how that might be able to to push spherical aberation limited data collection rates 14-Dec-19 10:15 PM Pay close attention to jurisdictional rules on this. 14-Dec-19 10:15 PM Do not do this in CA, FL, IL, MA, or TX. 14-Dec-19 10:17 PM What the specific thing about those states? 14-Dec-19 10:17 PM Oh, the other big one is high power e-beam pumped gas lasers. Can directly pump a simple nitrogen gas laser extracting the beam to a nitrogen beamline of higher pressure. 14-Dec-19 10:17 PM I've got a lot of laser plans for EXEDA 14-Dec-19 10:18 PM Those states have a requirement for the registration of radiation producing machines. FL and MA additionally have registration requirements for lasers. Will they come hunt you down? No, but make sure you're on really good terms with your neighbors lest they drop a dime on you. 14-Dec-19 10:19 PM Oh yeah in that case Washington and Oregon have registration requirements as well 14-Dec-19 10:19 PM Good thing I'm not in any of those states lol. This won't happen for a very long time anyway, but I got all the background details already collected and waiting 14-Dec-19 10:20 PM Now the level to which they are enforced varies 14-Dec-19 10:21 PM Yeah. 14-Dec-19 10:24 PM Way too much awesome laser stuff that can be done with intense pulsed ebeams... Need to focus on other more pressing projects lol 14-Dec-19 10:25 PM The ALS at LBNL is a very fun facility. 14-Dec-19 10:28 PM Yeah, those synchrotron light sources are always cool to see. I got to tour the LCLS at Brookhaven a few years back 14-Dec-19 10:28 PM Maybe it was LCLS II, don't remember which 14-Dec-19 10:28 PM X-ray light sources are way out of the realm of possibility for a diy effort, but a source in the microwave range is very possible. Turns out the setup is surprisingly easy once you got the high power ebeam setup. Best sources of info are often the very old papers in the field lol 14-Dec-19 10:33 PM Welcome @Addison-110m! 14-Dec-19 10:37 PM Overall looks like a great call on the laser safety emphasis. Best to keep the discussions to really serious pursuits of advanced laser sciences and manufacturing tech instead of it devolving like apparently some other laser groups 14-Dec-19 10:46 PM Yeah. And on for example styropyro's discord, the laser professionals are AV visual effects people. 14-Dec-19 10:48 PM Visual effects people don't really even ever need glasses 14-Dec-19 10:48 PM They follow very strict "where to pew" specifications 14-Dec-19 10:48 PM which is above heads and into non-populated areas 14-Dec-19 10:48 PM (walls) 14-Dec-19 10:48 PM at least they're supposed to 14-Dec-19 10:51 PM Oh lol. Lighting stuff on fire or popping balloons with lasers is just god awful boring anyway. It's the same as just drawing arcs with hv. Too simple and mundane. No mastery of the engineering. Doing real useful science with it is the fun part! Manipulating raw power and energy for science is where it's at! 14-Dec-19 10:51 PM How do you read the channel description everyone keeps mentioning? 14-Dec-19 10:51 PM At the very top 14-Dec-19 10:51 PM How can you possibly scroll that far, sanely? 14-Dec-19 10:52 PM Nono, not in the chat 14-Dec-19 10:52 PM At the very top of the UI 14-Dec-19 10:52 PM On mobile it might be different 14-Dec-19 10:52 PM If you're on mobile, swipe left and it's going to be above the user list 14-Dec-19 10:54 PM Oh, my mobile view you have to click the people icon, which i don't think I've ever done before, and it's at the top there 14-Dec-19 10:54 PM the people icon is the same as swiping from right to left 14-Dec-19 10:55 PM Ah, i swiped from left to right before, never swiped from right before here either 14-Dec-19 10:55 PM I dont usually swipe from left either, really 15-Dec-19 12:51 AM we have a laser chan? 15-Dec-19 12:52 AM you're welcome 15-Dec-19 12:52 AM XD 15-Dec-19 12:09 PM yaaaaay 15-Dec-19 01:33 PM Funny smell in the house all day. Finally tracked it down to forgetting to turn off the heat on my ultrasonic cleaner last night. Uh oh! 15-Dec-19 01:35 PM whoops 15-Dec-19 01:35 PM any solvent in there? 15-Dec-19 01:35 PM What fluid are you using? 15-Dec-19 01:36 PM Just water 15-Dec-19 01:36 PM Although the manual says don't let the water level get more then 1cm below the mark, and of course I lost like half the water from evaporation over the night. The smell may have been the heater running and getting super hot because it wasn't contacting the water... 15-Dec-19 01:38 PM but the fill level is usually just for normal operation, so prevent some issues with resonance afaik 15-Dec-19 01:38 PM I guess the smell was the heater 15-Dec-19 01:38 PM good thing nothing burned down 15-Dec-19 01:38 PM I hope 15-Dec-19 01:38 PM Just my ego 15-Dec-19 07:25 PM My EXT255H did not disintegrated on first turn on My first high vacuum (no measurements yet though): https://www.youtube.com/watch?v=IFYLqB-NdiY&t=233s 15-Dec-19 07:30 PM @ZeptoBars very nice! 15-Dec-19 07:30 PM one tip: forget about that bluvac gauge for anything besides the foreline 15-Dec-19 07:30 PM it's going to leak like hell 15-Dec-19 07:30 PM the pump runs very smoothly though 15-Dec-19 07:30 PM that means your bearings are good! 15-Dec-19 07:35 PM @Deleted User Yeah, bought BlueVac before I had a clue... Worst part is that it was more expensive than 2xMKS 901p + 2xInficon BPG400 gauges that will be used once I got all the adapters and fittings... Will definitely sell it early next year to guys who do HVACs 15-Dec-19 07:35 PM ouch 15-Dec-19 07:35 PM yeah, I almost fell into the same trap 15-Dec-19 07:36 PM @Deleted User And it looks like you are correct - leak rate is the same no matter how I assemble the system, so it must be BlueVac... 15-Dec-19 07:38 PM just make sure whatever you're doing can't suddenly let air into the system 15-Dec-19 07:38 PM or can't bump it 15-Dec-19 07:38 PM running a turbopump like that, free standing, is quite dangerous as well 15-Dec-19 07:38 PM a big bump will crash the bearings and it's scrap 15-Dec-19 07:38 PM or worse, scrapes the blades against the housing 15-Dec-19 10:39 PM yawn Good morning! 15-Dec-19 10:39 PM yawn Good night! 15-Dec-19 10:47 PM change of shift 15-Dec-19 11:31 PM For these building turbo controllers: Internals of EXDC160: 15-Dec-19 11:31 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/ext255h-3-F8B2E.png 15-Dec-19 11:31 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/ext255h-4-0A52A.png 15-Dec-19 11:31 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/ext255h-5-EE77E.png 15-Dec-19 11:31 PM Does not look like magick 15-Dec-19 11:45 PM Internals of Pfeiffer TMP driver from a HiPace 80. 15-Dec-19 11:45 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-29A84.jpg 15-Dec-19 11:45 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image1-6289D.jpg 15-Dec-19 11:45 PM That photo is terrible sorry 15-Dec-19 11:45 PM Seven power semiconductors - I’m guessing three half-bridge fet pairs and a voltage regulator 16-Dec-19 12:05 AM They're all the same, essentially 16-Dec-19 12:05 AM Just a 3 phase inverter with some feedback 16-Dec-19 06:06 AM Why vacuum transducer could not detect under the 2.7E0 torr ? Is that because licking or another problem like sensor colibration or because vacuum pump ( I use single stages pump 150micron ) . Could please give me some ideas? 16-Dec-19 06:06 AM The sensor I use is mks901p 16-Dec-19 06:06 AM The voltage between pin 5-6 is 8.2 Volt after 30min pumping 16-Dec-19 09:26 AM Could be a leak, lots of outgassing, gauge problem or pump problem. Test both the pump and the gauge with the simplest setup you can get, IE roughing line directly to the gauge if you can. Don't run this for a super long time though since oil backstreaming from the roughing pump can degrade the gauge if it gets into the wrong places. 16-Dec-19 10:25 AM 2.7 torr seems pretty decent for a rough pump, I'd also guess leaking of you know your "best" vacuum should be .146 torr (150 micron or mbar) 16-Dec-19 10:25 AM I mean decent in the sense that it's most of the way depressurized 16-Dec-19 10:29 AM ah right 150 micron isn't a great roughing pump I guess... 16-Dec-19 10:29 AM this is generally how I test pumps after giving them a flush and fresh fluid 16-Dec-19 10:29 AM https://photos.app.goo.gl/bWRdJvThEo14LH2x9 16-Dec-19 10:29 AM the ultimate on that specific pump got down to 3x10-3 16-Dec-19 10:29 AM after running over night on new oil to ensure it got all the vapor out then closing the ballast and letting it run for awhile longer 16-Dec-19 11:48 AM I Test vacuum gauge. Yes problem is about sealing or licking about bad connection . If I use vacuum grease could solve licking problem ? @nmz787 @Conmega 16-Dec-19 11:50 AM Do NOT use vacuum grease 16-Dec-19 11:50 AM Why ? 16-Dec-19 11:50 AM Because it gets everywhere, can outgas, and will contaminate everything in your chamber 16-Dec-19 11:50 AM Show some photos of your complete setup 16-Dec-19 11:51 AM Okay. 16-Dec-19 11:51 AM It's more like use it in the right places 16-Dec-19 11:51 AM And I'm the right amounts 16-Dec-19 11:51 AM which is generally not in basic hobbyist setups 16-Dec-19 11:52 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-D0D5D.jpg 16-Dec-19 11:52 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image1-C0915.jpg 16-Dec-19 11:52 AM I'd start by not using any of that 16-Dec-19 11:52 AM Hook your gauge up directly to your pump 16-Dec-19 11:53 AM Those joints should be ok with no grease 16-Dec-19 11:53 AM yup 16-Dec-19 11:53 AM Now I don’t have access to chamber but tomorrow I will make some moves and send it in here . 16-Dec-19 11:54 AM the best way to start is to eliminate as many leaks as possible 16-Dec-19 11:54 AM so connect the gauge directly to the vacuum pump 16-Dec-19 11:54 AM Yeah you're building an e-beam system, you don't want any silicone grease 16-Dec-19 11:54 AM the gauge is very very unlikely to fail, so if you get a bad vacuum, it's 99% your pump 16-Dec-19 11:54 AM If you use vacuum grease, just make sure it's non silicone 16-Dec-19 11:54 AM It's gonna be more expensive grease 16-Dec-19 11:55 AM I will tomorrow check with vacuum grease supplier. But 16-Dec-19 11:56 AM don't use grease 16-Dec-19 11:56 AM Silicone grease "creeps" and can move across surfaces, if it gets into your beam path, it will turn into glass, which is dielectric and cause charging issues (beam deflection) 16-Dec-19 11:56 AM Gauges is okay I connect it derictly to pump and it show 200micro or .20 torr 16-Dec-19 11:57 AM Cool 16-Dec-19 11:57 AM Wow I don’t know that thanks for your suggestions about vacuum grease 16-Dec-19 11:59 AM Grease is perfectly fine, depends on your application. I'm building a coating system for teflon like compounds which use a silicon atom group for bonding to the surface, for this application silicone grease shouldn't be any issue 16-Dec-19 11:59 AM @Deleted User most grease comes with vapor pressure spec... Not sure why you're saying so strongly not to use 16-Dec-19 12:00 PM I've got quite a bit of silicone grease in my custom feedthroughs with two large viton orings as well 16-Dec-19 12:00 PM I am make some e-beam system 16-Dec-19 12:00 PM But yeah I'm not going for super high vacuum, no material issues with my application and I have a lot of pumping speed 16-Dec-19 12:01 PM it's just not needed 16-Dec-19 12:01 PM Yeah if you need grease, after making the best effort to properly grease-free fix the leaks, then get something non silicone @ahmadalinia 16-Dec-19 12:02 PM Okay @nmz787 16-Dec-19 12:03 PM there's always an easy-ish way to find leaks 16-Dec-19 12:03 PM @Deleted User eh that seems like a stretch to assert. My setup is using a plastic salad bowl with holes drilled in and rubber stoppers with piano wire shoved through for electrical feedthroughs... Its doing OK without grease, but I'll grease them anyway before I get going with the rest of the systet 16-Dec-19 12:03 PM @ahmadalinia get a small tank of regular party helium and spray it around your joints 16-Dec-19 12:03 PM it's probably only around $20 to get a small one and... well, it's helium 16-Dec-19 12:03 PM I doubt that will affect the pressure gauge significantly 16-Dec-19 12:03 PM you'll see massive spikes in the vacuum readings if it's leaking where you're spraying 16-Dec-19 12:03 PM massive relative to noise 16-Dec-19 12:04 PM Why not just use air? 16-Dec-19 12:04 PM because air has very little helium in it 16-Dec-19 12:04 PM If I use helium it could show where is leak is ? 16-Dec-19 12:04 PM Why helium is important for raising pressure? 16-Dec-19 12:04 PM Vs air 16-Dec-19 12:04 PM because it's the smallest molecule that gets through everything 16-Dec-19 12:04 PM that's why helium leak detectors use... helium 16-Dec-19 12:05 PM Ah 16-Dec-19 12:05 PM I thought it was just because it was rare and could easily differentiate in mass spec read out 16-Dec-19 12:05 PM that is true, but not the primary reason 16-Dec-19 12:05 PM it's because it permeates through everything 16-Dec-19 12:05 PM Mmm 16-Dec-19 12:06 PM this is also why HeNe lasers slowly expire over the decades 16-Dec-19 12:06 PM helium slooooooowly leaks through the glass 16-Dec-19 12:06 PM It does depend on where your gauges are in the system though, I have a differentially pumped system and leaks downstream of gauges might be hard to detect with this easy method 16-Dec-19 12:07 PM he seems to be doing a regular system with one forepump and one diffpump 16-Dec-19 12:08 PM The other reason to use helium is it can sometimes interact with guages differently causing the pressure rise or dip 16-Dec-19 12:08 PM there's that too 16-Dec-19 12:08 PM it changes the heat conductivity of air 16-Dec-19 12:08 PM which will mess up the pirani 16-Dec-19 12:08 PM (good in this case) 16-Dec-19 12:08 PM Especially on guages that rely on some sort of thermal sense 16-Dec-19 12:08 PM Exactly 16-Dec-19 12:08 PM It's the same reason using alcohol works 16-Dec-19 12:09 PM helium is useful for leak detection even without a mass spec because of its properties alone 16-Dec-19 12:09 PM Alcohol vapor, sounds good 16-Dec-19 12:09 PM It just goes in the other direction due to how large the molucuels are 16-Dec-19 12:09 PM I reckon you'd want helium here 16-Dec-19 12:09 PM because if you can see a leak while pumping, helium will make it HUGE 16-Dec-19 12:10 PM Helium is more sensitive with larger leaks when not using a mass filter detector 16-Dec-19 12:10 PM Seems like starting with a big molecule might show the worst leaks first, then change to smaller molecule to show harder to solve leaks 16-Dec-19 12:10 PM Smaller leaks alcohol is probably going to better 16-Dec-19 12:11 PM smaller leaks? 16-Dec-19 12:11 PM you mean larger? 16-Dec-19 12:11 PM Smaller because it blocks it up maybe? 16-Dec-19 12:11 PM If a leak is small or has a long conduction path it can be hard to get a lot of helium to flow through it 16-Dec-19 12:11 PM So when you drip alcohol on it the alcohol vapor will enter the system and show where the leak is 16-Dec-19 12:13 PM What I must use alcohol or helium gas ? 16-Dec-19 12:13 PM try alcohol first 16-Dec-19 12:13 PM cheaper than buying a tank of helium 16-Dec-19 12:13 PM Yeah if you don't have helium 16-Dec-19 12:14 PM I will use alcohol which kind alcohol is better or just some industrial alcohol is okay? 16-Dec-19 12:14 PM All you do is drip it along the joints looking for a pressure rise or dip indicting the alcohol hit the leak and entered the system 16-Dec-19 12:14 PM I'd use ethanol 16-Dec-19 12:14 PM so... vodka 16-Dec-19 12:14 PM lol 16-Dec-19 12:14 PM Isopropanol works fine 16-Dec-19 12:14 PM Ethonal is better 16-Dec-19 12:14 PM wouldn't iso attack some things? 16-Dec-19 12:15 PM Yeah 16-Dec-19 12:15 PM But it should evaporate really fast 16-Dec-19 12:15 PM And it shouldn't attack anything being used for vacuum service 16-Dec-19 12:15 PM Yea on my small chamber I could only get to like 1x10-4~ or so on with the turbo is weird, I dowsed all the joints and never saw even a slight fluctuation in pressure... so either I had a horrible leak or just I dunno horrible outgassing 16-Dec-19 12:16 PM It can be hard to get the alcohol in conflat 16-Dec-19 12:16 PM I was working on making a much simpler chamber than even what I had so I could just test the turbo, and I had to wait to get some sandpaper to lap some KF fittings that had some scratches 16-Dec-19 12:16 PM really? it seemed to flow in there pretty easily to me 16-Dec-19 12:17 PM To the knife edge 16-Dec-19 12:17 PM For alcohol to work it liquid pretty much had to touch the actual leak 16-Dec-19 12:18 PM I mean if you have the fittings tightened down to the point that they touch, which is generally how it is yes but sometimes they don't always, you can use the alignment slots on that are 180 degrees apart to kinda get it down in there 16-Dec-19 12:18 PM Those aren't alignment slots 16-Dec-19 12:18 PM They are there for leak checking 16-Dec-19 12:18 PM maybe I wasn't getting it into all of them perfectly but yea I dunno, it was the first time I tried to get a chamber together, was kinda bound to not just work 16-Dec-19 12:18 PM ah lol, I thought I had read somewhere that you stick something in there to get them aligned when first putting flanges together, maybe thats so you CAN use them for leak checking 16-Dec-19 12:19 PM Yeah you should align them for leak checking 16-Dec-19 12:19 PM Makes it easier only spritzing helium I'm one spot is all it is 16-Dec-19 12:20 PM but yea now that I have an RGA as soon as I get a simple little setup going I can have a nice leak detector for building larger chambers 16-Dec-19 12:20 PM I even have some KF40 hoses I can use to hook to a larger chamber to use for said leakchecking 16-Dec-19 12:21 PM Need to put the rga on the sem 16-Dec-19 12:21 PM oh? whys that? 16-Dec-19 12:21 PM other than for leak checking 16-Dec-19 12:21 PM Yup 16-Dec-19 12:21 PM ah yea 16-Dec-19 12:21 PM dunno how that would be easily done... 16-Dec-19 12:22 PM And to see if you have hydrocarbon problems still 16-Dec-19 12:22 PM Ion pump? 16-Dec-19 12:22 PM wouldn't the RGA not appreciate having the filament cycled very often? 16-Dec-19 12:22 PM Eh it's pretty ok 16-Dec-19 12:22 PM honestly I should just make it a point to tear the thing down and replace all the orings lol 16-Dec-19 12:22 PM especially on those valves 16-Dec-19 12:22 PM Maybe not that 16-Dec-19 12:22 PM That's a really really big project on a ds130 16-Dec-19 12:23 PM yea.... but if like for example I find a leak down in the bottom valve... the entire top has to come off anyway... 16-Dec-19 12:23 PM Oh I thought you meant column 16-Dec-19 12:24 PM oh the column yea I'd like to avoid that 16-Dec-19 12:24 PM I mean more the back valving/stage stuff 16-Dec-19 12:24 PM since those butterfly's orings with the moving valves are probably not super happy after forever and aging 16-Dec-19 12:25 PM How I use alcohol just drop it in connection and if i see it’s faster evaporate it show on that connection i have licking . Or it show on gauge ??? 16-Dec-19 12:26 PM It's going to show on the gauge 16-Dec-19 12:26 PM Yeah 16-Dec-19 12:26 PM It might be small, it might be delayed, and it might only last a second 16-Dec-19 12:26 PM It’s better. Thanks thanks 16-Dec-19 12:26 PM So watch the guage while you drip it on 16-Dec-19 12:26 PM If you have a digital osiliscope I like to hook the pressure reading up to that and monitor that way 16-Dec-19 12:27 PM the gauge is digital 16-Dec-19 12:27 PM no point in doing that 16-Dec-19 12:27 PM The MKS software has plotting right? 16-Dec-19 12:27 PM you can just read it with the software quickly 16-Dec-19 12:27 PM yes 16-Dec-19 12:27 PM Well seeing the Trace is really useful 16-Dec-19 12:27 PM the mks software plots 16-Dec-19 12:28 PM Mks have plots 16-Dec-19 12:28 PM Oh I thought he was having problems with the software still 16-Dec-19 12:28 PM It’s okay 16-Dec-19 12:28 PM Yea its just really badly made software haha. 16-Dec-19 12:28 PM Even then how fast is the update speed? 16-Dec-19 12:28 PM No problem on software is solved 16-Dec-19 12:28 PM Thanks for your support for all of you are 16-Dec-19 02:54 PM anyone here have any experience with titanium sublimation pumps? 16-Dec-19 02:55 PM Yeah? 16-Dec-19 02:55 PM i'm looking to stick some Ti coils in a KF tee, run some amps through, and magically get down to UHV 16-Dec-19 02:56 PM Yup 16-Dec-19 02:56 PM Well kf is still not going to hit uhv 16-Dec-19 02:56 PM TiSub reacts pretty quickly as well, so works well at uhv but I don't know about -7 range 16-Dec-19 02:57 PM hmm 16-Dec-19 02:57 PM are there crushable/single-use KF gaskets that i'd be better off using for this? or should i ditch it all and go 100% CF? 16-Dec-19 02:59 PM What vacuum do you want? 16-Dec-19 02:59 PM -14 16-Dec-19 02:59 PM ofc 16-Dec-19 02:59 PM -14? 16-Dec-19 02:59 PM (not really but) 16-Dec-19 02:59 PM -7 seems like as low as i can get out of my turbo 16-Dec-19 02:59 PM In tor? 16-Dec-19 03:00 PM yeah i'm kidding 16-Dec-19 03:00 PM i'm kind of just chasing numbers, but the goal is single ion trapping 16-Dec-19 03:00 PM -11 then? 16-Dec-19 03:00 PM so it seems like lower = longer trap time, but i haven't done the calculations 16-Dec-19 03:00 PM -11 is doable just with igp 16-Dec-19 03:00 PM Assuming no gas load 16-Dec-19 03:00 PM Tisub doesn't pump every thing so it's usually paired up with something else 16-Dec-19 03:02 PM don't igps have the same issue? 16-Dec-19 03:02 PM Yeah but igp still pumps argon at 1% of what it does for nitrogen 16-Dec-19 03:03 PM nod 16-Dec-19 03:03 PM part of the appeal of TiSub is that i just have all the parts lying around 16-Dec-19 03:03 PM -7 mbar is doable with KF but I don't think -7 torr is 16-Dec-19 03:03 PM i have two kf16 ports on my chamber and i'm at 5e-7 now 16-Dec-19 03:04 PM also TiSub pumps aren't pure titanium filaments afaik 16-Dec-19 03:04 PM Ti/Mo i believe 16-Dec-19 03:04 PM yeah 16-Dec-19 03:04 PM -7 is totally doable 16-Dec-19 03:05 PM baking? 16-Dec-19 03:05 PM It's getting close to being limited by diffusion through the o-ring 16-Dec-19 03:05 PM Yes and no 16-Dec-19 03:05 PM no baking here, yet 16-Dec-19 03:05 PM If you have contamination definitely baking 16-Dec-19 03:05 PM Else no you can hit it eventually 16-Dec-19 03:06 PM i might try the janky KF TiSub anyways with the gauge right on the end to see how long UHV conditions last, if at all 16-Dec-19 03:06 PM Yeah I'd say go for it 16-Dec-19 03:07 PM just kinda concerned about the reactivity of Ti.. don't want a titanium fire in my messy bedroom 16-Dec-19 03:07 PM Yeah 16-Dec-19 03:07 PM As long as there's no air... 16-Dec-19 03:07 PM it'll burn up all the oxygen inside 16-Dec-19 03:07 PM easy peasy 16-Dec-19 03:07 PM But yeah have fun getting the titanium out afterwards 16-Dec-19 03:08 PM 8D yaaay 16-Dec-19 03:08 PM 'how do i clean off sputtering' is still a huge open question that's honestly got me afraid for my viewports 16-Dec-19 03:08 PM acid 16-Dec-19 03:08 PM I have probably spent days cleaning titanium off of shit 16-Dec-19 03:08 PM Oh yeah dont let it hit your glass or ceramic 16-Dec-19 03:08 PM Not a fun time 16-Dec-19 03:08 PM That was 9 hours of my life I'm not getting back 16-Dec-19 03:10 PM oof 16-Dec-19 03:10 PM yeah i see a lot of commercial TSPs have big funky-looking multi-bounce baffles 16-Dec-19 03:10 PM sometimes cryocooled 16-Dec-19 03:11 PM metal mesh stuffing perhaps? 16-Dec-19 03:11 PM it'll eat your pumping speed but act as a baffle 16-Dec-19 03:11 PM At uhv that would be awful 16-Dec-19 03:11 PM So if you cool down a TiSub it pumps more gasses faster 16-Dec-19 03:12 PM gotta ask a local machinist for all the SS304 swarf they've got 16-Dec-19 03:12 PM So if you want to pump n2 it has to be below room temp 16-Dec-19 03:12 PM I would look into non evaporable getters 16-Dec-19 03:12 PM Iv been getting into them for xhv systems 16-Dec-19 03:12 PM Like -12 range 16-Dec-19 03:12 PM But you can do neg coatings on the inside of chambers 16-Dec-19 03:14 PM how do you measure pressure at XEV? 16-Dec-19 03:14 PM So instead of outgassing or contaminating overtime the chamber itself pumps after activation at bake out 16-Dec-19 03:14 PM seems like ion gauges hit their x-ray limit at like -11 16-Dec-19 03:15 PM The hydrogen contamination rate of the field emmison tip inside of the sem 16-Dec-19 03:15 PM There's this emmison curve you can corralate to hydrogen pressure 16-Dec-19 03:15 PM that's amazing 16-Dec-19 03:17 PM Yeah it's like waiting for a few hundred atoms to interface with the lattice structure of the tungsten 16-Dec-19 03:17 PM Thus changing the field emmison pattern of the tip and the amount of emmison current down the column 16-Dec-19 03:20 PM anything i should look for in an ebay igp, if i decide to go that route? 16-Dec-19 03:20 PM It's very hit and miss 16-Dec-19 03:20 PM If you find one that looks like it's still sealed then... Maybe? 16-Dec-19 03:20 PM I've had failure to chooch on freshely rebuilt IGPs before 16-Dec-19 03:20 PM They also have a limited life period... At -7 or -8 range 5-7 years is pretty common 16-Dec-19 03:24 PM chooch? 16-Dec-19 03:24 PM Run at all 16-Dec-19 03:24 PM Do it's intended job 16-Dec-19 03:25 PM in theory the EXT255 can go down to -10 on its own, or so the manual claims.. perhaps i need to, like, do some more cleaning/leak hunting and try to get another decade out of it 16-Dec-19 03:25 PM ah ok 16-Dec-19 03:26 PM Yeah -10 is past what o-rings can do 16-Dec-19 03:26 PM I'd say do a bake if you want to hit -8 16-Dec-19 03:28 PM I've always assumed that -10 is what the turbo manufacturers specify when you like... weld the turbo shut 16-Dec-19 03:29 PM Nah just when you do everything perfectly right and bake the hell out of it 16-Dec-19 03:30 PM KF turbos? 16-Dec-19 03:30 PM gotta get my gate valve set up (and the nice KF-CF roughing valve @Applied_Ion threw at me a million years ago) which all comes back to being a pneumatics problem, again 16-Dec-19 03:30 PM i don't think I've seen a KF turbo claim -10 16-Dec-19 03:31 PM With good reason 16-Dec-19 03:31 PM CF turbos should get to -10 16-Dec-19 03:33 PM yeh mine's 6" CF 16-Dec-19 06:57 PM Titanium is very hard to clean off with acid. Supposedly you can dissolve it using boiling concentrated HCl. (HCl vapor everywhere!) Usually Ti etching is done with Kroll’s reagent, which is mixed HNO3 and HF. (!!) Can’t use this on glass obviously. Both options are likely to damage stainless components... or pickle them really clean. 16-Dec-19 07:02 PM HF, H the F no. That's my motto 16-Dec-19 07:03 PM Kapton over the viewport inside is not ideal for colour vision but it’s what we do for our sputters and evaporator, it’s the best option I know of. 16-Dec-19 07:03 PM Also, sputter with a chromium target is so beautiful, it’s intense blue, a remarkable change just from the target material, standard argon plasma which is more white and less bright 16-Dec-19 10:50 PM Moin! 16-Dec-19 11:06 PM hiiiiii 17-Dec-19 06:40 AM Speaking of TSPs.... if someone needs a REALLY big one with some unknown metal crush flange type with about a 14" diameter on top and about 3 feet tall.... leme know :) 17-Dec-19 08:35 AM Hi 17-Dec-19 08:43 AM DIY vacuum grease anyone? 17-Dec-19 08:45 AM if your having problem sealing you either have dirt between the oring and surfaces, damaged surfaces, or a bad oring... replace or fix one or all of those and really you shouldn't need a DROP of any kind of grease 17-Dec-19 08:45 AM grease is like a bandage not a solution to a problem. 17-Dec-19 08:46 AM I made a big aluminum groove with a CNC. The botton is not perfect 17-Dec-19 08:46 AM For oring 17-Dec-19 08:47 AM use varying levels of sandpaper and wetsand on a surface plate or like a mirror or something to finish the surface better if you expect a surface finish problem 17-Dec-19 08:47 AM good way to save damaged KF flanges and such too 17-Dec-19 08:47 AM but if you made a grove for the oring to sit in is it too deep for the oring? 17-Dec-19 08:47 AM designing a grove for an oring to sit in is apparently a bit of a science @AdamMcCombs linked a doc in #resources I think about design of that 17-Dec-19 08:48 AM I mean, the lenght is 1600 mm. 17-Dec-19 08:48 AM How rough are we talking about? 17-Dec-19 08:48 AM Is really big oring 17-Dec-19 08:48 AM I can see CNC router pattern in the groove 17-Dec-19 08:48 AM some circles 17-Dec-19 08:48 AM In the aluminum 17-Dec-19 08:48 AM I will try sanding 17-Dec-19 08:50 AM I'd think that shouldn't be a problem, but one dimension of the oring doesn't mean much, when clamped does the metal surfaces come down into contact or does the oring keep the surfaces slightly apart? 17-Dec-19 08:51 AM I havent tested yet. I dont know if the metal surface come down into contact yet 17-Dec-19 08:51 AM how do you know you have leaking problems yet then? 17-Dec-19 08:51 AM if you've never sealed it and tried pumping down? 17-Dec-19 08:51 AM Im just assuming it will leak 17-Dec-19 08:52 AM lol test first, not like your making conflat and wasting copper gaskets testing 17-Dec-19 08:52 AM Back to the original question you can use do oil, but it's not going to seal anything more than small surface imperfections 17-Dec-19 08:52 AM I just read diffusion pump oil have 99% outgassing 17-Dec-19 08:53 AM It's not as good as real grease in a lot of ways 17-Dec-19 08:53 AM That being one of them 17-Dec-19 08:54 AM Maybe mercury is better sealing 17-Dec-19 08:54 AM Just kidding 17-Dec-19 09:04 AM I machined my o-ring groove with a rotary table on a mill, groove in both stainless steel and copper. If you use a good end mill and take a shallow finishing cut it should be more than good enough to seal 17-Dec-19 09:05 AM I must be difficult to machine stainless steel 17-Dec-19 09:05 AM Not really 17-Dec-19 09:05 AM Well depends on what alloy I guess. But I think most flanges are 304 stainless and that's easy 17-Dec-19 09:06 AM Did you use high RPM? 17-Dec-19 09:07 AM I calculated the right feed and speeds from the Machinist's handbook, if I remember correctly it was pretty fast with a 1/4" endmill, like 3000 RPM+ 17-Dec-19 09:07 AM Use solid carbide endmills of course, small ones are so cheap now it's a no-brainer 17-Dec-19 09:12 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20191216_134833-5B8F4.jpg 17-Dec-19 09:12 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20191216_134824-48F78.jpg 17-Dec-19 09:12 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20191216_122225-ECD43.jpg 17-Dec-19 09:13 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20190321_160938-7F4DA.jpg 17-Dec-19 09:13 AM I have a chinese spindle. It works up to 24.000 rpm. I think it doesn't have torque at 3000 rpm 17-Dec-19 09:14 AM Oh, that should still be fine. Use a even smaller endmill if you need to. I need to go slow because I feed manually, with a router you can go fast 17-Dec-19 09:14 AM For something like this you want as much rigidity as possible. Also make sure the spindle is trammed in with no tilt in x or y axis, so you cut flat on the bottom to get a good surface finish 17-Dec-19 09:19 AM Maybe I can try sanding 17-Dec-19 09:19 AM 1100 aluminum is a pain to work with 17-Dec-19 09:21 AM You don't want to have to sand everywhere. I had to put in some elbow grease in sanding areas where I feed in vertically, but for such a long groove you might miss a spot and the corners are a pain. 17-Dec-19 09:22 AM Elbow grease is for sanding? 17-Dec-19 09:22 AM No literal grease of course 17-Dec-19 09:23 AM 17-Dec-19 11:50 AM Joined the server. 17-Dec-19 11:51 AM welcome back 17-Dec-19 12:22 PM I try to not eat mayonnaise 17-Dec-19 01:36 PM Joined the server. 17-Dec-19 01:38 PM and welcome back to you, too 17-Dec-19 04:25 PM Joined the server. 17-Dec-19 04:25 PM salutations! o/ 17-Dec-19 07:59 PM Joined the server. 17-Dec-19 07:59 PM Welcome! 17-Dec-19 08:04 PM Welcome! 17-Dec-19 08:04 PM Joined the server. 17-Dec-19 08:05 PM look who it is 17-Dec-19 08:05 PM Welcome! 17-Dec-19 08:06 PM thanks! 17-Dec-19 08:08 PM Hey welcome! 17-Dec-19 08:11 PM how do you all find servers like this? 17-Dec-19 08:11 PM Twitter? 17-Dec-19 08:11 PM that's how i just learned...love the channel topics 17-Dec-19 08:11 PM I accidently stumbled upon it while browsing twitter, which is something I also rarely do 17-Dec-19 08:12 PM Admitidly we should have a website 17-Dec-19 08:12 PM I don't even have a twitter lol 17-Dec-19 08:12 PM Right now www.vacuumhackers.com just is am invite page 17-Dec-19 08:12 PM I found it by word-of-mouth 17-Dec-19 08:13 PM From someone who found it on Twitter? 17-Dec-19 08:13 PM i'm considering a two stage vacuum for a cathode ray tube and some metal sputtering, investigating what the minimum requirements might be 17-Dec-19 08:13 PM Well you're definitely in the right place for that 17-Dec-19 08:14 PM yea I don't do the twits either. I originally dl'd Discord while involved with the ODrive project, then that spawned Reps' then another recommendation later and I'm here 17-Dec-19 08:14 PM Probably, from @Applied_Ion 17-Dec-19 08:14 PM The cathod ray is going to need the better vacuum for sure 17-Dec-19 08:14 PM so, basically GitHub -> Discord -> Word of Mouth on Discord lol 17-Dec-19 08:14 PM From what I know most CRTs are around 1e-5 mbar 17-Dec-19 08:14 PM with gettering inside(?) 17-Dec-19 08:15 PM If anyone has other server recommendations for maker/hacker/physics/etc I'm all ears! 17-Dec-19 08:15 PM Yeah it's what you need for a hot electron source 17-Dec-19 08:15 PM So you don't burn up the cathod 17-Dec-19 08:15 PM oh interesting 17-Dec-19 08:16 PM Mean free path wise you can get away with a bit less 17-Dec-19 08:16 PM A diffusion pump system may seem cheap but by the time you do everything else to make it work turbo pumped is usually a better choice 17-Dec-19 08:17 PM i supposed i should be on the lookout for something i can use for other projects to come as well as my single stage will not cut it 17-Dec-19 08:17 PM I've been keeping this listing to myself in hopes that I could ship it, but this is a good fit for you in terms of a backing pump @samy https://www.ebay.com/itm/Leybold-Trivac-D2-5E-Vacuum-Pump-w-Hanning-Elektro-werke-E7B4B3-7-Motor/172793859911 17-Dec-19 08:17 PM plenty of people here can attest to how quiet and fast these trivacs are 17-Dec-19 08:17 PM not sure if there are cheaper listings on US ebay though, look around! 17-Dec-19 08:18 PM What do you mean by single vs 2 stage? 17-Dec-19 08:18 PM ebay.com/itm/LEYBOLD-TRIVAC-D2-5E-140000-VACUUM-PUMP-W-HANNING-E7B4B3-7-351-MOTOR-230V-1PH-3/292748465096 Is a nicer unit 17-Dec-19 08:18 PM As in the rotary pump or using a rotary followed by a high vacuum pump? 17-Dec-19 08:19 PM i use a 0.05 mbar single stage pump for small projects 17-Dec-19 08:19 PM that's enough for backing most turbopumps, so you shouldn't need to buy another forepump 17-Dec-19 08:20 PM thanks @Deleted User! 17-Dec-19 08:20 PM I mean unless it's a harbor freight ac service pump 17-Dec-19 08:20 PM lol yes 17-Dec-19 08:20 PM there's a big difference between a 0.05mbar label and 0.05mbar ultimate vacuum 17-Dec-19 08:21 PM ahh 17-Dec-19 08:21 PM so would i use that with a turbopump? 17-Dec-19 08:22 PM there's two categories of pumps 17-Dec-19 08:22 PM a foreline/backing pump, which is used to remove the majority of the air in a system 17-Dec-19 08:22 PM and a high vacuum pump, which knocks the hard-to-get molecules out 17-Dec-19 08:22 PM Knocks being a very good description of molecular pumping in general 17-Dec-19 08:22 PM the foreline pump is attached to the exhaust of the high vacuum pump 17-Dec-19 08:22 PM as there exist no turbopumps(in practice, shush I know edwards makes a frankenpump) that can vent directly to the atmosphere 17-Dec-19 08:22 PM or any other high vacuum pump for that matter 17-Dec-19 08:22 PM diffusion, ion, turbomolecular, turbodrag 17-Dec-19 08:22 PM vacuum measurement is also split into several categories of gauges, but we can link a few that will cover absolutely everything you'll need and you can forget about that 17-Dec-19 08:22 PM one thing to note with most high vacuum pumps is that almost none of them, with the exception of a pure turbodrag pump with no molecular(jet-like turbine) stage, are capable of surviving a vent to atmosphere, nor can they run at atmosphere 17-Dec-19 08:26 PM interesting 17-Dec-19 08:26 PM oil diffusion pumps generally do physically survive a vent, but the oil can... combust rapidly, and you'll need a supercleaning with replacement 17-Dec-19 08:26 PM for clean processes and simple use, you'll want a turbomolecular or turbodrag pump, because oildiffs take a long time to start(10-30 minutes) and an equally long time to stop(assuming you have no gate valve to keep them under vacuum) 17-Dec-19 08:26 PM in short, turbomolecular pumps are just large, extremely precise fans that spin at incredibly high speeds(up to 90 000 rpm in small pumps), and just... knock the molecules down to the "high pressure" exhaust 17-Dec-19 08:30 PM If you want a crash course on vacuum systems I gave a very off the cuff talk on vacuum technology for a high school student group, staying with rotary pumps and moving through diffusion, turbo, ion, and a couple of vacuum guage technologies 17-Dec-19 08:30 PM https://youtu.be/RPr2ANv0_-0 17-Dec-19 08:30 PM why did you link this after I started typing up another paragraph :P 17-Dec-19 08:31 PM haha! thank you both -- that's helpful @Deleted User 17-Dec-19 08:31 PM @AdamMcCombs absolutely, I'll watch this tonight 17-Dec-19 08:31 PM Lol sorry 17-Dec-19 08:31 PM i'd prefer something aimed towards middle school level but I'm appreciative of what I can get 17-Dec-19 08:31 PM Adam explains things well 17-Dec-19 08:31 PM as for practical hardware 17-Dec-19 08:31 PM first order of business - pick up a couple of these 17-Dec-19 08:31 PM https://www.ebay.com/itm/MKS-901P-11040-MicroPirani-Piezo-Loadlock-Vacuum-Pressure-Transducer/202636260062 17-Dec-19 08:31 PM one is enough, two is good :P 17-Dec-19 08:31 PM this is the most affordable, widest range low to medium-high vacuum gauge on ebay right now 17-Dec-19 08:31 PM and it survives atmosphere! 17-Dec-19 08:32 PM Oh apparently I also talk about molecular flow in that video 17-Dec-19 08:32 PM Cool 17-Dec-19 08:33 PM edited the link with a cheaper listing 17-Dec-19 08:33 PM that everyone here bought from 17-Dec-19 08:33 PM (including me) 17-Dec-19 08:33 PM oh nice, and i will likely need this? 17-Dec-19 08:34 PM I had like minutes of notice and basically just talked about vacuum for an hour 17-Dec-19 08:34 PM Yeah 17-Dec-19 08:34 PM you will absolutely need it 17-Dec-19 08:34 PM If you want to measure vacuum 17-Dec-19 08:34 PM measuring is fun 17-Dec-19 08:34 PM that is your vacuum gauge that will take you from atmospheric pressure to around 1*10^-5 mbar 17-Dec-19 08:34 PM but not QUITE -5 17-Dec-19 08:34 PM 5*-4 ish 17-Dec-19 08:34 PM There's other ways but it's a really good guage that covers a wide range of pressures 17-Dec-19 08:34 PM it's also cheap and I regret my other purchases ;~; 17-Dec-19 08:35 PM it mentions no seal available, something i can just laser i hope 17-Dec-19 08:35 PM It's also an unbelievably good price 17-Dec-19 08:35 PM it comes with an o-ring and centering ring 17-Dec-19 08:35 PM What's your chamber like? 17-Dec-19 08:35 PM "Please note that there are no more seals available. Picture #1 shows a seal, but it is not included." 17-Dec-19 08:35 PM ah 17-Dec-19 08:35 PM well, not to worry, they're single digit dollars 17-Dec-19 08:35 PM I have a reliable Chinese seller I bought from several times 17-Dec-19 08:36 PM Ah so that's a standard KF vacuum seal 17-Dec-19 08:36 PM KF16 yep 17-Dec-19 08:36 PM I think it's KF16 17-Dec-19 08:36 PM @AdamMcCombs nothing fancy, right now just https://www.amazon.com/gp/product/B019RZNYPG/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 17-Dec-19 08:36 PM you're going to have to ditch that 17-Dec-19 08:36 PM Ah 17-Dec-19 08:36 PM Yeah 17-Dec-19 08:36 PM which has been for kitchen projects 17-Dec-19 08:36 PM it's completely unsuitable for high or even medium vacuum 17-Dec-19 08:36 PM great for degassing though! 17-Dec-19 08:36 PM That's not taking you -5 for a cathod ray 17-Dec-19 08:37 PM I will link you to a build I did 17-Dec-19 08:37 PM that didn't cost too much and should be okay for experiments with a few modifications 17-Dec-19 08:37 PM so, in general, vacuum systems are built out of either one of two systems 17-Dec-19 08:37 PM KF, KwikFlange, also called NW in ISO/EU 17-Dec-19 08:37 PM It's a more affordable system that consists of flat flanges that sandwich an o-ring made out of Viton(FKKM, FKM) fluoropolymer, which is essentially a fancy vacuum rubber 17-Dec-19 08:37 PM The flanges are just held together using clamps 17-Dec-19 08:37 PM The other system is CF, Conflat 17-Dec-19 08:37 PM That's what you see in huge labs with big budgets, and in some more fun hobbyist projects. The system uses a one-time use(or sometimes-more-time-use) copper gasket, which is crushed by a "knife edge"(think saw waveform) on both sides of a seal, with bolts 17-Dec-19 08:37 PM You'll want KF hardware to start with, unless you're rolling in gold and enjoy bolting things together often 17-Dec-19 08:37 PM To give you a reference, here's a system I designed but haven't fully built yet 17-Dec-19 08:37 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Assembly_view3-70E0A.png 17-Dec-19 08:37 PM https://i.spirit.re/Ki4yk.jpg 17-Dec-19 08:37 PM All it is is just fancy pipes held together with clamps. 17-Dec-19 08:37 PM On the bottom I have a turbomolecular pump, which is probably the place you'll want to put yours 17-Dec-19 08:37 PM oh, forgot to mention - a lot of turbomolecular pumps come with ISO flanges, not KF/CF. They're cheap, almost the same as KF, but you can see they're held together with bitey clamps. 17-Dec-19 08:37 PM above the turbopump is a vacuum gate valve, probably not something you'll need to worry about for now(my system will have glass tubes that can shatter, so I need to keep the turbo safe) 17-Dec-19 08:37 PM on the top is a KF50(50mm) to KF16(16mm) adapter, with a few plugs. On the left is a few valves(again not really needed for a basic setup), on the right is a cross that I am using to attach vacuum gauges to. 17-Dec-19 08:37 PM And on the top I'm just going to put whatever experiment I'm working on 17-Dec-19 08:37 PM A simple system you can build is: Forevacuum pump -> (exhaust)[Turbomolecular pump](intake) -> flange adapter -> (one side plugged)[KF tee from your turbo's size to your accessory size(like mine, KF50 to KF16)] -> KF16 cross -> vacuum gauges/gas inlets/whatever -> your project on top, whatever it may be 17-Dec-19 08:37 PM Your main vacuum gauges obviously go on the high vacuum side. A low vacuum(foreline) gauge is nice to have, but can also be ignored if you know your pump is good. 17-Dec-19 08:37 PM As for choosing a turbomolecular pump: 1) Buy one with a controller. I didn't, and it's a painful process to build your own. 2) Buy one that is specified to spin free with no noises. If you can, try to find a pump that's known good, but otherwise just look for one that the seller says spins smoothly with no noises. 17-Dec-19 08:51 PM ooh 17-Dec-19 08:51 PM This infodump applies to everyone that joined and wants to start playing with a vacuum, listening to others' suggestions and advice is also a good idea 17-Dec-19 08:51 PM this is awesome 17-Dec-19 08:52 PM On that note, @Mason_Yu has a nice Edwards pump for $350 in #swap-meet 17-Dec-19 08:52 PM That's a really good price and you should grab it :P 17-Dec-19 08:52 PM Yep, anyone wants it? 17-Dec-19 08:52 PM Samy here might 17-Dec-19 08:53 PM The controller is like $67 from eBay 17-Dec-19 08:53 PM yeah, that's one exception to turbos with no controllers 17-Dec-19 08:53 PM edwards controllers are cheap and available 17-Dec-19 08:53 PM But I have a controller and two pumps, so I can always test it for you before shipping 17-Dec-19 08:54 PM buying one from someone who knows what they're doing is already better than most ebay listings 17-Dec-19 08:54 PM found a cheap controller 17-Dec-19 08:54 PM https://www.ebay.com/itm/Edwards-Turbo-Pump-Controller-EXDC80-D39640000/254354147030? 17-Dec-19 08:54 PM though it's the weird high voltage one 17-Dec-19 08:54 PM here's a 24v one 17-Dec-19 08:54 PM https://www.ebay.com/itm/Edwards-24-VOLT-EXDC80-right-angle-Turbo-Molecular-Pump-Controller-D39645100/254352429177 17-Dec-19 09:01 PM oh cool 17-Dec-19 09:01 PM i might be interested -- want to read up tonight and learn what i may need to get a basic but extendable setup going. i'd like to avoid buying something that i'd need to replace later on with slightly more demanding projects 17-Dec-19 09:03 PM well, the EXT255 he's selling is overkill for a basic setup 17-Dec-19 09:03 PM The turbo should pretty much be perfect for everything 17-Dec-19 09:03 PM its a good pump 17-Dec-19 09:03 PM i'm a fan of overkill 17-Dec-19 09:03 PM 250l/s is also a very good pumping speed 17-Dec-19 09:04 PM You might actually need to choke it off a bit for sputtering 17-Dec-19 09:04 PM very true 17-Dec-19 09:04 PM or just turn it off when doing sputtering 17-Dec-19 09:04 PM Yeah or that 17-Dec-19 09:04 PM Depending on if you care about back streaming. 17-Dec-19 09:05 PM backstreaming of what? 17-Dec-19 09:06 PM Rotary pump oil 17-Dec-19 09:06 PM the turbo itself is a pretty good baffle 17-Dec-19 09:06 PM not to mention the hose 17-Dec-19 09:08 PM Still 17-Dec-19 09:08 PM It will backstream 17-Dec-19 09:09 PM well then, a gate valve might work 17-Dec-19 09:09 PM a manual one, to sit it in the middle 17-Dec-19 09:13 PM thanks all, driving home then will continue investigating. i really appreciate all the info 17-Dec-19 09:13 PM No problem. Im looking forward to seeing what you do with it! 17-Dec-19 09:13 PM feel free to ask if you have any questions 17-Dec-19 09:13 PM look forward to sharing a project 17-Dec-19 10:23 PM Joined the server. 17-Dec-19 10:25 PM Welcome! 17-Dec-19 10:25 PM lots of new people today 17-Dec-19 10:27 PM hi 17-Dec-19 10:27 PM i'm guessing i will need a legit forevacuum pump and the cheap rotary pump will not cut it, but what would be the way to validate that? to simply test with the vacuum gauge to see what it gets to? 17-Dec-19 10:28 PM What kind of cheap pump is it? 17-Dec-19 10:28 PM The harbor freight kind? 17-Dec-19 10:28 PM hi n00n, zakqwy 17-Dec-19 10:28 PM probably less nice 17-Dec-19 10:28 PM let me find link 17-Dec-19 10:28 PM https://www.amazon.com/ZENY-Single-Stage-Economy-Conditioner-Refrigerant/dp/B012CFTYX4 17-Dec-19 10:29 PM Oh, yeah, that's pretty much the worst kind you can get :D 17-Dec-19 10:29 PM haha 17-Dec-19 10:29 PM it's what i've used for years for silicone and food projects 17-Dec-19 10:29 PM I'd look for a Leybold Trivac, such as those I've linked. If you can find one cheap, go for it. 17-Dec-19 10:29 PM Very serviceable and most importantly quiet 17-Dec-19 10:29 PM Plus the oil doesn't cost its weight in kidneys 17-Dec-19 10:30 PM MEOW 17-Dec-19 10:30 PM trivacs are great 17-Dec-19 10:31 PM ahh ok awesome 17-Dec-19 10:31 PM thank you! quiet is important to me 17-Dec-19 10:31 PM you can go pretty far with a dual-stage rotary vane pump of even pretty mediocre quality. single stage may not be enough to comfortably back a high vacuum pump 17-Dec-19 10:31 PM fwiw 17-Dec-19 10:32 PM To be fair those are the worst quality you can get, not just mediocre 17-Dec-19 10:32 PM Think 10-50 mbar ultimate pressure 17-Dec-19 10:32 PM (if that) 17-Dec-19 10:32 PM on a single stage? yeah 17-Dec-19 10:33 PM But the good part about modern turbopumps is that they're happy without sub-mbar backing due to the various integrated draggy-flingy stages at the bottom 17-Dec-19 10:33 PM So you can afford to have a crappier pump, dirtier oil, etc 17-Dec-19 10:36 PM depends on your gas load somewhat too. dunno if i'd run a turbo longterm at over a mbar of backing pressure, idk if diffusion pumps are more forgiving of that 17-Dec-19 10:36 PM Mixed bag with dif pumps 17-Dec-19 10:36 PM Turbos are happy at 1 mbar of backing as long as you don't have a huge gas load 17-Dec-19 10:36 PM Or you can just water cool them 17-Dec-19 10:36 PM yeh 17-Dec-19 10:36 PM but in general you need better backing pressure 17-Dec-19 10:36 PM If you dont want back streaming 17-Dec-19 10:37 PM thanks @Deleted User and @samy !! this is awesome. 17-Dec-19 10:37 PM The consequences are different when it comes down to it. Above critical backing pressure you can kill a turbo. Above critical in a diff pump you backstream 17-Dec-19 10:38 PM Can you really kill it? 17-Dec-19 10:38 PM yes 17-Dec-19 10:38 PM Or just force it to shut down because of overload 17-Dec-19 10:38 PM very much kill it 17-Dec-19 10:38 PM Overheat can lead to some undesirable operation... 17-Dec-19 10:38 PM Well, overheat sort of implies overload 17-Dec-19 10:39 PM It also can lift the rotor if its to high 17-Dec-19 10:39 PM now that would be uncomfortable 17-Dec-19 10:39 PM yeah 17-Dec-19 10:39 PM its not optimal 17-Dec-19 10:45 PM Would it be a good idea to put a cryotrap (-20°C) with silica gel between bad rotary vane pump and turbopump? What would be better than silica gel in this case? 17-Dec-19 10:45 PM it'd be overkill, but yeah, it can work 17-Dec-19 10:45 PM baffles are a good idea 17-Dec-19 10:45 PM one of those KF16 block-looking things you find on some forepumps 17-Dec-19 10:45 PM MIST FILTER, that's what they're called. 17-Dec-19 10:45 PM expensive new though 17-Dec-19 10:46 PM Chinese made these for 50$ 17-Dec-19 10:46 PM For KF25 17-Dec-19 10:47 PM quite ridiculously expensive new, funnily enough 17-Dec-19 10:47 PM Molecular sieve filters are made fore this as well 17-Dec-19 10:47 PM https://www.ebay.com/itm/EMF16-Oil-Mist-Exhaust-Filter-KF25-Ports-Designed-for-Edwards-for-Vacuum-Pumps/392411148791 17-Dec-19 10:47 PM this is the kind you want if your pump is spitty 17-Dec-19 10:47 PM https://www.aliexpress.com/item/4000150501397.html?spm=a2g0o.productlist.0.0.41c852d1k9IEaz&algo_pvid=3f6f0b7e-26a3-4656-8107-fc9f597d33b4&algo_expid=3f6f0b7e-26a3-4656-8107-fc9f597d33b4-2&btsid=271db69d-df87-403e-8986-390681d2560a&ws_ab_test=searchweb0_0,searchweb201602_5,searchweb201603_53 Or that's for exhaust? 17-Dec-19 10:47 PM this is for exhaust 17-Dec-19 10:47 PM the one I linked is for the foreline 17-Dec-19 10:47 PM there's an easy way to muffle your exhaust 17-Dec-19 10:47 PM a toilet paper roll, the kind without a core 17-Dec-19 10:47 PM lets air through, silences the souls vanes blurping in oil 17-Dec-19 10:47 PM I've been meaning to design a toilet paper roll muffler holder to 3d print 17-Dec-19 10:49 PM @Deleted User description of your item looks like it is also for exhaust, not foreline 17-Dec-19 10:49 PM I've seen them used on the foreline 17-Dec-19 10:49 PM actually yeah they're exhaust 17-Dec-19 10:49 PM hm. 17-Dec-19 10:49 PM well, there's an easy way to replicate it, just stuff a KF16 extension with something vacuum compatible 17-Dec-19 10:49 PM better yet, two or three 90 degree angles 17-Dec-19 10:51 PM oh reminds me i need to bake my foreline sieves soon 17-Dec-19 10:51 PM @AdamMcCombs @qualia Which pore size sieves optimal for foreline? 17-Dec-19 10:52 PM i use 13-X, which might be too big tbh, but my trap originally used alumina pellets 17-Dec-19 10:52 PM https://www.mdcvacuum.com/Catalog/US/Foreline-Traps/Foreline_Traps 17-Dec-19 10:52 PM Here's a good page on foreline traps 17-Dec-19 10:53 PM optimal pore size kinda depends on your gas load i think 17-Dec-19 10:53 PM i've never been 100% sure on that; my concern has mostly been rotary vane oil backstreaming prevention 17-Dec-19 10:54 PM On the exhaust side its not just muffling it, you are trying to get the oil vapor to drop out of the air 17-Dec-19 10:54 PM So the exhaust filters are designed to maximize the path it has to take through something that the oil is likely to condense on and can flow out of 17-Dec-19 10:55 PM hence toilet paper rolls 17-Dec-19 10:55 PM dense but permeable 17-Dec-19 10:55 PM You need a longer path 17-Dec-19 10:55 PM I've tested it, and it works really well 17-Dec-19 10:55 PM For it to actually drop heavy oil out 17-Dec-19 10:55 PM you get a super thick cloud of oil inside the doughnut, outside it's practically perfectly clean 17-Dec-19 10:55 PM so I'm happy with that 17-Dec-19 10:56 PM it sounds like it would saturate quickly 17-Dec-19 10:56 PM Oh I see what your saying 17-Dec-19 10:56 PM But yeah im with qualia 17-Dec-19 10:56 PM not every process needs to be super clean in fairness 17-Dec-19 10:57 PM it does saturate slowly 17-Dec-19 10:57 PM but the rolls are 10c a piece 17-Dec-19 10:58 PM Yeah I was going to say but does it matter 17-Dec-19 10:58 PM sure, just replace it each run 17-Dec-19 10:58 PM :D 17-Dec-19 11:07 PM u could enhance TP with hydraulic press 17-Dec-19 11:33 PM Wouldn't the soaked toilet paper be a waste of pump oil? 17-Dec-19 11:33 PM well, you can't really catch it 17-Dec-19 11:33 PM not to mention the amount that sprays out is basically nothing 17-Dec-19 11:36 PM you could centrifuge it out? 17-Dec-19 11:36 PM just the usual weekend, wringing my toilet paper out to get forepump oil 17-Dec-19 11:37 PM :3 18-Dec-19 12:10 AM fomblin's expensive ok 18-Dec-19 12:10 AM fomblin is also not the only oil you can use 18-Dec-19 12:10 AM The kicker is most systems fomblin is used on should probably be vented outside... 18-Dec-19 12:10 AM I mean if you are doing anything nasty you probably want fomblin 18-Dec-19 12:11 AM Isn't fomblin also nasty itself? 18-Dec-19 12:11 AM fomblin's incredibly inert, i thought 18-Dec-19 12:11 AM to people I mean 18-Dec-19 12:12 AM can't you oxygenate it and liquid breathe with it 18-Dec-19 12:12 AM it's in that class of thing iirc 18-Dec-19 12:12 AM that'd be fluorinert 18-Dec-19 12:12 AM Yeah its very very good at not interacting with things 18-Dec-19 12:12 AM perfluorinated polyether 18-Dec-19 12:12 AM yeah fluorine-anything if it's stable generally tends to not have anything to do with the environment 18-Dec-19 12:14 AM Yeah fomblin was what i was thinking too 18-Dec-19 12:14 AM It's in my main rough pump at the moment 18-Dec-19 12:14 AM But anyways there's very good reasons to run fomblin and most of it is don't literally turn the oil into an explosive or dont let the pump corrode 18-Dec-19 12:14 AM or run nitroglycerin as the oil 18-Dec-19 12:15 AM uh 18-Dec-19 12:15 AM it's either a good lubricant or you don't exist anymore 18-Dec-19 12:15 AM Yeah 18-Dec-19 12:15 AM I was going to say 18-Dec-19 12:15 AM apparently fomblin is also used to store brains? for research? 18-Dec-19 12:15 AM not the thing I really want to shove hf or lots of oxygen at 18-Dec-19 12:16 AM http://freesurfer.net/fswiki/Fomblin 18-Dec-19 12:16 AM formaldehyde is also used for storing brains 18-Dec-19 12:16 AM Solution Quantity Price HT200 7kg $707.87 18-Dec-19 12:16 AM oooouch 18-Dec-19 12:16 AM Is that for fomblin? 18-Dec-19 12:16 AM looks like it 18-Dec-19 12:16 AM If so that looks like a good deal 18-Dec-19 12:17 AM haha 18-Dec-19 12:17 AM https://www.ebay.com/itm/SOLVAY-YL-VAC-25-6-FOMBLIN-Perfluoro-Polyether-3kg-remaining-quantity/254437616140 18-Dec-19 12:18 AM lol they're just selling the rest of it 18-Dec-19 12:18 AM why are they saying 3kg then? 18-Dec-19 12:18 AM What's worse is the fomblin grease 18-Dec-19 12:18 AM That stuff is so expensive 18-Dec-19 12:18 AM https://www.ebay.com/itm/Fomblin-Grease/382991721127 18-Dec-19 12:18 AM is it? 18-Dec-19 12:19 AM i assume you basically need to buy your pump brand new and never touched by hydrocarbon oils for this kinda work huh 18-Dec-19 12:19 AM oh 18-Dec-19 12:19 AM Vacuum version 18-Dec-19 12:19 AM 20 grams 18-Dec-19 12:19 AM lol 18-Dec-19 12:19 AM I mean 18-Dec-19 12:19 AM you could rebuild it 18-Dec-19 12:19 AM dunk the entire pump head in acetone or something 18-Dec-19 12:19 AM that sounds like a maddening degreasing procedure 18-Dec-19 12:20 AM kerosene first, ultrasonic bath 18-Dec-19 12:20 AM preferably both at the same time 18-Dec-19 12:20 AM Iv never swapped a pump over from hydrocarbon back to fomblin before 18-Dec-19 12:20 AM then acetone rinse? 18-Dec-19 12:20 AM Brake cleaner works well 18-Dec-19 12:20 AM acetone sounds like it'd eat vanes 18-Dec-19 12:20 AM Not the California version tho 18-Dec-19 12:20 AM depends on the vane type 18-Dec-19 12:20 AM After disassembly 18-Dec-19 12:20 AM cali brake cleaner is awful yeah 18-Dec-19 12:20 AM it's just dilute hexane and acetone 18-Dec-19 12:20 AM iirc 18-Dec-19 12:20 AM But yeah dont run acetone through a rotary pump 18-Dec-19 12:20 AM please 18-Dec-19 12:21 AM isn't non-cali brake cleaner very nasty? 18-Dec-19 12:21 AM yup 18-Dec-19 12:21 AM Yeah but oh so effective 18-Dec-19 12:21 AM but it works really well 18-Dec-19 12:21 AM I don't remember what's in it 18-Dec-19 12:21 AM A lot 18-Dec-19 12:21 AM isn't it TCE? 18-Dec-19 12:21 AM it might be TCE 18-Dec-19 12:21 AM Methylene chloride? 18-Dec-19 12:21 AM MEK? 18-Dec-19 12:21 AM something that turns to phosgene around intense UV 18-Dec-19 12:21 AM anything with "ethyl" in the name is probably in it 18-Dec-19 12:21 AM :D 18-Dec-19 12:21 AM I think all of the aboves 18-Dec-19 12:22 AM can't weld near stuff recently degreased with it 18-Dec-19 12:22 AM I wonder if MEKP is still used 18-Dec-19 12:22 AM I know it's sold as a hardener for epoxies, but it's mixed with stuff that makes it safe-ish 18-Dec-19 12:22 AM pure MEKP is a high explosive 18-Dec-19 12:22 AM This sounds like the start of a CSB video right now 18-Dec-19 12:22 AM CSB? 18-Dec-19 12:23 AM Chemical Safety Board 18-Dec-19 12:23 AM oh lol 18-Dec-19 12:23 AM I watched lead and nickel sit in h2o2 earlier, after a few minutes it was spewing steam/gas 18-Dec-19 12:23 AM i love their videos so very much 18-Dec-19 12:23 AM They produce the awesome incident analysis videos 18-Dec-19 12:23 AM And like have of them are someone did something wrong with MEK or phosgene 18-Dec-19 12:27 AM the confined spaces ones have given me renewed respect for urban exploration 18-Dec-19 12:27 AM Oh yeah confine spaces ones are informative as well 18-Dec-19 12:46 AM Ugh speaking of fomblin I have to go spend like 300$ on grease soon 18-Dec-19 12:46 AM Normally I get my grease free when I de install a lab or something but I'm running low... 18-Dec-19 01:03 AM What are the benefits of using Fomblin in rotary vane? Lower vapor pressure and more inert? 18-Dec-19 01:03 AM It's not really more inert pretty much just inert 18-Dec-19 01:03 AM In most cases 18-Dec-19 01:03 AM It's a slightly worse vapor pressure 18-Dec-19 01:05 AM if you need to pump high oxygen concentrations, or really aggressive chemicals from semiconductor/plasma processing 18-Dec-19 01:05 AM probably other stuff 18-Dec-19 01:05 AM If you pump corrosive gasses with regular oil you will destroy the pump 18-Dec-19 01:05 AM If you pump oxogen gas with a regular pump and hydrocarbon oil you turn it into a bomb 18-Dec-19 01:07 AM wonder the pumps can get sufficient lube with fluorinert 18-Dec-19 01:07 AM that stuff is comparatively cheap 18-Dec-19 01:09 AM lol 18-Dec-19 02:44 AM I find some vacuum grease that use for Plasma. I could use it for e-beam ? Is that make problems 18-Dec-19 04:44 AM Joined the server. 18-Dec-19 10:18 AM @ahmadalinia do not use vacuum grease. 18-Dec-19 10:18 AM If you need it, something is wrong. 18-Dec-19 10:19 AM But it’s really expensive free silicone vacuum grease. What you suggest 18-Dec-19 10:21 AM Not using it 18-Dec-19 10:21 AM At all 18-Dec-19 10:21 AM You don't need grease. 18-Dec-19 10:59 AM e beam requires quite high vacuum levels. plasma processing happens at much lower pressures since plasma definitionally requires some kind of gas backfill 18-Dec-19 10:59 AM at e-beam vacuum levels, vacuum grease is a dire contaminant 18-Dec-19 10:59 AM Yeah I agree, if your system is well sealed, no need for it 18-Dec-19 11:00 AM there are very few cases where a vacuum grease is explicitly required (bell jars and glassware come to mind) 18-Dec-19 11:00 AM It gets everywhere and is a mess to clean 18-Dec-19 11:00 AM that said, free stuff is nice.. just know where to use it 18-Dec-19 11:00 AM i use vacuum grease as an NPT thread sealant on some roughing-side hardware to pretty good effect 18-Dec-19 11:02 AM In an ebeam system the only place I use grease is where the o-ring experiences motion, either during assembly or use. 18-Dec-19 11:02 AM it is also nice for slicking up stainlesa steel bolts used on external mounting tapped flanges so they don't gall up under baking cycles, though this may be wasteful depending on the fanciness of your grease 18-Dec-19 11:02 AM (note that this refers to parts that are outside the vacuum) 18-Dec-19 11:02 AM dc-150 is nice for that ^ 18-Dec-19 11:05 AM On an ebeam system I wouldn't get silicone even close to it 18-Dec-19 11:05 AM mm fair 18-Dec-19 11:05 AM silvered bolts for days then :D 18-Dec-19 01:16 PM Joined the server. 18-Dec-19 01:18 PM Yay, welcome! 18-Dec-19 01:27 PM @AdamMcCombs I want to use vacuum grease just for Oring not in other place . Another thing i notice is about another grease maybe useful. Like PFPE and PTFE grease. I read Manuel they’re really high outgassing material. 18-Dec-19 01:27 PM Thanks! Glad to be here 18-Dec-19 01:28 PM Your welcome 18-Dec-19 01:33 PM @ahmadalinia did you check ebay for non silicone grease? 18-Dec-19 01:34 PM you don't need grease 18-Dec-19 01:34 PM @nmz787 18-Dec-19 01:34 PM Yes but it’s really expensive for myself I must spend my money on other things 18-Dec-19 01:35 PM needing grease is like needing duct tape... 18-Dec-19 01:35 PM also, greasing your viton orings in the high vacuum section is a really stupid idea 18-Dec-19 01:35 PM especially for ebeam 18-Dec-19 01:35 PM if you need duct tape its because something is WRONG 18-Dec-19 01:35 PM yes 18-Dec-19 01:35 PM If you really need it though, you don't use much, will probably last a decade or more 18-Dec-19 01:36 PM The key word here is "really need it " 18-Dec-19 01:36 PM Saying you don't need it is kinda stupid, he could have a huge chunk missing from somewhere and the grease may fix it faster than re-machining 18-Dec-19 01:36 PM If he had grease at this point, he might be past his vacuum issue and onto further system development 18-Dec-19 01:37 PM I mean... this may be true but if it destroys the use of the machine he is trying to build... then what is the point? 18-Dec-19 01:37 PM AKA ebeam 18-Dec-19 01:37 PM except for e-beam grease is even worse 18-Dec-19 01:38 PM if its just like sputtering or something yea its fine 18-Dec-19 01:38 PM in a working e-beam machine grease is bad 18-Dec-19 01:38 PM Or he'd have the first have experience, which is always more convincing that second hand 18-Dec-19 01:38 PM There's no problem with grease and ebeam 18-Dec-19 01:38 PM but yea, just I'd say before grease first off figure out where you need it 18-Dec-19 01:38 PM Just get 10-6 or 10-9 grease 18-Dec-19 01:38 PM inspect all sealing surfaces very closely 18-Dec-19 01:38 PM I think the problem is charging? not outgassing? 18-Dec-19 01:39 PM yes 18-Dec-19 01:39 PM but let's not forget that he hasn't been able to get any high vacuum going 18-Dec-19 01:39 PM he's not having leak issues, his entire system is leaky 18-Dec-19 01:39 PM Well there's not much sealing surface/joints in the beam path 18-Dec-19 01:39 PM fixing huge leaks with grease is like taping a car together with electrical tape 18-Dec-19 01:39 PM will it work? maybe, for a short while 18-Dec-19 01:40 PM Lol I've done it 18-Dec-19 01:40 PM but yea again, with grease you should at-least figure out where you need it 18-Dec-19 01:40 PM Well, metal tape anyway 18-Dec-19 01:40 PM don't just want to fill all joints with grease... 18-Dec-19 01:40 PM just figure out which ones have nicks or problems and use it there... 18-Dec-19 01:40 PM and it shouldn't need much 18-Dec-19 01:40 PM not to mention grease is used to seal up tiny cracks 18-Dec-19 01:40 PM not huge leaks 18-Dec-19 01:40 PM it's closer to thermal paste in function than to silicone 18-Dec-19 01:41 PM I solve problem yesterday I forgot to told you it because of pump sealing . I get to final pressure of pump mean 0.15 torr 18-Dec-19 01:41 PM Wait you can't make a vacuum chamber out of a grease bubble??? 18-Dec-19 01:41 PM 150mtorr is a foreline pressure 18-Dec-19 01:41 PM not high vacuum 18-Dec-19 01:41 PM Which is what he was debugging 18-Dec-19 01:42 PM so the next step is to make sure the entire chamber stays at that pressure 18-Dec-19 01:42 PM and doesn't leak 18-Dec-19 01:42 PM He was getting like 20 torr before 18-Dec-19 01:44 PM I don’t have pictures to show you but by changing vacuum pumps clamp yesterday I get 150micron tomorrow I will use another pump that I have to get 15micron after that diffusion pump starting 18-Dec-19 01:45 PM You don't have silicone oil in it, right? 18-Dec-19 01:45 PM Yes 18-Dec-19 01:45 PM Without diffusion pump oil 18-Dec-19 01:45 PM But for high vacuum I need to use silicone oil 18-Dec-19 01:46 PM Not for ebeam 18-Dec-19 01:46 PM silicone oil is worse than regular diffpump oil afaik 18-Dec-19 01:46 PM and yeah silicone oil is incompatible with ebeam 18-Dec-19 01:47 PM Any backstreamed oil into the beam path will turn to glass 18-Dec-19 01:47 PM Thus charging, and deflecting the beam 18-Dec-19 01:48 PM Don’t worry about oil . Oil evaporat can not go to e-beam column 18-Dec-19 01:48 PM yes, yes it can 18-Dec-19 01:48 PM Lol 18-Dec-19 01:48 PM Definitely can 18-Dec-19 01:48 PM and it will 18-Dec-19 01:48 PM My whole column was coated in oil when it got taken apart 18-Dec-19 01:48 PM Big droplets 18-Dec-19 01:52 PM Looking it when oil evaporat just go up don’t go side maybe it’s need more time for vacuum but it will have less effect on mean chamber 18-Dec-19 01:52 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-9E258.jpg 18-Dec-19 01:53 PM It will be in vapor phase 18-Dec-19 01:53 PM It will diffuse, as gasses do 18-Dec-19 01:53 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-A148E.jpg 18-Dec-19 01:53 PM @nmz787 i know but have less er effect on system 18-Dec-19 01:54 PM No, it will go everywhere. 18-Dec-19 01:54 PM I too have similar setup, as well as a chiller baffle between pump and upper pipes 18-Dec-19 01:54 PM The oil was coating my electron gun 18-Dec-19 01:54 PM @ahmadalinia just means lesser charging, but it's still charging, and will still ruin you imaging and beam quality a lot 18-Dec-19 01:55 PM You have experience I hope this problem not happened for my system 18-Dec-19 01:55 PM It will 18-Dec-19 01:55 PM Everyone is telling you that you will have issues 18-Dec-19 01:55 PM You should probably listen to... everyone 18-Dec-19 01:55 PM It mean to have turbo pump . Damm to money 18-Dec-19 01:55 PM You really great why I find you so late 18-Dec-19 02:08 PM Better late than never. 18-Dec-19 02:12 PM No pain no gain 18-Dec-19 03:44 PM https://www.youtube.com/watch?v=v1vXC-vKgKg 18-Dec-19 04:51 PM From the junk collection, I think this is a high power laser beam dump, or power meter 18-Dec-19 04:51 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-3DCC1.jpg 18-Dec-19 04:51 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image1-6ECE5.jpg 18-Dec-19 04:51 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image2-7BC16.jpg 18-Dec-19 04:51 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image3-ED285.jpg 18-Dec-19 04:52 PM water cooled laser power meter 18-Dec-19 04:52 PM the head of one 18-Dec-19 04:52 PM Basically just a water cooled big Cu slug 18-Dec-19 04:52 PM I’m thinking maybe put magnets inside and replace the water tubes with glass or alumina or something, maybe I can make it a sputter gun 18-Dec-19 04:53 PM no point 18-Dec-19 04:53 PM best to clean it up and keep it as is 18-Dec-19 04:54 PM What’s the electrical readout from it, just a thermistor? 18-Dec-19 04:54 PM usually a thermocouple or a thermoelectric element 18-Dec-19 06:24 PM I would like to build a basic sputter source though 18-Dec-19 06:24 PM Any good DIY examples out there? 18-Dec-19 06:25 PM Applied Science has a good magnetron sputterer build 18-Dec-19 06:25 PM But if you want the barebone cheapest option there's also a lot of Youtube videos on DC magnetrons built with microwave oven transformers, a magnet, a spark plug and a mason jar 18-Dec-19 06:25 PM https://www.youtube.com/watch?v=Cyu7etM-0Ko 18-Dec-19 06:25 PM I'm sure you can adapt this into something less ghetto and sketchy 18-Dec-19 06:33 PM ^ I’m trying to design my DC sputter gun rn 18-Dec-19 06:33 PM My initial build attempt was a pickle jar sputter chamber but I wanted to step it up so trying to build something that’ll work well for this bell jar setup 18-Dec-19 06:42 PM do you guys think the Leybold Trivac D2.5E vacuums are easy to fix if there's some common issue with a used one? 18-Dec-19 06:42 PM They are 18-Dec-19 06:42 PM but if it runs, "fixing" generally doesn't extend beyond rebuilding it and pouring some new oil in 18-Dec-19 06:43 PM I see, one person I'm talking to about one (selling for parts) stated "We tested several all at once. Most had one issue or another so instead of investing time to fix them all we listed for parts not working" -- of course "issue" is vague 18-Dec-19 06:43 PM Don't buy one that's for parts 18-Dec-19 06:43 PM Best to buy one that's tested and known working 18-Dec-19 06:44 PM got it 18-Dec-19 06:51 PM only reason to go for ones that arent guaranteed is if you are really tight on money or enjoy deal hunting 18-Dec-19 06:51 PM and enjoy repairing things 18-Dec-19 06:51 PM i got two D2.5Es for $70 and it worked out really well for me 18-Dec-19 06:51 PM easily could have been sticking them on eBay to recoup my money 18-Dec-19 06:51 PM if you keep reminding me of this deal I might nick one in the middle of the night 18-Dec-19 06:52 PM haha well i did have to go pick them up in Arizona but i was visiting someone anyway 18-Dec-19 06:52 PM seller wouldn't ship 18-Dec-19 07:09 PM and the ones I'm seeing are 230V (I'm in US) but looks like still 60Hz so will need to step up or connect two circuits...shouldn't be an issue though 18-Dec-19 07:18 PM you should be looking for US ones 18-Dec-19 07:18 PM they're HEAVY 18-Dec-19 07:23 PM bit cheaper to get a 230V 60Hz one...i assume there wouldn't be an issue? 18-Dec-19 07:23 PM odd that i'm looking at two identical ones, same model number, but one has 2*10^-3mbar listed and the other has 5*10^-4mbar listed on the units themselves 18-Dec-19 07:29 PM It can be a bit confusing to read vacuum 18-Dec-19 07:29 PM But lower is always better 18-Dec-19 07:31 PM there are two types of the 230V motors on the D2.5E. i think there is one that is just the 50hz model and one that does 50 and 60hz at 220/230V 18-Dec-19 07:31 PM lucky i have 220 circuits available but ive heard they run just fine on step up transformers 18-Dec-19 07:33 PM yeah i can't see what would be different as they support 60Hz as long as there's power avail, and worst case I can pull the 220 before it gets split on the bus bars 18-Dec-19 07:45 PM for KF16 clamps, is aluminum fine or will i want stainless steel? 18-Dec-19 07:48 PM Alu is fine 18-Dec-19 07:58 PM cool 18-Dec-19 08:22 PM Note that theres stuff specced for 208v, 220v, 230v, 240v 18-Dec-19 08:22 PM And you probably can just use a buck or boost transformer configuration, not step up/down 18-Dec-19 08:23 PM they're ac motors 18-Dec-19 08:23 PM Gonna be much lighter and cheaper 18-Dec-19 08:23 PM Yeah 18-Dec-19 08:23 PM boost with an ac motor? 18-Dec-19 08:24 PM http://sound.whsites.net/articles/buck-xfmr.htm 18-Dec-19 08:25 PM oh 18-Dec-19 08:25 PM similar to a variac 18-Dec-19 08:25 PM Well, no variation though with a knob 18-Dec-19 08:30 PM fixed tap autotransformer 18-Dec-19 08:34 PM you need way less VA than if you were speccing a variac 18-Dec-19 08:34 PM Since you only need to account for the amps * (difference of volts between input and output) 18-Dec-19 08:34 PM @samy also put a meter to your power outlet, my "220" plug actually gives 240 18-Dec-19 09:11 PM @nmz787 ahh will do, thanks 18-Dec-19 10:23 PM Grid power is typically only assured to about 10% accuracy I think 18-Dec-19 10:23 PM So you’ve got the 110-120V “band” and the 220-240V “band” 18-Dec-19 10:23 PM Rare that devices are more fussy than that 18-Dec-19 10:23 PM If the device is really sensitive then you need to measure for your local area and adjust the transformer tap 18-Dec-19 10:23 PM But even then it may change if local grid demand changes. 18-Dec-19 10:44 PM ahh 19-Dec-19 10:50 AM https://www.engadget.com/2019/12/18/ibm-research-ev-battery-cobalt-free/ 19-Dec-19 10:50 AM I need to find a way to go work for IBM's Research center... 19-Dec-19 10:50 AM They are doing some neat stuff 19-Dec-19 11:08 AM lol wonder what theyre using as cathode materials if not using cobalt/nickel 19-Dec-19 11:08 AM especially if it’s from sea water, which is mainly just alkali and alkali earth metals 19-Dec-19 11:08 AM assuming magnesium stuffs I don’t know enough about batteries tho 19-Dec-19 11:30 AM Today vacuum get to 30 micron or better say 0..0304 torr . Pump ultimate pressure is 15 micron . Iuse vacuum grease in this issue is compulsive. I guess it have small leakage but where is ??? It’s need some helium gas tank to testing . By the way how much is backing vacuum pressure for diffusion pump ? 20micron is enough or lesser 19-Dec-19 11:32 AM Helium for leak testing won't do you any good without a helium detector 19-Dec-19 11:33 AM @ahmadalinia nobody is going to help you if you keep insisting you know better 19-Dec-19 11:33 AM seriously, you do not need grease 19-Dec-19 11:33 AM @GigaSquirrel helium is nice for testing without a leak detector too 19-Dec-19 11:34 AM Okay even if I use free silicone grease? 19-Dec-19 11:34 AM NO. 19-Dec-19 11:34 AM You should fix the issues you have, not patch them up with grease 19-Dec-19 11:35 AM I've had way more success with ipa / break cleaner for leak testing without a specialized detector 19-Dec-19 11:35 AM depends on the size of the leak you have 19-Dec-19 11:35 AM Adam talked about it yesterday 19-Dec-19 11:36 AM ipa / Break cleaner?? 19-Dec-19 11:36 AM alcohol 19-Dec-19 11:36 AM don't worry about brake cleaner 19-Dec-19 11:40 AM I use alcohol for but it is not good as thinner. It’s really great Beton the of Kf flang I use alcohol but nothing show on gauge when I use thinner something show on gauge . I suggest to use thinner for leakage detector thinner10000 19-Dec-19 11:41 AM It may destroy your gaskets 19-Dec-19 11:42 AM Yes off course but thinner10000 is okay for gaskets. 19-Dec-19 11:42 AM Is it? 19-Dec-19 11:42 AM Are you sure? 19-Dec-19 11:44 AM I ask some of supplier he say don’t worry about it . But personally i am not sure 19-Dec-19 11:44 AM Your supplier probably doesn't know much about it either 19-Dec-19 11:44 AM First thing he say is not use upper thinner20000 19-Dec-19 11:45 AM Both of these mean nothing to most people 19-Dec-19 11:46 AM But it’s help me to detect two of leakage places . I am just give you my experience 19-Dec-19 11:46 AM Be thoughtful of what you do 19-Dec-19 11:46 AM Remember that if you get a leak in the future, you might have it because of dying seals 19-Dec-19 11:47 AM Yes completely sure 19-Dec-19 12:20 PM I've never heard of thinner 10000 or 20000 19-Dec-19 12:20 PM Seems too high of number for molecular weights, since we're talking solvents 19-Dec-19 01:14 PM It’s mean solvent . Bigger number better solvent @nmz787 How much is back vacuum pressure diffusion pump need ? 19-Dec-19 01:15 PM Not sure, Google it 19-Dec-19 01:15 PM You're probably fine is my guess 19-Dec-19 01:17 PM I find 20micron is okay but want to sure about this issue. 19-Dec-19 01:18 PM an oildiff is impossible too kill, play around a bit 19-Dec-19 01:19 PM You mean it maybe flow to roughing pump ? 19-Dec-19 01:53 PM Things have to go very wrong for the roughing pump to start drinking the diffpump oil 20-Dec-19 12:49 AM gulp 20-Dec-19 05:58 AM People, the thinkpad in the end is a no go to USA, so anyone in europe wants it? 20-Dec-19 05:58 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/EMFjPYwXYAATAyF-32F5B.png 20-Dec-19 07:40 AM What's the model-no and what'd you want in return? 20-Dec-19 08:10 AM He just wants shipping, its a 365XD, shipping to the States is a bit high for my taste and I have 3 of them already. 20-Dec-19 09:20 AM Not quite the 51nb thinkpad... 20-Dec-19 10:19 AM "For example, mineral oil may be removed by Simple Green, a concentrated industrial strength cleaner containing butyl cellosolve." 20-Dec-19 11:25 AM Can it run Crysis tho? 20-Dec-19 11:50 AM It can have a mid-life crisis... 20-Dec-19 11:50 AM XDDDD 20-Dec-19 06:17 PM Joined the server. 20-Dec-19 06:18 PM Welcome! 20-Dec-19 06:22 PM Welcome @dstar, this is Nick. 20-Dec-19 06:23 PM Thanks! 20-Dec-19 09:20 PM <𝔗𝔥𝔞𝔫𝔞𝔱𝔬𝔰#5481> Joined the server. 20-Dec-19 09:25 PM Hello! 20-Dec-19 09:28 PM <𝔗𝔥𝔞𝔫𝔞𝔱𝔬𝔰#5481> Hello 20-Dec-19 10:48 PM Joined the server. 20-Dec-19 11:52 PM Still the twitterverse joining? 21-Dec-19 12:10 AM Believe it or not no 21-Dec-19 12:10 AM The influence is spreading 21-Dec-19 12:10 AM It is indeed 21-Dec-19 02:19 AM Are you able to track joins by invite link? Never have looked at what kind of analytics Discord may provide. 21-Dec-19 09:48 AM How much oil need for 4” diameter diffusion pump ? 21-Dec-19 09:55 AM if you know the model of the pump look up a datasheet if you can find it... 21-Dec-19 09:55 AM I don't think it needs to be PERFECTLY EXACT. but if you can find specs its best... 21-Dec-19 11:12 AM My EXT255H during slowdown, at lowish RPM (<10000 RPM) there is a range of RPM where pump starts vibrating significantly and makes vibrating noise... Some sort of mechanical resonance... Is this normal? Should one try to pass this RPM range as fast as possible or due to low RPM it is not very dangerous? 21-Dec-19 11:13 AM It's pretty normal, don't operate it in that RPM range for long though 21-Dec-19 11:25 AM That region is fine if you just let it accelerate and decelerate normally 21-Dec-19 11:25 AM As long as you don't force it to sit there 21-Dec-19 11:25 AM I still wonder why so few controllers do active braking 21-Dec-19 11:56 AM I guess they don't see where to dump all this energy. You'd want to dump some 200-500W... Without active cooling that's hot, with active cooling - you depend on fan reliability... 21-Dec-19 11:56 AM But it might be a cool project to hack existing controller with external e-brake 21-Dec-19 12:39 PM You're pumping energy in to start it, and that generates heat 21-Dec-19 12:39 PM So just pump the same energy in 90/120 degrees behind, not in front 21-Dec-19 01:29 PM afternoon! 21-Dec-19 01:34 PM @Conmega i don’t find any datasheet . It’s some no name diffusion pump . But former user say he use 30 to 40 mL . But I am not sure I want to became sure about it . 21-Dec-19 01:35 PM that sounds about right for a small diff 21-Dec-19 01:36 PM I guess too because I read 4 inch diameter varain and Edward datasheet. they use 40 to 80 mL oil 21-Dec-19 01:41 PM Joined the server. 21-Dec-19 01:42 PM Welcome! 21-Dec-19 11:34 PM Random rant: the “globally harmonised system” for chemical safety symbols is so stupid and meaningless! Didn’t we already have a perfectly good UN-standard system for chemical hazard labelling? 22-Dec-19 12:06 AM do you have examples? 22-Dec-19 06:10 PM https://youtu.be/K_N_h_mKf-4 22-Dec-19 06:10 PM Suddenly, the price of graphite goes up. 22-Dec-19 06:11 PM I didn't know you can pump air through a thick piece of graphite like that 22-Dec-19 06:14 PM Neither did I! 22-Dec-19 06:22 PM I have an idea... Ultra high speed spindles? 22-Dec-19 06:22 PM Seems like this would be enough for PCB milling 22-Dec-19 06:26 PM Yeah, with the method he described at the end there 22-Dec-19 06:26 PM Only concern would be the ability to take lateral loads and vibrations 22-Dec-19 06:26 PM Once it touches at high RPM the graphite would turn to dust, literally 22-Dec-19 06:26 PM And for drilling it will need to take thrust loads 22-Dec-19 06:28 PM If the bearing is enclosed radially, and very tight tolerance, I reckon you could stuff a huge pressure into it 22-Dec-19 06:28 PM One contact it would be gone 22-Dec-19 06:28 PM Needs testing 22-Dec-19 06:28 PM I might try combining it with a magnetic linear motor when I build one 22-Dec-19 06:33 PM You would have to avoid inducing current in the graphite due to the coils. Perhaps place the bearing blocks at the end of the moving motor and coils in the middle, pressurizing the entire cavity 22-Dec-19 06:33 PM Yup 22-Dec-19 06:33 PM Or just cut up the bearing into three 22-Dec-19 06:35 PM Hmm I need a compressor 22-Dec-19 06:35 PM if only it wasn't expensive to ship from China 22-Dec-19 06:36 PM I'd get one of the California air ones 22-Dec-19 06:36 PM They have some nice and affordable oil-less quiet compressors 22-Dec-19 06:36 PM $59.95.... + $249.95 shipping 22-Dec-19 06:38 PM https://www.ebay.com/itm/CALIFORNIA-AIR-TOOLS-5510A-Ultra-Quiet-Oil-Free-Air-Compressor/303274307157?hash=item469c8eae55:g:qdwAAOSw2gxY0VPF 22-Dec-19 06:38 PM Reasonable price and performance, but I can't afford it atm 22-Dec-19 06:38 PM Yeah, it's the same thing, except with a different sticker on it 22-Dec-19 06:45 PM That graphite has a grain orientation that favors porosity in a given direction 22-Dec-19 06:46 PM So, is it possible to make a radial bearing with it then? I guess if it's two blocks and you have pressure from each side it should still work right? 22-Dec-19 06:46 PM I've got some out in the shop, will take a pic up close here in a bit 22-Dec-19 06:46 PM It should. You should do 3 at 120* offset or similar 22-Dec-19 06:47 PM yeah that's what I was thinking - a radial bearing 22-Dec-19 06:47 PM just enclose the other 2 sides with a cavity 22-Dec-19 06:48 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20191222_204800-51B1E.jpg 22-Dec-19 06:48 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20191222_204813-BD5F0.jpg 22-Dec-19 06:48 PM Not sure if you can make out the grain there or not 22-Dec-19 06:49 PM https://i.spirit.re/fxYQa.png 22-Dec-19 06:49 PM the hatched part would be epoxy 22-Dec-19 06:49 PM or something 22-Dec-19 06:49 PM imagine that but as a ring 22-Dec-19 06:50 PM These are edm electrodes just like that video talks about. I've also used aquarium air stones but these are way easier to shape. 22-Dec-19 06:50 PM you could also extend the shaft inward 22-Dec-19 06:50 PM https://i.spirit.re/k6QA2.png 22-Dec-19 06:50 PM like this 22-Dec-19 06:51 PM It could provide some thrust loading capacity but a slight tilt in the shaft could cause contact much sooner with a large disk like that 22-Dec-19 06:51 PM Well I guess it does depend on axial/radial air film thickness 22-Dec-19 06:52 PM https://youtu.be/vIGnWOuzk6Y 22-Dec-19 06:54 PM And for small bearings, use helium instead of air? 22-Dec-19 06:54 PM Super expensive but it would be more permeable 22-Dec-19 06:54 PM air is more than enough 22-Dec-19 06:58 PM It really doesn't take much air. But you do want to be certain it's clean and dry air. 22-Dec-19 07:52 PM the idea discussed at the end of the applied science video has me a bit confused... 22-Dec-19 07:52 PM why would you ever want to make a fully enclosed bearing like that instead of the 120 degrees apart (so 3) or 4 of them at 90 apart 22-Dec-19 07:53 PM Even support 22-Dec-19 07:53 PM Think journal bearing 22-Dec-19 07:55 PM https://www.youtube.com/watch?v=lOTWx69mghM 22-Dec-19 07:55 PM something like that makes more sense to me 22-Dec-19 07:55 PM way less runout than trying to get a nice smooth precision hole in graphite by hand if you just dial things in after assembly 22-Dec-19 07:58 PM I think Applied Science's point was more along the lines that you can make the graphite air bearing by hand, so it's much more suitable for hobbyists/home experiments, instead of what you show in the video there 22-Dec-19 07:59 PM 3 3d printed air bearings from his video and a 3d printed frame...away you go 22-Dec-19 07:59 PM Away you go 22-Dec-19 07:59 PM Being completely out of spec 22-Dec-19 07:59 PM Those four bearings must be aligned VERY well 22-Dec-19 08:02 PM just saying...probably similar (or better) performance to trying to get a perfect through hole the right size in a solid graphite block by hand 22-Dec-19 08:04 PM There is also the potential of inconsistencies in the home-made blocks. One piece of graphite might not flow like the next and you could develop differential pressures on two sides of the shaft 22-Dec-19 08:04 PM Or worse induce vibrations 22-Dec-19 08:06 PM wouldn't that still be an issue with the through hole idea from the video if the graphite had more and less porous spots? 22-Dec-19 08:06 PM i was surprised he did not seem to have any issues with his mix of amazon graphite 22-Dec-19 08:09 PM Yeah, and it depends on the grain structure as well, definetely not something I'd want supporting a high speed spindle for example. Indeed for a practical application I think 3 or 4 bearing blocks is a better solution and provides more flexibility for dialing things in. 22-Dec-19 08:09 PM But there're more challenges than conventional air bearings. Like the complete inability to withstand a crash/slight contact for example 22-Dec-19 08:10 PM if it was not an issue to split the block and then clamp the two pieces onto a bar for the final surfacing that might work for his idea 22-Dec-19 08:10 PM wonder if that would impact the airflow much 22-Dec-19 08:11 PM You'd still need separate chambers for different blocks and a method to finely adjust them 22-Dec-19 08:18 PM FWIW they tend to self adjust when using a segmented radial situation 22-Dec-19 08:18 PM A full 360 bore type arrangement is much more finicky 22-Dec-19 08:19 PM How? When all the bearing blocks are rigidly mounted? 22-Dec-19 08:20 PM They aren't rigidly mounted usually. And the air cushion compresses so you wind up with more flow on one and more compression on another which balances out 22-Dec-19 08:20 PM We may be talking about different scales of adjustment 22-Dec-19 08:20 PM It won't take up a few hundred microns or a few degrees of misalignment 22-Dec-19 08:20 PM You generally have a flexure sort of mounting arrangement like that video above 22-Dec-19 08:20 PM The angular misalignment can be compensated for using a spherical style mount/interface but the bearing surface itself does need to be straight/flat 22-Dec-19 08:31 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-7361D.png 22-Dec-19 08:31 PM They do propose using the porous media itself as a plain bearing if the air bearing should fail 22-Dec-19 08:31 PM Also I'm really surpised how stiff preloaded air bearings can be 22-Dec-19 08:48 PM It looks like it's possible to use preload force as an adjustment. but that's on a very fine scale and it assumes you have perfectly even identical bearing blocks 23-Dec-19 12:02 PM Does anyone can tell me how to calculate pump speed in this example: turbopump has 500l/sec pump speed, but I connect it to chamber via 300mm KF25 steel bellow. What would be the speed through the bellow? The same interesting for KF50. 23-Dec-19 12:03 PM https://vacaero.com/information-resources/vacuum-pump-technology-education-and-training/1025-conductance-in-vacuum-pumping-systems.html 23-Dec-19 12:03 PM You can either go through this way and calculate conductance of your whole system, or do a molecular flow simulation 23-Dec-19 12:03 PM For molecular flow simulation, I recommend Molflow from CERN 23-Dec-19 12:03 PM https://molflow.web.cern.ch/content/molflow-downloads 23-Dec-19 12:03 PM Assuming you have accurate CAD of everything and models the outgassing rates of your components and surfaces well, simulation is the way to go 23-Dec-19 12:06 PM Thanks for so detailed answer ! 23-Dec-19 12:30 PM Is an aluminum baseplate fine for a bell-jar base? 23-Dec-19 12:30 PM Yes. 23-Dec-19 12:30 PM Just make sure it's thick enough to not bend or break the seal 23-Dec-19 12:30 PM And that it's clean enough 23-Dec-19 12:31 PM I was thinking 1/2” so I could thread my npt adaptor all the way through 23-Dec-19 12:31 PM which I would imagine would be plenty thick not to bend under vacuum 23-Dec-19 12:31 PM If it’s only a 6” ID bell jar 23-Dec-19 12:32 PM that's plenty thick, go for it 23-Dec-19 01:31 PM Would you say that pumping 1L chamber via KF25 to high vacuum (1E-5/1E-6 mbar) is a bad idea? 23-Dec-19 01:42 PM Yeah 23-Dec-19 01:42 PM I'd make the largest possible connection 23-Dec-19 01:42 PM With your EXT255 it makes sense to just... connect it directly 23-Dec-19 03:59 PM Only 1L? I mean you couldn't deal with massive gas load obviously. But you could totally get to those pressures like that so long as it's not a lonnggg path off the kf25. If it's short it's probably not too bad. 23-Dec-19 03:59 PM I've seen smaller paths in SEMs and such. 23-Dec-19 04:06 PM Sure, it'll work, just slowly 23-Dec-19 04:06 PM Shame to not utilize the full pumping speed 23-Dec-19 04:16 PM You can estimate the pumping speed fairly easy if you want to get an idea for speed reduction 24-Dec-19 12:25 AM Good morning everyone, and merry christmas! 24-Dec-19 12:34 AM Good morning to some, and merry christmas to those who have faith! 24-Dec-19 12:48 AM Merry Christmas! 24-Dec-19 05:31 AM moin 24-Dec-19 05:32 AM Moinmoin! 24-Dec-19 05:32 AM Anybody did anything fun for solstice? 24-Dec-19 05:40 AM Filled an empty dog-poop bag with helium and made it almost neutrally buoyant. 24-Dec-19 05:40 AM XDDDD 24-Dec-19 05:40 AM Sweet? Didn't need much helium, did it 24-Dec-19 05:40 AM inner kid giggle 24-Dec-19 05:40 AM nah, just a flash fill. 24-Dec-19 05:40 AM It lasted about 2h. 24-Dec-19 05:43 AM What about filling a bag with air and modifying the external atmosphere composition 24-Dec-19 05:43 AM briefly looks at periodic table, retracts suggestion 24-Dec-19 05:45 AM https://www.youtube.com/watch?v=oabHIAglZIw 24-Dec-19 05:45 AM That might be complicated to do... 24-Dec-19 05:45 AM (and yes, it's a vertical video because the thing went up and down more than sideways) 24-Dec-19 05:45 AM Leonahoy a las 14:43 What about filling a bag with air and modifying the external atmosphere composition briefly looks at periodic table, retracts suggestion 24-Dec-19 05:45 AM That reminds me, how structurally sound is aerogel? 24-Dec-19 05:45 AM Like, could we do vacuum on it, seal the surface, and make it float? 24-Dec-19 05:48 AM Just pump the poopbag to a vacuum 24-Dec-19 05:49 AM Tried, did not go well...should have tried with an unused bag. 24-Dec-19 05:52 AM The bag in the video has like 3l of volume? Do you know the weight of the plastic? 24-Dec-19 10:26 AM Joined the server. 24-Dec-19 10:54 AM Thanks for all help today I get to 1e-5 torr God bless all of young scientists 24-Dec-19 10:54 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-D9A14.jpg 24-Dec-19 11:02 AM Awesome! Congratulations! Great to see you are pulling high vacuum after all that work so far! 24-Dec-19 11:36 AM woot! 24-Dec-19 12:07 PM Congratulations! 24-Dec-19 12:07 PM But 1e-5 is also the bottom limit of that gauge @ahmadalinia 24-Dec-19 12:07 PM You might be below -5 :P 24-Dec-19 12:44 PM Yes of course but it’s enough . I guess diffusion pump can give 10e-8 torr 24-Dec-19 12:44 PM @Deleted User 24-Dec-19 12:46 PM If -5 is enough then that's good 24-Dec-19 12:46 PM Otherwise you might want an ion or penning gauge 24-Dec-19 01:09 PM What's a gauge, maybe similar in range to mks 901p, but which works in rough environments like etch or reactive plasma? 24-Dec-19 01:09 PM Or maybe i Don't need the same range, just something in the middle of the 901p's range? Like 0.1mTorr to a 200mTorr or thereabouts? 24-Dec-19 01:09 PM Since it seems most plasma processes are in that pressure range from what I've read 24-Dec-19 01:12 PM Baratron! 24-Dec-19 01:12 PM @nmz787 yes the gauge is mks 901p . But @Deleted User I had questions is that possible to make ion gauge? 24-Dec-19 01:12 PM Also: anyone know the general differences between keithley 416 and 485 picoammeters? 416 is like 50X the wattage requirements, and is labelled "high speed" but they both seem to get to 10^-13 amps detection. 416 is also rack mount and relatively huge compared to 485... But also at least 6 or 8 years older design 24-Dec-19 01:13 PM they're made for applications like this, which is why they're heavily export restricted 24-Dec-19 01:13 PM @ahmadalinia i too have 901p, but it won't work in plasma 24-Dec-19 01:13 PM thanks to being able to handle UF6 24-Dec-19 01:13 PM @GigaSquirrel thanks, will check into them 24-Dec-19 01:13 PM Why it could not work in plasma . 24-Dec-19 01:13 PM bonus: They're absolute, meaning they don't care about what gas you're measuring 24-Dec-19 01:14 PM Is that true for any capacitance manometer? 24-Dec-19 01:14 PM the absolute part yes, the chemical resistance not sure 24-Dec-19 01:15 PM Manometern are really great gauge . 24-Dec-19 01:15 PM I've got a Baratron out of a dumpster and it reads funny 24-Dec-19 01:15 PM maybe the membrane broke? 24-Dec-19 01:15 PM But I think I will have to unplug all gauges before introducing any reactive gas anyway 24-Dec-19 01:15 PM No it works, sometimes 24-Dec-19 01:15 PM huh 24-Dec-19 01:16 PM Produces strange fluctuations that seems way too fast 24-Dec-19 01:16 PM might be as simple as a bad connection or cap 24-Dec-19 01:17 PM @ahmadalinia too fragile construction, the 901p manual even says don't use it in rough environment 24-Dec-19 01:17 PM Ebay baratrons are easily 2-5x the cost of the 901p... And from the ranges they look like i might need two or 3 units (100 torr and 10 torr) 24-Dec-19 01:19 PM It’s can not work in rough environment just. 24-Dec-19 01:19 PM Screenshot (Dec 24, 2019 1:19:36 PM) 24-Dec-19 01:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_20191224-131936-61B89.png 24-Dec-19 01:19 PM From "MKS Type 740B/750B/742B/752B, Ultraclean 840B/850B/842B/852B, Baratron Pressure Transducers and R700/R800 Series Relay Systems X 24-Dec-19 01:21 PM It’s bad news because I want to make magnetron cathode. 24-Dec-19 01:22 PM Mks901p warnings about usage 24-Dec-19 01:22 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_20191224-132216-2E2CE.png 24-Dec-19 01:22 PM It doesn't technically say no plasma... 24-Dec-19 02:34 PM I'm guessing the aggressive warning is because of the actual physical construction of the two gauges inside, not so much its sensitivity to plasma and whatnot. I think the gauge is going to be happy if it's just placed off somewhere to the side, not where plasma could reach it. 24-Dec-19 02:34 PM Which means it's going to be fine in 90% of hobbyist applications. Those that don't involve funny gases anyway. 24-Dec-19 02:34 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/ELg--ZtWsAEbDVA-670B5.png 24-Dec-19 02:35 PM Electrical tape works too 24-Dec-19 05:08 PM aeeek 24-Dec-19 05:54 PM @Deleted User and here I was planning to build a plasma chamber out of a pressure gauge... Damn. 24-Dec-19 05:55 PM somewhere in the world someone probably uses a plasma chamber of that size for some voodoo mems 24-Dec-19 07:24 PM I'm trying to evaluate a second hand/unknown history Balzers TPH-1500 turbopump. Rotor spins free/smoothly but I'm unsure about balance and whatnot. Before shelling out $$ for a controller I want to be somewhat confident it's in working order. Any advice/recommendations? 24-Dec-19 07:26 PM Use a bit of compressed air to spin it up maybe? 24-Dec-19 07:26 PM Not too fast, but enough to feel vibrations 24-Dec-19 07:26 PM But judging by where it came from, I think it should be fine 24-Dec-19 07:26 PM If you're willing to wait a while, my controller might be suitable for your turbo at a very low price compared to the original controller 24-Dec-19 07:40 PM I've got a dust collector/vac, will hook it up to the exhaust and see how she behaves 24-Dec-19 07:40 PM that will do it 24-Dec-19 07:40 PM just don't let it spin up too fast 24-Dec-19 07:40 PM if it starts vibrating after being quiet, you're getting into the resonance region and you should stop 24-Dec-19 07:41 PM Gotcha 24-Dec-19 07:41 PM Will give her a reflective sticker and rig up my tachometer on a indicator stand 24-Dec-19 07:41 PM Just off center shouldn't misbalance much 24-Dec-19 07:42 PM around 1-4krpm is safe for that big of a unit in air 24-Dec-19 07:42 PM Okay. Thank you! 24-Dec-19 07:42 PM Man for reals though. Y'all are so ridiculously helpful. 24-Dec-19 08:07 PM Could only get it up to about 800rpm with the top off. May series up some reducer flanges to up the velocity. Using a metal rod stethoscope I could hear the bearing doing its job but no oscillations and couldn't tell it was even moving by hand/feel. 24-Dec-19 08:07 PM Gonna check the windings and waveform here in a bit. Haven't been able to find any pinout for the connector but can only be so many. 24-Dec-19 08:22 PM @Metanoic re waveform, are you thinking to spin it with air and probe the pins with i.e an oscilloscope? 24-Dec-19 08:22 PM To get it acting as a generator? 24-Dec-19 08:22 PM Or just looking for shorts? 24-Dec-19 08:23 PM Not while spinning quickly, no. Just enough to ensure it looks correct. 24-Dec-19 08:23 PM And measuring point to point resistance 24-Dec-19 08:23 PM Yes, as a generator but not quickly 24-Dec-19 08:23 PM Mmm 24-Dec-19 08:23 PM Interesting 24-Dec-19 08:24 PM It's what I usually do to test BLDC's true KV rating 24-Dec-19 08:24 PM Basically just want to make sure it doesn't look like this 24-Dec-19 08:24 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DIrTodX-989C3.png 24-Dec-19 08:56 PM @Metanoic you can usually get the pinout from the controller manuals for the pfeiffer stuff 24-Dec-19 08:57 PM Yep I just came across it in the TCP-300 manual 24-Dec-19 08:57 PM https://cdn.shopify.com/s/files/1/0598/4021/files/Pfeiffer_TCP_380_Manual.pdf?8847793487024302246 page10/11 in this one 24-Dec-19 08:57 PM Pins ABCD are the windings and center triad 24-Dec-19 08:57 PM the 1500 doesnt work with the TCP-300 24-Dec-19 08:58 PM yea it still lists it though, just happened to be the manual that returned from some googling 24-Dec-19 08:58 PM This is a handy chart: http://www.hsdengineering.com/manuals/pfeiffer_table.pdf 24-Dec-19 08:58 PM nice! indeed it is 24-Dec-19 08:58 PM been looking for something like that the past few days. Thanks! 24-Dec-19 08:59 PM NP 24-Dec-19 08:59 PM happened to have bookmarked it when working on my turbo stuff 24-Dec-19 09:00 PM don't have a roughing pump yet either, need to sort that out >< 24-Dec-19 09:00 PM think I recall somewhere around 10^-3 is where the 1500 really starts working 24-Dec-19 09:02 PM @Metanoic http://www.emcgrath.com/catalog/images/VPT/Balzers-turbo-info.pdf 24-Dec-19 09:02 PM yea that doc is buggy it seems, cuts the pages off 24-Dec-19 09:02 PM or at least lists very little info pertaining directly to the 1500 24-Dec-19 09:03 PM looks like that's just it 24-Dec-19 09:04 PM page D5 "The program is continued on the next page" - last page, hehe 24-Dec-19 09:04 PM or a muppet scanned it 24-Dec-19 09:05 PM I think that might be the case. Either way, the TCP doc gave me a plot that was useful 24-Dec-19 09:05 PM I'll do some more searching in earnest for the exact specs table here in a bit when I'm done vetting the motor 24-Dec-19 10:28 PM you know what you could do 24-Dec-19 10:28 PM I know what you could do 24-Dec-19 10:28 PM gently unscrew that connector and you'll find thicker wires going to the motor 24-Dec-19 10:28 PM @Metanoic 24-Dec-19 10:29 PM yea they'll certainly be beefier 24-Dec-19 10:29 PM been inside cleaning up, haven't even made it back out to the shop since our last messages 24-Dec-19 10:29 PM officially xmas here now.. merry xmas errbody! 24-Dec-19 10:30 PM I've been cleaning a servo motor that was in a fire 24-Dec-19 10:30 PM and yes merry xmas 24-Dec-19 10:30 PM that sounds like a blast, lol 24-Dec-19 10:30 PM everything is covered in yellow probably cancer 24-Dec-19 10:30 PM the friend who gave it to me said that the person he got it from said (lol) that the servo drive was complaining that the encoder is dead 24-Dec-19 10:30 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191225_081228-C2FF5.jpg 24-Dec-19 10:30 PM said encoder 24-Dec-19 10:32 PM Can't really make out much detail but it definitely looks non-concentric 24-Dec-19 10:32 PM it's actually in perfect shape 24-Dec-19 10:32 PM no idea what failed, PCB looks pristine 24-Dec-19 10:33 PM Must just be the angle then 24-Dec-19 10:33 PM I re-seated everything, made sure it almost-but-not-quite touches the sensor 24-Dec-19 10:33 PM but either way it's another servo for the UniServo project testing! 24-Dec-19 11:30 PM @Applied_Ion so I've got two computer controlled HV power supplies, one up to 4.5 kV and the other up to 3kV, both say something like 300mA max... Voltage current or watts control (at least i think they have Watts control). Which should i start with for the gliding arc plasma setup? I got some stainless rods about 3 inches long that I think should work, was looking for a nut to screw their ends into, and just tighten the wires between two nuts 25-Dec-19 12:00 AM What power supplies do you have, out of curiosity? 25-Dec-19 12:11 AM I'm surprised we aren't seeing tunable piezo transformers applied to this field. I'm still pretty far out from groking the power supply requirements, but enough to know high voltage is fundamental. Piezo transformers are great at that, and the modern tunable radial transformers fit the tunable gain requirement. 25-Dec-19 12:19 AM Another benefit is the fact that the primary "coil" is high impedance, opposite of an EM transformer, which will lend itself better to stable output with a simpler circuit. Already isolated, and intrinsically low current too. 25-Dec-19 12:20 AM sadly they're not very powerful or very high voltage 25-Dec-19 12:20 AM but they're cheap-ish 25-Dec-19 12:20 AM https://www.steminc.com/PZT/en/multilayer-piezo-transformer 25-Dec-19 12:39 AM State of the art uses lithium niobate rather than pzt. University of Missouri worked on a Linbo3 transformer for driving a neutron source. 50+kv at 1:100 step up is doable. Just good luck getting your hands on one. If only we had the equipment to fabricate thin films. 25-Dec-19 12:39 AM Make that 100kv @ 20 watts from U of M. 25-Dec-19 12:46 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/15772635456871818675953-EB0C1.jpg 25-Dec-19 12:46 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/1577263602761729398006-19745.jpg 25-Dec-19 01:16 AM Haha 25-Dec-19 02:14 AM So on that gray-blue coating. Using sodium carbonate as a dry slight abrasive + water for reaction to carbonic acid and some light scrubbing with an ultrasonic toothbrush takes it right off. Will test a strong carbonic acid solution and see if I can't get quicker results without having to scrub every surface. 25-Dec-19 02:55 AM @Nixie I am french and it took me some time to get it haha 25-Dec-19 03:14 AM @Epilogis my condolences 25-Dec-19 07:14 AM Going back to "slow pumping" via KF25: If chamber is 1L, and conductance calculation will tell that pump speed will be 10L/sec, that still means I should reach high vacuum way under 1 minute? Or I am missing something? 25-Dec-19 09:38 AM @ZeptoBars i wonder if that speed is for viscous flow only, not molecular? 25-Dec-19 09:38 AM P.s. my power supplies are: biorad 3000xi, Life Technologies BRL Model 4000 25-Dec-19 09:41 AM It's not that linear of a relationship. Calculating pumpdown time to high vacuum is particularly difficult and still only an estimate at best. I don't have my resources with me to calculate it since I'm traveling but it's not trivial 25-Dec-19 09:41 AM Pumping speed and time is different over each pressure regime as well. So it will vary from viscous flow, to transitional flow, to molecular flow 25-Dec-19 09:41 AM Different equation sets for each 25-Dec-19 10:41 AM @Applied_Ion do the gliding arc power supplies need to be AC? 25-Dec-19 11:00 AM Nope, can be AC or DC, only time it makes a difference if you are doing magnetic arc rotation, where you need DC. Other than that it doesn't matter. 25-Dec-19 11:05 AM @ZeptoBars you won't get down to high vacuum in a minute through a KF25 25-Dec-19 11:05 AM or through an ISO100 25-Dec-19 11:05 AM if you had a direct volume of ISO100x100mm above the pump, you'd probably get down to HV in... a few minutes, max 25-Dec-19 11:05 AM but through a KF25 you're probably looking at closer to 10-30 minutes 25-Dec-19 11:07 AM Calculating the effective pumping speed is only part of a story, you must balance it with the gas loads in the chamber from outgassing and so on. 25-Dec-19 11:07 AM I've got lots of example calculations on my website lol 25-Dec-19 11:07 AM For effective speeds and outgassing 25-Dec-19 11:07 AM Very tedious if accounting for everything 25-Dec-19 11:07 AM But calculating pumpdown times requires all that stuff, but gets even more complex 25-Dec-19 11:09 AM The best way to is to test 25-Dec-19 11:09 AM You get an exact number!!! 25-Dec-19 11:09 AM I didn't do pumpdown times since it just got crazy lol 25-Dec-19 11:09 AM But yeah, testing is the best way 25-Dec-19 11:10 AM You're getting pretty successful with your ion pew guns 25-Dec-19 11:10 AM I did effective speeds and gas loads though, then confirmed with Molflow 25-Dec-19 11:10 AM On that note, you talk about power inputs and thrust on your site - does that account for electronics efficiency? 25-Dec-19 11:10 AM Seems like when you're dealing with single-digit watts you'd want to push efficiency to the high nineties 25-Dec-19 11:12 AM Yeah, the power factors in power supply efficiency 25-Dec-19 11:12 AM Efficiency is tough at that level and size 25-Dec-19 11:12 AM Like the emco Q series are like 60% at most, closer to 50 25-Dec-19 11:12 AM The new ones I'm looking at for the ion thruster is pushing closer to 80% 25-Dec-19 11:15 AM What's your spec requirement? 25-Dec-19 11:15 AM Vin, Vout, Iout, ripple 25-Dec-19 11:16 AM Depends on the system. Vin like 5v most, Vout like 3kv, current is hundreds of microamps, ripple not too worried about 25-Dec-19 11:16 AM The big things are size and power though 25-Dec-19 11:16 AM As humanly small as possible 25-Dec-19 11:16 AM These supplies are on the order of 0.5" cube 25-Dec-19 11:17 AM A few hundred microamps at 3kv is doable discretely and pretty efficiently 25-Dec-19 11:18 AM With a flyback transformer? 25-Dec-19 11:18 AM It is but size is a challenge 25-Dec-19 11:18 AM Try finding an efficient flyback that small lol, including rectifiers 25-Dec-19 11:18 AM These companies got the tech packaged smaller than can be done discreetly. And also well qualified for aerospace 25-Dec-19 11:19 AM seems like a job for piezo transformers and a very lightweight doubler 25-Dec-19 11:19 AM https://www.steminc.com/PZT/en/piezo-transformer-55-khz-3w 25-Dec-19 11:19 AM at 55khz drive your doubler can be basically superficially small 25-Dec-19 11:20 AM Too high power input lol. Also the supplies I'm using already have the oscillator as well. Just Vin and it works 25-Dec-19 11:21 AM Well, yeah, but price and weight/size 25-Dec-19 11:21 AM 3W is maximum power 25-Dec-19 11:21 AM Are they aerospace grade though? 25-Dec-19 11:21 AM These other supplies have a lot of flight heritage 25-Dec-19 11:21 AM What does it constitute? 25-Dec-19 11:22 AM Being qualified in space and space testing applications lol 25-Dec-19 11:22 AM You can get automotive grade parts, that piezo won't explode in space 25-Dec-19 11:22 AM That's all the "space grade" manufacturers are doing I bet 25-Dec-19 11:22 AM Yeah I use automotive for lots of other parts 25-Dec-19 11:22 AM besides testing of course 25-Dec-19 11:23 AM The Vin to Vout isn't enough 25-Dec-19 11:23 AM 18Vin for 1800Vout 25-Dec-19 11:23 AM you'd use a voltage doubler or tripler on the output 25-Dec-19 11:23 AM and a small boost on the input 25-Dec-19 11:23 AM it's just a transformer 25-Dec-19 11:23 AM but it's more compact and lighter than magnetic 25-Dec-19 11:25 AM 0.5" cube for oscillator, transformer, and rectifier all potted is pretty small lol 25-Dec-19 11:25 AM it is 25-Dec-19 11:28 AM The piezo transformer is actually pretty big. 1.37" long, about .37" wide 25-Dec-19 11:39 AM but very thin 25-Dec-19 11:43 AM Yeah quite thin for sure. For now footprint is more critical than height cramming this all into a tiny board lol 25-Dec-19 11:43 AM Definitely will keep it in mind for some applications though, I can see it being useful for stuff. Actually, running as AC instead of rectified has an advantage 25-Dec-19 11:43 AM Particularly for electrospray, though tens of khz may be way too fast 25-Dec-19 11:43 AM Though I'd have to swing +/- across 0 for it to work as needed 25-Dec-19 12:02 PM Turns out the TPU/TPH motors are 2 phase. In any case, waveform looks just fine. Ready to pull the trigger on a controller for it. 25-Dec-19 12:02 PM That's a lot of money 25-Dec-19 12:02 PM My drive will drive 2 phase motors 25-Dec-19 12:02 PM But if you need one now, you might have to buy the original 25-Dec-19 12:35 PM Yea I've yet to evaluate any features and whatnot. I know there are various integration abilities with turning on the roughing pump and basic delays etc but that's it. 25-Dec-19 12:35 PM You got a tindie link or anything like that? @Deleted User 25-Dec-19 12:37 PM It's not for sale yet 25-Dec-19 12:37 PM https://i.spirit.re/uavWr.png 25-Dec-19 12:37 PM screaming internally 25-Dec-19 01:17 PM Huh, got rid of the HV channel completely :( 25-Dec-19 01:18 PM #lasers_and_optics is it 25-Dec-19 01:18 PM I guess general it is! 25-Dec-19 01:18 PM yes 25-Dec-19 01:18 PM /me starts flooding general with HV stuff 25-Dec-19 01:18 PM @Applied_Ion ok cool, thanks. Any idea why people seem to differentiate corona discharge from gliding arc? They seem to be the same exact thing, just with needles instead of rods (ignoring gas flow as I've seen that in the corona discharge category too) 25-Dec-19 01:21 PM Corona discharge is different from gliding arc 25-Dec-19 01:21 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/prexab5a30f9_lr-BB049.jpg 25-Dec-19 01:21 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/prexab5a30f8_lr-CC683.jpg 25-Dec-19 01:21 PM Both nonthermal atmospheric plasmas, but still pretty different 25-Dec-19 01:22 PM How so, it really just seems the electrode placement is all that changes 25-Dec-19 01:22 PM No a Corona discharge is not quite the same as an arc discharge 25-Dec-19 01:22 PM This stuff seems so confusing and i cant tell if it's just po-tay-toh poh-tah-to 25-Dec-19 01:23 PM Different degree of ionization and discharge mechanisms. Very different actually lol 25-Dec-19 01:23 PM Wikipedia says "An arc discharge is characterized by a lower voltage than a glow discharge and relies on thermionic emission of electrons from the electrodes supporting the arc." 25-Dec-19 01:23 PM But how would you prevent thermionic emission with higher voltage? 25-Dec-19 01:25 PM Well it's not so much the applied voltage they are referring to. Both can be initiated at the same voltage levels 25-Dec-19 01:26 PM "When an arc starts, its terminal voltage is much less than a glow discharge, and current is higher. " 25-Dec-19 01:26 PM But but v=ir 25-Dec-19 01:26 PM Won't R be the same in a given gas plasma? 25-Dec-19 01:26 PM From that it seems like glow discharge is simply pulsed due to lack of charge reservoir on the power source 25-Dec-19 01:26 PM Higher impedance source, thus shorter lived plasma 25-Dec-19 01:29 PM It has to do with where in the discharge regime it occurs. 25-Dec-19 01:29 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Figure-11-I-V-characteristics-of-a-DC-glow-EFBB9.png 25-Dec-19 01:29 PM Glow discharge is easier at higher frequency than DC since breakdown mechanisms change depending on the driving voltage type 25-Dec-19 01:30 PM So with more gas pressure you only get arc? Because the plasma resistance would consume all the current of a weak power source? 25-Dec-19 01:30 PM Or at extremely restricted currents for dc 25-Dec-19 01:30 PM Not necessarily 25-Dec-19 01:31 PM What i mean is, if i had a gigaohm resistor connecting a high impedance HV source to it, it would keep the voltage high, but swapping that with say 100 ohm would pull the source voltage down to nothing (assuming high impedance source) 25-Dec-19 01:32 PM Yeah in that case 25-Dec-19 01:32 PM So since the gas load is the resistor... 25-Dec-19 01:32 PM Not really though 25-Dec-19 01:32 PM It's more complex than that 25-Dec-19 01:32 PM Hmm 25-Dec-19 01:34 PM Usually for Corona discharge you limit the supply 25-Dec-19 01:34 PM What exactly are you trying to figure it out for? General or a specific application? 25-Dec-19 01:36 PM Trying to figure out how to ensure a nickel surface is oxidized with HO groups, so perfluro-decyl-trichlorosilane will come in and evolve HCl leaving O-Si-R 25-Dec-19 01:36 PM Using inductively coupled residual air plasma seems to make RTV silicone bond well to the nickel... hot 50% H2O2 for an hour also seems to work 25-Dec-19 01:37 PM Are you using atmospheric Corona discharge 25-Dec-19 01:37 PM Oh lol typed before I did 25-Dec-19 01:38 PM But for a much much larger substrate the ICP chamber is too small, and that much hot H2O2 sounds annoying to work with 25-Dec-19 01:38 PM It's a plasmod vacuum chamber with 13.56 MHz (I believe) 25-Dec-19 01:39 PM What pressure? 25-Dec-19 01:39 PM Just roughed 25-Dec-19 01:40 PM At MHz drive and roughed you will be in glow discharge 25-Dec-19 01:40 PM I was thinking gliding arc gun on a gantry, with oxygen gas and water spray might work for larger substrate 25-Dec-19 01:40 PM So I've got the HO atoms in the plasma 25-Dec-19 01:40 PM And none of the nitrogen from atmosphere 25-Dec-19 01:40 PM Since I've got no clue how they'd affect the silane reaction, but have to assume it would confound things 25-Dec-19 01:42 PM Discharge regimes also vary with pressure. I have seen gliding arc for gas processing and plasma reactors, that's one of it's primary uses 25-Dec-19 01:42 PM So arc would have more energy in the ions? 25-Dec-19 01:42 PM Usually for hydrocarbon reforming though 25-Dec-19 01:42 PM Could that cause more-than-surface effects? 25-Dec-19 01:42 PM Yeah i saw that term on your website 25-Dec-19 01:42 PM Don't really know what it means other than assuming something like hydrocarbon cracking 25-Dec-19 01:43 PM Yeah pretty much lol 25-Dec-19 01:43 PM Or chemical processing, like destruction of organics 25-Dec-19 01:44 PM That would be good too, clean the surface and prep for the teflonization 25-Dec-19 01:46 PM Gliding arc is good for surface activation, but plasma cleaners would work better for surface cleaning 25-Dec-19 01:47 PM Lol, but gliding arc makes plasma 25-Dec-19 01:47 PM Wouldn't it just be some different gas mix? I mean, enough activation of a surface hydrocarbon, won't it turn to CO2? 25-Dec-19 01:47 PM Seems like activation is a bit of a wildcard term 25-Dec-19 01:49 PM Activation refers to raising the surface energy of a substrate higher to that of an applied coating to increase adhesion 25-Dec-19 02:03 PM Haha well if oxygen adheres really well to carbon... 25-Dec-19 02:03 PM Back to reading i guess 25-Dec-19 02:03 PM Seems like i just have to try some experiments, all the terminology as applied to applications seems a bit muddled 25-Dec-19 04:22 PM If you were working with Si and you wanted to achieve the same thing (eg. for hexamethyldisilazane reaction) you would typically use a Piranha clean or O2 plasma. I think either would work on Ni, I don’t think Piranha will dissolve Ni but check it first 25-Dec-19 04:22 PM People sometimes talk about UV Ozone treatment for this sort of thing too. 25-Dec-19 04:44 PM Are we talking about surface activation with cold plasma? 25-Dec-19 04:44 PM For adhesives and coatings and whatnot? 25-Dec-19 04:45 PM Part of the discussion lol 25-Dec-19 04:46 PM What's the goal in this particular instance? 25-Dec-19 04:47 PM Not exactly sure, I'm not familiar with the process @nmz787 is aiming for 25-Dec-19 04:47 PM Are you looking for something like this? https://www.youtube.com/watch?v=Lr8GR0lj5-g 25-Dec-19 04:49 PM That's definitely a high power system. Vortex stabilized gliding arc, bigger than the one I built 25-Dec-19 04:49 PM Power is everything for surface activation time 25-Dec-19 04:49 PM Stupid easy to build though lol 25-Dec-19 04:49 PM just a discharge and some blowy gases 25-Dec-19 04:49 PM also lol 25-Dec-19 04:49 PM https://www.youtube.com/watch?v=fMUemBZ0k5Q 25-Dec-19 04:50 PM I'll eventually design some nicer systems than my junk setup lol 25-Dec-19 04:50 PM That is the junkiest system ever 25-Dec-19 04:50 PM But MIT says it works 25-Dec-19 04:50 PM haha 25-Dec-19 04:50 PM My gliding arc system is a lot more junk than that lol 25-Dec-19 04:50 PM But yeah, modded microwaves are popular 25-Dec-19 04:50 PM stick a low pressure jam jar into your household plasma cleaner in disguise 25-Dec-19 04:50 PM roast for 30 seconds 25-Dec-19 04:53 PM I want to see more people experimenting with plasma assisted combustion. Some really neat stuff, and super easy especially with gliding arc.been wanting to make an instrumented rig for studying the process more 25-Dec-19 04:54 PM I'm tempted to make a plasma torch for cleaning stuff 25-Dec-19 04:54 PM Nonthermal or thermal? 25-Dec-19 04:54 PM nonthermal 25-Dec-19 04:54 PM I'm tempted to make many things, but the lack of an extra 0 in my accounts says no 25-Dec-19 04:55 PM Nice lol. Thermal torches for diy plasma spray are on the project list as well. Stupid expensive commercially, not much on eBay either, but quite simple to diy and can be done relatively cheap 25-Dec-19 04:55 PM Same lol 25-Dec-19 04:55 PM So many cool projects and not enough money 25-Dec-19 11:11 PM @Deleted User yeah the Gantry is what I'd need as the substrate is about 4 sqft 25-Dec-19 11:11 PM Hot h2o2 might work for the activation though 25-Dec-19 11:11 PM Might try to rig up a gliding arc plasma tomorrow, though I'm still not 100% sure how it won't be a glow discharge blower :p 25-Dec-19 11:11 PM @Deleted User and yeah I've seen the microwave with a bell jar in it before, would need a huge Microwave for this current project 25-Dec-19 11:22 PM You can make them as wide as you want @nmz787 25-Dec-19 11:22 PM Microwaves? 25-Dec-19 11:22 PM no plasma treaters lol 25-Dec-19 11:23 PM Oh, seems like that'd need a proportional amount of power 25-Dec-19 11:23 PM Vs just rastering over 25-Dec-19 11:23 PM cold plasma doesn't take too much power 25-Dec-19 11:23 PM if any really 25-Dec-19 11:23 PM a meter long system, if you can build one, will eat maybe 100W 25-Dec-19 11:23 PM or something like this 25-Dec-19 11:23 PM https://www.youtube.com/watch?v=7F2OqmqJBCw 25-Dec-19 11:25 PM Hmm, @Applied_Ion diy pages seemed to indicate he had one low and one high power, and the high power seemed liked kilowatts but was still pretty small in beam waist 25-Dec-19 11:25 PM cold helium plasma 25-Dec-19 11:25 PM hot plasma will be kilowatts 25-Dec-19 11:25 PM cold not so much 25-Dec-19 11:25 PM argon also works 25-Dec-19 11:25 PM https://www.youtube.com/watch?v=ITIRW9KdrHg 25-Dec-19 11:25 PM RF or not, it doesn't really matter 25-Dec-19 11:25 PM though RF is probably the easiest to set up, all you need is a tube and some copper tape 25-Dec-19 11:25 PM also @Metanoic https://www.youtube.com/watch?v=gUXXjS_bq8g 25-Dec-19 11:25 PM piezo :P 25-Dec-19 11:29 PM How does the piezo work? I couldn't read the french in the diagram 25-Dec-19 11:30 PM you shove a kHz sine wave on the top and bottom of one side of the crystal, you get high voltage from the "front" end and one side of the feed power 25-Dec-19 11:30 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Piezo_Transformer-9491B.png 25-Dec-19 11:32 PM So just like a cigarette/grill electronic lighter, instead of a physical hammer action, you can just electronically excite/hammer? 25-Dec-19 11:32 PM yes, and it's much higher power 25-Dec-19 11:32 PM sort of a solid...well... not solid, closer to jello-state transformer. 25-Dec-19 11:33 PM Huh 25-Dec-19 11:33 PM a cheap source of complete step-up systems can be found by searching for "sony vaio inverter" on ebay/aliexpress 25-Dec-19 11:33 PM https://www.ebay.com/itm/Sony-Vaio-PCG-7121M-VGN-NR21Z-LCD-SCREEN-BACKLIGHT-INVERTER-BOARD/401368269606 25-Dec-19 11:33 PM you want this kind 25-Dec-19 11:33 PM drive circuit, mini step up(~90VAC 50kHz ish), and then the multilayer transformer 25-Dec-19 11:33 PM clearly visible 25-Dec-19 11:35 PM https://www.ebay.com/itm/Sony-Vaio-PCG-FX140-FX220K-FX800-FX804-FX950-FXA59-9G2M-VGN-N38E-LCD-Inverter-/153423101255 25-Dec-19 11:35 PM That one too? 25-Dec-19 11:35 PM might be 25-Dec-19 11:35 PM I don't see any kapton 25-Dec-19 11:39 PM This seems closer to what you posted 25-Dec-19 11:39 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/15773459245283549940116172985248-B4186.jpg 25-Dec-19 11:39 PM as long as there's that big grey blob with an electrode on top and end 25-Dec-19 11:40 PM Hmm, can't just yank one out of a grill lighter, eh. 25-Dec-19 11:40 PM Sputter on some contacts? 25-Dec-19 11:41 PM it's a completely different crystal 26-Dec-19 12:12 AM @Spirit StemInc has a transformer suitable for plasma btw. They link to a French paper on the product page that applies it. 26-Dec-19 12:12 AM They do 26-Dec-19 12:12 AM But they also want nearly $70 in shipping for a 5 gram part 26-Dec-19 12:12 AM so screw them 26-Dec-19 12:12 AM Eek. I have one on hand. Shipping to the US is cheap from them ofc 26-Dec-19 12:12 AM I have just about one or two of all their products lol 26-Dec-19 12:14 AM I'm interested in seeing how well it would work for two things: 1: A super compact plasma torch 2: A low power ~20kV @ ~0uA supply(w/ multipliers) for my nanofocus x-ray tube 26-Dec-19 12:14 AM Seems like the ultra high switching frequency would work well with tiny and low leakage multiplier stages 26-Dec-19 07:52 AM No mine was over a kW 26-Dec-19 07:52 AM Still nonthermal 26-Dec-19 07:52 AM Treated printer paper and other temperature sensitive stuff. Even plastics for long periods of time they just get warm 26-Dec-19 07:52 AM It's about expanding the extinction zone to keep the plasma in nonequlibrium 26-Dec-19 07:52 AM The lower the power level, the longer treatment will take 26-Dec-19 07:52 AM I used MOTs to power my system. Two in anti-series on the output, parallel input, and a third for ballasting. Just need suitable airflow and wide divergence for planar electrodes. Coaxial vortex will be more concentrated, but with faster treatment time 26-Dec-19 07:52 AM Those cold helium RF excited pencil plasmas will not be that useful for activation. Those are more suited for medical applications such as sterilization and wound treatment 26-Dec-19 07:52 AM The thermal nature of a plasma doesn't depend purely on power. You can have tens of kW pumping into a system but still be nonthermal. More power allows you a larger treatment area or volume (depending on setup) as well as faster treatment times. 26-Dec-19 07:52 AM If you are going for gantry style activation for large surfaces, I would definitely say don't go low power, it will take way too long 26-Dec-19 07:52 AM A meter long system will definitely take more than 100W too lol. For big continuous surface areas using a wide plasma generator, you will want a large surface dielectric barrier discharge running at high power rather than a pencil type Corona discharge or even gliding arc. 26-Dec-19 07:52 AM Also for any frequency driven plasma you have to take into account the gas, power level, frequency, and pressure. Helium is often used for MHz atmospheric plasmas since it is very easy to excite at low power. Overall I wouldn't say RF is easier. Kind of mid range, gliding arc is by far the easiest atmospheric plasma setup. Dielectric barrier discharge (DBD) is probably the most involved. Also different types will have different intensities. Since gliding arc operates more in a quasithermal regime, activation will be faster than very "cold" plasmas, though DBD is still cold in the thermal sense (but gliding arc is higher "temperature" when talking about plasma equilibrium as well). 26-Dec-19 08:19 AM So for applications like surface activation, regardless if gliding arc or Corona discharge, go as high power as you can and adjust your setup to bring the plasma into nonequlibrium. For medical applications like wound healing and sterilization power is far less important, more about the type of plasma used. For gas reforming and combustion, reactor topology is a main consideration (though power is also a factor as well). 26-Dec-19 08:28 AM The ultimate test for activation is with Teflon, since that has one of the lowest surface energy of any plastic. Simple contact angle or ink streak test is dirt simple to verify activation. If you want to go hardcore you can buy calibrated fluids for activation level measurement. Regular water or ink works perfectly fine though for activation verification 26-Dec-19 08:28 AM Also activation is a highly selective process. So only areas directly exposed to the plasma, allowing for masking and fine activation as well. I've seen robotic arms with tight coaxial gliding arcs for activation of edges for adhesives in production line setups 26-Dec-19 01:17 PM Quoted for a pump from distributor: £4k 26-Dec-19 01:17 PM go direct to the manufacturer: £1,400 26-Dec-19 01:28 PM Scientific distributors are generally scalpers 26-Dec-19 02:50 PM didn't realize it was that bad 26-Dec-19 02:50 PM most industries I work in, it's usually just 20-40% 26-Dec-19 03:02 PM Not sure if this has been posted here, credit goes to qualia who tweeted it 26-Dec-19 03:02 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-14533.png 26-Dec-19 03:02 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image1-79187.jpg 26-Dec-19 03:02 PM Use “chicken” for PR ashing, “popcorn” for PDMS and “defrost” for Si 26-Dec-19 03:16 PM what are some of the use cases of that? 26-Dec-19 03:24 PM Plasma cleaning, surface activation, nothing you can't do yourself for a tiny fraction of the cost lol 26-Dec-19 03:27 PM nice 26-Dec-19 03:27 PM any suggestions on a geiger counter for some experiments or things to look out for? 26-Dec-19 03:27 PM oh will move this to #radiation 26-Dec-19 03:45 PM Making that yourself seems like the cheapest way to do oxygen plasma cleaning. 26-Dec-19 04:30 PM the oxygen-rated oil for your backing pump will cost three times more than the Cuisinart RF ashing microwave 26-Dec-19 04:30 PM probably wouldn't want to use a used microwave either 26-Dec-19 04:30 PM it's just such a comical product 26-Dec-19 04:31 PM the trick there is to use a pump you hate 26-Dec-19 04:31 PM so you're happy when it breaks 26-Dec-19 04:32 PM No 26-Dec-19 04:32 PM Please no 26-Dec-19 04:32 PM It's not just going to kill the pump 26-Dec-19 04:32 PM it doesn't break it becomes a bomb 26-Dec-19 04:32 PM Yeah 26-Dec-19 04:32 PM That 26-Dec-19 04:32 PM Place it in a ditch outside 26-Dec-19 04:32 PM Oxogen gets desolved in the hydrocarbon oil 26-Dec-19 04:33 PM grumble mumble conductance losses 26-Dec-19 04:33 PM okay fine just use a membrane pump 26-Dec-19 04:33 PM Is this remotely suitable for Plasma Cleaning? 26-Dec-19 04:33 PM And a hydrocarbon with a bunch of oxogen in it is not a good idea 26-Dec-19 04:33 PM What the pump or microwave? 26-Dec-19 04:33 PM Also do you want plasma cleaning or ashing? 26-Dec-19 04:34 PM apparently 100% oxygen just makes oil-soaked anything spontaneously burst into flame 26-Dec-19 04:34 PM naw 26-Dec-19 04:34 PM certain oils will cause cloths to start burning 26-Dec-19 04:34 PM Cleaning can just be done with nitrogen. It kinda just scrubs the surface 26-Dec-19 04:35 PM I need to plasma clean PTFE sheet 26-Dec-19 04:35 PM from contaminants 26-Dec-19 04:35 PM And that doesn't need a special pump 26-Dec-19 04:35 PM You probably want oxogen 26-Dec-19 04:35 PM It's a lot more aggressive 26-Dec-19 04:35 PM But maybe nitrogen would work? I don't know 26-Dec-19 04:36 PM hmm 26-Dec-19 05:10 PM Nitrogen sounds safer 26-Dec-19 05:10 PM Or use a diaphragm pump or other dry pump 26-Dec-19 05:10 PM A gallon of Fomblin is not cheap 26-Dec-19 05:16 PM drug dealers should reorient themselves to fomblin dealing 26-Dec-19 06:47 PM Then you have to worry about it being cut with inferior product 26-Dec-19 06:51 PM Fomblin cut with fumblin 26-Dec-19 10:54 PM Well, the max3232 chip i hooked up to my mks901p gets super hot for no apparent reason, i can only guess it's fake as other folks online have complained about 26-Dec-19 10:54 PM Guess I'll have to boil it in nitric and optical microscope and FIB it to see up close and compare die images 26-Dec-19 10:54 PM Pretty lame tho, I was hoping to get some readings tonight and now I've got to unsolder stuff 26-Dec-19 10:54 PM Have 9 more of these from Amazon, but I think I might have some genuine exar chips inside to replace it with 26-Dec-19 11:09 PM Replacement went fast, wore my ESD wrist strap this time... So who knows... 26-Dec-19 11:09 PM Could be a weird TTL converter fake that doesn't enjoy real rs232 26-Dec-19 11:10 PM Now my laptop is dead and i need to go into the house for my charger 26-Dec-19 11:10 PM Not sure if the 901p outputs real rs232(+3-5 to -9) as I haven't tested it yet 26-Dec-19 11:10 PM Well what i ordered wasn't sold as fake, lol 26-Dec-19 11:10 PM lol 26-Dec-19 11:25 PM Ugh, immediately got super hot 26-Dec-19 11:41 PM Are you sure you're connecting it right 26-Dec-19 11:41 PM Try making it talk to another one of itself 26-Dec-19 11:43 PM Yeah I'm quite sure 26-Dec-19 11:43 PM Just connected vcc and gnd this time , 2nd replacement tonight 26-Dec-19 11:44 PM What voltage are you supplying it with? 26-Dec-19 11:44 PM Meter shows 4.83 26-Dec-19 11:44 PM From a usb to ttl converter 26-Dec-19 11:45 PM Well, that's really the only thing that can kill a max3232 26-Dec-19 11:45 PM It's dead 26-Dec-19 11:45 PM (to clarify: you didn't kill it, DOA) 26-Dec-19 11:56 PM Another one, pwr and gnd and ttls dont seem to heat it, but shorting the rs232 side produces garbage on my rx tty 26-Dec-19 11:56 PM Ugh 26-Dec-19 11:56 PM Time for an acid swim 27-Dec-19 12:03 AM Tried asking for return hoping they'd just refund me... But they actually want them returned 27-Dec-19 12:03 AM Might desolder one chip from one of the PCBs and keep it 27-Dec-19 12:08 AM Amazon? 27-Dec-19 12:08 AM Or eBay? 27-Dec-19 12:08 AM If so, escalate 27-Dec-19 12:14 AM Amazon 27-Dec-19 12:14 AM I'll just say it ripped off if they fail to return my $4.79 27-Dec-19 12:14 AM Or find some other 16 pin chip in the house to solder on 27-Dec-19 12:24 AM The most fascinating thing is that nowadays, making custom panel keyboards is inexpensive (compared to the pricing of the units) 27-Dec-19 02:04 AM I will hook up a 901p in the next couple of days so I’ll confirm RS232 levels 27-Dec-19 09:08 AM I too was planning on scoping things out but decided it was lazier to just try a loop back test 27-Dec-19 09:08 AM I guess i wouldn't have got too far anyway with the level converter chips not working 27-Dec-19 02:35 PM leybold trivac d2.5e just arrived! oil everywhere...time for some TLC 27-Dec-19 02:35 PM maybe i can freeze dry some food this weekend 27-Dec-19 02:40 PM just be careful about oil backstreaming 27-Dec-19 02:40 PM don't want the pump's oil in your food 27-Dec-19 02:40 PM also, it's not a great idea to pump water with your science vacuum pump 27-Dec-19 02:51 PM ahh, well i'll try with my basic pump then 27-Dec-19 02:51 PM how do i prevent oil backstreaming? the box was clearly not upright while shipped so there's oil everywhere 27-Dec-19 02:51 PM i'll clean it up real nice and we'll see how it goes 27-Dec-19 03:07 PM Cold trap between your pump and sample... In fact that would protect your pump and your sample 27-Dec-19 03:08 PM ahh yeah that's the goal, not sure if there will still be some water that would get through or not. going to try dry ice + ethanol 27-Dec-19 03:14 PM Got some replacement rs232 chips! They're max232, not max3232... But that seems to just mean they need 5v supply rather than 3 to 5v, which is fine by me 27-Dec-19 03:27 PM @nmz787 did you ever figure out why it was hot? 27-Dec-19 03:32 PM Nah but i will decap it today or tomorrow 27-Dec-19 03:32 PM nice 27-Dec-19 03:32 PM nitric acid? 27-Dec-19 03:32 PM Thinking I'll try a few approaches, hot nitric, tree rosin, and co2 laser 27-Dec-19 03:32 PM Since i have a few to play with 27-Dec-19 03:32 PM ahh cool, i haven't tried rosin/co2 27-Dec-19 03:32 PM i heard rosin is interesting 27-Dec-19 03:33 PM I tried rosin on an intel xeon, but it was basically a die soldered to the pcb/interposer/carrier so not much epoxy for the rosin to work on... Also i used a hot plate, but seems a test tube and torch would be better/hotter 27-Dec-19 03:34 PM ahh 27-Dec-19 03:37 PM Molten rosin is probably the easiest to do with household stuff 27-Dec-19 03:37 PM Since all you need is a glass container and something to remove your nose 27-Dec-19 05:41 PM lol 27-Dec-19 05:41 PM Yeah figured that it would smell rather intensly 27-Dec-19 09:48 PM Smelled like Christmas! 28-Dec-19 12:49 AM eee yay my microscope slides arrived 28-Dec-19 12:49 AM time to make some mirrors.. c: 28-Dec-19 01:15 AM Ooo, an interesting comment re the fake/buggy max3232s 28-Dec-19 01:15 AM "Turns out some of the clone chips are missing pull up resistors on the logic level input pins. If you leave any pins floating you'll pick up stray signals,  start oscillating and get the observed heating." 28-Dec-19 01:15 AM So i might try grounding the other transceivers to see if that changes my success in usage 28-Dec-19 01:15 AM (didn't get back to the garage today/tonight to swap for real chips i got locally) 28-Dec-19 01:23 AM Next challenge: Using a malfunctioning max3232 as a clock for a microcontroller. 28-Dec-19 02:06 AM Is there any one have ideas about SEM Thermounic Electron gun ?? Could you please give me some idea 28-Dec-19 02:23 AM @AdamMcCombs had an interesting book around, I din't know the pricing for a copy of it. 28-Dec-19 02:32 AM @AdamMcCombs could you please give me some idea because I want to build one Wehnelt cap and anode . I want to do it with cst particle . But not sure about shape . Thanks @Nixie 28-Dec-19 03:45 AM make a conductive filament and heat it up until electrons boil off of it 28-Dec-19 03:45 AM bend the filament into a point so it brings the electric field gradient to a point and watch them spray off 28-Dec-19 03:45 AM then stick a conductive target in front of it and put an adjustable bias voltage between the filament wire and the target 28-Dec-19 03:45 AM then poke a hole in the target and see how the electrons spray out from it as you wibble everything around electrically/geometrically 28-Dec-19 03:45 AM playing with simple free electrostatics solvers like FEMM might be an enjoyable exercise, and there's a link to a book on charged particle optics in #resources iirc 28-Dec-19 05:06 AM For filiment heater I want to use some electrical circuit 5 volt 2 amp it’s okay . @qualia 28-Dec-19 05:09 AM ohm's law, and in particular how the resistance of a wire changes with temperature, will do you a lot of good here 28-Dec-19 05:09 AM (the lazy experimentalist answer is 'find a 5 volt incandescent lightbulb and carefully smash the outer glass envelope', but concretely knowing the principles behind it all is important, especially if you plan to work with any high voltage) 28-Dec-19 05:25 AM heh, I did that just yesterday 28-Dec-19 05:25 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191227_234220-520E2.jpg 28-Dec-19 05:25 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191227_234224-CA9E6.jpg 28-Dec-19 05:25 AM got like 20 mA of anode current before the solder melted 28-Dec-19 05:25 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191228_000557-5480C.jpg 28-Dec-19 05:26 AM ooo 28-Dec-19 05:33 AM if there is any free time today I will try a triode 28-Dec-19 10:38 AM Xd 28-Dec-19 02:25 PM oohh neat! 28-Dec-19 02:30 PM Thanks 28-Dec-19 02:30 PM I just need to find a way to bond the metals better, soldering is meh 28-Dec-19 02:31 PM spot welding! 28-Dec-19 02:31 PM ...without having to build a spot welder 28-Dec-19 02:31 PM short a battery in a pinch 28-Dec-19 02:32 PM spot welders are easy 28-Dec-19 02:32 PM old MOT re-wound on the secondary 28-Dec-19 02:32 PM :P 28-Dec-19 02:32 PM and a variac if you want to adjust the power output 28-Dec-19 02:33 PM I know, but that turns the triode into less of a quick and dirty project 28-Dec-19 02:33 PM I thought about brazing 28-Dec-19 02:34 PM could always crimp 28-Dec-19 03:00 PM Rewound mot doesn't have the rise time to weld tungsten wire very well or at all really 28-Dec-19 03:00 PM Just kinda ablates it 28-Dec-19 03:00 PM You pretty much need cap discharge 28-Dec-19 03:07 PM I've had some success with a rewound mot 28-Dec-19 03:07 PM Using only one half cycle and double pulsing 28-Dec-19 03:14 PM I've relief heavily on wrapping wires for fast and easy connections lol. Not the best, but it gets the job done easy 28-Dec-19 03:15 PM yea wirewrapping is a great electrical connection actually 28-Dec-19 03:15 PM just have to use square pins 28-Dec-19 03:16 PM I use it on the feedthroughs often on both sides, which are all round lol. Again, not the greatest but it works 28-Dec-19 03:25 PM ah yea... then its not a great connection but will work if both the pin and the wire is super clean 28-Dec-19 03:25 PM if you made a PCB though that went from the pins on your pass through to square wire-wrap pins you'd have some great connections 28-Dec-19 03:25 PM Like remember, back in the day they would prototype entire custom ASICs at bascially full speed using TTL on massive wire-wrap boards 28-Dec-19 03:25 PM https://pbs.twimg.com/media/CK2iCDgWcAUA14d.jpg 28-Dec-19 03:25 PM Good example, this is the original Amiga computer prototype 28-Dec-19 03:27 PM One of my feedthroughs came with a bunch of simple but great connectors for the feedthroughs. Small cylinders drilled out, and uses set screws for attaching to the pin on one side and wire on the other 28-Dec-19 03:27 PM each stack of boards you see there is a chip they later had fabbed 28-Dec-19 03:27 PM stuff is extremely reliable 28-Dec-19 03:27 PM ahhhh ok I see 28-Dec-19 03:27 PM you could still make a PCB that has big round pins to go to the set screw things on the chamber side and then wire-wrap on the other if you are using smaller wires, but I mean your clearly getting work done so its probably not necessary 28-Dec-19 03:29 PM Actually pretty typical connection I have seen for a bunch of vacuum instrumentation on multi feedthrough systems 28-Dec-19 03:29 PM Especially since a lot of the connections are stiff stainless wires for both connection and structural support 28-Dec-19 03:43 PM yea 28-Dec-19 03:43 PM Especially since the chamber is generally grounded and as such you don't want to use for support without some insulation and ceramics are fragile 29-Dec-19 02:23 AM https://gist.github.com/nmz787/9ef47851c79d84f4d05aabc2c4d282e6 29-Dec-19 02:23 AM default behavior is to simply print the combined piezo+pirani pressure to the terminal, but it's rigged to be useful as a library 29-Dec-19 02:23 AM hardest part was copy-pasting from the 901p manual, and getting my sensor wired up for testing 29-Dec-19 02:23 AM added the baudrate check code because, I couldn't tell.... (turned out to be factory default setting, and issue was wiring) 29-Dec-19 02:23 AM actually the 901p manual has a typo (re getting the current baudrate), at least one version I have anyway... so that was fun 29-Dec-19 02:23 AM so FYI, be on the lookout for that sort of thing 29-Dec-19 02:23 AM also, I've only tested this code on linux and Python 3, but it should work on Windows too (though the -find_baud function only on Python 3.3+) 29-Dec-19 04:48 AM Good morning 29-Dec-19 04:48 AM I'm looking about the cooling temperature of diffusion pump walls 29-Dec-19 04:48 AM Here in Chile is summer now and water temperature is around 37C 29-Dec-19 04:48 AM Some sites recommend not exceeding 25C 29-Dec-19 04:48 AM Other sites recommend operating between 45-55C 29-Dec-19 04:48 AM I'm installing a water chiller now and I can operate at 10C if I want. But I dont know what is the optimum temperature for 704 oil 29-Dec-19 04:48 AM I dont trust my chinese vacuum sensor 29-Dec-19 09:55 AM Isn't python < 3.5 or something EoL anyway? 29-Dec-19 09:55 AM (With the exception of zombie 2.7) 29-Dec-19 10:38 AM No only python2 is eol 29-Dec-19 10:38 AM Technically i used python3.7 last night... 29-Dec-19 11:00 AM https://python-release-cycle.glitch.me/ 29-Dec-19 11:06 AM Yeah but that's not the same as EOL 29-Dec-19 11:06 AM EOL means no more security patches 29-Dec-19 11:08 AM https://devguide.python.org/devcycle/#end-of-life-branches 29-Dec-19 11:09 AM Interestingly those dates don't align with the actual final releases, in at least one case https://www.python.org/downloads/release/python-337/ 29-Dec-19 11:09 AM But right on, I usually use the latest anyhow 29-Dec-19 11:09 AM My point on 3.3 was the subprocess timeout feature didn't exist before then, according to what I read last night 29-Dec-19 11:09 AM And I used that to kill serial connections that were blocking, during the baud rate test loop 29-Dec-19 11:10 AM It seems plausible that they might not push a last patch on the same day as the planned eol 29-Dec-19 11:11 AM i've cleaned up the trivac d25e -- the ebay listing said 230V but it doesn't actually have power labeled anywhere on it itself. the manual specifies both 230V and 110V, anyone know how to validate it would be okay at 110? 29-Dec-19 11:11 AM @nmz787 nice gist! just received the MKS 901P as well, will try it out 29-Dec-19 11:18 AM Cool, hope it works out for you 29-Dec-19 11:18 AM I'm no expert, but it seems to me starting with 110 would be safe, and if it doesn't work, move to 220 29-Dec-19 11:21 AM cool 29-Dec-19 11:22 AM The motors are interchangeable on them to an extent, so it could be a 220 motor 29-Dec-19 11:22 AM But it might start on 110 29-Dec-19 11:30 AM ahh 29-Dec-19 11:45 AM oh no. i just placed 12V on pin5 (analog output +) instead of pin3 (VCC) on the MKS 29-Dec-19 11:49 AM RIP analog out 29-Dec-19 11:49 AM hopefully the rs232 connection still works 29-Dec-19 11:49 AM (or you got very lucky) 29-Dec-19 11:54 AM we shall see 29-Dec-19 12:29 PM don't think i have a real 232 transceiver so will need to level shift - hopefully -5 to 5V should be fine 29-Dec-19 03:57 PM anyone have a reading of the analog out of their MKS 901P in atmosphere? 29-Dec-19 04:03 PM I could get one in a few minutes 29-Dec-19 04:05 PM i actually do believe the analog output may still work -- i tried throwing it into a very small vacuum from my cheap amazon pump and it did adjust slightly and somewhat correlates with the output i'd expect, except there's too much noise to confirm (I don't have a DB15 connector and am just breadboarding everything right now) 29-Dec-19 04:05 PM https://samy.pl/s/ukftnmpo1ngp7gq/MSO5074_20191229-160439.png ~155kHz variation of 50mV so way too much to be usable -- i'll check it properly with differential line 29-Dec-19 05:27 PM Hey. Do yo clean you vacuum chamber everytime you are going to use it? 29-Dec-19 05:27 PM Cleaning is a necessary step? 29-Dec-19 05:33 PM Depends on your process and what you are doing. For my setup, I always keep it closed off when not in use. I don't really clean it besides maybe wiping it down occasionally with isopropyl, or acetone followed by isopropyl if I'm reaching far inside fixing up some thruster alignment, but I only go down to mid 10^-6 Torr at most. I can afford to run my system a bit "dirty" though since pumping speed is quite high and my process doesn't produce a ton of contamination. So far the 705 diff pump oil with water cooled baffle seems to eliminate any oil backstreaming so that's not even an issue really as well. 29-Dec-19 05:38 PM Im using 704 oil. I made a baffle myself. But I think back streaming is contaminating the chamber and outgassing 29-Dec-19 05:38 PM @samy it should peg the analog out at the maximum in air 29-Dec-19 05:38 PM I believe it's 9V 29-Dec-19 05:38 PM 155kHz at 50mV is almost definitely power supply noise 29-Dec-19 05:39 PM I reach 0.3 Pa when I clean the chamber 29-Dec-19 05:39 PM that is still foreline pressure 29-Dec-19 05:39 PM leaky foreline pressure 29-Dec-19 05:39 PM have you done anything we've told you to do? 29-Dec-19 05:39 PM checking whether your pump reaches lower by itself, leak testing your chamber, removing all silicone 29-Dec-19 05:40 PM Maybe the mechanical pump oil is outgassing? 29-Dec-19 05:40 PM connect the mechanical pump directly to your gauge and let it run for a few minutes 29-Dec-19 05:42 PM Yeah that's very high if you have the diff pump on. That's a massive leak. I ran my diff pump with a failing roughing pump at way higher than ideal foreline pressure and still cranked down to 10^-6 Torr levels 29-Dec-19 05:42 PM he's been having this massive leaks for a while now, but tends to skip on the whole troubleshooting part 29-Dec-19 05:42 PM I made many improvements. I eliminated almost all the silicone, welded again some joints and use a large viton oring. Now I reach 0.3 Pa instead of 0.6 Pa 29-Dec-19 05:43 PM that is still a big leak 29-Dec-19 05:43 PM With or without the diff pump on? 29-Dec-19 05:43 PM without the diff that is good 29-Dec-19 05:43 PM with the diff that's awful 29-Dec-19 05:44 PM Yeah lol. That would be a great foreline pressure, but a diff pump should hit high vacuum levels even with super high backing levels 29-Dec-19 05:44 PM also, quick question @chucrut 29-Dec-19 05:44 PM what vacuum gauge are you using? 29-Dec-19 05:44 PM I'm using a pirani gauge from china 29-Dec-19 05:44 PM With diff pump on 29-Dec-19 05:45 PM you know piranis max out around that range, right? 29-Dec-19 05:45 PM This pirani gauge max is 1 atm 29-Dec-19 05:45 PM in vacuum maximum is the other way :P 29-Dec-19 05:45 PM https://i.spirit.re/dArnv.png 29-Dec-19 05:45 PM your gauge might just be maxed out 29-Dec-19 05:45 PM ~0.01Pa is very close to 0.6Pa, that might just be within error with a cheap Chinese gauge 29-Dec-19 05:48 PM You mean 0.3 pa is near pirani max? 29-Dec-19 05:48 PM You mean 0.3 pa is near pirani max? 29-Dec-19 05:48 PM yes, within error. 29-Dec-19 05:48 PM You are right 29-Dec-19 05:48 PM especially if it's cheap pirani 29-Dec-19 05:48 PM you might have outgrown your vacuum gauge :P 29-Dec-19 05:49 PM I'm thinking a easy way to know where I am 29-Dec-19 05:49 PM Maybe if i make aluminium coating means I'm good 29-Dec-19 05:49 PM .3 Pa is only 2x10^-3 Torr, pirani should go to higher vacuum than that 29-Dec-19 05:50 PM cheap uncalibrated pirani might not 29-Dec-19 05:50 PM does the reading vary noticeably? @chucrut 29-Dec-19 05:50 PM or does it just reach a minimum and stop 29-Dec-19 05:51 PM Still a pretty basic technology, I would say it would probably be more a bad gauge than a limit to the gauge itself in this case 29-Dec-19 05:51 PM I think calibration is an issue 29-Dec-19 05:51 PM https://www.ebay.com/itm/Inficon-BPG400-I-353-514-Pirani-Gauge-BPG-400-354-490-Sensor-used-5475/263597465111? 29-Dec-19 05:51 PM grab something like this 29-Dec-19 05:51 PM the BPG400 is a wide range gauge, despite what the seller says 29-Dec-19 05:52 PM Wide range gauges are ideal if you can get them. I use a similar wide range and it's insanely convenient lol 29-Dec-19 05:52 PM atmospheric to 5x10^-10 mbar(3.8x10^-10 torr) 29-Dec-19 05:52 PM auto switching 29-Dec-19 05:52 PM and it talks RS232! 29-Dec-19 05:53 PM Yeah 29-Dec-19 05:53 PM I went to China and saw many used pirani gauges. I didnt bought because there is no replacement for the filaments 29-Dec-19 05:53 PM pirani gauges are only good for low to mid vacuum 29-Dec-19 05:53 PM you need a wide range gauge or a set of different gauges for going from mid to high 29-Dec-19 05:55 PM Thats a nice combo for a nice price 29-Dec-19 05:55 PM What's the vacuum level you can get with just your roughing pump? 29-Dec-19 05:55 PM Turning a broken bulb on might be quick test to know the vacuum range 29-Dec-19 05:56 PM a broken bulb won't do much at foreline pressure 29-Dec-19 05:56 PM I reach 10 Pa with the mechanical pump 29-Dec-19 05:56 PM it will only burn out if there's a really bad leak 29-Dec-19 05:58 PM Higher than ideal but plenty for a diff pump 29-Dec-19 05:58 PM Is it rated for the diff pump backing speed? 29-Dec-19 05:58 PM but given that you go from 10 Pa down to 0.6Pa and stop, I'm going to guess you're just maxing out your pirani 29-Dec-19 05:58 PM if the diffpump goes to 0.6, it should also get to 0.06 very quickly 29-Dec-19 05:59 PM Yeah, if it drops like that but stops it could be the gauge 29-Dec-19 06:07 PM Because my next step is generate 20kv 29-Dec-19 06:07 PM If the vacuum is bad, I think I will have sparks 29-Dec-19 06:07 PM I hope is only the pirani 29-Dec-19 06:16 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20191229_231533-C3472.jpg 29-Dec-19 06:16 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20191229_231542-05704.jpg 29-Dec-19 06:16 PM Chinese Pirani 29-Dec-19 06:16 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/EVDL-6_Instruction_Manual-DC44B.docx 29-Dec-19 06:16 PM Maybe this sensor is crap 29-Dec-19 09:19 PM Is that silicone? 29-Dec-19 09:41 PM Sure looks like it 29-Dec-19 10:24 PM turned a pseudo KF16 to barb just to test -- the trivac doesn't do anything at 110 (tries to move the motor but can't make it), 220 does the trick 29-Dec-19 10:24 PM wonder what's different in the 110 vs 220 models as would be nice to change but not a big deal 29-Dec-19 10:24 PM assuming it's just the motor 29-Dec-19 10:32 PM Just the motor, yeah 29-Dec-19 10:32 PM @samy the motor might just need to be re trapped. There should be a small box on the side probly where the cable goes in where you might be able to change the winding taps 29-Dec-19 10:32 PM @AdamMcCombs ahh nice, i'll check 29-Dec-19 10:32 PM It's the difference between running the windings in the motor in parallel or series 29-Dec-19 10:54 PM i don't think the windings of the 220 motors can handle the 110 current that is necessary, can they? 29-Dec-19 10:54 PM if he is not sure which motor style his pumps have the 220 might be the best option 29-Dec-19 11:26 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20191229_232525-2EAE6.jpg 29-Dec-19 11:26 PM 11.3 torr according to the mks 901p, about 3.5ft tall from bottom of pipe to top of salad bowl 29-Dec-19 11:26 PM Drilled a 3/4" hole in the PVC and self-tapped the kf to threaded adapter in, no sealant 29-Dec-19 11:26 PM Salad bowl has a few rubber stoppers in it, sealed with some sort of (polymer?) clay (it's still malleable) 29-Dec-19 11:26 PM Bottom is a bell jar base plate, with a sheet of rubber that it came with, with some closed cell foam gasket material from auto store in between it and the PVC pipe, which was rough cut with a table saw and sanded with electric sander 29-Dec-19 11:26 PM Salad bowl has same gasket material between pipe and it 29-Dec-19 11:26 PM Along with loctice ea 1c (torr seal equivalent) keeping the gasket material on the PVC 29-Dec-19 11:26 PM Well, at least I think the gasket material is closed-cell :p 29-Dec-19 11:26 PM The white piece near the rim is just to add support for the black gasket material 29-Dec-19 11:26 PM I think there's silicone in the gasket sandwich somewhere too, the kind that doesn't emit acetic acid 29-Dec-19 11:53 PM alright finally got rs232 analog translator working 29-Dec-19 11:53 PM @nmz787 your tool working nicely (macos), 7.200E+2 29-Dec-19 11:53 PM didn't entirely blow up the 901 29-Dec-19 11:55 PM Sweet! 29-Dec-19 11:55 PM Sorry I couldn't get you a multimeter reading 29-Dec-19 11:55 PM no worries 29-Dec-19 11:55 PM just going to test this in vacuum to make sure it's working, and hopefully later this week i'll build a differential adc to test if i killed the analog output or not 29-Dec-19 11:55 PM anyone use delrin for flanges for vacuums or should i stick to aluminum? 29-Dec-19 11:58 PM I went a bit overkill and hooked mine to a first-gen raspberry pi, then threw on this LCD 1602 that I had... Both have just been shelved for years waiting for a project... Soooo, here's their time to shine I guess 30-Dec-19 12:01 AM It's all about the vacuum you are trying to hit for your process. What's this build for? 30-Dec-19 12:07 AM right now just going to freeze dry some food...then when i get turbomolecular pump, sputtering, perhaps fusor 30-Dec-19 12:08 AM For freeze drying delrin is fine 30-Dec-19 12:08 AM Fusor is to hot and operates much better in a clean vacuum so stick to aluminum 30-Dec-19 12:09 AM ok cool 30-Dec-19 12:11 AM Delrin might not like being in the cold trap though 30-Dec-19 12:13 AM ahh ok. just seeing if i can save time on turning flanges 30-Dec-19 12:24 AM hmm, put MKS 901P in chamber on my weaker pump - cheap gauge says it went down -80kPa, the 901P output went from 7.200E+2 to 7.197E+2 but it should really be at ~120 i assume, or am i calculating that wrong 30-Dec-19 12:25 AM My chamber says -98kPa and mks says 11 torr 30-Dec-19 12:26 AM ok so i'm calcing this wrong 30-Dec-19 12:27 AM Or the mks is indeed toast :/ 30-Dec-19 12:28 AM i'm not sure how to get -98kPa to 11 torr 30-Dec-19 12:28 AM Squirting isopropanol right now at the automotive gaskets and my pressure is about to drop to single digit torr 30-Dec-19 12:28 AM @samy http://www.endmemo.com/sconvert/kpatorr.php 30-Dec-19 12:28 AM Then add 760 to the negative torr number 30-Dec-19 12:31 AM ahh, so 25 as opposed to 11, guessing that's close enough...guess this might be busted 30-Dec-19 12:31 AM will see if i can get to pcb inside 30-Dec-19 12:34 AM I was able to see mine fluctuate just by putting some plastic over it, and then pressing my thumb on the plastic over the sensor hole 30-Dec-19 12:34 AM Plastic not needed, just to protect and prevent oil contamination 30-Dec-19 12:34 AM Since they're supposed to go up to 3000 torr 30-Dec-19 12:34 AM https://youtu.be/UGp-CQq0qbM 30-Dec-19 01:09 AM What pump are you using for that testing? 30-Dec-19 01:09 AM If it's the one for the Asher I would be really nervous about that 30-Dec-19 01:10 AM Yeah, it's got fomblin in it 30-Dec-19 01:10 AM Trivac 30-Dec-19 01:11 AM Oh yeah I wouldn't use it with this big of a leak 30-Dec-19 01:11 AM Nervous why? 30-Dec-19 01:11 AM It vaporizes a lot of oil 30-Dec-19 01:11 AM Yeah I can see that! 30-Dec-19 01:11 AM Can be really expensive 30-Dec-19 01:11 AM Smells like burning crayons 30-Dec-19 01:11 AM It's 20 year old oil anyway 30-Dec-19 01:11 AM Hydrocarbon I don't care 30-Dec-19 01:11 AM It also destroys mist filters to do this 30-Dec-19 01:12 AM If it mists off, just pushing them to change the oil 30-Dec-19 01:12 AM Hmm 30-Dec-19 01:12 AM I mean it's a 1000 dollar oil change 30-Dec-19 01:12 AM Yeah 30-Dec-19 01:12 AM Probably $500 30-Dec-19 01:12 AM But yeah 30-Dec-19 01:12 AM And fomblin can be filtered and reused 30-Dec-19 01:12 AM It's service life is unbelievably long 30-Dec-19 01:13 AM Right, i remember that now, but you need a lot of it to send it to a place to get it distilled 30-Dec-19 01:13 AM The place I got all my oil fr recently mentioned they do that 30-Dec-19 01:13 AM Some pumps even have a built in filter 30-Dec-19 01:13 AM And circ oil through it 30-Dec-19 01:14 AM Hmm, well i guess we'll first hit those gaskets with silicone grease and see what happens 30-Dec-19 01:14 AM Also don't recommend that 30-Dec-19 01:14 AM You don't want to contimate the asher 30-Dec-19 01:15 AM We're anyways trying to deposit a silane 30-Dec-19 01:15 AM Isn't the grease gonna have a way lower vapor pressure than this pumps ultimate? 30-Dec-19 01:15 AM Doesn't matter 30-Dec-19 01:15 AM They will still outgas 30-Dec-19 01:15 AM Do you have another pump that's not the Asher? 30-Dec-19 01:16 AM Maybe, not sure 30-Dec-19 01:16 AM It's just right there tho 30-Dec-19 01:17 AM Yeah but it's expensive if it goes south 30-Dec-19 01:17 AM There's the scroll pump on fib 2 30-Dec-19 01:17 AM Mmm, idk if silicone in the asher would be bad tho, it's already glass chamber 30-Dec-19 01:17 AM And inductively coupled 30-Dec-19 01:17 AM Seems like if anything, just another layer of glass?? 30-Dec-19 01:18 AM Yeah but on the thing you are ashing 30-Dec-19 01:18 AM I've seen it called out in a lot of ashers sop as well 30-Dec-19 01:18 AM Also there's the concern of introducing things into a pump that does oxogen service 30-Dec-19 01:18 AM Cough namely the alcohol 30-Dec-19 01:19 AM Hehe, dang, I heard to use alcohol in here just a few days ago! 30-Dec-19 01:19 AM Guess I could have tried water, but that also has oxygen 30-Dec-19 01:20 AM Yeah but like 30-Dec-19 01:20 AM Not with oxogen 30-Dec-19 01:20 AM We're planning to introduce water in this vac chamber as part of the reaction 30-Dec-19 01:20 AM Yeah 30-Dec-19 01:20 AM That's all fine 30-Dec-19 01:20 AM It's just the one pump you're using 30-Dec-19 01:21 AM The plasma is just residual oxygen 30-Dec-19 01:21 AM And it ashes carbon all the time 30-Dec-19 01:21 AM What's your concern with oxygen service? 30-Dec-19 01:21 AM Wait you don't feed it pure o2? 30-Dec-19 01:21 AM Nope 30-Dec-19 01:21 AM Oh 30-Dec-19 01:21 AM That's what that thing is made for 30-Dec-19 01:21 AM And why you then need to use fomblin on it 30-Dec-19 01:21 AM Hm 30-Dec-19 01:22 AM Well, my fib also uses fomblin, but it only came with a carbon GIS 30-Dec-19 01:22 AM And option for tungsten 30-Dec-19 01:22 AM No fluorine 30-Dec-19 01:23 AM Yeah but that's there for a different reasons as well 30-Dec-19 01:23 AM Namely low backstreaming 30-Dec-19 01:23 AM Well couldn't that be why the asher uses it too? And since it is pulling on atmosphere oxygen 30-Dec-19 01:23 AM Less chance of any issues, longer work life? 30-Dec-19 01:23 AM I'm not sure but that outside fib might still be using that scroll pump every hour or so 30-Dec-19 01:23 AM IDK 30-Dec-19 01:25 AM I mean kinda? 30-Dec-19 01:25 AM If you're running a gas load on the rotary pump back streaming is not a concern 30-Dec-19 01:25 AM Also it's when you get into high concentrations of oxogen that you have a problem 30-Dec-19 01:25 AM Low partial pressure o2 doesn't desorb into the pump oil like 100% o2 30-Dec-19 01:25 AM There are systems that use nitrogen dilution to advoide having to use fomblin, but hierarchy of controls says using fomblin is inheritly safer than a different more complex engineering control 30-Dec-19 01:29 AM Well the loss via mist might be enough of a concern re cost to change pumps, will have to see what patrick says 30-Dec-19 01:29 AM And silicone contam 30-Dec-19 01:30 AM Do you just have a beater pump somewhere? 30-Dec-19 01:30 AM I thought you had a rotary vaine or something 30-Dec-19 01:30 AM I've got one I use here at home for evacuating food for storage once in awhile 30-Dec-19 01:30 AM But don't feel like donating thst 30-Dec-19 01:30 AM Surplus gizmos has some Alcatel fomblin pumps for like $300 30-Dec-19 01:30 AM Which are tested to like 30 microns 30-Dec-19 01:31 AM If there's going to be a place in the us where you can get a cheap vacuum pump locally it's going to be exactly where you are right now 30-Dec-19 01:31 AM They're as big as my fib rough pump tho 30-Dec-19 01:31 AM Which is twice as big as the trivac 30-Dec-19 01:32 AM Well that large of a chamber you might like it 30-Dec-19 01:32 AM Hmm 30-Dec-19 01:32 AM Yeah 30-Dec-19 01:32 AM Mist would still be an issue of cost to replace tho, but if silicone grease seals it up, i guess that would be less problematic 30-Dec-19 01:33 AM Yeah if you don't have any leaks it's not a problem 30-Dec-19 01:34 AM Another issue with size is I think we're gonna haul this outside to run the reaction, at least that was suggested when i asked if we'd run the reaction with the pump in the fume hood with exhaust blower on 30-Dec-19 01:34 AM Just makes lugging a small bit more work 30-Dec-19 01:34 AM Not a ton 30-Dec-19 01:34 AM Wait what is this reaction going to produce? 30-Dec-19 01:35 AM HCl 30-Dec-19 01:35 AM But probably micrograms 30-Dec-19 01:35 AM Uh 30-Dec-19 01:35 AM Oh 30-Dec-19 01:35 AM Ok 30-Dec-19 01:35 AM Or milligrams 30-Dec-19 01:35 AM Mmmmmm 30-Dec-19 01:35 AM Probably fine? 30-Dec-19 01:35 AM Probably 30-Dec-19 01:35 AM Exhausting into a fume Hood is pretty common 30-Dec-19 01:35 AM I was even thinking just routing the rough pump exhaust through a bed of NaOH 30-Dec-19 01:35 AM Or baking soda 30-Dec-19 01:36 AM I just stick a hose on the output and direct that into the hood 30-Dec-19 01:36 AM For certain levels of hazard that is 30-Dec-19 01:37 AM Problem is reagent is not good to breathe, since it reacts with hydroxyls (which water has, which your lungs have)... So if it isn't all reacted for.some reason when we break vacuum inside...... 30-Dec-19 01:37 AM Oh yeah assume that 30-Dec-19 01:38 AM And this chamber is way too big/akward to load and then place into the hood 30-Dec-19 01:42 AM Whats the reason for the size of the chamber? 30-Dec-19 01:42 AM Drift distance? 30-Dec-19 02:00 AM No, the sheet metal we need to coat is 24" x 25" 30-Dec-19 02:00 AM Contacted a vacuum oven manufacturer that's local, sells to botanical/herbal product producers... They wanted like $20k 30-Dec-19 02:00 AM This PVC was $60 on Craigslist 30-Dec-19 02:00 AM Plus the vac oven was like 2 or 3 inches too small 30-Dec-19 02:00 AM Figuring if the PVC offgassing interferes with the coating process, we can just try spraying some silicone sealant all over the inside to cover it up 30-Dec-19 02:06 AM Ah ok 30-Dec-19 02:06 AM The silicone sealant thing is very optimistic 30-Dec-19 02:06 AM There's some spray on vacuum sealants that might work though 30-Dec-19 02:48 AM Lemme know if you can recall any names on that! 30-Dec-19 11:24 AM Hey, any chemist would know if I can melt NaSO4 into IPA (isopropyl) alcool as easy as in methanol ? 30-Dec-19 11:24 AM I meant NaBH4 30-Dec-19 11:37 AM What are you trying to do? 30-Dec-19 11:37 AM NaBH4 won’t react the same way with 2-propanol as methanol 30-Dec-19 11:42 AM I need to cook a blackening bath for developed & bleached silver halides holograms plates 30-Dec-19 11:42 AM The bath will have to turn silver-halides ( AgBr ) into silver metal on the outer surface of my gelatin émulsion. 30-Dec-19 11:48 AM Ah, hmmm 30-Dec-19 11:48 AM Why can’t you use methanol? 30-Dec-19 11:48 AM Assuming you’d planned on using it at some point 30-Dec-19 11:50 AM Well methanol I have to order on eBay. IPA I have like 8L remaining stock at home 30-Dec-19 11:54 AM And in this case I’m imagine you probably need fairly good purity. 30-Dec-19 11:55 AM Yes to avoid pollution on my fringes structure or to avoid unwanted opaque précipitations in the emulsion 30-Dec-19 12:00 PM Ok, otherwise there were a few decent technical grade sources I could recommend 30-Dec-19 12:01 PM Okay where is this ? 30-Dec-19 12:02 PM Where is what? 30-Dec-19 12:03 PM Décent Sources 30-Dec-19 12:04 PM You will get different results as methanol like @Addison-110m said. In methanol you get hydrogen evolution and a borate-salt thingy, you won’t get this with IPA. NaBH4 will dissolve in IPA, source I found says 8.8 g/L at 60 °C 30-Dec-19 12:10 PM Okay thanks for your advice 30-Dec-19 12:17 PM Heet gas line antifreeze is almost pure methanol and then one variety of klean strip denatured alcohol is a ~50:50 ethanol methanol blend 30-Dec-19 12:26 PM Any equivalent sold on French market ? 30-Dec-19 12:30 PM @Black Lemming go to the auto parts store and ask for gasoline drier 30-Dec-19 12:30 PM Or gasoline antifreeze 30-Dec-19 02:19 PM took pics of the MKS 901P PCBs if anyone is curious https://samy.pl/mks901p/ 30-Dec-19 02:19 PM will get some better ones once home as i want to trace out the analog output path 30-Dec-19 02:22 PM no luck with it after the 12V misadventure? 30-Dec-19 02:23 PM wonder what that HL-Planartechnik sensor is 30-Dec-19 02:23 PM looks like it's the pirani? 30-Dec-19 02:23 PM very crudely cut 30-Dec-19 02:24 PM i finally got talking to it over RS232 (don't have any converters) but it didn't seem to output correct torr -- it would respond 720, but when i put it in a small vacuum (-80kPa on a cheap gauge), it only went down to 719.7torr 30-Dec-19 02:25 PM that makes it probably very dead 30-Dec-19 02:25 PM at least they are fairly inexpensive at the moment 30-Dec-19 02:25 PM Spirit VPS028 is pressure sensor 30-Dec-19 02:25 PM I'm aware, there's two in there 30-Dec-19 02:25 PM the exposed can is likely the piezo, the other is probably the pirani 30-Dec-19 02:28 PM did this patent expire today? https://patents.google.com/patent/US5557972A/en 30-Dec-19 02:28 PM It expired in 2014 30-Dec-19 02:28 PM looks like it 30-Dec-19 02:29 PM Yeah the today's date thing just indicates what it's current status is 30-Dec-19 02:29 PM makes sense, odd way to display it 30-Dec-19 02:29 PM anyway that mentions the sensor 30-Dec-19 02:30 PM interesting, there's basically no info about this company online 30-Dec-19 02:30 PM Well, guess who just got some superconductor and an RF gen from Germany :P 30-Dec-19 02:30 PM HL-Planartechnik GmbH 30-Dec-19 02:30 PM Mannesmann Hartmann & Braun Prouct Information Sensor Technolgy "VPSO 28 Vacuum Prssure Sensor" Oct 1990. 30-Dec-19 02:30 PM https://new.abb.com/about/history/heritage-brands/hartmann-and-braun 30-Dec-19 02:40 PM i'm guessing the main IC is ADuC8xx 30-Dec-19 03:19 PM yeah 30-Dec-19 03:19 PM it's an ADC with a small brain 30-Dec-19 03:19 PM given that you fried it, it would be interesting to see inside the big can 30-Dec-19 03:19 PM (carefully) 30-Dec-19 03:59 PM i haven't removed the paint but none of the other chips were ADC so figured it would be that - i may still try to resolve but if i can't fix it i'll open up the can - assuming you mean the VPSO28 30-Dec-19 04:00 PM yes 30-Dec-19 04:15 PM cool, if it's permagone i'll def open it up 31-Dec-19 09:29 AM Hello, I'm using a cheap oil for my mechanical pump and I have heavy outgassing and contamination from the pump. In my country is difficult to get a decent quality oil for mechanical pump. Do you think is a good idea to use diffusion pump oil in a mechanical pump? 31-Dec-19 10:09 AM No, you need separate oils for the two 31-Dec-19 10:09 AM You shouldn't need fancy oil though 31-Dec-19 10:16 AM Usually I get 20 pascal with the 2 stage mechanical pump. Today I cooled the pump with water and I got 5 Pascal 31-Dec-19 10:16 AM The mechanical pump oil contaminate the diffusion pump and the chamber 31-Dec-19 10:16 AM I think is because I'm using cheap oil 31-Dec-19 10:16 AM Diffusion pump oil was yellow (same color as mechanical pump oil) 31-Dec-19 10:16 AM And the chamber smell oil 31-Dec-19 10:22 AM that's a creative way to cool it 31-Dec-19 10:22 AM you need an oil trap/baffle after your pump, not cold oil 31-Dec-19 10:22 AM oil should be warm in general 31-Dec-19 10:24 AM Oil baffle is a common thing? 31-Dec-19 10:24 AM Between mechanical and diffusion pumps? 31-Dec-19 10:24 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Eurovacuum-EVD-Series-catalog-2016-E6818.png 31-Dec-19 10:24 AM you shouldn't need one between a mech and a diffpump 31-Dec-19 10:24 AM you do need a baffle after the diffpump though 31-Dec-19 10:24 AM such as this 31-Dec-19 10:24 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/8in-Water-Cooled-Baffle-Resized-9AF86.png 31-Dec-19 10:24 AM notice it's water cooled 31-Dec-19 10:25 AM I have a trap for the diff pump inlet 31-Dec-19 10:25 AM that's all you should need 31-Dec-19 10:25 AM you need to cool both the pump body and the baffle 31-Dec-19 10:26 AM But my problem is the "back streaming" or contamination from the mechanical pump 31-Dec-19 10:26 AM your mechanical pump should be connected to the diffpump, and you won't notice any backstreaming from the mechanical pump 31-Dec-19 10:26 AM Mechanical pump is contaminating the diffusion pump 31-Dec-19 10:26 AM how do you know that? 31-Dec-19 10:27 AM Because diff pump oil is yellow 31-Dec-19 10:27 AM Same as mechanical pump 31-Dec-19 10:27 AM and original diff oil is not? 31-Dec-19 10:27 AM Diff pump oil is clear 31-Dec-19 10:27 AM then you do need a baffle 31-Dec-19 10:28 AM You mean a baffle between mech and diff pumps? 31-Dec-19 10:28 AM yes 31-Dec-19 10:28 AM one thing you can try doing is just cooling the hose 31-Dec-19 10:28 AM might be enough to get it to condense. 31-Dec-19 10:28 AM Right 31-Dec-19 10:28 AM Or making the hose longer 31-Dec-19 10:29 AM that should also work 31-Dec-19 10:29 AM but it's a value vacuum pump 31-Dec-19 10:29 AM refrigeration pumps are generally not good 31-Dec-19 10:30 AM Not good because the they have flow? 31-Dec-19 10:30 AM you want a proper vacuum pump, not for evacuating fridge lines 31-Dec-19 10:30 AM Low flow 31-Dec-19 10:30 AM also tons of mist, low vacuum, quite a low flow yes 31-Dec-19 10:30 AM Okay 31-Dec-19 10:31 AM pick up a second hand scientific vacuum pump 31-Dec-19 10:32 AM I will try to find. I think I need to buy from Ebay and send to Chile 31-Dec-19 10:32 AM leybold, edwards, welch, pfeiffer, alcatel, ulvac 31-Dec-19 10:32 AM any of the brands will do 31-Dec-19 10:33 AM Adding a second pump could help to the final vacuum, but still have the contamination problem 31-Dec-19 10:33 AM a second pump will never be as good as a two stage one 31-Dec-19 10:33 AM No 31-Dec-19 10:52 AM I found this: 31-Dec-19 10:52 AM "One concern using oil-sealed roughing pumps, such as refrigeration pumps, can be the backstreaming from the roughing pump to the diff pump, which can contaminate the diff pump oil. In order to mitigate this, I selected to use a molecular sieve filled replaceable foreline trap. The molecular sieve not only helps prevent oil contamination, but has the added benefit of absorbing water vapor pumped from the diff pump which could in turn contaminate the roughing pump oil" 31-Dec-19 10:52 AM That's one way to do it, yes 31-Dec-19 10:52 AM Good 31-Dec-19 11:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/15778192380617769043070818268609-D9433.jpg 31-Dec-19 11:02 AM There are copper wool traps too 31-Dec-19 11:02 AM Maybe I can buy copper wool here 31-Dec-19 11:14 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/15778199662865563018308290873611-5876A.jpg 31-Dec-19 11:14 AM Zeolite trap 31-Dec-19 11:38 AM Yup, that's a good idea 31-Dec-19 11:38 AM You can replace copper wool with pure fiberglass 31-Dec-19 12:21 PM speaking of pumps.. anything worth mentioning about using a scroll pump as a backing pump to that big ol' turbo I've got? 31-Dec-19 12:27 PM You'd need a great big scroll pump to back your big turbo with enough pumping speed. Finding a used two-stage rotary vane pump will be much cheaper 31-Dec-19 12:28 PM hrmm, can always start with one since I don't have anything hugely specific in mind anyhow. Was trying to not "paint myself into a corner" by going with a dry pump 31-Dec-19 12:30 PM Does your application specifically require a dry pump? 31-Dec-19 12:32 PM Ugh.. I wish the language filter/bot would at least preserve your message when you goof up 31-Dec-19 12:32 PM no, not my initial project, but I would like to mess around with CVD in the future so figured buy once cry once - but at this rate I'll probably wind up with a whole 'other chamber by then 31-Dec-19 12:32 PM my quick-spike project is going to be depositing black phosporus on the tip of optical fibers, then may pursue some MEMs stuff or pzt thin films on fibers 31-Dec-19 12:34 PM Just put fomblin in your rotary vane pump 31-Dec-19 12:35 PM nothing special needed? just swap out the oil for the fomblin stuff and good to go? 31-Dec-19 12:35 PM (e.g. any ol' rv pump will deal if it has the magic oil?) 31-Dec-19 12:37 PM You probably want to rebuilt your pump before you switch oil and clean everything thoroughly. I'd replace the vanes and various seals by using a rebuilt kit just to maintain the pump properly 31-Dec-19 12:37 PM okay, that makes sense 31-Dec-19 12:37 PM But even then it's going to be cheaper than an equivalent dry scroll pump 31-Dec-19 12:37 PM Well I guess it also depends on your luck on eBay and auctions 31-Dec-19 12:38 PM another "issue" I was going for was noise but I have no benchmark even for a rotary vane or similar 31-Dec-19 12:38 PM my workshop has thin walls - so two things, really.. noise for neighbors at wee hours for long processes, and I'm also in Florida so my a/c in the shop only handles so much humidity 31-Dec-19 12:38 PM so wet air, comparatively speaking, I'd venture to say 31-Dec-19 12:39 PM Rotary vane pumps can be very quiet after it gets down to pressure 31-Dec-19 12:39 PM okay - you've got me sold 31-Dec-19 12:39 PM considering they're easily 1/3rd the cost might as well 31-Dec-19 12:40 PM Like 60 dBc or something. I've got two 1/2 hp Welch Direct Drive pumps and they are very quiet when it gets under 20 millitorr or so 31-Dec-19 12:41 PM yea it makes sense that things should diminish 31-Dec-19 12:41 PM okay, gonna go get some work done then come shop for a pump - will probably run it by the room before clicking the buy button 31-Dec-19 12:41 PM saw a couple edwards' on ebay for 500 or so that struck my fancy earlier this week, will have to track them back down 31-Dec-19 12:41 PM been rebuilding that 3-axis feedthrough today btw.. thing is is really good shape mechanically - just dirty and poor choice of fastener material combinations 31-Dec-19 12:50 PM I'm facing the same issue actually... I need a big rotary vane pump to back my big turbo when it handles heavy gas load, but the last thing I need right now is another heavy thing I've got to move around 31-Dec-19 12:50 PM So let me know if you find something at a reasonable price, our turbo pumps have pretty much the same pumping speed 31-Dec-19 12:50 PM I'll probably hold off until I know I need it, so feel free to grab a deal first 31-Dec-19 01:55 PM @Applied_Ion when you said you ganged two MOTs together for your high power gliding arc, that was in parallel? Should I be concerned about matching the microwave wattages? I just got a free 700w unit and i think the one back home is probably 1100 or 1800w. 31-Dec-19 02:03 PM The two I used were identical transformers. The outputs were in series, inputs driven in parallel but you need to make sure the phasing is right so the outputs don't cancel. I'd say you probably want to match wattage, I wouldn't use two that are massively different. I also ballasted the setup using a third as an inductive choke on the primary side. 31-Dec-19 02:03 PM Mind you MOTs are massively dangerous lol, one is bad enough. Two is twice as nasty, so be really careful. 31-Dec-19 02:11 PM Guess i can use this as a ballast then 31-Dec-19 02:11 PM If I get that far 31-Dec-19 02:11 PM corrosive roughing pumps are built differently as-well. and have different rebuild kits 31-Dec-19 02:11 PM (not due to death, lol) 31-Dec-19 02:11 PM though used corrosive rated pumps are about the same price as used non corrosive rated pumps 31-Dec-19 02:11 PM but can be in a lot worse condition... 31-Dec-19 02:11 PM and rebuild kits cost more 31-Dec-19 02:11 PM and well yea oil costs more 01-Jan-20 06:01 AM Sitting here like a factory worker loading up a vibratory tumbler with fasteners then moving to ultrasonic cleaner. Makes me wonder if anyone has tried combining acoustophoresis/holography and ultrasonic cleaning baths. Would be nice just to load up the bath with fasteners and some large grit cerium oxide and have a phased array of small bolt-clamped langevins effectively hover the abrasive into contact with the parts being cleaned so you don't abrade through the bath bottom. Phased array of langevins in general would be nice to sense location of parts and concentrate energy onto them in particular. 01-Jan-20 06:01 AM Wonder how well you could grind optics with such a system. Have it constantly mode hopping to avoid resonance patterns. 02-Jan-20 03:44 AM <__ice9#6039> @nmz787 only put transformers of the same model in parallel. 2 MOTs of any differing types can be used in series, though, by just connecting the chassis grounds together and making sure you have the right primary phasing. 02-Jan-20 03:44 AM <__ice9#6039> For ballast if you have a specific target inductance in mind you can just wind a large toroid. It's important to include the leakage inductances of the primaries involved when calculating though (measure primary with LCR meter with secondary shorted) 02-Jan-20 03:44 AM <__ice9#6039> Depending on level of necessary vacuum, sometimes a PTFE+FFKM diaphragm pump is good enough. I have a KNF Laboport double one that goes to about 10 Torr. Single ones are usually more like 50-100 Torr, not great but still usable for stuff like vacuum distillation. 02-Jan-20 03:44 AM <__ice9#6039> They don't need any oil 02-Jan-20 03:44 AM <__ice9#6039> Also I built a gliding arc torch based on discussions with @Applied_Ion and can confirm the design works well. I do recommend series MOTs though. I only used a single one, so the arc initiation gap at the start of the rails needed to be quite narrow. 02-Jan-20 03:44 AM <__ice9#6039> Ah also: you can build foreline traps yourself pretty easily if there aren't any on sale cheaply at the time. Just using standard flange fittings. 02-Jan-20 10:01 AM sooo i was discussing the cryopump with a friend and he was suggesting that maybe if the helium proves to be too expensive i could try running things on UHP argon 02-Jan-20 10:01 AM is that really an option? 02-Jan-20 10:01 AM seems...like a bad idea 02-Jan-20 10:29 AM No, UHP helium is the only option 02-Jan-20 10:31 AM eh, uhp isn't that critical 02-Jan-20 10:31 AM 4.6 is enough 02-Jan-20 10:31 AM but it has to be He 02-Jan-20 10:48 AM yeah thats what i was thinking but i wanted to believe him heh 02-Jan-20 10:49 AM there are some cryos that work with Ar, but that's linde, not stirling or a variation thereof 02-Jan-20 10:49 AM http://www.mmr-tech.com/mmr_overview.php 02-Jan-20 04:07 PM i had this air line coupler kit at home and am using it for my 2 stage pump atm but can i also use these for higher vacuum? https://www.amazon.com/ColorConnex-Coupler-Piece-Automotive-A72458C/dp/B003TFE7VG/ 02-Jan-20 04:11 PM i'd be wary of those for anything but roughing vacuum use 02-Jan-20 04:11 PM and even still.. unless they're explicitly rated for vacuum use 02-Jan-20 04:11 PM pressure differential's the wrong way around 02-Jan-20 04:26 PM I wouldn't use any quick connects for vacuum at all 02-Jan-20 04:26 PM KF hardware is simple and easy to connect or disconnect 02-Jan-20 04:38 PM ^ 02-Jan-20 04:38 PM the first few months of my vacuum hackering were defined by near constant wrestling with fittings not designed for vacuum usage 02-Jan-20 04:38 PM the quicker you can make everything KF, the less you'll hate yourself later on 02-Jan-20 04:43 PM will do. started turning some KF parts but happened to have these already and were quick to use (and wanted to disconnect everything from something i had pumped out) 02-Jan-20 04:44 PM the moment you stop pumping your vacuum will turn very sour 02-Jan-20 04:44 PM ok 02-Jan-20 04:44 PM i used a ball valve to try to hold the vacuum from the rest of the system 02-Jan-20 04:45 PM high vacuum generally requires constant pumping 02-Jan-20 04:45 PM got it 02-Jan-20 04:45 PM unless you seal in a vacuum tube or something 02-Jan-20 04:46 PM in this case i probably don't need a crazy vacuum, making a CRT 02-Jan-20 04:46 PM i may try sealing it off ultimately 02-Jan-20 04:46 PM CRTs generally run at around 1*10^-4 to -6 mbar throughout their life 02-Jan-20 04:46 PM Absolutely within KF hardware territory, but after it sits for a while it might drop a bit unless gettered(which CRTs are) 02-Jan-20 04:49 PM speaking of which, for connecting to an odd opening (eg a glass bottle), is there a cheap material like a synthetic rubber that i can use to seal and attach an adapter into? like a cork where i could install a custom fitting that turns into a KF16 adapter so then i could go KF from there 02-Jan-20 04:49 PM ahh 02-Jan-20 04:49 PM There are KF to glass adapters 02-Jan-20 04:49 PM i assume Viton would be good but pricey 02-Jan-20 04:50 PM viton is cheap, and yeah that's what's used 02-Jan-20 04:50 PM https://www.idealvac.com/Adapter-KF-25-to-1-18-in-ID-Quick-Coupling/pp/P1010163 02-Jan-20 04:50 PM something like this 02-Jan-20 04:50 PM easy to machine if you have a lathe, it's just a compression fitting 02-Jan-20 04:51 PM so this would go directly over the bottle? (i'm using a vodka bottle with with threaded top) 02-Jan-20 04:52 PM this is used for sealing flat glass tubes 02-Jan-20 04:52 PM and don't worry, i've already used up the vodka 02-Jan-20 04:52 PM so a bottle might not work 02-Jan-20 04:53 PM i'm surprised this would hold well onto a bottle, looks like just friction fit with no other mounting (besides the KF side) 02-Jan-20 04:54 PM It's a compression fitting 02-Jan-20 04:54 PM You slide the glass tube in, then squish the o-ring 02-Jan-20 04:54 PM The outer spinny bit is a nut 02-Jan-20 04:54 PM ohh i see 02-Jan-20 04:54 PM thought it was solid, makes sense, thanks 02-Jan-20 04:55 PM worst comes to it, a flat viton ring and a flat surface will do 02-Jan-20 05:01 PM guess i'll get one of those viton o-ring kits and see if i can make a compression fitting that'll support the threads 02-Jan-20 05:01 PM threads won't work 02-Jan-20 05:01 PM need a flat surface 02-Jan-20 05:03 PM ok, will use another bottle 02-Jan-20 05:13 PM maybe try some chem glassware instead 02-Jan-20 05:13 PM that should work 02-Jan-20 05:13 PM like an erlenmeyer 02-Jan-20 05:16 PM ok 02-Jan-20 05:16 PM for the CRT I'm a little worried about the stability of the bottle as I dremeled a hole in one side and used JB Kwik Weld to attach a nail -- would that be okay to do on a flask or better to heat it up and melt the location where i want to insert the electrode? 02-Jan-20 05:17 PM you could just go all the way and buy some borosilicate tube and make your own everything 02-Jan-20 05:17 PM A dremel would definitely induce serious stress 02-Jan-20 05:17 PM A drill press with a diamond bit would be a bit better 02-Jan-20 05:17 PM But you could totally try experimenting making your own as LRM said 02-Jan-20 05:19 PM if you are planning to have the electrodes going through JB weld, as far as i know, you will absolutely have to have it actively pumped to run it 02-Jan-20 05:19 PM cool, i'll try that 02-Jan-20 05:19 PM ahh 02-Jan-20 05:19 PM also, for high vacuum epoxy, try Hysol 1C 02-Jan-20 05:19 PM It's basically the same as expensive Torr-Seal, except not expensive. 02-Jan-20 05:19 PM glass to metal seals are a really tricky thing from what ive heard but it is mostly a matter of using the right materials 02-Jan-20 05:19 PM but using a borosilicate tube i could just melt the glass over the electrodes and seal it in vacuum? 02-Jan-20 05:20 PM glasslinger on youtube has a ton of tube making videos 02-Jan-20 05:20 PM not quite that easily, but yeah 02-Jan-20 05:20 PM @Deleted User awesome, i'll use that epoxy 02-Jan-20 05:22 PM this guy details sealing wires 02-Jan-20 05:22 PM http://www.randombytes.net/lamps.html 02-Jan-20 05:22 PM nice, thanks! 02-Jan-20 05:22 PM any suggested resources for determining thickness of material (and what material) to use to prevent implosion based on the pressure? i'm going over Weston Ultrahigh Vacuum Practice atm 02-Jan-20 05:24 PM Two rules: 1 - Square things implode 2 - Most glass is thick enough not to 02-Jan-20 05:24 PM if i am thinking of taking that flange off the cryopump to have access to the cold head (to check if it really needs a refill)...what sort of seal might i expect from an ANSI ASA 11" flange? just a huge oring? 02-Jan-20 05:24 PM Just a huge o-ring 02-Jan-20 05:24 PM was thinking that maybe my 10 minute test was not a fair test especially without direct access to the cold head 02-Jan-20 05:25 PM at low pressure you won't get any work done through the head 02-Jan-20 05:26 PM well i still cannot find a manual for the model 21 compressor but i was thinking that if the gauge on the head only goes up to 100psi and is reading around 75psi maybe there actually is enough charge to get it running 02-Jan-20 05:26 PM gauge on the compressor goes up to 300psi but i am assuming the head is the limiting factor 02-Jan-20 05:26 PM Well, it won't hurt to run it low, as long as it's not completely dry 02-Jan-20 05:26 PM Might not get cold enough or go down fast 02-Jan-20 05:27 PM hopefully the oring survives to live another day because i am guessing that size might get expensive heh 02-Jan-20 05:27 PM Be very gentle :P 02-Jan-20 05:28 PM i liked it before the edit haha 02-Jan-20 05:28 PM heh 02-Jan-20 06:43 PM Anyone have first or second hand experience annealing copper gaskets so as to re-use them? Not so much a cost thing as a convenience thing. 02-Jan-20 06:43 PM I've been told it works pretty well 02-Jan-20 06:45 PM Probably going to give it a shot once I get my pumps set up. Ordering new for now but will experiment once I can spare the headache/time of possible troubleshooting. 02-Jan-20 06:48 PM i've done it with lightly-bit-on gaskets (jury's still out) and also brand new gaskets (good idea for viewports; plus they go on butter-smooth) 02-Jan-20 06:54 PM What's the logic behind soft and view ports? Just to ensure the gasket conforms rather than the viewport's metal-glass interface? 02-Jan-20 06:54 PM I need to look in to how those are made. Have a zinc selenide viewport in my future. 02-Jan-20 07:34 PM no luck on the cryo, definitely needs the compressor charged up i think 02-Jan-20 10:51 PM naw, it's just to reduce stresses on the viewport while installing it. less torque needed to bite down into the gasket. at least that's my understanding 02-Jan-20 10:51 PM thorlabs has these really nice conflat viewport mounts that can seemingly take any of their thicker windows in a modular kinda way, they use a captive o-ring i think 02-Jan-20 10:54 PM Here's a pretty neat viewport I got from @Conmega 02-Jan-20 10:54 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-32426.png 02-Jan-20 10:54 PM The glass is held on the inside and sealed with an o-ring 02-Jan-20 10:55 PM ooh 02-Jan-20 11:00 PM It's kinda like the Thorlabs system but I can't find alternative windows to swap out 03-Jan-20 12:36 AM @samy we've used rubber stoppers here for vacuum feedthroughs, just shoved piano wire through them with a drill press 03-Jan-20 12:36 AM @__ice9 will have to read more about connecting transformer secondaries in parallel and series, thanks! 03-Jan-20 12:48 AM evil thorlabs 03-Jan-20 03:37 AM Looking for the optimal oil level in a mechanical pump I found many pictures like this. The optimal level is really low 03-Jan-20 03:37 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/15780516587584552618442403631404-5E735.jpg 03-Jan-20 04:27 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/15780547085202455640681640236745-DE18B.jpg 03-Jan-20 06:58 AM would anyone around here be interested in a SR844 RF lock in amp? got one that as far as i've been able to test it is fully working 03-Jan-20 09:34 AM sure :3 03-Jan-20 10:02 AM @chucrut, oil level and sight glasses is kind of a variable subject 03-Jan-20 10:02 AM best to try to find what the manufacturer recommends 03-Jan-20 10:14 AM @pbx/peterbjornx yeah definitely, depending on price 03-Jan-20 02:11 PM NOON, nmz787: judging at ebay listings, i'd say around 2.5k - 3k though i'm open to negotiations on that. though maybe we should continue this in swap meet. 03-Jan-20 11:17 PM FYI the ubiquitous Rafael software defined radios (e.g. Airspy SDR.. < $200) have been used as a very cost effective and well performing lock in amp. https://aip.scitation.org/doi/10.1063/1.4999552 03-Jan-20 11:17 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_20200104-011650_Drive-1E0A2.jpg 03-Jan-20 11:17 PM One of the Airspy variants https://airspy.com/airspy-r2 there are also various other boards for up/down conversion to expand your band reach. The SDR ecosystem these days is getting very mature. 04-Jan-20 01:30 AM @Metanoic nice! It also references the LPC4370 which I have a soft spot in my heart for, since it has 3 cores (well two are just for really-low level stuff) and an 80 MSPS ADC 04-Jan-20 04:58 AM I connected my rotary pump to a VFD inverter at 220v 70Hz instead 50Hz. The pumping speed increased a little and the motor runs cooler 04-Jan-20 02:02 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200104_190459-1ADB6.jpg 04-Jan-20 02:02 PM Ladies and gentleman. This is a picture of toilet paper. Is good for absorbing water and oil. I think it can be used for oil trap for the rotary pump 04-Jan-20 02:02 PM Is like a very fine mesh 04-Jan-20 02:04 PM Not in the foreline 04-Jan-20 02:04 PM But on the exhaust, yes 04-Jan-20 02:04 PM Cotton also is like a mesh 04-Jan-20 02:04 PM I was thinking in the foreline 04-Jan-20 02:05 PM The foreline traps rely on a different trapping action than the exhaust traps 04-Jan-20 02:05 PM Oil in a mesh like that will still vaporize and flow through it into the chamber because the mesh really doesn't trap it 04-Jan-20 02:05 PM Molecular seives trap the oil on contact with the seive and it doesn't then revaporiz and enter the foreline 04-Jan-20 02:07 PM You mean oil can re-evaporate from this mesh? 04-Jan-20 02:07 PM Trapped and re-evaporated 04-Jan-20 02:07 PM Yes 04-Jan-20 02:07 PM Yeah exactly 04-Jan-20 02:07 PM A sieve won't let it evaporate after it gets captured 04-Jan-20 02:07 PM Which is why they also have a finite resource, after which you have to either replace the seive or wash it 04-Jan-20 02:08 PM The micro pores in the molecular seive are oil molucuel sized 04-Jan-20 02:08 PM Except when they're not 04-Jan-20 02:08 PM So the oil actually gets stuck 04-Jan-20 02:08 PM :P 04-Jan-20 02:08 PM Ok 04-Jan-20 02:08 PM There are oil sized holes 04-Jan-20 02:09 PM The oil does get stuck but there's so much funky physics going on in a sieve 04-Jan-20 02:09 PM Yeah 04-Jan-20 02:09 PM Same as with nitrogen separators, the membranes are not actually nitrogen sized 04-Jan-20 02:09 PM Columb attraction ect ect 04-Jan-20 02:09 PM But for just visualization the oil is actually trapped ish 04-Jan-20 02:10 PM I think an oil sized particle mesh will strangulate the air flow too much 04-Jan-20 02:10 PM It's not a solid mesh 04-Jan-20 02:10 PM Correct 04-Jan-20 02:10 PM It's particles 04-Jan-20 02:10 PM Small spheres 04-Jan-20 02:10 PM The oil gets stuck in the particles while the air passes around them 04-Jan-20 02:10 PM The particles bounce around the spheres as you pump 04-Jan-20 02:11 PM I think an oil sized particle mesh will strangulate the air flow too much 04-Jan-20 02:11 PM Oil touches the surface of one and it gets trapped 04-Jan-20 02:11 PM A solid mesh would, yes. But in a foreline trap it's a bunch of spheres loosely packed 04-Jan-20 02:11 PM "trapped" 04-Jan-20 02:11 PM There's a lot of air between them 04-Jan-20 02:11 PM inside of a foreline trap: 04-Jan-20 02:11 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/710GbFyPsnL-46431.png 04-Jan-20 02:11 PM The air goes between the spheres, the oil gets stuck on(/in) them. 04-Jan-20 02:14 PM I recently tried using this. Is a very fine wire wrapped. The pumping rate slowed down and didn't help to achieve a better vacuum 04-Jan-20 02:14 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/15781762937415904659419548045359-B5202.jpg 04-Jan-20 02:14 PM Yes, it wouldn't do anything 04-Jan-20 02:14 PM The zeolite spheres act as an oil trap, that's what makes it work 04-Jan-20 02:14 PM The media is very important 04-Jan-20 02:14 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/SEM-micrograph-of-zeolite-504B5.png 04-Jan-20 02:14 PM here's what the zeolite looks like up close 04-Jan-20 02:18 PM That's not even the level of detail that shows the oil trapping mechanism 04-Jan-20 02:21 PM This would trap oil 04-Jan-20 02:21 PM But yes the oil goes inside those little holes 04-Jan-20 02:24 PM I'm reading activated carbon also is used in foreline as zeolites 04-Jan-20 02:24 PM Is easier for me to buy activated carbon here 04-Jan-20 02:26 PM It could work 04-Jan-20 02:26 PM Not the pharmacy store kind though, those are pressed tablets 04-Jan-20 06:18 PM I'm having a super hard time identifying the rectangular connectors on these Pfeiffer TCP turbo controllers. Pump side is fine, didn't take long. Controller side, though.. different story especially if I want it latching like "oem" 04-Jan-20 06:18 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200103_205259-A85DA.jpg 04-Jan-20 06:18 PM X5 and X4. I have found stock of them on IdealVac but they want like 150 bucks for a single connector. Cables also go for 200+ so I'm just gonna make my own. Pump side connector is 20awg so no problem on conductors. 04-Jan-20 06:18 PM The connectors themselves I'm assuming are a 32 full pin 04-Jan-20 06:18 PM Based on the spacing differences between the two rows on each connector and the different pin counts 04-Jan-20 06:21 PM those are different than the extra connector i have from the TCP040 but for the X5...you can pretty easily make your own male connector with some thin copper clad board and a dremel 04-Jan-20 06:21 PM at least it worked for me heh 04-Jan-20 06:22 PM Yea worst case I will just replace the connector 04-Jan-20 06:22 PM But would rather find the original. They had Souriau make their cables it seems, as that is what is branded on the pump connector. 04-Jan-20 06:22 PM (and they do cable molds and whatnot) but I failed to find the other end in their current stock/products. 04-Jan-20 06:25 PM do they have the number on them? like the connector like that ive got in my hand has a tiny little part number on it "A12 DIN 41622" 04-Jan-20 06:25 PM wrong size for you but yours probably has a similar part number format 04-Jan-20 06:25 PM https://www.reichelt.com/de/en/Male-Multipoint-and-F-Connectors-DIN-41622/2/index.html?ACTION=2&LA=2&GROUPID=7440 maybe something here...? 04-Jan-20 06:28 PM The male btw https://www.idealvac.com/Pfeiffer-Balzers-TCP-040/pp/P103065 04-Jan-20 06:28 PM I haven't seen anything but am in the process of disassembling to inspect the underside etc 04-Jan-20 06:28 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/TCPMatePlug5000_1-D8D1A.gif 04-Jan-20 06:30 PM i think the plug parts are standard and the cable thing is just a housing 04-Jan-20 06:30 PM The sockets in a + shape is peculiar 04-Jan-20 06:30 PM Yea they are separate pieces. The shell is the unique part 04-Jan-20 06:38 PM All Pheiffer connectors I have so far encountered ware catalog parts, if somewhat rare sometimes. 04-Jan-20 06:38 PM personally...I would just 3d print the shell but that is just me. 04-Jan-20 06:38 PM my connecting cable with copper clad board connectors does not even have a shell...yet 04-Jan-20 06:39 PM Some of their gauges use Molex mPm series. so looking at Molex and Phoenix Contact catalogs in addition to German manufacturers might reveal something suitable 04-Jan-20 06:40 PM that reichelt site seems to have both the housings and connectors btw 04-Jan-20 06:40 PM but only 12/20 pins... 04-Jan-20 06:41 PM Ah, but now you know the series! 04-Jan-20 06:41 PM so you can look on digikey, mouser, arrow, farnell and RS Components! 04-Jan-20 06:42 PM yeah thats why i was mentioning it instead of just linking them, pretty sure it is something very close to the DIN 41622 family 04-Jan-20 06:42 PM https://uk.rs-online.com/web/p/din-41622-connectors/1006245/ ???? 04-Jan-20 06:42 PM think that might be the connector...just need your housing and locking levers now 04-Jan-20 06:46 PM The TE Connectivity EBC-440 maybe 04-Jan-20 06:46 PM I think you're right on the money re: DIN 41622 04-Jan-20 06:46 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/47-305_01-6AC58.jpg 04-Jan-20 06:46 PM Telegartner 04-Jan-20 06:46 PM Owe you a beer @LRM 04-Jan-20 06:51 PM just had one of the 12 pin ones hanging around, glad that keeping it around actually helped heh 04-Jan-20 06:51 PM Now time to get rich making our own cables and undercutting IdealVac by 75% 04-Jan-20 06:51 PM I bet we could sell... dozens. 04-Jan-20 06:52 PM i really wonder if IdealVac really sells much at their asking price at all 04-Jan-20 06:53 PM Yea I've considered the same 04-Jan-20 06:53 PM probably just to universities or places with too much money 04-Jan-20 06:54 PM They likely do 04-Jan-20 06:54 PM We paid 250eur/cable for some to Pheiffer 04-Jan-20 06:54 PM and then had our own manufactured by a subcontractor for under 50eur 04-Jan-20 06:55 PM I made mine for $8 in postage and some crap i had laying around 04-Jan-20 06:55 PM Thank you so much again LRM. I had been searching nearly the entire day. 04-Jan-20 06:55 PM https://i.gyazo.com/c6fe5ab269051b9e261d646792f5195a.jpg 04-Jan-20 06:55 PM @Metanoic happy to help! 04-Jan-20 06:55 PM the $8 in postage was because a friend of mine already had the amphenol connector 05-Jan-20 11:12 AM i'd like to make a 2nd vacuum chamber today for freeze drying (using one as a cold trap) - if i want to see through, is a glass chamber + thick acrylic the best best? would that also be usable with a turbomolecular pump for other projects or is there an alternate suggestion? 05-Jan-20 01:08 PM Are you talking about using a vacuum Bell jar? If so that's fully usable with other projects. A large piece of acrylic likely is not 05-Jan-20 01:11 PM @samy presumably with big enough pumping speed, any leaks through the matrix of the plastic would be taken care of... Figuring out how much pumping you need for a given piece of plastic is a harder question i think 05-Jan-20 01:12 PM Even then that gets next to impossible without differental pumping apuretures really quickly 05-Jan-20 01:12 PM This assumes you want to hit say -6 or 7 torr 05-Jan-20 01:14 PM Lol I saw a freeze drier at the farm store the last time I was there... Was pretty interesting find 05-Jan-20 01:14 PM I doubt they use a turbo 05-Jan-20 01:14 PM I think this was it https://www.amazon.com/Harvest-Right-Freeze-Dryer-Dehydrator/dp/B07H7VVT68/ 05-Jan-20 01:14 PM "This model comes with the standard oil pump" 05-Jan-20 01:14 PM Eew 05-Jan-20 01:33 PM ahh, thanks - is aluminum better than thick acrylic for the base of the jar? 05-Jan-20 04:11 PM Yes, acrylic is often, if not always, completely unsuitable 05-Jan-20 04:41 PM ahh 05-Jan-20 04:42 PM I'm mean -5 range you can probably get away with it 05-Jan-20 04:42 PM But if you are reallllllyyy going to fight to get it that low 05-Jan-20 04:47 PM 10^-5 torr? 05-Jan-20 04:49 PM Yeah 05-Jan-20 04:49 PM And -5 on a turbo is pretty bad 05-Jan-20 04:50 PM ahh 06-Jan-20 07:21 AM https://www.bmisurplus.com/products/16877-amray-inc-1610-scanning-electron-microscope 06-Jan-20 07:21 AM This SEM looks like it's in reasonable condition, but I can't find a lot of info on it. @AdamMcCombs any experience with this? 06-Jan-20 07:21 AM I'm going to call and ask for more details 06-Jan-20 07:21 AM But this is certaintly not a "go in, take it apart in four hours and stuff it into a car" SEM lol 06-Jan-20 07:57 AM huh that place is about 4 hours from me neat 06-Jan-20 07:57 AM You want a 4th SEM? 06-Jan-20 07:57 AM Or is it 3rd? 06-Jan-20 07:58 AM if someone needs help getting something from there and you around here I suppose let me know. 06-Jan-20 07:58 AM lol noooo 06-Jan-20 07:58 AM Unless I had like an abandoned mall 06-Jan-20 07:58 AM although that is a nice looking SEM and its single phase 06-Jan-20 07:58 AM With a turbo and EDS 06-Jan-20 07:59 AM yup 06-Jan-20 08:03 AM need moar sem 06-Jan-20 09:08 AM what is this? 06-Jan-20 09:08 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/16877_4_-C28B5.png 06-Jan-20 09:08 AM I mean, the thing on the left 06-Jan-20 09:08 AM Dewar for the EDS sensor 06-Jan-20 09:08 AM Oh, cryocooling 06-Jan-20 09:09 AM All EDS detectors need cooling, the older styles need LN2 and newer ones can get away with little peltier stacks 06-Jan-20 09:09 AM or well all the ones I am aware of :) 06-Jan-20 09:10 AM Yeah all of them need cooling at least for the amplifier to get the noise down 06-Jan-20 09:10 AM So you could do pulse height discrimination and get sufficient energy resolution 06-Jan-20 09:12 AM I bought a small desktop injection molding machine. Should be fun to play with. 06-Jan-20 10:21 AM Hrm well as a note to everyone... Bolt kits for conflat from Duniway are cheaper than LDS Vacuum it seems and their bolts are silver plated... so yea cheaper and silver plated... And I think you get more bolts... 06-Jan-20 10:21 AM So uh yea no brainer for that though may be worth comparing to other places too. 06-Jan-20 10:21 AM I am just trying to figure out the cheapest way to get bolts for conflat at this point if anyone else has any notes on this. 06-Jan-20 10:21 AM and the "buying your local surplus store out of all their pre-packaged stainless and non-stainless hardware" is pretty much already done lol 06-Jan-20 10:21 AM oh norcal may even be cheaper though I don't think they have the nice dual nut plates 06-Jan-20 10:21 AM https://www.n-c.com/Products/Flanges-Fittings-and-Adapters/Conflat-Components-and-Hardware/Hardware-and-Accessories/Bolts-and-Bolt-Kits.aspx 06-Jan-20 10:21 AM or oh they do, on another page 06-Jan-20 10:21 AM oof those prices though 06-Jan-20 10:21 AM yea Duniway seems the cheapest for the platenut kits though they are vague about contents of the kit... 06-Jan-20 10:21 AM they say qty 25... for all of their kits which is weird 06-Jan-20 10:21 AM for example 8" conflat only needs 20 bolts 10 nutplates and well wither 10 or 20 washers, I've seen either way, and yea... 06-Jan-20 10:21 AM they just say qty 25... 06-Jan-20 10:21 AM which means just about nothing 06-Jan-20 10:21 AM https://www.duniway.com/catalog/hardware/bolts-studs-nuts 06-Jan-20 10:45 AM Probably assume people will just need more or less and it's cheaper for them to only deal with one bagging operation 06-Jan-20 10:46 AM maybe... 06-Jan-20 10:46 AM I mean conflat is standardized to the point that its a set number of holes... 06-Jan-20 10:46 AM so if your selling a specific 6" or 8" or 10" kit you know which bolts and how many you need 06-Jan-20 10:46 AM and its generally ALWAYS an even number 06-Jan-20 10:46 AM so yea just weird 06-Jan-20 01:54 PM @piGuy what machine? 06-Jan-20 01:55 PM https://www.ebay.com/itm/LNS-Technologies-Benchtop-Plastic-Injection-Molding-Machine-Model-150A/133276180214?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649 06-Jan-20 01:55 PM It's just a little manual desktop machine, but I want to learn the process and make prototype parts. I'm planning to use it with High Temp resin on my Form 3 SLA 3D printer 06-Jan-20 01:55 PM nice! 06-Jan-20 01:55 PM looks fun 06-Jan-20 02:22 PM I miss Lukas. Haven't read comments from him 06-Jan-20 02:22 PM @GigaSquirrel are you alive and well? 06-Jan-20 02:22 PM I hope you didnt explode 06-Jan-20 02:44 PM @Mason_Yu I haven't worked on a 1610. If you get it you probably want to make sure it has schematics 06-Jan-20 02:44 PM No manuals or schematics are available I'm told 06-Jan-20 02:44 PM I don't have the space or the funds to get that now, and it looks like a few more options have just appeared 06-Jan-20 02:44 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200106_133209-BC718.jpg 06-Jan-20 02:44 PM I was told they are willing to let this one go for free 06-Jan-20 02:44 PM I know it's super expensive to repair a cold FEG source, but the rest of the system is tempting 06-Jan-20 02:49 PM I mean if you don't want it I'm always interested... 06-Jan-20 02:49 PM Well nothing is confirmed yet 06-Jan-20 02:49 PM I'm personally more interested in the JOEL JSM-840, it's a workhorse 06-Jan-20 02:50 PM Yeah 840s are awesome 06-Jan-20 02:50 PM Wayyyyy less of a pita than cold feg 06-Jan-20 02:52 PM I've been told it will take $30k to get a new cold FEG and have the SEM professionally serviced 06-Jan-20 02:53 PM Yeah I'm not super surprised 06-Jan-20 02:53 PM Cold feg is just really hard to work on in the field 06-Jan-20 02:53 PM If you need any info on the 840 lmk 06-Jan-20 02:53 PM I have a lot... 06-Jan-20 02:56 PM Oh yeah that'd be awesome, original manuals and schematics? 06-Jan-20 02:56 PM Yup 06-Jan-20 02:56 PM Don't have my scematics scanned yet 06-Jan-20 02:57 PM Not a problem right now, I'm not getting it lol, not yet anyway 06-Jan-20 09:20 PM Joined the server. 06-Jan-20 10:46 PM @chucrut I'm alive and well, in fact I just posted yesterday in #radiation and #swap-meet 07-Jan-20 09:21 AM Heck the parts for scrap might be worth it! 07-Jan-20 10:44 AM Hummm...selling @GigaSquirrel for parts...interesting! 07-Jan-20 11:05 AM good luck finding something that doesn't have to be burried in lead 07-Jan-20 11:08 AM I can find you a cozy SL-1 pillow. 07-Jan-20 12:45 PM I found a problem solving technique. Is called INLF (Is never Lukas fault). If your vacuum chamber doesnt get down 1 Pascal, you can repeat INLF. It works for me 07-Jan-20 12:46 PM why are you so weirdly obsessed with me 07-Jan-20 12:49 PM your a squirrel, everyone likes squirrels, especially those who play with the clicky boxes and the hot potatos 07-Jan-20 02:19 PM @Charles The JSM-6335 was just pumped down today, and it has good vacuum, low 10^-9 Torr at the gun. At least I know the diffusion pumps and ion pumps are working, and the control electronics are too 07-Jan-20 02:20 PM Fun 07-Jan-20 02:20 PM But it's just too massive for any hobbyist 07-Jan-20 02:21 PM Unfortunate. Where is it physically located? 07-Jan-20 02:21 PM On my university's campus, inside a building with loading docks 07-Jan-20 02:39 PM It's also a JEOL cold feg which is basically the hardest of hard scopes to deal with 07-Jan-20 02:39 PM Also that's -9 Pascal for green light on gun, it's -11 torr 07-Jan-20 02:41 PM We didn't go all the way, the gun has been at atmosphere for a while 07-Jan-20 02:41 PM Would take a bit more time to get down below 10^-10 Torr 07-Jan-20 02:43 PM Ah I see 07-Jan-20 02:43 PM Tip is going to be really upset about that then 07-Jan-20 02:43 PM It's already blown lol 07-Jan-20 02:43 PM Can't be more upset than that 07-Jan-20 02:44 PM You're not wrong 07-Jan-20 02:44 PM But wait it was at atmosphere for how long? 07-Jan-20 02:44 PM I don't know 07-Jan-20 02:45 PM That can kill that type of scope 07-Jan-20 02:45 PM Even if it gets back to vacuum it can still be a pretty big problem 07-Jan-20 02:46 PM I think the general understanding is that it needs a major rework 07-Jan-20 02:46 PM Or else I assume they would just keep it pumped down 07-Jan-20 02:47 PM Did it get baked with the cable in place? 07-Jan-20 02:47 PM The high voltage cable? 07-Jan-20 03:25 PM I don't think so? 07-Jan-20 03:25 PM Ok that's good 07-Jan-20 03:25 PM That is definitely need not supposed to be baked 07-Jan-20 03:28 PM Yeah I'm also not sure why the FEG was blown in the first place, it happened quite a long time ago 07-Jan-20 03:29 PM If the gun is not properly conditioned it's easy to do 07-Jan-20 03:29 PM The beam shower protocol is very important 07-Jan-20 03:29 PM Their solution was to just get a FEI VERSA 3D dual beam system in the room next door lol, and now no one cares about this FESEM 07-Jan-20 03:30 PM Lol rip 07-Jan-20 04:04 PM @Mason_Yu get it then retrofit an easier gun? At least you don't need to come up with a scanning raster system 07-Jan-20 04:06 PM Well first of all it's not on sale to the public yet, they're trying to convince some other department to pay for the service cost and find a place for it. If they get desperate to use the room, I was told they may scrap it which is where I can step in 07-Jan-20 04:06 PM Also as Adam said it is just a huge hassel 07-Jan-20 04:07 PM Well huge if you plan on using the cold feg, huge physically too, but if you want a project seems like retrofitting a easier gun would be a fun project, if not long term 07-Jan-20 04:07 PM I too was asking Adam about a cold feg a few months ago 07-Jan-20 04:07 PM It ended up selling for like $700 or $900 07-Jan-20 04:07 PM Was still under service contract 07-Jan-20 04:07 PM I only would have had to bring it home like 3,000 miles 07-Jan-20 04:09 PM Yeah it could be fun to retrofit the gun, but the column and chamber alone will be a lot heavier than the Hitachi S450 I have at the moment and I don't see any unique value in the cold FEG for me, just impractical 07-Jan-20 04:11 PM Ah if you already have an SEM then yeah it's a hard idea to think about pursuing 07-Jan-20 04:11 PM I too already have an SEM, and probably easier to fix since it's a really simple thermionic, but still haven't finished that project 07-Jan-20 04:12 PM Well me too 07-Jan-20 05:48 PM Yeah retrofitting a Thermionic on it is a lot of work as well 07-Jan-20 05:48 PM You would have to basically replace the top 2/3rds of the column 07-Jan-20 05:48 PM Because the alignment system is completely different between cold feg and Thermionic 07-Jan-20 05:50 PM Isn't it just lens voltages?? 07-Jan-20 05:50 PM I mean, figuring out a new power supply and swapping seems challenging, but it doesnt seem like physically challenging, i.e. no new fab of metal parts 07-Jan-20 05:52 PM No it's really not 07-Jan-20 05:52 PM The lenses themselves are very different 07-Jan-20 05:52 PM It would be a lot of new metal parts 07-Jan-20 05:52 PM Cold feg is very very strange 07-Jan-20 05:52 PM The lenses are different on the top half of cold feg as well 07-Jan-20 05:52 PM That's why I said top 2/3rds would need to be replaced 07-Jan-20 05:59 PM I think we need diagrams 07-Jan-20 05:59 PM It's totally unintuitive to think why adding a broadband source would change so much 07-Jan-20 05:59 PM It really seems, ignorantly of me, that if anything it would just give crappier resolution 07-Jan-20 06:01 PM Not really 07-Jan-20 06:01 PM Cold feg extraction is very very different than Thermionic 07-Jan-20 06:01 PM Jeol cold feg doesn't even have tilt shift alignment coils 07-Jan-20 06:01 PM So you couldn't even begin to properly align a Thermionic gun 07-Jan-20 06:01 PM Your would have to replace all of the filament housing, extractor, and anode hardware just to get a thermionic beam down the column 07-Jan-20 06:01 PM And after that the drift distance is still way to long so you're going to lose most of your beam before you even hit the first condensor lens 07-Jan-20 06:14 PM Now then once you get a thermionic beam down the column and below the 1st condensor lens yeah it would work just at a greatly reduced resolution 08-Jan-20 12:05 PM any suggestions on a digital vacuum gauge? i've seen one in a couple videos but it has poor reviews on amazon 08-Jan-20 12:06 PM you probably need to specify a range of vacuum that you are talking about to get any useful input 08-Jan-20 12:07 PM @samy you already have the 901p! 08-Jan-20 12:09 PM @Deleted User true but i don't like having to walk over to my computer every time i want to look, i'd like to build a digital reader for it but trying to prioritize tasks and time available here 08-Jan-20 12:10 PM Pretty sure someone wrote an arduino program to talk to it via rs232 08-Jan-20 12:10 PM Can easily throw something together with an LCD or OLED if you have one on hand 08-Jan-20 12:11 PM there is so much fun stuff to work on and that has started as a project in itself (DRO for 901P) but will take valuable time i could be trying to get a better sputtering setup going right now! 08-Jan-20 12:12 PM digital vacuum gauges you can buy cheaply are generally not good 08-Jan-20 12:12 PM why not just hook up the 901p to a free harbor freight multimeter? 08-Jan-20 12:12 PM yeah, just takes more time than i'd hoped. got 232 working with an analog circuit but was providing +/-12V which would be a pain for a portable unit, just got the MAX3232 last night and tried getting that going but was having issues on the 232 side 08-Jan-20 12:12 PM or did the analog out really die 08-Jan-20 12:13 PM found one 08-Jan-20 12:13 PM #include #include #include #define OLED_RESET 4 Adafruit_SSD1306 display(OLED_RESET); String sensorValue; void setup() { Wire.begin(); display.begin(SSD1306_SWITCHCAPVCC, 0x3C); // initialize with the I2C addr 0x3C (for the 128x32)(initializing the display) Serial.begin(9600); } void displayPressure() { Serial.print ("@254PR3?;FF"); sensorValue = Serial.readString(); sensorValue.remove(0, 7); //Remove the forst 7 caracters from @253ACK7.39E+2;FF to get 7.39E+2;FF sensorValue.remove(7); //Remove caracters from the 7th, to get 7.39E+2 display.clearDisplay(); display.setTextColor(WHITE); display.setTextSize(1); display.setCursor(0, 0); display.print("Foreline Pressure"); display.setTextSize(2); display.setCursor(0, 12); display.print(sensorValue); display.setTextSize(1); display.setCursor(98, 25); display.print("Torr"); } void loop() { displayPressure(); display.display(); } 08-Jan-20 12:13 PM more here 08-Jan-20 12:13 PM https://fusor.net/board/viewtopic.php?f=10&t=11533&start=40 08-Jan-20 12:14 PM @LRM the output is differential 08-Jan-20 12:14 PM oh i guess that's fine with a meter if one side is "ground" 08-Jan-20 12:14 PM ahh thanks @Deleted User 08-Jan-20 12:14 PM throw that into an arduino and adapt to a display you have 08-Jan-20 12:14 PM should only take a few minutes to set up 08-Jan-20 12:18 PM @samy which output is differential? the analog out (connect up to pins 5/6) should track pretty well with the chart in the 901p manual... https://i.gyazo.com/339357c784dab4c56282ce4fd9650a40.png 08-Jan-20 12:18 PM then you can at least use it and just convert the voltage on the meter to the chart 08-Jan-20 12:18 PM I'm pretty sure the only thing the 901p manual says is not to connect power and output together? 