Zorki 4k CLA Troubles

[Zorki74]

I'm in the middle of CLA and everything went great to the moment I have unmounted slow mechanism. I managed to clean it and lubricated and installed again. However after refitting it wasn't working properly as it should.

So I tried to cock and release mechanism few times and change speeds. However something went wrong and at the moment shutter is stuck open.

I am able change speeds however it doesn't change anything. I am also able to cock is again but after releasing curtain goes back to open position. I might change speeds before cocking 🙁

I will be extremely happy for help or any suggestions

 

[Zorki74]

I have checked I am able to change speed only without cocking the shutter, however after shutter has been cocked I'm unable to even list the speed dial :bang:

 

[wolves3012]

Most likely you didn't re-install slow-speed mechanism correctly. There is a small cam on the underneath of it, it's easy to have that sitting on top of the catch for the second curtain. This will cause the problems you describe, so take the mechanism back out and re-fit it carefully. Are you using the CLA guide I wrote? That explains how to re-fit correctly.

 

[Zorki74]

Hi wolves3012, thank you for your reply.

Yes I'm using your guide, but this was the part I couldn't fully understand. What exactly do you mean by the catch for the second curtain release?

Here it's what it looks like now:

The speed is set to 1/30 but can be changed before cocking. Could you describe for me how to fit it? Also, when I'll fit it correctly what speed I should set and what to do next? I'm sorry for such a detailed questions but I want to avoid any further mistakes 😱

 

[wolves3012]

Ok, no problems asking detailed questions! Look at the slotted speed-selector disk, sort of gold colour in your photo above. To the left of it you see a small, sliding, black plate. That is the second-curtain latch for slow speeds. If the mechanism isn't fitted at all, you'll find the second curtain will never close if the shutter has been cocked and it's because of that catch. Sliding it to the left will release the trapped second curtain.

Look underneath the slow-speed mechanism, you'll see one of the shafts poking downwards and with a small, snail-shaped cam on the end. When you fit the mechanism, the pointed part of the cam *must* sit beside the release catch mentioned above and *not* on top of it. Hence the need to wind the mechanism and hold it wound-up while re-fitting - don't let it unwind until you have the screws in place! Once fitted, you can loose it and it won't unwind much if fitted correctly.

As for what speed you set, as long as you have set one of the "fast" speeds, it doesn't much matter which one. Do this before re-fitting the mechanism. Probably the best choice is 1/30th because it's the furthest away from the "slow" ones.

 

[Zorki74]

Yes, I slid it to the left and the curtain closed! 😀 Thank you so much! I will now try to fit slow speed mechanism correctly. However I think I should previously clean bottom part of the camera as I see there is a lot of old grease that doesn't help at all.

Do you think it's better to fit the slow mechanism at this stage or it can wait till the end?

 

[Ron (Netherlands)]

Yes, I slid it to the left and the curtain closed! 😀 Thank you so much! I will now try to fit slow speed mechanism correctly. However I think I should previously clean bottom part of the camera as I see there is a lot of old grease that doesn't help at all.

Do you think it's better to fit the slow mechanism at this stage or it can wait till the end?

Sometimes it is easier to reinstall the slow speed escapement if the speeds selector shaft is set to 1/125 sec position. In that case the slow speed selector doesn't obstruct the mechanism.

 

[Zorki74]

One more question. I have managed to clean all the parts and the bottom of the camera as well. However I still have problems with slow speed mechanism. I know how to fit it, that's not the problem anymore, but when I fit it and I set fast speeds it seems that pin from slow speed mech is too low and jam with selecting pin. Does anybody experienced anything like that? I also noticed B doesn't work but I tested without slow speed mech so maybe it will start when I will refit slow mech.

I though maybe because when I dismantled selecting pin I reassembled on the wrong speed. But is seems that it doesn't matter for the mechanism, right?

I will be grateful for any suggestions

 

[Ron (Netherlands)]

One more question. I have managed to clean all the parts and the bottom of the camera as well. However I still have problems with slow speed mechanism. I know how to fit it, that's not the problem anymore, but when I fit it and I set fast speeds it seems that pin from slow speed mech is too low and jam with selecting pin. Does anybody experienced anything like that? I also noticed B doesn't work but I tested without slow speed mech so maybe it will start when I will refit slow mech.

I though maybe because when I dismantled selecting pin I reassembled on the wrong speed. But is seems that it doesn't matter for the mechanism, right?

