ryobi 524 H Double image problem

[emmet]

Hello,

I am using a ryobi 524 H and i have a problem The black print is double imaging as it goes through the other units when i am printing heavier stock it does not happen as much but when i print 100 gsm, 115 gsm, 130 gsm or 170 gsm stock its quiet bad Hope someone has some suggestions,Thank you.

 

[Guest 82818-824]

Firstly, if you haven´t already, go through your cylinder packings and check the torque on blankets and plates. Also check you are not having any problems on your front and side lays. Check the height of your front lays and be sure your feeder wheels are not toutching the back edge of your sheet as it hits the front lays.

 

[emmet]

ryobi 534h double image problem

Thanks for the help will try this, now when i look a the machine i see some wear on the front side of the infeed drum i wonder if its catching the sheets at different times would this be the problem or if the grippers were not set properly as the double image seems to always be on the right hand side of the press.

 

[bluebeep]

Print is easy lol

[Sounds like grippers r the problem check gap on right side of press, this problem
also occurs when a blanket is old and glazed, or not cleaned properly.
the problem is definatley mechanicle.
Way to find out inch in to pressure and see if poss to catch the sheet
transfer
try stiffer ink this should amplfy problem and show more to track prob
Bluebeep

 

[emmet]

The problem does not happen if i run unit 1 + 2 on their own or units 3 + 4 on their own double image only occurs when all four units run together we run black in unit 1 and the double image occurs on the black image making type slurred would this be feeder gripper or transfer gripper setting.

 

[somma]

Dear Sir:

First, you must check all the blankets and plate are free of movement and check the overpressure of the grippers (print cylinder and tranfer cylinder), if these points are ok you have to check the follow:

The next coments happen in machines like yours with double diameter print cylinder with two systems of grippers bars, in your case the tranfer cylinder has triple diameter with three systems of grippers bars.

You said that you have doubling with color black (unit #1) , Is the doubling the same along the sheet?, if this happen you probably have a problem on the tranfer cylinder (you can see this issue at the next blanket after the transfer cylinder).
If the doubling is not the same along the sheet, you probably have a problem at the print cylinder (the gear wheel is not centered with the print cylinder and this cause a diference speed at the grippers bars of the firts print cylinder), you could check this issue if there is a diference of doubling between one sheet and the next one.

please give an update , I hope this is helpful for you.

Regards

 

[emmet]

had an engineer in to check gripper pressure its a bit better but not solved checked pressure settings and blanket packings wonder if its timing

 

[Lcegraphics.com]

Hello:
On a four color press like the Ryobi 524 several things can cause double imaging.
To diagnose you need to run just one color, the black unit by itself making sure that none of the other units are activated. Then inspect the image. If the image is blurred check with a magnifier and find out if the distortion is lenial or lateral.
If you are getting a lateral blur this can be caused by:
Defective bearings, Cylinders out of parallel, End play on cylinder from op to nonop side. This can be a worn cylinder hub retainer. Loose or squirming blanket.
Keep in mind that the balnket must be very strong to prevent squirming or rollout. This happens when the cylinder is rotating and the blanket stretches creating a tiny wave at the end of the cylinder rotation. This wave snaps back when the gap comes up creating a distorted or blurred image. Also check the back of the blankets to be sure the directional lines are running around the cylinder. The lines are printed on the back of the blanket to indicate the roll out direction of the blanket material.

Check the plate to blanket pressures and packing to insure that there is not too much pressure between the palte and balnkets. Also make sure that the impression is not too heavy.

Another cause of image distortion is gripper slipage. This is best seen when you are running mutiple colors. The blurr occurs when the sheet slips back after it leaves the first unit.

Worst case scenario is excess wear on helical plate skewing gears. Also some types of lenial compensating gears can cause a lenial (Around the cylinder) Blurr.

Hope this helps

Joe Castillo Lcegraphics.com