#homecmos IRC log for Saturday, 2013-08-24

diginetSync__: HOW DO YOU AFFORD THESE!?!?!? lol00:19
diginetand more to the point: where can I get one?? lol00:19
Sync__on that note, got two more ballscrews00:20
Sync__just hunting down two stages00:20
diginethow much was the turbo?00:21
diginetwow. . .that's like $11000:22
diginetwhere? ebay?00:22
diginetare they somehow cheaper in Eurozone?00:23
diginetwell, is it the sort of thing where cheap ones are going to need all kinds of servicing?00:23
Sync__I'm just in my exam phase and became pro at finding good deals on ebay00:23
Sync__it depends00:23
Sync__it runs, which is good00:23
Sync__but has loud bearings, not a huge deal for a hobbyist00:24
Sync__if so the cartridge is pretty cheap anyway if they finally let go and don't kill the rotor00:24
diginetwhat type bearings does it use? magnetic?00:24
Sync__no, magnetic bearing pumps are pretty rare00:25
Sync__or rather rare that cheap00:25
Sync__it just uses plain oil lubed bearings00:25
Sync__it's not too fast, 50000 rpm or something00:25
diginetthat's. . .it? wow00:25
diginetso I'm looking through ebay, the "cheap" ones seem to mostly lack controllers00:25
diginetthat a problem?00:26
Sync__you can build your own, sure but I'm not a friend00:26
Sync__I'm just going to buy the controller for mine00:26
diginetI mean, is it a problem as in can you realistically build your own00:26
Sync__yes it's not hard00:27
diginetI mean, are there like. ..instructions online?00:27
Sync__learn how electric motors work00:27
Sync__somebody made a driver for tph055s on fusor.net00:28
diginetI know how they work, but surely there's more to it than just a regular motor controller00:28
Sync__not really00:28
digineturgh, fusor.org00:28
diginetlove hate00:28
diginetI'm so bloody sick of that kid00:28
diginetthe one that keeps pandering so hard because he built a "fusion reactor" at 1600:29
Sync__oh that guy00:29
diginettechnically, nothing he says is false, he's just I dunno00:29
Sync__yeah total dickhead00:29
diginethe talked to the president about "his ideas for the future in energy"00:29
diginetsomehow, I somehow doubt someone who thinks making a glorified purple light bulb is the right person to talk to00:30
Sync__building a fusor is not even an engineering challenge anymore00:30
diginetno, it's a "having rich parents challenge"00:30
Sync__not even that00:30
Sync__you can build one for under 2-3k00:30
diginetmost teenagers don't have that kind of disposible income00:30
Sync__uh huh00:30
diginetokay, well I didn't, nor did anyone I know00:31
diginetanyhow, what really pisses me off are the people getting free rides into MIT00:31
diginetHURR DURR they used the word "fusion" they must be geniuses!!!11!!1one!!!00:31
Sync__well it's not like I'd have that lying around but taking your time that is not a lot of money00:31
Sync__but most of the guys there are pretty good00:32
Sync__but it really depends on the pump and which kind of motor it has00:32
diginetyeah but the admin last time I was there did nothing but whore that kid out00:32
Sync__well it is a feat but nothing special00:32
Sync__you can today buy everything you need off ebay for reasonable prices00:33
diginetI suppose so, but it just bother me because it's so superficial. It bothers me that MIT admssions, who should know better, are going to admit the kid who built a machine which makes pretty purple lights and contains the words "fusion" and "nuclear" over someone more deserving00:33
Sync__and if you are willing enough you can cheap out everywhere00:33
diginetmmmmmmmmmmmmmmmmmmmmmmmmmmmm neutrons00:33
Sync__I could care less about a mit admission00:33
diginetMIT is pretty obnoxious I suppose, it's filled to the brim with charlatans00:34
diginetgranted, there are some useful things you can do with them, like neutron activation analysis, funny how you never see fusortards talking about that (well, the mediawhore-ish ones anyway)00:35
Sync__some of them are into that00:37
Sync__I have the equipment here for all of that00:37
Sync__but I just needed a conflat sealed turbo that I could use as a throwaway pump00:38
diginetyeah I know, I'm just saying it's funny how the people who of themselves as the next Einstein aren't actually talking about the useful things a fusor can do00:38
