COMPARISON AND SELECTION OF A3 AND Z3 PARALLEL ROBOT STYLE SUPPORT STRUCTURES TO EXPAND THE TECHNOLOGICAL CAPABILITIES OF MILLING MACHINE

Abstract

Three-axis CNC numerical control machine tools often have limited capabilities when machining three-dimensional surfaces. In this case, the kinematic chain is often extended using a fixture that has the structure of a parallel robot, called hybrid machine tools. In fact, when choosing this extension fixture, there may be more than one choice and comparing the suitability between candidates according to a series of different criteria to choose the optimal solution is often not simple. By researching and comparing two commonly used structures in industry, A3 and Z3, this paper proposes a solution to compare criteria related to pressure transmission angle. On that basis, the most suitable support structure to expand the technological capabilities of the milling machine can be selected. Through research, it was found that in the same control space, the A3 head outperforms the common Sprint Z3 head, being the better choice in this case. The proposed method is a suitable tool to support decision making in similar cases.