The goal for my junior year Design Competition was to cross the gulf between two raised platforms, go down a very steep ramp, and knock over a cup at the finish line.
My team this year was my ME partner from last years competition and an Applied Physics friend. We decided that that rather than building an overly complicated robot to finish each step as litteraly described in the layout, we would build a device that would launch itself over the gap and then roll to the finish line, knockin over the cup.
We decided on a sphere form so that it would roll in a strait line that we point it in. To launch, we decided that that the sphere would be compressed in on one side, and that the launch would be powered by a compressed spring releasing the device back to a sphere.
It was very dificult to find a ridget sphere that would work, but building the automated spring release mechanism and the hardware for holding the spring compressed was some good, fun mechanical engineering. Our first tests were beyond our expectations, and Caught on Camera.
A problem we ran into was not getting the sphere to launch at an agle without an angle base to launch from. Because the rules specify that all part of the robot have to cross the finish line, we had to drag that base behind us on a string. That, and the difficulty in aiming a sphere added a lot of room for deviation. Although our device was very well received, due to dumb luck on our part we did not place.
My good friend Kevin created a documentary of the days leading up to and covering the competition.