> 2:48 the fact that we're not using gravity

Of course you're using gravity on a device built out of little slopes, just as the Turing Tumble is.

Add a hand-cranked marble lift to a Turing Tumble and the two are much more similar. One is gate cranked, while the other is circuit cranked.

While the Roons device has much more mechanical overhead for distributing the clock signal, it does allow for more looping paths.