NXT Drawbot
A custom pen plotter built with LEGO Mindstorms NXT.
Overview
This project was the result of suddenly having large amounts of free time as the world initially shut down for COVID in 2020. Some people baked bread, I decided to build a robot. The NXT platform was what I had available at the time, and I built a cartesian gantry capible with a mount for a whiteboard pen.
The heart of the project was the code - I used NXC, a C based language and compiler built for the NXT, and wrote custom software to read G-code from a file and control the motion of the plotter. I used Fusion 360 to generate G-code, and it handles nearly all of the commands commonly used by 3D printers.
PC Driver Program
In addition to the robot, I built a command line program to control the robot remotely, connection over USB or bluetooth to stream G-Code files to the robot. This sped up testing by removing the step of uploading G-code to the robot, and allowed for larger g-code files to be used. I also wrote the driver program in C++, and made use of the NXT++ library to handle all communications with the NXT.
The code for the project is on Github:
And some additional example drawings are below: