Author : Hacene Ameddah, Kamel Zidani and Rabah Manaa

The research work reported in this paper focuses on introduces a fully STEP-compliant CNC by putting forward an interpolation algorithm for Non Uniform Rational Basic spline (NURBS) curve system for rough milling tool paths with an aim to solve the problems faced by the current CNC systems. The most important components used in aerospace, ships, and automobiles are designed with free form surfaces. An impeller is one of the most important components that are difficult to machine because of its twisted blades. The research is based on the premise that a STEP-NC program can document “generic” manufacturing information for an impeller. This way, a STEP-NC program can be made machine-independent and has an advantage over the conventional G-code based NC program that is always generated for a specific CNC machine. Rough machining is recognized as the most crucial procedure influencing machining efficiency and is critical for the finishing process. A key feature of the system is the use of STEP-NC data model (ISO 14649-10: 2003; ISO 10303-238, 238: 2003), which enables more design information (e.g. geometry, workpiece information and tolerances) to be incorporated both prior to and during machining processes. The relevant algorithm for the curve was simulated in CAM software. The results have shown that the algorithm for rough milling is feasible and effective.

Keywords: Tool path, STEP-NC, Impeller, Rough machining, NURBS interpolation

Article published in International Journal of Current Engineering and Technology, Vol.6, No.1 (Feb-2016)