Alfred H. Schütte GmbH in Cologne manufacture multi-spindle automatic lathes and 5-axis CNC grinding machines. Lathes are primarily used in the automotive and fittings industry. The grinding machines are mainly used to manufacture or process cutting tools in medical technology.
Complex and highly accurate parts are manufactured with Schütte products. This applies to the lathes dedicated to turn, bore and mill housings and shafts for injection systems, brakes or steering mechanisms, as well as the grinding machines used to manufacture a variety of items including micro-tools with diameter tolerances of 1µm. The machine precision required is primarily achieved through the high production accuracy of the relevant machine parts. Changes and investments in mechanical in-house production and increased flexibility, total manufacture and a reduction of machining times required new measuring methods and equipment that are flexible, fast, precise and reliable.
Schütte decided on a Prismo navigator S-ACC precision measuring machine from Carl Zeiss . Through design modifications, it was possible to increase its already high accuracy (MPEE up to 0.9µm + L/400). The user-friendly and flexible use of CALYPSO measuring software from Carl Zeiss permits faster measurements.
Due to high accuracy of the measuring machines, even slightest vibrations and temperature influences can affect the measuring result. Special conditions are prevalent at the Schütte factory. In addition to the company’s own production, vibrations caused, in particular, by ship traffic and the nearby railways interfere with the measurements. In order to keep these influences as minor as possible, the new climate-controlled measuring lab (20° C ± 1° C) on natural soil was equipped with a decoupled foundation. This enabled placement of the easy-to-reach measuring lab near production.
Customer acceptance Testing: Customer acceptance testing was another factor in the decision to invest in new measuring technology. Increasing requirements on the accuracy of the multi-spindle and grinding machines also led to additional demands on the measuring equipment.
PRISMO navigator S-ACC enables better monitoring of the accuracy of the sample parts and test equipment and documenting with informative measurement logs.
Highly accurate production components: Many of the parts integrated into the machine are manufactured by Schütte. Various measuring and testing equipment is used to monitor the quality of workpieces on an ongoing basis in the production process. However, with increasing complexity, parts are removed and measured on the CMM during cutting. This enables early detection and correction of negative trends. The last process is the final check of all relevant parts on the measuring machine. The accuracy and reliability of the Schütte machines are ensured by the precision components in the basic structure of the machines. Therefore, test equipment is needed that can combine high precision with high measuring speed. This enables the operators to keep downtimes during initial sample testing to a minimum. These objectives are achieved with the PRISMO navigator S-ACC. The test times for precision measurements were reduced by up to 90% shortly after machine startup. This is a decisive improvement over the previous test times.
Polygon measurement: Polygons are an element of the machine design important to the precision and stability of Schütte machines. Polygon contours are used for positive shaft hub joint connections. Polygon gages are also used for the shopfloor testing of polygons. However, it must be possible to verify and monitor their accuracy. A key criterion for the measuring machine from Carl Zeiss was the realisation of polygon measurements (DIN 32 711, DIN 32 712) with CALYPSO software. During a development partnership, Schütte delivered the specific math. Carl Zeiss integrated the functionality as part of PCM programming in CALYPSO. These PCM routines in CALYPSO enable a reduction of the inspection times per polygon from several hours to about 15 minutes.
The logical design of CALYPSO enabled quick training of the machine operators. The flexibility of measuring all features in one setting and faster than before simplifies the work considerably. Schütte plan to upgrade an older Zeiss measuring machine with UMESS 300 to work with CALYPSO.
Schütte have installed a webcam in the measuring lab to efficiently deploy their personnel. If a CNC measurement is underway, the operator can monitor the process from another workstation away from the machine.