Computer-aided mold engraving: from point-data smoothing, NC machining, to accuracy checking

Abstract

Abstract With the aim of computerizing the engraving process of industrial molds, this paper proposes an integral approach comprising three modules: smoothing noisy data points, generating NC engraving codes for both the rough and fine cuts and examining geometric deviation. Techniques of reverse engineering are applied where the surface of the original mold is first scanned to acquire 3D data points, followed by using the ‘minimum energy’ concept to filter unwanted data points, in order to obtain smooth point-data. Methodologies founded on the smoothed data are then proposed to automate the generation of zig-zag cutter paths for the rough and fine cuts while keeping off any gouge during engraving. Next, algorithms are established for deviation analysis, providing a norm to analyze the margin of error between the original mold and its final completion.