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Dario Valenza along with many others (including me) has been doing much research on foils-particularly for the A Class.

This is a segment published Wednesday December 10, 2014:

 

Active foils with mechanical sensors tend to be at a disadvantage in light winds and marginal foiling conditions because there is a drag penalty associated with the control system.
In non-foiling conditions the sensors can be disconnected and retracted. But then no lift is available so any puffs would see the passive boat move ahead in foil-assisted mode.
Arguably the active setup is also heavier depending on where the sensors are located and how they connect to the foils.
So on a small cat the passive foil would have the competitive edge in very light winds.
The exact crossover remains a subject of investigation and will be found to depend on variables such as displacement/length ratio, sail area/wetted area ratio and the exact design of the foils...
Once foiling the active system requires less deliberate correction by the skipper.
This favours the less advanced sailor but probably makes little difference to the nuanced expert who is constantly making adjustments by muscle memory.
The crucial difference is this: An active foil can be smaller for a given takeoff speed because lift coefficient can be maximized when needed and dialed out when not required.
You can have an aggressively cambered foil on takeoff and a flat low-drag one at high speeds.
This is not impossible with passive foils. For example, the section used in the upper portion can have more camber than the one used near the tips.
But the compromise is more critical.
It is more difficult to have early takeoff and low drag at high speeds.

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Dario breaks lifting foils into two main groups: active and passive.

Active foils are those whose angle of incidence(wand/"feeler" moves whole foil-- like Hobie Trifoiler) or lift coefficient is varied(wand controlled flaps that change the shape of the foil like Rave, Osprey,SKAT, S9 and Whisper 18 ).

------

Passive foils include UptiP foils, surface piercing foils(like Hydroptere), and soon maybe surface piercing T-foils. I've worked on foil development for over 20 years and last year tested an UptiP foil that works similarly to a wand controlled foil and needs no adjustment whatsoever from takeoff on. It is set for the conditions and thats it. The foil uses an intrinsic 15 degree flap(iFlap) that allows extra lift for takeoff and then the flap rises above the surface reducing drag. A very experimental "Curved Twisted Surface Piercing T-foil"(Batfoil) is about to be tested and uses two iFlaps for early takeoff and should require no adjustment once dialed in on the test model.

Passive foils offer great potential for the very simplest incarnation of a lifting foil-zero adjustment while sailing and no moving parts.

 

 

Pictures-1)Rave wand controlled main foil, 2) Flying Phantom UptiP foil, 3&4) Batfoils,5) Hydroptere.ch with retractable surface piercing foils, 6) Batfoil ready to test :

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Active foils are really best understood as two* very different incarnations. The original wand controlled foils invented by Dr. Sam Bradfield were used on trimarans like the Rave, Skat and Osprey. Those boats were oversquare because the dual independent wands generated 100% of the righting moment . The Hobie Trifoiler worked on the same basic principle where "feelers" extended forward and instead of moving flaps they moved the whole board to generate all the RM for the boat.


Starting(at least) with Off Yer Rocker a new type of wand controlled foiler has emerged: movable ballast is used instead of the foils (in most conditions) to develop all the RM for the boat. This has some advantages because it reduces the workload on the foils allowing a much narrower boat to function with wand controlled foils. Examples include the S9 and Whisper 18.


The original active foil controls on the Bradfield boats and Trifoiler required an oversquare(or as close as possible) beam to unload the foils-the further apart they were on this type of boat the lower the foil loading.


* The next generation of active foils may well include electronic wands to control foil angle of incidence or change the foil lift coefficient(by moving a flap). Electronic incidence control may be adapted to UptiP and other types of passive foils-the movement required to enhance stability is quite small but the power required can be fairly large(so far).


My personal opinion is that passive foils will be the simplest and most effective type of foil-particularly if canted surface piercing T-foils can be sufficiently developed. This type of canted foil can, in essence, retract the windward main foil by simply heeling the boat about 4 degrees.


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Doug what you bring is always interesting, but it really is annoying when you compare, on equal footing, several designs with years of development in the water at full scale, with your concepts that have barely (trimaran), or never (the new cat), touched the water at reduced scale. (yes I am aware of your previous RC foiler that did sail, how could I not know)

 

if you were more careful how you present stuff, I for one would go straight to the substance instead of having to first try to unwind the distorted way you used

 

again, thanks for your contributions

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Sorry you feel that way. Development is development and a lot of foils and foilers started out as test models*. The testing I am doing has a great deal of potential and involves thousands of hours of design, research and development over a long time and that's why I brought it up. How you can say it's presented on an "equal footing" when I clearly state that my stuff is very experimental and has been or will soon be tested?? Sounds to me like you misunderstood what I said? But thanks..........

 

PS-This thread was started to allow a continued "discussion" of foils begun in Micheles S9 thread without further hijacking his topic.

 

*Hydroptere, Sail Rocket and the current Paul Larsen ocean speedster, SKAT, DSS, CBTF, Hobie Trifoiler and many more.......

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you've been claiming you're about to test something for the last 12 years.

 

Only thing I've seen is the little trimaran hop, hop, hopping across a pond.

 

I do recall some old photos of something that looked like a sunfish drifting along with a weird gaff rig.

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yep - that's the hip hop hoppity one. Congratulations. Too bad your short attention span won't allow you to refine it.

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Doug

 

Have you got any video of your model foiling for any sustained periods? Nice model, btw.

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Where is the video I saw earlier of Brad and Stevie foiling downwind in the A and then Stevie rounding the leeward mark on the wire? Facebook somewhere. That is an amateur foiling video that is impressive.

 

Hope Doug gets to the same level.

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Wow - 15 seconds of continuous flight.

 

That is definitely Hoppity, Hop Hop.

Not if you only see what you want to see.

 

Mr. Lord has a long history of pontificating grandiose claims of success.......while providing little to no actual proof.

 

A consistent theme of his is: If only _______ had/hadn't happened, then I could have effortlessly foiled all day.

 

***R. Thompson***

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Sorry you feel that way. Development is development and a lot of foils and foilers started out as test models*. The testing I am doing has a great deal of potential and involves thousands of hours of design, research and development over a long time and that's why I brought it up. How you can say it's presented on an "equal footing" when I clearly state that my stuff is very experimental and has been or will soon be tested?? Sounds to me like you misunderstood what I said? But thanks..........

 

PS-This thread was started to allow a continued "discussion" of foils begun in Micheles S9 thread without further hijacking his topic.

 

*Hydroptere, Sail Rocket and the current Paul Larsen ocean speedster, SKAT, DSS, CBTF, Hobie Trifoiler and many more.......

Doug

 

I genuinely wish you all the best in your development and your model looks, in the most part, great (not sure about the head of the main!). The problem that I have and it seems is shared by others is the fact that you give yourself equal or higher prominence than people who have done so much more than you and have built so much more. Dario doesn't just write. He has built and tested active T foils on cats, along with uptip, Z, and other foils. This is not only sized but his boats foil for as long as you want, not just for 15 seconds. You give Dr Bradfield something like 1.5 lines. You want to discuss the merits of passive vs active, yet you make no mention of all the work and history around the passive area but totally focus on your stuff.

