When someone is accused of ‘reinventing the wheel,’ it’s meant to signify that they wasted time developing something that already exists. And yet Ralph Waldo Emerson famously said “Build a better mousetrap, and the world will beat a path to your door.” Clearly, there’s some room for improving on the work of others. So James Bruton applied Emerson’s philosophy to actual wheels, and using 3D printing, he made some incredible ball wheel prototypes that will change the way you think about wheels.
James worked off of previous ball wheel research done at Osaka University where two hemispheres rotate independently around an axis, making a spherical wheel that can roll in pretty much any direction. Of course, there’s more to it than that, and James does a wonderful job of using 3D printing to not only fabricate these ball wheels but also of leaning on 3D printing to demonstrate how the wheels work. He even prints an incomplete version that lacks a critical feature (another small wheel on the end of each hemisphere that runs parallel to the axis) just to demonstrate that the wheel can’t really function without that feature.
3D printing enables him to make intricate models that are purely for explaining something to his Youtube viewers. If he had to machine that same piece, it would be too costly and time consuming so he likely would have resorted to an animated diagram or wordier explanation to convey the information, which would not have been as effective as his printed model that plainly reveals the directional friction problem.
The final prototypes James prints perform better than even he was expecting. He used PLA to print the rigid parts, with the main hubs housing push-fit bearings. TPU was used for the treads and the end-wheels to increase traction. Because of the thick treads and the gap between the hemispheres for the axel, the ball wheels don’t look like they would roll smoothly, but looks can be deceiving. James printed a full set of three wheels as well as a chassis to test how they roll, and they glide like ducks on ice. It almost feels like an optical illusion how smoothly the platform rolls.
This technology of ball wheels is still miles away from being used on passenger vehicles but they have a promising future in the robotics and automation industries. In the meantime, I bet they’d make an excellent office chair.