• dynamic accuracy
• stiffness
• performance evaluation method
• geometric accuracy
• micro-milling

This report belongs to the research project “Reliable micro-milling of dies and moulds” of Delft University of Technology, NL, which regards the development of a reliable process of micro-milling for the industrial production of dies and moulds for injection moulding. The thesis-work has been made abroad in The Netherlands. Purpose of the work was to develop a performance evaluation method suitable for the micro-milling machine present at the university.
The first step of the work was to draft, over the literature survey, the error budget for the micro-milling machine. Then it has been developed the analysis of three performances: the static stiffness of the machine components, the dynamic accuracy and the geometric accuracy. For each of them an experimental setup has been designed and some tests have been carried out.
As regards the static stiffness analysis, an investigation of the stiffness of each component of the machine has been done, modelling them in a compliance chain.
In the analysis of the dynamic accuracy some tests on the behaviour of the machine under high acceleration magnitude have been done: it has been observed the following error – the difference between the CNC controller command position and the feedback encoder actual position reading – as a function of the acceleration magnitude.
Finally it has been developed a test to evaluate the geometric accuracy of the stages, focusing on the straightness error – perpendicular deviation at the work point relative to a reference straight line - of the axis, in order to make a double check of the results obtained from previous tests.
Some recommendations are given in the end of the report to improve the performances of the micro-machine and to help future work