Flexible production: Printing parts from digital data
Large format additive manufacturing has become an integral part of BMW Group’s production system, according to Timo Göbel, head of additive manufacturing. Elsewhere, CEAD is localising production with its Flexbot platform
Large format additive manufacturing (LFAM) is enabling vehicle manufacturers and automotive suppliers to make parts, moulds and tools more quickly and with greater flexibility. That is important as manufacturers face increasing pressure to reduce lead times, cut material waste and make their supply chains stronger. The automated 3D printing of bigger parts using high-flow pellet extrusion also enables manufacturers to produce large, complex components directly from digital designs closer to the point of assembly, which lowers development, production and transport costs.
LFAM serves as a meaningful complement within the production system, broadening the application spectrum of additive manufacturing technologies across the entire product lifecycle
BMW Group is one carmaker that has been increasing its use of additive manufacturing across various applications, including for lightweight precision parts, rapid prototyping and customisation, as well as in more general production in combination with traditional manufacturing. In terms of LFAM, BMW is using it across multiple applications, from rapid prototyping to manufacturing jigs and the production of specialised parts and components.
Evolution of 3D printing
According to Timo Göbel, head of additive manufacturing at BMW Group, the key gain is greater agility, scalability and efficiency in production. He says 3D printing has evolved from a prototyping technology into an integral part of the BMW Group production system and used throughout the entire vehicle lifecycle, including series production and aftersales applications.
“We actively pursue an open-technology approach and evaluate different additive manufacturing processes depending on the specific application,” says Göbel. “For larger-format applications, we are using robotic systems both for metal parts based on Wire Arc Additive Manufacturing (WAAM) and polymer parts based on Fused Granulate Fabrication (FGF).”
Increasingly, BMW is using those technologies for production equipment, handling systems and robot grippers. Successful examples can be found in BMW’s German plants in Munich, Landshut and Regensburg, where large, lightweight and highly customised gripper solutions have been developed and deployed in series production environments.
"At the same time, we are preparing the use of those technologies for small scale series manufacturing of components for our vehicles,” adds Göbel. “We will start series production of the first components using WAAM in 2027.”
Fast and flexible production
One of the key strengths of additive manufacturing is its ability to significantly shorten development and implementation cycles, with the associated cost savings. Parts can often be produced directly from digital data without having to manufacture dedicated tooling first. Göbel says this enables much faster validation loops and enables the rapid implementation of production-related solutions.
For production equipment and plant-specific applications, the technology enables BMW to come up with cost-efficient, customised parts much faster than conventional sourcing. LFAM, in particular, makes a significant contribution to reducing lead times in manufacturing. At times rapid and cost-efficient production of large components needs additional finishing to achieve the precision required of automotive parts. That final stage can be carried with established production technologies, thereby combining the strengths of each to deliver high-quality, application-specific parts.
“LFAM serves as a meaningful complement within the production system, broadening the application spectrum of additive manufacturing technologies across the entire product lifecycle,” says Göbel.
LFAM also enables teams to react quickly to changing production requirements because the parts are produced directly from digital models. That way, modifications can be implemented without redesigning or manufacturing new tooling.
“In our production system, this has enabled a wide range of customised solutions, from handling equipment to manufacturing aids, supporting our goal of maintaining a highly flexible and responsive production network,” says Göbel.
Flexibility is achieved by replacing conventional manufacturing methods such as injection moulding or machining in many use cases. Additive manufacturing enables faster, more localised access to production support equipment and components, helping plants implement improvements with greater speed and precision.
The BMW Group is also investing in more automated and digitally connected additive manufacturing process chains, which will further support industrial scalability in the future, according to Göbel. “Compared to powder bed-based technologies, WAAM and FGF offer higher productivity and thereby higher production capacity,” he says. “They also afford design adaptability and rapid implementation of changes. In, addition, processes such as FGF offer greater material choice and application versatility.”
Material benefits for BMW
In terms of LFAM, the benefit for BMW is the production of significantly larger components than many conventional additive manufacturing processes. The technology can consolidate multiple parts into a single component, minimising joining interfaces and potential weak points. In addition, Göbel says that polymer-based LFAM, such as FGF, can use standardised injection-moulding pellets as feedstock, providing additional flexibility in material sourcing and potentially improving cost efficiency.
“Compared to our powder bed-based additive manufacturing technologies, the LFAM-technologies use standard materials that are already well established within the BMW Group production network,” says Göbel. “These can be purchased at lower cost and are available in high quality.”
FGF is a well-established area of research and pre-development within BMW Group’s Additive Manufacturing Campus, including doctoral and academic research projects and several BMW Group locations are engaged in FGF-related activities. Significant expertise has been built up in areas such as material processability, process optimisation, design and engineering, and build strategies.
The standard materials are also already familiar to colleagues outside the additive manufacturing community, which helps accelerate qualification and industrial implementation.
Another benefit of LFAM materials at production grade is that BMW can make prototypes that more closely replicate the mechanical and thermal characteristics of series-production parts. “Combined with comparatively affordable equipment and feedstock materials, this enhances the overall cost-effectiveness of the technology and opens up additional application areas across industrial manufacturing,” notes Göbel.
