update the plans

airframe/openscad/nacelles/nacelle_pod_50mm_tandem.scad

@@ -433,6 +433,17 @@ SHAFT_CONDUIT_ID=   3.5;   // [mm] conduit inner bore
 INLET_BELL_L    =  27.5;   // [mm] inlet bell axial length (was 22.0 × 1.25)
 INLET_BELL_FLARE=   3.0;   // [mm] extra flare radius at intake lip
 
+// ── Circular intake exterior blend ─────────────────────────────────────────
+// The imported canonical shell is asymmetric at the nose.  Intersecting that
+// shell with a circular bore therefore leaves an oblique, elliptical-looking
+// intake rim even though the duct itself is round.  This fairing supplies a
+// planar circular lip and blends it into the existing shell over the same
+// 27.5 mm intake transition.  The bore and its area are unchanged.
+INTAKE_LIP_R       = EDF_BORE_R + WALL_T;  // [mm] circular outer lip radius
+INTAKE_BLEND_R_PEAK = 38.2;                // [mm] below measured shell maximum
+INTAKE_BLEND_R_END = 27.0;                 // [mm] buried in the duct wall
+INTAKE_BLEND_L     = 90.0;                 // [mm] reaches the thrust-tube station
+
 // ── Navigation light + harness exit (1.25× scale Z values) ───────────────────
 // Rev S1 (2026-07-04, TODO §1.1.3.5): the WS2812C position light was moved from
 // the INBOARD (pylon) face to the OUTBOARD (far) face, and its signal wire was
@@ -588,6 +599,48 @@ module inlet_bellmouth() {
 }
 
 
+// =============================================================================
+// ── Module: circular_intake_fairing ─────────────────────────────────────────
+// =============================================================================
+// Additive rotationally symmetric exterior fairing.  Its front annulus is
+// planar at Z=0, so the intake opening is circular in the side and front views.
+// The outer profile first reaches the measured shell envelope, then tapers
+// back into the duct wall before the thrust-tube station.  Its termination is
+// therefore buried instead of exposing a circumferential cap at the shell.
+module circular_intake_fairing() {
+    N_STATIONS = 64;
+
+    rotate_extrude(angle = 360, convexity = 4)
+        polygon(
+            points = concat(
+                [[0, 0], [INTAKE_LIP_R, 0]],
+                [
+                    for (i = [0 : N_STATIONS])
+                    let(
+                        z_frac = i / N_STATIONS,
+                        rise_frac = min(z_frac / (60 / INTAKE_BLEND_L), 1),
+                        fall_frac = max((z_frac - (60 / INTAKE_BLEND_L))
+                                / (1 - (60 / INTAKE_BLEND_L)), 0),
+                        rise_smooth = rise_frac * rise_frac
+                            * (3 - 2 * rise_frac),
+                        fall_smooth = fall_frac * fall_frac
+                            * (3 - 2 * fall_frac),
+                        r_at_shell = INTAKE_LIP_R
+                            + (INTAKE_BLEND_R_PEAK - INTAKE_LIP_R)
+                            * rise_smooth,
+                        r_outer = r_at_shell
+                            + (INTAKE_BLEND_R_END - r_at_shell)
+                            * fall_smooth,
+                        z_abs = z_frac * INTAKE_BLEND_L
+                    )
+                        [r_outer, z_abs]
+                ],
+                    [[0, INTAKE_BLEND_L], [0, INTAKE_BLEND_L + 0.5]]
+            )
+        );
+}
+
+
 // =============================================================================
 // ── Module: sleeve_retention_bosses ─────────────────────────────────────────
 // =============================================================================
@@ -1016,6 +1069,12 @@ module nacelle_pod(swirl_dir = SWIRL_DIR) {
                 // (Intake bell-mouth is now SUBTRACTIVE — see Zone B,
                 //  inlet_bellmouth(); TODO §1.1.3.4.)
 
