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

Fire Arrow Foiler / MPX Foil System Testing and Development

I've posted a list of the history of the development of this boat with all the related videos on page 120, post 1787 but I'm going to add another list and that is the things the worked the way they were supposed to-or better. The last video showed some major accomplishments of this design so far(updated 1/14/15):
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A) The boat foiled in a 5 mph wind.There is more to it then that: the wind was so light that the main hull would not have flown without the main and rudder foil working perfectly-no chance!
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B) the boat foiled in a 5mph wind at a weight of 21.13 lbs+ with just the main and jib. That is a major accomplishment because the main and jib have a combined sail area of 3390 sq.in. which is 160 sq.in/lb. The production RC foiler I designed 14+ years ago(F3) also foiled in a 5mph wind but she was 8lb with 1668sq.in. of sail or 208 sq.in. per lb.!
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C) This boat foiled using two completely different altitude control systems-for the first time on any size trimaran anywhere, as far as I know:
a. The main hull uses a dual wand controlled flap equipped main foil to help the boat fly in light air(see "A" above!) and to add righting moment in stronger wind,
b. The amas used a refined version of UptiP foils, pioneered by Team New Zealand in AC34, for the very first time on any trimaran anywhere as of July 24th 2014! My design for the Fire Arrow foils attempted to create a foil that would require little or no adjustment while foiling while keeping the ama flying as the main foil unloaded and the boat sped up. There are pictures showing this actually happening-"A" and "B" below illustrate the ama flying before the main hull while keeping the ama at about the same altitude even when the main hull flew-so these UptiP foils worked under two completely different load and speed cases-can't get much better than that. I think that the ama foils may have to have their AOI(angle of incidence) adjusted down during high speed sailing but we'll see down the line. No adjustments were made to the ama foils while making the last video.
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D) The foil configuration used by the Fire Arrow, as mentioned under altitude control systems above, is a one of a kind with tremendous advantages-particularly for an over square platform: thanks to the wand controlled main foil the boat will fly the main hull in very light air which would be impossible if one waited for the sail force from the rig to allow the main hull to fly. The significance of that is that the oversquare beam is not a hindrance to light air performance and adds tremendous righting moment in stronger wind due to the very wide platform. But, the main foil isn't finished yet: as the boat speeds up the main foil is unloaded but as soon as it is required the wand controlled foil will add righting moment to the boat equivalent to half the boats weight or more! It does this because as the apparent wind increases and the boat heels a little more the leeside wand reacts by raising the main foil flap and that causes immediate downforce(righting moment).
a. when the mainfoil is unloaded or creating downforce it "works with" the rudder foil in pitch control giving this platform tremendous resistance to pitch excursions compared to almost any other boat.
b. the main and rudder foil together control the ride angle of the ama foil so that it is incapable of any sort of pitch reaction on its own-either up or down.
This was one of the things so evident in the video and one of the great successes of July 24th.
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This doesn't mean the boat was perfect in the last video-I, as well as a few others, have pointed out areas that need work. We haven't sailed in strong wind with the boat working this well and there is plenty of work to do. But I wanted to take a few minutes and point out the things that were successfully accomplished on July 24th, 2014.

Pictures-see paragraph "C" above:

 

Douglas, old mate.
Time to give it a rest.
Half, maybe 75%, maybe even more, of the huge number of hits on this thread, have to be yours truly repeating yourself.
Perhaps time to start building a real boat?

 

Fire Arrow Foiler / MPX Foil System Testing and Development

Thanks for the comment ,Gary. Still have more testing to do. I try not to repeat myself, unless I have to. A couple of the "repeat yourself" gang have made comments that show they never read the thread, so what am I to think? Do I need to repeat that??
Seems to me the vast majority of readers find what is here interesting or it wouldn't be the thread with the most viewers in the "Multihulls" forum, would it?.
I try hard to let people know whats going on with the Fire Arrow as well as with some other projects and development like the "Ctwist batfoils".

 

Something interesting I found. I know it is a canoe to start, but it has planing amas, and main hull foils. Check this one out. http://smalltrimarans.com/blog/?p=12406

 

Thanks R-that is just fantastic! He shows a second set of foils actually lifting the main hull-not 100% clear but great foil assist on facebook.
Heres his video:
http://vimeo.com/102648837

 

Fire Arrow Foiler / MPX Foil System Testing and Development

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The whole idea of a model is to, relatively inexpensively, test a design to achieve proof of concept to justify building the full size version. The Fire Arrow testing so far has been very successful showing that the wand controlled main foil works to lift the main hull when there is not enough wind to do it. UptiP ama foil testing has shown that in the conditions sailed in so far that the foils work 100% perfectly.
There is more testing ahead but if that testing goes as well as the testing so far it will prove beyond a shadow of a doubt that the full size boat is viable. However, there are conclusions that can be drawn now regarding the foil system and the model as a whole:
1) the basic foil system consists a.) of a wand controlled main foil and b.) UptiP ama foils arranged on an oversquare platform. In the conditions we sailed in in the last video the foil systems two main components worked 100% flawlessly in a 5mph breeze. They worked exactly like they were supposed to. That shows that the foils are in the correct position fore and aft and athwartship.
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2) The model works well at a 21.13lb displacement equivalent to a 941lb sailing weight full size the CG is in the right position to allow excellent pitch control while foiling. This is equivalent to foiling with three people and 29lbs of gear.
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There is more about all of this at the top of this page and on the previous pages.

