Fundamental comparison of the use of serial and parallel kinematics for machines tools

Classical cartesian kinematics Machining Center (MC) structures are compared with parallel kinematics hexapods (HX) structures from the point of view of workspace, stiffness, accuracy, acceleration ability, and motion dynamics for use as high speed milling machines. Concrete stiffness values are used as;achievable. It is concluded that variable strut length HX are fundamentally inferior to the MC and cannot practically be used as high speed milling machines. The constant strut length HX offer larger workspace and higher strut stiffness and may produce characteristics comparable to MC in particular designs.