High Precision, High Security, High Reliability

For a designer and builder of aircraft, precision machining of aluminum components is among the first and most important considerations
Pilatus Aircraft Ltd. is a Swiss manufacturer of turboprop and jet aircraft for niche applications, particularly STOL (short takeoff and landing) aircraft as well as military training aircraft. Its PC-12 single-engine turboprop aircraft was its first developed for the civilian aircraft market (passenger and cargo service), and its PC-24 twin-engine business jet is expected to make its debut in the coming months.

Last year Pilatus Aircraft installed new manufacturing systems for machining structural aluminum parts. In order to achieve its desired surface quality and precision during high-speed milling, the manufacturer works with a selection of Haimer GmbH toolholders and corresponding shrinking and balancing machines.

For Pilatus, as for many operations machining parts for aircraft structures, the precision of the operation is critically important to the operating performance, as well as to the reliability of the finished parts. It invested in a completely modernized volume-machining system in order to extend the quality standards and efficiency of its operation. Two core elements of that investment are the flexible manufacturing systems that are fully automated, helping to guarantee high quality as ell as stability.

"Only the high balancing grade of the complete tool assembly, balanced on a Haimer balancing machine, together with Haimer toolholders can guarantee vibration-free machining and surfaces without any chatter marks,” according to Walter Duss, director of milling operations. “Furthermore, the high run-out accuracy significantly increases the lifetime of the spindle and tools."

Patrik Odermatt, the Pilatus mechanical processing team leader, commented that experience shows high-quality toolholders offer long-term stability and run-out accuracy are worth the investment cost. It’s for that reason that he has worked with Haimer products.

He uses Haimer shrink-fit chucks and high-precision collet chucks together with the corresponding presetting, shrinking, and balancing machines that are available at the Pilatus tool shop, which serves as the OEM’s internal tool management service center.

"Regarding such topics as quality, price-performance ratio, consultation and support, our experience with Haimer is very positive," Odermatt explained. "That's why we made the decision to continuously and solely rely on toolholding technology from Haimer when it comes to our new manufacturing system. We exclusively use tools that are clamped into Haimer standard shrink-fit chucks, ultra-short and long power shrink chucks as well as power mini shrink chucks, power collet chucks and special face mill arbors.”

Since Pilatus is working with many different parts that are extremely thin, with wall thicknesses ≤1.2 mm and deep pockets, the wide range of Haimer toolholders was an important consideration. Also Haimer provides flexibility regarding the spindle interface: for the new manufacturing systems a special HSK-A 63/80 toolholder was necessary. After close cooperation with Pilatus, Haimer developed a program for this interface and added it to its standard delivery portfolio.

Haimer also offers innovation resources, in particular its patent pending mechanical locking Data-Lock system, which fixes the RIFD data carrier onto the toolholder. Pilatus uses this technology to ensure that even at the highest RPMs the data carriers are securely fixed and cannot separate from the toolholder.

According to Odermatt, one of the advantages of working with Haimer is sourcing all its toolholding technology from a single source. “For every Haimer shrink-fit chuck, the required parameters are already integrated into the shrinking machines,” he observed. “The performance and heating time are ideal and guarantee process-reliable shrinking at the push of a button. And balancing is also easy to perform.”