08-Jan-20 12:19 PM yeah thats why i was suggesting one of the meters harbor freight literally gives away 08-Jan-20 12:19 PM doesnt need to be anything super...just simple 08-Jan-20 12:19 PM but the digital output is nicer anyway 08-Jan-20 12:21 PM totally agree, just wanted to give him an option that works right away 08-Jan-20 12:28 PM @LRM that's a good idea, i'll try that 08-Jan-20 01:28 PM @samy ITO is a very fussy material to work with 08-Jan-20 01:28 PM temperatures kill it, contamination kills it, thickness kills it 08-Jan-20 01:28 PM https://www.youtube.com/watch?v=9OEz_e9C4KM 08-Jan-20 01:29 PM ahh interesting 08-Jan-20 01:30 PM With your equipment you should be able to do it 08-Jan-20 01:30 PM But you will need a turbopump and a proper chamber 08-Jan-20 01:34 PM ok cool 08-Jan-20 01:34 PM glass jar and aluminum block seems to be good enough to be a proper chamber? 08-Jan-20 01:35 PM yep 08-Jan-20 01:35 PM a proper vacuum bell jar is awesome for high vacuum 08-Jan-20 01:36 PM Hard to find a jar that size though 08-Jan-20 01:36 PM a smaller one is easier to find 08-Jan-20 01:48 PM i know a guy who has an extra 18"(?) diameter one... 08-Jan-20 01:48 PM but that is way too big heh 08-Jan-20 01:53 PM i have a bell jar plate for a 12" one but all the new ones are $$$$ 08-Jan-20 01:53 PM otoh, no reason i can't use it with smaller ones 08-Jan-20 01:53 PM 3x KF40 + 4x KF25 is rly nice though.. though the three multipin power/thermocouple feedthroughs it came with are arguably a lot nicer on their own 08-Jan-20 01:57 PM I passed up on a 12" bell jar in a dump earlier last year... 08-Jan-20 01:57 PM noooo 08-Jan-20 01:58 PM Was pretty heavy and I had no use for it at the time 08-Jan-20 01:58 PM tbh i'd be slightly wary about a dump-plucked bell jar anyways 08-Jan-20 01:58 PM It might be a 10" one though, really dirty on the inside 08-Jan-20 01:58 PM the glass implosion risk still wigs me out a bit 08-Jan-20 01:59 PM Yeah, the edge didn't look prestine neither, will be tough to get a perfect seal 08-Jan-20 01:59 PM oh if it had any visible damage i absolutely would not use it, yeah 08-Jan-20 01:59 PM that thing's gotta hold off many thousands of pounds of atmospheric pressure 08-Jan-20 01:59 PM expertly pulls numbers out of their butt 08-Jan-20 02:03 PM Yeah that's about right. That bell jar might have microscopic scratches that I can't see due to how dirty it is 08-Jan-20 02:03 PM Same problem with jars on eBay with unclear pictures 08-Jan-20 02:06 PM to that end, i've got some big linear polarizer sheets en route to throw together a big 'ol diy polarimeter.. curious if i can see induced stresses in e.g. a mason jar while putting it under vacuum 08-Jan-20 02:06 PM would be really cool if it turns out to be a cheap way of preempting an implosion 08-Jan-20 02:06 PM (probably also a good high-speed camera candidate, if it does implode :D) 08-Jan-20 02:09 PM https://www.youtube.com/watch?v=c4VdSuU8TC0 08-Jan-20 02:09 PM It is quite surprising how much force a glass jar can hold even when scratched though 08-Jan-20 02:09 PM And there's your high speed video 08-Jan-20 05:59 PM it's hard to tell thickness but are these types of bell jars likely suitable for getting down to -8 or -9? https://www.amazon.com/Glass-Cloche-Bell-Display-Bamboo/dp/B012SXDACG 08-Jan-20 05:59 PM i doubt that would be safe at all 08-Jan-20 06:00 PM too thin? 08-Jan-20 06:02 PM yeah those display ones for clocks and stuff are very thin 08-Jan-20 06:02 PM also have very uneven finishes on some that ive seen 08-Jan-20 06:02 PM where some places are thinner or thicker than others 08-Jan-20 06:02 PM ahh 08-Jan-20 06:02 PM or bubbles 08-Jan-20 06:35 PM and for ITO sputtering is it terribly important what foreline trap i get? looking at https://www.ebay.com/itm/MDC-KMST-150-2-Vacuum-1-5-Tube-4-5-Body-NW40-Molecular-Foreline-Sieve-Trap/254415707484?epid=1523951966&hash=item3b3c5b9d5c:g:U6sAAOSwaShdxnJu 08-Jan-20 06:35 PM i would need to make NW->KF but can't imagine that will be too bad 08-Jan-20 06:35 PM oh interesting seems like they're compatible, but just diff sizes 08-Jan-20 06:36 PM Huh? NW is KF 08-Jan-20 06:36 PM ok cool 08-Jan-20 06:36 PM Yeah you can buy really cheap adaptors on either eBay or LDS 08-Jan-20 06:36 PM And it doesn't matter much what particular foreline trap you get 08-Jan-20 06:36 PM Just make sure it's filled with fresh zeolite and you'll be good to go 08-Jan-20 06:36 PM Or bake out a used one 08-Jan-20 06:46 PM just make sure whatever zeolite you put in has been freshly baked out too 08-Jan-20 06:46 PM unless you just got it from a freshly opened bag or something and know 100% it was vacuum sealed and dry inside 08-Jan-20 06:46 PM like if you buy a bag off ebay that was re-packaged by someone or something you can't really guarantee how much moisture is in it already 08-Jan-20 06:49 PM ahh 08-Jan-20 06:49 PM https://www.ebay.com/itm/Inline-Heated-120V-sorption-Traps-2-Available-Used-Working-Condition/333464853207 08-Jan-20 06:49 PM Baking already integrated! 08-Jan-20 06:49 PM Don't know how much the shipping is for you but it's like $50 for me for some reason 08-Jan-20 06:50 PM yeah $44 08-Jan-20 06:50 PM Oh that's nice to see them with baking integrated 08-Jan-20 06:50 PM though I would assume you could modify normal ones by wrapping them in some heaters 08-Jan-20 06:50 PM so guessing better to get that over something like https://www.ebay.com/itm/MDC-KMST-150-2-Vacuum-1-5-Tube-4-5-Body-NW40-Molecular-Foreline-Sieve-Trap/254415707484?epid=1523951966&hash=item3b3c5b9d5c:g:U6sAAOSwaShdxnJu where i'd have to bake myself 08-Jan-20 06:51 PM You can buy mains heating bands quite cheap anyway 08-Jan-20 06:51 PM And if you plan on doing high vacuum work in the future you'd need them eventually 08-Jan-20 06:51 PM that one has a hole for a heater cartridge too 08-Jan-20 06:51 PM so if you can get the right heater cartridge for that you'd be in business though I don't know how you'd find those besides going to the manufaturer 08-Jan-20 06:52 PM Also that's a KF16 flange, so you likely still need an adaptor 08-Jan-20 06:52 PM honestly I should probably get one with a heater myself, I just got one of those itty kf25 ones 08-Jan-20 07:04 PM So I've got a length of tubing from the SEM into the foreline pump via a KF adaptor. I don't have a foreline trap at the moment and it wasn't a problem with the diffusion pump, but I would like to swap to a full turbo set up without the cooled baffle, so I'd need to either take off a foreline trap from another set-up or buy a new one 08-Jan-20 07:04 PM Can I just fiil the tube with zeolite though? 08-Jan-20 07:04 PM With one of those kf clamps with sieve in the middle 08-Jan-20 07:05 PM probably not a good idea to fill the a hard-to-remove tube with zeolite 08-Jan-20 07:05 PM It's not too hard to remove 08-Jan-20 07:05 PM When I need to remove the zeolite I would disconnect the kf to hose adaptor and pour it out of the tube 08-Jan-20 07:06 PM you'll need to clean the tube 08-Jan-20 07:07 PM Yeah, just like all the rest of components in vacuum that's currently covered in diffusion pump oil and foreline pump oil 08-Jan-20 07:07 PM I guess I'll give it a go before buying a new trap 08-Jan-20 07:08 PM I just spent like an hour re-designing this NEMA17 footprint 08-Jan-20 07:08 PM https://i.spirit.re/A1XlI.png 08-Jan-20 07:08 PM this time it's perfect 08-Jan-20 07:08 PM and a hair smaller than actual NEMA17 so you can put an enclosure around the sides 08-Jan-20 07:09 PM So this can drive both steppers and regular motors? 08-Jan-20 07:09 PM Or is this a completely different board? 08-Jan-20 07:09 PM 3-phase AC servos 08-Jan-20 07:09 PM and DC if you really want 08-Jan-20 07:10 PM Oh I see, a repackaging of your current design then 08-Jan-20 07:10 PM a total redesign actually 08-Jan-20 07:10 PM the single-chip solution simply didn't work 08-Jan-20 07:10 PM something is causing the driver to lock up and not respond 08-Jan-20 07:11 PM Which chip did you use? 08-Jan-20 07:11 PM (and it's not power as I shoved an isolated linear power supply on the analog/low power section) 08-Jan-20 07:11 PM I used the STSPIN32F0A 08-Jan-20 07:11 PM Does it have feedback onboard? 08-Jan-20 07:11 PM of course 08-Jan-20 07:11 PM I just haven't populated this board yet 08-Jan-20 07:11 PM it will have a 14-bit absolute magnetic encoder 08-Jan-20 07:11 PM an upgrade from the previous 12 08-Jan-20 07:11 PM also much colder, more efficient FETs(<10mOhm and <10nC @ 12V @ 10A versus >25mOhm/nC for the previous), a slightly higher input voltage range of around 8-50V(totally unintentional, I was going for lower), and a lot more processing power 08-Jan-20 07:11 PM upgrading from a tiny 48MHz STM32F031K with no FPU/division inside the STSPIN to an STM32G431C, which will run at 160MHz, has an FPU, and even a dedicated math accelerator with ~500% increase in speed for the functions I will use 08-Jan-20 07:11 PM and surprisingly it's not going to be a very huge price increase, if at all 08-Jan-20 07:11 PM oh, and it's going to have 3-phase low-side current sensing, so true FOC is now going to be possible. 08-Jan-20 07:25 PM Are you planning on making some larger versions if this design works out? 08-Jan-20 07:25 PM I guess bigger FETs alone won't cost that much more right? I'd be super interested in this for larger NEMA formats 08-Jan-20 07:26 PM yep, this version is easily scalable from single-digit watts to kilowatts 08-Jan-20 10:45 PM https://www.gia.edu/images/152932_634x358.JPG 08-Jan-20 10:45 PM interesting that they could get away with using a big diffusion pump (that is what that is...right?) for crystal growing 08-Jan-20 10:45 PM https://www.gia.edu/gia-news-research-Sapphire-Series-Next-Generation-Growth-Techniques 08-Jan-20 10:45 PM that is a Kyropoulos setup from GT 08-Jan-20 10:57 PM possibly chilled? 08-Jan-20 10:58 PM i would assume so, if you squint you can kinda see there might be a LN2 trap above it 08-Jan-20 11:45 PM Right, well, my goals were a little too ambitious 08-Jan-20 11:45 PM https://i.spirit.re/IQZAB.png 08-Jan-20 11:45 PM This is impossible to route 08-Jan-20 11:45 PM (assuming some kind of decent design rules) 09-Jan-20 12:13 AM oh wow wth just happened 09-Jan-20 12:13 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-6CB64.png 09-Jan-20 12:13 AM nice 09-Jan-20 12:15 AM nice thats even cheaper than mine was heh 09-Jan-20 12:15 AM glad i did not have to pay shipping tho 09-Jan-20 12:15 AM how much did that end up being for you? 09-Jan-20 12:21 AM ~700 usd 09-Jan-20 12:22 AM I'm holding out for a self-contained pulse-tube/stirling unit 09-Jan-20 12:23 AM I need LN2, so I need powe 09-Jan-20 12:23 AM I don't just want to make things cold, I need to keep a thing cold that eats a liter of ln2 a day 09-Jan-20 12:23 AM same, plan is to rig up a liquefaction system 09-Jan-20 12:24 AM but those tiny stirlings are like half a liter per day tops 09-Jan-20 12:26 AM iunno, the old-school superconductor technology LNA cooler system, hybrid 98 I think it is, is fairly beefy 09-Jan-20 12:26 AM in any case, I don't need quite your output I don't think.. space is more of a concern than output at the moment 09-Jan-20 12:34 AM im assuming you ran the math for getting LN2 vs the cryo 09-Jan-20 12:34 AM is it pretty expensive over there? the killer here is that basically everywhere forces you to rent a dewar from them AND pay a delivery fee because of some California laws nobody can seem to point me to 09-Jan-20 12:34 AM i still have not gotten around to pricing the UHP helium fill and whatever is necessary to try and get mine running but i do not have a pressing need like you do 09-Jan-20 12:38 AM it's not that it's expensive, but that no one sells below 1000 liters 09-Jan-20 12:38 AM and I just can't store that much 09-Jan-20 12:38 AM the He doesn't have to be UHP, 4.6 is more than enough 09-Jan-20 12:38 AM and mine still has some pressure inside 09-Jan-20 12:38 AM ~14 bar 09-Jan-20 12:41 AM oh thats weird, here you can buy it in incremental amounts 09-Jan-20 12:41 AM well, germany is weird 09-Jan-20 12:43 AM who is the average 1000 L of LN2 customer do you know? haha 09-Jan-20 12:44 AM most companies here have a giant (5-10 m³) ln2 tank outside, and an evaporator 09-Jan-20 12:44 AM selling to individuals is something many sellers don't want to do, so they set a lower limit that makes it basically impossible 09-Jan-20 12:46 AM prices from the closest place to me are from $5.08 to $2.83 per L in 5, 10, 15, 17, 20, 25, 30, 35, 45, 50 dewar sizes (with price decreasing as you buy more). 09-Jan-20 12:46 AM but then there is a $20 delivery fee and they wont deliver (as far as I know) unless you rent/buy a dewar from them 09-Jan-20 12:47 AM lol, the dewar thing is weird 09-Jan-20 12:47 AM good thing I already have ~50l of dewars here 09-Jan-20 12:47 AM yeah it felt like some corporate policy to squeeze more money out of people 09-Jan-20 12:47 AM their thing was that if you rent it they are responsible for maintenance...but it is a dewar not a lot of things to be maintaining 09-Jan-20 12:47 AM also would love to hear about your planned dry nitrogen gas supply for this too. i was giving it a little bit of thought just as a side project but you are probably much further along 09-Jan-20 12:51 AM they need to be pumped every couple of years 09-Jan-20 12:51 AM yeah I don't have any plans so far 09-Jan-20 12:51 AM for starters I'll just use tonnes of CaCl2 and air 09-Jan-20 12:51 AM maybe some day a nitrogen membrane will find its way to me 09-Jan-20 01:06 AM are there any lab nitrogen generators on ebay local to you? ...there is one for parts in my area but i do not really want to throw a $100-$200 offer at something listed for $1400 as "Condition: For parts or not working" and actually have the seller accept 09-Jan-20 02:32 AM @GigaSquirrel woot!!! 09-Jan-20 02:32 AM See this is why you get for threatening to send money to the US, Europe only demands your business in return haha 09-Jan-20 02:33 AM it comes from the usa tho 09-Jan-20 02:33 AM oh really? 09-Jan-20 02:33 AM wait so you found a US seller that will ship that thing to Germany?!?! 09-Jan-20 02:33 AM for less than a grand?!?! 09-Jan-20 02:34 AM no Idea if he is actually willing to do so 09-Jan-20 02:34 AM but ebay said it's 350 in shipping 09-Jan-20 02:34 AM and I already paid that 09-Jan-20 02:34 AM sooo 09-Jan-20 02:34 AM XD 09-Jan-20 02:34 AM omg 09-Jan-20 02:34 AM poor guy 09-Jan-20 02:34 AM I bet if he does end up shipping he immediately bans all outside of north america from seeing his posts 09-Jan-20 02:34 AM oh for sure 09-Jan-20 02:34 AM but I don't care XD 09-Jan-20 02:35 AM but who knows 09-Jan-20 02:35 AM if he works for some company with a shipping department 09-Jan-20 02:35 AM he may get some stupid rates 09-Jan-20 02:35 AM tbh I'm not entirely confident he will even ship it 09-Jan-20 02:35 AM but who knows 09-Jan-20 02:35 AM good luck :) 09-Jan-20 02:36 AM thanks ^.^ 09-Jan-20 03:20 AM @samy I setup a display to read out the mks901p using a raspberry pi, it was just a library download away. Plenty of cheap character LCD displays that already have arduino shield form factor, or SPI protocols... All should be like 5 mins of coding to get text displayed on once wires are connected 09-Jan-20 03:20 AM I definitely would heed the warning of the MKS docs and only try extracting the pressure reading if the ACK was present (vs NAK for failures) 09-Jan-20 03:20 AM @samy this is what I had sitting on a shelf from an AliExpress buy years ago https://www.amazon.com/HiLetgo-LCD1602-Output-expansion-Arduino/dp/B00OGYXN8C/ 09-Jan-20 03:20 AM I paid about half as much or less from AliExpress... But hey, it's prime shipping 09-Jan-20 03:20 AM The buttons work well too, using this library which debounces presses https://github.com/dzindra/LCDKeypad/blob/master/README.md 09-Jan-20 10:18 AM moin! 09-Jan-20 11:01 AM Pis are an incredible overkill for reading out a gauge 09-Jan-20 11:01 AM But it works 09-Jan-20 12:04 PM Yeah, it's a first gen... I had it on a shelf doing nothing anyway, and the USB port meant I could get away with a USB to rs232 adapter when the TTL to Rs232 turned out to be fake 09-Jan-20 12:04 PM I had it out and working in an attempt to use the camera module for an optical microscope need, but ended up using a different scope which already had a CCD and LCD panel of it's own 09-Jan-20 12:04 PM Was just thinking last night that I might try using an esp32-cam module as a way to auto tune plasma capacitor and inductor settings based on image feedback 09-Jan-20 12:04 PM Saw similat approach in a paper recently 09-Jan-20 01:21 PM thanks nmz 09-Jan-20 01:31 PM @nmz787 ooh, i'd be interested in that paper if you can find it again 09-Jan-20 03:43 PM Me too 09-Jan-20 08:59 PM so i'm trying to find a bell jar i can use for sputtering and dang this stuff is expensive. could i just get this, get rid of the top, and heat up the top opening on the lathe and close it? https://www.ebay.com/itm/VACUUM-BELL-JAR/274174363058?hash=item3fd610c5b2:g:PVgAAOSwHt9eCjY9 09-Jan-20 08:59 PM or some other way to close that top to allow a high vacuum? 09-Jan-20 09:02 PM yea bell jars are expensive, generally if you find them cheap its more like pickup or pay 200 in shipping and pray it won't get destroyed 09-Jan-20 09:06 PM Any machining, chipping, scratching, cutting, or spot heating of the glass likely means it's already scrap 09-Jan-20 09:07 PM ok 09-Jan-20 09:09 PM you shouldn't need to take the top off though 09-Jan-20 09:09 PM build your entire sputtering rig on the base plate, with all the feedthroughs, then just plop the jar on top of it 09-Jan-20 09:09 PM like Ben did 09-Jan-20 09:20 PM I think he’s asking because it’s a removable glass stopper at the top 09-Jan-20 09:20 PM https://www.bmisurplus.com/products/33993-lurex-flanged-bell-jar-with-top-knob-and-ground-flange 09-Jan-20 09:20 PM 3x as much, but it is closed at the top and similar size it looks 09-Jan-20 09:25 PM @samy i would not try melting/sealing glass like that unless you know exactly what kind of glass it is and have hours to slowly cool it down 09-Jan-20 09:25 PM better to buy something that will just work for this sort of thing if you are going for a bell jar 09-Jan-20 09:27 PM http://www.seohcorp.com/seoh-bell-jar-glass-with-knob-top-6-inch-x-10-inch/ 09-Jan-20 09:27 PM Smaller size if you want kinda similar pricing to initial 09-Jan-20 09:34 PM https://www.ebay.com/itm/High-Vacuum-Coating-Bell-Jar-Corning-Pyrex-Glass-Heavy-Wall-18-x-30/113859461806 ...could try offering this guy a couple hundred bucks and get a complete overkill one 09-Jan-20 09:34 PM same seller has a basically full coating system too it seems 09-Jan-20 10:01 PM its sometimes cheaper just getting a whole setup if you can find something local 09-Jan-20 10:01 PM paying a grand for an entire broken coating system with an intact bell jar is nicer than paying a grand for a piece of glass 09-Jan-20 10:06 PM the system that seller has is listed for like $5000 https://www.ebay.com/itm/High-Vacuum-Coating-Sputtering-Bell-Jar-Coater-2020A-Pump-Alcatel-Turbo-CRR-450/382902296131 09-Jan-20 10:06 PM not a good deal at all unless they were going to take a crazy low offer 09-Jan-20 10:18 PM yea its not worth it for that much 09-Jan-20 10:18 PM I have seen similar systems for around a grand 09-Jan-20 10:22 PM Can I use thermal evaporation to coat acrylic sheet with aluminum? Or will the acrylic get melty? 09-Jan-20 10:23 PM Depends on how much you want to coat and with what 09-Jan-20 10:25 PM For example, maybe like a 50x50x3mm piece of acrylic, depositing enough aluminum to function as an optical mirror 09-Jan-20 10:26 PM x3 might be hard 09-Jan-20 10:26 PM Do you want acrylic, or will glass work too? 09-Jan-20 10:26 PM how large of a chamber are you working with? 09-Jan-20 10:29 PM Chamber doesn't exist yet 09-Jan-20 10:29 PM thanks all...lol @ the seohcorp description 09-Jan-20 10:29 PM ends with "It can withstand small amounts of Vacuum. How much Vacuum" 09-Jan-20 10:29 PM end of description...yes, how much vacuum! 09-Jan-20 10:30 PM "some" 09-Jan-20 10:31 PM @mike crb those look good 09-Jan-20 10:31 PM it would take some planning but you could probably do a setup like people do for telescope mirrors where they vaporize some 99.999% aluminum wire off of tungsten wire heating elements 09-Jan-20 10:31 PM just have to have enough distance to keep the acrylic cool 09-Jan-20 10:33 PM @LRM how so, the tungsten is connected serially to aluminum wire? 09-Jan-20 10:33 PM no even more basic you just set the aluminum on the tungsten wire 09-Jan-20 10:34 PM that wouldn't just evaporate the tungsten onto the aluminum? 09-Jan-20 10:34 PM or it would do that + vaporize the aluminum? 09-Jan-20 10:35 PM i do not think that the tungsten vaporizes much...the aluminum all would evaporate off way before the tungsten got hot enough 09-Jan-20 10:35 PM tungsten melts like...1000C over aluminum 09-Jan-20 10:37 PM https://www.youtube.com/watch?v=Ct3jtrMrrnQ 09-Jan-20 10:38 PM fancy 09-Jan-20 10:38 PM was just going to grab that, thanks mason 09-Jan-20 10:38 PM actual coating happens around 11mins 09-Jan-20 10:38 PM oh its 99.998% my bad haha 09-Jan-20 10:38 PM wonder if that 0.001% makes much difference 09-Jan-20 10:48 PM That's a big boy vacuum chamber 09-Jan-20 10:58 PM Does someone have a web-page on different heating wires for making tube furnaces or so? I am going to build one and I remember when I was talking in the past someone linked me a page talking about different wires and what temps they get up to... I can't find it though with searching. 09-Jan-20 10:58 PM @Nixie maybe you? 09-Jan-20 11:03 PM FeCrAl(Kanthal) has the highest melting point of around 1500C 09-Jan-20 11:03 PM working temp of 1400C 09-Jan-20 11:03 PM and I believe it also lives longer than nichrome? 09-Jan-20 11:03 PM 1.4uOhm-m 09-Jan-20 11:09 PM I need to get to about 1200C tops so that would probably be best just to be sure I have the range and lifespan 09-Jan-20 11:10 PM kanthal goes higher but last less time near its max temps than nichrome afaik 09-Jan-20 11:10 PM it will last far longer than nichrome at equivalent temps 09-Jan-20 11:10 PM but once you start going over the range of nichrome the kanthal has a finite lifespan 09-Jan-20 11:10 PM not a big deal to wind a new element though 09-Jan-20 11:12 PM hrm 09-Jan-20 11:12 PM what's nichrome good to? 09-Jan-20 11:12 PM less than 1200 09-Jan-20 11:16 PM Guess I'll go with Kanthal, its super cheap anyway apparently 09-Jan-20 11:17 PM thats why it is not a big deal to wind a new element 09-Jan-20 11:17 PM yea I mean this is going to be a tube furance so it'll just be a matter of opening it, pulling the quartz tube out and laying a new coil in 09-Jan-20 11:17 PM or two 09-Jan-20 11:17 PM this is a fairly large tube... 4" diameter 09-Jan-20 11:17 PM you can probably use the nichrome calculator and just change the gauge to match the ohms/ft of the kanthal 09-Jan-20 11:18 PM https://www.ebay.com/itm/3000W-Heating-Element-Coil-Heater-Wire-Line-3KW-Kanthal-A1-Furnace-Resistance/202810295187 09-Jan-20 11:18 PM to figure out the element details 09-Jan-20 11:18 PM well so its like 31" not stretched... 09-Jan-20 11:18 PM needs to be stretched to be usable 09-Jan-20 11:18 PM https://temcoindustrial.com/product-guides/wire-cable-and-accessories/resistance-and-non-resistance-wire/kanthal-wire 09-Jan-20 11:18 PM I don't need to use the entire length of the tube... just enough to get a 3" wafer or two in honestly and enough over shoot to make sure its evenly heated 09-Jan-20 11:18 PM i bought just the wire and made my own for my heat treat furnace 09-Jan-20 11:18 PM can make like 4 heating elements for mine from one $15 spool 09-Jan-20 11:20 PM oh hrm 09-Jan-20 11:20 PM the kanthal on ebay there says its only good up to 600 degrees... 09-Jan-20 11:20 PM suppose I'll have to get some and just wind my own as-well 09-Jan-20 11:21 PM weird, 1400C/1300C are the two types temco sells 09-Jan-20 11:21 PM wonder what chinesium kanthal actually is 09-Jan-20 11:21 PM lol probably not great is what 09-Jan-20 11:21 PM well, fecral should be fecral 09-Jan-20 11:23 PM oh maybe they are saying the element is meant to get about 600C on 220VAC and draws 3000W 09-Jan-20 11:23 PM not that 600C is the max temp for the kanthal 09-Jan-20 11:23 PM just looked at the auction 09-Jan-20 11:24 PM ah hrm maybe 09-Jan-20 11:34 PM Think I'll just get some wire from that company you linked LRM, just need to make sure I get the right gauge and enough of it to build a coil or two 09-Jan-20 11:34 PM I'll probably aim for 2 or 4 coils, either one top and bottom or two top and bottom depending on how the length and such works out... 09-Jan-20 11:34 PM try and aim for being usable on a 220V 30A circuit. 09-Jan-20 11:34 PM @Conmega go directli co kanthal 09-Jan-20 11:34 PM 1200C top end 09-Jan-20 11:35 PM 1200ºC is the absolute tops max for nichrome, and it's going to oxidize fast and burn 09-Jan-20 11:35 PM I remember writing something about wires in a blog post, but nothing I would reference too much. 09-Jan-20 11:37 PM but yea this bad boy did arrive safe and sound so I need to start building 09-Jan-20 11:37 PM yep and at temps over 1200C you will probably get some of the Cr coming off of the kanthal that leave your furnace a nice green tint 09-Jan-20 11:37 PM https://www.ebay.com/itm/Fused-Quartz-Tube-30-L-x-102-8-mm-ID-x-107-7-mm-OD-x-2-2-mm-wall/114004165971 09-Jan-20 11:38 PM My oven is pretty, though: 09-Jan-20 11:38 PM yea I mean I probably only really need to get to 900C or so... 09-Jan-20 11:38 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/img_20180523_211153-e1527238870124-A6FF9.png 09-Jan-20 11:38 PM but aiming for 1200C top end is what I'd like to do 09-Jan-20 11:38 PM Then just go kanthal 09-Jan-20 11:38 PM wow yea you did a good job on that 09-Jan-20 11:38 PM how did you get those through holes made? 09-Jan-20 11:38 PM like without just destroying everything lol 09-Jan-20 11:38 PM https://electronicmercenary.wordpress.com/2018/05/27/this-boring-company-i/ 09-Jan-20 11:38 PM ball router bit is how i think most people do it 09-Jan-20 11:38 PM no idea how it was done on the curve tho 09-Jan-20 11:39 PM Nah, I overcomplicated the thing to an extreme 09-Jan-20 11:39 PM did end up really nice 09-Jan-20 11:39 PM https://www.youtube.com/watch?v=nW63QDzYppk&feature=emb_logo 09-Jan-20 11:39 PM jeez haha 09-Jan-20 11:39 PM cant think of any other way to get the nice curve so good job! 09-Jan-20 11:39 PM not really over complicated at all 09-Jan-20 11:40 PM too bad your not in the state's I'd just pay you to make me one :P 09-Jan-20 11:41 PM maybe a super long ball cutter and guide you can set in a half cylinder on the bricks? 09-Jan-20 11:41 PM still...more complicated than that setup 09-Jan-20 11:43 PM yea hrm, either way I think whatever I do will end up a lot less effort and cheezier and worse built than Nixie made :P 09-Jan-20 11:44 PM https://tenor.com/view/toddlers-and-tiaras-reality-smile-creepy-evil-gif-3372814 09-Jan-20 11:44 PM I will be working with the bricks width wise though so I don't need to go as deep on each I guess 09-Jan-20 11:44 PM just consistent on all of them 09-Jan-20 11:44 PM probably just need to get a freaking drill-press finally and that will probably be enough for me 09-Jan-20 11:45 PM Depends on how do you want to attack the block, but yes, some angle wedges should be good. 09-Jan-20 11:45 PM For my next oven, I would do them also widthwise, and more control zones, so I can replace one if it breaks more easily than now that Ihave the whole lenght of the oven. 09-Jan-20 11:45 PM too bad your not in the state's I'd just pay you to make me one 09-Jan-20 11:45 PM Not everything can be solved with money...oh, wait... 09-Jan-20 11:48 PM :P 09-Jan-20 11:48 PM Shame also, because I could just sell my main oven to you 09-Jan-20 11:48 PM I have plans for a smaller version for my 1cm square final sizes. 09-Jan-20 11:48 PM so I won't be using the big oven much longer. 09-Jan-20 11:49 PM drill press and 3d printed pattern would totally work 09-Jan-20 11:49 PM depending on how creative your work holding is you might be able to manually position each hole too 10-Jan-20 12:06 AM probably just clamp some boards down to run the brick into a corner, drill holes on all bricks, change board positions, drill all next holes... etc... 10-Jan-20 12:06 AM don't need to over complicate it 10-Jan-20 12:06 AM gah I need to get a rebuild kit for one of the few corrosive rated pumps i have for when I start playing with SF6 10-Jan-20 12:06 AM and buy the expensive oil 10-Jan-20 12:24 AM make sure you use a board on the side you are clamping too...those bricks are not very sturdy 10-Jan-20 12:24 AM gahhhh I thought that was 6 or 8" on this chamber I bought... 10-Jan-20 12:24 AM 6 3/4"... 10-Jan-20 12:24 AM thanks guys 10-Jan-20 12:24 AM big end ones are 10" though 10-Jan-20 12:24 AM and there is a 4.5" 10-Jan-20 12:24 AM then a TON of 2.75" 10-Jan-20 12:24 AM one has a damaged knife edge... one... 10-Jan-20 12:24 AM the rest look good 10-Jan-20 12:24 AM and what to know what the damage is? 10-Jan-20 12:24 AM someone going in with a flat head to remove the copper ring... 10-Jan-20 12:24 AM thanks guys 10-Jan-20 12:26 AM oof 10-Jan-20 12:26 AM 13 2.75" though 10-Jan-20 12:26 AM so if I can get that ONE damaged one sealed with a blank I'll seal it and never open it again 10-Jan-20 12:26 AM Everyone should know that you have to use a torx screwdriver to get the ring out 10-Jan-20 12:27 AM i thought the specs said to use a big chefs knife, just jam it in there real good...it is a knife edge and all 10-Jan-20 12:28 AM I bought the wrong viton orings for my vacuum tube project... again 10-Jan-20 12:28 AM on a more serious note, how badly can knife edges be damaged and still seal? my nearly free turbo has a tiny ding on the knife edge so i was just planning to use viton 10-Jan-20 12:28 AM this time they do fit over the tube with a tiny stretch 10-Jan-20 12:28 AM so I'm not going to wait another month to get another set 10-Jan-20 12:28 AM I'm going to invent my own glass to metal seal! 10-Jan-20 12:29 AM it fits? send it! 10-Jan-20 12:29 AM with a viton oring the knife edge can be pretty seriously hurt 10-Jan-20 12:29 AM with copper a ding is okay too 10-Jan-20 12:29 AM just not a big one 10-Jan-20 12:30 AM i should have specified i was asking about with copper 10-Jan-20 12:30 AM that is encouraging though, this is a very small ding 10-Jan-20 12:30 AM lol this chinese packaging has a poorly copied CN23 declaration 10-Jan-20 12:30 AM "and that this item dose not contain" 10-Jan-20 12:31 AM @LRM the simple answer is... it heavily depends... 10-Jan-20 12:31 AM really all you can do is try it... 10-Jan-20 12:31 AM got a picture of the ding? 10-Jan-20 12:31 AM also 10-Jan-20 12:31 AM https://media.discordapp.net/attachments/499873492477411339/665109916004122624/DSC_2912.JPG https://media.discordapp.net/attachments/499873492477411339/665109925919326217/DSC_2913.JPG 10-Jan-20 12:31 AM you tease 10-Jan-20 12:31 AM want! 10-Jan-20 12:32 AM just checked and i do not have a picture of it handy 10-Jan-20 12:32 AM I have a 10" conflat to some larger size iso for an opening I will use 10-Jan-20 12:32 AM but that 6.75" opening is a bummer 10-Jan-20 12:32 AM jeez, this chamber is like a SEM/sputterer-builder's dream 10-Jan-20 12:32 AM lots of tiny flanges and a few big ones 10-Jan-20 12:32 AM I'll need an adapter to get one of my pumps on 10-Jan-20 12:32 AM most of my pumps are 6" or 8" 10-Jan-20 12:33 AM closing all those conflats will be fun and cheap 10-Jan-20 12:33 AM yea I think I have enough blanks and copper rings on hand honestly... 10-Jan-20 12:33 AM 2.75" is one of those things you just get tons of 10-Jan-20 12:33 AM I have very few spares of anything 10-Jan-20 12:33 AM but I'm still new to the nothing scene 10-Jan-20 12:34 AM https://media.discordapp.net/attachments/424014648757452800/665111189373583360/DSC_2914.JPG 10-Jan-20 12:34 AM this is my shelf of bits and pieces 10-Jan-20 12:34 AM of just the stuff that fits there anyway... a few other turbos and large bits of conflat that don't fit 10-Jan-20 12:34 AM and well the pallet's worth of roughing pumps 10-Jan-20 12:36 AM I still need to test my roughing pump properly 10-Jan-20 12:36 AM it's an old soviet beast with oil that is already a few years old 10-Jan-20 12:36 AM yea you'll need to let it run for awhile with the ballest open to make sure you get all the moisture out 10-Jan-20 12:36 AM for ultimate pressure but really you'll want to change the oil... 10-Jan-20 12:36 AM if the test with old oil pumps low enough... a flush and new oil will get you closer to the ultimate pressure 10-Jan-20 12:36 AM but with old oil if it tests like horridly then it probably needs a rebuild 10-Jan-20 12:38 AM I got down to around 1mbar with a silicone hose just shoved into a CF1.33" 10-Jan-20 12:38 AM so I have high hopes 10-Jan-20 12:50 AM ohhh winner winner bonus dinner 10-Jan-20 12:50 AM https://media.discordapp.net/attachments/424014648757452800/665115180820332545/DSC_2916.JPG https://media.discordapp.net/attachments/424014648757452800/665115191653957633/DSC_2917.JPG https://media.discordapp.net/attachments/424014648757452800/665115204971134976/DSC_2918.JPG 10-Jan-20 12:50 AM a little fine positioning stage on the top zero length 10" to 2.75" conflat with the weird copper pipe cooling on it. 10-Jan-20 12:51 AM mhhh cupric... mud? 10-Jan-20 12:51 AM and yea that 10-Jan-20 12:51 AM this has a warning label on the side as a class IIIb laser product 10-Jan-20 12:51 AM but I don't have any lazors :( 10-Jan-20 12:53 AM none? 10-Jan-20 12:53 AM but its nice to have a little fine positioning x-y stage vacuum rated 10-Jan-20 12:53 AM this thing has been gutted other than this 10-Jan-20 12:53 AM I dunno whats on the other side of the 2.75" blank under that green stuff 10-Jan-20 12:54 AM time to get out the gloves 10-Jan-20 12:56 AM yummyyyy 10-Jan-20 12:56 AM https://media.discordapp.net/attachments/424014648757452800/665116672553910282/DSC_2919.JPG 10-Jan-20 12:56 AM weird copper gasket 10-Jan-20 12:56 AM either way lots of this needs so much cleaning... 10-Jan-20 12:56 AM but the inside of the rest of the chamber is pretty clean 10-Jan-20 12:57 AM oh, wth is that 10-Jan-20 12:57 AM wait 10-Jan-20 12:57 AM you have an sem with edx, right? XD 10-Jan-20 12:58 AM https://media.discordapp.net/attachments/424014648757452800/665117093817221130/DSC_2920.JPG 10-Jan-20 12:58 AM yea... 10-Jan-20 12:58 AM I mean its just a custom cut copper gasket 10-Jan-20 12:58 AM with a smaller center opening 10-Jan-20 12:58 AM dunno why but yea 10-Jan-20 12:58 AM you can figure out what it is 10-Jan-20 12:58 AM if it's just copper or some other spice 10-Jan-20 12:59 AM eh I'll let you know if I'm dead in a week :) 10-Jan-20 01:00 AM please arrange some of your equipment to be shipped my way in that case 10-Jan-20 01:01 AM https://media.discordapp.net/attachments/424014648757452800/665117963657019412/20200110_040105.JPG 10-Jan-20 01:01 AM there a more convenient than conflat entrance :) 10-Jan-20 01:01 AM just need to either get a new copper ring or see if the old one wasn't wrenched down enough and might be-able to get a second use out of it 10-Jan-20 01:01 AM it wasn't touching flange to flange so 10-Jan-20 01:01 AM and its pretty clean 10-Jan-20 01:01 AM but I'll probably just get another :) 10-Jan-20 01:03 AM wow, a single cf200 ring is like 15 bucks 10-Jan-20 01:04 AM eh a pack of 10 makes them like 79 bucks from LDS 10-Jan-20 01:04 AM I know that isn't much in the vacuum world, but still 10-Jan-20 01:04 AM individually they are 10 10-Jan-20 01:04 AM so yea I'll just get a pack of 10... 10-Jan-20 01:04 AM 8 bucks a pop isn't horrible for 10" conflat 10-Jan-20 01:04 AM yep 10-Jan-20 01:05 AM but yea that little really fine adjust x-y stage that was in there is cool 10-Jan-20 01:05 AM especially since presumably its either dry or lubricated with something good for HV at-least 10-Jan-20 01:06 AM yeah you'd hope so 10-Jan-20 01:06 AM until some researcher comes along and fills the thing with motor oil or something 10-Jan-20 01:06 AM lmao yea 10-Jan-20 01:06 AM gah finding an adapter from 6.75" to anything else is either going to be a hunt or a bite the bullet and pay for one new 10-Jan-20 01:06 AM DN125... 10-Jan-20 01:06 AM whyyyy 10-Jan-20 01:09 AM I can find flanges and blanks but no adapters 10-Jan-20 01:10 AM you definitely need a welder 10-Jan-20 01:10 AM yea... 10-Jan-20 01:11 AM buy two flanges and a piece of tubing, making an adapter from that will be 10 min tops 10-Jan-20 01:11 AM I already have flanges in other sizes lmao 10-Jan-20 01:11 AM I've kinda started grabbing weldables when they are super cheap or in other lots... 10-Jan-20 01:11 AM I think I have two 6" or 8" ones brand new 10-Jan-20 02:26 AM Just use silicone like I do 10-Jan-20 02:26 AM Silicone is the best invention 10-Jan-20 02:52 AM @chucrut lol, I just got a piece of silicone sheeting in the mail today for the one side of my PVC chamber... top is a 1/2" thick pipe and a plastic salad bowl, so sort of a knife-type edge to press into the silicone... but someone mentioned things being too flat and wide is not good for sheet gaskets... so I'm a bit wary of the underside sealing well unless it was glued on with RTV or torr-seal (loctite hysol 1c) 10-Jan-20 02:52 AM @qualia here it is, it's not the best paper to be honest, more like "we ran out of money or interest, here's as far as we got" https://smartech.gatech.edu/bitstream/handle/1853/48881/71761_Applied_EPI_RF_Matching_Network_Final_Report.pdf 11-Jan-20 11:47 AM i'm thinking for a new chamber going in from the bottom so i don't have to cut any glass, and have the bottom just be an aluminum plate (and the anode). i'm thinking of using a spark plug to get the HV in but am trying to determine max voltage i can safely put in without arcing. there's a 3mm gap of air + porcelain between the electrodes of the plug so i don't know how to calculate the combination of their dielectric strengths 11-Jan-20 11:47 AM also trying to determine if i should earth ground the anode (i'm using: mains -> variac -> mot -> rectifier to produce the HVDC) 11-Jan-20 12:05 PM You can put around 1-2kV through it safely 11-Jan-20 12:05 PM More than you'd need for magnetron sputtering 11-Jan-20 12:15 PM ok, i know when i made my first attempt i believe i had to go higher in voltage before i saw anything inside the chamber, then i was able to bring it down 11-Jan-20 12:16 PM You will need to build a proper magnetron sputterer for that 11-Jan-20 12:16 PM There's no electrode on top to arc to, it's a self-contained unit 11-Jan-20 12:17 PM i think i've seen it described both ways, with electrode on top and not 11-Jan-20 12:18 PM It can work like that, but a self contained unit is a bit better 11-Jan-20 12:18 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Magnetron-scheme-EF49B.png 11-Jan-20 12:18 PM Ben has a video on building one of these and explains the construction 11-Jan-20 12:19 PM i've watched his and Thought Emproium's and they seem to go diff ways (of course Ben's was quite legit)...i was hoping to see a lot more of the plasma, hence wanting to go on top 11-Jan-20 12:20 PM You'll see plenty of plasma both ways 11-Jan-20 12:20 PM One will heat your substrate way less 11-Jan-20 12:22 PM ahh 11-Jan-20 12:52 PM @samy why not just use two spark plugs 11-Jan-20 12:55 PM @nmz787 i probably don't want the plate floating 11-Jan-20 12:55 PM in case return path finds its way to it 11-Jan-20 12:56 PM Ground it on outside? 11-Jan-20 12:56 PM I would earth the plate 11-Jan-20 12:56 PM And place the cathode at ground potential too 11-Jan-20 12:56 PM That way you can water cool it externally 11-Jan-20 12:56 PM Or just get a better spark plug 11-Jan-20 12:56 PM Need to water cool it anyway 11-Jan-20 01:11 PM k 11-Jan-20 02:58 PM Doing same thing 11-Jan-20 02:58 PM Running spark plugs through aluminum base plate, waiting to start working on the plate this week 11-Jan-20 03:09 PM good news! i did not destroy the MKS901P most likely 11-Jan-20 03:09 PM analog output was showing ~8.88V (~760torr), testing it on trivac now, can't seem to get below 0.58torr, time to test other pieces 11-Jan-20 03:27 PM .5 torr is .6 mbar 11-Jan-20 03:27 PM try running your trivac for a while with the gas ballast open @samy 11-Jan-20 03:27 PM the oil might be wet 11-Jan-20 03:27 PM just block the inlet with a solid plate and let it run with the gas ballast open for a while 11-Jan-20 03:29 PM ok, thanks Spirit 11-Jan-20 03:29 PM meaning oil has water in it? 11-Jan-20 03:29 PM yes 11-Jan-20 03:29 PM k 11-Jan-20 03:29 PM running it for a while should dry it a bit 11-Jan-20 03:30 PM so it's okay to run the pump with just the sensor and nothing else to see if the issue is with the rest of my setup? 11-Jan-20 03:30 PM yeah, but I wouldn't put the sensor on directly and run it for a long time 11-Jan-20 03:30 PM oil mist does escape a little 11-Jan-20 03:32 PM ahh 11-Jan-20 03:32 PM very lucky with your 901P! thats good news 11-Jan-20 03:32 PM not so lucky with the pump but hopefully its just the oil 11-Jan-20 03:33 PM .5 mbar is still enough to back any high vac pump 11-Jan-20 03:33 PM shocked the sensor survived 12V to the analog out pins 11-Jan-20 03:33 PM if you did mess up the calibration you can calibrate it manually later 11-Jan-20 03:33 PM atmospheric command and high vacuum command(when you get below its minimum) 11-Jan-20 03:39 PM in atm it reports 739.6torr (8.869V) 11-Jan-20 03:45 PM 986mbar 11-Jan-20 03:45 PM so basically just a slightly uncalibrated maximum 11-Jan-20 04:55 PM k, ran gas ballast set to 2 for 30 mins, bunch of oil came out of the exhaust but not so much that the oil level looks different 11-Jan-20 04:57 PM got a better vacuum now? 11-Jan-20 04:57 PM (with it closed) 11-Jan-20 04:58 PM i was going to set up MKS901P to an MCU and OLED for display but interestingly the docs say to have the analog negative output floating and not grounded...so i think i'll need to buffer both the positive and negative, then resistor divider it (since it's up to 9V), then differentially compare via 2 ADCs 11-Jan-20 04:58 PM will test 11-Jan-20 04:58 PM yes, it must be floating 11-Jan-20 04:58 PM but you don't need the analog output! 11-Jan-20 04:58 PM it makes no sense to digitize something that's just shoved through a DAC in the gauge 11-Jan-20 04:58 PM it offers direct digital readout via rs232 11-Jan-20 04:58 PM just grab one of those premade converter boards through amazon prime or something 11-Jan-20 04:58 PM or if you have a MAX3232 sitting around you can use that 11-Jan-20 05:01 PM i tried two MAX3232's with no success, i think the voltage level is too low (i haven't validated via datasheet yet) 11-Jan-20 05:02 PM are you just soldering directly to it, or through a premade board? 11-Jan-20 05:02 PM i was able to do RS232 when i provided + and -12V and did the translation myself, but i don't want to have to also provide -12V 11-Jan-20 05:02 PM i tried two premade boards 11-Jan-20 05:02 PM the max3232 has a built in charge pump that just needs a few caps 11-Jan-20 05:02 PM generates the voltages itself 11-Jan-20 05:03 PM the caps are built in on the board (https://www.amazon.com/KOOBOOK-MAX3232-Converter-Adaptor-Transfer/dp/B07VNLVJ57/ref=sr_1_1?keywords=max3232&qid=1578790957&sr=8-1) 11-Jan-20 05:03 PM make sure they're correct 11-Jan-20 05:03 PM https://i.spirit.re/yRm7l.png 11-Jan-20 05:04 PM will validate, i just threw a voltmeter 7seg display on there for now 11-Jan-20 05:05 PM also, check your model number 11-Jan-20 05:05 PM could be rs485 11-Jan-20 05:05 PM though if you got 232 working with manual translation it's unlikely 11-Jan-20 05:05 PM should be 901p-11xxx 11-Jan-20 05:08 PM yup 11 11-Jan-20 05:08 PM rs232 then, hm 11-Jan-20 05:09 PM the issue seems to be on the 232 board, I'm clearly sending TTL UART to it and the 232 side receives nothing 11-Jan-20 05:11 PM could be a weird board 11-Jan-20 05:11 PM are you using the right inputs/outputs? 11-Jan-20 05:12 PM yeah, triple checked 11-Jan-20 05:12 PM RIN/ROUT and DIN/DOUT 11-Jan-20 05:12 PM also validated via continuity that they were tied to the right pins 11-Jan-20 05:13 PM ROUT going to RX, DIN to TX? 11-Jan-20 05:20 PM they have it labeled wrong on the amazon image, the TTL RXD and TXD should be swapped (but i wasn't following the image) 11-Jan-20 05:20 PM RS232 TXD -> DOUT2, 232 RXD -> RIN2, UART TXD (well the TTL RXD according to the image) -> DIN2, UART RXD (labeled TTL TXD in image) -> ROUT2 11-Jan-20 05:20 PM oh looks like they have both sides swapped on the image, but i wasn't using it anyway...i'll play with it a bit later 11-Jan-20 05:20 PM want to try setting up another chamber and also try making a decent cold trap 11-Jan-20 05:42 PM hmm i think i want to make a socket head for KF clamps so i can just use a drill to un/tighten 11-Jan-20 05:42 PM so much twisting 11-Jan-20 05:51 PM Let me introduce you to the world of quick release KF clamps 11-Jan-20 05:51 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Thyracont-ZubehC3B6r-ZSSR1016-2714-15-CCE5C.png 11-Jan-20 05:59 PM nice!! 11-Jan-20 05:59 PM do brass NPT ball valves hold a decent vacuum? 11-Jan-20 06:01 PM no, but there exist foreline pressure KF ball valves 11-Jan-20 06:01 PM https://www.ebay.com/itm/Ball-Valve-Vacuum-isolation-both-sides-KF16-flange-Stainless-Steel-Body-A53X-LW/172169127841 11-Jan-20 06:01 PM foreline pressure 11-Jan-20 06:01 PM https://www.ebay.com/itm/Manual-Angle-Valve-KF16-to-KF16-Vacuum-Pump-Flange-Fitting-Parts-New-A56M-LW/182093557265 11-Jan-20 06:01 PM manual high vacuum 11-Jan-20 06:01 PM https://www.ebay.com/itm/new-VAT-valves-series-265-KF16-vacuum-normally-open-valve-qty-available-mks/252705999883 11-Jan-20 06:01 PM pneumatic high vacuum. 11-Jan-20 06:01 PM can also use the manual high vacuum to throttle if you need to work with gases 11-Jan-20 06:27 PM @samy those amazon boards look identical to the ones i had overheat like a week ago... They seem lile fake clones or something that failed QC, or maybe made from recycled parts 11-Jan-20 06:27 PM ahh interesting 11-Jan-20 06:27 PM Could very well be that 11-Jan-20 06:27 PM i'll decap and compare to a digikey part 11-Jan-20 06:28 PM I couldn't even get anything out of them in loopback configuration 11-Jan-20 07:40 PM That quick release clamp looks pretty 11-Jan-20 07:40 PM Just wish there where KF clamps in this tri-shape: 11-Jan-20 07:40 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/HTB1vvvkNQvoK1RjSZFDq6xY3pXaB-DB945.png 11-Jan-20 07:40 PM (but that one is for triclamp, I am not sure if it would work well). 11-Jan-20 07:42 PM it should be fine 11-Jan-20 08:39 PM was able to get to 0.01torr after removing a bunch of extraneous stuff (no chamber tho) 11-Jan-20 08:39 PM with a bell jar on steel, is silicone the suggested material to use as a gasket between the two since viton is a bit harder and may not seal? 11-Jan-20 08:46 PM soft viton or vacuum rated silicone 11-Jan-20 08:52 PM k 11-Jan-20 08:52 PM 0.01 torr is good for your pump 11-Jan-20 08:52 PM your oil is fine 12-Jan-20 01:25 AM x10-3 is generally the lowest a roughing pump will go... getting into the low x10-2 is pretty good 12-Jan-20 01:25 AM if that roughing pump hasn't run for awhile you may have moisture in the oil limiting your ultimate pressure, try running the roughing pump for a few hours with the ballast wide open (on a closed chamber of-course) and see where you get, after a that few hours close the ballest and let it run a bit longer, then you should know your ultimate 12-Jan-20 01:25 AM fresh oil can help but if the oil in there doesn't look that discolored or nasty then yea other than a flush of the pump or a longer run-time with the ballest open your probably at the best you can get 12-Jan-20 03:56 AM @samy what pump do you have?. I think 0.01 torr is very good. I get to 0.1 torr with my mechanical pump. 12-Jan-20 07:00 AM ugh seems I'll have to do at-least minor rebuilds on most of my tested good D2As 12-Jan-20 07:00 AM the one I just got up on the bench and flushed seems good at first glance but I think the main seal is leaking, started pulling it apart and its pretttyyy nasty inside rusty wise, at-least need to figure out how to get a new balast filter because that thing was horrible 12-Jan-20 07:00 AM I believe its the same part as the D4A and wow is that expensive 12-Jan-20 07:00 AM https://www.idealvac.com/Leybold-Trivac-Heraeus-Rotary-Vane-Vacuum-Pump-D4A-Oil-Filter-Element/pp/P104532 12-Jan-20 07:13 AM Looking at rebuild kits I don't like the looks of them... it looks like they are missing crucial seals which basically are shot or get destroyed on opening the darn thing... which seems realllyyy sketchy 12-Jan-20 07:13 AM wish Duniway had a LIST of the parts that come in the rebuild kits as according to the manuals... 12-Jan-20 07:13 AM would really take out a lot of guess work or, just buy it and find out what your missing work 12-Jan-20 07:25 AM but yea I really would love to avoid needing all of my roughing pumps to have oil catch pans under them... and constantly needing to top them off... 12-Jan-20 08:00 AM well have a minor rebuild kit on the way see how that goes 12-Jan-20 09:48 AM @chucrut trivac d2.5e, this was without a chamber, just went through a hose to pressure sensor 12-Jan-20 09:48 AM thanks for the info Conmega 12-Jan-20 10:56 PM Good morning! 12-Jan-20 10:56 PM I got a quote for LN2, at 2.4 € per liter... :/ 12-Jan-20 10:57 PM for how much? does not seem too bad... 12-Jan-20 10:57 PM that seems cheaper than the 50L price ($2.83/L+$20 delivery) at the place closest to me 12-Jan-20 11:11 PM Oh, ok 12-Jan-20 11:11 PM yeah per Liter at 50 liters 12-Jan-20 11:11 PM I was expecting something half that tbh... 12-Jan-20 11:13 PM i mean, California is probably the most expensive state to get it (afaik) but thats what my local prices are 12-Jan-20 11:13 PM so i do not think you are doing too bad 12-Jan-20 11:13 PM http://www.cryotek.co/nitrogen-fills/ <- closest place to me (that i am aware of) 12-Jan-20 11:13 PM for 5L you are looking at $5/L 12-Jan-20 11:14 PM what do you guys think about this project? http://homemadeliquidnitrogen.com/index.html 12-Jan-20 11:15 PM the high pressure compressor side of things is more dangerous than the cryopump direction but definitely cheaper 12-Jan-20 11:15 PM depends if you are comfortable working with near 3000psi gases 12-Jan-20 11:16 PM It's a nice project, but just a bit too big for my basement ^^ 12-Jan-20 11:16 PM I'm already looking into GM cryocoolers at Home tho! 12-Jan-20 11:21 PM dang just did a quick check on the prices of those compressors and that is nuts 12-Jan-20 11:21 PM did not realize those high pressure compressors got so expensive so fast 12-Jan-20 11:22 PM Last I checked they were a little over $200 12-Jan-20 11:22 PM (the chinese ones) 12-Jan-20 11:24 PM those are not the oil free pumps as far as i could tell? 12-Jan-20 11:24 PM not sure you would ever get the air oil free enough with filtering to do any good for LN2 12-Jan-20 11:26 PM I suppose a coalescent air filter would be a start. Not sure how much oil would be left after that... 12-Jan-20 11:30 PM Joule Thomson coolers only really work well at huge scales 12-Jan-20 11:30 PM such as the one in that guy's tutorial 13-Jan-20 01:32 AM and I got an offer from linde 13-Jan-20 01:32 AM Bezeichnung  /  Preis Stickstoff, flüssig: 2,80 €/Liter Befüllung Kanne: 15,00 €/ Füllpunkt GGVSEB : 25,00 € Transaktionspauschale: 0,95 €/Rechnung 13-Jan-20 01:32 AM many money 13-Jan-20 01:32 AM 2.8€/ liter plus a fixed cost of 15 + 25 + 0.95€ 13-Jan-20 02:48 AM Thats expensive 13-Jan-20 02:48 AM I pay about 50 eurocents per litre 13-Jan-20 02:59 AM but i have to say making it DIY is probably not that much cheaper, for sure it is a fun project but just from a cost perspective dose not make much sense if you can get it commercially 13-Jan-20 03:06 AM It really depends on your local power cost and the volume you use I think 13-Jan-20 03:08 AM just going from electricity cost diy should end up at 1.5 to 2 bucks per liter 13-Jan-20 03:08 AM @pbx/peterbjornx how much / where? ^^ 13-Jan-20 03:09 AM Uni 13-Jan-20 03:10 AM ah, well, that's a different story 13-Jan-20 03:10 AM They also sell externally I think 13-Jan-20 03:10 AM jup 2€ is also what i found to be reasonable from my test but the cost of the equipment is quite significant, and you do not want to condensate Oxigen so you should filter that 13-Jan-20 03:10 AM @GigaSquirrel cant you also get it form the local Uni? or vet? 13-Jan-20 03:13 AM I could get it from my uni, but it's not a reliable source (depends on the day my Prof is having) and it's a nightmare to get home, as the liquefier is in the middle of a densly populated city 13-Jan-20 03:13 AM Buying really is the easiest way for me, until I have my own liquefier 13-Jan-20 03:14 AM ok here it was never a problem got it form the lab technician and if you bring your own dewar was very easy and cheap 13-Jan-20 03:14 AM yes transport is a problem they are quite big i used bike trailer to transport it 13-Jan-20 03:16 AM I know a few lab techs who will even give it for free if you bring a small dewar! 13-Jan-20 03:16 AM At my uni theres a cryo dept. that exists solely to produce and distribute ln2/ liquid helium 13-Jan-20 03:17 AM @Mason_Yu thats rigth 13-Jan-20 03:19 AM But generally I ask some people at my volunteer job (science '"shows" at high schools, run by students) if i can fill my dewar from their 100L one 13-Jan-20 03:22 AM now that im finished with uni i looked around, and my local vet gets LN2 for Animal insemination from a service company and twice per month they come to refill and i can just show up with my flask and get 25l for 20€ that is really good deal 13-Jan-20 11:25 AM https://www.ebay.com/itm/IXRF-Systems-Model-5480-Imaging-Interface-/392274053634 13-Jan-20 11:25 AM Does anyone here know what this little box does? 13-Jan-20 11:25 AM I really hope it has DACs inside to do digital beam control. I sent an email to IXRF and they've not replied 13-Jan-20 11:27 AM mm, i should call around and figure out LN2 prices too 13-Jan-20 11:27 AM I wish you guys lived near me... give me a REASON to complete my LN2 generator 13-Jan-20 11:42 AM @qualia so in what condition are your sillys, can one be used as is? 13-Jan-20 11:42 AM @Conmega regardless of that, you should get some detectors that need LN2 as well xD 13-Jan-20 11:43 AM ah, so, i poked at the one with the good window a bit.. hooked it up to amp power and the signal output voltage swung quite high 13-Jan-20 11:43 AM tried putting around -20VDC on bias and I could not actually pick up any noise or anything.. 13-Jan-20 11:44 AM does it have an integrator output? 13-Jan-20 11:44 AM @GigaSquirrel I have one on my small SEM I have yet to need to get running, and if I do I will probably use for lithography 13-Jan-20 11:44 AM i do not know 13-Jan-20 11:44 AM I also need an amp for that EDS if I get that SEM going 13-Jan-20 11:44 AM oh, wait, like, would that be why it swung high? the integrator just overflowed? 13-Jan-20 11:44 AM hmm 13-Jan-20 11:44 AM I got that SEM for like 150 bucks because the guy that bought it only wanted one part 13-Jan-20 11:44 AM he was going to part it all out but I told him to take the part, the cash and shoo 13-Jan-20 11:44 AM its just a little 175 dollar keithly amp 13-Jan-20 11:45 AM noice 13-Jan-20 11:45 AM This is what basically every preamp looks like 13-Jan-20 11:45 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-AE62A.png 13-Jan-20 11:45 AM in your case the detector polariisation is flipped, that's got to do with the tickness of dopant layers 13-Jan-20 11:45 AM so there's the integrator, differentiator and amplifier 13-Jan-20 11:45 AM if there's a DC current through the detector (if it's warm and not broken) the integrator output will saturate 13-Jan-20 11:45 AM in regular condidion the integrator output is basically just a function of energy * detection rate, hence the "RATE" led, that warns the user in case of a integrator saturation 13-Jan-20 11:52 AM wish this thing had status LEDs :D 13-Jan-20 11:52 AM lemme try again 13-Jan-20 11:56 AM ah, fair enough 13-Jan-20 12:03 PM yeah so.. if i connect the output of the detector to my 'scope, and apply amp power to it -- nothing else connected, no biasing -- output swings to 10V 13-Jan-20 12:03 PM mind, the dewar's not attached, and there's just some foil on top, so perhaps there is a light leak or something causing a photoelectric current or smth? 13-Jan-20 12:03 PM either way, applying a bias does nothing 13-Jan-20 12:04 PM yeah the lightleak sounds plausible 13-Jan-20 12:04 PM does it rise slowly-ish or does it just go bang to 10V? 13-Jan-20 12:05 PM Do HPGes work at high temps at all? 13-Jan-20 12:05 PM nope 13-Jan-20 12:06 PM slams up to 10V, slowly decays down on amp power removal 13-Jan-20 12:06 PM so either a big light leak or a broken preamp 13-Jan-20 12:06 PM I don't really see a way where a broken detector would cause that 13-Jan-20 12:06 PM can you maybe swap preamp? 13-Jan-20 12:07 PM maybe 13-Jan-20 12:07 PM or is it "really in there"? 13-Jan-20 12:07 PM it 13-Jan-20 12:07 PM oh and also do you get microphonics 13-Jan-20 12:07 PM https://www.youtube.com/watch?v=xw9jvHbp9BE 13-Jan-20 12:07 PM aren't hpge preamps just... a flappy fet in cryo? 13-Jan-20 12:08 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-396EA.png 13-Jan-20 12:08 PM That is not a flappy fet in cryo 13-Jan-20 12:08 PM The fet in cryo is Q1 13-Jan-20 12:09 PM it is 13-Jan-20 12:09 PM nope, no microphonics 13-Jan-20 12:09 PM the other SiLi detector has a broken window, so i'm also liable to have lightleak issues there 13-Jan-20 12:10 PM no micrphonics are actually a good sign 13-Jan-20 12:10 PM kinda 13-Jan-20 12:10 PM and it's sort of furled up in baggies rn so i can figure out how to clean it safely -- i think it was a polymer window, not beryllium, but want to be sure 13-Jan-20 12:10 PM that means your preamp is broken, doesn't say the crystal is broken 13-Jan-20 12:11 PM Hopefully not the fet 13-Jan-20 12:11 PM I've been told they die from a sneeze 13-Jan-20 12:11 PM the fet is less of an issue than the crystal 13-Jan-20 12:11 PM https://carlwillis.wordpress.com/2011/09/16/hpge-detector-part-i-repair/ 13-Jan-20 12:14 PM drilled a hole in the dewar to pump it down.. courageous 13-Jan-20 12:15 PM yep... 13-Jan-20 12:15 PM got the same hpge here, with dead fet as well... 13-Jan-20 12:15 PM trying to find a better way to pump it 13-Jan-20 12:16 PM Down the hall, a co-worker had an old GeLi detector he had managed to keep going continuously for over 20 years. Those rely on Li atoms drifted into the Ge, and they drift out if the detector ever warms up above LN2 temperatures. When he retired, the manufacturer of that detector, Princeton Gamma Tech, sent him a gold-plated lithium drifting rig as a souvenir. It seems he actually had the oldest such detector still in use. Amazing what a lack of budget for new equipment can accomplish, lol. 13-Jan-20 12:16 PM amazing :D 13-Jan-20 12:17 PM XD 13-Jan-20 12:17 PM Nice 13-Jan-20 12:18 PM I wonder how they're made and shipped 13-Jan-20 12:18 PM http://93.174.95.29/_ads/7186A2A2378050B1B6F3E2E085FFBD12 13-Jan-20 12:18 PM heated until the right drifting depth is reached, cooled down and shipped cold 13-Jan-20 12:18 PM " Lithium-Drifted Germanium Detectors: Their Fabrication and Use: An Annotated Bibliography" 13-Jan-20 12:18 PM was just looking that up haha 13-Jan-20 12:19 PM But how do you ship something at LN2 temps 13-Jan-20 12:19 PM in LN2 13-Jan-20 12:19 PM with a person holding a handcuffed dewar? 13-Jan-20 12:19 PM :D 13-Jan-20 12:20 PM nah gelis are old enough, they're from back when the postal system still did what it was suppsed to do 13-Jan-20 12:21 PM This is a really neat paper 13-Jan-20 12:21 PM https://arxiv.org/pdf/1807.07912.pdf 13-Jan-20 12:21 PM DIY-ish SiLi 13-Jan-20 12:21 PM With a respectable, but kinda crappy, 3.9keV FWHM at Am-241 13-Jan-20 12:36 PM @qualia I removed a beryllium window simply with gloves on, scraping tools, on aluminum foil to catch everything UNDER a piece of clear plastic/saran wrap, with a face mask on. pretty much just keep it away from your face 13-Jan-20 12:36 PM then I just balled up the foil and saran wrap, threw it away and took my gloves off carefully 13-Jan-20 12:39 PM most of the beryllium remediation literature i've read up on so far involves lots of what is precisely referred to as 'sticky tape' 13-Jan-20 12:39 PM but yeah it seems doable, with some caution 13-Jan-20 12:40 PM I mean yea if you want to go nuts... I mean I just had the saran wrap over top and honestly that has enough static cling to catch anything that TRYS to go airborn but most of what I got was like breaking silicon wafer... its mostly just thin bits that have a really hard time going airborn, just can be stabby 13-Jan-20 12:40 PM but honestly the bits are so fragile/small, not quite sharp enough to go through even harbor freight nitrile gloves... 13-Jan-20 12:40 PM you'll be fine 13-Jan-20 12:40 PM if you really wana be safe... outside down-wind 13-Jan-20 12:40 PM but I did it on my bench inside 13-Jan-20 12:43 PM i always wanted to taste it, when i was younger 13-Jan-20 12:43 PM 'sweet metal' seemed really novel to me 13-Jan-20 12:43 PM shame about the high-octane carcinogenity 13-Jan-20 12:52 PM yeaaaa 13-Jan-20 12:52 PM and the whole it never ever leaves your body 13-Jan-20 12:52 PM maybe a death bed bucket list item 13-Jan-20 12:52 PM lol 13-Jan-20 12:52 PM actually thats not all that bad of an idea 13-Jan-20 12:52 PM if your like about to be "unplugged" or something 13-Jan-20 12:52 PM bring me some beryllium, I'm tastin that now. 13-Jan-20 12:52 PM BUT GRANDPA YOU WERE PUT IN HERE BECAUSE YOU TASTED IT THE OTHER DAY YOU SENILE MADMAN 13-Jan-20 12:52 PM lol 13-Jan-20 12:54 PM XD 13-Jan-20 12:56 PM that's up there with 'I wonder if breathing pure radon makes your voice REALLY DEEP' 13-Jan-20 12:57 PM is radon heavier than SF6? 13-Jan-20 12:58 PM depends on how much you've got of them both 13-Jan-20 12:58 PM oh wow yea sf6 is like 186g/mol and radon is like 222 13-Jan-20 12:58 PM jeez 13-Jan-20 12:58 PM @qualia I better see this stuff being written down on that bucket list I want youtube videos if I'm still alive and youtube still exists 13-Jan-20 12:58 PM lol 13-Jan-20 01:00 PM :D 13-Jan-20 02:03 PM I wonder if you can use a silly at room temperature on one of the poles 13-Jan-20 02:03 PM average high of 2°C in june 13-Jan-20 02:07 PM you can definitely use one at -70 13-Jan-20 02:07 PM maaaaaaybe at -40 13-Jan-20 02:35 PM i have enough peltier to get down to -40ish, hmmm 13-Jan-20 02:36 PM The -70 silly detectors are also peltiers 13-Jan-20 02:37 PM you can get way lower in a vacuum than -40 13-Jan-20 02:37 PM fun fact, -40 °C is -40 °F, I learned that in stargate XD 13-Jan-20 09:35 PM Am I correct in assuming that pneumatically actuated valves have binary states? ie. No practical way to proportionally open/close them? 13-Jan-20 10:22 PM @GigaSquirrel I learned that in Antarctica as a son of Florida that grew up in Surf City, CA. My fiancee pointed out that most Alaskans learn this in kindergarten and thus I am only at least as smart as an 5yo in Fairbanks. Our love is a special love. 13-Jan-20 10:23 PM I just got a quote for Comsol 13-Jan-20 10:23 PM Bare comsol is just a hair over $12k 13-Jan-20 10:23 PM everything Is ~$220k for a single user 13-Jan-20 10:23 PM whoops. 13-Jan-20 10:52 PM @funranium right, I totally forgot about your trip there! How often did you stand at the north pole and thought to yourself "Things can only go south from here..."? 14-Jan-20 12:41 AM Spirit: you know it is pretty easy to find comsol installer images, right? 14-Jan-20 12:41 AM Not as legal, but if it is for personal use it should be ok 14-Jan-20 01:53 AM @pbx/peterbjornx but you'd never be able to boast to your geek friends about how much it's worth without getting a quote 14-Jan-20 01:53 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/15789957071954860712820592223661-0D47B.jpg 14-Jan-20 01:53 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/giphy-D8127.gif 14-Jan-20 08:43 AM Really, the joy at the South Pole was laying out the time zones around the geographic pole, getting your cocktail, and saying “It’s 5pm somewhere.” And then walking to the correct zone for a drink. 14-Jan-20 09:02 AM nice 14-Jan-20 10:11 AM @pbx/peterbjornx of course :v 14-Jan-20 10:11 AM I asked comsol about getting a hobby license and they just said that they don't have one and sent me quotes for regular and edu 14-Jan-20 10:26 AM @Deleted User corporate trolling, lol 14-Jan-20 10:26 AM $220k though 14-Jan-20 10:26 AM ouch 14-Jan-20 10:26 AM Obviously nobody buys all the modules 14-Jan-20 10:26 AM But still 14-Jan-20 11:19 AM tax financed facilities do 14-Jan-20 02:49 PM Have you tried OpenFOAM? 14-Jan-20 02:49 PM or Salome 14-Jan-20 03:04 PM i don't use comsol for CFD 14-Jan-20 03:09 PM Code_aster? Code-saturn? 14-Jan-20 03:09 PM I don't think there's an E&M solution for that open source ecosystem 14-Jan-20 04:52 PM @Nixie did you turn your mechanical feed through glass on a lathe? To make a flat edge for a gasket/o-ring? 14-Jan-20 04:53 PM you can't turn glass like that 14-Jan-20 04:53 PM only shape it when soft, or grind 14-Jan-20 05:36 PM Wow. I just had to pay $91 for a single bottle of TEOS from eBay. That stuff used to be cheap and common. I use it on my reduction furnace boats to hold the magnesium oxide coating on. Also makes a good binder for muting powders on metals that get hot in vAcuum 14-Jan-20 07:19 PM <__ice9#6039> I remember looking for that a while ago as well, though I don't recall why anymore. Cost was prohibitive. 14-Jan-20 07:19 PM <__ice9#6039> Sources of cheap chemicals: Right Price Chemicals (solvents), Duda Diesel (acids/bases/salts), HiMEDIA on Amazon (random specialties). Lab Alley is ok for things difficult to find elsewhere, but more costly. 14-Jan-20 07:19 PM <__ice9#6039> eBay always worth checking as well 14-Jan-20 07:19 PM <__ice9#6039> Carolina Chemical and Consolidated Chemical & Solvents also show up on Amazon fairly often and have their own sites with sometimes differing pricing. Would class them with Lab Alley-- a bit more costly but sometimes have uncommon items. For instance the bottle of trichlorobenzene I bought a while ago for dissolving some stubborn plastic came from one of them. 14-Jan-20 07:19 PM <__ice9#6039> If you are planning a large order, BioMall.in looks interesting, but I have not had enough items queued up at once to justify trying it yet-- so I am uncertain about reliability. They carry many things that are comparatively inaccessible in the U.S. retail chemical market. 14-Jan-20 07:34 PM This small amount will last me a long time, or to look at it another way it will go bad before I use it up. It reacts with moisture from the air so it’s got a limited life anyways. I only use a few tens of ml at a time and it’s a 1L bottle. 15-Jan-20 12:47 AM @Deleted User I've seen people use glass test tubes on a lathe, and shape with hot torch and a knife/etc 15-Jan-20 12:47 AM sure, hot is the key 15-Jan-20 12:47 AM heat it up and you can mold it 15-Jan-20 12:48 AM yeah, I was just wondering if that's what nixie did 15-Jan-20 12:48 AM or if they used some compression gasket around the circumference 15-Jan-20 12:48 AM like the easy-insert tubing connections on gas lines 15-Jan-20 12:48 AM or something 15-Jan-20 12:57 AM @nmz787 yes: 15-Jan-20 12:57 AM https://www.youtube.com/watch?v=FWOOiykhaFw 15-Jan-20 12:57 AM (same process as that one, but thinner glass, I just didn't record it) 15-Jan-20 12:58 AM do you think there's enough torque through the connection to unscrew a bolt from a nut? 15-Jan-20 12:58 AM wait, what? 15-Jan-20 12:58 AM thinking to have a closed nut with reagent in it, and unscrew it to release at the right time 15-Jan-20 12:58 AM Ah 15-Jan-20 12:59 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/61WadfAeY5L-E417F.png 15-Jan-20 12:59 AM something like that 15-Jan-20 12:59 AM I am not sure if the nut threads won't just become a problem. 15-Jan-20 12:59 AM that'd be inside the chamber 15-Jan-20 12:59 AM Yes, exactly. 15-Jan-20 01:00 AM so far it seems like a wire shoved through a rubber stopper, rotating, doesn't foul my vacuum... but we're still in the single-digit torr 15-Jan-20 01:00 AM either they are going to have air trapped in them, or the reagent evaporate through them. 15-Jan-20 01:00 AM so it could very well be messing things up going forward 15-Jan-20 01:00 AM yeah, rate is most concerning at this point I think 15-Jan-20 01:00 AM completely cutting it off isn't strictly required 15-Jan-20 01:01 AM as long as the wire is polished to a mirror finish, a compression o-ring should do the trick. 15-Jan-20 01:01 AM (just means less efficient reaction, more waste reagent) 15-Jan-20 01:01 AM still hoping to give the fuel injector a try... but a wire shoved through the rubber stopper is so much simpler at first glance 15-Jan-20 01:01 AM melting glass also seems like a fun project to break in my lathe 15-Jan-20 04:26 AM <__ice9#6039> Just use a PFA valve 15-Jan-20 04:26 AM <__ice9#6039> It's simple to open a ball valve with a rotary feed-through, and you can find PFA/PTFE valves for 10mm tubing and similar all over eBay cheaply from surplus dealers. PTFE and FEP tubing are also very cheap from China, recommend getting 6/8/10mm and using quick-connect fittings (John Guest clones) -- interchangeable with PE tubing for light duty applications. Have built loads of stuff using these. 15-Jan-20 04:26 AM <__ice9#6039> If you want that rotating stopper to seal well, use something like Dow Corning high vac grease. I've gotten below 50 micron with an entire endcap nitrile gasket covered in it before. It's not really UHV suitable, but it's fine for stuff like this. 15-Jan-20 04:26 AM <__ice9#6039> I second the note on oxyfuel torches making boro glass manipulation much nicer. pseudo-MAPP (propylene) air torches seem just barely hot enough, too easy to end up with cracks or lots of internal stress. 15-Jan-20 04:26 AM <__ice9#6039> Boro glass should be annealed at about 500C after reshaping 15-Jan-20 06:03 AM @__ice9 searching eBay for pfa ball valve turns up nothing below like $80 15-Jan-20 06:55 AM <__ice9#6039> Depending on the constraints of the reagent container, perhaps one of these might also work? 15-Jan-20 06:55 AM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/1579100138877-F2B6A.png 15-Jan-20 06:55 AM <__ice9#6039> https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F202873507139 15-Jan-20 06:55 AM <__ice9#6039> https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F182618072033 15-Jan-20 07:23 AM https://www.youtube.com/watch?v=bns8D9fN5M4&feature=share 15-Jan-20 07:23 AM Oops. Sorry. Wrong category!!! Hahaha 15-Jan-20 06:20 PM Hi. Nitrile orings are very cheap compared to viton. At which vacuum level nitrile is not a problem? 15-Jan-20 06:20 PM For 10^-5 torr is okay to use nitrile orings? 15-Jan-20 06:23 PM Viton isn't expensive 15-Jan-20 06:23 PM a meter of 7mm diameter is like $20 15-Jan-20 06:24 PM For 10^-5 torr is okay to use nitrile orings? 15-Jan-20 06:24 PM For 10^-5 torr is okay to use nitrile orings? 15-Jan-20 06:24 PM generally not 15-Jan-20 06:24 PM depends.... pumping speed, how much is being used, etc... 15-Jan-20 06:24 PM plain pre-vulcanized rubber is better 15-Jan-20 06:24 PM Here in Chile 1 meter is 40 usd 15-Jan-20 06:24 PM Nitrile is much cheaper 15-Jan-20 06:25 PM nitrile is not really suitable for vacuum 15-Jan-20 06:25 PM Do you mean UHV? 15-Jan-20 06:25 PM no, it's not suitable for -5 15-Jan-20 06:25 PM especially if you use a lot ofit 15-Jan-20 06:26 PM The outgassing is too high? 15-Jan-20 06:26 PM among other things 15-Jan-20 06:26 PM what are you trying to do? 15-Jan-20 06:27 PM I'm just curious. I already spent 200 usd in viton orings 15-Jan-20 06:28 PM did you buy them locally? 15-Jan-20 06:28 PM I was thinking about nitrile alternative 15-Jan-20 06:28 PM not going to work 15-Jan-20 06:28 PM save yourself the pain of troubleshooting and making it work 15-Jan-20 06:28 PM Yes. I bought viton locally 15-Jan-20 06:29 PM buy it overseas, it's much cheaper even with shipping 15-Jan-20 06:30 PM You are right. I have seen cheaper viton in Aliexpress 15-Jan-20 06:30 PM It takes 2 months to arrive 15-Jan-20 06:30 PM ask the sellers to ship with EMS :P 15-Jan-20 06:31 PM For this kind of things I would like to live in USA 15-Jan-20 06:31 PM You can find anything used for 10 usd 15-Jan-20 06:34 PM that's a gross generalization 15-Jan-20 06:34 PM you either spend TIME looking for something cheap, or MONEY getting something quick 15-Jan-20 06:34 PM its always a time vs money equation 15-Jan-20 06:34 PM and then there is gambling too 15-Jan-20 06:34 PM buying equipment used can be a big gamble, is the turbo OK or does it need bearings 15-Jan-20 06:34 PM and a lot of the time when you say buy a turbo for 100 bucks, if it needs bearings, for us hobbyests its not always worth spending the hundreds on rebuild kits, its more worth trying to buy another used turbo lol 15-Jan-20 06:34 PM but if you strike out too many times in a row you could have just rebuilt the first one 15-Jan-20 06:34 PM just realize people are more willing to come forth with success stories than failures so it may seem like an overwhelming number of cheap finds here are perfect 15-Jan-20 06:34 PM but there are an equal number of things that end up as scrap 15-Jan-20 06:37 PM You are right. Now I dont want to live in the USA 15-Jan-20 06:37 PM I prefer to stay here alone in my basement 15-Jan-20 06:42 PM ? I mean either way vacuum stuff is this way sometimes, can seem to start cheap but get expensive, you can use work-arounds but you will always be shaving off some performance or purity or whatever 15-Jan-20 06:42 PM and your outcome will be that slightly worse off 15-Jan-20 06:42 PM its a balancing act of budget/scale/goals/etc 15-Jan-20 06:42 PM and also time and patience 15-Jan-20 06:42 PM I know some people here have projects years in the making 15-Jan-20 06:42 PM you can either spend the dime today or the dollar tomorrow, maybe wait till tomorrow and get what you need 15-Jan-20 06:42 PM I am a hypocrite though because I can definitely be pretty impatient myself 15-Jan-20 06:42 PM I know I am slowly getting to the point where I would have rather spent my money on one working thing than 10 broken things... sometimes it gets that way 15-Jan-20 06:42 PM its all up to you and how you like to do things though, we are all different and all we can ever do is give eachother advice 15-Jan-20 06:46 PM Thanks @Conmega 15-Jan-20 06:46 PM I'm also taking years in getting all the parts 15-Jan-20 06:46 PM Maybe 6 years and a travel to China 15-Jan-20 06:55 PM 'murica ftw! 16-Jan-20 12:32 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200116_090450-9FD1B.jpg 16-Jan-20 12:32 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200116_090609-4BF70.jpg 16-Jan-20 12:32 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200116_091132-4613F.jpg 16-Jan-20 12:39 AM sweet! ln2? 16-Jan-20 12:41 AM Aye ^^ 16-Jan-20 01:06 AM https://youtu.be/zrwcymDDioU 16-Jan-20 04:27 AM woooot 16-Jan-20 05:00 AM DC sputter 200W (about 400V 500mA, 20 sccm Ar), from a germanium target 16-Jan-20 05:00 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-88949.jpg 16-Jan-20 05:00 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image1-BD208.jpg 16-Jan-20 05:00 AM Finished Ge (test sample on glass) 16-Jan-20 05:00 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-9AC9E.jpg 16-Jan-20 05:00 AM But there was a fail! There’s a problem with a big puck of germanium... 16-Jan-20 05:00 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-E841B.jpg 16-Jan-20 05:02 AM yeaaaa.... a lot of sputter heads include water cooling for a reason :s 16-Jan-20 05:02 AM I need to get my sputter head going, need to get a little chilling loop setup for it though 16-Jan-20 05:02 AM It was running normal cooling in the gun, it’s a professional gun 16-Jan-20 05:02 AM Might have been a bit too much power for Ge, thermal shock or expansion shattered it 16-Jan-20 05:03 AM ah I see 16-Jan-20 05:03 AM yea I have this little sputter head 16-Jan-20 05:03 AM https://photos.app.goo.gl/HLrvYYJQNgjXnFPf6 16-Jan-20 05:04 AM Cool 16-Jan-20 05:04 AM https://photos.app.goo.gl/gbKCqFooJG8BY13Y7 16-Jan-20 05:04 AM I need to figure out if the cooling path is just on the anode or if it bridges the anode and cathode... in which case I REALLY need to be careful with having my liquid non-conductive :) 16-Jan-20 05:04 AM I also don't know what the target material is... 16-Jan-20 05:04 AM If I get my EDS going on my SEM I can find out 16-Jan-20 05:10 AM So does anyone know what would cause a roughing pump's oil to start backstreaming like crazy? 16-Jan-20 05:10 AM To the level it completely drains the oil out of the pump into the foreline? 16-Jan-20 06:33 AM tempted to at here this 16-Jan-20 06:33 AM ANYONE IN THE UK 16-Jan-20 06:33 AM https://www.tester.co.uk/siglent-sds2102x-plus-super-phosphor-oscilloscope-2-channels-100mhz 16-Jan-20 06:33 AM TRY GO GET THIS 16-Jan-20 06:33 AM ITS FREE 16-Jan-20 06:33 AM GOD DAMN FREE 16-Jan-20 06:33 AM No idea if it'll work but daaaang you gotta try 16-Jan-20 06:37 AM for some reason the paypal window is always instantly closing when I try to pay 16-Jan-20 06:37 AM nope, it worked 16-Jan-20 06:37 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-33A04.png 16-Jan-20 06:42 AM Mine went through but i panicked and typo'd my email address 16-Jan-20 06:42 AM so I don't have an invoice lmao 16-Jan-20 06:42 AM rofl 16-Jan-20 06:44 AM if they work it out and reject it they gotta refund anyway xD 16-Jan-20 06:44 AM I mean even 100 euro in shipping makes it worth to the US lol 16-Jan-20 06:44 AM i'm UK so I ordered 4. Paid £4.95 16-Jan-20 06:45 AM although there is a mad deal on Arrow for a scope in the states right now, a rigol... I want to buy one of the two in stock when I get money though so uh... sorry I will keep that private 16-Jan-20 06:45 AM it may be on a forum somewhere though so you can find it 16-Jan-20 06:45 AM Well we'll find out in 2-3 days if it works 16-Jan-20 06:46 AM I am tempted to pay the 100 euro in shipping but ugh 16-Jan-20 06:46 AM its not as good as the rigol I plan to get so meh 16-Jan-20 06:46 AM tbh I don't think so 16-Jan-20 06:46 AM but still 16-Jan-20 06:47 AM hope you guys get it lol 16-Jan-20 06:47 AM there recently was something about some some keithleys for cheap but in the end people ended up with differential pressure sensors 16-Jan-20 06:47 AM some companies suck it up some (like arrow) get mad and tell you we won't ship you 4 dollars in chips for 5 cents, because we made a mistake an you can pay us the extra if you want. 16-Jan-20 06:47 AM the rigol I am talking about people legit got 16-Jan-20 06:47 AM They've now fixed the price on their site xDDD 16-Jan-20 06:48 AM it was a scope, with logic analyzer probes, 850 MSRP for 450 16-Jan-20 06:48 AM OH really already? lol 16-Jan-20 06:48 AM they just got a huge influx of orders from me and some friends 16-Jan-20 06:48 AM we all ordered about 4 each 16-Jan-20 06:48 AM meaning each order was worth £5400 16-Jan-20 06:49 AM OH LOL 16-Jan-20 06:49 AM I thought you got like one hahaha 16-Jan-20 06:49 AM lmao no 16-Jan-20 06:49 AM if you get 4 each you guys should sell them to friends for 100 bucks a pop :P 16-Jan-20 06:49 AM absolutely 16-Jan-20 06:49 AM I doubt we will though 16-Jan-20 06:50 AM for me like the whole site is dead now it seems 16-Jan-20 06:50 AM oh no there it goes 16-Jan-20 06:50 AM yea they fixed it 16-Jan-20 06:50 AM haha I doubt it to 16-Jan-20 06:50 AM maybe they hit the big red button to minimize damage 16-Jan-20 06:50 AM but funny mistakes 16-Jan-20 06:51 AM I just got an order confirmation 16-Jan-20 06:51 AM oh so you did? 16-Jan-20 06:51 AM I got mine right when I ordered 16-Jan-20 06:52 AM i think maybe the site just crashed for a while when sending my email. Not sure 16-Jan-20 06:52 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-8A723.png 16-Jan-20 06:52 AM Doubt they'll ship it 16-Jan-20 06:53 AM same 16-Jan-20 06:53 AM but hey 16-Jan-20 06:53 AM would be fun 16-Jan-20 06:53 AM well yeah xD 16-Jan-20 06:53 AM 'cause I really want those screwdrivers 16-Jan-20 06:53 AM XD 16-Jan-20 06:54 AM mood 16-Jan-20 07:45 AM so far I got no cancel notification 16-Jan-20 07:52 AM heh, speaking of 16-Jan-20 07:52 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-8A665.png 16-Jan-20 07:52 AM Expected: To be confirmed shortly 16-Jan-20 07:52 AM lol 16-Jan-20 07:53 AM yep... 16-Jan-20 07:59 AM Just had a call to say they've cancelled xD 16-Jan-20 08:00 AM I gave them my number without my countries prefix, got no call so far 16-Jan-20 08:01 AM I imagine they have quite a few numbers to go through lol 16-Jan-20 08:01 AM I love causing havock 16-Jan-20 08:03 AM lol 16-Jan-20 08:04 AM Good Afternoon [Me], You placed an order with us today for a Siglent SDS2102X Oscilliscopes, unfortunately this item was on our website at zero cost, but should have been on there for £899+VAT each. I am unable to supply this item at a zero cost so if you would like to go ahead with this, we would require an additional payment of £899+VAT. Alternatively, I can cancel this order for you if you would prefer? > I am sorry for any inconvenience this may cause. > Should you require any more assistance, please do not hesitate to contact me direct. > Please mark any correspondence, faxes or purchase orders for my attention. > Many Thanks Customer Services 16-Jan-20 08:09 AM haha I can feel the seething rage in those first few sentences as he has to stay serious 16-Jan-20 08:09 AM Good Afternoon [Customer Services], I already suspected that this offer was a mistake, but I could not pass up on it. Please go ahead an cancel the complete order. Regards, 16-Jan-20 08:15 AM "we would require an additional payment of £3596+VAT" 16-Jan-20 08:15 AM oof 16-Jan-20 08:24 AM F 16-Jan-20 08:28 AM Rip 16-Jan-20 08:28 AM Y'all got me excited 16-Jan-20 08:29 AM Okay I asked this before the whole free scope thing, but does anyone know what would cause a roughing pump's oil to backstream to a point it empties its reservoir and fills the foreline? 16-Jan-20 08:30 AM at least it wasn't as long as the last time with those keithleys 16-Jan-20 08:31 AM Anti suck back valve failure 16-Jan-20 08:31 AM It just lack of an anti suck back valve 16-Jan-20 08:33 AM Oh I didn't realize it would be this crazy without an anti suck back valve, but okay 16-Jan-20 08:34 AM oh it definitely is 16-Jan-20 08:34 AM https://www.youtube.com/watch?v=p8Nv9JcEp6k One of my first vacuum experiences XD 16-Jan-20 08:35 AM Oh Scheiße 16-Jan-20 08:35 AM heh.... 16-Jan-20 08:35 AM looks like dyno doesn't speak german xD 16-Jan-20 08:35 AM yea you know I didn't think about that, I kinda assumed he meant while it was running 16-Jan-20 08:35 AM but yea if he turned it off that would suck the oil back lol 16-Jan-20 08:35 AM with no anti suckback anyway 16-Jan-20 08:36 AM The pump has an anti-suck back valve I believe 16-Jan-20 08:36 AM https://www.energyconscious.com/yellow-jacket-bullet-anti-suckback-assembly-93647.html 16-Jan-20 08:37 AM well its not working I guess then if what happened was it turned off and oil came back into the chamber 16-Jan-20 08:37 AM if oil came back while it was running... then yea I Dunno 16-Jan-20 08:37 AM But yeah, at this point I think it's best for @Applied_Ion to get a pump from you 16-Jan-20 08:37 AM The pump was running dry for a while and was HOT 16-Jan-20 08:38 AM yea I have like 5 D2As which are the perfect size for small gas loads and are nice and quiet 16-Jan-20 08:38 AM I need to finish going through them, I had two I had tested with old oil and had good pressures, I tried getting one ready for my use and well... turns out it was leaking out a lot of seals 16-Jan-20 08:38 AM I am getting a minor kit from Duniway to find out if that fullfills replacing all seals or not... Duniway is bad at getting photos... 16-Jan-20 08:38 AM I hate they can't just get a good photo of their kits and get the right photos on the right products 16-Jan-20 08:38 AM its really stupid 16-Jan-20 08:43 AM Joined the server. 16-Jan-20 08:46 AM Good Afternoon [me], > Thank you for coming back to me. > Of course, I would have done the same. I have cancelled this order for you and processed a refund for the delivery charge. 16-Jan-20 08:49 AM I asked if they'd had many orders "yes we did have quite a few orders come through for this item." 16-Jan-20 08:50 AM lol no duh 16-Jan-20 09:23 AM BAHAHAHAH 16-Jan-20 09:23 AM Y'all would have had my envy for all eternity 16-Jan-20 10:49 AM I can't tell what that video is of 16-Jan-20 10:49 AM Looks like plasma 16-Jan-20 10:49 AM But inside the pump?? 16-Jan-20 10:54 AM Hi. There is any drawback of using copper instead of stainless steel inside a vacuum chamber? 16-Jan-20 11:04 AM As long as you keep it clean, it's fine 16-Jan-20 05:46 PM Aaaaaahhhhhhh 16-Jan-20 05:46 PM Credit to @GigaSquirrel for finding this 16-Jan-20 05:46 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-9ACD2.jpg 16-Jan-20 05:47 PM someone call the EPA 16-Jan-20 05:47 PM I’ll use a mask next time 16-Jan-20 05:47 PM Whole house contaminated with beryllium 16-Jan-20 05:48 PM Rich Feldman's store: everything ships with free berylliosis 16-Jan-20 05:48 PM Oh, I know who to call. 16-Jan-20 05:48 PM Let's give @funranium some conniptions. 16-Jan-20 06:21 PM OH HELLLLLLLLLLLLLLLLLLLLLLLLL NO At the moment, I am teaching industrial hygienists who have lived good and untroubled lives how to be beryllium workers. They want to know how I screwed up in life such that I know these things. 16-Jan-20 06:22 PM my friend did point out the difference is that is beryllium metal... beryllium oxide is like tons worse off in terms of getting airborne 16-Jan-20 06:22 PM still scary 16-Jan-20 06:23 PM I made a sign for exactly such situations. 16-Jan-20 06:23 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-2E752.jpg 16-Jan-20 06:23 PM Yes...BeO is worse. Worse is very relative. Let us hope he managed to get no metal slivers. 16-Jan-20 06:23 PM Because, hoo nelly, ain't nothing quite like a beryllium sliver to guarantee becoming beryllium sensitized. 16-Jan-20 06:23 PM Sorry, I have done far too much beryllium work, beryllium decon, and lost waaaaaaay too many coworkers to berylliosis. 16-Jan-20 06:50 PM Do you mean like a beryllium sliver implanted through your skin in a wound? 16-Jan-20 07:16 PM Yes. 16-Jan-20 08:36 PM <__ice9#6039> How are beryllium plates typically cut in industry? Dedicated water jet? Wire EDM under oil? Plasma and laser cutting would be extremely dangerous because of the liberated oxide dust plumes. Sawblades produce less outright dust, but would still leave a lot of dry coarse powder waste that would be difficult to ever fully clean. 16-Jan-20 08:36 PM <__ice9#6039> Mills would be similar as well. I'm assuming this stuff is only ever done by automated tools... one would hope. 16-Jan-20 08:36 PM <__ice9#6039> Larger structures are probably milled I suspect, unless one is using maybe sinker EDM 16-Jan-20 08:42 PM Glovebox maybe? 16-Jan-20 08:42 PM Some organisations machining Be are also machining, say, plutonium - so there’s relevant skills to use 16-Jan-20 08:45 PM <__ice9#6039> Hmm yes processes flinging strong-ish alpha emitter dust from reactive metals around probably have a lot in common 16-Jan-20 08:45 PM <__ice9#6039> The thought occurs to me that the dirty filters in EDM machines would become hazardous waste in their own right. A CNC mill in a glovebox might actually be safer depending on the full lifecycle analysis. 16-Jan-20 08:45 PM <__ice9#6039> Dust under oil is still safer than dust in open air, granted, and I suppose the filter housing probably keeps it contained. 16-Jan-20 08:52 PM The simple answer is, as far as I know, "dirty machines" 16-Jan-20 08:52 PM For plutonium, for example - parts of the machine that come in contact are probably discarded as low level waste, parts that are covered are decontaminated as much as possible 16-Jan-20 09:14 PM This reminds me of that time the Soviets accidentally blew up 4 tonnes of Be / BeO dust across a major city. https://www.newscientist.com/article/mg12817430-700-years-of-neglect-led-to-beryllium-blast/ 16-Jan-20 09:19 PM apparently I was half correct 16-Jan-20 09:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/1498173979-40DCD.png 16-Jan-20 09:19 PM https://permalink.lanl.gov/object/tr?what=info:lanl-repo/lareport/LA-UR-01-0313 16-Jan-20 09:19 PM even cooler 16-Jan-20 09:19 PM not discarded, just reused 16-Jan-20 09:55 PM @funranium more beryllium conniptions 16-Jan-20 09:55 PM this time from audiophools! 16-Jan-20 09:55 PM https://www.focal.com/en/focal-teach/beryllium-tweeter 16-Jan-20 09:55 PM aaaaaaaa! 16-Jan-20 09:55 PM side note: @GigaSquirrel cheap source of Be foil? 16-Jan-20 09:55 PM probably not vacuum tight though... 16-Jan-20 10:24 PM <__ice9#6039> Just use plasma or electrostatic methods imo (edit: to make tweeters, not to machine beryllium) 16-Jan-20 11:36 PM @Deleted User beryllium, much like asbestos, is a wonder material. It just has...drawbacks. It is to be used only when you absolutely must. 16-Jan-20 11:37 PM yeah 16-Jan-20 11:37 PM which is NOT there 17-Jan-20 12:10 AM @Deleted User this guys inheritance, peobably 17-Jan-20 12:15 AM lol 17-Jan-20 05:46 AM why is all the cool stuff deathly-dangerous to humans 17-Jan-20 07:06 AM A wash bottle and some liquid nitrogen makes a great little self-pressurised jet of cold nitrogen 17-Jan-20 07:06 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-B8531.jpg 17-Jan-20 07:07 AM and cold hands, by the looks of it 17-Jan-20 07:13 AM Not too cold 17-Jan-20 07:13 AM I was worried it would ice plug the tube then explode 17-Jan-20 07:16 AM sounds like there is a "but" coming 17-Jan-20 08:51 AM Anyone has any experience using liquid petroleum jelly as high voltage insulator? 17-Jan-20 08:51 AM Is like mineral oil for transformers? 17-Jan-20 10:34 AM Petroleum jelly is not a good insulator 17-Jan-20 12:10 PM when you know you got a package with HV parts in it: roommate: box came for you, ITS REALLY HEAVY, and small... and sounds like metal? 17-Jan-20 12:19 PM lol that's spot on 17-Jan-20 02:23 PM https://media.discordapp.net/attachments/499873492477411339/667843939705028636/DSC_2934.JPG 17-Jan-20 02:23 PM Some misc from ePay 17-Jan-20 05:15 PM lol "The management has dismissed this as ‘unrealistic’ because the plant has commitments to ‘thousands’ of factories in the Soviet Union. It would be more economical to build a new city elsewhere, the management says. " 17-Jan-20 05:15 PM from that 1990 beryllium blast article. 17-Jan-20 06:50 PM <__ice9#6039> This is somewhat interesting. I hadn't been aware that metal-to-metal seals existed for KF flanges-- https://www.idealvac.com/EVAC-Aluminum-Metal-Knife-Edge-Seal-NW40-KF40-for-UHV-Seal-PN-NW-40-MS-A/pp/P103402 17-Jan-20 07:16 PM weird 17-Jan-20 07:16 PM didn't know of that either 17-Jan-20 07:20 PM that seems like it would be very hard on the KF flanges 17-Jan-20 07:30 PM or make them one time use 17-Jan-20 07:30 PM lol 17-Jan-20 07:30 PM or oh they are aluminum 17-Jan-20 07:30 PM but they have the knife edge 17-Jan-20 07:30 PM huh 17-Jan-20 07:30 PM I suppose those are only for SS KF 17-Jan-20 08:49 PM Joined the server. 17-Jan-20 08:57 PM Welcome! 17-Jan-20 09:20 PM <__ice9#6039> Is there an alternative to stainless for KF...? All of mine and all of the listings I have seen are stainless, usually 304 if specified. 17-Jan-20 09:21 PM aluminum is fairly common too, from what i have seen 17-Jan-20 09:31 PM Yep, I have a few alu pieces 17-Jan-20 09:31 PM Copper and glass exist too 17-Jan-20 09:32 PM the inline VAT valves on eBay (from the failed sapphire plant(s)) are all aluminum body ones afaik 17-Jan-20 09:32 PM most are 17-Jan-20 09:32 PM yeah i am talking about just the KF16 inline ones there are tons and tons of on eBay 17-Jan-20 09:32 PM https://www.ebay.com/itm/VAT-KF16-normally-closed-vacuum-valve-26524-KA11-BKS1/254464187646 17-Jan-20 09:32 PM from the same place as a lot of the other KF16 gear heh 17-Jan-20 09:34 PM They are. Picked up several of the NC and NO ones. 17-Jan-20 09:36 PM yeah i bought some NC ones and got one with a nicked cable. seller sent a replacement that ended up being NO with an apology about how its his hobby biz and now i have an extra i guess? 17-Jan-20 09:36 PM not really planning to use the position sensor switch anyway 17-Jan-20 09:36 PM they said they have over 4000 of them which is just a crazy number 17-Jan-20 09:38 PM Yea the NO ones I got have quite a bit of wear. Not at all representative of the listing pic. >< 17-Jan-20 09:38 PM thats too bad, a couple had some scuffs but were not beaten up much and the flanges were perfect 17-Jan-20 09:39 PM Yea the flanges seem OK at least. Just deceptive is all IMO 17-Jan-20 09:39 PM yeah there were/are some listings with those that claim "new open box" 17-Jan-20 09:39 PM would be pretty upset if they were scuffed up if that was the condition the seller claimed 17-Jan-20 09:40 PM Picked up a few misc lots of CF/KF stuff the other week too and the seller just tossed them all in a box of peanuts. Several knicked knife edges but still a decent haul for the cost. 17-Jan-20 09:41 PM I found a trove of affordablish UHV stuff in Poland of all places 17-Jan-20 09:41 PM but I don't have anyone to negotiate or ship from there 17-Jan-20 09:42 PM oh yeah someone was asking about throttling a pneumatic actuated valve the other day and i was thinking it might be possible to do very simply on these valves with a 3d printed replacement for the position switch. something you could screw in or out to manually stop the shaft coming from the actuator 17-Jan-20 09:42 PM Yea I saw your translator request earlier. Wish I could help but I'm the typical monolingual merican 17-Jan-20 09:42 PM think they were asking about a gate valve tho...just figured i would mention the inline thing 17-Jan-20 09:42 PM I asked someone to send a request, but I don't know if they'll get a response 17-Jan-20 09:43 PM That was me. I'm new to the pneumatically actuated stuffs 17-Jan-20 09:43 PM I have a single pneumatically actuated vat valve 17-Jan-20 09:43 PM had to buy a bunch of pneu stuff to make a mini air station 17-Jan-20 09:43 PM lot of polish people have fairly passable english...i bet you could get by in email heh 17-Jan-20 09:43 PM but I bet they wouldn't like me dropping the price by 2/3 :P 17-Jan-20 09:44 PM depends on the sellers...i throw out super lowball offers on things at times expecting to get told where to stick it 17-Jan-20 09:44 PM I'm planning/hoping to use a spare airbrush compressor for my setup to be self contained/portable. Will 0robably goof with some of it tonight or tomorrow. 17-Jan-20 09:44 PM and instead the sellers accept and i have to figure out what to do with my new purchase 17-Jan-20 09:45 PM Still rebuilding that TPH-1500 though. Need to get it back together before I drop something on a blade or stator 17-Jan-20 09:45 PM the guy is selling amazing UHV systems with dozens of CF ports, some with viewports, for the asking price of around $1200 17-Jan-20 09:45 PM are you using those inline VAT valves? probably do not need a compressor on the system itself unless you are actuating the valves a ton 17-Jan-20 09:45 PM they have very very small volumes 17-Jan-20 09:45 PM I don't think they'll enjoy an offer of $180 for the chamber 17-Jan-20 09:45 PM closer to 1/10th the price lol 17-Jan-20 09:46 PM a one or two liter air reservoir would actuate those KF16 valves probably 100 times with lots of losses 17-Jan-20 09:46 PM Yea I plan to use those little kf16 VAT valves for my start/stop procedures but got a few other things too so I figured a small airbrush setup would fit nicely 17-Jan-20 09:46 PM the issue is pressure @LRM 17-Jan-20 09:46 PM you need serious pressure to actuate a lot of them 17-Jan-20 09:46 PM my vat gate valve wants at least 4 bar 17-Jan-20 09:47 PM Yea my airbrush setup is limited to like 60psi or so. Will see how well it does, not expecting any miracles though 17-Jan-20 09:47 PM I found that the $3.50 car air compressors push 15 bar if you let them 17-Jan-20 09:47 PM (don't) 17-Jan-20 09:48 PM i was planning to just use a small air tank w/ 120psi in it (little less than what my compressor goes up to) 17-Jan-20 09:48 PM pumps the volume of my vat valve(sizeable) up to 4-5 bar in a few seconds 17-Jan-20 09:48 PM so optimal for me, if a bit noisy 17-Jan-20 09:48 PM if my napkin math was half accurate for 2L it should be like 300 actuations per charge 17-Jan-20 09:48 PM on the KF16 ones 17-Jan-20 09:49 PM down to zero pressure? 17-Jan-20 09:49 PM no from 120 to 60psi 17-Jan-20 09:49 PM My fallback will be an air horn type tank pre-pressurized from my main compressor 17-Jan-20 09:49 PM Nice and compact but still pack a good punch 17-Jan-20 09:49 PM i did this awhile ago....do not think i have the math i did on the valves around anymore 17-Jan-20 09:49 PM the cheap car air compressor is palm-sized and it worked for me 17-Jan-20 09:49 PM so if you have a spare 12V, there's your solution 17-Jan-20 09:51 PM I want to definitely have a reservoir to handle any weird power failure situations, but primary power source is flexible since my rack unit has various psus 17-Jan-20 09:52 PM that reservoir I showed welding is for this exact purpose 17-Jan-20 09:52 PM to have a spare actuation or two with no power 17-Jan-20 09:56 PM dang their website did not want to load for me for a minute there but... http://www.vatvalve.com/en/business/valves/product?id=26524-KA41 17-Jan-20 09:56 PM "Volume of air cylinder in l 0.004" 17-Jan-20 09:56 PM pftew pftew 17-Jan-20 09:56 PM very tiny 17-Jan-20 09:56 PM exactly why i was saying to just use a tank and ~120psi 17-Jan-20 09:56 PM so many actuations even accounting for the volume of the tubing and everything 17-Jan-20 09:57 PM the air lines are like ten times larger than that 17-Jan-20 09:57 PM ha 17-Jan-20 10:01 PM i asked ages ago here and a few other places but still have not found anyone who is able to articulate the differences in the two main types of 3 way 2 position solenoids i am considering for using with the valves. what are you guys planning to use? 17-Jan-20 10:01 PM https://www.ebay.com/itm/183758096654 17-Jan-20 10:01 PM vs 17-Jan-20 10:01 PM https://www.ebay.com/itm/362656721556 17-Jan-20 10:01 PM aside from the fitting sizes (just grabbed the first two results that looked right) why the major physical differences? 17-Jan-20 10:01 PM the second ones i have used before but the first one would be a lot more compact... 17-Jan-20 10:13 PM For spring-return cylinders(single air line coming in) you want 2 way, or a 3 way with a plug 17-Jan-20 10:13 PM For double-acting cylinders, you want 3-way solenoids 17-Jan-20 10:15 PM Well the smaller valves are twice the wattage, and twice the switching speed 17-Jan-20 10:15 PM The idea here is that a 3 way solenoid has two lines - P and R, with an un-threaded release. The solenoid stays either in P or R, while the pressure out of the opposite tube is released. 17-Jan-20 10:15 PM I have some of the long ones, I believe they use the air pressure to amplify the electrical force 17-Jan-20 10:15 PM Essentially it's a pneumatic full bridge 17-Jan-20 10:15 PM actually I may have my terminology wrong 17-Jan-20 10:15 PM that would be 4 way 17-Jan-20 10:15 PM the electrical analogy works though 17-Jan-20 10:20 PM maybe i was not clear. i understand how they work and how to run the valves, just want to know what if any functional differences there are in the two solenoid styles 17-Jan-20 10:21 PM ways of actuation I believe 17-Jan-20 10:21 PM seems like they both do the same thing (3 way 2 position) but the vastly different form factors is what has me curious heh 17-Jan-20 10:21 PM nobody seems to know when to use one over the other 17-Jan-20 10:21 PM side note, the VAT pneumatic valves are pretty easy to manually operate with some vinyl tubing and locking pliers/forceps/a clamp if you get impatient 17-Jan-20 10:43 PM one is cheaper I guess 17-Jan-20 10:54 PM <__ice9#6039> Piloting pressure requirements sometimes make it infeasible to use these to simply redirect a stream of pressurized gas to one output port or the other. I don't recall the exact details, but essentially the valve would stick in one position and be unable to switch while pressure was present. It was apparently not designed for that use case. 17-Jan-20 10:54 PM <__ice9#6039> Context was a pressure swing adsorption oxygen concentrator 17-Jan-20 10:54 PM <__ice9#6039> A discretely piloted 3-way valve worked fine, though it was much more costly. 18-Jan-20 12:57 PM i just received a foreline trap and i'd like to clean it up a bit -- i'm guessing the shell is aluminum but i'm not sure, is that most likely? it's not magnetic and the in/out ports have been welded on 18-Jan-20 12:58 PM could be alu or stainless 18-Jan-20 12:59 PM yeah there are nonmagnetic stainless steels 18-Jan-20 12:59 PM the aluminum would be lighter for equal wall thicknesses 18-Jan-20 01:01 PM ah 18-Jan-20 01:01 PM What flange is this? Looks like KF but KF25/40 seem too small/big 18-Jan-20 01:01 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_8654-AB5CE.JPG 18-Jan-20 01:06 PM inner tube diameter doesn't really mean much 18-Jan-20 01:06 PM https://www.lesker.com/newweb/flanges/jpg/Photo_TechnicalNote_Figure6C.jpg 18-Jan-20 01:06 PM check these dimensions 18-Jan-20 01:09 PM moin! 18-Jan-20 01:17 PM ahh thanks 18-Jan-20 01:28 PM there still is kf32... ^^ 18-Jan-20 01:38 PM or it can be sharp G triclamp 18-Jan-20 01:44 PM nah, tri-clamp looks completely different 18-Jan-20 01:44 PM it's just discount KF 18-Jan-20 01:44 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Tri-clamp-ferrule-C0CF0.png 18-Jan-20 01:44 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/sanitarytri-clamp_fitting_110916_69-C0C7F.png 18-Jan-20 01:45 PM generally thats for like food processing right? 18-Jan-20 01:45 PM oh I've seen it the other way, where the gasket is shaped to overlap 18-Jan-20 01:45 PM I've seen it before 18-Jan-20 01:45 PM and yeah triclamp is food and brewing/distilling 18-Jan-20 01:45 PM yea I have a conflat to triclamp... 18-Jan-20 01:45 PM for whatever reason 18-Jan-20 01:46 PM a what now 18-Jan-20 01:46 PM 2.75" conflat to like a KF40 sized triclamp 18-Jan-20 01:46 PM that is very questionable 18-Jan-20 01:46 PM triclamp should be a great alternative for foreline stuff though, it's much cheaper than KF 18-Jan-20 01:51 PM does the gasket mainly seal against the angled surface of the knife edge or what? 18-Jan-20 01:51 PM for CF? yes 18-Jan-20 01:51 PM the knife edge crushes it and that's where the seal is 18-Jan-20 01:51 PM maybe that is an option for what samy was asking about the other day? 18-Jan-20 01:52 PM hm? 18-Jan-20 01:52 PM he was asking how hard CF knife edges are to turn 18-Jan-20 01:52 PM they are quite hard, lots of angles 18-Jan-20 01:52 PM and need special cutters 18-Jan-20 01:52 PM its not that simple, its been discussed a few times before and yea 18-Jan-20 01:52 PM the angles are critical for a good seal 18-Jan-20 01:52 PM and getting in there with cutters can be a pain 18-Jan-20 01:53 PM yeah so maybe just a similar thing to the conflat-triclamp adapter that was mentioned would be an option for him instead 18-Jan-20 01:53 PM he wanted to do CF2.75 to KF16 i think 18-Jan-20 01:53 PM huh? 18-Jan-20 01:53 PM like I said keep an eye on eBay for CF2.75 to KF whatever 18-Jan-20 01:53 PM then get a KF whatever to KF16 18-Jan-20 01:53 PM honestly it's the cheapest quickest way 18-Jan-20 01:53 PM KF 25/40 coming off CF2.75 is most common from my searching 18-Jan-20 01:53 PM that lot I got with 3 CF2.75 to KF40s in the lot was like 100 shipped for all that stuff 18-Jan-20 02:04 PM the seller of the foreline trap told me it was CF2.75 -- i received it and it looks nothing like CF (granted i've only seen pics), one of the traps has the KF-looking pic I just sent which I think is KF40 18-Jan-20 02:05 PM the seller has no idea what he is talking about if he called that in your picture CF2.75 18-Jan-20 02:05 PM he probably thinks all stainless steel tubing is CF 18-Jan-20 02:06 PM yeah that's what it seems, i was expecting a bunch of holes for attachment...this is better though as this will be easy to turn 18-Jan-20 02:12 PM is that front face in the photo flat and just has the tubing set back into it a little? no knife edge or anything right? that would rule out it being a rotatable one someone cut the movable part off of...which is something i cannot imagine why anyone would do anyway 18-Jan-20 02:21 PM ok your mixing up CF/KF/etc... 18-Jan-20 02:21 PM conflat: 18-Jan-20 02:21 PM https://image.made-in-china.com/202f0j00VImUJQGBLeow/Vacuum-CF-Fixed-Rotatable-Conflat-Flange-Fittings-Full-Nipples.jpg 18-Jan-20 02:21 PM rotatable conflat the tube part connects to a knife edge but the bolt pattern is seperated for rotatable clamping 18-Jan-20 02:21 PM https://sep.yimg.com/ay/vacuumshopper/4-62-od-conflat-flange-44.gif 18-Jan-20 02:21 PM thats a rotatable blank 18-Jan-20 02:21 PM ISO KF/NW flanges 18-Jan-20 02:21 PM https://www.idealvac.com/files/images/kfflange1list.jpg 18-Jan-20 02:21 PM use a centering ring to hold an oring, then that gets clamped between two flat surfaces with a slight inset in the center to allow the centering to align properly 18-Jan-20 02:21 PM larger ISO flanges look like this 18-Jan-20 02:21 PM https://www.evpvacuum.com/wp-content/uploads/2018/05/3-17-300x221.jpg 18-Jan-20 02:25 PM not called KF too 18-Jan-20 02:25 PM just ISO63 for example 18-Jan-20 02:25 PM there are varying clamping schemes, this being the most common, similar to KF/NW but yea generally just called ISO63 18-Jan-20 02:25 PM http://www.lowener.se/e/images/components/ISO-vacuum-components.gif 18-Jan-20 02:25 PM ISO side view of how it works 18-Jan-20 02:25 PM it also has a centering ring, oring, and inset to hold the centering ring 18-Jan-20 02:25 PM https://www.lesker.com/newweb/flanges/flanges_technicalnotes_iso_1.cfm 18-Jan-20 02:27 PM ISO[diameter] is generally much larger 18-Jan-20 02:27 PM other clamping types for ISO can be seen here 18-Jan-20 02:27 PM so, review, Conflat: https://www.lesker.com/newweb/flanges/flanges_technicalnotes_conflat_1.cfm CF2.75" OR DN40CF ISO: https://www.lesker.com/newweb/flanges/flanges_technicalnotes_iso_1.cfm Smaller stuff: KF16 OR NW16 Larger stuff: ISO160 (I have also seen NW160) Triclamp: Are you making beer? Looks like KF/NW but with a half-round machined in it... Seriously probably not really worth it for HV stuff like we want to do. Other stuff? Probably weird stuff that is hard to find as far as I currently know, avoid it if possible. 18-Jan-20 02:27 PM Also put in #resources for when it ultimately disappears here. 18-Jan-20 03:13 PM nice 18-Jan-20 05:37 PM Stuff disappears from this room, but not resources? 18-Jan-20 05:48 PM no I mean as people talk in here and it scrolls by 18-Jan-20 06:25 PM <__ice9#6039> Triclamp is reasonably common in chemical processing as well. If you use a high pressure clamp and 316-filled PTFE gaskets, it's a nice way to make a hydrothermal reactor with less of a tendency to leak than the awful threaded Chinese ones. 18-Jan-20 06:25 PM <__ice9#6039> ISO-K clamps are much more trouble than ordinary KF. They have a tendency to just fall off while being tightened. I ended up having to resort to sticking thin pieces of nitrile rubber under the clamping surfaces to get them to stay in place during tightening. The result holds a good vacuum, but it took much more time than applying a KF clamp would have. 18-Jan-20 06:29 PM you do have to go around in a circle with them and make sure you keep even clamping pressure yes 18-Jan-20 06:29 PM there is a chain style quick disconnect of ISO though 18-Jan-20 06:29 PM harder to find used and more expensive overall though, which is odd, the machining would be simpler but the clamps are obviously much more complex 18-Jan-20 06:31 PM <__ice9#6039> Hmm yeah, definitely tried to do that; still fell off. I think it had more to do with the external shape of the DN100 ISO-K adaptor against the turbopump I was attaching it to 18-Jan-20 06:32 PM hrm 18-Jan-20 06:32 PM <__ice9#6039> Idk eventually resolved as noted 18-Jan-20 06:38 PM You want clamps with teeth that "bite" into the groove 18-Jan-20 06:38 PM Those don't fall off 18-Jan-20 11:10 PM @Applied_Ion so I had this bright idea 18-Jan-20 11:10 PM micro-hypergolic thrusters 18-Jan-20 11:10 PM even hypergolic MEMS 18-Jan-20 11:10 PM now to determine whether it's bright from an "up in flames" standpoint or whether it's actually a good idea 19-Jan-20 12:31 AM What is this, a rocket for ants!? 19-Jan-20 02:04 AM This reminds me of the story of HP inventing inkjet printers 19-Jan-20 02:04 AM Explosives were considered to eject the ink drop 19-Jan-20 02:04 AM Injecting a H2/O2 bubble at the ink drop site 19-Jan-20 03:27 AM https://pdfs.semanticscholar.org/4ee9/b0f46c6548d66ef1092cca281edef357d825.pdf?_ga=2.90091673.329640386.1579432983-228158951.1579432983 19-Jan-20 07:57 AM @Deleted User I actually don't really know much about hypergolic thrusters, however mems should be quite feasible. There is work on stuff like mems based resistojets 19-Jan-20 10:12 AM would someone happen to have the schematics for an EDAX 9900? i have most of the PCBs and was hoping to reuse them somehow 19-Jan-20 01:43 PM I can see it now. ACME brand printers. We put the bang, In banging out pages! 19-Jan-20 04:38 PM what does the '2.5' in Trivac D2.5E mean? 19-Jan-20 04:39 PM 2.5 CFM 19-Jan-20 04:39 PM ah 19-Jan-20 04:43 PM Or thereabouts, please refer to the actual pumping speed in the specifications 19-Jan-20 04:43 PM Sorry, should be cubic meter per hour, metric pump 19-Jan-20 04:45 PM ahh - i would think D10E would get lower pressure but seems D2.5E does 19-Jan-20 04:46 PM Yeah but a good working D10E should be able to back any high vacuum pump for your process. In fact, I am using a D10E to test the EXT255Hi right now 19-Jan-20 04:49 PM nice. i got the D2.5E, just don't like that it's 240VAC...will see if i can convert to 120 or not, saw a deal on D10E so wondering if i should try to swap this for another 19-Jan-20 04:49 PM not a big deal but just trying to reduce gear needed 19-Jan-20 04:54 PM Well, just monitor your foreline pressure to make sure it's not above the rated limit of ~10 Torr 19-Jan-20 04:54 PM The turbopumps with drag stages are very forgiving in that sense 19-Jan-20 04:54 PM I've got a nice big transformer with my SEM 19-Jan-20 04:54 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20200119_195808-8E130.jpg 19-Jan-20 04:54 PM And now that I have to lift all this stuff up stairs, I can understand why you would want to minimize your gear 19-Jan-20 05:00 PM heh yea 19-Jan-20 05:00 PM haha 19-Jan-20 05:27 PM @Mason_Yu do you have a SEM? 19-Jan-20 05:28 PM Yes, in my living room 19-Jan-20 05:28 PM Wow 19-Jan-20 05:28 PM Can I ask you how it generate the high voltage?. It uses flybacks or a cockroft walton multiplier? 19-Jan-20 05:28 PM Or both 19-Jan-20 05:31 PM Let me look at the circuit schematics 19-Jan-20 05:31 PM Thanks 19-Jan-20 05:31 PM Maybe you can take pictures of the schematic 19-Jan-20 05:32 PM The schematics are unlikely to help unless they have exact part numbers 19-Jan-20 05:32 PM High voltage supplies are deceptively simple on schematics 19-Jan-20 05:32 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20200119_203236-B9C1D.jpg 19-Jan-20 05:32 PM oh man, that is vintage 19-Jan-20 05:32 PM that's basically the functionality of a single chip in 2020 :P 19-Jan-20 05:33 PM Yeah, old scope, but you have the part numbers 19-Jan-20 05:33 PM in fact it's a good analogy 19-Jan-20 05:33 PM all the stuff to the left of "OIL TANK" are usually orderable in a single QFN package 19-Jan-20 05:34 PM Yeah not many integrated circuits on this one. I also need to replace the oil in the high voltage power supply, thanks for the reminder 19-Jan-20 05:34 PM Please, could you take a picture of the right part too 19-Jan-20 05:34 PM To see the output in the schematic 19-Jan-20 05:34 PM If you're thinking of building this, you shouldn't 19-Jan-20 05:35 PM That's not the spirit 19-Jan-20 05:35 PM it's an old circuit and again, not very representative of what it is in reality 19-Jan-20 05:35 PM transformers and multiplier for example 19-Jan-20 05:35 PM you're better off using a modern schematic and modern parts 19-Jan-20 05:36 PM Yeah, I have to agree with Spirit on this one 19-Jan-20 05:37 PM Please please please, take a picture of the right part of the schematic 19-Jan-20 05:37 PM I need to see the output 19-Jan-20 05:37 PM Alright 19-Jan-20 05:37 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20200119_203719-0ED8E.jpg 19-Jan-20 05:37 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20200119_203730-86CB8.jpg 19-Jan-20 05:37 PM Damn it's cutting off 19-Jan-20 05:37 PM Many thanks @Mason_Yu 19-Jan-20 05:37 PM Today I generated -50kv using a flyback and a CW multiplier 19-Jan-20 05:40 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/HV_supply_schematics-A6E60.pdf 19-Jan-20 05:40 PM Immersed in liquid petroleum jelly 19-Jan-20 05:40 PM Today I generated -50kv using a flyback and a CW multiplier 19-Jan-20 05:41 PM Petroleum jelly is not a good HV insulator 19-Jan-20 05:41 PM In the SEM schematic is interesting they used half wave CW, which have more ripple in the output 19-Jan-20 05:42 PM This is something you don't see on the schematic 19-Jan-20 05:42 PM Filtering 19-Jan-20 05:42 PM Full wave CW is more stable 19-Jan-20 05:42 PM It doesn't matter and is more expensive and complicated 19-Jan-20 05:42 PM SEM emission currents are very low, so ripple is not a big issue 19-Jan-20 05:42 PM Stability is 19-Jan-20 05:43 PM Full wave CW is more stable 19-Jan-20 05:43 PM No, it has nothing to do with stability 19-Jan-20 05:43 PM Stability is in regulation 19-Jan-20 05:45 PM I mean full wave CW have less ripple 19-Jan-20 05:45 PM It doesn't matter when you have enough filtering 19-Jan-20 05:45 PM Again, SEM emission currents are near zero 19-Jan-20 05:47 PM I mean full wave CW have less ripple 19-Jan-20 05:47 PM I mean full wave CW have less ripple 19-Jan-20 05:47 PM I mean full wave CW have less ripple 19-Jan-20 05:47 PM Yes, and it doesn't matter, please don't spam 19-Jan-20 05:47 PM Sorry, I have slow internet connection 19-Jan-20 05:48 PM Going from half-wave to full-wave rectification doubles your price and significantly increases your volume 19-Jan-20 05:48 PM You can see the filtering caps on the schematics I believe, they are pretty large and I think would be sufficient to eliminate any ripple 19-Jan-20 05:48 PM Yep 19-Jan-20 05:49 PM They would want to keep the oil tank as small as possible. Mind you, it's still by far the heaviest and bulkiest electronic box (aside from that transformer) in this SEM 19-Jan-20 05:50 PM with modern parts it's generally not oil submersed 19-Jan-20 05:50 PM (but potted) 19-Jan-20 05:50 PM I have 10kg of petroleum jelly 19-Jan-20 05:51 PM that is cheap 19-Jan-20 05:51 PM high voltage power supplies are not cheap 19-Jan-20 05:51 PM It works fine :) 19-Jan-20 05:51 PM until you measure it :) 19-Jan-20 05:52 PM No arcing 19-Jan-20 05:52 PM Leakage and other things 19-Jan-20 06:06 PM I should also mention that you don't really need a super high voltage for DIY SEM 19-Jan-20 06:06 PM 20-35kV is pushing the upper limit 19-Jan-20 06:07 PM From the schematics, there are two outputs: -25kv (negative output) +10kv 19-Jan-20 06:07 PM they are usually multi-purpose supplies 19-Jan-20 06:07 PM not just beam acceleration 19-Jan-20 06:07 PM focus, beam deflection(if electrostatic) 19-Jan-20 06:12 PM Is easier to repair 19-Jan-20 06:12 PM or you can just buy one you don't need to repair at all 19-Jan-20 06:12 PM https://www.ebay.com/itm/Matsusada-RB60-30P-30kV-60W-High-voltage-power-supply-Hochspannungs-netzteil/254438917823 19-Jan-20 06:12 PM something like this for example 19-Jan-20 06:12 PM (there are cheaper options, first one I found) 19-Jan-20 06:14 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20200119_211401-2C218.jpg 19-Jan-20 06:14 PM It appears my schematics are for a mix of two scopes of different models. I have the 30kV version and it is actually coming from a single supply 19-Jan-20 06:14 PM looks like there's two supplies in one 19-Jan-20 06:14 PM three, actually 19-Jan-20 06:14 PM filament, accel, and wehnelt 19-Jan-20 06:15 PM Yeah 3 different supply circuits, one tank 19-Jan-20 06:15 PM The other one has the 10kV portion out of the tank 19-Jan-20 06:15 PM But with modern potted supplies you don't need any of this lol 19-Jan-20 06:15 PM The thing is, it doesn't make sense to build them yourself when you can buy every single supply voltage you need on eBay for <$150-200 each 19-Jan-20 06:15 PM Tip to look out for: Applied kilovolts Matsusada Spellman Glassman 19-Jan-20 06:15 PM (in that order) 19-Jan-20 06:15 PM I've seen hundreds of Applied Kilovolts supplies, anywhere from 1 to 50kV, sold for under $50 each 19-Jan-20 06:15 PM Same with Matsusada 19-Jan-20 06:15 PM throw a few giant tank caps on them and you're basically done 19-Jan-20 06:15 PM and a lot of them are VERY well regulated 19-Jan-20 06:15 PM some even less than 0.01% 19-Jan-20 06:15 PM here's another, this one is total overkill at 50kV and over 1mA 19-Jan-20 06:15 PM https://www.ebay.com/itm/Hitek-Power-Mh-60-Series-MH60-503-03-High-Voltage-Versatile-Power-Supply/172863449515 19-Jan-20 06:20 PM Yeah unless you need crazy high power you don't want anything with oil in it 19-Jan-20 06:22 PM https://www.ebay.com/itm/APPLIED-KILOVVOLTS-HP-SERIES-HP020PZZ337-HIGH-VOLTAGE-POWER-SUPPLY/274103253624 19-Jan-20 06:22 PM these things are gold for DIY stuff 19-Jan-20 06:22 PM This one is a 1.5 kW, 0-30KV power supply 19-Jan-20 06:22 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20190621_151546-B54C6.jpg 19-Jan-20 06:22 PM yeesh 19-Jan-20 06:22 PM Unfortunately you can't see the interesting stuff inside that oil filled box 19-Jan-20 06:22 PM https://appliedkilovolts.com/docs/datasheets/HP.pdf 19-Jan-20 06:22 PM look at this stuff though 19-Jan-20 06:22 PM <300mV pk-pk ripple at 30kV @ 250uA load! 19-Jan-20 06:22 PM that takes serious design effort 19-Jan-20 06:22 PM meanwhile you can just grab one on ebay for $75, and there goes your entire SEM power supply problem 19-Jan-20 06:22 PM well, I say that, but it's just the base acceleration voltages 19-Jan-20 06:24 PM Hmm, that's actually potentially a solution for me 19-Jan-20 06:24 PM I don't want to haul this massive oil filled box around lol 19-Jan-20 06:24 PM just look for "applied kilovolts", "matsusada" and "spellman" 19-Jan-20 06:24 PM there's hundreds of them 19-Jan-20 06:25 PM Yeah, prices are not bad honestly 19-Jan-20 06:25 PM oh "Bertan" too 19-Jan-20 06:25 PM those are old but good 19-Jan-20 06:25 PM https://www.amazon.com/Voltage-Inhibited-Electrical-Insulating-Gallon/dp/B010V9KAAE 19-Jan-20 06:25 PM a voltage inhibited insulating gallon 19-Jan-20 06:25 PM Given how expensive tranformer oil is, this is even more attractive 19-Jan-20 06:26 PM https://www.ebay.com/itm/Matsusada-J4-3N-LXSH-High-Voltage-Power-Supply/333113876979 19-Jan-20 06:26 PM That 1.5kw 30kv supply is yours? 19-Jan-20 06:27 PM That's for capacitor charging, not the SEM lol 19-Jan-20 06:27 PM And yes, grabbed it for $200 (I think) 19-Jan-20 06:27 PM the 4kv matsusada should be good for your wehnelt 19-Jan-20 06:27 PM 2mV noise! 19-Jan-20 06:27 PM good luck designing that quickly at home 19-Jan-20 06:27 PM @Deleted User Perhaps move this to #swap-meet ? 19-Jan-20 06:28 PM Is too expensive? 19-Jan-20 06:28 PM I will, good idea 19-Jan-20 06:30 PM @chucrut I mean, how expensive it is depends on your perspective I guess. For me $200 is quite a bit but hey, it solved many problems 19-Jan-20 06:31 PM Put it in a box and send to me ASAP 19-Jan-20 06:31 PM Not for sale lol 19-Jan-20 06:33 PM https://www.ebay.com/itm/KAISER-SYSTEMS-LS1500-LASER-HIGH-VOLTAGE-POWER-SUPPLY-34kV-124mA-OUTPUT/391516034009 19-Jan-20 06:33 PM This is the model, it has quite a few voltage options 19-Jan-20 06:33 PM Why do you need so much power? Do you have gigantic caps? 19-Jan-20 06:33 PM Looks like it's a specific cap charging supply 19-Jan-20 06:33 PM Yeah 19-Jan-20 06:33 PM given that it says 1500J/s 19-Jan-20 06:34 PM This was for some big lasers, not what I'm using it for though 19-Jan-20 06:34 PM Laser power supplies generally works with positive high voltage 19-Jan-20 06:35 PM Oh, I guess you want to build a high power fusor then 19-Jan-20 06:35 PM You can flip the polarity on this supply I believe 19-Jan-20 06:35 PM https://fusor.net/board/viewtopic.php?t=8886 19-Jan-20 06:40 PM I will put an arduino in the petroleum jelly and I will be happy 20-Jan-20 02:37 AM Speaking of applied kilovolts 20-Jan-20 02:37 AM Weird HV connector. Like PL-259 but really recessed back for a long insulator 20-Jan-20 02:37 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-D51BF.jpg 20-Jan-20 02:37 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-2937F.jpg 20-Jan-20 02:37 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image1-D167A.jpg 20-Jan-20 02:37 AM 30 kV I think 20-Jan-20 02:37 AM Can’t see much of the good stuff, it’s all potted 20-Jan-20 02:37 AM Big ballast resistor (?) in the HV line 20-Jan-20 02:44 AM that's regular PL, but with the inner conductor punched out, Glassmann has the same connector 20-Jan-20 04:41 PM Joined the server. 20-Jan-20 05:06 PM Applied Kilovolts and other non-Japanese manufacturers are known for using hacky connectors :P 20-Jan-20 05:06 PM Even Spellman, they sometimes use BNC with looooooooots of(flexible) insulator sticking out 20-Jan-20 08:35 PM https://youtu.be/7ajF06z8ZEg 20-Jan-20 08:35 PM I love the casually sprinkled about giant turbopumps 20-Jan-20 08:57 PM “human inside” light, never seen that on a scope before lol 20-Jan-20 08:57 PM are there any other surface/analytical techniques that get scaled up in similar ways for auto industry or such? pretty interesting 21-Jan-20 12:47 AM I wonder if the piezo in the MKS-901p can serve as a discount baratron 21-Jan-20 12:47 AM It doesn't say much in the datasheet in regards to its accuracy 21-Jan-20 12:47 AM but it does say this: 21-Jan-20 12:47 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-A37B2.png 21-Jan-20 12:47 AM Ah, the spec page says it can! 21-Jan-20 12:47 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/TjBRw-54578.png 21-Jan-20 12:47 AM Perfect, +-5% from 10 to 100 torr. Just what I need for nixies. 21-Jan-20 01:15 AM I have seen a manual for a turbopump with a “do not get inside vacuum chamber” warning before 21-Jan-20 11:47 AM What the heck... I ordered a minor rebuild kit from Duniway like a week ago and its still "processing" ?!?? 21-Jan-20 11:47 AM Looks like maybe they want me to respond to this stupid email asking about more information about my buisness or school... Why... Just why... 21-Jan-20 11:52 AM It took us a month to get some silanes ordered, and that's with a legit business address and corporate email address 21-Jan-20 11:52 AM Apparently the company (not duniway) just sucks at paperwork or something 21-Jan-20 11:53 AM Jeez... well I just noticed the email asking for info is from sales tied to the purchase I made so I think I need to tell them, NO I'M A HUMAN LOOKING TO BUY STUFF FOR MY STUFF. Before they will process the order. 21-Jan-20 11:53 AM I'll humor them. 21-Jan-20 11:53 AM Hi Susan, I am not affiliated with any company or school. I am just an individual looking to purchase parts for my own equipment. I don't export anything, everything just stays in the US in my basement in Poughkeepsie, NY. Thanks, -Connor K 21-Jan-20 11:54 AM They want to know how hard to sell you on expensive stuff 21-Jan-20 11:54 AM lol they are doing a bad job at it 21-Jan-20 11:54 AM This was a test purchase just to see what the kit is since their photos suck... 21-Jan-20 11:54 AM Lately I've just been stating I'm a sole proprietor, rather than an individual 21-Jan-20 11:54 AM they aren't ever of the actual product or kit... 21-Jan-20 11:54 AM just some other similar thing 21-Jan-20 12:27 PM Duniway is not as good as they used to be. 21-Jan-20 12:28 PM unfortunately they are the only source for some of this stuff 21-Jan-20 12:28 PM for a decent price anyway 21-Jan-20 12:47 PM Yeah I have problems getting duniway to ship quickly sometimes 21-Jan-20 12:47 PM It's kinda annoying 21-Jan-20 12:47 PM Sometimes it ships almost immediately. Other times it's just not moving for an unknown reason 21-Jan-20 02:02 PM Joined the server. 21-Jan-20 02:10 PM Hello new people from another server that I definitely do not know 21-Jan-20 07:55 PM Toxic flammable gas shipments gets DOT very excited and depending on your jurisdiction, this may involve a call to your local county fire department to make sure that you are a licensed & inspected facility. No one wants to be known as the supplier to the next Radioactive Boy Scout. 21-Jan-20 08:11 PM The silane we ordered here is a liquid, I don't think we have any licenses or inspections other than a business license 21-Jan-20 08:21 PM Address is in an industrial park though 21-Jan-20 09:18 PM Silane is one of those things that CA's jurisdictions are way to aware of. Too many unpleasant incidents with fabs and shops in the 1970s, which is part of why most of that got offshored in the 1980s & 90s because the fire/hazmat requirements were getting unpleasant. Any goodwill Silicon Valley had with the local fire departments was looooong f'n gone with too many dead firefighters. 21-Jan-20 09:18 PM So, if you're wondering why odd delays crop up for toxic/flammable/pyrophoric items its that they give people pause as they check their own liability in shipping. 21-Jan-20 09:49 PM Huh, interesting...I knew stuff like emissions and waste treatment was a reason for offshoring, didn't think about storage or day to day operations processing 21-Jan-20 09:50 PM accidents are a lot cheaper offshore too 21-Jan-20 09:54 PM Silane is nasty nasty stuff. But our government has made a ridiculous stand here in California that solar can fix everything (which it really cant unless we have lots of hazardous batteries all over, or they let us build more pump charge hydro which they never will cause of the environmental loby here in CA) you have to get those cheap Chinese solar panels, well and there you go low and behold toxic firey messes will occur in unregulated mainland China fabs. 21-Jan-20 09:54 PM Oh. And the glass gods are not with me today. Was going to test the emission of some unknown origin cathodes. Of the 4 I made, none of them made it. 2 fatal cracks during sealing. One cracked on the pump, and the fourth cracked right after tip off. Some days I just can’t do anything right. 21-Jan-20 10:08 PM Silane, arsine, and phosgene are the three main culprits in semiconductor fab nightmares for firefighters. Those who survived the 1970s and early 80s made absolutely certain to tell everyone else. The first hazmat regs and CHEMTRAK came online because the fire departments had informed several major companies that they would absolutely not be responding to their fabs until they got their act together to the fire departments' satisfaction. National Semiconductor caved first. Good luck with tomorrow's glass blowing, @Charles. 21-Jan-20 11:25 PM Hmm, I heard the reason Intel and the likes didn't get into solar manufacture was due to the wafers being so large that long distance transport of finished products was quite difficult. It's strange then that we have seemingly succumbed to cheap chinese panels... Does that imply that non-cheap panels are the "buy local" option? Or that they're also higher quality in terms of power output somehow, as in the cheap panels are physically stronger with the tradeoff of power capacity? 22-Jan-20 12:22 AM @Charles there is active development on alternative energy storage as well though. Things like flywheels and pumping water to higher elevation etc. The flywheel stuff is pretty darn neat, too. Vacuum sealed, maglev and have to be oriented according to location to counter Coriolis and the like. 22-Jan-20 12:22 AM I think the primary drive for those companies is the whole peak-usage sort of thing with conventional power plants, but energy storage is energy storage 22-Jan-20 12:34 AM I think his point was that the environmental protection regulations/lobby have gone so far in CA that very few realistic "green energy" plans gain traction 22-Jan-20 12:34 AM instead we end up with big solar bird cookers 22-Jan-20 12:34 AM also we export most of the environmental cost of our "green" energy mandates in california to China heh 22-Jan-20 12:37 AM ah, gotcha. Barely read it all TBH. I like to argue. 22-Jan-20 12:37 AM btw got a buncha those connectors coming soon. If you want me to make you up a "proper" cable lemme know your pump/controller combo 22-Jan-20 06:58 AM We have some of the best hydro pump charge storage systems in the world here in California, but we cannot built any more due to bad regulation and general public misconceptions about how water works in this state. It has made me angry so many times how our state legislature will use junk science, human emotion, and extreme anti human development group talking points to stop proper environmental management progress. All to maintain their power base of uneducated idiots. 22-Jan-20 06:58 AM They view water as a finite resource. What a fallacy that is. I have been in the water filtration and distribution business in agriculture my entire working life and With the exception of over drafting from ground water supplies, which is a real issue, limited availability of water is only a failing of humans to put the work Into developing infrastructure. But Infrastructure development talk does not get you votes. I truly hate this state and wish I could leave just so I would not have to see these idiotic policies in action every day. 22-Jan-20 08:03 AM Couple that with the state of our bridges and interstates too. We need to raise Eisenhower from the dead and let him have another go at things lol. 22-Jan-20 08:03 AM When the singularity comes maybe we can buy another few decades of labor where everyone is a tradesman 22-Jan-20 09:42 AM @Charles I love California but things are getting really bad the last few years. Very few people I know do not have plans to leave. I am pretty close to tapping out too but still have to get things in line to make it happen. Sorry you are feeling the way you do about California but I really cannot blame you at all. Any states you are looking at? Arizona is a strong contender for me but they are starting to have some of the political problems California does (probably due to Californians moving there!). 22-Jan-20 09:48 AM Exactly. We are destroying other places. South Texas has become kind of weird from all the Californians moving in and north/central Texas is not to friendly to us anymore. Last trip out there I got a lot of stares and snide comments. 22-Jan-20 09:52 AM yeah my neighbors just moved to the DFW area in Texas and they got new TX plates before they even went to their new house haha 22-Jan-20 10:07 AM Prejudice against Californians is high in Portland OR too, or has been in the past... Stuff like graffiti against Californians on real estate signs, and yeah stuff like a Cali license plate getting your car messed with 22-Jan-20 10:07 AM Exodus is definitely pushing housing market to get more expensive in other places, all over 22-Jan-20 10:10 AM that is funny because it is usually more conservative areas that are unhappy about Californians in my experience (because they start voting for California-esque policies in states not yet destroyed by them) 22-Jan-20 10:10 AM never heard about that sorta thing happening in Portland but maybe that is more a population/financial thing than politics 22-Jan-20 10:21 AM https://www.oregonlive.com/front-porch/2015/09/no_californians_stickers_being.html 22-Jan-20 10:21 AM Yeah I think it was probably income related 22-Jan-20 10:50 AM Also, quick question @Charles 22-Jan-20 10:50 AM Is it feasible to join borosilicate tubes to soda lime bulbs? 22-Jan-20 10:50 AM I was thinking about trying to refill nixies for a unique product 22-Jan-20 10:50 AM (to make money to make actual nixies lol) 22-Jan-20 10:53 AM Not is any permanent way directly. Could be done with housekeeper seal but it’s gonna be super tricky. I would recommend adding on a new length of soft glass to use as a new exhaust port then using compression type seals, perhaps O rings for your processing, then pinch off like when it was done as new. 22-Jan-20 10:53 AM Right, soda lime to soda lime only 22-Jan-20 10:53 AM I guess I'll need to anneal it 22-Jan-20 10:54 AM Correct. 22-Jan-20 10:54 AM What temps and profile do you anneal it at? 22-Jan-20 10:54 AM But remember the smaller the tube the less stress and more foregining it will be 22-Jan-20 10:54 AM Something like 400C to 25C over the course of 10 hours? 22-Jan-20 10:54 AM Depends 22-Jan-20 10:54 AM What size tubes are we talking about and are the exhaust tips at the opposite end of the metal pin seals 22-Jan-20 10:55 AM Most cheap soviet nixies have the stem right next to the pins 22-Jan-20 10:55 AM If you can avoid heating the end with the metal pin seals you are in much better shape 22-Jan-20 10:56 AM Usually 20-30mm diameter, sometimes not tubular(IN-12s) 22-Jan-20 10:56 AM With maybe a 5 or 7mm OD exhaust tube 22-Jan-20 10:56 AM Oh.. that’s really tough. I would try to add the exhaust tube somewhere else. 22-Jan-20 10:56 AM Anything I could do to avoid heating the glass to metal seals. Even with proper annealing it’s kind of tricky 22-Jan-20 10:56 AM Unless you have bucket loads of them to practice with to develop some accurate timing methods. 22-Jan-20 10:58 AM There are some nixies with top evacuation, would that be a lot easier? 22-Jan-20 10:58 AM Yes. Some side view ones. 22-Jan-20 10:58 AM How far are you from JJ electronics? Could you simply buy some stems and bulbs from them and just build some new ones ground up? 22-Jan-20 11:00 AM Belarus is pretty far from the other side of the world 22-Jan-20 11:00 AM does jj electronics manufacture stems for sale? 22-Jan-20 11:03 AM Tim sells stem cells down by the STEM door 22-Jan-20 11:06 AM https://www.youtube.com/watch?v=oFJ1hMNmE3A 22-Jan-20 11:06 AM There's these guys 22-Jan-20 11:06 AM Looks like they succeeded in re-sealing to an IN-18, but then vanished 22-Jan-20 01:55 PM 15% coupon on ePay! PLUGGEDIN expires midnight PST 22-Jan-20 01:55 PM Been waiting for this! 22-Jan-20 01:55 PM Checks account balance 22-Jan-20 01:55 PM Nevermind 22-Jan-20 01:57 PM Also 5% epay bucks now too 22-Jan-20 01:57 PM so yea 22-Jan-20 01:57 PM great time 22-Jan-20 01:58 PM https://www.ebay.com/itm/Inficon-BPG400-353-500-Vacuum-Gauge-with-Sensor-BPG400/333387541361 22-Jan-20 01:58 PM Well maybe I will get one thing afterall 22-Jan-20 02:00 PM https://i.spirit.re/acQsi.png 22-Jan-20 02:00 PM pfft 22-Jan-20 02:00 PM 25 seconds ago 22-Jan-20 02:01 PM I don't need it badly enough to buy it immediately 22-Jan-20 02:01 PM No harm in waiting a few hours before giving in to my inner hoarder 22-Jan-20 02:01 PM Wait a sec... @Conmega 22-Jan-20 02:01 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-9B449.png 22-Jan-20 02:07 PM For me it said on over 50 bucks or something 22-Jan-20 02:07 PM weird 22-Jan-20 02:07 PM Now I'm confused 22-Jan-20 02:07 PM Yea they popped it up on everything I opened in random categories 22-Jan-20 02:07 PM first time I have seen those tactics sorry 22-Jan-20 02:12 PM Ah that's fine... I still consider a tested working full range gauge for $98 delivered a pretty good deal 22-Jan-20 02:15 PM still 5% ebay bucks right now 22-Jan-20 02:21 PM Now I can replace the awful pirani gauge on my SEM with this 22-Jan-20 02:29 PM Joined the server. 22-Jan-20 03:05 PM How's that compare to the mks901p, which is a micro pirani? 22-Jan-20 03:06 PM the 901p can't do UHV or lower HV 22-Jan-20 03:06 PM I have an IGM400 for that part of the high vacuum 22-Jan-20 03:06 PM and a PPT-100 that I got before I got the 901p 22-Jan-20 03:07 PM This is for the BPG400 22-Jan-20 03:07 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-D97AF.png 22-Jan-20 03:07 PM In reality the lower range is limited by the KF flange 22-Jan-20 03:07 PM But, like the 901p, it talks RS232 and also gives a 0-10V analog output 22-Jan-20 03:07 PM I also like it because the gauge body can be quickly unplugged, so if I'm doing any high voltage pulsed stuff I can be sure I won't kill the gauge accidentally 23-Jan-20 08:50 AM Ah, nice, so no special controller needed 23-Jan-20 08:50 AM The name Balzers is just, a weird name to me 23-Jan-20 02:59 PM Did you get that last remaining gauge from the listing? 23-Jan-20 03:02 PM your offer got accepted 23-Jan-20 03:03 PM I know, but someone else got the last gauge, that's not me 23-Jan-20 03:03 PM wasn't there only 1? 23-Jan-20 03:03 PM No, there were two remaining 23-Jan-20 04:06 PM Joined the server. 23-Jan-20 04:06 PM Anyone got any good ideas for some old diffusion pumps ? 23-Jan-20 04:06 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-1194E.jpg 23-Jan-20 05:40 PM That looks like a new diffusion pump 23-Jan-20 05:40 PM That’s an old diffusion pump 23-Jan-20 05:40 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-C0284.jpg 23-Jan-20 05:40 PM Yours looks clean and serviceable. Has it got oil in it? 23-Jan-20 05:42 PM not always... I mean I have seen some really old diff pumps not look that abused... depends on how its been stored and maintained 23-Jan-20 05:42 PM also the heaters can fail and the pump can still look OK, or the inside can be filthy and the outside can look ok 23-Jan-20 05:42 PM there is a lot not determined by outside looks 23-Jan-20 05:43 PM True 23-Jan-20 05:43 PM But if it’s stored connected to a closed vacuum system that’s probably a good sign 23-Jan-20 05:43 PM so long as it wasn't run low on oil and or contaminated/etc 23-Jan-20 05:43 PM but way better than being stored open like that yes 23-Jan-20 05:44 PM I would start by cleaning external dust, measuring heater resistance and inspecting inside 23-Jan-20 06:20 PM I don’t know what went into decommissioning it. It’s probably 20-30 years old and been out of service for around 15? 23-Jan-20 06:20 PM I’m a grad student, this is one of the things I put in the “don’t throw away yet” pile and have stored in a closet 23-Jan-20 06:21 PM Good ideas for old diff pumps are pretty muxh the same as ideas for new pumps 23-Jan-20 06:22 PM No because we’re dry now 23-Jan-20 06:22 PM That one looks quite large 23-Jan-20 06:22 PM Dry now? 23-Jan-20 06:22 PM Like, alcohol free? 23-Jan-20 06:22 PM Yeah, all systems are turbos and scrolls or dry screws 23-Jan-20 06:23 PM Oh 23-Jan-20 06:23 PM The rotary vane and diffusion pumps are banished 23-Jan-20 06:23 PM I still dont see how that changes old vs new 23-Jan-20 06:24 PM Ok, by “old” I mean phased out of the lab 23-Jan-20 06:25 PM Build a plasma etcher 23-Jan-20 06:28 PM Ok in the closet it stays 23-Jan-20 06:28 PM There’s two more and an Edwards 80 23-Jan-20 06:28 PM Give me an idea an undergrad could do in a summer 23-Jan-20 07:08 PM Sell them? 23-Jan-20 07:19 PM This is academia 23-Jan-20 07:19 PM We don’t sell things, we hoard them until they’re not wanted by ANYONE,. 23-Jan-20 07:19 PM Or give them to undergrads. 23-Jan-20 07:27 PM most amusing use for a big old diff pump i have heard of is a big solvent cleaner 23-Jan-20 07:43 PM how would a diffusion pump perform with different food oils? 23-Jan-20 07:44 PM do not think any of those are really suitable for vacuum conditions besides maybe food grade mineral oil? 23-Jan-20 07:44 PM so it probably would not perform at all...at least with my understanding of how they work 23-Jan-20 07:51 PM hmm raffinated soy oil? 23-Jan-20 07:51 PM I mean idmb could test it 23-Jan-20 07:51 PM no? 23-Jan-20 07:51 PM if it doesn't work make some eggs benedict in it? 23-Jan-20 08:02 PM might just be a really frustrating mess but how others spend their time is totally their choice heh 23-Jan-20 08:02 PM the proper silicone oils are not that expensive anyway unless you need something really extreme (again as far as i know) 23-Jan-20 08:05 PM 705 Extreeeme 23-Jan-20 08:05 PM with a racing design 23-Jan-20 08:40 PM KFC uses pressure fryers for their chicken... Maybe because vacuum frying was just too hard. Can't know until you try ;) 23-Jan-20 08:45 PM Can't know until you fry FTFY 23-Jan-20 09:04 PM if it made a mess I could just wrap the ports on the chamber with tinfoil and hide it back in the closet, nobody would know 23-Jan-20 10:21 PM :)) 24-Jan-20 02:25 AM @idmb an undergrad should easily be able to make a big plasma asher, RIE, or deposition system in a summer 24-Jan-20 07:50 AM Ok now to find a use for one of those 24-Jan-20 08:42 AM give him some undergrads 24-Jan-20 03:38 PM What’s the most consecutive flanges you guys have seen? 24-Jan-20 03:38 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-D1B3C.jpg 24-Jan-20 03:56 PM i considered trying to connect up an equivalently flangeful stack-up of my turbo -> throttle valve -> gate valve -> chamber at one point, but worried about the compressive forces needed to bite through all those gaskets 24-Jan-20 03:56 PM good to know it's at least somewhat feasible 24-Jan-20 03:58 PM from what I know you compress conflat until the SS flanges touch... So as soon as they do you'll start crushing the next weakest copper... So yea, just keep tightening until you can't anymore. 24-Jan-20 03:58 PM That is unless your trying to get multiple uses out of your copper... which is unrecommended anyway 24-Jan-20 04:01 PM i am a terrible cheapskate and also am aware of some vague bolt torque recommendations for CF 24-Jan-20 04:01 PM which, if followed, actually end up leaving you with some visible copper between the flanges 24-Jan-20 04:01 PM i've reused a few gaskets on my system on its last reinstall that were only bit down about that far; gave those ones an anneal, and then cranked them down 'till they touched. not recommended, but seems to work.. 24-Jan-20 04:01 PM (i am also a stupid hobbyist doing nothing of any mission-critical nature) 24-Jan-20 04:03 PM Theoretically your gaskets should always deform where they are the weakest if all stacked together, that would be the one that's biting in the shallowest 24-Jan-20 04:03 PM Using a crisscross pattern, tighten the bolts 1/4 to 1/2 turn, (1/16 of a turn for annealed gaskets) one at a time to the appropriate torque value, or until the flange faces are "metal to metal." 24-Jan-20 04:03 PM https://www.lesker.com/newweb/flanges/flanges_technicalnotes_conflat_1.cfm 24-Jan-20 04:04 PM oh, well, alright 24-Jan-20 04:04 PM So you can do either... 24-Jan-20 04:04 PM i guess KJL knows what they're talking about 24-Jan-20 04:04 PM Yea I've seen it said both ways from reputable companies 24-Jan-20 04:05 PM Lol 24-Jan-20 04:05 PM For stacked flanges you should go in multiple steps approaching the torque value 24-Jan-20 04:05 PM KJL 24-Jan-20 04:05 PM I love KJL but they’re not that expert 24-Jan-20 04:05 PM They let me make mistakes 24-Jan-20 04:05 PM Anyways triple flange is super common 24-Jan-20 04:05 PM Used in most molecular jet setups and they sell double/sided blanks anyways 24-Jan-20 06:59 PM Happy chinese new year 24-Jan-20 06:59 PM I hope all your vacuum dreams comes true 24-Jan-20 08:34 PM My dream: no more unexpected power cuts 25-Jan-20 04:33 PM any suggested oil mist eliminator or similar thing to put on rotary pump exhaust? 25-Jan-20 04:33 PM oh i guess i might as well put foreline trap on it 25-Jan-20 04:34 PM There are pre-built exhaust mist traps 25-Jan-20 04:34 PM Aren't you using the foreline trap on... the foreline? 25-Jan-20 04:36 PM i can but don't need to on the current project, this was more of reducing a nuisance 25-Jan-20 04:36 PM only one pump atm 25-Jan-20 04:36 PM A simple solution is just using a toilet paper roll with a cardboard core 25-Jan-20 04:36 PM Pull the cardboard core out 25-Jan-20 04:36 PM ahh 25-Jan-20 10:52 PM https://sci-hub.tw/10.1109/TPS.2019.2942997 25-Jan-20 10:52 PM this seems like BS but its from IEEE and they are not usually the kind to publish that sorta thing 25-Jan-20 10:52 PM also the author is attached to all the weird Navy patents 25-Jan-20 10:52 PM would love to hear some perspectives on it from people here 26-Jan-20 12:20 AM welcome! 26-Jan-20 12:29 AM not welcome! 26-Jan-20 12:30 AM @GigaSquirrel administrative actions please 26-Jan-20 12:31 AM shhh you saw nothing 26-Jan-20 03:07 AM <__ice9#6039> @Deleted User yes I am quite familiar with homemadeliquidnitrogen.com 26-Jan-20 03:07 AM hm? 26-Jan-20 03:08 AM <__ice9#6039> Following up on your comment in #resources 26-Jan-20 03:08 AM <__ice9#6039> Regarding N2 purification by PSA 26-Jan-20 03:08 AM that was @LRM 26-Jan-20 03:08 AM <__ice9#6039> Oops 26-Jan-20 03:08 AM <__ice9#6039> Anyway pre-processing is possible with just a reverse osmosis membrane, which somewhat diminishes the necessary amount of carbon molecular sieve for PSA-- although the RO membrane needs to be kept scrupulously dry for it to work correctly. 26-Jan-20 03:08 AM <__ice9#6039> So zeolite 3A is needed as a desiccant prior to the membrane 26-Jan-20 07:17 AM hey guys 26-Jan-20 07:17 AM what's your fav UHV/XHV Al? still 6061? 26-Jan-20 07:43 AM @__ice9 do you also know how to make water purifiers with molecular sieves? I heard about a (mostly?) passive method for desert dwellers years ago, which used sun shade and valves to cyclically absorb and drive off adsorbed water 26-Jan-20 10:10 AM @LRM That paper is just full of qualitative and unsubstantiated assertions, paired with a lot of trivial babble and no meaningful performance analysis 26-Jan-20 10:10 AM I highly doubt that he can use shear flow stabalization to suppress instabilities in the plasma, since in a rotating plasma column there's so many other sources of nonlinear forces due to the Lorentz force that radially compresses the plasma 26-Jan-20 10:10 AM I also have problem visualizing how the "negative potential well" is generated. More detailed schematics than what was shown will definetely be needed to even begin to evaluate this device 26-Jan-20 10:10 AM The fact that he filled his paper with speculative solutions to practical concerns before even knowing the physics in his concept would work at all just screams BS 26-Jan-20 10:30 AM The author also submitted this patent... 26-Jan-20 10:30 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/ProQuestDocuments-2020-01-26-98CD9.pdf 26-Jan-20 10:30 AM The most amount of meaningless science babble I've seen stuffed into a patent so far 26-Jan-20 10:36 AM lel 26-Jan-20 10:38 AM lol 26-Jan-20 10:38 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-82A03.png 26-Jan-20 10:38 AM the title is enough to detect the BS 26-Jan-20 10:38 AM But, this also makes me sad 26-Jan-20 10:38 AM I had great respect for the IEEE Division of Plasma Physics 26-Jan-20 10:39 AM people have strange hobbys 26-Jan-20 10:39 AM The fact that such obvious BS got through is just so depressing 26-Jan-20 10:39 AM no respect for ieee 26-Jan-20 10:41 AM There's certainly a lot of people who knows their stuff in IEEE, sadly a lot of them mostly keep it to themselves or within very closed circles 26-Jan-20 10:41 AM @Mason_Yu thats what I thought. I wonder if IEEE was pressured to publish it or something 26-Jan-20 10:41 AM I don't know, their editorial team must up their game 26-Jan-20 10:41 AM thats also true for the whole universe 26-Jan-20 10:42 AM might be similar to what happened with the patent office when it was pushed to grant the super weird patents? 26-Jan-20 10:42 AM only reason i can think of is we (the USA) are trying to get someone to spend lots and lots of money researching technobabble 26-Jan-20 10:43 AM they're bureaucrats! 26-Jan-20 10:44 AM Well perhaps someone at the Navy was convinced by this one guy and submitted a patent without knowing the validity any of the technical details 26-Jan-20 10:44 AM https://www.linkedin.com/in/james-sheehy-28437a8 26-Jan-20 10:44 AM Probably this guy 26-Jan-20 10:45 AM in the navy ... 26-Jan-20 10:45 AM https://youtu.be/nmGuy0jievs 26-Jan-20 10:47 AM i am just grasping at straws for an explanation that allows me not to lose all respect for IEEE haha 26-Jan-20 10:48 AM :)) 26-Jan-20 10:49 AM Hey I've got a friend who's at Patuxent river AFB 26-Jan-20 10:49 AM He might be able to get in touch with this guy, though I doubt Salvatore is actually involved in any serious stuff that happens over there 26-Jan-20 10:51 AM would getting in touch with someone publishing technobabble really be worth anyone's time? 26-Jan-20 10:51 AM it would be very cool if there was a shred of truth to it but everything seems way too far fetched 26-Jan-20 10:52 AM I'm just interested to know what enabled this guy to get his BS published and patented. Plus I think it'll be fun for my friend lol 26-Jan-20 10:52 AM He's interested in colliding beam fusion by the way 26-Jan-20 10:52 AM Oh he's in this server! 26-Jan-20 10:53 AM moin! 26-Jan-20 10:58 AM morning 26-Jan-20 12:36 PM Is that paper related to the polywell fusion stuff? 26-Jan-20 12:42 PM As far as I can tell, no 26-Jan-20 12:45 PM it is related to some patents a researcher associated with the navy got after an intervention by someone in his appeal to the patent office...all very questionable stuff 26-Jan-20 12:45 PM He sites some qualitative results from Polywell work but the concept itself is all unrelated 26-Jan-20 12:46 PM A question to vacuum and non vacuum people like @Charles 26-Jan-20 12:46 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/HTB1wGxcm26TBKNjSZJiq6zKVFXaO-9B178.png 26-Jan-20 12:46 PM Would these guys work for wrangling the low pressure gases for vacuum/nixie stuff? 26-Jan-20 12:46 PM if I bolted one end of that to a KF fitting and plugged that into a tee 26-Jan-20 12:46 PM my concern here is leaks when it's under high vacuum 26-Jan-20 12:48 PM Yeah, you'd need a bakable precision leak valve to go directly to UHV 26-Jan-20 12:48 PM they sure do 26-Jan-20 12:48 PM it won't be UHV, but I'm expecting to bake the nixies down to around -5 or -6, and one of these valves will have to interface directly to that 26-Jan-20 12:48 PM they look like swagelok clones 26-Jan-20 12:49 PM Yes. As a matter of fact we used Nupro B-4 style valves on all of our gas fill rigs. 26-Jan-20 12:49 PM great, I can order these locally and cheap 26-Jan-20 12:49 PM from a wholly unexpected source - beer brewer/distillery stores 26-Jan-20 12:49 PM Awesome. Just make sure they are the bellows version and not the needle version 26-Jan-20 12:49 PM these are all needles 26-Jan-20 12:49 PM probably should've mentioned that beforehand 26-Jan-20 12:50 PM Oh.. the life expectancy will be lower then. 26-Jan-20 12:50 PM is that the only issue? 26-Jan-20 12:50 PM I don't really care about their lifespan, they're $8-10 a piece and I will be filling maybe a nixie and a half in my lifetime 26-Jan-20 12:50 PM Still should be good for gas dosing just make sure you are not evacuating a large volume or the transmittance will be slow as a wet week 26-Jan-20 12:50 PM I have got a Swagelok needle valve before a leak valve, and I found I cannot get below 10^-3 with the leak valve open and the needle valve closed 26-Jan-20 12:51 PM so it's probably best to get these for all the positive pressure things and a proper leak metering valve at the business end? 26-Jan-20 12:51 PM Now my rig doesn't have a lot of pumping speed but I'm pretty sure the needle valve leaks quite a bit 26-Jan-20 12:51 PM Yeah 26-Jan-20 12:51 PM Correct 26-Jan-20 12:52 PM does it have to be a bellows type, or just any "flow metering valve"? 26-Jan-20 12:52 PM Well flow metering is always a kind of needle but the on off gass admittance should be bellows for speed and ease of use 26-Jan-20 12:54 PM right, so it's the seal that drives the needle 26-Jan-20 12:57 PM Sorry. Gotta hit the road. I will write up something later on going over how we did the gas filling. 26-Jan-20 12:57 PM Alright, thanks 26-Jan-20 02:58 PM Joined the server. 26-Jan-20 03:02 PM I'm gonna say spam bot 26-Jan-20 03:02 PM Tho I'd be happy to be proven otherwhise 26-Jan-20 03:02 PM Wonder if I can crash it by PMing it garbage 26-Jan-20 03:10 PM @Deleted User I've found the swagelok needle valves very inconsistent with vacuum 26-Jan-20 03:10 PM some from the factory seal fine, some don't 26-Jan-20 03:10 PM the bellows-sealed ones can be very badly damaged from over-tightening and IDK if I would consider used ones 26-Jan-20 03:15 PM http://tinyurl.com/sgnns5j - Dissertations - Courseworks - Essays! Premium Writing Service for beautiful ladies and handsome gentlemen! 26-Jan-20 03:15 PM Knew it @GigaSquirrel 26-Jan-20 03:15 PM @idmb yeah that's what I'm thinking 26-Jan-20 03:15 PM bellows are fragile 26-Jan-20 03:15 PM but they should seal a lot better 26-Jan-20 03:20 PM yeah well the regular swagelok ones are regularly connected as vent valves on UHV chambers 26-Jan-20 03:20 PM and even using the needle valves for rough vacuum is sketchy 26-Jan-20 03:21 PM swagelok is either ball or needle though 26-Jan-20 03:21 PM ? 26-Jan-20 03:21 PM "and even using the needle valves for rough vacuum is sketchy" 26-Jan-20 03:23 PM https://www.swagelok.com/en/catalog/Product/Detail?part=SS-4H 26-Jan-20 03:23 PM the leaking isn't through the gasket seal 26-Jan-20 03:23 PM it's an O-ring from the shaft 26-Jan-20 03:23 PM positive pressure seals the regular needle valves by pushing up against an O-ring 26-Jan-20 03:23 PM but if it's under vacuum there's a leak 26-Jan-20 03:23 PM looking at diagrams that's what I figured, at least. And experimentally testing by pumping the front and back of each type agreed with that. 26-Jan-20 03:23 PM (new ones) 26-Jan-20 03:25 PM Testing Helium leak testing according to SCS-00020 26-Jan-20 03:25 PM interesting 26-Jan-20 03:25 PM I found this valve pretty cheap 26-Jan-20 03:25 PM http://catalog.hoke.com/item/metering-valves/milli-mite-1300-series/1315g6ymm 26-Jan-20 03:25 PM It should work as a barrier between the high vacuum and gas systems, right? 26-Jan-20 03:25 PM the Gyrolok seal seems a bit more pre-compressed than the others 26-Jan-20 03:27 PM eugh, people in my lab were mixing all the brands of compression fittings 26-Jan-20 03:27 PM nothing worked properly 26-Jan-20 03:28 PM VCR is expensive to get a full set for 26-Jan-20 03:28 PM so I'm stuck with either NPT or straight imperial threads 26-Jan-20 03:28 PM VCR is only worth it if you want to undo and redo the connection a lot 26-Jan-20 03:29 PM maybe it makes sense to just get another high vacuum KF valve and put it between the gas and vacuum systems 26-Jan-20 03:29 PM isn't that quite pricey? 26-Jan-20 03:29 PM used of course 26-Jan-20 03:30 PM how much? 26-Jan-20 03:30 PM very used! :P 26-Jan-20 03:30 PM there's cheap-ish kf16 valves on ebay 26-Jan-20 03:30 PM $10-50 including shipping depending on luck 26-Jan-20 03:30 PM and then I'd probably machine a KF16 to NPT/imperial adapter out of aluminium so it can be slightly overtightened and sealed well 26-Jan-20 03:33 PM just buy a proper leak valve 26-Jan-20 03:33 PM they're only $1750 or so 26-Jan-20 03:34 PM said the person that doesn't touch budgets hehe 26-Jan-20 03:35 PM I broke one my first month 26-Jan-20 03:35 PM accidentally sent 2000 PSI to the back of it 26-Jan-20 03:35 PM shattered the sapphire 26-Jan-20 03:35 PM oops 26-Jan-20 03:35 PM I got given the budget for my project after I had already spent 70% of it 26-Jan-20 03:36 PM https://www.ebay.com/itm/Granville-Phillips-Series-203-Variable-Leak-Valve-Bakeable/124016511566 26-Jan-20 03:37 PM they forgot the 'r' in Bakeable 26-Jan-20 03:38 PM https://www.ebay.com/itm/VARIAN-9515106-VARIABLE-LEAK-VALVE-2-75-FLANGE/274185760076?hash=item3fd6bead4c:g:QKUAAOSw6GJeEjNv 26-Jan-20 03:38 PM that's what we have 26-Jan-20 03:39 PM I wonder how they work 26-Jan-20 03:39 PM Two optically flat pieces of sapphire pressed against each other 26-Jan-20 03:39 PM With a lever that adjust the force 26-Jan-20 03:39 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/6HX6HzWGXz7Gdq2dAAAAAElFTkSuQmCC-AF4ED.png 26-Jan-20 03:40 PM https://www.agilent.com/cs/library/usermanuals/public/Variable%20leak%20valve.pdf 26-Jan-20 03:40 PM they have the documents + repair manual + replacement parts available 26-Jan-20 03:40 PM Yeah I have one of those as well 26-Jan-20 03:40 PM we use ours for liquids 26-Jan-20 03:40 PM it takes a while to stabilize 26-Jan-20 03:40 PM even if we keep the line + reservoir at a very stable temperature 26-Jan-20 03:41 PM these won't work for me since I do need quite a bit of volume 26-Jan-20 03:41 PM filling up a good 50-60ml of space to 20-80 torr 26-Jan-20 03:41 PM ah 26-Jan-20 03:41 PM yeah ours are from some weird electron gun experiment 26-Jan-20 03:42 PM They will leak pretty fast if you just open it completely 26-Jan-20 03:42 PM not on the ~1 torr scale 26-Jan-20 03:42 PM you can try it yourself, put a pressure gauge on the upstream part and try pumping the line by opening the valve 26-Jan-20 03:42 PM it takes forever 26-Jan-20 03:42 PM have you ever seen a pulsed valve? for molecular jets? 26-Jan-20 03:45 PM piezo I presume? 26-Jan-20 03:45 PM no 26-Jan-20 03:45 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screen_Shot_2020-01-26_at_3.45.08_PM-B933A.png 26-Jan-20 03:45 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screen_Shot_2020-01-26_at_3.45.14_PM-30C17.png 26-Jan-20 03:45 PM these beauties 26-Jan-20 03:45 PM can do ~50us pulses of gas at 1KHz 26-Jan-20 03:46 PM interesting 26-Jan-20 03:46 PM the test procedure is to put alcohol on the tip out of vacuum 26-Jan-20 03:46 PM and then run it 26-Jan-20 03:46 PM and if you run it at like 10Hz 26-Jan-20 03:46 PM it pulses a pretty little fountain 26-Jan-20 03:46 PM anyways I was using one of those as a leak valve on my newer system while I wait for my new leak valve to arrive 26-Jan-20 03:46 PM they're ~10k with a 2 year lead time IIRC 26-Jan-20 03:46 PM handmade in israel or something 26-Jan-20 03:49 PM I'm looking if FR-4 material from PCB is vacuum compatible 26-Jan-20 03:49 PM generally yes, but only high quality 26-Jan-20 03:49 PM and no solder mask, silkscreen, glue, or anything 26-Jan-20 03:50 PM and it depends on the vacuum you wish to achieve 26-Jan-20 03:50 PM (unless it wrecks itself ?) 26-Jan-20 03:53 PM What about tin solder? 26-Jan-20 03:53 PM Lead-tin solder 26-Jan-20 03:53 PM that will work 26-Jan-20 03:53 PM remember to clean the flux off 26-Jan-20 03:53 PM Lead doesnt outgass according to NASA database 26-Jan-20 03:54 PM for highest high vacuum stuff it's ceramic PCBs and wire bonding 26-Jan-20 03:54 PM Ceramic pcb? Interesting 26-Jan-20 03:55 PM common in RF stuff and hybrid modules 26-Jan-20 03:55 PM except you'd probably want a sputtered/evaporated copper on it, not glued on 26-Jan-20 03:55 PM Machinable ceramic? 26-Jan-20 03:55 PM "machinable" ceramic 26-Jan-20 03:55 PM you have to have quotes there 26-Jan-20 03:55 PM always 26-Jan-20 03:56 PM Lot of coolant I suppose 26-Jan-20 03:56 PM When machining 26-Jan-20 03:56 PM I had some HV electrode holders made out of Macor 26-Jan-20 03:56 PM and watched them make them 26-Jan-20 03:56 PM did not look fun. 26-Jan-20 04:05 PM @chucrut What do you want to put in vacuum? 26-Jan-20 04:07 PM I want to put a circuit inside a SEM 26-Jan-20 04:07 PM I wish aliexpress have custom ceramic pieces service 26-Jan-20 04:07 PM @GigaSquirrel take it down 26-Jan-20 04:07 PM Found a bot 26-Jan-20 04:07 PM @Unknown 26-Jan-20 04:07 PM Nelly Dafoe Herbert 26-Jan-20 04:23 PM But why inside? 26-Jan-20 06:11 PM @chucrut you could also pot the pcb in torr seal/hysol 1c... Or if not pot it, paint a layer on as much area as you can 26-Jan-20 06:48 PM When it comes to machining ceramic, there is one septuagenarian that comes to mind. NASA Ames sort of had a policy that if you think something can be machined, you probably hadn’t asked Mr. Wallace yet. 26-Jan-20 07:06 PM Really? Our machine shop answers every single question with "well we can do it, but..." 26-Jan-20 07:09 PM Joined the server. 26-Jan-20 07:09 PM oh 26-Jan-20 07:09 PM k 26-Jan-20 07:09 PM what did that? 26-Jan-20 07:09 PM Welcome! 26-Jan-20 07:09 PM So my old account got falsely banned, with a mountain of evidence against it(from my end) 26-Jan-20 07:09 PM I have to rebuild everything I had on a new account :( 26-Jan-20 07:10 PM oh no, did that happen irl? 26-Jan-20 07:10 PM back to primary school? 26-Jan-20 07:10 PM irl what? 26-Jan-20 07:10 PM discord just banned my old account for something I didn't do 26-Jan-20 07:10 PM allegedly 26-Jan-20 07:10 PM mountain of evidence here 26-Jan-20 07:11 PM One of the linus tech tips staff had their WoW account banned for six months, and can't get in touch with tech support to figure out why 26-Jan-20 07:11 PM an angry person launched a series of DDoS and bruteforce attacks on my server, punched a community I run pretty hard 26-Jan-20 07:11 PM despite callouts on a tech channel with 10m subs 26-Jan-20 07:11 PM jeez 26-Jan-20 07:11 PM I looked him up(publicly!), posted his(public!!!) info, he allegedly reported it, I got banned 26-Jan-20 07:11 PM someone who doesn't believe in laser goggles? 26-Jan-20 07:12 PM no, a child cheating in a game 26-Jan-20 07:12 PM the rest should go in #off-topic-thats-sometimes-on-topic if someone wants to talk about it, but I'd rather not 26-Jan-20 07:12 PM Well anyways welcome back 26-Jan-20 07:13 PM thanks 26-Jan-20 07:13 PM you didn't go with a name like Esprit 26-Jan-20 07:14 PM meh, it doesn't matter 26-Jan-20 07:14 PM I just hope they don't ban this one for absolutely no reason again 26-Jan-20 07:32 PM https://www.ebay.com/itm/Varian-951-5014-manual-high-vacuum-angle-valve-conflat-1-33/113741461918 26-Jan-20 07:32 PM A Swagelok/Nupro needle valve or metering valve followed by a tiny angle valve like this could be a nice and cheap solution? @Spirit 26-Jan-20 07:33 PM not particularly cheap but yeah 26-Jan-20 07:33 PM Oh now there's two Sprits to tag in the server 26-Jan-20 07:33 PM someone can rename the old Spirit to something like notspirit 26-Jan-20 08:55 PM almost finished building this sputter coater... and forgot to get ptfe tape for the baseplate threads. 26-Jan-20 08:55 PM such a shame 26-Jan-20 10:07 PM Joined the server. 26-Jan-20 10:35 PM could i use silica in between a rotary vane pump and a chamber with some minor wet objects to trap the water vapor? 26-Jan-20 11:15 PM i do not think that silica absorbs fast enough to be used for that...but maybe you could pump down and leave the silica in the chamber sorta like they do in chem situations for vacuum desiccators? 26-Jan-20 11:15 PM just need to make sure your chamber does not leak much and you have a good valve on it 26-Jan-20 11:31 PM ah - good valve on what part? 26-Jan-20 11:33 PM hii 26-Jan-20 11:37 PM to seal off your chamber from the pump 26-Jan-20 11:37 PM so that it sits at whatever you pump it down to 26-Jan-20 11:37 PM https://en.wikipedia.org/wiki/Desiccator#/media/File:Desiccator.jpg 26-Jan-20 11:37 PM thats what is used often in chem stuff from my little lab experience 26-Jan-20 11:37 PM has a valve on the top that you close off after pumping down and then you just let it sit 27-Jan-20 12:28 AM ahh, thanks! 27-Jan-20 12:45 AM they are sometimes difficult to open :)) 27-Jan-20 12:45 AM esp the larger ones of course ^^ 27-Jan-20 12:45 AM once I dropped one cause of the 'strange' force curve 27-Jan-20 12:45 AM we all survived 27-Jan-20 01:01 AM thanks to the wooden lab floor 27-Jan-20 01:41 AM Is Al 6081 also good for XHV? Or should I stick to 6061 (longer lead time :((() 27-Jan-20 03:44 AM <__ice9#6039> Use zeolites instead of silica gel for desiccation-- they are much more efficient. I only use silica gel as a first pass in gas processing devices and for better protecting items in storage. 27-Jan-20 03:44 AM <__ice9#6039> Zeolite 3A is the best for removing water fwiw 27-Jan-20 03:44 AM <__ice9#6039> 4A/5A/13X also work, granted, but are more tailored for other applications 27-Jan-20 04:45 AM @Spirit @Deleted User we need to ask you some questions to confirm if you are really you 27-Jan-20 04:45 AM You need to pass the test 27-Jan-20 04:46 AM :)) 27-Jan-20 05:52 AM I saw FR-4 and vacuum in the backlog 27-Jan-20 05:52 AM A board I designed does well enough after an extended pumpdown at 10^-6 to -7 mbar 27-Jan-20 05:52 AM And around 90K 27-Jan-20 05:52 AM No soldermask, no silkscreen. just bare board and silver plated traces (the fab shop I used sold it with silvered instead of tinned or enig, so I did not complain). 27-Jan-20 05:52 AM But ENIG was ok at the colder end at 4-10K, but the substrate there was some funky copper substrate pcb due to thermal reasons. 27-Jan-20 07:33 AM I reached app 10^{-9} mbar with a small pcb made out of fr-4 27-Jan-20 07:33 AM I simply cooled the flange on which the pcb was mounted with LN for other reasons ^^ 27-Jan-20 07:33 AM oh and I used some stupid bungard base material 27-Jan-20 07:33 AM and no soldermask etc 27-Jan-20 07:37 AM How did you go about constructing the cryostat to cool the flange? I would've thought conduction through the metal would be way too fast (assuming you are using CF flanges?) 27-Jan-20 07:38 AM yeah simply the 'conductivity' of the flange and the mounting spacer 27-Jan-20 07:39 AM Okay, so I guess it takes quite a bit of LN then, and your entire chamber will be pretty cold 27-Jan-20 07:39 AM so the pcbs temperature was surely way above 77K :)) 27-Jan-20 07:39 AM yeah 27-Jan-20 07:40 AM What was the size of that flange? And how fast did this consume LN? 27-Jan-20 07:44 AM welll cf 2.75" and I dunno I consumed app 15l of LN this day 27-Jan-20 07:44 AM but not only for that experiment 27-Jan-20 07:44 AM + the electronics had a power dissipation of app. 1W 27-Jan-20 07:44 AM that was the reason for the cooling in the first place 27-Jan-20 07:44 AM to prevent that stuff heats up and melt/evaps in the chamber 27-Jan-20 07:44 AM (I tested a quadrupole trap driver) 27-Jan-20 08:04 AM Definitely not something you want to run 24/7 then. Unless you have free LN 27-Jan-20 08:32 AM Did someone say free LN2? 27-Jan-20 08:51 AM I can get some for free from a few lab techs from my school 27-Jan-20 08:51 AM But not a sustainable resource for sure 27-Jan-20 08:53 AM Ours is open m-f 9-5 no access card or key required 27-Jan-20 08:54 AM Like anyone can just walk up to the big dewar and get some for free? 27-Jan-20 08:54 AM They’re not supposed to but yes 27-Jan-20 08:55 AM Oh man that's something I'd use and abuse 27-Jan-20 09:05 AM Reminds me of the stories of a friend who once worked at a very large industrial plant 27-Jan-20 09:05 AM They ware suspicious about large LN2 loss when it was hot 27-Jan-20 09:05 AM Just to find out that the workers used the LN2 on tap to cool their work clothes and shoes 27-Jan-20 09:05 AM And general LN2 was "too cheap to meter" so if they needed it, they just filled some open barrel with it and then ferried it over to where it was needed. 27-Jan-20 09:05 AM Not dewars or anything 27-Jan-20 09:05 AM My understanding was that it was a byproduct of some process. But that sounds just weird. 27-Jan-20 09:33 AM hehe cooling the shoes with LN - neat 27-Jan-20 09:44 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200127_144837-461C0.jpg 27-Jan-20 09:44 AM I have some plasma and TIG consumables 27-Jan-20 09:44 AM I suppose they are made of ceramic and some special glass 27-Jan-20 09:44 AM So they have very low outgassing 27-Jan-20 01:15 PM Joined the server. 27-Jan-20 07:18 PM Joined the server. 27-Jan-20 07:18 PM This is Sрiriт again. I accidently triggered the "too fast" thing on #2 and got automatically disаbled, whoops. Now that one was my fault, a false-positive. Don't mention the name though. 27-Jan-20 07:18 PM Feels like the world is against me at this point, with all the other stuff piling on as well 27-Jan-20 07:18 PM To Squirrel - disregard the message there, PM me here instead 27-Jan-20 07:18 PM Not sure if this one will get punted as well, but I really hope not because I like hanging out here 27-Jan-20 07:31 PM hey, it happens to everyone 27-Jan-20 07:32 PM Occupational hazard with running a big public community I suppose (not this one) 28-Jan-20 12:38 AM What's the practical difference between KF25 steel bellow hoses of different rigidity? I have ones which are kinda hard to bend, and ones from China which are very flexible. I kinda like flexible ones, but not sure what are the disadvantages. 28-Jan-20 12:48 AM usually more expensive, due to some heat Treatment 28-Jan-20 12:48 AM also @Yousername what are you doing that makes discord hate you that much 28-Jan-20 01:41 AM @GigaSquirrel But I assume even very thin steel bellows would not permeate air? 28-Jan-20 01:43 AM sure, the heat treatment is just for the flexibility 28-Jan-20 02:43 AM can you measure the thickness? ^^ 28-Jan-20 02:43 AM and of course - the thicker the better against diffusion 28-Jan-20 02:43 AM normally they seem to have like 0.15 mm thickness 28-Jan-20 02:43 AM at kf25 28-Jan-20 02:43 AM and yeah in general they're a weakness in every vacuum rig 28-Jan-20 02:43 AM question also is: how flexible @ZeptoBars 28-Jan-20 03:03 AM but I assume they are only used for prepumping (kf 25) the higher flexibility outweighs the maybe higher diffusion rate 28-Jan-20 03:35 AM ok my cf40 ones are wobblier than the kf25 - now I'm feeling unsettled 28-Jan-20 04:03 AM @GigaSquirrel I honestly have no idea. I'm not in the wrong and I know it. See if you can do the thing in a PM from the other one but on this one please. 28-Jan-20 04:04 AM what, the invitation for the other server? 28-Jan-20 04:05 AM Yeah and the gauge role since I lost it 28-Jan-20 04:05 AM I'll get to it when I wake up, still sleeping but was dealing with FedEx 28-Jan-20 04:09 AM who knows how long this Account will last 28-Jan-20 04:09 AM Hopefully forever since I don't think it's prohibited 28-Jan-20 06:19 AM RIP my cryo setup 28-Jan-20 06:19 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-51347.png 28-Jan-20 06:19 AM but I instantly got a refund from ebay over the whole amount 28-Jan-20 06:24 AM what do the roles on here mean anyway? 28-Jan-20 06:25 AM the red ones are Admins 28-Jan-20 06:25 AM the yellow ones is the dead gauge society, a bit of an insider joke 28-Jan-20 06:25 AM doesn't give any extra rights, just says that you have an instrutech hot cathode gauge 28-Jan-20 06:25 AM there once were tons of them on ebay for cheap and they're good meters, but all of them had dead caps 28-Jan-20 06:25 AM became a bit of a running gag 28-Jan-20 06:49 AM the helium compressor or what? 28-Jan-20 06:49 AM oversized :(( 28-Jan-20 07:02 AM compressor, pump, unknown accessories 28-Jan-20 07:48 AM @N00N Stiffness affects transmission of vibrations, so they are sometimes preferred depending on what's going on in the system. The stiffer ones are a lot cheaper to make, too. I wouldn't worry about it, we use both types of KF ones for rough and fairly high vacuum with no problems, and the lab next door has conflat bellows of each type used in their UHV ion-pumped systems so diffusion is not a big issue either. 28-Jan-20 07:48 AM If you're designing from scratch and using them in a straight line, the stiffer ones are much preferred because they put a lot less stress on what they attach to, too. 28-Jan-20 09:02 AM LIGO vacuum system should be a wonder of the world tbh 28-Jan-20 09:17 AM @idmb my uhv/xhv stuff also have cf bellows 28-Jan-20 09:17 AM of course diffusion is a thing ^^ 28-Jan-20 09:18 AM I meant in the difference between stiff and flexible 28-Jan-20 09:18 AM such bellows have very large surfaces etc 28-Jan-20 09:18 AM ah ok well it's better if the valve isolates the bellows - that's what I mean 28-Jan-20 09:18 AM if they are long bellows 28-Jan-20 09:18 AM like the one you would normally use for kf25 - but then the kf itself would be a larger problem I guess 28-Jan-20 09:23 AM Longest we have is 3ft 28-Jan-20 09:23 AM From disassembled ultracold atom stuff 28-Jan-20 09:24 AM thats also my longest in use 28-Jan-20 09:24 AM in an ion cooling rig 28-Jan-20 09:24 AM but it's between the TMP and the crosses with the laser cooling chamber and the IGP 28-Jan-20 09:24 AM valves for isolation of course 28-Jan-20 09:24 AM in normal operational mode it only needs the igp of course 28-Jan-20 12:20 PM If I’m only trying to be at like 25-50 mtorr range is having some Teflon parts in my chamber fine? 28-Jan-20 12:22 PM for sure 28-Jan-20 12:23 PM A fresh PTFE surface, for example, is reported to have an outgassing rate of 1.7 x 10-7 Torr-Liter/sec-cm2 at 25°C after 1 hour under vacuum. 28-Jan-20 12:25 PM awesome thank you! 28-Jan-20 01:32 PM <__ice9#6039> @GigaSquirrel other server? 28-Jan-20 01:33 PM not an alternative to this server, just another server him and me happen to be on 28-Jan-20 02:22 PM Is it a good idea to cool fore-vacuum trap with silica-gel or zeolite to -20°C to improve vacuum quality after TMP (less oil and H2O)? 28-Jan-20 03:56 PM <__ice9#6039> Zeolite is generally better 28-Jan-20 03:56 PM <__ice9#6039> And yes it is a common filler material in foreline traps, which can indeed be chilled 28-Jan-20 05:52 PM @__ice9 But does -20°C offer significant advantages with zeolite? I've seen cryo traps with LN2 which is quite a bit less than -20°C.... 28-Jan-20 10:54 PM uh oh is this here going to die? 29-Jan-20 03:11 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200129_120826-EA96A.jpg 29-Jan-20 03:23 AM :)) 29-Jan-20 03:23 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-8AC21.jpg 29-Jan-20 03:23 AM mine 29-Jan-20 03:30 AM That "do not disturb" laser sign is a neat idea. 29-Jan-20 03:30 AM imo 29-Jan-20 04:34 AM The lights go blinky. There's a cutout to access battery hatch and switch 29-Jan-20 05:32 AM fancy 29-Jan-20 06:51 AM anyone have any info on the jeol JSM-6100? 29-Jan-20 06:52 AM @AdamMcCombs might 29-Jan-20 07:08 AM I have one information about it 29-Jan-20 07:08 AM Ok, maybe two 29-Jan-20 07:08 AM I want one & I would take it 29-Jan-20 07:08 AM SEM are good friends 29-Jan-20 09:51 AM <__ice9#6039> LN2 is obviously better. I was speaking about sorbent efficiency for zeolite vs silica gel though. 29-Jan-20 08:24 PM Having issue with sputter coater. Last few runs with new design I get a bright pink/red color plasma. I’m assuming this is due to oxygen? (Copper cathode, 2 kV, probably 100 ish mtorr) 29-Jan-20 08:24 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-393B4.jpg 29-Jan-20 08:24 PM Now one run that actually sputtered have me this more purple tone. 29-Jan-20 08:24 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-16CBB.jpg 29-Jan-20 08:24 PM Wasn’t able to get back to this after that run 29-Jan-20 08:24 PM Any ideas? When I turn off the pump for a second it’ll go this shade too 29-Jan-20 08:24 PM The spots on the wall are where sparks alblated the aluminum 29-Jan-20 08:32 PM leaks, definitely leaks 29-Jan-20 09:38 PM <__ice9#6039> Try more high vac grease at all of the seals including that fitting at bottom right, especially if threaded 29-Jan-20 10:00 PM Using ptfe tape on all the threads. 29-Jan-20 10:01 PM it's unlikely that will work unless it's super tight 29-Jan-20 10:01 PM I've had issues with ptfe for vacuum 30-Jan-20 02:31 AM <__ice9#6039> Yep suspected that. Just use high vac grease in the threads instead. Works much better. 30-Jan-20 05:56 AM ok 30-Jan-20 11:24 AM How long does a turbo last, running? 30-Jan-20 11:24 AM Presumably magnetic vs normal bearings make a/the difference. 30-Jan-20 11:34 AM magnetics should last pretty much forever 30-Jan-20 11:34 AM regular turbos have lifetimes in their datasheets 30-Jan-20 11:34 AM many thousands of hours from what I've read 30-Jan-20 11:51 AM Oh, awesome, my main FIB chamber pump is a 3 axis magnetic 30-Jan-20 11:51 AM My loadlock says: High vacuum side: Wear free permanent magnetic bearing. Fore-vacuum side: Oil circulatory lubricated ball bearing with ceramic balls. 30-Jan-20 11:53 AM that's a regular turbopump 30-Jan-20 11:53 AM a lot of turbos have a magnetic top bearing and regular bottom 30-Jan-20 11:53 AM I don't see a spec for hours on that one 30-Jan-20 11:53 AM Hmm, says oils replacement once a year 30-Jan-20 11:53 AM Ha, it says if the pump was shut down for 3 years the bearing needs replaced 30-Jan-20 11:53 AM Good thing i only had it off for 2 years 30-Jan-20 12:31 PM Going to try vac-grease tonight. Are there other ways to seal up a threaded feed through ? 30-Jan-20 12:31 PM Maybe an epoxy of sorts for something more permanent? 30-Jan-20 12:43 PM Orings on the flat surfaces 30-Jan-20 01:46 PM Epoxy: Torr seal aka hysol 1c 30-Jan-20 01:46 PM If i wanted to bond the end of a PVC pipe to a sheet of silicone gasket material... Should I use RTV silicone (alcohol releasing type) or hysol 1c? 30-Jan-20 02:04 PM rtv silicone will stink/outgas foreeeeever 30-Jan-20 02:04 PM i tried using it once to make a makeshift gasket on a crock pot vacuum chamber and it prevented me from getting below 20 torr 30-Jan-20 02:04 PM swapped that for a viton rubber gasket and average around 500 mtorr-ish now 30-Jan-20 02:07 PM Hmm, we're getting 9 torr now with some rtv, it was connecting the pvc to a piece of foamy gasket material 30-Jan-20 02:07 PM Was thinking the foamy stuff might be virtual leaking like crazy 30-Jan-20 02:07 PM Was thinking to swap it for the solid silicone sheet 30-Jan-20 02:07 PM I wonder if epoxy will bond silicone to PVC 30-Jan-20 02:39 PM Also Duniway partial rebuild for my D2A got here today, its actually nice and complete. It has everything from new fill/drain plugs, all shaft seals, rubbers, new rubber motor->pump coupling, and a new filter element for the ballast!! 30-Jan-20 02:39 PM So its actually VERY complete for what I was expecting. 30-Jan-20 02:40 PM nice :D 30-Jan-20 02:40 PM kit, or did you have them do it for you? 30-Jan-20 02:47 PM Kit I will do it probably over the weekend or something 30-Jan-20 02:50 PM spiffy :D 30-Jan-20 02:50 PM time to get filthy 30-Jan-20 04:22 PM <__ice9#6039> Don't use silicone as a facing layer inside a chamber 30-Jan-20 04:22 PM <__ice9#6039> It's ok as a layer inside a pass-through, preferably the outermost layer, but the innermost layer should be something with much less outgassing and lower permeability-- like vacuum grade epoxy or high vac grease under aluminum foil 30-Jan-20 04:22 PM <__ice9#6039> In general, clean metal foils and glass can be relied upon for low permeability and negligible outgassing. 30-Jan-20 04:27 PM Foil? 30-Jan-20 04:27 PM Like with a clamp mechanism? 30-Jan-20 04:28 PM <__ice9#6039> The permeability characteristics of various elastomers, plastics, and resins vary widely, and differ across different gases/vapors. Where an elastic seal is needed, it can be useful to layer multiple such materials with different permeability characteristics. Also it can be useful to embed metal foils between layers to block off most of the area across which diffusion through the material can occur. 30-Jan-20 04:28 PM Hmm 30-Jan-20 04:30 PM <__ice9#6039> It's merely about further decreasing the diffusion rate when using materials with non-negligible permeability 30-Jan-20 04:30 PM <__ice9#6039> Incidentally metals are not perfect-- they do leak e.g. hydrogen 30-Jan-20 04:30 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Diffusion-coefficients-of-hydrogen-in-diff-1B8DC.png 30-Jan-20 04:30 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Reported-values-for-the-hydrogen-diffusion-598CD.png 30-Jan-20 04:30 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/3-s2.0-B9780857095367500040-f04-02-9780857-51F03.gif 30-Jan-20 04:30 PM <__ice9#6039> If you have the means, it is usually better to use a glass/ceramic to metal seal, but getting them right is challenging 30-Jan-20 04:30 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Oxygen-and-water-vapor-permeability-of-som-E2979.png 30-Jan-20 04:30 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/B-Oxygen-and-Water-Vapor-Permeability-of-C-E6895.png 30-Jan-20 04:30 PM <__ice9#6039> Baking out elastomers after using them to make a pass-through can help a bit with the offgassing problem, but not with permeability 30-Jan-20 04:30 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/007556-12-December_PermeabilityOf-Compound-57756.png 30-Jan-20 04:30 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/e140n2-D0DC4.png 30-Jan-20 04:45 PM Oh hey, account #2 is back. 30-Jan-20 04:45 PM <__ice9#6039> An imperfect glass to metal seal could be patched up by greasing over the leaky boundary surface-- I suspect it would likely still outperform an elastomer filled pass-through. But again not everyone wants to melt glass to make them. And it is better to do it right if at all. 30-Jan-20 04:45 PM <__ice9#6039> Congrats haha 30-Jan-20 04:45 PM <__ice9#6039> In contrast to melting, ceramic-to-metal seals are often made by brazing the ceramic to the metal-- e.g. https://altairusa.com/brazing-ceramic-to-metal/ 30-Jan-20 04:45 PM <__ice9#6039> This is a more elaborate process than just melting glass though 30-Jan-20 07:34 PM I found a great compromise for experimenting with filling nixies @Charles 30-Jan-20 07:34 PM A supplier in Russia has a big stock(160 pieces) of IN14s and IN16s, some used and some new, but all with no gas/slightly defective 30-Jan-20 07:34 PM And he's willing to sell them under 30 cents a piece 30-Jan-20 07:34 PM sadly all soviet tubes are soda lime, so annealing is super required :( 30-Jan-20 07:53 PM Yes but at the price you can experiment to find proper temperatures and times 30-Jan-20 07:53 PM hopefully yeah 30-Jan-20 08:09 PM any tips on the annealing profiles? 30-Jan-20 08:09 PM from what I can see soda lime glass wants to be annealed around 550C for a few minutes 31-Jan-20 08:55 AM https://www.ebay.co.uk/itm/Thomas-Swan-EPITOR-Epison-II-MOCVD-1x2-Quartz-Reactor-Lepel-RF-Heater-Deposition/192851090811 31-Jan-20 08:55 AM I don't know what it does BUT I WANT IT 31-Jan-20 08:55 AM what does it do? 31-Jan-20 08:58 AM vacuum quartz tube induction furnace process chamber?? I dunno what it would have been used for specifically but lots of nice bits on there. 31-Jan-20 08:58 AM Personally this looks like a better bang for your high vacuum buck :P https://www.ebay.co.uk/itm/GEN-II-MBE-SYSTEM-REACTOR/173158084069 31-Jan-20 09:48 AM <__ice9#6039> spiky 31-Jan-20 09:48 AM <__ice9#6039> Oh that quartz one is for doing CVD in a quartz tube with an induction heater for thin film stuff 31-Jan-20 09:48 AM <__ice9#6039> "Metalorganic vapour-phase epitaxy, also known as organometallic vapour-phase epitaxy or metalorganic chemical vapour deposition, is a chemical vapour deposition method used to produce single- or polycrystalline thin films." 31-Jan-20 09:48 AM <__ice9#6039> Speaking of which: if you have a tube furnace, a quartz tube, and a questionable improvised method of grafting a KF flange onto said tube, you have a vacuum furnace 31-Jan-20 10:41 AM heh yea, thats just done a little nicer 31-Jan-20 10:41 AM I plan to machine adapters for my tube furnace A) When its actually built B) when I have access to a lathe :) 31-Jan-20 11:36 AM <__ice9#6039> KF flange + big fat oversized silicone o-ring squished under it against the glass ^^ what could go wrong 31-Jan-20 11:36 AM <__ice9#6039> Well aside from sucking the tube down the vacuum hose anyway 31-Jan-20 11:36 AM <__ice9#6039> Maybe weld a small steel bar across the inside of the flange, or instead use a flange fitting with a barrel narrow enough to fit into the tube 31-Jan-20 11:45 AM so what about a metal 55-gallon drum being used for a chamber? seems like they'd be strong enough... like, I've stood on them before and I feel like I've seen them being jumped on from the side (maybe circus videos or something?) 31-Jan-20 11:50 AM ehhhhh... I dunno about that chief, but I suppose maybe? I think I have only heard of them crushing under pressure under water... 31-Jan-20 11:50 AM I wouldn't trust it lol 31-Jan-20 11:50 AM don't think they're rated for those kinds of hoop stresses 31-Jan-20 11:50 AM stand on the side of one and it'll probably buckle in 31-Jan-20 11:50 AM maybe if you found a weird corrugated one 31-Jan-20 11:51 AM yea... or put in virtual leak-full welded in supports 31-Jan-20 12:02 PM if reactive species aren't really gonna be present (i.e. sputtering or etch, plasma)... is plain steel OK for a chamber? 31-Jan-20 12:05 PM As long as it's very dry and free of corrosion 31-Jan-20 12:05 PM https://media.discordapp.net/attachments/499873492477411339/672895144948924426/20200131_150443.JPG 31-Jan-20 12:05 PM Lets see if I end up with a not leaking good pump after 31-Jan-20 12:05 PM your pump is sitting the wrong way up 31-Jan-20 12:05 PM har har 31-Jan-20 12:26 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200131_152605-84088.JPG 31-Jan-20 12:26 PM that looks relatively clean 31-Jan-20 12:26 PM https://www.youtube.com/watch?v=IUrEdExiwko 31-Jan-20 01:01 PM <__ice9#6039> No, do not ever use an oil drum as a vacuum chamber; they implode 31-Jan-20 01:01 PM <__ice9#6039> https://m.youtube.com/watch?v=ba45dJ7trjQ 31-Jan-20 01:01 PM <__ice9#6039> If you want a really huge chamber, I did once make one using a WinCo 160L thick aluminum stockpot, an aluminum alloy tube about 2" OD walls 0.25" as a central support, a 24-inch acrylic circle, some nitrile gasket material, and... one cast iron Model T car wheel, de-rusted and angle-ground to barely fit into the pot and then press-fit against the walls about 2/3rds of the way up 31-Jan-20 01:01 PM <__ice9#6039> The acrylic should be 1" nominal 31-Jan-20 01:01 PM <__ice9#6039> (or better) 31-Jan-20 01:01 PM <__ice9#6039> That was a bit silly but it serves its purpose-- hold better than 50 microns for cryo insulation 31-Jan-20 01:01 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/1580504904200-B8395.png 31-Jan-20 01:09 PM Acrylic ISO250 flanges are 1" thick 31-Jan-20 01:09 PM I got some quotes and they were all that thick 31-Jan-20 01:10 PM <__ice9#6039> I have no idea whether this would work without the hoop support and central strut. I calculated the net forces on it as something like 16 tons 31-Jan-20 01:10 PM <__ice9#6039> It's large enough to sit in comfortably lolol 31-Jan-20 01:10 PM <__ice9#6039> https://www.montanainstruments.com/help/Window-Thickness-Calculator/ useful 31-Jan-20 01:16 PM 18" x 1" acrylic gives a safety factor of 12, nice. 31-Jan-20 01:24 PM <__ice9#6039> Acrylic is a particularly suitable material for viewports, albeit not usable in UHV 31-Jan-20 01:24 PM <__ice9#6039> It substantially outperforms e.g. fused silica 31-Jan-20 02:03 PM if I put a safety box around it so it doesn't get opened accidentally, any reason not to use an unclamped kf blank as an overpressure burst valve 31-Jan-20 02:03 PM I guess "stickiness" could hold it shut at mild overpressure 31-Jan-20 02:11 PM <__ice9#6039> It would still blow way before any viewports did 31-Jan-20 02:11 PM <__ice9#6039> So probably still ok 31-Jan-20 02:11 PM <__ice9#6039> But idk, leakage rate might be worse than clamped ones 31-Jan-20 02:30 PM Only worried about turbos 31-Jan-20 02:30 PM Not viewports 31-Jan-20 02:35 PM <__ice9#6039> Hmm why is some overpressure any worse than atmosphere for a turbo? If it's spinning, it's scrap either way. 31-Jan-20 02:35 PM <__ice9#6039> Are they overpressure sensitive when halted for some reason? 31-Jan-20 03:04 PM @__ice9 unfortunately I need something at least 10" in diameter and 2.5 ft tall... so a big stock pot won't work 31-Jan-20 03:04 PM and yeah, I just found some youtube myself https://youtu.be/ogY7rRIdrxI?t=173 31-Jan-20 03:04 PM I found a person locally selling carbon steel pipe that's 0.375" thick for $8 a linear foot... they says it's ~50 lbs per ft 31-Jan-20 03:12 PM <__ice9#6039> Um put one stockpot over another one and weld the rim 31-Jan-20 03:13 PM eh, if I need to get into welding, I might as well just buy some pipe 31-Jan-20 03:13 PM <__ice9#6039> Given you have suggested oil barrels, this clearly isn't for UHV, so you shouldn't have to worry about virtual leaks from minor weld porosity 31-Jan-20 03:13 PM nah, this is for vapor deposition 31-Jan-20 03:13 PM <__ice9#6039> Huh interesting 31-Jan-20 03:13 PM lowest pressure I've seen is like 100mTorr 31-Jan-20 03:13 PM <__ice9#6039> What kind? 31-Jan-20 03:13 PM FDTS 31-Jan-20 03:13 PM anti-stick layer 31-Jan-20 03:13 PM came across this bad boy when searching for 55 gallon drum vacuum chamber: https://abbess.com/wp-content/uploads/2016/01/AMCSZ_00082.jpg 31-Jan-20 03:13 PM I guess for degassing drum-fulls of stuff 31-Jan-20 03:13 PM and the chef in me really likes the idea of this vacuum mixer https://abbess.com/wp-content/uploads/2016/01/AZCRZ_00084-282x300.jpg 31-Jan-20 03:15 PM <__ice9#6039> Big chamber yeah 31-Jan-20 03:15 PM <__ice9#6039> FDTS probably improves chemical resistance also 31-Jan-20 03:16 PM yeah, likely 31-Jan-20 03:16 PM <__ice9#6039> Very low surface energy 31-Jan-20 03:17 PM figuring out the deposition surface prep (for nickel) has been challenging since no one seems to have really published a thorough analysis 31-Jan-20 03:17 PM most stuff is about depositing on SiO2 31-Jan-20 03:17 PM or if they do some metal, they add some layers of SiO2 first 31-Jan-20 03:17 PM or they just do directly onto nickel, but then the FDTS wears off pretty soon 31-Jan-20 03:18 PM <__ice9#6039> Yeah it's covalent so.... 31-Jan-20 03:18 PM <__ice9#6039> Maybe try oxidizing the nickel a little bit first 31-Jan-20 03:19 PM well that's the problem, there's at least 2 or 3 nickel oxides 31-Jan-20 03:19 PM and the traditionally talked about FDTS coupling chemistry needs a terminal OH 31-Jan-20 03:19 PM which oxide isn't 31-Jan-20 03:19 PM and there's at least 2 nickel hydroxides 31-Jan-20 03:19 PM so at this point it seems like a bunch of experiments are needed... but also, I really feel like some sort of surface analysis would be beneficial to see what layers are existing before deposition... which means more tooling needed 31-Jan-20 03:23 PM <__ice9#6039> Yes 31-Jan-20 03:23 PM <__ice9#6039> Acid piranha solution hydroxylates glasses. Maybe it might work on nickel oxides, but I'm not sure. 31-Jan-20 03:25 PM hmm 31-Jan-20 03:25 PM we found a paper using H2O2 to oxidise nickel 31-Jan-20 03:25 PM adding in the H2SO4... hrmm 31-Jan-20 03:27 PM <__ice9#6039> Hey it works on alumina too-- makes it reactive by adding hydroxyl groups 31-Jan-20 03:27 PM <__ice9#6039> I strongly suspect this would work on nickel oxide 31-Jan-20 03:27 PM <__ice9#6039> Provided it doesn't penetrate. Nickel is pretty corrosion resistant, so there's a good enough chance imo for a small test run on a little piece of sheet metal or whatever 31-Jan-20 03:29 PM hmm, reddit post says "nickel oxide is pretty insoluble. sulfuric acid will do the trick though. Or my personal favourite, Piranha solution, eats anything. " 31-Jan-20 03:29 PM definitely can't have any dissolution happening... as the surface will have nanofeatures defined originally by e-beam litho 31-Jan-20 03:31 PM <__ice9#6039> I'm not sure whether I trust Reddit on this 31-Jan-20 03:31 PM (this is for imprint lithography, roll-to-roll printing press style... will need to be used for 10s of 1000s of impressions) 31-Jan-20 03:31 PM haha 31-Jan-20 03:32 PM in my experience nickel is not very corrosion resistant at all when acids are in the mix 31-Jan-20 03:33 PM a journal on battery electrodes says "The behavior of the Ni in strongly acidic solutions (H 2 SO 4 , pH 1.0), has been extensively studied (12-15). It’s reported that a passivating film forms on the nickel electrode in the acidic solution. The addition of H 2 O 2 into the acidic media changes the potentiodynamic behavior of Ni significantly. Du et.al investigated the role of H 2 O 2 in the oxide formation and the ionic dissolution of nickel using electrochemical methods. It was observed that the cathodic reduction of H 2 O 2 predominated over the anodic dissolution of Ni. In contrast to the passivation behavior of Ni in peroxide-free solution, Ni shows an active dissolution in solutions containing H 2 O 2 (12)." 31-Jan-20 03:33 PM but that's with voltage added, presumably 31-Jan-20 03:36 PM <__ice9#6039> You can anodize nickel 31-Jan-20 03:36 PM "EDAX measurements were employed to investigate the local surface structure and composition of Ni surface covered with oxide, hydroxide and salt. However the chemical nature of hydroxylation (bulk Ni(OH) 2 or hydrated NiO) is not clear even with EDAX analysis." 31-Jan-20 03:36 PM <__ice9#6039> If that paper used an applied voltage then the results are totally irrelevant 31-Jan-20 03:36 PM <__ice9#6039> Yeah that's more interesting 31-Jan-20 03:37 PM seems like I'd need Raman or XPS to detect 31-Jan-20 03:37 PM <__ice9#6039> Yeah that's.. tricky 31-Jan-20 03:37 PM mmm 31-Jan-20 03:37 PM and I don't think I know anyone with them, and experience using them on thin films 31-Jan-20 03:38 PM <__ice9#6039> Maybe just try anodizing nickel and seeing whether piranha solution still attacks it 31-Jan-20 03:38 PM "The comparison of Figure 7a and Figure 7b shows that the surface exposed to H 2 SO 4 is rougher than that of the untreated Ni surface." 31-Jan-20 03:38 PM <__ice9#6039> >definitely can't have any dissolution happening... as the surface will have nanofeatures defined originally by e-beam litho NVM this is incompatible with anodizing 31-Jan-20 03:38 PM <__ice9#6039> So piranha probably isn't the way to go here. It needs a thick oxide layer to work on. Otherwise it will just dissolve the metal. 31-Jan-20 03:38 PM <__ice9#6039> Any way to CVD hydroxyls...? 31-Jan-20 03:40 PM I wish! 31-Jan-20 03:40 PM (maybe, idk) 31-Jan-20 03:40 PM I was thinking of like, flushing the chamber with Hydrogen plasma... 31-Jan-20 03:40 PM feels dangerous tho 31-Jan-20 03:40 PM but also simple 31-Jan-20 03:40 PM hmm, so XPS is shooting x-rays and watching the electrons that come off... I wonder if my everhart thornley detector could be used for the detection... just modifying the bias voltage to collect the spectrum 31-Jan-20 03:40 PM https://upload.wikimedia.org/wikipedia/commons/f/f2/System2.gif 31-Jan-20 03:55 PM <__ice9#6039> Try an atomic hydrogen torch first maybe 31-Jan-20 03:55 PM <__ice9#6039> That way it at least burns off on an ongoing basis instead of collecting in one place 31-Jan-20 03:55 PM <__ice9#6039> NVM don't do that; it would just reduce the oxide entirely off 31-Jan-20 03:55 PM <__ice9#6039> More diffuse colder plasma would have a better chance at it 31-Jan-20 03:55 PM <__ice9#6039> https://pubs.acs.org/doi/10.1021/ja0121080 31-Jan-20 03:55 PM <__ice9#6039> https://en.wikipedia.org/wiki/Nickel_oxide_hydroxide 31-Jan-20 04:02 PM It is a black solid that is insoluble in all solvents 31-Jan-20 04:02 PM that's a fun description 31-Jan-20 04:03 PM <__ice9#6039> some probably dodgy patent, but worth noting that nickel oxide hydroxide and nickel hydroxide can both be produced by reaction of nickel compounds with KOH-- so it isn't totally implausible 31-Jan-20 04:03 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/1580515378039-F36AD.png 31-Jan-20 04:04 PM it can also be produced by the purchase of NiMH batteries 31-Jan-20 04:06 PM <__ice9#6039> Trying again, some image loading issue 31-Jan-20 04:06 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/1580515544588-27049.png 31-Jan-20 04:06 PM <__ice9#6039> Hmm 31-Jan-20 04:06 PM the images load if you click on them and open the link 31-Jan-20 04:06 PM yeah I can see 31-Jan-20 04:06 PM <__ice9#6039> Huh just for me then ok 31-Jan-20 04:06 PM <__ice9#6039> https://patents.google.com/patent/US20110195293 31-Jan-20 04:06 PM if you right click and open in new tab 31-Jan-20 04:06 PM yeah 31-Jan-20 04:06 PM I think I want Ni(OH)2 31-Jan-20 04:06 PM since the trichlorosilane supposedly goes and attacks OH groups, with the Cl and H evolving HCl and leaving a covalent bond behind 31-Jan-20 04:07 PM <__ice9#6039> Suggest experiments with different concentrations of KOH for different time periods as a start 31-Jan-20 04:07 PM <__ice9#6039> The need to hydroxylate it after the ebeam micromachining is a little tricky though 31-Jan-20 04:07 PM <__ice9#6039> Because some degree of surface etching seems likely 31-Jan-20 04:11 PM well, the process is e-beam litho on photoresist, then electroplating that to build up nickel copy, then dissolve off the photoresist 31-Jan-20 04:11 PM then magic hydroxylation, then FDTS vapor deposition 31-Jan-20 04:11 PM we have a few electroforms with various degrees of failure, so I can run some tests 31-Jan-20 04:11 PM I know that residual-atmosphere plasma doesn't harm the surface, at least 31-Jan-20 04:11 PM KOH is simple enough to try 31-Jan-20 05:08 PM Does anyone know how this thing operates? 31-Jan-20 05:08 PM https://www.nolek.com/wp-content/uploads/2015/09/X1_PDF_20150816_v2.pdf 31-Jan-20 05:08 PM They keep claiming "unique patented sniffit technology", but I can find no such patent. 31-Jan-20 05:41 PM https://youtu.be/p3NC27iZJyw?t=109 31-Jan-20 05:41 PM not sure if this is accurate but this is what they claim 31-Jan-20 05:44 PM Anyone know a really nice way to mount these ? 31-Jan-20 05:44 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/SS-1RS4-610A9.png 31-Jan-20 06:02 PM @LRM a bit of a ballsy explanation 31-Jan-20 06:02 PM with totally made-up terms 31-Jan-20 06:02 PM hence why i said i have no idea if it is accurate 31-Jan-20 06:02 PM "megasonic gas interferometry" 31-Jan-20 06:03 PM seems like more technobabble 31-Jan-20 06:03 PM ultracookie mug spectroscopy and turbomolecular tea would go well with that 31-Jan-20 06:03 PM i like the super simplified animation of the gas path using just arrows 31-Jan-20 06:03 PM it all seems a bit fishy to me 31-Jan-20 06:03 PM like it's a handmade product stuffed into a pretty shell, with an arduino inside 31-Jan-20 06:04 PM you dont think a badly animated youtube video doesnt give it credibility? 31-Jan-20 06:04 PM it does seem to work 31-Jan-20 06:04 PM but something is fishy 31-Jan-20 06:04 PM totally agree...who is biting the bullet and cracking one open? 31-Jan-20 06:04 PM they are $request a quote 31-Jan-20 06:04 PM so probably nobody 31-Jan-20 06:07 PM a slightly less pessimistic explanation might be that the wording for the "megasonic gas interferometry" is actually Swedish derived Engrish 01-Feb-20 03:18 AM <__ice9#6039> @Spirit 01-Feb-20 03:18 AM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/1580555889708-2D03E.png 01-Feb-20 03:18 AM <__ice9#6039> Maybe it's just using a gas sensor similar to those in service for hazardous environment atmosphere monitoring 01-Feb-20 11:42 AM is there any benefit/drawbacks of steel vs aluminum as a base for sputtering chamber? i'm using a glass bell jar on top 01-Feb-20 11:46 AM <__ice9#6039> Aluminum is a better thermal conductor fwiw 01-Feb-20 11:46 AM <__ice9#6039> If you are water cooling then it does not matter though 01-Feb-20 11:48 AM yeah atm water cooling the magnet...i sprayed the magnets with a clear coat so water wouldn't touch it but not thick enough, i see rust forming. oops 01-Feb-20 11:54 AM was your clear coat vacuum compatible? 01-Feb-20 11:54 AM might not be that it wasn't thick enough but that it was losing mass 01-Feb-20 11:56 AM Sounds like the magnets were outside of the vacuum 01-Feb-20 11:56 AM Since water was involved 01-Feb-20 11:59 AM oh duh haha 01-Feb-20 12:03 PM in this case the magnet+water block is external, but don't put it past me to not realize that it shouldn't be inside 01-Feb-20 12:04 PM is it nickel plated and still having corrosion issues or just one of the bare magnets? 01-Feb-20 12:04 PM swapping magnets might be your easiest answer 01-Feb-20 12:23 PM i took it out of a microwave 01-Feb-20 12:23 PM the center magnet is a neodymium ring (was considering piping HV through the center) 01-Feb-20 01:10 PM currently thinking this setup for sputtering - anything look missing/blatantly terrible? 01-Feb-20 01:10 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-1D8A9.png 01-Feb-20 01:10 PM (the power/MCU stuff might change to simplify things but i'm less worried about that, it's the vacuum stuff I have no idea about) 01-Feb-20 01:11 PM going from the turbo down to KF25 is going to choke it very severely 01-Feb-20 01:13 PM part of that is $$...not sure what's involved using the ISO100 inlet yet and guessing it will be pricey to get attached, even if i build the connections 01-Feb-20 01:13 PM but open to it 01-Feb-20 01:13 PM You already have a KF25 port on the side of the pump 01-Feb-20 01:14 PM That KF25 port is for foreline only though, have to keep that in mind 01-Feb-20 01:14 PM If it's not enough then you can adapt the ISO100 main inlet 01-Feb-20 01:14 PM you can go from ISO100 to ISO63, then ISO63 to KF50 01-Feb-20 01:14 PM KF50 is still going to choke, but that's a relatively affordable hop 01-Feb-20 01:14 PM No, I'm referring to the interstage high vacuum KF25 port 01-Feb-20 01:15 PM oops i forgot the MOT on the HV section 01-Feb-20 01:16 PM actually, looks like you can go straight from ISO100 to KF50 01-Feb-20 01:16 PM but if you're attaching the turbo to the aluminium plate, you should just fabricate an ISO100-compatible flat spot(with a hole) in the plate, and bolt it directly to the turbo 01-Feb-20 01:19 PM what would the other side go to? the plate for the bottom of the bell jar will be where all the inlets are so don't think i'll be able to use that same plate 01-Feb-20 01:19 PM that's where it should go 01-Feb-20 01:19 PM next to the inlets 01-Feb-20 01:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-DD8F6.png 01-Feb-20 01:19 PM this way 01-Feb-20 01:21 PM You should still keep the outer part of the centering ring 01-Feb-20 01:21 PM And yeah you need a pretty thick plate 01-Feb-20 01:21 PM doesnt that show the turbo being choked down all the way to KF16 hose between it and the chamber? 01-Feb-20 01:21 PM that's what I'm suggesting he fix this way 01-Feb-20 01:21 PM by mounting the turbo directly 01-Feb-20 01:21 PM and I would get this kind of centering ring 01-Feb-20 01:21 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/OverPressureISO_Ring1-20DA1.png 01-Feb-20 01:21 PM as Mason suggested, the outer side ensures it's level and isn't crushed 01-Feb-20 01:23 PM @samy You don't necessarily need to gate off the turbo from your chamber, and with a KF16 hose (even if it's short) the pumping speed of the turbo is going to be very small 01-Feb-20 01:23 PM Just due to conductance losses 01-Feb-20 01:23 PM ok - by gate off you mean the valve? i think i'd gate it off when backfilling with argon? 01-Feb-20 01:23 PM The valve to isolate the chamber can be in your foreline 01-Feb-20 01:24 PM side note: running the turbo without a backing pump(gated off) is not a good idea 01-Feb-20 01:24 PM so you'd just turn the turbo off 01-Feb-20 01:24 PM does that mean i have to turn the TMP off if i use the valve on the foreline since the TMP outlet can't be at atmosphere? 01-Feb-20 01:24 PM You won't run the turbo when your chamber is full of argon yeah 01-Feb-20 01:24 PM oh wait i guess it would still be under vacuum 01-Feb-20 01:24 PM yeah 01-Feb-20 01:24 PM when using gases, you should turn the turbo off, because a high sustained gas load can overheat a turbo 01-Feb-20 01:24 PM it's not going to kill it, since the brains are smart, but it's unhealthy for it 01-Feb-20 01:25 PM ok so turn turbo off, then gate foreline, then backfill argon, then turn on HV 01-Feb-20 01:25 PM yes 01-Feb-20 01:25 PM you're using the turbo to clean the chamber out, then you fill with gas 01-Feb-20 01:25 PM you can also buy an ISO100 gate valve to speed the process up 01-Feb-20 01:25 PM but those are rare 01-Feb-20 01:28 PM But if you already have a KF16 port on the aluminum plate and already got all the components in your diagram, I'd just build it and test it out 01-Feb-20 01:28 PM If the pumping speed is too low, then consider modifying the aluminum base plate 01-Feb-20 01:28 PM To mount the turbo directly 01-Feb-20 01:31 PM Wouldn't you want to gate the foreline first? Before turning off the turbo. 01-Feb-20 01:32 PM no, never 01-Feb-20 01:32 PM you turn the turbo off and let it spin down to a fraction of the speed, then you can purge it a bit 01-Feb-20 01:33 PM i haven't created the chamber yet or gotten the plates 01-Feb-20 01:33 PM i have the foreline trap (KF25), two KF16 hoses, a bunch of KF16 splitters/stuff, and can turn some KF stuff (mini lathe) 01-Feb-20 01:35 PM https://www.midweststeelsupply.com/store/castaluminumplateatp5 01-Feb-20 01:35 PM @Spirit wait, but turning off the turbo first seems like you'd get backstreaming into the chamber 01-Feb-20 01:35 PM assembling a mini mill this weekend so i can mill stuff, and setting up a TIG 01-Feb-20 01:35 PM @nmz787 your foreline shouldn't backstream 01-Feb-20 01:35 PM Well, not oil 01-Feb-20 01:35 PM Just molecules 01-Feb-20 01:36 PM well yeah you will get some 01-Feb-20 01:36 PM The turbo will spin for a while too while powered off 01-Feb-20 01:36 PM What's the problem gating the foreline first? 01-Feb-20 01:36 PM if you can completely gate it off, directly at the foreline input, then you shooooould be fine 01-Feb-20 01:37 PM I guess the gated foreline would start to be pumped up in pressure by the turbo then? 01-Feb-20 01:37 PM yeah 01-Feb-20 01:37 PM Which isn't what the turbo likes 01-Feb-20 01:37 PM Hmm 01-Feb-20 01:37 PM HV gate seems like the best idea 01-Feb-20 01:37 PM But honestly I don't think the cressingto sputter coater (with drag turbo) even turns off the turbo or gates during argon purge 01-Feb-20 01:37 PM Maybe just purges slowly? 01-Feb-20 01:37 PM Unless the usage of a drag means it doesn't care about the gas load 01-Feb-20 01:39 PM a turbo+drag, or just drag? 01-Feb-20 01:39 PM The drag stage doesn't care as much about the gas load, but this is not true for the turbo stage 01-Feb-20 01:39 PM because drag pumps... don't care 01-Feb-20 01:39 PM Samy has a turbodrag 01-Feb-20 01:39 PM they can run in atmosphere just fine 01-Feb-20 01:39 PM It was an mdp5011 01-Feb-20 01:40 PM yeah that's fine 01-Feb-20 01:40 PM it will run in atmosphere 01-Feb-20 01:40 PM Ah so they just leave it on then during purge 01-Feb-20 01:40 PM I want a 5011 :( 01-Feb-20 01:41 PM 7.5 L/s though... 01-Feb-20 01:42 PM The sputter coater I'm referring to has a chamber that's probably less than a liter 01-Feb-20 01:42 PM it's still perfect for my application 01-Feb-20 01:42 PM Maybe it's a liter 01-Feb-20 01:42 PM tiny chamber, nixie 01-Feb-20 01:42 PM the 5011 is exactly what I want because I can crash it to atmosphere with shattered nixies and it would shrug it off 01-Feb-20 01:42 PM (angrily) 01-Feb-20 01:43 PM @Spirit I'm confused by the pic...here's attempt at labeling 01-Feb-20 01:43 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-781AB.png 01-Feb-20 01:43 PM H is your bell jar base 01-Feb-20 01:43 PM G is your turbo's flange 01-Feb-20 01:43 PM B is your centering ring and oring 01-Feb-20 01:43 PM turn it upside down 01-Feb-20 01:43 PM ah so D is TMP 01-Feb-20 01:44 PM yes 01-Feb-20 01:44 PM Yea 01-Feb-20 01:44 PM you just drill a precise ISO100 hole in your chamber, and holes for clamps 01-Feb-20 01:44 PM You don't need to do anything beyond drilling and tapping a 4 holes around a central hole on the aluminum plate 01-Feb-20 01:44 PM no need for an expensive adapter 01-Feb-20 01:44 PM and the chamber should then cover not only the TMP but also the screw? since i need space for inlets for gas, HV, etc 01-Feb-20 01:44 PM yes, you just need a big plate 01-Feb-20 01:45 PM k 01-Feb-20 01:45 PM look at how Ben Krasnow did it 01-Feb-20 01:45 PM do that, except with a turbo 01-Feb-20 01:46 PM That Midwest aluminum jig plate I linked is the cheapest source of pretty thick aluminum plates with a nice surface finish I can find 01-Feb-20 01:46 PM You need somewhere around 3/4" to 1" thick plate at least to make sure you have enough threads in the blind hole 01-Feb-20 01:53 PM ahh i did not realize that the turbo is so small...i hope my jar will work with that setup, let me measure and draw it out 01-Feb-20 01:53 PM ok thanks 01-Feb-20 01:54 PM 20 cm diameter bell jar is not that big, the ISO100 hole will take up most of that (~11cm) 01-Feb-20 01:54 PM But it's certainly doable depending on where you put the other feedthroughs 01-Feb-20 01:57 PM k 01-Feb-20 03:31 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_2020-02-01_15.30.51-4CF44.png 01-Feb-20 03:31 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_2020-02-01_15.30.44-9BE93.png 01-Feb-20 03:31 PM those bolt holes might be problematic...trying to leave room for other feedthroughs 01-Feb-20 03:31 PM just be aware that through holes are not what you want 01-Feb-20 03:31 PM ah so just halfway perhaps? 01-Feb-20 03:31 PM of course, you don't want them to go into the high vacuum side 01-Feb-20 03:31 PM they need to be blind 01-Feb-20 03:31 PM got it 01-Feb-20 03:32 PM Yeah that's why you need a fairly thick plate 01-Feb-20 03:32 PM assuming i have 3/4" plate what's a good length for the holes then, 1/2"? 01-Feb-20 03:32 PM looks like you have space for a good few KF16 ports 01-Feb-20 03:32 PM and yeah that should be alright 01-Feb-20 03:32 PM you will also only need 4 holes 01-Feb-20 03:32 PM 4 clamps is more than enough for an iso100 pump 01-Feb-20 03:34 PM k 01-Feb-20 03:34 PM and for options of attaching some feedthrough ports/attachments, assuming welding is best, but if i can't do that, is a threaded hole next best thing and to use vacuum grease+PTFE? guessing NPT threads are best? eg KF16->NPT attachment...since plate will be thick off the shelf KF16-NPT attachments wouldn't be tall enough to go in to get a nut+viton seal which i assume is also good 01-Feb-20 03:40 PM slotted thread + o-ring 01-Feb-20 03:40 PM but you can also cheat a bit and clamp KF16 directly to a precise hole 01-Feb-20 03:40 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-A50FA.png 01-Feb-20 03:40 PM just like on an MDP 5011 01-Feb-20 03:48 PM ahh cool 01-Feb-20 04:03 PM <__ice9#6039> Regarding reducing turbopump inlets down to smaller KF flanges, it isn't a huge penalty-- it does mean pumpdown will take proportionally longer and that final vacuum achieved may be slightly worse, but that's it. KF25 is pretty narrow, though. If you just want a hose to make it more mobile, KF40/KF50 baffles are still pretty manageable. KF100 baffles are rather less so. 01-Feb-20 04:20 PM ahh 01-Feb-20 04:20 PM with this design it means the magnets will need to be inside rather than outside, makes cooling a bit more complicated 01-Feb-20 04:31 PM Lots of turbos have 4.5" flanges and are routinely just connected to a KF25 tube, to pump down a system 01-Feb-20 04:31 PM But your pumping speed is basically limited the aperture effect when you shrink it 01-Feb-20 04:31 PM So for any gas load it's quite bad 01-Feb-20 04:37 PM I like the turbos with an interstage port, you can pump down two chambers at once! I can now run a KF25 bellow to whatever I want off the turbo on my SEM 01-Feb-20 04:37 PM Pumping speed is low but I'm patient 01-Feb-20 05:06 PM I am tempted to run 2 EXT255 in series via ISO100->KF25 adapter and see If I can reach 5E-10 I see that manual does not advice low inlet pressure due to turbo oil evaporation, but hopefully for short run it's not that deadly. 