I had made a few after getting into it from Boy Scouts, and when my time came to engage in the yearly tradition of high school physics kids launching rockets in the football field, instead of making a new one, I just brought my Big Bertha from home. I hadn't launched it yet. It used one massive "E" engine. First launch, dwarfing the launchpad, it exploded. AFAIK its battered fuselage was hung in the physics room until the teacher retired. Good times.