CNC Whiteboard Plotter
Solo build: design, fabrication, firmware, and toolpath software
- Gantry Design
- Motion Control
- Automatic Tool Changer
- Firmware
- CAD
TL;DR
A wall-scale, 3-axis gantry plotter that draws across a 1.5 m × 1.5 m whiteboard and swaps its own markers mid-drawing through an automatic tool changer, enabling multi-colour output. It is step one of a bigger idea (networked whiteboards that reproduce each other's drawings in real ink) and the build-log project: motion control, repeatability, and a tool-change mechanism, documented honestly.
The problem
Brainstorming sessions can be hard, and doing them over Teams, as COVID forced us to, makes it worse. I wanted a way for the team to feel more connected when running them online.
The vision
Imagine a whiteboard on your wall, with a small screen in the top right showing the other members of your session live. You can talk to each other, but you also draw on the whiteboard. When you do, the board scans your drawing and instantly draws it, in the same place, on everyone else's whiteboard. A fully interactive session, showing real ideas, in real ink, in real time. The first objective was to get an autonomous whiteboard working. This machine is that step.
Output
The proof is on the board. The machine draws real toolpaths at wall scale: dense isometric patterns that expose any repeatability error instantly.
The engineering challenge
Drawing at whiteboard scale stresses different things than a desktop plotter: a long gantry has to stay stiff enough for clean lines across a 1.5 m span, the motion system has to be smooth at speed for long strokes, and multi-colour drawing means the machine has to pick up and put down markers itself, repeatably, without human intervention.
System architecture
The tool changer
The signature mechanism: the plotter parks its current marker and picks up the next colour on its own.