Page 27 of 35

Re: DIY Home Made wooden Hydrofoil fins

Posted: Mon Jan 27, 2014 2:46 pm
by dlprince69
Here is a picture of my current DIY wooden hydrofoil wing

Core is red oak (Home Depot)

Core root thickness is 7 mm
trailing edge almost paper thin
tips 1 mm
Airfoil shape Eppler 817 with a 50% reduced cord thickness
Core size
Wingspan 500 mm
Cord length at root 150 mm
Cord length at tip 50 mm



4 layers of Home Depot fiber glass on top
5 layers of Home Depot fiberglass on the bottom

Screw holes bored at 1/2 inch and filled with expoy / fiber mix to seal the wood core.

Finished wing has a solid 2 mm fiberglass edge
Wingspan 504 mm
Cord length at root 154 mm
Cord length at tip 54 mm

Much faster than stock MHL front wing. Maybe a little too much flex in the wing. Next version will have a layer of carbon uni top and bottom.

Re: DIY Home Made wooden Hydrofoil fins

Posted: Mon Jan 27, 2014 5:08 pm
by Tone
Image
Image
Image

Some progress here.

carbon fun starts next week.

Re: DIY Home Made wooden Hydrofoil fins

Posted: Mon Jan 27, 2014 8:24 pm
by windfreak74
my front wing is about 800 cm2
2 layers 5oz. fiberglass on top
2 layers 5 0z. fiberglass on bottom
It has 11 mm in the thickest part and 17 cms long
470 mm spam wise

Re: DIY Home Made wooden Hydrofoil fins

Posted: Wed Jan 29, 2014 5:30 pm
by windfreak74
yesterday i ended the vaccum bagging on keel.
50 hours looged.
Pedro

Re: DIY Home Made wooden Hydrofoil fins

Posted: Wed Jan 29, 2014 5:49 pm
by Tone
windfreak74 wrote:yesterday i ended the vaccum bagging on keel.
50 hours looged.
Pedro
Looking good.

how many layers of carbon over the core?

Thanks

Re: DIY Home Made wooden Hydrofoil fins

Posted: Wed Jan 29, 2014 6:08 pm
by windfreak74
i did 1 layer of 6oz. in +-45 °
an will use a layer of 2 oz fiberglass in 0/90 to get a better finish on carbón.

i ended with keel at 24.5mm thick and 138mm long.
the keel will have an effective height from bottom of board to bottom of fuselaje of 870mm.
Cheers,
Pedro

Re: DIY Home Made wooden Hydrofoil fins

Posted: Thu Feb 06, 2014 7:29 pm
by windfreak74
50 hours logged.
i keep going a little slow but im still on it!
vaccum bag did not tur out perfect but i lack the apropriate vaccum bagging supply.
the strut is ready for shaping and vaccum bagging.
Hope to have it done this month.
cheers,
Pedro

Re: DIY Home Made wooden Hydrofoil fins

Posted: Sat Feb 08, 2014 4:23 am
by windfreak74
55 hours logged
final board position pointing up
final front adjustment on front wing
filling with epoxy for fuselaje to strut connetion.
center strut ended being 13 inches from the back of the board.
almost ready for maiden voyage!!

Re: DIY Home Made wooden Hydrofoil fins

Posted: Sat Feb 08, 2014 10:32 am
by Hawaiis
Almost done, can't wait to see how it works.

Re: DIY Home Made wooden Hydrofoil fins

Posted: Sat Feb 08, 2014 2:16 pm
by windfreak74
with 24.5 chord thickness i made the 3 point stress test on the keel after the final layup.
With 75 kilos in the midlle of the keel it deflected 3mm.
weight is 2.2 kilos at 24.5mm x 142mm x 870mm
i think is stiff as necesary.
what do you guys think?
ill start on a new keel with a thinner chord (16mm) and longer mast (920mm).
the idea is to make upper half in 24mm ans the lower half that goes inthe wáter tapered down to 16mm.
that way ill get both stiff and thinner and faster keel. :thumb: