Hey guys, Im building (a prototype for now) custom fully seal welded aluminium hydrofoil. it's going to have similar performance to the LF foil (with simular surface area wings ect..) if it all works out i will also make smaller more efficient wings (with maybe the option of carbon wings even..) Im hoping to make this available for a very affordable/competitive price. PM me if you may be interested.. I will try get things moving in the next couple of weeks or so due to a current injury..

current progress. this is all just balancing in place un welded. but i'm hoping to make some progress on it in the next week or so..

How many hydrofoils have you made in the past?
How much hydrofoil riding experience do you have?

i have intermediate experience in foiling and plenty of experience in kiting in general. this will be my first foil build. i also have almost 10 years of welding and fabricating experience and all the equipment and technology that is needed.. this isn't going to look like a back yard job when it's complete, it will be built to a very high standard. please tell me how you advance to the next line in this forum like you've done it drives me crazy !

Cool.

I don't want to bag on your idea. Its an awesome idea.

I guess my advise is to build it. Ride it tweek it. You may need to test different wing profiles and shapes etc. Theres a ton of info and ideas on kiteforum.com about building foils.

Then once its working as good or better than your LF foil then offer it up to others.

PS Not sure what you mean by advancing to the next line in the forum?

yeh i have got a few prototype wings ready to roll and ill be testing them out asap, it shouldn't take long plus being aluminium i can just about tweak the lift angle on the beach with the right tooling.. p.s i mean going down a line in the message when i press shift/enter (return) it drops a line as im typing but when i hit "post" it all stays on the same line..

I just press enter.
Maybe try a different browser?

How much are you planning to sell that for? Are you really considering the aluminium wings?

price is still un confirmed. I'm still yet to find out how much labour is involved then i'll add up the costs and see.. I'm trying to make it much more affordable than any of the big brands.. and at the moment its looking like its going to be. I'm hoping to make an aluminium wing as well as a carbon wing which will be the more expensive option. i don't see any issue with aluminium wings though..

some progress on the front fin.. (machining to exact thickness.)

You can also make foils out of G10, Wood..Right now nothing but carbon will go fast and have the ultimate flight sensation. We did a lot of testing including 3 prototypes in alloy with combination of G10 wings, carbon wings and metal wings where carbon wings worked best then g10 then metal. Never any faster than 23knots tho plus the issues that arose so we decided not to produce them. Metal foils are heavy and draggy and we had issues with alloy bending on impact like running into ground..But hey the amazing thing is pretty much anything works with general design principles applied.

weighing in at 2.66kg is the...

Lighter than expected! good good. You might be able to apply the following tests to get an idea if stiff enough.

Also there's a vid on kiteforum they fall 'simple stiffness test' and it's basically fully assembled on a board, turn upside down, grab wings and wobble side to side and front to back. Play is bad, stiff is good.

kitefoil.forumactif.org/t1580-mesures-comparatives-de-flex-et-torsion-du-mat

thanks mate.

There is something manly about a milling machine milling stuff! Cool.

HI mate on top of what I have said privately I think making the surface area of front wing attachment a bit bigger would be good. You could attach some square tube 1/4 the size of the fuselage section either side of the centre for the length of the wing.
Putting a 45 deg angle on all square rude sections front and back will also help reduce some turbulence.
When is the first ride ?

Also whilst I am having a look you will need an angle of attack, Bow down on the back wing. about 2-3 degrees would be a good start.
Its also up for debate as to weather you want the back wing on top or bottom of fuselage.
You look like you have some good machines there so you could make up some different shims at 2,3,4 deg angle. This will help keep good surface area on the mount for back wing as opposed to putting washers under there which is common and makes back wing wobble.

