Telemetry Enclosure

3D-printable enclosure for an 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)	Role
car-2 (active)	228.6 × 223.5 × 57.2 mm	Working redesign — edit these exports
car-1.5 (archive)	228.6 × 223.5 × 57.2 mm	Pristine recovered SolidWorks 2023 STEP baseline

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

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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)
  smooth_floor.py         ← car-2 interior floor cleanup (from car-1.5 baseline)
  update_assembly.py      ← rebuild telem_enclosure_assembly.FCStd after body/lid edits
  face_templates.py       ← 1:1 print templates (legacy compact layout)
  enclosure.py / params.py  ← experimental compact parametric model (not current car-2)
  README.md               ← design notes and print settings
exports/
  README.md               ← version layout guide
  car-1.5/                ← recovered SolidWorks archive (do not edit)
  car-2/                  ← active working folder (legacy-based redesign)
viewer/                   ← lightweight STL web viewer (face select, no FreeCAD GUI)
  server.py
  static/                 ← Three.js UI
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

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. Regenerate the car-1.5 archive (only if source STEP files changed):

   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 exports/car-1.5/.

3. Work in exports/car-2/ — the active redesign. Copy fresh exports from car-1.5/ when resetting, then edit enclosure_body.{FCStd,step,stl} (and lid as needed) in FreeCAD GUI or via the MCP bridge below.

4. Regenerate the README preview GIF after car-2 changes:

   tools/render-venv/bin/python cad/render_gif.py car-2

5. Sync the FreeCAD assembly after body or lid STEP/STL changes:

   ./tools/squashfs-root/usr/bin/freecadcmd cad/update_assembly.py car-2

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

Web viewer (STL + face IDs)

A lightweight browser viewer lives in viewer/ — useful for inspecting exports without opening FreeCAD.

python3 viewer/server.py
# open http://127.0.0.1:8765

Feature	Notes
Model picker	All exports/**/*.stl (defaults to car-2/enclosure_body.stl)
Auto-reload	Polls file mtime every 1.5 s when STL on disk changes
Face IDs	First click on a flat patch assigns #1, #2, …; reuse when re-selected
Orientation	Body sits on its bottom face; +X / +Y / +Z axis labels on the grid
Save	Writes binary STL back to exports/ (creates .bak first)

Regenerate body exports (smooth interior floor, etc.):

./tools/squashfs-root/usr/bin/freecadcmd cad/smooth_floor.py
./tools/squashfs-root/usr/bin/freecadcmd cad/update_assembly.py car-2

The viewer reloads automatically when enclosure_body.stl changes.

Working with Google Antigravity

Use the viewer and chat together so you can point at geometry by name:

1. Start the viewer (python3 viewer/server.py) and open the car-2 body STL.
2. Click faces in the model — each gets a stable number in the sidebar (e.g. Face #2).
3. Tell the agent what to change using those IDs: “smooth face #2”, “remove bosses above face #3”, etc.
4. The agent edits CAD scripts (e.g. cad/smooth_floor.py) or drives FreeCAD MCP (below), re-exports STEP/STL, and the viewer picks up the new mesh.

For live boolean edits in FreeCAD GUI, use the MCP bridge. For quick visual review and face naming, use the web viewer — no FreeCAD window required.

Antigravity MCP (drive FreeCAD from chat)

The repo ships a .cursor/mcp.json pointing to the bundled freecad-mcp bridge. You can add this configuration to your Antigravity setup to use it.

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 Antigravity: add the MCP server — a freecad server should appear.
3. Launch FreeCAD GUI, open exports/car-2/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.