Stahl folder inconsistent folding

[Leedsprinter]

Hi John,
The great majority of jobs we fold are cross-grain. Maybe 8 or 9 out of 10 jobs. The weights are usually 130gsm or 170 gsm.
Thanks,
Peter

 

[ondemandbindery]

Ok. I should have asked a simple question at the beginning of this post. Here is what
I would like you to do. Take the a handful of sheets and cut them to 11x11. Set your folder up and run half the pile in one grain direction and the other half the other way. Report back but I believe you are about to see your issue right in front you when you do this. Do a simple Trifold.

John Weaver

 

[Leedsprinter]

From your 2:56 PM post it sounds as though your side guide use is not the problem.

Let's go on to the fold plates and rollers.

In addition to being set squarely in the machine, there are at least 3 concerns about the fold plates:

1. Each fold plate needs to have the paper stop set square to the witness marks on the top of the plate. Variations from this can be made to compensate from some other source of trouble, but should be returned to squareness at the start of each job set up.
2. Each fold plate needs to have the the lower part, called the pan, set square to the top part, and set at the middle of its range (unless there is particular reason to set it differently).
3. Each fold plate needs to have the spacing between the two halves even from side to side and front to back. this is accomplished with spacer washers.

These last two are often ignored by inexperienced operators.

Now the fold rollers:

1. Each fold roller gap needs to be set even from side to side with ONE sheet of stock in the gap sets without regard to the numbered collar position.
2. After this is done, the numbered collars can each be set to 0 without altering the gap setting itself. This "calibrates" the gap sets, which can now be used to set the gaps for the required number of stock thicknesses that will pass through that roller gap in the particular job.
3. In the case of uneven length legs from a prior fold, each gap should be set to the least number of stock thicknesses passing through that roller gap in the particular job, so as to achieve proper drive force into the next fold plate. This will result in a roller bounce for that gap, which is OK.

Post back to report if attention to these points does not result in an improved performance.

Al

Al
You mentioned checking the paper stop to the witness marks. I believe that both the top and bottom plates I am using are not level to the witness marks scribed on the plate. Do you know how to square them up on a Stahl? I can probably work it out but any guidance would be helpful.
Thanks,
Peter

 

[Al Ferrari]

I indicated where to find those in one of the pictures in my post. If your machine has them, it is pretty obvious how to use them.

Al

 

[Alois Senefelder]

Stahl Folder

Stahl Folder

Gentlemen,


I hope the PDF will be of help.



Regards, Alois

 

[Al Ferrari]

Alois,

Thank you for your well intentioned post, but in this particular case your pdf does not address the question raised by the OP in his post of 7:04 AM today. But the general comments in the first paragraph of that pdf are definitely applicable here.

Al

 

[MalcolmBliss]

I have an idea. Use an MBO. It has a narrower roller and the spiral rollers are perfect for consisten tension. As my trainer once said,"It's all in the rollers".
However I realize that you cannot scrap your folder and buy an MBO, but I would do it in a heartbeat, having the funds to do so. Stahl folders are inferior in many aspects of design. However, like everything, they do have their good points though they are few and far between.....
I have ran both and an MBO is a superior design, in almost every aspect. Oh sure, you have the owners who want that "all heidelberg shop", but as an operator of 20 years, i would trade 10 Stahls for one MBO.
This is, of course, my opinion.
If your fold is inconsistent, check for marred deflectors and pans, gouges in the fold rollers and work coming off the guide. These are basics but the problem can be much more than this. If you have zero-makeready plates, they too can be inconsisten. We have an "AmeriStahl" B20 and it came from the factory with these. We bought standard swing-down deflector plates to try and solve the problem of inconsistency as well as the machine eating perforated work and it was like a new folder. Except it still feeds like crap, a trait common to these machines. I've had a Heidelberg mechanic tell me to "get a better model", but my owner seems dead-set on owning pile fed machines only and I really hate these types of feeders because we have a Komori 5 color and it curls work like I've never seen. Pile feeders exaggerate this curl making it almost impossible to run a full load without manually defeating the curl which is a real time waster. But anyway, I hope I can help. Feel free to PM me if you'd like.

 

[Al Ferrari]

Hello Malcolm,

Please help us understand why spiral rollers are superior to segmented ones. Can you give a link, or other reference where this is actually explained, and not just claimed. I suspect that a spiral roller is more expensive to manufacture than a segmented one, but I have not learned why the additional investment is justified.

You state "Stahl folders are inferior in many aspects of design". Can you cite a few specific examples? I have never operated an MBO, but I am eager to know the specific reasons for your strong preference since you say you have experience with machines of both brands. Both companies make several types of feeders for their fold units, so it is important to compare only analogous designs.

