I just made a new radicallyshort +77mm advanced fuselage prototype. This fuselage is 450mm long and has the mast move forward +37mm in comparison with the standard Axis Advanced ones that are already +40mm. I hope this will inspire others to make some experiments!

This is very cool....

Guess this is the advantage of aluminium fuses.

Would be great if the fuse was fully adjustable.

Mast slot could have multiple positions with gap filled in using plugs.

Tail length could have multiple mounting points, then trim what you don't want.

Love the desire for a radical unstable setup with super small stabs.

Very cool. I have an old axis red standard fuse. I'd like to reduce the length. Any tips for the easiest way to do this? I obviously don't have a desk mill, but perhaps a local maker space?

On the mount, did you consider matching the axis tail mount? I see you went flat which seems sensible if you have other tails

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Steven F said..
This is very cool....

Guess this is the advantage of aluminium fuses.

Would be great if the fuse was fully adjustable.

Mast slot could have multiple positions with gap filled in using plugs.

Tail length could have multiple mounting points, then trim what you don't want.

Love the desire for a radical unstable setup with super small stabs.

They should definitely do that for poeple to find what suit them. For me the next step is to completely chop off the tail fuselage and replace it by a single flat carbon piece that act for the rear fuselage and the stab.

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cornwallis said..
Very cool. I have an old axis red standard fuse. I'd like to reduce the length. Any tips for the easiest way to do this? I obviously don't have a desk mill, but perhaps a local maker space?

On the mount, did you consider matching the axis tail mount? I see you went flat which seems sensible if you have other tails

Mounting the axis fuse would be even easier as the bottom is already flat. I would just sand down the height in order to reduce the "rudder" effect.

regarding the tools to do this. I think you will need to find a mill. Mine is the smallest mill that exists and it still did the job. Maybe you could do it on a press drill if you use small miling tools.

Looks like you enjoy it for carving but how is the stability, there must come a point where you start to loose the trade off, like reducing the length of a motorcycle for tighter turning, when you end up with a grom bike it becomes unstable at speed

Cool project.....i like riding my ART 899 but are not really satisfied with the turning.
I also have a Naish Foil and they have the front wing so much closer to the mast similar to this +77mm Axis "customization" since the "beginning"......and are still also beginner friendly with the right foil and even my first huge Naish foil for my first wing foil attempts with more than double of the area of the ART899 was better in turning then my current Axis Set Up

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sultanofwing said..
Looks like you enjoy it for carving but how is the stability, there must come a point where you start to loose the trade off, like reducing the length of a motorcycle for tighter turning, when you end up with a grom bike it becomes unstable at speed

So far, there is zero problem with stability. I plan to do a phase 2 where I replace entire rear part of the stab by something lighter and thinner. So I agree with you that it can be too short, 45cm is not there yet. :)

Have you tried running it with no stabiliser. Maybe that is the end game for you but jokes aside it might be interesting to feel the extreme end of the equation if you haven't already?

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Powis said..
Have you tried running it with no stabiliser. Maybe that is the end game for you but jokes aside it might be interesting to feel the extreme end of the equation if you haven't already?

I have... no stab is too unstable. The sweet spot is somewhere between 45cm and no stab :)

Nice work. That bench top mill must be awesome to have I'm sure it was not cheap.

Maybe this is a dumb beginner question (s) but... What does shortening the fuselage accomplish, that a smaller size stabilizer does not? Why would you want one over the other?
I understand how repositioning the mast forward changes things.

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Fishdude said..
Nice work. That bench top mill must be awesome to have I'm sure it was not cheap.

Maybe this is a dumb beginner question (s) but... What does shortening the fuselage accomplish, that a smaller size stabilizer does not? Why would you want one over the other?
I understand how repositioning the mast forward changes things.

You are right... definitely not cheap!

The stab size affects the pitch stability, i.e., the stability against forward-backward movements.

The fuselage length affects both the pitch stability and the rotational stability, i.e. the stability against rotations around the vertical axis. If you want a nervous foil that makes sharp carved turns, you need to be able to counter-steer it in order to carve. This is where you want to want to minimize rotational stability by shortening the fuselage length as well as its vertical dimensions.

As you pointed, the other aspect is the mast position; A mast far behind the front wing makes it hard to turn the foil around the versional axis as the mast acts acts as a fixed rudder that prevents you from rotating the foil around a vertical axis that goes through the front wing.

New prototype where I bolted the front wing directly into the mast

I machined the fuselage slot further forward in my black standard crazyshort fuse. I now have something almost identical to the advanced sillyshort (same overall length as the non-advanced crazyshort).
Its really short, but definitely fun to ride on both 899, 999, and 1099. I'll probably not go any further forward with the mast right now because I'm already tapped out at the front of the boxes on my board

By the way, all this stuff reminds me of anglefoils from 5 years ago. getting the mast forward does really open up the yaw capability of the foil

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jagoulet said..
New prototype where I bolted the front wing directly into the mast

Here is what the final prototype looks like. It is 2.15kg complete with all void filled with with epoxy and foam.

