Problem with my 'new' Compound shutter: my own fault!

[Paul Kinzer]

I just received a 300mm Schneider convertible Symmar* in the older Compound shutter that I know they came in. The seller had said the shutter would fire inconsistently, but I recalled reading that you need to wait a bit after cocking these pneumatic shutters before firing them. Sure enough, if I waited several seconds before tripping after cocking, it fired at increasingly longer speeds as I went down the scale. Yay!

But not so much now. The speeds seemed a bit fast, and I also remembered reading that putting a bit of dry lubricant into the piston could make the shutter able to fire more quickly, and that it can help with speed accuracy, too. but, as I should know by now, not everything one reads is true. Now, the shutter fires way too quickly. as in, 1 second seems to fire at 1/50th. I assume I broke some kind of seal, and that the piston is no longer doing its job.

I have not yet searched the internet for a solution (I'm afraid). and hope for help here.

But, hey, I'm not very patient, so I'll go looking as soon as I post this. If I find and easy, non-shutter-wrecking solution, I'll come back and post it.

*This was one of those eBay deals I look forward to. In addition to a shutter that worked (notice the past tense!), contrary to how it was advertized, the ad also said there was haze in the front element. This was one of those lucky times when I unscrewed it, and the 'haze' just wiped right off, revealing almost perfect glass! This is my third Schneider lens where this has been true. This one makes up for the 135mm Fuji W lens that was sold with the same warning. That haze was internal, and would not wipe off. But it's so minor you really have to look through it at the right angle under the right light to even detect it) that I'm going to live with it till I see what effect it might have, if any.

Paul

[AJ Edmondson]

It sounds as if the piston is sticking as opposed to moving over the range determined by the setting. You might try removing the end caps located at the ends of the cylinder and check for cleanliness (lack of any type residue). These are really good shutters (within their limitations) and Carol Flutot or SK Grimes are excellent at repairing them.

[Paul Kinzer]

^^

Actually, that's exactly what I did, and it was then that the problem started. I'll post a photo of the piston end caps in a bit. They have some copper-colored circles inside them, and I'm wondering if these are seals that came off when I removed the caps. And now I wonder if, when I screw them back on, the seals no longer seal.

Should I put something in there to re-seal them, and if so, what?

[Paul Kinzer]

I found this page (http://www.largeformatphotography.info/forum/showthread.php?21578-Compound-shutter-problem) here on the forum. Someone was having a problem very similar to mine, and the last commenter wrote:

'The end caps have little gaskets that may have dried out. If the caps don't hold an air tight seal the shutter can act like that. Try removing the caps, add a drop of oil to each, let it sit for a minute to swell the gasket and reinstall them. It might solve your problem.'

I tried it: nope! And I waited a lot longer than a minute. I still think non-working seals might be my problem, since it worked okay until I removed the end caps.

I also tried 'exercising' the piston by gently pushing it back and forth with the end of a paper clip. I was careful not to force it in any way. I put a bit of dry graphite lubricant into the bit of the piston shaft where it did not go completely freely when cocking the shutter. I don't know if it is even supposed to go there, but found that, when I pushed it there with the caps removed, with the shutter set at 1 second, and then tripped the shutter, the shutter did something different: instead of just firing at a high speed, it opened and got stuck. A touch to the cocking lever made it close.

This is what made me wonder if you had it right, AJ Edmondson, and it needed some help. It looked clean, and moved fairly freely, but this is when I figured it could not hurt to put a bit of graphite into the piston cylinder. That fixed the getting stuck problem. It doesn't do that anymore, but it doesn't work, either. It still fires at a single, high speed, no matter the setting.

[Paul Kinzer]

Okay, it's me again, making comments on my own query. I just tried something else: With the end caps off, I cocked the shutter, which moved the retarder in the piston cylinder into position. I then put a fingertip tightly against each end of the cylinder, forming my own seal. Then I tripped the shutter. It opened, and stayed open until I released one of my fingers. Then I figured out that, if I did not squeeze too hard, so that the flesh of my fingers intruded into the shaft of the cylinder, the shutter opens and then closes! The volume of the air in the cylinder obviously has to be just so in order for all to work as it should.

So it seems that the seals are the issue. The problem now is, how to fix them.

[Jac@stafford.net]

I put a bit of dry graphite lubricant into the bit of the piston

Please never use dry graphite in any part of a lens. It has the tendency to migrate and really muck-up the optics,
.

[Paul Kinzer]

Please never use dry graphite in any part of a lens. It has the tendency to migrate and really muck-up the optics,
.

I'd be interested to hear more about this, as I've done it with shutters that I could not get to work in any other way, and my own experience has been that, if only a tiny bit is used, and the excess blown out with a can of air after a bit of exercise, the only issue is some specks of graphite dust on the inside of the glass. It's easily wiped off, and graphite is very soft (that's why pencils work), so it doesn't harm the glass, which is very hard. And I've found that these specks only appear for a while after doing this. I have lenses that I did it with years ago, and have not seen any specks for a very long time. And the shutters still work.

