Deployed units showed the 3.6g micro servo (rated 0.7 kg/cm) whirring, stalling, and burning out — running at its torque limit under cable tension during pan motion, the peak-load moment.

Mechanical fit — the 9g servo's width is absorbable into the casing resize, but its 13.5mm height jump (35.5 vs 22mm) is the binding constraint; the swap recommendation went out conditional on verifying vertical clearance.

Voltage — stalls clustered at peak load; the servo's 4.8V max against a 10.8V pack points to a BEC that may sag voltage under load — a failure that mimics an undersized servo. Worth instrumenting before committing.

Cable routing — a PTFE liner cut friction, but the real fix was geometric: rerouting shortened the lever arm on the servo horn. Where the cable anchored mattered more than the sheathing.

Full technical breakdown — fit dimensions, voltage supply-chain investigation, and the constraint-tradeoff table — available on request.

Every component constrained the fuselage geometry — the internal envelope had to fit the full avionics stack while holding CG placement, vibration isolation, and serviceability.

Fuselage internal cavity — designed around component stack

Full LW-PLA airframe to minimize wing loading: carbon spars carry the primary loads, so infill contributes stiffness only. 15% gyroid chosen for isotropic stiffness and damage tolerance under flight loads.

Added a modular removable nose for direct avionics access without full disassembly — a DFM call for field serviceability. Nozzle temperature tuned to 240°C through controlled test prints.

Modular removable nose — direct access to internal avionics

Print deformation vs nozzle temperature

Fabrication — Frith Lab

Chose the S1223 for high CL at cruise Reynolds, gentle stall at 13° AoA, and thickness for the internal spar: CL max ~2.2, cruise CL ~1.4, 16.98 lbf lift at 22.35 m/s, and a 16% static margin for stable handling.