[thefro526]

One of your issues you may be experiencing is the manufacturing differences in DC motors. No two motors will ever spin at exactly the same speed and unequal weight at friction will cause you to drift of course. Btw you can not wire 2 motors to the same speed controller. I would suggest to make your system as efficient as possible and then if that doesn't work either program PID or some other closed loop or get your drive to compensate for the drift. Out robot drifts to the right this year so every time i drive I always give the right joystick more of a push than the left.