Rubber Band Car

Rubber band cars teach the basic concepts of Physics to kids by way of constructing a fun toy car. Moreover, they get to know the tricks of automobile functioning and design through this activity. The requirement of simple tools enables its construction at home.

How to Make a Rubber Band Powered Car

Here, we will be walking you through the steps of making an easy rubber band propelled car that runs on 2 wheels.

Hypothesis

A rubber band car accelerates in the forward direction on releasing its rubber band component.

Supplies

• A 5½” square sheet of corrugated cardboard
• Styrofoam
• Rubber band
• Thin wooden skewer
• Tape
• Scissors
• Ruler
• 2 CDs

Project Instructions

1. Turn the cardboard and hold it so that the corrugations align themselves horizontally (and not vertically).
2. Cut a notch 2” x 1½” at the middle of an end.
1. Insert the skewer into a groove near the outer edge of the cardboard passing it through the notch and coming out through the other side forming the axle. Ensure that equal lengths of the skewer emerge out of the sides.
1. Make a catch for the rubber band by wrapping a small piece of tape around the center of the axle.
1. Plug a tiny Styrofoam piece into each hole of the 2 CDs and attach them to the axle.

[N.B. Once the wheels are fixed, give them 1-2 rotations to ensure a smooth movement. If the wheels and axle do not rotate together, consider stronger attachment with a bigger piece of Styrofoam. If there is a lack of free rotation of the wheels, then reposition to allow a larger distance between them and the cardboard chassis.]

1. Tape the rubber band to the end of the chassis opposite to the notch.
1. Loop the free end of the rubber band around the catch and wrap it around the axle as shown below.

[N.B. For a fast car that goes a long distance, rotate the axle a few times to increase the winds of the rubber band.]

1. Hold the axle so that the rubber band doesn’t slip and place the car on the floor.
2. Let go of the rubber band and watch your car zoom forward.

How to Build a Rubber Band Car: Video

Toothpicks, straws and bottle caps constitute this unique design of rubber band race car.

How does it work?

On twisting the rubber band around the axle, you are storing potential energy in it that gets transformed into kinetic energy when you let it go. The rubber band unwinds to regain its former configuration spinning the axle and propelling the car forward in the process. Hence, the more the winds of the rubber band, the faster and longer your drive. It works on the principle of conservation of energy that energy can neither be created nor destroyed, or the total energy in an isolated system remains constant.

Other Designs of Rubber Band Cars

Instead of cardboard, the cars can use a variety of lightweight materials for the chassis such as Lego, balsa wood, light plastic container, cereal box or foam board. Plastic bottle caps, toy wheels like those of K’NEX, film canister caps can also serve as the wheels. Wooden dowels threaded through straws work well as the axle. Listed below are a range of design ideas that you can choose from.

It would be a good idea to draw a blueprint of the desired plan on paper before starting off if children are doing it in the school lab or performing at a science fair.

Plans to Try Out

Decide on the best car design by checking the following.

• Do certain types of wheels offer less friction and speed up the car while others don’t?
• What happens when smaller wheels are used in front and bigger ones at the back and vice versa? Does it become faster or slower?
• Does the weight of the car affect its speed? You can check this by placing coins or washers on it.
• What happens if the chassis is longer in size?
• If you start it on a ramp, does it travel longer?
• Which one is faster among 2, 3, and 4 wheeled designs?

The amazing car project is going to get the kids hooked on to their models for hours. Though it might need a bit of trial and error at first, once they are comfortable with the steps they can design a good car pretty quickly. Organizing competitions can help sharpen their car building skills.