Bit of a Warning!

[mikling]

jtoolman

here's a trick. On the exit of the printer to the waste ink tank, put some extra tubing and make at least one 360 degree coil before heading to the waste ink tank. The top of the coil should be higher than the top of the cartridge or CISS tanks.
What is the function of that coil? to prevent the possibility of what happened to you. The coil will have greater capacity than what the printer puts out. As a result, liquid will settle in there and prevent any drying of the ink going back into the purging station...but also not head back into the printer. If you notice, each time the printer runs the pump, it also purges with air afterwards.....to make sure there is an air break. Siphoning won't happen. At the same time, any excess ink that is subsequently pumped out of the printer will just go over the curve but flow over it and not pull the balance along.

Think of an ink P trap just like in your sink plumbing?

I should have showed this as thousand and thousands of external waste systems are improperly designed. It is possible that your purge unit clogged because of drying due to the total exit of ink. The pool of ink is important...it allows the humidity in the ink purge pad to be always saturated and this prevents ink from drying and forming clogs.. The peristaltic pump does not always completely seal all the time when not working. When it is revolving it does make a seal to generate the negative pressure.

 

[jtoolman]

That makes total good sense to me. It's funny that both R1900s purge systems clogged within a week appart. But I was able to bust the clog and ended up with very clean and free flowing purge pads
I will modify the tubing as suggested. I have a bunch of them to do.
I have an orders from PC on the way. The GO is for the Glossing over printer.
Thanks
Joe

 

[mikling]

BTW

I have purchased used Epson printers that had used only OEM ink and you could see some buildup in the purge pads. Take a look at the left side of the printer as well. The pigment builds up on a pad there as well..it turns into a hill. It's a pee station there on the left. See if you can break that down as well. If you have a vacuum pump for your hobbies, you might want to build a liquid trap and that will allow total service of the pads and platen. You would not have to do what you did to service the pads. When I service a printer, I get the pads looking clean after servicing with this setup...just like new.

 

[jtoolman]

It seems that all the RXXXX love to collect ink gunk in that area and I have been aware of that and always do cleanups there about once a month. I do have a couple of vaccum pumps. That would be a good idea. I could buil a bottle collector like we had in the lab used to work in. I could plug it to the wast tubing leading to the currect waste bottles and apply suction while I add cleaning fluid to the purge pads. It would take only a minute to do the job. I used a 60 ml syringe to do the original unclogging. It wasn't too bad of a job but I was amazed as to just how gunky they had gotten.

 

[websnail]

I should have showed this as thousand and thousands of external waste systems are improperly designed. It is possible that your purge unit clogged because of drying due to the total exit of ink. The pool of ink is important...it allows the humidity in the ink purge pad to be always saturated and this prevents ink from drying and forming clogs.. The peristaltic pump does not always completely seal all the time when not working. When it is revolving it does make a seal to generate the negative pressure.

I'm curious as to where this is being aimed but either way I'll bite...

Drying out issues are almost exclusively present when the printer hasn't been used for a considerable time and in particular with pigment ink printers. Same applies with OEM pads in the printers, as with external waste kit with the only primary difference being the aperture open to the pads vs' an external tank. The problem with pads is that they present a "helpful" little structure on which the drying ink can form and present a greater barrier to ink, collecting more pigment/gunk to build up the clog.

Before you know it the pump isn't purging properly but pushing against a sort of trampoline of crud that allows ink to be sucked out of the nozzles and then (on pressure release ie: pump stopping) the ink backflows to sit as an ink puddle in the resting/cleaning pad, soiling the underside and promoting clogging in the nozzles. About the only benefit from pads is that they might take longer to present a problem but with external tanks you get a visual reference that something isn't right (ie: no ink flow) and a simple enough means of checking compared to unmodified (OEM pads only) systems.

