How to stiffen the dark slide lock pins?

Discussion in 'Large Format' started by michael_mutmansky|1, May 8, 2003.

  1. Greetings group,

    After another outing into the field with the 8x10, I am a bit
    frustrated at the general design of the modern Fidelity holders that
    are available. Most of the holders I have (all modern Fidelity)
    have fairly loose dark slide lock pins. You know, the little
    metal 'L' shaped pieces of metal that are supposed to turn and keep
    the dark slide from being inadvertantly pulled?

    These locks are of no use if they are able to easily swivel out of
    the way with a brush of the hand or by gravity. They need enough
    friction to be put in place and stay there until an intentional act
    rotates them to free the darkslide.

    In older wood holders these were made like a screw, and the friction
    was tight enought to keep them in place. Of the 10 Fidelity holdes
    I have, about 7 have very freely turning locking pins. The other 3
    have enough friction to be of minor utility.

    Does anyone know if there is an easy way to stiffen them without
    major surgery? I'm hoping that there is an adhesive or other
    compound that can be touched to the pin, and be sucked into the
    interface area by capillary action. Maybe a thread locking compound
    or something similar.

    Anyone have any success with these otherwise worthless locking pins?

  2. Michael: Generally, unless they are stripped out, they will screw in if you turn them clockwise. (They are just threaded hooks.) As they get lower and closer to the dark side from turning they grab it with more authority. The more threads that are engaged the harder they are to turn, eventually you get an interference with the dark slide which holds it quite securely.
  3. Kevin,

    That is correct for the wood holders I have (7x17 and 12x20), but the plastic Fidelity holders do not have the threaded locking pin. It is press fit into the plastic (I think), and has little friction to hold it in the locked position. Turning the locking pin (to screw it in) does not produce any results, and the pin does not advance in or out.

  4. Turn the "L" shaped pin to lock, then pull on the darkslide back against the pin tighly, the pin won't turn because of the contact with the darkslide. I hope this help...
  5. I agree with you about the "modern" holders. That is why I continue to search the older wooded holder with the metal loop to pull the dark slide and the screws that are tight. On my modern holders I have started to use rubber bands to secure the dark slide in place. Please let us know if there is a thread locking liquid (locktite??)
    Good Luck, FWB
  6. On my 8x10" Lisco Regal holders, the pins screw in and out. Maybe yours are stripped. You could try to unscrew them, fill in the holes with epoxy, drill new pilot holes, and screw them back in.

    If your pins were clearly not designed to screw in and out, you might try to bend them to make them a little tighter. To do this, I would remove the darkslides, hold the long part of the pin with a pliers or visegrips and bend the short part of the pin down a bit with another pliers or perhaps a few light taps with a hammer. To do this with a hammer, I would orient the holder in such a way on the edge of the workbench so that the pliers holding the pin absorbs the blow of the hammer, and not the holder.
  7. Michael: I'll check some of mine tonight. My Lisco's and Graphic's do tighten. That blue painters' tape with the not-terribly-sticky adhesive works well and leaves no residue. When loaded, put a small strip along the slide and on the long side of the holder. Pull toward the hinge to free up the holder for use. Stick in on the tripod leg until you're done and reapply. This has worked well for me on the ones where I am missing the hooks.
  8. Kevin Crisp is correct; the best solution is tape. I started doing this many years ago and never have problems with dark slides accidentally being pulled out.
  9. Do the "L"s wobble in thier holes? If there is enough room, you might be able to wiggle some sort of bushing into the union---maybe that heat shrink tubing from the electric dept. at the hardware store? Perhaps a wrap of friction tape? No, it could create a static discharge in the darkroom loading process---skip that. How about a piece of brass tubing or sim stock of the appropriate size? You'd have to slit tubing as it probably couldn't be 'worked' around the 'L' bend. Good luck!
  10. I'll also second the tape suggestion. I put masking tape over the darkslides of loaded holders while they're sitting on the shelf or in my bag waiting to be used, labeled with the type of film in the holder.

    I still like having locks that work, though.
  11. Thanks for the responses everyone.

    I'm a bit suprised that a better solution than tape has not been found. Tape is fine, but requires carrying one more item (tape!) and you also must remove it before putting the holder into the camera.

    I am careful enough that I rarely fog film anymore, so that is not really the issue, although I'd much rather not have to be so careful of the darkslide tabs. I actually find the loose locks more bothersom when changing film, because they constantly get turned into the way when it's time to unload and load film.

    Ultimately, I can't stand having a feature that is of little utility on the holders. It seems to me that if they are going to put them on there, they should work well enough to be of use.

  12. I started with tape and switched to wide flat rubber bands. A couple rubber bands around the holder, over the locks, hold the
    locks in place, add a level of security and fit in my pocket in the field. I place bands around locks when I load film, then add a
    third band around the middle after exposure. I can immediately see what has film and what's been exposed from a distance. I also
    carry a couple empty holders and boxed film I might need. These holders have no rubber bands and never get mixed up.

    On the other hand I hope someone knows how to fix those lose Fidelity pins. I have a bunch of 4x5s and I just passed up a deal
    on a stack new 5x7s because I knew this would be a problem in the future.
  13. Try a piece of electrical shrink-tubing or a tube of insulation cut from a heavier gauge wire. slip it over the end of the 'L' and it will take up some/all of the gap. The heat-shrink tubing is generally better. once shrunk, it stays pretty firmly and if the first application isn't thick enough, you can usually fit another layer over it.

    Good luck
  14. Michael: You don't have to carry the tape, just put the strip on right after you load them. Park it on the nearest tripod leg when you shoot, and put it back. (If you pull it off away from the hinge, of course, you might accidentally pull the slide out prematurely.) The tape is good for several loading/unloading cycles, and the blue painters is just sticky enough. I checked some of my fidelity holders and the hooks do seem to just turn. You could put a thin strip of gaffers tape on the edge of the dark slide, which would decrease the the clearance without moving the hook. I hadn't thought of rubber bands.

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