Mimaki JV3-250SP streaking/Ink starvation

[Fabritech]

Hi, I have a JV3-250SP that typically runs on CMYKLcLm 360x540 6 pass,
and I have a recurring problem with it when I need to print large full-coverage banners (around 6'x10' & above.) It will run fine for awhile, then slowly start to lose color and streak until one or more of the colors almost completely drops out (usually the main color in the print.) I can then pause it for a minute and restart it, and it will go back to normal for a little while but will suddenly lose color again. Techs have changed and adjusted multiple things on this machine to no avail. We can force the problem to occur if we run the Y motor test for a few minutes (this is when the carriage goes back & forth the width of the machine fairly quickly,) and then run a solid color 78" wide. I have the Triangle bulk-ink system, and I even have the tanks raised slightly higher than specified in the instructions. I believe that it is an ink flow issue because I once raised the Magenta tank by about 5" when I printed a mostly solid red banner and the problem went away. However when the red part of the banner ended, and the yellow part began, the red ink dripped all over it because the tank was too high, and it was not using the ink. Slowing the machine down to 360x540 12 pass helps, but I cannot run bulk banners this slow. Below is a list of what has been done to the machine:
-Changed & re-aligned all heads several times
-changed oversize dampers
-changed pumps
-changed filters on bulk ink
-flushed lines
-Changed O-rings in ink line junctions
-Adjusted Y-pulley
-replaced plastic hose junctions on waste hoses w/ metal ones
-re-aligned docking station
-tested X & Y motors
-Bulk Ink tank vents are not clogged, and the ink flows fine during a "Fill-Up Ink" cycle.

Can someone PLEASE help me on this issue?

 

[eforer]

Well, the tank height and over sized dampers would be the normal fixes for something like that. Have you tried increasing your refresh to 2 or 3?

 

[Fabritech]

I'm not quite sure what the "refresh" is. I have the printer set to wipe the heads about every 10 passes. My refresh option on the printer specifies "host," but I cannot find anywhere to adjust it in my software (PhotoPrint DX 4.0.)

 

[eforer]

I'm not quite sure what the "refresh" is. I have the printer set to wipe the heads about every 10 passes. My refresh option on the printer specifies "host," but I cannot find anywhere to adjust it in my software (PhotoPrint DX 4.0.)

Set the priority for refresh to local and try setting to 3. It brings it back to the capping station and pulls a little ink through the cap to flush out the heads and top everything off. The higher the refresh level the more frequently it does this.

 

[Fabritech]

The refresh is already set to 3, so I do not think that is the problem.

 

[eforer]

Do you have any OEM ink carts to test with? How old is the ink in the bulk system?

Are the metal perforated caps in the capping station clogged at all?

What is the relative humidity in your print room?

 

[schurms]

Dumb question............ are your bulk inks sealed or is there a hole in top ? Could be a venting issue.

 

[eforer]

In the first post he mentioned the vents are cleared, but if they were plugged it would definitely hamper flow.

I get the impression that he's printing in a 360X360 4 pass mode for banner production. I very rarely print 4 pass, and I'm curious if it would happen to me with my triangle inks.

 

[GTSTech_1]

A few more things to check......

1. Is printer Level?

2. Are your filters on the bulk system clean?

3. Are the head ranks right?

Concur with Eforcer about raising the bulk system and hi-flow dampers usually do the trick.

My $.02

GTSTech_1

 

[Fabritech]

1) The printer is level. The current filters on the machine are pretty new; we have changed filters many times so far and that has never fixed the problem. I am not quite sure what the head ranks are, but the heads have been changed and adjusted multiple times since this problem surfaced. I am already using oversize dampers, and have tried switching them out as well.

2) Tank vents are still clear, and I am running mostly on 360x540 6 pass.

3)The room is climate controlled, but I could not tell you what the relative humidity is in it. The capping station has been "re-aligned" by a tech, but it was never clogged; the machine gets cleaned on a weekly basis. I no longer have usable OEM cartridges to test it with. We switched over to the bulk system when the printer was pretty new, and if I remember correctly, it did do this once before the bulk system was installed, so I do not think that it is a problem specifically with the bulk system.

I have since changed out the Y-motor at Mimaki's suggestion, but that did not affect the problem. My next step is to try running larger ink lines from the tanks to the heads. I am really running out of options, and Mimaki seems to have given up on the problem. Any other comments/suggestions would be greatly appreciated.

Thank You

 

[eforer]

That sucks something awful. I hope some of this was still done under warranty. I have 160s so the width thing makes it hard for me to make an a/b comparison.

I guess the only things left I can think of are:

Damper priming: If you draw too hard too fast with the syringe (if you syringe prime) you can sort of flex out the dampers and they won't work well or last long.

Weak Pump: If the parasaltic pump isn't pulling hard through the capping station, ink won't be drawn through adequately when it refreshes at the capping station. Could cause flow problems.

Excessively low humidity: Can cause the head to dry out and have flow problems/nozzle drop out during fast scans. I like around 68-72 deg and 40%-50% humidity for vinyl films and banners.

