The K-20 Project

K-20 Project Home     Design Specifications     About The Optics     Resources     Questions/Comments

2/7/2007 - The 18 Point Primary Mirror Cell - Part I

Previous Entry     Next Entry

I have completed 90% of the primary miror cell. All that remains are to hang the sling when the specially made split bolts arrive, attach the kydex donut to hold the triangles in place and attach the cooling fan....a total of 10 minutes of work. This steel open frame and "whiffle-tree" setup will support all 50 pounds of solid pyrex and keep it safe when on the road. The tailgate and cell are designed to be a permanent home so much so that the mirror will be cleaned IN the mirror box! All components are stainless steel with the exception of the tailgate which has been primed and sealed. The next time I work on this cell will be sometime toward the end of May as I ready it to test the focal length of the mirror upon its arrival. NEXT UP: The Secondary Cage takes shape!

ENTRY PICTURES

Yours truly hand mitering the side pins. Made of solid PVC and 1 inch in diameter, they will keep the mirror in the cell and stop it from touching the inside of the mirror box during transport. Holy Hardware Batman! All mirror cell / tailgate parts ready for assembly. Completed "whiffle-trees". 6 triangles with 3 points each. The bars connecting each pair of triangles are attached to the collimation bolts. Completed cell with sling in position, it will be attached to special split bolts on each side. Note the configuration of the triangles....although not exactly aligned yet, this geometry results in each of the 18 points supporting the SAME amount of weight across the mirror. That little round thing on the middle rung in the center is a quarter for scale.

Close