 

I am sure there are more than enough people who would be interested in your work on its own, but when the sum of it is 15 seconds of foiling on a model, you really need to stop discussing you stuff in the context you are. This is why people get so pissed off with you. You start a really interesting topic and use it as a platform to force people to follow your ideas and argue for them. If you had left your stuff out of this thread, it had the potential to be the most interesting thread we have had for a long time.

 

Good luck with your model. I truly hope you get it to work well and enjoy the whole thing and I genuinely will read and follow its progress. My one suggestion is that based on a lot of testing done in a number of different teams, you will find everything works a lot better with a lower aspect ratio rig. Lowering the CoE of the rig is a big focus at the moment in most foiling situations. And in almost every case, foilers work best when upright :)

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This is an experimental cat using 20 degree canted wand controlled T-foils. The cant helps to reduce the effect of high and low pressure on the same side of a conventional T-foil(see illustration in Post 1). Kevin Elway is part of the team and Alan Smith from Australia helped with development. Another very cool aspect of the Vampire foil system is that the windward wand controlled foil is retracted , like UptiP foils, making this configuration potentially very quick.

More info here: http://www.boatdesign.net/forums/multihulls/vampire-cat-canted-t-foils-51329.html

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This is an experimental cat using 20 degree canted wand controlled T-foils. The cant helps to reduce the effect of high and low pressure on the same side of a conventional T-foil(see illustration in Post 1). Kevin Elway is part of the team and Alan Smith from Australia helped with development. Another very cool aspect of the Vampire foil system is that the windward wand controlled foil is retracted , like UptiP foils, making this configuration potentially very quick.

More info here: http://www.boatdesign.net/forums/multihulls/vampire-cat-canted-t-foils-51329.html

 

Hey Doug, providing a link to another forum that contains nothing more than you elaborating on your own views is just bullshit.

 

In that forum, in what again appeared to be a source reference, you provided a link to the Whitstable Yacht Club page where a small mention of the Vampire appeared so far down the page (Sept. 2014) that it required a text search to find it - and wasn't worth reading. This practice is just wasting people's time and further eroding your credibility. Not that it will make any difference to the foil sailing world...

 

With a Google search, I found a page with slightly better information and photo:

 

http://www.yachtsandyachting.com/news/178899/Foiling-Vampire-to-make-its-racing-debut

 

yandy116299.jpg

 

In its previous guise The Vampire, originally an M20 from Marstrom Composites in Sweden, has taken line honours over the last 4 years in the major UK and North European long distance races such as Round Texel, Raid de Houat, Kent Forts Race and the Three Piers Race. William and his team (Kevin Ellway, designer of the Exocet International Moth and Graham Eales the renowned Brightlingsea based boat builder) have added canted T foils with the intention that, when the development work is complete, the technology should be transferable to other catamaran platforms such as the Tornado, F16 and F18. On the water trials have been ongoing at Brightlingsea and the development team have reported downwind speeds consistently over 20 knots, peaking at around 26 knots.

 

And a another page depicting "its previous guise" using C foils:

 

Foiling Vampire - project history

http://thamesraiders.blogspot.com/2014/07/foiling-vampire-project-history.html

 

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And yet another page with a video of the Vampire sailing on its T-foils::

 

Brightlingsea’s Vampire Programme (scroll down)

http://www.sailbrightlingsea.com/sailing/technical-development/overview/

 

 

The concept was developed by fluid dynamicist Kevin Ellway, designer of the Exocet International Moth, the first to be designed completely using mathematical models. Scores of virtual moth designs were “flown” before putting the final design into production, and the same general approach has been taken with the Vampire project. He is now working on rig developments to get the best out of the platform.

 

The foils have been built in Brightlingsea Essex by Graham Eeles a specialist boat builder engaged in a number of innovative projects. He has converted the desktop theory into strong and practical foils and has been coaching for the early test outings.

 

You're not new to Internet forums - get your game on, dude! Or just STFU.

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And there couldn't be a thread about foils with mention of UptiP foils. You have designers, sailors builders etc calling the foil invented by TNZ almost every letter of the alphabet from "L", "L/V", "J" and probably more. This for the most significant foil development in over 50 years. You'd think it would have it's own name. Well, as is obvious in many threads here many people do not read-they go with their "feelings"!

The fact is that the spectacular foil invented by TNZ DOES have a very specific name:

 

from here: http://www.cupinfo.com/en/americas-cup-pete-melvin-foils-multihulls-13146.php

 

“At Team New Zealand, we developed a new type of foil that allows you to keep your height above the water more or less steady. No one had been able to do that before, at least not on a course-racing boat that was not going downwind. We developed that mostly on our SL33 test boats -- they came with the stock constant curvature “C” foils and with those kinds of foils, you can generate 50% boat weight lift before they get unstable. But we noticed that when we could get one boat up fully foiling for a few seconds it would really accelerate away from the other boat – and that got the wheels turning. How, with such a huge potential benefit, can we achieve stable flight downwind? So our design team came up with the “up-tip” type of boards.(emphasis added DL) We refined those on the 33s and our 72 is designed to do that and fortunately it worked right of the box.”

 

Or "UptiP" foils !!!

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Doug - very excited to see the new video. Must be a tremendous number of changes if it takes 11 months to go from 1 sail to the next.

 

Hint - if you don't have a videographer, Go Pro sells POV hands free mounts that work really well.

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Actually, none of these recent posts are from Doug Lord.

 

The real Doug Lord died six weeks ago and this is just a LordBoT posting. Doug was so obsessive in life that even his BoT is a numbskull.

.

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Here ya go Doug. You won't need the kid to get out of school and video anymore. You could order this and be sailing/videoing in a week.

 

https://peakdesign.com/store/pov-kit&currency=USD&language=en?gclid=Cj0KEQjwyIyqBRD4janGs5e67IsBEiQAoF8DGoFn64Ii5Ly8otGnPC3FaLKZ1qOzZQlPk1iVtjzkqFwaArOQ8P8HAQ

 

I'm sure you have countless hours of great, stable foiling, and it's just a shame you couldn't get some guy to video it. The designers out there like Chris O need to see how this works so maybe someone with more resources, but not the forward thinking capabilities you possess, could scale it up to life size.

 

You're welcome.

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Ya know what, that was rude. tell ya what, PM me your address and I'll have them send you the mount, on me. I'm sure you already have the GoPro given all the videos you've posted already.

 

I can't wait to see the little red tri ripping it up.

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Actually, Razor.... I'm just flabbergasted that Doug has not been inundated by the foiling folks in Florida who would just love to be close enough to the head foilista to smell his sweat. Certainly, volumes have been written about this earth-shaking design and the word is out in the community to the extent where there should be a line of qualified shooters who are just itching to get some prime footage of history in the making.

