I always use the anti-rotation pin. Its purpose is to keep the shutter from rotating and possibly coming loose due to frequent manipulation of its controls.
The pin is 2mm (0.080") in diameter. Its hole is located on the shutter mounting hole circle, extending 1mm outward from it, usually at the 12 o'clock position. The diameter and depth (radial) of the pin hole are not at all critical. You can use a small triangular file to cut it.
Correct shutter hole diameter is important. The hole is a bit larger than the shutter mounting thread, to accommodate the locating ridge on the inner surface of the retaining ring. I don't know why they did it this way, possibly to prevent damage to the shutter threads.
The correct hole diameters are:
Copal 0 - 34.8mm
Copal 1 - 41.8mm
Copal 3 - 64.2mm (has no anti-rotation pin)
The shutter hole should be bored (not drilled) by a machinist, or finished by someone with the proper tools to ensure that it's round, not scalloped.
Some suggestions for mounting shutters:
1) Open the shutter blades using the preview lever.
2) Open the aperture fully using its control lever.
3) Remove both front and rear cells. Be careful to locate and save any shims that might be present.
4) Whenever possible, hold the shutter with its threads downward, to prevent junk from falling into it.
5) Make sure the pin is seated and the retaining ring ledge is in the mounting hole before tightening.
6) Remount both cells (with shims if present).
nb - NEVER put your fingers or anything else in the shutter throat. You could damage the blades.
If you need an anti-rotation pin, you can buy one for $1 from SK Grimes http://www.skgrimes.com
Last edited by Leigh B; 06-19-2011 at 06:47 PM. Click to view previous post history.