Terrible Print Quality - Need Help Troubleshooting

[x126]

"Player" You might be EXACTLY RIGHT regarding that!! - I did not put them back and they very well could be the cause!! I'll be working on cleaning them out and returning them to where they belong.

"SightLine" I agree and I am just as confused - but with the cleats re-inserted in the tubes (as per Players observation) just before the ink travels back to the pump ( Shown in inkflow pic), could create a siphon effect.

I'm excited to say "Siphon" because I just heard back from Graphtec and he explained that the system is a gravity system that works like a Siphon!

Off to do some testing, I'll keep you posted!

 

[StopSignGraphics]

I'm really confused by the photos. What purpose can the dampers serve if the ink goes through a 6 way fully able to bypass them? In all printers I have seen the ink must first go through the dampers then into the heads. It appears as though there is a 6 way fitting which allows the ink to really just bypass the dampers.

Agreed. Very confused by the picture especially if it's a syphon system, being gravity fed it wouldn't feed back to the ink tank.

I used to work on some larger Nur printers, the pumps would pump ink into a manifold and the manifold would then gravity feed ink into the print head. It had a float switch that would maintain the ink level, over flow ink would be pumped back into the ink reservoir tanks. I suppose it's possible you could have something like that.

You replaced the lines, are you sure you got everything back correctly. Because it does appear from your diagram the ink can totally bypass the damper, which doesn't make sense. Even if you got everything back the way you found it, that doesn't actually mean it's right either. Someone could have screwed up the plumbing before you ever bought it. Any chance of getting a manual for the thing?

So you got the six way valve, 3 dampers with an inlet and outlet per each color. Is it one six way valve per print head? How many slots for OEM ink cartridges does it have for each color?

~Chris

 

[x126]

I took photos as I disassembled things and replaced them as they were (with the exception of that one little cleat that "Player" mentioned )- you might be absolutely correct about someone screwing it up prior to me.

They do have manuals for it online... ( I have referred to the manuals often but they are'nt the best manuals either)

Service Manual: http://222.146.7.157/support/manuals/JS500/JS500-UM-251 (01-9370).pdf (Diagrams are around pg 200)
User Manual: http://222.146.7.157/support/manuals/JS500/JS500_UsersManual_v2(NP).pdf

Back to the cleat... they are now back in place - I added a photo of what they look like below. They are very small metal pieces that fit in the 3mm tube that have a 1/32" hole. I updated the ink flow pic (in green) to show where they were removed from and replaced.

I did not put them in after replacing the tubes because I thought they may restrict the ink flow, however after cleaning them out from being clogged and putting them back, it seems the air getting to the print heads has been considerably reduced. As far as I can tell for now at least.
Updated Inkflow with "cleat" locations

that six way valve goes to 3 print heads and 3 dampers per color and it has four slots for ink CMYK

 

[player]

I take PayPal.

Hopefully the air reduction is not just an accident. I don't know why the ink would bypass the dampers either, if that's what's happening.

Maybe you could find out from Graphtec all the dealers that were around when your printer was current, and start calling them until you find someone who was servicing them back in the day.
You may even find some OEM parts in the process.

 

[x126]

I did make a contact at Graphtec that's been pretty helpful so far, although it took a while to find someone.

You guys are right about the ink bypassing the dampers, I dont get it either...

I'll work more on making sure there is no air in the lines tomorrow - so I can move on to what is making the black ink fade out after it prints a few inches and whatever's is next.

Here is the result after ink was drawn to the print head with the cleats installed.

 

[player]

Are you sure your homemade cleaner is not eating plastic or rubber parts? Or the heads?

 

[StopSignGraphics]

I looked at the manual. It's starting to make a little more sense.

You don't have a dampers you have a filter and serge tanks. I'm kind of thinking that dampers and serge tanks are probably aren't the same thing but I don't know that for sure.

The best i can tell from the diagram, ink flows from the pump through the filter. Then it flows to the 6 way connector. Ink then will flow to the print heads but you only want so much pressure on the print heads so they've added the "cleats". The cleats are probably nothing more than a metal cylinder with a small hole in the middle. Excess ink will flow through the "cleat" into the serge tank. The reduced opening in the cleat only lets a little of the excess ink flow into the serge tank so it maintains a constant pressure on the print head. There may have been some sort of check valve or something like that in the original "serge tanks" that restricted the ink to only flow one way. After the serge tank, the ink get pulled through the system by the pump. It get's recirculated into the ink circuit and starts the process all over again.

Dampers may be able to serve the same function as serge tank but you should probably try to confirm that they operate the same way.

So when you tried operating the printer without the cleats, it's likely you could have pulled air through the printhead into the system.

According to the manual, you should be able to use a syringe on the outlet side of the print head and syphon off the air. Looks like that should be pretty straight forward.

