PeterW
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Post by PeterW on May 17, 2008 6:03:29 GMT -5
Oh, Bob! That sounds like an idea born of desperation (or exasperation).
IMHO trying to lever the ring out is a good way to ruin the lens. The ring won't 'pop out', believe me. Soft aluminium has little or no 'spring'. It just bends.
You might possibly manage to lever it out, but with a 99.9% chance of distorting both the ring and the lens barrel. The threads are very fine pitch, and I doubt if you'd ever get it together again.
If the ring was made to unscrew, the only chance of getting it out and getting it back again is to unscrew it.
A possible alternative to lighter fluid is acetone ( nail varnish remover, but not the 'oily' sort). If that doesn't help to free things I would go with the idea suggested by Peter S, to drill two opposing small holes in the ring and then use a lens wrench.
If you can't get a 1mm drill bit most decent tool or hardware stores keep 1/16 in (1.59 mm) drill bits. You don't need a big power or hand drill with a bit this small. Drilling by hand with the bit held in pin vice (vise?) is slow, but not too tedious in soft aluminium. Drill the holes deep enough to allow the wrench to get a good purchase.
You'll need a guide indentation, but I don't think a needle point will give you a big enough guide to stop the drill bit wandering on a sloping surface. In aluminium, and sometimes in soft brass, I use a pointed awl to make the guide indentation. A pointed punch and a hammer are too brutal for this sort of work.
Good luck.
PeterW
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Post by vintageslrs on May 17, 2008 7:58:02 GMT -5
Oh, Bob! That sounds like an idea born of desperation (or exasperation). ---------------------------------------------------------------------------------- that it is.....I am exasperated for sure.... But thanks Mickey and Peter W. for the latest suggestions..... I'm letting it sit for a bit and may try more later today or tonite.... Bob
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Post by Peter S. on May 17, 2008 16:36:21 GMT -5
Bob, all these posts should make it clear: we all suffer with You! I second the idea of using acetone. Carefully. In the end acetone for sure is less pecarious than WD40. I thought even the word "WD40" was banned here... But what I would like to say is this: when You start drilling it is of utmost importance to use a sharp drill. Myself I would most likely use a center drill. First do a small ding by a needle point. Then carefully use the center drill. Center drills are not to widely spread - too few of us are trained mechanics. en.wikipedia.org/wiki/Drill_bit#Center_drill_and_spotting_drillCaveat: use a center drill at relatively low speeds. If You prefer to use a classical drill then use one looking like the PCB through hole drills in the Wikipedia article. These small drills should be operated as fast as possible. But I'd try it with a small center drill (3..5mm outer diameter). Best regards Peter
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mickeyobe
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Post by mickeyobe on May 17, 2008 20:18:22 GMT -5
WD40! There. I said it.
WD40 is relatively benign whereas acetone can dissolve some plastics and some paints and enamels and some glues and some synthetic fabrics. And it doesn't smell that great.
Here is yet another ploy that might work. Put the lens in your freezer for an hour or so then give it a try. If the ring contracts more than the lens barrel your problem is solved.
Mickey
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PeterW
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Post by PeterW on May 17, 2008 20:31:55 GMT -5
Stephen,
In my second year as an engineering student back in 1945 (God, was it really 63 years ago!) I did a term's stint in an instrument toolroom where any job with limits greater than plus or minus a thousandth of a millimetre wasn't reckoned to be a real precision job.
But that's beside the point. On my first morning the head toolmaker, who was a caustic-tongued martinet, but a superb craftsman, made me repeat three times:
"My hands are the most valuable tools I'll ever have, so when I'm using a cutting tool of any sort I must keep my hands behind the cutting edge - the bugger can't cut backwards."
After that I spent a week learning the correct way to use a hand file and another week learning how to use a metal scraper to produce a flat surface. After that came weeks of how to use a micrometer and vernier caliper, how to use taps and dies, how to harden, temper and sharpen hand tools and lathe tools, how to do simple turning and milling, screwcutting and so on, and so on.
Every tool had to be cleaned and put back in its wooden box immediately after use, not left lying on the bench until clearing up time - and God help anyone foolish enough to leave even a small amount of swarf on a machine tool or, worse, commit the cardinal sin of laying a tool down on one of the very expensive surface plates.
In the last two weeks of the term I did actually get to make something, a one-inch cube of steel that had to be a sliding fit, whichever way you turned it, through a square hole cut in a quarter-inch thick steel plate.
I have to admit that my standards in using hand tools and small machine tools have dropped more than somewhat over the years spent in design offices, and even more years writing and taking photographs for a living, but I still remember a lot of the training even if I don't always apply it.
PeterW
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Post by Peter S. on May 29, 2008 4:29:25 GMT -5
Hi Bob,
what's the state of the issue? Is it resting in the shelf or has it wandered into the waste bin??
