Sorry to hear that. It always sucks when you get a bad deal. But I
certainly wouldn't chuck the pump without dismantling it. When I got my
Edwards pump it was seized, though turning the pulley by hand freed it.
On dismantling I found only a minimal trace of dirt and corrosion - not
enough to affect the performance of the pump once it had been cleaned
out, but enough to seize it because of the very tight clearances. These
pumps are never easy to turn over, even when it perfect condition, but
naturally the motor should be able to turn it! I would dismantle it and
see what you find. A clean might solve the problem and be all that is
required for a de-soldering system, but you're likely to need to
replace the seals, gaskets and oil if you want good performance. Also,
you'll get to see the mechanism, which is really cool. It was so cool I
took some photos of the mechanism and turned it into a GIF animation,
which I meant to put on a web page about my vacuum pump project. I
never got round to it, but one day I will...

Good luck!

Chris

If the pump was totally emptied of oil when you got it, it might be
fine. Try turning it by hand to get the oil into the tight spaces. As I
said, there's a hell of a lot of friction in these pumps even when
they're running normally. I wouldn't be surprised if it was impossible
for the motor to turn a pump which had been drained of oil.

Chris

are you trying to pump something that has pressure in it? that will
stop a vacuum pump.
Vacuum pump oil has no wax in it, and is resistant to moisture
absorbtion, regular refer
oil is not the same i would flush the pump(well can't use r-11 anymore)
then refill with
vacuum pump oil turn over by hand. my big pump 8cfm would not pump at
all, then flushed
it and put fresh oil, still works like a champ 25yrs later. Won an
arguement with the eng.
staff at singer corp(hvac div ST.L.) small pump is 30 yrs old still
pumps down like new!
tt

Couple of additional points come to mind...of the "ingrained below the
usual need to mention them" sort.

Got a filter on the exhaust? Got the exhaust routed outside? Fine oil
mist is a considerable health hazard, and over the time that I was
working with pumps, keeping it out of people became an increasingly
elaborate exercise, with both filtration and ducting to carry it away.
There's not much, but it does not take much to cause damage, either. You
do not want this stuff in your house, your kids, etc...

If you are running the pump to warm and dry it, best to pump on a closed
vessel, or plug the intake, rather than pumping air through it - vacuum
pumps like to work at a vacuum.

When you stop the pump, best to vent the pump up to atmosphere. If you
want to keep a (low-quality) vacuum on something connected to it without
running it all the time (which is the usual method), provide valves so
that you can shut off the pump from the vessel, and vent the pump intake
without venting the vessel.

"Vessel" is whatever - bell jar, vacuum laminating bag, etc...

--
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