3006guns
05-26-2014, 06:51 PM
Yep, it's the motor. Just hums and won't spin. After doing an exhaustive search for answers on the internet, the only bit of advice that everyone agreed on was to buy a new tumbler, as the original motors were evidently made by a little known Baslovian company somewhere in the Carpathian Mountains.
I removed the bowl and set it aside. This exposes four hex nuts which you remove and the motor is now loose from the tumbler. I carefully guided the cord and motor from the base and set it on my work bench. I spun the shaft and found no binding at all, but I DID notice a decided wobble in the shaft. Okay, the bearings must be shot which causes the armature to be pulled to one side by magnetic force and "seize" the motor. To disassemble:
Turn the motor over and remove the four screws which are threaded through the motor frame (note: clean the exposed threads first and add a few drops of light oil...eases removal considerably). Two of these screws require a regular screwdriver. The other two require one of those "star" type drivers. The little plastic fan is just a press fit...twist it off. There's a set screw holding the off center weight.....remove it. The motor end plates can now be removed. Be careful....there was a spring tension washer under the rear bearing on mine. Make a careful note of how everything goes back together.
I expected to see a couple of bronze sleeve bearings, but to my astonishment I found two very nice quality ball bearings....and they had zero play in them. Puzzled, I temporarily reassembled the end plates and found that the outer bearing races had actually "wallowed out" the aluminum motor end plates from vibration. The bearings appeared to be fine. Okay, found the problem......but how to repair it?
Well, since a replacement motor from Grainger is $65 I turned to the machinist's friend........JB Weld! I cleaned the bearing recesses with alcohol, mixed up some JB and slathered it into the recesses with a wooden match. I reassembled the motor, tightening the screws while spinning the shaft occasionally to make sure I hadn't glued the armature (I had to dig out a little excess with the match stick). With the screws fully tightened the shaft spun easily, so after waiting about an hour I plugged the motor in and switched it on. It started immediately and ran smoothly. I shut it off and will now let it cure overnight, but I think I saved myself from buying a new tumbler for awhile! :)
Edit note: Another motor problem with these 1292 tumblers was a wire breaking from the constant vibration. This failure was responsible for several fires and resulted in a recall by Midway. It was one of the heavy copper wires attached to the frame and repairing it was dicey at best. It CAN be done, but if that turns out to be your problem, either order another motor from Graingers (stock# 4M080) and thread the holes in it.......or just buy another tumbler!
UPDATE, 5/27: I let the JB Weld cure until noon today, then began reassembling the tumbler. Before I slide the off center weight back on the motor shaft, I stuck it in my cut off saw and lopped off a healthy 1/4". After everything was back in place I poured in about a half bowl of corn cob and some 6.5 Jap brass, then hit the switch. It started immediately and the difference was amazing.......smooth and quiet, with a uniform tumbling action like energetic ripples on a pond. All the cases moved smoothly from the outside and down through the inside of the bowl. So, it looks like the culprit was an oversize weight. By trimming it I removed the horrible rattling abuse to the motor that finally destroyed it. With any luck it will last many more years. :)
I removed the bowl and set it aside. This exposes four hex nuts which you remove and the motor is now loose from the tumbler. I carefully guided the cord and motor from the base and set it on my work bench. I spun the shaft and found no binding at all, but I DID notice a decided wobble in the shaft. Okay, the bearings must be shot which causes the armature to be pulled to one side by magnetic force and "seize" the motor. To disassemble:
Turn the motor over and remove the four screws which are threaded through the motor frame (note: clean the exposed threads first and add a few drops of light oil...eases removal considerably). Two of these screws require a regular screwdriver. The other two require one of those "star" type drivers. The little plastic fan is just a press fit...twist it off. There's a set screw holding the off center weight.....remove it. The motor end plates can now be removed. Be careful....there was a spring tension washer under the rear bearing on mine. Make a careful note of how everything goes back together.
I expected to see a couple of bronze sleeve bearings, but to my astonishment I found two very nice quality ball bearings....and they had zero play in them. Puzzled, I temporarily reassembled the end plates and found that the outer bearing races had actually "wallowed out" the aluminum motor end plates from vibration. The bearings appeared to be fine. Okay, found the problem......but how to repair it?
Well, since a replacement motor from Grainger is $65 I turned to the machinist's friend........JB Weld! I cleaned the bearing recesses with alcohol, mixed up some JB and slathered it into the recesses with a wooden match. I reassembled the motor, tightening the screws while spinning the shaft occasionally to make sure I hadn't glued the armature (I had to dig out a little excess with the match stick). With the screws fully tightened the shaft spun easily, so after waiting about an hour I plugged the motor in and switched it on. It started immediately and ran smoothly. I shut it off and will now let it cure overnight, but I think I saved myself from buying a new tumbler for awhile! :)
Edit note: Another motor problem with these 1292 tumblers was a wire breaking from the constant vibration. This failure was responsible for several fires and resulted in a recall by Midway. It was one of the heavy copper wires attached to the frame and repairing it was dicey at best. It CAN be done, but if that turns out to be your problem, either order another motor from Graingers (stock# 4M080) and thread the holes in it.......or just buy another tumbler!
UPDATE, 5/27: I let the JB Weld cure until noon today, then began reassembling the tumbler. Before I slide the off center weight back on the motor shaft, I stuck it in my cut off saw and lopped off a healthy 1/4". After everything was back in place I poured in about a half bowl of corn cob and some 6.5 Jap brass, then hit the switch. It started immediately and the difference was amazing.......smooth and quiet, with a uniform tumbling action like energetic ripples on a pond. All the cases moved smoothly from the outside and down through the inside of the bowl. So, it looks like the culprit was an oversize weight. By trimming it I removed the horrible rattling abuse to the motor that finally destroyed it. With any luck it will last many more years. :)