13" mirror, 9 or 6 point cell?

I have a 13" dia., 1.5" thick mirror and want to support it correctly. What cell should I use? A 9 point or a 6 point cell? Also who sells them as I believe Novak cells are no longer being made. This would be to support my 13" mirror in a 16" I.D. tube? Thanks, Gerry

Gerry, 6 points should be more than adequate and probably preferred over 9 points. Here's a link to a good read on mirror cells design.

http://www.atmsite.org/contrib/Holm/Plop_optimized_cells/index.html

dan