azonenberg changed the topic of #homecmos to: Homebrew CMOS and MEMS foundry design | Wiki: http://homecmos.drawersteak.com/wiki/Main_Page | Repository: http://code.google.com/p/homecmos/ | Logs: http://en.qi-hardware.com/homecmos-logs/
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<Noxz> epoxy impreg'd borosilicate microfiber filter is what the edwards oil mist filter states
<Noxz> also, it appears they have a decently long life and can recirculate/drain fairly easy
<Noxz> so, may be worth just buying a commercial one
<pie_> borosilicate microfiber
<pie_> fancy as fk
<pie_> thats glaasss
<Noxz> epoxy impreg'd
<Noxz> borosilicate fiberglass, more or less, yeah
<Noxz> the idea of the diaphragm pump backing a vane pump is interesting to a point
<Noxz> removes condensate and such
<Noxz> no idea what temp that oil is though, for what else may be pulled out
<sync> is it really that fancy pie_?
<pie_> idk
<Noxz> heh
<sync> it is technology that is in most household waterfilters
<pie_> oh.
<pie_> ok then relatively maybe it isnt that fancy
<Noxz> some vacuum cleaners too, I bet, for their hepa
<pie_> but maybe its still overall fancy :O
<Noxz> one idea was to simply source out vacuum filters
<sync> ime hepa filters are foams
<Noxz> I mean,, that's what it is
<Noxz> from what I read HEPA is only an air throughput/particulate size standard
<Noxz> I could be wrong though
<sync> the large area filters could be glass, but I suppose most of them use some kind of fleece
<Noxz> I find glass fiber hepas
<sync> sure
<sync> rotary vanes get hot but not incredibly hot
<sync> maybe 60°C
<sync> maybe more, never pointed my thermal camera at one
<Noxz> the idea on where I was going for that is if the diaphragm backing pump got down to 5 torr or less, what would come over from the oil based on it's temp
<Noxz> depends what you work on, but certainly water
<sync> I would not do that
<sync> it is too much work for no benefit
<sync> if you want to get rid of the water after the pump sat for a while close the inlet valve and let it pump with the ballast open for a few hours
<sync> but if you only pump air from a chamber there is not much water that is going to accumulate there
<Noxz> that seemed to be the main benefit of these 'combo' pumps
<Noxz> was condensate removal of the vane's oil
<sync> yes, I have a chemical pump that works like that, but as I said, you should segregate your vacuum pumps to the duties they will serve
<sync> if you pump a lot of solvents a membrane pump is useful
<sync> if not, you just waste power
<Noxz> I will be, on the chemistry side of things
<Noxz> there is a DC pump available that can slow down (use less power) when higher vacuum is attained
<Noxz> that's an idea..
<pie_> INFINITE POWERRR
<sync> or you just use a vfd
<sync> all my rotary vane pumps have 3 phase motors, I threw the capacitor motors away nobody needs those
<Noxz> heh
<Noxz> simple enough to replace the motors
<Noxz> would the oil need a certain RPM though?
<Noxz> I can imagine the seal breaking from oil sliding out of place if too slow
<sync> not really
<sync> the pumps at work are programmed to run at 15Hz at the low end
<sync> I have not done this at home tho because you need an adequate buffer volume or the pressure controller oscillates a lot
<Noxz> ah
<pie_> is there such a thing as a "wave pump"? just some random asspull idea i just had, where you put a valve in the antinode of a standing wave or something like that
<pie_> damn you harold!
<pie_> i could have made millions!
<pie_> doesnt look like anyone ever used it though
<Noxz> if I use the vane pump for chemistry stuffs as well, then the chemically resistant diaphragm would be beneficial..
<Noxz> as a backing pump though? like the one thing ti would do is ismply minimize oil changes
<Noxz> a good oil mist filter still wanted at the input side
<sync> well, oil filters only work so well
<Noxz> right :/
<pie_> dry pumps 4 life :x
<sync> only if you cycle them rarely
<Noxz> all I know is I am getting a somewhat decent vane pump... and I still want to do chemistry stuffs
<sync> just get another one
<Noxz> vane?
<Noxz> diaphragm?
