Monohull Speed: Speed Dream by Vlad Murnikov

Discussion in 'Sailboats' started by Doug Lord, Jan 8, 2010.

  1. TINHO DORNELLAS
    Joined: Dec 2010
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    Location: Merritt Island

    TINHO DORNELLAS Junior Member

    Hi Paul,
    Thanks for the welcome.
    I designed the Ahd Zen. Jean Bouldoires shaped the original prototype and we modified it in south France prior to approval. Jean was the shaper of many of World Champion Antoine Albeau's boards, and responsible for most of the legendary AHD models you know of. As we argued my design details on this project, and eventually produced the board, I developed even more respect for those who quietly put ideas into 3D forms. Jean left AHD and later shaped the new Olympic board, the RSX.
    I just finished a custom "mini zen" for a long time big boy customer and will be posting the pictures as soon as it is painted.
     
  2. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    ================
    Tinho, I posted this in the other thread right after our conversation:

    "Tinho, great to see your post. To the extent I misquoted you at any time I apologize. You have been a great help to me in listening to my ideas and most recently helping me with the MPX-12 planing ama. I appreciate your help and advice. I'm sorry that my own personal stalker involved you in this manner.
    Thanks for your generous comments just now on the phone!"
    Doug
    ==============================================================
    ==============================================================

    PS- I 100% believed that you were a World Champion but since you and I don't discuss that stuff I don't know where it came from. I also 100% believed that you had told me about the windsurfer rig being vertical, raked back and the board flat. I talk to a lot of people and some how that came to be "fact". I apologise again and will make sure the next time I reference anything about you that I run it by you first. It bugs the hell out of me that you got dragged into this by a stalker and yet ,in reality, its probably good to get the facts that I screwed up straightened out.
    And I hope that, as time permits, you will participate on boatdesign-you have a lot to offer and your involvement with this community would help us all.
     
  3. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    =====================
    Paul, thanks for the link-there is more here: http://foils.wordpress.com/
    There is a big difference between these foils and the old air-chair foils by Rush Randall on his original windsurfer foiler. I think there is tremendous potential for development of a windsurfer foiler that is fast and fun.....



    also see Manuel's video here: http://www.boatdesign.net/forums/sailboats/foiling-kiteboards-vs-normal-kiteboards-35108-2.html

    click on image:
     

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  4. cardsinplay
    Joined: Oct 2010
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    Location: Camp Plasma

    cardsinplay da Vinci Group


    It's truly sad when someone can't speak to truth on a matter and others interested in the process of truth have to go to the inferred source to verify the comments.

    You spoke incorrectly from a technical perspective and then went well out of school when you referred to Tinho in your self-aggrandizing comments on this thread. Without doubt, you were looking to tag your misguided opinions with his credibility and you got it all so terribly wrong. That is an incredibly low and twisted thing to do to anyone, much less a guy with whom you wish to remain friends. The fact that he found it necessary to come to BD.net and straighten you out is irrefutable evidence that you engaged your keyboard before recognizing the meaning of friendship, much less checking to see if your distorted idea as to how windsurfers actually work, had any basis in fact.

    You were given plenty of time to fix your distorted opinion and were asked to do so twice. You posted additionally to this thread without addressing the issues, so I went to the source and suggested that he was being made the fool on these pages. Tinho's actions and comments in response say it all. If you try to ignore, or deflect, the issue of your responsibility, it tells everyone that you haven't really gotten the lesson here.

    It's simple, Doug... own your baloney and man-up when you get it wrong. Do, at the very least, some degree of homework before you spew about things where you have no substance and DO NOT, under any circumstances, attribute remarks to anyone, (especially someone who is an acknowledged Master in the field) before getting their OK on the matter.
     
  5. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    =========================
    I don't usually respond to this despicable excuse for an individual but I ask your indulgence for the following-a quote of mine from ostlinds other thread:

    "ostlind, you are my own personal stalker and as such are a worthless, poor excuse for a human being. You are unable to intelligently discuss issues and try at every turn to disrupt any thread of which I am a part. You use inuendo ,outright lies and plain BS to create turmoil that you think will affect me, discredit me, hurt me or any thread of which I am a part. You are a disgusting, miserable, lowlife failure.
    ---------------

    Tinho is a friend of mine and will remain so-he is a first class individual and has been a big help to me a number of times as well as being a great source of inspiration."
     
