Motor Keyway Messed Up

[Mike Mulville]

Okay let me have it, how bad is this and is it repairable or do I need a new motor!? :(


Thanks

Mike

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[Dick Strauss]

Take a small file and remove a little metal along the shaft keyway until the key fits again. There is no worry as long as the key still fits snuggly when you are done.

[Tom M King]

Doesn't look fatal to me either. I'm sure I've fixed worse with a small file. If you need to, get some keyway stock in the next size up, and upsize the slots in the shaft, and pulley. If the pulley doesn't still fit tightly on the shaft, that may need to be replaced too.

[Jared Sankovich]

Take a small file and remove a little metal along the shaft keyway until the key fits again. There is no worry as long as the key still fits snuggly when you are done.

From the pic its worn oversized (wallowed out) a lot. That chunk on the end looks like the original sidewall.

Im guessing the key just falls out.

I would personally weld it up and re-machine the keyway.

[Mike Mulville]

From the pic its worn oversized (wallowed out) a lot. That chunk on the end looks like the original sidewall.

Im guessing the key just falls out.

I would personally weld it up and re-machine the keyway.

Yes brand new key just falls out and Pulley has wobble when tightened down and spun. I'll have to call around to find someone to repair this. Should I call machine shops or electric motor repair shops?

[Darcy Warner]

Get a pulley that uses a bushing.

[Dick Strauss]

I see the second bevel in the bottom of the keyway now from the key rocking.

I would go to a machine shop.

[Mike Mulville]

Yes, it's rocking in the opposite direction the motor turns which is what I would expect. How does this happen? Is it because the set screws came loose at some time?

[Myk Rian]

Yes, it's rocking in the opposite direction the motor turns which is what I would expect. How does this happen? Is it because the set screws came loose at some time?

That's the usual cause.

[Mike Mulville]

Alright then. I found a motor repair shop that does machining too. I'll give them a call tomorrow. I'll use loctite on the set screws for sure. Thanks. I'll let you all know what happens.

[Richard Coers]

Cover the key with petroleum jelly (as a mold release) and place it in the slot, shim it over to the good side with appropriate size wire placed perpendicular to the shaft, mix up some Devcon Plastic Steel Putty, and pack it in the crack. I mean really pack it. Then clean everything back up when fully hardened and you are back in business.

[Bruce Wrenn]

Cover the key with petroleum jelly (as a mold release) and place it in the slot, shim it over to the good side with appropriate size wire placed perpendicular to the shaft, mix up some Devcon Plastic Steel Putty, and pack it in the crack. I mean really pack it. Then clean everything back up when fully hardened and you are back in business.Best answer so far. Machining out key way will require removing rotor from motor and mounting in Bridgeport. If you should weld it up, heat could warp shaft, plus cause loss of temper. After it's welded, you have to turn it to size, them key way milled at another location. You can buy keys that are two sizes, so by machining out existing key way, you can keep it at it's current location. None of these options are very cheap!

[Mike Mulville]

Best answer so far. Machining out key way will require removing rotor from motor and mounting in Bridgeport. If you should weld it up, heat could warp shaft, plus cause loss of temper. After it's welded, you have to turn it to size, them key way milled at another location. You can buy keys that are two sizes, so by machining out existing key way, you can keep it at it's current location. None of these options are very cheap!

I'm a little worried that the wobble in the pulley means the shaft has worn unevenly but I guess that could be the pulley hole worn out too.

[michael langman]

Have the motor shop machine a key slot 180* from the damaged one on the shaft, if they cannot use the original keyway.

[Jared Sankovich]

Get a pulley that uses a bushing.

That would be the cheap, fast and permanent option.

[Mike Mulville]

That would be the cheap, fast and permanent option.

I haven't been able to find a unisaw three belt pulley with bushing.

[Wayne Lomman]

If your pulley wobbles, the bore is worn in the pulley. A worn key way causes backlash, not wobble. Get a new pulley and fit the key using Richard's method. The new pulley is a must otherwise all your effort won't fix the problem. Cheers

[Mike Mulville]

If your pulley wobbles, the bore is worn in the pulley. A worn key way causes backlash, not wobble. Get a new pulley and fit the key using Richard's method. The new pulley is a must otherwise all your effort won't fix the problem. Cheers


That's what I was thinking. Thanks Wayne.

[James A. Brown]

I have been a machinist and toolmaker and for a couple years worked in an electric motor shop doing mechanical repair. There are options, they could recut the keyway to a larger size and make a custom key to fit. Without seeing your pulley I can't say for sure but it could be repaired if you have enough room to make a sleeve large enough to have a new keyway cut in the sleeve. Not going to be cheap but do-able. Do take your motor and pulley both with you and see what they can do. Jim.

[Mike Mulville]

I have been a machinist and toolmaker and for a couple years worked in an electric motor shop doing mechanical repair. There are options, they could recut the keyway to a larger size and make a custom key to fit. Without seeing your pulley I can't say for sure but it could be repaired if you have enough room to make a sleeve large enough to have a new keyway cut in the sleeve. Not going to be cheap but do-able. Do take your motor and pulley both with you and see what they can do. Jim.

Thanks Jim. I have a very highly rated electric motor repair shop nearby and I'll see what they say. New motor is $450! H hopefully cheaper than that.

