Every year at BoardMeeting we have a snowball launching contest. This year I built a catapult.
I put together an intial mockup of the catapult in about half an hour. I never actually got round to producing the actual catapult, so the prototype was pressed into service on the trip.
A couple of test fires got decent results, but the third test fire was catastrophic. the arm split lengthwise and required some significant repairs with a bag full of zip ties. This worked well enough to get 2 or 3 actual shots off. Unfortunately more structural failure was imminent as the screws holding the frame together proved to be too weak for the impacts. They sheared and let down the whole team.
The Catapult may work if re-engineered, but I haven’t yet decided if I’m going to bring this design back for 2013.