I have spent a bit of time researching the best way to progress with this idea and think I have come up with a very simple workflow with very little cost outlay.

The workflow is based on a few proven concepts but is limited to use on specific Canon printers, namely the Pro100, Pro100S, Pro9000 and Pro9000 Mark II.  The workflow may apply to other Canon printers but I don’t have enough information to determine which ones.

I will post more details on what is needed when I have tested the full concept, but essentially it is just the equipment used in the previous posts re extracting the ink from the donor cart, but with a few modifications, plus some decent tape, such as aluminium tape.  Resetters are more expensive than I expected, for CLI-42 carts, so that is optional.

I am going to assume 3.2g can be extracted from a cart reported as empty by the printer.  See Reply Post #10 to see how much was extracted from my GY cart.  I have only allowed 2 carts to go to empty on my Pro-100, so the average ink used by those 2 carts was 9.67g.  The recoverable 3.2g represents 33% of usable ink in a new cart.

However, if we stop using and remove a cart when the low ink warning appears, and replace it with a new OEM cart, the removed cart would have approx 1.02g more ink to use before the “Empty” warning, than the previously mentioned 3.2g.  So typically 4.2g that can be recovered.  The 4.2g to be removed from the donor cart presents somewhere in the vicinity of 43% of usable ink in a new cart (ie. 9.67g).

 It is probably best to explain the general workflow at this point and then expand the detail.

Step 1:   When a cart gets to “Low”, it becomes a Donor, replace it with a new cart.

Step 2:  Just prior to step 3, extract ink from the Donor cart.

Step 3:  When the new cart gets below 57% remaining (ie. 43% used), the cart becomes a recipient. Remove the recipient cart temporarily replacing the Recipient cart with the Donor cart, but do not close the printer cover.

Step 4: Optionally, reset the chip in the Recipient Cart.

Step 5:  You have 10 minutes, after lifting the printer cover, to inject the donor ink, into the recipient cart, using the method proposed below, before the printer head moves back to the park position.

Step 6:  Swap the Donor and Recipient carts back and dispose of the donor cart responsibly.

I am working on the basis that each cart (except the very first) will initially be used as a recipient and when removed to become the next donor cart.  Part of the aim was to avoid the need to have heaps of empty carts hanging around for lengthy periods.

More detail and explanation of the 6 steps follows.:

Step 1 has already been discussed above.
Step 2 is intended to avoid storing the extracted ink.
Step 3 is where some of the research comes into play:  You will note on another thread I have looked at the accuracy of the Canon Ink Monitor(s).  The RUI ink monitor is more accurate and easier to evaluate.  Both ink monitors jump in 10% increments and will tend to show more ink than is present because of that fact.  This suggests that the earliest you should perform step 3 is when the ink monitor hits 50%.  You know at this stage you can fit all of the 4.2g of ink into the recipient cart.

On another forum, a member has been studying the optical ink sensor and has determined that this sensor is not activated until the ink has dropped below a certain level.  The author is not able to identify the exact point this happens but information he provided suggests to me, along with other members input, it probably happens at about the 80% empty point.  The significance of this information is that it is dangerous to refill after this has happened, without resetting the cart chip, since the “Low Ink Warning” will not occur before the cart becomes empty.  So to add a safety margin, assume it happens at 70% empty.  Hence the aim is to work in the range of 50% to 70% empty, based on the best ink monitor you have access too.  The RUI is only available if you have installed the printer as a network printer.

If you choose to use a resetter, then step 3 can be done anytime between 50% and 90% empty.  The 90% empty point coincides with the Low Ink Warning.

The reason for the temporary insertion of the Donor Cart in place of the Recipient is to avoid a purge due to a cart removal.  This was tested and found to work. You only have a total of 60s before a purge will be triggered, if no cart is detected.  The donor cart will stop the timer countdown.  Each change over should take less than 10s therefore using a total of less than 20s of the available 60s.

