Re: STEREOSCOPE PARTS

[LDAEnt@xxxxxxx]

>The main problem is finding source for scope lens....
I am also all too familiar with the problems of building/repairing
stereoscopes because I designed and manufacture my SaturnScope I viewer.  The
lenses are the most vexing problem, but there are options with some
compromises.  Firstly, I had to contract with a lens manufacturer for custom
glass prismatic lenses for my scope.  I could do this because of the quantity
that I produced, not a practical solution for a handfull.  I have been trying
various other options for "one off" scope construction or fixing of old
scopes.  One method would be to buy the Taylor Merchant scope lenses for
$7.95/pair.  They are molded plastic but are meant for scopes.  They would
not be friendly for installing into an antique viewer because they mold a
frame/flange integrally with the lens.  This makes mounting in a new scope
easy but not for an old scope.  You could saw the flange off of the lens and
custom size the lens for your scope mount size.  Tedious but should work.
 This lens is a bi-convex lens, the same as most antique lenses, so it should
drop in just fine.  Modern scopes use plano-convex lenses.  Another options
is to saw cut the lenses out of a plastic magnifying "glass" unit.  I found
that a 2X or 2.5X magnifier (about 4" in dia. I think) is just right.  I just
marked the lens outline onto the one piece lens and band sawed it into two
rectangular half lenses.  When you swap the lenses left to right with the fat
edges out this makes your scope lens pair. This lens actually had good image
quality, no apparent distortions due to molding (due to the original oversize
4" dia. I feel).  The Taylor-Merchant lenses occasionally have distortion,
and have a magnification of about 2.2X.  The magnifying glass lens is a 2X,
so it is slightly less magnification than the standard of 2.3X, but unless
compared side to side it is not a noticeable difference.  Glass lenses are
not easy to get without placing a custom order of your own.  If you can saw
cut glass lenses then you could get your pair the same way as I described for
the plastic magnifier.  You need one 3" or larger 200 mm focal length lens to
cut up. Just for fun, I recently purchased a small lot of Achromat scope
lenses for a special edition model I am planning.  I don't think anyone has
ever made a Holmes style viewer with achromats.  They are very thick and very
expensive. 
As for the sliding stage spring clip,  I have used a common hardware store
nylon spring clip (sold as an electrical wire spring clip holding device)
 modified slightly, paired with another one,painted gold, and fastened to a
thin wood cross piece and a small knob. This makes a one piece, good looking,
great working, "S" shaped spring assembly without sharp edges, and with the
addition of two felt pads it won't harm the wood when sliding.


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