Help --- Stuck Retaining Rings

Old-N-Feeble · Aug 22, 2014

What do you folks do to loosen very stuck retaining rings? I have a good spanner wrench but sometimes I must give up trying to loosen the terribly stubborn ones. The one giving me problems now is one of those ultra-thin Copal #00 rings with very tiny slots. I've already marred the back of the lens board and the ring. Things like this frustrate the heck out of me. I do stop before I get really ticked off and mess up the lens... learned that the hard way long ago.

Ken Nadvornick · Aug 22, 2014

I have a small flexible strap wrench that is often my last resort, depending on the geometry of the stuck item...

Ken

Old-N-Feeble · Aug 22, 2014

Ken Nadvornick said:
I have a small flexible strap wrench that is often my last resort, depending on the geometry of the stuck item...

Ken

You use the strap around the shutter body? I'm afraid I'll break something. Also, I don't know if there's an anti-rotation pin installed. This is an older lens... 135mm Repro-Claron in Synchro-Compur. Sorry I didn't mention that.

Ken Nadvornick · Aug 22, 2014

I'll carefully use it around pretty much anything. "Carefully" meaning, only a common sense amount of torque for whatever I'm trying to loosen, since it's really easy to go overboard with a strap. If the geometry means I can get a solid wrap without damaging anything, I'll gently try it. If it still won't give with reasonable force, then I abandon the attempt as the last chance end of the line.

Straps are designed to symmetrically distribute the gripping friction around a circumference, so less, not more, chance of damaging the item. Think of asymmetric alternatives like pliers or vice grips. Or spanner wrenches. Set pins are another story entirely...

Ken

Old-N-Feeble · Aug 22, 2014

I've tried turning the shutter with my bare hands and it won't budge. Of course a strap will provide far more leverage. I'm afraid I'll break something. I may just Dremel the ring off. That's tricky too though.

Newt_on_Swings · Aug 22, 2014

Maybe with the rear cell off try a rubber sheet and use something that's roughly the same diameter of the ring, lots of pressure while turning. I've scratched and gouged a few rings and boards myself with tight lenses. You don't need to tighten that much, I'd rather use that set screw to keep lenses in position.

Old-N-Feeble · Aug 22, 2014

Newt_on_Swings said:
Maybe with the rear cell off try a rubber sheet and use something that's roughly the same diameter of the ring, lots of pressure while turning. I've scratched and gouged a few rings and boards myself with tight lenses. You don't need to tighten that much, I'd rather use that set screw to keep lenses in position.

I think this lens was mounted by Linhof. It's mounted on a mini Linhof Technika board and came in a Schneider box sized to the board. I do hate to mar the board but I need the lens on a 4x5 Technika board. I never tighten lenses this much even without the anti-rotation set screw.

aRolleiBrujo · Aug 22, 2014

use a rubber band around the circumference.

Jon Shiu · Aug 22, 2014

If you can, grip the spanner with a large wrench for leverage. Hold the lensboard in a vise.

Jon

ic-racer · Aug 22, 2014

Heat. I place stuck stuff on my print dryer. Then I use rubber dishwashing gloves for both insulation and grip to unscrew stuff. For just about anything with threads, when it expands the threads loosen.

shutterfinger · Aug 22, 2014

Apply a few drops of penetrating oil on the shutter at the retaining ring and let it set for a few hours.
Clamp the lens board in a secure bench vise using blocks of wood to prevent marring the board and clamp it by the edges of the board.
Using your best spanner and both hands unscrew the retaining ring.

I have this strap wrench set, http://www.sears.com/craftsman-2-pi...0000037223911P?prdNo=2&blockNo=2&blockType=G2 and often just wrap the rubber strap around the stubborn item and grip the rubber without using the handle.

Old-N-Feeble · Aug 23, 2014

Thanks for all the excellent suggestions. I'll give them a try later when I'm in the right frame of mind.

John Koehrer · Aug 23, 2014

A piece of PVC pipe that will slip over the barrel with contact cement(dried) or other grippy stuff on the surface may give enough grip on the ring.

Sirius Glass · Aug 23, 2014

aRolleiBrujo said:
use a rubber band around the circumference.

This has worked for me.

Help --- Stuck Retaining Rings

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