CISS Question and Guidance Help, Please!

[kgvickers]

About a year ago I posted my experience with the CISS I got for my HP C309a here: http://www.nifty-stuff.com/forum/viewtopic.php?id=4715

For the most part I've had good luck with this but since my son moved out and went to college the amount of regular printing has dropped. Consequently, air is apparently leaking, or, more likely, being drawn into the bottom of the carts by whatever slight negative pressure is there from the CISS and I see air in the CISS feed tubes where they plug into the carts. Normally a head cleaning will fix this but I think I'm now at the point that I'm going to have to purge the air from the carts. I'm not looking forward to this messy process.

So, here's the question - shouldn't I slightly raise the CISS tanks to relieve some of this "suction"? The instructions were adamant about placing the tanks at the same level as the printer but obviously long term this causes some air to be drawn into the carts. I realize that if I raise the tanks too far there will be an "over pressure" condition that will likely cause serious ink leaks.

It appears to me that the "weep" hole in the tanks is presently below the height of the print head and certainly the bottom of the tanks where the hose exits is even further below. I suspect that the weep hole should be at or only slightly below the height of the print head - correct? My guess is that it is currently too far below. Or another possibility is that there is not a good seal on these after-market cartridges that came with the CISS.

No doubt the foam material in the OEM cartridge gives some level of "negative" pressure (resistance to ink flow) so that must figure in also.

I know some of you are experts in the physics of the CISS Mariotte Siphon so I'd love to hear from you.

Thank you,

Keith

 

[The Hat]

kgvickers
The way to solve your problem is to remove the offending cartridge from the print head and place it on a cloth beside the print head.
Next remove the air inlet valve from the colour with the problem and using a syringe (needle removed) place it on the hole where the valve usually sits.
Now very slowly press the plunger down and you will see that the air is now going into the cartridge which you should have upside down.
Do this till the tubing is clear of air but be careful not to let too much ink come out of the cartridge and spill all over the place.
If more than one colour has the same problem repeat the process with each of them.
Please REMEMBER to press S l o w l y...

You don't want to get ink on your face, hands, walls etc etc.....

 

[qwertydude]

I find that an easy way to avoid a lot of ink spilling is simply hold the cartridge below the tanks and pull the priming plug on the cartridge. The ink will simply siphon down into the cartridge. Tilt the cartridge back to get as much air out of the first chamber as it fills and then when the second chamber of the cartridge is almost full you can raise the cart and immediately plug it.

 

[kgvickers]

Thanks for the suggestions.

After reading a few other threads on the CISS subject I decided to slightly raise the tanks. Right now they are sitting on two "Post-It Notes" pads . . . I think that's somewhere around an inch of lift. The print head is still above the weep hole. So far this seems to be working and I have not yet noticed a leak issue.

The vendor for my CISS is now including purge hardware (storage clips with hoses and syringes) in the kit so I'm guessing I'm not the only one with this problem. Fortunately they are selling the purge kit separately so I'll probably go ahead and get that just to make things easier.

Keith