register between units

[SM74]

Running a Speedmaster 74, 2 colour I find there is about a half a mm difference from one side of the sheet to the other across the sheet between the two units. The press is about 12 years old. Any ideas?

 

[exheidmech]

is there a perfector on the press?

 

[NotAGooner]

Running a Speedmaster 74, 2 colour I find there is about a half a mm difference from one side of the sheet to the other across the sheet between the two units. The press is about 12 years old. Any ideas?

Is the paper long or short grain?

 

[SM74]

Yes it has a perfector. This happens on different types of paper. It becomes a problem on tight fitting jobs. Looking at it again the 2nd unit is printing approx .25mm shorter across the sheet.

 

[NotAGooner]

Yes it has a perfector. This happens on different types of paper. It becomes a problem on tight fitting jobs. Looking at it again the 2nd unit is printing approx .25mm shorter across the sheet.

Yeah but is the paper long or short grain?

If it's short, you're bound to get that problem, with long grain you can correct it by packing or unpacking, with short grain you're f***ed

Check grainage by tearing paper on both grains, whichever tears straightest is the grain

 

[exheidmech]

Since your press has a perfector it is possible that your movement is coming from the pincer bar. This is not going to be an easy fix. A few things to check would be, inch the press to a position where the pincer bar is up. check both the spring loaded gripper and fixed gripper for excess movemnt. A little movement is ok, just grab a gripper and move it up and down and do the same to the spring loaded side. you should be able to feel a little movement but not really be able to see it move alot. Also it is pretty easy to check gripper opening and closing times between storage drum and reversing drum. I would use a 1 inch wide strip of paper, the thin paper that comes between new plates works great. put the stip into a storage drum gripper and have someone turn the press until the gripper opens, write down this degree. Do the same with the reversing drum but have someone turn the press until the pincer bar closes on the sheet, write down this degree. The storage drum should be opening about 1.5 degrees after the pincer closes. As the pincer bar, cam followers and gear segments begin to wear this gripper overlap will change. If it gets really bad you will need to have your reversing drum rebuild, not a huge expense if you dont have to replace your pincer bar. Also make sure the cam followers on your impression cylinders and transfer cylinder are ok. SM74 cam followers are prone to wear out fast if not greased regularly.

 

[XFired]

Hi,I am an experierenced Press Operator (38yrs),the problem you are experiencing is common to the 2 Heidelberg Perfector Presses in our shop,we have a 2 Color and a 4 Color both with Perfectors,with some age and impressions under there belt.You can spend major money and get a Heidelberg Mechanic in to fix this problem,or,you can try my $1.00 bandaid solution that will help you're problem,I have used this method on both the 2 Color SM74,and a 4 Color GTO both with perfector units,neither press would fit the image side to side,and,it didn't matter if it was grain long or grain short,I'm sure you have the same problem regardless of the Grain direction,and yes,the stretch will be more pronounced on a grain short sheet,common sense,.. My Solution,.. Get a sheet of sandpaper,Mediun grit,attatch some double sided tape to the back side of the sandpaper,a good carpet 2 sided tape is what I use,cut strips approximately 1/4" to 5/16" wide the length of the sandpaper,then cut these strips into 3/8" to 1/2 " long pieces,the width of the lower pincer gripper,clean any grease or ink off the lower pincer gripper,remove the tape backing,and attatch a piece of sandpaper to only the lower gripper's of the pincer bar, 1 piece on each of the lower pincer grippers,by doing this,you build up the lower pincer gripper to be level with the Transfer Cylinder grippers at the time of Sheet transfer,so now, there is no longer any sheet distorsion at this transfer point,the sheet transfers flat,and the image width will now be the same on both printing units..If you don't feel comfortabe using sandpaper,try something else,Seems hard to believe,but,it works GREAT,The 4 Color Heidelberg was also fitted this way,previous to this,the 1st two units would not fit the last two units,my perfector is in the middle of the press on the 4 Color.A Heidelberg Mechanic may not like my Bandaid Solution, BUT, it does work,try it and get back to me,I only change the sandpaper pieces when the double sided tape becomes mushy and you can see the sandpaper pieces starting to move slightly,at that time,remove all the sandpaper pieces,clean the residue off,and install new sandpaper pieces,I even Perfect with the sandpaper there,and have had no problems....Experienced Pressman from Ontario,Canada

