Optimization of Error-of-Roundness in Turning Processes

Abstract

Majority of the machined workpieces which are round and symmetrical in shape have the ratio of length to diameter normally less than three and they are overhung clamped and machined with three Jaw chucks. In such turning processes, a deviation of shape called out-of-roundness is commonly observed and its magnitude is dependent upon the workpiece specifications and cutting as well as clamping conditions. An attempt has been made here to optimise the error-of-roundness to achieve the maximum metal removal rate with the desired accuracy satisfying all the constraints of clamping and cutting conditions and workpiece specifications. A mathematical model interrelating all the important above mentioned parameters for determining the conditions for the desired error-of-roundness has been developed. The objective is to maximise the metal removal rate and to minimise the error-of-roundness maintaining it within a permissible limit. Furthermore, a microcomputer based optimisation program has been developed which will enable a lathe operator to arrive at optimum conditions to achieve a desired level of dimensional accuracy with maximum productivity. © 1986 CIRP.