Day 1 of Making Prototype:
I started by cutting out the blades and the center of the windmill. I discovered a problem with the theoretical first plan, since using a cardboard windmill is very hard to reach the number of volts needed for the red light to light. Using the multimeter, I discovered the voltage the windmill could produce (by turning the fan fast using my hand) is at most 0.5 volt, and the LED light I plan to use needs at least 1.5 volts.
After identifying this problem, I asked Mr. Michie for feedback on my design, and he suggested that I should try using gears. Therefore, I started to consider using gears to maximize the voltage. When the fan is connected to the large gear, and the large gear is connected to the small gear, one round turned by the large gear would equal several rounds of the small gear; therefore, increasing the energy by at least 3 times.
Next time, I would start to put together the gears after I have made out a possible plan at home.
Figure 1 – Gear connection idea to increase energy production by the windmill.
Day 2 of Making Prototype:
Using my second plane and the second model (figure 3) that I drew; I started by connecting the blades of the windmill to the 5cm diameter gear. I then made a box for the gear to be connected to and used an iron wire to connect the box and windmill (figure 2). The problem I encountered is that because the blades, the gear, and the box are close together, the friction created is too high for the windmill to work without encountering a stop of blades hitting the side of the box. I asked Mr. Michie for feedback on whether the prototype is in an optimistic situation, and he suggested the same as I thought, which is the problem with friction. He also suggested that the cardboard prototype is not rigid enough, which I also agree since my current prototype does not seem stable.
Next time, I would solve this problem, a possible solution could be adding a piece of material that causes less friction between the gear and the box. I would also need to utilize the part of the motor tower and the connections between the LED light and the motor.
Figure 2 – Windmill front and side view.
Figure 3 – Second model (the first model is shown in the Develop and Plan post).
Day 3 of Making Prototype:
Today, the problem with friction previously mentioned is mostly solved by adding another gear onto the first gear (see the windmill part of figure 4). Using hot glue, I connected the 1.5cm diameter gear to the dynamite motor, added a piece of cardboard to the side of the motor, and connected the motor to the box behind the windmill. By doing this, I changed the idea of making another tower for the motor itself. I decided to only make one tower, which could avoid the problem of the two gears not matching up if the two towers’ heights are not measured correctly. To secure the motor, I hot glued a piece of cardboard with the dimensions of 2cm by 6cm from the bottom of the motor to the tower, holding up the motor. Afterward, I used 2 wires with alligator clips and connected the motor to the LED light (figure 5). Considering the light of the LED could be very limited, I changed the idea of making a cloud lamp since the cotton added onto the lampshade would block the already limited light.
My classmate (William Pan)’s feedback suggested that I could make the blades of the windmill longer, so it captures more wind and therefore increases the electricity produced. Next class, I would take this into consideration and try using a fan to test whether the windmill would work if possible. At last, I could paint the windmill white to make it more presentable.
Figure 4 – Windmill connected to the lamp.
Figure 5 – Wire connection to the motor.
Day 4 of Making Prototype:
Today, I added a 5cm addition to the blades of the windmill (figure 6) and glued the lampshade to the cardboard base (figure 7). Considering how the appearance of the windmill is not presentable, I used sand acrylic to paint the windmill (figure 7). Since most of the practical work is done, I worked on my documents and spent time revising my Create and Improve.
The design lab did not have a fan and we could not borrow one anywhere; therefore, I will bring a hairdryer to school next class and try out if the LED would work, and then make changes if necessary.
Figure 6 – Additional part to the blade.
Figure 7 – Painted windmill.
Day 5 of Making Prototype:
Today I brought a hair dryer to blow the windmill, but the windmill did not work as expected. Using the multimeter, the voltage varies between 0.5 to 0.8 volts. At one point, the motor reached 8 volts for two or three seconds, but it did not maintain there, and nor could it go back to 8 volts anytime during today. As a result, I surmised that it might be the multimeter’s error.
After checking several times that the wire connection did not have a problem, I tried changing another motor (figure 8). By testing the two motors several times, and connecting the multimeter directly to the motor, I concluded that the loss of energy was not because of the motors and might be that the windmill itself was not stable enough.
Figure 8 – New motor
Trying to find a better way of the design, I asked Mr. Michie and Ms. Amanda for feedback on the design. Mr. Michie suggested taking off the small gear and using a rubber band to connect the 5cm diameter gear directly to where the small gear was on the motor. This was to maximize more energy. I tried this idea out, but the motor and big gear could not hold the rubber band in a stretched-out state while the rubber band pulled the previous two together. Afterward, Ms. Amanda suggested using a piece of wood to substitute the small gear and put the rubber band around i. This too ended with the rubber band pulling the wood and the big gear too close together.
Considering the stability of the windmill, I changed the soft iron wire that was used to connect the windmill to the box into a relatively harder metal stick. After this change, the windmill has a much more stable connection to the box. However, after several experiments, the windmill still could not power the windmill.
The most problematic obstacle for my design is that I could not identify where the energy was lost in the cycle even after eliminating and redesigning all the places that could cause a major loss of energy. However, after comparing the possibilities of why the windmill could not power, I think the rigidness of a cardboard windmill is the most influential to my design, and I should have considered using a more stable material in my designing stage.
Figure 9 – Change of iron wires.
Figure 10 – Wire connection to LED light.