Problems with my MBO folder

[ptwysong]

Hi All
I've been having problems with my Mbo B30 trying to get it to make a strait score or perf. I know some of the tricks to making it straitin out but it's just a pain to alway fight wtih it everytime I have to score or perf something which I do a lot of. I'm wanting to know if anyone knows what causes it not to score or perf strait and how I can fix it
Thanks

[Al Ferrari]

How old is it?
Have you been operating this machine since it was new?
Was there a time when this problem was not the case?

Al

[ptwysong]

I have two folders that are doing the same thing. One is I believe a 80's modle and one is a 1990. they have not always been doing it. It started doing it about 4 years ago.

[ondemandbindery]

It all starts with sheet registration in the side guide. Before I would ask you about stock type, size, orientation for grain direction you have to make sure the sheet is consistent in the guide. Has this been a problem since you owned the machien?


John Weaver

[ptwysong]

I know the sheet is registering to the side guid. And it does it with any grain any size sheet I've scored anything from 24" to 6" and it's the same thing either way

[ptwysong]

And no it hasn't been doing it since we've had them.

[Al Ferrari]

If they are that old, the first thing that comes to mind of course is wear. Are the rollers all steel, or with composition segments? Is there ink build up on one side? But if the crookedness of score or perf is always in the same direction, then it is more likely one or more maladjusted deflectors after the fold. Also possibly the lower pan of the fold plate used in the fold may be crooked if the model allows for that. You say two machines are having the problem? Both in the same direction?

Are both machines the same size and model? If so, one way to pursue the cause is to exchange fold plates between them one by one. First set them both up as close as possible for the same fold and perf. Then try switching the fold plates from one to the other one at a time and carefully note any change in the results. Let us know what you find.

What did you mean by "and it's the same thing either way"?

Al

[ondemandbindery]

Ok. I am still asking about sheet registration. What is your marble orientation? In other words, what is the mix of steel and plastic and which marbles do you have at the end of the guide leading into the rollers? I ask about registration because this area is typically the major trouble maker on a folder. And there may be some other stuff going on as Al has said but lets get registration out of the way. Age of machine and how old is the guide belt?

John Weaver

[Al Ferrari]

Most folders even from the 60s have had an open slit on the last inch or so of the side guide so that the operator can see if the sheets hug the guide for their full length as they pass by. So that with even roller pressures on the first pair of rollers and a a guide set square to them, a "square sheet" should be seen to pass that viewing slit without "fishtailing".

As to the marble mix, that depends on the stiffness of the stock in the direction perpendicular to the side guide. I know most of you know this, but I am mentioning all this basic stuff just to get us all on the same page.

John is right that a badly worn belt can cause variation in the side guiding of the sheet.

Al

[ondemandbindery]

I have seen 4 major issues with problems that deal with side guide registration. Sheet not close enough to the guide prior to going into it. A groove in the side guide which is normal. A worn belt. And lastly the placement of the marbles in the guide. Too many steel marbles will cause a big problem especially when you have a major amount of them on the guide leading into the rollers. Al is right about the notch in the guide. Your sheet can even pull away from the guide and still create a quality fold but the key is the sheet consistently doing the same thing every time.

John Weaver