Prediction of the removal profile for tools having a finite contact patch

A new generation of compliant tools and processes called UltraForm Finishing is under development at the Center for Optics Manufacturing (COM) and OptiPro Systems (Ontario, NY). The purpose is to achieve rapid, high quality finishing of hard materials. These compliant tools exhibit a large contact patch that can be up to 1 cm wide. A numerical model was developed to account for finite contact patch geometry on removal for a flat rotating axisymmetric workpiece. This model was used to determine the depth of removal as a function of radial position after the polishing tool has completely traversed the workpiece from its center to a given radial position. The depth of removal was investigated for circular and oval contact patches and a variety of removal functions. A constant removal depth is desired to minimize the induced figure error. Predicted results were compared to experimental measurements of induced figure error.