I have been reading & building stuff off instructables for a while now. I thought it was time to contribute.
Here is my first instructable: a simple but effective catapult. it fires about 2 feet, but shoots it really high.
it uses marbles, but small sinkers work as well.
Ready to build: continue to step 1.
Step 1: Parts
Below is a list of parts. Gather them now.
Step 2: Frame
Build two of the below pictures.
Then, join them together. see last pic.
Step 3: Tensioning Mechanism.
This is a little hard to explain, but here goes.
First, set it up as shown in the first two pictures.
Then, wind a turn on until you see picture 3.
Step 4: Ammo Arm.
I don't know what to call it, but you've got to build the arm that holds ammo and fires it.
If you know what it's called, comment & tell me.
Step 5: Stabilisers.
Join the catapult ammo arm as shown in pic one.
Then, Add stabilizing rods.
Step 6: Done!
Please comment highly, and nicely, on this.
Enjoy the catapult and win your office territory back.