How to improve OPOS accuracy on Summa D160R...

[MikeyG]

Hi there!
I'm printing a company logo onto 3-yr monomeric vinyl (using an HP latex L26500) and then cutting the vinyl to shape using a Summa D160R cutter.
I'm printing through Onyx 11 RIP and cutting with the Onyx Cut-Server.

The logo is being printed at about 450cm (18") wide, so it's not tiny.

However, the logo is a difficult shape to add bleed to (imagine something like two triangles on top of each other, one red one pointing upwards, the other yellow one pointing downwards).

No matter how I try I can't get the cutter to cut accurately enough so that where the two triangle intersect is where the two colours intersect!
I'm ending up with bits of the other colour projecting into areas it shouldn't be!

Am I missing something, or is the cutter just not able to be that accurate?

 

[gabagoo]

try slowing the cutter down. I have a d140 and I have cut lots of stuff without bleeds and if it is just a few logos, it generally cuts right on the line.

 

[letterman7]

By how much is the cut off? Mine generally cuts about 1mm off the desired contour. I put that to the vinyl actually either shrinking or stretching depending on the weather, regardless of how the targets are set up for registration. If it's a critical cut (most are not) I'll re-engineer the cut lines to fall into the areas that need attention. A little fiddly, but sometimes you have to do what you have to do. Did you do the setup and mapping for that particular media you're using?

 

[MikeyG]

By how much is the cut off? Mine generally cuts about 1mm off the desired contour. I put that to the vinyl actually either shrinking or stretching depending on the weather, regardless of how the targets are set up for registration. If it's a critical cut (most are not) I'll re-engineer the cut lines to fall into the areas that need attention. A little fiddly, but sometimes you have to do what you have to do. Did you do the setup and mapping for that particular media you're using?

Hi there
I always cut vinyl at 200mm/s. Speed isn't an issue for me.

The cut can be off by as much as 3mm, but more usually 1-2mm. Usually only in one plane, too. The vertical.

With almost everything I cut I print a bleed to allow for the inaccuracies, but with this particular logo bleed is very difficult to apply, and any amount of over/undercut shows big time!

I haven't done setup and mapping for the media – I'm not sure what you mean... Could you give me any more detail, please?

Very many thanks!

 

[letterman7]

Each media will react differently as it's pulled through the cutter, hence the misalignment. Usually you can map and calibrate the media by following these steps: www.[B]summa[/B].be/download/opos_en.pdf

 

[Summa]

Summa Contour Cut Compensation For Latex Distortion / Smile Effect / Warping

Hi MikeyG,

Are you using our OPOS XY feature? OPOS XY is an exclusive Summa feature that was developed specifically for HP Latex. The feature needs to be turned on within the Cutter Control software settings. If you are using our Winplot program or Onyx a registration bar will be added between the bottom registration marks and the cutter will scan the bar to compensate for the distortion that happens from time to time with HP Latex prints.

 

[FrankW]

Do you know how to calibrate the OPOS? It is an easy task, letting the cutter cut a rectangle out of black vinyl with a white backing, remove the cutted rectangle and let the OPOS-Senor scan the sample? 2mm off is too much, when talking about tolerances, I talk about 0.2mm regularly with OPOS.

In addition, with Onyx 11, you have the possibility to increase the number of markers used for your jobs ("Manage Cutters" in the file menu of the RIP-Queue-app) by reducing the markers max. distance. Using 6 or 8 markers instead of 4 (depending on the length of the print) will increase the accuracy too.

The OPOS XY as Summa have explained is a very good suggestion too, compensating the well-known bowing effect lots of wide printers curing with heat have.

And: how old is your plotter? Are the pinch rollers be inngood condition?

 

[MikeyG]

Hi MikeyG,

Are you using our OPOS XY feature? OPOS XY is an exclusive Summa feature that was developed specifically for HP Latex. The feature needs to be turned on within the Cutter Control software settings. If you are using our Winplot program or Onyx a registration bar will be added between the bottom registration marks and the cutter will scan the bar to compensate for the distortion that happens from time to time with HP Latex prints.

Hi there!
Thank you very much (to everyone!) for replying!
To answer some of the queries...
Both the printer and the cutter are brand new (less than two months)!
I always print with OPOS registration from Onyx.
I've calibrated the OPOS on the cutter.

One observation is that the media is displaying a lot of bowing when printing. I have tried adjusting for this using the "Straightness Optimisation" in Onyx. However, the bowing seems to vary from print to print, so when I try to allow for it, sometimes the print will be naturally straighter than others, so the bow will go the other way!

The vinyl is 100mic, and is being laminated with bog-standard 100mic gloss lam.

I'm going to run some simple square and circle tests along the width of the 3-year monomeric vinyl to see if I can lick this problem!

