Investigation of Retention Knob Geometry on Machining Dynamics

In this study, impact testing is used to determine the potential effects of retention knob design on tool-holder-spindle-machine assembly dynamics. Three different knob designs are selected and used to clamp a simple geometry artifact in a CAT-40 interface spindle. The mean and standard deviation repeatability limits are compared for frequency response functions measured using the three designs. It is shown that the knob geometry does not exhibit a significant influence on the assembly dynamics.