Wobbly restrictive gear in Zorki 1

[Chacha]

I was taking apart my new zorki to change the curtains and clean everything but i noticed the restrictive gear is pretty loose and tilts a lot when advancing and releasing which worries me...
I was thinking about puting a tiny washer on top of it where there is a space, if i can even find one.
Would that be a good idea or could it interfere with it's movement ?

 

[GMOG]

I'd take that wheel out to get a better look at it and the post it rides on. There may be a simple solution you can't see with the parts installed. Can you take it apart by removing the screw that's visible from underneath?

 

[Chacha]

I did several times but i don't see anything strange, the screw and the gear are both in good shape. Looks like there's just nothing to hold it in tight.
I've never disasembled a zorki 1 before so maybe i miss something...
Here's a few shot to illustrate better :

 

[Chacha]

2 more close up of the screw and gear

 

[Livesteamer]

I think the real problem is that the gear is too loose on its shaft, allowing the gear to wobble. Could a new, slightly larger shaft be made? Good Luck. Joe

 

[GMOG]

Interesting. The screw that serves as the shaft appears to be a modified screw as opposed to a factory made part. I'm not familiar with Russian stuff, though. I agree that the wheel should stay more flat.


That's a lot of end play, more than seems right. How much side shake is there between the wheel and the shaft? If that's excessive too I wonder if there was a bushing in there to take up the extra space. If the side-to-side fit is good enough I would make a spacer to fill that gap up top. You might could stack up some washers, too.

 

[Chacha]

Thanks for your replies 🙂
What's strange is that the larger part of the shaft fits ok in the gear with very little play and side shake (as seen in picture 1 of my second post), but when installed inside the shutter crate it's just not long enough to go all the way through the gear and up to the top of the housing (as seen in picture 2 of my 2nd post), i think that's what allows it to tilt that much.

I cleaned the screw and took a better look and you're right, it doesn't really look "factory like", the metal work is kinda messy.
Plus it looks different from the screw seen in a "step by step zorki 1 reassembly" video on YT but it could just be that the design changed over the years. I didn't find any other close up image of that screw online.

Unfortunately i do not have the skills nor tools to make a new shaft but i could try to make a spacer.

I'll post a picture once a find a solution 🙂

 

[GMOG]

What's strange is that the larger part of the shaft fits ok in the gear with very little play and side shake (as seen in picture 1 of my second post), but when installed inside the shutter crate it's just not long enough to go all the way through the gear and up to the top of the housing (as seen in picture 2 of my 2nd post), i think that's what allows it to tilt that much.

So limiting end play is the goal, then. Simple enough! 😉


I'm curious to hear from other folks who've been through these cameras. I've only messed around with Leica rangefinders so far, and they aren't built the same.

 

[wolves3012]

The play is certainly excessive. The screw looks to me as though the restrictor gear has worn the threads away. It's been too long since I took one of these apart but I'd have thought it should have had a shouldered screw not a plain one. Possibly it's been replaced with the wrong part or maybe the factory ran out and used what they had, you'll never know. I would be trying to source a proper shouldered screw though. Fitting a washer or sleeving the screw will only keep the problem at bay for a while, although it may be the route you have to take.

 

[Chacha]

Yes the threads could very well be worn out by the gear because it has a groove arround its shaft that sits perfectly on them but they don't go through the crate (anymore?).
What do you mean exactly by shouldered screw ? (i'm new to repair and diy plus english isn't my native language). From what i saw online it's a screw with some kind of sleeve between the head and the threads

 

[Livesteamer]

First, Welcome to the forum. Your English is very good and many of us here have not mastered a second language like you have.


The screw/shaft that the gear runs on is a very ugly, poorly made part. I say this as a retired machinist. The part of the shaft that the gear rides on should be very, very smooth and of a very precise diameter. This is an example of poor quality control by the Soviets. The lathe machinist should have thrown away that shaft and the assembler should have never used it. Replacement with a good screw/shaft is your best option. Good Luck. Joe

 

[farlymac]

I just took the screw out of my decommissioned Zorki-1d/b, and after cleaning off the excess lubricant it looks quite similar to yours. I haven't done a complete teardown, so I can't say what condition the gear is in, but it didn't have the play that yours displays. Like I said though, there's lots of old lube in there, so that could be helping it.


PF

 

[Chacha]

Apart from buying another zorki just for the screw (wich would be quiet sad in my opinion) i don't know if i can find one. I thought about getting it 3D printed but i don't think it would be precise enough.

Ok that's interesting. Mine was quiet the opposite, there was almost no lube inside

 

[Livesteamer]

It is not a complex part. Do you know someone with a lathe who could make you one? Perhaps a technical school would use it as a student project. If we lived closer I would volunteer.


A bit of thicker lubrication and a thin washer might be your simplest solution. Joe

 

[Chacha]

Unfortunately i don't know anyone with a lathe but i'll try the washer and thick lubricant tho finding one thin enough is more difficult than i thought. I may have better luck in a model shop

 

[GMOG]

I'd not use a thick lube on this wheel, because it is connected to the 1st shutter curtain and needs to move quickly when the shutter is released. A thick oil or grease could act as a brake and interfere with shutter timing, especially when cold.

If you have a washer with the right sized hole but is too thick, use an oil stone to make it thinner. Fine grit abrasive paper adhered to a flat surface could also be used.

Another option might be found in the world of clocks, in the form of ready made bushing that could be modified, made thinner, to fit. There are many styles and sizes available from a variety of suppliers. Here's a clock trades supplier here in the USA:
https://timesavers.com/c-325538-clock-repair-replacement-parts-bushings-related.html


If you decide you want assistance I think it would be possible to find a competent clock or watchmaker somewhere in the vicinity of Paris, France. Could be a lot of fun to visit an old school clockmaker's shop, with a camera of course.

 

[wolves3012]

What do you mean exactly by shouldered screw ? (i'm new to repair and diy plus english isn't my native language). From what i saw online it's a screw with some kind of sleeve between the head and the threads

A shouldered screw is one where only part of it is threaded, the rest is plain, non-threaded of a suitable size. It would look something like you have but not look so badly made.


If you don't have any access to machining facilites, you may just have to do the best you can with a washer and see how it lasts. At least it won't be worse than what you have now.

 

[Livesteamer]

There may be other options such as building up the shaft with a thin layer of epoxy and then carefully filing and sanding it down to a good fit on the gear. It might also be helpful to polish the inside diameter of the gear with some very fine sand paper and a wooden dowel a little smaller than the hole. Epoxy is not a great solution but it might work. Good Luck, Joe

 

[Chacha]

I finally had the time to fix the problem, i managed to find some small washers and a small brass tube. I made some kind of ring to widen the top part of the shaft (by cutting the tube and filing it, took a lot of tries to get a good one) and then added a filed washer. There almost no play anymore
thanks for your help !

 

[SyPat]

(...) I made some kind of ring to widen the top part of the shaft (by cutting the tube and filing it, took a lot of tries to get a good one) and then added a filed washer. There almost no play anymore !

Did you noticed an improvement in the way the shutter behaves?