Rolling Ball Machines or Marble Machines

I've always had an interest in Rolling Ball Machines or Marble Machines but didn't quite come to the point of actually building one.But that has now changed,I'm in the process of making my first.

This one will be relatively simple,I'm using parts from a bicycle wheel and some other salvaged metal parts.

What won't be simple is the lift I'm building to bring the marbles to the top again and have everything working correctly.

While I'm working on my RBM,here is a video of some very beautifully made ones: