It’s the world’s simplest electric train! Why not make it with children to enjoy science?
Ever used magnets in a project, and had to fiddle around with it until it worked? Then you should have used a magnetic viewing film, so you could see the problem directly.
This is probably the easiest magnetic propulsion system in existence, and so easy to build!
Can your 3D printer do this?
The future doesn’t need builders and mechanics, everything will be built by robots!