Heidenhain develops static and dynamic accuracy testing for machine tools

Citation

(1999), "Heidenhain develops static and dynamic accuracy testing for machine tools", Sensor Review, Vol. 19 No. 2. https://doi.org/10.1108/sr.1999.08719baf.012

Heidenhain develops static and dynamic accuracy testing for machine tools

Heidenhain develops static and dynamic accuracy testing for machine tools

Keyword Calibration

A new measuring system able to determine the dynamic and static positioning accuracy, repeatability and guideway error within the linear axes of a machine tool by distinguishing individual factors contributing to errors, has been developed by Heidenhain for acceptance testing, inspection and calibration of machine tools and measuring equipment (see Plate 10).

Plate 10 The VM 182 comparator system is accurate to ±1 micron in the longitudinal direction and ±1.5 microns in a transverse direction

Now available from Heidenhain GB of Burgess Hill in West Sussex, the VM 182 comparator system is accurate to +1 micron in the longitudinal direction and ±1.5 microns in a transverse direction. It can be used for machines and equipment with linear traverse distances up to 1,520mm while covering lateral movements of +1mm.

The system comprises a high accuracy graduated steel scale using a two co-ordinate phase grid and a noncontact scanning head located on an auxiliary carriage. The scale is clamped paraxially to the machine table and the scanning head connected to the quill of the machine using a magnet. The auxiliary carriage is then removed and the unit is ready for operation.

Linear and non-linear error curves as well as reversal error, positioning accuracy and repeatability are then measured as the machine slide is moved to certain positions. From the measurements a motion trace error is then developed using comparator techniques. While measuring positional accuracy, VM 182 will also determine any guideway error perpendicular to the traverse direction of the machine slide.

By incorporating a Heidenhain ND 281V Display Unit, the incremental measuring signals with a signal period of 4 microns in both axes can be evaluated. These are shown in measuring steps between one micron and 0.005 microns and, through RS-232 connection, data can be sent to a PC for further processing. However, when used with one of Heidenhain's TNC contouring control systems, error compensation values can be downloaded directly to the control.

Contact Mr Michael Laming, commercial Manager, Heidenhain (GB) Limited, 200 London Road, Burgess Hill, West Sussex, UK RH15 9RD. Tel: +44 (0)1444 247711.