KissCut-new Swiss Foiler

Here is a google translation of the page: http://translate.google.com/translate?prev...history_state0=
LOA 4.5 m=14.7'
Beam 4.5m=14.7'
SA=9sq.m=97 sq.ft
weight est.=40kg=88lb.
Price-an amazing(!) $42,000US no peoples foiler if this price is accurate


the untranslated article: http://www.skippers.ch/record-et-proto/art...;sousCategorie=

renderings from Vincent Gillioz article:

 

Wow, and I thought I could build light! Is that the fully-rigged weight or just the hull weight? If that's ready-to-sail there is some serious technology in that boat.

However, it seems to be just a design on file. It was supposed to be announced in April if my French is up to the task; I can't find any recent mention of it though.

I like the amas, nice safety feture, but it's hardly a people's foiler at any price. I think the peoples foiler will have to be much easier to sail, probably with angled foils and passive stability even if there is a speed penalty.

Thanks Doug for researching all these foiler sites, keeps us informed.

 

If 42K USD is affordable for a single hander, I wish I worked in the Swiss economy.

They started by saying the Moth was too athletic to sail and Mirabaud required assembling a team to sail. They quickly proposed their design as easier to sail and able to touch & go as a result of the amas.

I looked briefly around for evidence it was ever built and didn't find a trace either.

This type of unobtainium cubic dollar approach to foiling is diametrically opposed to the formula I believe necessary - cheap as dirt is the road I think is needed.

The Moth is still too expensive for a limited use fun toy. Face it, foiling isn't a legitimate sailing activity for all conditions. It is an activity that has a window of conditions that are fun, and outside that window it is either painfully impossible (light to no winds) or dangerous (high winds and equipment failure). Failure of either equipment or loss of wind basically demands that motorized support should be available for foiling venues. These boats do not paddle well (if at all), and broken parts render them fundamentally flotsam.

Because of this reality, I think foiling needs to be affordable enough that people can have their foiler as a second boat for use in the right conditions - much like kiteboarding or Formula board sailing. Even board sailors make sure conditions are okay before bothering to leave shore.

What would be the minimum price necessary to create a low cost foiler? Understanding concessions must be made to hit the price target. I don't think the Moth's demand on athleticism are outrageous, so use that as a base line for crew competency.

Real volumes may be possible if a low cost entry could be sold for prices similar to a Laser. 6K US is a fair estimate. Does this work?

--
Bill

 

"The Moth is still too expensive for a limited use fun toy. Face it, foiling isn't a legitimate sailing activity for all conditions. It is an activity that has a window of conditions that are fun, and outside that window it is either painfully impossible (light to no winds) or dangerous (high winds and equipment failure). Failure of either equipment or loss of wind basically demands that motorized support should be available for foiling venues. These boats do not paddle well (if at all), and broken parts render them fundamentally flotsam."
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It is simply not accurate to paint all foilers with the Moth brush-there is no reason that a monofoiler can't be rugged enough for use as a primary boat or that it has to be limited to certain conditions. Ideas are already in use that allow the RS600FF to be sailed in a wide range of conditions with it's reefable rig. It is far easier to launch than a Moth with it's wider hull and retractable daggerboard and rudder.
If you combine some of those features with the wider beam of the Swiss boat and substantial buoyancy pods/amas you have a boat that will be far easier to sail than a Moth and sailable in a wide range of conditions. Amac(designer of the Bladerider and Mach II) has said that the Moth would foil in 5 knots of wind with 4sq.ft more SA-it already foils before a windsurfer planes. A new boat could be designed to foil in the lightest wind and with a reefable rig and more beam could be as manageable as any other dinghy in strong conditions.
Since the inception of wand controlled bi-foilers in 1999 the development effort has been to make a fast bi-foiler-now more and more people are looking at ways-outside of the restrictions of the Moth(or any other class)rules to make an easy to sail bi-foiler.Jon Howes and Linton Jenkins have pioneered a new kind of foil that does not require a wand and could offer many advantages. Before a Peoples Foiler can be done preconceived ideas such as those above will have to be understood as not representative of all bi-foilers-but just the Moth.
Bladerider has already addressed the cost issue by developing an all glass Moth that weighs just a bit more than a carbon version. That kind of thinking applied to a bi-foiler designed from the get-go to be easy to sail in a wide range of conditions will eventually lead to a "Peoples Foiler".
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I'm convinced that the price quoted for the Swiss foiler is some sort of misprint-I'm working on getting more info.

