[Joshua May]

Originally Posted by Max Lobovsky

That is not a problem. All electric motors I have seen make some sorta noise when stalling. (I think they make the same noise at all times, but it is usually covered up by the sound of all the rotating parts.) Some people on my team also seem to be afraid of it thinking something is wrong, but as long as you don't have too much voltage (and consequently current) going through the motor at stall, it is safe.

Yes, this happens with all electric motors. If you want to prove it to your teammates, take a drill and lightly hold down the trigger of it for a few seconds, you should be able to show them that the drill makes a slight "humming" sound, same as the CIMs.