Mimaki CJV30-100 losing CMYK during print.

[joeks]

Hi there,

Just yesterday I changed all 8 dampers on my Mimaki CJV30-100 with cheap Chinese dampers (complete with O-ring and screwcap). I bought the machine second hand and have the machine for 1,5 year now, so probably about time. Hoped it would solve some of the banding I can't seem to get rid of.
Everything went well, looks ok after visual inspection. No leakage and the dampers fill up to about 1/3 after I run the "fill ink" menu option.

Initial testprint was fine after a nozzle wash and hard clean. And the banding was almost gone completely at 12 pass bi-directional. So it looked like a succes.

But now, a day later, I am printing small batches of stickers and some of my colors completely disappear during print!
Mostly magenta but other colors too. Can get most of them back after a couple of cleaning cycles (hard cleaning and nozzle wash 20 min) but this shouldn't be happening.

Is there something wrong with the dampers or the capping station? Cap top is about 6 months old.
And noticed the capping station got soaked with ink, cleaned it completely tonight -like brand new-, but after a small sticker run it was wet of ink again. Pump was changed 6 months ago.

Thanks for reading!

IMG_7428 by barrybuise, on Flickr

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[joeks]

Let the printer sit overnight by shutting the power down during a nozzle wash.
First test today resulted in a testprint with loss of color and some colors that were mixed with one another.

After several hard cleanings and a 20 minute nozzle wash I got most of the nozzles back, but still have the color mixing problem.
And I am pretty sure I can start this all over again tomorrow when I lose most nozzles and colors again.

Could this have to do with the new dampers? Install looks good if you ask me, and I see no leakage at dampers.
But troubles started half a day after changing the dampers.
Or do I have to buy a new capping station or cap top? (replaced 6 months ago)

I could really use some help with this
Thanks for reading!

IMG_7460 by barrybuise, on Flickr

IMG_7461 by barrybuise, on Flickr

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[joeks]

Just got a quote back from the Mimaki tech.

€426 for 8 new Mimaki dampers
€87 for a new cap head assy
€108 for a new wiper kit
-Optional- €621 for a new y-axis motor assy
+ €160 in transport
+ €98 per hour of labor.

Problem is, I can't seem to solve the print problems I have.
Currently have installed 3rd party cap top, dampers and ink.
OEM is so much more expensive, but does it really matter quality wise?

For example, the third party dampers I previously bought were €20 for 10 pieces.

Same with ink. Currently use Digiprint brand SS21 ink which is €48 a piece.
Mimaki SS21 is €86 a piece.

 

[EffectiveCause]

Problem is, I can't seem to solve the print problems I have.
Currently have installed 3rd party cap top, dampers and ink.
OEM is so much more expensive, but does it really matter quality wise?

Some 3rd party products are ok but others are complete crap. Maybe you just got the crap ones. But OEM will always be better since thats what the machine was made to use. As they say, you get what you pay for.

 

[Solventinkjet]

The cap top could be bad. We have tried many different versions and some hit and some miss. That being said, if you haven't changed the cap slider yet, it's worth a shot to fix the issue. They wear out over time and can cause the cap to not meet up with the head exactly right and will cause issues like this. They cost about $3 in America so I'm sure they are even cheaper in Europe which seems to be the case for parts for some reason.

 

[joeks]

Thanks for your replies guys!

Just checked for capping station parts or a complete one.
The sliding part alone is €9, without spring.
A complete capping station is €50 for a 3rd party product and €150 for OEM. What would you suggest VanderJ?

 

[Solventinkjet]

Thanks for your replies guys!

Just checked for capping station parts or a complete one.
The sliding part alone is €9, without spring.
A complete capping station is €50 for a 3rd party product and €150 for OEM. What would you suggest VanderJ?

I would just replace the slider. The whole station only needs to be replaced if it is physically damaged.

 

[joeks]

Thanks, so just this part:
JV33 Cap Slider Assy 33 - M602088 - Onderdelen

And then probably a new cap top and sponge?

By the way, reinstalled the dampers today.
Inspected the manifold if the pins weren't broken or dirty (after speaking to a tech on the phone).
Manifold looks good. Gave it a clean, reinstalled the dampers (which look good too).
Same result, so next step to check is indeed the capping station I think.

