Re: making a motor synch?

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

Original poster: "Christoph Bohr by way of Terry Fritz <teslalist-at-qwest-dot-net>" <cb-at-luebke-lands.de>

Hi David.

sorry I have to get back onto that, but I thinks you are probable closer to
success than you might think.
Before removing more Material from the rotor I'd strongly recommend trying a
bigger start-cap first in combination with a variac.
I used a benchgrinder too and the motor looks and acted exactly as you
describe it and I feel it might work.
However, better than taking off too much material an loosing torque. When
the motor syncs, you will instantly "feel" it. The number of revolutions
when in sync is probably a bit higher than what you get now.

sincerely

Christoph

 > Hi John,
 >
 > Yes, I did try running the varaic all the way up to 140 volts
 > but I still heard the wa-wa "hunting" sound. It seemed to
 > start this hunting sound with the variac at around 85 to 90
 > volts but it nver would stop once it began, no matter how
 > high i turned the variac voltage (up to the 140 volt limit).
 > I may try removing the rotory disc and replacing with the
 > cardboard disc to see if it can lock at all.
 >
 > < I'm not sure how much metal should be removed for a 3450 rpm
 > < motor to make it sync best.
 >
 > Yea, I'm not sure either since this is my first real try at
 > modifying an induction motor. One other thing that I may
 > need to mention is that this motor was the motor of a Black
 > & Decker bench grinder and appears to be of the split phase
 > type, since it has no external starting capacitor, only one
 > small running capacitor under the cradle. I think Bill Wysock
 > stated that this was not the proper type of motor to modify
 > for salient synchronous operation. I'd really rather get a hold
 > of a 1725 RPM motor for this purpose anyway :^)
 >
 > David Rieben
 >
 >
 >
 >