May Progress Update
We have lots to share since the last update on Pink Skies! First, Kyle and I finished school for the summer and have been able to work on Pink Skies full-time. Our first task was completing the batteries. We installed heat shrink and foam around the batteries to prevent them from being damaged and jostled in our 3100-mile adventure across the country.
The next steps involved lots of wire management and replacing fasteners in critical locations on the car with grade 8 and nylock bolts and nuts. Finally, once Pink Skies was looking clean, we installed the top piece on the vehicle. Unfortunately, installing the top piece ended up being a larger struggle than initially anticipated. It required one person to crawl into the car to hold the nuts holding the top piece to the car, while the other person tightened the bolt from the outside.
With the top piece installed, it was finally time to install the solar panels! We used aluminum rails meant for solar arrays installed on roofs, making the process significantly easier. In total, we installed five 445w Longi solar panels for a total output of 2225 watts. All five solar panels are wired in series and connected to our Midnite Solar charge controller. The energy from the solar panels flows into the charge controller, which steps down and regulates the voltage and the current to charge our batteries or power our motor.
With the solar panels installed, we could begin to test the car. So, we organized an opportunity at the Michigan State Police Test Track on Wednesday, May 19th.
Unfortunately, the test day did not go exactly as planned. We experienced serious issues with our steering system. Additionally, the car exhibited some unsafe stability characteristics that concerned us. On the plus side though, the rear end of the car and the electrical system performed flawlessly. We had an opportunity to test the car again at the track on Tuesday, May 25th, so we went to work making changes. During the track day, we were also joined by the newest member of our team, Danny Ezzo. Danny is a student at Michigan Tech University and will be accompanying us on the trip. Danny is super bright and has been a huge help in getting the car ready to roll across the country. Danny has lots of experience working on cars and his skills and abilities make up for a lot of what Kyle and I lack and we are incredibly grateful to have him as a part of our team.
The most significant change we made was moving the front wheels from the inside of the monocoque to the outside of the monocoque. Moving the wheels to the outside helped to make the car much more stable in crosswinds and while taking tight high-speed turns. The second thing we did was move the battery pack from the rear of the vehicle to the front of the vehicle; this additional weight over the front wheels helped to even out the weight distribution and make the vehicle to be more stable.
To validate that our modifications had fixed the unsafe handling characteristics we experienced on the track, we took the vehicle without the solar panels to a testing location and were absolutely thrilled with the results. Without any aerodynamic body panels, we were able to travel 40 miles using only 37% of our battery pack! Additionally, we could travel over 40 miles per hour with the motor set to draw 40% of its peak power. All of the unsafe driving characteristics we experienced during the first test were no longer an issue.
With all of our modifications complete, it was time to bring Pink Skies back to the track. This time, Pink Skies handled beautifully. We drove just over 100 miles on the track, and due to the track’s curvy nature, we had to travel slightly slower than we planned, but this meant our fuel economy was excellent. After driving the 100 miles and trailering Pink Skies home, we ended the day with more charged batteries than when we started. We are thrilled with the progress we have made on Pink Skies and plan on putting body panels on Pink Skies this coming week and doing more on-road testing. We are also now about three weeks from our expected date of leaving Okemos for New York City! Stay tuned for another update soon!