One of the results for hilbert curve marble tracks, mentioned elsewhere in the thread, was a video showing how to make one in blender, which has a physics engine so it can simulate it pretty well.
https://www.youtube.com/watch?v=8YeXyUNCnhM
I'd imagine that the 3d-printable models could be imported into blender, so it's 'just' adding balls and motion to the lift.
