Measurement point selection and compensation of geometric error of NC machine tools

The selection of the measurement point is one of the key steps in modelling. The traditional closed-loop control method can enhance the machine tool precision to a certain extent; however, there are some limitations in this technique. This paper presents a method that simplifies modelling a geometric error by integrating the Abbe and Bryan principles. It is found that the modelling accuracy directly affects the machining accuracy, and that the manufacturing process and effect can be simulated using VERICUT. The machining simulation of a hemispherical workpiece provides a theoretical basis for error compensation. A compensation module is integrated into a CNC system, and the effectiveness of error compensation is verified by applying the double ball bar method. The measuring results before and after error compensation are compared, demonstrating that the errors are reduced and compensated successfully.