KGM 181 grid encoders

The KGM grid encoders dynamically tests the contouring accuracy of CNC-controlled machine tools. It can perform, for example, circular interpolation tests with radii ranging from 115 mm down to 1 ?m at feed rates up to 80 m/min. The KGM can also perform free-form tests in two axes. The advantages of the KGM include its contact-free measurement, which eliminates the influence of ball bearings such as with the DBB. Also, the error resulting from the machine's geometry has no influence on the results of circular interpolation tests with very small radii.Measuring assembly and signal evaluation The KGM consists of a grid plate with a waffle-type graduation, which is embedded in a mounting base, and a scanning head. During measurement, the scanning head moves over the grid plate without making mechanical contact. For setup, the mounting base is fixed onto the workpiece-holding element (such as the table of a machining center) and aligned. The scanning head is mounted in the locked toolholding element (for example, the spindle of a machining center) and is also approximately aligned. A spacer foil is used to set the scanning gap to 0.5