Abstract Details
| Name: Vineeth Valsan Affiliation: Indian Institute of Astrophysics Conference ID: ASI2016_554 Title : Development of Stressed Mirror Polishing Technology Authors and Co-Authors : S. Sriram: IIA; N. K. Mishra: IIA; G. C. Anupama: IIA; J. P. Lancelot: IIA; Abstract Type : Oral Abstract Category : Instrumentation and Techniques Abstract : Stressed Mirror Polishing (SMP) is a fast and low cost method to polish large off-axis aspherical mirrors. The mirror blank is warped by the application of moments and shear forces around the periphery of the mirror blank. There will be a Whiffletree system supporting the mirror blank from below. After the application of moments, the top-surface of the blank attains the profile, which will be the exact opposite to the required profile. This surface undergoes polishing to acquire a spherical profile, following which, the stresses are removed and the mirror deforms itself to achieve the required surface profile. There are four components of SMP. 1. Stressing forces: Applied through levers bonded around the outer periphery of the of the mirror blank; 2. Self adjusting back support to achieve Zero-G condition; 3. Lateral constrain: The segment must be supported against lateral (side) loads that would tend to shear the part radially off the fixture and against clocking (rotation) on the fixture; 4. Axial constrain: In order to limit the axial movement of the mirror blank. This work deals with the design of all these components. Also discussed are the methods for calculating the amount of stress that has to be applied to the levers, modelling the support points from below the mirror blank and also the axial and lateral constraints. |