Retaining ring stuck on Horseman board

[hervedemers]

Hi everyone. I have recently bought a Nikkor 90mm f8 on eBay that came on a Horseman board (my camera uses Linhof type). In the past, I never had any issue unmounting a lens from a board to change it myself, with the proper lens wrench. This time, it's completely stuck. I've tried heating the ring with a hair dryer, forcing it really hard, without any success, except by adding awful marks on the ring itself. I'd love to have your advice on this :(215659215660215661

[Ari]

Hervé, I've sometimes found that by trying to turn the larger piece (lens board or shutter) and stabilizing the smaller piece (retaining ring), that things sometimes loosen up.
Maybe add some penetrating oil, but make sure it drips away from the shutter.
Good luck, let us know if you manage to get it off!

[hervedemers]

Hey Ari! Glad to see you here. Unfortunately, I've tried the freezer, tried holding the wrench to stabilize the retaining ring, it's still stuck. At this point, I'm afraid to put any liquid in there and thinking I should bring it to a repair shop. Do you know any good one you'd recommend in MTL for large format?

[Tin Can]

It must be glued

some did that, making us rely on experts

[hervedemers]

Thanks Tin! So you think my best option would be to find a repair shop that does LF lenses?

[Tin Can]

Most likely if you want

I never use expert repair and consider any mistake I make a valuable lesson

I prefer to buy the right tool, DIY

You have the right tool and obviously have tried very hard

solvent is next


Thanks Tin! So you think my best option would be to find a repair shop that does LF lenses?

[Jim Noel]

Unfortunately your wrench is too flexible to do the job as evidenced by the marks left when it came out of the grooves. It's too bad the best lens wrenches are no longer made. The best alternative today is one made of heavy steel with teeth appropriate for several rings, like a Rodenstock.

[John Layton]

Maybe start with boiling water...and try your retaining ring wrench - and if no go...try using something like a rubber jar-top gripper and do your best to use equal force around the circumference of the ring...maybe with the board itself mounted in a vice. Whatever you do, do not mount the ring in a vice...as then the forces would only squeeze the ring further and make things worse.

For stubborn filters, I sometimes find that an old length of electrical cord...wrapped around and gathered as a "handle" on one side - gives a good, strong, even grip. Not sure if a cord would fit the height of your ring, though.

If the boiling water does not work...maybe then go to a solvent of some sort - perhaps "PB-Blaster" like what I use to help undo rusted/corroded nuts and bolts on my car. If this does not work...you can take this outdoors - heat things up with a propane torch (not enough to get red hot!) - and apply some PB Blaster which, as the assembly cools, will get drawn further into the threads. Just watch yourself when you do this...as you may have a bit of a fire to deal with!

[hervedemers]

@Tin Can : What solvent would you recommend? I've tried adding a bit of my girlfriend's nail polish remover (which is mainly Acetone), but it did not move. Maybe I did not add enough, but I'm afraid it will go into the shutter.

@Jim : Thanks for the tip! I have one too, which I preferably use, but have you noticed the protruding metal ring on the back of the Horseman board around? I cannot get the teeth of that Rodenstock lens wrench inside the grooves like they should because of it. It's driving me crazy.

[hervedemers]

@John Layton : Thanks a lot John! When you say boiling water... you mean add drops of boiling water onto the outer threads where the ring is attached?

[Tin Can]

I am very careful with any solvent

I once looked up and my girlfriends Afro was on fire

I had to run around a shop bench and put it out before she realized

She was OK

I have seen too may accidents

[Ari]

Hervé, if you need to send it to a repair guy, the one I use is in Quebec City.
Call René: http://www.servicecamerapro.com/e-home.html

But I would keep trying at home first.
I think you need a tool more suited to this job. I'd take a good-sized piece of wood, and drive two nails through it that correspond to the spacing of the slots in the retaining ring.
Then I'd get a large thick rubber band (or jar opener) and hold the shutter with that while apply the torque to the ring with the two nails.
Here's a drawing of what I mean:
215671

[Sal Santamaura]

...You have the right tool...


...It's too bad the best lens wrenches are no longer made. The best alternative today is one made of heavy steel with teeth appropriate for several rings, like a Rodenstock.

You guys are both wrong. Jim on both counts.

I've had the same struggle with retaining rings on Horseman field camera 80mm square lens boards, of which I have many for my VH and FA cameras. First, the Rodenstock wrench won't work because it's too wide to fit inside the circular light trap ring on the back of the boards, and therefore its teeth won't seat in the ring's slots. Second, the OP's pointy wrench is unsuitable for wider slots in Copal retaining rings like his Nikkor's. Finally, the wrench that's needed is still available for purchase brand new. It's the flat tip version from S.K. Grimes:


https://skgrimes.com/products/spanner-wrench/

That one always works for me. It will for you too, Hervé.

