Active aerodynamics, functional integration and an attractive design – multi-objective optimisation with 3D printing

• What was needed: Active rear wing system
• Manufacturing process: Selective laser sintering with SLS powder
• Requirements: Complex component, low coefficient of friction, low weight, reduced design time and costs
• Material: iglidur® i3
• Industry: Automotive industry
• Success through cooperation: High time savings, reduced costs, highly complex component structure can be produced in one piece

The application at a glance:
The "WING3D" concept of the OptiAMix research project is a rear wing system that enables active aerodynamics through 3D printing. Among other things, the rear wings produced using conventional methods did not offer the option of integrating a hydraulic system into their mount. The interaction of different materials, such as aluminium and tribologically optimised iglidur® plastic, offers the system an innovative mode of operation in the adjustment of the rear wing with simultaneously increased abrasion resistance.

The EDAG Group's OptiAMix research project with igus® GmbH sought to build an adjustable rear spoiler that adapts its position to the car's driving dynamics depending on the situation. The active adjustment of the rear spoiler requires the components to be wear-resistant and have a low coefficient of friction. A robust material was required, which at the same time offers enough space in its design for the integrated hydraulics. Using conventional manufacturing processes, it was almost impossible to realise the highly complex lightweight components required for this, as the planning and production of these components is too time-consuming and costly.

With 3D printing, it is possible to design and print each individual component in such a way that it is both fully functional and visually appealing. At the same time, a wide variety of materials can be used, enabling customised printing of the lightweight components. By using 3D-printed plain bearings made of iglidur® i3, a tribologically optimised igus® plastic, the rear wing system can be operated with significantly less friction and maintenance-free than with a normal plastic. Compared to conventional materials for laser sintering, the high-performance polymer has up to 30 times better abrasion resistance and is the perfect material for adjusting the rear wing. In contrast to manufacturing processes such as milling or injection moulding, the complex inner areas of the component could be implemented quickly and easily in a single piece using 3D printing.

3D-printed plain bearings were used for the rear wing system. The great advantage of the process is the rapid printing of the highly complex components, which cannot be realised so easily using conventional manufacturing processes. The special shape and the complicated interior can be produced in just one piece using additive manufacturing. This reduces costs and ensures efficient production. In the active rear wing system in particular, it is important to enable low-friction adjustment. At igus® GmbH from Cologne, specially developed iglidur® i3 plastic is processed in 3D printing to produce plain bearings that are both wear-resistant and low-friction. The self-lubricating components are also maintenance-free and therefore ideally suited for the actively adjustable rear wing.

A bionic aluminium holder for the rear wing with integrated hydraulics was produced. This is realised by the movement of a piston using oil pressure of up to 90 bar, which enables the angle of attack to be adjusted continuously from 6° to 42°. With the help of an electric cable built into the bracket for the sensor to determine the position or angle of the wing, it actively adapts to the driving situation. A braking function is also provided, which is supplemented by an integrated LED brake light in the holder. In addition, 3D-printed plain bearings were used to reduce friction. All components created using additive manufacturing are precisely adapted to the respective other components without having to sacrifice function or visual aesthetics - a true interaction of form and function that is raised to a new design level through 3D printing.

The iglidur® i3 material has been specially developed for laser sintering and has up to 30 times better abrasion resistance than conventional SLS materials. Fine lubricants integrated in the plastic optimise the sliding properties of the components, which promises a particularly high service life in a wide range of applications. With iglidur® i3, the active system has found the perfect high-performance polymer to combine form and function. The self-lubricating components from the additive process enable low-friction and maintenance-free adjustment at the bearing points of the rear wing. This ensures a long service life for the system that would not be possible with other plastics at this point.