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Extreme Dolfinism G2

Discussion in 'Monofins' started by REVAN, Apr 30, 2014.

  1. HydroApprentice

    HydroApprentice Active Member

    Local Time:
    11:39 AM
    I love the efficient design! If the tech works, I'd rather have that strapped to my feet than something which is designed to be esthetically pleasing. I always found that efficiency has its own kind of beauty, and without having ever tried the Lunocet or the Dol-Fin, I find the latter more appealing
     
    REVAN likes this.
  2. lil jon

    lil jon Active Member

    Local Time:
    7:39 PM
    I'm assuming the x20 and the lunocet? In terms of where it matters, the x20 outperforms the lunocet by a long shot. I'm talking 50% better. Here's something that compares similar to the performance of the Lunocet (classic) at a faction of the price.

    [​IMG]

    Yes I have those fins in the picture and yes they are similar in terms of effort required, number of undulations, speed and distance covered.

    just eyeballing it, I think the lunocet has similar if not slightly less surface area than the x-20. By "slightly", I'm guessing about the size of your palm. I think the only unhappy customers about the Lunocet are the ones who value factors other than aesthetics.

    The lack of performance is appalling after the big talk and reviews.
    From the Lunocet (classic) site
    It can take you great distances underwater with little exertion
    The lunocet was born of a need for speed… underwater speed

    The result?… The most efficient swim fin ever developed.
    (all big talk with absolutely zero data to back all these claims up)

    In hindsight, the few people who talk the Lunocet up are essentially people who have been bought over with free gear. They ignore negative comments, talk up irrelevant information that may seem to make the Lunocet really good and scoff at request for any performance data.

    Delivery dates, post customer support, how he received feedback, lack of instructions, quality of materials, precision of manufacturing. performance.
    Yes I could say I'm very unhappy with it.
    I was once typing out a thread on why I wouldn't buy the Lunocet but I stopped halfway. Didn't like the negative energy I was feeling and I generally don't like to talk bad about people. I have since already taken a "I give up" approach despite being an active early contributor to the Lunocet thread.

    I know of other customers (3) who are unhappy. They just can't be bothered to come to the forums and type about it.

    Would you buy a brand new sexy looking car that required (amateur) fixing after you bought it? Then why would you buy a Lunocet?
     
    noa and Kars like this.
  3. cdavis

    cdavis Supporter Supporter

    Local Time:
    10:39 AM
    I think Ichthys is on to something on the "aesthetics" area. I look at the lunacet experience and can't find any other explanation. The
    Lunacet looks great, much cooler than the Dol-Fin. Ted has done some outstanding marketing that capitalizes on that fact. But when you look at history and results, I can't see anything to recommend a Lunacet. My(and this goes for most divers I know) gear must (1) come from a reliable supplier with good customer service, (2) be extremely durable, (3) work really well. Ted's customer service is so bad (and has been so for so long) that I wouldn't buy anything from him, no matter how good. The fin, in its "whale tail" versions has had a large number of mechanical failures, wear problems, etc. In most of the cases I've looked closely at, its easy to see good engineering reasons for those failures. Durable they are not. In performance, the Lunacet appears to be getting better, but doesn't seem to live up to the hype. The classic, not withstanding some great marketing, is clearly not a good fin for most free diving, comments from users strongly suggest this and Apneaaddicts review confirms it. The Pro or the newest model, I haven't seen a decent review or comparison to a hyperfin or Dol-Fin, so can't say, but why, given history, would anybody get excited about these models until they are thoroughly tested? Ted's performance in any one of these three areas should be enough to make divers run for the hills, much less all three, but it doesn't seem to be happening. This seems especially strange to me since the logical comparison, the D0l-fin, has a manufacturer with outstanding customer service , is flat out bullet proof, and has hyperfin performance.

    Ichthys is right that there have been no loudly dissatisfied owners on DB. Reading the various posts, I'm pretty sure I see some disappointment, but nobody is really bitching. So, why??? All I can figure is that the thing looks so good it wins people over. Great marketing helps that.