P
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Post by Randy on May 29, 2008 9:27:39 GMT -5
At any rate, being an automotive enthusiast, I'm familiar with WD40. Be aware, WD40 is known in automotive circles to attract moisture. If you use it, clean where you used it so moisture will not be attracted.
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Post by vintageslrs on May 29, 2008 18:37:49 GMT -5
Hi PeterS The status is that it is resting on the shelf I have not touched it in a week or so. We had company for the long holiday weekend here (US) and I have a couple of other projects going in other hobbies, including a little bit of bodywork on an old 4X4 SUV----so it has taken a rest on my shelf. But it will get back in my hands soon to frustrate me more . Randy---I thought one of the properties of WD-40 was that it displaced moisture? Bob
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PeterW
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Post by PeterW on May 29, 2008 19:03:11 GMT -5
Bob, I had a similar situation a couple of days ago with a Canon lens I wanted to open to get rid of some dust. No holes for a lens wrench, so I tried the rubber bung method, but my aged wrists just hadn't got enough strength to push hard enough and twist at the same time. And, as they say in the advert, I thought of you.
I was about to drill some wrench holes, but struck by a sudden flash of inspiration (he says) I put the rubber bung down on some smooth concrete (the back doorstep) where it would get a good grip, stood the lens on top and twisted with both hands while I used my weight (what little of it there is) to exert pressure.
Worked a treat!
I've also found that as they come from the store rubber bungs and door stops often have a light coating of releasing agent from the moulding process. This stops them getting a good frictional grip, but it comes off easily if you wipe it over with lighter fuel (naptha).
Worth a try?
PeterW
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Post by vintageslrs on May 29, 2008 22:11:09 GMT -5
Hi PeterW Your story inspired me.....I was about to type that I will certainly try your method tomorrow......then it hit me. Being a New Hampshire resident for only 3 years---one of the many differences here compared to New Jersey is that most of our (including mine) steps/porches are wood...in NJ--concrete. So, I have no steps/porch concrete to use......then I thought well, how about driveway--nope mine is loose stones--LOL....then I figured sidewalk--nope don't have a sidewalk---LOL. I just love rural New Hampshire living . so, I guess if I am gonna try your method---I will have to take my Rokkor lens on a FIELD TRIP---- ;D. Ahh---the saga continues..... Bob
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mickeyobe
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Post by mickeyobe on May 30, 2008 15:11:20 GMT -5
At any rate, being an automotive enthusiast, I'm familiar with WD40. Be aware, WD40 is known in automotive circles to attract moisture. If you use it, clean where you used it so moisture will not be attracted. Randy, Right from the horses mouth ................... Mickey
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Post by Peter S. on Jul 19, 2008 12:54:28 GMT -5
Well, what is now the state of the project?? I am pretty curious what to do in such a bad situation.
Best regards Peter
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mickeyobe
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Post by mickeyobe on Jul 19, 2008 15:02:38 GMT -5
Bob,
Just reviewing this thread when it occurred to me that PeterW's suggestion about using a concrete doorstep might work if the cast of characters were slightly altered.
If you have a drill press and you and can devise a way to hold the rubber bung in the chuck and put something like an old blanket or towel on the base to protect the camera with a couple of stops attached to the base to keep the camera from turning you will probably be able to exert enough pressure ( but don't overdo it ) while at the same time turning the chuck by hand or with a little leverage.
Perhaps.
Mickey
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mjkthelast
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Ex Aviation Eng & QA
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Post by mjkthelast on Sept 4, 2008 7:21:38 GMT -5
As an ex Aircraft Engineer, Avionics, having read all the suggestions, some look scary, if all else fails read the book. Now we have a problem who's book. I shall continue to read the comments, it's interesting, if not frustrating to the lens owner. I just hope that I do not get into the same situation. Maybe get a cheap lens on E bay and practice. Thus saving your good lens for the real thing, having worked out a proper way.
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Post by John Parry on Sept 5, 2008 17:29:37 GMT -5
mjkthelast
Something else that can be tried. I got a very nice Praktica bayonet fit Carl Zeiss Jena 24mm lens, on which the focus ring had seized completely. Now I knew from previous experience that taking lenses apart is the easiest thing in the world to accomplish. But I also knew from previous experience, that lifting that first watchmaker's screwdriver is the first step to gently kissing the lens goodbye.
So I tried a different strategy, and carefully placed the lens in a drawer, thus having saved myself all the trouble of the dismantling process, re-assembly, re-dismantling, re-reassembly, and throwing the lens in the sea.
Next time I opened the drawer, I mistook the lens for a very similar 24mm M42 lens, and lovingly fondled it, discovering as I did so that the focus ring ring was very stiff. "Oh no," I thought; "this must be a generic fault with this particular lens". But on closer examination, it turned out to be the bayonet fit. And although it was stiff, it was no longer seized completely. So that lens got exercised morning, noon and night. Now its completely functional once again.
Hope this helps...
Regards - John
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