During this past year I received an e-mail from Will Gorgen asking my opinion of the idea of using wings(similar to IACC wings) for generating extra lateral resistance when the canting mast system on Will’s boat caused it to heel a lot rendering the normal keel ineffective. I had a problem with the wings because they are always there-in light air and downwind when not needed.
Later on in the year I found an article in Australian Sailing that showed a new “Sydney Harbor Racer” called “Bondi Tram” that featured wings exactly along the lines Will had suggested and were being used to generate lateral resistance on this new boat when the keel canted. On full size boats up until “Bondi Tram” when a keel canted extra lateral resistance was required in the form of CBTF(twin foils), a gybing daggerboard,twin asymetrical daggerboards or a single fixed(non- gybing) daggerboard.
At ths same time Graham was designing the F100CBTF and at that time it was looking like the CBTF concept might not work on a model-that changed as time went by-but it started me thinking about what other kind of lateral resistance I could use on the F100 if Graham’s analysis proved that CBTF was not viable.
I kept thinking about wings because they don’t require any mods to the hull or change balance in any way-but I couldn’t get past the fact that they are there all the time even when you don’t need them…
Finally, over on the coast one day, it dawned on me:why not retract the “wings” so that they blended in to the bottom of the bulb! The more I thought about it the better I liked it and the more I began to realize this could be a patentable idea. I knew Will was about to need a decision on the form of lateral resistance he would use on his one meter so after he signed a non-disclosure agreement I sent the idea to him to consider. He liked it and added a suggestion that as a possible alternative to having he kFOIL? on the bottom of the bulb it might work better in some applications retracting into a slot in the bulb-that was great! So we had the two main embodiments of this idea.
The idea,again, is to have a retractable foil under or in the ballast bulb and controlled by a shaft running up thru the keel fin: rotate the shaft 90 degrees and the foil deploys; rotate it back and it retracts. Will had another suggestion for dual foils as did another friend so there are three applications of the kFOIL? that can be incorporated into canting keels.The final application for this foil is one where it would be placed at the bottom of or in a slot near the bottom of a low aspect fixed keel. It could be deployed when going to weather in strong winds to improve upwind performance and retracted at other times. It could allow low aspect fixed keels to be designed with less area than they otherwise might have.
In model canting keel boats the kFOIL? allows extra lateral resistance without having to have a fixed dagerboard,CBTF etc.
This foil will be tested by Will Gorgen on his US One Meter and it will be used on both my CK Trainer prototypes. Two F100’s with CBTF and the kFOIL? will be raced to test this concept further.And the concept will be tested as well on full size boats.Though this is a patent applied for technology it will be available for any individual to use for FREE. All manufacturers,without exception, will have equal access to this system. And for the CK Trainer any manufacturer will be able to use this system for FREE specifically for and limited to the CK Trainer.
Thanks to Will Gorgen for getting me thinking about wings and for the ideas and help in working this out and to: Bruce Mc Daniel,Matthew Lingley, Geoff Moehl and Marc Kelly for the discussions and feedback. Thanks to Chad for a great forum and he should know that this is the first public description of the kFOIL? anywhere.
See the follow up post by Will Gorgen including his illustrations and comments on the kFOIL?..
UPDATE: How I could have left Bruce McPhersons name off the list of those to thank is beyond me! Thanks,man! You’re encouragement was and is key to this development!
edt: aditional info 3/13/04
Doug Lord
–High Technology Sailing/Racing

As Doug mentioned in his post, he has come up with a new idea for retractable keel wings that I think has a lot of merit.

As my canting mast US1M project began to take form over the past year, I came to the realization that as the hull heeled excessively, the keel would loose its effectiveness for generating lateral resistance. I had the idea that if I added wings to the keel bulb they would be able to generate the lateral resistance at those high heel angles. I ran the idea by Doug Lord (among others). He and I both felt that the boat would be handicapped by the extra wetted surface area of the wings. In light air and down wind when the wings were not needed to help generate lateral resistance, they would be a serious liability.