 

That Doug can only wangle the help of a part-time football coach to professionally shoot these wondrous moments really confuses me to no end. But then, I'm not a Foiling Bubba and some of the fizz may be well above my pay grade. Maybe real cameramen are just too intimidated by Doug's global reach and they feel inadequate.

 

I do have an idea for Mr. Lord, though.... He can get his butt on down to the nearest Joe's Crab Shack and offer to pay for an Early Bird dinner for a pair of spry, New York pensioners if they will only come on down to the local pond and shoot his video for an hour, or so. Better yet.... Doug could front a full tilt, Old Timer's buffet at the water's edge and I'll bet that it would draw a serious crowd of retirees from which he could then cajole his cameraman and launch help... Plus he'd get to meet a fresh new gaggle of folks his own age and then go off, apres RC session, to play some canasta.

 

.

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Now be nice. I'm really trying to help Doug out here, I know he's resource constrained but I'd like to help spread his genius.


Doug, if you don't have a go-pro, I bet we could raise the funds here and get you one right quick.

 

I'd pay $50 to see a good hour of foiling.

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Hey, that could work!

 

Clean could see how the heathens do it, and then how the genius does it.

 

We don't appreciate genius enough these days.

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Doug doesn't take too well to benevolent financing. If you remember back some years, a collection of folks tried to front an airfare and lodging for Doug to attend the Moth Worlds when they were held in the Gorge.... and he defiantly blew them off.

.

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Hey, that could work!

 

Clean could see how the heathens do it, and then how the genius does it.

 

We don't appreciate genius enough these days.

 

 

Sorry.... I deleted the post because it seemed to be a bit too much and I'd only draw the iron wrath of Clean and we all know how awful that can be... Body parts everywhere, gore in the gutters, that kind of stuff.

 

Clean is the erstwhile Idi Amin of the sailing community.

.

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Doug doesn't take too well to benevolent financing. If you remember back some years, a collection of folks tried to front an airfare and lodging for Doug to attend the Moth Worlds when they were held in the Gorge.... and he defiantly blew them off.

.

Yeah, I was part of that, but I'm hopeful the genius will help out the heathens this time.

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Boats like the Skat, Rave, Osprey and Hobie Trifoiler were designed to use the foils to develop all the righting moment for the boat. According to Dr. Bradfield and Greg Ketterman a properly designed dual independent wand/feeler system has a net gain once lift and drag are factored in. And they have virtually unlimited righting moment-up to the structural strength of the boat.

To my knowledge a Rave, Osprey, Skat or a Hobie Trifoiler have never capsized as a result of losing lift from the windward foil. One of the reasons is that they are designed to be very wide to keep foil loading low. A narrow multihull trying to use dual independent wands/feelers to develop all the RM would be in grave danger of losing the windward foil.

Greg Kettermans comments on the subject:

HYDROFOIL SAILBOATS IN GENERAL
"Hydrofoil boats can be categorized into two categories; 1) Incidence controlled hydrofoils* and 2) surface piercing hydrofoils. The difference lies in the way the boat maintains the proper altitude above the water surface. A surface piercing hydrofoil boat maintains proper height by varying the amount of foil submerged. The boat raises up as the speed increases and reduces the amount of foil submerged and therefore the lift. The boat finds equilibrium at the proper altitude. An incidence controlled hydrofoil sailboat has a mechanism that controls the angle of attack of the foil to maintain the proper altitude. It is generally believed that surface piercing is simpler, but incidence control is more efficient. In reality, it is the method that works with fewer problems that is simpler.
From the beginning it was felt that incidence control was better suited for a sailboat even though most of the existing hydrofoil sailboats were of the surface piercing type. There are many advantages of the incidence controlled foils; however, the most important is what I call the DLA (dynamic leveling affect). This is the increase in righting moment or stability due to the ability of the windward foil to pull down. The DLA has little affect on the low wind performance, but it essentially makes the top speed of the boat limited to the strength of the boat. Conventional boats with a finite amount of righting moment can only extract so much power from the wind, but with the DLA, the righting moment is virtually unlimited.
Intuitively many people think that the added drag of the windward foil plus the increased induced drag of the leeward foil would offset the gain in righting moment, but calculations show and practice proves otherwise. The dynamic leveling affect not only produces a dramatic increase in top speed, but is also responsible for all the other key features that this stability provides.
The other major advantage of the incidence controlled foils is they are less affected by the waves and other surface affects. Drag and losses associated with the surface are the major reason incidence controlled foils are more efficient.
All hydrofoil sailboats have problems with ventilation; however, surface piercing foils have larger problems, because the foils are piercing the surface at a smaller dihedral angle which makes it easier to ventilate."

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Hey Occam, you wrote:

"I know he's resource constrained but I'd like to help spread his genius."

The danger here is that if you spread his genius any thinner, it will slip into the realms of being a Nano Coating and you will have created douG lorD - expert in Nano Technology......

 

He will then brag about having created the world's first cloak of impenetrability to:

  • shame
  • common sense
  • normalcy
  • reasoning
  • humility

to name but a few.

 

 

 

 

 

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Clean must be able to organise a sponsorship deal for Doug with Gunboat. With all the knowledge gained from his filming his models, they must be able to learn sooooo much, that they could include the Doug inspired mods into the production G4. :rolleyes:

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Toms Speers explanation of how UptiP foils work and should work:

 

The curved part of the vertical foil produces essentially the same lift as it rises. This is necessary to counter the side force from the sail rig, which does not change as the height changes.
Because the horizontal lift is constant but the vertical area is reduced as the boat rises, the leeway angle increases. It is the coupling of leeway with heave that is exploited by the L foil to provide vertical static stability.
The dihedral angle of the horizontal wing is set so that the angle of attack of the wing is reduced as the leeway angle increases. This satisfies the static stability condition that the vertical lift decrease as the heave increases.
Because the same horizontal lift is produced over a reduced vertical span, the sideways wash in the wake is also greater and the trailing vortices are more intense. This causes a coupling with the horizontal wing that increases the vertical lift, because the horizontal wing acts as a winglet for the vertical part of the foil (and vice versa). The dihedral angle required for vertical stability is greater than what one might expect by looking at the wing alone because it must overcome this wake-coupled influence. The result is there is a range of dihedral angles that provide positive vertical stability and a range of dihedral angles that are destabilizing in heave because of the coupling with the shed vorticity of the vertical part of the foil.
Although there are times when the foil tip has broached the surface, this is not the normal mechanism for providing heave stability in L foils. The best performance is obtained with the hull just above the wavetops and the wing submerged well below the surface. The leeway-modulated heave stability is still effective in this condition, and the induced drag is minimized.
Canting the foil inboard has the effect of increasing the dihedral angle of the wing, which enhances the heave stability. The vertical lift is spread over a greater span because the curved part of the foil is oriented to provide more vertical component of the force. This reduces the induced drag due to the vertical force. However, the induced drag of the horizontal force would be increased, so cant is typically used off the wind when the side force from the rig is less and the side force produced by the foils is correspondingly less. The foils still have to support the weight of the boat, so the vertical force is not lessened, but the relative proportions of vertical and horizontal force are changed, making the canted foil better suited to the operating condition. Cant allows the leeway-modulated heave stability to be increased an an acceptable penalty in the induced drag because of the lower side force and the higher speeds, which also reduce induced drag.
Upwind, the foils are canted to their vertical position to minimize the induced drag from the high side force and reduced speeds. The reduction in horizontal wing dihedral angle with vertical cant impacts the leeway-modulated heave stability, which is why it is much more difficult to achieve stable flight upwind than downwind. The crew had to be more active in trimming the wing and foil to deal with the reduction in natural heave stability, which was very hard on the grinders when flying upwind.
Whether canted or upright, the mechanism for providing natural heave stability was still the coupling between heave and leeway, which led to a reduction in vertical lift because of the designed-in coupling between leeway and vertical lift by virtue of the wing dihedral. Reduction in horizontal/vertical-lifting area due to the foil tip broaching the surface was not part of this primary source of heave stability. Allowing the tip to broach the surface had big penalties in terms of induced drag and increased leeway due to insufficient vertical span.
Ilustration by Dario Valenza, Picture-DL-UptiP ama foil for Fire Arrow test model, version one, and version two:

