In my first year we had a class rube goldeberg project. We were split into pairs and each had to design and create an interesting step in the machine that was going to be reliable when the camera was rolling. Fortunately our pool table worked 95% of the time!

 

Two balls sit in two differant tracks and are pushed down the tracks by the cue ball striking them, we did our best to cover the tracks with the green felt but only so much could be done to ensure the balls went down the tracks every time.