The automotive industry in Germany is under constant observation: higher environmental standards, electromobility and autonomous driving are just some of the factors that play a role. Not only car manufacturers, but especially automotive suppliers must therefore be very adaptable in the production of vehicle or spare parts. Automotive supplier Brose shows how 3D printing in particular meets the high quality requirements of the automotive industry and what impact this has on the production of vehicle parts.

Every second new vehicle worldwide has at least one Brose product. These include various mechatronic components and systems, such as seat structures, door components and various electric motors and drives. With 25,000 employees in 24 countries, the company is one of the largest family-owned automotive suppliers. As an innovative company, Brose is in a good starting position to integrate additive manufacturing (AM) into its products and production processes. The company uses various AM technologies for the production of prototypes, tools and fixtures. Series production using 3D printing is planned as the next step. One of the newest members of the printer fleet is the Fuse 1 from Formlabs. The first industrial benchtop 3D printer for selective laser sintering (SLS) is one of the tools that will support the company.

Use in an industrial environment

Brose's AM center in Germany is a one-stop store for prototyping, process development, material development and validation, providing parts for the whole world. The center started over ten years ago with its first 3D printer for fused deposition modeling (FDM). Since then, it has expanded its capabilities to include almost every AM process on the market - from stereolithography (SLA) to jetting processes, selective laser sintering and a large fleet of 3D printers. The printer fleet includes various SLS systems, from small desktop devices to the largest conventional industrial printers. The company has a lot of experience with this technology and was one of the first users of the Fuse 1 in Europe. "We have tested the Fuse 1 extensively. We print many parts with a minimum thickness as well as very thin and very long designs. When testing the parts, we found that any deviations in the dimensions were always consistent. So once you have optimized the process, you get highly dimensionally accurate parts," says Christian Kleylein, Project Manager Additive Series Manufacturing Polymers at Brose.

The team ran many prints on the Fuse 1 to test its limits - from short overnight prints that take about 12 hours to fully filled build chambers with more than 1,000 small parts that took four days. "The surface finish is very nice, very smooth, you see very few layers, which means you can use the parts once they've been media blasted after removal from the printer to remove the last bits of powder. You can produce very fine details," says Kleylein.

The Fuse 1 is designed to bridge the gap between traditional industrial SLS printers and more cost-effective, smaller format printers. It offers high quality, compact dimensions and a simplified workflow at a fraction of the cost of traditional industrial SLS systems. "It is more comparable to industrial printers than desktop devices. Thanks to the fiber laser, Formlabs has developed its own optical scanning system and the laser beam is redirected correctly," says Kleylein. You might think that larger printers would be more suitable for automotive parts, but Kleylein finds that the production volume is sufficient for most designs: "80 percent of the parts we print are about the size of a fist. So we can print all these parts with the Fuse 1. There are a few parts that are in the middle, and the rest are really big."

Spare parts and parts for end-of-life products

Brose plans to initially use the Fuse 1 for functional prototyping to take advantage of the fast throughput and Nylon 12 material, which has similar properties to current production materials. However, Kleylein's team is already validating parts and designing use cases, with spare parts and parts for end-of-life products among the first candidates. This is because in the event that a vehicle model is no longer produced, automotive suppliers are obliged to continue to provide spare parts. In the past, this meant estimating in advance how many spare parts would be needed, producing them by injection molding and then storing them. "That's a big waste of resources, space and money. If we print them, we don't have to store the injection molds and the parts for the next 15 years," says Kleylein.

SLS 3D printing is the ideal production technology in this regard. It enables the printing of high-quality parts with properties comparable to those of injection-molded parts. In addition, such a system can be implemented in a production environment. SLS is also one of the lowest-waste and cleanest AM processes. "Many customers like the idea because we are trying to print with virtually no waste. We can reuse the powder and there are no chemicals to recycle. We expect the SLS devices to be running waste-free by the end of next year," says Kleylein.

The future of SLS printing in series production

The aim in the near future is to use SLS technology in the series production of parts for the next generation of automotive products. Two important changes must be made to achieve this: AM must be factored into product development as early as the design phase. In addition, material and equipment costs must continue to fall. "The biggest obstacle is getting product designers to understand what is actually possible with 3D printing and getting them to print the part. You never achieve cost efficiency with components that are designed for injection molding. You have to design the parts for the process," says Kleylein. As the Fuse 1 lowers the barrier to entry for SLS 3D printing, it will play an important role in this shift in production.

Brose already has plans to rapidly expand its 3D printing capacities. The second plastic AM workshop is now being built in the USA, where a Fuse 1 will also be used.

Stefan Holländer, Managing Director EMEA at Formlabs