Heidelberg Windmill Grippers Dragging on Corner of Platen
Hi all!
I’ve been having some mysterious bouncing issues. I think I’ve pinpointed it to the end of both the grippers dragging on the bottom left corner of the platen as they open. Only the end point after where the side guide pops up through them is making contact. It slips off the edge of the platen as it opens and slowly chews up the tympan sheet where it’s dragging. It doesn’t seem entirely consistent. Some jobs it’s run fine and others not so much.
The tympan is tight and not overpacked, I tend to run at the slowest speed too. I had someone come take a look last week and speeding it up seemed to help resolve the bouncing when we tested it with some rule. I was wondering if anyone else has seen this? It seems like the gripper isn’t getting entirely parallel to the platen before it opens to deliver the sheet.
I linked some videos I took.
Cycling the press by hand:
https://youtube.com/shorts/zW1aewBeoAg?si=uKGAiVydW6maFKdF
Running it in slow motion:
https://youtube.com/shorts/dPj_OjozKto?si=PI_aQVc64-Ctprt1
Thanks!
Dani
Edit: Added slo-mo video link
Another windmill user had a registration problem which turned out to be loose nuts holding the grippers. Also check to see if gripper bars are parallel with the platen. Easiest checked with the packing removed. I had one gripper clipping the top of the packing which I resoloved by shimming the gripper where is bolted on to level the gripper. Also check the head lay is not loose.
Good luck.