One of my favorite ways to build a manually released rolling ball sculpture is to make it semi-automatic. Load the long queue at the top with a handful of marbles—or as many as you like—release the first one, and gravity takes over from there.

This sculpture has three tracks. One sends the marble through a tall vertical zig-zag, another through a loop d’ loop, while the longest route includes a flat spiral, horizontal zig-zags, and plenty of back-and-forth movement through the sculpture.

The real trick is what happens at the bottom. When a marble reaches the end of its run, its weight presses a handle connected mechanically to the release at the top. That action releases another marble, which travels down and repeats the process. No motor, batteries, or electricity are required—just gravity and a little mechanical engineering.

Release one marble at a time and the sculpture can continue running on its own for nearly 16 minutes. Or release several together for more action, with multiple marbles moving through the three tracks at once.

The sculpture runs with colorful 1-inch glass marbles, adding flashes of color as they travel through the stainless steel tracks.

100% stainless steel, TIG welded.