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Thread: Trouble releasing front element retaining ring of 178mm Kodak Ektar - images included

  1. #1

    Trouble releasing front element retaining ring of 178mm Kodak Ektar - images included

    Hi all,
    I am trying to clean up my recently acquired 178mm Kodak Ektar, and have been able to open up most parts of the barrel so far, but I am unable to release the front element retaining ring. It seems that the locking screw that holds the retaining ring in place is either damaged or has been removed on a past repair job and is now held in place by a glue or solvent.

    https://imgur.com/a/dnmOAEH

    It looks like there is a flathead screw head showing, but it does not grip a screwdriver at all. I have thought about using a friction wrench on it to see if I can prize the retaining ring loose by turning it, but I want to see if anyone can determine what the situation is here before I do something detrimental to my lens.

    Please help me figure this out.

    Many thanks.

  2. #2

    Join Date
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    Re: Trouble releasing front element retaining ring of 178mm Kodak Ektar - images incl

    I had a similar problem with a set screw that its head was completely destroyed. Normally I could use a Dremel to cut another slot in the head, but the screw was recessed. I very carefully and very slowly drilled the screw out, retapped the hole, and used an appropriate replacement screw. Trick was to clamp the metal lens part and use a MicroMark MicroLux® 3-Speed Mini Drill Press to accurately drill the hole. Another time I tried to use a hand held drill and with the screw being made of a harder metal, the hole was drilled skewed off center.

  3. #3

    Re: Trouble releasing front element retaining ring of 178mm Kodak Ektar - images incl

    Greg's advice is good. I have had to do exactly the same thing. Also, sometimes I have succeeded with a seized recessed screw by applying tiny drops of acetone from a toothpick at intervals of about an hour during the day to soften the glue used to hold the screw. Then I've made up a hardened steel chisel just the width of the screw, driven that in to create a slot and twisted the screw out. Let us know what you decide to do and how it turns out.

  4. #4
    Tin Can's Avatar
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    Re: Trouble releasing front element retaining ring of 178mm Kodak Ektar - images incl

    Good luck

    Not easy

    Are you sure you need to do it?

    When I had the impossible on $100K Diesel we used Metal Disintegrator Service

    Is the lens yellow?

    Treat with SunShine
    Tin Can

  5. #5
    Drew Bedo's Avatar
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    Re: Trouble releasing front element retaining ring of 178mm Kodak Ektar - images incl

    This may not help much, but I just have to tell it anyway.

    A long time ago, (early 1990s) I was able to salvage ten Oscilloscope cameras from obsolete medical scanners. My cost was a few dollars each. Each one had a 75mm f/1.9 lens in a shutter mounted inside. These lenses had a huge aluminum collar attached to the front and rear lens barrels. Lenses just like this are still available on e-Bay right now., with the collars attached. I tried everything I could think of to separate these collars from the lens element mounting barrels; solvents, hest, big strap wrench . . .nothing worked.

    A last0ditch approach: Took them to a gunsmith and assured him that if he tried to cut off a collar and ruined the lens that I wouldn't be mad at him. I unscrewed one front lens assembly and he chucked it up in his lathe. Cut it off without much trouble. So I had him do it to the others too.

    Now we can discuss just how usable or valuable these oscilloscope lenses or their shutters are, but that is not the point. I offer the story in case something similarly brute-force and heroic might be a solution.
    Drew Bedo
    www.quietlightphoto.com
    http://www.artsyhome.com/author/drew-bedo




    There are only three types of mounting flanges; too big, too small and wrong thread!

  6. #6

    Join Date
    Nov 2017
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    542

    Re: Trouble releasing front element retaining ring of 178mm Kodak Ektar - images incl

    I have taken out 2 sheared brass bolts (M1.6 JIS) by drilling very carefully in them with a 0.5mm drill in a hand holder. Takes some time but when I was through (about 3mm deep) I inderted a square reamer as is used for plastic modelling. This had enough grip to remove the screws.

    I'm now going to look for such an oscilloscope lens.
    Expert in non-working solutions.

  7. #7
    Tin Can's Avatar
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    Re: Trouble releasing front element retaining ring of 178mm Kodak Ektar - images incl

    I have 2

    Quote Originally Posted by Havoc View Post
    I have taken out 2 sheared brass bolts (M1.6 JIS) by drilling very carefully in them with a 0.5mm drill in a hand holder. Takes some time but when I was through (about 3mm deep) I inderted a square reamer as is used for plastic modelling. This had enough grip to remove the screws.

    I'm now going to look for such an oscilloscope lens.
    Tin Can

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