[ATM] From mirror support to the frame

["Alan K. Henderson" <alankh@ev1.net>]

Nils Olof Carlin said in the "Industrial-strength mirror sling" thread:

> One thing is that for minimum astigmatism the supports should be at 45 deg
> to the vertical (and also, of course, to the horizontal) - in your sketch,
> the points look a lot closer to the vertical than that. But you have added
> some 45 deg members that would be fine to mount the supports to. If I had
a
> large, heavy mirror, I would use skateboard wheels - holding the mirror in
> place, gently, without pulling the edge....

I've decided to abandon the sling and go with the two-point support, with
each supports placed at the middle of the diagonal sections - see update to
http://users3.ev1.net/~alankh/Cell4.gif. I will stick with my original idea
for using chair leg swivel glides. Night Sky uses something vaguely
resembling chair glides for lower mirror supports - about the only part of
the cell that has anything in common with mine:

http://www.nightskyscopes.com/site/std_mirrorcell.shtml

Now for the frame. One-inch steel tubing would be sturdy enough for the
50-pound mirror, but steel is heavy, and this design uses about 13 feet of
it. (Not counting the tailgate.)  I would like to use aluminum, but the
stuff available at Ace Hardware or Home Depot isn't strong enough. Where can
I find a heavier-duty variety of square aluminum tubing?

Alan K. Henderson


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