Homemade self-balancing unicycle uses an Arduino to keep upright

On the whim of a coin flip, Nick Thatcher once decided between building a homemade Segway, or a self balancing unicycle. Even though the powers of fate chose the former, Thatcher's thirst to build wasn't quenched -- he built the one-wheeled scooter anyway. The Raptor looks a lot like a Ryno unicycle built from spare parts -- a chain driven wheelbarrow wheel powered by a 350w geared motor, a pair of batteries wired in series, some PVC and polycarbonate, an IMU gyro and an Arduino UNO -- all hobbl...