A Generalized Approach to the Replication of Cylindrical Bodies With Compound Curvature

Abstract

A generalized method of surface definition and replication for cylindrical type objects of compound curvature is presented. The interactive approach is suited to mini-computer installations used in conjunction with standard three-axis NC machines. The compound curvature surface is defined by a new form of central perspective shadow moire contourography called pericontourography. The resulting digital data are treated in such a way that a quasi-helical cutter path is generated which may be applied directly to an NC milling machine (mill turning) or an NC lathe. Specifying the surface in terms of the subsequent machining process avoids the use of complex surface fitting and reformating routines. Interference with the spherical ended tool and the object surface is automatically tested and corrections to the cutter path are made.