technizzel

The Cornell Baja Racing team designs, builds and races an off-road vehicle. We participate in the SAE Midwest Regional competition, which includes events that test the maneuverability, suspension, and acceleration of the car, as well as judge its design and cost. The climax of the competition is the four hour endurance race.

Our team is made up of undergraduate students from four different colleges in the university, although most of our team members are engineers. We spend the fall semester designing the car and testing prototype improvements on previous cars. The spring semester is spent building and testing the car before the competition in June. The car is designed and built from the ground up each year, solely by students.

Joining a project team is extremely fun and rewarding. On the Baja team, even the youngest team members contribute to the design and manufacturing of our car. Fabrication is usually the first skill that new team members acquire. Many hours of practice using mills and lathes pays off, because when the car is finished you can point to a suspension upright or pedal and say, “I made that.” As members of the team gain experience through classes and sticking with the Baja team, they begin to design parts of the car as well. These design experiences often reinforce coursework, or develop skills before they come up in class.

Being part of a long-term team gives great experience in preparation for working in the industry. Learning how to design pieces of a large system is emphasized from day one. As others’ parts change, you must make changes to your work. This constant process requires patience and flexibility. Working on a large team also requires you to learn how to listen to others’ criticism of your work, and how to give useful criticism back. The creative process that goes into designing a car requires that everyone give input and that everyone listens to the given input.

Since the Baja team is about designing and building an off-road vehicle, test driving is done on trails in the woods, rock quarries and ATV test tracks. Everyone on the team gets to drive, which means that everyone on the team comes back muddy and dirty. The experience of driving a car which you helped build is unmatched by any other experience as an engineer. Especially when you can drive that car off of a really big jump.

The first part of creating the Baja car is to design it. Using CAD and other tools, the team creates a complete model of the car before ever touching a milling machine or welder. It is much faster and cheaper to experiment in a computer model than it is in physical space. Fitment of parts is done in CAD, as well as creating steering and suspension geometries. After the model is done, fabrication of the car can commence.

The frame of the Baja car is constructed from chromium molybdenum steel or “chromoly”. This is easily machined and welded steel, and also has a high tensile strength. Each frame bar is cut and mitered in order to create a triangulated frame. After each piece is fitted, the frame is welded using Tungsten Inert Gas welding (TIG). When all of the welding is complete, the frame is painted to prevent rusting.

In the Baja SAE competition, all teams are required to use the same, unmodified engine. Given this constraint, one of the simplest ways to go faster is to have as light a car as possible. The Cornell Baja team reduces the weight of the car in several ways. For metal components, designing parts that are only strong enough for the stresses they are expected to encounter saves weight. The analysis of these stresses requires Finite Element Analysis. Another way that Cornell Baja lightens the car is through the use of composites. We are increasingly using carbon fiber to replace metal sections of the car, such as the steering wheel and steering shaft. The body panels of the car are also made from composites, fiberglass for the side panels and Kevlar for the floor.

The four day competition is the most exciting time of the year. There are two days of safety inspections and static design presentations. The next day is dynamic events such as acceleration, maneuverability, suspension and traction, and hill climb. The highlight of the competition is the four hour endurance race on the last day with all 140 cars racing at once. This event is worth the most points in the competition, and is the most exciting to watch. Cars crash into each other, roll over, break down, and even catch on fire. Almost a third of the teams do not finish the endurance race, so durability of the car and smart driving are very important. One year, we had to rebuilt the drive train in the middle of the race but still managed to finish the race. In the three years we have competed, we have finished the endurance race each year.

In the three years that the Cornell Baja Racing team has competed, we have made significant strides in our performance. Each year we learn more about the technology involved with making a successful car. This year, the Cornell team is working toward its first championship.

This entry was posted on Monday, January 14th, 2008 at 11:11 am and is filed under Cornell University, Student Groups, Automotive, Mechanical Engineering. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.