Rough focusing 9cm 1:4 Elmar

pvdhaar

pvdhaar

Peter
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I recently got hold of a 9cm 1:4 Elmar with very neat glass, but its focus was 'rough', to say the least (completely hardened grease). I've managed to get it going with a very light application of wd-40, and it now turns freely from 1m to infinity again. Next step would be to apply some new grease to make it run smoother. Is there a way to do that without taking the focusing unit completely apart? (I can unscrew the optical unit from the helicoid part no problem there). And if so, what kind of grease would be advisable?

Thanks!
 
Try not using WD40 on lenses. It may result on on haze/fog on the lens, since it displace water. To remove gunk, ronsonol or alcohol may be better, although only appy a bit of it. Just my 2 cents.


Marcelo
 
Every lens I wanted to take apart and reassemble - google search, first.
But I can't recall I ever find via google search how to do it on such common lens from Leitz.

Also many lenses are too much hustle on focus helicoids.I'm using cheap watches lube from ebay. I get focus helicoids exposed (usually at minimal focus distance), applying watch lube and working helicoids in and out. Sometimes it solves the issue completely and for years . With lens block taken apart and focus block partially disassembled. But no idea how to get to it with this lens.
 
Beemermark said:
Just about the worse for 90% of what people use it for. Not for fishing gear, firearms, watches, precision mechanical components, etc, etc.
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On a hifi website I'm a member of, there's a lot of people saying that it's OK to use WD-40 on "scratchy" potentiometers, as opposed to an electronic contact cleaner or De-Oxit fader lube or similar. I'm still not quite comfortable with that...
 
I have a friend who is a retired camera repair tech; he began repairing cameras the year I was born, 1975. He runs a group on Facebook called Learn Camera Repair. The [NODE="1"]Home[/NODE] rule in the group is "NEVER, ever, EVER tell someone to use WD-40 for ANYTHING when repairing photo equipment." He and the other professional technicians he has gotten to help with the group all say that WD-40 is the fastest way to destroy a camera or lens.

The only way to fix a lens with bad helicoid lubricant is to completely disassemble the lens, remove the dried grease, apply new grease, and reassemble.
 
BillBingham2 said:
How do you know how much is too much?

B2 (;-?
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Bill, you are best to apply a light coating evenly across all of the threads, as opposed to large smears in just a few locations. Obviously, if one entirely fills threads to their roots, their opposite numbers inevitably must displace that, when the two are mated—resulting in the excess coming out the ends of the helical units. This can be unsightly, to say the least, and is undesirable given excess grease may find its way onto optics or aperture surfaces. (Also wasteful, as the correct lubricants are more expensive than Eg common automotive greases.) Not surprisingly, lighter grades tend to displace more readily than heavier types (which may also have a damping function). It is in the nature of threads to redistribute the lubricant to some extent, hence, usually some minor clean up will be needed even if an appropriate quantity of grease is used. I will always exercise helicals for several minutes, carefully wipe off any residue, then exercise some more before a last tidy up, if needed. If you did not use too much lube, further exercising of the threads should see no more grease appear. I suspect most people tend to apply too much grease the first few times. I suppose this must be better than not using enough—but only if all the excess is thoroughly cleaned. With practice, one soon learns to moderate how much is dispensed. Don't overlook alignment keyways; if present, these need a trace of grease for smooth focus action, too.
Cheers,
Brett
 
Thanks for the responses!

By the way, it's not like I doused it in wd-40, just the lightest bit in the thread to get it going. As said, the optical unit unscrews from the focusing unit, so they've been split while applying and no wd-40 got in touch with the glass. I'll have a look at watch oil.
 
pvdhaar said:
I recently got hold of a 9cm 1:4 Elmar with very neat glass, but its focus was 'rough', to say the least (completely hardened grease). I've managed to get it going with a very light application of wd-40, and it now turns freely from 1m to infinity again. Next step would be to apply some new grease to make it run smoother. Is there a way to do that without taking the focusing unit completely apart? (I can unscrew the optical unit from the helicoid part no problem there). And if so, what kind of grease would be advisable?

Thanks!
Click to expand...

I was thinking of a high-quality white lithium grease for the helicoid.

