Part Support Studies for Diamond Machining Mirrors

The manufacture of precision optical surfaces by diamond machining requires a high quality diamond tool, a low vibration, high precision machine, .a stable environment and rigorous machining practices. A view of a diamond turning machine at the Oak Ridge Y-12 Plant(a) is shown in Figure 1. This type of machine is being used.to produce optical surfaces on mirrors such as shown in Figure 2. This mirror, having dimensions as shown in Figure 3, is machined by turning about the mirror centroid. As with any machining process, the technique used to hold the part during machining is critical when trying to achieve an accurate contour. Part–holding errors can arise from centrifugal forces, part motion with respect to the fixture, or distortions introduced into the part by the fixture. A good fixturing technique will minimize these errors but must not be too cumbersome.