Manchester Makefest is going to be running this weekend and one of the collaboration projects they're attempting to run is Amazeballs. Several people build modules that contain marble runs for 27mm pinballs, the modules are brought together at the faire and the machine all works (in theory).
Marble machines being kinda my thing and a desire to help people with interesting ideas Just Add Sharks ended up signing up to make 2 modules for the machine. Dominic has made one and here is my module.
My first attempt to make something fancier failed completely, the balls are pretty big and heavy and sheer momentum was smashing the machine apart during testing so I went back to the drawing board and came up with this passive machine. The 68mm drop between start and finish isn't a lot to work with but it is possible to make something interesting that can run that length.