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

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

  1. daiquiri
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    daiquiri Engineering and Design

    Doug, it is yet another proof that you have to speed up this thing... :p
     
  2. Doug Lord
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    Doug Lord Flight Ready

    MPX Testing and Development---camera department

    Bah Humbug......
    -----------------------
    The GonePro was not for taking pictures of the boat sailing, it was to take pictures of the foils from onboard. Between me and two sailmakers we have several video cameras to catch the boat flying-so no problem there. And one of them has a camera and video transmitter that may work for on board foil video.
     
  3. daiquiri
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    Location: Italy (Garda Lake) and Croatia (Istria)

    daiquiri Engineering and Design

    On the positive side, without the camera you will have a lighter and potentially faster boat. On the negative side... Did you check how will this fact affect the trim and stability?
     
  4. Doug Lord
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    Doug Lord Flight Ready

    MPX Testing and Development------camera department

    =================
    The plan was never to use the gonepro for the first couple of sails onboard so it affects nothing. I wanted to set it up to watch the ama foils and or the
    wand rocker arm and doing that it would be right at the CG. Weight would be insignificant. Down the line I'm going to buy video goggles to use with a video transmitter and DVR to actually sail the boat with the camera. 29 years ago I did something similar with an RC helicopter and this will be quite a bit less of a challenge but about equal in fun value.
     
  5. Doug Lord
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    Doug Lord Flight Ready

    MPX Testing and Development

    The modified port foil is complete and painted. It just needs the red stripe and is ready to go sailing....
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    GoPro--my next door neighbor is a football coach and says that he buys cameras all the time for the team to use and he'll check with the company he buys from to see if they can do anything.
    -----
     

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    Last edited: Jun 7, 2014
  6. Doug Lord
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    Doug Lord Flight Ready

    MPX Testing and Development-------Video Foiling System

    I've just seen Dr. Andrew Masons "VIRTAC" AC simulation video and read about his plans and it is tremendous*. Makes me want to push up my plans mentioned earlier to sail this boat with video goggles with video transmitted from the boat. To do it right may require too much additional weight but thats not for sure. And I definitely wouldn't set this up until I'm satisfied with the boats performance but then I'd go for it-it would be a blast even in a rudimentary form.
    * http://www.boatdesign.net/forums/design-software/virtac-americas-cup-simulator-50597.html#post690958
    Oculus Rift video goggles for total immersion viewing: https://www.kickstarter.com/projects/1523379957/oculus-rift-step-into-the-game
    ============
    When one door shuts(gopro) another opens(Giroptic)! The Giroptic 360 degree camera is the BEST little camera I've ever run across. It would allow the boat to be sailed using just the camera and video transmitter and goggles but with the major advantage of a 360 degree field of view and the ability to look up at the sails or down at the foils-in short the same view you would have if you were a little person about 3" tall standing on the deck of the boat! I will get one of these -it's still under development but I will get one!!!! What a fantastic discovery and I want to thank Dr. Mason for pointing it out to me-simply incredible. Tentative price: $249!!! If I can figure out a way to get this it will change everything.......
    Giroptic 360 degree camera: https://www.kickstarter.com/projects/giroptic/the-worlds-first-full-hd-360-camera

    click--
     

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  7. hoytedow
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    hoytedow Wood Butcher

  8. Doug Lord
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    Doug Lord Flight Ready

    MPX Testing and Development

    Thanks, Hoyt but didn't see anything there that hasn't already been tried. The gopro guy went thru it in detail with me and nothing worked. Maybe my neighbor can find some help or I may let one of my sailmaker friends have a shot at it.
     
