This project began as the unicycle robot that I also have listed in my portfolio. This second iteration is a challenge to create a balancing robot that rests on free spinning wheels. The robot will balance using a flywheel with an acceleration-based pitch balancing system that I have been designing the controller for. Yaw control will come from the ability to roll the flywheel and use the inertia of the flywheel. Once the robot balances well I may add a propellor to the back so that it can drive and move while still maintaining the non-actuated wheels.

The first version of this robot involved a BLDC motor attached to a heavy flywheel made of a wheel acting as the weight and an adaptor to connect it to the motor. A 2S LiPo battery connected to a BEC (Battery Elimination Circuit) was used to power the controlling microcontroller and IMU, in addition to an ESC that powered the BLDC motor.

The first spin test failed rather quickly when the plastic adaptor piece to connect the wheel to the BLDC motor ripped apart at high speeds.

I then redesigned the flywheel to be a metal washer with a stronger 3D printed adaptor that survived the spin test (now performed in a brick enclosure). Unfortunately the test revealed that the inertia of the flywheel was causing issues with the ESC leading to a loss of speed control and the BLDC motor was far too powerful for the use case.

The next step for this project will be to use a lower-speed likely brushed DC motor for the flywheel and possibly use a PCB that I designed for my snake robot to power the robot.