To: atm{at}shore.net
From: tkrajci{at}san.osd.mil
Reply-To: tkrajci{at}san.osd.mil


>From: Chuck Dethloff 

>One thing that I learned from my friends experience was that having three
>mirror clips instead of only one (which I have traditionally done because
>the other two seemed redundant) is what saved Howard's mirror from being
>possibly broken. The OTA was laying flat on back upside down when I came
>upon it. The mirror no longer supported in it's sling was rather now
>supported by the upper bumper and tipped forward against the two mirror
>retainer eye bolts attached to the lower two bumpers. Without that
>redundancy his mirror would have undoubtedly fell forward in the box and
>could have been scratched or possibly broken.

Some folks are hard sold on the mirror clips and sling concept.  When will
they let go of the idea?  When it's pried from their cold, dead fingers. 
;-)

My sixteen inch mirror is RTV glued to a six point support.  No slings. No clips.

In a manner of speaking it is held in place by six, adhesive, shock
absorbing, high strength clips.  In my opinion that is far better than
three mechanical edge clips that let the mirror rattle about, and perhaps
present a chipping risk during rough transport and handling.

I don't care what orientation my mirror box takes during shipment.  The
mirror is bonded to the cell and won't fall out.

When I first bonded the mirror to the cell, I tested it in stages.  At
first I did some gentle tilting of the cell, then more tipping.  No
problems.  Then I inverted the cell.  Again, no problems.  Then I put some
weight on the back of the mirror while the cell was inverted.  Once again,
no problems.  Then I grabbed the cell as if I were an olympic athlete
preparing for the 'hammer throw'...and whirled the cell/mirror about. Still
yet again, no problems.  (What other tests would folks like me to
conduct?...short of damaging or destroying componenets)

My telescope was shipped out to Tashkent...10,000 kilometers and three
months.  It survived intact, and when I assembled it for the first
time...collimation was only a little bit off.  Not too shabby.

Can we please put the mirror clips and sling idea to rest?

Tom Krajci
Tashkent, Uzbekistan

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