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Come on Doug! You seem to be trying to fool people that you want a serious conversation about foils, yet you are using this thread as little more than an opportunity to push your own stuff. It is either rediculously egotistical or totally delusional. For instance, why would you illustrate a post about up-tip foils with your own, totally unproven foils (15 seconds of flight is not proven) when there are so many images available of foils that illustrate the point even better and which come from boats that are well proven. You can easily find pictures of foils ranging from the original up-tips from ETNZ and other AC72's through foils on GC32, G4, AC45T, AC45F, Flying Phantom, NACTA F20 and many more.

 

Half of your posts on this thread have contained photos or words about your foils and your experiments. Please don't kid yourself that what you are doing in any way compares with the work of every other person you have mentioned, yet you feel that a thread on different foils deserves 50% of posts being about your stuff.

 

Nobody has any objection about you posting about what you are doing. In fact, many are interested, but make sure it is on a thread that isn't dressed up to look like something other than a thread about the stuff you have built. This could have been a great thread. You are responsible for it not being so.

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Toms Speers explanation of how UptiP foils work and should work:

Source? Or did you just make that stuff up and put his name on it? And the diagram by Dario Valenza?

 

Tsk, tsk... Very poor form, old chap.

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I can testify, you can find this prose on BoatDesign.net and it's actually Tom Speer who wrote it; his academic writing is easy to recognize because always crystal clear for the concepts he wants to explain, Proasailor it s a no brainer about that.

 

Regarding model boat, I am afraid it will be almost impossible to have stable foiling if you don't have a few gyroscopes like R/C helicopters. How and where to connect the gyros, you should ask a specialist.

 

Stability is also dependent on the moment of inertia which is proportional to the mass and square distance from barycenter

 

It's a bit crude calculation but a model 5 times smaller than a beach cat and 100 times lighter will react (5^2) x (100)=2500 faster than a beach cat for the same gust.

 

That is why I don't believe it's actually possible to achieve very stable flight with boat model, even if you push the stability diedral to the max, I am afraid it won't be enought.

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Catnewbie, there have been many RC foilers used as test models that are extremely stable including my Fire Arrow and F3. The Fire Arrow uses an extremely unique foil configuration that allows it to fly in very light air and incorporates an UptiP foil on each ama for the first time on any trimaran.Most RC tri's have used surface piercing foils and there are a very few tri's and cats that have used wand based systems. People like Dr. Sam Bradfield, Greg Ketterman and Paul Larsen(and many more) have used scale RC models to accurately test foil concepts.

This boat, by PET3D, shows an example of a very well dialed in foiling tri that does several foiling gybes. Gyro's aren't required on a well designed foiler.

 

 

 

 

PIctures: Fire Arrow test model, 15+ year old F3-worlds first production sailing foiler designed and built by me and Dr. Bradfields test model tri used to test foil concepts for his 40' SKAT-platform is one of my 68" Flyer ^3 tris(see video above of boat w/o foils) :

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Ok that's quite convincing, but why don't you use end-plate for the sails on your models, it will not bother any crew to have no space below footsails

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...there have been many RC foilers used as test models that are extremely stable including my Fire Arrow...

 

 

I totally disagree with your claimed performance for your "Fire Arrow". It has never shown itself to be EXTREMELY STABLE and when you take away the excessive edits in the video clip, you see that the boat is pretty much a flop. It darts, uncontrollably, out of the water and then crashes back to the surface without any lifted consistency. It sure can not maintain controlled flight and has never demonstrated such a capability. Simply repeating your own claims numerous times does not make for a truth.

Here's a truth: the boat has not shown itself to be anything but a waste of time. You have abandoned the project with a litany of excuses about not having anyone to help you to get it on the water and have built another boat in the interim. The claimed, miraculous tri, has not done anything even close to your claimed hyperbole and it remains a failure as it collects dust somewhere in the darkest corner of your hovel.

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Ok that's quite convincing, but why don't you use end-plate for the sails on your models, it will not bother any crew to have no space below footsails

 

On the Fire Arrow test model, it is a scale model of a 19.5 "sport trimaran"- and I wouldn't use a lower endplate on the full size boat-just not worth it on a boat not designed for top end speed. BUT-the "Wing Tip" on the top of of the main serves as a sort of vertical endplate while containing the buoyancy required to prevent turtling.

On the new D4Z cat it will use endplates after the first few sails-mainly because of the success Oracle had by sealing the foot of the main.

The F3 as a production RC sport foiler and at that time(15+ years ago) I wasn't convinced of the viability of a "floating endplate".

 

PIX- main and jib endplates on D4Z, movable ballast system:

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Here's some news.... I find myself agreeing with Simon when he suggests that Doug is not starting this thread to actually discuss anything significant in the foil design/build, or use, area. It's just another of his insecure, "hey, look at me" nonsense threads in which he pummels the viewers with relentless images of his goofy model boats.

 

Since you are already plowing the now dead field of your models, Douglas, how about shedding some light as to when you will actually revisit the trimaran design and operation fulfillment for the wonder boat that is supposed to, "change small trimaran sailing forever and put paid, once and for all to the myth that small tris can't beat beach cats"?

 

 

The "flunked out of class" Fire Arrow can't even get out of its own way. Beating a beach cat is ridiculously out of the question. Imagine spending four years of your life on a boat that never worked and was abandoned by its designer as a broken promise of a seriously distorted vision?

 

.

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BUT-the "Wing Tip" on the top of of the main serves as a sort of vertical endplate while containing the buoyancy required to prevent turtling.

 

Is that another name for a Gaff (stiff upper batten) with some foam on the sail?

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doug, how many hours have you sailed the fire arrow? actual sailing hours, on the water, net, excluding setting up on the shore?

 

those with small children will recognize the line from The Hobbit: C´mon! Give us a number! :-)

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Give Doug a break, the high school cameraman hasn't been available since last summer, so he's not been able to get out and sail it.

