Weak springs on a Graflok back.

Discussion in 'Camera Building, Repairs & Modification' started by Wade D, Apr 23, 2012.

  1. Wade D

    Wade D Member

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    I'm restoring an old Graflok back. Cleaning, painting, new GG, etc. The one thing I've noticed is that when the GG section is slid in it has a bit of movement. Probably 1 or 1.5mm, fore and aft, which would affect focus. Visually the springs look OK and the chrome arms aren't bent. Are the springs just weak from age? What would be a good fix for this other than buying another back or springs (if they can even be found)?
    Thanks for any suggestions,
    Wade
     
  2. Old-N-Feeble

    Old-N-Feeble Subscriber

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    Did the original focusing screen have a Fresnel lens? If it did, and you didn't reinstall it, this is why the new GG is loose.

    ETA: You are asking about the retaining fasteners for the GG, right?
     
    Last edited by a moderator: Apr 23, 2012
  3. rjbuzzclick

    rjbuzzclick Member

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    You could try cleaning the pivot point of the chrome arms with some naphtha, and then letting a drop or two of light oil work it's way in there. It helped mine a lot.
     
  4. E. von Hoegh

    E. von Hoegh Member

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    The springs could be weakened from inserting something thicker than the normal filmholders, or there could be crud preventing the springs working as they should. Finding another frame might be the easiest fix, these things aren't scarce. Yet.
     
  5. mopar_guy

    mopar_guy Subscriber

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    Yup.
     
  6. richard ide

    richard ide Member

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    Can you remove the springs and bend them gently a little so that they will apply more pressure? If you can they will be as good as new or better.
     
  7. mopar_guy

    mopar_guy Subscriber

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    Probably the GG is a different thickness or a fresnel lens is missing. The frame is made of aluminum pot metal and can corrode. The "chrome" arms can be lubed with a light grease or a drop or two of oil and worked back and forth a few times to loosen them up.
     
    Last edited by a moderator: Apr 23, 2012
  8. Wade D

    Wade D Member

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    Not the retaining clips for the GG. The broken GG fit snug and the new one does too. I don't think this version had a Fresnel. It's the springs that tension the hold down arms for the whole back.

    I will try a more thorough cleaning of the springs and pivots and add light oil sparingly to see if that does the job. If not maybe the springs can be bent slightly as suggested.

    My first thought was to bend the arms but that notion passed quickly as they might break. They look strong being a 'chrome' color but not knowing the actual metal it was a chance I didn't want to take.

    It's true there are more on the market. Prices, especially on ebay, can get way too high though. I paid less than $100 for an entire Crown Graphic with the back. The only things wrong were the back and folding hood so I don't have a lot invested in this project.
    Thanks for the suggestions so far,
    Wade
     
  9. fotch

    fotch Member

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    I would not bend the springs. The metal is formed then heat treated to the proper hardness to create the spring. Bending after heat treating could either break them and/or cause a fracture, which will eventually break.
     
  10. Old-N-Feeble

    Old-N-Feeble Subscriber

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    If it's the big Graflok springs then I'd try cleaning and lubing... as others already suggested. I can't remember the way they're made but, if they're coil springs, then maybe they just need to be tightened another turn?
     
  11. E. von Hoegh

    E. von Hoegh Member

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    They resemble clothespin springs. Tightening another turn won't happen. What might work is shimming the ends of the springs.
     
  12. Wade D

    Wade D Member

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    Thanks again for all of the replies. I'm not in a hurry to get this done so I will carefully weigh all of the options presented. Will post my final solution when done.