 

[exheidmech]

That is a very interesting idea you have there, and I must say I am a bit surprised to hear this suggestion from someone with 38 years of experience. While this may be ok for a temporary fix, what acutally needs to be done is not what I would call a very expensive fix, albiet more than a buck. Really all that I would do if I was the mechanic on side it install new cam followers which maybe 250 bucks and reset pretention, fixed gripper height, ensure correct gear lash and opening/closing times. All this might be 8 hours labor. A permanant high quality fix that will last for years to come not some backyard hillbilly way of fixing what is possibly a multi million dollar machine. I do have one question though, what is the theory behind using sandpaper since there is no pulling force on the sheet? Ive seen guys put carbide grippers on the perfector and for the life of me could never figure that one out.

 

[exheidmech]

I didnt say it could be fixed for 250 bucks, those might be the only required parts, but with labor your taking maybe 1500 bucks. In the case where you were quoted alot more than money, maybe yours did require a new pincer bar and segments. I just dont know that I would be proud of fixing my printing press with double sided tape and sandpapaer. That for sure is up there on the Homer Simpson scale. I bet the Heidelberg guys are still talking about that one.

 

[XFired]

Perfector Problems- Fit

LOL,I had a real good laugh with you're name references("Homer Simpson,Hillbilly Fix")Just trying to help a fellow Press Operator with his problem,I'm the 1st Press Operator in the 6 months that this thread has been posted to come up with a simple solution to the Man's problem in England....This is a Global Printing Forum...,And,yes,I'm proud to offer a simple solution to an expensive Press Issue.....Rather than talk about my simple solution,try it,then comment,we were quoted over $10,000.00 to fix this problem,my simple sandpaper solution has worked for me for more than 6 years,I have perfect fit on a 4 Color GTO,Kompacs with CTP,corner to corner,side to side,dot for dot,short or long grain stock....including full page reverse full Color Printing..The 4 Color GTO I operate is an older machine,the reference to a multi million dollar Press does not apply here,the 2 color SM74 now can actually fit a 2 color job,and we can now actually run Process work in REGISTER,prior to my simple solution,this was not possible,at least not with the job actually fitting,My 2 color Pressman will stand behind the result of this "Hillbilly Homer Simpson Fix"....If you don't feel comfortable using sandpaper,try something else....How about a few actual Pressman trying this and getting back to me??, Don't knock it till you try it.....
Ontario Printer...

 

[XFired]

Perfector Press - Fit issues

By the way,my thought to putting pieces of sandpaper on the lower gripper of the pincer bar,is to bring the pad height of the lower pincer gripper to the same height as the transfer drum at the time of sheet transfer,my pincer gripper height with the sandpaper on the lower pad,is now the same height as the transfer gripper at time of sheet transfer,depending on how far you're pincer gripper is out of time,you may need to use either a heavier or lighter weight of sandpaper to attain the proper height...If you're not comfortable using sandpaper,try something else..Hope this makes sense to you....Ontario Printer

 

[exheidmech]

Once again great idea. In fact you are going to need to put sandpaper on on the spring loaded gripper too very soon since the sandpaper is going to wear off any of the remaining urethane. You are better off using regular paper or better yet replace the cam followers. Just so you know, your fix is not a fix at all. Anytime you have your fixed gripper fall off like that, it is a sign that your cam followers are wearing out. Once that starts its only a matter of time before you need to replace the cam followers, or as you like to do, use tape. You will have to start using thicker and thicker pieces of tape until you finally destroy a cam follower which will likely happen at the worst possible time, when you are the busiest and absolutely have to get this job off. And, quite likey it will wipe out the cam along with it. This repair will then cost you tripple what it would have cost had you done it right the first time. Replacing a cam, especially a drive side cam is not easy and is very labor intensive. Probably 2 extra days of labor depending on machine type, and what you have on the drive side in the way that needs to be moved. Any shelving, railing, catwalk, side covers and oil need to be removed from the press. gears need to be pulled and cylinders need to be supported. Bearing housings need to be pulled and all this is just to get to the cam. So, I hope you can sleep well knowing that you could be costing your company thousands in avoidable expenses by using your $1 tape and sandpaper idea. it may not happen this week or this month or maybe not even this year, but mark my words it will happen. Good luck!

