Falcon Jr Tiny verticle lines at 33" to 34"

[hapycmpr]

101rs My falcon Jr has had this problem since I bought it a few months ago. I needed a new color head so after I installed it two days ago, I am now striving for perfection. -Quit laughing- The head made the prints amazingly gorgeous but I still have these little black marks appearing between the 33 to 34 inch left side. I have watched as it prints and it is not a mark that is being caused by anything under the roller as it shows up as the print head goes by. Also if I print something narrow, say 30" and the head does not pass by the 33 to 34 inch area the marks does not show up. Since I have another Falcon Jr in the garage, I tried swapping out the back and colored print head cables, the data cable from the touch pad to the mother board. I talked to a sign shop tech/production manager at a shop in the city and he told me he has two Mutohs a Rolland and a HP latex and he has the same problem with both Mutohs. Same lines different models. So I am not alone with my problem but also not alone in this printing world. I have a secret weapon, it is the Signs101 subscribers. I have scanned the lines and blown them up to 300% and have sent pictures. Any Ideas?

 

[Kev41]

You need to clean the encoder strip, hope this helps

Kev

 

[hapycmpr]

Encoder strip

I have cleaned the encoder strip but tell me if I am doing it correctly. I am using 70% alcohol and using a lint free towel to go back and forth on the clear plastic strip on the very top of carriage. I have never used cleaning solution but if needed I can use something stronger than alcohol. Is the spot where the lines showing up on the print in direct correlation with where the encoder is dirty? Also can you give a brief discussion on what the encoder strip purpose? Thanks in advance!

 

[hapycmpr]

Encoder strip

I see others have had this problem. Maybe time to switch out the encoder strip. After another clean I get a error 74 http://www.signs101.com/forums/showthread.php?89409-What-are-these-marks&highlight=mutoh+encoder

 

[hapycmpr]

Endoder strip replaced

OK so I switched out the encoder strip with the one from the Mutoh in the garage and I am getting the same lines at the same exact place on the print. This does bring up a different question for the future. Can the encoder strip be installed upside down and still work? This would make it convenient if the strip ever failed or got scratched you could reverse it and get some more life out of it. Has anybody done that?

 

[CS-SignSupply]

Possible you have a short in the long print ribbon cables that when flex at the 33"-34" area shows up.

 

[CRD]

The encoder strip or wheel makes the head or drive shaft go to their correct position.
An optical sensor reads the black stripes on the strips or wheel.
If these stripes are gone it does not know correct position or state anymore.

As Bobby said this is not encoder problme.
Print some small horizontal lines 40" wide at 2 "interval.
Does it happen too?
If it does the main flatcables from head board to main pcb are gone.

Paco

 

[hapycmpr]

Flat cabels or "Y" cabels have been replaced

I have just now replaced the Flat cabels or "Y" cables as Mutoh calls them. I have also replaced the short 6" head cables. Problem lines remain. Any other thoughts on this?

 

[gregwallace]

Is it possible that you have a glare from the light hitting the encoder strip? Just a shot in the dark. The lights from your room.

 

[hapycmpr]

Kill the lights

Ok I tried killing the lights and I still get the lines.
I tried printing other sizes and as long as the print is at 33 to 34 inches from the right edge it still prints the lines.

 

[CRD]

Are these lines also through the print if you print 38"? What is its location compared to the print.
The pictures only show the lines not the location compared to the printpout.

Paco

 

[hapycmpr]

Location

Yes the location is always the same if the print is larger than 33" up to 38". Less than 32 there are no lines. Greater than 33" they will show up between the 33" to 34'' area.
--James-

 

[gregwallace]

Try slowing down or speeding up the carraige speed if possible.

 

[CRD]

MR. camper,

I know it is always at the same position.
But the relation to the print I like to know.
If you print a 38"withd x 1 '' height outline does it print the lines through the print itself.

Paco

 

[hapycmpr]

Success No More Lines

Information from Doug Williams at Fellers on where my lines are coming from. Doug has been working on these for 25 years and has forgotten more than I will probably learn. Here is what he told me.
Since the lines are always at the same location it tells us there are three scenarios that could cause them.
1. The “Y” cable or umbilical cable as Doug called it, can get a kink in the wire so as it makes the curve at the 33 inch mark, it sends a charge to the piezo head making it fire just lightly to make the lines. This was already discussed by Paco and so I replaced the “Y” cables with no change of status.
2. The next is the carriage traveling on the rail. If there is any vibration at all, it can also make the piezo head fire lightly causing the lines. So if there is some debris at the 33 inch spot on the rail, as the carriage travels and bumps over the debris it can cause a vibration making the piezo head fire and make the lines.
3. The Third is that if the umbilical cable that has two cables, ink lines, an aluminum stiffener, and padding are not perfectly smooth while traveling, and hit on a screw head or the rail or anything that can cause a vibration, it will once again cause the piezo head to fire just enough to cause a thin line. This is what was causing my problem. The aluminum stiffener as Doug called it, had a dimple bend in it and every time it got to the 33 inch mark I would hear a noise like denting in an aluminum can. I never thought this would cause any problems so I ignored it. When I removed the stiffener and let it run with the cables and ink lines flopping in the breeze, no lines. So I traded parts with the extra Falcon Jr I have and once again I have a print with no ugly lines. Success! I guess any vibration on a DX2 head is not a good thing. Thanks for all that responded and got me going again.
Signs 101 is the greatest forum in town.
Doug Williams you a genius. Thanks so much.

 

[hapycmpr]

Paco's Question

Paco
Yes it did put the line through the print. Thanks!!

 

[CRD]

Thanks for the update and extra info which for others will be valuable too.

Paco