Nice Zorki 3M becomes stiff when focussing

[pordiosero]

Hi all;

About one month ago I bought a nice Zorki 3M from 1955. The telemeter was really disadjusted, so I decided to adjust it for infinity and 1m... after many attemps, it was performing more or less ok.

Recently I changed the leather to another camera, and I said to myself : "ok, why not to remove this horrible and painted vulcanite, and warp the metal with nice and smooth leather? So, and now comes the stupid thing, I have removed the mount ring, removed also the already rotten shims (thinking that I could always put them back or put some new), and check how the vulcanite looks under the ring.

Well, after screwing again the mount ring, I tried to screw the lens, and I found it much more... hard? not loose at all! Once the lens was mounted, the focussing barrel was really stiff.

I´m trying to find out the relation between one thing and another, but I can´t. In one hand, if the ring were not not totally plane, I understand that to mount the lens could be a little bit harder, but in the othre hand, focussing shouldn´t be affected by that.

I´m getting crazy. this camera was in more or less good condition (the best russian sample I´ve seen so far), and it cost me about 150$. Now the range finder is not reliable (naturally, since I´ve screwed up the lens working distance), and to mount a lens and focuss with it looks like that I´m destroying it.

BTW, a nice black Jupiter-12 is on the way... :S

So if anybody has any kind of advise or can help me... I´d love to receive some tips!

 

[pschauss]

If you attached the mount ring without the shims you may be distorting it slightly. Try loosening the mounting screws and see if the lens will screw in freely.

 

[farlymac]

Possibly a mis-alignment with the rangefinder cam, causing a bit of jamming when trying to focus?

PF

 

[pordiosero]

Hi;

I loosen a bit the screws on the mount and it became slightly better, though still not smooth. The lens itself was never as smooth as it could be a new one. But this still scares me... my only working russian camera!

pschauss, I agree with you; I have disadjusted it for sure. But, how come this affects the focussing barrel, which is internal and it´s nothing to do with the mount?

farlymac, that sounds interesting, I didn´t think on that and it could be one reason... I´ll check it out.

I´m thinking on preparing some shims by myself, but I´m not sure whether this and its adjustment is doable. I mean, how important is the lens working distance? how it impacts a difference of 0,5 mm? and of 1mm?

Today I wanted to brong another camera I received these days (Kiev 4am) to get it adjusted. They guy seems to be skilled on Contac and Leica, but I´m not sure if Leica used these stupid shims, and since my Chinese is valid only for asking for noodles and similar, and his english is more based on smiling than speaking, this is gonna be funny....

Thanks for the suggestions. Any other opinion on this?

 

[wolves3012]

The lens mounts on these cameras are made of quite soft aluminium. When you replace them, it's important to tighten them up properly, otherwise you can easily distort them out of shape and then the lens can be difficult to screw on and the focus can be tight because of the stress on the threads. Yes, this *does* happen!

To put the mount back on correctly, put all 4 screws in and tighten them just lightly. Next, in at least 2 stages, tighten them up using an X-pattern (top left, bottom right, top right, bottom left, for example). Don't do them very tight either, they don't need it.

As for the shims, yes, they are important. An error of 0.5mm would cause a very bad focus error. The correct figure is quoted to be 28.80+/- 0.02mm between lens flange and film plane.

 

[pordiosero]

Well, here come some news. While the focussing remains stiff, now the telemeter is somehow more accurate. How good it´s now taken pictures is something that I can´t say, but I´ll test it.

Regarding the focussing ring stiffness, perhaps it always was stiff, may be a little bit less. I have decided to open it and replace the russian grease with some modern lube. Indeed, I´ve been trying to open the dammed lens, by trying to turn the front group CCW, but nooooo way. Hard as rock. Any thought on this?

I´m not sure if it´s a good idea to play so much with a kind of expensive russian camera which performs (performed) ok, but I wanted to re-skin it, lube the left film cylinder, and I´m thinking also on replacing those crappy shims with some plastic...

Wolves, thanks for your tips. Normally that´s the way I use to screw whatever. What seems to me strange it´s the fact that a problem when coupling the lens to the camera may affect the foccusing ring. Now I don´t know if i´m getting crazy with this or what, but focussing it not attached from the camera looks pretty much the same stiff than attached. Perhaps the slight descent of temperature?

