Micro Foiler Build

[The Wing Guy]

I have a 31' cat powered by a rigid self-trimming wing. So far, that has been working well. However I had a catastrophic failure of a Victron MPPT that fed both the battery and my electric propulsion motor with 86.7 volts instead of the usual 57.8 for a nominal 48v system. Fortunately the motor, the batteries and the battery balancer are all overvoltage protected. (Amazingly, the Victron has no overvoltage protection at all.) The motor would not, of course, operate until I got the system sorted out.

The episode got me thinking about electrical failures. Maybe it's a gray day, flat calm and my battery bank is depleted... and I am drifting toward some million dollar yacht. Wouldn't it be nice to have a backup motor. So I bought a tiny Suzuki 2.5 HP outboard. I started to think that the thing would sit at the back of my cat, possibly (probably?) never to be used. So I thought "How else can I use this?"

I have an ultralight pirogue that I have not been using. I have some airfoils that are of an OK, although suboptimal, profile and size to use as hydrofoils. They have adequate structural strength. It could be fun to zip around on flat water, so I am building a low rider: a foiling boat that flies at just 6" above the water. If I can find the right prop, I should be able to get it going about 20 mph (that sounds better than 17 knots). We'll see. If need be, I can add to flight height, but initially I think flying low is safer than flying high, given the experimental nature of this little boat. I'll practice crashing down from flight. I'm expecting that to be not too violent, but we'll see. In any case, working out the kinks under motor power will be easier to do than to learn to sail it and work out all the kinks at the same time.

I have a variety water states and wind to chose from, and can probably find (maybe) enough wind (with only small waves) to make this thing fly under sail. We'll see.

Do you think that having powerboat races on little foiling boats limited to say 2.5 HP would be fun? Would you be more apt to learn to sail on foils if the boat were closer to the water, and more docile than a typical wing foiler? I think that there could be a class of foilers that are easier to race and learn than the Moths. I'm thinking that there could be a market for a small boat that is as easy to sail as a Sunfish, but faster. This is all just wild conjecture, and I would not be the person to make a business of it. But it would be interesting to hear your thoughts.

 

[HelmutSheina]

Do you have any information on the wingsail available please Wing?

 

[The Wing Guy]

Do you have any information on the wingsail available please Wing?

Hi Helmut,
Here is a link to some info I put together for a post on LinkedIn. I have planned to develop a series of videos on the wing-powered boat, with the purpose of getting some similar boats built, based upon some IP used in the current boat. I am not quite ready to do that, so the LinkedIn post is a little premature. It was put together not so much to promote the wing-powered boat as to comply with the entry rules for the LiTime promotion challenge for their new motors... which, I think, are pretty cool, particularly because they come with wireless remote steering.

#goelectric #litimepower | Ken Fry | 25 comments https://www.linkedin.com/feed/update/urn:li:activity:7484430280263442432/?commentUrn=urn%3Ali%3Acomment%3A(activity%3A7484430280263442432%2C7485547819731230721)&dashCommentUrn=urn%3Ali%3Afsd_comment%3A(7485547819731230721%2Curn%3Ali%3Aactivity%3A7484430280263442432)&dashReplyUrn=urn%3Ali%3Afsd_comment%3A(7487308305015676928%2Curn%3Ali%3Aactivity%3A7484430280263442432)&replyUrn=urn%3Ali%3Acomment%3A(activity%3A7484430280263442432%2C7487308305015676928)

Feel free to ask about details re the winged boat. Some details: It is 12' wide when on the water (8' for the road) so is narrow for a 31' catamaran. Empty weight is 2500 lb with a design displacement of 3000lb. A winch built into the boat steps the wing. The wing has been up for months, through noreasters, etc, and is behaving well. It weathervanes without causing the boat to lurch around, so at least so far, there is no more need to lower the wing or reduce its area than there is to do the same thing with an airplane. The wing, when weathervaning, has less drag that the bare poles of a similar size sailboat. A

As you would expect, the wing has very low drag at low angles of attack, (there is no flapping, fluttering, flogging) so the boat can be sailed with any combination of motor power and wing power. The control levers for the wing are exactly the same type of levers used for the electric propulsion motor, but mounted so that they move athwartships instead of fore and aft).

I think I will get the paid version of Power Director for editing videos about the boat. A short video that I threw together to test Power Director is linked below. (It is watermarked, because I have not yet bought the paid version.) Looking at that little video may give you a sense for how the boat works.

