This is my entry for the pocket size contest. This neat little catapult will launch mints or other fun projectiles in a medieval and discrete manner. It only takes about 10 minutes to build, and is really fun. Enjoy.

Step 1: Materials and Tools

All the materials and tools you need for this project can be found around your home.

Materials:

Tin (I used an Altoids Gum tin because it was small and compact)
Coat hanger
Rubber bands
Electrical tape (any tape will do)
Small piece of cardboard
Measuring spoon (or something similar)
Paint (optional)

Tools

Wire cutters
Hot Glue
Scissors
Pliers

Step 2: Freshen Your Breath...

Get you tin ready, whether that means eating the mints/gum, or giving it a good cleaning as you will be adding glue soon.

Step 3: Making the Tension Arm....

Cut a piece of wire hanger to your desired length. This will vary depending on the size of the tin.

You are going to bend the wire to fit as flush as possible in the tin, and have two notches on each side to hold the rubber band in place (see picture)

I used a pair of pliers and a small vice to get this step done. You may need to try a couple of times to get it just right.

Step 4: Cutting Spoons?

Take your measuring spoon and cut the handle to the desired length. I found plastic spoons to be the best option as they are quite light. You'll want the spoon to be approximately 80% the length of the tin to allow for movement.

Step 5: Holding the Arm in Place...

In this step we are going to make an insert that will fit over the spoon and in between the rubber band. This will allow for adjustments to the length of the catapult as well as aid in winding the rubber band.

To do this, cut a small piece of cardboard and wrap it around the base of the spoon. While still on the spoon, wrap a couple turns of tape for added strength.

IMPORTANT: Do not tape the cardboard to the spoon; you want to be able to remove the spoon. You want it to be snug but allow for movement.

Step 6: Getting Ready to Fire...

Remove the cardboard spoon holder from the spoon. Place a rubber band across the tin on the two notches made with the coat hanger.

Insert the holder between the rubber band and start turning. Make sure you turn in the right direction or the catapult wont fire.

Step 7: Bombs Away....

Insert the spoon into the holder and voila, you are finished. Load up the catapult and fire away.

It may take several tries to get your desired settings. Your shots will depend on three things. 1) the size and weight of your ammo 2) the tension in the rubber band and 3) the length of the catapult's arm.

I got some pretty good distance after playing with it for a while, and it is good fun.

I also made some small targets that fit inside the lid for when I can't find anyone to shoot mints at.

Have fun, and please make or suggest improvements and post your pics. Be careful not to hurt anyone or give them fresh breath.