Step-by-Step Guide: Building a Large XPS Foam Glider (1m–1.2m Wingspan)
This guide helps you build a large hand-launch or tow-line glider using 2.5cm thick XPS foam. This design is more durable and suited for longer glides and potential RC conversion.
How to Thin Down 2.5cm XPS Foam
Since the foam is thicker for some parts, you can thin it down using:
🔹 Hot wire cutter – Best for cutting precise, even layers.
🔹 Hand sanding – Use coarse grit (80–120) to remove bulk, then smooth with fine grit (220–400).
🔹 Surform planer or rasp file – Quickly removes excess foam, then sand smooth.
🔹 Router or hot knife – If using power tools, keep the speed low to avoid melting.
For stronger, lightweight wings, consider hollowing out the inside or shaping a basic air foil instead of using a flat wing.
Step 1: Designing & Cutting the Foam Parts
Glider Dimensions
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Wing: 1m–1.2m wingspan, ~150mm–200mm chord
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Fuselage: 500mm–600mm long, ~40mm wide
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Horizontal Stabilizer: 250mm–300mm wide, ~80mm deep
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Vertical Stabilizer (Fin): 100mm–150mm high
🔹 Cut the wing into two halves to create a slight dihedral (~5°–10°) for stability.
🔹 Thin the wing down to ~10mm–15mm at the edges to improve aerodynamics.
🔹 Taper the leading edge (rounded) and trailing edge (thin) using sanding or a planer.
Step 2: Wing Reinforcement & Assembly
🔹 For better strength, cut a slot in the middle of the wing and insert a carbon fibre rod or wooden spar.
🔹 If using two wing halves, glue them at an angle (dihedral) of 5°–10° for self-stabilization.
🔹 Use lightweight tape (such as fiber-reinforced packing tape) along the leading edge for durability.
Step 3: Building the Fuselage
🔹 Cut the fuselage from a single piece of 2.5cm thick foam (or laminate thinner layers).
🔹 Reinforce the nose with extra foam or light plywood to prevent impact damage.
🔹 Cut slots for the stabilizers, ensuring a tight fit before gluing.
Step 4: Balancing & Adding Nose Weight
🔹 Center of Gravity (CG) should be about ⅓ of the way back from the wing’s leading edge.
🔹 If the glider is too tail-heavy, add weight to the nose (small metal washers or lead pieces).
🔹 If the glider dives too fast, reduce nose weight slightly.
Step 5: Test Flights & Adjustments
🔹 Choose a calm, open space with minimal wind for testing.
🔹 Hold the glider level and throw it forward with a smooth motion.
🔹 Observe the flight:
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Dives down too quickly? Remove some nose weight.
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Nose up and stalls? Add a little weight to the nose.
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Turns left or right? Adjust the tail fin slightly or sand wing edges for symmetry.
Step 6: Launching Techniques
Hand Launch
✔ Hold the fuselage lightly and throw it forward with a smooth, even push.
✔ Adjust launch angle (~10°–15° up) for best glide performance.
Tow Line Launch (For Longer Flights)
✔ Attach a small hook under the fuselage for a bungee or tow-line launch.
✔ Use a thin fishing line or rubber band to tow the glider into the air.
✔ Release at peak height for a slow, controlled descent.
✅ Your Large XPS Foam Glider is Ready to Fly!
This larger glider is great for long glides, easy modifications, and potential RC conversion