| Abstract : | India’s in-kind contribution to the TMT project includes Segment polishing (84), Segment Support Assemblies (580), Actuators (1535), Edge Sensors (3284), Software development for the observatory, and design and development of science instruments. TMTs Primary Mirror (M1) is composed of 492 hexagonal aspheric segments. To compensate for residual polishing errors, installation errors, gravity effects, and parasitic forces in the whiffletree support, each segment is equipped Segment Support assembly (SSA) comprising of 21 Warping Harness (WH) mechanisms, which allow low-order corrections to the optical surface. Presently TMT SSAs are being manufactured and assembled at L&T, Coimbatore. Each TMT SSA consists of around 500 individual components that are put together using a rigorous assembly procedure to ensure desired functionality and performance. To ensure the functionality aspect of SSA after assembly, we have devised a test procedure and implemented it using the SSA Test controller developed by TMT and S&T Netherland. Tests include - Health Check of WH actuators and Leaf Spring, Leaf spring offsets, dead band width, WH operational stroke, stroke-strain relationship, hysteresis, and noise measurement. In this paper, we will describe different tests performed, test equipment used, and test results of the first two ITCC SSAs assembled at L&T, Coimbatore. |
