Cleaning of slow shutters

[LabRat]

About this spring thing...

If a leaf shutter is cocked, yes the springs are under greater tension, but more important is the fact that the unfired/cocked shutter linkages and release catches are now under more strain, most are pretty thin soft metals that are much more likely to distort/deform under tension and the more or less worn catches/locks (that release to transfer energy) are sitting with considerable tension/force at that (small) point or area... (Kind of like keeping an air rifle cocked... The spring does it's thing compressed inside, but we can hope that the rest of the components inside are not under too much more strain, so it makes sense to leave it un-cocked...)

The spring with the greatest tension is the cocking spring... This has some overtension so if the shutter has some resistance (from cold, lube issues, oxidation, etc), it still has considerable force to push everything along, but the timing mechanisms are fairly independent to allow the shutter to open and close at the right times, but being cocked, it is putting quite a bit of extra pressure/tension on the catches/locks...

The other big reason to keep the shutters un-cocked is that they are sitting at the best reset point at rest... The slow speed escarpment is fully at it's starting point (left set at the slowest speed, it is fully at it's full rest/reset position), the flat drive plates/linkages that drive the blades are not held back under tension (possibly distorting/wearing catches, etc), shutter cocking and release points are not holding back considerable force (like a mousetrap), and by the initial cocking, most all of the entire mechanism gets a little push, so there is a little exercise for everything and arms/slides/pivots move a little to break their at-rest seating etc...

If you dug through your old worst shutters, and had left one cocked in storage, you might release it only to find it releases (or not), but only partially opens, not opens, sluggish blade action, or barely or not close at all... Low speeds might be sticky due to the # of tiny pivots in the escarpment slightly sticking to their bearing seats before morning exercise, etc... But un-cocked at least most everything inside gets moved a little initially (during cocking), so somewhat a little less chance that is closer to a point it could seize or jam due to mechanical resistance...

Steve K

[Tin Can]

That all may be true. Sounds logical.

I keep some shutters open on T especially if I am cranking a spanner on the glass. I learned, if the shutter is closed, one slip makes for a bad day.

Packards I always store open. The Sinar is also open now. Both types often are not protected by glass.

I suppose FP shutters should be untensioned, but some may be better off cocked.

[Bob Salomon]

As many of you probably know, from 1986 till early 2015 we were the Rodenstock lens distributor in the USA. The recurring question on how to store the shutter prompted me to check stock and see how a Rodenstock set the shutters on the new lenses that they shipped to us to sell to camera stores across the country.

This is what I found and have posted several times over the years.

“We are the Rodenstock distributor. The factory sends the lenses to us uncocked, press focus closed, aperture at the largest opening and the shutter speed at the fastest shutter speed. If you buy a new lens that is also how it is sent by us to your dealer and how the dealer delivers it to you (unless it has been opened somewhere along the way).

We are also the Linhof and Wista distributor for the USA. Every Linhof and Wista, in factory packaging, Technika, M679, Techno, Kardan, TechniKardan, every Wista field, metal and 810 are packaged with the bellows fully compressed. That is also how we ship them to your dealer and how your dealer delivers it to you, in factory packaging). The cameras would not fit into their packaging any other way.”

[Tin Can]

Very interesting!

[LabRat]

I agree Bob, but not sure about storing/shipping at it's highest speed... Top speeds on leaf shutters (like 1/400 or 1/500 sec) usually have an additional spring so when the shutter is released, it adds some force/tension to push the cycle faster, so more tension is there... Bottom speeds allow the escarpments to extend fully, so when the shutter is cocked, it will allow the gears to spin a little (you can hear them buzz when you cock the shutter), but gets a little whirl/workout, as well as other linkages, etc...

Happy New Year, and all good things to you and yours!!!

Steve K

[Bob Salomon]

I agree Bob, but not sure about storing/shipping at it's highest speed... Top speeds on leaf shutters (like 1/400 or 1/500 sec) usually have an additional spring so when the shutter is released, it adds some force/tension to push the cycle faster, so more tension is there... Bottom speeds allow the escarpments to extend fully, so when the shutter is cocked, it will allow the gears to spin a little (you can hear them buzz when you cock the shutter), but gets a little whirl/workout, as well as other linkages, etc...

Happy New Year, and all good things to you and yours!!!

Steve K

Except I went into the warehouse and opened lenses in 0, 1 and 3 size shutters from our stock and that was how they were shipped from the factory. These were lenses that had been ordered for our stock, so neither the Rodenstock factory, or us knew how long they would sit on our shelf prior to our shipping them to a dealer. Nor did we know exactly how long they would sit on our dealer’s shelf. Nor did we know how long that they sat in Rodenstock’s inventory prior to shipping them to us.
So we presume that the way that they were in our inventory was the way that the factory felt was the best for storing 5he shutters.

