This is an really cool catapult! it shoots pretty far and its really simple! This is my original idea. Hope you like it!! :):):):)
Step 1: The Pieces You Will Need.
Step 2: Building the Base. and Adding Red Support Beams.
Step 3: Put on the Two Red Parts As Seen in the Picture.
Step 4: Then You Will Put on the Yellow Supports.
Step 5: Now You Will Put a Red Rod Though the Holes.
Step 6: Put on the White Pieces, Like in the Picture.
Step 7: Put on the Piece Like in the Picture Below. (i Don't Know What the Name of It Is)
Step 8: Adding More Spacers.
Step 9: Make Top and Bottom Arm for It.
Step 10: Hanging the Bottom Arm.
Step 11: Put Top Arm On.
Step 12: Now You Will on On the Rubber Band.
make sure your do now have a thin one or it will not shoot right, you would want a medium thickness one like in the picture
Step 13: Hooking the Rubber Band Over the Arm.
Step 14: And Your Done!
You can adjust the orange pieces on the top arm to the size of your object your launching. Have fun be safe and its not my fault if you shoot your eye out or kill somebody! :):)