This week I have another "Parts Project" along the lines of the fax and phone system that Otto Jr. and I took apart HERE. As I mentioned in that post people that know me offer to give me a lot of the old electronics 'junk' that they don't want anymore and I really can't bring myself to say "No thanks, I don't want (need) it...". So what I usually do with this kind of stuff is take it apart and keep all the interesting bits that I think I might use someday, and throw away all the other parts (or recycle them). I enjoy doing this because not only do I get to increase my stockpile of motors, screws, springs and other neat stuff but I also get to see how various things are put together. I consider this a career related learning experience because as I have mentioned I design stuff for a living and it's fun and educational for me to see how other designers and engineers have solved packaging and construction projects.
This time I was given a used EPSON Stylus NX100 ink jet / scanner / printer. Ink jet printers are always full of little motors, springs, cam mechanisms, and of course ink. This is probably the third or maybe fourth printer that I have taken apart and they are all very similar inside even though they are designed and built by different companies. This one was especially neat because it had DC brush motors instead of the more common stepper motors in it for the paper feed. The scan head was driven by a small stepper and steppers are neat but as I have mentioned before they are a bit trickier to use in other projects as the electronics needed to drive them are a bit more complicated. Anyway I got 2 DC motors, one stepper and a bunch of gears and springs that I might use someday. As always the most useful part is the power supply and this one had a very simple one with 2 voltage output. Lots of fun and maybe I'll use it for something later.
Above is a picture of more or less what was left after I removed the things I wanted. In the top of the picture you can see the power supply with all the little cooling holes in the metal shield, the DC motors and a couple of the gears. I'm going to recycle the base in the above picture but I wanted to include it in the picture to highlight a couple of interesting things. As I mentioned all the printers that I have taken apart tend to be very similar in construction and operation. One of the more interesting commonalities of these devices is how the excess ink is dealt with.
First off this is a view looking down on the top of the device as it would sit on the table. The top of the picture is the back of the unit. On the right side by the Yellow arrow is where the printer head sits when it's not printing. The print head moves from the right to the left as it prints depositing ink onto the paper as it goes. That small black rectangular shape that the Yellow arrow is pointing to is what the actual print head sits on when it's not moving. That thing is a plastic encased metal 'grate' that has some sponge foam on it. The excess ink from the print head gets sucked into the grate and through the gray tube by the little gear driven pump that you can see by the Green arrow. The ink then passes through more of the gray tube and spills out the plastic funnel highlighted by the Red arrow. That little funnel is laying on it's side in the picture but when it's in it's installed location it is sitting on top of some felt like material that you can see just between the Green and Red arrows in the picture - the dark black square area in the picture.
Around that dark black square area you can see the white felt material and it has some black speckles and spots. Those speckles and spots are the excess ink that was dumped out of the gray tube and funnel into the felt. All of this felt and foam is in a recess at the bottom of the printer and the more you use the printer the more ink that gets deposited into and soaked up by the felt. Every printer that I have disassembled is similar in this respect. All the unused ink gets 'dumped' into felt at the bottom of the printer. The more you use the printer the more saturated the felt becomes. I don't know how well used this particular printer was but there isn't much ink sloshing around in there. I have taken some printers apart that had the felt soaked in ink with even more ink puddles in the bottom and all over the inside of the printer.
Why am I writing about this? I'm writing about it for no reason other than I think it's interesting and something you might want to consider if you ever move a well used ink jet printer. If there is enough ink in there and you were to turn it on it's side or upside down, the ink will all come spilling out or at least it will get all over the inside of the printer and destroy it. Pretty cool!!! I guess there isn't a better way of dealing with excess ink and because these printers are at this point basically disposable (and free if you buy a computer in many cases) they figure that you will get rid of the printer before it ever fills up with ink. If you are the kind of person that keeps things as long as they can and takes care of them I suppose that someday your printer will just fill up with ink and it will come spilling out the holes and seams someday. I just find this odd... I have not read the users manual on any of these printers and maybe they mention this someplace in the instructions.
That's about it for today. Even if this post wasn't all that useful or interesting it is what I did today and it gave me something to write about. Happy printing!