Author Topic: Longer Fuselage for Stability and Pump  (Read 1009 times)

Beasho

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Longer Fuselage for Stability and Pump
« on: November 22, 2022, 09:38:39 AM »
Contrary to the conventional “Go Shorter” on fuselage I am proposing To Go Longer.
 
My objective is to catch More Waves, Smaller Waves and Bigger Faster waves on a SUP Foil.  I have found that BIGGER boards can do all of this better than SMALLER boards.  The challenge with bigger boards is pump-ability.  So in an attempt to match the resonant frequency of Bigger SUP Foil Boards, meaning 5’ 6” – 6’ 0” board in small waves or 7’ – 7’ 6” boards in big waves, we might want to go back to longer fuselages.

I have been using the Crazy Short Axis 644 mm / 25.3 inch fuselage.

Prompted by a discussion on the Swim Missiles thread I called Sam P’ae and had a 45 minute conversation on the benefits of LONGER fuselages for stability and pitch control.  For me this would be most interesting in Big Wave scenarios – Thinking 10 foot faces with a standard Fuselage 784 mm / 31 inches long.
 
Ideally you can use a long fuselage with a LITTLE tiny tail.  Think Flying Wing with a Carbon Arrow for stability. 

Beasho

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Re: Longer Fuselage for Stability and Pump
« Reply #1 on: November 22, 2022, 09:38:58 AM »
I wonder if a windsurf fuselage would work better for this. My thought is more pitch stable, so easier gliding. Anyway, worth remembering if pitch control is difficult.

I reached out to Sam Pae awhile back, asking about boogie foiling. He said it was the most difficult version of foiling. Sam would not be able to try a windsurf fuse because it would tear his legs up.

Thank you DW!  :)

When I called Sam he said that the Windsurfing fuselage would move the wing forward which was NOT ideal.  SO he acquired a damaged Axis Regular Fuselage 31" and added 4" by having someone weld a mid-section to the fuselage.  AKA 787-10 Extended Length. 
« Last Edit: November 22, 2022, 10:02:37 AM by Beasho »

Beasho

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Re: Longer Fuselage for Stability and Pump
« Reply #2 on: November 22, 2022, 09:45:21 AM »
My interest is NOT just stability but also maintaining pump.  This past summer I got better at pumping, doing doubles and triples on a 6' x 30" x 110 liter SUP Foil board. 

We have a local 'young guy', 34 years young Kyle who suggested that a longer fuselage would better match the cadence of a (his) bigger board.  He is a phenom having only been foiling for 15 months but fully mastered Prone, then SUP foil, Flat water pump ups, board building, Wing Foiling and is now dragging us all by the hair to go Downwinding with him in San Francisco Bay, or the Ocean from Half Moon Bay to the Ritz . . . 

He noticed this with his 6' downwind board.  When surfing it in faster, longer period swell the longer fuselage lets him GLIDE for a longer period when pumping out and approaching incoming swell.  His long fuselage is the "Short" = 703 mm / 27.6" vs. the Ultra Short = 644 mm / 25.3" fuselage.  In the Bay when downwinding the Ultra Short better matched the shorter period tight swell, even on the same board. 

I am leaning towards getting the Regular fuselage which is 784 mm / 31".  This would be for Bigger Waves on my 7' 4" x 31" L41 or the 7' 8" x 25 Clark board.  In a perfect world this lets me take off on big waves, glide really well AND when the wave starts to dissipate drop off the back and pump to the wave behind to continue the Insanity.  Axis 999 with 300P tail (or maybe smaller and smaller tail). 

To quote Kyle "On a big wave you're going too fast to turn you just want to blast away and keep it all together with a stable platform. . . . all these guys who are talking about shorter fuselages and turning are doing it on tiny boards in baby little waves." 

Thoughts ?
  ???
« Last Edit: November 22, 2022, 10:03:32 AM by Beasho »

Beasho

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Re: Longer Fuselage for Stability and Pump
« Reply #3 on: November 22, 2022, 10:07:38 AM »
Here is a successful example of what I am trying to do.  Catch a fragging-big wave and IF I can't make the drop, kick off the back and go get the one behind it.  Here was a wave from last spring at Mavericks.  I was on the Axis 999 with 375P tail. 

I have been tweaking this L41 board, by giving myself more front foot range, to move my foot backwards, with a longer front strap.  This should enhance pump-ability.  AND If I can take off slightly earlier, or wider I may be able to access more big waves from the shoulder without risking death or destroying all my gear.  Possibly even with BIGGER foils like the Axis 1099 for earlier lift off.   

https://www.youtube.com/watch?v=OWyzfz-1Bvk
« Last Edit: November 22, 2022, 10:10:20 AM by Beasho »

PonoBill

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Re: Longer Fuselage for Stability and Pump
« Reply #4 on: November 22, 2022, 10:52:42 AM »
A little more forward wing might help pumping some, but windfoil setups were originally designed to plug into tuttle boxes intended for fins--way back at the tail. Some of the new windfoil boards have tracks or turtles in a more forward position and use more conventional fuselages. Most are still more wing-forward than SUP foils because the mast base is roughly in the middle of the board and applies a lot of downward force.

