[Daniel_LaFleur]

When using a 2 motor skid steer (tank steering) drive system there is a number of things you need to consider.

1> Traction of your tires: too much traction means you cannot steer.
2> Wheelbase: The longer your wheelbase, the more power you'll need to turn.
3> Pushing: most robots out there will be able to push your robot around.

To avoid some of this you can:
1> use omniwheels on either the front or back set of wheels as this lowers your sideways traction.
2> use casters on front or back (same as above).
3> use High traction wheels in the back and low traction wheels in the front.
4> Change the orientation of the frame to shorten the wheelbase.