Quote Originally Posted by cjsowry View Post
Several points during this video, you can see the bot turn slightly to the right after I let go of the stick. I don't know why, I'm guessing its the esc's, on the spec sheets it mentions the resistance is higher when in reverse. Always one of the motors/esc is in reverse when traveling in a straight line!! perhaps someone with more knowledge could explain!!?
To me it just looks like a trimming issue causing one side not to go into brake. Make sure to do a full trim:

Apologise in advance this may be a tad patronising, I just copied it from my custom antweight care sheets.

"Your robot should be controlled but it may not be quite right, the wheels may try and turn on their own or the flipper may not go all the way down. These are fixed with trims, they simply nudge where the middle position of the joystick. Your trim controls are the buttons immediately to the side and below the joysticks. If your robot is trying to steer left or right simply press the trim button in the opposite direction on your steering stick until it doesn’t, the same applies to the forwards and backwards. The easiest way to do this is to position the robot the right way up but with all wheels lifted off the ground, when you push forwards on the stick all wheels should start at the same time. If they do not make a note of which way the robot would be turning and click the trim in the opposite direction. Keep repeating until all the wheels begin turning at the same time. Now use the steering stick to turn the robot, again both wheels should begin turning at the same time. If they do not not if the wheel that is moving first is going forwards or backwards, click the trim for forwards and backwards in the opposite direction. Keep repeating until all the wheels begin turning at the same time. "

The resistance things *shouldn't* be the cause, that'd manifest as one side of the ESC becoming hotter. Unless the have a firmware difference in how they brake from forwards or reverse, but that'd be an odd thing to do.

Normally mechanically uneven drive is more a concern with bias timed motors like dewalts. Where one running backwards gets much hotter than the other, never noticed a power difference in my dewalt bot though.