Repairing Mamiya Sekor 65mm shutter

Discussion in 'Medium Format Cameras and Accessories' started by fotoroberto, Aug 12, 2008.

  1. fotoroberto

    fotoroberto Member

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    Hi, I got an old Mamiya Sekor 65mm 6,3 for Mamiya Universal/Press/Super 23, and it's shutter is malfunctioning.
    from what it seems to me, the lubricant got sticky.
    I will open it and clean it myself, but I need to know is there any catch or some more info about the procedure.
    Any link to info or some help would be appreciated.

    Thanks in advance...
     
  2. Wolfgang AM

    Wolfgang AM Member

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    I had the same problem. I think especially the 65mm Sekors for Universal/Press are prone of becoming sticky.
    In my case the following procedure was working well:
    Dismantle the shutterLens from the rest.
    Screw off the front and the rear lens.
    Put this in a bath of benzine (used for cleaning) for a while.
    Run the shutter in wet condition and also move the aperture to let the solvent wash away the residues.
    Let the whole thing dry. A cotton bud is helpful to take up the rest of solvents, that still can contain some sticky lubricant.

    If this does not help you have probably another problem than sticky lubricant.
    To take appart is not a real problem. I did it once with success. It is not too tricky.

    Have fun
     
  3. Mike Wilde

    Mike Wilde Member

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    naptha - aka white gas

    same recommendation as the previous poster, except my preference is what runs my camp stove. The stuff is very volatile. It seems to spread around the gummed up grease, rather than take too much of the lubrication away. The liquid goes in clear and comes out slightly darker, so something is dissolving.

    DO NOT try to move the aperture while the assembly is 'wet' with solvent if you have to work on a lens where the shutter and aperture do not separate easily. I would recommend stop down to f22 etc so there is less blade area overlapping when wet - they I think tend to dry out a bit faster this way.

    Gingerly try to move the aperture and only if you see all blades are moving the same amount after it has been soaked. otherwise try to soak up any solvent in the creases with q tips, etc.
     
  4. fotoroberto

    fotoroberto Member

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    Thanks for the tip, I'll try it as soon as I found some time to do it properly...
    So for the cleaning process, best thing to use would be a benzine used for cleaning...
     
  5. fotoroberto

    fotoroberto Member

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    OK, I did it...
    now it's better, but it seems that speed gear assembly is still malfunctioning, although i got it to work through almost all settings, second, and half a second still don't work right, along with a quarter second some of the time...
    I tried working out the speed assembly and it seems to be stucking in the middle of the way, not going up and down all the way...
    maybe it would be the best if i could get that part somewhere and replace it...
     
  6. crumpet8

    crumpet8 Member

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    A little late to this discussion, but do you guys have some photos of the cleaning to post so I can give it a go on my 150mm?