The prototype Artie and I chose was a a trebuchet. We thought a trebuchet would be a nice simple prototype that would be a able to shoot decent distances. When we started the prototype we got a real good headstart since we were the first to complete our cutting and the first to start cutting. When we started putting the actual thing together we kind of slowed down and the other groups started to catch up to us. Throughout the construction of the trebuchet there weren't that many mistakes apart from the occasional splitting woood when we were nailing and sometimes the nail would split and get stuck in the wood. But there weren't any major mistakes and most of the time peices would fit together how we measured it and there were no disagreements. When we tested it in the corridor the result of the trebuchet actually had a pretty good distance. For our sling Artie brought in some leather which lookks and is pretty good. He aldo brought in some hocky pucks which are pretty good counter weights.