How to Make a Catapult Out of Foam Boards
Since its invention in the Middle Ages, the catapult has been an item of interest to humans bent on projecting missiles. Catapults today are more likely to take the form of a handheld slingshot than a large piece of equipment designed to bring down a castle wall, but the concept of using tension and release to send projectiles through the air is the same. Make your own mini catapult with foam board, toothpicks and rubber bands, and send all of your loose change sailing through the room.
Instructions
- 1 Draw three 2-inch squares onto the foam board and cut them out with the utility knife. Draw one 1-inch-by-3-inch rectangle onto the foam board and cut it out.
2 Lay one square on the tabletop. Place another square perpendicular to the first, on top of one of the edges. Use a pencil to make an X underneath this upright square, about 1/4 inch from the edge of the square on the table. Get the X as close to the middle of the foam board's thickness as you can. Repeat this on the other end. You should now have an X 1/4 inch away from either end of the bottom square, precisely under the center of the perpendicular foam board square.
3 Make two more X marks on the bottom square, on the side parallel to the side where you placed the upright square. Use the third square as a guide. You should now have four X marks on the bottom square.
4 Break two toothpicks in half. Flip the square over so that the X marks retain their left-right orientation but are now on the bottom of the flat square. Hold one of the squares perpendicular to the bottom square on the side where there are no X marks and stick a straight pin through the X and into the perpendicular foam square. Remove the pin and stick half of a toothpick, pointy end first, through the hole to secure the squares to each other. Repeat this with the other X. You should now have one flat square with a perpendicular square along one of its edges. Repeat this with the third foam square to complete your catapult base.
5 Make an X mark 1/4 inch down from the top edge at the center of both side pieces of your base. Make an X mark on both foam sides of your long rectangular foam piece 2 inches from one end and 1 inch from the other end. The X marks should line up exactly. On the end where you have left an inch, make another X 1/4 inch away from the edge and 3/4 inch away from the first X. Do this on both sides so they line up exactly.
6 Tie two mini rubber bands together. Stick the pin through the X marks on the long rectangle, then widen the hole with a toothpick. Use a toothpick to feed one end of the rubber band chain through the rectangle. Pull the rubber bands through until there are equal amounts of rubber band showing on both sides of the rectangle.
7 Stick the straight pin through each side X in turn, then through the other X marks on the long rectangle. Run a toothpick through one side X, through the long rectangle and through the other side X to secure your catapult arm. Wiggle the toothpick around to widen this hole, as you will want the arm to be able to swing freely.
8 Make an X on each side of the base, just above the foam board (about 1/4 inch) and 1/2 inch away from the edge on the side of the base where the rubber bands are hanging from the catapult arm. Stick a pin through both X marks in turn, then feed a toothpick through 1 X, both rubber bands and through the other side of the base.
9 Gouge out a circle on the free end of the catapult arm into which to place your projectiles. Test it with light objects first so as not to cause accidental damage to your home.
