Final Project: The Puzzle of the Prototype

Today, Christina and I began constructing our first version of the Energy Bike.

We had to gather our materials, first, but after some shopping on Amazon, eBay and a trip to Lowes, we were all set to go.

Putting Together the Supply List

Our Adventures at Lowes

Our Shipped Inverter and Motor

All the supplies came in on time and we were able to start building. First, I set out to construct a brace to hold the motor against the back tire of the bicycle. I mounted some rubber Lego wheels on the axle of the motor to act as a gear with the bike tire. It had to be sturdy enough to stay in place as the user pedaled, so around the stand I constructed a frame that used the bike stand to stay in place.

Bike and Bike Stand

Preparations

Motor Wheel

Completed Motor Stand and Brace

Bike and Motor

Though crude, the first iteration of the motor stand and brace worked fairly well. We then tested it to make sure the set up would allow the user to generate power by pedaling.

Success! Though, it did not produce as much power as we were hoping it would.

With our energy source working properly, we turned our attention to the physical board. I began cutting holes for the switches and lights while Christina worked on the circuit that would attach to the back.

Holes for Lights and First Switch

Switches and Holes Completed

Soldering the Bulb-Holders

The bulb-holders all came with hook attached to them, so all we had to do was drill holes large enough to accommodate the hooks and hang the bulbs from them. Christina soldered copper wire to the bulb-holders so they could reach the circuit no matter where we placed them. We placed the bulb-holders on the board and began connecting the circuit on the back.

Bulb-Holders on the Front

Front with Bulbs

Completed Circuit

 As it turned out, our circuit was incapable of being an in series circuit, as the switches were only on/off in set up. We will have to make another trip to Lowes or find a way to wire the circuit to work around this issue. Additionally, we had to change the placement of the first switch(s) to accommodate for this and allow the user to only have one string of lights on at a time.

Meanwhile, our motor stand and brace began to have problems. The bike tire eventually began to tear up the tiny Lego tire, and no amount of duct tape could prevent this. We are now planning on using PCB piping to create the otter layer of the wheel to prevent this from happening. Additionally, the user has to pedal an inordinate amount to light just a few bulbs. We think that this is due to the size of the wheel attached to the motor: it is too big and thus not allowing the user to reach the optimum number of rotations per minute. Hopefully, a smaller wheel will solve this problem. The stand and brace itself began to fall apart, so I designed an new version and sealed all the edges with hot glue to keep it sturdy.

Stand and Brace Iteration 2

The new stand works much better than its predecessor, but the motor has a tendency to dip under the pressure of the bike wheel, s it lifts off the stand after and certain amount of time passes. I plan on adding a brace on top of it to fix this problem.

Finally, after all this, we tested our product to see how well it worked over-all.

Inverter

Plain Board

Final Decorated Version

Overall, it was successful. Though various aspects of the prototype would begin to have problems, for a few minutes after each fix, I was able to pedal fast enough to light all the fluorescent and three of the incandescent bulbs. Now, because we know the bike works, we only have to work out the kinks. 

1.) The motor needs something to hold it down and a smaller wheel

2.) The switches need to be exchanged for ones that allow an in series circuit

3.) The board needs to be decorated and the outlet added

4.) A nine volt battery pack may need to be added so the user does not have to pedal so hard to light just one or two bulbs

Despite its flaws, our prototype does work. This model has dramatically reduced our fears about the outcome of this project, as we were beginning to worry if we would be able to get Any of the bulbs to light with just pedal power, given how low the output was o the voltmeter when we first tested the motor. However, the electrical portion of the project is, for the most part, completed. All that is left to do is to make the physical components more stable, durable and attractive for our future users.

The future of the Wellesley Energy Bike looks rather....bright.