New Course, New Manufacturing Process Affect Final Design

After coming away from Sunrayce 93 with many fresh ideas and the desire to improve our performance, we set out to design a completely new car. In the Fall of 1993, we began designing the next solar powered race car for Sunrayce 95.

The Aero Team was put in charge of designing, manufacturing, and testing the outer shell of the car. From our previous experience, we decided early on to go with a modular chassis and shell layout. This means that the shell and the chassis are independently designed. This makes the car easier to build, because both pieces can be built at the same time. And in the future, if changes need to be made to one of the components, the other component can remain intact. This also makes design easier by allowing the shell design to change without greatly affecting the chassis.

Since last fall, the shape of the car has undergone many changes. Probably the biggest contribution to the car's shape was the direction of the race.

In every previous major solar car race, the route was south to north. For Sunrayce 95, however, the route is east to west. This change in direction voided some of our design assumptions completely, and our selection of vehicle shapes changed. Basing the shape decision on our desire for light weight, small size, and aerodynamic efficiency, we decided to go with a low, airfoil-shaped car. This shape also fits well into our modular design philosophy.

After coming up with five additional shape changes, we now have our final iteration of the car. This means that the nose shape, solar cell configuration, and driver/canopy placement are finished.

We have also been working on a manufacturing process. From our experience with the last car, we

decided that our shell manufacturing process was successful, but our process for building the molds for the shell was not. This year, we have been given the opportunity to use a large gantry robot to mill the molds for Aurora-II. This will cut our mold making time by two months.

In addition to greatly increasing accuracy and surface quality, the molds also reduce the time necessary to make the shell pieces. The shell will be made in two halves that will be permanently glued together with a seam. The final product will be light enough for a few people to lift, yet strong enough to withstand a modern driving environment.

We have already begun manufacturing the shell and chassis, and we are depending upon the support of sponsors to make this an efficient and successful process.

Lance Molby