QMDI 46-4 press, Tone issue....

Discussion in 'DI Presses' started by Bill Borcicky, Aug 21, 2012.

  1. Bill Borcicky

    Bill Borcicky Senior Member

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    Let me explain my issue, If I start up in the morning I can usually run 2-3 buggies about 8-10,000 impressions before tone starts up. as the day goes on, I level out at about 2,000 impressions before the tone comes back. I wash off the blanket ,start back running and 2,000 imp. later, its back.( For the most part, Tone is usually just on the Black unit.)

    Things I have tried to fix this:
    check roller stripes - all good !
    change ink , new cans and tried different brands. - no difference
    change blankets , tried more packing / less packing - no difference
    bought / installed NEW ROLLERS- no difference
    cleaned gear teeth - no difference (tone always in same spot.)
    changed roller timing from 6 to 10 then to 2 O'clock...**** TONE MOVED****
    reset to origonal position.
    Built room around press with own airconditioner to maintain 70 deg.F -no diff.
    chiller ( works fine ) even tried flushing system completely out - no difference.

    One thing I noted out of the ordinary was the blanket does accumulate ink on it ( like the old offset presses do when you run a 60,000 run, not enough to mess up the image but enough to dirty up blanket ) this may not be relevant ??? or could be a different problem all together? my personal thinking its startch off the paper accumulating.

    now I'm open to ANY suggestions, I have about 3 hairs left on my head and I'm about to pull them out. I don't care how off the wall a suggestion might be, I'm sure there is something I'm overlooking. I've had this problem for a few months now.
     
  2. Bill Borcicky

    Bill Borcicky Senior Member

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    Is it possible that one of the oscilating rollers are bad? these are the only ones which are not replaced with a set of rollers...??
     
  3. mightyandy

    mightyandy Senior Member

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    We had bad toning on PU3 similar to how you described. When I placed my hand on the cooling connectors on the end of the oscillating rollers there was alot of excess vibration it didn't feel smooth at all. We resolved this issue by removing the cam the oscillating rollers ran in and then removing the large gearwheel. I believe there was 2x needle roller bearings one at back of the gearwheel and one on the front both of these needed replaced.

    Also because the press had been running this way for some time prior to us owning the press the gearwheel + 3 rollers on the end of the oscillating rollers needed replaced as the teeth were all wore to a point so we took this time to replace those components also.
     
  4. Bill Borcicky

    Bill Borcicky Senior Member

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    That will give me something to look at that I havent considered. Thanks!
     
  5. Paul Cavanaugh

    Paul Cavanaugh Senior Member

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    Does this happen on your second pass with the paper? If so it could be powder build up on the blanket wearing out the plate prematurely.

    Is the blanket over packed? This will also cause the plate to wear out prematurely.
     
  6. Bill Borcicky

    Bill Borcicky Senior Member

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    Good Question Paul ! The press does the same on first pass as well as second pass. That was one of the first things I checked, I failed to mention that , Sorry.
     
  7. Bill Borcicky

    Bill Borcicky Senior Member

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    mightyandy , we may have a winner here! I took the side covers off and checked for the vibration as you described....We have excessive vibration in one of the oscillator rollers. I had also noticed we have one roller jumping a little that makes contact with it. Thanks!!!!
     
  8. Tran5642

    Tran5642 New Member

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    Good morning all:

    I got the same problem as Bill. Run CMYK color 30,000 sheet fine with no blanket clean. 15 min later So mix my own ink from process to spot color 662 toning on all blankets & impression cylinder why??? using regular Toyo mixing inks & AT1000 (0.1 gram) any suggestion???
     
  9. Tomatron

    Tomatron Member

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    If the toning is showing up as a approx 2" band across the sheet and can also be seen on the blanket then it is form roller end-play. Just watch your form rollers at the bearing and see if the forms have side movement. It doesn't take much, maybe 1 or 2 mil. If your press doesn't have an adjustment to remove end play you will have to shim up 1 side of the roller.

