1933 South Bend 9 - Older Ge Motor Questions

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buffcleb

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Howdy... first post here... I picked up a 1933 South Bend 9 quick change and I'm going through it right now.... cleaning years of grime and grease... I finished cleaning the saddle, apron, quick change gearbox and open gears on the end... I replaced the half nuts with a set off a 1926 one... they didn't have the detent in them so if filed it in...

now after starting and stopping it many times while testing I have noticed that sometimes when I start the motor it just hums... I quickly turn it off and rotate the motor slightly and it starts right up...

It really happens most of the time... sometimes it starts up fine...

Any ideas what could be causing this? is it a case of cleaning something? or is the motor in need of repair... there are several similar GE motors locally on Craigslist for $20-$40 so I have options...

thanks in advance...
 
I assume it is a single phase, capacitor start motor. The symptoms you posted are usually caused by either the capacitor gone bad or the centrifugal start switch not engaging the capacitor for start. Since it is an old motor, it could be either. You can take the motor apart, it is not difficult, and try to loosen up and de-gunk the centrifugal switch. A motor shop can test the capacitor, or the whole motor. That is usually fairly easily repaired.

A photo of the motor data plate would be useful to help you further.
 
thanks I'll grab a photo tomorrow when the light in the garage is better
 
I removed the motor and switch... while at it I pulled the power cord as the shielding was falling apart... quick question... as the old plug was not polarized I assume it doesn't mater if the hot wire goes to the more or the switch...

back to my original issue... I watched a couple of videos about centrifugal switches... in those the motor was pretty different... going to hunt for one with these older ge motors...

the capacitor was wet... so I am assuming its probably bad... I did not remove the waxed cardboard from the capacitor as it was firmly affixed... should I remove it? any ideas as to the size of the capacitor to order a replacement?

thanks
 
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Be careful with very old capacitors of that vintage as it probably contains PCB oil.
 
so how do I find out what to get for a replacement? does that cardboard just cover a metal shell with a label telling me what I need to know... or is the cardboard the capacitor shell?
 
It is single phase, and I assume capacitor start, not capacitor run. That capacitor sure looks suspect, but it can be tested. Be careful if you try that at home, it can be dangerous. It can also still be the centrifugal start switch, or even a wiring issue, or multiple issues. 1/4 horsepower is not a lot for that lathe, but they did have bigger horses in those days... 8^)
 
That's a start capacitor. No oil in it, PCB or otherwise. Might still be good but I'd replace it because it's so beat up. It's probably between 40 and 70 microfarads. Anything in that range will probably work. Check the centrifugal switch as well, though.
 
So I took the cardboard off and found the label... so now I'll order a replacement...

I took the motor apart and cleaned everything up... for the most part it was pretty clean...So I'll assume its the cap...


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