COMPLETED · FLIGHT-TESTED

Fixed-Wing UAV Capstone

A 7-foot-wingspan, approximately 5 kg fixed-wing UAV designed, built, and flight-tested as a six-month high-school capstone by a three-person team that I led.

Role: Team lead: design, fabrication, analysis, and flight testing
Duration: Six months, three-person high-school capstone team

SPAN 7 FT
AIRFRAME ~5 KG
INTENDED PAYLOAD ~5 KG
AIRFOIL NACA 4412

Isometric CAD render of the fixed-wing capstone aircraft on a slate-gray background: a single long straight wing crossed by a slim fuselage boom, with a small tail assembly with a vertical fin and swept horizontal surfaces at one end and a rounded, streamlined fuselage pod at the other.

Objective

Design, build, and test a 7-foot-wingspan fixed-wing UAV for an approximately 5 kg intended payload, meeting the capstone's test requirements.

What I made

Designed the wings, electronics bay, and V-tail configuration.
Modeled a four-piece snap-together 3D-printed V-tail with flexible TPU print-in-place hinges, plus 3D-printed wingtips.
Used Autodesk CFD to compare lift and drag behavior, estimate ideal-condition flight time and lift capacity, and inform a wing extension, nose rework, and NACA 4412 airfoil selection.
Built the vacuum formers myself, including designing and tuning their heating element.
Designed the mold-making process and carried out the vacuum forming, changing the skin to vacuum-formed PETG to reduce material use, weight, and fabrication time.
Diagnosed a center-of-mass measurement error during testing and moved the wings forward to improve stability.

Process & iteration

The airframe was built around a carbon-fiber rod with laser-cut balsa ribs and a vacuum-formed skin. Early skin prototypes were vacuum-formed over a peg-board mold; later iterations moved to PETG sheet, and the final airframe skin was vacuum-formed over a steel-mesh surface with a supported forming method (see the vacuum-forming matrix in Evidence). The forming machines themselves have their own page: Vacuum formers.

I used Autodesk CFD to simulate the airframe in flight and find the magnitudes of the force vectors acting on it. I used those results to make the necessary adjustments: a wing extension, a reworked nose, and selection of the NACA 4412 airfoil. Development also included bench-thrust testing, spar-flex testing, and diagnosis of a center-of-mass measurement error that was corrected by moving the wings forward, ahead of the flight described in Result.

Front orthographic CAD render of the same aircraft showing the full wingspan edge-on, with a rounded fuselage pod at the centerline and two thin rod-like features projecting diagonally upward and outward from it. — Front view of the capstone airframe.

Evidence

Vacuum-forming iteration matrix

Vacuum-forming iteration matrix
Version	Vacuum surface	Plastic used	Mold design	Plastic lower method	Form quality	Degree of mold degradation	Form consistency
Prototype 1	Peg board	PVC	3D print	Manual, unsupported	Med	High	Med
Prototype 2	Peg board	PVC	3D print, plaster fill	Manual, unsupported	Med	Low	Med
Prototype 3	Peg board, more holes	PETG	3D print, plaster fill	Manual, unsupported	Med	Low	Med
Prototype 4	Peg board, more holes	PETG	3D print, plaster fill	Manual, unsupported	Med	Low	Med
Final	Steel mesh	PETG	3D print, plaster fill	Manual, supported	High	Low	High

View the original spreadsheet screenshot

The vacuum-forming matrix shows the prototypes moving from PVC to PETG and from a peg-board to a steel-mesh vacuum surface across five iterations; the final entry rates high for form quality and consistency and low for mold degradation.

Limitations

This table is transcribed directly from the original spreadsheet screenshot linked above. The "Vacuum surface" column heading corrects a typo in the source image's own header text; no other values are altered.

Autodesk CFD post-processing screenshot showing a dense field of curved, color-graded streamlines running diagonally across the frame, with a dark-blue low-value region where the streamlines bunch and curve sharply. — Qualitative streamline view from Autodesk CFD post-processing.

Photo of long clear vacuum-formed plastic skin sheets laid out on a concrete shop floor, edged with white tape. — Vacuum-formed PETG skin sheets laid out after forming.

Photo of three students in a classroom holding the completed aircraft horizontally, with its clear ribbed wings and fuselage, black wing center section, twin motors, and black V-tail. — The three-person capstone team with the completed aircraft. **I’m on the far right.**

Result

The aircraft achieved a short successful flight that met the capstone's test requirements. The project was not extended into a longer flight-test campaign after the school project ended.