The Pen Plotter is a simple self made CNC machine that uses an Arduino Uno to power everything. This was made to learn more about how CNC machines function and how these machines interpret gcode instructions using an Expo marker to make drawings on a table. Connected to the Arduino was 3 NEMA 17 stepper motors to control the X and Y movements, a servo motor to move the Expo marker up and down during the drawing process, and 2 limit switches for the X and Y directions. connected to a CNC shield that attached to the motor to help with cable management and to have 2 NEMA 17 motors moving in the same Y direction.

The project started off with just learning how to send simple commands to the plotter using the Arduino program. Using Arduino along with Universal Gcode Sender (UGS), simple commands were sent to the machine to make sure all the motors were working, UGS was recognizing that limit switches were hit, and that the machine could home itself. The next step was making simple designs in Fusion 360 and using a post processor to translate the design into gcode commands. The last step was learning how to actually write gcode commands to make shapes like lines, rectangles with rounded corners, stars, and actual objects like monitors.