Restoring an Old Electrical Motor

[brentcz]

excellent tutorial, fantastic pictures, great use of on-hand materials for seating bearings. Thanks for sharing. Your efforts are appreciated. Now on to hooking that beautiful motor onto the main attraction - the drill press.

brent cannady

[skizzo]

Bob Vaughan said:

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Motors of that vintage and type are particularly fussy to restore... You overcame a lot of existing condition problems not always found on electric motor rebuilds.

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Thanks folks. Bob is right... this one ended up being about as problematic/complex as any (not that there are that many) that I've ever done. All the more surprising because the external condition upon arrival looked and ran about as nice as something this old ever gets. It just goes to show that you never know about something until you open it up.

This definitely wasn't a one-hour clean up and bearing change project like you sometimes find. There were several notable hassles that I don't recall ever having to deal with before:

- the bearing in the blind well
- the cap wires that come through an endbell casting
- having to pull the starter lead out of the j-box
- having the center band come loose

But it also shows that even something with that level of challenge and complexity can still be done with some attention and care. And the end product is way, way worth it, since these are such nice motors. LOML saw it when done and was stunned, even after having seen quite a few of other motors and such before.

Much appreciated.

[Warptboard]

I enjoyed this thread! Thank you Skizzo

[Buckaroo]

Outstanding Bill! , and thanks for that shot of the centrifugal switch. I'm pretty sure my plate bypasses that switch so I'm not sure how it even runs, but it does. I have more investigating to do but thanks for steering me on the right path.
Love the end bells. Now all I have to do is find some of that VHT High Temperature Wrinkle Plus Black.
Excellent write up.

[skizzo]

Buckaroo said:

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thanks for that shot of the centrifugal switch. I'm pretty sure my plate bypasses that switch so I'm not sure how it even runs, but it does.

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So this is the shot of yours, right?



I suppose it's possible that the fiber plate on the switch might be worn down to the point that it (or part of it) go inside the brass contact ring. But if even a little bit of the plate catches the brass ring, it's likely to exert enough pressure to close the contacts when it spins down. If it is smaller OD than the ID of the brass ring, I'd bet you could figure out a way with tape or something similar to build up the perimeter of the fiber plate so that it doesn't get inside the contact ring.

That wrinkle paint is the bees' knees, eh? I had no idea such a good replica would be available... I just found it at my local chain Borg-substitute hardware store. Good luck.

[Buckaroo]

that's the one ....when I first took it apart.
I haven't cracked it back open yet but IIRC, it's almost like that plate was cut out of the one below. It is smaller diameter than the switch but maybe it's offset enough that it hits the ring.
Might even be just hitting it on one side Didn't think about that.

That paint is awesome. I still haven't painted my bells and I was half thinking about applying it in a "stipple" fashion ( my wife was watching some decorating show where they were doing that) I wasn't really looking forward to trying that.

is this the stuff? Looks like it's a good choice for the application.

[skizzo]

That looks exactly like it, IIRC. I think there are different colors, so be sure to find wrinkle black. Like somebody upthread said, try it on a practice piece first. Per the instructions, it takes a fairly heavy coat, applied in layers, timed fairly close together. I've had other paints crinkle on me by accident, usually because it was applied to thickly. This says to do that on purpose.

[SteveV.]

I have really enjoyed reading this and the DP post Bill. Very informative and great pictures for those of us who are visual learners.

Steve

[Buckaroo]

Found some of the VHT today. Was at autozone trying to find bulbs for some trailer lights so I walked by the paint section and it was right there.
Hope I have half as good of results as you did.
Thanks for all the info.

[NBeener]

Truly an excellent tutorial. Many thanks.

I'm nearly finished with rebuilding the 1/4 HP motor on my 1956 DeWalt MBF RAS.

I'm replacing the circuit breaker, and soldering new leads on the end of the winding.

I'm also (rather related) replacing both runs of power cord with a cannibalized 14/3 extension cord.

Incidentally, I think you got lucky. My cord side bearing came out of the end bell with liberal use of PB Blaster.

What did NOT happen easily was ... removing the back bearing from the armature. I think it had galled in place, over the years.

Ruined two (cheap) chisels, AND exhausted my (what I thought was significant) supply of curse words.

But ... in the end ....

NBeener: 1
Bearing: 0

For the record, I had a local motor shop give me a price on re-winding the motor. Because of the cost of copper, they guessed about $700.

Guess what I'm NOT having them do