Any further advice or guidance would be greatly appreciated!
Thanks!

 

[FrankW]

OPOS XY is the functionality who compensates bowing.

 

[MikeyG]

OPOS XY is the functionality who compensates bowing.

How do I change the 'OPOS XY' settings? Do I do it on the cutter, or within Onyx RIP?

I'm getting really confused...!

Anguished cry in poor impression of the voice of Princess Leia... "Help me Summa, your my only hope!"

 

[Bly]

Hi MikeyG,
The feature needs to be turned on within the Cutter Control software settings. .

Or you can do it through the front panel.

 

[MikeyG]

OPOS cutting inaccuracy...

Hi MikeyG,

Are you using our OPOS XY feature? OPOS XY is an exclusive Summa feature that was developed specifically for HP Latex. The feature needs to be turned on within the Cutter Control software settings. If you are using our Winplot program or Onyx a registration bar will be added between the bottom registration marks and the cutter will scan the bar to compensate for the distortion that happens from time to time with HP Latex prints.

Hi there!
Thank you for replying to my problem of the inaccuracy of the OPOS cutting on my brand new D160R.
I have since run a load of test prints and cuts to see what is going on...

I have discovered that the media is bowing during the printing through the HP L26500 Latex printer. It doesn't seem to bow at a predictable amount, though.
I have tried using 'Straighten Optimisation' within the Onyx RIP to counteract it, which seems to have some positive effect, although it varies from print to print.
I have also 'Factory Reset' the cutter, just in case I'd messed with a setting I shouldn't have!

The result is that the top/bottom cutting of the print is much more accurate than before.
However, the left/right of the cut is off by nearly 1mm - starting a horizontal cut nearly 1mm into the left of the print and finishing nearly 1mm outside of the right-hand edge of the print. This is consistent throughout all of the prints!

Is there any way I can force the cutter to start a cut a fraction more to the left of the print. Is there an x/y setting I can tweak?

Very many thanks for the help! I really need it!!

Regards

Michael

 

[letterman7]

Through the OPOS setup on the console of the cutter (see the .pdf calibration above), you can manually enter the X value. Theoretically, the value should be the distance between markers, but if that distance is the same that the cutter is showing, then simply reduce the number by 1mm. It should work... but I have never personally tried it.

 

[Summa]

Hi there!
Thank you for replying to my problem of the inaccuracy of the OPOS cutting on my brand new D160R.
I have since run a load of test prints and cuts to see what is going on...

I have discovered that the media is bowing during the printing through the HP L26500 Latex printer. It doesn't seem to bow at a predictable amount, though.
I have tried using 'Straighten Optimisation' within the Onyx RIP to counteract it, which seems to have some positive effect, although it varies from print to print.
I have also 'Factory Reset' the cutter, just in case I'd messed with a setting I shouldn't have!

The result is that the top/bottom cutting of the print is much more accurate than before.
However, the left/right of the cut is off by nearly 1mm - starting a horizontal cut nearly 1mm into the left of the print and finishing nearly 1mm outside of the right-hand edge of the print. This is consistent throughout all of the prints!

Is there any way I can force the cutter to start a cut a fraction more to the left of the print. Is there an x/y setting I can tweak?

Very many thanks for the help! I really need it!!

Regards

Michael

Hi Michael,

Did you activate OPOS XY in Summa Cutter Control and in Onyx? Onyx will apply registration marks in each corner along with a registration bar between the bottom registration marks. The OPOS sensor will scan the bar to determine the scale and compensate for the bowing. I would refer you to our support staff but it appears you are in the UK, have you tried contacting your dealer for assistance?

 

[ProColorGraphics]

I have a S Class T-Series, but I have mine on "Force XY" and mine seems to work best running at around 400mm per second. I also will do an OPOS calibration with some black vinyl when I notice it is off a little. Most of the time I really don't need a bleed at all.

 

[Denamur]

I have a S Class T-Series, but I have mine on "Force XY" and mine seems to work best running at around 400mm per second. I also will do an OPOS calibration with some black vinyl when I notice it is off a little. Most of the time I really don't need a bleed at all.

Hi There,

How do you cut on black vinyl?
I just print on blue vinyl and my summa doesn't want to read the barcode and the squares....
Can you please help me?

Thanks a lot...

 

[AF]

How do you cut on black vinyl?

Load black vinyl and run the opos calibration from the front panel.

As for straightness optimization, if a material bows in the printer then the amount of bowing will be different at the start, middle and end. There are ways to add waste to the front and back of your print to even out the distortion so that your straightness optimization will work consistently. I have not used Onyx for a while so I cannot help you with that, but your 26500 has front panel options to assist with this. Onyx may also be introducing misalignment of your registration marks, and if so then there is nothing you can do to fix it.