Micrometer Precision

Toolmaker KWS Kölle opts for ACCURA bridge-type measuring machine from ZEISS

A single tool can make all the difference in the quality of millions of products. Toolmaker KWS Kölle is therefore a true proponent of maximum precision and measures all components with a coordinate measuring machine from ZEISS.

Challenge: precise in-house measurement

There is a brand emblem on the steering wheel of just about every car on the road. Numerous German carmakers purchase the punching tools used to make them from one and the same manufacturer: KWS Kölle in Mauerstetten, Germany. The company produces punching, bending, compound and forming tools, as well as injection molding, zinc die-cast and glass molds. Its products also include highly precise one-off parts and small series, prototypes, assemblies, fixtures and gauges. The production of all tools also major challenges for the measuring technology used. Customer demands on accuracy have increased enormously. Today, the maximum permissible errors often lie at one micrometer. KWS President Helmut Hübner describes just how precise this must be: "Just holding this workpiece in my hand causes its shape to change several micrometers due to the heat generated by my hand." Until a few years ago, KWS relied on external measuring labs to ensure the high precision, which led to delays.

Solution: measuring machine with outstanding ease of use

KWS therefore decided to buy its own measuring machine and opted for the ACCURA bridge-type measuring machine from ZEISS with a measuring range of 1200x901x900 mm. KWS chose this machine because of its precision and the possibility of using it at temperatures of over 21° Celsius directly in the air-conditioned production area. But it was its superb ease of use that was really decisive. Because the quantities at KWS are very small with between one and ten items for each product, the work needed to create the individual measuring programs had to be minimized. As a pilot customer of ZEISS, KWS additionally selected a new scanning probe for the ZEISS ACCURA. The ZEISS XTR scanning probe is integrated into a rotary axis and enables the stylus system to turn as far as possible in 15 degree increments and thus always be positioned at the right angle to the part. It reaches practically every location even with complex workpiece geometries – without sacrificing accuracy.

Benefit: one machine for everything

KWS can now use a single machine tp measure all workpieces – from complex small parts up to 500 kilogram tool designs – even radii, which required a contourograph in the past. This further increased accuracy because the results from a single measuring machine can be more easily compared. Since KWS has been using the ZEISS ACCURA, there have been fewer questions and discussions with customers about the measured values. According to Hübner, the company "now has even more responsibility because customers often no longer check our work."

About the company

KWS Kölle has been manufacturing tools for more than 30 years, including compound, punching, bending and forming tools, as well as injection molding, zinc die-cast and glass molds. Its product portfolio also includes highly precise one-off parts and small series, prototypes, assemblies, fixtures and gauges made of various materials. KWS employs 50 specialists and trainees who cover every processing step on site. The majority of the company's customers can be found in the automotive industry, as well as the medical technology, mechanical engineering, electronics, cosmetics and other segments.