Completed
2D CNC Machine (Drawbot)
G-code controlled drawing robot with motion planning algorithms
This project brings digital designs into the physical world through a custom-built CNC drawing machine. By implementing G-code parsing and motion control algorithms from scratch, the system translates vector graphics into precise mechanical movements.
System Architecture
The drawbot consists of three main subsystems:
Mechanical: XY gantry system using timing belts and linear rails for smooth, accurate motion. A servo-controlled pen lift mechanism enables drawing and positioning moves.
Electrical: Stepper motor drivers providing the current and control signals needed to drive NEMA 17 motors. An Arduino microcontroller orchestrates all motion.
Software: Embedded C/C++ firmware parsing G-code commands and generating precisely timed step pulses.
G-Code Parsing
The firmware implements a G-code interpreter supporting standard commands:
- G00/G01: Rapid positioning and linear interpolation moves
- G02/G03: Circular interpolation (clockwise and counterclockwise arcs)
- M03/M05: Pen up and pen down commands
- G90/G91: Absolute and relative positioning modes
Motion Planning
Bresenham Line Algorithm: Determines which steps to take on each axis, ensuring the mechanical path closely approximates the desired line.
Acceleration Profiles: Trapezoidal velocity profiles for smooth motion.
Positioning Resolution: ±0.1mm accuracy across 300mm × 300mm work area.