Alternate methods for sampling in coordinate metrology

Abstract

A variety of inspection equipment exists in industry to capture the points on a surface that will envisage manufacturing form errors. Manufacturing inspection faces a problem of finding optimal methods to capture an evenly spread distribution of points on the surface. Sampling does not yield complete information about a surface. Each material removal process leaves a unique pattern on the surface of the workpiece, which has to be taken into consideration while developing the sampling strategy. For instance, round patterns left by face milling at low feeds on flat surfaces, and spiral patterns left during surface milling and turning operations on surfaces of revolution. Two new methods have been developed to improve sampling using the coordinate measuring machine (CMM) for inspection of flat and revolved surfaces. These are the Spiral, and Hamspi sampling methods.