The foundry industry is facing profound change. Cast products manufactured using traditional processes such as core shooting are reaching their limits in the face of increasing demands for complexity, resource efficiency and sustainability. At the same time, market changes such as the decline of combustion engines in industrialised countries and stricter environmental regulations are influencing demand. These dynamics open up opportunities for innovative technologies that offer new solutions and complement existing processes. 3D printing in core production is a key technology that can future proof foundries and, as a supplement to traditional core shooting, enables the greatest possible flexibility in core production, say Rudolf Wintgens, Dipl Ing, managing director technologies, Andreas Eisenhaber, special representative management, and Frank Wedemeyer, head of research and development, all from Laempe Mössner Sinto GmbH.
Market developments show that 3D printing offers enormous advantages as a future technology in the foundry industry. The ability to adapt to flexible and specific requirements, the reduction in production complexity and the elimination of tool management and wear make this technology particularly attractive. It also opens up possibilities for innovative geometries that cannot be realised with traditional methods. These factors motivated Laempe to rethink 3D printing from the ground up and develop it independently of existing industry solutions.
In addition, the BMW Group showed interest in Laempe becoming active in this area as part of a research project in 2016. The development project began with clearly defined goals that were formulated by the BMW Group as part of an R&D project (‘Industrialization of 3D printing’). The focus here was on requirements such as production speed, degree of automation and curing process. Laempe relied on an interdisciplinary team that worked away from established processes using agile methods such as sprint plans.
CLOSE AND INTENSIVE COLLABORATION: the focus right from the start
Technological challenges, such as high production rates and parallel process sequences, were identified in the concept phase and addressed with innovative solutions. For example, the width of the printing and application unit was optimised and individual systems were intelligently parallelised. The project also included support for organic and inorganic binder systems, with the initial focus on inorganic systems – a key component of the BMW requirements.
Close co-operation with the BMW Group was a central component of the project right from the start. Laempe was able to draw on extensive experience in core production technology, particularly in dealing with sand, binders and automated processes. This expertise was used to develop an application oriented and foundry compatible solution. The strategic goal was an open platform concept that would allow flexibility in the choice of materials and standards. This would reduce potential dependencies and offer manufacturers the opportunity to actively influence their production costs.
The BMW Group had specific requirements for the system, such as high output, minimal personnel deployment within operating times and complete maintainability by its own employees. This required robust, self regulating systems and maximum equipment of the technology. Integration into existing BMW production processes, including centralised control systems, was another key point.
The bidirectional printing technology and high printing speed were crucial to achieving the ambitious production targets. The now approved, fully automated, 3D printing line offers significant benefits, such as inline quality control, reduced set-up times and the ability to produce complex geometries efficiently. The open platform allows the BMW Group to flexibly access different materials and suppliers, while the overall concept is designed for long term sustainability.
OBJECTIVE: use of printed cores for production in the new BMW six-cylinder engine
With the development of new vehicle technologies, the requirements for cast parts and their geometries are constantly increasing. One example of this is the BMW Group’s new six-cylinder engine, whose optimised cooling channels require precise cast cores that cannot be produced using traditional methods. Among other things, water jacket combination cores are used, whose complex structures enable improved cooling, which contributes to increasing the efficiency and reducing the emissions of the engine.
The high demands on dimensional accuracy, high quantities and short production cycles posed considerable challenges. Added to this was the need to automate the entire production process end to end to mitigate the shortage of skilled workers in the foundry industry, to ensure consistent quality and to implement the 3D printing process cost effectively in large scale production. The development of a customised 3D printing system became the central task to meet these challenges. This was the starting point for the collaboration in 2016. The project began with the development of a prototype, which was brought to series production readiness in several stages.
BMW GROUP INITIATES 3D PRINTING TECHNOLOGY: from Laempe and its partners
Laempe has set new standards with the development of a fully automated 3D printing line together with the BMW Group and its partner R Scheuchl GmbH. The system, which was installed at the foundry site in Landshut, consists of six printers, two microwave stations for curing, automatic mould material preparation and return, as well as fully automatic core cleaning and final 3D measurement of the core. This complete solution enables end to end production without manual intervention.
The six 3D printers form the heart of the system. A key unique selling point is the bidirectional printing process, which enables high speeds with minimal non productive times. Four six-cylinder water jacket combination cores for the new generation of engines can be produced within twenty minutes. The printers also have a modular design and offer an open platform that guarantees flexibility in the choice of sand and binder suppliers. This reduces customer dependency and enables production costs to be optimised. The ability to support different binder technologies, including inorganic and organic binders, enables foundries to adapt the technology to different production requirements and thus realise a wide range of castings.
