Grinding a 12.5-Inch Telescope Mirror With 120 Grit
April 25th, 2012
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Early stage of grinding a 12.5-inch telescope mirror blank with an 11.5-inch tool. The tool consists of ceramic tiles arranged on a convex surface that matches the curve of the mirror (roughly f/4 focal ratio). The abrasive is the very coarse 120-grit Silicon Carbide powder, which looks like black sand. Grinding this blank with the much finer Aluminium Oxide can be seen in my later video. Progress on this project is documented at astroscopy.wordpress.com Many thanks to the telescope workshop of the Santa Barbara Astronomical Union for making this project possible!
