Quote:
Originally Posted by Ari423
I'm going to go ahead and disagree with this statement. I just did the math and the only two motors that are over the 54A limit that a 40A breaker can provide indefinitely at max power are the CIM and 775pro. Both of these draw about 65A.
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54A is on the very outer edge of the current breaker tolerance band; I would not rely on your mechanism being able to consistently pull exactly 54 amps. If you have a slightly out of spec breaker, or your mechanism has marginally more load than you expect (various ineffiencies, etc), you'll have a bad time, especially since that doesn't even factor in voltage drop. It is reckless to give people the general advice that they should expect and plan for their motors to draw 54 amps under design load.
With that all said, the other motors with max power drawn at more than 40 amps include the mini-CIM, BB-775, BB-550, etc. Basically, any motor you should be climbing with.
The other danger with gearing at exactly mass power is that once you tip over that critical point, you're getting less and less efficient performance out of your motor as your load increases.
You also don't want to run fan-cooled motors at 50% stall generally; it's not great for them to run that hot. Be conservative here; you're not going to win the World Championship with a climb that's 300ms faster than your opponent if your motors smoke.
There's some benefit to climbing quickly, to a point, but this isn't a race, and you just want to complete it reasonably quickly. You can easily get there with 1 CIM / 775pro geared conservatively for less than 40 amps under load - add a second if you really want those sub-2s climbs; don't overwork 1 motor.