I’ve been making fins for over 35 years and your statement, I quote, “I’ve been doing some research on fins and for what I understand there has been very little changes in the past 50-60 years.” reveals a very shallow job of research.The fin applications and combinations of the 1960’s bear small resemblance to those of the 21st century. An evolution has taken place that you have missed. Get back to work. There is an enourmous amount of disscussion on fin properties and the theory there of here on this site. When I comes to tunnel fins I step aside because producing an effective foil on one would be far to complex for me to tackle. Whacking of a piece of pipe and using a semicylinder from it somehow falls short of my idea of what fin dynamics is all about. If my words seem cryptic don’t take them to heart just consider what I have to say and do what’s next for you.
I don’t personally know much about the theory of fin design… and I’ve never used a turbo tunnel. However… maybe it’s just where I surf, but I’ve never seen anyone who could actually surf well who used a turbo tunnel. Personally I don’t see how the relatively crudely molded ones could accomplish much; I have no urge to try 'em. Maybe if some guys like Larry and Chip got together and bashed theory and practice together for a couple years they’d come up with something that ‘takes surfing to a new level of noseriding’. But for now I can’t imagine it helping anyone’s surfing much.
And based on the tone here…I would say…HMMMM…hello Roy again!
Nice way to interject yourself…Create an annonymous ID and start a thread as someone asking a question, so you can create an annonymous ID and answer…but ya just can’t help letting your pesonality come through.
Sandman…if you are truly someone new and not R-- S------ then my humblest appologies…but I doubt it.
Larry that old tunnel is crazy! That is a radically different concept than the tunnels I’ve seen (only the turbo tunnel type). Trippy. Foiling must be a hassle. Turning must be weird… How does that kind of fin feel in a sharp turn? Does it have a super consistent feel throughout a turn (like as the board banks and comes onto rail)?
edited, I’ve looked through the site. Too quick a response. lol
And based on the tone here…I would say…HMMMM…hello Roy again!
Nice way to interject yourself…Create an annonymous ID and start a thread as someone asking a question, so you can create an annonymous ID and answer…but ya just can’t help letting your pesonality come through.
Sandman…if you are truly someone new and not R-- S------ then my humblest appologies…but I doubt it.
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That was not nice…
You should learn to give the benefit of the doubt.
No good to appologies and at the end continue to doubt.
If you have anything against Roy, that’s your problem…not mine.
This is my first post here, and to be honest, I didn’t like the way you conducted it.
I thought I could learn someting here, but seems there are other issues more important for you people.
Bob “the Greek” Bolan gave us this one to get our impressions, sort of a GT manta shape with the tunnel. There’s some technical merit to the tunnel in that there is less surface area inside than outside. This creates a pressure differential which can effect turning sensitivity, use of a shorter fin, and other things.
One area you may want to look into is the empirical study of fin-turning application in nature done by Greenough, and others.
In fact, now that I think about it, some hard science research done on tuna led to a NASA patent, but not without another genius applying it to surf boards first (See MVG’s).
It seems to me nature is a great place start, and I mostly feel this way based being directed to look to nature by some outstanding, as much as one can be in the surf world, in the field. Thus most fins still look like something you could cut off an aquatic, or airborne, animal. If a tunnel fin were some “advancement” then why didn’t god/nature make a tunnel on the creatures of the sea???
No a surfboard isn’t a creature in nature, however I see what Taylor is saying.
If a person wanted to study things like, speed, movement efficiency, agility, etc. as it pertains to something passing through water…in this case an ocean…the perfect starting point would be to study the creatures that have evolved within that medium for millions of years.
This would certainly give you a baseline comparison for any fruther development or study.
The fastest and most agile creatures in the ocean are vastly superior, in those certain areas, than anything man has been able to come up with.
So IMHO, those studies are quite relevant.
They may not be applicable in their entirety…but still relevant.
But that is just my oppinion.
Oh…and I am absolutley positive the “Big G” is a surfer…or else why would 3/4 of the earths surface be covered in water? LOL
However, there is one creature created by man and not God: the “mulato”.
We have a saying: Deus criou o Homem e o Português criou o mulato.
OK back to surf…
Fins does make sence, but why do we have to go after the sence?
Why not break the rules?
After all, the rules were made to be broken.
I think tunnel fins is an interesting way to see things.
Nothing like giving it a try.
I think I might do it in my next project.
Even with the correct foil profile, I have doubts that it will create lift because it’s round and not horizontal like the plane wing.
All forces are ecocentric, therefore (in my mind) they will cancel each other in the opposite way.
If it would be a box type and the bottom having a horizontal proper foil I could picture in my mind high pressure and low pressure forces creating lift. But then the sides of the box would create friction and dificult to maneuver.
Another type I can forsee is 2 inner curve fins like the manta has. This is only theory but could result.
