Originally Posted by
synap2012
hmmm.... there must have been something else wrong. Can you explain in detail why a motor would expload and speedo give out, just by testing it on the bench????
In a brushless rotor the magnets are glued to the shaft. Most have a failure point in the RPM range. You will most likely never achieve this range if the motor is under load. However on the bench there is nothing preventing it from spinning up past what it is designed to take. When you do you will have failure in rotor, which will most likely short out the stator windings and cause failure. It doesn't explode like in a hollywood movie. But the rotor does delaminate. I have had one rotor fail while running. It was not catastrophic as only a small portion of nickel plating came off. But is was enough to seize the front bearing and grind the whole thing to a halt.
Running the motor up and down for a couple of seconds though should not cause the ESC to get too hot to touch. I have been testing mine right now and it just gets a little warm. Unless I put the timing on 12 then it gets hot but I can still touch it.