While I understand that it may not be the done thing by professionals, I'm on a very limited budget. If I can buy a shutter that doesn't work for a very low price, and get it to work for almost nothing, that's the choice I'm going to make, because I cannot afford a different one.

I apologize if this seems snarky, or even negative. It's not meant to! I'm just making my case.

By the way, here's a photo of the end caps:

167153

Does anyone know if those copper-colored bits are the seals, and what might be done with them?

[Chris7521]

I'd be interested to hear more about this, as I've done it with shutters that I could not get to work in any other way, and my own experience has been that, if only a tiny bit is used, and the excess blown out with a can of air after a bit of exercise, the only issue is some specks of graphite dust on the inside of the glass. It's easily wiped off, and graphite is very soft (that's why pencils work), so it doesn't harm the glass, which is very hard. And I've found that these specks only appear for a while after doing this. I have lenses that I did it with years ago, and have not seen any specks for a very long time. And the shutters still work.

While I understand that it may not be the done thing by professionals, I'm on a very limited budget. If I can buy a shutter that doesn't work for a very low price, and get it to work for almost nothing, that's the choice I'm going to make, because I cannot afford a different one.

I apologize if this seems snarky, or even negative. It's not meant to! I'm just making my case.

By the way, here's a photo of the end caps:

167153

Does anyone know if those copper-colored bits are the seals, and what might be done with them?
They are seals. If they are bad or the caps are not tight, the piston will not slow the speeds down because the air leaks out. I have made seals for a shutter using a very thin gasket making paper found at automotive stores if you need replacements.

[domaz]

Slightly related question- does anyone know of an off the shelf replacement for Compound shutter end-caps, or at least the threading they use? I took one to the hardware store and couldn't find a match with modern common threads, using their thread finder board.

[John Kasaian]

I've always heard that nose oil was the ticket for lubricating Compound shutter pistons?

[John Kasaian]

Slightly related question- does anyone know of an off the shelf replacement for Compound shutter end-caps, or at least the threading they use? I took one to the hardware store and couldn't find a match with modern common threads, using their thread finder board.
I'd ask Carol at Flutot's what she'd recommend.
http://www.flutotscamerarepair.com/

[Paul Kinzer]

I'd ask Carol at Flutot's what she'd recommend.
http://www.flutotscamerarepair.com/

I did just that, and I'll post here about it once I get some results!

[Phil_F_NM]

Have you tried sealing the cylinder with some Teflon tape?

Phil Forrest

[Paul Kinzer]

I'm only coming back now to this thread because I only got time today to finally finish with the lens.

I got the piston working well -- or, well enough -- by trial and error after several hours of experimentation. I wrote to Carol, and she was really helpful. The first thing I found out was that the copper-colored circles in the photo up-thread were the old seals. They had dried up, and Carol told me to pry them out and replace them with thin cardboard of some kind, and to put a drop of oil on the cardboard before sealing up the ends with the caps again.

This worked, but the speeds were too fast. Carol said that putting in slightly thicker cardboard would slow the speeds down. I tried this, but then found that the caps would not go on all the way, and seemed to leak air, so the shutter stopped working again. In the end, I found that two things worked to fix it: first, rather than putting a thick piece of cardboard in, I put two thin ones in; a larger one that fit under the piston threads and gave a tight seal while letting the cap screw on all the way, and another, smaller circle under that one, which causes a bulge into the piston, and slows the shutter down. Second, I put Teflon tape on the threads. It was the only way I found that seemed to seal them up.

The 1 second setting seems very close now, though, as these shutters do, it needs to be left for about ten seconds after cocking before you can trip it. And the other settings are off (hance my 'well enough' comment). To get a 1/2 second firing, I need to set the dial about 1/3 of the way toward the 1 setting from the 2 setting. The two setting seems to be about 4, and so on. The main thing is that the speeds seem to be consistent, if I leave the shutter for at least 8 to 10 seconds after cocking. I'll use my shutter speed tester to find just where to set the dial for proper speeds.

Unfortunately, once I got all this working, the B and T settings stopped working! I wrote to Carol again, and was sent a photo of the guts of the shutter, with the advice to either tighten a couple of specific screws, and/or to give the B and T levers a cleaning. The screws were already tight. The B lever rides above the T lever, so I just took it out (not too difficult) and cleaned it outside the shutter. While it was out, I very carefully cleaned the T lever inside the shutter with a bit of 'Goo-gone' (I think lots of different things would have worked -- naphtha, mineral spirits, etc -- because what came off was old, dried-up oil). I know the aperture blades in these shutters are very delicate (paper?!), and didn't want to get any liquid on them. So I put a drop of Goo-gone on a Q-tip and rubbed it on the T lever. The top cleaned up instantly, and as I moved the lever back and forth on its axis of movement, a tiny bit of Goo-gone must have gone under the lever, because oil residue would be left on the 'floor' of the shutter. I wiped it off with the clean end of the Q-tip, and kept it up for another two q-tips, till the residue stopped appearing. This fixed the problem.

