the "Malabar" mixer test for large foilkites in light wind

[foilholio]

tested a version of it and relaunch doesn't work, more later.

[Regis-de-giens]

I just copy here the comment I initially did to Zimmerman on A18 topic to keep the whole discussion here and because I see a potential safety issue with Zimermann's mixer proposal:

"Hallo Deutschland !

I understand your idea to push the concept even further. Maybe it is better you transfer this discussion on the dedicated new topic viewtopic.php?f=197&t=2391403 to keep this post focussed on a18 ... and people not following A18 can ls get your idea.

I'll wait for your sketch, but at first sight I have 2 preliminary remarks, including safety :
1- amplification should be approx x1.5 rather than x3 (to be confirmed with your sketch)

2- but most important : bridle A has normally higher tension than bridle C, hence there is a risk of total instability: indeed A bridle position is no more directly imposed by front lines and can become longer than what the rider ordered (it will "rotate" as you say but shorten C more than ordered, and therefore with a slack in the C). => uncontrolled higher AoA than ordered from the bar, so overpower, up to backstall (in the best case...).

It could be very dangerous (kite back-stalling in full middle of the window, then rotates back to normal position in one second (possible since flight direction of the kite has reverted), then BIIIIIIG jump ... so be careful if you decide to test it :
- light wind with a lot of safe space downwind
- small kite with a release system not connected on a front line in that case as releasing on B with a balanced connection to A and C can be useless and dangerous ...)
"

I have just changed pressure ratio to x1.5 as I finally think swapping from Malabar to Malabar-Zimmermann will reduce bar pressure.

[Kiter_from_Germany]

Hi Here is the Guy from Gerrmany, again.
Last Night I did the drawing regarding a discussion about mixer systems.
Regis-de-giens rose a discussion on a - on my behalf great idea - changing the mixer systems (and the connection points of flying and steering lines) of kites.
The Malabar design discusses the possibilities of moving the steering line connection point from position Z to C. With an intelligent mixer setup this will result to better steering performance.
On my behalf (and this is just from an intellectual point of view - It could be a good idea to move the flying line from A to B.

To combine everything we would now have four possible mixer setups:
Conventional (Connection A and Z)
Conventional_B (Connection B and Z).
Malabar (Connection A and C)
Malabar_B (Connection B and C)

To give a better understanding here is a drawing. You see a drawing of Conventional_B and Maalbar_B design:

Variant_Mixer_Systems.png (18.86 KiB) Viewed 2185 times

Regis-de-giens quoted back security and safty remarks - which I think are right (...mostely ).
So the Malabar_B maybe not the right mixer setup for the standard attachment points of kites we see on the market. For improvement of a standard kite, I see no chance anymore, thanks, Regis-de-giens.
But the Conventional_B and Malabar are to setups, which I really like and will give a try.

Regis-de-giens quoted a risk of side effects caused by lateral forces as I understood.
Very good hint, I gonna get deeper in it, at the moment, from the aerodynamical point of view I see the underpressure points mainly at position B, secondly at position C but not at position A?
Regis - Help me!
(Problem: if A will draw stronger than C we get in a little trouble because we loose the wing profile - which is - let's say 'bad').
Nevertheless, a very interesting question, I thing I have to test it ...
(unfortunately I just sold my old flysurfer, and wait for a pansh maschine.... so I've to wait!

[foilholio]

If you look back a couple posts I replied to your A15 post here with a mock up of what I thought you were describing. Which is the same as you have pictured on the right. I don't think it will work as there is nothing to create tension on A to depower the kite. ABC will all balance and the kite will be permanently powered.

I tested a Malabar version, only difference is that I ran the Z pulley line off A main and not the front main as in the original malabar. I don't really see much potential for improvement including B. What happened, the kite doubles in bar pressure which is really quite strong, reminds me of some inflatables I have tried. The bar throw halves which is interesting, on a big kite it would be nice. Relaunch wont work at all. I shouldn't be surprised, I am not really, when I think how it could possible work and it couldn't. A and Z reach a point of equilibrium about C. The wing becomes very flat and wont move past that point of flatness. Pulling on the rear lines just pulls on the whole kite.

So thats that, was interesting...

[Regis-de-giens]

Relaunch wont work at all.

I have just 2 words ... Shit & shit . That was THE potential issue, it is actually, and I cannot see a way to mitigate this relaunch problem . Pfffff....

So, if you feel that the turning speed and depower improvements were useful (and if bar pressure you was not to high for your convenience, but it was acceptable on the Aurora 22m), the alternative for you is the pulley-bar .

It is not complicated to modify most of existing control-bars, and with some concept thinking you can envisage to easy swap from normal-mode to pulley-mode depending on wind range.

Thank you for having tested the Malabar anyway .

[Kiter_from_Germany]

If you look back a couple posts I replied to your A15 post here with a mock up of what I thought you were describing. Which is the same as you have pictured on the right. I don't think it will work as there is nothing to create tension on A to depower the kite. ABC will all balance and the kite will be permanently powered.

