Thank you for your support guys. You don't even know me.
Last night my buddy Steve and I (no he is not my invisible friend), removed our clogged Epson 7900 print head. It was very exciting. Up until that point the only obvious problems we found were the torn, gooey, worn out and cockeyed wiper blade. Yes the capping station looked a little messy but I never got the feeling the capping station was the cause of our clogs. More it was the result of them. The Damper Assembly we decided to change because the manual recommended it - not because it looked like it needed it. Neither of us expected new dampers to make any measurable difference. But the head we both knew would reveal everything. The head would make our journey, or break it. We had to remove it. We had to inspect it. After all this build-up, how could we not..?
As you can see from the image a few posts up, it looked pretty nasty. Obvious, definite connection between the condition of the face of our head and the condition of our wiper blade. As sloppy as the wiper blade was, is as sloppy as our head was.
I had all these visions of taking microscopic macro shots of the face of our head, blowing them and searching for visible clogs. I doubted we'd be able to see them, but I was ready to try every trick in the book in order to do so. Much to my surprise though all we needed to do in order to see them was turn the head over - there they were. PK clog was clear as day. YW clog cluster right out there in the open. These pics were taken of the head exactly as it sat ready to print - no external wiping, cleaning - it wasn't touched.
If you want to look closer, click
HEREIn my opinion the cleanings actually added to our problems. With the wiper blade compromised the cleanings just ended up spreading more crap over the head. When we got to it our wiper blade was not just wet with ink, it was coated with
layers of ink. The surface area of the rubber wiper which touches the head was dry, but just past those areas the ink began to build up - first just wet, then wet but thicker, then kind of gummy, then simply crusty. I am pretty confident this is what CAUSED our clogs, not what failed to clear them. Think about it - microscopic holes just dying to be clogged, critically sealed over a capping station while not in use, routinely flushed with expensive ink to help keep them clear of any ink build-up - then smothered with a butter knife covered with chunky peanut butter.
No brainer, this is a critical, weak link in our Epson 7900 routine maintenance chain.
Cleaning an Epson 7900 print head:For a week now Steve and I have lost sleep plotting a safe course through the hazards of manually cleaning a 7900 print head. All you ever read about is how delicate these things are. But what you don't read about is why they are delicate, or how they actually work. Pardon me while I trip over my tongue trying to explain something I do not understand. These heads are far more than a series of nozzles lined up in rows. They're actually not "nozzles" at all. At least not like we know nozzles in the garden hose world. Instead the 7900 print head nozzle technology is built around a fascinating phenomenon called "Piezoelectricity". This is pretty high-tech tiny world type stuff but in monkey language the concept is rather simple - tiny crystals which change their shape when electrically charged. Your Epson charges the line leading to "nozzle" 18b, it flexes and ink squirts out of your print head. Do that fourteen million times in a row over a slice of Gloss Baryta and you and I end up staring into 80 square inches of the final resting place of more technology than we will ever fully understand or appreciate.
So yea, now that you think about it, an Epson 7900 print head is not something you want clean with a shovel. The solution we came up with is something I think is working remarkably well. We suspended the head, face down, JUST over the surface of a mixture of cleaning solution mixed with distilled water. Due to the mysterious characteristics of yet another physical phenomenon, called "Surface Tension", we actually did NOT have to submerge the face of the head into the solution. Instead hovering the face ever so close to the surface of the solution caused the area of the solution just below the head face, to rise up from itself and cling to the head. It was kind of magical actually, but even more amazing is what happened next. The solution instantly began to suck ink from the head. It was oddly beautiful actually. I wish I filmed it. Instead I took a few photos. We left the head hovering there last night. After today's drama I came home tonight to completely black solution under the head. I lifted the head to inspect it. It looks immaculate - virgin.
Been one hellofaday I'm off to bed. More tomorow.
