table saw motor binding electrical smoke resistance noise jerky....how BAD

Apr 04, 2009 31 Replies

My table saw motor has gone bad. It was like the blade was binding on something, and came to a fast stop when switched off. Then there was significant electrical smoke I had to air out. I unplugged it for a day. Now when I plug it in and start it it seems as if there is a series of jerky electrical resistance spurts, accompanied by a pulsating noise. Like the motor is firing against itself - resisting its own powered rotation by sending quick spurts of electricity power in the wrong direction. Rough, brief, jerky rotation.



It came with a complete manual listing all parts including a full motor, but also has a separate exploded parts illustration of just the motor. Unfortunately it's out of warranty. So can I suspect to replace any parts, without having to replace the whole motor?


table saw motor binding electrical smoke resistance noise jerky....how BAD



Mastercraft 55-6886-6 10" 15A 120V 60Hz 3.0 hp max 5000 rpm no-load speed



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Sounds like might be worn/bad brushes or commutator. How deep are you willing to go to save a buck? May be best to jes replace motor.

nb

Congratulations, you get to help jump start the economy by purchasing a replacement motor.

By the time you price out a replacement universal motor, you may find a new saw price to be just as attractive.

Lew

If it is belt drive, have you taken off the belt to verify the motor is the problem?

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*You may be able to save some bucks and have it rebuilt at an electric motor repair shop. Check the yellow pages. If nothing else they can tell you what is wrong with it. You might want to add thermal protection onto the motor control of your saw to prevent future damage to the motor.

The hard part is, putting the smoke back in.

Well, it could be a direct drive universal motor...

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Hi, Does the motor have capacitor? It may be shot.

Ah yes, some small saws with universal motors have brushes. Glad you were able to learn something from Usenet today.

I will admit ignorance of "table saw motor". Are you saying there are no brushes in universal single phase AC motors? I'm sure Milwaukee would love to know this.

nb

There is a brush assembly part number. What does this mean? (if anything different)

There is no belt. The blade is bolted to the shaft.

There seems to be no capacitor, but a circuit breaker / rocker switch. I cleaned this circuit breaker / rocker switch out once as it has stopped working, but I can't see this being the problem this time. Could it?

Hi, Mastercraft is maybe even lesser than Sears tools.

5,000 RPM should have given you the clue this is a universal motor and thus has brushes.

So much for your electrical knowledge.

Lew

Just shows to go you ---A little knowledge can be a dangerous thing. And, some times, it is the littlest minds that tend to dump on others = the most.

P D Q

Yes, many of the 'newer' cheap ones use brushes. Not surprising at all.

They may be full of sawdust?

Jimmie

On 4/4/2009 1:29 PM notbob spake thus:

Brushes for a *table saw motor*?

Just goes to prove the value of advice you get from Usenet ...

On 4/4/2009 3:02 PM Doug Winterburn spake thus:

You mean like on one of them cheap "motorized" saws? I thought the O.P. had a *real* table saw. So yeah, I guess it could have brushes, but not likely.

Yes.

Saw is a "Kung FU Machinerty" Special.

I bought one for $50 in the mid '80s to throw in back of car for use at the boat yard.

If you get 2 years, consider yourself lucky.

Lew

On 4/4/2009 3:27 PM Lew Hodgett spake thus:

Whoops; missed that part of the post. So it does have brushes.

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