A new tooling system for corrective finishing of narrow cylindrical optics

Finishing of complex surfaces needs simultaneous movement of multiple axes and precessing the tool on the surface in a desired tool path. For finishing narrow internal surfaces, the conventional spherical or flat end tools are difficult to precess inside the geometry. Therefore, this work presents a new tooling system for grinding narrow channels on tungsten carbide surface, to be used in optical applications. A thin wheel type finishing wheel and related jig is designed to use on an ultra-precision finishing machine. Finishing using the newly developed wheel type tool with different grade shape adaptive grinding pads could generate excellent surface finish within Ra = 3 nm. Form correction capability of the developed tooling system was also verified where the form error of the channel could be reduced to ~7 μm P-V from an initial error of ~42 μm P-V, in 5 h of processing time.