Build a Cardboard Car, Tractor, Rover, or Whatever

This is a fun and simple vehicle build that uses a tt geared motor, AAA battery pack, cardboard and a few other simple materials. It has unlimited variations and possibilities and I often use this activity with groups and adapt it to whatever theme seems appropriate. It has been a Mars rover, a tractor, a stock car, a wacky racer, and a robot. The materials are simple, inexpensive or free.

This is the suggested material list for a basic vehicle. However the point of building this vehicle is to have fun and be creative. Be sure to have lots of craft materials on hand for decoration and extra cardboard for modifications. The sizes listed below are generalizations and can be tweaked if you want to modify or adapt the vehicle.

Materials

1. tt gearbox motor w/ leads- these can readily be found online
2. AAA battery pack with a switch and jst adapter plug (either 2 or 3 battery versions work well)
3. 2 Paper straws, ~2”
4. Plastic straw ~3”
5. Cardboard piece, ~ 3”x 6”
6. (4) Cardboard squares, ~ 2"-4”
7. 3/16” wooden dowel ~4"-5"
8. Craft supplies for decoration

Tools

1. Scissors
2. Glue gun or tape

Attach the battery pack, switch side facing up, to one side of the rectangular cardboard piece using your choice of adhesive. I like glue guns because its quick and durable. Make sure the wires hang off the cardboard behind the pack. Place the motor on the opposite side of the cardboard. When you are done, you should have your battery pack on the top and the motor on the bottom of the cardboard. You may need to bundle the wires together to get them out of the way.

Attach the two short (2") pieces of paper straw to the white axle hubs on the motor, making sure that they extend past the edge of the cardboard. Be careful that you don't get glue between the axle and motor body or they may get stuck. Optionally, you may want to glue a short piece of 3/16" dowel inside the paper straw for extra strength.

Cut four wheels from the cardboard squares. Consider what shapes you might want. Do the wheels even need to be round? Are you going for speed, traction or some other fun movement? Then poke holes in the center of each wheel.

Attach the plastic straw (3") to the underside of the cardboard on the front end of your vehicle. Slide the wooden dowel (5") through it and push the wheels onto each side of the wooden dowel. Secure the wheels with glue.

Push the remaining two wheels onto each straw of the the motor assembly and secure with glue. Your car should now be finished!

It is now time for you to test your vehicle. Switch on the motor and watch as it drives away.

If the motor is not spinning in the correct direction, or you would like to change its direction, switch the red and black wires where they connect to the battery pack. This will reverse the direction the motor spins.

Think about what you want your vehicle to do. Do you want it to be as fast as possible, or traverse difficult terrain, maybe it could pull something? Think about what the vehicle needs for different kinds of performance and adapt it to achieve your goal.

Consider the following when trying to improve your vehicle’s performance...

1. What size and shape are the wheels? Do they even need to be round?
2. How heavy is the vehicle?
3. How far apart are the wheels?
4. Does moving the motor/battery pack position affect the vehicle?
5. What about looks and decoration?

Add or take away different materials to help improve the vehicle and personalize it with decorations and give it a fun name!