Vertical banding on radial gradients

[tsgstl]

Valuejet 1204
Flexi rip, flexi created gradient
I'm printing a large half crescent shape and I keep getting vertical banding. outside reflux blue fading to white. Have done alignment and nozzle check and most test prints for that matter all check out. The lines are almost pink to purplish in color. Not hugely noticeable but enough that a customer might complain. I never see these lines show up in any other prints only large gradients to white (I assume the less ink laid down in a large area makes them visible) solids and photos look great. These are 6' tall and fairly fat areas. Cleaned the tracks today thinking it might be because they were dirty (possibly stuttering) I plan on doing to calibrate my “Page Feed” tomorrow unless someone has a better idea. Photo of problem doesn't show very well. But it's bad enough to force me to not nest the panels (smaller top piece can't be rotated 45 degree to nest) I think the vertical banding going to 45 degree banding would make it more noticeable. Spent way to much time chasing my tail on this one.

 

[tsgstl]

Bump before I rip my hair out. Wife's birthday today, I need a mood changer.

 

[J Hill Designs]

rasterize it

 

[tsgstl]

tried that full size with a jpg?
it did really goofy things with the gradient.

 

[J Hill Designs]

export as pdf, pull open in photoshop, export as tiff, drop in prod mgr?

 

[HulkSmash]

flexi has a issue with gradients... open it directly into production manager rather then sending it from flexi.. if you made it in flexi...then flatten it in photoshop.

 

[tsgstl]

I am getting ready to do what both of you suggested.
I have had 3 customers come in and keep me from trying it yet. Sometimes I just want to lock the doors and turn off my phone.
I hope you are both right but I have a bad feeling it is a Mutoh problem. If I do different gradients or move them around the lines line up.
thank you

 

[tsgstl]

same results

brought a better cam in, you can kind of make them out.

 

[HulkSmash]

designed in flexi?

 

[tsgstl]

yes
this pic was from the one I:
exported from flexi PDF
imported pdf in photoshop
exported as tif
imported in production manager

 

[randya]

Try printing at a slower speed. i.e. next step up resolution or mode wise.

Might also try a different wave form.

 

[tsgstl]

Try printing at a slower speed. i.e. next step up resolution or mode wise.

Might also try a different wave form.

already tried both

I also put alcohol on the tracks. Never done that before, they were filthy and my brother in law said on his Roland they wipe it with a grease cloth afterwards? Is this something I should do?

 

[randya]

already tried both

I also put alcohol on the tracks. Never done that before, they were filthy and my brother in law said on his Roland they wipe it with a grease cloth afterwards? Is this something I should do?

Mutoh dealers have a recommended grease, you will want a not hardening type, put on very thin.

ftp://ftp.mutoh.com/Printer Informa...ins/MAI Bulleting_021709 Bearing Raceways.pdf

You can use a light machine oil, in the meantime.
Something sewing machine oil or 3in1.

Try and clean the bearings as well.

 

[tsgstl]

Thanks a bunch man ideally appreciate the hall on this site

 

[tsgstl]

after playing with just about every setting I said screw it, it is what it is. Started printing and now no banding. I would assume either a fluke or that it is warmer and more humid today. I'll stay here all night until its printed.

Thanks for all the advice/help
and if anyone finds this thread I would suggest reading this thread bellow
http://www.signs101.com/forums/archive/index.php/t-42172.html

I learned a lot from it

 

[tsgstl]

Not sure if this is related but. Everything print great for 3 hours. Then it started shifting. Like the print started moving over the width of one wave. Then it started printing random horizontal black lines over the entire width of the roll. I stoped the print (almost solid blue) and printed 4 cmyk boxes. Same random grey lines on top of the boxes. Turn the printer off and print the test color chart through the Mutoh menu. Printed fine. Went home and drank beer.

I don't expect sympathy because I know we have all been here. But damn it sucks when things aren't working right.



I will add. Production manager keeps freezing and going reeeeaaalll slow.
4'x5' sections of blue gradient to lighter blue, no mask.

 

[ForgeInc]

We had a similar problem drove me nuts for months trying to alleviate it. FInaly realized it was our onyx rip. It doesn't do gradients well without banding.

Switched to caldera and never had the same problem. Not sure if yours is the rip too but you could always try the same file in a different rip if you know someone or something.

Another fix not sure if you tried or not is to do the gradient in photoshop and add a slight bit of noise, 2-5%. This always helps too.

 

[alexcim]

I get these same bands (perpendicular to the print head movement) in light colours like pinks, blues, creams, and yellows.

I also use ONYX and am thinking that it's the RIP. The blue for example is just a light light blue 15/1/1/0 and you can see magenta "banding" through it. It's super odd.

Did you ever get to the bottom of this?

 

[unmateria]

Without a photo is difficult to say... Just make sure you are using your colour profile with perceptual rendering intent or try in another material or a new roll. Usually is one of both. Adjust vacumm to to make sure the material is completely flat, and store your rolls horizontal holded from inside of the roll

 

[alexcim]

How would I enable perpetual rendering in Onyx? I mean, exactly what is that feature?

Anyway, here is some photos / videos:
- Photo pack can be downloaded here: https://we.tl/t-DRfoEd0AQB
- Video of poorly printing gradients in Onyx: https://vimeo.com/773159706/1365161f81
- Video of perpendicular banding: Video: https://vimeo.com/773162433/67e9283ad0

Material is as flat as possible, obviously printing water based inks on paper (sublimation) it's hard to be perfectly flat. But this is only occuring on light colours where the paper doesn't rally wrinkle at all any way.