First post here. Found this forum while hunting for info on this particular grinder. This belonged to my late grandfather who passed away when I was little. It's an old craftsman bench grinder that I just got running again. He had left it with the wires cut off and covered in dust.
Craftsman 1/4 H.P Ball Bearing Split Phase Grinder. 115.19500
Shields, tool rests, grinding discs etc all there.
Bearings run smooth.
Switch was bad so I ordered and replaced it with a new one.
Now here is the problem.
Upon inspection of the motor windings, it appears one set of the windings has suffered some heat damage. This was caused upon my initial connection of the wiring which was incorrect. The motor made a buzzing sound and did not move. It was either this action it my grandpa who discovered the windings were shot and decided to cut the wires off. This remained connected for at most ten seconds at which point it started smoking a sweet smelling white smoke.
I took it apart and cleaned the centrifugal switch which I believe was stuck. Used 320 grit sandpaper and cleaned up the contact.
Spliced in new wires where needed and resoldered all connections followed with a double layer of heat shrink tubing.
After doing some research I determined the wiring to be incorrect and required the grinder as such. Hot to black wire, neutral to white wire and red wire, ground wire to grinder chassis.
It now runs fine according to my knowledge. I can hear the centrifugal switch kick after a second or so of running. The motor accelerates freely and remains at a steady rpm until I turn it off. No smoke and no excessive heat except for a slightly warm temperature around the motor area after running for a few minutes.
The motor windings look like they overheated and the smoke/smell was the enamel coating burning off of the windings. I have since resistance tested the windings and found the following. Black-white 6.5ohms. Red-white 9 ohms.
Does the damage on the motor look bad? Is it the start winding or the run winding??
Any way to test the condition of the motor? I have a simple multimeter. No specific motor testing equipment at my disposal.
Look forward to hearing back! Aloha
Craftsman 1/4 H.P Ball Bearing Split Phase Grinder. 115.19500
Shields, tool rests, grinding discs etc all there.
Bearings run smooth.
Switch was bad so I ordered and replaced it with a new one.
Now here is the problem.
Upon inspection of the motor windings, it appears one set of the windings has suffered some heat damage. This was caused upon my initial connection of the wiring which was incorrect. The motor made a buzzing sound and did not move. It was either this action it my grandpa who discovered the windings were shot and decided to cut the wires off. This remained connected for at most ten seconds at which point it started smoking a sweet smelling white smoke.
I took it apart and cleaned the centrifugal switch which I believe was stuck. Used 320 grit sandpaper and cleaned up the contact.
Spliced in new wires where needed and resoldered all connections followed with a double layer of heat shrink tubing.
After doing some research I determined the wiring to be incorrect and required the grinder as such. Hot to black wire, neutral to white wire and red wire, ground wire to grinder chassis.
It now runs fine according to my knowledge. I can hear the centrifugal switch kick after a second or so of running. The motor accelerates freely and remains at a steady rpm until I turn it off. No smoke and no excessive heat except for a slightly warm temperature around the motor area after running for a few minutes.
The motor windings look like they overheated and the smoke/smell was the enamel coating burning off of the windings. I have since resistance tested the windings and found the following. Black-white 6.5ohms. Red-white 9 ohms.
Does the damage on the motor look bad? Is it the start winding or the run winding??
Any way to test the condition of the motor? I have a simple multimeter. No specific motor testing equipment at my disposal.
Look forward to hearing back! Aloha
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