A Study on Rapid Reverse Engineering of Castings

―Generation of Beautified Solid Models with Surface Properties Based on the Separation of Casting and Machining Surfaces―

Abstract

The purpose of our research is to establish a new RE (Reverse Engineering) method which efficiently generates easy-to-use solid models from scanned data of casting. The resulting models have properties of various types of surfaces and are beautified, which means the machining surfaces are aligned, for downstream applications such as duplication with machining and redesign. The proposed RE method is based on the separation of casting and machining surfaces in order to realize efficient RE process. The method consists of four processes. First, the surfaces of the scanned mesh are separated into casting and machining surfaces by existing roughness estimation method. Then, screw threads, through holes, and rotational small features are recognized from the separated machining surfaces. Next, beautification is done to make machining planes and cylinders parallel, orthogonal, co-planar, and co-axial using estimated dominant axes. Finally, beautified solid models with surface properties of castings are generated using Boolean operation of solid models generated from each surface. In thi s paper, methods for second, third and final process are newly proposed, and their performances are shown through the experiments. The effectiveness of the proposed RE method is also confirmed by comparison of RE time by our method with the one by skilled worker.