Need help rebuilding motor

[Knothead]

Originally Posted by cyclebender

Batteries are Crown CR 165. Voltage was obtained using a 12 volt charger hooked to a pair of batteries in series. 6 batteries total. Then used a 36 volt golf cart charger on 5 batteries in series. Sounds complicated, but its not, very simple but time consuming.

It's also NOT the correct way to charge those batteries! You cannot charge 5 8v batts with a 36v charger. Your batteries are technically dead, if you have charged a 40v pack with a 36v charger. A 40v pack should read @ 42.5v at full charge & 40.35 at 50% (which is as low as they should EVER be discharged). At 37.8v, they are DEAD, which would explain why it won't run. You need to get 6 6v batts, before you smoke the controller (if you haven't already!)

[yurtle]

Originally Posted by yurtle

Pics would help. A green Scotch-Brite might fix the corrosion, or it could be be WAY too far gone to fix.

Info most won't want:

The rotor and stator are both composed of stacks of laminations that are supposed to be insulated from each other. They are a "special" steel alloy, and are coated in some kind of insulating material, similar to magnet wire. It controls eddy currents.

If the laminations are so far gone that they are corroded together, it may be toast.

EXPERTS,
Please correct me if I'm wrong. I work on AC transformers more than I do brushed DC motors, so correct me if I'm wrong. When I tore mine apart, the brushes were within tolerance, so the only thing I really did was replace the bearing.

[Thatsme?]

Originally Posted by yurtle

EXPERTS,
Please correct me if I'm wrong. I work on AC transformers more than I do brushed DC motors, so correct me if I'm wrong. When I tore mine apart, the brushes were within tolerance, so the only thing I really did was replace the bearing.

I am not an expert.
I cleaned all of the carbon from brush wear out of the inside. As mentioned before be really careful with the epoxy or varnish type substance that is the insulation. I replaced the bearing and tighter the posts in the case. If you replace the brushes you should resurface the commutator. Inspect everything, springs wires, etc. Put a new rubber bumper in the input shaft coupler even though I am not sure what it does.

[yurtle]

I forgot, I did clean up my commutator with a ScotchBrite pad.

[yurtle]

Originally Posted by yurtle

EXPERTS,
Please correct me if I'm wrong. I work on AC transformers more than I do brushed DC motors, so correct me if I'm wrong. When I tore mine apart, the brushes were within tolerance, so the only thing I really did was replace the bearing.

OK, I looked at my old motor, and without pulling the rotor, I was able to confirm that the stator cores ARE in fact made up of laminations. If the laminations are corroded together, then they are in fact "shorted". If you can clean them up with a ScotchBright, they may be OK.

The stators are bolted to the motor "can", so if needed, they can be removed for clean up.

[cyclebender]

Thanks for all your help Yurley
I was able to tap out the armature from the end cap. Have ordered new brushes and bearing. Should be able to clean all the other components using a electrical cleaner and scotch brite.

[yurtle]

I LOVE ScotchBright. Once your stuff is so bad it needs emory cloth, it could get more complicated.

I also love solvents, but you gotta know what you're applying the solvent to, and make sure the solvent won't dissolve stuff like rubber or insulation.