Thanks,

Al

 

[RGPW17100]

Depending on how old your Stahl is here is how to zero in the newer ones. You move the fold plate up to the scribe marks. Loosen the knurled knob and move both the inner wheel and the outer wheel till the fold gates line up to both scribe marks. You then need an allen wrench to loosen one of the wheels. (cant remember if it is the inner or the outer one) move that wheel when it is loose to line up the mark on the the two wheels then tighten the set screw with the Allen wrench. The two wheels I refer to is the wheels that you use to adjust the fold gate. Hope this helps.

We had a Stahl folder for years we got for a song and a dance from a company that went out of business. It was like new. We took care of it real well. Changed out grease cans and took fold plates apart and cleaned them. Had a mechanic look at it every year when he did the hydrolics on our cutters. We were bought out by a bigger company who exclusively uses MBO. That stahl could be set up and out produce any of these MBO folders at any time. The quality of the scores and the folding was much better as well with the Stahl. It is what you are used to and how the machine is taken care of that counts in the end. I have heard the MBO Stahl wars before and it is usually someone bashing one that they have never used.

 

[ondemandbindery]

I have an idea. Use an MBO. It has a narrower roller and the spiral rollers are perfect for consisten tension. As my trainer once said,"It's all in the rollers".
However I realize that you cannot scrap your folder and buy an MBO, but I would do it in a heartbeat, having the funds to do so. Stahl folders are inferior in many aspects of design. However, like everything, they do have their good points though they are few and far between.....
I have ran both and an MBO is a superior design, in almost every aspect. Oh sure, you have the owners who want that "all heidelberg shop", but as an operator of 20 years, i would trade 10 Stahls for one MBO.
This is, of course, my opinion.
If your fold is inconsistent, check for marred deflectors and pans, gouges in the fold rollers and work coming off the guide. These are basics but the problem can be much more than this. If you have zero-makeready plates, they too can be inconsisten. We have an "AmeriStahl" B20 and it came from the factory with these. We bought standard swing-down deflector plates to try and solve the problem of inconsistency as well as the machine eating perforated work and it was like a new folder. Except it still feeds like crap, a trait common to these machines. I've had a Heidelberg mechanic tell me to "get a better model", but my owner seems dead-set on owning pile fed machines only and I really hate these types of feeders because we have a Komori 5 color and it curls work like I've never seen. Pile feeders exaggerate this curl making it almost impossible to run a full load without manually defeating the curl which is a real time waster. But anyway, I hope I can help. Feel free to PM me if you'd like.

Just go pick out huge direct mail companies and look at the Folder hardware. It will pretty much sum it up. If anyone has to stay on course with production numbers, it is those guys. But I have seen a Stahl out shine an MBO on a few occasions. But they are few and far between. I give a Stahl one thing. You can slam plywood through it if you can get it to feed LOL. As for the original topic of this thread, the OP got quiet. I think it is more of a folding orientation problem in reference to grain direction. Dunno.............

 

[MalcolmBliss]

Just go pick out huge direct mail companies and look at the Folder hardware. It will pretty much sum it up. If anyone has to stay on course with production numbers, it is those guys. But I have seen a Stahl out shine an MBO on a few occasions. But they are few and far between. I give a Stahl one thing. You can slam plywood through it if you can get it to feed LOL. As for the original topic of this thread, the OP got quiet. I think it is more of a folding orientation problem in reference to grain direction. Dunno.............

I would have to agree with you. Orientation is very important, no matter what weight and grain direction. I wonder if the rollers are out of parallel or just plain worn. But having ran just about everything out there, Vijuk, Baum, MBO, Stahl and yes, even a Cleveland.....I, as an operator, prefer MBO over all of them. They seem to be engineered with the operator in mind.
To answer the previous question, a spiral wound roller is superior for many reasons, the most important being surface grip with minimal marking and tracking. I take that back....the rollers are wound in opposing directions so the tension is far more consistent in the transfer of stock. It's like a "screw" on the paper, if you will. They hold the work centered with little effort and almost no slip provided the machine is kept up to par.
Oneman is right, you have a stahl with a tre-mat and they will feed well. The regular low end machines with the Baum style feeder are just plain frustrating.

Getting back to topic, set your rollers with the thinnest stock you have, we use 60# enamel. If they have been resurfaced then you'll need a steady drag through the bank for each roller setting. Just enough to pull it through. Heidelberg told us that these rollers "expand with centrifugal force" but you can believe that if you want. I set the rollers so they make a nice squeaking sound. Now some people say to use one sheet, I do the contrary, rip the sheet in half and set the drag even on both outer edges of the roller. You do this enough times and you'll see what I mean. Then, if you run into an inconsistency on narrower work, you can micro adjust the rollers without the fear of excessive wear. I hope that helps some and doesn't confuse

 

[Al Ferrari]

"To answer the previous question, a spiral wound roller is superior for many reasons, the most important being surface grip with minimal marking and tracking."

