Voigtlander Nokton 40mm Helicoid issue

[Plochmann]

Hey guys, need some experienced advice from those who have tried to repair this lens, or similar builds. ***and please, no posts saying you shouldn't have tried to do this or that or worked on your own stuff or only professional bla bla should do this or that... sigh. We have one life, enjoy it doing what you want to do and try to learn as much as you can. I hate when people answer questions with negative statements that equate =stay stupid and spend your money. And yes, I get those responses all the freakin' time. **
I bought the lens used, for a good price from a market, and it worked okay except that the focus tended to jump in one spot, it would move smoothly then hiccup past one part and smooth out again. Thought no big deal, maybe dirty helicoid. Well, after about a month of causal use, the lens became looser and looser, rattling and shifting until finally the thing was apart in the bottom of my lens bag after a shoot. The screws were all in place, but a shim near the back element group had become unscrewed somehow, and the lens came apart from the middle. I got it back together, after some trial and error. I even talked to Voigtlander in Japan, and they offered no services on this lens at all for customers i.e. only would talk to licensed repair ppl. I'm in China, the repair ppl here were unfamiliar with this lens and Voigtlander Shanghai didn't give a response, I assume they don't know English and my Chinese isn't at a level to discuss these things.
Back to lens: To amend the focus issue, I cleaned up the helicoid a bit with a Q-tip, and it seemed to focus better and work great, for some time. After a year, the focus became damn tough, almost impossible at times to move. I had been using the lens a lot with a heavy attachment to the front for a specific shoot. I think this extra weight, applied via the front ring threads, caused this problem. It also messed up another lens, and I've learned that lenses are sensitive and have since bought a lens support system.
I take apart lenses for hobby, re-grease them and clean them. You can get some amazing deals on old stuff that is easy enough to repair. I've done a total of 10 lenses so far with no issues until now. This lens is tougher to work with for 2 reasons: 1) I don't usually separate helicoids, I just grease them a bit and move on, 2)I haven't worked on such compact, and simple systems like this Voigtlander before. I feel the whole lens aligns and relies on each part to focus, so it's very difficult to get together and still achieve accurate focus. Other lenses seem compartmentalized in comparison.
The 2nd time I took it apart, I took everything apart, cleaned and greased it best I could. I had to take apart the helicoid this time, because that was the issue. I used a white lithium grease as dampening, which is a different color from the black grease originally used, but I couldn't find out what Voigtlander was using or suggests to use. I put it back together, and the focus was very smooth, but everything was now out of focus. I'm sure I aligned the helicoid wrong, and woe is I because I have no manual or markers to go by.
I took it apart again, figured out how to align it by reverse engineering the thread placement, but this time I can't get the helicoid to screw together at all. It's like it was before, locked up. The thing is tight, unmovable and stuck. I removed the white lithium grease I was using but the things still won't fit together. I fear all the tinkering, damage from the attachment used previously, or original issues with the focus on the lens have left me with a bad lens. Damn shame.
From experienced guys like you, is there a trick to the helicoids and aligning them on these compact lenses? Am I doing it wrong? Does it sound like my threads are shot in this len's helicoid? Can I buy a new helicoid and just swap the back of the lens out and keep the optics, which are all in great condition? I know I could send this off to Voigtlander for repair, which would cost as much as a new lens pretty much. So, I'd like to DIY it, and as I said before... I want to learn.

Thanks for any advice or help, would love to hear from like minded people.

 

[Sarcophilus Harrisii]

Well we all have to start somewhere, those of us who work on our own stuff have all made mistakes.

Welcome to Rangefinder Forum, I note this is your first post here. This site is one of the better ones on the web for help with regard to camera repair topics, the fact that Stephen took on the hosting of the old archives of the former Classic Camera Repair Forum when they were almost lost for good only adds to the amount of information accessible from this domain.

May I note that as a new member, longstanding members (I suppose this includes me) will naturally want to try to help. I'm not sure, however that having just joined and requested assistance, you're in a position to be quite so dictatorial about the manner in which you'd like to receive it...

Having said that: I'd like to assist you, although I have not worked on the lens in question before, I have worked on rather more than ten.

