Kodak Signet 35 / Synchro 300 Shutter Hangs

Hey everyone. I have this Kodak Signet 35 that I bought a few months ago, and just when passing through what must be the sixth or seventh roll of film by now, I noticed that the shutter was sticking at all speeds. And I really mean sticking - it hangs open indefinitely until I give the cocking lever a little push upwards.

I realize this is a bit of a notorious issue with the Signets, though from everything I read it's mostly due to dirt buildup in and around the star wheels and pallets. So with that in mind, I went ahead and opened her up. To my surprise, everything is more or less clean in there. I did use some q-tips, toothpicks, and ethanol to spot clean a few areas where I saw some black grime buildup, but that didn't seem to do anything to fix the problem.

I went over every little spring I could see, and as far as I can tell at least, the tension everywhere is more or less fine. I played around with the trigger and cocking mechanism and there doesn't seem to be any slack or friction where there shouldn't be; they snap back perfectly if I tense them just a little. But cocking all the way and then firing will make it hang, and I don't understand why.

To the naked eye, there's no rust or corrosion either. And just to make sure, I cross-referenced with some scans I found of the original repair manual for this model of shutter, and there aren't any missing parts or anything like that.

The last thing that came to my mind was to re-tighten all the screws visible from the top, and when I did that, lo and behold the shutter sprang back to life, with all the speeds seeming consistent. However, after cycling through about 20-30 shots to test it out, it started hanging again. Now I really don't know what to do, and none of the online resources on this particular model that I've managed to find are really helping me that much. Anyone know anything that might be causing this?

Just as a shot in the dark, did you lubricate the camera after you cleaned it?

For rotating parts watch or maybe oil for an electric shaver. You can use the eye of a sewing needle
to apply it to each shaft.
Oil used for camera repair are clear and have similar viscosity of water.

For sliding parts, a light wipe of light grease is used. By light I mean if you can see it after you've
applied it, that's too much,

If the lube doesn't work it may take a swipe with a needle file on the release lever.

There are a couple of members here that may be able to help out They are Mamiya repair and shutterfinger

Hope it's nothing major.

Agreed: some of those shutter components won't work well if left bone dry. A very light application of Molybdenum (I use a smear on a paintbrush, just enough to leave a grey stain) will make this shutter run better, I suspect.

The first thing to clean in a Signet is the timing escapement, both starwheel and pallet. Lift them out and clean in naphtha or with spray-on CRC electronics cleaner. Then stain the starwheel's teeth with Moly as paulbarden suggested. The main drive ring and lever probably could use a hint of grease as John Koehrer suggested. I use Superlube. Then have fun shooting with it!

Mark Overton

Thank you guys for your advice! I went ahead and very conservatively lubed the shutter with some gun oil, and now it does seem a lot more snappy when firing - but it still sticks open. I can just about make out a tiny black spot of what I assume to be very old oil or grease on one of the diaphragm blades, so I suppose this calls for a full disassembly and wiping the shutter blades clean of whatever gunk has accumulated in there and is making them stick. Oh boy...

John Koehrer said:

Just as a shot in the dark, did you lubricate the camera after you cleaned it?

For rotating parts watch or maybe oil for an electric shaver. You can use the eye of a sewing needle
to apply it to each shaft.
Oil used for camera repair are clear and have similar viscosity of water.

For sliding parts, a light wipe of light grease is used. By light I mean if you can see it after you've
applied it, that's too much,

If the lube doesn't work it may take a swipe with a needle file on the release lever.

There are a couple of members here that may be able to help out They are Mamiya repair and shutterfinger

Hope it's nothing major.

Click to expand...

This is not good advice, sorry. Because we're talking about a shutter and shutters can also be temporarily ruined if oil gets in the wrong place.

RJ Jacoby said:

Thank you guys for your advice! I went ahead and very conservatively lubed the shutter with some gun oil, and now it does seem a lot more snappy when firing - but it still sticks open. I can just about make out a tiny black spot of what I assume to be very old oil or grease on one of the diaphragm blades, so I suppose this calls for a full disassembly and wiping the shutter blades clean of whatever gunk has accumulated in there and is making them stick. Oh boy...

Click to expand...

Yes, the shutter needs to be fully stripped down, down to the shutter blades, then completely removed of the oil.

Then oil applied specifically where it needs it, with proper oil like Moebius 9030. Many parts in a leaf shutter should NOT be lubed, it depends on the shutter.

Every leaf shutter was designed around appropriate (tiny) quantities of appropriate (very low viscosity pure mineral) oil, because molybdenum disulfide didn't exist as a commercial product when they were designed and graphite has other problems (like not staying where you put it -- moly disulfide has the same problem). Not to say MoS2 isn't a good substitute, just that they were designed to be oiled (correctly, much like lubricating a pocket watch).

That said, nearly all leaf shutters will work dry, they just won't last a century, through potentially hundreds of thousands of cycles, running that way.