 

Now, my profuse apologizes if a physical disability keeps Doug from launching his boat. if that's the case, Doug, there's a whole group of helpful folks here who'd be happy to help you out.

 

I'm hurt that you haven't taken up my offer on the go pro. Hurt.

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Hey Doug - I have questioned your ability to comprehend basic stuff before.

 

You had written in another thread that the G4 would be capable of foiling under it's electric auxiliary - which is not the case.

 

You state in post #52 that Dr. Bradfield's boat is 18 by 22 feet.

 

But the video clearly states in the graphics that it is 18 by 20 feet.

 

Get your facts straight.

 

No one here can fathom your motivation for anything that you write.

 

You continue to write in a style that puffs up your own sense of self importance and tries to portray you as some sort of reference point.

 

Yet your poorly framed reasoning; the lack of respect that you show for other's reasoning; your sycophantic wailings; your childlike need to name everything with a crap-o-matic name and/or writing it with backwards capitalisation; and most damming of all, the poor results achieved by your models;

only leads those who can reference all aspects of this complex but compelling field, to conclude that, at best, you are a misguided enthusiast, and at worst, a deranged fraud.

 

Whatever it may be - Get Some Help - even if it is new reading glasses, stronger meds, adult reading classes, a friend, or better yet, a friend who would be prepared to edit and proof read your ramblings BEFORE you post.

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This is Dr. Sam Bradfields* last foiler-18' X 22'(foil tip to foil tip) wide with dual, independent wand controlled main foils. This is a bit different than the Rave in that the crew can supply part of the righting moment unloading the foils a bit. This video was in 7-8 mph wind and it appears that with a slightly bigger rig she'd take off in 5mph. The foil/wand* combination is retractable for beach launching and is very unique compared to most other wand systems-there is almost nothing but the shockcord attached to the boat from the wand system. The angle of incidence of both main foils is adjustable while underway which makes it simple to add to windward foil downforce when desired:

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There are three trimarans (Gitana, Exocet 19, Fire Arrow test model) experimenting with the use of UptiP foils on their amas:

 

1)Gitana, a MOD 70 is testing an UptiP foil on the port ama. And she is using "C" foils on the stb ama. She is using rudder T-foils on both amas. More in the "Offshore foiling " thread.

--

2) The Exocet 19 has been under development for over a year and uses an UptiP foil on each ama with a rudder T-foil on each ama. No word on when she'll actually be sailing.

--

3) NOTE: both Gitana and the Exocet need to fly the main hull-due to wind pressure alone- before the boat is full flying.

--

4) The Fire Arrow test model uses an UptiP foil on each ama along with a wand controlled main foil and rudder T-foil on the main hull. This is a unique configuration and the first tri of any size to use UptiP foils and the first to use different altitude control systems at the same time. The bi-foiler arrangement on the main hull controls the ride angle of the lee UptiP ama foil as well as allowing for increased RM in response to gusts(downforce)-automatically. Further, the bi-foiler system on the main hull allows the boat to fly in very light air-5mph(4.34knots)- way before it would fly with wind pressure alone. Because the main foil unloads as the boat starts to fly the pitch control is superior to any current trimaran.

 

Pictures-Gitana(from their site)Exocet render and Fire Arrow:

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I have a lot of interest in foils (I am even building my own KBHF). Every time I look at a thread with "Foils" in the title I have to sift through the DL bashing and find very little useful info.

 

SO, Here is my question.....

 

What type of foil profiles work for up tip 'J' foils as used on the G4, ENTZ ect... please be specific! is the vertical different from the horizontal? when does the change in profile happen? how is ventilation traveling down from the tip controlled?

 

Thanks in advance for any response not involving DL bashing.

 

Tink

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I can only speak to my UptiP foils where the vertical portion of the foil is a constant , untwisted variation on a 63412 section with a 10% T/c ratio. The up -tip portion of the foil is the same basic section to start with except twisted with "wash-in" (not washout) from zero to plus three degrees. In addition, one side is using what I call an "iFlap" which is nothing more than a molded in(intrinsic) 15 degree flap. The purpose of the twist and flap is to allow performance similar to a wand controlled foil-in other words, the washin and flap create lots of extra lift when going slow and as speed increases both rise above the surface automatically ,reducing drag.

The net result is an "automatic" foil that does not need any adjustment throughout the speed range while sailing. And it has ZERO moving parts.......

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Hey Doug you write:
This is Dr. Sam Bradfields* last foiler-18' X 22'(foil tip to foil tip)

 

As if that exonerates your error.....

 

The designer of the boat created the video and all the associated information released about it.

If the designer calls it 18 x 20 foot - then it is only correct that you do as well.

 

Instead in true DL fashion you take what ever individual piece of information that suits your agenda and run with it.

 

(If you are going to arbitrarily change the dimensions then at least be consistent with your madness

 

So, by measuring from wing tip to wing tip - laterally, you should also include the 4 feet of overhanging bowsprit and 8-10inches of overhanging rudder.

 

If consistency was applied we would be discussing a 22ft9' long by 22ft wide vessel.

 

Uh Oh - the vessel is no longer Oversquare - a fundamental attribute to be included within the Doug Lord Church of Scientology)

 

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I have a lot of interest in foils (I am even building my own KBHF). Every time I look at a thread with "Foils" in the title I have to sift through the DL bashing and find very little useful info.

 

SO, Here is my question.....

 

What type of foil profiles work for up tip 'J' foils as used on the G4, ENTZ ect... please be specific! is the vertical different from the horizontal? when does the change in profile happen? how is ventilation traveling down from the tip controlled?

 

Thanks in advance for any response not involving DL bashing.

 

Tink

 

This is written by Dario Valenza on Sunday, March 16,2014. Valenza discusses "acute L/V" foils(UptiP foils). Though this discussion is directly relative to his work with the A cat, some of his conclusions are enlightening for any UptiP foil:

 

SUNDAY, MARCH 16, 2014

Mythbusting
Some thoughts on our recent testing with heave-stable 'acute L' foils (L/V for short).

This experiment had one aim: To prove that a simple cheap upgrade is possible to convert existing A Class catamarans to stable foiling without major structural modifications.

 

The story so far

 

We knew from previous testing that L/V foils give stable foiling. Our conclusion was that the crossover speed was relatively high so the overall advantage of this configuration for racing would be marginal.

The complexity of 'tacking' the L/V foils tipped the scales in favour of adopting our 'comma' foils for production and racing. These proved competitive giving skimming flight with neutral stability when required and minimising drag when in foil-assisted mode.

 

After the Worlds we revisited the crossover numbers armed with new knowledge about kinetics and the tactical options made accessible by foiling. It is now beyond doubt that foiling will pay.

L/V foils maximise righting moment, are inherently stable and can be made to work within the rule.

 

While it is tempting to wonder whether there is some lateral breakthrough design somewhere within the 'four point' design space, all the evidence right now points to the fact that 'three point' foiling offers the best performance with consistent stability (and hence safety).

