explain me the mystery with CLI-551..

[QQ]

hi,

from what i see here: http://www.canon-europe.com/ink/Yield/multifunctionals/PIXMA_MG6350.aspx

the XL cartridges list more than double the yield.

But from what I've found on google, normal cartridges are 7ml, and XLs are just 11ml.

So how can the yield be double..?

thanks!

 

[The Hat]

hi,

from what i see here: http://www.canon-europe.com/ink/Yield/multifunctionals/PIXMA_MG6350.aspx

the XL cartridges list more than double the yield.

But from what I've found on google, normal cartridges are 7ml, and XLs are just 11ml.

So how can the yield be double..?

thanks!

All of the figures that are given are only guess-estimate; it all depends on what youre actually printing.

Overall the XL cartridges are much better value than the start-up cartridges,
either ways it still not cheap whichever ones you choose to use..

 

[PeterBJ]

You are right, something doesn't add up. The 7 and 11 ml capacities is also what I have read from many sources. so the page yield does not make sense. But if 2-3 ml of ink is lost from the cartridges, proportions of remaining ink in the standard and XL cartridges fit the proportions between page yields much better. But do these printers really waste that much ink in priming when changing a cartridge, and subsequent print head cleanings? Or could it be a miscalculation/misinformation?

But the capacities could be not the useful capacities but amounts of ink filled into the cartridges at production. More than 1ml will be left in the cartridges when they are declared empty by the printer. If you have a small digital scale you could weigh the cartridges before insertion in the printer and after they are empty to find their true useful capacities.

I am sure many forum members would be interested in these figures, if you are able to provide them.

 

[QQ]

hm, that's a good point there, PeterBJ.

Otherwise, XLs wouldnt make any sense - they are approx 55% more expensive, and that much bigger ml wise.

 

[PeterBJ]

I have weighed a set of new OEM and some "virgin empty" PGI-520/CLI-521 cartridges, and here are my results:

As you see, there is a difference between nominal capacity and useful capacity of more than one ml. The printer also uses ink to clean the print head at cartridge change, at power up, and at some intervals determined by firmware counters and timers. The ink used in cleaning and maintenance is dumped in the ink absorbers in the bottom of the printer.

So to me it looks like a significant part of the ink in the cartridges is left in the cartridges and another significant part of the ink is dumped inside the printer. I don't know if Canon is worse than other printers, all printers need to use ink to keep the print head in good working order, and no cartridges can be completely emptied as the printer needs a steady supply of ink to cool the print head. Attempting to empty the cartridges 100% would ruin the print head.

I think this is the explanation.

 

[mikling]

It is a combination of priming and this sometimes lost aspect. The cartridge may hold the 7 ml but how much of that is actually held back by the fibrous sponge before it is declared empty. Attempting to suck out the last bits is impossible on a sponge based cartridge. So suppose you assume say only 4ml of the 7 inside the cartridges is useable, then you are left with 3ml "stuck" on the sponge. If this were true, then the XL would in fact double the useable capacity.

From another side, the 4ml matches the competition the Epson T273 cartridge which appears to be 4 ml from empty to empty. In Epson's case, they are able to squeeze more ink out so the cartridge itself is loaded with less initially.

From a refill standpoint, the stuck 3ml is somewhat inconsequential.

No matter what, the capacities considered "normal" are way down. What was once considered standard is now XL.

Fast food as well as packaged foods comes from the opposite end. The serving portions of what is the new normal now was once considered extra large and possibly why many persons follow the same trend. I'm there too, I gotta work on it.

My detail measurements to 0.1 gram indicate that empty conditions can vary by as much as 20% on Epsons on the T273s. That is the reason why reserves must be left when running on chip ink levels and some other form of detection must be included.
In this situation Epson has Canon beat. Canon MUST estimate the empty condition in the sponge... a process that is inaccurate. Epson can now do this with precise impunity with the optical sensor in their new cartridges. So when Epson on their T273 cartridges say empty, they are in fact truly empty with a tiny amt left to keep the head in good condition. The proportion of sponge to ink in reserve looks to have increased in the new Canon cartridges so I imagine, they must also account for that as well by allowing more reserve. If Canon goes generous on useful amounts, they tip the scale to potential warranty claims as a result. It is a balance.