[Tin Can]

Sal, the tool I have, similar to OP is pointy on one end and flat blades on the other

The SK Grimes issue looks good

I will buy one

[hervedemers]

@ Sal Santamaura : Thanks a lot Sal. Do you think it'd be that different from the flat tips I have on my actual wrench? 215675

@ Ari : Looked like a great solution, but it failed once again. My wrench is good enough to stabilize the retaining ring like the nails would, but the problem is that my Compur 0 shutter doesn't have a clear grip for my hands around it, even with a rubber band, because there's always a small button in the way. I was forcing it again really hard with a rubber band around the shutter and the wrench tightly in place, but it doesn't move. And it's great you suggest René, I know him really well. He still works in my hometown and I always thought he was the best. It's just a little far from Montreal now ;-)

[Ari]

Too bad it didn't work, Hervé.
Maybe the lens wrench Sal suggested will work.

[seall]

Put the board in a vice so it is horizontal and gripped on two sides, the shutter facing down.

Pre–tension the wrench so it is a really tight fit and lock the thumb screws with pliers. It may help if before you tighten the screws you force the bottom legs of the wrench outwards and the top inward then tighten the thumb screws.

Use the center flat side of a large spanner for leverage inserted between the back of the lens and the first bar of the wrench. Do not use the end of the spanner on the wrench, you want to distribute the force equally to both sides of the wrench.

Grip the wrench and spanner very carefully with both hands simultaniously whilst applying the force to the spanner as far as you can comfortably from the center of the wrench with both hands, a little downward force may help the wrench stay located but not too much.

If possible have someone else hold the shutter from underneath with a steady tight grip, even better if a little force is directed upward against the board to give a little extra resistance to spinning.

If you can keep the wrench perpendicular and steady with your thumbs then your hands will be able to get a good grip of the spanner on each side to give far more force than the wrench alone will give you but the board will have to be locked in a vice solid for you to get the best from this.

Please note, using a spanner in this way is considered very bad practice and due to H&S rules is illegal in some workshops. If you are take your time and are carefull it may help you loosen the ring.

[Sal Santamaura]

@ Sal Santamaura : Thanks a lot Sal. Do you think it'd be that different from the flat tips I have on my actual wrench? 215675...

The images you attached to the original post didn't make clear that there were flat tips on the other end. I'm unable to determine how thick they are from this image. However, the wrench doesn't appear quite as rigid or easy to hold securely as the Grimes wrench is.

I just fit my Grimes wrench to a Nikkor Copal 0 retaining ring. The flat tips are a bit more than 1 mm thick at the top of the ring's quarter-circle slots. They fill around 85% of the slots' width at the top of those slots. I guarantee nothing, but suspect the Grimes wrench would be much more successful at breaking the ring loose without further damaging it.

One thing that might make the task easier, whether you try again with your wrench or get a Grimes version, is to stop holding the shutter in one hand and the wrench in another. Rather, place the lensboard (horizontally) in a bench vice, supporting the shutter below so the only force that vice provides is against lensboard rotation around a vertical axis. Then use both hands to simultaneously apply down force and counter clockwise force on the wrench. Good luck!

Edit: seall posted while I was composing. I don't recommend going as far as using a "breaker bar." Otherwise, great minds think alike. :)

[hervedemers]

Thanks everybody for the thorough replies. I really appreciate the help from everybody. As my access to the tools mentioned are somewhat limited at the moment (vice, large spanners, or more expensive wrenches I might only use once), I'll try to see if a local repair shop would be able to help.

[abruzzi]

while I'd be a little concerned about dirt/oil infiltration, if you don't have a camera repair place locally, this is the sort of thing that a local machine shop could probably fix in 30 seconds, and machine shops are far more common than camera repair.

[Ernest MacMillan]

215724 In my experience, I seem to need two hands to properly hold the wrench and one to hold the work. The illustrated wrench, freely available from Japan and about $30, works better for me than some of the others mentioned.

If you are truly desperate, you may clamp the board to a table using wooden spacers or a wooden ring and clamps to protect the shutter, and use a broad flat screwdriver and a small hammer to tap the ring along (electrician's solution).

For about $100, you can buy a horseman adapter, the older ones from Japan usually work best, and just go with the flow.

[Bernice Loui]

More than the spanner wrench. Yes a good quality spanner wrench can make a real difference for dealing with lens retaining rings. Best of the commonly available spanner wrenches was sold (made?) by Horseman. The spanner wrench arms are forged steel with alloy steel tips that are held into the arms by screws. If this spanner wrench cannot remove retaining ring, the retaining ring is seriously stuck.

Horseman spanner wrench next to the common flat plate spanner wrench that works 90% of the time.
215737


Second and more insidious problem is friction and galling of aluminum threads. Galling or essentially aluminum threads getting "married" to each other is common. The anodizing sort of helps but also can make galling worst due to the unpredictable finish of the anodizing that can behave like
two rough surfaces producing lots of friction together making un-threading extremely difficult. This is where penetrating oil like Liquid wrench and similar can make big differences. Suggest swabbing the stuck threads with penetrating oil via a Q-tip to prevent applying too much penetrating oil and causing an oil slick on the optical parts involved. Allow the penetrating oil to work for hours to days, then try removing with a good quality spanner wrench.

Heat can work, problem being these precision and delicate optical bits are often heat sensitive.


Bernice