Brushless motor

[Leelosi]

Hi I'm new Ro brushless motors and was testing my gm 13.5 with no pinion on and it got really hot very quickly and was just wondering if this was normal if anybody could help me I would be very grateful as I don't want to damage my esc thanks guys

[Dave Dodd]

never run a bl motor without any load can cause irreversable damage!!

[Leelosi]

Thanks I won't be doing it again I only did it couple ov times think it will be ok ?

[RCMadShane]

I have had this on my GM... Turned out for me to be a faulty sensor wire causing a short... replaced wire.. Motor ran normal without building up any heat on the bench

[SlowOne]

As Dave says, never run a BL motor at full throttle without a load. They will rev to the moon, and the only thing stopping them self-destructing is the interaction of the electromagnetic and permanent magnet fields. They will work against each other to limit revs, but the energy has to go somewhere so it will come out as heat.

There might well be something wrong with the motor that causes a heat build-up before that situation is reached, but you will get there eventually. The mist likely outcome is a rotor that is damaged by too much heat. Once damaged it will never perform the same again, but the motor will still work. The least likely outcome, but the next failure cause, is that the rotor explodes. Ouch!