True Bottom-Fill Possibility for Canon Carts?

[SilverWings]

Howdy everyone. I should declare up front I'm new to this forum and at present I'm new to the refilling idea, though I did have a CISS for an Epson for some time (with mixed results). Well the Epson died some months ago and I finally got around to doing some photo-printer shopping and found this forum. I just purchased a Pixma MG6120 so it will probably be some time before my original carts NEED a refill. But I've been reading up on many of the postings here and while there's a lot of opinions, it seems the two valid refill methods are "top fill" and "german". Messing around with the sponge side, like vacuum refilling or outlet saturation, doesn't seem to be a good idea. (Both top fill and german methods inject directly into the open reservoir) Canon seems to have gone to some lengths to regulate the pressure balance in the cartridge and any alterations to the pressure balance are best avoided. With that in mind, I see some minor flaws in both top fill and german methods:
TOP FILL
Obviously top fill depends heavily on the user reestablishing a seal on the fill hole. If the seal is not true, air will leak through and the entire cartridge will leak all over the place. The other issue I see is that during filling, ink simultaneously filling both the reservoir and the sponge, which could over-saturate the sponge. (more on that in a minute)
GERMAN
The german method obviously gets around the vital seal issue of the top fill which is probably it's best feature. However with the insertion hole remaining open, it does alter the airflow / humidity path that Canon set up so carefully. Inserting the needle through the foam pad has the potential to damage it if not done right. Plus with the new 225/226 carts, you have no way to know just when it's full and there's no failsafe to prevent you from overfilling it potentially over saturating the pad or possibly clogging the serpentine air pathway.
Back to sponge saturation - I took note in Phamacist's very nice photos of the german method that after filling, the ink is allowed to naturally absorb into the pad at it's own rate (the bubbles photo). Top fill cannot do this as you can't flip the cartridge over while filling due to that pesky gravity thing.
BOTTOM FILL IDEA
Ok here's my idea. Basically, you take top fill, and flip it over, drill into the bottom wall of the reservoir, and fill just like you do in top fill, then reseal. I suggest this for two reasons. 1) after the chamber is full, apply the seal, and flip over. If you've sealed it right, the cartridge is completely unchanged from a pressure balance standpoint. The pad absorbs what it needs naturally like when it was new, just like German method, but without plunging a needle through and leaving a hole open. 2) It is easier to seal the bottom fully than the top. This might seem counter intuitive, but consider - the top fill seals against air, bottom fill would seal against a liquid, which for argument sake is similar to water. Water is 50x more viscous than air (I looked it up) and requires a much larger opening to leak through. Also, if there should be a leak, you're more likely to know it right away - a small air leak would work over time, out of site, while a bottom-ink leak would start right away, before you put it in the printer. You'd probably have to use tape or hot glue to seal, since it would need to be almost flush, which is the only a down side I can think of compared to top fill. (Though I have found aluminium foil tape to be fantastic at similar applications)

I'm interested in what you experienced types think. The only problem I can't figure out is how to get around these opaque carts (short of doing a chip-change onto the 221's) but if you did overfill, it wouldn't over pressure the cartridge like the german method would - it'd just start leaking out the fill hole. But I haven't seen anyone with a good solution to this problem yet, either.

 

[panos]

No matter which method I would choose, I find transparent cartridges a necessity. Even though I am loyal to original cartridges for their superior design & manufacturing, I would first try to find the highest quality transparent aftermarket cartridges.

 

[ThrillaMozilla]

However with the insertion hole remaining open, it does alter the airflow / humidity path that Canon set up so carefully.

Some people advocate that it be covered with aluminum tape. And personally, I don't think it has been demonstrated that it creates any problem with air pressure, i.e. flow. I'd be more concerned about drying. But it's a minor point, and in any case, there are lots of people on this forum who have refilled tens or hundreds of times with this method. So I wouldn't worry much about it, SilverWings.

Plus with the new 225/226 carts, you have no way to know just when it's full

Sure there is. Tip the cartridge so the needle tip is below the top of the ink chamber. Now draw back a little on the syringe. If you get air, the needle tip is above the liquid level; if you get ink, it's below the liquid level. You should be able to fill it to any desired level (preferably full) even if the cartridge is opaque. For that matter, you could also judge the liquid level by shaking the cartridge and listening.

I took note in Phamacist's very nice photos of the german method that after filling, the ink is allowed to naturally absorb into the pad at it's own rate (the bubbles photo). Top fill cannot do this as you can't flip the cartridge over while filling due to that pesky gravity thing.

Well, yes you can, I think, but you have to understand it. By tipping the reservoir you should be able to control the head while you're filling. I don't want to get into the details. Or check out Mikling's procedure for a start.

BOTTOM FILL IDEA
Ok here's my idea. Basically, you take top fill, and flip it over, drill into the bottom wall of the reservoir, and fill just like you do in top fill, then reseal.

No drilling. Check out Freedom Filling. http://www.nifty-stuff.com/forum/viewtopic.php?id=6750

 

[SilverWings]

Some people advocate that it be covered with aluminum tape. And personally, I don't think it has been demonstrated that it creates any problem with air pressure, i.e. flow. I'd be more concerned about drying. But it's a minor point, and in any case, there are lots of people on this forum who have refilled tens or hundreds of times with this method. So I wouldn't worry much about it, SilverWings.

