CAD/CAM Integration for NURBS Path Interpolation on PC Based Real-Time Numerical Control

As anybody knows, there is a fundamental difference between the newest CAD system and the conventional Numerical Control. As a matter of fact, almost every CAD Software allows programmers to use parametric 2D or 3D curves, whereas standard Numerical Control cannot perform anything more than linear or circular interpolations. NURBS are the most successful among all the proposed parametric curves, since they allow us to give an exact uniform expression to both the analytical and the free form curves. Nevertheless, this typical characteristic nowadays entails that in CAM systems a tool path is rounded down using a small movements and imposing a maximum acceptable gap. This approach leads up to a number of problems of machining quality and wastes machining time. In this paper the authors propose a software able to automatically generate, from a CAD geometric model, instructions for a Numerical Control running on a common Personal Computer.