GTO 46 grippers are not catching the sheets after the impression drum drops them

our grippers are not catching the sheets after the impression drum drops them

I have had to reset the grippers from bottom of cam follower to machined surface on end of gripper bar is 30.5 mm.

they are set correctly but are opening too early and too short 2mm before the impression cylinder lets go of it

I cant find any one to help ???

any geniuses here in Adelaide who needs a little work ?

also we need a reliable printer - Casual hours

I am more management and IT with a strong mechanical background
Please help…. My knowledge is limited and I am desperate

 

A few things to look at, a jam up may have knocked the closing cam down, possibly changing the timing, chains may need re-tensioning or replacement, pins in gripper bar levers or sprocket shaft may be bent.

 

OK thanks you are a big help that gives me somewhere to look next - onto it now - where is the the closing cam ?
I an crawling all over the beast now... oh what fun

Just a few further questions, facing the end with the grippers - right-hand side there is a knob marked as "Gripper opening control" it is supposed to adjust the opening cam but it seems to just turn with no resistance (13 full turns) till the end of movement then firms up as though it is tightening and nothing changes ???

Also the press feeds paper on run when I start the press I believe it should not.. any Ideas, dose it matter as long as I know what it is going to do

 

Closing cam, looking into delivery, right hand side at the point the gripper bars start making the curve. Just follow the cam follower and you can't miss it. As for the gripper adjusting knob, you'll have to remove the OS cover and it should be clear what you need to do. Remove cover, turn knob and watch what the lead screw does...or doesn't do. Paper run, there are multiple contacts in the operating lever assembly, RUN DAMPS PAPER RUN IMPRESSION.
( I think...been a long time since I've seen a single 46!). Paper should not start until the third détente, maybe a bad switch. Good luck

 

Run problem - feed end left hand side white switch - "paper feed without Dampening control ..."
moved to left - problem solved

Grippers loosened and pushed forward towards the feed end
utilizing in the movement allowed for in the bolt holes
solved all the gripper problems as far as I can detect...

I will call in a printer now to check if work can be run now

Thanks heaps for all the assistance in here I was lost till you gave me direction...

Cheers Ray

 

Mmm just noticed the grippers are now leaving impressions and slight tears each side of where they grip ????
But they are gripping

 

By having to move the individual gripper bars to the end of adjustment on chain brackets leads me to believe you have problems with chain tensioning or worst case badly stretched/worn chains. Could e end be problems with the sprockets, but zprocket problems would be fairly easy for you to check, look closely at the teeth, you may have to clean with a wire brush or compressed air to make sure you aren't missing portions of the teeth. Also, if there's been a bad wrap up recently, the taper pins could be offset, causing arrival of bars to be off. This is all pretty major stuff, but has to be considered. Both bars nicking pretty close to the same? All the way across, or one side on!y?

 

HAVE YOU CHECKED THE DELIVERY GRIPPERS WITH A STEEL RULER ACROSS THE BAR AS THEY CAN EASILY BE BENT AND COULD BE SETTING THEM CORRECTLY IN THIS STATE..THE SHEET SHOULD LIE FLAT IN THE CYLINDERS AND WHEN ON MINIMUM GRIP THERE SHOULD BE ABOUT 4mm IN THE DELIVERY GRIPPERS(YOU CAN MARK THIS WITH A PEN ACCROSS THE TIPS ON EACH END..ALSO THE GRIPPER BARS SHOULD HAVE SHIMS ON EACH END TO SET THE GRIPPER PAD HEIGHT..THANKS..