On the simulation of roundness profiles obtained by turning

Quality of mechanical components is more and more often related to geometric tolerances, e.g., roundness, flatness.. parallelism runout and position. Usually. geometric tolerances are checked using a Coordinate Measuring Machine (CMM), which samples a set of points on a surface. and then, using appropriate fitting algorithms,. estimates a tolerance. hi planning die CMM based inspection of a mechanical component feature. cleverness may, be added with the definition of an empirical model representing the measured surface (or profile). In this paper. two empirical models of roundness profile obtained by turning are described. Such models allow foreseeing the "signature" left by the turning process. By using such roundness models, the ami of the present paper is to exploit computer simulation in order to estimate the relationship between the out-of-roundness; of turned items and two factors: 1) the number of measurement points taken, 2) die fitting algorithm implemented. The widest used techniques of geometric best fitting, i.e. least square and minimum zone methods, have been implemented. in this work in order to estimate the out-of-roundness value for each simulated profile