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

MPX Test Model

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Thanks, Paddy!

 

MPX Test Model

Here is more detail on the dual wand system for the mainfoil:

Pictures- L-R-1) The plate that supports the wand axle can slide slightly fore and aft to change the angle of incidence of the main foil which is attached at point "A". Point "B" is where the pushrod from the main foil flap is attached. Point "C" is where a line to the tension spring is attached-this spring holds the wand against the water so it can provide altitude feedback.Points "B-C" are on the rocker arm that transmits wand altitude feedback to the mainfoil flap so that the preset altitude(+angle of heel on this boat) is maintained. Point "D" shows the rotating axle to which the dual wands are attached., 2)-3) show different views of the wand system., 4) the part of the wand to the left is the "paddle" whose concept was invented by Dr. Sam Bradfield-the idea being to smooth out wand input by allowing the wand a degree of planing.The MPX paddles are made of thin carbon that can flex under load. Paddles of different shapes and sizes are common on Moth foilers. On the F3, when it was first launched we heard this very loud buzzing sound from over 50' away: turns out it was the dual independent mainfoil wands. They were circular and as soon as they were squared off the noise and high frequency vibration stopped. These first MPX wands are set for a main hull altitude of about 6" corresponding to an angle of heel of about 10.75 degrees. They are not yet adjustable but will be for an 8-12" altitude(angle of heel up to 17-20 degrees for testing) or they can be disconnected to allow manual control.

Click and expand for a better view:

 

MPX Test Model

Better late than never: the story today is that I'll have the main, jib and Code Zero..........this week. Ok, right.

 

MPX Test Model

More wand detail:

Pictures,L-R, 1) view of dual wands from aft-angled out 15 degrees-keeps windward wand clear., 2) wand at 45 degrees from horizontal is equal to flap neutral. That is the flight altitude on a "normal" wand equipped foiler, but on this boat it represents a nominal angle of heel of 10-11 degrees; this angle is dependent upon the flight altitude of the ama due to lift from the ama foil. The wand allows early main hull take off with a Cl of .9 to 1.1 and subsequent rapid unloading of the main foil occuring with a slight flap-up wand angle two to five degrees. The wand can also create downforce at higher flap-up angles or be disconnected for manual radio control.

 

C section cross beam???

Wow, a C section cross beam, I want to see that engineering program!

http://www.youtube.com/watch?v=TFjxEfg_mEw

at the very end of video.

 

MPX Test Model

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Welcome to the forum ,Jim! Bradfield used a "D" section on his Osprey-can't tell from the video what section was there?
You might want to post this in the 34th America's Cup thread-it would be a bit more relevant there.
How's your model coming?

 

This is a great video interview with Magnus Clarke about the new C "FYH". It also has a very interesting comment about 8:55 in :
http://vimeo.com/72619588

 

Hi Doug, Lofted plans, ordered airfoil cores in NACA 0008 and 0010 for plugs. I will do the foils first, then start on the hull plug.

 

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Good Luck, Jim!

 

MPX Test Model

Excellent very large RC AC 72 project on this RC forum-wing rig and all should be absolutely fantastic!
http://www.rcgroups.com/forums/showthread.php?t=1887900 This is the first page-there are only 5 pages-scroll thru them to get an idea of Johns boat.

 

I have ben following it since may, just posted my plug source for foils.
I'm on rc groups every day.

 

Golden Oldies

For everybody thats been following the build of the MPX here is a special treat( this video just turned up today from my old webmaster-may be more F3 coming if he can find it) : years ago I used to manufacture rc sailboats-these are some of them starting with the F3 foiler, the worlds first production rc sailing foiler and:
1) the worlds first production rc symetrical spinnaker boat( America One),
2) the worlds first production rc asymetrical spinnaker boat( Melges 24 RC)
3) the great Flyer 3 trimaran that served as a test platform for the design of Dr. Sam Bradfields 40' Skat foiler:
http://www.youtube.com/watch?v=BRJDrWSZE6o&feature=youtu.be

 

MPX Test Model

I'm assembling the main foil flap and pushrod, then adding that to the mainfoil and finally-probably tomorrow- adding that assembly to the daggerboard. Very tedious but fairly exciting work as the heart and soul of the boat comes together.

Mainfoil flap pushrod axle:

 

34th AC

Here are a couple shots of the mainfoil with the flap assembled. Much more tedious than what may appear. The flap hinge is made of .002" adhesive backed mylar. It was first sanded on the top surface and each side of the hinge was cut out in little reverse "hat section" shapes. Then pieces of .02" carbon were cut to fit over the mylar. The reverse hat section acts as bonding area and acts as a backup with the carbon/epoxy to retain the mylar.
The pushrod axle(see above) was bonded into the top flap section and then the flap was assembed and the top and bottom pieces bonded together.
The mylar makes an excellent hinge with virtually zero friction and allows 30 degrees flap down and 20 degrees flap up. The mainfoil is ready to be bonded to the daggerboard very carefully so as not to get any resin in the flap axle area or on the pushrod or on the hinge or in the space at the ends of the flap. The rudder and rudder foil are ready to be bonded as well.

click---

 

jens Kraub

Hallo
thanks very much for your good job on your cats models.

do you know Jens Kraub email adress? I am looking for a good and safe catamaran base to work out my project of sail with adjustable curvature

many thanks for help