 

[montero]

I have a 31' cat powered by a rigid self-trimming wing. So far, that has been working well. However I had a catastrophic failure of a Victron MPPT that fed both the battery and my electric propulsion motor with 86.7 volts instead of the usual 57.8 for a nominal 48v system. Fortunately the motor, the batteries and the battery balancer are all overvoltage protected. (Amazingly, the Victron has no overvoltage protection at all.) The motor would not, of course, operate until I got the system sorted out.

The episode got me thinking about electrical failures. Maybe it's a gray day, flat calm and my battery bank is depleted... and I am drifting toward some million dollar yacht. Wouldn't it be nice to have a backup motor. So I bought a tiny Suzuki 2.5 HP outboard. I started to think that the thing would sit at the back of my cat, possibly (probably?) never to be used. So I thought "How else can I use this?"

I have an ultralight pirogue that I have not been using. I have some airfoils that are of an OK, although suboptimal, profile and size to use as hydrofoils. They have adequate structural strength. It could be fun to zip around on flat water, so I am building a low rider: a foiling boat that flies at just 6" above the water. If I can find the right prop, I should be able to get it going about 20 mph (that sounds better than 17 knots). We'll see. If need be, I can add to flight height, but initially I think flying low is safer than flying high, given the experimental nature of this little boat. I'll practice crashing down from flight. I'm expecting that to be not too violent, but we'll see. In any case, working out the kinks under motor power will be easier to do than to learn to sail it and work out all the kinks at the same time.

I have a variety water states and wind to chose from, and can probably find (maybe) enough wind (with only small waves) to make this thing fly under sail. We'll see.

Do you think that having powerboat races on little foiling boats limited to say 2.5 HP would be fun? Would you be more apt to learn to sail on foils if the boat were closer to the water, and more docile than a typical wing foiler? I think that there could be a class of foilers that are easier to race and learn than the Moths. I'm thinking that there could be a market for a small boat that is as easy to sail as a Sunfish, but faster. This is all just wild conjecture, and I would not be the person to make a business of it. But it would be interesting to hear your thoughts.
View attachment 209617

However, I would suggest a slightly higher power output, e.g., 6-8 hp 2-stroke. And a minimum weight limit.

 

[Skip Johnson]

"Do you think that having powerboat races on little foiling boats limited to say 2.5 HP would be fun? Would you be more apt to learn to sail on foils if the boat were closer to the water, and more docile than a typical wing foiler? I think that there could be a class of foilers that are easier to race and learn than the Moths. I'm thinking that there could be a market for a small boat that is as easy to sail as a Sunfish, but faster. This is all just wild conjecture, and I would not be the person to make a business of it. But it would be interesting to hear your thoughts."

Yes I think it would be fun but suspect that a race to improve the motors would develop. ;-)

BTW I like your sail rig, brings back memories.

 

[The Wing Guy]

"Do you think that having powerboat races on little foiling boats limited to say 2.5 HP would be fun? Would you be more apt to learn to sail on foils if the boat were closer to the water, and more docile than a typical wing foiler? I think that there could be a class of foilers that are easier to race and learn than the Moths. I'm thinking that there could be a market for a small boat that is as easy to sail as a Sunfish, but faster. This is all just wild conjecture, and I would not be the person to make a business of it. But it would be interesting to hear your thoughts."

Yes I think it would be fun but suspect that a race to improve the motors would develop. ;-)

BTW I like your sail rig, brings back memories.

I just looked over your article in Small Craft Advisor. It looks like we may suffer from the same affliction: endlessly designing and building stuff. (We are also interested in very much the same sort of boats.) I love Nomad, and was sorry to read about its demise. Perhaps in a different thread, I'll relay a similar story or two. I am far along the spectrum toward rational (rather than magical) thinking, but several times have thought perhaps someone (my demonic angel?) really does not want me to build boats with wings. I have had a range of conventional sailboats, and very few things have happened with them that could not be traced to obvious bad sailing on my part.

About 15 years ago, I think, I built a shunting proa from a pirogue I had sitting around. A mast was canted from the ama, extending over the main hull. It supported an isosceles triangular sail. I came up with a reasonably slick system for adjusting AoA on two boards, that together served for lateral resistance as well as steering. The board sections were ogival, and the adjuster would angle both to eliminate leeway while operating at their best L/D, roughly. The tiller would then differentially affect them. The center of effort of the rig was on a line that intersected the center of lateral resistance, so that no heeling occurred. (Was it Bernard Smith?) It worked remarkably well, and sailing it in gusts without any affect other than accelerating was almost uncanny. If you have not done something similar, you should, if you have the energy and inclination.

