Cooke IIe SF Lens lubrication ?

[CCHarrison]

I am preparing to sell a minty IIe but the softening mechanism is stiff. Has anyone dealt with this issue or should I send in to a repairman ?

Thanks
Dan

[E. von Hoegh]

I'm not familiar with that lens. However, whatever the mechanism is, it needs to be disassembled cleaned and reassembled with a lubricant that will not outgass and haze the glass surfaces.

[bobherbst]

I had the same problem with a 13" version last summer. A web search sent me to this thread which happened to be on this forum - http://www.largeformatphotography.info/forum/showthread.php?t=47096 from 2009.

See Jim Galli's comments on the second page. Using his advice I did just what he suggested, except I used automotive brake cleaner. It cuts oil and grease and leaves no residue. I figured there wouldn't be any plastic in a 100 year old lens - just brass and glass.

I removed the front and rear elements as Jim suggested. Then I sprayed some brake cleaner into a film can and used a glass eyedropper to flood the threads of the soft focus ring. At first the ring didn't move, but when I poured out the brake cleaner, it was very dark - dissolved old lubricant. It took probably a dozen times of flooding the threads and working the ring back and forth, but eventually the liquid came out clear and the ring moved freely. After all of the residual brake cleaner had evaporated, I put one drop of a pure silicone at the edge of the ring and let it wick into the threads and dry.

I never saw any liquid inside the barrel or on the center piece of glass. The brake cleaner did not dissolve any of the lacquer on the lens barrel, and I have seen no "hazing" of the glass as a result.


I am preparing to sell a minty IIe but the softening mechanism is stiff. Has anyone dealt with this issue or should I send in to a repairman ?

Thanks
Dan

[goamules]

Dan, have you tried a little Naptha? It sure works for some of the smaller lenses I've had that have stuck moving parts....

[CCHarrison]

Well, after warming up over the last 24 hours inside my home, the SF adjustment is working ok now.... Thanks for all the tips

Dan

[Louis Pacilla]

Hey Dan

I have cleaned and lubed my 15" IIE and it's very simple and straight forward. everything goes back in place easily and special tools needed.

I'll post a few digi pics as they may help.

The hood holds the SF sections together. The screw in last photo is one of three that run in groves this keeps the entire mechanism moving in proper position. Only one of the three sticks out for the outer tube to run in. This is the screw that forces the final position before re attaching the hood. Again, the hood locks everything back in proper position for final use.

ask questions if you have them.

It really is simple to clean and lube. It's sooooo smoooooth and silky to use now. Well worth the little time it takes.

Here

[Louis Pacilla]

a few more snaps. The grease showing the temp in which it begins to break down.

The channel in outer barrel that the protruding screw slides in.

The last two are of the click stop groves and the bearing which I applied grease. I wipe all access grease off before reassembling.

[CCHarrison]

Louis..

Great posts ! I noticed the interior element needs cleaning. How do you take the front element off to reach the front of the interior element? Does the entire front hood need to come off ?

Best
Dan

[Louis Pacilla]

Hey Dan The front cell will come out with ease.


I added a quick shot of front cell so you can see it's position for removal. Just make sure the SF is set to "Sharp". This is so that the cell is as far forward as it will go.You can see the slots for the spanner wrench. You can either grab it with rubber pad to get a grip or use your spanner wrench if needed.


All three cells are very easy to remove, even the center cell. That said ,it can be reached and cleaned in it's original position. I would remove the center cell if you are going to lube the the SF feature just to be safe.

[E. von Hoegh]

Hey Dan

I have cleaned and lubed my 15" IIE and it's very simple and straight forward. everything goes back in place easily and special tools needed.

I'll post a few digi pics as they may help.

The hood holds the SF sections together. The screw in last photo is one of three that run in groves this keeps the entire mechanism moving in proper position. Only one of the three sticks out for the outer tube to run in. This is the screw that forces the final position before re attaching the hood. Again, the hood locks everything back in proper position for final use.

ask questions if you have them.

It really is simple to clean and lube. It's sooooo smoooooth and silky to use now. Well worth the little time it takes.

Here

I'd enjoy having one of those, even if I never made a photo with it - just for the craftmanship that went into machining it.:)

[Steven Tribe]

Dear Louis!
Just a public thanks for taking the time to post the photos, which was of great help in cleaning out the interior lens surfaces.
Perhaps I should also add the the 3 pins which transfer the twist into movement are attached to loose nuts in the inside between the front and central lens so these are best not touched! Cleaning the rear surface of the middle lens through the rear past the iris is quite easy.