Now let's assemble the swing arm of this catapult and install it. We are almost done here.

Take your 28 inch long piece and drill a hole in one end so your broomstick or pipe slides easily through it. It should be a loose fit so the swing arm will pivot freely.

Make a small cardboard cup and staple it down to the other end. This the the cup that holds the projectile. You don't have to make a cup you could cut down a plastic cup so it is about 2 inches deep and staple that down.

Now put your other eye hook onto the swing arm. Make sure it is nice and tight.

Lets finish this up! Slide the broomstick through one end of the catapult, through the swing arm then through the other end of the catapult. Put a couple of screws in it to hold it firmly in place. Then attach the bungee cord and you are ready to go!

I hope you had fun making this catapult and please be safe! USe safety goggles and never aim it anyone or anything. Remember to be conscious of the bungee cord and hooks. excessive pressure could cause them to snap. So be careful.

Tips on making your Catapult more powerful.

The Bungee Cord is the most important thing so using different cords will change the strengthh or adding a second cord.

The crossbar is very important in that it sets the angle that your catapult fires off. You can adjust the angle of fire by lowering or raising the crossbar on the uprights. Or you can use thinner or thicker wood for the crossbar.

The length of the swing arm also has an effect on how powerful the catapult is. Generally the longer the swing arm the more power you will get so try using a piece of wood that is longer than 28 inches. When you do this you will probably have to tinker with the location of the crossbar to get things just right. The important thing here is to experiment and see what works best for your Ogre.

The pivot point (The hole in the swing arm that the broomstick goes through) is an important energy point. If it is too tight, or too loose it will absorb energy and decrease the efficiency of your catapult. Make sure it swings smoothly. And if you wanted to get real fancy you could use some kind of a bearing. I have made catapults using the axle of a bicycle for this pivot point. It really works well.