Sealing the refill hole BCI-6 BCI-3

[Nifty]

UPDATE: I just refilled all of my cartridges in my IP750 and using the screw / o-ring combo went beautifully!

 

[pebe]

Ive recently bought a Canon IP4000, and Im thinking of refilling when required.

I followed the whole of this thread and thanks to Grandad35s exploded view of the cartridge I now have a fair idea of its construction.

I noted the problems nifty-stuff.com had with arrowjet carts when there was apparently some sort of vacuum created in the ink reservoir, and that set me thinking. There appears to be no air bleed for that tank, so I wondered what replaced the ink in the tank as it was used up. What prevents a vacuum there? Is it perhaps a small amount of alcohol added to the ink that vaporises easily?

Theres probably a very simple answer, but Im curious to find out.

 

[fotofreek]

Pebe - There is an air vent in the Arrow carts which is covered with a label when you take it out of the box. A tear strip at the end of the cart (over the sponge area), when removed, is supposed to expose the end of a "maze" - an air channel which leads to a small hole (air vent) over the sponge area. The label portion that stays over the vent and most of the channel helps to prevent evaporation of the ink's water base. I just unwrapped a dozen Arrow carts that I purchased early this year but had not used. I am using MIS bulk ink and decided to purge the carts and refill with MIS inks. I found that some of the Arrow carts had too much adhesive under the label that may have partially blocked the air vent channel and prevented proper ink flow. I will probably strip off all of the labels, clean out the channels to be sure that there is adequate air flow, and re-cover the channel and vent hole - except, of course, for the last turn of the channel .

 

[pebe]

Thanks, fotofreak. I can see how the sponge chamber is vented with the labyrinth, but how does air get into the ink chamber above the liquid ink as the ink is used up? On the OEM catridge, there does not seem to be any vent path to that part of the cart.

 

[Grandad35]

Pebe,

On a new/freshly refilled cart, the first ink to be used is from the sponge chamber. As the ink level in the sponge chamber drops to about 1/2 way, air can reach the top of the vertical grooves in the sponge side of the wall separating the sponge and ink chambers. As the sponge tries to pull ink from the ink chamber, the slight vacuum in that chamber is sufficient to pull air down the grooves and into the ink chamber, allowing a little bit of ink to flow out for each air bubble that enters.

If you ever do a lengthy printing job (say 5 - 8x10 sheets), pull the cart with the highest ink usage immediately after you finish - you will see lots of small air bubbles in the ink chamber. After a few minutes, these bubble collapse and this evidence is lost.

This is why the position of the sponge in the sponge chamber is so critical - if it is jammed tightly into the grooves, air can't get into the ink chamber and no ink can come out. I suspect that this may be the problem with the Arrow carts.

 

[pebe]

Grandad35,

Thanks. You have explained it very well. I understand now.

 

[hpnetserver]

Grandad, pulling a cartridge out of printer immediately after a heavy print job is probably not a good thing to do. The print head is probably still pulling ink downward. If the cart is taken out air will be sucked in. It will cost you one or two clean cycles to suck it out afterwards. Just a thought. When there is a blockage in the cartridge what will happen next is air will be drawn into the print head. The air in the print head will cause a clog next. Do I understand this correctly? Just a thought.

 

[Grandad35]

Hpnetserver,

A few things to consider:
1. Pulling a cart immediately after a print job is the same (IMHO) as replacing a cart that goes empty in the middle of a large print job. I do this all of the time without incident. I have never seen anyone recommend waiting for a certain time before installing a replacement cart. It is also true that an extended cleaning cycle is automatically run when any cart is changed for the purpose of removing any air that might have been introduced during the change.
2. There are a number of people who periodically pull their carts to "top off" the ink when any of them is running low. This will not trigger the extended cleaning cycle (AFAIK) that is run when a cart's sensor goes from "empty" to "full".
3. It may take some time for the ink in the sponge to completely equilibrate after printing, but the print head itself is hydraulically full, and it pulls ink from the pickup immediately as it uses it. If it isn't free to immediately pull in as much fresh ink as is used, you will see banding because the print head is starved for ink. Therefore, in a properly operating printer, there shouldn't be any residual vacuum on the ink pickup after printing stops.
4. If you are concerned about air getting into the ink channels, just run two cleaning cycles before printing after the cart is reinstalled (as you said).

 

[hpnetserver]

Well, pulling a cartridge immediately after printing say 20 full sized photos is not the same as pulling one when you suddently find an empty tank after turning on the power of the printer first thing in the morning that needs to be replaced. If you let the printer to reset for a minute I would say there should be no problem whatsoever. But pulling one immediately is probably not a good idea. I agree, if you invoke a clean cycle after changing a cart then there should be no issues to pull a cart right after a big print job.

Well, pulling a cart right after a big print job may not immediately cause a problem. But considering the fact a lot of people suddenly realized that their printer got a clog by surprise this may be something to think about. It may be OK most of the time but it needs just once to leave a problem to the printer.

I may be wrong. It's just a thought based on physics. There is nothing wrong about physics. It's whether physics may apply to this case or not is the question. I am very careful in dealing with my cartridges on my ip8500. I don't remove them without a good reason. This may be a factor contributing to the fact that I probably have only invoked less then 20 or so clean cycles to my ip8500 since I bought it in January.

 

[gamarlin]

I found this site (http://www.newark.com/NewarkWebCommerce/newark/en_US/endecaSearch/partDetail.jsp?SKU=97H7866&N=0 ) on Google search and have ordered 10 to try. They are about $0.57 each plus $5.00 second day ship. I will post my appraisal of them when I receive them.