Nikon FM2n shutter adjustment/service
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monopix
Cam repairer
Hi,
Is this with the shutter out of the camera?
Both curtains should move when you cock it. Are you saying only one moves?
Is this with the shutter out of the camera?
Both curtains should move when you cock it. Are you saying only one moves?
ol68
Newbie
The shutter is out of the camera.
Sorry, both curtains move and then jump back. When i let them back smooth, the second curtain won't close fully.
If i push the release pin there is only a click, curtains don't move.
Sorry, both curtains move and then jump back. When i let them back smooth, the second curtain won't close fully.
If i push the release pin there is only a click, curtains don't move.
monopix
Cam repairer
The second curtain not returning will be the curtain brake - it should be fine if the curtain is running at normal speed.
I don't understand "If i push the release pin there is only a click, curtains don't move." if the shutter won't remain cocked then the release won't do anything.
Check the cam rotates as you cock the shutter and watch the release lever. It should latch behind a notch (step) in the cam. Maybe the spring that pulls the release lever into it's latched position has come off or maybe the cam isn't rotating far enough or maybe there is grease there making the latch slip.
I don't understand "If i push the release pin there is only a click, curtains don't move." if the shutter won't remain cocked then the release won't do anything.
Check the cam rotates as you cock the shutter and watch the release lever. It should latch behind a notch (step) in the cam. Maybe the spring that pulls the release lever into it's latched position has come off or maybe the cam isn't rotating far enough or maybe there is grease there making the latch slip.
Carlos_EVH
Member
Hello, I have a FM2n with a problem with the first curtain release. After a complete disassembly because the old owner messed up the curtains pushing the second curtains with his finger and broke them, I cleaned all the shutter gears and mechanisms because the first curtain never release. The shutter cocks both curtains but when I release it, only the second curtain moves, the first one get stuck in the same position, and the lever that have to move to fire the curtain, only moves a bit but it doesn't get to fire the curtain so i have to release manually with the tip of the scredriver.
I can upload photos or videos if you want but i want to save this FM2 because is almost in mint conditions.
On the other hand, all the photos have been lost in imgur, can you reupload? There is not so much information about the Copal shutter for the FM2 and your post is one of the few sites where there was information.
I can upload photos or videos if you want but i want to save this FM2 because is almost in mint conditions.
On the other hand, all the photos have been lost in imgur, can you reupload? There is not so much information about the Copal shutter for the FM2 and your post is one of the few sites where there was information.
monopix
Cam repairer
Hi,
As this is the second time the images have gone missing, I've now put this information on my blog at Contax S2 shutter adjustment
The text has been updated but contains the same information.
Sorry I can't help with your specific problem.
Carlos_EVH
Member
Hello, thanks for the link, is very usefull.
After a closer inspection of my shutter, the real problem seems to be the little shaft that goes under the white cam of the escapement. When I cock the shutter, that shaft, that is connected to another little shaft in this piece, doesn't go all the way under the white cam, so when i press the shutter release, althought the cam rotates perfectly and moves the little shaft, this one doesn't have enough speed/force to move the first curtain release mechanism, so the curtain doesn't move from the cock position.
This is the position of the shaft when i cock the shutter normally, there is a gap between the shaft or post and the cam wheel
And this is the correct position where the shaft should be when a i cock the shutter. To get there, I have to push the shaft inside the cam with a pair of tweezers as I said.
So I assume the problem is under the scapement mechanism but after taking apart all the shutter, everything looks perfectly in place and in good shape. I cleaned with IPA every single piece even the main base for the shutter. All the springs has force, nothing is bent or deformed and everything moves freely and snappy but I don't know what part or piece is preventing the shaft goes under the cam.
monopix
Cam repairer
There's several linkages between that pin and the first curtain latch so any one of them could be the issue. Either there is a spring not engaged properly or one of those links is binding against something.
Are you saying you have dismantled all of the shutter timing mechanism? If so, it seems something hasn't been put back correctly.
Also, not sure if you know that pin gets pulled away from the cam slightly when the shutter is set to 1/2000 and 1/4000 so to check it's movement, use a slower speed (though it looks like you have 1 second selected so should be OK).
Separate issue. I did notice your second curtain brake is not screwed down properly. This needs tightening. You may need to put some thread lock on the screw to stop it from unscrewing itself.
Are you saying you have dismantled all of the shutter timing mechanism? If so, it seems something hasn't been put back correctly.
Also, not sure if you know that pin gets pulled away from the cam slightly when the shutter is set to 1/2000 and 1/4000 so to check it's movement, use a slower speed (though it looks like you have 1 second selected so should be OK).
