Limitting motor torque

[JesseK]

Originally Posted by Hawiian Cadder

because the robots only run for 3 min at most, power draw, and efficiency dont really matter.

In many regional finals, you have a 6-minute match cycle time. If you have a high-current match, then your battery may not have enough time to fully recharge before the next time it is used. In the worst case, it could take 6 matches to make it to finals -- most teams (though I'm sure not all) I've seen at competition have between 4 & 6 batteries. The question then becomes, can your battery chargers properly keep up with your demand?

Match-for-match in elims (or anything in quals) where high-current situations aren't common, sure I'd agree with you in most* scenarios. Yet I'd hate for you to put yourself in a bad situation come competition day because you thought something was totally negligible.

* In situations where multiple mechanisms must perform quickly (i.e. high-power) and heavy game objects are involved (2008 is a perfect example), then electrical efficiency should be considered (IMO). Other considerations are PID-hold algorithms where an arm must move to a position and use back-drive current with extra current to hold itself in position. 2006 also saw at least one team implement a PID-hold software mechanism on their drive train in order to keep from being pushed while they shot at the goal (I'm not sure of the team, but it's in the "Behind the Design" book). All of the mechanisms on the robot can accrue large amounts of power draw (mAh) over the course of a match if you're not careful; so designing the drive train to use a little less current isn't a bad thing.