Air compressor motor swap

[MATREDGT84]

I have an early 2000's Craftsman 60gal air compressor and the electric motor has quit working. I tried replacing both capacitors but that didn't fix it.

With no belt on the motor the motor will spin up to speed but it takes a minute to get going. If you put the belt on the motor won't spin at all, eventually tripping the overload.

I drained all the air out of the tank and the motor still won't spin the compressor. The compressor does spin by hand. I even tried flipping the motor on and spinning the compressor by hand to see if it would spin up but that didn't work.

The motor on the compressor is a 56 frame which seems common. Except on this compressor they didn't use the 4 bolt mounting plate, but a pin that the motor pivots on. Seems to let the weight of the motor help tension the belt.

So my question is can the guts of a new 56 frame motor be swapped into the old motor case so I can use that pivot mount, or do I need to tell my wife I have to buy my welder now so I can fabricate a new mount for a 4 bolt mount?

Thank you,
Mike

 

[Walkers]

I’d say the later is your best choice. Nothin’ quite like that new welder smell!

 

[wyliesdiesels]

I have an early 2000's Craftsman 60gal air compressor and the electric motor has quit working. I tried replacing both capacitors but that didn't fix it.

With no belt on the motor the motor will spin up to speed but it takes a minute to get going. If you put the belt on the motor won't spin at all, eventually tripping the overload.

I drained all the air out of the tank and the motor still won't spin the compressor. The compressor does spin by hand. I even tried flipping the motor on and spinning the compressor by hand to see if it would spin up but that didn't work.

The motor on the compressor is a 56 frame which seems common. Except on this compressor they didn't use the 4 bolt mounting plate, but a pin that the motor pivots on. Seems to let the weight of the motor help tension the belt.

So my question is can the guts of a new 56 frame motor be swapped into the old motor case so I can use that pivot mount, or do I need to tell my wife I have to buy my welder now so I can fabricate a new mount for a 4 bolt mount?

Thank you,
Mike

Did you check the centrifugal switch? It’s possible that it’s not switching the start capacitor into the circuit causing the issue youre having

 

[Walkers]

You were asking about that switch earlier. It is under the end cap opposite the shaft end. Fairly simple arrangement to figure out if it is working or not. Arced contacts, or springs that have come off are the only things I have ever encountered with them.

 

[The Cobbler]

I know the motor you're talking about. I actually have one and if it ever fails, I will fab up a bracket to mount a 56f motor to, probably by cuting off the bracket from the original motor

 

[pancho400cid]

can the guts of a new 56 frame motor be swapped into the old motor case so I can use that pivot mount?

Short answer: No

do I need to tell my wife I have to buy my welder now so I can fabricate a new mount for a 4 bolt mount?

Short answer: Yes

 

[MATREDGT84]

Thanks for all the input. Just placed my order for the welder.

 

[vwpieces]

If you were contemplating taking motor apart to swap internals, take it apart to see what's inside. Check the centrifugal SW mechanism and the contact plate.
My 80gal has a Dayton motor and they or Grainger do not sell a contact plate for it I haad to look elsewhere. I was able to size one up and fix it myself. Certainly took a lot more time and research to find a compatible plate than it did to replace the plate, but 2years ago this motor was $1000 and it's probably $1500 today. Plate cost me about $35.