A friend of mine brought me a Catapult and asked me if i could replicate it. I took the design, and added a few modifications. For one, This one requires no fasteners. Its all snug-fitted together. We find these to be a ton of fun at the park (free ammunition comes from the trees.) We also like giving these as gifts for birthdays. If you want some of them, they are for sale. I have some at Cranberry Hill Mercantile in Sunnyvale, California, along with some of my other items.