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)

External dimensions: 116 × 86 × 60.5 mm (L × W × H, body + lid)
Printable in PLA or PETG, no supports required except for I/O wall cutouts.

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Repository layout

README.md                        ← you are here
telem-enclosure-components.pdf   ← component datasheets / spec reference
cad/
  params.py             ← all dimensions as named constants
  enclosure.py          ← FreeCAD Python build script
  render_gif.py         ← turntable GIF renderer (needs tools/render-venv)
  README.md             ← detailed design notes, print settings, clearance table
exports/
  enclosure_body.step / .stl
  enclosure_lid.step   / .stl
  enclosure_preview.gif            ← turntable animation (regenerate with render_gif.py)
  telem_enclosure_assembly.FCStd   (body + lid + reference bricks in FreeCAD)
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 — regenerate the 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. Run the build script:

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

   This writes exports/enclosure_body.{step,stl}, exports/enclosure_lid.{step,stl},
   and exports/telem_enclosure_assembly.FCStd, and prints a clearance report.

3. Tweak dimensions in cad/params.py and re-run step 2.

See cad/README.md for full design notes, a component clearance
table, mounting hole specs, 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, then ask the agent to make changes; it drives FreeCAD live
   over the Unix socket while cad/params.py remains the source of truth.

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.