jerzy Posted April 11 Share #41  Posted April 11 (edited) Advertisement (gone after registration) remote diagnosis is not easy but you have posted great videos. Could it be that when you press release fast/sharply shutter works OK but when you are pressing slowly it is not? one of your videos let me think that the problem is not with tension but with the point when shutter is released. I will try to explain it on base of these 3 photos, they are showing IIIf but IIIg has it the same. Right photo shows brake disc, shutter is released, Disc is connected to opening shutter, when you span the shutter disc rotates CCW, indent is then where now X shows and the anchor hooks in the indent. When you are pressing release the flat springt at the bottom is pushing away the anchor away and releasing the shutter. This is 1st place where shutter is hold when spanned. Left photo shows film transport sprocket drum, it has two pins at the bottom (one is approx where the arrow points to, the other 180 degree opposite). Inside tzhe sprocket drum runs shutter release shaft. When you press release shaft is pushing silver gear down and it unhooks from the pins on sprocket drum, sshutter starts to run, silver gear rotates. These pins are the the 2nd place where shutter is behing hold. When releasing the shutter firstly the pins on the sprocket drum shall be released and only a bit later (release pressed a small bit more down) the anchor. In order to get it right the flat spring must be repositioned properly. It is a bit tricky adjustement. Losen both screws marked blue and reposition the sprong to get it correctly. On the video it looks to me like the anchor is released firstly and the pins only after. Most probably you will need to move the spring up a bit. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Edited April 11 by jerzy Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/399193-iiig-slow-speeds/?do=findComment&comment=5785112'>More sharing options...
Advertisement Posted April 11 Posted April 11 Hi jerzy, Take a look here IIIg slow speeds. I'm sure you'll find what you were looking for!
qqphot Posted April 12 Author Share #42  Posted April 12 11 hours ago, jerzy said: remote diagnosis is not easy but you have posted great videos. Could it be that when you press release fast/sharply shutter works OK but when you are pressing slowly it is not? one of your videos let me think that the problem is not with tension but with the point when shutter is released. I will try to explain it on base of these 3 photos, they are showing IIIf but IIIg has it the same. Right photo shows brake disc, shutter is released, Disc is connected to opening shutter, when you span the shutter disc rotates CCW, indent is then where now X shows and the anchor hooks in the indent. When you are pressing release the flat springt at the bottom is pushing away the anchor away and releasing the shutter. This is 1st place where shutter is hold when spanned. Left photo shows film transport sprocket drum, it has two pins at the bottom (one is approx where the arrow points to, the other 180 degree opposite). Inside tzhe sprocket drum runs shutter release shaft. When you press release shaft is pushing silver gear down and it unhooks from the pins on sprocket drum, sshutter starts to run, silver gear rotates. These pins are the the 2nd place where shutter is behing hold. When releasing the shutter firstly the pins on the sprocket drum shall be released and only a bit later (release pressed a small bit more down) the anchor. In order to get it right the flat spring must be repositioned properly. It is a bit tricky adjustement. Losen both screws marked blue and reposition the sprong to get it correctly. On the video it looks to me like the anchor is released firstly and the pins only after. Most probably you will need to move the spring up a bit. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members!  Thanks for this great explanation. I can follow it all. I've made some more photos just to confirm. Please feel free to take them all and use them for whatever you like, if they're useful. I've fiddled with the flat spring a bit and I can see how it influences when the sprocket drum pins and the brake disc anchor release. I can now push the release button very slowly and see that first the pins on the sprocket drum and silver gear disengage from each other, while the anchor in the brake disc detent still holds a very tiny bit longer. This is with the flat spring close to or at the limit of its adjustment. Pins against each other:  The anchor is still just barely holding here, you can see if you zoom in a bit.  I can push enough to disengage the pins before the anchor releases, but juuuust barely. Here i've turned the sprocket drum a little with my finger to show clearly that they're disengaged, and the first curtain hasn't released yet.  This may have eliminated the delay in opening the first curtain, at least I tried once after it sat 15 minutes and it didn't lag, but I'll know better after a couple of hours I guess.  However, once the first curtain opens, there's *still* a delay starting the second curtain. So perhaps two separate problems! Link to post Share on other sites More sharing options...