  6. cardsinplay
    Joined: Oct 2010
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    Location: Camp Plasma

    cardsinplay da Vinci Group


    Did somebody force you to write the above quote, Doug? Did I leverage you in some way to spout-off, incorrectly, about fast sailboards and how they operate? Did someone twist your nose until you attributed your bogus comments in a reference to Tinho Dornellas, as if he told you to write that above quote? So, you want to call me a stalker, do you? Geez, is that a fabulous misdirection play, or what? You tell the lies... I bust you doing so and now in your head, I'm the bad guy? Classic prisoner mentality. I suppose that the police are stalkers, the judges are stalkers, your teachers, your Mom, your Dad, neighbors, classmates and any other person who found you slinging untruths and suggested that you deal with it honestly? Paranoia strikes deep, Douglas. The whole world is out to get you.

    I understand that you are spewing right now because you have been cornered in a process that makes you look hideously inadequate in front of your desired peers. You are also playing yourself as a guy who makes things up to suit his position in an argument. I don't have to dig back in any archive to further castigate you, you've done a good enough job of that all by yourself.

    Perhaps if you come clean to everyone here who was participating in the discussion, you might be able to begin with the reconstruction of your presence and credibility. Having suggested, incorrectly, a non-existent statement from a respected individual is not good form. Throwing your glossed-up vitriol at me because I called you out on your fake attribution is also bad form.

    Again... you were given two open opportunities to come clean on the nonsense statement shown in the quote above. That you, instead, chose to ignore the requests says that you knew you had gotten it wrong and were trying to hide out, hoping it would blow away. Well, bukaroo, you can see how effective that strategy turned-out to be. All I had to do was suggest to Tinho that he was being mis-represented as a World Champion and that the statement that was being inferred as coming from him, was casting his reputation in a very bad light. (all of which is a truth for anyone to see in your posted quote and Tinho's subsequent response) Tinho produced his own energy on the matter after that and you were nailed with your hand in the wrong kind of cookie jar.

    If you think that this incident won't color any of Tinho's future dealings with you, my bet is that you are totally wrong. Tinho strikes me as a guy who is pretty darn proud of his accomplishments and has worked hard to construct a windsurf school where clients can trust that he knows of what he speaks. What you just did by grossly misrepresenting him, was to cast that hard work of his in a very bad light. Why else would he hustle to correct any potential damage that you had done?

    Have some class, Doug. If there's someone to whom you should be slinging nasty comments, that guy is living in your clothes. You did this all on your own and for some crazy reason, thought you could get away with it.

    We are all saddened by your less than articulate response, as well as your apparent lack of integrity in the matter. You can change that reality, but I'm not holding my breath as to your glorious epiphany.
     
  7. Cheesy
    Joined: Aug 2008
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    Location: NZ

    Cheesy Senior Member

    Im not exactly sure what you mean by using small body movements to handle huge load variations so I will expand a bit on this as kites are still somewhat of a mystery to most on here. To keep things simple this will be referring to a twin tip board.

    In addition to being able to control (dissipate) power with the board the AOA of the kite is directly controlled. Kites have four (plus or minus depending on safety systems etc) lines, each of these lines is connected in some way to a corner (or virtual corner) of the kite. The two lines closest to the leading edge of the kite join just above the bar, they go through the bar and connect to the riders harness. The two lines closest to the trailing edge do not join and connect to the end of the bar. The bar is free to slide up and down over the front lines. The rider increases the AOA of the kite by pulling the bar towards themselves, therefore increasing the available power, conversely letting the bar out reduces the power.

    Now this brings me to a defining point in kite development; the introduction of bow kites or supported leading edge kites. Up until 2006 the most popular kite for kite surfing was a 'C' kite, these were characterised by having a predominantly straight and close to parallel leading and training edges with the frontal profile forming a rotated 'C' shape with the tips pointing down. Because of the geometry of these kites the range of trim possible from the position of the bar is limited and the rider is overpowered quite regularly. This leads back to rider inputs controlling the power; when a gust hits with a C kite the rider controls the excess power by edging the board harder (more heel) and pointing it in a more windward direction, this dissipates power in two ways, the rider goes in a more windward direction at a slower speed and as the speed drops the apparent wind also drops.

    Now the big change was the introduction of Bow kites, the leading edge has swept tips and the frontal profile is much flatter than a C kite, as a consequence of this there is no longer four corners to attach the control lines to, these are connected to a bridal (hence the virtual corners mentioned earlier). The geometry of these kites gives a much wider range of AOA (some kites even have a 1:2 pulley system) and as a result the hard edging of boards is not required as much, the bow kites 'sheet' in a very similar way to a skiff main sheet, it is quite easy to feel the almost on/off point with regard to power.
     