01-Feb-20 05:07 PM your ultimate pressure only depends on your inlet seal 01-Feb-20 05:07 PM KF/ISO won't reach -10 01-Feb-20 05:10 PM But turbo has limited compression, so you can only go from 5E-10 to 5E-2 (fore-vacuum) pressure with typical 1E8 nitrogen compression? Or it does not work like that? 01-Feb-20 05:11 PM it will still get to -10 if you have a metal to metal seal 01-Feb-20 05:11 PM otherwise UHV turbos simply wouldn't work 01-Feb-20 05:11 PM but you're still unlikely to reach -10 with just a turbo, that's UHV pump territory 01-Feb-20 05:27 PM <__ice9#6039> wonder what the simplest kind of UHV pump is. probably titanium sublimation-- just a titanium wire and a feed-through to a decent constant current PSU on a timer loop 01-Feb-20 05:27 PM yup 01-Feb-20 05:29 PM <__ice9#6039> non-evaporable getter pumps seem to usually use more complex alloy materials or powder blends, but might also be a contender. crucible of metal powder with an electrically insulated heating element stuck in it 01-Feb-20 05:29 PM <__ice9#6039> Of course neither one works on noble gases, but they handle H2 and CO coming in through the stainless steel walls 01-Feb-20 05:29 PM <__ice9#6039> Ion pumps seem to require a lot of fabrication, cryopumps and turbopumps obviously must be purchased 01-Feb-20 05:55 PM You hit -10 pretty easily if you have turbos in series 01-Feb-20 05:55 PM like if your fv is -3, it doesn't take that much of a turbo to hit -10 with a simple clean baked chamber 01-Feb-20 06:12 PM you'd suck all the oil out of turbo #1 though 01-Feb-20 06:17 PM ? 01-Feb-20 06:18 PM remember that turbo oil still has a vapor pressure 01-Feb-20 06:18 PM Yes 01-Feb-20 06:18 PM Turbos are connected in series all the time 01-Feb-20 06:18 PM if you back turbo #1 down at like 1*10^-6 or even lower(which you will inevitably reach, they're turbos after all), you'll just start evaporating oil from it 01-Feb-20 06:19 PM Good reason to do it intelligently then 01-Feb-20 06:19 PM UHV turbos usually have a holweck stage on them anyway 01-Feb-20 06:19 PM so you don't need to series them 01-Feb-20 06:21 PM Depending on the gas 01-Feb-20 06:21 PM afaik drag stages are less discriminatory 01-Feb-20 06:22 PM How much do gas-specific compression ratios of roughing pumps vary? 01-Feb-20 06:22 PM less than turbos but they do 01-Feb-20 06:24 PM Because some of the 10^11 N2 compression ratio pumps only have like 10^8 for helium 01-Feb-20 06:24 PM so I could see wanting to push that a bit further 01-Feb-20 06:24 PM IDK I mostly see turbos in parallel rather than series 01-Feb-20 06:24 PM Most of my vacuum info comes from reading theses that gloss over it rather than proper instruction, so I guess all I can say is many people have done it. not that it's a good idea 01-Feb-20 06:24 PM But like that 2200 iPL has an ultimate pressure of -10, with a compression ratio of 10^4 01-Feb-20 06:24 PM you have to back it with a turbo to get anywhere 01-Feb-20 06:29 PM it's a huge maglev turbo 01-Feb-20 06:29 PM Helium is probably the only gas you'd consider doing this for, too 01-Feb-20 06:29 PM tldr; if your manual says don't do it, don't do it 01-Feb-20 06:54 PM @Spirit i wonder if it is possible to make a (weak) spring loaded valve that could be pulled shut before any damage was done to a turbo with the nixie stuff you have planned? 01-Feb-20 06:55 PM No, but emergency anti-death valves exist, for the low low price of your house 01-Feb-20 06:55 PM thats why i was suggesting to find a way to make one 01-Feb-20 06:56 PM Considered using a diffusion pump? @Spirit 01-Feb-20 06:56 PM I have one on sale 01-Feb-20 06:56 PM Same deal as the turbo, except you get an explosion and your chamber is covered in oil 01-Feb-20 06:56 PM The pump doesn't die, but other things may or may not, and you have to spend hours cleaning everything 01-Feb-20 06:56 PM Just low-balled a seller... for $50. 01-Feb-20 06:56 PM Albeit for a dead pump, doesn't spin freely, but at 27krpm I can put pretty much any high speed bearing into it 01-Feb-20 06:56 PM I highly doubt they'll accept 01-Feb-20 06:59 PM makes sense to me, good luck! 01-Feb-20 07:01 PM thanks 01-Feb-20 07:04 PM <__ice9#6039> Lollll 01-Feb-20 07:04 PM <__ice9#6039> Hmm anyway for helium consider an ion pump instead 01-Feb-20 07:04 PM <__ice9#6039> Cryopumps and getter pumps can't touch it, turbopumps work but at worse efficiency because of its ridiculous molecular speed distribution 01-Feb-20 07:12 PM It is also possible that the seals on the drag stage actually seized on the housing so the blades won't turn, the bearing may not be the only thing bad here 01-Feb-20 07:12 PM there are no seals 01-Feb-20 07:12 PM just tight tolerance spinny bit and orings for critical parts 01-Feb-20 07:13 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-0CA43.png 01-Feb-20 07:13 PM Well anything could get into that tight tolerance spinny bit and cause the entire pump to crash 01-Feb-20 07:13 PM Shouldn't take a big particle 01-Feb-20 07:13 PM yup :< 01-Feb-20 07:13 PM but hopefully repairable 01-Feb-20 07:14 PM But best of luck anyway! 01-Feb-20 07:14 PM I'll trade for a regular turbo too(with a brain), but I have a feeling it's going to be a temporary turbo, to be blade salad eventually 01-Feb-20 07:14 PM and that makes me sad 01-Feb-20 07:20 PM <__ice9#6039> What is the problem with just using thick quartz glass? 01-Feb-20 07:20 PM <__ice9#6039> It's pretty difficult to shatter 01-Feb-20 07:20 PM this isn't for a viewport 01-Feb-20 07:20 PM it's for making nixies 01-Feb-20 07:20 PM <__ice9#6039> And a lot cheaper than a pump 01-Feb-20 07:20 PM which will eventually shatter 01-Feb-20 07:21 PM <__ice9#6039> Hmm ok but-- is that mostly a gas venting issue or a debris issue? 01-Feb-20 07:21 PM both 01-Feb-20 07:21 PM more towards the sudden atmospheric vent 01-Feb-20 07:22 PM <__ice9#6039> Why would an entire chamber vent to atmosphere if a Nixie tube breaks inside the chamber? I don't really understand. 01-Feb-20 07:22 PM <__ice9#6039> I do not know very much about the process 01-Feb-20 07:22 PM not inside, it's going to be connected externally through a pumpdown port 01-Feb-20 07:22 PM think ion gauge shattering 01-Feb-20 07:22 PM <__ice9#6039> Huh I see 01-Feb-20 07:22 PM <__ice9#6039> Yeah I don't use glass ones for that reason 01-Feb-20 07:22 PM <__ice9#6039> That seems like a tricky problem. Makes me wonder how it was done in industry historically. 01-Feb-20 07:24 PM diffpumps, practice, and lots of cleanup 01-Feb-20 07:24 PM <__ice9#6039> Maybe just use a resistive heater in vacuum 01-Feb-20 07:24 PM once the process is nailed down, they don't really shatter often at the high vacuum stage 01-Feb-20 07:24 PM <__ice9#6039> Yeah it does sound like a job for a diffusion pump 01-Feb-20 07:25 PM Use silicone oil in the diff pumps too 01-Feb-20 07:26 PM yeah, just not really viable for prototyping cheap and quickly 01-Feb-20 07:26 PM I'm not aware of any other simple solutions for a high vacuum system that survives venting from high vac to atmosphere in milliseconds 01-Feb-20 07:26 PM well, cheap too 01-Feb-20 07:26 PM I mean the prices for silicone oils are not that bad 01-Feb-20 07:27 PM it'd still explode 01-Feb-20 07:27 PM just in a more friendly way 01-Feb-20 07:27 PM <__ice9#6039> Not with fire 01-Feb-20 07:27 PM You'd end up with a mess no matter what 01-Feb-20 07:27 PM <__ice9#6039> Just oil 01-Feb-20 07:27 PM <__ice9#6039> Yes 01-Feb-20 07:27 PM if a nixie shatters it won't be a big mess 01-Feb-20 07:27 PM since the evac tubes are generally tiny, and those are robust 01-Feb-20 07:27 PM it's the bulb that would shatter 01-Feb-20 07:28 PM <__ice9#6039> Hmm I assume there is a valve that closes in the chamber after pumpdown but before sealing/filling the tube? So breakage only harms the pump if it occurs during the actual pumpdown? 01-Feb-20 07:28 PM yes 01-Feb-20 07:28 PM but the actual pumpdown involves many stressful(for the bulb) steps, like induction heating the contents of the bulb, baking the entire bulb in a kiln 01-Feb-20 07:30 PM <__ice9#6039> Why not do that with the valve closed? 01-Feb-20 07:30 PM <__ice9#6039> Pump, close, heat, open, pump, close, bake, open, 01-Feb-20 07:30 PM because it'd recondense/reabsorb right back into the bulb/contents 01-Feb-20 07:30 PM <__ice9#6039> Not instantly 01-Feb-20 07:31 PM more stress if you jerk the valve open and closed 01-Feb-20 07:31 PM <__ice9#6039> I don't mean allow it to cool 01-Feb-20 07:31 PM <__ice9#6039> Well that's true 01-Feb-20 07:31 PM it needs to be baked for a while 01-Feb-20 07:31 PM maybe 20-30 minutes, while under high vacuum 01-Feb-20 07:31 PM What kind of pumping speed do you need? 01-Feb-20 07:31 PM any 01-Feb-20 07:31 PM hence why the 5011 works 01-Feb-20 07:31 PM Can’t you just heavily throttle it? 01-Feb-20 07:32 PM <__ice9#6039> Yes but it's most likely to break during the temperature change rather than once it is at temp 01-Feb-20 07:32 PM a pinhole that vents to atmosphere will still immediately destroy a turbopump @idmb 01-Feb-20 07:32 PM Like make the turbo pump through a 0.25mm hole or something 01-Feb-20 07:32 PM Subsequent 0.25mm holes 01-Feb-20 07:32 PM that's irrelevant 01-Feb-20 07:32 PM That's still not going to help, atmosphere will reach the pump way too fast 01-Feb-20 07:32 PM <__ice9#6039> My turbo is rated for atmosphere at 50% rotational speed fwiw 01-Feb-20 07:32 PM also a bit insane, I'm not looking to pump a single tube for weeks 01-Feb-20 07:32 PM at a few ml/s pumping rate lol 01-Feb-20 07:33 PM <__ice9#6039> Lol yes 01-Feb-20 07:33 PM <__ice9#6039> No idea whether it does enough when running that slowly though. Likely not. So limited practical significance 01-Feb-20 07:33 PM the issue with even 50% in atmosphere is that it doesn't translate to catastrophic venting 01-Feb-20 07:34 PM <__ice9#6039> The manual literally says you can manually vent at 50% 01-Feb-20 07:34 PM if it goes from 0%(effectively) to 10% in 100ms, the pump turns into salad regardless 01-Feb-20 07:34 PM <__ice9#6039> It also says you can use a leakage valve at 100% 01-Feb-20 07:34 PM which pump is it? 01-Feb-20 07:34 PM You can run pumps at lower than nominal 01-Feb-20 07:34 PM <__ice9#6039> But that kind is automated 01-Feb-20 07:34 PM you can, down to a certain point @idmb 01-Feb-20 07:34 PM The blades need to have speeds close to the speed of the molecules to have effective momentum transfer to pump, so at 50% speed you get much less than 50% pumping speed 01-Feb-20 07:34 PM ^^^^ very much that 01-Feb-20 07:34 PM at 50% speed you might not even get any pumping at all 01-Feb-20 07:34 PM Compression ratio too 01-Feb-20 07:35 PM it'd act closer to a roots blower than a turbo 01-Feb-20 07:35 PM this is why the MDP 5011/10 is great 01-Feb-20 07:35 PM you can spin it right up to 27krpm in atmosphere and it won't care 01-Feb-20 07:35 PM as long as it doesn't eat a housefly or something 01-Feb-20 07:35 PM <__ice9#6039> BOC Edwards EXT 255Hi 01-Feb-20 07:35 PM ah, an EXT 01-Feb-20 07:35 PM yeah I was considering getting one, even talked to Mason about his 01-Feb-20 07:35 PM but they're... turbos 01-Feb-20 07:36 PM Already sold, but I have one more 01-Feb-20 07:36 PM yup, the one I considered is now going to samy 01-Feb-20 07:36 PM probably for the better 01-Feb-20 07:37 PM Just buy the tools to make your own drag pump. 01-Feb-20 07:37 PM <__ice9#6039> Hahahaha 01-Feb-20 07:37 PM Easy. 01-Feb-20 07:37 PM said the PhD student :^) 01-Feb-20 07:37 PM Haha 01-Feb-20 07:37 PM I actually make things that spin 01-Feb-20 07:37 PM Way faster than turbos 01-Feb-20 07:38 PM if I had the money to buy a state of the art 5 axis machining center, a dynamic balancer, and about $5k worth of stock, I'd be making all my hardware 01-Feb-20 07:38 PM oh, and a building with a thermally controlled room with meter thick floors 01-Feb-20 07:38 PM don't want someone standing next to the machine radiating you out of spec 01-Feb-20 07:54 PM another grad student actually built their own 5 axis cnc 01-Feb-20 07:54 PM oh I totally could build one too, but it wouldn't come near the spec needed to make efficient turbos or drags 01-Feb-20 07:54 PM they can almost make seemingly circular 1" holes in aluminum now, 3 years lated -_- 01-Feb-20 07:54 PM and by "seemingly circular," I mean getting a nice tight fit with 1" optical posts 01-Feb-20 07:54 PM So, what happens to a cryopump/cryocooler if the chamber suddenly goes to atmosphere? 01-Feb-20 07:58 PM it gets icy 01-Feb-20 07:58 PM that'd be the solution for me 01-Feb-20 07:58 PM sadly those are even more ridiculously expensive 01-Feb-20 07:58 PM what are you actually pumping? 01-Feb-20 07:59 PM air 01-Feb-20 07:59 PM and crap that sits inside glass/metal electrodes 01-Feb-20 07:59 PM ah, so you can't just LN2 it 01-Feb-20 08:00 PM I can, that's pretty much what cryopumps do 01-Feb-20 08:00 PM but LN2 is expensive and I'd still need to improvise a cold head 01-Feb-20 08:00 PM LN2 doesn't pump air 01-Feb-20 08:00 PM it does if your pump is at ln2 temps 01-Feb-20 08:00 PM it won't pump He, that's about it 01-Feb-20 08:01 PM What? 01-Feb-20 08:02 PM if your cooler is at LN2 temp, it will condense ln2 01-Feb-20 08:03 PM so we use stuff like this: 01-Feb-20 08:03 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screen_Shot_2020-02-01_at_8.03.02_PM-8800A.png 01-Feb-20 08:03 PM where it's just an in-vacuum reservoir of LN2 01-Feb-20 08:03 PM yeah, that's essentially what I'd build 01-Feb-20 08:03 PM but LN2 is expensive here and I'd need to also buy a dewar 01-Feb-20 08:03 PM as measured on our QMS/RGA, they barely affect N2 and O2 partial pressures 01-Feb-20 08:03 PM in high vacuum you need something like 50k to do so 01-Feb-20 08:04 PM most cryopumps will reach that 01-Feb-20 08:04 PM Helium ones yeah 01-Feb-20 08:09 PM Sadly the pumps alone are many hundreds to thousands, then you need a compressor, expensive hoses and fill 01-Feb-20 08:11 PM used. 01-Feb-20 08:11 PM New they're even more 01-Feb-20 08:11 PM oh yeah of course 01-Feb-20 08:11 PM Ok well that was obvious haha, I meant that they scale much higher than turbos seem to 01-Feb-20 08:11 PM like a 10k turbo is what, $500-1500 used? But a 30k cryopump is ~2k used. 01-Feb-20 08:12 PM 10k? 01-Feb-20 08:12 PM oh yeah dollars 01-Feb-20 08:12 PM yes 01-Feb-20 08:12 PM The cryo/vacuum specialist in our tech shop said he would never consider a used cryopump 01-Feb-20 08:12 PM Kinda like buying used GPUs from bitcoin mining 01-Feb-20 08:12 PM They're apparently used mostly for very harsh processes? 01-Feb-20 08:13 PM semicon, yeah 01-Feb-20 08:13 PM That's true for almost all used high tech equipment though, you take a risk and you hope to get a good deal 01-Feb-20 08:13 PM you can see that a lot of cryopumps on ebay look horrid inside 01-Feb-20 08:13 PM but brand new outside 01-Feb-20 08:15 PM I think used helium compressors are pretty solid 01-Feb-20 08:15 PM yeah, but often 3ph and >3kw 01-Feb-20 08:15 PM which are ~half the cost 01-Feb-20 08:15 PM A lot need like 5LPM to cool them too 01-Feb-20 08:22 PM At least they're mechanically approachable by mortals though (re used cryo units being often clapped out) 01-Feb-20 09:05 PM @idmb on your molecular jet project what did you use for your metering mechanism? 01-Feb-20 09:08 PM metering? 01-Feb-20 09:10 PM droplet generator I suppose 01-Feb-20 09:10 PM RDK 408D2 cryocooler with a 5um SEM aperture on the tip 01-Feb-20 09:11 PM I'm imagining a pulsed molecular beam from what you had described in the intro channel 01-Feb-20 09:11 PM gotcha, I was imagining more of a mechanical situation with external gas feed sort of deal 01-Feb-20 09:11 PM nah it's just a block of copper attached to the cryocooler with a 1/8" swagelok connection, a 0.5um stainless steel gas filter, and then an SEM aperture the helium flows out of 01-Feb-20 09:11 PM My droplets are on the order of ~1000s of helium atoms 01-Feb-20 10:54 PM Whoa, this is interesting 01-Feb-20 10:54 PM I just got a quote from a Chinese manufacturer about wire bonders 01-Feb-20 10:54 PM A semiautomatic gold thermosonic ball bonder with heated stage is $4300 + shipping(~$450) 01-Feb-20 10:54 PM That is... surprisingly affordable, as far as bonders go anyway 01-Feb-20 10:54 PM Heaps cheaper than eBay deals! 02-Feb-20 05:20 AM Well after going through the parts list and exploded diagram with some sharpies and double checking it I finally have all the bits from my rebuild kit back in the pump. It's almost completely back together. It's still sitting unfinished though until I get that little bit of spring steel valve replacement... Kinda a shame it's not included in the rebuild kit considering it rusted through and the rest of the pump is in decent shape still. 02-Feb-20 05:20 AM So yea.. Looks like a major rebuild kit would have included that and the vanes... That's all the extra it would have included... Considering this plate is 10 bucks the vanes then cost 200 dollars according to the minor vs major math... 02-Feb-20 05:44 AM er actually its not that bad on these leybolds... its only 90 bucks more for the major... 90 for the minor and 180 for the major 02-Feb-20 05:44 AM alcatel goes from 74 bucks minor to 226 major... 02-Feb-20 05:44 AM for the 2008A anyway 02-Feb-20 05:44 AM So yea, really kinda taking preference to these leybolds, and now that I have gone through one... outside of a really silly alignment pin thing which can kinda be avoided, its a pretty simple rebuild. They are nice and quiet. They are cheap to rebuild. 02-Feb-20 05:44 AM The whole thing with the pins is they use them for alignment between the stage housings and plates and such... To take it apart they tell you to use a driving pin or a "long bolt" and carefully using a hammer to drive those pins straight through, on the smaller pumps this means one pin into another into another until you get all 3 pins in a row out on both sides... like ugh why... I personally just used a plastic/brass hammer (little thing) to tap it apart, the pins didn't even really shift, just whichever side it was loosest on it slid out and stayed with the other side. just being careful to try and tap on the housing/surfaces not where orings sit, although its not too big of a deal using the brass hammer anyway since it shouldn't damage the steel, just have to make sure you wipe it down good after to be sure you didn't get any brass left behind. If your doing a major rebuild you should be ultrasonicating everything anyway so not a big deal. 02-Feb-20 06:47 AM @Spirit Link to the bonder model / manufacturer please? 02-Feb-20 07:28 AM <__ice9#6039> @Spirit you can supercool LN2 by pulling a partial vacuum on it and then venting back to atmospheric pressure. you get some very unsettling perfectly-still non-boiling LN2. 02-Feb-20 07:28 AM <__ice9#6039> The result will passively condense air against a copper cold-finger pass-through, including the nitrogen 02-Feb-20 07:28 AM <__ice9#6039> But not neon/H2 02-Feb-20 07:28 AM <__ice9#6039> Like a proper He cryocooler 02-Feb-20 09:07 AM @ZeptoBars minder-hightech.com 02-Feb-20 09:07 AM email minder@minder-hightech.com, ask for MDBB-1750 02-Feb-20 09:18 AM Good point ice 02-Feb-20 09:18 AM I forgot that that was how they made extra cold LHE 02-Feb-20 09:48 AM I see Ben Krasnow has his rotary vane connected to both his TMP and chamber - do i need to do that as well or can i just go mechanical->TMP->chamber? 02-Feb-20 09:49 AM depends on the size of the chamber, turbos don't like huge amounts of air through them 02-Feb-20 09:50 AM ah 02-Feb-20 09:50 AM Roughing your chamber through the turbo is fine 02-Feb-20 09:50 AM Your belljar is much smaller than Ben's 02-Feb-20 09:50 AM I think some older ones don't like that / advise against it 02-Feb-20 09:50 AM but usually you would only do that with a gate valve on the turbo as some sort of load-lock where you didn't want to turn off the turbo 02-Feb-20 09:53 AM <__ice9#6039> I have pumped a 160L chamber though the turbo before, but mainly because I didn't own any decent valves at the time. It will stay cleaner with a selector valve. 02-Feb-20 09:55 AM and when people say you shouldn't start a TMP up in atmosphere, do they mean the inlet or the outlet or both? 02-Feb-20 09:55 AM Both 02-Feb-20 09:55 AM Both, unless yours specifically says either is ok 02-Feb-20 09:56 AM got it 02-Feb-20 09:56 AM which it never will @idmb 02-Feb-20 09:57 AM It's okay to spin most turbos up in atmosphere for a few seconds to test it, but that's it 02-Feb-20 09:57 AM I swear some are OK with it 02-Feb-20 09:57 AM http://www.hakuto-vacuum.jp/pfeiffer_vacuum/pdf/DryPump/OnToolBooster150.pdf 02-Feb-20 09:57 AM Is that a turbo? IDK. It's advertised as one. 02-Feb-20 09:59 AM no, it's not a turbopump 02-Feb-20 09:59 AM not in the conventional sense 02-Feb-20 09:59 AM it's closer to what the EPX series from Edwards is 02-Feb-20 09:59 AM basically a giant, super overbuilt, and really overdriven multistage turbine pump 02-Feb-20 09:59 AM consumes up to 2kW and only takes 25 seconds to get up to 60krpm 02-Feb-20 09:59 AM and needs nearly 3l/min to cool it 02-Feb-20 10:00 AM that's pretty typical peak power 02-Feb-20 10:01 AM 1.8kw is continuous 02-Feb-20 10:01 AM IDK what yours are like, even mine that are a handful of watts at full speed have a big startup power 02-Feb-20 10:01 AM Oh lol 02-Feb-20 10:01 AM yeah it's not really a turbo 02-Feb-20 10:01 AM I have never seen a turbo with 2 kW starting power though 02-Feb-20 10:01 AM works on the same principle, sort of, but ridiculously overbuilt to run in atmosphere, and much lower ultimate pressure 02-Feb-20 10:01 AM @Mason_Yu bucket-sized turbos have around that 02-Feb-20 10:02 AM Mine only takes 200W and it's larger than a 5gal bucket 02-Feb-20 10:02 AM https://www.ebay.com/itm/EPX-TWIN-180L-Edwards-A419-61-222-High-Vacuum-Dry-Pump-Used-Tested-Working/173561695957 02-Feb-20 10:02 AM this is essentially what that booster is 02-Feb-20 10:02 AM https://www.ebay.com/itm/Boc-Edwards-EPX180L-Pump-Vacuum-A419-41-214-Turbo/143379301071 02-Feb-20 10:02 AM they get cheaper too. 02-Feb-20 10:02 AM but water cooling is mandatory and most of them are 3ph 400v 02-Feb-20 10:02 AM only goes to 7*10^-5 torr 02-Feb-20 10:06 AM Watercooling isn’t that mandatory 02-Feb-20 10:06 AM it is. 02-Feb-20 10:06 AM Usually the part they’re cooling is exposed 02-Feb-20 10:06 AM for these pumps water cooling is mandatory 02-Feb-20 10:06 AM they're dumping 1.8kw into vacuum 02-Feb-20 10:07 AM No? The hot parts are in direct thermal contact with atmosphere 02-Feb-20 10:07 AM nope 02-Feb-20 10:07 AM You can strap a large fan to it instead 02-Feb-20 10:07 AM absolutely not 02-Feb-20 10:07 AM these are a separate type of pump that require water cooling 02-Feb-20 10:07 AM The water loop is often just around the back? 02-Feb-20 10:08 AM not here 02-Feb-20 10:08 AM I guess these are different then 02-Feb-20 10:08 AM this is a pump that just eats raw power and outputs nothingness 02-Feb-20 10:08 AM But lots of “water-cooling only” pumps just do that because the fan power needed is ugly and annoyingly loud 02-Feb-20 10:08 AM Save your power bill by getting this 1.4 kW pump for your everyday high vacuum needs! 02-Feb-20 10:08 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-6B538.png 02-Feb-20 10:08 AM a very brute force solution 02-Feb-20 10:08 AM also, this is neat 02-Feb-20 10:08 AM https://www.idealvac.com/6x6x6-Cubic-Modular-Vacuum-Chamber/pp/P109139 02-Feb-20 10:08 AM and... surprisingly affordable! 02-Feb-20 10:08 AM although I'd get a bigger kit 02-Feb-20 10:08 AM https://www.idealvac.com/9x9x9-Cubic-Modular-Vacuum-Chamber/pp/P1010002 02-Feb-20 10:08 AM this looks awesome 02-Feb-20 10:08 AM I wonder if you can bolt the cubes to each other 02-Feb-20 10:11 AM Yes you can! 02-Feb-20 10:11 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-9184D.png 02-Feb-20 10:12 AM that is super neat 02-Feb-20 10:13 AM flat-sided vacuum chambers make me uncomfortable 02-Feb-20 10:13 AM it's only 1 bar 02-Feb-20 10:14 AM And it's tiny 02-Feb-20 10:14 AM we have some homemade cubes that are remarkably similar 02-Feb-20 10:14 AM made from brass though 02-Feb-20 10:15 AM Since everything on this cube is sealed with viton it is actually not that hard to make (if you have a CNC) 02-Feb-20 10:15 AM The cube frame needs to be machined from a single cube of stock but for small stuff it's okay 02-Feb-20 10:15 AM Guess that's why they can sell this for a reasonable cost 02-Feb-20 10:19 AM You also save most of that cut-away stock 02-Feb-20 10:19 AM if you had 9" thick sheet, you could just waterjet out the ID and still have a ~7"x7"x9" piece of leftover 02-Feb-20 10:19 AM I've seen a 2'x3'x1' chamber that was milled from a single piece of aluminum, where 5/6 walls were solid. 02-Feb-20 10:19 AM For that they had 90% scrap --- 02-Feb-20 10:27 AM wow I did not realize there was a company working on proton-boron fusion in my area... thats kinda cool 02-Feb-20 10:27 AM i wonder if they would let me check out their dumpsters 02-Feb-20 10:28 AM TAE? 02-Feb-20 10:29 AM https://tae.com/ 02-Feb-20 10:29 AM yeah 02-Feb-20 10:31 AM Their actual neutron yield from DD fusion is actually really really low 02-Feb-20 10:31 AM unfortunately based on a quick check of streetview all their dumpsters are behind gates in a parking lot covered in private property signs so i would definitely need direct permission 02-Feb-20 10:31 AM their modular vacuum lego is neat 02-Feb-20 10:32 AM They sure do have a heck of a lot of money behind them, but it looks like they are tackling way too many idealized concepts without putting in the engineering work on the core fusion side of things 02-Feb-20 10:32 AM but it's not the xhv-ish part of uhv 02-Feb-20 10:32 AM They are now trying to "diversify" to healthcare and so on 02-Feb-20 10:33 AM humans are always sick - diversify! 02-Feb-20 10:33 AM i think, on my very basic understanding of their goals (just learned of them this morning), they are trying to blow through as many test configurations as possible in as short a time as they can 02-Feb-20 10:33 AM Also, 400 eV electron temperture is the highest record? 02-Feb-20 10:33 AM That's really low 02-Feb-20 10:33 AM yeah seems like a good way to spend other people's money not getting a lot of returns 02-Feb-20 10:34 AM With 30 ms confinement time lol 02-Feb-20 10:34 AM .o( vacuum coffins ) 02-Feb-20 10:34 AM i would hope if someone gave ME $600M i would get a bit better results than that 02-Feb-20 10:34 AM That's probably the lowest triple product among all the decent sized fusion startups 02-Feb-20 10:34 AM @Mason_Yu beat it! 02-Feb-20 10:34 AM A DPF will beat this and has beaten it 02-Feb-20 10:34 AM ok! 02-Feb-20 10:35 AM proton-boron fusion is one of the more demanding kinds right? maybe if they switched up fuel cycles they would have better results 02-Feb-20 10:35 AM I found a box of data from the general fusion CEO's phd 02-Feb-20 10:35 AM Like Eric Lerner in his little storage garage in New Jersey with crowdfunded DPF has achieved 10^12 neutrons per shot, and they are looking to do p-B11 fusion 02-Feb-20 10:35 AM think their goal is to minimize the neutron yield 02-Feb-20 10:35 AM Well you need a hot enough plasma to ignite p-B11 in the first place 02-Feb-20 10:35 AM They don't have that temperature yet, so aneutronic fusion doesn't play any roles 02-Feb-20 10:36 AM ahh that is all just aspirational on their part then? 02-Feb-20 10:36 AM ah tae is the topic 02-Feb-20 10:36 AM i have not dug into what milestones they have actually achieved yet 02-Feb-20 10:36 AM It's their ultimate goal, but you can't beat physics with dreams 02-Feb-20 10:37 AM you all want to be called norman 02-Feb-20 10:37 AM haha 02-Feb-20 10:37 AM i just want norman's scraps 02-Feb-20 10:37 AM :)) 02-Feb-20 10:37 AM Well me too! Eventually some of TAE's projects will be scraped and I want to go through their surplus auction 02-Feb-20 10:37 AM :3 02-Feb-20 10:38 AM not if i get there first 02-Feb-20 10:38 AM I guess it would be more like delorean 02-Feb-20 10:38 AM but really i think they probably must have a ton of scrapped smaller iterations... 02-Feb-20 10:38 AM have not seen much current vacuum hardware going up for sale locally so maybe it is all just sitting in the warehouse 02-Feb-20 10:39 AM everything/one ends down the docks 02-Feb-20 12:37 PM Seems very likely there's scrap. New, custom chambers are often ~the same price as standard parts. That leads to a lot of designs that aren't convenient for future iterations 02-Feb-20 01:06 PM I've been lowballing turbo and drag sellers on ebay with ridiculous offers 02-Feb-20 01:06 PM It'd be funny if some of them accept the 90% off offers I'm sending 02-Feb-20 01:06 PM and also very good 02-Feb-20 01:07 PM A lot of them set minimum offers they'd consider 02-Feb-20 01:08 PM none of them have been auto-rejected 02-Feb-20 01:09 PM how interested are you in pumps that are deemed "broken & not worth repairing" ? 02-Feb-20 01:09 PM depends on the kind and how they're broken 02-Feb-20 01:09 PM I'm not paying to ship turbo salad overseas 02-Feb-20 01:09 PM what about from uk? 02-Feb-20 01:10 PM anywhere, really 02-Feb-20 01:10 PM turbo salad is simply not worth repairing 02-Feb-20 01:11 PM I'm unsure about customs charges for shipping from UK. 02-Feb-20 01:11 PM EU sources, especially Germany would be preferable for me 02-Feb-20 01:11 PM Germany has awesomely cheap shipping. 02-Feb-20 01:13 PM IDK what's salad. we have a big seiko maglev with controller with a label that just says "broken" 02-Feb-20 01:13 PM how free is it 02-Feb-20 01:13 PM :P 02-Feb-20 01:13 PM I think it's like 25kg so probably not free enough 02-Feb-20 01:14 PM well, if it's a maglev that hasn't been crashed, it's likely the controller that is fried 02-Feb-20 01:14 PM and I can repair that 02-Feb-20 01:14 PM I've been pushing hard that getting rid of "ok" stuff to make the "good" stuff more accessible is worth it 02-Feb-20 01:14 PM though I'm not sure what happens when a maglev turbo's controller dies while it's spinning 02-Feb-20 01:14 PM realistically speaking, how much would you want for it? 02-Feb-20 01:14 PM shipping 25kg to Belarus would be a pain 02-Feb-20 01:15 PM Not just the shipping, the hassle of packaging/crating it up 02-Feb-20 01:16 PM if it goes in a crate it's probably prohibitively expensive to ship 02-Feb-20 01:16 PM 25kg 02-Feb-20 01:16 PM well we can't actually sell it, it would just be shipping 02-Feb-20 01:16 PM hmmm 02-Feb-20 01:16 PM which model is it? 02-Feb-20 01:16 PM parcelforce says it's around £110-120 to me, which is super reasonable 02-Feb-20 01:17 PM IDK I can check this week. I think it's a ~20-30 year old ~800-1200 L/s with either ISO or CF8"/10" 02-Feb-20 01:17 PM controller is a 4U beast 02-Feb-20 01:18 PM oh wait, there's also the controller 02-Feb-20 01:18 PM ... any smaller pumps that aren't monsters? :P 02-Feb-20 01:18 PM nah all the smaller ones are pfeiffer/leybold/edwards and actually worth paying for repairs 02-Feb-20 01:18 PM as much as I'd love for my entire chamber to get to -7 in 30 seconds, it's also huge 02-Feb-20 01:19 PM just gotta be patient, Spirit 02-Feb-20 01:19 PM the spinup time is like 15-30 min in my experience 02-Feb-20 01:19 PM well yeah, aside from that :P 02-Feb-20 01:20 PM i got my turbo (that ended up needing a bearing and hall sensors) for $40+$10 shipping...and the seller felt bad the bearing disassembled itself in transit and refunded me the $40 02-Feb-20 01:20 PM without asking 02-Feb-20 01:20 PM what about broken alcatel rotary vanes? does anyone want those? 02-Feb-20 01:20 PM so if you are patient there are deals to be had 02-Feb-20 01:20 PM last I checked there was a pallet of them in line for the dump 02-Feb-20 01:20 PM didn't I send you the $40 turbo link? @LRM 02-Feb-20 01:20 PM :P 02-Feb-20 01:21 PM dont think so? think that was before i was invited here 02-Feb-20 01:21 PM ah 02-Feb-20 01:22 PM @idmb how broken? 02-Feb-20 01:22 PM last I checked there was a pallet of them in line for the dump @idmb .... 02-Feb-20 01:22 PM the only maglev seikos I can find are the STP 300H 02-Feb-20 01:22 PM Yeah how broken? 02-Feb-20 01:23 PM from a pallet you can almost certainly get a couple solid working pumps out of the parts at the very least 02-Feb-20 01:23 PM unless someone went on a serial pump destruction spree 02-Feb-20 01:23 PM i have heard that you can refinish the vanes on them pretty easily if they are not actually worn away 02-Feb-20 01:23 PM I think this is the mech shop clearing out their storage 02-Feb-20 01:23 PM where they just slowly collected pumps from labs where they got replaced 02-Feb-20 01:23 PM sometimes people suck in abrasive stuff and tear a chunk out of an edge 02-Feb-20 01:23 PM but the pumps are otherwise fine aside from like 1 little chip on the vane 02-Feb-20 01:25 PM Do let us know about all the broken pumps :P 02-Feb-20 01:25 PM side note: seiko pumps became edwards pumps 02-Feb-20 01:26 PM the viability of them might also depend on just how old they are...if they were used with mercury diffusion systems please send them to the dump (or hazardous waste) 02-Feb-20 01:26 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-7F8D0.jpg 02-Feb-20 01:26 PM the broken one is the one on the yellow circle 02-Feb-20 01:27 PM oh, that is vintage 02-Feb-20 01:27 PM and conflat 02-Feb-20 01:27 PM if that helps identify 02-Feb-20 01:27 PM it looks almost like the old STPA pumps 02-Feb-20 01:28 PM older than 30? 02-Feb-20 01:28 PM 1983 to present 02-Feb-20 01:28 PM looks like an STPA1303 02-Feb-20 01:28 PM https://shop.edwardsvacuum.com/products/b71802020/view.aspx 02-Feb-20 01:29 PM this is some of the scrap 02-Feb-20 01:29 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/53340214_315875712335968_63568864852700037-CA2B1.png 02-Feb-20 01:29 PM even trail mix has been scrapped 02-Feb-20 01:29 PM IDK there's always a pile of stuff like that, it cycles every couple weeks 02-Feb-20 01:29 PM oh, on that note 02-Feb-20 01:29 PM definitely still a few welch pumps aroudn 02-Feb-20 01:30 PM any ulvac rotary vanes? 02-Feb-20 01:30 PM they are stupidly quiet and I really want one 02-Feb-20 01:30 PM these are still around I believe, stored indoors even 02-Feb-20 01:30 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/50690217_316114495776674_56686915832355225-7FB62.png 02-Feb-20 01:31 PM for rotary vane I want either a Leybold D2.5 or any Ulvac GLD 02-Feb-20 01:31 PM several of these welch pumps: 02-Feb-20 01:31 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/49899637_386901325376123_65213773675652710-4FFE6.png 02-Feb-20 01:31 PM lots of vintage 02-Feb-20 01:32 PM yes 02-Feb-20 01:32 PM the free stuff is the stuff that has moved on first from being replaced and then being replaced as a backup 02-Feb-20 01:32 PM well, you know what I want now, others might want other things 02-Feb-20 01:32 PM but in general: everyone here will take all the free stuff 02-Feb-20 01:32 PM :P 02-Feb-20 01:32 PM with an asterisk on weight 02-Feb-20 01:34 PM And mercury content :P 02-Feb-20 01:34 PM that can be dealt with if it's especially valuable 02-Feb-20 01:36 PM ehh i am not sure that you would ever really get all the mercury out of something like a rotary pump...would be spewing tiny amounts of mercury vapor out the exhaust for a long time (especially when hot) 02-Feb-20 01:36 PM rotary pumps are not particularly valuable 02-Feb-20 01:36 PM especially if contaminated 02-Feb-20 01:36 PM and about half of that stuff looks to be old enough that is a possibility 02-Feb-20 01:38 PM Oh what about unknown condition pirani gauges? 02-Feb-20 01:38 PM they're not worth the effort/cost of making a cable, to us 02-Feb-20 01:38 PM digital or brainless? 02-Feb-20 01:38 PM brainless I believe. Will check, rj45 jacks 02-Feb-20 01:38 PM well if it's 0-10V, that's brained 02-Feb-20 01:38 PM pirani alone is somewhat valuable to some 02-Feb-20 01:39 PM oh then yeah probably that 02-Feb-20 01:39 PM stupid MKS gauges that have a floating 0-10V 02-Feb-20 01:39 PM I hate those so much 02-Feb-20 01:39 PM the 0V is something like -0.5V from PSU 02-Feb-20 01:39 PM hey don't say bad words about the 901p 02-Feb-20 01:39 PM they all speak perfectly grounded digital 02-Feb-20 01:39 PM :P 02-Feb-20 01:39 PM 972B is my complaint 02-Feb-20 01:40 PM yup, rs232 02-Feb-20 01:40 PM if you've got spares of those, I'll take your entire stock 02-Feb-20 01:40 PM lol 02-Feb-20 01:40 PM Why did they kill the 523 02-Feb-20 01:40 PM all 972 gauges speak either rs232 or rs485 02-Feb-20 01:41 PM Yeah they're fine for that but we also wanted a little OLED beside the gauge itself 02-Feb-20 01:41 PM that takes 15 minutes and an arduino 02-Feb-20 01:41 PM but would need a floating ADC 02-Feb-20 01:41 PM there's even code that does it for you 02-Feb-20 01:41 PM Yeah we have a ton 02-Feb-20 01:41 PM would have been done with a nano + OLED and be 15 min as you said 02-Feb-20 01:42 PM max3232, arduino, one of those 1" oleds 02-Feb-20 01:42 PM the evil part is that it actually conforms to rs232 spec so it would fry anything that isn't a genuine rs232 transceiver 02-Feb-20 01:42 PM :< 02-Feb-20 01:42 PM how dare they not do TTL and claim it was rs232 02-Feb-20 01:43 PM anyways whatever 02-Feb-20 01:43 PM everything just goes to an NI DAQ box and is displayed on a laptop now 02-Feb-20 01:43 PM that way it looks fancy 02-Feb-20 01:44 PM yeah 02-Feb-20 01:44 PM big label on the laptop "VIRTUAL PLC" 02-Feb-20 01:45 PM heh 02-Feb-20 01:45 PM the other groups have a lovely nim/similar $20,000 PLC system 02-Feb-20 01:45 PM the other groups need a budget cut 02-Feb-20 01:45 PM us? 4 year old thinkpad 02-Feb-20 01:46 PM 4 year old is not even old 02-Feb-20 01:47 PM So back to the question about cold heads being rushed to atmosphere 02-Feb-20 01:47 PM they don't like it but it doesn't damage them 02-Feb-20 01:47 PM if there's no automatic valve, what exactly happens if a turbo system with a 4k cold head has a power shutdown 02-Feb-20 01:48 PM pressures equalize and it just warms up slowly 02-Feb-20 01:48 PM how bad is that for the turbos? 02-Feb-20 01:48 PM slightly less bad than coming up to atmosphere 02-Feb-20 01:48 PM well, unless you had gas input 02-Feb-20 01:48 PM gas flux is tiny 02-Feb-20 01:48 PM then your condensed gas will evaporate, your chamber will go positive, and now you have flying viewports 02-Feb-20 01:49 PM related 02-Feb-20 01:49 PM how bad would this be for vacuum: 02-Feb-20 01:49 PM https://www.mcmaster.com/4772k4-4772K401 02-Feb-20 01:49 PM very 02-Feb-20 01:50 PM estimated leak rate? 02-Feb-20 01:50 PM significant enough to notice I'd say 02-Feb-20 01:50 PM anywhere from "significant" to "a lot" 02-Feb-20 01:50 PM Will find out 02-Feb-20 01:50 PM IDK on one hand, buying a $300 burst disk seems like a waste, on the other hand it's only a waste if you end up being grateful you have it.. 02-Feb-20 01:51 PM you can solve it by putting a normally open leak valve somewhere 02-Feb-20 01:51 PM since, as you said, your turbo mentions that it's fine to slowly vent it 02-Feb-20 01:51 PM if you have a power failure, you will automatically start venting a little, slowing the turbo 02-Feb-20 01:52 PM Oh yeah the overpressure and power failure are separate questions 02-Feb-20 01:52 PM normally people have pneumatic kf valves on their roughing lines that close in power failures, then just let the turbos spin down and equalize the pressure 02-Feb-20 01:53 PM simply put, you don't care if the cryopump loses power, as long as you can't have an overpressure event 02-Feb-20 01:53 PM it will warm up way slower than the turbo spinning down from a slowly increasing gas load 02-Feb-20 01:53 PM what about water freezing on it before it reaches atm? 02-Feb-20 01:53 PM do I get a big icicle? 02-Feb-20 01:54 PM yes, yes you will 02-Feb-20 01:54 PM and say that cold head is positioned above my turbopump 02-Feb-20 01:54 PM that would be unwise 02-Feb-20 01:54 PM position the cryopump below the turbo 02-Feb-20 01:54 PM can't 02-Feb-20 01:55 PM place a sheet of something between them just in case 02-Feb-20 01:55 PM a water droplet or piece of ice falling into the turbo at some tens of krpm would make it very unhappy 02-Feb-20 01:55 PM but that's very unlikely still 02-Feb-20 01:56 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-0A535.png 02-Feb-20 01:56 PM this is a similar apparatus 02-Feb-20 01:56 PM where there's often a turbopump above and below the "helium droplet source," which is attached to the tip of the cold head 02-Feb-20 01:56 PM above is a non-issue 02-Feb-20 01:56 PM below is 02-Feb-20 01:56 PM Yeah keyword "and" 02-Feb-20 01:57 PM putting a little shield should work 02-Feb-20 01:57 PM or just not putting a turbo there 02-Feb-20 01:58 PM I think a pneumatic valve to keep it in vacuum should be good enough 02-Feb-20 01:58 PM IDK how does a shield affect pumping? 02-Feb-20 01:58 PM oh yeah if you have a valve there it's fine 02-Feb-20 01:58 PM it's basically throttling the input 02-Feb-20 01:59 PM a shield shouldn't affect pumping unless it's severely throttling 02-Feb-20 01:59 PM this is where the 2200L/s pump is reaching ~1E-3 torr due to the helium gas load 02-Feb-20 01:59 PM when backed by a 600m^3/hour 1E-3 torr dry screw pump 02-Feb-20 01:59 PM whoops 02-Feb-20 02:00 PM like it would take ages to get overpressure, and the consumption of helium is negligible, and the only gas load is not stuff that makes ice 02-Feb-20 02:00 PM but pumping speed is important 02-Feb-20 02:00 PM Hmm in the other chamber the LN2 trap is also directly above a turbo 02-Feb-20 02:01 PM it won't be an issue in normal operation, but if you let something condense and drop, you may kill the turbos 02-Feb-20 02:03 PM so heating up the traps with hot air is not advised 02-Feb-20 02:03 PM no :P 02-Feb-20 02:03 PM "standard practice" when the chamber needs to be opened but has recently been used with LN2 02-Feb-20 02:03 PM is to suck it up with a vacuum cleaner 02-Feb-20 02:03 PM and then run room temp air through it from a compressed air line 02-Feb-20 02:05 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-AA95A.png 02-Feb-20 02:05 PM yup. 02-Feb-20 02:05 PM why not $123.45 02-Feb-20 02:06 PM even less likely to lowball 02-Feb-20 09:21 PM Question for the turbo wizards here - what would cause a seller to claim that a turbo is incapable of reaching a full vacuum? 02-Feb-20 09:21 PM "Full vacuum" being the ultimate pressure? 02-Feb-20 09:21 PM That's all they say 02-Feb-20 09:21 PM I'm gauging on how far I should lowball them 02-Feb-20 09:21 PM could be serious contamination 02-Feb-20 09:21 PM backstreamed oil maybe 02-Feb-20 09:21 PM Damaged flanges or internal seals? 02-Feb-20 09:22 PM So cleanable? 02-Feb-20 09:22 PM although 'ultimate pressure' on some turbos' datasheets can also be way down in the UHV range 02-Feb-20 09:22 PM Flanges look clean 02-Feb-20 09:22 PM Do you know if it reaches full speed? 02-Feb-20 09:23 PM not sure 02-Feb-20 09:23 PM Ultimate pressure can take hours of baking to reach 02-Feb-20 09:23 PM if it doesn't, that'd mean bearings that are about to quit 02-Feb-20 09:23 PM my EXT255H datasheet claims an ultimate pressure of something wacky like 10⁻¹⁰ torr iirrc 02-Feb-20 09:23 PM Yeah, can't you ask the seller directly? 02-Feb-20 09:24 PM I suppose I should 02-Feb-20 09:24 PM which like, okay, maybe if it was brand new and only ever handled under dry nitrogen in a cleanroom and attached to brand new conflat and then baked for a week 02-Feb-20 09:26 PM 5*10^-9 Torr ultimate pressure achieved for EXT255H after baking for two days 02-Feb-20 09:26 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-3B2AA.png 02-Feb-20 09:42 PM ah, off by an order of magnitude 02-Feb-20 09:42 PM whups 02-Feb-20 09:44 PM It's limited by the ISO flange, it's 5*10^-10 Torr for the CF version 02-Feb-20 09:47 PM oo, ok, yeah, mine's CF 02-Feb-20 09:47 PM Oh that's quite rare actually 02-Feb-20 11:15 PM <__ice9#6039> You can always use an aluminum KF gasket into a conflat adaptor to remove that limitation if desired with the DN100 ISO-K version (I have the EXT255Hi in ISO-K, though my use cases are not quite so rigorous as yet) 03-Feb-20 08:46 AM Joined the server. 03-Feb-20 10:02 AM flanges are pretty often damaged @qualia 03-Feb-20 10:02 AM when I'm going down to xhv like uhv I've to swap stuff every time 03-Feb-20 10:02 AM of course use fresh gaskets (clean and heated) 03-Feb-20 10:15 AM So I got a reply 03-Feb-20 10:15 AM The pump is running but the vacuum cannot be established. For these pumps, a revision is proposed by Edwards; they are changing oil and joints, as joints are making problems when the pumps are becoming old. I'm suggesting that it could be the problem (but not completely sure that it comes from that). It was not so noisy (what I rember, as I stopped it 9 months ago, when I bought my new equipment). 03-Feb-20 10:15 AM he's willing to give me this EXT255 for 190 eur including shipping 03-Feb-20 10:15 AM maybe I should do it 03-Feb-20 10:15 AM yeah, I will, offered him 180 eur instead though 03-Feb-20 10:15 AM I don't exactly need a new pump, but this is an offer I can't pass up, given that you can buy new viton rings from for peanuts, in almost any size 03-Feb-20 10:22 AM :)) 03-Feb-20 10:22 AM they give stuff away for free 03-Feb-20 10:22 AM of course you have to accept 03-Feb-20 10:23 AM who is they and how do I hold them hostage 03-Feb-20 10:23 AM 180 eur isn't exactly free 03-Feb-20 10:23 AM $200 03-Feb-20 10:23 AM but it's a very powerful pump compared to what I have 03-Feb-20 10:23 AM yeah ok but similar to free 03-Feb-20 10:24 AM plus it's the 24V version, not the weird 75-84V one 03-Feb-20 10:24 AM it's under the not-exactly-free threshold 03-Feb-20 10:24 AM oh and it has a drag stage, which is super nice 03-Feb-20 10:24 AM what I don't see in the manual is any seals 03-Feb-20 10:26 AM :(( envy 03-Feb-20 10:28 AM now to find a cheap spare EXDC80 or EXDC160 03-Feb-20 10:47 AM can you just buy a turbodrag 03-Feb-20 10:47 AM and then remove the turbo part 03-Feb-20 10:47 AM balancing? nah 03-Feb-20 10:47 AM Funny thing 03-Feb-20 10:47 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-90636.jpg 03-Feb-20 10:47 AM TPU 510 03-Feb-20 10:47 AM The seiko is STP-1000 03-Feb-20 10:47 AM 1991 I believe 03-Feb-20 10:54 AM ive heard that style of turbo is great if you buy it new but a nightmare to service 03-Feb-20 11:03 AM also makes a cool helmet. 03-Feb-20 11:04 AM @Spirit This Edwards service for EXT255 mentioned by the seller is funny. I've got a quotation for 2700$ for official "standard service". 03-Feb-20 11:04 AM That's not too bad for a turbo that costs ~$10k+ 03-Feb-20 11:05 AM 1 -Std Service EXT255H/Hi SRV000162 1 2 731.80 7.70%* 2 731.80 2 -Std Exch EXT255H DN100ISO-K B75301000XS 1 4 508.10 7.70%* 4 508.10 3 -Cert EXT255H DN100 ISO-K B75301000R 1 8 905.30 7.70%* 8 905.30 03-Feb-20 11:05 AM Now since you have two EXTs... with two controllers... 03-Feb-20 11:05 AM ;) 03-Feb-20 11:07 AM I was also torturing ajvs if they sell liquid turbo oil that they put into EXT255 oil cartridges. And Alpine Bearing about replacement bearings... No luck yet 03-Feb-20 11:27 AM I'll probably measure the bearings during my rebuild 03-Feb-20 11:27 AM you don't need custom bearings for these slower turbos 03-Feb-20 11:27 AM could probably even machine an adapter ring 03-Feb-20 12:13 PM @Spirit my understanding was that it's the EXDC80/160 that may or may not have the weird input voltage, not the EXT255 itself 03-Feb-20 12:13 PM or is that not the case? trying to see in manual... 03-Feb-20 12:23 PM duniway sells 'turbomolecular pump oil' that may suffice 03-Feb-20 12:23 PM i know whitequark (who i guess is no longer in here?) cleaned and re-did her EXT250H per https://lab.whitequark.org/notes/2015-07-08/cleaning-an-edwards-ext250-turbomolecular-pump/ , possibly the 255 is not too different 03-Feb-20 12:38 PM @samy 03-Feb-20 12:38 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-74188.png 03-Feb-20 12:38 PM also @qualia quark is in here 03-Feb-20 12:38 PM just not chatting 03-Feb-20 12:38 PM she's often in #sillycon on freenode 03-Feb-20 12:42 PM <__ice9#6039> I see this is quite a popular model 03-Feb-20 12:42 PM very 03-Feb-20 12:42 PM oh huh, autocomplete wasn't workin 03-Feb-20 12:53 PM https://alpinebearing.com/ball-bearings/cer-2280zzsd602/ 03-Feb-20 12:53 PM @ZeptoBars 03-Feb-20 12:53 PM this is... this is just a 608 bearing. 03-Feb-20 12:53 PM literally a 608 skateboard bearing, but ceramic. 03-Feb-20 12:56 PM @Spirit I see... I wonder what's the difference between EXT250 and EXT255... Look similar on the photos. 03-Feb-20 12:56 PM shouldn't be any 03-Feb-20 12:59 PM Then it's a pump for life... At least until cheap maglev pumps start to pop up for 300$... 03-Feb-20 12:59 PM @Spirit Both EXDC80 and 160 work for me (80V). 80 indeed apparently takes longer to spin-up, but ultimate speed seems to be the same. 03-Feb-20 01:01 PM oh, you have 80V ones :< 03-Feb-20 01:01 PM if the seller accepts, I'll need a 24v controller 03-Feb-20 01:03 PM I am not sure there are a difference on the pump side. We can verify winding resistances though. 03-Feb-20 01:03 PM 24V ones seems to have more features, like idle RPM 03-Feb-20 01:07 PM that image @Spirit posted seems to indicate that they're all 24V, no? If the same ultimate speed, then it'll be the same voltage; current will dictate torque (and thus spin-up time) and also explains the contra-indication of using the 160 for EXT70H as it would use higher current during spin-up than the windings are rated for. 03-Feb-20 01:08 PM yeah but it's weird 03-Feb-20 01:08 PM and I don't see anything smart about 24v controllers 03-Feb-20 01:10 PM @Spirit I thought you had your own controller in the works for any voltage 03-Feb-20 01:10 PM I also don't see whitequark or quark in here 03-Feb-20 01:11 PM I see whitequark in the offline list 03-Feb-20 01:13 PM @nmz787 I do, but it still hasn't arrived :{ 03-Feb-20 01:19 PM @Spirit ahh interesting, thanks! 03-Feb-20 02:47 PM Drivers may accept 24v, but that doesn't mean they're spitting out the same 3 phase voltages. 03-Feb-20 02:47 PM Not would the impedance be the same on both sides. 03-Feb-20 02:47 PM That said, I'm sure you can get away with a wide gamut of odd pairings 03-Feb-20 04:08 PM Ah I thought they were referring to output voltage not input 03-Feb-20 04:09 PM These are input 03-Feb-20 04:09 PM Either 24V, or 75-80V 03-Feb-20 04:09 PM From what I understand newer EXT250/255 turbos want 24 03-Feb-20 04:09 PM Then disregard my statement entirely lol 03-Feb-20 04:09 PM Older ones will work on 24, but want 75-80 03-Feb-20 04:20 PM What a silly voltage requirement. I don't think I've ever met stuff needing 75-80 in. 03-Feb-20 04:21 PM The EXDC supplies are supposed to be OEM/integrator supplies 03-Feb-20 04:21 PM But good luck finding an actual wall-plug controller for edwards turbos on ebay 03-Feb-20 04:21 PM They exist, and they're called EXC instead of EXDC 03-Feb-20 04:21 PM Build a big ol' linear boy 03-Feb-20 04:21 PM Get that chonky power transformer. 03-Feb-20 04:22 PM a 24V boost to 80 is probably what everyone does 03-Feb-20 04:23 PM if i have to use 70V (I just bought ext255hi from Mason), I'll probably run 24V+48V wallwarts in series 03-Feb-20 04:24 PM it's 75 to 80 03-Feb-20 04:24 PM which controller did you buy? 03-Feb-20 04:24 PM also @Mason_Yu is your turbo 75 or 24? 03-Feb-20 04:24 PM it should say on the label 03-Feb-20 04:24 PM a 24V turbo won't handle 75-80 03-Feb-20 04:24 PM It's 75V 03-Feb-20 04:24 PM right 03-Feb-20 04:24 PM @samy you'll want an EXDC160 rated for 75-80 03-Feb-20 04:24 PM https://www.ebay.com/itm/TB-Edwards-EXDC160-187W-Turbo-Pump-Controller-D39641500/292577526258 03-Feb-20 04:24 PM this one for example 03-Feb-20 04:25 PM EXDC80 will work also 03-Feb-20 04:25 PM but a lot slower 03-Feb-20 04:25 PM plus this one is pretty cheap 03-Feb-20 04:25 PM and looks like they will accept offers of $50 03-Feb-20 04:25 PM It's okay, takes like 2 to 3 minutes to spin up 03-Feb-20 04:27 PM @Spirit think i saw EXDC80s that supported 70-85V 03-Feb-20 04:27 PM yeah but they're less than half the power 03-Feb-20 04:27 PM you can get one though 03-Feb-20 04:27 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_2020-02-03_16.26.38-7E9D9.png 03-Feb-20 04:27 PM i see 03-Feb-20 04:28 PM and then you can get something like this 03-Feb-20 04:28 PM https://www.ebay.com/itm/DC-DC-8V-60V-to-12V-80V-600W-1200W-Step-Up-Power-Supply-Module-Boost-Converter/293248097842 03-Feb-20 04:28 PM pick the 600W 12-80 option 03-Feb-20 04:28 PM (cheaper units exist, look around too) 03-Feb-20 04:29 PM I'm pretty sure you can't even plug in the 24V controller to a 75V pump 03-Feb-20 04:29 PM yeah 03-Feb-20 04:29 PM they're keyed differently 03-Feb-20 04:29 PM and then a generic 24V 8.3A supply should be good 03-Feb-20 04:41 PM My first run was indeed with 24->80 boost, but now I got beefy 600W 80V PSU. Not sure why. Running on 24V is so much more convenient. 03-Feb-20 04:53 PM i have a spare EXDC80 but it's for 80V/EXT250 03-Feb-20 04:53 PM i use the 160 on my EXT250 with a way-overkill 400W linear 80VDC supply 03-Feb-20 05:02 PM <__ice9#6039> Ah yeah mine just came with the appropriate EXDC attached, though I still needed to build a small control/display/power box 03-Feb-20 05:03 PM everyone has edwards pumps 03-Feb-20 05:03 PM <__ice9#6039> inorite 03-Feb-20 05:03 PM hopefully I will join the club soon 03-Feb-20 05:03 PM I only asked for 10 eur off his offer 03-Feb-20 10:46 PM mhhmm 75 euro 03-Feb-20 10:46 PM that's pretty cheap right 04-Feb-20 12:11 AM I have a non-working Edwards pump, does that count? 04-Feb-20 12:19 AM I have a coworker named Edward 04-Feb-20 12:46 AM .o(a former coworker) 04-Feb-20 02:20 AM Yay. My x-ray head arrived. Completely dead. 04-Feb-20 02:20 AM Leaking oil through a crack in the beryllium window. 04-Feb-20 02:20 AM $1200. Down the drain. 04-Feb-20 02:22 AM hopefully not literally, the oil is bad for the Environment 04-Feb-20 02:26 AM Don't worry, it caused a mini BP oil spill on my floor too, when I cracked the wrong screw. 04-Feb-20 04:36 AM ouch I'm sorry 04-Feb-20 04:36 AM I'm on the Gulf, I can ship you some of our water - it surely still has some dispersants to handle that spill 04-Feb-20 06:22 AM <__ice9#6039> Hmm. So there are a few things that can be done to get it working to some extent. 04-Feb-20 06:22 AM <__ice9#6039> Unless you mean the window in the tube, rather than the window in the tube head? 04-Feb-20 06:22 AM <__ice9#6039> If you just mean the tube head, then due to the broken window it will need a rebuild. Opening it up (usually lots of bolts) will show you whether the tube itself is intact. If the tube is also broken then you may be able to get a different tube to swap in depending on size and rigidity of connectors 04-Feb-20 06:22 AM <__ice9#6039> And it may also be worth considering whether to just scrap it for those very nice transformers if a swap is not possible 04-Feb-20 06:22 AM <__ice9#6039> Assuming the tube is not broken, or is replaceable if you want to go that route: save the oil in a bucket. Clean off the exterior surface of the beryllium window carefully with a solvent. If the window is outright missing large pieces then it may not be practical to save it and it could be replaced with e.g. aluminum. But if it is a small crack, it could be paved over with a thin layer of epoxy, or an oil-resistant melted rigid polymer coating. 04-Feb-20 06:22 AM <__ice9#6039> But for $1200 it's probably better to return it and try again 04-Feb-20 06:22 AM <__ice9#6039> If possible 04-Feb-20 06:22 AM <__ice9#6039> Your other option is to buy and install a replacement beryllium window (again assuming you mean the tubehead rather than the actual tube). This would involve removing the old one under oil, ordering a new one, carefully cleaning the new one of any dust under oil, cleaning the new one and the area with a solvent to remove the oil, epoxying the new one in place, and refilling the tank head with oil. 04-Feb-20 06:22 AM <__ice9#6039> Again may not be worth the trouble if returning it is possible 04-Feb-20 06:45 AM <__ice9#6039> Another option, depending on the design of the tube, would be to replace the housing-- which can be done with the tube not under oil or behind any window at all if you pot the terminals well enough, just the transformer. eBay has some reasonably decent 150kV cable available. Keeping the transformers in an oil bucket with a lid and exits for 2x 150kV cables (assuming a split rail output with a filament transformer -- some designs just put the cathode at ground potential and HV only at the anode, meaning only 1 HV cable) to a tube mounted in a lead-lined box with potting epoxy around the HV contacts to a depth of at least 2 cm (good to ~600kV for most formulations). 04-Feb-20 06:45 AM <__ice9#6039> To further enhance the insulation quality of silicone HV cabling, successive layers of fluoropolymer heat shrink tubing are the most volume-efficient method at 500-600kV/cm, but ordinary heat shrink tubing should be good to about 180-250kV/cm as well. Useful if you get any significant corona losses, though depending on the application they may be tolerable. 04-Feb-20 08:49 AM what killed it? 04-Feb-20 08:49 AM the transport? 04-Feb-20 09:15 AM someone should do a meta-analysis of scientific papers wherein they analyze the length of any "conclusions" or "discussion" sections with respect to year published 04-Feb-20 09:15 AM it seems to me that around the mid 90's people stopped caring about really sharing the meaty take-aways 04-Feb-20 09:30 AM https://pbs.twimg.com/media/ELCkC48XUAEhRA0?format=jpg&name=medium 04-Feb-20 09:30 AM applies to more than just biology... 04-Feb-20 10:45 AM ... Yea... its called any project 90% of the time lol 04-Feb-20 11:08 AM Except medicine where they write the conclusion before they do the experiment 04-Feb-20 11:13 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200204_220320-584E8.jpg 04-Feb-20 11:13 AM Yup. 04-Feb-20 11:32 AM <__ice9#6039> Huh. 04-Feb-20 11:32 AM <__ice9#6039> That looks like a broken tube if I'm seeing this correctly 04-Feb-20 11:32 AM <__ice9#6039> Hope it's returnable x___x 04-Feb-20 11:35 AM Nnnnnope 04-Feb-20 11:35 AM Lost all the money irreversibly 04-Feb-20 11:35 AM But I suppose I have a very high power 130kv power supply... 04-Feb-20 11:46 AM ehehee 04-Feb-20 11:46 AM fry some pickles 04-Feb-20 11:46 AM I mean how sad it would look like - frying pickles with a power supply of a dead microfocus(?) xray source 04-Feb-20 11:46 AM I guess the idea was purchasing something like https://www.thermofisher.com/order/catalog/product/PXS10#/PXS10 04-Feb-20 11:50 AM yeah pretty much 04-Feb-20 11:50 AM aww :(( 04-Feb-20 11:50 AM but I know the feelz 04-Feb-20 11:50 AM I mean it was that 04-Feb-20 11:50 AM except Hamamatsu, and a bit less microfocus 04-Feb-20 11:50 AM oh jeez 04-Feb-20 11:50 AM I think 10 micron 04-Feb-20 11:51 AM thats sad bro 04-Feb-20 11:51 AM the rollercoaster of feelings opening the package 04-Feb-20 11:51 AM I'm going to cry* *cash card or credit 04-Feb-20 11:51 AM I can taste the anger 04-Feb-20 11:51 AM I knew it was dead before I opened it 04-Feb-20 11:51 AM heard rattling at the post office 04-Feb-20 11:52 AM :((( 04-Feb-20 11:52 AM getting it shipped was a rollercoaster too 04-Feb-20 11:52 AM I've accepted defeat months ago 04-Feb-20 11:53 AM today I got customs informations that they accidentally sent back 2 packages 04-Feb-20 11:54 AM There is a head that I could buy, but it's too expensive 04-Feb-20 11:54 AM Or, it would be too expensive and uncertain 04-Feb-20 11:54 AM one was a toptica laser I wanted to reverse 04-Feb-20 11:54 AM I have a fizeau incoming, I hope they don't fck up that one 04-Feb-20 11:54 AM (for them ) 04-Feb-20 11:54 AM jk 04-Feb-20 12:01 PM <__ice9#6039> Huh that sucks 04-Feb-20 12:01 PM <__ice9#6039> If it's any consolation, compatible tubes might be available for less than $200 04-Feb-20 12:01 PM <__ice9#6039> Idk though I've gotten all of my x-ray stuff by lowballing sellers and buying Russian surplus assets 04-Feb-20 12:02 PM 200? 04-Feb-20 12:02 PM <__ice9#6039> Which doesn't lend itself to being picky 04-Feb-20 12:02 PM I'm in 04-Feb-20 12:02 PM this one is never getting a replacement tube 04-Feb-20 12:02 PM they're proprietary to hamamatsu 04-Feb-20 12:02 PM <__ice9#6039> There are a lot of x-ray tubes all over eBay under $200, but I do not know about microfocus ones 04-Feb-20 12:02 PM <__ice9#6039> Oh I just said compatible. I didn't say identical. 04-Feb-20 12:03 PM totally proprietary to hamamatsu 04-Feb-20 12:03 PM voltages, controls, etc 04-Feb-20 12:03 PM https://youtu.be/-4Y0EGrh0TY 04-Feb-20 12:03 PM <__ice9#6039> What 04-Feb-20 12:03 PM <__ice9#6039> Is there like a "hide post" button on discord 04-Feb-20 12:03 PM if 200 for a microfocus 04-Feb-20 12:03 PM lel 04-Feb-20 12:05 PM <__ice9#6039> Just search 'x ray tube' (no hyphen) and sort by price low to high, there's good stuff out there 04-Feb-20 12:05 PM <__ice9#6039> But I don't know about microfocus ones 04-Feb-20 12:05 PM <__ice9#6039> How many mA is that PSU good for @Spirit ? 04-Feb-20 12:06 PM I'm not entirely sure 04-Feb-20 12:06 PM I believe around 300uA 04-Feb-20 12:07 PM <__ice9#6039> Oh huh that's tiny 04-Feb-20 12:07 PM <__ice9#6039> Ok I understand now 04-Feb-20 12:07 PM it might be much higher 04-Feb-20 12:07 PM I can't find the exact tube I bought 04-Feb-20 12:08 PM <__ice9#6039> Do you know how many watts gross wall power it draws or says on the back? 04-Feb-20 12:08 PM ah yeah no it's 300ua 04-Feb-20 12:08 PM 130kv at 300ua 04-Feb-20 12:08 PM <__ice9#6039> Hmm I see 04-Feb-20 12:08 PM <__ice9#6039> Am reminded of one I just saw that uses a very smooth falling stream of liquid gallium as the anode 04-Feb-20 12:08 PM <__ice9#6039> Hmm but yeah anyway for higher power levels, there are loads of decommissioned CT tube housings with the tube still present for $200 or less. Sophisticated rotating-anode tubes with liquid cooling set up inside a heavy shielded tank enclosure. 04-Feb-20 12:08 PM <__ice9#6039> Usually between 115-180kVp for continuous operation 04-Feb-20 12:08 PM <__ice9#6039> Though given kVp is limited mainly by arcover along the walls, I suspect they could go much higher in flash 04-Feb-20 12:11 PM le petit homme gallium pisse 04-Feb-20 12:11 PM x-ray source 04-Feb-20 12:11 PM <__ice9#6039> Obviously powering such a thing at maximum power would be totally ridiculous. It would draw a hundred kilowatts. 04-Feb-20 12:11 PM <__ice9#6039> But that isn't the point. The point is that the trade off is duty cycle. As long as you keep it spinning, it basically cannot overheat 04-Feb-20 12:11 PM <__ice9#6039> Anyway there are a lot of normal fixed anode tubes as well 04-Feb-20 12:11 PM <__ice9#6039> Medical/dental ones mainly, but also some Be-windowed Russian XRF tubes 04-Feb-20 12:21 PM @Spirit why no hope of money back, no eBay guarantee? 04-Feb-20 12:22 PM too late 04-Feb-20 12:23 PM Hmm, but if you just got it 04-Feb-20 12:23 PM Seems worth an appeal to eBay, if Shipping took so long, that's not your fault 04-Feb-20 12:24 PM It's not ebay's shipping fault 04-Feb-20 12:24 PM I had someone reship it 04-Feb-20 12:24 PM took them a while to get around to it 04-Feb-20 12:26 PM :( 04-Feb-20 12:27 PM <__ice9#6039> Ah yeah that's a common scam with Chinese economy shipping too. Sometimes they never send it. 2 months later you remember. Too late. 04-Feb-20 12:27 PM <__ice9#6039> Though I did just receive some extruded grid graphite support blocks after months, which was a pleasant surprise 04-Feb-20 12:29 PM Yep 04-Feb-20 12:38 PM Basically why i got a virtual credit card for AliExpress 04-Feb-20 12:38 PM Hoping if crap happens it will be easier to isolate funny business 04-Feb-20 12:50 PM <__ice9#6039> @Spirit @N00N 04-Feb-20 12:50 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/1580849398369-40DF1.png 04-Feb-20 12:50 PM you'd need to be insane to run the bottom one 04-Feb-20 12:50 PM the top one is something like 70 micron 04-Feb-20 12:51 PM <__ice9#6039> I was talking about the top one 04-Feb-20 12:51 PM <__ice9#6039> So there are indeed micro focus tubes for under $200 04-Feb-20 12:51 PM <__ice9#6039> Granted maybe not as good as you need 04-Feb-20 12:51 PM 70 microns is barely microfocus 04-Feb-20 12:51 PM baaaaaarely 04-Feb-20 12:51 PM <__ice9#6039> Yeah exactly 04-Feb-20 12:51 PM you can get 150um dental tubes 04-Feb-20 12:51 PM I also have a 40um soviet tube, but it's grounded anode and hard to drive 04-Feb-20 12:51 PM and also hard to focus, because it needs fancy wehnelt voltage control and a magnetic lens(which I thankfully have, from another machine) 04-Feb-20 01:09 PM So a rotary vane pump hooked directly to a mks901p is probably a bad idea due to oil backstreaming, right? 04-Feb-20 01:09 PM Just for testing the pump 04-Feb-20 01:11 PM I've hooked them up via a few foot tube... I wouldn't sit it RIGHT on the inlet... Either way your right, it is not good for it, but I mean considering the price of the gauges I just have one I use for testing like that and yea... just accept that the gauge should probably not be used in UHV settings and such anymore. 04-Feb-20 01:53 PM @nmz787 it would be fine but also I wouldn't do it lol. At least add a few feet of tube or something. 04-Feb-20 01:53 PM Hmm, having a gauge just for testing pumps isn't a bad idea 04-Feb-20 01:55 PM nice thing about hot ion gauges is the self-baking feature 04-Feb-20 02:25 PM dammit, NPT got me again 04-Feb-20 02:25 PM 1/4" NPT is 1/2" 04-Feb-20 02:25 PM I had forgotten 04-Feb-20 02:55 PM yeah i'm pretty confused by the NPT sizes 04-Feb-20 02:55 PM i keep meaning to google "npt for dummies" 04-Feb-20 03:55 PM push-to-connect fittings are godly though 04-Feb-20 06:44 PM @samy there is really no way to logic/deduce/reason your way to knowing the physical size from the thread size. The thread sizes/labels originated from the inner diameter of the pipe that calls for it. That is, a 1/2" NPT fastener should be used for a 1/2" nominal pipe size to ensure adequate thread engagement for the 1/2" NPS's wall thickness . 04-Feb-20 06:44 PM and that was back when there weren't a bunch of different pipe standards that differ in wall thickness 04-Feb-20 06:44 PM e.g. 1/4" NPT has a shank OD of 1/2" and 3/4" NPT's is 1" so you can't just multiply by two. You just learn independently 04-Feb-20 06:50 PM ahh 04-Feb-20 07:16 PM <__ice9#6039> I standardized almost everything pipe-related on 1/4 NPT, except some 1/8 NPT (some gauges, also water filter membrane housings that I like to use to hold zeolites and silica gel and similar sorbents) 04-Feb-20 07:16 PM <__ice9#6039> 6mm push connect is standard, except 10mm for high flow uses 04-Feb-20 07:16 PM <__ice9#6039> 1/4 NPT quick disconnect fittings, female for all gas sources and male for all consumers 04-Feb-20 07:16 PM <__ice9#6039> Similarly, 5.5mm power jacks, except there the standard convention is male for PSUs and female for devices to keep device profiles sleek, so I maintained that 04-Feb-20 07:16 PM <__ice9#6039> 24/40 for chemical glassware, except a few items in the largely compatible 24/29, and a few wide-bore joints for particularly large objects like that reactor I use for ceramics 04-Feb-20 07:16 PM <__ice9#6039> C13/C14 for AC power at 125V and some universal 110-250V items 04-Feb-20 07:16 PM <__ice9#6039> NEMA 6-50 for welders 04-Feb-20 07:16 PM <__ice9#6039> NEMA 14-50 for heavy applications and distribution 04-Feb-20 07:16 PM <__ice9#6039> Would have preferred 14-60 tbh but harder to source. Usually use 6 AWG in those lines, so everything runs very cool. Smallest is 8 AWG. 04-Feb-20 07:16 PM <__ice9#6039> Hose barbs for silicone and polyurethane, push to connect (John Guest clones) for polyethylene, PTFE, FEP, and nylon (don't buy nylon tubing unless you need it for some reason, is very annoying to work with) 04-Feb-20 07:16 PM <__ice9#6039> @Spirit you can make your own filament transformer by taking a big wide ferrite e.g. 100mm O.D., wrapping a primary for the filament drive, potting it in a mold, wrapping the 1:1 secondary, and potting again in a container. Important to steer very clear from the primary leads when winding the secondary though. Alternately, can use a square iron core and cast a cylindrical block of plastic around one end for winding the HV secondary and wind the primary as normal on the other side, use in oil. 04-Feb-20 07:32 PM huh? 04-Feb-20 07:32 PM wrong ping? 04-Feb-20 07:41 PM <__ice9#6039> Hmm no, for driving a grounded anode tube 04-Feb-20 07:42 PM oh yeah I'm aware, I've made my own silicone potted filament transformer with post-regulation 04-Feb-20 07:42 PM (it sounds fancy but it's just a ZVS driving a huge transformer fed into a rectifier/CC supply) 04-Feb-20 07:42 PM <__ice9#6039> Yeah exactly 04-Feb-20 07:42 PM <__ice9#6039> What's the difficulty driving grounded anode then, apart from needing one of these? 04-Feb-20 07:43 PM a well regulated HV PSU 04-Feb-20 07:43 PM <__ice9#6039> Oh ofc 04-Feb-20 07:43 PM <__ice9#6039> Flybacks can get you to about 40-50kV 04-Feb-20 07:44 PM sure, but in this case I'd need -100 04-Feb-20 07:44 PM at a good 5-10W 04-Feb-20 07:44 PM the feedback is the biggest issue really 04-Feb-20 07:45 PM <__ice9#6039> A 1-2 stage full bridge Cockcroft-Walton multiplier will be pretty stable at e.g. 50kHz as long as you use big enough caps 04-Feb-20 07:45 PM <__ice9#6039> Yeah that part is annoying tbqh 04-Feb-20 07:45 PM <__ice9#6039> Need active control 04-Feb-20 07:45 PM the actual feedback is the pain 04-Feb-20 07:45 PM <__ice9#6039> Can get the voltage with a unity buffer op amp reading from a voltage divider, but the controller is annoying 04-Feb-20 07:45 PM <__ice9#6039> Personally I would probably just break out an Arduino at that point 04-Feb-20 07:45 PM you can't use just a resistor divider, since the "tiny" 50-100V ripple on the output is going to result in the AC component on the end being un-divided 04-Feb-20 07:45 PM so you get 0-10V for 0-100kV 04-Feb-20 07:45 PM with 100V of ripple 04-Feb-20 07:45 PM lol 04-Feb-20 07:47 PM <__ice9#6039> I think I am misunderstanding something you are stating here. I have routinely used voltage dividers into op-amp buffers, including for negative voltages 04-Feb-20 07:47 PM <__ice9#6039> Just set the divider from like -100kV to like +10V instead of ground, makes it simpler 04-Feb-20 07:47 PM <__ice9#6039> 1 gig against 100K 04-Feb-20 07:47 PM <__ice9#6039> The +10V should be a regulated source 04-Feb-20 07:47 PM <__ice9#6039> But the amount of current coming in from the divider is quite small. This means you need an op-amp yes, but it also means little power is wasted and the regulated reference source has no issues 04-Feb-20 07:47 PM <__ice9#6039> Arduino input impedance is only like 10k or something very low like that, so end up needing op-amps for everything always 04-Feb-20 07:47 PM <__ice9#6039> Also I misspoke above, should be 50K not 100K. Don't want the signal to go below 0 04-Feb-20 07:47 PM <__ice9#6039> So with that, if you have 100kV with +/-5kV ripple and your controller is trying to get it to converge, it sees 5V with +/-0.25V 04-Feb-20 07:47 PM <__ice9#6039> Etc 04-Feb-20 07:54 PM hm 04-Feb-20 07:54 PM but the AC voltage will have funny capacitive effects when being divided 04-Feb-20 07:54 PM <__ice9#6039> Oh you meant that 04-Feb-20 07:54 PM <__ice9#6039> Yeah if your ripple is high enough frequency 04-Feb-20 07:54 PM yeah, and it would be 04-Feb-20 07:55 PM <__ice9#6039> I built a 300kV capacitive HV probe 04-Feb-20 07:55 PM <__ice9#6039> And it works fine on a 40kHz NST 04-Feb-20 07:55 PM <__ice9#6039> So I know what you mean 04-Feb-20 07:55 PM <__ice9#6039> The key for dealing with that is 04-Feb-20 07:55 PM <__ice9#6039> You need a parallel capacitive divider 04-Feb-20 07:55 PM <__ice9#6039> But 04-Feb-20 07:55 PM <__ice9#6039> At really high voltages the thing starts getting susceptible to EMI 04-Feb-20 07:56 PM ideally you want to completely remove the AC ripple 04-Feb-20 07:56 PM so you only get DC 04-Feb-20 07:56 PM <__ice9#6039> So then you have to play some games with the shielding 04-Feb-20 07:56 PM <__ice9#6039> Ok but like high frequency ripple you can just filter out 04-Feb-20 07:56 PM <__ice9#6039> At some point the cap sizes are prohibitive 04-Feb-20 07:56 PM stuff like falstad won't show you this 04-Feb-20 07:56 PM need to do actual spice simulation 04-Feb-20 07:57 PM <__ice9#6039> Well yeah obviously 04-Feb-20 07:57 PM <__ice9#6039> I wouldn't try to design one of these without SPICE, I would begin there 04-Feb-20 07:57 PM SPICE hates me 04-Feb-20 07:57 PM <__ice9#6039> Anyway if you do a T filter instead of a Pi filter then you only need one cap 04-Feb-20 07:57 PM <__ice9#6039> Huh what flavor do you use? I use LTspice in a VM 04-Feb-20 07:57 PM <__ice9#6039> But with a bunch of downloaded libraries 04-Feb-20 07:58 PM @Spirit Btw have you tried Micro-Cap? 04-Feb-20 07:58 PM for SPICE. 04-Feb-20 07:58 PM as a way to cheat you could probably put a high frequency filter on the low leg of the divider 04-Feb-20 07:58 PM <__ice9#6039> I made calculation spreadsheets to make custom diodes and FETs also 04-Feb-20 07:58 PM so you just eat the HF stuff with a filter 04-Feb-20 07:59 PM THat's what I'd do 04-Feb-20 07:59 PM filter it 04-Feb-20 07:59 PM <__ice9#6039> Yeah I have made dividers like that before 04-Feb-20 07:59 PM I'll look at it when making a divider for this nanofocus tube I'm going to be building a supply for 04-Feb-20 07:59 PM going to be pretty much entirely PCB-mounted, even the HV stuff 04-Feb-20 08:00 PM <__ice9#6039> You can also put diodes and little tiny caps on the high side to track the peak voltage with some RC decay 04-Feb-20 08:00 PM oh? 04-Feb-20 08:00 PM <__ice9#6039> Yeah, just run a diode from the HV to the divider 04-Feb-20 08:00 PM <__ice9#6039> Then the HV charges the cap, which discharges through the divider gradually 04-Feb-20 08:01 PM I'm not sure I understand 04-Feb-20 08:01 PM <__ice9#6039> It's just like a rectified AC smoothing cap driving a resistive load 04-Feb-20 08:01 PM <__ice9#6039> It only gets charged at the peaks, right? 04-Feb-20 08:01 PM so you're proposing to put a cap from HV to ground 04-Feb-20 08:02 PM <__ice9#6039> Yeah but only some hundreds pF or less 04-Feb-20 08:02 PM <__ice9#6039> Because the multiplier has such enormous resistance 04-Feb-20 08:02 PM <__ice9#6039> That the RC time constant will still be pretty long even with tiny cap 04-Feb-20 08:02 PM <__ice9#6039> So you just chain a bunch of cheap small HV caps in series 04-Feb-20 08:02 PM <__ice9#6039> Works fine 04-Feb-20 08:02 PM <__ice9#6039> example: +100kV +/-5kV -> diode -> multiplier, cap (both connect to ground on the other end) 04-Feb-20 08:02 PM <__ice9#6039> You cannot just put the cap on the low half of the divider, though, because it will drain faster than the upper half can charge it and thereby screw up the voltage indicated by the divider. So it really does need to span the full divider. 04-Feb-20 08:05 PM I was thinking of a resistive divider with an RC filter on the output 04-Feb-20 08:05 PM <__ice9#6039> You can also get minimum recent voltage (instead of max/peak) by just reversing the diode 04-Feb-20 08:05 PM <__ice9#6039> You can do that, but only if you put an op-amp buffer between the middle of the divider and the RC filter 04-Feb-20 08:05 PM <__ice9#6039> That will give you the average instead of the peak and it will be limited by op-amp slew rate 04-Feb-20 08:05 PM <__ice9#6039> Note you can do the same thing by doing what I just described but without the diode 04-Feb-20 08:07 PM except you'd have to filter the AC before any digital stuff 04-Feb-20 08:07 PM <__ice9#6039> ...? 04-Feb-20 08:07 PM since the funny AC stuff might shoot way past the supply voltages of the LV part 04-Feb-20 08:07 PM <__ice9#6039> Already described how to read the current HV voltage as an analog input with a divider above 04-Feb-20 08:07 PM <__ice9#6039> Hmm not if you design your multiplier correctly 04-Feb-20 08:07 PM <__ice9#6039> If you have an HV supply for 50-100kV, then rescale 0-200kV to 0-10V, you are not going to see 11V. 04-Feb-20 08:09 PM sure, I guess you could just divide further than needed 04-Feb-20 08:10 PM <__ice9#6039> Likewise, for negative 50-100kV, if you rescale [-200kV, 0] to [0, 10] in the manner I described, then you are not going to see anything lower than 0 04-Feb-20 08:10 PM <__ice9#6039> Yes, exactly. I would argue that you have to, for safety reasons to protect your ADC 04-Feb-20 08:11 PM how would one easily convert -100kv to a positive divider though 04-Feb-20 08:11 PM <__ice9#6039> TVS diodes will not clamp precisely enough to deal with overages, so it's better to just allow some margins 04-Feb-20 08:11 PM with a single phase CW 04-Feb-20 08:11 PM <__ice9#6039> I described that above 04-Feb-20 08:11 PM <__ice9#6039> Example 04-Feb-20 08:12 PM something something kicad or falstad 04-Feb-20 08:12 PM handy for sanity checking 04-Feb-20 08:12 PM <__ice9#6039> -100kV into 1Gig, 1Gig into 50K, 50K to +10V 04-Feb-20 08:12 PM oh well yeah an offset 04-Feb-20 08:12 PM <__ice9#6039> Yes. 04-Feb-20 08:12 PM <__ice9#6039> Tired. May be back later though. Hope this is helpful! 04-Feb-20 08:14 PM yup 04-Feb-20 08:14 PM thanks 04-Feb-20 08:14 PM I will definitely attempt 05-Feb-20 12:03 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/v90C6-58FAA.png 05-Feb-20 12:03 AM Whoops. 05-Feb-20 12:10 AM hope you have better luck this time 05-Feb-20 12:10 AM was the issue on the last one not enough packing? not secure enough? or something else entirely? lol 05-Feb-20 12:50 AM Not sure really 05-Feb-20 12:50 AM I think a mix of all of them 05-Feb-20 12:50 AM But the seller is buckling on shipping now, wants to ship DHL(which will immediately rake my bum through customs) 05-Feb-20 01:21 AM So here's a really dumb idea 05-Feb-20 01:21 AM ... could one use an impeller from a diesel turbocharger(usually >100krpm rated for an ISO100-sized spinny, so huge overhead) as a really bad mix of turbomolecular, drag, and centrifugal fan? 05-Feb-20 01:21 AM Considering it's rated for over 100krpm in a high density, incredibly dirty atmosphere with crap flying at it... 05-Feb-20 01:21 AM And if you do the math, the blades are going supersonic 05-Feb-20 01:23 AM there is a russian guy who made a small turbojet with what i think were turbocharger impellers 05-Feb-20 01:23 AM Igor Negoda, yes 05-Feb-20 01:23 AM I'm talking about using it for high vacuum 05-Feb-20 01:23 AM It'd be an incredibly robust, unkillable setup if done right 05-Feb-20 01:24 AM yeah i was just saying that it might be possible if it works for the compression stage of those little jet engines...but i would not get my hopes up 05-Feb-20 01:27 AM Could also attempt doing something slightly different 05-Feb-20 01:27 AM Cutting slots in the blades of the impeller and putting stators in 05-Feb-20 01:27 AM That would essentially make a really poorly designed turbomolecular pump 05-Feb-20 01:27 AM But a pump you can overdrive to insanity 05-Feb-20 01:27 AM only issue would be getting a motor that you can stick in a vacuum that would spin up to 100 000 rpm 05-Feb-20 01:29 AM also the dynamic balancing of whatever shaft you mount the impeller on 05-Feb-20 01:30 AM a polished rod would solve that issue 05-Feb-20 01:30 AM polished/ground 05-Feb-20 01:30 AM they're generally well within balance 05-Feb-20 09:48 AM anyone have any suggestions for a good variable power supply <$200 05-Feb-20 09:48 AM Can’t buy off eBay or surplus because it’s for research group and uni ordering is annoying like that 05-Feb-20 10:08 AM Korad ka3005p @mike crb 05-Feb-20 10:14 AM <__ice9#6039> @Spirit blade angle may be an issue, but could perhaps be addressed with proper stator design if they fit. Seems likely to be vastly more time and cost than importing one of those small drag pumps though. 05-Feb-20 10:14 AM Heh 05-Feb-20 10:19 AM @__ice9 do you have any experience with bridgman furnaces? they seem...deceptively simple 05-Feb-20 10:20 AM <__ice9#6039> Lol this is actually a lot like zone melting 05-Feb-20 10:20 AM <__ice9#6039> The tricky part is the container and the cable supporting it 05-Feb-20 10:20 AM <__ice9#6039> The cable can be made of tungsten wire if you use inert gas shielding 05-Feb-20 10:20 AM <__ice9#6039> In general this is going to need a gas shield if you go above about 1400C 05-Feb-20 10:20 AM <__ice9#6039> The container is more difficult because it needs to avoid contamination of the melt 05-Feb-20 10:22 AM the stuff i was looking at should not require much over 800C 05-Feb-20 10:22 AM <__ice9#6039> Common choices would be e.g. platinum, iridium, molybdenum, graphite 05-Feb-20 10:22 AM <__ice9#6039> Depending on the crystal material and purity requirements 05-Feb-20 10:22 AM <__ice9#6039> Oh that's far easier than higher temps 05-Feb-20 10:23 AM https://sci-hub.se/10.1021/cg100557e 05-Feb-20 10:23 AM <__ice9#6039> Kanthal elements, suspension cable made of twisted up Kanthal wire 05-Feb-20 10:23 AM was looking at that paper and it really does not seem terribly challenging besides the custom quartz tube 05-Feb-20 10:23 AM <__ice9#6039> What material do you want to crystalize? 05-Feb-20 10:23 AM <__ice9#6039> You can make the outer heating tube out of literally any common furnace material you want; 800C is frigid 05-Feb-20 10:23 AM <__ice9#6039> It doesn't need to be quartz 05-Feb-20 10:23 AM <__ice9#6039> Ah quartz vessel 05-Feb-20 10:25 AM yep just what the paper used and i have not looked into alternate options...think other stuff might not handle a molten bromide too well 05-Feb-20 10:25 AM <__ice9#6039> I see you are interested in LaBr 05-Feb-20 10:25 AM <__ice9#6039> Yeah that's just a salt 05-Feb-20 10:25 AM <__ice9#6039> You could probably grow scintillator crystals this way too, but thallium vapors are horrible 05-Feb-20 10:25 AM <__ice9#6039> I didn't realize you just wanted a salt 05-Feb-20 10:25 AM <__ice9#6039> Quartz is almost always the answer for salts 05-Feb-20 10:26 AM LaBr(Ce) is a scintillator which is my interest 05-Feb-20 10:27 AM <__ice9#6039> Really high melting salts may need sapphire 05-Feb-20 10:27 AM <__ice9#6039> But this one.. isn't 05-Feb-20 10:27 AM <__ice9#6039> Yeah you just need a tube furnace with double the coil density at the top and a quartz ampoule. This is pretty simple. 05-Feb-20 10:27 AM <__ice9#6039> I've got a good contact for quartz glassware, just a sec 05-Feb-20 10:27 AM yep it seems too simple was my hang up 05-Feb-20 10:27 AM there must be something we are missing or LaBr3 scintillators would be more common...? 05-Feb-20 10:28 AM <__ice9#6039> Talk to the seller of this item https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F283430738383 05-Feb-20 10:28 AM <__ice9#6039> This person had a wonderful 24/40 500mL long-neck male-fitting quartz flask made for me a little while ago. It is absolutely flawless. 05-Feb-20 10:28 AM <__ice9#6039> And it will run corrosive gas pyrolysis to well over 1200C 05-Feb-20 10:28 AM <__ice9#6039> In your case for this, you will probably want an open top quartz beaker, but with probably a rounded bottom, and several hanging loops along the rim 05-Feb-20 10:28 AM <__ice9#6039> That can be made optional if you just use a Kanthal wire basket though 05-Feb-20 10:28 AM <__ice9#6039> The loops I mean 05-Feb-20 10:28 AM <__ice9#6039> If you can find a beaker made of quartz or Vycor you can just use that 05-Feb-20 10:32 AM i think the ampule needs to be evacuated and sealed shut for the actual melt 05-Feb-20 10:32 AM <__ice9#6039> That's a hassle, just fill the furnace with argon 05-Feb-20 10:33 AM that might work 05-Feb-20 10:33 AM i wonder what the smallest feasible diameter for a decent single crystal would be 05-Feb-20 10:33 AM guess i will think about the logistics of this and the whole furnace build a bit more and not immediately discard this idea 05-Feb-20 10:35 AM <__ice9#6039> That will be mainly dependent on your ampoule and on how willing you are to risk breaking it 05-Feb-20 10:35 AM <__ice9#6039> If you use commodity quartz tubing and just seal the bottom of the tube, then you don't have to care so much about the breaking risk 05-Feb-20 10:35 AM <__ice9#6039> So you could do some experiments 05-Feb-20 10:35 AM <__ice9#6039> Sealing the bottom of a quartz tube can be done with a fairly strong oxyhydrogen torch, or oxy-propylene or oxyacetylene 05-Feb-20 10:35 AM <__ice9#6039> It's easiest if you just blast a section in the middle while the tube is being held vertically and then twist to pinch it shut 05-Feb-20 10:37 AM the raw materials cost on the LaBr3/CeBr3 side is a bit high compared to La/Ce prices...i wonder why. 05-Feb-20 10:37 AM <__ice9#6039> Bromides 05-Feb-20 10:37 AM i know bromine is a pain to work with but it does not seem that bad 05-Feb-20 10:38 AM <__ice9#6039> If you can figure out a clean way to do the salt metathesis then you could make your own 05-Feb-20 10:38 AM <__ice9#6039> I haven't looked into this personally though 05-Feb-20 10:38 AM <__ice9#6039> You could also melt down damaged crystals bought cheaply online 05-Feb-20 10:39 AM but then you're stuck on the Czochralski process. 05-Feb-20 10:39 AM good luck finding broken/damaged LaBr3 crystals 05-Feb-20 10:39 AM <__ice9#6039> ... why? Grind it to powder, put it in quartz, zone melt 05-Feb-20 10:39 AM <__ice9#6039> Yeah that's the issue 05-Feb-20 10:39 AM i have not seen any at all 05-Feb-20 10:39 AM but it's not just LaBr3, it's LaBr3:Ce 05-Feb-20 10:39 AM doping is important 05-Feb-20 10:39 AM yes i just didnt want to type that out each time 05-Feb-20 10:39 AM <__ice9#6039> Yes I thought that was the desired product though? 05-Feb-20 10:39 AM <__ice9#6039> Yeah exactly 05-Feb-20 10:40 AM oh and it's highly hygroscopic 05-Feb-20 10:40 AM just for the added flair of fun. 05-Feb-20 10:40 AM <__ice9#6039> Not an issue at 800C 05-Feb-20 10:40 AM until you cool it 05-Feb-20 10:40 AM guess you can skip the LaBr3 too...and just do straight CeBr3? 05-Feb-20 10:40 AM <__ice9#6039> It cools in quartz inside an argon purged furnace 05-Feb-20 10:40 AM yeah you could 05-Feb-20 10:40 AM but isn't cebr3 white? 05-Feb-20 10:40 AM as in opaque 05-Feb-20 10:40 AM <__ice9#6039> Btw purify your argon with zeolites on the way into the furnace 05-Feb-20 10:41 AM yeah, cebr3 is a "grey to white solid" 05-Feb-20 10:41 AM <__ice9#6039> For my graphite furnace I actually made a hot metal powder scrubber to remove stray atmospheric gases as well 05-Feb-20 10:41 AM <__ice9#6039> But that's probably overkill here 05-Feb-20 10:41 AM https://www.dynasil.com/success-story/invention-of-cerium-bromide/ 05-Feb-20 10:41 AM interesting comparison chart 05-Feb-20 10:42 AM <__ice9#6039> Yeah the transparency as powder vs monocrystalline can differ obviously 05-Feb-20 10:42 AM <__ice9#6039> Alumina is white, sapphire is clear. Calcia-stabilized zirconia is grey or yellow, CZ is clear. Etc. 05-Feb-20 10:42 AM <__ice9#6039> Think about using ammonium bromide and maybe e.g. lanthanum carbonate if you want to prepare it from reagents 05-Feb-20 10:44 AM Ce:GAGG seems to have the best resolution 05-Feb-20 10:44 AM Thanks @Spirit exactly what we were looking for 05-Feb-20 10:44 AM no worries 05-Feb-20 10:45 AM <__ice9#6039> You could also use metallic lanthanum powder and hydrobromic acid pretty easily 05-Feb-20 10:45 AM <__ice9#6039> But you might need to make your own HBr by distilling a pile of sodium bromide under concentrated sulfuric acid, either into a chilled water bubbler if you want the concentrated kind, or just starting from an azeotropic solution in the distillation flask if you want the HBr azeotrope 05-Feb-20 10:46 AM with that said, NaI by itself is a scintillator 05-Feb-20 10:46 AM as is CsI 05-Feb-20 10:46 AM <__ice9#6039> Hmm yes 05-Feb-20 10:46 AM the former should be synthesizable 05-Feb-20 10:47 AM <__ice9#6039> Cesium is much more costly fwiw 05-Feb-20 10:47 AM yeah 05-Feb-20 10:47 AM which is ironic, because it's a lot cheaper when you buy small crystals 05-Feb-20 10:47 AM <__ice9#6039> You can use CsOH and HI and calcine it and then melt it 05-Feb-20 10:47 AM <__ice9#6039> But HI is more of a hassle to make than HBr 05-Feb-20 10:47 AM <__ice9#6039> And is pretty much unbuyable because it turns into iodine easily and apparently free iodine has some drug related uses 05-Feb-20 10:48 AM I can buy bottles of pure iodine at my local pharmacy 05-Feb-20 10:48 AM <__ice9#6039> But it's not very hard to buy free iodine so idk, regulatory nonsense 05-Feb-20 10:48 AM dissolved in etoh 05-Feb-20 10:49 AM <__ice9#6039> Sure, it's a U.S. issue mainly 05-Feb-20 10:49 AM The free Iodine in drig related things is used to generate HI, so that's also a no go. 05-Feb-20 10:49 AM <__ice9#6039> Though there are still lots of iodine tinctures here so idk 05-Feb-20 10:49 AM <__ice9#6039> Oh maybe I had it backward idk 05-Feb-20 10:50 AM The USA COTS Iodine tinctures like "povidone" one are notoriously hard to extract elemental iodine from. 05-Feb-20 10:50 AM This is by design to deter meth cooks. 05-Feb-20 10:50 AM <__ice9#6039> Anyway if you want to make HI, just boil KI in H3PO4 in a flask you don't care about. It will get etched very badly. 05-Feb-20 10:50 AM <__ice9#6039> You can buy Lugol's etc though 05-Feb-20 10:50 AM <__ice9#6039> And water purification is pure I2 crystals 05-Feb-20 10:50 AM <__ice9#6039> Can't use H2SO4 for this one because it oxidizes too strongly 05-Feb-20 10:50 AM <__ice9#6039> Ammonium iodide would probably work for a thermal salt metathesis though 05-Feb-20 10:50 AM <__ice9#6039> Actually yeah I'm pretty sure NH4I + CsOH --> NH3 + H2O + CsI after strong heating works fine 05-Feb-20 10:50 AM <__ice9#6039> Mind the ammonia fumes 05-Feb-20 10:50 AM <__ice9#6039> If you wanted thallium for doping, though, that gets a lot more dangerous 05-Feb-20 10:50 AM <__ice9#6039> It's pretty difficult to buy as well 05-Feb-20 11:01 AM yeah i try to avoid anything involving iodine compounds...too much of that and you end up on the not fun lists 05-Feb-20 11:02 AM https://www.ebay.com/itm/Element-81-Collectible-Element-of-the-Periodic-Table-Thallium-metal-10-grams/124071390156 05-Feb-20 11:02 AM herp derp 05-Feb-20 11:02 AM though they mostly just are watching for pure iodine 05-Feb-20 11:02 AM <__ice9#6039> That might actually be enough thallium to dope something 05-Feb-20 11:02 AM more than enough 05-Feb-20 11:02 AM enough to dope yourself 05-Feb-20 11:02 AM <__ice9#6039> Yeah I don't see why not 05-Feb-20 11:02 AM (please dont) 05-Feb-20 11:02 AM <__ice9#6039> LOL 05-Feb-20 11:02 AM yeah that's enough to dope a few hundred people into the ground 05-Feb-20 11:02 AM which is the bigger issue 05-Feb-20 11:03 AM <__ice9#6039> Badly timed late button click by me 05-Feb-20 11:03 AM is doping done with metallic elements? 05-Feb-20 11:04 AM <__ice9#6039> I think you would need to dissolve it in HI first 05-Feb-20 11:04 AM i think you generally need the dopant to be the same salt as your main one 05-Feb-20 11:04 AM <__ice9#6039> Or make thallium hydroxide and react with NH4I 05-Feb-20 11:04 AM <__ice9#6039> Yeah exactly 05-Feb-20 11:04 AM LaBr3 is doped with CeBr3 05-Feb-20 11:04 AM would assume that the iodides are similar 05-Feb-20 11:05 AM really? 05-Feb-20 11:05 AM wouldn't you end up with an excess of Br3? 05-Feb-20 11:06 AM the paper i linked before says "The starting materials were a mixture of LaBr3and CeBr3 pow-ders. Both LaBr3and CeBr3powders are 4N polycrystalline and anhydrous. The molar ratio of CeBr3to LaBr3is 3:97. The materials were charged in the quartz ampule. " 05-Feb-20 11:06 AM <__ice9#6039> Forbidden solder blobs 05-Feb-20 11:06 AM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/1580929564377-C8AD0.png 05-Feb-20 11:07 AM I wonder if you can avoid czochralski completely 05-Feb-20 11:07 AM for stuff with low enough melting points, absolutely seems the case 05-Feb-20 11:07 AM the bridgman method seems way more approachable 05-Feb-20 11:08 AM vacuum sealed ampoule 05-Feb-20 11:09 AM <__ice9#6039> https://patents.google.com/patent/US1728772A/en Poe's law 05-Feb-20 11:09 AM <__ice9#6039> I don't think it needs to be vacuum sealed if you just use pure enough argon 05-Feb-20 11:09 AM <__ice9#6039> And age your heating elements enough beforehand 05-Feb-20 11:09 AM <__ice9#6039> If you really really cared, you could use tungsten elements under argon at low temps to minimize vapors 05-Feb-20 11:09 AM <__ice9#6039> It has among the lowest vapor pressure curve of any conductive material 05-Feb-20 11:11 AM by vacuum sealed I mean the actual ampoule 05-Feb-20 11:11 AM with the source materials 05-Feb-20 11:13 AM <__ice9#6039> I know. I don't think that is necessary if you purge with enough argon 05-Feb-20 11:13 AM <__ice9#6039> I do think it would produce a better result, to a degree 05-Feb-20 11:13 AM <__ice9#6039> But it would also block outgassing of trace volatile impurities, like um water 05-Feb-20 11:13 AM <__ice9#6039> Sealing under vacuum while torching the ampoule is likely the best way 05-Feb-20 11:14 AM i think you have to have anhydrous salts before you charge the ampule 05-Feb-20 11:15 AM <__ice9#6039> Pure and anhydrous don't belong in the same sentence 05-Feb-20 11:15 AM <__ice9#6039> They will pick up stray humidity during handling 05-Feb-20 11:15 AM <__ice9#6039> Maybe work in Death Valley or something 05-Feb-20 11:15 AM yes ideally you work in a glove box with dry argon/nitrogen 05-Feb-20 11:15 AM charge the ampule 05-Feb-20 11:16 AM <__ice9#6039> But yeah you should start with the anhydrous forms and 05-Feb-20 11:16 AM <__ice9#6039> Yes exactly 05-Feb-20 11:16 AM then seal it quickly 05-Feb-20 11:16 AM <__ice9#6039> Ok burn a torch in a glovebox ^^ 05-Feb-20 11:16 AM i am not that adventurous haha 05-Feb-20 11:16 AM <__ice9#6039> It's impossible. 05-Feb-20 11:16 AM <__ice9#6039> Absent oxyfuel 05-Feb-20 11:16 AM A lot of the problems in this server are often solved by a glove box full of dry nitrogen 05-Feb-20 11:17 AM <__ice9#6039> That's probably true yes 05-Feb-20 11:17 AM <__ice9#6039> Anyway I think turning the furnace into a glovebox of dry argon is probably good enough.... 05-Feb-20 11:56 AM huh, ben krasnow's DIY SEM was done back in 2011, wow 05-Feb-20 11:56 AM i hadn't realized he'd been at this so long 05-Feb-20 11:59 AM <__ice9#6039> impressive 05-Feb-20 12:57 PM @mike crb https://www.mpja.com/mobile/Power-Supplies/departments/1/ 05-Feb-20 01:37 PM https://ieeexplore.ieee.org/document/6609039 woah 05-Feb-20 01:37 PM 1 torr from a micro fabricated pump 05-Feb-20 01:39 PM they made MEMS turbopumps. 05-Feb-20 01:39 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/789b9fdd6a37e399dede9dc610047438-4930C.png 05-Feb-20 01:39 PM nmz, that is a useful site will save that. Already got the one spirit sent tho 05-Feb-20 01:39 PM Do you have that paper 05-Feb-20 01:39 PM That’s incredible 05-Feb-20 01:39 PM the turbomolecular pump is not a paper 05-Feb-20 01:39 PM it's a military honeywell project that no info is available on 05-Feb-20 01:39 PM Ohhh 05-Feb-20 01:40 PM I wonder where you're supposed to put stators on those 05-Feb-20 01:40 PM or maybe at this point you don't need stators 05-Feb-20 01:40 PM I also wonder how you're supposed to spin that, and how fast 05-Feb-20 01:40 PM at that scale it probably has to be close to half a million rpm or something 05-Feb-20 01:48 PM the one I posted and the Honeywell turbo were apparently both for the same DARPA program 05-Feb-20 01:48 PM some really cool stuff besides those two in it 05-Feb-20 01:49 PM I think they're for satellite stuff 05-Feb-20 01:51 PM you can make molecules spin at like 10THz 05-Feb-20 04:18 PM Anyone here used an Edwards pump display terminal? 05-Feb-20 04:19 PM <__ice9#6039> Nope. I just used an EXDC and built a display box with the readouts from it 05-Feb-20 04:20 PM The display terminal uses XLR but apparently communicates over rs232 05-Feb-20 04:20 PM They sell cables that convert the xlr to dsub for another pump, but don’t offer it and list no commands for my pump 05-Feb-20 04:20 PM All I want to do is change the Ethernet settings 05-Feb-20 04:20 PM Because by default I can’t connect to the pump 05-Feb-20 04:23 PM <__ice9#6039> Huh 05-Feb-20 04:23 PM <__ice9#6039> Yeah I saw a full control box on eBay a while ago, but it was like $1200 and it turned out my pump already had an EXDC attached to it, so I didn't pursue further. As a result, mine just has an on/off switch, a velocity readout as a 0-10V gauge, and some kind of relay to allow controlling other system components when some velocity condition in the manual is met 05-Feb-20 04:25 PM It manually has the default IP of 0.0.0.0 and you need to display terminal to enable dhcp or something 05-Feb-20 04:25 PM <__ice9#6039> Oh that's really annoying 05-Feb-20 04:26 PM https://www.ebay.com/itm/EDWARDS-D37280700-PUMP-DISPLAY-TERMINAL/293252975906 05-Feb-20 04:26 PM And to use a crossover cable you have to buy their software or something 05-Feb-20 04:26 PM brand new for 70 bucks 05-Feb-20 04:26 PM not too bad 05-Feb-20 04:27 PM <__ice9#6039> http://www.saelig.com/product/SSDB9001.htm No idea whether these pins are the same, looks audio related 05-Feb-20 04:27 PM Tbh I mostly just want to avoid their bs 05-Feb-20 04:27 PM Making a cable is easy 05-Feb-20 04:27 PM It’s the commands that are the problem 05-Feb-20 04:27 PM <__ice9#6039> Then control it with a raspberry pi or something 05-Feb-20 04:27 PM Yeah but what commands 05-Feb-20 04:27 PM There’s no programmers manual 05-Feb-20 04:28 PM <__ice9#6039> On and off? Idk what other commands are supported? 05-Feb-20 04:28 PM Enabling dhcp 05-Feb-20 04:28 PM It’s an iGX600L, pretty fancy pump 05-Feb-20 04:29 PM <__ice9#6039> Oh I meant a pi for the networking stuff and power control 05-Feb-20 04:29 PM Everything about it is A+ except that there’s no way to enable DHCP without their extra accessory 05-Feb-20 04:29 PM <__ice9#6039> But maybe yours has more complicated physical commands than on/off and velocity readout 05-Feb-20 04:30 PM It’s basically just on, off, shutdown, immediate shutdown, run til crash 05-Feb-20 04:30 PM Run til crash is terrifying 05-Feb-20 04:31 PM <__ice9#6039> Yeah that's pretty odd 05-Feb-20 04:31 PM <__ice9#6039> What does that even do? 05-Feb-20 04:32 PM The pump has lots of internal sensors 05-Feb-20 04:32 PM Temperature / vibrations etc 05-Feb-20 04:32 PM It tells the pump to ignore them. 05-Feb-20 04:32 PM Like a good pump shuts off if it overheats 05-Feb-20 04:32 PM But if your process is more dangerous if it shuts off... then you would rather risk breaking the pump 05-Feb-20 06:17 PM <__ice9#6039> Ah yeah I see that makes sense 05-Feb-20 06:17 PM <__ice9#6039> It's water cooled though (I hope?) 05-Feb-20 06:17 PM <__ice9#6039> Mine is anyway and I think they usually are 05-Feb-20 06:17 PM <__ice9#6039> But it can't reach into the spinning rotor itself obviously 05-Feb-20 06:29 PM Yeah it’s huge water cooled beast 05-Feb-20 11:50 PM anyone in here replaced tip seals on an Edwards XDS 10 dry scroll pump before? 06-Feb-20 12:01 AM @nmz787 that note on cleaning cold cathode gauges is great to know. I'll have to get some micro-90 someday 06-Feb-20 12:01 AM looks like its about 16 bucks a litre in single bottle 06-Feb-20 12:02 AM cool, glad you like it 06-Feb-20 12:02 AM just came across it randomly and it seemed to come from a good source (author has sent me a bunch of tips on a mailing list in the past) 06-Feb-20 06:35 AM @nmz787 not Edwards, but several Agilent ones 06-Feb-20 09:21 AM @idmb how much scrubbing did you have to do? A YouTube video says use lint free cloth, then scotchbrite, then lint free cloth again, then compressed air.... All with a healthy helping of ethanol or isopropanol 06-Feb-20 09:32 AM Depends how good you want it to be, our results have varied from only getting down to double rated pressure (pumping a blank tube with a gauge) vs getting down about half below rated 06-Feb-20 09:38 AM I've got a pump specific replacement instruction, but it pretty much says as much as the one you just posted 06-Feb-20 09:38 AM A vacuum shop told my buddy this was unrepairable, but supposedly took them 2 weeks to reply about that, so I'm skeptical that they just weren't going to make much money on the work and didn't want to say they didn't want to do the job 06-Feb-20 09:38 AM Hoping with a good bit of work it might be at least 10x worse than rated pressure (it's rated at 45 mTorr, 450mTorr would be acceptable for this application) 06-Feb-20 10:50 AM that should be easy 06-Feb-20 10:50 AM we've made our own tip seals too 06-Feb-20 10:50 AM just clamping some of the material between sheet metal and waterjetting 06-Feb-20 10:50 AM anyways the scrubbing is not that important if you're going for that level of vacuum 06-Feb-20 10:50 AM poor alignment / whatever scrapes away the tip seals to the point where they don't do anything 06-Feb-20 11:50 AM hmm, I guess I'll hold off on getting a new seal kit then, and open it up first to make sure it isn't pitted or rusted or something 06-Feb-20 12:06 PM well the tip seals get destroyed if anything else is wrong 06-Feb-20 12:06 PM I've seen one where the inside of the scrolls looked like it was filled with sawdust 06-Feb-20 02:14 PM heh, the spec for crash torque on my turbo is 50kNm 06-Feb-20 02:15 PM wow 06-Feb-20 02:15 PM my EXT250 is only 620Nm 06-Feb-20 02:15 PM what's the inlet diameter on that thing? 06-Feb-20 02:23 PM ISO250 06-Feb-20 02:23 PM About 10” 06-Feb-20 02:23 PM ID 06-Feb-20 02:23 PM oh good gravy 06-Feb-20 02:23 PM well, have fun with that :D 06-Feb-20 04:06 PM <__ice9#6039> That's like structural bolt territory 06-Feb-20 04:08 PM a lot of my assembly is put together with 1"-8 bolts anyways 06-Feb-20 04:20 PM <__ice9#6039> Impressive 06-Feb-20 04:20 PM <__ice9#6039> The only time I even looked at those was for a contemplated isostatic pressing chamber 06-Feb-20 04:20 PM <__ice9#6039> I paused that project because of deformation being likely given density gradients over time within the separate phases during freezing though 06-Feb-20 04:20 PM <__ice9#6039> Am currently pursuing porous freeze casting and an ultra high temperature inert atmosphere graphite furnace instead 07-Feb-20 08:40 AM https://home.cern/news/news/experiments/using-lego-study-building-blocks-universe 07-Feb-20 08:48 AM Neat but a small laser cutter + acrylic solvent would probably have been easier ? 07-Feb-20 09:09 AM yeah but where's the fun in that? 07-Feb-20 09:09 AM Also from general experience CERN doesn't have many laser cutters lying around 07-Feb-20 09:14 AM Reminding me of this: https://www.nature.com/articles/s41598-019-55616-7 07-Feb-20 09:43 AM https://www.geekwire.com/2020/garage-space-station-voxas-mochii-electron-microscope-will-flying-high/ 07-Feb-20 09:58 AM i want one :9 07-Feb-20 10:05 AM I met that guy like 6 or 7 years ago. Seemed pretty cool. I'm also pretty sure @AdamMcCombs has a nonzero level of involvement with that project. 07-Feb-20 11:51 AM Joined the server. 07-Feb-20 11:53 AM Hi Beowulf! 07-Feb-20 11:53 AM Hi! 07-Feb-20 11:53 AM Fancy seeing you here! 07-Feb-20 11:54 AM Ikr such a coincidence 07-Feb-20 11:58 AM I remember when they just announced it and everyone was thinking it's a scam that could never work 07-Feb-20 11:58 AM (small company coming out of nothing and building a micro SEM, you can see why) 07-Feb-20 11:58 AM But then the project didn't die and now they're manufacturing small SEMs 07-Feb-20 12:02 PM I wonder if they use a vacuum pump or just vent the chamber to space? 07-Feb-20 12:03 PM forepumping will probably vent to space 07-Feb-20 12:03 PM In fact high vacuum too 07-Feb-20 12:03 PM Since at 400km you're around -5? 07-Feb-20 12:05 PM Venting to space would mean letting some oxygen out of the ISS... I don't know how paranoid they get about that... 07-Feb-20 12:05 PM They have air locks? 07-Feb-20 12:05 PM They do, with pumping 07-Feb-20 12:05 PM but I don't think venting a few sccm is a big issue 07-Feb-20 12:05 PM Could always email them and ask :P 07-Feb-20 12:06 PM Alternatively don't vent the airlock and just yeet the SEM into a different orbit 07-Feb-20 12:06 PM The first SEM Satellite 07-Feb-20 12:06 PM with a really long ethernet wire 07-Feb-20 12:27 PM I am now in possession of an Edwards XDS10 dry scroll pump, in potentially unusable condition... Gotta open it up to check things out and then will post some pics here 07-Feb-20 12:32 PM @nmz787 I have one as well, though it's in reasonably good operating condition. Only 35,000 hours on it! 07-Feb-20 12:38 PM Hmm, is there any memory in it to record the hours? 07-Feb-20 12:38 PM The exhaust port has some rust on it, but it appears to only be on the outside not inside 07-Feb-20 12:38 PM We'll see what the scrolls look like soon 07-Feb-20 12:53 PM It has a mechanical hour meter 07-Feb-20 02:59 PM <__ice9#6039> @Mason_Yu paper on plasma windows showing the device construction clearly enough to build something equivalent 07-Feb-20 02:59 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/namba2018-442A7.pdf 07-Feb-20 02:59 PM <__ice9#6039> Looks like they are just powered by what amounts to a modified TIG welder 07-Feb-20 03:00 PM I believe I've seen that somewhere already, but haven't read it in-depth yet 07-Feb-20 03:00 PM <__ice9#6039> This example needs about 2L/min argon though. Not so great if it's deuterium 07-Feb-20 03:10 PM <__ice9#6039> @Mason_Yu I also found the actual paper from which the Wikipedia article obtained its diagram, but the power requirements are quite unreasonable and could easily be a major proportion of total device power usage. 07-Feb-20 03:10 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/vijvers2010-59B27.pdf 07-Feb-20 03:10 PM <__ice9#6039> Nonetheless, it's another buildable example, maybe could be scaled down, and this one gets the cathode out of the way of the tube 07-Feb-20 03:11 PM Oh yeah, I was actually talking to the CEO of Phoenix at a conference and he mentioned the power and cooling was a big problem when they were looking at plasma windows 07-Feb-20 03:41 PM Does anyone know about brazing diamond to metal or sealing it in glass? 07-Feb-20 03:41 PM I'm looking into x-ray windows, and if I do attempt to manufacture my own, I'd rather avoid beryllium altogether 07-Feb-20 03:41 PM Also interested in ceramic to metal seals 07-Feb-20 03:57 PM <__ice9#6039> Where would you obtain diamond panels that large? 07-Feb-20 03:57 PM <__ice9#6039> Polycrystalline CVD ones should be ok at least 07-Feb-20 03:57 PM <__ice9#6039> But that size is still pretty uncommon 07-Feb-20 03:58 PM Kinda answered that question 07-Feb-20 03:58 PM You can get CVD rectangles from 1x1 to ~20x20mm 07-Feb-20 03:58 PM I would directly evaporate tungsten onto the diamond on the vacuum side to make a high resolution transmission tube 07-Feb-20 03:58 PM http://www.diamond-materials.com/EN/products/cvd_for_xray/xray_targets.htm 07-Feb-20 03:58 PM It's a real thing used by quite a few companies 07-Feb-20 03:58 PM Perhaps the diamond can be used as purely mechanical and thermal support, while the tungsten layer would act as both the anode, interconnect, and high vacuum seal? 07-Feb-20 04:22 PM <__ice9#6039> I posted some stuff about ceramic to metal brazing in either #resources or #machining, not sure which, try search 'brazing' 07-Feb-20 04:22 PM The ultrasonic bit? 07-Feb-20 04:23 PM <__ice9#6039> That's an interesting approach-- diamond is indeed fairly x-ray transparent, as is ordinary graphite 07-Feb-20 04:23 PM <__ice9#6039> That was part of it but I also posted specific alloys 07-Feb-20 04:23 PM <__ice9#6039> Why not just use graphite? Too porous? Even if coated? 07-Feb-20 04:23 PM Hm... why not.. that's a good question, why not? 07-Feb-20 04:23 PM I suppose you'd need way too thick of a tungsten layer to be UHV-tight? 07-Feb-20 04:25 PM <__ice9#6039> Hmm or maybe try glassy carbon 07-Feb-20 04:25 PM It would almost kind of defeat the purpose of a thin tungsten layer 07-Feb-20 04:25 PM Since the reason it's thin is because it makes a much finer emission spot 07-Feb-20 04:26 PM <__ice9#6039> You can make glassy carbon objects by casting phenol-formaldehyde novolac resin (motorcycle fuel tank sealant, Bakelite precursor) in a silicone or similar mold, and then firing it very very slowly to 1200C in an argon atmosphere 07-Feb-20 04:26 PM Not particularly easy 07-Feb-20 04:26 PM <__ice9#6039> Glassy carbon is much less porous than graphite, thought there is still a little bit of porosity 07-Feb-20 04:26 PM <__ice9#6039> Well you can also buy it from Russians 07-Feb-20 04:26 PM That I can do 07-Feb-20 04:26 PM As I happen to speak Russian 07-Feb-20 04:27 PM <__ice9#6039> Like buy a glassy carbon crucible cover 07-Feb-20 04:27 PM <__ice9#6039> I assumed as much 07-Feb-20 04:27 PM <__ice9#6039> One of the groups producing some fairly good quality glassy carbon objects ships from Russia 07-Feb-20 04:27 PM <__ice9#6039> Check 'glassy carbon crucible' on eBay 07-Feb-20 04:28 PM no results 07-Feb-20 04:28 PM <__ice9#6039> I am not sure how easy it is to metalize compared to diamond but I suspect it can be done with sputter coating 07-Feb-20 04:28 PM <__ice9#6039> May have been 'vitreous carbon' 07-Feb-20 04:28 PM <__ice9#6039> Same thing 07-Feb-20 04:28 PM same, no results 07-Feb-20 04:29 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_20200207-182849-01BFD.png 07-Feb-20 04:29 PM links? 07-Feb-20 04:30 PM https://www.ebay.com/itm/Glassy-carbon-vitreous-graphite-Sigradur-G-crucible-50-mL/113631019089 07-Feb-20 04:30 PM <__ice9#6039> Seller suntehnik_ilya https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.com%2Fulk%2Fitm%2F113631019089 07-Feb-20 04:30 PM <__ice9#6039> Lol 07-Feb-20 04:30 PM lol they ship everywhere except the CIS and some asian countries 07-Feb-20 04:30 PM <__ice9#6039> These are just crucibles but if you message the seller they can probably make other stuff and send to you 07-Feb-20 04:30 PM <__ice9#6039> Listings mentioned custom and other sizes 07-Feb-20 04:31 PM They're incredibly thick 07-Feb-20 04:31 PM You'd need ~20-100um thick windows 07-Feb-20 04:31 PM <__ice9#6039> Alternately, you can always just build an argon furnace out of a stockpot and Kaowool and refractory cement with a Kanthal element 07-Feb-20 04:31 PM <__ice9#6039> Ok that's harder 07-Feb-20 04:31 PM <__ice9#6039> I figured 1mm or so since it's just carbon anyway but 07-Feb-20 04:32 PM You can buy diamond windows from china with these thicknesses 07-Feb-20 04:32 PM I guess 1mm could work too 07-Feb-20 04:32 PM <__ice9#6039> Hmm then I guess that might be a better option 07-Feb-20 04:32 PM <__ice9#6039> I have no idea what a diamond window that large and thin costs though 07-Feb-20 04:32 PM $30 to $300 07-Feb-20 04:32 PM depending on how nice the seller is 07-Feb-20 04:32 PM <__ice9#6039> I would have guessed $300 07-Feb-20 04:32 PM I should have a quote, hang on 07-Feb-20 04:32 PM <__ice9#6039> $30 sounds like the usual fake Alibaba list price 07-Feb-20 04:32 PM <__ice9#6039> Then they quote you 10x higher if they even respond at all 07-Feb-20 04:34 PM Ah, I didn't get anywhere with the seller 07-Feb-20 04:34 PM I'd be interested in some cheap CVD diamond windows/plates if they are actually $30 07-Feb-20 04:34 PM They kept asking for what I was going to use it for and trying to suggest random crap 07-Feb-20 04:34 PM http://usapplieddiamond.com/products/detectors/ 07-Feb-20 04:34 PM These are unrelated but pretty neat 07-Feb-20 04:34 PM Waaaaaaay too expensive though 07-Feb-20 04:37 PM They're usually tiny though @__ice9 07-Feb-20 04:37 PM 1x1 to 5x5mm 07-Feb-20 04:38 PM I'm almost tempted to contact Applied Diamond for a quote on their diamond membrane/foil 07-Feb-20 04:38 PM Then you get a quote with 5 digits and their contacts go into a blacklist 07-Feb-20 04:39 PM <__ice9#6039> I kind of want a diamond CVD furnace but it would be probably too time consuming of a project 07-Feb-20 04:39 PM Their detectors are expensive, but not 5 digit expensive 07-Feb-20 04:39 PM <__ice9#6039> Yeah 07-Feb-20 04:39 PM But MOQ 07-Feb-20 04:39 PM <__ice9#6039> Yep 07-Feb-20 04:39 PM It's 1 07-Feb-20 04:39 PM Well actually I don't know about the foils, but they will sell you one $750 detector 07-Feb-20 04:40 PM ouch 07-Feb-20 04:41 PM It's really not super useful for hobbyists unless you've got a personal LINAC 07-Feb-20 04:41 PM <__ice9#6039> Diamond CVD is basically a light gas flow of methane and acetylene and sometimes hydrogen into a microwave emission plasma or arcjet onto a water cooled molybdenum platform, optionally also illuminated by a frequency tuned CO2 laser to destabilize the acetylene 07-Feb-20 04:41 PM <__ice9#6039> It has to be temperature controlled 07-Feb-20 04:41 PM I am interested to see if it's possible to do at home 07-Feb-20 04:41 PM Seems like the purity of everything is important as well 07-Feb-20 04:41 PM Like you have to use special windows on your chamber... etc. 07-Feb-20 04:42 PM <__ice9#6039> But if you can do that, you can grow diamond straight onto molybdenum at anywhere from 10-200μm/hour 07-Feb-20 04:42 PM <__ice9#6039> And it can be annealed 07-Feb-20 04:42 PM <__ice9#6039> If you have a good seed crystal, you can even use CVD to extend it, making a larger monocrystalline diamond 07-Feb-20 04:42 PM <__ice9#6039> The main purity issue is deciding whether or not to allow any nitrogen 07-Feb-20 04:43 PM Monocrystaline isn't even required here 07-Feb-20 04:43 PM <__ice9#6039> Nitrogen can speed up the process further, but it also imparts a yellow or brown color 07-Feb-20 04:43 PM <__ice9#6039> Yeah I know but it is nice for some things 07-Feb-20 04:43 PM <__ice9#6039> I mean who wouldn't want to be able to grow a diamond the size of a paperweight in their living room 07-Feb-20 04:43 PM <__ice9#6039> I saw one example of a polycrystalline CVD film over 100mm diameter and several mm thick from some German university group 07-Feb-20 04:43 PM <__ice9#6039> It can be done 07-Feb-20 04:43 PM <__ice9#6039> Making it really wide is actually tricky because the microwave plasma region needs to be wider than usual 07-Feb-20 04:43 PM <__ice9#6039> 50mm is not too hard, 250mm is quite hard 07-Feb-20 04:43 PM <__ice9#6039> Papers exist about that too, but I would be happy with only 50mm ^^ 07-Feb-20 04:43 PM <__ice9#6039> But yeah annealing necessary 07-Feb-20 04:43 PM <__ice9#6039> Under argon or vacuum 07-Feb-20 04:43 PM <__ice9#6039> True of many high temp crystal growth processes with temperature gradients 07-Feb-20 04:43 PM <__ice9#6039> Speaking of which, apparently you can even anneal Verneuil process sapphires 07-Feb-20 04:43 PM <__ice9#6039> So apparently you can anneal pretty much anything lol 07-Feb-20 04:43 PM <__ice9#6039> Those are notorious for their extreme internal stresses, about as bad as Prince Rupert's drops 07-Feb-20 04:58 PM Does not do justice for how annoying this noise is 07-Feb-20 04:58 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/video0-A42FB.mov 07-Feb-20 05:06 PM oops should be posted in voiceposting 07-Feb-20 05:18 PM http://www.shuosong.com/English/productshow.asp?id=37 07-Feb-20 05:18 PM speaking of x-ray seals 07-Feb-20 05:18 PM hm. 07-Feb-20 05:18 PM they even make SDD cans 07-Feb-20 05:18 PM http://www.shuosong.com/English/productshow.asp?id=41 07-Feb-20 05:18 PM And copper brazed diamond windows! 07-Feb-20 05:18 PM http://www.shuosong.com/English/productshow.asp?id=47 07-Feb-20 05:24 PM I just sent in an inquiry on their Chinese site to ask for a catalog and a quote on some of their beryllium window products 07-Feb-20 05:55 PM Of course, you can do that :P 07-Feb-20 06:05 PM I got a little trigger happy on ePay and, long story short, there's a fancy new soldering station coming tomorrow. 07-Feb-20 07:56 PM I found an interesting other technique 07-Feb-20 07:56 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/file-96028.png 07-Feb-20 07:56 PM Instead of making the entire transmission target the target, you deposit a tiny blip of actual target material on a substrate, and you can totally do that even with a home sputtering/evap setup and a basic litho target 07-Feb-20 07:56 PM What if the substrate was carbon(glassy or diamond) instead? 07-Feb-20 07:56 PM You'd get almost no x-rays outside the target 07-Feb-20 07:56 PM @__ice9 07-Feb-20 07:56 PM picture is from this paper 07-Feb-20 07:56 PM https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0156224 07-Feb-20 10:03 PM I found a very fascinating channel 07-Feb-20 10:03 PM https://www.youtube.com/channel/UC26YLK0OEbLB3TCYxGh8xVQ 07-Feb-20 10:10 PM @Conmega @Nixie you guys might be interested in the maskless litho system he built 07-Feb-20 10:10 PM He got great results with not that much effort 07-Feb-20 10:21 PM cool thanks, will check it out 07-Feb-20 10:21 PM ah heh his little x-y stage is basically the exact same size as one I got at the hamfest recently 07-Feb-20 10:26 PM the way he built the optical path is interesting to me 07-Feb-20 10:26 PM just ditched absolutely everything but the dmd+drive 07-Feb-20 10:26 PM yea makes a lot of sense, removes the color stuff and simplifies the optical path 08-Feb-20 12:43 AM @Spirit very nice find! 08-Feb-20 12:43 AM I can't remember if the DMD I hacked to work without the colorwheel is HD or not 08-Feb-20 12:43 AM Ah, no 1024*768 08-Feb-20 12:49 AM Joined the server. 08-Feb-20 05:22 AM Great channel. Nice find Spirit 08-Feb-20 05:22 AM For DMD fun I just went with one of the TI dev kits. 08-Feb-20 05:37 AM Yeah nice find, subscribed. 08-Feb-20 05:48 AM I have an older 1024x768 DLP projector slated for teardown and hacking... but the limitation in terms of stitching precision leaves me concerned since obviously 1024x768 is not a lot of masking data... probably want to stitch a few of those together for anything useful. 08-Feb-20 05:48 AM Which is why I'm more-so leaning to seeing how much pain e-beam litho will be with my second "junker" SEM 08-Feb-20 05:48 AM but I still need to do cooling flush, hookup, get a roughing pump on it, and check the diff pump... 08-Feb-20 05:54 AM Should look in to using the DMD for beam steering and shaping. Can do very neat stuff using it in the diffraction regime. 08-Feb-20 08:49 AM you guys have a favorite table/mounting for vacuum stuff (bell jar on top, everything else below)? something small, perhaps 50x50cm or even smaller 08-Feb-20 08:52 AM I tend to use 19" racks for that 08-Feb-20 08:52 AM cool 08-Feb-20 08:52 AM with some particle board ontop 08-Feb-20 08:54 AM i'll take a look at racks, thanks 08-Feb-20 08:55 AM 8020 everything 08-Feb-20 08:55 AM 8020? 08-Feb-20 08:55 AM sounds expensive 08-Feb-20 08:55 AM no I just don't know what that is 08-Feb-20 08:55 AM sounds like an aluminium alloy?= 08-Feb-20 08:56 AM 80 20 aluminum extrusion t-slots 08-Feb-20 08:56 AM ahh 08-Feb-20 08:56 AM yep, expensive 08-Feb-20 08:56 AM old racks can be had for cheap 'tho 08-Feb-20 08:57 AM will check out craigslist 08-Feb-20 09:02 AM Not that expensive. Especially if you make the brackets and whatnot yourself out of the bulk extrusion profiles. 08-Feb-20 09:02 AM e.g https://8020.net/8621.html https://8020.net/25-8217.html 08-Feb-20 09:59 AM Btw one of the neatest things about using a DMD for beam steering is discrete positioning and splitting the beam into multiple focal points. E.g. you dont have to pass through B when going from A to C 08-Feb-20 09:59 AM You'd think I was talking about just projecting part of the beam, but it's more so that you display a computer generated hologram and the beam interferes with itself to produce the foci 08-Feb-20 10:01 AM @Metanoic you're right, not as bad as i thought it'd be 08-Feb-20 10:57 AM Branded 8020 costs a lot, my chamber frame was ~$1800, optical table enclosure was ~$1500 (anodized), and we have a drop ceiling made of it which was a bit more than that but built over a decade so I don’t have a good price in mind 08-Feb-20 10:57 AM (Built to order with anchors etc) 08-Feb-20 10:57 AM You get like an order of magnitude below that if you just buy off brand and cut it yourself 08-Feb-20 11:08 AM Oh also buying used stuff that happens to be made of 8020 08-Feb-20 11:25 AM Yea I just buy 108" lengths (longest UPS will ship without extra fees) and cut to size using a miter saw. 08-Feb-20 11:25 AM Couldn't decide on shelf arrangement for my office so wound up screwing half profiles into studs and doing modular shelving. 08-Feb-20 11:25 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20190404_060400-82DBF.jpg 08-Feb-20 12:36 PM That is a very clean lab 08-Feb-20 01:18 PM <__ice9#6039> @Spirit yes, I agree about sputter coating target material onto carbon for x-ray transparency. 08-Feb-20 01:38 PM Sounds like you'd be the one to try it @__ice9 08-Feb-20 01:38 PM with your gear 08-Feb-20 01:38 PM :P 08-Feb-20 02:26 PM is there any type of pump that can take 7bar at inlet? 08-Feb-20 02:28 PM I highly doubt it :P 08-Feb-20 02:29 PM what about something with a vent valve 08-Feb-20 02:29 PM what is causing the 7 bars? 08-Feb-20 02:29 PM that just lets out the high pressure but doesn't break 08-Feb-20 02:29 PM overpressure from a purge? 08-Feb-20 02:29 PM no, a different pump 08-Feb-20 02:29 PM that edwards pump spikes the exhaust to several bar "but no more than 7 bar" 08-Feb-20 02:29 PM upon turn on 08-Feb-20 02:30 PM exhaust? 08-Feb-20 02:30 PM yeah 08-Feb-20 02:30 PM don't you want that to... exhaust? 08-Feb-20 02:31 PM at really high gas loads, they said lowering the exhaust pressure can help the pumping speed 08-Feb-20 02:31 PM I just don't really see an easy way to do that 08-Feb-20 02:31 PM other than expansion + fan 08-Feb-20 02:34 PM you could always try forepumping it with a disposable forepump 08-Feb-20 02:34 PM tautology 08-Feb-20 03:00 PM there are a few people in california here, right? 08-Feb-20 03:00 PM @Metanoic nice setup! 08-Feb-20 03:21 PM Think there are a couple others... I am at least 08-Feb-20 04:13 PM <__ice9#6039> @Spirit perhaps someday, depends on various factors 08-Feb-20 04:13 PM <__ice9#6039> Glassy carbon I should be able to make, though. Carbonization furnace is pretty much done as of this afternoon, pending some possible improvements to the exhaust system. PF novolac doesn't release much hazardous gas anyway though, so a test run outside is probably ok while addressing that. 08-Feb-20 04:16 PM I wonder if there any other non-xraying materials you can use instead of it 08-Feb-20 04:16 PM aside from something dumb like lithium 08-Feb-20 04:16 PM <__ice9#6039> That reminds me, I need some ducting for the alternative exhaust converter insulated housing 08-Feb-20 04:17 PM Li is 0.53, Be is 1.85 08-Feb-20 04:17 PM Oh, interesting 08-Feb-20 04:17 PM Calcium? 08-Feb-20 04:17 PM Magnesium! 08-Feb-20 04:17 PM Mg is 1.74, carbon is 2.26 08-Feb-20 04:17 PM why isn't Mg foil used? 08-Feb-20 04:17 PM on that note, why isn't stuff like polyimide? 08-Feb-20 04:17 PM well, aside from conductivity.. 08-Feb-20 04:33 PM <__ice9#6039> Thin film polymers are often used as x-ray windows yes 08-Feb-20 04:33 PM <__ice9#6039> Well for detectors anyway 08-Feb-20 04:33 PM <__ice9#6039> I don't know whether they would survive the flux at the tube aperture for long 08-Feb-20 04:33 PM @Metanoic man I wish I could be that organized 08-Feb-20 04:34 PM The heat is my worry 08-Feb-20 04:34 PM So magnesium or calcium foil 08-Feb-20 04:34 PM As far as I can tell you can get 10 micron thick foils for both 08-Feb-20 04:34 PM <__ice9#6039> Magnesium is a reasonable idea, calcium less so 08-Feb-20 04:34 PM And up 08-Feb-20 04:34 PM @samy Oregon here... At least we touch Cali 08-Feb-20 04:34 PM But vacuum tightness 08-Feb-20 04:34 PM <__ice9#6039> No idea about gas permeability for either 08-Feb-20 04:35 PM This is definitely grounds for an experiment 08-Feb-20 04:35 PM Find some foil, figure out how to make a window, pump it down 08-Feb-20 04:35 PM <__ice9#6039> Magnesium is less reactive though 08-Feb-20 04:35 PM Far less 08-Feb-20 04:35 PM And cheaper? Should be 08-Feb-20 04:35 PM <__ice9#6039> Yes 08-Feb-20 04:35 PM <__ice9#6039> The only things I have even seen metallic calcium used for are refractory ceramic reductions and similar 08-Feb-20 04:35 PM <__ice9#6039> To extract exotic metals like thorium 08-Feb-20 04:36 PM It would be a really neat material to make windows out of 08-Feb-20 04:36 PM That doesn't actively try to kill you if you break it 08-Feb-20 04:38 PM <__ice9#6039> Sure but water attacks it 08-Feb-20 04:38 PM Oh, yeah, that's something I didn't think of 08-Feb-20 04:38 PM <__ice9#6039> Magnesium is humidity stable 08-Feb-20 04:38 PM Wait, that's what I meant 08-Feb-20 04:38 PM We're talking about magnesium 08-Feb-20 04:38 PM <__ice9#6039> Oh, yeah then I agree 08-Feb-20 04:38 PM <__ice9#6039> Wonder about prior literature 08-Feb-20 04:39 PM Now the mystery is - why is beryllium used instead of magnesium? 08-Feb-20 04:39 PM <__ice9#6039> Exactly 08-Feb-20 04:39 PM I can't find any literature based on a quick search 08-Feb-20 04:39 PM Maybe we should enlist science twitter 08-Feb-20 04:51 PM <__ice9#6039> Magnesium fluoride is a common vacuum optics window -- x-ray characteristics of fluorine? 08-Feb-20 04:52 PM Non-conductive 08-Feb-20 04:52 PM And sucks at heat transfer compared to metal 08-Feb-20 04:52 PM Remember that you'd need to pump at least a few watts into the 5-10um nub of W or Mo deposited onto it 08-Feb-20 04:54 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_20200208-185348-5ABF7.png 08-Feb-20 04:55 PM So Mg itself outgases? 08-Feb-20 04:55 PM <__ice9#6039> I am not sure if this is a vapor pressure issue or a gas permeability issue 08-Feb-20 04:55 PM <__ice9#6039> Beryllium is pretty refractory by contrast 08-Feb-20 04:55 PM <__ice9#6039> But if your power dissipation is pretty low.... 08-Feb-20 04:55 PM <__ice9#6039> It might still be ok 08-Feb-20 04:55 PM <__ice9#6039> Carbon is pretty obviously better in that area though 08-Feb-20 04:57 PM Beryllium still sucks and it's basically impossible to get ahold of in experimental quantities 08-Feb-20 04:57 PM Not to mention ridiculously expensive 08-Feb-20 04:57 PM $500 for a 5x5cm piece of 25um 08-Feb-20 04:57 PM <__ice9#6039> I'm merely drawing a distinction with the status quo 08-Feb-20 04:57 PM <__ice9#6039> I'm quite aware 08-Feb-20 04:57 PM <__ice9#6039> As in 'here is a contrast with the more common beryllium option that might explain why it is more common' 08-Feb-20 04:58 PM Hm 08-Feb-20 04:58 PM I can't find any exact details on magnesium itself outgassing 08-Feb-20 04:58 PM <__ice9#6039> https://www.excillum.com/products/metaljet/ 08-Feb-20 04:58 PM Surely it can't just start randomly evaporating on its own? 08-Feb-20 04:58 PM <__ice9#6039> Only thermally.... 08-Feb-20 04:58 PM <__ice9#6039> I mean vapor pressure in vacuum when heated 08-Feb-20 04:59 PM It'd probably get pretty hot 08-Feb-20 04:59 PM Maybe around 100C 08-Feb-20 04:59 PM <__ice9#6039> That's unlikely to matter 08-Feb-20 04:59 PM Yeah, so it shoooouldn't matter, should it? 08-Feb-20 04:59 PM <__ice9#6039> Especially under a tungsten coating 08-Feb-20 04:59 PM Not full tungsten 08-Feb-20 04:59 PM The coating of tungsten is just a tiny button 08-Feb-20 04:59 PM 5-10um in diameter, 10-100um thick 08-Feb-20 05:00 PM <__ice9#6039> Yes which is taking the hottest temps 08-Feb-20 05:00 PM Yeah 08-Feb-20 05:00 PM <__ice9#6039> Wait 5-10mm? 08-Feb-20 05:00 PM um 08-Feb-20 05:00 PM <__ice9#6039> Otherwise it's a spike 08-Feb-20 05:00 PM <__ice9#6039> ?? 08-Feb-20 05:00 PM No, just a tiny deposited button 08-Feb-20 05:00 PM microns, not mm 08-Feb-20 05:01 PM <__ice9#6039> 5-10um diameter, but 10-100um thick? So projecting off the plate like a needle? 08-Feb-20 05:01 PM I'm not sure how thick it would need to be, but relatively thin 08-Feb-20 05:01 PM I'm assuming around 1:1 to 1:5 aspect ratio 08-Feb-20 05:01 PM <__ice9#6039> I'm just pondering the thermal implications 08-Feb-20 05:02 PM It would need to be thin enough to make a sharp image, but thick enough to make enough x-rays 08-Feb-20 05:02 PM <__ice9#6039> It would definitely improve x-ray transmission though 08-Feb-20 05:02 PM <__ice9#6039> Yeah 08-Feb-20 05:02 PM I'm basing everything off this https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0156224 08-Feb-20 05:02 PM <__ice9#6039> Most of them will survive passing through a few dozen um of tungsten 08-Feb-20 05:02 PM Yeah, but you want it to be overwhelmingly tungsten x-rays 08-Feb-20 05:02 PM Not magnesium 08-Feb-20 05:03 PM <__ice9#6039> You could probably coat a somewhat wider area 08-Feb-20 05:03 PM <__ice9#6039> Yes I know 08-Feb-20 05:03 PM <__ice9#6039> That further argues in favor of a bigger button 08-Feb-20 05:03 PM But if the button is too big, you get a very large(comparatively) spot 08-Feb-20 05:03 PM And your microfocusness suffers 08-Feb-20 05:03 PM What I'm also seeing is that they are implying that the button is embedded into the material 08-Feb-20 05:03 PM That would be nigh impossible to make at home 08-Feb-20 05:04 PM <__ice9#6039> Why? 08-Feb-20 05:04 PM Just making a window would be hard, then you'd need to spin on resist, caaaaaaaaarefully expose a tiny dot, caaaaaarefully wash it off, and then put it through sputtering 08-Feb-20 05:04 PM <__ice9#6039> Embedding sounds difficult but not impossible 08-Feb-20 05:05 PM I wonder if embedding makes a big difference, versus just a protruding button 08-Feb-20 05:05 PM what are you wanting the beryllium for in "experimental quantities"? there are stupidly large pieces of it on ebay 08-Feb-20 05:05 PM <__ice9#6039> Not sure 08-Feb-20 05:05 PM <__ice9#6039> Lol it isn't wanted 08-Feb-20 05:05 PM @LRM not foil 08-Feb-20 05:05 PM ahhh 08-Feb-20 05:05 PM Quantity is irrelevant, all the experiments in the world can be done with like 5 grams of Be 08-Feb-20 05:05 PM but it needs to be <50um thick 08-Feb-20 05:05 PM and vacuum tight 08-Feb-20 05:05 PM <__ice9#6039> Yeah I don't really know what those pieces are for. Maybe collectors. I can't think of much safe that they could be used for. 08-Feb-20 05:06 PM could you sputter coat something with one of the ridiculous ebay items? thats all i can think of and i would not want to ever touch that vacuum system 08-Feb-20 05:06 PM The ebay items are worthless 08-Feb-20 05:06 PM They're huge metal chunks, not vacuum foil 08-Feb-20 05:06 PM Let's do the math from page 4 for Mg/W or Mg/Mo 08-Feb-20 05:06 PM Or... actually, why not Mg/Cu? Copper is a good conductor of both heat and electricity, and we don't really care about the ka/kb XRF lines since this is an imaging tube 08-Feb-20 05:06 PM Copper seems to be the third overall in terms of x-ray photons 08-Feb-20 05:06 PM And it looks like the target height is either 1um or 5um, with a diameter of 5um 08-Feb-20 05:06 PM Assuming we're not at the bleeding edge of science, a target of 10um is still absolutely awesome for DIY x-rays 08-Feb-20 05:06 PM Perhaps with a height of... 10 um as well? 08-Feb-20 05:06 PM A 10x10um dot seems relatively easy to do 08-Feb-20 05:06 PM Not sure how hard it would be to sputter tungsten or molybdenum versus copper 08-Feb-20 05:42 PM https://drivesncontrols.com/news/archivestory.php/aid/2629/104,000_rpm_appliance_motor_is_%60world_92s_fastest%60.html tiny turbopump 08-Feb-20 05:43 PM We talked about this a bit ago 08-Feb-20 05:53 PM I'm quite interested in making an atmosphere-surviving low power turbodragfanthing out of one 08-Feb-20 05:53 PM I wonder how fast I could spin their impeller up to in vacuum 08-Feb-20 05:53 PM 125krpm(new version) in air, 200k in vacuum? :P 08-Feb-20 05:53 PM if you can't use stators(and you really can't, these are far too consumery to cut slots in), beat it with sheer rpm 08-Feb-20 05:53 PM from what I can tell the actual impellers are injection molded plastic :( 08-Feb-20 07:21 PM Reading further into the point target paper: 08-Feb-20 07:21 PM For instance, when increasing the thickness of the substrate from 500μm to 800μm, the X-ray intensity decreased by approximately 5.8% 08-Feb-20 07:21 PM 800um... that's not even foil at that point! Just a disk! 08-Feb-20 07:21 PM I can buy Be rods in the right size... 08-Feb-20 07:21 PM I'm starting to have bad ideas. 08-Feb-20 07:21 PM Oh, and I totally goofed - it's not density we're looking for, it's atomic mass, since we don't want it to emit braking radiation. Which means magnesium is not useful here, with an atomic mass of 24.305, whereas beryllium is 9.0122 08-Feb-20 07:21 PM Lithium is better, but lithium would be a pain to process and would need a polyimide coating on it 08-Feb-20 07:21 PM Not to mention soft 08-Feb-20 07:21 PM Be, B, C are pretty much our only options 08-Feb-20 07:21 PM Boron foil seems to be a thing that exists 08-Feb-20 07:21 PM Perhaps... boron carbide? 08-Feb-20 07:21 PM But it's a semiconductor 08-Feb-20 08:01 PM Li-B alloy foil seems to be a common thing for batteries, I wonder how stable it is in air. 08-Feb-20 09:09 PM On the turbopump stuff @Spirit do we know if anyone has ever alleviated rotor radial load/tension by offloading onto a race curcumferential to the rotor? Or even "just" relying on primarily compressive strength? 08-Feb-20 09:10 PM What do you mean? 08-Feb-20 09:10 PM Like putting the outer edges of the turbo fins onto a ring with a bearing? 08-Feb-20 09:12 PM Yea, basically. Ideally not a rolling element cause of the even more insane speed. 08-Feb-20 09:13 PM You'd probably get away with it for a HUGE turbo 08-Feb-20 09:13 PM <20krpm 08-Feb-20 09:13 PM Yea I'm picturing 30krpm 12"dia type sizes 08-Feb-20 09:13 PM but if you get air inrush at that size, you have a kinetic grenade going off 08-Feb-20 09:13 PM no bearing will save you or it 08-Feb-20 09:14 PM If stacked for sure but if it was a single blade and a cup shaped race I'd think some flex would be allowed for 08-Feb-20 09:15 PM perhaps if you did some ridiculous overbuilding 08-Feb-20 09:15 PM see: Edwards EPX 08-Feb-20 09:15 PM they're basically atmospheric turbos 08-Feb-20 09:15 PM except it's... centrifugal? 08-Feb-20 09:15 PM https://dspace.vsb.cz/bitstream/handle/10084/114493/BIL0071_FMMI_B3923_3911R030_2016.pdf?sequence=1&isAllowed=y 08-Feb-20 09:15 PM Their construction is fascinating 08-Feb-20 09:15 PM Over built in what aspect particularly? 08-Feb-20 09:16 PM Imagine thick. Now triple that. Now double that. 08-Feb-20 09:16 PM And add some taper to make sure you comply with the laws of physics 08-Feb-20 09:16 PM Thick what? Rotor? Walls? 08-Feb-20 09:16 PM Rotor 08-Feb-20 09:16 PM Gotcha 08-Feb-20 09:16 PM Looking at the pdf 08-Feb-20 09:16 PM That document shows how the EPX is built inside 08-Feb-20 09:16 PM it's a magical maze of pumpery 08-Feb-20 09:16 PM holweck, turboey, centrifugaley, pure drag 08-Feb-20 09:16 PM all in one can 08-Feb-20 09:17 PM Nice 08-Feb-20 09:17 PM no backing is required either 08-Feb-20 09:17 PM you can just power it up and it will vent air on one end, be -5 on the other 08-Feb-20 09:17 PM downside? it takes 1-2kW continuous to run 08-Feb-20 09:19 PM Yeet 08-Feb-20 09:19 PM https://www.ebay.com/itm/Boc-Edwards-EPX180L-Turbo-Pump-Vacuum-A419-41-214/143526907302 08-Feb-20 09:19 PM you may be tempted :P 08-Feb-20 09:28 PM in any case.. my thoughts were around a standard rotor/stator sort of design, but using an annular rotor and stator to reduce the material requirements on the rotors, possibly allowing for a castable material (e.g. teflon, ABS, glass infused plastic, etc) to be used in the rotor 08-Feb-20 09:30 PM The issue is just the sudden inrush strength 08-Feb-20 09:30 PM You'd need... I don't know, consumable crash bumpers on each rotor section? 08-Feb-20 09:33 PM so the mechanism of failure in that situation is, what... not so much the pressure wave itself but the thrust the rotor blades would suddenly produce which causes them to twist/bend enough to impact the stator? 08-Feb-20 09:33 PM and just bend out of shape in general, yes 08-Feb-20 09:33 PM you're going from 0 thrust to several... I don't know, would it be tons at these angles? 08-Feb-20 09:33 PM some absurd value 08-Feb-20 09:33 PM If the rotors were perfectly rigid and could withstand the actual stresses, then the pumps would be pretty much indestructible 08-Feb-20 09:35 PM I think anything that stiff would have longevity issues from vibrations 08-Feb-20 09:35 PM yep 08-Feb-20 09:35 PM I get your point though 08-Feb-20 09:35 PM almost no vibrations in a turbo anyway 08-Feb-20 09:35 PM that sweet precision dynamic balancing 08-Feb-20 09:36 PM yea less is definitely better. they went past self-preservation a while ago IMO, and now it's a "it won't ruin your experiment with vibrations" 08-Feb-20 09:36 PM my mind wanders to using a small orifice that would highly restrict standard flow but also a mechanism to more or less collimate molecules during molecular flow to negate the small orifice.. or something 08-Feb-20 09:53 PM <__ice9#6039> Copper is a common x-ray tube target material, yes 08-Feb-20 10:04 PM @__ice9 have you built a vacuum brazing furnace yet? 08-Feb-20 10:04 PM I was thinking, since the beryllium thickness in those experiments is huge(over 500um), that makes it sort of feasible to just cut chunks off a rod and grind them to size 08-Feb-20 10:04 PM assuming you have awesome dust control and/or no will to live 08-Feb-20 10:24 PM can i just measure pressure on the interstage port of TMP instead of through the vacuum chamber? (waiting for controller before i can give it a go!) 08-Feb-20 10:25 PM the interstage port will give you interstage pressure 08-Feb-20 10:25 PM plug it and forget about it 08-Feb-20 10:25 PM (until you need an interstage port, and then you have one) 08-Feb-20 10:26 PM is that adjustable to match main port pressure? (just going for easiest setup) 08-Feb-20 10:27 PM no, it's a port that sits partially down the turbo path 08-Feb-20 10:27 PM hence, interstage 08-Feb-20 10:27 PM k 08-Feb-20 11:14 PM <__ice9#6039> >@__ice9 have you built a vacuum brazing furnace yet? @Spirit I'm not working on a uniform temperature vacuum furnace at the moment. The only vacuum furnace I have is a vacuum arc furnace I built, which is not even really a true vacuum furnace-- since it dumps in argon whenever the arc is running. 08-Feb-20 11:14 PM <__ice9#6039> I am currently finishing an inert-gas-flushed carbonization furnace though 08-Feb-20 11:14 PM <__ice9#6039> And after that will be my argon graphite furnace 08-Feb-20 11:15 PM From what I understand vacuum brazing is just a quartz tube with [????] heating and vacuum 08-Feb-20 11:15 PM <__ice9#6039> Well that's assuming whatever you are brazing fits into the tube.... 08-Feb-20 11:15 PM <__ice9#6039> I have a tube furnace. I haven't gotten around to trying to graft vacuum flanges onto a quartz tube yet though. 08-Feb-20 11:16 PM Well the x-ray tube head will be a small cylinder 08-Feb-20 11:17 PM <__ice9#6039> I decided a while ago that argon furnaces were usually more useful to me, since they can hit much higher temperatures due to the argon suppressing evaporation of the heating elements and refractory facings 08-Feb-20 11:17 PM <__ice9#6039> Huh? Mine is like 30cm x 30cm x 12cm lol 08-Feb-20 11:17 PM argon would probably work here 08-Feb-20 11:17 PM <__ice9#6039> My Russian XRF tube is about 6cm across also 08-Feb-20 11:17 PM <__ice9#6039> Argon usually works 08-Feb-20 11:17 PM <__ice9#6039> Unless you are trying to vacuum outgas melts to refine metals 08-Feb-20 11:17 PM <__ice9#6039> Vacuum remelting, zone refining, stuff like that 08-Feb-20 11:18 PM This would be a tiny tube 08-Feb-20 11:18 PM <__ice9#6039> That's usually better with induction though 08-Feb-20 11:18 PM Probably 30mm in diameter, 50-60mm long 08-Feb-20 11:19 PM <__ice9#6039> In vacuum 08-Feb-20 11:19 PM <__ice9#6039> Instead of tungsten in vacuum 08-Feb-20 11:19 PM <__ice9#6039> Also graphite is not a good idea in vacuum 08-Feb-20 11:19 PM <__ice9#6039> At least, not for the facing surfaces or heating elements 08-Feb-20 11:19 PM <__ice9#6039> So you end up needing tungsten/moly sheet metal 08-Feb-20 11:19 PM <__ice9#6039> Which is just horribly expensive in the quantities needed for radiative insulation 08-Feb-20 11:19 PM <__ice9#6039> I guess I have an ebeam project in some stage of work but that one is complex and I have no particular anticipated completion time for it 08-Feb-20 11:19 PM <__ice9#6039> That's a thermal vacuum furnace in some sense anyway 08-Feb-20 11:19 PM <__ice9#6039> I'm starting to wonder whether it's really any more useful than RF sputtering, though. At the time, I didn't really realize sputtering could do ceramics 08-Feb-20 11:19 PM <__ice9#6039> It can still be used to do stuff like make monocrystalline thoria though 08-Feb-20 11:19 PM <__ice9#6039> The PSU is a bit intimidating. 10kW 10kV. Complicated to build. Works in sim and components test good so far. Hit a snag modifying some transformers in the CW drive though and kind of stalled for a bit. 08-Feb-20 11:23 PM You can do ebeam welding! 08-Feb-20 11:24 PM <__ice9#6039> Will get around to that eventually 08-Feb-20 11:24 PM <__ice9#6039> Hmm I guess maybe 08-Feb-20 11:24 PM It's essentially a SEM out of control 08-Feb-20 11:24 PM <__ice9#6039> That needs a motorized stage and automated control though 08-Feb-20 11:24 PM Most modern e-beam welders actually have a SEM option 08-Feb-20 11:24 PM low mag 08-Feb-20 11:24 PM <__ice9#6039> That's pretty intriguing 08-Feb-20 11:24 PM https://www.youtube.com/watch?v=grzbTs69wuw 08-Feb-20 11:24 PM 0:42 is when they SEM it. 08-Feb-20 11:25 PM <__ice9#6039> I definitely wouldn't be capable of designing or building a SEM myself. It's all I can do to just create and control the ebeam itself. 08-Feb-20 11:25 PM A SEM and EBW are basically the same 08-Feb-20 11:25 PM One is just far more crude 08-Feb-20 11:25 PM It even does the fiber laser marker thing by marking using an ebeam 08-Feb-20 11:25 PM Which is just... cool 08-Feb-20 11:26 PM <__ice9#6039> Huh they are using really low power levels in that video 08-Feb-20 11:26 PM Mhm, for thin stuff 08-Feb-20 11:26 PM <__ice9#6039> That's only 600W and basically x-ray tube 60kV 10mA type stuff 08-Feb-20 11:26 PM <__ice9#6039> Got it 08-Feb-20 11:26 PM The downside: You also get the x-rays 08-Feb-20 11:26 PM Lots of em 08-Feb-20 11:27 PM <__ice9#6039> I know. Mine is only 10kV so the shielding was easy 08-Feb-20 11:27 PM <__ice9#6039> But yeah the flux is pretty absurd 08-Feb-20 11:27 PM <__ice9#6039> Like sterilizer level 08-Feb-20 11:27 PM I wonder if it's controlled as tightly 08-Feb-20 11:27 PM Surely at 60kv that glass window is basically a free suntan port 08-Feb-20 11:28 PM <__ice9#6039> In the video they are using a linear beam. Mine is designed around a surplus Temescal water cooled copper hearth with a 270 degree curved beam path and steering magnets. Keeps the resulting PVD vapors purer 08-Feb-20 11:28 PM <__ice9#6039> But the PSU could obviously run either. 08-Feb-20 11:28 PM <__ice9#6039> Yeah the giant glowing port in that video sketched me out 08-Feb-20 11:28 PM <__ice9#6039> I have to hope they were using lead glass.... 08-Feb-20 11:29 PM I totally want that chamber though 08-Feb-20 11:29 PM It looks awesome for lots of projects 08-Feb-20 11:29 PM <__ice9#6039> I agree 08-Feb-20 11:29 PM <__ice9#6039> I tend to make huge chambers out of thick stockpots and weld-on flanges though lol 08-Feb-20 11:30 PM heh 08-Feb-20 11:30 PM I can't do that at home 08-Feb-20 11:30 PM <__ice9#6039> I mean what else would a Temescal fit into lolol 08-Feb-20 11:31 PM heh 08-Feb-20 11:32 PM <__ice9#6039> https://en.wikipedia.org/wiki/Electron-beam_physical_vapor_deposition 08-Feb-20 11:32 PM This was very popular in the USSR 08-Feb-20 11:32 PM I've seen several educational films that show these 08-Feb-20 11:33 PM <__ice9#6039> Huh interesting 08-Feb-20 11:33 PM <__ice9#6039> Another example of something like that is induction skull crucible melting for making cubic zirconia 08-Feb-20 11:33 PM <__ice9#6039> Speaking of lead glass, I ordered some and am going to try to melt it down into a cylindrical shape and polish it into a viewport window cover. 08-Feb-20 11:33 PM <__ice9#6039> That's for the ebeam system as well 08-Feb-20 11:38 PM From what I understand it behaves closer to borosilicate in robustness 08-Feb-20 11:38 PM But you'll need annealing 08-Feb-20 11:39 PM <__ice9#6039> The facing surface is quartz, then a metal support ring, then I want this thick leaded glass cover, then there's a UV filter that goes over that. Then finally a welding goggle shade 08-Feb-20 11:39 PM <__ice9#6039> Yeah I assume by default that any hot worked ceramic needs to be annealed 08-Feb-20 11:39 PM <__ice9#6039> Cubic zirconia is a tragically underused material 08-Feb-20 11:40 PM I mean the lead glass 08-Feb-20 11:40 PM <__ice9#6039> I know. 08-Feb-20 11:40 PM <__ice9#6039> Was making a different point. 08-Feb-20 11:40 PM And now that I think about what I said, it might not be anything like borosilicate, because I was thinking about uranium 08-Feb-20 11:41 PM <__ice9#6039> Yeah I don't actually know. But I expect to read more about it during the window preparation process. 08-Feb-20 11:41 PM <__ice9#6039> Initially I was hoping to make float glass, but it turned out leaded glass dissolves large amounts of tin, so no. 08-Feb-20 11:41 PM Float it on mercury 08-Feb-20 11:41 PM :P 08-Feb-20 11:42 PM <__ice9#6039> That's just horrible 08-Feb-20 11:42 PM <__ice9#6039> I was thinking gallium maybe, but it's so expensive 08-Feb-20 11:42 PM <__ice9#6039> Don't want to risk contaminating my remaining 600g or so 08-Feb-20 11:42 PM Lithium? Sodium? Potassium? 08-Feb-20 11:43 PM <__ice9#6039> Too reactive 08-Feb-20 11:43 PM They're reactive but cheap 08-Feb-20 11:43 PM (er) 08-Feb-20 11:43 PM <__ice9#6039> Anyway I'm not trying to make soda glass ew 08-Feb-20 11:43 PM What about... lead? 08-Feb-20 11:43 PM Would it work? 08-Feb-20 11:43 PM <__ice9#6039> ... huh 08-Feb-20 11:43 PM <__ice9#6039> That's.. actually an interesting point. 08-Feb-20 11:43 PM <__ice9#6039> That's a very interesting point. 08-Feb-20 11:43 PM The fumes are toxic but it's not too reactive and you can melt it easily 08-Feb-20 11:44 PM <__ice9#6039> I don't care about that. I can do it outside with supplied air. 08-Feb-20 11:44 PM <__ice9#6039> And if it dissolves more into the melt, so what? I get more shielding. 08-Feb-20 11:44 PM Next up: DIY lead glass. 08-Feb-20 11:44 PM (lead salts in glass melt?) 08-Feb-20 11:44 PM <__ice9#6039> It boils pretty low so I will need to be patient waiting for squishy blobby glass on top to settle out, but I can just set the temperature control and come back in an hour 08-Feb-20 11:45 PM you can also leave it on the lead and you get annealing 08-Feb-20 11:45 PM <__ice9#6039> What's it going to do, dissolve more lead? Oxidize? Lol it's almost inert and the only major reaction likely is arguably useful 08-Feb-20 11:45 PM <__ice9#6039> Yep that was actually the plan for any kind of float glass 08-Feb-20 11:45 PM <__ice9#6039> Lead glass is just PbO in glass, not even kidding 08-Feb-20 11:45 PM though you'd want a very thick piece, or several thick pieces 08-Feb-20 11:46 PM <__ice9#6039> Yes that's the intent 08-Feb-20 11:46 PM <__ice9#6039> I bought some random lead crystal cheaply online and am going to repurpose it for my needs 08-Feb-20 11:46 PM <__ice9#6039> Actually it boils at 1750C so there is no issue at all. The process can run as normal. 08-Feb-20 11:46 PM <__ice9#6039> Graphite crucible 08-Feb-20 11:46 PM <__ice9#6039> Boron nitride releasing agent 08-Feb-20 11:46 PM <__ice9#6039> Hmm need a smaller crucible though. My current one is large. 08-Feb-20 11:46 PM <__ice9#6039> Wonder whether a metal one would work 08-Feb-20 11:46 PM <__ice9#6039> Temp is low enough to use CO2 shield gas for the crucible 08-Feb-20 11:46 PM <__ice9#6039> Don't do that above like 1000C 08-Feb-20 11:46 PM <__ice9#6039> 800C if you want to be safe 08-Feb-20 11:49 PM given how lead crystal is pressed in forms and stuff you probably could get it to the state where it is gummy in a crucible and then press it into your final dimensions/shape? 08-Feb-20 11:49 PM <__ice9#6039> But at like 700C it's fine 08-Feb-20 11:49 PM <__ice9#6039> Why bother if I can just float it and save myself having to do any polishing? 08-Feb-20 11:50 PM if it's a great surface(so no slag, you'll need purge) and it's perfectly still(left alone for a while) you should get a mirror surface 08-Feb-20 11:50 PM since that's how mirrors are made in the first place 08-Feb-20 11:50 PM <__ice9#6039> That's the idea 08-Feb-20 11:50 PM i am not sure the float glass thing will really work but i am totally open to being wrong 08-Feb-20 11:51 PM <__ice9#6039> Yeah speaking of which I should post the Brashear process to #resources 08-Feb-20 11:51 PM will lead crystal stick to molten lead? 08-Feb-20 11:55 PM <__ice9#6039> It should stick to the litharge layer which is why purge gas is desirable 08-Feb-20 11:55 PM <__ice9#6039> Softening temp is 600C though, so it should be removable while the lead remains molten. If there is any PbO left on the surface then I suppose I will just have to etch it off. But I will address that if it actually occurs. 09-Feb-20 12:23 AM <__ice9#6039> Acquired graphite crucible of appropriate size 09-Feb-20 02:26 PM hmm if i'm going to be doing sputtering and want to introduce argon to the chamber (bell jar), but I have the TMP mounted directly to a plate (ISO100) to the bell jar, how do I keep the Argon in there? can I turn off the TMP and valve it off at the mechanical pump? 09-Feb-20 02:26 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_2020-02-09_14.25.31-17204.png 09-Feb-20 02:28 PM yes, you just have to comply with its venting and gas load specifications 09-Feb-20 02:28 PM I'd place the 901p next to the BPG400, and either another 901p or just some random thermocouple where your current 901p is 09-Feb-20 02:28 PM you'll also want something between that 1/4" NPT and the chamber 09-Feb-20 02:28 PM a swagelok needle valve will work 09-Feb-20 02:28 PM you also really don't want a hose between your BPG400 and the chamber 09-Feb-20 02:28 PM the gauges have to be as close as possible to the chamber you're measuring 09-Feb-20 02:34 PM i see 09-Feb-20 02:37 PM also, remember: bumping the turbo while it's running greatly increases your chances of triggering turbo salad 09-Feb-20 02:37 PM bumping it physically? 09-Feb-20 02:38 PM yes 09-Feb-20 02:39 PM ok, i'll try to figure out mounting shortly 09-Feb-20 02:39 PM just bolt it to something big and heavy 09-Feb-20 02:42 PM i have a regulator on the argon tank, will that work instead of the needle valve? 09-Feb-20 02:42 PM why have the 901P and BPG400 next to each other, wouldn't i just need one in that spot? 09-Feb-20 02:44 PM oh yeah, the bpg400 is wide range 09-Feb-20 02:44 PM mixed it up with the other one 09-Feb-20 02:44 PM ahh 09-Feb-20 02:44 PM you don't want to have a length of gassy hose hanging freely connected to your chamber 09-Feb-20 02:44 PM i assume no one here has an EXT255H(i) CAD model? will draw one up otherwise to figure out spacing 09-Feb-20 02:44 PM oh i see 09-Feb-20 02:44 PM makes sense now, thanks 09-Feb-20 02:46 PM just model up a cylinder 20% bigger than an iso100 flange 09-Feb-20 02:46 PM k 09-Feb-20 02:46 PM tip: you can download 3d files for pretty much any vacuum thing from idealvac 09-Feb-20 02:46 PM I modeled my entire chamber by assembling things in inventor 09-Feb-20 02:49 PM ahh nice 09-Feb-20 02:49 PM that's great, thanks! will start ganking their models 09-Feb-20 02:53 PM <__ice9#6039> I swear everyone has this pump, it's hilarious 09-Feb-20 02:58 PM I don't! 09-Feb-20 02:58 PM the seller is being really slow with negotiating 09-Feb-20 03:55 PM For CAD, anything idealvac doesn’t have, lesker seems to have. I’ve also used some stuff from random forums 09-Feb-20 03:55 PM I have a cad model of the whole basement my lab is in 09-Feb-20 03:55 PM Had to do it to figure out storage Tetris 09-Feb-20 06:14 PM haha nice 09-Feb-20 06:14 PM yeah the other day i ended up figuring out how to rearrange my den with all the new stuff you've all gotten me excited by 09-Feb-20 06:14 PM didn't find a quick way to do it so just used a fusion360 sketch to draw out 2d layout and drag stuff around - does someone suggest another tool for room layout that's super quick to setup? 09-Feb-20 06:16 PM I guess you could do it in non-CAD 09-Feb-20 06:16 PM blender for example 09-Feb-20 06:25 PM I’m pretty comfy with solidworks so that’s all I’ve used 09-Feb-20 06:37 PM Just got the specs and price back for LiB @__ice9 09-Feb-20 06:37 PM $9000/kg EXW(with a MOQ of 1kg of course), and unstable in air 09-Feb-20 09:14 PM <__ice9#6039> Lolllll 09-Feb-20 09:14 PM <__ice9#6039> I think that stuff is hydrogen permeable too...? 09-Feb-20 09:14 PM <__ice9#6039> Might be a risk, not sure 09-Feb-20 09:14 PM <__ice9#6039> It's supposedly possible to make lithium nitride by direct reaction at high temperature. Borides are usually trickier though. Not sure in this case. Doesn't sound very suitable regardless though. http://www.sciencemadness.org/talk/viewthread.php?tid=33066 09-Feb-20 09:14 PM <__ice9#6039> What happened to the magnesium metallic window idea? 09-Feb-20 09:19 PM mixup of atomic mass versus density 09-Feb-20 09:19 PM magnesium is unsuitable 09-Feb-20 09:22 PM <__ice9#6039> Hmm I see. I had somewhat wondered, given Z. 09-Feb-20 09:22 PM <__ice9#6039> If you don't mind continuous pumping then personally I would just use carbon. 09-Feb-20 09:23 PM it's going to have to be sealed 09-Feb-20 09:23 PM so no cont pumping 09-Feb-20 09:26 PM <__ice9#6039> Hmm maybe lithium fluoride if you can keep it dry 09-Feb-20 09:26 PM needs to be a direct atmospheric to high vacuum transition for simplicity 09-Feb-20 09:26 PM <__ice9#6039> It isn't very strong though so the window must be pretty small 09-Feb-20 09:26 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/z04-73D71.gif 09-Feb-20 09:26 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/z03-5E7C3.gif 09-Feb-20 09:26 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/z09-A0A1C.gif 09-Feb-20 09:27 PM LiF can't be used since it won't survive atmospheric conditions 09-Feb-20 09:27 PM (within reason) 09-Feb-20 09:27 PM there needs to be some kind of ultra low molecular weight compound that could be used as a high vacuum, thermally conductive window 09-Feb-20 09:45 PM <__ice9#6039> Yeah it's called beryllium =P 09-Feb-20 09:45 PM and not deadly 09-Feb-20 09:47 PM <__ice9#6039> Boron carbide 09-Feb-20 09:47 PM <__ice9#6039> Boron nitride 09-Feb-20 09:47 PM <__ice9#6039> Diamond 09-Feb-20 09:47 PM <__ice9#6039> These all seem like options 09-Feb-20 09:47 PM boron carbide is basically unobtainium 09-Feb-20 09:47 PM boron nitride might work, but even less obtainium? 09-Feb-20 09:47 PM but neither of these are conductive, so the charges would build up on the anode and kill the tube in roughly no seconds 09-Feb-20 09:49 PM <__ice9#6039> I will be able to make it very soon. 09-Feb-20 09:49 PM <__ice9#6039> Boron nitride is available as powder all over the place, but solid crystals are rare, and you probably need the cubic kind which is even more rare. Basically very similar to diamond. 09-Feb-20 09:49 PM <__ice9#6039> Is there really a terrible problem with running a tiny trace wire to the target 09-Feb-20 09:49 PM <__ice9#6039> ? 09-Feb-20 09:51 PM yeah, it'd turn into an anode 09-Feb-20 09:51 PM <__ice9#6039> Ok so what about coating the entire inner window surface with graphite? 09-Feb-20 09:52 PM That... would work, except it'd need to be a rather extreme manufacturing step increase 09-Feb-20 09:52 PM both of these boron compounds are ceramics too 09-Feb-20 09:52 PM brazing those to metal would be interesting 09-Feb-20 09:54 PM how much heating are you anticipating will happen on the target during normal operation? 09-Feb-20 09:54 PM 1-10W 09-Feb-20 09:56 PM ah and that is on a 5-10um diameter spot? 09-Feb-20 09:56 PM yep... 09-Feb-20 09:57 PM i wonder how much heat those graphenic carbon window things could stand 09-Feb-20 09:57 PM <__ice9#6039> Also diamond isn't really ideal electrically 09-Feb-20 09:57 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/1581314203049-67410.png 09-Feb-20 09:57 PM <__ice9#6039> Diamond-like carbon might work though 09-Feb-20 09:58 PM all I can see is coatings 09-Feb-20 09:58 PM <__ice9#6039> It's usually used as a coating too 09-Feb-20 09:58 PM <__ice9#6039> Yeah so you can coat an insulator with it.... 09-Feb-20 09:58 PM <__ice9#6039> Like boron carbide 09-Feb-20 09:58 PM <__ice9#6039> Etc 09-Feb-20 09:58 PM <__ice9#6039> Nevermind it's also an insulator -___- 09-Feb-20 09:58 PM <__ice9#6039> Back to graphite it seems 09-Feb-20 10:00 PM can you grow monocrystals of carbon? 09-Feb-20 10:00 PM <__ice9#6039> Yeah they are called diamonds 09-Feb-20 10:00 PM .... you have a point 09-Feb-20 10:03 PM <__ice9#6039> Solid graphite meanwhile tends to be pretty porous. Glassy carbon is usually a bit better 09-Feb-20 10:03 PM Hm 09-Feb-20 10:03 PM <__ice9#6039> Not sure about bakelite or epoxy but likely not good enough either 09-Feb-20 10:03 PM the "graphenic carbon" windows in that paper i linked were vacuum tight according to the paper at least 09-Feb-20 10:03 PM <__ice9#6039> (other possible light element backing layers) 09-Feb-20 10:03 PM actually, that gives me an idea 09-Feb-20 10:03 PM but you have to grow it on a silicon wafer 09-Feb-20 10:03 PM take high vacuum epoxy 09-Feb-20 10:03 PM take a piece of graphite 09-Feb-20 10:03 PM and impregnate it partially 09-Feb-20 10:04 PM <__ice9#6039> Yeah I was contemplating that.... 09-Feb-20 10:04 PM <__ice9#6039> I don't know whether HV epoxy is merely low outgassing, though, or actually also low-permeability. 09-Feb-20 10:04 PM it'd create a low permeability matrix 09-Feb-20 10:04 PM <__ice9#6039> I mean if you can't actively pump it then any significant amount of permeability is non-viable 09-Feb-20 10:04 PM <__ice9#6039> That's an empirical question 09-Feb-20 10:05 PM now, the issue is: how in the hell can you impregnate something thicker than ethanol into graphite 09-Feb-20 10:05 PM <__ice9#6039> Very high pressure. 09-Feb-20 10:05 PM probably way beyond scuba compressors even 09-Feb-20 10:05 PM @LRM graphenic carbon would vaporize the moment you turn the ebeam on 09-Feb-20 10:06 PM <__ice9#6039> Hysol 1C only says 'low permeability to gases and vapors' 09-Feb-20 10:06 PM <__ice9#6039> I still think graphite coated boron carbide would work 09-Feb-20 10:07 PM boron carbide sheet is unobtainable 09-Feb-20 10:07 PM <__ice9#6039> It's a nightmare to machine it though 09-Feb-20 10:07 PM <__ice9#6039> Well, maybe not that bad but 09-Feb-20 10:07 PM <__ice9#6039> It's very very very hard and tough 09-Feb-20 10:08 PM considering machine tools are made out of it yeah 09-Feb-20 10:08 PM <__ice9#6039> It wears out a lot of diamond bits to make anything out of it 09-Feb-20 10:08 PM <__ice9#6039> It's better to sinter in the exact shape needed 09-Feb-20 10:09 PM so also pretty much unmanufacturable 09-Feb-20 10:12 PM <__ice9#6039> Best way would be to squash a disc of it with a bit of Bakelite resin powder in a 20 ton press or something, then fire to about 2400C 09-Feb-20 10:13 PM I'll hop down to the basement and do that right now 09-Feb-20 10:13 PM <__ice9#6039> My graphite furnace isn't ready yet 09-Feb-20 10:13 PM can you buy a round CBN insert to use instead of boron carbide? 09-Feb-20 10:13 PM inserts are brazed to solid support 09-Feb-20 10:13 PM the actual material is a tiny sliver 09-Feb-20 10:13 PM <__ice9#6039> That's very similar to diamond and should work if the inner surface is graphite coated 09-Feb-20 10:13 PM no they make solid CBN buttons afaik 09-Feb-20 10:14 PM issue is, how do you graphite coat the entire internal surface without coating the anode button 09-Feb-20 10:14 PM https://www.ebay.com/itm/2-pcs-RISHET-TOOLS-RNGN-32-RNMN-32-090300-3-8-Round-Solid-CBN-button-insert/233473107962 09-Feb-20 10:14 PM way too thick 09-Feb-20 10:14 PM grindable probably 09-Feb-20 10:14 PM <__ice9#6039> Ahahahahahaha 09-Feb-20 10:14 PM <__ice9#6039> Grind CBN 09-Feb-20 10:14 PM just an example, they probably come in many thicknesses 09-Feb-20 10:14 PM with diamond grit 09-Feb-20 10:14 PM and itself 09-Feb-20 10:15 PM <__ice9#6039> And immense patience 09-Feb-20 10:15 PM automatic jig and overnight 09-Feb-20 10:15 PM <__ice9#6039> Come back in morning, nothing left but powder 09-Feb-20 10:15 PM <__ice9#6039> I don't think so though 09-Feb-20 10:15 PM <__ice9#6039> That would probably work 09-Feb-20 10:16 PM lap two of the buttons together with some diamond grit haha 09-Feb-20 10:16 PM nice that they are usually sold in pairs 09-Feb-20 10:22 PM <__ice9#6039> Hahahahahaha 09-Feb-20 11:20 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-1D669.png 09-Feb-20 11:20 PM The back side of a BPG400 09-Feb-20 11:20 PM It looks like they're using epoxy for feedthroughs - on a UHV gauge! 09-Feb-20 11:20 PM How is that? 09-Feb-20 11:22 PM what makes you thing that that's epoxy? 09-Feb-20 11:23 PM Looks flowy 09-Feb-20 11:23 PM so does glass when it's hot 09-Feb-20 11:23 PM it is not hot 09-Feb-20 11:24 PM I hope the epoxy isn't actually flowy as well 09-Feb-20 11:24 PM That would be very bad indeed 09-Feb-20 11:24 PM Also, there's this stuff 09-Feb-20 11:24 PM https://www.accuglassproducts.com/polishing-and-cleaning-supplies/high-temperature-uhv-compatible-epoxy 09-Feb-20 11:24 PM 1x10^-10 torr 09-Feb-20 11:24 PM Too good to be true? 09-Feb-20 11:24 PM It's actually far cheaper stuff, ignore the price 09-Feb-20 11:24 PM It's actually this 09-Feb-20 11:24 PM https://www.epotek.com/site/technical-material-brochure/index.php?option=com_content&view=article&id=221%3Aepotek-353nd-family-of-products-for-fiber-optics 09-Feb-20 11:24 PM Which is... not rated... for vacuum, at all? 09-Feb-20 11:39 PM is it possibly glass with some epoxy backing (not sure why)? seems odd that they would use epoxy on something like that 09-Feb-20 11:41 PM <__ice9#6039> Again, isn't this just the figure for offgassing? Offgassing while the entire bulk mass is inside a UHV chamber is different from bulk permeability when one side is outside the chamber. 09-Feb-20 11:41 PM Honestly, I'm not sure 09-Feb-20 11:42 PM <__ice9#6039> Usually that figure for epoxy is applicable to using the epoxy to attach something inside the chamber, not using it as the chamber. 09-Feb-20 11:43 PM I wonder if it's possible to braze feedthroughs as they do viewports 09-Feb-20 11:43 PM Apparently quartz is brazed using PbSn 09-Feb-20 11:43 PM (also known as solder) 09-Feb-20 11:43 PM <__ice9#6039> With ultrasound yes 09-Feb-20 11:43 PM <__ice9#6039> Other methods also exist 09-Feb-20 11:43 PM so just... poke a bunch of holes in a piece of glass, and essentially reflow pins into it, with ultrasonic support? 09-Feb-20 11:44 PM <__ice9#6039> I just built an ultrasonic soldering iron actually, but I don't know whether it will work that well. It kind of looks like it worked on stainless though. 09-Feb-20 11:44 PM <__ice9#6039> Let's find out.... 09-Feb-20 11:44 PM ceramics, too! 09-Feb-20 11:44 PM glass to ceramic tubes would be very neat 09-Feb-20 11:45 PM <__ice9#6039> Brb soldering lol 09-Feb-20 11:45 PM try soldering a viewport lol 09-Feb-20 11:58 PM <__ice9#6039> Some test objects: boro glass, silicon carbide, tungsten carbide, quartz, yttria stabilized zirconia, porcelain, alumina, aluminum foil, ceriated tungsten, titanium, stainless 316, aluminum plate 09-Feb-20 11:58 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200210_015625-3DF1A.jpg 09-Feb-20 11:58 PM <__ice9#6039> Plate temp is set to 280. This process is usually conducted on a hotplate 09-Feb-20 11:58 PM <__ice9#6039> Still warming up 09-Feb-20 11:59 PM That's an interesting hot plate design 09-Feb-20 11:59 PM with lots of goop 09-Feb-20 11:59 PM oh, here's a compound we haven't thought of 10-Feb-20 12:03 AM <__ice9#6039> Moving to #show-and-tell 10-Feb-20 12:03 AM Li2CO3 10-Feb-20 12:03 AM I can't find any mention of monocrystals 10-Feb-20 12:03 AM but... all the atoms are down there on the molecular weight list 10-Feb-20 12:03 AM oh, found one mention from 1982 10-Feb-20 12:03 AM zone melt 10-Feb-20 12:03 AM lithium borate... but also soluble 10-Feb-20 12:10 AM Umm, are you guys still looking at potential materials for vacuum tight x-ray windows? Kinda want to get caught up to speed here but there's a lot of conversations with many tangents to read through 10-Feb-20 12:10 AM yes 10-Feb-20 12:10 AM and he's trying to do ultrasonic soldering right now 10-Feb-20 12:11 AM vacuum tight xray windows that are thermally conductive (and electrically?) 10-Feb-20 12:11 AM yes 10-Feb-20 12:11 AM ideally 10-Feb-20 12:11 AM Thermally conductive, electrically conductive(at least somewhat), non-toxic, affordable, and at least somewhat easy to solder/braze/attach to metal 10-Feb-20 12:15 AM Why is thermal conductivity important? Is this for detectors or something else? 10-Feb-20 12:16 AM there's going to be an ebeam dumping 10W of power into a 10 micron tungsten dot deposited directly on the vacuum side of the window 10-Feb-20 12:16 AM Oh, for a microfocus x-ray tube. Making your own or replacing existing windows? 10-Feb-20 12:16 AM making 10-Feb-20 12:16 AM transmission target, based on this paper 10-Feb-20 12:16 AM https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0156224&type=printable 10-Feb-20 12:16 AM apparently lithium triborate is a compound that is often used as a nonlinear crystal in lasers 10-Feb-20 12:16 AM and it's affordabliiiiish 10-Feb-20 12:16 AM Oh. Interesting. 10-Feb-20 12:16 AM https://www.nature.com/articles/s41467-019-08767-0 10-Feb-20 12:16 AM Graphite fluoride mixed in with Li 10-Feb-20 12:16 AM So this would make a surface that would be stable in air, while still impeding the generation of x-rays 10-Feb-20 12:16 AM (we don't really care about absorption at these thicknesses) 10-Feb-20 12:16 AM However, there is still an issue of it being lithium. 10-Feb-20 02:01 AM <__ice9#6039> That's fairly interesting 10-Feb-20 02:01 AM <__ice9#6039> Maybe try mixing with lithium fluoride 10-Feb-20 02:01 AM <__ice9#6039> Yeah LBO crystals are super common 10-Feb-20 02:01 AM <__ice9#6039> Hmm that Nature paper says air stable but handled in a dry-room 10-Feb-20 02:01 AM <__ice9#6039> Granted LiF is also hygroscopic 10-Feb-20 02:29 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-F6689.png 10-Feb-20 02:29 AM I will be joining the Edwards owners club, after all. 10-Feb-20 02:29 AM Threw in a compatible controller for basically pennies 10-Feb-20 02:34 AM <__ice9#6039> Nice 10-Feb-20 03:32 AM 24V is such a nice voltage. My EXT70 runs at 80v for some stupid reason 10-Feb-20 04:18 AM I think I found where the electron beams hit my chamber 10-Feb-20 04:18 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-E4334.png 10-Feb-20 04:18 AM 50 mA @ 30 kV might just be a bit much 10-Feb-20 07:06 AM Oop 10-Feb-20 09:19 AM Stupid question: if I put a circuitboard uncoated in my SEM and image in low vac mode, am I going to destroy it? 10-Feb-20 09:45 AM probably 10-Feb-20 09:54 AM @Spirit you'll need to edit your HTML better to prevent us from finding your auction purchases https://www.ebay.com/itm/Edwards-EXT255H-24V-turbomolecular-pump/254474609192?nordt=true&orig_cvip=true&rt=nc&_trksid=p2546137.m43663.l10137&pageci=84feed55-f80d-40ae-8392-297fbfb98ba0 10-Feb-20 10:35 AM lol 10-Feb-20 10:35 AM I saw the edits more as "this should at least communicate that I dont want to publicly link the auction to everyone " ;) 10-Feb-20 10:40 AM Heh, I saw it as a challenge 10-Feb-20 10:40 AM Heh yeah, I wasn't expecting to hide it since I was showing an ebay purchase, but I'm sending the image elsewhere so I'm just not screaming what I bought and how much I paid 10-Feb-20 11:20 AM You paid ~ the same as buying a power cable and cooling fan directly from leybold 10-Feb-20 11:23 AM I also bought what he's claiming is a dead pump 10-Feb-20 11:41 AM But I don't see any orings in the edwards diagrams, so either the guy is less competent than he claims, or he just ripped me off with a thoroughly destroyed pump 10-Feb-20 12:02 PM The listing doesn't mention orings, did the seller in a chat with you? 10-Feb-20 12:03 PM No, I'm just wondering what he means by "It was not possible to reach an adequate vaccum with the pump before it was removed from the equipment." 10-Feb-20 12:06 PM i just checked out the manual for the ext255h and i am seeing some orings on the cross section view but they are not labeled? 10-Feb-20 12:06 PM but still not sure those would really cause that 10-Feb-20 12:06 PM maybe if you really brute forced something during assembly 10-Feb-20 12:08 PM Where do you see the orings? 10-Feb-20 12:10 PM pdf page 10 (marked as pg4) https://www.idealvac.com/files/manualsII/Edwards_EXT255H_Manual.pdf 10-Feb-20 12:10 PM the solid black bits i believe are the orings 10-Feb-20 12:10 PM so you have one between the top housing and the motor section, one on the exhaust, and a couple in the oil/bearing area 10-Feb-20 12:11 PM Ah yeah I see one between the top housing and bottom 10-Feb-20 12:11 PM I think the bearing orings are to prevent oil leaking out 10-Feb-20 12:12 PM not sure about that 10-Feb-20 12:13 PM Those would be hard to find replacements for 10-Feb-20 12:13 PM i think both the orings in the oil/bearing area of the diagram are sealing to keep the oil/bearing area in vacuum too 10-Feb-20 12:13 PM not to keep the oil in 10-Feb-20 12:14 PM Yeah, might be 10-Feb-20 12:14 PM But foreline vacuum 10-Feb-20 12:14 PM Rubber works with that even 10-Feb-20 12:14 PM could be that someone hamfisted an oil reservoir swap 10-Feb-20 12:14 PM I hope the guy is just incompetent 10-Feb-20 12:15 PM that would be the best case haha where there is nothing actually wrong 10-Feb-20 12:30 PM I've discovered another interesting thing 10-Feb-20 12:30 PM "Dispenser cathodes" 10-Feb-20 12:30 PM The Dispenser Cathode. A new Type of Thermionic Cathode for Gaseous Discharge Tubes 1939 10-Feb-20 01:23 PM Nevermind, all the new hot stuff is carbon nanotubes 10-Feb-20 01:23 PM https://www.sciencedirect.com/science/article/abs/pii/S0008622315300683 10-Feb-20 01:23 PM The paper describes in detail that you don't need any fancy equipment(besides a furnace) to make CNT field emitters! 10-Feb-20 01:23 PM That completely solves the issue of filaments for low power x-ray heads, since the performance can be way worse than theirs 10-Feb-20 02:35 PM After further consideration and research, I don't think it's feasible to make an all-in-one anode-substrate-heatsink-window combo that isn't also beryllium @__ice9 10-Feb-20 02:35 PM I think I'll make a thin graphite anode substrate internally, and a CVD diamond wafer vacuum window 10-Feb-20 02:35 PM The only question is how to braze diamond to aluminium or kovar 10-Feb-20 02:35 PM I've sent an inquiry asking how much a 5x0.5mm round window would cost 10-Feb-20 03:05 PM @piGuy I don’t think you’d destroy the SEM or the pcb, if you have low vac mode. It’ll offgas and if it’s not coated it will have bad beam drift, but you should still be able to image it. You have to find the proper accel. voltage for the insulating material though Use a low kV and increase until it gets darker as you image it. This is positive charging. Now keep increasing it until it no longer turns darker with each scan, but brighter. This is negative charging. You want the voltage where it switches from pos. to neg. charging, this is the highest accel voltage you can use for an insulating material 10-Feb-20 03:05 PM It's not the charging that is the issue 10-Feb-20 03:05 PM Remember that it's an electron flow 10-Feb-20 03:06 PM wdym? 10-Feb-20 03:06 PM If you’re imaging an insulating and you have to take charging into account. Esp if you can’t sputter coat it 10-Feb-20 03:07 PM He's asking if he'll kill the parts on the board 10-Feb-20 03:07 PM which he will, probably 10-Feb-20 03:08 PM ohh I was thinking more killing the sem than the board 10-Feb-20 03:08 PM Oh yeah no the sem won't die no matter what 10-Feb-20 03:09 PM I don’t really see an advantage to using an sem to image a pcb? are there parts that are small enough a decent optical scope can’t see (not versed with pcb stuff) 10-Feb-20 03:10 PM not really, but I guess studying the quality of the tracks or vias would be useful 10-Feb-20 03:26 PM Neighbouring lab accidentally just undid their forevac kf connection 10-Feb-20 03:26 PM OOP 10-Feb-20 03:26 PM Sad turbos 10-Feb-20 03:30 PM how do you even "accidentally" undo something like that? 10-Feb-20 03:30 PM talk about a really bad Monday 10-Feb-20 03:33 PM ... scrap pile? @idmb :P 10-Feb-20 03:39 PM They missed the memo that their pumping configuration had changed, and disconnected the temporary scroll pump from the tee that also has a valve to their big pump 10-Feb-20 03:39 PM Without closing the valve between the scroll and the tee, when the scroll was on 10-Feb-20 03:41 PM So what's the salad count? 10-Feb-20 03:41 PM Unsure. What happens when you open the forevac to atm? 10-Feb-20 03:41 PM What do you think happens when an MKS 500 gauge is on and instantly opened to atmosphere? Anything bad? 10-Feb-20 03:43 PM https://youtu.be/wdLY5pzocyk?t=67 10-Feb-20 03:43 PM This is what happens 10-Feb-20 03:43 PM the 500 gauge will survive, it's cold cathode 10-Feb-20 03:43 PM Well, it obviously depends on whether it was running or not 10-Feb-20 03:43 PM If the turbo isn't running, a reverse vent will spin it up the wrong way to a few hundred or maybe thousand rpm, but it shouldn't die 10-Feb-20 03:43 PM But if the turbo was running... well, it's gone 10-Feb-20 03:48 PM Apparently they’ve turned the turbos back on 10-Feb-20 03:48 PM The 500 was on 10-Feb-20 03:48 PM That means they survived the vent 10-Feb-20 03:52 PM But how 10-Feb-20 03:52 PM My guess is they weren't running 10-Feb-20 03:52 PM Which weren’t? 10-Feb-20 03:52 PM Turbos 10-Feb-20 03:52 PM The turbos were absolutely running 10-Feb-20 03:52 PM Or, OR, someone spent way too much time undoing the obviously under atmospheric pressure hoses 10-Feb-20 03:52 PM 100% 10-Feb-20 03:52 PM And it vented slowly? 10-Feb-20 03:53 PM The turbos sniffed a minor vent(gas load), went into estop, and spun down to <50% before someone blew the handle completely 10-Feb-20 03:53 PM OH 10-Feb-20 03:53 PM It was slow apparently 10-Feb-20 03:54 PM Going from standby to vent-safe speeds is a plausible explanation 10-Feb-20 03:58 PM All I can say is yikes 10-Feb-20 03:58 PM In fairness their turbos are all like 6 years old 10-Feb-20 03:58 PM No new babies 10-Feb-20 03:58 PM 6 years old, not new 10-Feb-20 03:58 PM psht 10-Feb-20 03:58 PM That’s 10-Feb-20 03:58 PM Several grant cycles 10-Feb-20 03:58 PM heh, academia 10-Feb-20 03:58 PM I wish I could skip the whole degree thing and just run a project in a well-funded lab 10-Feb-20 04:02 PM Don't we all 10-Feb-20 04:07 PM There's the answer: we all start a time-share private lab 10-Feb-20 04:07 PM I dunno, the guy who gave me the bottle of SF6 working in a well kitted lab in NYC with a bunch of people doing MEMs and microfluidics and such and most of them don't have degrees apparently. 10-Feb-20 04:07 PM private lab too probably 10-Feb-20 04:07 PM I dunno how you get funding for the equipment they have especially in the city privately funded 10-Feb-20 04:07 PM But possibly 10-Feb-20 04:07 PM he offered to run wafers for me, if for example I get sputtering and etching working but have no way of doing masks he can make me either chromium masks or just send him wafers and he will do the photoresist development for me... 10-Feb-20 04:07 PM they have a laser based sub-micron maskless litho setup <3 10-Feb-20 04:09 PM So they are completely not affiliated with any academic institutions, government agencies or huge companies? 10-Feb-20 04:10 PM I don't know, I didn't ask, but wait I am confused here, what do you mean by private funding now? either way, if they got funding without degrees its still cool 10-Feb-20 04:10 PM but yea he said most of the guys in that lab its like if they have a degree they are more like "what happened" then "oh good" lol 10-Feb-20 04:10 PM because a lot of people who go to college train on such specific equipment... 10-Feb-20 04:10 PM I've heard many stories of people getting hired into fabs out of college and either getting frustrated with the old equipment or refusing to use it lol 10-Feb-20 04:10 PM like uhhmmmm welcome to the real world 10-Feb-20 04:13 PM Very true, but even in college you sometimes have to deal with extremely old stuff that no one wants anymore. The main advantage I see of academia for me is not being under the pressure of developing something commercial (that makes money) and having a degree of freedom in doing what you want 10-Feb-20 04:14 PM publish or perish 10-Feb-20 04:15 PM Publishing can be a lot more flexible than making a commercially successful thing. Something didn't work? You can still publish it, but you can't bring that to market 10-Feb-20 04:18 PM ehhh... so I mean thats a mindset thing, for me for example I love working on a project with a good team and having a product to get out 10-Feb-20 04:18 PM it gives you a goal, a build up 10-Feb-20 04:18 PM On the other hand, you only need a successful venture or two to fund dozens of mistakes 10-Feb-20 04:18 PM open-endedness or too much freedom and my ADHD just... OH SHINY 10-Feb-20 04:18 PM but I get what you mean, having freedom is nice 10-Feb-20 04:19 PM It's freedom with asterisks 10-Feb-20 04:19 PM Lol, yeah that's a major problem for me too. It's not like you don't get any restrictions or always work alone in academia, it depends on the lab and where you are in your career 10-Feb-20 04:19 PM There's always the pressure to get your degree done, get tenured... etc. 10-Feb-20 04:20 PM the biggest thing that turns me off from academia is the studying to pass a test 10-Feb-20 04:20 PM there are no tests in real life 10-Feb-20 04:20 PM now some courses are worse and or better for this 10-Feb-20 04:21 PM A commercially successful venture that would fund literally anything you want 10-Feb-20 04:21 PM some have open ended final projects which are great 10-Feb-20 04:21 PM but some its just a test... 10-Feb-20 04:21 PM Exactly what I'm doing right now... Studying for a test... This is getting depressing now 10-Feb-20 04:21 PM Most courses just end with a test... Even the freaking lab classes 10-Feb-20 04:22 PM <__ice9#6039> @Spirit as long as you can metalize the rim of the diamond window somehow, joining it to kovar will likely not be very difficult. 10-Feb-20 04:22 PM Except CTE 10-Feb-20 04:22 PM The kovar will either pull the window apart(unlikely) or just rip the joint off 10-Feb-20 04:23 PM <__ice9#6039> The CNT field emission paper is very impressive 10-Feb-20 04:23 PM More importantly replicable 10-Feb-20 04:23 PM Unlike most 10-Feb-20 04:24 PM @Mason_Yu exactly, its just so stupid... no real world thing works that way, like I get it for certain fields... medical I want you to know what drugs do what... study that test it 10-Feb-20 04:24 PM driving, yea lets have a test on that and make sure people REALLY know what signs and signals mean 10-Feb-20 04:24 PM but like... 10-Feb-20 04:24 PM in fields where its about being open-minded and thinking outside of the box 10-Feb-20 04:24 PM putting someone in a box does not help this 10-Feb-20 04:24 PM obviously there will be tests of fundamentals, but it just gets ridiculous at some point 10-Feb-20 04:25 PM And to a certain degree physics is like this too. Like 95% of the physics GRE is just literally regurgitating back tests, including the questions they deemed "practical problems" 10-Feb-20 04:25 PM for people like us who spend our free time and money doing what we are PAYING to learn, it just makes no sense 10-Feb-20 04:26 PM I literally had to pay my school to take an extra credit just so I could get my own little spot in a lab to build the DPF 10-Feb-20 04:26 PM With my own money mind you 10-Feb-20 04:27 PM <__ice9#6039> Oh I didn't say keeping it joined would be easy. 10-Feb-20 04:27 PM the money you spent on college you could have gotten a house with a shop in the back yard 10-Feb-20 04:28 PM <__ice9#6039> Huh. Try quartz or invar. 10-Feb-20 04:28 PM Oh actually yeah, invar! 10-Feb-20 04:28 PM But... well, that's... a bit of a contradiction 10-Feb-20 04:28 PM Kovar to invar joint? 10-Feb-20 04:29 PM <__ice9#6039> Make the entire tube out of brazed-together quartz lol 10-Feb-20 04:29 PM jesus you're sadistic 10-Feb-20 04:29 PM <__ice9#6039> Hahahahahaha 10-Feb-20 04:33 PM Physics GRE is comical 10-Feb-20 04:33 PM Best way to study is just get really fast with the previous / practice ones 10-Feb-20 04:33 PM It’s too urgent to need fundamentals 10-Feb-20 04:58 PM Ok apparently they didn’t undo a connection. Someone slowly opened a valve to atmosphere 10-Feb-20 04:58 PM So I guess the turbos were slowly slowed 10-Feb-20 04:58 PM yep 10-Feb-20 05:00 PM Is it advisable to just weld everything 10-Feb-20 05:00 PM I will wrap everything in duct tape after baking 10-Feb-20 05:00 PM Thou shalt not pass 10-Feb-20 05:01 PM <__ice9#6039> @Spirit grow the diamond film onto a circular molybdenum sheet by CVD, braze the molybdenum to the end of the tube, anneal, dissolve the molybdenum with acid in the center, leaving bare diamond. 10-Feb-20 05:02 PM New safety feature: plastic mounting frame + 10kV electrode on chambers and isolated power supplies for pumps. 10-Feb-20 05:02 PM Oh, going one step up in the process 10-Feb-20 05:02 PM <__ice9#6039> Bleach works too 10-Feb-20 05:02 PM Touch something? Get a hocked 10-Feb-20 05:02 PM That's an interesting idea 10-Feb-20 05:02 PM But CVD at home seems... yucky 10-Feb-20 05:03 PM <__ice9#6039> Seems useful, you mean ^^ 10-Feb-20 05:03 PM useful, sure, but really complicated 10-Feb-20 05:50 PM <__ice9#6039> Physically, yes. Electronically, no. 10-Feb-20 05:59 PM Hey, if it all it took was a power supply I'd be running a CVD farm yesterday 10-Feb-20 06:10 PM <__ice9#6039> Just have to tune it, you know? Empirically ^^ 10-Feb-20 06:10 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Schematic-of-microwave-plasma-enhanced-CVD-E8214.png 10-Feb-20 06:10 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Schematic-of-a-typical-microwave-plasma-as-7077C.jpg 10-Feb-20 06:10 PM <__ice9#6039> In all seriousness, it's mostly a matter of guiding microwaves properly and sticking a furnace controller onto a C-type thermocouple buried in the staging plate. You can skip that if you use a torch or arc-jet and instead control a water cooling system's flow rate, but the microwave+heater approach is likely easier. 10-Feb-20 06:14 PM Come on, you know the ultrasonic iron is far easier than this 10-Feb-20 06:14 PM Process control versus shaving a bit of alu off 10-Feb-20 06:14 PM <__ice9#6039> Hahaha 10-Feb-20 06:14 PM <__ice9#6039> Realistically, the main problem with these is that they tend to just produce soot or graphite except within a rather narrow region of parameter space. 10-Feb-20 06:16 PM Perhaps it's possible to selectively activate(chemically) the diamond with a photoresist mask, then electrically grow the brazing ring on? 10-Feb-20 06:16 PM <__ice9#6039> Torches and arc jets are usually easier to get diamond from than microwave reactors, with faster growth, but also lower resulting quality 10-Feb-20 06:16 PM <__ice9#6039> I'm not sure. I don't know enough about diamond lithography 10-Feb-20 06:17 PM Wonder if it's possible to grow CVD on tungsten directly 10-Feb-20 06:17 PM so then you just etch away a doughnut shaped hole for the window, leaving the brazable ring and the target dot 10-Feb-20 06:17 PM and then coating the missing space with ITO to keep it non-xraying but conductive to dissipate the charges 10-Feb-20 06:23 PM <__ice9#6039> It can be done on molybdenum. Not good enough? 10-Feb-20 06:23 PM <__ice9#6039> Not sure about tungsten. 10-Feb-20 06:23 PM Oh yeah molybdenum will work too 10-Feb-20 06:23 PM Mo targets are common 10-Feb-20 06:23 PM <__ice9#6039> That's the most common substrate for CVD diamond. 10-Feb-20 06:23 PM <__ice9#6039> Anyway yeah that's exactly what I suggested re: bleach 10-Feb-20 06:23 PM <__ice9#6039> Didn't think of the ITO step though. That's reasonable. 10-Feb-20 06:23 PM <__ice9#6039> Silicon substrates work too 10-Feb-20 06:23 PM <__ice9#6039> Fwiw an arcjet is literally just a plasma cutter pilot arc. 10-Feb-20 06:23 PM <__ice9#6039> Not much tuning needed. Just flip the trigger switch and make sure the spacing to the stage is right. 10-Feb-20 06:23 PM <__ice9#6039> The even more ridiculously simple method is pointing an oxyacetylene torch running a reducing flame at a water cooled piece of molybdenum. 10-Feb-20 06:23 PM <__ice9#6039> The temperature still needs to be controlled though. And atmosphere is harder to control that way so there will be more impurities 10-Feb-20 06:23 PM <__ice9#6039> Arc jet is better 10-Feb-20 06:23 PM <__ice9#6039> Schematic doodle 10-Feb-20 06:23 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/3-s2.0-B9780128013007000085-f08-07-9780128-3C88C.jpg 10-Feb-20 06:23 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/88213-d57fb948a5b822ab879b47d2b7bf7f0d-AFE80.jpg 10-Feb-20 06:23 PM <__ice9#6039> Nothing to it, already have one at home 10-Feb-20 06:23 PM <__ice9#6039> So then it's (a) build a chamber to keep oxygen out, (b) build a plasma torch into a pass-through, (c) build a water-cooled stage mountable in the chamber, (d) obtain a gas mixer, (e) figure out closed loop control over the water cooling, probably by just rigging a furnace controller to select between two different pumping speeds for the water cooling loop. 10-Feb-20 06:23 PM <__ice9#6039> Main failure mode would probably be something related to difficulty with stage temperature, e.g. maybe the arc jet doesn't end up heating it enough to overcome radiative losses. So then perhaps a heater coil instead of a coolant loop might be needed, resulting in having to build another stage design. Etc. 10-Feb-20 06:36 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/uTU5k-8DF12.png 10-Feb-20 06:36 PM Essentially, here's the idea 10-Feb-20 06:36 PM A seriously multistep process 10-Feb-20 06:36 PM <__ice9#6039> Yeah that's what I thought 10-Feb-20 06:36 PM But... doable? 10-Feb-20 06:37 PM <__ice9#6039> Depends entirely on whether you can grow the diamond onto Mo or braze it there 10-Feb-20 06:37 PM <__ice9#6039> The rest looks probably feasible with thin film deposition 10-Feb-20 06:37 PM The vacuum seal would have to rely on the Mo->Diamond->Ceramic transition 10-Feb-20 06:38 PM <__ice9#6039> Yep 10-Feb-20 06:38 PM <__ice9#6039> You can braze molybdenum to ceramics I think. I know tungsten can go to uranium glass if nothing else. 10-Feb-20 06:38 PM Tungsten doesn't braze to uranium glass, it seals to the WO3 10-Feb-20 06:38 PM <__ice9#6039> Yeah molybdenum works fine 10-Feb-20 06:39 PM Partial solvation 10-Feb-20 06:39 PM <__ice9#6039> I know that. 10-Feb-20 06:39 PM <__ice9#6039> I didn't elaborate further. 10-Feb-20 06:39 PM <__ice9#6039> Mo doesn't need brazing either apparently 10-Feb-20 06:39 PM <__ice9#6039> Direct glass to metal oxide film interface 10-Feb-20 06:39 PM <__ice9#6039> Similarly 10-Feb-20 06:39 PM <__ice9#6039> https://www.researchgate.net/publication/231980738_On_the_optimization_of_a_dc_arcjet_diamond_chemical_vapor_deposition_reactor Spraying the methane at the target while using only H2 and Ar in the torch works best 10-Feb-20 06:43 PM I actually forgot a step 10-Feb-20 06:43 PM Minor correction 10-Feb-20 06:43 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Av5um-15174.png 10-Feb-20 06:43 PM Now this presents another problem 10-Feb-20 06:43 PM Making a notch in the ceramic 10-Feb-20 06:43 PM Macor... is machinable in this way, but how hard would it be to polish it that inner surface to 5 microns 10-Feb-20 06:43 PM (macor is ok for vacuum) 10-Feb-20 06:44 PM are ceramic fasteners worth looking into for vacuum? for assembling parts without having conduction 10-Feb-20 06:44 PM Inside, yes 10-Feb-20 06:44 PM Air barrier, no 10-Feb-20 06:44 PM Yeh inside 10-Feb-20 06:44 PM But it's within my reach and IMO simpler to just spot weld stuff 10-Feb-20 06:44 PM Or alumina/zirconia bakeable adhesive paste 10-Feb-20 06:46 PM was thinking for using them in sputter gun 10-Feb-20 06:46 PM you can yeah, but you shouldn't need to 10-Feb-20 09:09 PM <__ice9#6039> @Spirit what kind of bakeable adhesive paste? 10-Feb-20 09:09 PM the generic vacuum stuff 10-Feb-20 09:09 PM <__ice9#6039> Do you just mean furnace cement, or is this something new I haven't heard of? 10-Feb-20 09:09 PM high vacuum stuff 10-Feb-20 09:09 PM <__ice9#6039> Brand names? 10-Feb-20 09:09 PM zirconia and alumina in a safe and easily evaporable solvent 10-Feb-20 09:09 PM <__ice9#6039> Oh so literally just powder? 10-Feb-20 09:09 PM aremco ultratemp for example 10-Feb-20 09:09 PM <__ice9#6039> Once it bakes out I mean 10-Feb-20 09:09 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/516-04A-480x360-3E72F.png 10-Feb-20 09:10 PM <__ice9#6039> Like there isn't a binder? 10-Feb-20 09:10 PM it solidifies into a porous ceramic 10-Feb-20 09:10 PM <__ice9#6039> Ok so vacuum-grade ceramic cement. This looks useful for the ebeam. 10-Feb-20 09:10 PM it's meant to be permanent 10-Feb-20 09:10 PM I think you could get away with something like optical pitch for ebeam workholding 10-Feb-20 09:10 PM or a very cheese grater shaped vise 10-Feb-20 09:12 PM <__ice9#6039> Wow nice graphite cements too. This would be super useful for the graphite furnace 10-Feb-20 09:12 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/A02_15-36A97.pdf 10-Feb-20 09:12 PM <__ice9#6039> I bet this stuff costs a fortune but I can probably clone it from the SDS if they disclose enough 10-Feb-20 09:12 PM So THIS is the evil stuff that they bond light fixtures with. 10-Feb-20 09:12 PM <__ice9#6039> Apparently! 10-Feb-20 09:13 PM ceramabond 571 bonds to glass 10-Feb-20 09:13 PM huh 10-Feb-20 09:13 PM every time I see something that bonds to glass I now think "is this good for vacuum or not" 10-Feb-20 09:14 PM <__ice9#6039> Phenolic and graphite with carbon fiber in ethanol binder, not yet sure where the stickiness comes from though. https://www.aremco.com/news-item/1486-2/ 10-Feb-20 09:15 PM phenolic for sure 10-Feb-20 09:15 PM stickiness is probably just viscosity 10-Feb-20 09:15 PM graphite with phenolic would make wetty goo 10-Feb-20 09:15 PM <__ice9#6039> $150 with shipping on Amazon 10-Feb-20 09:15 PM <__ice9#6039> I have all this stuff already though 10-Feb-20 09:16 PM Amazon often has peculiar things 10-Feb-20 09:16 PM I wish they shipped here 10-Feb-20 09:17 PM <__ice9#6039> It's 40-60% graphite, 40-60% phenolic resin, and under 2% fumed silica 10-Feb-20 09:17 PM <__ice9#6039> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_20200210-231744-A499C.png 10-Feb-20 09:17 PM <__ice9#6039> Recipe--approximately 10-Feb-20 09:18 PM MSDSes are handy 10-Feb-20 09:18 PM <__ice9#6039> Solvent is a mix of methanol and ethanol 10-Feb-20 09:18 PM <__ice9#6039> It's impossible to mix phenol and formaldehyde without making bakelite or similar, so this is probably ground-up bakelite since it is a 1-component system. 10-Feb-20 09:19 PM Seems to me like it's an old formula 10-Feb-20 09:53 PM "Operating Environment These adhesives offer excellent chemical, electrical and ultra high thermal resistance, and do not outgas under high vacuum. The main limitations are (a) relatively low mechanical strength and (b) slight porosity after curing. Contact Aremco for suggestions about how to reduce porosity and produce gas-tight seals." 10-Feb-20 09:57 PM Suggestion: buy other seal 10-Feb-20 10:01 PM At least they don't outgas 10-Feb-20 10:43 PM <__ice9#6039> Porosity is expected from evaporation of the solvent binder while the cement sets 11-Feb-20 01:59 PM so @__ice9 just a MWCNT in EtOH paste 11-Feb-20 01:59 PM finely sanded/glass bead blasted rough copper cathode 11-Feb-20 01:59 PM and just... paint it on, bake/let dry? 11-Feb-20 02:00 PM <__ice9#6039> That would be fine yeah 11-Feb-20 02:01 PM that's like $1 per cathode 11-Feb-20 02:01 PM <__ice9#6039> You can use binders to improve the sticking quality 11-Feb-20 02:01 PM accounting for waste and machining 11-Feb-20 02:01 PM I wonder if VANTAs would make super high current cathodes 11-Feb-20 02:02 PM <__ice9#6039> https://www.nature.com/articles/s41598-017-12443-y etc 11-Feb-20 02:02 PM <__ice9#6039> Yeah I think crumpled forests are probably better but it's an empirical question and that's just my suspicion 11-Feb-20 02:02 PM <__ice9#6039> But yeah, one trade off here is that it becomes difficult to control beam power at a given potential 11-Feb-20 02:02 PM <__ice9#6039> Because these are so good at cold cathode emission 11-Feb-20 02:05 PM Why? 11-Feb-20 02:05 PM <__ice9#6039> Normally filament temp is used to regulate mA while the inverter driving the main transformer is used to regulate kVp 11-Feb-20 02:05 PM No no absolutely not 11-Feb-20 02:05 PM Not in high end/scientific tubes 11-Feb-20 02:05 PM They use... a grid! 11-Feb-20 02:05 PM :P 11-Feb-20 02:05 PM It's just a triode 11-Feb-20 02:05 PM <__ice9#6039> Oh I'm talking about high powered medical tubes 11-Feb-20 02:05 PM <__ice9#6039> Yeah I would believe that 11-Feb-20 02:05 PM <__ice9#6039> Ok cool then there's no issue 11-Feb-20 02:05 PM In those it's generally not controlled at all 11-Feb-20 02:05 PM Max filament, max voltage 11-Feb-20 02:05 PM And they control "mAs" 11-Feb-20 02:05 PM milliamp-seconds 11-Feb-20 02:05 PM an utterly dumb but universally standard measurement method 11-Feb-20 02:06 PM <__ice9#6039> For panoramics, it actually is controlled. 11-Feb-20 02:06 PM <__ice9#6039> Because motor motion is a constraint. 11-Feb-20 02:06 PM panos also have quite advanced tubes since they need to emit stable and for a long while 11-Feb-20 02:06 PM medical -> pano -> scientific, excluding huge NDT 11-Feb-20 02:07 PM <__ice9#6039> Hmm yeah that sounds about right. CT is its own thing though. Water cooled 100kW rotating anode tubes that look like something that belongs in a power plant. 11-Feb-20 02:07 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image-2FFFB.png 11-Feb-20 02:07 PM This is how hamamatsu does it 11-Feb-20 02:08 PM <__ice9#6039> Those just blast while the whole gantry spins, trying to process as fast as possible 11-Feb-20 02:08 PM the piece of glass is the part I'm missing 11-Feb-20 02:08 PM D: 11-Feb-20 02:08 PM cathode, I'm not sure what C is, wehnelt, and 32 seems to be the grid 11-Feb-20 02:08 PM <__ice9#6039> Lol I like the little 'electron -->', 'x-ray -->' labels, very cute 11-Feb-20 02:09 PM interestingly enough the tube looks exactly like that IRL 11-Feb-20 02:09 PM <__ice9#6039> 32 might be an einzal lens 11-Feb-20 02:09 PM with the 10a/11/11a/14 cup and 12 anode 11-Feb-20 02:09 PM absolutely identical 11-Feb-20 02:09 PM and the little T is a cutout inside 11-Feb-20 02:09 PM <__ice9#6039> Wait that's 6a probably 11-Feb-20 02:09 PM I will take more pictures once I feel like getting oily and skin cancery 11-Feb-20 02:09 PM it's still sitting in towels on my floor 11-Feb-20 02:10 PM <__ice9#6039> 6a is more likely to be the lens, then 32 would be a screen 11-Feb-20 02:10 PM 6a is a seal 11-Feb-20 02:10 PM I think 11-Feb-20 02:10 PM https://data.epo.org/publication-server/rest/v1.0/publication-dates/20040714/patents/EP1437757NWA1/document.html 11-Feb-20 02:10 PM <__ice9#6039> Hmm then it's unclear. Need to get that tiny focal point somehow, though in principle it could probably be done with cathode concavity alone. 11-Feb-20 02:10 PM let's see :P 11-Feb-20 02:10 PM (57) An X-ray tube 1 comprises of a valve 10 joined to an envelope main body 4 at one end side thereof and having an inner cylinder portion 10a extending inwardly at the other end side thereof, a metal tube 11 having an extension portion 11a abutting against the inner cylinder portion 10a on the outer periphery of one end side thereof and projecting to the outside of the valve 10 through the inner cylinder portion 10a at the other end side thereof, and a target supporter 12 supporting a target T at the one end side thereof and inserted into the metal tube 11 at the other side thereof. The inner cylinder portion 10a of the valve 10 and the extension portion 11a of the metal tube 11 are fuse-bonded to each other, and the target supporter 12 is welded to the end portion of the metal tube 11 projecting from the valve 10. 11-Feb-20 02:12 PM <__ice9#6039> 6 is just the housing for the electron gun, so yeah I guess that's a seal there 11-Feb-20 02:12 PM <__ice9#6039> The electron generating unit 3 accommodated in the electron gun accommodating portion 6 will be described. As shown in Fig. 1 and Fig. 3, the electron generating unit 3 contains a cathode C, a heater 30, a first grid electrode 31 and a second grid electrode 32. The cathode C, the heater 30, the first grid electrode 31 and the second grid electrode 32 are secured to a stem board 34 through plural (eight in this embodiment) pins 33a to 33h extending in parallel. Specifically, the cathode C is secured to the pin 33a (see Fig. 2) fixed to the stem board 34, and supplied with electric power from the outside through the pin 33a. Likewise, the heater 30 is secured to the pins 33b and 33c (see Fig. 2) fixed to the stem board 34, and supplied with electric power from the outside through the pins 33b and 33c. 11-Feb-20 02:12 PM <__ice9#6039> So yeah 32 is a grid and so is 31 11-Feb-20 02:20 PM <__ice9#6039> Hmm so you are planning to build a grid into your tube idea as well? 11-Feb-20 02:20 PM <__ice9#6039> Seems to add to alignment and feed-through complexity, but maybe less than I would expect, not sure 11-Feb-20 02:23 PM alignment complexity? 11-Feb-20 02:23 PM just an insulator and a mesh 11-Feb-20 02:23 PM like in nixies, except finer 11-Feb-20 02:23 PM feedthrough stays essentially the same, you have four pins 11-Feb-20 02:23 PM except instead of filament you get grid 11-Feb-20 02:23 PM cathode, grid, focus and something else 11-Feb-20 02:23 PM even three, not four 11-Feb-20 02:23 PM I could also make a pinch lens, but that adds focusing woes 11-Feb-20 02:23 PM so I think just a grid 11-Feb-20 02:26 PM <__ice9#6039> Ah yes that's true if you dispense with the filament entirely 11-Feb-20 02:26 PM <__ice9#6039> Yes 11-Feb-20 03:32 PM @Applied_Ion that sounds like something regular MWCNTs could do 11-Feb-20 03:33 PM What does the MW stand for in that lol 11-Feb-20 03:34 PM Multi wall 11-Feb-20 03:35 PM How does that differ from vertically grown? 11-Feb-20 03:35 PM Haven't heard of it before 11-Feb-20 03:36 PM they come in a powder 11-Feb-20 03:36 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/NH2-CNT_m02-C1AF3.png 11-Feb-20 03:36 PM whereas vertically aligned nanotubes are grown on your target substrate directly, and are aligned in a tight packing 11-Feb-20 03:36 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/www_machinedesign_com_sites_machinedesign-565A2.png 11-Feb-20 03:36 PM both have a HUGE surface area and very good field emission, but most of the field emission research I've seen is based around random single/multi wall CNTs 11-Feb-20 03:36 PM because they're far easier to work with, you can just put them in a solvent and paint them on something 11-Feb-20 03:36 PM VANTs have to be grown directly where you plan to use them, non-transferrable 11-Feb-20 03:40 PM Not transferrable, That we know of 11-Feb-20 03:40 PM Interesting to know. Actually, that would be great for low power Hall too. Though if MW actually has field emission and it's easy, I'd say it's worth investigating. Weird why it hasn't been looked at for propulsion applications before if that is the case 11-Feb-20 03:40 PM https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0156224&type=printable 11-Feb-20 03:40 PM See this paper 11-Feb-20 03:40 PM From what I can tell and ice9 confirms, bismuth can be omitted here 11-Feb-20 03:40 PM So essentially, they just screen-printed them. 11-Feb-20 03:40 PM pure CNTs seem to follow CNTs + Bi pretty much exactly, if not better 11-Feb-20 03:40 PM 30mA at 4.5kV 11-Feb-20 03:43 PM Thanks! I'll have to look into this more, this is a key hurdle for low power neutralizers cheap 11-Feb-20 03:44 PM I'll be trying to make x-ray tube cold cathodes out of them 11-Feb-20 03:45 PM DC or pulsed? If pulsed, see my suggestion in the radiation topic lol 11-Feb-20 03:46 PM DC 11-Feb-20 03:46 PM it's going to be a microfocus source 11-Feb-20 03:46 PM Ok lol yeah 11-Feb-20 03:46 PM But that is quite exciting that it is easier to do with emission capability 11-Feb-20 03:46 PM So literally just buy a bottle and paint it on? 11-Feb-20 03:46 PM yep 11-Feb-20 03:46 PM ~500-1000um diameter cathode, ~5-10um diameter target on a low atomic weight substrate 11-Feb-20 03:46 PM and I'm thinking of focusing the beam down to around 20-50um 11-Feb-20 03:47 PM Does it have to be a small cathode, or can it be bulk area? Like 1cm^2 flat surface? 11-Feb-20 03:48 PM I'm just concerned about focusing it 11-Feb-20 03:48 PM I'm just concerned about electrons lol 11-Feb-20 03:48 PM smaller beam size to start with, easier to work with 11-Feb-20 03:49 PM I just need emission 11-Feb-20 03:49 PM or are you talking about yours? 11-Feb-20 03:49 PM you can make it as big as you want 11-Feb-20 03:49 PM Oh man, this is potentially very exciting lol 11-Feb-20 03:49 PM How much does the cnt solution cost? Is it fairly common to get? 11-Feb-20 03:50 PM not solution, powder 11-Feb-20 03:50 PM $0.20 to $1.50/g 11-Feb-20 03:51 PM That's awesome 11-Feb-20 03:51 PM Any reference papers on coating or applying to a surface? 11-Feb-20 03:51 PM see above 11-Feb-20 03:51 PM they used a mix of fun organic solvents with bismuth, but just ethanol should work 11-Feb-20 03:51 PM not sure about surface prep though 11-Feb-20 03:51 PM I'm guessing ultrasonic in something aggressive(acetone?) or plasma clean should do the job 11-Feb-20 03:53 PM Bismuth is not needed though right? 11-Feb-20 03:53 PM yeah it's not 11-Feb-20 03:53 PM Any metal surface? 11-Feb-20 03:53 PM don't think it's even limited to metal 11-Feb-20 03:53 PM This just keeps getting better lol 11-Feb-20 03:53 PM Thanks a ton for the info, this is quite potentially big going forward on some of this tech 11-Feb-20 03:56 PM That's what I'm thinking with x-ray tubes! 11-Feb-20 03:56 PM So far I don't see any disadvantages 11-Feb-20 04:12 PM possibly stupid question but is this essentially what https://en.wikipedia.org/wiki/Aquadag is but a bit more robust? 11-Feb-20 04:12 PM no, it's nothing like it 11-Feb-20 04:12 PM this is a conductive electrode material, we're talking about field emission cathodes 11-Feb-20 04:37 PM So apparently you can purchase grown arrays 11-Feb-20 04:37 PM https://www.cheaptubes.com/product/multi-walled-carbon-nanotube-arrays/ 11-Feb-20 04:37 PM Might actually call these guys up for a quote just to see 11-Feb-20 04:37 PM those prices though 11-Feb-20 04:37 PM "quote or add to cart" 11-Feb-20 04:37 PM Yeah, probably too high, but you never know 11-Feb-20 04:38 PM Found a Russian company offering large CNTs for $0.24/g 11-Feb-20 04:38 PM Sent them an email if I could buy 50 grams for a test 11-Feb-20 04:39 PM Nice 11-Feb-20 04:39 PM 50 grams of CNTs, almost an incomprehensibly huge amount if you think microscale 11-Feb-20 04:39 PM Lol yeah 11-Feb-20 04:41 PM <__ice9#6039> That's absurdly much for that price wow 11-Feb-20 04:41 PM <__ice9#6039> I think I paid about $6/gram 11-Feb-20 04:42 PM Even still, a gram of CNTs would make a hundred or two x-ray tubes 11-Feb-20 04:42 PM With 90% of that going into waste on tools/mixing vessels lol 11-Feb-20 04:48 PM <__ice9#6039> Yes. A little goes an extremely long way. 11-Feb-20 04:48 PM It's essentially a "free" BOM item 11-Feb-20 04:49 PM <__ice9#6039> Note these are also used heavily in e.g. ultracapacitors 11-Feb-20 04:49 PM Still have to solve how to make the target anode 11-Feb-20 04:51 PM <__ice9#6039> Yeah, diamond CVD looks difficult. I still think the most approachable method is probably just a DC arc-jet, but am not sure whether the ~1-2kW typical of plasma cutter pilot arcs would be enough to reach the necessary temperatures, so it isn't immediately clear whether the stage should have a water cooling plate or a heating element. I guess that just means it should have both. 11-Feb-20 04:51 PM Maybe there's a way to avoid CVD? 11-Feb-20 04:51 PM <__ice9#6039> For diamond? 11-Feb-20 04:51 PM <__ice9#6039> Well the logical alternative is to buy the diamond first and then metalize it I think 11-Feb-20 04:52 PM Or maybe avoiding diamond altogether 11-Feb-20 04:52 PM <__ice9#6039> Coefficient of thermal expansion matching will still be difficult 11-Feb-20 04:52 PM I wonder if there's any heavier materials that don't adhere to Kramer's law 11-Feb-20 04:52 PM <__ice9#6039> Well boron carbide is maybe an option 11-Feb-20 04:53 PM If only it existed in sheet form 11-Feb-20 04:53 PM (commercially) 11-Feb-20 04:53 PM <__ice9#6039> Yeah I don't quite have that graphite furnace ready just yet. Though the carbonization furnace worked in testing today. 11-Feb-20 04:53 PM <__ice9#6039> Interior got pretty contaminated so I had to burn it all out with an air cycle empty after that, but the interior is mainly silica and zirconia instead of alumina anyway and there doesn't end up being any apparent damage. 11-Feb-20 04:54 PM The criteria are quite strict but there's not many: 1 - Vacuum tight 2 - Sucks at generating x-rays, but lets them through 3 - Easy to manufacture and bond to 11-Feb-20 04:54 PM Optionally 4- electrically conductive 11-Feb-20 04:54 PM but that's pushing it 11-Feb-20 04:55 PM <__ice9#6039> Be fails hard at 3 11-Feb-20 04:55 PM Not... really 11-Feb-20 04:55 PM You can buy solid Be rod and machine it into thin enough(~100-300um) disks 11-Feb-20 04:55 PM But the whole "kills you now and later" thing is unpleasant 11-Feb-20 04:56 PM <__ice9#6039> Would rather try to grind down B4C with diamond dust than ever machine any beryllium 11-Feb-20 04:56 PM yup 11-Feb-20 04:56 PM Why isn't there some sort of lithium carbonate borate berylli-ate-um-in that fits these criteria :( 11-Feb-20 04:56 PM I wonder if lithium can somehow be air-stabilized 11-Feb-20 05:02 PM <__ice9#6039> Yes by making ceramics with it and other heavier elements -__- 11-Feb-20 05:03 PM besides that ;~; 11-Feb-20 05:03 PM the GF-Li-Thing is interesting but it's hard to work with in air, even if the end product would be stable from the working surface end 11-Feb-20 05:50 PM Ok so i found a gas permeability rate for silicone, but I'm not sure how to convert that to a pressure ... I guess it depends on the area of silicone i have, as well as the chamber volume? 11-Feb-20 05:50 PM The rate is just what the pressure gain per volume would be 11-Feb-20 05:51 PM For example, the max attainable pressure of the chamber is 8.5 torr, when i put the gauge directly on the pump, i get 1x10-2 torr 11-Feb-20 05:51 PM Is this silicone alone? 11-Feb-20 05:51 PM Or bigger physical leak elsewhere? 11-Feb-20 05:51 PM Feels like more than gas permeability, but that's just a hunch 11-Feb-20 05:51 PM Well, I did squirt alcohol at one joint and pressure rose, and there was no silicone there, so maybe more than a hunch 11-Feb-20 05:53 PM Much bigger physical leak somewhere 11-Feb-20 06:09 PM <__ice9#6039> If you have threaded connections anywhere, coat the threads with high vac grease instead of PTFE tape. Not sure if applicable here, but I have seen this a lot. 11-Feb-20 06:16 PM ptfe “works” if you have any pumping but yeah it’s not great 11-Feb-20 06:59 PM Hmm, i did self-tap a kf to threded fitting into the PVC... Figured it was molecularly close since it was self tapped and super hot by the end 11-Feb-20 06:59 PM The base the PVC pipe sits on is from some lab degas bell jar setup, and I'm also suspecting the tubing there might be loose, since there's a few barbed fittings 11-Feb-20 06:59 PM Gonna hose clamp those later 11-Feb-20 06:59 PM Will unscrew the kf threaded fitting a bit and add some grease 11-Feb-20 08:12 PM <__ice9#6039> Hose barbs can and should also be greased, as well as clamped 11-Feb-20 08:18 PM I’ve met people who disagree but in my experience they’re wrong 12-Feb-20 12:34 AM welp... grease and clamps didn't help 12-Feb-20 12:34 AM I think it's time to rethink this chamber construction... the base plate being from some vacuum degasser belljar setup is the most suspect at this point for an 8.3 torr level when the pump got to 1*10-2 12-Feb-20 12:35 AM aren't you using a pvc chamber? 12-Feb-20 12:35 AM since it's PVC... I'm thinking of getting a flat piece of PVC and solvent welding it 12-Feb-20 12:35 AM yeah 12-Feb-20 12:35 AM stick a gauge through a bit of PVC and see how crappy the PVC you have is 12-Feb-20 12:35 AM could be just bad pipe outgassing 12-Feb-20 12:35 AM welding the flat piece to the bottom of the pipe 12-Feb-20 12:35 AM I doubt 8 torr is outgassing 12-Feb-20 12:35 AM but I do have a MKS901p threaded into the side 12-Feb-20 12:36 AM threading plastic = bad vacuum 12-Feb-20 12:36 AM I greased it tonight 12-Feb-20 12:36 AM gooped it up real good 12-Feb-20 12:36 AM I've had nothing but bad experiences with anything but epoxy or welding with plastic and vacuum 12-Feb-20 12:36 AM like, even a bead of grease at the surface 12-Feb-20 12:36 AM I fear now that I greased it, epoxy might fail to hold 12-Feb-20 12:37 AM I also wouldn't epoxy a gauge in lol 12-Feb-20 12:37 AM well it's a threaded KF16 fitting 12-Feb-20 12:37 AM then supercleaning and epoxy should eliminate that issue 12-Feb-20 12:37 AM potential issue* 12-Feb-20 12:38 AM after unscrewing it, I found PVC powder and strings of PVC (never unthreaded it after self-tapping with the fitting, since it was super hot, I figured it might have expanded and then later shrunk to seal) 12-Feb-20 12:38 AM but cleaning the dust and strings didn't seem to fix anything 12-Feb-20 12:39 AM that smells like a crossthread 12-Feb-20 12:39 AM another idea is to drive an hour and buy 15 feet of stainless pipe, the same 10" diameter 12-Feb-20 12:39 AM heh that'd be much more optimal 12-Feb-20 12:40 AM I have a friend with a welder... but idk if he has a rotary stage or a potters wheel to spin it 12-Feb-20 12:40 AM and being 3ft high, spinning it while welding seems sketchky 12-Feb-20 12:40 AM you can walk around something like this 12-Feb-20 12:40 AM with a heavy pulse setting 12-Feb-20 12:40 AM external weld? 12-Feb-20 12:40 AM that would just mean I get some virtual leaks, right? which is high vac 12-Feb-20 12:41 AM full fusion, with the edge rolling over 12-Feb-20 12:41 AM "edge rolling over" doesn't parse 12-Feb-20 12:41 AM let me illustrate 12-Feb-20 12:41 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/dpOMm-0A670.png 12-Feb-20 12:41 AM prior to weld 12-Feb-20 12:43 AM hmm, but what if the end plate, which I want to weld to the pipe... is much larger than the pipe (i.e. several cm) 12-Feb-20 12:43 AM and not round 12-Feb-20 12:43 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/RyrAA-861CA.png 12-Feb-20 12:43 AM after the weld 12-Feb-20 12:43 AM you can still weld through if it's thin enough 12-Feb-20 12:43 AM basically, just no filler and have the inside smooth 12-Feb-20 12:43 AM it's going to be hard to do but it's possible 12-Feb-20 12:44 AM it's 3/16 inch thick 12-Feb-20 12:44 AM the end plate or pipe? 12-Feb-20 12:44 AM the pipe 12-Feb-20 12:44 AM and the end plate? 12-Feb-20 12:44 AM haven't thought that far yet, but presumably at least as thick 12-Feb-20 12:45 AM slightly thinner should be doable 12-Feb-20 12:45 AM thicker I don't know 12-Feb-20 12:45 AM I used some NASA calculation for a pipe-based vac chamber, and the recommendation was just under 3/16" thick 12-Feb-20 12:46 AM it should be fine for this size 12-Feb-20 12:46 AM I'm just uncertain of how doable it would be to weld through with overlap 12-Feb-20 12:46 AM consult a qualified welder for better and more accurate opinion :P 12-Feb-20 12:47 AM why is weld-through needed? 12-Feb-20 12:48 AM to prevent virtual leaks from an internal gap 12-Feb-20 12:48 AM isn't virtual leak gonna be single or double digit millitorr? 12-Feb-20 12:48 AM or less 12-Feb-20 12:48 AM I don't need to get any lower than 1*10^-1 torr 12-Feb-20 12:49 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/nljEx-3E2CE.png 12-Feb-20 12:49 AM you don't want something like this to happen 12-Feb-20 12:49 AM if a virtual leak happens it's going to be a persistent air leak until it all drains out 12-Feb-20 12:50 AM I don't think I'm even getting past viscous flow at this point 12-Feb-20 12:50 AM high pressure wants to go to low pressure regardless 12-Feb-20 12:50 AM having chemistry cross-contamination wouldn't be the best, but I think it could be tolerable 12-Feb-20 12:51 AM air getting into your chemistry? 12-Feb-20 12:53 AM well it's a chloro-silane to -HO reaction... so ambient moisture will reduce the efficiency 12-Feb-20 12:53 AM since it will couple the silane 12-Feb-20 12:53 AM and I want to silane to react with the substrate surface 12-Feb-20 12:53 AM posted the formula I used to calculate wall thickness in #resources 12-Feb-20 12:53 AM another downside is the 15' length of stainless, of which I only need like 3 or 4' is $465 12-Feb-20 12:55 AM ouch 12-Feb-20 12:56 AM so I'd kinda like the PVC to get me where I need to go... but this is for a job that's already taking too long, and this coating is only one aspect of several other issues that still might arise 12-Feb-20 12:56 AM you could always go with regular steel or alu 12-Feb-20 01:04 AM hrmm, yeah, have to find a pipe supplier that isn't craigslist 12-Feb-20 01:04 AM did you ever weld PVC? 12-Feb-20 01:05 AM physically yes, chemically no 12-Feb-20 01:10 AM ah so you mean with glue/epoxy... not solvent 12-Feb-20 01:10 AM by melting it and glue/silicone 12-Feb-20 01:23 AM oh, isn't melting is "chemically welding" ? 