I wouldn't say it's necessarily a problem, but clearly it's not ideal. You can't separate ink drying from air flow, as without airflow, there can be no drying effect. It makes sense that the german method would 'breathe' more than an unaltered cartridge - the hole is many times larger than the serpentine path - and it's the extra air movement that carries away the moisture in the form of water vapor.

Sure there is. Tip the cartridge so the needle tip is below the top of the ink chamber. Now draw back a little on the syringe. If you get air, the needle tip is above the liquid level; if you get ink, it's below the liquid level. You should be able to fill it to any desired level (preferably full) even if the cartridge is opaque. For that matter, you could also judge the liquid level by shaking the cartridge and listening.

You may be right, but I think I'll avoid shaking a container full of ink after it's been opened. I like my clothes / carpet the color that they currently are.

Well, yes you can, I think, but you have to understand it. By tipping the reservoir you should be able to control the head while you're filling. I don't want to get into the details. Or check out Mikling's procedure for a start.

I see your point. Held at the right angle that might work.

No drilling. Check out Freedom Filling. http://www.nifty-stuff.com/forum/viewtopic.php?id=6750

I did (I read almost all the posts on this topic) and here's where you lose me. One - I've already established in my approach that forcing ink through the pad side is not a good idea. It's just an observation of many opinions posted, disagree if you like, but it's the premise I'm working off of. "Freedom" filling forces all the ink through the foam pads which will become thoroughly saturated with ink before it even begins filling the reservoir. From looking at the operation of the cartridge, the top foam pad is not meant to be forcibly saturated and should only be exposed to natural capillary action. (There no other 'natural' path to it from the ink well) Second - by pressurizing (even a little) the normal outlet hole, the volume displaced can only escape through the serpentine path. Unless you fill it up incredibly slowly, you're going to have a serious differential pressure effect and high velocity through the serpentine which it was not designed to handle. Third - Since the 225/226's are fully opaque, once you do fill up the cartridge, the ink will have nowhere to go but INTO the serpentine path to try to escape the pressure inside the cartridge. Once the path is clogged with fluid (any amount of fluid would do) the cartridge will fail. Obviously this is less of an issue on the older cartridges.

I'm not saying it won't or doesn't work. You may have great success with it, I really don't know. But looking at it strictly from an engineering perspective, the freedom fill method doesn't appear to be a particularly good idea.

 

[ThrillaMozilla]

without airflow, there can be no drying effect.

Not true. There's also diffusion. Have you constructed a detailed physical model of advection and diffusion inside the cartridge? Neither have I.

It makes sense that the german method would 'breathe' more than an unaltered cartridge - the hole is many times larger than the serpentine path....

No, the amount of air flow doesn't change. You remove 10 mL of ink, you replace it with 10 mL of air. You contract 10 mL of internal air by 10% due to atmospheric pressure change, and you suck in 1 mL of air from the atmosphere. It's the same amount of air, regardless whether it goes through the front door or the back door. The larger hole does allow more diffusion, however; and the long, thin dimensions of the serpentine path are designed to limit diffusion.

...forcing ink through the pad side is not a good idea. ..."Freedom" filling forces all the ink through the foam pads which will become thoroughly saturated with ink before it even begins filling the reservoir. From looking at the operation of the cartridge, the top foam pad is not meant to be forcibly saturated and should only be exposed to natural capillary action. ...Unless you fill it up incredibly slowly, you're going to have a serious differential pressure effect and high velocity through the serpentine which it was not designed to handle. ...Third - Since the 225/226's are fully opaque, once you do fill up the cartridge, the ink will have nowhere to go but INTO the serpentine path to try to escape the pressure inside the cartridge. Once the path is clogged with fluid (any amount of fluid would do) the cartridge will fail.

Nah. All pointless worries, my friend, as you quickly discover by working with it a little. But as you don't seem to believe much of what we've written, and I dare say you've also missed a point or two, it would probably be a good idea just to use another method. Fortunately, you have two good choices besides Freedom Filling.

By the way, did you not say that only yesterday you were new to the refilling idea? And did I not set you straight on ink levels in opaque cartridges?

 

[ThrillaMozilla]

P.S. The idea of the freedom fill is that you fill under vacuum, so you don't need to worry about ink escaping under pressure, and you don't fill the vent.

You will need a good syringe, though -- one with a plunger that works easily so it will return under vacuum. Small ones are tedious to use, and large, good ones may be little hard to find them in small quantities. Mine are all way too stiff for this.

Good idea about the bottom fill in the ink chamber, though. But if you want to do a top fill, Mikling sells some silicone plugs at Precision Colors that a lot of people recommend highly. You might save yourself some trouble.

 

[barfl2]

Silverwings I understand your concerns about the Freedom vacuum method. I believe This method is widely used by commercial refillers. I am one of the contributors to this thread and built my own device. In actual use you position the cart so that the ink flows through the normal opening at the bottom which flows steadily through the lower sponge, it does NOT RUSH IN AT A TREMENDOUS RATE.

Most users will by now will have their preferred method and will stick to it. I will use all 3 I quite like the Freedom method having issues with both the others, but there is a learning curve which you have to accumulate by trying, reading up other members travails and learning by their mistakes, and taking note of what our many Experts advise.

Theory is is fine practical results are something else.

barfl2