jerzy Posted April 12 Share #43  Posted April 12 it could ver well be that there are 2 separate problems. But let us touch firstly releasingf the opening curtain. Photo below shows adjustment from IIIg repair manual, adjustment is being made by repositioning the flat spring. Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! But sometimes it is necessary to bend a bit anchor arm to achieve proper sequence (pins first, anchor second).So you might need to repeat this adjustemnt few time to get it right. And a short exdlanation to the role of anchor. It was introduced in IIIc, IIIb and below had only one place where shutter was hold after spanning and these were pins on sprocket drum. IIIb and below did not had ratchet on winding spindle, rather than, in order to prevent the whole transport to rotate back when spanned there was a special spring in wind spindle. Adjustment of this spring was very critical and time consumking - it shall prevent shutter and film to rotate back (under the tension of shutter springs) but in the same time, after spanning it shall go back just a tiny bit to reduce the tension on the pins. Sometimes you may oberseve following effect on IIIb and below - after spanning pressing the shutter goes hard. But if you rotate wind knob just a tiny bit back it goes then fine. In order to reduce this complucated adjustment and make releasing softier the anchor has been introduced together with the ratchet (well, the very first IIIc and IIId had anchor but still the same special spring as IIIb and below, but we shall forget oit here). In IIIc and above, when you are spanning there is a tension on the pins but then, when fully spanned ratchet allows a tiny movement back and the tension from pins is away, shutter is hold by the anchor only.-If the anchor is releasing too early then curtain move just a bit, so that the pins are catching. And this is not correct, pins shall have a small gap before anchor releases. As mentioned - bending the anchor is sometime needed. Try to get it right first, then we may concentrate on the second curtain. Not to complicate too much...... there is yet another critical adjustmrnt with IIIg that influences run of first curtain. This is adjustment of flash contacts. But this is separate story and impact on the run is later, after opening curtain is running. Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! But sometimes it is necessary to bend a bit anchor arm to achieve proper sequence (pins first, anchor second).So you might need to repeat this adjustemnt few time to get it right. And a short exdlanation to the role of anchor. It was introduced in IIIc, IIIb and below had only one place where shutter was hold after spanning and these were pins on sprocket drum. IIIb and below did not had ratchet on winding spindle, rather than, in order to prevent the whole transport to rotate back when spanned there was a special spring in wind spindle. Adjustment of this spring was very critical and time consumking - it shall prevent shutter and film to rotate back (under the tension of shutter springs) but in the same time, after spanning it shall go back just a tiny bit to reduce the tension on the pins. Sometimes you may oberseve following effect on IIIb and below - after spanning pressing the shutter goes hard. But if you rotate wind knob just a tiny bit back it goes then fine. In order to reduce this complucated adjustment and make releasing softier the anchor has been introduced together with the ratchet (well, the very first IIIc and IIId had anchor but still the same special spring as IIIb and below, but we shall forget oit here). In IIIc and above, when you are spanning there is a tension on the pins but then, when fully spanned ratchet allows a tiny movement back and the tension from pins is away, shutter is hold by the anchor only.-If the anchor is releasing too early then curtain move just a bit, so that the pins are catching. And this is not correct, pins shall have a small gap before anchor releases. As mentioned - bending the anchor is sometime needed. Try to get it right first, then we may concentrate on the second curtain. Not to complicate too much...... there is yet another critical adjustmrnt with IIIg that influences run of first curtain. This is adjustment of flash contacts. But this is separate story and impact on the run is later, after opening curtain is running. ' data-webShareUrl='https://www.l-camera-forum.com/topic/399193-iiig-slow-speeds/?do=findComment&comment=5785320'>More sharing options...
qqphot Posted April 12 Author Share #44  Posted April 12 I think this is working correctly so far. It's hard to video both the brake disc and the sprocket drum at the same time, but you can see that the pins on the sprocket drum and the silver gear below it are fully disengaged from each other before the rotation begins due to the anchor clearing the detent in the brake disc. I did not try to bend the anchor arm yet because I think the sequence is happening in the correct order now, but please correct me if I'm wrong. As you explained, while spanning the pins are engaged and tensioned against one another, but once fully spanned the ratchet allows the sprocket drum to back off a tiny bit and they are not tensioned against each other, there is a small gap and no pressure between them. As the release is pushed they move fully past each other and then the anchor releases and the curtain moves. pins_disengage_first.mp4   Also I've used feeler gauges to verify that the shutter is not released with a depression of 0.4 mm, and it is released with a depression of 0.25 mm, as specified in the diagram.  For what it's worth, when I tested it cold this morning the opening curtain did release immediately without a catch or delay, it could be random chance or it could be fixed... The closing curtain still waited too long on the first try, though. (its set to 1/125, on second try as usual it's fine). Link to post Share on other sites More sharing options...
