Mimaki JV33 Banding issue

[stickermonkey]

Hello...I'm hoping someone will be able to help me with my issue. I've been experiencing sudden banding when printing. I've done all the calibrations I can think of. I've even discharged and washed, nozzle washed, head cleaned...not sure what else I can do. Now...upon taking a closer look at the head, I noticed what seems to be little bumps on the left edge of the head, about 1/8" from edge. The bands are approximatly 1/4" apart going from left to right and with the print direction. Any insight? I've only had this machine for just over a year and got about 2 hours training on it. I feel like I've done pretty well with most issues..but this one is giving me that good old scratch ur head fever...and I thought someone here might have an idea.

Thanks!
Kyla

 

[Letterbox Mike]

It sounds like the head is dirty and is rubbing on the media. Have you moved the head over to the left and actually cleaned around it with a swab and cleaning solution?

 

[bentotdagr3at]

Get the build up out and check your blue squeegee on the machine.
it's probably worn out.

 

[stickermonkey]

Yup...I've done that Insignia...I have a new wiper coming in anytime today too. Unfortunately I had ordered 2 last week because I knew the time was nearing to have to change it...but they sent me the wrong ones. ) lol...anyhow...I'll do some more cleaning & calibrations and see what happens. I sure hope it's not a bunked head. Thanks for your suggestions!

 

[Letterbox Mike]

can you post a picture of what the banding looks like? The bumps you describe at the left edge really sounds like ink buildup that could be rubbing on the media. But it's hard to say for sure what kind of banding you are experiencing without seeing it.

Is your test draw good with no missing nozzles?

 

[stickermonkey]

Ok..I have no idea how to add the photo here. I agree, the banding could be caused by ink build up. Any ideas of how I can get rid of this?

 

[Letterbox Mike]

If it's ink buildup, you have to slide the head all the way to the left, remove the maintenence cover (4 thumb screws), and wipe the bottom edges of the head with swabs/cleaning solution. Spend as much time soaking it with solution and wiping with the swabs until it's perfectly clean. This should be done at least once a week if you don't print much, more frequently if you do print alot. We do it twice a day. Also clean the wiper really well and clean the capping station cap top with the swabs as well. If you've got alot of buildup on the bottom of the head, there's probably alot on the wiper and cap top as well, all of this equals an insufficient seal with the bottom of the head, which will eventually lead to dried out nozzles.

If you've never done this before, let me know and I'll try to post up a detailed writeup on it.

 

[stickermonkey]

I beleive that the cleaning regimen I'm using is what you are describing. When we print a lot, we clean it a couple times a day. Especially if we are switching the media. I am quite anal about the caping station...but perhaps I'm not doing it correctly. I didn't receive a great deal of training or direction on maintenance by the company we bought the unit off of. By all means...if you can be more detailed...I'd be very grateful to you. The one thing I remember is the tech/training guy telling us NEVER to touch the print head.

Do you use anything other than swabs to clean around the head?

 

[Letterbox Mike]

Nope, just swabs soaked in cleaning fluid. Sometimes we'll scrape the edges of the head with a fingernail VERY lightly to break loose stubborn buildups, but it's risky. Technically you car swab the underside of the head (the nozzle plate) but you must be very very gentle and apply no force to it whatsoever. The risk of touching the nozzle plate is forcing gunk back into the nozzles and causing them to clog even more. But if you very gently drag a very wet swab across them this can help clean them and draw out any waste ink/gunk. But if you're not comfortable with this, don't do it. But it is absolutely critical that you remove every speck of buildup from around the edges of the head, you want it to look brand new. Any buildup can cause an insufficient seal with the capping station and can drag on media as I suspect you are seeing.

I'd still like to see what the banding looks like. To upload a picture, click on "go advanced" when you are replying to a post and then scroll down a bit, you'll see a button that says "manage attachments". This will open a popup window that you can browse to and upload images. Just like when you attach images to an email, very simple...

 

[stickermonkey]

Ok...I'll send you the pics. I hope you can see it.

Kyla

 

[Letterbox Mike]

That looks like the media compensation is way off. Do you know how to adjust it? If not, while the printer is printing, hit the function key, then enter and you can adjust it on the fly. It looks like it is way too low so try increasing it by 20-30 and hit enter to see if it gets better or worse. If it gets better, keep adjusting it until the lines go away.

 

[stickermonkey]

I've never done that during a print...but I'll try it. Though...when doing the media comp during calibrations it looks good. Once thing I have been wondering in my list of calibrations, is if it's better to do the drop position correct before or after the compensation?? I was taught to do the compensation first then the drop pos correct. Any thoughts on this?

And BTW...thanks sooooo much for your help so far. It's been really appreciated!!

 

[Letterbox Mike]

Media comp has no bearing on the drop position calibration, technically media comp shouldn't be grouped with any other calibration. Media compensation adjusts how far forward the printer moves the media after each pass. If it's set too high you will get white lines or gaps between each pass, if it's too low, you will get dark lines between each pass, which is actually the passes overlapping each other as it appears you're experiencing. Every media will have a different media comp setting, and each profile should have it built into it.

Every time you start a print, you should watch the first few passes to determine if the media comp is set right or not, if it's not right, adjust it right then and there until you see no white or dark lines. We do this on each and every print we run, and almost every time it needs to be adjusted. If you get into the habit of doing it, it's not too bad, it only takes a second to do and your prints will always come out better. It drives me nuts when I see things other companies have printed and I see a media compensation issue, it's so easy to adjust, there's no reason to let anything go out the door without it being perfect.

 

[stickermonkey]

Well...thanks a bunch...I will definately do this from now on. Thanks so much. I really never thought that the comp could still be off even after doing the comp calibration with printed test strips. Again...thanks so much.

I definately would NEVER want to send a print out looking like this. And I'm just about to print some 4x8'ers with full coverage. It just won't do with bands like that. And yes...when I see a competitors work looking like this...I question the intergrity of the person handling the work. I take a great amount of pride in the work I put out there...and I am known for the highest quality work. This is why I have been spending the last couple hours going back and forth with you! :U Rock:

So thanks again man!

Kyla
Cochrane, Ontario, Can

 

[Letterbox Mike]

Good luck, that should work. It's still not 100% possible to tell that's the problem from a photo, but it sure looks like it.

FYI the media compensation calibration where the printer actually prints stripes is basically the same thing, but you can't do it this way by eye, you need a loupe (like a little magnifying glass you set on the print) to inspect the individual dots. You then adjust it up or down and it prints another set of stripes. Compare the distance between the ink drops from the previous one and adjust again until you can't tell where the pass was. This is super accurate, but it's tedious and you have to do it on every media before you print. And it's not really necessary, it's so accurate it's not even detectable by the eye. Adjusting the compensation on the fly after the print starts is alot easier and quicker, when you're actually printing an image you can get the compensation "close enough" that you don't sacrifice print quality.

Just remember though, if you're printing something thin like poster paper and you switch to something else like banner material, or even vinyl, the compensation will be off and you'll have to readjust. Also keep in mind, if you use the takeup reel, the pulling can even throw it off, so we usually double-check it after we put the print on the takeup, just to make sure it hasn't changed (it often does).

 

[stickermonkey]

all really great advice...thanks so much. And yes...every time we switch material a new comp is done as well as other calibrations. ) I hope it works...I haven't had a chance to get back to my printer room yet...I'm working on paperwork and quotes! ( oh and signs 101 threads! lol)

Cheers!!
If you're ever in Cochrane Ontario....stop in to AD Impact