HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Aug 12, 2011, 05:29 PM
Guz
Gutless wonder
Guz's Avatar
Tempe, AZ
Joined Dec 2005
3,136 Posts
Quote:
Originally Posted by rcsoar4fun View Post
Actually its an important distinction. An aircraft is mostly subjected to fairly evenly and slowly applied loads.

A wing mast gets much more severe shock loads, from gusts of winds and particularly the inevitable capsize. Something brittle like monokote gets after a few years will lead to a mast full or holes or broken. This would be the same issue with a doped covering.

I have not tried the monokote since the reformulation, so I cannot comment on its longevity.
Now if you really want to get a strong wing sail, you go down the path of foam core (hot wire cut), bagged wings, which can be even lighter than ribbed/skinned wings.

If you're curious, check out DLG (discus launch glider) foam core wings. They take some serious shock loads on launch/land, just to give an example.
Guz is offline Find More Posts by Guz
Reply With Quote
Sign up now
to remove ads between posts
Old Aug 12, 2011, 05:38 PM
Registered User
Corpus Christi, Texas, United States
Joined May 2003
1,279 Posts
Bagged wings are actually a lot more simple to build in some respects, and its finished once is out of the bag (well, after a little sanding). A set of foam cores is fairly easy to cut, bagging is just a bit tricky. Its not hard, just 10 big steps completed all at once.

Another option to consider is foam ribs for the main wing. They could easily be cut from a chunk of foam with $20 in equipment, then sliced into 1/4" sections to form the ribs. Attach to a carbon spar, cover and presto! a wing.
rcsoar4fun is offline Find More Posts by rcsoar4fun
Reply With Quote
Old Aug 12, 2011, 09:47 PM
slow & draggy...
Hobiestoke's Avatar
Albuquerque, NM
Joined Jul 2004
463 Posts
I would agree that the floral film solution would only be for a temporary solution just for testing purposes and really nearly any kind of film even tsp40 may not have a good asthetic on the boat, if that beauty were mine, id probably just try to build a jib wing thats a scaled down version of what you built for the mainsail wing so the boat would have a nice consistent look overall. I also agree with the foam wing bagging method being very strong ive used that method w several planes and it makes for a very tough foil. Im curious what is the main wing fabricated from anyway balsa, CF? Hulls are fiberglass right? forgive me if youve already answered this in an earlier part of the thread....

Opps, just checked an earlier part of the thread, Maybe the PVC sheeting you used for the framework and main would be fine,
is the concern an issue of weight?
Hobiestoke is offline Find More Posts by Hobiestoke
Last edited by Hobiestoke; Aug 12, 2011 at 09:53 PM.
Reply With Quote
Old Aug 13, 2011, 01:30 PM
Registered User
USA, LA, Mandeville
Joined Feb 2005
886 Posts
Anyone watching the AC 45 boats race off of Cascais? They are on youtube, and even live feeds, when they are working.

ACWS Cascais - Race Day 5 - Highlights (23 min 57 sec)
for day 5 racing, with links to all of the other days' racing! Great shots of the wings in action.
hew565 is offline Find More Posts by hew565
Reply With Quote
Old Aug 24, 2011, 04:52 AM
Registered User
Espaņa, CT, Barcelona
Joined Aug 2011
21 Posts
Dear DAN:
I'm trying to build a wingsail for our single hull RC (1 meter), and compare the sailing results with its normal RC sail.
Where can I get the proportional dimensions for the wingsail?
Thank you.


My problem is: if we have a 94 cm monohull RC model, with total existing 0,49 sqm sails (jib and mainsail) and a 128 cm mast, which is the wingsail version to be compared with?
That meens: if we want to compare the effectivity between both, in equal varius wind conditions, which is the sail surface and thikness and the mast height? What dimension of wingsail corresponds, in parity, to the actually existing sail.

We have had a look at the messures of the last BMW-Oracle and Alinghi: the wingsail of BMW-Oracle is of about 56% the sail of Alinghi, and the mast is 25% higher.

The RC model with the wingsail: does it need a jib also? If not, why? And no shrouds? BMW-Oracle had!

