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RS640 – poor black print quality
I had the engineer out to my machine last week. All is ok, however the black isn’t perfect. It was acceptable though.
I was advised a new head would bring it back to the same quality as the C M Y test prints.
Trouble was today printing a 100% black background A0. It wasn’t banding like the calibration was off, but looked like fine scratches across the print. I tried adjusting the calibration and bi-dir with no change.
As a last ditch attempt to get the work done, I just printed it on high speed omni directional and it improved dramatically!
In my mind I can’t understand why it disappears on omni, as its the same print head??
Does it sound like a new head is required or is there something obvious I am missing?
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19 Replies
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i need to understand "scratches"… is this a random repeating pattern.
I get smudges on my prints at start of printing, this is grease from loading a roll.
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They look like fine scratches, or like the paper has a grain when it doesn’t its a smooth semi gloss. Photo tomorrow when I get in will help!
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had similar the other day found the head on high just a idea
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Hi Chris I tried changing the head height.
Attached is a pic of the print from last night.
The Feed Calibration is fine as when on Omni theres no banding, and I printed 12 A1 at the same time using Bi-Dir and they came out perfect.
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ok so we are now talking horizontal banding, not marks.
So is this ink build up?
Perfect test print without ANY deflection of nozzles in the head before and after your black test?
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I suppose it is horizontal banding… it just doesn’t look like the typical banding I get when the feed calibration is out.
Attached is the test print off the machine.
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To be perfectly honest with you, you’ll never achieve a perfect print with the K head in that condition. The C head isn’t perfect either but I wouldn’t worry about that too much while your K is like it is.
You could try doubling the passes to hide the problem. It won’t use any more ink but it will take longer. Have you given the heads a good clean up?
Stafford
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When I say cleaning, I mean manually, with a swab and some cleaning solution. And also bare in mind that the worse condition the K is in, the more difficult it is to calibrate the other perfectly because generally speaking all the other heads are calibrated to the K.
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Machine gets a manual clean once a week. Due one tomorrow.
It is hard to calibrate as you say because the pattern is black.
I just found it strange that it printed fine on omni but not bi-directional.
Stafford is it new print head time? Engineer reported the heads nowhere near its life expectancy.
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wow, lots of deflection, as I always been a mimaki man, "its always the freaking black!!"
I used to get upset on the first nozzle that deflected, you will see uneven patterns with just one nozzle.
So Life Capacity, isn’t that to do with how long a head will operate for before it fails, millions of shots?
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Billions of shots. Mines no where near that. The machines had a really easy life compared to others.
Luckily my service contract will cover it to an extent. I just pay for the head, no labour, call out. If I recall they estimated about £500.
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Just having a think before I decide to get the head replaced.
Would it be worth getting a cleaning cartridge and trying that first?
It might improve the Cyan if nothing else.
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it is up to your service contract representative to guide you
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As Dave says, the Mimaki’s have real problems printing well with only a couple of deflections, as do Epson. Roland on the other hand seem to get away with it a lot more somehow, even though they use more or less the same head.
Running a cleaning cartridge certainly won’t hurt, and may help it. The best thing to do it fill the caps up with solution and switch it off at the wall over night with the heads soaking in it.
It’s worth noting that a printer that’s been run ragged all it’s life is likely to have better heads than one that’s not done as much, although the motors and pulleys will be in better condition on the one that’s been used less.
Contact me if you want any help or suggestions
Stafford
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Cheers Stafford the machines not running today so I have taken your advice to see if that improves it any.
Had a price in for the new head.
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Do you mind me asking what price you were quoted and by who?
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£650+VAT by my service contract provider 😉
Not sure if that’s a good price or not??
Attached is another test print after soaking the heads for 4hrs.
it looks better to me.
UPDATE
Massive thanks Stafford, your recommendation whilst not fixing the problem 100% has improved it dramatically, I’ve just had to run out 12 A1 poster each with a B&W image and there’s nothing wrong with the print quality.
One last question, how frequently should the printer do its automatic clean?? I think mines set to 12hrs, but might not be frequent enough to keep the ink circulating through the heads.
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Sorry David, I only just noticed your update 😳
I’m glad my suggestion helped, it’s looking much better now. I think the Mimaki JV3S/SP standard cleaning times are 8hr periodic clean and 4hr sleep clean. I’m not so sure about other printer models alothough I’d guesss they should be about the same.
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How did all this end?
we were quoted about £1050 to fit a new head for VP540.
I see almost all the Epson DX4 heads can be recovered now?
the bi directional adjust is not referenced to the K as i see it but each to its own colour
G
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