We are re-working a 360 with chain delivery. It's a really nice press, but the sucker feet deliver the sheet too early for them to be grabbed by the impression cylinder gripper bar.

We cannot figure out how to get it in time. We are thinking we'll have to take the linkage arm loose on the operator's side, and try to rotate the sucker feet back to where they need to be to deliver to the gripper in time.

We are scared to change the timing of the cylinders because the sheet is fed into the chain delivery grippers in perfect time.

Anybody have any experience along these lines? Are we proceeding correctly?

Thanks for any help!!

Hello,

Yes you are in the right way,

When you will be sure that you find the right time, make a mark with a pin.
I´m not sure if this machine has a front lays, if it has it, be sure that the paper stop for 1 or 2 degrees before the gripper bar of the impresion cylinder take the paper.

I hope that it help you.

regards

The chain del gripper bars are missing the sheets right? It sounds like the chain gripper bars are out of time with the bottom cyl. Looking into the chain del on the non op side you'll see the large sprocket closest to the imp cyl that the del chain rides on. You'll see 3 allen bolts on the side. If you loosen the 3 bolts you can adjust the gripper bar closer or farther away from the cyl grippers. You can only move the adjustment like .250 or so it won't 360. Just tweak the bar a little closer to the imp cyl. Tighten the bolts and HAND FEED a sheet in to see if it grabs. If you go to far the bar can slap the cyl so be careful. Little at a time. This is a pretty common adjustment and something that can go out if the press had a good jam.

Or....

If the imp cyl is not grabbing the sheet but you need to tighten the buckle adjustment on the op side. This should be adjusted with light to heavy stock and env's. More with light stock and lees with heavy is the norm. But sometimes you'll need to squeeze it to get some heavy stock to feed well. Sometimes also the upper feed roller (the bar that has the black rubber wheels on it by the sucker feet) those wheels are glued to the bar and can come loose from age or abuse. In that case you'll need to replace the upper feed roller. Pretty easy to do if the pressman has some mech skills. Printers Parts or AB Dick (Presstech) sells them. Also double check the paper pile height. It it's too high the sucker feet can catch the tail of the sheet (11x17 and up mostly) and cause problems.

I had the same problem on my A.B. Dick 9870.
It drove me crazy. It is not always a simple adjustment, many times it is a part worn out thet needs to be replaced within the machine.
from the non operators side.
There are a few mechanisms that feed to that specific action and when the parts are worn out a quick fix to the core problem will save you alot of grief.
Hope this helps...