Spiral Tool Path Generation for CNC Machining Using Cloud of Points

This paper presents a new method to generate an adaptive spiral tool path for 3-axis CNC machining of the complex freeform surface directly from its representation in the form of the point cloud. The algorithm first constructs the uniform 2D circular mesh-grid to compute the Z (CL) points by applying the tool inverse offset method (IOM). Adaptive grid refinement is carried out iteratively until the surface form errors converge below the prescribed tolerance limits in both circumferential (forward) and radial (step) directions. Adaptive CL points are further refined to minimize the no. of tool lifts and generate an optimum sequence of machining regions. The optimized CL points are post-processed to generate the final CNC part programs in the ISO format. The part programs generated by our algorithm were extensively tested for various case studies using the commercial CNC simulator. The results were compared with those from the commercial CAM software. Our system was found to generate more efficient tool paths in terms of enhanced productivity, part quality, and reduced memory requirement.