new fin concept

[TN Traveler]

At this time Excellertors are not available from Force Fin. Bob has been forced to relocate his production and has not yet geared up to produce fins out of the Tan Delta Material. He just recently started to produce the Force Fin Pros (in yellow) again. It will probably take some time before he can get a group trained to work with both the old Tan Delta material and hopefully the new Tan Delta material that is used in the Hockey Fins and redesigned Foil Force Fins.

I have "dibs" on the first pair of Excellerators made out of the new Tan Delta material.

 

[victorzamora]

notation: I'm an Aerospace Engineer and a scuba diver. My specialty was fluid dynamics. If you're serious about this, sign me up for testing and/or analysis (preferrably both ).

I'm very skeptical of new fin designs, as most of fluid dynamics is witch-craft and magic. There are several fins that look like snakeoil to me, but I want to try them before I pass judgement. I have been DYING to try one of the Force Fins, but have not yet. I think they could be legitimately great fins with great science as a background, or they could be some of the most widely defended snakeoil-type fins around. Again, it's my experience in fluid dynamics that makes me so weary of the "specialty" fins.

So, seriously.....send me a PM if there's anything I can do to help. I'm dying to get some more REAL engineering work in front of me. I'd also LOVE to have something to test, as this would help me verify my computational claims.

 

[Just_Me]

From drawing to store shelves, this is what I do for a living. Not in the diving industry, but several others. The formula is the same across the board. Always hurdles of the old dogs, this is where it's important to know your consumer. It's even more important to know how to reach the consumer. The old dogs are beat by utilizing new means to reach the consumer. Social media is powerful enough that we are having this discussion because of a single question asked on this social media outlet. Test what exists, and be honest, will yours be more or less productive. Let me know if I can help.

 

[danvolker]

Like Just_Me said,
I think testing needs to get initiated...probably pick 2 or 3 major fin brands you want to go after for market share--beat them and take their market----maybe the Slingshots, a major Split fin brand, and maybe Jetfins......Test the flex of each fin--the torque it takes to reach maximum bend before thrust is lost, then test the hydrodynamic surface of each and how well you would predict the form of the fin will effect the flow of water over it, and the propulsion effect this will have along with the snap of the fin...the return of effort back....

Then estimate how your design will do in each of these testings--how well you would out-compete the brands you must sell against.....

If you can really beat them badly, the next step will be getting credibility for your tests...and after that, guaging interest in the results...if you really beat the others badly, you should get funding....

Whatever you do, please create a test that will show how pathetic Split fins are !!!

 

[GrumpyOldGuy]

You are going the have to pry the jet fins from their cold, dead feet of their devotees. Logic will not prevail.

The divers using sling shots and split fins will be more willing to try something different. I would really look at the geezer divers, they have money to by premium products and are old enough to have physical limitation and that makes alternatives interesting. Similar issue for traveling divers who need something really light and compact and might be willing to accept some tradeoffs

 

[notation]

Dear Notation. The good advice from those on Scubaboard and my self would be to make sure all who you show your idea, sign non-disclosure agreements first, then file those patent applications and seek investors. Sure I like to support new ideas...but new ideas and dreams come to all of us. I always tell Susanne, my wife and life partner, ideas are like seeds to the mind and those who learn how to plow the field with their sweat and hard work see the rewards. Please, remember you are taking on an adventure, and no one who is willing to risk is a novice. Go forward and make the change to the world that your destiny drives. Best, Bob

Hi Bob, I went to one of those buffet places today and guess what I got in the fortune cookie?

"Prosperity belongs to those who can learn new things the fastest"

I've got a list of things to do right away and great people on the SB I'd like to contact. There's a lot to learn about fins. That's for sure. Thanks for the inspiration and hope you like the Turbo Fin!

victorzamora, aerospace engineer, scuba diver + fluid dynamics specialist? Wow! I'm checking the drawing again and the design isn't like any other fin. I've increased surface area (potential water that can be pushed around) without adding length or width. Positive thrust is achieved with any kick. The natural design works equally with every motion cycle (2x) and there's no attachments, expansions or bumpy's. I'm in the Boston area.

Just_Me, you are on the list. Let me get the non-disclosure agreement drafted. I did some textiles patent work in the 80's and within one year a German company had nearly duplicated the technology. I do understand that part of the business.

danvolker, solidworks has a computational fluid dynamics (CFD) tool... although I don't know how to use it yet. If that works out, the design (torque and thrust) will be fine-tuned and onward to the water tests. What's the name of your boat? "You're going to like those fins."

 

[Just_Me]

Keep me posted.

 

[victorzamora]

notation, if you're near Boston then I have to ask if you like to pahk yah cah in hahvahd yahd

Jokes aside, though, Solidworks does an alright job with its CFD tools, but it's much more useful as a flow visualization tool than an actual data analsysis tool. Unfortunately, the good CFD tools pretty much require an Aerospace Degree to get working right.....because you have to have a working knowledge of the fluid dynamic principles, equation, and derivations thereof to properly set up the programs. Also, depending on your design, you may have to create SEVERAL models to simulate your whole workflow and do a superposition of results to get anything useful. The amount of give in the material, both in the "blade" and in the foot pocket are VERY hard to account for....plus any give in the booty worn with the fin. Fins become a "flapping wing" model with unconstant theta-dots. Worse than that, they rotate and translate in all three directions simultaneously. I guess you could keep your CFD analysis to a flutter-kick-style analysis and then once you've got that right, physically test for helicopter turn and frog kick. I alluded to this earlier but didn't state it directly: hydroelastic effects are going to be CRUCIAL, but they're going to be the hardest to generate computationally.

