Stiff motors when unplugged

When our motors are unpowered and unplugged from our motor controllers, sometimes they will be extremely difficult to turn(more difficult than normal) and sometimes they will turn with moderate force. What might be the problem? A couple of weeks ago we had a new motor that locked up when unpowered because the electric motor was actually loose inside its plastic housing but that doesn’t seem to be the issue now.

So how many out of all of your motors were unplugged and locked up? This shouldn’t be happening… Have you attempted unplugging the motors as you are rotating them? Like I mean could you see if that can fix the issue?

make sure your motors leads aren’t touching when they are unplugged and you are rotating. This will cause them to brake and be difficult to turn

Wow, I never knew this. Is this the equivalent of sending 0 power when its plugged in? If so, then what’s the equivalent of just non-powered/coasting? (Not moving but also not braking)

It depends upon the drive electronics and how they have their re-circulation diodes and such setup

Most likely, you’ve shorted your motor, that is, near where the wire goes into the motor, beneath the black rubber thing, the wire casing has come off and the copper inside of the red wire is touching the black wire. When this happens, the motor is essentially unusable until you fix it; using a shorted motor can cause motor controllers and cortex ports to catch on fire. Fortunately, the fix is pretty easy; just put a piece of electrical tape in between the wires so that red is no longer touching black.

Just remember that you motor becomes a generator when you turn it. Current needs to go someplace and it will make whatever voltage it needs to to make that circulation happen. So you can damage stuff.