Smart craftsmanship

As an employee carefully runs her gloved hand over the exterior paintwork of the fully electric Audi e-tron GT quattro, her gaze follows the movement. The vehicle is illuminated with a special light. Eagle-eyed Audi experts would immediately spot any imperfections during the rigorous quality control process. Paintwork, joints and gaps are put under the microscope one final time. It’s a last chance to make fine adjustments. Once the Audi e-tron GT quattrocar has passed through this final station — the finishing check — it’s ready to leave the Böllinger Höfe premises.

Before getting to this point, production models pass through numerous stations. The Böllinger Höfe plant at the Audi site in Neckarsulm employs innovative, purpose-built technologies to manufacture the fully electric gran turismo. The finishing touches are always done by hand. Wolfgang Schanz, head of production at Audi Böllinger Höfe, explains, “Producing the Audi e-tron GT quattro—and its body in particular—is a highly automated process. Nevertheless, handiwork is part of every assembly line cycle. The truth is that building a car still calls for craftsmanship. Our colleagues perform this work with great attention to detail.” Experience is another key factor. “We’ve carried over all the handicraft skills built up in manufacturing the Audi R8. What’s more, the same passion our employees invested in building the Audi R8 is now being poured into the Audi e-tron GT quattro. Right from the concept phase, the Böllinger Höfe plant was designed as a small-series production facility with innovative and flexible production processes,” says the production manager. Ideal conditions for manufacturing the Audi e-tron GT quattro. 

In order to accommodate vehicle production for both models at one location, the flexible small-series facility was upgraded and expanded. While retaining the strengths of the Neckarsulm-based Audi facility, integrating the Audi e-tron GT quattro has entailed adding new areas of expertise relating to electrification, automation and digitalization.

It goes without saying that striving to produce high-quality, precision-engineered vehicles is a top priority at Böllinger Höfe. Every process and every flick of the wrist is performed to this end. The body shop is just one example of the perfectly symbiotic relationship between craftsmanship and cutting-edge technology. A number of different joining methods, ranging from resistance spot welding through screws to rivets and bonding, come into play here. At the heart of the shop is a large clamping and attachment system, known as the two-way framer.

“A framer is used to add large assembly groups to the body, ultimately defining its geometry. Traditionally, two such framers, set up as successive assembly lines, are necessary for body construction. At Böllinger Höfe, we have succeeded in combining these steps into a single station that each car body passes through twice. That’s why it has been dubbed the two-way framer,” explains Christoph Steinbauer, head of the body shop. “On the first pass, the inner side panels are attached; the outer ones on the second. Ten robots with 32 tools are on the job, completing the steps required to join the panels to the car body. They automatically switch tools between the two passes and even during the work steps.”  

Another new station is dedicated to correlation-free measuring. Two robot-guided optical measuring heads check the exact dimensional accuracy of the body. In investigating each car body, they check 350 measuring points. At each point, a blue stripe pattern is simultaneously created and scanned, before the robotic arm proceeds to the next one. In this way, they work systematically from one spot to the next. Room cameras detect and constantly compare the exact location of the measuring heads. By generating volumes of ultra-precise data, this process makes it possible to respond rapidly to even the tiniest deviation. In addition to high-tech systems, the body assembly line includes two manual stations. Here, machines pass the baton to humans who weld with great precision by hand. The employees at this station benefit from the experience gained working on the Audi R8. Welders who have spent years crafting the sports car with a V10 combustion engine entirely by hand are now performing high-precision fusion welds, for instance, on the Audi e-tron GT quattro.

After the body assembly line, the car-in-progress moves on to the mounting stage. Body manufacturers mount the car’s fenders, doors, as well as the engine hood and tailgate. This step entails focusing on achieving precise, uniform gap dimensions and high-quality surfaces. Even minimal tolerances on the outer skin parts can result in deviations. This is why the job not only calls for meticulous care and attention but also is best achieved through a return to traditional craftsmanship. A trained carpenter, for instance, who has a keen eye and feel for surfaces, is part of the team. After the mounting stage is completed, the bodies are painted.