Interesting what is recomended to me when I log into my Youtube-account. Today some Marble-machine-movie was, and I clicked it, and watched another one and another, and another… There seems to be a whole comunity of people making these! And they are quite interesting both mechanicly and the sequences and sounds they are creating with them.
Imagine the balls triggering small switches controlling another machine. Through seeing the ball moving down, then to be lifted up and the sequence repeated all over is a great visualisation of a programming loop.
Two great examples!