Beginnings of my sphere robot

This is the sphere robot that I've been building for the last few months. I designed all the parts for the body and drive mechanism at home using OpenSCAD, and all the parts were printed on a Kossel Pro 3D printer that I built myself. The electronics are controlled by an Arduino Nano using software I wrote myself using existing libraries. The drive system uses a 6V 1200rpm geared motor. Steering is achieved with a continuous rotation servo connected to a bowl-shaped reaction wheel filled with sand to give it weight. The circuitry is powered by a 2S 7.4V LiPo battery and motor control is done via an L298 motor controller. The user controls the device with an inexpensive PS2 gamepad controller, which communicates wirelessly with a PS2 receiver in the drive system.

I've done three redesigns and rebuilds of the internal drive chassis before getting to this point. Then I discovered the motor I used doesn't have enough anywhere near enough torque to turn the 250mm (10 inch) ball. So now I will be upgrading to a much more powerful brushless motor and an 80A speed controller. This will hopefully give an output power of about 500 watts, which should be enough to meet my original concept of the sphere robot being able to do 60 miles per hour (100kmph). Scary speeds!

robot