MWsails said..

Chris 249 said..

Simon100 said..


Picture fixed / changed amazing that now the air flow is clean and enters the foil smoothly at the front.
Its a more realistic representation of a modern sail but at that angle of attack i would imagine would be getting some separation on the low pressure side.

Your all just posting pictures of stuff that is totally made up no one has defined the conditions under which the sail will operate every picture just has a random profile to prove whatever they want . I can draw a picture of a windsurfer in the moon landing sail blowing the breeze, doesn't mean it's true or relevant .
Does anyone know the answers to these questions i think the must be answered before any technical argument can be made.

What is typical wind gradient between 0 and 5m at 1 m intervals at 15/20/25 knots , (this would be important) ?
What is the typical windspeed / board speed ratio at various angles across wind/ 30 degrees off/ 30 degrees up (obviously needed to determine apparent wind angle and combined with gradient to calculate the twist) ?
What is the angle of attack of a windsurfer sail at various points of sail ? (what foil shape do we even need, when combined with everything else )
How much lateral force can be applied to the sail by the sailor ? ( is a shorter sail faster because the rider can hold more force even though it will obviously have a lower l/d ratio or is the taller one faster because of a lower l/d , no point making a sail that simulates well as a plane wing when the conditions are different here .)

I have no measurements for these i could have a guess but if anyone and offcourse all those numbers could be mashed together in various ways to work out lots of things and would be the basis of any technical argument based on drawings graphs and quotes. If i was to make a sail i would establish these first. Of course there is a lot of people making great sails with experience and knowledge probably not doing this.
Realistically though if we want to see how well an existing product works the results are all that matters even if we don't know why it works its unimportant as long as we get the results we want.

Well said.

Tim Gourlay's paper (linked to earlier) seems to make a good stab at some of the issues you highlighted, but your questions show how complex sail aerodynamics are.

Chris you didn't answer , why do you need sail change every 6 kt? And please put a lot of science behind it .

I don't need a sail change every 6 knots. Like many people, I race boards that only allow either one or two sails to cover from zero to 30 knots or more. Even when I did slalom racing to world championship level many years ago, I only had three sails (just two at the worlds because of transport problems). So there's some practical experience that proves that many, many windsurfer don't change sails every 6 knots.

I sail a lot in gusty locations where people don't change sail every 6 knots. They just keep on sailing if the wind changes from 12 to 22 knots. Even companies like Loft Sails say that if you only want to sail in 18 knots you can get by with two sails. (www.loftsails.com/en/blog/tips-for-building-a-windsurfing-sail-quiver)

Other people may change sails every 6 knots for reasons that include the C of E moving aft, excess heeling moment/root moment, optimum aspect ratio/planform, excessive vertical lift caused by rake (which wants to make the board lift off) and optimum draft - and even marketing. Of those aspects, a wingsail may well be better at handling a wide range of angles of attack, as I have admitted regularly. But being able to adjust AofA and therefore power is only one factor.

In windsurfing most of us like to keep our hips aligned with the centreline of the sail, and our arms at roughly the same extension. If we are adjusting the sail's angle of attack without changing board direction, we end up with our hips out of alignment or one arm pulled in closer. Many people don't like that (and the twisting force it creates in the body) so they cannot use the claimed advantage of a wider angle of attack.

Finally and as an analogy, look at yachts - they have zero problems adjusting AofA because they can just ease the sheets, traveller or inhaul. And yet many yachts change jibs and spinnakers for every 6-10 knots of wind, because each of their sails are optimised in terms of twist, amount and depth of camber, sail cloth weight, aspect ratio etc. So there are many reasons to change sails that have nothing to do with the ability to change the angle of attack or "getting backhanded".

MWsails said..

gorgesailor said..

MWsails said..
Ok Chriss, may be you can explain others why do they need change sail every 6 kt wind increase?

Just FYI ....They really don't. Maybe in the 80's we did but not now. Even with 3 batten wave sails.

I am in contact with racers who participate this year in PWA and luderitz . They say that they choose sail in 6 kt range. Also in real life on the beach we can see same. I dont know what you trying accomplish here , but your lies too primitive. Please come up with better stuff.

