Grinding as a Proven Technology is Accurate and Economical

Austria – For specialist tool and mould-making company Lercher Werkzeugbau of Klaus, Austria, it was the need for reliability and precision, not short processing times, that determined their choice of machinery processes. For them, grinding has tremendous advantages over EDM and hard milling.

Lercher Werkzeugbau was founded way back in 1979. Currently the company has 108 employees and an 8,500 m² facility for the production of moulds and tools for injection moulding and stamping, as well as injection-moulded thermoplastic components.

“For us, grinding has tremendous advantages over EDM and hard milling,” says tool grinder, Arno Wölbitsch. “It is a proven and mature technology. Also, we have extensive expertise and are able to choose the optimum solution even for the most difficult machining scenarios.”

 A carefully coordinated overall design for flexible application in tool and mould making: Seen here is the surface and profile grinding machine J600 from Jung. For maximum flexibility, the surface and profile grinding machine J600 offers modes for manual operation via handwheels as well as semi-automatic and automatic CNC grinding. Convex and concave contours can be quickly and very precisely dressed with the integrated swivel dressing device, which is equipped with a diamond dressing wheel and a calibration ball for the probe.

Consequently, Lercher has repeatedly invested in surface and profile grinding machinery, mostly from Jung. "These machines have always convinced us with their high stability, precision, and reliability,” explains Dominik Lercher. He and his sister Sandra are the third generation of the family to manage the business.

Lercher recently invested in the surface and profile grinding machine J600 from Jung. This machine combines the advantages of manual grinding and the characteristics of a high-quality CNC grinding machine.

The machine allows for quick and extremely reliable grinding of high-precision profiles, which is ensured through, among several other features, the integrated swivel dresser PA T130 with its diamond dressing wheel. An electronic measuring system measures and automatically corrects the diamond wheel's eccentricity. The profile on the grinding wheel (up to 50 mm wide and 30 mm deep) is produced through the interaction of the swivel axis and the NC axes of the profile grinding machine.

Shorter lead times, increased flexibility, accuracy

This dressing concept ensures a precision level of less than 5 µm in the grinding wheel profile. Also, the diamond dressing wheel achieves significantly shorter downtimes than dressers with a single diamond, so that grinding wheels can be dressed and profiled several times in a row without changing the dressing tool. This shortens lead times and increases flexibility and accuracy, particularly in the repeatable grinding of multiple identical components. Direct measurement systems with a resolution of 0.1 µm in all axes of the J600 ensure high precision on the ground workpiece, and hydrodynamic sliding guides dampen possible vibrations in the X-axis.

Machine with two electronic handwheels

The machine is equipped with two electronic handwheels, thus making it especially versatile. Classically trained tool grinders in particular prefer manual operation and would rather trust an operation via handwheels than a programmed, automated process, particularly during set-up and first approach of a workpiece.

For Dominik Lercher, the J600’s machining performance meets his high expectations, and additionally is a machine that is comfortable to operate and easy to use.