In this Instructable I will show you how to build a neat little catapult. It requires only a few materials and about an hour of your time. This can be made out of foam board, balsa wood, or various other sturdy, but light materials. And it shoots pretty far for a catapult of its size. I got mine to shoot a plastic airsoft BB 27 feet with only 2 rubber bands.
Step 1: Materials and Tools
In order to make this project you need a few household things, such as:
-Utility or X-acto knive
-Dremel rotary tool (if you are using balsa wood)
-Foam board or balsa wood
-Toothpicks (about 5)
-Super small rubber bands (I used braces rubber bands)
-Super Glue (only if you are using balsa wood)
-Printed out template
Step 2: Cutting the Pieces
After gathering the materials and tools needed, you can cut out the templates for the pieces. Trace the borders of templates on the foam board or balsa. Using a utility/ X-acto knife cut all the pieces out of the foam board. To make it easier I like to put a piece of carpet under the foam board while I am cutting.
Step 3: Constructing the Frame
First, where ever there is an X on the templates, using the straight pin poke a hole all the way through the foam board. These small holes will allow the toothpicks to go in easier. Next, cut or break two toothpicks in half. Then, while holding the pieces of the frame together stick the piece of toothpick up through the base and into the side. After the bottom of the toothpick is flush with the base, the point of the toothpick should be sticking up through the side. You can trim this off. You might be thinking why am I using toothpicks and not using some sort of adhesives. Super Glue dissolves foam and hot glue will melt it. I didn't have any other glues, but if you have others that work, you can also use them.
Step 4: The Arm
First, using the template of the arm, trace the circle onto the square. Using the utility knife cut along the circle about an eighth of an inch deep. Next, gouge out the circle. There are a couple of pictures that will show you what I mean. Then, using a toothpick make the pivot hole and rubber band hole. You can see were these are placed in the pictures. These holes need to be slightly bigger than the toothpicks in order for the arm to swing freely. You also need to make a hole with the toothpick for the rubber bands to pass through. Next you need to thread the two connected rubber bands through the bottom hole. Now that you are done the arm, you can get one of the uncut toothpicks. Stick it through the first side, the pivot hole in the arm, and finally through the other side. Next, get another toothpick an stick it through the first side only. Then thread the toothpick through the first rubber band loop, and then the second rubber band loop. When both rubber band loops are hooked on the toothpick you can then stick it through the other side. The rubber bands will probably be twisted so you can straighten and make sure they are centered.
Step 5: Finished!
Finally your mini catapult is complete. Now you can find some ammo such as BB's, clay, or small rocks. Also you can experiment how different rubber band combination affect the distance that the projectiles are launched. Have fun with your new catapult and thanks for reading my Instructable!