[Mike Mulville]

Finally got in there again and did some measuring. The motor pulley bore .750 on one end and .764 on the other. The motor shaft is .750 end to end, so that's good. The motor repair shop says it'll be about $150 bucks to machine a new keyway 180 degrees from the old one and they'd replace the bearings while they were at it. I could try the metal putty fix also. Looks like I'll be buying a new pulley either way at about $80. Anybody have a source for the pulleys any cheaper?

[Mike Kees]

Mike you said this is off a Unisaw ? Is it a triple belt pulley ? I have a bunch of Unisaw parts at my shop,goes hand in hand with buying and selling a couple Uni's... If you have the part number post it and I can check what I have.

[Zachary Hoyt]

I would look at Surplus Center, they have a lot of that stuff. If you need a triple I don't know if they have them, but for singles and doubles they're pretty cheap.
Zach
https://www.surpluscenter.com/Pulleys/Finished-Bore-Pulleys/?page_no=1&fq=ATR_Bore_Fractional:3/4\%22

[Mike Mulville]

Mike you said this is off a Unisaw ? Is it a triple belt pulley ? I have a bunch of Unisaw parts at my shop,goes hand in hand with buying and selling a couple Uni's... If you have the part number post it and I can check what I have.

I believe it's the 41-644 HD 3 groove pulley.

[Dave Cav]

Anybody have a source for the pulleys any cheaper?

Go over to OWWM and put a WTB post on BOYD.

[Richard Coers]

See if Grizzly has a knock-off saw that uses a 3 groove. Most of their "engineering" involved making identical copies.

[Jared Sankovich]

See if Grizzly has a knock-off saw that uses a 3 groove. Most of their "engineering" involved making identical copies.

Its the g1023 saw, and likely will fit

[Mike Kees]

Mike I checked at my shop. I have two different diameters. Pretty sure that they should be the same diameter (both pulleys on saw from factory). Do you know the outside diameter of pulley you need ?

[Malcolm McLeod]

Late to the party, and sounds like you have a path forward, so this may be just for posterity..?

I also think others may have alluded to this, but if you can file or machine a 'wallowed' keyway up to the next size, and the mating piece (pulley in this case) is still good you can machine keystock with a 'step' - allowing it to fit both - for a whole lot less than replacing all the bits and pieces.

[Mike Mulville]

Mike I checked at my shop. I have two different diameters. Pretty sure that they should be the same diameter (both pulleys on saw from factory). Do you know the outside diameter of pulley you need ?

The bore is .75" and the outer diameter is 3.5" 3 groove.

[Martin Wasner]

From the pic its worn oversized (wallowed out) a lot. That chunk on the end looks like the original sidewall.

Im guessing the key just falls out.

I would personally weld it up and re-machine the keyway.

Skip the welding and just cut another keyway 180º from the original

[Mike Mulville]

Skip the welding and just cut another keyway 180º from the original
Yup that's what the motor repair place said.

[Mike Mulville]

Its the g1023 saw, and likely will fit

Sorry guys I missed this suggestion. That pulley is 7/8" bore and I need 3/4".

[Tom M King]

I didn't look through these for you, and I forgot what diameter you were looking for. I did a google search for 3/4" bore three groove pulley
https://www.zoro.com/search?categoryl2=Pulleys%20%26%20Sheaves&q=&categoryl3=Standard%20V-Belt%20Pulleys&variants.attributes.Number_of_Grooves=3&categoryl1=Bearings,%20V-belts%20%26%20Power%20Transmission%20Equipment

[Mike Mulville]

I didn't look through these for you, and I forgot what diameter you were looking for. I did a google search for 3/4" bore three groove pulley
https://www.zoro.com/search?categoryl2=Pulleys%20%26%20Sheaves&q=&categoryl3=Standard%20V-Belt%20Pulleys&variants.attributes.Number_of_Grooves=3&categoryl1=Bearings,%20V-belts%20%26%20Power%20Transmission%20Equipment

I just bought one on ebay for $35. Delta and other places wanted $70+.

[Tom Trees]

I had a damaged keyway on my tablesaw motor, the same issue as yours...
I ended up welding and filing the damaged part, this took ages, as I'm not much of a welder.
It was very difficult and the filing was slow, nitty gritty hard work on the fingers.
I wouldn't want to do it again.
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Having a guess, I'd say it most likely happened in the first place because the pulley was not drilled on center.
I had to make a jig as I don't have a metal lathe... to mark file and scrape out the bore on center.
I then made a bush/sleeve to fit into the pulley from a hunk of steel
and turned it on the shaft of the motor.
I then cut a keyway into my "new" pulley and made a key.
In the end my key only fit 3/4 into the pulley/shaft and got stuck.
I tried the "persuader" which led to me breaking some of my pulley...quite a lot of cursing happened.
In the end I got the key out with quite a lot of careless angry bashes.
The fit was so tooight that I didn't need a key
So all that extra work of welding and filing the sides of the keyway, and making a key was a waste of time.

Moral of the story...
Check that pulley bore is on center
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Still running perfect, admittedly I don't use the saw all that much.
Good luck
Tom

[Chris Fournier]

From the pic its worn oversized (wallowed out) a lot. That chunk on the end looks like the original sidewall.

Im guessing the key just falls out.

I would personally weld it up and re-machine the keyway.

There it is! Perhaps you can measure things up and find a key that fits...

[Tom Bender]

Install a new key and lightly weld it to the shaft. First grind to make a little room for the weld.