Experimental validation of chatter stability for variable helix milling tools

The occurrence of self-excited vibrations during machining is known as regenerative chatter, and this phenomenon can severely limit the machining productivity. By modifying and optimising the tool's pitch and helix geometry, this regenerative chatter can be suppressed to increase material removal rate. In this paper, experimental verification of an optimised variable helix and variable pitch tools is presented. The geometry was optimised using a Differential Evolution (DE) algorithm. Based on stability diagrams of original and optimised milling tools, the experiment was conducted and the results were compared when chatter occurred. The optimised cutter significantly outperformed the original cutter in term of chatter suppression.