Self-built · Motion Control
CNC Pencil Writing Machine
What it is
A two-axis CNC machine built mostly from scratch: wood frame, purchased linear rails and stepper motors, custom motion control firmware. It moves a pen across paper under software control.
The mechanical side came together faster than expected. The harder problem was the software. I wrote the motion control code myself, handling stepper sequencing, coordinating both axes smoothly without missed steps or stuttering, and managing pen lift between moves.
The next step was upgrading it to parse G-code, which would have turned it from a proof of concept into a machine that could trace any vector image. That's still on the list.
What it showed me
Coordinating two axes in real time is a control problem as much as a mechanical one. Getting smooth, predictable motion out of cheap stepper motors is mostly a software tuning exercise. That instinct toward the control layer is what drew me toward autonomy and robotics: the interesting problems are rarely the structural ones.