There's no question that longer fuselages are more pitch-stable and don't require as big a stabilizer. I tried a tiny modified axis stabilizer. I had conveniently broken off half of one side of a 440 stab, so I made a dinky little arrow fletching out of it. It worked really well except for turning. The turn radius was parking lot sized. This was back in the 1020 dayz, so your mileage may vary with more sophisticated wings. It was also fairly hard to get up and going, though back then I was struggling with everything. When I get back to Hood River I'll make an ultra-long fuse like Sam's and build some tiny stabs for it. Of course by then you'll have figured this all out.
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: Longer Fuselage for Stability and Pump
« Reply #5 on: November 22, 2022, 02:24:24 PM »
In smaller waves, I'm on the crazyshort 600mm advanced fuse.  Its awesome and pumps just fine once you get used to it.  There are some very nice advantages on the pump side - getting over waves (especially steep ones) works well because you can "aim" the board up over and back down.  With a longer fuse, its a lot harder - I either slam the board into the top of the wave because I went in too low, or if not then I often breach out the backside.  The other advantage to the really short fuse for pumping is I can get it up high on the mast with one swoop.  With the longer fuse, I have to pump a few times to work up high on the mast.

All that said, pumping with the standard fuse is easier and definitely has a lower cadence.  Also much less sensitive to mistakes (forgiving).  I think you're on the right track for big fast waves.

Beasho

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Re: Longer Fuselage for Stability and Pump
« Reply #6 on: November 22, 2022, 03:41:44 PM »
All that said, pumping with the standard fuse is easier and definitely has a lower cadence.  Also much less sensitive to mistakes (forgiving).  I think you're on the right track for big fast waves.

So STANDARD is 'Easier'??

Its also about matching the pump cadence to the harmonics of a longer board.  This may explain why I felt it more advantageous to just paddle vs. pump this past summer.  Because my 6' SUP monster didn't want to pump as fast as it needed to for the Ultra Short 644 mm and the 300P tail. 




frenchfoiler

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Re: Longer Fuselage for Stability and Pump
« Reply #7 on: November 22, 2022, 11:06:30 PM »
For SUP foil DW I've been using the Axis short fus, I used to go with the ultrashort but I found the longer better, more control, more glide especially with longer boards such as my 6'4 and 7'6.
I tried the ultrashort with my dw 7'6 and I could feel the pitch, I was loosing too much control.

But for surfing small wave I go with the new adv crazyshort, the pumping is quicker and off course it turns better so it suits my 4'6.

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Re: Longer Fuselage for Stability and Pump
« Reply #8 on: November 23, 2022, 12:41:50 AM »
Super interesting!  Question: has anyone experimented with mast directly mounted to front wing.  It would change some dynamics for sure but by shaping the wing differently at the midpoint, you could still set the mast connection aft as needed.  Then the only function of the fuse would be supporting the rear wing (no mast connection and greatly reduced load from offset leverage) and it could be much less substantial, even for super long fuses like this.  A stiff carbon box tube would work.  That way we could changeout lengths super easily as above.  Fuses are super heavy and this could eliminate almost all of that weight.  I am going to build this.
« Last Edit: November 23, 2022, 12:50:38 AM by Admin »

PonoBill

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Re: Longer Fuselage for Stability and Pump
« Reply #9 on: November 23, 2022, 09:25:25 AM »
There was a guy I used to see at Ka'a who had a flying wing design. No stabilizer, directly mounted to the mast with a substantial sweep to the wings. He could make it work, and it seemed to turn super well, but it looked unstable in every direction and it wasn't great in any other way I could see. That was pre-wingfoiling days, I haven't seen him any later than that. I doubt it would pump well, or if it did it would be like a jackrabbit.

Still, we should test that. My guess is that it would pitch like a donkey, but it's just a guess. I should ask Adrian Roper about it. I suspect he's tried everything he can think of, and from my discussions with him, he's thought of a lot of crazy shit.

You may recall the incredibly stupid Geezer Foil I built. Surface-piercing wings mounted on the board in front and a single wing in the back directly mounted on the mast. Besides having drag like a sea anchor and leaping out of the water at less than walking speed with 250 pounds on it, it looked like it wouldn't turn at all. Weight distribution made no difference, it went straight. I'd be slow to take any conclusions from that. The only lessons I really learned from that thing was if you're going to stray a long way from standard practice, check your math at least five times, and build a small model first.
« Last Edit: November 23, 2022, 09:28:38 AM by PonoBill »
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: Longer Fuselage for Stability and Pump
« Reply #10 on: November 23, 2022, 01:21:19 PM »
So STANDARD is 'Easier'??

