Thursday, May 6, 2010
Because of the damage to the primary mirror, I didn't want to put much stress on the mirror, so I went for a six-point primary support cell, with the mirror glued with silicone glue. The positions of the points were optimized with Plop.
The cell consists of a piece of scrap hardwood. It has carriage bolts coming in through recessed holes on the top surface, JB Weld'ed in place. The springs are valve springs from an old mower. I went to a mower repair shop, and the man there removed them from a junk mower for me for $5. Super stiff, great stuff. Because the springs are big, I made recessed holes for them (with a 1.25" paddle bit in a drill).
There are, of course, lots of ventilation holes.
The carriage bolts come out of the bottom of the mirror box, where the collimation is adjusted with knobs.