Error compensation in machine tools - a review Part II: thermal errors

One of the major errors in machine tools namely geometric/kinematic errors was discussed at length in Part I of this paper. Mere, in Part II, another major source of inaccuracy, namely thermal error that occurs due to extende d usage of the machine is analysed. Continuous usage of a machine cool caus es heat generation at the moving elements and this heat causes expansion of the various structural elements of the machine tool. It is this expansion of the structural linkages of the machine that leads to inaccuracy in the p ositioning of the tool. Such errors are called thermal errors and constitut e a significant portion of the total error in a machine tool. Thus the over all volumetric error of a machine tool is not only dependent on errors due to the assembly and the specific kinematic structure of the machine but als o on the thermal errors. Ln Part II of this paper, an attempt is made to re view the work carried out over the last decade in the estimation and compen sation of temperature dependent errors. (C) 2000 Elsevier Science Ltd. All rights reserved.