The key bits to avoid a clogging problem with an external waste tank are:
1. Tube diameter needs to be comparable to the original. Smaller diameters just make it easy for a clog to form.
2. Smooth bore tube material makes it harder for any crud to cling on, so PVC in some of the after-thought systems is just not ideal at all.
3. Tiny vent hole to keep air circulation to a minimum and keep moisture levels in the tank high

As I said, the key to any drying out issues is going to be long periods of non-use (clogs don't happen overnight) so if a printer has an external waste tank fitted you're going to want to be sure the thing is allowing ink to flow through when you fire it up. Pro-active maintenance of flushing the tubing with some water/cleaning-solution might even be in order.


As for the tube loop, yes, it'll work to avoid a syphon, but given that situations like this are dependant on an unusual setup/situation I'm not convinced it's even necessary. Just my opinion.

 

[mikling]

The pads do not rest against the underside of the printhead though they are called such. The printhead nozzles are placed above the porous block of material we call the pad.

You've got to rethink the purpose of the so called pad which is a porous hard material. If they have the ability to collect pigment and create problems, they would not be used. They are there to increase the surface area so that there is 100% saturation of the moisture level when the head is resting over it. This 100% is easily achieved when there is a lot of surface area for the ink to evaporate. It is hard and does not truly absorb ink so that ink passing through should rinse it off. The printer performs a violent and loud flushing cycle after each cycle that a lot of ink is drawn. This accomplishes a number of things. It attempts to draw the excess ink out the pad thus making sure that it is not pooled and this large draw also aerates the ink inside the tubes thereby "mixing it up" The bubbling action will be enough to stir the ink up and carry it up over the crest even for pigment ink. The sediments are slightly more than the specific gravity of the ink carrier so it actually takes little action to remix the ink.

Also don't forget that there are wiper blades on the purging station to "wipe" the bottoms of the printhead.

Needless to say, if the printer has not been used for a long period, there is the risk of clogging. I said risk, because with a perfectly operating system, you can go weeks without clogging. I have seen an R2400 go for more than six months and one head clean restored it...unusual for an R2400. There is so much misconception about what clogs epsons when a nozzle check is not perfect. My R3000 never clogs even after weeks of non use. No head cleans are necessary on mine. The same could not be said for the 1800 and the 2400s I owned previously. They never clogged BUT they did not produce good nozzle checks after a number of days sometimes. Why? Air infiltration issues related to the older printhead nozzle plate design...the newer designs are vastly improved. Most people call these clogs and Epson was always mum about it because the reason for it is hard to explain and is related to their newer piezo material and PTFE coatings being the solution.

 

[websnail]

The pads do not rest against the underside of the printhead though they are called such. The printhead nozzles are placed above the porous block of material we call the pad.

Actually it looks like you've misunderstood what I was referring to.

What you call "the pad"... I refer to as the "resting" or "cleaning" pad as that's what is does and helps differentiate between that and the waste pad material (effectively the "nappy" or "diaper") in the base or holder unit for absorbing the waste ink.

When you take that into account, if you read back to my earlier reply, the build up in the "waste pad" material does happen quite frequently between the pad and the open end of the waste tube. It's particularly bad with older pigment models with a fair amount of waste ink in them or intermittent use of long periods, and causes a backup.

Needless to say, if the printer has not been used for a long period, there is the risk of clogging. I said risk, because with a perfectly operating system, you can go weeks without clogging. I have seen an R2400 go for more than six months and one head clean restored it...unusual for an R2400. There is so much misconception about what clogs epsons when a nozzle check is not perfect. My R3000 never clogs even after weeks of non use. No head cleans are necessary on mine. The same could not be said for the 1800 and the 2400s I owned previously. They never clogged BUT they did not produce good nozzle checks after a number of days sometimes. Why? Air infiltration issues related to the older printhead nozzle plate design...the newer designs are vastly improved. Most people call these clogs and Epson was always mum about it because the reason for it is hard to explain and is related to their newer piezo material and PTFE coatings.

Agreed...

 

[Smile]

This has happened to me also, now I tend to use print head preservative solution from OCP after using ammonia I do deep cleaning and add the head preservative.