I made this fin foil in the hope of creating more lift to get by big ass planning earlier in that 10 to 13 kt range.
It is 34 cm wide on a 60cm long fin and will be used on a 90cm wide board.
I can adjust the angle of the wing a little and it is now parallel with the bottom of the board.
My thinking is that when trying to get up to plane and the front of the board is up it will create lift and when the board flattens out planning it should not have that much drag.
Enter laughing now
Will it work ? ,probably not.
Will it create more drag than its worth ?
Should I wear a helmet ?
Please leave prediction feedback before I try
The winner gets an Elephant stamp






Parts for my creation ( lightening and thunder in background with devious laughter )








Fifteen hours later...

It lives.

That is a bloody work of art.

love it ...
in terms of angle - make it parallel to the board ??

Looks excellent. Love the metal work. So do you have a bigger distance on the top of the horizontal foil, i.e. like a plane wing. Also I was thinking with the holes for mounting the wing are you going to plug them with wax for example to reduce turbulence?

^^^ dunno -it is a symmetrical foil so needs angle of attack to generate lift. As the board gets faster and nose drops the AOA will decrease (and thereby lift) so it could work very nicely

(which makes me realise its upside down? But I am on beer #3)

EDIT - was replying to JW's post.....

You better patent that in case it does work

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Dean 424 said..
Looks excellent. Love the metal work. So do you have a bigger distance on the top of the horizontal foil, i.e. like a plane wing. Also I was thinking with the holes for mounting the wing are you going to plug them with wax for example to reduce turbulence?

Good idea plugging the holes.
I can't modify this wing it's hollow with foam.
I made the mount so I could try different foils.
Mabee a thinner , wider boomerang shape ? Mk 2,3 ?
Im worried that if I do get up to a lot of speed it may start planing on the foil , and then crash horribly

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bigbear said..
You better patent that in case it does work

+1

Imax 1 I really hope it works mate!

Is that your lathe and milling machine in the background? You in a workshop or the home garage?

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Mark _australia said..
^^^ dunno -it is a symmetrical foil so needs angle of attack to generate lift. As the board gets faster and nose drops the AOA will decrease (and thereby lift) so it could work very nicely

(which makes me realise its upside down? But I am on beer #3)

EDIT - was replying to JW's post.....

The upside down thing got me thinking . It would be better the pressure pushing on the mount instead of pulling on the screws , I'll turn the mount over.
And while I'm at it I'll put a thin plate under the screw heads. Could be a lot of force going on here.

Very nice looking job!!!
You should be able to control lift with front-back foot pressure changing the angle of attack.
Depending where you back strap is, The lift is probably going to be behind you, so as the foil lifts up it should push the nose down, decreasing angle of attack and reducing up wards lift.
But be very careful shifting weight radically forward or back until you work out how the foil behaves

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Is that your lathe and milling machine in the background? You in a workshop or the home garage?

I have a little maintainance workshop at the back of my buisiness.
I love to tinker .

Awesome job!
Buy a helmet.

Have you got a GoPro?

Very nice construction. Waiting to hear review.
the angle of the wing addition, is the critical part, if it's not correct then it won't create lift it will create downforce of sorts. Wish I understood all that , but I don't. So not saying it's wrong or correct. But very nice stuff.

any weeds will be a factor

this I felt worked nicely but it's A BIC WindSup, or nothing wrong and perhaps a small gain of upwind /speed..perhaps
the wing addition was shaped after a WWII SPITFIRE.

The position relative to the existing fin tip, I feel you have it dead on, too close to the tip it's in danger of aground contact.