As Doug mentioned, he found a magazine article in Australian Sailing Magazine about “Bondi Tram” that featured wings exactly along the lines I had imagined. Bondi Tram uses a canting keel and the wings were added to generate extra lateral resistance on this new boat when the keel was canted to high angles.

Heartened by Bondi Tram, I kept the wings in my design intent and proceeded forward with the rest of the design. I made provisions in the design for the wings to be removed so that I could evaluate the boatspeed and balance with and without the wings. I guessed that I would probably find in heavier air, when the boat was prone to high heel angles, the wings would be needed and I would just pay the price downwind. In lighter winds when the upwind heel was less severe, I guessed that the wings might need to be removed.

Then, a few months back, I received an email from Doug telling me he might have a solution to my dilemma. His idea incorporated wings on the keel that could be stowed away when they were not needed and deployed when they were needed. The wings would be attached to the keel bulb so that they could pivot around the center of the wing. When deployed, the wing would be perpendicular to the keel bulb axis just like the wings we are all used to seeing on IACC boats. But by pivoting the wing 90 degrees, the wing would be aligned with the axis of the keel bulb and would then be in a stowed position either inside the keel bulb or along the bottom of the bulb. I’ve included some pictures of the concept to help make it clearer. It was brilliant in its simplicity.

The advantage of this kFOIL was instantly clear to me. When the boat heeled, the wings could be deployed to increase the lateral resistance and improve upwind performance. When the wind was light or when going downwind, the keel would be able to generate sufficient lateral resistance and the wings could be retracted. More importantly, it would allow me to generate the extra lateral resistance I think I will need at high heel angles within the rules of the US1M class which do not allow a forward rudder or a canting daggerboard. Another advantage of the system is that the wing can be pivoted to release weeds that might get caught on the wings.

With the single wing, the implementation is simple enough. A slot is machined in the keel bulb running lengthwise and cutting all the way through the bulb (open on both sides) large enough to house the wing. The keel strut is built with a tube inside it running from the bulb to the hull. A shaft is installed down the tube and connected to the wing on the bottom and to the servo in the hull via a pushrod and horn system. The only detail yet to be worked out is how to seal the cavity in the bulb to make it hydrodynamically smooth. Initially, I envisioned a slotted gasket (much like those used for centerboard trunks on many types of dinghies). Building such a gasket in a small enough size might prove tricky. Another option would be to use a smooth foam rubber as the gasket material. A soft neoprene might be the way to go. The material would need to be soft enough so that the wing could slide through the split line with little resistance and would be smooth enough to minimize the turbulence.

Here are some renderings of the idea so that you can visualize what we are talking about:

Download Attachment: kFOIL102.jpg

Download Attachment: kFOIL201.jpg

I am currently building a kFOIL system into my canting mast US1M. I have already begun fabrication of a keel strut with a tube inserted in it to allow for the shaft. I will modify the keel bulb once the keel strut is completed. I have procured a stainless steel airfoil section that is the appropriate size for the wing. It is a constant chord section so I may attempt to taper it at the tips and then blend out the airfoil shape. I am currently designing an alignment system to hold the wing at a fixed angle of attack (without slop) using a stubby shaft that would protrude out the top and bottom of the wing and ride on Teflon bearings in the keel bulb.

The great thing about the kFOIL system is that it will allow me to do some fairly extensive testing without having to change the boat’s configuration. For example, if I want to evaluate the effectiveness of the wings, I can first sail the boat against my trial horse with the wings stowed and then with a flip of the stick on my controller, I can sail against my trial horse with the wings deployed. I can repeat this experiment in different wind conditions where my heel varies from only a few degrees to extreme heel angles. Based on these tests, I should be able to establish under which conditions (if any) the kFOIL gives me a performance advantage and in which conditions (if any) it hurts my speed. I can do similar experiments with my canting mast system (i.e. leave it centered for the first test run against a trial horse and then cant it for the second test run). If I can find steady enough wind conditions, I should be able to develop a good set of comparative data to evaluate the effectiveness of this system

I am really optimistic about the prospects for this system and felt that others could benefit from this system on the various canting keel boat designs that are being developed (CK Trainer) or even on lighter weight boats (like some of the extremely light weight US1M designs) which are prone to excessive heeling and the resulting loss of lateral resistance.