 

An objective application of existing A Class rules allows simple, cheap conversion. More tortured interpretations may require workarounds such as hinged foils or large cassettes.

 

Stretching Rule 8 to serve the interests of the 'no foiling' constituency adds no value but instead imposes complexity and compromises efficiency. It creates costs that bring no benefit.

 

A growing majority of Class members is asking whether a simple retrofit foiling solution would be feasible.

Any lingering doubts revolve around ease of handling and, especially, the difficulties of converting existing boats that may otherwise become obsolete.

 

Modifications

 

The foils in these videos are old Marstrom C boards with new horizontal legs bonded on.

The horizontal legs are a proprietary shape. Critical features such as the area, tip-up angle, twist and angle of incidence were determined in light of the work carried out over the course of our Paradox development programme. However the Marstrom verticals were not modified.

 

For some runs the foils were installed in the original cases of a Melvin A3.

For other tests they were mounted in the existing foil cases of a Paradox test platform. In the latter boat the rotating bearings at the hull and deck were replaced with simple plastic blocks.

 

In both instances the foils are held down by a rope led to a deck cleat. They are retracted using pre-tensioned bungee that pulls them up when the down-line is released.

 

Rudders are standard Paradox with some transom reinforcement added to the older boat.

 

Longitudinal placement of the foils on the Paradox is further forward than usual because that happened to be the arrangement on this particular boat.

Previous testing has already shown that, within limits, keeping the foils further aft gives a maneuverability advantage without adversely affecting foiling stability. At any rate, installing a simple foil case further forward is cheaper than putting in a cassette.

Findings

 

In short the transition is surprisingly gradual with drag falling away as the hulls rise.

Once 'unstuck', the boat rises more rapidly until the heave control features of the L/V foils come into play.

At this point the normal instincts of a cat sailor remain applicable. However there are a few interesting differences:

 

The most important lesson is to do less rather than more.

 

Pulling away aggressively in response to building wind strength can force a reduction in ride height, especially if it is done after the boat begins to heel in response to the gust. The foils automatically go to work to restore level flight but the momentary reduction in ride height does sap energy.

 

Once the coupling between steering and heel is noted (if heeled to leeward, steering into the wind will make the bow come up. Pulling away will make it go down), then one quickly learns to anticipate. The usual response of letting the windward hull rise then bearing away is somewhat modified:

 

As pressure increases, the best technique seems to be to ease the sheet a tiny amount, let the boat heel to windward ever so slightly, then pull away as normal. This results in addictive, exhilarating acceleration in total safety. Unlike a displacement cat where forward buoyancy gradually runs out, the foils provide more lift as pressure from the rig increases. The feeling is one of total immunity to nosediving (so far!).

 

It is easy enough to become accustomed to just trusting the foils and keeping steering inputs to a minimum. Obviously the boat will spin on a dime when foiling so the key is to be subtle with the tiller.

 

Heeling to windward a tiny bit helps to increase ride height when bearing away. This really boosts VMG downwind. Interestingly the same technique works upwind because luffing up to depower helps lower the bow and settle the ride height. But more on upwind foiling later.

 

For reasons I do not yet fully understand, Keeping the sail more open works better than strapping the sheet on. Letting the traveler down slightly (say to the hiking strap) and allowing a few degrees of twist causes the boat to fly higher. Closing the leech seems to lock the foils up so the boat settles closer to the water. More investigation is needed here because as speeds rise and the apparent wind goes forward, sheeting in will become necessary.

 

My best theory at this stage is that increasing sideforce causes the equilibrium ride height to decrease. This is based on the coupling between leeway and lift built into the L/V foil geometry.

Another factor may be that, since drag when foiling is so much smaller, it is not necessary to load up the boat with maximum sail CL. Instead the goal is to have the greatest drive force component exploiting fore-and-aft righting moment rather than resistance to heel...

 

Sailing downwind with both foils down could lower the crossover speed significantly.

Having both sides down effectively gives a pair of V foils. The reduction in foil area due to the inboard tips breaching the surface becomes the dominant heave-control mechanism instead of leeway-coupling. This is an advantage because stable foiling becomes possible at small sideforce values. It is important to note that this arrangement is draggy at higher speeds and definitely unstable as soon as sideforce becomes significant.

 

Raising the windward foil and relying on leeway-coupling effectively doubles righting moment whilst halving foil area. This is good when sail power is 'excessive' and speeds are very high.

In lighter winds the leeward foil would have to be bigger (if used alone) for the same takeoff speed. More importantly you would have to sail much higher to generate enough sideforce to fly a hull while trapezing.

 

In other words you would have to generate enough sideforce to lift the windward hull and enough speed to takeoff on one foil only. This is achievable at a much lower windspeed upwind than it is downwind. Having both foils down instead allows a very early takeoff while sailing deeper because righting moment is effectively halved and foil lift is doubled.

 

I suspect that top level sailors will gradually be able to bring down the critical windspeed for 'downwind windward foil raising'. But for now this option allows mere mortals to foil safely in as little as 6 knots TWS.

 

Conclusion

 

We have now proven objectively that it is feasible to convert an existing A Cat platform to stable foiling with minimum fuss and expense. The boat remains practical and exploitable but it offers a whole new level of performance.

 

On the emotional side, the feeling of foiling is just fantastic. I am sure that hundreds of Moth sailors already knew this. But it must also be said that foiling on an 18' cat while on the wire, and with no mechanical control systems is special in a wholly unique way.

 

It really is simple to learn and no outstanding athletic ability is required. I have no doubt that this will be the future. Many top level sailors agree. The only question for the Class is this: Will we be permitted to do it in a way that is simple and cheap or will we have to use complex and expensive workarounds?

 

After the thrill of the 'magic carpet ride', touching down feels like sailing through honey. It becomes frustratingly restrictive. This really must be tried to be understood. Hopefully many A Cat sailors are about to do just that.

 

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This is one of the first videos of Dr. Sam Bradfields SKAT undergoing sea trials. This boat was 40'LOA and used dual independent wands on the main foils for altitude control and RM. Dr. Sam had purchased one of my first Flyer ^3 RC 68" trimaran platforms which he used to test foil configurations for SKAT.

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Doug

 

Your latest post from Dario's blog is now over a year old and is based on what are now old assumptions and old gear. At the time, he was correct but compared with the foils that we are now using and others that have been tested but which are not class legal, most would say that this article is now well out of date. If you were serious about a proper discussion, you wouldn't use outdated information to try to support your views.

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Simon, Darios comments are not my view but an interesting take on UptiP foil design that has as much value now as when it was first written. It's value has nothing whatsoever to do with the A Class as much as it does uptip foil design.

It might be more productive if you posted something meaningful rather that just trying to knock everything you disagree with or don't understand as "Dougs view"-since you are so often very wrong.

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Doug

 

Your latest post from Dario's blog is now over a year old and is based on what are now old assumptions and old gear. At the time, he was correct but compared with the foils that we are now using and others that have been tested but which are not class legal, most would say that this article is now well out of date. If you were serious about a proper discussion, you wouldn't use outdated information to try to support your views.

