I built and filmed this machine in only one week (40 fails). The rubber bands in the last video gave me the inspiration to do more with those.
It is shorter than usual because I preferred to do few impressive tricks and focus on quality and how well it looked rather than complexity or length. Also because tricks with rubber bands are unpredictable and unreliable.
As you saw I learned from my mistakes and put the most sensitive part at the beginning with the sliding trampoline, so that the vibrations of other tricks can't trigger it too soon
The most complicated trick was the stack marble effect at 0:10 (check https://www.youtube.com/watch?v=2UHS883_P60 to learn more about it). The spacing between the two marbles had to be exactly the right one for it to work. This trick caused 90% of the fails.
My favorite part and the main idea of this video is as you can guess the loop. It's very satisfying. And what impresses me the most is the simplicity of the launch system, just 2 dominoes and a rubber band. And surprisingly it works almost every time