I’m sure you have all seen the videos of Laird riding that hydrofoil toe-in board.
Here is my question. Is it possible to build a paddle-in board with a big winged fin that can generate enough lift to raise the board – and rider – out of the water?
Has anyone ever dabbled with this?
Yes. Look for surffoils’ posts. You’ll see what he’s all about.
How would you trim down the line if your foils were only half-in though? I was wondering about this exact thing just this morning. I’m all about seeing the video if it works.
How would you trim down the line if your foils were only half-in though? I was wondering about this exact thing just this morning. I’m all about seeing the video if it works.
I imagine that your foils would have to be wider than your board to fit in the pocket. What about having two foils? One cannard, up in the front like a hammerhead, and one in the middle to back region. That might add some stability, and provide more lift. I’m not sure how you would turn without a rudder, though.
I’m thinking that for it to work you would have to be able to generate enough speed at the drop-in phase to lift you up onto the foil(s),before turning into the wave.
I dunno.
Um. You done with that wooden board then?
Um. You done with that wooden board then?
I’m just daydreaming right now. My wife and I have this weight loss challenge going on right now. My goal is to get below 195 lbs, and then I get to buy wood for my next board. I started out at 210, and I’m now at 199. It won’t be long now!
Here is something else I have been dreaming about lately. I’m not sure about the bottom contours yet. It would be nice to see an alaia up close sometime.
Swied,
Hmm. I would like to see the avatar board without its appendage.
I drew one of them things too, but mine’s hulled out, kinda. http://i118.photobucket.com/…ula.jpg?t=1188276780
I had belly in mind for about 2 feet somewhere in the middle. Beveled rails, thin, but probably not kill-you-if-it-hits-you-thin.
Mine might even have some long low keels going back toward the corners.
I’m sure you have all seen the videos of Laird riding that hydrofoil toe-in board.
Here is my question. Is it possible to build a paddle-in board with a big winged fin that can generate enough lift to raise the board – and rider – out of the water?
Has anyone ever dabbled with this?
Since you didn’t specify how the board is to be ridden, here’s a picture of the prototype of a paddle-in hydrofoil paipo board (seventh in a series of such boards and first ridden in 2002). The details of the full-featured version (which is presently under construction, along with the tooling) can be found at the US Patent Office (US-PTO# 7,144,285).
http://www.uspto.gov/patft/index.html
Like an aircraft, it turns by banking the board (which requires minimal effort).
The design objective was maximum maneuverability (with minimal loss of speed) – which, as with an aerobatic or air combat aircraft, means minimum stability. The weak stability means that probably it cannot be ridden in the standing position (evidence: several persons who have ridden it said in advance that they were going to try standing up, but so far not one of them has actually tried to do so).
The optimization of the triad of stability, maneuverability, and speed can be altered by changing the foil and strut dimensions and configurations, but changing one affects the other two. In particular, achieving more stability would generally reduce maneuverability and speed potential. Part of the loss of maneuverability would be associated with the new configuration, but in addition, the standing position (vs riding prone) increases (substantially) the moment-of-inertia about the roll axis, thus resulting in a slower entry into, and exit from, a turning (rolling) maneuver.
The full-featured version has active, rider-directed controls which are expected to further enhance maneuvering capability while at the same time providing greater control. These controls would not be available to a standing rider.
[swied] (and anyone else in the San Diego/North County area) You’re welcome to try the board for yourself.
I'm sure you have all seen the videos of Laird riding that hydrofoil toe-in board.Here is my question. Is it possible to build a paddle-in board with a big winged fin that can generate enough lift to raise the board – and rider – out of the water?
Has anyone ever dabbled with this?
I don’t know about with surfboards…but if they do start experimenting they should have a look at what these folks are doing- the International Moth sailboat class. These little boats get up and plane with very little wind.
Swied,
Your alaia shape looks good. Could probably go thinner and narrower though, it doesn’t have to float you. A cheap but fun prototype can be made from redwood fence boards. Just pick through and find some good boards. Don’t overthink it, just make it.
Also I belive Tom Wegner’s brother shapes alaias in So. Cal.
-Brian
Markup : That’s exactly what I was look for! Very cool design. It looks fun to ride. I would definitely look to try it out. I’ll send you a PM.
hi Swied ! nearly SIX YEARS on , but … better late than NEVER , eh ?! click here I’m just waiting to see the video that brett’s mate Adam got of this recent day , now … … enjoy ! cheers ! ben
… brought across to this thread from the boogie hydrofoil thread , as it relates to shortboard surfing …
Re: [Surffoils] Shortboard Hydrofoil video.
my question is / would still be … what is the [smallest ] sized SINGLE strut and wing , that will still lft a 60kg rider out of the water , on a waist to chest high day?
Beachbreaks here are long , have shape , and a bit of push to them , and I would be wanting to ride them mid-tide [for starters !] also bgsurfer, your “40 %” [up the board ] guideline / thought, on my previous question on the single strut placement … …sounds about ‘what looks okay’, on the board that I have in mind [can’t post any photos here, unfortunately, but the 2ndlight thread lets me in, so I will endeavour to post them THERE, and possibly link to here]
THIS board is a Gary Dorrington ‘Stinger’ , a thruster … set up with three sets of fcs plugs at the moment , but my brother [whose board it is!] said it’s okay to finbox. [hoorayyy!] just need to get a 12 to 15" box for it , next … the board’s dimensions are … 14 3/4" x 6’3 x 20" x 14 3/4" x 3" [!] […swallowtail , 7" tip to tip] The stinger / wings are at 17" up from the tail …
…to be continued … cheers ! ben
hi ‘bg’ !
so , putting that into fin measurement / design terms , now …
[if you mean 150 square inches area for a 60kg rider , from your above witings ?]
what depth and width strut ? and what width wingspan [tip to tip of ‘winged bit’ ] , would that roughly translate to , please ?
