American Tour de Sol

While studying at Rochester Institute of Technology (RIT), I got involved with the the solar racing team. The team name was spiRIT which stood for Solar Powered Innovation at RIT. The team had been established a few years earlier and was continuing development on a second generation car when I joined. They had competed in the Sunrayce sponsored by General Motors the year before. The gruleling race went from Michigan to Texas and the poor result, graduation, stress, and lack of funds left the team in shambles. A small group of us gathered as many new team members as we could to campaign the existing solar car in the Northeast Sustainable Energy Association (NESEA) Tour de Sol. It was scheduled as a four day rally event from Battery Park in New York City to Philadelphia, Pennsylvania. NESEA touted the race as "from the Statue of Liberty to the Liberty Bell."

Our first task as a new team was to completely disassemble the car to troubleshoot, improve, and rebuild it in time for the race in May 1994. The car consisted of a tubular space frame with four bicycle wheels. The outer shell was and an aerodynamic, teardrop shape constructed of glass and Kevlar reinforced honeycomb sandwich with an 1,100 watt solar array. The driver sat in a hammock style seat and there was a battery pack consisting of three strings of 13 twelve volt motorcycle batteries in an enclosure behind him. A 5 horsepower General Electric induction motor drove one of the rear wheels by chain drive. Our two major areas of concern for the team were repairing faulty strings in the array, and developing a more efficient drive train. The electronically commutated motor had no brushes to transfer current to the armature. This made the motor very efficient. Unfortunately, it had trouble developing starting torque at zero RPMs. To overcome this deficiency, the previous team was forced to use a centrifugal clutch system that was crude and inefficient. I had a pretty neat idea for a two speed clutch system that would allow the motor to start spinning before torque is applied. Also, having a low gear would counter the problem with excessive heat in the motor while climbing hills.

Of course, as with most engineering projects, there were competing ideas and concepts. Everybody had ideas, but nobody had a plan, I kept working out the details of my design and eventually made a formal engineering presentation to explain all the details to the team. We improved a couple areas and I worked up final shop prints. Still, the other camps wanted to do this, or wanted to do that. I finally stood up at one of our meetings and said "I'm going to the shop and am going to start making parts. We can't wait any longer. If you guys can finish your concept and build it before I finish mine, we will use yours" And so there I was, in the shop alone, making parts. I needed to cut splines in the clutch plates and since there were 3 plates per transmission plus a complete spare transmission, shaper cutting the splines would have taken way too long. I wanted to make a broach, but, Jim, one of the old codger instructors in the shop said, "oh, that is impossible. Broaches are 6 feet long and need a special press" Then he threw a book on the table to prove his point. I picked up the book and took it to the solar cell (our lab for working on the car) to learn broach design. After going through the calculations, I came up with a reasonable design and once again went to the shop and started making chips. They laughed. I made chips. Rochester Heat Treating hardened the broach blank for me and I used a tool post grinder to cut the relief. When it was ready, I took my clutch plates to the press, pressed the broach through, and had a beautiful spline on my clutch plates that fit perfectly on the main shaft.

Of course, as with most mechanical designs, half the work is in the design, the other half is in the interface. It took a lot of time to install the system in the solar car and make it work. As time started to run low, I just stopped going to classes and lived full time in the solar cell. The last three days were 24 hours long with naps in a pile of tarps in the corner, or passed out under the car. I took a big fat 0.0 GPA for that quarter, but I finished my design and it worked. Years later, I feel that what I learned in that stressful quarter with the team is used every day in my job. The classes that I took a failing grade in are dusty memories.

The testing before the race consisted of a standing start on a loading dock ramp at school and two laps around the parking lot. We stuffed the car in the trailer and left for the race. We took my GMC van and the solar van that GM had donated to the team. The team also shared a 40 foot enclosed trailer with the SAE formula team that housed the solar car, the solar array, and a miniature machine shop for repairs that might be needed. We left at 1PM and I had to drive my van. I've never hallucinated so much in my life. The total lack of sleep for 60+ hours and gallons of coffee combined as an out of body driving experience. I followed the other van and just focused on the back of trailer for hours. We finally got to battery park at 6:30 in the morning on Sunday and registration and technical inspection were scheduled for 9:30. So, after all those hours, I still couldn't go to sleep. We struggled to get the car through tech and then I got to sleep in my favorite pile of blue tarps wedged between the trailer and the fence.

We were able to use the entire day to finish preparing the car for the race start the next day. The next morning we were off. The first leg of the race took us through the Lincoln tunnel and the team was worried about breaking down in it. We had the option to take a penalty and bypass the tunnel and go straight to the closed course qualifying event later in the day. I insisted that we make the attempt and we made it with no problem. Everyone was worried about the untested drive train, but my design was sound and I had great confidence in it. Our driver liked having low speed and the simple method of shifting from low to high. Basically, he had a lever that defaulted to high gear with neutral in the middle and pulled all the way back engaged low. To start out, he would hold the lever in the neutral position, get the motor going and slowly pull the handle the rest of the way into low. After gaining momentum, he would let off on the throttle, release the lever and continue driving with the transmission locked in high. We never had any trouble with the clutch slipping and the efficiency of the system was higher in the race that we had seen during testing with the old design.

