Comparison of Parametrically Programmed Machining with CAM System Machining for C0 Continuity Bezier Curves Based on Various Parameters

Abstract

Parametric representation has become a standard form in product design, graphics design, computer-aided geometric design as well as machining. Stamping, forging and extrusion dies and tools, rolling shapes, turbine blade profile, air craft and automobile body, ship hull, etc is designed in CAD and uses parametric curves to define the shapes. Past few decades have witnessed formulations of many novel mathematical representations of free form curves aspiring to make them more computers compatible. Parameterization of a curve have availed some important advantages of being bounded in parameter range, independent of coordinate system over implicit representation as well as part family and coding in Group Technology (GT). Parametric programming also referred to as macro programming being a critical feature in GT and Computer Aided Process Planning (CAPP) is a powerful but less explored feature of the CNC technology. Machining using parametric programming is judged against the CAM system for program length, machining time and accuracy through Coordinate Measuring Machine results. Few Bezier curve profiles have been constructed, by joining of which gives tangent continuity throughout the curve for the purpose of machining and their CNC and Parametric programs have been discussed. The results found for the same geometry, work material and cutting parameters are discussed in the paper in detail.