DIY Home Made wooden Hydrofoil fins

[Hawaiis]

I believe wood is cheaper and easier for DIYer to make a beginner hydrofoil.
It will not win races against high end composite foils, but performance wise is comparable to most commercially available beginner foils. Rigidity is the problem I have with wood. If I can make it rigid, I will be able to use thinner wood and more performance. The joints are very critical to make the foil rigid. The biggest problem I face is the connection between the strut and fuselage. It is the weakest point on my wood foil. I am still looking at making the joint stronger.

[windfreak74]

for the fuselaje/strut connections i use 2 layers of fiberglass to make the connection stronger.
the fiberglass layers between the 3 layers of Wood take the torsión forces and prevents it from splitiing.

[ahmthai]

Got to go again and i cant figure out the standing position on the foil.
I think that im positioning my back foot behind the mast and i always bob up and down!
well i have all easter weekend for riding so ill keep trying.

Ive recentry got my new carbón and fiberglass fabrics for my V2 foil
im thinking of building a Wood core mast (eppler 837) of 17 or 19mm thickness with (120 mmchord)

this is my programmed layup for a 19MM mast

1 layer 15 oz triaxial carbón 12k 0/60/60(1mm)
1 layer 6oz 0/90 carbón plain weave(0,25MM)
1 layer of 15 ozz Fiberglass +-45° (1mm)
1 layer of 15 oz Fiberglass +-45° (1mm)
1 layer of 15oz Fiberglass +-45° (1mm)
10mm bamboo core
1 layer of 15 ozz Fiberglass +-45° (1mm)
1 layer of 15 oz Fiberglass +-45° (1mm)
1 layer of 15oz Fiberglass +-45° (1mm)
1 layer 6oz 0/90 carbón plain weave(0,25MM)
1 layer 15 oz triaxial carbón 12k 0/60/60(1mm)
with this layup i will get an aproximate composite skin of 3 to 4mm on each side of the core.

i can take away one layer of 1 layer of 15 oz Fiberglass +-45° (1mm) on each side to get a 17MM profile.
Do you guys think is overkill?

That layup looks like way overkill with a relatively stiff/strong bamboo core. I would think about 500g (~18 oz) of carbon on each side would be sufficient. Use uni-direction for longitudinal stiffness and biax to control twist. Using more layers of lighter cloth will be stronger than fewer heavier ones. I don't think you need any glass as it is heavier and less stiff than carbon.

[Hawaiis]

Just finished the G10 Fiberglass wings, first test tomorrow.

[windfreak74]

Hello hawaiis ,
good profiling! did you do it with a grinder?
whats the shape and size?
please post more pics?

[Hawaiis]

1/4 inch thick G10 fiberglass, 5"X21" front Wing, 3"X12" rear wing. Profiled with router and table saw.

[Hawaiis]

Problem with flat plate wing is the lack of diehedral.
I added two twin tip fins to make the wind tips.

[Bille]

Problem with flat plate wing is the lack of diehedral.
I added two twin tip fins to make the wind tips.

I put those things on All my RC acrobatic airplanes ; also had them on the
HG that i competed with in comps. They add Lots of stability, but it's at
the expense of a bit of drag, (no Biggie , for the return).

On the glider, there is a Huge difference in performance , if there placed
on top of the wing-tip or placed on the bottom. It looks like you have the
option to go top or bottom (?) ; maybe you could do that on back to back
sessions, and post the difference between the two ? I'd be very interested
in that !!

Thanks : Bille

[Hawaiis]

Bille:
I tried the test on titanium before and the results are astonishing on high aspect front wings.
Less difference on low aspect wings. The front wing tips need to point down and rear wing tips point up.

[Hawaiis]

20140624
Front wing 10mm Bamboo
Rear Wing 2.2mm Titanium 6Al 6V 2Sn
Strut carbon fiber covered Koa Wood
Board 2008 Carafino
Kite 2013 Ozone Edge 17M
Wind 6-8 knots
Music Song of Puyuma by Samingad