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jagoulet said..

This is really awesome stuff. It would be great if you could talk a bit about what tools you use in general to make all the measurements, angles, machinery, etc during the whole development process.

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Here is what the final prototype looks like. It is 2.15kg complete with all void filled with with epoxy and foam.

Nice work. With V1 to 3. Any thoughts on the drag of your V3 setup vs original? ie. The fuselage shape and/or the 3-way front junction.

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Emmett said..

Here is what the final prototype looks like. It is 2.15kg complete with all void filled with with epoxy and foam.

Nice work. With V1 to 3. Any thoughts on the drag of your V3 setup vs original? ie. The fuselage shape and/or the 3-way front junction.

I have not rode them side by side in a same session but I suspect that the difference in drag is small. The main thing is the increased manoeuvrability that is evident.

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mindhoc said..

jagoulet said..

This is really awesome stuff. It would be great if you could talk a bit about what tools you use in general to make all the measurements, angles, machinery, etc during the whole development process.

I will try to make a video about it soon.

Is V4 will be the mono wing?Have you try the mono wing to compare?

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NordRoi said..
Is V4 will be the mono wing?Have you try the mono wing to compare?

V4 will not be a mono wing. I have tried the Triton T1 last week and the current model is not suited for winging as it does not pump nor glide. That means that as soon as you let the wing go, you feel a drastic reduction in the speed and there is no way to rely on pumping to move forward. Therefore, you can only surf big waves with it. Regarding manoeuvrability, I would say that I feel more locked in with the Triton T1 than with my V3, whereas my V3 glides and pumps (thanks to the fantastic ART799). That being said, I am sure that there is a lot more developments possible around mono wings, yet I can imagine that this development is not trivial.

For the V4, my main objective will be to cut drag. I would like to have seamless integration between an adapter-free mast, the front wing and the current carbon-tube fuselage from the V3. That will require designing and building a completely new part from scratch and possibly switching to another mast brand (e.g., Cedrus) where I could have the mast without any adapter at the end.

On the medium-term, I am looking forward to have <2kg complete foils.

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jagoulet said..

New custom board to be specifically tailored for the RadicallySHORT V3. 140cmX47cmX3cm~19L. For reference the burgundy KT drifter S is 4'10 33L. Notice how the tracks have moved forward so that the front wing and the mast that is on top of it are centerer on the board. This is intended to increase maneuverability by reducing the rotational inertia of the board that increase as you move away from the centrer.




The board was build by Flikka in Slovenia and is a scaled up version from my Horue Caneri pro (106cmX44cmX3cm, ~12L, 1.5kg). At 2.85kg it turns out heavier than I expected... I should have been more specific that I wanted it ultralight. The shape is intended to provide the same riding position as with my kitefoil pocked board, but with extra tail length and width to allow taking off comfortably in 15kt.

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jagoulet said..

The shape is intended to provide the same riding position as with my kitefoil pocked board, but with extra tail length and width to allow taking off comfortably in 15kt.

Brilliant, great to see how you build what you see in your mind. I ride a GF FTS 14.5 tail and I find it is very reactive and turny, I wonder if you have ridden the Go Foil kit, your mods certainly seem to ride good, thumbs up

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sultanofwing said..
Brilliant, great to see how you build what you see in your mind. I ride a GF FTS 14.5 tail and I find it is very reactive and turny, I wonder if you have ridden the Go Foil kit, your mods certainly seem to ride good, thumbs up

:) I have not tried GF foils, but this is the spirit... shorter fuse, smaller stab!

FYI I believe when the mast is in line with the front wing you will benefit from a bulb on the front of the foil hydrodynamically. Check the americas cup boats and the moth foils. Actually a moth foil company makes an 800 foil for axis that has a bulb on the front.

I'll go and measure my fuse to tail to see how long it is, but @jagoulet by going so short aren't you losing the ability to make pace through pumping, what I love about the GF FTS 14.5 is I can turn how I want (kind of like riding a 600cc sports bike) but I can also keep pace by pumping, sometimes for quite a while if the gust just drops off

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JohnnyTsunami said..
FYI I believe when the mast is in line with the front wing you will benefit from a bulb on the front of the foil hydrodynamically. Check the americas cup boats and the moth foils. Actually a moth foil company makes an 800 foil for axis that has a bulb on the front.

I will look into it whether the gain you have on a straight line does not bring adverse affects when carving or through the additional weight