"OverSpray" issues with my Mimaki JV3-160SP

[MikePro]

Long explaination, apologies in advance for the long read. Print issues resulting in having a service tech. come out here expecting to replace print heads... but after vigorous re-alignments, he talked me out of replacing the pricey heads because the problem was most likely due static discharge as a result of low humidity and also mentioned that using my 3rd party inks couldn't be helping, since he lacked experience with Bordeaux inks, and wouldn't be able to rule that out as a cause as well.
Although, I had been using these inks for the past year, approx. 60-100 cartridges worth, and haven't noticed any issues, or progressive changes in anything thusfar. One day my printer was working, and now its working... but not as well.
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this has been happening, for the past two weeks. Black and Cyan vectored lines and shapes are turning out with an "Overspray" effect. Although, at whatever pass/resolution i run it at, the displacement actually appears to happen AFTER the passes complete and are almost fed past the heads when an "Ocean Spray" effect seems to happen, contaminating my whitespace with Black or Cyan, depending on what color is being used in the nearby shape.

My printer is immaculately clean, and test prints only show minimal nozzle displacements in the horizontal lines (typical of regular need for nozzle wash/etc, but i've also let it soak plenty of lengthly times), and under the scope, the vertical lines appear a bit more jaggedy than the magenta and yellow patterns (which are nearly perfect, i typically keep an extremely clean machine/environment).
I've already moved everything out of the room shy of my computer/printer/exhaust, and put in a humidifier to help keep at 50-60 humidity, per spec.... but i'm still getting overspray.
p.s. I do realize, that in the image, a couple of the black text shapes print with a blue hue, which I found was a result of the shopping complex's designer using different black swatches that included a 4color black (fix'd!), explaining why there's a Cyan overspray mixed in with the Black overspray in those elements.
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Any ideas? Haven't ruled out heads, but 2 new print heads... installed... would run me around 3k. Aaaand I do realize that I've saved more than that on my bordeaux inks, and can just suck it up and get 2 new print heads. but I still have faith that it is something else I may be missing

 

[J Hill Designs]

I'd start with static as a cause...rub the media with a dryer sheet as it feeds..heard that helps..

 

[MikePro]

i'll give it a try, i've also noticed the other threads here on the forums related to the topic... shame their only resolutions were heavy part replacements, followed by more, followed by hoping there aren't more to come.

 

[Consort50]

check your print heat settings,I've had this problem in the past,I have the same Mimaki..turn your heat up and see if it helps.

 

[iceman64]

Did you put in the head serialnumber in the machine as you changed the heads, each head is set with it's own settings like voltage etc.
If the voltages are wrong inside the head, you might get messy prints.
Also you may try slow speed printing.

 

[MikePro]

haven't gotten the new heads, yet. I'm still looking into buying a set, just to have as backup, should i have to replace them all someday.

 

[JK999]

I had the same issue with my JV3. I pulled out my pumps, dismantled them and cleaned out the tubing with some wire to loosen up the dried up ink and then blew out the ink "boogers" with some compressed air. I also made sure the tubing from the capping stations to the pumps were clear. I put it all back together and the blue overspray problem disappeared.

 

[Rooster]

It's a long shot, but I didn't notice anywhere in your list of stuff you've tried, running any drop position test prints or cleaning the encoder strip.

I wonder if bordeaux could confirm any changes to their formulation between what you're using now and prior batches. It's usually not the ink though, but if it's easy to confirm a change in formulation it could be an indicator of something to check out.

Nozzle deflections can and will cause very similar effects to the pic you posted. Maybe post up a pic of the nozzle test. Sounds like you've identified issues with it, so let's see how bad a shape it's in.

 

[artbot]

you can isolate/eliminate the static issue by "wiping" it off of a test piece. take a sample of material off the roll. place it flat on a table. with a piece of felt (or sock but that doesn't work as good). very deeply burnish vertically half the material. so that at the scan of the print carriage, the heads print across a burnished and unburnished area. if the ink behavior prints much better in the burnished portion of the material, then you do have a static charge on your material. by doing this you knock off the charge.

hairy structures growing in the ink on the material after a print pass is long since done is also a sign of dyne and drying issues. the ink's meniscus is being broken and thus the fluid is wandering way passed the point of basic dot gain.

i'd do the static test, then do a data swap at the ribbons. (we can lead you through this if you've not done it before). and definitely clean the encoder strip. but do each one then do a test print. otherwise it might disappear and you'll never know what fixed it.

 

[MikePro]

changed out my K and C heads, everything is in and working.
Test pattern comes out perfect, all nozzles firing correctly, but anything else I send out with Cyan in it is still overspraying. I thought I've ruled out static, especially since this is only happening to 1 color.

also noticed that there is dusting of ink all over EVERYTHING inside the carriage (black on the red, red on the blue, blue on the yellow), think that's a symptom or just a common mess?

still pretty excited that I know how to install my own heads now, but almost wondering if it was necessary to begin with... the K and C had at least 20+ misfiring nozzles, so its nice to see them printing a proper test pattern again... at least.

