John340 said..

MWsails said..

Mark _australia said..
^^^^ I think he means more people using it MW, and testing it side by side with other gear.

Your video I saw is only somebody who appears to be an intermediate freerider using the sail and the testimonials are only a handful of people who say they liked it.

What we all want to see is one of the really good racers from near you use it and show speed data - with speed data from his other sail on the same day.
That is objective.
If you say it stabilises your board better, that would be evident in GPS runs in rough conditions. Showing the numbers would convince us.

So far it seems you only have subjective reviews from friends.

We put final commercial version in October, we don't have racers around here. Season is over . So you guys have to wait until spring time . Yes sail go faster than regular sail same size in rough and flat conditions , all we have to do is to find name who you can trust. Or we can do this: If sail does not improve your speed over regular same size, send it back we refund your money 100%.

You have 1 GPS sailor from the USA GPS Team Challenge team (I believe your old partner Alexander Sosnin) still posting sessions in your vicinity.

And you expect an honest review from an ex partner?

gorgesailor said..

MWsails said..

Sparky said..
I was wondering, would these wingsails work best with a specific "wingsails board".
Many of us use very specific, dialled in equipment. We balance the sail with board design, board volume, fin shape and fin size.
I noticed in one of the videos the board Stan was riding looked a bit "squirrelly". A technical (Australian?) term for the back of the board being a bit loose and prone to spin out.
Have considerations been made to adapting boards and fins to be more suitable?

Hey Sparky! Wing sail instantly stabilize your board -fin configuration. This is why I riding such a small board and fin. Anyone who sail wing on my speed 54 or slalom 58 (cm wide) board instantly notice board stability. The only disadvantage of narrow boards is very narrow tail , I (and others) have trouble to fit my back foot in strap. I guess If I have narrower like 50 cm board with wider tail it would be more comfortable without loosing performance in speed. Our Wing sail is 100% better performance in all aspects compare to thing ply sail. So answering your question short: wingsail doesn't need specific board , it will work with your existing gear just fine. Using our wingsail , you will expand your windsurfing ability and probably, as a result, move to smaller board and fin, as I did. I also noticed, someone came to conclusion that wingsail better in light winds, this is wrong, wingsail is wind-hungry machine, it shows its real exiting strong and stable power in really hard winds. There is no backhand or back-foot pressure or sudden pull of drops , nothing, just stable and strong pull.
Now let me answer ( repeat) other Qs . Typical airfoils have center of lift located in front , about 25% of total chord length. This is where all lift is generated . Our wingsail reverse its profile exactly in this section ( front section) , this what makes our wing different from other designs and this is why it works . I just want to point out that other "wings" has stationary front part and moving tail section , obviously this is not enough . Some other designs just spacers btw two panels... Hope it helps.

I think perhaps the Wing fits the narrow board well - a wider board may get flighty without the mast foot pressure of a traditional race sail. That said, if it is really that efficient then you also would not "need" a wider board for planing quickly .... just a thought.

You right , no need wide board to plain quickly, but you can use wide, no problem , it just go slower due large contact surface.

BSN101 said..

Sparky said..
I was thinking the wa windsurf community should time share one? $100 each? It can live at my place? Then we can give you twenty reviews from experienced sailors in top conditions!

Yep that's what I'm getting at.

10 interested sailors.

I think there's also the mast to consider, from memory the 5.8 needs a 460 RDM? I don't have one of those, I have a 460 slightly reduced, no idea if that would work or not.

John340 said..

vortex said..

John340 said..

MWsails said..
We put final commercial version in October, we don't have racers around here. Season is over .

You have 1 GPS sailor from the USA GPS Team Challenge team (I believe your old partner Alexander Sosnin) still posting sessions in your vicinity.

And you expect an honest review from an ex partner?

Yes

you have very high expectations ;)

vortex said.. I will let you know the shipping charge to WA tomorrow.

From memory there's a surcharge if it's over a certain length, I had to agree to have the carbon I bought folded instead of rolled to get cheaper transport. I guess that isn't feasible for the sail?

Chris 249 said..
As already noted, Prof Mark Drela, aerodynamics expert from one of the world's great unis and a world record holder not just in design but in actually using his own foils, says that thin foils are BETTER in ways. If thin foils are better in ways, then your thick foils cannot give "100% better performance". Are you saying that Drela - who to let me say it once again is not just a leading scientist but a world record holder - is wrong and you are right?