Woodallp Posted April 13 Share #45 Â Posted April 13 Can I just say thanks to both of you for taking the time and making the effort. I am sure I will refer back to this many times in the future. 1 Link to post Share on other sites More sharing options...
qqphot Posted April 14 Author Share #46  Posted April 14 On 4/13/2025 at 12:44 AM, Woodallp said: Can I just say thanks to both of you for taking the time and making the effort. I am sure I will refer back to this many times in the future. Thank you, but really all the thanks are due to @jerzy for sharing his expertise. I just find it really educational to work through a problem with expert guidance rather than flailing around aimlessly. Link to post Share on other sites More sharing options...
qqphot Posted April 28 Author Share #47 Â Posted April 28 Advertisement (gone after registration) Well, it starts reliably, but still stays open too long when it's cold. I can't even really tell where in the cycle it's getting stuck now, I don't think it's where I originally thought it was. stuck.mp4 Â I suppose the next step is to try to get at the shutter spool bearings or something. Link to post Share on other sites More sharing options...
jerzy Posted April 28 Share #48  Posted April 28 possibly shutter will need to be CLAed again. I sonaooeed few frames from your video showing few steps of shutter run. 1 - speed is set to 1/250 - correct? Release button is pressed, opening curtain will start to run immediately 2 - pawl is being pushed away, shall releease closing curtain but it does bot run 3 - opening curtain is fully opened, but it bounced. you will need to adjust brake, although it will not cure the problem 4 - after some time closing curtain start to run, pawky is returning to home position This is reconstruction of steps, closing curtain is being hold but we do not know why. Try following (photo 5): hold shutter with your fingers where the orange arrow shows. Press and keep release, opening curtain shall not run. Release slightly pressure of your fingers allowing opening curtain to rotate slowly, stop at again after the pawl is pushed away. Try to observe what may hold closing curtain. Wait a bit with the shutter in this position and check if closing curtain will start to run after some time. If you want to do further experiments you may take lighter fluid and with syringe inject few drops where blue arrow shows. But I am afraid that you will need full CLA again, including opening small shutter drums and cleaning the springs inside Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/399193-iiig-slow-speeds/?do=findComment&comment=5793698'>More sharing options...
jerzy Posted April 28 Share #49  Posted April 28 Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! 1 Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/399193-iiig-slow-speeds/?do=findComment&comment=5793700'>More sharing options...
qqphot Posted April 29 Author Share #50 Â Posted April 29 Jerzy - as usual, you are right, second experiment you proposed >Â If you want to do further experiments you may take lighter fluid and with syringe inject few drops where blue arrow shows. I suppose this runs down the shaft into the springs and bearings and loosens old dried lubricant; I did as you said, and then let the camera sit with the shutter spanned over night and in the morning it fired properly instead of catching as usual. Of course this effect would only last until it dries out again but at least it's now clear what needs to be disassembled and cleaned. Link to post Share on other sites More sharing options...
jerzy Posted April 30 Share #51  Posted April 30 lighter fluid went to the upper ball bearing and along the shaft where the middle part of shutter drum (the one where closing curtain is fastened). So these are the places where old lubricant might still be. Shutter springs are within the smaller drums located to the right. They shall be as well opened and springs cleaned and lubricated. Link to post Share on other sites More sharing options...
jerzy Posted April 30 Share #52 Â Posted April 30 ...and the curtain brake shall be adjusted as well, opening curtain does bouncing and this is not good for shutter drum... Link to post Share on other sites More sharing options...
qqphot Posted May 13 Author Share #53 Â Posted May 13 this is on its way to yye to be CLA'd with specific instructions to be sure the bearings and the springs inside the drums are cleaned and relubricated, and for the curtain brake to be adjusted, among everything else. We shall see what new problems it returns with! Link to post Share on other sites More sharing options...