Sync__yeah I do understand00:39
Sync__I did not really get the hype about him00:39
diginetwhat all do you need to put together a vacuum system? roughing pump (easy/cheap), turbo and/or difussion, bell jar, vacuum plate, gaskets/o rings, what else?00:40
diginetcan you use aluminum or do you really need 304 stainless?00:40
Sync__well it depends on what you want to do00:40
diginetwell, ideally, a DC sputtering set up00:40
diginetbut maybe vacuum evap00:41
diginetoh, a feedthrough00:41
Sync__well that's easy and cheap00:41
Sync__yeah basically you'd want a forepump, high vac pump, recipient and some valves00:41
Sync__the problem with sputtering is that you might be generating xrays00:42
Sync__so you'd want stainless to contain them00:42
Sync__but apart from that nothing wrong with a belljar or Al00:42
Sync__just be sure that you get an alloy without high vapor pressure contents00:42
Sync__something like AlMg3 does nicely00:42
diginetalloy for what? the sputtering?00:43
Sync__no for the recipient00:43
diginetohh, so I couldn't use a Si wafer?00:43
diginetI thought Mg was a big no-no when it came to vacuum stuff?00:43
Sync__recipient - vacuum vessle00:43
diginetoh right right right, duh00:43
diginetstill though, you can use Mg?00:44
digineteven in alloy?00:44
Sync__at pressures relevant for dc sputtering or thermal evap, certainly00:45
Sync__if you have fears, use AlSi alloys00:45
diginetnow, I know sputtering needs argon flow with a pressure of ~100 mTorr, how low do you need to get it before you purge with argon?00:45
Sync__no good for much more than 10-6mbar but well00:45
Sync__as low as you can get preferrably00:45
Sync__but it is not that important at our scale00:46
Sync__because you really have to get a feel for the process in your own system00:46
Sync__you also want a throttle valve in the high vac line00:46
diginet10 millibar is like 7 torr though?00:46
Sync__I'm just too lazy to write the ^00:47
Sync__it's to the minus sixth power00:47
diginetOHHH ahahaha00:47
diginetokay I was really confused lol!!00:47
Sync__I'm sorry, it's like 3 in the morning here00:47
diginetoh you don't need to apologize haha00:48
diginetyou know, surprisingly, a turbo set up might actually not be that much more expnesive than a diffusion00:49
diginetnot to mention, the cost of oil, and the massive benefits of turbos00:49
Sync__you really really want a turbo setup00:49
Sync__diff is a no00:49
Sync__just a no00:50
Sync__well, there is that but it is just a hassle to deal with00:50
diginet could a scroll pump be used for roughing?00:50
Sync__and at some point you will burn the oil even if you use dc407 and such00:52
Sync__just a hassle00:52
Sync__yes sure if you do not mind paying 2k for a working scroll00:52
diginetwhat about ones from cars?00:53
diginetI see them for $100 and lower all the time00:53
Sync__~dc704 even00:53
diginetthey're used in newer AC systems in cars00:53
diginetbecause of the compactness and quietness00:53
Sync__a scroll compressor will not work00:53
diginetwhat's the difference?00:54
Sync__the end seal and the lubrication scheme00:54
diginetwould that work?00:55
Sync__just get any used two stage rotary00:55
diginetdo those have oil contamination problems?00:55
Sync__that looks good00:56
Sync__but a scroll will need regular maintainance00:56
Sync__just get a cheap two stage00:56
diginetoooooooooooh, okay no thank you00:56
diginetso two stage rotary + turbo = no contamination I assume?00:57
diginetturbos are awesome :)00:57
Sync__I also find zero information on that kind of scroll00:58
Sync__you get some oil backstreaming00:58
Sync__but for us it is totally acceptable00:58
Sync__you will probably see it on the RGA but really, for a home setup it is more than you'd need00:59
Sync__I mean I *do* have a edwards ex10 scroll but yeah01:00
Sync__gotta keep everything really clean to benefit from that01:00
Sync__and your times neccessary to spend with the equipment are significantly longer with diffs because they'll need to heat and cool01:10
Sync__they have their places in applications there you need to remove large amounts of dirty gas01:11
--- Sun Aug 25 201300:00

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