I am into this now!
I recon bend tips down on front wing to about 20/30 deg and back tips up the same amount.
start bend about 3/4 of the way to the wing tip
This will help with control

Very good job Adam
Don't waste time getting everything perfect now. Just go riding and see what works and what breaks.
Where s your mast from?
Let us know how you go.

thanks mate, yeh this is just a rough prototype but im a bit fussy with my work..we had it out in the water on the week end and it rode very well ! there was a couple of bolts which were sticking out slightly (not yet counter sunk) so there was a bit of vibration but that is now fixed.. ill be taking it out again for another test ride through out the week hopefully if there is any wind..

haha your starting to get into it now hey ?.. i've got all the machinery available so ill see what i can do.. ill add some of this advice to prototype #2

first test ride on the week end went reasonably well. we bolted the foil onto the LF fish foil board for the test run, but ill be making mounting plates as per requests to suit what ever bolt pattern you like. (also wing aspect ratios and profiles can be made custom or as per standard)

Hi Adam, great work so far :-) I love what you are doing and am about to embark on the same journey. I have had no experience with kite foils but I have built a few yacht rudders and fins in the past. I can't see the exact profile of the wings but I am interested that you have used a short wide flat wing as opposed to a narrower long foil shaped wing. All the research that I have ever done tells me that any flat surface has huge resistance and turbulence in the water. Sail-boats use a NACA0012 foil shape (like the mast). Am I missing something?

upload.wikimedia.org/wikipedia/commons/c/c4/NACA_0012_Demo.svg

Hi Simon,

My 2 cents worth, there appears to be 2 types of kite foil wing.

Liquid force, Fastafoil, Moses, Carafino (dead), and some others all went with the D shape (Delta wing).

Most of the rest have gone with a wing shape with a naca or other profile, some flat from tip to tip, some with wing tips turned up or down. Most common seems to be main wings turned down at tips and stabiliser wings turned up at tips. I guess this is to keep the main wing tips further in the water when heeled over.

Deltas appear to be slower, more forgiving, less likely to hurt you, arguably easier to make & possibly better for waves/foam/etc..
Cost is a lot of speed and drag.

Adam, well done getting it to the point of getting out on the water! Looks very like a store bought LF just with metal wings.

I'm interested to see what sort of figure you come to when you add up time, materials, and a little profit to make it worth your while!

Also for proto 2 have a test to see if it needs a fin for Yaw stabilising (L-R when riding flat) as I think some of the LF guys were adding them. Some bolt straight thru from stabiliser wing thru fuselage to standard twin tip fin underneath - just need to space holes right.

Select to expand quote

kiteboy dave said..
Hi Simon,

My 2 cents worth, there appears to be 2 types of kite foil wing.

Liquid force, Fastafoil, Moses, Carafino (dead), and some others all went with the D shape (Delta wing).

Most of the rest have gone with a wing shape with a naca or other profile, some flat from tip to tip, some with wing tips turned up or down. Most common seems to be main wings turned down at tips and stabiliser wings turned up at tips. I guess this is to keep the main wing tips further in the water when heeled over.

Deltas appear to be slower, more forgiving, less likely to hurt you, arguably easier to make & possibly better for waves/foam/etc..
Cost is a lot of speed and drag.

I vaguely seem to perhaps recall that may be the tips up and down is about yaw (and roll) stability. As winglets, they'll decrease tip vortices and drag...

Be interesting to see how the bird etc shaped wing planforms work out.

Delta is good for low wing loading and low stall speed for high angle of attack, among other things.

Looking great Adam! How did it ride?

What at sort of cosets are you looking at for it?

all finished and ready to ride on the week end !

ill be letting you all know the price (there will still be a prototype #2) but as of now what i can tell you is it will be no more then $1000.

Hey simon, the foil is a low aspect delta shape to create extra lift at low speeds to allow you to release from the water as soon as possible (very beginner friendly). The more high aspect wings are definitely faster but much less stable at low speeds and are very hard to learn on. i will be making 3 different aspect ratios (beginner, intermediate, and advanced) the advanced will have a very high aspect shape. which will all fit this same fuselage bolt pattern.