System of three balls controlling a globe

Question

I'm looking into the possibility of creating a motorized globe controlled by three balls in a base, with the globe sitting on top of the balls. (There is a reason.) These balls would rotate, controlling the globe.

I need to have control on three axis, hence the three ball system.

I'm having trouble finding this concept on-line. Anyone know what to call it, so I can research it further?

Answer 1

Dont' know what you'd call it but I've got a picture of a globe sitting on top of three computer trackballs( I find them far better than mice)

Maybe use Gimbals for the three supporting balls . There's nothing stopping you putting extra "beams" between each bearing to fill in the space, and to keep the globe mounted level.

Otherwise- if you take the ball out of a MECHANICAL (rather than optical) mouse/trackball you'll see it has two rollers which are used to measure the balls rotation. You could drive those rollers to move the supporting ball.

All you need to do then is drive the 6 motors so that a point on the surface of the globe will moves in the intendend direction.

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If the globe is really light you can maybe support/trap it in a jet of air. Slow the air flow on one side and the globe will spin.