For the most part, it worked very well. The user simply had to pedal the bike to create energy. The back wheel was raised off the ground using a bike stand. A permanent-magnet motor was braced against the back wheel and another smaller wheel was connect to the motor's axle. This second wheel was in contact with the bike wheel and transferred the mechanical energy from the spinning to the motor, where it was transformed into electrical energy to power the light bulbs and various other appliances.The board held the bulbs, wires, circuit and other appliances in place, as well as featured some fun facts about the country's energy consumption and how the Energy Bike's output compares the average household's needs.
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| At the Presentation! |
We even made a video of how the energy bike works so that, should anything go wrong, users would still be able to see what our project outlines and how it functions.
Overall, we were very pleased with the outcome of our Energy Bike Project, though the final days leading up to it were quite a scramble to check last minute details.
We had to paint the motor brace and stands for the board:
We also needed to find a creative way to attach the two legs to the back of the board, as simply nailing them directly on was not working. In the end, we nailed them to smaller pieces of wood and then screwed the wood flush against the back of the board.
Because the wood was so thin, a few of the nails did stick out in places, we managed to hammer enough directly into it to keep it stable.We also added a simple voltmeter, so the user could see how much energy they were producing and be able to keep their output between 12 and 15 volts (that is the range that the inverter could handle).
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| Voltmeter |
Finally, all that was left to do was glue our fact sheets on and make the front of the board aesthetically pleasing. We carefully planned how it would look prior to permanently gluing everything into place.
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| Organizing Information |
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| Making Everything Fit Nicely |
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| Final Taped version |
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| Final Product |
We managed to finish the entire project early the night before the presentation. We even found a hairdryer with a low enough power requirement to be powered by our bike.
Finally, we had to test everything to make sure it worked properly.
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| Testing |
Then, after a good night's sleep, it was time to show the world what we had made.
Overall, the presentation went well. Unfortunately, about twenty minutes in, the small wheel attached to the motor fell off and never quite stayed on correctly. Originally, we had thought that the glue was melting under the heat caused by the friction and resistance between the motor wheel and the bike wheel. However, the glue we had used the night before was heat resistant. That meant it was the tape that could not endure the heat. We tried fixing the problem with aluminum tape, but the glue did not have sufficient time to dry before we used it. In the end, we used duct tape and a small object to brace a small piece of wood to the other side of the brace to keep the wheel from falling off. It worked for a while. The wood pushed back against the wheel as it tried to fall off and kept it in place. Eventually, though, the glue and tape between the axle and the wheel could not withstand the heat and stopped holding the two together. Though the wheel was staying in place, it was not turning the axle, so nothing was powering the lights. If we had more time, I would have liked to explore other wheel options. Though it may have worn down, perhaps if we had made a Delrin wheel and directly glued it to the axle, the motor wheel might not have fallen off.
Overall, though, we had fun and our users did learn about the importance of energy efficiency. The ones that got a chance to pedal felt the difference between powering the incandescent and powering the fluorescent lights. I think we really delivered our message to our users, and I am very proud of what we accomplished in such a short amount of time, whether or not it worked perfectly every time.
I had a lot of fun working on this project. I was extremely difficult, and though I went into it nervous, I ended up learning a lot about circuitry that I never knew before. Christina and I got along quite well, and I think I will always remember our late nights together in the lab.
Here ends the story of the construction of the Wellesley Energy Bike. We hope you've enjoyed the ride as much as we have.
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| Team Wellesley Energy Bike! (Christina left, Kat right) |
For our references about the country's energy consumption, please see:
For the Wellesley Energy Bike Official Site, see
<http://wellesleyenergybike.blogspot.com/>
For Christina's Blog, see
<http://christinaholman-engrportfolio.blogspot.com/>
