Change rotation on DC motor
 

The motor brushes are angled for clockwise rotation from the drive end, 12 degrees as an estimate.

I know that I can reverse the polarity on the armature to change the direction, but from what I've read that would wear the brushes more quickly, spark a lot if the brushes are advanced, and likely have a lot less torque.

So is it a big deal to dis-assemble the motor, remove the brush holders, and mount them for reverse rotation?

If that is not over my head, how would I figure out the correct advance for the brushes in the new direction?

Or should I just reverse the armature leads and accept the reduced performance and life of the motor ... since it presently works as an electric motor right now and there is a good chance that it will never work again if I take it apart?

If the brush holder angle is adjustable then reversing the angle is the right way to go. On the other hand, if the brush holder is riveted together, contact the mfg and try to get a reversed brush holder. Running a motor with angled brushes in reverse can cause the brushes to catch on the comm bars and destroy the motor.

Of course YMMV Bart.

I am a bit tentative about dis-assembling the motor. My track record in putting things back together and having them work again is not ... stellar ... that's why I'm not a mechanic:D

The manufacturer was bought out, or went under ... some time in the 1940's or 1950's (depending on your source) - so no joy on contacting them for parts.

I found a lot of issues with the wiring of the motor inside the 'conversion' I bought. So far, I'm trying to determine what the wiring SHOULD be so I can verify that it is running the wrong way for the transmission.

Thanks for the info - your solution is the least ... daunting .. so far.

Hi Again, Any chance of posting a picture so we could see what you are dealing with? I personally am using a VERY old Baldor motor. So old that when I got it the field and brush leads were wire bundles that were run out the side.

Pictures of DC motor
 

Pictures, as requested. I only have one with the motor inside the car. The rest are out of the car.

If a close up would help, let me know

Does this help?
 

I have not been able to locate much info on this, but the motor/generator may be this this model (courtesy of 'major' on DIYelectriccar.com:

"jack & heinz #g23 aircraft generator"