Sheet bouncing in front lay cd 74

Discussion in 'Heidelberg Printing Presses' started by Dave Ross, Jan 29, 2011.

  1. Dave Ross

    Dave Ross Member

    Joined:
    Apr 2010
    Messages:
    7
    Location:
    Japan
    Hi all
    We have a problem with mis-register due to the sheet bouncing ,it is only when we use drive side lay it bounces on the operators side the feed board is all air ( eg tape and side lay etc) we have tried different levels of suction etc but nothing seems to work we also have double image randomly on the cyan unit ( unit 2 ) heidleberg have checked and replaced pads etc but again the problem persists.

    Any ideas would be great

    Cheers all

    Dave
     
  2. jmt

    jmt Senior Member

    Joined:
    Oct 2008
    Messages:
    126
    Location:
    new brunswick canada
    did you get the retro fit for filters for your suction pull guides.we use to get problems when the pull guides got plugged with powder we had to clean them daily.or have you checked your lays to see if there all open or closed we also had a problem with sheet bounce because one sidelay was not closed all the way was packed with powder.
     
  3. turbotom1052

    turbotom1052 Senior Member

    Joined:
    Oct 2008
    Messages:
    1,044
    Location:
    Vermont
    have you tried turning off the auto sheet timing and manually adjusting feeder timing to try and eliminate the bounce? if you can successfully eliminate the bounce in this way then id say that your auto timing may need to be looked at. What does your midi display show as the press is running??? For a more detailed look at whats happening at your headstops you can switch to the feeder display on your cp2000 screen. If you notice that the sheet timing seems to be consistently early to the headstops this may very well account for some of the bounce although if its really bad you will usually see the press stopping dead. Also you can turn off the sheet cocking and manually control that if you notice that the stream of sheets are coming down the feedboard crooked.
     
Loading...