First things first. Using a suitable lubricant is always a good move if you can obtain it. Here's a link to a grease specially formulated for optical applications. I have no connection to the seller at all other than as a buyer of the product. But optical lubricants are a very specialised niche of lubricant technology generally formulated for, and sold to, manufacturers or repairers in commensurate volumes. They're usually expensive to procure in sub-industrial quantities. This stuff is ideal for lens use and is actually very reasonably priced, hence, I have no hesitation recommending it, (though this doesn't necessarily mean it's the perfect grease for any lens from any period). It is however a better place to start than, say, automotive products, in most instances.

It's very difficult to offer observations about definite causes of the problem you've got without inspecting the item personally, so, I can only suggest a couple of possibilities. Perhaps the threads have been badly galled by (A) the stress of whatever it was you had attached to the front of the lens or (B) by being used without sufficient lubrication, or (C) by the wrong lubrication (you mentioned using a white lithium grease?). Alternatively, perhaps the starts of the threads have been burred enough to jam them when you've started them? Helicals can vary quite a lot in the pitch, depth and width of their threads, depending on points such as focal length and focus range to name just a couple of variables. Some are very tolerant of repeated assembly and disassembly (suffice to say you are not the only one to put a lens together with the thread starts wrong!). Others are much less so, and can be very finicky about the condition and, especially, cleanliness of the threads and particularly their starts. Which leads to the last point. Perhaps some foreign matter has jammed the threads, preventing them from rotating? You'll need to ensure the threads are absolutely spotless and that a suitable grease is in fact being employed, before considering other possibilities, naturally.

Stephen, the site owner, has sold and serviced Voigtlander lenses for some years so he or another member might have some more specific observations to make possibly.

That's a few things to ponder, feel free to add to what you've mentioned, other members may be able to think of some other points possibly.
Cheers,
Brett

 

[rscheffler]

I thought I recently read a DIY repair thread for this lens here... or somewhere... or at least a thread in which this lens was discussed.

I have this lens and it squeaks when the focusing ring is turned. Therefore I was wondering what would be involved in re-lubing it. Unfortunately I don't seem to have saved the URL. In other words, I believe this has already been discussed and possibly illustrated...

Maybe it was this thread, but I don't think it will help you much...

 

[Ronald M]

You are down to trial and error in reassembling the helicoid. More it one thread at a time and reassemble.

Pros make a witness mark when they take apart a focus helicoid so it goes back together the same.

Next you need to tighten the focus mount in a star pattern like car lug nuts. At the car factory, they use a machine to tighten all the nuts at one time to proper torque so as not to warp anything. Monkey mechanics do one at a time to full torque and then you get pulsating brakes. This does not happen with a new car until the mechanics get their paws on it . Then the trouble starts. Their cure is to grind the warp out of rotors and soon the the rotors are too thin and require replacement
My cure is to do the star pattern to around 40 ft pounds, repeat to 60, repeat to 75, repeat to final torque. I do not warp rotors ever . More work , but best way.

Do the same thing with your lens bayonet. Follow the star pattern and keep going around.
IT TAKES FAR LESS DIFFERENTIAL TIGHTENING TO BIND UP THE FOCUS THAN YOU CAN IMAGINE..

All my CV lenses required home repair and I will no longer purchase them. I have had the same focus binding develop with almost new ones.

Start your repairs without removing the bayonet, just loosen and retorque slowly.

 

[Plochmann]

Hey Brett, thanks for the great reply. I'm sorry about my draconian manner, I have actually been a member of this site for a number of years, but have gone inactive since moving abroad and the site seems to keep no record of me, except my log in name; not sure why. I'm a regular and a number and variety of forums, and it always irks me so much when people give poor responses, from the number of quality of posts following my question, I can tell this is not one of those forums and I apologize for being uncouth.

The link you provided is the exact lubricant I am using, I bought a few bottles last I was stateside and it worked well enough on other lenses. The Voigtlander however had black grease originally, so there is a difference for sure.

However, I think something much worse is wrong and possibly your A and B scenario is the culprit for sure. I've cleaned the helicoid well and gone over it with a magnifying glass, all appears good but the thing goes in rough, runs smooth, the jams up at a point with no sign of loosing up. I practically have to hammer it out it gets so tight, so I'm sure it's shot.
I'm going to Hong Kong to find parts I guess, you've helped confirm a lot of my concerns, thank your time.

