Radio Controlled Hamster Ball
This was created as a proto-type for the Swarm Burning Man Project.
It consists of an 11" hamster ball from the pet store, a Tamiya worm gear
power unit, and standard R/C radio, servo and speed controller.
I used 3/16" birch for the main support panel, and a 3/4" x 3/8" maple stick for the swing arm
to hold the lead counter weights. The Main Axle is a piece of 1/8" all thread.
The power comes from a 7 cell nicad pack.
The unit steers by moving the weight box off center via the R/C servo. I used a robust giant scale
servo 'cause the swinging weight creates a lot of force on the servo gear train. There's about
a pound of lead in the weight box.
The ball rolls great. Top speed is about 12 mph on flat ground. Steering is positive, but not quick.
It takes awhile for the ball to respond to the moving mass. I have to exercise care when
steering... the servo is very quick, but fast motions cause the ball to oscillate back and forth.
Here's the weight at maximum deflection.