James Bruton’s Latest Build Is a High-Speed Balancing Act

From custom e-bikes to ride-on Transformers and AT-ATs, James Bruton knows how to get around in style. The latest addition to his collection of unique DIY vehicles is an Omni-Directional One-Ball Bike (or "Ike") that presented him with all sorts of new engineering challenges. This vehicle drives around on a single balance ball. If you have ever tried sitting on one of these, you know that it takes plenty of effort to stay upright — so just imagine building a vehicle on top of one!

But that is exactly what Bruton did. Unlike his earlier two-ball design, Ike has to balance in both directions at the same time. The machine rides on a single large ball cradled by three motorized omni wheels arranged in a triangular frame. Each wheel was custom-built after commercial omni wheels overheated and created too much friction. Bruton rotated the drive wheels vertically so they would cooperate instead of fighting each other at speed.

Each wheel contains 216 bearings and two banks of small rollers, with aluminum cores for strength and 3D-printed TPU tires for grip. The wheel assemblies mount to a rigid chassis made from 40/40 aluminum extrusion, forming a triangular box structure that supports the rider and keeps the ball centered.

Power comes from three ODrive S1 brushless motors rated up to 2 kW each, connected through a simple 1:1 belt drive. Six 6S lithium-polymer batteries are paired in series to produce roughly 50 volts, then paralleled for capacity. A large contactor and emergency stop switch handle safety, while separate batteries run the electronics.

The control board is a Teensy 4.1 microcontroller paired with a BNO086 inertial measurement unit that constantly measures pitch and roll. Static electricity from the plastic ball forced Bruton to coat the electronics enclosure with nickel shielding spray to prevent random glitches. A PID control system interprets the sensor data, speeding or slowing the wheels to counteract any lean and keep the rider upright.

Riding the bike requires some cooperation from the human onboard. Hall-effect twist grips on the handlebars intentionally shift the balance point — up to about ten degrees — telling the machine to lean forward and roll in that direction.

Steering, however, turned out to be a more difficult problem to solve. With only one freely spinning ball and vertically oriented wheels, the bike has no natural yaw control. Leaning like a motorcycle simply didn’t work. Bruton’s temporary solution was quite inventive, if not entirely practical: a large foam wing held out to one side. By creating aerodynamic drag, the wing physically pulled the vehicle into turns while it moved forward.

Like most of Bruton’s creations, this isn’t one that you can easily reproduce for yourself. At least we can watch the video to experience the Ike virtually.