Rolling Catapult Van

I made a compound machine "Rolling Catapult Van". It is made out of random things that I found in my house, so reused items. My project is an example of a lever and wheels and axle.

• Four 7 ½ x 4 ½ cardboard pieces
• Two 4 ½ x 4 ½ cardboard pieces
• Four medium sized lego wheels
• Two sticks/rods/axles (I used lego sticks)
• Two circular hollow pieces( EX. piece of a straw)
• Several large popsicle sticks
• Several small popsicle sticks
• A cap or small cup
• Hot glue gun & hot glue
• Duct tape
• Something to draw with
• Small empty box (EX. necklace box)
• Small polybands & big rubber bands
• Large scissors or exacto knife (scissors worked better for me)
• Ruler or tape measurer

To make your wheels and axles you are going to want to put 1 rubber band tightly around the stick/axle, then slide your hollow circular piece on, then the other rubber band. (make sure you leave enough room for the circular hollow pieces to spin) You should have a symmetrical rod now. Then slide 1 wheel on each side. Repeat this step for the other wheels and axle too.

Get a large popsicle stick and duct tape it to one side of the circular hollow pieces that are on your axle, then duct tape it to the other axle the same way. Doing this, you're allowing the wheels and axles to spin while connecting your frame. Make sure that none of the tape is on the axle itself, just the hollow circular piece.

Since the popsicle sticks are shorter than the wheels, you’re going to want to glue or tape a few more popsicle sticks onto the initial one for height. (don’t worry if it wobbles, it’s most likely just the hollow circular pieces wiggling, not a big deal) Then glue your small necklace box to the top of the popsicle sticks, this will give it even more height and stability.

Take your cardboard pieces and arrange them into whatever you want the body to be, this step was kind of an experiment for me so it ended up being a van. I cut out windows, you don’t have to but I figured a van or a car might be more interesting than a box on wheels. Hot glue your body together, then glue it to the necklace box on top of the wheels and axles, then I added popsicle sticks to the front to make it more stable.

To make your catapult, you're going to want to stack 12 large popsicle sticks and put a rubber band on each side to hold them together, then in between the 3rd and 4th popsicle sticks (on the bottom) put a popsicle stick there. Then, put another popsicle stick on top of the 12th one to make a floppy one, connect them with duct tape. Get a cap or small cup and tape it to the top of the one you just added.

Glue the bottom of your catapult to the top of the van, make sure you put the side with the cup on the back.

This is my finished product! (ignore my little brother in the video)