Cydrome Leader wrote:
Christopher Tidy wrote:

Chuck Sherwood wrote:

My 11 year daughter is showing a strong interest in science.
We received a Edmunds catalog with lots of cool stuff in it.

I have always wanted to play with vacuum stuff when I was a kid
and I didn't get much of a chance so I figure now is my chance.

By the way I'd recommend a belt driven pump. These are generally much
better made than the direct drive pumps, and should you need a new motor
there are a wide variety of replacements available.

Best wishes,

Chris



All the broken pumps I've seen were neglected and ruined on the pump side, not the motor. Not using a pump (letting it sit with old oil) seems to be the worst thing you can do to it.

Interesting. I got a two stage pump with a burnt out motor free from the
Cavendish Laboratory. Probably the motor had burnt out because of a
faulty oil distributor valve in the pump, which allowed the pump
chambers to fill with oil and stalled the motor. I got the motor rewound
and replaced the pump seals and it's a good pump. I've been lead to
believe that this isn't uncommon on pumps which don't have a thermal
cut-out fitted to the motor. Badly damaged pumps are most likely the
result of water being drawn into the pump (and being allowed to sit,
causing corrosion), or abrasive dirt causing wear.

Chris