• 1

    Here are some of the materials you can use

    • 2 compact discs (CDs)
    • 2 pieces of Styrofoam, about 2 in. (5 cm) long; thick enough to fit tightly in the CD hole 
    • rubber band
    • ruler
    • scissors
    • 1 sheet corrugated cardboard (about 5½ in. [14 cm] square) (corrugated cardboard has grooves in the middle, like a cardboard shipping box)
    • tape 
    • 1 wooden skewer (thin)
    • TIP: If you don’t have any Styrofoam, then get creative and use other things around the house to hold the wheels in place—poster putty, old marshmallows, pieces of dry sponge, packing material, gummy candy etc. Try them all and see what makes your wheels work best!
  • 2

    Prepare ahead of time

    • Have paper and a pencil ready to jot down ideas and sketches as you design.
    • Look at or think about cars and other wheeled vehicles.
  • 3

    Think about the challenge

    • What are some of the parts of a real car? (Axle, body, power source, wheels)
    • What parts of the rubber band car are the same as on a real car?
    • How does a car move?
  • 4

    Think about and write down a few ideas

    • List different parts you will include in your rubber band car. 
    • List different ways to power source your car.
    • How might you get the wheels to rotate at the same time?
    • TIP: A rod passing through the center of a set of wheels and securely attached to each wheel is called an axle. An axle makes the wheels rotate together. 
    • TIP: Inventors’ and engineers’ initial ideas rarely solve a problem. Instead, they try different ideas, learn from mistakes, and try again. This is part of the design process.
  • 5

    Look at the materials

    • What material can you use for the body of the car? The axle? The wheels?
    • What can you use to power the car? 
    • What materials do you have to attach the wheels to the axle?
    • What materials do you have to attach the power source to the car?
  • 6

    Design and build the body

    • Decide how big the body of your car will be. Cut it to that size. 
    • Cut a notch in the center of one end of the body. 
    • TIP: Be sure the corrugations—the groves in the cardboard—run from the right to the left (not back and forth). This will allow you to easily thread the axle through the body.
    • TIP: Measure twice, cut once! After you measure the notch, measure again before cutting.
  • 7

    Make the axle

    • Slide the axle through a groove that’s close to the edge of the cardboard. 
    • Make the ends equal on both sides of the cardboard.
    • TIP: If you can’t slide the skewer through the cardboard, check that your cardboard was positioned correctly so the skewer slides right through the groove (corrugation) in the cardboard.
  • 8

    Modify the axle

    • Wrap a small piece of tape around the middle of the axle to make a “catch” for the rubber band. 
    • TIP: The “catch” is used to hold the rubber band in place as you wind it around the axle. Be sure it sticks out enough so the rubber band doesn’t slip over the top. 
  • 9

    Assemble the wheels

    • Work a piece of Styrofoam into the hole of each CD and attach the axle.  
    • Rotate the wheels to be sure they are firmly attached to the axle.
    • TIP: If the wheels and axle are not rotating together, you may need a larger piece of Styrofoam to be sure the CD, Styrofoam, and axle are tightly joined together.
    • TIP: If your wheels don’t move freely, try repositioning them so there is lots of room between the wheels and the cardboard.
  • 10

    Attach power source

    • Chose the rubber band you want to power your car.
    • Decide how you will attach the rubber band.
    • Attach it to the car (opposite the notch).
    • TIP: Different lengths and widths of rubber bands will wind around the axle differently, store different amounts of energy, and release their energy differently. 
  • 11

    Power your car

    • Loop the loose end of the rubber band over the catch.
    • Wind the rubber band around the axle.
    • TIP: When you turn the axle on the car, you are giving the rubber band potential energy—which is stored energy. When the rubber band unwinds and the axle spins, it transforms the potential (stored) energy into kinetic energy—or motion energy.
    • TIP: The more you wind the rubber band around the axle, the more energy can go to your car’s wheels—and the faster and farther it will go.
  • 12

    Ready, set, go

    • Hold onto the axle and place your car on the floor. 
    • Stand back and let it go!
    • TIP: If your axle doesn’t spin easily, check that the catch isn’t hitting the cardboard when the axle spins.
    • TIP: If your wheels are wobbling, check that the Styrofoam is firmly holding the wheels and axle together.
    • TIP: You’ve just built a prototype, which is an early version of a product. Prototypes help engineers understand a product’s strengths and weaknesses and how the product might be improved. 
  • 13

    Did you know?

    • The Rubber Band Road to Early Flight
      It was a simple, rubber band-powered toy that became the inspiration for Orville and Wilbur Wright’s interest in flying. In 1878, Milton Wright, the boys’ father, brought home a rubber band-powered helicopter. Orville and Wilbur expected the helicopter to fall right to the ground, but instead it flew across the room! Although the toy broke, the boys never forgot the helicopter—or their excitement over watching the helicopter fly through the air. And, luckily for all of us, they remembered that excitement when they grew up and became interesting in flying machines!
  • 14

    Try this next! 

    • Make a car that will drive through sand. Modify the car so it can work on sand or grass or zip through a thick carpet.
    • Adapt your car to carry a tennis ball.  Change your car so it can carry a tennis ball.