"INCREASING THE POSITIONING ACCURACY OF THE FEED KINEMATIC LINKAGES OF CNC MACHINE TOOLS THROUGH THE CALIBRATION METHOD "

Abstract

The accuracy of a CNC machine tool is one of the most important parameters that make the geometry and dimensions of the work pieces comply with the tolerance limits specified through the designer’s technical drawing. When a machine tool is handed over to the customer it is compliant in terms of the accuracy limits specified in the documentation but, after a time interval of usage, because of the wear of the components in relative motion and machine exploitation conditions. This work suggests an innovating method of testing the accuracy of a CNC machine tool by using the “calliper”, with a view to enhancing the positioning accuracy of the feed kinematic linkages. After designing and manufacturing this device, the measurement of the target points on the coordinate measuring machine is necessary, so that this device becomes a “calliper”. For inspecting the machine tool, the “calliper” is located on the machine table, being measured at the target points by means of the probe with the tactile shooter that belongs to the machine. The measurement results are stored and compared to the results of the measurements performed through the coordinate measuring machine. In function of the two measurements the related corrections of the errors will be done in the software of machine tool numerical control.