Author Topic: Axis Foils  (Read 217004 times)

liv2surf

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Re: Axis Foils
« Reply #720 on: January 01, 2021, 09:07:27 PM »
If you like the 1010 you'll love the 1150. I have both and never use the 1010 anymore. Anything the 1010 does the 1150 does better. It even turns better. Spooky good wing.

Yeah, finding a good deal on a used 1150 locally is what got me on this slippery slope.  Its combination of low stall speed and glide is second to none, IMO.  Now I am wondering if the 1300 will be even better. :)

Yeah, I have the 1150 and love it... but having just learned that the 1300 goes on red fuse, I think that will be nice to add to my quiver to extend my wind range for light wind winging.

@flkiter or anybody, what is the surface area of the 1300?
« Last Edit: January 01, 2021, 09:13:24 PM by liv2surf »
5'6 QUATRO Wingdrifter Pro 105L
6'6" CRUZ 'CIM' Wing Foil SUP (130L)
9'6" CRUZ Surf foil SUP (152L)
Cabrinha Crosswing X2 4m, 5m, 6m
Axis 1020; Axis 1150, Axis 1000, standard, short fuse, 500, 440 stab
65cm (and 90 cm) Project Cedrus carbon mast
Chinook Thrust 92 Paddle -- fixed 78" length

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Re: Axis Foils
« Reply #721 on: January 02, 2021, 03:07:05 AM »
What is actually confusing me is which way to the angles of incidence change with shims.

Admin posted this info a while back:
Quote
The 980 front wing has an incidence of +.54 degrees.  This is notable.  That is 1/2 of a degree !
The 420 rear wing has an incidence of -1.91 degrees (on the black fuselage only).

Shimming the back of the rear tail increases the negative AOI doesn't it ? (say it goes from -1.91 to -2.91) so how does it make it more stable with bigger numbers (or perhaps it's the other way round  ;D)

Scratching my head with all the numbers  :o

Hi Sidney,

The provided shim is a down shim.  The stabilizer in its stock position (no shim) is an inverted foil which already angles downward by 1.91 degrees in relation to the fuselage (and mast plate, and your board - if it has a parallel base and deck).  I just checked the shim that I received and it is accurate.  It increases the negative incidence by exactly 1 degree.  This shim increases that downward angle.  Using the measurements on my kit (which are duplicable every time) that takes me from -1.91 to -2.91 stabilizer incidence.

I noticed the opposite of what you are noticing.  I had pulsing with the shim installed.  Removing the shim corrected that but I still have too much lift at speed.  This isn't the same pulsing, it is very smooth but it requires increasing pressure on the front foot as it accelerates to keep it down and it still feels about to blow through when it really gets moving.  I had mentioned before that I was going to try it with up shimming by a half or 1 degree (which will decrease the negative stabilizer  incidence).  Dwight mentioned that Jacky has now tried that with some success. 

These are changes to incidence not angle of attack (which is an angle relationship to oncoming flow).  It is an important distinction because in our case (once mounted) incidence for each wing is fixed, as is the difference between front foil incidence and stabilizer incidence.

It is probably best to think of it as 3 things.  Incidence measures the angles of individual elements attached to the fuselage (this is a fixed measurement).  The difference between these angles is also important (this is also fixed).  This is not incidence itself.  This is the difference between front wing incidence and stabilizer incidence.  The angle of attack is a third element and it is dynamic, not a fixed measurement.  Angle of attack changes constantly while you are riding.  Angle of attack is much more pinned when the board is on the surface then when it is in full flight, particularly when you are doing the flatter take-off that these foils desire (no, or less pumping). 


« Last Edit: January 02, 2021, 03:19:34 AM by Admin »

Dwight (DW)

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Re: Axis Foils
« Reply #722 on: January 02, 2021, 03:26:57 AM »
To remind everyone and clarify...

Hobby horsing is not doing a wheelie, then plopping back down.

Hobby horsing = when your foil is “feeling” simple wind chop wave energy at high speed. It makes the ride pulse in a hobby horsing manor because it’s telling you “No Mas” ....can’t handle going that fast in this chop. Too much drag, too much foil, for the conditions.

