Re: ATM question: sling or pads for edge support?

["Tom & Lou Krajci" <krajcit@3lefties.com>]

> From: "Herb Kasler" <h.kasler@worldnet.att.net>

>         I'm hoping to get a variety of opinions from the group on what
type
> of edge support is best for my mirror. The scope I'm building is a 16" f/4
> truss-tube dob with an all-aluminum OTA. The mirror is made of BVC, and is
> about 1-3/8" thick at the edge. It weighs in at 22 lbs. The mirror cell
will
> be 18 points.....

I recommend no edge support whatsoever.  RTV the mirror to the cell.

My sixteen inch mirror (1.6 inches thick) is glued to my six (yes, only six)
point support (as calculated by Richard Schwartz and PLOP)...star testing by
experience observers has yet to show any image distortion due to the mirror
cell...atmospheric seeing has been my prime limting factor, followed by tube
currents (which are mostly cured by two fans, each rated at about 100 CFM).

Hope this helps,
Tom Krajci