+                // ── Circular intake exterior fairing ─────────────────────
+                // Establishes a round planar lip before the circular bore and
+                // blends into the canonical shell over the existing intake
+                // transition; it does not change the internal duct diameter.
+                circular_intake_fairing();
+
                 // ── CG-pivot keyed 8 mm spar hubs (at PIVOT_Z, Y=0) ──────
                 pivot_x_face_boss();
 

docs/plans/2026-08-25-002-finish-airframe-components-plan.md

@@ -520,6 +520,70 @@ open items, not scoped further by this plan:
 
 ## Scope Boundaries
 
+## U7. CF-PETG printability and flightworthiness audit
+
+**Goal:** Review every active `.scad` source and published STL in
+`airframe/openscad/` and `airframe/stls/` for fabrication in 20% CF-PETG,
+starting with `cargo_sect_shell24_2mm_repaired.stl`. The audit must separate
+intended solid material from intentional cavities, recesses, mortises,
+passthroughs, sockets, and mating clearances, and must not treat a global
+watertight result as proof that local wall thickness or interface geometry is
+printable.
+
+**First checkpoint:** `cargo_sect_shell24_2mm_repaired.stl`, followed by
+`head_cargo_splice_collar.stl`, `cargo_middle_splice_collar.stl`, and
+`middle_rear_splice_collar.stl`. The supplied `bow_sensor_faceplate.stl` is
+included as the first small-part control. The review expands to all active
+OpenSCAD/STL artifacts only after this checkpoint produces a repeatable report
+format and identifies the canonical source for each artifact.
+
+**Required evidence for each artifact:**
+
+- [ ] Mesh loads, is non-empty, and passes boundary-edge, non-manifold,
+  winding, degeneracy, and connected-body checks.
+- [ ] Bounding box, volume, mass bracket for 20% CF-PETG, and print orientation
+  are recorded; structural parts use at least 4 perimeters and 40% infill.
+- [ ] Local wall thickness is sampled at the shell, floors, roofs, ribs, boss
+  annuli, collar walls, and other load paths. Any value below the applicable
+  20% CF-PETG design minimum is a finding, not silently accepted.
+- [ ] Every cavity, recess, mortise, passthrough, bore, socket, and interface
+  is classified as intentional or unintended, with its mating artifact and
+  clearance requirement identified.
+- [ ] Unsupported overhangs, horizontal holes, bridges, trapped support
+  volumes, thin islands, sharp first-layer edges, and print-split joints are
+  assessed for the selected FDM orientation.
+- [ ] Flight-critical parts receive a load-path disposition. A mesh-only pass
+  is not a flightworthiness approval; material data, print orientation,
+  coupon testing, fastener/adhesive details, and assembly inspection remain
+  explicit gates where not verified.
+
+**Cargo-shell first-pass findings to resolve or document:**
+
+- [ ] Confirm the nominal 2.0 mm foam-fill skin thickness against local mesh
+  measurements, including the cargo aperture, joint faces, wing-root
+  mortises, spar bore, GPS/camera features, ribs, bosses, and splice-collar
+  seats.
+- [ ] Confirm which internal volumes are intentionally open for payload/cable
+  routing and which are meant to be solid CF-PETG, including the shell's
+  merged structural positives and negative cutters.
+- [ ] Verify the supplied splice collars are printable, correctly oriented,
+  and mechanically coupled to the shell; specifically check collar wall
+  thickness, bore/shoulder geometry, trapped cavities, and bonded joint
+  surfaces.
+- [ ] Record mass and CG deltas for any geometry disposition that changes the
+  current flight configuration.
+
+**Verification contract:** run `python3 tools/validate_stls.py` for the
+published inventory, run the shell-specific structural checks, and retain a
+machine-readable audit report with artifact path, measured values, findings,
+and `PASS`, `CONDITIONAL`, or `BLOCKED` disposition. A `PASS` requires both
+global mesh integrity and local printability evidence; unverified material or
+flight-load assumptions remain `CONDITIONAL`.
+
+**Dependencies:** U7.1 cargo shell measurement and intent map; U7.2 splice
+collar interface review; U7.3 full OpenSCAD/STL inventory; U7.4 corrective
+geometry and regeneration; U7.5 looped QA and flightworthiness closeout.
+
 **In scope:** Phase 5 units U1–U6 (full implementation); Phase 6/7/9/11
 (capture and light triage only, not implementation, per the owner's request
 for a plan covering "the rest of the airframe components").

