Footwear Designer - student project

Hi Matt

How is progress?

That is one great assignment you set for yourself there, and dare I say, a difficult one too, but I guess you already realized that by now
First of all, have you had any experience using a mono before? If not, I hope you have a freediving club nearby, where you can try and go do some research on yourself.
I think, you might benefit, as in any study project or other project with a limited timeframe, from setting up a fairly strict set of bounds; aspects you are not going to study or try to rethink in your assignment, but just take for granted. Fore instance hydrodynamics in relation to the fin blade and subsequently blade (re)design, would most likely end up being just a play around with shapes, unless you have some extraordinary programming skills and really heavy computers at your dispose.
But in relation to the footpocket design, there is a lot of need for designing; both in relation to comfort, fit, flexibility (multiple uses), weight, buoyancy adjustment, durability, recycle ability and of course sexyness. And determining from what you show, it seems like "the foot ware part" might also be what interests you
So as you know, there is basically two proven concepts by now: The hyper style fin and the mono foil.
Why not explore the later? Might wanna try to contact REVAN (aka Ron) here on the forum, and please try to read this, if you haven't already.
Hope to see your progress in text, drawing, picts and animation



Best regards
H!

this is a hard task, but a challenging one!!!
my advice is that even the footpochet will go above the ankle [in some sort of neoprene socks], i think that it must be verry flexible
you must bare in mind that in most of the cases, te bifins and the monofins are wear with neoprene socks [both for thermal insulation and/or preventing the legs to be wounded]
so if you do the fins with a footpocket like a sock, you must insulate all the footpocket in a specific way
but again...the neoprene is not so good at stretching...what abouit this?
it will be more difficult to fit into one [the mono is more difficult to be put on you legs than the bifins because you cannot do the "4" trick with the leg ]
i think that you will not be able to answer at some of yourown questions unless you actually go in the water with bi-fins or monofins
there are to many variables...
for instance: each diver has his own method of diving
and the most of the free-divers are recreational freediviers and go down not necesarelly for competitions, but for sea-sighting or underwater hunting
now...competitive freediving, sea-sighting and underwater hunting use all of them bifins or/and monofins, but they are three very different sisters of the same mother...
the stiffnes of the blades depends very much from diver to diver; me, for example I prefer the heavy and stiff ones because i have strong legs...
some prefer carbon made because is light and powerful in the same time, but can be broken verry verry easely!
you have some studies to do!
and your goal must be to come with some finns ideas that nobody has done before
to be something new, but estethic and versatile...
trust me...I'm an architect and i know this kind of struggle
btw...i like your drawings [the classic ones]

and don't forget our friends ... the marsouins!!! they deserve most of the credit

That's a hole lot of questions, maybe that's why not many people have replied.

Since I really like the idea of a monofin made for freediving specifically, and since hyperfins a made for finswimming really, I'd like to repond. I'm no expert, but the fin construction has been on my mind before: http://forums.deeperblue.com/freediving-science/94309-hydrodynamics-monofin-legkick.html

I'll answer some of the questions. I'm mostly thinking efficiancy in dynamic (pool) performance, and mostly monofin (I'm not sure if that's youre goal, or if it's bifins/stereofins, or both).:

MWalters03 said:

Hello all!


- - - - -

2. When diving downwards towards the sea floor vs. when ascending back to the surface, what are the main similarities/differences in how you use your fins?

- - - - - When going down, I only kick 7-8-9 times... after that (around 15-25m) I freefall, because the lung is now compressed to1/3 of surface volume (20m), and therefore I sink. I bend my knees a bit, to keep the fin streamlined... Going up I have to fight perhaps 3kg or more depending on a) depth, and b) suit-thickness/added weight. Worst case scenario would be something like 8mm suit, 8kg weightbelt at say 50m... That might give me 7-9 kg of weight to fight. However, this is in my opinion the the focus area for a new fin. It would rather be perfromance in the lighter end of the spectrum, fx 3 kg (competition/top performance, thin suit, glideskin=more speed).

3. Does your fin come into use more when kicking towards your stomach, or when kicking towards your back? Similarities? Differences?

- - - - - Normally downkick (towards stomach). But when heavy I fell the upkick (back) proportionally more, and use it more.

4. Would you rather have a heavier fin with more power potential, or a lighter fin thats easier to kick (during competition)?

- - - - - Lighter. But the fin should be close to neutral in weight... The "power"-fin is, to my knowledge, what we have in the old hyperfin allready: Good for sprint, but not as efficiant as it could be.

5. Are there any parts of the foot/leg that must be secured or must be able to flex?

- - - - - This is not a simple question. But many people like the feedback/feel of the fin I think, when they use the foot to move the fin. But I guess theoretically it could be straight from calves and down... Not sure...

6. Do you need to have a harder rubber/surface for the sole of your foot?

- - - - - I haven't tried without that (I'm using dol-fin x-20, and before that a monofin with stereo-fin footpockets). But I've heard, that many people using hyperfins like the small movement of the foot-tip...

Click to expand...

MWalters03 said:

1. I see many complaints on free diving message boards or in different reviews about foot pockets not fitting appropriately – certain footpockets are too narrow, too wide, etc..
What if there was a footpocket that acted like a sock. Socks are amazing because no matter how high your arch is, or how wide your foot is, the sock will fit around it nice and snug.

More specifically, what if the footpocket was more like a compression sock. Now it is really tight and secure, yet extremely flexible, and it also aids in blood circulation, a problem many divers have when going to extreme depths.

- - - Sure... sounds nice... but how is that possible? One thing is important: Power transfer...

2. Why does every footpocket collar stop just under your ankle. What if the footpocket was raised up, just below your calf, much like a compression sock? Would you in theory be able to be more secure, thus allowing more energy to be transferred?

- - - Again not sure... Might work.



- Matt

Click to expand...

Another way to go about this, is to just ask openly: What would people like from a new (next generation) monofin fx.

To me: Something that's more efficiant in pool dynamics. Something that's comfortable. It should preferably be adjustable with quick-screws... lenght/lever and blade angle, and/or resistance to bending (hardness of fin).

I have in my mind an idea of a fin that is inbetween the hyper-fin and the dol-fin. A rigid blade/fin/foil, at the end of something looking like the hyperfin footpocket, but with spinning shoe-like adjustment, just more hydrodynamic. Like if you cut the hyper-fin footpocket in two, so it could open close... The moving/flexible part would be a short hydrodynamic adjustable piece between footpockets and fin/foil/blade. It should be wider than a hyperfin. Slower but more efficient. But this is a HUGE challenge I think, took Ron 25 years I think... (allthough it could be the start of a new design!...).

Something like the Tsuji: Dolphin shaped monofin on this page APNEA.cz - Collection of Weird Fins, but wider and with flexible a part in the middle (between foil and footpocket). One problem (that Roneliminated) might be too big dead space when changing direction (upstroke to downstroke), so the fin would have to be a lot like the dol-fin also. By the way, take a look at this beauty: http://forums.deeperblue.com/monofins/85969-extreme-dolfinism-39.html#post894107

Oh, just want to add: About the design without ancle flexibility. Perhaps it's not a good idea because you would have to break the streamlining more - look at this page fx:

DOL-Fin X-20: return stroke improvement! - Le blog de Universal Freedivers