I probably should have said "More Forgiving".  I don't mean to say that you expend less watts, but more that it is more user-friendly.  You can recover from mistakes easier, which is what usually cuts my multi-wave attempts short. 

Beasho

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Re: Longer Fuselage for Stability and Pump
« Reply #11 on: November 23, 2022, 09:49:31 PM »
So STANDARD is 'Easier'??

I probably should have said "More Forgiving".  I don't mean to say that you expend less watts, but more that it is more user-friendly.  You can recover from mistakes easier, which is what usually cuts my multi-wave attempts short.

Today I was on the 999, hoping it wouldn't break, on the 7' 4" L41.  Definitely slow and lethargic on the Ultra Short, with 4 ft @ 17 seconds.

Ideally the longer fuselage will get me more mileage off the back of a primary wave to jump to the next wave, and maybe the next.  I will say that I was able to hold it all together on steeper 6 to 8 foot faces, fly with the nose down as if the foil was NOT even there.  Then wait and transform into flight mode.

More to come. 

PonoBill

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Re: Longer Fuselage for Stability and Pump
« Reply #12 on: November 24, 2022, 07:56:56 AM »

Today I was on the 999, hoping it wouldn't break, on the 7' 4" L41.  Definitely slow and lethargic on the Ultra Short, with 4 ft @ 17 seconds.

Ideally the longer fuselage will get me more mileage off the back of a primary wave to jump to the next wave, and maybe the next.  I will say that I was able to hold it all together on steeper 6 to 8 foot faces, fly with the nose down as if the foil was NOT even there.  Then wait and transform into flight mode.

More to come.

That's the primary characteristic of the 999, and the reason I love mine, though there are other elements of it that I don't love. You can cause the 999 to react to swells, or to act as though they weren't there. I don't have any theories as to why that's so, but I know all I need to do to do the feeble hop that I think of as jumping to think "let's jump this one" and if I want to slice through as though the swell wasn't there, just think "let's not".
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.

sflinux

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Re: Longer Fuselage for Stability and Pump
« Reply #13 on: November 24, 2022, 08:14:35 AM »
I think you are on the right path Beasho.  Reminds me of when Laird started using the Air Chair, then he later adapted the design going longer on the strut and fuselage with smaller wings.  Going longer in the fuselage will allow you to go smaller in the tail, for less drag, so more distance/ pump.  I would think that a longer fuselage will have the feel of a surfboard with a longer rail, which I prefer for bigger, faster waves.
I would think that the distance you want to maximize is the relative distance between the leading edge of the front wing to the leading edge of the stabilizer wing.  If you move the leading edge of the front wing further away from the mast, you will change the center of lift, which will affect the box placement of your board.

In your quest to go longer, have you tried the Axis standard?  It is ~140 mm (5.5") longer than the one you have been riding.
How do the fuselage lengths of other manufacturers compare?  I know Lift offers a 3" (76 mm fuselage extention)  But what is the length of their standard fuselage?
Alchemysurf makes some adapters, i.e. axis to lift adapter.
https://alchemysurf.co/products/axis-to-lift-adapter
And foilparts sells an axis mast to lift adapters:
https://www.foilparts.com/
« Last Edit: November 24, 2022, 08:22:31 AM by sflinux »
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Re: Longer Fuselage for Stability and Pump
« Reply #14 on: November 24, 2022, 10:09:00 AM »
There was a guy I used to see at Ka'a who had a flying wing design. No stabilizer, directly mounted to the mast with a substantial sweep to the wings. He could make it work, and it seemed to turn super well, but it looked unstable in every direction and it wasn't great in any other way I could see. That was pre-wingfoiling days, I haven't seen him any later than that. I doubt it would pump well, or if it did it would be like a jackrabbit.

Still, we should test that. My guess is that it would pitch like a donkey, but it's just a guess. I should ask Adrian Roper about it. I suspect he's tried everything he can think of, and from my discussions with him, he's thought of a lot of crazy shit.

You may recall the incredibly stupid Geezer Foil I built. Surface-piercing wings mounted on the board in front and a single wing in the back directly mounted on the mast. Besides having drag like a sea anchor and leaping out of the water at less than walking speed with 250 pounds on it, it looked like it wouldn't turn at all. Weight distribution made no difference, it went straight. I'd be slow to take any conclusions from that. The only lessons I really learned from that thing was if you're going to stray a long way from standard practice, check your math at least five times, and build a small model first.

This is what I am going to build.  It keeps the stabilizer.  I started a new thread so as not to pirate this one.  https://www.standupzone.com/forum/index.php/topic,38282.0.html

 


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