On 2008-03-05, Christopher Tidy wrote:
DoN. Nichols wrote:
[ ... ]
Hmm ... the light is not focused where it passes through the
mirror, so you might be able to take a first-surface mirror and scribe
through the silvering in a pattern to get something like 30-45%
reflection, and then you might be able to use it. I've seen scribed
patterns in mirrors in SLR cameras, with the CDS cell for metering
behind the scribed section.
A scribed mirror is a fascinating idea! But it seems like it is done by
total internal reflection in this microscope. I've yet to completely
absorb the intricacies of the optical system, but it's interesting to
note that the reflector pivot is not directly above the centre of the
objective lens. It's slightly in front on the lens, i.e., closer to the
light source.
O.K.
I also need some lens-removing tools. Not sure what they're called. I'll
probably post a message about those at r.c.m in the next few days.
Which format? The ones to access two slots on opposite sides of
a retaining ring? Those are what would be called a spanner wrench here
(actually -- "ring spanner") in the US -- unlike the UK where I believe
the term to match what I would call an "open end wrench". The ones
which I have are sets of arms which slide along a bar and are locked to
the bar at the proper distance, and which mount either pins or slot
drivers of appropriate size to match the slots or pin holes.
If you need it, I can photograph my set for an example of a
pretty good set.
I also used to have a set from Edmund Scientific which used some
hex steel shaft to hold the arms, with slots milled in them to allow the
arms to cross at a slight angle to the expected right angle. In the
ends of the arms is a hex socket with a setscrew (grub screw?) to hold
them in, and then a pin or slot driver machined on the end. These were
not nearly as rigid, but were quite affordable at the time. I used them
both for camera lenses and for wris****ch back removal/replacement.
O.K. Edmund no longer carries anything of the sort, but I have
found an example made in India to the same design. Just better
packaging as it is in a hinged wooden case instead of a cardboard box.
I have not found a price, but perhaps you can with more searching.
Sorry about the extra-long URL
http://anuuj.trustpass.alibaba.com/product/12241451/Spanner_Wrench_Lens_Opening_Tool_Tools_Adjustable. html
Let me break the URL into sections for individual cut-and-paste
if your system does not honor the '' and '' to keep it together:
http://anuuj.trustpass.alibaba.com/product/12241451/
Spanner_Wrench_Lens_Opening_Tool_Tools_Adjustable. html
Or do you mean those to grip the knurled ring on the typical
microscope objective lens? Those *should* be loose enough so finger
grip should be sufficient to unscrew them.
There are hinged versions of the spanners which are sold to
remove the screw-on backs of "waterproof" watches. There is typically a
knurled wheel in the middle of a double-threaded screw (LH on one side,
RH on the other) between the arms to adjust the spacing with sufficient
precision.
Enjoy,
DoN.
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