PECM Issue 37 2019 | Page 142

MACHINING & MACHINERY CLAMPING TECHNOLOGY SCHUNK POLYGONAL CLAMPING DELIVERS RESULTS IN TURNING APPLICATIONS For years, customers have been using TRIBOS polygonal clamping technology to achieve excellent results in applications such as micro cutting and to lower tool costs. With TRIBOS ER, SCHUNK is now bringing the patented technology of polygonal tool clamping to sliding and fixed headstock lathes and rotary transfer machines. Pilot users, such as Zisterer Präzisionsdrehteile GmbH in Villingen- Schwenningen, Germany, are impressed. The company has reduced machining time in demanding milling applications by one third while significantly improving surface quality.   There are good reasons why SCHUNK is now unlocking the potential of polygonal clamping technology for lathe chuck technology. For one, the requirements for sliding headstock 142 PECM Issue 37 lathes are constantly growing. At the same time, customers are facing considerable pressure to lower prices, particularly for high-volume parts. For Zisterer Präzisionsteile GmbH in Villingen-Schwenningen, SCHUNK’s decision to standardise the TRIBOS ER came just in time. The manufacturer of complex hydraulic components was regularly experiencing process disruptions due to tool breakages as tools with a long overhang and cutting diameters of 2mm could not withstand the vibrations that occur. Halving the speed was the only way to ensure the process stability required for high-volume production. Instead of 12,000 to 15,000 RPM, the company had to accept speeds of 6,000 RPM and the resulting reduction in cycle time.   MACHINING TIME REDUCED BY A THIRD   “Until now, our maximum speed was 6,000 RPM,” explains Uwe Walikewitz, Head of CNC longitudinal turning at Zisterer. Everything beyond that would inevitably lead to tool breakage, unless the company had switched to expensive special tools with reinforced shanks. “The TRIBOS system saved us around 200 seconds at a total machining time of just below 600 seconds,” says the machining specialist. “The rotational speed was only reduced by 500 to 1,000 RPM as compared to the recommended cutting parameters, and lo and behold, it worked perfectly.”