 

And it is a clear breach of "netiquette" to re-post the complete content of someone else's blog post, instead of just enough to make a point, without their explicit permission - even when a link to the original is provided.

 

Here are some tips for reposting internet content with style and grace.

http://adammclane.com/2011/04/29/how-to-repost-a-blog-post-with-style-and-grace/

 

  • Never repost an entire article without permission from the site owner. First, its a breach of etiquette. Second, nabbing someone’s content without their consent is theft of their intellectual property. Third, even if you link back, most agree that search engines will punish both domains for duplicate content. [...]
  • Use an excerpt of no more than two paragraphs. Chose the part of the article that reasonated with you the most or makes the point most clearly, and excerpt it. You can wrap the excerpt in the context of a point you are writing about or simply post the excerpt with a question or thought for discussion. [...]
  • [...]

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Where is the Skat these days? I remember back in the day it was a big deal, then went away. May as well side track this thread with an honest question.

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Where is the Skat these days? I remember back in the day it was a big deal, then went away. May as well side track this thread with an honest question.

 

As I understand it, it was sold to the US Navy and shipped to them in pieces......

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As I understand it, it was sold to the US Navy and shipped to them in pieces......

 

 

Now we see how the original "it is supposed to be a People's Foiler" the Aerothud, was broken up into component elements and garaged, as well as given to a windsurf sailing school where it served as a trainer for rank beginners.

 

The difference, of course, is that Dr. Sam had the utmost in confidence in his design of the SCAT and your opinion of your own boat was that it was complete trash and didn't deserve to see the light of day any longer. Massive difference in intent, as well as fulfillment.

 

Now, we see you doing the very same thing to a star-crossed erstwhile foiler of your own design with the ever-so-snappily named, Fire Arrow. A boat that has all but disappeared into ignominy without a single sustained flight with fully controlled manners under sail. Basically, it amounts to nothing more than a jumping frog of a boat that can't foil stably to save its ass from the waiting cooking pot..

 

And therein lies the difference between yourself and Dr. Sam.

.

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Doug,

 

You can studiously ignore everyones comments as much as you like but the fact remains that 15 seconds of foiling falls a long way short of proof of your ideas, go ahead build more models, bombard the worlds forums with your

 

avalanches of rhetoric it changes nothing, many people have given you the time and space to prove your ideas and you haven't. Game Over.

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Simon, Darios comments are not my view but an interesting take on UptiP foil design that has as much value now as when it was first written. It's value has nothing whatsoever to do with the A Class as much as it does uptip foil design.

It might be more productive if you posted something meaningful rather that just trying to knock everything you disagree with or don't understand as "Dougs view"-since you are so often very wrong.

You quote an article that is about foiling on A's and you want us to take it out of that context and make out it applies to other things? Why does Dario keep referring back to A's in the post? He has done enough writing on uptip foils not to repeat stuff. You are simply taking things out of context, which you have a long history of doing.

 

I also note that there are a fair number of people on this tread pointing out how ridiculously you are behaving yet I am the only one you constantly attack. Does it really hurt you so much that I am fortunate enough to be right in the heart of what is going on and actually sail foilers? You hated it when i worked for Bladerider and spent so much time with Rohan Veal. You hated it that some of my close friends work for AC teams. You hate it now because I actually sail foiling cats.

 

There is one big difference between you and me. All I care about is what works best on the water and in particular at the moment, what makes an A Class fastest. As any racing sailor knows, that means you have to be totally open minded and try everything. I couldn't care less which ideas prove to be faster. I have no emotional attachment to any particular ideas. You seem to only care about proving that whatever idea is your current obsession is the best one at the expense of all other ideas. We saw it with CBTF, we saw it with your obsession about manual height control on Moths, and now we see it with up-tip foils. Once you have made your mind up, there is no going back. Not very scientific, is it?

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Simon, Darios comments are not my view but an interesting take on UptiP foil design that has as much value now as when it was first written. It's value has nothing whatsoever to do with the A Class as much as it does uptip foil design.

It might be more productive if you posted something meaningful rather that just trying to knock everything you disagree with or don't understand as "Dougs view"-since you are so often very wrong.

You quote an article that is about foiling on A's and you want us to take it out of that context and make out it applies to other things? Why does Dario keep referring back to A's in the post? He has done enough writing on uptip foils not to repeat stuff. You are simply taking things out of context, which you have a long history of doing.

 

I also note that there are a fair number of people on this tread pointing out how ridiculously you are behaving yet I am the only one you constantly attack. Does it really hurt you so much that I am fortunate enough to be right in the heart of what is going on and actually sail foilers? You hated it when i worked for Bladerider and spent so much time with Rohan Veal. You hated it that some of my close friends work for AC teams. You hate it now because I actually sail foiling cats.

 

There is one big difference between you and me. All I care about is what works best on the water and in particular at the moment, what makes an A Class fastest. As any racing sailor knows, that means you have to be totally open minded and try everything. I couldn't care less which ideas prove to be faster. I have no emotional attachment to any particular ideas. You seem to only care about proving that whatever idea is your current obsession is the best one at the expense of all other ideas. We saw it with CBTF, we saw it with your obsession about manual height control on Moths, and now we see it with up-tip foils. Once you have made your mind up, there is no going back. Not very scientific, is it?

 

 

Simon, you accuse me of attacking you which is you trying to cover your ass from a constant barrage of bullshit directed at me:

1) the post above had very important comments about UptiP foils that I thought might help "tinker sailor" understand more about those foils. Dario's quote was apropos to all uptip foils not just those considered for the A Cat.

2) you have a history of baseless personal attacks-not just directed at me, but at anyone who has the gall to disagree with you. If one does not agree with your interpretation of anything, it's time to duck because the Simon bullshit train will soon hit back.

3) your "criticism" of my test model and foil development work is incredibly pathetic without any "scientific" basis at all-just a compendium of nonsense reflecting your feeling that if I say it or do it it must be wrong. I have designed and continue to develop my own "automatic" UptiP foil that requires no adjustment whatsoever while sailing from low speed takeoff on up-and I have the pictures and video to prove it. This last video was the very first time the boat flew and everything regarding the foils worked perfectly especially the fact that the boat took off in a 5mph(4.34knot) wind. The two pictures below, "A" and "B" clearly show that the ama UptiP foil is maintaining the same altitude in two different load cases and at two different speeds. You simply can't get better than that-except to refine them while maintaining their high level of performance. That's what the test model program is about now that we've proved the foils.

