Leveraging Force

Airbus subsidiary Premium Aerotec, a developer and manufacturer of structures and manufacturing systems for civil and military aircraft, relies on CGtech’s NC Vericut and its Force module for machining efficiency. With German locations in Augsburg, Bremen, Hamburg, Nordenham, and Varel, and a Romania plant in Brasov, its aviation supplier develops and manufactures the latest in modern aircraft structures, from aluminum, titanium, and carbon fiber composites for the entire Airbus family.

The company is a key partner in the development and production of the A350 XWB, and a parts supplier for the Boeing 787 Dreamliner, Eurofighter Typhoon, and Airbus A400M heavy-lift military transport aircraft.

Premium Aerotec was established in January 2009, with the merger of the EADS plant in Augsburg with the facilities of Airbus Germany in Nordenham and Varel. Under Airbus Group’s governance, the company’s headquarters are in Augsburg, where around 4,000 people are employed. The focus is on the manufacture and assembly of fuselage parts and heavy-duty structural components for military and civil programs, with the use of hybrid lightweight structures, carbon fiber technologies, infusion processes, and sandwich construction techniques.

To guarantee the surface qualities and workpiece tolerances required, high-performance material machining techniques are employed in Premium Aerotec’s production area. These techniques must meet the defined quality required without scrap or elaborate repeat machining to rework components. They must also minimize the wear on machines and cutting tools, minimize downtime, and be highly efficient, even with complex components running in small batches. In other words, they must be fast, precise, reliable, and reproducible without compromise.

Simulation software

Many in the aerospace sector recognize that machine tool safety and security are critical to meet ongoing delivery targets. Using Vericut NC simulation software is an integral element of Premium Aerotec’s manufacturing processes. Since 1991, the fundamental aim has been to avoid machine tool collisions, either with the structural components of the machine, raw material or component, or fixturing systems.

Vericut checks the NC code that generates the milling paths on the machine tools. In 26 years of use, it has more than proved its worth.

“Today, there are no more prove-outs required on the machine. No NC program goes onto the machine without having been tested first in Vericut,” explains Werner Flagner and Michael Hoffmann, who supervise more than 30 Premium Aerotec employees who work with Vericut.

Vericut simulates the entire CNC manufacturing process, regardless of the machine, control system, or CAM system involved, and it tests the NC program for interferences and errors before anything runs on real machines. More than 25 machining centers used at Premium Aerotec are simulated using Vericut.

At the Augsburg plant, Vericut’s Auto-Diff module provides an automated identification of the differences between a CAD model and a workpiece simulated by the software. Within the module, anyone involved in the manufacturing process can detect incorrectly processed points or programming errors.

“It is an ideal tool that is particularly important when extremely expensive parts are involved, and which, when it comes to allowances and tolerances, has proved to be indispensable,” Flagner says. “Auto-Diff helps cut programming time and speeds up the entire process,” Hoffmann adds.

Machining efficiency

With material removal rates up to 98%, it is possible to reduce production times from setting up, parts handling, measuring, and run-through. Machining can speed processes in a single setting, with the integration of different manufacturing procedures. Ideally, the complete machining process takes place in one hit, reducing positioning errors or component damage during manual handling. Optimized workholding strategies and new machine tools with modern cutting tools also have the potential to increase cutting speeds, material removal volumes, and improve machining qualities, while also increasing service life. However, process safety and security remain absolute requirements in manufacturing, and that is why Premium Aerotec has applied CGTech physics-based module, Force, to increase efficiency while maintaining operational reliability.

Force, a joint software development between CGTech and United Technologies Corp. (UTC), is a Vericut module that uses known physical parameters to determine the maximum reliable feed rate for a given cutting condition, based on four factors: force on the cutter, spindle power, maximum chip thickness, and maximum allowable feed rate. It calculates ideal feed rates by analyzing tool geometry and parameters, material properties of the stock and cutting tool, detailed cutting tool edge geometry, and Vericut cut-by-cut contact conditions.

Feed optimization

Managing Director Tony Shrewsbury explains, “It relates to helix and rake angle, as well as the tool’s geometric form. What is decisive is the material type – carbide, hard metal, or HSS – and the issue of when the tool breaks. As loading peaks are also displayed in Force, these can be managed and reduced to smooth loading to make the cutting action less shocking to the tool, workpiece and elements of the machine tool.”

Force does not need any user findings; it is optimized solely based on the determined values. No elaborate software tests are required.

“The issue is not about milling strategies of existing programs. No tool path needs to be changed. Force simply divides or splits the path to introduce advances. Everything is governed by the feed advance, so the geometries are not altered,” Shrewsbury says.

Benefits

Premium Aerotec has gained right from the start with the Force solution. Machine cycle times have fallen about 22% with programs optimized by Force, with a substantial improvement in tool life. Shrewsbury is confident there are still more potential benefits to be seen in the future. “Force is extremely well-suited to materials that are difficult to machine and for complex multi-axis operations,” he says. “We are encountering both these factors increasingly, not only in the aerospace sector, but in all precision machining industries. For real-world efficiency gains, Force is the most innovative software currently available.”

CGTech
www.cgtech.com
IMTS 2018 Booth #133346

Premium Aerotech
www.premium-aerotec.com/en