Name This Optical Tool!

Factual Questions
1

I need an optical tool but I can’t find it, because I can’t search for the name, because I can’t remember it.

It’s a pair of two “L”-shaped beams that slide together and apart. Optical assemblies such as binoculars, telescopes, camera lenses and such are fastened together with threaded rings that have two notches in their edges. This tool is used by spreading the two sides apart until you can engage the two notches, and screw in or unscrew the part. No other tool will substitute.
I am 100% certain that Edmund Sicentific used to sell these things, but I cannot find any on their website now.
Anybody know?
~

2

The photo isn’t exactly as you describe, but is it possible you are referring to a type of spanner wrench?

3

Spanner Wrench

4

You want Edmund Optics rather than Edmund Scientific. The company split a few years ago and Fischer(?) now owns the educational bits.
Send for the Edmund Optics catalog, it’s chock full of optically goodness!
Here’s a Lens Spanner Wrench that’ll loosen those rings for you.

5
      • Well damn. I thought it was “spanner” but when I Googled on variations of that I kept finding hydraulic tools. Tnx.
        ~
6

You may be able to make a tool that works for this job:

  1. Take an old hacksaw blade (ideally, of a thickness slightly less than the width of one of the notches in your threaded ring). Using pliers, break off one end and grind it square.

  2. Break off the other end so that what remains is a bit longer than the distance between the notches. Then carefully grind it to exactly the right length.

  3. Clamp the blade between two pieces of wood (cross section about 1cm x 2cm, but not important) that are slightly longer. The teeth should be buried and just enough of the blade exposed to reach to the bottom of the notches.

  4. You now have a sort of “giant thin screwdriver” of the right size for the job.