I did this prototype to see how using moving Animusic drums would look on a Marble Machine and It´s much more fun watching the drums play when they move compared too being still. The drums are counterbalanced by weights, no springs are used. I also did this to try a potential setup of the drums on the machine and something like this kind of makes sense. Its a good viewing angle where you can see all the action from the audience perspective. I learned a lot of other useful things from this experiment and enjoyed playing Animusics crazy song swell :) Enjoy!