Zenit Shuttercurtain tension adjustment

This has to be done if one curtain travels too slow. These instructions are ment for all Zenits with cloth shutter curtains.

These are, Zenit, Zenit-C, 3, 3M, Kristal, E, B, EM, BM, ET,10, 11, 12, 122, 312 and the 412. And it also works on the Rangefinders Zorki 6, Zorki 4 and Zorki 4K.

Tensioning the shutter curtains ain't as hard as people think. The most common problem is that the second curtain roller isn't properly tensed. This leads to a gap on the left. Which causes a vertical band across photos.
This problem can also be caused by a lack of lubrication.



Remove the bottomplate by removing the four screws as seen on this shot. Almost all Zenits with cloth shutters have the same bottom. Some models may have the tripod socket in a different place.



With the bottomplate removed you will see two cross-shaped nuts (left side in this shot). In this shot the mount is on the botton of the shot and the camera's back on the top of the shot. The upper nut in this shot tenses the first curtain. The bottom nut, closer to the front of the camera, tenses the second curtain and this is the one that should be thightened. Also in this shot you will see a part of the shutterbutton return spring (big black leverplate on the upper right) The cross-shaped nut here (located almost in the middle) is for tensioning the spring of the mirror return.



Remove the locking screw head first this is the tiny screw placed between the slots of the cross shaped nut. In this shot one is allready removed. In the middle of the cross shaped nut, there is another screw, this is turned to tense the shutter. If the tension was relaxed, turn this COUNTERCLOCKWISE four times. You should feel the spring underneath tighten. If the tension wasn't released by removing the locking nut, give the tensing screw one turn to increase the 2nd curtain's tension. Give the cross-shaped nut a bit of a turn, CLOCKWISE, to tighten it and position one of its slots over the hole where the locking screw goes in.

Replace the locking screw again. If the gap remains, give one half or one turn more. DO NOT OVERTENSE. You can break the screw or the spring inside. And if that happens you will have to get a scrapcamera to replace the roller. If the gap remains, the gears could be dirty or lacking lubrication.




If the shutter has a problem at 1/30th only. Then two things may be causing this. The Shutter may hang at the leather at the back of the mirror, you can see this at the B setting. It can in some cases be fixed by rubbing in a bit of talcum powder in the leather. Or to adjust the cross-shaped nut (located almost in the middle) seen in the shot above. This may be 1/2 to 2 turns.

Recap

  • A warning about the tensioning screws Do not tension them too much this can break the springs inside the rollers.
  • The first curtain should work with 4 to 4 1/2 turns from "zero" tension. The second, with less, just enough so that the curtain can close fully regardless of the way the camera is held.
  • The little screw locks the cross ("clover") nuts in place. To tense, the (even smaller) screw to which the nuts are threaded should be turned. This cannot be done without removing the locking screws first.
  • Tensing should be done with the curtains reeled on their respective rollers. This means the camera is uncocked (fired).
Many thanks to Jay Javier and Jon Goodman for their help on this difficult subject.