Density difference gripper to tail

[Mr komori]

Try changing your point of occillation, the ink is not being distributed the same front to back. Usually works.

 

[turbotom1052]

be aware that the setting being discussed here is not something you do one time and then its set for good. The need to adjust the point of oscillation can vary from job to job. The deviations you describe do seem way excessive. You can try to get the distribution balanced out with this setting but my thinking is that youve got something else wrong thats causing such a huge variation.

 

[kbarz]

cylinders

cylinders

if you are running an older machine, your problem could be your cylinder journals.. if press was running with to much pressure ,after a peroid of time journals will get egged shaped then you will print nice color on gripper,tail end,, but light in center of sheet.. kbarz

 

[Bloodsaler]

Maybe try to adjust the oscillator roller,let the highest density near the center of the sheet.
Previous months ago,We have this problem to,the same sheet will look a little different from the gripper to tail.
A germany engineer came to help us with our gripper mechanical problem,and he found this difference,help the operator adjust the oscilator roller,and the difference form gripper to tail is much smaller.
But for we didn`t have any colorbar on gripper part,so can`t tell you how the density changes,but from visual adjustment,the problem seems to be solved.

 

[Peter R]

Try Change your oscillation start point. Open the the door on the drive side and there should be the oscillation control arm. Stop the machine when it at its lowest point. Open the bolt and inch the machine roung halt a turn and lock up the bolt. See if that helps. The film of ink from head to tail is controlled by oscillation. You can even set it so you get more at the tail than the head. I used to a heidelberg data sheet to tell the diffrience for all the numbers marked on the oscillation wheel.

Terry

Not what it's called but correct area to adjust. Scale numbered 1 to 6 in red & white (Operator & Drive side). It will change ink density front to back of sheet. No difinative number to use for every job as the ink coverage on the job, type of ink etc will also influence heavily. Complicated to discribe & not used by 95% of printers. Check by testing on various settings.