[fox46]

My response to this whole thread is... WHY?

Basically it's about trajectory. You want the flattest one so that when aiming, your shot is less dependent on the distance to target. This means the driver doesn't have to worry about positioning of the robot and the software doesn't have to calculate a firing solution as rigorously. Furthermore, the shot is less dependent on the condition of the game pieces. In 2013's case, a linear trajectory was desired because math is hard. Take a look at video of 2013 in aerial assist- the same design philosophies were in use. On the FIRST Robotics Canada facebook page, they recently posted a ton of pictures of GTR East with a few close-ups of 2013's machine. While I can't speak too much to the development of the mechanism as I am in a purely advisory relationship with the team this year, I do know it required a number of prototypes and testing to see what the limits of compression, friction material and inertia were.