<Noxz> and dont mix it with the vane?
<Noxz> the idea there is if the SEM/mass spec/WHATEVER.. the vane pump, would benefit from the diaphragm, and wont harm the chamitry experiments, why not just rig them together to make less maintenance on the vane
<sync> meh, you still don't get the point it seems
<pie_> sync, try capital letters :D
<Noxz> my point is wanting to get low pressure for chemistry stuff.. you say to get another pump... but I also want to have low maint on the diaphragm pump if I can, thus maybe requiring another pump.. I don't want two fo the same pump
<Noxz> I understand ifI need to, but I just don't want to
<Noxz> money money
<sync> they are cheap tho
<sync> but yes, you need a separate pump for actual high vacuum work instead of chemistry work
<sync> vane pumps are quite low maintainance, most people just run them until they don't pump anymore
<Noxz> hrrmm
<Noxz> I think I also want the benefit of super low vac of the vane for chem
<Noxz> like, I need under 10 torr for some distillations.. and the pumps I am looking at are started at ~2torr... but really, not sure if that is easily achievable or a broken ebay find or what
<Noxz> getting sub 1 torr via a vane pump is simple
<Noxz> the one I am getting gets 1-2 mtorr
<Noxz> having more leeway, and making a controller for set pressure on the chemistry side of things, seems like a better route
<sync> I mean even a 50$ single stage vane will do that
<Noxz> but then you should add a oil mist filter so you dont get oil in your borosilicate glass
<Noxz> backsplash
<Noxz> it's also not very resistant
<sync> you would be suprised
<sync> they are not really worse than any other pump
<sync> they might not be able to cope with the massflow you want, but leybold d8 are very cheap
<Noxz> cheap is relative
<Noxz> the 3 phase + VFD is rather interesting
<Noxz> a simple 1/3 HP single phase GE motor on it currently
<Noxz> even sticking a 3 phase ac +VFD on a diaphragm would be interesting
<sync> on a diaphragm it is much less interesting imho because the suckage is much less constant
<sync> you could however speed it up during exhaust and slow it down during intake
<Noxz> that sounds a bit more complicated for the motor to do
<Noxz> especially if more than 1 stage
<Noxz> (I'm looking at 2 and 3 stage ones, and my current hacky setup is 2)
<sync> well, a diaphragm is usually just one wobl stage
<sync> you need an encoder to know the shaft position, yes
<sync> I only use 3 phase motors because I refuse to use dc motors in 2017 :D
<Noxz> what's wrong with DC?
<Noxz> single phase AC is what I woud pick out
<Noxz> DC is at least fairly variable/easy to operate
<Noxz> and has constant torque
<sync> so has 3 phase with FOC
<Noxz> alright, but what's so bad about DC?
<Noxz> lots of places really like DC because there isn't RF generated like with AC
<sync> dc has brushes unless it is a bell shaped armature motor
<Noxz> there's perm magnets on rotor, design, so brushless
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<sync> well, yes, bldc is still a 3 phase motor tho
<Noxz> is it? hrrmm
<sync> it has to be
<Noxz> so.. nothing against bldc? or... ?
<sync> yes, bldcs are glorious
<Noxz> ahh
<Noxz> just checking ;)
<sync> but usually overkill for simple jobs like that
<sync> async with FOC is fine
<Noxz> for reference, I really like these guys' motors: http://www.anaheimautomation.com
<Noxz> not super cheap, but not expensive neither, american made from what I have read/seen (I have steppoers from them)
<sync> ah, one of the usual reseller of chinese motors and drives
<Noxz> are they chinese?
<Noxz> they seem super sturdy though
<sync> oh haha wow, analog servo amp with hall feedback in 2017
<Noxz> maybe just as replacement?
<sync> no
<sync> yeah, the motors are most likely chinese, looking at the specs and their pricing
<Noxz> oh, I think some controllers are american made
<sync> possibly
<sync> but it is 70s tech
<Noxz> my motors are in the garage otherwise I would pull one out to lok at if it states
<Noxz> where it was made, on it
<sync> well, that doesn't mean much
<Noxz> china can make good stuff
<Noxz> and americans can make bad stuff
<Noxz> you are right
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