 

Fire Arrow Foiler / MPX Foil System Testing and Development

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That says a lot about you,Richard. My thread has the highest viewership of any thread in the Multihulls forum!
Had you taken just a little time to read about my boat after only the SECOND test sail you would know the story of the the two pictures below.
Oh, since you don't read the thread ,I should tell you that the Fire Arrow is a TEST MODEL of a 19.5' LOA by 22' wide sport trimaran. It uses UptiP ama foils for the first time on any trimaran as far as I know. It uses a dual wand controlled main foil to fly the main hull(model and full size) in a 5 mph wind(4.35 knots) for the first time on any trimaran any where as far as I know. It's the first foiler of any type to use two different altitude control systems tailored specifically to the characteristics of the boat. It's amazing that you would form an opinion based on those two pictures without reading the text when they were first shown! You say there is nothing new in my thread but you have no idea what the story is on those two pictures-give me a break!
Both those pictures were screen shots,the "Splash Down!" pix from somebody on SA attempting to ridicule the boat. It was only the SECOND test video and was done in too much wind for the rig or at least borderline at 9-11mph. Remember, this is aTEST BOAT!
What I didn't realize was that the rudder sensitivity was too great so that when the rudder was thrown quickly hardover it had the effect of causing the boat to pitch up or in the case of trying to gybe caused a pitchpole. There were other problems I discovered after that video including that I had made the wands too long that contributed to the pitchups caused by the rudder. The main was poorly set, the jib sheet was fouled-plenty of small problems. The amas didn't fly because the ama foil area was too small. All of that was fixed before the first foiling video(last video of 2014).
Those two pictures below have zero relevance to the Fire Arrow design, they're just a by-product of testing and getting it sorted. In the last video, the boat foiled well and was rock steady in pitch. The 3rd, 4th, 5th and 6th pictures below are representative of the boat working nearly perfectly. The only problem in the last video was that using the radio dual rate and expo, I desensitized the rudder too much making it hard to tack. The boat foiled in a 5mph breeze in waves left over from the previous night.
Oh, since you don't read the thread, I should also mention that the crew on this boat will never sit on the "outrigger"! They sit on either side of the cockpit whether just one person or four people. The Test Model has been shown to foil in light air with the equivalent weight of almost 4 people aboard. This boat will be easily single handed.
READ the top post on this page!
A detailed summary of what was wrong,what was right and all the fixes and changes through the first foiling video can be found on page 124.
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The first posting of the "Take Off" and "Splash Down" pictures(as well as a picture of the same radio problem in another RC tri) was on July 5th,2014(a little under three weeks before the first full foiling video) in post 1495 here: http://www.boatdesign.net/forums/mu...f-righting-trimaran-test-model-36058-100.html

 

Fire Arrow Foiler / MPX Foil System Testing and Development-self-righting

I've been thinking a bit more on testing the self-righting capability of the Fire Arrow. The boat is likely to be extremely difficult to capsize because of the design of the high dihedral crossarms and the buoyancy of the ama and "curved piece". It probably isn't possible unless the mast breaks.
But pitchpole is another story. And that may not be so easy to test since the original idea was to put 175lb of lead in a "bulb" at the juncture of the daggerboard and main foil. But the test model is close to max weight now. 175lb is 3.9 lb in "scale weight" and I think that's too much but I guess I'll try it when Dan and I start testing again-after I get the "great" video we're hoping to get right off the bat.
I just saw this video of the Orion and I remember that there was an rc cat that used the same system to right from a capsize-but not from a pitchpole.
It got me thinking that if the Fire Arrow was pitchpoled without the extra ballast the mast heel would probably be close to the surface. I have an idea that with the hull almost vertical if the forestay or a separate line from the top of the mast could be tightened as the shrouds were eased off the thing might right itself. I'm pretty sure it would automatically right itself from a pitchpole with the ballast at the bottom of the daggerboard but this might work as the sealed wingmast and masthead buoyancy is pulled under water by the forestay. We'll see.....
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More: see the sketch below showing the approximate position of the Fire Arrow after a pitchpole. This points up one of the GREAT advantages of this fairly wide main hull for a "sport trimaran" and that is the tremendous buoyancy of the bow. And because she is a foiler the mast is further forward than it might be on a seahugger tri. She won't be too stable in this position....
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Here is the Orion video:
https://www.youtube.com/watch?v=655COFngiQA&feature=mfu_in_order&list=UL


Click on sketch for better view:

 

I think I found an example of your system working on an actual boat!

 

Fire Arrow Foiler / MPX Foil System Testing and Development

Similar, but the wand is on the forward foil instead of the main foil and there is no ama foil. I saw this picture a couple of years ago and bought Kotoro Horiuchi's book to learn more. No mention in the book, unfortunately.

 

What the heck is going on in that pic. Two hulls flying but no load on the main sheet -->sail?

I think he is being towed. Note the wake out past and ahead of the flying hull.

I presume no T-foil on rudder since it is still flip up standard on CLC tri.

 

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It was just a test of the foil system and he was being towed. Kotaro Horiuchi, the designer, is one of the greatest hydrofoil pioneers in history. The boat has a lifting foil with a strut and wand forward, a main foil in the middle, and a rudder without a foil(I think). Here is the boat level but still being towed(click and you can see the tow line) :

 

Fire Arrow Foiler / MPX Foil System Testing and Development

Fire Arrow picture test. I tried to create a larger,clearer picture-no success.......
click for best--

 

Glad to see it looks like it's working better! What still needs to be done on the model?

 

Fire Arrow Foiler / MPX Foil System Testing and Development

Thanks, RC.Those are two of the pictures from July 24th, 2014-the day of the first full flying video. Still have to change from a "normal" jib to a Hoyt jib boom.