 

[danvolker]

Hi Bob, I went to one of those buffet places today and guess what I got in the fortune cookie?

"Prosperity belongs to those who can learn new things the fastest"

I've got a list of things to do right away and great people on the SB I'd like to contact. There's a lot to learn about fins. That's for sure. Thanks for the inspiration and hope you like the Turbo Fin!

victorzamora, aerospace engineer, scuba diver + fluid dynamics specialist? Wow! I'm checking the drawing again and the design isn't like any other fin. I've increased surface area (potential water that can be pushed around) without adding length or width. Positive thrust is achieved with any kick. The natural design works equally with every motion cycle (2x) and there's no attachments, expansions or bumpy's. I'm in the Boston area.

Just_Me, you are on the list. Let me get the non-disclosure agreement drafted. I did some textiles patent work in the 80's and within one year a German company had nearly duplicated the technology. I do understand that part of the business.

danvolker, solidworks has a computational fluid dynamics (CFD) tool... although I don't know how to use it yet. If that works out, the design (torque and thrust) will be fine-tuned and onward to the water tests. What's the name of your boat? "You're going to like those fins."

Hi, no boat, but I do have a Facebook Page and website for all the boats and the best Hotels for Divers in Palm Beach county.....see www.facebook.com/WILD.DIVING I look forward to trying the fins!!!....
This might be a good place to tell the story of how I met Bob Evans....I think you will appreciate this

Back in the mid 90's, I was very into spearfishing and high speed cruise paced diving....and had found how much more efficient Freediving fins were than traditional scuba fins....in those days I was using Esclapez fins.
I am not sure what got me started on it, but one of the local shops pulled my chain about fins, and were pushing the classic Force fins at me.....the thing is, unlike 99% of the fin manufacturers, Bob actually made fins for different fitness levels of divers , and for different pace type needs....and of course, the shop did not specify any of this--they just pushed what they had.....That, plus Bob had some aggressive ads in those days, and I went on a mission to set every one straight...on Rec.scuba, I began the Force Fin Challenge.....I made an offer that if ANYONE came to Palm Beach using force fins, and was able to just keep Jimmy Abernethy and me in sight, on our normal cruising pace for a spearfishing dive, we would give them a free Stay at a dive hotel, and free boat trip for a weekend. I knew all the hotels and boats in those days too

This thread got some huge traction on rec.scuba, and I became a significant pain in the neck for Bob. Thousands of divers interacted in this thread, and while it was making a point that this design was not as fast as freediving fins.....it neglected to deal with the issue that many people really don't want to exert or to go anything but slow.....and moreover, the real issue with the Classic force fin, was that it was a small gear on purpose, and Bob had many other versions of the fin, for more athletic divers, and for more aggressive propulsion--some outright amazing on what they could do.....but I did not know that at the time.

So along comes the DEMA Show , I am there because of Diving Palm Beach | Diving West Palm Beach | Palm Beach County , and I had been enjoying trashing the h*ll out of Force Fins and making it a famous challenge on rec. scuba....and as I am walking around the DEMA show, this guy jumps up and puts his arm around me, and his friends take photos of the two of us as if we are buddies! And this guy turns out to be Bob Evans, and he thought it would be really funny to post shots of him and me as friends, with all the trashing I had been doing...

In fact, he was such a character, I had to chat with him for a long time, and ended up trying many of his other fins, the ones made more for people with my interests --and I was blown away....and, ultimately, I felt compelled to explain the issues with the Classic Force fin versus the Freedive fin, and that Force fin had some super power fins for those who wanted them....and in fact, freedive fins typically come in very soft flex for 8 hour spearfishing competitions, in medium stiff for more normal use, and stiff for deep drops to over 100 feet deep on a breath--usually for less than an hour of diving.....so the concept of owning several fins and picking the right one for the job, was not new.

Today, Bob is a good friend of mine, and still one of the most unique characters in the dive Industry

 

[notation]

notation, if you're near Boston then I have to ask if you like to pahk yah cah in hahvahd yahd

Some do, some don't... actually, it's starting to get busy in that paht of town.

I've got an idea for the first model and will layer pre-cut fiberglass on wire mesh towards the final shape for a prototype mold. In the short-term, I'm working on the non-disclosure agreement. Discussing the project online has really helped, but as Mr. Evans mentioned, there are no short cuts.

danvolker, many thanks for your expert opinions and feedback. Reading the reponses sort of answered the original question re the value of a better or new fin. Every fin has different performance parameters, kind of like a surfboard. So, when designing a new fin this will have to be considered and more than one version tested.

Palm Beach next stop.