This Rolling Ball Sculpture was built for Colorado College as a physics demonstrator. The idea was to use the stored energy of the balls and the different elements of the RBS to put several physics concepts on display where you can actually watch them happen.

There are two 3D-printed gravity wells. As the ball gets closer to the center, the slope becomes steeper and the ball accelerates. Two balls enter the wells together, so you can also watch how they interact with each other while circling the center. After exiting the first gravity well, they roll directly into the second.

The loop d’ loop has one of my favorite backspin exits. As the ball shoots out of the final inversion, its backspin works against its forward motion, causing the ball to slow, stop and then reverse direction before continuing down the track. There are also several large dips where you can watch momentum carry the ball back uphill after each drop.

A ball-collecting tipping arm holds three balls before releasing all three together onto a large curved sheet-metal plate. The balls circle, collide and interact with each other before eventually finding their way out at the bottom. The tipping arm itself demonstrates leverage and the fulcrum effect, with the three balls eventually overcoming the counterweight and tipping the arm.

Another track sends a ball through a jump and onto a long straight section with a ruler alongside it. Each ball follows the same path and takes the same jump, but they don't always land in exactly the same place. The ruler makes it possible to see both the average jump distance and the natural variation from one run to the next.

One of the more unusual elements is a long 12" tipping arm. It accepts a ball while vertical, and the weight of the ball sends the entire arm swinging back and forth. It can continue swinging for a couple of minutes before finally slowing enough to accept the next ball.

Three small spirals in a row send the ball spinning down through their coils, demonstrating the same kind of circular motion seen in the gravity wells, but in a much more controlled path.

This was a fun one to build because the RBS isn't just demonstrating physics — the entire machine operates because of physics.

100% stainless steel, TIG welded.