Also, Tom Speer (Boeing and America's Cup wing designer) says that lift is NOT all generated from the front. He writes, for example;

"With an airfoil, the greatest pressure differences may be at the leading edge, but they are controlled by the conditions at the trailing edge. ..... you can modify the lift somewhat by changing the leading edge, but the trailing edge is where the action is with regard to determining how much lift is produced...... The shape of everything forward of that is dedicated to ensuring that the flow actually will get turned in the direction of the leech."

Similarly, Drela says "Looking at the local sail angles or flow angles at any location away from the mainsail leech says nothing conclusive about the overall aero force on the whole rig, which is what really counts" which contradicts what your site says about all lift being generated 25% back. Mark Drela does say "the front parts carry most of the lift" - but not all. He also says that how MUCH lift the front carries is determined by the shape of the leach.

Why should we believe you and not a world-record holding aerodynamics professor of world fame, or the guy who designs wings for one of the world's leading aircraft builders?

May I politely ask what your "aerodynamics background" is?

May I politely ask what races have you won? What records do you hold? What evidence of any type is there that you are right and the scientists and the guys who design and use sails that win and break records are wrong?

You have insulted other designers and other sailors in your site and your posts - what evidence do you have for the abuse you throw?

Chris, if you keep citing Drela, please provide the reference so that anyone interested in following up could read the quotes you are using in context. Without a reference, you might as well make up quotes, and attribute them to "authorities". While I don't believe that this is the case, short quotes out of context can easily be used to mislead. Your use of quotes on page 6 of this discussion is a perfect example. There, you attribute the quotes "a thin airfoil which always has the appropriate camber shape dialed in at any given operating point will in general be superior to a thick airfoil." ? toTom Speer, Boeing wing designer. But in a previous post you made in 2011 atwww.yachtsandyachting.com/forum/forum_posts.asp?TID=8431&PN=2&title=will-the-wing-take-off, you attributed the same words to Drela. You also shortened the Drela quote by omitting " but only within a narrow CL range (or alpha range)" this time. That may be irrelevant to most windsurfers, who only care about how the wing sails works in actual sailing, but for the few here who are interested in the theory, please cite accurately, and provide complete references, not just names.

That said, citing "the authorities" is a bit beside the point. Developing something radically new requires a very strong believe that the "authorities" are wrong, or have missed something. There are enough pointers, both theoretical and real-world (e.g. air plane and glider wings), to say that a wing sail might have advantages. The question remains whether or not the current implementation does have advantages.

MWsails statement "it's too cold here for more tests" is a rather lazy answer. Plenty of windsurfing going on right now in Australia, and quite a few windsurfers eager to test! Many of them also have plenty of boards, from big slalom to narrow speed boards, to use the board that works best with the sail. Even in the US, there are a few spots where it's windy and warm year-round. Corpus Christi is one of them. It has a great windsurf shop right on the water, and plenty of free riders and slalom sailors.

BSN101 said..

vortex said..

BSN101 said..
MW, can you advise of price to get a sail to Western Australia, say Perth. Cheaper if 2 come?

BSN101
I will let you know the shipping charge to WA tomorrow.

awesome, and price for 2 wings.

Cheers

Shipping cost for one Sail to West Australia is about $175 USD.

A few demos in a few w'surf shops could go a long way towards people being able to try one w/o having to buy.
Just basic promotion.

NelsonFoils said..




A sail rig can operate at comparatively high lift coefficients even in high winds because it has the luxury of being able to reduce area. This makes the narrower operating range of the thin section acceptable."

?????????????????????????????

by going back to the beach and taking a different sail !

As I've said repeatedly, wingsails can have some advantages and wind range may be one. I can also point out that the narrow operating range of a thin sail can also be effectively changed by things like bearing away in a gust and by leach twist and outhaul. As Drela says here "But a soft sail allows the possibility of changing the camber of a thin airfoil, which can greatly extend the low-drag range if done appropriately. So a thin airfoil which always has the appropriate camber shape dialed in at any given operating point will in general be superior to a thick airfoil. " (Reference www.boatdesign.net/threads/soft-wing-sail.18422/page-4 )

The issue is whether the wingsails are better overall (whether as Stan says he has "better product in any aspect ") or whether they are better in some conditions and worse in others. I often sail in conditions where high lift is important to me, and in many conditions high lift is important to all of us. Whether having more lift is better than having a wider range is something worth exploring, but Stan keeps on avoiding the issue and claiming that his sails are "100% better in all respects".