Need faster front wing. Need faster tail. Need less tail angle. I need to gain weight. Need something better.

Kane was asked how he was able to wing the recent huge waves in Maui with only a 76cm mast. His answer was getting his foils trimmed as close to neutral as possible. That’s where we are going.


« Last Edit: January 02, 2021, 03:32:07 AM by Dwight (DW) »

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Re: Axis Foils
« Reply #723 on: January 02, 2021, 03:49:22 AM »
The 980 is a squirrely beast to get up compared to my other axis foils 1150/1010/920

Hah!  I had this same adjustment with the 1000 and 900 when I first tried them.  I was doing my usual thing (from the earlier Axis Foils 1020, 920, 1010, etc) and they would just leap and collapse.  I thought, these foils suck!  It isn't really a skill which changes this, it is just an adjustment in expectation which soon becomes muscle memory.  They have a different take off.  It is low and flat.  Pumping works against you.  Let them run a little bit and then ease them up.  When you are figuring it out let them run flat until you have pretty good speed, then angle really slowly.  Later you will internalize the exact point when you are good to go.  Once its in there I think you will actually prefer the takeoff.  It is quick and requires very little wind or effort. 

The 980 for me is similar in takeoff technique to the 1000 or 900 but is much easier in that it is way more forgiving and doesn't collapse nearly as easily.  Once it is up it is at speed almost instantly.  This is where it excels like no other.  That is where you would still be milking the other foils to get them moving. 

It is probably also worth noting that we are all likely (and expectedly) having very different experiences on these foils.  Every 20 lbs changes things a lot.  20 lbs doesn't sound like much, but it is 12% of my body weight.  The area difference between the 980 and 930 is 8%.  The difference between the 1050 and 980 is 12%.  The differences are much less again comparing wingspan.  This is similar with any metric you want to look at.  Sure wings have a range and you can tune them, but even so it is very different experience.  We a not all going love the same foils.

There are 5 sizes of the HPS wings coming.  The 1050 and 980 are the two largest and it is safe to say that almost all riders will be covered.  These wings generate a lot of lift.  I would be surprised if they slated 5 sizes and left out a common weight class.
« Last Edit: January 02, 2021, 04:33:21 AM by Admin »

Alysum

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Re: Axis Foils
« Reply #724 on: January 02, 2021, 03:54:01 AM »
What is actually confusing me is which way to the angles of incidence change with shims.

Admin posted this info a while back:
Quote
The 980 front wing has an incidence of +.54 degrees.  This is notable.  That is 1/2 of a degree !
The 420 rear wing has an incidence of -1.91 degrees (on the black fuselage only).

Shimming the back of the rear tail increases the negative AOI doesn't it ? (say it goes from -1.91 to -2.91) so how does it make it more stable with bigger numbers (or perhaps it's the other way round  ;D)

Scratching my head with all the numbers  :o

Yeah, you've got it backward. shimming to reduce porpoising and make the foil work better at higher speeds is shimming the front of the stabilizer to reduce the total incidence, in other words, to reduce the amount of up elevator that is built-in that helps beginners and people going slow to get their board up out of the water and flying.

Most axis foil/stabilizer combinations wind up with about 5 degrees total incidence, in other words, 5 degrees of up elevator. Shimming the front of the stab to reduce that to 2-3 degrees makes the porpoise calm down until you get going fast enough, and then it comes back, but it's more controlled.
I get that shimming the front of the stabiliser reduces the AOI to make it more stable at speed.
However shimming the the back of the stabiliser increases the AOI and makes the black series more stable. Sorry I still don't get that one. Because we always need SOME positive degrees for stability and lift like every airplane has? :o

Apologies for being annoying perhaps I should forget about shims induced confusion and just go short  fuselage and I'll get used to the pulses. Every foil pulses somewhat anyway!
It's a good point hobby horsing and too much lift are two different things. The 980 definitely becomes too lifty once it gets very windy for my weight. Looking forward to smaller HPS wings.

