# Craftsman table saw motor hums but won't spin



## ChuckBarnett

I picked up a Craftsman 113.29943 10" table saw a few days ago and am cleaning it up and such. All of a sudden today the motor just hummed with out spinning the blade.


I removed the belt -no spin, just hum.
I had the capacitor checked and it is good.
A couple days ago I rotated the motor in its housing about 90 deg. so that the vents were down and the capacitor was up.
When I started it today, I heard a funny sound and shut it off. Started it again and the same sound. Because the blade was at full height, I thought perhaps that the belt guard was contacting the belt and adjusted it. Only hums ever since.
The armature rotates, not without some squeaking and not like it is spinning on the best bearings.

I've never messed with motors, saws... feeling ignorant here...

Any ideas?


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## ChuckBarnett

photo


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## DaveTTC

In my experience a humming motor has meant one of 2 things

1) binding on something, but it seems you have checked that which could include ceased or ceasing bearings. 

2) windings burnt out (means rewind the motor or replace, you don't have to replace the whole motor as pictured, just the bit with all the wires wound round it)

Dave The Turning Cowboy


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## woodnthings

*more likey than not it's the start capacitor*

But you said you had it checked. I'd try a replacement just to make certain.
If there is a pungent odor you may have "smoked" the motor, if not, probably not.
Some motors have a centrifugal starting winding and contacts. Make sure the contacts are contacting..... Be Careful ..... electricity can be a shocking experience, depending on your experience.


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## ChuckBarnett

I don't smell anything bad. I did try to help it by starting the shaft spinning with my hand as I turned the switch on, and it seemed that it tried to turn a little with that help.


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## KRM45

Lower the blade some and try again. My C-man saw will bind if I raise the blade too much.


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## DaveTTC

Don't know if changing your brushes is an option, not sure what noise a motor makes when they wear out.

Dave The Turning Cowboy


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## GeorgeC

Take it to a motor repair shop.

George


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## DaveTTC

+1 on George's advise. Must be early in the morn there George.

Dave The Turning Cowboy


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## woodnthings

*no brushes on that motor*



DaveTTC said:


> Don't know if changing your brushes is an option, not sure what noise a motor makes when they wear out.
> 
> Dave The Turning Cowboy


That's an induction motor Dave, not a Universal AC/DC type with brushes. Stationary power tools with separate motors have induction motors. The lower end aluminum top "table saws" have a direct drive Universal motor, like a circular saw....just so's you know..... :smile:


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## ChuckBarnett

I will pull it and take it to our local Ace Hardware. They are pretty knowledgeable and come pretty cheap. They will know of a motor repair shop in the area I would expect. 

Hoping for the best for the least,


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## Stevedore

I agree with woodnthings' suggestion to check the starting contacts. They're usually easily accessible, assuming you have to ability to partially disassemble the motor, and have been the source of problems on my shop motors a few times over the years. 

If you prefer not to do the disassembly, I doubt that a motor shop would charge much, if the only problem is the starting contacts.

About 30 years ago found a nice new-looking Dayton 1/3 HP motor by someone's trash on garbage day. I took it home, and all it needed was to have it's starting contacts cleaned. I used it to run a grinder for many years; now it powers my belt sander.


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## Steve Neul

I had a air compressor motor do that this week. I took it apart to see if there was any thing obviously wrong internally and it was just full of dirt. I thoroughly cleaned it out and put it back together and it worked fine.


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## Pirate

Figure out which way it spins, and wrap a cord around the pulley, to give it a good spin, then turn it on. If it runs, and you know the start cap is good, it has a bad start switch, and needs the contacts cleaned.
Be sure the cord is pulled all the way off the pulley, before turning on!


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## SeniorSitizen

KRM45 said:


> Lower the blade some and try again. My C-man saw will bind if I raise the blade too much.


The trunnion is leading but the motor isn't following. Sounds as if a cap screw was not installed correctly during set up. If not corrected it will eventually become expensive to repair. 

I'm not allowed to do private messages and I can't find the operator's manual or I would point you to the screw I'm mentioning.


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## woodnthings

*mine did the same*

Quote:
Originally Posted by *KRM45*  
_Lower the blade some and try again. My C-man saw will bind if I raise the blade too much._

The trunnion is leading but the motor isn't following. Sounds as  if a cap screw was not installed correctly during set up. If not corrected it will eventually become expensive to repair. 

If the blade was all the way up the arbor pulley would touch the bottom of the table, probably because I messed with the pulley sises...I donno? Probably unlikely in this case, but easy to do as for eliminating any issues.


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## ChuckBarnett

SandburRanch said:


> The trunnion is leading but the motor isn't following. Sounds as if a cap screw was not installed correctly during set up...


The motor won't turn even with the belt off. It did work, but now just hums. I've just pulled it and taken the ends off. Going to snoop the net for basic motor repair tips. :-\


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## Dave Paine

ChuckBarnett said:


> The motor won't turn even with the belt off. It did work, but now just hums. I've just pulled it and taken the ends off. Going to snoop the net for basic motor repair tips. :-\


Start with this site. Chaincarver Steve posted a good thread on repairing motors recently.

http://www.woodworkingtalk.com/f12/repair-your-bandsaw-other-motor-crash-course-46405/


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## bisley45

Sounds like the centrifugal switch is not functioning properly check the contacts they are most likely dirty.


