Installing and setting rollers

Discussion in 'Komori Printing Presses' started by KGM, Jan 5, 2010.

  1. KGM

    KGM Senior Member

    Joined:
    Oct 2009
    Messages:
    131
    Location:
    Ireland
    I have never done this on my own but have to replace the rollers on my cyan unit tomorrow. Usually i have an engineer or another printer at least helping me.
    Ive seen it done and done it a few times helping out. I want to get it right myself. i can set most of them and make adjustments when necessary.
    Having problems with what i think is a distributor roller but after two attempts to fix it i came up blank. the ink is staying at the top of the train and i have to run it heavy to get the colour up and ink down the train.so i want to strip out the full set and measure and replace as i go. any tips for this???
    Its started with setting the form rollers to the plate i presume and then working up through the press. thats the plan. also do i add ink (yellow) as i go with each roller to check the strip width and transfer.
    any advice would be appreciated.

    Machine is a 4-col 1984 Komori Lithrone 26.
     
  2. KGM

    KGM Senior Member

    Joined:
    Oct 2009
    Messages:
    131
    Location:
    Ireland
    Well i got it done anyway, did two units. it was the pesky G and F distributor rollers causing all the trouble.

    Thanks for all the help too. ;)
     
  3. USAPressmen.com

    USAPressmen.com Senior Member

    Joined:
    Apr 2009
    Messages:
    62
    Location:
    florida
    lol no problem!
     
  4. RichardK

    RichardK Senior Member

    Joined:
    Aug 2007
    Messages:
    685
    Location:
    Derby, UK
    As I recall with that series of press just about every roller is a 'set' roller either by eccentric cams or by cap screws and pressure plates.

    It does pay dividends to make sure the rollers are within spec, ie not under size (they do tend to shrink over time, this can vary depending on the solvents used) and recheck settings from time to time.
     
  5. Loupeyeyed

    Loupeyeyed Senior Member

    Joined:
    Feb 2010
    Messages:
    110
    Location:
    jacksonville
    All rollers in that press can be striped immediately except for the ink forms and water forms. I'm glad that you got it done but are you sure that you set your ink and water forms correctly. You cannot set them to the plate first. You have to set the ink forms to the vibrator/oscillating rollers first and then set to plate. If you do not set them in this fashion you will have mechanical ghosting issues on some jobs. Ink Forms always have to be roller driven. If not, there will be a minute speed change in the roller rotation and you will also start to print with your water system vs. your ink train. Remember, 1-2mm tighter to the oscillator/vibrator than the plate and just the opposite for the water form. Set to chrome/oscillator first then come back to plate. It's very important to follow this sequence or you are not printing correctly.
     
  6. RichardK

    RichardK Senior Member

    Joined:
    Aug 2007
    Messages:
    685
    Location:
    Derby, UK
    This is good practice not just on Komoris but most other presses too. Also be sure to set as close as you can to the recommended stripe widths...they've been calculated for the optimum result across many different conditions.

    A small nugget of info that may not be common knowledge is that the standard set of rollers sold with Komoris are basically for process inks. If PMS colours are to be printed, particularly 'difficult' solids (greys, dark, greens, dark blues etc) with knocked out areas then there are optional rollers for this purpose.

    Oscillating forme rollers, softer composition rollers are all options that may or may not have been taken up at press purchase but can be retrofitted as required.
     
  7. Loupeyeyed

    Loupeyeyed Senior Member

    Joined:
    Feb 2010
    Messages:
    110
    Location:
    jacksonville
    Just curious Richard, does the D oscillator make that much of a difference on mechanical ghosting? I've heard the sweep is extremely short compared to the Rolands. Wanted them at one time but was talked out of it from a pressman at the shop who said they didn't make a difference.
     
  8. RichardK

    RichardK Senior Member

    Joined:
    Aug 2007
    Messages:
    685
    Location:
    Derby, UK
    Oscillating forme D on it's own won't make a huge difference but when you add the A oscillator most 'tricky' solids can be tamed, with much reduced repeat or ghost marks.

    Of course it almost goes without saying that if the rest of the roller pyramid is in poor condition or is out of 'set' then little effect will be noticed.

    The stroke is variable on these rollers but you're right when you say they don't oscillate as much as Rolands do...but then they optimised for Komori.

    I also have to admit we don't use them often as most of our work seems to run quite well without having to fit them - it's good to have them as a last resort though.
     
  9. Loupeyeyed

    Loupeyeyed Senior Member

    Joined:
    Feb 2010
    Messages:
    110
    Location:
    jacksonville
    Hmmmm, didn't know that A form had that option as well. I can correct most of the issues by communicating with pre-press and getting take off bars imaged where needed. It was like pulling teeth at first but now they understand the concept.
     

  10. turbotom1052

    turbotom1052 Senior Member

    Joined:
    Oct 2008
    Messages:
    1,044
    Location:
    Vermont
    try to get the roller train up to temp. before making final settings!!!
     
Loading...