NASCAR’s Legacy Motor Club Turns to BigRep for 3D Printed Rocker Extension Skirts

Legacy Motor Club, the NASCAR team owned by racing legends Jimmie Johnson and Richard Petty, recently had to produce new parts to conform to NASCAR regulations issued in the fall of 2024. Ahead of the Atlanta Motor Speedway in February, 2025, Legacy Motor Club’s Director of Aerodynamics, Steven Sander, used the BigRep Studio to quickly design and print one of the parts required by the new regulations, a rocker extension skirt.

While owners of consumer vehicles may often add the extension skirts as an aesthetic preference, NASCAR primarily mandated the addition of the skirts in order to decrease the potential for the sort of liftoff that can lead to crashes. Sander explains the engineering principles at play in the YouTube video that you can watch below:

After car number 42, driven by John Hunter Nemechek, had a top 10 finish at the Atlanta Motor Speedway, Sander noted in the video, “Overall, we’re very pleased with the performance of the [printed] parts that we put on the car. Coming up on the printer, we’ve got a lot more production parts: we have things for gear cooling going on right now, just to get ready for the downforce races in Phoenix, Vegas, and Homestead, so stay tuned, we’ll have more coming your way.”

Perhaps the most intriguing angle revealed here is what Sander mentions at the beginning about how “NASCAR provided [Legacy Motor Club] with the DXF cut file” to enable the team to produce the part with water cutting. Since Legacy Motor Club has BigRep printers on-site, however, the team was able to export the file to STL and print the extension skirt in-house.

Over the years, the objective of meeting and raising performance standards in auto racing has been a major boon to the increased adoption of additive manufacturing (AM) by the automotive industry. The wrinkle going on here is that, in addition to meeting the constantly recalibrating safety requirements demanded by NASCAR, 3D printing is also enabling the emergence of a distributed manufacturing network amongst its racing teams.

The little tweaks that NASCAR is always making to its rules likely couldn’t be effectively implemented in a timely fashion if the organization wasn’t able to digitally distribute the necessary manufacturing files — and if it wasn’t able to do so with the confidence that its racing teams could competently produce those parts in real time. As Legacy Motor Club’s experience with BigRep demonstrates, AM is an indispensable tool in making this distributed manufacturing network a reality.

The most exciting thing about this detail is that it suggests that the same process could easily be applied to virtually any industry with strict regulations determined by some central body. And that potential is made all the greater given that the process is already in place for purposes that are meant to increase the safety in a life-or-death scenario like auto racing.

Attendees of RAPID 2025 in Detroit (April 8-10) can learn more about BigRep and Legacy Motor Club at Booth 2325.

Images courtesy of Legacy Motor Club and BigRep