How I Make Track Switches for Rolling Ball Sculptures

This aluminum fixture helps me make the track switches, or track splitters, used throughout my rolling ball sculptures. A track switch takes an incoming marble and sends it onto one of two different paths, adding variety and unpredictability to the movement of the sculpture.

I made track switches many different ways over the years, usually holding the pieces in position by hand while I TIG welded them. When I met Bill Bethke many years ago, he was a retired machinist and asked if there were any tools he could make to help me build the parts I use in my rolling ball sculptures. I told him about the difficulty of keeping all the pieces properly aligned while making track switches, and this fixture was his solution.

I use this block on almost every rolling ball sculpture I make. The different-sized center grooves allow me to use two sizes of tubing depending on the mechanism I'm building.

Here's how it works: a piece of tubing fits into the wide center groove. Two stainless steel rods are then laid across the tube in the longer, shallower grooves. The fixture holds the center tube and both rods securely in position while I TIG weld the pieces together.

It's a simple tool, but it's indispensable in my shop. It gives me a fast, repeatable way to fabricate track switches and keeps the parts properly aligned while they're being welded.

Bill passed away in June 2012, but I still use the tools he made for me regularly. Thank you, Bill. Your expertise and skill continue to be a part of the rolling ball sculptures I build today.