Incompatible Industar-50?

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POSTI-Tuomo

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Hi again.

Bought today this '74 Zorki 4K for parts from a flea market, absolutely nothing works and I tinkered with it a good three hours. And the initial price was 40 euros! 😱 Got it for five when I explained what was (or rather, what was not) wrong with the piece...

Did get an opportunity to delve further into the mechanisms without the fear of breaking something that actually could work 😉 So the body and its inner works are waiting for the bad day, to be salvaged for parts.

But what is odd, is that the only good part, the lens won't mount on my Zorki 4 of 1967 vintage. The Industar-50 that came with my 4 is a white one, from the year '65 and the black one from the 4K is ten years younger. I thought they both were of the Leica Screw Mount standard...

I cannot fit the later Ind to the Z4, it stops about half-way in. At that point, very stiff resistance is felt and I didn't dare to attempt to screw it in any further fearing it would ruin the good Zorki. I also examined the threads and compared the two lenses and they looked the same. So what could be wrong with the '75 Ind?

The reason I want to use the black Ind is its aesthetics ( ! ) and smoother operation... Please bring some insight on the matter at hand! 😱
 
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Hi Posti,
Try taking the back off the Z4 and watch from the back as you try to mount the lens. Make sure the lens is set to infinity first. If the RF arm is very slightly out of line, it can work with some lenses but jam on others.

Kim
 
Thanks for the reply, Kim.

But what is the rationale behind setting the lens to infinity prior to test-mounting the lens onto the camera? I thought that was a no-no? And whilst mounting the lens this way, what should I be looking for when it comes to examining the RF sensor arm? Any tell-tale signs of an inappropriate RF arm alignment?
 
An update: It seems the Zorki 4 RF arm is in a more upwards position compared to the broken 4Ks arm. But not by much, 0.5 mm at most.

My white Ind-50 would mount on the 4K... so that RF arm likely is the culprit? How to fix?
 
Sorry, mistype. Set to close focus so the RF ring is retracted. Looking from the back you will see if the RF arm is riding on the ring as you mount. Sometimes, if the arm has been bent up slightly, it will miss the ring and get jammed between the ring and body.

Kim
 
Hmm, no, it didn't jam between those two parts. The RF arm is just ever so slightly higher on the 4 than the 4K, but not to the extent it would jam between the body and the ring...

Maybe there's something wrong with the black lens's threads after all. Ought to check that again.

Although, the lens mount seems a bit different on the 4K...somehow flatter?
 
It could be the mount ring has been unevenly mounted on the 4. If the threads on the black lens are newer, there could be less play causing it to bind.

Kim

POSTI-Tuomo said:
Hmm, no, it didn't jam between those two parts. The RF arm is just ever so slightly higher on the 4 than the 4K, but not to the extent it would jam between the body and the ring...

Maybe there's something wrong with the black lens's threads after all. Ought to check that again.

Although, the lens mount seems a bit different on the 4K...somehow flatter?
Click to expand...
 
Uneven torquing of the lens flange screws can result in a slight warpage which in turn will cause a lens to bind part-way in. To test this theory out, loosen the four flange screws about one turn each. Then try to mount the toublesome lens. If it goes in smoothly, the flange was uneven.

If that happens, re-torque the four screws by tightening them in a "X" pattern. First tighten one and then toghten the opposite etc. Don't make them too tight!

-Paul
 
I have to agree with pshinkaw. The lens flange is very thin and too much torque to the screws can bend it. I tested this issue on my Zorki 1. But there is more: deformed flange could lead to a deformation of the focus helicoid of the collapsible Industars, make it very stiff. I had this kind of problem after reshimming the flange of the Zorki. Lens can mount on the body, but the focus, normally light and smooth, become very hard when i fixed the lens tightly. The issue was caused by a bad idea: to use little bits of calibrated metal instead of the shimming paper. I removed the metal bits, put the standard paper and the problem was over.
😉
 
Glauke said:
I have to agree with pshinkaw. The lens flange is very thin and too much torque to the screws can bend it. I tested this issue on my Zorki 1. But there is more: deformed flange could lead to a deformation of the focus helicoid of the collapsible Industars, make it very stiff. I had this kind of problem after reshimming the flange of the Zorki. Lens can mount on the body, but the focus, normally light and smooth, become very hard when i fixed the lens tightly. The issue was caused by a bad idea: to use little bits of calibrated metal instead of the shimming paper. I removed the metal bits, put the standard paper and the problem was over.
😉
Click to expand...
I've had a similar issue on my Zorki 1. When removed, the lens focus was easy and smooth. When fitted it became rough and tight in certain places. Re-torquing the lens mount cured it, thankfully!
 
