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  1. #11

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    Yes, I think opening these shutters should be left to the experts who, I understand use ultrasonic cleaning.

    This thread motivated me today to measure the shutter on my new-to-me Century 2x3 with the Wollensak Syncromatic C / Graftar 1/4.5 103mm
    { speed, ideal, measured millisecond}
    {1/10, 100, 95}, {1/25, 40, 40}, {1/50, 20, 25}, {1/100, 10, 15}, {1/200, 5, 5}

    Below is a trace of the 1/50 measurement showing how I use the mid-point of the rise and fall times - (shutter is halfway to maximum transmission)
    I don't know how they measured them back in the day.
    The ripple on top is 120 Hz ( 8.33 millisecond) from the test lamp I use. I should put a rectifier filter, however it allows a useful cross check of the time, in this case 8.33 ms by about 3 cycles.
    Attached Thumbnails Attached Thumbnails Graftar_1_50th.jpg  

  2. #12
    fotch's Avatar
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    The only way you can truly clean anything is to take it apart. Just flushing it with some fluid is not really a cleaning.
    Items for sale or trade at www.Camera35.com

  3. #13

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    Thin precision parts not designed for a high vibration environment... in an ultrasonic cleaner. Not in any precision shop that cares about fatigue life. Be very careful. Ultrasonic are fairly violent due to hi rep rate and creating cavitation.

  4. #14

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    wombat2go,
    Since the pulse will only be there when you fire the shutter do you need a storage type oscilloscope?

  5. #15

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    Quote Originally Posted by ChuckP View Post
    wombat2go,
    Since the pulse will only be there when you fire the shutter do you need a storage type oscilloscope?
    Yes but my storage scope it out of action. Here is how I did it with an old analog scope and a digital camera.
    (Sorry: I have been posting links on this forum but now I can not. Mods say it is because i am new member... but I have quite a lot of posts already with links)
    So please refer to my thread on PentaxForums >Articles>DIY "K-01 Oscilloscope Adaptor"

  6. #16

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    Quote Originally Posted by Tom1956 View Post
    Now mind you, I'm rather early on in my shutter studies and work. But it's becoming more evident that spring replacement is the correct remedy for getting these shutters back to speed--the Betax. Rapax, Compur, etc. This of course is leading to the need to learn spring fabrication, since no parts I know of are available.
    If regular users are going to do the naptha-related tricks to get a dead shutter at least working again, then fine. But if you are not following it up with a little tester, so you can make a conversion chart to stick on the back of the camera, then you still don't have much of nuttin'. You'll be all over the place on finding film speeds and development times. Banging your head against the wall.
    Find out where your shutter really is, and the rest of procedure will start clicking into place. Voice of experience.
    Nonsense. Rubbish. I use shutters from the late 1950s to before WWI. They are accurate and still have the original springs.
    One thing you haven't had occur to you yet is: The shutter blades are often, if not always, steel. Steel can become magnetised. Magnetised shutter blades stick together. Stuck together shutter blades will make the shutter run slow.
    You also have to actually clean the parts, with a brush and peg out all the pivot holes - not just slop them around in solvent. An ultrasonic will damage springs if they are left in long enough.
    Clean the thing, assemble it correctly with degaussed blades, lubricate it properly, and unless it's badly worn or has been butchered by some half-baked autodidact the speeds will come bact to their marked values with gratifying accuracy.
    Last edited by E. von Hoegh; 09-30-2013 at 09:29 AM. Click to view previous post history.

  7. #17

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    The three Graflex shutters I measured over weekend (above posts) are quite accurate.

    This morning I measure a new-in-box Prontor SVS , box says 1957, the shutter is obviously never used.

    { speed, ideal, measured millisecond}
    {1/1, 1000, 1600+}, {1/2, 500, 700}, {1/5, 200, 220}, {1/10, 100, 250},
    {1/25, 40, 76}, {1/50, 20, 30~50}, {1/100, 10, 12~15}, {1/300, 3, 5~7}

    This shutter is slow, and erratic on the 1/50th, note how the 1/10 speed is slower than 1/5
    What should be done with it?
    I might try - warm it up to 45 C for a few hours, fire it 100 times, then re-measure it ??

  8. #18

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    Quote Originally Posted by wombat2go View Post
    The three Graflex shutters I measured over weekend (above posts) are quite accurate.

    This morning I measure a new-in-box Prontor SVS , box says 1957, the shutter is obviously never used.

    { speed, ideal, measured millisecond}
    {1/1, 1000, 1600+}, {1/2, 500, 700}, {1/5, 200, 220}, {1/10, 100, 250},
    {1/25, 40, 76}, {1/50, 20, 30~50}, {1/100, 10, 12~15}, {1/300, 3, 5~7}

    This shutter is slow, and erratic on the 1/50th, note how the 1/10 speed is slower than 1/5
    What should be done with it?
    I might try - warm it up to 45 C for a few hours, fire it 100 times, then re-measure it ??
    Anything other than a proper clean, lube adjust is a stopgap at best. For instance, I have a Yashica screwmount SLR that sat for about 20 years. I did what you suggest with it, and guess what? It sounded - and worked - like new, for a while. The heat and activity moved some lube around. Now the camera still functions at the lower shutter speeds, 500 and 1000 are capping again. Warm it up, or take it out on a warm day, and it's OK.

  9. #19
    Ian Grant's Avatar
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    My 1913 Compur is more accurate than my modern Copals, Says a lot about German engineering and the strength of their springs

    Most important thing to remember with leaf shutters is they need occasional use, that helps keep them running smoothly.

    Ian

  10. #20

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    Quote Originally Posted by Ian Grant View Post
    My 1913 Compur is more accurate than my modern Copals, Says a lot about German engineering and the strength of their springs

    Most important thing to remember with leaf shutters is they need occasional use, that helps keep them running smoothly.

    Ian
    Same experience here... but interestingly they all produce reasonably similar exposure results. The amount of difference in accuracy/precision of well/properly maintained shutters isn't huge.

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