 

[XFired]

Where's the Original Poster?? You're right,it's not a fix,it's a solution to a Pincer Bar Gripper timing issue.. Update,the GTO 4 Color I operate has been running this way for 6 years now.If someone doesn't feel comfortable using sandpaper,try something else...
I have not had to add any thicker caliper sandpaper to compensate for any wear....According to you're cam follower theory,and my thoughts on this,it really should not matter if there's something on the gripper pad or not,if the cam follower was going to fail,it would have failed,with or without something on the gripper pads... from the 1st day I operated this press,the 1st 2 units would not fit with the front 2 printing units,I've had at least 3 mechainics in to check this problem out,we were told the cam follower was fine,they didn't seem to know how to retime the pincer bar without tearing the whole thing apart at great expense...this press was purchased used before my time there,so,I can't question why it wasn't fixed at the time of purchase,my fit is still 100%,after 6 years,I can sleep at night,try running a 4 color that cant fit a job if you really want a nightmare....They weren't going to spend the money to fix the press,and,something had to be done for me to continue to work there..2 Heidelberg Perfector Presses in our shop,both with the same problem...something with Heidelberg Perfector Presses is going on...Maybe you should be talking to the Engineers at Heidelberg about this..Ontario Printer

 

[exheidmech]

Where's the Original Poster?? You're right,it's not a fix,it's a temporary solution to a Pincer Bar Gripper timing issue.. Update,the GTO 4 Color I operate has been running this way for 6 years now.If someone doesn't feel comfortable using sandpaper,try something else...
I have not had to add any thicker caliper sandpaper to compensate for any wear....According to you're cam follower theory,and my thoughts on this,it really should not matter if there's something on the gripper pad or not,if the cam follower was going to fail,it would have failed,with or without something on the gripper pads... from the 1st day I operated this press,the 1st 2 units would not fit with the front 2 printing units,I've had at least 3 mechainics in to check this problem out,we were told the cam follower was fine,they didn't seem to know how to retime the pincer bar without tearing the whole thing apart at great expense...this press was purchased used before my time there,so,I can't question why it wasn't fixed at the time of purchase,my fit is still 100%,after 6 years,I can sleep at night,try running a 4 color that cant fit a job if you really want a nightmare....They weren't going to spend the money to fix the press,and,something had to be done for me to continue to work there..2 Heidelberg Perfector Presses in our shop,both with the same problem...something with Heidelberg Perfector Presses is going on...Maybe you should be talking to the Engineers at Heidelberg about this.......Pete

A couple of things in response to the quoted post. I think there is a bit of misunderstaning here. Your right, the tape and sandpaper is not going to cause the cam followers to fail. It is the tape and sanpaper that is hiding the fact that your cam followers could be failing. Cam followers on a perfector are quite different than on any other cylinder in the sense that they are located so far from the gripper tip. This means that very little wear on the cam follower can result in alot of fixed gripper fall off. So, even though they may feel ok that doesnt mean they are ok. Second thing is, If I had 3 mechanics come in my shop and none of them knew how to retime your perfector without great expense, none of them would be invited back into my print shop ever. Even if your cam followers are ok it is a pretty simple adjustment to reset fixed gripper height. There is a pin on the drive side gear that needs to be knocked out and the fixed gripper can be reset into the correct position. The hole where the pin was needs to be reamed and repinned. Readjust the grippers and thats it. On a GTO your talking no more than 4 hours and no parts needed. Worst case scenario is the cam followers need to be replaced which still in not a huge job on a GTO. The problem is that many mechanics, Heidelberg mechanics included, want to throw new parts at the machine, its easier, cleaner and you know that it will work. The fact is that there is really only two times that you need a new pincer bar, after a major crash, and if its plain old worn out. Ive seen pincer bars sustain pretty significant hits without major damage. Next time you have a guy in, ask him why you cant just replace cam followers and reset fixed gripper height. If he says you need a new pincer bar ask him to show you why. If any mechanic tells you you need a new pincer bar without pulling the old one out, he also would not be in my shop much longer. Unless the pincer bar is going to fall out of the machine, or frozen solid it is not likely you can tell its bad without pulling it out. As far as the design of the perfector goes, there are thousands of machines with this design. Even the new XL75 and XL105 have pretty much the same design.

