Search found 237 matches

by richnormand
Sat Jul 20, 2019 7:01 pm
Forum: Announcements and Site Administration Topics
Topic: unusual posting results
Replies: 11
Views: 2138

Re: unusual posting results

On login: "could not find..."

Same thing just happened to me.
Sat 20, 2:58 EDT

Clicked on the forum bar in the main site and all is OK.
by richnormand
Fri Mar 29, 2019 7:35 pm
Forum: Neutrons, Radiation, and Detection (& FAQs)
Topic: Making a SHV connector
Replies: 14
Views: 7471

Re: Making a SHV connector

Should the label on the third photo with the long isolation be SHV not MHV?
by richnormand
Tue Mar 05, 2019 3:31 am
Forum: Announcements and Site Administration Topics
Topic: Dumping the trash
Replies: 9
Views: 4800

Re: Dumping the trash

I remember a forum from Russia a few years ago that required me to take a few tests (about 10 questions) on semiconductor electronics before giving me access. Not a bad idea. Similarly another car related site flashed a rules page to you until you got a minimum posting. That gave the moderator a way...
by richnormand
Fri May 11, 2018 6:27 pm
Forum: Vacuum Technology (& FAQs)
Topic: Vacuum pump rebuild
Replies: 55
Views: 20104

Re: Vacuum pump rebuild

Congrats! If you click with Python there is a very good online course from MIT via the Edx program (assuming you have time). I would not leave the thermocouple sensor as shown in your previous photo for a 24 h run. Pirani probably OK. I am sure Richard would know. From your valve geometry was it bec...
by richnormand
Thu May 10, 2018 11:18 pm
Forum: FAQs: Neutron - Radiation Detection
Topic: FAQ - Extensive paper on neutron activation
Replies: 13
Views: 9116

Re: FAQ - Extensive paper on neutron activation

Very nice Richard. 1) I too end up doing revisions a few times on manuscripts, papers and posting to forums. It was easier in the past (review, typing pool, review again, etc...before sending to publisher) but now, with instant posting, I do appreciate the few days this forum allows me to clarify, c...
by richnormand
Tue May 08, 2018 9:52 pm
Forum: Vacuum Technology (& FAQs)
Topic: Vacuum pump rebuild
Replies: 55
Views: 20104

Re: Vacuum pump rebuild

Just a guess or two: 1) Leak between the exhaust and the intake? Can you devise a way to see if atm pressure overtakes an oil seal or a gasket seal or a bearing seal? The fact that it is intermittent with plugging the exhaust and (I assume) once the pump is warmed up could be due to metal expansion ...
by richnormand
Mon May 07, 2018 7:07 pm
Forum: Vacuum Technology (& FAQs)
Topic: Vacuum pump rebuild
Replies: 55
Views: 20104

Re: Vacuum pump rebuild

""Rich, I do not understand your comment. The picture of your stator looks like mine. Does your rotor not have vanes in it? How can you not worry about removing material from the stator? Below is a drawing of one stage of my pump."" Thanks for the drawing. A picture is worth a thousand words indeed....
by richnormand
Sun May 06, 2018 6:04 pm
Forum: Vacuum Technology (& FAQs)
Topic: Vacuum pump rebuild
Replies: 55
Views: 20104

Re: Vacuum pump rebuild

Quote Richard: ""It is also noted that if even only moderately successful, the "hands-on" knowledge gained and the extent of the effort involved in this attempt might well be priceless in that it will lead to successful future efforts"" Have to agree with Richard about this. After my rebuild success...
by richnormand
Sun May 06, 2018 3:25 am
Forum: Vacuum Technology (& FAQs)
Topic: Vacuum pump rebuild
Replies: 55
Views: 20104

Re: Vacuum pump rebuild

In my previous posting in this thread about rebuilding my Trivac D16 I mentioned the damage caused by a split-pin holding the rotor to the main shaft that disintegrated in the pump. It was mostly to the stator walls, rotor sides, vanes and they were pretty deep since the pin was made of hardened ste...
by richnormand
Wed Apr 18, 2018 9:26 pm
Forum: Vacuum Technology (& FAQs)
Topic: Vacuum pump rebuild
Replies: 55
Views: 20104

Re: Vacuum pump rebuild

I do agree with Richard's and Jerry's views here. But, if you are in for a hero experiment, in particular after rebuilding the motor, here is what I ended up doing to mine. When I got my Trivac D16AC pump it was jammed. Not quite as bad as yours in appearance inside but it had been used to pump sili...