If you are still getting air into the system, check all of the f joints and t joints. I've found hair line cracks that are nearly impossible to see but are still large enough to allow air into the system.

Good luck,
Chris

 

[x126]

"Player" According to artbot and a few threads related to cleaning solutions, the mixture uses the same ingredients as most manufacturers. Just to be sure though, I soaked tubing in it for a week without any issue.

http://www.signs101.com/forums/showthread.php?65904-Cleaning-fluid-question

"Chris" Thank You for taking the time to review the manual and explaining the difference between Dampers and Surge tanks, while they may look the same they do play considerably different roles in the flow of ink. Thank You for pointing that out!

After getting an email back from the graphtec tech, he explained that the ink system works like a siphon. I asked him if the pumps are supposed to kick on during printing and he explained the the pumps WILL NOT turn on during printing only during a cleaning via the control panel. He went on further to explain the the ink system works like a siphon similar to siphoning gas. His words "Think of it as when you borrow gas from your friends gas tank using a hose, once you have suction it will flow - but it you make a hole on that hose the liquid will return."

So, now with the new understanding of the Surge Tanks, cleats and ink flow system, I am going to have to closely look for any possible air leaks since that could be the only cause of ink not consistently flowing to the print head.

I'll report back again shortly and again THANKS for the help

 

[x126]

Just stopping in to post the results for today. Not perfect for sure! BUT, considerably improved from the beginning.

Here are two pics of what the results for today produced.


The Cyan seems to be printing well, The Yellow isnt to bad, the Magenta and Black are giving me the most trouble.

Tomorrow, the black and Magenta print heads with be getting a sonic bath.

I did make some adjustments such as: reduced & increased ink volume, Lowered the print head temp and as per a suggestion from graphtec reduced the (EF) voltage value - all of which seemed to help a bit.

Based on the pics - if you think I should try something to improve the result - I'm all ears.

And again, just want to say thanks

 

[heyskull]

I didn't even realise this machine existed!!
When was the manufacturing date as their is very little info on it anywhere?
It seems a very over complex machine especially having 12 print heads and by the videos I have seen of it in action very very slow print speeds.

I do not want to sound harsh but to be fair I would only continue reviving this machine if you are not in a rush and fancy a challenge.
And then only if you have very very patient customers if it is being used for a commercial purposes.
Parts are going to be either unobtainable or very rare, unless shared with other machines.
I thought it was challenging enough playing with an old Mimaki JV3 but this looks like from the previous decade than my machine.

SC

 

[SightLine]

Actually these are newer than a Mimaki JV3. The JV3 if I remember right first came out around 2003. This machine came out around 2007. Its a very obscure machine though - I don't think many of them were sold. It is quite possible Graphtec just OEM'd the machine from some other maker and you might also be able to find more info on an identical but branded different model. No idea though.... its not going to have the print quality of a Epson head based machine regardless - those heads smallest drop size if in the upper 30pl range while the Epson piezo heads is below 10pl. Still - if the machine can be made to run and run right it probably is a very capable printer.

 

[x126]

You pretty much nailed it SightLine the JS501 is Graphtec’s 2nd model. they first sold the JS300 series, both the 300 and 500 were former attempts at the printing market. The machine is about six years old and was primarily sold in the Latin America Market, Matter of fact, I bought it in Miami, can't get much closer to Latin America than that and it is a rebranded machine, I believe its interchangable with an Infiniti.

I really wanted a large format printer just to do fine art, but came across this machine. Since I have a background in graphic design, tradeshow display construction, product design and other related stuff, I thought the possible applications could lead to some interesting things.

Do I like a challenge? HELL YES! But I think I bit off a little more than I can chew, but thankfully I found Signs101.com and some very helpful people. And once again I'll say THANK YOU! for the insight and knowledge.

Today... I planned on Sonic Cleaning the Black and Magenta Print heads. Overnight I received some current software from graphtec - I was running their GPU Setup 1.0.0.1 now I have V 2.60 and Also now have graphtec's "Ink Curve Software" which I did not have until today.

I'll intstall the updated software before I remove the heads for cleaning to see how much effect the software has on improving the output.

 

[x126]

Result after Magenta Sonic bath

 

[player]

Have you found a source for the heads? If so how much are they?

How are you pumping the cleaner into the head?

 

[x126]

There are a few sources for the printheads online and the average cost is about $250 per head.

I am using one of the older pumps that I replaced, I setup a quick and easy sonic cleaning system based on information I gathered on youtube.

Currently one of the things I am noticing, is that only 2 of the 4 colors work at any given time. When I run a test print, everything starts off well, then about 1/2" into the the print 2 of the four colors start to fade out. Whats odd about it is... that the 2 colors are random

hmmmmm any ideas on what would cause that?

 

[x126]

Oh also, does anyone have a source for the plastic connectors and clips that pinch off the lines?