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Lightbender
26-Dec-2018, 17:45
I have a lens mounted in a linhof recessed lens board.
I want to move it to a standard flat lens board. Unfortunately I find it is impossible to unscrew the shutter retaining ring.

Before I try to brute Force it more than I already have, I am wondering if it is normal for linhof to cement or weld these things on.

I added a little bit of lighter fluid to try to see if I can free up the ring. Any other ideas?

Bob Salomon
26-Dec-2018, 17:49
No. They donít.

Keith Pitman
26-Dec-2018, 17:53
Put it in the freezer overnight and try it in the morning. The metal will “shrink” and you should be able to turn the retaining ring. You do have a proper lens wrench don’t you? If not, get one before you mess with it (e.g., mess it up).

Leigh
26-Dec-2018, 18:13
Are you really trying to unscrew the retaining ring, or trying to unscrew the shutter body itself?
That requires removing the rear lens cell to access the retaining ring, and perhaps a special wrench.

Many shutters had an anti-rotation screw which will not allow the shutter to rotate at all.

- Leigh

Greg
26-Dec-2018, 18:17
Very, I mean very minimal (2 drops?) application of WD-40 and let it rest overnight. Striking one side of a spanner wrench with a very small ball peen hammer very gently should loosen the retaining ring. When it comes apart, wipe off the WD-40. If you don't own a spanner wrench, just get one on eBay for very little money, you will definitely never regret that purchase.

Bernice Loui
26-Dec-2018, 19:02
WD-40 is not penetrating oil, this is not the oil to use when metal bits are stuck. Use a proper penetrating oil like Liquid Wrench, PB blaster or similar as these are proper penetrating oil that WILL help loosen stuck threads and similar.

The procedure would be to moisten a Q-tip or similar cotton swab with proper penetrating oil. Then carefully dab-swap the P oil at the gap between threaded parts only. Do not allow the P oil to come in contact with any of the glass lens elements.. Allow the P oil to soak in for at least 24 hours or more (re-apply P oil) before any attempt to loosen the retaining ring with the correct spanner wrench.


Bernice

Jac@stafford.net
26-Dec-2018, 20:26
Are you really trying to unscrew the retaining ring, or trying to Lwunscrew the shutter body itself?
That requires removing the rear lens cell to access the retaining ring, and perhaps a special wrench.
Many shutters had an anti-rotation screw which will not allow the shutter to rotate at all.

- Leigh

What Leigh wrote! Take it seriously IF there is a forward facing pin. And regarding WD-40, just forget it. Its only virtue is to displace moisture. It is not a penetrating solvent.

--
Jac who has disassembled too many old, frozen mechanics.

EDIT: Ma faut - I see that Bernice Loui mentioned this already. I will add that a lens board is the least important part and I have used a saw or snips to slice the board to liberate a precious lens.

Jay Wolfe
26-Dec-2018, 20:26
Put it in the freezer overnight and try it in the morning. The metal will “shrink” and you should be able to turn the retaining ring. You do have a proper lens wrench don’t you? If not, get one before you mess with it (e.g., mess it up).


I would give Keith’s suggestion a try. It has worked for me before. It’s not invasive and can do no harm.

Bob Salomon
26-Dec-2018, 21:17
Got to ProShop for Photographers in West Palm and they can solve your problem.

LabRat
26-Dec-2018, 21:18
So there is a slotted retaining ring around the rear element area??? Those often have a anti-rotation pin under back shutter body, meaning only the ring will rotate off, requiring proper spanner...

Check to see if there is 3 or 4 screw ends inside board where a bolt flange is screwed or riveted to the front of the board... These are screwed to the lens, and shutter is unscrewed from the front by rotation (Linhof factory boards are often mounted this way...)

Some retainers from some makers have a tiny drop of threadlok drop on them... Look carefully for the tiny bead of it, and if found, a hypodermic needle with a tiny drop of acetone is applied, wait a few minutes, repeat, then spanner again while soft...

Steve K

pjd
27-Dec-2018, 05:39
Lighter fluid isn't the worst thing to try in this situation. Just this week I freed up the soft focus thread on a black barrel Dallmeyer which had lain unused for decades (judging by the dirt) with lighter fluid. I didn't have high hopes of success but a tiny amount in the threads, a bit of patience with a strong grip and it freed up nicely. Brute force isn't a good idea, be patient. Or take it to a shop with proper tools.

tonyowen
27-Dec-2018, 06:51
spanner wrench .
For clarification what is meant by 'spanner wrench'
In North America a wrench means a tool with an across flats opening [or ring end] to tighten or undo a particular sized screw/bold or nut.
In the UK a spanner is used to tighten or undo a particular sized screw/bold or nut. Again the size of the spanner relates to the bold/screw/nut being handled and the spanner can be open ended (works on the across flats of the screw/bold/nut Or a ring that works on the corners of the hexagonal screw/bolt head or the nut.
individually the words Wrench and Spanner are names used in different countries for the same device
Is a spanner wrench something else?????
regards

Tony

Dan Fromm
27-Dec-2018, 06:54
Tony, see http://skgrimes.com/products/spanner-wrench

Randy Moe
27-Dec-2018, 08:27
When using spanner be careful as it can slip.

Which may destroy aperture and shutter blades.

A possibility is puncture wound.

A slip may scratch a lens.

Been there done that :)