While doing all of this, the solder holding the wire for the flash synch broke! I'm not sure I'll ever use a flash with this lens, but since I had it apart, I re-soldered it.

Sheesh! It's all back together now, and I hope it stays that way. It feels good to have fixed it myself, and to have learned something, but enough is enough.

Well, almost. I decided, after all that, to disassemble the rear cell, to see if I could get off a bit of remaining haze, as well as some bits of paint that had flaked off the metal housing and drifted in between the elements. It's much better now, and this sixty-year-old lens is in much better shape. I got it for $99 on eBay, and I'm happy.

I've had a very long day (the shutter work was done after an already long day), so I'll post a photo showing the levers inside the shutter tomorrow.

[Paul Kinzer]

Okay, here's the photo of the inside of the Compound shutter. I've marked where the trip lever sits, and this was just lifted off. A screw had to be removed to get the 'B' lever off. Maybe I should have removed the 'T' lever, too, because today, it closes sluggishly. I must not have gotten all the old lubricant out from underneath it. But the shutter is opened in both settings with the 'B' lever, and that moves very smoothly, since I was able to clean both sides of it, as well as the top of the 'T' lever, which is what the 'B' lever rides against. At the 'B' setting, the shutter works perfectly.

I guess I'll only use the 'T' setting for composing images on the ground glass, and the 'B' setting for actually taking long exposures, so having the shutter close sluggishly at the 'T' setting is fine. Getting the 'T' lever removed would have been more work than I wanted to do. Maybe I'll come back to this one day....

167462

By the way, this image was taken before I cleaned the shutter up. Quite a bit of grunge.

[Pere Casals]

Okay, here's the photo of the inside of the Compound shutter. I've marked where the trip lever sits, and this was just lifted off. A screw had to be removed to get the 'B' lever off. Maybe I should have removed the 'T' lever, too, because today, it closes sluggishly. I must not have gotten all the old lubricant out from underneath it. But the shutter is opened in both settings with the 'B' lever, and that moves very smoothly, since I was able to clean both sides of it, as well as the top of the 'T' lever, which is what the 'B' lever rides against. At the 'B' setting, the shutter works perfectly.

I guess I'll only use the 'T' setting for composing images on the ground glass, and the 'B' setting for actually taking long exposures, so having the shutter close sluggishly at the 'T' setting is fine. Getting the 'T' lever removed would have been more work than I wanted to do. Maybe I'll come back to this one day....

167462

By the way, this image was taken before I cleaned the shutter up. Quite a bit of grunge.

Thanks for posting all that information, I'll keep it for the case one day my beloved #4 needs a repair procedure !

[Paul Kinzer]

I'm glad when something I've written is helpful, Pere! I post here and at a couple of astronomy forums when I think I have either a question or some knowledge that others might find useful.

Carol at Flutot's is where I got all my instructions: very helpful and friendly!

[jim10219]

On these shutters you can remove the inside components fairly easily in one big chunk from the rear housing. There are some screws on the back that allow you to do that. That way you can separate the paper iris blades from everything else (they have a retainer ring to hold them in place so you don't have to worry about reassembling them), to give the shutter's mechanicals a good cleaning and inspection. This also allows you to get a better look at the bottom where the shutter blades are and inspect them for dirt and dried up oil. Just make sure if you remove them, to keep them in order.

With the piston's end caps, there's a delicate balance between leaking some air, but not too much. If it leaks too much air, all speeds will be 1/75. If you don't let any air leak, it won't shut at all. I've used manila envelopes and a touch of lithium grease to replicate these seals. The envelopes are thin enough that you can adjust the thickness by adding layers.

What I love about these shutters is they're fairly easy to take apart and work on. Just document every step with a DSLR, and be careful to keep all of the screws and parts organized and separated so you can get it put back together in the same order and orientation that you took it apart.

[MAubrey]

Okay, here's the photo of the inside of the Compound shutter. I've marked where the trip lever sits, and this was just lifted off. A screw had to be removed to get the 'B' lever off. Maybe I should have removed the 'T' lever, too, because today, it closes sluggishly. I must not have gotten all the old lubricant out from underneath it. But the shutter is opened in both settings with the 'B' lever, and that moves very smoothly, since I was able to clean both sides of it, as well as the top of the 'T' lever, which is what the 'B' lever rides against. At the 'B' setting, the shutter works perfectly.

I guess I'll only use the 'T' setting for composing images on the ground glass, and the 'B' setting for actually taking long exposures, so having the shutter close sluggishly at the 'T' setting is fine. Getting the 'T' lever removed would have been more work than I wanted to do. Maybe I'll come back to this one day....

167462

By the way, this image was taken before I cleaned the shutter up. Quite a bit of grunge.
This is exactly what I need to deal with my compound shutter. I've been having the exact same issue recently.