Newly developed machine tools are nowadays, almost invariably, equipped with a CNC control (Computerized Numerical Control).
Computer-assisted control technology enables production to be considerably streamlined compared with previous conventional systems, because the movements of the axes and tools are much faster and yet very precise. An important requirement here is the accurate measurement of the tools before their deployment in the CNC machine. For this purpose, EZset GmbH & Co. KG in Freiberg, Germany, has developed the EZset400 and EZset600 tool presetters.
In these presetters, the tools are accurately measured, tested for tolerances and adjusted before they are inserted in the CNC machine. Apart from their high measuring accuracy, both units are noted for their simple operation, compact form and ergonomic design. They owe these properties not least to the use of the Baydur® 60 and Baydur® 110 polyurethane systems from Bayer MaterialScience. It was primarily because of the much greater design freedom of these materials that the manufacturer Emaform AG based in the Swiss town of Gontenschwil decided to use polyurethane instead of metal to manufacture the housings of the presetters. Because of its many years of experience with polyurethane moldings, Emaform was able to offer EZset a moderately priced housing that is also significantly more attractive than the former metal ones.
"With Baydur®, we can manufacture the housings quickly and inexpensively, which gives us a good cost-benefit ratio," says Peter Hunke, plant manager at EZset. "Apart from that, we were impressed by the high level of design freedom that allowed us to produce a three-dimensional form as we wanted it." The material also has good slip properties, an important requirement for quiet operation. Significant wall thickness differences were specified for the two-part electronic front, which is why the Emaform development team chose the versatile polyurethane, Baydur® 60. It is ideal for designing complex part geometries with variable wall thicknesses, and thanks to its sandwich structure, combines high stiffness with low weight.
Large-area molded parts, each of which consist of two sections, are used for the housings of the X and Z axes. The ideal material for this was the microcellular RIM material, Baydur® 110, which guarantees high stiffness and strength even with thin walls, and also offers excellent surface quality for sophisticated coating systems. The brass thread inserts are molded in during production.
"We were able to solve the problem of the massive undercuts in the housing of the X axis with an innovative design concept," explains Jürg Fischer, Managing Director of Emaform. "The use of an aluminum tool makes for particularly economical production. The same is true of the short and long versions of the housing for the Z axis, for which we use a combination tool."