Revolutionizing Formula Student Race Cars with 3D‑Printed Carbon Fiber Molds and End‑Use Parts

The Formula Student is an annual engineering design contest where student teams worldwide build and race formula‑style cars. The TU Berlin team, FaSTTUBe, is one of the largest participants, fielding 80–90 students each year since 2005.

This season, FaSTTUBe is pushing the envelope by developing three distinct vehicles: combustion, electric, and autonomous. From fall to summer, the team undertakes a full cycle of design, manufacturing, assembly, and testing, judged on business model, design concept, cost report, and racing performance—particularly power, efficiency, and endurance.

To accelerate development and cut costs, the team added a Form 3 SLA 3D printer to its toolkit. The printer enables rapid production of parts that would otherwise be impossible or prohibitively expensive.

1. Prototypes: Rapidly printing prototypes for components such as anti‑roll bar mounts and high‑voltage battery brackets.
2. Molds for carbon‑fiber parts: Producing a dozen high‑precision molds that allow fabrication of complex carbon‑fiber components.
3. End‑use parts: Approximately 30 final car parts—button holders, shifter pedals, steering‑wheel switches, hose and sensor connectors—are printed directly from SLA resin.

Technical Manager Niklas Werner and Head of Aerodynamics & Carbon Manufacturing Felix Hilken guided us through these innovations.

Hand‑Laminated Carbon Fiber Parts on 3D‑Printed Molds

Last season, the steering wheel’s carbon plate was laser‑cut and its grips and electronic housing were built via selective laser sintering (SLS). To reduce weight further, the team experimented with hollow grips, but the material strength was insufficient. This year they chose carbon fiber, which offers superior strength‑to‑weight ratios.

Hilken developed a workflow that uses 3D‑printed molds for wet lay‑up lamination—an efficient way to produce carbon‑fiber parts with minimal tooling.

Watch the video to see how the carbon laminating process works.

Using carbon fiber, the steering‑wheel housing weight dropped from 120 g to just 21 g. Hilken designed and built the mold in a single day, enabling geometries that would be prohibitively complex to manufacture by traditional means.

"The beauty of 3D printing is that a complex shape is as easy to create as a simple one, using the same equipment and effort. Many of the features here simply cannot be produced cost‑effectively with any other process," Hilken explains.

Hilken laminated three layers of carbon fiber onto a 3D‑printed mold and then pressed the layers together using a secondary negative mold.

He selected Tough 1500 Resin for its balanced elongation and modulus—allowing the parts to flex and snap back during demolding. One mold can yield approximately ten parts, though the process is operator‑dependent; careful handling prevents fiber sticking or mold damage.

Compared to outsourcing CNC‑milled aluminum molds, this approach dramatically reduces cost and lead time. Without 3D printing, the team would have faced expensive tooling, long lead times, and limited design freedom.

Carbon Fiber Parts Manufacturing With 3D‑Printed Molds

Download the white paper for comprehensive composite mold design guidelines and step‑by‑step instructions on prepreg and hand‑laminating carbon‑fiber parts.

Download the White Paper

Costs and Lead Time Analysis

The in‑house 3D‑printed molds cut both labor and material costs. Assuming a $200/hour engineer rate, the comparison for the steering wheel is as follows:

	Outsourced CNC‑Milled Mold	In‑House 3D‑Printed Mold
Equipment	Carbon fiber, resins, tools, vacuum bag	Carbon fiber, resins, tools, vacuum bag Form 3 printer, Tough 1500 Resin
Mold Production Time	4–6 weeks	2 days
Labor Costs	$0	$300
Material Costs	$0	$10
Total Mold Production Costs	$900	$310

End‑Use Parts From Shifter Pedals to Cable Collectors

Beyond the steering‑wheel components, the entire set of steering‑wheel parts—button holders, shifter pedals, mounts, and switches—are printed on the Form 3 using Tough 2000 Resin for durability, then spray‑painted for a uniform finish.

In total, the car features around 30 SLA‑printed parts. For instance, cable collectors made from Durable Resin neatly organize harness tubes around the metal chassis.

"Those are great for assembling the wire harness because they look nice, and first impressions matter for the judges," Niklas notes.

The team also plans additional 3D‑printed enclosures, brake‑light terminations, and TSAL components for the electric vehicle—lighting indicators that reveal high‑voltage operation.

Prototyping a Generative‑Designed Part Before Metal 3D Printing

3D printing also plays a critical role in prototyping complex, topology‑optimized parts. The mount for the front‑end valve—designed via topology optimization—was printed in resin to verify fit before committing to aluminum metal 3D printing.

"Printing the prototype in resin was cost‑effective and allowed us to validate the design quickly. The part fits perfectly, so it will now be manufactured in aluminum," Niklas says.

Battery cell holders for the electric race car were also prototyped using 3D printing.

Finalizing the Cars for the Racing Season

FaSTTUBe continues to expand the scope of 3D printing across all three vehicles. A major upcoming project is a carbon‑fiber airflow intake that will require a multi‑part mold, assembly, and hand lamination.

The three race cars are slated for track testing in spring. Werner, Hilken, and the team anticipate the season will begin once COVID‑19 restrictions are lifted.