Author Topic: What do people want in a foil?  (Read 7526 times)

Phils

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Re: What do people want in a foil?
« Reply #15 on: June 20, 2020, 05:19:06 PM »
In spite of the video showing guys doing it, I still don't see the point of trying to go super fast down wind with a wing.  Wing down winders where you can carve and ride swell and not work to get back upwind is great but if you wanted to AND had the conditions to wing down wind fast, a paddle would be much less cumbersome than a wing.  I don't see a market for fast wing foils.  There are much better ways to go fast with a foil than using a wing.

flkiter

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Re: What do people want in a foil?
« Reply #16 on: June 20, 2020, 08:13:40 PM »
It's interesting to see what people are looking to come out. I didn't think going faster on a wing in the waves would be one of them. Looks like a few companies are going that route like Moses. I wonder if Mike's Lab will have a speed foil for winging soon. Very cool to see the foil sport break into so many disciplines. Just imagine a few years ago the options were so limited and now it's a plethora of options. Wonder when it'll level out like kite foils did.

Admin

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Re: What do people want in a foil?
« Reply #17 on: June 21, 2020, 01:38:37 AM »
This image still captures the ideal of swell riding for me.  Plenty of speed to gouge but still sticking with a swell.



Phils

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Re: What do people want in a foil?
« Reply #18 on: June 21, 2020, 02:36:48 AM »
Many want the glide found in high aspect wings with the turning speed and roll agility of a lower aspect wing.....there is a way to get both in one foil and that is with a monofoil.  You give up a lot of pitch stability but the reduction in drag is astounding if you cut off the fuse beyond the front wing.  I have a Delta monofoil I use for kiting and it takes a few sessions to get used to but your body learns to manage the pitch instability pretty quickly.  The wing is 1500 cm2 with low a AR but the glide is amazing (it makes even small kite foils feel draggy) and it turns on a dime.  Even if a monofoil concept is too radical for most, I think there is a lot of unexplored potential in minimizing the stabilizer/fuselage to achieve better glide without giving up turning speed.

Solent Foiler

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Re: What do people want in a foil?
« Reply #19 on: June 21, 2020, 11:49:51 AM »
...

This is also probably very sport specific.  When you think of surf foiling vs Wing foiling for instance in terms of the forces being applied (or not) in this video it is clear how different the needs are:

https://www.youtube.com/watch?v=q1abYwkEscE

Well, I learnt something from that vid and actually applied it today. Previously, I was finding that my ride height was dropping quite markedly each time I was being hit by a gust and accelerating hard in the harness. Put a bit more stab angle on and that went away, but had another issue! I was leaning the board so far over to windward when going upwind that the tip of the foil was breaking the surface in some of the chop troughs, ventilating, stalling and crashing. This is on an 85 cm mast and Naish Thrust L, which has quite downturned tips, 4m Pulse in 20-25 knots average, but very gusty.

Don't know whether I can change anything apart from technique to resolve that one or even if a different foil design would make a difference. Do have a 100cm mast coming soon which should help.

Coming back downwind was a total hoot. The foil is so loose and maneuverable, with a low stall speed which was really fun, as I was riding gusts on flat water, rather than waves, some forgiveness on the stall speed meant I could leave it late to power back up again.

I'm not sure where that puts me, thinking about this thread. What do I want from a foil? Given I'm only riding this one due to unforeseen circumstances, I'm now pretty pleased with how it's running for my upwind downwind loops, in most areas apart from one - swapping feet after gybes is hard - very twitchy. Nothing better technique won't solve, but a bit frustrating. It's quick enough, seems to go upwind nicely locked in on it's side with its flat downturned tips, really engaging (not a cruiser!), and super fun downwind.

Perhaps someone with more experience could pick holes in it, but the issues I have with it I just see technique hurdles to be overcome. My new foil is coming with the new mast, and I genuinely don't know which I'd have preferred today. I've ridden it once and loved it (not in conditions like today) but maybe the slightly tricky but sooo fun Thrust L might have overcome the smooth ease of the Gong Curve/Pro L. Time will tell, but I think I'll have a soft spot for the Thrust whatever...

I'm 5'10", 66kg riding:
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Axis ART 799, 899, 1099, HPS 880 US & CS Adv fuse, 85cm mast
Gong Fluid L-S, XXL-S on 85cm and 65cm mast
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supfoo

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Re: What do people want in a foil?
« Reply #20 on: June 21, 2020, 05:54:01 PM »
Wings........ that are affordable. :-[

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Re: What do people want in a foil?
« Reply #21 on: June 22, 2020, 10:21:41 AM »
Many want the glide found in high aspect wings with the turning speed and roll agility of a lower aspect wing.....there is a way to get both in one foil and that is with a monofoil.  You give up a lot of pitch stability but the reduction in drag is astounding if you cut off the fuse beyond the front wing.  I have a Delta monofoil I use for kiting and it takes a few sessions to get used to but your body learns to manage the pitch instability pretty quickly.  The wing is 1500 cm2 with low a AR but the glide is amazing (it makes even small kite foils feel draggy) and it turns on a dime.  Even if a monofoil concept is too radical for most, I think there is a lot of unexplored potential in minimizing the stabilizer/fuselage to achieve better glide without giving up turning speed.

