[Andrew Blair]

Basically, the concept is to simply slam the drive module around a pivot 90*, so as to afford a sort of reversable drive- in one position, you drive length-wise, slam it the other ways and you drive long-wise. The problem with the locomotive type linkage is that you basically cannot complete the entire turn in such a way. Either you straighten out the piston and it locks itself from further motion in the opposite direction, or you stop it prior to locking, and you don't get the full 90* turn.

This full angle is crucial to keeping full driving ability once the modules are turned: If the wheels aren't parallel, especially with a high traction wheel like we use, you grind your wheels and get horrible efficiency.

And Tristan, the arrows aren't really important, the linkage will need to go back and forth, but the piston may pull or push either way- no problem.

If such a linkage is possible, it would allow for a very quick reacting, smooth, "slam steer" type drivetrain. Push a button, and you're going sideways, almost instantly. And you get to keep the full traction of a four wheel drive.