Youtuber LittleBall Creations creates complex marble mazes using copper wire that are first bent in the proper shape, and then soldered so that they stay in place. Watch below as the marvel travels the lenght of the maze on one side, and then reverses its course when flipped over.
From LittleBall Creations:
The Caged Ball Rolling Ball Sculpture ( Number 15) .Full video of single track maze winding down inside a cube sculpture . The ball is caged so that it cant escape, the sculpture works either way up. the sculpture can be displayed on its side also. Built in Lockdown 2021.