And a very happy and healthy and hopefully warm New Year to you as well!

[Rapidrob]

Getting back to my subject, I disassembled and cleaned four shutters. I used brake cleaner and industrial Q-Tips and lens paper followed by oil free compressed air out of a Air Brush at 15 PSI.
I have no way of timing the shutters but none of them would work on any slow shutter speed at their settings. Now they are working well again. One shutter was full of grease,so much so it had oozed out and under the ID plate/speed dial. The other shutters had collected dust over the decades.
All had signs of where they had been oiled ( turned dark yellow) at the factory. I re-oiled these bearings with clock oil ( synthetic whale oil) using a pin point droplet.
The shutters are now very smooth and look and sound to be close to the proper indicated times.
Only one shutter was missing a small screw that holds the aperture detente plate on the side of the shutter housing. I will have to try and find what thread size it is and who may have one? The missing screw will not hinder using the shutter/lens.
The cleaning is not hard to do but does take a couple hours per shutter to do properly. The first shutter was a real nail biter as I had no instructions and photographed every step I took. The last of the four went much quicker.
I took two days to do the four shutters. I had to make sure all of the solvent had evaporated even after air drying the shutter.
I made a lens board out of aluminum 40 years ago that was never used. I milled it today to fit my view camera and use a 6" lens I have never used but have had for almost as long as the lens board.
Thank you for the reply's on cleaning the shutters.

[LabRat]

OK Kool!!! :-)

But the "acid test" after lube will be how these shutters will withstand cold, as the new lube + traces of the old lubes (not completely cleared out) will behave after you put the shutters in the ice box or left in the cold garage or outside overnight... And if there's an excess of lubes when hot, they can migrate...

Just lubing might get/keep things going, but it can cause other things to start happening, like your B & T settings start getting weird, because even if you apply the smallest drop of liquid oil, say between the flat arms that operate them, it can create a "suction" resistance where the pieces stick to each other due to a liquid bond, so you might have to go back in and chemically clean surfaces to polished bare metal later... (Traces of oil here or there will hang things up, sometimes after a couple of weeks in room temp conditions...)

You will get the hang of it, so keep trying and good luck!!!

Steve K

[Jim Graves]

Except I went into the warehouse and opened lenses in 0, 1 and 3 size shutters from our stock and that was how they were shipped from the factory. These were lenses that had been ordered for our stock, so neither the Rodenstock factory, or us knew how long they would sit on our shelf prior to our shipping them to a dealer. Nor did we know exactly how long they would sit on our dear’s shelf. Nor did we know how long that they sat in Rodenstock’s inventory prior to shipping them to us.
So we presume that the way that they were in our inventory was the way that the factory felt was the best for storing 5he shutters.

And a very happy and healthy and hopefully warm New Year to you as well!

I don't see the relevance ... now if Rodenstock thought that their shutters would sit on the shelves for 80 years ... maybe ... and, if you add the variable that you are talking about shutters made after 1970 (not 1930) ... maybe.

Perhaps they felt that full compression of the spring for a year or two would better ensure the slow speeds were accurate at time of sale.

Did you ever ask the experts at the factory why they were shipped compressed?

There is absolutely such a thing as metal fatigue. Any metal stressed over a long period of time will suffer from it ... springs don't magically escape. A design for a clock is essentially a low stress use of spring tension. As Mark Sawyer pointed out in an earlier post, the tension necessary and the rapid-fire full release of all tension required to fire a high speed shutter makes the comparison of the two mechanisms inappropriate.

I'll stick with Mark and Carol Flutot's recommendation and store all my shutters on either T or B.

[Bob Salomon]

I don't see the relevance ... now if Rodenstock thought that their shutters would sit on the shelves for 80 years ... maybe ... and, if you add the variable that you are talking about shutters made after 1970 (not 1930) ... maybe.

Perhaps they felt that full compression of the spring for a year or two would better ensure the slow speeds were accurate at time of sale.

Did you ever ask the experts at the factory why they were shipped compressed?

There is absolutely such a thing as metal fatigue. Any metal stressed over a long period of time will suffer from it ... springs don't magically escape. A design for a clock is essentially a low stress use of spring tension. As Mark Sawyer pointed out in an earlier post, the tension necessary and the rapid-fire full release of all tension required to fire a high speed shutter makes the comparison of the two mechanisms inappropriate.

I'll stick with Mark and Carol Flutot's recommendation and store all my shutters on either T or B.

To each their own.