Flexbot for LFAM
On the supplier side of the business, CEAD is a pioneer in the LFAM space and its modular, industrial-scale manufacturing platform Flexbot is built around high-payload robotic arms supplied by robotics maker and system integrator, Comau. Flexbot can carry out large-scale printing and milling within a single automated cell. CEAD says this enables continuous material flow, precise multi-axis motion and integrated finishing operations. The platform delivers the precision, repeatability and scalability needed to use LFAM for industrial automotive manufacturing.
“Flexbot is built around a configurable robotic platform that can be adapted to different production requirements and can be scaled up or down as needed,” says CEAD’s marketing lead, Doris Logtenberg. “The system can also be replicated across multiple sites that deliver the same manufacturing process and quality.”
This removes the need to ship large tools or finished parts from a central facility. Manufacturers can simply send validated digital files to a local or regional Flexbot cell and in doing so, localise production.
“This in turn helps reduce lead times, improve responsiveness to local demand and make production less dependent on long supply chains,” says Logtenberg. “The same modular approach allows companies to start with a standalone cell and add capabilities, such as CNC milling or other functions, as demand increases.”
From a logistics perspective the technology helps reduce transport costs, cuts lead times, minimises inventory requirements and helps eliminate potential logistics issues. It also enables companies to incrementally increase production capacity, saving upfront investment expenditures, without sacrificing manufacturing responsiveness.
Cutting lead times, lowering costs
Producing moulds and tools directly from digital files enables a radical shift for the automotive industry, according to Alessandro Piscioneri, Comau’s head of product and solution management. He says it can significantly reduce lead times from weeks to days and can lower upfront investment costs. “Furthermore, digital design makes late-stage changes less costly than they would be with traditional methods,” he adds. “This is especially relevant when tooling needs to change often, volumes are limited, or programmes require faster validation before committing to hard tooling.”
The technology lends itself to decentralised (or distributed) manufacturing across smaller, geographically dispersed microfactories, enabling parts to made closer to where they are needed. Robot-driven microfactories can be configured around the specific needs of the sector being served, according to Logtenberg.
“The automotive aftermarket is a natural example for LFAM,” she says. “There is a clear place for on-demand production of the moulds and tooling used to make replacement, repair, and low-run or obsolete parts, where the need is to make one or a few, close to where they are used.”
Digital design makes late-stage changes less costly than they would be with traditional methods… especially relevant when tooling needs to change often, volumes are limited, or programmes require faster validation
Good examples include bumpers, bonnets, wings, splitters, diffusers and spoilers.
Designs armed to repeat
For most projects, digital design is led by the customer’s engineering team and that team works with CEAD’s application and customer success specialists as needed.
Unlike the centralised production and dedicated tooling common in traditional manufacturing, LFAM allows manufacturers to send validated digital designs to production cells located where the parts are needed. Instead of transporting large tools or finished components across regions or continents, manufacturers produce what they need locally using standardised, high-quality 3D printing processes.
Comau contributes the robotic automation expertise that makes the printing out of the designs industrially repeatable. The high repeatability enabled by Comau’s robotic arm makes it for automotive parts that also require high precision.
Comau’s robotic automation also supports faster design changes, which is particularly important for prototyping, motorsport componentry and in low-volume production. The robotic cell can combine printing and milling, which means parts can be printed near-net shape and then finished without moving them to another machine.
According to Piscioneri, examples of use in the automotive sector include the carbon-fibre reinforced composite moulds used for sportscar parts, windshield pressing tools used to place PC/PET sheets into vehicle windshields and prototype parts for hydrogen-fuelled city cars and high-performance race cars. Flexbot has also been used to produce a fully 3D-printed monocoque for a CO2-neutral car.
“The choice to use LFAM to print a final component or mould typically depends on various characteristics, including the part size, material composition, production volume and lifecycle expectations among others,” says Piscioineri. “By working alongside our customers to evaluate the benefits of LFAM for their specific project, we can help them define the best route.”
Local customs
LFAM is gaining momentum wherever manufacturers need large composite structures, localised production or rapid tooling. The United States and Europe are two of the biggest markets, according to CEAD’s Logtenberg, both regions in which Comau and CEAD have a strong presence. She said that LFAM is growing in popularity because it enables manufacturers to respond faster and produce locally. It also allows them to manufacture large or highly customised components more effectively, in terms of time and costs, compared to more conventional methods.
For BMW, there is no one-size-fits all answer in deciding on whether LFAM is suitable, or in fact an advantage, for the production of a particular part or tool. The carmaker sees additive manufacturing not as a replacement for conventional production technologies, but as a complementary tool within a broader manufacturing portfolio. Each application is assessed individually, with decisions guided by the value the technology can deliver in practice.
According to Göbel, BMW takes an open-technology approach, continuously exploring new materials, processes and industrial applications. “The determining factor is always whether additive manufacturing offers a tangible benefit for a given use case,” he says, “whether in terms of cost, sustainability, lead times, flexibility or overall manufacturing efficiency.”
