Heidelberg MOVPH fit problems

Discussion in '4-Color Offset Presses +' started by dduthler, Apr 7, 2012.

  1. dduthler

    dduthler Member

    Joined:
    Dec 2011
    Messages:
    5
    Location:
    Grand Rapids, MI
    I have an issue where my first and second unit fit together fine but unit 3 and 4 wont fit. The press has a perfector and is a four color. I notice it more when running light weight stock but still have an issue with heavy stock. Unit 1 and 2 fit perfect but unit 3 is out around 3 rows of dots on the tail of the sheet. Same with unit 4. It looks like unit 3 and 4 fit each other though. Not sure if this is a issue with the pincer bar or an issue with the jackets. Press is a 1989 with alcolor. around 104 million impressions.
    The only way I get decent fit quality is to use the split tail clamp. After mounting plates I use the split clamp on 1 and 2 to push the edges of the plate towards the center. Then on 3 and 4 I stretch the plate to the op and drive side of the press.
    Problem has gotten worse over the past few months. Also have to stretch the plate on 3 and 4 using the lead edge plate clamp. Basically tighten the lead and tail clamps to the point of ripping the plate.
    Any advice would be great. Still producing jobs but not sure how long before the problem get worse.
     
  2. turbotom1052

    turbotom1052 Senior Member

    Joined:
    Oct 2008
    Messages:
    1,044
    Location:
    Vermont
    where is the perfecter? Have you tried long grain paper? Compensator? Does an MO even have a compensator?
     
  3. NotAGooner

    NotAGooner Senior Member

    Joined:
    Dec 2007
    Messages:
    279
    Location:
    UK
    Yes they do have one but they very easily don't work due to getting seized up.
     
  4. exheidmech

    exheidmech Senior Member

    Joined:
    May 2009
    Messages:
    674
    Location:
    USA
    I can tell you for almost 100% certainty that its the perfector. Might just need a tune up. Grab one of the fixed grippers and move it up and down. You should feel some movement but very very slight. Do the same with the spring loaded gripper. A bit more difficult to feel because you are moving a spring loaded gripper but if you move one up and down and with your other hand touch a different gripper, again you should feel very slight movement. Not a horribly expensive repair, probably just cam followers, internal bearings inside each of the 2 segments and maybe some gripper tips. Reset pretention, fixed gripper height and opening/closing times and you should see a major improvement.
     
  5. turbotom1052

    turbotom1052 Senior Member

    Joined:
    Oct 2008
    Messages:
    1,044
    Location:
    Vermont
    its not so much a matter of getting seized up as it a matter of getting worn out. Your supposed to return the compensator to its zero position once you've finished the job that you needed to use it for. This is the reason why I always taped myself a little note on my console as a reminder to return it to its zero position at the end of a job.
     
  6. exheidmech

    exheidmech Senior Member

    Joined:
    May 2009
    Messages:
    674
    Location:
    USA
    Its always a great idea to put the compensator back to zero however its extremely rare to see a pressman do that. It is always a set it and forget it thing. Only if there is an issue is it checked. However an issue with the compensator is not ususaly seen as an issue between units where there is a perfector.
     

  7. MRFIXIT

    MRFIXIT Senior Member

    Joined:
    Aug 2014
    Messages:
    43
    Location:
    U.K.
    HI..WHEN YOU SAY FIT PROBLEM I ASSUME IMAGE SIZE VARIATION, NOT MISRIGISTER..DOES THE PRESS REGISTER TWICE THROUGH ONLY USING UNITS 3 AND 4 OR 1 AND 2 ?
    THE MOVP PRESS WILL BE 2/2 - 4/0 CONFIGURATION..IS THE IMAGE OK AT THE FRONT OF THE SHEET? THE IMAGE SIZE CAN BE AFFECTED BY PLATE PACKINGS, BLANKET BACKINGS AND JACKET VARIATIONS, POOR PLATE CLAMPING..THE FIRST CYLINDER IS CHROME(NO JACKET), THE NEXT WILL BE EITHER STEEL OR BEADED PERFECTING JACKETS..I HAVE SEEN PRRINTERS USE DIFFERENT BRANDS OF JACKETS WHICH CAUSE IMAGE VARIATIONS BUT THEN REPLACED WITH THE SAME BRAND OF JACKETS ON ALL UNITS WITH NO PROBLEMS..
    IF THE PRESS IS MISREGISTERING THE IMAGE WILL MOVE BUT NOT CHANGE SIZE..
    ALL MULTI-COLOUR MO PRESSES SHOULD HAVE PAPER COMPENSATORS RETROFITTED BY HEIDELBERG BUT SOME DIDNT AS THE OWNER MAY NOT HAVE HAD ISSUES WITH PAPER STRETCH etc....
     
Loading...