Heidelberg CD102 6col - Grip Issue

[CD102]

But the question again is, has anyone checked to make sure the front lays are correctly set and that the plate cylinders are at their zero point? There is something different between the two presses. Fix the press that is wrong.

[CD102]

One more thing to point out, sometimes the servo motors stop working for the front lays. I know that on the older presses, if they couldn't establish their zero points that the numbers would flash on the monitor. We always had ours set on 11,00 but there were times they would move or get moved and then they didn't get back to where they belonged because of dirt gumming up the works.

The same was true of infeed gripper height. It was supposed to be twice the sheet thickness. One crew went from .030" stock to .016" stock and couldn't figure out why the press was dropping sheets. They had set the numbers correctly for presetting, but the servos for setting the gripper height were stuck nearly wide open. The press crew didn't realize what it meant when the numbers were flashing.

[rbailleu]

yes that is a good point i idid not realize that you had 2 of the same press. one has got to be off. either they moved the zylinders or the grippers. otherwise you would need 2 workflows which would cause more issue as they would then be locked in to each press once the plates were made.

[jbeniston]

One more thing to point out, sometimes the servo motors stop working for the front lays. I know that on the older presses, if they couldn't establish their zero points that the numbers would flash on the monitor. We always had ours set on 11,00 but there were times they would move or get moved and then they didn't get back to where they belonged because of dirt gumming up the works.

The same was true of infeed gripper height. It was supposed to be twice the sheet thickness. One crew went from .030" stock to .016" stock and couldn't figure out why the press was dropping sheets. They had set the numbers correctly for presetting, but the servos for setting the gripper height were stuck nearly wide open. The press crew didn't realize what it meant when the numbers were flashing.

Sounds to me like you need a service call from HD. Print some dry solids with the settings at specs and measure the print free margin. On most presses the gripper bite and the gripper margin are different.
If you can stop the machine where you can access the impression cylinders with a sheet in the grippers, cut the sheet along the edge of the gripper, two at each end will do. Measure the distance from the sheeet edge to the cut marks when you get the sheet out of the machine. I do not know a whole lot about Heidelburgs but I would think that this measurement should be equal to the standard gripper bite considering that the front lays are properly set. The HD guy will be able to match the electrical setting of the front lays to the mechanical position,ifyou have a problem.
Hope this helps a bit.