Roller slurring

If the bottom roller hits the type that means it’s not rolling over the type; I would correct that first.
Are your gripper fingers in place? Your packing is tight, your stock is flat, not bowed?

Perhaps you have already checked some or all of these items, but this is what comes to mind. See if roller, truck, bearing assemblies are rotating freely and do the roller cores engage the trucks so that they turn as one?. Also, that the surface of trucks and rails are free of oil that might cause slipping and are free of any kind of buildup or deep wear. If you lay the chase on flat surface does the plate (or the forme you are using) lay flat or is the top portion raised? Sometimes old furniture or the chase itself can warp or accumulate dried ink. Could be simply an object on back of plate or on the bed of the press. Are you certain that the issue isn’t with the plate itself? You could try turning the plate 90 or 180 degrees, print a sheet and see what that tells you. Hope that you are able to resolve this issue quickly.

The printed result may not indicate a roller issue at all.

It looks like maybe the polymer plate is either overexposed or suffers from incomplete washout in some areas.

Orient the plate 90 degrees and 180 degrees and print it again. This should reveal where to look next to resolve your issue.

Michael

Thanks, shopmates; appreciate your experienced guidance, and very helpful indeed! Working on the problem and your advice is most welcome.

Ben

Another option is to check and make sure your platen is properly adjusted. If you’re striking heavier at top or bottom you can have similar results. Do you have a lollipop gauge? You can use it to adjust the platen.
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Michael Hurley
Titivilus Press
Memphis, TN