First of all, kudos to all the teams who have managed to build a catapult not only capable of simply holding/controlling the ball, but launching it into the air. Our team considered this at the beginning of the season, and decided that it would essentially be too complex (something we have had problems with in the past).
So, we decided to build a relatively simple forklift mechanism with a rotating "grabber" that the ball simply rests in (A teammate has the inventor drawings
). A winch pulls a cable (winch is just a plastic attachment to a motor (window i think) that lifts the "grabber" to 6'4" (forklift is bent at start, pneumatic piston straightens). At that height are two 10" stroke, 3/4" pistons that push the ball onto the overpass (12 pts. at end of match) we then move a few inches, push again (on the ball on the overpass) and the ball comes off the overpass, scoring a hurdle.
While we have no "catcher" design, we can regain control easily, and perhaps even "pass" the ball to another robot (hard though).
In short, our team is all lift.