How to Make a Solar-Powered Toy Car

A toy car can be solar powered.

A solar-powered model car can be built with materials readily available at any major hobby shop and is an excellent way to demonstrate the application of solar energy. The car is basically a piece of foam sitting on four wheels. On one side of one of the axles is a drive pulley. The drive pulley is connected by a rubber band to a motor shaft pulley on the motor, which rests on the top side of the foam. Above the motor, held at a 45-degree angle, are two solar cells connected to the motor by alligator clips.

Things You'll Need

• 2 solar cells
• 4 wheels
• 2 wooden model axles
• 4 small screw eyes (that fit the axles)
• Small drive pulley
• Self-adhesive motor clip
• Electric hobby motor
• Rubber band
• Motor shaft pulley
• Piece of foam board, 24 centimeters by 7 centimeters
• 2 lengths of clothes-hanger wire, 7 centimeters each
• Alligator clip test lead
• 4 lengths of clear vinyl tubing, 5 millimeters each
• Soldering iron

Instructions

1. Measure 2 centimeters up from the edge of both short sides of the 24-centimeters-by-7-centimeters piece of foam and make a mark. Cut across the foam at the marks so you end up with two 2-by-7 pieces and one 20-by-7 piece.

2. Glue the smaller pieces onto the ends of the longer piece of foam so that on each end there is 2-by-7 reinforced section.

3. Twist two eye hooks through each of the reinforced sections parallel to each other. The eyes should be parallel with the long edges of the foam. These will serve to hold the axles in place.

4. Slide the axles through the screw eyes.

5. Slide a vinyl spacer followed by the drive pulley and then a wheel onto the right side of the rear axle. Slide a spacer followed by a wheel onto the other three spots.

6. Roll the car forward to ensure that it rolls straight. If it does not, adjust the axles accordingly.

7. Slide the motor shaft pulley onto the motor shaft.

8. Place the rubber band over the drive pulley and then loop it over the drive shaft pulley. Position the motor over the foam so that the rubber band is held tightly between the two pulleys but is not stretched. Stick the motor down at this position.

9. Using copper wire, solder the two solar cells together in an array. Tape a piece of clothes-hanger wire across the cells to brace them as one unit. Place a piece of tape across the divide between the solar cells as well.

10. Cut the alligator clip test leads in half and strip about a centimeter from each of the wire ends.

11. Solder one alligator clip to the positive terminal of one of the solar cells. Solder the other clip to the negative terminal of the other solar cell.

12. Bend another piece of clothes hanger wire so that is is shaped like an elongated "Z" to act as a stand for the solar cells. Tape it to the bottom of one of the cells so that when the cells are set on the foam, the stand holds one side up over the motor like a lean-to. It should be angled at around 45 degrees. Tape down the edge of the other cell that is against the foam.

13. Attach the alligator clip from one of the cells' positive terminal to the positive terminal on the battery and attach the other clip to the negative terminal. Place the car in direct sunlight and it will be propelled forward by solar energy.

References

• Re-Energy: Build Your Own Solar Car
• Technology Student: Solar Powered Model Racing Car
• The Green Optimistic: How to Build a Solar Powered Car

Resources

• California Solar Center: Solar Cars