How to troubleshoot a geared hub motor

[vwrado]

I am trying to see if it's possible to fix a hub motor which I believe it to be a bafang g060. Currently when pushing the throttle, I can hear and feel one click from the motor. It doesn't move. I have tested another motor on this same controller setup and it works fine.

I have opened up the motor and did not notice anything out of the ordinary. All the gears look fine. What can be the culprit?

 

[docw009]

Probably bad Hall sensors inside the motor, or broken wires to them.

https://ebikes.ca/documents/HallSensorTestingFinal.pdf

Or buy one of these ebike testers. Pretty handy for testing sensors.

 

[vwrado]

Thanks! that is exactly what I am looking for!

For these motor, are the only things that can go wrong are the planetary gears or the hall sensors? There doesn't seem to be anything else.

 

[offGridDownUnder]

Bearings, magnets separating, water ingress and corrosion, breakdown of insulation, mechanically stripping the wiring due to inadequate torque arm mounting, broken spoke holes due to improper tensioning or external impact...

 

[Chalo]

Can you turn the axle smoothly with a 10mm wrench? It should turn freely in one directly and with resistance (but smoothly) in the other direction. If this isn't what happens, you may have a mechanical problem rather than electrical.

 

[vwrado]

Can you turn the axle smoothly with a 10mm wrench? It should turn freely in one directly and with resistance (but smoothly) in the other direction. If this isn't what happens, you may have a mechanical problem rather than electrical.

It turns in one direction but doesn't turn at all in the other direction

 

[Chalo]

It turns in one direction but doesn't turn at all in the other direction

Likely the motor is frozen from water intrusion and/or detached magnets then. Does it seem like it's been in the weather much?

Anyway if the motor can't turn, the controller will try to power it and then give up. That could be the click sound.

 

[docw009]

A geared motor only spins the motor when turned backward. There is a clutch in the gears that lets the motor nut turn when turning the tire forward. Normally, you feel the motor resistance when you spin it backward.

If it spins backward with very stiff resistance, but is OK forward, there are several possibilities. One is a short circuit in one of the motor phases. Another is a seized motor or stuck magnets like Chalo said, One more is that you put it back together wrong.

SInce the controller runs another motor, can't be problem there, but you might unplug the motor cable anyway to see if the wheel will spin, DIdn't see any obvious burning of the coils?

 

[vwrado]

A geared motor only spins the motor when turned backward. There is a clutch in the gears that lets the motor nut turn when turning the tire forward. Normally, you feel the motor resistance when you spin it backward.

If it spins backward with very stiff resistance, but is OK forward, there are several possibilities. One is a short circuit in one of the motor phases. Another is a seized motor or stuck magnets like Chalo said, One more is that you put it back together wrong.

SInce the controller runs another motor, can't be problem there, but you might unplug the motor cable anyway to see if the wheel will spin, DIdn't see any obvious burning of the coils?

It turns backwards easily but it will not turn the other way at all. There is a little resistant when turning backwards but it turns pretty easily.

I am not sure if this looks like its been in water or not but it doesn't seem like it.

 

[vwrado]

So I have taken out the planetary gears and the axle is completely locked up. Cannot turn the motor in either direction.

 

[E-HP]

So I have taken out the planetary gears and the axle is completely locked up. Cannot turn the motor in either direction.

Can you describe what locked up means? Are you saying the stator and the magnetic ring/rotor are seized together?

 

[vwrado]

Can you describe what locked up means? Are you saying the stator and the magnetic ring/rotor are seized together?

It was the magnetic outside ring was siezed up but I was able to break it loose with some force. I have then cleaned up my motor and tested it and it now turns! I will clean it up and put it back together and hopefully its back to normal.