  8. P Flados
    Joined: Oct 2010
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    Location: N Carolina

    P Flados Senior Member

    Thanks for the details about the kites. I understand that improving range of control and gust response for kite are both very important. This was not really what I was talking about.

    My discussion was focused on the roll balance (overturning moment vs. righting moment). When a kiter is nearly vertical and his legs are nearly straight, the overturning moment arm (distance from lines to center of effort of the board, measured perpendicular to the lines) is usually just shy of 3 ft. Lets say we have a tall 180 lb kiter with an initial 3 ft moment arm where he has backed off the kite to be pulling only 20 lbs. This is a moment of 60 ft-lbs and his center of gravity (CG) needs to be 60/180 ft (1/3 ft or 4") to the windward of the board center of effort (CE). Now he dials in the kite to 90 lbs of pull. If he were to try to reduce overturning moment by only bending at the knees to reduce the moment arm length, the moment arm would need to be only 60/90 ft (8"). However, instead of just bending at the knees, he also leans more moving his CG to say 1 ft windward of the board. Now the moment arm can be 180/90 or 2 ft. 180 lbs of kite pull can be handled by a CG 1 ft to the windward combined with bending the knees to reduce the overturning moment arm to 1 ft, or any other combination where the two moment arms are equal.

    The above shows that both leaning and bending the knees can be used for roll control when compensating for changes in kite load. The fact the leaning both reduces the overturning moment arm and increases the righting moment arm is part of what give the kites an ability to handle a wide range of kite loads without losing the roll balance game.

    When loads get higher (like Rob, Seb & Alex at Luderitz), the need for leg strength and the need for skill in making the small adjustments to keep thing in balance both go up.
     
  9. Paul Scott
    Joined: Sep 2004
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    Location: San Juan Island, Washington

    Paul Scott Senior Member

    Hard not to think of George Cayley when I see pics of hydrofoils that look like that- 1804!

    http://www.google.com/imgres?imgurl...=T1UNTaCJB4bCsAPn36TuCg&sqi=2&ved=0CCAQ9QEwAQ
     
  10. Cheesy
    Joined: Aug 2008
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    Location: NZ

    Cheesy Senior Member

    I agree with what you have written however in practice the reduction of HM and increase in RM isnt really used as a dynamic form or roll control, thats why I listed some of the other methods of control. The rider will tend to have their body in a relatively static position/angle with regard to the water, with a bow kite sheeting with the bar is the easiest way to control HM. The biggest driver with regard to body position is the ability to absorb chop through your knees while keeping the edge of the board in the water, this is also the limiting factor for speed until you get flat water like Luderitz then us mere mortals would struggle with all sorts of control problems.
     
  11. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Speed Dream

    Cheesy,P Flados- do you forsee the possibility of using kites as the primary power on a boat such as Speed Dream or a similar ocean racer? How would control be addressed? How would you determine kite area as compared to Speed Dreams' SA?
     
  12. CT 249
    Joined: Dec 2004
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    Location: Sydney Australia

    CT 249 Senior Member

  13. RHough
    Joined: Nov 2005
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    Location: BC Summers / Nayarit Winters

    RHough Retro Dude

    None, except that the statement attributed to him was also wrong.
     
  14. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    ----------------------------------------
    I have believed that Tinho was a World Champion for at least 5 years and I firmly believed that the statement I paraphrased was made by him to me. I was wrong and have profusely apologised to Tinho. However, in the post referenced above(post 124) where the statement by me was made I did not use Tinho's name. The name was introduced by my stalker in post 135 where he threatened to e-mail Tinho if I didn't come clean. Since I was absolutely convinced I was right I ignored the stalkers words.
     
    Last edited: Dec 21, 2010

  15. CutOnce

    CutOnce Previous Member

    Can we just let this stuff go?

    It's pretty obvious (and has been all along) what goes on here, and what will continue to go on. This is the Internet. People lie. People misrepresent themselves and information.

    There is no way to reach conclusions or any kind of satisfaction for any one the parties involved. At the end of the day, most people here actually are interested in boat design. I've got my issues with people who confuse fantasy fiction with reality, but this forum does not have the collective will (or moderator concern) to change things.

    Let it go please, everyone. Talk about boats.

    --
    CutOnce
     
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