I just about completed a total restoration on my 1941 vintage Logan Lathe, I ran my electric motor to clean up the motor shaft with a little sandpaper as it was pretty rusted up. The motor ran fine as I cleaned up the shaft, I shut it down to inspect the shaft and saw some more cleanup was necessary. I attempted to restart the motor and all I get now is a humming. The motor is wired up through a reversing switch to run the motor in both directions, it hums either way the switch is engaged. I checked the starter capicator and it tested fine. It's kinda acting like it's trying to run in both directions at the same time. I am going to pull the motor apart tomorrow to see if there is something obvious. Does anybody have any experience with these motors, I sure do hate to have to buy a new one. I priced them and they run about 280 dollars. I already have way too much into this darn lathe as it is and really hope this motor is fixable. Thanks
Electric Motor Follow-up Just as information to anyone thinking about throwing away an electric motor that appears to not be starting but does hum. My motor would just hum when attempting to turn it on. The motor is a capacitor start motor so first thing I figured was the capacitor was bad. I tested the capacitor with a volt ohm meter in the resistance testing mode. The capacitor tested bad so I bought a new one, installed it and the motor still just hummed, wouldn't start. I now suspected that I tested the cap. wrong since it was unlikely that the new capacitor was also bad. Sure enough the new capacitor tested bad, this confirmed a very likely bad testing method by myself. Come to find out I forgot to short out the capacitor before testing it. So I shorted it out and then put my test meter to read the highest capacitance which was 20000ohms. The capacitor now tested good as the resistance slowly went to open circuit as the capacitor charged up. I wasn't convinced my motor was fried so I took it apart. As soon as it was apart I was pretty sure I found the problem. There is a switch for the capacitor start motors that engages the capicator for start and then is switched off at a certain rpm by a centrifugal device that acts to turn the switch off. I suspected the switch was bad. Tested it and sure enough the contacts were dirty, cleaned up the contacts put the motor back together and it now starts and runs fine. Hope this can help someone else from purchasing a new motor.
Don, Sure glad to see you corrected the problem with your motor, as I was reading the problem you were having I figured what your problem was in the cap, as i have worked in an electric motor repair shop for + 18 years. Sometimes they can be tricky & the average person doesn't have a clue.
