A family member ashed about an endless marble run toy she'd see on Tiktok and I decided to try and generate one using OpenSCAD based on this way to build a 3D knot from slices.

The STL files are generated for 16mm marbles or ball bearing balls and should be printed in PLA+ as pushing the balls in requires a bit of force.

If you decide to run the code yourself, note:

• A glass marble is inaccurate by ca. 0.5 mm, measure in multiple axis and take the highest value

• Generating the final STL may take more than 10 minutes depending on hardware

• The generated STL may need to be cleaned up, I've run the uploaded files through meshlab