4 roller crestline water unit

[snoozer]

Have a 4 roller crestline water system on a ab dick 375 , there are only three adjustments on this unit , tried to follow the instructions on the installation manual with no luck , am thinking the ends on the form might be a little swollen but still within acceptable range,having scumming problems , any ideas ? Thanks

 

[smalloffsetpressexperts]

What does the form stripe measure? The 3 adjustments are easy. They adjust the lift of form to change plates,
One adjusts the separation between the metering roll and form. One is for the form pressure.
The 4 unit Crestline's were known to lose parallel and scum. Drop the op handle to to lower crestline to plate and look at the stripe from metering to form

 

[nhprinter]

Honestly even if all of your adjustments seem to be ok, if the rollers are more than a couple of years old you should replace them. Crestlines are like that. No matter what you adjust you're going to have problems with older rollers.

 

[SteveSuffRIT]

Some ways to check roller pressure are:
Seeing light gap between rollers,
Tension on paper being pulled through nip point,
3 second delay then look at width of stripe on other inked rollers or form to plate.
Swollen roller will put more pressure at nip, reducing water, causing dry-up or catchup.

 

[smalloffsetpressexperts]

The metering roller is rubber also just a high durometer. Also the bearings fail in that roller. Also in the frames. Also the frames need to be squared when replacing rollers.