#qi-hardware IRC log for Monday, 2014-12-08

sb0whitequark, where did you get your vacuum gear from?01:36
whitequarklvtcshop on ebay05:57
whitequark$110 for gear and $85 for delivery approx05:58
whitequarksb0: ^05:58
sb0the pump?!06:02
sb0just the clamps and pipes, right?06:03
whitequarkthe pump was about $250 in RU06:14
whitequarkand almost free delivery06:14
whitequarkturbo pump that is. rough is another $10006:14
sb0where did you find those?06:15
whitequarkchipmaker.ru, avito.ru. local craigslist-like things06:15
sb0which one exactly?06:16
whitequarkturbo pump from chipmaker, rough from avito06:16
whitequarkrough you can find on ebay just as well, there are plenty of these noname pumps there06:16
whitequarkit's an air conditioning pump basically06:17
sb0yeah but all I find on ebay for roughing pumps is $400 min.06:17
whitequarklemme show you06:17
sb0or it's bids, which I never win and piss me off06:17
whitequarkhaha, I won another bid for a turbo pump (from working equipment) for $250 too06:17
whitequarkwould have never thought that I do. also ext250hi06:18
whitequarkso now I have two06:18
sb0and then shipping is another $600 ...06:18
whitequarknot really, ground was $12 and I used a remailer with a freight kinda option06:19
whitequarkso it offset me about $8006:19
sb0so it was a russian vendor?06:19
whitequarkno, continental US06:19
whitequarkthe remailer airmails it to germany and then to russia, which takes about a month and somehow inexplicably much cheaper06:20
sb0http://www.ebay.com/itm/Pfeiffer-Balzers-TPH330-Turbo-Molecular-Vacuum-Pump-/281395178055 is the typical offer I find06:20
sb0$1,850 + $305 shipping to HK06:20
whitequarkyeah, you need to look harder. set an alert and let it sit there for a few months06:21
sb0well, the typical "good" one. most are like $600006:21
whitequarkso http://www.ebay.com/itm/BOC-Edwards-EXT-250-Turbomolecular-Pump-/161507454254?pt=BI_Pumps&hash=item259a982d2e06:21
whitequarkused, for $50006:21
sb0no controller?06:21
whitequarkcontroller you can get for $75 or so, if you're lucky06:22
whitequark(mine from chipmaker was with controller as well)06:22
sb0I'm *never* lucky on goddamed ebay, and I fucking hate it06:22
whitequarkget it while it's hot06:22
whitequarkexdc160, even. more powerful than mine06:22
whitequarkalthough you don't really need those 160 watts06:22
sb0"Ships to: United States". so I need to ship it to a friend, who forwards it, etc.06:23
whitequarkor remailer06:23
whitequarkif you want to win cheap auctions, that's the only way06:23
whitequarkmy other wins include: active pirani gauge for $75, active inverted magnetron for $4806:24
sb0also, "untested". isn't that synonymous for "broken" on ebay?06:24
whitequarkhave you seen what's inside that controller? I have, I disassembled it06:24
whitequarkit's dumb as hell. it has six FETs and a bog-standard TI BLDC controller06:24
whitequarkthere's no way you're going to kill it, unless you're completely incompetent06:24
sb0still a pain to fix, especially if those FETs are obsolete or unsourceable for some other reason06:25
whitequarktypical IR FETs06:25
whitequarkand it's not really going to be broken, it's just, you see06:25
whitequarkif they say "working", they have to process warranty and/or returns06:25
whitequarkadditionally not many people have the ability to test the gear06:26
whitequarkso maybe for other stuff, yes, but for vacuum untested usually means "I don't have the ability to test this and/or not want to bother"06:26
whitequarksince it lowers price 3-4x, I'm totally fine with it, because you can just buy another if it's broken :p06:26
whitequark"tested" inverted magnetron gauges for $40006:27
whitequarkI could buy almost eight "untested" ones for that, obviously it makes economic sense06:27
sb0what remailer did you use?06:28
whitequarkI think they would even send to non-RU, altough their process is tailored to RU. express delivery to the door, customs handling, etc06:29
whitequarkfairly cheap too06:30
sb0I also wonder if those second-hand turbopumps could be contaminated with oil from the previous roughing pump06:34
whitequarkwell, significant contamination will probably be visible06:35
whitequarkworst case, you'll have to reassemble and clean it, which, contrary to what the pump vendor wants you to think, is completely doable06:36
