Abstract: A fixture for providing positive control over a workpiece as it is being acted upon by a cutting or finishing tool. A base having a flat working surface is provided with a fixed guide member having a contoured control surface formed along the periphery thereof. A workholder is slidably supported upon the working surface of the base and is arranged to move in abutting contact against the control surface of the guide whereby a prescribed motion is imparted to a workpiece supported in the holder. In one form of the invention, the workholder is mounted upon a turntable that is rotatably supported in a circular guide whereby the work is caused to rotate about a fixed axis.