[Al Skierkiewicz]

The reason behind dropping the center wheels is due to the current drawn by the drive train with all the wheels on the carpet. If all wheels are high friction types (in all directions) then the current on the drive motors skyrockets to near stall current. With a CIM motor drive that is 129 amps per motor. With four motors pulling over 400 amps, the power supplies feeding the Crio and radio start to fail or at least disable Crio output. In some cases the hopping robots you see are due to the wheels actually breaking friction with the floor and in others it is due to the Crio shutting down the outputs. In worse case, the Crio reboots and you all know how long that takes for your individual robot design and software. The decision to keep all wheels on the same level is a risky one that each team must make based on their own robot and wheel design. You can minimize the current by altering the turning radius in software, using omni wheels, dropping the center trucks, or dropping a helper wheel to lift the front or back wheels during a turn.