Hi Kim: --- Kim <kimharch@cut.net> wrote:
Do you or does anyone else have experience using silicone glue on larger and/or thinner mirrors?
Not on anything larger than 6". It worked well mechanically for that size, but I had trouble getting it off when it came time to recoat the mirror, at the request of the person doing the aluminizing.
What kind of mirror cell are you contemplating?
9-point floatation, though an 18-point cell is also a possibility. Aluminum framwork, steel adjustment springs. This mirror has a 1:10 thickness-to-diameter ratio, not quite full thickness but not especially "thin", either. Pyrex, old Coulter manufacture. Ronchi test shows a good figure, slight hill in the center that will be in the secondary shadow.
Have you considered any alternatives to both solid-tube designs and truss-tube designs?
Yes. One possibility is a two-piece tube that has no possibility for slop or mis-alignment when assembled. I also have considered a "short-truss" design, with a tubular front and rear end, and very short truss tubes in-between, of larger diameter than usual. The truss section could even be built as a unit, that is, the tubes themselves permanently attached to front and rear rings and so not as subject to misalignment. In this case, it's really a 3-piece tube. It is much easier to design a multi-sectioned tube to assemble perfectly each time, than a conventional truss, IMO. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com