Effectiveness of continuous workpiece speed variation (CWSV) for chatter avoidance in throughfeed centerless grinding

The continuous rotation speed variation is demonstrated to be an efficient method to avoid regenerative chatter in different machining processes. This paper presents a time-domain dynamic model for throughfeed centerless grinding process that can predict chatter by means of part roundness error evolution. Continuous workpiece speed variation (CWSV) has been implemented in this model to analyze the influence of this disturbing method on the dynamic instability. Experimental results have validated the model and verified the effectiveness of CWSV for chatter avoidance and surface finish and dimensional tolerances improvement. It has been demonstrated that the selection of the optimal variation parameters is an important factor not only for chatter avoidance, but also for the stability of surface finish and dimensional tolerances since workpiece speed variation has a direct influence on throughfeed rate and grinding forces.

► A time-domain dynamic model for throughfeed centerless grinding is developed.
► CWSV decreases chatter amplitude and improves workpiece roundness and roughness.
► CWSV has a direct influence on throughfeed rate, forces and workpiece tolerances.
► It is necessary to select optimal combinations of variation amplitude and frequency.
► There is a trend towards selection of low frequencies and large amplitudes.