DIY onestrut kite

[Europ2]

Pics:
Sail
Leading Edge

Some very detailed guides for DiYers. Thank you

[kitexpert]

Your instructions behind the links are excellent, PanTau - even though I don't understand it fully because of my weak German skills. Pictures of course help. When I saw a picture where you had aligned three stitch zigzag when doing 90 degree turn I was a bit amazed

Your trick to align segments and start cutting from the biggest is nice. Unfortunately it doesn't work with Sp.

[PanTau]

Your trick to align segments and start cutting from the biggest is nice. Unfortunately it doesn't work with Sp.

One of the many reasons why I implemented my own software to model the kites and create the plans

[kitexpert]

Yes, Surfplan (at least free version) is not nearly a perfect design program. I have already had to develop some unconventional ways to use it to overcome some of its limitations, but many are still there. However so far I'm using it.

How is your design program now, are you going to release it for public use like your plans?

[PanTau]

How is your design program now, are you going to release it for public use like your plans?

Sure!
But it's a lot of work to build a nice web ui to define all the parameters and render the 3d preview in the browser. Still in alpha status and not supporting all the features yet. But winter is coming!

[lovethepirk]

Question for Hansen or PanTau or anyone else for that matter. When I was goofing around with modeling a kite I ran into a problem of the tangency of the airfoil guide lines coming off the leading edge. This is because if you build the guidelines from a plane that travels on the front view of the kite then when you slice the leading edge into segments you are working with an ellipse not a perfect circle. The top two pics are using this method to build the guidelines correctly I believe. I can then make a guideline coming off the ellipse tangent, but for some crazy reason I can't get the mesh/sweep/etc to lay tangent to the Leading edge. I've tried every tool I know and just can't get it to lay down correctly.

The obvious wrong method would be to use a plane that travels on the same path the LE travels on which is depicted in the last photo. I consider this very wrong, just wanted to mention it. Is my method of constructing the planes by which you build guidelines off of correct? Seems the best method considering this is the direction the wind is traveling over the sail.

BTW this design isn't for a build, what I was wanting to do eventually was try to do a fluid dynamics test on it and see how different profiles changed lift and drag. Prob one of those projects you never get to

[kitexpert]

Sure!
But it's a lot of work to build a nice web ui to define all the parameters and render the 3d preview in the browser. Still in alpha status and not supporting all the features yet. But winter is coming!

Question for Hansen or PanTau or anyone else for that matter. When I was goofing around with modeling a kite I ran into a problem of the tangency of the airfoil guide lines coming off the leading edge. This is because if you build the guidelines from a plane that travels on the front view of the kite then when you slice the leading edge into segments you are working with an ellipse not a perfect circle. The top two pics are using this method to build the guidelines correctly I believe. I can then make a guideline coming off the ellipse tangent, but for some crazy reason I can't get the mesh/sweep/etc to lay tangent to the Leading edge. I've tried every tool I know and just can't get it to lay down correctly.

The obvious wrong method would be to use a plane that travels on the same path the LE travels on which is depicted in the last photo. I consider this very wrong, just wanted to mention it. Is my method of constructing the planes by which you build guidelines off of correct? Seems the best method considering this is the direction the wind is traveling over the sail.

BTW this design isn't for a build, what I was wanting to do eventually was try to do a fluid dynamics test on it and see how different profiles changed lift and drag. Prob one of those projects you never get to

I'm sure PanTau or Mr Hansen could answer your questions better, but I have a try. I've been thinking LE structure lately quite a lot.

Your "obvious wrong method" seems right one to me. I would like LE sliced always by angle bisector, no matter how it turns. I don't think direction of air flow has any significance to LE structure, only how it is easiest and strongest to build matters to me.

If you slice LE like in top two pics cutting surfaces are ellipses, like you wrote. Surfplan does it this way. Difference from sphere is biggest near wingtips where double curvature (swept back wingtips) is biggest.

Hope you learn something from your tests. However practical things matter a lot in kites, but of course it is good to know basics of physics also.

[kitexpert]

I think I'll print this one tomorrow. There's a different bridle but I haven't decided which one I'll use. I checked all seam positions and bridle points and made some minor adjustments here and there.

[PanTau]

I think I'll print this one tomorrow.

Nice kite!
You should increase the (build in) AoA at the center. At least from the pic it looks like the aoa is very low.
If the build in aoa is too low the trailing edge flutters all the time. Very annoying...

Since my Ventus is very similar to your design I could also create the Ventus 2.0 with three more segments for you.

[kitexpert]

I haven't print it yet (new laptop, old printer -problem) so I can still add build in AoA.

With foil kites I've been decreasing build in AoA continuously, because if it is too high it limits depower and makes kite slower. Also my relative high panel count comes from foil kites where 16 cells (panels) is very low. AFAIK higher build in AoA makes kite gruntier and more stable, and for sure decreases TE flutter like you said.

It is a bit difficult to decide how much, but I'll add some build in AoA to the design. Perhaps more than flutter I'm worried stability and possible tendency to fly too far and then hindenburg.

You could make a design with more panels and segments, if not for me but for general interest. I do have kites which have quite few parts and they fly fine, so I don't know how big advantage smoother shapes are after all. Of course the fewer the parts are the less work there is and kite will be a bit lighter in weight also.

Thank you again for all of your help with this project