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Hey Imax1, yet another great idea from your Creation Station! Custom Weed fin, Vgrip booms now Foiling fins , all in the last 6months. Sailboarding isnt just a hobby, its a way of life!! Awesome

Nice work. You seem to have it well thought out. Smaller foil may be needed when going fast. Drilling 3 holes through mid span of main foil basically at max load point (1/4 chord) may require reinforcing of main foil. Those drake foils were of variable construction. Early ones lots of strength, latter one not much.
Edit...In the category of nothing new under the sun. Googling after seeing your nice work I came across this. Google translation of Dutch site, judging by material (plastic) this is a '80s version of the same idea.
translate.google.com/translate?act=url&depth=1&hl=en&ie=UTF8&prev=_t&rurl=translate.google.com&sl=auto&sp=nmt4&tl=en&u=http://windsurfing.rdeleeuw.nl/diverse/draagvleugel/


I can see the Man Mob (mike , Pepe, Alby & Fangy etc) all having a tinker on this idea over the winter. :-)

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yoyo said..
Nice work. You seem to have it well thought out. Smaller foil may be needed when going fast. Drilling 3 holes through mid span of main foil basically at max load point (1/4 chord) may require reinforcing of main foil. Those drake foils were of variable construction. Early ones lots of strength, latter one not much.

This idea is only for marginal winds , when its over 13kts im happy with a normal fin.
I would think it is the older stronger one . It weighs a ton , has no flex whatsoever and is solid unlike the shallow water fin that i modified which has a foam core.
Doesn't mean i wont break it.
What worries me is when i get airborne ( well the landing actually ).
I hope the fin doesn't grab and slam the front of the board down and me with it .
Mabee ill test without harness lines.
Any local test pilots without family ???

Done some testing today
Suprised , very happy.
Conditions , freshwater , flat , gusty 8 to 18 kts ,
Board , Starboard Go 170 litre , 90 wide ,7.8 North Ram. ( could have gone bigger but I wanted half planing )
Started with 60 cm fin , my best combo for early planing.
My mates egged me on to try my winged Frankenstein , put on helmet.
It worked good.
Got planing earlier and could plane slower.
No problem at all going fast ( like it wasn't there )
It felt like the board sat higher when going .
It didn't do anything strange. ( but I didn't get it airborne )
Turned the same ( slowly it is 90 wide )
Upwind same.
But not perfect ,
As the board lifted just as your going for the straps it feels a little draggy until it levels off.
Starting is a bit different , I found hanging off the back to get the nose up worked best.It didn't round up into the wind like it normally would have doing this.
I didn't do any adjustments.
I think I could slide the base back.
Even though it's not perfect , it's quite good. It is my best light wind option by far.
So it did exactly what I wanted ( what an ass ).
Now ill play with angle of attack and mast base .
If I could just get rid of that draggy feeling when getting in the straps.........

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Imax1 said..
>>>
If I could just get rid of that draggy feeling when getting in the straps.........

Great result!!!!!!!!

So as you go for the straps does the nose lift??

Too much angle of attack will surely cause more drag.
If this is the case, maybe more weight on the boom to keep the nose down as you shift your feet, just a slight change in technique.

If it's the opposite and the nose dips, you're loosing the fin lift and increasing the wetted area.
maybe you have too much weight on the boom as you take the weight off your feet to move them into the straps.

Moving mast track back could help here.

But if the trim is perfect while sailing, changing things will probably spoil that.

So if I was on the board, I'd be gradually shifting my weight back to see if I could make it fly, But very carefully, and certainly not in choppy conditions.

Nice Work Imax!

Specially in freshwater too!

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decrepit said..

Imax1 said..
>>>
If I could just get rid of that draggy feeling when getting in the straps.........

Great result!!!!!!!!

So as you go for the straps does the nose lift??

Too much angle of attack will surely cause more drag.
If this is the case, maybe more weight on the boom to keep the nose down as you shift your feet, just a slight change in technique.

If it's the opposite and the nose dips, you're loosing the fin lift and increasing the wetted area.
maybe you have too much weight on the boom as you take the weight off your feet to move them into the straps.

Moving mast track back could help here.

But if the trim is perfect while sailing, changing things will probably spoil that.

