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  • Digital wallpaper length changing when printed

    Posted by Peter.Mika on 18 December 2010 at 18:15

    Hey guys,
    we have SOLJET 645EX and VersaWorks rip. When we print our Digimura wallpaper we get every print longer or shorter by few mils depend on feed settings. It’s not material expansion. So it might be only feed. We’ve tried media and printer settings.

    With printer settings: we get print sometimes longer by 1.2 cm on 2m length of print and every next print larger by few mils.

    With media settings: we get print much shorter for a change and again few mils larger every next one.

    We’ve checked feeding motor but it has only 450 ruining hrs on it. Strange is that whatever size of print we send to rip we won’t get correct print length, width is fine. It’s not only wallpaper it happens with roll-up media when we print pop-up exhibition stands as well.

    Any idea or did you have same problem anyone?

    Gavin MacMillan replied 14 years, 9 months ago 4 Members · 5 Replies
  • 5 Replies
  • David Rowland

    Member
    18 December 2010 at 18:30

    you should find that every roll-fed printer suffers from the problem, even our hybrid UV printer. Nothing you can do

  • Peter Normington

    Member
    18 December 2010 at 22:42
    quote Dave Rowland:

    you should find that every roll-fed printer suffers from the problem, even our hybrid UV printer. Nothing you can do

    so nothing will match up ?

    are you sure dave?

    Peter

  • David Rowland

    Member
    18 December 2010 at 23:13

    he’s only talking a few mm so it cant be that bad, must be very usable.

    but to get a roll fed to print perfectly every-time is near on impossible, I used to double sided printing every day and it never matched front and back.

    The problems are many:-

    1: Heat can effect the material, makes it give a little
    2: The weight of the roll on the back of the machine goes from heavy to light as it prints.
    3: Our JV3 machine has a clutched based take up system, once you tape the print to the front roller then it’s tugging the material, so the print is actually going to get slightly longer.
    4: Once the front roller gets full then the roller gets less efficient at tugging.

    Sometimes u need to do Live feed rate changes, this will change the length.

    Not forgetting slippage on the rollers!

    Our new UV machine does pull through the media by suction system behind a belt, but I have done tests and its not perfect but might be slightly consistant between prints, maybe a large format roll printer that is used to large weights and uses a belt/suction system might actually be pretty good.

    The Sphul is the only printer I have seen where they have a floating wheel that actually measures the top surface of the media, so it is "supposed" to be the same length each and every time… in theory 😉

  • Chris Wool

    Member
    18 December 2010 at 23:18

    sounds like you have two different feed calibrations the machine setting and the rip profile setting.
    why it should be different on the second print on the same settings heavens knows.

    guessing the way the file is paneled or the first print of the day the material has picked up moisture 2nd 2mt is stabilized.

  • Gavin MacMillan

    Member
    20 December 2010 at 10:19

    I have had similar problems and have read previously that it’s an almost impossible thing to do. Though the reasons you have given Dave don’t really work for me:

    1: I don’t buy that – not enough to alter print length by 12mm
    2: Roll media off the roll first – the weight of the media hanging would not effect it enough
    3: Don’t use a take up
    4: Don’t use a take up

    I’d like to hear from anyone who prints their own pop ups, we tried once (as a refurb) with limited success, nothing else we do matters that much as you can easily fix the problem with vinyl while applying.

    G

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