Re: SRSG motor - HELP!!!!!

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "by way of Terry Fritz <twftesla-at-qwest-dot-net>" <FutureT-at-aol-dot-com>

In a message dated 6/9/02 1:41:12 PM Eastern Daylight Time, tesla-at-pupman-dot-com
writes:

Greg,

Sorry to hear of the motor failure.  Others have successfully
used these motors, but I noticed that these motors are often
cheaply made.  Mine was used only as a bench grinder, but
after a few years of use, it burned up.  Motors do run hotter
when they're modified for sync use.  Perhaps the insulation
on the wire was inferior in quality.  I don't know why it just
sat there and vibrated at times, but often the manufacturers
of bench grinders don't worry much about starting torque.
A cap start motor will have a much greater starting torque,
and is more likely to start every time.  I'd say overall the
bench grinder motor was probably an inferior quality and
design.

Cheers,
John


>
> Today I was running my coil and getting solid 8 foot arcs, when
> suddenly, and rather destructively, the SRSG motor died. The motor is a
> 1HP bench grinder, which I had modified to run in sync. I think it is a
> capacitor run motor. Upon inspection, some of the windings were melted,
> and the entire motor was full of carbon. I saw no reason for it to fail.
> No sparks hit it while operating. It all happened rather suddenly. I
> have had some funny problems with this motor. Often, when applying
> power, it would just sit there and vibrate back and forth, as if it
> didn't know which way to spin. Could this just be because I stuffed up
> when grinding the flats (off centre, unequal size, etc)? Could this and
> the failure be related (was the motor drawing excess current, causing
> the wires to melt etc)? Before I go and buy a new grinder, are these
> motors suitable for this pupose, or are they doomed to fail?. It was
> definitely running in sync ok. Has anyone else successfully used one of
> these motors for sync operation?
>
> Cheers,