Best practice for setting dampening roller pressure

[jeffrbauer]

I wanted to know if there is a standard method for setting the water rollers when prepping for a run. It would be good to hear from others, if there was a way to take out any variation from the procedure with different press operators and such. We rarely have to adjust the rollers during makeready so we're not in bad shape or anything.

Also I don't know if this is common, but each of our printing units are a little different when setting the water roller pressures (magenta especially). We have a Heidelberg CD 74.

Your feedback and comments are much appreciated. Thank you.

 

[Alois Senefelder]

Roller Setting

Roller Setting

Hello Jeff Bauer,

Read the PDFs I have posted on Pg 2 "Ink Flow and Roller Setting"


Regards, Alois

 

[JOHNYPRINT]

Hi jeff bauer
With regard to setting the damper rollers go by the press specification, but setting the rubber metering roller , this is what i do .using the pressure setting adjusters back the rubber roller away from the chrome roller until you get a puddle of damp running at each end then slowly bring the rubber into contact until the puddle on each end has just gone and then turn the pressure setting adjusters on half a turnboth sides.DONE.
Dont be too worried if the damp levels on each unit are a bit different thats just the way it is sometimes, magenta is always going to be the most unstable of the four process colours. make sure the rubber pan/metering rollers are in good condition if they need replacing put new bearings in the new roller aswell. if they are worn there will be a low spot about2~3inches in from the edge of the roller causing to much damp on that area of the plate but catch up on the edges, dont mess about get a new one in. also with hiedelbergs make sure the intermediate/link roller is set correctly and functioning correctly , especially on the magenta unit.
I'm sure i have written some things you already know but i hope there are some things that help.
regards johnyprint

 

[Bill Rothwell]

Bill Rothwell

Bill Rothwell

Hi Jeff, Here is how i set the pan roller in my heidelbergs. First I cut the water setting quit a bit in the consol on all units. Then I start the roller turning and slowly adjust setting on the gear side of the press until the flood is gone and then I do the same on the operators side, at this point I press the speed button on the unit to speed up the roller to maximum speed, this will show you if you have a low spot at running speeds(it's like how they spin balace your tires)while holding in the button make your final small adjustment to clear any low spots that you see. then I add 1 complete turn on each side and lock up the bolts. after I preink the press, I go up and look at each unit lead egde of the plate and check to see if the dryup is even I bring up the water a few increments to clear the dryup or make the proper adjustment if needed to whatever side until the dryup is even. Hope this is helpful, Bill Rothwell

 

[cheetoh]

One full turn after water stops breaking?? Seems like too much to Me. I have alway been trained by Heidelberg trainers to go 1/2 turn after water stops breaking.

 

[Bill Rothwell]

you are right, 1/2 turn is recomended, but I have found that if there is any low spots in my metering roller and I open a 1/4 turn it can cause flooding in that area of the low spot. So I close 1 turn and run my metering speeds slightly higher(due to tighter setting) and this gives me latitude if I have to open to balance my water without losing control. This works well for me, but I understand your concerns. I normally follow what heidelberg instuctors and mechanics have taught me to a "T", but this is what has served be best.
Hope this helps, Bill

 

[Mike Herndon]

you are right, 1/2 turn is recommended, but I have found that if there is any low spots in my metering roller and I open a 1/4 turn it can cause flooding in that area of the low spot. So I close 1 turn and run my metering speeds slightly higher(due to tighter setting) and this gives me latitude if I have to open to balance my water without losing control. This works well for me, but I understand your concerns. I normally follow what heidelberg instuctors and mechanics have taught me to a "T", but this is what has served be best.
Hope this helps, Bill

Whatever works each press is different. the main thing is to have everyone do it the SAME every time. Some of our older Heidelberg's needed one full turn due to the gear lash on the drive side and worn out adjustment collars. Our new press is only 1/2 turn then we lock them down. Make sure you lock them down, lots of guys don't and have problems. Every time the waters drop to the plate they will change if the 13mm is not locked. Heidelberg considers this the initial adjustment to get you started. Bill is right when he says to check the scum line on the lead edge of the plate after it inks up. That is really the only way to check to make sure the water pan roller to chrome is set right. I like to to watch the plate come clean. If it comes clean to quick or to slow on one side then that side is probably off.

Also, make sure the 6mm bolt that holds the water pan roller into the collar attached to the drive gear has blue or some sort of medium strength lock tight on it. It will get slightly loose and cause all kinds of weird problems.

Mike