Information on building a directional transmission.
I needed a transmission that would provide power to two gears so that when the motor goes forward, the gears push the robot forward and when the motor goes backward, the gears turn the robot to the right.
I knew I needed a directional transmission (as seen here), but I was unsure how the outputs would translate to the motion that I needed.
I began building and here is an Ldraw file (right-click to save) and picture of the results. The white axles are the outputs for the transmission.
Just for fun, here is an mpeg movie of the Directional Transmission being disassembled.