 

Doug:

You have a bad habit of picking and assembling together arguments that are mutually exclusive to prove a point. There are some basic principles that just don't work well together anywhere but in your imagination.

Here are some of the issues and problems:

1) Generally, ultra low weight requires high cost exotic materials. Carbon, kevlar, epoxy and the like are expensive material choices that lower weight and maintain or increase strength.

2) Low drag means reduced wetted surface area and/or reduced form drag. Needle-like skinny designs have lower form drag and reduced wetted surface area at the penalty of stability and usability as a general boating platform. Wings necessary for righting moment in these designs have high aerodynamic drag.

3) Wider dinghy designs like the RS600 have higher form drag and higher wetted surface area when not foiling. They also have high windage and aerodynamic drag when foiling. These designs logically will foil later than low drag designs in marginal conditions.

4) Adding amas or as you call them "buoyancy pods" to an already wide bodied dinghy design like the RS600 will increase drag and lower potential performance more.

5) There is no magic wand allowing the addition of power without penalty. More power requires more righting moment. More righting moment means either the existing moving ballast (the operator) needs to move further from the centerline (increased moment arm) OR more weight is necessary if the moment arm length does not change. More weight equals less performance potential and more lift required to foil. More lift requirement means more drag.

My "low cost foiling" proposal was submitted to provoke thought on how one could achieve a basic foiler at the lowest possible cost, recognizing that every design is the sum of it's compromises to reach the designer's targets of price, performance, durability and value.

Returning to my original point, here are the conundrums:

1) Ultra low weight and strength generally requires exotic and expensive materials. Higher cost reduces the available buyer pool.

2) Safe and simple operation generally requires lowering the performance bar to add stability and simplicity.

3) Adding the design criteria of a "general purpose all condition sailboat" to the high performance foiling ability makes the design brief very broad. The broader the design brief, the more expensive and complex the solution.

I just can't see how you could come up with the magic formula for a People's Foiler - low/reasonable cost, simple and safe operation, high performance and usable as a general purpose sailing dinghy as well. Eliminate cost as a criteria and yes, it gets easier - hence the proposed Swiss foiler in this thread. They've made their choices and 42K USD is the price tag. Lowering the price tag means compromises which have major effects on the design brief. I highly doubt there is a huge profit margin in their price, given the low volumes and small buying pool at that price level. I disagree with you on the pricing - I do not think it is a mistake.

My idea was to fix the price target and then try to achieve the best possible result in the set price - reducing the design brief to fit the price. I'd like to see what is possible and how bad the compromises would be to fit the price.

To me, focusing on the critical components is required. Foils are the most critical component in a foiler. Everything else is less important. The #2 critical issue is the rig and it's efficiency and drag. The least important component is the hull.

I'm willing to bet quite a few of the homebuilt foilers out there were done at significantly lower cost than a Bladerider (even the glass/epoxy version). Once you move outside even a development class rule set, what could be possible?

--
Bill

 

Winds sufficient to fly a competition foiler are common enough, and "minimum foiling wind" don't tell us non-foilers an awful lot about what we would have to do to join the foiling ranks. I don't think the problem is one of power, no more power is needed to stay up on foils than to keep on planing, once the condition is achieved.

It is getting into these conditions that needs the power. Once speed starts to climb, and on certain points of sailing, the question of aerodynamic efficiency becomes an issue. But that's not needed just to have fun.

What would certainly "sell" would be a kit that could be added to an existing boat that would, conditions permitting, allow foiling. The foils could be retractable with a minimum of fuss, perhaps stored in the boat. It would be a sometime thing for most sailors, not worth a huge investment.

So what would be the minimum needed? let's assume we would like to add foils to a small boat like the Laser that's already capable of planing. Is the existing sail area and form suitable and what kind of foil area would be appropriate?

