Home Made Registration Punch and Carrier?

Discussion in 'Darkroom Developing and Printing' started by john, Jun 1, 2008.

  1. john

    john Guest

    Registration punches and carriers for projection (enlarging) 8x10
    and also for contact printing 8x10 and larger.

    All I've found so far are very large registration punches intended for
    nonphotographic printing, or some dauntingly expensive photographic systems.

    Desperation (the father mother of invention) leads me to think a decent
    system can be made 'at home' or with some straightforward machining. My
    major question at the moment is how the negative and mask is held in place.
    I presumed, perhaps incorrectly, that they are held without glass. Is that
    correct?

    Not so important notes of progress: Work on the Saltzman 8x10 enlarger
    continues. Today I am finishing a filter holder, fitting the negative glass,
    adding a measure/scale and other odds and ends. So far it is looking quite
    good. I am still undecided on what to do about the ruined wood baseboard.
    One interesting thing - most of the fasteners were torqued to lower than
    expected values. All were seated squarely, but none whatsoever were tight,
    nonetheless the assembly was rigid. Even the 3/4", fine thread, grade five
    bolts were torqued to about 20 pounds. That is far from their capability
    (wet torque spec - many were oiled before seating). Another way to put that
    is that the designer used fastener girth and grade rather than torque for
    rigitity, which is a good thing. Expensive, but good! So as I reassemble
    with new fasteners of the same grade I am accepting the lower torque values
    and will work from there.
     
    john, Jun 1, 2008
    #1
    1. Advertisements

  2. If you are careful you can use a standard office paper punch.

    You will need some loose registration pins. It is common
    to use one round pin and one diamond pin. The diamond pin
    is inserted so that its long axis is perpendicular to the
    line between the registration holes. This allows some
    slop when punching the holes but still maintains good
    registration: the round pin defines a common rotational
    point and the diamond pit defines the angle between the
    sheets. If you use two round pins the system is over-constrained
    and any misalignment will cause the sheets to buckle.

    Nikon uses a round/diamond pin registration scheme between its
    F3 camera and the MD4 motor drive.
     
    Nicholas O. Lindan, Jun 1, 2008
    #2
    1. Advertisements

  3. I may be getting confused here - it is a round pin and a slotted
    pin. The slotted pin has its sides ground off and normally goes
    into a slotted hole punched in the sheets.

    You many need to get diamond pins ground down from round
    pins at a machine shop.
     
    Nicholas O. Lindan, Jun 1, 2008
    #3
  4. Pardon me if I misunderstand what you're trying to do, but if you simply
    need to keep a negative and another piece of film (mask) in register for
    an exposure, that should be pretty simple, no?

    Assuming you have some way of accurately aligning negative and mask, all
    a guy would want to do would be to punch two widely-spaced holes in the
    "sandwich". Then the enlarger would have register pins in the
    appropriate places to receive the sandwich.

    I'm sure you know that the register pins used in graphic arts are still
    readily available and could easily be mounted to just about anything.

    Every print shop I ever worked in that used film handled it in pretty
    much the same way: a simple punch (usually something homemade or
    jerry-rigged) to make the holes, and register pins at exposure time,
    usually taped down. Simple, effective, low-tech.

    Contrary to what Nicholas said, there's no reason to use anything but
    regular round pins. Two pins will keep the sheets in exact alignment no
    matter what their shape, so long as the holes are sized exactly to the pins.
     
    David Nebenzahl, Jun 2, 2008
    #4
  5. john

    gr Guest

    The reason that a round hole is paired with slotted holes (on larger
    punches it is one round hole and several slotted holes) is that the
    polyester film base expands and contracts in size with temperature and
    humidity changes (approx 0.001" change in 10" for every 10% humidity
    change). With round pins a size expansion is trapped and causes the film
    to bow, preventing good contact and registration. A slotted pin allows
    the film to slide in the expansion direction but prevents rotation and
    maintains registration.
    gr
     
    gr, Jun 3, 2008
    #5
  6. That makes sense, and it's true I've never worked in a shop that handled
    really big film (for big presses). But in this case, the expansion
    factor is probably minimal, since the O.P. is dealing with 8x10 film.
     
    David Nebenzahl, Jun 3, 2008
    #6
  7. john

    john Guest

    Perfect, or as good as possible registration is the issue.
    That is exacly the problem, David. Perfect alignment with home tools to make
    the carrier and punch.
    All I have found are far too large, in the 30" range.
    I should add - this is for enlarging 8x10 negatives, not for contacting so
    the degree of misalignment is magnified. Perhaps enlarging with a mask is
    not the way to go.
     
    john, Jun 4, 2008
    #7
  8. john

    john Guest

    Someone made an 8x10 (perhaps 10x10) film holder that clipped to the edges
    of the film and drew it out under mild tension. That seems to be a good idea
    if it can be held by the registration pins. I guess we will just have to
    make it and find out.
     
    john, Jun 4, 2008
    #8
  9. Hmmm; maybe you don't know what I mean. The registration pins printers
    (used to) use are little metal tabs, maybe an inch and a half long by an
    inch or so, stainless steel, with a short (1/8" or less) pin attached.
    The pin goes in the hole, and the tab gets taped down to the light
    table/exposure frame/whatever. Very simple to use, and could definitely
    be machined for permanent or semi-permanent attachment to your homemade rig.

    Does that help any?

