Plot SVG with AxiDraw

Everything else in this pack prepares art. Plot SVG with AxiDraw is where the machine actually moves. Give it a plot-ready SVG string and it hands the file to axicli, the AxiDraw command-line tool, which drives the pen across the paper - speed, layer, pen delays and all. It's an output node: no outputs to wire onward, just a status string reporting what happened. This is the physical payoff at the end of the pipeline.

You need three things to use it: the SVG (ideally from Optimize SVG with vpype, because raw tracers plot terribly), the AxiDraw software with axicli on your PATH, and a real AxiDraw connected over USB. No plotter, no dice - this node does nothing virtual.

How it works

The node writes your svg_string to a temporary file and runs axicli with the settings you pick. The interesting inputs:

• layer (1–8, default 2) - which SVG layer to plot. AxiDraw software plots SVG layers in order, and layer selection is how multi-layer/multi-color plots work: separate your drawing into layers, then run this node once per layer, swapping pens between runs.
• pen_up_speed (1–100, default 75) and pen_down_speed (1–100, default 25) - how fast the carriage moves with the pen raised versus lowered. Fast pen-up moves save time; slow pen-down keeps line quality. 75/25 is a sane starting point.
• pen_up_delay / pen_down_delay (ms, default 0) - pauses so ink can flow or dry before the next move. Useful for felt-tips that drag. Leave at 0 until you see a problem.
• wait_for - an optional string input that accepts a connection, letting you sequence the plot after other work completes (handy when you want a plot to start only after an upload or a video render finishes).

When the run finishes, the node calls axicli --mode align to disengage the plotter so the pen lifts and the motors release - you shouldn't have to babysit the end of a job. status reports "Plot completed successfully." or returns an error message as the string.

Install

It's in the ComfyUI PenPlotter pack. ComfyUI Manager → search "ComfyUI PenPlotter", or:

cd ComfyUI/custom_nodes
git clone https://github.com/wouterverweirder/comfyui-penplotter

Restart ComfyUI. Beyond the pack's usual requirements (numpy>=2.3.4, opencv-python, numba, vpype, websockets, requests, qrcode[pil], and the AxiDraw API installed from a URL zip), this node needs the full AxiDraw software so axicli exists on your PATH.

Common issues

• "axicli command not found" - the most common failure. The Python API alone isn't enough; install the AxiDraw software and make sure axicli resolves from the same environment ComfyUI runs in.
• Plot runs but nothing draws - pen not down or ink not flowing. Check pen_down_speed, the pen holder, and that your SVG actually has stroke (fill-only SVGs won't plot).
• Wrong layer plotted - you're seeing layer 1 when you expected layer 2, or vice versa. Set layer to match the layer the drawing lives on.
• Interrupting a plot is slow or the pen stays down - the pack hooks ComfyUI's interrupt to terminate the running subprocess and disengage, but it's best-effort. If the pen is down after a Cancel, run Disengage Plotter manually.

One honest warning: this node talks to physical hardware over USB, and subprocess-based plotting can be finicky about ports and drivers. It's not as polished as the official AxiDraw Inkscape extension - it's a ComfyUI-native convenience wrapper, and the killer feature is that your whole image-to-plot workflow stays in one graph.