 

[rxmd]

The most important tip I can give you is that you might want to read this.

 

[wolves3012]

Well, here come some news. While the focussing remains stiff, now the telemeter is somehow more accurate. How good it´s now taken pictures is something that I can´t say, but I´ll test it.

Regarding the focussing ring stiffness, perhaps it always was stiff, may be a little bit less. I have decided to open it and replace the russian grease with some modern lube. Indeed, I´ve been trying to open the dammed lens, by trying to turn the front group CCW, but nooooo way. Hard as rock. Any thought on this?

I´m not sure if it´s a good idea to play so much with a kind of expensive russian camera which performs (performed) ok, but I wanted to re-skin it, lube the left film cylinder, and I´m thinking also on replacing those crappy shims with some plastic...

Wolves, thanks for your tips. Normally that´s the way I use to screw whatever. What seems to me strange it´s the fact that a problem when coupling the lens to the camera may affect the foccusing ring. Now I don´t know if i´m getting crazy with this or what, but focussing it not attached from the camera looks pretty much the same stiff than attached. Perhaps the slight descent of temperature?

Kim Coxon's pages will show you how to dismantle and re-grease the lens, if it's the standard Jupiter 8:
http://pentax-manuals.com/repairs/j8service.pdf
Yes, the front can be *very* tight to unscrew. Make sure you follow the correct sequence for your lens, there are several different types.

 

[pordiosero]

Kim Coxon's pages will show you how to dismantle and re-grease the lens, if it's the standard Jupiter 8:
http://pentax-manuals.com/repairs/j8service.pdf
Yes, the front can be *very* tight to unscrew. Make sure you follow the correct sequence for your lens, there are several different types.

haha, I do know that page!! 😀 the problem is that I need Hulk Hogan or somebody of the kind for getting it out. A few hours have passed by, and still feel pain on my fingers! May be the previous owner cemented it...

I´m starting to think on gettin´ another J8. But I´ve already spent too much month in russian antiques 🙂

 

[pordiosero]

The most important tip I can give you is that you might want to read this.

Uops, I didn´t read you before. I also know that book, indeed sometimes I read it on the way to the office. Of course I find it usefull, but my english sometimes is not that good and the pictures he refers on the text rather are on the same page or even near... so I get crazy 😀

However, thanks for the tip!

 

[fanshaw]

If you just want to relieve the focussing stiffness this can be done by removing the outer ring at the rear of the lens mount. This is held on by three screws. Another part lifts off to reveal some of the focussing screw threads. You can remove most of the existing grease and replace it.

 

[pordiosero]

Hi fanshaw, that option sounds cool. Only one question: is it the ring just on the back of the lens wrapping the mount or perhaps you mean the ring with the distance scale?

Thanks.

 

[fanshaw]

I meant the ring on the back with the three screws, but you could also remove the distance scale to lubricate the threads as well. I am assuming your J8 is contemporary with your Zorki-3M-the later lenses have different mounts.

 

[pordiosero]

Thank you so much fanshaw. I couldn´t open the ring you told me, but I unmounted the distance scale and bingo, now the lens goes really nice (well still it isn´t perfect, but...). The problem is that something seems to touch/scratch inside... so yes, it´s better, but still some problems.

BTW, these tiny small scrrews are horrible. I can´t understand why these people used aluminium instead of something less prone to loose the shape. Oh, yes, of course, because of production costs 😀

I don´t regret at off of having opened the lens. I have used a really funny (chinese?) lubricant: "Hammer & Hammerdrill Grease", and it goes much more better. Now I hope that with a bit of time, it will become even better 😀

I have also tried to improve something. I noticed some marks on two rolls I´ve shot. This could be due to: dirtiness, defects on the surfaces where the film makes contact, and some stiffness on the cylinder where the roll is mounted. Well, I have lubed it after getting it out of the camera, and now the feeling it´s a little bit better, but still I find it stiff in some angle when spining it.

 

[pordiosero]

UPDATE: I´ve loosen a bit more the screws on the mount, and it goes fine. One problem: I´m pretty sure that thie ring is NOT as tighten than before...