This sheath is designed to protect the outer casing of the eyepiece from being damaged
by the bare metal of the screws.
This protection is not absolute and some scratches
or damage to the outer casing or its coating / paint-work may still occur due to
the abrasive effect of the hard plastic of these folds
so the user must be aware of
this and take whatever additional precautions they see fit to protect the casing of their
eyepieces (such as applying some tape to the outer casing of the eyepiece before
inserting it – although removing sticky residue left behind by some tapes may also cause
damage to paint or other coatings so this risk is never fully zero).
If your eyepiece diameter is so big that the clamp will tighten against it without sufficient
deformation to break the thin flexure fold connections then very little lasting deformation of
the flexure folds in the clamp sheath will occur. However, when using the clamp
mechanism after those flexure connections have broken (and so the flexure folds of the
sheath protrude into the clamp), before inserting any eyepiece unscrew the three clamp
screws and push the indented parts of the internal sheath folds up against the wall of the
clamp with a finger or blunt instrument to achieve maximum clearance room inside prior
to fitting an eyepiece.
Never use an instrument that could damage the plastic
sheath (like a screwdriver or other metal instrument) to push these folds back
because these can wear away or tear the protective parts of the thin plastic
sheath that lie over the metal screws and expose the metal screws directly to
your eyepiece casing, at which point damage to the casing will definitely result if
you continue to use the clamp
. If the inner sheath does get damaged for any reason
do not use it. Print and fit a new sheath using the freely available design files for this part
of the camera (see below). One of the advantages of using the AF51 is that these parts
can be relatively easily and cheaply replaced as required through 3D printing (if you don’t
have a 3D printer, there are online 3D print services that can be used).
I have made the CAD files for this clamp system open source. This means that you can
modify the clamp design and print your own version to fit some eyepieces that will not fit
with the standard clamp supplied with the AF51 or to replace worn or broken parts. See:
https://github.com/TadPath/PUMA
for the CAD files and keep an eye on the PUMA
Microscope YouTube channel for instructional and demonstration videos that may help in
this regard.
Once the inner sheath is prepared by pushing back any protruding folds, carefully insert
your eyepiece about 20 mm into the sheath till it gets stopped by the inner ledge of the
clamp (do not insert it any further than this even if it does not get stopped by the ledge) –
see figure 3.14.
OptArc AF51 Camera Page 40 of 99 User Guide v1.02
