Foiler Design

Though I'm still thinking about the idea if the little wands weren't swept back they'd catch weeds I would think. The bent "planing" Rave wands don't look like they would but of course the vertical fins and hydrofoil would I guess.... I really like the basic concept....

[MalSmith]

Originally Posted by Kiteship

Hmmm, you've a good point, but it works the other way when the (or both) wands are submerged (presuming an upper and a lower wand): When the flap deflects upwards, one wand is "laying down" and the other is "standing up," creating a positive feedback. Once the upper wand breaks the surface, this feedback reverses... hmmm, is this maybe the reason we're not seeing this setup on boats?

Dave

The upper wand being raked forward would not matter as long as you limited the flap rotation, since while the upper wand is submerged, you want the flap to remain at the maximum (opimum) angle of deflection. I tend to favor the idea of using a reflexed flap instead of a lower wand for robustness. A system using a raked forward upper wand is not much different in principle to the trifoiler method, but may be more compact and less draggy when not up on foils.

Mal.

[perfusser]

Hi Guys, Ive been watching this thread with some interest, and have just joined the site as amember (woohoo). anyway I have had some of my own ideas on a foil design which i thought may be of interest, (please be kind with your responses, im sensitive lol). I remember a comparison between shark fins and foils in context of the tip vortexs they produce, which apparently the shark has overcome by having a flexible (cartiledge) fin. would having a flexible rather than stiff foil produce desired lift, and at same time depower automatically in lifting situation, similiar to a flexi mast does in gusts?

[perfusser]

just an after thought, i saw a foil with a shark fin styling that i thought was very pleasing to the eye(cant remember the name prolly too intoxicated), but was wondering if the mast rig and foil would be able to follow similiar radius, ie the tip of the mast to the base of the mast curve would continue under the boat through to the tip of the foil?
cheers bigears

[Stephen Ditmore]

For an article on the I-Moth Europeans see http://www.yachtsandyachting.com/def...&article=13990

I'd like to see a couple of U.S foilers travel to Europe and Australia, even if it means writing some letters to seek funding. Here on the East Coast the leading "Modern Moth" sailor and advocate is Scott Sandell, whose e-mail address appears at http://www.mothboat.com/. Doug Lord lives between an active (Classic) Moth fleet on Tampa Bay and hydrofoil designer Sam Bradfield, who has taught courses at Florida Institute of Technology off and on. But I'd be especially enthusiastic about Tom Speer teaming up with I-14 designer Paul Bieker in Washington State. Any chance, Tom?

Adam May said words to that effect at the Moth Europeans where there were some very close races between Moth foilers.The foilers could do four laps of the course to the "normal" boats three!
As far as I know there are no US Moth foilers(yet) but there are at least two monohull foilers(monofoilers) under development. There are at least two European I14's being converted to John Ilett's two foil/wand system..
There are some interesting comments on Sailing Anarchy under this same topic- one by Andy Pattison a pioneer of Moth foiing.
Another comment I particularly liked was that based on performance reports "the hype[about foils] is understated!"

See: http://www.monofoiler.com under "other foilers"for great pix of foiler Moths and an I14 flying an asy spin while on foils

[Jon Howes]

A very interesting comment. A glider built by Gunther Rochelt in Germany a few years ago for a competition to glide across the Elbe at Ulm employed a flexible trailing edge made of a series of hinged flaps. He did this to replicate the planform of the primitive glider that he was trying to emulate under the terms of the contest, the idea being not to screw up the perfomance of the modern aerofoil section that he used. He (and most of the aeronautical community who noticed) was very surprised to find that this trailing edge became load bearing due to induced aerodynamic moments on the flaps, this made the wing conformable over a wide speed range and appeared to significantly reduce the induced drag. This seems to be common in nature, the advantage it appears to confer is low drag over a wide range of lift coefficients although it is unlikely to result in an improvement to a wing optimised for a single lift coefficient so we won't be seing it on transport aircraft any time soon. A right toughie to design.

Originally Posted by perfusser

Hi Guys, Ive been watching this thread with some interest, and have just joined the site as amember (woohoo). anyway I have had some of my own ideas on a foil design which i thought may be of interest, (please be kind with your responses, im sensitive lol). I remember a comparison between shark fins and foils in context of the tip vortexs they produce, which apparently the shark has overcome by having a flexible (cartiledge) fin. would having a flexible rather than stiff foil produce desired lift, and at same time depower automatically in lifting situation, similiar to a flexi mast does in gusts?

[National3434]

Action shots from the Moth Europeans can be found at http://www.oceanimages.co.uk/gallery...s-July%202004/
and http://fotoboat.thirdlight.com//index.tlx . Look for the guy sitting patiently on a capsized wooden moth. That is me! I was waiting for a tow having broken the rack support block joint (by standing on the rack when inverted). I sailed three races in the end but in non foiling mode. The foils are still in work but at least it gave me a chance to learn to sail the boat.

