retaining ring too tight [Archive] - Large Format Photography Forum

kunlun121

8-Dec-2023, 08:50

Recently I bought a really nice Grandagon 155 f/6.3. It's on a Technika board and I want to move it to a Sinar board. The retaining ring fixing the lens to the board is so ridiculously tight that I can't begin to loosen it. I am using the tool pictured here.

244591

When the metal of the tool starts to flex I stop. Don't want to break it.

What kind of tool allows you to put more force on the ring?

Ulophot

8-Dec-2023, 09:41

I am not a mechanistically inclined person, so don't necessarily take this advice. but I wonder if either a touch of thin lubricant or using something like a small tacking or soldering iron briefly to heat the retaining ring might loosen it up.

domaz

8-Dec-2023, 09:47

kunlun121

8-Dec-2023, 10:13

I am hesitant to apply liquids to the thread as I'm worried it may enter the cells. Same for applying heat - not sure it's low risk enough for me to try. Maybe I should have a professional look at it.

jim_jm

8-Dec-2023, 11:28

If this is for the lock ring on the back side of the lens board, I'd first try a bit of anti-seize or break-free lubricant on the outer edge of the ring, where it contacts the board. Several drops shouldn't get into the lens. Let it soak in for awhile and try again. If that doesn't work, a proper lens spanner (https://www.micro-tools.com/collections/camera-repair-tools/products/spb) will allow for more leverage. Sometimes these rings can get really tight over several decades.

rfesk

8-Dec-2023, 15:40

I had that problem. I purchased one that has pins that fit the slots in the ring. Was able to apply my efforts very close to the ring. Very stressful on a new (to me) lens that costs hundreds.

domaz

8-Dec-2023, 16:28

If the lens is attached to the lensboard I often find moving the lensboard around while keeping the lens and retaining ring in place is more effective than anything else. Removing a stuck retaining ring on a lens without a lensboard is very tricky.

MartyNL

8-Dec-2023, 17:17

I had a similar problem with a Sinaron 210mm on a sinar board and gave it to the Sinar specialist at the time. They separed the shutter and lens board but only at the expense of shearing the copal shutter threads completely off. We agreed to go halves on a new shutter.

What I'm trying to say, is that it might not be possible but I hope you have better luck than I did.

I quite like the idea of applying localised heat via a tacking iron, hadn't thought of that...

paulbarden

8-Dec-2023, 18:16

Can you see any signs of a matte black paint-like substance in the vicinity of the ring? I have dealt with a number of shutters, and I sometimes find that a previous technician has used a matte black lacquer to "lock" a ring in place. If you see any of this, it's worth trying to soften it with the careful application of Acetone to the ring area, let it sit a couple minutes, reapply, and then try your spanner. I use tweezers, dipped into acetone, to pick up a small amount and then I can carefully place it where I want.

kunlun121

9-Dec-2023, 02:30

Thank you for all these great suggestions. Last night I ordered a proper spanner wrench like the one @jim_jim suggested. If I replace the horizontal rods with much longer ones I’ll be able to exert much more torque with ease. Meanwhile I’ll examine the ring’s edges for loctite or other gunk. That would really be criminally negligent, hopefully I’m spared that ordeal. In another thead here I found people suggested the miracle substance named WD-40, which I may give a try if the ring has not been glued. As a last resort a dremel may be able to save the thread of the shutter if I cut through the lens board. I’d really hate to lose this Prontor Professional.

MartyNL

9-Dec-2023, 03:59

As a last resort a dremel may be able to save the thread of the shutter if I cut through the lens board. I’d really hate to lose this Prontor Professional.

Wise decision. Although gnawing through the retaining ring might be on its own, sufficient.

MartyNL

9-Dec-2023, 04:07

I will admit, that I found my one 'welded' retaining ring episode so 'traumatic', I've taken to asking about being able to remove lenses from lensboards, before all future purchases! :)

kunlun121

10-Dec-2023, 11:11

OK, so mine has not been glued. I am going to try with some WD-40.

rfesk

10-Dec-2023, 12:34

The spanner I used was very similar to the one suggested by jim_jim. Once the blades are fit into the grooves of the filter ring, hold them tight to the ring with your fingers down close to the ring and then twist.

