Trapped air in PK cartridge Epson R3000

[pharmacist]

I having problems with removing trapped air inside the tubing system of the Epson R3000. I accidentally pushed ink into the PK line, because those crappy chinese cartridges still says I have enough ink in my PK cartridge, but it was actually completely empty, so the PK ink channel and the corresponding PK cavity inside the print head is full of air.

Could anyone help me with this problem, because I already tried several cleaning cycles and switching between MK and PK a few times, but no success.

 

[Ink stained Fingers]

did you try WIC Reset, that software typically offers a command 'Ink charge'
which pulls a lot of ink through the tubes. Be aware that this command raises the
waste ink counter significantly - just read the level before and after.

 

[pharmacist]

I should have used this before. It uses less ink after 8 cleaning cycles. Problem solved. I have the old reset utility for the Epson r3000. The amount dumped in my waste ink container is however hallucinant about 50 ml.

 

[mikling]

I would have suggested an alternative method which is using a syringe to pressurise the channel slightly while performing a head cleaning or sealing the vents on the other channels but I was late here.

Sealing the other channels air vent holes mitigates the ink flow from there, thus concentrating the vacuum during the head cleans to the PK channels allowing higher volume from that channel. You might have to perform another couple of cleans after removing the vents because some of the retained elasticity due to some trapped air in the dampers and cartridges pulling back after a clean causing air entrapment.

The other aid is to simply gently inject air pressure through the air inlet path during a cleaning cycle.

Now on the pressurised models like the 3800. 3880, P800. The situation is vastly different. Because the channels are all under air pressure some magic happens. Remember that while these machines are operating, their ink channels are under pressure. So what stops the ink from leaking out? Surface tension of the ink at the nozzle. That means that there is naturally more resistance to flow when the nozzles have ink as oppose to when the nozzle does not have ink. So when a cleaning is performed, any nozzle devoid of ink will have less resistance to flow than if it had ink. That essentially produces more pull and and also push force to the empty nozzles and concentrating the forces there!!!!!!!

The biggest problem with the piezo printhead is air entrapment and introducing air into the nozzle space. Again, this pressure mitigates that because it keep the nozzle pressurized and minimizes the potential of the meniscus at the nozzle exit to tear and break down and entrap air when reforming.

There is no secret why this class of machine have proven so reliable in operation as compared to previous models..it is because of the pressurised ink system in the machine. The pressurized system also leads to better ink droplet detachment and more consistent droplets as well.

To prove it, I had performed something stupid. When I installed my P800 decoder I took a shortcut and did NOT top off my carts. I totally ran the PM channel dry when I got busy and forgot about what I did.
I refilled the cartridge, primed etc. One strong head clean and the printer had restored the complete channel including refilling the tubes. Magic.

Having all the K3 Vivid class Epson machines in my printer army, all using the same ink, unders identical operating conditions I have been able to objectively compare these aspects as well as their print abilities. Unfortunately I lost my R2880 due to a mainboard malfunction two winters ago. But prior to mainboard failure, the R2880 was not as reliable as the R3000 in nozzle checks. This machine required about once to twice a week useage to remain perfect. The 3880 P800 can go months, really.

As long as I run my R3000, about once a week or even sometimes every couple weeks, this last winter it has been perfect. No head cleanings required at all. The previous winter I had not practiced that and left it unused sometimes for as much as four weeks or more. The situation was different as it frequently required head cleans to get going again. The P600 does not require as many head cleans despite using the same construction as the R3000. I think I know why. Epson engineers changed the way they use ink in the P600. They now use more of the darker ink in their nozzle patters than as compared to the R3000. Same story for the3800 3880 versus P800. In this situation they are able to improve the print quality and more importantly for the P600 reliability as well. I think they realized that the most frequent nozzles that were not active after a nozzle check were the darker colors which were infrequently used or maybe it was simply fortuitous that the improved dot patterns simply created a side effect of better reliability?

Hmmm....