Taking Apart an Electric Pencil Sharpener

Today, our group decided to dismantle an electric pencil sharpener to try to learn about its motor. The act of taking it apart proved not to be very challenging, however, it was putting it back together that was extremely frustrating. This was not because we couldn’t remember which piece went where, but because of the way the wires from the motor connected to the wires from the wall plug. We could not seem to get it right while the other group with an electric pencil sharpener could. I do not think that these pieces of equipment have potential for our generator because it requires too much electricity for it to work. A motor from a hairdryer, however, would work much better because it can be spun by air (or with adaptations, water). Moving forward, it is expected that our group will choose a motor from another hair dryer for our future project.

unnamed unnamed2 unnamed3 unnamed4

Explanatory Blog Post of Project

Only a few days ago our group of Sam, Ollie, Lucas, Andrew and Delia selected the ‘Wind Power 2.0′ electricity generating turbine kit to build. Since then we have struggled together with reading the directions, trouble shooting, and worked together as a team to build this complicated miniature wind turbine. From building this kit, we have learned about gears and gear ratios through hands on experience.

unnamed (5)

The group from left to right: Delia, Andrew, Lucas, Sam, Ollie

Our wind turbine was able to generate power through gears. Gears work in a ripple effect- each gear will help to rotate another gear and ultimately generate power. Gear ratios can be figured out through simple mathematical equations such as division. The size of the gear can be measured by its number of teeth. For example, if you have a red gear with 12 teeth driving a yellow gear with 24 teeth, then for every two red rotations you have one yellow rotation because 24 divided by 12 is two. The red gear therefore is moving twice as fast as the yellow one. This is what people mean when they say “gear ratios.”


In our windmill, we had three different gear ratios. We had to adjust them ourselves. The first combination (red to yellow) is the least resistance, the middle combination (blue to blue) is slight resistance, and the third combination (yellow to red) is the most resistance.

The spinning gears connect to the generator of the windmill, which contains even more gears! The gears help a battery and copper coils spin inside of the small metal cylinder inside of the generator. This is where the electricity is made. The electricity is then powered through the wires in order to light up the LED light. The light is only lit up when the gears are spinning, the generator does not store energy it only outputs it.

gears 2

This photo shows a lot! From the gears, you can see that there is a black axel that spins the gears inside of the generator. The power created in the generator is wired up to the LED light on the right hand side.

gears 3

A close up of the generator. The metal-looking disc is where the electricity is generated to be passed through the red and black wires up to the LED light, also on the right hand side.

The most challenging part of building this wind turbine was figuring out the gears and the best gear ratios. This was hard because we had to be able to decide which combination of gears would work the best at each time. It was also challenging because the wind mill did not want to spin very fast, even when it had two fans blowing lots of air on it. However, it was a good model to learn more about the wind turbines in real life, because when we would spin the blades by hand the LED light would light up.

unnamed (7)

Lucas was very good at angling the wind mill and the fans for maximum rotations

unnamed (6)

Fellow classmate John comes to take a look at our finished product while we fiddle with the LED light

This project was very engaging for all of us, but it also really allowed the different group members to display their talents. Sam was very good at interpreting directions and explaining them. Ollie was the chief engineer. Andrew helped to screw together the different pieces which was quite the task without a screw driver! Lucas and Delia were the overseers of the project. We kept the many pieces and parts organized which was especially important during clean up. Overall, this was a really enjoyable project for everyone and it brought us a lot closer as a team because we were all trying to figure this out together. Each one of us had something valuable to contribute and everyone’s voice was heard. I look forward to the rest of Spring Term with them.


Sam assembling the blades of the wind mill with Andrew observing

unnamed (3)

Lucas testing out the pliers for Ollie

For more useful information, please click on the page labeled “Helpful Links/Videos” at the top of the website 

Completion of the Wind Mill

Today, we finished building our wind mill. It was very exciting as it felt like a race against the clock! The wind mill is able to light up a small, red LED light when the blades are spinning hard enough. This proved to be rather challenging because the blades are made of plastic, which makes them very light and they are not heavy enough to keep themselves going without a fan. We needed two fans on high power to make the blades spin enough so that the light would stay lit up. The base is also made out of plastic so it is not quite heavy enough to stay stable if the wind mill is moving quickly. However, our team worked very well together and everyone contributed to this success of completing the kit. unnamed (3) unnamed (4) unnamed3

Day 1 of Building

unnamed (2)

Sam tests out the gears

Our team has been working very quickly already! Sam and Ollie are our main engineers while Delia and Lucas help to keep the various parts organized and help with cleaning up the work space. Andrew will return to find that the base of the wind turbine is almost complete, with many of the gears assembled. As a group, we decided to use the longer “fins” as opposed to the shorter ones because we thought that it would generate more power. Only time shall tell! Even though on the box it says for children eight and up, we have found this kit still very complicated to build. Ollie and Sam are good at reading the directions while Delia and Lucas help them to find the parts. What a good team.

unnamed (1)

Ollie working on assembling the various gears


Ollie is building the base while Sam reads him the directions and Lucas supervises