[fox46]

Does anyone have any information on which FisherPrice motors have internal protection and what kind - ie: Thermal/Current etc?

Furthermore, is the internal protection device considered integral to the motor? Are we permitted to remove the internal protection?

One of my teams powered up their shooter this weekend running two FP motors on an AM double doozie gearbox and it appears there is overload protection built into some of these motors. We tried both with the motors from this year's KOP, as well as the 9015 (I believe.. could have been 9012s though, I am having trouble remembering) and observed similar behavior as each motor would cycle on and off independently from each other (visible by observing the arcing brushes) two or three times until the wheel reached operating speed (takes about 3 sec). This is running them directly off a battery. The flywheel is a 10"x6" aluminum ATV rim directly driven off the double doozie and does indeed suck quite a bit of power until it is up to speed but the load is not unreasonable IMO. The motors while running are warm but not what I would consider hot as I can easily hold my hand around either one with no discomfort. The protection method does not seem to be thermal as they would cycle on/off with a cycle time of about a half second during wind up from a cold start which does not sound like a thermistor type of protection to me rather than a bi-metal type circuit breaker. I suppose it is also possible that the protection device in one motor is weaker than the other and through the action of cutting out, it is dumping more load on the other and causing it to trip. I can appreciate having internal protection on these but it is going to be rather annoying writing a startup function for the shooter.

We tried powering the 2012 motors through both combination of poles on the back of them thinking one pole would bypass the protection device however, it did not work.