Last year with 1493 we built a custom frame, the sides contained the transmission (a custom 2 speed based off the AndyMark shifter) and the wheels, the two sides were connected by 1 inch square tubing with 1 inch solid aluminum cubes welded on the ends. We threaded the cubes and connected the sides with counter sunk bolts. this allowed us to quickly remove one entire drive module and replace it with a spare. Allowing us to make repairs without having to miss matches of work directly around the robot.
I am going to attach a picture of the chassis, if you have any questions feel free to ask.
