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  1. #15
    Senior Member
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    Apr 2005
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    Foil pumping after a boost speed to initiate lift.


  2. #16
    Junior Member
    Join Date
    Jan 2018
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    6
    Quote Originally Posted by boards_ronnie View Post
    LOkEfoil LK1 1200 sq cm.
    Something is wrong with this .12 sq.m. flying at 2.5 m/s wind.
    Lift = 0.5* Cy*Wing are * water density * speed^2 = 0.5 *0.8*.12*1000*2.5*2.5=300N=30kg
    The combined weight of the system (human + board + sail + foil) has to be 30 kg.
    If to take realistic weight of the system of 100 kg the board speed has to be not 5 but 8 knots. But, it may be possible that this board actually does at speed of 8 knots while wind is 5 knots, If so, the board has to go upwind. It is impossible to go downwind faster than wind speed. Perhaps, on a tall mast hydrofoil one can pump it up and get on speed with help of light wind continue pumping a little so you doe not even notice pumping and make turns using the altitude. This will probably evolve into mostly pumping foiling with aid of sail. It is like one guy pumped a foil board for 40 miles with aid of waves.
    Hydrofoils are very efficient and can generate much lift at very low speed. One German inventor simply walked on water using 3 meter long foils.
    If to compare speed I have seen a very slow and nice flying foiler with 9 m kite at about 8 knots wind while a faster slalom windsurfer with foil/fin passing next to the kite foiler.

  3. #17
    Senior Member Sailrepair's Avatar
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    Feb 2010
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    Helensburgh
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    1,676
    Regarding early flying - it is indeed a minefield of often contradictory information. I would try and summarize it as follows -

    There are quite a few large winged foils that tend to be on shorter masts and they fly early but are not the quickest and lack range. Then there are the more performance foils with longer masts but they require a bigger sail to get them going.

    The thing is at the bottom end of foiling the differences are very small, there is a fine line between there being enough wind to pump the sail against and there just not being enough energy in the wind to be able to fly.

    Instead of debating whether a foil will fly in 6 or is it 7 kts of wind you can view it in terms of board speed. You can view it as being able to fly as long as you can get the board/foil going along at about 6 kts, then it will lift and fly.

    I don't think lighter people foil that much earlier than heavy guys because they quickly come up against the fact that 4kts if wind speed just doesn't have the required power to get and keep a foil flying.

  4. #18
    Super Moderator
    Join Date
    Apr 2004
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    706
    Zakgear

    Are you, by any chance, the Zakgear who is currently selling the Fly Fin on eBay.com

    https://www.ebay.com/itm/Windsurfing...-/292408896879

    If so, we would appreciate it if you could make your commercial interest clear.

  5. #19
    Junior Member
    Join Date
    Jan 2018
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    6
    I am zakgear.com
    I am sure 60% of people on this forum drive cars with my design in it.

    And you are...? What do you do for money?
    Last edited by zakgear; 18th January 2018 at 07:54 PM. Reason: clarification for Martin, J

  6. #20
    Quote Originally Posted by zakgear View Post
    I am zakgear.com
    I am sure 60% of people on this forum drive cars with my design in it.

    And you are...? What do you do for money?
    Why not just answer "yes" to the question? It's no big deal that you are the one selling the fins.

  7. #21
    Junior Member
    Join Date
    Jan 2018
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    6
    Quote Originally Posted by FightingFools View Post
    Why not just answer "yes" to the question? It's no big deal that you are the one selling the fins.
    I think I came to this forum as zakgear to easy identify me.
    I just searched “zakgear” on Google. Yes, the entire first page results my zakgear work. Second page starts showing other zakgears. Google image search shows my work as much as you can scroll. How did you find zakgear on eBay?
    While giving a credit to this forum, if I may notice that in some cultures it may be considered unethical for the forum owner to research on the participants in intention to publish identities. But I have never lived in UK so it is your way to govern this.
    I apologize for interrupting this interesting discussion. Have fun. Zakgear.com
    Last edited by zakgear; 18th January 2018 at 08:53 PM. Reason: grammer

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