Reassembly of grinder motor

[HMiller]

I.bought a grinder at a.high school auction, and it worked for a few years. However it started throwing sparks and such, so I took it apart and replaced the wires to the lights.

When I put it back together it just buzzes, and taking it apart reveals i bent the centrifugal swtich. After 3 tries it is time to get help .I can't figure out how I can put this back together on my own.

The problem is I can't line up the shaft and push everything together with just two hands. Since the ends are what supports the motor it can't be held fixed, and the shafts are too short to block it up and push the ends on, at least not any way I can think of.

I know it went together once, but I can't think how. Anyone have experience they can share? I'm temped to bring it in, but that is probably more than a new grinder (with the cheap sheet metal rests)

 

[markba633csi]

Can you block up the motor with the shaft pointing down and assemble it that way?
A picture would help us see what the problem is you are having- does it involve the centrifugal switch mechanism?
Sometimes a piece of wire can hold parts in place which is then pulled out just as the motor goes together




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[matthewsx]

I’ve had luck using wire, string, or whatever to hold things. Then pulling it out when it’s together.

Agree, a picture would help.

 

[HMiller]

Finally found some time get some pictures. looks like I should just replace the switch (where to find one?), but i'm still not sure how to get it together. You can maybe tell the the switch is screwed to the outside end, and the centrifugal part is on the shaft. The bearing doesn't come off the shaft without taking the switch off, thus the awkward angle of those pictures (you probably can't make anything out them, but ...)

If anyone can give some hints other than standing one end (as I have now ) that would be useful.

 

[tq60]

There should be some pins or screws through the 2 holes in the switch to secure it to the end cap.

Looks like screw holes below it in the photo

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[HMiller]

There are screws to hold it on. If you look closely you can see the metal of the switch is bent a little in that picture, enough that the switch never makes contact and engages the capacitor. Every time I attempt to assembly the motor the shaft touches the switch at some point and bends it. I can straighten it by hand, but only if I take the motor apart and then I have to reassemble it.

 

[markba633csi]

Can you not assemble from the other end? - in other words, have the switch end down and lower the armature thru?
There must be a way- not to say it doesn't require some careful moves
Maybe sliding it together horizontally is a better approach?
If we could see how you are trying to do it we could offer better advice

 

[pontiac428]

I feel your pain. It probably does not help that the slip ring is worn thin as foil so it no longer appears to be springy. I so much prefer centrifugal switches that lock to the shaft with a screw for R&R.

If you know who made the motor, you might be able to find replacement parts or an interchange list online. Switches are nothing special, they just need to handle the load and engage at the right RPM.

Try to set the slip ring in the bell end and slide it over the shaft first, it should go back together easy.