Riding into a 3D future with BMW
The German carmaker is testing new materials and processes as it looks to use more additive-produced parts in vehicles
BMW has over 30 years of experience in additive manufacturing. The company first started making prototype components for its concept cars using 3D printing tools back in 1991 and began to introduce plastic-based processes in small-series production slowly. By 2012, it was making plastic housing components for hazard warning lights, center lock buttons, electronic parking brakes and sockets for the Rolls-Royce Phantom, as well as mounting brackets for fiber-optic cables in the Rolls-Royce Dawn. The first series of metal-based components—fixtures for the soft-top attachment—entered production in the i8 Roadster in 2017.
Creating the right conditions
Three years later, in 2020, BMW opened its Additive Manufacturing Campus in Oberschleißheim, southern Germany, consolidating its activities under one roof. The €15 million investment allowed the company to greatly expand its efforts in the field, providing a center to focus on personnel training, R&D and AM-friendly design. It also provided a space for the carmaker to address the primary challenges for additive when it comes to use in automotive. Speaking to VoxelMatters, Jens Ertel, Head of BMW Additive Manufacturing, outlined these challenges.
“The biggest challenge for us is lowering the material and process costs, which ultimately result in lower cost-per-part,” he confirms. “Only with the use of the right technology, materials and, above all, the right design of components, can the full potential of AM technology be exploited.”
Another big challenge, Ertel continues, is the standardization of technology. This has been particularly difficult to date, as companies have been taking different approaches in their R&D efforts. He refers to projects that BMW has carried out, like IDAM for metal 3D printing and Polyline for plastic 3D printing. “Standardized interfaces are an essential prerequisite for scalability so that systems from different manufacturers can be used and integrated in an automobile production environment. With our completed publicly funded projects we have, together with our partners, created the conditions for series production in the automotive environment,” Ertel states.
Scouting for plastic
One of the potential avenues for addressing challenges is the development of materials. Like many other companies, BMW has been exploring the use of advanced polymers and has already adopted them for specific components in series production. In the Mini John Cooper Works GP model, the decorative panel on the dashboard is made of thermoplastic and designed to be lightweight and hardwearing. The window guide rail on the i8 Roadster is also made with a polyamide thermoplastic.
But instead of delving into the benefits of using advanced polymers, Ertel highlights the fact that each component in a vehicle plays a different role, and as such, the material must be selected based on usage requirements. “Depending on the field of application, we use a wide variety of materials,” he explains. “In the area of prototype construction, we primarily use materials that reflect the properties of the later series components as closely as possible to enable realistic and mature validation. So, depending on future real-world applications, advanced polymers can be useful.”
Asked if advanced polymers could be used in more areas of the vehicle, Ertel does not discount the idea but emphasizes the need for further research. “Due to the high demands on our vehicles and the constant implementation of innovations, the demands on the materials used are also increasing. Our advanced development team scouts worldwide for new, innovative technologies and materials that will benefit us in the automotive sector,” he states.
Test your metal
Although polymers are currently being used in its vehicles, BMW remains dedicated to testing new processes at its Additive Manufacturing Campus, some of which could expand the material portfolio. It has recently been trialing wire arc additive manufacturing (WAAM), which consists of melting aluminum or a similar metal using an arc and layering the welded seams on top of each other to create a component. This works particularly well for large parts that require strength and rigidity while also ensuring they are lightweight, such as suspension strut supports or areas of the chassis.
“The high degree of freedom of the technology allows complex and weight-optimized geometries to be produced,” Ertel notes. “This means that less material and less energy is used in production, as the parts are manufactured very quickly. The lower weight of the components also reduces the weight of our vehicles and thus their energy requirements.”
Looking further ahead, Ertel is excited for the future of AM in automotive. “There are new designs, new structures, and new solutions being made with AM every single day,” he explains. “We are pushing boundaries with almost no limits in design, and are creating new customer experiences that would not be possible to implement conventionally. We are creating the future.”
This article first appeared in VoxelMatters’ Polymer AM Focus 2024 eBook. Read or download the full eBook for free here.