Umm what lie? I am not trying to accomplish anything except to inform you that this is not the case, for your own information. This SHOULD inform your marketing approach. I meant that I would never change sail every 6knot anymore. Modern sails have much more range than 6 knots.

Maybe Stan you think you are "winning people over" to your ideas. Really what has happened is an obviously interesting, well made, better at something product is being oversold by a terribly unskilled marketer. Sad.

Sailquick, don't you come on here with sense and reason, it's not the place for it.

sailquik said..

gorgesailor said..
Just FYI ....They really don't. Maybe in the 80's we did but not now. Even with 3 batten wave sails.

Agree. For winds 14 to 25 knots, when freeriding, I hardly change sizes at all. Sometimes I would change the board, but stick with the same 6.2m or 6.6m Cambered freerace sail. I would probably even do the same thing with a non cambered freeride sail.

But I do change sails when speedsailing when the wind increases from 35 to 40 knots! Thats only 5 knots difference but a WHOLE lot of Force difference compared with an increase from 20-25 knots! But these Wingsails are not claiming to be Speed sails anyway, are they?

If I were racing, like slalom type racing, I would change sails every 5 or 6 knots, if the wind was pretty steady, and if I have the choice, just because I want to optimise my speed, and speed to comfort ratio that impacts race course succes for me. But then these Wingsails are not claiming to be Race sails anyway, are they?

When wave sailing, if the average wind was steady and changed 6 knots from 18 to 24 knots I would definitely change sails. I probably would not absolutely have to, but, what the hell, wave sails are relitively inexpensive so I have a few, and I would enjoy it much more. But then Wingsails are not claiming to be wave sails anyway, are they?

If a sail is more efficient, more stable and more controllable, it only makes sense that it would be faster. Thats why I want to try one of these myself for speed sailing and GPS racing.

If you are going to use experience, reason and logic in your arguments, that makes you a wise man of science, and therefore I'll have you banned from this thread, as wise elders giving sage advice dont belong here, this is your second warning, 3 strikes and your out!!!!

MWsails said..

Sparky said..
Maybe Stan you think you are "winning people over" to your ideas. Really what has happened is an obviously interesting, well made, better at something product is being oversold by a terribly unskilled marketer. Sad.

Why do you think Im trying to win you over? What is next? A dimond ring?

Why did you bother making the sails? Why did you set up a website? Why are you selling the sails? Why are you telling everyone about the sails on a few different forums? To "PROMOTE" them.
Yes, a diamond ring would be nice, try some sweet talking, listen, agree occasionally, woo us with pleasantries and we will find your products so attractive we will want to spend some time together.

Sparky said..

MWsails said..

Sparky said..
Maybe Stan you think you are "winning people over" to your ideas. Really what has happened is an obviously interesting, well made, better at something product is being oversold by a terribly unskilled marketer. Sad.

Why do you think Im trying to win you over? What is next? A dimond ring?

Why did you bother making the sails? Why did you set up a website? Why are you selling the sails? Why are you telling everyone about the sails on a few different forums? To "PROMOTE" them.
Yes, a diamond ring would be nice, try some sweet talking, listen, agree occasionally, woo us with pleasantries and we will find your products so attractive we will want to spend some time together.

All right, I can do some sweet talking as you request ..... and agree on some issues OK. But don't get any ideas.

Seabreeze forums are not necessarily the best way to market new developments. Infact the attitude of many posters here is aggressive and also cynical. The best way is proof in competition. If your competitors adopt it as well then it obviously works. You need to have your gear used by good and credible riders and in that way people believe in and then can trust your message.

Mark _australia said..
MW still not understanding the definition of "proof"

I reckon am a way better sailor than all the PWA guys. You will all believe me without me actually showing anything, won't you?

I have hit 60kn on my speed gear, I'm sure I have.

The thing that magnetises the fuel in my car so the molecules line up and flow better is so good, it is only eclipsed by the thing that spins the air prior to induction.

I have a bridge for sale BTW........