12-Feb-20 01:23 AM or no, because it just causes the polymers to wrap around each other? not bond covalently? 12-Feb-20 01:31 AM I've worked on plastic models before with Model Masters plastic cement. It seems to liquify the plastic so that you can smoosh them together, and once it dries, the two separate pieces of plastic become one. That would be chemically welding, yeah? 12-Feb-20 01:38 AM @Laughing what's HSC? 12-Feb-20 02:19 AM This? http://www.halted.com/ 12-Feb-20 02:21 AM ^Yes 12-Feb-20 06:51 AM What are you pumping with? 12-Feb-20 06:51 AM Excuse me 12-Feb-20 06:51 AM The bot removed my comment 12-Feb-20 06:51 AM My forevac has about 150’ of 4” PVC. Connections have spilled solvent and primer all over the place. It gets to 1E-3, but when pumping with a scroll it took a week to hit 1E-2 torr the first time. Now it’s about half an hour, but we have a bigger pump that can do it in a minute 12-Feb-20 10:23 AM RIP HSC 12-Feb-20 10:23 AM heywaitasec 12-Feb-20 10:23 AM @Laughing do we know each other? :D 12-Feb-20 10:32 AM @idmb tried both a little and big trivac.. little hits 10-3 torr with gauge hooked directly in seconds, the big 10-2 in seconds... It's got about 8 ft of what looks like 1/4" or less ID tubing between the pump and chamber base plate 12-Feb-20 10:32 AM At this point i think I'm gonna find a big piece of plastic to attach a kf fitting to the bottom of, and glue that to the bottom of the pipe, and get a bigger ID hose, shorter length 12-Feb-20 10:34 AM your chamber is basically a virtual leak itself, isn't it? 12-Feb-20 10:34 AM I've used 1/8" ID tubing for very small volumes before, but never with the aim to go below ~1E-1 torr 12-Feb-20 10:34 AM Guess it's all calculable 12-Feb-20 10:35 AM Well it's 10" diameter inside and almost 4ft tall 12-Feb-20 10:35 AM So not quite small volume 12-Feb-20 10:35 AM Yeah i only want to get to 10-1 torr 12-Feb-20 10:35 AM My intuition is completely unadjusted to reality, but it seems 8 torr is way higher pressure than a virtual leak 12-Feb-20 10:40 AM what's the pump pumping speed? 12-Feb-20 10:40 AM I've got a syringe needle sticking through a rubber stopper, and when i pull the plug out from the atmospheric side, the pressure rises at like 0.1 torr per second or two 12-Feb-20 10:40 AM Hmm, not sure 12-Feb-20 10:40 AM It's a big pump tho, trivac d8b 12-Feb-20 10:40 AM Google says 6.9 cfm 12-Feb-20 10:40 AM Or 6 12-Feb-20 10:41 AM k about 0.5 L/s 12-Feb-20 10:41 AM and your vacuum line is throttling that to about 0.1 12-Feb-20 10:41 AM should still be fine 12-Feb-20 10:41 AM 0.01 L/s at 0.1 torr 12-Feb-20 10:43 AM Seems like 8 torr is right on the edge of viscous flow ending 12-Feb-20 10:43 AM no 12-Feb-20 10:43 AM So maybe something to do with the tubing size and length? 12-Feb-20 10:43 AM anywhere from like 1E-2 and 10 Torr is "none of this math works all that well" 12-Feb-20 10:43 AM (in addition to leaks) 12-Feb-20 10:43 AM your tubing size + length isn't helping but is probably not the cause 12-Feb-20 10:43 AM you have a pretty big leak still 12-Feb-20 10:44 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/15815330471418721017816701437479-2FB53.jpg 12-Feb-20 10:44 AM 8 torr is just above a pascal, i think 12-Feb-20 10:44 AM Which is slightly colored here 12-Feb-20 10:44 AM Yeah you're in that regime 12-Feb-20 10:44 AM There's still lots of viscous effects though 12-Feb-20 10:45 AM Oh god, I'm way off, 1000 pascal is 7.5 torr 12-Feb-20 10:45 AM just no nice equations to model it 12-Feb-20 10:45 AM haha oh yeah 12-Feb-20 10:45 AM 760 torr = 100kpa 12-Feb-20 10:46 AM Seriously need a good lab poster that shows a nice number line to convert all these units 12-Feb-20 10:46 AM or 12-Feb-20 10:46 AM crucify anyone who uses anything else 12-Feb-20 10:46 AM Haha 12-Feb-20 10:46 AM Natural selection 12-Feb-20 10:46 AM we use bar, torr, and nothing else 12-Feb-20 10:46 AM bar for > 0.5atm 12-Feb-20 10:46 AM anyways you're throttling your pump quite a bit 12-Feb-20 10:46 AM maybe you don't care, but your chamber is quite big... 12-Feb-20 10:48 AM Mmm, yeah some biggwr tubing and getting rid of the questionable brass Tee's is first on my list 12-Feb-20 10:48 AM The base plate is aluminum too, and wavy from machine marks 12-Feb-20 10:48 AM I was thinking the aluminum oxide layer could be causing issues, but that seems like a much much higher vacuum issue 12-Feb-20 10:48 AM The tees use some paste white stuff to join them, idk of theres PTFE paste 12-Feb-20 10:48 AM But goop seems like it would not be leaking at this level 12-Feb-20 12:02 PM What's the downside of using carbon steel as a chamber? 12-Feb-20 12:02 PM Any offgassing of rust? 12-Feb-20 12:02 PM Screenshot (Feb 12, 2020 12:04:18 PM) 12-Feb-20 12:02 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_20200212-120418-7E9EB.png 12-Feb-20 12:04 PM literally anything that won't collapse works as a rough vacuum chamber 12-Feb-20 12:05 PM Well just ordered new 3/4" tubing and kf adapters, so that's a step forward i think 12-Feb-20 12:05 PM it goes with diameter^4 12-Feb-20 12:05 PM so that's a nice upgrade from 0.25" 12-Feb-20 12:05 PM I do literally use PVC sewer pipe for this though 12-Feb-20 12:05 PM dirt cheap works fine 12-Feb-20 12:07 PM I got some wire reinforced PVC from dudadiesel on Amazon prime 12-Feb-20 12:07 PM $18 for 10' 12-Feb-20 12:07 PM The kf16 fitting will still be the limit tho, i think it's less than 3/4" 12-Feb-20 12:08 PM aperture effect really doesn't matter much 12-Feb-20 12:08 PM I also got a tee and a leak valve and isolation valve 12-Feb-20 12:08 PM the aperture effect is much more of a molecular flow thing than viscous flow 12-Feb-20 12:08 PM Hopefully the isolation valve is just an aperture 12-Feb-20 12:08 PM In likeness 12-Feb-20 12:08 PM https://www.ebay.com/itm/USA-Ball-Valve-for-rough-vacuum-isolation-both-sides-KF16-25-40-50-flange-SS/223800501507 12-Feb-20 12:10 PM my system is literally: 1. pump with ISO100 inlet 2. ISO100 to KF50 adapter 3. KF50 cross 4. Four 1' to 2' KF50 bellows going to four rigid 4" ID PVC tubes (homemade adapter end caps) 5. Four 4" ID PVC tubes going ~35' each 6. Four KF50 bellows to turbopumps, with a valve and gauge in the way 12-Feb-20 12:10 PM Haha I tried to buy the same valves but they cancelled the order on me and said I had to pay more for shipping so I just bought edwards ones from KJL 12-Feb-20 12:11 PM oh hey someone went with kf50 as well 12-Feb-20 12:11 PM \o/ 12-Feb-20 12:11 PM PVC though 12-Feb-20 12:12 PM iGX600L 12-Feb-20 12:12 PM offgassing doesn't matter 12-Feb-20 12:12 PM Wow 35ft 12-Feb-20 12:12 PM lol just crush it with pumping speed 12-Feb-20 12:12 PM It's a $30,000 pump in a separate room from the experiments 12-Feb-20 12:12 PM I told the seller i could come pickup tomorrow if they couldn't get the package here by Saturday... They're only like an hour drive or so 12-Feb-20 12:12 PM even with 4" ID forevac lines, we're throttling the pump in conductivity 12-Feb-20 12:12 PM for my system I needed about 90m^3/hour forevac, and the IGX600L was ~10% more expensive than the iGX100L 12-Feb-20 12:12 PM iirc my lines throttle it to ~120m^3/hour 12-Feb-20 12:12 PM KF50 is an oddball 12-Feb-20 12:12 PM I already had all the bellows I needed, otherwise I probably would have used ISO100 right up until I hit the turbos 12-Feb-20 12:12 PM In hindsight, since the pump is water-cooled I wish I had just built a noise baffle box and put it beside my experiment 12-Feb-20 12:12 PM but then I still would have had to run the 4" PVC to the other apparatus so eh 12-Feb-20 12:16 PM I need to find a university that would be willing to let someone with just a HS diploma run a bleeding edge lab 12-Feb-20 12:16 PM and fund it 12-Feb-20 12:16 PM I'll even publish in journals! (*assuming I can get a phd to stuff all the formulas and math into the paper because I'm very empirical) 12-Feb-20 12:17 PM A lot of this is empirical. We look at papers with relevant experiments, try to find how things scale, and expand on that 12-Feb-20 12:17 PM That's what I want to do with the x-ray source 12-Feb-20 12:17 PM I want to apply the papers I've found into a practical device 12-Feb-20 12:19 PM honestly though you could probably get a job as a lab tech / vacuum "scientist" at a university if you wanted. 12-Feb-20 12:19 PM The bar is low People don't like grunt work. 12-Feb-20 12:19 PM Heh, if only I lived near a university where something like this happens 12-Feb-20 12:19 PM (I also can't work where I live because of a thing I did voluntarily) 12-Feb-20 12:22 PM time to move to silicon valley 12-Feb-20 12:23 PM the moving costs and accommodation for a month would leave me broke 12-Feb-20 12:23 PM unless I get a well paying vacuum tech job :P 12-Feb-20 12:30 PM tbh a job for KJL would be fun 12-Feb-20 12:30 PM would be hard to get a job without a degree I imagine 12-Feb-20 12:31 PM I don't think so, honestly. 12-Feb-20 12:31 PM for a foreigner 12-Feb-20 12:32 PM They're pretty into the whole "company run by real people" idea 12-Feb-20 12:32 PM well, I sure am real 12-Feb-20 12:32 PM not sure if a company like that would sponsor someone across the world to work for them 12-Feb-20 12:32 PM would be very neat 12-Feb-20 12:32 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-E540D.png 12-Feb-20 12:32 PM their current job list is pretty bland though 12-Feb-20 12:33 PM detail technician 12-Feb-20 12:33 PM "rub stuff with a polishing cloth man" 12-Feb-20 12:33 PM Working on the design team of their process equipment division 12-Feb-20 12:33 PM would be a lot of fun I imagine 12-Feb-20 12:34 PM that's probably as much math as I could handle 12-Feb-20 12:35 PM math is nice 12-Feb-20 12:35 PM there are right answers and wrong answers 12-Feb-20 12:35 PM great, I'll put you in charge of all the math when I'm a millionaire 12-Feb-20 12:38 PM Why aren't there more companies that make a habit of poaching burnt-out grad students? 12-Feb-20 12:38 PM I'm not a grad student 12-Feb-20 12:38 PM Never went to uni :< 12-Feb-20 12:38 PM if you get poached, put in a word for me 12-Feb-20 12:40 PM I'm ~60% done ain't nothing stopping me now 12-Feb-20 12:45 PM I just got an internship at Phoenix LLC today. 12-Feb-20 12:45 PM Well actually I haven't taken the offer, need to sort out a few things. Not sure exactly what I'll be doing though... 12-Feb-20 12:45 PM I hope it's not going to be a lot of neutron transport simulations and deconvolution for their detectors 12-Feb-20 12:47 PM @Spirit I know people who live in Silicon Valley for super cheap... Roommates and making beans in a crock pot, essentially 12-Feb-20 12:47 PM hey congrats! :D 12-Feb-20 12:47 PM or, well, soon-to-be-congrats 12-Feb-20 12:48 PM @nmz787 I'd have to move to silicon valley though 12-Feb-20 12:48 PM and I've never been to the us, let alone lived there 12-Feb-20 12:49 PM I need to fill out a few forms 12-Feb-20 12:49 PM if I got hired with a stable job waiting for me there, I'd probably move 12-Feb-20 12:49 PM fully hired, paperwork, official offer, contracts, etc 12-Feb-20 12:49 PM and visa sponsorship lol 12-Feb-20 12:49 PM you can see how with these requirements hiring me suddenly becomes very unattractive 12-Feb-20 12:54 PM a lot of tech companies are certainly willing to pull those strings for the right candidate, i see it done all the time 12-Feb-20 12:54 PM think a lot of HR firms are well accustomed with that whole song and dance 12-Feb-20 12:55 PM Sure, but I think "right candidate" means either "lucrative phd grad" or "veteran with work experience" 12-Feb-20 12:55 PM I'm... a lucrative... no work experience... something. 12-Feb-20 12:55 PM Good at solving problems and coming up with new ideas, but I haven't done that really professionally besides a single totally unrelated industry 12-Feb-20 12:55 PM hard to convince 12-Feb-20 12:57 PM i wish i could speak to industries other than just tech-for-tech's-sake, because I know in that case, a sufficiently starry-eyed entry level candidate with past experience in the field -- even DIY/independent -- can sometimes be a solid foot in 12-Feb-20 12:57 PM lot easier to get independent coding/admin experience with computers than other fields, tho 12-Feb-20 12:57 PM when in doubt, apply anyways :D The worst they can say is no 12-Feb-20 12:58 PM I wrote a piece of software for the robotics industry that is very popular in a very small circle of people lol 12-Feb-20 12:58 PM Programmers have it so much easier 12-Feb-20 12:58 PM But then you work with hardware and handwaving something with this "physical presence" thing comes up 12-Feb-20 01:00 PM I have gotten my jobs with practical experience and my hobby projects 12-Feb-20 01:01 PM Try and apply! It doesn't hurt at all. This time last year I got the email equivalent of "lol no" from a HR person at Phoenix when I first applied 12-Feb-20 01:01 PM Then three months later they actually hired their first foreign employee, who's working remotely, and my project caught the attention of their CEO, so the doors were open 12-Feb-20 01:02 PM where would I even begin to apply 12-Feb-20 01:02 PM D: 12-Feb-20 01:02 PM I don't know where I want to work for this type of thing 12-Feb-20 01:04 PM relatable 12-Feb-20 01:04 PM Google is your friend, takes all of 30 minutes to fill out a typical application. Sure you'll get a lot of "no", but once you catch the attention of someone important impossible things can become possible 12-Feb-20 01:06 PM sometimes 'what would your dream job be?' -> working your way backwards can be useful. One slightly creepy but still useful route is to go on LinkedIn and find employees of a company you're interested in on who're doing things you're interested in, and seeing what their past jobs were like 12-Feb-20 01:06 PM me i'd love to be working on accelerators or fusion research or some kinda nuclear engineering, and you can find folks who've taken all kinds of routes to get there, through electronics or school or universities or medical companies or etc 12-Feb-20 01:10 PM Yeah a former co-worker of mine took a job at a medical devices company has he had a thing for radioactive things. He got on the testing side of things. Considering that he's an electronics designer who previously worked at a satellite company doing design verification before joining my former employer. 12-Feb-20 02:34 PM Apparently getting pretty much any work visa requires that I have a degree and relevant work experience 12-Feb-20 02:34 PM Ouch. 12-Feb-20 02:43 PM Maybe I should find a european or US college/uni that offers remote bachelors or something... not sure if I could suffer through math heavy classes but I could at least try 12-Feb-20 02:44 PM 'Experience + degree' is just how all the major companies are spinning it now. Ive taken it to be code for "unless you're a diy rockstar or a grad student or someone we already know, don't bother." But that might be a very pessimistic view on it compared to some other people's experiences 12-Feb-20 02:44 PM It's less for finding a job and more for getting a visa to work lol 12-Feb-20 02:44 PM Work visas for quite a few countries basically squeeze down to "if you're not a super-genius, you need a degree to get the visa" 12-Feb-20 02:46 PM Normally there's openings all the time for certain positions, but those are the ones that work like how I described. When they're actually looking to hire fresh blood, they'll do a hiring spree. It's dependent on company, but it's usually October November for Google and Maxim, based on my experience, and then another company I tried for always hires new grads at the end of summer on a big hiring day for some reason. 12-Feb-20 02:47 PM You can buy your way into Canada through Quebec 12-Feb-20 02:47 PM I've been told by a few Canadian migrants(who are from here) that there's not much opportunity there 12-Feb-20 02:47 PM Also, Joby just got 600M shoved into it, and they're hiring all over the place if you want to work on air taxis. 12-Feb-20 02:48 PM It's a legal requirement for the H1B visa to have a degree, or there's massive hoops to jump through 12-Feb-20 02:48 PM Again, those are all big companies I'm talking about, because that's all that's revealed to local college kids. 12-Feb-20 02:49 PM could start a company elsewhere, make lots of money and then transfer myself to a new office based on proprietary knowledge 12-Feb-20 02:49 PM but what I find funniest is that getting married bypasses 100% of the strict requirements 12-Feb-20 02:49 PM married? come right on in 12-Feb-20 02:50 PM So do that 12-Feb-20 02:51 PM eventually, but y'know, can't control the heart, yadda yadda 12-Feb-20 02:51 PM Using marriage as a legal tool to bypass border laws sounds extremely gross to me. 12-Feb-20 02:51 PM yeah, fictitious marriages are sucky and I am never doing that 12-Feb-20 03:05 PM The limit of the H1-B visa lottery is exactly why I want to use up the OPT time under F1 student visa as much as possible 12-Feb-20 03:06 PM H1-B is not a lottery 12-Feb-20 03:07 PM Being born here is 12-Feb-20 03:07 PM Is general meant to be vacuum oriented? 12-Feb-20 03:10 PM Yeah probably best to go to #off-topic-thats-sometimes-on-topic 12-Feb-20 03:19 PM <__ice9#6039> H1-B is a lottery. An old roommate took like 3 years to finally get one and in the meantime was using OPT and then a questionable diploma-mill remote-college to maintain an F-1 student visa while still working. 12-Feb-20 03:19 PM <__ice9#6039> He did finally make it though. 12-Feb-20 03:19 PM <__ice9#6039> U.S. immigration system is a complete mess 12-Feb-20 03:19 PM <__ice9#6039> He already had a master's degree in something infosec related at the time. 12-Feb-20 07:14 PM So I can get ruby substrate that's 0.5mm thick... 100um would be much better 12-Feb-20 09:37 PM @__ice9 re buckling, wouldn't that calculation have taken that into consideration for their safety factor or whatever? 12-Feb-20 09:37 PM Or are you just saying, hope for the best expect the worst? 12-Feb-20 11:45 PM well this is odd - connecting EXDC160 to EXT255Hi prevents me from connecting KF25 clamps to the interstage or outlet ports 12-Feb-20 11:55 PM that sounds wrong 12-Feb-20 11:58 PM i agree. i'm probably doing something wrong 12-Feb-20 11:58 PM does it fit in any other way? 13-Feb-20 12:00 AM no, it's keyed 13-Feb-20 12:00 AM this isn't my picture, just one from goog images, but you can see it's somewhat over that left port, and my clamps won't fit on the right port either 13-Feb-20 12:00 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/4593046-2_1739574_4593046_74811-CF92F.png 13-Feb-20 12:01 AM The clamps should definitely fit 13-Feb-20 12:01 AM an extension would solve it 13-Feb-20 12:01 AM I think you can unscrew both ports though 13-Feb-20 12:01 AM i mean, won't fit with the supply there, but maybe my clamps are just too big 13-Feb-20 12:03 AM you could try extending the power supply wires just a bit 13-Feb-20 12:03 AM or rotating the connector 13-Feb-20 12:06 AM ok looks like i can get one on the left but not on the right, clamp is just too big - will look for smaller clamp 13-Feb-20 12:06 AM i'll see if anything is rotatable 13-Feb-20 12:07 AM carefully unscrew the 4 screws on the connector and rotate it 90 degrees to the left 13-Feb-20 12:07 AM ahh 13-Feb-20 12:07 AM there should be enough slack wire inside to do that 13-Feb-20 12:07 AM but carefully 13-Feb-20 02:55 AM yeah there's a few setscrews on the EXDC controller, just undo those and you can gently rotate it while it's latched on the pump. in the picture above it'd rotate CCW 13-Feb-20 02:55 AM s/undo/loosen 13-Feb-20 04:44 AM <__ice9#6039> Mine is rotated downward fwiw 13-Feb-20 04:44 AM <__ice9#6039> This leaves both KF25 ports accessible, but requires the pump to be mounted on a small platform or used sideways. This model of pump can run with the pump at any angle from upward-pointing to horizontal, but not below horizontal. 13-Feb-20 09:09 AM Disposable income time! Just had an interview for a student job next semester. 13-Feb-20 09:16 AM yay 13-Feb-20 11:32 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/AlWindow-DFE1E.jpg 13-Feb-20 11:32 AM ahh thanks all 13-Feb-20 11:33 AM is that beryllium? 13-Feb-20 11:33 AM D: 13-Feb-20 11:33 AM since there was disgussion in this topic a few days ago 13-Feb-20 11:33 AM this is a 20mm window using 14um aluminiumfoil 13-Feb-20 11:33 AM mechanically sound and not leaky 13-Feb-20 11:33 AM very round. 13-Feb-20 11:33 AM nice @Leona! guessing it went well? 13-Feb-20 11:34 AM congrats ^^ 13-Feb-20 11:34 AM very round. @Spirit round but it looks worse than it is 13-Feb-20 11:34 AM after all thats the mechanically perfect shape 13-Feb-20 11:34 AM is it an x-ray window? 13-Feb-20 11:34 AM its roughly 3-4mm deep so not to extreme 13-Feb-20 11:34 AM yes, for testing viability 13-Feb-20 11:35 AM what's the mounting mechanism? 13-Feb-20 11:36 AM according to @GigaSquirrel the 14u will absorm half of the photons @ 5keV so its definitly an alternative to beryllium in home made stuff 13-Feb-20 11:36 AM its an old cf window and the mounting is high quality epoxy 13-Feb-20 11:36 AM the practical limit for microfocus NDT is roughly 15-20kev 13-Feb-20 11:36 AM one that has prooven never to give problems even under pretty good vacuum 13-Feb-20 11:36 AM which epoxy? 13-Feb-20 11:37 AM well, not nessercarely micro, just a general window 13-Feb-20 11:37 AM endfest 300 13-Feb-20 11:37 AM that looks cheap 13-Feb-20 11:37 AM im pretty sure any not totally cheap and filler free epoxy will be just as good 13-Feb-20 11:37 AM the issue is long term sealed tube stuff 13-Feb-20 11:38 AM its not expensive like dedicated vacuum epoxy, but it is not cheap 13-Feb-20 11:38 AM $15 for a small kit 13-Feb-20 11:38 AM I think 100g 13-Feb-20 11:38 AM roughly 1$/g 13-Feb-20 11:38 AM that's very reasonable 13-Feb-20 11:38 AM no 13-Feb-20 11:38 AM small kits are really small 13-Feb-20 11:38 AM not JB weld size 13-Feb-20 11:38 AM ah it's 2x15ml 13-Feb-20 11:38 AM http://www.modelshopleeds.co.uk/catalog/product_info.php?products_id=2701 13-Feb-20 11:38 AM (I'm not from the uk) 13-Feb-20 11:39 AM yeah, so roughly in that range 13-Feb-20 11:39 AM so other good epoxies will do 13-Feb-20 11:39 AM ones tht are made to bind completely and are not filled with volatile stuff 13-Feb-20 11:39 AM I want to know which epoxies would be suitable for high vacuum sealed tube air-vacuum barriers 13-Feb-20 11:40 AM this one is known to be food safe, good to 150°C and that way not containing unreacted products that are free to escape 13-Feb-20 11:40 AM so its my choice (and other peoples) for everything vacuum related that still involves a pump 13-Feb-20 11:40 AM if you want to seal it permanently im pretty sure you will not have a choice except buying the good stuff 13-Feb-20 11:40 AM (forgot the name) 13-Feb-20 11:42 AM torr-seal is also hysol ea 1c 13-Feb-20 11:42 AM it's not that expensive, but I don't think it's good for permanent 13-Feb-20 11:48 AM ah right 13-Feb-20 11:48 AM mh, to my knowledge argon lasers are sealed with torrseal 13-Feb-20 11:49 AM argon lasers are also quite high pressure 13-Feb-20 11:49 AM a few hundred mtorr afaik 13-Feb-20 11:50 AM well yes, but they do last for many decases and have to hold up to compareably rough conditions 13-Feb-20 11:50 AM i could imagine the glue is good enough for permanent, maybe at least with some baking 13-Feb-20 11:50 AM also something i allways wanted to try is first epoxying something and then metal coating 13-Feb-20 11:50 AM the coat can seal the polymers surface well enough 13-Feb-20 11:51 AM oh, sputtering over might actually work 13-Feb-20 04:24 PM Looking for a needle valve for venting to atmosphere 13-Feb-20 04:24 PM looking for npt ones that might be okay for vacuum use because that would make the most sense for me as far as cost at this point 13-Feb-20 04:24 PM not seeing much though, idk if it’s because npt valves aren’t very common for vacuum or what 13-Feb-20 04:39 PM @mike crb I ordered one of these yesterday https://www.ebay.com/itm/US-KF-Flange-Stainless-Steel-Vacuum-Vent-Valve-Or-Relief-Valve-For-Vaccum-System/223802783539 13-Feb-20 04:39 PM That seller has kf to npt adapters... 13-Feb-20 04:56 PM NPT vacuum gauges are used for rough vacuum all the time. 1/8" NPT Agilent 531 Thermocouples are a dime a dozen 13-Feb-20 05:39 PM Say I use an npt tc so that’s my main motivation 13-Feb-20 05:39 PM I would have to get new kf flange to accommodate that valve, where as if I get an npt valve I can just cheaply attach my thermocouple, a vent valve, and swagelok->1/8th npt adaptor to my setup 13-Feb-20 05:47 PM But this is for rough vacuum only, right? 13-Feb-20 05:48 PM 10-2 mtorr region 13-Feb-20 05:48 PM heh I also see none on ebay 13-Feb-20 05:49 PM Yeah only see high pressure stuff 13-Feb-20 05:49 PM well it is high pressure 13-Feb-20 05:49 PM needle valves are for high pressure 13-Feb-20 05:49 PM you use bellows sealed valves for vacuum if you care about small leaks 13-Feb-20 05:50 PM ah 13-Feb-20 05:52 PM Needle valves seal vacuum front to back fine 13-Feb-20 05:52 PM But leak through the stem 13-Feb-20 05:54 PM gotcha 13-Feb-20 05:54 PM something along these lines is what I was trying for 13-Feb-20 05:54 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-EA3D9.png 13-Feb-20 05:55 PM Those are the high pressure ones 13-Feb-20 06:07 PM Completely fine if your pump can handle the small leak. 13-Feb-20 06:07 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-EFBED.jpg 13-Feb-20 06:07 PM I go KF - NPT - Valve - KF 13-Feb-20 06:07 PM that way I just have one tee that has an N2 line + scroll pump + gauge that I move around between systems for prepumping and venting 13-Feb-20 06:07 PM and I'm only using an NPT valve because we had a bucket of them + NPT- KF adapters 13-Feb-20 06:07 PM a KF valve would be better 13-Feb-20 06:14 PM yeh if it was a little cheaper I’d definitely getting kf flange + valve 13-Feb-20 06:39 PM $18 isn't cheap enough? 13-Feb-20 06:39 PM When you said"npt tc" what's tc mean? 13-Feb-20 06:39 PM Thermocouple? 13-Feb-20 06:42 PM Presumably 13-Feb-20 07:23 PM yeh thermocouple 13-Feb-20 07:23 PM and that valve is cheap but would have to get some more kf stuff besides just the valve 13-Feb-20 07:23 PM may end up going that way though, would probably make more sense to spend a bit more and not risk the leaks 13-Feb-20 07:40 PM Kf is real nice 14-Feb-20 03:57 AM Soooo sanded the PVC pipe flat tonight on both ends... Used a plate of glass and soapy water to see high and low spots, and kept sanding for hours... Man if I ever had to make lenses, I might go crazy. Or hope there's a better way 14-Feb-20 03:57 AM Used PVC primer and bonder (methyl ethyl ketone, tetrahydrofuran, PVC resin added in the bonder) to bond a 1/4" PVC plate to the bottom 14-Feb-20 03:57 AM Measured the ID and OD of the top of the pipe at 25cm and 28cm... Iso250 seems to have lip ID 25.76cm and lip OD 26.1cm 14-Feb-20 03:57 AM https://www.lesker.com/newweb/flanges/flanges_technicalnotes_iso_1.cfm 14-Feb-20 03:57 AM So can I use that? Can this "lip" be in between the flange face (pipe face and bell jar lip for me)? 14-Feb-20 03:57 AM I'd need to figure out a way to clamp, I was thinking find some triclamp stuff and maybe it could be zip-tied on to place things, then I epoxy the clamp bottoms in place (on the pipe). The bell jar has a lip that possibly could be a clamp-able surface 14-Feb-20 03:57 AM Definitely going to use the newton rings/make a pipe lip flat activity as a punishment for my kid, if he ever deserves such a thing. 14-Feb-20 08:39 AM Happened to have had my chamber "off" for the past week, looking at the pressure logs it leaks ~5 torr / day. There are eight NPT connections, about 20 KF connections, and 40 CF connections. All of the valves sealing it off right now are proper bellows vacuum valves. 14-Feb-20 08:39 AM and the volume is pretty big, something like three 10" CF crosses in a row 14-Feb-20 08:39 AM Oops tagged nmz when I meant @mike crb 14-Feb-20 10:27 AM @idmb since you mentioned using iso100... Can you clamp the "lip" lesker talks about? 14-Feb-20 10:28 AM Not sure what you mean 14-Feb-20 10:28 AM it's basically just a larger KF connection 14-Feb-20 10:29 AM Does the lip kjl mentions need to be inside the pipe? 14-Feb-20 10:29 AM Or can it be withing the sealing faces? 14-Feb-20 10:29 AM either is fine 14-Feb-20 10:29 AM would make no difference 14-Feb-20 10:29 AM Hmm, so with kf the ring is inside the pipe, i.e. doesn't get clamped 14-Feb-20 10:30 AM no 14-Feb-20 10:30 AM the ring has a lip too 14-Feb-20 10:30 AM here I have one on my desk 14-Feb-20 10:30 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-40E67.jpg 14-Feb-20 10:30 AM that's with the O ring and retention ring removed obviously 14-Feb-20 10:30 AM the little step sticking up (symmetric on the bottom) goes either into the pipe or into a groove on your flange/face 14-Feb-20 10:30 AM and then the wider part gets clamped between the two flat faces 14-Feb-20 10:30 AM and the o ring is on the outside of that with a larger thickness than the height of that wider part 14-Feb-20 10:30 AM and then there's a retention ring on the outside that just stops the o ring coming off this assembly because it's annoying to put them back on 14-Feb-20 10:30 AM So long as the little step (alignment lip / whatever you want to call it) is not tightly in a groove (creating a virtual leak) and is not clamping, it should be good to go 14-Feb-20 10:39 AM the lip is for centering, the thickness is for the proper squish 14-Feb-20 10:40 AM Ah so the lip can't be clamped in between the sealing faces it seems 14-Feb-20 10:40 AM It looks pretty tall 14-Feb-20 10:40 AM correct 14-Feb-20 10:40 AM your groove must be deeper than it is tall 14-Feb-20 10:40 AM :( I think it won't work for my pipe then 14-Feb-20 10:40 AM and must be wider than it is thick 14-Feb-20 10:40 AM why? 14-Feb-20 10:40 AM what is your pipe made of? 14-Feb-20 10:40 AM Measured the ID and OD of the top of the pipe at 25cm and 28cm... Iso250 seems to have lip ID 25.76cm and lip OD 26.1cm 14-Feb-20 10:41 AM lip ID doesn't matter 14-Feb-20 10:41 AM there's a maximum lip ID but no minimum lip ID 14-Feb-20 10:41 AM Hmm, doesn't make sense 14-Feb-20 10:41 AM You'd have to cut the inside ring then, and bend it? 14-Feb-20 10:42 AM no? 14-Feb-20 10:42 AM Or are you saying you can't remove part of your pipe? 14-Feb-20 10:42 AM If my pipe inner diameter is 250 mm, but the lip is at 257.6mm... it would be sitting on the face of the sealing surface 14-Feb-20 10:43 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-D9493.png 14-Feb-20 10:43 AM you just need to cut out a small step in your pipe 14-Feb-20 10:43 AM Right, it's huge and I don't know anyone with a lathe that can handle it... Also the length is almost 4ft 14-Feb-20 10:43 AM you can just buy a weldable flange 14-Feb-20 10:43 AM or machine it separately 14-Feb-20 10:43 AM Maybe a router would work? 14-Feb-20 10:43 AM Can't weld a flange to PVC 14-Feb-20 10:44 AM solvent weld 14-Feb-20 10:44 AM you can get 1" plates of PVC 14-Feb-20 10:44 AM I could only get 1/4" locally yesterday 14-Feb-20 10:44 AM PVC still sucks, get steel or stainless 14-Feb-20 10:44 AM Used that for the bottom 14-Feb-20 10:44 AM Saw a piece of steel pipe yesterday too... 14-Feb-20 10:44 AM Friggin heavy 14-Feb-20 10:44 AM 50lbs per linear ft 14-Feb-20 10:45 AM 1/4” would work for this 14-Feb-20 10:45 AM Since it would be supported by the bigger piece 14-Feb-20 10:46 AM Would a CNC cut groove be smooth enough for good sealing? 14-Feb-20 10:46 AM a rigid mill, yes 14-Feb-20 10:46 AM For what kind of vacuum pumped by what? 14-Feb-20 10:46 AM 6cfm trivac 14-Feb-20 10:46 AM 100 mtorr 14-Feb-20 10:46 AM With 3/4” hose? 14-Feb-20 10:47 AM Got it in today (3/4")! Waiting on ebay shipment for rest of parts for the new hose 14-Feb-20 10:47 AM And for holding the mating flange what were you planning to do? 14-Feb-20 10:48 AM I mentioned last night 14-Feb-20 10:48 AM Thinking triclamps epoxied on 14-Feb-20 10:48 AM But was kinda hoping atmospheric pressure would just work 14-Feb-20 10:48 AM My loadlock works with an o ring and just the weight of the plate lid 14-Feb-20 10:48 AM (on my FIB) 14-Feb-20 10:48 AM On another topic, i mixed hysol 1c last night then degassed it...saw a vapor cloud come out 14-Feb-20 10:48 AM Hopefully that wasn't required vapor for hardening 14-Feb-20 10:51 AM wait what's going on this connection? 14-Feb-20 10:51 AM do you have a sketch of the whole system? 14-Feb-20 10:52 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191229_232022-CFAA9.jpg 14-Feb-20 10:52 AM Old pic, now the bottom is replaced with solvent welded PVC plate 14-Feb-20 10:52 AM The kf flange on the side has been epoxied in 14-Feb-20 10:52 AM That's a degassing plastic bell jar on top 14-Feb-20 10:53 AM what's that top connection? 14-Feb-20 10:53 AM Err, that was actually a salad bowl which cracked, it's replaced with a plastic bell jar now 14-Feb-20 10:53 AM The mating surface has been sanded flat last night, reasonably well, using a plate of glass and water to check for level/flatness 14-Feb-20 10:53 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image-20200213_202352-0E236.jpg 14-Feb-20 10:56 AM and just a sheet of rubber? 14-Feb-20 10:57 AM Silicone sheet in between the pipe and Bell jar, yes 14-Feb-20 10:57 AM interesting 14-Feb-20 10:57 AM I think the other guy at the job used rtv to join the sheet to the bell jar 14-Feb-20 10:57 AM The epoxy is curing on the kf, so I'll probably wait until tomorrow to try pumping 14-Feb-20 10:58 AM I don't like epoxy 14-Feb-20 10:58 AM It was a kf to threaded 14-Feb-20 11:26 AM I finally pulled the trigger on a cryopump with compressor, helium lines and heater blanket 14-Feb-20 11:26 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/s-l1600-8DC57.png 14-Feb-20 11:26 AM @GigaSquirrel I believe this is the same one that they couldn't ship to Germany 14-Feb-20 11:26 AM hahaha I was just going to say XD 14-Feb-20 11:26 AM They did offer free freight shipping to a US commercial address at least 14-Feb-20 11:26 AM congrats, glad it stayed in the server 14-Feb-20 11:26 AM So it's a pretty good deal? Considering the size of this thing 14-Feb-20 11:27 AM how much did you pay for the thing? 14-Feb-20 11:27 AM ~$550 shipped 14-Feb-20 11:27 AM Many problems to sort out though 14-Feb-20 11:27 AM ...so they add what they lost through me 14-Feb-20 11:28 AM Yep... What was it? $250? 14-Feb-20 11:28 AM 175 14-Feb-20 11:28 AM That would've been an amazing deal 14-Feb-20 11:28 AM I think I'll machine my own 10" ASA to ISO something adaptor 14-Feb-20 11:28 AM But before then I need to ensure I can move this thing, the whole freight weighs about 450 lbs 14-Feb-20 11:30 AM yeah it would have been... 14-Feb-20 11:30 AM guess you still got a good deal 14-Feb-20 11:30 AM 460 iirc 14-Feb-20 11:31 AM If it works! I couldn't get a picture of the inside of the cryopump, it might be nasty. 14-Feb-20 11:31 AM was 550 for just the compressor or for the whole compressor/pump/hoses combo? 14-Feb-20 11:31 AM The whole shebang 14-Feb-20 11:31 AM that's a nice deal 14-Feb-20 11:31 AM the compressor still has He pressure inside, so that's a good sign 14-Feb-20 11:32 AM do these quickconnects lose gas on actuation? 14-Feb-20 11:32 AM let us know what the UHP helium fill ends up costing 14-Feb-20 11:32 AM they don't @Spirit 14-Feb-20 11:32 AM @LRM 4.6 is perfectly fine 14-Feb-20 11:32 AM i still have not gotten a price for it to try out mine...too many things going on and i am a bit scared to find out how much it costs 14-Feb-20 11:34 AM Oh also it's 3 phase 14-Feb-20 11:34 AM Almost certainly 14-Feb-20 11:34 AM yeah for sure 14-Feb-20 11:34 AM a friend guesstimated 8 kW 14-Feb-20 11:35 AM That sounds too high 14-Feb-20 11:35 AM I found a larger comparable model on a Japanese listing that's ~3.5 kW 14-Feb-20 11:35 AM Ah, this is the closest model I can find 14-Feb-20 11:35 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/gas2003-5161-C5359.png 14-Feb-20 11:36 AM my small compressor (14x14x28") is 1.2kW 14-Feb-20 11:36 AM the small single phase ones are 2 kW 14-Feb-20 11:36 AM oh, huh 14-Feb-20 11:36 AM well, I'm not an expert on this area 14-Feb-20 11:36 AM anyways, good luck! 14-Feb-20 11:37 AM I'll certainly need it! 14-Feb-20 11:45 AM Daikin USA won't give any info on this pump for me. It seems to have merged into a newer series of cryopumps from SHI/Nagase in the mid-90s 14-Feb-20 11:45 AM Time to muster up what little Japanese I know and ask around 14-Feb-20 11:45 AM But someone in the US should know about this pump, given that its overhaul plate state the last full service was 2013 14-Feb-20 11:45 AM It's a BIG pump 14-Feb-20 11:45 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/s-l1600-C8FBD.png 14-Feb-20 11:45 AM Would appreciate any info on this 14-Feb-20 11:45 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/s-l1600-D0370.png 14-Feb-20 12:44 PM the helium fill should be pretty cheap 14-Feb-20 12:44 PM a full size 2000PSi tank of 6.0 is ~$2000 CAD 14-Feb-20 12:44 PM iirc 14-Feb-20 12:45 PM I can get a 150 bar 40l tank of 6.0 here for around $600-750 14-Feb-20 12:45 PM (just the fill, the UHP clean tank is another $200ish if you buy) 14-Feb-20 12:46 PM how tall is that? 14-Feb-20 12:46 PM no idea 14-Feb-20 12:46 PM they're the regular 40l cylinders 14-Feb-20 12:46 PM like person-height? 14-Feb-20 12:46 PM yeah 14-Feb-20 12:46 PM very short person height 14-Feb-20 12:47 PM neat 14-Feb-20 12:47 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/40l-oxygen-cylinder-5A068.png 14-Feb-20 12:47 PM these kinds 14-Feb-20 12:47 PM 6.0 purity? 14-Feb-20 12:47 PM yeah 14-Feb-20 12:47 PM Weird 14-Feb-20 12:47 PM but it's special order 14-Feb-20 12:47 PM I wonder why praxair charges us so much 14-Feb-20 12:47 PM because you're a university lol 14-Feb-20 12:47 PM you get scalped just as you scalp 14-Feb-20 12:53 PM Yeah you want five nines helium for the cryos 14-Feb-20 12:53 PM and want to purge with it 14-Feb-20 12:53 PM Or that's what we did. 14-Feb-20 12:53 PM Kainda sad that I nolonger work with vacuum and cryogenics. But with JTAG and BSDL :( 14-Feb-20 12:55 PM the $30,000 cryocoolers you can buy come with 99.995% 14-Feb-20 12:55 PM I think one of ours is 20 years old and hasn't ever been serviced / refilled 14-Feb-20 12:56 PM A researcher at my school just bought something like that for an ultracold neutron experiment 14-Feb-20 12:56 PM It's a custom-built set-up, somewhere around ~$50000 plus 3 month lead time 14-Feb-20 12:57 PM if it's dry helium, you should be fine with 5.0 or even 4.0 14-Feb-20 12:57 PM we ordered my big turbo last january and I still haven't turned it on 14-Feb-20 12:58 PM That 50K cooler is nothing fancy though, 20K 2 stage GM cooler 14-Feb-20 12:58 PM Pretty big inside a custom enclosure 14-Feb-20 12:58 PM Last January as in January 2019? 14-Feb-20 12:59 PM yeah 14-Feb-20 12:59 PM What's holding you back? 14-Feb-20 01:00 PM the system is two systems perpendicular to eachother sharing a detector, with a new laser system too that can do a bunch of stuff on the optical table without the vacuum system 14-Feb-20 01:00 PM like my cryocooler arrived in July I think, it's unboxed but I haven't connected the helium lines yet. Hasn't been priority 14-Feb-20 01:00 PM (This is what happens when you have 1 grad student running their own lab with nobody else involved) 14-Feb-20 01:01 PM My fear of my own turbo, its water-cooling system and complicated control interface held me back for a couple of months. But I think now's the time 14-Feb-20 01:02 PM my hacky PLC system is almost done 14-Feb-20 01:02 PM set to make all valves NC, refuse to open valves if pressure differential is too high, turn turbos off if pressure is too high, etc 14-Feb-20 01:02 PM Ah that's nice 14-Feb-20 01:03 PM also automatic forevac switching 14-Feb-20 01:03 PM for if the main pump sends an error signal 14-Feb-20 01:03 PM IDK should be good unless I invert something and it's set to open my gate valves to my turbos at ATM 14-Feb-20 01:05 PM Test before you switch your turbo on lol 14-Feb-20 01:05 PM I can't test every idiotic thing though 14-Feb-20 01:05 PM the important part is making it so that no cable getting unplugged does something stupid 14-Feb-20 01:05 PM and having it so that if something gets closed because of a pressure problem, it requires an intentional "please open me" signal to open it again rather than just suddenly opening it the instant that gauge reads a good pressure again 14-Feb-20 01:05 PM stuff like that 14-Feb-20 01:05 PM IDK I can break two turbos before the damage costs more than paying to have a proper system installed 14-Feb-20 01:10 PM Oh I'm jealous... Hey I might be looking to get rid of my 1600 L/s turbo if the cryopump works, fits on my chamber and I can find somewhere with 3 phase to run it 14-Feb-20 01:45 PM Testing firmware revisions was fun 14-Feb-20 01:45 PM Only time I have heard what sounds a hipace80 makes when it's at full speed when a kf40 valve to a (small) atmospehric pressure chamber is opened. 14-Feb-20 01:45 PM It sounded unhappy. 14-Feb-20 01:45 PM In an angry way 14-Feb-20 01:45 PM That abused thing is likely still being used to test firmware revisions 14-Feb-20 01:45 PM Still shaking my head at it's mountings too ( a single m6 bolt at the bottom) 14-Feb-20 01:45 PM Oh well, not my turbo, not my rodeo and no longer my work either! 14-Feb-20 01:45 PM Even if it was I who mounted it with that single bolt, I had the papertrail for it. So it was officially not my fault when it broke. 14-Feb-20 06:50 PM Joined the server. 14-Feb-20 07:00 PM Hi @ebowden , nice to see you here 15-Feb-20 08:59 AM I've got this weird oil cap on a HVAC mech pump I bought a while ago. Is there a particular name for this kind of cap and how can I get it off? 15-Feb-20 08:59 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20200215_115808-8F8AB.jpg 15-Feb-20 09:33 AM The 710 cap. 15-Feb-20 09:33 AM I believe you can just push on it and rotate 15-Feb-20 02:24 PM Or is it a squeeze the side type of cap like on an over the counter pill bottle? 15-Feb-20 02:27 PM could be that too 16-Feb-20 02:33 AM @Spirit been super enjoying that Huygens Optics channel this weekend. Again, great find and thanks for sharing. 16-Feb-20 11:44 AM what sort of cooling systems do you all use? I'd like something quiet that I can hook up to multiple projects -- any fun DIY systems that are suggested? 16-Feb-20 11:50 AM Cooling what? 16-Feb-20 11:54 AM magnetron, vacuum pump, peltiers 16-Feb-20 11:56 AM how much heat? those can each vary quite a bit 16-Feb-20 12:00 PM i'm not sure, just curious what people are generally using for cooling 16-Feb-20 12:03 PM we have a 10C glycol/whatever mixture that comes from the building at 90PSI, that goes to a panel which cools our roughing pump, the compressor for a sumitomo cold head, one giant turbopump (that doesn't need much cooling), and a big fan coil unit we use when the building HVAC inevitably breaks every summer. 16-Feb-20 12:03 PM We then have two air-cooled water recirculating chillers (polyscience, 0.75 HP cooling power I believe?) that cool the diodes on our YAGs, and also cool the peltier coolers that cool our TiSaphs. 16-Feb-20 12:03 PM And then there's also an Edwards 40 rotary vane pump in that room. 16-Feb-20 12:03 PM The air-cooled chillers and edwards 40 generate quite a lot of heat, so all of this is in a separate room from what they're pumping/cooling. This also helps cut down noise in the lab, that stuff is loud. 16-Feb-20 12:03 PM and there's also a separate 200W chiller that does the diode for our oscillator 16-Feb-20 12:22 PM ahh 16-Feb-20 12:22 PM what kind of company? 16-Feb-20 12:24 PM University research, HVAC would work better otherwise 16-Feb-20 12:24 PM But those big chillers are standard for cooling diode-pumped YAGs 16-Feb-20 12:25 PM ahh 16-Feb-20 12:25 PM cool, thanks for the info 16-Feb-20 12:25 PM i got a double claw ISO clamp instead of single claw clamp for something that i should have gotten single -- i'm guessing that's still fine if i use a shorter bolt? 16-Feb-20 02:54 PM this is weird, I'm giving 24V to BPG400 but not seeing anything on the analog output signal 16-Feb-20 05:30 PM Anyone know a good replacement/equivalent or better-than high voltage, power op amp than this? https://www.digikey.com/product-detail/en/apex-microtechnology-inc/PA84/598-1324-ND/1761948 16-Feb-20 05:30 PM $140 each... And the amplifier they're in has 8 of these 16-Feb-20 05:30 PM Lots of other components in the amp too, so a bit hard to start troubleshooting, especially since I lack a schematic or reference values, etc 16-Feb-20 05:30 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20200216_173147-67A14.jpg 16-Feb-20 08:09 PM <__ice9#6039> Converted water cooler running a blend of water, ethylene glycol, and methanol at -18C 16-Feb-20 08:09 PM <__ice9#6039> It can't really maintain that temp for any significant period with a real load, though 17-Feb-20 12:48 PM ahh 17-Feb-20 01:39 PM how would that compare to using the same blend inside a 1.1 cubic foot freezer? 79W input power 17-Feb-20 01:40 PM Compressor freezers are usually 100%+ efficient 17-Feb-20 01:40 PM so just assume you'll pull 79W of heat out of whatever you're chilling 17-Feb-20 01:45 PM k 17-Feb-20 03:15 PM asked in #radiation because they are for detector projects but does anyone know a source for decent quality but cheap MHV connectors? looks like the options on aliexpress are a lot more expensive than ebay but almost all the ebay sellers are away until March 1st 17-Feb-20 03:15 PM worried that they are "away" and this is actually coronavirus quarantine related given that they said previously they would be away until today 17-Feb-20 04:19 PM university e-waste 17-Feb-20 04:30 PM University e-waste is like a christmas tree, but you don't know which day is christmas. 17-Feb-20 04:34 PM @LRM I ordered stuff during the chinese new year and received it 17-Feb-20 04:35 PM university ewaste is not really an option as much as i wish it was 17-Feb-20 04:35 PM Which i think was during the beginning of the quarantine 17-Feb-20 04:37 PM well there are 3 sellers with them for cheap on eBay (probably the same seller's 3 accounts) and all say they are away until March 1st...only get their autoreply too saying "Message from lm4871n: 1, Our Spring Festival Holiday is from Jan.17 to Mar.1.2020 2, The message won t be replied by our customer service until Mar.1. " 17-Feb-20 04:37 PM first it said they would be back the 14th...then 17th...and now until march 1st 17-Feb-20 07:32 PM <__ice9#6039> @LRM I just bought mine on eBay 17-Feb-20 07:32 PM <__ice9#6039> They are useful for ultrasonic devices also 17-Feb-20 08:00 PM do you have a link to the auction? i was hoping to spend around $2-3each 17-Feb-20 08:59 PM <__ice9#6039> I just bought whichever were cheapest. It was a while ago. 17-Feb-20 08:59 PM <__ice9#6039> That sounds about right though 17-Feb-20 10:11 PM guess I have to suck it up and buy the more expensive options or wait out the coronavirus outbreak (yikes). 17-Feb-20 10:11 PM "Dear, Due to the large-scale outbreak of Wuhan virus, 2019 ncov, China, the customs and logistics companies have entered the state of vacation, we are unable to deliver goods in time. At present, the return to work time in Wuhan is on Mar 1st. We apologize for the inconvenience caused by the virus, and hope you can understand. If you need them,you can order them directly,we will ship the to you ASAP when we return to work. sorry for the inconvenience! best wishes" 17-Feb-20 10:11 PM (odd because they say they are in Shenzhen and nowhere near Wuhan but whatever) 17-Feb-20 10:22 PM From the 10th, to the 20th, to the 27th, to mar 1st 17-Feb-20 10:45 PM my SHV-20kV connectors were $200 each 17-Feb-20 11:40 PM @idmb must be nice to spend other people's money 18-Feb-20 01:09 AM @LRM wow, well, so much for chinese goods 18-Feb-20 12:06 PM Anyone familar with this style of trap? https://www.ebay.com/itm/Vacuum-Generators-Inline-Heated-230v-sorption-Trap/292466466617 18-Feb-20 12:06 PM zeolite or other absorber inside a tub 18-Feb-20 12:06 PM the heater is for when it's dirty 18-Feb-20 12:06 PM I was looking to get another trap or two... and I would like one with a heater like this so I don't have to bake out the sieve material seperatly... 18-Feb-20 12:06 PM Right... but... its welded shut... 18-Feb-20 12:06 PM as far as I can tell the only way in and out is that little cap on the top... 18-Feb-20 12:06 PM can you replace the material inside without cutting it open? 18-Feb-20 12:07 PM not sure 18-Feb-20 12:07 PM I am just worried about it being... a mess 18-Feb-20 12:07 PM actually I'm also not sure if that isn't an ln2 trap 18-Feb-20 12:07 PM (also sorption) 18-Feb-20 12:07 PM if I can empty the material and ultrasonicate it I could probably clean it OK but yea 18-Feb-20 12:07 PM hrm ok 18-Feb-20 12:07 PM that cap is probably the fill port 18-Feb-20 12:09 PM I don't think it would be an LN2 trap with a heater? 18-Feb-20 12:09 PM oh I guess for bake out 18-Feb-20 12:09 PM yea hrm 18-Feb-20 12:09 PM interesting, wouldn't want to cap LN2 though 18-Feb-20 12:09 PM nice little hand grenade 18-Feb-20 12:09 PM lol 18-Feb-20 12:09 PM but yea I currently have an FL20K but most of my pumps are kf16 and I'd rather not dedicate two kf16-25 adapters to using it lol 18-Feb-20 12:09 PM Ah this helps 18-Feb-20 12:09 PM https://www.ebay.com/itm/Huntington-Mechanical-Laboratory-FT-203-Vacuum-Molecular-Sieve-Foreline-Trap/124081867689 18-Feb-20 12:09 PM yea its totally just zeolite through that little cap heh 18-Feb-20 12:09 PM cool 18-Feb-20 12:09 PM totally throwing an offer his way for that trap 18-Feb-20 01:26 PM i would say to make sure nothing clicks after you get it given the location it is coming from 18-Feb-20 04:24 PM huh, zeolite trap on CF, neat 18-Feb-20 04:24 PM i have an FL20K that's overdue for cookin'.. i put zeolite 13X like a doofus in it though and it has a way high bake temp, unlike alumina, so i might have to take it out and throw it in the not-for-food toaster oven instead of an in-situ bake 18-Feb-20 04:27 PM yeaaa I think I got 13X.... and I thought I noticed the really high and long bake time... 18-Feb-20 04:28 PM works great when it's nice and fresh tho 18-Feb-20 04:28 PM it'll pull my foreline down lower than my pump can go 18-Feb-20 04:28 PM heh nice 18-Feb-20 09:38 PM Yeah that trap is pretty common 18-Feb-20 09:38 PM Well type of trap 18-Feb-20 09:38 PM The top is indeed the fill port 18-Feb-20 09:38 PM You really shouldn't need to clean the inside out on a regular basis so it shouldn't be that big of a problem 18-Feb-20 11:25 PM That's a rough line trap? They use CF on rough lines? 19-Feb-20 02:00 AM I have some CF roughing line stuff 19-Feb-20 03:24 AM <__ice9#6039> @Conmega I built one of these foreline traps. It's just zeolite (usually 13X zeolite) and some PTC or closed-loop control heating elements for bake-out. 19-Feb-20 03:24 AM <__ice9#6039> Not sure about ultrasonicating zeolite for desorption. Usually heating is the more common method. Or pressure reduction, in gas processing applications. 19-Feb-20 03:24 AM <__ice9#6039> I built mine out of KF reducers, a KF spool, a KF tee, and a KF-NPT adaptor that I used to make a pass-through 19-Feb-20 03:24 AM <__ice9#6039> I thought the usual bake-out temperature was about 250C, though. @qualia is it supposed to be higher? It wouldn't be difficult for me to substitute in activated alumina. 19-Feb-20 03:51 AM ultrasonicating is to clean the stainless enclosure NOT the zeolite 19-Feb-20 03:59 AM <__ice9#6039> Lol I see 19-Feb-20 08:01 AM 250C is a lot to subject KF gaskets to 19-Feb-20 08:01 AM that's my concern, mostly 19-Feb-20 08:01 AM if it was CF I'd be less hesitant 19-Feb-20 08:32 AM What's a kf spool? 19-Feb-20 09:09 AM <__ice9#6039> If you put the heater in the center of the tube, the gaskets don't hit 250C 19-Feb-20 09:09 AM <__ice9#6039> A spool is just a straight tube with a flange on each end 19-Feb-20 09:09 AM <__ice9#6039> Named because it looks like a spool 19-Feb-20 09:09 AM <__ice9#6039> The term may be more commonly used with triclamp, idk, but same idea 19-Feb-20 09:33 AM Ooo, interesting, when looking for straight pipe with kf ends, I've just searched 'kf straight'... New keyword! 19-Feb-20 12:16 PM I was planning to build zeolite trap using plastic water filter (for 10" cartridges) with 3/4" threads and 3/4->KF25 adapters... Plastic should be good enough for foreline? 19-Feb-20 12:59 PM eh... I mean sure to a degree?? but you'll end up cutting into your pumping speed... 19-Feb-20 12:59 PM Like... I'd just save up the 60 bucks or so to get a real forline trap 19-Feb-20 01:39 PM vacuum sealing plastic threads sounds like an exercise in frustration 19-Feb-20 01:39 PM and a leaky sorbent-loaded foreline is just going to saturate your sorbent and render it .. less than useful, in a pretty short amount of time 19-Feb-20 01:39 PM could actually be worse than not having any sorbent at all, bc if it's saturated and at atmosphere or at a very weak vacuum, when you pump it down it's going to sit there and slowly outgas whatever its sucked up in time 19-Feb-20 01:39 PM what's your application, @ZeptoBars ? 19-Feb-20 01:39 PM @__ice9 putting a heater in the center of my trap is an interesting idea.. i have an FL20K though, so i would have to do some kind of funny thing with a KF electrical feedthrough and some heater wire around the metal sorbent cartridge (+ some thermocouples) 19-Feb-20 01:39 PM i have a couple of multipin kf feedthroughs.. could be interesting to try. still raises my hackles a bit to get things that hot around a bunch of viton 19-Feb-20 03:18 PM Passing this along... PSA: For any international shipments, either to or from the United States, be explicit about the description of what you are shipping. Today I learned that US Customs has very recently tightened up and is rejecting a lot of parcels due to insufficient descriptions. Don't just put "Computer Cable" or "Network Card" anymore - it may bounce. 19-Feb-20 05:46 PM <__ice9#6039> Yeah the slow outgassing of accidentally-saturated sorbent is fixed by running a thermal cycle, but the real problem with using plastic is that it won't actually survive that bake-out in the first place. These really need to be made of metal. 19-Feb-20 05:46 PM <__ice9#6039> @qualia I just used PTC elements to avoid needing thermocouple control. If you use a thermocouple, extra feed-throughs will be needed and another possible point of failure is introduced. If 250C is bad for Viton, 750C is much worse. 19-Feb-20 05:51 PM more for monitoring than control, but sensible 19-Feb-20 06:28 PM <__ice9#6039> @Conmega that's interesting. A large proportion of my incoming packages have been deliberately mislabeled, often in absurd ways. Unfortunate to see an end to that. May mean future tariff crackdowns. 19-Feb-20 06:38 PM Maybe 19-Feb-20 06:38 PM Lately the chinese sellers have gotten noticeably better at labeling the parcels with their real contents. 19-Feb-20 06:39 PM Glad to hear it @Conmega. It would be nicer if Amazon actually policed their third party sellers, but this is a good second. I gather someone at CBP redirected some money to their actual mission, rather than building silly walls. 19-Feb-20 06:44 PM Or they can use revenue from fines for funding silly walls. 19-Feb-20 08:28 PM Do 'Ultra-Torr' vacuum connections work by putting a metal hose into the hole that's roughly the same diameter, and then tightening down the screw thing so that the rubber gasket encloses around what you just put in in order to get a sort of KF seal? 19-Feb-20 10:22 PM It’s not sort of kf 19-Feb-20 10:22 PM But yes, look up CF to quick-connect adapters on lesker. They work the same and work well for metal or glass tubes. 20-Feb-20 12:16 AM <__ice9#6039> Huh so that's how you pump down a tube 20-Feb-20 12:16 AM <__ice9#6039> This is very timely 20-Feb-20 06:11 AM so I have an rv3 that I got cheap but it turns out it is pretty messed up (excessive play in the shaft and rotors). not gonna be able to get my money back on it and fixing it not cheap either... so any ideas what to do with it? Motor works fine, but does not pump. 20-Feb-20 08:22 AM @__ice9 apparently the tolerances on these seals are very tight 20-Feb-20 02:43 PM This is one of my favourite books 20-Feb-20 02:43 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-FAB49.jpg 20-Feb-20 02:59 PM Excellent book, lots of glassware forming tips. 20-Feb-20 02:59 PM Lots of tips in general. 20-Feb-20 04:29 PM I've got that one too 20-Feb-20 04:37 PM so we just got a swagelok gap inspection gauge 20-Feb-20 04:37 PM and on every connection I do with it 20-Feb-20 04:37 PM the ferrules wiggle a little 20-Feb-20 04:37 PM why? 20-Feb-20 04:37 PM like the instructions are just keep trying to insert it until you can't 20-Feb-20 04:55 PM what do you mean by the ferrules wiggle a little? 20-Feb-20 04:55 PM i thought on swagelok stuff the ferrules are inside the fitting and get crushed by the nut... 20-Feb-20 04:56 PM when you remove the nut 20-Feb-20 04:56 PM when the fittings are really nice, the back ferrule is crushed against the front one and very rigidly sealed around the tube 20-Feb-20 04:56 PM and even if you take the nut off, you can't twist it around the tube 20-Feb-20 04:56 PM That's not necessary for a nice connection, but all the connections like that are very nice 20-Feb-20 04:58 PM oh you are saying that when you disassemble them after tightening to where the gauge no longer fits the ferrules are still loose? 20-Feb-20 04:59 PM well when I disassemble completely 20-Feb-20 04:59 PM and just look at tube + ferrules 20-Feb-20 04:59 PM no nut or other connector present 20-Feb-20 05:07 PM I've now done 10+ with the tool 20-Feb-20 05:07 PM they all wiggle about the same amount 20-Feb-20 05:10 PM the wiggling is only after disassembly, right? 20-Feb-20 05:10 PM could be that the pipe is getting swaged smaller by the complete tightening of the fitting and you were only getting it most of the way tight before having the gauge as reference 20-Feb-20 05:10 PM never really had that issue in my experience with swagelok stuff but i have only worked with it a handful of times 20-Feb-20 05:15 PM issue as in never had it happen, or never thought about it / noticed it? 20-Feb-20 05:15 PM I thought it mostly happened when you overtightened 20-Feb-20 05:17 PM well i have never assembled/disassembled the same swagelok connection without replacing the tubing/ferrules so it is possible i just never noticed it 20-Feb-20 05:17 PM but the times i have noticed the ferrules being a bit loose on disassembling and replacing something, the fitting was not causing any problems even if the pipe had been swaged smaller by the fitting 20-Feb-20 05:17 PM not sure if you can overtighten a swagelok fitting if you are not damaging the threads/cone...suppose it could be possible 20-Feb-20 05:21 PM pretty sure you can overtighten it such that it flexes the bit of tube that sticks past the ferrule and forces the ferrule out of the socket 20-Feb-20 09:26 PM <__ice9#6039> Are they reusable in the first place? I thought those things were single use. 20-Feb-20 09:26 PM Yeah they are! 20-Feb-20 09:27 PM <__ice9#6039> Huh interesting -- I thought they were like compression fitting ferrules 20-Feb-20 09:27 PM Reusable how? You can’t remove the bits and use them on new pipe. But you can undo and redo each seal many many times 20-Feb-20 09:28 PM <__ice9#6039> Ah I see 20-Feb-20 09:34 PM They sell flexible metal hose for high pressure, FJ and FM series. Very cool and useful 20-Feb-20 09:34 PM Can doo 100/200 bar and it’s all stainless, no plastics. 20-Feb-20 11:10 PM <__ice9#6039> That's an interesting design. I have seen stainless ones lined with PTFE good to about 300 bar as well. 21-Feb-20 06:58 AM Joined the server. 22-Feb-20 04:49 PM i'm working on a sputtering chamber (for ITO) and am modeling the plate to connect TMP to chamber along with inlets for gas/HV/sensors. figuring out how to connect a (purported) steel Swagelok valve (female 1/4 NPT) to aluminum base. will NPT be okay for high vacuum? 22-Feb-20 05:18 PM Seems a bit small diameter 22-Feb-20 05:18 PM Or is that for gas introduction? 22-Feb-20 05:28 PM yeah the valve is to bring in Argon, will use ISO100 between TMP. I also have a spark plug (M14 1.25) that i'll need to attach 22-Feb-20 05:29 PM Well you don't necessarily need high vac for sputtering, it really depends on how much defects you can tolerate 22-Feb-20 05:30 PM i see, i'm guessing i'll want to get into other things as well but this was the first thing that came to mind that would be fun 22-Feb-20 05:30 PM so hoping to understand the best ways to attach things, especially as i work on building more components 22-Feb-20 06:05 PM When in doubt, overbuild. That's my motto 22-Feb-20 06:05 PM Guess how many times I've had coworkers tell me to stop prematurely optimizing my code! 22-Feb-20 06:21 PM haha, just not sure how to overbuild and if the threads would be a problem 22-Feb-20 08:06 PM I think you could use NPT just fine especially using a low outgassing epoxy or similar as a thread sealant. Assuming the nature of the joint is static - ie you won't be stressing it any more than the cycling of pressure 22-Feb-20 08:17 PM ahh 23-Feb-20 12:24 PM https://youtu.be/FBIzCp24Ix0 23-Feb-20 03:35 PM All these questions about whether something is okay for vacuum can get answered with “how much are you doing it and what pumping speed do you have?” 23-Feb-20 03:35 PM You can hit -8 torr with several npt threads easily if you have a nice turbopump 23-Feb-20 05:07 PM pumping speed solves all woes :D 23-Feb-20 05:55 PM I have a 3/4” npt to kf adapter threaded in to my base and I get ~50 mtorr 23-Feb-20 06:26 PM We have four 1/4" NPT connections on a chamber that hits -8 pretty easily when we take away our real gas load. (1300 L/s turbo) 23-Feb-20 06:26 PM You can't bake but properly taped the seals are quite good and the outgassing isn't that bad. 23-Feb-20 09:07 PM When I used to service old pumps oh exhaust stations there were many NPT thread joints that had a bit of Glyptal smeared on them before they were assembled and if the system meter took a hard mechanical shock they actually held up quite well. If somebody smacked a cart into it though they would get pretty leaky. The solution back them was to brush on more Glyptal! 24-Feb-20 05:34 AM Joined the server. 24-Feb-20 06:21 AM Does anyone know where I could find a CF275 and CF133 centering ring? 24-Feb-20 07:31 AM You mean gasket? 24-Feb-20 08:10 AM Do any of you have experience with Pirani gauges? 24-Feb-20 08:10 AM I have an Edwards APG-L. It’s reading high, like 2e-3 torr hooked directly to a turbopump. A nearby Edwards AIM reads 9e-6 torr. 24-Feb-20 08:15 AM they bottom out at some point and don't read any lower 24-Feb-20 08:15 AM 'tho that bottom is usually at ~e-4 24-Feb-20 08:15 AM almost all have a poti on them to set high and low 24-Feb-20 08:15 AM you pump them below e-5 just to be sure and tell it to display zero 24-Feb-20 08:16 AM I know the calibration procedure requires turning a multi-turn trim pot so it outputs 10V at atmosphere, then take it to a high vacuum and adjust a second pot so it reads 2 V. 24-Feb-20 08:16 AM The problem is that I’m turning the low pot and I hit the pot limit before I can drop it below 2.6 V. 24-Feb-20 08:16 AM So something is really wrong. 24-Feb-20 08:18 AM oh 24-Feb-20 08:18 AM maybe it's contaminated inside? 24-Feb-20 08:20 AM I was wondering.... I was considering unsoldering and testing the trim pot to see if there’s any chance it could be broken. But before messing with it, I was wondering if anyone here had suggestions. 24-Feb-20 08:20 AM With Penning gauges, contamination causes them to read lower than the actual pressure. 24-Feb-20 08:20 AM I wasn’t sure what Pirani gauges would do. Is it contamination of the gauge, bad electronics, etc.? 24-Feb-20 08:20 AM The gauge was an eBay buy, no idea if it ever worked. 24-Feb-20 08:35 AM try washing it 24-Feb-20 08:35 AM fill it with ipa / acetone and flush it gently 24-Feb-20 09:10 AM I can give that a try, thanks! 24-Feb-20 09:46 AM @rdpierce involved with pumping station#1 ? 24-Feb-20 09:46 AM Ordering a sample holder kit for my desktop SEM from Ted Pella. I'm wondering if I should order some sort of standard sample to use a a quality/calibration check for my SEM. Any suggestions? 24-Feb-20 09:47 AM @piGuy the cool ones aren't cheap but look fun and seem useful 24-Feb-20 09:48 AM Yeah it looks like they have some ranging from like 50 bucks to thousands. 24-Feb-20 09:53 AM Yes, @nmz787 I’m a member at PS:One, Analytics Lounge, and the UChicago Polsky Exchange Fab Lab. 24-Feb-20 10:40 AM @rdpierce interesting -- I am also in the city 24-Feb-20 10:42 AM Cool! I’d love to meet up with local people. 24-Feb-20 12:59 PM Joined the server. 24-Feb-20 02:09 PM Ordered sample holders for my SEM. Maybe now I'll actually use it! 24-Feb-20 04:42 PM Anyone else often forget their bellows will collapse when they apply vacuum? 24-Feb-20 05:15 PM i forgot to account for that the first time i tried to use my corrugated 2.75" CF hose and it almost dragged my chamber off its supports, at the time 24-Feb-20 05:15 PM scronch 24-Feb-20 05:36 PM But since it goes with area it’s even more hilarious with the larger bellows 24-Feb-20 05:37 PM imagining a comically huge turbopump on isolation bellows just going 'sproing' 24-Feb-20 05:37 PM like those inflatable pillows used for moving furniture, but backwards :D 24-Feb-20 10:14 PM i haven't turned on TMP yet but I have a bellow on the outlet, will that matter? what happens if it's on an inlet? 24-Feb-20 10:26 PM Calculate the force of vacuum sucking 24-Feb-20 10:26 PM In the case of a big turbopump below a chamber with a large bellows between, you need to push the pump down rather than just hold it up. Vacuum is strong. 25-Feb-20 05:05 AM It depends on the thickness and length of the bellows. I often use a long KF 40 bellows between the chamber and an adaptor to my turbo. It's slower than DN 100 ISO-K (restricts pumping speed), but more flexible to reconfigure. It does not collapse much when the backing pump begins running. 25-Feb-20 07:29 AM Joined the server. 25-Feb-20 08:46 AM Welcome fellow underpaid physicist 25-Feb-20 08:46 AM And for bellows: Force = Pressure X Area. Pressure differential is always 1 atm for vacuum, and so doubling diameter quadruples the force. Stiffer bellows provide a stronger springy force to push the two ends apart, but reducing the force by diameter helps much more. Larger flanges can easily have enough force to lift 100s of Kg 25-Feb-20 09:00 AM 13.25" CF can lift 500Kg 25-Feb-20 10:17 AM Of course 25-Feb-20 11:09 AM Joined the server. 25-Feb-20 06:15 PM Uff, was trying to restart my FIB rough pump and the control system wasn't doing it, so I plugged it in directly to the wall and it sounded slow, but i figured it was cold oil due to it being off for a night. Then the pump shut itself off and i smelled a weird smell. 25-Feb-20 06:15 PM Read the manual and it says there's a thermal cutoff that should reset 25-Feb-20 06:15 PM Hopefully i didn't melt any winding insulation 25-Feb-20 06:15 PM Oh, forgot to mention i saw it's set to 220V 25-Feb-20 06:22 PM my leybold d8c is kind of a rough starter, especially when cold -- i need to turn it on for a couple seconds, then off, then back on again 2 or 3 times to get it rolling. if i just leave it on it goes 'whrrrmmm' and browns out everything else on the circuit and/or pops a breaker 25-Feb-20 06:22 PM An i had plugged in 110 25-Feb-20 06:22 PM yea thats not good 25-Feb-20 06:22 PM Mmm, no wonder it sounded sluggish 25-Feb-20 06:22 PM motor will not appreciate that 25-Feb-20 06:24 PM ALSO: pop open the gas ballast; if it's trying to crank against a pocket of pre-foreline vacuum then it's gonna have to work extra hard 25-Feb-20 06:24 PM but yeah uh undervolting that hard sounds like Current Draw City 25-Feb-20 06:24 PM (also, my leybold's comical bootstrap current and subsequent voltage droop was how i learned that new kill-a-watts have a brownout beeper alarm) 25-Feb-20 06:32 PM It lives! 25-Feb-20 06:34 PM yay :D 25-Feb-20 06:36 PM Glad it has a switch to change to 110 inside, for testing 25-Feb-20 06:36 PM Just found the breaker for the rough pump needed reset 25-Feb-20 06:36 PM So hopefully the machine boots all on its own now 25-Feb-20 06:36 PM Whoo! 25-Feb-20 06:36 PM And whew! 25-Feb-20 06:36 PM I ran out of nitrogen last night and the machine powered itself off... I guess it disabled the rough pump completely for some reason... Maybe it thinks restoring gas pressure isn't enough manual intervention 25-Feb-20 06:47 PM At least i was able to keep the IGP running for all but the few times I restarted the entire thing 25-Feb-20 09:33 PM @Mason_Yu let’s move here. What exactly are you wanting to do again? If you’re trying to pump helium and hydrogen? 25-Feb-20 09:33 PM Helium and nitrogen is a primary gas load in a z-pinch experiment I'm working on 25-Feb-20 09:34 PM With what loads? 25-Feb-20 09:34 PM It requires differential pumping, so there is a continuous gas load 25-Feb-20 09:34 PM For a ion drift tube. The electrical load is a plasma focus electrode, which essentially has to be built into part of the chamber 25-Feb-20 09:34 PM I can't afford super expensive ceramic insulators in my set-up, so I can't really electrically insulate the pump completely from the pulse 25-Feb-20 09:36 PM So your chamber walls won’t be grounded?... 25-Feb-20 09:39 PM The chamber is grounded, but with a pulse in the hundred kA range with peak voltages exceeding 20 kV, I can still kill the delicate integrated driver inside the turbo 25-Feb-20 09:39 PM Ok, and what vacuum level? Do you actually need ceramic or would acrylic suffice? 25-Feb-20 09:39 PM I guess many kA makes that problematic 25-Feb-20 09:43 PM In the drift tube I need 10-6. I've also designed a frame with acrylic and plastic mounting the pump to the steel frame, so it won't have a direct low resistance path to ground through the pump and its internals. The power supply for the pump is isolated, and the power going to everything else has either inductive chokes or at the very least EMI filters 25-Feb-20 09:45 PM Could you just have an acrylic ISO coupler between the turbo and the chamber? 25-Feb-20 09:45 PM I don't think so. I need to bake the chamber and the acrylic will just add a constant gas load 25-Feb-20 09:46 PM Why do you need to bake? 25-Feb-20 09:46 PM Really lower than 10^-6 is better in the drift tube. But it should definitely be UHV in the main chamber, meaning I will need to bake the stainless 25-Feb-20 09:47 PM Are you trying to use one pump for a differential pumping system? 25-Feb-20 09:47 PM I said it's a differentially pumped system before 25-Feb-20 09:47 PM Yeah but with one pump?... 25-Feb-20 09:48 PM Two, I have another turbo on the chamber 25-Feb-20 09:48 PM Isn’t that just as susceptible to the pulses? Or does one have an integrated driver and the other doesn’t? 25-Feb-20 09:48 PM Even at 200L/s you’ll hit -8 easily without baking. 25-Feb-20 09:49 PM That turbo is okay. First of all it won't be running once there's fill gas in the chamber, and it will be completely unplugged from its external driver when the pulse happens 25-Feb-20 09:49 PM With acrylic? 25-Feb-20 09:49 PM For 1000L/s turbos acrylic flanges are often used as cheap big viewports 25-Feb-20 09:49 PM Hmm, okay, I will consider that 25-Feb-20 09:51 PM It also can easily tolerate 50C+which should be all you’d get if you only bake an adjacent chamber and can easily have your temp sensor turn off the heaters near that 25-Feb-20 09:52 PM I think perhaps the thermal conduction through the massive stainless flanges will be a bit too much, but I'll see if I can get away with no bake 25-Feb-20 09:52 PM Just overwhelm gas loads with pumping speeds! 25-Feb-20 09:52 PM And be patient 25-Feb-20 09:52 PM If there's one thing I don't lack, it's pumping speed 25-Feb-20 09:53 PM acrylic is "not that bad" 25-Feb-20 09:53 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screen_Shot_2020-02-25_at_9.53.32_PM-52624.png 25-Feb-20 09:53 PM photo from lab with million-dollar+ annual budget 25-Feb-20 09:54 PM Oh neat! Anything holding that down besides vacuum? 25-Feb-20 09:54 PM below the chamber: 2000 L/s turbopump 25-Feb-20 09:54 PM Nope. But that's a huge vacuum force 25-Feb-20 09:54 PM doubles as an overpressure valve 25-Feb-20 09:54 PM top view 25-Feb-20 09:54 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screen_Shot_2020-02-25_at_9.55.29_PM-FC58B.png 25-Feb-20 09:54 PM these chambers typically run ~1E-5 torr because of a massive helium gas load, but when you cut that down we get ~5E-8. 25-Feb-20 09:54 PM I like pfeiffers labels 25-Feb-20 09:54 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screen_Shot_2020-02-25_at_9.57.42_PM-25BFF.png 25-Feb-20 09:54 PM vs 25-Feb-20 09:58 PM That's what you call idiot proof 25-Feb-20 10:00 PM I don't know with acrylic as a spacer how much you'd have to worry about crushing forces cracking it, but in general compression is nice so... 25-Feb-20 10:00 PM you'd also then have to use some funky bolts 25-Feb-20 10:00 PM I have quite a bit of alumina bolts on the chamber already 25-Feb-20 10:00 PM Quite literally, because they break 25-Feb-20 10:01 PM I have only twice had to break out a hacksaw to remove a jammed stainless bolt 25-Feb-20 10:01 PM do you have a schematic of what you've already planned? 25-Feb-20 10:01 PM I don't really know differential pumping for anything other than molecular jets 25-Feb-20 10:04 PM For the vacuum system? No simplified schematic, but I do have full CAD of everything. I'm afraid I can't share the whole thing though 25-Feb-20 10:05 PM block diagrams are lovely in that sense 25-Feb-20 10:06 PM It's really not that complicated... a pin-hole plate is really what it is 25-Feb-20 10:06 PM But why the goal for the pressure gradient in the first place? 25-Feb-20 10:08 PM So I can have a chamber with a fill gas that's suitable for the plasma focus, then extract part of the ion beam from it into a low pressure drift tube for time-of-flight measurements 25-Feb-20 10:08 PM Is there a good simple writeup of that? I assume that's not the novel part 25-Feb-20 10:08 PM I'm looking at z pinch stuff but it's very broad 25-Feb-20 10:09 PM Ah here it is 25-Feb-20 10:09 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-DD342.png 25-Feb-20 10:09 PM So their pin hole is tiny, I want a bigger one. Also my drift tube is longer, so pressure needs to be lower 25-Feb-20 10:10 PM why is there a skimmer and a pinhole?... 25-Feb-20 10:10 PM For differential pumping and collimation of the beam 25-Feb-20 10:11 PM Yeah but both? that far apart? with no pumping in between? 25-Feb-20 10:11 PM What? they have a pump connected through that tee in the drift tube 25-Feb-20 10:11 PM There's also only one pin hole 25-Feb-20 10:12 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screen_Shot_2020-02-25_at_10.12.28_PM-C1E5B.png 25-Feb-20 10:12 PM that's labelled as a skimmer and a pinhole 25-Feb-20 10:12 PM do they just mean the skimmer is the pinhole or for some reason are they doing both as one piece?... 25-Feb-20 10:13 PM I think that's what it mean yeah. You get a better beam collimation that way 25-Feb-20 10:14 PM I don't really see why. That would normally make things worse 25-Feb-20 10:14 PM anyways so the top part forms a plasma then the switch accelerates it then you try to collimate it as it goes through from one chamber to the other? 25-Feb-20 10:15 PM Huh? Skimmers make the beam quality worse? 25-Feb-20 10:16 PM a skimmer with an aperture behind it with nothing pumping the stuff in between 25-Feb-20 10:16 PM https://sites.google.com/site/evenlavievalve/vacuum-skimmers-etc 25-Feb-20 10:16 PM see the later figures 25-Feb-20 10:17 PM Well this is for charged particles moving at very high speeds 25-Feb-20 10:17 PM An aperture behind that will either do nothing or make things worse 25-Feb-20 10:17 PM typically you would have another differential pumping stage in between, and then either a second skimmer or an aperture, or just the skimmer and no aperture behind 25-Feb-20 10:18 PM So there's not really any "flow" for an ion beam, and you can't pump the ion beam neither. All you can do is block what you don't want, and I think that's what they mean by using a skimmer 25-Feb-20 10:18 PM Perhaps it means a very different thing in the world of molecular jets 25-Feb-20 10:19 PM These plasma skimmers look massive, are they meant to just be grounding material ? 25-Feb-20 10:20 PM Well the pinhole/skimmer is not meant to skim a plasma jet here (like in a plasma torch), it's meant to collimate an ion beam with energy up to a few MeVs 25-Feb-20 10:22 PM I don't see any other schematics that look like that 25-Feb-20 10:22 PM there's always differential pumping between subsequent apertures/skimmers 25-Feb-20 10:22 PM How about this 25-Feb-20 10:22 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-21F3E.png 25-Feb-20 10:24 PM so that's just an aperture? no skimmer? 25-Feb-20 10:24 PM Yeah 25-Feb-20 10:24 PM The aperture is meant to just block off most of the high energy ions, a "skimmer" is really just additional material around the aperture to get a well-collimated beam 25-Feb-20 10:25 PM I don't see how that can not be destructive to the beam 25-Feb-20 10:25 PM skimmers are used for atomic/molecular/cluster jets to cut the distribution sharply while diverting the blocked portion away, and minimizing interference on the back 25-Feb-20 10:28 PM Again I think the terminology is perhaps not the best here, the word skimmer means a very different thing in molecular jets vs in high energy ion beam collimation 25-Feb-20 10:28 PM You can't pump an multi-MeV ion beam, all you can do is steer it with fields, or block it off entirely 25-Feb-20 10:30 PM So the skimmer is just a shaped ground? 25-Feb-20 10:30 PM You can think of it like that yes 25-Feb-20 10:30 PM so ~1cm inlet or so if you have a ~150um pinhole behind? 25-Feb-20 10:30 PM I'm also struggling to see how you're going to do this without the same large insulator between the anode and the rest? 25-Feb-20 10:33 PM The inlet diameter doesn't really matter for the ion beam, the thickness of the pinhole plate/cone does 25-Feb-20 10:33 PM Oh yeah I have a beefy quartz insulator 25-Feb-20 10:33 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Fused_Quartz_Inuslator_Machined-ADD09.jpg 25-Feb-20 10:33 PM The main challenge here is mechanical, surprisingly 25-Feb-20 10:33 PM These things chip and shatter easily, hence the thickness there 25-Feb-20 10:35 PM Ok so now my confusion is how with that schematic are you planning to turn the one turbo off before working? 25-Feb-20 10:36 PM There's an isolation valve gating off the turbo on the chamber 25-Feb-20 10:36 PM But then your chamber won't be in a steady state at all? 25-Feb-20 10:36 PM Precision leak valve is the answer there 25-Feb-20 10:36 PM Like the goal is to fill it ~1mbar right? 25-Feb-20 10:37 PM Yep, mass flow controller, precision leak valve, both work 25-Feb-20 10:37 PM Wouldn't this typically be done with the pump on? 25-Feb-20 10:37 PM Which pump? 25-Feb-20 10:37 PM I guess not 1mbar 25-Feb-20 10:37 PM I'm used to using leak valves to hit specific pressures in -6 range 25-Feb-20 10:38 PM The leak valve is nice for introducing a precise but small amount of gas into a mixture. 25-Feb-20 10:38 PM but at ~1mbar other factors are negligible unless you've got a really leaky chamber 25-Feb-20 10:38 PM Yeah leaking a precise amount is not helpful when everything else is drifting lots 25-Feb-20 10:39 PM So that's why it's important to get rid of as much gas load as possible 25-Feb-20 10:39 PM Yeah. Acrylic still won't be an issue though. 25-Feb-20 10:39 PM Purity of the fill gas is of course important too 25-Feb-20 10:39 PM But stuff like poorly done NPT seals will be 25-Feb-20 10:39 PM What sort of timescale will it be from closing the valve to opening it again? 25-Feb-20 10:40 PM The goal is to achieve a steady-state, so as long as you want I guess? 25-Feb-20 10:41 PM ah. 25-Feb-20 10:41 PM Realistically it will be limited by other factors of course, at some point you need to pump it down again 25-Feb-20 10:44 PM sounds like you should just get a small turbo you don't care about 25-Feb-20 10:44 PM Wait, if it's only pumped on for a short time... Can't you just set up valves and use the other turbo? 25-Feb-20 10:46 PM Yeah, in the long term it's possible to run a bellow from the other turbo 25-Feb-20 10:46 PM Since you're not "differentialy pumping" both, but pumping one and having one already pumped? 25-Feb-20 10:46 PM But I already have this thing 25-Feb-20 10:46 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/TPH_040-D6110.jpg 25-Feb-20 10:46 PM That's the small one right? 25-Feb-20 10:46 PM Yeah 25-Feb-20 10:46 PM I still care about it though, I love all my turbos 25-Feb-20 10:48 PM Ok so simplest seems to be to add a valve + bellows between the chambers with a ceramic break, since pumping speed really seems irrelevant 25-Feb-20 10:49 PM The flanges and packaging worked out nice with this small turbo. The ceramic break is expensive. I still want reasonable pumping speed on the chamber and that small turbo will do much better than the big one through two 90 degree bends and long KF40 bellows 25-Feb-20 10:50 PM a new KF40 30kV ceramic break is $330, nothing cheaper used? 25-Feb-20 10:50 PM 60kV $550 25-Feb-20 10:51 PM Drift tube is ISO100 with my own adaptor onto a 8" CF flange with the collimator, and $330 is quite a lot to me, that turbo costed about that much with a controller 25-Feb-20 10:52 PM but used ones must be much cheaper when they come up? 25-Feb-20 10:52 PM the pumping speed may sound terirble but with no gas load it honestly doesn't matter that much 25-Feb-20 10:52 PM like you can throttle down to single digit L/s and it will still beat offgassing down below -6 easily 25-Feb-20 10:52 PM relatively quickly too 25-Feb-20 10:52 PM But you don't even need the ceramic break if you're turning off that second turbo anyways? 25-Feb-20 10:55 PM I'll add that to my eBay saved searches, but I think I'll just insulate the pump mounting, put inductive choke on power supply... etc 25-Feb-20 10:55 PM Yeah the small turbo is safe 25-Feb-20 10:55 PM It will be completely unplugged, no path to ground through it 25-Feb-20 10:57 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screen_Shot_2020-02-25_at_10.57.37_PM-4CE47.png 25-Feb-20 10:57 PM like just do that 25-Feb-20 10:58 PM At some point in the future, when I need the small turbo again I will do it 25-Feb-20 10:58 PM But for now, it means I don't have to use the big turbo if I just want to pump down the chamber 25-Feb-20 10:58 PM Drift tube is not on at the moment 25-Feb-20 11:00 PM Wasn't your original problem "Which pump should I use for the source chamber?" 25-Feb-20 11:01 PM No, it's which pump I should use for the drift tube 25-Feb-20 11:01 PM The cryopump also turned out to be much taller than I expected 25-Feb-20 11:01 PM So packaging is harder 25-Feb-20 11:05 PM Ok so the drift tube turbo is the one you're worried about because it WILL be running when you're doing the experiemnt? 25-Feb-20 11:05 PM Yeah 25-Feb-20 11:07 PM I got that backwards somehow. Ok, acrylic is my suggestion again then. 25-Feb-20 11:07 PM Turbo is CF8 ? 25-Feb-20 11:07 PM ISO200 25-Feb-20 11:07 PM Still dwarfed by the 10" ASA flange though 25-Feb-20 11:12 PM That’s an expensive piece of acrylic stock tbh 25-Feb-20 11:12 PM I have an iso-250k acrylic flange. 1” thick 25-Feb-20 11:12 PM I think the stock would have been ~$100 here? 25-Feb-20 11:16 PM Any way to fix scratches? 25-Feb-20 11:17 PM Fix? 25-Feb-20 11:17 PM I sand and lap stainless or aluminum flanges all the time, but scratches in acrylic are deep 25-Feb-20 11:17 PM I'm bound to accidentally scratch its surface, just preparing for the inevitable if the stock is so expensive 25-Feb-20 11:18 PM If it’s beside the pump inlet it won’t matter 25-Feb-20 11:18 PM Even if it’s not 25-Feb-20 11:18 PM Have you used the turbo much yet? 25-Feb-20 11:20 PM The big one? Not yet 25-Feb-20 11:22 PM How big is the area of the drift tube inside? It’s just an iso100 tube a few 10s of cm long? 25-Feb-20 11:22 PM About 70 cm long, with some detector feedthroughs and ports for gauges 25-Feb-20 11:23 PM My ancient unserviced leybold 1000c brings an 8” cf cross down to -6 before its even done spinning up. 25-Feb-20 11:24 PM Oh I'm not worried about the pumping speed when there's no gas load 25-Feb-20 11:24 PM It's WAY overkill 25-Feb-20 11:24 PM But that’s all that matters for offgassing and scratches 25-Feb-20 11:24 PM You just get virtual leaks and such 25-Feb-20 11:25 PM I have a few virtual leaks in the main chamber at the moment, I suspect it's from a mount for a PIN diode detector 25-Feb-20 11:25 PM But I've been procrastinating to fix it and recently overwhelmed with other work 25-Feb-20 11:26 PM Like -6 is almost “don’t even bother using vented bolts” on blind tapped holes in our system 25-Feb-20 11:26 PM I think at 70cm you do probably want lower than -6 though 25-Feb-20 11:26 PM Your mean free path / background density is somewhat relevant for that kind of flight path 25-Feb-20 11:26 PM Anyways I’m off for now, shocking your chamber is a fun problem to prevent 25-Feb-20 11:29 PM Yeah I should go to bed, supposed to get up early for an exam tomorrow morning 26-Feb-20 01:16 AM @Conmega did you ever test your mks901p controller? 26-Feb-20 01:16 AM I don't feel like hacking another VGA cable... And am considering whether I should just open up kicad and send it off to oshpark 26-Feb-20 01:16 AM But if your thing works and you're willing to throw it on oshpark... ;) 26-Feb-20 02:03 AM If I back my turbo with a drag pump, would I hit higher vac in my chamber? 26-Feb-20 02:05 AM yep 26-Feb-20 07:00 AM Only if you’re compression ratio limited or your forevac is so bad you’re throttling your turbos pumping speed 26-Feb-20 07:48 AM Most turbos have an integral drag pump anyway 26-Feb-20 07:48 AM Backing with another could further improve results, but only incrementally 26-Feb-20 07:51 AM And some turbos aren’t meant for better forevac pressures. The lubricating oil can get pumped away. 26-Feb-20 09:03 AM moin! 26-Feb-20 12:34 PM @nmz787 yea my gauge totally works but the board is almost entirely surface-mount I warn you. This is what the latest revision of the board looked like, but you an ignore the bottom left section of SMD parts, that's for an ADC for a Pffiefer activeline gauge interface I am working on. https://photos.app.goo.gl/RQxEhNZ2d5UXaNLS7 26-Feb-20 12:34 PM I've been using a stencil, board preheater, and hot air to reflow them currently but an old toaster oven would also work. If you don't get a stencil you'l probably want to be sure your iron skills are up to snuff ;) 26-Feb-20 12:37 PM I'm decent with QFP and SSOP 26-Feb-20 12:37 PM It's a good bit larger footprint than I'd like tho to be honest 26-Feb-20 12:37 PM I started working on an arduino mega shield last night... So maybe will see where I'm at with another hour or so 26-Feb-20 12:44 PM Its about as small as I can make it with a screen and 4 buttons 26-Feb-20 12:44 PM https://photos.app.goo.gl/3gcxaxw3SNvUFvvZ8 26-Feb-20 12:44 PM and having the ports accessible 26-Feb-20 12:44 PM you could use a smaller screen but I wanted a graphing functionality for pressure over time 26-Feb-20 12:44 PM I mean its like 70x100mm or so 26-Feb-20 12:44 PM its not massive 26-Feb-20 12:55 PM Hmm, Arduino mega is about 55mm x 110mm 26-Feb-20 12:55 PM But i wouldn't need to make the daughter board that big 26-Feb-20 12:55 PM Was mostly thinking just the rs232 converter and the db15 plug 26-Feb-20 12:55 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20200226_125624-B3045.jpg 26-Feb-20 12:55 PM So maybe 30 mm x 55 mm 26-Feb-20 01:00 PM beefy 26-Feb-20 01:00 PM for most of my gauges I just did DC in + floating BNC out 26-Feb-20 01:02 PM ^ same, am lazy 26-Feb-20 01:02 PM though being able to get at the gas calibrations and relay controllers and other stuff they presumably have would be nice 26-Feb-20 01:04 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/81n6GxCBjeL-1451D.png 26-Feb-20 01:11 PM Yeah, I don't have a db8 on my Arduino :p 26-Feb-20 01:11 PM Also really hate wiring if I can use a PCB 26-Feb-20 01:11 PM But yeah, that db15 to a row of pin headers... 26-Feb-20 01:11 PM With the rs232 converter in between 26-Feb-20 01:11 PM Still a little kludgy 26-Feb-20 01:12 PM I've got a box with a bunch of floating ADCs 26-Feb-20 01:12 PM Wouldn't like taking that to a high paying customer 26-Feb-20 01:12 PM with bnc connectors 26-Feb-20 01:12 PM you mean screw terminals? 26-Feb-20 01:51 PM Nah pins for plugging into the headers on the Arduino 26-Feb-20 02:11 PM Ah 26-Feb-20 02:11 PM Yeah anything important is usually done with the arduinos that you solder to directly 26-Feb-20 02:23 PM Joined the server. 26-Feb-20 04:07 PM I don't think this is as long as a mega so maybe I'm wrong. Either way if size is a problem what do you use for a rouging pump? Lol vacuum hardware is far from small and lightweight. 26-Feb-20 04:11 PM space can be constrained around forelines 26-Feb-20 04:30 PM but you run a 5ft DE15 cable to the gauge? 26-Feb-20 04:30 PM Then your gauge readout is anywhere 26-Feb-20 04:30 PM my gauge controller doesn't just plug off the side of the thing 26-Feb-20 04:40 PM likewise 26-Feb-20 04:40 PM though the mks 500 gauges are nice that way 26-Feb-20 04:58 PM Is there any reason I can't just use hose clamps to connect something to the shaft between first and second stage on my cold head? I'll add a little thermal conductivity... but eh? 26-Feb-20 04:58 PM I need to attach a filter like this: 26-Feb-20 04:58 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/SS-8F-60-74522.png 26-Feb-20 04:58 PM to 1/8" stainless line that goes from a feedthrough near the cold head base flange to a nozzle on the tip 26-Feb-20 04:58 PM and sure I could have something made that held it nicely by the first stage flange 26-Feb-20 04:58 PM But... hose clamp.. ? 26-Feb-20 05:15 PM it would appear I have another option 26-Feb-20 05:15 PM "don't attach it at all" 26-Feb-20 05:15 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-6E455.png 26-Feb-20 05:25 PM oh, i see, yeah 26-Feb-20 05:25 PM just let it hang out 26-Feb-20 05:25 PM as long as its secure on the ends and the extra mass doesn't make stuff misbehave (vibration issues?) 26-Feb-20 05:31 PM the tubing is stiff enough it should be fine 26-Feb-20 05:31 PM there's a cryoshield that goes around from the first stage around the first stage 26-Feb-20 05:31 PM but it should be fine if it's wrapped tight 27-Feb-20 10:56 AM How difficult is it to rebuild an Edwards EXT70? 27-Feb-20 10:56 AM We thought we had a working spare. 27-Feb-20 10:56 AM And we found out the “spare” was actually seized up. 27-Feb-20 10:56 AM I get the feeling this may be a function of how badly things failed inside it. 27-Feb-20 11:00 AM You should be able to access the bottom bearing oil reservoir easily by just taking off the bottom cover 27-Feb-20 11:00 AM And if that bearing is bad you can also pull it without special tools I believe 27-Feb-20 11:00 AM The top magnetic bearing can be a bit more tricky, but if that is bad then it's probably not worth making your own repairs 27-Feb-20 12:25 PM ted pella getting too much of my paycheck 27-Feb-20 12:43 PM lol 27-Feb-20 07:36 PM tightly wrapping my 1/8" SS tube around my cold head went swimmingly 28-Feb-20 01:11 AM hi 28-Feb-20 01:42 AM what's your 'lab automation/ data aquisition/presentation approach'? simply using jupyter or something like that? 28-Feb-20 01:42 AM not sure if that's an on or off topic question 28-Feb-20 04:45 AM Python scripting and gnuplot for some things 28-Feb-20 06:27 AM yeah 28-Feb-20 07:17 AM We’re a “we don’t pay for it ourselves so matlab and Labview” lab 28-Feb-20 07:17 AM Neighbours are all Linux & python 28-Feb-20 09:39 AM Joined the server. 28-Feb-20 09:51 AM no labview here 28-Feb-20 09:55 AM There’s some interesting things happening in the EPICS community around Bluesky 28-Feb-20 09:55 AM It’s all FOSS. 28-Feb-20 09:57 AM https://blueskyproject.io 28-Feb-20 09:57 AM that? 28-Feb-20 09:57 AM noice 28-Feb-20 09:59 AM Yes. 28-Feb-20 10:18 AM We're a labview/origin lab. Origin primarily because my boss has been using it since his PhD and would lose a ton of data if we switched at this point. 28-Feb-20 10:19 AM the elders in our group are origin but nobody else has it installed 28-Feb-20 10:28 AM I don't think any of us like origin, but we use it because it makes it a lot easier on my boss for grants/presentations 28-Feb-20 10:43 AM the two key questions are do you have a diffusion pump on your source chamber and is your cold head vertical or horizontal? 28-Feb-20 01:00 PM Matlab is pretty gross in my opinion 28-Feb-20 01:28 PM in lots and lots and lots of ways yeah 28-Feb-20 01:53 PM The signal processing aspects of it are nice in that they make complex stuff easy to use, but for general purpose, meh, lots of nicer choices 28-Feb-20 01:53 PM Jupyter notebooks being one 28-Feb-20 01:53 PM But yeah, if you need DSP stuff or physics stuff, i understand the utility 28-Feb-20 02:00 PM <𝓕ermion#6024> Joined the server. 28-Feb-20 02:01 PM Joined the server. 28-Feb-20 02:10 PM <𝓕ermion#6024> suppose your building is fitted with about 50 feet of 8 inch vacuum pumping line (yay) 28-Feb-20 02:10 PM <𝓕ermion#6024> but it's been contaminated with oil because it was pumped on by an oil pump with no filtering. (booo) 28-Feb-20 02:10 PM <𝓕ermion#6024> and now I wish to use a nice scroll pump and recover the gas that's been pulled from the line. 28-Feb-20 02:10 PM <𝓕ermion#6024> and I don't want to mess up the scroll pump, or have oil in the stuff coming from the scroll pump 28-Feb-20 02:10 PM <𝓕ermion#6024> what do? 28-Feb-20 02:10 PM <𝓕ermion#6024> a. forget the lines. Lost cause 28-Feb-20 02:10 PM <𝓕ermion#6024> b. run a zeolite trap on the input to the scroll pump 28-Feb-20 02:10 PM <𝓕ermion#6024> c. ??? 28-Feb-20 02:41 PM Joined the server. 28-Feb-20 02:46 PM what's the gas that you're trying to recover? can you somehow get a cold trap of some kind inline to drop the vapor pressure of the backstreamed oil to a point of negligibility, but not cold enough to freeze out the gas? 28-Feb-20 02:46 PM a zeolite might also 'sorb up your gas, too, depending 28-Feb-20 02:46 PM a. seems like the safest option and depending on your cleanliness constraints might be the only option, unless a scroll pump rebuild is in the cards. your pumping line will eventually need cleaning, too, ofc 28-Feb-20 02:49 PM <𝓕ermion#6024> just helium 28-Feb-20 02:49 PM <𝓕ermion#6024> good luck sorbing that up at room temperature, heh 28-Feb-20 02:49 PM <𝓕ermion#6024> and a cold trap would be oooookaaayyy.... but if ever it runs empty accidentally, that'll all end up in the pump and then in the recovery unit 28-Feb-20 02:50 PM oh i assumed this was a temporary 'i just need to recover this gas once and then i can tear it all down for cleaning' kinda situation 28-Feb-20 02:51 PM <𝓕ermion#6024> no, no. 28-Feb-20 02:52 PM do you have any kind of trap upstream of this vacuum pumping line? do you know if its backstreamed further than that? 28-Feb-20 02:52 PM i know that Circumstances may render this impossible, but that sounds like a 'bring it to atmosphere, clean it, and never let oil near it again' kind of situation 28-Feb-20 02:52 PM esp. if this is a UHV system 28-Feb-20 02:52 PM also marijuanafermion is an incredible handle jsyk lmao 28-Feb-20 02:52 PM also welcome all y'all new folks! 28-Feb-20 02:58 PM <𝓕ermion#6024> I wouldn't even know how to clean it is the problem 28-Feb-20 02:58 PM <𝓕ermion#6024> it's 50 feet of 8 inch copper pipe that snakes all over the building 28-Feb-20 03:02 PM fermilab once used a ferret to clean their accelerator lines. so here's what you do -- get a very fluffy raccoon, fit it with an appropriate self-contained breathing apparatus, dip it in acetone and send it on through.. 28-Feb-20 03:02 PM my first thought was 'flush it through with recirculating acetone a few times over, then anhydrous isopropyl, then DI water; mass-spec sample the output from each run if you can' 28-Feb-20 03:02 PM there's probably a better way to do this 28-Feb-20 03:03 PM <𝓕ermion#6024> that's what I keep thinking 28-Feb-20 03:03 PM <𝓕ermion#6024> tbh I keep thinking there's like a... guy with a van that can come out 28-Feb-20 03:04 PM i know this is okay for stainless steel BUT i am less sure about copper 28-Feb-20 03:04 PM like a chimney sweep 28-Feb-20 03:04 PM <𝓕ermion#6024> yeah. 28-Feb-20 03:04 PM <𝓕ermion#6024> exactly. 28-Feb-20 03:04 PM <𝓕ermion#6024> "Earl's vacuum line cleaning." 28-Feb-20 03:04 PM <𝓕ermion#6024> and they flush acetone through everything by hooking up to and blanking the various ports. 28-Feb-20 03:10 PM i'd wager one of the big vacuum hardware manufacturers might be willing to send out someone to address this Situation for $$$$$ 28-Feb-20 03:10 PM or at least consult on how to un-destroy things 28-Feb-20 03:11 PM <𝓕ermion#6024> lol an ideal vacuum rep said they're trashed. 28-Feb-20 03:11 PM rip 28-Feb-20 03:11 PM how are the pipes assembled? 28-Feb-20 03:13 PM <𝓕ermion#6024> they're soldered 28-Feb-20 03:14 PM hmm that is what i was assuming but hoping not. disassembly, cleaning, and reassembly might run close to just replacing the pipes with something new 28-Feb-20 03:14 PM lot of labor involved there 28-Feb-20 03:14 PM ^ 28-Feb-20 03:14 PM if it was all bolted together you could do it section by section fairly easily when you had downtime on other things 28-Feb-20 03:15 PM also where in the world do you get 8" vacuum-rated-thickness copper pipe 28-Feb-20 03:15 PM you'll probably recoup significant costs just from reselling that 28-Feb-20 03:16 PM yeah the scrap value is almost definitely going to pay for replacing with stainless if you get a deal on the installation 28-Feb-20 03:17 PM does it need to be 8"? is it backing dozens of turbopumps or something? 28-Feb-20 03:18 PM i wonder what wall thickness it is 28-Feb-20 03:18 PM thin wall at that size would be 0.17" according to the charts i am seeing 28-Feb-20 03:18 PM 0.271" for thick wall 28-Feb-20 03:18 PM hell of a lot of copper either way 28-Feb-20 03:19 PM c h o n k 28-Feb-20 03:20 PM <𝓕ermion#6024> it's the 1 K pot line 28-Feb-20 03:22 PM oh goodness 28-Feb-20 03:22 PM <𝓕ermion#6024> lol what? 28-Feb-20 03:24 PM you certainly have an interesting and expensive problem on your hands 28-Feb-20 03:24 PM <𝓕ermion#6024> that's what I like to hear 28-Feb-20 03:26 PM is this 1k-pot system backing another kind of refrigeration system? i'm not super familiar with cryogenic tech 28-Feb-20 03:26 PM <𝓕ermion#6024> yeah it's a 3he system 28-Feb-20 03:26 PM how much downtime can the involved systems tolerate? 28-Feb-20 03:27 PM <𝓕ermion#6024> it's been down for years 28-Feb-20 03:27 PM OH 28-Feb-20 03:27 PM well in that case 28-Feb-20 03:27 PM do y'all have a helium mass spec to do leak testing? 28-Feb-20 03:28 PM <𝓕ermion#6024> yep 28-Feb-20 03:30 PM find out what wall thickness you are dealing with on the copper and work out the scrap value 28-Feb-20 03:30 PM go from there 28-Feb-20 03:32 PM my vote for a salvage-not-scrap option would be to start desoldering manageably short pieces of the pipe starting at the end nearest the pump, acetone/isopropyl clean the shortest section you can, put it on the scroll pump with the leak tester and/or an RGA going 28-Feb-20 03:32 PM mind the solder you use to reassemble it; blank it off, test it, proceed slowly and add on lengths successively as you clean more parts out 28-Feb-20 03:33 PM to be fair...i think the resoldering 8" pipe thing might be a little bit much for someone who does not do hvac/plumbing work regularly to take on 28-Feb-20 03:34 PM however you may discover as soon as you pop open the copper pipe that it's all corroded terribly 28-Feb-20 03:34 PM 'cos with oil backstreaming could also come water backstreaming 28-Feb-20 03:34 PM not that it is not doable but copper sinks tons of heat and doing that indoors safely on that scale is not something i would want to try 28-Feb-20 03:34 PM <𝓕ermion#6024> also, I'm not sure how much oil is in there 28-Feb-20 03:34 PM <𝓕ermion#6024> I can just vaguely smell it 28-Feb-20 03:35 PM limited personal experience has led me to the unpleasant realization that sometimes even just a vague smell could mean 'your floor is about to be saturated as soon as that clamp comes off' 28-Feb-20 03:35 PM <𝓕ermion#6024> sounds right. 28-Feb-20 03:37 PM @LRM yeah that's pretty fair actually, dunno who put this system together originally but that's not a trivial plumbing job 28-Feb-20 03:37 PM are you sure it's an oil smell and not a copper smell? 28-Feb-20 03:38 PM <𝓕ermion#6024> I'm not 28-Feb-20 03:38 PM <𝓕ermion#6024> maybe I should just try to pump the thing down. 28-Feb-20 03:38 PM i have a mental image of someone using one of those big blowtorches used for clearing brush/weeds to preheat the joints heh 28-Feb-20 03:38 PM can you swab inside the pipe? 28-Feb-20 03:38 PM <𝓕ermion#6024> it's like 50 feet and has a bunch of joints 28-Feb-20 03:38 PM <𝓕ermion#6024> angles 28-Feb-20 03:38 PM <𝓕ermion#6024> tees 28-Feb-20 03:38 PM if you have an oil pump with a zeolite trap to avoid goofing up your nice scroll pump, could try with that 28-Feb-20 03:39 PM do not mean all of it, just that would be a quick test for oil/no oil in the areas you can reach 28-Feb-20 03:39 PM your base pressure will tell you a lot 28-Feb-20 03:39 PM <𝓕ermion#6024> apparently it all once lead to an enormous pump in the basement that used a 50 gallon oil sump 28-Feb-20 03:39 PM <𝓕ermion#6024> yeah. 28-Feb-20 03:39 PM <𝓕ermion#6024> all good ideas... 28-Feb-20 03:39 PM have fun figuring out the best order of operations 28-Feb-20 03:39 PM <𝓕ermion#6024> I have a contaminated turbo cart 28-Feb-20 03:39 PM <𝓕ermion#6024> might just try that. 28-Feb-20 03:40 PM curious about what in the world kind of vacuum pump would have a 50gal oil sump 28-Feb-20 03:40 PM like an industrial process pump or something? 28-Feb-20 03:42 PM <𝓕ermion#6024> yeah 28-Feb-20 03:42 PM <𝓕ermion#6024> from like... the 80s 28-Feb-20 03:42 PM <𝓕ermion#6024> it's gone now 28-Feb-20 03:43 PM this sounds more like 50s-70s vacuum gear from what i have heard/read than 80s 28-Feb-20 03:43 PM copper is pretty common in stuff from that time period 28-Feb-20 03:44 PM this might be a good opportunity to do some overall reconsidering of your vacuum system as a whole 28-Feb-20 03:44 PM <𝓕ermion#6024> I will likely stick the new pump in a noise insulated cabinet next to the fridge 28-Feb-20 03:44 PM <𝓕ermion#6024> and then just go to a smaller diameter line 28-Feb-20 03:44 PM <𝓕ermion#6024> and then scrap the copper 28-Feb-20 03:46 PM entirely possible you could get away with significantly cheaper KF50 lines or somesuch 28-Feb-20 03:46 PM <𝓕ermion#6024> or potentially put a platform in the basement and then just run bellows down a few feet 28-Feb-20 03:46 PM lathe your own fittings and weld it all together 28-Feb-20 03:46 PM or somesuch 28-Feb-20 03:46 PM the conductance calculations to figure out what's needed by whatever you're backing aren't too complicated to get a ballpark idea, and vacuum sensors are cheap enough to sprinkle all over the place to be certain 28-Feb-20 03:47 PM honestly...do the math on how much copper you have once you find out how thick it is...could probably pay for close to or the same size line especially if you do not need to run 50' 28-Feb-20 03:47 PM ^ 28-Feb-20 03:47 PM <𝓕ermion#6024> tbh we're trying to figure out how to spend the money we have 28-Feb-20 03:47 PM <𝓕ermion#6024> but selling the copper down the line isn't a bad idea. 28-Feb-20 03:47 PM <𝓕ermion#6024> heh down the line. 28-Feb-20 03:48 PM when in operation, is this copper line cold? or do cold things live inside it/get backed by it? 28-Feb-20 03:48 PM <𝓕ermion#6024> no it doesn't get that cold 28-Feb-20 03:48 PM <𝓕ermion#6024> the first few feet of it are cold and then the gas thermalizes to the walls 28-Feb-20 03:48 PM <𝓕ermion#6024> oh you're wondering if the lines are cold enough that the oil isn't a concern 28-Feb-20 03:48 PM <𝓕ermion#6024> lol... 28-Feb-20 03:48 PM <𝓕ermion#6024> I mean I'm now wondering if the 1 K pot has oil in it. 28-Feb-20 03:50 PM that is one reason that soldered copper might be the material of choice.. something like standard KF or ISO flanges may not like being chilled down, and thermal contraction could be a big deal too. not sure if there are, like, indium gasket options for that 28-Feb-20 03:50 PM yeah this whole sitch sounds comprehensive-rebuild-worthy 28-Feb-20 03:50 PM ️ 28-Feb-20 03:54 PM Joined the server. 28-Feb-20 04:03 PM @idmb Diffusion pump on source, vertical cold head. Every chamber has differential pumping. The general set up is: source chamber is backed by a giant ass diffusion pump (it's nearly as tall as I am), pick up cell chamber is backed by a large but much more reasonable diffusion pump, the pick up cell lines are backed by tiny diffusion pumps, and the laser interaction/stark/zeeman effect/mass spec chamber is backed by a turbo pump. 28-Feb-20 04:03 PM For the new cation instrument anyway. The old radical instrument has the mass spec in its own chamber, but the new instrument is more what we would build if we could build that one again. 28-Feb-20 04:03 PM The high vacuum pumps all being roughed by rotary vanes with the exception of the source chamber which is rotary vane+roots blower 28-Feb-20 04:14 PM Cool! 28-Feb-20 04:14 PM I mostly just know Vilesov/Stienkemeyer/Stapelfeldt/jaeger setups 28-Feb-20 04:14 PM I like Jaegers 28-Feb-20 04:14 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-83FBB.png 28-Feb-20 04:14 PM All the femto groups I know have done longitudinal cold heads with turbos, and most of the chem groups have done vertical with diffusion pumps 28-Feb-20 04:18 PM Huh, now that you mention it, that also jives with what I've seen 28-Feb-20 04:18 PM Weird 28-Feb-20 04:18 PM Our system isn't much to look at tbh. Mainly just a lot of stainless 28-Feb-20 04:18 PM And I guess the two optical tables full of crap, but they're not done yet 28-Feb-20 04:32 PM There are also seemingly three CW nozzle types 28-Feb-20 04:32 PM all the SEM apertures of course 28-Feb-20 04:33 PM <𝓕ermion#6024> all these beautiful high vacuum setups... So far outside of my wheelhouse 28-Feb-20 04:33 PM <𝓕ermion#6024> though there is an MBE next door 28-Feb-20 04:33 PM <𝓕ermion#6024> that thing is crazy 28-Feb-20 04:33 PM the people with "free" machine shops make easy to make ones with disposable copper bodies, those of us that have to pay by the hour make it so only the aperture gets replaced 28-Feb-20 04:36 PM The old instrument has the ancient Roger E Miller one that you honestly probably can't even get made if you wanted to. The new one has the Scoles style which is honestly vastly superior 28-Feb-20 04:37 PM Which would you call this? 28-Feb-20 04:37 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-D63AB.png 28-Feb-20 04:38 PM I think that's the Scoles style 28-Feb-20 04:38 PM Actually not positive 28-Feb-20 04:39 PM It's my favourite style 28-Feb-20 04:39 PM you can replace the aperture without removing much at all 28-Feb-20 04:41 PM That's Scoles then yeah 28-Feb-20 04:41 PM Or it could be the third you were talking about 28-Feb-20 04:41 PM the miller ones are the ones with the weird flexible stuff in between right? 28-Feb-20 04:41 PM and right angle? 28-Feb-20 04:41 PM lemme open up solidworks and I'll show you Stienkemeyer 28-Feb-20 04:41 PM it's by far the simplest 28-Feb-20 04:41 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-60E21.png 28-Feb-20 04:41 PM Just a block with a hole through it, brass swagelok soldered onto copper on the back, tapped holes on sides and bottom for mounting/heater/temp sensor, and then just press the platinum aperture into the copper on the front ("roll it in with a weird doohickey") 28-Feb-20 05:28 PM any suggestions on a cold trap design? i'd like to freeze dry some food and should be able to TIG this weekend. I saw Ben Krasnow's but seems like there may be other designs that would reduce the water collection issue he had 28-Feb-20 05:55 PM <𝓕ermion#6024> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-BA3AB.jpg 28-Feb-20 05:55 PM <𝓕ermion#6024> not sure if it's a good design or not, and not too sure what's going on inside that section of copper pipe 28-Feb-20 05:55 PM <𝓕ermion#6024> but I did recently throw this away! and I think it's a cold trap. 28-Feb-20 05:55 PM <𝓕ermion#6024> so basically... you're welcome. 28-Feb-20 05:55 PM <𝓕ermion#6024> oh yeah... does anyone know of a source for KF nipples that have a mounting plate with bolt holes in them? 28-Feb-20 05:55 PM <𝓕ermion#6024> for say mounting a kf nipple to a room-to-room feedthrough 28-Feb-20 06:57 PM Not sure what you mean 28-Feb-20 06:57 PM Lesker have bulkhead kf clamps 28-Feb-20 06:59 PM C-clamps? 28-Feb-20 06:59 PM https://shop.edwardsvacuum.com/fittings/NW/510/516/default.aspx 28-Feb-20 07:08 PM <𝓕ermion#6024> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-888B8.png 28-Feb-20 07:08 PM <𝓕ermion#6024> I want dis 28-Feb-20 07:47 PM Yeah, that's the Miller one. I have a picture somewhere that I'll put up in a bit. Though honestly, the weird part about the Miller nozzle is internal. They do some weird metal casting thing that AFAIK only the machinist at UNC who did it at the time really knows how to do. You could probably recreate a facsimile if you wanted to, but what's the point? It's pretty inferior to the alternatives. Was just something his grad students happened to think of back when people didn't make this kind of stuff. Also, for what it's worth, I'm not sure if Scoles actually came up with that more modular design. I really wanted to say it was Toennies, but I also could have sworn it was designed at Princeton which would be Scoles, so I dunno. 28-Feb-20 07:47 PM Also, out of curiosity, do you also do nanodroplet stuff idmp, or do you just happen to be in a related field that mingles with us a bit? 28-Feb-20 07:47 PM I don't think those exist honestly Mari. I had to have our machine shop make a vacuum friendly lens holder that was basically that design 28-Feb-20 07:47 PM The Miller nozzle. Not a great pic, but best I got 28-Feb-20 07:47 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20191107_105428-DD423.jpg 28-Feb-20 07:51 PM <𝓕ermion#6024> I love using optical tables for random stuff. 28-Feb-20 07:51 PM <𝓕ermion#6024> One of these days I’ll use one as a kitchen table. 28-Feb-20 07:51 PM We have so much more optical table space than counterspace. 28-Feb-20 07:51 PM <𝓕ermion#6024> Yeah that’s how it goes. 28-Feb-20 07:51 PM <𝓕ermion#6024> All our microscopes and our wire bonder are on one. 28-Feb-20 07:51 PM Like, I'm not sure where we would put the vacuum chambers/plumbing stuff, but we definitely have enough optical table space to have a third instrument 28-Feb-20 07:51 PM And my boss has threatened to make a parahydrogen experiment in the past, so who knows 28-Feb-20 07:53 PM <𝓕ermion#6024> People sure like those sumitomo cold heads 28-Feb-20 07:53 PM <𝓕ermion#6024> Everything I’ve used is cryomech. 28-Feb-20 07:55 PM At this point I'm pretty sure my boss sources equipment explicitly so that any and all documentation I may need is a translation rather than written in English first 28-Feb-20 07:55 PM I wish I was kidding 28-Feb-20 07:56 PM <𝓕ermion#6024> Your boss sources equipment? 28-Feb-20 07:56 PM Well, not anymore, but he used to. Like the sumitomo was his decision way back. 28-Feb-20 07:56 PM <𝓕ermion#6024> Ah I see. 28-Feb-20 07:57 PM So I guess I should actually blame the former PhD student 28-Feb-20 07:57 PM Because he's the one that really screws me with that stuff 28-Feb-20 07:57 PM Bought a hamamatsu detector, and the library functions manual was all in broken English 28-Feb-20 07:57 PM Bought faulhaber motors, example code was partially in German 28-Feb-20 07:57 PM All bought by that same student 28-Feb-20 08:01 PM <𝓕ermion#6024> I think those are kinda all the best of their kind. 28-Feb-20 08:01 PM <𝓕ermion#6024> Maxon and faulhaber make great motors. 28-Feb-20 08:01 PM <𝓕ermion#6024> I think Hamamatsu makes the best detectors but could be wrong. 28-Feb-20 08:06 PM The faulhabers are really good tbf 28-Feb-20 08:06 PM But I'd be hesitant to get Hamamatsu 28-Feb-20 08:06 PM I spent...a long time to finally realize that they just sent me a lemon and hoped I wouldn't notice 28-Feb-20 08:06 PM They replaced it, but still, come on. You knew that lot was bad and you just didn't tell me? 28-Feb-20 08:07 PM <𝓕ermion#6024> Oh damn 28-Feb-20 08:07 PM <𝓕ermion#6024> That’s awful. 28-Feb-20 08:08 PM Was a fun first project 28-Feb-20 08:08 PM Though they do have a good reputation 28-Feb-20 08:08 PM But at the same time...yeah 28-Feb-20 08:47 PM everyone uses the sumitomo because the first machine used one 28-Feb-20 08:47 PM Sumitomo RDK408D2 or more poweful like the 415D2 28-Feb-20 08:47 PM I think we're probably at nearly 1000 droplet machines now, so obviously there's a lot of variation 28-Feb-20 08:47 PM But the 408D2 is super prevalent 28-Feb-20 08:47 PM and yeah @Mezmorizor I've been building a droplet machine as a "side project" during my PhD I’m very much more physics than chemistry, though we do do some very unique spectroscopy. 28-Feb-20 08:47 PM Hamamatsu PMTs are all I've seen tbh 28-Feb-20 08:47 PM we only have one 10'x5' optical table being used as a table! the rest are being used for experiments 28-Feb-20 08:47 PM we have some welding tables that are basically really bad optical tables. 28-Feb-20 08:47 PM Use those for mounting stuff to bake 28-Feb-20 09:31 PM The Sumitomo's also seem like they're just really high quality too. Our lab has had about 3 weeks of downtime in a decade where it was ran for at least 8 hours basically ~360 days a year from the older one, and that was a scheduled service thing rather than anything actually going wrong with it. 28-Feb-20 09:31 PM And I'm not sure how I feel about a droplet machine as a "side project", god knows we've spent a lot of man hours on the new one and it's still not up, though I guess the creating droplet beam and doping it with things aspect wasn't too bad. It's everything else... 28-Feb-20 09:31 PM And at this point I have no idea if I'm physics or chemistry tbh. My degree will definitely ultimately say chemistry, yet the theory of the stuff we do is definitely just quantum mechanics, and I have spent most of my time so far in the PhD learning both standard and nonlinear optics... 28-Feb-20 09:31 PM Well, next to standard experimentalist engineering stuff. 28-Feb-20 09:31 PM Also doesn't help that there's a guy here who just straight up does reaction dynamics in physics 28-Feb-20 09:43 PM <𝓕ermion#6024> What’s the best way to permanently backfill something? Do they make KF pinchoffs? 28-Feb-20 10:37 PM think that may depend on the size/nature of what you are trying to seal for the "best way" 29-Feb-20 01:07 AM anyone of you guys tried to build a I2 stabilization for a HeNe? 29-Feb-20 01:16 AM has anyone ever tried to build a HeNe? 29-Feb-20 01:36 AM well that's easy? 29-Feb-20 01:36 AM but tubed are pretty cheap 29-Feb-20 01:36 AM tubes 29-Feb-20 01:36 AM the points are stabelizing them and make them kind of a 'absolute'ish reference 29-Feb-20 01:36 AM right? 29-Feb-20 01:36 AM that would be what I need 29-Feb-20 01:36 AM or is that off topic here and I should move the questions to #lasers_and_optics ? 29-Feb-20 01:36 AM but now some hamsterkaeufe!1 29-Feb-20 01:36 AM I mean it would be totally awesome to build the complete thing from scratch of course 29-Feb-20 08:16 AM It’s a 4th year lab here 29-Feb-20 09:00 AM yeah 29-Feb-20 10:13 AM <𝓕ermion#6024> What’s the right way to blow a gas out to atmosphere in such a way that an absolutely minimal amount of atmosphere goes back in? 29-Feb-20 10:49 AM I mean how minimal are we talking? 29-Feb-20 10:49 AM With 99.9999% helium we vent until it’s close to 2 bar, then vent into a small chamber we pump then vent into then pump then vent into etc 29-Feb-20 11:08 AM And that’s only because impurities will freeze and clog a 5um nozzle 29-Feb-20 11:08 AM When we cool it to ~10k 29-Feb-20 11:14 AM <𝓕ermion#6024> I want to avoid contaminating a helium recovery system so I don’t have to be toooo perfect. 29-Feb-20 11:14 AM <𝓕ermion#6024> But I still don’t wanna get air in there. 29-Feb-20 11:14 AM <𝓕ermion#6024> It’ll plate out on the pulse tube 01-Mar-20 01:31 AM Just for kicks I used my canning jar vacuum sealer on a small half-pint jar, and then threw it in the microwave hoping for plasma... But didn't see anything... I guess either there was too much or not enough gas inside to ionize. 01-Mar-20 10:11 AM Joined the server. 01-Mar-20 03:19 PM Well, the bearing race being loose is not a good sign. 01-Mar-20 03:19 PM Looks like some special wrench is needed to get the bearing cover off. 01-Mar-20 03:53 PM A pair of fine needle nose pliers should do it 01-Mar-20 03:53 PM You can also use the rim of the bearing cup as leverage too 01-Mar-20 03:53 PM But, I think you can also just take off the bearing cup completely 01-Mar-20 03:53 PM There should be threaded holes on its flange that doesn't have any bolts on it. You can use them to push the bearing cup out along with the bearing 01-Mar-20 03:53 PM It is possible that the inner race might be really stuck on the shaft, in which case you will still have to undo the nut 01-Mar-20 03:53 PM The nut or the bearing should not have any retaining compound on it, if it's anything like the EXT255 01-Mar-20 03:53 PM @rdpierce A picture here will help a great deal 01-Mar-20 04:20 PM Ok I got the conical nut on the bottom off and then turned my attention to the top. 01-Mar-20 04:20 PM Got the outer housing off, and the stators and rings. 01-Mar-20 04:21 PM It's easier to remove the retaining nut for the bottom bearing after you remove the entire bearing cup 01-Mar-20 04:21 PM Since the shaft won't be in the way 01-Mar-20 04:21 PM The upper magnetic bearing: I got the first magnet off. 01-Mar-20 04:22 PM So you got the rotor off too then? 01-Mar-20 04:22 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-C5BA6.jpg 01-Mar-20 04:22 PM No, here’s where I’m at: 01-Mar-20 04:22 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-7AB21.jpg 01-Mar-20 04:23 PM A picture of the bottom bearing too? 01-Mar-20 04:24 PM Two magnets are still in there. And the central piece feels very loose (it can slide up and down) but won’t come off. 01-Mar-20 04:24 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-AE3F1.jpg 01-Mar-20 04:25 PM Those are strong magnets, you have to use some leverage 01-Mar-20 04:25 PM Ah, I think you can undo the 4 bolts, and if they are the right size, thread them into the 4 holes that's currently empty so they can push the cup out 01-Mar-20 04:25 PM After that you can worry about the nut retaining the bearing 01-Mar-20 04:25 PM For the top magnetic bearing, you need to get all the magnets out before the top of the shaft can come off 01-Mar-20 04:25 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-46B4F.png 01-Mar-20 04:25 PM That is assuming the safety bearing is still intact 01-Mar-20 04:25 PM So if you have a vise grip or something, you can just try pulling on the top of the shaft. Be careful, since it can jump out with some force after you overcome the magnetic force 01-Mar-20 04:34 PM Ok, I’m confused, are you saying I can get the bottom bearing assembly out now and separate the shaft/rotor/etc. from the pump base? 01-Mar-20 04:35 PM Yes, this part I've highlighted should be the bearing cup 01-Mar-20 04:35 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-A154C.png 01-Mar-20 04:35 PM Assuming your inner race of your bearing is not completely stuck on the shaft, you can undo the bolts and use them to push the whole assembly out 01-Mar-20 04:35 PM Bearing, nut, everything 01-Mar-20 04:35 PM To take the shaft out, you have to disassemble the top magnetic bearing completely too 01-Mar-20 04:35 PM Then you can get to the motor 01-Mar-20 04:37 PM Ok, the four screws are out, the bearing cup can pull back a little, but I’m not seeing what to do. 01-Mar-20 04:37 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-240D9.jpg 01-Mar-20 04:39 PM Does the 4 screws fit into these threaded holes? 01-Mar-20 04:39 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-D0EB7.png 01-Mar-20 04:39 PM And are they blind on the bottom? If so, you can thread in the screws, and by tightening them you are exerting a force pushing the bearing cup out 01-Mar-20 04:39 PM Do this evenly, so you are not bending your shaft with a damaged bottom bearing 01-Mar-20 04:41 PM So I’m pulling the whole cup straight out the back? 01-Mar-20 04:41 PM Yep 01-Mar-20 04:42 PM But will I need to do anything first to the top magnetic bearing? 01-Mar-20 04:42 PM It would be best to take the rest of the magnets out while you have something constraining the shaft on the bottom, but it's not strictly necessary 01-Mar-20 04:46 PM Bingo: the bottom bearing assembly came out and the shaft and rotor are free.... 01-Mar-20 04:47 PM To take out the bearing nut, you can use a pair of pliers leveraging against the rim of the cup. Since it's out now, don't be shy with lubricants 01-Mar-20 04:47 PM If the shaft rotates without any noise or strange friction, it means your safety bearing is still intact, which is excellent news 01-Mar-20 04:47 PM And all things going well the only thing you need to replace is the bottom bearing 01-Mar-20 04:50 PM I think so.... 01-Mar-20 04:50 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-4F7B6.jpg 01-Mar-20 04:50 PM So just jam something in those two holes and unscrew ccw? 01-Mar-20 04:52 PM Yeah 01-Mar-20 04:52 PM That nut with the two round holes is threaded on the OD, so put lubricants, WD-40 in there 01-Mar-20 04:54 PM Ok it is stuck, I’ll look for oil. 01-Mar-20 04:54 PM As for the upper magnetic bearing? 01-Mar-20 04:56 PM They seem fine and I don't think you need to get to the motor. So you have two options: either continue the teardown and try to lift the top of the shaft out (will take a lot of force), or you can just reassemble things on the top, replace the bottom bearing and put the cup back 01-Mar-20 04:56 PM If you are confident that seals inside are clean and motor is still alive, then I'd advice against taking out the rotor 01-Mar-20 04:58 PM I’m not confident about anything relating to this pump. It was seized. 01-Mar-20 04:59 PM Well, then you will need to hold down the pump securely, and try to take out the next two magnetic bearings carefully 01-Mar-20 04:59 PM Can you turn the top of shaft while holding the bottom steady? 01-Mar-20 04:59 PM Nothing on the drawing suggest that this part is threaded, so you should be able to just pull the top of the rotor out. The only thing holding it on right now should be just the magnetic bearings 01-Mar-20 04:59 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-681C7.png 01-Mar-20 05:03 PM The top threaded part spins freely. 01-Mar-20 05:03 PM Does it lift out? 01-Mar-20 05:04 PM It lifts up to a point 01-Mar-20 05:04 PM anyone know what the name of these types of tubes are called that stay in place? 01-Mar-20 05:04 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/0003158_dual-arm-portable-fume-extractor-d-113F4.png 01-Mar-20 05:05 PM So does it feel like a hard stop? Or is there still some springiness when you can't pull it up anymore? 01-Mar-20 05:07 PM Feels like a hard stop 01-Mar-20 05:09 PM Do you have space to put something under the second magnet ring? 01-Mar-20 05:10 PM Maybe? 01-Mar-20 05:11 PM If you can lift them out one by one, that will require much less force. Once you move the rings vertically by a mm or so, they will start repelling and might jump out 01-Mar-20 05:11 PM Ok I got the second magnet out 01-Mar-20 05:12 PM Great! So can you lift the top of the shaft out now? 01-Mar-20 05:13 PM @samy i only know it by the brand name...but maybe that will give you a search term https://www.loc-line.com/products/212-vacuum/212-hose/ & https://www.loc-line.com/products/212-as-vacuum/212-ashose/ 01-Mar-20 05:13 PM No it seems to be catching on the third ring 01-Mar-20 05:14 PM By lifting the top of the shaft, you are lifting the third ring too. The third ring should not be any stronger than the previous two, so you should be able to overcome the magnetic force 01-Mar-20 05:14 PM At least lift it up to where the second ring was 01-Mar-20 05:15 PM Bingo! Got it! 01-Mar-20 05:15 PM So you should see the safety bearing, which should be a loose fit around the shaft 01-Mar-20 05:16 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-700DF.jpg 01-Mar-20 05:16 PM Looks pristine! 01-Mar-20 05:16 PM You should be able to lift the whole rotor shell out now as well 01-Mar-20 05:17 PM Ok so I don’t have to replace the safety bearing. 01-Mar-20 05:18 PM Yeah keep it in with it's snap ring, all of this here should be kept as clean as possible 01-Mar-20 05:18 PM Unlike the bottom bearing 01-Mar-20 05:19 PM Ok, damage report: 01-Mar-20 05:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-61BCC.jpg 01-Mar-20 05:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image1-EF2DC.jpg 01-Mar-20 05:19 PM Oh... 01-Mar-20 05:19 PM Looks like there are some cracks.... 01-Mar-20 05:20 PM Yeah looks like there has been a crash between the magnetic bearings, not sure if you can really find the parts for them 01-Mar-20 05:20 PM How's the inner rings? 01-Mar-20 05:21 PM Inner rings look good 01-Mar-20 05:21 PM As for polarity, should the rings be positions to attract or repel each other? 01-Mar-20 05:23 PM Repel between the inner and outer rings of course, they are bearings 01-Mar-20 05:23 PM Polarity is shown on the drawings, bit hard to make out, but there are N and S marking on each ring 01-Mar-20 05:23 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-69D5E.png 01-Mar-20 05:23 PM You should be able to take out the top metal lip right? The one above the top magnetic bearing ring? 01-Mar-20 05:28 PM On the rotor? How does that come out? 01-Mar-20 05:30 PM On the drawing that lip has a different hatch pattern, indicating its a different part. Also, it must be replaceable or else there'd be no way to put the rings into the rotor in the first place 01-Mar-20 05:30 PM Also it looks like there was some wear on the rotor shaft 01-Mar-20 05:30 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-0A043.jpg 01-Mar-20 05:31 PM That's from when the safety bearing caught the shaft after it crashed into the magnetic bearing 01-Mar-20 05:31 PM So most likely sequence of event is that your bottom bearing died, perhaps because of a lack of lubricant, and the kinetic energy of the rotor could not be held back by the magnetic force alone, there's a crash, two of three rings cracked and the safety bearing saved the third ring and the rotor 01-Mar-20 05:31 PM You should definitely replace the cracked rings if you can, but I think would be really hard to find the right part, and it may be too costly. Might be worth it to call up Edwards to see if they can help 01-Mar-20 05:31 PM But you should be able to find the bottom bearing for cheap 01-Mar-20 05:31 PM Maybe consider the upgrade to dry ceramic bearings, so hopefully this won't happen again 01-Mar-20 05:37 PM Hmmm, someone said they tried and it failed 01-Mar-20 05:38 PM Lubricant in the reservoir does not stay forever and may need to be refilled after long term storage 01-Mar-20 05:38 PM http://www.rtftechnologies.org/general/edwards-ext70turbo.htm 01-Mar-20 05:38 PM Hey, seems you are lucky, $20 each 01-Mar-20 05:39 PM Yeah. It looks like I need, at a minimum, new lube, new felt, new bottom bearing, and new magnets 01-Mar-20 05:40 PM Your rotor doesn't seem nearly as bad as theirs, so you should be good to go there 01-Mar-20 05:40 PM And to figure out how to get into the rotor’s magnet assembly.... 01-Mar-20 05:40 PM You'd need to make that ring puller tool 01-Mar-20 05:40 PM Now, if you are certain you want to replace all of the magnetic bearing rings, you can also use heat 01-Mar-20 05:40 PM Or LN2 01-Mar-20 05:43 PM Ring puller? 01-Mar-20 05:44 PM This 01-Mar-20 05:44 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-7F068.png 01-Mar-20 05:44 PM So it's a ring with 4 set screws on the ID threaded to attach to the aluminum lip/ring above the bearing 01-Mar-20 05:46 PM thanks @LRM ! 01-Mar-20 05:50 PM Ah, I see what they did. 01-Mar-20 05:53 PM It's certainly possible you can get this back up and running for <$100 here 01-Mar-20 05:53 PM If you swap both bearings to dry ceramic ones, you should be able to run this upside down without worrying about lubricating it in the long term too 01-Mar-20 05:53 PM @samy One thing I'd recommend is to check your EXT255Hi's bottom lubricant reservoir, it's good to do preventative maintenance instead of potentially fixing a crashed pump in the future 01-Mar-20 05:53 PM Perhaps you can also email Andrew Seltzman to see if he has some magnets left over from his repair @rdpierce 01-Mar-20 06:09 PM @Mason_Yu ahh ok, thanks! the ISO100 flange just came in so i'm just finishing up design of the chamber plate 01-Mar-20 06:09 PM i'm trying to figure out what feedthroughs to connect -- should i have multiple KF16/25s in the plate, or just one KF25 that i can connect to a T for gas inlet valve+pressure sensor+release valve? 01-Mar-20 06:09 PM i'm a bit space constrained for the chamber (bell jar) 01-Mar-20 06:10 PM It's much easier to T off one port in your case when you are space constrained 01-Mar-20 06:10 PM Sensors and KF clamps take up space, so make sure they will be able to fit in CAD before you machine the port on the base plate 01-Mar-20 06:12 PM k 01-Mar-20 06:33 PM is there a reason someone would prefer machined aluminum vs standard (welded I assume) tee? and why you'd choose stainless vs aluminum? 01-Mar-20 06:52 PM stainless steel if you are using electron beam due to xrays produced from beam deceleration 01-Mar-20 06:52 PM aluminum works just fine 01-Mar-20 06:52 PM if you planning on doing plasma in chamber anodizing helps resisting it 01-Mar-20 06:52 PM what's your final application? 01-Mar-20 06:52 PM also which vacuum gauge? 01-Mar-20 06:52 PM I don't know about outgassing SS vs AL 01-Mar-20 06:52 PM SS is typically electropolished for HV applications 10-6Torr 01-Mar-20 06:52 PM I want to buy TIG and make my own chamber at some point but also would like to get things to not take 6 month for each project otherwise I won't finishing anything lol 01-Mar-20 07:12 PM i hope to work on lots of projects but atm i'd like to do magnetron sputtering 01-Mar-20 07:12 PM BPG400 sensor 01-Mar-20 07:12 PM so the steel is better at trapping xrays vs aluminum? 01-Mar-20 07:12 PM metal density 01-Mar-20 07:12 PM AL is 3 times less dense than IRON 01-Mar-20 07:12 PM for sputtering it doesn't matter 01-Mar-20 07:12 PM as long as it's clean 01-Mar-20 07:12 PM thus PB is used for x-ray shielding 11g/cm3 01-Mar-20 07:12 PM vs iron 8.9 or something 01-Mar-20 07:12 PM ah no around 8 01-Mar-20 07:12 PM why no MKS 9xx Pirani? 01-Mar-20 07:12 PM also you might want to shield it from main chamber 01-Mar-20 07:12 PM plastic centering rings and plastic clamp 01-Mar-20 07:36 PM <𝓕ermion#6024> I wonder how hard it is to learn to weld vacuum tight aluminum. 01-Mar-20 07:40 PM Not bad if you don’t care about porous welds 01-Mar-20 07:44 PM I dunno I keep hearing these things but also there are cheap parts from China and they work just fine 01-Mar-20 08:11 PM Aluminum welding generally requires AC TIG. 01-Mar-20 08:11 PM The trouble is that the aluminum oxide layer has a very high melting point relative to the metalic aluminum underneath. 01-Mar-20 08:11 PM I've never tried it. Stainless steel gives me more than enough trouble. You've really got to have good backing / purge gas or else you get sugaring on the other side. 01-Mar-20 08:11 PM I was given some advice for welding for vacuum. You generally just weld the inside of the chamber. 01-Mar-20 08:11 PM If you have to weld the outside as well for structural reasons, you use an interrupted bead. 01-Mar-20 08:15 PM @Yolo I have MKS901P for the foreline side - BPG400 gets to much higher vac than MKS 01-Mar-20 08:17 PM Weld a little, leave some unwelded. If you don't do that, and there's a small leak on an inside weld, then you won't be able to find it with a leak detector. 01-Mar-20 08:17 PM @Mason_Yu I'm interested in how you're arriving at the <$100 figure. I thought I saw Edwards rebuild kits for $750. 01-Mar-20 08:18 PM Oh I haven't seen those gauges interesting looks like they get that due to their fancy filament 01-Mar-20 08:19 PM Well, if you can ask for two of the rings from Andrew for $40 total, plus a $50 bottom bearing and add a little for shipping, it's about $100 01-Mar-20 08:19 PM You only need to replace these parts, if you don't want to replace the bottom bearing with a dry ceramic one you can get away much cheaper too 01-Mar-20 08:19 PM You know that major companies always put a big price tag on their rebuild/repair kits, no reason they should want to motivate you to fix existing stuff rather than buying a $4000 brand new pump that's a drop in replacement from them 01-Mar-20 08:19 PM @Yolo It's not fancy, just a regular full range gauge with a micro pirani and a Bayard Alpert gauge in one package 01-Mar-20 08:19 PM Talks serial, gives 0-10V output just like almost anything else 01-Mar-20 08:24 PM What about the oil, felt wicking, etc.? 01-Mar-20 08:24 PM If you get a dry ceramic bearing, it won't need any oil or felt wicking 01-Mar-20 08:24 PM @Mason_Yu ah ok just read it up thanks 01-Mar-20 08:26 PM So your existing oil sponge thingy is bad? Or is it just dirty? 01-Mar-20 08:45 PM welp this is unfortunate 01-Mar-20 08:45 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_2020-03-01_20.44.38-3E4CC.png 01-Mar-20 08:45 PM trying to get a KF25 + ISO100 + spark plug into this bell jar 01-Mar-20 08:45 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_2020-03-01_20.44.47-C64F6.png 01-Mar-20 08:46 PM It's discolored, black, dirty. 01-Mar-20 08:46 PM As I'd expect as the lower bearing ate itself. 01-Mar-20 08:46 PM And who is Andrew? 01-Mar-20 08:47 PM In that case I'd highly recommend you to go for dry ceramic bearing. Andrew Seltzman is the guy who wrote the blog about his repair at RFT Technologies 01-Mar-20 08:47 PM @samy Looke like you can get away with a tee instead of a cross 01-Mar-20 08:47 PM Or worst case just get a 90 degree bend 01-Mar-20 08:50 PM I've also made the ISO100 hole a bit smaller so i could move the TMP further away from the cross, I assume that's not a big deal? 01-Mar-20 08:50 PM Not an issue 01-Mar-20 08:51 PM any suggestions connecting the actual tee/90 degree bend to the aluminum plate? i could try welding it, though I'm terrible...could practice a bit before hand. would like to use this for highest vac possible as i'd like to keep doing diff experiments in here 01-Mar-20 08:52 PM Oh there's no need to weld it, all you need is a hole that's the OD of the lip of the centering ring, and a few blind tapped holes around it to put clamps on the KF25 flange 01-Mar-20 08:52 PM You can machine your own clamps, 3D printed ones will work in a pinch 01-Mar-20 08:53 PM ah so similar clamps to the one around the ISO one? 01-Mar-20 08:54 PM Something like that yeah, essentially just a toe clamp 01-Mar-20 08:55 PM ahh 01-Mar-20 08:55 PM If you are willing to spend a bit of money, there's also threaded solutions 01-Mar-20 08:55 PM https://www.ldsvacuumshopper.com/13131314.html 01-Mar-20 08:55 PM You can make that if you are quick on the lathe and have a grooving tool for the o-ring 01-Mar-20 08:56 PM and for the spark plug, it's M14, would i just add vacuum grease to that or should i also use a viton o-ring there? 01-Mar-20 08:56 PM ahh interesting 01-Mar-20 08:58 PM An o-ring won't work for a spark plug that takes either a preformed gasket or a copper crush gasket. You'd have to cut something out of a viton sheet. Also vacuum grease is recommended but don't go crazy 01-Mar-20 08:58 PM But yeah that's going to give you quite a bit of gas load 01-Mar-20 08:58 PM https://www.ebay.com/itm/BASEPLATE-FITTING-TO-KF-25-FLANGE-TO-1-INCH-TRANSITION-FEEDTHROUGH/164068733552?hash=item2633423270:g:nZIAAOSw0TxdBA6Q 01-Mar-20 08:58 PM For your KF feedthrough, this price is worth it 01-Mar-20 09:02 PM ahh nice...might try to turn something 01-Mar-20 09:02 PM to save $ for now 01-Mar-20 09:02 PM as i'm sure i'll need to buy a bunch of other stuff 01-Mar-20 09:11 PM @samy https://www.lesker.com/newweb/flanges/hardware_kf_clamps_bulkhead.cfm?pgid=al 01-Mar-20 09:11 PM ah that feed through looks nice 01-Mar-20 09:11 PM btw keep in mind clearance for your KF clamps 01-Mar-20 09:12 PM ah thanks Yolo 01-Mar-20 09:13 PM I had one turbo that was impossible to connect due to short flanges 01-Mar-20 09:13 PM going to add in clamps now...i think i'll just do an elbow as it's cheap and reduces risk if anything needs to move a little 01-Mar-20 09:14 PM had to buy longer threaded flange to be able to connect it 01-Mar-20 09:14 PM you will be using turbo with this sputter coater or what's ISO100 for? 01-Mar-20 09:18 PM yeah 01-Mar-20 09:18 PM or ISO100 for the source? 01-Mar-20 09:19 PM the big thing next to the cross is the TMP 01-Mar-20 09:23 PM you have mesh on shield for TP just in case something falls in? 01-Mar-20 09:23 PM ISO100 centering ring with mesh that's what I'm trying to say 01-Mar-20 09:24 PM yeah, TMP has mesh on it and just got centering ring 01-Mar-20 09:24 PM thanks for validating -- i have no idea what i'm doing so i'm open to all suggestions/things to watch out for 01-Mar-20 09:25 PM ah so it's Varian/Agilent then? 01-Mar-20 09:25 PM Edwards EXT255Hi, got it from Mason 01-Mar-20 09:25 PM I had to repair SEM that's how I learned 01-Mar-20 09:26 PM I have another EXT255Hi on my SEM 01-Mar-20 09:26 PM Leaky valve box and an unreliable foreline pump is holding me back though 01-Mar-20 09:27 PM I see, I never seen Edwards turbos 01-Mar-20 09:27 PM They are all over eBay 01-Mar-20 09:27 PM Have here Varian and Pfeiffer 01-Mar-20 09:27 PM My SEM is in my living room so I can't exactly run the foreline pump overnight when my roommates are sleeping 01-Mar-20 09:27 PM The Trivac D10E is quiet, but not that quiet 01-Mar-20 09:29 PM just get long SS bellows 01-Mar-20 09:29 PM That or a Welch belt drive pump 01-Mar-20 09:29 PM I'm eyeing another SEM here and that's the first thing I'll take off it 01-Mar-20 09:31 PM How I spent my summer 01-Mar-20 09:31 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Emj9F_FXzHjPVmX-5m1m3UL5FGng4OHn5YSorME5d7-37787.png 01-Mar-20 09:31 PM When you buy one SEM you can't buy JUST one 01-Mar-20 09:31 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/6Dlvk7uUevnYHP3kg3wyXD7N5TZuAbkWtydZ1hGu6V-32741.png 01-Mar-20 09:31 PM right one was basically part for the left one 01-Mar-20 09:33 PM hah nice 01-Mar-20 09:33 PM where are you located? 01-Mar-20 09:34 PM I have software and everything now for Zeiss SEMs 01-Mar-20 09:34 PM also many spare parts 01-Mar-20 09:34 PM trying to sell on eBay 01-Mar-20 09:34 PM @samy I'm vpikhur on Twitter 01-Mar-20 09:34 PM I literally went to a guy's garage, disassembled the SEM in 4 hours, stuffed it into the back of a friend's car and drove it back overnight 01-Mar-20 09:35 PM @samy Portland-ish, OR 01-Mar-20 09:35 PM close to Tektronix HQ 01-Mar-20 09:35 PM or Nike 01-Mar-20 09:35 PM Beaverton, OR 01-Mar-20 09:35 PM it is 2008 Zeiss EVO15 01-Mar-20 09:38 PM cool 01-Mar-20 09:39 PM running LaB6 now 01-Mar-20 09:39 PM oh sweet, didn't know that was you 01-Mar-20 09:39 PM but I have like 30 W filaments 01-Mar-20 09:39 PM h1kari was at my place the other day and i think talking about a project of yours 01-Mar-20 09:39 PM I didn't use Discord for anything but playing online with friends heh 01-Mar-20 09:39 PM and so nickname comes IRL V looks like Y 01-Mar-20 09:39 PM so 01-Mar-20 09:39 PM lol 01-Mar-20 09:39 PM nmz787 yes that's me 01-Mar-20 09:40 PM I thought that might have been you from the tiny profile pic here 01-Mar-20 09:40 PM Lol 01-Mar-20 09:40 PM What a coincidence 01-Mar-20 09:40 PM I finally gave in and Adam invited me lol 01-Mar-20 09:41 PM I was wondering why you weren't here a while ago 01-Mar-20 09:42 PM because I have projects to do? 01-Mar-20 09:42 PM @Yolo know any contractors/builders? I really want to triple my garage space 01-Mar-20 09:42 PM no but I can borrow my air compressor for air hammer? 01-Mar-20 09:42 PM Lol 01-Mar-20 09:43 PM let me check 01-Mar-20 09:43 PM I guess i really need to spend a few days on CAD of my house and garage and just start working with the city on a design that they'll approve 01-Mar-20 09:43 PM Kinda just want more garage to appear magically, with money handed over 01-Mar-20 09:43 PM But, that seems like a much much more expensive route that designing myself and finding subcontractors 01-Mar-20 09:44 PM I think I will just rent space 01-Mar-20 09:44 PM I have a friend in commercial real estate he has access to all the tools 01-Mar-20 09:44 PM But thats gonna be at least, what, 1-2k /month 01-Mar-20 09:45 PM yes but I can write it off my taxes 01-Mar-20 09:45 PM Times how many years you rent it 01-Mar-20 09:45 PM I can't do that with my house 01-Mar-20 09:45 PM Hmm, seems like a garage build out you could 01-Mar-20 09:45 PM I mean, i write off sq footage in my schedule C 01-Mar-20 09:45 PM I would consult with CPA 01-Mar-20 09:45 PM Haha 01-Mar-20 09:46 PM I'm actually going to meet with mine tomorrow 01-Mar-20 09:46 PM I've only used a CPA when me and some friends had an LLC together 01-Mar-20 09:46 PM https://www.islernw.com/good-and-bad-news-about-the-home-office-tax-deduction/ 01-Mar-20 09:46 PM And it seemed not that worth it 01-Mar-20 09:47 PM dunno mine was helpful and saved us money 01-Mar-20 09:47 PM I dunno how others but I claimed my bug bounties 01-Mar-20 09:47 PM I mean declared 01-Mar-20 09:47 PM and also writing of my Tek scope, spectrum analyzer, etc 01-Mar-20 09:48 PM Hehe, yeah I've written off my fib usage 01-Mar-20 09:48 PM also now I got customer so there should be some income going 01-Mar-20 09:48 PM hopefully to get contract soon going just sent SoW last week to them 01-Mar-20 09:48 PM Nice, congrats 01-Mar-20 09:48 PM Ah, almost congrats then 01-Mar-20 09:49 PM ye lol 01-Mar-20 09:49 PM NDA signed, SoW sent waiting on contract 01-Mar-20 09:49 PM hopefully survive this pandemic and it will be good 01-Mar-20 09:49 PM US is smart if you don't test nobody is sick 01-Mar-20 09:55 PM I already like working from home, this is just more justification for me and my manager and team 01-Mar-20 09:59 PM I've been traveling past month and feeling feverish and not 100% but I also had issue with my asthma so it is now hard for me to tell if I'm really sick or I have asthma problem 01-Mar-20 09:59 PM and ofc if I go will I be able to do test for the corona? 01-Mar-20 09:59 PM maybe I can test it with my SEM 01-Mar-20 09:59 PM also I got RIE system for testing 01-Mar-20 09:59 PM works ok 01-Mar-20 09:59 PM also I think I will build vacuum buffer for my SEM from beer keg 01-Mar-20 09:59 PM https://www.morebeer.com/products/kegmenter-fermentation-keg-153-gal.html 01-Mar-20 09:59 PM and this https://www.morebeer.com/products/stainless-triclamp-4-cap-pre-drilled-hole.html 01-Mar-20 09:59 PM then just attach flange somehow 01-Mar-20 10:04 PM 1. @rdpierce maybe aluminum welding is as hard as you say, but one of the least capable machinists/welders I know tried some vacuum welds for us and it turned out fine. I highly doubt he did it "properly" 2. @samy you can easily make something similar to these: https://www.lesker.com/newweb/flanges/hardware_kf_clamps_bulkhead.cfm?pgid=al 01-Mar-20 10:12 PM Has anyone put together 3D CAD files for common clamps, flanges, etc.? 01-Mar-20 10:12 PM lesker has all that 01-Mar-20 10:12 PM Or has dimensioned drawings? 01-Mar-20 10:12 PM hmmm 01-Mar-20 10:13 PM idealvac as well 01-Mar-20 10:15 PM Yeah. I have had to make my own "rough copies" of some parts to make them fit my model, and also have found my gate valve models on other random sites... Turbo manufacturers also will send you CAD models after like a two week delay if you email them 01-Mar-20 10:15 PM oh, said welder got back and said "well it was actually really hard" and that they had an AC TIG 01-Mar-20 10:24 PM AC TIG is pretty much required for aluminum. 01-Mar-20 10:24 PM Well I've heard of someone doing MIG with an aluminum wire spool gun. 01-Mar-20 10:24 PM anyways they have very little welding experience and still got it done, I imagine you could too 01-Mar-20 10:25 PM form my understanding you need rotatable to get good results 01-Mar-20 10:25 PM Also, I was looking at that webpage and it mentions a precision spring to preload the bearing. 01-Mar-20 10:25 PM I don't see that in the drawings. 01-Mar-20 10:25 PM I'm wondering if that's his own addition because he's apparently hacking in a ceramic upper bearing instead of the magnets? 01-Mar-20 10:31 PM the key to aluminum welds for vacuum stuff, from what i have been told, is surface prep surface prep surface prep 01-Mar-20 10:31 PM need to look into getting a tig setup myself to play with, the friend i was leeching off moved to Georgia 02-Mar-20 05:48 PM I've said it before, and I'll say it again... Pneumatic control of vacuum valves really annoys me 02-Mar-20 05:48 PM Now not only do i need to rig up my microcontroller to switch a relay for the electrically controlled pneumatic switch, but i need to deal with all the stupid hose fittings and getting the hose, etc... Which is sure to take a few orders of wrong parts and a bunch of time spent researching 02-Mar-20 06:23 PM woah woah 02-Mar-20 06:23 PM just use push-to-connect 02-Mar-20 06:23 PM no fittings 02-Mar-20 06:23 PM The 5/32 stuff on mcmaster is real nice 02-Mar-20 06:23 PM super flexible, colour codable, cheap 02-Mar-20 06:30 PM <𝓕ermion#6024> Do y’all have a list of compatible valves? Like this or that festo manifold and this valve and so and so. 02-Mar-20 06:30 PM <𝓕ermion#6024> Like I guess I’m looking for a section of a BOM 02-Mar-20 07:05 PM Am not sure what you mean by compatible 02-Mar-20 08:18 PM @idmb for example this datasheet says m5 or 10-32 unf... Which i haven't got a clue as to what they mean, the valve appears to have push to fit, but i don't see any tubing called m5 or 10-32 02-Mar-20 08:18 PM http://www.vatvalve.com/business/valves/product?id=26524-KA11 02-Mar-20 08:18 PM 26524-KA11 02-Mar-20 08:18 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/745917-ADA65.pdf 02-Mar-20 09:10 PM M5 and 10-32 are bolt types 02-Mar-20 09:21 PM *thread types, to be specific 02-Mar-20 09:21 PM If I stumbled upon those in my lab, I would buy some of these and move on: https://www.mcmaster.com/2684k26 02-Mar-20 09:21 PM Oh but if it already has push to connect, then your life is easy already? 03-Mar-20 12:35 AM I thought it looked like push to connect... Maybe I'm just not used to looking at these connectors 03-Mar-20 03:11 AM Anyone know what kind of electrical connector this is? For a VAT vacuum valve open/close indicator microswitches 03-Mar-20 03:11 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_20200303-031026-9C607.png 03-Mar-20 03:11 AM I'm a bit stuck... I see the value in having a switch to tell my control loop whether the valve has actually closed, to raise alarms and not proceed if there's a safety issue with mixing chemistries... But the seller of those says 'used, guaranteed not DOA' while another seller of valves without feedback switches says 'seller refurbished' and states they're from an Apple plant that never went into production before it was shut down 03-Mar-20 03:11 AM So maybe the latter are better quality (but probably not) 03-Mar-20 03:11 AM The sensor valves are like $2.50 more "expensive" 03-Mar-20 03:11 AM Also, i already have 2 of each dumb and sensored valves... So don't immediately need more, but I might use up two this week, and feel like I should have a few more on hand for my next deposition chamber build 03-Mar-20 04:55 AM looks like M8 or M12 03-Mar-20 05:13 AM I was going to say the same thing. 03-Mar-20 05:13 AM I've used M12 in my automated beer system for temp probes. 03-Mar-20 08:17 AM Tbh we’ve cut cables and put DSUB9 on before just to make things standard 03-Mar-20 08:50 AM M12 is standard :) 03-Mar-20 08:50 AM and M8 is also popular, Pheiffer uses it for fans of all things. 03-Mar-20 09:09 AM Standard within the lab * 03-Mar-20 09:09 AM We made it so the same control box can have a valve or turbopump plugged into any socket 03-Mar-20 10:43 AM @nmz787 that's the friggin goofy Turck connectors that they use with DEVICENET. There's weirdass combo blocks that essentially buss like 6 or 8 of those to get her that you can find at industrial surplus stores. 03-Mar-20 10:43 AM Devicenet is effectively a specialized version of CAN, as I understand it 03-Mar-20 10:47 AM Hmm, ok, I'll check at my local electronics surplus before buying online 03-Mar-20 10:47 AM Thanks everyone for identification help! 03-Mar-20 11:17 AM does anybody know how to test for COVID-19 at home? 03-Mar-20 11:17 AM PCR 03-Mar-20 11:17 AM Or a microarray/DNA paint 03-Mar-20 11:17 AM I've got all the equipment needed here except the DNA primers 03-Mar-20 11:19 AM yeah that's what I was thinking would need some pigment to highlight it 03-Mar-20 11:19 AM ask @piGuy , that's his area 03-Mar-20 11:19 AM I have SEM and several optical microscopes 03-Mar-20 11:19 AM getting tests is impossible basically 03-Mar-20 11:19 AM gov says risk is low but they don't test anything 03-Mar-20 11:19 AM and cases appear 200 miles away from first incident 03-Mar-20 11:20 AM Sem won't help 03-Mar-20 11:20 AM with people who haven't been to area of the spread 03-Mar-20 11:20 AM @nmz787 I saw TEM pictures it looked nice 03-Mar-20 11:20 AM Optical microscopes useless too 03-Mar-20 11:20 AM but I don't know what I'm doing 03-Mar-20 11:21 AM TEM is mich higher mag, and you still need heavy metal staining to see DNA 03-Mar-20 11:21 AM spit in the chamber see what happens 03-Mar-20 11:21 AM TEM is mich higher mag, and you still need heavy metal staining to see DNA @nmz787 yeah I know 03-Mar-20 11:22 AM All you need is a polymerase enzyme, a heat cycler, and rectangle to cast a gel of agarose in, then some stainless or platinum wires and a 50-100VDC power supply 03-Mar-20 11:22 AM I have W wire 03-Mar-20 11:22 AM a spools 03-Mar-20 11:22 AM And the primers, which short strands of DNA that have complementary sequence to something you're looking for, kind of like your regular expression when you're looking through text 03-Mar-20 11:22 AM The wire doesn't matter that much, especially if you're not using the DNA for any downstream purposes, in this case you just want to see a result at a specific distance in that gel I mentioned 03-Mar-20 11:22 AM Which is called gel electrophoresis 03-Mar-20 11:22 AM The wire matters more if you want to take that DNA after you've electrophoresed, and extract it from the gel and then use it for cloning 03-Mar-20 11:23 AM yes I know what is electrophoresis I was getting that when I was a kid and sick 03-Mar-20 11:23 AM so anyway 03-Mar-20 11:24 AM Sounds fun :/ 03-Mar-20 11:24 AM just have to order things from China and it's good? 03-Mar-20 11:24 AM Haha, nah 03-Mar-20 11:24 AM The-odin.com for the equipment and then something like twist bioscience for the primers, new England bio for the polymerase 03-Mar-20 11:25 AM + someone sick with COVID-19 03-Mar-20 11:25 AM for positive results 03-Mar-20 11:26 AM Yyyeaah 03-Mar-20 11:26 AM There's a good thread on this on diybio google group actually, where a lot of folksare not recommending DIY tests specifically because you have to deal with... Potentially infectious agents 03-Mar-20 11:26 AM Technically even isolating bacteria and fungi from soil samples is considered BSL2, which means you need more safety precautions, since stuff in the environment can be pretty infectious given the right environment to grow in and concentrations 03-Mar-20 11:27 AM so my SEM supposed to be for life science but I dunno how any of that is done 03-Mar-20 11:27 AM Well it can't see DNA at any reasonable resolution 03-Mar-20 11:27 AM It's more for cell to cell interaction 03-Mar-20 11:27 AM Or cell to environment 03-Mar-20 11:28 AM I sold my TEM sample holder because I thoguht I never gonna use it #regrets 03-Mar-20 11:28 AM ok i have to go out there ttyl hah 03-Mar-20 11:29 AM Like, "oh here's how this cell attached to this surface to form a biofilm... See its pseudopodia wrapping into the microstructure of the rock surface?" 03-Mar-20 01:17 PM And if someone were to start doing PCR testing for COVID-19, the FDA would pitch a fit. 03-Mar-20 01:17 PM Well, I'm at PS:One today. With a dead turbopump, a laptop with Fusion 360, some aluminum stock, and they've got a Tormach CNC mill. 03-Mar-20 01:17 PM Designing and making tools. 03-Mar-20 01:44 PM envious.. it seems like the only hackerspaces (designed for something other than sitting around on your laptop and writing JS for your startup) around here are for-profit and wacky expensive, or sketchy beyond belief and plagued with capital-p Problems 03-Mar-20 01:44 PM i had a brief gratis membership to TechShop and that was really cool & got me started on some formative electronics projects way back when, though i never got around to taking any of the $$tool training$$ classes 03-Mar-20 01:57 PM TechShop and I had ISSUES. I was offered a complimentary membership in exchange for a safety audit. I presented them with a filled legal pad and said “The things I put stars by are the easy and important things you can do by the close of business today. The check marks need to be done so you can show you’ve done due diligence and aren’t complete dinguses in the event of inspection by ANY regulatory authority.” Owner decided the wiser thing was to 86 me from his building. 03-Mar-20 01:57 PM I do not lament the passing of TechShop. 03-Mar-20 02:02 PM yikes 03-Mar-20 02:04 PM you forgot to put the asterisk at the end of the pad that said "if you ignore this the correct regulatory authority will pay you a visit" 03-Mar-20 02:04 PM well, neither their soldering stations nor their oscilloscopes exploded on me, so that much i can say was alright about them 03-Mar-20 02:04 PM . o O (which is not saying very much at all) 03-Mar-20 02:07 PM @rdpierce FDA would only care if you were offering a testing service... No one cares about genetic or science work in this country as long as it's not terrorism or engineering GMO humans 03-Mar-20 02:07 PM Or drugs or explosives 03-Mar-20 02:38 PM Joined the server. 03-Mar-20 02:41 PM Joined the server. 03-Mar-20 02:44 PM hello there, new people :3 03-Mar-20 02:57 PM Take a moment to introduce yourself over in #introductions_and_directory! 03-Mar-20 03:05 PM @nmz787 good point to clarify.... If you started offering COVID-19 testing or kits to others in any publicly visble fashion, then they'd care.... 03-Mar-20 03:05 PM Kits maybe not even so much... As long as you weren't selling diagnosis 03-Mar-20 03:05 PM Josiah Zayner of the-odin actually got fingered by someone and the state of California got involved, and it went nowhere 03-Mar-20 03:06 PM Tool designed.... This should unscrew the bottom bearing covers and the top magnetic bearing screw-on plug. 03-Mar-20 03:06 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-14385.png 03-Mar-20 03:06 PM CAM time.... 03-Mar-20 06:23 PM does anybody know a good way to dissolving polyimide (kapton)? 03-Mar-20 06:23 PM my current approach takes too long too tedious 03-Mar-20 06:23 PM 4 known substances that can dissolve kapton afaik: 03-Mar-20 06:23 PM 1) Ammonium Hydroxide 03-Mar-20 06:23 PM 2) Hydrazine 03-Mar-20 06:23 PM 3) KOH 03-Mar-20 06:23 PM 4) Etylenediamine 03-Mar-20 06:23 PM I haven't tested no.3 yet but also it there are some implications for my application 03-Mar-20 06:23 PM I know for the fact no.2 works super well 03-Mar-20 06:23 PM my current approach is hot sulfuric acid 03-Mar-20 06:23 PM but that takes too long to bring it to high temperature and then boil takes about 10min 03-Mar-20 07:50 PM Joined the server. 03-Mar-20 07:52 PM Why are you favoring H2SO4 now? Just availability? 03-Mar-20 07:53 PM Joined the server. 03-Mar-20 07:54 PM Joined the server. 03-Mar-20 08:24 PM Why are you favoring H2SO4 now? Just availability? @Addison-110m correct and it would oxidize metal and not etch copper 03-Mar-20 08:57 PM <上海#1372> Joined the server. 03-Mar-20 08:58 PM Joined the server. 03-Mar-20 09:00 PM Why so many new people and no new #introductions_and_directory entries? SHAME 03-Mar-20 09:00 PM <上海#1372> We're all from a physics server 03-Mar-20 09:00 PM <上海#1372> For admins or members that are nervous, no it's not a raid. We're just curious 03-Mar-20 09:01 PM if you're also grad students 03-Mar-20 09:01 PM be prepared to realize you overspend by about a factor of 10 03-Mar-20 09:01 PM <上海#1372> It's a good thing I don't build anything 03-Mar-20 09:02 PM do theorists even know what vacuum chambers are? 03-Mar-20 09:02 PM <上海#1372> Loaded question 03-Mar-20 09:04 PM any other helium droplet people? 03-Mar-20 09:04 PM or atomic optics? 03-Mar-20 09:05 PM <上海#1372> I was going to say Mez should be in here 03-Mar-20 09:05 PM mez was here first 03-Mar-20 09:05 PM I'm also in that server, and no. The only quantum optics person there hasn't joined 03-Mar-20 09:06 PM lame I just want all the helium droplet people here 03-Mar-20 09:06 PM You're the first one I've ever met not IRL 03-Mar-20 09:06 PM And the ones IRL are cheating 03-Mar-20 09:06 PM Either group mates or my bosses former postdoc/his student 03-Mar-20 09:06 PM I just love how the systems are all copies of one another 03-Mar-20 09:07 PM It's a tad ridiculous, yeah 03-Mar-20 09:07 PM but then the one my group built first got everything fundamentally wrong except the nozzle 03-Mar-20 09:07 PM That schematic was...something 03-Mar-20 09:07 PM It's such an inbred field though. They probably exist, but I can't think of anyone who wasn't in there early who later said "you know, droplets seem really good. Let's do that." 03-Mar-20 09:10 PM isn't that because of how new it is though? 03-Mar-20 09:10 PM And honestly if anyone at any moderately well-known institution decided to build a droplet machine, they could also just send like 10 different emails to other authors and a week later have a few CAD files of nice systems. 03-Mar-20 09:10 PM in our case it was because we had $0 when it was convenient to start the project 03-Mar-20 09:15 PM That's definitely true. It's not like velocity map imaging set ups are exactly unique either, and that's kind of more comparable to what droplets are. A specific technique 03-Mar-20 09:19 PM I call them KE per Q because too many people get confused by “velocity” 03-Mar-20 09:20 PM Fair 03-Mar-20 09:29 PM <𝓕ermion#6024> @funranium can I join your techshop complaining? 03-Mar-20 09:29 PM <𝓕ermion#6024> I despised that place 03-Mar-20 09:29 PM <𝓕ermion#6024> they had arranged their milling machines so they'd shoot parts at the neighboring operators 03-Mar-20 09:29 PM <𝓕ermion#6024> you always put mills in the corners of the rooms, and when you put them in the center, you put in shields. 03-Mar-20 09:30 PM Joined the server. 03-Mar-20 09:30 PM <𝓕ermion#6024> There was a mill there that made a truly awful racket and I told the safety guy, and he just turned up the RPM until the sound went away and went "see, it's fine!" 03-Mar-20 09:30 PM <𝓕ermion#6024> my worst memory is someone trying to run a fly cutter in aluminum at full bore on one of the mills with maybe a 10 thou depth of cut 03-Mar-20 09:30 PM <𝓕ermion#6024> it sounded like a very angry fan. I ran out of the room and screamed around the corner to turn it off 03-Mar-20 09:32 PM See this is why we don’t get Cnc access 03-Mar-20 09:33 PM <𝓕ermion#6024> Nothing wrong with giving people CNC access... you just need proper supervision and training. 03-Mar-20 09:33 PM Our department has a spare cnc, the old one from the mech shop 03-Mar-20 09:33 PM But they decided to put it in storage rather than the student shop with Bridgeport mills 03-Mar-20 09:33 PM Because they decided we would be more careful with a manual mill 03-Mar-20 09:33 PM The student shop is unsupervised. 03-Mar-20 09:33 PM You do a 40 hour course and then have to work in pairs always, but it’s open 24/7 03-Mar-20 09:35 PM <𝓕ermion#6024> that's wild 03-Mar-20 09:36 PM Which part? 03-Mar-20 09:37 PM <𝓕ermion#6024> unsupervised shop 03-Mar-20 09:38 PM For which reason? Safety or logistics running it? 03-Mar-20 09:39 PM shudders involuntarily at @𝓕ermion's tales 03-Mar-20 09:48 PM Once you train the students, you can set them loose in the shops. I find the Physics student shop has the best capabilities. Not the cleanest by any stretch of the imagination, but versatile and talented. 03-Mar-20 10:08 PM blushes 03-Mar-20 10:08 PM Most physics grad students have a lot more dangerous stuff in their labs, and have a lot less than 40 hours of proper training / supervision on any of that. 03-Mar-20 10:10 PM Sadly true 03-Mar-20 10:11 PM Danger is relative. One person's exotic is mundane to another. Lathes are pretty straightforward and yet PhDs keep losing pieces of themselves on them. Weird. 03-Mar-20 10:12 PM the best part of lathes are institutions that mandate people wear gloves when operating them... 03-Mar-20 10:12 PM why get a flesh wound when you can seriously injure your entire hand/arm 03-Mar-20 10:15 PM our student shop has all the safety glasses at the back 03-Mar-20 10:15 PM so when you enter it, you walk pass three mills and four lathes to get to the safety glasses 03-Mar-20 10:15 PM the lathes are unenclosed, of course. 03-Mar-20 10:15 PM Why just work with beryllium when you can throw Be swarf all over the room? EVERYONE LOVES LATHES!!! 03-Mar-20 10:15 PM shakes head sadly 03-Mar-20 10:16 PM how do you feel about LN2 ice cream? 03-Mar-20 10:16 PM Ugh 03-Mar-20 10:16 PM @idmb Have you considered keeping a pair of safety glasses at your desk and putting them on before you head to the shop? 03-Mar-20 10:16 PM no I just cover my eyes with my hand and walk to the back blindly 03-Mar-20 10:17 PM Made and had it many times. LHe ice cream is better, though much more expensive. 03-Mar-20 10:17 PM if I count my steps just right I can find them first try 60% of the time 03-Mar-20 10:20 PM @funranium what was the situation where anyone was turning Be on a lathe without dust extraction/enclosure? just lack of understanding the potential of things going very very badly for many reasons? 03-Mar-20 10:20 PM <𝓕ermion#6024> Have you actually made LHe ice cream? 03-Mar-20 10:20 PM Yes 03-Mar-20 10:20 PM <𝓕ermion#6024> We sometimes literally have too much helium. 03-Mar-20 10:20 PM <𝓕ermion#6024> And a liquifier 03-Mar-20 10:20 PM <𝓕ermion#6024> Why is it better? 03-Mar-20 10:20 PM <𝓕ermion#6024> I feel very much like I’m being trolled but I wanna see where this goes. 03-Mar-20 10:22 PM Much smoother, like licking delicious silk. Really, the mouthfeel is awesome. 03-Mar-20 10:23 PM You could donate that helium to my "I would really like to use ultra high purity helium instead of argon as a buffer gas in my mercury set up" fund 03-Mar-20 10:23 PM I'm not sure how, but 03-Mar-20 10:23 PM @LRM as for the Be lathe, it is the traditional answer, i.e. Tradition. "This mill has always been run this way. Besides, the room ventilation is enough." 03-Mar-20 10:23 PM that hurts on so many levels 03-Mar-20 10:24 PM <𝓕ermion#6024> N o r m a I i z a t i o n 03-Mar-20 10:24 PM <𝓕ermion#6024> O f 03-Mar-20 10:24 PM <𝓕ermion#6024> D e v i a n c e 03-Mar-20 10:24 PM Yes it did. I didn't like going in that building if I could help it. 03-Mar-20 10:26 PM I know a lab that never uses laser safety goggles for anything. They have fun things such as an excimer, like 10 giant YAGs, and multiple dye lasers 03-Mar-20 10:26 PM You can probably guess why they don't 03-Mar-20 10:26 PM And you'll probably tear your hair out 03-Mar-20 10:27 PM They move faster than light and can dodge the beams? 03-Mar-20 10:27 PM Of course 03-Mar-20 10:28 PM <𝓕ermion#6024> Okay I apologize to the admins for setting off the language filter constantly. 03-Mar-20 10:28 PM At least they don't use gratings so things tend to be contained 03-Mar-20 10:28 PM But still 03-Mar-20 10:28 PM I actually know a lab worse than that thinking about it 03-Mar-20 10:28 PM Also don't use goggles, and if they need to move a beam across the room, they put up a sign that says "do not walk here. Laser beam" 03-Mar-20 10:29 PM @𝓕ermion It's cool. The language filter is a challenge. On a positive note, it has lead me to swear at some grad students less IRL. 03-Mar-20 10:29 PM That...THAT IS NOT HOW YOU DO THAT! 03-Mar-20 10:30 PM Yeah... 03-Mar-20 10:30 PM I also think they put a hole in the wall to get the beam to a different room once 03-Mar-20 10:30 PM Like just with a sledgehammer 03-Mar-20 10:31 PM I had to ask another grad student to at the very least put up a sign 03-Mar-20 10:31 PM if they were going to shine the beam outside their enclosed optical table 03-Mar-20 10:32 PM ...y'all do actually have Laser Safety Officers at your institutions, right? 03-Mar-20 10:32 PM No. 03-Mar-20 10:32 PM I don't believe so 03-Mar-20 10:32 PM If they exist, they've never actually came by 03-Mar-20 10:32 PM Though the worse one I talked about is in Taiwan 03-Mar-20 10:33 PM We had the chem officer tell us we had to move a poster in the hall 03-Mar-20 10:33 PM that someone had put up covering the fire escape plan map 03-Mar-20 10:33 PM They apparently exist 03-Mar-20 10:33 PM I have never seen, met them, or gotten an email from them though 03-Mar-20 10:33 PM The chemical safety people are pretty prevalent 03-Mar-20 10:34 PM we have an online quiz for laser safety 03-Mar-20 10:34 PM But I never see the laser safety people 03-Mar-20 10:34 PM We don't even have that 03-Mar-20 10:34 PM I think the problem is 03-Mar-20 10:34 PM Things like don't shine the beam across the room 03-Mar-20 10:34 PM are common sense 03-Mar-20 10:34 PM so no course that tells you not to do it 03-Mar-20 10:34 PM would help 03-Mar-20 10:35 PM Just checked their job description. THey're batting a nice 3/14 03-Mar-20 10:37 PM @funranium the grad student before me had a great idea for far field alignment 03-Mar-20 10:37 PM instead of sending the beams across the room and then struggling to see if they were aligned using a camera 03-Mar-20 10:37 PM they doubled the path length by putting a mirror over there 03-Mar-20 10:37 PM and sent them back at themself 03-Mar-20 10:37 PM so they then just face away from the optical table 03-Mar-20 10:37 PM and stare at the crosshairs on the wall 03-Mar-20 10:38 PM That is familiar. 03-Mar-20 10:38 PM and adjust the mirror behind them. 03-Mar-20 10:42 PM So, thanks you two. Sometimes I feel bad that I don't get out into the labs for inspection and helping out with builds enough. That it's almost a thousand users for two people to cover. But, well, we are knowledgeable and we are actually getting out there. It's a bit of perspective that makes me kinda worried for you that your institutions aren't giving much support. 03-Mar-20 10:43 PM AFAIK the only laser injury in the past decade at my institution is someone checking a telescope with a dentist mirror. They "forgot to block the beam" 03-Mar-20 10:44 PM We hadn't had any injuries at $MAJOR_LASER_MANUFACTURER until I pulled the thread on something and found 6 employees with scorched retinas in a single room. 03-Mar-20 10:44 PM Because they didn't want to report. 03-Mar-20 10:45 PM They were at the very least doing the alignment with just the oscillator and no amplifier. I believe the "dark spot" in their vision was "gone" within a week. 03-Mar-20 10:45 PM I think there's only been one incident period AFAIK. It was the no goggles lab and it happened during periscoping 03-Mar-20 10:45 PM Which you know, if there's anytime to wear goggles, it's periscoping, but... 03-Mar-20 10:46 PM How untrue is "if you get hit by the beam you will know" ? 03-Mar-20 10:46 PM And look if you want to make me feel safer, having safety ratings for chemicals that are meaningful and easy to interpret will help loads more IMO 03-Mar-20 10:47 PM I'm actually not convinced that there actually is a laser safety officer looking a bit farther into it. The description they have on the website is literally just from the ANZI appendix 03-Mar-20 10:47 PM ^ 03-Mar-20 10:47 PM That's a big one 03-Mar-20 10:47 PM That's where intuition just doesn't exist. 03-Mar-20 10:47 PM With lasers, anyone who wants to be safe can be safe and the main risk is that they're interacting with others 03-Mar-20 10:48 PM More or less every synthetic chemist asks people who know how dangerous the chemical they're working with ACTUALLY is rather than any official thing 03-Mar-20 10:48 PM Because the SDS makes it sound like you'll die if you touch sulfuric acid, but in reality you won't even feel it for like a minute. Albeit you don't want to bathe in it. 03-Mar-20 10:49 PM Yeah. And the poor grad students in YOLO labs where the PI just says "it's pretty safe" about anything 03-Mar-20 10:49 PM And not super relevant for lab scale stuff, but it'd be nice to have more training courses on scale up issues 03-Mar-20 10:49 PM Those are the PIs I get to go to war with on behalf of his, and it is almost always his, students. 03-Mar-20 10:50 PM again - soviet research tech who was surprised I didn't want to ride in an elevator with the LN2 dewar. Even when I pointed out the elevator had a sign that said it had zero ventilation 03-Mar-20 10:50 PM The sulfuric acid being a good example. 10 mL? YOu'd have to try to hurt yourself. 10 gallons? Yeah, we probably have a real issue 03-Mar-20 10:50 PM Nothing like a drop of 18M H2SO4 on your hand to really get your attention. 03-Mar-20 10:51 PM It actually takes a while to feel 03-Mar-20 10:51 PM Besides the wet sensation anyway 03-Mar-20 10:51 PM Not at 18M. Pretty immediate and scarring, as my hand still shows 25 years later. 03-Mar-20 10:51 PM clearly 18M 25 years ago was stronger than 18M now 03-Mar-20 10:51 PM A drop did that? 03-Mar-20 10:51 PM just don't make it like they used to 03-Mar-20 10:52 PM No glove. 03-Mar-20 10:52 PM we needed like 2L of 2M once 03-Mar-20 10:52 PM chem stores only sold 5L things of 18M 03-Mar-20 10:52 PM Because I did the same during my undergrad orgo lab, and I kind of sat there for about 5 seconds processing what happened, and then washed it off, and it didn't even turn red 03-Mar-20 10:53 PM You must be a real basic person then 03-Mar-20 10:54 PM If I were real basic, I would DEFINITELY have a scar 03-Mar-20 10:54 PM It gets hot enough in water 03-Mar-20 10:55 PM Hi I work in a chemical physics lab but I don't know first year chemistry. 03-Mar-20 10:55 PM <𝓕ermion#6024> @funranium at my grad school we were REQUIRED to ride in the elevator with the dewar. 03-Mar-20 10:55 PM ...oh god 03-Mar-20 10:56 PM <𝓕ermion#6024> Just in case an undergrad wandered in we had to tell them to shoo 03-Mar-20 10:56 PM wait wait Mez you'll love this quote from one of Henrik's students 03-Mar-20 10:56 PM "Wow, a black hole sure looks like a poorly focused VMI on a burnt MCP" 03-Mar-20 10:56 PM It really does 03-Mar-20 10:56 PM I honestly kind of thought similar things to be perfectly honest 03-Mar-20 10:56 PM Less specific because I don't actually do that 03-Mar-20 10:56 PM But "wow, that looks shockingly similar to a blurry VMI" 03-Mar-20 10:57 PM But to answer @idmb's earlier question "How untrue is "if you get hit by the beam you will know" ?", it really depends on power, QSW or CW, pulse width and where on the retina. My injury was some bleaching in the periphery. Didn't even notice until I held up a piece of poster board and saw the discoloration in the corner. Get hit with a femto or atto system? The term for the experience is "thermoacoustic blast" as the crater you make may blow the retina off the back of the eye. 03-Mar-20 10:58 PM femto beams. 03-Mar-20 10:58 PM I'm told that that is terrifying and he heard it. 03-Mar-20 10:58 PM Ok awesome 03-Mar-20 10:58 PM I'd be surprised if you couldn't hear it honestly 03-Mar-20 10:58 PM I feel my vision is as good as ever. 03-Mar-20 10:59 PM I also wonder how bad for me the ablated graphite is 03-Mar-20 10:59 PM Because I can definitely smell it 03-Mar-20 10:59 PM Which isn't a good sign 03-Mar-20 10:59 PM Well, I guess it's probably oils and other misc stuff 03-Mar-20 10:59 PM Ablated graphite from beam dumps that is 03-Mar-20 11:00 PM Fun safety thing I did: I put a giant label on the sheets of lead in our storage room saying they are lead 03-Mar-20 11:00 PM previously that was not clear. 03-Mar-20 11:00 PM unfun safety thing: our cable trays are held up with hose clamps 03-Mar-20 11:00 PM fun safety thing: many, many, many hose clamps. 03-Mar-20 11:00 PM anyways I am glad to hear I have probably not been blessed by femto nonsense 03-Mar-20 11:02 PM PROTIP: from time to time you have to replace beam dumps. $NOBEL_LAUREATE learned this when he burnt through his 15yo beam dump on the second day with his new system. It sorta wasn’t up for the new hotness. 03-Mar-20 11:04 PM I have a beam dump behind my beam dump 03-Mar-20 11:04 PM #justincase 03-Mar-20 11:06 PM You have chosen...wisely. 03-Mar-20 11:06 PM that's on one beam. The other beam I set it up so behind the beam dump is just the laser enclosure 03-Mar-20 11:06 PM We have had at least three nobel prize winners visit our lab, one I know of from discussion, one because there's a chair that says "on feb 27 1993 Dr. Ramsey sat in this chair," and three because she came by last year 04-Mar-20 12:09 AM Joined the server. 04-Mar-20 12:27 AM wow, so many new people 04-Mar-20 12:27 AM Welcome everyone! 04-Mar-20 06:03 AM <𝓕ermion#6024> Three nanodroplet people, lol 04-Mar-20 06:03 AM <𝓕ermion#6024> What are the chances 04-Mar-20 07:03 AM slightly correlated 04-Mar-20 07:48 AM On the subject of LN2 ice cream.... 04-Mar-20 07:48 AM Baileys Irish Cream plus LN2 equals 34 proof bliss! 04-Mar-20 07:49 AM Heh, we made 40% ABV "sorbet" from jaloviina at one SRAL Summer camp (think the usual hacker camps, but with 90% radio amateurs). 04-Mar-20 07:49 AM In addition to tasting decent you could smuggle booze to the bar as a spread on your toast that way. 04-Mar-20 07:52 AM I introduced this to Adler Planetarium for their monthly adult-only nights. They discovered that it was a bit too potent, so at later events they started cutting it with vanilla ice cream mix. 04-Mar-20 07:52 AM Heh 04-Mar-20 08:06 AM PROTIP: do not add spiced rum to butterbeer when at Universal Studios. The result was an eruption of something similar to The Stuff from the movie “The Stuff”. The stain it left on my shirt is quite permanent. Tasted okay though. 04-Mar-20 10:43 AM @einball what kind of turbo are you trying to resurrect? 04-Mar-20 10:43 AM I’m working on an Edwards EXT70. 04-Mar-20 12:30 PM So, I need to spend ~$5k on equipment because the money will just disappear if I don't. Any ideas? Basically anything in the optics, high vacuum, or gas management world would do. Basically looking for things that would make life easier because most of the necessities are covered. 04-Mar-20 12:30 PM Though I think I'm definitely going to get a liquid nitrogen foreline trap from ideal and some thermocouple vacuum gauges 04-Mar-20 12:30 PM Also strongly considering a mass flow controller so we have a spare in case something goes kapoot 04-Mar-20 12:36 PM @rdpierce Turbovac 220, I guess the bearing is broken 04-Mar-20 12:36 PM It does not reach its intended pressure 04-Mar-20 12:36 PM It's still in the mail though 04-Mar-20 12:54 PM @Mezmorizor gosh i wish i had your kinds of problems 04-Mar-20 12:54 PM spares and extra consumables are good, extra vacuum gauges are always handy to have especially when debugging 04-Mar-20 12:58 PM and some thermocouple vacuum gauges 04-Mar-20 12:58 PM mail me 5k and I'll send you 30 Agilent 531 gauges 04-Mar-20 12:58 PM @Mezmorizor New here, what does your project all entail? In terms of optics I love the ND filter wheels and I always feel like I need more 1/2 lamdba waveplates.. 04-Mar-20 01:02 PM I like having a shelf full of valves of various types 04-Mar-20 01:02 PM and an unlimited supply of generic KF pieces 04-Mar-20 01:14 PM do you have any conflat in use anywhere on your system that gets disassembled, ever? you probably need more gaskets 04-Mar-20 01:14 PM needs to place a duniway order soon, too .. 04-Mar-20 02:17 PM tbf this is a rare occurence, though yeah, there are definitely perks to working in a fairly well funded lab. There are a couple of relatively specialized KF blanks I plan on getting too, and I guess I should say the LN2 trap and thermocouple gauges+controller aren't optional because I legitimately need those. We already have literal years worth of gaskets and...a lot of generic KF pieces, so we're good on that front. 04-Mar-20 02:17 PM My project is IR spectroscopy in helium nanodroplets, so they'd be IR optics stuff 04-Mar-20 02:17 PM The thing with optics though is that we don't really change things up much, the system is already highly tunable/for the purposes of this grant it's hard to meet the price minimum with optics 04-Mar-20 02:20 PM just look for more automation 04-Mar-20 02:20 PM any knobs you turn by hand? 04-Mar-20 02:20 PM I do need more posts and stuff like that 04-Mar-20 02:20 PM A couple 04-Mar-20 02:20 PM You could easily spend $5,000 just getting a nice supply of weird but useful thorlabs mounts 04-Mar-20 02:20 PM it's like $100 each 04-Mar-20 02:22 PM maybe I'll just buy a wavemeter to replace the terrible design one my boss had me make for my first project 04-Mar-20 02:24 PM what kind did you build? 04-Mar-20 02:24 PM i wanna make a terrible wavemeter 04-Mar-20 02:24 PM Lloyds Mirror 04-Mar-20 02:24 PM I'll find the paper, though the detector is kind of expensive 04-Mar-20 02:24 PM Like, by terrible I mean it does work, as far as I can tell it's wavefront limited (at least with our lasers), but between actual costs and how long I spent on it, so not worth it 04-Mar-20 02:24 PM https://www.osapublishing.org/ao/abstract.cfm?uri=ao-31-33-7083 04-Mar-20 02:24 PM Sci hub it if you don't have access to OSA 04-Mar-20 06:03 PM What's the physics server? 04-Mar-20 06:30 PM Joined the server. 05-Mar-20 12:54 PM Any chance any of you are in Chicago for Pittcon? 05-Mar-20 03:37 PM That was interesting. 05-Mar-20 03:37 PM High end instrument makers have a major new market. 05-Mar-20 03:37 PM Cannabis analyzers. 05-Mar-20 03:38 PM In what context? 05-Mar-20 03:38 PM Chemical analysis of it before sale? 05-Mar-20 03:41 PM Apparently yes. 05-Mar-20 03:41 PM Quantifying terpenes etc. 05-Mar-20 03:41 PM Shimadzu has made dedicated cannabis and hemp analyzers with canned analysis protocols so that it's push a button simple 05-Mar-20 03:41 PM Then again the people doing this aren't usually analytical chemists. 05-Mar-20 03:41 PM I don't know if I should be amused or sad that there are LC machines designed to be operated by stoners 05-Mar-20 03:55 PM I knew there were labs doing it, but I’m amazed by the pushbutton analysis 05-Mar-20 03:55 PM Then again, single purpose equipment, why give it bells and whistles it wouldn’t need 05-Mar-20 03:55 PM I’m almost tempted to get in touch with the person I know who ended up doing analytical work in that area. 05-Mar-20 03:59 PM @Addison-110m realistically there's probably more bells and whistles to make it pushbutton 05-Mar-20 03:59 PM I mentioned @rdpierce 's quote to an acquaintance who made his own low cost LC machine 05-Mar-20 03:59 PM And was trying to sell it 05-Mar-20 04:00 PM Fair, but in terms of settings that an operator could screw with 05-Mar-20 04:08 PM i remember seeing a tweet in which @funranium encountered an eye-rollingly rebranded cannabis sterilizer 05-Mar-20 04:08 PM also when i wandered off to a local HVAC wholesaler to get fittings and a vacuum gauge (in my 'oh god how do i convert anything to 1/4" flare fittings' bad-old-days), the guy behind the counter asked if i worked in the cannabis industry 05-Mar-20 04:08 PM my neon green hair probably didn't help 05-Mar-20 04:08 PM i was like 'no, why?' and he was like 'well if you get cannabis residue in that vacuum gauge it'll void the warranty, just so you know' 05-Mar-20 04:31 PM The XRAD 420. 05-Mar-20 04:31 PM No, it did not operate at 420kVp. But it did have a green housing to indicate it was for WEEEEEEEEED. 05-Mar-20 04:38 PM Reminds me of that Saturday night live sketch where the guy at some junk store just keeps saying "yeah, and you can keep your weed in there!" 05-Mar-20 04:38 PM @qualia those bad old days sre still pretty new to me... :/ I really wish there was a law to require all fittings to have what they are etched into the side so you can easily buy couplers/adapters 05-Mar-20 04:39 PM Also, as I later learned, the unit wasn’t really fit for the task of irradiating plant products for food & drug safety. 05-Mar-20 04:39 PM It's like "security by obscurity" 05-Mar-20 04:42 PM yeah it's so frustrating.. i tried to save money by using HVAC repair vacuum hoses + fittings as much as possible for a bit there, thinking it'd be cheaper in the long run & just coupling up to KF at the end. this was, in fact, not at all the case, and now i have a bunch of wonky HVAC hardware kickin around if i need to, like, purge an AC or something 05-Mar-20 04:42 PM Cannabis industry is very much in Wild West snake oil salesman territory for pretty much every product and process at the moment. Since the feds don’t regulate, FDA can’t be a part of any approval process. So, caveat emptor on all things. 05-Mar-20 04:43 PM i guess my toy medium-vacuum acrylic-and-crock-pot chamber has seen some use for such exciting activities as 'rapidly popping lots of bubble wrap for disposal' and 'drying stuff' 05-Mar-20 06:12 PM What’s the bubble wrap popping like? Or is it very much a non event 05-Mar-20 06:22 PM <𝓕ermion#6024> I love learning about chemistry by watching oil extraction product promotion videos 05-Mar-20 06:22 PM <𝓕ermion#6024> just learned about short path evaporators 05-Mar-20 06:22 PM <𝓕ermion#6024> wiped film evaporators rather 05-Mar-20 06:22 PM <𝓕ermion#6024> and a CIP (clean in place) systems... kinda cool 05-Mar-20 10:27 PM @rdpierce weed is so much more than just stoners being high :< :( 05-Mar-20 10:27 PM Or rather 'the cannabis plant' in itself 06-Mar-20 06:39 AM Apparently Shimadzu and Agilent are both getting into this space. 06-Mar-20 06:39 AM Pittconn is definitely worth seeing. 06-Mar-20 06:39 AM It’s like a candy store of lab equipment. 06-Mar-20 06:39 AM A lot of analytical chemistry, SEM, XRF, some vacuum, etc. 06-Mar-20 06:53 AM <𝓕ermion#6024> It's funny to see the kids I did dabs with in college with their sacred geometry hats and all that in youtube videos being like "Okay now we start the diffusion pump. Make sure the cold trap is full..." 06-Mar-20 06:53 AM <𝓕ermion#6024> it's almost as if... a large portion of being able to do science is finding sufficient motivation. 06-Mar-20 07:29 AM Yes 06-Mar-20 07:29 AM Motivation is everything 06-Mar-20 09:17 AM So .. I got this pump that supposedly does not reach its intended pressure. Seller said the bearing might be shot. However, I'm not so sure about it being broken. Rotor spins freely and I cannot feel any vibrations / hear anything out of the ordinary. Please excuse the barbaric method, I'm lacking the controller and yes, I have oil for it somewhere around. Do the experts agree? https://www.youtube.com/watch?v=PnF3COSGOnI 06-Mar-20 09:28 AM Is it supposed to have magnetic levitation? maybe that's what they were talking about being bad? 06-Mar-20 09:28 AM Those sort of pumps have a touchdown bearing, which might be what you're using in that video. 06-Mar-20 09:29 AM It's a Turbovac 220. It should not have a magnetic bearing .. I also cannot hear the rotor move when I turn it upside down 06-Mar-20 09:56 AM how do the heads of the screws on the outer housing look? 06-Mar-20 09:56 AM does it seem like anyone has had a go at them? 06-Mar-20 09:57 AM Yup 06-Mar-20 09:57 AM might be a pinched o-ring causing the problem w/ ultimate pressure 06-Mar-20 09:57 AM One is kind of worn out, so I suspect it had been opened and has to be brought up slowly 06-Mar-20 09:57 AM Hmm, I do have a torque wrench coming my way, so I will open it once that's here 06-Mar-20 10:04 AM Got my PVC pipe chamber gasket sealing edge sanded even better last night, then polished it to a mirror finish with some compound and a fabric pad attached to a drill.... Will post a pic later.. welded another piece of PVC plate/sheet to the bottom of the chamber in prep to drill another hole for another KF fitting to be attached, so the vacuum is at the bottom, just so when I introduce the gasses for deposition they pump past the substrate (even though I'm probably going isolate the chamber from the pump during the vapor introduction, so I might not actually drill the hole until I try things as-is first) 06-Mar-20 10:04 AM Hoping the polishing of the gasket face gets me a lower leak rate and/or better than the 100 mTorr I previously achieved 06-Mar-20 10:05 AM good luck to both of you 06-Mar-20 10:05 AM that PVC chamber seems like it has been a whole lot of work 06-Mar-20 10:05 AM are you getting results out of it that are promising? 06-Mar-20 10:08 AM 100mTorr is supposedly sufficient for the deposition process, but the other guy here just poked a need through a black rubber stopper and made an RTV plug for the syringe-facing side. He was expecting me to unplug the RTV plug and squirt in the water or chlorosilane with a micropipette... But I don't like the idea of a bunch of air leaking in, and the general feeling that I'd be giving up a LOT of process control 06-Mar-20 10:08 AM So I'm gonna try rigging up some pneumatically actuated KF isolation valves, between the chamber and a stub of pipe with one end blocked 06-Mar-20 10:08 AM So I'd just load up the pipe with my reagent, and when i want to introduce, i think I'll just be able to open the vacuum isolation valve and let the reagent evaporate into the chamber 06-Mar-20 10:31 AM Just casually squirting in chlorosilane? 06-Mar-20 10:37 AM Pretty much 06-Mar-20 10:37 AM (i haven't actually tried it) 06-Mar-20 10:37 AM Supposed to react with water to form HCl... But they didn't ship the liquid in a rubber-stoppered container for piercing with a syringe... So either they assume it's gonna be used in a glovebox, or it's not crazy reactive in the air 06-Mar-20 08:03 PM I am mostly familiar with Edwards pumps. The controllers output a 0-5V signal proportional to percent RPM. 06-Mar-20 08:03 PM There’s also a circuit that closes at a certain percentage (80? 90?) of max RPM. 06-Mar-20 08:03 PM I’m assuming the controller for that pump has a comparable output so you can see if it is getting up to full RPM. 06-Mar-20 10:35 PM 80% on mine 07-Mar-20 08:09 AM Nooooooooooo 07-Mar-20 08:09 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20200307_160913-0ABB4.jpg 07-Mar-20 08:11 AM I don't know what that is, but it doesn't look good 07-Mar-20 08:12 AM MicroChannel plate 07-Mar-20 08:12 AM Particle detector 07-Mar-20 08:12 AM I've got one left but it's much lower resolution and these things cost a tonne 07-Mar-20 08:15 AM F 07-Mar-20 08:27 AM I'm wondering about the feasibility of building one using DLA, but I'd have no idea how to coat a PCB / piece of meterial with that amount of accuracy & detail 07-Mar-20 08:30 AM ... HOW did that get damaged like that? 07-Mar-20 08:40 AM I'm guessing it was dropped... or potentially it sat in the back of my car for 4 months and rolled around a bit.................. 07-Mar-20 08:40 AM they're supposed to be stored in vacuum 07-Mar-20 08:41 AM yeahhh this was long out of vacuum when i got it 07-Mar-20 08:41 AM anyway now I have to find a new one 07-Mar-20 08:53 AM when you say Resolution, do you mean spacial or temporal? 07-Mar-20 08:53 AM because the first pic doesn't look like much spacial stuff 07-Mar-20 09:05 AM spacial probably 07-Mar-20 09:05 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Cutaway-view-and-basic-operation-of-a-micr-7B125.png 07-Mar-20 09:05 AM less holes per unit area 07-Mar-20 09:05 AM and all MCPs are pretty fast so I would be very surprised if a hobbyist was doing something where the speed difference between the faster and slower ones mattered ? 07-Mar-20 09:08 AM but you need a spacially sensitive anode for that 07-Mar-20 09:09 AM Spacial. 07-Mar-20 09:09 AM oh 07-Mar-20 09:09 AM phosphor screen usually 07-Mar-20 09:10 AM So phosphor screen would work well but this is at the end of a TOF setup 07-Mar-20 09:10 AM so actually temporal too 07-Mar-20 09:10 AM whoops 07-Mar-20 09:10 AM "too" ? 07-Mar-20 09:10 AM why would a tof need spacial Resolution? 07-Mar-20 09:11 AM Atom Probe Tomography 07-Mar-20 09:11 AM if it cares about spatial then it's not just a ToF 07-Mar-20 09:12 AM It's not, but it's at the end of a TOF setup. What comes before the TOF is a pulsed laser beam hitting an atomically sharp metal tip. Hang ons 07-Mar-20 09:12 AM pretty much anything with strong fields works as a ToF 07-Mar-20 09:12 AM doesn't make it a ToF 07-Mar-20 09:13 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Schematic-diagram-showing-the-principle-of-1428E.png 07-Mar-20 09:13 AM oh, I see 07-Mar-20 09:13 AM why are they going to different spots on the detector? 07-Mar-20 09:13 AM is it just a ToFVMI ? 07-Mar-20 09:14 AM That goes back to Field Ion Microscopy. You induce field emission on the tip, then see where it lands to get a pretty pattern, which you compute to get a 3D image of material structure 07-Mar-20 09:14 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/2-Figure1-1-CFB4F.png 07-Mar-20 09:19 AM tldr; it's much more than ToF, which you already know 07-Mar-20 09:20 AM fine xD 07-Mar-20 11:51 AM sigh 07-Mar-20 11:51 AM Ortecs maestro MCA software has three main controll buttons 07-Mar-20 11:51 AM GO, STOP and DELETE 07-Mar-20 11:51 AM guess who missclicked and just got rid of 5 hr worth of spectral data 07-Mar-20 12:16 PM NOOOOOOOOOOOOOOOOOOOOOOOOOOOOO 07-Mar-20 12:17 PM @Mason_Yu you suggested checking the oil reservoir on the EXT255Hi but not seeing any info in the manual on checking that - is it by turning it upside down and removing the bottom? 07-Mar-20 12:17 PM i think i have enough setup to test it, out least out of the interstage port today 07-Mar-20 12:18 PM Oh don't turn it completely upside down if you can avoid it 07-Mar-20 12:18 PM Oil will go down into your bearing and into the motor. Do it on its side if possible 07-Mar-20 12:18 PM Do you have the oil for it? 07-Mar-20 12:18 PM It has the mil spec MIL-PRF-6085D 07-Mar-20 12:18 PM https://www.skygeek.com/castrol-brayco-885-oil-lube-instrument-quart-27021aecz.html 07-Mar-20 12:18 PM Here's a cheap option 07-Mar-20 12:28 PM @GigaSquirrel May I ask where did you get your Maestro software from? 07-Mar-20 12:30 PM i don't, thanks 07-Mar-20 12:30 PM I want something to process collected spectral data, but hard to make changes with Cambio or Fitzpeaks 07-Mar-20 12:30 PM A friend knows someone who knows someone who has friends who wanted to make a safety copy off site.... 07-Mar-20 12:30 PM Ah 07-Mar-20 12:30 PM Can I be your friend 07-Mar-20 02:36 PM moin! 07-Mar-20 04:05 PM Someone of you said something about turbopumps not spinning up to full speed when they do not have their feedback for safety reasons. Am I correct on this? 07-Mar-20 04:20 PM What do you mean by feedback? 07-Mar-20 04:20 PM Like a vacuum sensor? Most controllers already have hall sensor feedback from the pump, just to drive the BLDC motor 07-Mar-20 04:20 PM And most are limited by their maximum power output to the motor, so it doesn't really need torque/power feedback 07-Mar-20 04:20 PM Except on the most enormous pumps 07-Mar-20 04:36 PM Feedback on turning 07-Mar-20 04:36 PM I have a pump, three phase, probably star configuration and 2 pins with infinite resistance towards each other (And 'case' pin). So I guess it's a shot sensor 07-Mar-20 04:37 PM It's possible that your pump might have hall effect sensor latch ICs integrated into the motor 07-Mar-20 04:37 PM In which case you might measure an infinite resistance 07-Mar-20 04:37 PM But most BLDC motor controllers won't even be able to start the pump without the sensors, so safety is quite irrelevant here 07-Mar-20 04:40 PM I do not have a controller. The seller said the pump won't spin up to full speed, so I'm guesstimating here. The drive part is not a problem. It's not the bearing, that sounds a bit worn but otherwise fine 07-Mar-20 04:41 PM Oh yeah just saw your video, that's quite a loud bearing 07-Mar-20 04:41 PM But it might be okay still. Like I said, these pump controllers output not a lot of power, so if the seller had the pump running under a large gas load, or there's excess friction in the bearings, it won't spin up to full speed 07-Mar-20 04:41 PM https://www.ebay.com/itm/Oerlikon-Leybold-Turbo-Drive-TD-400-Frequency-Converter-800073V0002-Pump-Control-/312812279896 07-Mar-20 04:41 PM Luckily the controller is not that expensive 07-Mar-20 04:51 PM is looking for diy :) 07-Mar-20 04:54 PM @GigaSquirrel did it need an activation key or anything? 07-Mar-20 04:58 PM Well you have to know what sensor it uses, the pinout of everything and make your own 3-phase BLDC controller. I think it's worth it to make a low ball offer to that seller just to have something that you know will work 07-Mar-20 04:58 PM You can access the bottom bearing by just taking off a cover, that's simple enough to do just to see if there are debris. But if you want to know the pinout for the sensors and find out what's the correct signal, you'd have to do a full tear down 07-Mar-20 05:03 PM Not gonna tear that down ... Would have to unscrew the rotor 07-Mar-20 05:03 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20200307_205722-52F16.jpg 07-Mar-20 05:03 PM If you have a bad sensor you'd have to tear it down anyway 07-Mar-20 05:03 PM Or a bad bearing 07-Mar-20 05:04 PM Yes 07-Mar-20 05:04 PM I think with a failed sensor, there's still BEMF, with a bad bearing, I can forget about using it, but I need to design that controller first any way 07-Mar-20 05:06 PM only if it is the magnetic bearing...the regular bearings are a fairly simple swap 07-Mar-20 05:06 PM They use two hybrid ceramic bearings 07-Mar-20 05:06 PM also hall sensors can be replaceable depending on where they are located, speaking from experience 07-Mar-20 05:06 PM ahh then definitely serviceable on the bearing front 07-Mar-20 05:06 PM Yeah, but you have to take out the rotor 07-Mar-20 05:06 PM I wouldn't know where to get one .. I suppose they cost upward of 100 bucks 07-Mar-20 05:07 PM you measure it and find the closest standard size you can fit in 07-Mar-20 05:07 PM Not really, hybrid ceramic bearings from China are as low as $30 to $40 up to 100krpm 07-Mar-20 05:07 PM If you want absolutely the correct OEM part you can also go to Alpine bearings and ask 07-Mar-20 05:07 PM Given they are permanently lubricated, that may be necessary 07-Mar-20 06:11 PM @meowter_space DLA? 07-Mar-20 09:56 PM has anyone tried using orthodontics Titanium-Molybdenum alloy arch wire for titanium sublimation? 07-Mar-20 09:56 PM looks like there's some Zirconium and Tin in there too, not sure how that would affect i 07-Mar-20 11:43 PM @Addison-110m yes, but it does not matter what you enter :D 07-Mar-20 11:43 PM some random Numbers and it works 07-Mar-20 11:44 PM Oh that’s nice to know. I just came into possession of an old copy 07-Mar-20 11:44 PM but my spectroscopy pc isn't connected to the Internet, your mileage may vary 08-Mar-20 12:33 AM Apparently there's also this https://sourceforge.net/projects/libdbase/ 08-Mar-20 05:10 PM any vacuum hackers in Los Angeles area? 08-Mar-20 07:35 PM @einball you may want to talk to @PeterZieba. He just took apart an Edwards turbopump controller. I don’t think he saw any programmable logic. It was largely a stock brushless motor controller. The pump communicates its max RPM by a resistor. 08-Mar-20 07:35 PM I don’t know how Leybold differs, but it looks to me like DIY might be possible, at least with Edwards. 08-Mar-20 07:41 PM <𝓕ermion#6024> would be wild if you could use an RC brushless motor ESC 08-Mar-20 07:52 PM Good luck finding one with the right voltage 08-Mar-20 07:52 PM In the end it's not that complicated, but you want your controller to be reliable and cost-effective. Some control logic will be needed, for starting... etc. 08-Mar-20 07:52 PM Someone who was on this server is working on his universal turbo driver. The tricky thing here is that some older motors works at up to 80V 08-Mar-20 07:54 PM @spirit was making a universal controller, but they're gone from here now :/ 08-Mar-20 07:54 PM Seems odd why anyone would ever leave this place, lol 08-Mar-20 07:54 PM And honestly, I don't think the hours you spend on a custom controller for a specific old pump would be worth it, compared to just spending the ~$125 on an old working controller 08-Mar-20 07:54 PM Maybe less, if you are good at negotiating on eBay 08-Mar-20 08:15 PM There's a discord server limit. It's pretty big, but it does exist and it's not some data structure limit 08-Mar-20 08:15 PM I think it's 100 08-Mar-20 08:15 PM But don't quote me there 08-Mar-20 08:15 PM 100 volts? 08-Mar-20 08:15 PM Server limit 08-Mar-20 08:15 PM YOu can be in 100 servers at once AFAIK 08-Mar-20 08:15 PM But no more 08-Mar-20 08:16 PM Ah 08-Mar-20 08:16 PM Which is why people would leave 08-Mar-20 08:16 PM Is anyone in that many? 08-Mar-20 08:16 PM I don't understand how they do it, but yes 08-Mar-20 08:16 PM @Mezmorizor someone just PMed me saying they were banned 08-Mar-20 08:16 PM Oh, rip 09-Mar-20 07:54 AM <𝓕ermion#6024> Hey anyone for an episode of America’s favorite game show: misconfigured linear motor OR railgun? 09-Mar-20 09:01 AM Yeah, sign me up 09-Mar-20 09:01 AM watches the payload fling off 30 degrees to the right 09-Mar-20 09:20 AM @rdpierce Thanks for the advice :) I'm slapping together a first test driver ~ 150V / 10A .. Let's see how this goes 09-Mar-20 09:22 AM That seems like a lot. 09-Mar-20 09:29 AM 100W, not 10A .. Should not be doing two things at once 09-Mar-20 09:29 AM I certainly don't want a one-time candle 09-Mar-20 04:43 PM Wait what, 150V? 09-Mar-20 04:43 PM Are you sure your pump wants 150V @einball ? 09-Mar-20 04:43 PM Here's the spec sheet for the controller that should be compatible with your pump 09-Mar-20 04:43 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-D991E.png 09-Mar-20 10:17 PM <𝓕ermion#6024> ok I got one for y'all 09-Mar-20 10:17 PM <𝓕ermion#6024> anyone seen a feedthrough that looks like this 09-Mar-20 10:17 PM <𝓕ermion#6024> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-59DC6.png 09-Mar-20 10:17 PM <𝓕ermion#6024> and a retainer like this 09-Mar-20 10:17 PM <𝓕ermion#6024> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-611EF.png 09-Mar-20 10:18 PM That is one blurry picture 09-Mar-20 10:19 PM <𝓕ermion#6024> it's on the floor of a room that's lit by one trouble light 09-Mar-20 10:19 PM <𝓕ermion#6024> the system is sitting mostly in the floor. 09-Mar-20 10:25 PM I think we have some of that 09-Mar-20 11:03 PM <𝓕ermion#6024> those feedthroughs? 09-Mar-20 11:03 PM <𝓕ermion#6024> if you have any info it'd be very helpful 09-Mar-20 11:03 PM <𝓕ermion#6024> I'm about to machine them myself, heh. 09-Mar-20 11:18 PM The retainer looks very familiar. Will check tomorrow 09-Mar-20 11:18 PM Can’t see the feed through well. 09-Mar-20 11:21 PM <𝓕ermion#6024> thankie 09-Mar-20 11:21 PM <𝓕ermion#6024> this is a very old model... all the manuals I can find online mention this being a fischer connector 09-Mar-20 11:21 PM <𝓕ermion#6024> but it very clearly isn't 10-Mar-20 02:33 AM @Mason_Yu did you pull those numbers from the Turbovac220 datasheet? Those are not the right ones, are my pump is from leybold/heraeus, a way older model than the datasheet lists. That's why it is so hard to find documentation on it... The same pump exists today but it is a different thing. The pump does not want 150, in fact the only thing it gets is a current. What I do is basically taking the NT10 and rebuilding it with a microcontroller instead of analog/digital logic. The NT10 can drive other pumps too, which is why it is able to produce 150v max. 10-Mar-20 02:33 AM (it also makes the smps smaller) 10-Mar-20 05:30 AM @𝓕ermion Those feedthroughs are probably speedivac flanges, it's an ancient system that got ditched in the 60's. It is in many ways the precursor to the KF- flange system, they share both purpose and an outer diameter similar enough to mate. They were usually clamped together with quick connect bolted clamps, but I have seen some with threading on the outside. Pretty hard to find nowadays, nobody has used them for 5 decades. I only have some because university trash is amazing. 10-Mar-20 07:55 AM @𝓕ermion Ultra-torr, maybe? 10-Mar-20 11:04 AM <𝓕ermion#6024> turns out they actually are fischer 10-Mar-20 11:04 AM <𝓕ermion#6024> but they're some older kind. 10-Mar-20 03:12 PM @𝓕ermionnot sure of the name but those connectors are used a lot by Oxford Instruments. We have loads like that on our cryostats 10-Mar-20 04:26 PM <𝓕ermion#6024> this is in fact an oxford cryostat, heh. 10-Mar-20 04:26 PM <𝓕ermion#6024> cryospares sells the replacement part. 10-Mar-20 04:26 PM <𝓕ermion#6024> simultaneously glad and not that glad that I don't have to make a make a replacement 10-Mar-20 04:26 PM <𝓕ermion#6024> I had it all in cad along with a CNC lathe toolpath 10-Mar-20 05:25 PM cnc lathe Our shop would kill for one of those 10-Mar-20 05:28 PM Oh nice. We don’t have that at PS:One. Everything we need to turn gets done by hand on a Clausing or LeBlond. 10-Mar-20 06:34 PM @einball Ah, if you already have a suitable controller, then it should definitely be doable. Best of luck, hopefully the bearings are all intact 10-Mar-20 06:35 PM <𝓕ermion#6024> currently playing with a superconducting magnet power supply 10-Mar-20 06:35 PM <𝓕ermion#6024> these relays are something else. When it starts ramping the current you hear a BANG when the switches click 10-Mar-20 06:35 PM <𝓕ermion#6024> put 100 amps through a bus bar I just cut out. 10-Mar-20 06:35 PM <𝓕ermion#6024> did a back of the envelope calculation to see what the voltage drop should be and I got it to a factor of 2 10-Mar-20 06:35 PM <𝓕ermion#6024> seems the power supply works. 10-Mar-20 07:22 PM anyone know why two of the screw holes on the trivac d2.5e are red? i see that in all pics...I used acetone to remove it from mine cause it was bugging me but notice it's on all of them on ebay 10-Mar-20 07:28 PM Only one on mine is red. 10-Mar-20 10:36 PM https://www.ebay.com/itm/Leybold-Trivac-D2-5E-Rotary-Vane-Vacuum-Pump/333300739421?epid=1317622646&hash=item4d9a45ad5d:g:a~AAAOSwPDBdWlmk 10-Mar-20 10:36 PM https://www.ebay.com/itm/Leybold-Trivac-D2-5E-Vacuum-Pump-Working/372828245637?epid=1317622646&hash=item56ce4b8e85:g:q~kAAOSwHf5dwBeZ 10-Mar-20 10:36 PM just trying to understand why they're red :\ 10-Mar-20 10:41 PM that is really odd, neither of mine have it but mine might be slightly older than either of those (no handles either) 10-Mar-20 10:42 PM bet its thread locker or something 10-Mar-20 10:42 PM or a tamper evidence thing for some reason? 10-Mar-20 10:44 PM yeah it almost looks like wax or epoxy that just left a residue in some of the screw holes (or fill them in the case of that new one) 10-Mar-20 10:44 PM the tamper evidence thing would make sense to me, make sure nobody has messed with the motor winding arrangement 10-Mar-20 11:14 PM On mine it's only on the head of the screw, not in the thread itself, so probably for tamper proof 10-Mar-20 11:21 PM i don't know if tamper makes sense there as that's only access to the switch/electrical -- mine actually does have tamper stickers but on the center between the left and right sides and in fact mine didn't even come with a power cord so i had to remove the screws 10-Mar-20 11:30 PM <𝓕ermion#6024> It looks like the magnet I have will go to 12 T at 2K and 10 T at 4 K 10-Mar-20 11:30 PM <𝓕ermion#6024> And to get to 2 K you use a lambda point fridge and need another 40 m3/hr pump... expensive 10-Mar-20 11:30 PM <𝓕ermion#6024> How is that juice worth the squeeze? 10-Mar-20 11:30 PM <𝓕ermion#6024> You need servo needle valve and extra interlocks and this sophisticated thing and an extra pump for another 2 T! 11-Mar-20 04:58 AM I need to articulate to myself why I need a drag pump... 11-Mar-20 05:02 AM because drag pumps are great 11-Mar-20 05:02 AM like an oildiff but oilfree 11-Mar-20 09:09 AM <𝓕ermion#6024> if you could buy any pump cart, which one would you get? 11-Mar-20 09:09 AM <𝓕ermion#6024> I really like the agilent/varian TPS-mobile things 11-Mar-20 09:40 AM Edwards too? 11-Mar-20 01:56 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200311_134444-1681C.jpg 11-Mar-20 01:56 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200311_134527-FB6C6.jpg 11-Mar-20 01:58 PM scroll! 11-Mar-20 01:59 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200311_135235-61F60.jpg 11-Mar-20 01:59 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200311_135334-6F65E.jpg 11-Mar-20 01:59 PM So is this thing bad looking mechanically? 11-Mar-20 01:59 PM ; The guy who gave it to me said that a repair shop said that it was beyond repair 11-Mar-20 01:59 PM There was no mention of this burn looking wiring though 11-Mar-20 02:05 PM what I can see looks fine? assuming you put a tip seal in 11-Mar-20 02:06 PM I've got some old seals that are pretty dirty, a new kit is $200 11-Mar-20 02:06 PM Didn't want to spend that though if this looked toasty to begin 11-Mar-20 02:06 PM Not sure why it has brown wires unless the motor was seizing or they had it connected to the wrong voltage 11-Mar-20 02:07 PM looks pretty good to me, funny that there are such obvious machining marks left in one of those but i suppose that is not the working surface 11-Mar-20 02:08 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20200311_140746-AE04D.jpg 11-Mar-20 02:08 PM Totally unrelated, this is a DMD chip that I milled into a bit 11-Mar-20 02:08 PM @LRM both sides have those swirl marks 11-Mar-20 02:08 PM That's where the tip seals would touch 11-Mar-20 02:08 PM I can only imagine either it's just super grimy, or some dust got in here and really scratched it up 11-Mar-20 02:10 PM the tip seals 11-Mar-20 02:10 PM Which seems like could spell disaster 11-Mar-20 02:10 PM are dusty 11-Mar-20 02:10 PM no no you have no idea 11-Mar-20 02:10 PM Idk much about them 11-Mar-20 02:10 PM one of ours when we took it apart 11-Mar-20 02:10 PM it looked like it was full of sawdust 11-Mar-20 02:11 PM But the tip seals seem quite soft 11-Mar-20 02:11 PM If some metal shaving got in there??? 11-Mar-20 02:11 PM Oh 11-Mar-20 02:11 PM Like a bad tip seal replacement or something? 11-Mar-20 02:11 PM Tech left some junk? 11-Mar-20 02:11 PM Turned it on and machined itself to death?? 11-Mar-20 02:12 PM yeah that might actually be what that is instead of machining marks...or they sucked in some abrasive stuff 11-Mar-20 02:12 PM That would be very bad 11-Mar-20 02:12 PM but they're so fast I don't think it should matter 11-Mar-20 02:12 PM I suppose I could go at it with a dremel and some high grit sandpaper to clean them off 11-Mar-20 02:12 PM Sandpaper on the dremel, i mean 11-Mar-20 02:12 PM just depends how deep those swirls are? can you check them out for surface roughness? 11-Mar-20 02:12 PM and i would not try the sandpaper on a dremel 11-Mar-20 02:13 PM Have you tried using the pump? 11-Mar-20 02:13 PM Hrmm, I'd have to like, drop some molten plastic in there and then image the plastic on my FIB 11-Mar-20 02:13 PM this is more like whet stone and a couple hours territory if they are actually the issue 11-Mar-20 02:13 PM Scratches there will scratch up your tip seals and shred them at a faster rate than normal 11-Mar-20 02:13 PM No I haven't turned it on 11-Mar-20 02:13 PM but the seals should still "seal" and it should still pump 11-Mar-20 02:14 PM Got it with no seals installed, and some grimy seals in a baggie 11-Mar-20 02:14 PM dremel + sandpaper is just going to make it waaaaay uneven 11-Mar-20 02:14 PM Uneven seems better than scratched like crazy 11-Mar-20 02:14 PM Uneven probably matters less than sharp edges. 11-Mar-20 02:14 PM Scratches seem like they'd rip the seals 11-Mar-20 02:14 PM sawdust 11-Mar-20 02:14 PM yeah if they are actual scratches go at it with a whetstone and smooth them out 11-Mar-20 02:14 PM Ok, I'll clean it up and install the old seals 11-Mar-20 02:15 PM what kind of pumping speed do you get if you run it without seals? 11-Mar-20 02:15 PM but do not use sandpaper 11-Mar-20 02:15 PM I don't think i can get a whetstone in there 11-Mar-20 02:15 PM ive got a few small pieces that ive glued to dowels for just this kind of thing 11-Mar-20 02:15 PM The width is like a pinky finger and almost 2 inches deep 11-Mar-20 02:15 PM Hmm 11-Mar-20 02:16 PM when i gotta spruce up the internal features of a part for someone beyond the off the mill finish 11-Mar-20 02:16 PM Brb gotta transfer a new sample into load lock 11-Mar-20 02:16 PM @LRM is there a certain whetstone to get, like, certain grit? 11-Mar-20 02:16 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20200311_142218-3EB70.jpg 11-Mar-20 02:16 PM Those are the parts i got, not sure what the springs are for, if they're even related 11-Mar-20 02:16 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200311_142823-10056.jpg 11-Mar-20 02:16 PM This is in the restrictor port 11-Mar-20 02:16 PM I guess that might have been the restrictor 11-Mar-20 02:45 PM @nmz787 i have a few different ones, depends how fine the surface finish needs to be. before i made up my little set i was literally using random size/shape pieces from a large one that i dropped. made the whole dropping thing sting a little less to find a use for the pieces 11-Mar-20 03:16 PM That tip seal is gross 11-Mar-20 09:32 PM @nmz787 what is that thing? 11-Mar-20 09:32 PM Edwards xds10 11-Mar-20 09:32 PM Oil free rough pump 11-Mar-20 09:43 PM cool 11-Mar-20 09:43 PM not familiar with the twisty thing...will read up on that type 11-Mar-20 09:46 PM Scroll pump 11-Mar-20 10:09 PM made a little spark plug KF adapter but realize the spark plug to adapter connection itself might leak...do i just fill the threads with vacuum grease? what sort of vacuum is expected with that? 11-Mar-20 10:09 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_8967-EF6B8.JPG 11-Mar-20 10:10 PM jb weld maybe? 11-Mar-20 10:12 PM as always it depends on pumping speed 11-Mar-20 10:25 PM oh 11-Mar-20 10:25 PM writes down 11-Mar-20 10:25 PM any specific docs suggested reading up on to learn more about speeds, how diff things affect vacuum, etc? 11-Mar-20 10:34 PM i do not have any specific suggestions and am far from the best person to answer that...but i have found pfeiffer's website a decent reference a couple times https://www.pfeiffer-vacuum.com/en/know-how/ 11-Mar-20 10:34 PM more for quick reference than anything in depth there 11-Mar-20 10:53 PM thanks! 11-Mar-20 11:00 PM The basic thing is that everything has some level of “off/outgassing,” “leakiness,” or “virtual leakiness.” That can typically be expressed as “a number of particles per unit area, per pressure that it’s in.” It is a “flux” of gas into your chamber that adds to the chamber pressure. Usually expressed in Torr L/s and usually you’re talking about low enough chamber pressures that the “flux” doesn’t really depend on the pressure. 