 

[artbot]

hmmm.... this dusting of ink and the post carriage pass overspray thing still points to an ink issue. each ink has a different viscosity. yellow is usually the highest, others can dry faster because of resins used and ratios of glycol ethers. so just because it's cyan doesn't mean that you can eliminate static.

this dust. can you photograph it? you are getting close to a cause and effect here. when static occurs on a print. you have the initial lay down of the print. but there is a charge in the air and or on your material as well. these static charges create invisible patterns on the substrate. the lighter and dryer in the air a paint/ink is the more likely it is to "chase" these charges and magnetically stick to them. do you have any silver or gold, or flat black spray paint and a sheet of acrylic. pull the paper backer and about four feet above the sheet mist the spray paint. the paint partially dry in the air and fall to the acrylic sheet and paint the sheet according to where the static charges are. it looks very cool.

if you have ink dusting all around the interior of your printer you have airborne ink floating in the hull of the printer and because of a static charge, that ink will fall just the same onto any charged patterns.

with the cyan issue, i'd start with doing a damper swap to see of the issue can be moved to a different head. so swap some lines so that for instance cyan prints from a different head. does the ink issue follow the damper/ink lines? or does the issue stay at the head. my guess is it follows the cyan link line. after that report the results.

the next step if it's inconclusive is to do a data swap. bit more complex. but it can be easily explained.

 

[MikePro]

I'm thinking its a slant issue, for which I don't especially know how to fix... based on lack of instruction in any manuals i'm able to find.

How do you tweak this? All the colors in the slant line up, but the Cyan is staggered.
Test print looks good, all nozzles firing. But in my print, same version as my first post/attach, the black is solid and not overspraying... but the Cyan is comming out WORSE! Cyan halo around any shape that includes a Cyan in the formula.

 

[MikePro]

larger slant image attachment:

 

[artbot]

do the damper swap. it will open up a huge set of possibilities or impossibilities. if that issue moves to a new head. than you will know that it's not the slant. because the slant on the new head position for cyan is fine.

damper swaps are the first and best diagnostic protocol for isolating an issue above or below the head.

damper swap:

keeping all the installed/used dampers attached (depending on if you are running double cmyk or lmlc) move them to a new head position so that the color of ink coming from two different heads have been swapped. the ink lines will be crossed. create a file that isolates and combines ink values that you think will show the issue moving across to a new head (this depends on what color was swapped with what color).

 

[MikePro]

damper swap? i'm running ss2 2x4
by that you mean Plug my yellow into my cyan and vice versa to see what happens next, right?
or completely install new dampers?

 

[artbot]

yes, cross the lines. the cyan needs to be isolated. the only way to do this is to put the cyan lines on a different head and vice versa. changing out the dampers before doing this will hinder your diagnosis because you will lose your "control" of scientific method.

for double cmyk, run cyan to the yellow position, and yellow to the cyan position. if the cyan heads start overspraying yellow then you will know that it is not the ink supply. if the yellow heads start overspraying cyan than you will know that it is not your heads.

create a file that is a block of solid yellow and a block of solid cyan and also a file that you know has been printing badly. this should take about 15 minutes. you'll need to decontaminate the heads because there will be some latent ink that will mix. so do about two normal cleans and do a test draw to see that the colors have cleanly swapped positions.

 

[artbot]

better yet, switch cyan with magenta maybe? yellow is a bit hard to see in detail when printed alone.

 

[MikePro]

I'll put it on my list of diagnosing to try, but i'm still worried about the head alignment itself. I don't think you can see it in my test draw attachment, but after swapping my K and C heads... there's a gap between the Black and the Magenta... and the Magenta and Cyan overlap at the front of the Y-axis, but has a gap at the rear of the Y-axis.

I'm leaning towards, even though I have the ability to swap the heads, my lack of knowledge how to mechanically align the heads after install.
I've run the #printadjust2 sequence, but skipped over the head adjust and slant adjust.
digging for info atm

 

[Rooster]

Head slant adjust is very important to do any time your replace a print head. It won't be the cause of "this" problem, but will be the cause of other quality issues if not completed.

 

[artbot]

are you thinking to diagnose this you need to swap heads? you just need to swap damper positions. two cyan damper/ink lines going to say two magenta print head positions. and two magenta damper/ink lines going to cyan print head positions. there will be no touching of the print head or it's alignment adjustments.

the head alignment will cause uncrisp printing or banding in solid areas. what you have is something completely different. you will not repair this issue without first doing the damper swap. it is the "step one" of diagnosing this kind of issue. "step two" is data cable swap. let the printer tell you what is wrong with it.