A Study on the Surface Roughness in Taper Turning with Numerically Controlled Lathe

Surface roughness in turning is decided by controllable factors as the tool geometry and feed, uncontrollable phenomena as the presence of built-up edge, variation of relative position on tool-work and change of tool shape. On the other hand, in case of surface roughness in numerically controlled turning, the movement of tool which is driven by pulse motor becomes one of the important factors. This paper describes the analysis and experiments of surface roughness in optional taper turning by NC lathe with respect to the controllable factors. The results are that the theoretical area of surface roughness R is shown as follows; fa2/8r≤R≤r+1/2{bmax-fa√4r2/fa2+bmax2-1}. The experimental results approximately agree with the theoretical area of surface roughness.