Quote:
Originally Posted by Andrew Lawrence
In normal driving, it does take a bit of load off the other motors, but in a pushing match where all motors are giving maximum output you have a larger chance of tripping the breaker with a 6 motor drive than a 4 motor drive. The solution is to just not get into heavy and sustained pushing matches.
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This is not a universal, blanket statement. It's less correct than the statement you were referring to actually, which is pretty much always true. With a 6 motor drive, all other things equal, each individual motor will draw less current than each individual motor in a 4 motor system. This makes it harder to trip the 40 amp resetting breakers, which tend to trip first in a 4 motor drive. The tradeoff is that,
at certain gear ratios, you are more likely to trip the 120A breaker. The most vulnerable edge case is an extended pushing match when geared above ~10 feet per second. A low gear for a 6 motor 2 speed drive can certainly be geared low enough to prevent this from basically ever happening in a 2 minute long match.
This tradeoff is something teams should carefully analyze and play with when deciding to use a 6 motor drive. Study the breaker spec sheets, both 40A and 120A. Experiment with different motors or robot cooling systems. Run a shifter and push in low gear. There are a lot of ways to try and mitigate this potential pitfall.
(By the way, consider running a low gear that is traction limited with each motor drawing, say, 30 amps instead of 40, if you are extra paranoid)