11-Mar-20 11:00 PM So then you end up in situations where with one pump you might only get 0.5 torr 11-Mar-20 11:00 PM But with a 4x faster pump you get 0.125 torr. Etc 11-Mar-20 11:09 PM @samy grab some hysol ea 1c from Amazon 11-Mar-20 11:09 PM Mix by weight at 100:44 parts, or by volume at 2.5:1 11-Mar-20 11:09 PM The stupid box says one to one but then online in the full datasheet it says what I just recalled 11-Mar-20 11:09 PM @LRM why whetstone and not sandpaper? I have at most 2500 grit paper, with several grits between there and 400 11-Mar-20 11:09 PM Is whetstone much much higher grit? 11-Mar-20 11:14 PM you can start out with sandpaper if you want but the abrasive residue from stones is much easier to clean out of things than all the pieces of sandpaper abrasive in my experience 11-Mar-20 11:14 PM the grit on sandpaper really likes to get stuck in surfaces and sort of charges them with abrasive 11-Mar-20 11:14 PM have not had that issue with stoning things and they are a much finer grit 11-Mar-20 11:16 PM @nmz787 ok, thanks! 12-Mar-20 12:24 AM @LRM thanks for the info... I think I have a whetstone at home, I'll try whacking it to break it, and first check Amazon to see if they have some small ones cheaper 12-Mar-20 12:24 AM Actually I think I have something from harbor freight that might be a multi grit whetstone, with some diamond portion too 12-Mar-20 01:00 AM Wow, 1N4001 diodes are pretty much worthless compared to the 1N5817 schottky's 12-Mar-20 01:00 AM For freewheeling/flyback protection diodes on relays, etc... 12-Mar-20 03:19 AM Well, someone just paid for an eBay drag pump station (includes diaphram pump, drag pump, controllers, all in a housing together) 12-Mar-20 03:19 AM How many clamps do I need for an iso 63 flange? (Edit, looks like 3 or 4, just bought a pack of 5) 12-Mar-20 03:24 AM @samy I used epoxy on mine 12-Mar-20 03:24 AM https://gigabecquerel.wordpress.com/2019/06/02/quick-n-dirty-vacuum-feedthrough/ 12-Mar-20 08:05 AM Why not just use teflon tape? That would seal even if the threads aren't meant to like NPT 12-Mar-20 08:05 AM We also have some feedthroughs where someone just threaded them in and filled the threads with regular epoxy 12-Mar-20 08:05 AM and I'm sure on a higher vacuum scale they leak less than NPT 12-Mar-20 08:05 AM but... eh 12-Mar-20 08:18 AM <𝓕ermion#6024> hey anyone have any recommendations for favorite pump cart setup? I didn't really get many responses last time I asked 12-Mar-20 08:18 AM <𝓕ermion#6024> there's these icart mobile thingies from ideal vacuum 12-Mar-20 08:20 AM they're typically called turbo stations, if that helps you search for more 12-Mar-20 08:20 AM <𝓕ermion#6024> ah okay 12-Mar-20 08:22 AM I've seen four or five Pfeiffer HiCubes and one edwards one. That's it in the area of labs I sometimes walk through.... The pfeiffer ones are pretty... But I imagine any/all of them work about the same, with the exception of some being fully oil-free and some being drag only (safer if the inlet pressure spikes at the cost of lower pumping speed) 12-Mar-20 09:46 AM @Mason_Yu No, I don't have one .. yet. I'm trying to build my own at the moment (: 12-Mar-20 09:46 AM Uhu Endfest 12-Mar-20 09:49 AM Uhu endsieg für everything 12-Mar-20 11:42 AM @𝓕ermion i just bought a drytel 31... So i guess it's my fav... Local pfeiffer sales rep recommended a HiCube, but it wasn't a drag which I was interested in, incase my chamber implodes or I mess up otherwise in some fittings (or say trip on something and disaster ensues) 12-Mar-20 01:08 PM ah rad, thanks @GigaSquirrel! 12-Mar-20 02:10 PM <𝓕ermion#6024> I don’t think I understand the difference between a drag pump and a turbo pump 12-Mar-20 02:10 PM <𝓕ermion#6024> What’s the main difference? 12-Mar-20 02:14 PM when people are talking about drag pumps, afaik, they are talking about holweck pumps 90% of the time 12-Mar-20 02:14 PM https://gigabecquerel.wordpress.com/2019/10/22/molecular-drag-vs-turbomolecular-pump/ 13-Mar-20 10:13 AM Does anyone know a book about capacitive sensing on phones? (I mean, a book that talks that kind of thing, not one so specific. 13-Mar-20 10:13 AM I remember the Aplied Science ITO tests. 13-Mar-20 10:13 AM (before anyone points them out) 13-Mar-20 10:33 PM huh @nmz787 I also have a drytel 31, haven't been able to test it (not doing much vacuum stuff since I got it) 13-Mar-20 10:33 PM (but I got mine for real cheap) 13-Mar-20 11:21 PM anyone know how long it takes before titanium begins sublimating and if i need to reach a specific pressure? trying to sublimate it at ~8 torr with ~7A (15V) running through some titanium wire 14-Mar-20 12:46 AM what gauge wire? 14-Mar-20 01:04 AM 24 gauge 14-Mar-20 12:37 PM Joined the server. 14-Mar-20 12:54 PM i'm only getting to about 8 torr with a 2-stage rotary vane (Trivac D2.5E) and all KF flanges + foreline trap. does that sound right? figure i'd be getting at least one or two orders of magnitude lower 14-Mar-20 12:57 PM Probably you have leaks or a pump problem. 14-Mar-20 12:57 PM It is possible that you might have to bake your foreline trap, but even then 8 torr sounds too high 14-Mar-20 12:58 PM Good point about the trap. Try taking that out. Really, try taking everything out, and add back one part at a time. Start with your gauge right on the pump. 14-Mar-20 12:58 PM Using the BPG400 gauge? 14-Mar-20 12:58 PM https://www.lesker.com/newweb/faqs/question.cfm?id=32 14-Mar-20 01:02 PM yeah using BPG400 and MKS901P next to each other for validation (right now using the analog outputs with low precision voltmeters, both report somewhere between 7.5-8torr) 14-Mar-20 01:02 PM It would be a bad idea to put the gauge right on the pump without the foreline trap, the contamination from oil back streaming would greatly reduce the accuracy of the Bayard-Alpert gauge 14-Mar-20 01:02 PM You should use the MKS901P only in the baking process 14-Mar-20 01:03 PM ok 14-Mar-20 01:04 PM But try spraying some alcohol or acetone around your seals to see if there's a spike in pressure 14-Mar-20 01:04 PM does it matter which side of the trap i put the MKS? 14-Mar-20 01:04 PM ahh ok 14-Mar-20 01:06 PM Put the gauge downstream of the trap, so not on the side of the pump 14-Mar-20 01:06 PM With the MKS901P, you can also just take out the trap entirely, pump it down and see if it still gives you 8 Torr 14-Mar-20 01:10 PM ok 14-Mar-20 01:10 PM "A valve should be used to isolate the manifold from the rest of the system during the bakeout cycle" - does that mean I bring the system to vacuum, then engage the valve to cut off the pump from the foreline trap? 14-Mar-20 01:13 PM No, you always connect the pump to the foreline trap during baking so the water vapor will be pumped away after they are baked out. The valve is to protect some sensitive components in your vacuum system from the condensation of gas baked out from your trap. In your case the valve is not necessary 14-Mar-20 01:13 PM ahh 14-Mar-20 01:16 PM It's a good idea to do your leak checking first before investing hours to bake your trap, since a dirty trap alone is unlikely to bring you up to 8 Torr 14-Mar-20 01:19 PM ahh, ok thanks 14-Mar-20 01:19 PM took out the trap and everything after it, now getting 8e-2torr! 14-Mar-20 01:20 PM So your pump is good 14-Mar-20 01:32 PM and ~1.7 torr directly after the trap 14-Mar-20 01:33 PM Wow, yeah sounds like a leaky/extremely dirty trap 14-Mar-20 02:01 PM @samy I've been dosing my chamber with water through a vacuum valve, open to a liquid reservoir, and it doesn't seem to get above 9 torr.. so maybe you're just seeing a ton of water and indeed need that trap baked 14-Mar-20 02:11 PM ahh -- baking now 14-Mar-20 02:57 PM depending on your trap charge you may not be able to bake it in situ (e.g. zeolites need a way higher temp than alumina) 14-Mar-20 02:57 PM taking out the sorbent completely and installing it empty can validate if you've got a leak-leak someplace 14-Mar-20 02:57 PM single-digit torr sounds like a big leak more than saturated sorbent, but idk 14-Mar-20 03:39 PM been baking for an hour or two now, at 14 torr 14-Mar-20 03:56 PM So if I want to ultrasonicate a nickel shim with nano features on it, should I place it up or down side in a beaker in an ultrasonicator... does it matter which direction it's facing Will it still get the sonication action? 14-Mar-20 03:56 PM Placing it down has its " downsides " in that the features will probably be touching the glass at some point 14-Mar-20 05:21 PM anyone cool their rotary vane? i've been running it a few hours and it's ~75C on the outside walls. not seeing anything in the manual about cooling 14-Mar-20 05:23 PM My Trivac D2.5E runs hot as well, but not that hot 14-Mar-20 05:23 PM Oh did you set your gas ballast to position 3 before you started baking? 14-Mar-20 05:40 PM no 0 14-Mar-20 05:40 PM should i set to 3? 14-Mar-20 05:40 PM just changed it to 3 14-Mar-20 05:43 PM You are pumping a lot of water vapor I think, so it's a good idea 14-Mar-20 05:43 PM ah 14-Mar-20 05:43 PM Pretty sure your pump will be switched off when the motor is too hot 14-Mar-20 05:44 PM and if i need to replace oil is generic vacuum pump oil okay? 14-Mar-20 05:46 PM What do you mean by generic vacuum pump oil? Where did you get it, does it have a brand name? 14-Mar-20 05:46 PM https://www.amazon.com/gp/product/B000X1E59S/ 14-Mar-20 05:50 PM Hmm I can't find any data on that... I wouldn't trust genetic HVAC pump oil for your pump if you want a longer life 14-Mar-20 05:50 PM https://www.ebay.com/itm/Oerlikon-Leybold-Vacuum-Leybonol-LVO-210-Oil-Replaces-GS555-HE600-5-liter/303512798479 14-Mar-20 05:50 PM I would be more comfortable swapping oil between lab vacuum pumps since they are ultra refined hydrocarbon oils. But I know that some HVAC pump oil is significantly different from the Leybold oil that it will sort of foam up if you just have a small amount of it mixed into your pump 14-Mar-20 05:55 PM ahh 14-Mar-20 05:55 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200116_080451-E84A0.jpg 14-Mar-20 05:55 PM Here is the result of some yellow jacket pump oil accidentally mixed into my pump 14-Mar-20 06:20 PM to resolve you just empty it out and pour in the new oil or would you need to clean that? 14-Mar-20 06:21 PM There's only a small amount in my pump, I just drained it completely but didn't rebuild or clean inside 14-Mar-20 06:25 PM ah 14-Mar-20 06:39 PM if you are switching oils in any kind of oil sealed pump you generally pour out the old oil, add a new portion of your new oil, run it for short while, then replace that with more of your new oil.. 14-Mar-20 06:39 PM that has been how i always handle compressors too if they need an oil change 14-Mar-20 06:39 PM otherwise you end up with quite a bit of contamination from the old oil and sometimes they foam, sometimes clump, and just all sorts of not good things 14-Mar-20 06:39 PM all depends on what the composition is and any additives 14-Mar-20 08:32 PM i see 15-Mar-20 01:02 AM @Mason_Yu that pump oil looks pretty good compared to the window on my fomblin-oil pump 15-Mar-20 01:02 AM Yeah honestly it was fine 15-Mar-20 01:03 AM I am not sure how long it's been since it was changed, I've been using the pump for a good 9 months every so often and bought it 2 years before that 15-Mar-20 01:03 AM But it started running a bit hotter than before and started shutting down when it was backing a turbo 15-Mar-20 01:03 AM Ah 15-Mar-20 01:03 AM So just did an oil change using some Welch pump oil for now, runs fantastic 15-Mar-20 01:04 AM That would be pretty bad, since mine is hooked to my FIB... Which probably monitors for events like that and I'd assume has some isolation valve and shuts down the turbo 15-Mar-20 01:04 AM If i can get this dry scroll pump fixed up, I'll probably just switch to that 15-Mar-20 01:04 AM Since I'm not using anything corrosive in my FIB, yet 15-Mar-20 01:04 AM (or in the near to mid term future) 15-Mar-20 01:06 AM Were you able to clean up your tip seals? 15-Mar-20 01:06 AM I ordered a whetstone today from Amazon 15-Mar-20 01:06 AM 3000-4000 and 8000-10000 grit ratings 15-Mar-20 01:06 AM The one at harbor freight seemed like in the 120 to 200 range 15-Mar-20 01:06 AM My goofing off today/tonight was microwaving matches in an upside down beaker 15-Mar-20 01:06 AM To try and spark the plasma that nile red was recently reporting on 15-Mar-20 01:06 AM Turns out pre-charred wood works really well for this, but also causes a bit of a campfire smell in the room 15-Mar-20 01:06 AM I definitely was pretty satisfied with seeing a big plasma ball 15-Mar-20 10:55 AM i see the TMP has a vent port adaptor -- if i want to fill my chamber with an inert gas, is it okay to use the vent port adaptor or should i connect directly to the chamber? 15-Mar-20 10:55 AM also i think as i didn't have gas ballast open during baking my mech pump oil has a bunch of water in it :\ is it okay to use some non-standard oil with it for a few runs before new correct oil arrives? or can i run with the bad oil in there for a little? 15-Mar-20 11:10 AM also here's an example diagram from EXT255H manual - #6 is a backing valve but under what condition would you use that? 15-Mar-20 11:10 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_2020-03-15_11.10.03-6B24B.png 15-Mar-20 11:10 AM Lots of us vent the chamber to atmosphere from behind the turbo. It’s wrong but fine, in all cases I’ve seen 15-Mar-20 11:10 AM All our “vent” ports are plugged 15-Mar-20 11:46 AM About to turn on the big turbo for the first time.. 15-Mar-20 11:56 AM lol went from -2 to -6 torr in about a minute 15-Mar-20 12:20 PM nice 15-Mar-20 12:20 PM what pump? 15-Mar-20 12:24 PM leybold 2200 iPL 15-Mar-20 12:24 PM we have had it since last spring but were sidetracked. Installed it in september, got sidetracked again, and only just got ready to use it 15-Mar-20 01:14 PM @samy The backing valve is used in the same kind of situations like your bake out of the foreline trap, when you don't want to have large amount of back streaming gas into your chamber, or completely vent the chamber through the pump. 15-Mar-20 01:14 PM As far as water in the oil goes, can you see any foaming or color changes through the window? If not, it should be good if you're just running it for a few days 15-Mar-20 01:30 PM it looks like the pic you sent, foamy ish 15-Mar-20 01:30 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_8980-22796.JPG 15-Mar-20 01:59 PM That's pretty bad, since your pump is running so hot already, probably best to wait for the new oil 15-Mar-20 03:51 PM it's running at 50C right now (running for the past few hours), that pic is after i emptied half the oil out as it was near the max line before 15-Mar-20 03:52 PM 50C seems about all I've ever seen from rotary vanes 15-Mar-20 03:52 PM hot, but not hot hot 15-Mar-20 03:53 PM it was 75C yesterday but the oil was at the max line (I think it was half originally but assuming the water during bake out got into the oil as i didn't have gas ballast open) 15-Mar-20 03:53 PM @Mason_Yu you note "The backing valve is used in the same kind of situations like your bake out of the foreline trap" - should i have used the valve at some point during the bake out? 15-Mar-20 03:55 PM Not really necessary since your process has nothing sensitive to small amounts of water vapor or impurity in your chamber 15-Mar-20 03:56 PM k 15-Mar-20 03:56 PM but a larger chamber, would you bring it to vacuum, close the valve to the pump, then bake? 15-Mar-20 03:57 PM @samy with all the water, you risk rusting things in your pump 15-Mar-20 03:57 PM You could drain it, heat it on the stove to dry it, reinstall it 15-Mar-20 03:57 PM drain it as in the oil? 15-Mar-20 03:57 PM Yeah 15-Mar-20 03:57 PM You already ordered new oil right? Best to just wait 15-Mar-20 03:57 PM After draining the old oil out 15-Mar-20 03:58 PM i'm attempting freeze drying ice cream right now...so any suggestions on cleaning out or improving the pump after are encouraged 15-Mar-20 03:58 PM with the foreline trap + cold trap between the ice cream and pump 15-Mar-20 04:00 PM Hmm, do you have another pump (like a HVAC pump) for this? I think you might be running close to if not above the maximum rated tolerance to water vapor for your pump even if the gas ballast is set to position 3 15-Mar-20 04:06 PM i have a single stage pump but don't think that will get to pressure 15-Mar-20 04:14 PM If you are not planning on running it for a long time then go for it, hope you've got a good cold trap. It is useful to put an isolation valve right before your foreline trap in this application, so you can close the valve after freeze drying, and continue to operate the pump with gas ballast open for a few minutes. This heats up the oil internally and cause the water to vaporize, at least partially 15-Mar-20 04:15 PM interesting 15-Mar-20 04:15 PM It's a bad idea in general to run your pump with the gas ballast fully open all the time though 15-Mar-20 04:15 PM Only in special cases, and you should have an exhaust filter when you do this 15-Mar-20 04:15 PM and if i am running with too much water vapor, that's because internal things may rust? can i tear it down and clean it out after? 15-Mar-20 04:15 PM exhaust filter like an oil mist filter? (I'm using a roll of TP atm) 15-Mar-20 04:16 PM Water is incompressible, so you might cause mechanical damage before rusting 15-Mar-20 04:16 PM It can be expensive to rebuild your pump, so preventative maintenance is always better than fixing things later 15-Mar-20 04:16 PM Hope you've got your TP stocked up lol. If you can't see a cloud of mist from your exhaust when you put a backlight to it in a dark room, it's probably fine. Check your oil level often if you open your gas ballast a lot 15-Mar-20 04:19 PM haha 15-Mar-20 04:19 PM ok thanks 15-Mar-20 04:19 PM could i put dry ice inside the cold trap? since it will only sublimate to CO2 and likely exhaust through the pump fine? 15-Mar-20 04:24 PM again - the people I know with rotary vane pumps are super careless and don't really think about any of this. None of them use it to back a turbo or diff pump, though. 15-Mar-20 04:25 PM would that improve my cold trap? since right now i'm using dry ice + alcohol on the outside of the cold trap 15-Mar-20 04:25 PM I'm more careful about my equipment since I can't just buy a new one if my current one fails 15-Mar-20 04:25 PM ^ 15-Mar-20 04:25 PM The dry ice would completely sublimate and you would never reach the vacuum you need to freeze dry in your chamber after the cold trap 15-Mar-20 04:25 PM Before the dry ice is gone 15-Mar-20 04:26 PM Doing things properly is great. Just don't be too terrified. Although rotary vane pumps are probably the easiest piece of vacuum hardware to acquire free, specifically the lower pumping speed 3 phase ones 15-Mar-20 04:26 PM i see 15-Mar-20 04:26 PM nobody wants a low pumping speed 3 phase oil pump 15-Mar-20 04:27 PM i'm comfortable breaking things as will be a good chance to learn how to fix it...as long as it's broken in a way i can actually fix it :\ 15-Mar-20 04:27 PM 3 phase as in power? 15-Mar-20 04:28 PM I just haven't actually heard of them breaking 15-Mar-20 04:28 PM Yeah 15-Mar-20 04:28 PM these: https://www.idealvac.com/Edwards-40-E2M40-Rotary-Vane-Dual-Stage-Mechanical-Vacuum-Pump-Rebuilt-Refurbished/pp/P10843 15-Mar-20 04:29 PM I'd grab one if they're free and close by 15-Mar-20 04:30 PM haha same 15-Mar-20 04:30 PM I think within our basement we have seven rotary vane pumps not in use? gave away an edwards 80 and some little alcatel thing last year. 15-Mar-20 04:30 PM still have an 80 with a booster in a closet beside a diff pump, just in case someone in the department wants it... But the others are probably up for grabs ish 15-Mar-20 04:30 PM even for us who have tons of 3 phase sockets, oil is just not the 21st century way 15-Mar-20 04:35 PM With all classes moved to online and all students being told to go back home till the end of the semester, I should have free reign over all the tech dumps in the next few months 15-Mar-20 04:35 PM Hopefully will get some good stuff, eyeing a belt drive Welch pump already 15-Mar-20 04:37 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/2Q-79414.png 15-Mar-20 04:37 PM you mean these? 15-Mar-20 04:37 PM Yeah, a bit older, but yes 15-Mar-20 04:37 PM lol 15-Mar-20 04:37 PM Super quiet 15-Mar-20 04:37 PM I have seen three of those today 15-Mar-20 04:37 PM sitting in halways 15-Mar-20 04:37 PM ready to be taken to waste 15-Mar-20 04:37 PM Such a shame... 15-Mar-20 04:38 PM if you get one, make a vibration isolation panel 15-Mar-20 04:38 PM they wiggle so much 15-Mar-20 04:38 PM quiet but wiggly, counterintuitive 15-Mar-20 04:38 PM Pretty sure it's mounted on one already 15-Mar-20 04:39 PM I wish instead of a bunch of makerspace type things made by each department independently 15-Mar-20 04:39 PM some space was allocated for students to borrow equipment and try self directed research stuff like you guys do 15-Mar-20 04:39 PM like how many rooms with rows of 3D printers do we really need? 15-Mar-20 04:39 PM and how many closets full of 20-50 year old lab equipment that will sit there until someone replaces their current setup and needs the storage space and junks the old stuff 15-Mar-20 04:44 PM Yeah... There are quite a few people doing research on their own here, and they grab a lot of equipment from tech dumps, but most of it happens underground. Part of it is due to the IP policy of the school, and part of it is just how easy it is for people to hijack makerspaces and turn them into 3D print farms 15-Mar-20 04:44 PM A makerspace I started with a few buddies has suffered that unfortunate fate, and currently owns 36 3D printers, almost all of which sit idle until the end of the semester when people realize they're forced to 3D print stuff for class projects or presentations 15-Mar-20 04:44 PM They don't even repair the printers themselves anymore 15-Mar-20 04:44 PM Just hired a guy to do it for them 15-Mar-20 04:44 PM When we started, I thought we could at least teach people how to build their own cheap printers and basic machining and fabrication techniques, even tried to do a few TIG welding workshops. But no, can't get funding if you want to build your own custom printer 15-Mar-20 04:44 PM That's when I realized it's better to just do it yourself underground 15-Mar-20 04:50 PM funding is pretty messed up for sure 15-Mar-20 04:50 PM and the variation in how some technical skills are profitable while others are almost like party tricks 15-Mar-20 04:52 PM A lot of classes are teaching party tricks if you put it that way 15-Mar-20 04:52 PM I mostly just wish there was a way to efficiently recycle equipment, and more efficient use of space than using good lab space for storage 15-Mar-20 04:52 PM University could have a warehouse or something. 15-Mar-20 04:53 PM It will get filled so quickly, and mostly with useless stuff 15-Mar-20 04:53 PM The funding system does not encourage hoarding or reuse 15-Mar-20 04:53 PM Or repair for that matter 15-Mar-20 04:54 PM it does encourage hoarding 15-Mar-20 04:54 PM because you never know when the grant you want won't come 15-Mar-20 04:54 PM there's a lot of "reuse" pressure right before a big grant gets approved, when you're running out of the previous one 15-Mar-20 04:54 PM the groups that pay for a research tech do all this so much better 15-Mar-20 04:56 PM It depends on the department I guess... I've certainly seen groups that are very good at doing it and making the most out of what they already have, but they are not the ones the university wants to highlight 15-Mar-20 04:56 PM because they're more technically minded and see a bunch of mildly broken turbopumps and actually think of sending them in for quotes / repair / servicing etc... 15-Mar-20 04:56 PM while those without are just "broken? if we have money, buy a new one" 15-Mar-20 04:56 PM "it's an investment" 15-Mar-20 05:05 PM fwiw everyone here hoards like hell 15-Mar-20 05:05 PM Whenever you have significant amounts of extra money you buy misc things like lasers and pumps to hopefully eventually get a new experiment up and running 15-Mar-20 05:05 PM But the sheer amount of 80s and before tech we have sitting unused is staggering 15-Mar-20 05:11 PM Yeah... Ugh. 15-Mar-20 09:56 PM @Mason_Yu you said "It is useful to put an isolation valve right before your foreline trap in this application, so you can close the valve after freeze drying, and continue to operate the pump with gas ballast open for a few minutes" - when you say before the foreline trap, you mean put the valve between the pump and foreline trap, right? 15-Mar-20 09:58 PM I meant between the foreline trap and the rest of your system, but it doesn't make a huge difference 15-Mar-20 09:58 PM Just like what's shown in the system layout diagram you posted 15-Mar-20 10:07 PM Cool 15-Mar-20 10:19 PM Joined the server. 17-Mar-20 08:47 PM @samy? What vac level did you get to after baking? 17-Mar-20 08:49 PM 300mtorr 17-Mar-20 08:49 PM which was great...was able to half-way freeze dry some ben & jerrys half baked. need to improve the process 17-Mar-20 08:49 PM and turned out way tastier than i expected 17-Mar-20 09:23 PM What happened that it only half way worked? 17-Mar-20 09:23 PM Sounds great though! 17-Mar-20 10:16 PM swapped out the MAX3232 chips on the ttl-rs232 adapters i got from ebay and they work perfectly now 17-Mar-20 10:16 PM haven't tried decapping any of the fakes yet but that might be amusing 17-Mar-20 10:32 PM @nmz787 it didn't remove water from the inside, just the outside 18-Mar-20 05:03 AM ... i have never considered freeze-drying ice cream until now 18-Mar-20 05:03 AM this changes Everything 18-Mar-20 05:03 AM astronaut icecream! 18-Mar-20 05:04 AM it's SO GOOD 18-Mar-20 05:04 AM and needlessly expensive 18-Mar-20 05:04 AM I have actually never tried it 18-Mar-20 05:05 AM recommended! 18-Mar-20 05:06 AM when I was 12 or 13 I was in new york and bought some at the museum of science and technology and never dared to eat it, as it was the only souvenir I got XD 18-Mar-20 05:06 AM and then I lost it one day 18-Mar-20 05:06 AM I should make some myself 18-Mar-20 10:19 AM Astronaut ice cream, fried spamwich, and a big ol' glass of Tang. That's a meal I called my Space Coast Kid's Delight. 18-Mar-20 11:33 AM We are still open. Our products are critical in water treatment and waste treatment and even though we have only received 3 calls and done one shipment we are here. I would rather they just send everybody else home and I could just handle emergency shipments and service calls but honestly I’m just roaming around fixing nuisance things and watching you tube videos. 18-Mar-20 11:34 AM I'm baking bread while documenting my apparatus 18-Mar-20 11:58 AM i've been working from home for .. going on three weeks now, serving some vaguely critical role. oddly things are getting more intense as people start hunkering down for maximal resilience (which is, of course, shaking out all the issues and BREAKING EVERYTHING) 18-Mar-20 11:58 AM 18-Mar-20 12:52 PM Woo! 18-Mar-20 01:49 PM Lol, I've been working from home like90% for almost 2 years so this time period doesn't feel much different for me 18-Mar-20 02:16 PM i'm noticing i'm not able to get to decent vacuum anymore with the foreline trap so i tried just a T (one side blocked) and MKS901P on pump, got down to 300mtorr which was good, but then after turning off the pump within 10 seconds i was nearly back to atmosphere without opening anything up (~600 torr), is that normal or is that sign of a leak? 18-Mar-20 02:18 PM leak 18-Mar-20 02:18 PM wait, did you not have a valve between the pump and the tee? 18-Mar-20 02:27 PM don't trust a non-running pump to retain any kind of vacuum 18-Mar-20 02:27 PM you're relying on your anti-suckback valve to not instantly snort all of your pump oil up into your vacuum chamber -- cheap HVAC pumps may not even have an anti-suckback valve 18-Mar-20 02:36 PM e.g. my foreline is like: pump -> valve (foreline) -> foreline trap -> kf cross -> (vacuum gauge, two more valves; one to turbo, one for misc roughing purposes) 18-Mar-20 02:36 PM everything starts closed, pump gets turned on and is left to warm up for a bit (with gas ballast open, if you have one) before the first foreline valve gets opened.. then i can check pressure, and open up the turbo/etc when i'm at a good safe point to do so. that way i can be sure that there's not something wildly awry with my pump or trap before i open it to my chamber(s) 18-Mar-20 02:38 PM Yeah AFAIK no pumps actually hold vacuum when off? 18-Mar-20 02:38 PM that foreline valve gets closed before the pump turns off, always 18-Mar-20 02:38 PM if you pump the inlet of a scroll with another scroll, you make it spin backwards 18-Mar-20 02:38 PM don't do that 18-Mar-20 02:39 PM mine holds a tiny bit of vacuum if i shut it off with the gas ballast closed up, enough that it'll go pop or whoosh if i take off my foreline/crack the ballast 18-Mar-20 02:39 PM but it's like hundreds of torr 18-Mar-20 02:39 PM enough to make the pump harder to start, not enough to do anything useful :D 18-Mar-20 02:42 PM The pump I've been using for deposition stuff holds pretty well when off 18-Mar-20 02:43 PM to that end, i've actually seen fast solenoid foreline valves meant to be wired straight into the pump's electrical circuit via some means or another, so if the power goes out on e.g. just the pump while the rest of your valves are still open, you don't snort a liter of oil back up into everything 18-Mar-20 02:43 PM I added an isolation valve recently tho to be sure and to prevent backstreaming and pumping away my reactants while they're reacting 18-Mar-20 02:43 PM Yeah all our scrolls have those @qualia 18-Mar-20 02:43 PM Or rather, had. We removed some 18-Mar-20 02:44 PM you're gonna get scroll fluid EVERYWHERE 18-Mar-20 02:44 PM They were hardwired with the motors, but we didn't want the valve to immediately open after the power comes back on 18-Mar-20 02:44 PM so we replaced them with pneumatics on a latching relay 18-Mar-20 02:44 PM ah, sensible 18-Mar-20 02:45 PM Heh "scroll fluid" 18-Mar-20 02:45 PM That doesn't actually exist, right? 18-Mar-20 02:47 PM it's a low-volatility fluoropolymer headlamp fluid 18-Mar-20 02:47 PM (no :D) 18-Mar-20 03:01 PM @idmb no i removed the valve 18-Mar-20 03:35 PM Ok well there’s your problem 18-Mar-20 04:30 PM when should i be using it? 18-Mar-20 04:30 PM or any good docs on when to turn it on/off? 18-Mar-20 04:30 PM reading this - it mentions valve closed on startup until certain pressure, so it's okay to have a tee+pressure sensor before the valve so i can measure while the valve is closed? http://www.hyvac.com/tech_support/pump_startup%202.htm 18-Mar-20 04:46 PM I would just always have the valve closed for at least the first 10 sec of turn-on and then closed right before turning it off, always. 18-Mar-20 04:50 PM ok 18-Mar-20 04:51 PM all of our oil pumps have one of our "vintage" kf valves attached directly to them 18-Mar-20 04:51 PM but yeah don't expect the rotary seals to not leak when they're not spinning 18-Mar-20 04:53 PM Actually, my D2.5E holds a pretty good vacuum right after switching off, like rising slowly to ~20 mTorr after a few minutes 18-Mar-20 04:53 PM But yeah it's a bad idea to hold vacuum using the rotary seals long term 18-Mar-20 04:54 PM nvm 18-Mar-20 04:54 PM mTorr 18-Mar-20 04:54 PM Did you have your gas ballast open @samy ? 18-Mar-20 04:55 PM @Mason_Yu no, i was surprised cause usually i think it holds vacuum after turning off (though i usually bring it to atmosphere after turning off) 18-Mar-20 04:55 PM it has a "small" leak 18-Mar-20 04:56 PM Yeah, any small leak will do it, and it's not a reliable seal because it needs oil to achieve it, which of course drips out after the pump is off 18-Mar-20 04:56 PM So no cause for concern if it still holds good vacuum while running 18-Mar-20 04:59 PM okay cool, thanks 18-Mar-20 06:18 PM Joined the server. 18-Mar-20 06:18 PM sup @qualia i fixed my discord issues 18-Mar-20 06:24 PM oh hey you made it :D 18-Mar-20 08:03 PM I wish more people filled in the #introductions_and_directory section 18-Mar-20 08:05 PM At least digshadow uses that handle consistently across platforms 18-Mar-20 11:10 PM This is more general than #radiation specific so I guess I will ask here. If I want to fill some small tubes with a gas mix + a small amount of a halogen are there any options for protecting the pump from those vapors? 18-Mar-20 11:10 PM Will probably be at something like 100-400 Torr for the final pressure goal but evacuating as much as possible beforehand would be ideal 18-Mar-20 11:10 PM Ne+Br, Ar+Br, and Ne+Ar+Br are the three gas mixes I am looking at 19-Mar-20 08:11 AM You can pump a buffer chamber. 19-Mar-20 08:26 PM @idmb maybe I just don't want the villagers to find me as easily 19-Mar-20 08:35 PM Well you were already criticized heavily from the whole beryllium at the diner thing, so not like people haven't already been pre introduced 19-Mar-20 08:58 PM Why hello. 20-Mar-20 12:28 PM Joined the server. 20-Mar-20 01:11 PM See what you made me do qualia? Next week quarantine is going to be just me sitting in the middle of 5 different chat apps pretending to be some sort of evil mastermind. 20-Mar-20 01:13 PM >:D 20-Mar-20 01:13 PM i mean, certainly a good time for it 20-Mar-20 01:19 PM It is totally. We are now doing shifts at work so I got to do all the wrenching this week and no-one was there to mess with me which was a nice change of pace. 21-Mar-20 12:05 AM welp after 20 hour bakeout of trivac, i had decent pressure...but after another run, i can't get any decent vacuum, even with pressure gauge directly on inlet. the leybold oil i got got damaged in transit so never made it to me so i swapped out with some other high vacuum oil and still no improvement (granted the old oil was nasty). lots of burnt material in the system from the bakeout i suppose 21-Mar-20 12:05 AM think i should just take it entirely apart and try to clean it up and look for anything wrong 21-Mar-20 12:05 AM also after going through manual realized mine didn't come with a dirt trap so possibly burnt zeolite or contaminants got in there 21-Mar-20 02:08 AM What vac are you getting now directly on the inlet? 21-Mar-20 02:08 AM And a run in your case was again ice cream? 21-Mar-20 09:00 AM ~70 torr 21-Mar-20 09:00 AM everything is pretty dirty after the bakeout, granted it was with a used foreline trap i got from ebay 21-Mar-20 09:00 AM after the freeze drying once i did a bake out and got to ~300mtorr, and i hadn't done it again, but it progressively got worse next time i started pulling vacuum, not sure why, i haven't done anything in between 21-Mar-20 01:55 PM Sounds like the foreline trap might be collecting water 21-Mar-20 01:55 PM Which you don't want , right? You want it for catching pump oil 21-Mar-20 01:55 PM Seems like a cold trap would solve your issues and be more maintainable, but maybe I'm mistaken 21-Mar-20 02:06 PM i used a (home built) cold trap 21-Mar-20 02:06 PM i used the foreline trap as a backup to that 21-Mar-20 02:13 PM And the homebuilt is closer to the ice cream, right? 21-Mar-20 02:13 PM Did you rig up an air conditioner cold coil? 21-Mar-20 02:13 PM It needs to be very cold, less than tap water or fridge cold 21-Mar-20 02:13 PM Or did you just use some sort of double-boiler ice bath? 21-Mar-20 02:23 PM chamber with ice cream -> chamber surrounded by dry ice + alcohol bath -> foreline trap -> pump 21-Mar-20 02:23 PM based mostly off Thought Emporium's youtube vid on it 21-Mar-20 02:23 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_8988-AD60B.JPG 21-Mar-20 02:27 PM Whats the black barb fitting hose to? 21-Mar-20 02:27 PM That seems leak prone 21-Mar-20 02:27 PM At least throw a hose clamp on that 21-Mar-20 02:27 PM left side (KF bellow) was to foreline trap - dry ice block also underneath the bucket the chamber is in, the bucket filled with dry ice + alcohol, and i had that covered most of the time with styrofoam 21-Mar-20 02:27 PM the black hose to the ice cream chamber 21-Mar-20 02:27 PM it was decent, the MKS at top shows 5.22V (166mtorr) 21-Mar-20 02:29 PM Have you tested this whole rig without any wet stuff (milk) inside to see what it gets to by itself? 21-Mar-20 02:29 PM Seems like you might just have some bad leaks for one thing 21-Mar-20 02:29 PM got lazy and drilled and epoxied a barb to the acrylic top (Loctite EA 1C) 21-Mar-20 02:30 PM As long as the threads were coated in the epoxy, i think thats probably OK 21-Mar-20 02:30 PM I did similar for my pvc chamber 21-Mar-20 02:30 PM To add a kf port 21-Mar-20 02:31 PM ahh 21-Mar-20 02:31 PM Although I'm also getting only to about 150mTorr... I think that might be due to my belljar sealing edge being rough 21-Mar-20 02:31 PM well the primary issue is the pump by itself can't get anywhere close to what it used to 21-Mar-20 02:31 PM Hmm 21-Mar-20 02:31 PM Yeah maybe too much water, or that oil you used is just wrong viscosity 21-Mar-20 02:31 PM I'm no expert here 21-Mar-20 02:32 PM after the bake out there's soot all over the insides of the KF bellows/tees and after reading the trivac manual I realized mine didn't come with a dust stopper in the inlet so i'm thinking a bunch of crap got into the pump 21-Mar-20 02:32 PM yeah might be. ordered new oil a week ago but it got damaged in transit granted i was using the original oil which was working fine, it all went down hill after 20 hour bakout 21-Mar-20 02:32 PM it was actually good after the bakeout, probably got to 300mtorr, and i hadn't run anything else through it and it started getting worse as i attempted to find what i thought was a leak 21-Mar-20 02:32 PM i just emptied the oil so i'm gonna try tearing it down and see what's inside...hope i can put it back together 21-Mar-20 02:32 PM i was also sputtering and doing titanium sublimation so possible some of that burnt stuff got in there as well 21-Mar-20 02:42 PM How did you do your bake out of the foreline trap? 21-Mar-20 02:42 PM Using heating bands? 21-Mar-20 02:44 PM it has an internal heater 21-Mar-20 02:45 PM Oh, and what pump oil did you use in place of the original? 21-Mar-20 02:45 PM i can open it up to see what...i also wonder if the zeolite just had a lot of bad stuff as it was just a used trap i got on ebay 21-Mar-20 02:45 PM Did you solvent rinse the trap first? 21-Mar-20 02:45 PM Before baking? 21-Mar-20 02:45 PM I wouldn't expect to see black dust, maybe you overheated? 21-Mar-20 02:46 PM well i was still using the original yesterday but it wouldn't get down past ~70torr with just a sensor directly on valve/inlet so i used some other generic high vacuum pump oil 21-Mar-20 02:47 PM (I've never done this nor really read about it, just my kneejerk expectations) 21-Mar-20 02:47 PM maybe? i just read online to do 12-20 hours, so i did 20 hours 21-Mar-20 02:47 PM Solvent washed it first? 21-Mar-20 02:47 PM no 21-Mar-20 02:47 PM Hmm 21-Mar-20 02:47 PM I've never had to bake my traps for that long 21-Mar-20 02:47 PM 4 hours I think was the longest I've ever done 21-Mar-20 02:48 PM How are your orings looking? Burn them? 21-Mar-20 02:48 PM ok, i was just being extra careful in case there was a lot of water in there not caught by the cold trap 21-Mar-20 02:48 PM no don't think any of those are burnt 21-Mar-20 02:48 PM You had the gauges disconnected during that time right? 21-Mar-20 02:48 PM And did you run the pump with gas ballast fully open during the 20 hours? 21-Mar-20 02:49 PM only the foreline trap was being baked, do people bake other things? i had the MKS901P connected after a bellow hose 21-Mar-20 02:49 PM yeah 21-Mar-20 02:50 PM Oh, that would heat up your pump by a lot... It should be within design limits but should not be done often, since oil degradation is greatly accelerated 21-Mar-20 02:50 PM Part of the reason why I only ever did short bakeouts 21-Mar-20 02:50 PM 901p manual says "Bake out The transducer electronics can withstand 85 oC (185 o F) when the power is turned off" 21-Mar-20 02:51 PM The electronics are not heated at all 21-Mar-20 02:51 PM i doubt it got that hot at the MKS 21-Mar-20 02:51 PM Well if the bellow conducts well enough 21-Mar-20 02:51 PM the bellows weren't very warm 21-Mar-20 02:51 PM Mmm 21-Mar-20 02:51 PM the trap itself was hot though 21-Mar-20 02:52 PM Definitely would recommend looking at the zeolite now if you have access to it 21-Mar-20 02:52 PM Did you visually inspect the o-rings on the trap attachments? 21-Mar-20 02:52 PM If they're kf, that's a quick check 21-Mar-20 02:52 PM k 21-Mar-20 03:01 PM A picture of the oil through the side window would also be nice to have 21-Mar-20 03:10 PM @Applied_Ion in a inductively coupled plasma chamber, what does the input wattage change? 21-Mar-20 03:10 PM Like, why would i need more Watts, how would i come to such a conclusion? 21-Mar-20 03:27 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_9016-61E70.JPG 21-Mar-20 03:27 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_9018-DDA62.JPG 21-Mar-20 03:33 PM Is this the new oil you put into the pump after baking out? The Robinair generic pump oil? Or is this the oil that came with your pump? 21-Mar-20 03:33 PM When compared with the first picture you sent, it looks like there are relatively clear droplets condensing on top of the window, which might be water 21-Mar-20 03:33 PM If so, this amount of water in the pump is not good news at all, you might see significant corrosion 21-Mar-20 03:47 PM our pumps look lke they have canola in them 21-Mar-20 03:47 PM nothing that sludgey 21-Mar-20 03:48 PM Here's my D10E oil, should be really clear 21-Mar-20 03:48 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20200321_184831-D1894.jpg 21-Mar-20 03:52 PM for reference: This is not what it should look like https://www.youtube.com/watch?v=IUrEdExiwko 21-Mar-20 03:58 PM yeah 21-Mar-20 04:09 PM the pic of the trivac is weird because i've already emptied all the oil so that is just old residue -- the oil is in pic below and i put it on my finger, it's pretty clear (now that i've replaced the old stuff) 21-Mar-20 04:13 PM The oil you emptied out in the oil pan was the old oil? Or the new stuff you put in? 21-Mar-20 04:16 PM it's important to make sure if the dark discoloration is rust or organics 21-Mar-20 04:18 PM I certainly don't see an oil line in the first pic, was it running when you took that pic? 21-Mar-20 04:18 PM Strange an Amazon delivery driver just knocked on my door to hand me a package 21-Mar-20 04:18 PM Like, how is that sensible in this pandemic climate? 21-Mar-20 04:21 PM amazon warehouses are still super busy 21-Mar-20 04:21 PM I know at least two people who are buying as much stuff they think they might need in the next few months from amazon 21-Mar-20 04:21 PM in case amazon gets shut down 21-Mar-20 04:25 PM It was just a tiny packet (inside a huge packet) 21-Mar-20 04:25 PM Rotary grinding wheels 21-Mar-20 04:25 PM For trying to resurface that scroll pump 21-Mar-20 04:25 PM Like $6 value 21-Mar-20 05:34 PM @Mason_Yu it's the new oil (i put it on my finger so you could see it's not as dark as it looks as it's in a black container) 21-Mar-20 05:34 PM The Robinair generic pump oil? 21-Mar-20 05:35 PM yeah - i took a little of the old oil out and it was pretty bad 21-Mar-20 05:37 PM Using the Robinair oil might have been a bad idea 21-Mar-20 05:37 PM perhaps 21-Mar-20 05:38 PM https://www.robinair.com/sites/default/files/17-17_vacuum_pump_oil.pdf 21-Mar-20 05:38 PM i mean, i'm sure it's not a good idea 21-Mar-20 05:38 PM It's viscosity is about 3 times lower than the Leybold LVO210 21-Mar-20 05:38 PM ahh 21-Mar-20 05:39 PM At lower temperatures 21-Mar-20 05:39 PM At this point, if you want to open up the pump case and clean the oil sump, be careful not to damage the seal on the case, it's a strange o-ring thing and will be expensive to replace 21-Mar-20 05:39 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-AA873.png 21-Mar-20 05:42 PM ok, thanks! i will do that 21-Mar-20 05:42 PM i was looking at intake dirt filters and it's ~$75 on ebay 21-Mar-20 05:42 PM for a metal mesh...will try to make one i suppose 21-Mar-20 05:45 PM https://www.ldsvacuumshopper.com/nwri2.html 21-Mar-20 05:45 PM $20 for a mesh centering ring a a bit cheaper, certainly will help to protect your pump a lot 21-Mar-20 05:45 PM https://mackvacuum.com/index.php/leybold-vacuum-pump-parts/trivac-e-series/d2-5e-pump-leybold/product/2325-kit-minor-d2-5e 21-Mar-20 05:45 PM https://mackvacuum.com/index.php/leybold-vacuum-pump-parts/trivac-e-series/d2-5e-pump-leybold/product/2324-kit-vane-gx-d2-5e 21-Mar-20 05:45 PM If you want to do a full rebuild, you can get the vanes from the second link and replace any damaged viton o-rings from https://www.theoringstore.com/ yourself instead of getting them as a kit. Unfortunately none of this is super cheap 21-Mar-20 05:45 PM @Conmega has quite a bit of experience with rebuilding pumps and might be able to help you 21-Mar-20 06:01 PM If you just get a full rebuild kit it will come with everything you need... no need to buy rings seperately 21-Mar-20 06:01 PM which honestly the vanes are the majority of the cost of a rebuild kit 21-Mar-20 06:01 PM so yea... just get a major rebuild kit 21-Mar-20 06:01 PM a minor rebuild kit is what you get if you don't need vanes but need seals 21-Mar-20 06:03 PM https://mackvacuum.com/index.php/leybold-vacuum-pump-parts/trivac-e-series/d2-5e-pump-leybold/product/2322-kit-major-d2-5e-gx 21-Mar-20 06:03 PM It's like $500 for a major kit... 21-Mar-20 06:03 PM At that point might as well just get another pump 21-Mar-20 06:07 PM Well and that's the case sometimes for some of these pumps... That seems extremely high though 21-Mar-20 06:07 PM Ah I see there is a LOT included in that major rebuild kit 21-Mar-20 06:07 PM a lot more than I am used to seeing... 21-Mar-20 06:07 PM But yes, vacuum pumps cost a lot... its kinda how it is, but you can just "get another pump" but if its another used pump at 100 bucks say for example then you find out it also needs a rebuild... you've now outed yourself another 100 bucks and not gotten any close to pulling vacuum. 21-Mar-20 06:07 PM Its one of those things I just recommend saving up for, getting it over with, then you have a good pump that should last you well... probably until the seals fail again unless your going to run it 24/7 21-Mar-20 06:07 PM so yea probably a good 4-5 years or so at-least lol 21-Mar-20 06:07 PM but generally, most vacuum pumps I see anyway, minor rebuild is around 100~150 dollars, major is 200-300 21-Mar-20 06:12 PM https://www.sisweb.com/vacuum/precision/leybold.htm 21-Mar-20 06:12 PM Also its 413 dollars at VPS 21-Mar-20 06:12 PM https://www.vacuumpumpsupply.com/leybold-100000347kit-kit-major-d2-5e-g11-e2-series/ 21-Mar-20 06:12 PM Prices here are cheaper, but nothing is stocked 21-Mar-20 06:12 PM you absolutely must shop around for vacuum parts honestly 21-Mar-20 06:12 PM prices are different anywhere from a few bucks to hundreds... 21-Mar-20 06:12 PM this is an industry where well... you can kinda almost charge whatever you want to most customers 21-Mar-20 06:12 PM we are not most customers 21-Mar-20 06:12 PM but yea, if you get a roughing pump and it looks SUPER SUPER beat maybe don't rebuild that guy, but if you get a pump that seems overall OK and it doesn't look like its been destroyed with running corrosive stuff through it or something crazy, its really worth the investment to get it rebuilt 21-Mar-20 06:14 PM https://www.ebay.com/itm/Leybold-Complete-Kit-for-TRIVAC-E-D1-2E-D2-5E-Leybold-D2-5E-Kit-PN-20040026/333096007992 21-Mar-20 06:14 PM buying used pumps is like playing the lottery unless you really know where its coming from 21-Mar-20 06:14 PM awesome, thanks for the links/info guys, this is great 21-Mar-20 06:14 PM hopefully i can tell what's wrong when i open it up 21-Mar-20 06:14 PM oh that's fantastic, ebay comes to save the day again lol 21-Mar-20 06:14 PM guess china has started realizing they can make tons of money undercutting 21-Mar-20 06:15 PM Look at that rusted thing 21-Mar-20 06:15 PM @Mason_Yu ?? 21-Mar-20 06:15 PM https://www.ajvs.com/new/product_info.php?products_id=11794 21-Mar-20 06:15 PM you mean that rust colored thing? 21-Mar-20 06:15 PM https://www.ajvs.com/redirect/5/Leybold_D_25_E_Major_Repair_Kit_PN11794_1_wm,3b4cf2d92d696ee028f9145cb9e96129 21-Mar-20 06:15 PM that ^ 21-Mar-20 06:16 PM Oh it's the oil mist separater 21-Mar-20 06:16 PM yea... was going to say that's how it should be lol 21-Mar-20 06:16 PM I may have to nab one of those kits though... I think I have one D2.5E??? 21-Mar-20 06:16 PM I thought it was like part of a valve or something 21-Mar-20 06:17 PM maybe I have to dig down in my pile o pumps and finish rebuilding that one... 21-Mar-20 06:17 PM life keeps getting in the way... been spending time with a friend this weekend cleaning out the basement though 21-Mar-20 06:17 PM have almost doubled the floor space with re-packing/organizing moving stuff 21-Mar-20 06:17 PM Also got a nice new work-bench from HGR when I was out there 21-Mar-20 06:17 PM was supposed to be out that way much longer but beerpocolypse shut down the one place my friend wanted to go to and my other friend in PA locked his door and threw the key away so yea... 21-Mar-20 06:17 PM Got back early and using the rented Ford Transit for the next few days to move/organize stuff around my house and my friends place 21-Mar-20 06:19 PM what part of these pumps usually dies/requires replacing? 21-Mar-20 06:19 PM So... depends 21-Mar-20 06:19 PM first thing to go will be seals 21-Mar-20 06:19 PM rubbers/cork/etc 21-Mar-20 06:19 PM you definitely know thats a problem when your pump is constantly leaking oil 21-Mar-20 06:19 PM either from the shaft seal where the pump connects or the bellhousing 21-Mar-20 06:20 PM His pump stopped pulling good vacuum after a really long bakeout time for his foreline trap 21-Mar-20 06:20 PM probably seals if it was pumping pretty good before hand 21-Mar-20 06:20 PM vanes are PROBABLY ok then 21-Mar-20 06:20 PM but you would need to tear it down, and see what the vanes look like 21-Mar-20 06:20 PM you can compare the size to what new ones look like to get an idea of how worn they are 21-Mar-20 06:20 PM but ultimately even after you rebuild with fresh vanes there will be a bit of a wear in time I assume 21-Mar-20 06:20 PM ALSO a good flushing of the pump with flushing fluid can help sometimes 21-Mar-20 06:20 PM but ultimately I bet the seals failed which means your getting vacuum leaking between the different vane stages and the bell-housing/etc 21-Mar-20 06:21 PM If the burnt stuff was ingested by your pump, I would not count on the vanes being okay unfortunately @samy 21-Mar-20 06:22 PM well, either way you need to tear it down if you plan to rebuild and if you don't plan to its whatever, tear it down for scrap 21-Mar-20 06:22 PM so tear it down, check it out, and DO NOT store parts without them being covered in oil 21-Mar-20 06:22 PM so just like tear it down, get some old plastic containers and put the parts in there and check it all out 21-Mar-20 06:22 PM leave the old oil on them until you go to rebuild 21-Mar-20 06:22 PM and when you clean parts in the ultrasonicator after removal from your cleaning fluid/water/etc and they are done being cleaned IMMEDIATELY coat in new oil 21-Mar-20 06:22 PM otherwise surface rust will form quickly :) 21-Mar-20 06:23 PM ok cool 21-Mar-20 06:24 PM but yea, it will be messy, take up a lot of bench space, and is in general not very fun 21-Mar-20 06:24 PM Can you show a picture of what you found in your foreline? 21-Mar-20 06:24 PM but yea get the exploded diagram from the manual and have at it! 21-Mar-20 06:24 PM the leybold manuals have good instructions of teardown/assembly 21-Mar-20 06:24 PM they are a little confusing... but you'll figure it out 21-Mar-20 06:33 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_9025-B49E5.JPG 21-Mar-20 06:33 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_9026-714B9.JPG 21-Mar-20 06:33 PM guessing i can access the zeolite from that large hex nut, you want me to open that? 21-Mar-20 06:34 PM Yeah 21-Mar-20 06:41 PM k 21-Mar-20 06:59 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_9027-4D5F8.JPG 21-Mar-20 06:59 PM it tastes burnt 21-Mar-20 07:00 PM https://www.idealvac.com/Zeolite-Charge/pp/P105408 21-Mar-20 07:00 PM definitely not a good ice cream topping 21-Mar-20 07:00 PM Supposed to look pretty much white when new 21-Mar-20 07:00 PM ahh 21-Mar-20 07:01 PM So yeah, the 20 hr bakeout was too long, for both your zeolite and the pump with fully open gas ballast 21-Mar-20 07:01 PM so pump shouldn't have gas ballast open that long? 21-Mar-20 07:01 PM i was going through the trivac manual and didn't notice anything about time limit on gas ballast but maybe i missed it 21-Mar-20 07:02 PM 20 hours is really pushing it, not for your pump but for your oil 21-Mar-20 07:02 PM ah 21-Mar-20 07:03 PM The operating temperature is higher and the oil will degrade above a certain temperature, even much lower than the flash point 21-Mar-20 07:03 PM It can lose viscosity or just generate solid impurities that might damage your pump. So only open when necessary and for bakeout of the foreline trap, a few hours should be more than enough 21-Mar-20 07:09 PM ahh ok, thanks 21-Mar-20 07:09 PM would this work? https://www.ebay.com/itm/HFS-R-Molecular-Sieve-Zeolite-3A-8X12m-5lbs/292500146866?epid=11017207402&hash=item441a5e0ab2:g:VlEAAOSwRW9cZNVa 21-Mar-20 07:13 PM https://www.ldsvacuumshopper.com/mositrb1zepe.html 21-Mar-20 07:14 PM thanks 21-Mar-20 07:15 PM You don't need all 5 lbs right? LDS might be even cheaper in that case 21-Mar-20 07:18 PM prob not, i'll weigh how much 21-Mar-20 09:10 PM Who’s thirsty? 21-Mar-20 09:10 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_9046-8FE56.JPG 21-Mar-20 09:12 PM did you mix a couple types of oil? 21-Mar-20 09:12 PM looks like a mix + water emulsion 21-Mar-20 09:15 PM Are you sure it’s not activated charcoal pellets mixed in with zeolite? Charcoal was the preferred sorption media at one point. 21-Mar-20 09:28 PM no idea 21-Mar-20 09:28 PM i replaced the oil only once for a few mins 21-Mar-20 09:28 PM but everything is used so no idea original conditions of things 21-Mar-20 09:40 PM Can’t get these tie rods out. Very odd security screw head, haven’t seen before 21-Mar-20 09:40 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_9051-8EEAE.JPG 21-Mar-20 09:53 PM Do you have a 3 phase outlet? 21-Mar-20 09:53 PM Cause I bet you could get a free working one 21-Mar-20 10:07 PM i don't think so...i could make an outlet but i don't know i have 3 phase power at all? 21-Mar-20 10:07 PM i'm going to try to make the security screw 21-Mar-20 10:07 PM will look up how to soften a screwdriver bit and just mill out the middle 22-Mar-20 01:26 AM first-pass at vacuum deposition control system written in Python, using threads so all the gauges and logging/output/control loop should act independently and as fast as possible (i.e. if writing to the LCD panel is slow, it shouldn't limit the vacuum feedback in the deposition control loop): https://github.com/nmz787/vacuum/blob/master/main_system_control.py 22-Mar-20 01:26 AM haven't tested this particular file yet on my rasPi... but I think it should work 22-Mar-20 08:31 AM moin! 22-Mar-20 09:06 AM morning 22-Mar-20 09:34 AM nmz you could take all your newfound free time to comment the code to obliviion and beyond 22-Mar-20 01:49 PM @idmb heh, well I wrote it in like an hour lr two then went to the lab to wrap my chamber in heater coil and then finally actually try testing it 22-Mar-20 01:49 PM Left home at like 2am and got home at like 5:30 22-Mar-20 01:49 PM And honestly, I don't have a bit more free time with the whole pandemic thing 22-Mar-20 01:49 PM Most of my life was already pretty darn socially distanced, working from home, live 5 min drive from the lab I part-time at 23-Mar-20 05:44 AM @nmz787 sorry I didn't see your question from a few days ago, for some reason the notification never showed up for me. Really for an ICP, or any plasma source, higher input power means higher intensity and greater ionization. Power will depend on your process and process gas, since different gases have different ionization thresholds assuming all other things are equal. Really in comes down to plasma intensity and process gas handling. Some processes may need less intense plasmas, like some cleaning applications, vs high intensity higher density plasmas like RF sources for high beam current ion guns, etc. Also higher power will allow you to probably handle more process gas and larger processes in general assuming your pumping system can keep up with the load. 23-Mar-20 05:44 AM For things like cleaning, higher intensity means faster times, but too high intensity and you will start damaging your work piece from excessive sputtering and heating 23-Mar-20 05:52 AM Hmm, ok, cool... Now I seem to recall reading a while ago about the pressure of the gas changing the power required 23-Mar-20 05:52 AM I've got a 1000W RF generator for 13.56 MHz... So I don't think I'm running out of power anytime soon for my projects 23-Mar-20 05:52 AM But good to know, if it isn't sparking a plasma, try adding more power or pumping the pressure down more 23-Mar-20 06:03 AM Too low pressure and you won't be able to ignite the plasma though, you don't need crazy low pressures. But if you got 1kW for 13.56MHz, you are definitely set lol, that's a ton of power 23-Mar-20 06:03 AM What are you looking to do? 23-Mar-20 06:05 AM Maybe DRIE, some plasma enhanced atomic layer deposition I think, metal sputtering 23-Mar-20 06:05 AM Make cool glowy stuff, impress my less lab science geeky friends 23-Mar-20 06:07 AM Nice lol, yeah you are more than fine for those things. Especially RF sputtering, if you go too high power you can thermally shock the target material and cause it to crack, depending on the material you are sputtering 23-Mar-20 06:07 AM Do you have matching networks to adjust tuning into the system? 23-Mar-20 06:07 AM With that much power you could make a honking big RF plasma thruster lol, like some seriously high power system 23-Mar-20 06:39 AM Speaking of impedance matching, I am currently working on a RF generator for driving a q-switch. I have assembled a class AB linear amplifier kit that has an output power rated at 100W. The goal is to output a 27.12 MHz signal that is modulated at a high frequency (up to ~100 kHz). This big amplifier needs a +35 dBm input signal, that's 3W, and to generate this on a budget, I plan to use a DDS chip to synthesize the signal, use a cheap low power RF transistor to modulate it at the source, and put together several class E amplifiers in parallel to get it up to 35 dBm 23-Mar-20 06:39 AM High power RF transistors are expensive, but smaller ones down to perhaps 1W of output are much more commonly available. The required gain from the DDS is about 40 dB at the very least, so in each of the parallel amplifiers, I'll need to potentially use multiple transistor stages all chained together 23-Mar-20 06:39 AM https://people.physics.anu.edu.au/~dxt103/class-e/ 23-Mar-20 06:39 AM The more I think about this the sillier it becomes, and I worry about impedance and gain mismatches that might further reduce the efficiency and power output. 23-Mar-20 06:39 AM Linearity here pretty much doesn't matter, efficiency doesn't matter that much neither, so I think there's got to be a better solution 23-Mar-20 08:04 AM Any one with experience in FIB tomography? 23-Mar-20 02:13 PM @mike crb I've tried doing some FIB stereography... Didn't know tomography was a thing FIB could do 23-Mar-20 02:13 PM @mike crb if you have a simple test, I could give it a try 23-Mar-20 03:48 PM @Mason_Yu Find a little MACom or Mico Circuits brick on ebay that bridges the gap from something like +5 or +15 dBm to 35. The low frequency models are usually pretty cheap. I spent a hell of a time making a pushpull 2n3904 amplifier that just barely reached +21 dBm at 29Mhz before the gain flattened. Reflecting on that, just make simple 2N3904 Class A's to go from sig-gen/oscillator up to the first amplifier brick I'm suggesting, then into your AB kit. 23-Mar-20 04:32 PM @nmz787 yeah you can actually get some pretty incredible 3d stacks out of it. https://youtu.be/9zZON-T9UKc 23-Mar-20 04:32 PM Most people use it for tomography of cells and bio stuff. I’m trying to use it for tomography of nanoparticles, but all the protocol our facility has written down is for cells. Trying to figure out the proper beam currents and procedure for doing nm scale stuff 23-Mar-20 05:32 PM @mike crb oh that's https://en.m.wikipedia.org/wiki/Serial_block-face_scanning_electron_microscopy 23-Mar-20 05:32 PM I've not really heard of that being referred to as tomography 23-Mar-20 05:32 PM Most likely for nm scale, you'll probably want to use a 1pA beam, and do like 1 second FIB scans between your SEM imaging scans 23-Mar-20 05:32 PM 1pA is usually the smallest beam current available, and you'll chew away some nano particles just during focusing. Focusing doesn't matter as much for the FIB beam if you don't care about the edges of your scan area being crisp... I.e the center of the FOV should be just as evenly ablated 23-Mar-20 05:32 PM I want to do that technique with my FIB, but need to build or retrofit a SEM column to it 23-Mar-20 06:29 PM https://www.ebay.com/itm/2MHZ-700MHZ-3W-HF-VHF-UHF-FM-transmitter-RF-Power-Amplifier-For-Ham-Radio-X-sz/283486549313 23-Mar-20 06:29 PM @Laughing eBay came in and saved the day 23-Mar-20 06:29 PM The shipping time is a bit annoying, but certainly cheaper than getting proper high power RF transistors 23-Mar-20 06:29 PM Trying to get this shipped along with a bunch of chips, passive components and dev boards from China as one package 23-Mar-20 06:45 PM @nmz787 Zeiss refers to it as tomography so our department just kinda always called it that i guess. I’ve always thought block face was just with a microtome. 23-Mar-20 06:58 PM Ah, well I've got a few FIB only biological examples here, with moving GIFs https://imgur.com/gallery/YQwPaMe 23-Mar-20 06:58 PM Image quality is definitely not as great as SEM can be 23-Mar-20 06:59 PM Yeh I’ve thought about doing it that way but I’m trying to accurately determine contact angle from this as well, so top down I’m worried I may lose some detail 23-Mar-20 06:59 PM I’ll send the manual from Zeiss for their tomography software, pretty interesting procedure. 23-Mar-20 06:59 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/ATLAS_3D_User_Guide-95199.pdf 24-Mar-20 02:11 AM Man I really want to make my system into a dualbeam 24-Mar-20 12:33 PM @Mason_Yu You don't really need "several class-e amplifiers" to generate 3W. Throw a 13.56MHz crystal in to this. change the low pass filter for something like 15MHz corner frequency and don't add a modulator. Adjust PA voltage down to get only 3W output. https://hfunderground.com/blog/?p=72 24-Mar-20 12:33 PM @Mason_Yu ChrisSmolinski complained that that type of ebay amplifier is not long lived, as he's broken several. I recently got one but I'm yet to properly measure it. 24-Mar-20 12:33 PM Sorry for the double ping 24-Mar-20 03:54 PM Oh interesting, didn't know you could push a cheap little mosfet like that to these frequencies. Certainly easier and cheaper than chaining tiny RF BJT stages together. Thanks @rfs ! 24-Mar-20 03:54 PM I'll still use the DDS chip to drive the IRF510, since I've already got it and it's probably necessary to do some frequency tuning later on 24-Mar-20 03:54 PM I did just purchase that particular kit from eBay, so I'll have something to fall back to. 24-Mar-20 03:54 PM This particular RF MOSFET that came with my kit looks very secondhand 24-Mar-20 03:54 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20200324_185821-08FEA.jpg 24-Mar-20 03:54 PM So I don't know about their lifetime, will need to bolt a big heatsink onto it and just hope for the best at the moment 24-Mar-20 03:54 PM One particular requirement is that the RF signal will need to be modulated at a high frequency, with a rise time of 500 ns maximum. I'm a bit concerned that due to gate capacitances of the two main power amplifiers I have, this might not be achieved 24-Mar-20 03:54 PM The eventual goal is to push for even higher frequencies, down to pulse widths of hundreds of nanoseconds, so the risetime is even more important 24-Mar-20 03:54 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-2C6C3.png 24-Mar-20 04:03 PM The DDS chip will not have enough drive for the IRF, that's why the LULU uses a 74HC240 with all the gates in parallel. 24-Mar-20 04:03 PM And yes all the chinese MRF186 based amplifier kits use second hand mosfets 24-Mar-20 04:04 PM Oh yeah I'll have another stage with a simple BJT to drive the mosfet 24-Mar-20 04:04 PM Only way they are that cheap. 24-Mar-20 04:04 PM Just don't overdrive them and heatsink them well. 24-Mar-20 04:04 PM And hope the amplifier design is stable to the load you are using and it's should last a long time 24-Mar-20 04:05 PM How can I calculate the RF risetime if I modulate the signal at the source? I.e the DDS? 24-Mar-20 04:05 PM 500ns is a long time when you think in terms of MHz, the amplifier will do fine 24-Mar-20 04:05 PM and you can likely modulate the amp with 1kHz square wave (if that's ok) by driving that 1kHz to the 74HC240 enable pin 24-Mar-20 04:07 PM I'll need much faster than 1 kHz, around 100 kHz and probably more 24-Mar-20 04:07 PM And if you have a P-mosfet in series with the PA VCC than that should also work 24-Mar-20 04:07 PM Gona be fun sidebands for days, but's why you are on ISM and shield things. 24-Mar-20 04:08 PM Oh yes this will be in an aluminum project box, also use it as a heatsink for the IRF510 lol 24-Mar-20 04:09 PM Do note that the IRF510 tab needs to be insulated from the heatsink. 24-Mar-20 04:23 PM Yes, I'll use silicone or mica pads. Upon looking into this, I think the fall time might be the issue here, it's 100 ns maximum 24-Mar-20 04:23 PM This is simple enough that I might try to model it in Pspice, but hard to know the inductances of the hand-wound transformers. I might be just paranoid and it is probably faster to build and test 24-Mar-20 04:23 PM Shouldn't break the q-switch, worst case is a bad pulse 25-Mar-20 09:36 AM Turns out when you shut off your gas source for a lockdown, you get excellent pressures. Who knew lol : 25-Mar-20 09:36 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screen_Shot_2020-03-25_at_9.34.42_AM-2A392.png 25-Mar-20 09:36 AM Torr & not my program so the sig digs are way off of course 25-Mar-20 12:59 PM How are the sig digs off? Ugly, but they aren't lying are they? 25-Mar-20 12:59 PM Just showing more than actually resolvable? 25-Mar-20 01:09 PM they're 10% accuracy 5% repeatability gauges 25-Mar-20 01:09 PM so showing anything above 0.1% as the read value is insane 25-Mar-20 01:09 PM the bottom tiny font one is also read via banana plugs going 3m to an ADC 25-Mar-20 01:09 PM so is certainly a lil off 26-Mar-20 06:06 PM Really wished I had a glide plasma treater built for cleaning my groceries that I brought home today 27-Mar-20 01:39 AM Do they work on viruses? I know it's good on bacteria. 27-Mar-20 01:39 AM My biology knowledge is 0 27-Mar-20 01:41 AM well, I'm pretty sure an oxygen plasma helps with everything, be it living matter or just large biomolecules 27-Mar-20 01:50 AM I just know biostuff can be surprisingly resilient 27-Mar-20 08:32 AM Virus coat is just fat and/or protein, so it should be effective 27-Mar-20 08:35 AM Someone at the makerspace was talking about using an ozone generator for a similar purpose. 27-Mar-20 08:43 AM I'd guess that would need a longer treatment time, just due to being less energetic that direct plasma 27-Mar-20 08:57 AM https://www.researchgate.net/publication/289502225_Cold_Physical_Plasmas_in_the_Field_of_Hygiene-Relevance_Significance_and_Future_Applications 27-Mar-20 08:57 AM seems to be working OK on viruse 27-Mar-20 09:12 AM couldn’t you just get like a UVC lamp and put it in an isolated place? 27-Mar-20 09:13 AM But where is the fun in that? 27-Mar-20 09:13 AM haha true 27-Mar-20 09:14 AM I mean technically that kind of virus dies in <24h on even porous surfaces. <10 hours on smooth stuff 27-Mar-20 09:14 AM So you can just wait it out for most things 27-Mar-20 09:16 AM Uhh 27-Mar-20 09:16 AM Not... Exactly... 27-Mar-20 09:16 AM It's a half life / difussion type thing. The more it spreads out the faster it becomes irrelevant, and in certain environments (copper etc.) it dies quicker 27-Mar-20 09:17 AM Really? friend at CDC sent me this: https://www.nejm.org/doi/10.1056/NEJMc2004973 27-Mar-20 09:17 AM So yeah, you get a half life kind of thing 27-Mar-20 09:18 AM Yeah. Which is not the same as "it's dead" 27-Mar-20 09:18 AM but still negligible for >24h 27-Mar-20 09:18 AM Negligble for what? 27-Mar-20 09:19 AM Contamination wise 27-Mar-20 09:19 AM I mean I am no biologer, so definitely could be in the wrong there 27-Mar-20 09:20 AM It's more stats than bio. Tiny probability x big population = not zero 27-Mar-20 09:20 AM Ok fair enough 27-Mar-20 09:21 AM It also depends on a lot of things - Do I think the general public should be told to leave all their mail for two weeks before opening it? No 27-Mar-20 09:21 AM Without reading that article in full - Isn't the difference between copper and cardboard a chemical vs mechanical thing? 27-Mar-20 09:23 AM I don't think they say much about root cause there 27-Mar-20 09:23 AM mostly a slap dash: we did the measurement, here are the results 27-Mar-20 09:23 AM came out early this week or something 27-Mar-20 09:23 AM so I imagine people in the field mostly want data now to get guidelines out and things like that 27-Mar-20 10:31 AM Well they just found active virus on that cruise ship that sat uncleaned for 18 days 27-Mar-20 10:31 AM So the whole hours vs days thing has gone up to weeks now 27-Mar-20 10:32 AM did they? wow 27-Mar-20 10:32 AM @mike crb I don't have stuff to build a UVC lamp, but do have the stuff for a plasma arc 27-Mar-20 10:33 AM anything specific that seems to make it "live" longer? 27-Mar-20 10:33 AM It doesn't specifically say active virus, just 'traces' which for a newsmedia article could actually mean anything 27-Mar-20 10:33 AM https://www.google.com/amp/s/abcnews.go.com/amp/Health/diamond-princess-traces-coronavirus-17-days-ship-emptied/story%3fid=69755804 27-Mar-20 10:34 AM RNA is not the same as active virus, yeah 27-Mar-20 10:34 AM https://www.usatoday.com/story/travel/cruises/2020/03/24/coronavirus-diamond-princess-cabin-surfaces-contaminated-cdc-report/2905924001/ 27-Mar-20 10:34 AM " Corrections & clarifications: The Centers for Disease Control found that novel coronavirus RNA, or genetic material, not the coronavirus itself, was identified on surfaces in Diamond Princess cruise ship cabins up to 17 days after cabins were vacated." 27-Mar-20 10:51 AM That still isn't clear if they tried to infect cell cultures and failed 27-Mar-20 11:10 AM That still wouldn’t be a full result 27-Mar-20 11:10 AM You can’t prove it can’t happen 27-Mar-20 11:30 AM Well I mean, that genetic material could have worked to infect cells, but they don't specify what they actually did or didn't try 27-Mar-20 11:30 AM If they didn't even try that, well, then it's still up for Wondering if it could be infectious still 27-Mar-20 11:30 AM Like, did they do TEM analysis and not see virus particles, only RNA? Or did they just do a simple solvent extract and run gel electrophoresis 27-Mar-20 11:30 AM Etc etc 27-Mar-20 11:36 AM Yeah I’m just saying in terms of what you or I can guess (being non-experts), if they didn’t do the experiment they probably assume the results are either meaningless or very difficult to obtain 27-Mar-20 12:06 PM It sounds like once it’s protein envelope is destroyed or desiccated it’s inert but still is detected in a test due to the method of the test looking at the reactions along the RNA chain. Some of the tests are actually looking for a spike in photon emission when the test chemical interacts with the targeted chain in the RNA. Pretty crazy 27-Mar-20 12:06 PM Mentioned in another post that I wonder if high vacuum can destroy the virus. Perhaps masks and gowns could be reused that way. 27-Mar-20 12:11 PM Vacuum likely wouldn't do anything but preserve it 27-Mar-20 12:11 PM The thing is, to do the RNA test, you'd have to deatroy the protein envelope 27-Mar-20 12:11 PM And yeah, all the testing methods in use today for this are optical at the final detection instrument 27-Mar-20 12:11 PM qPCR aka rtPCR 27-Mar-20 12:11 PM https://en.m.wikipedia.org/wiki/Real-time_polymerase_chain_reaction 27-Mar-20 02:15 PM Joined the server. 28-Mar-20 10:23 AM any suggestions on cheapest way to make LN2 at home or specific cryopumps/cryoheads that are suggested? or i if i wanted to make dry ice on demand, how much i could recover from a CO2 tank? 28-Mar-20 10:29 AM You need to be using a LOT of LN2 or already have/want a cryo cooler in order for it to be cheaper to make it, I believe? Depending on if you can just go out and buy it where you are I guess 28-Mar-20 10:29 AM looks like LHe is $16/L here, nitrogen is like $0.1/L 28-Mar-20 10:29 AM I don't believe you can make your own setup for less than $500, and doing it "easily" is probably more like $1500? 28-Mar-20 10:35 AM buying LN2 yourself without being attached to a university or something is not exactly cheap... 28-Mar-20 10:35 AM something like $5/L @5L to $2.75/L@50L 28-Mar-20 10:37 AM @idmb i would be interested if i could do it for < $1000 28-Mar-20 10:41 AM doing it for under $1000 would take a lot of luck and some creative sourcing of components. you probably would not want to be using gas tanks for LN2 but rather a nitrogen concentrator system. 28-Mar-20 10:41 AM you might want to check out this guy's page: http://homemadeliquidnitrogen.com/PSA/ 28-Mar-20 10:41 AM the pressure swing adsorber is probably the cheapest way to do nitrogen concentration without getting very lucky on a membrane system 28-Mar-20 10:41 AM no idea about your CO2 followup 28-Mar-20 10:43 AM interesting 28-Mar-20 11:40 AM Unfortunately LN2 for consumers is usurious. 28-Mar-20 11:40 AM Part of the problem is that most experimenters don’t have DOT approved transport dewars. 28-Mar-20 11:40 AM And also, at small volumes, the LN2 wasted in cooling down the dewar and the labor needed to do the fill becomes more significant. 28-Mar-20 11:40 AM Also this brings up an important safety issue. Please be very careful transporting LN2. If you’re getting asphyxiated, you probably won’t be capable of realizing it. 28-Mar-20 11:50 AM most people do not even have long term storage dewars much less transport dewars too 28-Mar-20 11:50 AM so you have to factor in a $25 delivery charge 28-Mar-20 11:55 AM We got a 44L sample storage dewar for cheap. Was used for... cattle breeding purposes. 28-Mar-20 11:55 AM We made sure the inside was well cleaned, as we intended to make ice cream as a secondary purpose, and didn’t want bull flavored ice cream. 28-Mar-20 11:59 AM :D 28-Mar-20 12:00 PM An immature makerspace member decided to draw crude illustrations on the dewar. 28-Mar-20 12:00 PM This was while I still had the SEM at the makerspace. 28-Mar-20 12:00 PM It wasn’t a good fit. We agreed to have Pumping Station: One donate the SEM to Analytics Lounge. 28-Mar-20 12:00 PM The dewar went with, as it was primarily for the Si(Li) EDX, and later my HPGe, and the desktop XRF which also has Si(Li). 28-Mar-20 12:00 PM That said, LN2 + Baileys Irish Cream = 34 proof ice cream = heaven 28-Mar-20 12:11 PM This also taught me about hysteresis effects in cheap load cells. I tried to hack a bathroom scale to measure LN2 level. It wasn’t all that successful. 28-Mar-20 01:32 PM yeah would be nice if i could just make LN2 and not deal with transporting it 28-Mar-20 03:41 PM @Mason_Yu Just did some measurements of the aliexpress "2-700MHz" amplifier and it has large amounts of gain. -10dBm drive on 13.56MHz gives out +33dBm, for a nice 43dB of gain 28-Mar-20 03:41 PM But the output is pretty dirty so it's likely quite compressed at that power level. 28-Mar-20 03:41 PM -30dBm of drive resulted in +19.4dBm of output and MUCH cleaner spectrum. 28-Mar-20 03:41 PM But I don't believe that this amplifier is usable for your application 28-Mar-20 03:41 PM As even with that +19dBm output the PA transistor got incredibly hot in just seconds 28-Mar-20 03:49 PM What’s it heatsinked with? 28-Mar-20 03:50 PM Soldered to vias 28-Mar-20 03:50 PM This amplifier https://www.aliexpress.com/item/32970106683.html 28-Mar-20 03:50 PM The gate bias is 3.5volts too 28-Mar-20 03:50 PM so I guess it's biased to be quite linear to get that amount of gain 28-Mar-20 03:52 PM Oh wait, it’s already assembled 28-Mar-20 03:52 PM One similar had some RD series mitsubishi VHF/UHF mosfet on it. 28-Mar-20 03:52 PM Yeahj ready made module 28-Mar-20 03:52 PM And just to double check, impedance that it was output into? 28-Mar-20 03:59 PM 50ohms 28-Mar-20 03:59 PM 150cm of RG316 to my R&S CRTU-RU 28-Mar-20 03:59 PM I'm also using it as the signal generator for driving the module. 28-Mar-20 04:00 PM Just wanted to ask 28-Mar-20 04:00 PM That's why I'm limited to -10dBm at the port I'm using. 28-Mar-20 04:00 PM CRTU-RU is a fun toy 28-Mar-20 04:00 PM It can take 50W CW on the main input and 2W on the other one 28-Mar-20 04:03 PM Oh interesting 28-Mar-20 04:03 PM It's a cellphone tester 28-Mar-20 04:03 PM but it has a 100kHz-2700MHz signal generator and power meter and 10-2700MHz spectrum analyzer 28-Mar-20 04:03 PM And most CRTU-RU's I have seen have the 50W input option, some rare one's have only 2W 28-Mar-20 04:03 PM CMU200 is similar but here the 2W option is the common one and 50W the rare one. 28-Mar-20 04:03 PM For the 250eur I paid for this it's nice 28-Mar-20 04:05 PM Oh that sounds very nice for 250eur 28-Mar-20 04:07 PM Anomalously good price, but these are often under 500eur 28-Mar-20 04:07 PM which is an excelent price for what one gets, imo 28-Mar-20 04:07 PM It can also act as a GSM basestation :D 28-Mar-20 04:16 PM I'm unsure about the CRTU-RU, but for CMU200 the spectrum analyzer, powermeter and signal generator are part of the base options, so all of them have it. 28-Mar-20 04:16 PM Both should also have a triggerable power meter that can sync to exteral sources 28-Mar-20 04:16 PM really good for seing the keying envelope of transmitters and measuring the putput power of pulsed systems 28-Mar-20 04:16 PM or just systems with TDMA 28-Mar-20 04:16 PM like GSM, TETRA and DMR 28-Mar-20 04:16 PM And you can also see if the power rises and falls fast enough to keep within spec. 28-Mar-20 04:17 PM If I was going to be doing more radio stuff, I’d really be starting to think about tracking down something like that 28-Mar-20 04:17 PM There's also comparable units from HP (old) and Anritsu 28-Mar-20 04:17 PM A friend of mine has an Anritsu unit and he says it's superior in everyway to the R&S unit 28-Mar-20 04:17 PM and some friends have old HP units 28-Mar-20 04:17 PM The R&S UI for example is not very intuitive. It's very german but I have been able to figure out most things without bothering to find the manual. 28-Mar-20 04:17 PM While the Anritsu is genuinely intuitive. 28-Mar-20 04:17 PM And as these only do GSM and at most EDGE and for rare units WCDMA, they are no longer that desired 28-Mar-20 04:17 PM R&S CMW500 still goes for thousands of dollars as it does LTE and R&D folks love that 28-Mar-20 04:17 PM So old "Digital Communications Tester" and "Universal Protocol Tester" devices can be usefull. 28-Mar-20 04:17 PM Some devices are less usefull, like R&S CMD57, which is a basestation tester 28-Mar-20 04:17 PM And while it has a spectrum analyzer and signal generator, they are for 800-1000MHz & 1700-1900MHz and SLOW. 28-Mar-20 04:17 PM THe availability is a bit regional 28-Mar-20 04:17 PM With better availability where there has been or is cellphone related R&D or manufacturing 28-Mar-20 04:17 PM Like both my CMU200 and CRTU-RU are former Nokia 28-Mar-20 04:17 PM Tho the CRTU-RU came from the Oulu Broadcom auction. 28-Mar-20 04:17 PM But that's the former Nokia modem unit. 28-Mar-20 05:29 PM Joined the server. 28-Mar-20 05:30 PM Joined the server. 28-Mar-20 08:36 PM #introductions_and_directory 29-Mar-20 07:52 AM @rfs Thanks for sharing your experience with that PA module! The one I bought has a stated bandwidth of 1-1000 MHz with the maximum input power at +7 dBm, so I'm not sure if it's exactly the same with what's in that listing. I'm aware these PA modules usually runs super hot, and so I'm actually contemplating water-cooling the mosfet on the 100W PA with a water-block just before the laser, which takes chilled water 29-Mar-20 07:52 AM Well the graphics on the listing for my "2-700MHz" module show 1-1000MHz 29-Mar-20 07:52 AM And I don't doubt that +7dBm 29-Mar-20 07:52 AM It needs to be driven hard to giver out 3W, I only got two 29-Mar-20 07:52 AM +7dBm is likely also close to the absolute maximum limit for the MMIC used as the first stage. 29-Mar-20 07:52 AM And the output is very much not clean if driven that hard. 29-Mar-20 07:53 AM I'll try to go with the IRF510 route first 29-Mar-20 07:53 AM Thanks for pointing out these capable spectrum analyzers too! I've been looking into getting some cheap and relatively portable USB options, got the NWT4000-2 for $40 at factory pricing 29-Mar-20 07:53 AM Have you had any experience with these types of spectrum analyzers + tracking generators based on the cheap synthesizer chips like the ADF4351? 29-Mar-20 07:56 AM With an NWT one jsut needs to be aware of it's limitations 29-Mar-20 07:56 AM like no input filtering, fixed ~300kHz resolution bandwidth due to the low-IF/zero if design and that all the LO's are unfiltered 29-Mar-20 07:56 AM Some friends have NWT's and I'm constantly tempted by one 29-Mar-20 07:57 AM That 300 kHz resolution bandwidth is very annoying 29-Mar-20 07:57 AM As it goes up to 4.4GHz 29-Mar-20 07:57 AM Well who knows what resolution bandwidth the current variants have 29-Mar-20 07:58 AM I look forward to testing mine when it arrives, as far as usefulness/dollar spent I think it's hard to beat for newbies like me, I also don't have the benchspace for another big instrument 29-Mar-20 07:59 AM the idea is basically that they take the output from the mixer (an IAM-81008 by HP), low pass filter it, this also establishes the resolution bandwidth and feed that to an AD8307 log amp. 29-Mar-20 07:59 AM It also has catches for newbies 29-Mar-20 07:59 AM like how below 2200MHz the ADF gives out a square wave, so you can have spurious responses on it's harmonics on receive. The mixer used also has limited dynamic range compared to double balanced diode ring mixers, but that way they save on buying a more expensive mixer and on the buffer amplifier needed to drive one 29-Mar-20 07:59 AM SO attempting to receive 1000MHz will also have responses on 3000MHz, 5000MHz and so on 29-Mar-20 07:59 AM due to the square wave LO's. 29-Mar-20 07:59 AM Not as strong as the wanted one, but still. 29-Mar-20 08:19 AM I wonder why they chose to use the ADF4351 chip as the LO generator then, is that simply the cheapest chip out there with a PLL and VCO that covers such wide frequencies? 29-Mar-20 08:21 AM Cheapest solution 29-Mar-20 08:21 AM 10usd/pcs on digikey in single quantities, and MUCH cheaper in china 29-Mar-20 08:22 AM Yeah there are lots of sig gen kits made with that chip 29-Mar-20 08:22 AM MAX2780 does 23.5-6000MHz and used to be a few bucks cheaper on digikey, but it's much more expensive on the ground in china 29-Mar-20 08:22 AM The SAA-2/nanovna v2 developer quoted 10-8 times more expensive than ADF 29-Mar-20 08:22 AM I can't quite make out exactly what mixer this thing uses neither 29-Mar-20 08:23 AM If it's a SOIC-8 with "810" on it then it's IAM-81008. 29-Mar-20 08:23 AM https://www.qsl.net/n9zia/omnitracs/IAM81008.pdf 29-Mar-20 08:26 AM So there are quite a few revisions to the board, and for the one I bought, they've at least put the RF section under cans 29-Mar-20 08:26 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/TB2BmCKrwoQMeJjy0FpXXcTxpXa_61190180-ACF74.png 29-Mar-20 08:26 AM And what's limiting the sweeping rate and sample size of this thing? Just the puny STM32F103 MCU I guess? 29-Mar-20 08:29 AM STM, PLL settling time and software 29-Mar-20 10:32 AM @samy What is it you're trying to do with the vacuum / oven / LN2 stuff? Looking at your site and stuff it seems like you're mostly into showing security exploits that shouldn't exist etc. etc. 29-Mar-20 10:32 AM I'm pretty sure most university research labs are only (accidentally) protected via security-through-obfuscation where most of the important hardware is interfaced with computers poorly with no real security, but there are so many computers with miscellaneous stuff attached that can't do anything that figuring out which actually matter would be a bit of work 29-Mar-20 10:32 AM but stealing data would be trivial 29-Mar-20 10:38 AM @idmb just trying to learn how things work and experiment. i don't really know anything about these areas and they just seemed interesting 29-Mar-20 10:38 AM haha yeah, security is hard (hence why i enjoy the easy side of it, breaking!) 29-Mar-20 10:38 AM i'd say my primary goals are 1) understand more how things work 2) understand how to make/augment more things. i have a few project ideas in these areas that i've started since learning about this stuff but those are usually just to play around and apply whatever it is i'm messing with at the time 29-Mar-20 10:45 AM But what do you mean by "things" here? 29-Mar-20 10:45 AM Physics in vacuum? High/low temperature? Strong electric or magnetic fields? 29-Mar-20 10:45 AM yes 29-Mar-20 10:45 AM anything that i can potentially apply in a way that would make me smile later on 29-Mar-20 10:46 AM So just your own physics playground as far away from earth's atmosphere/environment 29-Mar-20 10:47 AM unfortunately i have zero science background, not even high school classes so jumping in to learn a bit, but applied stuff seems fun 29-Mar-20 10:47 AM since i've started i have a few things in mind that seem fun - one requires ITO sputtering, so that's been a good reason to begin building out vacuum stuff 29-Mar-20 10:48 AM khan academy can catch you up to ~3rd year undergrad haha 29-Mar-20 10:49 AM oven because i want to anneal / heat treat stuff. just recently started to mill, turn, weld (all very poorly), and i broke my vacuum pump and tried tearing it down but had a security bit, so i tried milling a security bit out of a hardened metal and couldn't...so now i want to be able to soften hardened metal (i ended up milling out of a softer steel and was able to remove the security bits) 29-Mar-20 10:49 AM But a lot of what you can actually do with this stuff isn't really clear from doing basic science 29-Mar-20 10:49 AM good idea! i've been going through an Openstax textbook 29-Mar-20 10:50 AM Like you have to get really into condensed matter before annealing is something you can just figure out, typically it's more empircal. And luckily there are tons of resources of "do X, get Y" 29-Mar-20 10:50 AM basically phase transitions & electrochemistry are all that seems to really get directly applied from textbook to practice 29-Mar-20 10:51 AM ahh 29-Mar-20 10:51 AM The other stuff to me seems more "someone figured out it worked this way, and it works really well this way" 29-Mar-20 10:51 AM I guess I'm pretty naive on that front, clearly there are a lot of people with a lot of expertise that isn't just from trial-and-error 29-Mar-20 10:55 AM interesting 29-Mar-20 10:55 AM what got you into this stuff / what areas are you interested in? 29-Mar-20 10:59 AM I got into vacuum stuff because it's how you get nicer samples for the laser stuff for my grad school research. (Specifically, can put molecules in their ground state and can have them interact with superfluids) I started with the research group in my undergrad because the description sounded cool - "We use a unique tool called an optical centrifuge to make molecules spin at up to 10 THz" 29-Mar-20 10:59 AM and then was deciding between that and quantum simulations using ultracold gasses when applying to grad school 29-Mar-20 10:59 AM But since I liked working with this group as an undergrad I stuck with it, it was still a different university from my degree 29-Mar-20 10:59 AM as for physics in general? I thought I wanted to do more engineering stuff but found in first year the courses were too protocol-based for me so switched to physics 29-Mar-20 10:59 AM I didn't really have a specific reason for wanting to go into either before that though! 29-Mar-20 10:59 AM But basically any vacuum stuff I do is just a byproduct 29-Mar-20 11:09 AM ahh very cool! 29-Mar-20 11:09 AM new oil should be coming today so i'm tearing down vacuum pump - any suggestions on cleaning everything, fasteners, etc? just soap and water and then dry everything thoroughly to prevent rest + apply oil immediately? 29-Mar-20 11:17 AM No idea, our oil pumps haven't been serviced for 6+ years and they just work. 29-Mar-20 01:19 PM @samy my guess water and soap, then some alcohol should be good 29-Mar-20 01:19 PM Alcohol will mean it dries pretty fast 29-Mar-20 01:19 PM Really depends though on the parts 29-Mar-20 01:19 PM Some stuff acetone might also be OK/helpful 29-Mar-20 01:20 PM You can use a heat gun to help dry the all-metal parts 29-Mar-20 01:20 PM Or an oven 29-Mar-20 01:20 PM Preferably electric 29-Mar-20 01:27 PM @nmz787 thanks - why electric? 29-Mar-20 01:27 PM is denatured alcohol okay or could that be an issue with these parts? 29-Mar-20 01:27 PM Just less combustion gas potential 29-Mar-20 01:27 PM Moisture is a combustion gas for example 29-Mar-20 01:27 PM Denatured could be an issue, depending on what part 29-Mar-20 01:27 PM Screws, likely not 29-Mar-20 01:27 PM Since this is a rough pump, probably doesn't matter in general is my guess 29-Mar-20 01:27 PM They're made to allow some contamination in the oil from stuff you're pumping 29-Mar-20 01:29 PM mine had soooo much cruft inside...it's ridiculous 29-Mar-20 01:29 PM So probably wouldn't be too worried... 29-Mar-20 01:29 PM You're gonna make it a lot cleaner 29-Mar-20 01:29 PM i'm actually stuck, i can't figure out how to remove any more parts 29-Mar-20 01:29 PM Seems loke denatured only matter in electron/ion optics, detector electrodes, that sort of stuff 29-Mar-20 01:29 PM Stuff where contamination would make some sort of change in the signal or electric field 29-Mar-20 01:29 PM Haha 29-Mar-20 01:29 PM Don't go for the hammer! 29-Mar-20 01:30 PM no promises 29-Mar-20 01:30 PM interesting 29-Mar-20 01:30 PM can't remove this part 29-Mar-20 01:30 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-39746.png 29-Mar-20 01:32 PM Looks like a flathead screw at the top/middle 29-Mar-20 01:32 PM Might just need to solvent soak that tho 29-Mar-20 01:32 PM manual assembly isn't showing any screws or anything and i've removed every screw i've found 29-Mar-20 01:32 PM if I were cleaning that I'd pop it in a sonicator 29-Mar-20 01:33 PM ah, what kind of solvent? 29-Mar-20 01:33 PM I mean, there's a big slot in that central item 29-Mar-20 01:33 PM Does the schematic show any gaskets in there? 29-Mar-20 01:33 PM If not, any industrial degreaser seems like probably OK 29-Mar-20 01:33 PM #3 is what i'm trying to remove 29-Mar-20 01:33 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_2020-03-29_13.33.33-741BC.png 29-Mar-20 01:33 PM i removed gasket #2 - #5 is what you're seeing in the middle 29-Mar-20 01:35 PM Is 13 gone too? 29-Mar-20 01:35 PM And 11? 29-Mar-20 01:35 PM 6 looks like maybe a bearing 29-Mar-20 01:35 PM Which probably wouldn't take kindly to random washing 29-Mar-20 01:37 PM 13's removed, i haven't removed 10 or 11 29-Mar-20 01:38 PM are there fasteners in those two holes in 3 that go through 7 and into the main frame 12? 29-Mar-20 01:38 PM Anything from the backside where the diagram says G 29-Mar-20 01:38 PM on the front or back 29-Mar-20 01:38 PM Yeah kinda looks like maybe @LRM 29-Mar-20 01:39 PM if the fasteners there already are removed or it is just pins things might just be press fit together? 29-Mar-20 01:39 PM definitely do not go tapping things loose until you conclusively determine that there are no fasteners! 29-Mar-20 01:39 PM Other side 29-Mar-20 01:39 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_9095-E6299.JPG 29-Mar-20 01:39 PM there is a rubber thing stuck in the large hole in the top of #3 (it connects to a oil line) that i can't get out, there were 3 more of those but they weren't holding anything together, just helped to seat/seal pipes 29-Mar-20 01:41 PM would have to be on the pump side then...anything down in the holes that line up with the holes on the parts diagram in the flat seal 7 29-Mar-20 01:41 PM Might try feeling in those holes with an allen wrench 29-Mar-20 01:42 PM there were screws in those 4 holes on back side, i removed htem 29-Mar-20 01:42 PM Pressure washer with hot soapy water? 29-Mar-20 01:42 PM but i'll check 29-Mar-20 01:42 PM D2.5E, right? https://www.idealvac.com/files/manuals/Leybold_D_E2_5OI.pdf 29-Mar-20 01:42 PM Seems least dangerous to gasket/orings 29-Mar-20 01:42 PM right 29-Mar-20 01:42 PM that has the diagram for anyone else 29-Mar-20 01:42 PM i have not taken mine down that far so i don't know anything more than the parts diagram but i would definitely investigate the holes that go through the seal 7 29-Mar-20 01:45 PM thanks @LRM - those two holes don't go anywhere - no fasteners in them 29-Mar-20 01:45 PM @nmz787 i don't have a pressure washer but have been meaning to get one, just any will do? 29-Mar-20 01:46 PM might be pins then...so if you are absolutely completely sure there are no fasteners it might be time to try gently tapping things apart 29-Mar-20 01:47 PM @samy yeah, the cheap ones are the lowest flow and weakest, so should be safest for this stuff 29-Mar-20 01:47 PM cool 29-Mar-20 01:47 PM Idk if pressure washing is actually a good idea 29-Mar-20 01:47 PM But it's an alternative to sonication 29-Mar-20 01:47 PM It's gentle enough to stick your hand in the spray 29-Mar-20 01:47 PM And not peel car paint 29-Mar-20 01:47 PM If you have a sonicator, then try that with soapy water 29-Mar-20 01:47 PM Harbor freight has good deal on one 29-Mar-20 01:49 PM i have a small ultrasonic bath but it's super small 29-Mar-20 01:49 PM Idk if they're an essential biz 29-Mar-20 01:49 PM cool i'll check it out 29-Mar-20 02:52 PM @nmz787 would you suggest just a large ultrasonic bath or one of those stick sonicators? 29-Mar-20 02:52 PM i have a 60W 40kHz transducer horn i could probably just attach something to, just would need to figure out the design 29-Mar-20 03:18 PM Stick sonicator is to break up biological cells, or mix stuff 29-Mar-20 03:20 PM ah 29-Mar-20 03:23 PM I mean they still help compared to just a solvent bath 29-Mar-20 03:23 PM but yeah a proper sonicator bath is much better for cleaning stuff like this 29-Mar-20 04:15 PM i destroyed a rubber seal that was hardened and wouldn't come out. i'd like to make a new one, i'm guessing it won't be a big deal if it's silicone or nylon in the foreline pump? or a suggested medium to use for a gasket type thing? (it's a rubber insert that seals the oil/gas ballast pipe) 29-Mar-20 06:55 PM FYI i was able to remove the #3 part (forevacuum pot) by twisting it with some force (the whole thing can turn freely afterwards) 29-Mar-20 09:30 PM I'm not sure nylon will be flexible or compressible enough to act as a gasket/seal 29-Mar-20 09:30 PM Silicone seems like it should be fine, at least from a chemical compatibility and thermal standpoint 29-Mar-20 10:13 PM cool 29-Mar-20 10:13 PM actually seems like 3d printing ninjaflex might be good, it's TPU and sounds like that may have a low outgassing rate 29-Mar-20 11:36 PM I don’t think outgassing is likely a concern in a roughing pump? More “will it self-destruct?” 29-Mar-20 11:53 PM ok cool 29-Mar-20 11:56 PM The pump also gets pretty hot internally, so the TPU may soften and degrade quickly. Besides it might not seal well if it's 3D printed 29-Mar-20 11:56 PM Can you just use an o-ring instead? 30-Mar-20 12:09 AM yeah, I'd just grab a sheet of silicone from ebay or amazon 30-Mar-20 12:09 AM something like this, says 3 or 4 day delivery for me here https://www.amazon.com/gp/product/B01N4KVHYD/ 30-Mar-20 12:09 AM then get a drafting/geometry compass to mark, or affix a razor/scalpel to the end, to cut 30-Mar-20 12:09 AM when I had to make one recently for my 10" pipe chamber, I placed a piece of thick paper over it and put a pushpin in the center, then just used the edge of the paper as my guide where to cut 30-Mar-20 12:09 AM you could use a piece of plastic string or something I guess 30-Mar-20 12:23 AM it's a weird part 30-Mar-20 12:23 AM essentially this 30-Mar-20 12:23 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_2020-03-30_00.23.41-54659.png 30-Mar-20 12:23 AM not transparent, just to get an idea of inside 30-Mar-20 12:23 AM a tube fits into it, and it hugs an outer valve 30-Mar-20 02:06 PM You can consider 3D printing or machining a mold and casting a high temperature RTV into it 30-Mar-20 02:06 PM How large is this part? 30-Mar-20 02:09 PM they are small if it is what i am thinking he is talking about 30-Mar-20 02:09 PM you can buy them from some vacuum supply places for about $5 each they are just "rubber insert" on the parts list 30-Mar-20 02:09 PM https://www.capvac.com/rubber-insert/ 30-Mar-20 02:09 PM never ordered from them but that looks like the part to me 30-Mar-20 02:28 PM ah nice 30-Mar-20 02:28 PM @Mason_Yu about 11mm tall 30-Mar-20 02:30 PM In fact I might be looking at buying some parts from them as well, for a Welch 8915 pump rebuild 30-Mar-20 02:37 PM hmm $5 for one of those and $16 for shipping...think i will try casting, but that's great to know as a backup for that or other parts! 30-Mar-20 02:39 PM Since it's a viton part, I'd just buy the OEM replacement and not have to deal with casting problems. A high quality high temp RTV tube already cost about that much 30-Mar-20 02:39 PM Have you inspected the rest of your pump yet? Any other parts that looks worn and can be replaced with a new one from their catalog? 30-Mar-20 02:44 PM there was a ton of thick dirty cruft...guessing rust? so soaking a bunch of it in some cleaning solution then evaporust then will oil down...on the motor side it does look like two little gaskets don't look perfect on the coupling between the motor and vacuum side but i'm not sure if those gaskets are actually in the vacuum side 30-Mar-20 02:44 PM https://www.capvac.com/d2.5e/ 30-Mar-20 02:44 PM Well, all the motor shaft seals cost very little, you should replace them while you have the pump open 30-Mar-20 02:46 PM ok thanks 31-Mar-20 03:26 PM Who here has experience in Al PVD? 31-Mar-20 03:26 PM I don't know what's realistic here, I need ~1 µm of Aluminium on some silicon 31-Mar-20 03:53 PM @GigaSquirrel I'd check here for chemical inputs and process refs https://www.atomiclimits.com/alddatabase/ 31-Mar-20 03:53 PM I was thinking to start with AlCl3 and water 31-Mar-20 03:53 PM Mostly just since it isn't pyrophoric and it's cheap on eBay 31-Mar-20 03:54 PM huh? 31-Mar-20 03:54 PM no, heat some elemental aluminium until it evaporates 31-Mar-20 03:54 PM easy as that 31-Mar-20 03:55 PM Sure, if that's good enough resolution/evenness and reproducibility 31-Mar-20 03:55 PM For your purposes 31-Mar-20 03:57 PM that's the standard procedure for coating stuff ^^ 31-Mar-20 03:57 PM either that or sputtering 31-Mar-20 03:57 PM you'd have to go to some really special stuff to get to a point where that's not enough 31-Mar-20 04:21 PM can you do it the same way as that telescope mirror coating video where they just stick some Al wire on tungsten heating elements? 31-Mar-20 04:21 PM might be able to do that on a very small scale for your detectors 31-Mar-20 04:21 PM that was the plan 31-Mar-20 04:22 PM good luck, hurt to read about the flaking 31-Mar-20 04:22 PM thanks 31-Mar-20 04:22 PM need some way to measure the thickness 31-Mar-20 04:22 PM a quarz thickness monitor would be nice 31-Mar-20 05:03 PM yeh just thermal evap 31-Mar-20 05:03 PM run 2-3 amps through it an it should be pretty quick 31-Mar-20 05:03 PM Aluminum coats are best at high evap rates 31-Mar-20 05:04 PM @GigaSquirrel yeah I need atomic precision with my deposition goals, thus ALD is my hammer which I judge problems with first 01-Apr-20 10:18 AM oh, lol 01-Apr-20 10:18 AM well 01-Apr-20 10:18 AM 1 µm will take quite some time, atom by atom 01-Apr-20 10:26 AM Plus ALD at home sounds intense hahaha 01-Apr-20 10:26 AM Aluminum precursors for ALD are usually pretty pyrophoric idk if I’d want to deal with them at home 01-Apr-20 10:26 AM @nmz787 can that PVC chamber you made do epitaxial MOCVD ? 01-Apr-20 10:26 AM with the right precursor gasses ofc, cause I don’t know how they would react with pvc lol 01-Apr-20 10:55 AM @mike crb the PVC chamber was specifically for FDTS monolayer application 01-Apr-20 10:55 AM For an anti-adhesion/release layer for nanoimprint lithography shims (molds/stampers) 01-Apr-20 10:55 AM Pyrophoric (or pack thereof) is why I chose AlCl3 from that ALD recipe database 02-Apr-20 10:24 PM @qualia what did your bedroom server rack cost? 02-Apr-20 10:24 PM I've been looking for one for my RF plasma setup 02-Apr-20 10:24 PM Stupidly I didn't have the forethought of needing one a few months ago when I helped a friend move, and we took one he had and donated it 02-Apr-20 10:29 PM i've seen server racks for free on craigslist 02-Apr-20 10:29 PM since they're not hot ticket items and take up space, often people just need to get rid of them 02-Apr-20 10:34 PM yea... free or like 50 bucks 02-Apr-20 10:34 PM that's the "fair price" for a rack 03-Apr-20 01:49 AM my half-height almost-fully-enclosed cagenut-compatible varian rack-on-wheels was, like, $150something from the late weirdstuff 03-Apr-20 01:49 AM half-height, fully enclosed (or fully enclosable), and on wheels are all big cost multipliers when looking for racks, but woobly old four-poster 42U things sometimes just end up in dumpsters yeah 03-Apr-20 01:49 AM i have an old 42U thing with annoying circular holes in the garage that holds the home infra and that one was free 03-Apr-20 05:05 AM Hmm, either i think I have to wait for something to show up online (local sites), or buy something without sides and hope I can find! some sheet metal for cheap to screw on as sides 03-Apr-20 05:05 AM Also pinged a few e- waste and surplus companies 03-Apr-20 06:33 AM https://hgrinc.com/?all=1&view&aisle&from&to&markdowns&newarrivals&sort&kw=ibm&per_page=24&min_price&max_price&pn=1 03-Apr-20 06:33 AM ... 03-Apr-20 06:33 AM This is what I mean, these aren't even last chance yet and I know these IBM racks... I work at IBM. They are made in the US and my friend has actually been to the place that makes them on a service call lol. 03-Apr-20 06:33 AM Like even quality racks are free to 50 bucks. 03-Apr-20 06:33 AM Its just a matter of patience, if you need something yesterday, yea I dunno buy a brand new rack for hundreds if not over a grand for something quality. 03-Apr-20 06:33 AM but ultimately they are hunks of steel people are left with after selling the stuff that was within them for tons of money likely 03-Apr-20 06:33 AM They can't be easily or cheaply shipped 03-Apr-20 06:33 AM and shipping is always worth more than the rack even considering near new price most of the time... 03-Apr-20 06:33 AM so they are worthless...most of the time... 03-Apr-20 06:33 AM Even steel scrapping them is a pain because they are a pain to move and don't compress into a dumpster well... so their weight to volume ratio SUCKS 03-Apr-20 08:06 AM I like the two-post racks 03-Apr-20 08:06 AM They look funny 03-Apr-20 11:03 AM Our makerspace doesn’t have that problem. 03-Apr-20 11:03 AM Want to discard anything metal? Wheel it into the alley. 03-Apr-20 11:03 AM Gone in 15 mins. Scrappers watch our alley like vultures. 03-Apr-20 03:44 PM @Conmega there's one like that here on Craigslist, but I was thinking the mesh looking stuff might be plastic and not metal... And I want this RF stuff to be shielded 03-Apr-20 03:58 PM @idmb there's a two post rack on Craigslist too, but I'm not trusting that to 100s of lbs of RF equipment and a vacuum chamber 03-Apr-20 03:58 PM lol 03-Apr-20 03:58 PM the lab beside me has one 03-Apr-20 03:58 PM and uses it 03-Apr-20 03:58 PM Oh, but it's much heavier duty than the ones I see on google 03-Apr-20 03:58 PM something ancient 03-Apr-20 03:58 PM but they probably have 200k worth of stuff in it 03-Apr-20 04:01 PM two-post racks are for telecom/networking equipment and other lighter-weight stuff usually, or, like, things able to be supported on their front face or in the center of their chassis 03-Apr-20 04:01 PM putting regular long servers in a two-post rack does janky center of gravity things 03-Apr-20 04:01 PM that said, if you bolt it to the floor you can definitely put many hundreds of pounds of stuff in one 03-Apr-20 04:01 PM i'd never use a two-post without bolting it down 03-Apr-20 04:03 PM ^ if you're having custom hardware built it's almost always worth buying the good cases 03-Apr-20 05:52 PM Agreed 03-Apr-20 05:52 PM Yeah I want wheels, so bolting not an option 03-Apr-20 05:52 PM All racks with IBM on them are nice racks, even if the front door is a plastic mesh it is painted with a conductive coating for shielding... We do rigorous RF testing, we actually have an anechoic/faraday chamber on site. 03-Apr-20 05:52 PM so if you have front and back doors it should be shielded 03-Apr-20 05:53 PM Hmm 04-Apr-20 01:33 PM @Applied_Ion you can draw ICP out of source zone into chamber using a bias voltage on say a sample stage? 04-Apr-20 01:33 PM @Applied_Ion can you use that for directionally sputtering or etching? 04-Apr-20 01:37 PM I mean you can extract ions from an inductively coupled plasma source using optics/extractor stages as an ion beam. That's exactly how RF ionized gridded ion thrusters work lol. In this case using the ion beam drawn from the plasma it would be a very directional source 04-Apr-20 01:37 PM You can use an immersion neutralizer filament to neutralize the beam impinging on the sample if needed as well 04-Apr-20 01:37 PM Here is an example of a gridded rf ion source used for sputtering or etching, actually very similar to what I am currently designing now except as an iodine thruster: https://ionsources.com/product-line/gridded-rficp-sources/ 04-Apr-20 01:37 PM You could make the ICP as a plasma gun source, but for highly directional sputtering or etching using an ion beam source would probably be preferable, but it depends 04-Apr-20 01:45 PM Well I got this ICP source 04-Apr-20 01:45 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/15860330954994277308534483754112-19AAE.jpg 04-Apr-20 01:45 PM It looks like maybe iso160 connection 04-Apr-20 01:45 PM Wow really nice that's awesome! 04-Apr-20 01:46 PM And "EG&G Ortec 459 Industrial Bias Supply 0-5kV NIM BIM Plug-In Module Unit" 04-Apr-20 01:46 PM Is there input for gas flow, or does it just ionize whatever background gas is there? 04-Apr-20 01:46 PM Which I'm hoping can be used to draw it out 04-Apr-20 01:46 PM Looks like there's input at the top of the bell 04-Apr-20 01:46 PM Didn't take off the metal shielding like in that eBay pic, just checked it survived shipping 04-Apr-20 01:46 PM Does it matter what sort of pump to use? I know a guy with a plasmod, residual air plasma Asher, that just uses a normal rough pump... Trivac i think 04-Apr-20 01:46 PM I've got a fomblin pump that I might be able to switch off my FIB 04-Apr-20 01:46 PM Or I've got a membrane pump with drag pump in a pump station 04-Apr-20 01:46 PM Or a currently might not work state of disrepair scroll (Edwards xds10) 04-Apr-20 01:53 PM Pump depends on the process really. Speed and vacuum level really depend on what you are trying to do, and how much process gas flow you need 04-Apr-20 01:53 PM Also, how to know of the glow is dangerous to look at? Like, x-rays or UV danger. Is there a database or do I need to look up each gas/chemical mix one at a time? 04-Apr-20 01:54 PM You won't need to worry about any x-rays at your voltage levels 04-Apr-20 01:54 PM My RF generator is listed in terms of watts 04-Apr-20 01:54 PM Do I just use the impedance of the cable to convert to volts? 04-Apr-20 01:55 PM Yep 04-Apr-20 01:56 PM you have direct access to a radiation safety officer, maybe ask them? 04-Apr-20 01:56 PM 5kv won't produce anything that can even remotely penetrate the bell jar lol 04-Apr-20 01:56 PM At least in terms of x-rays 04-Apr-20 01:56 PM Especially with a higher pressure plasma source like that. Directional beams at higher energy may start to produce some, but I don't think you would need to extract the ions at some crazy voltage if you go this route. 04-Apr-20 02:08 PM Ah so the ionization itself isn't a worry? 04-Apr-20 02:08 PM It's only extraction voltage/acceleration that would produce such rays? 04-Apr-20 02:12 PM Only if it is high enough. It's not the acceleration itself that produces the x-rays, but the interaction of particles above some energy threshold with matter 04-Apr-20 02:12 PM Also for a plasma the particle energy is not going to be all at the same energy as the excitation voltage, it will be some distribution 04-Apr-20 02:16 PM Ah, yeah i figured it was due to the interaction/crashing 04-Apr-20 02:16 PM Was mostly thinking if i just got the ICP going, could i safely stare at it 04-Apr-20 02:18 PM I'm not sure about UV, but in terms of x-rays you are probably fine 04-Apr-20 02:18 PM I actually did a study looking at simulating the energy distribution for sputtering of a DC plasma using TRIM you might be interested in. At the bottom of the page I link a bunch of papers looking at ion energies in plasma. This is for a DC glow discharge, but RF shares similar principles 04-Apr-20 02:18 PM https://appliedionsystems.com/portfolio/trim-simulation-of-sputtering-and-implantation-from-dc-glow-discharge-plasma-in-stainless-steel/ 04-Apr-20 02:18 PM The plasma source simulated is also fairly directional, and looks at sputtering, implantation depths, etc 04-Apr-20 02:18 PM The simulation files and instructions are uploaded as well if you want to do something similar with your gas and target material by modifying the input code and using the TRIM functionality from SRIM 2013 04-Apr-20 02:26 PM i tore down mechanical pump and put all the fasteners (typically inside the oiled side of pump) in vinegar or evaporust -- i'm wondering if i've removed any corrosion resistance or there wasn't any since they're always in oil? they were black, so that's just natural black oxide coating of alloy steel? 04-Apr-20 02:44 PM @Applied_Ion wow, it's gonna take me a while to digest that article and the software and equations and implications 04-Apr-20 02:45 PM Yeah lol it's fairly dense 04-Apr-20 02:45 PM Earlier you mentioned immersion neutralizer, is that just another acceleration grid but opposite polarity to soften the ion landing on the substrate? 04-Apr-20 02:45 PM I'd say even just using TRIM without a custom input is still powerful. Gives you best case ideal scenario data at least and us super easy to use 04-Apr-20 02:45 PM No, the immersion neutralizer is literally just a thermionic emission filament across the output of the beam 04-Apr-20 02:45 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/eH400-ISO-1-69B24.jpg 04-Apr-20 02:47 PM Hmm wouldn't that kill any reactivity? 04-Apr-20 02:47 PM But allow the velocity to remain?? 04-Apr-20 02:49 PM It's to neutralize the beam so you don't have charge buildup on the substrate. For etching it depends on the process, but for sputtering you don't really want reactivity I don't think, which you wouldn't get anyway using a gas like argon. 04-Apr-20 02:53 PM So depending on the gas being ionized, it can make anions or cations right? 04-Apr-20 02:53 PM So in some cases I may need positive or negative bias to pull a beam out of the source? 04-Apr-20 02:56 PM The neutralizer is only used for an extracted ion beam source, not the plasma source 04-Apr-20 02:56 PM The plasma in this case is generated in the discharge chamber, and extractors are used to accelerate ions out as a beam 04-Apr-20 02:56 PM Note this isn't necessary, it depends on your process again 04-Apr-20 02:57 PM Hrmm, aren't ions and plasma sort of the same ln this case, I mean they're both charged particles right, just different amounts of energy? 04-Apr-20 02:57 PM Are we just switching terminology when we pull ions out of plasma? 04-Apr-20 02:57 PM Or does that signify they lose energy in doing so? 04-Apr-20 02:58 PM A plasma is a neutral/quasineutral mix of ions and electrons 04-Apr-20 02:58 PM When ions are extracted from a plasma, it becomes an ion beam with a non-neutral charge 04-Apr-20 02:58 PM Heh, I'm feeling quasi stupid right now, :p 04-Apr-20 02:58 PM Is it right that ions can be positive or negative? Or is that like, liquid chemistry only, or some abstraction of reality that I've been taught? 04-Apr-20 02:58 PM /me still remembers my 5th grade teacher dismissing my statement about there being more than 3 states of matter 04-Apr-20 03:07 PM yes ions can be positive or negative 04-Apr-20 03:07 PM cation and anion are positive and negative ions, respectively 04-Apr-20 03:10 PM Yeah, so I'd need positive or negative bias to extract, depending on the chemistry 04-Apr-20 03:14 PM Ions can be positive or negative, but it depends on the source gas. Applying a negative extractor voltage won't extract negative ions for everything, actually negative ion sources are quite challenging. Note that if you ionize let's say argon, that is removing an electron, by default making the ion positive. Cesium is one of the most common negative ion beam sources, but I think you have to do some weird stuff. For my ionic liquid electrospray thruster, I can extract both positive and negative ions but this is with special molten salts comprised of like +EMI and -BF4 04-Apr-20 03:14 PM What process gas are you looking to use? 04-Apr-20 03:16 PM tldr; it's a lot easier to send energy into something to extract an electron than to give it an extra electron 04-Apr-20 03:16 PM Hmm, mostly thinking sf6 and c4f8 (for DRIE)... Argon (sputtering), residual air (ashing) 04-Apr-20 03:16 PM Stuff i haven't figured out yet for plasma enhanced atomic layer deposition 04-Apr-20 03:19 PM Ashing is just immersing the object in a plasma right? So no need to worry about ions in that case since the bulk plasma affects it. Sputtering can be with either plasma like a conventional magnetron source or ion beam source. Not really familiar with DRIE processes though 04-Apr-20 03:31 PM Yeah ashing is directly in the plasma. I was thinking the plasma was charged particles and I could draw it out of the source into a larger chamber with bias 04-Apr-20 03:31 PM Does it just expand into an adjacent chamber on it's own tho? 04-Apr-20 03:31 PM Seems like it would lose some strength as soon as it diffused out of the RF 04-Apr-20 03:31 PM Some/all/most 04-Apr-20 03:38 PM Plasma will recombine without something to excite it and keep it ionized 04-Apr-20 03:38 PM Mmm 04-Apr-20 03:38 PM Which is weird, since the plasmod Asher I've used has an ICP source and then a cylinder of glass off to the side of it 04-Apr-20 03:38 PM There's definitely some glowy stuff in the "off to the side" cylinder 04-Apr-20 03:38 PM But it's duller 04-Apr-20 03:39 PM It probably would expand out I think, at least to some extent and depending on the RF intensity and gas flow in this case. I think if you bias the substrate though like in figure 6 here it would expand out to where you need it: https://www.hindawi.com/journals/physri/2010/164249/ 04-Apr-20 03:39 PM Though in this case they use an RF bias 04-Apr-20 03:42 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191105_230410-703A4.jpg 04-Apr-20 03:42 PM The ICP source is below that cylinder 04-Apr-20 03:42 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191101_221804-6A856.jpg 04-Apr-20 03:42 PM Unless I'm wrong about the construction 04-Apr-20 03:42 PM But I thought it was always much brighter below that long chamber, just above the buttons 04-Apr-20 03:59 PM Hmm, fig 6 in that article is a bit confusing, since it lists an inner coil and outer coil 04-Apr-20 03:59 PM I thought the RF generator essentially formed the low side of a transformer coil, and the high side were the gas molecules 04-Apr-20 04:05 PM I think the major thing is it's an externally couple ICP source with an internal RF target bias 04-Apr-20 04:05 PM In some sense it is almost like coupling energy in a transformer, though a bit different 04-Apr-20 04:05 PM The plasma is really the load in this case, absorbing energy from the RF which is coupled into the plasma 04-Apr-20 04:08 PM So i guess rf bias with some DC too? 04-Apr-20 04:08 PM I can't see how simple RF on the substrate would cause attraction, unless it was out of phase with source generator 05-Apr-20 04:23 PM Attempted to cast high temp RTV (brown) to replace one of these rubber inserts (green) for inside rotary pump but it’s not nearly as hard. Anyone know what temp oil gets to inside pump? The TPU (white) are very similar hardness 05-Apr-20 04:23 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_9142-DA794.JPG 05-Apr-20 04:38 PM Did you use a release layer? Even a spray of soapy water (then letting dry), or some wax or grease 05-Apr-20 04:39 PM the release layer is just to help remove it, right? or does that harden the silicone somehow? 05-Apr-20 04:49 PM Yeah just to ease removal 05-Apr-20 04:49 PM Couldn't tell why it looked pretty rough 05-Apr-20 04:49 PM Was that just how the mold looked? 05-Apr-20 04:49 PM Or did it resist coming out? 05-Apr-20 05:10 PM oh i actually removed that one before it cured so i messed it up a bit 05-Apr-20 05:10 PM but my real concern is that it's very soft/flexible relative to the others which are flexible but hard/rubber 05-Apr-20 05:44 PM looks like Flash point of Leybold LVO 210 oil is 250C, and they list viscosity @ 40C and 100C, so guessing if i use something with > 200C melting point i'll be ok 05-Apr-20 07:30 PM Modifying a PCB by soldering 44 AWG wire... this stuff is thin... 05-Apr-20 11:29 PM @piGuy I've soldered some pretty thin stuff that was labelled motherboard repair wire... It seemed like roughly hair thickness or double that. 05-Apr-20 11:29 PM @samy seems like reasonable logic 06-Apr-20 06:16 AM @samy There is a huge variety of RTV silicone on the market, it looks like you are using the automotive gasket maker type, possibly from Permatex? 06-Apr-20 06:16 AM It is very important to get high quality ones with the right hardness(durometer) rating and temperature rating for this. Be aware that the temperature rating can be well below the "melting point" since there can be significant thermal decomposition, where parts of it is vaporized. Most manufacturers put this information on the datasheet though, and I think 200C is not that high of a requirement 06-Apr-20 06:16 AM https://www.mcmaster.com/8595k77 06-Apr-20 06:16 AM I know McMaster can overprice things, but the good stuff does not come cheap unfortunately, especially if they are made for casting. The cured hardness at Shore 65A is still a bit below usual viton gaskets, but it should be much closer than the automotive stuff, which is usually around Shore 40A only 06-Apr-20 06:16 AM So considering the price of the OEM part, I thought it would not make sense financially to invest in the proper casting RTV silicone in the first place 06-Apr-20 09:48 AM ahh, thanks Mason! 06-Apr-20 09:48 AM yeah, probably doesn't make short term financial sense, though it's interesting to be able to make parts/gaskets so i'll probably go down this rabbit hole a little longer before giving up. great info, i appreciate it 06-Apr-20 09:48 AM this whole hobby doesn't make any financial sense for me honestly 06-Apr-20 09:53 AM You can certainly search around for cheaper options. Again the market is huge and they are used for many purposes, so have to be careful 06-Apr-20 09:53 AM As far as mold release goes, I think you can get some mold release wax instead of the spray on stuff 06-Apr-20 09:53 AM I've had really good luck with the green parting wax from Fiber Glast for composite lay-ups. They've got a consistency that can fill small gaps, like between 3D print layers 06-Apr-20 09:55 AM ooh interesting, i'll check that out 06-Apr-20 09:56 AM And I think they are silicone free too. I've never used it with casting silicone though 07-Apr-20 11:10 AM Does cooling a turbomolecular pump just involve mounting a fan in close proximity to the side of it? I have a Pfeiffer tpu-40a and I understand cooling is important, but I'm not sure how to go about doing that. 07-Apr-20 11:11 AM A lot of the small ones only have a fan. Larger ones are liquid cooled 07-Apr-20 11:11 AM The one's I have dealt with just had a fan 07-Apr-20 11:12 AM But yeah one or two fans should be more than fine it it's less than say 300L 07-Apr-20 11:13 AM Yeah it's a 40 07-Apr-20 11:13 AM Thanks for the input! 07-Apr-20 11:13 AM I think we have a small 100l one with just a large PC fan on it 07-Apr-20 11:15 AM even for >1000L/s it's not uncommon to just put a fan on instead of liquid cooling, often the liquid cooling loops are just one heatsink directly on the exterior, rather than an intricate solution. 07-Apr-20 11:16 AM my ext255h (230L/s) does quite alright with a random parts-bin 120mm PC fan it, the little drive controller gets hotter than the rest of the thing easily 07-Apr-20 11:16 AM heating is a function of gas load, though, so if you're working with a process gas of some kind and not just maintaining a vacuum you may want/need watercooling 07-Apr-20 11:27 AM Yeah used to do xenon and the water loop would get warm. Now with condensable stuff and lower mass flow they don't need much cooling. Water is mostly used because its there. And also makes the cleanroom not as hot 07-Apr-20 11:46 AM And nobody likes fans blowing around optical tables 07-Apr-20 11:47 AM I wish it was my main issue when I was doing optics... No temperature control was way more of a pain 08-Apr-20 03:41 PM Anyone got literature on the MKS 270 'signal conditioner'? I see a D15 on the back, which lines up with Granville Philips convectron cables, but maybe it's for the MKS Barotron? Anyone know? 08-Apr-20 03:46 PM not 270D? assume you saw that on google? 08-Apr-20 03:46 PM 270B, as a matter of fact 08-Apr-20 03:50 PM https://sites.fas.harvard.edu/~phys191r/Bench_Notes/A6/BaratronController.pdf 08-Apr-20 03:50 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-CFF68.png 08-Apr-20 03:50 PM from back when MKS was a respectable company lol 08-Apr-20 03:51 PM Fantastic! Thanks so much! 08-Apr-20 03:51 PM I'll have to see if my old little Barotron works with this thing. I can see which versions of that sensor work with it, but I'll have to check my unit tomorrow. Right now it's 'meter' is this crazy rackwide thing that's honestly too much, and minimizing it would be great. 08-Apr-20 08:09 PM Woot, I've finally fully dismantled all vacuum components from the Trivac! Derusted and cleaned everything...need to order two "shaft sealing rings" I busted in the process (manufacturer seems to be Stefa) which have some hard metallic rings and coils inside, was hoping to just make them at home but looks like it might be overmolded onto steel 09-Apr-20 12:56 AM @samy how about that weird nipple thing you were trying to cast? 09-Apr-20 05:41 AM hmm 09-Apr-20 05:41 AM iirc kanthal works so well because of the oxide layer it forms 09-Apr-20 05:41 AM so how about heating with kanthal in vacuum? 09-Apr-20 05:41 AM because you can get the coils for vaping for really cheap 09-Apr-20 08:04 AM Hello! I'am looking for a sensor to measure thickness (pvd application) does anyone know where I could find one ? I was thinking about quartz crystal sensors (I don't know if there is any other tech for that purpose) and do you know the cost of such measurement systems ? I would rather go without one (to start off) if I can't find any affordable option. thanks a lot ! 09-Apr-20 08:04 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/images-D3FF7.jpg 09-Apr-20 08:06 AM Ususally those passthroughs/holders go for a good amount of money on the used market... I think I got lucky at one point and scored one for like 150 bucks or so... but there are a few up for like 500 dollars right now... 09-Apr-20 08:06 AM I know some here have been experimenting and thinking about the idea of making home-brew sensors with a standard feedthrough and using cut open quartz crystals, but I know these generally have cooling blocks behind them so life-span on homebrew might not be great 09-Apr-20 08:13 AM Yeah I was shocked to see the price, would you happen to have a good set of keywords or websites I could use to do my research on ? For now I have just had some good results on Alibaba but at prices way beyond what I am willing to invest (around a thousand bucks) 09-Apr-20 08:13 AM Thanks for the answer, really cool to know that some people are trying to make that piece by themselves 09-Apr-20 10:08 AM @nmz787 i think one of my 3d prints will work for that due to the smoke point of the recommended oil vs the melting point of the plastic 09-Apr-20 10:08 AM but i'm going to experiment and just throw it in the oil and heat it up and see at what point it begins to deform 09-Apr-20 10:50 AM though i may look around for some higher temp silicones as casting seems interesting 09-Apr-20 12:09 PM @Epilogis https://hackteria.org/wiki/Wild_openQCM 09-Apr-20 12:09 PM DIY version seems way better than buying used, unless you're really in a hurry 09-Apr-20 12:26 PM @nmz787 Oh cool, thank you !! 09-Apr-20 12:26 PM To be fair even if I was in a hurry, saving a thousand bucks is a good enough reason to take time 09-Apr-20 12:49 PM @Epilogis depending on your pressure target, feedthrough can be as simple as black rubber laboratory stopper 09-Apr-20 12:49 PM Use a drill press to push a stiff steel wire through (like piano wire) 09-Apr-20 12:59 PM That's a good idea, I was thinking about using epoxy and do a first iteration of the machine even if it outgass and it is not easily removable, it would do a good proof of concept before I go into full metal or something sturdier, but I like your idea it might come in handy one day 09-Apr-20 01:12 PM Just make sure to use something like torrseal epoxy, aka hysol ea 1c 09-Apr-20 01:12 PM https://www.amazon.com/dp/B000B631G8/ 09-Apr-20 01:12 PM Also, the instructions on the box for mixing is not the same as the internet instructions (from the manufacturer) 09-Apr-20 01:12 PM Mix by weight at 100:44 parts, or by volume at 2.5:1 09-Apr-20 01:23 PM Got it, I have some JB weld on hand and used it for some projects any thoughts on that? 09-Apr-20 02:06 PM Some people use that 09-Apr-20 02:06 PM Should work for relatively low vacuum at least 09-Apr-20 02:06 PM Presumably you aren't targetting lower than around a millitorr or so 09-Apr-20 02:06 PM I.e. 10^-2 torr 09-Apr-20 03:14 PM That openQCM is pretty good stuff gonna repost that to resources if you don’t mind @nmz787 09-Apr-20 03:17 PM Hehe you beat me to it 09-Apr-20 03:17 PM I have a bunch of crystals I bought to try it out... And have a bunch of arduinos, esp8266, maybe esp32, raspi zero, etc... But haven't got around to building a generator. 09-Apr-20 03:17 PM I have rubber with wire feedthrough on my vapor deposition chamber though, so I could connect one easily at the moment 09-Apr-20 03:17 PM Since I'm trying to basically deposit a monolayer of Teflon, I was hoping to use a multimeter and watch for an increase in resistance 09-Apr-20 03:17 PM But haven't gone out to the shared lab where that is 09-Apr-20 03:17 PM Since virus 09-Apr-20 03:24 PM very curious to hear results if you do make/use one. would really add a nice element to people’s homemade deposition setups if they could get accurate film thickness without dropping ridiculous money on commercial qcm system 09-Apr-20 03:26 PM My goal is to do atomic layer deposition, so eventually I might even be able to plot the step character for each layer added, and do some statistics on the variation as loading increases 09-Apr-20 03:26 PM (thinking in terms of the crystal changing) 09-Apr-20 10:12 PM @nmz787 Ok cool thanks! Yeah I am not planning on getting too low, 10^-2 torr seems reasonable for what I want to do 10-Apr-20 10:22 AM i accidentally exploded the diaphragm valve on the Trivac cleaning it with compressed air...oops 10-Apr-20 10:42 AM if anyone wants me to break stuff for them, let me know 10-Apr-20 10:49 AM hopefully i can just press it back together 10-Apr-20 10:49 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-0F2E4.png 10-Apr-20 12:40 PM @samy it isn't obvious as to whether you broke anything in that pic 10-Apr-20 12:41 PM true, i think it was just connected via adhesive 10-Apr-20 12:41 PM it was the only component that seemed to use adhesive (everything else is torn down to smallest component parts) 10-Apr-20 12:41 PM i threw it in the vise, we'll see what happens when i reassemble 11-Apr-20 12:00 AM Joined the server. 11-Apr-20 11:37 AM I'm thinking about getting an x-ray machine for noninvasive inspection of devices I've built. Anyone know how hard it is to legally do x-ray inspection in a home lab? 11-Apr-20 11:37 AM Thats going to depend on the state you’re in 11-Apr-20 11:38 AM WA 12-Apr-20 01:41 AM Is ultimate pressure just another way to say ultimate leak rate? 12-Apr-20 01:55 AM I sanded and polished the plastic bell jar seal on my CVD chamber today, and almost hit 99mTorr.. probably would have if I would've let it pump for another 10 minutes 12-Apr-20 01:55 AM But apparently I need to get down to the single digit mTorr, according to previous recipes 12-Apr-20 01:55 AM The only places that I can think might be leaking now are the holes where the rubber stoppers are shoved through the bell jar 12-Apr-20 01:55 AM The other guy who previously did a little work on the chamber just used sticky-tack (i.e. the stuff you use to affix paper posters to your walls without thumbtacks) to seal the edge, though I'm not sure it's doing anything or if he was just trying things early on and it never got removed 12-Apr-20 01:55 AM I can only think of replacing the belljar with a plate, to exclude it from the equation 12-Apr-20 03:12 AM ultimate pressure would be your leak rate (which is never zero) and your outgassing rate combined 12-Apr-20 03:12 AM doing a blank-off test can certainly be helpful, if that's what you mean 12-Apr-20 03:20 AM Ultimate pressure is a combination of leak + outgassing rate (gas load) and your pumping speed 12-Apr-20 03:20 AM it's proportional to Gas load over pumping speed 12-Apr-20 03:28 AM oh that too yeah 12-Apr-20 03:36 AM Which is why you need thousands of liters per second to pump out bigger chambers, higher surface area gives higher gas load due to outgassing 12-Apr-20 09:12 AM Not to mtorr ranges though 12-Apr-20 09:14 AM yeah, right 12-Apr-20 09:14 AM outgassing is pretty much not an issue in those ranges unless you're vacuuming a cup of water 12-Apr-20 09:34 AM Yeah. It’s mostly the “compression ratio” of your pump 12-Apr-20 09:34 AM I do know from experience that with a 10s of litres pvc chamber, when it had just been solvent welded the gas load was much higher than a few weeks later. 12-Apr-20 09:38 AM well, solvent loaded plastics aren't far off from a cup of water in your chamber 12-Apr-20 09:55 AM You hit 1 torr almost instantly even with a tiny scroll pump though 12-Apr-20 09:57 AM yeah, outgassing gets worse with lower pressure 12-Apr-20 09:58 AM Barely, it's more that outgassing is typically a fixed small flux which is more likely to dominate at lower pressures 12-Apr-20 10:38 AM And baking makes it worse for non water based gas loads to a certain point. 12-Apr-20 10:41 AM Yeah baking my sewer pipe would not go well 12-Apr-20 12:28 PM Has anyone here actually tried making their own mechanical pump, just for fun? 12-Apr-20 12:28 PM Heh, I've got a sewer pipe too for a chamber 12-Apr-20 12:28 PM Seems like the outgassing in certain cases would end at some point, right? 12-Apr-20 12:28 PM Outgassing, not permeation 12-Apr-20 12:29 PM Well not really with plastic 12-Apr-20 12:29 PM the walls of your chamber are slowly eroding into the void 12-Apr-20 12:31 PM Just the plasticizers that aren't bonded? 12-Apr-20 12:31 PM (covalently) 12-Apr-20 12:32 PM bonds are probabilistic, there's some rate of detachment and then when a particle gets free it has some probability of sticking to another wall or bouncing down to the vacuum pump and out 12-Apr-20 12:32 PM Well but temperature is the major reason bonds are made or broken, without some form of radiation 12-Apr-20 12:33 PM Has anyone here actually tried making their own mechanical pump, just for fun? There was a guy in Reddit making his own turbo 12-Apr-20 12:33 PM both are "the same" 12-Apr-20 12:33 PM it's just energy 12-Apr-20 12:33 PM Sure 12-Apr-20 12:33 PM So at room temp, a bunch of stuff is FAR from being likely to break bondage 12-Apr-20 12:34 PM no 12-Apr-20 12:34 PM any material you can smell has stuff flying off it all the time 12-Apr-20 12:34 PM I can't smell stainless steel ever 12-Apr-20 12:34 PM and that's why stainless can go uhv 12-Apr-20 12:35 PM My point was, couldn't a huge chamber be pumped by a small pump and just take like a month to get to high vac? 12-Apr-20 12:35 PM LIGO was pumped by proportionally "small" pumps (still huge) 12-Apr-20 12:35 PM but if you only had one of them I think you'd never make it still 12-Apr-20 12:35 PM ahh 12-Apr-20 12:35 PM Stainless: 3 x 10-12 Torr-Liter/s/cm2 PVC: 2E-8 12-Apr-20 12:35 PM https://www.mtm-inc.com/av-20100827-plastics-in-vacuum-applications.html 12-Apr-20 12:35 PM so you can have four orders of magnitude more surface area of stainless than pvc 12-Apr-20 12:35 PM to do this "fairly" you'd need to have a ton of really bad pumps on that huge chamber though 12-Apr-20 12:35 PM because the particle conductivity will be limiting far before the pump's speed limits 12-Apr-20 12:41 PM Hmm, but isn't the conductivity just gonna make things take longer? 12-Apr-20 12:41 PM That's effectively just the diameter of exhaust channels, right? 12-Apr-20 12:41 PM Giving more statistical chance of a particle bouncing around going "down the drain"? 12-Apr-20 12:43 PM No 12-Apr-20 12:43 PM Diameter and length, yes 12-Apr-20 12:43 PM You will get pressure gradients 12-Apr-20 12:43 PM ^ 12-Apr-20 12:44 PM Sure, gradients make sense 12-Apr-20 12:44 PM Also why pressure sensor placement is importnat 12-Apr-20 12:44 PM I guess you're saying the conductance would be lower than the outgas rate?? 12-Apr-20 12:44 PM Yeah 12-Apr-20 12:44 PM 4 orders of magnitude more surface area is a lot 12-Apr-20 12:45 PM So torr liters per second per cm-sq 12-Apr-20 12:45 PM How the heck do I make that sensible 12-Apr-20 12:45 PM Is a torr-liter just the pressure in a given liter of volume? 12-Apr-20 12:45 PM So torr liters per sec per sq cm is the pressure added per volume of gas per second for each sq cm of surface area that volume has? 12-Apr-20 12:49 PM PV = nRT Torr Liter = nRT = amount of gas normalized to temperature 12-Apr-20 12:49 PM Torr liters per second is like the mass flow rate 12-Apr-20 12:49 PM And gas load is mass flow rate per unit area 12-Apr-20 12:50 PM Yeah. In short torr liters per second per cm-sq = particles / second / area 12-Apr-20 12:59 PM I can't see any progress on a homemade turbo yet 12-Apr-20 01:02 PM It's just way too much effort and will likely cost quite a bit more than just buying a used one. The precision required in the machining and dynamic balancing of the rotor is very hard to achieve at home 12-Apr-20 01:03 PM Oh yeah it would have to be purely for fun 12-Apr-20 01:05 PM This is most certainly NOT how you should do it 12-Apr-20 01:05 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-145CB.png 12-Apr-20 01:07 PM So for PVC and a chamber of 10"*32" 12-Apr-20 01:07 PM ((10 inches * pi * 32 inches) to sq cm)((2(10^-8)) ) 12-Apr-20 01:07 PM 1.297×10^-4 12-Apr-20 01:07 PM This is most certainly NOT how you should do it @Mason_Yu But it worked, didn't it? 12-Apr-20 01:07 PM So that's just torr liters/sec 12-Apr-20 01:07 PM It most certainly didn't @GigaSquirrel, that was for an Edwards turbo. I guess he learnt some lessons to make the Welch turbo repair successful 12-Apr-20 01:08 PM So now to get leak rate, I need to multiply out the volume of the chamber? 12-Apr-20 01:08 PM I mean pressure differential 12-Apr-20 01:10 PM if you close the valve to your pump then turn it off 12-Apr-20 01:10 PM Yeah 12-Apr-20 01:10 PM how quickly does your chamber rise back to atmosphere ? 12-Apr-20 01:10 PM and can you hear any leaks ? 12-Apr-20 01:10 PM I posted homemade turbo dude in the #machining channel 12-Apr-20 01:10 PM After 3 weeks, starting at 5 torr, it was at like 398 torr 12-Apr-20 01:10 PM 3 weeks of sitting off, unused 12-Apr-20 01:10 PM Isolation valve closed 12-Apr-20 01:10 PM With mks901p, at 0.1 torr, I saw an increase of about 0.005 torr per second 12-Apr-20 01:10 PM Or maybe slightly less 12-Apr-20 01:10 PM That was yesterday after sanding and polishing the plastic bell jar "head" 12-Apr-20 01:10 PM Which seems to be a softer plastic from what I could tell sanding it 12-Apr-20 01:10 PM Also it's clear so I'm guessing acrylic 12-Apr-20 01:14 PM Oh 12-Apr-20 01:14 PM 0.005 torr per second "bad but not insanely terrible" 12-Apr-20 01:15 PM It seems to be bad enough from what I can tell for the CVD recipes I've been reading 12-Apr-20 01:15 PM (which are obscurely written and require a lot of reading in between the lines) 12-Apr-20 01:15 PM But 0.005 is still an order of magnitude above 1.297×10^-4 12-Apr-20 01:15 PM (which I'm still not clear, since that's torr-liters/sec... Do I need to multiply out the liters to get pressure change get second?) 12-Apr-20 01:23 PM Multiply the outgassing rate with the area of your chamber 12-Apr-20 01:23 PM then divide by your pumping speed 12-Apr-20 01:23 PM to get your ultimate pressure 12-Apr-20 01:23 PM your pumping speed will be 1/(1/PumpSpeed + 1/Conductance) 12-Apr-20 01:23 PM but using 1/pumpseed puts a lower bound on your ultimate pressure 12-Apr-20 01:26 PM I multiplied the outgassing rate times surface area to get 1.297*10^-4 12-Apr-20 01:26 PM But that has the "liter" unit still present 12-Apr-20 01:26 PM I also don't know the pumping speed 12-Apr-20 01:27 PM what model of pump do you have? 12-Apr-20 01:27 PM And mostly just am interested in comparing the leak rate observed with what the outgassing would present 12-Apr-20 01:27 PM Not sure on the pump 12-Apr-20 01:28 PM well the liter unit present is typically divided out by the "liters/second" of the pumping speed 12-Apr-20 01:28 PM Chamber is 41.19 liters 12-Apr-20 01:28 PM that usually doesn't come up 12-Apr-20 01:28 PM Huh 12-Apr-20 01:28 PM Well if I multiply them 12-Apr-20 01:28 PM (1.297*10^-4) *41.19 12-Apr-20 01:28 PM Answer is 0.00534 12-Apr-20 01:28 PM Soooo 12-Apr-20 01:28 PM Suspiciously close to what I measured with sensor 12-Apr-20 01:28 PM Huh, well, as long as no one sees any glaring problems with my math, it seems like I'm pretty much at the limit of this chamber 12-Apr-20 01:28 PM In terms of leakage 12-Apr-20 01:31 PM 99 mtorr? 12-Apr-20 01:32 PM More concerned with leak rate to be honest 12-Apr-20 01:32 PM Since the recipe I believe is pump down to as close to 1 mTorr, the raise to 30-500mTorr, then let it react and repeat 12-Apr-20 01:32 PM So if I'm leaking that much, it's not much of a relative"steady state" 12-Apr-20 02:12 PM Hmm, maybe I shouldn't have multiplied the torr-liters/sec by liters, but divided it 12-Apr-20 02:12 PM That would push the result in the other direction, meaning I've still got some big physical leaks present 12-Apr-20 07:09 PM does it matter much if i use 3A vs 4A zeolite? is there a preference? 12-Apr-20 09:04 PM Is this zeolite still okay? Looks a bit burnt but not sure if still usable. This was in foreline trap i got on ebay, hadn’t used it yet 12-Apr-20 09:04 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_9200-4761F.JPG 12-Apr-20 09:46 PM some of that looks like activated carbon pellets? not sure i have ever seen black zeolite but it probably exists...just think carbon might be more likely 12-Apr-20 10:29 PM maybe those are burnt? i had a bunch of burnt ones that looked like the black ones 13-Apr-20 06:05 AM @Electric_ionland (at.lougrims) yeah I am on this discord, I pop in and out (saw your tag in the resource section lol). Very cool to see you have joined the vacuum hackers discord as well! 13-Apr-20 07:53 AM Qualia convinced me. Not much hacking at home on my side (yeah apartment life) but always fun to see what people in adjacent fields are doing 13-Apr-20 10:53 AM Yeah, lots of very interesting and impressive projects going on in here for sure. Definitely the place to be if you work with any high vacuum stuff at all! 13-Apr-20 12:40 PM Does anyone have expereince servicing diffusion pumps? I acquired an ESEM which has two Varian M-2 pumps that were a bit abused. There are a lot of (what look to be) carbon deposits on the nozzles. 13-Apr-20 12:40 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_2929-B897E.jpeg 13-Apr-20 12:40 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_2932-0FE7F.jpeg 13-Apr-20 12:41 PM that's just burned oil 13-Apr-20 12:41 PM take some steel wool and take it off 13-Apr-20 12:44 PM Yeah I just cleaned mine up with stainless steel wool 13-Apr-20 12:44 PM It's pretty stubborn stuff. Do you know any good solvents that could help soften it first? 13-Apr-20 12:44 PM Ordered like 3 or 4 different "grits" or whatever they call it for wool 13-Apr-20 12:44 PM I just used alcohol and acetone I recall 13-Apr-20 12:45 PM but the solvents are for the oil and tar 13-Apr-20 12:45 PM Paint stripper could also work, but you'll want to finish with acetone and the alcohol 13-Apr-20 12:45 PM won't help you with the coal 'tho 13-Apr-20 12:46 PM Elbow grease for that 13-Apr-20 12:46 PM just try whatever you want, no solvent will ruin the stainless 13-Apr-20 12:47 PM That oil looks fresh compared to the flakes in it, and the surface condition of the metal 13-Apr-20 12:48 PM Thanks for the advice guys. I'll try that out when I get things ordered in 13-Apr-20 12:48 PM From what I've been told, the pumps haven't been run for a few years now 13-Apr-20 12:49 PM https://www.amazon.com/dp/B01NCQCPOI/ and https://www.amazon.com/dp/B00B1FZEW2/ 13-Apr-20 12:49 PM https://www.amazon.com/dp/B016QW5CEE/ 13-Apr-20 12:49 PM I bought all three of those :p 13-Apr-20 12:53 PM Thanks for the recommendations, I'll have to check what's avaialble at amazon.ca though! 13-Apr-20 03:03 PM How are SEM filament-to-wehnelt bias resistors usually implemented? It's not usually a fixed vacuum resistor, is it? 13-Apr-20 03:10 PM I believe it may be fixed, but that's just from memory of a diagram I once saw 13-Apr-20 03:10 PM And that could have been a demo circuit 13-Apr-20 03:10 PM Not anything HiFi 13-Apr-20 03:11 PM https://media.springernature.com/original/springer-static/image/chp%3A10.1007%2F978-3-319-98482-7_2/MediaObjects/420088_1_En_2_Fig5_HTML.png e.g. I have no idea where to find a high voltage (vacuum) potentiometer suitable for this, or if this is normally solved with a floating bias supply, or something else 13-Apr-20 03:11 PM seems like running 30+kV up to a k'nob on a console would be Noise Pickup City, and also kind of dangerous too 13-Apr-20 03:14 PM Maybe an active voltage divider, with a fixed high side in the vacuum? 13-Apr-20 03:24 PM huh maybe 13-Apr-20 03:24 PM cc @AdamMcCombs you might know something about this 13-Apr-20 05:01 PM Any suggestions or recommendations on ebay mass-flow controllers for vacuum applications (what to get and what not to get)? The job is to feed argon into the chamber at the slow controllable rate. If it's digital and not analog - it would be perfect. 13-Apr-20 05:04 PM What leak rate? Into what level of vacuum? 13-Apr-20 05:08 PM @idmb ~0.1-20mTorr vacuum, 0-100sccm rate? 13-Apr-20 05:52 PM Hmm. Too high for a proper leak valve to be necessary 13-Apr-20 06:01 PM @idmb Too high pressure? Where is the limit for leak valve? Is it used in higher vacuum? I assume these pressures might require slowing down turbopump. 13-Apr-20 06:07 PM That pressure level isn't turbo level 13-Apr-20 06:07 PM I got a 0-200sccm MFC for $25 a few months ago 13-Apr-20 06:07 PM It has digital and analog control I believe 13-Apr-20 06:23 PM a leak valve will work at that level but is way overkill. They leak ~1E-7 torr L / s 13-Apr-20 06:23 PM they're quite fragile too and usually only manual control 13-Apr-20 06:24 PM My KF leak valve can do wayyy higher than that 13-Apr-20 06:24 PM I can get my 41L chamber up to atmospheric in like 20-30 seconds or so 13-Apr-20 06:26 PM Yeah I'm talking minimum leak rate 13-Apr-20 06:26 PM leak valves are for precision 13-Apr-20 06:26 PM zepto doesn't need enough precision to need one 13-Apr-20 08:02 PM So I assume precision leak valves and MFC are different things? And ~100sccm is something which is expected to be handled by MFC? I.e. leak valves for deep vacuum, and MFC for low vacuum? 13-Apr-20 08:04 PM Yeah, precision leak valves have two optically flat sapphire pressed together and an armature to adjust the pressure on them, varying leak rate precisely. They are generally bakeable and good up to UHV levels 13-Apr-20 08:23 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200413_232246-07898.jpg 13-Apr-20 08:23 PM @qualia Here's the filament and Wehnelt bias circuit on my SEM, it appears the bias resistors are fixed 13-Apr-20 08:58 PM ooh that's excellent, thank you! 13-Apr-20 08:59 PM The lines that goes out from the ground side of the bias supply to the console is just to some current sense circuit (I think) 13-Apr-20 08:59 PM I'm tempted to replace this enormous power supply box with a modern, tiny and potted power supply instead, given it's not working at the moment 13-Apr-20 09:04 PM it looks big and linear and probably stable as hell when it's working 13-Apr-20 09:04 PM maybe easy to service too, though i have no sense of scale here 13-Apr-20 09:04 PM non-trivial potted power supplies drive me nuts 13-Apr-20 09:06 PM It's not that easy to service really... As all oil-filled tanks are... It developed a leak during transport 13-Apr-20 09:12 PM oh.. oh. hm 13-Apr-20 09:12 PM i have not yet had to deal with that kinda hassle 13-Apr-20 09:12 PM curiously, both of my 30kV power supplies aren't under any kind of oil, so i wonder why that is there.. maybe the filament transformer really needs it 13-Apr-20 09:12 PM my thyratron filament transformer, tmk, is also 30kV isolated but doesn't need to be under oil. shrug 13-Apr-20 09:12 PM (but it's also huge) 13-Apr-20 09:15 PM I guess we have the same thyratrons? 13-Apr-20 09:15 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20190615_230651-F9C7F.jpg 14-Apr-20 10:07 AM I believe Teledyne E2V still make those. They are deuterium Thyratrons. Probably cost an arm and a leg. 14-Apr-20 10:10 AM Or $75 on eBay 14-Apr-20 10:10 AM https://www.ebay.com/itm/CX-1538-DEUTERIUM-THYRATRON-TUBE-designed-for-positive-voltage-holdoff/333485045230 14-Apr-20 10:10 AM Actually upped the price a bit since then 14-Apr-20 10:10 AM https://accelconf.web.cern.ch/p83/PDF/PAC1983_2970.PDF 14-Apr-20 10:10 AM https://www.ebay.com/itm/CX-1538-DEUTERIUM-THYRATRON-TUBE-designed-for-negative-voltage-holdoff/362177071127 14-Apr-20 10:10 AM Was able to get one good pulse out of one of these at a mere ~10kV and a thyristor based trigger, but then I made some mistakes when switching to a IGBT based trigger and ended up frying 3 of the IGBTs 14-Apr-20 10:26 AM With some luck, I might have the chance to upgrade to some high rep rate ceramic thyratrons capable of more current and higher voltage, also originally intended for driving LINACs 14-Apr-20 10:48 AM yeah, same thyratrons :D 14-Apr-20 10:48 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200414_104655-3F29F.jpg 14-Apr-20 10:48 AM i also got two of his aerovox pulse caps, and one of the chonky filament transformers 14-Apr-20 11:13 AM Just saw the electron microscope stuff from ealier. Does anyone know a good supplier for AEI base for thermionic cathodes? Preferably without the filament installed. 14-Apr-20 08:20 PM On eBay they are cheap. From the manufacturer I would guess at least $500 each. 16-Apr-20 12:29 PM spot welding tungsten to 316L stainless is difficult 16-Apr-20 12:29 PM seems like the stainless 'melts' around the tungsten, mostly? 16-Apr-20 03:06 PM Also, anyone have any brand/model recommendations for surplus ion pumps? 16-Apr-20 03:19 PM Hmm, I think Adam basically just said generally that ion pumps can go bad from sitting in air... But another expert I know said "as long as it's not sitting out in the rain, atmosphere shouldn't hurt" 16-Apr-20 03:19 PM I know from duniway's marketing, their star line of models seems better than otehrst, but idk how much that's just marketing 16-Apr-20 03:21 PM yeah it seems like ion pumps aren't a thing i get to cheap out on 16-Apr-20 03:23 PM I've seen some reasonable prices in the past 16-Apr-20 03:23 PM i'm putting together an electron gun column and, like, i've managed 10^-8 in a large chamber with just turbopumping.. but it seems like most SEMs and such will have at least one ion pump dangling off the side too 16-Apr-20 03:23 PM Well, auctions anyway 16-Apr-20 03:23 PM yeh 16-Apr-20 03:23 PM Well my SEM has no ion pump 16-Apr-20 03:23 PM if you're okay with only -10 then I think most ion pumps should do fine? 16-Apr-20 03:24 PM yeh.. was just curious if anyone had any particular brand allegiances 16-Apr-20 03:27 PM Lol, I'm getting hits for high heel shoes when i search 'ion pump star' on eBay 16-Apr-20 03:28 PM think 'starcell' works too 16-Apr-20 03:29 PM varian, agilent and perkin elmer are all I've seen around here 16-Apr-20 03:29 PM have a giant perkin elmer one being used as a weight rn 16-Apr-20 03:29 PM and a starcell in a cupboard 16-Apr-20 03:29 PM turbos are also supposed to be kept running aren't they? 16-Apr-20 03:29 PM why are you only 10^-8 with your turbo? 16-Apr-20 03:31 PM i don't have enough valving in place to keep it running indefinitely 16-Apr-20 03:31 PM but, i mean, yeah, it does stay running when the chamber's in use 16-Apr-20 03:31 PM But in terms of buying used ones 16-Apr-20 03:31 PM we and everyone else I know just leaves them on shelves when not in use 16-Apr-20 03:31 PM for years at a time 16-Apr-20 03:31 PM same with the ion pumps 16-Apr-20 03:34 PM also why only 10^-8? i have no idea. i don't have the heaters to bake everything at once, so water might be the problem still, but really i have to get the two RGAs back on the system to figure out why (and see if i can even get the new one working) 16-Apr-20 03:34 PM there's two KF16 ports i desperately want to get rid of that probably aren't helping matters either 16-Apr-20 03:35 PM ah, small pump + big chamber + kf would do it 16-Apr-20 03:35 PM but with 85 L/s turbo on a ~50L chamber we still hit low -9 high -10 with nothing else. takes a couple weeks after exposure to atmosphere, but no baking or anything for 5+ years 16-Apr-20 03:35 PM all conflat with copper gaskets of course 16-Apr-20 03:39 PM ah yeah that was 10^-8 after like a week of pumping 16-Apr-20 03:39 PM shrugg 16-Apr-20 03:39 PM it's all coming apart soon anyways 16-Apr-20 03:40 PM I have one small chamber at 2E-10 with a 300L/s turbo. 16-Apr-20 03:50 PM Hmm, I think my ion gun gets to 10-8 with ion pump and turbo not turned off in like 9 months 16-Apr-20 03:50 PM But the display is in pascals so I could be wrong, I don't calculate the conversion too often 16-Apr-20 03:52 PM what kind of backing pressure? mines 5E-3 to 2E-2 torr 16-Apr-20 03:53 PM No idea 16-Apr-20 03:53 PM My gui doesn't show that, only shows chamber and gun pressures 16-Apr-20 03:53 PM and what model of turbo? 16-Apr-20 03:53 PM for any reasonable chamber size made of stainless with no load you should pretty easily hit -9/-10 just using forevac pressure & compression ratio 16-Apr-20 03:56 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200130_112619-F7F86.jpg 16-Apr-20 03:56 PM I know my fomblin needs changed 16-Apr-20 03:56 PM So i guess foreline pressure could be bad 16-Apr-20 03:56 PM I have a kf25 tee and kf25 to 16... But I think I lack a blocking plate, so couldn't immediately connect my mks901p 16-Apr-20 03:56 PM Probably worth it to try figuring out what pressure sensor the system uses 16-Apr-20 03:59 PM is that iso or cf? 16-Apr-20 03:59 PM Hmm, not sure :p 16-Apr-20 04:00 PM it can't out-pump the iso leak below -8 according to specs 16-Apr-20 04:00 PM cf does -9 16-Apr-20 04:00 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190927_142419-A9E5E.jpg 16-Apr-20 04:01 PM yeah that's iso 16-Apr-20 04:01 PM Thing in red looks like it has a hose clamp! 16-Apr-20 04:01 PM How did you get to -10 ? 16-Apr-20 04:01 PM I thought cf was the best out there 16-Apr-20 04:03 PM cf can go lower but maybe the pump can't? 16-Apr-20 04:03 PM yeah 16-Apr-20 04:03 PM different pumps have different "compression" ratios which is inlet to outlet pressure ratios 16-Apr-20 04:04 PM I'm not sure why the load lock has so many dampeners, I guess since it doesn't have a magnetic levitation bearing 16-Apr-20 04:04 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190927_142538-05444.jpg 16-Apr-20 04:04 PM chamber's pretty darn big, idk the volume 16-Apr-20 04:04 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190927_142042-2C15E.jpg 16-Apr-20 04:04 PM Good bit of volume below the box of gloves, too 18-Apr-20 02:47 PM ouhhh 18-Apr-20 02:47 PM that hurts 18-Apr-20 02:47 PM it was warm all day and then it rained 18-Apr-20 02:47 PM humidity >90% 18-Apr-20 02:47 PM this is what it looks like when I open the valve to my foreline pump 18-Apr-20 02:47 PM https://www.youtube.com/watch?v=QzSqwSrdQ5M 19-Apr-20 01:05 AM magic smoke 19-Apr-20 06:41 AM Does anyone happens to be using one of the IMM100 series of chip from infineon to control a turbomolecular pump ? 20-Apr-20 10:50 AM I haven't heard of that chip. I have two Varian TV 301 Navigator pumps but do not have the original driver, so have started to build one myself. I have done SPWM generation with dead-time-insertion in C, using all timers of an AtMega328. A second MCU controls spinup/down by adjusting frequency and amplitude. The amplitude is managed by setting the intermediate voltage. After the atmega i simply use 3 ncp5106 half-bridge-drivers with MOSFets. So far I have tested the setup with an old induction motor. I have had some challenges with the turbo, so I haven't yet spun it up to full speed yet, as I don't have a suficient forepump ready yet I can write some documentation if you like 20-Apr-20 11:25 AM Sounds very nice ! I am trying a similar approach, I have a Turbovac 50, I first started off building a three phase inverter which was working great, then someone told me it would be very difficult to control a bldc by measuring the back EMF so I went with the IMM100 approach which is a all in one chip used to drive turbopumps (it includes the mosfets, back emf measurements and everything needed) but turns out after months of work and I've finally got to dismounting the pump it's an induction motor so back to the drawing board. I took a lot of inspiration from this project : https://hackaday.io/project/156682-open-source-turbomolecular-pump-controller and so far I am at the point where my 3 phase inverter is working but I have no routine to start the turbopump or ramp its speed up yet, but working on it. I am using an STM32F103 and 2 timers to create the required waveform, looks like this atm : 20-Apr-20 11:25 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20191001_211359-33D2A.jpg 20-Apr-20 11:25 AM I'd really like to know more on how you manage to spinup and spindown your induction motor 20-Apr-20 11:39 AM I'd really like to know more on how you manage to spinup and spindown your induction motor @Epilogis Sure, it's an easy thing to do. Were only talking about building a Variable Frequency Drive with target frequencies 10-20 times larger than usual. Back-emf is common to many electric motor types. It is most known for in BLDC/PMSM motors, as it may be utilised for their control. Essentially it just means that the rotor induces a voltage that acts against the one that is applied. The back-emf is simply propotional to the speed of the motor. As an induction motor has slip, it can be started with a small frequency. A synchronous (BLDC) motor would fail to start, wheres an induction motor is asynchronous and will produce torque. My TV 301 is rated for 963Hz and 75 Volts. I simply start by applying about a twentieth of that and then simply ramp up both frequency and amplitude of the 3-phase voltage together and of course do it slowly (several minutes) For spindown you can carefully! do the opposite and decrease voltage and frequency. The turbo's inertia will be converted an drive your intermediate voltage rail, which may fry your transistors if you do not dispose the power Incidentially I have worked with a Turbovac 50 as well. I also used its TURBOTRONIK controller and didn't like it that much 20-Apr-20 12:00 PM @analogmultiplizierer are you using back emf to measure the speed of your turbine ? do you have hall effect sensors on it ? 20-Apr-20 12:02 PM Nah, much easier: I don't measure anything 20-Apr-20 12:02 PM I like what you are saying a lot 20-Apr-20 12:08 PM If you increase the frequency too fast, the rotor will not keep up and the slip will increase drastically. Afaik this will only cause the torque to decrease and the phase currents to increase. By measuring the intermediate rail's current such an incident should be easily detectable without any damage to the pump 20-Apr-20 12:09 PM @analogmultiplizierer are you just assuming speed out equals programmed frequency from the controller? Or is that impossible since it's induction? 20-Apr-20 12:10 PM That's my prototype so far. I am planning to draw schematics in kicad and mill a PCB for it 20-Apr-20 12:10 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/turbo-52582.jpg 20-Apr-20 12:11 PM In both induction and synchronous motors, the AC power supplied to the motor's stator creates a magnetic field that rotates in synchronism with the AC oscillations. Whereas a synchronous motor's rotor turns at the same rate as the stator field, an induction motor's rotor rotates at a somewhat slower speed than the stator field. 20-Apr-20 12:11 PM (says Wikipedia) 20-Apr-20 12:11 PM "somewhat" seems a bit too imprecise for me 20-Apr-20 12:11 PM Afaik there is no easy way to measure its rotors speed from its phases 20-Apr-20 12:13 PM @analogmultiplizierer I am planning to leave the rotor in open loop without any power and measure the back emf of the motor to get the speed, it would only take a few ms without any power to the turbine, I hope it works 20-Apr-20 12:13 PM that somewhat is depending on the torque, the difference in the rotor's and stator's speed and the stator current 20-Apr-20 12:13 PM I strongly doubt that there will be any back-emf when you remove power, as the rotor will not stay magnetised 20-Apr-20 12:25 PM That's a good point, I feel like the inductors while discharging will keep the rotor magnetised enough time so I can do my measurement but that needs to be verified 20-Apr-20 12:37 PM To some degree there actually is remanence in the rotor which will induce a voltage in the stator when being turned I doubt that a measurement of rotor speed is necessary for the operation of a turbomolecular pump and i doubt that the commonly used controllers do it. Measuring power consumption i.e. measuring the intermediate rail current is a very easy way to measure the rotor's load I strongly reccomend you to do experimentation with an ordinary induction motor. Electrically thery're identical to turbos of such type 20-Apr-20 12:37 PM It is possible to build a VFD that's universal enough to drive both ordinary induction motors and turbomolecular pumps. 20-Apr-20 12:37 PM Are sine filters a common thing with the controllers that are commonly used for turbos? I have built one that fits my TV 301, but I don't know if it is needed/advantageous 20-Apr-20 12:49 PM How do you proceed to measure the intermediate rail current? 20-Apr-20 12:49 PM I will try to find one, in the meantime I have access to a forevacuum pump powerful enough to run the turbo 20-Apr-20 12:49 PM On the NT10 controller for my pump there are sine filters, I don't know if it is the norm though 20-Apr-20 12:56 PM @analogmultiplizierer both my first turbos report RPMs and are pretty much exactly what the controller setpoint requests 20-Apr-20 01:42 PM On the NT10 controller for my pump there are sine filters, I don't know if it is the norm though @Epilogis thanks! Could you please make a photo of it? I wonder what inductors they chose (Ferrite or Iron) @analogmultiplizierer both my first turbos report RPMs and are pretty much exactly what the controller setpoint requests @nmz787 that still needn't say that the rotor's speed is being measured, it may as well be the speed of the stator field, which is close to the rotor speed during normal operation. On the other hand there may be another motor type used in your turbo or a separate sensor may be reading the RPMs instead How do you proceed to measure the intermediate rail current? @Epilogis Again, it's simple. In my prototype I have a shunt resistor that connects between ground and the low side MOSFet's sources. I think I have included an RC low-pass as well. 20-Apr-20 01:58 PM @analogmultiplizierer Sure; 20-Apr-20 01:58 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/PSX_20200420_225750-E5A0E.jpg 20-Apr-20 01:58 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/PSX_20200420_225810-53359.jpg 20-Apr-20 01:58 PM Thanks for the shunt, simple is often (if not always) the best solution 20-Apr-20 02:15 PM thank you! Looks like ferrite to me. I wonder whether iron could be better as it should reject harmonics by eddy currents, just like ferrite beads, but for smaller frequencies :-D A shunt may not necessarily be the best solution here. Sensing the shunt voltage against ground may be a challenging task. One may prefer to use hall current sensors like the ACS711 as those are a very easy to use and complete solution 20-Apr-20 02:20 PM If it is correct the symbol on the schematic is iron core not ferrite 20-Apr-20 02:20 PM Thanks! I'll look that up tomorrow 22-Apr-20 02:15 PM Does anyone have experience with polyimide photoresist? Like where or how a regular joe could get some... 22-Apr-20 04:16 PM how a regular joe could get some... @piGuy I had once dealt with the german manufacturer Allresist, but did not do so as a regular joe ;-D My experience is that you need to look into catalogues or mail the sales departement to check whether the desired product is offered. I think there is no need to have a company address to get an invoice answered but I am quite sure that those manufacturers are not used to sell to private customers In case of AllResist a quick search resulted in this one: https://www.allresist.de/wp-content/uploads/2015/12/allresist_produktinfos_sxar-pc5000-82-7_deutsch.pdf 22-Apr-20 04:17 PM Thanks @analogmultiplizierer ! I do have an LLC for my home lab so maybe that will be enough to convince a supplier... 22-Apr-20 06:26 PM @piGuy try these folks http://www.tokamerica.com/contact/ 22-Apr-20 06:26 PM They did simulations for free, all comms over email years ago 22-Apr-20 06:26 PM So you could probably get a reasonable response for your product request 24-Apr-20 09:18 PM Anybody know the breakdown temperature of Ethyl Cellulose in vacuum? Pumping some of those sample cathodes I sprayed and getting fluctuating pressure during bake out. Wondering if ethyl cellulose breaks down at lower temps than the nitrocellulose or butyl acetate used as binders in the mixtures I usually use. Bake out base pressure is about mid -5 scale and its periodically coming up to high end of -4 scale then going back down. Temps are at about 250 C at the moment. 24-Apr-20 10:17 PM Update...... I forgot to turn on the baffle and pump cooling.. face palm. 24-Apr-20 10:17 PM Condition normal now. 24-Apr-20 10:17 PM Fortunately this system is relatively back stream and oil pump out resistant. Should be fine. But I will move up the next system reconditioning to sooner than later. 26-Apr-20 12:28 PM Have people done much sputtering here? 26-Apr-20 12:29 PM Yes, but not on purpose ^^ 26-Apr-20 01:18 PM Haha 26-Apr-20 01:18 PM is sputtering the best way to get a strongly bonded copper layer on Ceramics? (Alumina, glass, etc.) 26-Apr-20 01:18 PM sputter + electroplating it thicker / depositing 26-Apr-20 02:19 PM All depends on specific layers 26-Apr-20 02:19 PM Gotta check google scholar 26-Apr-20 02:19 PM Adhesion/bond strength 26-Apr-20 10:41 PM Ugh, sucked white flour into my little welch gem 1.0.... luckily I've already got replacement oil for it, but no seal kit, etc. Owned it for a decade or little more and never replaced or added oil. Guessing the people i got it from hadn't done any service on it either 26-Apr-20 10:51 PM sucked white flour into my little welch gem 1.0. excuse me? 26-Apr-20 11:13 PM Yeah, I use it for household duty pretty much since I got it 26-Apr-20 11:13 PM I've got a foodsaver canning jar attachment like this 26-Apr-20 11:13 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/15879680033991322841667344409746-32B4A.jpg 26-Apr-20 11:13 PM Bottom side 26-Apr-20 11:13 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/15879680960288885757974014472173-1608E.jpg 26-Apr-20 11:13 PM You put the lid in there, then shove the whole thing over the jar 26-Apr-20 11:13 PM If I would have slowly placed the hose on the hole, allowing some ambient air to leak, pumping the jar slower... i might not have exploded the flour into that thing and then into the pump 26-Apr-20 11:13 PM It pretty much just stopped running as soon as I placed the hose onto that jar sealer hole... Ooops 26-Apr-20 11:13 PM I cut the power immediately, then second guessed myself and pulsed the power for a second to see if things would magically be fine 27-Apr-20 08:09 AM Ooooof 27-Apr-20 10:51 AM @nmz787 that's just you being scientific..."hypothesis: flour will get sucked into my pump. experiment: ..." 27-Apr-20 11:39 AM Hahaha 27-Apr-20 01:18 PM Hahahahaha... fortunately pump flushing fluid is cheap. Also I would put the contaminated oil through a simple coffee filter in a strainer and I bet it will be ok. 27-Apr-20 01:55 PM X___x 27-Apr-20 02:10 PM mmm, rotary vane bread maker 27-Apr-20 07:51 PM https://www.youtube.com/watch?v=0qkqQFsNFy0 27-Apr-20 07:51 PM One heck of a vacuum chamber, also one heck of an e-beam welder 27-Apr-20 08:08 PM even just one heck of a warehouse... 27-Apr-20 08:19 PM Leak checking the entire thing must be quite a nightmare, there are hundreds (if not thousands) of water feedthroughs, countless sources of potential virtual leaks and the entire plasma vessel must go down to 10^-11 Torr 27-Apr-20 08:19 PM Actually the residual impurities on parts is probably what matters the most, so cleaning all the hundreds of thousands of little tungsten blocks in the divertor and beryllium on the first wall will be so tedious 27-Apr-20 08:33 PM There are nearly 1000 thermocouples on the vacuum chamber, and apparently over 100 km of electrical cable running around or into it. I would've thought that the RF and electrical noise would make that impractical, but apparently not 27-Apr-20 08:33 PM I think that sector took 8 years to make 28-Apr-20 05:29 AM Joined the server. 28-Apr-20 06:22 AM <𝓕ermion#6024> hey if you wanted to design a standardized board for a standardized chassis, what would you use? 28-Apr-20 06:22 AM <𝓕ermion#6024> do people still design stuff for vmebus? 28-Apr-20 06:22 AM <𝓕ermion#6024> is there something like vmebus that's a bit shorter? 28-Apr-20 06:22 AM <𝓕ermion#6024> I do not wanna speak PCI though... 28-Apr-20 06:22 AM <𝓕ermion#6024> or PCIe 28-Apr-20 06:22 AM <𝓕ermion#6024> ISA would be fine... USB... I just wanna slot into a backplane with USB or serial. 28-Apr-20 06:22 AM <𝓕ermion#6024> CAN is fine too 28-Apr-20 06:31 AM Euroboards? 28-Apr-20 06:31 AM Ah, apparently they're called eurocard 28-Apr-20 06:32 AM <𝓕ermion#6024> does that have a standardized backplane? 28-Apr-20 06:32 AM should have 28-Apr-20 06:32 AM this type 28-Apr-20 06:32 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/fetch-EF148.png 28-Apr-20 02:27 PM Joined the server. 28-Apr-20 03:01 PM I think #introductions_and_directory is meant for just that. But yeah I emailed @BestFleet when someone posted the turbopump Reddit post. 28-Apr-20 03:01 PM How did that come up? Did someone just suggest it as a hard to make expensive product and you wanted to try it DIY? 28-Apr-20 03:07 PM Frankly, yeah. Always thought trying to machine some kind of turbine rotor or similar sort of thing. I first heard of them from the AppliedScience youtube channel and decided to go for it. I was about 20 minutes too late to pull two Turbo-V 250 pumps from a mass-spectrometer that I found in the garbage at MIT (because they literally just throw stuff like that out 28-Apr-20 03:07 PM At this point I've run it up to 10k RPM in atmosphere using air, but I need a bigger power supply to get the motor running and then I'll try pulling a vacuum and running it faster. 28-Apr-20 03:12 PM If they were thrown out they usually are either broken or missing the (broken) controller. The latter is much easier to remedy... 28-Apr-20 03:13 PM The whole mass-spec was thrown out. It was one of those whole workstation models. The guys who tore the thing apart to get the turbos (and controllers) seemed to think they were still good. 28-Apr-20 03:13 PM Lucky them then! 28-Apr-20 03:14 PM I was able to get the detector though, a Microchannel plate detector and a photomultiplier. 28-Apr-20 03:15 PM Both?... as in the mcp has a phosphor screen to see with the pmt? 28-Apr-20 03:15 PM Yeah so it had a mcp held in front of a phosphor and then a lens and then the pmt. Not certain why 28-Apr-20 03:16 PM What size of mcp? ~40mm? 28-Apr-20 03:16 PM This could have been a COLTRIMS or similar setup. For velocity map imaging rather than just time of flight 28-Apr-20 03:19 PM The portion of the mcp I can see is 45mm diameter. I assume there 28-Apr-20 03:19 PM is some more under the housing. Maybe 50mm total? 28-Apr-20 03:19 PM Here’s how it was set up. 28-Apr-20 03:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-E1BCF.jpg 28-Apr-20 03:20 PM Cool! We have two of those form Tectra, they're about $10,000 each 28-Apr-20 03:20 PM I hope by was you mean still is? or did you disassemble the stack? 28-Apr-20 03:20 PM The viewport there looks a lot smaller than the MCP? 28-Apr-20 03:23 PM Ah well was means was, in this case. I'd never heard of a mcp until after I took that one off and brought it to a friend who was able to identify what it was. The phosphor and lens are still there though. 28-Apr-20 03:23 PM The viewport at the end, for the PMT? I assume it can be small because of the lens that's on the back of the phosphor. 28-Apr-20 03:24 PM It was probably burnt out? or the group that ditched it literally bleeds money 28-Apr-20 03:24 PM for VMI you replace the PMT with a camera. 28-Apr-20 03:25 PM it being dead would be a good explanation for a whole mass spec system getting tossed out 28-Apr-20 03:25 PM Yeah I'm trying to not get my hopes up too much. I do hope the PMT is good, but the mcp is just a bonus if I can make it work. 28-Apr-20 03:27 PM and if the MCP turns out to be totally dead, looks like you've got some nice feedthroughs to play with in its stead 28-Apr-20 03:27 PM do you have a photo of the viewport for the PMT? 28-Apr-20 03:27 PM kinda curious what that looks like 28-Apr-20 03:27 PM .. oh, that thing is the viewport assembly 28-Apr-20 03:31 PM Kinda hard to photograph but I’ll send a picture. 28-Apr-20 03:31 PM right? weird 28-Apr-20 03:31 PM ok 28-Apr-20 03:31 PM has no idea what they're looking at 28-Apr-20 03:31 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-203D0.jpg 28-Apr-20 03:31 PM oh, so the PMT couples to that little hole in the center? 28-Apr-20 03:32 PM Guessing a tiny quartz window, 20mm. That is from the outside, so the Pmt just pushes against that o ring. 28-Apr-20 03:33 PM ahh ok 28-Apr-20 03:34 PM Ok so not for VMI 28-Apr-20 03:34 PM I've never seen a system like that. We use a PMT + phosphor screen for our ToF, but only because then we can switch between VMI and ToF without adjusting anything. If you don't have a window big enough to see the whole phosphor screen, you normally filter out the DC and read the MCP voltage directly without any phosphor screen... 28-Apr-20 03:34 PM PMTs break pretty easily by the way 28-Apr-20 03:39 PM I have the mcp and the pmt packaged as carefully as I could to try to protect them, especially since it'll probably be at least a year until I use either one of them. 28-Apr-20 03:39 PM I believe the mass-spec system was from a bio lab, so it might be something specilized for working with biological samples? Again, I know very very little about this stuff. 28-Apr-20 03:40 PM break how? @idmb 28-Apr-20 03:40 PM MCPs normally gets stored in high vacuum - when they ship them they come with a sealed off flange 28-Apr-20 03:40 PM if you shine a flashlight at a PMT while it is biased it will lose sensitivty - so I've been told. 28-Apr-20 03:41 PM oh, yeah, the photocurrent will go to some astronomical level and cook it 28-Apr-20 03:41 PM I think the specs for one of our older ones say to keep the readout voltage below ~1V, and that as long as the combination of input light + bias current does that, it should be fine 28-Apr-20 03:42 PM they need to be absolutely light-tight and you'll see it in your readings if it's not 28-Apr-20 03:42 PM Eh... everyone I know just drapes a black cloth over them 28-Apr-20 03:42 PM and electrical tape 28-Apr-20 03:43 PM yeah electrical tape works pretty well with 1.5-2 layers of the stuff 28-Apr-20 03:43 PM at least for radiation-detection scintillators 28-Apr-20 03:44 PM I mostly use a PMT for readout speed + a bit of sensitivity, though. Signal strength isn't my problem. So that's why we get by without proper stray light blockage. 28-Apr-20 03:44 PM if you're able to do so, wrapping the whole thing in electrical tape and hooking it up to get a dark current read can be informative. dark current'll be high for 24-48h after having been exposed to ambient light tho 28-Apr-20 03:44 PM ah 28-Apr-20 03:44 PM but yeah.. i picked up a secondhand ebay MCP a while back to dork around with (moooostly for the feedthroughs >.>) and it's going to need a lot of pumping and careful conditioning before i put voltage on it. it may just cook itself instantly anyways 28-Apr-20 03:44 PM not sure if a spent-too-much-time-in-atmosphere MCP is ever salvageable 28-Apr-20 03:44 PM i think? if you keep stray light to an absolute minimum and aren't screaming into it during operation, the usual deciding factor in PMT lifetime is a function of ambient helium diffusion through the glass 28-Apr-20 03:44 PM there're certainly other failure modes too, but that seems to put a 10 year lifespan on the things, ostensibly before parameters drift too much out of spec 28-Apr-20 03:44 PM . o O (my 50yr old PMTs are still kickin, but maybe they're noisier than they oughta be.. shrug) 28-Apr-20 04:19 PM not sure if a spent-too-much-time-in-atmosphere MCP is ever salvageable Have used one that sat on a shelf with just tin foil over it for 1-3 (?) years, worked fine. Had some "dead" spots which were less sensitive than others, but that matters soooo much more for 2D imaging than just ToF 29-Apr-20 11:19 AM yeah, mine's meant for 2D imaging afaict (resistive anode encoder) so i should get all the dead spots nice and visible on my 'scope :D 29-Apr-20 12:04 PM this might be better answered with five minutes of molflow simulation, but: anyone know if there's any significant difference in pumping speed between a mitered vs. curved 90 degree elbow in UHV conditions? 29-Apr-20 12:04 PM definitely not significant. 29-Apr-20 12:04 PM curved should be better, but it should not be significant. 29-Apr-20 12:04 PM page 74 here states it's equal https://www3.nd.edu/~nsl/Lectures/urls/LEYBOLD_FUNDAMENTALS.pdf 29-Apr-20 12:04 PM 73 in the real document, 74 of pdf 29-Apr-20 12:10 PM hmm ok 29-Apr-20 12:10 PM that saves me about $20 and lets me go with the more aesthetically appealing choice then 29-Apr-20 12:10 PM ty 29-Apr-20 12:11 PM curved CF is "the norm" 30-Apr-20 10:01 PM <𝓕ermion#6024> hey are people building new NIM cabinets and devices? 30-Apr-20 10:01 PM <𝓕ermion#6024> also... let's suppose I want to make my own custom NIM module 30-Apr-20 10:01 PM <𝓕ermion#6024> where do I start? 30-Apr-20 10:01 PM <𝓕ermion#6024> are there good solidworks or fusion360 models to start with? 30-Apr-20 10:01 PM <𝓕ermion#6024> are there off the shelf parts for the rails and plates that can be machined? 30-Apr-20 10:23 PM My guess is, buy an old NIM module and measure with a tape or ruler... Or find a datasheet with CAD drawings 01-May-20 02:10 AM people here are trying to build their own NIMs, but man that stuff is expensive 01-May-20 02:10 AM the connector alone is like 50 bucks on mouser 01-May-20 02:10 AM it would be way cheaper to get some old module and replace the front panel and internals 01-May-20 07:25 AM <𝓕ermion#6024> I mean what about in a research group? 01-May-20 07:25 AM <𝓕ermion#6024> I'm putting 500 bucks worth of stuff in there I don't care about 50 dollerydoos for a connector 01-May-20 08:20 AM We just have old NIM chassis in storage 01-May-20 08:20 AM I’m using one in a rack as a shelf 01-May-20 02:04 PM https://inis.iaea.org/collection/NCLCollectionStore/_Public/21/080/21080298.pdf here is, i think, the latest NIM specification 01-May-20 02:04 PM buying crusty old modules on fleabay to shred to bits is almost certainly gonna be your cheapest option for getting empty module shells + connectors 01-May-20 02:04 PM new NIM modules and bins are definitely still made, though it seems to be relegated largely to smaller-scale experimentalist stuff or module units that predominantly have hefty power requirements/comparatively minimal I/O requirements 01-May-20 02:07 PM new NIMs are still being produced, but they're hella expensive 01-May-20 02:08 PM but for getting started you can literally just drill some mounting holes in a bit of perfboard that match whatever your old module uses, or drill+tap some new ones entirely. it seems like the spec is only followed for the voltages, signaling, and external module geometry; everything that happens under the covers is a free-for-all 01-May-20 02:08 PM i feel like anything 'new' in this space is gonna be wicked pricey 01-May-20 02:12 PM I once asked a local company here for a bias supply, 0-5 kV, a watt or so output capability, single channel starts at 1.2 k€ iirc 01-May-20 02:12 PM I wonder if there's any expensive testing included to call something "spectroscopy grade" 01-May-20 02:16 PM curious what that means in terms of specifications 01-May-20 02:50 PM In fairness the bias supplies used for spectrometers can be reallllllly stable 01-May-20 02:51 PM they sure are 01-May-20 02:51 PM but afaik they're still some of the simpler parts in a spectroscopy setup 01-May-20 05:02 PM Ion ToF is all simple and cheap. 01-May-20 05:03 PM I wasn't talking about the detectors, but only the NIMs 01-May-20 05:03 PM for TOF you still need a (very stable) TAC etc, right? 01-May-20 06:08 PM TAC? 01-May-20 06:29 PM All I can say is the ToF I built last year is very simple and works fine with 40 year old 3kV PSUs from storage, but that the MCP assembly is quite expensive and machining macor was quite pricey 01-May-20 06:29 PM It’s for determining ion fragmentation patterns for molecules 02-May-20 05:28 AM time to amplitude converter, so you can feed the time (of flight) to an mca 02-May-20 09:39 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_9354-64375.JPG 02-May-20 09:39 AM i got these new viton rubber inserts (left) for the ballast pipes -- they should be the same as the right ones...am i really supposed to stretch them that much around the pipes or was i sent the wrong part? 02-May-20 09:39 AM the right ones are what i took out of the pump 02-May-20 09:54 AM that looks like the wrong part...which is very frustrating 02-May-20 10:05 AM ahh yes, alrighty 02-May-20 10:18 AM what are people using for cleaning PCBs these days? needed to grab some more 99% IPA when the whole panic buying thing kicked off and it seems like things have not really restocked yet. 02-May-20 10:27 AM distilled water will work fine 02-May-20 10:42 AM @GigaSquirrel congrats you used another acronynm I don't know to clarify an acronym lol 02-May-20 10:42 AM system is three simple electodes, one grounded and the others at 5-20kV and 0.7x 5-20kV fto form a "velocity map imaging time of flight spectrometer," then there's a few tens of cm, then a Microchannel Plate and can either use a high voltage highpass filter (simple to make) to read off the MCP directly on a scope or have one with a phosphor screen and use a photomultiplier 02-May-20 11:22 AM Joined the server. 02-May-20 11:48 AM https://electronics.stackexchange.com/q/317859 02-May-20 11:48 AM Keeping in mind 02-May-20 11:48 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/solvent.miscibility_1-43BC5.pdf 02-May-20 12:21 PM @idmb I assume MCA is multi channel analyzer... Which afaik is just another name for an ADC with memory and later ability to bin readings 02-May-20 01:24 PM We just use a pretty low range oscilloscope 02-May-20 01:42 PM For most TOF applications, an oscilloscope will do 02-May-20 01:42 PM But if you have so many data points that it takes days to collect your data, then something like this would be more appropriate 02-May-20 01:42 PM https://www.fastcomtec.com/fwww/datashee/photon/mcs6.pdf 02-May-20 01:42 PM Or if you need a lot of channels and don't have an insane budget, something like this: 02-May-20 01:42 PM https://www.cronologic.de/time_measurement/tdc/hptdc/HPTDC_description.pdf 02-May-20 01:42 PM They also make dedicated TOF ICs for radar and lidar applications, they are more than precise enough to resolve down to a few picoseconds 02-May-20 01:42 PM But not stable enough to accumulate data for days 02-May-20 06:16 PM So null issue or bad idea: routing a 40amp 240VAC circuit in the ceiling above my FIB? 02-May-20 06:47 PM don't put wiring in your plenum airspace 02-May-20 06:47 PM there's a whole Fire Code thing about that 02-May-20 10:05 PM It's a garage crawl space, it's already got wiring 02-May-20 10:05 PM My concern was inducing 60Hz mostly 02-May-20 10:26 PM @qualia it appears that a plenum is only present when there's pressurized air involved, which in my garage there is not 02-May-20 10:29 PM oic 02-May-20 10:29 PM but for EMI reasons i'd probably also avoid that unless you could run it in grounded conduit or somesuch 02-May-20 10:55 PM Hmm, that might not be a terrible idea, but it's getting into territory that I'm not sure i want to venture into 02-May-20 10:55 PM The feed was going to be for my shed and thinking I'd place my welder out there... Which wants its own ground for emi reasons 02-May-20 10:55 PM So if I did that overhead bit, I'd guess I'd want to ground the conduit at the same point as the breaker panel, and then keep that disconnected from the shed's ground via some insulated in-ground conduit (it was destined to be buried) 02-May-20 10:55 PM Hrmmm 02-May-20 10:55 PM At the same time, i really want to just expand my garage but have been dragging my feet on getting CAD worked up for the idea, which is needed for permits 03-May-20 09:53 AM arg, disassembled trivac completely, removed all the awful thick rust/oil inside, derusted, cleaned, reassembled, still can't get below ~50torr...i did explode the diaphragm valve which i think was held together with adhesive but put it back together, not sure if that's the issue 03-May-20 11:17 AM @samy bah, I thought you got a rebuild kit 03-May-20 11:18 AM i replaced one of the gaskets i broke taking it apart, none of the rebuild kits have that diaphragm part. i also am using a TPU gasket instead of a real one as a company sent me the wrong gasket so that could be an issue, but i'll find out when i take it apart again 03-May-20 11:24 AM at minimum wage I believe you've hit the "just buy another used one" mark lol. learning much? 03-May-20 12:06 PM haha that wouldn't be fun 03-May-20 12:06 PM learning a bit, was interesting to make some molds/casts and see how it works inside 04-May-20 11:00 AM @LRM I think you can get away with less than 99% IPA for cleaning PCBs if that makes it easier to source. I think I use something like 91% IPA from the store, in an ultrasonic cleaner followed up by compressed air to dry. 04-May-20 11:11 AM Yep, I used up the last of my 91% a week or so ago and have not seen any in stores anywhere for...awhile. Thanks for the suggestion though 04-May-20 02:21 PM @LRM ethanol should work too, liquor stores... 04-May-20 08:47 PM Is this just for general cleaning or are you actually de fluxing boards with RA flux? 04-May-20 09:10 PM I usually use it just for a cosmetic clean up on boards using a cotton swab to get any majorly noticeable areas of flux 06-May-20 03:36 PM I find RD-30 rotary vane vacuum pump VacuuBrand pump . It’s 30m^3/h , 2e-4 torr , 3phase , more 30 years old not sure working but the price is around 100$ . Any ideas , is this pump valve to buy it or not ?? 06-May-20 03:36 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-D3107.jpg 06-May-20 03:36 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image1-33A93.jpg 06-May-20 03:36 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image2-40414.jpg 06-May-20 03:36 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image3-3C688.jpg 06-May-20 03:36 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image4-11EB7.jpg 06-May-20 03:36 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image5-76F85.jpg 06-May-20 03:37 PM euch, not worth $100 06-May-20 03:37 PM unless you're in the middle of nowhere and there's no other likely options, I guess. 06-May-20 03:41 PM unfortunately yes but I find some Alcatel 2633 Pump about 1500$ and don’t have much kind of money. But you think not better to buy it ? 06-May-20 03:46 PM looks pretty grimy.. getting a 3phase controller to run it will probably cost more than the pump itself 06-May-20 03:46 PM if it turns out you have to do major maintenance on that pump you may have a very difficult time finding parts for it 06-May-20 03:46 PM dunno where you are or what you're planning to do with this pump but in the US you can find brand new HVAC-rated dual-stage rotary vane pumps at Harbor Freight for about $150 06-May-20 03:51 PM Iam not live in US . I have 3phase Power and knowledge about 3 phase electro motor repairing . the useful things I find it is this model 06-May-20 03:52 PM 3 phase rotary vane oil pumps in good working condition are still something we're throwing out at universities 06-May-20 03:55 PM Me too will do it that . but you know I live in not free market country like you are but I respect to your advice and stop buy it until I find some better options but I will happy for discussing. 06-May-20 04:09 PM Well all I can say is it's not worth $100 here. You'd probably have to pay someone to take it away 06-May-20 04:10 PM Okay sir no pain and no gain 06-May-20 04:12 PM Samy has been repairing one recently, might have some insight 06-May-20 05:03 PM wish i could help! i empathize in not having a lot of options available, so ultimately you have to gauge whether the additional investment of your time/energy/resources and other requirements for the pump are worth it. i'm sure like many others here, sometimes just fixing something up can be a really enjoyable process itself, but i don't know what other expenses may be required from that and if you have access to the tools needed to repair certain parts 06-May-20 05:03 PM do you know what pressure you're trying to get to? it might be less effort to get something like a compressor from a thrown out fridge/freezer and build your own vacuum pump with it 06-May-20 05:34 PM Thanks dear Samy for your kindness. I am goin to vacuum around 10e-3 torr it need some rotary vane pump 2 stage and idea of make some home made vacuum pump with freezer compressor is really great and amazing but I don’t know how much are ultimate vacuum ? And i Don’t see any label about on compressor . But I will check it . It’s really great dear Samy . 06-May-20 06:05 PM well probably won't get to that pressure with fridge compressor 06-May-20 07:17 PM Yes it’s i just now i check it the vacuum is not so much high . By the way it’s really great. 06-May-20 09:11 PM So its ok to turn off turbo before rough pump right? 06-May-20 09:58 PM We always do, and unless I'm missing something I'm pretty sure that's what you want to do. Turbos aren't happy if their foreline isn't at a good vacuum 06-May-20 09:58 PM And I was missing something, you don't want them to spin down at high vacuum because it takes hours to actually spin down, but we still always turn the turbo off first and it seems to work fine 06-May-20 09:58 PM And Agilent recommends keeping the backing pump on 06-May-20 10:49 PM i keep the backing pump on and open until the turbo hits about 50% speed at which point i valve it off 06-May-20 10:49 PM this keeps backstreaming to a minimum bc that's approximately the point at which my chamber pressure starts rising w/my turbo. the manual suggests similar 06-May-20 10:49 PM (technically around 40% it starts rising, so, headroom) 06-May-20 10:49 PM definitely don't let the foreline go to atmosphere while it's still spinning 06-May-20 10:54 PM Here's the maximum tolerable venting pressure rise curve for my Leybold T1600 06-May-20 10:54 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-A42A5.png 06-May-20 10:54 PM It's definitely necessary to vent it very slowly, just so it doesn't go through the resonances and vibrations as it spin down very very slowly 06-May-20 10:54 PM Whenever I switch off the turbo, I can vent the chamber to atmospheric pressure, so I do the following: 1. Switch off power to turbo 2. Valve off the turbo from roughing pump 3. Turn off roughing pump 4. On the high vacuum side, open up a leak valve which goes to atmosphere/some clean dry gas 5. Vent the roughing pump via one of those KF vent valve 06-May-20 10:54 PM https://www.ebay.com/itm/US-KF-Flange-Stainless-Steel-Vacuum-Vent-Valve-Or-Relief-Valve-For-Vaccum-System/223802783539 06-May-20 10:54 PM Incidentally, I do not recommend venting via these directly to the chamber when a turbo is still spinning, pretty much no control whatsoever and very dangerous 06-May-20 11:38 PM Well my FIB is so integrated, and doesn't even cover turning off the wholr system except for "press the emergency button in case of smoke or bad sounds" 06-May-20 11:38 PM So I ended up: placing ion pump in "HV on (lock)", placing it in "local" control mode, shutting off nitrogen cylinder, shutting off computer, then switching off the vacuum control unit. I'm assuming this causes a foreline isolation valve to close. The rough pump immediately turned off (I think, there were still a bunch of fans going so I'm not sure actually) and also placed the turbo into braking mode. The load lock turbo is still spinning down on what seems like inertia. Then I turned off all other sub system control power switches, including the main turbo controller. 06-May-20 11:38 PM But for systems I'm building, I'll keep in mind to turn off turbo first, and maybe close an isolation valve simultaneously if I also want to turn off the rough pump 06-May-20 11:44 PM I have the isolation valve because I don't want to rely on the anti-suck back valve on the roughing pump and prevent oil back streaming into the chamber. It's not completely necessary for venting 06-May-20 11:44 PM Hooked up my FIB to my home network 2 weeks back and enabled remote desktop... So added an account password for security... Haven't touched this since then and ooops forgot the password. Luckily its windows XP and I have a NT password changer CD from like 15 years ago 06-May-20 11:45 PM Ah wish I could do that to the enormous console for my SEM from the 80s 06-May-20 11:45 PM But yeah, no obvious controls available even in "service" mode in the software to control the isolation valve and turbos and rough pump :/ 06-May-20 11:45 PM Unfortunately there's no easy way to focus and stigmate from the GUI... so I actually do need to reverse engineer some stuff further, or build a little box with ethernet to interpose the physical focus knob panel, to get full remote control 06-May-20 11:48 PM Why do you want remote access? Just for convenience sake or is your FIB super loud? 06-May-20 11:50 PM Mostly because I want to automate some stuff like movie making and workaround issues with their crappy etching interface 06-May-20 11:50 PM Do things like take an image, mark areas to selectively etch based on contrast or edge detection, then use reduced scan imaging on those areas to etch 06-May-20 11:50 PM Their software allows BMP input for etching too, but it seems to give an access exception (i.e. memory issue) 9 times out of 10 06-May-20 11:50 PM I guess that /could/ be actual bad RAM, which is something I need to check with memtest86 or something 06-May-20 11:50 PM Either that or the memory on the scan board, or their software just plain sucks 06-May-20 11:50 PM (it was engineered for a failure analysis workflow) 06-May-20 11:50 PM Cutting rectangles or rectangular trenches works pretty well, fails with exception maybe 1 out of 10 times... And that's because of stupid GUI bugs where you drag the selection box outside of the image area, and it's so stupid instead of stopping at the bounds, it gives an error that you tried to go out of bounds 06-May-20 11:50 PM This bug is also present if you're simply trying to draw a reduced frame imaging area box too... So it's just bad GUI validation/testing 07-May-20 07:19 AM We do the “turn the turbos off then wait an hour for them to spin down” thing. Happens faster if you close a valve behind them 07-May-20 07:20 AM They make (comparatively) horrible noises, at least mine does 07-May-20 07:20 AM I think the magnetic bearing might not be designed to hold the rotor away from the safety/touchdown bearings, and you can hear that 07-May-20 07:20 AM Only happens during spin down for some reason 07-May-20 07:22 AM Only bad noise any of ours makes is the leybold 1000C on spinup. Sounds like a jet engine. 07-May-20 08:06 AM mine is completely silent at all times. spin-down can take a while, but there isn't usually any rush. 07-May-20 09:07 AM My diffusion pumps don’t make any sound! Hahahaha... I do realize they are not suitable for many applications. 07-May-20 09:26 AM My levitation bearing holds the rotor up, but it makes a nasty sounds when you turn off the controller finally 07-May-20 09:26 AM I like the jet engine sounds personally 07-May-20 10:08 AM We have a few forevacuum pumps, the is loudest except when a scroll has worn away a bunch of the tip seal. We have a nearly silent hermetic IDP scroll pump that I love. The iGX600L dry screw makes a very distinct and kinda loud humming noise 07-May-20 10:22 AM A freshly rebuild belt driven Welch 1402 that is properly broken in actually makes a very soothing sound that’s pleasant to work around. A worn out one with leaks and Squeaks is a pain in the butt. 07-May-20 10:51 AM We use diffusion pumps more than turbos tbh charles. Definitely recommend if it's viable for your application. 07-May-20 10:51 AM We also use a lot of , so it's quite loud so I don't generally notice any potential bad noises unless it's really, really bad 07-May-20 02:23 PM What is the red and black icon? Looks like a Lincoln welder 07-May-20 02:23 PM it's an edwards 40 07-May-20 02:23 PM (mouseover displays the emoji name) 07-May-20 02:24 PM I have no mouse on Android 07-May-20 06:52 PM Hmm diffusion pump performance is better than I had realized. Potentially superior chemical process compatibility and better ruggedness against damage in general. The oil gets costly though. 07-May-20 06:52 PM Wonder whether anyone has ever made a Sprengel pump out of galinstan against gallium oxide coated tubing 07-May-20 06:52 PM The vapor pressure of galinstan is extremely low 07-May-20 06:52 PM Incompatible with aluminum though 07-May-20 07:00 PM Does the oil cost even remotely compare to the power consumption in industrial use? 07-May-20 07:01 PM Power isn't that expensive. I see this fallacy often in the server market as well. 07-May-20 07:01 PM I guess diffusion pumps use far more of it though.... 07-May-20 07:01 PM That's a valid point here. 07-May-20 07:01 PM 1kW @ 0.10/kWh = $876 24/365 07-May-20 07:01 PM And oil is cheaper than 2x2 node servers 07-May-20 07:01 PM More of an issue for intermittent users though 07-May-20 07:01 PM Isn't that about the typical lifespan of the oil before it needs to be repurified though? Granted it probably depends fairly heavily on the processes in use. 07-May-20 07:06 PM Also have to consider the need for a cooling system 07-May-20 07:06 PM Turbopumps require just a simple fan or a really low-cost and compact water loop, while you need to make sure the inlet water temperature for diffusion pumps is sufficiently low when rejecting like 10 times the amount of heat 07-May-20 07:08 PM That's true, yes, but mostly just a matter of local clutter and space requirements. 07-May-20 07:08 PM For clean processes, I just opt for turbos every time 07-May-20 07:08 PM A car radiator can dissipate something like 35kW 07-May-20 07:08 PM Yes I did, personally 07-May-20 07:09 PM Chilling the water might be necessary 07-May-20 07:09 PM Oh what are typical inlet temp needs? 07-May-20 07:09 PM 16-27C apparently 07-May-20 07:09 PM Yeah, below 25C ideally 07-May-20 07:10 PM I see, yes that would often need chilling or a very oversized radiator 07-May-20 07:12 PM I'm building such a cooling system right now, for a laser not for a diffusion pump. I oversized the radiator, and have a bunch of free peltiers to hopefully achieve inlet temp ~20C with 1kW heat rejected 07-May-20 07:12 PM There's also the issue of fixing leaks, and plumbing can quickly add up in cost. 07-May-20 07:14 PM Interesting-- nice sized laser. What kind? I have a chiller that was from a laser, that I upgraded to go sub-0C, but the actual power is pretty low 07-May-20 07:15 PM Q-switched DPSS Nd:YAG, 50W average power output from the laser, about 850W power to the pumping diodes 07-May-20 07:15 PM It requires quite high coolant pressure too 07-May-20 07:16 PM Microchannels I imagine 07-May-20 07:16 PM Manufacturers seemed to initially be rather fascinated with them, but pulled back on customer annoyance 07-May-20 07:17 PM Yeah, 1.8 bar drop across both the q-switch and the DPSS module 07-May-20 07:17 PM So pump is pretty costly too, not to mention the noise 07-May-20 07:17 PM Ah so it needs a water filter sort of pump then 07-May-20 07:18 PM https://www.amazon.com/gp/product/B01MUXMF40 07-May-20 07:18 PM I have a 4 bar one I bought to drive an RO-DI filter chain fairly cheaply, but it is indeed somewhat loud and its life expectancy remains uncertain 07-May-20 07:18 PM Yes very similar design actually 07-May-20 07:19 PM They are surprisingly loud... Especially when working under full pressure 07-May-20 07:19 PM Designed for outdoor use 07-May-20 07:19 PM Meanwhile, I can't even hear some of my turbos over the roughing pump when they are running 07-May-20 07:21 PM Yes I can't either. The vibration is barely noticeable on contact either. But the gyroscopic precession is disturbingly strong. Not that moving a running turbo is a good idea. I try not to do that anymore. 07-May-20 07:21 PM My SD-200 backing pump is surprisingly quiet once it pumps down also. Whereas my random Chinese single stage pump never stops being about as loud as my oilfree air compressor. 07-May-20 07:24 PM Hmm, I'm looking for a good quiet air compressor 07-May-20 07:24 PM California Air Tools 07-May-20 07:24 PM I've heard good things about california air 07-May-20 07:24 PM Yeah 07-May-20 07:24 PM Yes 07-May-20 07:24 PM Get the quietest kind. I still regret getting only the second quietest one, and it's already pretty good 07-May-20 07:24 PM 58dB or something 07-May-20 07:24 PM The top tier one is closer to 50 iirc 07-May-20 07:24 PM Whereas that Chinese 300 bar... thing... is 78dB 07-May-20 07:24 PM To its credit, though, it does work. And so do all the stainless steel 8mm quick connect paintball fittings and hard lines and coupling hoses and such. It's kind of impressive that running at 4500psi isn't fundamentally more difficult than running at 120psi. 07-May-20 07:29 PM I've got a California air tools compressor 07-May-20 07:29 PM Oil free 07-May-20 07:29 PM Was looking earlier at this chiller, thinking of my welder and my sem's diff pump 07-May-20 07:29 PM https://www.amazon.com/BestEquip-Industrial-CW5000DG-Capacity-Thermolysis/dp/B075F2JY97/ 07-May-20 07:30 PM Do TIG welders really need chillers? I've always been fine with just a bucket and a radiator >___> 07-May-20 07:30 PM But I do see them mentioned often 07-May-20 07:36 PM I would've opt for something like that myself if not for the cost and the lack of pressure 07-May-20 07:36 PM I also have a diffusion pump right now that I don't have any use for 07-May-20 07:36 PM It has a metric ASA style flange on it, might not be standard actually 07-May-20 07:36 PM But it does come with a cooled baffle 07-May-20 07:36 PM That's the other thing, when you get a cheap diffusion pump off eBay, you're likely not going to get the matching baffles as well, so you might coat your entire chamber in expensive oil 08-May-20 12:17 AM @niflheim I don't think so, but I think for the SEM it would be needed for the summertime 08-May-20 05:37 AM Incidentally I finally found a cheap TIG torch capable of using the giant 1/4" thoriated tungsten electrodes I found a while ago-- the WP-12. I bought them mainly for making high temperature structural components like the main power feeds into the argon furnace I am building, but they could also perhaps be interesting for DCEP. 08-May-20 12:49 PM Ah, interesting 08-May-20 01:07 PM I have used an air cooled TIG torch. If you have a beefy welder, then the torch becomes the limit on amps and duty cycle. 08-May-20 01:07 PM The makerspace bought a $5k Miller TIG with water cooling. That thing can pump a lot of power. 08-May-20 01:07 PM 280 amps. The TIG I first learned on was limited by the torch to 100 or 150 amps. 09-May-20 03:55 PM The torch I was sold is air cooled and they said it's limited to 200 amps... I've heard watercooled are smaller thus easier to work with in cramped conditions 09-May-20 10:23 PM IGP was at 38uA when the turbo was on, next day it was 1.4mA and today it was at 2.4mA 09-May-20 10:23 PM (everything but IGP is off for 2 days now) 09-May-20 10:48 PM will a rotary vane pump behave any differently if the oil is near the 'min' line vs middle vs 'max'? 10-May-20 02:05 AM Nope, not at all 10-May-20 02:05 AM well the closer it is to "min" the faster it will run out of oil, but that's about it 10-May-20 02:05 AM I've been wondering, do car shops do turbo balancing? 10-May-20 02:05 AM Maybe I can ask them to balance a tmp 10-May-20 02:56 AM I doubt a regular car shop would have a turbocharger balancing machine 10-May-20 02:56 AM You'd have to go to a pretty specialized place to do it, and because this is a special task they're likely not experienced in, you might have to pay a lot 10-May-20 02:56 AM And forget about crankshaft balancing machines 10-May-20 02:56 AM Material removed from rotors are one to two orders of magnitudes smaller than on crankshafts, and turbopump rotors spin an order of magnitude faster 10-May-20 02:56 AM They also don't have a convenient counterweight for material to be removed by drilling or milling 10-May-20 02:56 AM I've had to get a company to balance 3 crankshafts for a motorcycle engine, the stated tolerance on material removal was something like 1 g by drilling holes 10-May-20 03:00 AM ah well 10-May-20 09:59 AM I thought the turbos had set screws for balancing. 10-May-20 10:00 AM they do 10-May-20 10:37 AM I was of the impression that If you look at a turbo wrong, it will get out of balance.... So I’m very interested in seeing what’s going to happen with that pump of yours with the chopped off blades. 10-May-20 10:39 AM same tbh 10-May-20 10:39 AM :D 10-May-20 10:56 AM Do the maglevs care that much? 10-May-20 10:56 AM Like the same imbalance that would barely ruin bearings wouldn’t be causing a hysteresis smash on a maglev I don’t think 11-May-20 07:29 PM Guy I part time work for told me today that he recoated his scintillator with new zinc sulfide using "mop and glow" 11-May-20 07:47 PM cleans, shines, and protects. 11-May-20 07:47 PM perfect for hardwood, vinyl, and inorganic crystalline scintillators 11-May-20 09:04 PM wat 11-May-20 09:04 PM does mop & glo even have zinc sulfide in it 11-May-20 09:04 PM I call shenanigans 11-May-20 09:04 PM I could almost see it as, like, an optical cement? or a sealant? but .. ?_? 12-May-20 08:21 AM No he had zinc sulfide powder 12-May-20 08:21 AM Just used the mop and glow as a binder 14-May-20 07:06 PM What works works 17-May-20 03:31 AM https://www.youtube.com/watch?v=16vOoF_XUB8 Pretty neat demonstration of hydrogen diffusion 17-May-20 10:18 AM pretty cool 17-May-20 10:20 AM Glasslinger is an interesting guy, I've chatted with him via email a few times 17-May-20 10:21 AM that little probe in his hand is releasing helium, right? 17-May-20 10:23 AM think so 17-May-20 10:23 AM he uses the stuff that comes in the small pink low pressure cylinders for balloons to do his leak testing heh 17-May-20 10:23 AM lot of times people toss em out when there is a good amount left in them i guess 17-May-20 11:30 AM Those cylinders also contain air fwiw. The company tries to provide only enough helium to barely float balloons from my reading. I haven't tested one myself, but would recommend sticking to welding shops and industrial gas suppliers for helium refilling needs. 17-May-20 12:03 PM for a leak testing probe i do not think that the air mixed in really matters? would not use it for anything else. 17-May-20 12:52 PM Yes, my point was that they may not work as well for other uses-- that's all 17-May-20 01:18 PM Ahh wasn't sure if that was the intended meaning or not. For leak testing getting a couple cylinders for free would be pretty handy even if they are nearly empty...but that is about it. 17-May-20 01:57 PM Mr Ron Soyland. I like his videos but the few times I have emailed back and forward with him about giving him some materials to help him out he seems to have no interest. I think he is the type that likes doing something, then that’s that. On to the next thing. 17-May-20 03:05 PM Very much the impression I have gotten. He also has tons and tons of materials already from what he said to me 17-May-20 04:29 PM Here is a perfect example where Ron does not know as much as he things he does. The hydrogen has two sources. First is the hydrogen left in the metals from the hydrogen firing prior to assembly. There is not enough RF bombarding time I’m automatically exhausted tunes to drive it all away. Secondly is the residual water is disassociated to hydrogen and the oxygen is adsorbed by the barium in the getter and the cathode when it’s cold. 17-May-20 04:29 PM Wow. My phone has it out for me with the word replacement stuff. I turn it off, then apples does an update and turns it on again. And it’s so freaking hard to edit on a phone cause they broke the cursor placement scheme. 17-May-20 08:00 PM Oh... I’m sorry. His name is Roy. Hahahaha 17-May-20 08:00 PM Or was it Ron. Ok everybody ignore me. I’m having cognitive difficulties. 18-May-20 02:12 AM Joined the server. 18-May-20 02:13 AM Hello new one! 18-May-20 02:14 AM Hi 18-May-20 02:14 AM Sorry if i ask but does someone have the software for the MKS easyview RGA analyser, i got a cheap offer but with no software and the software is $700. it would be amazing, you guys are my last hope 18-May-20 08:36 AM SRS here, sorry! 18-May-20 09:30 AM @dasd email MKS 18-May-20 09:46 AM if you have any luck with that, please tell me your secret 18-May-20 10:12 AM @dasd email MKS @nmz787 thats why i know that it cost $700 18-May-20 10:14 AM Oh, sorry I misread the RGA was $700 18-May-20 10:14 AM From what I know on general spectroscopy, the database to look up something like fragment patterns to determine the parent compound is the "secret sauce" part 18-May-20 10:14 AM Maybe they have a demo/trial version thay you could use to at least reverse engineer the data protocol? 18-May-20 10:41 AM no just the software is $700 thats more than what i paid for the RGA 18-May-20 10:41 AM unfortunately the dont have a demo/trial Demo version from what i know it is also only available on CD from what i could find out 18-May-20 10:41 AM The new ones have anleast a web server on them so you dont need software but the old ones dont 18-May-20 10:51 AM From what I know on general spectroscopy, the database to look up something like fragment patterns to determine the parent compound is the "secret sauce" part @nmz787 i think for RAG you normally only care about mass and dont need the Database to find out what it was. Like H, O, N ... The protocol and Command are more of an issue, maybe im lucky and someone has Access to a copy or so 18-May-20 12:03 PM Depends on if you're trying to push the RGA to be more than simple gas process stuff I guess 18-May-20 12:03 PM But yeah for simple helium leak and process engineering, I agree fragment reversing shouldn't be needed 18-May-20 01:59 PM I dont just need the basic functionality for simple outgassing mainly and chamber testing, the main things i want to look at are oxygen pressures, that is what that software EasyView does. jup thats really basic. I hate it when you need to buy software additional to the hardware to even use it. but thanks @nmz787 for the input 18-May-20 02:23 PM @dasd what's the interface? Serial/rs232, USB? 18-May-20 02:23 PM Some weird port with no pinout info on what pins are what? 18-May-20 02:28 PM no better Ethernet 18-May-20 02:28 PM it is almost the same as the current version https://www.mksinst.com/f/e-vision-2-residual-gas-analyzer 18-May-20 02:33 PM Hmm, any more cheapo units available? 18-May-20 02:33 PM I've already got an ethernet sniffer setup, but yeah without the software to sniff :/ would be a lot of fuzzing input commands 18-May-20 02:33 PM Might be a way to get the internals to be dumped out and then check for commands 18-May-20 02:39 PM from this kind, depends between 500 to 1500 it a typical price for them. yes without the software there is not much to sniff, jup allot of work for maybe no result, i might look into that but i suspect that they will send allot of hardware parameters and Commands. But i dont think i will be able to get it ruing any time soon. 18-May-20 02:41 PM I see one for $150 18-May-20 02:41 PM Have you seen this? 18-May-20 02:41 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/RGA_SDK_LP102025.100-BAC70.pdf 18-May-20 02:43 PM yes 18-May-20 02:44 PM Only mentions the activex module names tho it seems 18-May-20 02:44 PM It's something at least 18-May-20 02:47 PM jup but still the magic is in the actually library 18-May-20 02:47 PM Yeah but you could imagine they used the same names for plaintext commands going across the Ethernet 18-May-20 02:47 PM So if you could dump the firmware of an internal flash/rom, you might make some progress 18-May-20 02:47 PM I am not seeing any sensor heads for those on ebay, at least with "mks vision" as my search 18-May-20 02:47 PM Not quite the most intriguing project for me at the moment 18-May-20 02:49 PM jup but thats quite allot of work and i dont know mutch about that kind of reverse engineering 18-May-20 02:49 PM Have an old RGA already that I haven't got to installing yet 18-May-20 02:50 PM yes it is hared to finde a full set that makes them sometimes a bit rare 18-May-20 02:50 PM sure i dont want you to solve my problems, your input is quite helpful. But thats means for me if i want to get it running my self it will provably take a year or so. So i will still try to get my hands on the software and $700 is again not that bad compared to the time it will take me, sure i can learn allot but also i could do more exiting things instead. 