For lack of a better name, here it is, the weird kind of printer!
As I explained, it's a printer but instead of an inkjet head, there is a needle driven by a solenoid. I still have to figure out what to use that for but the results keep getting better so I decided to shoot this little video. Some friends of mine have started to test it for screen printing and it works quite well! Many other uses to come (braille printing, embossing, and many more..).
On the technical side, I use two Nema 17 stepper motor driven by an adafruit motor shield and a solenoid. On how to drive a solenoid from an arduino see here. A processing program thresholds the image and sends coordinate to the arduino sketch uploaded on the arduino (call-and-response protocol to avoid any data loss). All in all this is a pretty simple setup! The structure is laser-cutted and most of my parts come from the CNC section of the adafruit website, except for the urethane tube used to move the paper, which I got from ebay. My goal was to buid this machine for less than 200$ and I am pretty close to it!
If you have any questions or have any specific use in mind, feel free to contact me!