Gearbox Dimensions for the Chiaphua Motors

[Joe Johnson]

It is possible to pull a lot of current with either the Skil-Bosch Drill motors or the Chiaphua motors. Each have stall currents above 100Amps.

This should scare you some, but not too much. The 30 Amp breakers will keep you from drawing this much for very long. Also, you should design your drive system so that it is difficult/impossible to actually stall your drive motors (for example, you may choose a drive system with a high enough gear ration such that the wheels slip before the motors stall).

What will happen when teams have 5 motors available that can each draw above 100 amps? This is somewhat of an open question, but I suspect that things will be not much different than they were last year. Some teams will do a bad job of picking ration, they might have some problems, but most teams will have no problems at al.

Joe J.

P.S. From my discussions with Tom Frank (Naval Undersea Warfare Center) when he was testing the 60 Amp breakers, I very much doubt that many teams will have trouble with the 60 Amp breaker tripping. Basically, he tells me that if the breaker we any bigger (say 80 Amp which is what I was advocating), under almost all condititions, the BATTERY would be the current limiting device not the breaker. Because I know that Tom is a careful person and a good engineer, I predict that the 60 Amp breaker tripping will be a non issue, even with the extra motors in the kit.