billmayo wroteI was blessed to have Tony Mann visit with me this past Monday and Tuesday. Tony stopped by to help determine why I was having problem with getting any Shopsmith motors to operate for the past 2 years. I have 2 AO Smith 3/4HP motors, a Mark VII GE 1 1/8 HP motor and 2 Emerson motors that I could not get to operate. The first 3 motors use a start relay in place of a centrifugal switch. After rechecking a run and start winding ohm readings with no shorts again, all within normal readings. We found no reason why these motors should not operate, but they only hum, not even a tune I know. We swapped current relays and capacitors without success. Since I have 5 more AO Smith ¾ HP motors that had not been tested, we started with them. All 5 motors operated with no problems. So we used one of the motors to test 12 start relays which all 12 worked along with about 6 capacitors. I have 5 more of the Mark VII 1 1/8 HP motors that were not tested. Each of these motors operated with no problems.
We did confirm that the Mark VII motors were operating at reduced power. All 6 motors used a start winding and a run winding in parallel with the other run winding being used as the start circuit. Since the start winding has 3 to 4 times more resistance, I would believe it would use 3 to 4 times less amps. So if each run winding uses 6 amp, the start winding would use only 2 amp. So I see the motor getting 6 + 2 Amps of power to run the motor vs 6 + 6 Amps if both run windings are being in parallel to run the motor.
So I had a series of five motors in a row that all readings are good but would not operate over a 2 year period. The 2 Emerson motors doing the same thing but we did not get to them. Therefore I had believed I was doing something wrong with these motors so I gave up wanting to convert these AO Smith ¾ HP motors or any other motors for reverse operation when I could not get them to operate in the normal mode.
I will be happy to mail one of the non-operating AO Smith 3/4 HP motors to anyone who wants to try to find what is wrong and tell me. You can keep the motor as it is worthless to me right now.
We did find time to build a belt sander from a few boxes of parts I had laying around. I have plenty of extra belt sander parts if anyone has a need, It was a very enjoyable time that we spent together again. The visit option is still open to anyone wanting to stop by and play in my shop.
I wish there were a way to "like" a post. People spending time working together to figure out how to resurrect old machines, whether they be chainsaws, motorcycles, or Shopsmiths, is one thread holding what's left of our culture together. Finding and fixing a short in the field windings is a couple notches above my pay grade.
