Search found 446 matches

by ian_krase
Fri Jan 27, 2017 4:53 am
Forum: New User Chat Area
Topic: Bolts for vacuum chambers
Replies: 12
Views: 1338

Re: Bolts for vacuum chambers

I'm curious why plain high-grade carbon steel bolts are not used for atmosphere-side bolting. Minute contamination? Rust transfer to stainless?
by ian_krase
Sun Jan 22, 2017 4:30 am
Forum: New User Chat Area
Topic: What is this device?
Replies: 6
Views: 840

Re: What is this device?

IIRC aviation (military aviation? Aviation in general?) has lots of really unusual AC power delivery specifications.
by ian_krase
Wed Jan 18, 2017 9:39 am
Forum: New User Chat Area
Topic: What HV pumps can I rough with the mech pump I have?
Replies: 22
Views: 2353

Re: What HV pumps can I rough with the mech pump I have?

Yeah. I'm not sure what to do though, last time I tried turning off the pump on an evacuated chamber with no isolation valve did not go well. Do I just need to get a real vacuum valve?
by ian_krase
Tue Jan 17, 2017 6:35 am
Forum: New User Chat Area
Topic: What HV pumps can I rough with the mech pump I have?
Replies: 22
Views: 2353

Re: What HV pumps can I rough with the mech pump I have?

Well, today I tried it...

Got to 300 microns, which isn't great but which is much better.

How hot is it normal for a pump to get?

Just moving the valve causes a jump from 300 um to 600 um, and then the pressure rises about 150 um in 30 seconds which doesn't sound too good.
by ian_krase
Sat Jan 14, 2017 9:36 am
Forum: New User Chat Area
Topic: KJL purchasing?
Replies: 7
Views: 838

Re: KJL purchasing?

Duniway Stockroom is fairly nice though their selection is slightly limited. Ideal Vacuum Products also exists, and has a very wide selection (including brass KF parts for soft soldering!) though their marketing language is sometimes ambiguous as to whether some materials are actually suitable for p...
by ian_krase
Sat Jan 14, 2017 7:39 am
Forum: New User Chat Area
Topic: What HV pumps can I rough with the mech pump I have?
Replies: 22
Views: 2353

Re: What HV pumps can I rough with the mech pump I have?

IMG_20170113_230619.jpg Thank you all for your kind help. The cylinder is pyrex, a full 1/4 inch thick. The ends are... not as smooth as I would like them to be, but still pretty smooth. (need to figure out how to grind them down properly, sandpaper just wears out and is probably not the best thing...
by ian_krase
Sat Jan 14, 2017 5:49 am
Forum: New User Chat Area
Topic: What HV pumps can I rough with the mech pump I have?
Replies: 22
Views: 2353

Re: What HV pumps can I rough with the mech pump I have?

That's also a distinct possibility. Inconveniently, this pump doesn't have a gas ballast (it is cheap and compact). Can I get a similar effect by running the pump with a very slow air leak into the chamber? I've actually started a bit of Ebay windowshopping for better pumps. Unfortunately, most seri...
by ian_krase
Fri Jan 13, 2017 8:18 am
Forum: New User Chat Area
Topic: What HV pumps can I rough with the mech pump I have?
Replies: 22
Views: 2353

Re: What HV pumps can I rough with the mech pump I have?

I'm sorry about the huge image -- I wasn't aware it was just being inserted naively. I'll resize next time. Today I replaced teflon tape with anaerobic sealant... and seemingly have managed to degrade my vacuum to a dreadful 6 torr. Assuming my convectron is to be trusted which I am scared that it i...
by ian_krase
Tue Jan 10, 2017 6:21 am
Forum: New User Chat Area
Topic: Spark Plugs
Replies: 10
Views: 1628

Re: Spark Plugs

Update: The oil burner ignition plug that I have is not actually vacuum tight. Never mind, I guess.
by ian_krase
Tue Jan 10, 2017 6:11 am
Forum: New User Chat Area
Topic: What HV pumps can I rough with the mech pump I have?
Replies: 22
Views: 2353

Re: What HV pumps can I rough with the mech pump I have?

Huh. That's useful since I might be able to scrounge a turbo pump. I investigated the problem and it turns out that my system is not vacuum tight and I wasted money on a ceramic feedthrough (sparkplug style, but not actually a sparkplug). Using an older, less safe chamber I was able to get down to a...