Search found 92 matches

by Bruce Meagher
Thu Apr 19, 2018 2:51 pm
Forum: Vacuum Technology (& FAQs)
Topic: Vacuum pump rebuild
Replies: 27
Views: 1170

Re: Vacuum pump rebuild

Thanks for the pictures Rex, and the data point with the small pit on your first motor. I don't know what I was thinking last night. Clearly you can only remove a very small amount of material from the cylinder or rotor while still maintaining the oil seal at the top between the rotor and stator. We...
by Bruce Meagher
Thu Apr 19, 2018 3:27 am
Forum: Vacuum Technology (& FAQs)
Topic: Vacuum pump rebuild
Replies: 27
Views: 1170

Re: Vacuum pump rebuild

I agree that normally you wouldn’t give this pump a second look. There are tons of vacuum pumps available on the second hand market in great shape that require little to no work. Add oil and go. Is this pump destined for the scrap yard? Potentially, but honestly it does not matter. I fully expect a ...
by Bruce Meagher
Mon Apr 16, 2018 1:11 am
Forum: Vacuum Technology (& FAQs)
Topic: Can I make my own ConFlat flanges?
Replies: 27
Views: 567

Re: Can I make my own ConFlat flanges?

Clearly these type of flanges are made on CNC machines, so no reason you couldn't make one on a “precision” 5-axis CNC. However, as Dan mentions, it’s very unlikely you can make one cheaper (unless you have access to cheap 8”x8"x7/8” SS plate, custom CNC tooling, free time on the CNC, and don’t make...
by Bruce Meagher
Fri Apr 13, 2018 2:01 am
Forum: Vacuum Technology (& FAQs)
Topic: Vacuum pump rebuild
Replies: 27
Views: 1170

Re: Vacuum pump rebuild

Oops, my mistake! John, thanks for pointing out the error. I was trying to keep the exercise really simple, but that doesn’t work when you're doing it wrong! Rich, thanks for the spreadsheet and explanation. We'll spend some time talking about it, and re-run the experiment correctly when we have the...
by Bruce Meagher
Wed Apr 11, 2018 5:18 pm
Forum: Vacuum Technology (& FAQs)
Topic: Vacuum pump rebuild
Replies: 27
Views: 1170

Re: Vacuum pump rebuild

Patience you must have, my old Padawan. The motor is complete. In fact, Tyler just finished making some measurements with the Prony brake we assembled. Next, he has to cracked open the pump side and try to get it back into a usable state. Given the current pace he's still a few weeks/months away fro...
by Bruce Meagher
Mon Mar 12, 2018 6:42 am
Forum: Please Introduce Yourself
Topic: Hello from California
Replies: 3
Views: 296

Re: Hello from California

I’m excited Tyler is enthusiastic about running some physics experiments. Building a demo fusor will be a great opportunity not only to learn a little physics, but also enable him get his feet wet on the mill and potentially the lathe. Unfortunately in SoCal the kids don’t get many opportunities for...
by Bruce Meagher
Sat Jan 27, 2018 5:47 am
Forum: Vacuum Technology (& FAQs)
Topic: New LabView control setup for vacuum system
Replies: 10
Views: 571

Re: New LabView control setup for vacuum system

Really nice looking setups. I’ve read roots blower are helpful in speeding the pump down times in that critical region at the low end of the roughing pump and high end of the turbo. I’m curious if the pump down time is the primary reason for the additional pump, or are the gas loads in your applicat...
by Bruce Meagher
Fri Jan 26, 2018 9:21 pm
Forum: Announcements and Site Administration Topics
Topic: PMs stalled
Replies: 4
Views: 350

Re: PMs stalled

I've found private messages seem to stay in the outbox until they are read by the recipient. I still have one in my outbox that hasn't been read for months (the user isn't active anymore). Email seems to be a better way to communicate. If you click the users name there is an option to send an email....
by Bruce Meagher
Wed Jan 17, 2018 10:46 pm
Forum: New User Chat Area
Topic: Serial communication
Replies: 16
Views: 981

Re: Serial communication

Like Finn mentioned above, with an oscilloscope and the known working PC connection you could quickly debug this issue. It can be challenging in high school to get access to even the most basic test equipment. If you haven’t done so already, I’d highly recommend finding a mentor with access to this ...
by Bruce Meagher
Tue Jan 16, 2018 1:48 am
Forum: Images du Jour
Topic: Arc polarity for fusing wire?
Replies: 11
Views: 1069

Re: Arc polarity for fusing wire?

I tried this on my tig welder. A little alligator clip to attached the wire to the tungsten tip, and then a little zap. Tried both electrode positive and negative and both came out soft but I had argon flowing into the cup. I'd imagine your timer method should produce nice consistent sized balls. IM...