Modeling and measurement of geometric error of machine tools : Methodology and implementation

Abstract: One of the main performance criteria for a machine tool is its ability to manufacture dimensionally and geometrically accurate parts. In this context evaluation of the geometric and kinematic accuracy of machine tools is important for achieving a high accuracy of machine parts. Moreover, the potential of predicting the accuracy of the machine tool outcome would benefit by reducing the non-value adding operations of machined parts measurement. The aim of this thesis is to develop a methodology for modeling geometric errors of machine tools in order to evaluate the geometric and kinematic accuracy and estimate the machined part accuracy by predicting the error motion of the machine tool for a given toolpath. The thesis consists of the description of the methodology that includes and explains aspects necessary for the development of the machine geometric error model. Additionally, a laser interferometer measurement process of the geometric errors and the various parameters necessary for the model development is presented. A three axis machine tool is utilized in order to investigate and analyze the model and to measure the geometric errors. An analysis is made for evaluating the accuracy of the machine tool. Finally, a computational implementation of the model is made and two simple toolpaths are generated in order to demonstrate the potential of the model in predicting the geometric errors of the machine.