Mimaki clogged nozzle: good cleaning trick or stupid idea?

[stevenjowens]

Hi guys,

I have a mimaki JV3-160SP. The black nozzle seems to be partially clogged. I'm working on getting a good photo of the heads (kind of hard to get in there with a camera) but attached is a photo of a test pattern.

I've been doing a lot of nozzle washes and printing, but so far seem kind of stalled. Searching the internet, I came across this file named "Tech-Tips-Mimaki-JV3.pdf", which among other things said:

"For nozzles that will not unclog with normal cleaning:Use syringe with damper and flush print head out. Attach damper to normal position
above print head and force cleaning solution through."

I understand what they're suggesting here, just had to replace a damper. Seems straightforward enough as a process:

- Either figure out how to attach a syringe & hose to the damper connector above the print head.

- Or frankenstein a syringe onto a spare damper in order to connect the syringe to the print head.

Either way, use the syringe to generate pressure to push cleaning fluid through.

Does this seem like a sane idea?

 

[stevenjowens]

Whoops, forgot to attach the test print. Should be attached now.

 

[Vinylman]

Cleaning print head

What you are considering is "possible", but with GREAT CAUTION!

I would caution you IF you do this, GO SLOWLY. USE VERY LIGHT pressure on the syringe. If you can get someone to assist you, set up a BRIGHT light that will allow you to see clearly the bottom of the print head while you are flushing it out. I would also use a good mirror so you don't have to stand on your head to watch this procedure.

Move the print head all the way to the left side of the machine [on my JV33 there is a removable front cover} where you can do this service procedure. I might suggest you start with a straight factory flush solution. If it doesn't clear after several minutes of GENTLE [ did I mention being GENTLE?], flushing, you might add a 50/50 solution of flushing solution mixed with MEK. This is a VERY STRONG dangerous solution, so handle carefully.

IF, or when the head clears finish up with a follow up flush IMMEDIATELY of factory flush solution. You DO NOT want to leave the MEK/ factory flush solution in the print head. Get ink back into the head ASAP and do a test print.

While doing the flush process, make sure you watch [with the mirror] the bottom of the head to see if the nozzels are beginning to clear. You can tell because the streams will be clear and straight down as the nozzels open.
Another possible tip you could try, is to again VERY GENTLY pull a reverse pressure up through the head into the damper. ONLY very little pressure during this step, and only for a second or two. You are trying to pull any dried ink away from the nozzels so they can be broken down and brought back into solution so you can then flush them back through the head in the correct direction. {ONLY DO THIS LAST STEP AS A LAST RESORT}

 

[stevenjowens]

Thanks. A bright light, a mirror and a large magnifying glass seem like good things to have handy.

A couple questions:

1) Any steps or things you would suggest attempting before trying this?

2) Would you suggest finding a way to connect the hypo hose to the printhead directly (i.e. by the same fitting that the damper connects to), or would you think it better to do hypo-to-damper-to-printhead?

3) What's a "straight factory flush" solution? I have "mimaki cleaning solution" (sold in small, expensive quantities).

4) To make sure I've got it right, use forward pressure only, don't try reverse pressure until I've decided that the printhead is otherwise a lost cause.

 

[Vinylman]

Thanks. A bright light, a mirror and a large magnifying glass seem like good things to have handy.

A couple questions:

1) Any steps or things you would suggest attempting before trying this?

NO, you seem to have already tried most of the normal proceedures.

2) Would you suggest finding a way to connect the hypo hose to the printhead directly (i.e. by the same fitting that the damper connects to), or would you think it better to do hypo-to-damper-to-printhead?

You could do that, that is the way I have done in the past [one less thing to fiddle with also]

3) What's a "straight factory flush" solution? I have "mimaki cleaning solution" (sold in small, expensive quantities).

Cleaning Solution is exactly what I was referring to.

4) To make sure I've got it right, use forward pressure only, don't try reverse pressure until I've decided that the print head is otherwise a lost cause.

That would be the proceedure I would follow. The "REVERSE" pressure, should be attempted as a last resort, and with VERY LIGHT PULL on the syringe. It is only used to attempt to "pull" any residual ink particles loose from their hold on the inside of the microscopic holes in the print head membrane.

I see you are in Pitts. Pioneer Supply has one of the best techs on Mimaki available. His name is Brian, and if you need further advise, he is the person to go to.

I hope this helps.

 

[Solventinkjet]

1) Any steps or things you would suggest attempting before trying this?

Check the bottom of the print head for scratches and/or other damage. The JV3s have a problem with the cap top assembly where the screws slowly rise over time and scrape the bottom of the head. If that is the case, you need a new head and capping station. I usually recommend replacing the round screws with flat screws to avoid the problem.

 

[stevenjowens]

I see you are in Pitts. Pioneer Supply has one of the best techs on Mimaki available. His name is Brian, and if you need further advise, he is the person to go to.

Brian is indeed awesome, but he is no longer with Pioneer, as of a month or two ago. He's down in Ohio and now has his own firm. Unfortunately it's a 3 hour drive and the cost to get him up here is pretty high.

 

[stevenjowens]

Check the bottom of the print head for scratches and/or other damage. The JV3s have a problem with the cap top assembly where the screws slowly rise over time and scrape the bottom of the head. If that is the case, you need a new head and capping station. I usually recommend replacing the round screws with flat screws to avoid the problem.

Thanks. I've noticed that those screws stick up fairly high, though I'm fairly sure that's not what happened here. I have taken a close look at the bottom of the print head and not seen any obvious damage. I'm trying to get a better close-up to be sure.

Any tip on what kind of screw to use? Or just unscrew one and take it to a good hardware store and ask them...

 

[Nuagedesigns]

I have had good luck with a similar issue.

Mine was however due to the pump lines being warn out due to age.

I would remove back panel of machine where your two ink pumps are located.

Remove drain lines from waste ink bottle and pull suction though drain line and capping station with syringe.

Once I had ink flow though line I would replace in waste bottle. Replace cover.

Load material and run 2-3 test prints and head cleanings. This would work everytime.

The pump works off of a set of eccentric rollers that are continuosly turning on the same section of tubing that tends to compress and deteriorate.

My issue was also with my black print head.

Best of Luck.

 

[jfiscus]

A brake line bleeder works VERY well if used to pull ink through the heads while they are resting on the capping station.
Use light pressure.

It looks like your magenta was already damaged by the capping station screws, and I'm going to go out on a limb and say the black is too and now it isn't even sitting down on the cap correclty resulting in an incorrect seal and nozzles not firing. Replace those screws with flush mount screws (take out one of your screws and go down to your local hardware store) asap and TRY doing the head flush/push/pull; but get ready to call the tech out to put in a couple new heads.

 

[stevenjowens]

I have had good luck with a similar issue.

Mine was however due to the pump lines being warn out due to age.

I would remove back panel of machine where your two ink pumps are located.

Remove drain lines from waste ink bottle and pull suction though drain line and capping station with syringe.

Thanks. We've pulled the ink through the lines as you described, and it hasn't helped.

It did help us isolate a problem with the yellow ink head, a damper that was leaky and therefore wasn't getting suction, wasn't getting filled, etc. We fixed that temporarily with a bit of tape and ordered a replacement damper from solventinkjet.com (thanks guys!). But we're still trying to get the black head fully functional.