Tired motors ? chuck 'em or fix 'em

Mark Williams

Mark Williams

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Nov 28, 2000
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I have a 2" x 132" grinder with a motor on it that Noah used to power the pumping system on the arc. It has begun to start blowing the breaker after it's been running for a while. Would resurfacing the comutator and new brushes help or should I just get a new motor. You can see the beast here.

bigrinder.jpg
 
Gouge, I used to haul to Wisconsin and then pick up and deliver large electrical motors that had to be rebuilt. It was cheaper to rebuild them, according to my then boss. We never had to return one because of any problems afterwards, either. I had a 1/2HP rebuilt locally here, and it was better than new because they used copper.The price was higher than what I would have paid for that particular motor new, but the original was for a crucial use and failed because it had aluminum connected to copper connections; automatic corrosion because the the cheap bastid original motor.
 
I would kinda like to keep this motor. Its fun to hear it starting up. It sounds like it's a two speed. I mainly just use it for hogging.
variable would be nice though.

Mark
 
Rebuild it! BTW I love your shop. It's almost as messy as mine. Real knifemakers don't have clean, neat shops!!:D :eek: :footinmou :D
 
Get a quote. I worked as an electrician for the state water autority.
We had a lot of big motors rewound but the small ones sometimes it was cheaper to throw them away..

Depending on the type of motor there are a number of other things that may help. If it is an induction motor with a capacitor sometimes the capacitor needs replacing or the internal switch.

If it is the kind of motor with carbon brushes sometimes a skim under cut and re brush can be all it needs. If the windings are on the way out that Not a lot you can do to save them. Sometimes if it is moister getting in you can clean out the dust and rubbish bake the motor at a moderate tem then re varnish the winding with high temp varnish. Hard to do at home without an insulation tester. Andother test equipment.

I agree with Peter clean shops are for people too lazy to look for things.
 
Mark, I agree with Reg. My vote is to pitch it and buy a new motor. I've been an industrial mechanic for many many years, and unless your motor is very specialzed or proprietary in some way, or over 5hp I'd say your best course of action is a new one.

I've found out within the last year or so that I can buy brand new motors, quality motors, far cheaper than having our motor-rebuilders do their thing. Another up-side to all this is that the new motor will run far more efficiently and save you more money too.

Now as far as a messy shop: I HAVE to clean mine because I'm so bloody forgetful I'll misplace something if I don't have everything organized. I've tried both ways over the years, and organization and cleanliness helps me keep my head... and my knives in order.

:-)
 
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