tho60
Well-known
I have purchased a Zorki-4 from 1961. The second curtain does not run at all. The first one goes as far as the chosen speed allows. I took apart the camera but I did not find any obvious hindrance (dirty channel, weak tension roller etc.).
What can I do?
What can I do?
wolves3012
Veteran
If the second curtain never releases, there are two likely culprits. First, the usual the second curtain latch which is the crescent-shaped arm close to the speed change mechanism. It should be under tension inwards and downwards and when you press the shutter button it should move down. Second candidate is the latch operated by the slow-speed mechanism cam. If that is stuck or mis-fitted or the slow-speed escapement is removed/not fitted correctly it will block the second curtain permanently.
tho60
Well-known
Thank you very much. What could be the remedy?
wolves3012
Veteran
For the "regular" latch, take off its spring, pull up on the crescent-shaped arm and remove it. Clean it, lightly re-lubricate it, refit it & the spring and watch to see if it moves down when you press the shutter. For the slow-speed latch, take off the slow-speed mechanism as per the sticky, then physically check that the spring-loaded latch is free to move & spring back. If it's not stuck, hold it back manually while firing the shutter and see if the curtain closes. The causes of failure of either latch should be fairly easy to find and obvious: bent/damaged/missing/broken parts etc. If the shutter has been fired and the second curtain remains open, you can manually operate each latch to see which has failed to release. The curtain will close when you operate the stuck latch. Note that with the slow-speed escapement removed, its latch will ALWAYS fail to release though.
wolves3012
Veteran
There were variations during the long production run, some differences are inevitable, sorry.
Correct, that's a mistake on my part. As long as it's dropped into a "fast" speed it's fine. The further from the "slow" ones the less likely a mistake will be made.
Wind it to the corresponding position. If you're unsure, position the slow-speed escapment roughly in position and note where the speed selector is sitting below it. Make a mark on the ring of the slow-speed escapement that corresponds with the selector position. Now take the slow-speed escapement out and wind so the pin is further than the mark (i.e. further anticlockwise when viewed as if fitted).
If you've re-fitted it with the pin in the wrong position, the slow-speed escapement will not work properly. It can be fiddly to get it right but a dozen times suggests a fundamental problem you're not seeing.
Ron (Netherlands)
Well-known
Don't think you missed a step. Actually the slow speed escapement from the 4 and 4K are the same (I serviced about 35 of these camera's made in different years and they were all the same). There are two important aspects that are not described in detail on the net (although I find the HOW TO very detailed!). Further there is a possibility you cannot put it back working if you don't know how the escapement does the job.
This might help: First note that the slow speed escapement has 3 elements that 'work' together, they coincide: the pin on the big gear, the cam and the black lever:
1. There is the basis on which the clockwork (i.e. the gear assembly) resides with two screws, and which can be seen if you have taken off the clockwork for cleaning.
This basis contains a very important part of the escapement: the black lever that will hold the second curtain lever in case a slow speed is chosen. Anyway this lever should be in its position holding the second curtain lever when the clockwork has been removed. If not then there can be two faults: the black lever is faulty: it should be easily movable under the basis between the two little screws with are holding it at its place.
If there is oil under the latch, you have to clean it: THIS PART MAY NOT BE OILED!.
Second - and more severe if not working - the black lever is pushed by a very tiny spring. This spring may be out of position or even lost (I got some Zorki's where there was no spring inside - I guess lost during a previous 'service'). This spring is easily overlooked since it is sitting inside the basis and you might only see a very small part sticking out: the part sticking out should rest against the back of the black lever. Now if the black lever is working fine and the clockwork is cleaned and lightly oiled, you can go further installing the clockwork;
2. Before installing the clockwork, set the speed selector @ 1/125 sec or 1/100 (depending how old your camera is). Next be sure you have the camera with its lens hole in front of you.
Now take the speed selector in your hand and turn the big gear ccw as described in the HOW-TO… Sometimes it should even be turned 2 times in stead of 1,5 (and YOU SHOULD HOLD THE BIG GEAR AFTER WINDING AT THAT POSITION).
3. Next thing to look at is the cam (so-called in the HOW TO), it is a little ‘foot’ sitting at the end of an axle sticking into the central gear. The cam has a round shape but not at one part, there it has a pin point (look at the photo in the HOW TO).
The position of this cam is very important: the pin of the cam must rest against (not on!) the black lever described above. By doing this, the cam can push the black lever back, so the second curtain latch can run freely. However if the big gear is turned ccw, the central gear will do the opposite together with the cam, and the cam will release the black lever, so that it will obstruct the second curtain lever.
Some times I did find clockworks put wrongly back in a way that the cam was resting on the black latch – so the black latch was arrested by the cam. Therefore one should check whether the black lever moves back and forth when turning the big gear cw and ccw.
3. When putting the clockwork over the shaft of the speed selector there are two things to be looked after:
a. as said, the cam must rest against the black latch, and therefore not sitting on it!
b. and the pin on the big gear must be positioned in front of (so towards you) at least before the (upright) pin of the speed selector.
After you have positioned the clockwork over the speed selector and hold the clockwork at its position - YOU CAN RELEASE THE BIG GEAR. When set free the big gear will turn a little clockwise until the cam will rest against the black lever pushing it backwards.
4. Next the two screws holding the clockwork can be put back in place – but you shouldn’t fasten them, since you first have to check whether the escapement works correctly.
CHECK:
1. After installation, you should be able to pull up the speed selector shaft freely, it shouldn’t be obstructed by the pin of the big gear. If it is obstructed you should loosen the two screws of the clockwork a little and try to move the clockwork a little towards you. Check again if the pin is obstructing the speeds selector. Sometimes you can't get the pin at the right position because someone might have tampered with the clockwork, but for now I presume that you have a good one;
2. Turn the speed selector at a slow speed, e.g. 1/8 sec. The selector should rest and push against the pin of the big gear. By doing that,….
3. …the cam of the clockwork should release the black lever, in order to arrest the second curtain lever.
good luck
Ron (Netherlands)
Well-known
Glad to be of help. Your camera looks great - one with the engraved name. Enjoy!
Ron (Netherlands)
Well-known
Thanks!
Thank you, thank you, and thank you once again. If you ever find yourself in Chicago, let me know, I owe you a couple of beers!
Being able to repair a camera yourself is - as you obviously have experienced - really very rewarding and can bring great joy.
and many thanks for the invitation, let you know when I'm around