Parse error: syntax error, unexpected T_STRING in /home/printplanet/webapps/printplanet_php53/forums/includes/class_core.php(4606) : eval()'d code on line 10
Inline score and fold - Page 2

Page 2 of 3 FirstFirst 123 LastLast
Results 11 to 20 of 29
  1. #11
    Al Ferrari is offline Senior Member
    Join Date
    Jan 2008
    Posts
    1,226

    Default

    Hi John,

    I think most of us lock these set screws with the shafts positioned such that the collar set screws for both shafts are simultaneously facing us, thus creating high spots, no matter how small, that will face each other on every revolution. Would there be a significant improvement on the problem if we took the trouble to have ALL of the screws on one shaft facing 180 degree from the ones on the other shaft?

    Al

  2. #12
    ondemandbindery is offline Senior Member
    Join Date
    Mar 2008
    Posts
    312

    Default

    Here lies the problem with the set screw theory. Any slippage at all in the drive belts tied to the shafts and that theory goes out the window. So with that being said I will "give up" one of my secrets LOL. If you are having a splitting problem, lets make sure there is not a ratio problem with the collars on the shaft and the creasing device. If either one is running at a different RPM dynamic than the other you will get a tug O war or so to speak in the sheet. Now understand that this can adversely affect sheet control but sometimes you have to recognize the problem and work your way back. And for the record, the Stahl will create a more consistent platform for the creasing just because they are built like battleships. Did that help you out any?

    John Weaver

  3. #13
    Al Ferrari is offline Senior Member
    Join Date
    Jan 2008
    Posts
    1,226

    Default

    On my '82 Stahl 3 unit TF 56 machine all rollers and shafts are on a single gear train, so belt slippage and turn ratio problem analysis do not apply.

    Two days ago, I did have an occasional splitting problem scoring on the 2nd unit, but only for about an inch at the lead edge. It only happened on about 20 sheets on a 2400 run (conventional 59 mm steel blade against factory supplied grooved hard rubber collar).

    I was not able to catch it happening, but the split never walked more than that 1 inch into the spine of two different 16 page signatures, so think it may have been happening on the 3rd unit fold rollers, which I have not had time to check.

    My apologies to all for drifting a bit off topic.

    Al

  4. #14
    Al Ferrari is offline Senior Member
    Join Date
    Jan 2008
    Posts
    1,226

    Default

    Splitting problem solved. The grooved collar was not positioned so that the grove would be centered under the blade.

    Al

    [Edit] Plus, there was a bit of end play on that 2n unit lower shaft. This last explains why the split never walked into the stock more than a bit past the lead edge, since the lower collar would re-center itself with the allowed end play. This is an important lesson for all about this symptom and it's remedy.
    Last edited by Al Ferrari; 03-24-2011 at 06:47 PM.

  5. #15
    ben082010 is offline Junior Member
    Join Date
    Mar 2011
    Posts
    2

    Default

    Okay, so if I'm understanding this right I should be double checking the shafts and make sure they are rotating inline with one another? The tri creasers are the new version which have a set screw on one and the other is free wheelin. I'm running them on an MBO Navigator if that makes any difference to trouble shooting?

    Like I said before I don't expect it to run 100% on 80lb text, but I definitely expect it to be better than without them and not splitting the sheet. I have also checked with Technifold's Tech help and sent sheets down to them to try out also and they had the same problem. I have talked with another local bindery that I use once in a while who also has tri creasers but he doesn't run into this problem. Although he won't fill me in on his secrets - I can't really blame him. Thanks for all your help.

  6. #16
    TheProcessIStheproduct is offline Senior Member
    Join Date
    Aug 2009
    Posts
    191

    Default Tri_crease

    Talk to tri-creaser, the problem with thin sheets is you have to really crank pressure down to keep from twisting, but that much pressure will cause light stock to split so they have blue bands to replace the normal black ones that have a bigger OD so you can retain grip without splitting the sheet

  7. #17
    ondemandbindery is offline Senior Member
    Join Date
    Mar 2008
    Posts
    312

    Default

    Quote Originally Posted by Al Ferrari View Post
    Splitting problem solved. The grooved collar was not positioned so that the grove would be centered under the blade.

    Al

    [Edit] Plus, there was a bit of end play on that 2n unit lower shaft. This last explains why the split never walked into the stock more than a bit past the lead edge, since the lower collar would re-center itself with the allowed end play. This is an important lesson for all about this symptom and it's remedy.
    Hey Al, this thread is anything related to scoring. You said score in the second unit for a fold in the 3rd unit. What is your orientation on fold? I may have a quick tip for you.

  8. #18
    ondemandbindery is offline Senior Member
    Join Date
    Mar 2008
    Posts
    312

    Default

    Quote Originally Posted by ben082010 View Post
    Okay, so if I'm understanding this right I should be double checking the shafts and make sure they are rotating inline with one another? The tri creasers are the new version which have a set screw on one and the other is free wheelin. I'm running them on an MBO Navigator if that makes any difference to trouble shooting?

    Like I said before I don't expect it to run 100% on 80lb text, but I definitely expect it to be better than without them and not splitting the sheet. I have also checked with Technifold's Tech help and sent sheets down to them to try out also and they had the same problem. I have talked with another local bindery that I use once in a while who also has tri creasers but he doesn't run into this problem. Although he won't fill me in on his secrets - I can't really blame him. Thanks for all your help.
    Ok. you are running 35mm shafts which is more stable than say a 30mm. Great machine. The arguement about the new scoring systems with a free wheeling female is the overall diameter is very small and a weight reduction. It make sense really but I would have to take a whack at a couple of jobs to give a real opinion. How old is your machin and what is the condition of your knife shafts and the ends respectively? Here is another question. When you are processing the jobs, how close are you running your sheet in the production cycle (ie sheet gap)? As for the Bindery keeping his secrets close to his vest, I totally understand and I appreciate that you do also. Unfortunately though, you will find a solution. I tend to dance with this issue from time to time. I just lost a client over this as they wanted to know how I was processing something and I stood my ground. It is my time, efforts, and experience in the industry that earned me the right to out smart someone on a job.

  9. #19
    ondemandbindery is offline Senior Member
    Join Date
    Mar 2008
    Posts
    312

    Default

    Quote Originally Posted by TheProcessIStheproduct View Post
    Talk to tri-creaser, the problem with thin sheets is you have to really crank pressure down to keep from twisting, but that much pressure will cause light stock to split so they have blue bands to replace the normal black ones that have a bigger OD so you can retain grip without splitting the sheet
    I have run some tri-creaser and they make good stuff too. I could potentially see this working. This very well could help match the correct speed of the scoring collars and substrate. This was a trick we used when running the ultimate scoring systems on the main units years ago. And it has one flaw but for the price you can make some pretty scores with that setup.

  10. #20
    Al Ferrari is offline Senior Member
    Join Date
    Jan 2008
    Posts
    1,226

    Default

    Hi John,

    Max width on folder is 23", so 19 x 25 sheet runs with 19" lead edge and 25" side guide.

    19 x 25 was grain 25 (not the best, grain was against the spine).

    1st unit: 19 x 25 folds to 12.5 x 19, perf on exit.

    2nd unit: 12.5 x 19 folds to 9.5 x 12.5 score on exit (here is where the end play caused the splitting).

    3rd unit: 9.5 x 12.5 folds to 6.375 x 9.5, high folio lip.

    Is that enough info to earn a tip?

    Al
    Last edited by Al Ferrari; 03-25-2011 at 05:53 PM.


Page 2 of 3 FirstFirst 123 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Sponsors

Powered by vBadvanced CMPS v4.1.2