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Extreme Dolfinism G2
- Thread starterREVAN
- Start date
Thread Status: Hello
, There was no answer in this thread for more than 60 days.
It can take a long time to get an up-to-date response or contact with relevant users.
It can take a long time to get an up-to-date response or contact with relevant users.
A little more effort than to do the same with a normal undulation - in part because I'm not used to swimming with just my ankles, so the rest of my body is more tense than usual. I don't think thats the best speed for the ankle technique. I'd call that a moderate cruise pace with moderate-plus effort - as opposed to moderate-minus with normal technique .
Sprint pace for me with my soft hyperfin is 11 seconds for 25.
There is a whole series of videos there with the Orca 1 vs my #3 Starfin. The upshot of those tests was that the hyperfin performed a little better. That, however, was the Orca 1 and a 37inch span. The Orca 2 has less drag, and different leverage - the one I have also has a 44inch span. I've not yet been able to get it into the pool - but I'm pretty optimistic that it will perform impressively.
I also just noticed your dolphin kick dive without the fin... That pretty much tells me your technique is 1200% better than mine :-o making it look so easy...
The small undulation dive you posted is the First ever I've seen that, to me, is a picture of what will come... Soon... I wanna make my long thought about x-20 modification right about now...
More to come soon
The small undulation dive you posted is the First ever I've seen that, to me, is a picture of what will come... Soon... I wanna make my long thought about x-20 modification right about now...
More to come soon 
Connecting to the lower legs is something I have considered, but from early on I decided that it is not an ideal solution and set out to avoid having to do that. The main reason for this is maneuverability. The ankles add a several degrees of freedom to the fin that are highly useful for in-water maneuvering with a monofin. Eliminate that maneuverability and you are now operating with one of the main handicaps that, I believe, was a significant reason for the Aqueon's lack of commercial success.
When attaching to the feet, there are two obstacles to overcome that the DOL-Fin architecture handles exceedingly well. One is the load and strain that the fin puts on the feet and ankles. The other is that the large angle rotations the ankle is capable of can translate to unwanted angle rotations of the fin blade that can degrade performance.
The Orca2 is a 3rd generation refinement for finding optimal metrics for ankle load and strain. It does a very nice job of creating a good balance for achieving both comfort and performance in a freediving monofin. Perhaps Fondueset could give his independent perspective on this, but I think it is acceptable ankle load for a beginner and totally comfortable for a diver that has the physical conditioning of a freediver who has been training. The Pilot is totally comfortable for a beginner and probably still comfortable for most people who have ankle problems that would prevent them from wearing other types of dive fins.
The DOL-Fin's patented fin suspension system takes care of the angle rotation issue. People often ask why there is only a mechanical angle limiter for one direction of the fin's rotation. The foot is against the tendon lock when forcing the fin down. On the downstroke, the pivot cannot be any closer than the knee, and ideally it should be further away still, in the core of the swimmers body. The rotation angles of the fin's support structure will be small compared to the amplitude of the translation. However, on the return stroke the ankle comes off the tendon lock and has a large amount of rotational freedom. A different mechanism for controlling the fin's angle-of-attack relative to the water is needed to efficiently handle this uncertainty of input conditions on the upstroke, and that is what the DOL-Fin system provides.
From Eric Fattah's video, shown back on post #188, you can see him doing what amounts to a calf lift, like baiyoke had shown in post #218. This results in large angle rotations of the fin's support structure (possibly in excess of 60 degrees). Without the DOL-Fin's robust angle control of the fin blade, this would not be an effective stroke to utilize for propulsion. If it were handled the same as in the downstroke, the foil would stall resulting in poor performance, and this would be considered an unviable fin stroke. The "magic" in the DOL-Fin system is to make all the different strokes and muscle groups viable for thrust production. Pretty much every little movement and muscle twitch the diver makes, even ones that are just intended to set trim or get comfortable for a freefall, result in some thrust being made at the fin blade that is proportional to the energy that went into the movement. Nothing gets wasted.
When attaching to the feet, there are two obstacles to overcome that the DOL-Fin architecture handles exceedingly well. One is the load and strain that the fin puts on the feet and ankles. The other is that the large angle rotations the ankle is capable of can translate to unwanted angle rotations of the fin blade that can degrade performance.
The Orca2 is a 3rd generation refinement for finding optimal metrics for ankle load and strain. It does a very nice job of creating a good balance for achieving both comfort and performance in a freediving monofin. Perhaps Fondueset could give his independent perspective on this, but I think it is acceptable ankle load for a beginner and totally comfortable for a diver that has the physical conditioning of a freediver who has been training. The Pilot is totally comfortable for a beginner and probably still comfortable for most people who have ankle problems that would prevent them from wearing other types of dive fins.