 

[Pitzu]

If all started after replacing the dampers, those would be the first suspect.
Mixing colors can mean poor performance of the capping station (not evacuating all the ink resulted from the cleaning cycle - clogged or broken tubes inside the pump).
Same problem would be faulty damper.

I had the same problem with 3rd party double dampers for Mutoh.
Some of them had internal spring too hard and the vacuum created during printing was not enough to break the spring's force, cutting the ink supply to the printhead. The original dampers had softer springs pushing the membrane.
Not knowing what happend, I did lots of cleanings which resulted in faulty capping station (broken tubes).
Some have faulty damper valve (membrane) not closing, letting mixed ink from capping station being absorbed back into the printhead. You can see this when you remove the damper from the printhead and the ink starts to flow back into the subtank. A good damper should never let this happen.

If you still have the old dampers..just clean the black one with solvent and put it in the black channel (where I see the problem is more evident) ..and see if there is an improvement.

Just throwing ideas..hope it helps

 

[joeks]

Thanks for your help VanderJ and Pitzu!

Replaced the complete capping station today, makes no difference.
Still lots of missing colors, nozzles and color mixings.
I could be wrong but it might look like the cap top doesn't align perfectly with the head.
No idea how I can adjust that, if even possible.

By the way, it's not normal that the capping station base gets soaked with ink or am I wrong?
For example, the most right part of the base, next to the sponge. But also left from the cap top.
I mean, you install a nice clean capping station and minutes later it's sprayed with pool of ink.

Tried to salvage the old dampers, but they were dirty besides being old, and I didn't have enough solvent lying around to clean them.
So instead I ordered new Mimaki brand dampers today, will try if that makes any difference.
And buying and installing them myself also saves money if I have to let the tech come over anyway.

Untitled by barrybuise, on Flickr

Untitled by barrybuise, on Flickr

Untitled by barrybuise, on Flickr

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[Pitzu]

Some ink splashes can result during cleaning cycles, but not that much.
When you changed the dampers, did you change the wiper blade too? The blue one? It's very...clean..unless you've cleaned it before making the pictures. After some cleaning cycles that wiper should have some ink on it....like it's doing its job...

During the cleaning cycle, some ink drops will result on the printhead (which is normal) ...and the wiper should clean those at the end of the cleaning cycle. If it doesn't happen, you can have remaining ink drops on the printhead....resulting in "missing nozzles" or mixed ink.
I've noticed that in your second batch of pictures...you had some ink drops on the media. Even if your printhead touched the media, there shouldn't be that much ink, not on a nozzle check test. You should check that too, to eliminate a probable cause. After cleaning cycle, move the cursor a little and look at the printhead..it should be clean, without visible ink drops.

Blue wipers are more flexible and therefore more messier, throwing ink all over the place. The blue wiper advantage is that...if it stays blue..then the operator performed the cleaning maintanance at the end of the day...using swabs and cleaning fluid.
OEM wipers are usually black, less flexible, less ink splashing...but you can't see if the maintenance was done right
Dried ink on wipers can result in clogged nozzles. So clean wipers are ok, but during working hours they have to get a little bit dirty, meaning they perform well.

Those being said, check the printhead for ink drops..everything should be nice and clean...look at the wiper blade if it performs well...change the dampers with OEM ones...and see how it goes.

 

[Cata]

i think you have some air in the ink tubes or a cracked manifold..

 

[joeks]

I changed the wiper too, change it often. Indeed gets dirty after wiping but I have cleaned it prior to taking the pictures.
Didn't know the difference between black and blue wipers! Machine came with blue one when I bought it second hand. Never even seen black wipers for sale, but would indeed be better if they throw less ink around.
Will look for them, thanks!

The manifold looks good, I removed the dampers and cleaned the manifold with solvent, can see no cracks or broken pieces.

Will receive OEM dampers tomorrow and after install I will report back here.

 

[Pitzu]

We have two Mutoh Valuejet 1614, bought second hand. One has a 3rd party maintenance unit, noisier and messier, with blue wiper blade. Once, I opened the maintenance cover during cleaning and got ink drops all over me. It's not that bad, as long as I keep the maintenance cover closed .
The other one came with OEM maintenance unit, better cleaning performance, less noise and mess, comes with black wiper blade. For a moment I thought it was defective, since it was much quieter.