qqphot Posted June 1 Author Share #54  Posted June 1 (edited) On 5/12/2025 at 10:31 PM, qqphot said: this is on its way to yye to be CLA'd with specific instructions to be sure the bearings and the springs inside the drums are cleaned and relubricated, and for the curtain brake to be adjusted, among everything else. We shall see what new problems it returns with! Well, this is too bad - Youxin Ye sent an email back saying he read my requests and won't work on it because he does not disassemble cameras far enough to access the shutter drum bearings and springs. "We only do necessary services for the user market. We do not take a camera wholly apart and rebuild a camera like this." I suppose his service only involves applying some oil to easily reachable areas.  I wonder if anyone knows of someone who works on these cameras who offers a more advanced level of service? Edited June 1 by qqphot Link to post Share on other sites More sharing options...
jerzy Posted June 2 Share #55  Posted June 2 well, this statement wonders me, cleaning and lubricating shutter springs, in my understanding, is part of any regular CLA. Here is example of IIIf red scale, notice white depositis in the spring - this is old, dried lubricant, and some dirt on it. All this needs to be cleaned and lubed again Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! 1 Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/399193-iiig-slow-speeds/?do=findComment&comment=5811324'>More sharing options...
qqphot Posted June 2 Author Share #56  Posted June 2 30 minutes ago, jerzy said: well, this statement wonders me, cleaning and lubricating shutter springs, in my understanding, is part of any regular CLA. Here is example of IIIf red scale, notice white depositis in the spring - this is old, dried lubricant, and some dirt on it. All this needs to be cleaned and lubed again Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members!  This picture is helpful because now I understand what they look like inside! Your explanation makes sense. It seems the drums and therefore also the shutter cloth would need to be taken out in order to do it right, so maybe he tries to avoid that.  I also thought that cleaning and lubricating these would be part of a CLA, but I suppose some camera owners have quite low expectations! Here is what he said: "We only do necessary services for the user market, also considering the value of a camera. We do not take a camera wholly apart and rebuild a camera like this. To achieve such a goal, not only does the camera have to be wholly apart to rebuild all shutter parts, but the curtains also have to be replaced. When the curtains get aged, in long time storage, the rubber side ages, it will also stick to the drum and affect shutter speeds." For what it's worth, I didn't see any sign of deterioration on this camera's curtains on either side, when I had it open, nor do I think that the curtain is sticking to the drum. The fabric felt flexible and dry, not sticky. Link to post Share on other sites More sharing options...
jerzy Posted June 3 Share #57  Posted June 3 it is not required to remove curtains whane you want to open small drums and clean/lube curtain springs. For older svrewmount, pre IIIf red dial, it is sometimes needed to remove one ribbon in order ot open the drum. But the rest (ribbons and curtains) stay as they are and are replaced when rubber detoriates only. Different story is with the big, main drum - with exception of very first types of shutter (pre II) you cannot take it apart easily, without special tools, I suppose. But there are no springs there, it may be cleaned and lubed without taking apart. And the ball bearings are accessible when the shutter is taken out of the crate. Btw, for ineterst - there are two ball bearings on the main shutter drum, one consists of lose balls (1mm), the other one, in upper part (right on the photo below), has already a sort of cage, and shall be cleaned without taking apart (correct positioning of the parts of cage is critical for proper function of shutter).' Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! And one remark more, why I think that cleaning shutter is valid for all users - dried lubricant crete additional friction, often you may hear it as well on some speeds (1/40). And this means that the part of spring energy that is supposed to drive the shutter goes into generating the noise which is not good. On the other side, opening and cleaning drums is additional effort of up to 1 hour and this has an impact on CLA price 2 Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! And one remark more, why I think that cleaning shutter is valid for all users - dried lubricant crete additional friction, often you may hear it as well on some speeds (1/40). And this means that the part of spring energy that is supposed to drive the shutter goes into generating the noise which is not good. On the other side, opening and cleaning drums is additional effort of up to 1 hour and this has an impact on CLA price ' data-webShareUrl='https://www.l-camera-forum.com/topic/399193-iiig-slow-speeds/?do=findComment&comment=5811595'>More sharing options...
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