The rough sizes , that I am presently contemplating , [going on looks , not ‘science’ or ‘formulas’ ha ] , at this stage are … Strut … 5" base , 9" depth , 1-2" rake [maybe , or maybe upright??] 'Winged ’ part … 13-14" , tip to tip [ in order to fit inside the rail to rail width of the test board ] . And , maybe 4 - 6 " , from the leading to the trailing edge , of the winged part. Using your ‘formula’ / guideline? mentioned elsewhere of " 40 % of the length of the board " , for placement , on the board pictured , this would place it [?leading edge ? back edge ? of strut?] at 30" up , from the tail pod.
The wing of the stinger , is 17" up from the tail … So , with 'at least ’ the 15" finbox you pictured , there would be TEN inches of fore and aft movement , with the 5" base strut[s] that I have in mind. Which will still leave the trailing edge of the STRUT of the foil , at least 13" in FRONT of the wings , if the REAR of the 15" finbox is placed 30" up from the tail pod . Yes ? …does that make sense ?
I definately want to make a FEW different struts , and wings. Ideally , if the parts were somehow interchangeable, it would help things along nicely …I wonder [aloud] if some kind of tight-fitting slot arrangement , would be STRONG enough to hold , with the pressure on the winged part ? I also liked how the WAVEFIN that I tried out , had the cog-type arrangement option , for altering the ANGLE of the winged part … [ I wonder … dot , dot , dot … 
]
W E L L L L … there is only ONE way to find out , eh ?! …
cheers !
ben
p.s. - edit… ‘bg’ , if it’s okay with you ?
I will try to move the last few posts of ours to Swied’s old " Paddle-in hydrofoil board ? " thread … as they are relating to paddling in and STANDING UP on a surfboard , as opposed to a boogieboard hydrofoil .
From Brett’s shortboard hydrofoil thread. And yes, based on Brett’s formula you need a foil with 150 sq. in. of surface area.
Fins,
Ignore those who do not offer usable input. I believe the waters are uncharted for all of us in the case of box mounted, “paddle-in” hydrofoil surfboards!
If we had a rectangle 5" x 14", the surface area would be 70 sq. in. – still need another 80 sq. inches. Plus the curved tips make the area a bit less. To get an area estimate, you just need to fit rectangles, triangles and half/full circles into the foil template you have in mind.
A 10" x 15" rectangle = 150 sq. in. Your dimensions when multiplied must equal 150. To get estimates, divide 150 by one of the dimensions you are thinking about and that will give you the other needed dimension. That is, 150 divided by 14 = 10.71" – a 10.71" x 14" rectangle. By adding a tail stabilizer behind the wing, you can reduce the wing surface area by the amount of area in the tail stabilizer.
I do not believe strut dimensions will figure into the lift aspect. We need Brett to guide us on strut design and properties.
It is worth it just for the experience and experimental journey. More is learned.
thanks !
I was told to watch the dvd ‘project grizzly’ …[ anyone seen it ? ] because my apparent " lack of clue " reminded the person who made the comment , of the guy in the grizzly movie , apparently ? So , it might be worth my while watching it , eh ?! Uncharted waters for me , yes . Trial and error ahead , yes. Could be fun too, yes. Or could be a waste of time. At least , with a fin box , it will become a bit easier / safer …is my thinking . I can always take the foil out of the extra box , and ride it as a ‘normal setup’ , too , so I’m not sacrificing a board , if it 'doesn’t work ’ .
And … I will never know if it is worth pursuing , till I TRY it , I guess ! . Seeing Alex’s stoked face in those photos after his first successful [and documented proof ! ] attempt at ‘foiling’ , is certainly ENCOURAGING [ for me ] , anyway !
the question still remains for me , I guess . The mathematicians here ?? 150 square inches area = ? " x ? " x ? " , in terms of strut , wing dimensions ??
IS , say , a 5 " x 9 " strut , 14" wing tip to tip , and 4"- 5" front to back , adding up , or ‘close to’ , the " 150 square inches " of which you speak , please ?
…just so I have a ‘general’ idea of that , in fin sized terms …
[You see , being a ‘tinkerer’ , only … I have not made fins by ‘area’ , in the past … but more by …make them , and feel how they RIDE… [ as well as how they look too, I suppose ]
cheers guys
ben
Ben - since you have moved the conversation over here to this thread, I will delete the duplicate posts over on the other thread.
Hahaha… I started reading this thread today just because it was at the top of the General Discussion. About half way through I realize that most of the posts said “re: swied” on them. Wait a minute… I started this thread back in 2007. It’s been so long I completely forgot about it. I had to go back and reread everything. What the heck was I doing talking about my weight on a hydrofoil thread??? Anyhow… I won the weight loss challenge. I’m right around 180 at this point in time. It is much easier to surf without 40 extra pounds of fat on your belly.
It looks like Swaylocks has a bug regarding alerts on old posts. I get emails when someone replies to one of my recent posts, but this on didn’t generate any emails.
I have been following surfoils recent videos and really like what he has been doing. I may have to start going experimental myself. I like the idea of using a 15" fin box to support the hydrofoil(s). I am right in the middle of shaping a 9’ longboard. hmmmmm…
You might want to check out this hydrofoil thread at another forum also – started with body boards but has evolved to include surfboards now:
http://www.2ndlight.com/fusetalk/forum/messageview.cfm?catid=3&threadid=146169&enterthread=y