Dampening pnematic problem

[khouryabdo]

Hello

I a have an sm 52-2 . my ink and damping roller are totally new.
the setting of the rollers are as recommended by manual 100%.
I am having unstable ink water balance during printing. how can i know if it is a matter of air pneumatic problem.( compressor)

 

[turbotom1052]

are you able to stripe the dampening system the same, time after time?

 

[khouryabdo]

what do u mean by stripe the dampening roller?

 

[turbotom1052]

in order to check your dampening settings you need to actuated the pneumatics. When you do this the various rollers will make their contacts. For most of these rollers a visible ink STRIPE will be seen on the rollers showing just how much pressure is being applied through the pneumatic pistons. You would want to see the stripes even from side to side and the recommended thickness as per the manufacturer. If after doing this multiple times you were to notice the stripe thicknesses varying that may be indicative of a problem with your pneumatics.

 

[khouryabdo]

so i should put ink on the dampening rollers?
And then do the test stripe?
and between which roller exactly?

 

[turbotom1052]

not familiar with speedster 52 as I've only worked on larger format but the operators manual should spell it out for you. basically you want to inch the press until the plate cylinder gap is not under any of the rollers when they drop down. Then you want to drop the ink rollers. Only after dropping the ink rollers do you drop the dampeners. Then you view the visible ink stripe left on the plate from all the rollers both ink and dampening, adjusting as per spec until all 5 rollers are set. This will have the water form set properly. Always work from the plate back!!! Then you can begin setting the rest of the dampening system in the same way. Once they are all set you want to engage all of the rollers multiple times. If the rollers all engage with the same consistent stripe then at least you have a good idea that your pneumatics are working right. Pay particular attention to the bridge roller settings. inconsistent ink water balance can often be attributed to an incorrectly set bridge roller.

 

[khouryabdo]

One more thing just to tell you why i think i have a pneumatic problem
the water is always high so i am obliged to squeeze all the dampening roller in order to get rid from the exess water so i can get good printing. but i think that this setting will affect my rollers life time because it is very tight especially between chrome and damping form

 

[turbotom1052]

not only will it wear out rollers quicker but also gears, and hangers. When you say the water is high are you talking about the motor speed, or that the plate always seems too wet?

 

[khouryabdo]

after setting the dampening system as recomended by catalogue the get a very wet plate even the water speed is to low 10 or 15 . when i print i get too much water at first 200 sheets then suddently it begin scumming ( ink on non printable area).
so in order to resolve this problem i was obliged to squeeze the chrome to the dampening roller and the water pan in order to get rid of the exess water.
and then i should put the water speed to 70 % in order to keep the plate clean after these new settings

 

[turbotom1052]

both units?

 

[khouryabdo]

Yes the both units because i used the same roller settings on the both units and i change all the new rollers at the same time.
so basically i have the same problem on the both units on the first slightly more sever from the second

 

[turbotom1052]

i sent you a private message

 

[khouryabdo]

didnt get it yet :S
My email [email protected]

 

[turbotom1052]

wanted to know if you've got a mac computer running FaceTime or ichat?

 

[khouryabdo]

yes i have a mac computer but never used facetime

 

[aqazi81]

Are you adding alcohol and fountain solution to the water? What percentages?

 

[aqazi81]

Roller strips in the dampening system of SM52 should be...
4 to 5 mm between water form and distributor cylinder.
3 mm between intermediate and dampening form roller...
4 mm between metering roller and dampening form roller..
4 mm dampening form to the plate...

You should ink up the rollers with yellow or any light color and check the strips.
and one more question,
Are you running integrated or not?

 

[khouryabdo]

Yes sure Alcohol 10% and fountain solution 2.5%

 

[aqazi81]

Did you checked the roller strips as I have mentioned in the earlier post?
Do you run your intermediate roller engaged?
Do you measure your pH and conductivity? how often you change your water?

 

[khouryabdo]

No i will check the the roller strips today
and yes i am running integrated the application roller is engaged
what is the effect of the integrated mode and why is it used for?