It's strange, isn't it. If someone who had never proven their sailing ability said they were better than all the PWA star sailors, people would call them a wanker - quite rightly. But when someone who has never proven their sailmaking ability says they were better than all the PWA star sailmakers, they expect everyone to believe them and not to tell them they are being cocky.

It's an odd thing.

MWsails said..

NCUSAGUY said..
All major sail manufacturers have a variety/line of sails for different purposes. Wave; freeride; bump and jump; freestyle; kids/beginner and race (slalom, formula and speed). In each category, there are a number of sails for various conditions (wave sail wind directions) or cost points for novices, intermediates and experts. This has nothing to do with wind speeds / range of use.

The challenge/difficulty for the wingsail is that even if it is the best at what it does, and we are not sure exactly what that may be just yet, its target market is somewhat limited by what it can do and its price point. If it does have a broad wind range, the cost may be justified since the sailor may not need as many sails, but wave, freestyle and race sailors will likely NOT be too interested.

I have wave, freeride and race sails and they each have their pros and cons. Each works well for the discipline that it was designed for, but cross over to another discipline has it downside, some great, some not so much.

For example, my race sails are very stable in a broader wind range than my other sails, but they are heavy & don't luff well = more difficult to jibe, water start, uphaul, or even carry to the water. For racing, the pros outweigh the negatives, for freeriding, the negatives outweigh the pros.

For the wingsail, all of these issues will be a challenge, but innovation is always good, but no always successful.

You probably misunderstand something. Thouse issues has been solved wth wing. Waterstart , easy jybe, wind range, and speed.

No, I think you misunderstood my point. I don't see your sail being of interest for wave, freestyle, kids/beginners and some racers. So your market is mostly freeriding and possibly some racing (speed/slalom racing to be determined). Few if any sail manufactures design for only one discipline, likely because the market potential is so small. I see it as a challenge for you that will be hard to overcome, unless your strategy is to sell the patent/design if it proves to be all that you claim.

Those like you that have new, potentially exciting ideas always face marketing, production and distribution obstacles. It's tough to overcome them, so I wish you good luck.

NCUSAGUY said..

MWsails said..

NCUSAGUY said..
All major sail manufacturers have a variety/line of sails for different purposes. Wave; freeride; bump and jump; freestyle; kids/beginner and race (slalom, formula and speed). In each category, there are a number of sails for various conditions (wave sail wind directions) or cost points for novices, intermediates and experts. This has nothing to do with wind speeds / range of use.

The challenge/difficulty for the wingsail is that even if it is the best at what it does, and we are not sure exactly what that may be just yet, its target market is somewhat limited by what it can do and its price point. If it does have a broad wind range, the cost may be justified since the sailor may not need as many sails, but wave, freestyle and race sailors will likely NOT be too interested.

I have wave, freeride and race sails and they each have their pros and cons. Each works well for the discipline that it was designed for, but cross over to another discipline has it downside, some great, some not so much.

For example, my race sails are very stable in a broader wind range than my other sails, but they are heavy & don't luff well = more difficult to jibe, water start, uphaul, or even carry to the water. For racing, the pros outweigh the negatives, for freeriding, the negatives outweigh the pros.

For the wingsail, all of these issues will be a challenge, but innovation is always good, but no always successful.

You probably misunderstand something. Thouse issues has been solved wth wing. Waterstart , easy jybe, wind range, and speed.

No, I think you misunderstood my point. I don't see your sail being of interest for wave, freestyle, kids/beginners and some racers. So your market is mostly freeriding and possibly some racing (speed/slalom racing to be determined). Few if any sail manufactures design for only one discipline, likely because the market potential is so small. I see it as a challenge for you that will be hard to overcome, unless your strategy is to sell the patent/design if it proves to be all that you claim.

Those like you that have new, potentially exciting ideas always face marketing, production and distribution obstacles. It's tough to overcome them, so I wish you good luck.

There is always obstacles. You're right. I don't expect it to be easy.

Amazing thread.

Keep on posting , this is a stunner.

Just love it!!!

