Ryobi 512 advice urgently reqiured please.

Discussion in '1-Color and 2-Color Offset Presses' started by leon909, Jun 13, 2012.

  1. leon909

    leon909 Member

    Joined:
    Mar 2010
    Messages:
    13
    Location:
    Shepperton UK
    I really hope someone can help me before I loose what hair I have left!

    I purchased a 512 conventional damping ryobi 1998 with approx 18m impressions which is using bareback rollers but has not had the chrome roller changed to matt chrome. I am also using mega plates which I have used for years in a 3302 with varns with no problems. I just cant seem to get the damping working consistently and it's driving me crazy. If anyone has any advice I would really appreciate it. Things I have tried are as follows.

    I am using distilled water with ipp fount concentrate as the following levels

    1 litre distilled water.
    100ml alcohol. 10%
    30ml fount.

    New blankets and packing. New form rollers and bareback roller.

    I purchased a new bareback roller and set ink strip to 4mm to chrome osilationg roller and 3mm to plate. All new form rollers set 3.5mm to rislan osilating roller and 3mm to plate. The trouble is I get a washed out patterned image (looks like the sort of texture the bareback roller has) all over the sheet especially on the leading edge of any solids or scumming if I cut the fount back to far. Can anyone tell me if I have set the bareback rollers incorrectly or is it because it has the normal chrome rollers. Should I be able to print a reasonable job on this press. I used to part own a 522hx and 3302 and they were both great presses. I'm finding it hard to believe that this 512 is a load of rubbish and Im sure it must be something not set correctly but I have tried everything I can think of. In desperation I tried to mix just distilled water and 30% alcohol and that seemed to give a better result. Also tried presstek pink mega fount and it was even worse. Has anyone out there produced good work with clean tints and good solids on a 512 press and does anyone think I should buy the normal cloth covered form rollers and forget the bareback rollers?

    Thanks in advance for any info it really is very much appreciate.
     
  2. leon909

    leon909 Member

    Joined:
    Mar 2010
    Messages:
    13
    Location:
    Shepperton UK
    Have an engineer booked and will update the outcome in the hope it helps someone out there.
     
  3. ziggy33

    ziggy33 Senior Member

    Joined:
    Jul 2010
    Messages:
    451
    Location:
    Rice Lake WI
    Switch to metal plates won't have any problems stop fighting your water with poly plates huge waste of time and money. Everything you've mentioned points straight at your chemistry. I have a press repair business and 9 times out of 10 people running poly have chemistry issues
     

  4. Aprint Avist

    Aprint Avist Member

    Joined:
    Jul 2012
    Messages:
    11
    Location:
    India, Delhi
    I also have a 500N, and it had the same dampening problem. What I was doing is increasing the volume of fount. It was helping a little. But a month ago I changed the duck roller as well as some other rollers and found that the problem is nearly gone. Also overhauling in every year once is greatly necessary to every machines. The more the rollers get old the more the quality of printing worsens.
     
Loading...