I will be grateful for any suggestions

Can you show a picture of the reinstalled slow speed escapement, since I have the idea that it still isn't put back right on.....
In order to have an idea whether it was put back in right position, where does the pin of the slow speed escapement reside when it is not wind on?

 

[Zorki74]

Hi Ron, Thank you for your reply. Yes indeed it was still wrong but today I managed to fit I correctly as all the slow speeds works fine! 😀

However there's still something wrong with fast speeds as it seems that the curtain doesn't open at all (that's why B doesn't open as well)

Please have a look at these pictures:

I also made sure that selection pin is screwed firmly, however now I think maybe that's the reason why shutter curtain doesn't open on fast speeds? Which element is responsible for opening curtain?

I will be extremely grateful for any suggestion. Also thank you so much for your help so far. You guys are the best! 🙂 I'm afraid I'm a person who grew up with computers and I'm more familiar with software than mechanics 😛 But I really want to learn, so hopefully I will put it together successfully 😱

 

[wolves3012]

I'm a little puzzled by the second photo above - is the shutter cocked in that or not? If it is cocked, all looks good.

Here's a rundown on how the shutter works, hopefully it will help. When the shutter is wound, the sprocket is advanced to pull the film. On the bottom of the sprocket is a pin, which engages on a pin on the small gear below, which in turn moves the restrictor gear, that pulls the curtains across via the large drum. Once wound, there's a little catch that holds it cocked, plus the ratchets on the winding gears.

When you press the shutter release, that disengages the driving pins and sets both curtains free at once. The first curtain opens. The second curtain is held by one of two catches, depending if the slow-speeds are in use or not. If you set a fast speed, one latch is engaged by the crescent-shaped arm (the catch can't be seen in your photos but look under the selector brass piece to find it). After a certain revolution of the drum, this latch is pushed aside to allow the second curtain to close (except on 'B', where it doesn't release until the crescent-shaped arm lifts).

On slow speeds, the latch I mentioned in the post above is engaged because the cam underneath the slow-speed mechanism turns around and allows it to slide. This latch remains in position until the clockwork unwinds and the cam pushes it back, releasing the second curtain.

Now, look carefully at the speed-selector brass piece. It has slots that are deeper for the fast speeds, so the alloy part sits lower. On slow speeds, the slots are shallow and the alloy part sits higher, so it engages with the pin under the large ring gear of the slow-speed mechanism and winds it up when the shutter is cocked.

 

[Zorki74]

Hi wolves3012. Thank you for your reply. The second picture is from the front and all pictures shows the mechanism in not cocked position.

Here's how it looks cocked, set on 1/60 (where slow speed mechanism is not engaged yet but it is higher) (from the front)

By crescent-shaped arm do you mean second curtain release pin shown on Picture 26A in your CLA thread? If I'm right on fast speeds after cocking the shutter, the speed selecting pin turn clockwise and push aside second curtain release arm (photo 26A). Probably the whole turn takes 1/30 sec that's why this speed moves release arm after almost whole turn. With B it actually never touches release arm. However, in my case for some reason second curtain is released straight away and not hold at all 😕.

I did research online and some people suggests to adjust tension of shutter curtains? What do you think? I remember when I bought this camera about 2 moths ago link between curtains actually wasn't straight. But after using it for some time is self regulated. Now I see that the plastic link between curtains don't hides when mechanism is not cocked.

However when cocked it's quite loose. The camera hasn't been used for many years and I read it's normal. Would this cause problems with fast speeds?

 

[wolves3012]

From that photo things look good, looks very much like the slow-speed mechanism is fitted correctly. The crescent-shaped arm is indeed the 2nd curtain latch, yes photo 26A. From how you describe, I think your understanding of how it works is correct.

On the curtain tensions, the curtains should not be too slack when uncocked and yes, if the tensions are wrong it will cause problems. To be honest, if you have just CLAd the camera, it should not take much tension to operate.

If you are unsure, I would suggest carefully releasing the tensions and counting how many turns are on them. The tension figures are with the shutter UN-cocked. Keep a screwdriver in the middle slot, remove the tiny locking screw, release the locknut (left-hand thread) and then allow the screwdriver to turn slowly, counting, say, half-turns. You should find there is somewhere around 4-5 turns on the first curtain roller and 3-4 on the second. There should be a turn or two more on the first curtain roller than the second.

If you do alter the tensions, do you have access to an old-style computer monitor with a CRT display? That makes getting the tensions right much easier!