Abstract: A machine tool and its associated control system has workpiece holding me which are mounted on a frame for rotation about a fixed axis and are adapted to support and to be fixedly connected to a workpiece, such as a crankshaft, centered on that axis. The machine tool further has a tool carriage which is slidably mounted on the frame for displacement in a direction which is transverse to the rotational axis; first drive means which serve to impart angular rotation to the workpiece holding means about the axis; second drive means which serve to displace the tool carriage in the transverse direction; and electronic control means for controlling the first and second drive means so that the desired angular rotation and transverse displacement are performed with a predetermined, generally nonlinear relationship to each other.