  9. Doug Lord
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    Doug Lord Flight Ready

    MPX Test Model-------Foil Comparison----Ama Cat

    These pictures were taken to illustrate the difference between the "old" stb foil and the new port foil. Along the way I discovered a weird looking cat.
    The differences are: 1) "L" portion of port foil is longer with a higher tip, 2) radius between "L" and curved portion is greater on the port foil:

    click and expand---
     

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  10. Doug Lord
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    Doug Lord Flight Ready

    MPX Test Model--------Dress Rehersal

    Rigged the boat with foils and even the Code Zero. This time everything fit perfectly and she's definitely ready to sail. The only piece missing was the Wing Tip, which I discussed last page or so(page 88, post 1311). Lot's of sail! Sails looked good-the jib was cut down a bit because it didn't fit last time-looked real good today.Moderate tension on the GDC(gaff control device) and the main looked real good filling in almost zero wind and tacking with no binding-just excellent. This was the first try with the Code Zero and it fit perfectly. Both sheets are ok -just the right length. You can see the new shroud position clearly in some of the pix. I moved it out and way back to reduce load and facillitate getting more tension on the jib. The switch out between jib and Code Zero was a piece of cake-simply a matter of unhooking the jib retainer snap, remove the carbon tubes and insert the Code Zero sprit-worked smoothly and simply. The shrouds now have two adjustments: 1) a macro adjust which is nothing more than a bowsie, and 2) a fine adjustment with a miniature turnbuckle.
    ------------------
    Also measured the rigged CG of the boat and that shows that 75% of the load(15.85lb) will be on the main foil/leeward ama foil and 25% of the load(5.29lb)* on the rudder foil-excellent foil loading.
    *static-underway foil lifts very slightly or pulls down-switching automatically.
    Other notes: (see specs in post 1307) At takeoff speed of under 5mph(4.35 knots) :
    1) main foil(symmetrical, set at +2.5 degrees) lifts 10.63lb @ a lift coefficient of .9(max down flap),
    2) ama foil(asymetrical,set at +3.75 degrees) lifts 5.22lb @ a lift coefficient of .6
    3) rudder foil(symmetrical, set at zero degrees) has a nominal load of 5.28 lb but at a rig pressure of .2 lb/sq' has virtually no load. So there should be very little ,if any, pitch up at takeoff.
    -------------------
    UPDATE: 6/9/14 One thing I noticed Sunday was that the main foil was supporting a lot of the boat load sitting on the ground. I knew it was low but that low was dangerous because if the boat heeled it could conceivably break the main foil, So today I lengthened the legs and moved the F & A tube to the bottom so the foil wouldn't hit it.

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    click,expand and click again for best view---
     

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    Last edited: Jun 9, 2014
  11. newcat

    newcat Previous Member

    Best of luck with the testing! That is simply, one bad *** looking model.
     
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  12. zerothehero
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    zerothehero Junior Member

    Doug, looking at your first pic the water in the background looks ideal for a test. Hope you git the boat wet.
     
  13. Doug Lord
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    Doug Lord Flight Ready

    MPX Test Model

    ===============
    Unfortunately, the beach in front of my place is all big and small slippery rocks. I don't know anyone with a small powerboat -that could work. Without the boat I wouldn't sail here. Where I'm going is still part of the Banana River but protected on two sides with SSE wind(normal for this time of year). Once I have confidence in the radio and my installation it won't matter. The boat is ready-just needs the Wing Tip before I get into it too much. If it was to pitchpole now the radio gear would be likely to bite the dust-the thing is very well sealed but it's not meant for full submersion. I don't expect it to be prone to pitchpole. Also, I have to redo the main at some point to make it reefable but not for a few months.
    -----------------
    UPDATE-6/10/14- I've got a guy who will come down and take video and then upload it to my youtube channel! Fantastic because my only camera only takes 30 seconds of video.....
     
    Last edited: Jun 10, 2014
  14. Doug Lord
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    Doug Lord Flight Ready

    MPX Downforce

    Some who have paid attention may understand that the mainfoil is capable of creating downforce which will add to RM. What some may not understand is that since the boat is heeled a component of the downforce is to weather just like when a Moth is heeled to weather a component of the mainfoil lift is to weather. I did this sketch for Wolfgang on the German forum:
    click and expand for best view-

    Sketches, left-MPX downforce, Right-Moth Veal Heel--
     

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  15. Darth Reapius
    Joined: Mar 2014
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    Darth Reapius Junior Member

    What's going on Dougy, its been 3 weeks and 2 days since testing has begun... Has it been tested yet? Or not... If it's failed and you're delaying just say so, cause it'll get to the point that no one's following it anymore... Just constructive feedback, what're you spending all the time doing?
     
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