Abstract
This paper reports a result of cutting an acrylic workpiece to form a convex nonaxisymmetric surface, using a round tip diamond tool and a ultraprecision lathe with 3-axis simultaneous control. The maximum and minimum sags of the surface differ by 0.1 mm, which requires the tool to travel back-and-forth in synchrony with the workpiece rotation. Tool overshoots after changing directions left bulges and dents on the finished surface, resulting in a form deviation of 4 μm (P-V). Excluding these particular points, the form deviation was within 1 μm (P-V) and the surface roughness was about 90 nm (P-V).
