Hello, I want to build a machine that will detect (and thus measure) the rotation of a roller skate wheel as it sits on a roller skate. The purpose here is to get a quantitative measurement of the bearing units quality. The plan is to build a machine that will apply a standardized force vector to the wheel and then time how long it spins a result. Can anyone suggest what is the best kind of sensor to use to detect the rotation of the wheel? If this is not the correct forum for this question I apologize. Thank you, \Lon.