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Thread: Shutter Ideas

  1. #21

    Shutter Ideas

    And in action:

    Attached files

  2. #22

    Shutter Ideas

    Looks like it's going well.
    I've been looking at home made shutters myself recently;
    I think I have worked out a useable shutter design similar to a Copal, but driven by a solenoid and electronics rather than a spring mech.
    So far, I have the input stroke down to 8mm, just about within the range of small (ish) solenoids.
    I'm working on a more compact version at the moment.
    I'm planning to make at least one if costs aren't prohibitive. - Would anyone be interested in one?

  3. #23

    Shutter Ideas

    Ben,
    Do you have the electronic control worked out yet ? The design I outlined will control from milliseconds (in reality, the mechanical max speed of your shutter), up to about 10mins or so. The only limitation that I would impose is that I wouldn't recomend anything longer than say...1m as the caps would start to show their inaccuricies.
    To change my design to suit your needs, use the following equation:

    t=.1.1(RxC)

    What sort of design are you up to ? A leaf type ? If so, where are you going to be getting materials for the leaves ? Also, what size shutter are you going for ?

  4. #24

    Shutter Ideas

    I already have a controller built for another project that will work. it's 555 based and has a range of between about 1/4sec to several minutes, with the current resistor pack. - this could be changed to generate "standard times, though.
    See this thread for more details and a pic:
    http://www.f295.org/DIYforum/cgi-bin...0231036/s-all/


    The design I've provisionally gone for is very much like a standard Copal type.
    At present, the clear aperture is an arbitary 30mm. I don't actually have an LF shutter myself, so I'm not sure of the dimentions required.
    If I actually make it, however, I'll definately get a proper measurement and lens thread(s) on it.

    I was planning to have the leaves laser cut from spring steel, if it didn't cost too much. - This is why I asked if there was any interest from anyone else, as I may have to have a full sheet of material lasered, which would probably be rather expensive for a one-off single unit build.

    Although for a test rigup, I could probably use hacked up floppy disk shutters, and a simplified leaf outline, to facilitate cutting with tinsnips.
    I have a contact with a Biglia 6-axis CNC lathe, who could make the main body and mechanism of the shutter (for this, I was planning on using Aluminium, or possibly Brass).
    If anyone was interested, I would probably be able to have multiple units machined at less cost than several 1-offs.
    The solenoid would probably be an off -the -shelf part

    It's all very much in the air at the moment, but I'd be interested to hear your (or anyone else's) views on the idea.

    Attached is an exploded concept pic. The solenoid drive would be attached to the little lever. (suitably redesigned to be actuated by a solenoid, of course) Attached files

  5. #25

    Shutter Ideas

    If you use Aluminum, you might want to anodize it. A good quality spring steel might be a better choice.


    http://www.smallparts.com might have what you need.

  6. #26

    Shutter Ideas

    Ben,
    What are you going to be using this shutter on ? Sorry, I haven't gotten a chance to go back through all the threads yet - Im new here .
    As for your shutter, it looks pretty good. I take it you are going to use electronic control to open/close the shutter. If you're going to be needing a semi-standard size, why not chop a factory shutter ? You can find non-working ones CHEAP.
    I would use Aluminum over brass for weight purposes.....Obviously for a mechanism, the lighter the better. Also, have you looked at the brass prices lately ? I hope I cut my lens barrel right the first time - because if not - it'll be an alum monster, not a brass beauty.
    Have you put any thought into your solenoid ? For my project, I need one that will give me 1" of throw. Obviously, a plunger type would be best - but all of the ones I have found thus far with a 1" throw have been monsters. I may have to use a rotary type with a larger wheel on the end, affixed to a shaft (ala locomotive style). Being as I don't need much force, I should be able to get away with a very small solenoid.
    As for a relay, check out mouser #653-G5B-1-DC5. If you run your 555 circuit off of 9vdc, you'll get about 5.7vdc out of pin 3, with a max of about 100mA. That relay has a draw of 72mA @ 5vdc, and it is rated to switch 3A @ 120vac.

  7. #27

    Shutter Ideas

    Greg; I was planning on using laser cut spring steel for the actual thing - I just mentioned Ali as a temporary experimental material - Cutting spring steel with tinsnips tends to take more metal off the tinsnips than the stock

    Steve; I picked up an Arca-swiss 5x4 monorail as scrap a while back, and I want to get it fixed up.
    Making a shutter looks interesting.
    On the Solenoid front, I'm planning to use something standard off the shelf. On the current design, I only need about 8mm of drive. I can fine tune this by varying the lever length.
    I might hack a "real" shutter, although finding somewhere to attach the solenoid is likely to be difficult.
    If I can get one really cheap, I might have a look at this option.

    The relay in my controller is my standard "does-everything" relay.
    It suits me down to the ground - physically small, sensitive 12V coil which fires easilly directly from a 555 run at 9v, but a lot of punch on the switch side -DPDT, 250V@16A. ;D
    Suffice to say that with the current PCB layout, the board would melt before the relay even started sweating

  8. #28

    Shutter Ideas

    Ben,
    If you were to hack an OLD two leaf shutter, there is a point at the bottom of the assembly where the two leaves meet. This point is pushed up/down to open/close the leaves. If you had a solenoid that gave you 3mm or so of throw, it would work fine.
    The only problem that you may have with doing this, is that the old shutters usually aren't the correct size for modern glass. Also, I wouldn't push a two leaf shutter past say...1/50th (although my old pronto goes to 1/100th). But again, at those speeds, I don't think a regular solenoid will be able to keep up either.
    If you want to take a look at the guts of one of those old shutters, let me know, as I have an old AGFA sitting around.

  9. #29

    Shutter Ideas

    If you don't need a large shutter, I can't imaginbe anything easier then taking the shutter elements out of an argus C3 and replace the uhm.... rather crappy timing mechanism with yours. The argi are extremely easy to open up, and because the actual parts are not at all fragile, even an argus in horrible condition will be ok to be used for parts. A clear aperture of 30mm will certainly not be big enough for all large format lenses.

    I think a shutter like this would be interesting to make a 6x9 view camera (with a home made lens). When stopped down to about F32 and with ISO 50 rollfilm, all conditions should be OK with a shutter like this. Also, at f32 most aberations of "lower quality" lenses shouldn't matter much. To test you might want to take a lens out of one of the none focussing crappy single plastic element polaroids. From memory I'd guess they have a focal length of about 110mm which is fine for 6x9.

    Using existing lenses is not a good idea I think believe because of the need to mount them to the shutter with correct spacing. Also, because of the "slow" maximum shutter speed you need to stop down quite a bit.

    I think you could sell a simple lens (either single element, 3 element, or symmetrical design) in a simple shutter in surpringly large quantities if you can keep the production cost down. If you ask $150 for lens + shutter you'd still be the cheapest new solution on the market. Better older lenses are available second hand, but buying second hand is always a bet, especially on older lenses and shutters...

  10. #30

    Shutter Ideas

    Steve, how about a solenoid with a half inch of travel and a 2:1 lever to make up the difference. It could of course be scaled to make the inch of travel from a very small solenoid.

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