Hi Roy…
Some interesting hoop foil design discussion on this site…
http://www.foils.org/sailbord.htm
Cool
Interesting.
Tunnels, hoops, parabolic foils. . . . . . all those curved wings make turning easier than with straight wings !!
Are you planning any more tunnel/hoop finned boards John ?
!
Hi Roy -
I always seem to have something on the drawing board or in the works. Not that it applies directly to surfboards - this hoopfoil boat design has always caught my attention…
wonder if they would work on a hull?? any thoughts…?
Hi Matt -
I’m not even sure that everybody can agree as to what a “hull” is. I assume you mean something with a mostly rounded convex bottom like a Liddle?
The paipos I’ve made with hoop fins both had wide tails with single concaves running through the back. One of them had a reverse rocker in the tail as well and has been reported as being pretty fast by the owner.
Although I could fit the removable hoop to a stand up fish, I never did get a chance to try it. It broke off after the owner ran it into a sandbar… never to be found. 
In any case, I have no idea how a hoop would work on a hull. Roy Stewart has far more experience with hoops on stand up boards. Maybe he’ll post his thoughts on the subject.
dear mr. mellor ,
the leader has contacted me via my foil hat to request that you kindly desist from posting this photo of my spaceship on your earthlings website .
[we are wanted on six planets , so publishing this will cause the intergalactics to easily trace us]…
regards
zaphod beedlebrox
hoop concepts?
more …
[ for those wondering …it’s kinda an Aussie tradition to "take the piss’’ [out of]* free thinkers and artistic / creative types … happens to ME all the time !! [I like Roy’s work , REALLY !]
cheers ,
ben
- "taking the piss"out of someone = making fun of them , or their creations …
Yeah - Colani is a genius/nutcase. Check his train locomotive concept model and boat design!
From my vast archive of round thingies which move. . . …
In case you are wondering whether it’s a boat or a plane, here’s a clue: it’s a plane !
There is a big difference between tunnels which are completey immersed in the flow, and surface piercing hoop hydrofoils, because with the surface piercing ones the water flow isn’t contained.
Anyone want to hear Alvin and the Chipmunks singing “hula Hoop” ?
Quote:
From my vast archive of round thingies which move. . . …
In case you are wondering whether it’s a boat or a plane, here’s a clue: it’s a plane !
There is a big difference between tunnels which are completey immersed in the flow, and surface piercing hoop hydrofoils, because with the surface piercing ones the water flow isn’t contained.
Anyone want to hear Alvin and the Chipmunks singing “hula Hoop” ?
…and ,
is this a movie you made , Roy ?
Possibly, can’t remember, one has made so many movies. . . .
…well, they definately won’t be able to use THAT photo in an ad for Virgin Airlines , WILL they ?!
Hi Tom,
I have been working on straight wings for the past 2.5 years.
All science based designs but with my feet as the final judge and executioner. ( i.e. if it didnt '' feel '' right , it got the flick )
60 full prototypes, marine ply, aluminium, polcarbonate, polypropylene, carbon fibre, kevlar, ventilated, flat-plate, taper, ellipse, cambered, step-hull, Xfoil, Glider3D, Winfoil, NACA, NASA, and a host of net sources Ive forgotten.
I have found that flats give you qualitative results and feedback, whereas curves reply with a muddled generalised approximation of a ballpark response, because a fin or foil, ( say a semi-circle) that covers 180 separate angles, is going to respond in all 180 directions, natch?
Can you tell me where curved wings are superior?
I might be heading in the wrong ( straight ) direction,…again.
Thanks, Brett Curtis. spuuut@hotmail.com
Quote:
Interesting.
Tunnels, hoops, parabolic foils. . . . . . all those curved wings make turning easier than with straight wings !!
Are you planning any more tunnel/hoop finned boards John ?
!
Hi Spuuut,
Half round tunnel fins are low on drag (no tip turbulence) and a give perfect, vice free response.
Are you making straight wings for surfboards?
Have you used any half round fully immersed tunnels on surfboards ?
PS I prefer wings which work unobtrusively, so that the board feels just like a normal board, only faster and with more drive.
What are you wanting from an underwater wing ?
Hello John. Inflatables and hoops make for a interesting day. Glad to see the spirit of Swaylocks is alive. Thanks for the links - some interesting stuff. Patrick
Hi Tom, to answer you questions and add to your comments:
" tip turbulence" is also virtually nil on flat or ‘generally flat’ wings with an elliptical planform or tip such as the Spitfire airplane and nature provides many examples of same on birds wings , fishes fins and dolphins tails. So Im happy to use that precedence.
Straight wings for surfboards? With the foils I have at the moment the whole of the ‘craft’ to which the foils are attached becomes airborne hence the style of ‘craft’ and its design become irrelevant. So it can be applied to anything that floats.
I see a similar theory being used with the hydrofoiled craft used for tow-ins.
What I am wanting from an underwater wing is to develop an applicable system that will progress any water board higher, faster, further. (Nothing similar to a normal board.)
I think if I can make that, people will want it. They will want to try it, tame it and ask for more.
Regards, Brett Curtis. <a href="mailto:spuuut@hotmail.com" class="bb-url">spuuut@hotmail.com</a>
Hey John,
How does that thing I posted ride?