Like a Segway, but sideways!
Take two 350W electric scooter motors and two wheels. Attach them under a board of thick plywood, add bike chains. Connect the DC motors to a 2 channel motor controller like a Sabertooth 2×25.
On top of it, in a project box, install an accelerometer and a gyroscope hooked up to an Arduino running a PI regulator. Repurpose a Wii Nunchuk controller to command the rotation of your meal. Do not forget to add a deadman’s switch on the Nunchuk. Serve indoor or outdoor with the biggest LiPo battery you can find. Bon appétit!
How does it work?
In its simplest form, this is a self-balancing robot as you can find tons on Youtube. The regulator constantly tries to keep the skateboard level.
When you lean right for example, the accelerometer and gyroscope detects it. The regulator commands the motors to move to the right to bring back the center of the wheels at the vertical of the center of gravity of the skateboard. If you weren’t resisting it, the skateboard would retrieve its horizontal position. But because you force it to be tilted to the right, it will accelerate in this direction until it reaches top speed. To brake, you just have to slightly tilt it left and it will smoothly.
The Nunchuk’s joystick is used to change the heading, by applying a differential command to the two motors (just like a differential drive robot, or a tank).
To get on the skateboard, you just start from a tilted position with one end on the ground, balance it yourself (like a balance board) and enable the regulator with the deadman’s switch.