Separate issue. I did notice your second curtain brake is not screwed down properly. This needs tightening. You may need to put some thread lock on the screw to stop it from unscrewing itself.
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Carlos_EVH
Member
Yes, the second brakes screw is a bit loose after a lot of attemps trying to Make the first curtain moves when the shutter is released.
I didn't touch the top mechanism, I took apart the curtain mechanism and clean everything to the bare black plate, in fact, i've took It apart several times trying to detect the problem but I can't figure out what is causing all this trouble. I'll try to take more pictures of every piece and springs and their position while disassembly to figure out what is the problem because is the only thing that is failing in this shutter.
monopix
Cam repairer
The curtains won't be causing this. No point in dismantling them again. There's no direct connection between the curtains and the pin that is failing to move up to the cam.
The pin and the linkage it connects to are driven by two springs, I think (red arrows). Looks like they are both in place in your pictures but take a look at them.
The linkage is in this area (circled green). Take a look around there. There might be a shard of film stuck in there maybe. I always use an air line to blow out any debris. There's also a contact point between another pin and a lever that looks like a tiny bit of light grease on it wouldn't hurt. I've never had to do it but these two parts rub against each other so might be sticky maybe.
The pin and the linkage it connects to are driven by two springs, I think (red arrows). Looks like they are both in place in your pictures but take a look at them.
The linkage is in this area (circled green). Take a look around there. There might be a shard of film stuck in there maybe. I always use an air line to blow out any debris. There's also a contact point between another pin and a lever that looks like a tiny bit of light grease on it wouldn't hurt. I've never had to do it but these two parts rub against each other so might be sticky maybe.
Carlos_EVH
Member
I've uploaded several videos to YouTube. The part you marked in my unit barely pushed the pin so i think that is the problem but the pieces that should push the pin looks good and the springs that push back that piece looks fine too.
I did a YouTube Playlist with all the videos that I took of the problem and different parts, if you can take a look, I can't tell if something is really wrong or most of the problem is just the wear of the pieces and springs after so many years. Thanks for everything
WoodallP
Pragmatist Barnack lover
Wow, I am sticking with Barnacks! I felt good about my successes till I saw this stuff!
Carlos_EVH
Member
I have no fear, i only have a screwdriver and, a pair of tweezers and two big balls to disassembly this stuff lol
Just kidding, i only want to fix the camera, It deserves a better final, I have 2 FE-2 and one FA, all of them in perfect condition, the FM-2 can't die before the others 🤣
monopix
Cam repairer
I've skimmed the videos. Need to watch them again. Tomorrow.
Carlos_EVH
Member
I think I found the solution, I think is the little spring at the left of the red Arrow you draw in the first imagen of the last post. I've attached the springs in another place and It doesn't make tension. This is a Picture i took this afternoon while recording the video, you can see the tip of the left spring not attached to the inverted S piece.
Tomorrow I'll take apart again the shutter and try to put the spring in the correct position.
monopix
Cam repairer
Could be. I'm going to watch your videos again anyway. I've not had to dismantle one to that extent so interesting to see the shutter apart like that.
Do you have the facility to check curtain speeds? Or how will you retention the curtain springs correctly?
Do you have the facility to check curtain speeds? Or how will you retention the curtain springs correctly?
Carlos_EVH
Member
At the moment I only can compare the shutter speed against my 2 Nikons FE-2 in working condition and a FA. It's 0 reliable method to measure speed but I can figure out with my eye if any speed is much more slower than in my FE-2 or even if some speed is messed up and i can't see the light between the curtains when release the shutter.
In the other hand, I have a few arduinos without any use right now, so i can use one of them to build a cheap shutter speed tester with a few cables, resistors and a phototransistor. I've seen a few projects for arduino that works with some sort of accuracy at 1/2000s so if the shutter is more or less accurate at that speed I'll assume that it will work as well at 1/4000s and then I'll assembly all the camera again.
monopix
Cam repairer
I was thinking more of the curtain speeds than the shutter speeds. You need to get the curtains both running at the same speed to prevent tapering. You also need the curtain speed to be close to the specification otherwise it may not sync properly with a flash.
Carlos_EVH
Member
I can use a piece of tape to mark the point where both curtains rest when the shutter is loaded as distance = 0, and mark it every millimeter until I reach the point where the curtains rest when I release the shutter. And use my phone's slow-motion recording mode to see if both curtains reach a specific distance at the same time. I can't think of any other way to verify this 🤔
monopix
Cam repairer
Could work if your phone can can capture about 100 frames per second. Curtain travel time is just 24ms. This might be useful:
