High Performance MPX Foil/Self-righting Trimaran-The Test Model

Discussion in 'Multihulls' started by Doug Lord, Dec 28, 2010.

  1. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Fire Arrow Foil System

    ====================

    The foil set up is not dependent on a wing mast and should work on any boat designed for it. If you put it on a boat not designed for it, you may launch yourself to the moon(prematurely). The foil system would definitely be an advantage on most tri's . Generally, you should do what the designer says. I've been trying to interest Gary in this system but he dismisses it with "too many foils" which means he doesn't get it. He's a great guy but never lived a more stubborn great man. If you decide to use the Fire Arrow system anyway you should have an engineer look at the plans. Eric Sponberg(if hes not sailing) will help on a per hour basis.
    Good Luck whichever way you go!
     
  2. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    RC Sailboat Development-Spinnakers, Multihulls and Foilers

    These boats were designed, built and produced 15-to 20 years ago. The original video was posted here in a couple of places but was accidentally deleted from youtube a few days ago. None of these designs are being produced now but I hope that they can inspire others.
    The foiler shown here was designed and 6 were built around 2000-the others from 1995-2003. The F3 was the first production rc foiler anywhere. It could tack and gybe on foils and would fly in a 5 mph breeze.
    The spinnaker systems-both asymmetric and symmetric- were the first of their kind -being fully gybable on demand and fully retractable in a couple of seconds.
    The non-foiling trimaran shown was one of two bought by Dr. Sam Bradfield and later equipped with foils as a test model for his 40' Skat.

    https://www.youtube.com/watch?v=_Nx8vPmL9YM


    ======================
    Dr. Bradfields modified Flyer^3 tri-sistership to the one in the video. Dr. Sam added hydrofoils:
     

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  3. Doug Lord
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

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  4. Doug Lord
    Joined: May 2009
    Posts: 16,679
    Likes: 349, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Fire Arrow Foiler / MPX Foil System Testing and Development-Two Stage Ama

    This is an update on the concept of a Two Stage Ama:
    --
    A while back I was thinking of a 15' version of the Fire Arrow and was troubled once again by calling such a crucial piece in the ama function and design a "curved piece". Then a light flashed on and I came up with a technically correct name for the ama + the "curved piece" : a "two-stage ama". The reason "two stage ama" works is because the curved piece actually is part of the ama though quite distinct from the ama hull. And in sailing, the buoyancy of the ama hull and of the curved piece affects the RM of the boat in two distinct stages: Stage 1- when the ama hull is immersed the RM is enhanced by the 6lb(about 280lb full size) of buoyancy of the " ama hull", Stage 2- when the "curved piece" is immersed the RM due to the immersion of the ama hull is doubled".
    So from now on this feature of the Fire Arrow will be call a Two Stage Ama(TSA or 2S ama). Interestingly, in the testing done so far even in the overpowered conditions of the second video the second stage of the ama(the curved piece) has not been submerged. This hasn't been tested yet but ,theoretically, the high dihedral crossarms coupled with the Two Stage Ama(TSA) should allow self-righting from at least 90 degrees(if it ever gets that far).
    The 2nd stage of the ama(curved piece) is designed with about the same buoyancy as stage 1(the hull) and together they create fairly high static RM coupled with the over square beam and high dihedral crossarms. But it is stage 2 that determines the run angle of the planing ama surface and of the ama foil. I even considered making the junction between the two adjustable
    so the ride angle could be adjusted. The foils AOI(angle of incidence) is adjustable but the ride angle of the planing surface is not-at least on the Test Model. It could be adjustable on the full size version w/o a whole lot of trouble.
    But,again, whats really cool about the Fire Arrow concept is that sailing(foiling)- the main and rudder foil working together control the ride angle of the planing surface and the foil! In other words neither can pitch up or down on their own.
    -----
    Clearly, this Two Stage Ama Design offers a lot both Statically and Dynamically:
    1-Statically- the boat is sitting still and hit by a hand of God gust. It is theoretically possible that the boat could be knocked over with the mast horizontal but the two stage ama offers reserve buoyancy after the the ama hull itself is immersed and yet it is not enough to fly the main hull. It is enough, however, to right the boat.
    2-Dynamically-The ama hull has two levels of dynamic vertical force:
    a. first and foremost the ama lifting foil that works from very low speed on up,
    b. Second, and a sort of back up at speed, is the planing hull design of the ama. To start with on the Fire Arrow, the planing surface, only comes into contact with the surface at very low speed with the ama starting to fly before the main hull does. And when the boat is flying the ama performs the same function that the planing ama on Hydroptere does: reserve lift during incidental surface contact at speed.

