Downwind foil with assist

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KayakDoc
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Downwind foil with assist

Post by KayakDoc »

Anyone here doing downwind(er) foil board stuff? Also any foil assist? I have returned to the area (maybe for a while) and the shift down on the Gorge to paddle foil on narrow downwind profile boards with foil assist ticks a few boxes for me.
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Re: Downwind foil with assist

Post by winddoctor »

I'm hoping to start dipping my toes in DW this winter. I'll be working on it without foil assist but that seems like a great way to go initially for sure. I plan to start working on flat water paddle ups, paddling in choppy conditions/small surf for balance training, then moving on to short DW runs as skills get dialled. There are others who have gear locally already and are poised to start soon too. Exciting times!
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Re: Downwind foil with assist

Post by smartang »

If we had a gorge here we'd all be doing it already as well. Lake/inlet swells don't really have enough swell period on most days to let you glide. It'll be mostly a downwind pump, which is great training.

I've found it difficult to make the transition from flat water paddle ups (which I can get 9/10 now) and lake/inlet downwind pumping to heading out on a 30 kn San P to CB run in overhead mixed swell. It's also dark, grey, raining, orca hallucinations... My legs get cooked just balancing for a few attempts. At that point you really need to sit down on the board for a few minutes and let the muscles recover. But it's spooky out there by yourself, regretting winging 3km out and packing a wet wing down.

A foil drive would make all the difference. The board really doesn't matter then, could be a large wing board so you'd save the 3-4k investment in a barracuda. Guaranteed pop up every time, and easy taxi out to the good bumps.

I did buy Marty's faux drive kit, which is designed by Shaggy I believe. Worked to get my razor 980 on foil no problem. But haven't been using it since I figured out how to paddle up in the flats. And trips to San P are so hectic with 3 little ones in the van I can't afford the setup time for an assist. $500 if you or anyone is interested in playing with assist on a budget.
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Re: Downwind foil with assist

Post by KayakDoc »

Thanks for the responses. The comments about the downsides when down winding resonate. Also, what Vancouver Island and Maui have that the Gorge doesn’t are the large ocean swells out in the exposed channels. When yeahmon and I did our first kite downwinders from Jorden River to Victoria we spent a lot of time in those swells. When I lived in Maui it was the same. Not many people out in Juan De Fuca then or now, but a lot more in the off shore Maui channels now. Yeamon and I had to work out the kinks and make some adjustments, but it was super fun out there. I built a high volume downwind board and a 4 piece break-apart carbon kayak paddle that secured to the front of the board so I could deflate the kite and paddle in when the wind died. The Georgia Strait runs where less of a challenge, but both sides of the Island had too much variation in the wind from beginning to end, making kite size choice difficult. It was best to put up as much kite as you could and deal with the windy spots and be happy there was enough to get you home when the wind became very light. Those downwinders were so much fun, although a few of the negative comments on the BWD site were enough to end our logging what we had done. I hope enough people have begun trying some of these that there is a reemergence of the stoke for a revisit, especially as a bunch of technologies are beginning to emerge and intertwine.

Namely; the new downwind foil boards look a lot like the board that Adam Koch designed and built on Maui. This must have been 10 years ago. The hull was super narrow, but it had platforms above the water line for standing on so you could hike on either tack. It didn’t gain traction, but I think now it would work for down winding, especially with dual foils, one on each side.

There is a new class of foils that are just beginning to emerge; modified super cavitating foils are very fast, but they are seeing updates to allow for initial lower lift off speeds. The upper speeds are insanely fast, but at least the speed range is increasing. This is where the foil assist would help. Getting the speed up to the lower end where the foil could kick would be immensely helpful.

Now for the blasphemy part; I never really liked the SUP stuff. I have always enjoyed kayaking more than canoeing. Mostly from my whitewater background. There is a lot more stability when sitting on your butt vs standing and a double bladed paddle generates more continuous power.

A friend in Maui (Sam) has developed a pocket wing. I believe there is a retrieval issue under full power, but that will get sorted (maybe it already has). I think this could replace a full kite setup, but still use the wind.

The new BLDC motors with VESC controllers and maybe even an Arduino to make some high speed efoil adjustments is also really fun technology that has been a joy to incorporate into some things I have been building. Even the lithium battery packs are generating a walloping amount of discharge. The Chinese technology from Flipsky has been first rate, at least for me, and is so much less expensive than the present efoil stuff here in North America.

It seems like all the pieces are laying out in front and the time might be right to bring them all together. A pocket sail, with a stable sit on board, high speed single or maybe a side by side, double, semi to super cavitating foil, with foil asset to maintain foiling that would allow for wind, power or efoil that could make for some fun long distance touring.

Maybe not. Just curious if anyone else is thinking along the same lines.
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Re: Downwind foil with assist

Post by more force 4 »

Such an interesting post Kayakdoc! Its fascinating to see the developments of free thinking even if I'll likely never be able to participate. Going outside of the kite/wing world and adapting Moth technology that https://www.sailingscuttlebutt.com/2015 ... oundaries/ was doing is really interesting, thanks for that, and I'm looking forward to checking these new downwind boards and the assist. I assume the assist is mounted high enough that it clears if the foiler can generate more power either from pumping or wind? And you don't need a weighty battery if its only for occasional assist? Sorry you stopped posting the downwinders due to criticism, I always enjoyed reading.
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Re: Downwind foil with assist

Post by KayakDoc »

Hi, More Force 4,
Thanks for the comments, questions and especially the kind mention of previous posts. It helps. Good find of the Adam Koch interview. It brings back a lot of memories. Incorporating some of that old design with the new downwind foil board hull shapes and a few additions (the wings may need to be outriggers so the paddle can be inserted close to the main hull) and I think an off shore downwind paddle/surf/foil/wind board will emerge.

