On 2008-03-07, Christopher Tidy wrote:
snip
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.
I actually need both. Most urgently I need the kind which fits into two
slots diametrically opposite each other in the threaded ring. The slots
appear to be square in cross section.
Typically -- most sets can handle both depending on the tips
installed.
I could also do with having one which fits into a pair of round holes,
too. Like the kind used for "spanner head" screws. But this tool must be
like a screwdriver, as it has to go down the tube of the microscope for
removing the nosepiece.
If you need it, I can photograph my set for an example of a
pretty good set.
If they're no longer available, don't worry. The maker's name might be
useful so I can search on eBay, though.
I have no idea who made them, as I never saw the original box.
All parts have the numbers stamped on them.
49A17795-1 is the shortest bar
49A17795-2 is the middle length bar
49A17795-3 is the longest bar
49B17788-R is the right-hand joining bracket
49B17788-L is the left-hand joining bracket
49B17790-R is the right-hand upright tip holder
49B17790-L is the left-hand upright tip holder
Into one end of each of the above is a double-ended pin with the
tip turned to 0.061" diameter on one end, and to 0.031" on the
other. Others probably existed, but these are all that I have
until I need to make more of my own. (As a matter of fact, this
is the first time that I knew that it was double-ended, since I
have never needed to change it. The OD of the pin body is
0.125" (1/8") The other end of the holder accepts the following
tips.
49A17791-1-R is the right-hand tip for thin screwdriver slots (0.043")
49A17791-1-L is the left-hand tip for thin screwdriver slots
49A17791-2-R is the right-hand tip for medium screwdriver slots (0.062")
49A17791-2-L is the left-hand tip for medium screwdriver slots
49A17791-3-R is the right-hand tip for wide screwdriver slots (0.091")
49A17791-3-L is the left-hand tip for wide screwdriver slots
All of the screwdriver tips look like somewhat this:
+-+
| |
| |
\ /
V
with the 'V' point towards the outside. The arms for this are at right
angles to the beam, but have an offset so they can be set up for
something with a small ID or a large ID.
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.
Do you know what the official name for the set is?
Since Edumund no longer carries the set, the name does not
matter at all. And anyway -- I found a duplicate of it made in India
posted later in the previous article, aand still quoted below.
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
Unfortunately I can't tell from that picture which tips are included.
It looks to me as though there are one slot pair and two pin
pair.
Almost certainly both pin and slot tips, just as mine was. And
-- since the tips are made from standard hex stock, you can easily make
some for smaller or larger slots at need. Mine had 1/4" hex stock for
the tips, but one from India is more likely to be 6mm hex stock for the
tips. I forget whether the cross-bar was 3/8" hex stock or 1/2".
It's also too big for my second application.
Maybe, maybe not. The tips can be pointed towards each other or
away on the smallest hex cross-bar. Note that there are three notches
in the bars which are slightly angled. You can get a minimum spacing
while tapering to the outside by interchanging the sides and moving to
the notches closest to the tips. And normally you would select the
shorter fat bar for the crossbar for that application. So -- the
question is "what ID does it need to fit through, and just how deep?
Or -- you can turn a cylinder to fit inside, with a knurl at the
outside end, and either mill it to form screwdriver bits, or drill it
and insert bits made from drill rod (silver steel).
Note that I have made a deep reach spanner (to get to a nut in a
50 cc Honda many years ago) by taking a spare socket-wrench socket of
appropriate diameter, and filing away everything except enough to form
the screwdriver tips. This is an option for you too, with the
additional benefit that you probably have a milling machine available,
which I did not at that time.
I've also been known to take needle nose pliers and file the
tips down to the right thickness and angle to form a wrench for optical
rings. There are *tons* of ways to do this -- depending on what tools
you already have to hand.
By the way, this is a ring spanner in the UK:
http://www.britishfasteners.com/mm5/...00003/er14.jpg
O.K. Not an open-end but a "box wrench" in our (US) terms.
Enjoy,
DoN.
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