Final Project: The Puzzle of Editing the Prototype

Today, my partner Christina and I worked to improve our first model of the Energy Bike set up. We had a lot to do.

We started by addressing several of the problems we noticed from our previous work day. The motor tended to bob up and down when the bike wheel was pressed flush against its axle. I built an arch onto the motor stand and brace to counteract the force of the bike wheel and keep the motor steady and in place.

Brace with Attached Arch

This held the motor quite well, and the friction between the wood and the motor itself was an unexpected bonus that kept the bike wheel from accidentally turning the motor itself if the wheel happened to brush it.

Next, we turned our attention to the wheel. The wheel we had originally attached to the motor axle was too big, and the user could not generate the needed RPM to reach 12 volts (without being Lance Armstrong, that is). We needed a smaller wheel or the Energy Bike would be too difficult for an ordinary user to manage. 

However, once we attached a smaller wheel, made of PCB pipe, pedaling was far too easy, and the user could easily outdo 12 volts (in one instance, we managed 21) and drive the inverter wild. We needed to find a wheel size in between the two that made pedaling a chore, but not an impossible one.

Original Wheel on Left, Smaller Wheel on Right

     

Final Wheel Upper Right

In addition to being the middle ground between our two original wheels, the new wheel also solved the pedaling problem: it is much easier to maintain a constant current with this sized wheel. Because pedaling is simpler with this size wheel and a constant current is easy to maintain, an extra battery pack may no longer be necessary.

Next, we moved onto the switches. Our store-bought switches were designed to turn a circuit one or off, not switch between two different circuits. In other words, we could not put our bulbs in series with these switches. After much deliberation, we decided to edit the switches ourselves rather than return them and locate the right ones to purchase. We simply turned the ground prong (green) into another option within the switch to allow the current to flow in one of two directions depending on what direction the switch was flipped.

 

New Circuit Diagram for In Series Design

Getting it In Series...

We Had to Break into the Switches to Edit Them

An Edited Switch, Ground is Now an Alternate Route

Now that the switches are all fixed, we can put the circuit in series and test as to whether or not it works in this manner.

Finally, we began to decorate our board and attach safety instructions and fun facts. We still need to figure out how we are going to qualify the concept of kilowatt-hours to the user in layman's terms, but our first priority is to make sure the user understands how the Energy Bike works so they do not get hurt while using it.

Decoration Plans

Testing

Despite all our progress, there is still a lot that needs to be done.

1.) The board needs to be decorated for real
2.) The switches need to be covered slightly so that only the switch part is visible to the user
3.) The NEW circuit needs to be tested with the bike
4.) We need to get a more permanent bike for the display - Christina needs hers back for the summer

However, for the moment, we are ready for the final week of preparations and we can not wait to see how our project is going to turn out.

One bulb down...seven to go.