You are right about the foil assist living mostly above the water surface. Battery size is also an interesting question. The style of prop and what motor to match it with is crucial. Everything is related to power; generating, expending and recharging. Prop shape and size is determined by wattage input and output. The BLDC motors generate a ton of power for such tiny motors. The VESC (Vedder electronic speed controller) allows for easy programming of some very sophisticated parameters. Because we are traveling through the air at high speed the motors have braking power generation programability which recharges the battery on the fly. If the prop is turning in the wind the wattage harvest can be significant. The motor gobbles power when under load and can generate power when turning while not under load if the prop selection is correct. They become wind generators. All that paddle and kite power can easily recharge the battery. Solar cells built into the deck can also help….a lot. Smart and efficient charging on the water keeps the battery weight down and the power available for much longer sessions. Those long downwinders can gobble up a lot of time out there.

Lots of other considerations, but a lot of it is known and ready to be epoxied together.
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Re: Downwind foil with assist

Post by KayakDoc »

The first 60 seconds of this video demonstrates the pocket wing. Another piece of the downwind offshore project. Sam is planing to produce and sell them through his Maui company Five-0 WindSports.


https://forum.progressionproject.com/t/ ... ts/2469/31
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Re: Downwind foil with assist

Post by KayakDoc »

Another piece!

I have been thinking about how to get the weight of the solar cells down to a usable level, generate enough power and be incorporated onto the deck of the downwinder board. It looks like it might be available soon. I might be able to just print the damn thing onto a layer of fiberglass and then epoxy onto the deck as the outer layer. Fun stuff!

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Re: Downwind foil with assist

Post by smartang »

I wonder how small of a pocket wing we could get away with if using a barracuda sup? Could be a life saver. Would also like a design that minimizes all those lines.

Hopefully someone comes up with plans so we can repurpose all those 15 year old kites.
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Re: Downwind foil with assist

Post by KayakDoc »

Regarding repurposing kites. I was thinking about using my 19m race kite as an awning on a trailer I rebuilt;
Trailer awning.jpeg
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Re: Downwind foil with assist

Post by KayakDoc »

A note about this project. The thing that ties this whole project together is a new design of hydrofoil. It is a super-cavitating foil capable of operating at sub cavitating speeds.The design and the prototypes exist. The rest of the stuff has already been built and used in other projects. The boards, the batteries, the motors, the ESC’s are all available and are fairly easy to build or buy. It has been easier to build recently because of supply issues, but that just forces you to think and design around the difficulties. Putting them together is not too hard. There are always stumbling blocks during construction and implementation though. Recently one of the biggest issues I had was with the VESC open source software. When compiling motor parameters for a VESC controlled BLDC the compiler had a glitch that I really had to sweat out. When loading motor parameters you have to write each new configuration before moving on to the next step. There was a glitch in the VESC code that rewrote one parameter from a single page to the next, essentially rewriting a single line of code. It really screwed up the ESC software. The motor would run, but poorly. It took a while to catch it, but after I did the motor ran perfectly every time. I mention this in case any of the WIG builders are using VESC to control their BLDC motor builds and are finding a glitch in loading and running PWM signals. It took me three months to find the problem. It sucked. I sent the problem and solution to VEDDER. I mention all of the above because I know that this downwind foiling paddling device can be built and used. I am just not certain if now is the time. Odd!
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Re: Downwind foil with assist

Post by yeahmon »

Hey Phil , great to hear your on to a’ new dimensions as usual with you , ahhhh yeah those downwinders we did, dreamy indeed, last one I attempted was ross bay to sidney , ended up on Darcy , wanted to complete Jordan River to sidney , anywho great your in town , what’s your number love to call ya
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Foil assisto. Sounds choice for big mother run
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KayakDoc
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Re: Downwind foil with assist

Post by KayakDoc »

Hey Kenny,
I will give you a shout. I remember you telling me about the Ross Bay to D’Arcy trip. I also tried to do Cook Street to Sidney but had to come ashore at Mount Doug Beach. We keep running into the “round the point” weather transitions. You and I aways had a challenge after Race Rocks. The wind just always wanted to die there and once we were past Race we were committed to a long way in to Victoria. The same when rounding 10-mile point. You have to commit to leaving Vancouver Island trusting that often too light wind in Harrow. I think a foil assist with the right foil and paddle-board combination could solve a lot of the issues we encountered.
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Re: Downwind foil with assist

Post by KayakDoc »

Is anyone on this site using the Triton X-1 mono-wing (for winging) or the T-1 mono-wing (for kiting)? I saw the X-1 in Stevenson on the Gorge last month. I ask because when I first saw it I thought that the design was backwards. It looked to me as if the front of the wing had negative lift and the rear of the wing had positive lift. I was manhandling it while kibitzing with Jim Stringfellow. He had received it the week before and had built a mast interface for it and had a couple days on it and had just modified the interface again to move the wing quite far back on his wing foil board. I mentioned that I thought it was designed and mounted backward and upside down. He laughed and accused me of only ever riding foils that I personally design and build. After thinking about it overnight I began to realize that to remove the fuselage and the rear wing you still have to somehow stabilize the foil. In hindsight I began to surmise that they may have done something quite smart. They may have built a canard with the negative lift at the front of the wing and the main, positive lift at the back. Anyone with any experience of the X-1 or T-1? If so, any experience with previous mono wings and any difference between the old and new? I might just be coming up to speed with mono’s, but if what I suspect I am seeing is true this is a smart way to remove the fuselage and its inherent hinderances and yet still have a balanced foil. Curious!
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Re: Downwind foil with assist

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