Posts: 45
Threads: 8
Joined: Jan 2013
City: Toronto Ontario
I've completely dismantled it, cleaned, oiled, examined, and can't see any issue with it. The windings don't seem to be damaged in any way, everything spins very freely and smoothly. When I first got it it was even weaker than it is now, but I still can't get it to 78 rpm.
I'm not sure about these things but I'd guess the fact that it's an old Canadian 25 cycle motor would mean I could probably never get it spinning at the correct speed?
Here's a few images of the beast....
[Image:
http://i835.photobucket.com/albums/zz278...f7c367.jpg]
[Image:
http://i835.photobucket.com/albums/zz278...3697af.jpg]
Posts: 4,612
Threads: 51
Joined: Sep 2008
City: Sandwick, BC, CA
Is this the original or the replacement motor? If anything a 25 cycle motor should be trying to take off down a runway on 60 cycle as AC motors are governed by line frequency, if it's too slow then the mechanical governor I see on one end may have something to do with it.
Regards
Arran
Posts: 45
Threads: 8
Joined: Jan 2013
City: Toronto Ontario
This is the original motor. I've tried running it with the governor completely backed off and it still wouldn't pick up enough speed.
Even if I were to get this motor running freely, I'd never get it to spin at 78 rpm, right?
It would naturally want to spin faster?
(This post was last modified: 03-22-2013, 10:55 PM by
Mr Grumpy.)
Posts: 4,612
Threads: 51
Joined: Sep 2008
City: Sandwick, BC, CA
I don't see any solution here other then to try finding a 60 cycle replacement for this changer, that may take some time. The only real way to see if the motor is working properly is to find someone with a VFD (variable frequency drive) to test it with, but everything that I have read and heard is that an AC motor should run faster at a higher line frequency not slower. There were pockets of 25 cycle service in the U.S, most notably in upper New York state around Niagara Falls, I think there were some in Pennsylvania as well, so it isn't a uniquely Canadian thing. In fact much of Canada was always on 60 Cycle power, like in Quebec and the Prairie provinces.
Regards
Arran
Posts: 1,394
Threads: 69
Joined: Oct 2007
City: Linn Creek, MO
I think the issue is impedance. If you increase the frequency, you also have to increase the voltage. But, then the motor would run to fast (if there is no governor). VFDs control both frequency and voltage.
Steve
M R Radios C M Tubes
Posts: 7,215
Threads: 266
Joined: Dec 2009
City: Roslyn Pa
Maybe you could use a bucking transformer to boost the voltage up on the motor.
Terry
Posts: 45
Threads: 8
Joined: Jan 2013
City: Toronto Ontario
I'm going to keep my eyes peeled and my fingers crossed and hopefully I'll find one in the future.
for now I'll either put the geared motor back in or try and modify a motor and idler assembly to fit.
@Arran, Thanks for the additional info, I had no idea about the 25 cycle outside of Canada. Learn something new every time I log into this place!
(This post was last modified: 03-23-2013, 09:04 PM by
Mr Grumpy.)
