Old KC motor - Problem after reassembly

wayback machine

wayback machine

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OK -
I have learned in my dealings with very old motors to have low expectations - This one proved me right, again.
Kingston Conley 1/2 hp capacitor start motor, 1940's vintage, wired 120V - One of those nice looking ones, with the wrinkle paint end bells.

I took it apart for new, sealed, bearings and a re-paint. Scrupulously marked the wiring, covered any cracked insulation with shrink tube, and very carefully re-assembled it - It's wired to a drum switch (also carefully marked and rewired). It did work correctly before my attentions, but had bearing noise, and looked really ugly - Mounted on the machine, it's out in the open.

It went back together apparently fine, and the rotor spun smoothly and coasted a good while, when spun by hand.
Now to the problem - It starts with a brief groaning noise before it spins up, AND, the direction it chooses to turn is kind of random - I can hit the drum switch to forward, and sometimes it will turn forward when switched, but sometimes, it will start in reverse when switched forward, and vice-versa.
If it's coasting down in one direction, and switched opposite, it will start up turning the original direction.

So, is it a capacitor issue, or field winding, or am I basically just an idiot, for even trying this with a motor this old?
Not world ending, as I do have other motors, but I'd like to know if anyone might have an idea what I did wrong.
 
I don't think it's the switch - It's a new, US made, 6 terminal drum switch, wired exactly same as the old, worn out one, that came with the motor.
It certainly could be the capacitor, though - I had to fiddle with it to get the motor back together, and the wires exiting from it are old.
Some connection in the capacitor could have broken internally, I guess, and I didn't see it.

That's the problem working on these really old motors - It often takes 3 hands to reassemble them, reaching in, and re-soldering connections, etc, etc, with the motor half apart on the bench.
I'll have to decide what to do - Continue on with this one, or just cut my losses, and use one of my newer (but less attractive) motors.
 
Post some pics of switches (old and new) and motor so I can see your hardware
It sounds like the start circuit is open- did you replace the drum switch during your rebuild?

I've had people say "It's the exact same drum switch" only to discover that it's different

Do you have a multimeter? Some way of checking continuity?
 
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I'll see about a photo, but I doubt it will show anything useful.
At this point, I'm leaning toward it being the cap - I had an old Craftsman motor that did sort of the same thing when the cap failed, starting random direction, when switched on.
The drum switch contacts and construction are identical to the old one - I think, if was a crossed switch connection, that the problem would be consistent, not totally random, like it is now. But, I've been wrong before.
 
Well, I tried swapping in a known good cap, of the same capacity - No joy, same problem.
I guess there's something internally wrong with the old KC motor, likely caused by me, and I don't know half enough to try and fix it.
So, I'm moving on to the new motor, and starting a whole new thread, because I am totally confused by the drum switch wiring, and as I've aleady killed one motor............
 
I was wondering if you wanted to open the motor up again, but moving on is ok too
You could jumper the cap and check for continuity at the drum switch but you may end up opening the motor anyhow
 
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