    click on pictures:
     

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  5. oldsailor7
    Joined: May 2008
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    Location: Sydney Australia

    oldsailor7 Senior Member

    Sounds very logical Doug.
    I guess it all depends on the floatation volume of the "Curved" pieces. :?:
     
  6. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Fire Arrow Foiler / MPX Foil System Testing and --Two Stage Ama

    Paddy, the ama hull(stage 1) and the curved piece(stage 2) are the same volume. So far we've never got more than the hull in the water.
     
  7. oldsailor7
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    Location: Sydney Australia

    oldsailor7 Senior Member

    Sounds like 100% backup. :D
     
  8. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Fire Arrow Foiler / MPX Foil System Testing and Development--Two Stage Ama

    I think it is a good system for this type of boat-especially if it keeps working so well......
     
  9. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Upwind Foiler Performance--Wallying

    Check this out if you think you'll ever race a foiler upwind:
    http://www.virtac.com.au/ Scroll down to parts 1 and 2.
     
  10. Doug Lord
    Joined: May 2009
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    D4Z /AC 55RC--proto for AC 62RC / Rig

    Here are some shots of the nearly complete rig including the new "vanganeck" that allows the main to be about 2" lower than it would be otherwise. Vang is adjusted by moving the pin fore and aft and up or down which cause the boom to pivot. "Wing Tip" has foam buoyancy to prevent a turtle. Main is reefable:
     

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  11. Doug Lord
    Joined: May 2009
    Posts: 16,679
    Likes: 349, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

  12. Doug Lord
    Joined: May 2009
    Posts: 16,679
    Likes: 349, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

  13. Doug Lord
    Joined: May 2009
    Posts: 16,679
    Likes: 349, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Fire C-24' Fire Arrow

    This is just some very rough doodles of a 24' X 24' trimaran with planing main hull and amas as well as the full Fire Arrow MPX foil system. I think it would be fast if it wasn't overloaded but would probably have to be built very carefully to keep all up weight low. Two side cockpits and covered space likely greater than most 24' trimarans.
    It's just an idea with some potential:
     

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    Last edited: Mar 8, 2015
  14. Doug Lord
    Joined: May 2009
    Posts: 16,679
    Likes: 349, Points: 93, Legacy Rep: 1362
    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Fire Arrow Foiler / MPX Foil System Testing and Development

    When the full size version is built it will use up to 4 bucket seats designed to slide fore and aft and then lock. They won't be just any bucket seats-they'll have foam and a carbon frame and look similar to the ones in the picture below but be intensely comfortable.
    The crew on this boat will not need to move to windward so there will be no tramps-at least initially. A souped-up version of the boat may allow the crew to move to windward with a larger rig but the standard 350 sq.ft. main and jib plus a 3-400sq.ft screecher/asy will give the boat plenty of power to foil in a 4-5 knot breeze. And the rig will be reefable.
    I'm hoping that a full size prototype can be built in the not too distant future.
    click--
     

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  15. Doug Lord
    Joined: May 2009
    Posts: 16,679
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    Location: Cocoa, Florida

    Doug Lord Flight Ready

    Fire Arrow Foiler / MPX Foil System Testing and Development--Testing Heads Up!!

    Dan and I have been talking and he is really enthusiastic about getting some video -we might have a week around the 23rd of March. And maybe some time in April but lots of time in May, June and July and we're going to be going for GREAT video mostly of the Fire Arrow but also the D4Z cat.
    I'm ready for this-it's going to be lots of fun(if we find a shady place!).But we're going for simply outstanding video-that is the goal-and we will get it done!
     
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