 

[Plochmann]

@Ronald
I've figured out the correct alignment of the helicoid, since it's such a short helicoid it's not hard to trial and error, but the thing binds up yet.
I also work on cars, and thanks for the analogy, it totally makes sense to me now and I think you jus blew my mind a bit. I should have thought of that before, but that's why I'm just a novice at this, I go in a bit clumsy and don't think enough about the mechanics of it like a true tinkerer would.
My other CV lenses have given no issues, just this pancake one and I think I realize now that I've done everything possible to make it worse. I guess I need to start a forum topic about how to tell my wife I broke my lens and it will cost money to fix... hopefully there is already a topic on this.
Thank you so much for the help.

 

[Sarcophilus Harrisii]

Hey Brett, thanks for the great reply. I'm sorry about my draconian manner, I have actually been a member of this site for a number of years, but have gone inactive since moving abroad and the site seems to keep no record of me, except my log in name; not sure why. I'm a regular and a number and variety of forums, and it always irks me so much when people give poor responses, from the number of quality of posts following my question, I can tell this is not one of those forums and I apologize for being uncouth.

The link you provided is the exact lubricant I am using, I bought a few bottles last I was stateside and it worked well enough on other lenses. The Voigtlander however had black grease originally, so there is a difference for sure.

However, I think something much worse is wrong and possibly your A and B scenario is the culprit for sure. I've cleaned the helicoid well and gone over it with a magnifying glass, all appears good but the thing goes in rough, runs smooth, the jams up at a point with no sign of loosing up. I practically have to hammer it out it gets so tight, so I'm sure it's shot.
I'm going to Hong Kong to find parts I guess, you've helped confirm a lot of my concerns, thank your time.

Hi,
rather than welcome to RFF then, perhaps I should say, welcome back. 🙂

No apology necessary at all, just trying to smooth the way for you a little. FWIW I do appreciate your sentiments. Yes, it's possible to break just about anything if you try hard enough, but, some of us prefer to learn how things work and how to fix them and have been quite successful at it. Last time I checked it wasn't actually against the law to work on your own photographic equipment either. 😉 The catch I think is to be aware of one's limitations and take things a step at a time.

Anyway. Back to your helicoid issue. It's an interesting one technically to try to nut out from afar. You may be right, of course—the only solution might be a replacement part. But at the moment it sounds like you don't have a great deal to lose by seeing what you can do to persuade the old one to work again, even if it results in a total loss to the part(s).

I read and re-read your original post to try to get a better understanding of what the lens is doing at the moment. As I understand it, basically, it originally became loose, you sorted it, then it became tight, and after some dismantling and re-assembly it's now basically locked up, yes? Hmm. One point I'm not quite clear on is whether the threads are refusing to start much, if any, or if it's behaving like it was some time ago—threading together for a ways, and then locking up? If it's the latter, does the resistance grow progressively, or is it reasonably smooth until it jams?

I'm at a double disadvantage since not only can I not see the lens involved, I've never seen one let alone worked on it. Still, I've got a few thoughts that you could ponder, perhaps, and maybe pursue or reject out of hand (because you know more about the parts, than I do!).

There are a few things you might consider trying. I wouldn't necessarily suggest all of them, when dealing with parts in good repair but from the sound of it, the helicoids will be scrap at this stage, anyway. If they won't begin to thread at all, you could consider gently dressing the their starts, to clean them up. If they are starting and threading OK until they lock, then, I would take a depth measurement of the parts, and re-examine the threads around that depth particularly closely, on the off chance you may have missed something when you first used the magnifier?

If you can start the threads OK and it subsequently jams, and you can't see an obvious cause, if we can discount the presence of sand, dirt, metal debris etc (and you've cleaned them well, yes?) then there might be three possible problems that I can think of.

1. The thread surfaces are damaged enough to hinder smooth actuation (either on their surface, or profile (bearing in mind the use of the heavy attachment you mentioned). It seems unlikely, as you've examined them, but nevertheless. Is the profile and thickness of the threads consistent at all points? Have they been flattened out at their outside edges because of the weight bearing on them? If so, you just *might* be able to shape them back to usable condition, if they're binding.
2. There is excessive thread clearance as a result of wear. Which possibly leads to...
3. There is a problem with the lubricant used on the threads.