(If you have windsurfed, you have probably experienced the ability to lift the board out of the water when you are hiked way out over the water.)

If LiTime sends me one of their motors, I'll prop it and the Suzuki appropriately, and see which one is faster on my microfoiler. The LiTime 2000 watt motor should have a shaft output very close to the Suzuki's. I'd be happy to see more electric motors on the water, and perhaps seeing them beating combustion engines would be a good promotion. Mixed combustion/electric competition would be fun, but the rules could be complex: Maybe just strictly stock engines/motors, unrestricted props, a minimum weight, and no restrictions on planing vs hydrofoils etc.

 

[The Wing Guy]

However, I would suggest a slightly higher power output, e.g., 6-8 hp 2-stroke. And a minimum weight limit.

There is already the Cocktail Class at that power level, so your suggestion is well-taken: there is proof that there is some interest. On the other hand, I remember, as a kid, wanting to build an 8 foot hydroplane, and as a kid, the engine was beyond my means. My Suzuki was about half the price of an 8 hp motor. A lower power limit would allow lighter boats, and so lower cost too.

Granted, I already have the Suzuki, but my cost for modifying the pirogue will be about $20 in epoxy and almost that in paint.

 

[montero]

There is already the Cocktail Class at that power level, so your suggestion is well-taken: there is proof that there is some interest. On the other hand, I remember, as a kid, wanting to build an 8 foot hydroplane, and as a kid, the engine was beyond my means. My Suzuki was about half the price of an 8 hp motor. A lower power limit would allow lighter boats, and so lower cost too.

Granted, I already have the Suzuki, but my cost for modifying the pirogue will be about $20 in epoxy and almost that in paint.

As a kid I wanting to add 50cc moped engine to my inflatable without transom .
But the first interesting observation of hydrodynamics was made on an electric toy boat that made cool water splashes because of the negative concavities at the bow.

 

[Skip Johnson]

I just looked over your article in Small Craft Advisor. It looks like we may suffer from the same affliction: endlessly designing and building stuff. (We are also interested in very much the same sort of boats.) I love Nomad, and was sorry to read about its demise. Perhaps in a different thread, I'll relay a similar story or two. I am far along the spectrum toward rational (rather than magical) thinking, but several times have thought perhaps someone (my demonic angel?) really does not want me to build boats with wings. I have had a range of conventional sailboats, and very few things have happened with them that could not be traced to obvious bad sailing on my part.

About 15 years ago, I think, I built a shunting proa from a pirogue I had sitting around. A mast was canted from the ama, extending over the main hull. It supported an isosceles triangular sail. I came up with a reasonably slick system for adjusting AoA on two boards, that together served for lateral resistance as well as steering. The board sections were ogival, and the adjuster would angle both to eliminate leeway while operating at their best L/D, roughly. The tiller would then differentially affect them. The center of effort of the rig was on a line that intersected the center of lateral resistance, so that no heeling occurred. (Was it Bernard Smith?) It worked remarkably well, and sailing it in gusts without any affect other than accelerating was almost uncanny. If you have not done something similar, you should, if you have the energy and inclination.

(If you have windsurfed, you have probably experienced the ability to lift the board out of the water when you are hiked way out over the water.)

If LiTime sends me one of their motors, I'll prop it and the Suzuki appropriately, and see which one is faster on my microfoiler. The LiTime 2000 watt motor should have a shaft output very close to the Suzuki's. I'd be happy to see more electric motors on the water, and perhaps seeing them beating combustion engines would be a good promotion. Mixed combustion/electric competition would be fun, but the rules could be complex: Maybe just strictly stock engines/motors, unrestricted props, a minimum weight, and no restrictions on planing vs hydrofoils etc.

My sympathies to your significant other if you have such; mine has endured a lot over the sixty years; but it's mainly been fun for both of us. I've never considered that some malignant force is opposing what I do but do believe that mother nature and murphy keep a close eye on what I do and will gladly correct misapprehensions in what I do. To wit you will probably never hear me proclaim something I've done as being "bulletproof".

Back to your thread, most of my wingsail work has been based on Dr. Elkaim's "Atlantis" for aerodynamics and Peter Worsley's circular cam sail control along with some guidance from the homebuilt aircraft crowd for tail volume coefficient. I will probably build a replacement for the original Bionic Broomstick once a couple of other projects are done. The magic that comes from a proa accelerating that's not experienced in other craft is addictive for sure.