The DOL-Fin's patented fin suspension system takes care of the angle rotation issue. People often ask why there is only a mechanical angle limiter for one direction of the fin's rotation. The foot is against the tendon lock when forcing the fin down. On the downstroke, the pivot cannot be any closer than the knee, and ideally it should be further away still, in the core of the swimmers body. The rotation angles of the fin's support structure will be small compared to the amplitude of the translation. However, on the return stroke the ankle comes off the tendon lock and has a large amount of rotational freedom. A different mechanism for controlling the fin's angle-of-attack relative to the water is needed to efficiently handle this uncertainty of input conditions on the upstroke, and that is what the DOL-Fin system provides.
From Eric Fattah's video, shown back on post #188, you can see him doing what amounts to a calf lift, like baiyoke had shown in post #218. This results in large angle rotations of the fin's support structure (possibly in excess of 60 degrees). Without the DOL-Fin's robust angle control of the fin blade, this would not be an effective stroke to utilize for propulsion. If it were handled the same as in the downstroke, the foil would stall resulting in poor performance, and this would be considered an unviable fin stroke. The "magic" in the DOL-Fin system is to make all the different strokes and muscle groups viable for thrust production. Pretty much every little movement and muscle twitch the diver makes, even ones that are just intended to set trim or get comfortable for a freefall, result in some thrust being made at the fin blade that is proportional to the energy that went into the movement. Nothing gets wasted.
when you put it like that Ron the Orca sounds like a very versatile ingenious fin!!!
I believe it is.
I just came across this NatGeo show on DARPA from 2013 (video below). From the looks of it, the PowerSwim system (a modern recreation of the Aqueon) is still in action. This is the first I have heard on PowerSwim in several years.
I think the DOL-Fin tech has got these DARPA PowerSwim guys sooo defeated. Compare them for yourself and let me know what you think.
DARPA PowerSwim
DOL-Fin Monofin
I think the DOL-Fin tech has got these DARPA PowerSwim guys sooo defeated. Compare them for yourself and let me know what you think.
DARPA PowerSwim
DOL-Fin Monofin
PS - I cringe when I think about how much money they spent on this PowerSwim contraption. The initial contract was for $2.83 Million (of my taxpayer money). It is so frustrating!
DEKA (who was the contractor that made PowerSwim for DARPA) may have lost in terms of producing functional hardware, but they certainly won in terms of raking in $$$.
DEKA (who was the contractor that made PowerSwim for DARPA) may have lost in terms of producing functional hardware, but they certainly won in terms of raking in $$$.
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According to the video DARPA is open to any idea
I think your Pilot foil model has got potential, just add a pair of quick detachable self draining combat boots to them, so that troops can quickly detach from the foil, and run ashore.
And if DARPA isn't into it, maybe some other army is? - I bet they love your durable and affordable Pilot model!
Your free market products look miles ahead of that handy capping clumsy, huge, 'power swim'. Judging from the side profile swim along the tiles video, maybe you can estimate it's speed, I bed it's nothing remarkable. My guess it's a speed close to a scuba diver wearing closed heel long fins.
Oh and that shot with the diver wearing a loosely fitting camo dry suit, hilarious, having all that money spend on researching foils, drag and efficiency and then forget the most blatant drag inducing gear.
Maybe your character is not suited to work with this kind of folk?
I think your Pilot foil model has got potential, just add a pair of quick detachable self draining combat boots to them, so that troops can quickly detach from the foil, and run ashore.
And if DARPA isn't into it, maybe some other army is? - I bet they love your durable and affordable Pilot model!
Your free market products look miles ahead of that handy capping clumsy, huge, 'power swim'. Judging from the side profile swim along the tiles video, maybe you can estimate it's speed, I bed it's nothing remarkable. My guess it's a speed close to a scuba diver wearing closed heel long fins.
Oh and that shot with the diver wearing a loosely fitting camo dry suit, hilarious, having all that money spend on researching foils, drag and efficiency and then forget the most blatant drag inducing gear.
Maybe your character is not suited to work with this kind of folk?
I've actually written several proposals to DARPA. So far, they have all been a big waste of time. I've tried going straight to the US Navy as well. That, also, has been a waste of time. If you are not working for some favored crony of the government, it does not matter what you can do. I tend to think the criteria for getting a contract has much more to do with making sure the money is getting funneled into the "right hands", than anything else.
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Sometimes we need to look at the bigger picture... I think your fins Ron are fare superior, and I understand that the design is a result of taking many different factors under inspection and consideration.
The funny/sad thing about a project like the one in the video is that with such a great funding, they don't need to look at the bigger picture as often, and they seem to have gotten tunnel vision regarding the "propulsion efficiency" to an extend where the end product loks like a joke, or at least not very practical... I'd love to see 7 navy-seals in a helicopter wearing 7 of those wide things before making the jump... :-O
In itself though, as a way of exploring stuff and driving fin innovation forward, almost proving a principle it's interesting... In a "this-is-great-cutting-edge-military-stuff-video" it looks silly. Man that wing is HUUUGE...
Still - I like the Nutty-proffesor-apparatus somehow he he
Ron if they bought 100 your fins for about 500-1000 USD a piece, they would loose the allmost 3 Million dollars on next years innovation budget...'
