Part of my bioprinter project is comparing the printing I can do using my craft robo contraption with the printing done using a modified inkjet printer. Several papers are published on using modified inkjet printers, so it’s a good standard. Following the instructions published in JoVE (Journal of Visualized Experiments) I went out to buy the oldest, shittiest printer I could, because they are less likely to clog with the biological reagents and easier to trick and modify into doing what you want. I got an Epson Stylus S22 for 29euros. I quickly removed the casing.
The first thing I wanted to do was disengage the paper feed mechanism. I found the power lines of the paper feed motor (below the shiny metal piece, black and grey wires, not the blue grey grey wires) and unplugged it from the motherboard.
Unfortunately now nothing moved, including the ink cartridge, though the printer did turn on. The power light just blinked sadly. I concluded that this printer was too smart and new — it had an encoder on one of the paper feed gears, so when the motherboard tried to feed paper but didn’t, it knew what was going on and refused to move on and perform any other tasks. The encoder is the plastic disk with a grey band around the outside. The grey band is actually a series of very fine black lines that I assume are optically read to provide feedback on location and speed.
The paper feed mechanism could not be disengaged without tricking the encoder. The other option I considered was disengaging the gear that had the encoder from the rod it was on, but that seemed tricky given its location in the printer (hard to reach, I was likely to break something important).
It seemed like the printer was probably too fancy, but I decided to have a go at emptying and refilling the ink cartridge, another necessary task. My first go at resulted in me basically tearing the cartridge apart because it was so strange looking and I wanted to unwrap it as best I could. It ended in an inky mess. Note: I took out these cartridges after the printer said that they were empty. This is an indication of what “empty” means to Epson:
My second go was much better. Good thing the printer came with four cartridges.
So what I found was a lot depressing things. It’s pretty hard to refill these things. There’s not clear “top” and most of it is packaged in plastic, so once you puncture it it’s hard to reclose it. There are also several different ink chambers and it’s unclear exactly how they are all fed into the ejection chamber — I see the physical connections, but it seems like it would have to be pumped. There is also a chip (on the side, not pictured here) that is written as “empty” by the printer, so even if you refill the cartridge mechanically the printer will still recognize it as empty. Finally, Epson is purposely trying to rip me off by clearly leaving about half of the space of the cartridge empty, when it could be filled with ink.
Some quick internet research tells me that they do all of these things on purpose – make it basically impossible to refill, and some cartridges, probably mine included, include a second hidden chip that reads as empty. Epson has also managed to ban copy-cat cartridge imports into the states, such that they can continue to charge ridiculous amounts.
Moral of the story: Don’t do this on an Epson printer! Next I’m going to look at HP Deskjets. The JoVE article used an HP Deskjet 500, but it’s almost 3 times as expense to buy an old printer than the newer 3000 version. However, the cartridges are different, so I may run into similar problems.