Compact Telemetry Enclosure

3D-printable enclosure for a compact airborne / ground-station telemetry stack:

Component	Notes
Raspberry Pi 4B	Bottom layer, M2.5 standoffs
RFD900A telemetry radio	Adhesive-mounted to left interior wall
Quectel EG25-G LTE module	4× M3 wall-boss screws via Mini PCIe-to-USB adapter
Adafruit DS3231 RTC	Sits directly on Pi GPIO pins (no separate mount)

Version	Dimensions (L × W × H)	Source
car-1.5 (active)	228.6 × 223.5 × 57.2 mm	Recovered SolidWorks 2023 STEP
car-2 (archived)	116 × 86 × 60.5 mm	Parametric FreeCAD rebuild

Printable in PLA or PETG. See exports/README.md for file layout.

---

Repository layout

README.md                        ← you are here
telem-enclosure-components.pdf   ← component datasheets / spec reference
cad/
  import_legacy.py        ← import car-1.5 STEP → exports/car-1.5/
  analyze_step.py         ← inspect bounding boxes and hole sizes
  render_gif.py           ← turntable GIF (arg: car-1.5 or car-2)
  face_templates.py       ← 1:1 print templates (car-2)
  enclosure.py / params.py  ← parametric car-2 rebuild script
  README.md               ← design notes and print settings
exports/
  README.md               ← version layout guide
  car-1.5/                ← recovered SolidWorks design (active)
  car-2/                  ← parametric compact redesign (archived)
tools/
  freecad-mcp/          ← contextform/freecad-mcp bridge for Cursor MCP
  render-venv/          ← gitignored Python venv for render_gif.py
  FreeCAD.AppImage      ← gitignored (download separately, see below)
  squashfs-root/        ← gitignored (extracted AppImage runtime)
.cursor/
  mcp.json              ← FreeCAD MCP server config for Cursor

Quick start — import the recovered model

1. Get FreeCAD 1.0+ — either via apt or AppImage:

   sudo apt install freecad          # Ubuntu / Debian
   # or download the AppImage from https://freecad.org/downloads.php
   # and place it at tools/FreeCAD.AppImage

2. Import the car-1.5 STEP files into exports/car-1.5/:

   freecadcmd cad/import_legacy.py
   # or, using the local AppImage:
   echo 'exec(open("cad/import_legacy.py").read())' | \
     ./tools/squashfs-root/usr/bin/freecadcmd

   Reads exports/car-1.5/SoftwareEnclosure*Car1.5.STEP, aligns the body to origin, and writes enclosure_body.{FCStd,step,stl}, enclosure_lid.*, and telem_enclosure_assembly.FCStd into the same folder.

3. Make modifications in FreeCAD GUI (or via the MCP bridge below), then re-export from FreeCAD or update the source STEP files and re-run step 2.

4. Regenerate visuals after changes:

   tools/render-venv/bin/python cad/render_gif.py car-1.5

See cad/README.md for design notes and print settings.

Cursor MCP (drive FreeCAD from chat)

The repo ships a .cursor/mcp.json pointing to the bundled freecad-mcp bridge.

1. Install the Python mcp package (already done if you cloned this repo with the venv):

   cd tools/freecad-mcp && python3 -m venv .venv && .venv/bin/pip install mcp

2. In Cursor: Settings → MCP → reload — a freecad server should appear.
3. Launch FreeCAD GUI, open exports/car-1.5/enclosure_body.FCStd or enclosure_lid.FCStd, then ask the agent to make changes; it drives FreeCAD live over the Unix socket.

Printing

	Body	Lid
Material	PETG (preferred) or PLA	PETG or PLA
Layer height	0.2 mm	0.2 mm
Infill	20% gyroid	20% gyroid
Walls	3 perimeters	3 perimeters
Supports	Tree — I/O cutouts only	None
Orientation	Open side up	Top face down

Use M2.5 brass heat-set inserts in the Pi standoffs and lid-corner screw bosses
for reusability. M3 × 6 mm self-tappers secure the Quectel adapter to its posts.