    Disclaimer: I am aesthetically challenged, just don't much care what it looks like as long as it works well. Makes it a little hard to judge this one.
     
    REVAN, noa and Kars like this.
  4. cdavis

    cdavis Supporter Supporter

    Local Time:
    10:39 AM
    Well, I guess there is at least one loudly unhappy owner. Might be instructive to poll some others.

    Thanks for your comments, LilJohn
     
  5. Fondueset

    Fondueset Carp Whisperer

    Local Time:
    5:39 AM
    I've not yet been able to do a hard-core comparison of the Dol-fin Orca Gen2 with my exquisite Starfins Hyperfin - which is now almost an extension of my nervous system - But I can say it is very, very close - and may exceed it in dynamic. The Gen 1 was reasonably close but not quite - the Gen2 - in addition to improved leverage (not that the Gen1 is bad) has a wider blade and really does go quite well.

    I did a number of distance swims with the x22 (x-20 with float) and found it quite impressive. In the pool the Orcas (both models and blade sizes) are notably better.

    None of these fins, in my thoroughly peculiar opinion, blend aesthetically anywhere near as well with the human form as a hyperfin - though the Dol-fins do have that 'poetry of mathematics' look that some of us are drawn to :)

    I've considered getting a 2015 lunocet - but I cannot spring for gear just to review it at this time - so I cannot comment on it.

    They are two 'mechanical fins' so comparison is inevitable - but they run at different price-points and I think, in practical terms, have different priorities and are aimed at slightly different markets.
     
  6. REVAN

    REVAN The Right Stuff Supporter

    Local Time:
    2:39 AM
    The Orca is aimed at the competitive freediving market, but it is also a very capable recreational monofin. The Lunocet Pro claims to be aimed at the competitive freediver market, but it has not been able to effectively reach it due to substandard performance. You are correct though that the Lunocet and the Orca2 are at very different price points, and therefore, would not share the same customer base.

    The X-20 reaches into the price range of the 2015 Lunocet. However, I consider the X-20 to be a recreational monofin even though it doesn't lag hyperfin performance by much. Functionally, it is intended to do what something like a Special fins flyer style monofin does, but a little better and with numerous advantages of utility and longevity.

    This is an exciting time to be a freediver. There is a lot of activity and progress in equipment development and in training techniques that are allowing divers to do far more than was thought possible 10 to 15 years ago. I think most divers are looking for more everything from their gear. They want equipment that is comfortable to use in both warm and cold water, that travels better and lasts longer, but I don't think they are willing to give up any performance to get it. Price can be flexible, but it depends on the performance and the advantages the gear can provide.

    It used to be that people would only pay about $200 to $300 for a monofin. Then the Hyperfins came out, set records and demonstrated that they worked better. Now, people are willing to pay anywhere from $500 to $1000 for a hyperfin style monofin. I'm hoping that the Orca2 will have enough advantages over the hyperfins to be worth it to people. If it is accepted by divers, the next step will have to be taking another look at the X-20 concept and decide how that product should evolve to better meet customer's needs. In the mean time, I have marked them down in price to make them a more attractive purchase.
     
    Last edited: Sep 3, 2014
  7. REVAN

    REVAN The Right Stuff Supporter

    Local Time:
    2:39 AM
    Freedivers, in general, are a very polite and helpful group of people. You just cannot be effective and excel at this sport if you are an angry hothead. The quiescent behavior that divers project during a statics competition, I think, often seems to engage them when participating on these forums. They usually don't make loud public outbursts. You need to take that into account, and sometimes a little interpretation is necessary.

    Also, I think some people just simply liked its aesthetics, and wanted it to work so badly that they were in denial and deliberately overlooked the information posted that showed there were problems. At one point, I did a recap on the Lunocet thread of what was actually known, attempting to separate the evidence from the hype. It didn't go over well, because some people just did not want to see any facts that conflicted with their desires. Like lilJon, I too eventually gave up and quit following the Lunocet thread, and I'm sure that my comments have long since been lost in the bulk.