I dont want to be giving away any secrets but stay tuned 😉😉

SUPeter

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Re: What do people want in a foil?
« Reply #22 on: June 25, 2020, 04:41:00 AM »
The beauty of high and ultra high aspect wings with appropriate washout is that you only need to activate the most central portions of the wing during times of excessive speed.  Once you slow down, adding a little more Angle of attack allows the outer portions of the wing to engage.  This has already been accomplished by many makers and manufactures.  Hitting upon that real magic combination is only a matter of continued experimentation.  We will get there sooner or later.

jondrums

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Re: What do people want in a foil?
« Reply #23 on: June 25, 2020, 01:40:01 PM »
washout is a twist in the angle of attack down the length of the wing?  Are you saying that the outer sections would have less angle of attack than the middle section?

PonoBill

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Re: What do people want in a foil?
« Reply #24 on: June 25, 2020, 08:33:36 PM »
The beauty of high and ultra high aspect wings with appropriate washout is that you only need to activate the most central portions of the wing during times of excessive speed.  Once you slow down, adding a little more Angle of attack allows the outer portions of the wing to engage.  This has already been accomplished by many makers and manufactures.  Hitting upon that real magic combination is only a matter of continued experimentation.  We will get there sooner or later.

That's what I used to do with slope glider designs to get speed and still have enough lift to recover in looping maneuvers. Push the nose down and the only lift is at the wingtips. At the end of a long, accelerating dive you lift the nose a tiny fraction and the glider climbs like it has JATO boosters. Lift the nose a little too much and you leave the wings behind.
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

SUPeter

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Re: What do people want in a foil?
« Reply #25 on: June 26, 2020, 04:20:37 AM »
In answer to Jondrums question, Yes.  Relative to the angle of attack of the wings center ( which is usually set at positive 2-3 degrees relative to the fuselage), the wing tips would only be about 1.5 to 2.0 degrees positive AoA, relative to the fuselage.   To put in a more easily understood way.  I just make my wings with about 1 to 1.5 degress downward twist at the wing tips relative to the wings center.  This twist is worked in gradually over the length of the wing.  So for these very long, high aspect wings, this twist is very gradual and hence makes for a very versatile and forgiving wing.   So in essence, the center of the wing is always lifting while the wings outer ends only lift when needed. 
« Last Edit: June 26, 2020, 04:27:01 AM by SUPeter »

PonoBill

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Re: What do people want in a foil?
« Reply #26 on: June 26, 2020, 09:04:09 AM »
Thanks Peter, your response reminded me that I was talking about wash-in, not wash-out. Most wing designers consider wash-in to be absolutely evil, but it's useful in an esoteric version of RC slope gliding.
Foote 10'4X34", SIC 17.5 V1 hollow and an EPS one in Hood River. Foote 9'0" x 31", L41 8'8", 18' Speedboard, etc. etc.

jondrums

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Re: What do people want in a foil?
« Reply #27 on: June 26, 2020, 12:47:44 PM »
that is so sweet SUPeter.  I love the concept.  Are any of the high aspect wings incorporating this design feature today that we know of?

Beasho

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Re: What do people want in a foil?
« Reply #28 on: June 26, 2020, 02:35:40 PM »
I think some are missing the simple fact that you are going to over-foil and crash a lot doing “winging” downwinders (when the swell is good) until we get foils that CAN go faster, while still having the glide to SURF.

Just as tow-in guys have already seen it. Tow in guys have been forced to use kite foils. Wingers are starting to use kite foils. The manufacturers need to react and produce wings to meet this challenge.

Guys are already seeing this, in little ole Cocoa Beach on 6 ft days.

It’s not about racing, nobody is racing. I’m measuring speed to find those wings.

It will help as people start providing OBJECTIVE speeds to these assessments.  When my TRACE was working I could strip out data points on individual Wave Rides.  This means recording speed every 1/5 of a second.   Graphs looked like this for the old school GoFoil KAI vs. Maliko 200 vs. IWA.

My newer GL 210 has the same speed profile as the IWA but much better glide.  The GL 140 handles much higher speeds on a regular basis meaning 20 to 22 mph.  Up to 24 or even 26 mph without massively loading up and throwing me.

The Std Deviation -1 to +1 shows a pretty believable range of "Comfort" flying the wing.  Within +/- 1 Std Deviation the wing was comfortably flying vs sinking or needing to load up front foot pressure to keep from breaching.
« Last Edit: June 26, 2020, 02:38:48 PM by Beasho »

SUPeter

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Re: What do people want in a foil?
« Reply #29 on: June 30, 2020, 06:49:23 AM »
I believe a wing can be designed to never load up too much regardless of speed.  On some of my newer prototypes. I have been unable to find the high end max speeds.  Time to get a bigger outboard motor I guess.  Using ultra high aspect wings and appropriate washout is my answer to this problem.  Others may find better answers, such as using aerodynamic twist versus geometric twist.   My goal of creating a surfable wing to be used in wing foiling is attainable.  Of course, every design feature leads to compromises elsewhere. 

 


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