Factors affecting form accuracy in diamond turning of optical components

The quality of machined optical surfaces is affected by machine tool accuracy, cutting tool quality and dynamic machining effects. This paper investigates the effect of cutting tool conditions and tool set-up error on surface distortion. Controlled cutting tests were performed on a two-axis diamond turning machine. Spherical mirrors with respective pre-set tool offset values and tool height values were turned. The relationship between machined form accuracy and tool offset and tool height was investigated based on experimental and analytical results. Influence of tool wear generated during machining process was studied. A spherical surface with a form accuracy better than λ/10 has been produced.