|
On the 18" I sold to Gove, the main mirror was sitting on an 18 point suspension. This was easily achieved without any major machining work by cutting six triangles from 6mm aluminium plate, fitting three felt pads at each corner on the top surface and partly drilling an 8mm hole in the bottom surface in the centre.
Arms, from 6x 12x18 brass bar were cut to act as dividers between the triangles, two 6mm drilled recesses on the top of the 6mm surface and one in the middle of the bottom surface. These "balance arms" were then mated with centres of the triangles using 6mm ball bearings embedded in silicon; this gives a 6 point support onto a single point contact underneath.
The base plate was then drilled and tapped in three places and 12mm screws with the ends ground to 6mm points placed from the back; the "balance arms" then sat on these screws; the mirror on the front.
Three restraining clips, just to the side and above the mirror gave lateral and radial protection.
Hopefully it's still working well!!!
|