Centrifugal Governor

This is a centrifugal governer. It works by cutting off power/fuel when a certain velocity is reached. The maximum velocity is adjusted by the pressure in the springs. More pressure = higher RPM. These old-school devices are where the phrase "balls out" originates from because the weighted balls on them would be fully extended at maximum speed.
I originally published this a few months back and decided it needed a couple upgrades. The graphs at the top indicate power input and velocity from left to right respectively.