The fastest road from an engineering classroom to a manufacturing career may be a race track that engineering students from colleges across the U.S. and around the world take when they participate in Formula SAE competition. Organized by the Society of Automotive Engineers, Formula SAE challenges students to design, build and race open-wheel prototype race cars. It gives the students a hands-on, real-world perspective on designing for manufacturability with the opportunity to test the results.
Alex Marshalek, a junior studying aerospace engineering at the University of Michigan in the fall of 2018 and captain of the school’s MRacing Formula SAE team, explained: “Manufacturing experience is paramount for the education of an engineer. It allows you to understand what can and cannot be made with various manufacturing techniques. In Formula SAE, you use your knowledge of engineering concepts and apply them to a real-life vehicle, where performance actually matters. Classes tend to not have that hands-on component. This competition really gets you working with tools, metals, and machines.”
Now in its 32nd year, MRacing has about 20 members, all undergraduates. The students work in their free time and don’t receive university credit for their efforts with the team. Nevertheless, Marshalek said, “It does tend to help with jobs when companies see that you have those skills and that experience. Competing with other teams and dealing with sponsors and industry representatives also provide networking opportunities.”
Support from Seco Tools
In support of its racing efforts, MRacing seeks sponsorships from automotive and technology-related companies in the form of monetary donations, consulting or equipment. “We talk to companies, and they like to help out,” Marshalek said. Metalworking suppliers play a prominent role in MRacing’s machining processes. Seco Tools LLC, Troy, Mich., provides the University of Michigan team with advanced metal-cutting tools for its CNC mill and CNC turning center.
“We use some of Seco’s end mills, such as its Niagara Cutter Stabilizers, on the milling machine. The tools are mostly 0.625″ [15.88 mm] in diameter and smaller, with three flutes on the ones used for aluminum,” said Marshalek. “Tool cutting lengths will vary from 2xD to 3xD. On the turning center side, Seco supplies us standard turning inserts and those with its Duratomic technology. We also have grooving tools, and we hope to incorporate the use of Seco indexable insert drills in the coming year.”
The most recent version of Stabilizer 2.0 end mills incorporates patented continuously variable asymmetrical geometries and provides smooth and chatter-free performance that allows feed rates to be doubled as compared with previous models, according to Seco Tools. Duratomic technology manipulates coating components at the atomic level to achieve improved mechanical and thermal properties based on textured, alpha-based Al2O3 coating.
“Currently we use about 20 end mills and 60 inserts and rely heavily on the Seco website (www.secotools.com) for speed and feed recommendations, dependent on the material, which is a good starting point,” added Marshalek.
Each year the team performs a full design, build and test cycle and manufactures a car from the ground up. “The only components we don’t build are essentially the engine and some suspension parts,” Marshalek said. The team will, however, modify the engine to gain the best performance possible.
The cars are one-third-scale open-wheel racers in the style of Indianapolis or Formula One cars. A typical car weighs about 420 lb (190 kg) without the driver and has at least a 60″ (1.524 m) wheelbase and a fully independent suspension. The 2018 MRacing car has a turbocharged Honda 600 cc, 85 hp (63 kW), inline four-cylinder gasoline engine that powers it from 0-60 mph in 3.1 seconds for speeds up to 80 mph (129 km/hr). Autocross time trials, however, involve a small course with tight corners and the average speed is about 45 mph (72 km/hr). “They don’t want you going too fast,” Marshalek said.
The MRacing team shop mills and turns parts from 6061 and 7075 aluminum and mild steel and plans to make more parts from titanium in the coming season. The bar-fed turning center produces parts in multiples, such as adjustment spacers. According to Marshalek, the team will “set it and forget it” and do other things while it runs. “There are some parts for the chassis that we make out of steel that take quite a while. Those will run overnight in lights-out manufacturing.”
The car design process stretches from May until October. Machining occurs from November to March, at which point the car is built and tested. Between March and when competition begins in May, the team machines spares for use throughout the racing season.
MRacing manufactures about 90 percent of the car’s components in house, totaling 300 to 350 unique parts, excluding spares. “When we are limited by capabilities, we send some parts out,” Marshalek said.
Tolerances are “nothing too crazy,” he said, “generally within 0.001″ [0.03 mm], but a few parts such as bearing surfaces can be tighter—0.0003″ [0.008 mm], + 0.00″. Surface finish is critical as poor surface finishes will lead to stress risers that can, in turn, cause failures. “We get a good finish on the mill and sand out any machining marks. We’ll anodize some parts to improve their surface toughness, while others will remain uncoated,” Marshalek said.
Much of the machining is aimed at material removal to reduce the weight of the car and thereby make it faster. Often, complex geometries “make workholding challenging. It’s doable, but we may have to be a little more gentle on the machining side. All of our parts are as light and small as possible,” Marshalek said.
Four members of the team are selected as drivers, based on track trials of those who are interested. Each area of focus—such as design, suspension, brakes, and chassis/monocoque—has a student leader who reports to the team’s technical director.
Marshalek said machining is a new experience for most of the students: “It’s always cool to see metal-cutting for the first time.” The team has a training program to familiarize team members with machining processes. Team members begin working with a manual machine under the guidance of a more-experienced student mentor. After learning to process several different parts and becoming capable of running the machine safely and comfortably, the team member may be promoted to operator and move to the CNC equipment.
MRacing usually competes in three official competitions each year. They are run at Michigan International Speedway in Brooklyn, Mich., Barrie Molson Center in Barrie, Ontario, and an overseas venue, most recently in Barcelona, Spain. A competition consists of eight separate events. Points are awarded in three static events: engineering design, cost and manufacturing analysis, and business presentation. The teams also earn points in five dynamic events, including acceleration, skid pad performance, autocross, fuel economy, and endurance. The team that earns the most points wins the overall competition.
In 2018, MRacing placed 9th out of 120 teams at MIS, 2nd out of 28 teams at Barrie, and finished 1st out of 19 teams at an unofficial pure racing competition outside Pittsburgh.
For more information from Seco Tools LLC, go to www.secotools.com, or phone 248-528-5200.