A printable case for the receiver

An outdoor enclosure for the two-board receiver: a pair of Seeed XIAO ESP32-S3s, one antenna on a bulkhead, and a single USB feeding both. Parametric source, so you can change the parts that depend on how yours is put together.

Nobody has printed this yet. The geometry is verified — both meshes are watertight and the dimensions check out — but it has never come off a bed, and one number in it is a guess. stack_h is set to 16 mm and should be the height of your soldered stack, which the header pins and the connector housing dominate rather than the boards. Measure it with calipers and set it before printing.

Download

OpenSCAD source cielotrack-case.scad · 6 KB Base, printable base.stl · 671 KB Lid, printable lid.stl · 130 KB

Change a dimension in the source and re-export:

openscad -D 'part="base"' -o base.stl cielotrack-case.scad
openscad -D 'part="lid"'  -o lid.stl  cielotrack-case.scad

Print it in PETG or ASA

Not PLA. An enclosed box in direct sun passes PLA's softening point and sags; this one lives outdoors in Texas. ASA if it is in full sun, for the UV.

Never carbon-filled filament. Carbon fill is conductive and will detune or shield the antenna. That is the worst kind of failure here, because nothing looks wrong: the board boots, reports healthy, and quietly hears less than it should.

Three perimeters at a 0.4 mm nozzle matches the 2.4 mm walls. No supports needed — the openings are all on vertical faces.

Why it is shaped like this

FeatureReason
Antenna bulkhead on a 35° boss Signal at this site peaks around 30–40° of elevation and falls away on both sides, so an antenna forced vertical points above where the aircraft are. The boss also gives the nut a flat face to seat against, and a hole that is not horizontal does not collect water. It is one parameter — sma_tilt — and most rubber-duck antennas hinge at the base anyway.
One tall USB slot, not two ports The boards are stacked, so their USB-C connectors sit one above the other at the same end. A single slot reaches both and cannot misalign with either. They are flashed one at a time, and with the 5 V rails linked they must never both be plugged in at once.
Vents low on the sides, drain at the bottom Nothing open faces upward. Condensation kills more outdoor electronics than rain does, so it needs somewhere to leave.
Mounting ears outside the box So no screw passes through the sealed volume.
18 mm of slack for the pigtail 1.13 mm coax is lossy at 2.4 GHz and unhappy about tight bends. Short lead, gentle loop.

Wiring it

Two boards, three conductors: data on D9 to D10, a shared ground, and UUSB linked so one USB supply runs the pair. A keyed 3-pin connector — JST-XH suits the 2.54 mm pitch — matters more once the 5 V rails are tied, because a reversible plug can put 5 V on the data pin.

Confirm continuity from the USB connector's 5 V to the UUSB pin with a meter before relying on it.