So if I was on the board, I'd be gradually shifting my weight back to see if I could make it fly, But very carefully, and certainly not in choppy conditions.

Actually the board angle seems perfect.
I think it may be the extra leading edge cutting through the water , 60 for the fin and another 34 for the foil , that's like a 94cm fin ! And add the mount drag.
When planing the drag goes away so I would presume I'm getting enough lift slipperiness to counteract the drag.
I wasn't going crazy fast just nicely in the gusts. About the same speed as without the foil.
Another thing I noticed ( being gusty showed this ) when the wind suddenly dropped right off , the board slowed quickly , it didn't get that little coast before bogging down. However if I had a little wind it kept going nicely and could keep planing in slo,mo . ( strange feeling like I was half my weight )
One thing I can say is that a foil on a fin is a great thing. If I can make such a big difference and I have no idea on what I'm doing , imagine proper foils made by people who do know what there doing. I just fluked it.
So I'll try angle changes to see what happens.
Im limited with what I got.
This is an area of sailing that has to be looked into.
That Virus Fins on the other forum ( alternative to foiling) could just be awesome ???
Thats what got my idea going , but I didn't want to foil just more lift.

Zulufins coming soon

IMax1

no lightning visible, nor thunder, nor devious laughter.

the wing addition, what shape did you use..ssymmetrical on both sides, normal curve of the donor fin, then match the other side ? The angle you mounted seems fairly parallel to the fin base (the real fin ) so as someone else asked , is it parallel to the board bottom ?

The trailing edge of the wing .. thinking that with the correct , sweep? May improve it

without any "expert" opinion, guidance , I would probably make the wing with both sides the same and put the trailing side pointed in the middle . So when mounted if it ain't right, then it ain't right on both sides.
i kinda think that a asymmetrical shape , with a relatively flat bottom, may be a option to my above sentence.

while the bolt on mount looks techy, I think too much flow is disrupted with it. Epoxy , glass, would be more effective, with little likelihood of hitting the wing on the bottom.

you have spurred my interest in carrying on with a fin..if only I didn't have 9 million projects already

forceten,
The wing addition is symmetrical , ( not like a plane wing ),
It is the same on both sides,
It is parallel with the bottom of the board , ( i can adjust the wing angle by putting packers between the wing and mount ).
It would be heaps better smoothly glassed onto the main fin but I made the mount so that i can try different wings and angles.
When i finish testing ( wing angle , mast , technique , salt water ) and get the best result i will smooth out the whole area with wax ( thanks Dean 424 ) to get it as slippery as possible. Easy to remove and try another wing.

Go with your project , the more variants and feedback can only be good for us in this promising area of development.

Imax 1, you've got me at it now!!! 70cm fin & a 44cm wing for my SB formula 161. Just need to bang up an alloy mount to attach them both together, probably the hardest part!

Good stuff
For a start set the wing parallel with the bottom of the board .
Good luck and enjoy slo-mo sailing.

There is a company in Poland working on something similar.
Looks interesting

They're Facebook page is;
Thevirus.

Been raining this weekend in the UK so been busy finishing the test dummy MK1 (not a work of art). Iv'e used alloy U profile to slot the wing in place. The rear hole is sausage shaped so I can easily loosen the bolts and tilt the wing to adjust. Iv'e opted to mount the wing 25% down from top, I didn't want it to low. Fin is 70cm and wing is 43cm, will use on a formula board. The pictures are self explanatory. Just need some light winds to try out!!!

Awesome !
Love to know how it works compared to mine.
I still haven't tried different angles yet.

I love this, its almost like everyones turned into crack pot inventors......ever seen the film. " Magnificent men and their flying machines " ???????

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Madge said..
I love this, its almost like everyones turned into crack pot inventors......ever seen the film. " Magnificent men and their flying machines " ???????

When I say " Crack pot " its nothing to do with the drugs Crack or pot....