18-May-20 02:56 PM Yep 18-May-20 02:56 PM Always the predicament 18-May-20 02:56 PM Ugh, now my FIB computer doesn't want to boot up reliably 18-May-20 02:57 PM true but money is often the bigger problem than time ^^ 18-May-20 02:57 PM Ugh, now my FIB computer doesn't want to boot up reliably @nmz787 18-May-20 02:58 PM I get caught up because I'm always like "well if I learn this skill, it'll probably save me money or time in the future" 18-May-20 02:58 PM But often it's probably less of an overall investment to just pay big bucks and work it off with day job 18-May-20 02:58 PM But like, for my FIB, support is non-existent pretty much 18-May-20 02:58 PM Unless I have $100k for a year of service contract 18-May-20 02:58 PM Which, I do not 18-May-20 03:00 PM yes thats a whole other sorry, that without server contract you are out of luck. 18-May-20 03:01 PM It's back to the whole reverse engineering quest 18-May-20 03:03 PM But often it's probably less of an overall investment to just pay big bucks and work it off with day job @nmz787 yes that is what i often fall back to, my free time for my hobby projects is already scarce at best, so i often just want things to work but than in this case that means again quite the investment for such a "basic" thing 18-May-20 03:03 PM It's back to the whole reverse engineering quest @nmz787 jup 18-May-20 03:22 PM Not what I want to be seeing 18-May-20 03:22 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200518_012027-A3BA6.jpg 18-May-20 08:18 PM My big concern with trying to reverse engineer that would be the quadrupole control aspect. I've never tried I guess, but I would imagine it's not trivial . The database, if it comes with that, would also be very expensive and definitely worthless for an RGA used as an RGA, but I'm not sure why it would come with that in the first place. 18-May-20 08:18 PM Unless it's just serial commands where some control unit does the heavy lifting in which case it'd be easier but basically impossible to reverse engineer without the software :/ 19-May-20 01:19 AM Not what I want to be seeing @nmz787 not so nice 19-May-20 01:19 AM My big concern with trying to reverse engineer that would be the quadrupole control aspect. I've never tried I guess, but I would imagine it's not trivial . The database, if it comes with that, would also be very expensive and definitely worthless for an RGA used as an RGA, but I'm not sure why it would come with that in the first place. @Mezmorizor yes reversing it would be huge undergoing if even feasible, thats why was looking for the SW 19-May-20 01:11 PM A bit of google-fu found the (I believe it's a cumulative suite sort of situation) software install and manual CD's, PM'd them @dasd 19-May-20 05:09 PM @Metanoic I'm interested too 19-May-20 05:09 PM Using filetype:exe or msi didn't give me decent looking results 20-May-20 09:05 PM Hi there! I'm trying to diagnose issues with an MKS Baratron 222 AHS gauge connected to a MKS PDR-C-1A controller. As I understand it, the controller is just a DMM displaying the output voltage. I have a 10 Torr unit and the output is 0-10V, so presumably 1000 mV => 1 Torr. However, while the gauge responds to vacuum, I see negative readings. Does my understanding of all of this sound accurate or am I misinterpreting the output? Thanks! @nmz787 I think you worked with these? 20-May-20 09:05 PM that is, I think something is wrong since my theory of operation indicates I should not see large negative readings 20-May-20 09:06 PM I haven't worked with them, just knew that's what I should get when I need to 20-May-20 09:06 PM Are you sure you're reading the datasheet correctly, if you have one? 20-May-20 09:06 PM Maybe it's 10-0V?? 20-May-20 09:06 PM Also the response may not be linear 20-May-20 09:08 PM Unfortunately I can't find a datasheet for my specific sensor, but it seems pretty comparable 20-May-20 09:08 PM https://www.ebay.com/itm/MKS-Baratron-222AHS-B-A-10-SP53-80-S-N-62245-10Torr-CAJON-VCR-1-2-Fitting/172576141153?hash=item282e56ef61:g:LYYAAOSw4CFYyJI5 20-May-20 09:08 PM At least that's what I saw from a lookup table in the mks901p datasheet 20-May-20 09:08 PM You can see a very similar unit label on ebay there 20-May-20 09:08 PM Linearity aside, going far below 0 to me indicates there is something more fundamentally wrong. However, I've considered adjusting the cal pot to see if I could correct it 20-May-20 09:10 PM Hmm you're checking between output and common? 20-May-20 09:10 PM Yes. Its worth mentioning the next action item is to put an external DMM on that line and see what it reads 20-May-20 09:12 PM Do you have another gauge on the system to compare against? 20-May-20 09:12 PM Something like a 901p? 20-May-20 09:12 PM tldr no, but I could add something closer to the pump possibly 20-May-20 09:12 PM Having a cal pot sounds like maybe that could change things 20-May-20 09:12 PM But you'd need a reference 20-May-20 09:13 PM I have a large stack of gp275's here. I could get something not great but at least approximately the same pressure zone 20-May-20 09:13 PM they also seem to generally work well and read consistently between them 20-May-20 09:18 PM Hmm, they look a little less easy to work with than the 901p 20-May-20 09:18 PM But maybe wait for someone else here to chime in 20-May-20 10:38 PM you're powering it with the controller? do you have ±15V handy? 20-May-20 10:38 PM also probably obvious but f there's a signal ground make sure you're not tying it to chassis ground 20-May-20 10:38 PM i wouldn't noodle with the cal pot just yet 20-May-20 10:38 PM knock on wood 22-May-20 01:22 PM @GigaSquirrel did you do anything special to balance the rotor after you chopped off part of that blade? 22-May-20 01:24 PM I mean chipping off the blade was the balancing 22-May-20 01:25 PM That's way too funny. I'm inspired to try to fix mine. 22-May-20 01:25 PM That requires machining aluminum. I need to make a tool to pull the ring that's holding the magnet bearings. 22-May-20 01:27 PM lemme guess, turbovac 150/360? 22-May-20 01:27 PM or 151/361 22-May-20 01:28 PM And that requires the state to reopen so I can get machine shop access again 22-May-20 01:28 PM No, Edwards EXT70 22-May-20 01:28 PM Smol turbo 22-May-20 01:28 PM oh, I didn't know others did that as well 22-May-20 01:30 PM I need to source a ball bearing. 22-May-20 01:30 PM Magnet rings. 22-May-20 01:30 PM Hope I can reassemble the thing without cracking the magnets 22-May-20 01:30 PM And then either source felt, or clean the felt in there, to hold lubricating oil. 22-May-20 01:33 PM oh wow what happened to it that it needs a new magnetic bearing? 22-May-20 01:33 PM Magnets cracked. 22-May-20 01:33 PM The outside ones were cracked. 22-May-20 01:33 PM The inside ones were fine, until I let them jump together and they cracked themselves. 22-May-20 01:33 PM All rotors and stators appear perfect. 22-May-20 01:35 PM huh, well 22-May-20 01:36 PM The lower ball bearing completely ate itself. 22-May-20 01:36 PM I'm not sure how the upper magnets could crash like that without destroying the safety bearing or damaging the rotor/stator stack. 22-May-20 01:39 PM ideally they should not crash at all 22-May-20 02:18 PM Spirit posted a great writeup and video on doing the same 22-May-20 02:18 PM https://spirit.re/projects/ext255h.php 23-May-20 12:30 PM That’s a great link. 23-May-20 12:30 PM That addresses my question of finding the right kind of felt. 23-May-20 12:30 PM The felt is actually of different thickness. The rings are 2x the thickness of the part that wicks oil to the conical nut. 25-May-20 04:39 PM Does anyone here have experience making liquid nitrogen vacuum feedthroughs? 25-May-20 04:42 PM I just designed one if that counts at all, though I haven't even built it yet so.... 25-May-20 04:42 PM Also not UHV 25-May-20 04:42 PM Basically just using a rather wide PTFE disk to mostly thermally isolate the LN2 tubing from the chamber wall, but it's for intermittent use only, not for continuous flow 25-May-20 04:42 PM And then a lot of thermal insulation on the atmosphere side abutting the disk. 25-May-20 04:45 PM Yeah, very different from what I want haha 25-May-20 04:45 PM I'm working on welded stainless, for ~1E-9 torr. Trying to figure out the dimensions to use for a large diameter tube using this sort of tube-in-a-tube insulation: 25-May-20 04:45 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-BE462.png 25-May-20 04:46 PM The tubing is initially surrounded by a vacuum baffle to extend some distance away from the chamber while keeping vacuum insulation, but eventually I needed a valve (also solid PTFE) and an opening to dispense it from 25-May-20 04:46 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-BA64C.png 25-May-20 04:46 PM Oh that doesn't look all that different from what I just said about a baffle, weirdly 25-May-20 04:46 PM It's the same mechanism as any commercial feedthrough 25-May-20 04:47 PM But yeah you can't likely use PTFE here at the end for the annular region 25-May-20 04:47 PM I just need it to support quite a bit more weight than 1/4" tube and we're gonna be pouring liters of LN2 in so ~0.75" or 1" diameter is needed 25-May-20 04:48 PM Yeah that makes sense-- mine literally is just 1/4" diameter PTFE tubing at the center 25-May-20 04:48 PM It's to hang a big stainless tank in the middle of the chamber: 25-May-20 04:48 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-4E233.png 25-May-20 04:48 PM A difficult thing because normally just overbuilding stuff is easy, but here "overbuilding" gives better thermal contact... Which of course is bad. 25-May-20 04:50 PM Yes I see the issue 25-May-20 04:50 PM Hmm one thing I did for unrelated reasons also was run the tubing in a sort of S shape from the central reservoir 25-May-20 04:50 PM Maybe that could help here too? 25-May-20 04:50 PM I did it to control the effect of boiling near the exit port 25-May-20 04:50 PM But if you're working in stainless instead of PTFE then it could also have meaningful thermal conductivity reduction benefits 25-May-20 04:50 PM I'm also not sure whether you are able to somehow decouple the load bearing functionality from the pass throughs. Less thermally conductive low-outgassing open celled structural support materials exist of course 25-May-20 04:56 PM Anecdotally I know that straight tubes with this design aren't problematic if it's designed properly, a fill in the morning lasts until the evening 25-May-20 04:56 PM and making it easier to make is worth quite a bit to me 25-May-20 04:58 PM Fair enough, just brainstorming ways to decrease thermal conductivity without losing much mechanical strength. Sorry I don't know enough to be of much help. 25-May-20 04:58 PM Useful cross check for mine, though, and appreciated 25-May-20 05:06 PM This is not something I have any experience with but I am just wondering if you really gain that much in thermal isolation from the double wall tube given the increased surface area... 25-May-20 05:13 PM The loop up and around is to allow room for thermal contraction 25-May-20 05:13 PM So only the part outside the vacuum chamber is double walled 25-May-20 05:15 PM Ahh so it is for more than just trying to minimize conduction? 25-May-20 05:15 PM Pretty much all feedthroughs do that: 25-May-20 05:15 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/single-tube-ln2-feedthrough-200-5A873.png 25-May-20 05:15 PM Yeah it reduces stresses a lot. 25-May-20 05:15 PM I have only ever seen a couple LN2 traps and they were both just pipes welded to flanges with a large reservoir 25-May-20 05:16 PM Visually it's often hard to see but this is definitely the norm / recommended way to do it 25-May-20 05:24 PM For flexible variants, woven fiberglass sleeves are often used to hold the inner tube away from the baffle walls. Not relevant here, just may be of more general interest. Multi layer radiative insulation is also common and very easy to make. I am using it. 27-May-20 06:42 AM I just got a mks 902, is there any software for that? 27-May-20 06:42 AM looks like the mks software costs money 27-May-20 09:32 AM not sure if the 902 is the same as the 902B but from a look at the manual it seems they use the same basic communication protocol that the 901P uses 27-May-20 10:30 AM What sort of software would you want for a vacuum gauge with an open protocol??? 27-May-20 10:35 AM dunno, that's why I was curious if there is any 27-May-20 10:35 AM like an easy configuration, maybe graphing etc 27-May-20 10:36 AM here one sec 27-May-20 10:37 AM you can do it really easily with an arduino/esp32/etc, rs232-ttl converter(assuming the 902 is rs232), and some quick code 27-May-20 10:37 AM what's the easiest way to send you a 350MB file? 27-May-20 10:37 AM sent by dm 27-May-20 10:37 AM No idea if it's useful but that's the MKS 900 series driver DVD they include with all of them. 27-May-20 10:37 AM I just used the analog output on mine 27-May-20 10:37 AM if you want I can mail it to you, I had to rip the miniDVD but we have four... 27-May-20 10:42 AM Thank you, I'll look into it! 27-May-20 12:00 PM @idmb megaupload 27-May-20 02:32 PM You might want to check for EPICS drivers. If it might get used on a beam line, there’s a good chance there’s an EPICS driver for it. 27-May-20 03:42 PM I thought the MKS 900 series just spit out serial data. 27-May-20 04:28 PM any comsol users on here? having trouble w/ deformed mesh module and wanna make sure I’m not crazy 29-May-20 08:33 AM Has anyone built a hard/soft-wall cleanroom in their home lab? If so, what are some resources to look into? I'm aiming my budget at a buying/building apparatus, thus; I'd like to make their home übercheap. What are some hacks towards building perspicaciously so that I might be able to improve my classification potential over time? 29-May-20 09:02 AM Wow, I only made a negative pressure fume hood, didn't reach that far. 29-May-20 11:06 AM think @qualia was talking about building something similar on twitter 29-May-20 11:06 AM I don’t know what class you could get to but the general consensus was that you could get a good bit out of just hanging plastic sheeting and a hepa filter if you want a soft wall one 29-May-20 11:06 AM https://books.google.com/books/about/Midsize_Facilities.html?id=JW9xRUBs8UYC&source=kp_book_description this book may have some interesting things but I haven’t looked for a free copy 29-May-20 11:33 AM The one we got installed at work is like a ISO 8 and is basically that 29-May-20 11:33 AM plastic sheets and a filter 29-May-20 11:35 AM some of my work has just been me trying to get my labspace to be less dusty in general, lol. similar end goal though.. i've been goofing around with box fans and house AC air filters a bunch lately. haven't hung any plastic just yet 29-May-20 11:35 AM will have to check that book out 29-May-20 11:36 AM It may not be totally relevant but if your ever trying to set up a materials lab for institution wide use ‍♂️ 29-May-20 11:36 AM i like to pretend i'm doing much more important work than i actually am so that'll do 29-May-20 11:36 AM but yeah.. i have a couple of pms5003t laser particulate sensors knocking around, soldered to USB FTDI transceivers & logged into influxdb+displayed in grafana. i plan to get the ambient dust level & contributors thereof down a bunch first, then i'll start hanging up plastic from the rafters & hooking MERV 37 ULPA filters to grow tent duct fans and other such shenanigans 29-May-20 11:36 AM box fans have kinda awful static pressure so at least in the filter-taped-to-inlet configuration they don't like greater than MERV 7 filters or so 29-May-20 11:36 AM i'm also kinda on the lookout for other particulate sensors, 'cos pms5003s have the benefit of being cheap but also the downside of being cheap. dunno how accurate they are.. and one has some stuck sensor readings, i think 29-May-20 01:15 PM @pasta 29-May-20 01:15 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/B0C5543C0A04_2020-04-13_02-38-29-76DEC.jpg 29-May-20 01:15 PM @pasta http://diyhpl.us/~nmz787/pdf/smi3200/pics.html 29-May-20 01:15 PM Just painters plastic stapled to 1x2 wood which was screwed to the ceiling, and on the floor the plastic was siliconed to soap+water cleaned cement floor 29-May-20 01:15 PM I had a chance to get some 2' x 4' ceiling hepa units for like $150 but failed to purchase them, so I just have a simple room filter inside at the moment 29-May-20 01:33 PM @Nixie I'm taking a shot a growing some 2D superlattices with a hybrid solution/vacuum(SILAR/RF-Sputter) process. You have me thinking that, for now, I can scrap for some old restaurant hoods parts and make a fume hood that I could eventually fashion into a modular glovebox of sorts. (I work in sheet metal enclosure integration) As much as I want to avoid making my own pressure vessels, I would venture into this route should it take-up less overall space and be rather handy to create inert environments. Thoughts? 29-May-20 01:33 PM @mike crb Thanks, this is exactly the kind of thing I was looking for... if only micro-micro facilities was an academic topic of interest... 29-May-20 01:37 PM I'm of the school of do everything yourself, so I can only say go ahead. ^^ You sound like you have plenty of experience to build something great. 29-May-20 01:37 PM Also, the fact that if you buil it yourself, you can design it to your own specs both in form and function. 29-May-20 01:48 PM @qualia These digital universal particle sensors look neat. Where exactly do you have the sensors placed? Do you think I could run a few on the same FTDI/influxdb/grafana stack on a dedicated rasberry pi? might you do it different?I'm dually jaded and understudied in this sensing regime. I've spent good bit of time studying aerosol physics and it's one of my main areas of interest for building new apparatus (aerosol synthesis/thermophoretic deposition) If you interested, currently at the nexus of detection & fab https://aerosol.us/ which is building polydiverse particle sorting and spectroscopy devices of which they show off a bit. 29-May-20 01:56 PM @nmz787 Nice shop, nice hacks. I think my embodiment will be similar to this, alight I would like to go for it with achieving a laminar down-draft 29-May-20 02:17 PM I got one of these particle sensors https://www.amazon.com/gp/aw/d/B0787H244V 29-May-20 02:17 PM Uses laser diffraction or something 29-May-20 02:18 PM a raspi4 would totally run the whole stack, plus as many USB devices you can fit into it (use a powered hub for maximum reliability). i run influx/grafana in a vm on a server in the garage 'cos i use it a lot of different monitoring. my sensors kinda move around a bunch, currently they're dangling from the ceiling in the center of my room 29-May-20 02:19 PM Oh, looks like that's the same thing qualia mentioned 29-May-20 02:22 PM oh, yep, same sensor 29-May-20 02:22 PM ebay has em cheaper if you can stomach the slow-boat delivery 29-May-20 02:22 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_2020-05-29-14-21-36-6EBBA.png 29-May-20 02:22 PM the data output is a little weird and the response time isn't incredible but they definitely show a measurable difference in different environments 29-May-20 02:37 PM nice interface! 29-May-20 02:46 PM @qualia How easy is it to get started with Influx? 29-May-20 02:46 PM I've been using Ubidots to send data from a stm32 MCU and visualize/plot them, and I have to say it's been quite lackluster. Lots of stuff to troubleshoot, lots of time I don't want to invest into what should be saving me time 29-May-20 04:23 PM just bought a platinum GIS for my FIB, and made an offer on a injector needle and crucible (possibly with Platinum inside) 29-May-20 04:23 PM @Mason_Yu this looks like a decent guide http://embedonix.com/articles/embedded-projects/setting-up-influxdb-and-grafana-for-storing-and-viewing-arduino-measured-sensor-values/ 29-May-20 04:32 PM Ah, that's actually pretty simple. I can probably use an Arduino as a separate data logger to forward all of the time-series data over ethernet, instead of having to write my own libraries to work with Ubidots 29-May-20 04:32 PM I was also thinking about writing a simple webserver directly from the Arduino IDE, and use the super cheap ESP32 as the wireless link through WIFI, it'll enable more than data logging, but include simple switches and stuff as well 29-May-20 04:32 PM https://lastminuteengineers.com/creating-esp32-web-server-arduino-ide/ 29-May-20 04:32 PM But I certainly can't argue with the very nice plots from grafana and the optimizations done to Influx 29-May-20 04:46 PM And if plotting needs to be done on a custom HTML webpage, I think some libraries are available and quite easy to use 29-May-20 04:46 PM https://www.highcharts.com/ 29-May-20 05:06 PM oh yeah, ESP chips are super nice 29-May-20 05:06 PM I mostly just use "arduino" as a search term since the results are usually pretty DIY friendly and often comprehensive 29-May-20 10:23 PM Joined the server. 30-May-20 03:13 AM Whee, the seller accepted my low-ball offer for the platinum injector needle and crucible (possibly with platinum precursor in it)! 1/3 their asking price!! 31-May-20 06:59 PM what's the platinum injector needle for? 31-May-20 06:59 PM just got the ESP32-S2, missing a bunch of features that standard ESP32 has but it has WiFi ToF, interested to see what it's capable of 31-May-20 07:07 PM regarding graphing convo above, could be an interesting architecture to have the ESP32 run the web server (+mdns for easy discovery, http://graph.local), but for it to send a redirect to a cloud-based graphing engine with info about the types of data available, then the graphing engine (on cloud or lan) uses the referrer (or url param) to hit the ESP32 for the actual data, so the ESP just spits out data via websocket... 31-May-20 07:07 PM that could be really cool as many people could use the graphing engine and it could be constantly updated and improved without any code changes on the MCU as it's just the data source 31-May-20 07:25 PM the multi-device communication (computer/phone + MCUs) has been a common annoyance on projects for me so have been working on a language that allows shared memory/interrupts/functions between MCU+host. you write a single program to read your sensors/GPIOs/etc from then can immediately graph it or get interrupts for new data without having to deal with two programs, communication/protocol, etc, as if the MCU was part of the machine. if anyone else deals with stuff like this normally, would love to hear any suggestions that could improve your own workflows or potential issues 31-May-20 09:22 PM i wonder if you can produce an isolated lower-pressure area in a vacuum chamber through a standing sound wave by vibrating the walls (with what little air is left) 31-May-20 09:46 PM @samy injector needle will go onto the GIS (gas injection system) unit... It's basically a bellows with a heater coil, and being a bellows can extend or contract (via pneumatics). The needle has a crucible near the heater, filled with a compound that can be volatilized with heat. In my case the needle/crucible (might, fingers crossed) have a Platinum compound in. The needle has a plunger that acts as a (needle) valve, also actuated pneumatically. 31-May-20 09:46 PM Combining it all, you can precisely move the tip of the needle inside a vacuum chamber. And emit the volatile gas at the local area. 31-May-20 09:46 PM Getting gas molecules in an e-beam or ion beam path, basically turns the setup into a 3d printer with roughly beam size resolution 31-May-20 09:46 PM So in FIB, without gas you're milling/etching, and with gas you can deposit material. 31-May-20 09:46 PM I've already got a GIS for carbon deposition (basically used as an etch stop or protection layer)... But I want metal deposition to have the potential for doing chip circuit edit, or adding electrodes to MEMS stuff during prototype stage fab 01-Jun-20 10:30 AM @nmz787 that sounds awesome 01-Jun-20 10:48 AM Play gas-phase billiards! 01-Jun-20 11:11 AM I’ve gotten to use the GIS on our dual beam a few times and it is pretty awesome 01-Jun-20 12:29 PM @nmz787 that sounds amazing. how fancy of a system do you need for milling/etching + deposition for IC editing? what sort of nm tech can it affect? 01-Jun-20 01:45 PM My machine is specced at having a 4nm spot size at the smallest beam current 01-Jun-20 01:45 PM Pretty much any machine from the mid 90s will have such potential/capabilities 01-Jun-20 01:45 PM Usually circuit edit is done on the interconnect or wires as far as I know... i guess you could wire something to a transistor but I haven't checked 01-Jun-20 04:25 PM Joined the server. 01-Jun-20 05:01 PM I'm currently attaching this old Ga FIB to my SEM, pretty old but in perfect condition 01-Jun-20 05:01 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200502_211625-3232E.jpg 01-Jun-20 06:52 PM Nice! 01-Jun-20 06:52 PM I want to add a SEM column to my Seiko FIB 01-Jun-20 06:52 PM What model is that? 01-Jun-20 06:52 PM I've only used FIB200 when it comes to FEI 01-Jun-20 09:58 PM This is model 1LI 02-Jun-20 12:45 AM Huh, never heard of that one 02-Jun-20 12:45 AM It looks like it might be easier to interface with than the more computerized models 02-Jun-20 12:45 AM I'm just finishing up work here with two FIB200s behind me 02-Jun-20 12:45 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200602_004716-FD39C.jpg 02-Jun-20 01:08 AM Welcome! 02-Jun-20 01:18 AM yes pretty old one but luckily several originally packaged Ga-LMIS and complete circuitdiagrams are there 02-Jun-20 03:09 AM I've got a guy up the street who refills Ga LMIS, gonna get him to do mine when the time comes. Probably will get him to teach me too. 02-Jun-20 03:09 AM The circuit diagrams are pretty much the key 02-Jun-20 12:16 PM What are you guys using for polishing UHV parts? 02-Jun-20 12:17 PM you mean like after fabrication? 02-Jun-20 12:44 PM yes and for cleaning purposes 02-Jun-20 12:44 PM i think at the university we use Unipol Metal polish 02-Jun-20 12:44 PM and afterwards ofcourse ultrasonic cleaning 02-Jun-20 12:51 PM for welded stuff I electropolish with phosphoric / sulphuric acid 02-Jun-20 12:51 PM that leaves a matte finnish 02-Jun-20 01:55 PM I take it that passivates the stainless? 02-Jun-20 01:58 PM both passivates and removes the colors (oxide layer?) 02-Jun-20 03:54 PM Wow my GIS from Israel got sent DHL and is apparently gonna be here by end of day 02-Jun-20 04:57 PM Any instructions on what you're doing? Concentrations, voltage/current, what's the other electrode, time, etc.? 02-Jun-20 05:17 PM it's a carbon fiber brush, some phosphoric acid with a dash of sulphuric acid and 5 or 10 amps @GigaSquirrel 03-Jun-20 06:51 PM Anyone seen this before? 03-Jun-20 06:51 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200603_185031-99B0E.jpg 03-Jun-20 06:51 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200603_185041-36991.jpg 04-Jun-20 03:41 AM Looks a lot like an old quadrupole mass analyzer: right length and thickness, characteristic attraction and neutralization-grid inside the top, two bnc's on HV Coax probably going to the two pole pairs and the big d-sub'ish connector with the fat possibly teflon insulated coaxer and wire bundles for powering the filament, supplying optics voltages and charge readout. You may be able to remove the entire knurled SS cylinder from the assembly to expose a bunch (~9-14) of pins feeding through the back DN63CF flange. Any context? 04-Jun-20 12:53 PM Was at an auction strapped to a half rack cart with plywood shelves with an interface box that pushed another crazy looking dsub connector out of it. A second cart came with it but it looked independent. It's also important to note that that grid in there is loose. 04-Jun-20 07:46 PM Joined the server. 06-Jun-20 08:01 AM Joined the server. 06-Jun-20 08:01 AM hi 06-Jun-20 08:02 AM welcome back 06-Jun-20 08:05 AM saw that on twitter 06-Jun-20 08:05 AM the invite 06-Jun-20 08:05 AM and remembered 06-Jun-20 08:06 AM how could you forget us 06-Jun-20 08:06 AM dunno 06-Jun-20 08:06 AM time maybe 06-Jun-20 08:06 AM other stuff to do 06-Jun-20 08:06 AM building lasers and vacuum stuff 06-Jun-20 08:07 AM ohh nice 06-Jun-20 08:08 AM yes. 06-Jun-20 08:09 AM pics? 06-Jun-20 08:12 AM only simple UHV stuff 06-Jun-20 08:12 AM and primitive ECDL 06-Jun-20 08:12 AM and some cheap optical spectrum analyser hacks to measure their quality 06-Jun-20 08:12 AM nothing worth to showing off imho 06-Jun-20 08:12 AM the high density/"pin" count feed through could be of interest - if I figure out how to sinter it correctly 06-Jun-20 08:12 AM ah and has anyone in here experiences with DIY NEG? 06-Jun-20 08:29 AM Joined the server. 06-Jun-20 08:39 AM I know ... ECDL are hated and I had a couple of discussions within the last months with people "knowing their stuff" about how crppy and unreliable they tend to be 06-Jun-20 08:39 AM but on the other side in my experience 06-Jun-20 08:39 AM ecdl go brrrrr 06-Jun-20 08:39 AM anyways integrating NEG stuff in a chamber partially made out of ceramics would be pretty awesome, right? 06-Jun-20 08:39 AM esp for sealed stuff 06-Jun-20 08:52 AM Joined the server. 06-Jun-20 10:06 AM in earlier times there were more messages per hourz 06-Jun-20 11:24 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-D4BE1.jpg 06-Jun-20 11:58 AM Joined the server. 06-Jun-20 01:42 PM Joined the server. 06-Jun-20 01:44 PM Joined the server. 06-Jun-20 01:54 PM Joined the server. 06-Jun-20 02:00 PM Joined the server. 06-Jun-20 03:38 PM well that's a flood of people! 06-Jun-20 03:44 PM Welcome new folks! 06-Jun-20 03:50 PM Hiaa 06-Jun-20 03:52 PM For all the new people, take a look at #introductions_and_directory 06-Jun-20 06:11 PM I think a lot of us may have come from a tweet Niklas sent out 06-Jun-20 11:19 PM YAY NEW FRIENDS 07-Jun-20 01:39 AM Joined the server. 07-Jun-20 07:25 AM Joined the server. 07-Jun-20 07:28 AM Joined the server. 07-Jun-20 07:41 AM friendsforever 07-Jun-20 07:58 AM Even more people! 07-Jun-20 11:06 AM <𝓕ermion#6024> does anyone know who or what rue mohr is? 07-Jun-20 11:06 AM <𝓕ermion#6024> I've been tinkering for a long time and I've never talked to anyone more like... consistent than him. 07-Jun-20 11:08 AM consistent in what way? 07-Jun-20 11:09 AM <𝓕ermion#6024> seemingly very no-bs and productive. 07-Jun-20 11:09 AM <𝓕ermion#6024> nothing overly fancy 07-Jun-20 11:09 AM ah, right 07-Jun-20 11:10 AM <𝓕ermion#6024> like very impressive at making things from scrap 07-Jun-20 11:10 AM I wan't aware of them until a few weeks ago, some very impressive things indeed 07-Jun-20 11:10 AM <𝓕ermion#6024> I'll put it this way... I don't think I've ever seen something from him that was either over or under-engineered 07-Jun-20 11:11 AM Sounds like a minimalist of a maker, just right to get the job done 07-Jun-20 11:11 AM <𝓕ermion#6024> I've talked to him like once every two years in #robotics for at least 15 years. 07-Jun-20 11:11 AM <𝓕ermion#6024> and he's the exact same person with the exact same philosophy every time 07-Jun-20 11:11 AM send him an invite to here 07-Jun-20 11:24 AM @fermion is that on freenode? 07-Jun-20 11:54 AM why is aquadag so expensive? 07-Jun-20 11:54 AM has anyone ever tried making their own? 07-Jun-20 12:09 PM @GigaSquirrel We are using some homemade alternative (I think some "ordinary" coloid graphite mixed with methanol), I can try to have a look tomorow on details... 07-Jun-20 12:09 PM cool! 07-Jun-20 12:09 PM what's your binder? 07-Jun-20 12:09 PM I'm trying to find ratios here, wiki says it's graphite, agar, ammonia and water 07-Jun-20 12:10 PM Not sure, have to ask coleagues - its quite old box 07-Jun-20 12:10 PM awesome, thanks! 07-Jun-20 12:27 PM i looked into the origins of it awhile ago and it did not seem too hard or annoying a process but i have no idea if the 1907 patent related method is really what the current product is produced with 07-Jun-20 12:27 PM https://sci-hub.tw/10.1109/PAIEE.1907.6742299 07-Jun-20 12:27 PM that paper discusses the production of "deflocculated graphite" which is what Aquadag seems to be based on 07-Jun-20 01:00 PM Joined the server. 08-Jun-20 12:02 AM Joined the server. 08-Jun-20 04:53 AM @GigaSquirrel We are using this old thing - it is (probably) Moly-Paul 749. Unfortunately it seems quite outdated and already not in production... 08-Jun-20 04:53 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-3357D.jpg 08-Jun-20 04:54 AM noice, thanks! 08-Jun-20 07:12 AM I have made my own aquadag. I oxidized some nickel and then put that in a quartz tube one end connected to a flask of boiling IPA. Then induction heated the nickel to redness. The vapors would dissociate on contact with the hot nickel and a ultra fine powder would accumulate. After each build up I would rinse off the accumulation into a small evaporating dish with Alcohol. It was the finest powder you could imagine. I would then mix it either with nitrocellulose, or sodium silicate, or TEOS, or whatever I needed at that moment. Sometimes just a water suspension. Worked great. 08-Jun-20 01:57 PM Joined the server. 08-Jun-20 04:48 PM Joined the server. 08-Jun-20 05:49 PM We've recently done a lot of work on one of our high vacuum chambers, and the pressure in the chamber and foreline is normal at room temperature, but when we turn on the cold head it doubles in both. Any idea what's causing this? Is it just thermal contraction ruining some metal-metal joint in there? 08-Jun-20 05:49 PM @𝓕ermion Pinging because you're the cryo expert 08-Jun-20 05:49 PM <𝓕ermion#6024> MEEE?! 08-Jun-20 05:49 PM <𝓕ermion#6024> oh hmm 08-Jun-20 05:49 PM <𝓕ermion#6024> maybe there's a really tiny leak in the cold head or something 08-Jun-20 05:49 PM <𝓕ermion#6024> but that seems unlikely? 08-Jun-20 05:49 PM <𝓕ermion#6024> yeah dang that's really weird 08-Jun-20 05:52 PM I mean, you did a PhD in quantum computing lol 08-Jun-20 05:53 PM <𝓕ermion#6024> what's the timescale on the pressure rise? 08-Jun-20 05:53 PM <𝓕ermion#6024> does it shoot up as soon as the PTC turns on? 08-Jun-20 05:53 PM <𝓕ermion#6024> or is it a slow rise? 08-Jun-20 05:53 PM Let me ask. I'm more relaying what a lab member is asking in slack lol 08-Jun-20 05:53 PM Still not actually back at work yet 08-Jun-20 06:08 PM <𝓕ermion#6024> I imagine the PTC might flex and jiggle a bit as it runs 08-Jun-20 06:08 PM <𝓕ermion#6024> it sounds like a bad joint either way 08-Jun-20 06:08 PM <𝓕ermion#6024> like you might hook up a leak checker and see if the dominant gas is helium. 08-Jun-20 06:08 PM <𝓕ermion#6024> err... an RGA rather 08-Jun-20 06:08 PM <𝓕ermion#6024> the working fluid in these pulse tubes is helium I think. 08-Jun-20 06:08 PM <𝓕ermion#6024> so if the PTC is leaking when it runs then maybe you can see that 08-Jun-20 06:08 PM <𝓕ermion#6024> otherwise it's a joint somewhere 08-Jun-20 06:08 PM <𝓕ermion#6024> either it's wiggling or flexing as it runs due to the pressure fluctuations or as you suggest it's some bad joint and thermal contraction 08-Jun-20 06:11 PM Have you run it with a shut foreline to measure gas load vs. time? Helium system pressure would ish double when on, right? 08-Jun-20 06:27 PM Pressure probably hasn't killed it (negligible elasticity, tiny surface area to tensile strength ratio) but the thin indium seals usually do have a limited thermal cycle life, and they can creep when warm. Old head or any heavy regeneration cycling recently? 08-Jun-20 07:29 PM @Mezmorizor is that with helium going through a nozzle on the cold head? there's a pressure increase even with low backing pressure 08-Jun-20 07:42 PM Should be low pressure going through, but it's abnormally high 08-Jun-20 07:56 PM Maybe your nozzle is damaged? 08-Jun-20 07:56 PM Cold head with no flux should lower pressures through cryopumping 08-Jun-20 07:56 PM Ours does. 08-Jun-20 08:06 PM Oh god, that would be worst case scenario. There's like...4 of those nozzles in the world 08-Jun-20 08:06 PM Which granted we have all of them but still 08-Jun-20 08:06 PM Not like we can get more once they all go kablooey 08-Jun-20 09:28 PM Isn’t the aperture replaceable??? 08-Jun-20 09:30 PM It is, but that's the part that's archaic. We have a handful of extras, but it's "UNC machine shop from the 90s" design, so when they're done they're done 08-Jun-20 09:30 PM Especially because it's weird and complicated 08-Jun-20 09:30 PM One day that instrument will get a modern nozzle, but hopefully I'm not there when it does 08-Jun-20 09:30 PM (also maybe not because my boss wants to move to synchotron work on large amplitude motions, but that's another story) 08-Jun-20 10:34 PM Hi @Dennis W7pF (I'm the one who sent the invite in the microscope mailing list) 09-Jun-20 02:26 PM Good afternoon, all! 11-Jun-20 05:59 AM Joined the server. 11-Jun-20 06:01 AM Welcome! 11-Jun-20 06:01 AM I think I know you, are you here for turbo pump support? ^^ 11-Jun-20 06:01 AM Hi. 11-Jun-20 06:01 AM That must be a coincidence. But yes I could use some help in that regard. 11-Jun-20 06:05 AM ah well, I just invited someone for that reason 11-Jun-20 06:10 AM He probably didn't want so much attention. 11-Jun-20 06:12 AM ¯\_(ツ)_/¯ 11-Jun-20 06:16 AM I'll sent fotos of the pumps later. At the moment they are not in reach. 11-Jun-20 11:01 AM omg 11-Jun-20 11:01 AM i think i know why my trivac hasn't been getting down to pressure 11-Jun-20 11:01 AM after opening and reopening and reassembling multiple times 11-Jun-20 11:01 AM i bought Leybonol LVO100 (recommended) oil from someone on ebay. i just went to confirm and it's actually Leybonol LVO210 (after the first shipment was damaged and never reached me) 11-Jun-20 11:01 AM i hope that's the issue. will try to compare viscosity, but might make sense because i got down to ~1 torr for less than a minute before it went back up 11-Jun-20 11:01 AM so maybe once heated up was not viscous enough? 11-Jun-20 12:29 PM so maybe once heated up was not viscous enough? @samy maybe the vapor pressure of hot LVO210 isn't low enough? 11-Jun-20 01:39 PM interesting, i don't actually understand how that relates/works, i'll look into it (and try to get some proper oil) 11-Jun-20 05:20 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200611_171910-67771.jpg 11-Jun-20 05:20 PM There we go 11-Jun-20 05:20 PM Grid's got two filament wires on the insides, and it was entirely free floating inside of there. I'm surprised they didn't get pinched apart. 11-Jun-20 05:20 PM Oh, one filement, pardon. 11-Jun-20 06:03 PM And that's that outer cage I'm referring to as the grid on the left. I realize the top of the gun(?) Also has a grid. 11-Jun-20 06:17 PM @Laughing what is that? sublimation pump? 11-Jun-20 06:35 PM I have no idea 11-Jun-20 06:36 PM looks like a weird oversized ion gauge 11-Jun-20 06:36 PM I'll have to get better pictures of the tip next time 12-Jun-20 01:54 AM Oo, purely coax feeds! Still almost certainly a Quadrupole Mass Analyzer. I'm guessing there's four of these screw hole collumns around the device? I'd probably also guess those four metallic blocks on top are connected straight down to the fed-through rods below all around, possibly the middle feedthrough on both sides are for the filament. Bottom case almost certainly holds a faraday cup and maybe a few dynode stages. You should be able to remove both the cylindrical and rectangular casings to see the Inside quad rods. If the case was bulging and had far more room it could have been a Cylindrical Mirror Electron Energy Analyzer, but nah. 13-Jun-20 09:08 AM ok 13-Jun-20 01:13 PM Joined the server. 18-Jun-20 10:06 AM just got back to the lab, after being out since march 18-Jun-20 10:06 AM the high vacuum chambers I closed with "vintage" KF valves only and shut off were still 0.1 torr! nice 18-Jun-20 10:56 AM It was very satisfying to hear the hiss when I opened up my chamber for the first time in a few months too. Don't know what the pressure is inside exactly though 18-Jun-20 11:45 AM you get the hiss even at like 600 torr, if your valve opens slowly and your volume is big 19-Jun-20 08:04 AM hmm 19-Jun-20 08:04 AM I'm pumping down my big chamber to do some leak testing and it's behaving a bit weird 19-Jun-20 08:04 AM it went down to 0.1 mbar and then back up to 0.45 19-Jun-20 08:04 AM I'll let it pump down over night and then throw it on the leaktester 19-Jun-20 08:23 AM now it's at 8e-2 19-Jun-20 10:03 AM I just turned on the leak tester, time to get my Workshop up to temperature 19-Jun-20 10:03 AM I hate the oildiff :D 19-Jun-20 10:07 AM This is why I use Welch pumps. No funny business. They can run literally years straight with no issues. 19-Jun-20 10:17 AM well the welch is a forepump 19-Jun-20 10:17 AM that still needs an oildiff or turbo 19-Jun-20 10:17 AM and there is no funny Business with the oildiff, it just puts out a lot of heat 19-Jun-20 11:53 AM hene alignment fun 19-Jun-20 11:53 AM cantilevered arm off the optical table holding the final mirror, then it goes through a viewport, through the TOF electrode region, through a 2mm beam skimmer, through a gate valve window, through another skimmer, through another valve, through another skimmer, to a copper nozzle 19-Jun-20 11:53 AM everything is xy adjustable except the TOF 19-Jun-20 12:20 PM @GigaSquirrel What vacuum gauge are you using? If it is combined fullrange, they tend to jump sometimes when switching from pirani to penning/BA... 19-Jun-20 12:21 PM one combined, one pure pirani 19-Jun-20 12:21 PM they agree pretty well 19-Jun-20 12:21 PM the pressure jumps up when I get ipa on some places, I just always thought the pressure would drop in that case? 19-Jun-20 12:23 PM It usually goes bit up (as IPA leaks in) and then drops down as it freezes... 19-Jun-20 12:23 PM it goes up, that's it 19-Jun-20 12:23 PM falls after some time but not below the value before 19-Jun-20 12:23 PM leak might just be a bit too big for the pumps I have 19-Jun-20 12:23 PM bottoms out at ~7e-2 with the 22l/s leak tester and about a meter of kf16 tube 19-Jun-20 12:23 PM not ideal, I know 19-Jun-20 12:23 PM but the chamber is on my table and the leak tester is on the floor 19-Jun-20 12:23 PM just filled its cryo trap with (my last ) ln2, hopefully that will get it down low enough I can start up the filament 19-Jun-20 01:16 PM half a can of break cleaner later and I have localized 2 leaks 19-Jun-20 01:17 PM Must smell real nice in your room 19-Jun-20 01:17 PM I actually love the smell of brake cleaner 19-Jun-20 01:22 PM yeah it does 19-Jun-20 01:31 PM does anyone here not use plate nuts for CF flanges? 19-Jun-20 01:32 PM I don't 19-Jun-20 01:32 PM you should re-evaluate your life choices 19-Jun-20 01:32 PM I design my chamber so I have space to place wrenches 19-Jun-20 01:33 PM that's not all they're for though 19-Jun-20 01:33 PM I don't 19-Jun-20 01:33 PM what are they good for? 19-Jun-20 01:34 PM to open chambers, all you have to do is loosen a tiny bit and then spin the bolt head freely 19-Jun-20 01:34 PM normally you need a second finger or something to stop a nut from spinning 19-Jun-20 01:34 PM ah 19-Jun-20 01:34 PM They speed up the whole process a ton 19-Jun-20 01:34 PM well 19-Jun-20 01:34 PM I've got ISO and KF for that 19-Jun-20 01:35 PM Even in a case where you have to use threaded rod and a nut on each side, you can use a plate nut and a nut locked together to make them self-lock 19-Jun-20 01:35 PM @idmb If you want to be even faster, have threaded holes in flanges 19-Jun-20 01:35 PM I don't have extra money to spend on fancy hardware 19-Jun-20 01:35 PM And I don't take things apart very often 19-Jun-20 01:36 PM they're kinda pricey yes. 19-Jun-20 01:36 PM Threaded flanges are OK but you can't mount gate valves etc. to them 19-Jun-20 01:37 PM That is true... 19-Jun-20 01:37 PM They are easier to strip as well, so you'll need anti-seize as well 19-Jun-20 01:38 PM You should use that whenever you're baking anyways 19-Jun-20 01:39 PM Just put some big nuts on But good point on baking, didn't think about that 19-Jun-20 01:39 PM the only two times I've had to hacksaw were from baking 19-Jun-20 01:39 PM 2.75" flange plate nuts are awesome though. So much less finnicky. 19-Jun-20 01:39 PM 4.5"/6" not so necessary.... 8" and 10" are really nice though 19-Jun-20 01:39 PM wait I mean 3.375" and 4.5". 6" is nice 19-Jun-20 01:42 PM I think the biggest improvement in efficiency you can get when working with hardware on flanges is an impact driver. 19-Jun-20 01:42 PM oh and 1.33" if you use that 19-Jun-20 01:42 PM have one lol 19-Jun-20 01:42 PM I need one 19-Jun-20 01:42 PM Often times can't use it and don't want some weird angle adjustment for it 19-Jun-20 01:42 PM I might just hate dropping the occasional nut more than you all 19-Jun-20 01:42 PM but it happens at minimum half as often with plate nuts 19-Jun-20 01:42 PM I think we spent $600-800 on them last year, but we have a huge supply now and have kit out most flanges with them 19-Jun-20 02:55 PM Yes diffusion pumps are far more pleasant to be around in the winter! That’s why I use little 2” ones whenever I can and I wrap them with ceramic wool so I can lower the heater voltage after they come to temperature. 19-Jun-20 03:00 PM Oh god, before our lab didnt have independent AC from the rest of the building, and we have like 6 big old diffusion pumps in there. It regularly got to triple digits in the winter. It sucked. 19-Jun-20 04:01 PM We have a portable sink-cooled fan coil 19-Jun-20 04:01 PM For when hvac breaks 19-Jun-20 06:14 PM Oo, purely coax feeds! Still almost certainly a Quadrupole Mass Analyzer. I'm guessing there's four of these screw hole collumns around the device? I'd probably also guess those four metallic blocks on top are connected straight down to the fed-through rods below all around, possibly the middle feedthrough on both sides are for the filament. Bottom case almost certainly holds a faraday cup and maybe a few dynode stages. > You should be able to remove both the cylindrical and rectangular casings to see the Inside quad rods. > If the case was bulging and had far more room it could have been a Cylindrical Mirror Electron Energy Analyzer, but nah. @hanstj It turns out it is indeed a QMA! Made by UTI, apparently. There's a third box I'm missing, unfortunately, but I do have what looks like an LC network for this thing. 19-Jun-20 06:14 PM It's a UTI Model 100C 19-Jun-20 09:05 PM Sweet! Planning on getting one of the drivers on eBay? Not that pricy and probably real easy to hack into with a small daq board. Would be pretty decent for rga use 19-Jun-20 11:59 PM I've never worked with one before. What kinds of drivers are there? Do you have any literature for working with one? 20-Jun-20 12:17 AM Mkay, actually a video gave the basic theory. I'd love to find some manuals or sevice manuals to find out what might be going on inside this thing, though. Not sure what the purpose of the outer grids and filament are, and I've not worked with a set of dynode stages yet. 20-Jun-20 12:17 AM If it's RF, and high voltage, I feel doubtful that it's working at industry standard 50 ohms. 20-Jun-20 11:33 AM so i replaced the LVO210 oil with LVO100 in Trivac but I just emptied it normally...the new LVO100 got super foamy. is there a good way to remove and clean it out without having to fully disassemble and clean? 20-Jun-20 12:05 PM Isn't the foam just from dissolved gas? 20-Jun-20 12:05 PM I mean, wait for it to dissipate, then try again? 20-Jun-20 12:08 PM hmm it's fresh oil though, i heard multiple oils mixing might cause that? should i open gas ballast and wait a bit? i've run it for almost an hour now with gas ballast closed. it started up and quickly was at 1torr but has been steadily moving up, now at 31torr 20-Jun-20 12:29 PM 31 torr with power off? 20-Jun-20 12:50 PM My SEM is gone. 20-Jun-20 12:50 PM I think it went to a good home. Former Intel guy playing around with fs lasers. 20-Jun-20 12:52 PM whaaat 20-Jun-20 12:54 PM living without a SEM is possible but pointless 20-Jun-20 12:55 PM I sold it for like double the price I paid.... 20-Jun-20 12:55 PM you had no application? 20-Jun-20 12:58 PM Too many other projects keeping me busy. I wasn't using the SEM enough to justify keeping it. 20-Jun-20 12:58 PM Plus I could tell that if I was going to seriously use the SEM, I'd want a full size machine anyways, and not the desktop size machine that I had. 20-Jun-20 01:00 PM Ah ok it was a tabletop sem 20-Jun-20 01:18 PM @nmz787 no while it was running, i started it up and immediately got down to 1torr, but after almost an hour of running it just kept going up to 31 torr and continued 20-Jun-20 01:18 PM @piGuy what's the size of something like that? is it just that it can view smaller objects or is the resolution not as good as larger ones? 20-Jun-20 01:22 PM @samy the stated resolution of the SEM was 25nm. The sample chamber was smaller than a normal sized one. No EDS on the machine either. But it was small and cheap and only 150lbs. 21-Jun-20 02:27 PM Joined the server. 21-Jun-20 02:32 PM Strife 21-Jun-20 06:25 PM Joined the server. 22-Jun-20 05:15 AM hey guys, id appreciate if anyone familiar with UHV bakeout could help me here. im trying to bake a glass cell (not shown here, but stationed above the 6-way) and the associated peripheries. there are some low max temperature stuff (gauges/ionpump max 150C) in yellow, the turbopump in green (max 120C), and the gate valve (max 150C) in pink, whereas the steel tubes can be heated to 450C. how can i get the fastest bakeout of this apparatus? one issue was i'm not sure how to deal with the temperature gradients. while the steel's fine and comprises of most of the chamber, heating them to high temperature means my components like the gate valve will be damaged. the other issue is, i approached a heating company intending to buy heat tapes, but they told me heat tapes shouldnt be used for cross-pieces because the wrapping overlap may cause overheating. i wasn't quite convinced - shouldn't there be a way to wrap that avoids that problem? i'm also not sure how many controllers do i actually need, or is getting a relay with a tunable duty cycle and measuring the temperature manually the best approach? 22-Jun-20 05:15 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-050FB.png 22-Jun-20 05:15 AM ive never worked with UHV before, so the bakeout is a very new process to me! 22-Jun-20 05:23 AM @vapicuno I have just one comment - be careful about radiation. I wouldn't heat that 4-way cross to 450C, because it can easilly radiate to TMP and overheat the rotors... 22-Jun-20 05:24 AM i see. i thought it would more happen through conduction, but thanks for the tip. i definitely thought working at a lower temperature of maybe 250C or so would be appropriate, but i dont know for sure. 22-Jun-20 05:24 AM just fyi, each of the red components there are 125mm long, and i calculated the heat decay length to be a few cm assuming a air heat transfer coefficient of 10 W/m2K 22-Jun-20 05:24 AM but i dont know how good these calculations are in a real application (im doing this in a typical lab, so presumably the air is a bit more still than id like) 22-Jun-20 09:16 AM Joined the server. 22-Jun-20 09:27 AM Just realized that metric vacuum + optics folks don't have to deal with two thread sizes on their bolts 22-Jun-20 09:27 AM 1/4-20 and 1/4-28 for WHO KNOWS WHAT REASON 22-Jun-20 10:50 AM I've never worked with one before. What kinds of drivers are there? Do you have any literature for working with one? @Laughing Since this system is so old and analog you won't find drivers. Someone has probably made a generic labview vi, but that'd be the closest you'd come to a driver. You may get a m/z sweep and log current output, maybe a gain set, mass width and a few enable inputs, possibly also an ext. Sweep input. If not, all the above are easily hackable. X-Y plot on a scope may be enough, but this should be easy to set up with an arduino. Don't have much in the way of litterature sadly, but quads are pretty simple systems really. Just google about a bit. 22-Jun-20 11:04 AM @vapicuno a bake need not be high temperature, you can just as well heat to lower temperatures and just wait longer. 22-Jun-20 04:04 PM I put one of my in-vacuum x-y adjusters in place without having run bolts through the threads a few dozen times from the machine shop 22-Jun-20 04:04 PM UGH these are so hard to turn even with no resistance 22-Jun-20 06:16 PM <𝓕ermion#6024> the ethernet drivers were broken on this tektronix timing generator I bought... couldn't get it to recognize any mass storage devices over USB sadly 22-Jun-20 06:16 PM <𝓕ermion#6024> ripped the hard drive out, put the ethernet drivers on it, worked like a charm 22-Jun-20 09:18 PM doesn't it take floppies? 23-Jun-20 02:42 AM Has anyone diyed a DC power supply for sputtering applications with a magnetron? I was thinking about using a variac and microwave oven transformer, but I am concerned with safety and how the output waveform should look like 23-Jun-20 02:44 AM @Nixie did sputtering with a mot, as well as many others 23-Jun-20 06:41 AM Yes, no trouble whatsoever in getting it working: 23-Jun-20 06:41 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/whatsapp-image-2018-03-27-at-15-30-329-FA00B.png 23-Jun-20 06:41 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/whatsapp-image-2018-03-28-at-16-04-183-e15-B4796.png 23-Jun-20 06:41 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/sputertrhon-92A21.png 23-Jun-20 06:41 AM High voltage divider to read Vout: 23-Jun-20 06:41 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/img-20180501-wa0000-e1525180927299-13B73.png 23-Jun-20 06:41 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/img-20180514-wa0007-B626C.png 23-Jun-20 06:41 AM Center: copper oxide that forms with residual Oxigen and whatnot on the chamber 23-Jun-20 06:46 AM This looks cool 23-Jun-20 06:46 AM What is it 23-Jun-20 06:46 AM Left: a few days old Copper on glass and soldering test. 23-Jun-20 06:46 AM Right: recent copper on glass. 23-Jun-20 06:46 AM It's the power supply for a plasma machine that puts metal on things inside a vacuum chamber 23-Jun-20 06:46 AM @Epilogis they usually say that the best material to test your setup is silver (if you can get your hands on a small sheet of that) as it does not oxidize, and will work with dirty plasma. To do copper and aluminium, you definitely need Argon atmosphere. (or cover your pieces very well, until all oxygen is depleted. 23-Jun-20 07:05 AM @Nixie thanks so much for your explanations ! I may have understood that wrong but I have seen that adding a capacitor as the output of the diode bridge in conjonction with the plasma setup would act like a spark gap where the capacitor would charge and when the threshold is reached discharge rapidly, creating more of a pulsed dc, so I wasn't quite sure if it was needed 23-Jun-20 07:16 AM That might happen if you used straight AC (NOT sure about that), but using a rectifying bridge turns that into DC, and adding a capacitor just smooths out the leftover pulsing (to an extent) 23-Jun-20 07:16 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/power-supply-capacitor-smoothing-01-56D6B.png 23-Jun-20 07:26 AM Ok I may have misunderstood, let me find back where I have seen that information 23-Jun-20 07:26 AM It's in this video : https://youtu.be/zcpDGKH9_SE he talks about capacitors in a vacuum tube at around 16:20 (I assumed it was the same in a vacuum chamber with a magnetron) after seeing that I was a bit confused whether I should add a capacitor to my system, let me know what you think 23-Jun-20 08:18 AM well the magnets alter the discharge characteristic a lot 23-Jun-20 08:18 AM I had to repair a commercial sputter coater. 23-Jun-20 08:18 AM Had schematics for it somewhere. 23-Jun-20 08:18 AM But I seem to recall it was really simple. Big transformer. Bridge rectifier. Caps. 23-Jun-20 08:18 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-BD8D1.jpg 23-Jun-20 08:51 AM Those are the best tools, simple and functional! 23-Jun-20 09:59 AM Ok interesting, thanks for the help ! 23-Jun-20 02:20 PM worth mentioning that microwave oven transformers are brutal and unforgiving old-testament gods that can source enough current to absolutely gruesomely maim and/or kill you dead, so, like, be careful 23-Jun-20 02:21 PM Add in a capacitor to make it extra interesting... 23-Jun-20 02:21 PM but i've also done clumsy magnetron+MOT+diode rectifier+microwave cap filter sputtering, it's a good power supply for that 23-Jun-20 02:21 PM everyone loves surprise kilovolts ^^ 23-Jun-20 02:22 PM I miss my 3KVA 120KV bridge rectifier 23-Jun-20 02:22 PM If anyone has some spare lead rolls I might finish my x-ray machine 23-Jun-20 02:23 PM huh semiconductor? or something vacuum tube-y? 23-Jun-20 02:23 PM Semiconductor 23-Jun-20 02:23 PM impressive, 120kV seems way up there for solid state hardware 23-Jun-20 02:24 PM nah, just 20 12kv diodes per leg 23-Jun-20 02:24 PM Made one x-ray and called it a day 23-Jun-20 02:25 PM :D 23-Jun-20 02:25 PM When the geiger indicator is saturated... you stop playing hahaha 23-Jun-20 02:27 PM i've only ever made x-rays once from cold cathode field emission bremsstrahlung in high vacuum, that was my 'okay time to start buying lead if i wanna keep doing anything with this' cue 23-Jun-20 02:27 PM lead is cheap, shipping it is not 23-Jun-20 02:29 PM true.. i feel only slightly bad for amazon prime-ing a 12"x48"x1/16” roll to my doorstep 23-Jun-20 02:30 PM You'll never hear them coming... just a loud thud 23-Jun-20 02:30 PM but the two 175lb-each scintillator background shields involved a spritely trip across the bay area for my own pickup enjoyment >.> 23-Jun-20 02:31 PM I hope you had wheels of any type 23-Jun-20 02:51 PM How’d you find those 23-Jun-20 06:24 PM Panning down a gun range could give you a lot of lead really fast (even when noone is shooting) 23-Jun-20 06:25 PM Not everyone is willing to be melting lead and casting bricks themselves though 23-Jun-20 06:25 PM Lead sheets/plates are much easier to handle 23-Jun-20 07:30 PM Yeah I've looked into dry panning but it's not super practical where I am 23-Jun-20 09:02 PM I really want lead for my HPGe. 23-Jun-20 09:02 PM A friend acquired a pair of microfocus x-ray cabinets. These are professionally shielded, have interlocks, etc. He already has gone through the state licensing process for a handheld XRF and is going to do the same thing for these. 23-Jun-20 10:23 PM Do you have advices concerning safety while using a mot? I am using an inductive ballast to limit current spikes, fuse, proper grounding, discharge resistor for the caps, is there something else? 24-Jun-20 01:51 AM if you can go with a grounded enclosure and float the xforme and isolate the HV with standoffs you should be good. As for the actual HV output.... Proper HV cables and connectors, interlocks, discharge resistors, deadman switch... 24-Jun-20 01:51 AM in short, good grounding, distance, and a Hold to Operate switch far away from the device. Power indicators (sound or light) are very good too 24-Jun-20 02:37 AM i got my lead from local uni (Berkeley) surplus, one came with a cute little DS-11 PMT base and some shimming acrylic.. some 93Ω coax, etc. nice little assemblies, ostensibly 'low background' but i haven't meaningfully measured that yet 24-Jun-20 02:37 AM hold to operate isn't necessarily reasonable with, like, a sputtering system, where it's liable to be running continuously for many minutes (but also don't leave it unattended). just enclose all the HV bits (i tucked my MOT setup inside my bell jar shield; not in vacuum but enclosed nonetheless) ground everything you can safely (one side of the secondary of a MOT will be tied to its ground, by default; factor this into your circuit design), be mindful of any ground loops with any HV-side voltage/current measurements you may do. strive to not ever touch or come near anything on the HV side while it's running 24-Jun-20 09:53 AM Joined the server. 24-Jun-20 09:57 AM Sounds good, I'll try to add most of those methods in my system ! Thanks. What's a DS-11 PMT ? I've tried to look that up, only found things about a new testament something something, guess it's unrelated 24-Jun-20 09:58 AM what are people's Trivac D2.5E's generally pulling pressure down to? 24-Jun-20 02:54 PM Joined the server. 24-Jun-20 02:54 PM Joined the server. 24-Jun-20 02:54 PM Double touch down 24-Jun-20 02:54 PM Friends, I have arrived 24-Jun-20 02:55 PM what are people's Trivac D2.5E's generally pulling pressure down to? @samy 1e-2 reliably 24-Jun-20 02:55 PM hwllo new people! 24-Jun-20 02:55 PM Where do I look for spare glassware 24-Jun-20 02:56 PM Anyone in here build an aluminum pvd setup? 24-Jun-20 02:56 PM I was just asked to build a 18" x 24" system that doesn't need too much finesse in the applied thickness, though it should be pretty even (so I think there'd need to be some rotation of the substrate to even things out). 24-Jun-20 02:56 PM @GigaSquirrel how's your progress on that? 24-Jun-20 02:56 PM Is that what you were talking about boats or baskets for recently? 24-Jun-20 03:00 PM aye, but I did not test it under vacuum yet 24-Jun-20 03:00 PM in air it gets plenty hot 24-Jun-20 03:00 PM What power supply? 24-Jun-20 03:01 PM self wound toroid transformer 24-Jun-20 03:01 PM never actually measured current or voltage, but I'd guesstimate it's like 20V at 100A 24-Jun-20 03:03 PM Hmm, does tHe voltage and current matter, or just the power? 24-Jun-20 03:03 PM I.e. could I use a MOT instead? 24-Jun-20 03:03 PM Variac then MOT 24-Jun-20 03:04 PM power is important 24-Jun-20 03:04 PM Or like, why not just straight wall AC with a variac 24-Jun-20 03:04 PM Just safety reasons? 24-Jun-20 03:04 PM current reasons 24-Jun-20 03:04 PM if you have a boat or basket with the right resistance it should work just fine on wall power 24-Jun-20 03:04 PM but a boat has to have a certain size to be able to put someting you want to evap on it 24-Jun-20 03:06 PM Hmm, ever hear about just powering aluminum wire directly? 24-Jun-20 03:06 PM Like if you have it resting on some ceramic floor or something non conductive? 24-Jun-20 03:06 PM Ceramic channel 24-Jun-20 03:07 PM well Al is a pretty good conductor, so you'd need a lot of current to get some heating power 24-Jun-20 03:07 PM and manufacturing channels like that can be hard 24-Jun-20 03:08 PM Didn't @Nixie machine firebrick pretty easily? 24-Jun-20 03:08 PM I see some thin gauge aluminum online for pretty cheap 24-Jun-20 03:09 PM but firebrick is far from vacuum compatible 24-Jun-20 03:09 PM Long pump down is ok 24-Jun-20 03:09 PM question is 24-Jun-20 03:09 PM why not go with boats or baskets 24-Jun-20 03:09 PM what would be the downside 24-Jun-20 03:10 PM Hmm, just thinking if I could slink a wire back and forth, to help with evenness of evap 24-Jun-20 03:10 PM But in general, I guess just less parts 24-Jun-20 03:10 PM Maybe not worth it 24-Jun-20 03:10 PM Just started thinking of this 24-Jun-20 03:11 PM well a slink of wire will melt, drop down and break the circuit 24-Jun-20 03:12 PM Yeah the channel would need machined very evenly 24-Jun-20 03:12 PM So it would still be a molten wire 24-Jun-20 03:13 PM so you're making a boat out of some non vacuum compatible metal 24-Jun-20 03:13 PM Hehe 24-Jun-20 03:13 PM Well non-conductive boat 24-Jun-20 03:13 PM Are boats cheap? 24-Jun-20 03:13 PM Tungsten? 24-Jun-20 03:15 PM W, Mo or Ta 24-Jun-20 03:15 PM they're cheap ish on aliexpress 24-Jun-20 03:34 PM 6" x 6" tungsten sheet is like $120 24-Jun-20 03:34 PM Seems like I could cut strips of that and bend into a V shape? 24-Jun-20 03:34 PM Idk how hard tungsten is to work with 24-Jun-20 03:37 PM absolute pita 24-Jun-20 03:37 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200604_142656-C9AA7.jpg 24-Jun-20 03:37 PM .1 mm W sheet and shears 24-Jun-20 04:09 PM Huh. The helium lines for the new cold head are much nicer than the vintage one 24-Jun-20 04:09 PM I hadn't realized how much more flexible they were. 24-Jun-20 04:09 PM minimum bend is still 7" radius, but they so wiggly 24-Jun-20 04:15 PM thats really nice... most helium lines I have can only do like... 18" if your rough with it lol 24-Jun-20 04:58 PM they came coiled and when I opened them they sprang out a little 24-Jun-20 04:58 PM but then just unroll them and they go straight immediately with no resistance 24-Jun-20 07:46 PM You have to use a lapidary saw on tungsten. 24-Jun-20 07:46 PM We special ordered some 4” .030 thick super fine grain cutting wheels. Carborundum. The resin bond glass cutting wheels do work but they wear out fast on tungsten. 24-Jun-20 09:34 PM @nmz787 depending on your goal, my simplest setup is a tungsten wire between to spark plug feedthroughs, and then I just rest some aluminum foil on the filament 24-Jun-20 09:34 PM Here is a result from the last time I did that 24-Jun-20 09:34 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200518_120459-2B4DE.jpg 24-Jun-20 10:03 PM Joined the server. 24-Jun-20 10:22 PM @GigaSquirrel dang, ok well that idea might be out then 24-Jun-20 10:22 PM @Charles hmm, ok, so basically a grinding wheel, possibly in a wet saw. That's do-able. But I wonder about using something like a metal brake to bend a sheet into an L shape. Sounds questionable 24-Jun-20 10:22 PM @ericdalgetty hmm, that's pretty interesting. I could see myself stringing a bunch of wire back and forth and laying a sheet on top. The "reaction" might not last long (if the foil melts then droops and falls onto the chamber floor) but that could be OK if it coats with enough thickness before that happens 24-Jun-20 10:22 PM (by sheet I mean, sheet of aluminum foil) 24-Jun-20 10:35 PM hi is there somewhere something like some rocket tec discord? 25-Jun-20 01:24 AM @GigaSquirrel dang, ok well that idea might be out then @nmz787 But Mo foil is cheap on ebay 25-Jun-20 01:24 AM hold on 25-Jun-20 01:24 AM https://www.ebay.de/itm//181580152548 25-Jun-20 09:44 AM Gotta love when our detection chamber pumps down an order of magnitude slower than the differential pumping chamber before it that doesn't really matter 25-Jun-20 10:13 AM En regard to bending thin tungsten sheet or foil in a brake it is possible but only after annealing and it is berry tricky even then. 25-Jun-20 02:56 PM I completely forgeet about this channel as I idle more in the off-topic, heh 25-Jun-20 06:10 PM @Noxz I let no messages go unread on this server... Generally I just scroll quickly in the radiation channel tho since it's the one I care least about 25-Jun-20 06:11 PM there are certain topics that are beeyond me.. also I am in a handful other servers with too many channels, so it's a habbit to not really care about it all 25-Jun-20 06:19 PM Heh, I mostly don't care about any of the other servers, this one seems the most serious 25-Jun-20 06:28 PM @GigaSquirrel ooo yeah similar pricing in US eBay 25-Jun-20 06:31 PM heh, I'm kind of an admin on a chem server that kinda bit the dust recently.. I view stuff in there a few times a month 26-Jun-20 03:43 PM has anyone here worked with bridgman furnaces before? 26-Jun-20 03:43 PM they seem deceptively simple 26-Jun-20 03:50 PM I have been wanting to build one and that was my impression as well... Seems almost too simple but I have also seen the furnaces depicted in a couple papers and they weren't anything special 26-Jun-20 03:50 PM I've decided to build one 26-Jun-20 03:50 PM The hard part seems to be the raising/lowering mechanism and if you decide to move the heating elements or the sample container 26-Jun-20 03:50 PM The pandemic sapped my funds for that sort of project 26-Jun-20 03:50 PM Had a couple quotes for quatrz tubes and everything then basically everything shut down 26-Jun-20 03:50 PM You are planning to try growing scintillators I am assuming? 26-Jun-20 03:52 PM perhaps 26-Jun-20 03:52 PM Only real thing I was trying to resolve was making CeBr3 26-Jun-20 03:52 PM all the high rez stuff is like >2k for a 1x1" crystal 26-Jun-20 03:52 PM I decided to go with LaCl3 26-Jun-20 03:52 PM maybe Ce doped? 26-Jun-20 03:53 PM Needed to find someone more well versed in chemistry than I am to resolve the reasons behind literature saying not to just use regular cerium oxide 26-Jun-20 03:53 PM I did not find anything conclusive on what the doping (or its concentration) does 26-Jun-20 03:53 PM oxides stop the scintillating process from what I found 26-Jun-20 03:53 PM Oh I was talking about using that for the production of the tribromide 26-Jun-20 03:53 PM oh 26-Jun-20 03:53 PM that should work 26-Jun-20 03:53 PM heat it with ammonium bromide and you should get CeBr3 26-Jun-20 03:54 PM There was a weird note saying not to use certain oxidation states for that in the paper I was referencing 26-Jun-20 03:54 PM But only with cerium 26-Jun-20 03:54 PM at least that's how a few papers did it for halogenides of La 26-Jun-20 03:54 PM oh, then I don't know 26-Jun-20 03:55 PM So I wanted to talk to someone and find out WHY that is before I started buying the raw materials and tooling 26-Jun-20 03:55 PM The La side of things seems deceptively simple as well but inert atmosphere stuff rarely really is in the end. Some impressive results in the papers I have seen though. 26-Jun-20 03:56 PM yeah the atmosphere part is an issue, but if I do everything right I should be able to just pump my crucible while it's in the oven 26-Jun-20 03:56 PM but I also found a paper that said you can do it under air, as long as you throw some carbon in there before sealing up 26-Jun-20 03:58 PM Interesting idea. Something I have seen used in metalworking but not really scintillator growing 26-Jun-20 03:58 PM if I may ask, why CeBr3? 26-Jun-20 03:59 PM Just to dope the LaBr3 26-Jun-20 03:59 PM ah, right 26-Jun-20 03:59 PM CeBr3 works as a scintillator as well, and has way less intrinsic background than La salts 26-Jun-20 04:00 PM That was part of why I wanted to figure out what kind of cerium oxiation state is really needed for the bromination 26-Jun-20 04:00 PM I just bought some 3n CeBr3 from onyxmet, I hope it will be clean enough 26-Jun-20 04:01 PM My plan was LaBr3(Ce) first because it is a pretty well documented scintillator on the growing conditions side of things and then trying other stuff 26-Jun-20 04:01 PM How are you planning to try controlling the orientation of the crystal growth? 26-Jun-20 04:01 PM not at all 26-Jun-20 04:01 PM doesn't matter for scintillators 26-Jun-20 04:01 PM also I think it's (close to?) impossible with bridgman 26-Jun-20 04:02 PM Some are much harder to work with in some orientations though... Let me try to find the paper I was reading 26-Jun-20 04:02 PM They had an interesting idea with some custom quartz tubes that controlled the orientation 26-Jun-20 04:04 PM honestly, before I think about working with the crystals I'd be happy to get one at all 26-Jun-20 04:04 PM https://sci-hub.tw/10.1021/cg100557e 26-Jun-20 04:04 PM the crucibles might also be an issue, I have not found the proper ones and test tubes might not be steep enough at the bottom 26-Jun-20 04:04 PM oh, interesting 26-Jun-20 04:04 PM 1 mm/h almost seems a bit high from what I found 26-Jun-20 04:04 PM I ordered some fire brick, PID controllers and heaters today, we'll see in a few weeks where this project goes 26-Jun-20 04:09 PM I was just impressed by this and it was a lot better results than other papers: "By controlling the velocity at the initial stage of the LaBr3:Ce crystal growth and the quartz ampule shape, the [001]oriented single crystal can be achieved when the LaBr3:Ce crystal grown by the self-seeding Bridgman technique. This makes the self-seeding technique an effective method to grow the large size LaBr3:Ce single crystal. The [38 mm diameter x 50 mm] LaBr3:Ce single crystal ingot has been achieved by it." 26-Jun-20 04:11 PM I'm aiming for 20x20 26-Jun-20 04:11 PM optimisation will follow when (if) I get a working crystal 26-Jun-20 04:12 PM Yeah I was planning a smaller scale test before going for anything crazy like 38mm diameters 26-Jun-20 04:13 PM 20x20 LaBr3 costs ~750 from the chinese, my goal is to make one for less 26-Jun-20 04:13 PM and <5% FWHM @ 662 keV 26-Jun-20 04:13 PM also for your LaBr3 you might try adding a bit of Cl, that seems to improve mechanical stability 26-Jun-20 04:13 PM https://scionix.nl/high-resolution-lbc-scintillators/ 26-Jun-20 04:16 PM I don't remember the exact numbers I was working out but I figured I could make a 25mm cube/35mm diameter crystal 50mm long for around $150 in raw materials or so (including the probably single use quartz tube)... 26-Jun-20 04:16 PM where do you get your chemicals that cheap 26-Jun-20 04:16 PM things may have changed since prices on stuff are all over in the USA right now 26-Jun-20 04:16 PM but bromine sources are super cheap for some reason 26-Jun-20 04:16 PM the La from China... 26-Jun-20 04:16 PM that number does not include the tooling/glassware/etc necessary to do all the production processes either 26-Jun-20 04:16 PM just the raw materials for one run 26-Jun-20 04:19 PM but still, I paid 35 bucks for 100g LaCl3 heptahydrate 4n, that's about 13 ml of pure LaCl3 26-Jun-20 04:19 PM I remember the bromide being a bit more expensive 26-Jun-20 04:19 PM thats why I was looking into making the LaBr3 and CeBr3 myself 26-Jun-20 04:19 PM minus losses in the crucible, such as the cone etc 26-Jun-20 04:19 PM ohh you meant you literally ordered lanthanum metal 26-Jun-20 04:20 PM no I never ended up ordering anything because of the pandemic haha 26-Jun-20 04:20 PM I don't trust my chemistry enough to get a pure result 26-Jun-20 04:20 PM and according to what I read 4n is enough 26-Jun-20 04:20 PM so I'm going with what I can get 26-Jun-20 04:21 PM I am fairly comfortable with chemistry stuff but this would definitely stretch my abilities pretty far 26-Jun-20 04:21 PM is LaCl3 less hygroscopic than the tribromides? 26-Jun-20 04:22 PM not that I know of 26-Jun-20 04:23 PM well that is fun 26-Jun-20 04:23 PM yep 26-Jun-20 04:23 PM friend's got a glovebox I can (ab)use for that 26-Jun-20 04:23 PM just fill it with nitrogen 26-Jun-20 04:23 PM a beaker of LN2 is pretty good at that, nitrogen displaces air and the cold freezes out all humidity 26-Jun-20 04:23 PM first test will be drying the powder and testing if it glows under x-rays 26-Jun-20 04:23 PM that should be interesting 26-Jun-20 04:23 PM then crystal growth and another x-ray test 26-Jun-20 04:23 PM before I even open up the crucible 26-Jun-20 04:27 PM Damn that’d be cool if it worked 26-Jun-20 04:27 PM oh yes 26-Jun-20 04:27 PM I am still looking for the thing that stops most people from doing that 26-Jun-20 04:27 PM like many unis have bridgmans 26-Jun-20 04:27 PM but most do NaI and CsI 26-Jun-20 04:28 PM Is it just a finicky process? 26-Jun-20 04:29 PM it kind of is 26-Jun-20 04:29 PM takes a looong time to dial in 'cause the growth time is in the order of days 26-Jun-20 04:38 PM but if it works I can safe a whole lot of money on ln2 for the hpge 26-Jun-20 04:38 PM I rarely ever need the resolution, but I want something better than NaI 26-Jun-20 04:38 PM https://www.ost-photonics.com/product-category/scintillation-crystal-2/labr3ce-scintillator/ Not sure if I posted that here already 26-Jun-20 05:16 PM Hmm, I wonder how that 2x1cm Crystal would work for general use 27-Jun-20 01:02 AM it should 27-Jun-20 01:02 AM up to like 1 MeV or so 27-Jun-20 01:22 AM nah, honestly a bit more, it's quite a bit denser than Nai 27-Jun-20 03:53 AM oh, but 27-Jun-20 03:53 AM I've learned that for the high rez scintis you want a sba or uba (super and ultra bialkali) pmt or you'll lose 0.5-1% 27-Jun-20 04:11 AM oh and also also LaBr3s resolution is actually worse than NaI below ~120 keV 27-Jun-20 04:11 AM which is a bit sad imo, considering that there's the interesting part of a spectrum containing the heavier stuff 27-Jun-20 10:52 AM that Bridgman oven looks interesting 27-Jun-20 10:52 AM I'd be interested in growing saphire and rubies for watches 27-Jun-20 10:52 AM I once looked into microwave oven methods 27-Jun-20 11:02 AM I think the Verneuil Method would be more Suited for those materials 27-Jun-20 11:02 AM you'll have a hard time finding a crucible for molten ruby 27-Jun-20 11:02 AM oh but the skull method might work 27-Jun-20 11:02 AM skull and halogen lamps in a mirror could just do it 27-Jun-20 01:45 PM looked some of those up, interesting 27-Jun-20 01:45 PM I havent researched any of this in a few years.. mostly because I can get boules of ruby for super cheap 27-Jun-20 01:48 PM well that's pretty cool 27-Jun-20 01:49 PM ruby and sapphire are about the only things I'd be interested in at htis point, too 27-Jun-20 01:49 PM highly interested in Langmuir films, still 27-Jun-20 01:49 PM but that's a completley different idea, of monolayer vs crystals 27-Jun-20 01:49 PM school starts up, on campus, on monday 27-Jun-20 01:49 PM trying to chill out (did house work all week long, also my frog tanks crashed down on me last night) and semi-prepare for it all 27-Jun-20 01:49 PM a buddy says it'll last a week before cases occur and they'll shut campus down again 27-Jun-20 01:49 PM I'm giving it at least 3 27-Jun-20 01:52 PM good luck either way 27-Jun-20 01:52 PM luck never hurt anyone 27-Jun-20 01:52 PM unless it was bad luck 27-Jun-20 01:53 PM hrm, maybe I wasnt explicit enough 27-Jun-20 01:54 PM ^^ 27-Jun-20 01:54 PM first, let's see if bridgman is doable at home 27-Jun-20 01:54 PM the possibility of growing scintillators at home is just... everything I've ever dreamed of 27-Jun-20 01:54 PM proportional detectors are doable at home, geiger müller less so imo 27-Jun-20 01:54 PM but properly spectroscopy detectors... 27-Jun-20 02:00 PM mass spec is still on my todo list 27-Jun-20 02:00 PM next to: rebuild the chem lab 27-Jun-20 02:01 PM yep, I also want mass spec here 27-Jun-20 02:01 PM I have a Quadropole and it's rf & preamp unit, still need to reverse engineer that one 27-Jun-20 02:02 PM yeah, a quad is the design I would pursue 27-Jun-20 02:02 PM the mass spec book I have shows some basic calculations on the design of it and the ion trap one 27-Jun-20 02:08 PM ion trap stuff seems hard to do at home unless you have the ability to properly machine an electropolish all the parts 27-Jun-20 02:08 PM next month I'll get to watch the complete servicing of an fticrms, that will be fun 27-Jun-20 02:08 PM I'll try to get as many pics as possible 27-Jun-20 02:12 PM watching some of these MTI videos on their Bridgman ovens.. looks pretty simple 27-Jun-20 02:13 PM got a link? I must have missed them 27-Jun-20 02:13 PM here's the one I am looking at right now: https://www.youtube.com/watch?v=5BJZn8m7xjk 27-Jun-20 02:13 PM they have a bunch of them 27-Jun-20 02:14 PM ah, right, I misread that as MIT 27-Jun-20 02:14 PM hah, I looked at their logo and read it as TMI 27-Jun-20 02:14 PM https://lib.dr.iastate.edu/cgi/viewcontent.cgi?article=1024&context=ameslab_isreports This is also pretty interesting 27-Jun-20 02:14 PM they really show how easy it is 27-Jun-20 02:14 PM the issue for crystal stuff is that is has to move like 100-500 µm/hr, taking the grow time to days 27-Jun-20 02:16 PM meh, 2 hrs for some ruby bearings for watches, not too bad 27-Jun-20 02:16 PM plus heating time, plus the time the cone takes to crystallize 27-Jun-20 02:16 PM from what I've seen it's only viable in the cm size range minimum 27-Jun-20 02:18 PM what is that cable wire/chain typically made of? 27-Jun-20 02:18 PM something that can handle the temp 27-Jun-20 02:18 PM oh, found it at the end, SS or inconel 27-Jun-20 02:18 PM for my stuff I'll use kanthal 27-Jun-20 02:18 PM We got an ICP-MS with a quad donated. 27-Jun-20 02:18 PM We have been able to strike a plasma, but we ran into trouble. Light elements in a calibration solution were detected, heavy ones weren’t. 27-Jun-20 02:18 PM I think it’s a,combination of geometry (torch wasn’t aligned with the cones), using a low flow nebulizer that wasn’t admitting enough of the solution, and we needed to go into factory mode to manually dial in the high peaks because the machine was too far out of calibration to find them automatically. 27-Jun-20 02:39 PM It is hoped that this investigation may be one of the first steps toward making the growing of single crystals more of a "science" and less o.f an "art". 27-Jun-20 02:39 PM I like that 27-Jun-20 02:42 PM yes 27-Jun-20 02:42 PM the paper is really well written 27-Jun-20 02:42 PM that's so much of independant watchmaking - it's scary 27-Jun-20 02:42 PM and they use a minimum amount of asbestos! 27-Jun-20 02:42 PM I'm just really not sure if bridgman is the right method for rubys 27-Jun-20 02:47 PM maybe not 27-Jun-20 02:47 PM just reading into random things I am linked, as it is the weekend 27-Jun-20 02:47 PM and raining outside 27-Jun-20 02:48 PM that's the spirit 27-Jun-20 02:48 PM I don't dismiss anything 27-Jun-20 02:48 PM so, actually, for someone over in the chem server, I took apart a hotplate.. learned a couple thing son the construction, I can pic dump a few t hings if wanted 27-Jun-20 02:48 PM basically nichrome/kanthal around a mica board 27-Jun-20 02:48 PM forgot I did this, like 3 weeks ago 27-Jun-20 02:48 PM it was good to look into it, pretty standard in the end 27-Jun-20 03:01 PM yeah most thermal stuff is pretty easy tbh 27-Jun-20 03:01 PM sensor placement and a good pid loop is important 27-Jun-20 03:30 PM electric arc furnace, yay or nay 27-Jun-20 03:30 PM the NOx make your bread taste terrible 27-Jun-20 03:30 PM I am nox 27-Jun-20 03:31 PM they seem like fun 27-Jun-20 03:31 PM also, do you know of the org-syn about smoking cigs while doing a reaction for the detection of cyanide? 27-Jun-20 03:32 PM never heard of it 27-Jun-20 03:32 PM but I don't smoke, so... ^^ 27-Jun-20 03:32 PM http://www.orgsyn.org/demo.aspx?prep=CV1P0314 .. read note 1 27-Jun-20 03:32 PM published in 1927 27-Jun-20 03:33 PM hahaha 27-Jun-20 03:33 PM one of my fav synth writeups 27-Jun-20 03:38 PM I haven't done much synthesis so far 27-Jun-20 03:38 PM trying to stay away from most chemistry, that takes up too much space 27-Jun-20 03:51 PM I'm kind of thinking of a hack of electric arc + Bridgman .. something like a graphite crucible electrode which is lowered through a graphite ring electrode (segmented, for maintaing a spark on all sides) 27-Jun-20 03:53 PM I am not sure if you can regulate an arc that tightly 27-Jun-20 03:53 PM like +/-5 kelvin 27-Jun-20 03:53 PM right, that's kinda why I went to the segmented idea 27-Jun-20 03:53 PM to keep all sides equal-ish 27-Jun-20 03:53 PM but even so 27-Jun-20 03:54 PM and you need two heated zones for bridgman, one slightly above melting Point, one slightly below 27-Jun-20 06:18 PM The graphite and silver heat sinks were used to provide a low resistance path for vertical transfer of heat and thus help establish a steep vertical temperature gradient. This should help maintain the desired planar crystal-melt interface and suppress the formation of new nuclei . .. so, I kind of understand this phrase - the heatsink is a big block at the bottom, thus able to divert/xfer heat to from the middle to there, and as such, the transition area has a sharp temperature difference, instead of hot spots that may form, which upon cooling would crystal out of plane, right? 28-Jun-20 01:04 AM That's how I interpreted it 28-Jun-20 09:16 AM nothing like a well-timed vacation, my detector chamber has only been going down ~1E-7 per 12 hours the past few days... 28-Jun-20 02:17 PM I wonder if I can adapt the peak-hold solenoid driver IC I've been using (for direct fuel injection) for an arc initiator circuit 28-Jun-20 02:17 PM or simply the idea of peak-hold driven by a standard uC 29-Jun-20 05:45 PM So what's the difference between these two iso100 flanges??? https://www.ebay.com/itm/SS304-ISO63-ISO80-ISO100-ISO160-Vacuum-Flange/193215774484?hash=item2cfc8ebf14:g:iKMAAOSwJItcmcZ3 29-Jun-20 05:45 PM One says 102mm and the other 108mm 29-Jun-20 06:59 PM They say inner welding diameter 29-Jun-20 06:59 PM So the flanges are the same and will mate together, but you use different tube OD for them 29-Jun-20 06:59 PM Same as the plethora of CF 2.75” tube sizes 29-Jun-20 08:00 PM Ah ok, the whole "inside welding" threw me off as bad translation 29-Jun-20 08:00 PM I was thinking "all vacuum welds should be inside the chamber" 30-Jun-20 12:38 AM So since I plan to weld to a plate, that shouldn't matter, right? 30-Jun-20 12:38 AM Or do I need a different flange then? 30-Jun-20 10:51 AM Target pressure? 30-Jun-20 10:51 AM IDK if you've done much reading on vacuum welding, to do the serious UHV stuff a LOT of design work goes into it. For rougher vacuum it really doesn't matter. 30-Jun-20 10:51 AM The design work is to make it simple to make a non-porous weld 30-Jun-20 01:20 PM Eventually I want to get good enough to hack my imaging platforms, SEM and FIB, so like 10-7 or 10-8 torr at best 30-Jun-20 01:20 PM Going better would be interesting, but not anywhere near an immediate target 30-Jun-20 05:26 PM Even that low you probably want to have the nicest/easiest weld you can do 30-Jun-20 05:26 PM (Low? high?) 30-Jun-20 05:26 PM How were you planning to do the plate weld? do you have a CAD file? 30-Jun-20 07:44 PM No CAD, just thinking I'd freehand some stuff 30-Jun-20 07:44 PM Practiced welding this afternoon and until just a few minutes ago 30-Jun-20 07:44 PM Welded a few sides of a cube with no filler 30-Jun-20 07:44 PM Not terrible 30-Jun-20 11:13 PM I think you’d normally use tube between a plate and a flange if you couldn’t just machine the flange into the plate 01-Jul-20 12:02 AM hmm, I was thinking something along the lines of: buy big piece of plate, plasma cut it down to roughly the size I need to cover a 10" pipe I've got, then plasma cut out a circle that's smaller than the flange, then slap the flange on and weld, then weld the plate to the pipe. 01-Jul-20 12:02 AM this however, fails to realize that I can't weld the plate to the pipe with an inside weld 01-Jul-20 12:02 AM but at the same time, this was meant to be an experiment, soooo, hmmm 01-Jul-20 12:02 AM maybe this calls for me to get an ISO250 flange to weld to the 10" pipe 01-Jul-20 12:02 AM then a iso250 to iso100 adapter that clamps/bolts together 01-Jul-20 04:50 PM So I've seen some folks around here have set up a patreon, are you actually providing content or is it also a thing to do to allow people to donate to a project they might think is worth something? 01-Jul-20 06:57 PM i've had people harangue me for a way to donate in the latter case before, and i know some folks do it either way. guess it's up to preference/audience/whatever thing you're working on 01-Jul-20 07:32 PM I think direct donations are quite a bit better if you're not delivering via the patreon medium though ? 02-Jul-20 01:29 AM So I've seen some folks around here have set up a patreon, are you actually providing content or is it also a thing to do to allow people to donate to a project they might think is worth something? @pbx/peterbjornx I provide content mainly on twitter, nothing patreon exclusive 02-Jul-20 01:29 AM I have decided for myself that I want all the information I produce to be free 02-Jul-20 07:10 AM They're not mutually exclusive - a lot of people use patreon for early access. 02-Jul-20 11:18 AM patreon's a nice format for recurring donations bc a lot of folks already use it, so lowered activation cost there 02-Jul-20 12:53 PM Huh, so this new cold head that does 4k in 60 minutes 02-Jul-20 12:53 PM luls and goes real slow then the last ten minutes is just super speedy 02-Jul-20 08:11 PM My cold head only does 1080p 03-Jul-20 11:34 AM can you guys live from the patreons moneys? 03-Jul-20 11:34 AM not even close 03-Jul-20 11:34 AM ok 03-Jul-20 11:35 AM I'm thinking that if I put more effort in it I might get up to like 100 bucks a month 03-Jul-20 11:35 AM Some people surely do but I mean, how often do you like spending 90% of your time making videos/content for people and 10% of your time actually working on stuff? 03-Jul-20 11:36 AM yep 03-Jul-20 11:36 AM That's the BIG problem. I have much respect for people who make it on youtube and patreon 03-Jul-20 11:36 AM I have gone through video editing classes and such and yea... 03-Jul-20 11:36 AM its way too much effort and time and well frankly just working on projects I burn myself out and end up in luls of no work or other stuff and just... yea... with patreon you have to constantly churn 03-Jul-20 11:36 AM or when you do finally post again people who forgot they started throwing you money might ask, hrm I guess they became less active, is it worth it to keep contributing? 03-Jul-20 11:36 AM its a massive undertaking to keep something like that going 03-Jul-20 02:27 PM Govt grants, the original patreon, but with expectation that you write-up your results instead of video edit them 03-Jul-20 02:27 PM I donate to like one or two patreons and don't really check up on the folks, no real expectations 03-Jul-20 03:18 PM I’m a bit upset at Patreon for them de-platforming a woman maker of color, Naomi Wu. 03-Jul-20 03:18 PM VICE Motherboard violated a written agreement with her, effectively outing her as queer by implication. So she subtly doxxed the editor. Patreon didn’t seem to understand the difference between punching down vs. up and presumably caved to VICE, never mind how critical that money was to her existence as an independent maker. 03-Jul-20 03:18 PM So... I’m pissed at Patreon. 03-Jul-20 03:24 PM I mean punching up or down is kinda irrelevant if both weren't allowed 03-Jul-20 03:25 PM Had they unlinked the content and warned her, or suspended her for a finite time, I’d have thought that reasonable, but what happened was unconscionable. 03-Jul-20 03:25 PM VICE isn’t exactly hurting for money, and neither is the editor. They suffered no consequences for what they did to her. She, on the other hand, essentially lost her livelihood. She had to quit making and go back to coding full time. She was only able to get back into making after finding a corporate sponsor, which effectively means she was forced to sell out. 03-Jul-20 03:25 PM This only happened because VICE reneged on a written agreement to keep certain areas of her life off limits in their story. They outed her for her sexual orientation. As a Chinese national, she doesn’t exactly have the wherewithal to sue a US media mega-corporation. She tried to de-escalate but they wouldn’t honor their agreement, hence she did what she did. 03-Jul-20 03:33 PM does patreon have any affiliation with VICE though? 03-Jul-20 03:35 PM Probably not, but the implication is that VICE lawyers pressured Patreon into this. 03-Jul-20 03:35 PM She still kept her YouTube channel and Twitter. But Patreon is where she was effectively making money. (There’s also allegations she was shadow-banned on Twitter and YouTube.) 03-Jul-20 04:37 PM I don't get how a magazine ot whatever they are, has anything to do with pressuring a donation service 03-Jul-20 04:37 PM Like, what sort of reasons could they have used, unless she was violating terms of service 03-Jul-20 04:42 PM well selectively enforcing / giving out different punishments for TOS violations is a thing 04-Jul-20 08:49 AM Exactly. Also, there were extenuating circumstances around the TOS violation; it could be considered a response to an even greater violation against her. Even in criminal law, it’s OK to punch someone if they’re trying to kill you. 04-Jul-20 08:49 AM As a PRC citizen who has gained a large internet following, that puts her under a government microscope. The PRC has no qualms about making people disappear. She had concerns about allowing VICE a lot of access to her in running their feature, so she got written agreements in advance. 04-Jul-20 08:49 AM After VICE came to the PRC, did the interview, and returned, their editor started acting as if those written agreements never existed, which put her in danger. 04-Jul-20 08:49 AM There’s also the context where 4chan arsewipes couldn’t believe a non-white woman could actually be a maker, and they circulated a slander that she had a western engineer husband who designed all her stuff, and she was just the actor performing it. 04-Jul-20 08:49 AM Dale Dougherty from MAKE Magazine repeated it, and it whipped his bro maker types into a frenzy. He eventually retracted it. 04-Jul-20 08:49 AM But it put her in an awful bind because admitting she’s a lesbian, while not... illegal... is a risk in PRC. (And under what circumstances is it EVER acceptable for people to be forced to out themselves as a defense against slander?) And defending that she, as a woman, made it all comes across as feminism, and that’s really dangerous for a PRC woman to espouse. 04-Jul-20 08:49 AM VICE reneged on their deal and wantonly endangered her, after she arranged for them to visit her in PRC, just so they could introduce controversy into the story to get a few more clicks. 04-Jul-20 08:49 AM I find that reprehensible. Any TOS violation in subtly doxxing a VICE editor after they did this to her should be viewed in that light, and I find what Patreon did reprehensible. 04-Jul-20 08:49 AM As such, I do not subscribe to any Patreons, and I avoid clicking on any VICE links to deprive them of ad revenue, and I make the facts of this known when people talk about either company. 04-Jul-20 09:54 AM <𝓕ermion#6024> Hey does anyone have strong opinions on lock-ins? 04-Jul-20 09:54 AM <𝓕ermion#6024> Zurich instruments seems to make a nice one but idk, they're kinda new 04-Jul-20 09:54 AM <𝓕ermion#6024> SRS is pretty well trusted but I think their power supply/thermal engineering is trash 04-Jul-20 09:54 AM <𝓕ermion#6024> Ametek/PAR is like... great, but old as hell now 04-Jul-20 09:54 AM <𝓕ermion#6024> idk. 04-Jul-20 09:54 AM <𝓕ermion#6024> they're all a bit dodgy IMO 04-Jul-20 09:55 AM we have about a dozen lock-ins 04-Jul-20 09:55 AM the old ones not being used are Princeton Applied Research 04-Jul-20 09:55 AM and ALL the newer ones are SRS. 04-Jul-20 09:56 AM <𝓕ermion#6024> yeah... seems like everyone just buys SRS 04-Jul-20 09:56 AM One of the undergrad labs has like ten SRS ones, they occasionally have to be repaired in the electronics shop but AFAIK it has always been pretty simple repairs 04-Jul-20 09:57 AM <𝓕ermion#6024> yeah... I repaired an SRS lna from a trash pile and it was easy 04-Jul-20 10:01 AM I think the SRS ones people use are ancient too though ? 04-Jul-20 12:39 PM In case anyone is building their own Calutron, note that mice can cause virtual vacuum leaks. 04-Jul-20 12:39 PM https://twitter.com/wellerstein/status/1278394094134398976?s=21 04-Jul-20 12:39 PM I can’t make this stuff up. 04-Jul-20 12:39 PM + 04-Jul-20 12:43 PM Reminds me of the dummy form I generated to test a new IR form program earlier today 04-Jul-20 12:43 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-E0EDE.png 04-Jul-20 02:12 PM <𝓕ermion#6024> has anyone designed eurocards before? I'm having a hard time finding the front panel mounting hardware 04-Jul-20 02:12 PM <𝓕ermion#6024> the screws with the little plastic push nut in them, the handle, etc. 04-Jul-20 02:12 PM <𝓕ermion#6024> I guess vector makes L-brackets 04-Jul-20 08:09 PM Naomi Wu ( A fellow hack a day contributor) has weathered many storms and will continue to do so. Vice was particularly egregious because from what they printed it was possible that people could actually figure out who she really is. Obviously her persona is a nome de plume. She is very pro China in everything she does so I do not believe there is any real risk of governmental/party issues for her, but as she has said many times China is still a very conservative country socially. She can always put on a sweater and blend right into the background of schenzhen if she ever needed to. The whole demonetizing people is just another extension of our current cancel culture. So people don’t like her cause she got a boob job. That is about as rediculous a thing to dislike somebody as I have ever heard. They don’t like her because she takes the pro China stance on all the usual things China is guilty of and you could possibly make that argument, but No shock there cause she is Chinese and very proud of it. It is still no reason to try to deny somebody their career. Even though we probably don’t see eye to eye on politics I think it is wonderful that she shows the rest of the world her life and how she lives it. 04-Jul-20 09:08 PM well, patreon and youtube as a career is pretty laughable 04-Jul-20 09:08 PM I mean, it's not cool to selectively enforce or skip on enforcing TOS/laws 04-Jul-20 09:08 PM I guess it sounds pretty much like "starving artist" 04-Jul-20 10:03 PM I wouldn't discount the risk she faces from the CCP. At one point, she was picked up by authorities and briefly detained. It sounds like some of her video was taken out of context by someone and used without her approval, which spooked the govt. 04-Jul-20 10:03 PM Also, I want to be careful of how "cancel culture" gets used. 04-Jul-20 10:03 PM When we're talking about unrepentent, powerful people, I think "cancelling" is a very good, justified thing. 04-Jul-20 10:03 PM She isn't in any position of power. Quite the contrary, she was being picked on by a US media empire. 05-Jul-20 02:18 AM @rdpierce redirect the rants into #off-topic-thats-sometimes-on-topic in the future, please 05-Jul-20 10:01 AM This morning I did a little dive on what’s going on with YouTube tech people in China. Evidently they are beginning to arrest and disappear people with you tube channels. Westerners especially. Many of them are now trapped in Hong Kong which itself is having massive problems. 05-Jul-20 10:05 AM wat? 05-Jul-20 10:05 AM and y? 05-Jul-20 10:27 AM Source? 05-Jul-20 11:21 AM Shouldn't we be taking this to #off-topic-thats-sometimes-on-topic as requested? 05-Jul-20 12:05 PM Agreed 05-Jul-20 06:06 PM Joined the server. 05-Jul-20 06:07 PM <𝓕ermion#6024> has anyone laid out a PCB with an 18-bit dac on it? 05-Jul-20 06:07 PM <𝓕ermion#6024> wondering if board-level shielding will help with EMI immunity 05-Jul-20 06:07 PM <𝓕ermion#6024> it's gonna be in the same box as a rpi 06-Jul-20 03:53 AM I've looked into a lot of ADC stuff more than DAC, and yeah after 16 bits you've gotta be careful. A metal can around the sensitive bits (i.e. unbuffered), maybe split up the ground plane and separate the analog from the digital, prevent signal crossings... (all based on readings and not practice). 06-Jul-20 07:58 AM Star grounding, separate high-cmrr linear supplies and careful filtering of any crossings becomes rather important yeah. Coupled noise is a pain to deal with, but if you want peak performance a solid shielding can is nice. Try to keep any stray current paths away from the analog area and keep all switchmode supplies and fast data lines as fra away as possible, a far corner of the board is usually a good spot. Other than that construction becomes really annoying real fast, noise always finds a way Good luck, but a little digital prefiltering is always a good bandaid. 06-Jul-20 11:16 AM Thought my gauge had broken but nope a cable just decided to die on the weekend 06-Jul-20 11:46 PM sooo, should I get a 6" iso100 bellow, or a 10" ? 06-Jul-20 11:46 PM to connect the turbo/pump station to the chamber I'm building, which will (hopefully) someday be used for DRIE/plasma stuff 06-Jul-20 11:46 PM it's gonna be installed in a server rack 06-Jul-20 11:46 PM I'm thinking the 10" won't really afford me much, except maybe some extra arm room between the two shelves/equipment 06-Jul-20 11:46 PM otherwise, it will obv require more vertical height... but the rack is 7ft, which is more than I think i'll ever use 07-Jul-20 09:26 AM Same bellows material? They vary a lot. Sometimes longer isn’t actually more flexible... 07-Jul-20 10:36 AM Does anyone have a favourite basic loggable water temp sensor? Want something to keep an eye on my water outlet. +/- 5C would be fine... 07-Jul-20 10:43 AM DS18B20 chip. 07-Jul-20 10:43 AM Brewing automation suppliers sell them in probe form in 1/4” stainless steel sleeves. 07-Jul-20 10:43 AM Buy a T fitting. 07-Jul-20 10:43 AM Buy a SwageLok adapter that goes from the fitting to 1/4” tube. 07-Jul-20 10:43 AM You can insert the probe into the junction of the T so it is in the water flow. 07-Jul-20 10:43 AM Either use the SwageLok hardware and permanently swage onto the probe. 07-Jul-20 10:43 AM Or pull out the internal metal fittings and replace with O rings that will compress when the fitting is tightened. That probably won’t leak and can be disassembled. 07-Jul-20 10:43 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image-6DC98.png 07-Jul-20 10:43 AM You can see a T and a probe on the right side of the central barrel. 07-Jul-20 10:54 AM Neat! I wonder if Mcmaster has one of those or something similar 07-Jul-20 10:54 AM DS18B20 use Dallas OneWire protocol. It’s essentially I2C without a separate clock line. You can read it via Arduino, Raspberry Pi, etc. 07-Jul-20 10:55 AM Ideal for me would actually be 0-5V analog but that's fine to just pad with an arduino 07-Jul-20 10:56 AM The beauty of it is you can daisy chain as many of the sensors as you want into a bus. It’s a digital bus. Each sensor has its own equivalent hardware address. You can interrogate the bus for a list of them, send a broadcast command to tell each to latch the current temperature, and poll each in turn. 07-Jul-20 10:56 AM There are libraries to do it. Sensor is readable to 12 bits. 07-Jul-20 10:56 AM Although at that precision, it takes around 750 ms to do a conversion. You can tell the sensor to use less precision, which reduces the conversion time. 07-Jul-20 10:56 AM 12 bits = 1/16 degree C 07-Jul-20 11:02 AM mcmaster only has prebuilt thermometers, ugh 07-Jul-20 11:02 AM If you want 1/2 degree C resolution, you can get it in <100 ms. 07-Jul-20 11:02 AM I said 5C 07-Jul-20 11:02 AM I just want to know if the thing leaves the 25C steady state before it hits the 50C issues 07-Jul-20 11:03 AM https://www.mouser.com/ProductDetail/DFRobot/DFR0198?qs=Zcin8yvlhnPOt9ZkO3roFQ%3D%3D&gclid=EAIaIQobChMI_OCp1ty76gIVBL7ACh1MrwDrEAQYASABEgKj1PD_BwE 07-Jul-20 11:03 AM I use these for precision control of beer brewing. I also did work for a licensed micro distillery and instrumented one of their stills. 07-Jul-20 11:03 AM I don’t see a diameter listed on that part. I’d guess 1/4” but you many want to check. 07-Jul-20 11:05 AM so @ $31 shipped, anything better from Amazon? a week or so lead time is fine 07-Jul-20 11:05 AM yeah it's cheaper on amazon when you include shipping 07-Jul-20 11:07 AM Ehhhh.... that part is 6mm. Not 1/4”. 07-Jul-20 11:07 AM https://www.dfrobot.com/product-689.html 07-Jul-20 11:08 AM NBD since I have to buy the fitting anyways. It will be going in 3/4" tubing 07-Jul-20 11:09 AM https://www.amazon.com/dp/B07QM3W7XJ/ref=sspa_dk_detail_3?psc=1&pd_rd_i=B07QM3W7XJ&pd_rd_w=TPP4c&pf_rd_p=48d372c1-f7e1-4b8b-9d02-4bd86f5158c5&pd_rd_wg=I5ayb&pf_rd_r=R7E2S3MT737J3T1SCVS2&pd_rd_r=9f817d88-8a03-4be0-8d8f-4f055767b8e3&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUFKODVBVjlXRklMT1MmZW5jcnlwdGVkSWQ9QTA2ODgyODY0TUNJRUg4SE5MVTMmZW5jcnlwdGVkQWRJZD1BMDA2NDIzMzJFTVYyRjVTSzBNNk8md2lkZ2V0TmFtZT1zcF9kZXRhaWwmYWN0aW9uPWNsaWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl 07-Jul-20 11:09 AM Never mind, that one is a thermocouple. 07-Jul-20 11:11 AM .ca 07-Jul-20 11:11 AM anyways there are lots of DS18B20, I have a bundle of arduino nanos I can use to convert to 0-5V 07-Jul-20 11:11 AM thanks, wish mcmaster had something since I have to order a bunch from them anyways 07-Jul-20 11:12 AM They have analog output? Not PWM? 07-Jul-20 11:12 AM What are you measuring water for? 07-Jul-20 11:17 AM I want to figure out what flow rate to use 07-Jul-20 11:17 AM since we struggle with balancing it and the less each device gets the better 08-Jul-20 07:09 AM Most low cost flow rate sensors these days are either direct revolution count paddle wheels via reed switch or pulse per volume types. How large are the pipes and what are the flow rates you are looking at? 08-Jul-20 07:46 AM Around 6L/minute, 3/4" OD reinforced vinyl tubing 08-Jul-20 07:46 AM I need to measure temperature, the water source temperature fluctuates so flow rate is insufficient 08-Jul-20 02:05 PM @idmb hmm not sure about the material of the bellows, that's a good point. I don't think I need much flexing though, the items should be able to be pretty much in line above each other 08-Jul-20 02:05 PM Any ideas on how thick a chamber wall needs to be if you were building something like a 2ft per side cube? 08-Jul-20 02:05 PM There's some 1/4" stainless (304) available locally for what seems like a good price 08-Jul-20 02:16 PM I've never done cubes 08-Jul-20 02:16 PM The way the bellows are formed matters a lot. We have some 3" long bellows that allow more movement than some of our 12" bellows 08-Jul-20 02:16 PM (same OD) 08-Jul-20 02:32 PM Hmmm 08-Jul-20 02:32 PM I have a feeling I'll end up with one of each 08-Jul-20 02:32 PM I'm not sure I want to do an cylinder chamber, mostly just because I need it to be at least 24" wide in one direction, and maybe more. Idea is for a n aluminum coater, and I was thinking that I might need to move the substrate around to get an even coating (since the evaporation has some directionality, right?) 08-Jul-20 02:37 PM Come and get it? 08-Jul-20 02:37 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-F9CBF.jpg 08-Jul-20 02:39 PM Hmm, looks mayybe big enough 08-Jul-20 02:39 PM I need to prototype the evaporator stuff, then if that works build a few of these I think 08-Jul-20 02:39 PM those are CF10 flanges so I'm pretty sure it is 08-Jul-20 02:40 PM Yeah seems like there's probably 8 of them 08-Jul-20 02:40 PM 80/3.14 = 25.47 inches 08-Jul-20 03:34 PM Holy moly I love gate valves 08-Jul-20 03:34 PM so many troubleshooting options with like 1-2 hour turnaround compared to 1-3 days 08-Jul-20 05:25 PM As compared to? 08-Jul-20 05:26 PM having to open all chambers every time you have to do something on one of them 08-Jul-20 07:38 PM Ooo, hmm, that much different than a chamber door? 08-Jul-20 09:48 PM https://www.amazon.com/dp/B077H8B6S1/ref=cm_sw_r_oth_api_i_IdQbFb5PSD972 Here is an example of the little flow sensors. You have to figure out the calibration for yourself but they are super cheap. They generally have a 5 ms output pulse, or they clamp. Usually the frequency is proportional to the flow. 08-Jul-20 09:59 PM But I want to measure the water temp to control flow, rather than measure flow... 08-Jul-20 09:59 PM It doesn't matter how much water is going through the device, what matters is whether it overheats 09-Jul-20 01:21 AM I'd say grab a ds18b20 and an arduino nano, it shouldn't take too much coding to write a digital to analog converter 09-Jul-20 01:21 AM and from the looks of the nano, they're 5V output on the GPIO 09-Jul-20 01:21 AM you'd basically just import the onewire library, setup the ds18b20 on the pin of your choice, then have a loop that reads the sensor, scales to the range you want, then does an analogWrite on the output of your choice 09-Jul-20 01:21 AM you're basically looking at less than $10, not including your time 09-Jul-20 01:21 AM you'd want a capacitor on the output pin, probably a small resistor too 09-Jul-20 01:21 AM (to smooth the PWM output to a stable voltage) 09-Jul-20 07:03 PM Hi all, a few friends of mine and I are trying to raise money for the Rhode Island Community Food Bank and the COVID-19 Solidarity Response Fund. They're severely underfunded at the moment and our governor doesn't seem to be paying them a great deal of attention. These people provide a very necessary service to our community, the lives of many depend upon their ability to continue operating. As a result, we formed a small group with a few local high school kids to help support what these organizations are doing and make sure that our fellow citizens are cared for. We'd really appreciated if you'd chip in however much you felt was appropriate, we fully understand that times are tough; anything you could give helps. https://gf.me/u/x48yxs 10-Jul-20 12:12 PM <𝓕ermion#6024> is it just me or are neslab chillers really terrible? 10-Jul-20 12:12 PM <𝓕ermion#6024> I was in a lab with maybe 15 or so system Is and one was always dying... that may just be a law-of-large-numbers thing 10-Jul-20 12:12 PM <𝓕ermion#6024> but they really would fail so often that we put quick-disconnects on the pumps so we could switch them out as they died 10-Jul-20 12:12 PM <𝓕ermion#6024> we then switched to Haskris chillers and they were much better 10-Jul-20 12:13 PM never had either 10-Jul-20 12:13 PM <𝓕ermion#6024> so like... I really wanna pick a fight with my PI over buying haskris over neslab but I can't tell if it's worth it. 10-Jul-20 12:13 PM lytron and polyscience 10-Jul-20 12:13 PM <𝓕ermion#6024> hmm okay. 10-Jul-20 12:13 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-22FC0.jpg 10-Jul-20 12:13 PM these guys are trash 10-Jul-20 12:13 PM we have had five die 10-Jul-20 12:14 PM <𝓕ermion#6024> well okay... not chiller, but heat exchanger. 10-Jul-20 12:14 PM <𝓕ermion#6024> I shouldn't say chiller 10-Jul-20 12:14 PM <𝓕ermion#6024> we have building chilled water but it's gross. 10-Jul-20 12:14 PM They're sold as chillers ? 10-Jul-20 12:15 PM <𝓕ermion#6024> they're sold as heat exchangers. 10-Jul-20 12:15 PM <𝓕ermion#6024> neslab W/W series I is what I'm looking at 10-Jul-20 12:15 PM <𝓕ermion#6024> they actually use the same pump as soda fountains. 10-Jul-20 12:15 PM the polyscience 6000 we have seem solid 10-Jul-20 12:15 PM <𝓕ermion#6024> hmmm okay. 10-Jul-20 12:15 PM except they have a blue LED front panel 10-Jul-20 12:15 PM which I can't read from 6m away 10-Jul-20 12:15 PM They're expensive though. 10-Jul-20 12:15 PM (The lytron ones we have have failed several times but the company let us keep the broken ones so we have a parts bin..... yay?) 10-Jul-20 12:21 PM <𝓕ermion#6024> man I just hate the thought of an unreliable chiller 10-Jul-20 12:21 PM <𝓕ermion#6024> especially during a pandemic 10-Jul-20 12:21 PM <𝓕ermion#6024> this thing is going in the basement anyway 10-Jul-20 12:21 PM <𝓕ermion#6024> like I would just buy the neslab and wait for it to break and go "see? let's buy a haskris" 10-Jul-20 12:21 PM <𝓕ermion#6024> but sunk costs. 10-Jul-20 12:28 PM I'm so glad that our house chilled water is good honestly 10-Jul-20 12:28 PM Even if the rest of the building is...not great 10-Jul-20 12:28 PM At least we have that 10-Jul-20 12:28 PM <𝓕ermion#6024> yeah. 10-Jul-20 12:29 PM Though house air went down this week which was uggghhh 10-Jul-20 12:29 PM <𝓕ermion#6024> my old school's chilled water was so bad it electroplated the pumps. 10-Jul-20 12:29 PM Yikes 10-Jul-20 12:29 PM <𝓕ermion#6024> f o r b i d d e n l e m o n a d e 10-Jul-20 02:51 PM Anybody have access to a vacuum melting rig? I will eventually need to have a small amount of nickel/cobalt alloy made and have it rolled down to ribbon. For years I have been trying to find it but nobody has it anymore. It’s critical it has nearly zero manganese, very little if any chrome,and controlled amounts of other things that precludes the use of the standard available alloys. 10-Jul-20 02:51 PM Somebody somewhere has to have the setup to make special alloy wires if not only for research. 10-Jul-20 02:51 PM If I wanted 50,000 kg it would be no problem. I just need a few Kg that would last me forever. 10-Jul-20 08:40 PM <𝓕ermion#6024> anyone have a CERN account? 10-Jul-20 08:50 PM @𝓕ermion just have two chillers in parallel with a solenoid valve to switch to the backup when the main one fails :))) 10-Jul-20 08:51 PM <𝓕ermion#6024> there's some option where they'll put a fancy turbine pump on instead of a PD pump 10-Jul-20 08:51 PM <𝓕ermion#6024> I'll just do that... 10-Jul-20 08:51 PM <𝓕ermion#6024> and I actually don't have enough room on the rack to do that 10-Jul-20 08:51 PM <𝓕ermion#6024> the chiller is going in the basement on a pallet with 10 other boxes of equipment... chillers, compressors, stuff like that. 10-Jul-20 08:51 PM <𝓕ermion#6024> and one professor has generously given us one square for the chiller and one square for the compressor 10-Jul-20 08:51 PM <𝓕ermion#6024> the floor is always wet because something failed and is leaking lol 10-Jul-20 10:31 PM Yikes 10-Jul-20 10:31 PM Can’t you stack stuff? 11-Jul-20 11:15 AM any suggestions on a cheap, simple-to-move (wheeled?) cart/table for turbomolecular pump + rotary vane + chamber on top? and perhaps some other equipment stacked. not sure how fixed/stable/strong it needs to be with a TMP 11-Jul-20 11:25 AM my understanding is that moving a running TMP will very likely crash it, so whatever it is it needs to be extremely rigid when locked in place 11-Jul-20 11:25 AM the backing+tmp pumping stations i've seen are all like stationary units 11-Jul-20 11:25 AM i'd considered putting my everything on a 24U wheelie server rack but i couldn't hope to get it bump-proof enough without taling the wheels off 11-Jul-20 11:28 AM You could always apply some small extending feet to get the moving cart of it's wheels and locked into place 11-Jul-20 11:28 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/31jv8AcnrKL-F6BCB.png 11-Jul-20 11:28 AM ooh 11-Jul-20 11:29 AM But yeah, I wouldn't dare move a TMP whatever bearings it has in place, do they even make any that can be moved in operation? 11-Jul-20 11:30 AM doubtful, they need those virtually nonexistent mechanical clearances to do their thing 11-Jul-20 11:30 AM maaaaybe a drag pump could tolerate it? dunno 11-Jul-20 11:30 AM that or get a diffusion pump :D 11-Jul-20 11:33 AM ahh i see. i like the locking idea 11-Jul-20 11:33 AM i do want to be able to move it when not in use 11-Jul-20 11:33 AM i have some weight bearing linear actuators so could have an mcu only engage the TMP once the actuators are up 11-Jul-20 11:35 AM neat :D yeah i was thinking 'hmm how could you interlock this..' 11-Jul-20 11:37 AM and an IMU or limit switches just to confirm they're all raised 11-Jul-20 01:05 PM TMPs doesnt have to be "rock solid" when spun-up, you should just not to move them "significantly" - at least as long those are not fully magnetic levitated. Our leak tester (Pfeffier HLT570 containing Splitflow 80 TMP - almost same pump as "ordinary" Hipace 80) is mounted on "common" movable toolbox and when we use it, we just lock the wheels and thats all... 11-Jul-20 01:14 PM Here are the original instructions for the leaktester. 11-Jul-20 01:14 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-65F0D.png 11-Jul-20 01:19 PM I've got a 7ft server rack that I plan on putting a turbo into.... it's got wheels but also little legs that come down and tighten to the floor 11-Jul-20 01:20 PM Yeah I don’t move any but our neighbours have a couple carts with turbos. They move them while on all the time. I think only newer maglevs are OK with it? 11-Jul-20 01:20 PM And by move I don’t mean anything substantial, just gently moving the cart. 11-Jul-20 01:27 PM brave 11-Jul-20 01:38 PM oh man, just envisioned a diff pump system heated by an internal combustion engine's waste heat 13-Jul-20 04:12 PM <𝓕ermion#6024> Just got an Edwards nxr60i pump 13-Jul-20 04:12 PM <𝓕ermion#6024> It’s so cute 13-Jul-20 04:12 PM <𝓕ermion#6024> Tiny lil roots pump 13-Jul-20 04:59 PM Cute! I like the iGX dry screws 13-Jul-20 05:19 PM <𝓕ermion#6024> Yeah! It's got a pretty high frequency whine that I don't love unfortunately 13-Jul-20 05:19 PM <𝓕ermion#6024> but it's definitely quieter than the alcatel roots blowers 13-Jul-20 05:19 PM <𝓕ermion#6024> it's all very intelligent... soft start and automatic switching between three phase and single phase. I think it's got a pretty smart VFD in there. 13-Jul-20 05:19 PM <𝓕ermion#6024> we'll see how it does on my 3he fridge 13-Jul-20 05:19 PM <𝓕ermion#6024> I also got a few SMUs, a fiber-attached high speed digitizer... so many new toys. 13-Jul-20 05:28 PM the iGX has a similar annoying high frequency 13-Jul-20 05:28 PM Not especially high, but the whole 55dB they quote is quite concentrated... 13-Jul-20 05:29 PM <𝓕ermion#6024> Yeah that's right. 13-Jul-20 05:29 PM <𝓕ermion#6024> I'm sure there's some planetary gearbox in there 13-Jul-20 05:33 PM Also the iGX600L water outlet doesn't heat up at all if the system is overheating because you're not flowing water through it 14-Jul-20 12:12 PM @ericdalgetty would you mind putting your youtube channel link in your introduction? 14-Jul-20 12:20 PM Of course, I wasn't sure if posting links was alright. I'll post it here and there! 14-Jul-20 12:20 PM www.youtube.com/c/Ericdalgetty 14-Jul-20 12:26 PM edit it into your comment 14-Jul-20 12:26 PM for conciseness 14-Jul-20 12:26 PM instead of a separate comment on that thread 14-Jul-20 12:37 PM ^ 14-Jul-20 12:37 PM And I assume your channel has some stuff about the rough pump idea? That's a new one to me personally. Is it just checking that the foreline pressure is acceptable for the turbo and kicks on when it goes below some threshold? 15-Jul-20 07:03 AM Exactly. It will pump until the foreline is below 40 mtorr and then hold that for a few minutes. Then it follows a cycle to turn off the roughing pump and bring its inlet back to atmosphere (its not good to start a roughing pump under vacuum). Once the foreline pressure goes back above 100 mtorr, the roughing pump will kick back on and that cycle repeats. In my system this is about once every 10 hours 15-Jul-20 07:20 AM Why is it a bad thing to start a roughing pump under vacuum? Some pumps that I have worked with build some pressure on the vacuum side when turned off. I think it was like 10-100 mBar. Is it harmful to start the pump at such pressures? 15-Jul-20 07:24 AM What type and brand of pump? 15-Jul-20 07:44 AM Hitachi 160VP and Pfeiffer Vacuum DUO 016B Both are dual stage rotary vane pumps. Not sure about the Pfeiffer's vacuum side pressure after turnoff. The Hitachi was very worn when I gave it a thorough clean 15-Jul-20 08:11 AM From the pump side there is no real issue. They actually start more easily at vacuum. They work harder when pumping air. The electric motor side is more of the issue. You are going to wear it out faster as generally a properly sized electric motor on a pump wears the most when turning on. Being that your cycle rate is very slow you should get a reasonable life. The more common scenario is for large systems there are is a large pump for initial pump down then a small less power hungry pump to maintain. Since you are starting with a small pump your approach may be better. I caution you on one thing though. The inlet valve of these types of pumps are notorious for leaking spontaneously sucking a bunch of pump oil back into your system at the worst possible time and when you turn the pump back on you are not forcing uncompressable oil back through the pump which can basically lock rotor it. Bad times. 15-Jul-20 08:11 AM That’s why I use belt drive pumps only. You can turn them by hand when bad things like that happen to clear it out and get it free before burning up the motor. 15-Jul-20 08:36 AM Thanks! I guess motor wear is not an issue in my case, as the pumps only start a few times per month on average. I'm aware of the oil suckback issue and it is addressed at the applications where these two pumps were used. Do you know about rotary vane pump oils? I can't find data about that Hitachi 160VP Pump. I recently drained it's oil and it was somewhat dark brownish with lots of particles in it. I decided to disasemble the pump to thoroughly clean it as it had definitely been running for a very long time without service. I had some Oil around that literally just says "Vacuum Pump Oil" and that it is some sort of petroleum raffinate. It has a rather transparent yellow color. I guess it's still better than the ugly worn-out oil that the pump had before. Final pressure is all-right. Should I get some quality rotary-vane pump oil or is just about any petroleum raffinate fine? I have changed other pumps oils with their designated oil, which was colorless when fresh... 15-Jul-20 09:40 AM I think that you should mainly care about vapor pressure. If this generic "vacuum pump oil" has acceptable datasheet vapor pressure, then it should be allright. I would not try using any "random" oil without knowing this parameter... 15-Jul-20 10:00 AM Final pressure is ~3*10^-2 mBar. The manufacturer does not tell anything about vapor pressure in the datasheet. So far I had only ever used fresh oil for rotary vanes that was colorless and fully transparent, like Pfeiffer P3 Oil 15-Jul-20 10:31 AM who wants to play "guess that gas" 15-Jul-20 10:31 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-8D564.png 15-Jul-20 10:37 AM I see water 15-Jul-20 10:37 AM and oxygen / nitrogen 15-Jul-20 10:37 AM and some Hydrocarbons? 15-Jul-20 10:42 AM Well yeah but where did they come from! 15-Jul-20 10:43 AM I thing that's the human Touch everyone is talking about 15-Jul-20 10:45 AM RGA says 32 is 4E-12 lol 15-Jul-20 10:45 AM lucky me wanting to look at S+ ions 15-Jul-20 10:45 AM (also O2 gets filtered through detection anyways) 15-Jul-20 11:21 AM @ericdalgetty why not just cycle an isolation valve, and keep the pump running? 15-Jul-20 11:21 AM I did that using a raspberry Pi and mks901p 15-Jul-20 11:21 AM (and solenoid controlled pneumatic valves) 15-Jul-20 11:21 AM Except my targets were more like <500mTorr and 10 torr 15-Jul-20 11:21 AM Oh, your time is 10 hours, I guess thats a while to run the pump for "no reason" 15-Jul-20 11:43 AM Exactly :) also all my equipment runs in the house so I try not to spend too much on electricity/ keep things quiet 15-Jul-20 02:27 PM <𝓕ermion#6024> hey folks, I'm in an enormous bind. I need to find a neslab system I 15-Jul-20 02:27 PM <𝓕ermion#6024> or alternatively, I need to find something with similar size and cooling capacity 15-Jul-20 02:27 PM <𝓕ermion#6024> I like haskris heat exchangers a lot but they're pretty big 15-Jul-20 02:27 PM <𝓕ermion#6024> I just have no room to work with 15-Jul-20 06:43 PM <𝓕ermion#6024> I'm down to bay voltex, haskris, coherent laserpure, SMC HRW, and lytron 15-Jul-20 06:43 PM <𝓕ermion#6024> anyone have experience with any of these? 15-Jul-20 08:03 PM <𝓕ermion#6024> oh and polyscience! 15-Jul-20 08:55 PM my laser is cooled with two Polyscience 6700T 3/4HP chillers. They've been fine? they have a water-water version too I believe 15-Jul-20 08:55 PM come with nicer castors than the lytron lol 15-Jul-20 08:57 PM I'll check what we have for the water cooled turbo tomorrow, but it works fine besides the pump having this annoying tendency to get copper acetate in the seal which makes the seal fail and leak periodically 15-Jul-20 08:57 PM But I think that's more a water pump issue and less a that particular pump issue 15-Jul-20 08:57 PM we just hve computer fans zip tied to some of our water cooled turbos 15-Jul-20 08:57 PM <𝓕ermion#6024> Lol... 15-Jul-20 08:58 PM my turbo is chilled with a small portion of my roughing pump's water, which is from the building. 15-Jul-20 08:58 PM <𝓕ermion#6024> Yeah our building’s water is like oatmeal lol 15-Jul-20 08:58 PM good enough to chill a polyscience chiller though? 15-Jul-20 08:58 PM <𝓕ermion#6024> Yeah. 15-Jul-20 08:58 PM or you can get a sacrificial fan coil 15-Jul-20 08:58 PM Honestly, that fact still surprises me. I kind of figured it'd be like JILA there where everything is stupidly top of the line 15-Jul-20 08:59 PM we got a "2 ton" fan coil which we use to supplement the rest of our pumping room when the HVAC breaks every summer 15-Jul-20 08:59 PM <𝓕ermion#6024> Is JILA like that? 15-Jul-20 08:59 PM Supposedly 15-Jul-20 08:59 PM I dunno if it's true 15-Jul-20 08:59 PM <𝓕ermion#6024> Yeah MIT is a mess 15-Jul-20 08:59 PM <𝓕ermion#6024> It’s a pretty functional mess 15-Jul-20 08:59 PM <𝓕ermion#6024> But yeah. 15-Jul-20 09:00 PM Well, I know JILA does in fact do a bunch of things to reduce interference 15-Jul-20 09:00 PM But I dunno if the other stuff is true 15-Jul-20 09:00 PM we have rat traps in my office and they apparently find one every ~3-5 years. 15-Jul-20 09:00 PM <𝓕ermion#6024> Oh we have horrible electrical noise 15-Jul-20 09:00 PM We have horrible electrical noise too 15-Jul-20 09:00 PM <𝓕ermion#6024> Just 180 Hz in EVERYTHING 15-Jul-20 09:00 PM And we're also right next to the football stadium at one of the top football schools in the country which isn't great 15-Jul-20 09:01 PM <𝓕ermion#6024> Aw dude 15-Jul-20 09:01 PM For me it's mostly fine 15-Jul-20 09:01 PM Though the frequency comb lab 15-Jul-20 09:01 PM They're less lucky 15-Jul-20 09:01 PM <𝓕ermion#6024> Yeah I just need to convince my PI that we just can’t get a neslab. 15-Jul-20 09:02 PM hire an undergrad to make a chiller from first principles, given only access to raw materials 15-Jul-20 09:02 PM <𝓕ermion#6024> The IIs are too tall, IIIs too big, and Is just totally unavailable. 15-Jul-20 09:02 PM <𝓕ermion#6024> So polyscience seems like it’s the best bet. 15-Jul-20 09:02 PM Is that alone not enough to convince him to not do it? 15-Jul-20 09:02 PM <𝓕ermion#6024> No. 15-Jul-20 09:02 PM Ow 15-Jul-20 09:02 PM <𝓕ermion#6024> He’s very stubborn. 15-Jul-20 09:03 PM FWIW both spectra physics and coherent are using polyscience nowadays, or at least were a year ago 15-Jul-20 09:03 PM <𝓕ermion#6024> He will likely ask me to buy a broken one on eBay and send it to a refurb company to have it guaranteed. 15-Jul-20 09:03 PM I guess I can understand that. I still need to figure out how I'm going to convince my boss that the ejection mechanism ISN'T evaporation... 15-Jul-20 09:03 PM <𝓕ermion#6024> Just so we can have a neslab. 15-Jul-20 09:03 PM <𝓕ermion#6024> And I hate neslab. 15-Jul-20 09:03 PM <𝓕ermion#6024> They’re not good. 15-Jul-20 09:03 PM <𝓕ermion#6024> We had like 12 system IIs in my old lab and they were just constantly breaking. 15-Jul-20 09:03 PM <𝓕ermion#6024> We put quick connects on all the pumps when we bought them 15-Jul-20 09:03 PM <𝓕ermion#6024> So we could switch out the pumps faster lolol 15-Jul-20 09:05 PM Does anyone not do that? 15-Jul-20 09:06 PM <𝓕ermion#6024> Oh we thought we were clever for doing that. 15-Jul-20 09:06 PM <𝓕ermion#6024> That’s a thing everyone does? 15-Jul-20 09:06 PM <𝓕ermion#6024> They’re that bad? 15-Jul-20 09:06 PM we do that for everything lol 15-Jul-20 09:06 PM except when pressure is a concern of course 15-Jul-20 09:06 PM <𝓕ermion#6024> Ah well. 15-Jul-20 09:07 PM Well, we usually just do compression fittings on everything unless we have a reason to not do compression fittings 15-Jul-20 09:07 PM gross 15-Jul-20 09:07 PM It really is 15-Jul-20 09:07 PM cpc quick disconnects are lovely, push-to-connect follow shortly after 15-Jul-20 09:07 PM But on the bright side, we have like two fittings 15-Jul-20 09:17 PM <𝓕ermion#6024> If you wanted a header with a bunch of valves on it for distributing nitrogen around the room, what would you use? 15-Jul-20 09:17 PM <𝓕ermion#6024> I was originally thinking of using a bunch of Swagelok valves but those are crazy expensive/overkill I think. 15-Jul-20 09:17 PM <𝓕ermion#6024> Maybe just a bunch of ball valves and push to connect fittings. 15-Jul-20 09:17 PM <𝓕ermion#6024> But I don’t really like those big ball valves. Would prefer something smaller and more compact. 15-Jul-20 09:49 PM nitrogen for what? 16-Jul-20 07:01 AM <𝓕ermion#6024> just random things. Two evaporators, blow guns for a bench, etc. 16-Jul-20 07:11 AM Can you just salvage old swagelok valves? 16-Jul-20 07:12 AM <𝓕ermion#6024> might be a good idea! 16-Jul-20 09:33 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-F9FB6.png 16-Jul-20 09:33 AM any guesses why just one out of four chambers, all pumped with the same roughing pump, is doing this? 16-Jul-20 09:33 AM that timescale is about 13 hours 16-Jul-20 10:15 AM solved: there was liquid CS2 inside the valve and those must just be temperature fluctuations 16-Jul-20 04:56 PM Has anyone seen or heard from @niflheim , they haven’t been around here in a while or on a different server and people were getting worried there given what they’d been working on 16-Jul-20 10:03 PM Nope. 17-Jul-20 09:23 AM @𝓕ermion check eBay. Heavily discounted SwageLok parts are there. 17-Jul-20 09:39 AM ^ true, hobbyist-level is potentially better than lab-discard level 17-Jul-20 09:39 AM since lab-discard = us plebs who overtighten everything 17-Jul-20 10:19 AM I’m talking new parts, not lab discard. 17-Jul-20 10:20 AM are the ebay parts actually new?... 17-Jul-20 10:21 AM Absolutely. SwageLok fittings and valves are commonly used at job sites. They’re purchased in surplus, since it isn’t efficient to have a crew of pipe fitters waiting because they ran out of fittings or valves. 17-Jul-20 10:21 AM And... when the job is done... I think you get the idea what happens. At least that’s my working hypothesis on why you can find parts like that well below retail and even wholesale prices. 17-Jul-20 10:24 AM I would assume you'd just put it in storage for the next job 17-Jul-20 10:24 AM I thought lots of the valves and stuff were just when industrial stuff redoes their lines, they use new valves 17-Jul-20 10:24 AM Yes. 17-Jul-20 10:24 AM They use new valves. 17-Jul-20 10:24 AM And they buy more than they need. 17-Jul-20 10:24 AM And they can fit in a lunch box. 17-Jul-20 10:24 AM I think the same thing applies to common, expendable tools. 17-Jul-20 07:26 PM @Addison-110m looking in the backlog, I don't see much more than some vacuum stuff cobbled together without decent looking mechanical stabilization, what were your concerns? 17-Jul-20 07:26 PM I've not heard from @AdamMcCombs in like 4 months, nothing on his Twitter in 5 17-Jul-20 07:39 PM Adam's on something of an internet vacation. As someone headed camping soon very intentional to the most radio dark place in America, I can't blame him. 17-Jul-20 07:39 PM I made a special safety sign for my office door and everything several years back. 17-Jul-20 07:39 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-EB10E.jpg 17-Jul-20 07:42 PM The words “home fluorine chemistry” were mentioned somewhere else 17-Jul-20 07:42 PM @funranium is that the place in West Virginia? 17-Jul-20 07:42 PM Or maybe normal Virginia 17-Jul-20 07:42 PM Or north Carolina 17-Jul-20 07:42 PM Hat Creek 17-Jul-20 07:43 PM West va 17-Jul-20 07:43 PM Mmm 17-Jul-20 07:43 PM With all the covid these days, I've just been assuming people have gotten that or their loved ones :( 17-Jul-20 07:43 PM @Addison-110m well I've got access to non-home HF, no less dangerous 17-Jul-20 07:43 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20200516_195048-F172A.jpg 17-Jul-20 07:43 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20200516_195650-A06B2.jpg 17-Jul-20 07:43 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20200516_195615-51050.jpg 17-Jul-20 07:52 PM Yeah, true. Though you’re not making it. I was just figuring I’d ask here given I know he had been decently active 17-Jul-20 08:11 PM ...home fluorine chemistry? 17-Jul-20 08:11 PM Very good chance they're dead if that's true 17-Jul-20 08:25 PM I step away and then I come back to of those phrases I never really want to see, "home fluorine chemistry". "Refreshing plutonium enema" is another one of those phrases. Here's hoping for the best. 17-Jul-20 08:26 PM Same here 17-Jul-20 08:26 PM Yeah, I don't know how true it is, but my undergrad ochem professor said you always knew who did fluorine chemistry because they were missing fingers... 17-Jul-20 08:27 PM So, rough pump in a server rack with an turbo/drag OK or nay? 17-Jul-20 08:27 PM And that's with an EH&S team and engineering controls 17-Jul-20 08:27 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/JPEG_20200717_202718-77647.jpg 17-Jul-20 08:28 PM I ran a hydrofluoric still for the isotope geochemistry lab as an undergrad because, per the lab manager, I was the only one who showed enough fear and respect. 17-Jul-20 08:28 PM Because when you absolutely, positively, must obliterate rocks nothing but fuming HF will do. 17-Jul-20 08:29 PM tbh that's part of why I'm glad that my lab is basically entirely combustion intermediates or astrochem research. The worst thing we work with is HCN 17-Jul-20 08:29 PM Rather than the inorganic side where HF is a fact of life 17-Jul-20 08:32 PM FUN FACT: the most interesting bits of fluoring chemistry tend to also be mercury chemistry. For when you MUST contaminate every surface and piece of equipment in the fume hood. 17-Jul-20 08:33 PM Actually our VUV source uses mercury, so I guess mercury is probably the worst thing we work with 17-Jul-20 11:59 PM HF would be a very fun molecule to centrifuge 17-Jul-20 11:59 PM But we have said no, absolutely not, goodbye. 17-Jul-20 11:59 PM Our worst are SO2, OCS, and CO. 17-Jul-20 11:59 PM Maybe some iodobenzene and iodomethane 18-Jul-20 03:17 AM Not sure if this is against the rules here but my job is looking for an EE and a test engineer. We still pretty small company based just outside of Vienna and do plasma propulsion. Looking for people who have experience in HV electronics design for space and/or vacuum systems. Only language requirement is English. 18-Jul-20 02:50 PM View port on plasma chamber OK? 18-Jul-20 02:50 PM Says 200C max temp 18-Jul-20 02:50 PM But not sure how to calculate what it might be inside... Isn't it like 10s of 1000s deg C? 18-Jul-20 02:50 PM Does that mean I'm required to have some sort of magnetic confinement?? 18-Jul-20 02:50 PM "Argon ICP plasma discharge temperatures are typically ~5,500 to 6,500 K and are therefore comparable to that reached at the surface (photosphere) of the sun" 18-Jul-20 02:54 PM but temperature isn't everything 18-Jul-20 02:54 PM I've had ICP in a small quartz tube and it got up to ~300°C 18-Jul-20 02:54 PM question is if you plasma doesn't touch the glass how much it radiates and how much of that the glass absorbs 18-Jul-20 02:54 PM and if it touches the glass what's the actual power it has, eg. a halogen bulb is also pretty damn hot and can easily be held in a glass tube 18-Jul-20 02:54 PM look at most fusors, they have a window ^^ 18-Jul-20 04:16 PM You have to look at the radiative heat load and maybe consider a thermocouple on the interior to measure the glass. 18-Jul-20 04:16 PM (Connected to an interlock of course) 18-Jul-20 04:16 PM I think in most cases one wouldn’t bother as the overall heat load is small? 18-Jul-20 04:24 PM Anyone have thoughts on using a turbopump as a steam turbine? I imagine temp would be an issue but just brainstorming. 18-Jul-20 04:46 PM The motor is in the vacuum portion of the pump. 18-Jul-20 04:46 PM So I would be concerned what Steam would do for the windings. 18-Jul-20 04:46 PM Heheh. Autocorrect wants to capitalize steam. 18-Jul-20 04:46 PM Also the lubrication for the non magnetically levitated bearing. 18-Jul-20 04:46 PM I’d be worried about turbulence bouncing the rotors around, given the tight tolerance. 18-Jul-20 04:46 PM Which end would the Steam come in? The exhaust port? 18-Jul-20 05:05 PM Yea I figure feeding steam into the backing pump port. For cooling and lubricating bearings probably could use an intercooler and circulating oil since I'd not be dealing with a vacuum and can use normal oil. I don't think turbulence would be difficult to mitigate. Most ideally I'd extend the rotor shaft and drive a different rotor/generator as I don't think I'd be able to capture a whole lot of energy without overheating the windings due merely to load (e.g. even if heat from steam were mitigated) 18-Jul-20 05:05 PM Mostly I'm thinking along the lines of rotor stator/vanes setup being conducive to harvesting energy from the steam. I know "proper" steam turbine maintain constant pitch across all rotor/stator vanes but expand in diameter 18-Jul-20 05:36 PM What about using an automotive turbocharger turbine? 18-Jul-20 05:36 PM I’ve also heard of people turning turbochargers into jet engines. 18-Jul-20 05:36 PM Sorry, I’m cringing at the thought of destroying a perfectly good turbopump. 18-Jul-20 05:43 PM Tossing rid of a bunch of CAMAC gear. Let me know if you want something, especially if you are by Santa Clara CA and I can just give it to you. There's more than this but this is a basic idea: https://siliconpr0n.org/uv/nuc_equip.jpg 18-Jul-20 05:43 PM PM me if interested 18-Jul-20 06:02 PM @rdpierce turbocharger wouldn't be a good fit as generally no output shaft and single stage impeller. As for pump expense I'd be using something like a used TPH-60 so just a couple/few hundred bucks. 18-Jul-20 06:49 PM Giving more thought, though, a turbocharger may do well for converting the high pressure/temp steam into a more conductive lower pressure/temp high velocity air stream for harvesting with a multistage turbine 18-Jul-20 06:53 PM Supercharger has shaft 18-Jul-20 06:53 PM @GigaSquirrel so the plasma /would/ touch the glass/chamber unless you had magnetic confinement, right? But I guess you're saying even if it does touch, basically it's density is so low that the chamber is such an effective heatsink that you never get the wall up that hot (for lightbulb-ish power)? 19-Jul-20 12:09 AM Yep! 19-Jul-20 06:05 AM <𝓕ermion#6024> @funranium I’m surprised they trusted an undergrad with HF 19-Jul-20 07:08 AM I've heard of mat sci programs that have undergrads use it to etch in upper level labs 19-Jul-20 07:08 AM Which sounds really, really dumb to me personally 19-Jul-20 07:22 AM Turbopumps blades are really not made to work in fluid regimes (hence molecular). I would go with a car turbo too. Turbines are expensive. 19-Jul-20 11:07 AM Yeah, turbopumps are designed to spin happily at really high rpm with almost no power and only significant centrifugal forces. But with steam you'll get a significant axial load, which the bearings are not designed to take. And the vibrations will likely snap the blades. Turbopump blades also have pretty small pitch because they are meant to match the molecular velocity of gas, not the speed of sound in the gas, so the axial loads will be even more significant in this case, and it's going the wrong direction if you inject steam in the backing port. 19-Jul-20 11:07 AM What makes you think the turbulence would not be difficult to mitigate? Are you already prepared to make your own rotors? 19-Jul-20 11:07 AM It'd be very inefficient if you use the original blades, even if they work at these high load, low rpm operation 19-Jul-20 12:47 PM If you've got machining abilities, it stands to reason that you may get a better result by constructing something modeled after a real steam turbine. 19-Jul-20 12:47 PM Or adapting a turbocharger or supercharger might be easier than a turbomolecular pump. 19-Jul-20 02:23 PM https://www.youtube.com/watch?v=SrNVLCHrJtY 19-Jul-20 02:47 PM I used HF in undergrad in our microelectronics program lab 19-Jul-20 08:08 PM I love that glass pump and want one 19-Jul-20 08:08 PM I wonder if there is any way to design one in a not terrible way to be used as a space heater 19-Jul-20 10:25 PM You can buy the glass pump for 490usd on amazon https://www.amazon.com/Vacuum-Diffusion-L-2210-Three-stage-Four-stage/dp/B07MJ2RQ44/ 19-Jul-20 10:54 PM @𝓕ermion Being a physics student working another department gets you a lot of latitude they don't give their own students. They also expect you to be a miracle worker and to be able pick up the entire body of knowledge of their field in short order. I mean, I did but only for highly specialized igneous petrology and mass spec applications. I wondered why visitors kept calling me Dr. Broughton until I realized that absolutely everyone else working in this lab was a postdoc or faculty... and the lab manager didn't trust them as much as me. 19-Jul-20 11:03 PM I get called doctor / prof by email not infrequently 19-Jul-20 11:11 PM As do I, but I'm also 20+ years older now. 19-Jul-20 11:27 PM tmp as a steamturbine generator thing? 19-Jul-20 11:27 PM to power another tmp for vacuum purpose? 19-Jul-20 11:44 PM Recently I was doing basic research about how difficult would it be to build our own turbocirculator for cryogenic helium loop. Outcome is clear - turbomachinery is quite complicated. Almost everything is efficient only in narrow band of parameters, if you want to build something small (for small mass flows) rotation speed must be insane, also design of compressor wheel is more like magic. So I would suggest playing with automotive turbo (as this will be quite cheap if you fail) or focusing on other design like roots/lysholm pump. 20-Jul-20 09:48 AM Thanks for the link! Why do the three vs four stage pumps have such different cooling systems? 20-Jul-20 09:48 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-1FC11.png 20-Jul-20 06:02 PM It would be a really neat ornament and a nice space heater in the winter if you actually use it 20-Jul-20 06:02 PM Knowing my luck with moving stuff, this will certainly not survive my future relocation(s) 20-Jul-20 06:02 PM This is most certainly NOT how you should move an electron microscope and vacuum pumps 20-Jul-20 06:02 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200714_113916-24A7D.jpg 20-Jul-20 06:02 PM I wrapped the column in thick packing blankets, wrapped it in 5 layers of shrink wrap, tapes it all over and provided more padding in the critical points. Then I paid $300 extra for careful handling of both the SEM and the vacuum pumps 20-Jul-20 06:02 PM Specifically, NOT to stack things on top of them 20-Jul-20 06:02 PM All written in black and white on the moving contract 20-Jul-20 06:02 PM And... The movers got my delivery address wrong, was 3 weeks late, and apparently had absolutely no idea what they are moving and what precaution to take... 20-Jul-20 06:02 PM He thought putting a bucket on top of the SEM column would be good enough to justify stacking 5 other boxes (not even mine) on top of it 20-Jul-20 06:02 PM Time to go through the damage claims process... What a headache this has been 20-Jul-20 08:07 PM <𝓕ermion#6024> does anyone know of a nice time-series/log explorer control or piece of software? 20-Jul-20 08:07 PM <𝓕ermion#6024> I just wanna zoom or select a date range or whatever 20-Jul-20 08:07 PM <𝓕ermion#6024> I just wanna make something SCADA-ish and be able to look at temperature/pressure data as it comes in or browse the history or whatever 20-Jul-20 08:07 PM <𝓕ermion#6024> some control/piece of software like this must exist 20-Jul-20 08:34 PM There's a reason everything new comes in wooden crates with a ton of the expanding foam or milled foam. 20-Jul-20 08:34 PM also... Labview? 20-Jul-20 08:47 PM <𝓕ermion#6024> labview doesn't really like... let you explore the history of a very long log 20-Jul-20 08:47 PM <𝓕ermion#6024> like maybe we suppose you're logging pressure data once a second for a week 20-Jul-20 09:27 PM EPICS with a data archiver? 20-Jul-20 09:34 PM <𝓕ermion#6024> what's EPICS? 20-Jul-20 09:34 PM <𝓕ermion#6024> ah this thing from argonne 20-Jul-20 09:44 PM What? Labview can do that. Just write to disk with timestamps and change fidelity as data ages.... the only issue I see is you have to decide what you want and then program it, instead of lucking into a non-ideal but good-enough solution already made 20-Jul-20 09:48 PM <𝓕ermion#6024> yeah but what about exploring the data? 20-Jul-20 09:48 PM <𝓕ermion#6024> I guess make another VI for that? 20-Jul-20 09:52 PM So in my system instead of a big expensive PLC 20-Jul-20 09:52 PM I have a laptop that’s not networked running Labview and am using a serial to USB adapter + a null modem cable + a serial port on my networked computer 20-Jul-20 09:52 PM To control gate valves / interlocks / turbos and read gauges 20-Jul-20 09:53 PM <𝓕ermion#6024> hmm that's quite nice 20-Jul-20 09:54 PM A proper PLC is nicer and when you have $100,000s of equipment the $10,000 or so it costs to set one up is probably worth it... but I don’t like arguing with PI about this stuff 20-Jul-20 09:54 PM I still have to figure out exactly how I want to coarsify the data 20-Jul-20 09:57 PM <𝓕ermion#6024> yeah... that's more or less what I'm up against now 20-Jul-20 09:57 PM (My inspiration is how time machine works on OS X) 20-Jul-20 09:57 PM I think in general just thinking how compression algorithms work makes sense 20-Jul-20 09:57 PM You want more data when there’s more changes, etc. 20-Jul-20 09:57 PM So long as you use time stamps, it’s all good. 20-Jul-20 09:58 PM <𝓕ermion#6024> honestly I'm less concerned with how to store the data and more like... all the work involved to make it conveniently browsable and available 20-Jul-20 09:58 PM <𝓕ermion#6024> I'd much rather find some ready-made gui thing than cobble together some rinky dink matplotlib thing 20-Jul-20 09:58 PM <𝓕ermion#6024> I can always throw more hard drives at the problem 20-Jul-20 09:59 PM Reading large text files is slow though 20-Jul-20 09:59 PM That’s my purpose in compression / reducing data from 2Hz logs 20-Jul-20 10:00 PM <𝓕ermion#6024> ohh sure... 20-Jul-20 10:02 PM Just store an N-degree polynomial for however many data points you have 20-Jul-20 10:02 PM And open in wolframalpha 20-Jul-20 10:03 PM <𝓕ermion#6024> of course 20-Jul-20 10:05 PM I know one group that has a background python script just uploading PDFs to a shared Dropbox 20-Jul-20 10:06 PM <𝓕ermion#6024> ah yes 20-Jul-20 10:06 PM Constant 7 days of data @ 1Hz 20-Jul-20 10:06 PM <𝓕ermion#6024> the physicist solution. 20-Jul-20 10:06 PM <𝓕ermion#6024> the extremely physicist solution 20-Jul-20 10:06 PM Actually they’re in the department of chemistry!!!! 20-Jul-20 10:06 PM <𝓕ermion#6024> close enough 20-Jul-20 10:07 PM You could also just get a paper plotter 20-Jul-20 10:07 PM Those things are cool 20-Jul-20 10:07 PM <𝓕ermion#6024> wouldn't mind. 20-Jul-20 11:01 PM <𝓕ermion#6024> I think I will probably try grafana and graphite. 20-Jul-20 11:01 PM depending on the nature of your data you may be able to do something interesting with something like influxdb & grafana for collecting & browsing time series metrics 20-Jul-20 11:01 PM .. oh yeah lol 20-Jul-20 11:01 PM graphite works too but i haven't used it in many years 20-Jul-20 11:02 PM <𝓕ermion#6024> yeah there's just still something that feels a bit squishy about the whole ecosystem of sysops tools 20-Jul-20 11:02 PM <𝓕ermion#6024> not sure what it is 20-Jul-20 11:02 PM it's pretty squishy 20-Jul-20 11:03 PM <𝓕ermion#6024> glad you know what I mean 20-Jul-20 11:04 PM people gave up on rigid standardizations of stuff at some point and started building exclusively on and around web tech & a large chunk of all of that has gone weirdly sour since, BUT 20-Jul-20 11:05 PM <𝓕ermion#6024> I think when I said squishy I more meant it looks kinda... unscientific in a way 20-Jul-20 11:05 PM i do use influx + grafana for collecting time series data from sensors, and it works even better than my sensors generally do. one potential concern could be, like, data import/export for backups & etc, though 20-Jul-20 11:06 PM <𝓕ermion#6024> like everything is javascript, nothing is "ugly" enough, lol 20-Jul-20 11:06 PM they're just tools 20-Jul-20 11:06 PM <𝓕ermion#6024> well then, the question is... do you find it reliable? 20-Jul-20 11:06 PM <𝓕ermion#6024> do you find it makes the data accessible? 20-Jul-20 11:08 PM i do, but my use case is not necessarily your use case. the software itself is pretty solid & i haven't had any issues with crashes or data corruption afaict 20-Jul-20 11:09 PM <𝓕ermion#6024> we're developing an infrastructure for this... the data will be sent to another server where it'll go into a postgresql database. That's all fine. 20-Jul-20 11:09 PM it's designed to be the backbone of infrastructure monitoring systems and is widely used as such so it's fairly solid stuff in the general sense 20-Jul-20 11:09 PM yeah 20-Jul-20 11:09 PM <𝓕ermion#6024> the thing I'm most concerned with is just having a raspberry pi with a screen and some buttons and plots on it 20-Jul-20 11:09 PM <𝓕ermion#6024> and being able to zoom into the plots, choose appropriate granularity for the plots, etc. 20-Jul-20 11:10 PM definitely try replaying your data into influxdb; it has sort of a query language unto itself but it's not one you would want to do much complex ETL stuff in. then aim grafana into it and use it to hunt around in histograms & etc 20-Jul-20 11:10 PM it's very easy to set up to play around with 20-Jul-20 11:11 PM <𝓕ermion#6024> okay perfect. 20-Jul-20 11:12 PM i'm very likely going to try aiming EPICS into my install on short order and i expect to incite some delightfully silly load testing in the process :D 20-Jul-20 11:40 PM <𝓕ermion#6024> has anyone encountered a variable speed roots pump? 20-Jul-20 11:48 PM <𝓕ermion#6024> and also, does anyone have a favorite brand of inverted Magnetron gauge? 21-Jul-20 12:15 AM and also, does anyone have a favorite brand of inverted Magnetron gauge? @𝓕ermion We like to use Pfeiffer PKR251 (combined pirani&cold catode) - they are easilly serviceable, quite accurate, fast, not that expensive, with 0-10V output. They also make pure-cold catode, it is called IKR251 I think. And there are loads of them on ebay for $100 - $150. 21-Jul-20 08:03 AM I don’t like the MKS 500 cold cathodes we got. 21-Jul-20 08:41 AM <𝓕ermion#6024> what's the difference between the balzers and inficon and pfeiffer gauges? 21-Jul-20 08:41 AM <𝓕ermion#6024> are they rebadged or knockoffs? 21-Jul-20 08:45 AM what's the difference between the balzers and inficon and pfeiffer gauges? @𝓕ermion https://en.wikipedia.org/wiki/INFICON#/media/File:INFICON_Timeline_History.JPG I would think only the badge is different, but I have worked only with Pfeiffer ones... 21-Jul-20 08:46 AM <𝓕ermion#6024> huh ok. 21-Jul-20 09:42 AM I've worked with Edwards. 21-Jul-20 09:42 AM They have gauges that require separate controllers, and their "AIM" gauges that use an RJ-45 jack for power and data. These can use separate controller/displays which will convert voltage to pressure units and may offer serial bus output, or they can be used directly. 21-Jul-20 06:43 PM I like the Edwards inverted magnetron gauges 21-Jul-20 06:43 PM I've got one with an unstable reading though, it's due to some problem in the gauge body, not in the sensor head. Still usable, but won't put it on anything critical 21-Jul-20 07:48 PM Joined the server. 21-Jul-20 08:08 PM hello! 21-Jul-20 09:59 PM welcome! 21-Jul-20 10:16 PM I had an Edwards gauge that gave wonky readings in my old SEM. 21-Jul-20 10:16 PM Turns out it had sputtered a resistive layer on itself, was filthy, and was giving readings at waaay too low of a pressure. 21-Jul-20 10:16 PM The chamber had an awful leak from an air admit solenoid but the magnetron masked it. 21-Jul-20 10:16 PM It would bounce.between 1e-5 and 1e-4 torr. Cleaning the magnetron gauge resulted in the gauge reading 1e-4 torr consistently which was the real chamber pressure after all. 21-Jul-20 10:16 PM Take care cleaning them. 21-Jul-20 10:16 PM I believe some variants of the Edwards gauge contain a hot nickel isotope to help strike an arc. 22-Jul-20 10:33 AM Until my machine shop finished with something, I'm stuck using an old leak valve from a drawer. The stop seems to be set wrong, because it leaks hugely when there's more than 1/3 of an atmosphere backing it... specced for 500 psi 22-Jul-20 03:12 PM This is dumb but I'm gonna ask anyways. When I get the turbo pump I can't just test it by turning it on right. So would I have to put something over the input and connect a forepump to the output? What's the general protocol? I'm generally trying to figure out what valves, fittings, and tubing I might need. 22-Jul-20 03:23 PM what pump? 22-Jul-20 03:28 PM I just won em in auction the other day lemme grab the exact numbers 22-Jul-20 03:29 PM I would put a pressure sensor too if possible 22-Jul-20 03:29 PM also better if you have a venting valve an insulation valve 22-Jul-20 03:30 PM You can turn it on for a few seconds in air to make sure it spins & isn't grinding against its bearings, but no more than that. Find a datasheet for your pump and it'll tell you what kinda backing vacuum pressure requirements it has, and then you could blank off the inlet (ideally with a gauge) and get an idea of how it performs 22-Jul-20 03:30 PM yeah, more valves + gauges always helps 22-Jul-20 03:31 PM Pfeiffer Balzers TPU 330 - this is the turbo I won two Gast DAA P501-GB diaphragm pumps as well 22-Jul-20 03:31 PM yeah ill find those datasheets as well 1 sec 22-Jul-20 03:31 PM oh lol it's one of those weird ones 22-Jul-20 03:31 PM nice 22-Jul-20 03:32 PM yeah its a government surplus auction so i just jumped on it 22-Jul-20 03:32 PM was like 60-80 bucks and they say its in good condition 22-Jul-20 03:32 PM you have the controler with them? 22-Jul-20 03:33 PM yeah i also won two of the turbo controllers and lucky me its compatible with the turbo 22-Jul-20 03:33 PM wow just googled them they are weird 22-Jul-20 03:34 PM yeah its not what im used to when i look up a turbo lol 22-Jul-20 03:34 PM the controllers are Pfeiffer Balzers TCP 380 22-Jul-20 03:35 PM Just asking because it was a pain once to source controllers for turbo we got for free out of some industrial refuse 22-Jul-20 03:36 PM but yeah ill look at #resources and stuff but if u have any suggestions for where to source like tubes, guages and that kinda stuff would be greatly appreciated 22-Jul-20 03:36 PM yeah i won the controllers and thought worst case id sell them 22-Jul-20 03:36 PM but then won a turbo as well 22-Jul-20 03:36 PM We have a 510 22-Jul-20 03:36 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-AD13D.jpg 22-Jul-20 03:36 PM And a couple controllers, currently using a TCP380! 22-Jul-20 03:37 PM epic so ill def have to ask u some tips 22-Jul-20 03:37 PM tho idk if the cord is included for powering it which kinda sucks if it isnt 22-Jul-20 03:38 PM it has been sitting there forever and the only button I've pressed on the controller the on/off button 22-Jul-20 03:38 PM ill ask them tho they wont have any use for that cord anyways 22-Jul-20 03:38 PM these are the diaphragm pumps 22-Jul-20 03:38 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-B5E18.png 22-Jul-20 03:38 PM Oh, yeah if you need me to measure the pin connections on the cord to make your own just let me know, since it's probably the same 22-Jul-20 03:39 PM yeah thats another thing i was gonna ask if it was possible to diy a cord 22-Jul-20 03:39 PM ill def hit u up for that info if needed thanks! 22-Jul-20 03:39 PM @charizardrekt ebay is a great place to spend literally all your money on acccessories :D the MKS 901p makes a good cheap gauge for measuring atmospheric pressure to just before the 'high vacuum' threshold, i use one of those in my foreline & might get another one soon 22-Jul-20 03:39 PM this is the turbo btw 22-Jul-20 03:39 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-0C834.png 22-Jul-20 03:40 PM oh cute yours comes with the red cover too 22-Jul-20 03:40 PM aside from that just random KF odds and ends can be had cheaply if you'rr patient (or less cheaply if you're not) 22-Jul-20 03:40 PM have to drive 3 hrs to go pick it up 22-Jul-20 03:40 PM but worth it 22-Jul-20 03:40 PM what is the red cover? i've wondered that for a while 22-Jul-20 03:40 PM wasn't sure if it was a heating band or smth 22-Jul-20 03:41 PM i dont think people bidding on this auction rlly know what they were doing lol 22-Jul-20 03:41 PM no way i should have gotten these for the price i got em for 22-Jul-20 03:42 PM hopefully they're in good condition 22-Jul-20 03:43 PM its coming from a well known accelerator facility here and they have markings of condition so based on that should be ok 22-Jul-20 03:43 PM if it doesnt work/has issues they say poor 22-Jul-20 03:43 PM this said FAIR condition and doesnt need any repairs which it says for other stuff if needed 22-Jul-20 03:43 PM so fingers crossed 22-Jul-20 03:45 PM an accelerator facility sounds more like the type to keep stuff so long as there's any semblance of it still doing anything useful 22-Jul-20 03:46 PM tru but this seems to be more like clearing out because they are forced to 22-Jul-20 03:46 PM lack of space and stuff 22-Jul-20 03:46 PM they are selling a lot of stuff that still works well 22-Jul-20 03:46 PM government surplus ¯\_(ツ)_/¯ 22-Jul-20 04:02 PM so i guess first step is to see whether these diaphragms can act as a forepump for the turbo based on the data sheets 22-Jul-20 04:02 PM well first first step would be picking everything up and making sure they work lol 22-Jul-20 04:17 PM forgot to mention i also won a flow meter idk if that would be helpful but maybe if im introducing gas or something in the future? 22-Jul-20 05:31 PM I have a dumb newbie question. I've picked up an old SEM on eBay (the JEOL JSM-5400), it's been described as "having recently worked" but upon arrival it had a lot of problems. I'm still figuring out most of them, but one particular thing is that the roughing pump seems to be low on oil. Here's an eBay image of an identical pump: https://i.ebayimg.com/images/g/pgUAAOSwOJVelC-k/s-l1600.jpg, https://www.ebay.com/itm/Jeol-LTD-Rp-100G-Rotary-Pump-Motor-Power-300W/124152099550 (they have much nicer pictures than mine) I'm trying to understand where to put oil in it - there's what looks like a drain plug at the bottom, and the air inlet and outlet (which is where the mushroom-shaped cap is in the picture.) There's no obvious fill cap. Does anyone happen to know these? 22-Jul-20 05:50 PM does the air outlet unscrew? could be as simple as that... 22-Jul-20 05:50 PM definitely do not force anything! 22-Jul-20 05:55 PM @vovchik I've got a pump like that 22-Jul-20 05:55 PM imgur.com/a/e9WyAm2 https://imgur.com/a/e9WyAm2 22-Jul-20 05:55 PM Duniway stockroom said about those pics 22-Jul-20 05:55 PM "I forget the model number, but it’s a Hitachi belt drive pump. Any of our hydrocarbon based oils will work. My recommendation would be the MPO-200-1 @ $50. I have the front shaft seal for that pump if you ever need it. " 22-Jul-20 06:00 PM it wants so hard for that one photo to be the thumbnail for some reason but if you click through you can see the full gallery of photos 22-Jul-20 06:01 PM Oh, I was clicking here on my phone and it was just a single image 22-Jul-20 06:01 PM Even tried downloading it to see if my browser would open 22-Jul-20 06:15 PM I am still talking to the seller over email but his replies are very short and odd, some of them are clearly wrong - but he recommended Edwards Ultragrade 19 oil 22-Jul-20 06:15 PM also the start capacitor on the motor was ripped off (with loose wires where it used to be) and the motor bearings were destroyed, It took me a while just to get the motor to spin 22-Jul-20 06:15 PM the air outlet unscrews easily, the inlet does not, and the plate on top where both of these are also doesn't come off easily 22-Jul-20 06:15 PM so I guess I'm going to put the oil in there and see 22-Jul-20 06:17 PM who tf rips off a capacitor lol 22-Jul-20 06:17 PM weird 22-Jul-20 06:17 PM I have a strong suspicion this SEM was a parts donor for another one, and the seller claims it was not 22-Jul-20 06:17 PM that would make sense 22-Jul-20 06:18 PM some of the connectors on the high voltage supply (which is immersed in transformer oil) broke off and fell down into the tank 22-Jul-20 06:18 PM I had to machine my own replacements, not sure if they work 22-Jul-20 06:18 PM but the worst part about it 22-Jul-20 06:18 PM there appears to have been a mouse nest in the computer/electronics part in the console 22-Jul-20 06:19 PM yikes 22-Jul-20 06:19 PM it was full of pink insulation foam (that the mice stuffed in there, I think?) and there were chewed wires and other, umm, indicators of their activities 22-Jul-20 06:19 PM I cleaned it all - I made the mistake of trusting the seller and trying to power it up without opening that part, and I think some of the chewed wires shorted and at least one chip was visibly damaged/burned. I replaced that one (and have spares for everything on that board) - I just finished putting it back together and it's showing the same symptoms as before 22-Jul-20 06:19 PM there is a "check/select" button that shows different voltages and currents - and it's displaying a blank space where the numbers should be. I believe this means it can't read the voltage with the ADC. 22-Jul-20 06:19 PM the popped chip was an analog mux, part of the frontend for the ADC - the ADC itself may be fried too, I'm going to scope it and find out 22-Jul-20 06:19 PM but that is another problem I'll have to figure out, and I think I know how. I did need help with replacing the oil in the pump 22-Jul-20 06:19 PM @nmz787 that looks very much like the internals of a similar SEM. How is the pump mounted to it? Mine came removed for transportation; the motor and pump are bolted to a common base plate, and there are looong hex standoffs coming down from it, bolted to the floor of the machine. On top of the base plate, there are hooks - and matching hooks on the SEM frame above it - and I have a set of springs that fit there. I'm wondering, is it supposed to be bolted down with the standoffs and pulled up by the springs at the same time? Or are the standoffs only for transportation, and normally it's just suspended by the springs? 22-Jul-20 06:19 PM the springs are probably to reduce vibration, and in that case it makes sense to not bolt it down 22-Jul-20 06:19 PM maybe this explains it better. The springs can be stretched out and attached to the hooks on the pump base plate, it's really hard to do and they will be under a lot of tension. 22-Jul-20 06:19 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_6290-91E87.JPG 22-Jul-20 07:21 PM my vote's on it being like that for transportation, yeah. looks like it would hang on the springs. depending on how heavy that pump assembly is it seems like it'd make sense to unbolt it, then lift it up and onto/into the springs 22-Jul-20 07:21 PM interesting design 23-Jul-20 09:32 AM not sure how it would evenly fight the tension on the belt, you'd need like much heavier springs in the front than the back but yea that is weird 23-Jul-20 03:00 PM What's the proper tubing I should look for vacuum stuff. I assume regular PVC won't cut it? I saw like different stuff online but wasn't sure 23-Jul-20 03:17 PM PVC is fine for rough vacuum 23-Jul-20 03:17 PM It does contribute some gas load, as does anything, but in general it's fine. 23-Jul-20 03:28 PM Oh ok cool. What point would it become a problem? Like if I want to work with the turbo. 23-Jul-20 03:30 PM So pumps have quite a few parameters, pumping speed, compression ratio, ultimate pressure... 23-Jul-20 03:30 PM If your forevacuum pressure is limited by the forevacuum pumping speed, rather than compression ratio or ultimate pressure, you want to reduce the forevacuum gas load and so PVC is a bad choice 23-Jul-20 03:30 PM also if you're going to be baking your system, PVC is a bad choice 23-Jul-20 03:31 PM Tru lol 23-Jul-20 03:31 PM I'll look into the specific pump parameters more 24-Jul-20 05:00 AM @charizardrekt https://www.amazon.com/gp/aw/d/B01N4B9JFS 24-Jul-20 05:00 AM I used some of that for a rough vacuum system, got down to around 500mTorr at best, but I think my system was leaky after that hose :p 24-Jul-20 05:00 AM Question on IGPs... How long will they last (lifespan) pumping a small chamber after the turbo has been turned off? This is for my ion gun, which has isolation valves to keep it relatively sealed off. 24-Jul-20 05:00 AM Been using the IGP exclusively for a good month or two, and a month or two before that as well. Just since I haven't been using the system and wanted to keep the gun "dry". 24-Jul-20 05:00 AM (and wanted to save power and reduce thermal heat load in my garage by turning off the rough and turbo pumps) 24-Jul-20 05:00 AM @vovchik hmm I don't think mine has springs, it's just sitting on the bottom of the enclosure, I can check if it seems like it had them at one point... 24-Jul-20 07:02 AM That flexible pvc will hit 5E-3 if you pump it well. I’m using 4” pvc sewer pipe and do too 24-Jul-20 03:39 PM <𝓕ermion#6024> @funranium have you seen NileRed's chromyl chloride cleanup video? 24-Jul-20 03:46 PM I can't say that I have. Don't watch NileRed much. 24-Jul-20 07:24 PM <𝓕ermion#6024> @funranium I'm curious if you find this protocol as insane as I do: At a certain university, grad students are required to ride in the elevator with nitrogen and helium dewars to discourage undergrads from entering 24-Jul-20 07:24 PM ...what 24-Jul-20 07:24 PM No 24-Jul-20 07:24 PM please no 24-Jul-20 07:25 PM <𝓕ermion#6024> at most schools that I know of, you put a chain across the front and meet the dewar at the floor you wanna bring it to 24-Jul-20 07:25 PM <𝓕ermion#6024> okay mez I'm glad you're having the same reaction I did. 24-Jul-20 07:25 PM <𝓕ermion#6024> because to me this is a pretty clear statement that they don't care about their grad students. 24-Jul-20 07:25 PM It sounds like a great way to kill grad students to me 24-Jul-20 07:25 PM Especially with how shoddy some of those pressure relief valves on LN2 tanks are 24-Jul-20 07:25 PM Have had more than a few freeze open 24-Jul-20 07:26 PM <𝓕ermion#6024> I was told "Don't worry about it... the elevator has a little fan on it" 24-Jul-20 07:26 PM And if you're stuck in an elevator with it when that happens... 24-Jul-20 07:26 PM <𝓕ermion#6024> and I was like "yes I totally trust that little fan." 24-Jul-20 07:26 PM <𝓕ermion#6024> "seems fine" 24-Jul-20 07:27 PM That is a general NOPENOPENOPE Thous Shalt Not pretty much around the world. 24-Jul-20 07:27 PM <𝓕ermion#6024> right? 24-Jul-20 07:27 PM Can you hold your breath until the doors open? 24-Jul-20 07:27 PM Of course, also at a certain university, physics students managed to throw a Taylor-Wharton 160L high pressure dewar down the staircase. 24-Jul-20 07:28 PM <𝓕ermion#6024> I know the story... 24-Jul-20 07:28 PM Yes. A certain university. 24-Jul-20 07:28 PM I know someone who was transporting a small dewar in their car and it tipped over in their back seat 24-Jul-20 07:28 PM I feel like I've actually heard of the university that tells students to be in the elevator with the dewar now that you mention it though... 24-Jul-20 07:29 PM The dent in the wall in the staircase was never repaired for training purpose. To remind physics students "You aren't nearly as smart as you think you are." 24-Jul-20 07:29 PM lol 24-Jul-20 07:32 PM my elevator doesn't have a vent. 24-Jul-20 07:32 PM when I told a specific someone that we shouldn't ride with the dewar we were filling 24-Jul-20 07:32 PM they told me 24-Jul-20 07:32 PM in soviet union I flew in plane with big tank of liquid nitrogen, it was fine 24-Jul-20 07:33 PM I mean throwing a dewar down the stairs seems like a common sense thing to not do 24-Jul-20 07:33 PM Don't underestimate the laziness of physicists 24-Jul-20 07:34 PM this is why I did chem 24-Jul-20 07:34 PM Though admittingly throwing a 400 lb tank down a flight of stairs doesn't sound easy in its own right 24-Jul-20 07:34 PM They were told they couldn't take the dewar in the elevator. So they headed for the stairs... 24-Jul-20 07:34 PM this is why I did chem has anyone else noticed a glaring difference between physics and chem in likelyhood of safety practices actually being observed or is it just my department 24-Jul-20 07:35 PM There was a dewar on the auction I won the pumps from 24-Jul-20 07:35 PM I didnt go for it lol 24-Jul-20 07:35 PM Reading this story, this was even dumber than I thought 24-Jul-20 07:35 PM You tried to ROLL IT down the stairs? 24-Jul-20 07:35 PM Meh chem people tend to be safer because they are scared 24-Jul-20 07:35 PM Literally everything can hurt u in someway 24-Jul-20 07:37 PM That's probably because a lot of chem can't be done remotely safely without proper creedence to safety. Though as I'm sure funranium can tell you, we're not all saints in chem safety wise. 24-Jul-20 07:37 PM And honestly chem Es kick our tails there too 24-Jul-20 07:37 PM Have heard of a few people trying to clean up large amounts of flammables in very stupid ways... 24-Jul-20 07:37 PM speaking of safety 24-Jul-20 07:37 PM my 50 year old HV PSU sparks when I change the voltage, should I be worried? 24-Jul-20 07:38 PM Yeah chem e sounds hard af 24-Jul-20 07:38 PM Though at least that dewar story ended well. That could have been a lot worse than a scared undergrad and some dents 24-Jul-20 07:39 PM Chem is... okay. MCB I would like to collectively flush down the toilet. 24-Jul-20 07:39 PM Biochem gang 24-Jul-20 07:39 PM MCB? 24-Jul-20 07:39 PM oh wait, biochem, molecular bio? 24-Jul-20 07:40 PM Molecular and cell bio probably 24-Jul-20 07:40 PM Yes 24-Jul-20 07:40 PM Rood 24-Jul-20 07:40 PM Lab I work in isn't cell bio tho technically 24-Jul-20 07:41 PM For people who work with things just as bad as the Chem, they suuuure don't seem to have much sense of self-preservation. 24-Jul-20 07:47 PM <𝓕ermion#6024> i n t e r c a l a t o r s 24-Jul-20 11:59 PM my 50 year old HV PSU sparks when I change the voltage, should I be worried? @idmb depends where the sparks are 25-Jul-20 12:00 AM make ur own HV PSU yeet 25-Jul-20 02:15 AM scratchy potentiometer? ancient variac? 25-Jul-20 02:15 AM get a voltage divider probe on it and see if the output voltage is bouncing all over the place 25-Jul-20 06:26 AM Given how mutagenic stuff in MCB is... I wonder if there’s a certain fatalism. 25-Jul-20 06:26 AM I remember hearing about how they have to be careful that nobody in the lab where they’re working with an immortalized cell line contributed the cells that were immortalized. Otherwise it’s insta-cancer personally tailored for them. 25-Jul-20 07:25 AM Ok that’s a terrifying thought 25-Jul-20 08:11 AM immortalized...on the wall. forgotten...on the floor. 25-Jul-20 08:14 AM My chamber is teasing me 25-Jul-20 08:14 AM ultimate pressure right now is 1.05E-9 torr, has been dropping about 0.02E-9 per day 25-Jul-20 08:34 AM nice! 25-Jul-20 08:40 AM Dang that's low 25-Jul-20 08:55 AM Leybold 250i backed by edwards iGX600L, it better get that low lol. The (new) chamber itself got baked to 250C, but it has a lot of machined components in it that were only sonicated in acetone and heated to 50C. Including some aluminum and Macor. Some poorly-designed gaps causing virtual leaks, too. 25-Jul-20 11:19 AM Eh, re immortalized cells and being careful, it's really not too much "care" 25-Jul-20 11:19 AM I mean, I worked with them a ton in undergrad 25-Jul-20 11:20 AM Those aren't ur own cells tho 25-Jul-20 11:20 AM Random immortalized cells are nbd tho people use em in labs all the time 25-Jul-20 11:30 AM Idk, I guess I misunderstood @rdpierce comment. I reread it, and still can't parse 25-Jul-20 11:42 AM Holy. The leybold 1000C can handle a steady-state inlet pressure of 0.01 mbar 25-Jul-20 02:53 PM As I understand it, immortalized cell lines will not die off on their own, like normal cells would. 25-Jul-20 02:53 PM If immortalized cells get into your body, and they are someone else’s cells, your immune system will probably make short work of getting rid of them. 25-Jul-20 02:53 PM If they are your own cells, your immune system won’t realize they’re foreign and attack them. 25-Jul-20 02:53 PM And they’ll grow and multiple and won’t die, e.g. cancer. 25-Jul-20 02:53 PM I know very little about MCB, this was learned from a grad student dumbing things down for me to understand it. 25-Jul-20 03:30 PM Immortalized cells definitely die if they aren't fed 25-Jul-20 03:30 PM Autoimmune diseases and cancer are definitely possible outcomes of getting autogenous immortalized cells back into your system 26-Jul-20 12:03 PM any suggestions on types/source of glass tubes/electrodes to make various gas-filled/vacuum tubes? is it different glass for different types of devices, eg soda lime vs boro? 26-Jul-20 12:25 PM Diy vacuum tubes? Cool 26-Jul-20 12:25 PM Think they just use borosilicate for most vacuum tubes 26-Jul-20 12:25 PM IDK about gas filled stuff tho 26-Jul-20 12:25 PM U mean like thyratrons? 26-Jul-20 12:46 PM atm i'd like to make a phototube (photomultiplier without the amplification) 26-Jul-20 01:50 PM @samy @Charles had a bunch 26-Jul-20 01:54 PM Generally the choice is made based upon expected operating temperature. Harder glasses are generally better for higher temperatures. PMT’s are a bit different since essentially they work at room temperature. The class composition has more to do with the passdand or filtering of the wavelength of light you are interested in. Normal optical range typically used lime glass. UV used stuff more on the Quarts end of the glass spectrum and there are special ones for filtering the various light ranges. 26-Jul-20 02:21 PM i see - I'm sure some stuff will be higher temp but i'm guessing those are harder to work with, more likely for vacuum system stuff 27-Jul-20 07:48 AM Actually harder glasses can be easier to work with due to their higher resistance to thermal shock. Working temps are higher and you require proper eye protection but it’s not a problem when you have the appropriate torches and tips. 27-Jul-20 11:04 AM ahh 27-Jul-20 12:47 PM https://cdn.discordapp.com/attachments/664551114091528225/737369185943945316/6dcZkT_UsHh0Xg7XfF0e3p6m4fY60g-GPHyx-XghET17yFWn0ezKoKR5qsAQql2UL9HjRwDI9bHJAu-UbJiOjtHZjJHbvNVGK5Ek.png variac acquired 27-Jul-20 04:14 PM oh i have that same variac, 'cept the 1kVA version. it certainly does the thing 27-Jul-20 04:14 PM i've aerosolized the fuse in it at least once from accidental switch bounce with the k'nob set to a low voltage & with nothing plugged in it, so.. have some spares around :D 27-Jul-20 07:28 PM yah I was gonna go for something like that but then this popped up and I dropped an offer and got it for a really good price. This will be pretty helpful for a lot of electronics stuff 27-Jul-20 07:28 PM Especially toob stuff 27-Jul-20 08:14 PM Variacs are notorious for blowing fuses from switching them on at non zero voltage AC. When I was younger and they were far more common I made up designs for soft starts for them but the mosfets to do it with were so expensive then. Now the mosfets are cheap but the variacs are expensive and most shops don’t even have them anymore. They are so handy and efficient. 27-Jul-20 09:23 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200727_212251-F8786.jpg 27-Jul-20 09:23 PM I've never seen a fuse blow so satisfyingly thoroughly before 27-Jul-20 09:23 PM (and, like, stay intact) 27-Jul-20 09:24 PM lmao 28-Jul-20 02:55 AM I've never seen a fuse blow so satisfyingly thoroughly before @qualia Thats incredile! Have both fuses remained conductive? I can't tell about the right one 28-Jul-20 07:36 AM At least you can get new fuses. 28-Jul-20 07:36 AM I'm... worried... about my Fialka restoration work. It uses differently sized unobtainium Russian fuses. So I'm trying to be very careful. 28-Jul-20 07:36 AM There's a reason why I'm using a bench power supply that's current limited. 28-Jul-20 07:36 AM It's a bit of a difficult issue because there's a current inrush to get the DC motor to start. 28-Jul-20 07:41 AM just bridge the fuses until you know it works 28-Jul-20 09:17 AM Or make adaptors so you can use common fuses. 28-Jul-20 10:19 AM By some miracle my chamber has hit 5E-10 now and the RGA shows basically no water 28-Jul-20 10:22 AM awesome! 28-Jul-20 10:22 AM how many months of pumping? 28-Jul-20 10:26 AM That's 3 weeks 28-Jul-20 10:26 AM oof 28-Jul-20 10:26 AM thats not continuous right 28-Jul-20 10:27 AM It was previously opened fairly frequently and getting to ~5E-9 within a day or two, then at the end of february it was closed off behind the turbos and vented (through the leaking KF valve) up to around 1 torr before I started pumping it again 3 weeks ago 28-Jul-20 10:27 AM it got baked in september but had been opened many times since then. so the oil and stuff were fine but lots of water 28-Jul-20 10:27 AM And yeah that's continuous, Leybold 250i + iGX 600L 28-Jul-20 10:29 AM i assume those are pretty quiet? 28-Jul-20 10:29 AM If you can call a constant drone at around 60dB quiet 28-Jul-20 10:29 AM The iGX is in a separate room because it's annoyingly loud. 28-Jul-20 10:29 AM It's not that loud, you can talk fairly quietly beside it, but yeesh. 28-Jul-20 10:29 AM The turbopump is quiet, mine isn't watercooled but it just has two quiet CPU fans 28-Jul-20 10:52 AM I wish we ever got to no water 28-Jul-20 10:52 AM Or even water isn't the main contaminant 28-Jul-20 11:08 AM I'm gonna be ToFing mass 76 so 18 won't bother me 28-Jul-20 11:22 AM At that water level it's not going to be a big deal, but creating water complexes on accident in your droplets can be sad 28-Jul-20 11:27 AM that's so unlikely below 1E-8 though? 28-Jul-20 11:32 AM Yeah. Like I said at your levels it's not a worry. 28-Jul-20 11:32 AM That's more something we have to worry about/why we need the cryo pumps 28-Jul-20 11:33 AM Why are your levels above that ? 28-Jul-20 11:33 AM Because KFs can't bake out and it's Georgia 28-Jul-20 11:33 AM We're not super above that 28-Jul-20 11:33 AM But a little bit 28-Jul-20 11:33 AM Anyway, we definitely see noticeable amounts of droplets doped with water 28-Jul-20 11:33 AM Though with the cryo pumps we don't get complexes 28-Jul-20 11:33 AM At least I can't remember any mass channels we attributed to desired product/side product+water 28-Jul-20 11:38 AM If you get a metal seal for your KF, it can bake 28-Jul-20 11:38 AM And even without, it can soft bake 28-Jul-20 11:38 AM But the baking isn't the issue 28-Jul-20 11:38 AM you don't have to bake to hit 1E-9 from water 28-Jul-20 11:38 AM If you're stuck there either your comp ratio + forevac is no good, or you've got something leaking 28-Jul-20 12:52 PM just bridge the fuses until you know it works @GigaSquirrel Heheheh yeah, right. Like the penny in the fuse box trick.... 28-Jul-20 12:53 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/HjqfZZh-717D6.png 28-Jul-20 12:53 PM I'm curious about the cheese. 28-Jul-20 12:53 PM I remember someone who told me you only needed to run one wire in a conduit.... Just use the conduit itself as the neutral. 28-Jul-20 12:53 PM That... was traumatizing to ponder. 28-Jul-20 12:56 PM lol go look at the wiring on old boats 28-Jul-20 01:11 PM I'm curious about the cheese. @idmb with olfactory feedback 28-Jul-20 02:14 PM @rdpierce If you can find what what GOST spec the russian fuses in the Fialka correspond to you might be able top get them from chipdip.ru or some other Russian, Ukrainian or perhaps Belarusian source. 28-Jul-20 02:14 PM Hmmm.... 28-Jul-20 02:14 PM Or just look if chipdip has it 28-Jul-20 02:14 PM as they seem to have a product category "Russian", when using google translate anyway in many sub categories 28-Jul-20 02:14 PM I encountered that when trying to find a source for that nifty PTFE coated wire all Russian electronics hobbyists seem to use. 28-Jul-20 02:27 PM Oh. I have seen way worse then a single wire in a conduit for neutral. In the old days they would run a single high tension line to your place and use the literal earth as the return! 28-Jul-20 03:50 PM Joined the server. 28-Jul-20 04:04 PM Joined the server. 28-Jul-20 04:05 PM #introductions_and_directory 28-Jul-20 04:46 PM <𝓕ermion#6024> anyone know of a source for ten pin seal retainer nuts? 28-Jul-20 04:55 PM @rdpierce can you share more details about these Russian fuses? I have a few friends there who sometimes can find rare parts (but no guarantees of course) 28-Jul-20 04:56 PM Sure, I'll need to pull them out of the machine and look for markings. There are no manuals, no specs except amps listed on the holder, etc. 28-Jul-20 05:01 PM and if you need to look up some other old Russian parts, let me know 28-Jul-20 07:36 PM <𝓕ermion#6024> @vovchik might be looking for some tunnel diodes 28-Jul-20 09:07 PM What do you know about Russian EL displays? 28-Jul-20 09:07 PM @vovchik do you think you could find a datasheet for a ИЭЛ-Р-IX (IEL-R-IX) ? 28-Jul-20 09:07 PM These IEL devices generally tend to be multi-segment displays (7-segment digits, or Cyrillic letters, etc.) and typically take around 220 V 400+ Hz AC. Usually, pin 1 is common, and the others are the segments. However, this specific type is different. A picture of an IEL-R-IX is available here: http://www.oldtriod.ru/radiolampy/indikatory/ix I remember seeing a Russian document describing that part number as a “raster.” The raster type of ELDs is described in this document: http://www.155la3.ru/electroluminescent.htm What I have is definitely oriented in strips. It has 10 pins, so I suppose this could mean 9 distinct segments? Still, the thought of applying that much voltage while guessing what pins do what is troubling. I’m wondering if you have sources that might shed light on this? 28-Jul-20 10:11 PM @rdpierce I know nothing about EL displays, but the second link has a list of references at the end - listing a bunch of old part catalogs from the 1970s. I found a scanned copy of one of them, and what do you know, it has the IEL-R-IX! 28-Jul-20 10:11 PM page 209 of this book: http://radiowiki.ru/index.php?title=%D0%A4%D0%B0%D0%B9%D0%BB:%D0%AD%D0%BB%D0%B5%D0%BC%D0%B5%D0%BD%D1%82%D1%8B_%D0%B8%D0%BD%D0%B4%D0%B8%D0%BA%D0%B0%D1%86%D0%B8%D0%B8._%D0%A1%D0%BF%D1%80%D0%B0%D0%B2%D0%BE%D1%87%D0%BD%D0%B8%D0%BA.djvu 28-Jul-20 10:11 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screen_Shot_2020-07-28_at_10.12.25_PM-63C39.png 28-Jul-20 10:11 PM it says it takes 220V at 1200Hz (and draws 7-15 mA), and can display one of the four characters pictured or just the background colors 28-Jul-20 10:11 PM and it has blue and yellow colors, and becomes white if you light up both 28-Jul-20 10:11 PM I do not see the pinout though 28-Jul-20 10:19 PM Oh wow. 28-Jul-20 10:31 PM I'm trying to read the description but it sounds confusing. My understanding is that you can separately light up just the outside contour of each of these symbols, and the "fill"; but that means 8 pins for that + 2 for each of the "raster" backgrounds (blue and yellow) + 1 for the "solid color" pin which means there should be a total of 11 pins? idk 28-Jul-20 10:31 PM there's also a table on page 192 (and before), which says that for type IX indicators pin 1 belongs to "switching group A", pin 3 to "switching group B", and pins 2 and 4 are the "non-switched electrodes" - but it doesn't offer a clear explanation for what this all means 28-Jul-20 10:54 PM Another book from 1971 has even fewer details about these specific parts, but recommends using a blocking oscillator to drive them 28-Jul-20 10:54 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screen_Shot_2020-07-28_at_10.52.45_PM-3B810.png 29-Jul-20 08:05 AM Winding 2 in that diagram looks suspicious to me, it is shorted.... 29-Jul-20 08:06 AM yeah it should not be connected to R1 29-Jul-20 02:22 PM Hmmm..... 29-Jul-20 02:22 PM The item in question has printed black lines on it displaying a rectangle as appears second from the left so I assume that is the shape. 29-Jul-20 02:22 PM These seem to be used for display boards of some kind, but are those four symbols somehow meaningful? 29-Jul-20 02:22 PM An arrow, a rectangle, a diamond, and a teardrop? 29-Jul-20 02:22 PM As for the fuse: 29-Jul-20 02:22 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-B34FE.jpg 29-Jul-20 02:22 PM Text says 0280 and under that 5.0A 29-Jul-20 02:22 PM I’m not sure if the top is a date code (Feb 1980 would be reasonable given the hardware) or if it is a part no. 29-Jul-20 02:22 PM Length appears around 15.2 mm diameter of cap 3.7 mm but there’s gunk on the fuse. 29-Jul-20 02:22 PM The machine has a 3A fuse too and the power supply has a pair of fuses. 29-Jul-20 02:47 PM Looking at the other fuses, it seems like a date code, not a part number. 29-Jul-20 07:06 PM <𝓕ermion#6024> I may have asked this before but does anyone know of a commercially available kf nipple with a flange in the middle for connecting a hose through a wall? 29-Jul-20 07:06 PM <𝓕ermion#6024> I'm also tempted to just take two bristle-brooms and oppose them and push the vacuum hose through that lolol. 29-Jul-20 07:26 PM I'm probably envisioning this incorrectly, but can you not just use half nipples? 29-Jul-20 07:26 PM Or do you mean like a full nipple with a flange on the side for a T? 29-Jul-20 07:26 PM Which would actually just be a T so I don't know why I described it like that 29-Jul-20 07:51 PM <𝓕ermion#6024> Oh I just want a full nipple with a flange in the mid plane 29-Jul-20 07:51 PM <𝓕ermion#6024> The midplane between the planes defined by the two flanges. 29-Jul-20 07:51 PM <𝓕ermion#6024> I want to cross through a wall. Like a wall in a building. 29-Jul-20 08:02 PM Do you have a crude sketch? Maybe I just need sleep, but I'm still only either seeing a T or something you can just make with two full nipples. Or I guess, is the set up vacuum hose-full nipple-do whatever on the other side of the wall with the KF flange? 29-Jul-20 08:04 PM I can't envision 29-Jul-20 08:16 PM <𝓕ermion#6024> let's just do a little of the ol'... fusion 360 29-Jul-20 08:16 PM <𝓕ermion#6024> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-519C2.png 29-Jul-20 08:16 PM <𝓕ermion#6024> I want this. 29-Jul-20 08:22 PM Oh, that kind of flange 29-Jul-20 08:22 PM Yeah, I'm not aware of any. I had to make something similar as a VUV lens holder and couldn't find anything when I looked back then. 29-Jul-20 08:22 PM Your machine shop is probably cheaper, but that looks like something Lesker could make if you asked tbh 29-Jul-20 08:24 PM These seem to be used for display boards of some kind, but are those four symbols somehow meaningful? @rdpierce I believe they are meant to be used in some kinds of control panels, where they have a diagram of the plant with these displays indicating the status of various things, kind of like modern HMI displays but with physical lights in a panel 29-Jul-20 08:25 PM Actually, what size is that middle flange? 29-Jul-20 08:25 PM <𝓕ermion#6024> oh I don't really care tbh. 29-Jul-20 08:25 PM <𝓕ermion#6024> I just wanna panel mount the nipple. 29-Jul-20 08:31 PM This might be a stupid idea/look a bit ridiculous, but two KF to CF flange adapters with the two CFs meeting and acting as the mount? 29-Jul-20 08:31 PM Or ASA but that would be more expensive based off a quick look at lesker/ideal 29-Jul-20 08:37 PM is that middle flange supposed to seal vacuum? 29-Jul-20 08:41 PM The way I'm envisioning it is that it's literally just a mount. The middle needs to have vacuum, but the mount doesn't 29-Jul-20 08:45 PM Then why a flange like that ? 29-Jul-20 08:45 PM Like if it’s just a mount 29-Jul-20 08:45 PM Just clamp it? 29-Jul-20 08:58 PM <𝓕ermion#6024> no it's not supposed to seal vacuum 29-Jul-20 08:58 PM <𝓕ermion#6024> I want it to seal noise basically 29-Jul-20 08:58 PM <𝓕ermion#6024> there's a bunch of pumps behind the wall 29-Jul-20 08:58 PM <𝓕ermion#6024> also I like clean panel mounts... like there's a bunch of lines going through the same panel. 29-Jul-20 08:58 PM <𝓕ermion#6024> one for helium return, one for sorb cooling, etc. 29-Jul-20 08:58 PM <𝓕ermion#6024> a USB cable for controlling the pumps... 29-Jul-20 09:07 PM Oh lol 29-Jul-20 09:39 PM <𝓕ermion#6024> actually I'm gonna be a good physicist and do a half-baked job of this 29-Jul-20 09:39 PM <𝓕ermion#6024> and take a KF nipple and just throw some expanding foam around it lol. 29-Jul-20 09:39 PM <𝓕ermion#6024> and then screw the thing in place. 29-Jul-20 09:39 PM <𝓕ermion#6024> that'll hold it and seal the air around it. 29-Jul-20 09:40 PM That's the spirit 29-Jul-20 09:41 PM <𝓕ermion#6024> right?! 29-Jul-20 09:41 PM <𝓕ermion#6024> I just need to lean into doing it sloppily. 29-Jul-20 09:44 PM If it's a stupid idea that works, it's still a stupid idea but I don't care scoreboard. 29-Jul-20 09:56 PM I just love waterjetting clamps 29-Jul-20 09:56 PM I made a super fancy 3D thing to support my forevacuum lines 29-Jul-20 09:56 PM all out of 2D cuts of 1/8" aluminum plate 29-Jul-20 09:56 PM with no extra tools needed 29-Jul-20 10:11 PM <𝓕ermion#6024> oh yeah water jet is great. 29-Jul-20 10:11 PM <𝓕ermion#6024> I guess I could water jet some goofy thing. 29-Jul-20 10:18 PM I mean you can make exactly what you want 29-Jul-20 10:18 PM And then clamp instead of weld 29-Jul-20 10:18 PM And spray insulation for silence 29-Jul-20 10:23 PM <𝓕ermion#6024> @Mezmorizor does the guy from explosions and fire hang out in the chem server? he kinda talks like someone who would. 29-Jul-20 10:24 PM which chem server? 29-Jul-20 10:24 PM Because he is sometimes active over in the ex&f server (which is a magnificent mess sometimes always) 29-Jul-20 10:31 PM No, but as far as I know he's a legitimate energetic materials chemist and is on reddit occasionally. 29-Jul-20 10:31 PM I don't think we have anyone particularly notable as far as I know 29-Jul-20 10:31 PM I guess one homechem person that has a youtube channel that averages ~100 views per video though I haven't seen them in a while 29-Jul-20 10:31 PM And the chem server he's referring to is the one in the "science network" 29-Jul-20 10:34 PM Ah, ok 29-Jul-20 10:34 PM Or I think she calls it "discord science network" 29-Jul-20 10:34 PM I'm also sad because our resident energetics materials guy just went MIA ~10 months ago 29-Jul-20 10:36 PM <𝓕ermion#6024> oh he knows what he's doing? 29-Jul-20 10:36 PM <𝓕ermion#6024> there's a lot of jam jars in his setups 29-Jul-20 10:37 PM I might be wrong, but I think so 29-Jul-20 10:37 PM <𝓕ermion#6024> I guess if you know what you're doing, you know where you can use a jam jar. 29-Jul-20 10:40 PM Hmm, I might be thinking of someone else. They're definitely a trained chemist, but I'm starting to second guess the energetic materials part. 29-Jul-20 10:40 PM Though I guess the fact they successfully made azidoazide is proof they're a trained chemist 29-Jul-20 10:40 PM I don't know, I haven't really watched them but they apparently have the seal of approval from the big names in the energetic materials field, so when they used a jam jar it must have been okay to use a jam jar 29-Jul-20 10:40 PM Meanwhile I still use the blast shield when I do peroxide formation tests 29-Jul-20 10:50 PM Or that they are a young chemist 30-Jul-20 05:46 AM how’d they confirm it’s azidoazide lol 30-Jul-20 05:46 AM I’ve heard stories of high nitrogen compounds blowing up ir specs, I’d be scared to do any analysis on it lol 30-Jul-20 06:03 AM So i've got a pair of roughing pumps that my old student job rescued from physics department waste years ago, how do i make sure i'm not killing myself with whatever might be in their oil? 30-Jul-20 06:03 AM Kinda wanna use them but have heard real scary stories about used vacuum pump oil 30-Jul-20 06:45 AM If you are worried, you can change the oil once or twice. If you are super-worried, you can disassemble them and clean thoroughly all the parts in ultrasonic cleaner with some solvent. But I would go just with changing oil - just do it properly (turn it on, let it heat thoroughly and after then change the oil)... 30-Jul-20 06:45 AM Do anyone have idea what is the difference between RGA MKS Microvision2 and eVision2? 30-Jul-20 07:10 AM Can you just... ask what they used? If you got a roughing pump from us we'd say "helium, nitrogen, oxygen, CS2, a hair of SO2" 30-Jul-20 09:52 AM I used to have access to a waterjet. Those were the days.... I now have to pay through the nose to get anything cut by waterjet.... 30-Jul-20 09:54 AM paid service waterjetting is actually pretty reasonably priced IMO 30-Jul-20 09:57 AM For one off parts? 30-Jul-20 09:58 AM Well I mean what is reasonable? I've only done it once and it was $50 for something that took about 10 minutes of cutting time 30-Jul-20 09:58 AM but for me to do it myself that'd be like 30 minutes total ish 30-Jul-20 09:58 AM we can use our waterjet for small personal things free, but lab stuff is billed at "cost of maintenance" which is around $1.50/minute 30-Jul-20 09:58 AM so for a business to charge $50 for something like that seems pretty good! 30-Jul-20 10:09 AM I’m not sure if the top is a date code (Feb 1980 would be reasonable given the hardware) or if it is a part no. @rdpierce Friends say it's just a generic jelly bean 5A ceramic fuse, nothing special about it - so anything you find that's of a matching size should work. 0280 is indeed a date code. 30-Jul-20 10:09 AM @Mezmorizor what’s your helium consumption like? I feel worried about dropping 100Psi over a month, that seems like a leak... 30-Jul-20 10:11 AM Don't know off the top of my head/it wouldn't be super accurate in recent memory because we've had a lot of things break in the past couple months which means a lot of downtime, but that sounds really high to me 30-Jul-20 10:12 AM Yeah. From 1100 PSI to 1000 PSI. It's simultaneously really high, and low enough that I don't think I can a leak easily... Nothing with SNOOP 30-Jul-20 10:36 AM oh what that was a huge leak easily found by snoop 30-Jul-20 10:39 AM @idmb You are talking about coldhead? 30-Jul-20 10:44 AM No, the helium line that goes to the nozzle attached to my cold head 30-Jul-20 10:44 AM The self-sealing lines on the cold head are so excellent that since they ship it overcharged, I actually had to vent quite a bit! 30-Jul-20 10:52 AM @vovchik I agree it isn’t special. What I’ve heard from crypto collectors is that these fuses are not size compatible with anything in the US, so they’re hard to come by. 30-Jul-20 10:52 AM If that’s not the case and they can be acquired inexpensively in bulk, well, I’ll have made a bunch of people very happy. 30-Jul-20 10:52 AM There’s a crossover between crypto and radio collectors, especially spy radios. I was looking at Soviet radios for spies living behind enemy lines. They were special versions of the military radios, typically with fuse holders replaced so they can use local fuses. Also, lettering was English. If found by police, it would arouse less suspicion, and some recruited spies didn’t speak Russian. They’d often use a burst encoder so time on air would be short and direction finding wouldn’t be useful. 30-Jul-20 01:00 PM fascinating stuff about the radios! I'd love to learn more about them, if you have links to share. I'll ask friends in Belarus to go buy a bag of these fuses if they still make this size - what other amp ratings are you interested in? 30-Jul-20 01:00 PM also I've been told that the holders for these fuses sometimes double as input voltage selectors, you rotate them to pick the voltage 30-Jul-20 01:00 PM https://www.ebay.com/itm/5-x-Vintage-Russian-Small-Ceramic-Fuse-4x15mm-5A-250V-NOS-Silver-Plated-/264555027933 this may be what you need 30-Jul-20 01:21 PM Interesting. The Fialka uses 3 and 5 amp fuses, as does its power supply. 30-Jul-20 01:27 PM https://www.ebay.com/itm/5-x-Vintage-Russian-Small-Ceramic-Fuse-4x15mm-3A-250V-NOS-Silver-Plated/264555024310 here's a 3A from the same seller I think 30-Jul-20 02:31 PM Coolness, thanks!!! 31-Jul-20 12:58 PM <𝓕ermion#6024> good lord I wish I was better at welding 01-Aug-20 05:46 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/1596329287376450077007770885955-4F859.jpg 01-Aug-20 08:14 PM Funny how they doxxed the kid 01-Aug-20 09:04 PM wonder what he's up to these days 01-Aug-20 09:04 PM also yeah lol 01-Aug-20 09:04 PM 'Don't worry anyone near this EXACT ADDRESS, he's got dozens of water jugs!!' 01-Aug-20 09:04 PM Also where do I find bored physicists with enormous dipole magnet yokes just sitting around 01-Aug-20 11:22 PM Reminds me of someone I took physics with at UChicago. 01-Aug-20 11:22 PM He made his own cyclotron and linac, I believe, as a kid. 01-Aug-20 11:22 PM Made a "breeder reactor" (really, just demonstrating neutron activation of thorium) for a Scav Hunt contest. 02-Aug-20 12:33 AM Also where do I find bored physicists with enormous dipole magnet yokes just sitting around @qualia I am sorry, but aren't you just that? :D 02-Aug-20 12:34 AM it's not that enormous it's just a wee analyzer 02-Aug-20 12:34 AM :D 02-Aug-20 12:35 AM i hafta flip it on its side without busting it all out of shape.. reminds me i gotta cut some wood 02-Aug-20 01:08 AM http://www-aladin.gsi.de/www/kp3/aladinhome.html I know that that dipole is to be disposed of 02-Aug-20 01:08 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/61908f4dfc-F5B88.png 02-Aug-20 01:08 AM is that big enough for you? 02-Aug-20 01:08 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/4f8a5fd757-EC0D2.png 02-Aug-20 01:08 AM is this big enough for you? 02-Aug-20 01:08 AM will be replaced by this fun thing 02-Aug-20 01:08 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/P1030803-B5FA0.JPG 02-Aug-20 02:10 AM sure that'll do 02-Aug-20 02:10 AM honestly?? i just need to build a coil winding rig 02-Aug-20 02:12 AM and by coil you mean copper tubing from the hardware store 02-Aug-20 02:12 AM isolated with a few km of kapton 02-Aug-20 02:12 AM question is what do you want to do with that magnet 02-Aug-20 02:12 AM Hm a betatron would be fun 02-Aug-20 02:40 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/49753133391_3787bab94a_o-8A02C.png 02-Aug-20 02:40 AM magnet. 02-Aug-20 02:40 AM (LHCb dipole) 02-Aug-20 06:26 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200802_152559-A75E8.jpg 02-Aug-20 06:26 AM and this is why you plan stuff ahead 02-Aug-20 06:26 AM can't get the clamp on there 02-Aug-20 07:53 AM Because of the top? 02-Aug-20 07:53 AM Looks like the chain style might work? 02-Aug-20 07:57 AM it works if I remove the iso ring, put on the clamp and then reinstall the iso ring 02-Aug-20 07:57 AM just a tiny bit annoying 02-Aug-20 07:57 AM Is that a rotatable iso flange ? 02-Aug-20 07:58 AM yep 02-Aug-20 07:58 AM the rings are there to turn ISO-K into ISO-F 02-Aug-20 07:58 AM as since the part has no groove for ISO-K it has to be used with the rings 02-Aug-20 08:13 AM Nice and lucky for your KF I guess 02-Aug-20 08:13 AM I put bolts in all my homemade part drawings 02-Aug-20 08:13 AM But naively assume the standard parts are fine 02-Aug-20 08:17 AM do you know the best part? 02-Aug-20 08:17 AM it's got a major leak and now I have to tear it all down again 02-Aug-20 08:17 AM RV alone gets down to 1.6 mbar, turbo to 0.2 mbar 02-Aug-20 08:19 AM @GigaSquirrel do you have a guide for turbo repair? I remember you posting a resource in a recent twitter thread but can’t find it 02-Aug-20 08:20 AM I never posted a recource, but I did repair a few turbos 02-Aug-20 08:20 AM what pump are we talking about? 02-Aug-20 08:20 AM Hmm maybe someone else posted a resource and you were in the thread, I’ll have to search 02-Aug-20 08:20 AM maybe you mean the glasslinger video where they repaired a turbovac 150? 02-Aug-20 08:20 AM I’m gonna try and just clean up the pfieffer TMH I got 02-Aug-20 08:20 AM Maybe that was it I’ll search some more. 02-Aug-20 08:21 AM just cleaning the rotor is easy, the hv flange lifts away from the rotor and then you have to disassemble the stators top down 02-Aug-20 08:21 AM usually all just stacked and can be moved without any force 02-Aug-20 08:22 AM Lol i wouldn’t turn my turbos on at 1.6mbar 02-Aug-20 08:23 AM eh, it was an old turbovac that I've gotten to know quite well by now 02-Aug-20 08:23 AM The old one is the one I’m most picky about 02-Aug-20 08:23 AM Sounds like a jet 02-Aug-20 08:23 AM When turning on 02-Aug-20 08:23 AM same 02-Aug-20 08:23 AM And the controller only reads frequency 02-Aug-20 08:23 AM The others all show current, so you can see if there’s an issue 02-Aug-20 08:24 AM I just go by sound 02-Aug-20 08:24 AM ofc it's not ideal, but it works for a test 02-Aug-20 08:24 AM I just wanted to make sure it's a leak and not extreme outgassing 02-Aug-20 08:24 AM we've got >70% humidity at 27°C at the moment, that could also be enough for about a mbar of water vapor pressure 02-Aug-20 08:27 AM Outgassing is overrated tho 02-Aug-20 08:27 AM A tiny scroll pump did like 50m of 4” PVC that was freshly solvent welded down to 0.1mbar in less than 10 minutes 02-Aug-20 08:28 AM in my experience there can be a small plateau at ~0.5 to 1 mbar that takes some time until it is pumped, usually you get right through it with a turbo 02-Aug-20 08:29 AM I stand by my “I could lick my chamber and it would still be -7 in an hour” 02-Aug-20 08:29 AM oh definitely 02-Aug-20 08:29 AM I'm talking about very high humidity and bad chamber geometry 02-Aug-20 08:29 AM https://www.youtube.com/watch?v=QzSqwSrdQ5M 02-Aug-20 11:03 AM @mike crb maybe this one? https://spirit.re/projects/ext255h.php 02-Aug-20 11:07 AM Ahh I think it was that one 02-Aug-20 11:07 AM If not that is still a useful write-up, thanks 02-Aug-20 07:28 PM <𝓕ermion#6024> that's an incredible writeup 02-Aug-20 07:28 PM <𝓕ermion#6024> truly the most physicist solution I could imagine 02-Aug-20 07:28 PM <𝓕ermion#6024> I guess what's the worst that could happen, it throws another blade? lol... 03-Aug-20 10:15 AM Huh you could get pvc reinforced vacuum line from scrap vacuum cleaners 03-Aug-20 10:15 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-CE541.jpg 03-Aug-20 10:22 AM The problem with it is that it moves around a lot on you and tries to shrink in length. Additionally it does not have enough plastic in it to seal well enough at the ends for our purposes and does not take clamps well. 04-Aug-20 01:27 AM more newbie questions related to my hopeless SEM repair project. I think I fixed the defective power supplies, and the vacuum gauge now reads 0% vacuum (that is, atmospheric pressure) as opposed to the 176% it was reading before. I think it was a loose wire, as it started working after I unplugged and reconnected the cables between it and the relay board. 04-Aug-20 01:27 AM I'm going to hook up water to the diffusion pump and try to actually pump it down (it won't open the valve until the DP is running, and that's the intended behavior according to the diagram in its manual). I do see one more suspicious thing: the left CRT (that displays the scanned image, as opposed to the stored image) is dark, and the "CRT voltage" and "PMT voltage" all read 0. All of those voltages, and the acceleration voltage, come from the same big oil-immersed power supply. 04-Aug-20 01:27 AM so the question is, is the supply supposed to come on even when it's not pumped down? or is the whole thing all turned on at once when it's at vacuum and you press "HT ON"? 04-Aug-20 01:27 AM it's a JEOL JSM-5400, and I suspect all CRT display JEOLs work in a similar way 04-Aug-20 01:27 AM I'd love to learn more from someone who's been around a working one 04-Aug-20 01:27 AM I did have to fix a few things in the HV tank, and the electronics of this SEM was in a pretty bad state overall, so not sure if it's broken or working as intended 04-Aug-20 03:52 AM Hello. I have a question. I haven't used my vacuum system in months (diffusion to mechanical pump). Yesterday I turned on and I got a ton of moisture from the mechanical pump outlet. Do you know if difussion pump oil is hygroscopic? I changed mechanical pump oil and no difference. 04-Aug-20 03:57 AM Are you sure that it is moisture? Usually when pumping large volumes, not only moisture but oil mist comes from the outlet... 04-Aug-20 03:58 AM Is a small chamber. I think is moisture 04-Aug-20 06:11 AM @vovchik I don’t know the specifics. 04-Aug-20 06:11 AM I do know that there are typically interlocks so that one cannot turn on the filament current or apply HV to the column unless the system is at high vacuum. 04-Aug-20 06:11 AM Otherwise the filament would burn out and the system would destroy itself due to internal arcing. Not to mention the safety risk. (If the system is under vacuum, then it follows it is closed, and a technician doesn’t have their hand inside it, so isn’t at risk of being hit with 20-40 kV.) 04-Aug-20 06:11 AM You should never be able to turn on HT to the column without vacuum. 04-Aug-20 06:11 AM PMT voltage may be safety related too. 04-Aug-20 06:11 AM You never want to power a PMT if exposed to light. 04-Aug-20 06:11 AM It follows that if the system is at high vacuum, the chamber door must be closed, so it’s OK to turn on the HV. 04-Aug-20 10:27 AM Makes sense - so it is likely the entire HV supply is powered down. There's nothing to see on the CRT if the beam isn't on, either. 04-Aug-20 10:27 AM I'm also curious if there's a trick to acquiring service manuals for them. Mine came with the user guide in a three ring binder, but it only covers normal operation and a little bit of vacuum system troubleshooting. I emailed JEOL, and got a response from the German service folks who were very friendly but said they can't help with microscopes sold in the US market. And the US folks just never replied to my emails, as I'd expected. 04-Aug-20 11:35 AM @vovchik I've had JEOL U.S. reply to me... But that was from their parts/sales dept 04-Aug-20 12:24 PM @nmz787 I cannot believe this but... I just filled the contact form on the JEOL website the second time, and got a phone call within minutes, and they already emailed me the maintenance manual (which doesn't have schematics but is significantly more detailed than the one I have) 04-Aug-20 12:27 PM Haha 04-Aug-20 02:05 PM I am impressed. High fives, JEOL. 04-Aug-20 05:15 PM Can they get me a cable diagram pin out for my Leybold turbo pump? Hahahahaha 04-Aug-20 05:15 PM I have gotten nothing but static from them. 04-Aug-20 05:49 PM What model? I may be able to measure for you. 04-Aug-20 10:48 PM NT 360 05-Aug-20 07:58 AM for a TMP 360? 05-Aug-20 07:58 AM The NT are just the controllers afaik 05-Aug-20 09:18 AM Hello. Anyone have experience using a vacuum system in a rainy day or in high humidity day? 05-Aug-20 09:18 AM My mechanical pump is getting out some moisture vapor 05-Aug-20 09:22 AM Are you sure that it is moisture? Usually when pumping large volumes, not only moisture but oil mist comes from the outlet... 05-Aug-20 09:24 AM Yes, I'm sure is moisture 05-Aug-20 09:29 AM Well I have both the controller and the 360 pump but no cable. 05-Aug-20 09:29 AM It was probably left cable tied to the device it was salvaged out of cause surplus people have no concept of, well anything. 05-Aug-20 09:32 AM @KevinSchuller If it is moisture, then where is the problem? 05-Aug-20 10:59 AM @bkralik maybe is excessive air humidity or maybe I have a leak in the chamber 05-Aug-20 11:00 AM if you have a leak that passes significant amounts of water you won't get much below 500 mbar 05-Aug-20 11:08 AM I reach 50 Pa (0.5mBar) and I can see a constant thin flow of moisture coming out of the mechanical pump 05-Aug-20 11:08 AM I changed the oil of the machanical and diffusion pump to check if that is the problem 05-Aug-20 11:08 AM I think I need to wait a sunny day to dry the air 05-Aug-20 11:11 AM that sounds like a heavy leak 05-Aug-20 11:34 AM Are you sure it is moisture coming out of the pump and not just an oil mist? 05-Aug-20 11:34 AM Must be really humid or your chamber was wet if you are seeing moisture coming out of the outlet... 05-Aug-20 11:35 AM I've seen moisture condense in the chamber, but never on the outlet 05-Aug-20 11:35 AM https://www.youtube.com/watch?v=QzSqwSrdQ5M 05-Aug-20 11:37 AM Yeah exactly...you can definitely see a slight fog of oil mist when my roughing pumps are going and things are pumping down but moisture coming out of the pump sounds really odd 05-Aug-20 12:11 PM @KevinSchuller I live in Oregon where it's wet most of the year... Never had an issue like that 05-Aug-20 12:11 PM Have you stuck you hand in the mist and felt it to ensure it's not oil? 05-Aug-20 12:11 PM I've definitely seen oil mist 05-Aug-20 12:11 PM And in one of my processes I'm actually injecting water into my vacuum chamber, and haven't noticed moisture cloud/mist coming out the pump 05-Aug-20 01:19 PM How long did you take to reach that 50 Pa? 06-Aug-20 10:47 AM <𝓕ermion#6024> my new pump and enclosure fits!!!11 06-Aug-20 10:47 AM <𝓕ermion#6024> I'm so excited 06-Aug-20 10:47 AM <𝓕ermion#6024> and I can barely hear it from inside the room I'll be running my experiments 06-Aug-20 10:50 AM woohoo! 06-Aug-20 10:51 AM <𝓕ermion#6024> just gotta get the heater and thermometry wired up and I'll give this thing its first cooldown in like a decade lol 06-Aug-20 11:16 AM I can’t hear my junk because of my other junk 06-Aug-20 11:27 AM Is anyone aware of typical problems with old Osaka magnetic levitation turbos? 06-Aug-20 02:50 PM No but 1/1 I have encountered or heard gossip of is a paperweight 06-Aug-20 03:29 PM <𝓕ermion#6024> does anyone have a favorite db9 cable hood connector thingy 06-Aug-20 03:29 PM <𝓕ermion#6024> I have to make a bunch of cables 06-Aug-20 03:29 PM <𝓕ermion#6024> just want something properly clamped and strain relieved 06-Aug-20 04:12 PM If it's decent, it's got a dual screw clamp to clamp the cable for strain relief. 06-Aug-20 05:52 PM <𝓕ermion#6024> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-ED4DD.png 06-Aug-20 05:52 PM <𝓕ermion#6024> uhm... 06-Aug-20 08:16 PM oh, strain relief as in 'I can stand on them' 06-Aug-20 10:58 PM an update on my disaster-SEM-rebuild project: I found the diffusion pump heater wires sheared off (likely in transportation) - I re-crimped them and it begins to heat up now when connected to power. This means it's time for more newbie questions! 06-Aug-20 10:58 PM This is the diffusion pump, which side is the cooling water supposed to go into? 06-Aug-20 10:58 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_6627-BE79B.JPG 06-Aug-20 10:58 PM or does it not really matter? 06-Aug-20 11:07 PM That Amphenol db9 shell gets a thumb's up from me as well 06-Aug-20 11:07 PM robust and can easily have very good strain relief. 06-Aug-20 11:15 PM noice 07-Aug-20 12:08 AM I'd let it run so that the inlet is at the high vacuum port @vovchik 07-Aug-20 01:34 AM @vovchik yeah basically you want it coldest at the top, and least cold at the bottom 07-Aug-20 01:34 AM So that means the baffle will be the first inlet, then the outlet of the baffle gets hooked to the inlet/top of the main pump body 07-Aug-20 01:34 AM I'm guessing the baffle is just horizontal, with no vertical sections in it... But never having disassembled that part of my scope, I'm not sure 07-Aug-20 06:27 AM @vovchik cold is a relative term too. I have found they run best when the water going to the diffusion pump is about 20C or so. Most small pumps like that have trouble maintaining temperature with really cold water. 07-Aug-20 11:51 AM Joined the server. 08-Aug-20 06:35 PM alright, I hooked up water, the SEM let it heat up for about 10 minutes (the heater shroud went up to 150C, and there was a very slight smell of hot plastic but no obvious source for it) and it opened the valves for rough pumpdown ("PRE-EVAC"). The sound of the rotary pump slowly changed from "obviously pumping lots of air" to "spinning freely", and I can't open the chamber lid any more - but the vacuum gauge still reads 0% and it doesn't switch to the DP ("EVAC" state). 08-Aug-20 06:35 PM Looks like the vacuum sensor or its electronics are broken after all 08-Aug-20 06:35 PM both the 175% and the 0% are wrong 08-Aug-20 06:35 PM I will need your help identifying the sensor, I have no idea what it is supposed to look like - but there's a small round device right below the EDS port and it looks like this from the outside and from inside the chamber, respectively 08-Aug-20 06:35 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_6552-55041.JPG 08-Aug-20 06:35 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_6553-5754D.JPG 08-Aug-20 06:35 PM do you think this is the vacuum gauge? it's got two wires running to it from the board that controls all the solenoid valves for the vacuum system 08-Aug-20 06:35 PM the board in question 08-Aug-20 06:35 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_6557-ACF12.jpeg 08-Aug-20 06:35 PM where the sensor (?) connects; I don't see any analog circuitry near it 08-Aug-20 06:35 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_6549-6E01A.jpeg 08-Aug-20 06:35 PM if that's not it - where would the vacuum gauge be in a SEM, and what'd it look like? 08-Aug-20 06:44 PM only two wires running from it? if i had to guess its a pirani gauge 08-Aug-20 06:45 PM only two wires. It may not be the gauge - it's just the only thing without an obvious (to me) other function on the column 08-Aug-20 06:45 PM but tbh not really sure haven't worked with anything that works quite like that so idk 08-Aug-20 06:45 PM looking at the picture from the inside, it may even be an LED to light up the chamber? 08-Aug-20 06:46 PM is there a ccd for imaging the inside of the chamber? 