My worst FIRST experience came while we were prototyping our hook. There's this guy (adult actually) on our team that's a little difficult to work with. He had this idea for a hook: There would be a tall (like really tall; about 4') screw onto which another shaft would be screwed. Spinning the screw would cause the shaft to rise, and a hook would be on the end.
So he made his hook, which turned out to be this 50+ pound monstrosity. The screw turned at about 40 RPM, which meant it took about 5 minutes for the stupid thing to extend fully.
It wasn't this that really bothered me. What really took the cake was that this guy absolutely REFUSED to listen to any other ideas. He was adamant that his hook was the way it was going to be, that it was the best, that everything else was going to suck, etc. We had about $5000 of machine shop time donated to his screwy (haha) hook, which was a full 25% of the entire shop time we had. And we didn't even use the stupid thing.
Ugh I wanted to throttle him.
MrToast