[GeeTwo]

I remember thinking the same thing years ago. Why can a 40A breaker in a house can power a couple of ovens, but only one CIM, and that for a few minutes? Remember that power = VI (ignoring for now the phase issues in AC), and that house voltage is nominally 120V, or 10x the nominal voltage in a robot (or most automobiles).

One way to get a good 40A switch is to use a home circuit breaker at this rating. They are not really made for switching on and off, but they do work like that if needed -- at my church, there are no light switches in the sanctuary, we literally throw the breakers several times a week.

During this build season, we wanted a similar thing, though we were not worried about proportional speed controls, just off/on. We put together a "cable" with an Anderson battery connector at one end, a breaker and a button style automotive starter switch in the middle, and two pair of Anderson Power Poles at the other end. It's an easy way to verify that each motor is running the correct direction, provide prototype power to a pickup mechanism, and we even used it as the initial "proof of concept" of our drive train over the defenses by powering one CIM on each side of our chassis (had to swap one side or the other, of course) with the robot at about half weight.