Once we got to the Liberty Science Center in Liberty State Park (behind the Statue of Liberty), we displayed the car and waited for our qualifying session. Start times the next day were based on the time to complete laps around the closed course around Liberty State Park. RIT's start position was 32nd.

Tuesday, May 24th was the start of the tour to Philadelphia, Pennsylvania. It was another perfect clear day and we left the Liberty Science Center and headed for the mid-day stop at the Jersey Central Power and Light building in Morristown, New Jersey, The race continued to the final stop for the day at the North Hunterdon High School in Annandale, New Jersey. A total of 63 miles had been covered with no problems.

Our race strategy group followed the solar car in the solar van. We had a wireless modem that captured all the data on board the solar car and transmitted it back to the van. There we could monitor critical parameters like voltage, power, temperatures, speed, efficiency, etc. The strategy group could make decisions and communicate with the rest of the team. We had a scout vehicle with two team members that stayed about 10 miles ahead to feed information back to us about road conditions, traffic and weather. We had a lead vehicle that stayed just ahead of the solar car and could help with intersections and traffic. Finally, we had the other van to haul the trailer to the next pit stop and set up camp for us, and if needed, come rescue the car.

At the beginning of Wednesday morning's run to Lyons PA we had a full charge on the batteries from the beautiful weather. We learned very early in the race that we did not necessarily have to stop for traffic lights. We would have the lead vehicle go into the intersection. A group of team member wearing orange vests used flags to stop traffic in both directions. There were four team members in the car and it had a yellow hazard light on the roof. The solar car and strategy van would roll through the intersection, and the lead vehicle would leapfrog past us and resume the lead position. Over the radios we code named it 100% efficient regen. It worked like a charm.

In the evenings, we would do the daily maintenance on the car while the array was placed in the "houjie". It was a special frame to hold the array with surveyor tripods on each end to hold it up and position it. We could direct it toward the sun and charge at maximum rate. The pit team would scout around for the highest parking lot before we got there and we would trailer the car up to it for maximum evening sun. The rules specifically banned any type of reflecting "device" to collect solar energy. We would put white sand on the ground and it would increase the power we took in but didn't violate the rule.

The second day of the race, we stopped in Lyons, Pennsylvania. It is the home of East Penn Manufacturing Co, makers of the Deka line of batteries. They hosted tours of their battery manufacturing plant. The tour guide said that they recycle 25,000 lead-acid batteries every day, recovering lead, plastic and sulfuric acid. One hundred percent of the lead, plastic and the acid go back into producing new batteries. They make industrial and commercial batteries ranging in size from a couple of ounces to over 20,000 pounds!

Thursday, we left Lyons and raced to the Mayfair in Allentown, Pennsylvania. The Mayfair is a festival of food, music, arts, that is an annual event. Each of the towns we stayed in, there was a carnival atmosphere around the solar cars. The entire town would come out to see the cars and thousands of kids were inspired. It was interesting to go around to the other teams and talk with the different colleges. You could look at their cars and say to yourself "wow, what a neat way to do that". The whole race event was really just to showcase solar energy and the current state of the art technology. Also, the event was geared to spark interest in people and to show that electric vehicles were viable technology. In addition to the pure solar cars, there was a fleet of conversion vehicles that simply charged up their cars every night.

After an additional 40 mile lap bonus event, there was a hill-climb test. This was a good test for our transmission and the SpiRIT IV car made it up the hill. We discovered that the motor on the car had been damaged from excessive heat and there were only two spares -- one with an aluminum heat sink and one without. We repaired the car that night and were ready for the run from Allentown to Boyertown. However, not far into the run we lost the second motor and had to repair the car on the side of the road. It is troubling to sit on the side of the road while the other teams go by. Once we got the car going, we nursed it the rest of the way to Boyertown.

That evening, the teams were permitted to charge the cars off the grid for the final run into Philadelphia. The problem was, since this was going to be a drag race with all the cars fully charged, the last motor without the heat sink would not make it. We thought about it and went to the local hardware store. We bought a small, pump style bug sprayer, some tubing and fittings. In the pits, we cut the nozzle off the bug sprayer and added a length of tubing. The bottle and pump were mounted by the driver and the nozzle was directed at the motor. It was sealed with silicone and shrouded by a plastic milk jug, modified to fit. Nothing in the rules said we could not add water to the car. Whenever the car stopped, four team members would get out. One held the funnel in a hole cut in the canopy. The driver held the sprayer bottle up to it while another poured distilled water in. Everybody got back in and we would continue on. You could see a trail of water dripping out the wheel well. Other teams complained, but there was no rule prohibiting it and it worked like a champ.

We finished in second place, a penalty we received for running a stop sign bumped us to third. Since we had run every stop sign and traffic light since New York, it was a fitting final result. Overall, RIT placed third in the continental race class of the 9 teams that entered. The car and the team made it the whole way and competed every mile of Tour de Sol. I got suspended from school for failing all my classes, but it was worth it. I will make a car and compete in Tour de Sol in the future.