Take 29, and the Rube Goldberg project worked.
It took some serious last minute changes, a steady hand on the dominoes and more patience than I thought Perry had.
Phew!
Tomorrow, we'll edit to get it into some format she needs (description of the project and the transfers of energy etc).
[eta] We have better video from the camera, but for some reason I decided to record that try, and got some of it.
Click to view