There's no hand waving, I've given pretty much all the information I have. And the problem with 3 is that it takes up a lot of room. I told you, i'm building a robot, it has 9 motors, each one is a different size and does a different function. given that most of the motors haven't been chosen yet, there's not more to say. most of them, apart from 2, are small, yet-to-be-determined gearmotors, the other 2 are 12 volt window motors