The Rolling Stone

The physical structure consists of a number of parts such as the main sphere, training wheels to support the structure, the equatorial plate that holds all of the components, and others.

Polyurethane Drive Wheel – A four-inch diameter polyurethane that serves as the “wheel” of the system, moving in all directions. Being composed of polyurethane is provides a good amount of friction with both the ground and the friction rollers.

Spherical Caster Training Wheels – These provide stability to the entire setup while still allowing it to move and change directions easily.

Top Spherical Caster - This makes sure the ball stays aligned vertically with the rollers and acts as the system’s load bearing while still allowing the ball to spin and change directions quickly.

Exploded View of the entire structure with all parts

Details and Photos of the Structure (Click on the pictures for a larger view)

	All Parts: Here is an exploded view of the entire mechanism. each piece is near its mate, everything is nicely finished and ready for final assembly.
	All Parts Machine Finish: here you can see the machined surface finish of the final parts. this was done with a custom tool made up from a chunk of aluminum, some scotch-brite abrasive.
	Risers: These are simple risers to elevate the top plate from the equatorial plate, In a moment of insanity I knurled a portion of them, to improve their final appearance. both sides are drilled and tapped to accept 1/4-20 fasteners.
	Top Plate: Risers in place, the top plate is ready to be mounted to the equatorial plate.
	Top Caster platform: supports the top spherical caster