[Ether]

Alex raised an interesting question about running the kit motors at 24V instead of 12V.

It depends on where on the torque vs speed curve you intend to run them.

Let's say you're running an FP at 70% NLS at 12V. If you jack the voltage up to 24V and keep the same torque load, you will get twice the speed (and therefore twice the power output) for the same I^2R heating. You could change the gearbox to reduce the output speed and get twice the torque instead. So in this case it's not a matter of heating, it's whether or not the FP (and the gearbox) bearings and rotor can withstand the higher speeds (40% higher than 12V NLS), and whether the dielectrics can withstand the higher voltage transients. This analysis ignores secondary effects such as eddy current and hysteresis losses in the magnetics which may become non-negligible at the higher speeds.