Part localization theory and its application on near-net-shape machining

As an emerging technique, near-net-shape machining implies that billets of a part are near to its net shape (or its design), and thus, little machining of the billets is required to produce qualified pieces. This technique has been employed in production of critical parts, repair of important but worn out parts, and machining of three-dimensional (3-D) printed parts. To cut a near-net-shape billet, its part localization should be conducted by transforming (or localizing) its part design model geometrically such that the transformed model is inside the billet and within the part tolerances. This transformed model is called machining model. After that, the machining model is used to generate tool paths and the billet is cut with the tool along the paths. Unfortunately, the current problem of this technique is that the conventional part localization methods cannot ensure that the transformed model is within the tolerance and tool paths generated with this model cannot be used to cut the billet for a qualified piece. To address this problem, an innovative and practical approach is proposed to transform part features individually, making sure that the transformed model is inside the billet model and satisfies the part tolerance. In this work, three practical examples are rendered to verify this approach. This approach lays a theoretical foundation of part localization and is an effective solution to near-net-shape machining in industry.