You also keep on refusing to ask a couple of simple questions about wingsails - for example, why don't you tell me whether you think Mark Drela is wrong? It"s a simple question so why not answer it?

If the wingsail fans were willing to have a discussion about these aspects then we could probably have an interesting chat. When they are only going to snipe at anyone who dares to ask questions and treat us as if we have no right to query their claims, we'll just have flame wars -and probably fewer people will get into wingsails.

In the end, it's really simple - just prove the claims and we will accept them.

As I have said before ,so I did not refuse to answer your question . The answer has been has been removed (maybe before you had the chance to read it).

I have the very greatest respect for anyone who has done extensive research especially if they don't have unlimited resources at their disposal .
Both Mr. Drela and Mr. Speer did great work in their field 20- 30 or more years ago .

"But a soft sail allows the possibility of changing (TRIMMING downhole , outhole *) the camber of a thin airfoil, which can greatly extend the low-drag range if done appropriately. So a thin airfoil which always has the appropriate camber shape dialed in at any given operating point will in general be superior to a thick airfoil. "

* no need for changing the shape by trimming (downhole , outhole or having half the sail twist of to reduce power) on a wingsail , you just ajust the AoA with your back hand and take out the power you need or can handle in relation to the varying (wind , water ,(your degree of fatigue , the size of your b?lls) conditions .

More lift and having a wider range are not mutually exclusive...you can have a high lift wingsail with a very wide range .

^^^ let back hand off, reduce fin pressure, squirrelly board. Or is this not so in the parallel universe that is wingsails?

Chris 249 said..
Tom Speer has been designing America's Cup wing sections much more recently than that.

Would you mind providing links or quotes to confirm that you can have a wingsail with "high lift" (ie comparable to that of a thin sail)????

Yes, I understand that a wingsail can have a wider effective angle of attack.

is there a reason that a wingsail (same size , layout , profil depth) would have less lift than a thin sail ??? less Drag certainly ...

https://www.avweb.com/news/airman/183261-1.html?redirected=1

Mark _australia said..

MWsails said..

Mark _australia said..

MWsails said..We put final commercial version in October, we don't have racers around here. Season is over . So you guys have to wait until spring time . Yes sail go faster than regular sail same size in rough and flat conditions , all we have to do is to find name who you can trust. Or we can do this: If sail does not improve your speed over regular same size, send it back we refund your money 100%.

#1- So u have gone all out pimping it on forums and a website - but in your long testing and development you have not had a really good sailor test it side-by-side with other equipment?
I am not after a name we can trust - just the same proficient sailor using it, alternating with his regular sail, and GPS readings for the day as he swaps sails a few times.
Your sail did not just materialise from nowhere, it has taken a while to develop, so I don't think "its not our season at the moment" is really an answer.
If I asked Ben Severne in our winter 6mths ago how the 2018 sail performs, he will be able to tell me all about the 2 yrs of testing ....... not say "oh its not the season now so I dunno..."

Where are the test numbers from last season....?


Then #2- so you are saying it has a wider range and the 5.8 will replace all my sails from 4.2 to 6m or so?
Plus it is faster in flat and open water?

And you guarantee that 100%?

Yes I garanty that 100%. The rest I will answer later when i get home.

Still waiting.

Cancel the physics lessons, I'd just be happy to see something like:

Bob Smith used the sail and on his 7m Reflex4 he was getting 30kn runs
on the 5.8 windsail he got 34kn runs. The wind was constant 25kn for the whole 2hr testing period (etc)
here's a table of all the GPS numbers ....................

Even if you can't do that here's what is still subjective but would count more than the salesman speak you have so far:

Pete Jones used his 4.5 all day then went to the 5.8 wingsail here's the video of both sails taken 10min apart. (Not just grandiose statements about massive wind range)

Joe Joespehson was overpowered on a 5.5 NCX. He changed to a 5.8 Wingsail and it was clearly more in control - here's the video of both sails taken 10min apart.

