This project was inspired by a commercial product called AxiDraw that I saw a video of recently from Evil Mad Scientist Laboratories.
It was a combination of reasons that made me consider to do it myself, cost, availability and customs playing a role in the equation (that, and having a 3D printer at home).
This is just a drawing machine quite similar a to a pen plotter but that can adapt to any size of document and any type of paper.
It can use regular felt-tip pens, ball pens or fountain pens as pen orientation is variable. It is a new version of an XY plotter using a single belt and two stepper motors in a configuration called h-bot.
Bill of materials
(*) Stepper motors should be 40mm or shorter, unless you chose the taller parts that I later created for some users willing to use 48mm tall steppers (like many use for 3D printers).