Wished axis would just clear this all up on their website....
« Last Edit: January 02, 2021, 04:04:42 AM by sydney.winger »

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Re: Axis Foils
« Reply #725 on: January 02, 2021, 04:21:46 AM »

I get that shimming the front of the stabiliser reduces the AOI to make it more stable at speed.
However shimming the the back of the stabiliser increases the AOI and makes the black series more stable. Sorry I still don't get that one. Because we always need SOME positive degrees for stability and lift like every airplane has? :o

You could hypothetically shim the front of the stabilizer, flattening it to zero incidence by the full 1.91 degrees and still have a .5 degree (positive) angle difference to the front foil because the front foil has an incidence of .5 degrees.

You will want to measure your own kit because even screw adjustments or sample variation can change these angles. 

Califoilia

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Re: Axis Foils
« Reply #726 on: January 02, 2021, 07:27:40 AM »
DW, is that a camera angle optical illusion...or are the fuse and bottom not parallel to one another?
optical illusion. Even the board looks very distorted to me.
Thanks. Figured as much, but just wanted to make sure you weren't holding out any super secret go fast and carve it up setup on us. ;) ;D
Me: 6'1"/185...5'1" Kings Foil Board...5'7" Kings Foil Board...9'6" Bob Pearson "Laird Noserider"...14' Lahui Kai "Manta"...8'0" WaveStorm if/when the proning urges still hit.

Califoilia

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Re: Axis Foils
« Reply #727 on: January 02, 2021, 09:02:39 AM »
What is actually confusing me is which way to the angles of incidence change with shims.

Admin posted this info a while back:
Quote
The 980 front wing has an incidence of +.54 degrees.  This is notable.  That is 1/2 of a degree !
The 420 rear wing has an incidence of -1.91 degrees (on the black fuselage only).

Shimming the back of the rear tail increases the negative AOI doesn't it ? (say it goes from -1.91 to -2.91) so how does it make it more stable with bigger numbers (or perhaps it's the other way round  ;D)

Scratching my head with all the numbers  :o

Hi Sidney,

The provided shim is a down shim.  The stabilizer in its stock position (no shim) is an inverted foil which already angles downward by 1.91 degrees in relation to the fuselage (and mast plate, and your board - if it has a parallel base and deck).  I just checked the shim that I received and it is accurate.  It increases the negative incidence by exactly 1 degree.  This shim increases that downward angle.  Using the measurements on my kit (which are duplicable every time) that takes me from -1.91 to -2.91 stabilizer incidence.
OK, I'll be honest...Sydney's not the only one confused by the terminology being used here and on the Axis site.

When we talk here about shimming the rear of the stab, and saying that "It increases the negative incidence by exactly 1 degree; that sounds as though that "decreases" the AOI by 1 degree (at least how I read it, and am doing the math)

However, on the Axis site, they identify shimming the rear of the stab as a "+1 Degree Rear Wing Shim". Which - again maybe just to me - sounds as though that is adding a degree of AOI....

...not decreasing it (-1.91 "+1 Degree" = -0.91 to me, not -2.91 as is being measured here).

Conversely, using the Axis "-1 Degree Rear Wing Shim" that shims the leading edge of the stab (that I run with the 900 front), doing the math gives me -1.91 "-1 Degree" = the -2.91 measured on Admin's table...but is the wrong shim as being discussed.

I think PB explained it best when talking about the entire AOI of the front and back wings combined....
Quote
Most axis foil/stabilizer combinations wind up with about 5 degrees total incidence, in other words, 5 degrees of up elevator. Shimming the front of the stab to reduce that to 2-3 degrees
...which at least makes sense in why shimming the leading edge with a "-1 Degree Rear Wing Shim" takes a degree out of the "foil/stabilizer combo", instead of screwing up the math of adding a degree in the trailing edge with a "+1 Degree Rear Wing Shim", and somehow going from -1.91 to -2.91...wth? ???

Just my simpleton way of understanding it all. :-[




« Last Edit: January 02, 2021, 09:04:20 AM by Califoilia (formerly - SanoSlatchSup) »
Me: 6'1"/185...5'1" Kings Foil Board...5'7" Kings Foil Board...9'6" Bob Pearson "Laird Noserider"...14' Lahui Kai "Manta"...8'0" WaveStorm if/when the proning urges still hit.