The six printers work with a highly modular system that is characterised by extreme robustness and practicality. The printing speed of over 800mm/second is one of the highest in the world and enables a high cycle rate even with complex core geometries. The bidirectional printing units ensure fast and even material distribution, guaranteeing continuous production quality.
A particular challenge was the development of the inline quality control, which was fully integrated into the production line. Printed layers can be checked precisely using scanners, while any deviations can be corrected in the next print. This increases efficiency and significantly reduces waste. The technology is complemented by robust mould material recirculation, which reduces material consumption and supports the sustainability of production.
INSIGHTS INTO THE COMPONENT: the water jacket core
One of the most important components of the project is the water jacket combi-core with integrated exhaust duct core, which is used in the new generation of BMW six-cylinder engines. This component is crucial for the thermal efficiency of the engine. Thanks to its optimised geometries, the temperatures in the aluminium head are effectively regulated, which improves both the performance and consumption as well as the longevity of the engine. The new engine, which is also used in the new 7 Series, is a technical masterpiece and achieves an unrivalled balance of performance, efficiency and environmental friendliness. This is achieved, among other things, by its optimised cooling channels, which are made possible by the precise cast cores from the Laempe 3D printing line. The optimised cooling technology means that the high temperatures of the exhaust gases are efficiently dissipated in the aluminium cylinder head and can be bundled in a twin-scroll turbocharger.
CUSTOMISED ADAPTATIONS AND MODULARITY
One advantage of Laempe’s 3D printing technology is its high degree of modularity. Each printing line can be customised to meet specific customer requirements, which facilitates implementation in different production environments. By working closely with Laempe, the BMW Group was able to ensure that the printers were seamlessly integrated into the existing production processes. The scalability of the system also makes it possible to fulfil future production requirements with ease. The close co-operation between Laempe and the BMW Group has not only led to the successful implementation of the current project, but has also opened up new possibilities for the further development of the technology. Regular feedback loops with the customer make it possible to identify and implement optimisation potential. As a result, the system always remains at the cutting edge of technology and offers customers a long term competitive advantage.
A special feature of Laempe systems is the high degree of digitalisation. From design to the production process through to quality control, every step is digitally recorded and monitored. This enables a high level of process reliability, and the continuous optimisation of system performance. The efficiency of production can be further increased with the help of digital twins and advanced sensors.
The development of Laempe’s own software solutions helps to simplify the operation of the systems and increase flexibility. Functions such as the automated slicing of print jobs and the integration of error correction mechanisms are crucial for smooth operation.
Laempe’s 3D printing technology is the key to solving current challenges in core manufacturing. With its modularity and automation, it offers foundries the opportunity to organise their processes in a flexible and resource saving manner. At the same time, the technology sets new standards in terms of speed, precision and efficiency. Hybrid core production, in which customers can choose between traditional and additive processes, enables customised adaptation to the respective requirements. This makes Laempe a pioneer and a reliable partner for the foundry industry on its journey into the future. The 3D printer project is also unique for Laempe itself: fifteen patent families have grown out of the development to date and more than 240,000 man-hours have gone into the development.
THE 3D PROJECT: a milestone in the transformation of the foundry industry
The project impressively demonstrates how 3D printing can revolutionise core production. With its combination of technological innovation, automation and resource saving processes, Laempe is actively shaping the transformation of the industry. The company is the only supplier to develop and operate both core shooters and 3D printers, which means that Laempe knows the cost structures of both technologies inside out. The key advantages of Laempe’s 3D printing technology as a supplement to the traditional core shooting process is summarised:
- Freedom of geometry: cast cores printed with Laempe enable complex topology – and function optimised components that cannot be produced using conventional methods. This results in optimised cooling channels that ensure more efficient heat dissipation.
- Automation: Continuous process control and automation minimise manual intervention and reduce the need for skilled labour.
- Sustainability: Resource saving use of materials through integrated mould material cycles promote environmental compatibility.
- Flexibility: Open platforms allow a free choice of suppliers and customisation to specific customer requirements.
- Cost effectiveness: The high printing speed and automation lead to a significant reduction in unit costs, which also makes the technology economically attractive for series production.
With the combination of 3D printing and traditional core shooting processes, Laempe offers foundries maximum flexibility. Customers can choose between additive or conventional processes depending on their requirements. This hybrid core production enables economical production along with adaptation to changing market requirements. The ‘pay per part’ model also creates a completely new approach for foundries that want to benefit from the technology without incurring high investment costs.
Contact: Laempe Mössner Sinto GmbH, Hintern Hecken 3, 39179 Barleben OT Meitzendorf, Germany. www.laempe.com
For a copy of the supporting images refer to the full printed version of the article in the April/May 2025 issue of Foundry Trade Journal.