Zorki 4 shutter problem

[joshw]

Hello everyone!

Firstly, I should say that I have pretty much no hands-on experience with film cameras. I was born into the age of digital, and I don't know what overcame me to buy an old FSU RF. Anyway, I finally took delivery of a Zorki 4 and FED 2 today (I can't believe how cheap they are!)

I've come into a problem with the shutter release mechanism on the Zorki. I'll do my best to describe what happens, and I'd be extremely grateful if anyone can help me at all.

When I press the shutter down (usually faster speeds around 1/250), there's a half-click, as if the curtain moves slightly, and when I release my finger, then the shutter fires. I took off the back to observe this, and noticed that the curtain does in fact move a few millimetres when I press down initially, and then finishes firing when I release. I know that this definitely isn't normal because the shutter should fire in one smooth action; not an initial jerk, then normal fire.
(I can take a video of this if my description was too confusing.)

Does anyone know what I should do next? Is this a curtain tension problem? Or should I be trying to clean the firing/shutter mechanism as per the CLA guide (though I fear damaging my 'new' camera...)?

I don't think sending it to get fixed is really an option because I'm all the way down in Sydney. I am yet to put a single roll of film through it, and I want to get it right the first time. Any help would be greatly appreciated!

I hope this isn't the beginning of a very slippery slope...

Cheers,
Josh

 

[Alpacaman]

I had that happen, loosening the tension on the curtains fixed it. I am not actually sure of what caused it to jam like that, though.

 

[john neal]

Josh,

My guess is that there is a problem with the release cam inside the top plate, or the tension in the spring that manages the release cam, but see if you can contact Wolves 3012 on here, he will most likely know.

 

[wolves3012]

I think John Neal has made an accurate assessment of the likely problem. Firstly, take the back off the camera and fire the shutter on a "problem" speed - check to see if there's any exposure at all. My guess is that there won't be any gap in the curtains and there's no exposure.

Here's what's going wrong: when the shutter is released, both curtains start to travel at once. The second curtain's shaft, however, has an arm on it. This arm gets trapped by a crescent-shaped arm which descends as the release button is pressed. The first curtain shaft also has an arm, in a variable position (according to what speed you've set). This arm knocks aside the crescent-shaped catch after the required curtain gap is reached and the second curtain follows the first across the frame.

The crescent-shaped catch is tensioned inwards and downwards by a light spring. If the spring presses too hard, the first curtain can't push it aside and it stops, held back by the catch. Releasing the shutter button lifts the catch anyway though and both curtains are then freed but there is no gap and no exposure.

Causes are a grossly under-tensioned first curtain (unusual but possible), general dried-up grease on the catch/arm or a generally poor-running shutter in need of a CLA. The small spring that tensions the catch can be bent slightly so that it puts less inwards pressure and that will most likely cure the problem. All the parts I've mentioned are clearly visible in the photos of the Zorki 4/4K CLA sticky. If you're confident with a small screwdriver and some basic tools, go for it. If you're not, it's better left to a professional and then it'll probably cost more than the camera is worth, sadly.

 

[joshw]

Hi everyone,

Firstly, a quick thanks for all your help, especially wolves3012.

I had a go at tensioning the first curtain yesterday before I read your reply, and it seemed to do the trick! I've got the shutter firing smoothly now, 10 out of 10 times (so far). Not 100% sure on the speeds yet, as I fear I may have tensioned it a little too much. But, at least it's firing properly! Wolves, thank you for your (very) detailed explanation, but I don't think I've quite got the skills to work my head around all that just yet. Maybe someday!

Another quick question if anyone is able to help:

As I mentioned, I bought both an FED-2 and a Zorki 4. The shutter winding mechanism feels really stiff on the Zorki 4, there's quite a lot of resistance. It's very smooth on my FED-2 though. After winding it about 30-40 times on the Zorki, I was starting to get a blister on a finger!

Is this normal?? I suppose it isn't, so if anyone can help, precise what part of the camera should I be looking to service/CLA?

 

[wolves3012]

Hi everyone,

Firstly, a quick thanks for all your help, especially wolves3012.

I had a go at tensioning the first curtain yesterday before I read your reply, and it seemed to do the trick! I've got the shutter firing smoothly now, 10 out of 10 times (so far). Not 100% sure on the speeds yet, as I fear I may have tensioned it a little too much. But, at least it's firing properly! Wolves, thank you for your (very) detailed explanation, but I don't think I've quite got the skills to work my head around all that just yet. Maybe someday!

Another quick question if anyone is able to help:

As I mentioned, I bought both an FED-2 and a Zorki 4. The shutter winding mechanism feels really stiff on the Zorki 4, there's quite a lot of resistance. It's very smooth on my FED-2 though. After winding it about 30-40 times on the Zorki, I was starting to get a blister on a finger!

Is this normal?? I suppose it isn't, so if anyone can help, precise what part of the camera should I be looking to service/CLA?

It's not normal for the winder to be stiff, you're right there! That can be caused by over-tensioning the shutter, although it has to be pretty bad to have such an effect. If the shutter is free-running and properly lubricated you should be looking at about 3-4 turns tension on the first curtain and 2-3 on the second. If that's not the cause, you need to clean and lubricate the winder shaft and the gear-train that it turns. Unfortunately, to do the job properly you do still need to take off the top cover. If it's never been CLA-ed those gears are probably gummed up with dried grease.

For reference, I can wind most of my knob-wind FSUs with the side of one finger, certainly when there's no film in them anyway!