    Hard to find pictures online; the closest I could find is this, with a
    crude sketch showing a "peg bar" used for animation:
    http://www.glennview.com/dkrm2.htm. Just imagine the center pin only on
    a much smaller tab. (This also shows the use of rectangular slots and
    pegs to allow for substrate size changes described elsewhere in this
    thread.)

    P.S.: While searching for pictures of pins, I ran across this page which
    has a lot of stuff about Saltzman enlargers, registration carriers,
    etc., in case you don't already know about it:
    http://www.glennview.com/dkrm2.htm
     
    David Nebenzahl, Jun 4, 2008
    #9
  10. David Nebenzahl, Jun 4, 2008
    #10
  11. john

    john Guest

    Pins are no problem. It is the build of the jig and the build of the
    negative carrier that matches the pin holes.
    I know that prick. He doesn't answer his email. I had several thousand
    dollars to spend, identified the stuff I was considering, wrote to ask if I
    could make an appointment to see the stuff in person and he decided he was
    too rich to sell. **** him.
     
    john, Jun 4, 2008
    #11
  12. The pins (about the size of a pencil eraser) can take several forms:

    o pins inserted into, say, a negative carrier
    o pins inserted into a registration board
    o pins inserted into a support board for use in a vacuum frame
    o pins inserted into a printing press
    o pins inserted into a bar
    o pins that can slide in a bar
    o pins spot welded to a little thin metal disk - used loose
    o pins spot welded to a small shim-stock metal rectangle,
    the rectangle is taped to the table/carrier/whatever

    It is the punch that is the big item in all this. If the
    system uses round pins then the distance between the punched
    holes has to be held constant.

    Since nothing can be held constant, the punch usually makes
    one round hole and one or more slotted holes so the location
    of the second hole(s) isn't so critical. It is possible to
    punch a round/slotted hole systems by hand with a pair of
    1-hole punches, though not recommended.

    Very large films use a central round pin and two slotted pins
    along the long side and a round 'tail pin' in a perpendicular
    slot in the middle of the opposite edge. The punches for this
    work are large and expensive.

    Punch systems are ANSI/ISO etc. standard.

    In graphic arts the punch registration system is used all the
    way from the initial films, through the contacting films and
    printing plates and on to the printing press.

    There are standard punch systems used for hand-drawn animation
    to holds gels in register.

    For 4x5 work the standard cheap way to work is with a 2-hole
    paper punch and loose pins. The negative carrier has clearance
    holes drilled in to it for the pins. For 8x10, a 3-hole punch with
    the center punch disabled is a standard solution.
     
    Nicholas O. Lindan, Jun 5, 2008
    #12
  13. John,

    The easiest way is to punch a piece of polyester or mylar with a 3 hole punch, though I
    remove the middle punch myself. Insert your pins into the holes, with the tabs away from
    the material, tape/glue/VHB (whatever your preferred attachment method)the pins to the
    carrier/light table/etc.

    It may not be rocket science, or precision machining, but that's how I do it every day
    when I strip negatives for plates at work, and it works just fine, though we do have
    several of the fancy punches, at home I use the 3 hole punch just fine. (if you need some
    tabs, I can probably liberate a couple, or at least find a source that doesn't require you
    to buy a dozen/gross/container load at a time)


    erie
     
    erie patsellis, Jun 8, 2008
    #13
  14. john

    John Guest

    That's an interesting technique. Thanks very much, Erie. Have you made
    any masked enlargements in your 10x10" machine?

    John (Pico)
     
    John, Jun 9, 2008
    #14
  15. I hope to have it set up by the end of summer, damn work and commercial customers keep
    getting in the way. I have some space available (about 800 sq. ft.) to me that I can set
    up the railroad track in, and get some of my other "treasures" out of storage as well. You
    might want to consider it, as I offered before, it's only a 10 hour drive or so....;)


    erie
     
    erie patsellis, Jun 10, 2008
    #15
  16. john

    John Guest

    Ten hours. That is about 24 gallons of gas. See what measures we've come
    to? But wait, how many sheets of 8x10 B&W film is that? OMH, I'm getting
    so depressed.
     
    John, Jun 12, 2008
    #16
  17. Naw, don't go there, I've been building 16x20 film holders, pining for the day when I can
    shoot "real" film, instead of lith film. (20x24 are next). I can make Eau Claire in about
    7 when I visit the grandkids (3 if I fly, but if you think auto gas is expensive, not to
    mention tie down fees, etc.)to give you an idea.

    On a positive note,and in having at least something to do with r.p.darkroom, I got my W-L
    Pro6 processor home last weekend, set up the temps and process times last night and
    proceeded to dry run some empty film reels(using water in all the tanks, just in case of
    course) 10 runs, time/temp compensation working like a champ, process temps and times
    right on the money, good bye hand C41, this is going to be a fun summer, dammit. (not to
    mention not having the tech bitch about cross processing to me every time I drop off film.)

    So if anybody (or you know anybody) that needs parts for a Wing Lynch mode 4 (except for
    heaters, those I'm keeping with a few tanks.) I've got a complete one, tubes, all cards,
    etc. that I'm parting out.


    erie
     
    erie patsellis, Jun 12, 2008
    #17
  18. john

    John Guest

    See how ignorant I am - I never heard of a Wing Lynch. You have quite
    the setup.

    Pico John
     
    John, Jun 12, 2008
    #18
  19. John, I'll PM some pics tomorrow over on the "film site"....



    erie
     
    erie patsellis, Jun 12, 2008
    #19
    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.