Got finally my new rear end assembled (new motor mounts and drivetrain) and went out for a test ride, got about 200 meters from my door when testing out my brakes it seemed to lock-up my other side motor. Rolled to a stop and noticed that the direction of my other motor was changing it’s forward rotating direction (using only forward and brake, no reverse), so clearly there is something weird going on, but I haven’t seen or heard of this before.
I then re-detected the motor through the VESC tool, but results we’re identical to earlier detected motor values.
I then went out again and I was able to get the problem to appear again before setting off, so I shot this little video reproducing the problem.
NOTE. when the motor starts running in the wrong direction it has a lot harsher whine to it, then compared to the correct direction.
The lock-up might be explained with that if you coast for a moment and then try to accelerate or decelerate and the VESC for some reason thinks the motor is running in the wrong direction and therefore locks it. Only happened when acceleration or deceleration commanded. Coasting didn’t have any problems.
Background and possible leads:
Broke one of my motor mounts couple of weeks ago. Motor did take some hard knocks as seen by the scuffs on the bell, but I straightened the bell on the axle so it wouldn’t grind on the stator teeth, so there can be possibly damage in the motor leads, except that if there was a short between 2 phases the motor would bind constantly and I don’t expect it to turn as well as seen on the video.
Other possibility is that the drive stage of the VESC took a possible spike when the motor ripped off, but I then proceeded to ride to work and back on a single setup using the VESC from the broken mount side, as shown below. I didn’t change anything else for the single running except increase motor and battery currents to get going with a single motor.
One thing I did notice though after the motor had snapped off and I had stopped, looked at the situation, cleaned up and attempted to limp ride myself back home with the now single left side Slave VESC’s motor is that it kept juttering/stuttering under acceleration and braking and was not able to keep going. Now whether this was caused by the right side Master VESC losing it’s motor which then caused it to “freak out” and command all the Slave VESCs weirdly because it didn’t have a motor connected to it.
Personally it would seem to be something with the VESC settings, because if the motor leads were short circuiting it probably shouldn’t even commutate properly, or there should be clear indications of the leads shorting from vibration if the phase insulation was nicked slightly with sharp stutters. The VESC HW itself also seems to be good, as if it was a HW problem I doubt it would commutate reliably at all or detect the motor with identical settings.
I’m gonna try switching the motors around and seeing if the problem does or doesn’t move with the motor.
Otherwise all questions, suggestions and theorycrafting are welcome at this point.