This has been suggested on other forums:
Helimax-XP Camera Telescope Optical Instrument Focusing Helicoid Grease w/PTFE 1oz 28g

71Q-6-YVzYL._SL1500_.jpg - Click image for larger versionName: 71Q-6-YVzYL._SL1500_.jpgViews: 0Size: 193.8 KBID: 4811040
 
raydm6 said:
I was thinking of a high-quality white lithium grease for the helicoid.

This has been suggested on other forums:
Helimax-XP Camera Telescope Optical Instrument Focusing Helicoid Grease w/PTFE 1oz 28g

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This is what I have been using for some years with good results. I do have a 9cm Elmar, however apart from removing a little haze from its optics have had no need to disassemble it further as it is in good repair. But I did strip my 5cm Summarit right down a while ago, and this is now working very well after cleaning the helicals thoroughly and lubricating with Helimax. I'm sure it would be fine in an Elmar.
 
Sarcophilus Harrisii said:
I suspect most people tend to apply too much grease the first few times. I suppose this must be better than not using enough—but only if all the excess is thoroughly cleaned.
Click to expand...

Time to make you cringe a bit...

The first lens I ever relubricated was a Soviet lens that had seized absolutely solid. I forget whether it was an Industar 26M or an Industar 61 L/D, but either way, you could barely turn the ring at all. Classic Soviet "beeswax" in the helical. Thankfully, they're ridiculously easy to take apart (three set screws and back all the way out, if I remember right), but cleaning all that gunk out? That took a long time. I was using surgical spirit and "q-tips" - not ideal, but got the job done.

Problem is that a dry fit after cleaning showed a LOT of play. Turns out this isn't uncommon. One theory I found online was that late Soviet production purposely cut the threads wider than needed; it was faster and easier to pack the threads out with thick grease than it was to cut things to fine tolerances.

So, with this in mind, I went down a local mechanic's yard with a film canister and asked if I could steal some automotive grease. Scooped a bunch up, came home, slathered the male thread in the helical until it was thoroughly coated, and put everything back together, cleaning off all the excess that gooped out the ends. The result was a smoothly focusing lens without all the wobble that was present when it was "dry", so maybe there's some truth in that old theory.

Now, I'd never do that with a 90mm Elmar - if only because automotive grease makes a finely-cut helicoid feel excessively heavy (don't ask how I know that). But that Industar? Still smooth and still wobble-free 12 years later. And, amazingly, that automotive grease doesn't appear to have caused any haze or damage to the optics, either.
 
there is an post on RFF about this issue:

https://www.rangefinderforum.com/node/172950

When servicing helicoids, you have to pay close attention to where they separate because of the multi-start threads. Take multiple measurements of length and scribe some alignment marks. Clean with solvent, toothpick, tooth brush, etc.. and repack with helicoid grease.
 
If you want to see how things like this are done professionally, you should watch a video or two on a camera overhaul and see how they clean the parts and then lubricate them on reassembly. The overhaul videos on YouTube from retinarescue.com, a lot of Kodak Retinas and other cameras, show how he cleans then lubes a focusing helicoid correctly.

-- search for Chris Sherlock Retina on YouTube.

WD-40 is perhaps the worst thing to use on these kinds of mechanical devices. The "WD" in the name means 'water displacement' .. it was invented as a means of displacing seawater on navy ships for things like hatch hinges and gun turrets .. it is hygroscopic, absorbs water, and leaves a thin film of lubricant intended to be washed again in a short time. On small devices with metals that can oxidize, it *promotes* rust and attracts grit ... You need to dismantle the components and completely eliminate it from the surface, then apply a tiny bit of the correct helicoid grease to lubricate and seal the threads from oxidation and corrosion.

G
 
Godfrey said:
IThe "WD" in the name means 'water displacement' .. it was invented as a means of displacing seawater on navy ships for things like hatch hinges and gun turrets .. it is hygroscopic, absorbs water, and leaves a thin film of lubricant intended to be washed again in a short time.
G
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In the past I used it on plain polished steel surfaces after a clean water wash thinking it would keep them from rusting. And it does keep them from rusting. BUT months later when I pull the pieces out the drawer the surfaces have a brownish gunk than is impossible to remove with anything less than Emory cloth. I also used it once on a steel removable bushing (~1/4" diameter) that rotated in a steel cylinder. Found out later that the only way to get the bushing out was by using a propane torch and hammer. I won't even buy the stuff. It was good in WWII time frame but there are way too many better products out their today. As others have said, for stuff like stiff lenses or sticky leaf shutters, lighter fluid is a good short term fix.
 
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