Cutter selection for 5-axis milling of sculptured surfaces based on accessibility analysis

Abstract

Cutter selection is an important issue in process planning for 5-axis milling of sculptured surfaces. To select the optimal cutter (from a set of available ones) to machine a given sculptured surface, it is essential to check whether a cutter is able to finish the entire surface without any interference. It is, therefore, necessary to check the accessibility of a cutter at any point on the surface. In this paper, the issues involved in cutter accessibility checking at a point are studied and corresponding checking methods have been developed. A search algorithm has been developed that is able to find the accessible posture range for a given cutter in terms of the tilting and rotational angles. The constraints considered in cutter accessibility analysis include the machine's axis limit, local-gouging, rear-gouging, and global-collision. This point-based solution is then extended to cover the whole surface by discretising the surface. In order to reduce the heavy computation in the checking procedure for the whole surface, the surface is decomposed into interference-prone and interference-free regions before cutter accessibility analysis by considering the local surface geometry and the cutter's geometry. The cutter considered is a cylindrical cutter with a fillet-end. Examples are given to show the validity, efficacy and robustness of the developed methods.

Keywords:

• Cutter selection
• Fillet-end cutter
• Local and rear-gouging
• Global-collision
• Accessible posture range

Acknowledgements

The work reported in this paper has been supported by ASTAR of Singapore under the project R265-000-176-305.