In Northwestern Mechatronic Design Laboratory, the Northwestern Solar Car Team (NUsolar) won’t miss one workshop on Saturday even when snow and cold temperature hit the city. On Jan 23rd, team members worked on their individual projects with help from teams’ leads, while a small team of people are working at the autobay and the machine shop in the Ford Motor Company Engineering Design Center. (photo credit/Hangda Zhang)
Aluminum machined rods mock up the skeleton of what solar car 7 is going to look like, after three mechanical team members screwed and tightened bolts between the rods.
This frame mockup is much simpler than the final solar car, but it gives designers a sense of the actual shape of the car that will use solar energy to race in the American Solar Challenge. In a part of the Challenge, the team will spend eight days traveling more than 1800 miles through 7 states.
NUsolar is bringing its sixth generation solar car to compete in the race this summer, starting from Pittsburgh. After the electrical team fixed the burnt-out electrical system with newly ordered boards from a company in Australia, Williams said the car is ready for the race.
The team started building its seventh solar car, SC7, at the beginning of the school year. The race organizers hasn’t released regulations for the next few years, but Spencer Williams, the project manager of NUsolar, made his decision on the changes for the new generation vehicle.
“Last year we got the car to drive,” Williams said. “This year we are trying to get the car to drive well.”
Williams went to the Innovators Educational Foundation Solar Car Conference during last spring break and discussed about the possible revisions of the rules with the Challenge officials. With his speculations on the future regulation and team advisers’ insights, Williams decided to give SC7 four wheels instead of three, build frame and shell individually, and decrease the length of the solar car. The mechanical team is building the new car while the electrical team is updating and improving the car performance.
The frame and shell were built in a holistic mono-coque that made SC6 lighter but restrained the flexibility for mistakes and corrections. Williams said SC7 will build the frame and shell separately, so the new generation will be heavier but easier to produce and fix its problems. It will now take the team two years instead of four to design and build the car.
“At the end of the day, it is an enduring race, so if we are trying to race for eight days straight, we want something that either won’t break or if it breaks, you can fix it really easily,” Williams said.
Besides on the engineering design, Williams made changes on the team structure with additional project management members in the business team. Those members help him form ideas to decide what direction and tasks the business team is taking.
The business team does any work that increases the knowledge of green energy in the community, gives back to the community, helps recruiting, raises funding and handles logistics on the competition and testing trips. One of the goals for the business team is to raise 80,000 dollars of cash and in kind donations in this school year, which posts a big challenge to NUsolar.
“The major challenge is to build the car in two years,” Williams.
The team needs to raise enough money to build the car and has to get all the material and train people to build all the parts. Just producing the carbon fiber shell will take whole one year, because they need to machine a 5-foot-wide 15-foot-long foam mould first, put carbon fiber into the mould and wait for the shell to cure.
NUsolar is still waiting for donation of cash as well as metals, mainly aluminum blocks, for frame, suspension and steering and and foam for aero moulds.
Since last spring, Williams started having Dan Li, a mechanical engineering junior, as mechanical lead.
“It makes my life easier,” Williams said.”I don’t need to worry about mechanical stuff that much.”
Li’s team has finished suspension and frame design. The team is still working on controls and aerodynamics – the car shell – design, in which aerodynamics requires junior or senior year knowledge, said Williams. Two graduate students are helping with it.
The electrical team has collected a lot of data from testing trips last quarter. Ethan Park, a computer science sophomore, analyzes data to give feedback about drivers’ performance and how they can improve on velocity and acceleration controlling. They are also making changes to the electrical design to ensure that the power management system sends the correct amount of power consistently.
Williams said, “I hope they (team members) can learn good engineering and business skills that they can bring to their jobs.”