[Rick TYler]

Originally Posted by Eric Scheuing

The only good catauplt would be a tribuchet, but if you used that, good luck aiming/firing at the goal consistently.

Actually, a trebuchet would be an accurate and consistent, but really impractical device for a robot. Trebuchets rely on a counterweight to pull the arm down. In a robot, where every ounce is critical, anything relying on a counterweight is a Bad Idea. Likewise, I cannot think of any practical way for a robot to reset the sling of a trebuchet after each shot. A rotating wheel, or the energy of a wheel imparted to a belt, is a much more appropriate mechanism for a robot. Even a mangonel or oranger would be easier to build than a treb, even if you have to design for the end-of-stroke shock.