The use of CGTech’s Vericut NC simulation software can achieve considerable cost savings in production, as it helps to detect potential faults or problems prior to the actual production process. Components produced by MT Aerospace for the space industry show exactly how well the software works. Here, tanks for the Ariane rockets are manufactured with floors that have to be spherically milled to save weight.

MT Aerospace AG is based in Augsburg, Germany and provides around 10 per cent of the hardware on the Ariane 5, making it the largest supplier for this rocket programme outside of France. The company develops and produces key components and sub-systems for the Ariane – for instance, large structures, booster housings and light-weight construction tanks. For its component manufacturing operations MT Aerospace puts its trust in Vericut’s NC simulation software.

Predominantly the company develops and produces large, lightweight structures. Low density metals such as aluminium and titanium, as well as bonded materials are used here, and their production is characterised by special engineering processes. These include press cylinders, spin forming, complex welding methods and additive manufacturing processes for creating fibre composites.

Optimised, high precision production of these components is not just a must due to the high aerodynamic, thermal and mechanical loads placed on the components within the Ariane rocket. “The actual materials and tools form a large part of the component costs, so zero-error quality is required before producing prototypes and test parts,” explains Peter Zotz, Head of NC Programming at MT Aerospace in Augsburg. To achieve this goal the production department has been working with CGTech’s Vericut simulation software for over a decade to ensure the quality of the NC program, especially for milled parts of the Ariane 5.

As the software simulates NC production (turning, drilling, milling, wire-cut EDM, radial milling) it detect errors in the NC code before the first actual machine run. This is done independently of machine, control system and CAM package. The software, works both with G code and with CAM system outputs. Vericut’s main functions are simulation of material removal with verification and analysis, and optimisation of milling feeds of the NC program.

Peter Zotz says: “Errors are detected with extreme precision. These errors can be displayed in a selected colour, clicking on the error highlights the appropriate NC record. All errors are stored in a log file. And, the program can also be run in batch mode and can be set to take graphical snapshots of all errors.”

The system uses the appropriate CNC control logic to exactly match each controller and can be simulated to adjust to the various machines, programs, workpieces and functions. No special programming language is required.

What motivated MT Aerospace to introduce Vericut NC verification software was machine and component safety, which is understandable when you consider the extremely long run times and the very expensive raw materials. Peter Zotz says: “For example, the inner dome highlights the problems associated with a possible collision or a crash using a ‘trial-and-error’ production method. This hemispherical component is an integral part of the ESC LH2 tank structure developed by MT Aerospace. It has 4000 pockets which have to be milled and, due to the required surface quality of the components, the machining time for each part is around 600 hours.”

Unverified working methods, where the programmer checks through the extensive NC code list before the machining process begins, would be completely unacceptable. Using this method the consequences of a crashed machine tool ‘worst-case’ scenario would include the costs of repair, replacement of raw material and machine down time, a high scrap yield and failed delivery times or penalties for non-performance. At MT Aerospace, there has not been a single collision since introducing Vericut software – and the running-in phases of the program have also been reduced. The software also helps to optimise cycle times and production planning as well as to determine overall scheduling times.

New acquisitions within the CNC machine area at MT Aerospace were also a driving force in introducing this simulation solution. The implementation of High Speed 5-axis machining techniques at the end of the nineties also increased the danger of collision between the tool and the part as well as between the tool and the machine’s components. Today, the complex components are produced at MT Aerospace on 5-axis machining centres from Forest Liné, Fooke, Huron, Rottler and Carnaghi.

Thanks to the use of Vericut NC simulation software, programs can be checked for collisions and errors before the machines are run. Manual testing is no longer required. And, the software allows milling  feeds from the NC program to be optimised in such a way that production is not only more efficient but also more sympathetic to the machine tool. For MT Aerospace this software has long proven its usefulness during prismatic machining, and its use for turned components is being planned.

About MT Aerospace

MT Aerospace AG is a supplier to the aerospace and defence industries as well as a partner for antenna and mechatronic systems. Within its aerospace segment, MT Aerospace develops and produces components and subsystems not only for rocket launchers but also for satellites and orbit transfer systems.

The corresponding Operation and Maintenance business sector at Kourou in French Guyana is in charge of integration and start systems, as well as additional tasks, for Ariane 5. The company is responsible for, and co-ordinates, construction of the start systems for the Sojus launcher rocket in Kourou. MT Aerospace has an eight per cent share in the European Ariane marketing corporation, Arianespace, within the framework of a European consortium on parts of the floor system.