Trouble-shooting Low Traction

[alecmuller]

I finally had a chance to double-check the setup just now:

1) I re-weighed everything, and it's definitely 148-149 lbs (there are 3 pavers and an EXTRA 14 lb battery).
2) The CG is fairly close to center of the robot (all 4 wheel pods are the same or left/right symmetric), the pavers are evenly spread, and the batteries are evenly spread. I'm not sure where the CG is height-wise but the robot isn't tipping so I don't think it matters.
3) It turns out ONE of the wheels is slipping, and the other 3 aren't. These 3 suggest I'm either not driving them at full power or there's far more friction in the system than I accounted for in my calculations (i.e. like ~70% losses instead of 20-30% losses).
4) The battery is fully-charged. The motors are commanded to full power within the limits of my hardware. More detail on this: each motor is driven by a Talon SR hooked up to a 2014 power distribution board with 40A breakers. The Talons are commanded by an Arduino Uno controlling them as a servo (i.e. 0-180 where 0 is full reverse, 180 is full forward, and 90 is stop). They were all calibrated WITH the same arduino.

I suspect friction is a big culprit (I made most of the parts in my basement with low tolerance tools). I might also have to figure out a way to test the torque of an individual CIM to see if the arduino is driving it with full force too, though.

I'm open to other ideas for tests & troubleshooting, though!