Marble Maze with 4 floors

This is a marble maze puzzle game where a marble must travel a path from the top level to reappear at the bottom of the cube. 

The marble must go through 4 mazes (shown with a plan at the top level) and can be followed through the openings on the side.

The marble has a diameter of 18 mm. This can be scaled to work with a larger or smaller marble.

The original marble maze can be found on https://www.freelaserfiles.com/ together with a series of other free lasercut-files. The makers of this site were so kind to give me the opportunity and to grant me the rights to convert this originally conceived puzzle into a 3D-print model and to publish it on MakerWorld. Thans a lot!