First curtain stops in picture frame

[Hubregt]

Hello,

I am new to this forum and with the help of all the information I have found here I have serviced a 1961 Zorki 4 that failed on the low speeds. The only thing I did not dare to do was taking off the vf and rf to lubricate the top roller pivots. For the rest I have opened, cleaned and lubricated all.

The low speeds now work, but the first curtain stops too soon
, blocking about 4mm of the picture. Any suggestions to solve this?

Hubregt

 

[p81]

Spray with some tunerspray on the gears and take some empty shots without film. Look if that solve the problem. If so, give some light oil on the gears, because the spray will volatilize and you have the same issue as before after a few days.
My suggestion helps only, if at the shutter was no tuning.

 

[Brambling]

the first curtain stops in the frame-
1. there is not enough force at a spring-to pull a sleeve of the first curtain.
2. the braid or edge of a curtain for something is lifted up-to examine attentively, perhaps, to move away a little a light-proof a frame.
3. somewhere a piece of film has fallen and prevents the curtain from reaching the edge - to study.
4. pay attention to the brake at the bottom, it should slow down the curtain a little, and not stop the movement-there you can bend the tongue a little.
And many other problems...

 

[Hubregt]

Thanks

Thanks

Thanks for the suggestions. I will give them a try and will let you know the results.

Hubregt

 

[Hubregt]

I have opened the camera again. Cleaned and lubricated gear again. Did not find any dirt or film debris. When I operate the camera without the low speed gear I notice that:

At B the first curtain almost travels to the starting position. With my finger I can make it make the last two millimeters and I do see the speed selector rotate with it.
At 1/125 the first curtain stops at about 8mm from the right, looking from the film side. Releasing the second curtain by hand make both curtains travel to the starting position.
at 1/250 the first curtain stops at approx 4mm
At 1/500 at approx 2mm

When I reattach the low speeds unit the curtain stops at random places. Touching the big gear sometimes helps.
In taking off this unit I found two thin washers over the big hole exposing the lever for releasing the second curtain. Replacing those washers or not does not change the behaviour.

I do notice that quite some force is needed to free the lever for releasing the second curtain, freeing it from the pin on the speed selector.

How should I proceed? Any suggestions are welcome.

Hubregt

 

[Ko.Fe.]

Was shutter removed? Were both curtains drums springs removed with thier axels, washed and relubed?

 

[Hubregt]

No it wasn't.

But rethinking. I think that the high speed behaviour is as to be expected. With the low speed unit removed, the lever preventing the firing of the second curtain is activated. That explains normal behaviour when I activate it by hand.

I think now that I did not pay enough attention to the position of the cam operating this level in replacing the low speed unit.

What remains then is that the first curtain does not completely return to the starting position. Perhaps I should tighten the spring with half to one turn?

 

[Hubregt]

Yes that was correct. After carefully replacing the low speed unit, all speeds seem to be ok.

I also think that I have messed up in naming the shutter curtains. What I call me 1 might be nr 2.

What I see now, looking from film side to lens side is that when I activate B or low speeds, I see a curtain moving from right to left and stopping a little bit too early, just having the metal rim in the picture frame.

I am wondering if I can solve this by increasing the curtain tension.

 

[Hubregt]

That did the trick!

The camera is fully functional now. I will put in a film now.

Thanks for all the support and suggestions.

Hubregt