Electric motor quit - please help diagnose

[Don Burt]

I was using the 1950 vintage shopsmith to drill little holes in glass. It was running along fine for maybe fifteen minutes, and suddenly quit silently. Just like I powered it off. The pulley and motor shaft turn easily by hand. But it won't run now or make a hum noise like its trying to run. It used to have an overload switch on it, but it was removed and replaced with a piece of cable running out to an old ceramic lamp socket with a 20 amp fuse in it. When the motor quit, that fuse was hot to the touch, but the copper strip in the fuse wasn't melted. Can anyone recommend a diagnostic procedure for this old motor? (its a Mongomery Ward...cool). I'm resigned to taking it apart, but aside from worn brushes or melted stuff, I wouldn't know what to look for. That hot fuse seems wrong.
Thanks.

[Brock]

Hmmmm . . . sounds like an electrical problem.

Thomas Alva

[Dale Grundon]

Shorted winding should have blown that fuse. So there is probably an open winding. Try an Ohm Meter for diagonostics on the winding.

[Haydo]

Could be that the brushes need replacing and the rotor(?) cleaned up.

-Haydo

[Haydo]

As I finish my wine and peruse your question I notice you have already come to the brush problem. It's been a big day at the shop(unfortunately not at "THE SHOP") - Haydo

[Brian and Jenny Blanthorn]

I was using the 1950 vintage shopsmith to drill little holes in glass. It was running along fine for maybe fifteen minutes, and suddenly quit silently. Just like I powered it off. The pulley and motor shaft turn easily by hand. But it won't run now or make a hum noise like its trying to run. It used to have an overload switch on it, but it was removed and replaced with a piece of cable running out to an old ceramic lamp socket with a 20 amp fuse in it. When the motor quit, that fuse was hot to the touch, but the copper strip in the fuse wasn't melted. Can anyone recommend a diagnostic procedure for this old motor? (its a Mongomery Ward...cool). I'm resigned to taking it apart, but aside from worn brushes or melted stuff, I wouldn't know what to look for. That hot fuse seems wrong.
Thanks.

Did U have the correct fuze ??

Hot fuze does not sound good

Brian

[Tony Smith]

Don,

Does the motor have a thermal fuse? When motors get "too hot", the thermal fuse is supposed to open. After a cooling-off period, they will run again. Try plugging it back in and see if it will run this morning. If it does, then it may have been a thermal problem. Make sure any cooling vents in the motor frame are clear and blow out the motor with compressed air.

Tony

[Bruce]

Lood and see if you have a round button somewhere on the motor. If you do press it in and see if it resets. It may be hard to push so don't give up too easily.

[jim simmons]

Shorted winding should have blown that fuse. So there is probably an open winding. Try an Ohm Meter for diagonostics on the winding.

Also, The fuse could be open and look like it is good. I have had this happen more than once in my former life..
Use an ohm meter or just replace the fuse..

Anothersuggestionboy(Jim)

[Don Burt]

Shorted winding should have blown that fuse. So there is probably an open winding. Try an Ohm Meter for diagonostics on the winding.

Also, The fuse could be open and look like it is good. I have had this happen more than once in my former life..
Use an ohm meter or just replace the fuse..

Anothersuggestionboy(Jim)

Its turns out that the fuse was indeed burnt-out. Bypassed it and the motor started, so I just had to replace the fuse. I took the motor apart and cleaned it up. Ran it for ten minutes, and the fuse was'nt hot to the touch, so I think it will be OK for a while. THanks to everyone for the help.