The foilers really are as fast as people are saying. And the non-foiling moths are really very fast and skillfully sailed, with the kind of 'speed for size' you notice in a catamaran. the two Aussie boats were bought by good UK Moth sailers so there are now 5 in the UK fleet. Linton Jenkins at Full Force Boats is ready to go into production. see http://fp.lintonj.f9.co.uk/.
Cheers

[tspeer]

Originally Posted by Stephen Ditmore

...I'd like to see a couple of U.S foilers travel to Europe and Australia, even if it means writing some letters to seek funding. ...But I'd be especially enthusiastic about Tom Speer teaming up with I-14 designer Paul Bieker in Washington State. Any chance, Tom?

I'd love to! Paul Bieker has always been #1 on my list of consultants for when I get far enough along in the design of my cruising foiler (although that project is languishing at the moment). I've always planned to go to him for the structural design, but I've a lot more homework to do on the hydrodynamics and seakeeping dynamics first, plus decide if I'll ever be able to afford the building stage.

A third guy I'd like to get involved would be David Lednicer of Analytical Methods. Unfortunately these guys are busy with work and family, and I doubt any dinghy sailor can afford to hire them professionally. But, hey, it's worth asking - one never knows!

[In the small-world department, Paul Bieker's power boat (a converted Ultimate 30 hull) occupies the parking place right next to my F-24 in the Shilshole dry storage lot! It's looking mighty nice in its new sea-foam green color scheme.]

[John ilett]

The foilers really are as fast as people are saying. And the non-foiling moths are really very fast and skillfully sailed, with the kind of 'speed for size' you notice in a catamaran. the two Aussie boats were bought by good UK Moth sailers so there are now 5 in the UK fleet. Linton Jenkins at Full Force Boats is ready to go into production.

But of course the top boats 1st, 2nd, 3rd and 5th were all using Fastacraft hydrofoils, Lintons foils are yet to be developed and proven structurally sound. www.fastacraft.com

I went to the Linton UK website and clicked on "Foils" and was surprised to see a picture of John Iletts foiler! I can't believe that a new company would advertise it's foils and foiler using a picture of the competition's boat??!!
Fastacraft is THE Moth foiler pioneer builder with an impressive record-using that image in that way isn't right...

[NiklasL]

Cheers all foiler enthusiasts!

Does anyone know how John Ilett's "Dancer" project is going? Has he reached any topspeeds, Maby he's been sailing ever since his last web update..

for anyone not aware of this boat, please visit: http://www.monofoiler.com/

/Nikelodeon

[TaSSie_deVil]

Originally Posted by NiklasL

Cheers all foiler enthusiasts!

Does anyone know how John Ilett's "Dancer" project is going? Has he reached any topspeeds, Maby he's been sailing ever since his last web update..

for anyone not aware of this boat, please visit: http://www.monofoiler.com/

/Nikelodeon

I get the feeling that Doug Lord sold it shortly after putting it on the water for it's maiden voyage, and little has been heard of it since, which is sad in ways, and great in others (face it... it was never going to be a pretty piece of machinery!)

On the note of the "Mistress" (UK design by linton jenkins) moth foiler using photos of other developments (like the Prowler) on its website is nothing to worry about. Happens all the time. From the results of the European Championships, the foils seem to be providing a fairly level playing field, regardless of the design of the foils or who makes them. Both of the designs work on the same principals, namely the wand on the bow, and adjust the centrefoil roughly the same, so it's all a bit like laser racing (albeit a metre or so above the surface of the water and at a rediculously high speed...) in them now, it's the difference between the sailors that decides the finishing order.

"face it it was never going to be a pretty piece of machinery" Oh? A number of people have sent me e-mails with the exact opposite sentiment! You're out voted!
The boat is not sold but because of time constraints I have not yet flown the thing. There are some small nitpicking problems to be corrected but generally I believe the boat will foil and be fairly fast. Time will tell.
The aeroSKIFF™ is the prototype for a two person monofoiler designed to be able to be sailed off of inland/intercoastal beaches. In the first series of tests in light air it sailed very well as a sailboat. I expect the same results as a foiler.
As a foiler this boat (and foils) are designed to be able to jump for the hell of it: The skipper will be able to overide the wand and /or use manual control to physically cause the boat to jump clear of the water and safely re-enter. At least thats the plan. I believe it's possible and could be a lot of fun....
The foils were supplied by John Ilett, the premier Moth foiler builder, and I couldn't be happier with them. I hope to be able to spend serious time on it in 2005 or to make a deal with someone else to finish her testing.
And whether it is my boat or not I can't wait for a high performance easy to sail two person monofoiler to hit the market!

I differ with Tasie(?) on the use by Linton of an image of John Iletts boat on his website to advertise his foils. Foils DO make a difference: Jon Iletts foils in the Moth Europeans got 1st,2nd,3rd,and 5th. Lintons got 7th..
But it's really the princible of the thing: all these guys are trying to make a name for themselves but even though Linton does give credit for the picture I still think it's tacky to use someone elses boat and foils to draw attention to yours..