Search found 1050 matches

by Rich Feldman
Thu Feb 25, 2021 1:47 am
Forum: Announcements and Site Administration Topics
Topic: Fry's Closing Down
Replies: 2
Views: 174

Re: Fry's Closing Down

Yeah, just heard about it in today's newspaper. End of an era. Not as big a cultural sea change as the end of Radio Shack, though. Another small dent in American greatness. A much more unusual institution than the late Orchard Supply Hardware chain. I first encountered Fry's in about 1980, at their ...
by Rich Feldman
Mon Feb 22, 2021 5:40 am
Forum: Items For Sale
Topic: Random Transformer for sale
Replies: 1
Views: 228

Re: Random Transformer for sale

Looks like it could be a HV-isolated filament transformer.
What's the resistance between the two brass terminals on top? Does the red insulated part have any other terminals?
by Rich Feldman
Thu Feb 11, 2021 12:00 am
Forum: Fusor Construction & Operation (& FAQs)
Topic: Mass flow controller question
Replies: 20
Views: 1265

Re: Mass flow controller question

I've been happy with several purchases from Svcstore, generally picking them up in person since they are not far away. I think that's where I got my NIM bin and detector-bias power supply. Here's a post by Joe Gayo about MFC's, with a followup by me about what's inside one I was given by Greg Courvi...
by Rich Feldman
Mon Feb 08, 2021 6:38 pm
Forum: Items For Sale
Topic: Rich Feldman's store. Today's feature: beryllium sheet
Replies: 16
Views: 4071

Re: Rich Feldman's store. Today's feature: beryllium sheet

Just measured both kinds of vacuum hose, which are still available for cost of shipping. I think both are intended to go on 1/2" OD spigots, or similar hose-barb fittings. hosen.jpg The clear stuff is 0.50" inside, 0.77" outside. In my experience, ordinary worm-gear hose clamps can secure and seal t...
by Rich Feldman
Fri Feb 05, 2021 3:25 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Heat pipe cooling
Replies: 3
Views: 423

Re: Heat pipe cooling

Before today I didn't know that pinch-off seals could be made with nothing but tube metal. Found out lots from one maker of tools for the job, starting with pinchoff.gif http://www.pinchofftool.com/node/5 They mention importance of annealing, and mechanical cleaning of the surfaces to be welded. How...
by Rich Feldman
Thu Feb 04, 2021 8:48 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Heat pipe cooling
Replies: 3
Views: 423

Re: Heat pipe cooling

We use tons of heat pipes at work, about the size of pencils. An easy demonstration to do with a loose heat pipe: try stirring a mug of very hot coffee or tea or chocolate. The handle end gets too hot to touch within a couple of seconds. Hmm ... what would be a good working fluid for heat pipe at 50...
by Rich Feldman
Sun Jan 31, 2021 4:13 pm
Forum: Items For Sale
Topic: Rich Feldman's store. Today's feature: beryllium sheet
Replies: 16
Views: 4071

Re: Rich Feldman's store. Today's feature: beryllium sheet

Since Covid stay-at-home rules began, the Be sheet & my neutron-detecting stuff have gathered dust in an out-of-the-way place at work. I'll retrieve it next time I'm there, some time in February. The P3 and P4 pieces are still available, but new 2x2 inch pieces will require more cutting. At 2, 4, or...
by Rich Feldman
Sat Jan 02, 2021 3:07 am
Forum: Announcements and Site Administration Topics
Topic: Not a covid post! Get ready for the vacuum
Replies: 18
Views: 2135

Re: Not a covid post! Get ready for the vacuum

I expect the monthly dry-season swap meets out here will be mostly canceled in 2021, as were all dates in 2020. To make room for tinkering at my home, lots of stuff being saved for sell-cheap-or-give-away would need to go directly to e-waste. Overcoming the feeling of "duty to stuff" is the challeng...
by Rich Feldman
Sat Jan 02, 2021 1:46 am
Forum: Ion Gun Design and Construction (& FAQs)
Topic: Beam on Target Project (BOT 2021)
Replies: 48
Views: 7303

Re: Beam on Target Project (BOT 2021)

Nice work, Mark! As with motor-powered cutting tools and x-ray generators, the hazards of microwave power can be mitigated with knowledge, care, and instrumentation. Re: "Bell Jar" figures 2 and 4. By peculiar coincidence, the last two MWO's I broke down for recycling had sections of conventional re...
by Rich Feldman
Sat Jan 02, 2021 12:39 am
Forum: Images du Jour
Topic: Catalytic converter shield augmentation?
Replies: 3
Views: 318

Catalytic converter shield augmentation?

Please bear with my claim to be relevant, briefly, in this forum. On Thanksgiving day, my old Prius joined the ranks of catalytic converter theft victims. It's the most popular type for that crime, 'cause the CC can be pulled exceptionally fast (2 bolts & 1 saw cut) and is exceptionally valuable ($4...