Pictures in this document are reduced resolution. Click pictures to get hi-res picture.
"Up / Down" corresponds to natural cart position - same as in the printer.

An opened C6578 , 19 ml.

The carts, resp the foam has been just half filled.
After fabrication, months of transport and storage, and more months of use the foam hasn't distributed over the foam. Why ??    Is it impregnated at the upper half ??

The cart has had 7  (19/3) ml per colour. From that will remain about 2ml, when the cart stops printing. This 2 ml arent accessible.

Given this, the refill amount should not exceed 5-6 ml, if a status similar to the Orginal is planned. (See more about that in refill procedures).

In the picture the pads are ripped of - seen in the upper left of the picture.
 

The foam lets a room of about 2 mm free ( near nozzle plate).
This room contains no ink, all ink is held inside of the foam.
 

Under the foam is a fine metal mesh - a sieve??
The foam is lying sideways on the sieve (blue and yellow), the sieve is upright. ( For red - middle chamber - this is different).
For blue and yellow it is hardly possible to damage the sieve with the needle.
(Pictures with needles see below )

The Sieve is no filter, it  inhibits air passing !   Thats the one and only task, for filtering puposes it is not fine enough.
The Air is inhibited from entering the nozzles, since air bubbles disturb printing proces !!

I call the room over the sieve the foam chamber, the room behind the nozzle chamber, due to obvious reasons.
 

The middle chamber looks different, the sieve is horizonal and situated higher.

This sieve can be easily hurt if the needle is long enough, and you'd better care not to do this : it kills the cart !!

Near the sieve the wall looks different, its more roughness present to improve the ink hold contact to the wall.
 

More Details: The sieve is the "red" sieve, the room behind that is the "yellow" nozzle chamber - its sieve has been broken off.
Deep down in the yellow chamber is an oval opening - the final channel down to the nozzles.
 
 

The notzzle plate with the underlying chip. The thin plate is glued to the chip - quite a delicate construction - and sensible.
Dont damage that arrangement ! (Especially when opening the filling holes )

click picture for more details

The middle picture is in the same position as the left one, for better understanding.

The right picture shows the spaces of the "nozzle chambers" - as I call them. They are alway filled with ink - completely - otherwise the cart doesnt work. (This is the area where the dreadful air bubbles really cause trouble!). The rectangles - and the arrows pointing to - mark the sieves, just for clarification.

 
 

Addendum 8.5.03 These pictures are made as warning against puncturing the sieve - no misunderstanding, please! Of course the sieve shall not be punctured anyway - as mentioned in the text !

Why does puncturing the sieve kill the cart ?

The one and only task of the sieve is preventing air from going through. This is done by capillary forces of the innk in the sieve. When the sieve is punctured, this is a hole for air - and the capillare force will absorb all ink - by contact to the rest of the sieve.

Punctured carts can be easily recognized from outside. Given the remaining ink in the lower norzzle chamber is used up or printed, its hardly possible to get ink out of the nozzles. Neither by blowing, nor by touching a towel.

( That is different to the "normal" problem where ink gets out but the cart wont print.)

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Statements  :

- The foam chamber never contains liquid ink. All ink is absorbed and held by the foam. The foam delivers ink to the sieve. but slowly.
- The nozzle chamber ever contains liquid ink - it has to - otherwies the cart wont work.
- The sieve is the separation between both. Air can't pass it, as long there is enough ink.
- The foam delivers ink to the sieve, and to the room underneath, as log there is enough ink.
- if the foam is "empty", air is drawn through the sieve - and the cart is dead .

Because : After refilling this air cant be removed  !
The sieve does its work again - preventing air form passing - in both directions !

(OK due to later reserach, , here on this site you learn about two methods of removing that air.  Vacuum works, and the   Down-Under method works as well. But this are the only possibilities !!!)

Shaking, knocking, blowing - nothing works. The sieve cant be penetrated by air ( if enough ink is present ).
The only possible way is through the nozzles, and that works only as described in the down-under method.