    On that, I'll close with a little joke: If someone insists on diving in d'Nile, they are likely to get bitten by a crocodile. :)
     
    Last edited: Sep 3, 2014
    Kars and noa like this.
  8. noa

    noa Well-Known Member

    Local Time:
    10:39 AM
    Very well said...
     
  9. divebike

    divebike Active Member

    Local Time:
    7:39 PM
    One thing with the dolfin range of products is the belief I think of most of the commentators and my my view that it is giving up something in the blade design by not being as close to a highly evolved underwater creatures fin as it could be, not being swept back would be the obvious difference between it and said creatures, the lunocet addresses this at least, this being said the dolfins still by the sounds of the informed commentators on here appears to be the better set up currently .
     
  10. divebike

    divebike Active Member

    Local Time:
    7:39 PM
    Revan is an experienced manufacturing engineer, I just wonder if he's fully explored the different manufacturing techniques that would allow a fin closer to that of the top animal swimmers to be a viable alternative to the extruded aluminium foils that he supplies as part of his dolfins. I think it is the closeness to the ideal animal form that is talked about as the aesthetics of these fins , I don' t believe you're all wanna be art critics, it's really that it's not striving for perfection in the fin design that is being talked about as aesthetics
     
    Ichthys likes this.
  11. Fondueset

    Fondueset Carp Whisperer

    Local Time:
    5:39 AM
    I'll chime in here. One question that probably ought to be raised is the actual utility in emulating the form of fish/cetacean propulsion for humans and the difference between the FORM and the actual principals that make it effective.

    The orca is a 'high-aspect ratio' foil. The idea is to emulate the principals governing a swordfish, or Tuna's tail - both of which are optimized for endurance and are relatively high-aspect designs - though not as purely as the Orca. The key element in it's design is the relationship between thrust and drag. The Dol-fin foil has very very low drag because it is structurally very thin - and because it is no bigger than it has to be from front to back. So, while it has less surface area to generate thrust than a hyperfin - it also has much less drag. The devil is in finding the balance.

    It is a design optimized for Cruise.

    The math with a hyperfin has got to be really complicated - because of all the changing angles - but it is essentially a high-aspect foil - though, as mentioned, it flexes - complicating things.

    However the point is this - The Dol-fin is a 'form follows function' design. It makes no attempt to aesthetically emulate fish propulsion - instead it embodies the principals of such propulsion as they are understood in aero/hydrodynamics with the intention of applying them to the problem of human aquatic propulsion. While I'd love to see a nice half-moon shaped foil - because of the relative rigidity and strength of the materials being used - it my actually be less efficient. An obvious advantage of a curved or v shaped design would be fitting more surface area into less width - however the drag pretty much has to increase because of the orientation of the fin relative to the direction of travel as water moves over the blade. As an engineer Ron understands this way better than I do, but basically - with a curved design, you are presenting more surface area (front to back ) relative to the direction of travel - which means more drag.

    It's probably possible to do a curved foil design that works well - but I would think it would require some fairly precise and expensive tapering and such - depending very specifically on the performance of the materials.. In other words: Expensive.
     
    noa and Ichthys like this.
  12. REVAN

    REVAN The Right Stuff Supporter

    Local Time:
    2:39 AM
    I have a design constraint that I must work within that is not negotiable on any level. My product has to interface to the human body. Human legs and feet come in a statistical range of lengths relative to the overall body size, and have limits to the loads that can be reasonably applied to the feet. These design constraints have been optimized for walking and not for monofin swimming. As a designer, I must strike compromises in order to meet these constraints while still getting the most performance from the hardware that I can get.

    I have built and tried fins that are swept back. In my case, they did not work as well as the straight foil. If I could change some of my design constraints, that may not be the case, but for how things are working now, the straight foil works better and feels better. It is not a design choice simply made for the sake of mechanical simplicity. Although, it has that benefit as well.

