Reversible motor runs fine one way, blow circuit breaker in reverse.

One of those heat-shrink solder sleeves would work well for that.
 
I'll leave it up to you on how to repair it, if lots of strands are cut you'll need to do some surgery, brain salad and otherwise
-M
 
Success! Held my head just the right angle and found two screws that held the centrifugal switch. The rotor came right out leaving me plenty of room to work with. Used RJ's suggestion of using a butt splice, crimping it and then slide a heat shrink over it. Real careful putting the cover back on the housing since I think the wire originally was pinched. And after a while from vibration. it shorted. Two things that I'm grateful. Good thing for a three wire with ground. Other wise a hot lathe. Can't tell you guys how much that I appreciate the suggestions you gave.
 
silence dogood said:
I have a Lathemaster 8x14 about 10 years old. The magnetic on/off switch started chattering, then only start but would not run. Traced the problem to a loose clamped on lug. Replace and still had some chattering when turned on. And just for grins tried to run it in reverse. Blew house breaker. I don't use the reverse much but it did work before. Traced problem to a couple of contacts in the forward/ reverse switch. Both contacts measured about 20 ohms when it should be zero. Not good, Before ordering anything traced the wiring and made a schematic. The guy that wired this thing must be totally color blind and get his kicks out of staring at bowls of cooked ramen. Example. the hot wire on the power cord is black, good. Then it is connected to a GREEN wire, then red, then white. The neutral on the power cord is white, good, then brown (huh). I won't even describe the mag switch and all the circuit loops. By the way the mag switch has no nomenclature of any sort. So started from scratch, Replaced both the mag switch and the forward/reverse switch with common standard mag switch and drum switch and made the wiring simple. Works great, except that it still blows breakers on reverse. The motor has a start and run caps. Can that be the problem and if so why? I know that motor caps are really two caps in one. Could one be shorted? They don't measure that way. Any help would be greatly appreciated. Mark
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I hate to bring this back from the dead, especially as my first post…but my Lathemaster lathe is having roughly the same issue, except mine starts and runs one direction but as soon as you flip the switch in reverse it pops near the switch and trips my breaker.
I read thru your testing process but unfortunately while I know my way around a meter, I don’t know what the motor “caps” are. I’m hoping it’s a raw wire somewhere similar to your issue, but if you or anyone else can explain in a little more detail the areas or caps ( location) to test I’d really appreciate it. I’m also going to need to check the switch too obviously- but at least I can replace that cheaply if that’s the problem. It appears to me to be more switch related since it will run beautifully one direction.
The lathe has been solid and really doesn’t have much usage on it and I’m surprised it even has this issue.

Thanks in advance!
 
Sounds like you have the same problem that I did. You may have to take apart the motor and check the wiring as you can see in the pictures earlier. I should have but did not write a follow up. My bad, did not think something like this would come up again. The short had burnt the contacts of both the drum switch and the mag on/off switch. When I start to turn on the motor, the switch would chatter and then the motor would run fine either direction. Whoever wired the lathe must have been colored blind and previously worked in a noodle factory. Could not find any info on the mag switch. So completely rewired it with a different drum switch and mag on/off switch. She now starts and purrs like a kitten. Give me a couple of days and I will show some pictures and a wiring schematic. Mark
 
silence dogood said:
Sounds like you have the same problem that I did. You may have to take apart the motor and check the wiring as you can see in the pictures earlier. I should have but did not write a follow up. My bad, did not think something like this would come up again. The short had burnt the contacts of both the drum switch and the mag on/off switch. When I start to turn on the motor, the switch would chatter and then the motor would run fine either direction. Whoever wired the lathe must have been colored blind and previously worked in a noodle factory. Could not find any info on the mag switch. So completely rewired it with a different drum switch and mag on/off switch. She now starts and purrs like a kitten. Give me a couple of days and I will show some pictures and a wiring schematic. Mark
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Thanks so much. I really appreciate it. I’m going to pull the switch today and do a visual check on it at least. See if anything looks burnt or shorted.
 
Switch visually looks good. Actually found the exact replacement on Amazon just in case it ends up testing bad.

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I edited this post since I had some doubts about the validity of the test.
The best way to isolate the problem would be to (with power plug pulled) disconnect the motor wires and tape them, then plug the unit in and switch
to reverse; no breaker trip should occur which would point to the motor being at fault
 
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markba633csi said:
A test you could perform would be to reverse the power plug after you have run it in forward but before you switch it to reverse. If it now runs in reverse but blows in forward then that points to the problem being at/in the motor like dogoods was
-M
ps with today's 3-prong plugs you would need an adapter with two narrow prongs to do the test
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Be cautious buying import switches of that type- I have seen several variations of internal contact arrangements. Most styles could be made to work but may not be a "drop in" replacement without some detective work and rearranging of wires
Check for a contact diagram when buying online
 
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