Geometric accuracy of CNC machine tools

The present article is dedicated to the identification and interpretation of geometric errors of CNC machine tools. Identification of geometric errors plays a large role in the construction of the so-called “Error maps”. These maps can be used to describe the behaviour of the machine in the workspace without load or under conditions of finishing operations. Interpreting the error maps represents a tool to check the state of the machine for the user and to offer the important information for the machine manufacturer. From this information it is possible to identify “weak” points of the machine. Simultaneously, the information on the geometrical errors is used to compensate for machine tools. When constructing the maps, a selection of the measuring device and ambient conditions plays an important role. The paper focuses on the use of measuring equipment LaserTRACER and construction of the error map for the workspace of horizontal three-axis milling machine. It also describes the options of how to monitor the workspace of the machine and their mutual evaluation.