A 3D pen-plotter simulator in the browser. Drop in an SVG and watch a little AxiDraw-style machine draw it on virtual paper — arm sliding, pen lifting, stepper motors whirring. It doesn't make anything real but it's nice to watch.
Drag any SVG file onto the page and it loads onto the plotter. Then:
- ▶ Plot / ❚❚ Pause — run or pause the drawing
- Reset — rewind the plot and send the pen home (the sheet keeps its ink until the next plot starts). By default every new plot or loaded SVG takes a clean sheet; tick Reuse paper to keep the ink instead — plot over it, run layers separately, or stack different SVGs on one sheet, clearing only via the paper's Fresh button or by picking a new sheet/type/size
- Speed — 1× (real time) up to 1000× for the impatient
- Plot — draw all layers, or just one
- Pens — every layer starts with its own fresh 0.5 fineliner in the SVG's color; each row edits its pen directly (color, pen type, tip size). Click a pen in the caddy to load that actual pen instead — color, tip, and ink level come with it, and layers sharing a caddy pen share its ink. Customize a borrowed caddy pen and the layer quietly gets its own copy (the caddy pen is untouched). Each pen type has its own line character (the marker blobs, the ballpoint dry-starts, the brush swells) and its ink runs down as you plot — levels persist between visits. Fresh replaces a dead pen, or untick Ink simulation for perfect ink with none of that. Pausing a plot unlocks the pens, so you can swap or recolor mid-drawing — the machine picks up the change when you resume. (The paper stays locked until the plot is done: no sliding a new sheet under half a drawing.)
- Paper — choose a paper type in the panel or click the stack beside the machine: bristol, watercolor (toothy), cheap copy (bleeds a little), or black card (that's what the gel and metallic pens are for). The color picker overrides the sheet color, and the size dropdown swaps in a different standard sheet (A5 up to Tabloid) — the machine resizes to fit.
- Clock — estimated plot time ticks next to the mute button: it runs at the simulation speed, so whatever the Speed setting, it approximates how long the plot would take on a real machine (pausing freezes it; finishing leaves the total showing).
- Layer colors — pick a pen color per layer before you start (Inkscape layers are detected automatically)
- Keep original size — plot the SVG at its native millimeter size from the machine's home corner instead of auto-fitting the sheet. Anything past the edge gets clamped by the machine's travel limits, each axis independently — the pen drags along the edge exactly like a real plotter running out of rail, which is precisely the mistake this lets you preview
- 🔊 — mute the motor and servo sounds (they only play at 1× speed anyway)
- F — toggle a free-fly camera: the mouse locks for looking around and WASD + E/Q fly you through the scene; press F (or Esc) to return to orbit
- H — hide/show the whole interface (handy for a clean screenshot)
Recently plotted files are remembered so you can replay them. On a first visit the Recent list starts with a built-in sample, so there's something to plot before you have an SVG of your own.
Copyright (C) 2026 Frank Force.
Released under the GNU General Public License v3.0 — see LICENSE. You're free to use, study, share, and modify it, but any version you distribute has to stay open source under the same license.