Okay guys...I'm at a loss. I took apart the whole shutter piece by piece according to the repair manual, degreased and cleaned every tiny nook and cranny with IPA, then wiped and wiped and wiped the shutter blades for hours until there was not a single speck left anywhere - and now that I put the whole thing back together again, it works worse than before. The shutter doesn't even open all the way by itself when it's fired, I have to give the cocking lever a little push with my finger. And then it's even more sluggish while closing.

I have no clue at this point. I made sure to lube exactly the posts and parts that the repair manual suggested to, and nothing else. Everything on the inside looks absolutely pristine, near-mint. What could even be acting up here?

Did you put the blades back in correctly?

I don't know this shutter exactly, but is it possible to remove all the escapement parts and make certain that the blades move freely? Keep adding parts until the binding returns.

Also sometimes on these Kodak shutters you can find binding parts by loosening screws ever so slightly. Don't leave it like this- go in and clean up the part, hone it down with a stone, or such.

And run a toothpick into the various escapement gear holes and spin it around to clear out any corrosion

With the cocking lever partly cocked, operate the blade pin with a toothpick. The blades should open and close effortlessly. Assuming they do...
I have found that the master ring in the shutter can have friction at its hold-down points, and at any other point in its cycle. Slowly release it by gradually moving the cocking lever through the release-cycle, and note where spring force against your finger becomes light or gone. Then find out what's impeding the ring at the point.
Good luck,

Mark Overton

Dan Daniel said:

Did you put the blades back in correctly?

I don't know this shutter exactly, but is it possible to remove all the escapement parts and make certain that the blades move freely? Keep adding parts until the binding returns.

Also sometimes on these Kodak shutters you can find binding parts by loosening screws ever so slightly. Don't leave it like this- go in and clean up the part, hone it down with a stone, or such.

And run a toothpick into the various escapement gear holes and spin it around to clear out any corrosion

Click to expand...

I disassembled the shutter again, took note and numbered each tiny change, and by now I am only more puzzled -- taken apart down to the shutter blades, the mechanism works smoothly, so the blades are fine. But with each part I added from there, whether the shutter fired or not seemed to change mostly randomly.

Add a spring here, it trips okay about ten times - then freezes. Remove the same spring, it still sticks. Even weirder: before I even took the camera apart today, I test-fired it a few times. Again, it routinely springs back to life, works for about 10-20 shots, and then locks up, with seemingly no change in behavior no matter which parts I take out, replace, or mess with.
I played with the screws too, but it doesn't seem to be making any difference. There are only two major gears in this mechanism and I cleaned both of them very thoroughly, so I am certain that they're not the issue. Besides, the shutter doesn't seem to care whether I leave them in or take them out, either. Sometimes it works, sometimes it just won't. I'm struggling to find a pattern here.

albada said:

With the cocking lever partly cocked, operate the blade pin with a toothpick. The blades should open and close effortlessly. Assuming they do...
I have found that the master ring in the shutter can have friction at its hold-down points, and at any other point in its cycle. Slowly release it by gradually moving the cocking lever through the release-cycle, and note where spring force against your finger becomes light or gone. Then find out what's impeding the ring at the point.
Good luck,

Mark Overton

Click to expand...

Thanks for the suggestion! I tried that, and while I feel like there might be something to this, I couldn't make out any slack or tension by feel. There is of course an increase in tension as the cocking lever is armed (as there should be), but in reverse it feels perfectly smooth. It's just when I actually trigger the release that it sticks. Furthermore, even after prodding around in there for a solid half-hour

I couldn't for the life of me make out why it freezes always at the exact same point when the shutter is tripped - about 2/3 of the way to its resting position. There is literally nothing there that could physically block it, and like I said earlier: giving it even the slightest push with my fingertip allows it to release just fine.

I bet that there is some corrosion on a part. Just enough of a grit spot to hang it up. I can't say where to look, but study where the shutter stops and look at every point where two parts are touching. Look at where the rotating parts may have lower or upper surfaces that rub against something like the main body plate. Take a magnifier glass to these surfaces. If you find something, put some polishing compound on a toothpick and try to remove it.

A bit of a cheat of a way out might be to shorten the main spring or another spring. If the spring is a long coil, you can cut off a couple of coils, rebend an attachment loop (very gently) and reinstall. The spring could have lost just a bit of 'oomph.'

Dan Daniel said:

A bit of a cheat of a way out might be to shorten the main spring or another spring. If the spring is a long coil, you can cut off a couple of coils, rebend an attachment loop (very gently) and reinstall. The spring could have lost just a bit of 'oomph.'

Click to expand...

This is an ultimate LAST resort -- I wouldn't even try it unless you have a replacement spring in case it makes things worse instead of better. Most of the springs in shutters I've worked on are hairpin type, and you can't even do this.

Yeah, I know, Donald, asking for trouble. FYI, the main spring on the Synchro 300 shutter is an extension coil as with most Kodak shutters, scroll down to step 2-


And if you go to step 4, sure looks like that spring was bent in removal.