docs/plans/2026-08-26-001-nacelle-esc-intake-integration-plan.md

@@ -0,0 +1,210 @@
+---
+title: "plan: Integrate nacelle ESCs and refine circular intakes"
+date: 2026-08-26
+plan_type: feature+mechanical
+execution: geometry+serviceability
+---
+
+# Plan: Nacelle ESC integration and circular intake refinement
+
+**Target repo:** Serenity-UAV
+
+**Scope:** Integrate two Open-Secure-ESC boards into each tandem-EDF nacelle,
+define a repeatable nacelle/ESC/EDF service sequence, compare nacelle removal
+against spar removal, and refine the nacelle intake to a circular Ø50 mm flow
+path with a constant-area transition into the EDF housing.
+
+## Confirmed inputs
+
+- Two ESC boards per nacelle, one at each EDF station.
+- The committed KiCad board is 32.0 × 66.1 mm with 1.6 mm PCB thickness.
+- The board has no mounting-hole pattern and no encoded component-height or
+  thermal-interface data; these must be measured or sourced before a bracket is
+  frozen.
+- The existing BOM entry describing a generic 25 g ESC mounted in a 20 mm hub
+  bore is stale and must not drive geometry.
+- The nacelle uses a 50 mm internal duct, removable stator and aft-spider
+  sleeves, an 8 mm rotating spar, F688ZZ root bearing, MF128ZZ wingtip bearing,
+  and two fixed Ø7 mm wing EDF conduits.
+- Normal service should remove the nacelle before either ESC is removed.
+- Intake target is a circular Ø50 mm flow section. A Ø50 mm section has area
+  $A = \pi(25\,\mathrm{mm})^2 \approx 1,963.5\,\mathrm{mm}^2$.
+
+## Architecture decision to validate
+
+Use nacelle-first service as the preferred architecture:
+
+1. Power-isolate the aircraft.
+2. Disconnect the wing-to-nacelle harness at the nacelle-off boundary.
+3. Release accessible nacelle axial retention and the keyed spar interface.
+4. Slide the nacelle off the rotating spar while leaving the spar, bearings,
+   wing, servo indexing, Hall reference, and wing conduits installed.
+5. Remove both EDF assemblies and their associated ESCs on the bench.
+
+Evaluate spar removal as a fallback only. It would disturb bearing seats, servo
+indexing, Hall calibration, harness routing, and wing access, so it must be
+quantified rather than assumed equivalent.
+
+The final interface must use a positive-stop shoulder and keyed torque transfer.
+Friction-fit-only retention is prohibited by the airframe fabrication rules.
+
+## Implementation units
+
+### U1 — Verify the ESC mechanical envelope
+
+Inspect the committed files under
+`Open-Secure-ESC/builds/6s/50A/CAN_485_faraday/kicad/` and extract:
+
+- Board outline and thickness
+- Component heights on both sides
+- Connector and cable projection
+- Mounting-hole status
+- Thermal surfaces and cooling requirements
+- Actual mass and center-of-gravity contribution
+
+Add a machine-readable report and fail the fit gate when a critical value is
+unknown. Reconcile the 32.0 × 66.1 mm committed outline with any stale
+25.4 × 60.1 mm documentation before bracket design.
+
+### U2 — Audit current nacelle and EDF service geometry
+
+Build a service-envelope model from:
+
+- `airframe/openscad/nacelles/nacelle_pod_50mm_tandem.scad`
+- `airframe/openscad/nacelles/edf_stator_sleeve.scad`
+- `airframe/openscad/nacelles/edf_aft_spider_sleeve.scad`
+- `airframe/openscad/port_tilt_spar_assembly.scad`
+- `airframe/openscad/wings/wings_s1223_revo.scad`
+- `airframe/FreeCAD-scripts/serenity_assembly.py`
+
+Include EDF1 and EDF2, thrust tube, stator spar fairing, nozzle, keyed hubs,
+shaft and bearings, harness port, tool envelopes, and both fixed wing conduits.
+Resolve the conflicting EDF1 insertion/tool-access descriptions by checking
+the actual motor and fastener access. Preserve the documented EDF2 nozzle-end
+retention sequence.
+
+### U3 — Compare removal architectures
+
+Create a parametric motion study for:
+
+- **Option A: nacelle off spar.** Verify inboard and outboard removal paths,
+  axial retention, keyed torque transfer, positive stops, harness release, and
+  clearance from wing, pylon, bearings, spar, nozzle, and thrust tubes.
+- **Option B: spar out of bearings.** Quantify wingtip/root bearing access,
+  servo uncoupling, Hall recalibration, angular re-indexing, harness disruption,
+  and reassembly inspection.
+
+Select the direction with measured clearance and the lowest disturbance to the
+calibrated rotating assembly. Do not move the wing or bearing seats solely to
+make the service path easier to model.
+
+### U4 — Add parametric ESC seats and service interfaces
+
+Create an OpenSCAD source for one ESC seat per EDF station, mirrored for port
+and starboard. Include:
+
+- Board envelope plus measured fit tolerance
+- Positive longitudinal and lateral stops
