I don't like banding!

[ColesCreations]

We've been playing with our new Mimaki JV3, finally got it to print nice...

Then went to print a job, 12' long print, at first it looked like we were looking through blinds!?? lighter areas every inch or so.

Started over with 6 pass in stead of 12 pass, unidirectional, now at least it was even, but with a bit of banding...

Tried to hit "function" while printing, and adjusted the feed on the run, -50 to +20, did not seem to matter a bit, tried different increments, banding was still there.

Then, noticed that the light bands seemed to be in the middle of each pass, not between the passes.

Printing on Avery cal, heat 45/45, FlexiPro7.6

Ideas appreciated!

 

[ChicagoGraphics]

Try printing in 720x720 8 pass bidirectional mode.
Try using the heat settings at 45/40
Do a cleaning and test print, make sure all your jets are firing.

 

[MobileImpact]

banding can be a million different issues, and not always a printer issue. Media, profile, rip, environment, heat, humidity, dust, ink types, all play a role in your final output. If possible, in the future, post a pic of what's happening and we may be able to point you in the right direction.

Kevin

 

[ColesCreations]

Of course I should have mentioned that the test print was perfect. Is a cleaning cycle necessary if the test print is OK?

The profile I was using specified 360x540.

I will try a different media, and play with the settings.

Also, when I print the 2 grey bands for feed calibration, when it's perfect at the ends, it leaves a gap in the middle, and when reducing 2-3 points it closes the gap in the middle, and overlaps at the ends... How is THAT possible? Almost like the spray pattern is narrower in the middle than on the ends.

Anyway- not ready to chuck it yet

 

[Ken]

Congrats on the JV3! I have heard great things about that system....
Go to higher resolution.
Ken

 

[eforer]

The media comp problem in the middle only is a little odd. Are you using the take up reel, is that sucker over torqued? That could potentially, depending how you fastened the media to the roll core, distort the center of the material and cause the phenomena your describing.

Generally, media comp issues are related to not having the media square to the pinch rollers, but that results in problems occurring at one end of the scan and not the other, not problems in the middle.

Also, are your heaters heating uniformly (I've seen used machines where there are sort of deadspots) if its hotter/cooler in the middle of the media, it could account for the problem your having. A good test would be running a media comp test with the machine completely cool and seeing if the spacing is uniform.

 

[iSign]

Also, when I print the 2 grey bands for feed calibration, when it's perfect at the ends, it leaves a gap in the middle, and when reducing 2-3 points it closes the gap in the middle, and overlaps at the ends... How is THAT possible? Almost like the spray pattern is narrower in the middle than on the ends.

that sounds pretty scary.
I remember one of the techs who worked on my JV3 did a complex testing process with several rows of a 1/2" lines repeated about every inch or so, and as the printer advanced the media feed out, laying down row after row... there were some that aligned, & some on either side of the aligned ones that grew progressively further out of alignment. this adjustment is something I never learned to do, or what exactly it was... but I wonder if it was done to your machine?

 

[ColesCreations]

These lines were printed without the take-up reel, and with good slack on it when the reel was connected, so no, not too tight there.

Also, we purchased a mask.... Charcoal filter, these SS2 fumes are NOT healthy!!! Yes, the unit is vented directly to the outside of the building, both top and bottom, I hope the rest of you guys are careful, it's almost like spraypainting a car... And no-one sane would think of doing that without a mask!

Thanks for help, will look into these things.

 

[eforer]

In addition to the machines built in ventilation you have to vent the room. We have a special print room with a window to monitor the prints. The room is 10'X20' and we have 2 500 cfm fans venting the room out of the building. If you think SS2 is bad, try triangle. The ink is vastly superior, but the fumes make the ss2s seem mild.

Also, the little lines printing thing is the part of the #printadjust menu, which is normally locked out for the user and made accessible for technicians. To do a full calibration, you'll need 40 linear feet of material, a loupe and about 4 hours. This needs to be preformed after you replace a head etc. Its not super fun. My machine is "bypassed" so I can get to the "#" menus all the time, the sequence for a normal machine can be found in the maintenance manual. This manual can be download form the Mimaki Yahoo users group.

 

[GK]

Are you using the profiles that came with the machine? I can't stress enough how many times a lot of the profiles that come with the machine will not print correctly. We bought identical machines. One printed perfectly with the stock profiles the other one printed terribly. Custom profiled them both for all the medias we use, now they run perfectly.

 

[eforer]

Profiles wouldn't effect this, its some sort of calibration problem. The fact that his media comp is irregular in the center of the scan only is really bizzare. I agree though that out of the box profiles can often be awful and that no two machines work the same.

 

[MobileImpact]

Of course I should have mentioned that the test print was perfect. Is a cleaning cycle necessary if the test print is OK?

The profile I was using specified 360x540.

I will try a different media, and play with the settings.

Also, when I print the 2 grey bands for feed calibration, when it's perfect at the ends, it leaves a gap in the middle, and when reducing 2-3 points it closes the gap in the middle, and overlaps at the ends... How is THAT possible? Almost like the spray pattern is narrower in the middle than on the ends.

Anyway- not ready to chuck it yet

Print at 720x720 8 pass bi-directional. If You need to jam the quality switch it to uni. 99.9% of our printing is done in this mode.

 

[ColesCreations]

Hi.
Found another profile to use w/ 720x720, prints look good.
As for the "blinds"-effect- along the center of the prints were a set of street-lights......... And water reflecting..... The silly canned icc-profile made the reflections from these lights brighter.... I should have tried to turn the print 90 degrees, the lines would probably still be there, just the other way...
As for the grey calibration print, it's just a tad narrower in the middle, as I mentioned, a couple of points, not really noticeable on the print.
The learning curve is steep, getting steeper