whitequarkafaik people usually boil the internals in ether to remove oil06:36
whitequarksb0: http://www.ebay.com/itm/2Stage-5CFM-Rotary-Vane-Vacuum-Pump-For-R410-R134-Refrigerant-Air-Condition-HVAC-/201236473761?pt=BI_Pumps&hash=item2edaa0e7a106:37
whitequarkthis is the rough pump I was referring to06:38
whitequarkalthough if your turbo pump has a drag stage, like edwards usually does, you don't need 2stage rotary vane06:38
whitequarkmine is 1-stage and that totally suffices. in fact anything under 500 Pa will do06:38
whitequarksb0: http://www.ebay.com/itm/3CFM-Rotary-Vane-Deep-Vacuum-Pump-1-4HP-HVAC-AC-Air-Tool-Freon-R410a-R134-etc-/400818965677?pt=LH_DefaultDomain_0&hash=item5d52ac0cad06:39
sb0ah, I see, you got one for refrigeration stuff06:39
whitequark$21 :p06:39
sb0you probably get a lot of oil backstreaming with that, though06:39
whitequarkdo you mean like oil vapor?06:40
sb0do you use the original oil, or did you replace it with something better?06:40
whitequarkpossibly. I will see it better when I get my gauges06:41
sb0and I read that this oil vapor tends to stick to surfaces and create a mess in UHV06:41
whitequarkyou generally have to bake the UHV equipment to remove water, this also helps with oil06:41
whitequarknot to mention turbo pumps can actually pump oil vapor quite efficiently06:41
whitequarkI used original oil, however before putting it in, I disassembled the pump and cleaned it06:42
sb0yeah...  but I heard other opinions (from physicists) about what happens to oil when baking06:42
whitequarkthere were some oil-like residues inside which was green, smelly and muddy06:42
whitequarkas a bonus point I now know how a rotary vane pump looks inside :p06:42
sb0so much of this stuff is in the US...06:43
whitequarkI'm sure you can find a rotary vane pump locally06:44
sb0hmm, I'd rather try to find a scroll pump06:45
whitequarkthey're bloody expensive06:45
whitequarkdo you really need one?06:45
sb0oil is messy06:45
whitequarkmoney is scarce06:45
sb0especially in UHV06:45
sb0http://www.ebay.com/itm/Busch-Fossa-18-F018-Scroll-Vacuum-Pump-/281395168490 not worse than the typical turbomolecular pump offer06:46
whitequarktry meeting your local scientists, sometimes the lab has an upgrade and they throw out old equipment en masse06:47
sb0yeah, that's how I got my previous stuff already :)06:47
whitequarkI wouldn't pay $2k for a turbo pump :p06:47
whitequarkooooo, my pirani gauge just arrived at the post office.06:49
whitequarkor maybe that was something else06:49
whitequarkcrap, it was.06:49
whitequarkHe said the repair on this unit cost $500-700. But he said its simple for someone who knows about these. Selling as-is thanks!06:50
whitequarkGOD BLESS!06:50
whitequarknot very inspiring06:50
DocScrutinizer05whitequark: what the heck are you doing? Vacuum, iverted magnetrons (whatever that is) :-o    .oO(???)08:06
whitequarkinverted magnetron gauge, it's a vacuum gauge for under 10^-1 torr of pressure08:07
whitequarkit's not the same magnetron as in a microwave oven in that it's not self-oscillating (afaik)08:07
whitequarkthe "magnetron" part comes from two strong magnets which confine any plasma that exists near them to a small ring region08:08
whitequarkthe gauge works by lighting up the plasma and measuring the current that flows through it. the less current, the less pressure08:08
whitequarkbetween 10^1 and 10^-1 it's a pirani gauge. that one's simpler. you have a resistor bridge, one of which is inside the chamber08:09
whitequarkthe less pressure there is, the less heat is convected/conducted by the gas08:09
whitequark(tip: if you want to convert torr into something more manageable, apt-get install units)08:09
sb0is that better than Bayard Alpert gauges?08:10
DocScrutinizer05fine fine, but WHAT for do you need that stuff?08:10
whitequarkhot filament ionization? yes, definitely08:10
whitequarkionization gauges tend to be fragile as heck with the glass enclosure, and generally you can get shit deposited on the filament08:10
DocScrutinizer05related to your 5 bazillion Volt shortwave function generator?08:10
whitequarkby your process08:11
whitequarkwith inverse magnetron, you can disassemble it and clean the anode with rubbing alcohol08:11