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Re: Axis Foils
« Reply #728 on: January 02, 2021, 12:02:53 PM »
Hi Cali,

I wrote almost that same thing back here: https://www.standupzone.com/forum/index.php/topic,35177.msg423502.html#msg423502 .

The naming of those shims is super confusing and is the opposite naming used by many other brands.  I am just calling it up-shimming and down-shimming.  The shim that Axis is providing with the 980 is the shim on the right in the image.  This stock shim is taking the already negative incidence of -1.91 and making it -2.91.  The shim angles the stabilizer further downwards.  This seemed counterintuitive to me as well but it is correct.

A few scenarios.

Dwight rides his with the stock shim.  He is at -2.91 degrees for the stabilizer.  He is using the shim in the right image.  I am calling that down-shimming.
I have been riding with no shim.  That is at the native -1.91 degrees for the stabilizer (no shim).
Jacky is riding with the shim in the left image.  That puts her at -.91 degrees.  I am calling that up-shimming. 
In all 3 of these instances the stabilizer still has negative incidence. 






« Last Edit: January 02, 2021, 12:06:56 PM by Admin »

DavidJohn

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Re: Axis Foils
« Reply #729 on: January 02, 2021, 01:06:47 PM »

Dwight (DW)

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Re: Axis Foils
« Reply #730 on: January 02, 2021, 02:26:15 PM »
These make great shims..

http://thedabbler.co.uk/2015/07/bread-clips/

Thanks! 

Where were you 6 hours ago when I made a 1/2 degree shim from aluminum  ;D. I feel so dumb now.
« Last Edit: January 02, 2021, 02:28:40 PM by Dwight (DW) »

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Re: Axis Foils
« Reply #731 on: January 02, 2021, 02:52:16 PM »
Hi Cali,

I wrote almost that same thing back here: https://www.standupzone.com/forum/index.php/topic,35177.msg423502.html#msg423502 .

The naming of those shims is super confusingand is the opposite naming used by many other brands.  I am just calling it up-shimming and down-shimming.
Yeah, remember it the simply by what I'm trying to do to the "lift" of the entire foil.

So if I want add lift to the entire foil I reach for a "+1" shim (raising the trailing edge of the stab) - if I want to decrease lift, I grab a "-1" shim (raising the leading edge of the stab). Positive increases, negative degreases lift...EZ-PZ. :)



Me: 6'1"/185...5'1" Kings Foil Board...5'7" Kings Foil Board...9'6" Bob Pearson "Laird Noserider"...14' Lahui Kai "Manta"...8'0" WaveStorm if/when the proning urges still hit.

PonoBill

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Re: Axis Foils
« Reply #732 on: January 02, 2021, 02:56:36 PM »
Since every manufacturer and every person joining the conversation seems to have their own terminology I just ignore it all.
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.

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Re: Axis Foils
« Reply #733 on: January 02, 2021, 03:55:28 PM »
Hi Cali,

I wrote almost that same thing back here: https://www.standupzone.com/forum/index.php/topic,35177.msg423502.html#msg423502 .

The naming of those shims is super confusingand is the opposite naming used by many other brands.  I am just calling it up-shimming and down-shimming.
Yeah, remember it the simply by what I'm trying to do to the "lift" of the entire foil.

So if I want add lift to the entire foil I reach for a "+1" shim (raising the trailing edge of the stab) - if I want to decrease lift, I grab a "-1" shim (raising the leading edge of the stab). Positive increases, negative degreases lift...EZ-PZ. :)

I hear you.  That is a reasonable way think of it.  Bill is right as well, with Armstrong and others putting it like this: https://www.armstrongfoils.com/tail-trim-fairings/ we are not going to come up with easy language for this.


Dwight (DW)

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Re: Axis Foils
« Reply #734 on: January 02, 2021, 05:33:18 PM »
Armstrongs labeling made my head hurt.

+1 for less lift
0 for more lift

WTF

I say who gives a crap what the numbers are.

Make the shims color coded or labeled. More Lift, Less lift. The End!


 


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