Help please: How to remove a ring from Copal #0 shutter?

[rogerxnz]

I have a Skink pinhole holder which is designed to screw into a Copal #0 shutter. I have one of those shutters but there is a black ring on the front of the shutter and inside the ring engraved with the shutter speeds which I need to remove first. Please see the attached photo to see the ring.

The ring turns freely but does not appear to be threaded. I have tried to lever it off but moderate force had no effect.

Does anyone know how to remove the ring? Would undoing the screw shown in the photo help?

Thank you in advance for any assistance.
Roger

 

[Sirius Glass]

That screw has a flat side for a reason. Turn it 180 degrees so you can unscrew the shiny wavy ring.

After turning the screw if the ring does not turn, wrap a rubber band around the ring for hand gripping to unscrew the ring.

 

[Dr Croubie]

Just make sure you work with the aperture and shutter fully open.
Screwdrivers slip. Ask me how I know.

 

[rogerxnz]

Solution!

Thank you all for your advice.

I got the chrome scalloped ring off and the lens apart and I eventually found that none of that was necessary because the ring I needed to remove was not affected by anything internal.

It was held in place by little ridges at the internal ends of the "teeth" going inside the shutter. It was just a matter of levering one of the teeth away from the sides of the outer ring with the engraved shutter speeds, rather than trying to force the ring off directly, and the offending ring popped out.

See the attached photos for closeups of the ring in place and of the ring removed to show its internal "teeth".

The photos have been "enhanced" to show details. Both rings are normally solid black.

Hope this helps somebody!
Roger

 

[wildbill]

Maybe i'm the only one to have removed the plastic ring but THERE IS NO NEED TO REMOVE ANY SCREWS to do this. Glad you figured it out w/o any damage. I have one of the pinhole plate holders too.

 

[EdSawyer]

Yup, just a trim ring. Some regular lenses also need this removed when mounting into a copal 0 shutter. Apo sironar S for example. Easily popped out as you figured out.