This work presents the deterministic hydrodynamic polishing system (HyDRa (HyDRadynamic Radial Polishing Tool) based on a polishing tool developed at the Instituto de Astronomía, UNAM. HyDRa is one of several modern deterministic polishing techniques that allow for computer controlled finishing of complex optical surfaces. The HyDRa system is based on a hydrodynamic polishing tool that generates a variable-density abrasive flow that makes possible the production of high-quality optical surfaces of diverse materials. The tool comprises several stacked operational stages that generate a grazwing abrasive flow with a predictable, zero-force erosion footprint on the workpiece that removes material. A recent innovation to the hydrodynamic polishing tool adds a switching capacity to the tool that allows the polishing action to be interrupted at will, without losing the stability of the operating parameters. This further increases the versatility and performance of the tool, since it is now possible to polish only the areas where the surface needs correction. Pulsed polishing also adds several techniques to this polishing method that further increase the system’s versatility.
Part of the book: Abrasive Technology