The measurement of parasitic forces in orthogonal cutting

Not all the forces measured during a cutting operation contribute to chip formation. Some fraction of the forces an parasitic forces such as ploughing or flank forces, which make no contribution to the chip formation process. It is desirable to measure these forces so that the mechanics of the cutting process can be interpreted correctly. However, a possibly more important reason is that parasitic forces are known to increase with worn tools. Thus if the parasitic force can be measured directly, or extracted from the overall measured forces it may be useful for in-process tool condition monitoring provided appropriate calibration of the relationship between the parasitic force and cutting tool dullness has been performed. A method for measuring the parasitic forces in orthogonal cutting is proposed and shown to permit calculating workpiece material properties which are consistent with those measured using other techniques. Another technique for evaluating parasitic forces which was previously shown to yield inaccurate results for zinc was re-evaluated for Delrin(R) and again resulted in incorrect results. (C) 1997 Elsevier Science Ltd.