Development of a tool life prediction model for plaster machining

Abstract

This paper reviews the developments of the ongoing research at the Staffordshire University into the application of Computer Numerical Control (CNC) machining techniques to produce plaster moulds and prototypes. The experimental work was carried out on plaster using conventional cutting tools (slot-mills), using a six-axis anthropomorphic robot. Based on the tool wear (Flank Wear ? VB) measurements, an analysis of the cutting tool failure was undertaken. This work had comprised of three phases. Initially, an experimental screening was carried out in order to identify the major important criteria regarding the cutting tool wear problem. The second phase corresponded to the development of a tool life prediction model for the machining of the plaster material. The calculations were carried out using the response surface methodology and the 23 factorial design. The experimental results showed that the cutting speed is the most significant factor to the tool wear process. Finally, results developed from a theoretical analysis with the tool life prediction model were compared with the experimental results. This test demonstrates the validity of the theoretical analysis and showed how the optimisation process can be performed using this methodology.