Towards deflection prediction and compensation in machining of low-rigidity parts

Abstract

Producing the right profile in machining low-rigidity complex parts increasingly depends on specialized computer aided manufacture (CAM) packages for defining appropriate cutting strategies and tool paths. Despite the significant developments in numerically controlled (NC) simulation and verification there are still gaps between the theoretically predicted surfaces and the measured surfaces owing to a relatively small percentage of machining error types that could be detected and interpreted by the existing software systems. This paper reports on a new methodology for simulation and prediction of the deflection of thin wall parts during machining. It aims to increase the understanding of the causes of poor geometric accuracy by considering the impact of the machining forces on the deflection of thin-walled structures. The proposed approach is based on identifying and modelling key processing characteristics that influence part deflection, modelling the material removal process using ‘voxels’ and predicting and correcting the deflection of the parts. The reported work is part of ongoing research on developing an adaptive machining planning environment for modelling, prediction and selection of process and tool path parameters for rapid machining of complex low-rigidity high-accuracy parts.