  • Will

Will Gorgen

Just an early thought to keep this thread from getting out of hand as they have in the past.

In describing this (and other untested concepts) it would be very helpful to avoid claims of design “breakthroughs” and potential speed advantages.

I think people would be interested in the efforts to design, build and test this concept and to see how it performs in the real world. It is certainly a novel idea.

However, long discussions of proposed theoritcal benefits of another apparently proprietary, trademarked “concept” will likely only lead to contentious disagreements all too familar to this board between those who look for real world proof and those whose eyes seemed locked into the future…

As was pointed out in the original post “wings” used for the specific purpose of generating lateral resistance HAVE been tested on the full size “Bondi Tram”.
Testing the kFOIL? on models and full size boats will be ongoing…

Doug Lord
–High Technology Sailing/Racing

Hey Roy,

I’m approaching this very scientifically. As I pointed out in my post, I will be able to switch the wings on and off with a flip of the stick on my controller. So I can evaluate the performance of my boat relative to a trialhorse boat while sailing. I don’t neet to bring the boat into shore and make a change and then go out and hope that nothing else is different. This should allow me to make some fairly definative statements about the advantages or lack thereof.

I have confidence that the system will generate the extra lateral resitance that I want it to. But the question still remains as to whether this will prove to be a speed advantage in terms of VMG or whether the extra drag will more than offset the reduced leeway. My guess (and this is only a guess) is that there will be some heel angle where the system will break even. Any heel greater than that break even point and you will want to have the wings deployed. Any heel angle less than that and you will want them stowed.

Since when the wings are stowed, it is like they are not even there, there should be no loss of performance. But of course I am counting on this system providing a benefit, so I am designing my boat about 1.5 lbs lighter than a standard Cobra. If the system does not work, then I may be handicapped relative to other US1M by my lighter ballast… That is a risk I am willing to take in the name of progress…

  • Will

Will Gorgen

Im not trying to start anything here but how can you put a patent on something as generic as “retractable wings”?. And why would you? I saw a guy with a spider 24 with folding wings back in 1999. They were smaller than the ones in your picture, and a bit further aft, but they were retractable wings which folded into the bulb. He used a hydraulic ram to actuate them. He told me he had also experimented with just one wing which could swing from one side to the other and was set on the “low” side of the bulb to increase lateral plane when sailing upwind and folded away for running downwind.
Im sorry, but I just cant see what is so revolutionary. This idea has been around for a while, so much so that most classes that allow wings stipulate that they must be “fixed” and not retactable.

So whats with the trademark stuff?


Tranth, over the last few months a number of us did an exhaustive search into a “pivotably deployable foil system” and found nothing anywhere.Thats why the patent was applied for…
A number of boats both big and small could benefit from this if it proves to be good enough.
Would love to see pictures of and a description of the system you refer to.
kFOIL? is being trademarked because it can be and to give additonal legal protection to the concept.
But as per the original post it is being made available to individuals for free and to manufacturer’s on an equal basis…

Doug Lord
–High Technology Sailing/Racing

Will: Just trying to stop a fire before it gets started.

However, given the posts filed about concepts already proven in “big boats” and proprietary “trademarked” designs, I can feel this thread heading in the typical direction…

I cerainly will be very interested to see your results from real world testing, usually, things never turn out as straightforward as they seem in the beginning, but who knows…

You are missing the point. If i build, and sell, a bulb with folding wings, you would have absolutely no chance of enforcing any legal right to it. The datails of any patent would be too specific to stop me. Why do you think everyone can build winged keels? You are claiming as your own something that is old technology and has been tried many times before. As i said earlier I have seen a trailer sailer with a full size, working example. Not just a rendering, not a theory, a full size working example five years ago of something that you are saying is radical and new. That “patent protection” crap is just rediculous. You’ve invented nothing. You’ve revolutionised nothing and I’m betting you’ve built nothing. Why persist with that stuff? It gets people offside and if you are going to share it anyway why bother?


