With the current closed loop manufacturing trend, aka Industry 4.0, the Coordinate Measuring Machine (CMM) has developed a new role offering production inspection adjacent to the machine tool or production process. The CMM remains the most accurate and flexible automatic measuring device capable of delivering to the required accuracy and repeatability providing consistent production gauging results.
The use of a CMM as a production inspection tool probably represents the only global growth sector for the coordinate measuring machine industry with the erosion of its many traditional applications by the numerous optical scanning solutions entering the market.
Taking the CMM out of the quality laboratory and closer to the point of production is nothing new; however CMM designs have changed with specific products now available for the arduous application. Walking around the international Control Expo in Stuttgart this week it is evident that almost every CMM manufacturer is focused on serving its customer needs on the shop-floor and “open for production inspection”.
True ‘shop-hardened’ CMM designs have exchanged air-bearings for mechanical bearing linear guide-ways with the mechanical structures manufactured from cast-iron, polymer concrete or granite to minimize thermal impact on the device. A small footprint is also in evidence for shop-floor CMMs and interestingly most suppliers have adopted the cantilever design principle that is “open for production” allowing for easy automation integration or operator access to the measuring zone.
The 5.5.5 measuring volume (500 x 500 x 500 mm) is most common measuring volume and capable of measuring 70% plus of all manufactured parts. Mitutoyo is the latest manufacturer to offer a cantilever design production CMM with the launch of its MiSTAR 555 unit.
With integral probe changer, optionally available, and able to use both touch-trigger and tactile scanning probes production CMMs offer similar metrological performance to the traditional air-bearing lab CMM. While temperature variation remains the enemy of accurate CMM measurements most CMM manufacturers are specifying measuring inaccuracies at different temperature bandwidths to accommodate the varying installation environments that a production CMM find themselves subjected too, clearly exhibiting an ability to be “open for production inspection” regardless of customer specific requirements.
Hexagon showcased its Tiga production CMM being ‘Cobot’ loaded demonstrating the simplicity of adding automation for production integration’. LED lighting installed on the machine cover adds an immediate visual feedback indication of inspected part status.
Wenzel exhibited its recently introduced SF87 cantilever design machine, initially showcased at last years event, and offering a huge measuring volume of 800 x 700 x 700 mm while retaining a compact footprint compared to a traditional bridge CMM of the same measuring volume. In addition Wenzel has announced the introduction of a smaller SF55 model.
As evidenced from the plethora of production CMMs on display at Control from Aberlink, Hexagon, Mitutoyo, Wenzel and Zeiss the industry is focused on ensuring a critical, and ongoing, front-line production inspection role, on the shop-floor, for the coordinate measuring machine. Any rumors or report of its extinction are premature; CMMs are most definitely “open for production inspection”.