Brain Storming
The second step in thinking of a design is brainstorming. To brainstorm, you use several different problem solving techniques in order to find solutions for any possible obstructions that might stand in the way of achieving a functioning model. In this situation, we had a few complications to think through before we could start researching different ideas.
Original Racer
The first problem we encountered was how to get the wheels of the racer to move by only using a rubber band. We knew that the more you twisted a rubber band, the tighter it gets, creating more tension within it. The rubber band, when released, would spin in a certain direction. The way the band spins, if attached to the axles, would spin the wheels, causing the racer to move.
The next problem we encountered was the material choice of our racer's body. Since rubber bands don't really exert a lot of power, we decided that using lighter materials would be much better. This would make it so that the rubber band didn't have to spin as much on a lighter racer rather than a heavy racer. If we used heavy materials, we would need a stronger rubber band or twist the rubber band even more and risk snapping it. Using lighter materials makes the racer more aerodynamic and easier for the rubber band to move.
The third problem was what materials to make the wheels out of. We needed to find something that was available to us and would be able to move the racer quickly. At first, we thought that water bottle caps would be a nice choice for wheels.
During the brainstorming stage, we decided to create a racer with four bottle caps as wheels with a body made out of light materials and to attach twisted rubber bands as the applied force.
Final Racer
We had many problems from the failure of the first design and started at the faulty points. Through thinking of ways to fix the original racer, we came up with a whole new ideas.
We realized that using bottle caps for the wheels would not work. Water bottle caps have a very small circumference. That means that the cap would need to rotate a lot more times in order to achieve the same distance as a tire would. Plus, the caps were slanted, making it so that the racer did not go straight. This was a problem. We searched for a new material to use for the wheels and came up with four CD's. The CDs have a bigger circumference than the water bottle caps, making it easier to go further distances.
There was still another problem that came along with using CDs for wheels. They are very thin and have little traction. We wanted to wrap the CDs in another material that would make them thicker. We decided on tape.
Another problem we had was the construction of the body. Every time we would twist the rubber band, the water bottle body would fold up and crinkle. This would make it so the wheels were not even. That was very problematic. Using a different, sturdier material would be better for the body.
The biggest problem we had was figuring out what the rubber bands would attach to in order to become the power source and spin the wheels. We knew that twisting the rubber band one way would cause it to unravel quickly in the opposite direction. We decided that by attaching this to the hind axle, would could spin the wheels through that.
During this stage, we decided to use light yet sturdier materials, including CDs wrapped in tape for the wheels, and to attach the rubber bands directly to the axle.