Model Trebuchet (2004)

• Our BIG Trebuchet!

	My trebuchet uses dowel as a hinge, and the counter weight is made from two old pots filled with sand. The lids of the pots are screwed to a short length of wood with two eyelets at the end. At one end of the arm are two more eyelets and to hinge the arm and counter weight I line the eyelets up and put a small length of metal rod through them. A minor problem with my counter weight is that wood isn't long enough, so it doesn't always hang vertically. However this doesn't seem to impair it in any way.
My first trebuchet used a shorter frame and a fixed counter weight, a box filled with marbles. It worked, but never as efficiently as I'd liked, after doing some more research across the internet I decided that this was probably because of two things; the weight was too light and the hinge for the arm was too low. If I was the raise the arm then it would be able to get a larger swing, which a heavier weight would also help with.
	I did this by gluing two lengths of wood to the side of the A frames. Unfortunately, I had to replace my plank of balsa wood with a bend piece of card because the new counter weight would hit the balsa on it's way around.