We know already that the mast must rotate, and that the wingsail has two parts, one fixed to the mast (with a typical wing section), and another behind, with the shifted axis, and thinner, both connected and working together.
Will it realy work?
salazar is offline Find More Posts by salazar
Last edited by salazar; Aug 24, 2011 at 01:49 PM. Reason: forwarded information
Reply With Quote
Old Aug 24, 2011, 07:31 AM
Dan Elliott
United States, TN, Nashville
Joined Jul 2011
111 Posts
Wingsail Size

Salazar, I'm happy to help. And glad to hear of your interest in wingsails. My first attempt at a wingsail was for my ENTZ 1 meter monohull. I simply followed the outline of the fabric sail area and made the wing to match. I quickly learned that the front and back halves of the wing have to be close to equal in area in order for the wing to work right. That being said, I've taken your mast measurement and scaled a wingsail to fit it. (813" sq. area). The front and back halves are close to equal. Let me know how the experiment goes.
Dan Elliott is offline Find More Posts by Dan Elliott
Reply With Quote
Old Aug 26, 2011, 12:53 PM
Registered User
USA, LA, Mandeville
Joined Feb 2005
886 Posts
I would love to see your results too, but fear the wingsail is not suited to monohulls. Maybe Dick can chime in here, but I think that the main advantage of the wing is it's lower drag. If a monohull is already at it's hull speed, there is not much more you can do to speed it up. A multihull's hull speed is much higher, so a lower drag sailplan will result in higher speeds.

Also, a more powerful wingsail is most efficient when close to vertical (note BMW Oracle pulling the wing to vertical when the hulls were flying). On a monohull, the extra power (and weight) will cause more heeling.

Perhaps a canting keel setup would negate this problem. My opinions only and they are worth what you paid for them!
hew565 is offline Find More Posts by hew565
Reply With Quote
Old Aug 30, 2011, 05:03 PM
Registered User
1967250s's Avatar
United States, VA, Alexandria
Joined Sep 2008
987 Posts
[QUOTE=hew565;19151579]I would love to see your results too, but fear the wingsail is not suited to monohulls. Maybe Dick can chime in here, but I think that the main advantage of the wing is it's lower drag. If a monohull is already at it's hull speed, there is not much more you can do to speed it up. A multihull's hull speed is much higher, so a lower drag sailplan will result in higher speeds.

I would disagree. Some monohulls have a planing hull and would definitely like a more powerful, faster sail. Also, the displacement type hull would benefit from more directional lift/thrust, giving it faster performance in the turns. After all, a regular sail is a wing, just with less lift than a shaped wing sail. With a wing sail you can reduce or increase the heel angle and add hull speed according to the shape. At least, that is the way I see it as a sailor and flyer.
Any other thoughts?
1967250s is offline Find More Posts by 1967250s
Reply With Quote
Old Aug 30, 2011, 07:45 PM
Registered User
Dick L.'s Avatar
Minnesota, USA
Joined Aug 2002
2,179 Posts
I would agree with Hew's position for two reasons -

1. A multihull platform is light and seldom displaces much water. It is NOT limited by a formula/calculated hull speed as most (all) displacement boats are.
2. In my years of sailing, I have yet to see any displacement hull with a fixed lead keel actually plane for any length of time/distance in the sizes we are considering. Most planning hulls are boats with centerboard or daggerboards, and are not ballasted by lead - but (usually) by moveable ballast - i.e. a moveable body, or two - or more. Note - I am discounting any displacement hull that is photographed planing on the face of a wave. I am suggesting fairly flat water, possibly aided by a big spinnaker lifting the bow.

I wouldn't discourage the trial of a solid wing on a monohull - but with the knowledge of wings (getting better each year) and the ability to use on a monohull - if they really were a breakthrough, I would offer most would be using them where the class allows.

As for turning performance, it might be possible to gain a small advantage - but as known by multihulls - you have lost more distance when tacking - so keeping tacks on any leg to a minimum is definitely faster than entering into a tacking duel. Likewise, tacking (gybing) downwind is proven faster in most medium to strong wind strengths, than simply "barn-dooring" it directly downwind. Take a look at the "polars" for most competitive class racing sailboats, and the fastest point of sail is on a broad reach. The key to using it to your advantage is knowing how much ground you are giving up and if that loss can be overcome by faster boat speed over a longer distance.

Just my opinion of course, although it is supported by experience and time on the water.
Dick L. is offline Find More Posts by Dick L.
Reply With Quote
Old Sep 05, 2011, 06:57 PM
Registered User
Espaņa, CT, Barcelona
Joined Aug 2011
21 Posts
SAIL vs WINGSAIL in comparison

HI,
Thank you very much for your international and interesting interventions or information. Thank's to the american's: Dick L., 1967250 and shew565, and to the british: Dan Elliott. In the forum I've seen somebody named Hydroptere from Germany, who is a very good modelmaker or "BASTLER". Bitte, wenn Sie sich mit mir in Verbindung setzen, würde ich mich gerne mit Ihnen unterhalten.
As you see I speak and write and understand both, english and german.

Well, I tell you that we will begin modelling the wingsail in October.

I have been speaking with a professional australian sailer, and wingsail designer, and have resumed your opinions in the forum.
Without considering the very specific technical contents, he said that it is better a monohull with a wingsail than a multihull, because it lifts the boat a litlle bit and helps to increase planning efect and, by the way, the speed. This does not happen with multihulls that cut the water as a knife (they do not plan). But, in all the cases, the position of the mast has to be perpendicular (90 degrees) to the water surface, not to the boat surface (or better if you pass it, more degrees, because the lift effect of the wingsail increases). Sometimes you can not arange it, in reality, because of the high forces you have to overcome.