 

[HelmutSheina]

There is already the Cocktail Class at that power level, so your suggestion is well-taken: there is proof that there is some interest. On the other hand, I remember, as a kid, wanting to build an 8 foot hydroplane, and as a kid, the engine was beyond my means. My Suzuki was about half the price of an 8 hp motor. A lower power limit would allow lighter boats, and so lower cost too.

Granted, I already have the Suzuki, but my cost for modifying the pirogue will be about $20 in epoxy and almost that in paint.

Turbo charge the two hp.

 

[HelmutSheina]

Hi Helmut,
Here is a link to some info I put together for a post on LinkedIn. I have planned to develop a series of videos on the wing-powered boat, with the purpose of getting some similar boats built, based upon some IP used in the current boat. I am not quite ready to do that, so the LinkedIn post is a little premature. It was put together not so much to promote the wing-powered boat as to comply with the entry rules for the LiTime promotion challenge for their new motors... which, I think, are pretty cool, particularly because they come with wireless remote steering.

#goelectric #litimepower | Ken Fry | 25 comments https://www.linkedin.com/feed/update/urn:li:activity:7484430280263442432/?commentUrn=urn%3Ali%3Acomment%3A(activity%3A7484430280263442432%2C7485547819731230721)&dashCommentUrn=urn%3Ali%3Afsd_comment%3A(7485547819731230721%2Curn%3Ali%3Aactivity%3A7484430280263442432)&dashReplyUrn=urn%3Ali%3Afsd_comment%3A(7487308305015676928%2Curn%3Ali%3Aactivity%3A7484430280263442432)&replyUrn=urn%3Ali%3Acomment%3A(activity%3A7484430280263442432%2C7487308305015676928)

Feel free to ask about details re the winged boat. Some details: It is 12' wide when on the water (8' for the road) so is narrow for a 31' catamaran. Empty weight is 2500 lb with a design displacement of 3000lb. A winch built into the boat steps the wing. The wing has been up for months, through noreasters, etc, and is behaving well. It weathervanes without causing the boat to lurch around, so at least so far, there is no more need to lower the wing or reduce its area than there is to do the same thing with an airplane. The wing, when weathervaning, has less drag that the bare poles of a similar size sailboat. A

As you would expect, the wing has very low drag at low angles of attack, (there is no flapping, fluttering, flogging) so the boat can be sailed with any combination of motor power and wing power. The control levers for the wing are exactly the same type of levers used for the electric propulsion motor, but mounted so that they move athwartships instead of fore and aft).

I think I will get the paid version of Power Director for editing videos about the boat. A short video that I threw together to test Power Director is linked below. (It is watermarked, because I have not yet bought the paid version.) Looking at that little video may give you a sense for how the boat works.

Thanks for the information.

I am working towards a project, but maybe two years from starting, and collecting info I encounter currently. Would you have more drawings or photos of your system you are willing to share please?

Re video editing, I have been using Linux based operating systems for over 20 years and find the Free and Open Source Software people of similar outlook to boating folk, and enjoy using their excellent software. Here is a list of free and open source video editing software in case one does what you want. 11 Free and Open Source Video Editors https://itsfoss.com/open-source-video-editors/

 

[montero]

Turbo charge the two hp.

Stock engines no powerhead tuning .

 

[The Wing Guy]

Back to your thread, most of my wingsail work has been based on Dr. Elkaim's "Atlantis" for aerodynamics and Peter Worsley's circular cam sail control along with some guidance from the homebuilt aircraft crowd for tail volume coefficient. I will probably build a replacement for the original Bionic Broomstick once a couple of other projects are done. The magic that comes from a proa accelerating that's not experienced in other craft is addictive for sure.

When I was developing the Windrocket (which went just short of three times wind speed... unlike my current boat, which is slow as snot) I talked with George Fekete, who with Newman (both at McGill) described the need for not just static but dynamic balance in a self-trimming wing system (in a paper from the 60's, I think). David Caughey at Cornell put me in touch with Ilan Kroo at Stanford, who gave me a copy of PANDA an early, simple CFD program he had developed. When Caughey made the recommendation I don't think he mentioned that Ilan Kroo worked on Connor's America's cup cat. I have felt very fortunate to get advice for these very generous academic people. David was instrumental in disabusing me of a number of misconceptions I had developed in the course of learning to fly.