Heidelberg Windmill Gripper Issue

Windmill grippers do get bent and sometimes you have to push up on them and sometimes down this can correct bite anomalies but you can rotate the platen so the gripper bars cross the platen at about 45 degrees and, with no packing slide about 7points under them from end to end with little/no resistance. too much room, bend down not enough, bend up. The 1/4” bite is a lot though , so it may be that the 2 bolts which can be loosed to allow changing straightness of feed table front (T1201) are loose. They should always be tight.
Stuart

I’m having the same problem only one of my grippers is picking the sheet up straight and fully into the gripper and the other gripper is not fully straight with the edge of the sheet. This causes the left edge of the sheet to get knocked off the sucker feet sometimes. I guess what I’m saying is, that the two grippers are not perfectly parallel with each other. Is there an independent adgustment for each gripper?

I’m having a very similar problem. When i watched closely, I noticed that when one of my grippers snapped shut, it forced out the paper on the left side. So it grips the right side of the paper, but the left (bottom) edge gets knocked out of the gripper arm. this only happens with one of my arms. I can’t figure out what is making it pop back out when the gripper closes on the paper. I ran a dryer sheet all over the gripper in case it was some kind of static thing, but that didn’t help.

This is a common problem , if you have been printing self adhesive labels the glue builds up in the grippers waterand white spirit gets that off. As mentioned bent or twisted grippers will cause this as well asplay in the windmill assembly . take the platen up till its 90% closed (gripper points up/down) engage the safety guard, so you are safe to do this bit without too much force try to make the gripper arms rotate and with a gentle push and pull you will feel if there is rotational movement if there is you need to replacethe dogs /pawls or the springs that aid them inside the drive shell at the top of the platen. its not a difficult job, you could look carefully at the sucker bar too and make sure its not bent . the worst pig can be the dwell time on the vacuum to sucker bar . does the suctionrelease cam look really worn andthe valve only open a little ? If so adjust the timing to open the valve a little earlier only a small adjusment is usually necessary, itseasier to locate the problem if you are the full time operator andknow the terms i use . !

if you run with the sidelay right in you will always get a dent at the edge of the sheet regardless most minders try to leave it in the middle and only screw it in a few thou , you get bad lays if you screw it right out sometimes too .