Fighting spam in Discussion: new techniques

Windmill / Label stock registration issue

I’m setting up some labels to run. I’m using guides because the labels are round and will be die-cut afterwards. Movement is not good! I’m having trouble with the paper not keeping the impression in the same place (i.e. I’m running the stock back through the press to check registration and the print is slightly off). I’ve tested with some non-label stocks and have no issue, so I’m guessing it has do with the backing on the labels. I did test some other label stock I had sitting around and that didn’t have registration problems either, so I’m just not really sure how to resolve this.

I’ve seen references to using double-sided tape before, but can’t find them. Should I put a strip across the tympan to slow the sheet down? Could it be paper curl that’s causing it to sit slightly different each time?

Any help is appreciated!

Log in to reply   21 replies so far

Is the front edge of the paper stack in the feeder flat? Curl on the lead edge can make register fun (not). Label stock, with it’s attendant “sticky” edges, ought to be less likely to bounce off of guides than other stocks. Curl, which is another annoying aspect of some self-adhesive stocks, it more than likely the culprit.

curled paper causes printers to want to do 12 oz. curls.

What’s your solution to curl? Try curling in the opposite direction? I was thinking curl might be the culprit as well. Would a frisket finger help at all? I’m not sure I can use them because of how my art lays out across the plate, but just thinking of options. If I didn’t have 1,000 of these to run, I’d just put it on my Vandercook, but my arm might fall off!

So after running some more off and checking registration, it looks like the trailing edge is dropping behind the left lay guide. It’s not consistent, though, which is frustrating.

Any more suggestions? Or, even better, anyone in north Jersey want to come by and lend a hand?? I’m rapidly learning to hate this press, and I’d like to reverse that.

Not sure what you mean by dropping behind the guide exactly, but I have had issues with curl as well in the past. Particularly with large stock and printing the reverse side. The stock would miss the left guide and cause a registration or feeding problem. You can use a lay pin, but sometimes that is not an option when using photopolymer and a base.

I have corrected this by using a rectangular strip of Mylar stuck to the guide/gauge using two sided tape.

See attached photo. I have a small strip of clear tape as well… just makes getting the two sided tape off easier. You may need to use the really thin two sided tape in certain cases as the thick stuff may leave too much space. For the most part though I have found that you just need to hold the stop in place while the platen closes. This was used for an envelope job which can also cause issues that are similar.

You can also reverse the curl in the stock by hand as you suggested, but when you have a large job that can be tiresome.

image: Mylar strip

Mylar strip

Here are 3 images to show some more detail. I can’t get them to attach so I’m linking to them online.

Image 1: This shows the two marks left in the paper by the left hand lay pin.

Image 2 If I hold the sheet flat against the platen with the guides up, this is how it sits. This is in register, and the pin aligns to the bottom impression.

Image 3: If I align the pin with the top impression, the sheet slips between the lay guide and the platen, causing the sheet to twist just enough to be about 1 mm out of register.

I’ve tried gluing pieces of paper to the inner side of the guide to keep paper from sliding down, but it doesn’t seem to be working.

Am I making life harder using the nickel guides? I don’t own brass ones.

nickle guides can be a pain. do you have a little room to put a strip of paper on the bottom of the tympan to help keep the stock from slipping between the gauge and the tympan. Every 6 months or so i use nickle gauges, it always makes me remember why i like the brass ones so much.

I know that little metal nib (in Image 3, behind the lay pin) is supposed to go behind the sheet. Is there an adjustment (aside from pliers) for this? Obviously, the sheet is slipping behind it sometimes. Is there a timing mechanism that could be off between the lay bar and the platen closing? I’m just taking random shots in the wind here…

Do brass guides not have the problem with sheet slipping behind them? I’ve ordered a pair from Demers that I’ll have tomorrow.

you will not have that problem with brass guides, you can;t get as close to the edge of the paper but its well worth it.. For pins on the brass guides i use paper clips, just make sure they clear the type.

Thanks, Dick. I’m not worried about the paper margin for this one, fortunately. The biggest problem I seem to have with this press is fighting that stupid left nickel guide and getting the paper to sit on it correctly. I’m sure something else will come up now…

Might be a stab in the dark but you don’t happen to have a little polished steel guide which goes on the guide bar (not the lay bar, but the small bar behind it)? We use it when running the nickel lays as it guides the sheet down onto the nickel lays. I can’t see the part in the heidelberg parts book but the guide sits on part T0256. We can use our nickels in combination with this guide and the results are just as consistent as the brass lays so i’d say it could be the end to your dilemmas if you can dig one up.

so that’s what that thing is for, i will look thru my junk, i think i might have an extra.

I’m pretty sure I don’t have anything that goes on that bar, so if anyone has an extra, I’ll take it!

Page 58 of the manual! Its a slide spring. You might find it has been swallowed up by the platen so a bit of digging around in there and you might find it.

jonsel, i have down sized my spare parts for my windmills, i know i hav no extra gauge pins but this slide spring i just might have a spare, give me a couple of days to locate it and if i have a spare its yours.

I had to die cut 10 up labels from 80 gloss text stock and the nature of the die required me to run nickle guides with a snap on die-cutting jacket. To keep the sheet from getting between the jacket and the guides (not falling outside of the guides) I taped a couple little folded squares of paper to the left of each guide (when looking down at the open platen). The paper is only 1/4” x 3/4”, creating a little 1/4” x 3/8” tab that’s held on with tape. I did not have any problem with the gripper arm trying to strip the tab off and it resolved the bulk of my register issues (the others related to curl).

I’ll will try to post a photo in the next couple of days to better explain what I did.

Brass Guides for the win. Thanks guys. Totally solved my issue with the first run. Now on to the other plates.

One more question: which is the right guide and which is the left? The photos in the parts book are rather miniscule.

image: brass.jpg

brass.jpg

the one with the pin in the center is the right guide, it has a lip on both sides, mine doesn’t have holes for a pin.

Does the right guide need to be all the way on the right, similar to the nickel guide’s placement?

flat top goes left of centre the ridged one goes on the right of the height adjuster on right hand side. Always check before running that the lays clear the protrusions on the lower portion of the cutting plate , it can be an annoting oversight !