It is better if you combine also the wingsail with a canting keel to reequilibrate the heeling, but heeling is not the problem (in monohulls).

He also told me that the difference is the distance: if it's a very large camp, the wingsail seems to be unbeatible. But with smaller regatta camps, the turnings are too slow, and the wingsail stops the boat.

So far, PABLO
salazar is offline Find More Posts by salazar
Last edited by salazar; Sep 05, 2011 at 07:08 PM. Reason: mistakes
Reply With Quote
Old Sep 06, 2011, 09:05 AM
Registered User
Dolores, Colorado
Joined Dec 2007
1,581 Posts
I followed Hydropters building thread on a German Forum.
His built is just outstanding, the guy knows how to built something extremly light weight.
But I have the feeling, that his built is to complicated, or lets call it to advanced. His muti hull platform is not very stable, too.
Sadly his thread has stoped for several month and he had never any real videos that showed his rig in action, just a view very short clips, but with that unstable platform of his, inconclusive.
Schrott is online now Find More Posts by Schrott
Reply With Quote
Old Sep 08, 2011, 04:15 AM
Registered User
disabled's Avatar
Vienna/Austria
Joined Jan 2009
1,055 Posts
I followed his buildlog too.

Quote:
Originally Posted by Schrott View Post
I followed Hydropters building thread on a German Forum.
His built is just outstanding, the guy knows how to built something extremly light weight.
But I have the feeling, that his built is to complicated, or lets call it to advanced. His muti hull platform is not very stable, too.
Sadly his thread has stoped for several month and he had never any real videos that showed his rig in action, just a view very short clips, but with that unstable platform of his, inconclusive.
Actually he hasnīt stopped his build log at all , but has got the option of being on TV with his wing!!!
He is building his wing - including all improvements caused by the gathered expereince - once again. And this time all the buildingsteps will be in that TV-report! He is simply very busy with that.

So lets just be patient and wait untill this will be published.
It will be worth it!
_________________

And if you are really interested in more stuff about Wingsails,
you may read about my own considerations here:
http://www.rcsailing.net/forum1/show...onohull/page11
And the pages before that one.

Even if it may be more expensive,
I still believe it would be easier to build a bigger wing unit first -> for a 2 Meter boat!!!
disabled is offline Find More Posts by disabled
Last edited by disabled; Sep 08, 2011 at 04:22 AM.
Reply With Quote
Old Sep 08, 2011, 05:16 AM
Registered User
james carey's Avatar
Jakarta Indonesia
Joined Jun 2006
228 Posts
oops !
james carey is offline Find More Posts by james carey
Last edited by james carey; Sep 08, 2011 at 05:22 AM. Reason: oops!
Reply With Quote
Old Sep 08, 2011, 09:12 AM
Registered User
Espaņa, CT, Barcelona
Joined Aug 2011
21 Posts
Danke schön, DISABLED!
I think we all will wait for this film.

As I see in the pictures of DIM LEMKE, the wing is not symetric. It's build like a RC-plane wing? It's OK? Tell me why, please.
salazar is offline Find More Posts by salazar
Reply With Quote
Old Sep 09, 2011, 05:19 AM
Registered User
disabled's Avatar
Vienna/Austria
Joined Jan 2009
1,055 Posts
Quote:
Originally Posted by salazar View Post
Danke schön, DISABLED!
I think we all will wait for this film.

As I see in the pictures of DIM LEMKE, the wing is not symetric. It's build like a RC-plane wing? It's OK? Tell me why, please.
I donīt know what Dick Lemke is doing, why he is doing it that way - or if it is OK at all.

But if you want to sail on both sides - starboard and portside tack - you need to have adjustable profiles.
If you just want to sail on one side (like in record attempts), you could use asymetric profiles - simple!

I really canīt tell you anything about Dick Lemkes intentions - please ask himself.
disabled is offline Find More Posts by disabled
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Simple slow plodding catamaran Gary Mortimer Racing Boats - Electric 6 Sep 30, 2011 08:50 AM
Discussion 49" long by 16" wide catamaran SirWolf2012 Racing Boats - Electric 2 Jun 29, 2011 08:55 PM
Sold Victor model Products Wildcat Catamaran kit Robert Pulse Boats (FS/W) 0 Dec 21, 2010 08:16 AM
Scale model of Seacat (hoverspeed) catamaran remondo Scale Boats 16 Apr 26, 2010 01:32 PM
RC model catamaran? john.631 Sailboats 5 Aug 16, 2005 11:46 AM