Canon CIS's something to watch out for

[websnail]

In truth, I'm still finding problems with some kits and it's becoming glaringly obvious that what I'm dealing with is a variety of minor and major variables that affect the final outcome. Right now I'm wondering just how much differential there is between printheads and some of the tubing I'm using.. Certainly it seems that home made kits are trial to different issues affecting different printers and that in turn points to problems with my parts, glues, etc.. So take my comments as a gifted amateur stumbling along a dark corridor from time to time.

As to the HK kit.. that's spongeless so it won't have the same issue as described in the initial post, however it is likely to have other problems such as potential free flows, although that is supposedly countered by the balanced pressure system in the reservoirs.

 

[mikling]

Be aware that the balanced pressure system is based on a principle that fundamentally only works when the ink is flowing at a constant rate. The inkjet printer does not use ink at a constant rate....quite the opposite actually. Any system that does eventually work only does so because the tolerance of the system is wide enough that it just "happens" to work and thus it is a bit of luck of the draw.
Consider this as well. Take a piece of tubing. Calculate the volume of the tuning when it is straight. Now bend the tubing into a curve and calculate the ink in the tubing now. It is different. Now what happens to this difference as the head moves back and forth and the feed lines flex? Well, since fluid is highly incompressible something happens but yet it still works. IMO Balanced flow is more marketing than reality.

 

[canonfodder]

Be aware that the balanced pressure system is based on a principle that fundamentally only works when the ink is flowing at a constant rate.

Mikling, I would like to know exactly what the "balanced pressure system" does so that I might understand just how the design works. This thing has my curiosity at full throttle.

Could you possibly describe how it is put together and just what goes on in such a system?

It is obvious that when they use a cartridge that has no sponge and yet the cartridge does have a quantity of ink in it, something has to prevent the ink from just flowing right on down through the head. I have assumed there is some negative pressure in the cartridge part of the CIS system. Please tell us all of the details that you know.

Thanks,
canonfodder

 

[mikling]

Do a Google on the Mariotte bottle. A number of links will appear that when you look inside various CIS they all use some variant but the fundamentals are key.

 

[canonfodder]

Mikling,

Thanks for the good clue about the links to "Mariotte bottle". I found a particular link which clearly elaborated on the abilities of the the Mariotte bottle. The link is http://lawr.ucdavis.edu/classes/ssc100/mariotte_bottle1.pdf .

You said before, "Be aware that the balanced pressure system is based on a principle that fundamentally only works when the ink is flowing at a constant rate", and many applications of the bottle do exploit that particular ability, but if you look at the information at this ucdavis site, you will see that the bottle has the ability to produce a constant PRESSURE, either positive or zero or negative, dependent on the height of the water outlet relative to the height of the low end of the air inlet tube. Flow is not necessary for the pressure to exist, but the available constant pressure CAN be used to produce a constant flow when a positive pressure is enabled and a known restriction of the outlet is present.

Perhaps in some CIS which exploits the principle of the Mariotte bottle, the arrangement is set up to produce a zero pressure at the height of the print head ink inlet, allowing the pumping action of the print head to pull in ink as required.

I think that the CIS from Hong Kong is one step more involved, because some sort of closed system has been designed. Their information reports "no air filter" and "internal air balance system", implying no inlet for outside or atmospheric air.

When I have the CIS in hand, I will try to understand the "plumbing" and report on how I perceive it to function.

 

[websnail]

Had to go away and think about the mariotte bottle style reservoirs and then remembered that one of the reasons for this type of bottle was that it ensured that you didn't enter variable of ink pressure within a reservoir. Normally I use a dipped tube style of reservoir and as the ink level in the bottle drops it obviously lowers any residual pressure from the ink.

Personally I doubt it adds too much of a problem in CIS kits where there's a sponge damper or something similar in play but when you have spongeless carts with low tolerances (which sort of harks back to your point Mikling) then you want to remove any pressure variables or else you may starve, or more likely, drown the printhead. I don't use these style of reservoir because quite frankly their a bit of a pain to refill but I suppose there's more than just marketing spiel behind them at the end of the day.

 

[photophile]

Installed the CIS for my Canon i9900 from the Hong Kong seller on eBay. Printed about 30 photos so far. In general, I am pretty happy about it.

