Front wing building.
After reading many online methods of quick solutions of how to produce wings I took a step back. I looked into the different hydrofoil profiles being regularly used an soon discovered that any profile will work. As a "newbie" not fully understanding what is good and bad, l took a stab in the dark and started drawing a front wing.
I was going to use the eppler 817 but was a little concerned with the reflex, and how successfully I could mould it. So instead I used an airfoil profile Aquila 9.3% which would be a whole lot easier. I decided on a size of 58cm^2 and added anhedral and tapered the front leading edge. I finally committed to a wing shape and created a 3d model.
The issue I have is what ever you draw, trying to produce an accurate wing which is symmetric in all respects is impossible. Even creating a mould on a cnc router or machining center is difficult unless you have 3 axis interpolation. So I designed a curved jig which I could build my plug on. What I did was slice my 3d profile up every 15mm from the center. So I produced multiple 2d profiles right to the wing tips. I laser cut these profiles out of 1mm steel, which I positioned on my jig in exactly correct position and angle. I epoxyed them in place. By using a jig I had an xyz datum and knew exactly the position of each piece. The final result ended up looking like a aeroplane wing waiting for a membrane.
You might ask why I did this. My reasoning for using a thin steel ribs was that my profile was correct in all respects. The steel ribs every 15mm controlled the final profile. I basically filled the skeleton with bog fairing as close as possible to the ribs. Finally I sanded the top of the wing down to the ribs until I hit steel.
When the sanding was completed I laid some carbon fiber on top to strengthen my wing. I could now remove from the jig
- Front wing with 150gsm of twill wet laminated on top side
You can see some of the ribs under the carbon. A little sanding with A Foam block and spot filling would smooth out these. The under side was easy as it was flat. So no laminate required
I started my rear wing next knowing exactly what to do, using eppler 817 and doing a much better job. The rear wing needed laminating top and bottom. I used some light glass for this
- 2 wings ready to paint with primer
So I ended up with my 2 wings which I new were exactly correct to the profiles I choose.
After priming, wet sanding and polishing l produced my wings ready to mould.
- Front wing primed