How to Build a Rubber Band Powered Car

It always pays to give an outlet for your child's creativity. It is believed that a mechanic's child, if he has access to the workplace, has more chances of becoming a mechanic than other children. He sees his father handling different spanners and instruments while repairing a vehicle. In the workplace, the child gets to handle different instruments and unconsciously builds a perception that he can also follow in his father's footsteps and compete with his handiwork. The point is how your child is going to get this type of confidence. Why not team up with him and create something new. The sooner you start the faster will be his progress. How about a toy, a rubber band powered car?

You can build a rubber band propelled car using household items like rubber bands, corrugated cardboard, thumbtacks and an empty refill that you can take out from a ballpoint pen. Making this toy is a relatively small and achievable target. Moreover, even you will enjoy helping your child construct it and at the end, he will have a toy to boast about. This activity will help your child in learning how potential energy can be used. So, go ahead and follow the instructions on how to build a rubber band propelled car.

How to Make a Rubber Band Driven Car

Rubber Band Car with a Cardboard, Refills and Thumb Tacks

• Using empty refills from ballpoint pen to make the axles is a good idea. There are some of the brands with uses metal refills or find a sturdy one. Try refills from the gel pens. If they are not empty, blow the ink from them on a waste paper, and dispose it off carefully in the waste basket by rolling the paper into a ball without smearing the ink on fingers.
• Rinse the refills under a tap, to get the remaining ink out. You can further clean them by inserting a small gauze wire in it.
• The body of the car is to be made with a piece of corrugated cardboard of 1½ by 1 inch dimensions. This piece of cardboard, must have 1 inch corrugations running side by side across it. The corrugations need to be lined properly, as we are going to insert two axles (pieces of the refill) through two of them. This is necessary to allow the car to move in a straight line.
• At one end of the cardboard, cut a square hole of ½ inch by ¼ inch. It should be equidistant from the sides and ¼ inch away from the 1 inch side of the cardboard. Reinforce the hole by gluing the pieces of refill or cardboard of appropriate size around it. Let us call this hole, the 'back axle hole'.
• Out of a refill cut two pieces (axles), each 1¼ inch in length. These pieces will act as axles for the car. Make a small hole in the middle of one of the axles. Let us call this axle as 'back axle'.
• Force the back axle through the corrugation of the cardboard, across the back axle square hole, such that its middle part is visible through the hole.
• Take a rubber band and using a razor blade cut it at one point. Insert one of its ends through the hole in the middle of the back axle. Tie a knot at this end of rubber band, so that it does not slip back through when pulled.
• In the middle of the cardboard, make a small hole opposite to the back axle hole. Pass the free end of the rubber band through the hole and tie a knot in it. Alternatively, you can cut a small piece of refill and tie rubber band to it, to anchor this end of the rubber band. Glue the piece of refill to the underside of the cardboard.
• Force the remaining axle through the corrugation, 5 centimeters from the edge of the cardboard end that is opposite to the back end axle. Take care to align both axles.
• Wide thumbtacks are used as wheels, for the rubber band propelled car. Using rubber adhesive, glue the thumbtacks to the ends of both the axles.
• Allow some time for the glue to settle. Start winding the back wheels in clockwise motion, till you feel resistance building in them. This will wind the rubber band around the middle of the back axle. While winding the car, take care you don't rip the back axle out of the cardboard.
• Place the car on a plain surface and let it go. If necessary, make adjustments to it, so that it moves smoothly.

The potential energy stored in the stretched rubber band will propel the car as it unwinds.

Rubber Band Car Using CDs

Everyone loves cars that move fast. If you want to build a rubber band powered car that moves faster than the car explained above; read the following instructions on how to make it:

• To make this car, you will need two CDs, a sturdy metal wire, glue, two washers, a corrugated cardboard piece and obviously, a rubber band.
• For this car, you will need a 5 by 6 inch piece of corrugated cardboard. The cardboard is to be cut in such a way that the corrugation openings are visible along the length of the cardboard.
• In the center of the 5 inch side, cut a 2 by 1½ inch notch. The notch should be 1½ inch deep.
• A piece of straight, smooth wire of 6 inches in length will serve as an axle for this car. Drive the wire into the corrugation of the cardboard, across the notch at a distance of ½ inch from the edge of the arms of the notch. See to it that wire rotates freely to facilitate the movement of car. Ends of the wire that are sticking out, should be equidistant from the edge of the cardboard.
• Cut a ½ inch piece from the refill. Using a masking or duct tape, fix it perpendicular to the middle of the wire. This will serve as a 'catch' for the rubber band.
• Hold a ¼ inch washer against the opening in a CD and mount it on the axle. Use adhesive to glue the CD, washer and the axle together. Glue one end of the rubber band to the side opposite to the notch. Let the glue set in. Make sure the wheel and axle rotate together. Use the same procedure to mount remaining CD. This car has only two wheels.
• Hook the free end of the rubber band to the end of the 'catch' (piece of refill), and rotate the wheels in anticlockwise direction to wind the rubber band, till you feel the resistance in them.
• Place the car on a plain smooth surface and let it go. Measure the distance of how far it goes and if necessary, make adjustments to let it move smoothly.

A Rubber Band Car with a Sturdy Frame

• A car using a wooden board or a piece of plywood for its frame and that is powered by a rubber band can be made as a part of a science project.
• Fix 4 eye hooks at each corner of the car frame.
• For axles we can use 2 bicycle or motorcycle spokes. Insert them through the eye hooks and make sure that they can rotate freely.
• With the help of hole saw, make 4 wheels out of wood or you can saw a wooden rod with proper girth, to make them.
• Using drill machine, make a hole in the center of each wheel. Use proper sized bit for the drill so that the wheels can fit easily on the axles.
• Mount them on the axles, and glue each wheel to its axle end.
• Glue one end of a rubber band to the middle of the front axle.
• Glue free end of the rubber band to the middle of the frame of the car or you can use thumb tack or an eye hook to anchor it.
• Give some time for the glue to set.
• I am sure, you know what to do to make the car work. Enjoy!

This can be an ideal science fair project for your child. In everyday life, we see and use cars that are powered by gasoline. Though, a rubber band powered car cannot be put to use for practical purposes, it is fun making it. Following the instructions above, on how to build a rubber band powered car, serves as an opportunity to impart a valuable first-hand learning experience to your child!