It worked for me but I was very careful not to damage anything if the blades of the spanner slipped out of the grooves. Not sure I would use WD-40.

Mal Paso

10-Dec-2023, 12:35

OK, so mine has not been glued. I am going to try with some WD-40.

Yikes! WD 40 is not a lubricant although it sort of acts like one until the solvent dries.

A drop of 10 wt oil like ATF would be better. ATF and acetone 50/50 is the best penetrating oil period. Automatic Transmission Fluid, not synthetic.

kunlun121

11-Dec-2023, 00:08

Yikes! WD 40 is not a lubricant although it sort of acts like one until the solvent dries.

A drop of 10 wt oil like ATF would be better. ATF and acetone 50/50 is the best penetrating oil period. Automatic Transmission Fluid, not synthetic.

That is a great suggestion, thanks.

EDIT: wait, does it have to be ATF of can it be any 10W mineral (i.e., non-synthetic) oil? Does the stuff they add to ATF make it more suitable as penetrating oil when mixed with acetone?

jnantz

11-Dec-2023, 03:54

... last time I had this problem I shipped the gear back to the seller because neither I nor my repair person could access the shutter to do a CLA ..
before manhandling the lens it might be worth deciding if it is worth damaging the shutter, board or glass ( if things go sideways ).. there's a lot of lenses out there to be bought that might not have this issue ..
that said, if the spanner wrench you purchased doesn't have mass / strength
to transfer your force, SK Grimes sells spanner wrenches that have heft to them, and transfer torque really well..
(as I did ) it might be worth taking the lens to a repair person who might have a bench lens vice .. or at least the right expertise, solvents / routine to do the job without damaging the lens...

xkaes

11-Dec-2023, 08:07

Someone may have put thread locker on the threads or you have a bit of corrosion going on. Using some sort of anti-seize lubricant in small quantities might work. If it's mounted on a lensboard you could put the lensboard in a bench vise to get more leverage.

I'm in a similar situation -- I think someone used some glue to keep a lens on a shutter. I can't get it to budge -- even with a pipe wrench. Take a real close look at the thread on the lens and see if you can spot any glue/goo. If that's the case it might be super-glue or epoxy. There are ways to loosen that. Also check for rust. Report back.

xkaes

11-Dec-2023, 08:11

Chuck Pere

11-Dec-2023, 08:13

Can't you just unscrew the front and back lenses? That would prevent any glass damage.

xkaes

11-Dec-2023, 09:23

I assume the OP has already done that. On his lens that is probably mandatory -- at least for the rear glass.

In my case, I can't remove the rear glass -- but the shutter is NOT on a board -- and I'm wondering if it is glued in place to the shutter. With what I don't know.

I'm going to try everything -- when I have the time.

Mal Paso

11-Dec-2023, 10:11

If you are mechanically inclined and not risk adverse...

If you have access to a vise that opens to 4 inches place the Technika board horizontal in the vise clamping by the 2 parallel flat edges. Find a slotted screwdriver with a tip that fits the slot in the retaining ring well. With the screwdriver tip pointed in an Anti-clockwise direction find the best angle to contact the the retaining ring slot fully and still push the retaining ring in an Anti-clockwise direction and tap the back of the screwdriver with a small hammer.

Jim Noel

11-Dec-2023, 10:28

You won't be able to apply much more torque with the wrench you bought,They flex too easily.
I have a heavy duty one which cost me about $150, 40+ years ago that I don't see advertised today.
Paul's method is a rather good one.

kunlun121

28-Dec-2023, 06:40

Just before the holidays I picked up the lens from one of the two optical/mechanical specialists left round my neck of the woods. Turns out the ring had not been glued, just overtightened. But the front element has been glued into the shutter. That's why this:

Can't you just unscrew the front and back lenses? That would prevent any glass damage.

didn't work.

Shutters speeds checked out accurate and repeatable, so he didn't bother trying to get the front lens out of the shutter for now.

