Search found 41 matches

by Ed Meserve
Sat Jul 18, 2020 2:14 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Restarting Efforts on Demo Fusor II
Replies: 14
Views: 992

Re: Restarting Efforts on Demo Fusor II

Thanks guys.

The OD is 3/4'. Rich, if you have a length of rubber vacuum hose of that size, I'd be interested in buying some off you. If so, DM me.

Thanks!

Ed
by Ed Meserve
Sat Jul 18, 2020 12:32 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Restarting Efforts on Demo Fusor II
Replies: 14
Views: 992

Re: Restarting Efforts on Demo Fusor II

Hi all, I have a question regarding connection for my diffusion pump exhaust. It appears when it was removed from its previous system connection, it was cut off, without a standard connection flange. How would you suggest I make the connection? diffusion pump.jpg diffusion pump exhaust port.jpg
by Ed Meserve
Sun Jul 12, 2020 7:29 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Restarting Efforts on Demo Fusor II
Replies: 14
Views: 992

Re: Restarting Efforts on Demo Fusor II

Thanks for that, Richard.

Based on the pictorial reference, I'd say it's somewhere close to Jon Rosenstiel's "Very Slight Improvement" slide at around 600 mTorr, maybe slightly more diffuse (tough to see with the old webcam).

demo2_run-2020-06-12-2205-grid.jpg
2020-06-12 Run: Grid Only Image
demo2_run-2020-06-12-2205-grid.jpg (4.18 KiB) Viewed 213 times
by Ed Meserve
Sun Jul 12, 2020 5:51 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Restarting Efforts on Demo Fusor II
Replies: 14
Views: 992

Re: Restarting Efforts on Demo Fusor II

As always, thanks for the insight, Dennis. I changed the oil in the pump with some Welch Duo-Seal Oil just before this last test. I'll flush it again and retest. I think you're onto something with the gauge calibration; I just powered up the gauge at ATM, and the analog output read 8.65V, which per ...
by Ed Meserve
Sun Jul 12, 2020 4:46 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Restarting Efforts on Demo Fusor II
Replies: 14
Views: 992

Re: Restarting Efforts on Demo Fusor II

For the original pump-only test I recorded three entries: 7:24pm -> Atm 7:25pm -> 63 mTorr 7:38pm -> 16 mTorr I don't remember why, but I didn't note anything between the 2nd and the third reading. I've since swapped out the KF16 flange on the pump to a KF25 for the flexible line, so I couldn't put ...
by Ed Meserve
Sat Jul 11, 2020 11:14 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Restarting Efforts on Demo Fusor II
Replies: 14
Views: 992

Re: Restarting Efforts on Demo Fusor II

With everything plumbed up as previously pictured, the best I was able to pump down to was 251 mTorr (pretty terrible). I tried to use a Doug Coulter trick and introduce helium around the various suspected leak points but, no luck as it appears that it was still pulling in more air than I could intr...
by Ed Meserve
Sat Jul 11, 2020 10:13 pm
Forum: Items For Sale
Topic: Seiko Seiki STP-H300C Turbo Molecular Pump for Sale
Replies: 0
Views: 182

Seiko Seiki STP-H300C Turbo Molecular Pump for Sale

I have a Seiko Seiki STP-H300C for sale for $600 plus shipping. I have not tested it (hence the cheap price), but it spins freely. I acquired it with a pile of other equipment, without a controller. I don't think I will ever need this kind of horsepower (around 300 L/s) and used controllers I've see...
by Ed Meserve
Sun Jun 28, 2020 10:14 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Home Built Metering Panel
Replies: 10
Views: 6251

Re: Home Built Metering Panel

Rich,
I have a Fluke 6kV probe that I can use to check it.

I think I'll change over to the acrylic sheet with standoffs now, instead of running with wood. I'll leave it with the 200MOhm for now, but leave space to upgrade the chain.

Richard / Rich / John, thanks for the input!

Ed
by Ed Meserve
Sun Jun 28, 2020 9:38 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Home Built Metering Panel
Replies: 10
Views: 6251

Re: Home Built Metering Panel

John, How would you rate a PEX standoff (yeah I know, plumbing, but it's what I have lying around) with Two part epoxy with a zip tie for additional strength? The plexi would be vertical and the PEX would be horizontal standoffs. This is a junk piece of plexi for testing. The one I would use won't h...
by Ed Meserve
Sun Jun 28, 2020 5:49 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Home Built Metering Panel
Replies: 10
Views: 6251

Re: Home Built Metering Panel

The resistors I used came from Digikey. They are rated for 4kV , 1W. rnx.pdf I soldered the two 100 Ohm resistors leads together, then slipped them into an small segment of aquarium airline tube, with just air in the tube. Then I sealed them in with Liquid Tape. Once cured, I slipped that into a 7/1...