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

PS: Sorry if people are getting duplicate messages from me. BT
Internet's news service has been truly dreadful recently. I think they
propagate messages by putting them to sea in bottles. They then wait
until they find a bottle before they display the message on their own
server.

Ignoramus6501 wrote:
Very nice pictures, although, obviously, they do not show motor rewind
and such. Congrats!

Thanks. I didn't actually do the rewind myself. There's a guy locally
who does rewinds at very reasonable prices (about half the price of a
new 1/4 hp motor). I didn't quite trust myself to rewind the motor, so I
sent it to him. I can't really take a picture of the inside of the
motor, but I can see it through the cooling vents and it looks good as
new. Sometime I'd like to try rewinding a less important motor, though.

I did all the work on the pump myself and have plenty of pictures of it.
Lots of careful disassembly, cleaning and reassembly with new seals. I'm
amazed that there are still several companies supplying full seal kits
for this pump; it was out of production by 1970.

Chris

Christopher Tidy wrote:
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.

Here's my page on overhaul of such pump:
http://www.iki.fi/ktu//es50/es50_overhaul.html

This is the single-stage (ES) version, the double
stage (ED) version has two rotary vane units.
Otherwise very similar - the failing output valve
is identical in both.

These old pumps really last for ever, with
tender loving care from user.

Kristian Ukkonen.

PS: Sorry if people are getting duplicate messages from me. BT
Internet's news service has been truly dreadful recently. I think they
propagate messages by putting them to sea in bottles. They then wait
until they find a bottle before they display the message on their own
server.


Nicely poetic rant!!

Nice little project to boot.

Kristian Ukkonen wrote:

Christopher Tidy wrote:

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.


Here's my page on overhaul of such pump:
http://www.iki.fi/ktu//es50/es50_overhaul.html

This is the single-stage (ES) version, the double
stage (ED) version has two rotary vane units.
Otherwise very similar - the failing output valve
is identical in both.

These old pumps really last for ever, with
tender loving care from user.

That's a nice page. I plan to do something similar, hopefully including
a bit of history about the firm of W. Edwards, but I haven't got round
to it yet. You're right that the ES 50 is very similar to the ED 35.
Apart from the fact that one's a single stage pump and the other is two
stage, the only difference I can see is that the ED 35 doesn't have the
nipple on the exhaust valve.

Seal kits for these pumps are still available from several firms. I got
mine from Kevin at GE Scientific (now Vacuumplus):
http://www.vacuumplusuk.com/
You could also try Island Scientific:
http://www.island-scientific.co.uk/

After talking to several people at Edwards I acquired a manual for this
series of pumps. It was published before the ES 50 was introduced, but
it still includes a lot of useful advice. I put it online for a friend
who is restoring another Edwards pump. You can download it he
http://www.ruggedmachines.com/docsto...nce_Manual.pdf

I don't know if the ES 50 uses the same shaft seal as the ED 35?
Somewhere I have a spare ED 35 shaft seal, because I ordered one before
I knew that a full seal and spring kit was available, then the kit
included another. If it fits your pump you might as well have it - it
isn't doing me any good right now :-D.

Best wishes,

Chris

RoyJ wrote:


PS: Sorry if people are getting duplicate messages from me. BT
Internet's news service has been truly dreadful recently. I think they
propagate messages by putting them to sea in bottles. They then wait
until they find a bottle before they display the message on their own
server.


Nicely poetic rant!!

Nice little project to boot.

Thanks, Roy! I am really going to have to get in touch with BT again and
put some pressure on them to fix their news server. The problem is that
it is run by another company who won't admit the it sucks, and BT seem
unwilling to sack them.

Chris