Homebrew viewers

[LDAEnt@xxxxxxx]

To continue on the thread of homemade viewer ideas:
I can't think of a simpler design that accomplishes so much as the
Taylor-Merchant fold flat mailable Realist slide viewer.  This design can be
made simply, and can achieve very precise alignment and focusing ability.
This design is a parallel link (or toggle) arrangement.  Look in an older
REEL 3-D cat. or any Stereo World for ads to see what I mean.
This design is a good starting point for either a Realist or twin full frame
homemade viewer. This project is for the at least modestly skilled hobbiest,
and creativity is needed to fill in my missing information.  
Buy the Taylor Merchant mailable scope ($2.95) to use as a pattern.  Study it
to see how it works.  Cut it along a seam and open it up to use a basis for a
pattern.   The scope for twin 35 slides will be larger than the cardboard
scope, so proportionally scale up the pattern. And the lens FL may be
different, so adjust the pattern to give the lenses enough room to focus.
Making cardboard prototypes and tape for hinges to check this is useful. (no,
this isn't a quick project)   :-)
Use thin hobby store hardwood, maybe 1/16" thick. (you might be able to make
it out of basswood too).  Buy some light duty hinges , maybe piano hinge or
other light weight hinge.  Transfer your scaled up paper pattern to the wood.
 To keep the parallel link pairs the same dimension clamp two pieces together
and cut the two at the same time. An X-Acto knife will cut this wood (and
your fingers if you are not careful).   This way you can be off a little on
the dimension but still have useable links because they match. 
After all of the pieces are cut, use tape for hinges and assemble to check
for smooth operation and parallel faces.
Mounting the lenses is probably best done by using blocks of wood a little
bigger than the lens O.D. and drilling a through hole and following with a
counterbored hole to act as a lens rest.  These two blocks can be glued to
the inside of the faceplate (at your best interocular distance).  The hinges
can be bolted or epoxied to the wood.  The wood can be stained and coated for
a nice appearance.  The slide holder should be on the outside of the back
face.  It is nothing more than small sq. or rect. wood strips (buy at hobby
shop) cut and glued into two 2 x 2 frames to drop the slides into.  Be
creative. Separate the slides by 1/2" space in the middle.
Lenses: you can use single element lenses, or achromats.  If George T. still
has some of the NOS Revere achromats, the 47mm fl. version would be good, and
low cost. 
Many details are left to the creative imagination.  
The light box ideas are in another post.

Alan Lewis 


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