I do have a few issues though:

1. The supplied silicon pads are about 1/8' thinner than the original black Canon rubber pads. This should be the right design according to Websnail's finding. However, several ink cartridges do not fit well with the silicon pads in the print head housing. It may be due to poor QC of the cartridges as the remaining cartridges seem to fit OK. I ended up putting back the Canon pads, which allow for much better fit.

2. The cartridges are poorly made, I even saw cracks between the two pieces that made of the cartridge, in which I had to push it back manually to close the gap . Not all cartridges fit nicely in the print head housing. The spongeless ink tank has a sponge plug at the bottom where it meets the print head.

3. I had to do three deep cleanings due to clogged magenta and photo magenta print heads. I was advised by the seller to raise the ink tanks by 1" until the continuous flow has been established between the ink tanks and cartridges. The seller also indicated that the room temperature could also affect the continuous flow.

4. After about 30 photos, which includes two 13x19 and six 8.5x11, I could see visibly decrease in ink volume of several tanks. But there is no visible change in ink valume of other tanks. I have confirmed that the cartridges inside the print head housing are full, an indication that the continuous flow has been established? The Canon maintenance software showed megenta, yellow and cyan almost gone. Used a lot of ink in deep cleanings.

5. Need to buy a bulk supply of ink. Any suggestion in terms of whcih brand to buy? I know I should not mix the inks from different suppliers, but it is hard to imagine that I have to empty the remaining ink tanks and clean it even though one ink tank runs out. I may just top it off with the new ink whichever intank is low without replacing the rest.

 

[Xalky]

Here's a good place to get Image Specialists ink. http://www.precisioncolors.com

He sells on ebay or you can go direct to his site send him an e-mail and pay thru paypal.

Good Guy too. He's been very helpful to me.

 

[photophile]

Thanks, Xalky. Just placed an order for a set of 4 OZ package. Great price.

 

[ocular]

Great discussion going here. With these minds and experience the ultimate flawless CISS (set and forget) can be developed. I have just trialed a CISS on an IP3000. Nice to be able to fool around on a machine that has minimal number of cartridges and no chips. This came from http://www.selectiveimage.com.au which I found originally on ebay. I can compare this system to my currently installed Sinopis systems on MP730 X 2. Both the sinopis and selective image CISS have sponged cartridges, the sinopis has the tubes going in over the sponge compartment and the Selective image CISS tubes enter the cartridge over the non sponge compartment(not sure if there is difference of fluid properties).

The Sinopis systems have been in place in an office setup for 2 yrs now and the colour cartridges are not supplying ink adequately, this is not a real problem as black has been reliable. I think the sponge resistance is increasing with time and the cartridges may need replacing- ( interestingly the black cartridge was the only one to be fitted with an extra crude silicon washer under the cartridge).

Both brands of systems tubing have elbows that that push into silicon sleeves and can be easily removed. Both brands have non mariotte type bottle systems. Interestingly I tried a spongeless CISS that never worked. The spongeless units from www.rihac.com.au I haven't tried but rihac seem to standby their systems. These spongeless systems both have Mariotte type ink bottles - suggesting the fluid head pressure needs to be more constant for spongeless CISS.

The Selective Image ( the unit I have just installed in an IP3000) system's instructions are much more particular about fitting silicon washers. They advise to clean the canon rubber seals carefully and the accurately machined add on silicone washers are layed against supplied adhesive pads , one side then the other. Tweezers are supplied to facilitate this. The instructions say this is to remove any dirt particles from the silicon washers, but it is likely to add a more adhesive seal between the exit port and the existing Canon rubber? This sytem has been working flawless on the IP3000 ( only 1 week old).

Websnail has pointed out that these washers can be too thick and push the cartridge too far away. Maybe carefully cleaning the canon rubber and the print head pickup and the rim of the cartridge and both sides of a 0.5mm silicon washer and applying a thin smear of silastic compound to each side of the washer and then installing the cartridges and allowing the compound to dry before use is the way to go. After all with a CISS the theory is that you should only have to place the cartridges in the print head once and then if everything works then they don't have to be removed.

There is no doubt that CISS require a better seal between the cartridge exit port and the print head than is provided by the OEM setup. A reliable sealing technique needs to be described, one that won't push the cartridge away , but will still seal, accommodating some of the lesser quality after market cartridges that can vary in size ( even within the same brands). Hopefully these comments will stimulate the tinkerers to go off and start experimenting!