How to Make a Rubber Band Powered Car

Learn to build a simple rubber band car with your kids using everyday materials for hours of STEM fun.

1. Gather Your Materials. You'll need a small cardboard box (like a tissue box or cereal box), four bottle caps or small wheels, two wooden skewers or pencils, several rubber bands, tape, scissors, and a small weight like a coin. The box will be your car's body, the skewers will be axles, and the bottle caps will serve as wheels.
2. Prepare the Car Body. If using a tissue box, tape the opening shut. For other boxes, make sure they're sealed. Poke holes through opposite sides of the box, about an inch from each end. The holes should be just big enough for your skewers to slide through smoothly. Make sure the holes on each side line up so your axles will be straight.
3. Create the Axles and Wheels. Push the wooden skewers through the holes to create your front and rear axles. Attach bottle caps to each end of the skewers with tape, making sure they're secure but can still spin freely. If the caps are loose, wrap a bit of tape around the skewer first, then attach the cap.
4. Add the Rubber Band Motor. Tie one end of a long rubber band to the front axle. Thread the other end through the car body and out the back. Attach a small weight (like a coin) to the free end of the rubber band using tape. This weight will help the rubber band unwind smoothly and provide momentum.
5. Wind Up and Test Your Car. Hold the car steady and turn the rear wheels backward several times. This will wind up the rubber band and store energy. Place the car on a smooth, flat surface and let it go. The rubber band will unwind, spinning the axle and propelling the car forward. If it doesn't work well at first, check that your axles spin freely and adjust the rubber band tension.