Unstable vibration in centreless grinding: Part 2. Graphical method

Abstract

The authors demonstrated in a previous paper that in centreless grinding geometric instability and chatter were essentially the same phenomenon. In this paper a graphical approach developed for metal cutting is extended to centreless grinding with the aim of explaining certain earlier findings. It has been shown that the additional force components in centreless grinding allow chatter to occur at frequencies well below the natural frequency and give rise to roundness errors previously considered as geometric instability. These additional force components also explain why a flexible wheel does not improve stability in centreless grinding. Furthermore, it has been shown that the higher resultant force with centreless grinding results in a lower minimum stable width compared with conventional cylindrical grinding.