But that's the claim, not an explanation. You can believe that if you want, but I find it just a sales gimmick. They do look impressive, and since MBO is the only one with that until the patent runs out, it will continue to work for them.

But let's explore the oppositely wound corkscrews idea a bit here. The urethane surfaces have more traction on the paper than the steel surfaces. If not, then what's the point of having any of this material on the rollers at all? But do they have more traction than paper surfaces on other paper surfaces? Hmm... How do you suppose that plays out as the buckle forms and is gripped by the pair of fold rollers with one corkscrew stressing one of the two paper surfaces in one direction while the other paper surface gets stressed in the opposite direction by the other oppositely wound corkscrew? Hmm... Seems like that would make for wrinkling if not crocked folding on lighter stocks, no? But since that is not generally reported to be what happens, then maybe those oppositely wound urethane corkscrews don't have the superior holding power claimed for them. Hmm... Which is it going to be?

Food for thought.

Al

 

[MalcolmBliss]

If your tensions are correct and rollers are not worn in the center more than the edges, I have never experiences wrinkles on these machines, nor crooked folds. We used our 5 MBOs for pharmaceutical folding. Mind you they all had gluing systems and 3 of the 5 had crushers at the end of 2 to 3 right angles. We ran 40# enamels off a web press and I never had any such issues. Only if your glue was not mixed properly with water, would you get a wrinkle on the edge to be folded due to over-penetration of the compound.
Take it for what you want. It is no sales gimmick. They have superior grip and control is outstanding on thinner stocks. On thicker stocks, you use less tension so there's little chance of jams. It's not just the rollers that make them better, the plates are very precise and all come standard with micro adjustments.
Again, for pharmaceutical folding, an MBO cannot be beat. I would take them over a Vijuk, which is what most people favor for these types of production.
The MBO perfection uses no ball bearings on the guide, it has a vacuum assisted belt. So there are no bounce marks from the ball bearings on the work. Any folding is just about perfect.
I don't want to hijack someone's thread with discussions about manufacturers. I'm sorry for bringing it up. I just thought that my experience over 20 years with different machines could shed some light on the subject and give the operator other options if they get really frustrated with their machinery. Every so often, someone junks what they have and buys new out of frustration. I thought I'd give the author something to consider.
BTW, we do not currently have an MBO at my place of business now. We have a Stahl. After going to a trade show, the owner wishes he would have never made that decision to buy one. We've got a Baum with 18 years in it and it will run circles around that Stahl.

 

[Al Ferrari]

Malcolm,

I think you've missed the point that at this stage in this thread, the discussion between us is not about the machines, but about the explanation for why they work as well as they do. If you read my earlier message again you will, I hope, notice that I did not say that the MBO was a bad machine, or not the equal to a Stahl. And notice I said that the potential wrinkling and crocked folding is not what is generally reported for them. Your own experience confirms this, especially your experience with folding pharmaceutical inserts.

What I did ask for in response to your first message in this thread was an explanation of why the spiral roller works as well as it does. I still do not have it, and in the absence of it, I continue to consider it a very good marketing feature (i.e. gimmick). What is the flaw in the logic of my hypothetical argument that the opposing corkscrew urethane patterns on the rollers should lead to wrinkles or crooked folding? Again, I do not assert that this happens but that it should if the claim for the superior gripping power of these rollers with that pattern is true. What is the explanation?

It seems from your posts that you are not so much pro MBO as you are anti Stahlist (pun intended).

Al

 

[MalcolmBliss]

I don't want to hijack someone's thread with discussions about manufacturers. I'm sorry for bringing it up. I just thought that my experience over 20 years with different machines could shed some light on the subject and give the operator other options if they get really frustrated with their machinery. Every so often, someone junks what they have and buys new out of frustration. I thought I'd give the author something to consider.

Steel and rubber roller or urethane by the turn of the composition. Because the width of each section Design Differ. Some folding roll 30% of the surface area of rubber, and some 40% or 50% of the of rubber.
Combination of modular steel folding rollers and rubber rollers roll the merits of its grip and durability are better. But it also combines two shortcomings. When some began to wear rubber, grip weakened, indentation problem out. Folding roll updating and reloading costly and time-consuming.
MBO folding roll spiral pattern:
It the perfect combination of folding steel folding rollers and rubber rollers of the advantages, but also avoids the disadvantage of modular folding roller. Helical folding roller is MBO's exclusive patented design and manufacture of products. 70% of the rubber surface provides good grip for all types of paper, including the Bible for a class paper, special thin paper and glossy coated paper. Steel folding roller screw extended service life, but also to avoid creasing. Means to exert greater grip without too much pressure, which means less wear and tear, fewer wrinkles and less static electricity.
MBO helical fold superior grip roller shortened to determine the time and improve the folding speed and quality, will also be a waste to a minimum?? Words, increase production efficiency.
I'd also like to add, that in doing this for as many years as I have, I have preferred that machine that gives me minimal fuss and allows me to bang jobs through the shop. There are different makes of machines that do very well on certain jobs. However for general folding, a Stahl is a good machine, the older ones seem to be built better. Plus, Heidelberg seems to be able to shoot you a lower price on one pretty quickly, whereas MBO does not.

