Tool Path Generation for CNC Milling Based on STL File

Abstract

This paper proposes and develops algorithms to read (STL) files and extract engineering entities required in CNC milling processes. The proposed algorithms are dependent on some mathematical modeling and manipulations of the engineering models by slicing an (STL) file to many slices and then building the required algorithms to adopt these slices to generate machining paths for CNC milling machines as (G-Codes). The proposed system is divided into three parts, in the first part, an algorithm proposed to extract engineering object entities to some proposed models based on their (STL) files using Matlab program. The proposed models include cube, cylinder, dome, cone and cavity models. In the second part, a slicing algorithm is proposed to enable the slices along the proposed models z-axis to find and navigate the required manufacturing data. UGS program was used also to generate the tool paths and to simulate the machining process and then generate NC part program of the proposed objects (G-Code). Finally, the third part of this work includes comparing results produced based on both (STL) and (UGS), to achieve the required aim of this paper by experimentally comparing objects surface roughness, resulted values show that the maximum difference in average R a is equal to (0.27µm).