Patents are standard ways to protect intellectual property. My own company holds many patents on technologies that we use in our jet engine designs. We patent these ideas and designs not only so that we can prevent others from using designs that we spent substantial reseach and development funds to develop but also to protect our ability to use them ourselves. This is a subtle point: If someone else were to come along and patent our idea when we did not, they could effectively prevent us from using ur own idea.

Doug came up with this idea on his own. And while someone else out there may have had the idea earlier, they failed to protect it. Doug has every right to protect his idea in such a way that he can profit from this invention by either manufacturing boats that use this idea himself or by licensing it out to others.

Now patent law only extends to those that are trying to make money from an idea. Therefore, almost all patented ideas can be used by individuals without any legal hassels. And in fact the patent documents describe how the idea works, so the inventor is effectively teaching others how to do it by filing the patent.

I’m sorry that this is so off-putting for you. But the fact of the matter is that this is an accepted way for inventors like Doug to protect their ideas. And Doug has every right to pursue that path.

  • Will

Will Gorgen

Will: A few legal corrections. First, patent (and other aspects of intellectual property) law does not apply only “to those who are trying to make money from an idea”. Most importantly in the world of model boats, an individual does not have a free right to copy or splash a design even for “individual” use.

Second, just because someone has failed to timely patent their design does not mean that a subsequent filer of a patent has free and clear rights. An outlandish but true example–in Australia I believe someone filed and received a patent for the wheel. That patent did not stand up and the holder did not receive royalties on every wheel in Australia! If what Troy says is true, at the end of the day, the “k-foil” patent would not stand up to challenge.

Finally, on a related “legal” topic, since the US1M rule prohibits moving keels and ballast, I assume that this foil concept is not class legal.

A “trademark” is a registration of a name or a graphic design. It is <u>NOT</u> the same thing as a patent.

I can register a tradmark and call it an “Rfoiler” and it will be trademarked, but not patented. To qualify as a patent, it must have drawings, it must have specifications, it must have a clear and precise description of how it works and it must be accompanied with a filing fee to the US Patent Office. Then it “may” be issued a patent number IF it is significantly different than similar ideas. In the meantime, one can only promote the item with a “Patent Pending” identification.

Are you claiming “PATENT” or are you claiming “TRADEMARK” ? Please be specific since they are completely different.



Honestly… (sigh)

I think you’re a goose


<blockquote id=“quote”><font size=“1” face=“Verdana, Arial, Helvetica” id=“quote”>quote:<hr height=“1” noshade id=“quote”>Originally posted by lorsail

A Utility Patent and a Trademark have both been applied for.
<hr height=“1” noshade id=“quote”></blockquote id=“quote”></font id=“quote”>

Thus - the kFOIL is neither “patented” or “trademarked” YET !

Lets try to get this topic back on the kFoil?; if you want to discuss patents and trademarks please start another topic and I’m sure that those of us with one or the other or both will be more than willing to try to help answer any questions.
The kFOIL? has a lot to contribute to canting keels and perhaps to low aspect fixed keels as well. If you’re just starting this topic check out the first two posts- especially the renderings on Will’s first post.

I removed my last two patent related comments though one still appears in the previous post; just trying to start to get back on topic-if we all work on this I’m sure we can do it…

Doug Lord
–High Technology Sailing/Racing

Less than two weeks since everything blew up on this board and here we go again—

“The kfoil™ has a lot to contribute to canting keels and perhaps to low aspect fixed keels as well.”

Come On Doug!!! You’ve never even built or sailed the thing.

Please, don’t make performance or breakthrough assertions for concepts that aren’t even tested yet.

Will isn’t making the kind of claims you are and Bantock never made your kinds of claims for the as yet also unbuilt F100.

You’ve put forth your idea, now build it, prove its faster, win some races and then start bragging.

