Help!!! Canon A1 film rewind knob fell into the camera

Discussion in 'Camera Building, Repairs & Modification' started by jessica20, Jun 18, 2014.

  1. jessica20

    jessica20 Member

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    My film rewind knob fell into the camera and the back cover is locked. Without the knob, I have no idea how to get the cover opened. I have tried using dentist pick to try to unlock the door, but it doesn't work:sad: I don't know the structure of the door lock!
    Can anyone help? How can I open the door without the knob?
    thanks
     
  2. trythis

    trythis Subscriber

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    I think if you take off the bottom plate you can push up on the mechanism. Not positive but just dont touch the electronics. Fragile bits.

    sent from phone. excuse my typing.
     
  3. Xmas

    Xmas Member

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    I assume the rewind shaft has fallen to cassette chamber?

    Ive not got or had one apart but the norm is that a circlip or recess on the shaft lifts a spring loaded finger.

    You need a bright flash light to identify possible bits of fianger and you might need two dental picks one each side of actuating finger

    when you fix stick masking tape over door latch...
     
  4. mr rusty

    mr rusty Subscriber

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    Not sure on the canon, but on an olympus the rewind "pin" has two flanges at its end that engage on the bush it passes through and the shaft pulls up the whole bush when you lift it. A simple hook pushed through the hole and caught under the bottom edge and lifted opens the back.

    hth
     
  5. shutterfinger

    shutterfinger Member

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    http://www.mir.com.my/rb/photography/companies/canon/fdresources/SLRs/a1/html/index8.htm
    I assume there is no film cassette in the camera. Take a heavy weight paper clip and straighten the open end outward. Using a pair of pliers bend 1/8 inch of the end of the wire 90°, it should look like a L. Insert the L through the opening then turn the short end against the outside edge of the camera and pull up. The back should open.
    Put any loose washers back on the rewind shaft then put the shaft through the hole in the camera top. Thread the rewind knob onto the shaft then hold the shaft stationary and tight the knob firmly.
     
  6. AgX

    AgX Member

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    I just had a look at my AE-1 with assumption that the lock is the same:

    -) at this location the body has a 2-layer shell: the outer cover and the casing of the take-up chamber

    -) the door lock is situated at the small side of the camera between those 2 shells, unaccessible from the inside

    -) access to that lock via the outer shell is blocked by the flange of the back-door


    But the lock is actuated from the top anyway:

    -) the latch has got a right angle that protrudes under the top cover where the rewind axle arrests against it whilst pulling up

    -) you might form a hook and insert it into the hole to mimic this action (as Shutterfinger just described)

    -) if you fail you have to take off the top cover (the only difficult stage is taking off the rewind lever)


    -) for remounting the knob/crank look for a tool that fits flat as good as possible into that "fork" end of the re-wind axle. Maybe you have to file your tool up to size. Then screw the knob on using your tool for counter force.
     
    Last edited by a moderator: Jun 18, 2014
  7. jessica20

    jessica20 Member

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    Guys! Thanks for all you detailed solutions:smile: My dad just helped me to fix it! Never let the knob fall into the camera like this again:smile: Thanks and happy shooting:smile:
     
  8. John Koehrer

    John Koehrer Subscriber

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    That's what dad's are for.
     
  9. mr rusty

    mr rusty Subscriber

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    just noticed it was your first post. Welcome to apug. Here to help with all questions analogue. Hopefully see some pictures from you soon. :smile:
     
  10. Peter Simpson

    Peter Simpson Member

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    Dads...and Loctite (242, I think - removeable, it's blue in color). Get a small bottle at your local auto parts store. Use a toothpick to put a tiny bit on the threads of the screw so it doesn't happen again. I use it on lots of stuff where unscrewing would be problematic. Like the bolts that hold the rear carrier to my bicycle. It doesn't like plastic. Great stuff.
     
  11. F4user

    F4user Member

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    For long term storage as you used only a drop from the bottle
    -don't allow be in touch with any metal, never-ever. Will start to harden entire bottle.
    -once at three month open the bottle and allow fresh air to enter, squeeze the bottle.
    solution start to harden when lack of oxygen.
     
  12. Xmas

    Xmas Member

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    Pros use nail varnish after knob is screwed down, easier to undo after nail varnish remover qtip scurbbing hard. But the knobs normally don't loosen off as they tighten with use, checking they are tight is still a good idea.
     
  13. AgX

    AgX Member

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    That warning of touching metals only refers to clogging the tip of the tube not the whole Loctite screw-fastener bottle. Though they also worn not to get any material back into the bottle. Also not to keep it at fridge temperatures.
    All this is new. In the past Locticte even specifically advised to use a needle to open the tubes of virgin bottles and to stitch the needle even deep into the tube.

    Thank you for that update!

    I still got that stuff using the tube directly on metal and it still works after two decades...
     
    Last edited by a moderator: Jun 20, 2014