 

Pictures illustrate that the ama UptiP foil maintains nearly the same altitude of the ama above the water in two different load and speed cases. "A" shows the lee ama flying with the main hull still seahugging, "B" shows the lee ama flying at the same altitude as "A" but with the main hull flying and moving much faster with significantly greater load on the lee ama:

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I have designed and continue to develop my own "automatic" UptiP foil that requires no adjustment whatsoever while sailing from low speed takeoff on up-and I have the pictures and video to prove it. This last video was the very first time the boat flew and everything regarding the foils worked perfectly especially the fact that the boat took off in a 5mph(4.34knot) wind. The two pictures below, "A" and "B" clearly show that the ama UptiP foil is maintaining the same altitude in two different load cases and at two different speeds. You simply can't get better than that-except to refine them while maintaining their high level of performance. That's what the test model program is about now that we've proved the foils.

 

Doug

 

Let's get one thing clear, forgetting everything else, and it is something that others have pointed out above. By your own admission, your model foiled for about 15 seconds. You are the only person I have ever come across who would consider 15 seconds of what everybody else sees as being uncontrolled and irregular flight proves anything. You claim that the foils worked perfectly, yet your video shows constant lurching and uncontrolled foiling. This is not just my view, but also the view of others who have posted above. You are delusional if you think that anything on the videos you have posted proves anything or shows controlled, stable flight. And in the video you posted with more wind, the boat is completely out of control, either trying to submarine or it is leaping out of the water. So stop coming all high and mighty as if you have developed something that works and which stands along side the work of people who really have produced foilers.

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Simon, you don't know what you're talking about-just more uninformed nonsense.

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Get that POV camera yet?

 

I'm in for $50.

 

 

Kinda hurt that you don't even acknowledge the assistance that many here could offer. I'm sure there's an SA er nearby who would help you get the boat out if you're physically incapable. Which actually would explain a lot...

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Remember in high school watching two chick fight? If not, go to youtube for chick fights. It's entertaining, exciting, hot, interesting albeit short lived. For some strange reason, it sticks with you for a long time in a way that puts a smile on your face in a sort of guilty pleasure way.

 

This thread has turned into the extreme and absolute opposite of that. Doug, please put yourself in a time out. You really need to step away from the keyboard. It's even lost its train wreck appeal......

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A bit more on surface piercing T-foils. I was inspired a few years ago by design work done by Mal(au) on the concept of a surface piercing T-foil for a Laser(see pix below). I also designed a combination surface piercing and "normal" foil that worked well with manual flap control in combination with the surface piercing elements when tested on a 16' hull.

Since I got into trying to help build a radio controlled AC cat, I've given a lot of thought to how to design a very simple foil system that would make it easier to get more RC boats in the air.

The idea for the Batfoils actually came from a foil I conceived of that could eliminate the main wand controlled foil on the Fire Arrow. It is basically a refined version of Mal's original idea combined with an iFlap(see earlier) on each tip to allow virtually automatic performance throughout the speed range starting at very low speed.

After talking with Alan Smith about canted T-foils I became convinced that some of the drawbacks with T-foils could be remedied by canting them. That was particularly true with the Batfoils, where a 4 degree angle of heel of the whole boat allows the windward main foil to fly saving on the electronics and weight of a retractable system on a model. These foils are about to be tested on the D4Z cat and ,though very,very experimental I think they have a good chance of working. They may have applications on some fullsize boats as well as on models, as a simple flying system, IF they work:

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You know, Razor, I think that's a good strategy; the "hey, do you need any help getting your shit together?", thing.

 

I just booked an architectural photo shoot in Boca Raton two weeks from now. I need to rent a car, anyway.... so why not just skip on up the coast a bit to Cocoa Beach and help Douglas get his fab tri in the water and being tested thoroughly?

 

What do you say, Doug?.... need any experienced help toting, launching, shooting video and most of all, documenting while you get this wonderful boat working in serious style?

.

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....Foil system both the main wand controlled foil and the UptiP ama foils worked 100% perfectly.

 

screenshot20140701at8.png

 

***R.T.***

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If I have read this right........(I know that we are relying on the word "IF" here, in the same way that DL "thinks" he has designed a really good system IF it works)

 

45 seconds of foiling in 7 mins, the equivalent to 10.7% of total time airborne.

 

Now I know that there are "lies, damned lies and statistics" and that not all foilers will spend a large proportion of their time in flight, but consider that the supplied video is already heavily representative of the best bits; after all it is designed to wow us all, by first the cameraman and later by the editing of total footage into a highlights package.

 

So the data is already highly skewed into broadcasting only the juicy bits - which in themselves is only 10% of flight.

So in my humble opinion - not very juicy........

 

And the point to all of this - DL talks about his systems working perfectly, and 100% successfully, etc. etc.

 

The evidence - as supplied by the claimant - shows otherwise.

 

If, (I know, I know - got to stop using that word) the evidence was supplied by a completely independent & unbiased source - then it would be even less flattering.

 

I am just going to hop, hop, hop along.

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Long version of the First Full Foiling Video of the Fire Arrow last year on July 24th--no editing:

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Yaaaaaawwwwwnnnn....

 

How boring. I never thought I would need to say this, but.... this thing has turned out to be every bit as tedious as the monotonous monologue surrounding the Aerothud, which was Doug's previous boat that also never foiled successfully. Page after page of the same nonsensical ranting with the same pictures that said nothing.

 

Gotta love the guy for his dedication to his Jones, though. At least he has nurtured an ineffectual style and is sticking to it.

 

It's right around this time in the scheme, that Doug is due to start another thread in which he suggests that he wants to talk about some kind of foil thing (what did you really expect?) and instead, he will, once again, turn it into a gum flapping exercise about his own junk, as if the merest business of standing next to a truly operational program will somehow magically will Doug's dream schemes into the air and in control.

 

There is a place in time for all of us, Doug, when we simply have to come to grips with the fact that our wildest dreams are most likely not going to come to fruition. We need to gracefully back away from the folly and move on to other areas in which we do have the requisite tools and capacity to achieve our brand of success. I think you are well past that point in this very public display of self-immolation.

 

Please be kind to yourself and the nice folks here on these pages and let go of the gurgling noise in your head regarding foiling boats of your own design. Put down the Exacto knife, the sandpaper, the clever graphics and nutsy phraseology, the whole mess.... and get into something where you really have a shot at blinding success. I think your psyche needs it and we could use the break, as well.

 

What d'ya say, Doug?

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For anybody wanting to learn more about the development of UptiP foils, see "Foils That Shaped the America's Cup", Part One by Pete Melvin and Part Two by Gino Morrelli here: http://www.cupinfo.com/en/featuresindex.php

 

First use of an UptiP foil on any size trimaran-June, 2014 :

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Doug, riddle me this.

 

Why 11 freaking months between sails?

I mean, this thing is supposed to change the future of sailing right? I can't wait 11 damn months.

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It';s interesting that Doug focuses on up-tip foils on his tri when others are using different solutions and getting rather good results.

http://www.catsailingnews.com/2015/04/40-mini-foiling-tris.html

 

There are videos of 4' model tri's sailing in a lot of wind and foiling pretty well, with a recorded top speed of over 15 knots.

 

These rc's are using 2 surface piercing foils, which seem to me to be a very good and well proven solution to foiling multihulls. It is, effectively, what we are using in the A Class, but with 2 rudders because we have cats not tris.

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