dampening roller chattering

[neversatisfied]

seem to be having dampening roller chattering on komori L528, on all units. dampening rollers were changed about 5 months ago. any suggestions?

 

[CKL]

What year machine? What kind of chatter? Is it ink crowding?

 

[neversatisfied]

Press is 2003, with komorimatic delta dampeners. The chattering looks like gear streaks that are visable on the blanket and of course on the printed sheet. The streaks run full lenght across the blanket. When running a dry solid they are not there. I am sorry but I don't know what ink crowding is, can you please explain to me? I looked in all my GATF books to try to find ink crowding but couldn't find anything. Thanks for replying.

 

[inky]

My DDS does this on longer runs. I just changed all the bearings as a matter of course, the supplier said it would make no difference and that the chattering was more likely to be emulsification. He was right, and the dampener still chatters. I'd love to know the cause.

 

[dana]

What are you running for setting in you dampener? also when setting the water metering to the chrome oscillator I like to make sure the metering is nice and cold. Do you get any feedback on the metering rollers?

 

[neversatisfied]

Dana, Thanks for your reply. Here are some settings and numbers i run dampeners. First of all my operators manual calls for 4mm form to plate, 4mm to oscillator, 3mm to metering roller, but on the 5th unit on the gear side there's a plate with roller settings on it. Oddly enough it calls for 5mm to plate,5mm to chrome, 4mm to metering. I've found manual settings work better. On pqc I run set at 14(early mourning), and end up about 16 to 18 depending on which unit at the end of the day. My ratios are 145. I use to have alot of trouble with feedback to metering roller but I finally got it under control. Occasionally a little on the ends of the roller with pms colors. I worked with a Prisco rep. on finding a fountain solution that worked better and we settled on questar 1 step. I run my fountain tank temp. at 60 degrees. The other press in the shop, a L628 has the same problem with chattering but that press has the ability to run intergrated and that takes care of it, but my press does'nt have that ability to run intergrated. Well I hope I answered your first question. I'm hoping someone out there has the solution to my problem. Thanks

 

[arfamoe]

Dont have a definitive solution but if BOTH your Komoris have suddenly developed the exact same problem i would think some detective work is in order.

 

[tkdieter]

We have a 1999 628 that has chattered from day one. We get around it by increasing the pressure between the water form and the chrome ossilator. It puts the teeth of the gears closer together which stops the chatter.