Cánh Hydrofoil Pump Wing (1400cm2)

3D-printed core for a medium/high AR front wing 1400cm2. Optimal for pump foiling or efoil cruising. It uses a NACA 4412 profile. The design is optimized as a core, so that after lamination the shape is optimal for hydrodynamics. 

This is the reinforcement layup I used, carbon fiber will create a stringer and stiffener wing. Fiberglass is much cheaper and would probably be just fine with the same layup. If you are a heavier rider (+90kg) you might want to use more UNI reinforcement. 

• 2 x 200g UNI

• 1 x 300g Biax

• 1 x 200g Twill

• 1 x 100g Twill (Glass) 

Total GSM: 1000g per m2

• 1° AOT

• Wingspan of 920mm

• aspect ratio of 4.6

• 190mm span

• ~3° washout at the tip

• NACA 4412

• 3xm6 mounting holes, 

Instructions

1. Mount the four parts of the wing together with glue and 4 mm pins.

2. Fill the 3 holes for the fuselage with epoxy.

3. Sand the entire wing with low grit sandpaper.

4. Laminate with fiberglass or carbon fiber.  When cutting out the reinforcements make every layer slightly offset. If all the pieces are the exact same size and stacked on top op each other, there will be ridges in the skin. Do not try to wrap the reinforcement layer around the leading (front) edge, only wrap the outermost layers. Same process for both sides.

5. The trailing edge is trimmed to allow for a solid epoxy/carbon trailing edge. The first lamination (blue) should create a "step" that can be sanded flush with the opposite side. Then when laminating the second side (yellow) it will have a flat surface. The epoxy/carbon part should be 4 mm thick along the entire span of the wing.

6. Now you can sand everything, the outer most fiberglass layer creates a buffer you can sand into, you don't want to sand into the carbon, since it will affect both strength and appearance. 

7. You can put on a final layer of lamination or coating epoxy, or alternatively paint the wing.