Jet Mini Motor Overheating Problem

It's good to clear the chips away every once in a while. If you add a couple of blocks under the feet to lift if up that can really help.

Yeah, with the motor under the bed, the chips really pile up.

Barry

Evenin" Berti:

I've had my Jet Mini for about two years. I run the livin" daylights out of it. I have had the Headstock get hot, but that was my fault. I tightened the Handwheel down too far. With the Lathe being belt driven, I don't see how the actual turning would cause a problem. If you put too much pressure on the piece while turning, the belt would slip. I have not been able to get the belt tight enough to stop or load up the motor. It sounds like you may have a bad set of bearings in the motor, but you didn't mention any abnormal noise. Is there any? The Other Bruce ================================================================

My Jet Mini has never overheated, but you ought to watch those shavings and clear them away before they build up. The motor-under-bed design is not the best as there is insufficient clearance for the chips to fall away on their own. They have to be cleared manually. You might want to use an air hose frequently. If you don't have a compressor, buy a can of "canned air" from the computer store. It works very well for clearing chips. (You don't have to listen to the compressor either!"

There was no noise. The first indication I had of something being wrong was a hesitation and slow start when I turned it on.

At any rate I've waited several hours now giving the motor time to cool down. I just tried it again and I'm afraid the motor is shot. It was slow starting and on the second attempt it started but ran in reverse.

I know that sounds crazy but it ran in both directions. At least it did for a few minutes. I removed the belt and it did the same thing running free. There was no noise but after about a minute I could see a lot of smoke coming out of it on from the headstock end and a very strong smell of buring plastic. Looks like I'll have to order a new motor if I'm to use the Jet mini cause even though it's low on hours that motor is bad.

It seems tha Jet used cheap motors in alot of their tools (cheap as in the internal windings). I have a Jet mini and, yes, the motor gets hot. I also have 2 Jet 1236 lathes and those, too, get hot...REALLY hot. A few months ago, I got a Jet 20" bandsaw (2hp, 220v) and after an hour of cutting it, too, gets hot....as in you-get-a-burn-it-you-touch-it-hot.

I had a Relient DD90 that I replaced the motor in with a Delta 1.5hp. I would go on a bowl blank sawing jag for 4 hours at a time. Never even shut it off. The motor BARELY got warm.

Peter Teubel Milford, MA

You may have a bad capacitor. If it is like my Delta Midi, there is a capacitor on the motor that can be seen from the rear of the lathe. I think this is always in the circuit as I never hear a centrifigul switch clicking when the lathe starts. Should be a lot cheaper to replace than the motor.

with the lathe and no ill effects suffered. make sure you vacuum out around the fan housing on the right end of the moter. and then take notice when you are turning to move the shavings away. Walter

Hi Bertie. My Delta midi experienced this very same problem a few months after I got it. The capacitor on the motor (under the hump housing) was shot. Since it was under warranty the entire motor was replaced, but if it hadn't been within the covered period it would have been pretty inexpensive and simple to just replace the capacitor. (Ought to be under $10.)

agree that the intial problem is probably a shorted cap (or if this is a cap start motor, a jammed centrifugal switch) - but if you let it run and overheated the windings, then you've let the magic smoke out and the motor really is toast. Start by removing the cap entirely and see what happens (don't leave it powered long). If it doesn't smoke, then turn it on again and spin the motor by hand (or spin first then power on wihile it's still spinning) - if it comes up to speed, and keeps running OK, then you are in luck, replace the cap. If not, motor is toast.

I'd suggest using a full sized washing machine motor if you can figure out how to mount it - don't remember in detail how the jet is laid out. the 'full sized' motor is both cheaper (probably free) and better

Hello Bertie,

Yes, I think the symptoms are those of a bad capacitor : hesitation at startup, running in either direction (depending on where you make it start by hand). Usualy, if not a mechanical problem, this is the weak part of this kind of motor. You are lucky because it is rather cheap (compared to the whole motor). You just have to buy a new capacitor (same value and voltage) and make the exchange. But ask for an electrician's help if you lack of enough electrical knowledge :-)

Hope you will turn again sooen :-)

Jean-Yves (from Toulouse / FRANCE), an electronician ...

That's why it ran in reverse. Capacitor boost determines direction.

Also an indication that the motor might have been overloaded. Capacitor kicks in when the motor tries to get up to speed. Had an undervoltage situation with the power company a few years back that ate the well motor and washing machine, but unless you're on a truly crummy Rural Electric, should not be a factor there.

As Bill noted, you can take out the cap, clean out the dirt and act as the starter. If you see a bunch of dark in there where the windings have lost their varnish, stop. If not, perhaps just a bit of smell, spin the motor and see how it does unloaded. Could be you caught it in time.

EXACTLY the same problem. A build up of shavings around the motor - BAD.

Cheers, Tom

Interesting. I have an "Old School" Jet mini, with one speed and a stretchy little belt. Half the time there are so many shavings around the motor I can't even find it, and it's been running flawlessly, almost daily, for nearly 3 years now.

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September 11, 2001 - Never Forget