In their quest to create a portable CNC plotter, Instructables user tuenhidiy combined several PVC pieces with a couple of motors to build the P-CNC Plotter. The small machine — which was designed to resemble a quadruped robot — features an Arduino Uno and a Gbrl control shield at its heart that takes incoming G-code and translates it into motor movements. The X axis consists of a single NEMA-17 stepper motor that actuates a threaded rod to slide the rest of the device along a path. 

There is a central PVC assembly that holds both the threaded and smooth rods for both the X and Y axes while letting the entire thing move. Tuenhidiy was able to repurpose the linear gliding mechanism from a CD player as the Z axis, thus letting the pen or other drawing utensil go up and down with great precision. A set of three A4988 stepper motor driver modules provide the current to both the NEMA 17 motors and CD drive components. 

Images are drawn within the vector-based program Inkscape, and they normally include text, basic shapes, and splines that the toolhead can follow. G-code was exported from Inkscape by using an extension, and this could then be sent to the Gbrl-enabled Arduino. To read more about this project, you can check out tuenhidiy’s write-up here.