OK, I see. The Nylon is used in the form of hardware. 3 plastic screws used for centration adjustment, near the rear face of the mirror so no distortions are introduced on the optical face. They are turned until they just touch the edge. The mirror cools during the night, so it contracts slightly. No strain is introduced from the clips because the pressure isn't increasing. Pyrex contracts very little; in practice a gap never really opens-up. Face clips are not needed if the telescope never tilts past horizontal- as some large Dob owners can attest-to, but it's typically not possible with a portable, close-tubed Newtonian. What Kurt is trying to combat is the lateral motion, not fore-and-aft mirror shifting. I should take some photos of my home-made 10" floatation cell. 9-point support, completely adjustable centration, fan cooled with internal batteries. On 8/13/07, diveboss@xmission.com <diveboss@xmission.com> wrote:
The hard plastic.
Quoting Chuck Hards <chuck.hards@gmail.com>:
Not sure I understand your question, Guy. Attaching what?
On 8/13/07, diveboss@xmission.com <diveboss@xmission.com> wrote:
How are you attaching that?
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