[Leica] Delicate Operation

[Don Dory]

Looks like an interesting project.  I wouldn't believe that Nikon used
non-standard screws as microscopes are not a million plus production run.
If you can determine the thread pitch and diameter then it will be easier
to search for what you want.  I suspect if you get close with a fine pitch
ruler or other measuring system then look for the closest listed in a
catalogue you will be on the money.  The hard part is possibly filing down
a too long screw as Nikon might have ordered a specialized length to fit
the desired thickness of the various tubes.

On Sat, May 22, 2021 at 9:44 PM Aram Langhans via LUG <lug at leica-users.org>
wrote:

> I have been looking for a decent microscope ever since I retired 13
> years ago.  A biologist w/o a microscope is like a photographer w/o a
> camera.  I have owned or had access to a microscope ever since 4th grade
> when I used my Christmas money to buy a Tasco. When in California I
> happened to look at Craig's List and found someone with a nice Nikon
> scope advertised "Like New" and two AO scopes missing some lenses he was
> tossing in all for $100.  It took a few weeks to hook up, but we met in
> a WalMart parking lot and I tried them out with power from my RV.  They
> were in sad shape.  The AO's were not bad, but the Nikon was really
> rough and the fine focus was seized up but it has nice "Plan"
> objectives.  I like a challenge so I offered $80 and he took it.
> Transported them home and took the AO's apart, lubed them and got one
> working quite well with a borrowed set of eyepieces from the Nikon.  The
> second one as an alignment problem probably beyond my ability to
> calibrate.  I had been using penetrating oil and wrenches on the Nikon
> for days trying to free up the shaft, but to no avail.
>
> I finally figured out how the focusing mechanism might be disassembled
> on the Nikon scope and took it apart.  I had nothing to loose.  Got the
> fine focus shaft out of it with a hammer and a punch.  It was all
> corroded and I think the scope had been dropped as the sleeve was
> partially bend.  Cleaned it all up.  Used a long drill to clean out the
> sleeve and a rod to straighten it out.  It is now all lubed and put back
> together, but I need to replace three set screws that were sheered off
> either by me or by someone forcing the focus mechanism.  One I have no
> idea where it is suppose to go.  Small metric.  I will visit Tacoma
> Screw on Monday to see if I can find anything, or else I will drill and
> retap with SAE screws.  Still have a stripped focus nob and tensioner I
> need to figure out, and the fine focus eccentric bushing that has a spot
> for 4 set screws but there were none in sight.  I might get this thing
> working after all.  I took photos of the process so I knew how to put it
> back together.   It is pretty complex but elegant.  Also a shot of the
> disassembled scope.
>
> Here is the scope disassembled:
>
> Nikon Scope-4193 (leica-users.org)
> <http://gallery.leica-users.org/v/Aram/misc/sc/Nikon+Scope-4193.jpg.html>
>
> Then the process involved in taking apart the focusing mechanism and
> then the reassembled mechanism starts here:
>
> Nikon Scope-4178 (leica-users.org)
> <http://gallery.leica-users.org/v/Aram/misc/sc/Nikon+Scope-4178.jpg.html>
>
> Comments welcome
>
> Aram
>
> --
> Aram Langhans
> (Semi) Retired Science Teacher
> & Unemployed photographer
>
> “The Human Genome Project has proved Darwin more right than Darwin himself
> would ever have dared dream.”   James D. Watson
>
>
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-- 
Don
don.dory at gmail.com