whitequark(and it's generally less susceptible to drift from deposited crap)08:11
whitequarkDocScrutinizer05: yes, the function generator would be for a quadrupole mass spectrometer08:11
DocScrutinizer05ahaaaaa mass spectro08:12
whitequarkbut I want other things too, like plasma etching and thin film deposition08:12
DocScrutinizer05now we're talking :-)08:12
whitequarkmass spectro is very useful for that!08:12
whitequarkhow'd you control the process otherwise?08:12
DocScrutinizer05nfc, never thought about it08:13
whitequarkwell, that's how it's done in the industry :p08:13
DocScrutinizer05except for "make a copper wire explode and enjoy the funny color deposits on all the stuff in vicinity"08:13
whitequarkthin film deposition I actually don't even need turbo pump for08:14
whitequarklet me show you this video08:14
DocScrutinizer05funny that you mention gas flow cooling a resistor08:14
DocScrutinizer05I just said about the same, in a completely different context, for determining wind speed08:15
whitequarkyep, it's also used in anemometers08:15
whitequarkvery cheap, fairly reliable, somewhat precise08:15
whitequarkDocScrutinizer05: https://www.youtube.com/watch?v=c4Sic1DRXJI08:15
DocScrutinizer05hehe, and included in Neo90008:15
DocScrutinizer05since we got a hygrometer that has a 10,W internal heater and a 14bit thermometer built in08:16
whitequarkthere's that eink tablet for outdoor enthusiasts08:17
whitequarkpacked to the brim with sensors08:17
DocScrutinizer05ooh that one, think I heard about it already08:17
whitequarkI actually think I heard of it from you08:17
DocScrutinizer05isn't earl a dog?08:17
whitequarkno clue08:18
whitequarkso for thin film, I don't even need turbo pump, just a pair of strong magnets, some DC source and argon08:18
whitequarkno one sells broken microwaves anymore, they're not valuable enough D:08:19
DocScrutinizer05umm except for the VHF/UHF transceiver (GMRS, PMR446, UHFCB) and AM/FM/SW/LW/WB  I think Neo900 is on par :-D08:20
DocScrutinizer05but then we got a real modem08:20
DocScrutinizer05cellular modem08:20
DocScrutinizer05wtf is a "glove friendly capacitive touchscreen"?08:22
DocScrutinizer05whitequark: thought you were suggesting the earl had anemometer08:23
whitequarkI think it had08:23
whitequarkglove friendly touchscreen, I think some old touchscreens did not work with gloves08:23
whitequarkmost modern ones do anyway08:23
whitequarkhm, doesn't seem to have an anemometer08:25
DocScrutinizer05I wonder how they do that08:25
whitequarkmaybe it was an earlier "stretch goal" or something?08:25
whitequarkI remember it quite well08:25
DocScrutinizer05or *if*08:25
DocScrutinizer05now that you mention it, yes, I think I seen sth like that and thought "duh, you need to hold that board directly in wind direction or you will not meter the real windspeed through that hole"08:26
whitequarkI think it was expandable or something08:26
DocScrutinizer05still the sensor would be pretty directional08:27
DocScrutinizer05iow there's one postition 90° off the right one, where the anemometer will read zarro even when hurricane hits you08:28
whitequarkit helps to not be dumb08:29
DocScrutinizer05but well, wind speed is in 12 steps or sth, and not very steady either, and user has a certain idea where from it blows ;-)08:29
DocScrutinizer05iow you wouldn't need highly exact readouts anyway08:30
DocScrutinizer05"rotate 180° slowly, device will calculate correct maximum and wind direction"08:31
DocScrutinizer05Neo900 will not be able to do that, data acquisition rate is way too low for that08:32
DocScrutinizer05thanks to thermal "inertia" of the sensor08:32
DocScrutinizer05I think new ones son't either08:48
DocScrutinizer05that YT video has the best subtitle at the very end :-D08:48
DocScrutinizer05alas for really decent laser you need convex mirrors08:49
whitequarkwell, this guy considers a MOT an acceptable power source08:50
whitequarki bet he'll make do with this mirror08:50
DocScrutinizer05it kinda will work, sure08:50
DocScrutinizer05but convergence and beam diameter will be *eeeew*08:50
DocScrutinizer05well, I'm looking forward to the next part of this enterprise08:51
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