    If it is the entire sheet that is toning then its either Room temp., Roller temp., or ink viscosity.
     
  10. Bill Borcicky

    Bill Borcicky Senior Member

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    Tomatron, you have another good suggestion. The tone is in one area across the sheet. Although I have been corrrecting several of the above mentioned and they each have been lighting the tone issue, the roller end play may be the final adjustment I need to make. We may just have had a combination of isues we needed to fix. Independantly each issue may not be a problem to become deeply conserned with, however combined they created a nightmare to solve.
    I want to thank everyone for their input !!!
     
  11. augustov

    augustov Senior Member

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    This happen to me... do you can check for the Icon "S" (Setup) and the icon the rigth side of Re-burn plate (is the arrow to up and rigth, i dont remeber the name) click here and in any the memory button M1, M2, M3, .... do more low value in each unit and check... i dont remeber very well the name, but this is a configuration when the machine run more faster this configuration put the stroke value more lowers automatic, this happen the machine with the time and speed the ink take more temperature and sqirry more ink between the ink key.... this happen... do and tell me...
     
  12. agapiospap

    agapiospap New Member

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    Greece
    I bought 5 months ago a used qmdi classic. Machine was a mess and I solved a lot of problems. But I have similar issue at same unit#2 and I can't fix it.
    On non printing area of plate, I don't see ink but I 'm finding light ink with my finger.
    On blanket and paper I can see toning.
    Room temperature is 20-22C (68-72F). Temperature of brass oscillators is max. 21-22, measurement with infrareds. The roller stripes on plate are good(3mm). 3rd roller is back. The roller stripes to oscillators are also good(4mm). Ball bearings are checked. Timing is 6,6,12,7. Blanket+undercut paper is 2,3mm(0,090"). Paper coated and uncoated.Chiller ok
    I want to mention that rollers are retread(reconstructed) and diameters are ok.

    I noticed that, only at one side, 1st roller is moving a little, front and back in every cycle when it meets the beginning of plate (after red security roll plate). The ball bearing of roller is between a turnable oval stop and the security clutch(which opens and removes the roller).See photo. Do I have to turn the stop until no play?

    Searching the spare part german book, I found pages D-89,D-91 called "inking control unit". Pages have photos with 3 springs both sides of all units. How do I know that they are setting ok? Where are they useful to? Is there any connection with my problem?

    Any help please...
    Issue01.JPG IMG_20200309_093825.jpg IMG_20200307_113013.jpg IMG_20200307_113302.jpg IMG_20200307_184841.jpg IMG_20200309_095738.jpg
     
  13. augustov

    augustov Senior Member

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    Setup strip ink roller, this is the big problem, third roller clean the excive ink... So is necessary recalibrate roller
     
  14. agapiospap

    agapiospap New Member

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    I correctly setup strip ink rollers several times with the same fail result. I fix 1st roller and now it is not moving front and back. My problem is reduced. But the only solution was the "printon" anti-tone paste mixing with the cyan ink. This paste makes miracles and no tone issue or other dirty lines on paper. But the real problem continues to exist when I'm not putting paste. I noticed that other blankets have tone but they don't transfer it on paper at all.

    What else can I check?

    Could someone explain me how they work and how can I adjust these springs? When machine starts to print, pressure is down via air valves and sprinrgs change their position because springs have connection with form rollers. Some are pressured,others are not.
     

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  15. augustov

    augustov Senior Member

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    This have a messeaure but used a caliper, well, this is a time, but not necessarily you make adjustments here, maybe is problematic of ink roller adjustments, also the tack is other problem, well the printon really make more tack also the ink get more thickness so is how the press stay very cold.... But considering the ink roller is not good setup, make a small stripe in all... At 1,5mm or 2 in all is fine... Belive me enough ink is bad but a lot ink very bad...
     
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