British Engineer Creates Self-Balancing Bike on a Single Sphere

British engineer and YouTuber James Bruton has unveiled an innovative electric bike that balances on a single large ball, allowing movement in any direction. Known as the One-Ball Bike, this creation builds on Bruton’s previous work with a two-ball omnidirectional bike and showcases his distinctive engineering style.

Innovative Design and Functionality

The One-Ball Bike features a striking red spherical ball, approximately 2 feet in diameter, which supports the bike and rider. Surrounding this sphere are three omnidirectional wheels arranged in an equilateral triangle. Each wheel is powered by a motor capable of propelling the bike forward, backward, or sideways. The wheels also include two rows of smaller passive rollers, which facilitate smooth movement and distribute weight evenly across multiple points of contact.

Achieving balance on a single point is considerably more complex than traditional bicycles or Segway-style scooters, which typically stabilize on one axis. To maintain stability in both the front-to-back and side-to-side directions, Bruton has integrated a sophisticated control system that utilizes a microcontroller, specifically the Teensy 4.1, alongside an inertial measurement unit (IMU). The IMU continuously monitors the bike’s orientation, while a PID (proportional-integral-derivative) controller fine-tunes the speed and direction of the motors to keep the bike upright.

Power Supply and Control Challenges

The One-Ball Bike is powered by multiple lithium polymer battery packs, configured to provide approximately 50 volts to the motors. The bike’s frame combines robust aluminum extrusion with various custom-fabricated components, many of which Bruton has produced through 3D printing. This hybrid construction approach helps manage weight while enabling quick modifications during the building process.

Control of the bike deviates significantly from conventional bicycles. Instead of traditional handlebars, the design includes twist grips that allow riders to influence both forward and lateral movements by leaning and applying torque. Steering, however, presents ongoing challenges, as the ball does not function like a typical wheel that naturally aligns in a direction. Bruton has tested various solutions, including air-resistance control surfaces and even a foam wing to assist with directional bias.

Another unique aspect of this project involves addressing issues of static electricity. The friction between the plastic ball and the ground generates a charge that can interfere with the bike’s electronics, leading to occasional shutdowns during testing. To mitigate this, Bruton is exploring shielding and grounding solutions to enhance reliability.

Bruton’s commitment to an open-source philosophy is evident, as he has made all relevant code, CAD designs, and build documentation publicly available. This transparency allows other makers and engineers to build upon his work, fostering an environment of collaboration and innovation.

With the One-Ball Bike, James Bruton continues to push the boundaries of engineering and design, captivating enthusiasts and inspiring future explorations in the realm of electric vehicles.