Perfect machining results due to 1:1 simulation on the PC

　　With the DMG MORI Virtual Machine, Airbus Defence and Space increases process reliability and manufacturing quality on a DMC 125 FD duoBLOCK®

　　Established from the previous EADS in 2014, Airbus Defence and Space is responsible for the areas of defence and space as a subsidiary of the Airbus Group. With headquarters in Ottobrunn, Germany, the company focuses amongst others on the development and construction of engines for the Ariane 5 launch vehicle. Airbus Defence and Space meets the high demands on quality with long-standing experience in machining and state-of-the-art CNC technology. Among recent acquisitions are two DMU 70 eVo linear machines and one DMC 125 FD duoBLOCK®. The company also uses the DMG MORI machines as 1:1 image on the PC in the form of the DMG MORI Virtual Machine. The software can be used in a preliminary PC simulation to safely check the complex machining of the highly expensive workpieces. This makes manufacturing completely safe and enables process optimizations already at a preliminary stage to increase efficiency in machining.

　　A fully loaded Airbus A380, which is approx. 590 tons, launches with a thrust of around 1,200 KN. These figures are just provided here to convey some idea of what it means to send an Ariane 5 launch vehicle weighing 775 tons into orbit – admittedly vertically – with almost 12,000 kN thrust. The latest version of the European launch system has been launched regularly and above all completely reliably from the Space Centre Kourou in French Guiana since 2005. This reliability is crucial, as the Ariane 5 always carries expensive cargo like geostationary satellites, unmanned cargo crafts for the ISS or comet probes like Rosetta. A launch failure would often be synonymous with financial losses running into billions.

　　Airbus Defence and Space GmbH is crucially involved in the development and construction of Ariane 5. The main engine as well as the upper stage are manufactured in Ottobrunn, as well as other components for the aerospace industry. What all applications have in common is the uncompromising quality. “The value of the blanks alone can run up to several thousand Euro”, says Wolfgang Simon, head of mechanical production, with regard to the pure material value of some components. In view of such figures, the same rule in production applies as it presumably does in Kourou: “The first shot must be a winner.”

　　Top level machining

　　The range of materials includes aluminium as well as titanium, but also high-strength stainless steels and nickel-based alloys like Inconel, probably one of the most complex materials at Airbus Defence and Space. “The interaction of stability and weight is crucial here”, says Wolfgang Simon. Every additional kilo costs a lot of money at the launch. So it is understandable that every gram counts for the complex components. The production manager gives an example: “If we are at the upper limit within the tolerance range and not at the lower, this might already be too much.” Naturally he is speaking of hundredths, not tenths of millimetres.

　　The high demands placed on precision and complexity are only one part of the challenge in manufacturing, as Wolfgang Simon explains: “Competition is extremely high, which means that we must produce as cost-effectively as possible and above all adhere to deadlines.” What is ideal is a balanced ratio between quality, costs and adherence to schedules. Airbus Defence and Space ensures the specialist know-how required for this with consistent training and induction of junior employees. On production technology side, the company regularly invests in state-of the art machine tool technology, most recently in three machining centres from DMG MORI: two DMU 70 eVo linear machines and one DMC 125 FD duoBLOCK®. Furthermore, the DMG MORI Virtual Machine was acquired for all three, to further optimize manufacturing processes and quality. With this software, DMG MORI enables exact simulation of machining on the PC, in an exact 1:1 image of the real machines.

　　“The high quality standard in production requires machine tools that consistently work precisely”, says Wolfgang Simon when explaining the decision for DMG MORI. Versatility is another factor: “The 5-axis simultaneous machining and milling-turning technology enables applications that could otherwise never be resolved economically.” In order to gain additional process reliability and optimize production, Airbus Defence and Space relies on an extensive simulation of the NC programs for complex manufacturing tasks. “After all, we need to guarantee collision-free production of the expensive components”, says Wolfgang Simon and adds: “When an NC program is installed on the machine, it has to work.” A suitable simulation software was found with the DMG MORI Virtual Machine, as it already produces a very realistic simulation of the programs on the PC in the preliminary stage.

　　Virtual machine including geometry, kinematics and control

　　Airbus Defence and Space currently makes great advances in production with the DMG MORI Virtual Machine. The software is able to display the DMG MORI machine tools one-to-one on the computer, including the actual machine geometry and kinematics as well as the original control and the real PLC. Gerhard Engelhardt, who is responsible for NC programming, sees enormous benefits in this virtual solution: “We can exactly simulate machining of the expensive components completely safely on the PC, and check the program for general machining feasibility or possible collisions.” Gerhard Engelhardt also uses simulation of the CAM software, but: “We still simulate the final NC code on the DMG MORI Virtual Machine to achieve optimum process reliability.”

　　A measuring probe is also integrated in simulation, which performs real-time measurements like on the real machines. The measured results are also acknowledged in the virtual machine. “Accuracy here is sufficiently high, so that we can already see on the PC whether machining meets our expectations”, says Gerhard Engelhardt. Another feature of the DMG MORI Virtual Machine is shop floor programming. As the actual Siemens control software forms the basis, users can also take full advantage of the ShopMill functionality. This also enables further optimization of the programs based on the simulation, increasing the quality of the finished parts in turn.

　　The process reliability is an important aspect for Wolfgang Simon, also from the operators' perspective: “For particularly sophisticated components, you can first of all familiarize yourself with the machining on the virtual machine before working on the valuable workpiece.” New skilled personnel can also be trained in this virtual environment. “Production is much more relaxed for each operator when he can rely on the process already having been tested.”

　　In addition to process reliability and enhanced quality, Wolfgang Simon as head of mechanical production also regards the complete production processes as advantage of the DMG MORI Virtual Machine: “We can organize and accelerate our processes completely differently.” On the one hand, we already know exact machining times in the preliminary stage, on the other, verification of the programs on the PC is much faster than on the machine. “Furthermore, the lengthy running in of programs can largely be omitted, and setup times are minimized.” Consequently, significantly higher machine running times can be realized and productivity can be markedly increased.

　　Continuous modernization of production with innovative solutions like the DMG MORI Virtual Machine has a high priority for Airbus Defence and Space. Wolfgang Simon expects the complexity of products and their quality requirements to increase further. The cost pressure is also expected to grow independent of this. So the production manager sees this very clearly: “We can only stay competitive if we not only develop the products that we manufacture further, but also ourselves and our production. A crucial step in this direction is the use of the DMG MORI Virtual Machine.”

　　Captions

　　Figure 1

　　Wolfgang Simon (right), Head of Mechanical Production, and Gerhard Engelhardt, responsible for NC manufacturing

　　Picture series 2, 3 and 4

　　Airbus Defence and Space also uses the DMC 125 FD duoBLOCK® as DMG MORI Virtual Machine. The software simulates the complete machine geometry and kinematics as well as the actual Siemens control

　　Picture 5