Technical progress requires courage – BRIGHT proved this in a challenging project for a leading automotive manufacturer. The company implemented the innovative solution using precision micro stereolithography by Boston Micro Fabrication (BMF). Partner AM Pioneers prints high-precision connector plates for plug connectors in stable synthetic resin on a microArch S240 3D printer with 10µm resolution in Esslingen, Germany.
As a development partner for the mobility sector, BRIGHT, with locations in Böblingen and Munich (Germany), among other places, offers a wide range of products and services to support the industries standard testing processes. The innovative team of more than 100 employees is a development partner in the mobility sector – from the automotive industry, aerospace, railway technology to agricultural and construction machinery. Peter Hautke, General Manager Sales and Operations E/E, received an enquiry in 2024 regarding test equipment for the control units of a new generation of vehicles.
Checking the electronic nervous system
Control units form the intelligent nervous system of modern automobiles. They control ignition and fuel injection as well as automatic climate control, safety and driver assistance systems. The networked devices receive signals from sensors and set actuators in motion – the slightest malfunction can cause catastrophic consequences. ‘Before new vehicle models go into series production, developers and quality assurance engineers want to know exactly how the various control units actually work with the series wiring harness,’ reports Peter Hautke. To connect the measurement technology behind the control units, a Y-shaped adapter cable is inserted. BRIGHT was tasked with developing and supplying this. ‘We can buy the plug and socket between the control unit and the series cable,’ says Hautke, ‘the difficulty lies in the connectors at the junction for the measurement technology.’
The solution was to scan the conventional socket, redesign the 3D model and then 3D print it. However, the connector plate inside has to accommodate around 100 gold-coated pins with very tight shape and position tolerances – otherwise individual pins would break off. ‘Reliable 3D printing of the 18 variants required in series of 150 pieces was not possible with the required tolerances,’ says Peter Hautke. ‘But we were confident that our partner AM Pioneers could solve the problem with a new 3D printing process.´
Projection Micro Stereolithography from BMF
Since 2021, AM Pioneers GmbH in Esslingen has been supporting manufacturing companies in the implementation of various 3D printing technologies – with 3D scans, as a service provider for engineering and manufacturing, and as a reseller of printing systems. The company focuses on leading manufacturers such as Desktop Metal, 3DCeram and Boston Micro Fabrication (BMF) for microfabrication. Projection Micro Stereolithography (PμSL) by BMF improves digital light processing for micro-scale applications. The printing systems contain high-precision optics to focus the pixel size in the projector to 25μm, 10μm or 2μm, depending on the printer series. The linear technology of the 3D printers has also been designed for the lowest tolerances. AM Pioneers has owned a microArch S240 from BMF since 2023. With a resolution of 10µm and a build volume of 100 x 100 x 75 millimetres, it is suitable for prototypes and series production of microcomponents in final quality. ‘The S240 combines high accuracy and precision with the reproducibility that is crucial for our projects,’ explains Frederik Nußbaumer, Head of Sales at AM Pioneers. ‘We were confident that we could use it to print the connector plates within the specified tolerances of 20 µm.’
Proof of Concept
Now BRIGHT just had to convince the skeptical customer. Together with AM Pioneers, they took a risk and delivered free sample parts that met all requirements. By presenting the underlying technology and additional reference parts, they were able to convince the automotive manufacturer, who can now enjoy considerable advantages over conventional manufacturing methods. ‘The complete elimination of tooling costs for the injection moulding process, the time savings and the significantly greater flexibility for late changes and improvements are important factors,’ explains Peter Hautke. ‘However, the safety gains from the extensive testing of the critical control technology are even more significant.’
Efficient small series and variant production
Until the middle of next year, the partners are now permitted to produce 18 variants of the connector in small batches of 150 pieces, for a total of 2,700 components, on the 3D printer and deliver them with the cable sets. ‘We can produce 20 parts in one setup,’ reports Frederik Nußbaumer. ‘We benefit from the high process stability of the machine, which we can easily run overnight.’ HTL, a high-performance polymer from BMF that is available in various colours and also transparent, is used for this purpose. In this case, the most stable material in black was chosen. ‘The wide range of available materials, transparent, biocompatible and particularly durable resins are an important selling point for us,’ says Frederik Nußbaumer. The installation, instruction and user training were completed by BMF in four days. Since then, AM Pioneers has only occasionally needed support from the manufacturer: ‘We are very impressed with how quickly BMF responds to technical questions,’ says Frederik Nußbaumer, praising the partnership with BMF.
Conclusion
AM Pioneers uses the machines as in this project for series production, contract manufacturing of prototypes and as demonstration equipment. ‘The microArch S240 proves itself as a genuine production tool thanks to its repeatability and process stability,’ says Frederik Nußbaumer. ‘With the right expertise in engineering and additive manufacturing, it can be used to gain real competitive advantages.’ The automotive manufacturer’s first order will not be the last: various vehicle variants are still in development and will also be tested. ‘In a price-sensitive environment, we work with our developers and partners every day to find the best solutions for our customers through expertise, innovative ideas and the courage to take risks,’ concludes Peter Hautke. ‘This approach has proven highly successful in our collaboration with AM Pioneers and BMF.’