Kinked or restricted ink lines: If the lines are obstructed by an tight tie wraps, hard corners or kinks it could cause a flow problem.

Have you tried 720X720 8 pass? Its too slow for production speeds but if the problem goes away it tells us more about the problem.

One more thing to mention. We clean our printers at least every other day with the JVS ink.

-Ed

 

[jmcnicoll]

We have the same problem on both our JV3 160 and JV3 130 printers. We are running Onyx Production house for both, plus our Epson 11880. Temp is set at 70 and humidy is usually in the 40-55 % range. Out 130 was brand new at the the end of Feb. and the 160 has 2 new heads, new dampers, new pulley, now motor and more. I have done everything I can think of plus what our vendor has tried along with suggections online in this forum and others. Our vendor wants us to switch to the Fiery rip as they said they switched to it 6 months ago because of consistency problems they had with onyx. Anyone think this could be a rip issue? I clean them everyday, try to keep the environement as consistent as possible. Problem shows up with both custom made profiles and canned profiles from onyx. jim

 

[eforer]

I have a hard time believing its the rip. Do you still have crapsterlink... I mean raster link that came with your new machine? It would be worth trying some prints with the canned profiles to see if the rip is the problem. I doubt it is though.

 

[Fabritech]

Some of the work was done under warranty, but because the problem was intermittent (it only surfaced on very large jobs,) we had no way of determining if it had been fixed without wasting a ton of ink & media. Only recently have we been able to force it to show up using the Y motor test. I am waiting on my larger diameter ink lines to arrive, so we will soon know if the problem was from that. We now print large full-coverage banners on 360x540 12 pass Unidirectional. It is miserably slow, but the problem is less likely to surface at that speed. When it does, the color dropout is nowhere near as drastic as it is with 6 pass, so it is much easier to correct.

 

[ColesCreations]

We are having the same problem with our 160 SP, with 6-color, running 8-pass, 720x720.

We are changing to dual CMYK, hopefully we will get almost twice the ink capacity.


After reading many posts with similar problems, it seems as if the heads "run out of steam". Dark colors demand a lot of ink, so we get the "rainbow" effect in our prints. Looks cool, but the customers will not pay:Big Laugh

Maybe it's just a limitation inherent in the printer? When printing large areas of dark color, maybe there is a maximum speed?

 

[jmcnicoll]

That's funny you say that, we have a tech coming again today to see if he can get them working better. He's going to try and fix it if he can, but also said he may have to switch us to 6 color to get rid of it. I had great prints coming out of both of our machines about 2 months ago, but since everything has got slowly gotten worse and worse. Printed a banner stand yesterday on fabric with a custom 2 ink layer profile at 720x720 16 pass and it still could not print a smooth dark blue. FREE Brett Favre print to whoever can solve the problem!!!!!!!!!!!!!!!!!!!!!

jim

 

[ColesCreations]

Jim-
If your problem is getting worse- can it be damper-related?
Then again, how do you tell that the damper is bad? We have had this streaking since the machine was new, on dark purple and dark blue, have been told it was due to profile, but can not imagine why the profile should change from one pass to the next?
I do NOT recommend going to 6-color, we have been running 6-color for 6 months now, and fine art stuff goes to the Epson 10600 printer...
(and with fine art being the only reason for having 6-color, and the Mimaki being unable to print fine art...)
PS: With fine art, I mean photos taken by professional photographers, framed, and mounted on walls for close scrutiny.

 

[CL Graphics]

I have the same problem with blues and purples on my JV3. Had the tech out last week. He changed a print head but it made no difference. I have rasterlink and wasatch and it does it with both rips. It seems to be at its worst on oracal and 3M viny. It prints decent on avery. Problem is we use mostly oracal. Only way I can get rid of most of the streaking is to print on 16 pass. But its way too slow and it still shows up a little. If you figure out how to fix this let me know. My warranty runs out in about a week and a half so I guess I better call mimaki on monday.

 

[jmcnicoll]

Our vendor tech was in on Thursday and switched our 160 to six color, which I think is only to see it if works or not. So far it has helped, but problems still shows a little and don't think it's gone. Dampers had been changed just weeks ago by another of our vendor techs. At this point they are just praying that something fixes it. They have talked about swithing us to Fiery for more constistant color. I don't think it's Onyx, but many of the issues with Onyx frustrate me as well. At this point I just want them working!!!!!!!!!!!!!!!!!!!!!!!!!!

jim

 

[ColesCreations]

Today I switched from 6-color to Dual CMYK, and wow! Twice the speed, or, to be more accurate- the passes are twice as wide, which mean we can print 16-pass dual at the same speed as 8-pass 6-color...
I hope this will make a difference; have not had the chance to check much yet.

One thing though- with dual CMYK, my theory is that faulty prints in one print head will be masked / hidden by the same color print from the other print head with the same color.

I hope Mimaki paid for the ink used to switch color configuration for you!
I cheated and unplugged the pump hoses for most of the pumping cycles, and it still filled up around a quarter of the waste bucket, around 500 cc, or $150 worth of ink...