The funny/sad thing about a project like the one in the video is that with such a great funding, they don't need to look at the bigger picture as often, and they seem to have gotten tunnel vision regarding the "propulsion efficiency" to an extend where the end product loks like a joke, or at least not very practical... I'd love to see 7 navy-seals in a helicopter wearing 7 of those wide things before making the jump... :-O
In itself though, as a way of exploring stuff and driving fin innovation forward, almost proving a principle it's interesting... In a "this-is-great-cutting-edge-military-stuff-video" it looks silly. Man that wing is HUUUGE...
Still - I like the Nutty-proffesor-apparatus somehow he he
Ron if they bought 100 your fins for about 500-1000 USD a piece, they would loose the allmost 3 Million dollars on next years innovation budget...
'
If we were to assume the defense department bought some version of a DOL-Fin at $1000 per unit, they would have to order 2830 units to spend the amount of money they dumped into the initial PowerSwim contract (which probably only produced a couple functioning units). I have no clue as to how much more they may have spent on follow-on contracts since then. But, these kind of manufacturing numbers would easily support new processes in high volume production techniques that would be game changing. This is why I invested so much time into proposals. Too bad I don't have any friends in high places.
FYI: From a quick Google search, 2830 is enough units to supply every single Navy Seal with their own private DOL-Fin and still have over 300 units in reserve for replacing lost, broken, or damaged equipment.
FYI: From a quick Google search, 2830 is enough units to supply every single Navy Seal with their own private DOL-Fin and still have over 300 units in reserve for replacing lost, broken, or damaged equipment.
Ron,
I think you are approaching this all wrong.
Attach a Dol-Fin to a small waterproof and remote controlled motor...
NOW, you can sell them for $285,000 a piece as Aquatic Drone technology.
Just remember... If they bite on the idea... Dial me in!
I think you are approaching this all wrong.
Attach a Dol-Fin to a small waterproof and remote controlled motor...
NOW, you can sell them for $285,000 a piece as Aquatic Drone technology.
Just remember... If they bite on the idea... Dial me in!
The Navy Seals invited me to a propulsion demo a few years ago. There were about 6 companies there doing demonstrations for various over-the-horizon Seal delivery systems. The devices ranged from two man wetsubs to the lunocet. The demo took place in a harbor on the base with all the equipment in the water at the same time. There were about 60 Seals there. One of the systems was Jetboots - an electric thruster attached to the calves - the Seals were testing these when I arrived and were quite excited about them. I began my demo of the lunocet by describing the function of the then high aspect ratio carbon fiber foils with relatively large surface area (these lunos were built for sprinting) and describing the optimal technique as best I could. The Seals had moderate results with the luno because they were not used to the swimming style. However, one Seal invited me in to give a personal demonstration. I took off from shore and surface about 50 meters out in a few seconds - they were impressed and three Seals on Jetboots nearby challenged me to a race to the shore. They said the Jetboots could do 6mph - the four of us took off. I could hear the whine of the motors fade as I rocketed toward the shore. I was already starting to take the Lunocet off when the Seals surfaced - The commander who invited me down walked up to me and said "I'll take two"
They loved them - problem wasn't ultimately in performance though but in the practicality of usage - the Seals need to be in their boots at all times so they opted for solutions that allowed for that.
They loved them - problem wasn't ultimately in performance though but in the practicality of usage - the Seals need to be in their boots at all times so they opted for solutions that allowed for that.
How did you get invited? Did they contact you, or did you go through channels to contact them? When I tried to work with the Navy directly, this is what my experience was like:
Contact my Congressman to get assistance finding out how, and who, to communicate with, to attempt to market the DOL-Fin technology to the Navy. After about 5 weeks, they give me an email contact. Send message to that person, get a robo response that says wait for another response. A couple weeks later, I get a message that redirects me to contact two other people. I send them messages. One never responds, the other does after another week, who directs me to contact someone else. When I finally get ahold of that person, they direct me to register my information on a government website and they provide a link. The website requires all the information in a different format than I had been using to communicate with everyone else, so I take another day to redo everything into the new formats. Then I find that the website crashes when I try to put anything into it. Try new formats, shrinking the size of video files, still won't work. Contact them again for help. Several more wasted days trying to work around the website problems and get the information submitted, that eventually ends up going in to their system through two different channels, so there is doubt if the people I sent the product information to, actually mated it up to the business information that was sent through the website. Three months later I get a letter that basically says; thank you for your interest in working with the ONR, don't call us, we'll call you if we want to....
It was a long painful experience with no upside.
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They sought me out. Your best bet is to find the Seals at DEMA ... I think you would have a shot at interest from them with your newest version.
Just for interest sake ,as mit was brought up it reminded me that they did something very similar to the dolfin. Type in leviathan monofin in to youtubes search engine, and you'll see a carbon fibre fin connected to a ridged member that's angle is controlled by a torsion spring connected to bike shoes, more than one way to skin a cat.
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