Craftsman radial arm saw - motor smoke

[Chip Lindley]

Things I've learned about electic motors:

1) Blow them out with compressed air regularly to keep them operating
2) Don't whack on the end of the armature with a hammer (though I used a wooden mallet - I'd be more gentle in the future)
3) Support the armature directly when removing or installing a roll pin in the spacer nut.

Jim, your experience with this motor is how we usually learn (trial-and-error) Of course, there is the internet, with quick searches that can turn up myriad info on any subject imaginable! Maintainance and trouble-shooting of common single-phase motors, among them.

A good thing this is only a common Sears RAS motor; not some rare, expensive repulsion/induction motor, incase you committed an unpardonable motor-tinkering faux pas!

[Jim A. Moore]

NOTE: the replies got too deep for the forum to show - so I'm catching up at the top level]

I decided the most interesting part of the problem was that the saw started up once I pushed the armature in.

When I took the motor apart, I had to remove a spacer on the blade end of the armature. The spacer was basically a large unthreaded nut - held in place by friction and a roll pin.

The roll pin was not centered in the spacer - it was midway between the center of the spacer and the end. I wondered if I put it back in the same orientation as when I removed it.

So - I backed out the pin, removed the spacer - and reinstalled the other way - pushing the armature back into the motor.

Bingo - motor is back running.

Things I've learned about electic motors:

1) Blow them out with compressed air regularly to keep them operating
2) Don't whack on the end of the armature with a hammer (though I used a wooden mallet - I'd be more gentle in the future)
3) Support the armature directly when removing or installing a roll pin in the spacer nut.

Jim, your experience with this motor is how we usually learn (trial-and-error) Of course, there is the internet, with quick searches that can turn up myriad info on any subject imaginable! Maintainance and trouble-shooting of common single-phase motors, among them.

A good thing this is only a common Sears RAS motor; not some rare, expensive repulsion/induction motor, in case you committed an unpardonable motor-tinkering faux pas!

Thanks Chip. The other lesson was to more carefully think through the problem and possible solutions before acting. For example, taking the roll pin out. The first time I did this - the motor was dismounted and sitting on a piece of plywood. But the armature wasn't supported - so I'm guess I was whacking on the bearings.

The last time I remove it - the motor was mounted in the carriage. I tried removing it w/o any other support. This not only beat on the motor bearings, but also the saw arm and carriage. I stopped and supported the armature with some wood after a couple of whacks.

As you said, good lessons to learn on a $20 motor vs more expensive/harder to replace motor.