Porsche invests in aluminium finishing machinery in its Schwarzenberg manufacturing facility

Porsche has introduced a larger machining facility at its newly acquired plant in Schwarzenberg, Germany, to accomplish better finishing in its aluminium car body manufacturing.

The company, upon realising that a premium finish in the silvery-white light material cannot be achieved with traditional steel parts production machinery, has collaborated with Starrag for the purchase.

"For some years, we have been experiencing a shift towards lightweight construction and, as the Porsche competence centre for forming technology in the moulding skin area, we were commissioned to develop the tools required for the conversion to an aluminium body," Marco Franz, head of mechanical production, explains.

"During forming, aluminium sheets respond much more sensitively than steel," Porshe officials realised, "We found our existing machines were not able to meet the requirements."

The Schwarzenberg plant has used the investment to set up two new production halls, purchase a new 25,000kN servo press for production-related tool try-outs and invest in retrofitting and new machine tools – including two Starrag HSC centres of the Droop+Rein FOGS 35 68 N40C type.

Two large Starrag High-Speed Cutting (HSC) machinery centres, Droop+Rein FOGS (5-axis machining centre with an overhead gantry and a traverse paths of 6.8m x 3.5m x 1.5m along the X, Y and Z-axes), play a major part in this. The machines produce press tools for moulding skin parts of automobile bodies with the utmost precision and produce surfaces of grinding quality.

The equipment contains a tool magazine with 100 places that can be filled with HSK32, HSK63, and SK50 retainers. It also includes an eccentric fork head with a 40kW milling spindle and an elevated torque of 700Nm and three distinct motor milling spindles with speeds of 18,000, 40,000, and 65,000 rpm. 

Additionally, one of the two machines has a special 6,000rpm angular head that Mr Franz ordered. It can be used for machining areas that are difficult to access.

"With this range of spindles, requirements in the coming years are covered," Mr Kramer asserts.

The change came post the brand's decision to transition from KUKA, who were previously in charge of the plant's operation.

Mr Kramer explains, "We didn't just want to buy a machine, we wanted a solution for our tool manufacturing process. That is one of the main reasons why Starrag seemed to be the right partner. With the Droop+Rein specialists, we had the impression right from the start that they were listening to us, wanted to understand us and the thinking behind our processes, and wanted to use their expertise to help us."

The machining facility comes with preconditionary requirement such as process stability, availability and ease of maintenance, as well as characteristics that could not be compromised, such as temperature stability. In addition, future-orientated specifications for the performance data of the spindles were required. 

"When you buy this kind of machine, you expect to use it for the next 10 to 20 years," Lutz Kramer, head of tool and mould making, comments. "During this time, several generations of new milling tools have been developed that are more efficient and allow higher speeds, so we had to take all of this into account at the early tendering process."

With the brand's requirement set, the central decision makers understood that not many manufacturers would be able to meet the requested standards. 

"During the technical discussions that we held with many different machine tool providers, we were soon able to tell who was able and willing to overcome the challenges. Some machines withdrew at an early stage; others were later unable to offer any acceptable solutions," stated Mr Kramer.

Once the machine installation was completed, the two companies commenced to figure out the workflow jointly, considering the characteristics of CAM, the control system, and the machine. A high level of accuracy on the path, even at the highest feed speeds, is a mandate to achieve the best surface quality.

According to the official website, more than 300,000 Porsche cars were sold in 2023.