Sure here we go, Luke , on my video was riding his 4 meter sail he was fully powered but slower than wing , than he took 5.8 wing and was surprised with wing 's stability and speed, than he hooked wing to his own board that he was using on 4 meter sail that day and he said that board become stable and fast. After, he posted review on MW sails site. Luke is real person and he have account on Facebook.
Is this good enough?

Chris 249 said..

NelsonFoils said..




A sail rig can operate at comparatively high lift coefficients even in high winds because it has the luxury of being able to reduce area. This makes the narrower operating range of the thin section acceptable."

?????????????????????????????

by going back to the beach and taking a different sail !

As I've said repeatedly, wingsails can have some advantages and wind range may be one. I can also point out that the narrow operating range of a thin sail can also be effectively changed by things like bearing away in a gust and by leach twist and outhaul. As Drela says here "But a soft sail allows the possibility of changing the camber of a thin airfoil, which can greatly extend the low-drag range if done appropriately. So a thin airfoil which always has the appropriate camber shape dialed in at any given operating point will in general be superior to a thick airfoil. " (Reference www.boatdesign.net/threads/soft-wing-sail.18422/page-4 )

The issue is whether the wingsails are better overall (whether as Stan says he has "better product in any aspect ") or whether they are better in some conditions and worse in others. I often sail in conditions where high lift is important to me, and in many conditions high lift is important to all of us. Whether having more lift is better than having a wider range is something worth exploring, but Stan keeps on avoiding the issue and claiming that his sails are "100% better in all respects".

You also keep on refusing to ask a couple of simple questions about wingsails - for example, why don't you tell me whether you think Mark Drela is wrong? It"s a simple question so why not answer it?

If the wingsail fans were willing to have a discussion about these aspects then we could probably have an interesting chat. When they are only going to snipe at anyone who dares to ask questions and treat us as if we have no right to query their claims, we'll just have flame wars -and probably fewer people will get into wingsails.

In the end, it's really simple - just prove the claims and we will accept them.

Chris, I agree with Drela, as I said before thin airfoil working fine in very small performance envelope, outside of envelope thing airfoil become totally useless. This is the reason we have many different sail sizes , each of the size has own envelope ( range) . I'm sorry that you become offended that I ( and many others ) call curved plate profile primitive , but this is how things are. And if you feel that way, than you feel that way ,nothing I can do about it .

MWsails said..

hardie said..
A lot of wisdom has been offered here.

The internet has bought in the Information Age, very easy to sort the hype and trype from the knowledge, and facts.

Proof is now required to back up claims.

I love to support windsurfing and innovation. I have an annual budget of $XXXX and spend it every year. Currently I have many main brand production sails, and my GPS data has shown that at 57 as I'm slowing down mentally and physically I am sailing faster and faster, predominantly using same boards and fins, only difference being new sails. The say the bull**** stops when the data drops. My GPS data is proof the new sails have helped me to go faster, as I age and weary.

My sails are very easy to rig, your video shows your sails are harder to rig. So the only thing that would tempt me to buy your sail was if they were demonstrably faster on GPS. If I could try one and smash my PB's, I would definitely hand over my cash.

Hardie, right, Latest design is short sail with very low center of lift, Is not really efficient but it allowing you to keep hi angle of attack. Plus matching friction of the board, etc ( narroow board is not always fastest board). Than it steep downwind run when relative wind actually drops to the point when you can't go faster and you wish you have larger lifting surface. The reason why my sail is better for speed sailing is because it allows you to have 5.8 area with larger lifting surface and very stable and confident run. You still need to apply all your speedsailing tricks but opportunity go faster is right on my website. I'm not pressuring anyone to buy sail , first of all I do not financially depend on sail making , I have other more profitable business . The very reason why I'm doing this is same reason of why you keep trying to break your own speed record.

I think its fantastic that you are developing these sails, I encourage you to continue, better than doing a lot of other bad habits with your time.

The issue you have is how to market the sail. It is obvious to see that what you have tried so far, has created a lot of negative publicity for yourself, and so maybe you could try a different approach, and benefit from some of the wisdom shared here.