+- Captive fasteners or a documented removable retention method
+- Vibration restraint
+- Connector and wire-bend relief
+- Cooling clearance and thermal path
+- Access only available after nacelle removal
+
+Add separate EDF1 and EDF2 lead exits and strain relief while preserving the
+fixed double-Ø7 mm wing conduits. Do not route high-current ESC conductors
+through the rotating spar; its hollow route remains reserved for the nav-light
+wiring.
+
+Register the ESCs, seats, retainers, and service hardware in the FreeCAD
+assembly using the existing nacelle-local transform and tilt functions. Update
+the BOM only after the physical board data and printed geometry are verified.
+
+### U5 — Refine the circular intake
+
+Measure the published port and starboard nacelle meshes at the intake. Compare
+the full-resolution external silhouette against the official blueprint pack.
+Classify the apparent elliptical feature as an actual flow boundary, an
+outer-shell projection, or a legacy/intermediate artifact before cutting mesh.
+
+Preserve the canonical outer mold line and the existing internal EDF, stator,
+spar-fairing, and wiring geometry unless measurements prove interference.
+Implement a circular Ø50 mm internal flow entrance and a constant-area
+transition into the EDF housing.
+
+For sampled axial stations, report:
+
+- Section shape
+- Effective flow area
+- Equivalent/hydraulic diameter
+- Wall thickness
+- Deviation from 1,963.5 mm²
+- Local slope/curvature changes
+- Obstruction from spar fairing, wiring, or structural features
+
+An external expanding bellmouth may preserve the canonical silhouette, but it
+must not be described as constant-area flow. The constant-area requirement
+applies to the effective internal duct.
+
+Validate the intake for 20% CF-PETG printability, including lip thickness,
+overhangs, trapped supports, print split joints, and EDF insertion clearance.
+If the canonical shell and exact constant-area path conflict, preserve the
+canonical exterior and record the aerodynamic deviation as conditional for
+owner review.
+
+#### Fine tune the circular intake flange to the canonical shell.
+The current shape intersects the canonical curve at multiple z values, creating a wavy profile.
+
+### U6 -- Verify ESC cable clearance for rotation through full tilt range.
+
+ESC wires are forward of the pivot, and therefore will experience tension and binding during the nacelle tilt.  the 10AWG wires need room to move.
+
+### U7 — Regenerate and close out
+
+Regenerate port/starboard nacelle geometry and new ESC hardware through the
+existing source/Makefile pipeline. Re-bake only artifacts that are not already
+in hull coordinates. Update the owning WBS/TODO files, root tracking files,
+`PROJECT_INDEX.md`, service documentation, and `current-specification/bom_revS.csv`.
+
+Record mass and CG changes, print orientation, material, wall thickness,
+fasteners, and unresolved primary-source gates.
+
+
+## Verification contract
+
+1. The ESC report matches the committed 32.0 × 66.1 mm board outline and
+   explicitly reports missing height, mounting-hole, and thermal data.
+2. The selected nacelle-removal path has zero solid overlap at all sampled
+   positions and leaves the wing, spar, and bearings installed.
+3. Both ESCs remain inaccessible until nacelle removal and are removable on the
+   bench without dismantling the constant-area duct or damaging EDF wiring.
+4. EDF1 and EDF2 installation/removal sequences are executable with documented
+   tool directions and fasteners.
+5. Run the changed-geometry gates:
+
+   ```text
+   python3 tools/validate_stls.py
+   python3 tools/wing_root_deconflict.py
+   python3 tools/wing_internal_clearance.py
+   python3 tools/wing_spar_carrythrough.py
+   python3 tools/cargo_bay_envelope.py
+   python3 tools/landing_gear_wing_clearance.py --proud
+   ```
+
+6. The intake report confirms circular Ø50 mm sections, approximately
+   1,963.5 mm² effective area, documented bounded deviation, smooth transition
+   into the EDF housing, and no unacceptable local obstruction.
+7. Headless OpenSCAD and FreeCAD renders are inspected at cruise, intermediate,
+   and hover tilt configurations.
+8. New Python tooling passes syntax/static analysis and every external claim is
+   reconciled against the appropriate `REFERENCES.md` entry.
+
+## Open gates
+
+- ESC component-height envelope, connector projection, mounting arrangement,
+  mass, and thermal interface.
+- Final nacelle removal direction and axial-retention hardware.
+- EDF1 motor insertion direction and tool reach.
+- Intake measurement tolerance and any CFD or bench-flow evidence required to
+  support a no-separation claim.
+- Printed-part and airframe mass/CG deltas after geometry is frozen.