08-Aug-20 06:46 PM if so that would make sense that there's an led inside 08-Aug-20 06:48 PM there is no CCD, but there is a sight glass 08-Aug-20 06:48 PM it'd not make a lot of sense to look through it into a dark chamber 08-Aug-20 06:48 PM specifications say there's one Pirani gauge 08-Aug-20 07:00 PM bonus thermal image of the DP (that SEM thinks is at temperature) 08-Aug-20 07:00 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/heat-4AA68.jpg 08-Aug-20 07:35 PM that's definitely the Pirani gauge, I took it out and looked at it - there's a coiled filament, like in a light bulb, stretched several times along a glass rod in the center. It has two wires and reads 25 ohms between them. 08-Aug-20 11:10 PM @vovchik you had the rough pump on and connected (valves open) before turning on the diff pump, right? 08-Aug-20 11:11 PM yes, correct 08-Aug-20 11:11 PM from what I understood of the wiring between all the relays, the roughing pump and the DP are powered on at the same time, and in the initial state the RP is only connected to the DP to evacuate it as quickly as possible - everything else is closed 08-Aug-20 11:11 PM it sits in that state until the DP comes up to temperature, and then it starts pumping down the main chamber with the RP 08-Aug-20 11:15 PM Best bet is to buy a mks901p gauge and connect it up somewhere for sanity check 08-Aug-20 11:16 PM I just removed the relay control board, and found the test points for the Pirani gauge. It's just going to a comparator, there is no ADC - but its output is also going to some other board via a cable. 08-Aug-20 11:16 PM https://www.ebay.com/itm/MKS-VACUUM-LOADLOCK-TRANSDUCER-901P-11040-Tested-Guarantee/254464187639?epid=1438064168&hash=item3b3f3f5cf7:g:u6AAAOSwAtlasIKi 08-Aug-20 11:16 PM oh, it's cheaper than I expected! what do you connect it to? 08-Aug-20 11:17 PM You mean electronically? Or vacuum connection? 08-Aug-20 11:17 PM Just usb to serial to a laptop is easiest 08-Aug-20 11:17 PM Vacuum it's a kf16 I believe 08-Aug-20 11:18 PM I was asking about the electrical connection first - looks like it's got all the signal processing onboard and just talks RS-232? really cool 08-Aug-20 11:18 PM So you'd need to find a spot to interface some adapter to on your system 08-Aug-20 11:18 PM Yep 08-Aug-20 11:18 PM Protocol fully published in their PDF manual 08-Aug-20 11:18 PM Which doesn't need a login to download 08-Aug-20 11:18 PM I've got a Python script if you're interested 08-Aug-20 11:18 PM https://gist.github.com/nmz787/9ef47851c79d84f4d05aabc2c4d282e6 08-Aug-20 11:19 PM awesome! I'm going to order one 08-Aug-20 11:19 PM On one setup I used that script on a raspberry Pi with a little LCD panel 08-Aug-20 11:21 PM fantastic, thank you very much, that'll definitely be useful 08-Aug-20 11:21 PM in the meantime I'm going to poke around the board and measure the voltage from the Pirani gauge test points, see if it changes at all 08-Aug-20 11:22 PM You're playing with a Jeol? 08-Aug-20 11:22 PM yes, JSM-5400 08-Aug-20 11:22 PM I basically had the same experience with my JSM-T200... turned it on for a while and just nothing besides pumps on 08-Aug-20 11:22 PM Didn't have the mks gauge then, and still didn't get it hooked up 08-Aug-20 11:22 PM Started tearing down the column and found oil all the way up to the electron gun 08-Aug-20 11:22 PM Got replacement apertures but never put things back together in like 9 or 10 months :( 08-Aug-20 11:25 PM I'm expecting more surprises from this one, too. I already lost count of the things I had to fix just to get it to the point where it pumped some air out of the column 08-Aug-20 11:25 PM the most surprising thing is that it arrived under vacuum, and then lost it in about a month of sitting at my place 08-Aug-20 11:25 PM one friend has a theory that it wasn't under any real vacuum after all, but somehow in shipment the chamber door closed at a low altitude and it had just the tiny bit of atmospheric pressure difference holding it shut doesn't sound credible to me, but I also don't see how this could have worked in the last couple years 08-Aug-20 11:48 PM The JSM-T200 looks adorably small 09-Aug-20 12:42 AM I did a couple more experiments: the test point for the Pirani gauge reads 1.3v at atmospheric pressure, and when I press "evac" it slowly goes up to about 1.6V. The "evac" comparator setpoint is at 2.3v. However, once it reaches 1.6, I can hear valves clicking and the chamber admits a bit of air again (?), and the rotary pump makes pumping sounds for a few more seconds. Then after a few seconds valves click once more and it starts pumping down to 1.6v again... 09-Aug-20 12:42 AM all this time the SEM console reads 0% vacuum, clearly there's something wrong with the readout (it gets the exact same 1.3v-1.6v signal that I'm reading on my scope) 09-Aug-20 12:42 AM also after a while in this state the SEM console starts to oscillate between the "pre evac" and "vent" states rapidly, but no valves are clicking this time, and the voltage stays at 1.6v 09-Aug-20 12:42 AM I turned it off shortly after just in case it does something silly 09-Aug-20 01:30 AM oh ok, looks like I found the problem. Whatever the main screen says is not actually relevant; the relay board controls the pumping sequence. The two threshold test points read 2.3v and 1.6v - which I assume are the boundaries for "safe to turn on HV" and "connect DP" 09-Aug-20 01:30 AM so it comes up to 1.6V, whatever vacuum that is, on the rotary pump, and opens the DP, and somehow it causes the pressure to go up slightly instead (a leak??) and so it closes it again 09-Aug-20 08:11 AM @vovchik That sounds very reasonable to me. I have no experience with any JEOL SEM, but I have worked with a HItachi S-2400 SEM which also uses two set points in its evacuating sequence - one to pump down the chamber with the DP and one to enable Filament and HV. The S-2400 has a separate Relay for the DP, but when the SEM is started as usual both are turned on basically at the same time. As you have some sort of pirani readout inside the evacuating sequence board I totally support your hypothesis that there is some leak at the diffusion pump. However: afaik running a DP at a poor vacuum will burn its oil. If that is the case you might prefer to do your debugging with the DP's heater disconnected and you might want to check the DP by unmounting it or by disconnecting the forevacuum connection of the dp and take a little sample of the oil with a syringe/ check for any burnt smell. I have once seen a DP with a crust of burnt oil on it's heaters surface, but I do not know how this was caused. 09-Aug-20 03:19 PM another try today: the SEM pumps down to 1.6V Pirani test point voltage with the rotary pump, then opens the DP which quickly takes it down to 2.15V where it just sits. It's supposed to reach 2.3V before it turns on HV. 09-Aug-20 03:19 PM the only thing I changed from yesterday was more water flow for cooling: it's specced at 2L/min, but yesterday I measured closer to 1L/min. Which didn't cause the pump to overheat (water was still cool at the outlet) but might have caused the sensor (mounted on the cooling baffle) to think the pump it's at temperature too soon, and open it when it's not really at temperature yet. 09-Aug-20 03:19 PM the heater reads 185C now, not 150 like it did yesterday 09-Aug-20 03:19 PM the spec says it takes 3 minutes to evacuate the chamber fully, and I measured about 3 min 15 seconds (once everything is at temperature), about 2/3 of that is just the RP going from 1.3v to 1.6v, the DP then takes it further very quickly. 09-Aug-20 03:19 PM what would cause a diffusion pump to work quickly but not reach the correct ultimate pressure? bad / not enough oil? 09-Aug-20 03:42 PM https://youtu.be/WDfZFSay_1A 09-Aug-20 03:59 PM I had a bad air admit solenoid on a Leica S430 SEM. Would get to 1e-4 torr and couldn’t go further. 09-Aug-20 03:59 PM I don’t know the translation of your Pirani voltages to pressure. But this small physical leak was right at the threshold of triggering the HV interlock. 09-Aug-20 03:59 PM In my case, I only had a Penning gauge. It was dirty, which caused it to read a better vacuum than was actually in the chamber. 09-Aug-20 03:59 PM So the HV would energize when it shouldn’t. 09-Aug-20 03:59 PM The system would work but occasionally the vacuum gauge would read the real vacuum and trip the interlock. Cleaning the gauge caused the pressure to display as consistently bad. I bumped the air admit solenoid and saw a significant pressure fluctuation. Replacing it with a rubber stopper temporarily fixed the problem, so I replaced it. 09-Aug-20 04:58 PM @vovchik you may want to check the vacuum with a separate pirani gauge. the existing gauge may be bad. However the DP should be able to get a vacuum well beyond the pirani's range. So your 2.15V reading either means, that the pirani's range end is not reached and the vacuum is bad or that the vacuum is better than measured and the gauge or the measurement amplifier is bad. If the vacuum is indeed bad you either have a leak or an issue with your pumps. What pressure do you have at the inlet of the rotary pump? 09-Aug-20 06:53 PM <𝓕ermion#6024> https://www.ebay.com/itm/MK-9P-Panel-Punch-For-9-Pin-D-Subminiture-RS449-Same-as-DSP-9P-DB9/233313940965?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649 has anyone tried these knockout punches? 09-Aug-20 06:53 PM <𝓕ermion#6024> I can't really justify spending 700 dollerydoos for a greenlee one 09-Aug-20 07:24 PM Do you actually need that strength? 09-Aug-20 07:24 PM Hole saw + waterjet piece is what I would be doing lol 09-Aug-20 07:43 PM <𝓕ermion#6024> I don't have access to the water jet due to covid 09-Aug-20 07:43 PM <𝓕ermion#6024> otherwise I'd absolutely just water jet it. 09-Aug-20 08:29 PM @vovchik since you know thr relevant voltages, it would be trivial to connect the mks 901p to an arduino with a max232 and a RC filter on a PWM line (or the DAC if the Arduino has one) 09-Aug-20 08:29 PM Actually the mks 901p has relay outputs that can be programmed for any setpoint 09-Aug-20 08:39 PM You can pay for waterjetting services 09-Aug-20 08:39 PM I’ve had stuff plasma cut before 10-Aug-20 12:54 AM @analogmultiplizierer thanks for the tips, I ordered an MKS901P gauge to cross check with it, it's going to be here in a week or so. Hope I can figure out a way to mount it in the meantime. What's a good way to test for leaks? If I keep the pumps off and valves closed for several hours, I assume the reading shouldn't change much? 10-Aug-20 12:54 AM @nmz787 good idea on using the MKS901P as the primary gauge. I wasn't able to find the original gauge in a quick ebay search. 10-Aug-20 12:57 AM I use iso/ethanol to check for leaks, myself 10-Aug-20 01:00 AM the maintenance manual for the SEM specifies that the rotary pump vent valve (and only that one) must be disassembled and greased yearly. That valve is supposed to remain open when the SEM is off and closed when it powers on - sounds like the first place to look? 10-Aug-20 09:17 AM <𝓕ermion#6024> anyone know of a good helium compatible check-valve? 10-Aug-20 09:17 AM <𝓕ermion#6024> with a low breaking pressure 10-Aug-20 09:41 AM Nupro/swagelock have little ones. Or used to anyways. I would check with Key High vacuum products. 10-Aug-20 10:42 AM Just beware that swagelock compression fittings are not completely helium leaktight (leak rate for 1/2" fitting is ~ 10^-4 std.cc/s) 10-Aug-20 10:45 AM O.o everyone I know uses the 1/4" stainless ones for 6 orders helium lol 10-Aug-20 10:58 AM Sorry, I misread original question - this is for low/high temperatures. For room temperature it is probably fine... 10-Aug-20 03:42 PM Huh so my 5V regulator is very temperature sensitive 10-Aug-20 03:42 PM as it overheats it drops to 4V quickly 10-Aug-20 08:39 PM <𝓕ermion#6024> anyone know where you get the cables for the PKR 251s? 10-Aug-20 08:39 PM <𝓕ermion#6024> https://www.mouser.com/ProductDetail/Lumberg-Automation-Hirschmann/GO-6-WF?qs=chTDxNqvsym8zPfexmjq7w%3D%3D does this look like the right connector? 10-Aug-20 10:31 PM <𝓕ermion#6024> actually I should ask-- when making ten pin connectors, do you ever strip the insulation far back so you have some room to work with the wires? 10-Aug-20 10:31 PM <𝓕ermion#6024> or LEMO or otherwise 10-Aug-20 10:31 PM <𝓕ermion#6024> it seems like the connector is designed for maybe half an inch of wire to branch out. 10-Aug-20 10:46 PM Usually the datasheet for such things says that, or the product sheet for that series/model-line will have it 10-Aug-20 11:30 PM @𝓕ermion In original datasheet they say "Hirschmann compact connector type GO 6, 6 pins, male", so I would say you have the right one. And yes, those are quite pain to assemble, as space inside is really limited... 10-Aug-20 11:30 PM <𝓕ermion#6024> I'm really quite worried about getting enough room to heat-shrink the wire 10-Aug-20 11:30 PM <𝓕ermion#6024> I guess I'd just hack it and not heat shrink the wire but the shell is metallic and is gonna short all the pins around the outside of the ring together 10-Aug-20 11:30 PM <𝓕ermion#6024> so i just gotta do it right. 11-Aug-20 03:15 AM https://www.mouser.com/ProductDetail/Lumberg-Automation-Hirschmann/GO-6-WF?qs=chTDxNqvsym8zPfexmjq7w%3D%3D does this look like the right connector? @𝓕ermion The picture looks good to me. Is there any high voltage on the connector? The PKR that I have used came with a plastic shell 11-Aug-20 03:15 AM @analogmultiplizierer thanks for the tips, I ordered an MKS901P gauge to cross check with it, it's going to be here in a week or so. Hope I can figure out a way to mount it in the meantime. What's a good way to test for leaks? If I keep the pumps off and valves closed for several hours, I assume the reading shouldn't change much? @vovchik I haven't ever done such a measurement. Maybe the valves will leak while they change. I'd be worried to measure worse then 1 mbar within an hour, but that's just my feeling about it 11-Aug-20 04:02 AM @analogmultiplizierer No, there is only supply voltage (something aroung 20 volts), identification pin (resistor to gnd) and analog output (0-10 volts). It is completely self-running, only power supply is needed... 11-Aug-20 01:17 PM anyone have any recommendations for low-noise (dry) air compressors? ideally something with a tank. i've needed something for pneumatic valve control for a while and all i have is a deafeningly loud oil-free pancake compressor 11-Aug-20 01:17 PM I know 'lab compressors' are a thing, they look like rebuilt fridge compressors a lot of the time 11-Aug-20 01:18 PM because they are 11-Aug-20 01:21 PM :D 11-Aug-20 01:21 PM maybe i just need to trawl fleabay for a cheap jun-air 11-Aug-20 01:21 PM slap a drierite column on it and call it done 11-Aug-20 01:28 PM I do not have personal experience with them but I have had a number of people recommend this company to me: https://www.californiaairtools.com/ultra-quiet-series-of-air-compressor-contractor-grade/ 11-Aug-20 02:29 PM hmm 11-Aug-20 02:29 PM I could get my hands on some parts of an ion implanter that worked with arsine 11-Aug-20 02:29 PM thing is 11-Aug-20 02:29 PM arsenic contaminated cold head 11-Aug-20 02:29 PM yes or no 11-Aug-20 02:29 PM I don't know in what form or how sticky etc 11-Aug-20 02:40 PM Given all the unknowns my gut feeling is a big no...arsenic is not something I would want to possibly contaminate my vacuum hardware stuff even on a low level 11-Aug-20 03:17 PM I'd nab it, but store it in a sealed box while doing research on how to deal with it. 11-Aug-20 03:25 PM just buff it out /s 11-Aug-20 05:18 PM @qualia I've got a California air tools, it's pretty quiet i guess, haven't been around a lot of compressors to know though honestly 11-Aug-20 05:18 PM Got it on Craigslist for pretty decent price, it was seized but simply disassembling and reassembling got it working fine for the years since then 11-Aug-20 05:18 PM Oil free, uses teflon piston seals 11-Aug-20 05:18 PM So i guess be aware that downstream teflon contamination on some level will be present unless filtering well or something 11-Aug-20 11:08 PM hey guys long time no see, got a question 11-Aug-20 11:08 PM 2 things actually 11-Aug-20 11:08 PM well, maybe even 3 11-Aug-20 11:08 PM ok 1 is I'm p sure I've asked this before, but does anyone have a good rec for a reliable starter vacuum pump -- not lookingto draw high vacuum, even 11-Aug-20 11:11 PM Oil-free? 11-Aug-20 11:11 PM I don't plan on using this for any kind of serious experiments, one of the intents is actually auto maintenance 11-Aug-20 11:11 PM ehhhh 11-Aug-20 11:11 PM dealers choice 11-Aug-20 11:11 PM I don't think it needs to be oil free unless there would be a potential to re-introduce oil into the chamber, but I'm admittedly not too familiar. Haven't purchased a vaccuum pump before so its a bit of a gap in my knowledge 11-Aug-20 11:13 PM Oil will go into the vacuum chamber if there is oil 11-Aug-20 11:13 PM Whether it will go in enough for you to care is a whole different question 11-Aug-20 11:13 PM mmm, and if I remember correctly the tradeoff there is usually that oil is cheaper, yeah? 11-Aug-20 11:14 PM The rotary vane design works extremely well, and is very cheap to make, so yeah 11-Aug-20 11:14 PM are there inline filters for dealing with the oil introduction issue? if so, might just go with that 11-Aug-20 11:15 PM Yes, ish. 11-Aug-20 11:15 PM You probably don't care about the small amount of oil, TBH. 11-Aug-20 11:16 PM so, for some context, I wanted to experiment with rapid dessication of food without lyophilizing. I figure the work has already been done in that space but I'm kinda curious about messing around with it and it seems like a fun area for screwing around in 11-Aug-20 11:16 PM (this is not the main use, but it is /a/ use, potentially) 11-Aug-20 11:16 PM and like 11-Aug-20 11:17 PM Oh, I would only use pretty decent gear for food but others are less picky. 11-Aug-20 11:17 PM ingesting pump oil, even in small amounts, is almost certainly not safe 11-Aug-20 11:17 PM yeah 11-Aug-20 11:17 PM @samy did some vacuum food stuff 11-Aug-20 11:17 PM Perhaps that was just with his oily pump though 11-Aug-20 11:18 PM that's kinda what I was afraid of. So, what's the minimum price for a low vacuum oil-less pump? 11-Aug-20 11:19 PM I imagine someone lucky can get a decent scroll pump for a few hundred dollars. 11-Aug-20 11:19 PM I remember way back when I was trying to spec out a lab @ school, the price point was > $1k, but I'm unsure if that's even an accurate memory 11-Aug-20 11:19 PM so, best rec then is to just scope out ebay/CL and see what I can find? 11-Aug-20 11:19 PM (used, but if it's for food you probably care what it was used for...) 11-Aug-20 11:20 PM hmm, true. 11-Aug-20 11:20 PM Are you interested in buying a "sort of broken" one and fixing it? if so you might be able to get a free one from a university. 11-Aug-20 11:20 PM yeah, I live in Boston so there's plenty of lab surplus depending on the time of year. Fall is a surprisingly good time for it because new budgets come in then. 11-Aug-20 11:20 PM although idk what covid will do to that cycle 11-Aug-20 11:21 PM Won some pumps from a government surplus auction for pretty cheap 11-Aug-20 11:21 PM But that's a freak case 11-Aug-20 11:22 PM but this would be a couple months out so its probably best to wait and see anyway. So your advice is to look for a damaged scroll pump, then clean & rebuild it? 11-Aug-20 11:22 PM anyway, thanks, now on to question 2 and 3 11-Aug-20 11:24 PM I don't know if damaged scroll pump is a great suggestion 11-Aug-20 11:24 PM 2 is: what would be the best way to rig up a cheap cooler for a vacuum chamber? would it be better to try to run some kind of chilled water bath through the chamber? or just draw a vacuum on the chamber and jam it in the freezer? 11-Aug-20 11:24 PM yeah, valid. I think maybe the better plan is to just assume that the food idea is a bad one 11-Aug-20 11:25 PM they're precision machines and kinda annoying. Perhaps a diaphragm pump would actually be cheaper! 11-Aug-20 11:26 PM yeah, that sounds like what little I remember. Thanks! This at least gives me material to search when I do eventually dive in on the research 11-Aug-20 11:26 PM and, 3 is if anyone has any microscope bits they don't want and would be interested in selling. Purchased a monster of a microscope that I'm going to be driving 4 hours to pick up later this week. It's an old 100-pound machining microscope. Issue is that optics stuff is expensive and kitting this out is not going to be cheap, so if anyone has any parts they don't want I'd be happy to pay for them 11-Aug-20 11:26 PM (microscope is this big beautiful boi, im very excited) 11-Aug-20 11:26 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/s-l1600-D4C11.png 11-Aug-20 11:26 PM anyway thanks for the input @idmb, I'm going to do a bit of a dive on diaphragm pumps and see what I can find! 11-Aug-20 11:40 PM @hedgeberg scroll pumps are painful to repair if broken. As @idmb said, they are precision machines with lot of interference-fit parts which are hard to disassemble/assemble without proper tooling and manuals. Only serviceable thing is scroll PTFE seal. We tried to change worn out bearings on Edwards nXDS and failed (there are no service instruction) and we also changed main bearings at Agilent/Varian Triscroll (service instructions available) and it required awful amount of work with hotplate, oxy-propane burner and various pullers. And the resulting pressure was still quite poor. If you are going to use diaphragm pump, check before that its pumping speed is sufficient. Those are quite small pumps, usually... 11-Aug-20 11:43 PM I don't really need much in the way of speed, fortunately. I'm ok with a slow pull and a weak vacuum. There's someone near me selling a Rocker 300C, any good? 12-Aug-20 05:41 AM toolmaker's microscope! 12-Aug-20 06:45 AM We replaced the full head of a scroll pump, which was everything except chassis + motor + inlet/outlet tubes and that was something like $1000 CAD, on a pump we had ~10 years prior bought new for ~$4000 CAD. The head replacement was very easy. 12-Aug-20 08:44 AM @Noxz ye! But frankly I'm more interested in the bidirectional lighting + the mofularity + the micrometers 12-Aug-20 08:44 AM Epitaxial lighting = I can convert it into a metallurgical scope for relatively low cost, and that should let me have some fun with getting ultra-hig-res die shots of some chips. 12-Aug-20 09:10 AM Mine 12-Aug-20 09:10 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_1144-8AF96.JPG 12-Aug-20 09:10 AM Fuzzy, argh. 12-Aug-20 10:55 AM Joined the server. 12-Aug-20 10:56 AM hello! 12-Aug-20 10:57 AM Hiya! 12-Aug-20 04:38 PM <𝓕ermion#6024> hey so let's suppose I have some very old system that I'm hooking up to a brand new roots blower 12-Aug-20 04:38 PM <𝓕ermion#6024> and there might be some dust and particulates that have settled on some of the surfaces 12-Aug-20 04:38 PM <𝓕ermion#6024> or even let's just take a pressure gauge that's been sitting in a bin for 5 years 12-Aug-20 04:38 PM <𝓕ermion#6024> and I'm kinda worried about any large particles getting sucked into the roots pump and ruining it 12-Aug-20 04:38 PM <𝓕ermion#6024> is the solution just tons of kimwipes and IPA? 12-Aug-20 04:43 PM That's what I did but also pump it with an old scroll first?.. 12-Aug-20 04:43 PM Water is also not the devil, if you've got real dust 12-Aug-20 04:49 PM <𝓕ermion#6024> oh that's a good idea. 12-Aug-20 04:50 PM for any1 into HV stuff there is a dude trying to organize a big group buy for these epic ferrite cores Two piece double u core with overall dimensions of 150mm by 360mm with a cross section of 50mm by 25mm.2000ui core material relative permiability .500mT saturation at 25*c. Maximum useable core frequency of 500khz Message R-3350#4834 if interested. 12-Aug-20 04:50 PM hes just gauging interest rn to work out a deal with the company 12-Aug-20 05:10 PM <𝓕ermion#6024> hmm is it ok to use a pirani to measure helium pressure? 12-Aug-20 05:10 PM <𝓕ermion#6024> or is there a more appropriate type of gauge 12-Aug-20 05:10 PM <𝓕ermion#6024> seems like there's just a correction factor you have to use 12-Aug-20 05:11 PM The thing about correction factors 12-Aug-20 05:11 PM is nobody seems to bother using them when quoting pressures 12-Aug-20 05:11 PM in chambers that only have helium in them 12-Aug-20 05:11 PM >.< 12-Aug-20 05:13 PM <𝓕ermion#6024> yeah it's a factor of unity anyway so like eh. 12-Aug-20 05:22 PM oh nice 12-Aug-20 05:22 PM ion gauges are like 5x 12-Aug-20 05:22 PM so people will call 2E-4 "about 1E-4" when it's really 1E-3 12-Aug-20 05:24 PM lol how to be an order of magnitude off with one simple step 12-Aug-20 05:29 PM <𝓕ermion#6024> lol oh no. 12-Aug-20 07:34 PM <𝓕ermion#6024> hmm is there some subtlety that I'm not understanding with gauge controllers? 12-Aug-20 07:34 PM <𝓕ermion#6024> it seems like a high res ADC and a microcontroller with lookup table with some interpolation 12-Aug-20 07:34 PM <𝓕ermion#6024> and a display? 12-Aug-20 07:35 PM That's it 12-Aug-20 07:35 PM depends on the kind of gauge for specifics but generally all that yeah 12-Aug-20 07:35 PM FYI a lot of the ADCs must be floating. 12-Aug-20 07:35 PM maybe a setpoint controller 12-Aug-20 07:35 PM <𝓕ermion#6024> ok floating ADC needs a little subtlety 12-Aug-20 07:35 PM <𝓕ermion#6024> but otherwise seems simple enough. 12-Aug-20 07:36 PM They typically throw in extra random features like relays to try and mask the "good ADCs are shockingly expensive" problem 12-Aug-20 07:36 PM heh 12-Aug-20 07:36 PM <𝓕ermion#6024> good ADCs aren't even that expensive though? 12-Aug-20 07:37 PM Not compared to gauge controllers 12-Aug-20 07:37 PM Which gauges / controllers are you looking at ? 12-Aug-20 07:39 PM i wonder if you could use a leak detector in a closed loop as a helium-specific gauge 12-Aug-20 07:41 PM <𝓕ermion#6024> PKR251 12-Aug-20 07:41 PM might make a nice way to calibrate at least 12-Aug-20 07:41 PM I mean, it depends what you consider to be a "good" ADC 12-Aug-20 07:43 PM <𝓕ermion#6024> Most gauge controllers don’t have that many sigfigs. Like maybe you can’t use the onboard ADC but some chintzy SPI thing should be fine right? 12-Aug-20 07:43 PM Umm 12-Aug-20 07:43 PM I've come upsettingly close to purchasing 3 $1200-a-chip ADC's for a work project 12-Aug-20 07:43 PM <𝓕ermion#6024> Did I miss something? 12-Aug-20 07:43 PM We're talking pressure gauges, sig figs are less important than absolute values 12-Aug-20 07:44 PM <𝓕ermion#6024> Oh so you’re talking INL/DNL? 12-Aug-20 07:44 PM accuracy vs precision 12-Aug-20 07:44 PM yeah, ADC noise sensitivity gets to be a real problem when doing sensor design stuff 12-Aug-20 07:44 PM <𝓕ermion#6024> Well ok we can just talk in terms of ENOB 12-Aug-20 07:45 PM It all depends how much you care. I just use an NI USB-6001 for my MKS 972B 12-Aug-20 07:45 PM (Which technically has rs232 but eh) 12-Aug-20 07:45 PM and unfortunately, a shocking number of sensor engineers don't know how to stabilize their outputs 12-Aug-20 07:45 PM I mean you also have to value your time 12-Aug-20 07:45 PM Chomper stabilzation: exists Paid sensor engineers: nah 12-Aug-20 07:46 PM $50 in parts + 20 hours of your time to have 3 working gauge controllers vs one $500 controller that can do all three in a nice package? 12-Aug-20 07:46 PM <𝓕ermion#6024> 50 dollars in parts? 12-Aug-20 07:47 PM I mean, I'm talking about engineers that sell pre-packaged solutions. A lot of pre-packaged solutions are depressing non-performant 12-Aug-20 07:47 PM random example 12-Aug-20 07:47 PM <𝓕ermion#6024> Oh you’re just saying that the usb-6001 is a prepackaged solution 12-Aug-20 07:48 PM Oh sorry by $50 I meant a DIY janky solution 12-Aug-20 07:48 PM <𝓕ermion#6024> Ahh okay. 12-Aug-20 07:48 PM USB-6001 is like $250 but I'm using every single pin on it 12-Aug-20 07:48 PM for my janky PLC 12-Aug-20 07:48 PM fun fact, I accidentally bought active-LOW relays 12-Aug-20 07:48 PM oh that's fun 12-Aug-20 07:48 PM so I had to solder some jumpers to fix that 12-Aug-20 07:49 PM <𝓕ermion#6024> Seems like a nice box! Does it have any kind of isolation from the computer’s ground? 12-Aug-20 07:49 PM USB isn't supposed to attach grounds 12-Aug-20 07:49 PM <𝓕ermion#6024> What would be really nice is one of those boxes with all-differential inputs and full isolation from USB ground/bus. 12-Aug-20 07:49 PM <𝓕ermion#6024> Wait really? 12-Aug-20 07:49 PM a lot of times it does, but its not supposed 12-Aug-20 07:49 PM <𝓕ermion#6024> What is vbus referred to then? 12-Aug-20 07:50 PM the ground is for the 5V 12-Aug-20 07:50 PM I thought 12-Aug-20 07:50 PM The differential inputs are totally floating AFAIK 12-Aug-20 07:50 PM Floating... enough.... 12-Aug-20 07:50 PM yeah, that's the power supply. the twisted pair is floating 12-Aug-20 07:50 PM <𝓕ermion#6024> Ohh sure. 12-Aug-20 07:50 PM but a lot of people connect the shield to the case ground 12-Aug-20 07:50 PM which 12-Aug-20 07:50 PM bad 12-Aug-20 07:51 PM <𝓕ermion#6024> Yeah no. 12-Aug-20 07:51 PM one issue with my PLC box 12-Aug-20 07:51 PM I'm using 24V relays for my gate valves and stuff 12-Aug-20 07:51 PM and just got a random 1A 5V regulator 12-Aug-20 07:51 PM without realizing how they worked 12-Aug-20 07:51 PM 19V*1A = a lot of heat 12-Aug-20 07:52 PM anyway, I need to get back to work on fixing up my car, but before I go, rq @idmb I found this on craigslist and I'm... not totally sure what it even is? https://boston.craigslist.org/gbs/ele/d/dorchester-center-vintage-jsklar/7165454660.html 12-Aug-20 07:52 PM claims to be a vacuum pump? 12-Aug-20 07:52 PM so I just drilled another hole in the box and now my PLC box has two power cables 12-Aug-20 07:52 PM I'm tempted to buy it just to see what it is 12-Aug-20 07:52 PM but I was wondering if you had any idea 12-Aug-20 07:52 PM If it is a vacuum pump, it definitely does not look like one I've ever seen 12-Aug-20 07:53 PM <𝓕ermion#6024> Murata makes these nice little switching regulators 12-Aug-20 07:53 PM <𝓕ermion#6024> They’d do just fine. 12-Aug-20 07:53 PM <𝓕ermion#6024> You can take 24V down to 5V no sweat. 12-Aug-20 07:53 PM <𝓕ermion#6024> 5W... yeah np 12-Aug-20 07:54 PM wait looking at it again, I just realized the plastic tanks are not part of the vacuum forming element, the pump is the part below it 12-Aug-20 07:54 PM and I am a dummy 12-Aug-20 07:54 PM ignore me sorry 12-Aug-20 07:54 PM <𝓕ermion#6024> https://www.digikey.com/product-detail/en/murata-power-solutions-inc/OKI-78SR-5%2F1.5-W36-C/811-2196-5-ND/2259781?utm_adgroup=DC%20DC%20Converters&utm_source=google&utm_medium=cpc&utm_campaign=Shopping_Product_Power%20Supplies%20-%20Board%20Mount_NEW&utm_term=&utm_content=DC%20DC%20Converters&gclid=EAIaIQobChMI_sDW2ZaX6wIVMfC1Ch0J5Ai4EAQYASABEgKeF_D_BwE 12-Aug-20 07:54 PM @hedgeberg my googling says it's a "dental suction pump" with a little rotary vane pump on it ? 12-Aug-20 07:54 PM Oh yeah there are tons of regulators that would work 12-Aug-20 07:54 PM but it's much easier to just add another barrel plug to the front of the already-complete box 12-Aug-20 07:55 PM <𝓕ermion#6024> Drilling a hole is fine too tho lol 12-Aug-20 07:55 PM and plug in two power bricks 12-Aug-20 07:55 PM prolly cant pull much of a vacuum then, huh? 12-Aug-20 07:55 PM <𝓕ermion#6024> When I first got to my new office I noticed that someone had run an Ethernet cord through the wall by hammering a hole through it. 12-Aug-20 07:55 PM <𝓕ermion#6024> No junction box, nothing 12-Aug-20 07:56 PM we have a hole in the wall burned by a laser 12-Aug-20 07:56 PM it has a poster over it. 12-Aug-20 07:56 PM <𝓕ermion#6024> And then someone else had run an Ethernet cord through the radiator 12-Aug-20 07:56 PM Ooof 12-Aug-20 07:56 PM <𝓕ermion#6024> I now try to hold myself to such standards 12-Aug-20 07:57 PM LMK if you're ever in vancouver and I'll show you my mistakes 12-Aug-20 07:57 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-9DED9.jpg 12-Aug-20 07:57 PM here is the front panel of my PLC box, minimal labelling thus far 12-Aug-20 08:08 PM <𝓕ermion#6024> Looks nice! 12-Aug-20 08:08 PM <𝓕ermion#6024> I recently got one of these Brady label makers 12-Aug-20 08:08 PM <𝓕ermion#6024> With tag cartridges and fold-over cable label cartridges 12-Aug-20 08:08 PM <𝓕ermion#6024> It’ll print these non adhesive vinyl labels that hold on using two zip ties, I love them. 12-Aug-20 08:10 PM TBH I prefer the cheap ones 12-Aug-20 08:10 PM <𝓕ermion#6024> Why’s that? 12-Aug-20 08:10 PM our neighbours have one that can print PDFs 12-Aug-20 08:10 PM because I like not thinking about whether to print labels 12-Aug-20 08:10 PM a roll of labels is like $3 when you buy a 10 pack 12-Aug-20 08:10 PM lasts many months 12-Aug-20 08:10 PM some of my cords have labels every 18" 12-Aug-20 08:10 PM more labels = better 12-Aug-20 08:11 PM <𝓕ermion#6024> I’m finding that I think less about making labels with this label maker than when I had a simpler one. 12-Aug-20 08:11 PM I guess the best solution is more label makers 12-Aug-20 08:11 PM <𝓕ermion#6024> Just because the text ends up right where you want it, you know it’ll stay on, etc. 12-Aug-20 08:11 PM <𝓕ermion#6024> I just remember finding SMA cables in drawers with 10 incorrect labels on them because they’re so hard to remove and sticky... and other times I’d put them on and they just wouldn’t stick and would fall off and I’d have to trace the cable through 12-Aug-20 08:13 PM Oh yeah 12-Aug-20 08:13 PM <𝓕ermion#6024> Everyone had their own trick to make the label stick... one guy would put the label on and then wrap the thing with a ton of scotch tape 12-Aug-20 08:13 PM so our lab has a HUGE set of optical tables connected together 12-Aug-20 08:13 PM and one laser setup gets used for experiments at each end of the table 12-Aug-20 08:13 PM <𝓕ermion#6024> Like I just never think about it anymore. The label stays on as long as I want and no longer 12-Aug-20 08:14 PM so we have a serial switch in the middle depending which experiment is using the newport motion controllers 12-Aug-20 08:14 PM some cords are named after grad students who haven't been here for a decade 12-Aug-20 08:14 PM <𝓕ermion#6024> Yeah that sounds right. 12-Aug-20 08:14 PM But these aren't taped on ? 12-Aug-20 08:14 PM they're just the cheap $30 label maker labels 12-Aug-20 08:15 PM <𝓕ermion#6024> Sure... I mean, they do work if you fold them around and make a flag 12-Aug-20 08:15 PM <𝓕ermion#6024> But then the text doesn’t really stay where you want 12-Aug-20 08:15 PM <𝓕ermion#6024> It’s just a little thing 12-Aug-20 08:15 PM Oh 12-Aug-20 08:15 PM <𝓕ermion#6024> I’m just much happier having a fancy label maker lol 12-Aug-20 08:15 PM I don't really care where the text is 12-Aug-20 08:15 PM I just want it to be there 12-Aug-20 08:15 PM <𝓕ermion#6024> Yeah fair enough. 12-Aug-20 08:15 PM <𝓕ermion#6024> I mean I’ve been up on a ladder reaching up at a cable trying to grab at the flag to sorta twist the cable around so I could read it 12-Aug-20 08:15 PM <𝓕ermion#6024> Or like my hand very deep in an optical table sitting on a shelf on a rack trying to read the flag and then bending it around to see what’s on the other side 12-Aug-20 08:17 PM then you should be blaming the cable routing 12-Aug-20 08:17 PM cable trays are a godsend 12-Aug-20 08:17 PM <𝓕ermion#6024> I mean... everything goes out the window near the end of a PhD 12-Aug-20 08:17 PM <𝓕ermion#6024> Also sometimes you’re not really trying to route a cable since it’s not really permanent... and then it turns permanent, and then this is repeated 50 times until you end up in hell 12-Aug-20 08:17 PM <𝓕ermion#6024> And then things work so you can’t mess with it. 12-Aug-20 08:19 PM Oh yeah I make a point 12-Aug-20 08:19 PM that if something is going to be "not permanent" 12-Aug-20 08:19 PM it needs to be extremely in the way 12-Aug-20 08:20 PM <𝓕ermion#6024> I guess everyone has their thing. Explosions&fire has yellow chemistry, I have elaborate labels. 12-Aug-20 08:20 PM I refuse to let things be conveniently inconvenient 12-Aug-20 08:20 PM <𝓕ermion#6024> Everyone has their own way of reckoning with technical debt I guess. 12-Aug-20 08:20 PM <𝓕ermion#6024> I guess there’s just different layers of preparation 12-Aug-20 08:20 PM <𝓕ermion#6024> Like you can do things that are preventative like what you suggested 12-Aug-20 08:20 PM <𝓕ermion#6024> But you can also do things that help you once you inevitably end up in hell at some point. 12-Aug-20 08:22 PM Such as? 12-Aug-20 08:22 PM <𝓕ermion#6024> But ideally you’re minimally in hell because of all the preventative measures you took 12-Aug-20 08:22 PM <𝓕ermion#6024> I mean for me nice labels are one of those things as I described 12-Aug-20 08:22 PM <𝓕ermion#6024> Labels that can be read from any orientation, that go on and come off when I want, etc. 12-Aug-20 08:22 PM <𝓕ermion#6024> Have nicely aligned text 12-Aug-20 08:22 PM <𝓕ermion#6024> It’s just a luxury/comfort thing I guess. 13-Aug-20 10:25 AM Ok so my PLC box seems to be done 13-Aug-20 10:25 AM and communication between PCs is easy enough 13-Aug-20 10:25 AM now... what do I make it do.... 13-Aug-20 10:25 AM If vacuum chamber pressure > 10 bar -> apply for grant for new turbos 13-Aug-20 04:03 PM I just found some centipedes in the lab 13-Aug-20 04:04 PM fry them 13-Aug-20 04:04 PM Oh the concrete bunker I worked in during last summer was full of these miniature centipedes 13-Aug-20 04:04 PM In fact the entire lab was infested 13-Aug-20 04:04 PM Only place without them was in the LINAC target room lol 13-Aug-20 04:04 PM Hopefully they aren't some sort of mutant superbug 13-Aug-20 04:10 PM <𝓕ermion#6024> Yeah that’s the start of a superhero movie 13-Aug-20 04:37 PM https://www.mcmaster.com/db9-cable 13-Aug-20 04:37 PM Why is male-male so much more expensive? 13-Aug-20 04:37 PM Or rather, why is it only available as the expensive "braid, foil" while female-female is available as just foil 13-Aug-20 04:39 PM Because McMaster probably doesn't sell that many DB9 cords? 13-Aug-20 04:39 PM It's not the obvious vendor that comes to mind when you want to buy something like that 13-Aug-20 04:39 PM yes it is 13-Aug-20 04:39 PM I order mcmaster I get tomorrow 13-Aug-20 04:39 PM I happy 13-Aug-20 04:39 PM University life... 13-Aug-20 04:40 PM unfortunately as I need five of them 13-Aug-20 04:40 PM the price inflation is not quite justifiable here 13-Aug-20 04:40 PM but I can get normal cables and male-male adapters so yay? 13-Aug-20 04:53 PM Ok... how do I remove this first 3 armed thing (the one above the first rotor no clue on the name) from the stack? 13-Aug-20 04:53 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-FBE65.jpg 13-Aug-20 04:56 PM What pump is that? TPD 020? 13-Aug-20 05:00 PM TMH 260 13-Aug-20 05:00 PM Pfieffer 13-Aug-20 05:07 PM I think you'd have to lift out the entire shell as one piece... Have you looked at the bottom bearing yet? 13-Aug-20 05:07 PM The stators are probably in rings that interlock with each other, not the shell 13-Aug-20 05:07 PM Can you take a side view picture of the pump? 13-Aug-20 05:21 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-C040C.jpg 13-Aug-20 05:21 PM Flange is off, I can actually pull that three arm piece off it just was tight in place 13-Aug-20 05:21 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-FE00C.jpg 13-Aug-20 05:23 PM They probably have a special tool for pulling that thing. Unlike edwards, they didn't provide convenient threaded holes on top 13-Aug-20 05:23 PM On later Pfeiffer turbos, those spokes are part of the outermost shell 13-Aug-20 05:24 PM Yeah I learned about Pfeiffer turbos being tricky to repair after I got this one 13-Aug-20 06:18 PM Well got 2 of the stators out now I’m stuck 13-Aug-20 06:26 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-2E309.jpg 13-Aug-20 06:26 PM This one is giving me trouble 13-Aug-20 06:26 PM has blades on both sides and sits on a lip so it won’t slide out easily 13-Aug-20 08:30 PM I CNC machined a tool to engage the holes on top of the Edwards turbos. 13-Aug-20 08:30 PM Never disassembled a Pfeiffer. 13-Aug-20 08:52 PM <𝓕ermion#6024> What CNC do you have? 13-Aug-20 09:56 PM I learned on a Fadal VMC4020. 13-Aug-20 09:56 PM That is in a space no longer accessible for us to use. 13-Aug-20 09:56 PM We need to move it to a different location . 13-Aug-20 09:56 PM I’m now using another makerspace’s Tormach 1100 series.... 13-Aug-20 09:56 PM I’m... kind of disgruntled about it. I told the makerspace not to buy it, save some more and get a Haas. They didn’t listen. 13-Aug-20 09:56 PM It uses steppers, not servos. It’s not as rigid. Doesn’t have a lot of horsepower. And it can’t do rigid tapping. 13-Aug-20 09:56 PM They don’t have any kind of tapping heads, although I think you might be able to get tension/compression heads for that machine. 13-Aug-20 10:12 PM <𝓕ermion#6024> I hate tormach, man 13-Aug-20 10:12 PM <𝓕ermion#6024> I don’t understand how they’ve gotten so popular. 13-Aug-20 10:12 PM <𝓕ermion#6024> They’re not very good at all 13-Aug-20 10:12 PM <𝓕ermion#6024> I’ve been using a 770. On the head there’s a door you open to do tool changes, as well as a small cutout in the lid for the head to poke through 13-Aug-20 10:12 PM <𝓕ermion#6024> If you leave the door open and drop the head you bend the door and ruin the lid 13-Aug-20 10:12 PM <𝓕ermion#6024> There’s a bloody switch on the door to prevent the motor from coming on if the door is open 13-Aug-20 10:12 PM <𝓕ermion#6024> You’d think the controller would be smart enough to not drop the head if the door is open, but no 13-Aug-20 10:12 PM <𝓕ermion#6024> So every 770 out there probably has that door bent to hell 13-Aug-20 10:12 PM <𝓕ermion#6024> I think the hinges are welded in so you can’t replace the door without replacing that whole top piece. It’s really nasty. 13-Aug-20 10:47 PM We don’t have that door problem on the 1100 14-Aug-20 07:15 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200814_161411-58127.jpg 14-Aug-20 07:15 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200814_161430-B23DB.jpg 14-Aug-20 07:15 AM this is what rotary vane oil is supposed to look like, right? 14-Aug-20 07:16 AM ¯\_(ツ)_/¯ 14-Aug-20 07:18 AM forbidden cola 14-Aug-20 08:20 AM That depends. Generally though, no... that looks pretty dirty. I have seen dark oil when new like that before but most of it now is pretty light in color. I would say it’s time for a flush and refill. 14-Aug-20 08:28 AM that's what I'm doing right now ^^ 14-Aug-20 08:28 AM rotary vane and the oildiff behind it 14-Aug-20 09:09 AM https://www.youtube.com/watch?v=8mOwECwVq8s 14-Aug-20 09:30 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200814_175604-977B6.jpg 14-Aug-20 09:30 AM flushing oil 14-Aug-20 09:30 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200814_182022-49761.jpg 14-Aug-20 09:30 AM flushing oil after an hour 14-Aug-20 12:07 PM gnarly 14-Aug-20 12:09 PM this is the result 14-Aug-20 12:09 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/EfZqHIZWkAAFBJf-1533D.png 14-Aug-20 12:09 PM the oildiff also got a few ml oil, but I did not change that completley 14-Aug-20 12:34 PM that's better ^^ 14-Aug-20 03:26 PM Amused at the chunky fuses in the YAG 14-Aug-20 03:26 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-001D9.jpg 14-Aug-20 03:26 PM Scale isn’t super obvious but they’re about 1.5cm OD 14-Aug-20 07:24 PM PHAT PHUSES 14-Aug-20 09:20 PM Pretty Hot And Tripping 14-Aug-20 09:20 PM Actually IDK if fuses trip, like a breaker does 15-Aug-20 09:07 AM in my language fuses blow 15-Aug-20 09:45 AM Chonk. 15-Aug-20 11:28 AM My "PLC" box seems to pass all tests... So now I actually have to program what I want it to do >.< 15-Aug-20 01:51 PM Is it actually using ladder logic??? 15-Aug-20 01:52 PM no 15-Aug-20 01:53 PM Good 15-Aug-20 01:53 PM it's software 15-Aug-20 01:53 PM Ladder logic is horrible IMO 15-Aug-20 01:53 PM It was just a bandaid for people who couldn't deal with archaic languages I guess 15-Aug-20 01:53 PM But luckily we don't really need to deal with anything worse than C these days 15-Aug-20 01:54 PM labviewwwwwwwwwwwwwwwwwwww 15-Aug-20 01:55 PM Ewwwwww 15-Aug-20 01:55 PM IMO that is worse than C. 20 years ago me would have been fine with it though 15-Aug-20 01:55 PM (started with the lego version of labview at the same time as I started C) 15-Aug-20 01:56 PM we learned ladder logic in school for PLC stuff - didn't find it that bad 15-Aug-20 01:56 PM and besides, we've been using ladder logic for quite a while, even before PLCs? 15-Aug-20 01:56 PM to describe relay connections, etc 15-Aug-20 01:56 PM I just see it as keeping with what people are used to already for a long while 15-Aug-20 01:58 PM My only experience learning it existed was when I had to replace a PLC in a spincoater... Or maybe I was only considering replacing it, the found the screw terminals were the only issue 15-Aug-20 01:58 PM ah 15-Aug-20 01:58 PM ngl though - I do feel that pure microcontroller systems are being used more and more in industrial stuff 15-Aug-20 01:58 PM STM32s for example have features for motor control, lighting, etc applications 15-Aug-20 01:58 PM with emergency stop inputs for timers, etc 15-Aug-20 01:58 PM oh cool 15-Aug-20 01:58 PM https://www.fultek.com.tr/en/speed-plc/ <-- there's software that can be used to turn Raspberry Pis and STM32s into PLC sort of devices 15-Aug-20 01:58 PM programmed in ladder logic, etc 15-Aug-20 03:19 PM Hi, I'm fairly new here. I'm looking for a relatively inexpensive Pfeiffer TCP 121 controller for a tph 330 turbo. I was wondering if there's anyone here who might be willing to sell one in working condition for ~$150USD. Thanks! 15-Aug-20 03:21 PM stares longingly at the pair of them in the storage closet 15-Aug-20 03:21 PM Unfortunately academia prefers hoarding till scrap. 15-Aug-20 03:22 PM Tough break. Any chance I might be able to rent/borrow one? I probably only need it for a month or two 15-Aug-20 03:23 PM If you’re in Vancouver BC yes otherwise no 15-Aug-20 03:25 PM Would it make any difference if I covered shipping and the likes? I'm in New England 15-Aug-20 03:27 PM I think you should be able to snag one for less than that, tbh 15-Aug-20 03:29 PM I've tried eBay and Amazon. Any advice on other places to look? 15-Aug-20 03:32 PM Random auction sites and eBay, idealvac maybe?.... 15-Aug-20 03:32 PM Also having a list of all compatible controllers so you can search them all is logical 15-Aug-20 03:37 PM Did you try making an offer on any of the eBay listings? 15-Aug-20 03:37 PM Looks like it's compatible with Pfeiffer TCP 121 (PMC01475 / PN06831), TCP 300 (PMC01259 / PN00341), TCP 310 (PMC01520 / PN06829), and TCP 380 (PMC01490 / PN06827) controllers 15-Aug-20 03:37 PM @LRM Yes, but with very little luck 15-Aug-20 03:37 PM Most people either started way too high for the algorithm to accept my price as serious (flat out rejected the query) or the seller claimed their price was too reasonable to negotiate, even though it was in the $200-$400 range 15-Aug-20 03:41 PM Flat out rejects are set up by the sellers afaik but either way that is unfortunate. I have had good luck with making offers on that sort of thing in the past. Sometimes it just takes patience to find a seller willing to work with you 15-Aug-20 03:44 PM I think sellers still get notified for flat out rejects - I've seen many come back to me with offers subsequently 15-Aug-20 03:44 PM https://www.fultek.com.tr/en/speed-plc/ <-- there's software that can be used to turn Raspberry Pis and STM32s into PLC sort of devices @SleepyOwl Joyce MachineKit/LinuxCNC also include a ladder logic interpreter, and are both well tested and well supported. https://www.machinekit.io/docs/ 15-Aug-20 06:17 PM Quick follow up: I was offered a TCP 121 turbo controller for $180 USD (covers shipping, tax, etc.). Since I don't have months to scour eBay, is this a good price? Thanks 15-Aug-20 06:21 PM Any guarantee it works? 15-Aug-20 06:24 PM eBay, they say they just took it from a fully operating pump 15-Aug-20 06:24 PM It's a 100% positive seller with +30 reviews 15-Aug-20 06:24 PM @idmb 15-Aug-20 06:26 PM Then I mean that price is "good enough" if you really just need it, I'm sure they pop up for $50 now and then but the only other alternative to guarrantee one in the next week is quite a bit more isn't it? 15-Aug-20 06:34 PM Sadly this seems to be the best deal I've been able to find. A good friend of mine said he'd check his warehouse Monday for a spare, but I'm not super confident about it. Until then I asked the seller to freeze the deal, however I might go with his offer should my friend's endeavor not pan out. It should be noted that retail prices can be around $1500-$2500 15-Aug-20 06:34 PM Ofc I'm very new to vacuum tech so my idea of a good markdown for a used item is fairly flimsy 15-Aug-20 07:24 PM $180 seems pretty cheap 15-Aug-20 07:24 PM Yeah maybe if you know ALL the compatible models and are crosschecking ALL of them, then maybe $50 once in a while, but I'd say that is far from common and especially so if you only just know one or two model numbers to check 15-Aug-20 08:04 PM $130 for a "just buy it now" tax over "oh yeah over a 9 month period there are occasionaly some cheap ones" is well worth it 15-Aug-20 08:04 PM $180 is a "if you need it, buy it!" price 16-Aug-20 08:47 AM I’m not sure what to think about that Speed Plc... 16-Aug-20 08:47 AM I thought the whole point of a PLC was high reliability that you could trust for life and safety systems. 16-Aug-20 08:47 AM But a RasPi running Linux??? 16-Aug-20 08:49 AM @rdpierce sort of. Remember is most cases it’s “no PLC vs bad PLC vs good PLC” 16-Aug-20 08:49 AM And uh, most of us have the “no PLC” option 16-Aug-20 08:49 AM My PLC is designed around shutoffs only, no engagement. 16-Aug-20 08:50 AM Ehh, but just using an Arduino, or a Pi and programming it in the language of your choice, is possible too. 16-Aug-20 08:50 AM To try and make it objectively better than “no plc” 16-Aug-20 08:51 AM I figure one only uses a PLC when they actually view ladder logic as a benefit, e.g. they need to prove safety and operational characteristics. 16-Aug-20 08:55 AM Again I think this is where the quotes come back out 16-Aug-20 08:55 AM “PLC” 16-Aug-20 08:55 AM It’s just a system to make decisions of “oh, a forevacuum pump is sending an error signal? Trigger a safe shutdown of everything connected to it” 16-Aug-20 08:55 AM Not because we expect anything catastrophic to happen if it just shuts off 16-Aug-20 08:55 AM Just.... in case & to prevent surprises 16-Aug-20 09:26 AM also, I would think that a tool to help with learning, etc for cheap would be great 16-Aug-20 10:19 AM hi 16-Aug-20 11:24 AM When you get into real industrial applications you don’t find raspberry pi’s out there. They don’t have the temp range. Now as far as embedded Linux boxes they are out there. There are stripped down Linux distros running things everywhere but in reality most really important thing a out there are running on legacy SLC500 type systems or genuine industrial PC type products, or modern high reliability dedicated PLC’s 16-Aug-20 11:24 AM I have seen companies roll their own pi type designs with their own in house built Linux, but that’s a different story. 16-Aug-20 11:33 AM If you want reliability and verifiability, I think PLC is probably not the modern option a Computer Scientist would tend to 16-Aug-20 11:33 AM Probably something more like Rust 16-Aug-20 11:39 AM unfortunately - bare metal Rust isn't that well supported yet 16-Aug-20 11:39 AM especially on many embedded platforms 16-Aug-20 11:44 AM Well certainly verilog is 16-Aug-20 11:44 AM And there's a ton of verification for that 16-Aug-20 11:45 AM yeah 16-Aug-20 11:45 AM that's if you want to go the programmable logic route instead of using a microcontroller/microprocessor 16-Aug-20 11:45 AM at work - we wanted to use Rust orignally for the second revision of our controller electronics 16-Aug-20 11:45 AM turns out MIPS isn't officially supported on Rust yet 16-Aug-20 11:45 AM and then with all the libraries from the hardware vendors we use being written in C (I'm aware that Rust can interop with other languages), etc 16-Aug-20 11:45 AM we're like - meh not worth the hassle for now 16-Aug-20 11:45 AM just do everything in C 16-Aug-20 01:32 PM you can also get extra reliability by using multiple cheap/consumer-grade computers in parallel, say 2 RPis running the same code each with its own relay in series 16-Aug-20 01:32 PM for very simple applications such as "check these 5 sensors and drive this output low for 3 seconds if it's out of range", the programming language doesn't make that much of a difference: there just isn't that much code that you can't test it exhaustively, and not a lot of room for bugs. What does matter is all other code that's also running on the system (hundreds of megabytes of C in the Linux kernel vs nothing else on a simple microcontroller) and hardware reliability (how many power supplies with tight constraints does a Pi have? they once had a problem where a photographic flash would reboot them) 16-Aug-20 01:36 PM I wouldn't be so sure increasing reliability simply by multiplying controllers is good idea... 16-Aug-20 01:36 PM so if you want reliability at all costs, C/C++ on bare metal micros is your best bet (especially on "safety" grade micros like the TMS570 https://processors.wiki.ti.com/index.php/Category:TMS570, which have multiple identical CPUs with cross-checking of outputs on every clock cycle) 16-Aug-20 01:37 PM If you want fail-safe system, I would stick with automotive stuff like MISRA and ASIL norms... 16-Aug-20 01:37 PM @bkralik depends on the circumstances, but https://mjtsai.com/blog/2020/06/04/software-engineering-within-spacex/ is one example how one could build highly reliable systems out of commercial hardware (and often software too) 16-Aug-20 01:37 PM there are multiple ways to accomplish the same goal though - automotive stuff is clearly very safe too 16-Aug-20 01:37 PM it also helps to think what failure rate is acceptable: for a safety shutoff that has a 1% of ever triggering in its lifetime, maybe even 99% reliabiilty isn't bad 16-Aug-20 01:37 PM you're reducing the chance of the whole system failing because of pump failure from 1% to 0.01% 16-Aug-20 01:37 PM and with "bigger" platforms like Linux on an RPi you get convenience features for free - like you can ssh/scp your binaries onto them, use languages like Python with no constraints, plug in HDMI monitors, put it on the network etc.. 16-Aug-20 02:18 PM one last thought on high-reliability systems: if all you really need is a simple interlock, discrete logic chips are still being made and sold. You can't have bugs in code if there's no code, and they are much less sensitive to bad power than a RPi is. The downside is you can't change the logic without a soldering iron. 16-Aug-20 02:25 PM Actually many applications still assembly on micros is the only acceptable thing. 16-Aug-20 02:27 PM assembly? whoa. Is it because of fear of compiler bugs? 16-Aug-20 04:06 PM I wouldn't be so sure increasing reliability simply by multiplying controllers is good idea... @bkralik It's only a little more than that. In an 1 out of 2 (1oo2) architecture multiple controllers are used. The controllers can supervise each other and return the system into a safe state if an error is detected. A friend of mine has used Rust on a STM32. I think that is a very neat way for embedded applications where issues like stack overflows must under any circumstances be avoided. Ultimately, regardless of the programming language used, testing is required to get a known safe system. Behavior under any state at any input must be safe and any undefined state must not occur or lead to a safe state. So it's not just a question of programming language or technique, as the code/ circuit may be faulty 16-Aug-20 06:14 PM No. It’s because people on that level just prefer doing it that way. Much more efficient and control over everything. 16-Aug-20 07:39 PM Intel memory training (in the BIOS, run on startup (unless you have fastboot enabled), run regularly to re-train analog characteristics against thermal drift) is coded in C with hand-optimizations in assembly 16-Aug-20 07:49 PM Ultimately, regardless of the programming language used, testing is required to get a known safe system. Behavior under any state at any input must be safe and any undefined state must not occur or lead to a safe state. So it's not just a question of programming language or technique, as the code/ circuit may be faulty @analogmultiplizierer yeah - not just a question about language - it is possible to put a Rust program into an unsafe state 16-Aug-20 07:49 PM thing is that our controller connects to the internet, and while it isn't mission critical of any sort 16-Aug-20 07:49 PM we still do get into weird states because of connection failure, or a lock failure, etc 16-Aug-20 07:49 PM and I'm going to admit - we never really took care of when that happens 16-Aug-20 08:38 PM Ehh, I don’t know if I’d say that about language. 16-Aug-20 08:38 PM The beauty of ladder logic is that you can make absolute statements. 16-Aug-20 08:38 PM It is obvious that if this interlock opens, that motor loses power. 16-Aug-20 08:38 PM The trouble with programming languages is that, typically, you have to write code to poll. Yes, you can demonstrate that when the code runs, if it finds the interlock is open, then the motor will be stopped. 16-Aug-20 08:38 PM What guarantees that this code will ever run? 16-Aug-20 08:38 PM What if something else gets in an infinite loop and that code doesn’t run? 16-Aug-20 08:38 PM Or what if there’s a 30 second delay somewhere else in the code? And the interlock is opened, but the motor doesn’t stop immediately because of the delay. 16-Aug-20 08:46 PM solution: two PLCs in parallel with an OR gate on every relay 16-Aug-20 08:46 PM in parallel with another pair, joined with an AND gate 16-Aug-20 08:46 PM BAM, requires two failures or two false positives 16-Aug-20 08:48 PM This is reminding me of the research I did on the Saturn V LVDC. 16-Aug-20 08:48 PM They had triple redundant logic and voters so 2/3 agreement gets passed to the next computation stage. 16-Aug-20 09:00 PM I mean w.r.t PLCs, it seems like the innards is still some MCU/MPU 16-Aug-20 09:00 PM https://www.eevblog.com/forum/chat/i-would-love-to-see-a-teardown-of-an-industrial-plc/ 16-Aug-20 09:00 PM so I would reckon there's still a conversion from ladder logic to something that the MCU/MPU can work with 16-Aug-20 09:00 PM so still code 16-Aug-20 09:14 PM I wonder if there's a PLC that uses a CPLD or something similar instead of a MCU 16-Aug-20 09:17 PM I believe many (if not all?) of them do 16-Aug-20 09:17 PM they certainly don't run the logic on the same processor that handles network comms 16-Aug-20 09:17 PM actually I take that back, I saw a disassembled S7-1200 once and there was no CPLD or FPGA in there 16-Aug-20 09:17 PM you can be sure though that the code they run is reeeeally well tested 16-Aug-20 09:17 PM there are also safety-rated PLCs 16-Aug-20 09:19 PM I was under the impression it was mostly MCUs and MPUs than PL devices 16-Aug-20 09:19 PM at least based on the teardowns I've seen 16-Aug-20 09:20 PM I confused them with https://www.ni.com/en-us/shop/compactrio.html, which do use FPGAs 16-Aug-20 09:20 PM and besides - I would think that as you said, the code is really well tested and checked to ensure reliability 17-Aug-20 06:18 AM Yeah. That is the irony behind ladder logic. It’s supposed to run instantaneously, as it was originally implemented by relays. But procedural logic typically needs to interpret it in modern PLCs. 17-Aug-20 06:18 AM Still, that procedural logic is typically very well tested. 17-Aug-20 06:18 AM And is running pretty darn close to bare metal. 17-Aug-20 06:18 AM The RasPi part that worried me the most was that it was still running Linux. 17-Aug-20 06:18 AM If the kernel hangs for some reason, or starves the PLC process of resources, then my fear is it won’t catch critical changes and perform critical actions. This isn’t an issue for a non-critical system. But if any safety issues are on the line, then it’s more critical. 17-Aug-20 06:25 AM Of course - if you were designing a mission critical application 17-Aug-20 06:25 AM I would hope you're not using consumer grade SBCs for this 17-Aug-20 06:25 AM besides - vanilla Linux really isn't meant for mission critical stuff 17-Aug-20 06:25 AM but if you were using a Raspberry Pi for learning, etc 17-Aug-20 06:25 AM then I think that software would be okay 17-Aug-20 06:42 AM For learning, yes.... it’s just that I don’t see many people wanting to use PLCs unless their application has reliability / provability / safety implications. If someone simply wants to control actions happening in sequence, and there aren’t severe implications if something fails, then an Arduino is probably far easier. So it seems... strange... that people would make PLCs available on platforms that really aren’t fit for purpose for anything other than training, learning, and prototyping. 17-Aug-20 06:42 AM On a similar note, I remember at an EPICS conference that one person presented on using EPICS to control a radiation therapy machine, including communicating radiation dose information, where a mistake could be lethal. 17-Aug-20 06:42 AM It seemed like a lot of people’s jaws fell open at that. 17-Aug-20 06:46 AM EPICS as in Experimental Physics and Industrial Control System? 17-Aug-20 06:54 AM @rdpierce A lot of equipment is very ready to connect to cheap premade PLC systems but would require in-house fiddling to use an arduino. 17-Aug-20 06:55 AM Interesting. In what way? 17-Aug-20 06:55 AM I bought much of it is digital off/on. 17-Aug-20 06:56 AM So take a pneumatic gate valve 17-Aug-20 06:56 AM The default VAT ones have a 24V connection to open and close them 17-Aug-20 06:56 AM and then two pairs of wires for indicators for open or closed 17-Aug-20 06:57 AM I did once look into the problem of analog control. The 4-20 mA systems are concerning. 17-Aug-20 06:57 AM Their UHV ones are just open / closed circuits, but the other ones are some PNP bias thing. 17-Aug-20 06:57 AM If you go with a consumer PLC, you just buy the stuff for that type of conenction. DIY you have to make a box like I did 17-Aug-20 06:57 AM (And you need the 24V relays and 24V PSU and all that) 17-Aug-20 06:59 AM With my beer system, I had to use level shifter boards. 17-Aug-20 06:59 AM I was using 12V relays and valves. 17-Aug-20 06:59 AM And an Arduino Mega that was 5V. 17-Aug-20 07:00 AM The 8-relay board I got is nice, triggered with 3-24V and powered by a separate 5V supply, can run the relays at something like 30V/1A I believe. 17-Aug-20 07:00 AM The one downside being it was LOW-active, but bypassing the optocouplers fixed that 17-Aug-20 07:00 AM My NI USB box is 3.3V logic, but accepts 5V inputs. Convenient. 17-Aug-20 07:13 AM I would say biggest "pro" of using some industrial PLC are the standards. Industrial 24V logic is quite standardised (there are IC specially designed to interface those), same with RS485, profinet, modbus and all other suff. If you are in commercial sphere, it is much more convenient to just buy PLC CPU and some needed PLC interface modules, connect it all together with other commercial stuff and you are ready to go. For example at my work, I got a task to make simple "commander" for two Festo servo controllers. I used ESP8266 because I thought it would be easy (just bit of arduino and I am done, no?). In the end, It took me ~ 3 iterations to design reliable board, which included optocouplers for level conversion to 24V, battery backed RAM to save actual position of that manipulators and IO expander to have enough IOs. If I use PLC, it woould have cost much more in "hardware", but it would be "plug and play"... 17-Aug-20 07:14 AM ^ and you get all the easiness by buying a "bad / unreliable" PLC 17-Aug-20 07:58 AM and here I am working on an albeit not mission critical controller system for work 17-Aug-20 07:58 AM they are making me use this lol 17-Aug-20 07:58 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/maxresdefault-2504A.png 17-Aug-20 07:58 AM Some MediaTek MIPS based platform 17-Aug-20 07:58 AM it runs OpenWRT Linux 17-Aug-20 07:58 AM If I could spin my own board to my own will - I'd just toss in a STM32 17-Aug-20 07:58 AM But of course - My superiors doesn't want to deal with baremetal stuff 17-Aug-20 07:58 AM "If your code can do things from userspace - why not?" 17-Aug-20 07:58 AM Unfortunately we gotta do it the lazy way - no say about this from me 17-Aug-20 07:58 AM How lazy are we talking here? 17-Aug-20 07:58 AM Welp they don't even want me to design the power regulation stage 17-Aug-20 07:58 AM just slap in some SMPS module that is meant to replace those 3 pin LM78xx regulators 17-Aug-20 07:58 AM done 17-Aug-20 07:58 AM "Why design our own SMPS circuits?" 17-Aug-20 08:03 AM my "PLC" - windows 10 running labview 17-Aug-20 08:03 AM non-networked of course 17-Aug-20 08:04 AM That being said... there are a scary number of networked control systems 17-Aug-20 08:04 AM exposed to the net 17-Aug-20 08:11 AM Mine is gonna be connected via serial to a networked computer 17-Aug-20 08:20 AM I see 17-Aug-20 08:25 AM @SleepyOwl Joyce yes, that EPICS. 17-Aug-20 08:25 AM It’s seeing some use by people on this server because it’s a free way to use Canberra ADC / AIM NIM modules without having to shell out a lot of money for Genie2k. 17-Aug-20 08:25 AM I also adapted EPICS to brew beer. 17-Aug-20 08:28 AM heh 17-Aug-20 10:35 AM I’m personally convinced that used Canberra NIM gear + EPICS is the best deal possible for spectroscopy. 17-Aug-20 10:35 AM Most modules are available for <$100 on eBay if you look. 17-Aug-20 10:35 AM I think it’s because most people think it’s a boat anchor without a Genie2k license. 17-Aug-20 10:35 AM Things like 8k channels, 100 MHz ADC, actual dead time calculation, pulse pileup rejection if using a Canberra amp... It beats the living daylights out of a sound card. 17-Aug-20 11:31 AM I often forget just how quiet a properly working scroll pump is 17-Aug-20 01:03 PM Heh, I networked my FIB a few months back, used remote desktop to copy some files from it last night, haven't actually tried imaging with it remotely yet... Mainly because the zoom/focus/stigmation controls are non-GUI controls (a separate controller that interfaces over serial I believe) 17-Aug-20 01:03 PM Need to make an interposer for that and network it too, then I can FIB from the comfort of my couch :P 18-Aug-20 08:09 AM New MCP assembly quote €11,000 hype 18-Aug-20 09:33 AM 18 hours after opening to atmosphere, back to 9E-9 on a fairly large poorly-designed chamber 18-Aug-20 09:33 AM (poorly-designed as in there are a ton of virtual leak spots) 18-Aug-20 12:21 PM Also lol another lab has six spare welch pumps and five in operation 18-Aug-20 03:49 PM Okay I made a tool to grab grab/lift the rotor stack off of that pfieffer pump but I can’t get it to budge... Pulling with a decent amount of force but it won’t pull apart 18-Aug-20 03:49 PM tool screws into these slots and then I am pulling upward on the stack... I can’t think of any other way it’d come apart 18-Aug-20 03:49 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-BE43D.jpg 18-Aug-20 03:54 PM Recently got a hold of a Pfeiffer Omnistar GSD 300 atmospheric gas analyzer (just a prepumped rga) with a Prisma QMS 200 quad mass analyzer inside, but finding the Talkstar/Quadstar 422 software for it is entirely impossible. Anyone here have any advice/maybe a copy laying around? 18-Aug-20 03:54 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200816_002051-7F2E5.jpg 18-Aug-20 03:59 PM What happens if you email pfeiffer? 18-Aug-20 04:16 PM No response, and I've waited a couple of weeks now. It's just basic interfacing software, but I'm guessing it's rare and old enough that nobody has bothered to put anything up online. Communications manual for the RGA is also hard to get. Pity, it's a really nice system inside, membrane pump, turbo, universal ionization/pirani gauge and 1-300amu rga along with baking pads and heated capillary that can sample from above ambient pressure. 18-Aug-20 04:25 PM Any luck getting software for a newer version and trying that? 18-Aug-20 04:25 PM Leybold only has software for certain models but it works on most lol 18-Aug-20 05:25 PM @hanstj find you local sales rep 18-Aug-20 05:25 PM The guy around here offered to loan me a pumping station the first time i spoke with him on the phone 18-Aug-20 05:25 PM And I was"only" inquiring about availability of some old oil and maybe a bearing for an older drag pump 18-Aug-20 05:30 PM @idmb No, sadly, the only thing existent online are references in bootleg manuals here and there @nmz787 that's a good point, haven't tried contacting them yet. Also, damn 18-Aug-20 05:58 PM so I ordered a bunch of these things 18-Aug-20 05:58 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/HTB1WAkAXsvrK1Rjy0Feq6ATmVXaj-7E542.png 18-Aug-20 05:58 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/H0a945f09b42e47a3875536936f7562bcd-0FB6A.png 18-Aug-20 05:58 PM I wonder what the ripple on these things would be like 18-Aug-20 05:58 PM these are supposed to give -7kV +/- 1kV 18-Aug-20 06:08 PM Cute! Self-exiting Flyback and a bipolar Cockroft-Walton stage? I'd guess pretty flat 18-Aug-20 06:09 PM I don't know 18-Aug-20 06:09 PM just using this for a photodetector tube's photocathode bias 18-Aug-20 06:09 PM It'd be my guess at least, cheapest and most common config for these kinds of supplies. 18-Aug-20 06:09 PM yeah - that's what some people reckon 18-Aug-20 06:12 PM Rather good at no load if you have external linear feedback to tweak input voltages, but they have horrible output impedance and near linearly worsening noise characteristics with loading Will probably do fine for a photocathode driver though. 18-Aug-20 06:13 PM I will do some measurements of these things, perhaps design some sort of feedback circuit, we'll see 18-Aug-20 06:13 PM right now I am thinking about the amplifier/photon counting electronics 18-Aug-20 06:16 PM OO, funzies! High gain transimpedance amp? 18-Aug-20 06:16 PM yeah, but then again I am looking at the output waveform of this 18-Aug-20 06:16 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-C4124.png 18-Aug-20 06:16 PM as given by the datasheet 18-Aug-20 06:16 PM that's... a pretty fast signal 18-Aug-20 06:16 PM I am lucky that my HP 54615B can do timebases down to 1 ns 18-Aug-20 06:21 PM Yeah ouch, only specialized integrated communications TIA's go that fast, and they're not exactly metrology grade. Could imagine you could cobble together a pretty good semi-wideband first stage with some GaAs HEMT's, they go pretty cheap for high f_t's, have great noise figures and aren't that bad to stabilize. 18-Aug-20 06:23 PM also, if I am pushing the limits of a 500 MHz scope 18-Aug-20 06:23 PM maybe time to think about 1 GHz stuff 18-Aug-20 06:24 PM Yeh, rfland is always fun, especially when your gear can barely keep up. I am forever grateful to the gods of garbage that i have a 6GHz VNA and 20Ghz sampling scope at home, makes this kind of stuff sooooo much easier. 18-Aug-20 06:28 PM <𝓕ermion#6024> yeah honestly I haven't found RF intrinsically hard so much as very delicate and expensive. 18-Aug-20 06:28 PM <𝓕ermion#6024> once you have a specan and VNA and some understanding of maxwell's laws it's a lot of the same themes over and over 18-Aug-20 06:28 PM <𝓕ermion#6024> not to say there aren't brilliant solutions to hard RF problems 18-Aug-20 06:28 PM <𝓕ermion#6024> it's just not black magic like some people think it is 18-Aug-20 06:29 PM @hanstj lucky! :P 18-Aug-20 06:29 PM RF is just tedious lol 18-Aug-20 06:29 PM Understanding what affects RF signals in circuitry, propagation, etc is actually fairly simple imo 18-Aug-20 06:29 PM Designing the circuitry themselves 18-Aug-20 06:29 PM Laying the PCBs, etc 18-Aug-20 06:29 PM That's the fun part 18-Aug-20 06:29 PM I was having a discussion with my company's CTO about PCB material at higher frequencies/data rates 18-Aug-20 06:29 PM The board material can and does get expensive quick 18-Aug-20 06:33 PM <𝓕ermion#6024> it's quite impressive how fast you can push FR4 depending on what you're doing. 18-Aug-20 06:33 PM <𝓕ermion#6024> it's mostly just lossy 18-Aug-20 06:33 PM Oh yeah 18-Aug-20 06:33 PM <𝓕ermion#6024> most of tektronix's flagship samplers are on FR4 18-Aug-20 06:33 PM <𝓕ermion#6024> this includes the 40 GHz ones. 18-Aug-20 06:34 PM I have a bunch of slides which characterize FR4 to other materials, etc 18-Aug-20 06:34 PM <𝓕ermion#6024> they were all designed by this guy agoston agoston 18-Aug-20 06:34 PM http://www.ieee802.org/3/10G_study/public/jan00/sayre_1_0100.pdf 18-Aug-20 06:35 PM <𝓕ermion#6024> you might look at FR408 18-Aug-20 06:35 PM <𝓕ermion#6024> quite common 18-Aug-20 06:37 PM Yeah - for now, it's likely a non problem for us because the frequencies we're dealing with are low 18-Aug-20 06:37 PM Like our signals of interest are 900-920 MHz 18-Aug-20 06:37 PM I am sure we can get away with FR4 18-Aug-20 06:37 PM <𝓕ermion#6024> yeah that's easy peasy 18-Aug-20 06:37 PM <𝓕ermion#6024> 4-6 GHz is where things get a little wonky 18-Aug-20 06:38 PM Although my bosses want cheap $5 prototype cost boards 18-Aug-20 06:38 PM That sort of thing 18-Aug-20 06:38 PM It'll be fun 18-Aug-20 06:38 PM What I am supposed to do is to take the RFID module we're using 18-Aug-20 06:38 PM And instead of running pigtail connections to the antennas 18-Aug-20 06:38 PM I am supposed to board mount the modules such that 18-Aug-20 06:38 PM MMCX connectors of the RFID module <--> SMA connectors for the antennas 18-Aug-20 06:38 PM Directly on the PCB itself 18-Aug-20 06:38 PM Since we find the the pigtails tend to be very finicky 18-Aug-20 06:38 PM And cause issues because of movement/vibration 18-Aug-20 06:38 PM It'll be fun to see how the Chinese board houses make these for the cheap prototype board sort of prices 18-Aug-20 06:38 PM Instead of more expensive processes with impedance control, etc 18-Aug-20 06:38 PM And hi @rfs :P 18-Aug-20 06:43 PM <𝓕ermion#6024> I guess jlcpcb does impedance control now. 18-Aug-20 06:43 PM <𝓕ermion#6024> not sure if they do a good job of it though 18-Aug-20 06:44 PM Yeah - but my bosses want boards made for really cheap 18-Aug-20 06:44 PM So basically screw the impedance control processes :P 18-Aug-20 06:45 PM Hmm, reading the backlog, I have seen GaAs-fet first stages in some older 10GBPs linecard receivers. Right after the detector diode. 18-Aug-20 06:45 PM Also, I have friends who have done +2GHz on jlcpcb and seeed pcb's 18-Aug-20 06:45 PM 2.4GHz all day everyday 18-Aug-20 06:45 PM It'll be fun to measure with a VNA and measure the performance and characteristics of transmission lines on PCB processes without impedance control 18-Aug-20 06:46 PM and recently a friend made some up to 4400MHz boards at JLC and they seem to perform ok 18-Aug-20 06:46 PM And the same friend did a 18GHz PLL on 4layer FR4 18-Aug-20 06:46 PM Ah 18-Aug-20 06:46 PM Just the cheap option? 18-Aug-20 06:46 PM at which point you are at dB/mm attenuations 18-Aug-20 06:46 PM Yeah 18-Aug-20 06:46 PM and it was done years ago and it really needed multiple layers 18-Aug-20 06:47 PM Or is this the more expensive controlled processes 18-Aug-20 06:47 PM so it was a 20eur vas 400eur kind of decision on boards 18-Aug-20 06:47 PM Ah 18-Aug-20 06:47 PM So they got away with the 20EUR decision I suppose 18-Aug-20 06:48 PM Impedance control just means that the factory folks might adjust the widths of impedance controlled tracks to make sure you get what you want. As they know their materials and process. 18-Aug-20 06:48 PM That's my understanding anyway. 18-Aug-20 06:48 PM And yeah he went with the cheap option 18-Aug-20 06:48 PM Yeah that's what I am thinking as well 18-Aug-20 06:49 PM there legit is no cheap options for RF pcb's 18-Aug-20 06:49 PM especially when you have multiple layers. 18-Aug-20 06:49 PM Yeah 18-Aug-20 06:49 PM But on the other hand 18-Aug-20 06:49 PM 20years ago 10pcs 10cm x 10cm was 50-600eur 18-Aug-20 06:49 PM My bosses want me to do things for as cheaply as possible - no controlled processes, etc 18-Aug-20 06:49 PM and pcbpool was just starting 18-Aug-20 06:49 PM At 900MHz I'd just design for it, if possible 18-Aug-20 06:49 PM like wide microstrip instead of narrow CPW 18-Aug-20 06:50 PM Yeah 18-Aug-20 06:50 PM so that the process variations matter less 18-Aug-20 06:50 PM and it IS consumer electornics 18-Aug-20 06:51 PM Microstrip is what I am going to do 18-Aug-20 06:51 PM I have seen a wifi router with 5port switch on 2layer FR4 18-Aug-20 06:51 PM and it worked 18-Aug-20 06:51 PM Tho the software was poopoo, there, are you happy now, bot? 18-Aug-20 06:51 PM I guess Dyno is sensitive to these things 18-Aug-20 06:51 PM What I am working on isn't consumer electronics 18-Aug-20 06:51 PM But then again we do have clients that are demanding miracles and perfection 18-Aug-20 06:51 PM Just because they're paying 500 EUR more for our solution 18-Aug-20 06:51 PM Like what do I mean by perfection? 18-Aug-20 06:51 PM Even a 1% RFID error rate - we get complaints 18-Aug-20 06:51 PM It has to be perfection 18-Aug-20 08:39 PM I keep thinking that the current availability of cheap JLC type pcb’s that can do high frequency and complex routes and fine tolerance is a wonderful daydream that will soon come to an end when China decides to punish us all. 18-Aug-20 08:58 PM Bought the Rocker 300C PTFE membrane pump I posted a link to here a couple days back! 18-Aug-20 08:58 PM I shouldn't have, it was kinda a bad impulse! But I did it! 19-Aug-20 06:42 AM <𝓕ermion#6024> I imagine china is doing just fine with jlc 19-Aug-20 06:42 AM <𝓕ermion#6024> it seems more likely that the US will angrily shoot ourselves in the foot 19-Aug-20 12:41 PM I imagine china is doing just fine with jlc @𝓕ermion presumably Charles was taking about the USA suffering should China cut us off 19-Aug-20 01:44 PM Exactly 19-Aug-20 04:11 PM <𝓕ermion#6024> and I think we'll cut ourselves off lol 19-Aug-20 05:30 PM Sounds like the same thing to me 19-Aug-20 06:46 PM Oshpark is more expensive than JLC for sure, but it's not like prices will jump back up to $$$ 19-Aug-20 06:54 PM I like osh for small stuff 19-Aug-20 09:33 PM There's also AISLER.net 19-Aug-20 11:40 PM @transorbs interestingly a guy I'm collaborating with now, in Japan, said he gets smaller boards from OSHpark for cheaper than JLPCB 20-Aug-20 07:50 AM Yeah so it’s not even close, or in the same universe for OSHpark vs JLC in pricing. Our average board is 64 square inches and in 250 piece quantity for a 4 day turn they are $2 each for standard two layer .062 FR4 soldermask and silk on both sides boards with complex routing. I have been told that they are intentionally selling at a loss to basically undercut the rest of the world and they get subsidized by the CCP to do so. 20-Aug-20 07:53 AM who needs boards, plywood + hot glue + solder is all anyone really needs 20-Aug-20 07:53 AM /s 20-Aug-20 08:17 AM literal breadboards amirite? 20-Aug-20 08:17 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/517586d2ce395ff766000002-58700.png 20-Aug-20 08:41 AM That’s how they started out! 20-Aug-20 09:13 AM <𝓕ermion#6024> So happy my vacuum feedthroughs leakcheck 20-Aug-20 09:13 AM <𝓕ermion#6024> The sma bulkheads need a pretty close tolerance and I had to do a little filing 20-Aug-20 11:26 AM @Charles maybe for 250 pieces, but how about just 3 20-Aug-20 11:27 AM Three pieces in the scheme of international commerce is not really an issue. 20-Aug-20 11:27 AM Heck neither is 250! 20-Aug-20 11:39 AM Are you hand assembling 250 boards? 20-Aug-20 12:43 PM @Charles it's a big deal when you're a bootstrapped startup 20-Aug-20 12:43 PM Bigger anyway 20-Aug-20 12:45 PM Yes. We assemble in house by hand for the most part. We have a Neoden4 for some of the surface mount boards but generally most of our products are all through hole for vibrational specs. 20-Aug-20 12:45 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-7FEF4.jpg 20-Aug-20 12:45 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-4BA48.jpg 20-Aug-20 12:45 PM My assembly station is in the middle. I mostly do the prototype and SMT rework. Far ends are the through hole stations and one more on the other side 20-Aug-20 12:45 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-69ED6.jpg 20-Aug-20 12:45 PM All the vacuum stuff is at home in my garage. 20-Aug-20 01:50 PM I guess you work at Alextronix then ;) 20-Aug-20 02:12 PM I hope so, or I have been going to the wrong place for 23 years! 20-Aug-20 04:01 PM Lol 20-Aug-20 04:13 PM working on the HPD amplifier stuff now lol 20-Aug-20 04:13 PM when your output signal is this fast... 20-Aug-20 04:13 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-C6F09.png 20-Aug-20 04:13 PM time for really high GBW op-amps 20-Aug-20 04:13 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-7E39A.png 20-Aug-20 04:13 PM laying out this is going to be fun 21-Aug-20 02:33 AM Been working on a nanopore transimpedance amp and ADC interface 21-Aug-20 02:33 AM Gotta script up my oscope and sig gen to autogenerate Bode plots and calculate baseline noise and ENOB 21-Aug-20 02:33 AM Going for 200nA range with a 16 bit ADC where we need at least 12 bits usable 21-Aug-20 02:33 AM Around 50pA resolution target 21-Aug-20 02:58 AM have fun! ^^ 21-Aug-20 02:58 AM that sounds like there's a fair bit of precision involved 21-Aug-20 03:11 AM It seems like half the exercise is just shopping for the right parts, we've also got a BOM cost target to hit to enable it to be a consumer device, which is proving a little challenging to get good high quality analog at the desired precision and accuracy (but there're sooo many parts out there). 21-Aug-20 03:12 AM Consumer nanopore stuff? 21-Aug-20 11:23 AM Aiming to be that 21-Aug-20 11:23 AM Solid state nano pores 21-Aug-20 04:14 PM finally picked up the turbo today 21-Aug-20 08:23 PM @GigaSquirrel I’m Luke, as per our message yesterday. I often just lurk here and forget to check Discord 21-Aug-20 11:13 PM Ahhh, Hello! :D 22-Aug-20 12:21 AM I see you picked a fitting name 22-Aug-20 11:21 AM well i dont have the main cables so ill have to some cursed stuff lol 22-Aug-20 06:33 PM Why does the cable have to be 300 bux 22-Aug-20 06:33 PM Forces me to find other ways lol 23-Aug-20 08:42 AM Had that kind of issue with my Varian/Agilent TV-301 Navigator too. Luckily the pinout was described in the manual. I had found some contacts that fitted the pins nicely and used some heat shrink. It's not the kind of thing that one wants to connect and unplug often, but works for me ¯\_(ツ)_/¯ Just make double sure that you do not mix the connections. Spinning the turbo in the opposite directions might damage it. 23-Aug-20 11:49 AM Gotta love the mysterious "one of my turbos was off when I got here" experience 24-Aug-20 11:12 AM The cables always cost a lot. Back at a previous employer we had our own made. 24-Aug-20 11:12 AM Even "MILCON", who mostly made cables for rugged enviroments cost a third in small batches than what pheiffer stuff cost :D 24-Aug-20 12:06 PM yeah i mean getting the pin connectors and soldering up some wire is super cheap compared to what they want for the cable 24-Aug-20 12:10 PM only if you have a pin diagram 24-Aug-20 12:10 PM otherwise a dead turbo is not cheaper 24-Aug-20 12:19 PM if any1 has the pinout for the tpu 330 and/or the tcp380 hmu 24-Aug-20 12:19 PM well the tcp380 i think is on the datasheet 24-Aug-20 12:20 PM here let me go check something 24-Aug-20 12:20 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-DE839.jpg 24-Aug-20 12:20 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-10DAC.jpg 24-Aug-20 12:20 PM @charizardrekt is this the cable you need? 24-Aug-20 12:26 PM yeah looks right let me just double check 24-Aug-20 12:26 PM https://www.idealvac.com/Pfeiffer-Turbo-Pump-Cable-TPHU-050/pp/P102884 yup looks like many use the same cable 24-Aug-20 12:27 PM so the connector on the controller side is "A16 DIN 41622" 24-Aug-20 12:27 PM numbered from 1 to 8 starting at the nub side and ending at the hole side 24-Aug-20 12:27 PM if the nub is the bottom, b is on the left and a is on the right 24-Aug-20 12:29 PM ok makes sense 24-Aug-20 12:29 PM the other end is 90 souriau 42 france 851 08EC 14-19 S 50 H2 24-Aug-20 12:30 PM yeah i knew the other side cuz it says on the turbo 24-Aug-20 12:31 PM lettered A-H and J-N and P and R-U 24-Aug-20 12:31 PM Does the one on your turbo have lettering like that? 24-Aug-20 12:31 PM on the turbo side you can pretty easily use individual push-on connectors instead I imagine. 24-Aug-20 12:32 PM yup thats the plan 24-Aug-20 12:32 PM but does it have the lettering like that 24-Aug-20 12:33 PM lemme check 24-Aug-20 12:33 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-9A254.jpg 24-Aug-20 12:33 PM oh on the turbo side? 24-Aug-20 12:33 PM nah 24-Aug-20 12:33 PM Darn 24-Aug-20 12:33 PM its just pins 24-Aug-20 12:35 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/connectorpng-E448E.png 24-Aug-20 12:35 PM you can see the pattern there, right? 24-Aug-20 12:35 PM sorry for crappy pic 24-Aug-20 12:35 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-DE78A.png 24-Aug-20 12:35 PM oh yeah i can see it 24-Aug-20 12:35 PM Ok, well I can map out the pins for you with a multimeter pretty quick 24-Aug-20 12:36 PM wow thanks sm dude thats rlly nice of u 24-Aug-20 12:48 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-6DF89.png 24-Aug-20 12:48 PM the nub and hole below/above the pins on the controller side aren't connected to anything, no two pins seem to be connected together, and I have only measured conductivity so maybe there's a wild shunt resistor or something but someone else would have to weigh in 24-Aug-20 12:48 PM For what it's worth on the TPU 510 I took this from the turbo port does have the lettering. It's just hard to read. Maybe look a little closer in yours? 24-Aug-20 12:54 PM k 1 sec 24-Aug-20 01:04 PM oof looks like im blind u are right 24-Aug-20 01:04 PM sorry 24-Aug-20 01:04 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-7C04E.png 24-Aug-20 01:09 PM that's good for you though 24-Aug-20 01:09 PM makes it harder to muck up putting the connectors on due to mirroring 24-Aug-20 01:09 PM anyways, enjoy. you owe the Canadian government about $3 for my time 24-Aug-20 01:11 PM lol thanks again dude 24-Aug-20 02:16 PM need a way to easily archive convos on discord because I’ll probably have this same question once I buy a 380 for my pump lol 24-Aug-20 02:16 PM screenshots work for now lol 24-Aug-20 02:17 PM @mike crb It would be better to use something designed for that (some wiki, preferably...) 24-Aug-20 02:18 PM yeah but I find there aren’t as many forums that have as good of technical convos as I see here or have on twitter 24-Aug-20 02:18 PM or wikis that is 24-Aug-20 02:22 PM its in #resources 24-Aug-20 02:22 PM what i do is make a server for myself where i save links 24-Aug-20 02:24 PM TBH I think the rules in the #welcome are what make this place so nice. 24-Aug-20 02:24 PM also #off-topic-thats-sometimes-on-topic is a channel every server needs 24-Aug-20 02:31 PM not a bad idea @charizardrekt 24-Aug-20 02:57 PM They certainly make me happy. 24-Aug-20 03:27 PM discord search is actually quite good, fwiw -- i go and look stuff up in here/elsewhere fairly regularly to good effect 25-Aug-20 02:58 PM <𝓕ermion#6024> @idmb @Mezmorizor do you remember what the price of your sumitomo pulse tube and compressor are? 25-Aug-20 02:58 PM <𝓕ermion#6024> I'm trying to find the smallest cheapest 4 K pulse tube. 25-Aug-20 03:01 PM Both of ours precede me, so no idea. Though they're not actually pulse tubes. 25-Aug-20 03:01 PM <𝓕ermion#6024> oh what are they? 25-Aug-20 03:02 PM I think they're just helium compressors honestly. Not positive though. 25-Aug-20 03:02 PM They do get to 4K though 25-Aug-20 03:02 PM Or at least are supposed to 25-Aug-20 03:03 PM <𝓕ermion#6024> hmm 25-Aug-20 03:05 PM Gifford-McMahon refrigeration cycle 25-Aug-20 03:06 PM <𝓕ermion#6024> is it a cryomech? 25-Aug-20 03:08 PM Nah. It's sumitomo. They make 4K pulse tubes and 4K Gifford-McMahon fridges 25-Aug-20 03:08 PM idmb probably knows the exact model we use 25-Aug-20 03:08 PM I don't off the top of my head 25-Aug-20 03:08 PM We also might use the 10K one because we don't really need quite that cold 25-Aug-20 03:08 PM It is the 4K. I want to say it's the RDK-205D, but not positive 25-Aug-20 03:14 PM I believe ARS have the cheapest 4k system 25-Aug-20 03:16 PM @𝓕ermion I am not sure if you are asking about price of new or used. We recently bought brand new Sumitomo RDE-418D4 and it was around $50k (including compressor, flexlines, helium - plug&play) 25-Aug-20 03:17 PM @𝓕ermion It was $30,825 USD including all import stuff to Canada for an F70L with a 408D2 and 30' helium lines. 25-Aug-20 03:18 PM <𝓕ermion#6024> who is ARS? 25-Aug-20 03:19 PM https://www.arscryo.com/ 25-Aug-20 03:19 PM IIRC it was something like $6,000 cheaper than the sumitomo 25-Aug-20 03:19 PM Leybold have the most expensive cold heads IIRC 25-Aug-20 03:20 PM @idmb Do you have any experience with ARS regarding reliability, serviceability, etc? 25-Aug-20 03:21 PM <𝓕ermion#6024> well... we have this dumbass DR that has an external 4k cold trap and no room for a port. 25-Aug-20 03:21 PM <𝓕ermion#6024> so it's just burning helium. 25-Aug-20 03:21 PM <𝓕ermion#6024> so I reckon for 20-30k if we can scare something together to cool a trap, that'd be nice. 25-Aug-20 03:22 PM No experience, but our collaborators have one which is a few decades old. TBH I don't think any group I know has had any issues with any of their cold heads. 25-Aug-20 03:23 PM <𝓕ermion#6024> we have a 70k helium reliquefier for the cryostat's bath 25-Aug-20 03:23 PM <𝓕ermion#6024> and the trap is just burning helium 25-Aug-20 03:23 PM <𝓕ermion#6024> I guess the solution then is to reliquefy into a multineck dewar with the trap in it 25-Aug-20 03:23 PM <𝓕ermion#6024> and then transfer from that dewar into the cryostat or something 25-Aug-20 03:25 PM In our world the RDK-408D2 is the cold head 25-Aug-20 03:25 PM seemingly just because of availability back then 25-Aug-20 03:34 PM More or less yeah. We don't use pulse tubes because pulse tubes weren't really available when the instruments we all copied were first designed. 26-Aug-20 03:09 AM Well it seems I just 'fixed' a IKR 251 gauge. The meter had suddenly read overrange while attached to a SEM that was imaging fine, so the reading must have been wrong. I first suspected the gauge's electronics, but the meter showed underrange when the gauge was disassembled and the inverted magnetron disconnected from the gauge's electronics. An ohmmeter showed 300 kOhm between anode and cathode. That 'short' disappeared after I removed the magnet. 26-Aug-20 03:09 AM After reassembly it measured again. Not sure if I should trust it though. The only check that I can think of is testing it against a pirani gauge, as I don't have another high vacuum gauge nor a bottle of precision vacuum lying around 27-Aug-20 10:20 AM @Mezmorizor Random question - have you ever tried cooling down with a lower backing pressure, and then raising it? I wonder how much the conductivity of the vacuum affects the cooldown time... Can I save 5 minutes ? 27-Aug-20 10:24 AM That's what we usually do 27-Aug-20 10:24 AM No idea if it's faster 27-Aug-20 10:24 AM The idea was more "no reason to waste helium" 27-Aug-20 10:28 AM meanwhile henrik, they run 10 bar through the nozzle when idle lol 27-Aug-20 10:28 AM thou shalt not clog. 27-Aug-20 10:35 AM Oh, that's what I meant 27-Aug-20 10:35 AM We never go below 10ish bar 27-Aug-20 10:35 AM Yeah no flow is a great way to get a clog 27-Aug-20 10:38 AM Freiburg goes to 2 bar when warm 27-Aug-20 10:38 AM but also they can get a new nozzle with like a days notice 27-Aug-20 10:38 AM jealous of their shop. 27-Aug-20 10:07 PM wow i really like the pics on the ARS site. i'm all about that vacuum probe station aesthetic 28-Aug-20 06:16 PM <𝓕ermion#6024> Am I the only low temperature person here? 28-Aug-20 06:16 PM <𝓕ermion#6024> I need to design a top loader probe 28-Aug-20 06:50 PM Low meaning?... 28-Aug-20 07:03 PM <𝓕ermion#6024> 20 mK 28-Aug-20 07:05 PM Well below me but well above the neighbours :’) 28-Aug-20 07:08 PM <𝓕ermion#6024> heh 31-Aug-20 11:50 AM https://youtu.be/0jeFpXHZ8W0 I love the animations lol 31-Aug-20 11:50 AM It must be not too bad to make a simple linear ToF with a homemade electron gun for ionization? 31-Aug-20 11:53 AM do iiiit 31-Aug-20 11:54 AM I made a not-simple one with a not-homemade laser 31-Aug-20 11:54 AM homemade laser part would be kinda annoying but doable 31-Aug-20 11:54 AM e-gun should be easier 31-Aug-20 11:55 AM how strong does the laser have to be 31-Aug-20 11:55 AM the music is so intense 31-Aug-20 11:55 AM lol 31-Aug-20 11:56 AM Not super strong 31-Aug-20 11:56 AM Ok by normal standards super strong I guess. I think the YAGs random people buy can do it 31-Aug-20 11:59 AM yeah random people... 31-Aug-20 12:00 PM = not someone with funding 31-Aug-20 12:15 PM lol 31-Aug-20 12:15 PM im wondering if a laser is used instead for short pulse width or something 31-Aug-20 12:18 PM Should I be worried that I'm getting double the manufacturer's QA power output on my pump laser? 31-Aug-20 12:18 PM Up to ~1.5 J/pulse assuming the beam sampler is Fresnel reflection based like Thorlabs says and that my power meter is roughly correct 31-Aug-20 12:21 PM rep rate matching? 31-Aug-20 12:21 PM YAG J/pulse varies a lot with rep rate 31-Aug-20 12:21 PM they don't maintain average power or pulse energy 31-Aug-20 12:21 PM it's a wild curve 31-Aug-20 12:45 PM It's the rep rate the QA did 31-Aug-20 12:45 PM Though I think the meter is just wrong 31-Aug-20 12:45 PM Its a tiny YAG 31-Aug-20 12:45 PM I have trouble believing its doing 1.5 J/pulse 31-Aug-20 12:45 PM Especially when I don't have the flash lamp voltage really high 31-Aug-20 12:46 PM clearly you need to do a science experiment 31-Aug-20 12:46 PM to measure your power 31-Aug-20 12:48 PM @charizardrekt usually I've seen MALDI used with complex or biological samples, so maybe they're wet or otherwise offgassing enough that an e-beam would not penetrate to the surface/bulk as much as a laser would 31-Aug-20 12:49 PM tru that would make sense 31-Aug-20 12:50 PM I'm pretty sure its just because the laser will fragment less than an electron beam 31-Aug-20 12:53 PM @Mezmorizor hmm wouldn't that be controllable with the accelerating voltage tho? 31-Aug-20 12:53 PM And/or beam current 31-Aug-20 12:59 PM e-gun is much more energetic 31-Aug-20 01:00 PM I should have finished my thought. Yes, you can use an e beam and change the energy to reduce fragmentation, but it wouldn't really be MALDI at that point. The point of MALDI is that you're not actually blasting your sample with the ionizer. Rather, you're abating a matrix you suspended your analyte in and then the matrix ionizes your analyte which imparts less energy than direct ionization would. I'm also not sure if you can really feasibly make an e gun that isn't significantly more energetic than a laser 31-Aug-20 01:00 PM So you can use an e gun to ionize for a TOF, but it wouldn't really be soft ionization like MALDI 31-Aug-20 01:01 PM looks like maldi uses frequency tripled or quadrupled nd:yag 31-Aug-20 01:01 PM or nitrogen lasers 31-Aug-20 01:01 PM yikes 31-Aug-20 01:07 PM It does yeah. Ablation is much, much, much, much more efficient at high energies 31-Aug-20 01:07 PM To the point where doing the nonlinear conversions make it easier 31-Aug-20 01:08 PM hmm so making a diy laser seems a bit harder for it 31-Aug-20 01:08 PM but still achievable probably 31-Aug-20 01:09 PM You could also just use a big ass YAG tbh 31-Aug-20 01:09 PM It works, people will just look at you funny because it's kind of like using a sledgehammer to hammer in a normal nail 31-Aug-20 01:10 PM eh that seems pretty epic 31-Aug-20 01:10 PM oh yeah idk if i already said here but got a great deal on caps 31-Aug-20 01:11 PM YAGs come in every size 01-Sep-20 07:40 PM Somehow I’ve wound up choosing between neutron activation analysis and laser induced breakdown spectroscopy for a thesis. And now I’m stuck 01-Sep-20 07:40 PM Neutrons for the win 01-Sep-20 07:44 PM lasers for the win 01-Sep-20 07:53 PM Always laser 01-Sep-20 07:53 PM Coulomb explosion best explosion 01-Sep-20 07:58 PM laser 01-Sep-20 07:59 PM NEUTRONS NEUTRONS NEUTRONS 01-Sep-20 09:05 PM neutrons are so 1940s 01-Sep-20 09:05 PM lasers are from the much cooler 1960s 01-Sep-20 09:08 PM Just think of how many rubies you can burn with a ruby burner! 01-Sep-20 10:02 PM Ill probably wind up doing NAA if I can manage it, there’ll be more chances for lasers in the future 01-Sep-20 10:13 PM With that outlook, you should transfer to some subset of climate science before it's too late 01-Sep-20 10:15 PM I mean there are more people doing laser related stuff then have research reactors, bigger thing is just ive been realizing in the last bit that I want cap off things at this school doing something nuclear related 01-Sep-20 10:17 PM all i have to say is: lasers 01-Sep-20 10:17 PM what about laser based fusion? 01-Sep-20 10:18 PM you don't quite get to choose things like that 01-Sep-20 10:18 PM it's more of a "pick from what's available and maybe add a little to the idea" 01-Sep-20 10:18 PM In this case it’s a choose your analytical method for one of these two or three things 01-Sep-20 10:20 PM @charizardrekt community run NIF? lol 01-Sep-20 10:20 PM tru tru 01-Sep-20 10:20 PM i wasnt thinking really practically 01-Sep-20 10:21 PM I am not even sure NIF has done any pulses yet 01-Sep-20 10:23 PM daaang 01-Sep-20 10:23 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-4E15E.png 01-Sep-20 10:24 PM yeah 01-Sep-20 10:24 PM it's going to be a heck of a laser to build 01-Sep-20 10:24 PM not sure a university is going to fund that 01-Sep-20 10:30 PM they have done some shots tho 01-Sep-20 10:30 PM i think 01-Sep-20 10:30 PM https://lasers.llnl.gov/science/ignition/ignition-experiments 01-Sep-20 10:31 PM ah 01-Sep-20 10:31 PM I remember they ran into some delays and issues 01-Sep-20 10:31 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-BA6A0.png 01-Sep-20 10:33 PM i wonder if they tried aneutronic fuel 01-Sep-20 10:33 PM proton-boron fusion stuff 01-Sep-20 10:51 PM NIF results are quite impressive on paper, but I think all of them know it's not going to be a practical way to make a break-even reactor, even if theoretical breakeven has been reached. p-B11 has not been done at NIF yet, last time I read their updates, they just got their tritium systems working and is slowing ramping up tests with DT yields, in-between the stockpile stewardship weapon physics tests 01-Sep-20 10:51 PM @Addison-110m What will you be performing neutron activation analysis on? The project I'm on at work is doing essentially NAA on fuel rods to determine enrichment, boron content... etc. Would be interesting to see novel applications 01-Sep-20 10:51 PM For smaller and more compact neutron sources 01-Sep-20 10:56 PM im sure lasers can somehow be implemented into the neutron thing 01-Sep-20 10:58 PM lasers for everything 01-Sep-20 10:59 PM I'm looking at a paper that uses pulsed YAG laser to vaporize some boron fuel to achieve p-B11 reactions in a pretty big plasma focus 01-Sep-20 10:59 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-41C46.png 01-Sep-20 10:59 PM This doesn't look that far from what can be done at home 01-Sep-20 10:59 PM 0.7 J per shot is a bit too much for my q-switched Nd:YAG though... Need a bigger rod for that 01-Sep-20 10:59 PM Fairly interesting way to attach the lens with a KF clamp there, pretty sure that's not a standard commercial part 01-Sep-20 11:03 PM I've seen that 01-Sep-20 11:03 PM also using 1" optical posts as plugs for those "quick connect" vacuum couplings 01-Sep-20 11:03 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Photo-HD-FC_FO275XVC075_std-570FF.png 01-Sep-20 11:03 PM lots of "hey, if it works..." 01-Sep-20 11:06 PM Ah, I've got a few of those. But I think I'll DIY first. I think the author is implying they did make that lens holder themselves. I'm going to ask one of them since it'll be a heck of a lot cheaper to do this when I don't need to go to high vacuum 01-Sep-20 11:07 PM what's to ask? two appropriate lathe-cut pieces of delrin will work fine 01-Sep-20 11:07 PM I want to know what lens they used, and more questions about the vacuum feedthrough on the bottom of that electrode 01-Sep-20 11:07 PM Mine didn't work very well 01-Sep-20 11:09 PM your DIY feedthroughs? 01-Sep-20 11:09 PM Yeah, with o-ring seals and a quartz insulator in there 01-Sep-20 11:09 PM what kind of leak rate? 01-Sep-20 11:11 PM Problem is not leak rate, it is consistency. It consistently shatters/chips my quartz insulator while not consistently making a good seal 01-Sep-20 11:11 PM oh yikes 01-Sep-20 11:11 PM vacuum epoxy into a ceramic tube that fits in one of those quick-connects would presumably work fine 01-Sep-20 11:12 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-8DF73.png 01-Sep-20 11:12 PM Oh it is way bigger than that 01-Sep-20 11:13 PM how many amps are you plannning? 01-Sep-20 11:13 PM >200 kA peak, low inductance is key here 01-Sep-20 11:13 PM But the quartz tube size is constrained by factors other than peak current, so I can't change the size of the feedthrough 01-Sep-20 11:13 PM I think the problem is the pressure applied by fragile ceramic bolts 01-Sep-20 11:13 PM I can torque them all to the same torque spec, but they may not consistently achieve the same pressure on that fairly beefy viton o-ring 01-Sep-20 11:13 PM Anyway I broke too many of those bolts and now all 3 quartz tubes I have on hand have defects on them 01-Sep-20 11:13 PM Another reason why you should pick from what's available and join one that sounds fun, and not pay for everything out of pocket 01-Sep-20 11:18 PM so consider this 01-Sep-20 11:18 PM have you looked into what ones specced for lower 01-Sep-20 11:18 PM actually do if you overdrive them? 01-Sep-20 11:18 PM Maybe a commercial 1000A one is actually fine for your needs? 01-Sep-20 11:20 PM I should emphasize that the quartz tube here is actually part of the plasma focus device, it's material, shape and surface finish...etc. are constrained by factors other than the maximum voltage it can hold off and the maximum current the feedthrough can handle 01-Sep-20 11:20 PM yech 01-Sep-20 11:21 PM So unfortunately no existing commercial feedthroughs would give me what I want, because I'm designing essentially a controlled breakdown here starting from the feedthrough 01-Sep-20 11:21 PM I should get a lathe too 01-Sep-20 11:22 PM oh yeah those laser proton-boron fusion things are cool 01-Sep-20 11:22 PM i have a list of papers about it somewhere 01-Sep-20 11:22 PM may end up going nowhere but its interesting 01-Sep-20 11:24 PM It's proven to go nowhere in steady-state plasmas, too much bremsstrahlung loss leading to low temperature. Only way to make it work is inertial confinement, or a mix of inertial and magnetic, condition is just very high compression ratio and short confinement time 01-Sep-20 11:24 PM i have a list of papers about it somewhere may end up going nowhere but its interesting 02-Sep-20 06:50 AM NIF was always about studying nuclear weapon conditions, not making a practical fusion reactor. 02-Sep-20 06:50 AM And the easiest way to do a lens holder that's doing that is, assuming a lens with the appropriate focal length exists, is taking a KF centering ring, shaving down one side so it's flush with the o ring, and attaching it to the system with a bulkhead clamp 02-Sep-20 06:50 AM https://www.lesker.com/newweb/flanges/hardware_kf_clamps_bulkhead.cfm?pgid=al 02-Sep-20 06:50 AM https://www.lesker.com/newweb/flanges/hardware_kf_centeringrings.cfm?pgid=ss 02-Sep-20 08:40 AM @idmb I mean like a list of papers others wrote lmao I don't do anything related to that. 02-Sep-20 08:40 AM IDK if I made that clear 02-Sep-20 09:02 AM I’m joking about how we do the same 02-Sep-20 09:02 AM Oh lol 02-Sep-20 10:48 AM The fact people even think NIF could be used for reactor research is thanks to some rather disingenuous Congressional testimony by its former director. He'd tell you NIF makes sliced bread if that would get the appropriations he wanted. 02-Sep-20 10:49 AM that actually makes sense now 02-Sep-20 10:49 AM NIF always confused me a bit 02-Sep-20 10:52 AM @funranium prove that nobody has ever sliced bread in a NIF facility 02-Sep-20 11:20 AM You clearly need gigajoule pulses to slice bread. The megajoules it does now aren't enough 02-Sep-20 11:47 AM hmmmm can you build a laser with enough energies to start another universe that can bear life like humans 02-Sep-20 11:47 AM and then when they bake bread 02-Sep-20 11:47 AM steal it from them 02-Sep-20 11:47 AM although if we can do that... what would the implications be? 02-Sep-20 11:47 AM could we be in a universe created by other sentient beings and are just being observed by them? 02-Sep-20 02:16 PM Huh, why does the varian v81m have such a terrible compression ratio for helium? 02-Sep-20 02:31 PM Anyone w/ a Cesium frequency standard? are there any appreciable alternatives at roughly that second hand price point? 02-Sep-20 02:31 PM it would be used to calibrate ovenized oscillators 02-Sep-20 02:31 PM which in turn would be used to calibrate.. iunno... watches.. running at 5hz max 02-Sep-20 02:31 PM I know GPS receiveers and whatnot exist, but I also know (from eevblog) that they can be a bit off 02-Sep-20 02:31 PM at the low pricepoint 02-Sep-20 02:31 PM I assume better stuff is $$ 02-Sep-20 07:41 PM The GPS references at used Cesium frequency standard pricepoint are decent 02-Sep-20 07:41 PM I really should test my dumpster find rubidium 02-Sep-20 08:13 PM <𝓕ermion#6024> I can't get my SMA feedthroughs leak tight 02-Sep-20 08:13 PM <𝓕ermion#6024> it's really frustrating 02-Sep-20 08:13 PM <𝓕ermion#6024> I faced the sealing surfaces, sanded up to 2000 grit and then polished with pickl polish just to go totally nuts 02-Sep-20 08:13 PM <𝓕ermion#6024> so i know it's not the surface finish 02-Sep-20 08:13 PM <𝓕ermion#6024> but the SMA connectors use these tiny viton o-rings which look to be in kinda poor shape under the microscope. I bet it's those. 02-Sep-20 08:13 PM <𝓕ermion#6024> number 010 o-rings 02-Sep-20 08:13 PM <𝓕ermion#6024> am I correct in thinking that a tiny o-ring will have a harder time sealing when there's schmutz around? 02-Sep-20 08:13 PM <𝓕ermion#6024> seems like a big o-ring will be compressed over the schmutz. 02-Sep-20 08:13 PM <𝓕ermion#6024> so assuming the schmutz stays the same size and different sized o-rings, bigger o-rings would seem to seal easier 02-Sep-20 08:37 PM how leak tight? 02-Sep-20 08:37 PM they don't look hard to seal... 02-Sep-20 08:37 PM is this for real RF or some weird high voltage or fiber coupling? 02-Sep-20 09:18 PM <𝓕ermion#6024> 2 MHz max nothing too fancy 02-Sep-20 11:44 PM So, as is with my current pump, I can get down to a vacuum pressure of ~650 Torr below Atmosphere, so I guess 110 Torr. If I wanted to get into Medium Vacuum range, would there be a way to chain pumps/stages to make this possible? I don't think I've ever set up anything more impressive than low vacuum before, so I'm fully out of my comfort zone 02-Sep-20 11:55 PM Like would it be possible to just chain 2 diaphragm pumps + add some kind of bladder in between to get down to lower pressures? That feels like it would be too easy and would produce diminishing returns? But I really have no idea and would appreciate some input 03-Sep-20 12:05 AM Sounds like you have a leak 03-Sep-20 12:05 AM But definitely chaining certain types of pumps work... More common to use a turbo as the second in line, but you want at least an order or two lower pressure than you're getting 03-Sep-20 02:46 AM It depends what limits you - if it is pumping speed, compression ratio or ultimate pressure. If it is pumping speed, you can get two same pumps in parallel. If it is compression ratio/ultimate pressure, you can chain two pumps in series. If you are getting 1e4 Pa, you probably run out of pumping speed (because of leak or outgassing) and getting "twice what you have" would just help you getting to 5e3 Pa... 03-Sep-20 08:07 AM If you’re only getting to 100 torr you have other issues 03-Sep-20 08:07 AM Chaining pumps or putting them in parallel works, but it’s always your weakest point limiting you 03-Sep-20 08:35 AM <𝓕ermion#6024> what's the best way to get dust off really tiny parts besides sonication? 03-Sep-20 09:29 AM plasma? 03-Sep-20 09:29 AM clean gas jet? 03-Sep-20 09:29 AM electrostatic repulsion? 03-Sep-20 09:44 AM y'all 03-Sep-20 09:44 AM ever tried electron induced etching? 03-Sep-20 09:44 AM FEBIE 03-Sep-20 11:57 AM When putting turbopumps in series... Is there any reason to care which one you turn on first? 03-Sep-20 12:10 PM I mean, this pump is only rated for 145 mbarr 03-Sep-20 12:10 PM So, 110 mmhg 03-Sep-20 12:10 PM So I don't think the issue is a leak 03-Sep-20 12:12 PM Oh, sounds like the wrong kind of pump then for this chatroom 03-Sep-20 12:12 PM Maybe meant for like, automotive use? (Sucking out oil from an engine, etc)? 03-Sep-20 12:12 PM Vacuum filtration 03-Sep-20 12:12 PM Which can usually be done with really low vacuum pressure 03-Sep-20 12:13 PM Recently I was thinking of vacuum filtration and thinking how for a lot of precision/food applications it seems you'd want to avoid oil backstreaming 03-Sep-20 12:13 PM Yup, this is a ptfe diaphragm pump. 03-Sep-20 12:14 PM For some botanical extract stuff, I've seen they sell scroll pumps with vacuum over dessicators 03-Sep-20 12:14 PM No oil, no outgassing. 03-Sep-20 12:14 PM Ah, nice 03-Sep-20 12:14 PM sounds like the wrong kind of pump then for this chatroom elitist eh 03-Sep-20 12:15 PM Hey this isn't "lowVacuumHackers" 03-Sep-20 12:15 PM I'm wondering if I can repurpose it with another similar pump in series to get down to on the order of 10 mmhg 03-Sep-20 12:15 PM @hedgeberg 145mbarr is several orders of magnitude off from what you have? 03-Sep-20 12:15 PM Huh? 03-Sep-20 12:15 PM Nah, they're getting about that 03-Sep-20 12:15 PM Oh 03-Sep-20 12:15 PM nvm 03-Sep-20 12:15 PM misread as mtorr 03-Sep-20 12:15 PM ok but 03-Sep-20 12:15 PM to turn this pump 03-Sep-20 12:15 PM into a sub-torr pump 03-Sep-20 12:15 PM now that would be vacuum hacking 03-Sep-20 12:16 PM Haha 03-Sep-20 12:16 PM You'd also need a sub-torr pump 03-Sep-20 12:16 PM Maybe a weak-motored one? 03-Sep-20 12:16 PM Like otherwise i can't see the reason for chaining them 03-Sep-20 12:16 PM I mean, that's basically why turbos need chained, because the blades would overheat 03-Sep-20 12:16 PM They're too "weak" 03-Sep-20 12:16 PM (materially) 03-Sep-20 12:16 PM But yeah if you had a better pump with a half dead motor, then chaining seems reasonable as a patch/workaround 03-Sep-20 12:19 PM Well, diaphragm pumps are differential in terms of pressure, no? If the environment pressure is lower, there would be a lower effective atmospheric pressure to work against 03-Sep-20 12:20 PM Hmm, I can't say for sure, but I thought dead volume had something to do with it 03-Sep-20 12:20 PM That's my first-order thought, at least, but like I said, I'm sure it's not that simple 03-Sep-20 12:20 PM Mmm, fair. 03-Sep-20 12:21 PM Easiest way is to just test 03-Sep-20 12:21 PM Throw a household vacuum cleaner on it's exhaust 03-Sep-20 12:21 PM Check with your gauge 03-Sep-20 12:23 PM my turbos in series are having fun 03-Sep-20 12:23 PM The second one is currently not doing much useful. Yet. 03-Sep-20 12:27 PM So, looking at it, it looks like most diaphragm pumps that get down to <50 mmhg use 2 stages like I'm proposing. It seems like it's major diminishing returns, but it might work. 03-Sep-20 12:27 PM all of vacuum is diminishing returns 03-Sep-20 12:27 PM your first order of magnitude is the best 03-Sep-20 12:39 PM Yeah looks like my theory is valid here, I guess? just need a way to test, which would require another vacuum pump. Anyone have any clever thoughts on how to rig up a vacuum cleaner to mate with a vacuum pump? 03-Sep-20 12:41 PM Lot of duct tape? 03-Sep-20 12:41 PM I mean I guess that works, sure. 03-Sep-20 02:04 PM Ok why are my series turbos not getting lower 03-Sep-20 02:24 PM wuh, turbos in series? why? 03-Sep-20 02:24 PM are they identical? 03-Sep-20 02:47 PM compression ratio of one is only 10^4 for helium 03-Sep-20 02:47 PM leybold 1000C backed by Leybold 2200iPL 03-Sep-20 02:47 PM the 2200iPL is pumping its own chamber too, but the gas load on the one with the 1000C is tiny. But with 1E-2 in the forevacuum I only get 1E-6 in the chamber... And I want lower 03-Sep-20 02:56 PM almost sounds like a leak or outgassing 03-Sep-20 02:56 PM oh, helium 03-Sep-20 02:58 PM Yeah. Pressure is fine if I isolate it from helium haha 03-Sep-20 02:58 PM aha, I think it was my leak valve being a brat 04-Sep-20 03:03 AM always helium 04-Sep-20 03:03 AM no FEBIE people? :(( 04-Sep-20 04:02 AM Not yet, I only do FIB etching so far 04-Sep-20 04:02 AM The only e-Beam etching I've even read about was TEM drilling for nanopores 04-Sep-20 04:02 AM Presumably though it's just the same as e-beam deposition but with a etching chemistry instead of deposition 04-Sep-20 04:54 AM yep 04-Sep-20 04:54 AM you can use a SEM 04-Sep-20 04:54 AM carbon processing seems to be pretty harmless 04-Sep-20 04:54 AM using water vapor as etching agent 04-Sep-20 04:54 AM but for Si stuff like XeF2 of course 04-Sep-20 04:54 AM but I also read that you could use chlorine for Si and Ge 04-Sep-20 04:54 AM but probably it's not that easy because everything has to be super UHV clean 04-Sep-20 04:54 AM because every tiny trace contamination with hydrocarbons induce inhibiting concurrent reactions or something like that 04-Sep-20 04:54 AM but maybe the solution for that is a higher pressure of chlorine 04-Sep-20 04:54 AM but with lower resolution 04-Sep-20 06:52 AM ok so the leak valve was holding it back 04-Sep-20 06:52 AM but I'm still only getting 5.7E-7 torr 04-Sep-20 06:52 AM when the chain is 04-Sep-20 06:52 AM iGX600L -> Leybold 2200iPL -> Leybold 1000C 04-Sep-20 06:52 AM Forevacuum is 1E-2 torr, middle chamber is 1E-5 torr, third chmaber is only 5.7E-7 torr 04-Sep-20 12:15 PM @N00N eh purity depends on your goals... If it's just for mechanical purpose, like @Noxz gears and such... Or shaping hardness probes, lithography/security marking... Probably a little impurity isn't a harm 04-Sep-20 12:22 PM purity is an issue w/ watch oils 04-Sep-20 12:22 PM and I had a few alloys tested/ID'd on production watches, I actually want 3 moree tested, the mainspring, hairspring, and balance wheel 04-Sep-20 12:22 PM then finding some company to make me a standard wire of the spring that I can then form into the correct dimension 05-Sep-20 01:37 AM ah ok thought it renders the wanted reaction to app zero 05-Sep-20 01:37 AM @Noxz @nmz787 what etchands did you use? 05-Sep-20 01:37 AM Cl2 gas via needle over the surface you processed? 05-Sep-20 02:08 AM Etching only used native ions from ion beam, or water vapor, or phenanthrene for doing carbon deposition 05-Sep-20 02:47 AM ah ok ok 05-Sep-20 02:47 AM FIB 05-Sep-20 02:47 AM Ga Ions? 05-Sep-20 04:31 AM I only have FEB - STEM - in the lab 05-Sep-20 04:31 AM but - as far as I understand it - I don't want Ga doping 05-Sep-20 04:41 AM (I want to alter the surface structure of SPADs) 05-Sep-20 12:15 PM Yeah I've only used gallium FIB 05-Sep-20 12:15 PM There are newer styles that use noble gasses instead, for less contamination/doping 06-Sep-20 09:30 AM yeah helium and stuff but $$$ 06-Sep-20 09:30 AM right? 06-Sep-20 09:30 AM or heavier noble gas? 06-Sep-20 12:14 PM Ga vs Ne vs He 06-Sep-20 12:14 PM https://cdn.discordapp.com/attachments/597334400618725385/696614394049724467/Screenshot_20200405-235629.png 06-Sep-20 01:09 PM Can anyone hazard a guess at what flange this is? Wondering if its something like a KF 100LF but unsure 06-Sep-20 01:09 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/ZYmcxUlCdRegQt0xgT6KP7ylDqmcwjTR3ChX7EfTzY-7C0BD.png 06-Sep-20 01:28 PM @meowter_space do you have an ISO 100 ring? 06-Sep-20 04:38 PM Joined the server. 07-Sep-20 02:38 AM Joined the server. 07-Sep-20 02:41 AM Welcome! 07-Sep-20 02:44 AM thanks 08-Sep-20 02:01 PM hey people who understand RGAs 08-Sep-20 02:01 PM the CEM 08-Sep-20 02:01 PM when I do something which should be changing the amount of signal I get 08-Sep-20 02:01 PM with CEM on it goes down and with CEM off it goes up 08-Sep-20 02:28 PM Hmm, that sort of jives with this graph and it's explanation, sort of https://www.researchgate.net/figure/Positron-CEM-Rate-solid-line-and-left-axis-over-laid-on-the-RGA-partial-pressure-of_fig7_320135442 08-Sep-20 04:47 PM seems weird 08-Sep-20 04:47 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/3vs5-8BD12.png 08-Sep-20 08:22 PM Can't find any under ~$100 on ebay, but looking for kf40 or kf25 viewports for fairly cheap 08-Sep-20 08:22 PM if anyone has any leads would very much appreciate it! 08-Sep-20 08:41 PM just epoxy glass onto a weld nipple 08-Sep-20 08:48 PM any epoxy you suggest 08-Sep-20 08:48 PM What's going on in the chamber / what pump is it / how catastrophic is a leak? 08-Sep-20 08:48 PM also how thick of glass would I need at minimum to prevent it imploding 08-Sep-20 08:48 PM 1e-2 torr pressure range is what I'm looking for 08-Sep-20 08:48 PM just a roughing pump to get it down there 08-Sep-20 08:48 PM rv8 08-Sep-20 08:51 PM I can ask those that have done it whether they used special epoxy, like Torr-Seal, but I think it's likely they just used regular 5 minute epoxy 08-Sep-20 08:51 PM as long as you have the glass "on top" of the nipple, and there's a layer of something malleable (the epoxy), the vacuum will help hold it there. 08-Sep-20 08:51 PM If you have a lathe you can also cut something pretty simple that would work better 08-Sep-20 08:51 PM @mike crb see: https://discord.com/channels/513115950501855256/514721733626822666/751198319593914810 08-Sep-20 08:51 PM You can also use acrylic instead of glass, if it's not for a laser 08-Sep-20 09:01 PM would that be too much outgassing on top of the epoxy 08-Sep-20 09:01 PM i assume it wouldn't be i'm just worried I won't be able to easily get to target pressure since I'll probably have 2 viewports w/ epoxy 08-Sep-20 09:04 PM What does the pump get to if you gauge it directly? spec is 1.5E-3 torr to 4.6E-2 torr depending on the oil? 08-Sep-20 09:16 PM well christ just had something not great happen 08-Sep-20 09:16 PM turned roughing pump on for first time in a while 08-Sep-20 09:16 PM all vacuum parts hooked up properly... and it let the smoke out and the chord is extremely hot???? 08-Sep-20 09:21 PM Motor winding ruined? 08-Sep-20 09:22 PM nope I guess its fine??? 08-Sep-20 09:22 PM a lot of confusion and a mini-heart attack there 08-Sep-20 09:23 PM I thought something broke today 08-Sep-20 09:23 PM but turns out the forest fires are just bad again and everything in vancouver smells like smoke 08-Sep-20 09:34 PM hmm its pulling not the best rn but this pump oil has been sitting a while and I didnt clean some of the parts before I assembled them 08-Sep-20 09:43 PM looks bit under 100 mtorr though 08-Sep-20 09:44 PM We have two Edwards 40 pumps that have been sitting for ~5 years now. I’m fairly confident if I just plugged them in, they’d hit 0.05 torr quickly and 0.005 after not too long... 08-Sep-20 09:44 PM Cleaning really shouldn’t be an issue with even the pumping speed you’ve already got 08-Sep-20 09:45 PM hmm dunno whats up with it, ill retry later... I was at 50 mtorr before I moved with a belljar/gasket + some ptfe sealed threads so idk 08-Sep-20 09:53 PM high-vac mode and closed gas ballast... everything tightened up.. nothing I can think of that'd out of the ordinary, sounds like it normally does 10-Sep-20 12:16 PM Oh, huh, bot censors acronyms. Fair enough 10-Sep-20 12:16 PM Was trying to say that the ultrasonic soldering technique in Ben Krasnow's newest video is so cool, and Im miffed that I didn't know about it 4 years ago when I really needed this 10-Sep-20 12:16 PM Would have totally changed the project I was working on. 11-Sep-20 10:09 AM I think there was some discussion about ultrasonic soldering in the past if you use the discord search 11-Sep-20 01:32 PM @idmb is supersonic expansion cooling any different than normal gas law stuff? 11-Sep-20 01:35 PM In what sense? 11-Sep-20 01:35 PM It's all assuming ideal gas, if that's what you mean 11-Sep-20 01:35 PM It's just showing you you get a high density of nearly-1k gas 11-Sep-20 05:29 PM Ah 11-Sep-20 11:10 PM we should use supersonic and ultrasonic exchangeable from now on 13-Sep-20 09:04 AM <𝓕ermion#6024> I want a supersonic toothbrush 13-Sep-20 01:13 PM So it looks like it might wind up being both lasers and neutrons for my thesis for working on elemental analysis. 13-Sep-20 01:42 PM Joined the server. 13-Sep-20 02:04 PM Heya @adammunich ! I loved your article on the big-arse neutron detector suit case 13-Sep-20 02:16 PM oh yeah i still have that thing 13-Sep-20 02:16 PM I have no idea what to use it for still, maybe some neutron telescope observatory or something 13-Sep-20 02:19 PM suitcase neutron detector? 13-Sep-20 02:19 PM https://adammunich.com/nuclear-bomb-detector/ 13-Sep-20 02:24 PM Nice video with the laser microscope 13-Sep-20 02:26 PM oh damn that's cool 13-Sep-20 03:53 PM Joined the server. 13-Sep-20 07:33 PM Joined the server. 13-Sep-20 07:38 PM #introductions_and_directory 13-Sep-20 07:38 PM pls 13-Sep-20 10:51 PM Joined the server. 13-Sep-20 10:51 PM also welcome, new people! 14-Sep-20 05:10 AM I received a very... shocking package indeed 14-Sep-20 05:10 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200914_200359-4D4A6.png 14-Sep-20 05:10 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200914_200657-30B37.png 14-Sep-20 05:10 AM I'll go ohm now 14-Sep-20 05:10 AM but yes - high voltage measurements time ^^ 14-Sep-20 06:32 AM expensive? 14-Sep-20 06:51 AM Iirc 14-Sep-20 06:51 AM This cost $170+ USD 14-Sep-20 09:33 AM So sick of this smoke in the air 14-Sep-20 09:34 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-E6D29.jpg 14-Sep-20 09:34 AM Same. Same. 14-Sep-20 09:34 AM Lab is nice and HEPA though 14-Sep-20 09:34 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-EE8B3.jpg 14-Sep-20 09:35 AM I ordered some PM2.5 sensors for my home lab 14-Sep-20 09:35 AM @adammunich here is my acrylic viewport. ISO-250F 14-Sep-20 09:35 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-3CBC3.jpg 14-Sep-20 09:35 AM Have a thin layer of some other plastic that came with my turbo on top 14-Sep-20 09:35 AM Because it scratches much less easily than the acrylic, and I use it as a table 14-Sep-20 10:09 AM Familiar looking. 14-Sep-20 10:10 AM I hope the sad face is directed at the smoke 14-Sep-20 10:10 AM and not an impending disaster with my viewport 14-Sep-20 10:10 AM It's for smoke. 14-Sep-20 11:58 AM I took my PM 2.5 sensor to walmart last night... Ended up wearing my painting respirator even as I drove... Apparently the truck recirculation filter doesn't do crap, and I'm guessing the HVAC is leaky to the outside (sorta knew that before this all went down) 14-Sep-20 11:58 AM Walmart was better than outside, but still dangerous 14-Sep-20 11:58 AM I was the only one wearing a respirator 14-Sep-20 11:58 AM dog walks arent too fun, about to go on the lunch one.. everytime we leave t he house the dog sneezes 14-Sep-20 11:59 AM (and the only one I noticed with a particle sensor in their cart) 14-Sep-20 11:59 AM My kiddo has taken alright to staying in one room most of the day 14-Sep-20 11:59 AM AQI here is 185 today 14-Sep-20 12:00 PM Gives me some mental power to consider "small homes" if we ever were to move and I quit my corporate job to strike out a startup or something 14-Sep-20 12:00 PM Lol accuweather says 528 here 14-Sep-20 12:00 PM whoa 14-Sep-20 12:01 PM Accuweather also says seattle is 247 14-Sep-20 12:01 PM I use wunderground 14-Sep-20 12:02 PM Hmm, that shows 281 14-Sep-20 12:02 PM For me 14-Sep-20 12:02 PM because we have some coolness around, it actually isn't unbearable.. I mean, I spend about 2hrs outside for dog walks a day, and really only mild headaches have occured 14-Sep-20 12:02 PM not good by any means, but I can't wimp out from my duties 14-Sep-20 12:04 PM I don't care so much about the potential for headaches as much as the idea that my blood will get "gritty" and affect my heart 14-Sep-20 12:04 PM Or so they say 14-Sep-20 12:04 PM I haven't read up on the effects at all to be honest 14-Sep-20 12:04 PM Other than headlines 14-Sep-20 12:04 PM Which aren't a great source 14-Sep-20 12:04 PM Like, as a species we did use smoky campfires to cook on until pretty recently 14-Sep-20 12:05 PM it's how we heated homes, too 14-Sep-20 12:05 PM Sooo i kinda have some minor reservations 14-Sep-20 12:05 PM Yeah 14-Sep-20 12:05 PM so what if a lil smoke didnt go up the chimney 14-Sep-20 12:05 PM we also didnt live as long 14-Sep-20 12:05 PM Yeah, always a convolved infospace 14-Sep-20 12:07 PM k, dog walk time.. 14-Sep-20 12:10 PM Dog walking yesterday was the first time I bothered fitting an N95 well 14-Sep-20 12:10 PM wow they work well. 14-Sep-20 12:24 PM uni is throwing out some high vac or cryostat stuff 14-Sep-20 12:24 PM big (~ 1/2 metre) metal plate with ports on it as well as a long piece of pipe with hv flanges on both ends 14-Sep-20 12:24 PM do i want to try to get these? they're sitting outside in an open air waste container 14-Sep-20 12:30 PM photos! 14-Sep-20 12:31 PM (not entirely sure abt legality of this all, though staff is fine with students grabbing waste, it is not officially allowed) 14-Sep-20 12:31 PM Photo's not too great, but its about the pipe in top right and the big plate under the desk frame 14-Sep-20 12:31 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200914_160118-1F722.jpg 14-Sep-20 12:31 PM this is from the physics dept, who mostly do ultramicroscopy and ultra low temperature stuff afaik 14-Sep-20 12:35 PM looks like mostly junk but that might be a set of three KF25 baseplates? and a KF25 angle valve? 14-Sep-20 12:35 PM Yeah that's mostly junk it looks like 14-Sep-20 02:35 PM The photo looks like an earthquake just happened 14-Sep-20 05:18 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-FFAC4.png 14-Sep-20 05:18 PM does this seem like a reasonable way to make an automated pump down system and not blow up your turbo 14-Sep-20 05:18 PM pressure sensors would only allow the gate valve and rear turbo valve to open in the case that the chamber pressure is < 1 torr 14-Sep-20 05:19 PM you want to open and close the chamber frequently, right? 14-Sep-20 05:20 PM ideally yeah, since the small turbo takes 10m to spin down i assume the chungus turbo would take an hour 14-Sep-20 05:20 PM not good for parties 14-Sep-20 05:20 PM Then yeah, this is probably the easiest way. 14-Sep-20 05:20 PM There's specs for turbo spinup/spindown times in the data sheets often 14-Sep-20 05:22 PM i wasn't able to find much writing about the alcatel 5400 14-Sep-20 05:22 PM i did manage to sort how to get it to spin up 14-Sep-20 05:22 PM and it got to a few hundred rpm before i turned it off 14-Sep-20 05:22 PM i feel like i should have gotten the cryopump from the scrapyard also 14-Sep-20 05:22 PM it was a big CVD machine i tore down 14-Sep-20 05:22 PM but the cryopump did not have its compressors with it 14-Sep-20 05:24 PM On one hand maybe, on the other hand cryopump processes = gross 14-Sep-20 05:43 PM what's gross? 14-Sep-20 05:44 PM I may be way off, but turbopumps can only deal with harsh chemicals for so long before they're toast 14-Sep-20 05:44 PM cryopumps can handle a lot more.... which is not something you as an outsider want 14-Sep-20 05:44 PM oh 14-Sep-20 05:44 PM it was pretty clean looking 14-Sep-20 05:44 PM aquatrap 14-Sep-20 05:44 PM i just didn't want to deal with refrigerants and all the fittings etc 14-Sep-20 05:48 PM I doubt you even saved much money if there was no compressor anyway 14-Sep-20 05:48 PM And yeah, I'd be very sketched out about a CVD 14-Sep-20 05:48 PM God knows what they did in it 14-Sep-20 05:48 PM it had labels 14-Sep-20 05:48 PM @Mezmorizor you can run two cold heads off one compressor 14-Sep-20 05:48 PM so, there can be some savings... 14-Sep-20 05:49 PM argon, n2, methane, o2, couple of others 14-Sep-20 05:49 PM didn't see any arsenic MFCs in this cvd machine, 14-Sep-20 05:49 PM though there was certainly arsine handling equipment at the scrapyard 14-Sep-20 05:49 PM and whatever did this to 316SS can't be good ha (it was probably a chloride) 14-Sep-20 05:49 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/118541434_435932297324332_8323900008088419-84832.png 14-Sep-20 05:49 PM the whole situation was really sad, a bunch of people had no idea what they got their hands on and destroyed hundreds of thousands of dollars worth of stuff 14-Sep-20 05:49 PM like this $10,000 turbo 14-Sep-20 05:49 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/117237494_3060484700741632_701387173135616-EBB1B.png 14-Sep-20 05:54 PM oh my goodness 14-Sep-20 05:54 PM i warned them that some of the stuff can be toxic but, just like the shipping industry, the scrapping industry has a don't ask don't tell culture 14-Sep-20 05:54 PM so, there can be some savings... @idmb if I really need a cryo pump as well, I have one of those 70K stirling engines with a KF40 that should do a fine job 14-Sep-20 05:57 PM looks at my thing sitting at 13k right now sureeeeeeeeeee 14-Sep-20 05:58 PM lol well, 5 watts at 70k. i'm sure it'd get much colder in a chamber but i don't have any tools to measure it 14-Sep-20 05:58 PM at some point the helium will liquefy and thats probably not good for the engine 14-Sep-20 06:01 PM you need one of these: 14-Sep-20 06:01 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-0D611.png 14-Sep-20 06:01 PM capacity map 14-Sep-20 06:01 PM oh this isn't an evaporative heat pump 14-Sep-20 06:01 PM it's like, one of the sunpower single stage cryocoolers 14-Sep-20 06:01 PM this kinda thing 14-Sep-20 06:01 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/rhessi_auto2-single-stage-stirling-cryocoo-DEB91.png 14-Sep-20 06:03 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Q2gPmUON14RziZGSCu5UwE_lRDqPpZc5MMW1xrJyow-9CA3F.png 14-Sep-20 06:04 PM also an fpsc? 14-Sep-20 06:08 PM https://en.wikipedia.org/wiki/Cryocooler#GM-refrigerators 14-Sep-20 06:09 PM It's Gifford McMahon 14-Sep-20 06:09 PM ...which I now realize that wikipedia page probably says 14-Sep-20 06:09 PM i also have one of those split cycle engines that the wiki article has there as a picture 14-Sep-20 06:09 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/ew0KICAiYnVja2V0IjogImVlLWZpbGVzIiwNCiAgIm-D67E6.png 14-Sep-20 06:09 PM never got it to actually work though, it has two voice coils and I don't know the proper amplitude and phase for them 14-Sep-20 06:09 PM if anyone has one also, am very interested in scope captures 15-Sep-20 01:09 AM Anyone have specs for a jeol jsm 6600fxv? 15-Sep-20 05:50 AM Joined the server. 16-Sep-20 12:44 PM Fusion 360 users, export all your projects now! Autodesk said they said they are going to now make it impossible to export .step files or .dxf now for the personal version, bait and switch from the f360 team. 16-Sep-20 12:45 PM oh what 16-Sep-20 12:46 PM yeah, feel free to also call autodesk and give their social media pages hell 16-Sep-20 12:48 PM and bug eric wilhelm lol 16-Sep-20 12:57 PM what? 16-Sep-20 12:57 PM sigh 16-Sep-20 12:57 PM @adammunich do you have an email screenie or a link to where this was announced? 16-Sep-20 12:57 PM So I can circulate this 16-Sep-20 12:59 PM https://twitter.com/hackerfriendly/status/1306270312879722501 16-Sep-20 03:13 PM It was unfortunately always only a matter of time...sucks they decided to go this direction 16-Sep-20 03:55 PM For people using Fusion on the startup and education licenses, this change does not apply, luckily I just extended my education license about 9 months ago. 16-Sep-20 03:55 PM There are not a lot of free and competitive alternatives unfortunately... Solidworks and Fusion 360 are on a completely different tier than Onshape...etc. 16-Sep-20 04:24 PM @Noxz I’ve looked into getting a Cs beam standard. 16-Sep-20 04:24 PM The big issue is that the tubes go bad. 16-Sep-20 04:24 PM Vacuum, ion pump full, Cs depletion, etc. 16-Sep-20 04:24 PM And the cost for new tubes is ridiculous. 16-Sep-20 04:24 PM So many of the untested ones on eBay were probably scrapped because the tubes went bad. 16-Sep-20 04:24 PM And the ones found by people who know about them, shown running, cost a small fortune. 16-Sep-20 04:24 PM Don’t trust the timing signal on consumer GPS, but there are GPS boards specifically designed for precision timing. 16-Sep-20 04:24 PM Rubidium is pretty darn stable. Not as good as Cs over the long term, but it’s a lot less expensive on eBay. Lots of cell tower equipment uses it. 16-Sep-20 04:24 PM If you want something to calibrate your quartz ovens against, that would be a good choice. 16-Sep-20 04:38 PM the Cs gets used up, from what I understand, "go bad" is equivilent I suppose 16-Sep-20 04:38 PM neat @ Rb.. will look into it more 16-Sep-20 05:15 PM Rb can go bad, too, but it’s nowhere near as complicated a tube as the Cs beam. 16-Sep-20 05:15 PM That whole thing has an integrated oven, HV beam, mass spec, microwave cavity, and ion pump. 16-Sep-20 05:15 PM My understanding of Rb is that you’re using is as a discharge lamp, and the lamp is inside the microwave cavity. 16-Sep-20 05:15 PM You have an optical intensity change when the microwave freq = the hyperfine transition. 16-Sep-20 05:15 PM The irony is that in both cases, you’re using the hyperfine transition to discipline a quartz oven oscillator. The actual output of atomic clocks comes from quartz. 16-Sep-20 05:24 PM So it could be really called a "Rubidium-DO"? :D 16-Sep-20 05:25 PM I mean sure? 16-Sep-20 05:58 PM all my tools are now home.. I no longer need to go into school (except for tools I do not yet own) 16-Sep-20 05:58 PM it would be preetty neat to DIY an atomic clock reference 16-Sep-20 05:58 PM probably not all that farfetch, neither 16-Sep-20 05:58 PM handling the alkali metals used isnt a giant issue neither (inert atmosphere was something I built my fumehood specifically for, at one point) 16-Sep-20 05:58 PM I mean, care must be in place, but still 16-Sep-20 05:58 PM wow, Rb stuff on ebay is a bit cheaper 16-Sep-20 09:48 PM This one and some more like it was heading into the garbage can when a friend intercepted it. Never bothered to power it up. 16-Sep-20 09:48 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-8CCFE.jpg 17-Sep-20 05:42 PM https://www.ebay.com/itm/Leybold-XPR-TR100-Inficon-Transpector/183249380754 17-Sep-20 05:42 PM So there are some cheap RGAs on eBay right now with a pneumatic valve at a reasonable price, anyone have more info on this first generation Transpector XPR? I know it works with TWare32, but that's about it 17-Sep-20 05:42 PM @qualia Maybe you have some idea? 17-Sep-20 05:43 PM I can tell you leybold probably won't provide anything to you about it lol 17-Sep-20 05:47 PM Well I think there's a good chance that the pinout on some of the connectors would be the same as Transpector XPR2, just need to make sure I know how to power this correctly lol. It's >20 years old so I don't think any company would give a damn about it 17-Sep-20 05:47 PM And judging from the back of the unit it could have identical pinout as the TSP TH100, which I believe is the one qualia has 17-Sep-20 05:51 PM Power as in figure out which pin to put it on? 17-Sep-20 05:52 PM Yeah that's pretty much it 17-Sep-20 05:52 PM why does industry love 9 and 15 pin connectors for power? 17-Sep-20 11:14 PM @Mason_Yu I've got a TSP TC100 that I haven't looked at in like a year+ since I bought it for $250. Inficon was helpful when I sent a request through their website, replying to me within a few days and then quickly via the email conversation thereafter 17-Sep-20 11:14 PM send me some manuals at least 17-Sep-20 11:15 PM Ah manuals would be nice! 17-Sep-20 11:15 PM I found Japanese manuals for the XPR3, got most of the info I needed actually 17-Sep-20 11:15 PM """ The TC100 that you have is too old to work with TWare32 software. Sorry, but we do not have software available for you. TranspectorWare (I am told) is the name of the software that was used for this RGA, but we do not have copies to sell and not sure it would even work with today's operating systems. Someone was able to track down a scanned copy of the operating manual. """ 17-Sep-20 11:16 PM I think short RGAs like this won't have great performance, but I'm just going to use it as a vacuum gauge in the worst case scenario, hopefully it would be somewhat useful in helium leak checking 17-Sep-20 11:17 PM I really want to quit my day job to catch up on stuff like this, and maybe turn it into some income 17-Sep-20 11:17 PM I know the XPR works with TWare32 from both the old Inficon website and the manual for TWare32 17-Sep-20 11:17 PM at the same time, with day-job I can afford to willy-nilly buy stuff like this, even if it just sits on a shelf 17-Sep-20 11:19 PM Luckily I could work from home 4 days in a week, and probably for a month straight here since Wisconsin's Covid cases are spiking. Hoping to get more stuff done 17-Sep-20 11:19 PM I think I need to completely overhaul the power supply of my SEM lol 17-Sep-20 11:19 PM It arced somewhere... 17-Sep-20 11:20 PM heh, well I've been WFH for almost 3 years 17-Sep-20 11:20 PM Maybe replace it completely 17-Sep-20 11:20 PM @Mason_Yu http://i-support.sakura.ne.jp/Software/ 17-Sep-20 11:21 PM Got the Japanese manual from there 17-Sep-20 11:21 PM I downloaded that whole directory 17-Sep-20 11:21 PM a while back 17-Sep-20 11:25 PM you know 17-Sep-20 11:25 PM I could use another RGA 17-Sep-20 11:25 PM I wonder if a gamble like this is something they'd go for 17-Sep-20 11:25 PM They liked the sewer pipe. 17-Sep-20 11:26 PM I'd be really impressed if you can convince a school's purchasing department to go for an eBay listing 17-Sep-20 11:26 PM Using your group's petty cash is one thing, getting approval from purchasing is another 17-Sep-20 11:41 PM Under $3500 is fine 17-Sep-20 11:41 PM It’s just a credit card, have bought eBay before. 17-Sep-20 11:41 PM The linear rails my system is on were bought from an undergrad 17-Sep-20 11:41 PM Through the official purchasing system 17-Sep-20 11:44 PM The petty cash limit set by my school's purchasing department was $100 lol 17-Sep-20 11:44 PM Ever since the sewer pipe 17-Sep-20 11:44 PM I’ve basically had free reign 17-Sep-20 11:44 PM Above that you'd need to either go through an approval process and get 4 signatures and prove you can't buy it from approved sources, or go through the PO issuing process 17-Sep-20 11:44 PM 0 chance eBay was going to get approved 17-Sep-20 11:44 PM But then again my entire budget was probably just $3500 17-Sep-20 11:44 PM So probably a good thing I didn't get free reign, or else it would have been blown away in a month I'm sure 17-Sep-20 11:47 PM I got told the budget for my system 17-Sep-20 11:47 PM After purchasing the vacuum pumps 17-Sep-20 11:47 PM Considering them, the cold head, and MCP are about 90% of the cost.... ???? 17-Sep-20 11:47 PM But then there was a clear “oh we can get more if we need it, just be careful” 17-Sep-20 11:48 PM So what's the total budget? 17-Sep-20 11:49 PM Overall it was 2M/3 projects / 2 groups 17-Sep-20 11:49 PM Sounds about right. I took a sneaky look at the budget for a 5e10 n/s beam-on-target fusion neutron source here at work, power supplies alone are about $500k 17-Sep-20 11:49 PM ~500k for laser ~200k for droplet machine ~100k other is the breakdown for my room 17-Sep-20 11:51 PM @idmb got a pic of that sewer pipe? 17-Sep-20 11:55 PM this is where it splits to KF before the turbos 17-Sep-20 11:55 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_0251-56B54.JPG 17-Sep-20 11:55 PM an example of the flanges used 17-Sep-20 11:55 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screen_Shot_2020-09-17_at_11.56.35_PM-CB6A0.png 17-Sep-20 11:55 PM and the connection to the pump 17-Sep-20 11:55 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screen_Shot_2020-09-17_at_11.56.22_PM-72669.png 17-Sep-20 11:55 PM there are four 4" PVC lines that all run about 15m from one room to another 17-Sep-20 11:58 PM Wow such a tiny pump for so many lines 17-Sep-20 11:59 PM iGX 600L 17-Sep-20 11:59 PM Nevermind 17-Sep-20 11:59 PM the conductivity of each line reduces the pumping speed at the other end to around 100 m^3/hour 18-Sep-20 12:00 AM Yeah didn't realize that inlet is actually ISO100 18-Sep-20 12:00 AM so x4 it's around 2/3 capacity of the pump, throw in some messy PVC offgassing... seemed worthwhile 18-Sep-20 12:00 AM oh haha yeah, that's some of the rare KF50 18-Sep-20 12:00 AM in hindsight, a pneumatic valve on the ISO port would have been a good idea 18-Sep-20 12:01 AM Seems like all of these insanely fast "dry" pumps are essentially a few giant roots blower pumps coupled to a relatively small foreline pump 18-Sep-20 12:02 AM I think this is a single screw stage? 18-Sep-20 12:02 AM We also looked at the leybold screwline, but another group told us they had both and this was way better 18-Sep-20 12:02 AM extremely low maintenance 18-Sep-20 12:04 AM One potential problem if you are pumping flammable gases or if you want your vacuum really clean is that the bearings in the screw/roots blower stages may leak oil over time 18-Sep-20 12:05 AM So, when people talk about flammable gasses or corrosion 18-Sep-20 12:05 AM How much do you actually need to be pumping to care? 18-Sep-20 12:05 AM I mean it depends on what you're doing 18-Sep-20 12:05 AM The other student is using NO 18-Sep-20 12:05 AM and asked about whether they should set up purges for their turbos 18-Sep-20 12:05 AM but the amount they use is tiny 18-Sep-20 12:06 AM At work, they use 4 roots blower stages to do differential pumping on a deuterium gas target, that thing needed to have special bearing seals/dry bearings because it runs constantly under quite a high pressure 18-Sep-20 12:06 AM Purges are used on all the pumps in industrial installations I've seen 18-Sep-20 12:07 AM Any industrial setting is going to be a longer term setup though isn't it? 18-Sep-20 12:07 AM like here, the turbopump moves every 5 years 18-Sep-20 12:07 AM Yeah, especially if you're the OEM and shipping stuff for people 18-Sep-20 12:07 AM Who are expecting to use it for 20 years 18-Sep-20 12:07 AM so you basically force every grad student to minor in plumbing if you do it all properly 18-Sep-20 12:07 AM Having done the sewer pipe I would say next time just build a noise isolation box. It's water-cooled, why not? 18-Sep-20 12:09 AM That's the main difference here I feel, every change order I make needed to have two design reviews and have the equipment manual/service manual revised to include future services that may be required. That is costly but necessary to meet all the standards and so on in the nuclear industry 18-Sep-20 12:11 AM I feel like what I’d prefer is somewhere in between 18-Sep-20 12:11 AM I definitely wish there was a way to get timely feedback / suggestions 18-Sep-20 12:11 AM Discovered today that two of three turbos on the old system were installed in ways the manual said not to 18-Sep-20 12:11 AM Coincidentally, two of three have failed in the past decade 18-Sep-20 12:13 AM This happened today, that is a very bent 0.74% enriched nuclear fuel rod 18-Sep-20 12:13 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-EA27F.png 18-Sep-20 12:13 AM Luckily no external agencies need to get involved here, so it was not a big problem since the zircaloy cladding held up 18-Sep-20 12:13 AM Surprisingly easy to bend a rod actually, and they are quite malleable since the fuel is metal 18-Sep-20 12:17 AM Was that just 18-Sep-20 12:17 AM A person making a mistake? 18-Sep-20 12:17 AM It was a machine making a mistake 18-Sep-20 12:17 AM Or a machine doing a weird 18-Sep-20 12:17 AM Ah 18-Sep-20 12:17 AM You could bend that by hand if you REALLY tried 18-Sep-20 12:17 AM I’m currently in that awkward stage with my gate valves 18-Sep-20 12:17 AM Where I control them electrically 18-Sep-20 12:17 AM With no safety interlock 18-Sep-20 12:17 AM And so they get unplugged 3x when I open a chamber. 18-Sep-20 12:17 AM Because yikes 18-Sep-20 12:19 AM Don't you have a PLC doing all this interlock safety stuff? 18-Sep-20 12:19 AM Only after I make the cable 18-Sep-20 12:19 AM It’s a fake PLC too so it can make mistakes 18-Sep-20 12:19 AM Based on the mistakes I make making it 18-Sep-20 12:22 AM Huh? Fake in what sense? 18-Sep-20 12:23 AM It’s in software with some stuff made from scratch 18-Sep-20 12:23 AM Not that I think that makes the logic less robust in a meaningful way here, but stuff like identifying a disconnected gauge properly may be wonkier. 18-Sep-20 12:23 AM It’s definitely being documented as risk-reduction rather than removal 18-Sep-20 12:23 AM Most of the work was necessary for remote control anyways, that’s the main feature really. 18-Sep-20 12:23 AM If you buy a plc made for the equipment you’ve got, and ask someone competent to program the safety features you won’t, it should be pretty foolproof. 18-Sep-20 12:23 AM I’m making no such claims 18-Sep-20 12:29 AM What's the worst case situation for a vacuum failure in your case? Blow up a few turbos? Or will it damage irreplaceable equipment? 18-Sep-20 07:15 AM This happened today, that is a very bent 0.74% enriched nuclear fuel rod There’s something about it lying on a wood floor that just feels weird 18-Sep-20 08:11 AM Wherps 18-Sep-20 09:13 AM An overpressure would be pretty bad 18-Sep-20 09:13 AM But yeah in general you could break three turbos with a mistimed gate valve, and clog a little nozzle with ice if the cold head is on 18-Sep-20 09:13 AM But the nozzle isn’t that bad to replace just a huge pain. Would take less time than ordering a new turbo 18-Sep-20 09:33 AM Joined the server. 18-Sep-20 09:34 AM Hello @iz! 18-Sep-20 09:34 AM hello! 18-Sep-20 09:34 AM as mentioned on DMs 18-Sep-20 09:34 AM I was talking about semiconductor processes in #semiconductor with a bunch of other folk 18-Sep-20 09:34 AM Welcome! 18-Sep-20 09:35 AM ahhhhh 18-Sep-20 09:35 AM and yes, RE: QKD experiment - I sometimes discuss what I intend to do here as well 18-Sep-20 09:35 AM haha hello! @GigaSquirrel 18-Sep-20 09:35 AM in fact, it was someone here who gave the idea of photon counting statistics 18-Sep-20 09:37 AM ahhhhhhh 18-Sep-20 09:37 AM this is not so deep into electronics anymore than it is science and other stuff 18-Sep-20 09:37 AM also the HPDs we ordered 18-Sep-20 09:37 AM thank @GigaSquirrel for that 18-Sep-20 09:37 AM they gave me the link 18-Sep-20 09:37 AM Lasers are statistical beauties 18-Sep-20 09:40 AM oooooooo 18-Sep-20 09:40 AM cooool 18-Sep-20 09:40 AM Lasers are statistical beauties it was a new perspective for me haha 18-Sep-20 09:41 AM how's the LoRa link btw? 18-Sep-20 09:41 AM did you manage to mess with it? 18-Sep-20 09:41 AM im still studying for my tests 18-Sep-20 09:42 AM I see - studying first then! 18-Sep-20 09:42 AM Ok, I need some encouragement in the face of my wife telling me she'd divorce me if I bought and need to drive 4000 miles round trip to buy a dual beam 18-Sep-20 09:42 AM "leaving me alone during the pandemic to take care of our son" 18-Sep-20 09:42 AM Joined the server. 18-Sep-20 09:43 AM Hi there! 18-Sep-20 09:43 AM Buy an RV 18-Sep-20 09:43 AM hello! 18-Sep-20 09:43 AM Bring her with you 18-Sep-20 09:43 AM Problem solved 18-Sep-20 09:43 AM Haha, she has been saying she'd like an RV 18-Sep-20 09:44 AM And Patrick, #introductions_and_directory if you want 18-Sep-20 09:45 AM Let's see what she says to that 18-Sep-20 09:45 AM Also there are private courier options 18-Sep-20 09:45 AM People who own mid size trucks with flatbeds 18-Sep-20 09:45 AM For mini shipping containers 18-Sep-20 09:45 AM Idk cost of vehicle ownership is something like $0.5 Canadian per kilometre 18-Sep-20 09:45 AM So you can spend 3k shipping it and still be in decent shape... 18-Sep-20 09:46 AM Hmmm, when I brought my FIB home I had to crate things up. Luckily the folks I bought that from locked the chamber into shipping mode, which is something I'm not sure I can trust a shipper to ensure 18-Sep-20 09:46 AM It cost me $3k to get my FIB home, doing it myself 18-Sep-20 09:46 AM The quote I got from a shipper then was minimum $5k 18-Sep-20 09:46 AM And that was still hand wavy 18-Sep-20 09:46 AM This was for an equipment specialist 18-Sep-20 09:46 AM Or so they said 18-Sep-20 09:49 AM My experience with shipping companies would lead me to believe an "equipment specialist" probably has job responsibilities that involve something like "Yup, its equipment" and then throwing straps all over it bending a minimum of 4 important bits that should not be bent 18-Sep-20 09:49 AM lol 18-Sep-20 09:49 AM That might just be my experience(s) though 18-Sep-20 09:54 AM I would think it's worse for other stuff 18-Sep-20 09:54 AM I tried to get hard drives shipped to me from the US 18-Sep-20 09:54 AM DOA. 18-Sep-20 09:54 AM I had to talk to the company to get them to reship 18-Sep-20 09:54 AM and instruct them to package in a certain way 18-Sep-20 09:54 AM even my laser flash lamp's box arrived... not looking so much like a box 18-Sep-20 09:54 AM but because of bubble wrap and the lamp being surrounded in stryofoam then put in a pipe 18-Sep-20 09:54 AM it survived 18-Sep-20 10:06 AM It probably won't ever be your problem specifically, but you definitely want a trap for NO. At one point a lab mate screwed up and got NO into the rotary vane, and it required a full rebulid. And that's at our droplet doping pressures, so not high. 18-Sep-20 10:15 AM this is 10% NO-seeded helium going through a pulsed nozzle at room temp 18-Sep-20 10:15 AM 10Hz, source chamber pressure aroudn 1E-5 torr 18-Sep-20 10:15 AM I guess that's...A comparable pressure? 18-Sep-20 10:15 AM Foreline trap is just to slow the rate at which the NO goes into the roughing pump? 18-Sep-20 10:40 AM Maybe, I can't remember the details of what actually happened. 18-Sep-20 10:40 AM Just that the pump did not appreciate even a pretty small amount of NO 18-Sep-20 10:57 AM but was the issue just "it broke because they didn't fill the trap?" 18-Sep-20 10:57 AM Don't think so 18-Sep-20 10:59 AM it broke because they cranked the leak valve too high? 18-Sep-20 10:59 AM I'm sharing a roughing pump with this NO experiment and will tell them to use a scroll if I should actually be concerned, we do have an unused LN2 foreline trap too but.. effort 18-Sep-20 11:13 AM @polyfractal seems we're in a similar boat, I've got a biotech degree but work as software engineer in analog validation 18-Sep-20 11:14 AM I legitimately don't remember what they did. I just remember what the oil looked like even after multiple changes 18-Sep-20 11:15 AM Hmm 18-Sep-20 11:17 AM @nmz787 nice! that sounds more fancy than me, I just do search analytics stuff 18-Sep-20 11:17 AM i worked in a wet lab for a few years while bulking up my resume for grad school, but decided to bail for greener pastures 18-Sep-20 11:32 AM I went back to the scrap yard and not only is the stuff that was here last time, still here there's a lot more vacuum stuff floating around 18-Sep-20 11:32 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200918_113234-30F08.jpg 18-Sep-20 11:35 AM im jelly of folks that have cool things in their scrap yards. just rusty trucks here 18-Sep-20 11:36 AM I got into software pretty much right after undergrad, couldn't get a job in a lab (even the minimum wage tech positions) so fell back on my programming experience 18-Sep-20 11:36 AM Paid off my student loans pretty fast doing that tho 18-Sep-20 11:36 AM I also am building a vacuum chamber for coating and etching 18-Sep-20 11:38 AM If anybody's looking for parts let me know 18-Sep-20 11:48 AM @nmz787 yeah i was sorta sad to leave at first, but the paychecks made up for it after a while was living at practically poverty level as a lab tech 18-Sep-20 11:48 AM you planning to do thermal or sputter coating? 18-Sep-20 11:49 AM Huh, the bot censored w t f 18-Sep-20 11:50 AM o.O 18-Sep-20 11:50 AM bad bot 18-Sep-20 11:50 AM Was saying nyc was offering like $28k/year and then we moved to Oregon after 3 months living there 18-Sep-20 11:50 AM Thinking to try both 18-Sep-20 11:50 AM Got an ICP plasma source to play with 18-Sep-20 11:50 AM 1000W RF generator and match network 18-Sep-20 11:51 AM oooh nice! RF side of things is all a mystery to me, really need to do some reading on how any of that works, what equipment's involved 18-Sep-20 11:52 AM I found the right thing for my big vacuum chamber! 18-Sep-20 11:52 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200918_114836-B18FD.jpg 18-Sep-20 11:52 AM Since they don't make 12" Quick access door, next best thing 18-Sep-20 11:53 AM @polyfractal tbh RF in sputtering, etc is something I'd like to figure out also 18-Sep-20 11:53 AM because in comms engineering we're used to working with matched loads and antennas 18-Sep-20 11:54 AM @adammunich is that like a giant gate valve? 18-Sep-20 11:54 AM Yes 18-Sep-20 11:54 AM wow, nice find 18-Sep-20 11:54 AM from my understanding of RF plasma applications, I am sure it isn't matched loads, etc 18-Sep-20 11:54 AM so I want to understand things like radiation efficiency, etc in such applications 18-Sep-20 11:55 AM @SleepyOwl Joyce I understood a few of those words haha i definitely have a lot of reading to do 18-Sep-20 11:56 AM It's a 12" CF so I don't need to spend $800 on a blank flange lol 18-Sep-20 11:56 AM simply what I am talking about is impedance matching haha 18-Sep-20 11:56 AM where the impedance of say, an antenna is matched to a transmitter 18-Sep-20 11:56 AM when that happens, most of the RF power is radiated from the antenna 18-Sep-20 11:56 AM in an unmatched antenna/load 18-Sep-20 11:56 AM some of the transmitted power is reflected from the antenna/load 18-Sep-20 11:56 AM which makes transmission inefficient 18-Sep-20 11:56 AM and in some circumstances, the reflected power and the forward power constructively interfere and can damage the transmitter itself 18-Sep-20 11:58 AM ahh, ok i see 18-Sep-20 11:59 AM so I am interested to learn about the electronics in RF plasma applications 18-Sep-20 11:59 AM where the load/antenna does not seem matched 18-Sep-20 11:59 AM thanks for the eli5 18-Sep-20 12:00 PM again this is from my perspective as someone who has studied and done comms engineering 18-Sep-20 12:00 PM I am not really sure about applications like plasma sputtering 18-Sep-20 12:00 PM maybe I will take a look in a bit and read papers 18-Sep-20 12:00 PM also iirc 18-Sep-20 12:00 PM I think Applied Science or someone else did magnetron sputtering 18-Sep-20 12:00 PM The Thought Emporium it was 18-Sep-20 12:00 PM https://www.youtube.com/watch?v=Cyu7etM-0Ko 18-Sep-20 12:09 PM https://www.youtube.com/watch?v=9OEz_e9C4KM Both 18-Sep-20 12:09 PM so Applied Science goes in depth about the setup: https://www.youtube.com/watch?v=5X0EKbpLuRc 18-Sep-20 12:09 PM this seems to be a 13.56 MHz RF sputtering setup 18-Sep-20 12:09 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-5B88C.png 18-Sep-20 12:09 PM so from what I see, this is a RF power amplifier that generates 13.56 MHz 18-Sep-20 12:09 PM and an adjustable tuner for the impedance matching 18-Sep-20 12:20 PM Yeah, I thought they were pretty low frequency, at least compared to almost all communication stuff 18-Sep-20 12:20 PM @GigaSquirrel you've got an old heathkit tuner you use right? 18-Sep-20 12:21 PM you can get a lot of these tuners for cheap 18-Sep-20 12:21 PM just get them off some ham who's selling their stuff 18-Sep-20 12:22 PM cheap ham selling their stuff until coronavirus is over and hamfests return I can't really imagine those words going together honestly 18-Sep-20 12:22 PM Aye, I do 18-Sep-20 12:23 PM @rfs just returned from one I think 18-Sep-20 12:23 PM Well I stand corrected then 18-Sep-20 12:23 PM (I can't stand the used ham radio equipment market in general) 18-Sep-20 12:24 PM why so? 18-Sep-20 12:25 PM "I was generous and sold it for less than I bought it for" 18-Sep-20 12:25 PM Words I've heard before and feel like I see in practice way too often 18-Sep-20 12:27 PM most "hard core" ham folks are grumpy old men who have lost all connection to real life 18-Sep-20 12:27 PM in my experience 18-Sep-20 12:27 PM being a ham radio op myself, I see that myself 18-Sep-20 12:27 PM gear sold for a lot more than they should 18-Sep-20 12:27 PM but anyway 18-Sep-20 12:27 PM tuner circuits 18-Sep-20 12:27 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/mfj949-B99E0.png 18-Sep-20 12:27 PM that's really all it is to it 18-Sep-20 12:27 PM could probably even DIY one quite easily 18-Sep-20 12:32 PM RF plasma stuff can be matched with a tuner 18-Sep-20 12:32 PM Changing the gas and pressure changes the tuning tho 18-Sep-20 12:32 PM so I assume you'd adjust the matching then 18-Sep-20 12:33 PM Well, both... You set the gas and pressure according to your process, then the tuner to keep your generator healthy 18-Sep-20 12:34 PM I would assume it's more for just ensuring that the most RF power is transferred to the load 18-Sep-20 12:34 PM Variable caps basically and inductors is mostly all it is... HV rated components, plus the reflection meter (swr) 18-Sep-20 12:34 PM Well, you can also damage your rf supply 18-Sep-20 12:34 PM could probably even DIY one quite easily Oh totally, just need a big enough variable capacitor 18-Sep-20 12:35 PM I think my matcher has var cap and var inductor 18-Sep-20 12:35 PM I haven't actually opened it up since purchasing 18-Sep-20 12:35 PM most RF transmitters have an output imp. of 50 + j0 ohms 18-Sep-20 12:35 PM so you're going to have to match it to that, depending on how the load presents itself as 18-Sep-20 12:35 PM so you would want both "variable" inductors and variable capacitors 18-Sep-20 12:37 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-000DC.jpg 18-Sep-20 12:37 PM For anyone else curious 18-Sep-20 12:38 PM yeah - just about as simple as it gets 18-Sep-20 12:38 PM so you just need a sizable RF generator at 13.56 MHz 18-Sep-20 12:38 PM in Applied Science's video 18-Sep-20 12:38 PM Ben uses 40 W RF power 18-Sep-20 12:38 PM I wonder what changing the RF power does, if you made it higher or lower 18-Sep-20 12:41 PM no idea, I'm familiar ish with RF stuff but sputtering itself is far outside what i'm familiar with 18-Sep-20 12:44 PM https://www.hindawi.com/journals/acmp/2012/651587/ 18-Sep-20 12:44 PM seems like RF sputtering power affects the deposition rate 18-Sep-20 12:44 PM As the RF power increases up to 300 W, the crystallinity of the film is improved and the crystalline size becomes larger. That is, the increment in sputtering power promotes the growth of crystalline and induces an improvement in crystallinity of the film. However, the excessive supply of RF power over than 300 W may cause a degradation of the preferred orientation and limits the growth of crystalline grain, resulting in the high defect density and small grain size. The film will suffer from the bombardment of highly energized particles, resulting in internal defects of the film. 18-Sep-20 12:48 PM Heh mine is 1kW 18-Sep-20 12:48 PM And I've got an auto match, tunes for me if working properly 18-Sep-20 12:48 PM You need more power with more gas pressure 18-Sep-20 12:50 PM I am also reading this at the moment 18-Sep-20 12:50 PM https://www.ias.ac.in/article/fulltext/sadh/034/04/0543-0556 18-Sep-20 12:50 PM checks out it seems 18-Sep-20 12:50 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-BFFB5.png 18-Sep-20 01:55 PM ok so this goes back to my "knows nothing about RF"... if you don't want an all-in-one unit like that 13.56mhz power source above, you could string together signal generator + rf amplifier right (plus a tuner)? 18-Sep-20 02:07 PM yeah you could, if your signal generator is capable of driving the rf amplifier 18-Sep-20 02:10 PM cool. no immediate purchases for me, but i'll keep an eye out. looks like those dedicated 13.56mhz units are a pretty penny ($700+ USD). did some light reading and I guess DC sputtering is preferred for metals, RF is better for dielectrics. so might just try out DC first, should be a bit easier/cheaper 18-Sep-20 02:11 PM cool! 18-Sep-20 02:11 PM or if you're into electronics 18-Sep-20 02:11 PM https://www.ee.columbia.edu/~harish/uploads/2/6/9/2/26925901/c15.pdf <-- DIY 18-Sep-20 02:13 PM tempting! my electronics skills are somewhere between "acceptable" and "might die touching the wrong thing" so hmm 18-Sep-20 02:14 PM I was thinking of like a 13.56 MHz oscillator then fed to a class D/E amplifier 18-Sep-20 02:14 PM One such device meant for switching amplifiers upto 1.7 kW power in HF range is push pull hybrid DRF1300; It contains two high power gate drivers and two power MOSFETs in a singlepackage 18-Sep-20 02:14 PM Wew 18-Sep-20 02:17 PM $286 oh boy. that's a serious chip 18-Sep-20 02:18 PM you could go for these kit stuff 18-Sep-20 02:18 PM https://www.ebay.com/itm/A600-LDMOS-linear-amplifier-kit-600W-1-8-72MHz-for-QRP-FT-817-KX2-KX3-X5105/264727022699?hash=item3da2f5cc6b:g:4UMAAOSwI~teUlTw 18-Sep-20 02:18 PM 24dB typical gain, needs less than 5W drive 18-Sep-20 02:18 PM that's just the lazy way of going about it 18-Sep-20 02:18 PM cause these Class AB amplifiers are not that efficient compared to Class D/E designs 18-Sep-20 02:20 PM <-- is lazy 18-Sep-20 02:20 PM interesting, bookmarking! 18-Sep-20 02:21 PM so what you do is just get a tuner like some MFJ thing 18-Sep-20 02:21 PM connect that, done 18-Sep-20 02:22 PM and a decently beefy DC power supply it looks like. 18-Sep-20 02:22 PM that definitely looks pretty low effort and modestly priced 18-Sep-20 02:22 PM has enough WIP projects, trying to minimize extras :D 18-Sep-20 02:23 PM https://www.ebay.com/itm/MFJ-941E-Versa-Tuner-II-HF-300-Watts-With-Mini-Cross-Meter-4-1-Balun/131717353091?hash=item1eaaf74e83:g:2J0AAOSweuxWT44n <-- one of the MFJ tuners would do 18-Sep-20 02:23 PM has cross forward and reverse power meter also 18-Sep-20 02:23 PM although only rated for 300w 18-Sep-20 02:23 PM tuning would be simple 18-Sep-20 02:23 PM tune it such that the reverse power is the lowest as you can get it 18-Sep-20 02:23 PM cause reverse power means power is being reflected back to your transmitter 18-Sep-20 02:28 PM mm makes sense. RF is such dark voodoo magic 18-Sep-20 02:28 PM not exactly to me at this point 18-Sep-20 02:28 PM what, are you going to burn me at the stake now? 18-Sep-20 02:28 PM Witchcraft, you say! Witchcraft! 18-Sep-20 02:34 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/witch-trial2-CB60F.png 18-Sep-20 02:35 PM although I must say 18-Sep-20 02:35 PM reflections of waves doesn't just happen with RF 18-Sep-20 02:35 PM https://www.youtube.com/watch?v=DovunOxlY1k <-- happens with mechanical waves too 18-Sep-20 02:35 PM or even sound waves, etc 18-Sep-20 02:36 PM yeah, and tbf it sorta breaks my brain that optical wavelengths (which I feel like I have a good understanding of) are just different electromagnetic energy. it's all the same, but yunno... different 18-Sep-20 02:37 PM and go high enough 18-Sep-20 02:37 PM you get into #radiation territory 18-Sep-20 02:37 PM of course, by that I mean ionizing radiation 18-Sep-20 02:37 PM not the "5G comms is gonna cause disease and cancer" rubbish 18-Sep-20 02:39 PM everything is ionizing radiation if you have enough power density 18-Sep-20 02:40 PM I mean yeah - but I am talking about more common circumstances 18-Sep-20 02:40 PM hehe 18-Sep-20 02:41 PM and you don't need too much power to hurt yourself 18-Sep-20 02:41 PM 50/60 Hz 230v/115v AC is good enough for that 18-Sep-20 02:41 PM but I digress (and no please don't try that) 18-Sep-20 02:42 PM instructions unclear, sticking fork in electrical socket 18-Sep-20 02:45 PM anyway - as per our discussions earlier, you can probably tell I'd like to understand plasma stuff for sputtering and even etching of semiconductor stuff 18-Sep-20 02:45 PM the gases though :/ 18-Sep-20 03:21 PM Heh I got my 13.56MHz generator for free from a kindly professor 18-Sep-20 05:23 PM Oh man I got a 6.5 kilowatt RF machine I haven't powered up yet 18-Sep-20 05:23 PM MKS, self tuning which is like really scary 18-Sep-20 05:23 PM I don't have three phase I'm not sure if it will be unhappy about being fed single phase yet or not 18-Sep-20 05:23 PM *MKS surepower 18-Sep-20 05:23 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200831_205455-3429B.jpg 18-Sep-20 05:23 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200831_210159-3D1E8.jpg 18-Sep-20 05:23 PM Here's what the guts look like if anybody's curious 18-Sep-20 05:23 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200831_205622-B8E6B.jpg 18-Sep-20 05:23 PM They did some pretty gnarly gold on ceramic circuit board stuff 18-Sep-20 05:23 PM I guess presumably the dielectric losses of fr4 were too high 19-Sep-20 11:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200918_184721-1D4E2.jpg 19-Sep-20 11:02 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200918_184710-3FFE2.jpg 19-Sep-20 11:02 AM So are vibration dampers recommended on turbo connections? 19-Sep-20 11:02 AM I have this damper, but its inner diameter is smaller than my large turbo diameter, which is kind of weak 19-Sep-20 11:02 AM I feel like that gate valve is going to vibrate though when it gets closed and locked 19-Sep-20 11:05 AM It's not necessary for every application, I think a rigid mount for your turbo is more important than any other factor in terms of protecting the turbo. These bellows are mostly meant to isolate vibrations from your chamber 19-Sep-20 11:06 AM @Mason_Yu I guess mounting the turbo on the top of the chamber is also really smart so stuff doesn't get stuck inside 19-Sep-20 11:07 AM If your turbo allows this mounting orientation, then yes 19-Sep-20 11:08 AM When I took it off the machine it was installed sideways so I'm going to go with yes 19-Sep-20 11:08 AM At the very least it can handle sideways 19-Sep-20 11:09 AM Many turbos cannot be mounted on the top of the chamber 19-Sep-20 11:09 AM Sideways and inverted are totally different matters...also a lot of turbos want things within a specific radial orientation if they are on their side 19-Sep-20 11:10 AM I'll stick with sideways which is how I found it then 19-Sep-20 11:10 AM At least the 6" turbo 19-Sep-20 11:10 AM Alcatel 5400 19-Sep-20 11:10 AM On some turbos the orientation of the outlet port matters if you have it mounted horizontal 19-Sep-20 11:10 AM Those bellows / vibration dampers are also super useful for mounting chambers together 19-Sep-20 11:10 AM Since they let you build a frame and mount each chamber to the frame with them “nominally” aligned in x/y/z/tilt 19-Sep-20 11:10 AM And then are flexible enough to compensate 19-Sep-20 11:10 AM Whereas normally you’d be stressing stuff a lot when you tighten the gaskets if you did that 19-Sep-20 11:14 AM Well shoot I forgot what side the exit port was on the CVD machine 19-Sep-20 11:15 AM Manuals exist 19-Sep-20 11:15 AM They’re just hard to find 20-Sep-20 11:07 AM @polyfractal so I was looking at RF amplifiers because of our discussion the other day 20-Sep-20 11:07 AM https://www.digikey.com/products/en?keywords=IXZ2210N50L2&v=1898 <-- I found this cheap dual N-ch MOSFET 20-Sep-20 11:07 AM I am pretty sure this could be made into a class E amplifier of sorts 20-Sep-20 11:19 AM also needs a good MOSFET driver: https://www.digikey.com/product-detail/en/ixys-rf/IXRFD630/IXRFD630-ND/5214467 20-Sep-20 11:49 AM @Mason_Yu my turbo is just hanging off my FIB without rigid mounting, which is how seiko designed it 20-Sep-20 11:50 AM So it doesn't have any vibration dampening between the turbo and the FIB column? 20-Sep-20 11:50 AM And I guess there's no large pneumatically actuated gate valve that can cause vibrations in your FIB, so it would be fine for the turbo in that case. 20-Sep-20 11:54 AM @nmz787 what turbo/controller do you have? 20-Sep-20 11:55 AM It's got a vibe dampener 20-Sep-20 11:55 AM I saw Seiko and am wondering if I have stuff to offer you that may be of interest 20-Sep-20 11:56 AM But a vibration dampener is not rigid, so the turbo is just literally hanging freely? 20-Sep-20 11:56 AM I'm getting bored of tetris. 20-Sep-20 11:56 AM I think he meant an internal vibration damper between the flange mount and the bearings/blades 20-Sep-20 11:57 AM Well that means the turbo must be really resilient to shock already, which definitely cannot be said in general for all turbos 20-Sep-20 11:57 AM A FIB isn't exactly a piece of machinery that produce great mechanical shock or vibration 20-Sep-20 11:59 AM Edwards Stp 451 20-Sep-20 11:59 AM Yeah specifically meant for electron microscopes and low-vibration applications 20-Sep-20 12:02 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190927_142419-6D8DB.jpg 20-Sep-20 12:02 PM Really need to organize my photos 20-Sep-20 12:02 PM It shouldn't have taken me 8 minutes to scroll through photos to find that 20-Sep-20 12:02 PM Oh, it is actually just literally hanging 20-Sep-20 12:03 PM Load lock turbo also just hanging 20-Sep-20 12:03 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190927_142538-65BCB.jpg 20-Sep-20 12:03 PM Those vibration dampeners have locking ribs inside for a reason 20-Sep-20 12:03 PM I think you can only get away with this in a FIB or a SEM type application 20-Sep-20 12:04 PM Another angle of the bottom area a bit better 20-Sep-20 12:04 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20190927_142331-8B2EF.jpg 20-Sep-20 12:04 PM The bolts at the bottom are for shipping 20-Sep-20 12:04 PM And you remove them when in operation? 20-Sep-20 12:05 PM oh I thought it was a seiko turbo 20-Sep-20 12:06 PM Nah the fib is a seiko 20-Sep-20 12:06 PM Nah just loosened them a lot for operation 20-Sep-20 12:06 PM Good tip! I should do the same for my SEM 20-Sep-20 12:06 PM What applications couldn't you get away with hanging a turbo for? 20-Sep-20 12:07 PM Anything that could produce a mechanical shock, or any mobile system 20-Sep-20 12:07 PM I mean, you never want them to experience shock 20-Sep-20 12:07 PM Sometimes it's just not avoidable 20-Sep-20 12:07 PM Having a more rigid connection seems useful only if you need the support for a large massive turbo 20-Sep-20 12:07 PM Like for the weight 20-Sep-20 12:08 PM Pneumatic gate valves, in my case I have everything on a mobile cart, so you just can't have things hanging freely, especially if it is a huge gyroscope 20-Sep-20 03:09 PM Turns out CF flanges don't pump very well when you tighten 0 bolts 21-Sep-20 02:29 AM I wonder if a big enough flange cuts under atmospheric pressure 21-Sep-20 02:29 AM assuming the knife size stays the same the force applied should grow with r², and the knife "length" and therefore force needed should grow with r¹ 21-Sep-20 02:52 AM @GigaSquirrel For regular copper gasket, I wouldn't believe that. According to quick google, 607 N/mm of force is needed to fully cut CF knife. For CF250 flange, this gives ~150 kN to cut, but atmospheric pressure gives just ~5 kN of force... However for annealed copper gasket, this may be possible... 21-Sep-20 06:05 AM Joined the server. 21-Sep-20 06:05 AM Hi @Foxx! 21-Sep-20 06:05 AM You made it! 21-Sep-20 06:05 AM Thanks for the invite 21-Sep-20 06:05 AM but yeah, we were discussing semiconductor fab stuff in #semiconductor 21-Sep-20 06:06 AM Though I'll be honest, I'll mostly be lurking. As you know I'm just hella busy with life 21-Sep-20 06:06 AM yeah I am aware 21-Sep-20 06:06 AM but still, this place is a great resource for a lot of things 21-Sep-20 06:07 AM I can see, I'm glad to be here. It will take me a while to catch up 21-Sep-20 06:07 AM I've been in too many bleh discord servers that have gone to lately. 21-Sep-20 06:08 AM ah 21-Sep-20 01:46 PM Totally random question out of nowhere.... 21-Sep-20 01:46 PM Let's play "Name this connector" 21-Sep-20 01:46 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200921_164318-FA9CA.jpg 21-Sep-20 01:46 PM Typical IDE header. Iirc 2.54mm standard. I only know it as "IDC" cables? 21-Sep-20 01:47 PM "get a bunch of push-on connectors" 21-Sep-20 01:47 PM This is the control head for my 3d printer. I'd like to put it on an extension 21-Sep-20 01:47 PM Might grab some old 40pin 2.54mm IDE cable and cut it down to 18p layout 21-Sep-20 01:47 PM Solder up a 2-row female pin header together to make a F-F gender bender.... jank af but its what I can do with parts on hand 21-Sep-20 01:47 PM Was thinking I could possibly score an 18p idc cable, but I feel as if that is the wrong term 21-Sep-20 01:59 PM I kinda feel bad ripping up all my OG pc cables. My stash and stockpiles are getting low 21-Sep-20 01:59 PM And dont feel like ordering 50 off Amazon when I need ... 1 21-Sep-20 02:02 PM It may be easier to buy connectors like these: https://www.mouser.de/ProductDetail/Wurth-Elektronik/61201623021?qs=ZtY9WdtwX57DLOr1z4RBOw%3D%3D and make the cable yourself. It's very easy to connect a flat ribbon cable to such a IDC connector 21-Sep-20 02:07 PM Yeah I know. Just only need 1 Male and 1 female tho. 21-Sep-20 02:07 PM Just need an 18 inch extension cable. 21-Sep-20 02:07 PM It's not a high priority. But would make using the thing a bit easier 21-Sep-20 02:07 PM Tbh if I wanted a nice neat clean cable, I need pin header on one end, IDC on the other 21-Sep-20 02:09 PM afaik those IDC things with ribbon cable exist with both genders 21-Sep-20 02:09 PM Oh, yeah, got tons of pin headers. 21-Sep-20 02:09 PM That's why I figure I'll nab an old floppy cable and cut the idc down to 18 pin, and solder a pin header up. 21-Sep-20 02:09 PM Maybe use some prototype board if I'm feeling fancy 21-Sep-20 02:09 PM But one day I know I'll regret chop-shopping all my old OG PC cables 21-Sep-20 02:11 PM yup, like that one: https://www.mouser.de/ProductDetail/Wurth-Elektronik/61201625821?qs=PhR8RmCirEaviCW3wSpFww%3D%3D 21-Sep-20 02:12 PM I have the 16p version of the connector on hand. 21-Sep-20 02:12 PM But like I said, I just need 1 male, 1 female. 21-Sep-20 02:12 PM You'll probably reggret "chop-shopping" as soon as you do soldering on those ribbon cables. It can be done, but using the connectors knives is much handier 21-Sep-20 02:12 PM Too bad I cant get samples off Molex anymore 21-Sep-20 02:12 PM I'm pretty good with an iron. 21-Sep-20 02:12 PM I've dealt with 44 pin laptop ide cable mods 21-Sep-20 02:12 PM I like to hardware hack stuff like thin clients and game consoles. 21-Sep-20 02:15 PM I've done such stuff too. In my experience it's better to use ribbon-cable connectors if possible. It's much quicker. But of course it's often more available to just solder on 21-Sep-20 02:15 PM Indeed 21-Sep-20 02:15 PM I can order the part from Ebay China and wait 3 months to do a proper crimped cable... 21-Sep-20 02:15 PM Or hit the bin of parts and jank it together now 21-Sep-20 02:15 PM One of my many mods https://goo.gl/photos/VRewhDVa3J9GTEX4A 21-Sep-20 02:15 PM So basically that's a 400mhz AMD x86 tablet.... 21-Sep-20 02:15 PM The Disk on Module is a half height 44 pin 2mm ide connector... 21-Sep-20 02:15 PM Couldn't source a header for the DoM and surgery to swap was high risk low reward, and costly 21-Sep-20 02:15 PM So I just soldered the IDE cable to the maimboard and left it dangling 21-Sep-20 02:15 PM The case mod was enough strain relief to crimp a 44p ide header and add a compact flash adapter 21-Sep-20 02:15 PM From 512mb to 8gb 21-Sep-20 02:19 PM With that super special IDC plug to ribbon thing that I searched from mouser I'd probbaly rather do soldering as well, as it's quite a special and expensive part. Getting just the right connector delivered is sometimes much more annoying 21-Sep-20 02:20 PM When I had my own website and domain, I was on the sample parts white list with many OEMs 21-Sep-20 02:20 PM Nice! Looks like that thing would have had no future without such an upgrade... 21-Sep-20 02:21 PM I could have just hit moles for some samples 21-Sep-20 02:21 PM Molex** 21-Sep-20 02:21 PM I can do some things using my universities' e-mal address 21-Sep-20 02:21 PM Get in with molex 21-Sep-20 02:21 PM They usually whitelist .edu 21-Sep-20 02:23 PM I don't need any parts from them atm 21-Sep-20 02:29 PM When I've done mods to the 44p ide headers in thin clients, I have to make my own ide cables. I've had to order samples of all sorts of variants 21-Sep-20 02:29 PM So many small changes and features that can make or break a project 21-Sep-20 02:29 PM And I didnt just leech off the free samples. I would give molex due credit for the source part in videos 21-Sep-20 05:47 PM @Foxx While Molex might not do samples, Samtec does. 21-Sep-20 06:21 PM Well, its just that some years ago the whole concept of abusing the free part samples hit mainstream haxx0r-dumb and a lot of OEMs started to clamp down on restrictions 21-Sep-20 06:21 PM I've run into people that made bots to order samples en mass to 100+ accounts just to repost the items on Ebay 21-Sep-20 06:21 PM Hoktek, Foxconn, moles, for the longest time didnt care if you had Yahoo or hotmail 21-Sep-20 06:21 PM Molex* 21-Sep-20 06:31 PM And if the abuse was that bad, I can understand the current restrictions. 21-Sep-20 06:31 PM And yea many had limits on hotmail and yahoo 21-Sep-20 06:31 PM But back in 2004 gmail worked a treat, as it was new enough back then :) 21-Sep-20 06:31 PM Tho I also used my school mail for some :D 21-Sep-20 06:32 PM same 21-Sep-20 06:32 PM I got some high power RF FETs from sample orders 21-Sep-20 06:32 PM like BLF188XR series from NXP 21-Sep-20 06:58 PM That is legit epic 21-Sep-20 06:58 PM Because they are VERY stingy with samples of those if you are not well established. 21-Sep-20 06:58 PM My BLF188XR is salvage from a DVB-T2 transmitter 21-Sep-20 06:59 PM oh cool! 21-Sep-20 06:59 PM I no longer have the BLF188XR with me 21-Sep-20 06:59 PM but I wonder how it performs for Class D/E applications 22-Sep-20 10:15 AM @idmb so on the topic of the conception of QC, Feynman seems to actually ask about the limitations of computing and stuff like that 22-Sep-20 10:15 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200923_011327-EB9EB.jpg 22-Sep-20 10:15 AM There probably are people who asked the question earlier than Feynman for sure 22-Sep-20 10:15 AM (excerpt from the book: Feynman and Computation - Exploring the limits of computers) 22-Sep-20 10:15 AM goes and takes a nap 22-Sep-20 10:15 AM So physical 22-Sep-20 02:20 PM Going to say this here because it has nothing to do with semiconductors, but I'd say quantum computing really became a serious proposal in the 50s when people started working on quantum foundations and realized that it's actually just a class of probability theories. 22-Sep-20 02:20 PM From there using it for computation is pretty natural 22-Sep-20 02:20 PM As an idea at least 22-Sep-20 02:48 PM yeah - there's really nothing to do with semiconductors 22-Sep-20 02:48 PM it just became a discussion there 23-Sep-20 10:33 AM Could anyone tell me about common pitfalls in buying CF gaskets on Ebay? I'm fixing to get 10-packs in several sizes, but I don't want to waste $50 if it's just barely not the right dimension, or too thick for some reason or other. 23-Sep-20 10:35 AM afaik the size is always the same 23-Sep-20 10:35 AM as in every cf100 gasket fits every cf100 flange 23-Sep-20 10:36 AM would 'dirty' copper be a problem, you think? 23-Sep-20 10:37 AM can always be cleaned 23-Sep-20 10:37 AM Oh, meant not 100% copper 23-Sep-20 10:38 AM there are silver plated ones but if it's some alloy I wouldn't trust it to be soft enough 23-Sep-20 10:39 AM Mkay, if it's 'dirty', it's probably small amounts, anyways 23-Sep-20 10:39 AM I suppose the only thing that matters is if the two sides that get cut into are as flat as can be. 23-Sep-20 10:41 AM afaik cf is quite forgiving 23-Sep-20 10:41 AM it just has to be soft enough to actually be cut 23-Sep-20 10:42 AM cool, thanks! 23-Sep-20 10:46 AM CF gaskets vary in ID 23-Sep-20 10:46 AM If you're not going UHV I recommend these though: https://www.lesker.com/newweb/flanges/hardware_cf_gaskets.cfm?pgid=fluorocarbon2 23-Sep-20 10:48 AM Like, a CF6 gasket might have different ID's from one to the next on Ebay, or between Leskers and Duniways? 23-Sep-20 10:48 AM All. It only matters if you're trying to match tube ID perfectly 23-Sep-20 10:48 AM they vary because some people really make the tube ID as large as possible, and you don't want your gasket sticking out into the tube / the gasket only really matters on the knife edge part, so they truncate it a bit. irrelevant really, but they're not quite allll the same 23-Sep-20 10:49 AM Okay, makes sense. 23-Sep-20 10:49 AM The OD has to match, though 23-Sep-20 10:50 AM Yeah and is always by nominal size. Note that metric / imperial nominal sizes are different, metric tends to be tube ID while imperial is flange OD 23-Sep-20 10:50 AM so CF 100 is ~100mm tube which is ~ 4 inches, and you use a 6" OD flange on a 4" tube. VAT sell their gate valves by tube size but in metric, so a CF6 gate valve sold by VAT is actually an 8" OD conflat flange. Everywhere else does it the other way though, afaik 23-Sep-20 10:50 AM If you're baking a ton to go well into UHV you probably care about the gasket quality, if not then you shouldn't worry. 23-Sep-20 10:59 AM Well I'd like to see how far I can get, at this point. Unfortunately everything's been sitting in a storage space since before me, so I'm sure dust is going to be frustrating to deal with. 23-Sep-20 10:59 AM Would dust particles kill a turbo, or does that depend on the turbo? 23-Sep-20 11:01 AM You mean just from having the turbo sitting around with the inlet uncovered and accumulating dust? 23-Sep-20 11:01 AM or if you try to pump a chamber full of dust without washing it first? 23-Sep-20 11:11 AM Both, in a way. I understand I'll need to clean all of these components very deeply and carefully before I put anything together, but if I don't do a good job, or it's my first time, would stray dust that didn't get cleaned break something? 23-Sep-20 11:15 AM Shouldn't be an issue so long as you don't leave huge gobs of stuff to fall. 23-Sep-20 11:15 AM Like if you washed it super thoroughly then dried with regular paper towel and left chunks... 23-Sep-20 11:17 AM I understand you should be doing all the drying with kimwipes 23-Sep-20 11:36 AM Or just a heatgun. 23-Sep-20 11:37 AM ooh, that's good 23-Sep-20 11:37 AM Just washing stuff in a sink with soapy water, then water, then heat gunning it a lot, then pumping it a day or two later would be fine. It will take a lot longer to get down than if you use better stuff, but it will work. 23-Sep-20 11:37 AM and by a lot I mean a couple days to -7/-8 torr, instead of an hour or two. going much lower needs it cleaner but really if the chamber has been sitting around a long time you probably want to bake it... 23-Sep-20 11:44 AM Better cleaning practices or just better materials that the stuff is made out of? 23-Sep-20 11:45 AM cleaning practices 23-Sep-20 11:45 AM Right 23-Sep-20 11:45 AM make sure it all pumps down nicely with your roughing pump, of course 23-Sep-20 11:46 AM Roughing pump needs some rework or cleaning or something 23-Sep-20 11:46 AM The thing jumps around in the 1T to 100mT range 23-Sep-20 11:46 AM That's going to be a whole project 23-Sep-20 11:46 AM I'd like to drain and strain all the oil, then check the vanes or whatever's inside for damage. 23-Sep-20 06:00 PM Well damn, FedEx never delivered my 14-in flange they just threw it on the street and left, at the wrong house entirely 23-Sep-20 06:01 PM darn, are you able to do anything about it? 23-Sep-20 06:02 PM No I think some scrapper picked it up or something, apart from doing a credit card charge back not much I can do huh 23-Sep-20 06:02 PM Anybody got a 13.25" bored flange blank laying around 23-Sep-20 06:26 PM Joined the server. 23-Sep-20 06:26 PM Hello @cenobyte! 23-Sep-20 06:26 PM Hi @SleepyOwl Joyce 23-Sep-20 06:26 PM what's this place? lol I have so many discord servers now 23-Sep-20 06:26 PM so I am discussing some of the stuff like semiconductor manufacturing and other things here 23-Sep-20 06:26 PM I also discuss some aspects of our QKD experiment here 23-Sep-20 06:27 PM Cool cool 23-Sep-20 06:27 PM it's just really more science stuff here? 23-Sep-20 06:27 PM Does Connor hang out here too? 23-Sep-20 06:28 PM @Conmega hi? 23-Sep-20 06:28 PM nice (well he might be busy lol) 23-Sep-20 06:28 PM two nights ago a bunch of us were briefly discussing some QC stuff 23-Sep-20 06:29 PM cool...that's why he's got it on his Twitter 23-Sep-20 06:29 PM but in any case 23-Sep-20 06:29 PM remember we talked about all the photon counting statistics stuff? 23-Sep-20 06:30 PM yeah 23-Sep-20 06:30 PM yeah - I believe it was @idmb who gave me the idea 23-Sep-20 06:30 PM although admittedly I haven't been working on the QKD stuff for a bit 23-Sep-20 06:31 PM yeah no worries though, you got alot done. I haven't had a chance to check in a while myself either 23-Sep-20 06:31 PM I have yet to do the HV supply measurements and stuff like that 23-Sep-20 06:32 PM Was doing a little Mathematica stuff, also working on gwpy...trying to analyse the latest collison data 23-Sep-20 06:32 PM collision data? 23-Sep-20 06:32 PM From the latest black hole collison 23-Sep-20 06:32 PM oh 23-Sep-20 06:32 PM the strain data is open source 23-Sep-20 06:32 PM but really noisy 23-Sep-20 06:33 PM I haven't even been keeping up with that sort of thing lol 23-Sep-20 06:33 PM two very heavy black holes collided...created an intermediate mass black hole about 150 solar masses 23-Sep-20 06:33 PM I see 23-Sep-20 06:33 PM released about 8 solar masses in gravitational wave radiation 23-Sep-20 06:34 PM I am going to admit - those look like words and numbers to me 23-Sep-20 06:34 PM what makes it significant to you? 23-Sep-20 06:35 PM these collisions release more energy than all the stars in the entire universe over a fraction of a second... 23-Sep-20 06:35 PM but because space-time is so "stiff" the vibrations are really tiny by the time it gets to the detectors 23-Sep-20 06:35 PM The way they collide can give hints to quantum gravity 23-Sep-20 06:36 PM right. 23-Sep-20 06:36 PM I sometimes forget that that's exactly what you're working to research and understand 23-Sep-20 06:38 PM hahaha yeah, that's my main area. 23-Sep-20 06:39 PM On my end I need to clear my workbench 23-Sep-20 06:39 PM and set things up for measuring the HV modules 23-Sep-20 06:39 PM cool cool 23-Sep-20 06:40 PM the HPDs are something I don't exactly want to damage 23-Sep-20 06:40 PM https://www.youtube.com/watch?v=vB-Y_el4xxg 23-Sep-20 06:41 PM remind me to get the measurements done haha 23-Sep-20 06:41 PM haha I'll try 23-Sep-20 06:42 PM Isaac's having some tests and all now I think, so next week I might clear the bench and start taking some measurements 23-Sep-20 06:42 PM also need to design the bias supply for the avalanche photodector part of the HPD 23-Sep-20 06:43 PM I'm so glad you know the electronics end of this...that's way out of my area 23-Sep-20 06:43 PM and I am glad I have someone to refer to for the physics end of it 23-Sep-20 06:43 PM We make a pretty good team 23-Sep-20 06:43 PM we'll see XD 23-Sep-20 06:43 PM but anyway, I am still debating 23-Sep-20 06:43 PM geiger mode or linear mode for the APD 23-Sep-20 06:43 PM dark counts are still a problem 23-Sep-20 06:43 PM and some of the literature I've read talks about linear mode biasing of APDs 23-Sep-20 06:43 PM I just wonder how it will work in a HPD, where there's a photocathode right in front of a APD 23-Sep-20 06:46 PM That what you'll be using to measure polarization? 23-Sep-20 06:46 PM or rather the presence of a photon? 23-Sep-20 06:46 PM I mean the measurement itself is done by the polarizer 23-Sep-20 06:47 PM will be interesting to see what the dark counts are actually 23-Sep-20 06:47 PM kind of curious 23-Sep-20 06:48 PM I need to work on the amplifier and MCU for that 23-Sep-20 06:49 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200923_103659-DE781.jpg 23-Sep-20 06:49 PM Bunny! 23-Sep-20 06:49 PM lol 23-Sep-20 06:49 PM I think that would be better in #off-topic-thats-sometimes-on-topic 23-Sep-20 06:49 PM Skye's right here beside me looking furry and cute 23-Sep-20 06:49 PM hahah she will not be constrained 23-Sep-20 06:49 PM she's also my grad student 23-Sep-20 06:50 PM right. 23-Sep-20 06:50 PM right now I am just getting a server decomissioned and cleaned up for sale later 23-Sep-20 06:50 PM just a whole lot of waiting 23-Sep-20 06:50 PM cause doing the disk wipe 23-Sep-20 06:56 PM yeah that's always a long proccess 23-Sep-20 06:56 PM haha I should buy it off you...but the shipping would kill me lol 23-Sep-20 06:57 PM if you hop on over to the hangout, I'd discuss an easier option lol 23-Sep-20 06:58 PM what hangout? 23-Sep-20 06:58 PM aka my discord server where the few of us chat? lol 23-Sep-20 06:59 PM ah ok...lol 23-Sep-20 06:59 PM I thought that might be a channel name or something sheesh...so many places. Your beak is popping up everywhere 23-Sep-20 07:00 PM @cenobyte so, which experimentalists are you hounding for super precise measurements to test your preferred quantum gravity? 23-Sep-20 07:00 PM lol haven't been really hounding anyone specific...I've got a couple experimental ideas though 23-Sep-20 07:00 PM Cenobyte: I mean the server itself is called the BitOwl's Hangout 23-Sep-20 07:00 PM it's right there in the name 23-Sep-20 07:01 PM I'm already on there 23-Sep-20 07:01 PM I'm just saying - go there, and we can discuss servers, in fact I already pinged you 23-Sep-20 07:01 PM servers are quite offtopic here 23-Sep-20 07:17 PM Also @cenobyte are you west coast and do you want a vacuum chamber? 23-Sep-20 07:24 PM https://www.youtube.com/watch?v=5lM9ShSoJvU&feature=youtu.be 23-Sep-20 07:24 PM the ultimate in "they don't pay me enough to care about my job" 23-Sep-20 07:38 PM I mean there's stuff like this too 23-Sep-20 07:38 PM https://www.youtube.com/watch?v=Aq_jkUVgrc0 23-Sep-20 07:38 PM and a whole lot more stories 23-Sep-20 07:48 PM Also Cenobyte are you west coast and do you want a vacuum chamber? that the plasma one? 23-Sep-20 08:50 PM no 23-Sep-20 08:50 PM just some generic stuff 23-Sep-20 09:32 PM Ah 24-Sep-20 05:47 AM arrrrgh 24-Sep-20 05:47 AM dammit 24-Sep-20 05:47 AM I was trying to measure the output of the HV module 24-Sep-20 05:47 AM guess what? 24-Sep-20 05:47 AM I killed my lab bench power supply with it 24-Sep-20 05:47 AM I did measure it to be about 4+ kV though 24-Sep-20 05:47 AM @cenobyte I failed you 24-Sep-20 05:47 AM ughhh 24-Sep-20 05:51 AM ono 24-Sep-20 05:51 AM @iz wanna take a look at this lab power supply with me? 24-Sep-20 05:51 AM should be fixable 24-Sep-20 05:51 AM you know what I am glad I didn't kill? 24-Sep-20 05:51 AM 500 MHz scope 24-Sep-20 05:51 AM that would be a total bummer if I did 24-Sep-20 05:51 AM note to self: get disposable oscilloscope 24-Sep-20 05:51 AM both power supply channels got damaged 24-Sep-20 05:51 AM the question now is how 24-Sep-20 05:51 AM what I was doing 24-Sep-20 05:51 AM was that I was holding an insulated plier 24-Sep-20 05:51 AM and I went pretty close to the output terminal of the module 24-Sep-20 05:51 AM but I wonder what happened to kill the lab power supply 24-Sep-20 05:51 AM I've never killed any power supply or T&M equipment by accident before 24-Sep-20 05:51 AM so this is it: first blood 24-Sep-20 06:16 AM did it arc back or what? 24-Sep-20 06:17 AM that's what I wanna know 24-Sep-20 06:18 AM well dang 24-Sep-20 06:18 AM at dc you can have some severe induced charges, but not at 4 kV usually 24-Sep-20 06:21 AM wanna see inside? 24-Sep-20 06:21 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200924_212228-A6A71.jpg 24-Sep-20 06:21 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200924_212456-5CDA6.jpg 24-Sep-20 06:21 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200924_212627-51EB8.jpg 24-Sep-20 06:21 AM and of course - big fat heatsink and transformer 24-Sep-20 06:21 AM so I managed to find a block diagram of sorts 24-Sep-20 06:21 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-D2F85.png 24-Sep-20 06:50 AM ooooh 24-Sep-20 06:50 AM so I am measuring the input of a 7815 regulator 24-Sep-20 06:50 AM guess what we see? 24-Sep-20 06:50 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200924_214644-35DEB.jpg 24-Sep-20 06:50 AM this is on the slave supply side 24-Sep-20 06:50 AM and on the primary supply side 24-Sep-20 06:50 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200924_215027-1C1C5.jpg 24-Sep-20 11:26 AM @SleepyOwl Joyce @cenobyte pong... Sorry ping time was bad today... 24-Sep-20 11:26 AM Nice to meet you cenobyte, yea I like semiconductor stuff and been digging into FPGA design and playing with RiscV stuff. 24-Sep-20 11:32 AM @cenobyte get an active differential probe 24-Sep-20 11:32 AM it will serve as a scope condom and improve your experience with the scope too 24-Sep-20 11:32 AM no more shorting mains through ground clip 24-Sep-20 11:33 AM You mean me? 24-Sep-20 11:33 AM oh yes 24-Sep-20 11:33 AM well everyone 24-Sep-20 11:33 AM they're great 24-Sep-20 11:33 AM But it's not mains we're shorting 24-Sep-20 11:33 AM the point is you will blow up the probe before you blow up your scope 24-Sep-20 11:33 AM you can also add some strings of zeners to not blow up either! 24-Sep-20 11:34 AM It's a 12 VDC to (supposedly) 7 kV HV module 24-Sep-20 11:34 AM I was using a HV passive probe, scope is fine 24-Sep-20 11:34 AM But my lab PSU that was powering the thing isn't 24-Sep-20 11:36 AM I have never blown up a scope before and I don't have diff probes like that ? 24-Sep-20 11:36 AM I have never blown up a scope before either 24-Sep-20 11:36 AM I've measured hundreds of volts and hundreds of millivolts 24-Sep-20 11:36 AM Although I might get a disposable Hitachi CRT scope from some local supplier for cheap 24-Sep-20 11:37 AM Just like, don't throw your scope probes haphazardly into some running hv supply or something and you should be fine 24-Sep-20 11:37 AM Yeah 24-Sep-20 11:37 AM Although what killed the lab PSU is an interesting question 24-Sep-20 11:37 AM Or how, rather 24-Sep-20 11:37 AM I am thinking that something must have fed back into the supply and killed something 24-Sep-20 11:37 AM Fun fact - slave output is completely dead 24-Sep-20 11:37 AM Master output however 24-Sep-20 11:37 AM Pegged to 40v 24-Sep-20 11:37 AM Even when all knobs are turned down 24-Sep-20 11:37 AM I'll investigate this later or so 24-Sep-20 11:37 AM Right now I am just being a LazyOwl 24-Sep-20 11:37 AM And laying down doing nothing 24-Sep-20 12:12 PM Sounds like that PSU has a NPN emitter follower output that experienced avalance breakdown. I think a diode like behavior between Collector and Emitter at Ib=0 or a short circuit is to be expected if such a breakdown occured. I have repaired a Lab PSU by replacing such a NPN output transistor. The ouput was always 0 volts after the swap, as the circuitry at the swapped transistor failed as well. I suspect that some inductor somehow released it's energy into the PSU's output, driving it negative 24-Sep-20 12:19 PM People with high voltage pulses: how easily can you pulse ~5kV with a duration under 200ns? 24-Sep-20 12:19 PM With either stuff scavenged from the depths of ebay / where you guys find stuff cheaply, or DIY? 24-Sep-20 12:19 PM Just curious about what kind of short pulse electron gun is feasible for a hobbyist. 24-Sep-20 12:20 PM that is definitely @Applied_Ion stuff 24-Sep-20 12:21 PM I've been summoned 24-Sep-20 12:21 PM Lol what's up? It's been a while here 24-Sep-20 12:22 PM Woohoo he's back 24-Sep-20 12:22 PM 5kV at any length is super trivial 24-Sep-20 12:22 PM Like the gun I was designing was rated to 300kV at 20-30ns 24-Sep-20 12:22 PM It depends on your end goal though 24-Sep-20 12:22 PM Shorter pulses are simple. You can literally just charge a coaxial cable line and fire via spark gap to drive an electron gun 24-Sep-20 12:22 PM Actually at work I literally built a cable pulser to drive our test injector. 30kV at around maybe 10ns. Dirt simple. HV supply, blumlein cable into the gun, spark gap switch. Done. 24-Sep-20 12:22 PM Since the gun was 50 ohms, I used 4 short pieces of RG213, 2 parallel for each leg, connected right to the gun. Since Blumleins pulse negative by default, it's ideal for an e-gun. 24-Sep-20 12:22 PM That's for a self firing gun. If you want control, you will either need a triggered gap, thyratron, or thyristor 24-Sep-20 12:22 PM Also, what type of gun? There are different types, some much easier than others to build 24-Sep-20 12:22 PM You might actually want to watch out over the next few days. I'm literally gearing up for a test soon for a micro-pulsed e-gun as an experimental neutralizer for an experimental ion thruster I will be tackling 24-Sep-20 12:22 PM Haven't revealed the details yet, but it's coming 24-Sep-20 12:22 PM Probably start working on the build tonight 24-Sep-20 12:29 PM Just want someone to build a simple Time-of-Flight thing with an e-gun and MCP because I don't see any DIY ones 24-Sep-20 12:29 PM and they're so simple 24-Sep-20 12:31 PM It's absolutely do-able for hobbyists. I would have already built my monster one, but there were serious safety issues with radiation lol. So I'm downsizing to a super tiny one for thruster stuff 24-Sep-20 12:31 PM Driving an e-gun pulsed is probably the easy part. It's harder to build the gun and do the instrumentation lol 24-Sep-20 12:33 PM you mean in terms of actually focusing the gun properly ? 24-Sep-20 12:33 PM like building one that both has high energy electrons & has enough of them 24-Sep-20 12:33 PM all in the one spot you want them 24-Sep-20 12:33 PM For my applications focusing isn't needed. The high power one us so intense its self focusing. For thrusters you just need to spray electrons lol 24-Sep-20 12:34 PM Oh, electron guns self focus at high powers too? 24-Sep-20 12:34 PM Neat 24-Sep-20 12:34 PM When you are talking about relativistic beams at kAs lol 24-Sep-20 12:35 PM I'm assuming it is nothing at all like the Kerr effect though, right? 24-Sep-20 12:38 PM for ToF you'd probably want variable energy 24-Sep-20 12:53 PM Sorry meeting lol 24-Sep-20 12:53 PM Not like Kerr effect, literally self induced magnetic fields confining the beam. Or in the case of neutral gas transport or dielectric wall transport, reverse currents induced from boundary plasma 24-Sep-20 12:53 PM For the gun, variable energy is simply a factor of adjusting the drive voltage 24-Sep-20 12:53 PM Energy spread however can be very variable depending on the type of source 24-Sep-20 01:00 PM if you vary the energy don't you lose the ability to self focus at certain energies, and then you need to have designed a focusing scheme? 24-Sep-20 01:09 PM Focusing isn't an issue for these types of systems when you are talking about massive beams. My design could accommodate up to 8cm diameter beams, and that's still pretty small for this style lol. Travel is also extremely short, on the order of cm usually. If you want to transport these beams, you cant use regular magnetic optics like typical accelerators, and electrostatics are useless. It's really about the current though. The drive voltage can vary from like 100kV to MVs, but still huge currents cause self focusing. 24-Sep-20 01:09 PM This isn't a normal type of gun you see in like SEMs lol. 24-Sep-20 01:09 PM However, for standard guns, yeah you will need to factor in focusing optics 24-Sep-20 01:09 PM I'm assuming you are going more for a typical type of e-gun for your application 24-Sep-20 01:09 PM If you wanted to do a basic thermionic pulsed gun, you could do a simple tungsten filament, drive it with DC for heating, then use ferrite chokes to protect the DC supply when driving with the HV pulse. Then design your extractor and optics as needed 24-Sep-20 01:25 PM Kind of figured, that makes sense albeit it's not immediately obvious to me that the effect would be focusing without actually solving for it. And the idea behind the e-beam is that it's probably the easiest ionization source for a ToF so you can do ToF things 24-Sep-20 01:25 PM So probably more like a beam you'd see in a surface lab 24-Sep-20 01:26 PM If you are doing ToF on like a gas you could just use a thermionic filament 24-Sep-20 01:26 PM True, that's how our quadrupole does it 24-Sep-20 01:26 PM Though I think the idea was also that you could use an e beam to sublimate, I dunno, cesium and do cesium studies 24-Sep-20 01:26 PM But expand it from just pure gas phase 24-Sep-20 01:26 PM Without having to get a big ass YAG 24-Sep-20 01:26 PM Wait 24-Sep-20 01:26 PM I just said a banned word and it didn't delete 24-Sep-20 01:26 PM Huh 24-Sep-20 01:30 PM You probably wouldn't use an e-beam for Cesium, it's easy enough to ionize on its own it would be done as a Cesium ion beam source 24-Sep-20 01:30 PM Old Cesium thrusters just used contact ionization for Cesium, though it's a nasty substance to work with 24-Sep-20 01:38 PM Actually on the topic of ion sources, with the neutralizer I'm testing I will be working on an extremely versatile ion source for a new thruster build that may be of interest here. No e-beam ionization, no lasers, no gas, far simpler and a very old technology. I'll have more details as I go, I'm hoping to get initial CAD designs up and posted in a couple of weeks. 24-Sep-20 04:01 PM Sounds like that PSU has a NPN emitter follower output that experienced avalance breakdown. I think a diode like behavior between Collector and Emitter at Ib=0 or a short circuit is to be expected if such a breakdown occured. I have repaired a Lab PSU by replacing such a NPN output transistor. The ouput was always 0 volts after the swap, as the circuitry at the swapped transistor failed as well. > I suspect that some inductor somehow released it's energy into the PSU's output, driving it negative Very possible, I will be focusing my attention on the output circuitry stage; doing some checks in a bit 24-Sep-20 04:01 PM also I wasn't able to find a schematic for this 24-Sep-20 04:01 PM but turns out 24-Sep-20 04:01 PM The Tektronix PS280 uses almost the exact same circuitry as these GPC-3030s 24-Sep-20 04:01 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-09F7A.png 24-Sep-20 04:01 PM I won't be surprised if I killed these 2N3055s 24-Sep-20 04:14 PM I filed a claim with fedex, if they fail to buy a replacement flange, I'll take them to court. This is going to be fun. 24-Sep-20 04:16 PM why would they buy a replacement rather than just fund what you paid? 24-Sep-20 04:16 PM doesn't it just go to whatever the insurance on the package was? 24-Sep-20 04:17 PM I mean to say, if FedEx refuses my claim I will take them to court and force them to pay for a replacement. I've never done that before so it will be fun I think, to see their lawyer try to argue it was delivered despite the video clearly showing it was not. 24-Sep-20 04:31 PM doesn't it just go to whatever the insurance on the package was? @idmb they will argue that of course, at most they owe $100 or something, but, in the eyes of a judge that may not be seen as justice. But they may just cave and pay with a demand letter only, I dunno, this is all new to me. 24-Sep-20 04:33 PM I mean to say, if FedEx refuses my claim I will take them to court and force them to pay for a replacement. I've never done that before so it will be fun I think, to see their lawyer try to argue it was delivered despite the video clearly showing it was not. something tells me they just wouldn't show 24-Sep-20 04:33 PM me too, in which case I win by default and can stick a collections agency on them 24-Sep-20 04:34 PM sounds exhausting 24-Sep-20 04:35 PM Oh it's totally not worth it monetarily but I have never sued a large corporation before and want to go through the experience 24-Sep-20 04:36 PM litigation for litigation's sake 24-Sep-20 04:36 PM how much "screw you" money do you have? 24-Sep-20 04:36 PM making things exhausting for the plebs is how c-suite guys get away with negligence and evil, but we can fight this evil with expensive litigation! 24-Sep-20 04:36 PM "screw you" time 24-Sep-20 04:38 PM more money than time, but I am going to ice all my contract projects soon to work on power conversion technologies instead, california is banning IC engines so it's the only rational thing to do 24-Sep-20 04:38 PM the oil and automotive investments in power electronics are going to make the internet bubble look like pocket change, now 24-Sep-20 04:38 PM https://www.gov.ca.gov/wp-content/uploads/2020/09/9.23.20-EO-N-79-20-text.pdf 24-Sep-20 04:54 PM Joined the server. 24-Sep-20 05:44 PM cool! 24-Sep-20 05:44 PM all 5x 2N3055s are shot 24-Sep-20 05:44 PM I wonder how much it will damage my wallet to get 5 replacements 24-Sep-20 05:44 PM I don't think it'll be too much 24-Sep-20 05:44 PM @Foxx so yeah - bummer! But I think I can fix this alright 24-Sep-20 06:44 PM Silicon is still pretty cheap. 24-Sep-20 06:45 PM It should be pretty alright - although sellers here tend to have a knack for charging quite a fair bit on power transistors and stuff 24-Sep-20 06:45 PM but I don't wanna wait for a RS or Digikey order 24-Sep-20 06:45 PM (also - this makes me go out of the house so there's a plus) 25-Sep-20 02:57 AM @SleepyOwl Joyce power transistors are not cheap at all! Don't even try to buy some chinese knock-off, those are usually really terible. Also be aware of counterfeits from some low-trust sellers. I would not definitely buy those from ebay.... http://rayer.g6.cz/elektro/psu4pc/2n3055.jpg here is small dissection done by my friend - you can see original RCA, some noname, probably not-counterfeit from ST and eastern-block produced one... 25-Sep-20 02:57 AM And this dissection was done by me - http://rayer.g6.cz/elektro/psu4pc/2n3055c.jpg on the left, original ST, on the right counterfeit one... 25-Sep-20 04:12 AM @bkralik cool! I am still on the move so I will read them later, but yeah, I am aware of counterfeits and stuff like that 25-Sep-20 05:34 AM Ngl 25-Sep-20 05:34 AM You're making me tempted to go back to the store 25-Sep-20 05:34 AM Get one and saw it open 25-Sep-20 05:34 AM And also to get one from RS or digikey 25-Sep-20 05:34 AM And saw that open too 25-Sep-20 06:43 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200925_214037-7BC81.jpg 25-Sep-20 06:43 AM got a bunch of parts from a supposedly reputable local stockist 25-Sep-20 06:43 AM I'll do the fixing later 25-Sep-20 06:43 AM is just tired from all the walking about and stuff 25-Sep-20 06:50 AM This is an issue if you buy on eBay or AliExpress type places. Unfortunately quite common. If you stick to real brick and mortar distributors such as farnell or element 14 digikey, etc you are in good hands. In 35 years I can think of only one time I got truly dodgy semiconductors through a distributor, and boy were those dodgy! Hahahaha. Soviet versions of 7805’s that would cut out at anything over 24 volts. Caused havoc for us. This was in the early 90’s 25-Sep-20 06:51 AM although even brick and motar distributors and stockist do from time to time, get dodgy parts 25-Sep-20 06:51 AM Dave Jones EEVblog has one story to recount about that 25-Sep-20 11:49 AM Sometimes when I order power fets I get fake ones that are better than the originals 25-Sep-20 03:29 PM If I were not in a hurry to fix this supply 25-Sep-20 03:29 PM I would just order and pay for parts from Digikey and all 25-Sep-20 03:29 PM just so that I know I am getting exactly what is needed and with the high chance its the real thing 25-Sep-20 03:29 PM I don't wanna take chances with stuff I need for my lab 25-Sep-20 03:29 PM and depend on 25-Sep-20 03:40 PM replaced them transistors 25-Sep-20 03:40 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/186b17c0-58fe-4742-968a-dfb906d93753-13A54.png 25-Sep-20 03:40 PM now on to the next board 25-Sep-20 03:40 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200926_063912-658B8.jpg 25-Sep-20 03:40 PM if it killed those transistors 25-Sep-20 03:40 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-015A9.png 25-Sep-20 03:40 PM then those diodes and caps right at the output terminals are either dead or very suspect 26-Sep-20 01:06 AM whatcha doin 26-Sep-20 10:05 AM so more to this power supply saga 26-Sep-20 10:05 AM so I reassembled stuff and ran some tests 26-Sep-20 10:05 AM Slave supply: 26-Sep-20 10:05 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200927_004723-75F66.jpg 26-Sep-20 10:05 AM 5V, 3A fixed supply 26-Sep-20 10:05 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200927_004839-116FF.jpg 26-Sep-20 10:05 AM as you can see, both of them are now in good condition at least on voltage regulation 26-Sep-20 10:05 AM Master supply still has voltage regulation issues 26-Sep-20 10:05 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20200927_004855-21796.jpg 26-Sep-20 10:05 AM 45 volts even when voltage and current knobs are turned down 26-Sep-20 10:05 AM constant current mode is still not working on all 3 supplies 26-Sep-20 10:05 AM at least though - there's only one board to check now 26-Sep-20 10:05 AM I still say that we're off to a good start 26-Sep-20 10:05 AM I wonder if the parts stores are open tomorrow 26-Sep-20 10:05 AM only one store opens on a Sunday 26-Sep-20 10:05 AM but well if I can figure out what's wrong by the day, I could make a trip 26-Sep-20 10:56 AM @funranium so turns out the table I showed the photo of was exposed because they are adding rubidium to that experiment and need more optics 26-Sep-20 11:13 AM You ALWAYS need more optics. This is the nature of such tables. 26-Sep-20 03:21 PM 45 volts even when voltage and current knobs are turned down @SleepyOwl Joyce ive got a psu that does 92 like that 26-Sep-20 03:21 PM https://sfbay.craigslist.org/eby/ele/d/emeryville-hewlett-packard-power-supply/7203085844.html ill cut you a deal lol 26-Sep-20 03:50 PM Lol 26-Sep-20 03:50 PM I will nurse this supply back to health I swear 26-Sep-20 06:55 PM my brand new 30kv supply takes about five minutes to go below 100V when you change the setpoint to 0V 26-Sep-20 06:55 PM Speaking of which 26-Sep-20 06:55 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/video0-30EB3.mov 26-Sep-20 06:58 PM that's one huge power supply 26-Sep-20 06:58 PM I wouldn't dare horse around that one 26-Sep-20 07:02 PM It’s actually two of them ! 26-Sep-20 07:02 PM In each box. 26-Sep-20 07:02 PM What are you using it for? I don't recall something that's this power hungry in your experiment 26-Sep-20 07:02 PM Ion optics 26-Sep-20 07:02 PM The faster they go the more likely you are to detect them 26-Sep-20 07:02 PM So high voltage + long flight path = better ToF / VMI 26-Sep-20 07:03 PM still - those are some big HV supplies that I wouldn't really like messing around 26-Sep-20 07:03 PM The voltage multipliers likely have quite a lot of capacitors in it that will take a while to discharge without a load 26-Sep-20 07:03 PM A much smaller one will kill you easily, that's the frightening stuff 26-Sep-20 07:04 PM Yeah, no real load but even the cheapest supplies output some decent current... 26-Sep-20 07:04 PM This thing is really well regulated I guess? 26-Sep-20 07:04 PM So the capacitors are likely quite big, smoothing out ripples and such 26-Sep-20 07:04 PM though ngl - I do kinda want to see what's inside 26-Sep-20 07:04 PM in terms of circuits and stuff 26-Sep-20 07:05 PM Yeah 16 bit readout 14 bit control 26-Sep-20 07:05 PM The inside is boring 26-Sep-20 07:05 PM Because the high voltage modules themselves are fairly self contained 26-Sep-20 07:05 PM And bought externally 26-Sep-20 07:05 PM I see 26-Sep-20 07:05 PM I did get a -60 kV glassman voltage multiplier today 26-Sep-20 07:05 PM Rated at 6 mA, was from an X-ray scanner 26-Sep-20 07:05 PM The whole front panel is one PCB though 26-Sep-20 07:05 PM with an arduino + the OLED screen + interlock relays + controls etc 26-Sep-20 07:06 PM Arduino? 