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## Froneck

Bisley45 is right, A centrifugal switch is used to connect the Capacitor to the start winding. You could have dirty contacts or the weights are stuck and don't move the switch. If the motor does start and the contacts don't disconnect the capacitor there will be a funny noise while the motor is running. Eventually you will burn out the start winding or the Capacitor. Also the Capacitor might be bad and not be able to start the motor. If you put a volt meter on the 2 terminals connected (only to the 2 terminals on the Cap. not to ground or any where else) and you read 120VAC or 240VAC voltage (Depending on what input power your connected for), your switch is good and the Capacitor is probably bad.

Frank


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## blaineo

<<--10 years working in an Electric Motor Repair Shop.....

All the info you're reading is good, and most of it correct!  

It's one of three things......

1) Start Capacitor is bad...cheapest and easiest thing to check...remove it, should only have two wires going too it, and it doesn't matter what wire goes on which post when you reconnect. Take it in, and have someone check the MFD on it.....99% of the time, you'll be able to see in a heartbeat if it's blown just by looking at it, and a baaad smell....

2) Start Switch/Centrifugal Switch (Governer)...the start contacts are not making contact....could be a "dead spot" in the motor...just rotate the shaft a 1/4 turn and see if it starts...or a 1/2 turn..... the switch itself might just be shot...OR the governer is sticking on the shaft or the weights aren't flying out....

3) The motor start windings are shot. You may have an open in them..or they burned out...be careful..too much starting and too much "Humming" can fry them when you're testing things, and they weren't burnt to begin with... So..

Did the problem just start on you after you'd used it a couple times after you got it? Or did ya clean it up, plug it in for the first time and the motor hummed?


Don't know why the world just can't run on 3 Phase...lol less of a hassle with motor repair....you have windings, rotor, and bearings....simple fixing..


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## ChuckBarnett

I took the motor apart. I used a business card lightly soaked in isopropyl alcohol and slipped it back and forth between the brass spring arm and the eight inch diameter arm. I'm guessing those are the contacts? I generally blew the motor out and hit what I'm taking to be centrifugal switch with DuPont teflon dry lube.

Put it back together, plugged in, and with a little and spin it started up. And the several times without the spin by hand since.

You guys are great!


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## Pirate

ChuckBarnett said:


> I took the motor apart. I used a business card lightly soaked in isopropyl alcohol and slipped it back and forth between the brass spring arm and the eight inch diameter arm. I'm guessing those are the contacts? I generally blew the motor out and hit what I'm taking to be centrifugal switch with DuPont teflon dry lube.
> 
> Put it back together, plugged in, and with a little and spin it started up. And the several times without the spin by hand since.
> 
> You guys are great!


But, what are you going to do to fix it?
If you decide to take it to a motor shop, be sure you get a price to check it out. I called a shop about a Jet 3 hp motor. They wanted $60 to check it out!


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## ChuckBarnett

blaineo said:


> <<--...Did the problem just start on you after you'd used it a couple times after you got it? Or did ya clean it up, plug it in for the first time and the motor hummed?


Great stuff here! I had used it a couple of times after I got it and then a day or so ago it would only hum.

Thanks again!


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## DaveTTC

woodnthings said:


> That's an induction motor Dave, not a Universal AC/DC type with brushes. Stationary power tools with separate motors have induction motors. The lower end aluminum top "table saws" have a direct drive Universal motor, like a circular saw....just so's you know..... :smile:


Thx for that, always good to learn 

Dave The Turning Cowboy


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## knotscott

bisley45 said:


> Sounds like the centrifugal switch is not functioning properly check the contacts they are most likely dirty.


If it's not the cap, centrifugal switch is the next logical item to check. Any chance that motor has two caps? Sometimes there's a cap buried in the junction box.


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## DaveTTC

Does your saw have an overload button, sometimes you just need to press a button and all is well.

Dave The Turning Cowboy


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## woodnthings

*read post 22*



ChuckBarnett said:


> I took the motor apart. I used a business card lightly soaked in isopropyl alcohol and slipped it back and forth between the brass spring arm and the eight inch diameter arm. I'm guessing those are the contacts? I generally blew the motor out and hit what I'm taking to be centrifugal switch with DuPont teflon dry lube.
> 
> Put it back together, plugged in, and with a little and spin it started up. And the several times without the spin by hand since.
> 
> You guys are great!





DaveTTC said:


> Does your saw have an overload button, sometimes you just need to press a button and all is well.
> 
> Dave The Turning Cowboy


Methinks he's got it fixed... I donno?


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## DaveTTC

I missed that one, thx. I'll have to pay closer attention 

Dave The Turning Cowboy


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## Froneck

You might want to use some more dry lube. Then turn the motor on and off but let is stop first or after you hear the slight click from the centrifugal switch. Give the lazy switch a little workout!

Frank


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