I tested a Malabar version, only difference is that I ran the Z pulley line off A main and not the front main as in the original malabar. I don't really see much potential for improvement including B. What happened, the kite doubles in bar pressure which is really quite strong, reminds me of some inflatables I have tried. The bar throw halves which is interesting, on a big kite it would be nice. Relaunch wont work at all. I shouldn't be surprised, I am not really, when I think how it could possible work and it couldn't. A and Z reach a point of equilibrium about C. The wing becomes very flat and wont move past that point of flatness. Pulling on the rear lines just pulls on the whole kite.

So thats that, was interesting...

Hello,
thanks for beeing here in this very interesting discussion.
Foilholio, you are definately right goning through a test phase before recommend it.
My idea about this discussion is much before that recommendation - just find some guys going into those things.
You did a great work in testing different setups not only about their primary airodynamic effect, but also in their usability (relaunch, reverse etc). Very much thanks for that!
Everyone of you all brings things ahead - and after all - perhaps - you (or we) find some ideas how to improve a little.

My little cent in this discussion is thinking about effects of moving the main lines connection points and discuss their effect. In die Malabar we descussed the movement of steering line away from the Z line to C line (with an appropriate Mixer setup of course).

At the moment I like the elegance of let the wing turn around B point (by moving flying Line connection point from A to B. This results in an -1/2 : 0 : 1/2 : 1 deviation ratio of mixer system(left drawing). I didn't see that in the discussion till now, did I oversee something, or are they A fixed?
In relaunch capabilities I learned the significance of a Z connection. I dont think A connection is so important for that, so maybe there is a way to improve steering rate witchout negative issuses?
The possible side effect regis remarked - balancing issues between A and C I do not see from a theoretical point of view - so Ive to test that (when Im able to )

foilholio - Megatester: Do you have an idea about that Conventional_B setup? I unfortunately have no foil kite in the cellar, (selling then buying is the wrong sequence I say, but my wife says: it is! And she is always right, by definition..) So, if you can state a first impression, it would be fine, otherwise we have to wait till Feb until I can 'Pansh' it!
F...k - just saw the B-Position from pansh a15/18, "nicely" far back in the wing profile... hmmpf - where is my old Speed 2, I like to pimp it!

[foilholio]

Conventional_B is going to have the same problem of not depowering. A and C are stuck in a fixed relationship, you can alter it by pulling and adding more power. But this might work.

9.jpg (19.32 KiB) Viewed 2126 times

BC Auto adjusts, Bar throw should be shorter.

[Regis-de-giens]

I do not hink that this last number 9 with change bar throw nor depower.

Bad consequence will be that B and C can freely rotate , so camber will be uncontrolly change (at first sight B longer and C shorter since on main kites B tension is higher than C tension). So lack in performance and certainly stability degradation in my opinion.

i do see no other solution than either a pulley bar (or a malabar with 2 additional lines that goes from Z directly to the bar with enough slack and that you tension to relaunch ... not beautiful at all ...)

[foilholio]

Z can still be adjusted in relation to BC, giving a more stable vs less config,(note reflex/camber changes do not need to just be at C location but can be anywhere). It is just that BC will always find their own balance. From what I have seen with the malabar this will be flat and in not anyway distorted, it should work well in theory. I think the potential for better performance exists as the BC relationship will always be constant. There should definitely be more depower/ shorter throw as B is now 1/2 instead of 1/4. It is basically turning the kite into just ABZ.

But I will test, as always!

[Kiter_from_Germany]

Hello together,
is a little tricky all this stuff.
Foilholio,
sometimes I may oversee the obvious.
Till now I was just looking at the principels of the mixer gear, overseeing, that in modern kite design the adjustment points are designed for conventional mixer design. The B line is not connected at the point were the profile is the thickest - its way behind it.
For the problem which rises here is the drawing (with the connection points of Pansh A15, but Speed 4ff should be pretty similar.
Let's take a look at the conventional mixer design, everthing fine:

Conventional.png (35.4 KiB) Viewed 2026 times

The problem in changing the mixer setup is resulting in a problem of profile integrity if we go to conventional_B design (thanks für your hint, regis) and we will perhaps not be able to depower at all (thanks foilholio), without flipping the kite:
To see the problem, hier is the drawing of conventional_B:

Conventional_B.png (35.8 KiB) Viewed 2026 times

After all I would say, that with such connection points, we are in trouble.
To pimp an old Speed 2 there may bei a chance to test Conventional_B, because of his "standard" connection points....

Only way I see in modern kites (with their connection points), is to implement a third pulley and reduce the deviation of A to 1/8 (-> half lateral force, C should manage that).

Conventional_B8.png (36.84 KiB) Viewed 2026 times

But I still dont like that - B is too far back...
Thanks for you all, folks, I wait till February, we will see....