Step 4 is optional.  If you have CLI8 carts, the resetter is much cheaper and probably worth the cost.  If you donot use this option you cannot trust the ink monitor graphs, which will report less ink than is in the cart.  However, the Low Ink Warning is still going to work, according to information I have read.  Hence there is no danger you will run out of ink and damage the printhead.

Step 5 is where the ink is injected into the recipient cart.  The 10 minute timer (also tested) on the printer cover should be plenty.  If it looks like it may not be long enough, best to just remove the Donor cart and suffer the minor purge, otherwise, I believe, there is a risk that air could be pulled into the printhead, from the very empty Donor cart, with potential damage to the printhead.

There are several ways to fill/refill a Canon ink cartridge.  The most common method is called the Top Fill method.  It involves modifying the cart.  Another common method is called the “Durchstich” or German method.  It also requires modifying the cartridge.  Methods which do not require modifying the cartridge, use the exit port and there are different options within that method.

The method I am going to try is called the Freedom Method and the advantage is that I can use the same clip used to extract ink from the donor cart.  This method uses the exit port of the cart and involves creating a vacuum inside the cart using the syringe.  The aluminium tape mentioned above is to seal the air vent.  I will post more details when I have tested the method and hopefully confirming it’s viability for this application.  I expect it to be quick, easy and clean.  In a video I have seen of the procedure; a cart was filled from empty in about 30s, after the clip was attached and the vent sealed.  The steps above should include the sealing and unsealing of the recipient cart.

Step 6 is self explanatory.

I am awaiting delivery of a few items via post, which will allow me to start testing the Freedom Method using water in my empty Gray cart.  I then need a cart to reach 50% empty to do a full operational test.

The Freedom Method does not require any modification to the cart at all. You do not need to touch the top ball.  The ink enters the cart via the Exit Port.


This essentially does the same as “Ink Monitor Override”, perhaps with one advantage and one disadvantage.  It’s a long long time since I have  overridden the ink monitor on a Canon Printer, but here is my recollection of how it works:

When the printer reports a cart as empty and you ignore that and try to print you will be prompted that the cart is empty and to continue using it is potentially damaging to the printer.  However, Canon give you the option of continuing to use the cart, by overriding the ink monitor.  When the cart was reported as empty there are several warning lights in addition to the on screen advise.  One of those is the red leds associated with the cart start flashing quickly, another is the “Resume Button” on the printer also starts flashing quickly.  The on screen advise will ask you to press the “Resume Button” if you wish to ignore all the warnings.  This action will result in the ink monitor displaying a “?” against the overridden cart, in place of the red “X’.  In addition the cart graph will be completely white, instead of showing 5% remaining, as in the case of the normal empty graph.

If you use the cart with “Ink Monitor Overridden”, it will eventually start to run out of ink, but there is no way of knowing when that will be, and when it does happen there is the potential to damage the printhead.  If you are part way through printing an A4 or A3 when ink runs out, you won’t know immediately because that part of the print is not yet in view and you really need to stop it printing ASAP.

Removing the cart and resetting is much the same as Overriding the ink monitor,except the ink monitor is not totally useless but it is misleading.  The ink monitor will start at 100% full, drop to 90% full after the 1st ml or so, then drop to 80% full after the 2nd ml or so and I suspect around about this point is where it is likely to run out of ink and you have the same problem of potential damage to the printhead.

Transferring ink from a Donor cart to a Recipient cart removes the danger of damaging the printhead and, I believe, should yield more ink than continuing to just use a cart reported as empty.

I agree that extracting the ink took a bit of effort in my initial trial, but I hope my revised equipment will improve that significantly.  Refilling is frankly “a piece of cake” (is that a globally used term) using the Freedom Method, from what I have seen and read.  I have not tried it yet though.

The workflow I described has more procedures than necessary, but I wanted to make sure it was foolproof.  eg.  It is potentially possible to remove a cart refill it and replace it within 60s.  However, I can imagine someone new to refilling could panic in the rush to beat the clock and stuff things up.