Building a mini electric car is an exciting science project that teaches students about mechanical engineering. In fact, it's often used as a competition in middle school or junior high. Students doing this project learn how to create a simple method of propulsion by converting battery power to mechanical energy. They also explore design concepts and basic gluing techniques.
Fasten the wooden blocks to the plastic base with the screw eyes; the screws should enter from the bottom of the base, fastening the blocks on top of the base. Two screw eyes should fasten each block, parallel to each other and placed 1/2 inch from each side of the plastic base.
Fit each axle through the screw eyes on the underside of the plastic base. Place a piece of the plastic tubing on the left and right side of each axle, flush with the screw eyes. Attach the wheels to the axles.
Poke the brass fasteners through the top of the plastic base and fasten; they should be close enough together so that the paper clip will fit over both. Hook one end of the paper clip over one of the fasteners to form the circuit switch.
Place the battery holder on the plastic base, lengthwise against the wooden block. Glue the battery holder to the block.
Strip a 3/8-inch section of plastic from the ends of each piece of wire. Connect one end of a red wire to the battery holder's positive end; connect the other end of this wire to the nearest brass fastener. Connect the other red wire to the other brass fastener and leave one end free. Connect the black wire to the battery holder's negative end, leaving its other end free.
Glue the motor mount onto the plastic base, lengthwise against the battery holder. Make sure it's at the edge of the base. Attach the motor pulley to the motor and position the motor into the motor clip. Place one end of the rubber band around the motor pulley; place the other end of the rubber band around the far axle, on the same side. The rubber band should be tight.
Connect the free red and black wires to the appropriate terminals on the motor. Close the paper clip switch; this should complete the electric circuit and cause the car to move.
Mini electric car kits that contain all the required materials are available online or at hobby shops. Alternatively, you can buy the individual parts and cut them to size. Use double-sided tape instead of glue if you don't have time to wait for glue to dry.
Tips and warnings
- Mini electric car kits that contain all the required materials are available online or at hobby shops. Alternatively, you can buy the individual parts and cut them to size.
- Use double-sided tape instead of glue if you don't have time to wait for glue to dry.
Things you need
- Corrugated plastic base, 2 3/4-by-4 3/4 inches
- 2 wood blocks, 1/2-by-1/2-by-2 3/4 inches
- 2 model car axles, 4 inches
- 4 screw eyes
- 4 lengths of plastic tubing, 1/2 inch
- 4 model car wheels to fit axles
- 2 brass fasteners
- Paper clip
- Battery holder
- 2 lengths of red wire
- 1 length of black wire
- Electric motor
- Motor mount
- Motor pulley
- Small rubber band