"Christopher Tidy" wrote in message
...
Don Foreman wrote:
On Sun, 18 Sep 2005 03:53:57 +0000 (UTC), Christopher Tidy
wrote:


Hi all,

Just thought I'd post a couple of pictures of the vacuum pump I was
talking about last month. It's a little Edwards ED 35 two stage pump
which I found in a local laboratory's skip (dumpster) last year and have
spent a bit of time restoring. I had the motor rewound, repainted it,
stripped and cleaned the pump and fitted new springs and seals, and
mounted it on some anti-vibration feet. Now it works very sweetly and
holds its vacuum for more that a week after I switch it off. I'm planning
to use it for some experiments on electrical discharges in low pressure
gases. I'm meaning to create a web page with some pictures of the
restoration, but so far I haven't got round to it, so I thought I'd share
a couple of pictures.

Pump as found:
http://www.mythic-beasts.com/~cdt22/vp_as_found.jpg

Pump restored:
http://www.mythic-beasts.com/~cdt22/vp_restored.jpg

Enjoy,

Chris


Chris, what vacuum can this pump pull?

I think the official manufacturer's figure is of the order of 0.0001 torr
if everything is working perfectly. But I haven't measured the ultimate
vacuum as I don't have a working vacuum gauge. I do have some ancient
Penning gauges and a controller I might try fixing sometime, though.

Chris


Try www.belljar.net for some neat vacuum experiments and information, Chris.

Garrett Fulton