Slur issue Speedmaster 102 CD

I'm getting a small band of slur(1.5"wide) about 6" from the tail edge of the sheet that runs across the entire sheet. The Slur looks like it goes at an angle about 20 degrees. I checked the cams, they look good. I measured the blanket height and tried under/over packing and still slurred. I isolated the forms and they all get this slur. It is in the same place on every sheet. Did a run out on both blanket and plate cylinders, they are true. Its the 5th unit out of 6 plus a coater tower. I ran with no impression on units after this one and it is still there. I moved out of this unit and it went away. All form rollers are new. Any ideas?

 

Oh and this press is old, installed in 1998 I think..we do do a yearly maintenance on it.

 

Try turning off the ductor mid-run, see what happens.

 

Yes...I thought about this driving home...its the only other thing that happens in sync with the press revolution..thanks man! I'll try this on Monday..

 

have you checked the grippers on the questionable unit? Try liberally spraying the grippers with WD40 or some penetrating oil. across the entire width of the press and work the grippers individually to open and close them. You can usually do this with a large screwdriver. Sometimes they just get a bit sticky and will cause this issue. Be careful that you don't open them too far when you work them.

 

oscilation may be off on that unit