Registration problem

Discussion in '4-Color Offset Presses +' started by orainewolfe, Oct 13, 2010.

  1. orainewolfe

    orainewolfe Member

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    I'm new to the forum -I operate a print master gto 52-5 color perfecter 1 over 4
    i been having problem with the 2n unit at the perfecter its print shorter than the other unite -i check the packing with the packing gauge on all the unity n there OK.
    can someone tell WATS the problem. AN IT SHOW MORE ON 10PT BOARD THAN PAPER
     
  2. mqgpress

    mqgpress Senior Member

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    wolfe - What model year is the press? Did you buy it new? How many impressions are on it? My first suggestion to you would be to do a breakaway solid on the unit giving you the problem. Waters off, inker and impression on, starting with normal pressure and back off a few points each pull until you see the image breaking up - does it break evenly? If not, could be an issue with the refined jacket or bearer pressures, or cylinder issues (hope not). Good Luck, Steve
     
  3. turbotom1052

    turbotom1052 Senior Member

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    grain long paper or grain short?
     
  4. orainewolfe

    orainewolfe Member

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    The model year is 2002 and it was brought new, i been back tracking and realize that the cylinder jacket on that unit was change in last year when i begone to experience that problem and also the other unit three, four and five except the first unit was also change. could it be the jackets. because i ask the service personnel to check the bearer to bearer setting when the problem first arrive and he said it was OK-but when i print solid on that unit i found that i have over squeeze the pressure to get an good print. but not on all stock -that why i assume it was the quality of the stock causing that.
     
  5. exheidmech

    exheidmech Senior Member

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    How much is it not fitting by? Where did you get the jacket? How was the jacket installed. Its not uncommon for a GTO to have units that print a little long for shorts, maybe by the width of a line. Usually putting a piece of .001 packing under the impression jackets solves that problem. If it is more than that it could be that one of the cylinders in that unit are not running true anymore, maybe because of a jam. If this is the issue you will need to have the cylinder runout adjusted which can be tricky if you dont have the proper tools or havent done it before. If you are running non Heidelberg jackets, I have seen them rust under the jacket causing fit issues. Rust is a pain to clean of the impression cylinders. I have also seen jackets not installed correctly cause fit issues. You must use a pressing bar to install any jacket.
     
  6. orainewolfe

    orainewolfe Member

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    Yes-is an Heidelberg jackets and its install correct with the pressing bar at the edge, near the gripper. and also that unit has jam on the previous operator at the pincher gripper-but i rule that one out because it use to fit. i see the change when the new one where install. all the jackets where change except the chrome one at the first unit-because they worn out and burst-some of them in the middle. the fitting is not out by many as i said it show up more on 10pt board and up, paper its OK -

    the jackets or fairly new, not more than one year old- but what i do to make things work is to put a .002 under the third unit plate that is the red unit to reduce the image to fit with the blue which i think giving the problem that at the perfecter which printing shorter - because i use the first unit leave out the last unit at the deliver- cause the damper jump off if the fifth unit go off impression -i like to keep the damper on the plate in my make ready.

    I don't know if this will help but what i also notice is that-it fit from the tail of the unit-make it seems like the edges of the plate want to pull down to the grip


    I'm not familiar with the " cylinder runout" what it does or mean so i will let the service personnel checks that one out
     

  7. Technical_offset.pt

    Technical_offset.pt Member

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    good. I think you should do is:

    1. will have to have the leaves all the same pad measure, 1.05 +1.95 micons of rubber.

    2. make plates for all bodies with millimeter or checkerboard 5x5mm in the format 50x35.

    3. print one color at a time and check with the film over the print to see if it's in size. be that the size will be the master.

    Unit 3 as an example.

    4. then turn on the printing unit 3 and 2 and check if the registration is larger or smaller, if you have to larger enter a sheet calibrated under the plate cylinder printer, (the thickness depends on the difference).

    if you have toshorter remove .

    prcess after this will have to calibrate the clocks of the pressure.

    1. use a gloss paper 90 grs.

    2. alleviate the pressure

    3. put a printing unit at a time and go out to watch giving pressure to conduct a general fund.

    4. set the pointer to the 0

    and voila.

    I hope to have helped.

    F_ferreira
     
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