 

[XFired]

Perfector Press Register

Hey Press Mechanic,I agree with what you're saying,I forwarded you're reply to the Boys in charge,they can make the call at there discretion,at least we have a solution to the Perfector problem without having to spend $10,000.00 plus...I Thank You...Ontario Printer

 

[dduthler]

pincer bar

I run a mo 4color with a perfecter. Stumbled upon this post recently. The pieces of sandpaper made sense to me. I also have issues with the first 2 units not fitting the last two. By stretching the plate on 3 and 4 and using the split tail clamp I could get sellable work. Decided to give this "fix" a try. Was nervous to use sandpaper so instead used pieces of 80# uncoated cover stock. Used super 77 spray mount to attach the pieces to the fixed gripper of the pincer bar. On the first job after the "fix'" I was made a believer. Night and day difference on the fit. Still have a slight fit issue with light weight stock. I think I will step up to 100# uncoated card and see what that does.
Great bandaid fix for an aging perfecter unit. Still not fixing it the right way, but its working so far. Have done a couple dozen jobs using this method and am very pleased with the results.
Had a mechanic rebuild the sheet compensator earlier this year and it made a huge diff on light weight stock. We purchased new cam followers and will have him back when finances allow to rebuild.

 

[SM102zpman]

Greetings. I am very happy to have found this forum some time ago when I was looking for information about a different problem. I'm the operator, and helper on a 240 which means I do everything including loading the stock, even if its boxed 24 point C1S. (The employee exercise program.) I returned to find the sandpaper idea, because I too have had a lot of trouble with fitting and bouncing between units. The press was crashed years before I inherited it. Its got chunks missing on the swing arm cylinder, and grippers missing on the swing arm but that’s not been too much of a problem most of the time. I have a job in process , 100000+ impressions , 2 colors which it looked I was going to be forced to run at 6500 IPH. I did all the routine prescribed maintenance and cleaning , and was still getting a noticeable, and worrisome doubling of image in the second unit, especially on the drive side. So I tried putting some heavy duty tape on the lower pincer grippers and viola , the bouncing was reduced to a fairly acceptable level. I'm running K at about 1.20, with bare minimum pressure in the second unit. The bouncing is still there , but its much less noticeable and it now even across the sheet. I just want to say thanks for the band-aide X-Fired. And thanks for your input too exheidmech. There might be something bad going on with the cam followers which my managers would definitely prefer knowing. At this point, I'm happy I wont be working through Thanksgiving, fingers crossed, print gods acknowledged.

 

[aqazi81]

We also used this method on our SM 72 for a long time....and when this fix stopped working then we replaced the cam followers....

 

[SM102zpman]

Talking to a Rapida105 with perfector guy the other day: he says something similar to this is SOP for the pincer gripper after the holding cylinder. Update to my situation: I only put tape on the driveside grippers on the first try, since thats where I saw the movement. The second day I taped them all, the movement was reduced significantly. I have another tight fitting , historically problematic job coming up. I think I'll try another layer all the way across. I will bring up the potential issue with the cam followers, or the timing, which ever it may be, but for now I'll take hillbilly

 

[aqazi81]

Try to use the upper layer of the blanket...strip it from the blanket and paste it....