Activity Title: Build A Wind Turbine
What Do I Need?
- Small hobby motor, 6-12 volts
- Red, high-intensity LED
- Four craft sticks
- Small paper cup for fan blades
- Medium cup for base
- Hot-glue gun and glue
- Drill bit that matches the size of the motor shaft (we use AWG#50)
- Fan or windy day
How Do I Do It?
- Cut the sides of the small cup into four equal parts. Remove the base to create four curved pieces that will be the blades of the wind generator.
- Use hot glue to attach two craft sticks together at the center so they make a plus sign.
- Once the glue is dry, drill a small hole the size of the motor shaft in the center of the craft sticks. This will serve as the frame for your blades
- Glue a blade to each of the craft stick ends, as shown (click to enlarge image). The blade design has the greatest impact on the efficiency of the wind generator; this is just one way to do it. Feel free to try materials other than a cup to construct something you think will best utilize the wind to yield the most rotations per second.
- The hobby motor should have two small prongs sticking out of the back that serve as the terminals where you would normally attach a power source. Instead, attach an LED to the back of your motor by twisting each leg of the LED through a different terminal on the back of the motor. The correct orientation of the LED will depend on whether the blades spin clockwise or counterclockwise, so you will know if you need to switch it once you test the windmill. Slide your blade frame onto the shaft of the motor.
- Glue one end of each of the other two craft sticks on either side of the larger cup to make a stand that holds the motor above the cup like chopsticks. Glue the other ends of the craft sticks directly to opposite sides of the motor to hold it in place. Make sure the motor is positioned so that the stand does not obstruct the ability of the blades to turn freely.
What's the Science Behind It?
A generator is a device that converts mechanical energy into electrical energy. This is the opposite of how a motor works, which uses electricity to create motion. This activity uses a hobby motor in reverse to create an electric current. By attaching blades to the motor, wind can be used to provide mechanical energy to the motor so that it works like a generator and supplies electricity. This electrical output could be measured with a multimeter, but an LED provides an easy readout that shows power is being generated. This simple wind generator is a model for wind turbines used to generate electricity around the world. Though they operate on a larger scale, they use the same physical principles to convert wind energy to electricity