Drawing machine, powered by Arduino and a CNC shield v3.0 powering 2 LONGRUNER Nema 17 stepper motors.

Design process

Like with many of my projects, I research the parts required, then purchase the parts that I cant make myself online. I then convert these parts into CAD using my digital callipers and design the fittings and attachments into the parts around them. For the arrangement of linear rails and stepper motors, I decided to use an XY gantry belt which meant the moving frame was as light as possible, meaning it could move a lot faster. This design was inspired by the youtuber StuffMadeHere in his video. The limit switch was the most difficult part to model as it was a complex part and important to attach firmly and align correctly to avoid the machine crashing.

The arduino is controlled by GCODE input over serial. I currently use inkscape to generate GCODE from images but I plan to write my own code to do this better including support for two colours. Its driven by 2 stepper motors with driver boards on an arduino cnc shield. Limit switches detect when the pen has reached the home position. The pen is attached to a servo motor and only has two states, up or down, which is controlled by the arduino.