July 10, 2007
Bob Hollingsworth, a member of Practical Welding Today's advisory board, details the journey of the 2006 Western Washington University Mini Baja vehicle fabrication team and their quest to build a winning off-road, student-designed racing machine.
Earning a reputation for innovation and quality is a difficult task. It is particularly difficult but equally impressive when this is achieved with a rotating group of students at a public university.
That is exactly what the Vehicle Research Institute (VRI) at Western Washington University, Bellingham, Wash., has done. Launched by Dr. Michael Seal, a former professor in the engineering technology department, in 1971, the VRI has been home to 33 successful, student-manufactured vehicles.
The VRI has entered student teams in the Society of Automotive Engineers' (SAE's) Mini Baja® competition since 1999. The annual North American series, which is divided into East, Midwest, and West divisions, has become a world-class engineering and design competition for U.S. and international university student teams. The competition involves the design and fabrication of a bulletproof, single-seat, off-road, adverse-weather, recreational prototype vehicle suitable for sale to nonprofessional, weekend racers.
Student teams from the VRI have improved steadily in the seven years since the VRI first entered the competition, including a 30th place overall in 2005. Under the leadership of Professor Eric Leonhardt, director of the VRI and full-time instructor at WWU, 2006 proved to be a banner year.
According to SAE, the object of the competition is to provide a challenging project that involves the planning and manufacturing tasks similar to introducing a new product to the consumer industrial market. Student teams must design, build, test, promote, and race a vehicle that complies with the rules set forth by the SAE, as well as generate financial support for their project.
Designing and building a race car from scratch is no minor commitment. The Mini Baja team at WWU is a volunteer-based project that places all of the responsibility for the design and fabrication of the vehicle on the students. Team members select a leader who then manages and delegates tasks to the appropriate people. Leonhardt said the experience level of each student varies. Some students are certified welders and certified mechanics, while others have little or no hands-on experience.
"This is a generation that's grown up more comfortable playing Nintendo® than most generations prior. They're comfortable with computers, but many of them have not had the opportunity to work with shop skills and learn about design and engineering," Leonhardt said.
Fortunately, Leonhardt added, many students remain with the team for two or three years, adding to the experience level and giving the less-skilled team members someone to lean on.
The 2006 team voted 22-year-old Craig Smith, a second-year team member, as its leader, and the design and fabrication process began.
It's not unusual for an individual student to dedicate 800 to 1,000 hours to the project over the course of a year. Smith said in the beginning of the year, team members devote anywhere from 20 to 30 hours per week to the project. In the weeks prior to the competition, however, hours worked spikes to 60 to 70 per week. This is on top of going to classes and managing other projects and tests. Fortunately, the importance of working within the Mini Baja team is not lost on WWU professors.
"A lot of professors see this as an important part of the curriculum. They are pretty lenient with letting us make up projects and tests after the competition," Smith said.
The competition is divided into two categories—static and dynamic—for a best possible score of 1,000 points. The static category, which represents a maximum of 300 points, includes the design, report, evaluation, and cost analysis of manufacturing the vehicle. The dynamic category, which represents a maximum of 700 points, includes speed and acceleration; traction and hill climbing; maneuverability; a rock crawl that would intimidate a mountain goat; and a four-hour endurance run on a technically challenging, 2.2-mile motocross track.
The required engine is a one-lunged Briggs & Stratton® 10-HP OHV Intek model 205432 type 0036-el. Briggs & Stratton Corp. has donated engines to the teams for 27 years. These mills must remain box stock, putting to rest any clever ideas about hot camshafts, trick carburetors, or a larger bore and piston. The company provides on-site technical experts to ensure a level playing field for all teams, relative to running identical engines. Kit vehicles are prohibited, and the students have to create the designs themselves. However, certain subassemblies, such as brake calibers, are accepted.
The 2006 team took this wealth of data and specifications, the requirements outlined in SAE's 70-page Consolidated Rules Packet, and after scrutinizing the results of six VRI teams who had entered Mini Baja cars in previous years, got to work. The design-oriented students, using CATIA® software to sculpt the frame, steering, suspension, drive train, brakes, engine room, cockpit, and controls, blended them together to form a race machine.
The fabrication phase involved making chips and welding. The frame and roll cage were built with chrome molybdenum 4130 steel tubing, as specified in the rules manual. Students then used gas tungsten arc welding (GTAW) to piece everything together (see Figure 1). A lot of original fabrication is required when building the brake, steering, driveline, and suspension systems. The team used standard lathes, mills, drill presses, and hand tools, as well as CNC machining centers (see Figure 2).
