Plate wind up problem

Discussion in 'DI Presses' started by maverick1971, May 27, 2014.

  1. maverick1971

    maverick1971 Senior Member

    Joined:
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    Location:
    South Africa
    Hi All,

    We are experiencing problems with our plate wind up mechanisms on our 1996 QMDI 46-4. After approx. 8 sets of plates from a new set of plate rolls, the wind up mechanisms are winding up too much plate material at each imaging cycle.

    This is resulting in large amounts of plate material being wasted. At the current price we are paying for Presstek plates, this is adding up to a huge amount in losses!!!

    How do we fix this? We have tried adjusting the screw on the inside of the plate cylinder where the feed plate roll sits - this seems to help for only a few more imaging cycles and then the problem returns. If the screw is loosened too much, then the plate material does not wind up enough or the screw falls out.

    Is there a problem with the clutch mechanisms? Are they worn out or just slipping due to grease or dirt build-up?

    How can we overcome this problem? Any assistance would be appreciated.

    Thanking you in advance.

    Kind regards

    Shawn
     
    Last edited: May 27, 2014
  2. Paul Cavanaugh

    Paul Cavanaugh Senior Member

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    Location:
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    The clutch mechanism must be set to release the plate material at 20 - 22 nm. This must be tested with a full roll of material and a spring scale. (Like you would use for weighing a fish.) If the clutch is set to loose it will advance too much plate material.

    Also it is very important when installing a partial roll that it is measured properly. If the measurement of the roll diameter is incorrect the machine will start spooling more and more material each time it performs a plate advance. After 8 plates or so there willbe an 8" gap in between each plate.
     
  3. maverick1971

    maverick1971 Senior Member

    Joined:
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    Location:
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    Hi Paul,

    Thank you for your reply. I have tried as far as possible NOT to install partial rolls. When we install a new roll however, the machine spools the plates correctly for the first 8-10 plates and then the problem starts again. Is this common?

    I will try and set the spooling clutch to the correct torque as you indicated. Our Heidelberg tech is with us from tomorrow for a couple of days so I hope we can resolve this issue. We are in the process of installing a second DI we bought recently.

    Thanks again!
     
  4. Paul Cavanaugh

    Paul Cavanaugh Senior Member

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    I meant to ask... Is this happening on all the units or just a few?
     
  5. maverick1971

    maverick1971 Senior Member

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    Location:
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    Hi Paul,

    This is not happening on all the units at the same time! It does happen on at least three units but at different times (our plate consumption on the different units is not always the same as we run some jobs without CYAN for example) - depending how far into the plate roll we are.

    On a different issue - could I send you a private e-mail to address another problem please? Please send me your e-mail address. Please send to:

    info@acaciaprinters.co.za

    Thank you!
     
  6. qmdipress1

    qmdipress1 WWW.QMDIPRESS.COM

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    Paul
    I get calls about this all the time. Now I know what to tell them Thanks…...
     

  7. Paul Cavanaugh

    Paul Cavanaugh Senior Member

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    Location:
    Kennesaw, GA
    Every once in awhile I have a nugget of useful information...
     
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