2006 SM74 damaging the corners of 19x25 press sheets

[Albert Noel]

The press is a 2006 Speedmaster SM74. The press itself runs great and the feed seems bullet-proof, except this issue we seem to have on 19x25" sheets. It happens on all text weights (and happens less frequently on anything heavier then 80# gloss or 70# uncoated text) The corner of the sheet about a half inch in from either edge looks as thought it's catching on something at a very fine point and it either tugs the sheet enough to crease/wrinkle/double on the next sheet, or it just folds the corner over (assuming it is somehow hitting an indeed gripper either in the swing arm or the very first transfer drum)

We've checked, checked and checked again all the grippers as well as the front lays and headstops. everything seems to be functioning correctly and nothing seems broken or out of the ordinary. We have had several outside people look at it (two separate techs from Heidelberg, a demonstrator, and a third party tech) all who cannot figure it out. One of the Heidelberg techs claim something must be out of sorts or broken, the other claims that it is a design flaw in that particular year, the demonstrator says its just the way the paper is positioned (and to run everything off centre) and the third party tech thinks we need to replace the infeeed swing gripper.

I'm mostly just wondering if anyone else has experienced this before on their SM74 (2006 model or similar)

 

[aqazi81]

If you run off center, does this resolves the issue? And how much off center?

 

[Albert Noel]

If you run off center, does this resolves the issue? And how much off center?

A third party tech has also suggested this but we didn't try it as everything we print needs to be centred on the sheet.
Unless there is a setting i'm un aware of? (i've only run this press for 2 years, prior to that i ran a 300 manroland for 11 years and it was a much different infeed)

 

[aqazi81]

Run few sheets off center and see what happens. If sheets come good at delivery then there must be something wrong with your grippers or infeed. Can you post some pics of the damaged sheets?

 

[turbotom1052]

as mentioned i think that running off center will be worth trying. You could also try turning off the side guide and running the press up to speed to see if the dog ear goes away. This will confirm the need to run off center. May only need a slight amount off center to transport without dog ears and then center all colors with the lateral plate moves.

 

[Brer]

We have a 2006 PM74 and had the same problem. We were able to track it down to the front lays (head stops). They hit right on the corner of that size sheet. We were able to remove the two outside stops. One 10 mm bolt coming up through the bottom of the shaft they are on. Problem solved.

We run without them on everything now. No ill effects.

A few years later I kept getting wrinkled sheets and it turned out my Venturi blower was out. Make sure it is working.

Good luck.

 

[Albert Noel]

We have a 2006 PM74 and had the same problem. We were able to track it down to the front lays (head stops). They hit right on the corner of that size sheet. We were able to remove the two outside stops. One 10 mm bolt coming up through the bottom of the shaft they are on. Problem solved.

We run without them on everything now. No ill effects.

A few years later I kept getting wrinkled sheets and it turned out my Venturi blower was out. Make sure it is working.

Good luck.

I will have to look into both of these things and see what I can figure out. thanks for the info!

As for running off centre, I will have to look into really off-centring a few forms to see if that can be figured out if this doesn't work. The owner isn't keen on the idea.

 

[Albert Noel]

We have a 2006 PM74 and had the same problem. We were able to track it down to the front lays (head stops). They hit right on the corner of that size sheet. We were able to remove the two outside stops. One 10 mm bolt coming up through the bottom of the shaft they are on. Problem solved.

We run without them on everything now. No ill effects.

A few years later I kept getting wrinkled sheets and it turned out my Venturi blower was out. Make sure it is working.

Good luck.

I removed those two outside stops on my press and it immediately fixed the issue!
Thank you!!

 

[turbotom1052]

what commonly happens when this issue occurs is this.... Most all press manufacturers engineer their equipment for the world market. This would mean that standard publications world wide are set up to run certain size sheets. These sheets are sized to the metric system, and sized to these formats, that are based on the metric system. Now along comes the United States, with our out of sync with the world imperial system. Although we are a big market for all the European, and Japanese press manufacturers, we hardly warrant all the re tooling required for them to accommodate our antiquated measuring system. This is why a 19x25 sheet size might give you problems!!!

 

[turbotom1052]

I removed those two outside stops on my press and it immediately fixed the issue!
Thank you!!

What was happening is as follows.... Consistent with what I mentioned in an earlier post, a 19x25" sheet edge was "bumping" into the headstop covers when the side guide pulled it over. Multiple suggestions to run the job a bit off center would have accomplished an elimination of the dog eared gripper WITHOUT having to remove the headstop. The amount off center needed to clear the obstruction would have only needed to be a mm or 2.

 

[Mark777]

What was happening is as follows.... Consistent with what I mentioned in an earlier post, a 19x25" sheet edge was "bumping" into the headstop covers when the side guide pulled it over. Multiple suggestions to run the job a bit off center would have accomplished an elimination of the dog eared gripper WITHOUT having to remove the headstop. The amount off center needed to clear the obstruction would have only needed to be a mm or 2.

I seem to be only really having the issue when backing up running the near guide Is that consistent with other peoples issue Also it seems to be worse on 60 and 70lb silk stock