Had to register at the forum just to be able to comment, could not help it

Need a beer , lots of work reading all of this......

Broken Fin said..
Amazing thread.

Keep on posting , this is a stunner.

Just love it!!!

Had to register at the forum just to be able to comment, could not help it

Need a beer , lots of work reading all of this......

Welcome to Forum broken fin ! Easy on beer, after this thread is done you might need to go to rehab

MWsails said..

Chris 249 said..

Mark _australia said..
MW still not understanding the definition of "proof"

I reckon am a way better sailor than all the PWA guys. You will all believe me without me actually showing anything, won't you?

I have hit 60kn on my speed gear, I'm sure I have.

The thing that magnetises the fuel in my car so the molecules line up and flow better is so good, it is only eclipsed by the thing that spins the air prior to induction.

I have a bridge for sale BTW........

It's strange, isn't it. If someone who had never proven their sailing ability said they were better than all the PWA star sailors, people would call them a wanker - quite rightly. But when someone who has never proven their sailmaking ability says they were better than all the PWA star sailmakers, they expect everyone to believe them and not to tell them they are being cocky.

It's an odd thing.

Did Koralev went to space? Did Boeing designers are best pilots? And Look at you, you are the champion of windsurfing and still promoting that rig from 1970 . Wingsail is not a new concept ,almost every company tried to develop it, It happens that I have enough knowledge ,skill, funds and patience to execute it properly . I don't have to be a champion to make rig for the champions.

You missed the point. The issue is that you are claiming to be better than all the other sailmakers, without proving it. It's just as if someone was claiming to be better than all the other windsurfers, without proving it. People would laugh and jeer at someone who insulted AA like you insult the top sailmakers, unless they had proven they were better.

Of course, we don't really see any great sailor insulting the best sailors like you insult the best sailmakers. The great sailors and sailmakers don't disrespect other sailors and designers like you do - they respect them and learn from them, not call them "foolish" and their designs "primitive". Bjorn didn't disrespect Robby, for example - he respected him enormously and learned from him.

If respecting others is good enough for the world's best sailors and sailmakers then it should be good enough for the rest of us.What you are doing is like someone inventing a new chair and claiming that all you furniture manufacturers came to "foolish conclusions" and made "primitive" chairs. Unless and until they proved they were right, they'd just be a blowhard.

And every good sailmaker I know of is a damn good sailor. If people are not very good sailors it's normally because they don't have a good intuitive understanding of what really matters in sailing and in sails. The lack of understanding Is not only caused by them being mediocre - it's often a cause of their mediocrity. An intermediate sailor often blames their gear, when the real problem is poor technique.

I promote a rig from 1970 for some things, because it's very good in some ways. In other ways and for other uses, it's terrible. Just about every sail has its good points and its bad points, like good span loading, or light weight, or low heeling moment, or high lift at the expense of very high drag. I own four wingmasts and they are great in some respects, bad in others. I own a bunch of conventional masts and soft sails and they are great in some respects, bad in others.

Claiming that any sail is "100% better in all respects" is just plain silly, especially when your own website shows that you sail has lower lift in some situations and therefore according to your own PR it is NOT "100% better in all respects". It's like saying that one wing shape is better in all respects in a plane.

For you to call someone a liar because they say they only use three sails, like you did here, is just bizarre. Plenty of us have three sail quivers and although you ignore it, plenty of racers only have one sail to cover from zero to 25+ knots and they do it well.

Laws of Strategic Marketing by Stevens et al ="You cannot denigrate your competitors' products or services"

books.google.com.au/books?id=_QnfAQAAQBAJ&pg=PT202&lpg=PT202&dq=problems+with+denigrating+competoitors+when+marketing+your+product&source=bl&ots=B9rG_EHKdW&sig=3hhk-rpHdvscy717rC7nJqXeF5E&hl=en&sa=X&ved=0ahUKEwiugPb_0o_YAhXGx7wKHVPNBqcQ6AEIKzAA#v=onepage&q=problems%20with%20denigrating%20competoitors%20when%20marketing%20your%20product&f=false