Quote:
Originally Posted by bartman
Just a question: you say " With the mirror mounted on it (fastened through central hole with wave spring washers to apply and hold the correct tension)".
How/ what????  Does the mirror have a tapped thread in the bottom?
Or a hole through the middle(couldnt see one). |
Hello Bartman,
The conical mirror has a blind hole in the centre at the back (it doesn't go all the way through, so the face of the mirror is not perforated). In this hole Mark Suchting (who made the mirror for me) has set a 1/2" BSW nut in resin. The nut accepts some threaded rod which protrudes through a hole in the carbon fibre base plate that the mirror sits on. Then add some wave spring washers and another 1/2" nut to secure the assembly to the base plate with sufficient tension to hold it firmly in place. The wave spring washers then maintain this tension against expansion / contraction due to temperature fluctuations, etc. It is a simple but very effective mounting system and avoids all the usual dramas with flotation cells and edge supports. The tension on the central stud does not distort the mirror at all; a fact which Mark has confirmed by cranking up the tension well beyond that needed, with no distortion showing under his artificial star test.