Intermittent Bandining Problem - Mutoh Falcon II Outdoor

[Graphics2u]

The last week I've been having issues with banding just all of the sudden happening. Kept thinking I had nozzles not firing but that wasn't it. (I do have a couple not firing but they never have, and this issue is new) So I started playing around with the step adjustment an had to decrease it by -1.1% to get it to look decent. But I've never had to do that before. Yesterday I went back to my original setup and it was working good for awhile. Then in the middle of a print it starts banding again! (Picture) You can see in the pic that it just starts all the sudden leaving a light colored banding line. The next 3 prints were fine then it did it again! Different file to so it's not the file.

Any Ideas? I know not too many use Falcon II's here but maybe something similar has happened to you.

Thanks

 

[Digitall]

We had it happen on our vp540 and went through all the normal troubleshooting. It ended up being the roll of material was not feeding smoothly through the pinch rollers so all we did was make slack in the material and it stopped, totally Something to try .

 

[Color Dude]

Did this problem stay consistant throughout that job?

Did the next 3 jobs have solid coverage like this job did?

Do you notice it just being in one specific color (ie reds, oranges, etc...)?

The F2O machine has a feed calibration procedure that needs to be set every once in a while. Those machines are very dependent on feed settings and tension.

I was working on a Toucan LT not to long ago and was having a similiar issue. The print would start out fine and then approx 1 1/2 - 2 ft into the print severe banding would appear. Cancel the job and immediately send the same job again and it was fine and then about the same distance in same thing. It turned out being dampers were clogged up. replaced the Cyan, Magenta, and Yellow and viola!! perfect again.

Just something to consider.

Let me know the answers to my questions I may be able to help.

 

[Graphics2u]

Did this problem stay consistant throughout that job? Once it started it remained until the end of that print
Did the next 3 jobs have solid coverage like this job did? Yes, it was the same job and they worked good.

Do you notice it just being in one specific color (ie reds, oranges, etc...)? no, it's shown up in most colors.

.

I actually thought about the dampers. But when I would run a nozzle check immediately after it happening it would look fine. I even sent a couple jobs as CMYK separations to see if it was one particular color messing up, but they always printed good. It's like sometimes the feed adjustment just changes somehow. Feed motor maybe?

 

[Color Dude]

Well, think about this, do you notice it when you load a fresh roll of material and then maybe gets better as the roll decreases, or vice versa?

The reason the dampers were bad on the LT was the screens were clogged up and was basically starving for ink, the end result being banding. Like I stated in my earlier post, I would cancel the job and then immediately resend it. The problem was the ink would almost empty from the damper and then struggle to keep up from that point on. Once the printer stopped the dampers would fill back up and would print fine until they emptied again.

I would do the media feed calibration first just to eliminate that option. The feed motor COULD be getting weak but not likely the problem.

Does your F2O have the heavy duty media system on it?

 

[Graphics2u]

Well, think about this, do you notice it when you load a fresh roll of material and then maybe gets better as the roll decreases, or vice versa? It's happened both at the end of a roll and on a brand new one.


I would do the media feed calibration first just to eliminate that option. The feed motor COULD be getting weak but not likely the problem.

Does your F2O have the heavy duty media system on it? No it's the standard one.

The lines are so evenly spaced that it just looks like it's advancing the media too far and not that it's starving for ink. Because I would think that if it were the dampers there would be random nozzles that would start missing, which wouldn't give you the regular pattern that I'm seeing. Would it?

By the way this has the new firmware with the I2 weave pattern instaled also.

Is the media feed calibration in the service manual? I have one, I'll have to look through it tomorrow.

 

[Color Dude]

I dont think it is. I think Mutoh has a seperate doc on the calibration procedure.

If you dont have it, let me know..I do have it

 

[Graphics2u]

I dont think it is. I think Mutoh has a seperate doc on the calibration procedure.

If you dont have it, let me know..I do have it

Is that the Media Optimization Guide? MOG?

 

[Compilla]

The heater settings can contribute to this as well as the environment the printer
is in. Since most of the country is getting pretty cold now, the temperature of a company's shop is also cooler.
This means that the core temp of the media is cooler and the heat settings on the printer need to be higher.

 

[Graphics2u]

The heater settings can contribute to this as well as the environment the printer
is in. Since most of the country is getting pretty cold now, the temperature of a company's shop is also cooler.
This means that the core temp of the media is cooler and the heat settings on the printer need to be higher.

I have set the heaters up a bit. The biggest thing I hate is how dry it's getting. Got to get humidifier running in the shop again.

 

[jr_tech]

I've had this start to happen as well. It may be "chromatic banding".

Here's a link to something that RandyA posted:

http://www.mutoh.com/kb/entry/119/

My prints have 'lawnmower' bands in them, it looks like two different colors laid in each pass in bi-directional printing

It is typically a function of ink order

In one direction K goes down first then C then M then Y
In the other print direction Y goes down first then M then C and finally K

These can cause 'chromatic' color shifts and this banding is known as chromatic banding.

Temperature can help and sometimes solve the issue,
Lows temps allow the colors to mix a bunch before dry
Higher temps will try the droplets faster and help prevent mixing.

Chromatic will not be evident when printing uni
​

I'm going to have to try uni to see if it makes a difference.

-JR