For flawed heads that I stored I do have some questions on refilling them. I tried to refill just the LG side of a too light PK LG head by using a salvaged cartridge connector plug that was inserted in the end of a PE tube of almost 150cm long filled with LG ink. My thought was that the additional pressure of 150cm ink column would be enough to get the ink in. It did not. I know I need a 10 meter column to get the same pressure difference a complete vacuum would give but is that much needed?
That double funnel type, do you need to fill both sides with the respective inks in order to get it all working? I understand that the syringe vacuum applied is all over the head nozzles and can not select just one ink channel but if the input side pin of one channel is blocked with halve an orange stop (halve the orange twin type that comes with a new head), would that work to fill the other side? It would be nice to just refill/reflow one ink channel, especially for heads like the Chromatic Red / MK where MK ink got into the Red side, pulling enough Chromatic Red through would be better than trying to get rid of it by printing red prints.
Hi Ernst, I'd be interested in trying a softer seal material like you found. I was surprised that the ones sold by LPS Computers are rather hard. Maybe it still works, I don't know. What I found was that the heads sit higher in the printer carriage with those seals, like 1~2 mm. That makes me wonder about the effect on print qual. Also one of the heads gets rejected frequently (usually after a power reset) and wants to be reseated. I think it's not making proper electrical contact because of the seals. I cut the seals on that head slightly smaller but it's very difficult to get a clean cut surface on them. It seems to have fixed the head rejection, but now I doubt the seals work correctly because of the rough cut surface. I ordered some more from LPS but with shipping costs to Canada these things are ridiculously expensive, so interested in finding a better option to make them.
Omg yes I think there is no way a cartridge will fill with static pressure like that instead of a vacuum, at least not within our lifespan lol. Those nozzle holes are nearly microscopic. Pulling the pump syringe on these requires a lot of force just to move the plunger a little bit. You just hold the pressure as best as you can until it subsides enough to pull a little bit more. It is not a fast process. If you release the plunger it will actually snap back to lower position, there's a lot of suction. The stuff appearing in the syringe is a very bubbly foam, it's a lot of air. Some of that air appears to be suction leakage around the nozzle cap rather than air just from the printhead. It takes some practice to get used to it.
I thought about making a non-funnel method to refill the head directly from the printer head carriage with some tubing and connectors for the ports, to help reduce ink waste. But I haven't tried that experiment yet. A cleaning method between colours would need to be sorted out.
Yes the funnel method needs ink on both sides, otherwise the other side would just draw air into the printhead. I thought about a nozzle cap that covers only one side, but the 2 rows are so close together, and the suction is so strong, it might not be possible. I also thought about a plug over the inlet pin on one side, but then that would create a very strong vacuum inside the head that might break some things. The heads have delicate-looking bladders/bags in them that are connected to atmosphere through vent ports on the top of the head (to compensate for atmospheric pressure change I believe). Applying vacuum to a head with the inlet pin blocked might cause those to over-inflate and cause damage. I also worry about the seals between the ink compartments and printhead top that a strong vacuum might possibly pull out of position. Maybe it would be okay but it's difficult to know, and can't see if there is damage inside afterward. So it seems that accepting that there will be some ink wasted in the process is just the cost of saving the head (plus other ink, paper, etc in fighting print quality issues with an "airhead").
So in your MK-R example, just put ink in both sides of the funnel. Odds are there is air in the MK side too and will end up drawing ink in to both sides. The MK contamination into R is mostly at the nozzle itself I believe (and the R into the MK side, I've seen both...), so it should clear up when the fresh ink is pulled through the head.
Also make sure to check the error codes/status in the service manual first to make sure then printhead isn't fried, to avoid wasting effort refilling a dead head (like I did lol!).
