[EricH]

See if you can locate any tech specs for the only "linkage drive" ever used in FRC--"Twitch" was the robot name.

4 omni wheels mounted in swerve module-type devices, rotated 90 degrees by a single pneumatic cylinder. It was used in 2008 for making turns at the ends of the field.

That might be worth trying out in the offseason; the "swerve modules" could be just large pieces of C-channel or box tubing (or, if you have any around, the 2010 KitBot risers with some extra well-placed holes).