Correction of remounting errors by masking reference points in small footprint polishing process.

The remounting accuracy of optical components between measurement and polishing affects the polishing results, especially for small polishing footprint processes such as magnetorheological jet polishing (MJP). In this paper, two important remounting errors (translation and rotation errors) are discussed, and a masking method is proposed to correct these errors. A mathematical model that describes the relationship between remounting errors and reference points is constructed. A mask is created to provide reference points on a sample because such points are important for identifying remounting errors. The remounting errors are then used as bases in correcting the parameters used for actual polishing. Experiments are conducted on a K9 optical sample to validate the proposed approach. After the reference points are obtained by measuring the mask on the sample, the remounting errors are derived. The translation errors are 5.61 mm in the X direction and 6.08 mm in the Y direction; the rotation error is 4.1°. Deviations from the desired positions are eliminated and the desired surface smoothness is obtained after parameter correction. Results indicate that the proposed method is suitable for high-precision polishing.