Search found 130 matches

by derekm
Mon Jun 29, 2015 12:46 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: 60 kV feedthrough design?
Replies: 9
Views: 5542

Re: 60 kV feedthrough design?

So the voltage is the square root of the depth of pocket :)
by derekm
Mon Oct 13, 2014 5:07 pm
Forum: High Voltage - Fusor Input Power (& FAQs)
Topic: Homemade Feedthrough
Replies: 20
Views: 11032

Re: Homemade Feedthrough

What is the diameter of the conductor inside the feedthrough?
This is important as the electric field is related to the diameter or the conductor.
by derekm
Fri Sep 26, 2014 5:27 pm
Forum: Vacuum Technology (& FAQs)
Topic: diffusion pump - big!
Replies: 1
Views: 1101

diffusion pump - big!

I didnt know they came in this size!
http://www.ebay.co.uk/itm/Large-Diffusi ... 53ff719c23
by derekm
Tue Aug 26, 2014 11:35 am
Forum: Vacuum Technology (& FAQs)
Topic: Edwards E2M12 trash or rebuild
Replies: 9
Views: 3211

Re: Edwards E2M12 trash or rebuild

My luck at buying pumps is bad. Wanted a decent backing pump and found a E2M12 locally. Seller said, "Like new vacuum pump in good working order." When I picked it up I noticed some brown residue in the exhaust port. Seller seems like a decent guy. I asked him how it had been used and he said for v...
by derekm
Tue Mar 04, 2014 12:03 pm
Forum: Vacuum Technology (& FAQs)
Topic: Roughing Pump Cooling
Replies: 14
Views: 4086

Re: Roughing Pump Cooling

I have a roughing pump to get my chamber down to about 5 microns, and after about five minutes of operation, the pump casing gets almost too hot to touch. Does anyone have any recommendations for cooling it off? I've already tried using a fan, but that didn't work well. Don't want to fry a $150 pum...
by derekm
Thu Feb 20, 2014 1:16 pm
Forum: Vacuum Technology (& FAQs)
Topic: Chamber Splattered With Vacuum Pump Oil
Replies: 6
Views: 2223

Re: Chamber Splattered With Vacuum Pump Oil

I remember stern expressions on the faces the lab tech at Uni and the lecturer going over again and again what not to do with a diff pump experimental set up. Obviously born out of clearing up after ham fisted undergrads.
by derekm
Wed May 08, 2013 7:31 pm
Forum: Vacuum Technology (& FAQs)
Topic: Repairing an Edwards E2M8 pump ?
Replies: 3
Views: 1563

Re: Repairing an Edwards E2M8 pump ?

Have you done the flushing thing as shown in the FAQs on vacuum pumps to get rid of the the crud.

There may be nothing wrong with it at all
by derekm
Wed Apr 11, 2012 9:20 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Tig welding problems (air leak)
Replies: 3
Views: 1821

Re: Tig welding problems (air leak)

<t>i have one of these cheap tig welders ... and my wifes brother in law(professional fabricator) remarked how well it worked... he put in a day using it.<br/> The concernwith them is reliabilty you have to be careful about dust and damp with them at least with my model. its stop working twice but w...
by derekm
Mon Apr 25, 2011 7:27 pm
Forum: Vacuum Technology (& FAQs)
Topic: Rebalancing turbopump rotors / vibration analysis
Replies: 6
Views: 3568

Re: Rebalancing turbopump rotors / vibration analysis

<t>Sounds like an update of the balancing gear my father used to balance industrial fans. In that set up the accelerometer fired a strobe light . By placing marks on the rotor the mark nearest the direction of accelerometer indicated the direction of imbalance. When I was a young boy he explained th...
by derekm
Tue Mar 01, 2011 8:37 pm
Forum: Fusor Construction & Operation (& FAQs)
Topic: Finished chamber
Replies: 7
Views: 3306

Re: Finished chamber

here's an idea for a restrictor - use the iris from a camera lens ... An Old lens can can be had for pennies. Build the iris into a flange with a simple o ring sealed rod to actuate it.
Lens irises have a fantastic turn down ratio. f1.5 to f16 in fact .