[Ether]

Originally Posted by Taylor

-edit- What if they're set at 45* angles relative to the frame a la killough so the rollers are in line with the robot?

Start with a standard mecanum wheel arrangement (Figure 1).

Swap the left&right rear wheels (Figure 2).

Toe-in the front wheels and toe-out the rear wheels (Figure 3).

Now you have a vehicle that can drive forward and backward (powered by rear wheels only), and has front-wheel steering, but cannot strafe effectively. Not an improvement.