In this instructable, I'll show you how to make your very own Trebuchet. Mind you, this is technically NOT a trebuchet because it uses a rubberband to fire, but it can be adapted for weight. I attempted to use weight on mine, but found that the spring worked much more impressively then the weights did.
Materials you'll need for this...
1: Wood: 19 inch 1X4" plank for support arms, 13 by 9 inch 1X9" thick plank for the base, roughly 22 inch 1X4" plank for the firing arm
2: PVC pipe, 3/4" type, roughly 9.5" long.
3: Screws: standard wood
4: Superglue (optional)
5: Steel chicken wire, or make your own basket out of string
6: String/parachute cord (string recommended)
7: Weight (optional)
8: Spring: rubber band (optional)
9: Some kind of saw to cut the wood with.
10: Pipe cutter.
11: Steel pipe in place of PVC if you have it lying around.
12: Drill or screwdriver (drill recommended)
13: Wood drilling bits the same diameter as the pipe
14: Wood Peg (optional. I'll explain this one later)
15: Zip-ties (recommended for smaller tasks)
If built correctly/tuned correctly, the little trebuchet (or microtreb as it's known in my trade) can fling projectiles over dizzying distances with the slightest pull. My own version can throw a golf-ball about 18 feet on average, but with a little extra "oomph", we've gotten it to fire up to 22.5 feet in a single throw.
*DISCLAIMER*: use at your own risk. We are not responsible for injuries during construction or during play with catapult. Not recommended for children under 10.
Step 1: Base Construction
The first step is to simply build the base. Cut out a 9X13 inch base, or longer (15-17 inches recommended if you can spare the wood) for more stability. Once the base is cut, I recommend marking it so you won't confuse it for anything else you have lying around.
The base is a very crucial part, considering it has to support whatever you're flinging. I recommend plywood rather then particle board (PB may snap due to the load stress of your projectile.)