    In nature, flexible deep-delta shaped fins are more prevalent than foils. However, that characteristic flip-flops if you restrict your sampling to nektons that have mass more than about 50 Kg. These larger animals that use foils have taken millions of years to evolve and adapt their bodies as well as the shape of their tail. So, just because we see a lot of swept foils on large nektons in nature, that does not necessarily mean that a swept foil is the best solution for us, with our bodies optimized for walking. Also consider that there is no sweet spot in nature for sweep angle. It runs a wide range of angles. Blue whales have one of the highest sweep angles, whereas male narwhals don't have any sweep in their tail planform. Like the DOL-Fins, the male narwhal's tail has an unswept cordline out to the raked tip. So, nature suggests that the sweep angle of the foil is negotiable, and may not actually be all that important.

    Narwhal Tail Shape:
    narwhal-narval-05.jpg
     
    Last edited: Sep 3, 2014
  13. Kars

    Kars Well-Known Member

    Local Time:
    11:39 AM
    If biological creatures could use aluminium, their designs would differ.
    Form follows function and materials.
     
  14. Ichthys

    Ichthys Well-Known Member

    Local Time:
    5:39 AM
    I disagree--I can't help but think think there are some limitations unconsciously imposed, but since you are the engineer, and your product works, I'd be kind of foolish to argue the point when I'm in over my head. :) I could go further in my opinions, and in a casual 1-on-1 conversation I might have, if the interest were there, but I think it's in very poor taste to criticize someone you don't know, in he creation of something you haven't made. Very interesting to get a glimpse at some of the thought-process which went into your creation.

    P.S. Thanks for the tube-snorkel instruction video--I'm building one now!
     
  15. Fondueset

    Fondueset Carp Whisperer

    Local Time:
    5:39 AM
    I agree Kars - what I was thinking. Fish fins flex in ways that would be very difficult to emulate.
     
  16. baiyoke

    baiyoke Well-Known Member

    Local Time:
    10:39 AM
    I own an X-20. I´ve been in a 2+ year constant mental process of modifying it for a "pure Dynamic competition individual body-adjusted fin"... And now, talking about aesthetics, when I look at a conventional monofin/hyperfin, it looks huge, clumsy and slow... to mee.

    I think a lot of this is in our head...

    This summer when in Malta on holiday, I happened to see that it was possible to dive with Tuna Fish ( http://www.snorkelingmalta.com/snorkeling/?snorkeling-info=tuna-park-snorkeling ) and I suddenly realized that it was an instant big wish, almost as big as diving with dolphins (I didn't go for many reasons and dolphins being mammals still makes it more interesting).

    My point is simply this: The First time I saw the Dol-fin Classic it looked really weird to me, like a bath wiper. Now (especially the Orca model) all I see is a beautiful Bluefin Tuna...

    [​IMG]
     
    Last edited: Sep 3, 2014
    Chipswim, Fondueset and REVAN like this.
  17. REVAN

    REVAN The Right Stuff Supporter

    Local Time:
    2:39 AM
    Personally, I believe the tuna is a far more refined swimming machine than a dolphin. Tuna have been evolving to optimize their swimming performance for a much longer time. From a fluid mechanics perspective, tuna display a number of highly advanced flow control features to optimize efficiency that dolphins lack.

    I think dolphins make up the difference by having warm blooded air breathing metabolisms that allow them to exert more power. And, dolphins definitely have more of a personality that we can identify with. But, when it comes to swimming systems, I think the tuna have more to teach us.
     
    noa and Fondueset like this.
  18. Fondueset

    Fondueset Carp Whisperer

    Local Time:
    5:39 AM
    I agree -
    Meant to say - that mod on the x22 - Revan - made it quite hotter looking. I think you should get as many of those bad boys out there as you can. Not sure what all else was different than the x20.
     
  19. Fondueset

    Fondueset Carp Whisperer

    Local Time:
    5:39 AM
    It's almost elliptical! Now theres an idea. You could call it The Spitfire.

    http://en.wikipedia.org/wiki/Elliptical_wing
     
  20. divebike

    divebike Active Member

    Local Time:
    7:39 PM
    Tunas and billfish were the creatures that I had in mind, I think their fins must be very stiff at least approaching aluminium in stiffness, from what I've seen from slow motion footage of them swimming at high speed if they weren't super stiff at the extreme speed of the side to side movement of their fins the fins would obviously be bowing a lot , but they don't.