Piece by piece and weld by weld, the machine came together. If a subassembly didn't pass muster, then the team had to revert to the CATIA software to put a different spin on the component and then build it again. The team had to ensure that the vehicle would be able to withstand the rigors of racing.
A problem surfaced that had Smith spinning his tires, so to speak. The team had designed the suspension around a shock that they found out late in the process no longer existed. This forced Smith and the team to look for an alternative shock and mounting system.
"At first I was at a complete loss for what to do. I thought we were going to have to rebuild a lot of stuff. A few of us got together and figured it out. We ended up getting a shock that worked really well, and the whole car came together a lot cleaner than it could have with the original design."
Finally, after long days and lonely nights, the vehicle was born, which meant it was time for testing (see Figure 3). The team took their ride to Mt. Baker Motorcycle Club (MBMC), Bellingham, Wash. The club, home to challenging flat and motocross tracks, has spawned numerous topnotch riders, including the legendary Steve Baker, and was an ideal facility to test the Mini Baja. With the permission of MBMC membership, the team hauled the vehicle to the track for a test run.
After a series of drivers maneuvered the car around the track for 45 minutes, a flaw surfaced. The steering arms had broken down after completing numerous big-air jumps. The front wheel spindles, upright, and steering arm assembly failed during impact loading from the jumping that took place at the track. After static-based computations and CAD redesign endeavors, the team fabricated new assemblies with a strategically placed welded gusset. Smith wasn't too set back by the latest complication—the purpose of testing is to break the car in, which is exactly what they did.
Another round of testing at the MBMC track showed that the rebuild was successful, and the vehicle was ready for competition. Now the team had to deal with the logistics of moving 18 students, two faculty advisers, a race car, tools, parts, and provisions 250 miles south to Oregon.
The 2006 SAE Mini Baja West Chairman Ryan Jefferis, project engineer with Sterling Trucks Corp., Portland, Ore., and his committee from the SAE Oregon section developed a world-class, three-day event in which 83 teams from the U.S., Canada, India, Korea, and Mexico completed. Day one dealt with static events at the Portland, Ore., Expo Center. Days two and three were the dynamic events held across the Columbia River at MX Park in Washougal, Wash.
Just because the competition was well under way that didn't mean it was smooth sailing for the WWU Mini Baja team. During an event, one of the bolts on part of the suspension worked itself loose. The driver took the car into the pit, where team members then tightened the bolt. About 30 minutes later the spindle broke off, sending one of the front wheels flying off the car. Smith said it took another 30 minutes to replace the failed part, but the unfortunate mishap turned into a convenient off-the-cuff modification.
"We couldn't get our brake back on the tire, so we ended up just throwing it in the car. The next driver found out that when he hit the brakes one wheel would lock up but not the other. It really helped steer the car."
Initially the team had been told it had finished in ninth place, which thrilled the students and Leonhardt. To finish in the top 10 at an event like this is an outstanding accomplishment and holds a lot of weight for the students and the program itself. Unfortunately, after further review by the judges, the team earned 11th place, narrowly missing the coveted top 10 spot.
The WWU team did take home the Polaris Innovative Suspension Design award for its off-road suspension design and was also one of only 22 out of the 83 total teams to complete the endurance event. It also earned Sportsmanship Award honorable mention for assisting a foreign team. This particular team, which had never participated in the event, had a vehicle that was not up to code. WWU team members as well as personnel from other teams worked with them until 10 p.m. the night before the dynamic events to install seat belts, kill switches, mechanical guards, and other components, enabling them to pass inspection and enter the competition.
"Everyone is out there to help each other. We're not out there to leave anybody in the dust or let anyone be at a disadvantage," Smith noted.
Did the students learn and develop skills that will enable them to further their careers as engineering technicians? Yes. Amid the pain and strain, did they have fun? You bet. Team member Matt Coyne, who was named team leader for the 2007 competition, carried with him the lessons he had learned in 2006.
"Last year was really exciting. It got me pumped up for this year. I didn't know what to expect going into the competition, but it was a lot of fun."
Not only is the competition fun, but it gives students necessary hands-on experience as well as life skills such as time management, leadership, and teamwork that they will be able to take with them throughout their careers. They are also given the opportunity to find out how they stack up against other student engineers from all over the world.
"We continue to want to develop the best vehicle design students that we can. With the competition, they are demonstrating a positive return on that kind of educational investment.
"To know that we are getting close to being one of the top cars—that's what we're looking at," Leonhardt said.
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