Hi all, im having a few quality control issues on the press.
I always have large inconsistencies in print length, which manifests itself at the last print unit.
I have the colour order C-M-Y-K. This is due to the type of work we do, it means 50% less washups.
The plates are still manually made, from film created on site.
By the timei lay down the black, its frequently 1mm or more too long. So i reduce the plate tension, (slacken bolts) to get it to fit, however it seldom does, and reversings look fuzzed.
The press is an older stlye Speedmaster 102. Conventional damping. I have calibrated the packings to 0.05 squeeze. (dot gain issues as well - my 40% C was 72 last time i measured)
So - Im aware that the paper is a factor, with distortion, and water uptake due to the old style dampers. Also the tack of the ink perhaps?
I had the idea of repacking the last unit plate cylinder to .2 under, and packing the blanket to the corresponding .2 over. Is this likely to effect a change?
The other option is to overpack the cyan and magenta - but with the gain issues i really dont want to do that.
Any ideas or suggestions much appreciated.
I always have large inconsistencies in print length, which manifests itself at the last print unit.
I have the colour order C-M-Y-K. This is due to the type of work we do, it means 50% less washups.
The plates are still manually made, from film created on site.
By the timei lay down the black, its frequently 1mm or more too long. So i reduce the plate tension, (slacken bolts) to get it to fit, however it seldom does, and reversings look fuzzed.
The press is an older stlye Speedmaster 102. Conventional damping. I have calibrated the packings to 0.05 squeeze. (dot gain issues as well - my 40% C was 72 last time i measured)
So - Im aware that the paper is a factor, with distortion, and water uptake due to the old style dampers. Also the tack of the ink perhaps?
I had the idea of repacking the last unit plate cylinder to .2 under, and packing the blanket to the corresponding .2 over. Is this likely to effect a change?
The other option is to overpack the cyan and magenta - but with the gain issues i really dont want to do that.
Any ideas or suggestions much appreciated.