Symetrical Kfm Inspired Wing.

[JasonK]

Testing out a Kfm inspired wing design, however with a more complicated layering to create a front edge that is closer to a NACA-00xx airfoil shape then the very blunt front edge that I ended up on the split elevon design. This is just to test the airfoil, I am not currently planing on testing any yaw control setup.

Here is the profile build up I did to test the general idea:



I am using nearly the exact same layer template, except I am cutting off 1/2 of the leading edge of the middle layer to account for the fold over of the outer layer to get nearly the same airframe profile. The outer edges will not be as 'rounded' as they will only be 2 layers thick, and will be unable to get quite the same level of shaping (at least not without cutting deeper into the middle layer then I want to on this test).

CG calculation from the split elevon design clearly pushed the CG farther forward then needed, I will measure the CG point from the prior attempt to use as an initial testing point for this wing.

 

[JasonK]

Reserved for build log/notes

similar basic build as the split elevon wing, just wing some modifications so I could wrap the outer layer around the front of the wing to create a more rounded/smooth front edge to the airfoil. I should have drafted the parts on the computer instead of off the cuff on the paper, ended up with a bunch of bad fitting spots on the wing that I had to fill with scraps. I also used hotglue on everything on this wing to get the build to go faster (and much faster did it go... almost felt like speed running a wing build to this point).

 

[JasonK]

first off... I think the space I was maidening it in was a bit small, hard to fly straight for very long and there was a reasonable clip of wind coming across from the far field side, over/around that large building, which would have been making the are more turbulent.
I forgot to 'sync' the cameras [IE clap in front of both], so I lined them up as best as I could, but they are likely slightly out of sync.

Flights:

1. It wanted to roll right really bad and was very pitchy... got it landed then added some left aileron and moved the battery as far forward as possible to try to make it less pitchy.
2. Flipped down my rates switch, but IIRC had issues controlling roll and ended up putting it back on high rates
3. I don't recall any specific thoughts
4. FPV - flew ok, but was still touchy on the controls, it was hard to make smooth/slow rolls

The wing was much smoother in flight then the very blunt nosed kfm wing from the split elevons test. It flew level at less then 50% throttle. Not sure if my throws/rates are off or if I should be moving the CG slightly more forward. It will definitely need another test or two to fully test out its flight characteristics.

I also want to figure out if the left trim I needed to put in, is an 'all the time' trim (something with the air-frame/control rod lengths/etc) or if it is torque related (and should have some throttle mix into roll to counter it).

 

[JasonK]

reserved for final thoughts