Whutizzit? brass peg/screw on back of Copal #3 housing

[alfredian]

I now have several Copal #3 shutters, with/without lenses. There is a brass peg on the back, in curving track partway 'round the lens opening. This has a screw-slot in it and the thing is (apparently) movable. Is it only there to help orient the lens on the lens board, position variable to allow adjustment? or does it link to something inside the gearbox, like the aperture or timing/shutter assemblies?

I don't have "tools" to modify lens boards other than small files, and although my #1 & #0 shutters don't have them they are depicted (in manuals, etc.) as maybe having the orientation peg as well. A few of my variously sized boards have a notch/cut out for a peg, but most don't. Any illumination would brighten my day, thanks, alfredian

[Mark Sampson]

It's a locating pin to keep the shutter from rotating on the lens board. Generally a good idea to use it- by drilling a small hole in the right location. You can just remove the screw and mount the lens without it... but it's best you use it if you can.

[alfredian]

Thanks for the rapid reply - what I opined is now confirmed. That is what a couple of product brochures (Nikkor?) stated. Few of the smaller format shutters have the peg, a few 2nd hand boards do. I'll check out pre-drilled boards & maybe a useful drill for others. --alfredian