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Just a guess ---- Burnt out start capacitor? Under the 'can' that's bolted to the outside of the motor. If that's it, it oughtta be about a $10.00 repair. Good luck!
 
First, I have my doubts it's a start cap. When they go bad, at the least all I have seen, they just sit there and humm.

You posted this in old iron, how old is the motor? Any chance it is a R/I (repulsion - induction) motor? It would have no start cap, thats the first hint. I have seen that happen with them before.

Some more info on the motor might help.
 
Chuck,

Do you know if this machine ever worked properly for the previous owner? If not, any possibility you've got a 3-phase motor on your hands? Do you see any of the "tubes" where a capacitor would be located? Could be if it is a 3-phase the converter is missing or shot. The tripping the breaker sure sounds like an internal short. Sounds like it's not a dead short, since it doesn't pop the breaker immediately, but pulling too much current for sure. Just thoughts.
 
Motor

Chuck I assume you are trying to run the motor on 110 volts. If you could please post a picture of the connection box. It would help to know if it is a capacitor start motor. I sounds like it is fairly new motor by the wire numbers.
 
Under no load, a motor can start moving if the start capacitor is dead..... Also some have both Start and RUN capacitors that keep the current flow even under power loads and such, perhap that capacitor is fritzed. Give it the ole Sniff test. or look for black goo (although I have seen dead guys that leave a fine looking body that don't stink.) Also the Centrifical switch may be rusty (Or caked in dust and resin) and not turning on the Capacitor. A little spray lube might help there. do it "Click" when you turn off and on the motor. No "Click", it ain't workin.

I have compressor that did the same thing yesterday, the start Capacitor has departed this earth and with it, all air power, right in the middle of a job... an hour delay whilst I borrow my son's pancake compressor. SWMBO says I need to downsize and send the old beast (28 years old, built from Truck Air Brakes system parts and compressor) to scrap heap and get a new pancake as I NEVER use air tools anymore.
 
You can test for a bad starting capacitor by giving the motor a good spin - in either direction - and then plugging it in (or switching it on) while the motor is still spinning at a decent speed. If the motor is otherwise good (and is wired correctly), the motor will pick up speed in the direction you spun it. If you want to be absolutely sure, disconnect the starting cap before you run this test. The reason is that the cap may have some small capacity left and if the starting circuit opposes the direction you spun the rotor, it can stop the shaft.

If the motor doesn't get up to normal speed with no load, you have another problem.

Mike
 
Hey Chuck, looks like a monster lathe, but the pics are real small, so it'd about impossible to see any of the wiring details. Can you resize them into the 800 x 600 range? Let me know if you need me to help.
 
Dumb question...

If just the front of the motor is getting real hot and not the back, couldn't it be just a bad bearing? Wouldn't that allow the shaft to turn for a few rpms, and then when the motor gets overloaded trying to power the shaft through a bad bearing, it trips the breaker?

I know nothing about electrical motors, but as a machinist I know bearings. When I first heard the description of the problem, I immediately thought...bearing problem. He did say this thing is beat up pretty bad. Maybe that's not it though. :dunno:
 
Chuck,

Calling that lathe a beast is like calling King Kong a chimp! This thing is huge. :rofl::rofl::rofl:

I can see that my 3-phase scenario is out the window. :dunno: Looks like it must have two capacitors from the verbiage on the motor. As I recall, you were seeing 15v on a couple of the leads, which makes a little more sense now that we're seeing the electronics associated with the lathe. Have you moved the pulley by hand to see if it feels like too much resistance? Might be able to confirm/rule out the possibility of the bearing issue. If you haven't already, I'd pull the cover off the capacitors to see if there are any signs of failure. Also, do you know if the previous owner ever disconnected the wires going to the motor or had anyone try to work on it.. Perhaps the wires didn't make it back to their original locations. I've worked on old tube amps for people who had done something along those lines that prevented it from working.

Just some thoughts,
 
When all else fails, Google "microkinetics lathe 1236" and you will find [this official MicroKinetics page] about the lathe. Hmmm ... I'm guessing that nobody handed over all of the "System Includes" items? (The technical manuals would have been nice!) ... Let alone any of the "Optional Accessories" listed there?

Here is one useful piece of "free" info, at least:
Motor & Electrics ... 2 HP, 220V, single phase

Oh, and checkout out the Hands On Training link. "Only" $1295 per attendee! :thumb: :)eek:)

PS - See the entry by cdarnell on [this machinist's forum page] Maybe you could register on the forum and ask for a scanned wiring diagram or something? :dunno:
 
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I looked around there site and could find wiring info or any type of parts manual.

Yeah, me either. So I thought maybe you could ask someone :huh: (like cdarnell on that other forum) to scan the wiring diagram from their manual and send it to you.


I thought about taking the training coarse. But it would end up costing around 2k with hotel travail and the coarse. :dunno:

I hear ya. Pretty steep. But it wouldn't do much good anyway without a running MicroKinetics lathe. :(

Still curious about those "extras" ... did any of them come with the lathe, or would you have to start from scratch and buy them all yourself?
 
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