 

[ondemandbindery]

Ran a pallet feeder heidelberg years ago. And it would smoke down signature work, but the rollers were crap. That machine was not even 2 years old and the rollers were trashed. The design of the material was so that you ran you rollers "loose" and once everything got up to operating temps. the material would swell. Uhhh, yeah. Epic fail in my book. That design really locked the operator into go or blow mode during makeready.
The MBO roller is also easier to clean and the fact that you basically have more rubber on the substrate definitely makes a difference in static. The Pallet folder also had a vacuum guide and that belt has been replaced atleast 2 times since 2005. And Heidelberg over engineers the electronics with tricky screens and a bunch of "wow" selections. Never met an unhappy MBO owner but I can't say the same for the Stahl machines. But at the end of the day it all comes down to the operator. If you can run the pharmaceutical work I am pretty sure you have valid points if someone wants to debate you. On a side note, ever run a Vijuk? I was told they rule the small format folding.

John Weaver

 

[MalcolmBliss]

Oneman:
Vijuk is a fine machine. We just couldn't seem to get the numbers out of them that we did with MBO. To be honest, in my previous shop with 5 MBO's we did purchase a Vijuk for a smaller format job that was a steady. We sold it 3 months later. I never really found out why. When I ran it, it seemed to be up to par with the MBO's, but on a smaller format as you stated.
Stahl electronics are indeed grossly flawed with over engineering. I got 2 words for you. Long Sht.....
What the hell? Why would anyone need that type of detection? I phoned Heidelberg about a way to defeat that detection on the computer, but it is standard and cannot be over-ridden. Another reason to pull your hair out while running a folder....lol.

 

[Norm Gensel]

Leedsprinter,

I agree that the age of the machine should not affect quality of performance; the engineering has proven itself by virtue of the machine's longevity. Worn parts are certainly a common cause of folding and production problems.

John, Al, and others have offered some great advice but I would like to add to all of them. First, let me qualify myself. I am a technical specialist for Stahlfolder machines. I would be particularly interested in knowing the specific model and serial number of the machine so I can be more precise in answering your questions/issues. Until then, I can only generalize my answers.

The first issue I have is that the rollers were refinished; they are the business end of the machine, among other things! The consistent diameter of the "rubber" rings along the length of the roller is critical to maintaining control of the substrate, though I don't think that is the problem. I want to also tell you that the roller settings are important all the way through the paper path, regardless of the number of folds, just like on a printing press, the paper has to travel from one end to the other. You would do well by having the side guide replaced as well, there is most likely a groove worn into it as posted earlier.

Let's talk about roller "gaps" and witness marks. On a Stahlfolder, we call the roller caliper a Festa setting and one set of the witness marks are chiseled marks on the side rail of each and every fold plate. They can be found by looking at the side rail edge of the fold plate where the plate stop rests against the side-frame of the machine. There are additional marks that are scribed on the upper rails (the "ribs"), second one in, from either side, again, on each and every fold plate, to align the fold stops so they are parallel to the fold rollers. These marks will get you close, but the only way to accurately set them is by "blocking" the plates which requires a set of gauges. You should consider having one of our fine engineers from Heidelberg UK come in and give your machine a performance visit, you may be pleasantly surprised to breathe new life into your tired machine.

With regard to the question of paper weight...50# text is roughly equivalent to 75 gsm, keep in mind this value is based on "unprinted" stock. If you have full coverage or aqueous coating, it will affect the thickness of the substrate and consequently have an impact on the Festa setting value. The fold plate throat settings are adjustable, as Al stated. This adjustment is accomplished by using shims or if you look closely, there are set screws along each side rail of the plate that you can adjust for temporary positions.

When all is said and done, I would be curious to know what the relative humidity is in your shop. My thoughts and experiences make me think you may be having a problem with static electricity. The first step is to have the machine thoroughly checked by a trained and qualified engineer and then I would be more than happy to help you with any further issues.

Kind regards,

Norm

 

[Norm Gensel]

On another note, there are no "folder wars" here. I will answer the questions as best I can, but I will not bash any competitive manufacturer in the process.

Alas, the debate rages...who makes a better machine? Those of you who are debating...check the history of folding machines and see who came from where and what developed out of it...it is an interesting saga to be sure. Let's all work together and come up with an awesome solution, how about that?

 

[Al Ferrari]

Norm,

By any chance, do you know of a link or printed source that relates this history?

Al