I made the suggested adjustments to the lens flange screws, but that did not cure it...
I also cleaned the threads on both bodies and lenses. Now I'm stumped, I'm afraid. 😕 Any other suggestions? I tried every possible combo: all my lenses on the Zorki 4 (Ind-50 white, I-22 collapsible, Jupiter 8 white and the Ind-50 black). All but the black Industar would mount.

Results for the Zorki 4K: all lenses would mount, although the I-22 focusing was a bit stiff towards infinity...

This is a hard nut to crack, wouldn't you say? :bang:
 
In that case, I suggest obtaining a high magnification loupe or field microscope and examing the threads on the black Industar. You may have a cross-threaded mount or some other damage to the thread.

-Paul
 
Got an 8x loupe right here, let's examine the threads...

Ok, here's what I saw. I inspected all four lenses and their respective threads with a loupe for comparison. All lenses except the black Indy had smooth threads. That black one had somewhat rough threads towards the lens body, away from the mount. The very last bit was like a serrated knife, really. So this indicates the black Indy has borked threads, and therefore the Zorki 4K would accept every lens as its threads were distorted a bit as well. That means the lens mount on my Zorki 4 is in better shape, accepting only lenses with proper threads.

I think this one is busted. 😎

So whaddya think? Should I file the end of the thread smooth or swap mounts between cameras?
 
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If the Z4 is in good shape, I would leave it alone. You have another lens albeit in different colour.

Kim

POSTI-Tuomo said:
Got an 8x loupe right here, let's examine the threads...

Ok, here's what I saw. I inspected all four lenses and their respective threads with a loupe for comparison. All lenses except the black Indy had smooth threads. That black one had somewhat rough threads towards the lens body, away from the mount. The very last bit was like a serrated knife, really. So this indicates the black Indy has borked threads, and therefore the Zorki 4K would accept every lens as its threads were distorted a bit as well. That means the lens mount on my Zorki 4 is in better shape, accepting only lenses with proper threads.

I think this one is busted. 😎

So whaddya think? Should I file the end of the thread smooth or swap mounts between cameras?
Click to expand...
 
True that, Kim. That leaves me with the option of trimming that Indy noir, a cheap lens anyway, so not a great loss if it won't take the treatment well. I would reconsider if it was a Leitz though 😉. Now, where are my precision files... Bought them to trim my tweezers, but they'll do fine at this job too, I think.

EDIT: Trimming the threads didn't yield results, the have to be vertically distorted all the way through. That is all I can think of, really. I attempted to mount the Industar on my Zorki 1 too, and it refused to mount very early, about 1/4 turns in. All other lenses fit well.

I think we'll have to chalk this one up to warped threads...
 
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Keep the bad lens for parts. You may come upon another one that has bad glass but a good mount.

-Paul
 
From your description it sounds like the thread has stretched out of pitch which is why filing the damaged threads hasn't helped , Now if this was a job at work a few smart taps with a plastic mallet whilst screwing the lens into the mount would get things moving , but I think chalking it down to experience is the better option 😀

In the mean time here's a link to Tom Tigers I-50 relube page .



Paul
 
Nice, Paul. Been going crazy trying to find a site which describes I-50 disassembly. Much appreciated. 🙂

EDIT: That guide, ableit helpful, doesn't tell how to get access to the aperture setting ring's threads. That's causing troubles, really. Setting the aperture is not all that smooth... Do you have to remove some tiny screws at both sides of the aperture ring? Or are those just holes? Can't distinguish any details in them...
 
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