Robot-Assisted Vibration Polishing of NiCo Retroreflector Moulds

Abstract

Galvanic retroreflector moulds suffer from fabrication errors and considerable wear due to the manufacturing process and the subsequent use for injection moulding. To remove degradations like flaws and wear marks from the mould’s optical surfaces without tedious manual labour, a partially automated process chain using a 6-axis robot is being developed combining surface metrology and machining technology. The areal limitation of the structured surfaces excludes conventional rotatory polishing processes. Vibration polishing is applied instead to remove critical surface errors and to enhance surface roughness to a near optical value of Sa ≤ 50 nm. The work presented in this paper gives insights into experiments performed on a robot polishing system and illustrates and the suitability for an application in the aforementioned partially automated process chain.