Optimizing the shaping technology and test methods for convex aspheric surfaces of large optical items

This paper discusses the automatic shaping technology for the convex hyperbolic surfaces of the secondary mirrors of telescopes with asphericity to 400 ?m, 1 m or more in diameter. It describes a method of testing a convex mirror with an auxiliary Hindle sphere and of optimizing this method by using two Hindle spheres of smaller diameter for one item instead of one sphere of greater diameter. A method is proposed of joining the topographical maps obtained from the results of testing the surface of a hyperboloid with two spheres. The features of fabricated auxiliary equipment (load-bearing fixtures, containers, devices for cementing interface elements) are presented.