Without being able to examine the parts, I'm leaning just a little towards the third possibility. Because (A) you've suggested the original lubricant was a different type, and (B) your current problem has arisen since you changed it (along with a few other points such as stripping it etc, but, still). The grease you've used (and which I suggested) is certainly good stuff, I've used it in a number of lenses myself with excellent results. But it does feel fairly light. This may not always be a good thing, and not just because of the change in "feel" you may get at the focus ring. Some helicals will need a reasonably heavy grease, because as well as lubricating the threads it's important in not just imparting a desirable feel at the focus ring, but also in maintaining the correct clearances between the parts and in possessing sufficient load carrying ability (particularly in the case of longer, heavier, lenses) to prevent metal to metal contact.

I can give you a case study to hopefully help explain what I mean. I'm quite a fan of the various lens shutter 35mm SLRs that were made from the 1950s through 1960s, notably the Zeiss Contaflexes, which were certainly some of the better ones. After the first two types they went to a unitary focus arrangement that moves the shutter with the optics. They could also take interchangeable front components, and the 115mm and Monocular are reasonably heavy. Having worked on more than a few of all types, one fairly common issue the unit focus types may have is to manifest some excessive play or even a wobble in the lens/shutter array. They were very well made cameras (better, actually, than most people realise for what were, whilst not inexpensive, still SLRs that weren't targeted at professional users). They do wear a little here and there, but not much, and not out of normal adjustment limits usually. So the lenses don't wobble because the threads wear. It's actually very simple. The original grease Zeiss used in them sixty-odd years ago has often dried out, and when this happens the threads just have too much clearance. Strip them down, clean them, and put fresh grease back in them, and they are as smooth and tight as new. Without a trace of play, either.

I hope this has helped to illustrate that the quantity and type of grease used may, potentially, be crucial to correct operation. It may be, perhaps, that the type you've used isn't very compatible with your lens? At face value it appears possible, as the colour of the original (black) was completely different. The presence of moly, perhaps? This would suggest the need for high load carrying ability.

In your shoes, at this point I think I'd separate the parts (using cold and heat gently, if necessary, to change the clearances until the parts may be persuaded to separate. You could Eg. employ ice in the inner, a hair dryer on the outer, (use a plastic bag for the ice, of course to prevent water damage). If, after scrupulously re-examining the threads and their starts for signs of wear or damage you can't find any significant flaws, I'd thoroughly clean the threads in solvent, try a heavier weight grease, I reckon, and give it another shot.

I'd not be surprised if you can't procure a specialist optical grease easily, given the language issues and location you may be at. So by all means, use some automotive products if you have to. Yes, they may outgas eventually. Well, you're not selling the lens any time soon, right? And, if it comes to that, you can clean the optics or apertures in a couple of years if push comes to shove. You've already proven that you can do that sort of thing. In the meantime, it just *might* get your lens working again. And if it does, then you've also learned a bit in the process, and that has value also, right?

Keep me posted anyway and sorry for the long post but hope it helps.
Cheers,
Brett

 

[Plochmann]

Wow

Wow

Thanks Brett,
Thank you, this reading gave me brain freeze and I had to come back to it after a week. I agree with your mentality, hey, if it's doesn't work it's broke, so just try and fix it. So I will try everything you've suggested and more, but not any time soon. I just got into a big full time job, don't think I can bring it to the office and curse all day at it. I'll keep you posted on how things go when they do go. Thank you again.

 

[znapper]

Hello, I did a clean and lube on mine, there is a trick to ease the trouble getting the helicoid back again (the Nokton can be stubborn).

First, check the threads on each part to see if it is damaged, I had another lens that was and I had to poke with a tiny screwdriver to clear metal and open up the threads for it to enter properly. (Last resort!)

Take a look at my write-up here, the last image shows how I got my helicoid to enter, after 3 hours of pain: http://helino-photo.blogspot.no/2016/08/how-to-fix-squeeky-voigtlander-nokton.html

Hope you get it fixed ^^

 

[Plochmann]

Thanks for responding more. I've been traveling on business for a while now and haven't sat down and tried to repair it. Talking to you guys and other handy type people, I think the Helicoid threads are twisted. They look okay to the naked eye, but upon inspecting there is enough damage to cause issue. I will try my best to fix the threads and get it back together when I'm back in town. Thank you for the advice I'll update you when things are working...or not working...