Dedi Kroya has sold some of the coolest kinetic rolling ball sculptures we have seen. This wooden marble machine is also worth a look. Once you activate it, you will see the balls roll from the top to the bottom over pre-made tracks. They are moved back to the top automatically, so the fun never ends.
This piece has a natural wood base. It runs on a AA battery. It has a brass track. This marble machine measures 150x100x100 mm. You can find out more here.