26-Sep-20 07:06 PM Huh. 26-Sep-20 07:06 PM Arduino and separate ADC/DAC of course 26-Sep-20 07:06 PM a little glad my work isn't the only folks shipping arduino in production industrial electronics 26-Sep-20 07:08 PM Well as you can see by the splash screen 26-Sep-20 07:08 PM This is not shipping 26-Sep-20 07:08 PM fair 26-Sep-20 07:09 PM That all reminds me, need to finish my air quality monitor 26-Sep-20 07:09 PM 30kV supplies were the same price as 20kV, but there’s no connector better than SHV-20 so RIP 26-Sep-20 07:09 PM The most interesting part of these power supplies looks fairly innocent actually: 26-Sep-20 07:09 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-48FC7.png 26-Sep-20 07:09 PM SHV-20 I assume is rated to 20kV? 26-Sep-20 07:10 PM The PCB design has a jumper to limit it to 20, so only an informed individual can overload them 26-Sep-20 07:10 PM Yes @Addison-110m 26-Sep-20 07:10 PM All the other connectors increase their rating when mated 26-Sep-20 07:10 PM They also don’t make nice bulkheads for them? We had to buy the welding ones 26-Sep-20 07:10 PM Meant for vacuum 26-Sep-20 07:12 PM oh eww 26-Sep-20 07:13 PM The machine shop did a lovely job though 26-Sep-20 07:13 PM So it’s fine 26-Sep-20 07:13 PM I just love the OLED screens, which were made easily replaceable if they die 26-Sep-20 07:15 PM I wish manufacturers would make feedthroughs for GES type high voltage connectors, up to 100 kV: https://www.ges-highvoltage.com/ 26-Sep-20 07:15 PM It could honestly be something with an o-ring seal and that'd still be fine, no need for huge long ceramics when not in UHV 26-Sep-20 07:15 PM And it would require little design changes to their existing bulkhead connectors 26-Sep-20 07:15 PM Just drill a hole and tap a few blind holes for mounting screws to install it 26-Sep-20 07:15 PM Allows you to plug your power supply directly into the vacuum chamber 26-Sep-20 07:20 PM I just wish they made more easily accessible SHV stuff 26-Sep-20 07:20 PM SHV 10 doesn’t make sense though 26-Sep-20 07:20 PM Why does it exist ? 26-Sep-20 07:26 PM Do you mean it doesn't make sense in terms of price? @idmb 26-Sep-20 07:43 PM the connectors do more when mated 26-Sep-20 07:46 PM I don't understand... You might pay more for a mated pair of connectors, but a mated SHV-10 is not going to do 20 kV 26-Sep-20 07:56 PM https://www.radiall.com/products/rf-coaxial-connectors/bayonet-connectors/bnc-ht-mhv.html MHV can do 10kV when mated but only 6kV when not, etc. SHV 5 can do 5/10, while SHV 10 can only do 10/12. The main difference between the two is just safety when unmated 26-Sep-20 07:56 PM but because the internet is a mess of standards / the names are terrible, I can't find the thing that said shv 5 can do 10 -_- 26-Sep-20 08:00 PM I mean the prices are so close that it almost doesn't matter, especially in applications like yours, I'd just pay a bit more to get the higher rated connector rather than risking it 26-Sep-20 08:00 PM but then pay a lot more and get shv-20, is what I meant 26-Sep-20 08:00 PM all shv-10 does is make us need more different cables -_- 27-Sep-20 12:21 PM Joined the server. 27-Sep-20 06:01 PM So Autodesk backtracked 27-Sep-20 06:01 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_2020-09-28-08-44-38-456_com.goo-7C94C.jpg 27-Sep-20 06:02 PM I feel like "backtracked" has a pretty negative connotation 27-Sep-20 06:02 PM autodesk... listened to the feedback from the community and changed their plans! yay 27-Sep-20 06:03 PM But never again! 27-Sep-20 06:03 PM Joyce <3 OSS 27-Sep-20 09:56 PM Has anyone implemented individual collision of particles with gas molecules in geant4? 27-Sep-20 09:56 PM Basically I want to simulate the particles trajectories when extracting them from 10~ mbar pressure into 0.1~ mbar into vacuum 27-Sep-20 11:09 PM Do you really need Geant4 for this? Are there relevant nuclear reactions you want to analyze? 27-Sep-20 11:09 PM If you want to know stopping distance, SRIM is a good choice 27-Sep-20 11:09 PM If you want to analyze differential pumping, then unfortunately there are no very good simulations software for transitional/Knudson flow. Break out the pen and paper and use equations 27-Sep-20 11:09 PM @Dalai Llama I think for ion beam optics, IBSIMU is the best free choice but I have no personal experience with it 27-Sep-20 11:09 PM If you really want Geant4 for whatever reason, look into G4beamline by Muons, Inc. It's just a very nice interface to G4 and should do whatever you want it to 28-Sep-20 12:20 PM ooooh 28-Sep-20 12:20 PM I am doing power supply repair round two 28-Sep-20 12:20 PM guess what I found? 28-Sep-20 12:20 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20200929_032108-8FEC8.jpg 28-Sep-20 12:20 PM a hole has been blown from the bottom of this poor LM741 28-Sep-20 12:44 PM F 28-Sep-20 12:45 PM I changed the op-amp 28-Sep-20 12:45 PM master supply still pegs to 45V 28-Sep-20 12:45 PM this Op-amp is supposed to be the voltage comparator 28-Sep-20 12:45 PM I think I am going to just be changing a few transistors etc 28-Sep-20 12:45 PM I suspect a few things being dead 28-Sep-20 01:35 PM The PSU that I fixed after it's emitter-follower output transistor failed had a few bad resistors. You may want to check for charred resistors and fail-open resistors 28-Sep-20 02:01 PM yeah I already found one out of spec resistor 28-Sep-20 03:31 PM a number of resistors, variable resistors, etc measure bad 28-Sep-20 03:31 PM the only thing I just got fixed was the 5V, 3A supply in terms of current regulation 28-Sep-20 08:44 PM @cenobyte since you're online 28-Sep-20 08:44 PM @idmb asked you about a plasma chamber of sorts 28-Sep-20 08:45 PM it's just a 6 way cross 28-Sep-20 08:45 PM heading to sleep now..lol what's this plasma chamber about? 28-Sep-20 08:45 PM homemade fusion reactor? 28-Sep-20 08:45 PM what I have for free isn't a plasma thing 28-Sep-20 08:45 PM it's just a high vacuum thing 28-Sep-20 08:45 PM Oh lol 28-Sep-20 08:45 PM I mixed it up 28-Sep-20 08:46 PM oh cool though 28-Sep-20 08:46 PM I assume you'd have to get some kind of vacuum pumps to run it 28-Sep-20 08:47 PM and mount it and stuff 28-Sep-20 08:47 PM use a vacuum cleaner, hey it has the term vacuum in it right? 28-Sep-20 08:47 PM hahaha 28-Sep-20 08:47 PM alright heading to sleep 28-Sep-20 08:47 PM night all! 28-Sep-20 08:48 PM Wow 28-Sep-20 08:48 PM You didn't even answer the question 28-Sep-20 08:48 PM which question? 28-Sep-20 08:48 PM I still don't see any question 28-Sep-20 08:48 PM Do you want such a thing? 28-Sep-20 08:49 PM oh...I don't know what I'd do with it..probably cost a fortune to ship 28-Sep-20 08:49 PM Idmb has no use for it I think 28-Sep-20 08:49 PM how big is it? 28-Sep-20 08:49 PM I can hold onto it indefinitely 28-Sep-20 08:49 PM are you west coast canada? 28-Sep-20 08:50 PM @SleepyOwl Joyce maybe our next project 28-Sep-20 08:50 PM @idmb yeah. Alberta 28-Sep-20 08:50 PM calgary or edmonton? 28-Sep-20 08:50 PM edmonton 28-Sep-20 08:50 PM f 28-Sep-20 08:50 PM it's not worth that much thinking about 28-Sep-20 08:51 PM I'm still thinking of ways to measure quantum aspects of the gravitational field lol 28-Sep-20 08:51 PM What physics shenanigans are you thinking of, my crazy physicist friend 28-Sep-20 08:51 PM would need to find a way of putting larger masses into a superposition of location states 28-Sep-20 08:51 PM then measureing the gravitational field of them 28-Sep-20 08:51 PM extremely sensitive measurements....not an easy experiment 28-Sep-20 08:52 PM look up nikesh dattani's work on quantum gravity spectroscopy 28-Sep-20 08:52 PM ah ok will do. thank you 28-Sep-20 08:52 PM night all! 28-Sep-20 08:53 PM pets @cenobyte to sleep 28-Sep-20 08:53 PM Also just saying 28-Sep-20 08:53 PM I have no idea how I could participate in certain projects and experiments with you, for the lack of knowledge, or physical distance haha 28-Sep-20 08:53 PM considers migrating to Canada? 28-Sep-20 08:53 PM Lol. 28-Sep-20 08:58 PM Hi, I'm Ceno, I'm a theoretical physicist 28-Sep-20 09:01 PM I mean sure he is, although he is working with me in certain experiments like the QKD thing I am supposed to be working on 28-Sep-20 09:01 PM On the theoretical physics side, I have a lot, a lot to catch up and read and understand 29-Sep-20 02:47 PM Joined the server. 30-Sep-20 02:54 PM Huh. So there was this project: https://hackaday.io/project/21831-3d-printed-scanning-electron-microscope 30-Sep-20 02:54 PM I'm having a hard time finding the owner's manual for the MKS QL6513 rf generator 30-Sep-20 02:54 PM anyone have friends at MKS? 30-Sep-20 03:12 PM MKS was pretty responsive when I asked questions about a few ebay sensors 30-Sep-20 03:14 PM I got a call from them saying they'd email the manual but it never happened. 30-Sep-20 03:25 PM MKS is terrible to deal with in my experience 01-Oct-20 11:13 AM Joined the server. 01-Oct-20 05:21 PM suddenly it makes a lot of sense why the last 10 minutes of cooling my nozzle go very quickly 01-Oct-20 05:21 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Variation-of-thermal-conductivities-of-cop-BB267.png 01-Oct-20 06:08 PM that curve is really strange... but your nozzle is 50 kelvin? 01-Oct-20 06:09 PM 10k 01-Oct-20 06:09 PM Also MKS finally got back to me with a manual, here it is if anyone also needs it. 01-Oct-20 06:09 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/ENI_SurePower_QL10513_9282-001-4FE7D.pdf 02-Oct-20 12:38 PM My power cable for my pump just decided to explode? I don't think anything bad happened on the pump side, just the cord let the smoke out? I'm really not sure 02-Oct-20 12:46 PM Was it wired appropriately?... 02-Oct-20 12:52 PM Yes, I don't know what could've cause it, it's a standard C13 to 5-15P cable. 02-Oct-20 12:52 PM The switch from 120 to 240 is on the correct setting and cannot be changed without removing a cover so its not like I hit that since the last time I used it. 02-Oct-20 12:56 PM this is your RV3? 02-Oct-20 12:56 PM Yeah 02-Oct-20 12:56 PM Switched out with another generic 14 AWG cable... running fine 02-Oct-20 12:56 PM Just trying to figure out what would've caused that cable to blow 05-Oct-20 06:04 AM Hi there, anyone would have some pins mapping to start this little turbo ? I have a 0-120DC I guess this one is 94V, but no clue of how to start it. My pilot card seems KO 05-Oct-20 06:04 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-C8CF4.jpg 05-Oct-20 06:59 AM I think there's a good chance this pump has the same pinout as the 5011 drag pump: http://www.wimmeralogic.com/adixen-alcatel/MDP-5011.html 05-Oct-20 06:59 AM You can verify this by measuring the motor winding resistances and checking the thermistor resistances easily 05-Oct-20 02:42 PM decided to follow the steps to tune my PID today 05-Oct-20 02:42 PM so fun making the changes and watching the response curve perfectly match what the instructions say it will do lol 07-Oct-20 01:14 PM How useful is a 3-axis plus rotation vacuum manipulator? One of my neighbors is selling one and I'm tempted 07-Oct-20 01:15 PM flange size? travel? 07-Oct-20 01:15 PM we have a 2.75" XYZ + rotation UHV manipulator with like 18" of Z travel. It has gone unused for the past decade because it's too fancy to justify for most of our applications 07-Oct-20 01:16 PM Yeah that seems like something that could be extremely useful or extremely not useful depending on your exact project and needs 07-Oct-20 01:16 PM Think the real questions are how cheap and how much storage space does it eat 07-Oct-20 01:22 PM 6" CF, I think it's a few inches of travel in every direction. He wants 5 benjamins for it. 07-Oct-20 01:25 PM Manual control? 07-Oct-20 01:25 PM Position readouts? 07-Oct-20 01:25 PM Yeah I think so 07-Oct-20 01:25 PM Unsure about position 07-Oct-20 01:25 PM some are manual control but with nice micrometers, some have nice digital readouts 07-Oct-20 01:26 PM This is way too old to be digital lol 07-Oct-20 01:26 PM Hmm. $500 is a good price, but I still don't get what you want to use your vacuum system for... 07-Oct-20 01:26 PM Neither do I 07-Oct-20 01:26 PM I like to collect capability so I'm ready for new opportunities 07-Oct-20 01:26 PM How bulky is it? 07-Oct-20 01:27 PM I think it'll be about the size of a small refrigerator when I'm done 07-Oct-20 01:27 PM I meant the manipulator 07-Oct-20 01:27 PM $500 just for a decent CF6 bellows is not bad, if the manipulator is the type where that can be removed if you want to ? 07-Oct-20 01:27 PM Oh, less than 250mm^3 07-Oct-20 01:29 PM Ah, it's probably only a couple mm x/y travel 07-Oct-20 01:29 PM I'll check, if that's the case I'm not super interested but he said it was more than that 07-Oct-20 01:29 PM If it has fine adjustment that's still very useful though 07-Oct-20 01:29 PM He's also selling an entire vapor deposition system 07-Oct-20 01:29 PM Just depends on the application 07-Oct-20 01:44 PM I am a total cheapskate so unless that was around $100 or I had a pressing need for it...I would probably pass 07-Oct-20 01:44 PM Thats the only reason I have a cryohead and compressor...guy was willing to let it go for $100 with the helium lines and everything. For that price I can give up some shelf space 07-Oct-20 04:26 PM @adammunich where's your friend at and how much does he want for thr vapor dep? And do you not want it first? 07-Oct-20 04:26 PM Manual controls are a lot more useful for some applications 07-Oct-20 04:26 PM My part time job has all manual controls available (i think it also has x y z digitally available) but the main guy does majority of the detail work manually 07-Oct-20 04:27 PM He's in Berkeley and he's not ready to sell the part off itself, he wants to sell all his vacuum stuff at once. 07-Oct-20 04:27 PM Basically using his FIB like a milling machine 07-Oct-20 04:28 PM I think he'll eventually realize that's not gonna happen and start selling the stuff off individually though. 07-Oct-20 04:28 PM The decision to liquidate is a new one that I'm not sure he's entirely excited about, but was forced to for heath reasons. 07-Oct-20 04:28 PM I already have two really fabulous chambers in the works so I myself am not particularly in need of a third. 07-Oct-20 04:30 PM Well I'd be interested, it's *only" a 10 hour drive from Portland 07-Oct-20 04:32 PM What's your budget? I can tell him next time I see him. I think it would make him happy to see someone use the thing for its purpose and not just part it out. 07-Oct-20 04:32 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20201005_154550-4DF8E.jpg 07-Oct-20 04:32 PM Rack full of stuff included, power supplies, pump drivers, vac guages, thickness guages etc 07-Oct-20 04:36 PM the frame + turbo + middle chamber is quite nice 07-Oct-20 04:36 PM leak valve too 07-Oct-20 04:40 PM Yeah it's got pretty much everything you need for coating 12" optics, unfortunately the man is now almost blind so he has no more need for optics. 07-Oct-20 04:40 PM If he wants to sell the whole lot no matter what, I would be tempted to share some of the cost if I can keep some of the parts for myself. There are an assortment of un-mounted feed throughs, roughing pumps and flanges I may be able to put to good use. I just can't see myself needing the chamber or rack stuff at all. 07-Oct-20 04:45 PM I mean what ballpark do you think he's looking for? 07-Oct-20 04:46 PM Hmm, my budget is hard to say... I don't have a burning need for more projects as much as I have a need for more time 07-Oct-20 04:46 PM I mean what ballpark do you think he's looking for? @idmb $5000 for it all which I think is pretty fair. There are lots of additional parts which individually would be worth more at eBay prices. This person seems to have had good clean room practices too, that laminar flow fume hood is included in the lot. 07-Oct-20 05:31 PM Ooo I didn't even notice that 07-Oct-20 05:31 PM So this has high vac and what sort of deposition ? 07-Oct-20 05:31 PM Thermal evap, sputter, e-beam, cvd ? 07-Oct-20 08:22 PM @nmz787 thermal evaporation I think 07-Oct-20 08:22 PM But it could become anything else easily since there are so many CF ports 08-Oct-20 12:04 AM Wish me luck cleaning the flour out of this little pump 08-Oct-20 12:04 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20201008_000356-DB51D.jpg 08-Oct-20 12:04 AM Should I just stick with ethanol? 08-Oct-20 12:05 AM I always use break cleaner, gets rid of the oil well but at least my brand doesn't harm the gaskets 08-Oct-20 12:05 AM also scotch brite pads, but not steel wool 08-Oct-20 12:05 AM the main question is 08-Oct-20 12:05 AM how did you get flour in this pump 08-Oct-20 12:39 AM I was using a food saver vacuum adapter on some canning jars filled with flour that we transferred from the paper bag the bulk store sold it to us in, so insects or rodents didn't get to it 08-Oct-20 12:40 AM oh no 08-Oct-20 12:45 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/PXL_20201008_074203676-FE749.jpg 08-Oct-20 12:46 AM aaaaa 08-Oct-20 12:46 AM Rubber hose was always cracking and had black"dandruff" 08-Oct-20 12:46 AM It was basically welded on to this input stem 08-Oct-20 01:12 AM This amount of sludge is normal, right? 08-Oct-20 01:12 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/PXL_20201008_081054690-898BE.jpg 08-Oct-20 01:12 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/PXL_20201008_081155997.NIGHT-2BE5C.jpg 08-Oct-20 01:31 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/PXL_20201008_081514636-58C05.jpg 08-Oct-20 02:34 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/PXL_20201008_093410277-9E449.jpg 08-Oct-20 02:34 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/PXL_20201008_093422677-357C4.jpg 08-Oct-20 02:53 AM yikes 08-Oct-20 02:58 AM Trying to ship silicon wafers now 08-Oct-20 02:58 AM They insist on a phone number for the recipient :/ 08-Oct-20 02:58 AM How long do I need to wait before I get the phone number since the person isn't online now :/ 08-Oct-20 03:01 AM oh alsi I just now realized thatthis isn't a rotary vane pump 08-Oct-20 03:14 AM Sigh why do they insist on a phone number 08-Oct-20 03:14 AM I'll just wait until they close in about 90 mins 08-Oct-20 03:15 AM I guess their service is to contact the recipient if something is wrong 08-Oct-20 03:15 AM Perhaps 08-Oct-20 03:15 AM I dunno how long I need to wait before I get the number 08-Oct-20 03:15 AM Then maybe I have to cancel the shipment once closing time approaches 08-Oct-20 03:15 AM And then they're going to have to wait until I can be bothered to come back to the shipping center 08-Oct-20 03:15 AM Or is there some German number service I can use? 08-Oct-20 03:19 AM none that I know of 08-Oct-20 03:19 AM Like a temporary number 08-Oct-20 03:20 AM I have a permanent german number so I don't need to look for a temp service 08-Oct-20 03:21 AM Basically I don't wanna risk waiting for the recipient to only come online after like two hours or so 08-Oct-20 03:21 AM Then I have to cancel the shipment 08-Oct-20 03:21 AM And then I have no idea when I will pass by here next 08-Oct-20 03:22 AM if you give them your number they can call you in case of some issues and by then you'll probably have the recipients number? 08-Oct-20 03:23 AM Maybe 08-Oct-20 03:34 AM Got a temp number 08-Oct-20 03:34 AM Darn this lol 08-Oct-20 03:47 AM Done 08-Oct-20 03:47 AM Fill a temp number first lol 08-Oct-20 04:54 AM What is a temp number? 08-Oct-20 04:54 AM Personally I think I would have just given my number for both 08-Oct-20 04:55 AM basically a number that expires after a certain time 08-Oct-20 04:55 AM Or like my moms for sender and mine for recipient 08-Oct-20 04:55 AM @GigaSquirrel what kind of pump is this then? 08-Oct-20 04:55 AM One of the cog/gear things is lodged into the gear/cog housing 08-Oct-20 04:55 AM I have it sitting in n methyl pyrrolidone now 08-Oct-20 04:55 AM Hoping it dissolves the flour paste 08-Oct-20 04:55 AM I am not super hopeful tho 08-Oct-20 04:55 AM My next idea is to try an oxygen plasma asher 08-Oct-20 04:55 AM Or possibly just heating it with a torch? Or in oven? 08-Oct-20 04:55 AM Cook the flour so it gets crunchy? 08-Oct-20 04:55 AM I also put it into a sonicator for like 8 minutes in an ethanol bath (and maybe there was some acetone but probably not much if any) 08-Oct-20 05:06 AM https://www.idealvac.com/NEW-Welch-8890A/pp/P104262 08-Oct-20 05:06 AM Says it's a rotary vane 08-Oct-20 05:06 AM The green highlight 26 is stuck inside the other half of 26 08-Oct-20 05:06 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_20201008-051054-400B3.png 08-Oct-20 05:13 AM I don't know what that type of pump is called, but it doesn't exactly have rotating vanes 08-Oct-20 05:20 AM It's basically the right side of this diagram 08-Oct-20 05:20 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/intro-gear-pumps-fig1-BF532.jpg 08-Oct-20 07:46 AM blech 08-Oct-20 09:41 AM Any suggestions for etching the flour but not the steel? 08-Oct-20 09:50 AM soap and ellbow grease? 08-Oct-20 09:50 AM also break cleaner 08-Oct-20 10:20 AM There's no way to get into the crevice 08-Oct-20 10:20 AM I already got as far as I can with wooden toothpicks 08-Oct-20 10:30 AM @GigaSquirrel do you get the good brake cleaner, or the less effective California style? 08-Oct-20 10:30 AM ( i think the latter lacks chlorine based chems) 08-Oct-20 10:32 AM considering that you want to clean steel I guess you can go as aggressive as you want 08-Oct-20 10:32 AM This is my go to, here in germany 08-Oct-20 10:32 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DV_8_5829162_02_4c_DE_20190415081656-CB463.png 08-Oct-20 11:09 AM I can't read the ingredients 08-Oct-20 11:11 AM only says acetone free 08-Oct-20 11:11 AM msds lists naphta and co2 08-Oct-20 11:11 AM also propane 08-Oct-20 11:11 AM so I guess just benzine? 08-Oct-20 11:24 AM Why not just use acetone? That’s what I use to clean metal when I’m welding and it can’t be dirty. 08-Oct-20 11:26 AM The issue I'm having is the part is seized 08-Oct-20 11:26 AM So unless acetone will actually dissolve the flour, or shrink it.. It's not gonna help much 08-Oct-20 11:28 AM maybe just compressed air will do the trick? 08-Oct-20 11:32 AM Was trying 120 PSI last night 08-Oct-20 11:32 AM Pretty much no effect 08-Oct-20 11:32 AM It's vacuum oil dough at this point 08-Oct-20 11:32 AM Super viscous, and maybe non newtonian 08-Oct-20 11:37 AM How much access do you have to the part that is seized? 08-Oct-20 11:37 AM Guessing not enough to manually clean the flour out :/ 08-Oct-20 11:41 AM add yeast 08-Oct-20 11:41 AM bake it 08-Oct-20 11:41 AM it will expand into fluffy bread 08-Oct-20 11:45 AM I mean baking is good for vacuum stuff, right? 08-Oct-20 11:57 AM @nmz787 soak it in gasoline 08-Oct-20 11:58 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/PXL_20201008_093422677-46676.jpg 08-Oct-20 11:58 AM It's a very effective cleaner and will solubilize your pump oil sludge very well. 08-Oct-20 11:58 AM It's the inner gear on the lower right part 08-Oct-20 11:58 AM I do have gasoline 08-Oct-20 11:59 AM Maybe remove the o ring first 08-Oct-20 11:59 AM Although if it's butyl n it should be fine 08-Oct-20 10:04 PM And be careful of that flat gasket, old gaskets like that can break very easily 09-Oct-20 05:34 AM has anyone used dsmcfoam+? 09-Oct-20 05:34 AM very stupid question: I can't find where I would get the files to connect it to openfoam 09-Oct-20 08:23 PM I've spent so long trying to align little apertures to my beam 09-Oct-20 08:23 PM Adding/removing them changes the signal by way more than the solid angle should change (like 20x vs 4x) and the adjustment is slow / about 90 minutes to check each position 09-Oct-20 11:16 PM power supply troubleshooting - turns out even the front panel pots are kaput 09-Oct-20 11:16 PM sigh 09-Oct-20 11:16 PM I wonder how did that die 09-Oct-20 11:16 PM note - order some high voltage protection diodes? 09-Oct-20 11:16 PM is that sufficient for high voltage kickback though? 10-Oct-20 12:18 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20201010_001747-173CA.jpg 10-Oct-20 12:18 AM What is the reason for this protrusion? It does not rotate as I rotate the larger wheel, as well. 10-Oct-20 12:18 AM Or rather, it counter rotates 10-Oct-20 10:21 AM http://acspubs.co/9mA050BO3r0 Oh wow this is sweet 10-Oct-20 10:21 AM Novel pressure sensor ranging atm to 10^-6 torr 10-Oct-20 11:55 AM That is a really cool paper. Surprisingly simple sensor design. 10-Oct-20 12:21 PM It’s based on chemisorption of gasses so wonder how well I would work for noble gasses? I don’t really know how well they chemisorb if they’re inert? But they may be dumb logic idk 10-Oct-20 12:21 PM But yeah the sensor design is cool. Plus always nice to see graphene applications that actually deliver instead of just being overhyped stuff 10-Oct-20 01:23 PM I like seeing ultrasonication of Graphene stuff.. that's somewhat thee procedure I follow (exfoliation of graphite->graphene in biphasic 'solutions', not [reduced] Graphene Oxide) 10-Oct-20 02:43 PM I was gonna try that actually 10-Oct-20 02:43 PM There is also a way to do it by hitting polyimide sheets with 405nm lasers that makes graphene apparently 10-Oct-20 03:03 PM This one? 10-Oct-20 03:03 PM https://pubs.acs.org/doi/10.1021/acsami.0c01377 11-Oct-20 05:31 PM @nmz787 Have you been able to repair the tip seal on your dry scroll pump? 11-Oct-20 05:31 PM I'm looking at this 3 phase dry scroll pump with very high hours logged on the motor, and I'm wondering if it's worth the risk https://www.ebay.com/itm/Edwards-Model-GVSP-30-Dry-Scroll-Pump-P-N-A710-04-909-18419-Hours-UNTESTED/233723370368 11-Oct-20 05:31 PM The tip seal kit is about $400 for this, I wonder if it can be replaced by Teflon seals I can buy elsewhere 11-Oct-20 05:31 PM Mostly worried that the metal sealing faces might be scratched up and require a lot more polishing 11-Oct-20 05:46 PM IIRC on the triscrolls there's quite a big gap 11-Oct-20 05:46 PM so damage is unlikely there 11-Oct-20 05:47 PM So they are not actually contact seals? Or at least not meant to be? 11-Oct-20 05:47 PM This is what the seal arrangement on this pump looks like 11-Oct-20 05:47 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-58318.png 11-Oct-20 05:47 PM Two pairs of seals on the rotor have this ring at the end 11-Oct-20 05:47 PM So it's unlikely I can get alternative replacement for that, unless I machine my own from a Teflon sheet 11-Oct-20 05:47 PM At that point it might be better to just get the tip seal kit 11-Oct-20 05:47 PM Or do you mean big gap between the metal surfaces? That doesn't matter if abrasive particles got in between the PTFE tip seal and the stator surface 11-Oct-20 06:00 PM Oh I just meant where the tip seals go 11-Oct-20 06:00 PM you're talking about the walls of the spirals? 11-Oct-20 06:01 PM No the bottom of the spirals where the tip seal go against the metal surface 11-Oct-20 06:01 PM The tip thickness is non-negligible 11-Oct-20 06:01 PM not a lot of metal-metal 11-Oct-20 06:02 PM Yeah I don't mean metal-metal, even if you get particles between the tip seal material itself and the metal surface, it will act as a sand paper 11-Oct-20 06:02 PM The tip seal should wear out first but it will scratch the hell out of the metal too 11-Oct-20 06:03 PM the tip seals turn to sawdust well before that in my experience 11-Oct-20 06:03 PM and then you have no pumping and replace it 11-Oct-20 06:03 PM with a bad tip seal they're just loud and do nothing 11-Oct-20 06:05 PM I don't think this pump has actually ran 18500 hours on one set of tip seals, the motor hour counter might not be reset every time they do maintenance on the pump 11-Oct-20 06:06 PM that's not even that many hours 11-Oct-20 06:06 PM that's just two years of continuous use 11-Oct-20 06:06 PM ours last like 2-3 before tip seal replacement, one needed a motor replacement after six years but the others have been fine with continuous use. 11-Oct-20 06:06 PM No harsh chemicals though. 11-Oct-20 06:08 PM Normal replacement schedule for tip seals is 8000 hours 11-Oct-20 06:08 PM And yeah I've no idea what this was pumping 11-Oct-20 06:08 PM ain't nobody got time for that 11-Oct-20 06:08 PM I guess I'm probably both inspiring confidence in the robustness of these pumps and fear about the condition of the one you're looking at lol 11-Oct-20 06:11 PM I mainly want to pump hydrogen/deuterium with this, also would be nice for freeze drying 11-Oct-20 06:11 PM My Leybold D2.5E is also starting to complain lately, overheating after an hour or two and shutting down 11-Oct-20 06:11 PM External fan didn't help that much 11-Oct-20 06:11 PM This guy also sells loads of cheap VFDs, but it looks like they are all 3 ph in 3ph out 11-Oct-20 06:11 PM Oh nevermind, looks like they have a $40 VFD that should work perfectly 11-Oct-20 06:23 PM come pick up an edwards 40 11-Oct-20 06:23 PM Hey you know what I might actually do that during Christmas 11-Oct-20 06:23 PM Road trip to Vancouver and meet some relatives 11-Oct-20 06:23 PM Don't have an outlet that can run that beast, but whatever 11-Oct-20 06:38 PM if you let me know mid-end november 11-Oct-20 06:38 PM I will ask if there's anything like that ready to go 11-Oct-20 06:38 PM Unfortunately the cabinet the one oil pump we do use 11-Oct-20 06:38 PM happens to fit the ones we don't use too 11-Oct-20 11:11 PM @Mason_YuWe have really good experience with Edwards scroll pumps - because of weld failure, one was pumping water for whole night and surprisingly after draining out apparatus and fixing the weld, it works even better now. Just beware of that tip-seals - in some models it is not PTFE sheet itself, it has some "foamy" layer below, probably to increase the PTFE contact pressure. So I would be a bit afraid of cutting it on my own... 11-Oct-20 11:12 PM Considering the weird shape on one of the rotor tip seals, I think it would be just better to bite the bullet and get the $400 kit 11-Oct-20 11:12 PM I will take it apart when it arrives though, just to see the condition of the seals and clean them if necessary 11-Oct-20 11:14 PM Ok! If you will clean the scrolls, do it carefully, some models have that area PTFE coated (using abrasives like schotchbrite is tempting, but definitely not recommended) 11-Oct-20 11:18 PM I guess a lot of it depends on the model, some tip seals look quite strange, like they have additives to the PTFE 11-Oct-20 11:18 PM But most are just a pair of single square strip, which I thought would be easy to DIY 11-Oct-20 11:19 PM This was in Edwards XDS35i... 11-Oct-20 11:26 PM https://patents.google.com/patent/US6068459A/en 11-Oct-20 11:26 PM This describes the need for the foamy padding under the main seal 11-Oct-20 11:26 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-86F8F.png 11-Oct-20 11:28 PM I’ll dig up our guide 11-Oct-20 11:28 PM Looks familiar. You can buy the material and waterjet your own tip seals for cheap 11-Oct-20 11:29 PM So Teflon paste is an option, or some urathane foam as the patent suggests 11-Oct-20 11:29 PM I'm not sure that other types of common o-ring materials are really not feasible, like silicone o-ring stock 11-Oct-20 11:29 PM https://www.mcmaster.com/soft-o-rings/high-temperature-soft-silicone-o-ring-cord-stock/ 11-Oct-20 11:31 PM But overall the process is enough man hours and since getting the iGX600L they’re no longer running 24/7; we went for a full head replacement last failure and will again 11-Oct-20 11:31 PM If another does 11-Oct-20 11:31 PM Our stock is nothing like an o ring 11-Oct-20 11:32 PM Yeah well similar approach at pretty much any company. A $8000 pump is pretty cheap by their standards 11-Oct-20 11:32 PM I’ll check when I’m in next 11-Oct-20 11:32 PM I mean the o-ring is there to provide the compressive force onto the actual square PTFE seal 11-Oct-20 11:32 PM We have all the parts to same day repair 11-Oct-20 11:32 PM Just, wouldn’t bother 11-Oct-20 11:32 PM Whatever our stock is, it’s big sheets of the same stuff the original seals are made of 11-Oct-20 11:32 PM No clue where we got it 11-Oct-20 11:34 PM What does the underside of that stock look like? 11-Oct-20 11:35 PM One side is some semi translucent rubbery plastic thing and the other is like a foamy thing. Haven’t looked closely at it for like 18 months 11-Oct-20 11:36 PM I'll search around for this sheet stock for sure 11-Oct-20 11:36 PM I just know we had a tip seal kit and some homemade ones and I couldn’t tell the difference 11-Oct-20 11:36 PM Maybe said “kit” was a knockoff 11-Oct-20 11:38 PM I mean $400 does sound really high for what it is, but then again this is for a $8000 pump that's only needed every year or two 11-Oct-20 11:39 PM Why so expensive? With academic new pricing, our triscroll 300s were just over $3000 CAD each 11-Oct-20 11:39 PM Head replacement is like half that of course 11-Oct-20 11:39 PM Because, well, that’s the pump 11-Oct-20 11:40 PM Well you'd have to ask Edwards, also the pricing is from like 2006, where dry scroll pumps were less common 11-Oct-20 11:40 PM Also looks like you got a hefty academic discount: https://www.agilent.com/store/en_US/LCat-SubCat2ECS_33437/TriScroll-300 11-Oct-20 11:41 PM Asking prices are made up 11-Oct-20 11:41 PM Academic turbo pricing goes down to like 60% off sometimes 11-Oct-20 11:41 PM ARS told us directly they could write whatever discount we wanted for a custom system if that helped with grants lol 11-Oct-20 11:44 PM Well that's because your school is a huge customer, certainly not everyone will get the same treatment. Although in industry, trying to fix broken things that can be replaced by another one off-the-shelve is not common practice either, the purchasing process is still very much a headache 11-Oct-20 11:44 PM https://www.youtube.com/watch?v=vKnh9dxOyhE&ab_channel=EdwardsVacuum 11-Oct-20 11:44 PM In this video it looks like the foam part makes up like 90% of the volume of the tip seal 11-Oct-20 11:50 PM You say that but swagelok discounts are like 3% 11-Oct-20 11:50 PM Also you have no idea how highly I value that I can just call lesker 11-Oct-20 11:51 PM Swagelok has very little competition though... 11-Oct-20 11:51 PM And talk to the same two guys 11-Oct-20 11:51 PM Like lesker has done exactly what it needs to for people leaving academia to be like “oh, yeah it costs more but it’s worth it for the customer service” 11-Oct-20 11:51 PM We get 15-20% off their website prices too 11-Oct-20 11:51 PM Depending if they make it or not 11-Oct-20 11:51 PM They don’t include tracking numbers though 11-Oct-20 11:51 PM Ever. 11-Oct-20 11:51 PM You have to ask every time. 11-Oct-20 11:54 PM They do offer overnight shipping right? 11-Oct-20 11:55 PM Less so in Canada 11-Oct-20 11:55 PM They always cross the border before shipping to customer 11-Oct-20 11:55 PM Even for stuff from Europe 11-Oct-20 11:57 PM Yeah, don't tell me about swagelok... I was asking for quotation for big amount (thousands) of VCRs because of project we are preparing. I was hoping to get some decent discount, because budget is tight and guess what? No discount whatever, because "we were just quoting, now ordering right now" 11-Oct-20 11:58 PM I'd be really open to Swagelok/Nupro alternatives 11-Oct-20 11:58 PM But haven't found much so far, also swagelok is only expensive if you buy new 12-Oct-20 12:04 AM I know that Parker has a lot of "swagelok compatible" products (at least compression fittings and VCRs), but I don't know their prices... 12-Oct-20 12:09 AM Yor-lok from McMaster is fine 12-Oct-20 12:09 AM It’s a bit cheaper for standard parts 12-Oct-20 07:36 PM Bear in mind at some point swagelok fittings changed ever so slightly but not enough to be compatible nuts threads and crush rings so if say you have a valve that needs new crush cups the new ones may not fit. 13-Oct-20 11:44 AM Guess who forgot to check the lab for optic rails before buying some for a periscope? 13-Oct-20 11:47 AM You use rails for that?... 13-Oct-20 11:49 AM Yeah. Rails hold the mirror mounts 13-Oct-20 11:49 AM Lighting sucks and can't get both in frame, but this is the first periscope the lab built 13-Oct-20 11:49 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20201013_144957-24922.jpg 13-Oct-20 11:49 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20201013_145039-4A529.jpg 13-Oct-20 11:49 AM Think that's slightly better lighting 13-Oct-20 11:49 AM Apparently I meant giant posts and not rails 13-Oct-20 11:59 AM I don't like that 13-Oct-20 11:59 AM I guess that's normal according to thorlabs 13-Oct-20 11:59 AM I prefer the cages 13-Oct-20 11:59 AM apparently I'm wrong 13-Oct-20 12:01 PM I guess a cage would work too, but the post system works well 13-Oct-20 12:01 PM Isolated bottom post, clamp on a mounting plate, and put your mirror/prism mount on the mounting plate 13-Oct-20 12:10 PM I only have one periscope on my table 13-Oct-20 12:10 PM and it's for the weakest of weak beams, and it's in a box 13-Oct-20 12:10 PM I don't like beams pointing up 13-Oct-20 12:17 PM We don't have many. Easily the most dangerous thing in the lab. 13-Oct-20 12:17 PM But we don't have a choice 13-Oct-20 12:17 PM The droplet beam is roughly eye level 13-Oct-20 12:17 PM The laser needs to be there as well 13-Oct-20 12:17 PM At least it can be covered with beam tubes 13-Oct-20 12:18 PM mine is super low 13-Oct-20 12:18 PM Or I guess they call it lens tubes 13-Oct-20 12:18 PM like waist height almost 13-Oct-20 12:18 PM Ours has to be high because we have the giant diff on the expansion chamber 13-Oct-20 12:18 PM you'd need a hole in the floor for that here 13-Oct-20 12:18 PM I would love to see a droplet machine with four 2000 L/s turbos on the source chamber 13-Oct-20 12:18 PM you could make it even bigger I guess an have more than that 13-Oct-20 12:18 PM but a simple six-way ISO-250 cross could have four 13-Oct-20 12:21 PM At a certain point you have to stop asking if you can and ask why 13-Oct-20 12:21 PM Which granted 13-Oct-20 12:21 PM Our diff is probably in why territory 13-Oct-20 02:41 PM @Mason_Yu never finished my attempt, I was starting it just around the time the pandemic started in the USA and then got mentally swamped. I'm at the stage of being ready to attempt to grind the wear marks with some diamond coated rotary tools 13-Oct-20 05:12 PM Did you get new tip seals for your pump? 13-Oct-20 06:57 PM Nah figured I'd try refinishing the metal first and try again with the old seals, and if that showed promise then splurge the $200 on new ones 13-Oct-20 07:14 PM CNC mill out for delivery to me \o/ 13-Oct-20 07:14 PM I just don't know if I have time to construct it today :/ 13-Oct-20 07:14 PM I've never assembled a mill before, so I hope I am not a dum dum when doing this 15-Oct-20 08:29 PM Joined the server. 15-Oct-20 11:37 PM Joined the server. 15-Oct-20 11:37 PM Welcome, new people! 16-Oct-20 10:45 AM #introductions_and_directory pls 16-Oct-20 11:22 AM meow people 16-Oct-20 11:23 AM Meowdy 16-Oct-20 11:23 AM hoot~ 16-Oct-20 11:37 AM welcoming bear noises 16-Oct-20 01:33 PM <𝓕ermion#6024> hey has anyone played around with feedthroughs made of isolating material? 16-Oct-20 01:33 PM <𝓕ermion#6024> macor, peek, etc 16-Oct-20 01:33 PM <𝓕ermion#6024> feels a bit weird sealing 3He against plastic but lol 16-Oct-20 03:41 PM I've done some with black rubber laboratory stoppers 16-Oct-20 04:00 PM Joined the server. 16-Oct-20 04:01 PM #introductions_and_directory pls 16-Oct-20 04:01 PM humour me 16-Oct-20 04:02 PM While I appreciate you reminding the new folks I just want to add that it isn't a must to introduce yourself, just nice to see what kind of people we get here 16-Oct-20 04:13 PM @GigaSquirrel Allow me to introduce myself. My name is Wile E. Coyote, genius. 16-Oct-20 04:13 PM I am not selling anything nor am I working my way through college, so let's get down to basics, you are a rabbit and I am going to eat you for supper. 16-Oct-20 04:13 PM Now don't try to get away, I am more muscular, more cunning, faster and larger than you are and I am a genius, while you could hardly pass the entrance examinations to kindergarten, so I'm going to give you the customary two minutes to say your prayers. 16-Oct-20 04:14 PM perfect 16-Oct-20 04:36 PM the introductions are the most interesting part 16-Oct-20 04:39 PM idmb see new intro post uwu 16-Oct-20 05:08 PM thanks 16-Oct-20 05:08 PM made my day 16-Oct-20 08:41 PM Joined the server. 16-Oct-20 08:57 PM hey @Lucanis 16-Oct-20 08:58 PM Hey buddy 17-Oct-20 02:31 AM Has anyone got experience with Quantum espresso? I’m looking at using it for H/D embedding in a metal Lattice Confinement, electron screening context. If there are better alternatives I’d love to hear them. 17-Oct-20 09:40 AM Nope, haven't heard of it 17-Oct-20 10:57 AM Quantum espresso is okay. No personal experience, but I think it's one of the better true free materials ab initio softwares 17-Oct-20 10:57 AM Is what solid state friends tell me anyway 17-Oct-20 10:57 AM And what they use at least some 17-Oct-20 10:58 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-2C23D.png 17-Oct-20 10:58 AM had fun with a random lens taped to my phone + a ccfl inverter and a burned out bulb 17-Oct-20 11:12 AM I’ve heard good things about Espresso 17-Oct-20 11:12 AM I’ve never done any dft stuff 17-Oct-20 11:12 AM if you ever need free MD software though highly recommend LAMMPS 17-Oct-20 11:20 AM https://lammps.sandia.gov/download.html 17-Oct-20 11:20 AM https://www.quantum-espresso.org/download 17-Oct-20 11:20 AM im gonna install both lol 17-Oct-20 11:42 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-AB917.png 17-Oct-20 11:42 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-043DB.png 17-Oct-20 11:42 AM not sure if it was obvious so i messed with the levels to make the light/dark alternating pattern more apparent 17-Oct-20 11:42 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-7A1FA.png 17-Oct-20 04:03 PM Joined the server. 17-Oct-20 06:14 PM Joined the server. 17-Oct-20 07:35 PM Talked to the solid state theorist I know some. They said Quantum Espresso can almost assuredly do this but you probably won't be able to find any documentation on how to do it. 17-Oct-20 07:35 PM So...have fun 17-Oct-20 07:35 PM And the QE developers are very unhelpful 17-Oct-20 09:19 PM Yeah all the DFT stuff is super dense to get into, it almost seems like you need a mentor and strong math background 17-Oct-20 09:19 PM I'm an industry liaison for the SemiSynBio Industry:NSF joint funding program, and have had the pleasure of listening in on a bunch of meetings where experts were conversing with academics (professor and their grad student). It's been pretty fun. 17-Oct-20 09:19 PM Their interest was DNA conduction mode studies, for trying to build self-assembling DNA ROMS (memories) 17-Oct-20 09:25 PM In general learning DFT on your own is a mistake, yeah, but apparently QE is like CFOUR in the molecule space where the documentation is just not there and the software itself doesn't give you helpful errors. Not sure if you need a strong math background per se, but it definitely wouldn't hurt. 17-Oct-20 10:11 PM I'd be up for a PhD involving nanofab engineering and DFT mentorship... But not sure I could swing it with the amount of projects I already have... Maybe if I diligently check projects off as done in the next 3-5 years... Maybe 18-Oct-20 09:48 AM Espresso has a really bad api 18-Oct-20 09:48 AM From my personal experience 18-Oct-20 09:48 AM Use Atomic Simulation Environment 18-Oct-20 09:48 AM ASE Makes writing input files basically automatic 18-Oct-20 11:46 AM Joined the server. 18-Oct-20 06:56 PM time in minutes. I don't undestand vacuum science 18-Oct-20 06:56 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screen_Shot_2020-10-18_at_6.56.01_PM-02447.png 18-Oct-20 09:58 PM interesting 19-Oct-20 10:12 AM another 10 lol 19-Oct-20 10:12 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-9DE4F.png 19-Oct-20 10:17 AM And this is a turbo right? 19-Oct-20 10:36 AM yeah 19-Oct-20 10:36 AM it's weird because of how periodic it is. 19-Oct-20 10:38 AM Yeah I wouldn't expect that from a turbo 19-Oct-20 10:38 AM At least at the timescales that surely is 19-Oct-20 10:38 AM idk out of equilibrium stuff I don't have any intuition for 19-Oct-20 10:38 AM Like molecular beams are still magic to me 19-Oct-20 12:23 PM Few years ago, In school I had a class called "vacuum engineering". It included a practical assignments, one of which was called "vacuum measurement". It was just simple vacuum apparatus with RVP and turbo with five different vacuum gauges attached (capacitive, piranni, penning, bayard-alpert, some obscure spining rotor gauge and RGA). And our task was just to turn on logging of measured values, turn on pumping, record log and make "evaluation report", describing what we saw. And since that time, I am quite depressed any time I see any vacuum gauge and I look only on exponent number on my pressure readings... 19-Oct-20 12:33 PM Like a proper physicist! "We are on the correct decade, so it's likely correct." 20-Oct-20 05:01 AM hi, what's an easy method for depositioning 1 micrometer thick al2o3 layers? 20-Oct-20 05:01 AM sputtering with a little bit of oxygen? 20-Oct-20 06:17 AM yeah needs to be rf sputtering tho.. looks like O2:Ar ratio of 1:5. 20-Oct-20 06:17 AM https://iopscience.iop.org/article/10.1088/1742-6596/850/1/012022/pdf 20-Oct-20 06:19 AM hm thanks 21-Oct-20 12:32 PM Hi, I have something I can't really wrap my head around but I am sure some of you will know the answer, in a dc magnetron sputtering setup (like the one in the picture below) why is it not arcing between the magnetron and shield? 21-Oct-20 12:32 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/427395_1_En_3_Fig1_HTML-3680F.gif 21-Oct-20 12:34 PM because the potential is not high enough 21-Oct-20 12:34 PM above the target it can arc, because the magnetic field lowers the needed voltage, but between the magnets and shield the magnetic field is way too low for that effect 21-Oct-20 12:44 PM Oh got it, make sense thanks! 21-Oct-20 12:44 PM So I have must have done something very wrong 21-Oct-20 12:44 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_20201003-162507-5C35C.jpg 21-Oct-20 12:44 PM Mine is arcing around the magnetron to the shield not producing the plasma torus, I guess the magnet doesn't produce the required field 21-Oct-20 12:54 PM the iron pole piece the target sits on is important 21-Oct-20 12:54 PM does your setup have that? 21-Oct-20 12:57 PM it does, let me send you a cross section view of my magnetron 21-Oct-20 12:57 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-CAD9B.png 21-Oct-20 12:59 PM red is what material? 21-Oct-20 12:59 PM orange part is a neodyme magnet 21-Oct-20 12:59 PM red is aluminium 21-Oct-20 12:59 PM yellow magnetic steel 21-Oct-20 12:59 PM blue and green aluminium too 21-Oct-20 12:59 PM hmm 21-Oct-20 12:59 PM looks fine to me 21-Oct-20 12:59 PM and your magnet is magnetized along the axis of the magnetron? 21-Oct-20 01:02 PM oh you made me notice something really interesting 21-Oct-20 01:02 PM that's normal 21-Oct-20 01:02 PM but 21-Oct-20 01:02 PM That doesn't look right at all 21-Oct-20 01:08 PM not really, no 21-Oct-20 01:11 PM I am using a stack of two neodymium magnets maybe that's the issue ? 21-Oct-20 01:11 PM or is it not the right kind of magnet ? 21-Oct-20 01:13 PM not sure tbh 21-Oct-20 01:13 PM do you have some pics of your sputter gun? 21-Oct-20 01:16 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-B2EDF.png 21-Oct-20 01:16 PM without the shield 21-Oct-20 01:17 PM sure 21-Oct-20 01:17 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20201021_221702-11D97.jpg 21-Oct-20 01:17 PM some may say that's a lot of damage 21-Oct-20 01:19 PM huh 21-Oct-20 01:19 PM I mean it all looks right 21-Oct-20 01:19 PM if you'r emissing something so am I 21-Oct-20 01:25 PM let me show you something else 21-Oct-20 01:25 PM what pressures are you working at? 21-Oct-20 01:25 PM what pumps do you have? 21-Oct-20 01:26 PM I did that test tonight plasma was generating below the magnetron and arcing when voltage was too high 21-Oct-20 01:26 PM a mecanical edwards 2.5m pump and turbomolecular pump that wasn't used in this test, pressure was 200mTorr 21-Oct-20 01:28 PM it might just be too much pressure 21-Oct-20 01:28 PM watch the discharge as you pump as low as it goes 21-Oct-20 01:29 PM honestly it felt like it was working better and better the lower the pressure 21-Oct-20 01:29 PM so you are probably right 21-Oct-20 01:34 PM I'm not sure at what pressures sputtering is usually done but 200 mtorr is just intuitively... a lot 21-Oct-20 01:40 PM I have read from 22mtorr to 2200mtorr but this very well may be incorrect depending on the setup 21-Oct-20 01:53 PM 2200 mtorr sounds wayyy too high lol. Tools I’ve used have been around 50 mtorr 21-Oct-20 01:53 PM How are you sealing your threads on the spark plug feedthroughs? I ran into issues with that in my build, lots of leaks from threads 21-Oct-20 01:58 PM Thanks for the info 21-Oct-20 01:58 PM Its sealed with jb weld epoxy 21-Oct-20 02:22 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_20201021-232232-A4E1C.jpg 21-Oct-20 02:22 PM 160mTorr 21-Oct-20 02:24 PM we need to go lower! 21-Oct-20 02:30 PM 145mTorr, for some reason the turbopump just seem to increase the pressure when started, I have never tried it before, maybe it's dirty or spinning in the wrong direction 22-Oct-20 04:04 AM Hello everyone 22-Oct-20 04:04 AM I have a safety question 22-Oct-20 04:04 AM I'm bombarding a piece of glass with a 20kv electron beam 22-Oct-20 04:04 AM And I'm looking through a small window with my eyes 22-Oct-20 04:04 AM I would like to know if I'm already dead 22-Oct-20 04:11 AM it's not too bad, but I'd check it with an end window GM / ion chamber anyways 22-Oct-20 04:13 AM I think I may screw my life looking at that window 22-Oct-20 04:13 AM Many hours 22-Oct-20 04:13 AM I'm looking a Geiger counter in aliexpress for measure low energy x Ray's radiation 22-Oct-20 04:14 AM for energies this low it has to be end window 22-Oct-20 04:14 AM like alpha sensitive 22-Oct-20 04:15 AM "End window " is a special material? 22-Oct-20 04:15 AM Lead glass 22-Oct-20 04:16 AM end window geiger counters have a special window on one side that's very thin and barely attenuates radiation, making it possible to register stuff that's easily stopped, like alphas an low energy photons 22-Oct-20 04:18 AM Oh, i understand. The Geiger counter should have an end window 22-Oct-20 04:18 AM Not the chamber 22-Oct-20 04:19 AM yes 22-Oct-20 04:19 AM but lead glass in your chamber is never a bad idea 22-Oct-20 04:20 AM I think I'm going to die from brain cancer 22-Oct-20 04:20 AM nah, such low energy x-rays don't penetrate that far 22-Oct-20 04:20 AM might have messed up your eyes 'tho 22-Oct-20 04:51 AM Intensity of Bremsstrahlung is proportional to the atomic number of target, I think that from glass you will not get significant xray production... 22-Oct-20 04:52 AM that's true 22-Oct-20 04:52 AM doesn't mean it shouldn't be checked anyways 22-Oct-20 04:53 AM That is definitely true, this remark was just to calm down Kevin... 22-Oct-20 07:29 AM At 20kV, as long as your window isn’t optical grade quartz you’re probably fine. But I wouldn’t snuggle up to it either. 22-Oct-20 11:34 AM @KevinSchuller "mica window" 22-Oct-20 11:34 AM You can also get dosimeter pens made from carbon fiber that are good at recording total dose of low energy radiation. 22-Oct-20 11:37 AM Thank Adam 22-Oct-20 11:37 AM I didnt know about dosimeter pens 22-Oct-20 11:37 AM For recording cumulative radiation 22-Oct-20 12:30 PM Caution: the metal ones are insensitive to lower energies. Make sure you get a carbon fiber or plastic one if you are expecting to use it with x-ray 22-Oct-20 07:25 PM I wish there were more strong molecules 22-Oct-20 07:25 PM everything else just burns 22-Oct-20 07:32 PM As someone who needs to burn things to make samples, I'm glad most things burn 22-Oct-20 07:39 PM if I use the full vapour pressure of CS2 22-Oct-20 07:39 PM I can only use like 10% of my centrifuge 22-Oct-20 07:39 PM laser is too strong 22-Oct-20 07:39 PM (really, I should just focus with a longer lens) 22-Oct-20 07:45 PM Isn't it easier to just turn down the centrifuge power though? 22-Oct-20 07:45 PM Rather than changing the set up to accommodate a longer focal length lens? 22-Oct-20 07:46 PM yes but then you're wasting laser 22-Oct-20 07:46 PM longer focal length = more sample 22-Oct-20 07:46 PM Oh. Have fun with that change then 22-Oct-20 07:46 PM I set it up asymmetrically 22-Oct-20 07:46 PM it's this 22-Oct-20 07:46 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/1-D13FA.png 22-Oct-20 07:46 PM but the two lenses before the gas cell are f=6cm and f=15cm 22-Oct-20 07:46 PM the gas cell is actually a 2.75" conflat cross 22-Oct-20 07:46 PM so I can just swap the lenses and in theory if I align them correctly, all is well. 22-Oct-20 07:46 PM (it's just Raman) 22-Oct-20 07:48 PM So is the longer focal length more about the laser being mostly "focused" for longer rather than the actual resulting focus then? 22-Oct-20 07:48 PM yeah longer = focused less tightly but focused for longer 22-Oct-20 07:48 PM Okay yeah, makes sense 22-Oct-20 07:49 PM gaussian optics are silly 22-Oct-20 07:49 PM Indeed 22-Oct-20 07:49 PM I have like no intuition 22-Oct-20 07:49 PM And just know how to time propagate it with transfer matrices 22-Oct-20 07:49 PM I basically just assume "scales with area of input beam, scales quadratically with focal length" and the intuition is close enough 22-Oct-20 07:49 PM More or less 22-Oct-20 07:49 PM I guess time propagate is the wrong word 22-Oct-20 07:49 PM But you know what I mean 22-Oct-20 07:49 PM That one equation 22-Oct-20 07:49 PM The q factor I think it's called 22-Oct-20 07:49 PM matrices are for undergrads and theorists. 22-Oct-20 07:50 PM The molecular beam frequency comb group here disagrees :p 22-Oct-20 07:50 PM (no, but like, please don't make me mess around with that again ugh) 22-Oct-20 07:50 PM Though they're crazy enough to do that 22-Oct-20 07:50 PM So I'm not sure what that says about them 22-Oct-20 07:50 PM have you looked at the transfer matrix approach to laser cavity stability? 22-Oct-20 07:50 PM Yeah 22-Oct-20 07:50 PM gross 22-Oct-20 07:50 PM Indeed 22-Oct-20 07:50 PM Especially when you try to factor that matrix 22-Oct-20 07:50 PM And realize your resulting answer isn't necessarily physically possible 22-Oct-20 07:50 PM So then I thought about trying to use convex optimization to help 22-Oct-20 07:50 PM And then I realized I said those words 22-Oct-20 07:50 PM And stopped trying 22-Oct-20 07:51 PM and irl the cavity made with off-the-shelf components works just as well as the optimally-curved refocusing mirror anyways. 22-Oct-20 07:52 PM In most cases yeah 22-Oct-20 07:52 PM That particular group is at the level where they actually need ACTUALLY STABLE cavities though 22-Oct-20 07:52 PM Which is disgusting 22-Oct-20 07:52 PM FORGOT TO TAKE THERMAL LENSING OF THE AIR NEAR THE OPTICAL ELEMENTS INTO ACCOUNT 22-Oct-20 07:52 PM But hey, orders of magnitude more power I guess 22-Oct-20 07:52 PM Yeah that's a real thing they see a lot 22-Oct-20 07:52 PM centrifuge spins with 100mw 22-Oct-20 07:53 PM "hmm, my power is 20% of what it should be and I don't know why" 22-Oct-20 07:53 PM Also, imagine actually having to know what your laser's M^2 is 22-Oct-20 07:53 PM Though tbh it would be nice to know it in reality 22-Oct-20 07:53 PM Like I'm pretty sure the wavemeter I made (it sucks) has that as it's biggest source of error. The wavefront isn't actually gaussian 22-Oct-20 07:53 PM And while I don't know how to correct that right away, I'm sure there is a way if you know the M^2 22-Oct-20 07:53 PM Or better yet just have a picture of the beam 22-Oct-20 07:57 PM another group asked if we had a wavemeter 22-Oct-20 07:57 PM because they wanted to tune their dye laser 22-Oct-20 07:57 PM I said no we just have a little fiber spectrometer 22-Oct-20 07:57 PM turned out their thing was like 50nm off though 22-Oct-20 07:57 PM so the 0.125nm precision was plenty 22-Oct-20 07:57 PM Yikes 22-Oct-20 07:57 PM Optogalvanic calibration is probably the way to go there. Nice combo of ease+cost and accuracy 22-Oct-20 07:57 PM Also, as a general statement, if you need a wavemeter, just buy it. It won't be an easy build even if you think it will be 22-Oct-20 07:57 PM And so much of the cost of a commercial one is the detector anyway 22-Oct-20 07:57 PM So you don't even save much money 22-Oct-20 07:57 PM Don't be me 22-Oct-20 08:02 PM Anything you can buy, buy 22-Oct-20 08:02 PM Or steal from another group 22-Oct-20 08:03 PM Boss doesn't always agree, but in general yeah 22-Oct-20 08:03 PM I'm just saying wavemeters in general are especially deceptive 22-Oct-20 08:03 PM Especially because we tend to start thinking about homebrew solutions when things start getting to that price range 22-Oct-20 08:03 PM Though in this instance it's a big mistake 22-Oct-20 08:07 PM I gave them a diffraction grating 22-Oct-20 08:07 PM And told them that and a protractor can do better, if they really care. 22-Oct-20 08:10 PM I'm not sure what their use case is, but I really do recommend optogalvanic calibration. Just requires a uranium or neon lamp (and some others, but those are the big two), and it was the gold standard before wavemeters so you should be pretty easily able to just find them lying around 22-Oct-20 08:10 PM https://ieeexplore.ieee.org/document/278559 22-Oct-20 08:14 PM I have no clue either 22-Oct-20 08:14 PM Tbh we just rotate the grating on the spectrometer so the middle is 400nm 22-Oct-20 08:14 PM The % error is negligible 22-Oct-20 08:14 PM For what we do 22-Oct-20 08:20 PM I wish we could get away with that tbh. We have the nice Fizeau that has like 50 MHz resolution for the low bandwidth OPO, the dye laser is optogalvanic which gets you to a few wavenumbers, and then my wavemeter gets like .3-3 wavenumbers depending on the actual pulse 22-Oct-20 08:20 PM Which granted, is good enough, but still feels bad 22-Oct-20 08:20 PM Almost as bad as when I did the PGOPHER simulation and saw that I won't be getting rotational resolution ever 22-Oct-20 08:20 PM At least for cations 22-Oct-20 08:22 PM The whole point of the centrifuge stuff is it’s nonresonant 22-Oct-20 08:22 PM Also, unrelated, but would it be dumb for me to make a periscope shroud that's not air tight and then just...cover it with an acrylic purge box later? 22-Oct-20 08:23 PM You need very little airflow to purge 22-Oct-20 08:23 PM Leaks should be ok? 22-Oct-20 08:24 PM Hmm, probably I guess. I really don't know anything about this tbh 22-Oct-20 08:24 PM Kind of just a "oh by the way you'll need to purge this later" 22-Oct-20 08:26 PM Aren’t you just doing a “lets have 90% less water” thing 22-Oct-20 08:26 PM Not “let’s have no water” 22-Oct-20 08:26 PM I think so? 22-Oct-20 08:26 PM He's been very nonspecific about how extreme we actually need this to be 22-Oct-20 08:26 PM Because I think there is some world where we need it to be basically completely dry because of wavefront things 22-Oct-20 08:26 PM But I don't know if we live in that world 22-Oct-20 08:28 PM We just do it sometimes to keep optics clean 22-Oct-20 08:28 PM It will mostly be that plus extra power 22-Oct-20 08:28 PM Though...99% sure we have way too much power as is 22-Oct-20 08:28 PM At least for most things 22-Oct-20 08:28 PM Like we have more power than he had during his post doc on a similar set up, and there's a paper from there where we basically said "we think the theory is correct, but our laser power was way too high so our intensities are very wrong" 22-Oct-20 08:28 PM And yes...he is still publishing data from his post doc somehow 22-Oct-20 08:28 PM Though to be fair that was HO4+ which is every bit as bad as that string says it would be 22-Oct-20 08:28 PM Actually worse than that string makes you think 22-Oct-20 08:28 PM Because that sounds like a proton bound dimer which it's not 22-Oct-20 08:28 PM Actually a string of 4 oxygens 22-Oct-20 08:33 PM Should be called OOOOH 22-Oct-20 08:33 PM Probably 22-Oct-20 08:33 PM But everyone kind of assumed it wasn't actually OOOOH 22-Oct-20 08:33 PM But it is 22-Oct-20 08:33 PM ALmost as good as FOOF 22-Oct-20 08:33 PM Though I'm personally waiting on FOOOF 22-Oct-20 08:33 PM If HOOOH exists I'm sure we can add some fluorines 22-Oct-20 08:34 PM HOHO chain 22-Oct-20 08:34 PM I like HeHe 22-Oct-20 08:34 PM And HEI 22-Oct-20 08:34 PM HeI 22-Oct-20 08:37 PM I mostly like cursed things that sound like they shouldn't exist 22-Oct-20 08:37 PM Like H5+ 22-Oct-20 08:37 PM Or ArOH+ 22-Oct-20 08:37 PM And it's kind of routine but I guess H3+ also counts 22-Oct-20 08:47 PM same 22-Oct-20 08:58 PM https://en.wikipedia.org/wiki/Argon_compounds 22-Oct-20 08:58 PM Argon forms a clathrate with hydroquinone (HOC6H4OH)3•Ar. When crystallised from benzene under a pressure of 20 atmospheres of argon, a well defined structure containing argon results. An argon-phenol clathrate 4C6H5OH•Ar is also known. It has a binding energy of 40 kJ/mol. Other substituted phenols can also crystallise with argon. The argon water clathrate is described in the Aqueous argon section. 22-Oct-20 08:58 PM oooh 22-Oct-20 11:30 PM Like H5+ @Mezmorizor ...how? You take a proton and remove four more electrons from it? 22-Oct-20 11:30 PM (are you sure you don't mean H5-?) 22-Oct-20 11:31 PM It's H_5+ 22-Oct-20 11:31 PM Proton bound dimer 22-Oct-20 11:31 PM But hydrogen 22-Oct-20 11:31 PM Actually not that weird when you think about it 22-Oct-20 11:31 PM But the formula gives you real pause 22-Oct-20 11:32 PM I don't understand how that works 22-Oct-20 11:32 PM oh 22-Oct-20 11:32 PM 5 hydrogens with one positive charge 22-Oct-20 11:33 PM H2 - Proton - H2 22-Oct-20 11:33 PM The proton stabilizes it a lot because it significantly delocalizes everything 22-Oct-20 11:33 PM And HO4+ is so weird because it's not that. It's OOOOH+ 22-Oct-20 11:35 PM ooooh! 22-Oct-20 11:35 PM Oh that reminds me about argon compounds being annoying ICP-MS interference sources 22-Oct-20 11:35 PM And that sounds wild 23-Oct-20 01:46 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20201023_014506-231AB.jpg 23-Oct-20 01:46 AM I cannot find the manual for this particular pump but from what I have seen from similar Alcatel pump manuals, this one is a chemical pump (with n2 purge) and likely can operate in any orientation (it has two bearings, and was found originally installed sideways, but all the marketing materials show it upright?). 23-Oct-20 01:46 AM I should probably mount it upside down then so that I don't accidentally injest any particulate, or put crazy sideways toruqes on my vacuum chamber. 23-Oct-20 01:46 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_20201023-014828_Drive-2EB18.jpg 23-Oct-20 01:54 AM Just be aware that it probably doesn't have drag stage so your forevacuum should be "better than with modern turbos" (we want at least ~0.1 Pa for such pumps) 23-Oct-20 02:00 AM Yeah I don't think it has a drag stage. 23-Oct-20 02:00 AM I had a welder make me a CF to LF adapter, which was the last big missing part to this vacuum chamber, but after assembling this, the gate valve and turbo together it became really apparent that it was going to be too long to mount horizontally like I originally thought it was going to. It felt like something was going to break :-). 23-Oct-20 06:41 PM Speaking of nitrogen purge turbos, does anyone know if TMH-260P (p is for purge) requires N2 or is it like a bonus type deal? 23-Oct-20 10:45 PM I think it's just in case you're dealing with corrosive stuff that would affect the bearing and/or bearing oil 23-Oct-20 10:45 PM If you don't supply it, likely you'll need to block off that inlet 23-Oct-20 10:52 PM we have a TMH-260 with a purge port but it doesn't say 260P anywhere on it 23-Oct-20 10:52 PM never purged it 23-Oct-20 11:55 PM No clue. I do have a TMH260 I’d get rid of for cheap if someone wants it 24-Oct-20 12:07 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_20201024-000736-34DAF.png 24-Oct-20 01:14 AM Thanks so much! Sounds like it’s not integral to how the bearings function... 25-Oct-20 03:14 AM I bought a used turbovac50, then tried to dismount it to see if everything was in order and it is filled with that black dust (top part is already cleaned but it was black) I'll need to dismount the rotor assembly to clean everything up (I can see through the holes that the blades are black, any clue how that black stuff got there/what happened to that poor pump? 25-Oct-20 03:14 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20201025_110914-932CA.jpg 25-Oct-20 09:36 AM What does the manual say about disassembly and cleaning for that turbo? 25-Oct-20 09:36 AM I know on the small ones I have worked on as long as you removed the motor winding bit you can submerge the whole thing in a cleaning solution 25-Oct-20 10:07 AM Probably just used for some high temperature process. Any Organic material+heat=black dust 25-Oct-20 11:31 AM Only thing they say about disassembly or cleaning is that it has to be done by trained personnel at Leybold, I ended up dismounting the whole thing to clean everything up, but your solution should work on that turbo, thanks for the tip 25-Oct-20 11:31 AM @Mezmorizor ahh makes sense thanks! Guess this pump had a whole living thing for dinner 25-Oct-20 11:31 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20201025_153733-551AD.jpg 25-Oct-20 11:31 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20201025_150838-E3664.jpg 25-Oct-20 11:56 AM Jeez that's a lot regardless 25-Oct-20 12:11 PM every company says only that company should do stuff 25-Oct-20 12:51 PM ^ 26-Oct-20 09:30 AM Joined the server. 26-Oct-20 05:45 PM <𝓕ermion#6024> anyone here particularly good at welding? 26-Oct-20 05:45 PM <𝓕ermion#6024> I tried the welding discord but wasn’t super pleased 26-Oct-20 07:31 PM FACT: I am a garbage welder. 27-Oct-20 12:50 AM I got a shiny new TIG welder this summer, not particularly good, but haven't practiced much. Owned a wire feed gasless fluxcore unit for more than a decade. Started on stick. Haven't done that much overall though 27-Oct-20 01:06 AM FACT: I am a garbage welder. @funranium the people at all power labs are great at welding if you need welding done 28-Oct-20 06:44 PM I’m betting @funranium is a better welder than these guys: 28-Oct-20 06:44 PM https://www.youtube.com/watch?v=h7NFySg1KrA&t=9m6s 28-Oct-20 06:44 PM “Instead of welding mask, I have pliers and hand.” 28-Oct-20 07:25 PM ...I don't want to win this fight. Definitely not anywhere near them. 28-Oct-20 07:27 PM While we're on the subject of things @funranium has commentary about 28-Oct-20 07:27 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20201028_192529-9497D.jpg 28-Oct-20 07:27 PM Back from the days when you'd stare into x-ray beams :-) [the source has been removed don't worry] 28-Oct-20 07:34 PM Aww hell, those things. 28-Oct-20 07:46 PM Apparently the company is still in business 28-Oct-20 07:46 PM https://lixi.com/ nowadays I think they use a field emission tube 28-Oct-20 08:51 PM What is that? 28-Oct-20 10:08 PM Handheld field fluoro for part and weld inspection. They were not nearly as safe as they claimed. 28-Oct-20 10:23 PM The line from Ghostbusters comes to mind. “Why worry. Each one of us is wearing a unlicsenced nuclear accelerator on his back. 30-Oct-20 05:29 AM never worked with uhv before -- i have a small chamber that has been pumped down with a turbopump and ion pump without bakeout and it seems to have equilibrated to 1e-8 mbar over about three days without going down further. is this normal, or is there a leak? 30-Oct-20 05:29 AM my chamber is mostly stainless steel but has a pyrex glass cell attached to it 30-Oct-20 06:45 AM Without bake out it’s hard to say. You have to start looking at possible contamination. Greases and surface films, any gasketing material, etc. materials can hold that much vapors especially water and that is about the plateau of some systems. Can you bake it? Then you would know for sure. 30-Oct-20 07:05 AM @vapicuno are you logging the pressure? If it’s steady, seems like a tiny leak. 30-Oct-20 07:05 AM But if it’s not leaking, it should be ticking down very slowly, unless it was ridiculously filthy. Even an unbaked chamber will slowly go down further. 30-Oct-20 07:07 AM What flanges? That's roughly the limit of KF/any rubber o ring flange 30-Oct-20 07:09 AM Its cf flanges 30-Oct-20 07:09 AM I will eventually bake it, but is it reasonable to bake it when i dont know if theres a leak? 30-Oct-20 07:09 AM The stuff in my chamber apart from the stainless steel and glass are a uhv gate valve with a viton seal and an electrical feedthrough. 30-Oct-20 07:22 AM Viton outgasses quite a bit 30-Oct-20 07:24 AM Nah 30-Oct-20 07:24 AM The uhv -11 valves from VAT still have it 30-Oct-20 07:25 AM yeah I thought it doesn't outgas, but at ~e-8 diffusion through it becomes significant 30-Oct-20 07:25 AM @vapicuno does your gauge update quickly? Sprinkle alcohol on the flanges (CF have little spots for leak testing) and look for any change in pressure 30-Oct-20 07:30 AM I was thinking permeation more than outgassing I guess, but it does outgas significantly. Especially if it's not vacuum baked and is newish. Probably not the reason though 30-Oct-20 07:31 AM Yeah the gauges update quickly, i can try that 30-Oct-20 07:31 AM My stuff is all new 30-Oct-20 07:32 AM You didn’t answer if it was actually steady, or just going down verrrry slowly 30-Oct-20 07:32 AM It seemed steady for the past three days or so down to the second significant figure 30-Oct-20 07:32 AM I could be wrong, i didnt log it carefully but thats what it seemed like 30-Oct-20 07:33 AM Well if it’s doing that then it may just be outgassing. 30-Oct-20 07:33 AM Great thing about the alcohol test is it doesn’t do anything bad if there’s no leak 30-Oct-20 07:33 AM Win / don’t lose 30-Oct-20 07:34 AM The alcohol test works at -8? 30-Oct-20 07:34 AM At what pressures does it become undetectable 30-Oct-20 07:35 AM It usually works for me 30-Oct-20 07:35 AM At those pressures 30-Oct-20 07:35 AM What kind of alcohol? 30-Oct-20 07:35 AM I have methanol but i dont feel like poisoning myself lol 30-Oct-20 07:36 AM We use methanol, but I'm not sure if it really matters 30-Oct-20 07:37 AM Anything should be fine, what matters is high vapour pressure 30-Oct-20 07:37 AM If you have plastic around, methanol is the way to go 30-Oct-20 07:37 AM We use it or acetone or ipa because metal everywhere 30-Oct-20 07:38 AM Yeah i see, ill prob start with ipa 30-Oct-20 07:38 AM The most harmless of solvents 30-Oct-20 07:38 AM Or ethanol 30-Oct-20 07:38 AM It’s mean to some optical coatings 30-Oct-20 07:38 AM Ethanol is great 30-Oct-20 07:39 AM Does ethanol hurt coatings 30-Oct-20 07:39 AM Ive only cleaned stuff with methanol 30-Oct-20 07:39 AM I’ve been told to use methanol for everything but gratings, and ethanol for those, and I don’t know why. 30-Oct-20 07:40 AM Strange advice 30-Oct-20 07:40 AM I know camera people fight about whether ethanol or methanol is better for cleaning camera sensors, and both seem to argue the other is destructive. 30-Oct-20 07:40 AM I see 30-Oct-20 07:40 AM Id use methanol but im concerned about losing brain cells every time i spray 30-Oct-20 09:27 AM T size and K size helium 6.0 tanks are the same price for us lol 30-Oct-20 09:27 AM But T is currently ??? Weeks lead time and k was 3 hours 30-Oct-20 10:40 AM Every gas here has a standard size, so you see silly things like the biggest tank of high purity argon for $15 but $150 for the size right below it 30-Oct-20 10:40 AM Which on their end makes sense 30-Oct-20 10:40 AM But is still funny 30-Oct-20 10:42 AM k is the normal size though 30-Oct-20 10:42 AM they stock K, T is special order 30-Oct-20 10:42 AM And they're still the same price? 30-Oct-20 10:42 AM Weird 30-Oct-20 10:42 AM I guess airgas just hates us 30-Oct-20 06:07 PM At 1e-8 mbar is it reasonable to even try to identify any leak by turning off the pumps and watching the pressure go to equilibrium? 30-Oct-20 06:13 PM if you have a working valve in front of your pump, sure 30-Oct-20 06:13 PM I don't, so I would just discover that my forevacuum lines leak too much to sustain 1E-8 torr 30-Oct-20 06:40 PM lol 30-Oct-20 06:56 PM For real - on our proper system, we have a pneumatic valve behind the turbos which closes during a power failure. 30-Oct-20 06:56 PM It shut on a Friday and we still had -8 torr on Monday. 30-Oct-20 08:03 PM ah 31-Oct-20 01:31 AM $400 valve small price to pay to protect $5000 turbo 31-Oct-20 01:38 AM Protect? 31-Oct-20 03:54 AM Yeah only open the valves if you're sure it won't crash your turbo 31-Oct-20 08:37 AM if it's below 10E-2 on each side, it won't ever care with any I've seen 31-Oct-20 10:57 AM Hmm 31-Oct-20 10:57 AM I have something electric I want to put in 1E-8 torr ish 31-Oct-20 10:57 AM maybe more like 8E-8 torr 31-Oct-20 10:57 AM and it has some regular plastic-insulated wires built into it that I cant replace, about 2" long and a tiny gauge 31-Oct-20 10:57 AM how do I connect my uhv-ready kapton-coated copper wire to the bad wires? 31-Oct-20 10:57 AM Just solder + heatshrink and hope the gassing isn't too much? 250L/s turbopump with basically no other load. 31-Oct-20 11:13 AM How are your wire wrapping skills? 31-Oct-20 11:16 AM nonexistent 31-Oct-20 11:16 AM I think I'm gonna just go for the easy route 31-Oct-20 11:16 AM and say "oops" if it doesn't work well. 31-Oct-20 12:15 PM My buddy puts hobby motors in his FIB 31-Oct-20 12:15 PM I would suggest using some crimped connection and kapton self-adhesive tape as insulation. Soldering would be probably OK, but I would be really worried about the heatshrink - it either will outgass itself or it will create trapped volume which will be pain to pump off... 31-Oct-20 12:15 PM Been working fine for years 31-Oct-20 12:15 PM Just soaks them in isopropanol before to remove any bearing oil 31-Oct-20 12:15 PM Has soldered connections 31-Oct-20 12:15 PM Could just skip heat shrink and use super glue 31-Oct-20 12:15 PM For insulation 31-Oct-20 12:17 PM Hm. It's above a turbopump (with mesh) so I'm a bit hesitant on the tape 31-Oct-20 01:56 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/male_blade_parent-F2058.png 31-Oct-20 02:08 PM crimping would work I guess 31-Oct-20 02:16 PM Aren't those brass terminals? Usually zinc-containing things are not good for UHV... 31-Oct-20 02:16 PM you can get them in any metal 31-Oct-20 04:42 PM There are uhv compatible screw terminals, barrel contacts and crimp connectors you can buy @idmb 31-Oct-20 04:42 PM I got mine from vacom, a german company 31-Oct-20 04:42 PM I would probably strip the plastic off the entire wire too fwiw 31-Oct-20 04:44 PM Not really possible 31-Oct-20 04:44 PM I looked at some notes and the thing they’re on has been in uhv before with no issues so I’m just gonna see what happens 31-Oct-20 04:45 PM Mm ok 31-Oct-20 04:46 PM I think it’ll just take 2-3 days to get down then be fine 02-Nov-20 02:09 PM Question: Got a hold of a nice leak detector that serms to operate quite well but doesn't reach a decent count. Before leak checking the leak checker; is a light honey colored oil good enough and what level should it ideally be at? Below the ring of mild discoloration on the wall and above the drain into the boiling cup? 03-Nov-20 12:29 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20201102_225654-B58CF.jpg 03-Nov-20 12:29 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20201102_225557-E4168.jpg 03-Nov-20 12:29 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_20201102_185507-9AF67.jpg 03-Nov-20 02:50 PM I'm no expert, but that oil looks better than either of my rough pumps 03-Nov-20 02:50 PM And my fomblin pump seems to work fine for turbo backing 03-Nov-20 02:50 PM Who knows how to determine what controllers will work for a varian v80 turbo? 03-Nov-20 04:13 PM @Charles let me know if the cable for this would work for you, and I’ll map out the pins in the cable tomorrow 03-Nov-20 04:13 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-249FA.jpg 03-Nov-20 04:13 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image1-244E3.jpg 03-Nov-20 04:13 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image2-192DF.jpg 03-Nov-20 04:13 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image3-19DE6.jpg 03-Nov-20 04:14 PM @idmb yep that’s the set. Thank you so much! 05-Nov-20 04:43 PM Got about 5 hours on a SEM today (well dual beam, but I didn't use the fib)! 05-Nov-20 04:43 PM It was basically my first time getting in depth using one, after only ever really using a FIB before. 05-Nov-20 04:43 PM Pretty much the same experience, but the specimen doesn't disappear! 05-Nov-20 04:43 PM Was good confirmation that I'm not a terrible FIB microscopist 05-Nov-20 09:22 PM every second tick is 500ms 05-Nov-20 09:22 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screen_Shot_2020-11-05_at_9.22.19_PM-D5278.png 05-Nov-20 09:22 PM why is my chamber doing this lol 05-Nov-20 11:24 PM Who thinks it would be fun to make mri machine? How can I help out? 05-Nov-20 11:35 PM @adammunich Its not that hard to make MR machine, MRI is a bit more complicated - easiest is probably to start with Earth-field MRI. 05-Nov-20 11:48 PM Magnets aren't super expensive... would earth field be sharp enough to see inside your body? 05-Nov-20 11:50 PM "sharp enough"? 05-Nov-20 11:50 PM https://www.youtube.com/watch?v=7aRKAXD4dAg&list=PLD14D78BC61685BD7 This should be interesting to you 06-Nov-20 12:38 AM NMR gives me flashbacks 06-Nov-20 01:11 AM https://hyperfine.io/ 06-Nov-20 01:11 AM these guys use 64mT 06-Nov-20 01:14 AM looks at images These guys look way too happy for being in a hospital 06-Nov-20 01:17 AM They use permanent magnets! 06-Nov-20 01:29 AM I kind of don't trust those hyper-cool buzzword filled webpages with no technical specifications. 06-Nov-20 01:30 AM https://www.youtube.com/watch?v=LLmy5pohYus some guy showing it off at a tradeshow 06-Nov-20 01:31 AM I kind of don't trust those hyper-cool buzzword filled webpages with no technical specifications. @bkralik not just kind of... The Website looks about as trustworthy as a kickstarter for some kind of medicine 06-Nov-20 01:33 AM If you really want to build a MR, start studying, hmm, MR principles as Gigasquirrel suggested. Then you will find out why it is nontrivial to do MRI with permanent magnets and why using earth magnetic field is nice trick... 06-Nov-20 01:59 AM and why "real" MRTs use 3+ tesla 06-Nov-20 07:52 AM MRI time isn't even that limited, hospitals have lots of spare time with them when patients cancel. Huge amount of wasted downtime. Fixing that scheduling issue would probably do more than a janky DIY system. 06-Nov-20 12:47 PM Supposedly you can get half a tesla with copper wire solenoids, according to my google-fu. That seems like it would be enough for really good images with hyperfine's technology. I presume they are doing some sparse-sampling magic to get it to work at 64mT. 06-Nov-20 12:51 PM Half a tesla won't do much. That's like what, 30 MHz for HNMR? Good luck using that for analyzing small molecules. Let alone as an mri 06-Nov-20 12:53 PM Not even 06-Nov-20 12:53 PM More like 21 06-Nov-20 12:55 PM Larmor of a proton is 2.68*10⁸ Hz/T 06-Nov-20 04:25 PM I mean there are benchtop NMRs that use permanent magnet systems, but they wont ever go much over 50 MHz and I bet the magnets aren't cheap at all... 06-Nov-20 04:54 PM Hyperfine's system was on display at CES while I was there. Half a dozen journalists who were offered a magnet ride but something felt off all independently dropped me a line as I bartended to ask if this was kosher. The company was, accordingly, spanked extremely hard for testing on human subjects WITHOUT FDA APPROVAL OF THEIR PRODUCT. They weren't approved for medical trial much less trivial use on members of the public. 06-Nov-20 04:56 PM 06-Nov-20 04:56 PM For the fourth year in a row, I trigged an argument between the LVCC Authority and CES showrunners for "Are you people even remotely vetting what you're letting into this building, or are you just pocketing the checks and laughing all the way to the bank?" 06-Nov-20 06:22 PM as someone who has attended CES 06-Nov-20 06:22 PM the latter, ha 06-Nov-20 06:22 PM Unrelated: Should I lubricate KF gaskets? Or, is this ill-advised. 06-Nov-20 06:22 PM Well, not quite KF, but DN160 with claw clamps 06-Nov-20 06:27 PM only if you're sealing against awful surfaces 06-Nov-20 06:28 PM heh... how awful 06-Nov-20 06:29 PM try it without and see what happens 06-Nov-20 06:30 PM this machine will have lots of seals. if I am going to try to identify leaks later, would a volatile fluid introduced to a seal be a good way of identifying problem ones? 06-Nov-20 06:40 PM if the pressure is lower than 1E-5, yes. Just putting your favourite not-that-bad solvent on the sealed flange usually does the trick. If you have an RGA or hot ion gauges, you can also just spray some helium near each flange. It will either show up on the RGA or replace N2 on the ion gauge and be harder to ionize... Either way, a sudden pressure change due to something done on the outside of the flange = leak 07-Nov-20 07:53 PM If people need Supercon hangout, Some of us are hanging out on my Discord. Please DM for invite. 08-Nov-20 12:07 AM https://www.lesker.com/newweb/fluids/greases-silicone-dowcorning/dc976/ 08-Nov-20 12:07 AM 10^-4 torr seems kind of weak 08-Nov-20 09:01 AM That’s just the vapour pressure 08-Nov-20 09:01 AM If you have some in your chamber below that, it will evaporate away into the void 08-Nov-20 06:55 PM yeah that's what I am worried about 08-Nov-20 06:55 PM i'd like a grease / oil with something like, 10^-9 08-Nov-20 06:55 PM https://www.duniway.com/catalog/supplies/greases 08-Nov-20 09:11 PM what are you trying to do though 08-Nov-20 09:11 PM all these numbers only matter if you're price optimizing for a specific purpose 08-Nov-20 09:11 PM usually one thing is way over specced and you can relax 08-Nov-20 11:09 PM @adammunich There is no oil / grease with such low vapour pressure at 200degC. Apiezon H is also ~10^-2 Pa around that temperature. 08-Nov-20 11:20 PM what sort of properties do you want the grease or oil to have? 08-Nov-20 11:20 PM lubrication? sealing? heat transfer? insulation? ...struggling to come up with other uses of those substances off the top of my head 08-Nov-20 11:35 PM just something to lubricate the workings of my gate valves 08-Nov-20 11:35 PM and seal o rings 08-Nov-20 11:35 PM i just got some of the Apiezon L from ebay, it should do 08-Nov-20 11:45 PM X-ray photoelectron spectrometer. Well, maybe not this exact model but it’s very similar. Spherical main chamber, hemisphere dome at the top, and a rack full of electronics (a bit old) too. I have one at work to strip down, take apart and recycle. Aside from the good obvious stuff like the chambers, conflat windows, vacuum valves etc, would there be any particularly interesting parts that are good to salvage and keep? 08-Nov-20 11:45 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-1773C.jpg 08-Nov-20 11:45 PM I will get some photos of the real one when I start dismantling it 08-Nov-20 11:47 PM why dismantle it? 08-Nov-20 11:47 PM it's a nice tool as-is 08-Nov-20 11:47 PM if it's near california it could be re-homed at one of the local science centers 08-Nov-20 11:47 PM @a_quiet_scientist tools like these are much better in the world as-built than as a bunch of disjoint parts on a shelf 09-Nov-20 12:21 AM @a_quiet_scientist the detector itself would be pretty interesting, looks like a sector analyzer 09-Nov-20 12:21 AM and if you really don't need it a teardown would be interesting 09-Nov-20 01:39 AM I don’t think it’s in intact working order but it looks mostly intact, and we were basically told to strip it of anything we want or it’s going in the trash and I couldn’t let that happen 09-Nov-20 01:39 AM I think I can transport pieces of it but not the whole thing, it must weigh a ton 09-Nov-20 01:39 AM Probably a million bucks when it was new 09-Nov-20 01:05 PM @a_quiet_scientist where is it now? 09-Nov-20 01:58 PM @a_quiet_scientist A lot of those systems went in place in the last ~20 years with DOE money attached to them. If you find any DOE property tags on that system, make absolutely certain that this has been removed from the federal asset inventory before you start throwing things away and handing out parts to people. And then ask crankily why they didn't remove those tags if it had been removed from the inventory. 10-Nov-20 06:24 AM how do you all deal with safety during a bakeout? are you all ever concerned about heating strips falling off and causing a fire overnight? 10-Nov-20 06:36 AM kapton tape, lots of Al foil and bad, paranoid sleep 10-Nov-20 06:42 AM how i wish i could convince my employer with that 10-Nov-20 06:45 AM smoke Alarm in the room? 10-Nov-20 06:45 AM over temperature shutoff 10-Nov-20 06:45 AM isnt an over temperature shutoff kind of strange 10-Nov-20 06:45 AM youre basically using a on off controller on another controller 10-Nov-20 06:47 AM no I mean some melting fuse 20°C over the setpoint or something 10-Nov-20 06:47 AM permanent off 10-Nov-20 10:41 AM if you are leaving any kind of heating element unattended you definitely want a thermal fuse in the mix 10-Nov-20 10:41 AM you might ruin your heaters and chamber but you almost certainly will not burn your lab down 10-Nov-20 10:50 AM also consider hard limiting the output with a variac rather than trusting a temp controller to do everything 10-Nov-20 11:49 AM @vapicuno We have nightshifts during bakeout 10-Nov-20 11:49 AM (We have big machine, inductive 20 kW heating of main chamber, ~ 100 heating controllers for ports and ~30 another one for attached equipment...) 10-Nov-20 06:17 PM @funranium thanks. I’m in Australia remember. 10-Nov-20 06:17 PM @adammunich it’s in one of the labs in our building, not our lab, and they really want the lab empty for another PI to move in so everything must go 10-Nov-20 06:48 PM I had no idea you were in Australia. Mind your respective funding agencies. 10-Nov-20 06:56 PM Anyone got a fab/lab building construction white paper sort of thing? 10-Nov-20 06:56 PM I'm thinking stuff like raised floor for cabling and cooling lines below, chase behind cleanrooms for pumps and maybe electronics that have lots of crevices and possibly different cooling/heating requirements than the user side of the tool 10-Nov-20 06:56 PM Plenum design for above HEPA filters (and whatever better filteration methods there are) 10-Nov-20 06:58 PM get the highest ceilings you can afford 10-Nov-20 06:58 PM Looking at an 18ft metal building 10-Nov-20 06:58 PM 40*100 ft is what I'm currently thinking 10-Nov-20 06:59 PM If you're setting up a semi-permanent place from scratch 10-Nov-20 06:59 PM just every time you do something, either do it right or do it in a way that is so inconvenient you will have to re-do it sometime soon correctly 10-Nov-20 07:01 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/PXL_20201109_2018297502-DFF2B.jpg 10-Nov-20 07:01 PM @idmb Yeah that sounds like a good method 10-Nov-20 07:01 PM Also, things of question surround insulation of the building and/or the smaller inset rooms 10-Nov-20 07:11 PM Mind your paint for the clean room but I’m sure you’re aware of that already 10-Nov-20 07:20 PM man your writing looks like mine 10-Nov-20 07:20 PM if you put unistrut up anywhere, figure out the load bearing calcs ahead of time 10-Nov-20 07:20 PM when the system is simple and easy to measure / modify 10-Nov-20 07:28 PM @funranium thanks. I’m in Australia remember. @a_quiet_scientist I'll try to find someone deserving in australia... my heart was already broken once this year seeing CVD machines in a scrapyard, hopefully this can avoid the scrapyard 0_o 10-Nov-20 07:52 PM Well if I was building my dream lab with unlimited budget? - Cleanroom - Yellow room which is a part of the cleanroom, usually also a higher grade of cleanroom in addition to safe light - Quiet area, no vibration or loud footsteps or banging, this is important for things like EBL and AFM - Non-cleanroom wet lab, built with the capacity to meet BSL2 requirements in the construction parts so you have the capacity to do BSL2 work without big modifications even if you’re not likely to need it. The wet lab is not strictly a cleanroom but should still be fairly clean. - Wood work shop. Keep it well away from clean labs. - Metal shop - Electronics lab, divided into soldering type stuff on one bench and instrumentation stuff on another bench. - Two darkrooms, one wet and one dry. Wet darkroom for photography and PCBs etc, dry darkroom with optics benches. 10-Nov-20 07:52 PM - Physics lab (may double as the electronics lab) needs lots of AC power, maybe 3 phase, and an overhead load bearing beam for a block and tackle. Optical bench, and space for vacuum systems. 10-Nov-20 07:57 PM 3 phase is a must isn't it? 10-Nov-20 07:57 PM I've never been in a lab without it 10-Nov-20 08:02 PM Plumbing: Water to sinks in wet labs. If you’re really doing a pro job, consider centralised DI water distribution. Centralised cold water chiller for devices that need water cooling such as lasers and diff pumps in some cases. Distribution of compressed dry air or nitrogen with filters to remove water and oil and junk. Plumbing for vacuum exhausts from vacuum systems. Installation of fume hoods and fume hood ventilation plumbing. Earth leakage circuit protection and clear labelling and identification of circuits when you need to reset a breaker. Blacked out windows, or no windows, if required for laser safety, or safe light or darkroom needs. “Laser in use” / “Accelerator on” signs wired in, and door interlocks, if appropriate for your lab. Oxygen monitoring alarms and gas detection, if inert gases, cryogenics, toxic or flammable gases are used. Space to put proper flammable/hazmat chemical storage cabinets 10-Nov-20 08:19 PM I've had a dream lab before... the most important thing is having other people around to do fun stuff with 10-Nov-20 08:19 PM otherwise it's just a bunch of things on shelves 10-Nov-20 08:22 PM The things on shelves are supposed to be fun 10-Nov-20 08:25 PM A community of like minded people as long as they are good to work with, good attitude, and they are safe or can be taught safety, and they’re keen 10-Nov-20 08:25 PM And not too much bureaucracy or drama 10-Nov-20 08:25 PM It would be so good to have a serious vacuum engineering / microfabrication/ nanoscience / materials hackerspace, but really hard to fund and staff, and hackerspaces end up commonly being toxic dumpster fires 10-Nov-20 08:25 PM Got to have good culture 10-Nov-20 08:28 PM we have this to some extent for electronics and biology at sudo room & counter culture labs, respectively 10-Nov-20 08:28 PM https://www.counterculturelabs.org/ 10-Nov-20 08:28 PM no staff are paid. it turns out when you have expensive equipment no one touches it if they don't know how to use it 10-Nov-20 08:29 PM Bureaucracy does a lot of good when it’s navigable 10-Nov-20 08:29 PM even strangers who walk in, they don't know how to even turn stuff on let alone break it lol 10-Nov-20 08:30 PM “Fill out the injury report form, unless the pain of the form is worse than the injury” or something 10-Nov-20 10:04 PM @a_quiet_scientist thanks for all the great tips. They're all familiar but they weren't all in one place in the front of my head. 10-Nov-20 10:04 PM I've been looking at rural properties, mostly in light farm or timber communities... Pretty low density living areas (i.e. I want between 20-100 acres). 10-Nov-20 10:04 PM Mostly the shop and labs will be for me and my family. My 2 year old should be 6 or 8 in no time and I look forward to him being my apprentice/helper. 10-Nov-20 10:04 PM Bringing non family into the mix increases liability a LOT 10-Nov-20 10:04 PM With a 25 acre place I bid on yesterday, I was thinking the one barn near the road and away from the house might be able to be fixed up into some sort of science museum or center 10-Nov-20 10:04 PM Mayyybe with a classroom or something 10-Nov-20 10:04 PM Also re unused equipment, I just found this earlier today to legitimize that a bit (unless the article is fake) https://nesslabs.com/antilibrary 11-Nov-20 11:10 AM <𝓕ermion#6024> hey guys, under what condition will I contaminate my lines leading to a wet pump? When will I backstream? 11-Nov-20 11:10 AM <𝓕ermion#6024> suppose I have a turbo pump backed by an oil pump 11-Nov-20 11:10 AM <𝓕ermion#6024> what should I never do 11-Nov-20 11:10 AM <𝓕ermion#6024> assuming every line is broken by a valve and the power of each element can be controlled independently 11-Nov-20 11:10 AM <𝓕ermion#6024> like if I close the valve between my oil pump and turbo, turn on the oil pump, turn it off, and then open the valve, will something bad happen? that kind of thing. 11-Nov-20 11:10 AM <𝓕ermion#6024> I have experience with vacuum pumps but I came from a group with only dry pumps so I just want to make sure I don’t do anything stupid. 11-Nov-20 11:10 AM <𝓕ermion#6024> @idmb @Mezmorizor 11-Nov-20 11:13 AM Never open a valve between the oil pump and the line if the line is under vacuum but the pump side isn’t 11-Nov-20 11:13 AM The vacuum will suck oil down the line 11-Nov-20 11:13 AM Mez is oil backed oil afaik 11-Nov-20 11:13 AM We only used a rotary vane to back a turbo once 11-Nov-20 11:16 AM <𝓕ermion#6024> okay I see. 11-Nov-20 11:17 AM My neighbours wouldn’t lend me a turbo when I wanted to use it to pump a small chamber that had been rough pumped just once with a rotary vane 11-Nov-20 11:17 AM Unless I washed it and baked it 11-Nov-20 11:17 AM And they don’t even use their turbos for uhv, just -7 ish. 11-Nov-20 11:17 AM I don’t know that it matters that much, but that’s their vibes on this. 11-Nov-20 11:17 AM (And our neighbours loan us all sorts of $$ stuff) 11-Nov-20 11:17 AM I also remember reading something about how the oil is more of a problem if you’re at the ultimate pressure of the pumps? Like if your load is keeping it around -2 in the forevac it’s somehow better than if you’re pushing -4 with the pump... I’ll check if I can find that 11-Nov-20 11:17 AM Personally I only went oil-free because we’re looking at carbon, oxygen, nitrogen, and sulphur with the time of flight 11-Nov-20 11:17 AM So any mess in the <50 AMU range is disgusting. 11-Nov-20 11:20 AM <𝓕ermion#6024> well heh... we have a pump cart that has a safety valve on the turbo 11-Nov-20 11:20 AM <𝓕ermion#6024> if the power gets pulled, the turbo gets shut off from the chamber 11-Nov-20 11:20 AM <𝓕ermion#6024> but that just means that air is free to enter the roughing pump and backstream oil into the turbo?? 11-Nov-20 11:20 AM <𝓕ermion#6024> seems like the wrong move lol 11-Nov-20 11:23 AM No isolation on both sides of the turbo? 11-Nov-20 11:24 AM Lol our isolation valves are on the backs of the turbo, not the front 11-Nov-20 11:25 AM Yeah that is where I have seen them most often. Probably pretty simple to add a valve on the outlet of the turbo to also shut that down in case of power loss if the cart does not have one 11-Nov-20 11:25 AM They’re dirt cheap too 11-Nov-20 11:25 AM Couple KF clamps and wiring/air tubing 11-Nov-20 11:25 AM Someone was linking like $25 pneumatic KF valves 11-Nov-20 11:25 AM Yep that is what immediately popped into my head 11-Nov-20 11:25 AM And you don’t even need a local air supply 11-Nov-20 11:25 AM Because you can charge it (open it) then valve it off 11-Nov-20 11:26 AM I need to order new solenoids after mine got lost in transit due to the pandemic stuff 11-Nov-20 11:26 AM If you get the 110V AC ones, you can plug them in directly and charge them all, then in a power failure they all close and release air and won’t open again if the power comes back 11-Nov-20 11:26 AM No need for fancy switching relays or anything 11-Nov-20 11:27 AM <𝓕ermion#6024> huh that’s pretty nice. 11-Nov-20 11:27 AM Really easy to set up a small air reservoir for them because they use such a small air volume (for the KF16 size anyway) 11-Nov-20 11:27 AM I wouldn’t call it “nice” so much as trivial to set up 11-Nov-20 11:28 AM <𝓕ermion#6024> do you add a vent valve? 11-Nov-20 11:28 AM <𝓕ermion#6024> or do you just add isolation valves? 11-Nov-20 11:28 AM For what? 11-Nov-20 11:28 AM <𝓕ermion#6024> well ok, what valves do you add and where do you put them? 11-Nov-20 11:29 AM If you get the pneumatic valves you just get a solenoid that vents the air line when not powered 11-Nov-20 11:29 AM Think 2 position 3 ways was what I bought that never arrived...need to check that before reordering 11-Nov-20 11:29 AM <𝓕ermion#6024> no no I just mean where in the vacuum lines do you put the valves? 11-Nov-20 11:29 AM Oh 11-Nov-20 11:29 AM <𝓕ermion#6024> front of turbo? back of turbo? front of roughing pump? 11-Nov-20 11:29 AM I have mine right on the exhaust port of the turbo 11-Nov-20 11:30 AM @𝓕ermion Some RV pumps already have either electric NC shut off valve or just simple one-way valve on their inlet. In that case you can do almost whatever you want 11-Nov-20 11:30 AM So it cuts off the line from the roughing pump to that point 11-Nov-20 11:30 AM <𝓕ermion#6024> yeah maybe mine already has an isolation valve? 11-Nov-20 11:30 AM <𝓕ermion#6024> hmm 11-Nov-20 11:31 AM Mine are just arbitrarily placed in the line between backing pump and turbo 11-Nov-20 11:31 AM If the valve is between the turbo and whatever you are pumping as you originally described you will want one on the side of the turbo the roughing pump connects up to as well, imo 11-Nov-20 11:31 AM I guess it depends what all you’re trying to prevent 11-Nov-20 11:31 AM If you have a valve on both sides of the turbo, your turbo is as safe as it could ever need to be 11-Nov-20 11:32 AM <𝓕ermion#6024> yeah I suspect that in the configuration it’s in, the turbo is not safe. 11-Nov-20 11:34 AM Really though - most of the time most turbos will survive having their exhaust opened straight to atmosphere 11-Nov-20 11:34 AM It’s just “most of the time” is bad odds 11-Nov-20 11:34 AM Considering the cost. But the probability of exposing to atmosphere is also low 11-Nov-20 11:35 AM If it does not already have the isolation on the roughing side what is $50 for peace of mind 11-Nov-20 11:35 AM In a permanent configuration 11-Nov-20 11:35 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-28306.jpg 11-Nov-20 11:35 AM We just have these, they open fully for good conductance 11-Nov-20 11:35 AM The little solenoid valve controlling it is 120V Ac 11-Nov-20 11:35 AM So it’s just wired to a regular plug 11-Nov-20 11:35 AM And then it’s just like 50PSI of Air with AC to open them 11-Nov-20 11:35 AM And if AC shuts off, they vent their air and close 11-Nov-20 11:35 AM If the air supply is valved off manually, when Ac comes back on they don’t open again 11-Nov-20 11:35 AM But this also means you could charge and then valve off each valve in situ 11-Nov-20 11:35 AM Without needing a permanent air supply set up 11-Nov-20 11:35 AM Fully electrical ones like this work too, no air, but then you’d need a latching relay to have the “turn off and stay off” behaviour 11-Nov-20 11:35 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-04344.jpg 11-Nov-20 11:35 AM System is always something like this 11-Nov-20 11:35 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-F108D.jpg 11-Nov-20 11:35 AM The small line is so we can pre-pump the vacuum system or keep it pumped, while doing stuff with the main line 11-Nov-20 11:35 AM Since we share one huge roughing pump across two apparatus 11-Nov-20 11:35 AM https://www.ebay.ca/itm/MDC-Vacuum-Products-KAV-100-P-Pneumatic-Angle-Valve-HV-Series/153421752065?epid=1641521457&hash=item23b8a62701:g:dz0AAOSw8mtckS7G the valves are just something like that, but you need them to have the little solenoid valve on them too for easy setup 11-Nov-20 11:35 AM someone linked some at like $30 USD complete. they're very basic and easy to do maintenance on, so they'd have to be really badly damaged to be unusable. IIRC they're shaft seal, so there's no bellows to break either 11-Nov-20 11:56 AM https://www.ebay.com/p/803244870 11-Nov-20 11:56 AM $20 shipped 11-Nov-20 12:05 PM kf16 tho 11-Nov-20 12:05 PM mine are chunky kf40 11-Nov-20 12:05 PM You can do all sorts of things if you set them up to a PLC, like protect the turbo from overpressure and stuff. But it gets exponentially more painful to setup 11-Nov-20 12:05 PM but as a postdoc I guess that's your job 11-Nov-20 12:20 PM <𝓕ermion#6024> no my job is to wrap things in enough duct tape that they work 11-Nov-20 12:20 PM <𝓕ermion#6024> the PLC thing is for grad students hehe 11-Nov-20 12:20 PM <𝓕ermion#6024> I only got 3 years... gotta hustle lol 11-Nov-20 12:26 PM Catching up so I may/probably said redundant things, but the big one is never having the valve between the line and the oil pump open when the pump is off. We personally have a metal wool foreline trap on the oil pump and have a pneumatic valve attached to a pressure gauge that will trip a relay which closes the pneumatic valve and shuts down the turbo whenever the foreline gets to a certain pressure threshold (don't know it off the top of my head). We don't have an ultra clean chamber, you can definitely see a bit of the oil on the RGA/quadrupole/time of flight, but it's good enough for what we need at least. 11-Nov-20 12:26 PM I should also say this turbo is also attached to 2-3 diffusion pumped chambers that we isolate with differential pumping depending on the instrument, so I can't really say how much of the oil we see is is rotary vanes and how much is the diffusion pumps 11-Nov-20 12:31 PM We don't have an ultra clean chamber with your diff pump you probably have a top ten grossest chamber in the field tbh 11-Nov-20 12:31 PM it's way bigger than vilesov's isn't it? 11-Nov-20 12:34 PM I would be shocked if the new instrument doesn't have the biggest source chamber pump in the field 11-Nov-20 12:34 PM So yeah 11-Nov-20 12:34 PM Let me look up which one it is again 11-Nov-20 12:34 PM Varian HS-16 11-Nov-20 12:36 PM they get bigger though 11-Nov-20 12:36 PM Yeah 11-Nov-20 12:36 PM Varian has one that pumps ~75% faster 11-Nov-20 12:36 PM Though honestly we just have the Roger Miller experiment 11-Nov-20 12:36 PM And then we made the same idea bigger 11-Nov-20 12:36 PM More or less 11-Nov-20 12:36 PM https://www.antsalliance.com/pump/oil-diffusion/130-000-L-s-large-capacity-diffusion-pump.html 11-Nov-20 12:37 PM Jesus 11-Nov-20 12:37 PM And I also missed more of the Varian ones 11-Nov-20 12:37 PM We have a "baby" large diff pump 11-Nov-20 12:37 PM Which still makes the experiment like...15 feet tall 11-Nov-20 12:38 PM your diffusion pump isn't actually that great 11-Nov-20 12:38 PM the can only be mounted upright 11-Nov-20 12:38 PM so on a six way cross 11-Nov-20 12:38 PM Nah 11-Nov-20 12:38 PM you could have four 3000 L/s turbos 11-Nov-20 12:38 PM instead 11-Nov-20 12:39 PM The idea behind the diff pumps is that they're lower maintenance 11-Nov-20 12:39 PM The HS-16 is still a pain if it goes kablooey 11-Nov-20 12:39 PM But the others not so much 11-Nov-20 12:40 PM maintenance? 11-Nov-20 12:40 PM turbos last more than 1 grant cycle 11-Nov-20 12:40 PM that's all the matters isn't it 11-Nov-20 12:40 PM also gosh darn, my broken laser still gives me 2x as much energy as I can use 11-Nov-20 12:42 PM The idea is that this will last like 20 years and not just 3. Though by maintenance I more mean there's not a lot of things that can break 11-Nov-20 12:42 PM Basically just overheating 11-Nov-20 12:42 PM Also really hoping I didn't accidentally break the output coupler yesterday... 11-Nov-20 12:42 PM That coating they use is FRAGILE 11-Nov-20 12:43 PM I think turbos are more of a 10 +/- 5 years of continuous use thing 11-Nov-20 12:43 PM since it's not like we're spinning them up and down frequently 11-Nov-20 12:44 PM We do it semi often 11-Nov-20 12:44 PM You need to vent to go from normal-stark-zeeman 11-Nov-20 12:44 PM Which I know is bad 11-Nov-20 12:44 PM But I don't see how else you can do it 11-Nov-20 12:44 PM The stark especially doesn't have much room for error 11-Nov-20 12:45 PM valve in front of turbo ? 11-Nov-20 12:48 PM I think I would describe it as in front of, yeah 11-Nov-20 12:48 PM It's rotary vane-wool trap-valve-two turbos 11-Nov-20 12:51 PM but you shouldn't have to cycle the turbos 11-Nov-20 12:51 PM if you valve them off when you vent 11-Nov-20 12:56 PM Oh, it's not valved that way no 11-Nov-20 12:56 PM It's valved on the foreline 11-Nov-20 12:56 PM It's open to the chamber 11-Nov-20 12:56 PM So that would be how you'd do it...but it's not set up that way 11-Nov-20 03:21 PM Hey everyone! 11-Nov-20 03:21 PM Long time no see 11-Nov-20 03:24 PM Glad to see you back! 11-Nov-20 03:24 PM Glad to be back 11-Nov-20 03:24 PM Anyways I hear something about a few broken SEMs here 11-Nov-20 03:27 PM @george needs help, but apparently he's already asleep :v 11-Nov-20 03:28 PM Ah damn 11-Nov-20 03:28 PM Jeol 6300? 11-Nov-20 03:28 PM Aye 11-Nov-20 03:28 PM Cool 11-Nov-20 03:28 PM Can definitely help with that 11-Nov-20 03:28 PM I'm standing in front of one lol 11-Nov-20 03:29 PM I've pinged him, he should be back tomorrow 11-Nov-20 03:30 PM Sounds good 11-Nov-20 03:30 PM Any idea what the issue is? 11-Nov-20 05:38 PM I did some napkin math, It looks like you can make an MRI magnet without superconductors and it would take only about 5kW to run it. About as much as a clothes dryer. This assumes a 1 meter diameter magnet, 1 meter long, 1 tesla. 11-Nov-20 06:04 PM something about that sounds off 11-Nov-20 06:04 PM you could try running your numbers through something like http://www.femm.info/wiki/HomePage 11-Nov-20 06:04 PM I have used that in the past and had decent results 11-Nov-20 06:43 PM what's your bore size? and, is that including cooling? 11-Nov-20 06:44 PM also does that account for physical losses from having to actually wind the coil out of some material? 11-Nov-20 08:58 PM I screwed up my calculation you are right. 11-Nov-20 11:20 PM @adammunich Have you thought about field homogenity of such magnet? Because this is maybe biggest issue, we are trying to tell you many times... 11-Nov-20 11:40 PM @GigaSquirrel that big Glassman HV finally arrived today 11-Nov-20 11:40 PM Woah, finally! 11-Nov-20 11:40 PM after what, two months? 11-Nov-20 11:40 PM Yeah I guess the shipping and flights and stuff are limited due to COVID 11-Nov-20 11:41 PM angry mumbles 11-Nov-20 11:41 PM but I'm glad it's finally there, have fun with it 11-Nov-20 11:42 PM It took 6 weeks with express mail for a stein to make it from SFO to Brisbane. The flights to Australia are painfully limited. 11-Nov-20 11:42 PM I'm ok with stuff taking longer, esp. during a pandemic, don't get me wrong 11-Nov-20 11:42 PM my issue is that @a_quiet_scientist had to pay twice the shipping costs because DHL forces people at the moment to pay for premium shipping, because that's "faster" 11-Nov-20 11:42 PM without leaving a choice of "slower" shipping, or mentioning any timeframes 11-Nov-20 11:44 PM DHL is bad. It is known. 11-Nov-20 11:44 PM and that's the only thing we've got here, all the others either don't do international, or don't deal with individuals 11-Nov-20 11:44 PM but anyways, I hope you like the hvps, have fun with it and don't hurt yourself 11-Nov-20 11:45 PM without leaving a choice of "slower" shipping, or mentioning any timeframes @GigaSquirrel that sucks :/ 11-Nov-20 11:45 PM [shakes angry fist at Germany] DHL is nice in country I'm to gather. Ish. Or at least not particularly worse than FedEx. But internationally, wow, it's terrible to make UPS look good. 11-Nov-20 11:46 PM DHL here only gives me a set of flat rates to work with 11-Nov-20 11:46 PM DHL has been really slow for me too, been waiting for a box stuck in LA for 2 days now 11-Nov-20 11:47 PM so when I shipped my silicon wafers 11-Nov-20 11:47 PM $120+ was what I paid 11-Nov-20 11:47 PM AAAAAAAAAAAAAAAAAAAAA 11-Nov-20 11:47 PM honestly at that point 11-Nov-20 11:47 PM I could have just bought brand new wafers to ship to @N00N directly 11-Nov-20 11:48 PM DHL treated me really well last month actually 11-Nov-20 11:48 PM Overnight from taiwan when I paid for 5 day 11-Nov-20 11:49 PM I'm ok with stuff taking longer, esp. during a pandemic, don't get me wrong @GigaSquirrel also I guess it depends on what you're shipping and all 11-Nov-20 11:49 PM I know adafruit likes them over UPS for shipping out of the US 11-Nov-20 11:49 PM I had medicine shipments delayed for many months 11-Nov-20 11:49 PM UPS kept on fucking up customs 11-Nov-20 11:49 PM oof 11-Nov-20 11:49 PM until they decided that they'd just go with FedEx and reship to me 11-Nov-20 11:49 PM which arrived in less than a week 11-Nov-20 11:50 PM I think we can all agree that Amazon is worse than all of them though 11-Nov-20 11:50 PM I dunno 11-Nov-20 11:50 PM I rarely use Amazon 11-Nov-20 11:50 PM Good choice 11-Nov-20 11:51 PM I think the only thing I bought using Amazon was a DSP book that no where else had a copy of 11-Nov-20 11:51 PM I have a thermal camera coming right now and womp womp looks like the lost it 11-Nov-20 11:51 PM and then never used Amazon since 11-Nov-20 11:51 PM in any case - I don't want to imagine the shipping and handling costs of the stuff people deal with here 11-Nov-20 11:52 PM It could be worse, when I ordered tubes from russia they took 5 months to arrive 11-Nov-20 11:53 PM I would think a HVPS would be sizable enough to make shipping more expensive than the HVPS itself 11-Nov-20 11:53 PM especially if you had to go "premium" shipping 11-Nov-20 11:57 PM I have a thermal camera coming right now and womp womp looks like the lost it @AdamMcCombs what kind 11-Nov-20 11:57 PM Seek compact pro 11-Nov-20 11:58 PM i have a soft spot for thermal cameras 11-Nov-20 11:59 PM This will by my first that is actually mine 11-Nov-20 11:59 PM I've been using these to look at gasses 11-Nov-20 11:59 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/90420726495010690_fbc9e5aaf2ad45c99ddd3be0-F6554.png 11-Nov-20 11:59 PM https://www.youtube.com/watch?v=E0UKDZ_fW0E 12-Nov-20 08:43 AM <𝓕ermion#6024> @idmb @Mezmorizor thanks for the suggestions about the valves! This setup is really more for a mobile setup so charging the valves with air beforehand doesn't work super well as I have to move the cart around, but I'm sure there will be other situations where the air trick will come in super handy 12-Nov-20 08:43 AM <𝓕ermion#6024> if I wanted to do an air manifold kinda setup, I reckon Festo makes good manifolds right? 12-Nov-20 08:43 AM <𝓕ermion#6024> whose PLCs are good? 12-Nov-20 08:43 AM <𝓕ermion#6024> never played with PLCs but I'm kinda keen to 12-Nov-20 12:15 PM Hey @AdamMcCombs 12-Nov-20 12:15 PM I was just talking last night with a friend. Some industrial space opened up for rent and we are looking at seeing if we can get enough people in Chicago to do this. 12-Nov-20 12:15 PM We’re probably going to focus on the Leica S430 first as it did work, and it has a working EDX. 12-Nov-20 12:15 PM It definitely needs a new E-T scint. 12-Nov-20 12:15 PM And the Edwards rotary pump bit it. 12-Nov-20 12:15 PM I’d love to get a hold of an RGA or helium leak detector as the chamber can’t get below 1e-5 torr. 12-Nov-20 01:09 PM i'm curious what's the $ / sqft like in chicago 12-Nov-20 01:09 PM in the bay area the mean time to default for shared spaces is 5 years... landlords get antsy and do rent hikes / evictions then 12-Nov-20 01:31 PM I’m hearing $1200/1000 sf. 12-Nov-20 01:31 PM I could be wrong on that though. 12-Nov-20 02:53 PM To buy?? That's high for even here 12-Nov-20 02:55 PM He used the word rent 12-Nov-20 02:56 PM Oh wait I completely missed the /1000 bit 12-Nov-20 02:56 PM 1.2/sqft sounds like LA prices 12-Nov-20 02:57 PM I've been getting quotes on metal buildings this week... 4000 sq ft is like $59k not including site prep and concrete (which is at least an extra 13k or so, not including labor to finish it) 12-Nov-20 02:57 PM Insulation for a building that size would also be like $11k for r19 I think 12-Nov-20 02:57 PM So not including the concrete finish labor, that's around $20.75/ sq ft 12-Nov-20 03:00 PM 59k for 4ksqft boi sign me up 12-Nov-20 03:00 PM sounds like a deal 12-Nov-20 03:00 PM That's what I've been trying to convince the wife of ;) 12-Nov-20 03:00 PM She wants me to get a half size to start, and I'm like * sad face * 12-Nov-20 03:01 PM 59k buys you a boat slip here.... maaayybe 12-Nov-20 03:01 PM pour the slab for 4ksqft and start there 12-Nov-20 03:01 PM Well these metal buildings seem like national prices 12-Nov-20 03:01 PM The land cost is much more variable it seems 12-Nov-20 03:01 PM As well as concrete material costs 12-Nov-20 03:03 PM land is indeed variable. i was going to buy a farm earlier this year but someone in the group front-ran it 12-Nov-20 03:03 PM rip 12-Nov-20 03:05 PM Front ran? 12-Nov-20 03:09 PM buy it outside of the group with intent to resell / release 12-Nov-20 07:53 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/img_thermal_1605239340674-5326B.jpg 12-Nov-20 07:53 PM Ayyyy thermal camera 12-Nov-20 07:53 PM I'm not going to say how much time I spent around the house today looking at everything with it 12-Nov-20 09:31 PM Joined the server. 12-Nov-20 11:06 PM Welcome! 12-Nov-20 11:23 PM @nmz787 I just bought a 2000 foot building kit. I have to comp the roof and stucco the sides so I went rigid metal frame. If I could have done metal roof and sides in that neighborhood I would have gone with a miracle truss type building. You can also look into pole barn type construction if you are not in earthquake country. If you use a contractor expect to pay like $15 or so a foot for foundation and erection costs depending on location. 12-Nov-20 11:23 PM The quote for my building no siding or roof for 2000 was 25K and if I wanted couregated sides and roof it really would have not added much. I plan on building it myself/hire subcontractors cause I have no deadline to get it done and it’s on property I already own. 13-Nov-20 02:52 AM Hadn't heard of those different "system" names, I'm in occasional earthquake country (near Portland OR) but pole barns are pretty common. I did just read a day or two ago about flexing of the building skin/frame and cracking internal finish things like drywall/joint compound 13-Nov-20 02:52 AM The few quotes I've got so far have been from local companies and included erection, but required the foundation/piers/footings to already be in place 13-Nov-20 06:45 PM The building I am buying is coming from Sandy Oregon. Web Steel Structures northwest. 13-Nov-20 06:45 PM They can do the entire plan for you including foundation. 13-Nov-20 06:45 PM They can either sell it to you as a kit or find you somebody to build it for a reasonable price. 13-Nov-20 09:07 PM The Discord emoji you didn’t know you needed 13-Nov-20 09:07 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-CC0EC.jpg 13-Nov-20 09:13 PM Yeah we need this 13-Nov-20 09:16 PM Agreed 14-Nov-20 08:44 AM <𝓕ermion#6024> What server is that from? 14-Nov-20 06:18 PM I don’t know, someone tweeted it. 16-Nov-20 12:08 PM how vacuum compatible is FR4? 16-Nov-20 12:08 PM I found numbers like 10^-9 mbar*l/s *cm² 16-Nov-20 12:08 PM can anyone confirm that? 16-Nov-20 12:08 PM plus I'd imagine that big copper planes might slow down outgassing 16-Nov-20 12:19 PM not sure how helpful the info is but the nasa materials outgassing info database says 0.18-0.28% total mass lost, 0.01% collected volatile condensable material, 0.08-0.12% water vapor regained for FR4 pcb materials. https://outgassing.nasa.gov/index.cgi 16-Nov-20 12:46 PM I am not sure about FR4, but G10 (FR4 without flame retardnts) is widely used in cryostats (as spacers or as lamination of coils). So I would say it is fine... 16-Nov-20 12:49 PM I am thinking about some structural parts in vacuum from FR4 16-Nov-20 12:49 PM also blind / soldered shut vias as feedthroughs, lol 16-Nov-20 02:29 PM copper clad board would make a fine feedthrough 16-Nov-20 03:49 PM We routinely put heaps of standard PCBs inside E-4 Torr systems and it doesn’t hurt anything. How low are you trying to go? 16-Nov-20 03:55 PM oh yeah nothing much should matter even down to 1E-6 if you're continually pumping with even a small turbo 16-Nov-20 03:55 PM epoxy, hot glue... 16-Nov-20 04:16 PM @GigaSquirrel I designed stuff that went into a vacuum chamber on normal FR4 and it was fine 16-Nov-20 04:16 PM Initial pumpdown with those is ofc always a bit of a chore 16-Nov-20 04:16 PM And we did make our own feedthroughs with PCB. 16-Nov-20 04:16 PM Because we needed 6x 100pins for stuff 16-Nov-20 04:16 PM And that stuff pumped reliably down to 10^-8 mBar like a champ 16-Nov-20 04:22 PM How did you seal the pins against the FR4? 16-Nov-20 05:08 PM Would I be going to hell if I make a screwdriver rack which is a デーモンコア model with a bunch of screwdriver holes angled in around the bottom of the tamper? 16-Nov-20 05:08 PM My prof is like “just make anything and slather TorrSeal on it” 16-Nov-20 05:08 PM What’s the best way to clean gunky aluminium SEM stubs? I will probably just soak in acetone and ultrasonic for a while in acetone. 16-Nov-20 05:08 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-4E796.jpg 16-Nov-20 05:20 PM @analogmultiplizierer Cast epoxy 16-Nov-20 05:20 PM It was some stycast or something 16-Nov-20 05:20 PM The chambers ware custom anyway so we had them machined so that we could just plop in a board and then cast some epoxy on it 16-Nov-20 05:20 PM And the geometry at the hole was such that there ware low stresses on the epoxy 16-Nov-20 05:20 PM because 0th gen and some 1st gen versions had to be torrsealed in the field :D 16-Nov-20 05:37 PM Interesting. Thanks for sharing! 16-Nov-20 06:33 PM @a_quiet_scientist with my carbon tape, ethanol cleans up the residue great 16-Nov-20 07:29 PM Random rant: The GHS system for hazardous chemical labelling is so stupid. What’s the point of it? It contains less information. And the existing UN placard system was pretty much a consistent international standard. Like for example you have a flammable symbol, but that could be class 2.1, 3, 4.1, 4.2, 4.3, 5.2, but you don’t know anything at a glance without delving into the fine print. It’s stupid to me IMHO. 16-Nov-20 07:35 PM It's trying to do too many things at once. It's trying to be DOT placards, NFPA diamond, and more all once. Your complaint is one more for the chorus. 16-Nov-20 09:06 PM And the chronic health symbol has become a sort of meaningless worldwide Proposition 65. 16-Nov-20 09:49 PM @funranium who is the person mentioned on Twitter who burned the Melty the Bear shirt? 17-Nov-20 12:03 AM ...they did what?! 17-Nov-20 12:45 AM anyone know where to buy the banjo bolt + quick connect fitting used on VAT valves? 17-Nov-20 12:45 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/uPdHkK_L1MlKwYQwJZF8ZOlY7V_GA2nBcQSGAB76ld-BEFE3.png 17-Nov-20 03:21 AM Can you identify the thread spec? Generic banjo fittings are commonly available in the automotive / racing industry 17-Nov-20 03:21 AM I know the ones on Pfeiffer diaphragm pumps look pretty similar too 17-Nov-20 09:06 AM Couldn’t tell ya @a_quiet_scientist. If Katie feels like sharing she will but I suspect she’d like them to die in a fire of isolation. 17-Nov-20 09:37 AM Those damn pheiffer things. 17-Nov-20 09:37 AM Thank god I could go two stories up and bother the local reseller when I needed fittings at that job :D 17-Nov-20 09:37 AM "plz I need some new fittings that fit this port on this turbo I have" 17-Nov-20 09:37 AM When re-purposing old prototypes to become new test benches :D 17-Nov-20 09:37 AM Their office was half office half storage :D 17-Nov-20 11:48 AM Can you identify the thread spec? Generic banjo fittings are commonly available in the automotive / racing industry @a_quiet_scientist 3/8-32 UNEF 17-Nov-20 03:23 PM @idmb a while ago you mentioned a single constriction in vac line, sort of like an aperture, didn't slow pumping down as much as a length of pipe the same diameter as the aperture 17-Nov-20 03:23 PM Any keywords I can use to search this? 17-Nov-20 03:23 PM Apparently there's a similar effect with nanopores and their ionic current... An aperture/nanopore restricts current flow less than a "tunnel"/nanotube/nanopipe 17-Nov-20 03:44 PM @nmz787 In molecular flow, when gas molecules just travel in straight lines until they strike the wall, a tube would limit the range of angles from which a particle can go through the restriction, whereas if you had a hole cut out in a thin wall, essentially all molecules with any entry angle can go through 17-Nov-20 03:45 PM the "building scientific apparatus" book 17-Nov-20 03:45 PM it discusses apertures in both limits, and conductance of tubes in both limits 17-Nov-20 03:45 PM A tube is the way to go for differential pumping 17-Nov-20 03:46 PM https://www2.chemistry.msu.edu/courses/cem988Nuclear/lectures/Chem988_S09-Vac.pdf 17-Nov-20 03:46 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-8709D.png 17-Nov-20 03:46 PM also just got a fun facebook message 17-Nov-20 03:46 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-5F904.png 17-Nov-20 03:50 PM Oh no, is this some poor undergrad? 17-Nov-20 03:52 PM oh no 17-Nov-20 03:53 PM it's a biotech grad student 17-Nov-20 03:53 PM he wired it without a schematic 17-Nov-20 03:53 PM without realizing that if you do it wrong it sprays oil 17-Nov-20 03:59 PM Rotary vane? 17-Nov-20 03:59 PM they sure spray oil, when the motor spins in the wrong direction, but they wouldn't explode then afaik 17-Nov-20 04:01 PM I think it is likely that the anti-suck back valve exploded when under pressure? 17-Nov-20 04:03 PM A long time ago I witnessed a rotary vane pump with a large closed valve connected to it's outtake. The pump had built a lot of pressure and eventually it's oil window shattered, blowing oil mist and shrapnell into the room. 17-Nov-20 04:05 PM so his summary is he ran it backwards, it sprayed oil everywhere 17-Nov-20 04:05 PM then fixed the wiring, and when it ran forwards the gas ballast shot off 17-Nov-20 04:05 PM the knob for that 17-Nov-20 04:06 PM I think it is likely that the anti-suck back valve exploded when under pressure? @Mason_Yu I think the pump didn't build up a lot of pressure with the motor spinning backwards, unless a chamber was connected to it's intake port 17-Nov-20 04:06 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-1EFF3.png 17-Nov-20 04:06 PM number 5 came off 17-Nov-20 04:06 PM A long time ago I witnessed a rotary vane pump with a large closed valve connected to it's outtake. The pump had built a lot of pressure and eventually it's oil window shattered, blowing oil mist and shrapnell into the room. @analogmultiplizierer my iGX600L specifies up to 7 bar of outlet pressure if you cap it off. Scary stuff 17-Nov-20 04:08 PM I guess it depends on the specific construction of the anti-suck back valve. On the Welch direct drive pump I took apart, it is very much a 1-way valve 17-Nov-20 04:09 PM my iGX600L specifies up to 7 bar of outlet pressure if you cap it off. Scary stuff @idmb Yep totally scary. If i recall correctly it even blew metal shrapnell. It could have seriously hurt someone 17-Nov-20 04:10 PM Any ideas what was wrong such that the ballast adjustment thing popped off? 17-Nov-20 04:10 PM this thing 17-Nov-20 04:10 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Alcatel-2063-Gas-Knob-1-054219-21DC3.png 17-Nov-20 04:10 PM The gas ballast is under pressure, that cap just seals against a hole on the inside right? 17-Nov-20 04:11 PM this thing with threads doesn't seem to have a mated part ? 17-Nov-20 04:11 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Alcatel-2063-Gas-Knob-2-054219-99C9D.png 17-Nov-20 04:11 PM Do you think running it backwards messed up the one way valve, and that's why this popped off? 17-Nov-20 04:14 PM The gas ballast is under pressure, that cap just seals against a hole on the inside right? @Mason_Yu If I read idmb correctly it blew off when the pump was wired correctly. If I understand things right though, the gas ballast valve should seal agains a vacuum if the pump operates correctly 17-Nov-20 04:14 PM this is from the manual 17-Nov-20 04:14 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-DD739.png 17-Nov-20 04:17 PM Well if you run the pump in reverse and pressurize the pump stator before the anti-suck back valve, and then the anti-suck back valve is suddenly opened because the pump is running in the right direction again, that pressurized air is not only going to exhaust through the pump, it may go through the gas ballast inlet too 17-Nov-20 04:17 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/gas-ballast-assembly-lg-2-1-7E0E0.png 17-Nov-20 04:18 PM it wasn't sudden, because he had to rewire the pump 17-Nov-20 04:19 PM I meant when the pump is restarted in the right direction 17-Nov-20 04:19 PM You might want to check that one-way valve. It may not be designed to handle pressure much higher than atmosphere. Theoretically if it did its job perfectly, no gas should be coming out of the gas ballast inlet 17-Nov-20 04:27 PM Yeah, that's what I've told him to check 17-Nov-20 04:27 PM And told him that despite the mess, he should not cover the inlet or outlet ports yet. 17-Nov-20 04:28 PM Well he better have more sand or whatever it is that you use to clean up oil spills 17-Nov-20 04:28 PM oil absorbent pads 17-Nov-20 05:25 PM My vote is for damaged anti-suck back valve causing backpressure that blew the gas ballast thing off 17-Nov-20 05:25 PM Unless he did not actually rewire it correctly the second time and skipped mentioning that 17-Nov-20 05:25 PM Less bad but also possible would be that the gas ballast cap came off after it was rewired properly just as a latent overlooked issue from the initial reverse running 18-Nov-20 01:33 PM um 18-Nov-20 01:33 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-CB19F.png 18-Nov-20 01:36 PM Crazy 18-Nov-20 01:36 PM Flame throwers usually throw... Flames, not smoke 18-Nov-20 03:17 PM oil mist from the outlet? 18-Nov-20 04:42 PM This person sounds like a danger to themselves AND others 18-Nov-20 04:42 PM Hopefully it is just oil mist...but "shooting smoke like a flame thrower" sounds really really unhealthy for your lungs to be near 18-Nov-20 05:53 PM What in the hell is happening with this undergrad? Is he using a cursed soul centrifuge without enough blood or something? 18-Nov-20 06:04 PM I think he's actually a graduated grad student now 18-Nov-20 06:04 PM not from physics though!!! 18-Nov-20 07:30 PM So are they just letting the pump run on straight air? 18-Nov-20 07:30 PM It kinda sounds like they just over filled the oil 18-Nov-20 07:32 PM Probably 18-Nov-20 08:12 PM funny enough atomized oil does not burn 18-Nov-20 08:12 PM i was unable to burn atomized gasoline either 18-Nov-20 09:08 PM I've seen the "smoke" coming out of a rotary pump before but that was from a diffusion pump fire 18-Nov-20 11:53 PM This is why it’s eventually my goal to own vacuum systems that are only turbo drag pumps with diaphragm backing pumps. Oil is just horrible and cursed 18-Nov-20 11:54 PM I completely agree 18-Nov-20 11:54 PM In this case an o ring on a butterfly valve failed about 5 minutes after a vented my SEM for a sample exchange 18-Nov-20 11:54 PM Dumped atmosphere into hot dif pump 19-Nov-20 04:11 AM Argh a diff fluid change isn’t cheap 19-Nov-20 04:35 AM I often come across high voltage supply modules like this (OEM ones inside mass spectrometers and such) and it’s really hard to find any datasheets or reverse engineer the interface pinout. 19-Nov-20 04:35 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-8D7C1.jpg 19-Nov-20 04:35 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image1-52848.jpg 19-Nov-20 07:39 AM What are these actually called? I’m trying to find one to plug into a Glassman but they both seem too short to mate at the bottom of the hole 19-Nov-20 07:39 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-0FE78.jpg 19-Nov-20 07:40 AM aren't they PL259? 19-Nov-20 07:40 AM Looks like GES HV connectors to me. 19-Nov-20 07:41 AM oh the glasman is definitely PL 19-Nov-20 07:41 AM The higher the voltage, the longer the insulator, so you can't plug a lower voltage connector into a higher voltage one 19-Nov-20 07:41 AM Maybe it's the GES HSB series iirc? 19-Nov-20 07:41 AM Probably rated for 30 kV to 40 kV 19-Nov-20 07:41 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-9A003.png 19-Nov-20 07:43 AM just get a PL connector, break out the dielectric and inner connector and use the cables dielectric as shaft 19-Nov-20 07:43 AM that's how I did it 19-Nov-20 07:43 AM length isn't critical, as there's a spring on the end 19-Nov-20 08:28 AM Yeah, just stripping a cable correctly and shoving it in is a fairly common way to replace those... -_- 19-Nov-20 08:39 AM speaking of which, my 20kV (actually 30kV but soft limited to 20kV because SHV-20 was too nice to ignore) supplies seem to work nicely 19-Nov-20 08:46 AM Replace those? I've seen that in production on FEI stuff. 19-Nov-20 08:53 AM The supplies just come with bare cable 19-Nov-20 08:53 AM You wire them in your own chassis to whatever connector you want 19-Nov-20 08:56 AM Spellman 60 kV connector, it's just using the cable dielectric too but they were nice enough to solder on a cap for good connection 19-Nov-20 08:56 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20201119_105446-B3E16.jpg 19-Nov-20 08:57 AM Yeah... I prefer the obviousness of SHV 19-Nov-20 09:00 AM see, 'told ya 20-Nov-20 12:40 AM That story of the UK person with 2 tonnes of sodium metal in their home garage... And after the initial explosion the fire department put water on it, because of course they did, no signs, no labelling or anything. 20-Nov-20 12:40 AM https://www.birminghammail.co.uk/news/midlands-news/full-cost-handsworth-chemical-explosion-19302496.amp? 20-Nov-20 12:43 AM This server is just full of cursed content tonight 20-Nov-20 12:44 AM All your chemicals at home should be carefully labelled and documented, of course! Peroxide test your ether, and ask how much sodium you really actually need. 20-Nov-20 12:44 AM eeeeek 20-Nov-20 12:45 AM thought to be the greatest amount of sodium in its metallic form in Western Europe. 20-Nov-20 12:45 AM Surprisingly cheap to clean, really 20-Nov-20 12:45 AM When you consider many basic car crashes cost more than that in damages 20-Nov-20 12:47 AM The explosion was described at the time as like a "medium-sized firework display". 20-Nov-20 12:47 AM lol 20-Nov-20 12:47 AM Its ok it was only a medium sized firework display 20-Nov-20 12:47 AM If it were a large one we would be in trouble 20-Nov-20 05:24 AM Quality news site 20-Nov-20 05:24 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_20201120-142339-EB7EA.png 20-Nov-20 08:03 AM Can I get a big oof? 20-Nov-20 08:03 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/61-1IQRIwOL-7508D.png 20-Nov-20 08:31 AM I was very pleased with the sheer number of people that sent that news story to me. My #brand is strong. 20-Nov-20 08:35 AM I thought Derek Lowe would like it too 20-Nov-20 10:17 AM Back in the old days we would roll drums like that into lakes! 21-Nov-20 12:14 PM Does anyone here have experience with 18 meg water systems? 21-Nov-20 12:15 PM Tiny bit 21-Nov-20 12:21 PM So my use case is occasionally needing several gallons for some extreme ultra high vacuum applications, but I know a lot of systems don't like to be put into to shut down regularly. Any ideas of products that would be good for a use case like this? 21-Nov-20 12:21 PM I know there is a lot of bench top units out there, just curios if anyone has specific recommendations or gotchas to look for. 21-Nov-20 12:30 PM I haven’t run into any issues with the system being off or at the least on standby the overwhelming majority of the time 21-Nov-20 12:30 PM Can remember what we’re using though 21-Nov-20 12:30 PM And it could just be I missed that bit of instruction 21-Nov-20 12:35 PM I've only used 18 MOhm water filters in university/pro labs... Not sure they count for low use cases 21-Nov-20 12:35 PM I don't immediately see a reason why they'd dislike being shutdown, but I could see the tube/pipe coming FROM the filter potentially being crept into by organisms, from the opening to the room 21-Nov-20 05:05 PM If you don’t want to buy a MilliQ system and you only need small amounts maybe you could find someone who has one at a university etc and get some water from it. I don’t have any real experience to answer your question sorry. 21-Nov-20 05:05 PM It’s different for different applications, eg. the bio/pharma people need endotoxins out, sterility, etc, semiconductor people need all the Na+ out and all particles and pretty much everything else, trace metal analysis you want all the trace metals really out, so the systems tend to be slightly different for different jobs. 21-Nov-20 05:05 PM They say 18M water is corrosive because it “wants” ions in it, but I suspect that’s an urban legend. 21-Nov-20 08:03 PM I’ve heard of it destroying certain plastics over time from someone who used around 50 gallons of it for a muon detector 21-Nov-20 08:03 PM And it sure as heck tastes weird to drink 21-Nov-20 11:02 PM It’s a shame this is broken because it would be a lovely tube for an ICP deuteron source. 21-Nov-20 11:02 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-E3317.jpg 21-Nov-20 11:09 PM I believe this will be one of, if not the most powerful deuteron sources in the world. A 200 kW helicon plasma source for testing first wall materials of Tokamaks 21-Nov-20 11:09 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image-E8D68.png 21-Nov-20 11:09 PM Silicon nitride and aluminum nitride are very interesting materials for these types of tubes 21-Nov-20 11:09 PM Both are much tougher than quartz, or so I've been told 22-Nov-20 01:48 AM Did someone here recently post a link to an RF power supply paper for driving ion traps? I can’t find it now. 22-Nov-20 04:19 AM https://aip.scitation.org/doi/10.1063/1.2884148 Found it 22-Nov-20 04:19 AM I wonder if that can be used for driving a RGA or basic quadrupole mass spectrometer 22-Nov-20 04:19 AM The frequency can be kept constant, say 1 MHz or whatever the system is resonant at, the circuit controls the RF magnitude and bias tee circuits would need to be added to provide the adjustable DC bias component to the rods. 23-Nov-20 07:09 AM Joined the server. 23-Nov-20 07:54 AM Welcome! 25-Nov-20 07:41 AM @AdamMcCombs I have a MilliQ system,. You can have all the DI water you want. 26-Nov-20 03:59 PM So I want to swap my diff pump on my SEM to a turbo... I've got a V80 turbo of unknown health (it spins freely, but I need to clean it and get some new bearing oil) and also I think it's a conflat connection... While my diff pump is ??? 26-Nov-20 03:59 PM Sooo, what's a recommended approach to making an adapter? 26-Nov-20 03:59 PM I assume I'll need one of those rubber shock absorber bellows things 26-Nov-20 03:59 PM But like, I guess I'll need to have an adapter machined 26-Nov-20 04:00 PM recommended approach = identify the flange and buy what you need 26-Nov-20 04:00 PM But what should I start with to machine on? 26-Nov-20 04:00 PM Hmm 26-Nov-20 04:00 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20201126_160102-D7B3F.jpg 26-Nov-20 04:00 PM That's one of the spare diff pumps 26-Nov-20 04:05 PM approx OD? 26-Nov-20 04:07 PM 6 and 5/8 inches 26-Nov-20 04:07 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20201126_160800-C6256.jpg 26-Nov-20 04:11 PM OD aside, do the bolt hole placements line up with ASA 6"? https://www.lesker.com/newweb/flanges/flanges_asa.cfm?pgid=flat1 26-Nov-20 07:36 PM Joined the server. 27-Nov-20 02:56 AM hi 27-Nov-20 02:56 AM are LCP uhv compatible? 27-Nov-20 02:56 AM LCPs like sumitomos sumikasuper 27-Nov-20 02:49 PM Only sumitomo I know is a tire company 27-Nov-20 02:49 PM @idmb looks like it, but I need to get my caliper and check 27-Nov-20 02:49 PM @N00N only LCP I know is made by Ruger... And I'm guessing the oils would make them not so UHV friendly 27-Nov-20 02:50 PM I am kind of confused by your pump's flange 27-Nov-20 02:50 PM it looks like the middle tube protrudes 27-Nov-20 02:51 PM Yes 27-Nov-20 02:51 PM and there's bolts / grooves where an O ring could have gone 27-Nov-20 02:51 PM Hmm, I don't think there's a groove 27-Nov-20 02:51 PM I see what you mean 27-Nov-20 02:51 PM ASA flanges come in both grooved and flat styles 27-Nov-20 02:51 PM But I don't recall the o ring being there 27-Nov-20 02:51 PM do you have whatever this mates to? 27-Nov-20 02:52 PM I need to take off the current diff pump to at least remove the silicone oil I installed, since i learned after that's a no no for microscopes 27-Nov-20 02:52 PM Yeah the other side is my SEM 27-Nov-20 02:52 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMAG0022-21DE7.jpg 27-Nov-20 02:52 PM I apparently forgot to take, or lost, pictures of when I took it off and cleaned it 27-Nov-20 02:52 PM But you can see it bolts to a chiller baffle 27-Nov-20 03:02 PM @nmz787 It's possible that the water-cooled baffle has a standardized flange (most likely ASA) on it 27-Nov-20 03:02 PM But on the diffusion pump itself, I've found mine has something that looks really like ASA but is metric and doesn't match the bolt pattern exactly 27-Nov-20 03:02 PM To adapt mine to a turbo, I was fortunate enough to have a valve box that has studs at the right positions so I can use them for ISO160-K clamps 27-Nov-20 03:13 PM Hmm 27-Nov-20 03:14 PM The important flange is what the water-cooled baffle mounts to (likely your valve box). If it is a standard flange, there should be adaptors for it, but if not, you might get away with some custom toe-clamps 27-Nov-20 03:16 PM Well I bought a turbo controller this week, and have some iso clamps 27-Nov-20 03:16 PM So I guess it's time to pull the diff pump and baffle off 27-Nov-20 03:16 PM I think I'll be a lot more inclined to put the sem back together and debug any running issues without the whole chiller requirement 27-Nov-20 03:17 PM I do have a second ISO100 vibration isolation flange 27-Nov-20 03:17 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20201127_171718-5090A.jpg 27-Nov-20 03:18 PM Like, for sale/trade? 27-Nov-20 03:18 PM Or just have it for spare? 27-Nov-20 03:18 PM For sale/trade, if it fits your pump 27-Nov-20 03:19 PM Ok cool, I've got some iso100 thing here to compare with 27-Nov-20 03:19 PM i think iso100 to kf40 or something 27-Nov-20 03:19 PM And maybe a iso100 weldable flange 27-Nov-20 03:23 PM You have a welder right? Then welding a flange onto the valve box might be an option too, it will be better than using a few clamps to replace bolts and nuts, especially if you plan to hang your turbo in the air 27-Nov-20 03:25 PM Yep got a tig this summer... Haven't done any stainless practice 27-Nov-20 03:25 PM Normal steel seemed easy enough, sheet aluminum was bad... 27-Nov-20 03:25 PM Welding onto the baffle might be an OK idea too, just so I could still easily separate things in case I messed the welding up 27-Nov-20 03:28 PM It looks like your baffle has some through-holes for the bolts that secure the diffusion pump flange, so your weld would have to be on the inside of that, you might not have enough space 27-Nov-20 03:28 PM Also, keeping the baffle in place just kills a lot of pumping speed 27-Nov-20 03:28 PM And in my case, it simply won't fit lol 27-Nov-20 03:29 PM Yeah with the vibration damper vertical space could be a challenge 27-Nov-20 03:31 PM My valve box was small enough to be easily detachable from the chamber, yours look a bit bigger... 27-Nov-20 03:31 PM Ok well I guess I need to tear into it this weekend 28-Nov-20 01:09 AM @nmz787 hm k ️ 28-Nov-20 01:09 AM hopefully I will find some connectors with ptfe as a dielectric 28-Nov-20 10:55 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Screenshot_20201128-105500-50705.png 28-Nov-20 10:55 AM @N00N 28-Nov-20 11:09 AM https://www.sumitomo-chem.co.jp/sep/english/products/lcp/ 28-Nov-20 11:09 AM Interesting stuff 28-Nov-20 03:40 PM Is there a GoTo reference for repairing turbo pumps? [mine is not broken, just looking more into turbo-shaft motors and curious on available literature as it would pertain to us] 28-Nov-20 03:44 PM I don't think there is one go-to reference for the mechanical construction and maintenance, and turbomolecular pump construction is quite different from the turboshaft motors (the kind that makes power) that you are interested in 28-Nov-20 03:45 PM Sure, I dont think I have much desire to actually make/construct a turboshaft.. may be interesting to see how good of a pump could be home made though 28-Nov-20 03:45 PM or the idea of getting a broken pump and repairing it on the cheap 28-Nov-20 03:46 PM Making a drag pump is easier at home, although of course it still requires very high precision, at least you don't need a 5-axis CNC mill for the blades 28-Nov-20 03:47 PM yeah, I've been thinking some on that 28-Nov-20 03:47 PM maybe once I get access to my 3d pantograph machine it could copy a 3d printed model, well enough 28-Nov-20 03:48 PM And as for broken turbos (that are not a bowl of blade salad), most likely failures are on the bearings, which are hard to find cheap replacements for, especially the magnetic ones 28-Nov-20 03:48 PM A 3D printed model? 28-Nov-20 03:48 PM like a plastic filament printed version 28-Nov-20 03:48 PM which is then traced/copied from a pantograph 28-Nov-20 03:49 PM You'd just need good skill on a good lathe for a drag pump 28-Nov-20 03:49 PM ie, do away with a 5 axis mill if what you have works 28-Nov-20 03:49 PM Oh you're thinking about making blades 28-Nov-20 03:49 PM that seems like some of the most complicated parts, so yeah 28-Nov-20 03:49 PM geometry wise 28-Nov-20 03:50 PM Sounds like a huge amount of work. These are not aerofoils, so the geometry is not that critical, it's mostly balance and strength in response to the centrifugal forces and vibrations 28-Nov-20 03:50 PM 3D pantograph would be very neat though, what kind of reduction ratio are you looking to achieve? 28-Nov-20 03:51 PM the machine is capable of 10:1 28-Nov-20 03:51 PM I am likely a year away of getting access to it though (moving) 28-Nov-20 03:51 PM been paying storage fee on it, need to fly out just to move it elsewhere that is cheaper 28-Nov-20 03:53 PM So much of my stuff were damaged from my last move, never using a moving company again 28-Nov-20 03:53 PM yeah, the plan is to get a pickup and a trailer, and take as many trips as it takes 28-Nov-20 04:23 PM Wonder how @BestFleet is doing with his turbo. 29-Nov-20 12:38 AM Got my varian v80 controller, it's wayyy heavier than I expected... Seems bigger than it needs to be, assuming majority of that is all filtering 29-Nov-20 02:49 AM @nmz787 yep 30-Nov-20 06:07 AM So I'm confused about electrons and ions and conventional current 30-Nov-20 06:07 AM Like, my FIB has a Gallium ion source, they have a positive charge on the particles 30-Nov-20 06:07 AM So to accelerate them towards the specimen, what polarity power supply would be connected? 30-Nov-20 06:07 AM To the gallium? 30-Nov-20 06:07 AM 30kV + ??? 30-Nov-20 06:07 AM But if I'm buying say a glassman power supply, do they rate in conventional current power? Meaning + indicates an electron rich electrode? 30-Nov-20 06:07 AM So in conventional current, my FIB gun actually needs a 30kV - supply??? 30-Nov-20 06:07 AM So if in I want to add a SEM column to my FIB to make a dual beam, I need some kV + supply (again, in conventional current, the electron rich side of the circuit) for the e-beam gun? 30-Nov-20 03:25 PM It's usually specified as "electron current" or "ion current," and if not, if it's called "current" it's conventional current. 30-Nov-20 03:25 PM I have never seen a power supply where a "+" was labelled anything other than conventionally. 30-Nov-20 04:03 PM I am still confused... This page says it's for e beam, and says it's a negative supply https://www.spellmanhv.com/en/high-voltage-power-supplies/EVA 30-Nov-20 04:06 PM What's the problem? You bias the filament at a negative voltage with respect to ground, so the negatively charged electrons is accelerated away from the filament 30-Nov-20 04:06 PM So ion get power supply is positive wrtg 30-Nov-20 04:06 PM And electron gun is negative wrtg 30-Nov-20 04:06 PM I know people who turned ion gun power supplies into electron gun power supplies by reversing the polarity and vise versa 30-Nov-20 04:06 PM You still need a floating current transformer to heat the filament/tip 30-Nov-20 04:10 PM But like, I thought conventional current shows positive as the place where electrons are rich, thus eminating from there to the negative (where it's electron poor, or wanting to sink electrons) 30-Nov-20 04:10 PM Unless I'm totally forgetting my conventional current 30-Nov-20 04:10 PM In this case that's not what matters 30-Nov-20 04:10 PM We are creating electro static fields 30-Nov-20 04:11 PM The direction of flow of conventional current does not affect the voltage potential relation between the terminals of your power supply 30-Nov-20 04:11 PM In my head I thought conventional current was the opposite of physics 30-Nov-20 04:13 PM @AdamMcCombs Do you have any more info on this triode E-beam power supply? I'm looking for a replacement for my old oil-filled power supply, but the optical communication interface and the potted nature of this Spellman seems really difficult to RE https://www.ebay.com/itm/Spellman-EBM30N6-636-Triode-Supply-for-Electron-Beam-Columns/184306342302 30-Nov-20 04:17 PM That's off an fei feg column by the looks of it 30-Nov-20 04:17 PM So things in it are very strange 30-Nov-20 04:19 PM The non-OEM version of the Spellman EBM has analog voltage control, if the internals control electronics are the same and the HV section does take analog control, it may be possible to RE it 30-Nov-20 04:19 PM https://www.spellmanhv.com/en/high-voltage-power-supplies/EBM 30-Nov-20 04:19 PM The control requirements for that gun are pretty unique 30-Nov-20 04:19 PM Looks like @niklas has one of them 30-Nov-20 04:20 PM That's from a newer system that I don't have as much info on, but I do work with the gun it's for a lot, just with a different version of the power supply 30-Nov-20 04:21 PM Hmm, I can forget about trying to decode the serial interface (still can't really get through the one on the FLIR thermal camera), so my only solution is to look for that analog control I/O 30-Nov-20 04:22 PM Would you want a block diagram of everything that supply does? 30-Nov-20 04:23 PM Well the EBM manual is already pretty clear 30-Nov-20 04:23 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/EBM30NMAN_2-14C0F.pdf 30-Nov-20 04:23 PM How to talk to the power supply is the only problem 30-Nov-20 04:23 PM Spellman of course refuses to give me the manual for this OEM supply 30-Nov-20 04:24 PM Yeah that block diagram is completely wrong 30-Nov-20 04:24 PM As I said it's fei feg which makes it special ™ 30-Nov-20 04:25 PM Yeah sure, I wouldn't mind the block diagram for this the OEM power supply 30-Nov-20 04:25 PM I don't have the internal one, just the one for the gun itself 30-Nov-20 04:25 PM But basically the gun never run bellow 10kv 30-Nov-20 04:25 PM And you use the c0 lens for deceleration 30-Nov-20 04:26 PM “Conventional current” is with respect to positive charges 30-Nov-20 04:26 PM No electrons or positrons or ions or anything 30-Nov-20 04:26 PM Just “a coulomb” 30-Nov-20 04:27 PM And instead of traditional bias resistors or settings there's multiple hv supplies floating off of high voltage 30-Nov-20 04:27 PM These are to power the extractor and suppressor 30-Nov-20 04:27 PM So you might be able to use one of those for bias 30-Nov-20 04:28 PM That's really strange, I thought the aux HV would be for the suppressor, but never expected so much of other shenanigans in the gun 30-Nov-20 04:28 PM Fei feg is built like literally nothing else 30-Nov-20 04:28 PM The training I saw on it literally stated out with this is complicated and different than everything else so buckle up and pay attention 30-Nov-20 04:28 PM Like there's the generally accepted way you run feg guns 30-Nov-20 04:28 PM Which is what you see even in customer training on these scopes 30-Nov-20 04:28 PM And then there's how fei does it 30-Nov-20 04:30 PM https://www.ebay.com/itm/Spellman-DPL72I30-24-High-Voltage-Power-Supply/123774772314 30-Nov-20 04:30 PM There's this one too 30-Nov-20 04:30 PM *actually does it 30-Nov-20 04:30 PM If you find one with usb I might have that 30-Nov-20 04:30 PM But yeah the easiest ones are the ones with the analog interference 30-Nov-20 04:35 PM At some point the effort going into RE these OEM supplies would go beyond tearing down the oily mess that's my old power supply and troubleshooting that 30-Nov-20 04:37 PM Even the OEM service docs supposedly don't break down the can interface from what I have heard 30-Nov-20 04:37 PM At least the newer stuff 30-Nov-20 04:38 PM What oil do you use if you have to replace it in these old SEM power supplies? 30-Nov-20 04:39 PM I fix them or in many cases I have a spare 30-Nov-20 04:39 PM Oil does suck a lot but I just deal with it 30-Nov-20 04:40 PM Will any dielectric oil work? I don't think they require anything special, but just want to make sure I'm not going to break them again 30-Nov-20 04:41 PM I have heard of some additives causing problems with things like electrolytic caps 30-Nov-20 04:41 PM But just shell diala is what I normally use 30-Nov-20 04:41 PM What sem is this supply for again? 30-Nov-20 04:43 PM Hitachi S-450 30-Nov-20 04:43 PM Any idea what's wrong with it? 30-Nov-20 04:43 PM Or what the symptom is? 30-Nov-20 04:44 PM Just no HV output 30-Nov-20 04:44 PM I do have HV for the PMT 30-Nov-20 04:44 PM But no HV bias for the filament 30-Nov-20 04:44 PM Also it's empty of oil now since my last long distance move 30-Nov-20 05:19 PM First thing just look for a broken lead 30-Nov-20 05:19 PM More often than not that's the issue on these old oil tanks 30-Nov-20 05:27 PM Yeah this is a good opportunity to open it up while there's no oil inside. I'm just struggling to find transformer oil that's of a reasonable price and not in 50 gallon drums 30-Nov-20 05:55 PM Hmm, I was reading about some HV e beam/xray supply earlier today that specifically mentioned that it didn't need oil and how customers would appreciate that 30-Nov-20 05:56 PM Yeah none of the modern ones have any oil in them 30-Nov-20 05:56 PM All just potted but that makes the HV section completely inaccessible and impossible to repair if it fails 30-Nov-20 05:56 PM Unfortunately I didn't get a chance to do a more thorough diagnosis on my power supply, doing the turbopump conversion and building a new base just took too long 30-Nov-20 06:00 PM Ah 30-Nov-20 06:00 PM Potted or questionable oil , hrmm 30-Nov-20 06:01 PM As far as I can tell the oil containing vessel for the power supply is not sealed very well 30-Nov-20 06:01 PM When I took the SEM home I had to take the power supply out of the original extremely bulky base, and there were clearly quite a lot of oil residue around the supply 30-Nov-20 06:01 PM So it's very possible that a substantial amount of oil leaked out, the previous owner tried to apply HV and it arced inside 30-Nov-20 07:13 PM It's surprising how little oil it takes to make a massive mess 30-Nov-20 07:13 PM So long as nobody connects an oil pump in reverse and makes me clean it up, I’m good 30-Nov-20 07:15 PM <𝓕ermion#6024> we had a massive vacuum pump in the basement with some 6 inch diameter copper lines that snake around the building from the lab to the pump 30-Nov-20 07:15 PM <𝓕ermion#6024> and someone got oil into the lines :/ 30-Nov-20 07:15 PM <𝓕ermion#6024> too bad you can't call Big Tony's Vacuum Line Pipe Deoiling Service 30-Nov-20 07:15 PM <𝓕ermion#6024> just gotta throw them in the t r a s h 30-Nov-20 07:16 PM Saw that happen to a 12 inch waffer defect review sem 30-Nov-20 07:16 PM <𝓕ermion#6024> NOOO 30-Nov-20 07:16 PM Ran for 12 hours 30-Nov-20 07:16 PM <𝓕ermion#6024> N O O O 30-Nov-20 07:17 PM Pump was literally out of oil 30-Nov-20 10:37 PM The sem most certainly not 30-Nov-20 10:38 PM Lol you got that right 30-Nov-20 10:38 PM They took apart the stage on site and setup a cleaning line 30-Nov-20 10:38 PM I think it was after a 3rd party moved it 30-Nov-20 10:38 PM Because if it was oem service they would have just swapped 01-Dec-20 11:36 AM <𝓕ermion#6024> What's the appropriate replacement for a speedivalve if you can't tolerate leaks? It's a rare gas line 01-Dec-20 11:36 AM <𝓕ermion#6024> KF-25 size 01-Dec-20 11:36 AM <𝓕ermion#6024> maybe one of those bellow valves? 01-Dec-20 11:40 AM Do you actually need the conductance? The swagelok bellows-sealed valves are a good standard of "will not leak, unless you break it." 01-Dec-20 11:42 AM <𝓕ermion#6024> I suspect not. 01-Dec-20 11:42 AM <𝓕ermion#6024> swagelok is probably what I want 01-Dec-20 11:50 AM https://www.swagelok.com/en/catalog/Product/Detail?part=SS-4H-TW 01-Dec-20 11:50 AM These, are "perfect." If you overtighten them substantially, you can damage the bellows. So don't do that. 01-Dec-20 11:51 AM <𝓕ermion#6024> yeah my old PI always said use two fingers only 01-Dec-20 11:51 AM <𝓕ermion#6024> never palm it 01-Dec-20 11:52 AM The research associate in our lab tightens everything to the max 01-Dec-20 11:52 AM those included 01-Dec-20 11:52 AM <𝓕ermion#6024> awful 01-Dec-20 11:52 AM <𝓕ermion#6024> what's the best way to go from one of those to a KF flange? 01-Dec-20 11:54 AM TBH probably just getting an NPT valve and two NPT KF flanges. Maybe you should just get a bellows KF valve, since you don't need the high pressure capabilities... IDK 01-Dec-20 11:55 AM <𝓕ermion#6024> I'm not putting 3He through an NPT fitting lol 01-Dec-20 11:55 AM <𝓕ermion#6024> maybe it's ok actually? 01-Dec-20 11:55 AM <𝓕ermion#6024> I'm not sure... 01-Dec-20 11:55 AM <𝓕ermion#6024> I figured I should use VCR fittings or something 01-Dec-20 11:56 AM Oh 3He? just weld it 01-Dec-20 11:56 AM welded valve with welded KF fittings 01-Dec-20 11:57 AM <𝓕ermion#6024> might as well get a KF valve at that point hehe 01-Dec-20 11:58 AM they're chunkier for conductance purposes 01-Dec-20 11:59 AM <𝓕ermion#6024> yeah I'm not super size constrained or anything 01-Dec-20 11:59 AM but NPT Is what's on your bottle regulator, isn't it? 01-Dec-20 11:59 AM it's a pretty solid connection. 01-Dec-20 11:59 AM VCR is more about being nice to connect/disconnect 01-Dec-20 12:01 PM <𝓕ermion#6024> naw everything is welded/soldered or KF 01-Dec-20 12:01 PM <𝓕ermion#6024> we don't have a bottle so much as a keg which is kept below 1 atm 01-Dec-20 12:01 PM <𝓕ermion#6024> so it gets contaminated instead of leaking prescious coldmaking juice 01-Dec-20 12:07 PM I feel like I wouldn't really want to be using KF haha 01-Dec-20 12:07 PM I'd be welding and CF everything if it was an ongoing risk 01-Dec-20 12:07 PM suboptimal 01-Dec-20 12:25 PM <𝓕ermion#6024> why do most KF hoses top out around 40 in? 01-Dec-20 12:25 PM <𝓕ermion#6024> do most people just chain multiple together over a long distance? 01-Dec-20 12:27 PM hoses as in metal bellows? 01-Dec-20 12:27 PM we use KF with the spring-reinforced pvc lines 01-Dec-20 12:27 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/8902-Spring-Wire-Suction-Hose-32BF3.png 01-Dec-20 12:27 PM I believe it came in a 100' spool on a pallet. 01-Dec-20 12:35 PM I believe that is just because those are made by hydroforming and to make longer one, you would need bigger machine/mold... 01-Dec-20 12:36 PM <𝓕ermion#6024> ahhh ok! 01-Dec-20 12:38 PM They'd also get unmanageably heavy? 01-Dec-20 12:38 PM much better / lighter to alternate between them and straight tubes in between 01-Dec-20 02:19 PM I’ve always thought Swagelok VCR looks really hard to use compared to normal Swagelok - so, you can’t just install a ferrule on the end of a 1/4” line, you need to buy the VCR stub part and weld it on? Or am I misunderstanding how they work? 01-Dec-20 02:21 PM They're much easier to do up and undo repeatedly 01-Dec-20 02:21 PM and I think they do better vacuum 01-Dec-20 02:25 PM They have ~ 4-5 orders better leakrate, better temperature resitance (mainly against leak in extreme temperatures) and better reliability... 01-Dec-20 02:27 PM they have near perfect reliability 01-Dec-20 02:27 PM like as good as CF 01-Dec-20 02:29 PM yeah, everyone says "near perfect" or "excelent", but unfortunately it is impossible to get some real reliability numbers... 01-Dec-20 02:29 PM at work, we want to use ~hundered of those in nearly inaccesible place and now we are bit lost, because we don't really know the reliability to get some failure estimate... 01-Dec-20 02:49 PM the reliability I'm referring to is more like "repeatability" 01-Dec-20 02:49 PM you can redo a VCR fitting thousands of times, nbd 01-Dec-20 02:49 PM swagelok compression fittings only get iffier and iffier 01-Dec-20 03:55 PM <𝓕ermion#6024> ok I think I've asked this before but if you had a dry roughing pump that was pumping down a large volume of helium, but you wanted to recover to a system that had a small volume and couldn't be pressurized, how could you design the manifold? 01-Dec-20 03:55 PM <𝓕ermion#6024> I wanna say I want a overpressure valve and maybe a speedivalve 01-Dec-20 03:55 PM <𝓕ermion#6024> that way it blows off through the overpressure valve for a while and then you can connect to the system. 01-Dec-20 03:55 PM <𝓕ermion#6024> the system that's being pumped on is a 1k pot so it's constantly sipping in new lhe. there's more coming after the initial volume of helium and who knows what 01-Dec-20 03:55 PM <𝓕ermion#6024> I'm cool with blowing off the initial large volume 01-Dec-20 04:04 PM <𝓕ermion#6024> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-C2C47.png 01-Dec-20 05:15 PM Way beyond my experience but my approach would be to start off from: 1) Do enough math to see what sort of volume of gas you need to be planning for. 2) What pressure is ideal for the intake of the He recovery system? 3) How can those two best be achieved with the fewest parts while respecting the 0.2bar max outlet pressure? 01-Dec-20 05:15 PM You might need some creative pressure sensing and venting control if you cannot design the system to run most of the time with your expected gas loads 01-Dec-20 05:15 PM That seems like it would not be fun to design in a way that also is fail safe 01-Dec-20 05:17 PM <𝓕ermion#6024> will likely yeet it and use two hand operated speedivalves 01-Dec-20 05:19 PM Can you stash a buffer tank/pumping system to feed the He recovery system? 01-Dec-20 05:19 PM Or is that what the He recovery system is 01-Dec-20 05:19 PM <𝓕ermion#6024> recovery system is just a stainless keg with a pulse tube dropped in it 01-Dec-20 05:19 PM <𝓕ermion#6024> and a spout 01-Dec-20 06:30 PM Ok everyone. Berilium has been a topic that has come up a few times, and every time @funranium is sure to point out the hazardous associated with it. Allow me to demonstrate what he is talking about: 01-Dec-20 06:30 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/PXL_20201202_013219008-6F6E9.jpg 01-Dec-20 06:30 PM This is what happens when a berilium window is exposed to moisture, that's all berilium oxide covering it, and is ready to flake off and become a respiratory hazard. 01-Dec-20 06:30 PM This is from a x-ray tube I pulled tonight for what was supposed to be a routine swap on the high voltage insulating grease. Turned out there was a water leak on the target assembly and now we have a hazardous was situation. 01-Dec-20 06:30 PM This was not even a big leak, just enough to raise the humidity. Seriously if you can avoid this stuff do so. 01-Dec-20 07:42 PM That is a friable BeO nightmare waiting to happen, kinda like kicking a puffball mushroom. There is so much NOPE and sphincter clench right there. If it doesn't give you that reaction, work on it. You need to improve your sense of self-preservation and care for your work area. 01-Dec-20 08:58 PM what's the polarizability tensor and rotational constant of BeO 01-Dec-20 08:58 PM I wonder if we could spin it 01-Dec-20 08:58 PM (joking) 01-Dec-20 08:58 PM HF is an interesting one, and CL2 has been done >.< 01-Dec-20 09:54 PM Yeah this was an interesting experience for me. It's not often I have surprise hazard show up right in front of me like that. I normally feel like I'm in control of the risks I am facing and can always mitigate it before hand, but when I realized just what I had pulled out in front of me, it wasn't a hazard I was prepared for in that instant. It took taking a step back, making a call to our resident server EHS, and to start taking proper decon steps to feel ok again. 01-Dec-20 10:20 PM [salutes] Just doin' my part, chief. 02-Dec-20 12:41 AM looks like something you can toss a piece of nice tape over and seal up 02-Dec-20 12:41 AM you can buy whole bicycles made from Be! 02-Dec-20 12:41 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/44020814551_1052c596b6_b-E3516.png 02-Dec-20 07:03 AM Yes. You can, at exorbitant prices, and then you get to dispose of it a hazardous waste at the end of life. Also, the first scratch you put on it puts you on the path to shedding oxide. They’re a toxic novelty. 02-Dec-20 07:20 AM <𝓕ermion#6024> Also it’s pretty common practice in microwave labs to file pins to the proper length to get the right coupling to a cavity 02-Dec-20 07:20 AM <𝓕ermion#6024> And those pins are usually beryllium copper. 02-Dec-20 07:20 AM <𝓕ermion#6024> Not sure how awful that is. 02-Dec-20 07:23 AM Is beryllium bronze still common in that use? 02-Dec-20 07:23 AM Damn now I have to be increasingly suspicious of all old microwave gear in my hoard 02-Dec-20 07:27 AM Beryllium bronze is not easilly replaceable in some applications, for example vacuum screw clamp contact for thick gauge wires are still made from beryllium bronze... (http://www.vacom-shop.de/epages/VacomShop.sf/en_GB/?ObjectPath=/Shops/Store.VacomShop/Categories/0000000625/0000000746/0000001185/0000001188) 02-Dec-20 07:33 AM Yeah 02-Dec-20 07:33 AM In hindsight it was REALLY good I did not pursue that project about those laser cut beryllium bronze springs for one application in vacuum + cryo 02-Dec-20 07:33 AM Especially when it later turned out the company I found to do it was of the "one man and a shed"-type. 02-Dec-20 07:45 AM <𝓕ermion#6024> how do I become one of those? 02-Dec-20 07:45 AM <𝓕ermion#6024> haven't found my niche yet 02-Dec-20 07:45 AM <𝓕ermion#6024> trying to tread the line between "is this guy a free energy weirdo" and "I guess this guy is the only game in town for this part we need :/" 02-Dec-20 07:47 AM Well in this case it was a friend of a friend to a small machine shop operator I knew from IRC 02-Dec-20 07:47 AM And apparently had gotten a laser cutter cheaply 02-Dec-20 07:47 AM And was greedy and mad enough to agree to laser us some beryllium bronze parts 02-Dec-20 07:47 AM Likely because they did not know what it was 02-Dec-20 07:47 AM And back then I was not properly aware of the risks 02-Dec-20 07:48 AM <𝓕ermion#6024> hmm what does ablated beryllium turn into? 02-Dec-20 07:48 AM Only having dealt with BeO in semiconductors, where it is quite safe if not disturbed 02-Dec-20 07:48 AM <𝓕ermion#6024> ah yes. Much like alligators 02-Dec-20 07:50 AM Yes, much like alligators compress them into nice non-friable ceramics and then don't smash them for funzies. 02-Dec-20 07:53 AM Speaking of "one man and a shed" The operators of that style of companies sure do have their own niche. I know one that makes Porsche spare parts and does so to a handful of clients, email and phone only, no web site or web presence at all. One recently hired another engineer to his company, he does embedded design, both software and hardware. Including weird stuff like spectrometers, lasers, optics and so on. 02-Dec-20 07:53 AM Honestly the niche seems to be being competent and reasonably networked so that work flows your way. 02-Dec-20 07:58 AM BeCu alloy was the traditional "safe" form of beryllium, other than ceramic and emeralds. Unfortunately, we learned pretty quickly through testing non-sparking tools that the alloy decomposes, especially if it's gotten a bit beat up with use, with the Be starting to oxidize out of it and shedding BeO wherever the item was stored. Don't see a lot of it around in consumer items anymore. Brush-Wellman got burnt in a lot of lawsuits. 02-Dec-20 08:39 AM <𝓕ermion#6024> I guess there's not a ton of Be in BeCu 02-Dec-20 09:15 AM Enough to be a problem if not handled carefully. 02-Dec-20 09:23 AM It makes verrry nice tools though that dont mar up steel parts. My BeCu pliers are by far my favorite pliers. 02-Dec-20 09:41 AM I'm glad you like them. 02-Dec-20 10:21 AM For anyone who has to use their respirator in situations where perfect fit is critical, these are great to have: https://www.amazon.com/Allegro-Industries-Respirator-Fit-Check-Ampoules/dp/B08GQD7YST 02-Dec-20 10:21 AM They are small and easy to use, and can help ensure that you are actually being fully protected by your respirator when you use it. A p100 is not a p100 if it's leaking around the sides. I was very happy to have them yesterday before having to deal with BeO. 02-Dec-20 10:42 AM no facial hair allowed! 02-Dec-20 10:42 AM little part of me dies inside when i see someone wearing a respirator and a full beard 02-Dec-20 10:44 AM they just have a strong smell that's filtered by the mask? 02-Dec-20 10:44 AM Would that work for P100 though? Unless combined with an organic vapor filter? 02-Dec-20 10:46 AM beard filter 02-Dec-20 10:46 AM /s 02-Dec-20 10:48 AM some of the other qualitative ones (smoke and saccharin varieties) work with just particulate filters. Dunno about the banana one though, no experience myself with that 02-Dec-20 10:48 AM https://i.redd.it/fjf612pvw7q01.jpg 02-Dec-20 10:48 AM I will tell you that amyl acetate does smell to high heaven 02-Dec-20 10:48 AM Made some last year 02-Dec-20 10:49 AM my eyes itch seeing that 02-Dec-20 10:50 AM haha 02-Dec-20 10:51 AM I just go full cousin itt when I need extra dust protection, just drop all my hair in front of my face 02-Dec-20 10:54 AM Yes, that's correct 02-Dec-20 10:54 AM There's a Stannic Chloride snake based version you can also use 02-Dec-20 11:21 AM I recall reading that the medical side N95 mask test is to use powdered sweeteners of some sort 02-Dec-20 11:21 AM "if you taste sweet it's not on properly" 02-Dec-20 11:37 AM yep, they basically spray your face with sweet'n'low mist (saccharine). source; wife is medical provider 02-Dec-20 11:37 AM bitterants are common too, although folks like them less for obvious reasons 02-Dec-20 11:39 AM *smoke based 02-Dec-20 12:16 PM i prefer to continue reading that as snake based testing. if a snake can get into your respirator, the fit is no good! 02-Dec-20 01:09 PM I prefer the quick and easy (but not at all "approved") test of covering the filter bayonet attachments with your palms and inhaling gently 02-Dec-20 01:09 PM The mask should pull tightly to your face and you definitely feel even tiny leaks 02-Dec-20 02:44 PM funny enough this is the same chemical in "juicy fruit" chewing gum 02-Dec-20 02:44 PM Isoamyl acetate 02-Dec-20 04:45 PM instructions unclear, chewing gum is stuck in my respirator filter cartridge 03-Dec-20 10:06 AM Joined the server. 04-Dec-20 03:58 PM Welcome! 06-Dec-20 09:23 AM <𝓕ermion#6024> Hey does anyone have a read on general fusion? 06-Dec-20 09:23 AM <𝓕ermion#6024> Are they legit or like the d-wave of fusion? 06-Dec-20 09:23 AM <𝓕ermion#6024> Their leadership seems kinda ??? 06-Dec-20 09:24 AM aren't they the steam hammer fusion guys? 06-Dec-20 09:24 AM their whole concept seems a bit iffy to me tbh 06-Dec-20 09:25 AM <𝓕ermion#6024> Yeah. 06-Dec-20 09:26 AM I guess there's a reason why there are multiple companies and organisations doing research on tokamaks, stelarators and the likes, but only one that wants to do pneumatic fusion 06-Dec-20 09:27 AM <𝓕ermion#6024> I think this community is quite conservative and it’s likely fairly hard to get funding for out-there ideas. 06-Dec-20 09:27 AM <𝓕ermion#6024> But you could say that about free energy too lolol 06-Dec-20 09:28 AM https://en.wikipedia.org/wiki/Bubble_fusion 06-Dec-20 09:28 AM lots of controversy and no definite proof that anything works 06-Dec-20 09:28 AM wiki articles about science topics without any maths in them are... problematic imo 06-Dec-20 09:35 AM <𝓕ermion#6024> Is bubble fusion what they’re trying to do? 06-Dec-20 09:35 AM <𝓕ermion#6024> https://en.m.wikipedia.org/wiki/Magnetized_target_fusion 06-Dec-20 09:35 AM <𝓕ermion#6024> I think they wanna do this 06-Dec-20 09:35 AM <𝓕ermion#6024> The hammer hits an anvil and makes acoustic waves 06-Dec-20 09:50 AM hmm then I must have misunderstood their concept 06-Dec-20 09:50 AM hm. 06-Dec-20 10:39 AM There is an LENR company in berkeley 06-Dec-20 10:39 AM Supposedly SRI thinks highly of them 06-Dec-20 10:39 AM https://brillouinenergy.com/test-results 06-Dec-20 10:39 AM I cant understand their papers tbh 06-Dec-20 10:40 AM http://techfinder.stanford.edu/technologies/S15-304_low-cost-atmospheric-electron 06-Dec-20 10:44 AM @𝓕ermion the general fusion CEO did his PhD in my lab. not with my PI, but in the physical lab itself! 06-Dec-20 10:44 AM we have screwdrivers with his supervisor's name engraved on them 06-Dec-20 10:44 AM and HV PSUs from those experiments 06-Dec-20 10:44 AM and I through out a giant box of dot-matrix plots of spectra they recorded 06-Dec-20 10:45 AM <𝓕ermion#6024> oh wild! 06-Dec-20 10:48 AM they were doing laser fusion experiments long ago 06-Dec-20 10:48 AM https://open.library.ubc.ca/collections/arphotos/items/1.0147623 06-Dec-20 10:48 AM sorry, "Founder and Chief Scientist" 06-Dec-20 10:48 AM not CEO 06-Dec-20 12:42 PM <𝓕ermion#6024> any idea why a helium recovery system would want large diameter pipe? 06-Dec-20 12:42 PM <𝓕ermion#6024> like NW40 or something 06-Dec-20 12:42 PM <𝓕ermion#6024> even at 1 bar-ish? 06-Dec-20 12:44 PM maybe as a buffer volume in case some lhe gets in there and flash-evaporates 06-Dec-20 12:45 PM <𝓕ermion#6024> hmm 06-Dec-20 01:15 PM <𝓕ermion#6024> anyone have a suggestion for a valve to put on the backing side of a pump to prevent backstreaming? 06-Dec-20 01:15 PM <𝓕ermion#6024> like a flap valve or something 06-Dec-20 01:15 PM <𝓕ermion#6024> just not sure what's appropriate 06-Dec-20 05:47 PM like a suckback valve? 06-Dec-20 05:47 PM i've heard of NC electric solenoid valves being wired into the roughing pump's power circuit for something like that 06-Dec-20 05:55 PM That’s how ours are. 06-Dec-20 05:55 PM <𝓕ermion#6024> What about a valve on the outlet? 06-Dec-20 05:56 PM To make a bomb? 06-Dec-20 05:56 PM <𝓕ermion#6024> What do you mean? 06-Dec-20 05:56 PM My pump specs a max outlet pressure of 7 bar 06-Dec-20 05:56 PM <𝓕ermion#6024> Mine is a fraction of a bar but 06-Dec-20 05:56 PM <𝓕ermion#6024> If you stick a nonreturn valve there 06-Dec-20 05:57 PM Measured or specced max? 06-Dec-20 05:57 PM <𝓕ermion#6024> Specced max. 06-Dec-20 05:58 PM Nice 06-Dec-20 05:58 PM <𝓕ermion#6024> I just don’t wanna suck helium from the recovery system back into the 1 K pot. 06-Dec-20 05:58 PM Considering the cost of all this 06-Dec-20 05:58 PM Why... why not hire a cryogenics company to design it? 06-Dec-20 06:00 PM <𝓕ermion#6024> I mean... I don’t really think that’s necessary. 06-Dec-20 06:01 PM Of course not 06-Dec-20 06:01 PM But it probably wouldn’t be too bad 06-Dec-20 06:01 PM <𝓕ermion#6024> Someone from Oxford was helping me but they’re super busy. 06-Dec-20 06:01 PM <𝓕ermion#6024> And I think mostly doing it out of goodwill. 06-Dec-20 06:01 PM <𝓕ermion#6024> But I mean, why not put a nonreturn valve on the output of most pumps? 06-Dec-20 06:01 PM <𝓕ermion#6024> Your pump has a 7 bar max output pressure, you can get one that pops at much less. 06-Dec-20 06:01 PM <𝓕ermion#6024> There’s one I saw that’ll pop at half a PSI 06-Dec-20 06:15 PM I hate gauge pressure 06-Dec-20 06:15 PM So weird 06-Dec-20 06:16 PM <𝓕ermion#6024> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image-D9DD3.png 06-Dec-20 06:16 PM <𝓕ermion#6024> I guess some people do run a check valve? 06-Dec-20 06:40 PM They come with some pumps 07-Dec-20 01:59 AM https://onlinelibrary.wiley.com/doi/pdf/10.1002/sca.4950130604 07-Dec-20 01:59 AM Cryopump Vibration Isolation System for an SEM 07-Dec-20 01:59 AM "The pump is then connected to the chamber by a series of standard isolation bellows and right angle pieces (Fig. 2). The soft copper bellows are used for the pump vibration isolation and dampening. Similar bellows have been successfully used to isolate turbomolecular pumps on several models of AMRAY SEMs for many years." 07-Dec-20 01:59 AM I can't tell if they're talking simply about metal bellows, or the ones with rubber surrounding the bellow 07-Dec-20 01:59 AM and, can a normal metal bellow just be wrapped in some slab of rubber and then secured with a hose clamp (or two or three)? 07-Dec-20 08:14 AM Doesn't look like the rubber is around the bellows? 07-Dec-20 08:14 AM sounds like bellows = copper vacuum bellows, only 07-Dec-20 08:14 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/IMG_9512_beryllium-425CE.png 07-Dec-20 12:29 PM huh, interesting... wouldn't copper bellows slowly work-harden from the vibration over time? 07-Dec-20 02:42 PM This residual gas analyser is neat. There is a discernible shift between 4He and D2, which have a tiny, tiny mass defect, so the quadrupole resolution is pretty good for something built from scratch. https://www.rapp-instruments.de/Radioaktivitaet/div/quadropol/quadro.htm 07-Dec-20 02:42 PM I’ve never seen a copper bellows before. I think work hardening would be an issue. Would be much easier to join with solder though. 07-Dec-20 02:44 PM we have several 07-Dec-20 02:44 PM older than me 07-Dec-20 02:44 PM they're stiff but still vibration-damp 07-Dec-20 02:44 PM and allow for port misalignment, that's a common application 07-Dec-20 05:36 PM <𝓕ermion#6024> what's a good tube for transporting helium around the lab? 07-Dec-20 05:36 PM <𝓕ermion#6024> there's a bunch of old tygon and it's like eh. 07-Dec-20 05:36 PM <𝓕ermion#6024> maybe I should just replace the tygon with new tygon? 07-Dec-20 05:36 PM <𝓕ermion#6024> it seems like there has to be a better choice... 07-Dec-20 05:41 PM I assume you mean when it's cold?... 07-Dec-20 05:41 PM <𝓕ermion#6024> no no, when warm 07-Dec-20 05:41 PM Why would you not just use stainless? 07-Dec-20 05:41 PM <𝓕ermion#6024> this is just for a 15 psi helium line 07-Dec-20 05:41 PM are you using regular swagelok connections? 07-Dec-20 05:42 PM <𝓕ermion#6024> someone seems to have used regular swagelok but I think there's special ones for plastic hoses 07-Dec-20 05:42 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/industrial-hose-maintenance_640x320-A4F87.png 07-Dec-20 05:42 PM I like the two types of stainless flexible hose 07-Dec-20 05:42 PM middle can do like 2 bar, right can do like 100. 07-Dec-20 05:42 PM FJ series or something from swagelok? 07-Dec-20 05:42 PM and then just use rigid 1/4" between those. 07-Dec-20 05:42 PM I hate the black polyethylene tubing, even though we use it. It eventually hardens and cracks easily 07-Dec-20 05:44 PM <𝓕ermion#6024> what about FEP? 07-Dec-20 05:48 PM that's the stuff that feels weird right 07-Dec-20 05:48 PM tygon is nicer but just ages weird right? 07-Dec-20 05:48 PM and like disintegrates with age or something, instead of hardening? 07-Dec-20 05:57 PM <𝓕ermion#6024> ugh I'm not sure. I think FEP is stiffer and milky white 07-Dec-20 06:43 PM Yeah specific plastic swagelok is a thing 07-Dec-20 06:43 PM How much does purity matter? 08-Dec-20 08:06 AM <𝓕ermion#6024> @AdamMcCombs Matters quite a lot. 08-Dec-20 08:06 AM <𝓕ermion#6024> This is helium that feeds into a liquifier 08-Dec-20 09:27 AM Oh He-3 for a liquefier? 08-Dec-20 09:27 AM Sounds like a lot of money 08-Dec-20 09:27 AM Are you liquefying the He-3, or using the He-3 as the working fluid in a liquefier? 08-Dec-20 09:30 AM <𝓕ermion#6024> nooooo no the 3he stays inside the fridge or inside a gas handling system, cryopump, or keg. 08-Dec-20 09:30 AM <𝓕ermion#6024> this is for 4he 08-Dec-20 09:30 AM <𝓕ermion#6024> nothing special. I just don't want it to get wet or get nitrogen in it. 08-Dec-20 09:30 AM <𝓕ermion#6024> and I just kinda hate tygon tube. 08-Dec-20 09:30 AM <𝓕ermion#6024> and PVC 08-Dec-20 09:34 AM Ah, then regular braided stainless hoses for helium compressors would work well, sounds like you've got the budget for it 08-Dec-20 09:34 AM <𝓕ermion#6024> it's low pressure. 08-Dec-20 09:34 AM <𝓕ermion#6024> braided stainless just seems like. a bit much. 08-Dec-20 09:34 AM They've got Eaton connectors at the ends, and is good for maintaining high purity 08-Dec-20 09:34 AM The braided stainless is not the important part, but you won't be able to completely avoid air inclusion with regular swagelok or VCR fittings 08-Dec-20 09:34 AM Unless you are willing to do a lot of purging 08-Dec-20 09:37 AM <𝓕ermion#6024> I might just use rapidair hose 08-Dec-20 09:37 AM <𝓕ermion#6024> and then stick SS-QC4s on them 08-Dec-20 09:40 AM Also you presumably have filters? 08-Dec-20 09:40 AM Not that they’re perfect 08-Dec-20 09:41 AM <𝓕ermion#6024> oh no -- what are the filters for? 08-Dec-20 09:41 AM But the 0.5um filters are supposedly helpful for keeping it clean from macroscopic debris that can’t be pumped away 08-Dec-20 09:42 AM <𝓕ermion#6024> the thing is that contaminants will plate out inside the liquifier, which is occasionally warmed up and cleaned, so it's not SUPER sensitive 08-Dec-20 09:42 AM <𝓕ermion#6024> I'm not shooting the helium through a tiny nozzle like you are 08-Dec-20 09:46 AM Then it doesn’t does it? Is this 6.0, 5.0, or 4.5? 08-Dec-20 09:53 AM <𝓕ermion#6024> haha I guess it's all relative. 08-Dec-20 09:53 AM <𝓕ermion#6024> https://www.airgas.com/p/HE%20HP300 08-Dec-20 09:53 AM <𝓕ermion#6024> it's just this stuff 08-Dec-20 09:56 AM 4.8, ah 08-Dec-20 03:30 PM Even 4.5 He is expensive enough, let alone 6.0 or 3He 08-Dec-20 03:42 PM depends how much you use/leak ¯\_(ツ)_/¯ 08-Dec-20 03:42 PM it'd have to be a pretty huge leak to be a meaningful cost at 15psi? 08-Dec-20 04:08 PM <𝓕ermion#6024> I guess as long as it's at positive pressure, not much can happen. 08-Dec-20 04:24 PM turn that 4.5 He into 1.0 He 08-Dec-20 05:53 PM I think if you want really oxygen-free nitrogen you can’t use plastic lines as oxygen diffuses through it, you need all-metal lines. I would expect He is the same. 09-Dec-20 11:32 AM My recollection is that the one one in the middle and on the right are VCR connections. Middle looks like half inch and the one on the right is 3/8 or 1/4. I've had to build a dinky little vacuum system with them before, so I'm used to scraping ebay for that kind of stuff. Crush gasket type connections. I don't know if that was in question or not, now, but I'll just put it out there. 09-Dec-20 11:35 AM The hoses are available with a multitude of connectors 09-Dec-20 11:35 AM https://www.swagelok.com/downloads/webcatalogs/EN/MS-01-180.PDF 09-Dec-20 11:35 AM We have a valve panel which runs stainless lines from our tank room to our lab 09-Dec-20 11:35 AM and then use either FJ or FM series to connect to the tank regulators, or cheaper stuff like polyethylene depending on what we're doing. (50bar He 6.0 is in FJ series. 5bar N2 is in polyethylene, for example.) 09-Dec-20 11:35 AM This is the FJ series, ours are swagelok tube fittings on the end. 09-Dec-20 11:35 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-2E35B.png 09-Dec-20 11:41 AM It's in the same room for us, but we have the same set up 09-Dec-20 11:41 AM Tank-regulator-FJ4 connector-Stainless lines to the instrument 09-Dec-20 11:41 AM And use some kind of plastic for our nitrogen lines because purity isn't a big deal 09-Dec-20 12:01 PM I’m pretty sure my N2 line dates back to jochen meyer 09-Dec-20 07:28 PM <𝓕ermion#6024> Anyone know what my RGA is picking up around 16-19? I wanna say water 09-Dec-20 07:28 PM <𝓕ermion#6024> Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/image0-78E88.jpg 09-Dec-20 07:28 PM <𝓕ermion#6024> Just surprised there’s so much. 09-Dec-20 07:28 PM <𝓕ermion#6024> Also weirded out by the peak at 1 amu. 09-Dec-20 07:28 PM <𝓕ermion#6024> Not sure what that could be 09-Dec-20 07:31 PM uh, what's new from last time? 09-Dec-20 07:31 PM RGA sitting on a shelf and filthy filament? new vacuum system with leaky water-cooling? 09-Dec-20 07:31 PM <𝓕ermion#6024> Oh this is my first time using it. 09-Dec-20 07:32 PM I think it has a degas mode somewhere 09-Dec-20 07:32 PM <𝓕ermion#6024> And it’s been sitting literally on the floor lol. 09-Dec-20 07:32 PM <𝓕ermion#6024> In a storage room. 09-Dec-20 07:32 PM go to p vs t mode 09-Dec-20 07:32 PM and set it to 17 and 18 09-Dec-20 07:32 PM and just watch it, I guess ? 09-Dec-20 07:32 PM <𝓕ermion#6024> Hmmmm ok. 09-Dec-20 07:32 PM <𝓕ermion#6024> Well I’m home now. Maybe I should have just left the filament on and left it pumping overnight or something. 09-Dec-20 07:34 PM oh definitely lol 09-Dec-20 07:34 PM remote access? 09-Dec-20 07:34 PM <𝓕ermion#6024> Noo no lol. 09-Dec-20 07:34 PM <𝓕ermion#6024> I’ll do it tomorrow or something. 09-Dec-20 07:34 PM <𝓕ermion#6024> The manual had a section about sampling high and medium pressure gasses — have you ever done this kind of thing with an orifice or capillary or whatever? 09-Dec-20 07:37 PM nah we basically just use it to look for helium oligomers 09-Dec-20 07:37 PM but water is never that high with a turbo for us 09-Dec-20 07:39 PM <𝓕ermion#6024> This whole lab is one huge wet basement basically lol 09-Dec-20 07:41 PM our ceiling leaks. 09-Dec-20 07:56 PM Yeah, our water is never that high either and we don't exactly have a good environment for not having water contamination 09-Dec-20 08:07 PM Surely you have another pressure gauge? 09-Dec-20 08:07 PM That’s how you check where the issue is 12-Dec-20 01:59 AM what is the best way to extend short stubby feed throughs? 12-Dec-20 01:59 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/unknown-D6421.png 12-Dec-20 01:59 AM etc 12-Dec-20 02:02 AM I've always just screwed something onto there 12-Dec-20 02:02 AM easiest case is a big screw terminal 12-Dec-20 02:03 AM i've got to extend it a good 150mm or so through this tee 12-Dec-20 02:03 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/st0036808-mdc-stainless-uhv-high-vacuum-te-BF41A.png 12-Dec-20 02:03 AM side port is used for a vac guage 12-Dec-20 02:04 AM cut a thread in the end and screw a longer rod on 12-Dec-20 02:04 AM hm 12-Dec-20 02:04 AM https://www.idealvac.com/Electrical-Power-In-Line-Connector-for-0260-in-dia-wire/pp/P108159 these are apparently a thing but I only need 2, not 10 lol 12-Dec-20 02:04 AM until I find a magnetron I figure I can try out some evaporation 12-Dec-20 02:05 AM screw terminal 12-Dec-20 02:05 AM no idea how they're called in englisch 12-Dec-20 02:05 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/2Q-E9DD5.png 12-Dec-20 02:05 AM take off the plastic and boom 12-Dec-20 02:06 AM oh hm, not a bad idea 12-Dec-20 02:06 AM I may even have one the right size somewhere in my hundreds thousands of kilograms of crap 12-Dec-20 02:06 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20201212_021119-B5B10.jpg 12-Dec-20 02:06 AM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/20201212_021223-8C471.jpg 12-Dec-20 02:06 AM Excellent 12-Dec-20 02:14 AM isn't that the wrong side? 12-Dec-20 02:15 AM These ones are funny, knife edge is on this side 12-Dec-20 02:15 AM wth 12-Dec-20 02:16 AM Idk, it's a varian part too 12-Dec-20 08:19 AM ummm 12-Dec-20 08:19 AM huh. 12-Dec-20 09:27 AM I always wondered why those are this way around, i also have a few of them 12-Dec-20 12:13 PM Actually like it this way because it makes more sense for low pressure gas 12-Dec-20 12:13 PM In fact I'm confused why insulators in the vacuum tend to be shorter, as the atmosphere is pretty good at holding back electricity at high pressure 12-Dec-20 12:16 PM nothing in a vacuum to ionize to help form an arc I'd imagine 12-Dec-20 12:17 PM But before you get to that point there's a valley where Ionizing the environment is really easy 12-Dec-20 12:17 PM And then after that point you end up with field emission when you have large voltage gradients 12-Dec-20 12:18 PM fair 12-Dec-20 12:29 PM Uh, take another look at the breakdown voltage of vacuum 12-Dec-20 12:29 PM Most feedthroughs specify the vacuum range they’re meant for 12-Dec-20 12:29 PM My shv-20 ones are all for 1E-4 torr or lower, only. 12-Dec-20 12:36 PM It is about paschen law. If you are in UHV levels, breakdowns almost don't exist. If you are around RVP vacuum levels, even 20 cm long insulator will not help you... 12-Dec-20 12:38 PM No suitable HV emotes 12-Dec-20 12:43 PM We are currently solving issue this kind for our new tokamak at work - all the coils (max voltage +- 1 kV) will be situated in pumped cryostat with pressure around 10^-4 Pa. At this pressure level everything is fine, however when something breaks and atmosphere is introduced during the discharge, we will probably have big issue because arc can be created easilly (and energy stored inductively in coils is huge) and it is very hard to insulate everything... 12-Dec-20 02:26 PM <𝓕ermion#6024> has anyone ever set up something to circulate rare gas through a cold trap? 12-Dec-20 02:26 PM <𝓕ermion#6024> I have a sealed multistage roots I could use 12-Dec-20 02:26 PM <𝓕ermion#6024> I'm just not sure if I should use an impedance somewhere so the roots sees a low input pressure 12-Dec-20 02:26 PM <𝓕ermion#6024> like before the cold trap 12-Dec-20 02:26 PM <𝓕ermion#6024> so it goes gas volume -> impedance -> trap -> roots -> gas volume 12-Dec-20 02:26 PM <𝓕ermion#6024> or something. 13-Dec-20 08:01 PM hey, someone I know wants to identify this leitz thing... any ideas? 13-Dec-20 08:01 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Leitz_Device-99020.png 13-Dec-20 08:01 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Leitz_Device_back-D1137.png 13-Dec-20 08:01 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Leitz_Device_bottom-76DED.png 13-Dec-20 08:01 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Leitz_Device_labels-FFA13.png 13-Dec-20 08:01 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/Leotz_Device_side-441CD.png 13-Dec-20 08:01 PM It looks similar in design to their microscope power supplies 13-Dec-20 08:01 PM but obviously has the 2D CRT 14-Dec-20 03:48 AM I had a hunt and found nothing, but I did enjoy learning about the history of leitz wetzlar and going through random historical archives 14-Dec-20 12:46 PM Best guess is a stage position indicator 14-Dec-20 12:46 PM I have seen the jeol and (I think) Zeiss version before. 15-Dec-20 12:26 AM are there any materials that can be used as reuseable cryogenic gas seals sort of like o-rings? 15-Dec-20 12:26 AM having to redo the seal with indium everytime is a bit annoying 15-Dec-20 06:01 PM <𝓕ermion#6024> You have to use indium. 15-Dec-20 06:01 PM <𝓕ermion#6024> Oh you might try a conical seal 15-Dec-20 06:01 PM <𝓕ermion#6024> Keeping it gas tight requires pristine surfaces so it won’t survive anything less than the most delicate handling. 15-Dec-20 06:04 PM I think gold works too 15-Dec-20 06:04 PM some helium droplet nozzles use it instead of indium because it's easier to shape (and keep the shape) 15-Dec-20 06:05 PM <𝓕ermion#6024> Maybe a conflat? 15-Dec-20 06:05 PM I think the problem with conflat would be that you'd have stainless-stainless too soon for your 10th try or so 15-Dec-20 06:05 PM <𝓕ermion#6024> Huh? 15-Dec-20 06:06 PM if you reused the copper gasket 15-Dec-20 06:06 PM though I guess.. replacing copper gaskets is easy 15-Dec-20 06:06 PM unlike indium ones 15-Dec-20 06:06 PM <𝓕ermion#6024> Yeah that’s what I’m saying. 15-Dec-20 06:06 PM but then.. VCR/VCO? 15-Dec-20 06:06 PM <𝓕ermion#6024> Hmm? 15-Dec-20 06:07 PM VCR components would work too if conflat does, but even smaller? 15-Dec-20 06:07 PM <𝓕ermion#6024> Oh sure why not. 15-Dec-20 06:07 PM <𝓕ermion#6024> Idk I was thinking of a big flange but that was unspecified. 15-Dec-20 06:07 PM <𝓕ermion#6024> I wonder if you could use a Teflon gasket. 15-Dec-20 06:07 PM <𝓕ermion#6024> As long as it isn’t permeable by your gas. 15-Dec-20 06:07 PM <𝓕ermion#6024> I wonder how well a labyrinth seal filled with apiezon grease would work. 15-Dec-20 06:26 PM <𝓕ermion#6024> The reason why you wouldn’t use a conflat is that you need a lot of compressive force to get them to seal properly. 15-Dec-20 06:26 PM <𝓕ermion#6024> Indium needs less force to crush and flow. 15-Dec-20 06:26 PM <𝓕ermion#6024> https://www.mtm-inc.com/ac-20110520-demountable-cryogenic-seal-options.html 15-Dec-20 06:26 PM <𝓕ermion#6024> This is a nice reference. 15-Dec-20 06:26 PM <𝓕ermion#6024> Helicoflex, Mylar, and Kapton seem like great options. 15-Dec-20 06:26 PM <𝓕ermion#6024> @Dalai Llama 15-Dec-20 06:31 PM Ah, and if the temperature varies then the sealing will vary 15-Dec-20 11:27 PM Vacuum%20Hackers%20-%20Text%20Channels%20-%20general%20%5B513115950501855261%5D.html_Files/DSC_9008-311AF.JPG 15-Dec-20 11:27 PM who needs proper connectors when you have wagos? 15-Dec-20 11:27 PM not sure what their vapor pressure is but at least down to 6e-6 no issues so faar 15-Dec-20 11:56 PM VCR should be even better then CF in temperature extremes, regarding some articles I have read... 15-Dec-20 11:57 PM I was asking about heatshrink and stuff a few weeks ago 15-Dec-20 11:57 PM I have maybe 4 cm of small gauge heatshrink in 8E-9 torr right now. 3 day pumpdown 16-Dec-20 12:12 AM whats the reason for using heatshring though? 16-Dec-20 12:12 AM just ease of use? 16-Dec-20 12:12 AM i wanted to use kapton wrapping or just no insulation at all besides the laquer in the wires 16-Dec-20 12:20 AM @idmb What type of heatshrink? We bought some PTFE heatshrink recently, but we had not any chance to test it yet... 16-Dec-20 12:21 AM Cheap normal black stuff 16-Dec-20 12:21 AM Yes ease of use. I don’t intend to open the chamber more than a couple times a year so don’t mind waiting. 16-Dec-20 08:47 AM https://www.ebay.com/itm/20m-UHV-High-Vacuum-Bakeable-Isolated-Stranded-Copper-Wire-Cable-26AWG-0-12mm2/272433314484 16-Dec-20 08:48 AM teflon! 16-Dec-20 08:49 AM These teflon wires should be really good even though they are somewhat pricey 16-Dec-20 08:49 AM (With shipping included) 16-Dec-20 08:49 AM I usually just use kapton-coated copper wire in vacuum 16-Dec-20 08:51 AM This just saves you the trouble of wrapping wires yourself. 16-Dec-20 11:44 AM what's your fav coax? 16-Dec-20 11:44 AM for vakuum shit 16-Dec-20 11:44 AM bought different stuff with ptfe-ish dielectrics; will see if it works in a couple of weeks 16-Dec-20 11:54 AM Joined the server. 16-Dec-20 12:57 PM partyy 16-Dec-20 03:37 PM <𝓕ermion#6024> coax for use in vacuum? I use simple copper inner copper outer ut-85 16-Dec-20 03:37 PM <𝓕ermion#6024> nothing fancy 16-Dec-20 03:37 PM <𝓕ermion#6024> you can also use SPCP braided jacket cable if you want it to be flexible 16-Dec-20 03:37 PM <𝓕ermion#6024> but flexible coax and phase stability don't go together 16-Dec-20 03:37 PM <𝓕ermion#6024> if you're connecting from a hot to a cold thing you may want to use stainless inner stainless outer 16-Dec-20 03:37 PM <𝓕ermion#6024> or BeCu inner stainless outer 16-Dec-20 03:37 PM <𝓕ermion#6024> or silver plated stainless inner and stainless outer.... oooorrrrr.... cupronickel inner/outer 16-Dec-20 06:54 PM Joined the server. 16-Dec-20 10:07 PM ok will test thanks 16-Dec-20 11:22 PM wouldnt it be better to use braided enamelled wire? The teflon wont gas out but pumping down the braided and encapsulated conductor? 16-Dec-20 11:52 PM can I use it for microwaves? 16-Dec-20 11:52 PM yeah the inner conductor also makes me wonder 16-Dec-20 11:52 PM but I saw that kind of stuff in some rigs 16-Dec-20 11:52 PM I also have some meters of kapton based coax 16-Dec-20 11:52 PM but no practical experience with their performance 17-Dec-20 12:07 AM Hmm 17-Dec-20 12:07 AM I wonder how badly a 3layer kapton/polyimide "pcb" would outgas 17-Dec-20 12:07 AM As you could make a microstip and put it between two layers, so that it would not radiate 17-Dec-20 12:07 AM Tho a balanced line on double or single sided polyimide would likely be easier and outgass less 17-Dec-20 12:07 AM But unsure of hoof it would be on GHz 17-Dec-20 12:07 AM polyimidi is lossy, but I have not characterized how lossy. 17-Dec-20 12:07 AM RheinGoldHeavy or some other dude (maybe harmoninsturuments, if I spel lthat correctly?) on twitter did make some test units and measured them up to 40GHz 17-Dec-20 12:07 AM Reportedly very repeatable perfomance 17-Dec-20 12:07 AM and due to the lack of fiberglass wave, pretty stable impedance too 17-Dec-20 12:07 AM At a former employer we had first normal custom polymide runs for signals 17-Dec-20 12:07 AM But we had to make the copper so thin due to them leaking in heat to the cryogenic stuff that we later went with custom konstantan flex 17-Dec-20 12:07 AM More expensive, had to do custom runs 17-Dec-20 12:07 AM But it worked and was far less thermally conductive than copper, even with much wider and thus reliable traces. 17-Dec-20 07:26 AM yep also thought about kapton flex pcb stuff as an alternative 17-Dec-20 09:49 AM <𝓕ermion#6024> @rfs that works well for cryo. 17-Dec-20 09:49 AM Yep 17-Dec-20 09:49 AM <𝓕ermion#6024> delft circuits makes flat-flex cables 17-Dec-20 09:49 AM <𝓕ermion#6024> I might order a handful of them for my 3he probe 17-Dec-20 09:49 AM <𝓕ermion#6024> but will likely stick with SS/BeCu 17-Dec-20 09:50 AM ok 18-Dec-20 12:55 AM Uff i should go sleeping, nearly opened the roughing valve to the main chamber while the turbo is pumping 18-Dec-20 12:56 AM well after that you would at least be awake 18-Dec-20 01:16 AM Continuing the outgassing and sealing questions: Dis someone measure how much a thin metal coat can help? I have some home made feedthroughs that i coated in titanium from the inside covering the epoxy seal, they do seem to work better but im not sure if its worth doing it to all of them. 18-Dec-20 02:21 AM I don't have references at the moment, but when reading about my PVC chamber, I seem to recall coating with something like that was one technique to avoid really gassy or permeable plastics. 18-Dec-20 02:21 AM Even a simple sheet metal baffle I believe 18-Dec-20 04:07 AM ok, sounds nice! 18-Dec-20 04:59 AM hm so a bottle of argon in my basement is probably a bad idea, right? Asphyxiation in case of leak, and all that? 18-Dec-20 05:10 AM depends on many factors 18-Dec-20 05:10 AM I have a 20l Ar bottle here 18-Dec-20 05:10 AM that's like 4 m³ of gas 18-Dec-20 05:10 AM in a 32 m³room 18-Dec-20 05:11 AM hm that's a good point, didnt think about the actual volumes involved 18-Dec-20 05:11 AM measures basement 18-Dec-20 05:11 AM presumably something like nitrogen would be more dangerous, since it wouldn't settle below the ambient atmosphere? 18-Dec-20 07:12 AM No 18-Dec-20 07:12 AM Unless you have a huge dewar full of that and no convection 18-Dec-20 07:12 AM Air is about 80% N2 18-Dec-20 07:12 AM And if your gas bottle leaks completely empty in a short time you will hear that :D 18-Dec-20 07:12 AM I would be worried with something like SF6 or large amounts of liquid N2 18-Dec-20 07:12 AM But as @GigaSquirrel said,just calculate the volume at 1atm and in relation to your room volume 18-Dec-20 08:14 AM awesome, thanks! want to relocate some equipment to the basement... my garage shop is too damn cold in the winter 18-Dec-20 08:15 AM O2 monitors are a kinda fun project. Especially the part where you curse the heavens because you got one that's RF sensitive. 18-Dec-20 08:15 AM Fun in the sense that you start wondering how well maintained any of them are. 18-Dec-20 08:18 AM Isn't O2 sensing actually really hard because the only transition that has cheap, readily accessible lasers really weak? 18-Dec-20 08:23 AM paramagnetic o2 sensing is pretty good, but I think that's RF sensitive 18-Dec-20 08:53 AM Hmm, that makes more sense to me as a sensor, but I could have sworn that a past group mate was working on sensors that detect the A2<-X transition for use in ventilators (don't quote me on the excited state symmetry) 18-Dec-20 09:06 AM There are chemical O2 sensors as well but they have a fairly limited lifespan (2-3yrs) afaik 18-Dec-20 09:06 AM ME2-O2 sensors 18-Dec-20 09:06 AM Also O2-A2 apparently...but both of those only have around 2yr lifespans 18-Dec-20 09:56 AM lab canaries ! 18-Dec-20 09:56 AM why is this possible? 18-Dec-20 09:56 AM this ought not be possible 19-Dec-20 01:41 AM Manual valves since it's a quick and dirtx experiment 19-Dec-20 04:42 AM yo 19-Dec-20 04:42 AM what's a reasonable price for shell S3 RX 100? 19-Dec-20 04:42 AM It seems to cost ten times as much as shell S2 RX 100 19-Dec-20 04:42 AM S2 R 100 19-Dec-20 07:39 AM <𝓕ermion#6024> What’s the right way to vent a chamber to helium or argon or something below a bar? 19-Dec-20 07:39 AM <𝓕ermion#6024> Are there like... vacuum regulators? 19-Dec-20 07:39 AM <𝓕ermion#6024> Maybe a solenoid valve and a very tight impedance and you just flutter it some number of times 19-Dec-20 07:39 AM <𝓕ermion#6024> Until the pressure is reached 19-Dec-20 12:19 PM <𝓕ermion#6024> ah I want a mass flow controller 19-Dec-20 12:20 PM https://www.ebay.com/itm/Lot-of-2-Veeco-Veeco-ebi-PV-10-Vacuum-Piezoelectric-Flow-Valve/192969860549 19-Dec-20 12:20 PM These are good options as well, you can modulate the flow rate very well, but they do have a limited lifetime if operated with PWM 19-Dec-20 12:21 PM <𝓕ermion#6024> can they go half-open? 19-Dec-20 12:21 PM Yep 19-Dec-20 12:21 PM <𝓕ermion#6024> are they analog instruments? 19-Dec-20 12:21 PM <𝓕ermion#6024> I don't think I'd use PWM 19-Dec-20 12:22 PM They are pretty much as analog as you can get, you can modulate them with saw tooth waveform to achieve precise control 19-Dec-20 12:22 PM But if you just want to back fill and not to any specific pressure, even a needle valve will work just fine 19-Dec-20 12:24 PM <𝓕ermion#6024> naw I wanna go to a particular pressure. 19-Dec-20 12:24 PM <𝓕ermion#6024> I think I'm just worried about overshooting it 19-Dec-20 12:24 PM <𝓕ermion#6024> maybe I need an impedance? 19-Dec-20 12:24 PM What is this pressure? A few mTorr? 19-Dec-20 12:25 PM <𝓕ermion#6024> anywhere from 10 millibar to half a bar 19-Dec-20 12:26 PM Oh, yeah MFCs will work then, put a high vacuum valve between it and your chamber if it still needs to go down to high vacuum 19-Dec-20 12:33 PM <𝓕ermion#6024> oh would I rather use an MFC than a piezo valve? 19-Dec-20 12:33 PM <𝓕ermion#6024> I wonder about the dynamic range of the valve... 19-Dec-20 12:33 PM <𝓕ermion#6024> maybe the idea is to size the valve flow rate to the chamber size. 19-Dec-20 12:36 PM Yeah absolutely, and the piezoelectric valves are much faster, so you can stop precisely where you want it and not overshoot 19-Dec-20 12:36 PM Also, you can use pretty much any gas, whereas you should probably get the right type of MFC for your back fill gas 19-Dec-20 12:36 PM The downside is the relative high voltage needed to control them, and the fact that they are analog 19-Dec-20 12:37 PM <𝓕ermion#6024> so I can spend grant money on ebay, and the MFCs on ebay are maybe a hundred bucks 19-Dec-20 12:37 PM <𝓕ermion#6024> and I see some helium ones 19-Dec-20 12:38 PM https://www.ebay.com/itm/Tylan-FM-360-Mass-Flow-Controller-MFC-300-SCCM-Argon-Gas/123924556064 19-Dec-20 12:38 PM Argon ones are much cheaper 19-Dec-20 12:40 PM <𝓕ermion#6024> I guess a HE MFC and some VCR to KF fittings will get me there. 19-Dec-20 12:40 PM <𝓕ermion#6024> oh wow and ppt resolution 19-Dec-20 12:40 PM <𝓕ermion#6024> that's cool. 19-Dec-20 12:40 PM <𝓕ermion#6024> looks like some more crap I want. 19-Dec-20 03:36 PM <𝓕ermion#6024> what's the right way to join lengths of stainless tube? 19-Dec-20 03:36 PM <𝓕ermion#6024> like 1/4" tube 19-Dec-20 03:36 PM <𝓕ermion#6024> oh I guess it's just a union 19-Dec-20 04:13 PM A grad student told me once you could recalibrate those mfc's for anything. Does anyone know anything about that? 19-Dec-20 09:50 PM In many cases yeah 19-Dec-20 09:50 PM Problem with hydrogen and helium is the molecules are so damn small they have a tendency of breaking stuff 19-Dec-20 09:50 PM You can use regular MFCs with them, but they might not last 19-Dec-20 09:50 PM Also there's potential safety issues if you're mfc is not rated for hydrogen or oxogen ect 19-Dec-20 09:50 PM But no, you're completely right you can tune them for different gases with different thermal mass properties 20-Dec-20 10:55 PM Ooo what's this for? 20-Dec-20 11:25 PM I’m sure you’re more experienced than me but if I had my time again I’d stay away from deviceNet controllers. I ignored that advice and am paying for it now. It’s like a strange CANbus remix. 20-Dec-20 11:30 PM Ah nice 20-Dec-20 11:30 PM If you need any info or docs on cryo sem I have a lot 20-Dec-20 11:30 PM P47 20-Dec-20 11:30 PM Assuming it's stock jeol 20-Dec-20 11:30 PM You should replace it 20-Dec-20 11:30 PM They are a consumable and just wear out 20-Dec-20 11:30 PM They are pretty much one and done 20-Dec-20 11:30 PM Remounting them is rarely successful 20-Dec-20 11:30 PM If even a bit of the coating flakes off on the old ones you will get a ton of noise 20-Dec-20 11:30 PM New ones use a ito coated substrate instead of aluminum overcoat so they are fine 20-Dec-20 11:30 PM But if there's any non-conductive part exposed you will have problems 20-Dec-20 11:30 PM When are you seeing this glow? 20-Dec-20 11:30 PM Errrr 20-Dec-20 11:30 PM What were you looking at it through? 20-Dec-20 11:30 PM Ah 20-Dec-20 11:30 PM What type of glass is the window made from 20-Dec-20 11:30 PM ? 20-Dec-20 11:30 PM Ok so we have a slight x ray problem here 20-Dec-20 11:30 PM Any leakage? 20-Dec-20 11:30 PM What type of detector? 20-Dec-20 11:30 PM Well this won't let you do spectroscopy 20-Dec-20 11:43 PM This thread is not making me happy. 20-Dec-20 11:44 PM So beyond the safety issues of both radiation and dumping your scope to atmosphere 20-Dec-20 11:44 PM Eds is very low energy, like sub 1 kev in many cases 20-Dec-20 11:44 PM What kv were you running at when using the detector? 20-Dec-20 11:44 PM It has the potential to be a lot higher leakage rate due to the response of the detector at lower energy x rays 20-Dec-20 11:48 PM [wince] Please keep your flesh far away from this window. 20-Dec-20 11:48 PM No, you may not be able to. 20-Dec-20 11:48 PM Yeah I'm funranium 20-Dec-20 11:50 PM This was a terrible time to look in on the server shortly before going to bed with work in the morning. I will leave you in @AdamMcCombs capable hands. Giving SEM/TEMs a funzies x-ray port is generally regarded as a no-no. 20-Dec-20 11:50 PM The thing you are doing is the exact reason why electron microscopes are required to be registered in the State of CA. 20-Dec-20 11:52 PM Yeah, but your capability to measure them in low energy is not 20-Dec-20 11:52 PM They’re less predictable than firearms 20-Dec-20 11:56 PM I mean I'm glad to hear that it's facing a concrete wall 20-Dec-20 11:56 PM But at the same time there's a good chance if there's high energy leakage byou can measure, there's also low energy leakage you can't 20-Dec-20 11:56 PM Not really 20-Dec-20 11:56 PM More like x rays can generate more xrays 20-Dec-20 11:56 PM And as you reach the outside of the glass, there's potential a pretty noticeble amount of low kv, but still hazardous, x rays being generated 20-Dec-20 11:56 PM This is why small leaks in microscopes, especially SEMs, are treated pretty seriously 20-Dec-20 11:56 PM To be clear I'm not saying you can't do this 20-Dec-20 11:56 PM I've run glass windows on systems before 20-Dec-20 11:56 PM But at the same time there was shielding in place behind the glass 20-Dec-20 11:56 PM So this is one of those cases where it's a it takes more work to safely get to yes 20-Dec-20 11:56 PM And I do think the long exposure pictues of inside the chamber are very cool, but just not something I would expose my self to an unknown dose over either 20-Dec-20 11:56 PM Not really 20-Dec-20 11:56 PM If your beam energy x rays is detectable on the outside, then lower energy ones are very likely present 20-Dec-20 11:56 PM If beam energy ones aren't, then lower energy ones are probably not 20-Dec-20 11:56 PM Unfortunately I have to go, phone battery is at 1% 20-Dec-20 11:56 PM But yeah that's another concern in these types of systems 20-Dec-20 11:56 PM Let's talk about this more later 21-Dec-20 07:53 AM That wasn't unexplained fear. That was a professional assessment before I needed to go to bed. Your borosilicate window will provide near to no attenuation of the x-rays from your SEM. We normally refer to the modification you've made as "Shielded port replaced by quartz waveguide" in the accident investigations. Luckily, in your case, you haven't made a modification to a system someone else uses that causes unwitting injury to them, as usually happens when some engineer does this to a coating chamber and then roasts the coating tech. @AdamMcCombs is correct that if you can detect the higher energy x-rays in a situation like this, the lower energy band is there as well and likely at 2-3x the flux. This is unfortunate because the 5-20keV x-rays are irritatingly hard to detect with any accuracy. It is doubly unfortunate because that's the band with the highest rate of skin deposition. "Radiologist Hands" used to be a distressingly common form of radiogenic dermatitis from people taking repeated erythema doses to the hands while handling poorly shielded x-ray sources with soft x-ray leakage. The only good news here is that the soft x-rays attenuate quickly in air. Keep your hands & eyes at least 10cm away from the window and you'll be fine. This, incidentally, is the dose measurement distance for assessment of device safety in Germany. As an almost unnecessary aside, your modifications do constitute a defeat of approve safety design features under the German X-Ray Ordinance. But as most people here are ignoring their respective countries & states' local ordinances... . Just know what you have done and the liability you've invited. 21-Dec-20 07:53 AM No, that is not how the law is written. It is strictly exposure based. Your intent doesn't matter. 21-Dec-20 07:53 AM As long as you are under 1 µSv/hr at 10cm, you're fine and exempt. Measuring that to prove it, is much harder. 21-Dec-20 07:53 AM Note that it doesn't matter what energy. Just 1 µSv/hr at 10cm. 21-Dec-20 08:02 AM how would one do dosimetry on that energy range? 21-Dec-20 08:02 AM ion chamber? 21-Dec-20 08:03 AM Most ion chambers get a bit iffy under 15keV. 21-Dec-20 08:03 AM Your exposure is irrelevant. Its emission is what matters. 21-Dec-20 08:03 AM Except you lack any way to know what that dose rate actually is. You are operating in the dark. 21-Dec-20 08:07 AM throw a webcam and some lead on there and call it a day 21-Dec-20 08:08 AM ""Radiologist Hands" used to be a distressingly common form of radiogenic dermatitis from people taking repeated erythema doses to the hands while handling poorly shielded x-ray sources with soft x-ray leakage." The reason this happened is because they had no instrumentation either other than "when the skin goes pink, it's 500R". 21-Dec-20 08:08 AM Do not use yourself as a direct reading instrument. 21-Dec-20 08:16 AM Admittedly I have limited knowledge about x-rays. But isn't there a way to take a worst case estimate assuming that the window is not absorbing any radiation and using the beam energy and current to calculate the x-ray emission. That way one could probably say that below a certain beam energy/current a exposure above 1 µSv/hr at 10cm is not possible, if I understand things correctly 21-Dec-20 08:46 AM It's an annoying calculation that isn't exactly accurate and fails to take into account geometry issues. For everyone's handy reference, the old equation for determining the fraction of incident electron energy available as Bremsstrahlung is f = E x Z x 10-6, where E electron energy (in keV) and Z is the atomic number of your target. You then multiply that times the total power on target, peak voltage (in kV) times current (in Ma). Divide by 3 because that's the average for peak power. From there you do inverse square law, assuming isotropic emission from the target (which it isn't), and convert to the units of your choice for dose. 21-Dec-20 08:46 AM This has no filtration effects. This is your worst case. 21-Dec-20 09:04 AM thanks @funranium ! I'm still a little in the dark myself. I've been working with CRTs quiet a lot and have used some with below-nominal anode voltages to get more deflection. Do I need to be any worried about possible emissions of lower energy bremsstrahlung? At least I'm pretty sure the glass of any display crt (i.e. PDA oscilloscope CRT/TV CRT/projection CRT) is shielded, i.e. using leaded glass and can be considered safe whenever nominal anode voltage and current are not exceeded? 21-Dec-20 09:07 AM Is your glass a borosolicate window without other attenuating dopants? You are correct that your old CRT's (well, almost all) are properly shielded, leaded glass which is what allows them to be sold as generally licensed consumer products. The manufacturer was required to do the design work to insure absorption. 21-Dec-20 10:48 AM Reads like a situation that wouldn't have come this far in person. I think both of you @george and @funranium have had reasonable intent. I'll try my best not to be part of either party and would really like to encourage both of you to get this settled. You both were cordially invited to message me if you like. 21-Dec-20 11:04 AM No need. It's resolved. 21-Dec-20 11:09 AM Did it really have to come to this? 21-Dec-20 11:09 AM I assume he did get banned, judging from the fact that his messages from the past 7 days are gone from the server 21-Dec-20 11:11 AM I'm a bit disappointed honestly 21-Dec-20 11:11 AM This is a really nice place for reasonable people to have reasonable discussions, but I never thought the discussion got out of control here in the public channel 21-Dec-20 11:11 AM Of course, I can't see any of his comments now, and there's no way to judge if it was beyond what was deemed acceptable 21-Dec-20 11:12 AM I know Georg for some time and yes the critics are justified 21-Dec-20 11:12 AM But he is carefull and knows what he is doing. He most certainly is not the person who is careless with such stuff. I mean this channel is also about home projects. And if you really need to ban every one who does not strictly follow every legal regulation you have to ban nearly everyone 21-Dec-20 11:21 AM Perhaps a large part of this did play out in PMs. But is that a good justification for banning someone in a public channel? 21-Dec-20 11:21 AM And we don't know for sure his x-ray window on the SEM is that dangerous. I recall his comment that he cannot accurately measure dose rate at 10 cm from the window, but justified it by saying the current and energy on target is so low that there is simply not enough energy to cause danger, especially with short exposures 21-Dec-20 11:21 AM I'm 100% positive that many fusors and other high voltage devices people on this server have built will emit far more x-rays than a SEM with a side window attached 21-Dec-20 11:26 AM Not to mention lasers, HV etc. 21-Dec-20 11:30 AM Giving good advice and promoting good safety practice is important, but perhaps we shouldn't try to apply all the latest industrial standards on something that is clearly not a commercial product and does not endanger the general public 21-Dec-20 01:38 PM Igh 21-Dec-20 01:38 PM Ugh 21-Dec-20 01:38 PM Wtf 21-Dec-20 01:38 PM The mods here are ridiculous 21-Dec-20 01:38 PM "let's just change history" 21-Dec-20 01:38 PM So much for actually caring about the person's safety 21-Dec-20 01:39 PM Deleting the messages is weird, imo 21-Dec-20 01:39 PM As now nobody has context for anything. 21-Dec-20 01:41 PM This has happened before 21-Dec-20 01:41 PM Those were also cases of people asking legitimately for feedback, or just having discourse 21-Dec-20 01:41 PM Some really interesting and productive people have been banned, as is obviously the case today 21-Dec-20 01:41 PM It's stupid enough because I also probably would have done the same thing with the DRIE reactor I'm building if not for reading the backlog today 21-Dec-20 01:41 PM Glad I did it before the Nazi's came through and burned the evidence 21-Dec-20 01:41 PM So @GigaSquirrel is your quartz ICP tube leaking x-rays such that you're next on the ban list? 21-Dec-20 01:41 PM Or is not talking about safety the best safety against banning? 21-Dec-20 01:41 PM Please send me his contact in direct message, I'd like to invite him to another server 21-Dec-20 02:01 PM I asked hi,m 21-Dec-20 02:09 PM Implying that anyone on this server is a Nazi is a very good way to depart this server. That's your warning. 21-Dec-20 02:30 PM DRIE you say? hmmm... 21-Dec-20 02:30 PM Yep 21-Dec-20 02:31 PM ill pm you later. 21-Dec-20 03:21 PM @funranium is likening it to Fahrenheit 451 less offensive?