Inventor Nick Thatcher was once in a dilemma on what to build: a Segway or a self balancing unicycle ? He later decided to do both but the unicycle came later.

He named the unicycle “Raptor”  because it looks like the head of a dinosaur on the side-view and it’s made from common materials found around: a chain driven wheelbarrow wheel powered by a 350W geared motor with 9:1 reduction gearbox, a pair of 12V 7.2Ah batteries wired in series, some PVC and polycarbonate, an IMU gyro and an Arduino UNO.