Insomnio · DIANA UCLM

The Insomnio is DIANA’s first aircraft. With it, the team entered the XtraChallenge 2024 in Valencia as team number 8, achieved its first flight and took home the maximum payload award, with more than 200 ping-pong balls on board. In the overall standings it finished last. Both things are true and both are told.

A printed aircraft

What defines the Insomnio is the material: around 90 % of the airframe is 3D-printed in LW-PLA, a foamed PLA that weighs almost half as much as the standard kind. The wings were printed with skin and internal structure fused into a single part. That approach, which the team would abandon in later aircraft in favour of wood and then carbon, is what made it possible to build a complete aircraft in the first year.

Story

PENDING — the account of the design, the build, the flight tests and what happened in Valencia is told by the team. The technical report was submitted before the competition, so it does not record the result.

What went wrong and how it was fixed

PENDING

Technical data

Geometry

Wingspan	2.00 m
Wing area	0.449 m²
Aspect ratio	11.17
Taper ratio	0.25
Mean aerodynamic chord	0.218 m
Wing airfoil	ED216Candidates; AG17, AG19 and ED216. The ED216 was chosen for higher efficiency and a more progressive stall; the AGs were rejected as supercritical and harder to fly.
Tail airfoil	AG17
Planform	Swept-back wing
Tail	V-tail with inverted airfoil; span 0.60 m, dihedral 20°, aspect ratio 3
High-lift devices	Plain flap. The slotted flap was rejected
Control surfaces	Flaperons (ailerons and flaps share the surface)

Masses

Empty mass	1.396 kg (estimated)
Actual payload	Just over 200 ping-pong balls and one billiard ballThe report predicted 1.643 kg with three billiard balls and about 423 ping-pong balls; they did not fit. The report figure is a design value, not the real one.
Maximum take-off mass	Between 3 and 4 kg (report estimate)
Payload prediction	PL [kg] = 0.1857 · ρ + 1.9518

Performance

Stall speed	PENDING
Cruise speed	PENDING
Take-off distance	PENDING

Propulsion

Motor	Emax GT2820 985 KV
Propeller	Aeronaut CAMcarbon Light 10×6Over the APC 10×6E; chosen for a better match with the thrust system and slightly higher hardness and strength.
Power battery	Tattu FunFly 3S 1,300 mAh 100C
ESC	PENDING

Systems

Transmitter	Turnigy 9X, 9 channels
Receiver	PENDING
Control battery	Gens Ace 2S 800 mAh 45C
Servos	MG90S
Flight controller	None. This was the year before flight controllers were introduced
Power supply	5 V UBEC

Structure and manufacturing

Concept	Around 90 % of the aircraft 3D-printed in LW-PLA, with aluminium reinforcements. The wings have skin and internal structure fused into a single printed partXPS (extruded polystyrene) was also studied. LW-PLA won on lightness and strength.
Stabilisers	Same as the wings, with the AG17 airfoil
Landing gear	Off-the-shelf aluminium unit
Test bench	In-house bench with a strain gauge for thrust, current and voltage sensors and a laser rpm sensor, run by an Arduino with PID control and a real-time desktop interface