Roy, you bring up a good point about the US1M rules.

When I read the rules for no movable keels, I read that to mean that the entire keel was not allowed to move. I had not considered that parts of the keel would also not be allowed to move under that rule. It doesn’t seem clear to me if this is legal or not.

As far as movable ballast, this is also a grey region. Clearly the intent of that rule is to not allow a boat to establish additional righting moment or adjust the trim by moving the CG of the boat by shifting ballast. Since the CG of the wings stays in the same place as the wings rotate, there is no shift in either righting moment or trim. So this idea complies with the spirit of this rule. but since the wing is stainless steel which is heavy enough to be considered ballast, and since it does technically move, this may be considered moving ballast.

I will submit a question to Jim regarding both of these issues and ask for a ruling.

If he does rule against the idea, then I will still proceed with my design and use it to evaluate the conditions where wings are beneficial versus detrimental. Then I will build two additional keels - one with wings and one without - that I will use for competition.

Jim is usually very quick with a response to questions like this. I will post his answer when I recieve it.

  • Will

Will Gorgen

Just a note to give a quick overview how the kFOIL? will be applied to canting keel models. There will be more on this soon under a new topic:“Application of the kFOIL? to rc models”.
But for now: the kFOIL is mounted either in the bulb as shown in Will’s renderings or under the bulb and is connected to a shaft running up the fin. Heres where the difference between a kFOIL? equipped boat and some “normal” canting keel boats comes in: the module used to provide a watertite canting keel will not work since the shaft runs up the fin and must be accessible to the inside of the hull. So what has been developed over the last two months is a 100% watertite canting TRUNK that the keel fin is inserted into.(The trunk also eliminates the characteristic “bump” seen on the bottom of many canting keel boats in way of the keel fin/strut.) This trunk is attached to the winch/servo that moves the keel and is designed to be canted 55 degrees. The trunk is made in such a way that a micro servo can be directly attached to it and can then be hooked directly to the shaft that moves the kFOIL?. Another option which will be available via a sketch before long allows fully automatic non- radio controlled deployment and retraction of the kFOIL? by simply moving the keel. It can be set up to automatically deploy/retract the foil at a specific preset angle on either side.
More soon; this is just to give some idea how the system is physically set up in a boat.

Doug Lord
–High Technology Sailing/Racing

As long as you are going to start yet <u>ANOTHER ???</u> thread for this <font color=“red”>(what’s wrong with keeping <u>ALL</u> your data under one [1] topic called kFOIL? Do we really need yet another thread on moving keels?)</font id=“red”>

I would renew a request that was made and promised last December (2003) - to post photos of this newly developed water-tite trunk.

Per your quoted post:<blockquote id=“quote”><font size=“1” face=“Verdana, Arial, Helvetica” id=“quote”>quote:<hr height=“1” noshade id=“quote”> “So what has been developed over the last two months is a 100% watertite canting TRUNK that the keel fin is inserted into.” <hr height=“1” noshade id=“quote”></blockquote id=“quote”></font id=“quote”>

Of course if this too is just more hot-air claims, I understand your reluctance and inability to post photos of yet another “idea”. It’s OK to remind us you don’t have a digital camera, you don’t know you can buy a 1-time-use camera at K-Mart/WalMart for under $4.00 and you didn’t know the store will both process and post your photos in digital format on the web.

<center><font size=“1”>[ watertite keel module; announced development March 4, 2004 ] </font id=“size1”></center>
<hr noshade size=“1”>
<font size=“1”>sorry - this little note makes it easier for me to find relative posts to this thread in the future. Someting else to add on to the monthly update list for April.</font id=“size1”>

The new topic, when it is ready will be a topic that will help people working with canting keels/canting masts to understand -in detail- how the thing is setup ,installed and operated. I will humbly ask the Moderator for assistance in maintaing posts “on -topic” so as to create as detailed and complete a resource as possible for people to use this new technology-- for free.

Doug Lord
–High Technology Sailing/Racing