Free Plot

Free Plot is a small Mac-friendly vinyl cutter control app for HPGL-compatible cutters such as the VEVOR KI-375S.

Build the native Mac app

The native app is a Swift WKWebView wrapper with a Swift local backend. It does not need Electron, npm, or a Python runtime.

cd NativeApp
./build_app.sh

The built app is created at:

Free Plot Native.app

The build script creates a universal macOS binary for Apple Silicon and Intel Macs, including the 2017 iMac Pro.

Run the local web app

The legacy browser workflow is still available for development:

python3 free_plot_server.py

Then open http://127.0.0.1:8787 in your browser.

Current build

• Native Mac app runs without npm, Electron, or Python packages.
• Imports SVG files directly in the browser.
• Previews cut paths on a 285 mm x 360 mm KI-375S work area.
• Supports drag positioning, fit-to-material, scale, rotation, X/Y origin, and X/Y mirroring.
• Supports multi-selecting and deleting cut lines in the preview.
• Exports HPGL/PLT files.
• Scans macOS USB devices and /dev/cu.* or /dev/tty.* serial ports.
• Sends HPGL through the native local backend to the selected serial device.
• Sends directly to USB printer-class cutters such as the detected XILI/STM32 controller.
• Includes a 10 mm square/triangle test cut.

Cutter notes

If your cutter appears as a /dev/cu.* port, start with baud rate 9600. If it does not respond, try 19200 and 38400.

If your cutter appears as STM32 USB DEVICE / XILI, use USB Test or Send USB instead of the serial buttons.

For heat transfer vinyl, use Mirror X before sending.

Import roadmap

The app has native SVG support now. The next layer should add conversion for DXF, PDF, EPS, AI, PLT, and HPGL, most likely by calling Inkscape or another converter when installed.