 

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If you want to take off in the same wind as a Moth
you need a W/SA of 2.558 or less. A hull with a l/b ratio of much less than 10/1 will require a ratio substantially less.

Here is an interesting comparision of the Moth, RS600FF and Mirabaud:

It is extremely important to note that the comparison of foilers of different weights WITHOUT considering POWER is inaccurate. Weight is CRITICAL when comparing the performance of two identical foilers but WEIGHT AND POWER must be considered together when comparing different boats.
All three boats have proven on the race course to be extremely close in speed.
======================
Moth-
SA: 86sq.ft
Sailing Weight(includes crew): 220lb.
main foil area: 1.19 sq. ft.
Foil Loading(Lbs per sq. ft. at 80% max boat weight with crew):147.89
W/SA: 2.558lb. per sq.ft.(sail loading)
SA per sq.ft. of main foil area(a SA/ws ratio shortened to cover planform area of main foil only): 74.62
=======================
For ease of comparison foil areas for the next two boats were arrived at by using the same FOIL LOADING as a Moth.
Only upwind SA is considered. Moth crew=154lb.RS crew=160lb.; Mirabaud crew =3X160lb.
=======================
RS600FF
SA: 131 sq. ft.
Sailing Weight(includes crew): 327lb.
main foil area: 1.76 sq.ft.
Foil Loading: 147.89 lb. per sq.ft.
W/SA: 2.49 lb. per sq.ft.
SA per sq. ft. main foil area: 74.43
======================
Mirabaud
SA: 354 sq.ft.
Sailing Weight(includes crew): 854lb
mainfoil area: 4.61 sq.ft.
Foil Loading: 147.89lb. per sq. ft.
W/SA: 2.41
SA per sq.ft. main foil area: 76.78+++++++++++++++++++++++++++++++++++++++
+++++++++++++++++++++++++++++++++++++++
Note the different weights of the boats . Then note the Sa/per sq.ft. main foil area-this is a comparison of Sail area to wetted surface when the boat is flying using just the planform area of the main foil for comparison-THEY ARE NEARLY THE SAME FOR ALL THREE BOATS. Note the W/SA is almost identical for all three boats. This means that all three boats will foil at about the same time adjusted for differences in rig efficiency(Moth probably the best) and for hull L/B ratio as a measure of early takeoff potential(Moth by far the best). As I just said there are other factors and details that will marginally affect performance but this clearly shows how close all three boats are in their ability to fly despite the fact that the RS is 2.5 times heavier than a Moth and Mirabaud is 5.6 times as heavy as a Moth.
What counts is power to weight ratio as a first look. A more detailed look showing a comparison of SA/ws ratios for all three boats reinforces the accuracy of the power to weight ratio.

 

Doug,

You know that it's been right around four years since you started mentioning this whole thing about People's Foilers? In that time, not one boat has emerged as a candidate with the right stuff to be able to meet anything even close to the established criteria. Even your own, homebuilt effort seems to have morphed several times into different animals and none of them have seen the water yet.

Now, the whole world is well into a very deep recession economically and the available disposable income, which was supposed to drive a push into a People's Foiler as a viable product, has virtually dried-up and blown away.

Yet, here we are, still fooling around with the concept as if it has some sort of real potential in the marketplace.

Some things, Doug, are just not in the cards as workable entities. Perhaps it's time to recognize the market realities of a People's Foiler and move on to other, more fruitful expressions? The sailing world craves simple, easily purchased and sailed craft with modern, aesthetic design appeal that will move more potential buyers/sailors onto the water. The sport is dwindling in size, even in the recent good years of economic well-being. In bad times, such as these, the sales figures are seriously depressing.

Perhaps a good deep think as to the real definition of what is suggested by the term, People's, is in order before prescribing a craft that is more expensive, more complex and more maintenance oriented than other, entry-level recreational boats, already on the market...?

 

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I think that you can start with a price but you have to be realistic-is $6,000 the retail price as sold by a dealer? But whether you start with a price as you want to or with a set of characteristics as I do at some point, very early on, you have to seriously look at the numbers to see what is actually required to meet the characteristics-or the price.

