ShopSmith Blowing Fuses

[mountain4don]

I have been using my ShopSmith pretty heavy this morning. Ripping some 3/4" oak lumber on the table saw. And the motor is pretty warm. And then I switched to using the router making some 1/4" slots in the oak, going maybe 1/8" deep at a time, running the motor at full speed. And this last time I was about half way down the slot and had to turn it off to swat at some wasps attacking me. And now it won't start up and run up to full speed and blows the circuit breaker. Its pretty hot out there in the shop, about 95 degrees too. I just took out a fan and put on it. So, what am I doing wrong? I just put a new 2-bearing quill in it and lubed the speed control sheaves as described in my manual.

[dusty]

I have been using my ShopSmith pretty heavy this morning. Ripping some 3/4" oak lumber on the table saw. And the motor is pretty warm. And then I switched to using the router making some 1/4" slots in the oak, going maybe 1/8" deep at a time, running the motor at full speed. And this last time I was about half way down the slot and had to turn it off to swat at some wasps attacking me. And now it won't start up and run up to full speed and blows the circuit breaker. Its pretty hot out there in the shop, about 95 degrees too. I just took out a fan and put on it. So, what am I doing wrong? I just put a new 2-bearing quill in it and lubed the speed control sheaves as described in my manual.

I don't know that you are doing anything wrong; however, your description of the symptoms does not sound good to me.

I would let it cool down and then pull it out and open it up. You may have smoked some windings.

BTW Ambient temperatures should not be a factor. If I could not work when the temperatures were in the nineties my shop time would be reduced about 1/3. My shop temperatures have been in the 100s for a couple weeks now with no relieve in sight for weeks.

[mountain4don]

And if I have "smoked" some windings, what is the solution to getting it back running again? I called them fuses that were blowing but in actuality it is a 20 amp circuit breaker in the power panel.

[fredsheldon]

And if I have "smoked" some windings, what is the solution to getting it back running again? I called them fuses that were blowing but in actuality it is a 20 amp circuit breaker in the power panel.

I would guess there should be some good used motors becoming available from members on this forum who have or will be upgrading to the PowerPro.

[mountain4don]

Is this a "normal" motor that I can go buy at the local motor supplier or is it some sort of different configuration so that I just can't take the parts off of this one and put it on a new motor bought locally?

[reible]

Before you go too far I'd start by putting a sanding disk on and rotate by hand while changing speed back to slow (with machine unplugged). Now plug it in and see if it starts.

If it starts then shut down and think about when the last time was that you cleaned out your headstock. If it has been a while then maybe now is the time to do it.

Did you happen to smell any electrical incense when this first happened?

Ed

[JPG]

1) The shopsmith motor is both unique and proprietary.

2) The shopsmith motor (1 1/8hp) was designed to barely not trip a 15A circuit when started at slow speed setting.

3) That allowed the largest motor for the typical house wiring of the day(Early 1950's).

4) With the advent and more common use of breakers and 20A circuits the run it down to slow prior to shutting off(so it starts more easily[quicker]) practice has become essentially ignored.

5) At 95 ambient, ripping, and high speed routing will cause the motor to get quite warm internally.

6) Starting while 'hot' will take longer than when 'cooler'.

7) A longer startup time will cause 20A circuits breakers to trip(might the breakers also be warm also). Does the breaker panel feel warm?


So do as Ed suggested(manually crank the speed down to slow) and try starting again.

Also It may be that the motor has an accumulation of dust internally that will cause it to run hotter.



Hopefully it is a matter of excessive heating and starting up at high speed that is causing the breaker to trip and the motor has not suffered permanent damage.

[mountain4don]

Before you go too far I'd start by putting a sanding disk on and rotate by hand while changing speed back to slow (with machine unplugged). Now plug it in and see if it starts.

If it starts then shut down and think about when the last time was that you cleaned out your headstock. If it has been a while then maybe now is the time to do it.

Did you happen to smell any electrical incense when this first happened?

Ed

No, I didn't smell anything odd. I felt the motor housing and it was real hot, and kind of smelled around it, but nothing smelled burned. And I can turn the shaft over ok so nothing seized up in there. And I put a big fan on it and went to lunch.

[mountain4don]

1) The shopsmith motor is both unique and proprietary.

2) The shopsmith motor (1 1/8hp) was designed to barely not trip a 15A circuit when started at slow speed setting.

3) That allowed the largest motor for the typical house wiring of the day(Early 1950's).

4) With the advent and more common use of breakers and 20A circuits the run it down to slow prior to shutting off(so it starts more easily[quicker]) practice has become essentially ignored.

5) At 95 ambient, ripping, and high speed routing will cause the motor to get quite warm internally.

6) Starting while 'hot' will take longer than when 'cooler'.

7) A longer startup time will cause 20A circuits breakers to trip(might the breakers also be warm also). Does the breaker panel feel warm?


So do as Ed suggested(manually crank the speed down to slow) and try starting again.

Also It may be that the motor has an accumulation of dust internally that will cause it to run hotter.



Hopefully it is a matter of excessive heating and starting up at high speed that is causing the breaker to trip and the motor has not suffered permanent damage.

The breaker panel is on the South wall facing the sun, and it is real hot also. When I opened it up to flip the breaker it was real warm on my hand. After running a fan on the motor for awhile, and doing what you guys suggested, I turned the shaft while slowly turning the speed control down to about half speed. And after cooling it with a fan for awhile I plugged it back in and it started up ok. So I finished doing my work with the 1/4" router bit and then ran the band saw on slow speed for awhile to finish the project. And it seems ok now. But I guess when it is hot outside I can't run it at a high speed to start it. The headstock was opened up and blown out with air and vacumed out real good just a week ago when I first started using it. My mother gave it to me after my father died last year. And I lubricated the shafts and put a new 2 bearing quill in it since it is a 1981 model with the one bearing quill, which wobbled pretty bad when I tried to run the table saw or a router bit with it. But those functions run fine now.

[JPG]

Glad to hear our 'wishful thinking' prevailed.

There is no vacuum that will get the dust out of the motor as effectively as compressed air blowing through the motor.

When you get a break, take the motor out and clear it. Truth be known, taking it apart is the only really effective way to get it all out.