Heidelberg SM 102_4 lateral ghosting

Discussion in 'Heidelberg Printing Presses' started by asem alsafady, Jun 14, 2017.

  1. asem alsafady

    asem alsafady Member

    Joined:
    Mar 2016
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    Location:
    Amman Jordan
    Dear all
    I am facing a lateral ghosting problem in a SM102_4 machine. Model 2005. 86000000 impressions.
    My colour sequence is B C M Y.
    The problem appears sometimes at the beginning of production, and suddenly it disappears. Sometimes it appears after 1000_10000 impressions for 100_200 sheets, and suddenly it disappears.
    The problem appears at all speeds.
    When the problem appears i can see the ghosting on the black and cyan colours only U1&2.
    I did colour progressive, and the results were as follows:
    Black and cyan is OK.
    Black, cyan and magenta, the problem appears.
    Black, cyan and yellow is OK.
    For me the problem is exclusively after the impression cylinder of U2 (cyan) and the impression of U3 (magenta) I want a way to check the axial movement of the transfer cylinder 1&2 and the transfer drum.
    Note:
    I have checked the cam followers, the grippers and the timings, all are OK.
    I have checked the infeed. OK
    I have tried different types of paper with different sizes, and the problem is still appears.
    Please if anyone can help.
    Many thanks.
     

    Attached Files:

  2. junker1984

    junker1984 Senior Member

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    Appears to me, you have a bad thrust bearing at either your 3rd unit impression cylinder or 1st transfer cylinder. Straight lateral doubling, across complete image, is indicative of a worn thrust assembly or one in need of adjustment. There's really no tried and true way to simply check for lateral end play, you must physically inspect the thrust bearing set, replace if needed with proper adjusting procedure.
     
  3. exheidmech

    exheidmech Senior Member

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    The two photos you show really are not going to help us troubleshoot anything. We dont know if the the lateral movement you are seeing is on the lead edge or tail, on operator side or drive side. As already noted by junker, it could be thrust bearings. But for it to be thrust bearings we would want to know if you see it on the lead or tail, both sides or just one side. Also, its not uncommon for a machine with 86 million to need new grippers. Just because the gripper timing is ok doesnt mean the grippers are ok. Most likely your machine has urethane grippers, this wears off over time. Usually a good rule of thumb is 100 million but that depends alot on paper and solvent you use. Ive seen signs of gripper wear as low as 30 million. In addition, i dont really like to look at lines or characters for any kind of movement, its better to look at dots. Dots will show you diagonal movment as well and that is really what we want to see. Thrust bearings will produce a diagonal "ghost" as you call it, where a straight lateral move will come from the plate cylinder. With a little more info, i think we can help.
     
  4. asem alsafady

    asem alsafady Member

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    Ok, Exheidmech. The ghosting appears at all the sheet from the both lead and tail edges and on both DS and OS.
     
  5. asem alsafady

    asem alsafady Member

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    Ok, Exheidmech. The ghosting appears at all the sheet from the both lead and tail edges and on both DS and OS.
     
  6. asem alsafady

    asem alsafady Member

    Joined:
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    Location:
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    Hello everyone
    I would like to thank all of you.
    I solved the problem, there was an axial movement in the impression cylinders U2&3.
    I tied the ring nut of the impression cylinder, and tried printing, everything is perfect.
    Thanks a lot.
    Regards from hot Jordan
    Asem Issa
     
  7. exheidmech

    exheidmech Senior Member

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    Location:
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    Glad you got this issue fixed, thanks for the feedback
     

  8. asem alsafady

    asem alsafady Member

    Joined:
    Mar 2016
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    Location:
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