Marble Machine 8x6x5" No.4
The balls go through rings which are the track spacers. The machine has a switch that divides the balls into two tracks with features like a flat spiral, zigzag, balls on track, many twisty turns and a helical spiral. It's made from copper, wires are joined with soldering. Natural-looking beech wood base. Electrical components are engraved at the bottom. The speed is adjustable.
Full size with acrylic cover box: 200x160x130 mm. It has 12 mm transparent glass marbles.