Designing and Building a Rubber Band-Powered Car With Everyday Materials

For this project, I designed and built a rubber band - powered car entirely from everyday materials like cardboard, bottle caps, skewers, and straws. The goal was to explore how stored elastic energy can be converted into motion using simple mechanical principles with 3D printing or software required. I wanted to demonstrate that thoughtful design and prototyping can happen entirely by hand, relying on creativity, problem - solving, and basic physics. This car serves as a fun and educational example of how design thinking can bring even the simplest materials to life.

Cardboard - For the car’s body

4 Bottle caps - Wheels

2 Wooden skewers - Axles

2 Plastic straws - Axle holders

Rubber bands - Energy source

Paper clips - To attach rubber band to axle

Tape or glue - For assembly

Scissors / utility knife - To cut materials

Ruler + pencil - For measuring and marking

Cut a 15 cm x 6 cm rectangle from cardboard.

This will be the car’s body (base).

Cut 2 straws just a little shorter than the width of the base (~5.5 cm).

Tape or glue one straw near the front and the other near the back - these are axle holders.

Push a skewer or pencil through each straw - these are your axles.

Poke a small hole in the center of each bottle cap (use a pushpin or nail).

Push the ends of each axle into the caps. Use hot glue if needed to secure.

Make sure the wheels can spin freely and are aligned.

On the rear axle, attach one end of a rubber band:

1. Option 1: Tie it around the axle
2. Option 2: Hook it using a paper clip or tape loop

Stretch the other end of the rubber band forward and tape it to the front of the chassis or hook it on a skewer stuck through the front.

Attach a pencil to the floor using tape with the eraser part pointing in the direction you want the car to go.

Attach the rubber band to the eraser bit of the pencil.

Roll the rear wheels backward, this winds up the rubber band.

Place the car on a smooth surface and let go.

The rubber band will unwind and spin the axle forward, making the car drive forward.

This project challenged me to think about how to store and release energy mechanically, and how friction, alignment, and balance affect performance. I had to test and tweak my design, for example, changing the axle position to stop it from wobbling, and adjusting the tension of the rubber band. It was fun to create a working car from everyday materials, and it showed me how basic design principles apply in real - world builds.