I wonder how these lenses end up in the hands of people who would (i) maltreat it like this one, and (ii) not disclose the maltreatment referred to under (i) at the time of the online sale. Apparently it pays off these days to draft elaborate questionnaires to get the seller to disclose all kinds of ridiculous defects before buying.

The mechanic who handled my lens showed me the spanner wrenches he used. They are vintage and Canon-branded - from back in the day when he worked at Canon. They are relatively small but heavy and flat, so you can grab them with pliers if you need to exert more force. Have looked around for these but came up with nothing. All you really need to apply more force is a longer lever.

I found this tho, which looks good for that reason: https://www.micro-tools.de/en/Lens-Tools-oxid/Spanner-Wrench-Lens-Ring-Tool.html. Anybody have any experience with this kind of spanner wrench?

xkaes

28-Dec-2023, 07:40

jnantz

28-Dec-2023, 09:01

It's amazing what some people do to their gear -- but they probably don't think they are abusing it. They probably think they are "helping" in some way -- and have no idea that they are really creating a problem in the future.

I was able to solve my "glued lens" problem, but not in the best way.

all you need is a little black India ink and some clear nail polish to fill in the gashes works every time ! ;)
and then some oil from behind the air if that doesn't work ;)

I have a travel clock I took apart years ago, I didn't realize the main spring was seized and over wound and when I took the last screw out it went S P R O I N G and I wasn't able to stick everything back in ... I shoulda had some crazy glue, it would have helped ;)

Jim C.

28-Dec-2023, 18:19

I found this tho, which looks good for that reason: https://www.micro-tools.de/en/Lens-Tools-oxid/Spanner-Wrench-Lens-Ring-Tool.html. Anybody have any experience with this kind of spanner wrench?

I don't have experience with that particular style wrench but I have used similar pin spanner wrenches
when I service my metalworking machines. To me those are preferrable over the H style wrenches
you can get a better grip and don't have to deal with torsion issues with the H style on stubborn rings.
The only issue would be the length of the pins relative to the depth of the retaining ring.

I don't suppose you took any snapshots of those old Canon tools ?
It would be interesting to see them.

JimC

Kevin Crisp

28-Dec-2023, 18:55

Dugan

28-Dec-2023, 19:22

It's amazing what some people do to their gear -- but they probably don't think they are abusing it. They probably think they are "helping" in some way -- and have no idea that they are really creating a problem in the future.

I find that kind of thing in photo equipment that somehow survived the Great Depression...
The 'order of the day' was "Make do, or do without", and "Necessity is the mother of invention".
Socks were darned, Model T's were converted to sawmills, etc.
Twine, wire, glue, tape..whatever it took to fix things cheaply.

John Layton

28-Dec-2023, 19:25

First, an electrical cord wrapped around the retaining ring to apply even pressure to remove it.

If that does not work...heat up the retaining ring enough to melt wax and let the wax infiltrate the threads as it cools. Then remove the ring.

If that does not work...use a Dremel tool with a small drill to make a hole in the side of the retaining ring to weaken it.

If that does not work...then use a cutoff wheel on the Dremel to slice through where the drilled hole is.

Basically, do what you can to sacrifice the retaining ring.

kunlun121

29-Dec-2023, 02:48

The SK Grimes wrench (with flat tips) is something I have used over and over again with complete satisfaction. I think I've had it around 20 years, or more. It has also more than paid for itself by giving me a way to change my watch batteries.

Yes, I found this after my debacle with this lens and am in touch with them to have one sent over. Looks decent.

kunlun121

29-Dec-2023, 02:50

I find that kind of thing in photo equipment that somehow survived the Great Depression...
The 'order of the day' was "Make do, or do without", and "Necessity is the mother of invention".
Socks were darned, Model T's were converted to sawmills, etc.
Twine, wire, glue, tape..whatever it took to fix things cheaply.

Sure. But the glueing of the front lens group into the shutter would seem entirely unnecessary and thus be an invention that was uncalled for. Additional work for no clear benefit. Hand tight will serve almost all real-world photography purposes just fine.