 

Speaking for myself, I would not want a pure foiler, something that would be uncomfortable, expensive and quickly go out of date. I am not pursuing records and I am not interested in competition.

Maybe I've just damned myself on the eyes of some in the forum. I like boats, I like experimenting and I want to sail. Foiling looks ans ounds like a blast and I would also like to give it a try. From this, you can see that I'm not really interested in a boat such as the moth which will leap onto its foils everytime someone on the bank sneezes. I can't see myself owning a boat that will foil in a 5k wind but I certainly can see myself safely and happily sailing in 10k wind. And wondering all the time "will she foil if ..."

I can put myself in a kayak or canoe for a total weight of 200 lb or so or I can consider my nearly finished small, stout sailboat at about 260 lb.

"If you want to take off in the same wind as a Moth you need a W/SA of 2.558 or less"

-OK that's a place to start. 85 sq ft on a kayak is a bit high, 100 on the sailboat is doable although a bit of a handful and probably not enough as she is a fattie. If I double the wind that quadruples the thrust: can I reduce the sail area proportionately? I understand there are other factors such as foil performance and hull drag to consider but I am just looking for a place to start at this point. Baby steps.

I am curious about the long narrow hull shapes that seem to be prevalent on foilers. I would have though a planing shape - wide/flat- would be a better choice. Is the consideration primarly one of weight or are there other causes and effects?

 

Very reasoned thinking, Terry. Small steps

Best you consult with experienced foiling guys like Gary Baigent who actually builds and sails the boats he loves.

Gary can get you on a planned discovery process and it won't involve many thousands of dollars to get there. Since you like to get stuff built in your shop, you'll be miles ahead of those who only spew.

If you come round to multihulls with trad, non-flying, foils... I'll be happy to help you with any questions you may have.

Whatever it is, make sure you have fun doing it.

 

Terry,If you want to takeoff in around 10 knots of wind you can use a rough W/SA of 3.14. If you want a foil that just reduces wetted surface ie, "foil assist" use the formula for lift to calculate a foil area and speed that will reduce the wetted surface of the boat by approximately four times the planform area of the foils. You might want to have to have Abbots and Doenhoffs or use X-foil(ask Tom) but I've given you CI's that I've found work in practice.
A&D gets you the CI(coeficient of Lift) and you could use the 63412 foil as a representative foil. The formula seems to be accurate for aspect ratio's of around 7/1. This is for horizontal t-foils; with angled foils you can probably calculate the total area of lift from the projected area of the foil but keep in mind that because of leeway the windward foil is operating at a lower CI than the leeward foil. You can estimate this for your purposes.
The formula:
S=L/[F X V squared X CI] where

S= Area of Foil in sq.ft.
L= Total weight in pounds
F= 2.09
V squared= Speed in mph squared
Cl= ideal for 63412 foil .3 to .6 which equates to zero degrees angle of attack to approx. + 2 degrees. A good initial set up would be +1.5 degrees + full flap(if used) or start at +2 degrees-no flap. For foil assist you don't need altitude control; same for angled foils. You'll need a wand or similar for fully submerged foils.
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You need to pay attention to L/B ratio or make sure that the planing hull you design is similar to the "humpless" Bethwaite skiffs. The RS600FF is an example of a planing hull dinghy that is also a high performance foiler-see the comparisons above.

 

Aside from the engineering difficulties, at that sort of price why would I go out and buy a (peoples)foiler when I could get set up with kite surfing kit and or wind surfing kit? For accessibility to an exciting wind powered water sport its hard to beat kite surfing at the moment, and its going to grow with course racing as well

 

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My personal opinion is that a Peoples Foiler has got to be able to perform well in light air(5 knots wind) with one or two people on board-with a reefable rig, retractable foils, etc. How much is that worth?

 

Where I live that would be worth very little, most sumer afternoons we get a 15kt plus sea breeze, which Im guessing would make something that foils in 5kts tricky to sail here. If I was going to make a peoples foiler it would look a bit like a Weta with Bruce foils and a T foil rudder......