INVESTIGATED AN ALGORITHM OF CIRCULAR INTERPOLATION FOR CNC-MILLING OPERATION

Abstract

In this research an algorithm to generate NC tool path had been developed for machining sculptured surfaces depending on the preparation functions (G02, G03) which are special type of circular interpolation and compare it with the other paths of the linear interpolation that generated using (G01) function from package program. In the design stage Bezier technique had been used to represent the proposed surface. Mathematical equations to estimate (radius of curvature, normal vector of the curve, cutter contact & cutter location points) had been driven to generate a tool path and get the (G-code).The MATLAB program had been utilized so as to facilitate the process of calculation. In addition, four types of tool path strategies had been selected based on linear interpolation using (UGS) program which are {Zig, Zig-Zag, Zig in (w) and Zig- Zag in (w) direction}. A comparison between G-code type of circular interpolation and G-code type of linear interpolation had been done for each type of selected tool path strategies with the original data of the proposed design form. A practical aspect side had been implemented using 3-axis vertical CNC milling machine for eight specimens which are divided into two groups: four specimens for the G-code that generated using the proposed method and the others for the G-code generated using the (UGS) program. The proposed algorithm had been implemented and the results showed that the specimen of the type Zig in (w) direction that generated depended on circular interpolation gave closer to the original surface results, compared it to linear interpolation of the path type Zig-Zag in (w) that generated using UGS program.