Ballmobile

A number of the "ball-vehicle" ideas that have been floated here recently reminded me of an idea I'd thought of once.

The mental picture: A beach ball with a collection of cables inside arranged something like the coordinate axes, on which are mounted sliding weights. As the weights move, the center of gravity shifts and the ball rolls. Simple.

Now, more detail:

Start with a large ball. Run a taut cable on the inside down the middle. Mount on it a 10 kg. contraption that can move back and forth along it, using a small motor and wheels.

Then run two more cables parallel to each other and perpendicular to the first, one on either side. On each of these, mount a 5 kg motorized sliding doohickey.

Finish with two more cables on the outside of the LAST two, and perpendicular to BOTH previous sets of cables. Again, each should have a 5 kg doohickey.

A computerized system moves the weights back and forth in a roughly sinosoidal motion to continually keep the center of gravity ahead of the point of contact with the ground, applying a torque to the ball and causing it to roll.

That's the essence of the idea. Run with it!