The wing generator

The ✨ GEN's → NACA wing tool turns a couple of aerofoil numbers into a ready-to-cut foam wing panel — the bread-and-butter of RC and model aircraft. It cuts as a 4-wire morph: the left wire follows the root aerofoil, the right wire follows the tip, and the hot wire rules the smooth surface between them.

What the NACA 4 digits mean

A NACA 4-digit aerofoil like 2412 encodes three things:

• 1st digit — camber: maximum curve of the mean line, in % of chord. 2 = 2%. A 0 here means a symmetric section (no camber).
• 2nd digit — camber position: where that max camber sits, in tenths of chord. 4 = 40% back from the leading edge.
• Last two digits — thickness: maximum thickness in % of chord. 12 = 12% thick.

So 2412 = 2% camber at 40% chord, 12% thick. 0009 = symmetric, 9% thick. 0012 = symmetric, 12% thick.

Picking an aerofoil

• Trainer / sport wing: 2412 or 4412 — gentle camber, lifty, forgiving.
• Aerobatic / 3D: 0012–0015 symmetric — flies the same inverted as upright.
• Tail surfaces (stab / fin): thin symmetric 0009–0010.
• Fast / pylon: thinner sections (8–10%) for less drag; thicker (12–15%) for slow, floaty flight and easier building.

Taper, sweep & washout

• Taper — set a smaller tip chord than root chord. Tapered wings are efficient and look great; a taper ratio (tip ÷ root) around 0.5–0.7 is a sweet spot. Equal chords = a constant-chord (Hershey-bar) wing, the easiest to build.
• Different tip aerofoil — blend from a thicker root to a thinner tip for strength at the root and efficiency at the tip. Leave the tip blank to use the same section.
• Sweep — sweeps the leading edge aft along the span. A little looks fast and can help stability; a lot changes the handling. 0° is fine for most models.
• Washout — twists the tip down a couple of degrees relative to the root, so the tip keeps flying after the root has stalled. 2° of washout gives a much gentler, more controllable stall — highly recommended on trainers.

How it cuts

The panel loads as a 4-axis (X/Y + U/V) morph in a block sized to your chord × thickness × span, centred in the cutter. Hot-wire a foam wing this way and you get a clean, true surface in one pass. For a symmetric block you can flip and cut the second panel the same way. Choose a foam to suit: EPS is light and cheap; XPS (extruded) holds detail and sands beautifully; EPP survives crashes.

From panel to wing

The generator makes one half-panel. A full wing is two panels joined at the root, usually with a few degrees of dihedral (the V-angle between them) for roll stability — that's set when you glue them, not in the cut. Most builders also add a spar (a carbon tube or hardwood strip in a slot) for strength, and skin the foam with tape, brown paper or fibreglass. The cut core is your starting point.

Related

See Designing wings & aerofoils for the deeper theory, Morphing two profiles for how the 4-wire root→tip blend works, and the foam materials guide for choosing your core.