Here is a brood to the bird family. Related to the wingspan, it is a crossbreed of the
"Red Duck" http://www.thingiverse.com/thing:407766
and the
"Red Swan" http://www.thingiverse.com/thing:453090
Still small, but speedy and pretty manoeuvrable - a big fun for a real pilot.
Anyhow, Marcel, member of the ACNE http://www.aero-club-nieder-eschbach.de/
who piloted the maiden flight, had a lot of fun and this is his first impression:
"The small model is already very good, but some model flying experience is needed. For a wing type of this small size it flies even damned good. It’s not a plane for circling through thermics, of course it’s to small for that. The performance is shown when one flies it speedingly".

Uwe Heuer - experienced flying wing designer and Horton specialist - says about this square form of a flying wing, which he loves to call "panel plane":

"They do have a low damping and flight stability around the pitch axis (elevator), therefore you can fly snags in curves. This is why I love these “panel-planes”, these are also good-tempered against tilting to one side. But on the other side you pay that with the high sensitivity regarding wrong trimming of the CG and the elevator. During stall the wings stay level but for recovery they need a long dive to speed up again".

Besides my other planes it was flying at the InterEx 2016 in Versiox/Geneva
http://jivaro-models.org/interex_2016/index.html
They were very enthusiastic about of the speed which is possible.
But we dicovered that it is also posssible to land it slowly.

Here you can see how it flies:
https://youtu.be/d8cFB1equik
https://youtu.be/QrYqn8kItYM

This small plane is quickly printed.The biggest parts are 220mm high to print, but I also sliced them in half.

Wing fixating
Additional to fasten the wing with rubber band, it is important to secure it against sliding sidewards. You can do this by simply fixiating it with a short tape at front and at back to the fuselage.

Update 11.23.2015
Uploaded smaller wing segments:
wing middle left 110
wing middle right 110
wind left right 110
And smaller front fuselage segments:
fuselage front 1
fuselage front 2
fuselage interface front

Update 12.14.2015
Uploaded smaller back fuselage segments:
fuselage back 1
fuselage fback 2
fuselage interface back

Update 01.04.2016
Uploaded
winglet test 1 (1.5mm thick)
winglet 0.9 (0.9mm thick) which is successfully tested by "wytti"
print setting: three 0.3 solid layers

Update 01.07.2016
Wing fixiating and centering
"Scorpio 9999" made a good suggestion for improvement: Centering the wing by two little ribs on the bottom side of the middle wing part.
Thank you Scorpio!
I uploaded the files:
wing middle left 110 centered
wing middle right 110 centered
Additional I let the first files online in case anybody wants to extend the wingspan by simply add a wing section in the middle.

Update 01.21.2016
"Scorpio9999" published two parametric servo inserts for those who have different servos.
http://www.thingiverse.com/thing:1264902

Update 1. August 2017
Uploaded bigger stabilizer. They are 14% bigger
base 90 mm
top 66 mm
hight 140 mm

Update 2. January 2022
Miles870 asked me to enlarge the fuselage to fit for 28 mm motors.
I uploaded
fuselage front 28
access panel 28
access panel bracked 28

Specifications
airfoil: ClarkYS
wing span: 794 mm
wing chord: 160 mm
aerodynamic center 27 mm
wing overall weight: 270 g
wing area: 12.7 dm²
fuselage empty weight 75 g
fuselage overall weight 270 g
wing loading: 42.5 g/dm²
longitudinal stability (Thies) STFs:
motor: Turnigy 2632 Brushless Motor 1000kv
motor camber: -3°
side pull: 2° right
propeller: Aeronaut CAM Aeronaut Carbon Classic 9 x 6.5" / 23 x 16.5 mm
static thrust: 500 g (3S Lipo)
battery: Turnigy nano-tech 950mah 3S 25~50C Lipo Pack
ESC: HobbyKing YEP 30A (2~4S) SBEC Brushless Speed Controller
receiver: OrangeRx R615X DSM2/DSMX Compatible 6Ch 2.4GHz Receiver w/CPPM
servos: Hitec HS-55

Print Settings
Attention
The wings are designed to print with 0.5 width, 0.3 hight and 2 bottom and top layer, NO infill.
If you print thinner, the perimeter of the upper side will not merge with the perimeter of the inner spars.
If you print thicker, the perimeter will not be printed continuesly in one turn.
The print must go as if you print in spiral vase mode. So you reach at least a smooth surface on the upper side.
If needed, you must try with 0.49 or 0.48 width. It depends on which slicer you use.
The second thing is, if you print with less layer hight, the inner spars will not connect the top and the bottom layer. There will be a gap inbetween.

All parts: layer height =0,3mm, width =0.5 mm, NO infill
wing
1 perimeter, 2 bottom layer, 2 top layer, hollow
wing servo: 3 bottom layer, spiral vase mode
aileron base: 5 bottom layer, spiral vase mode
aileron end: 2 bottom layer, spiral vase mode
aileron appendix: 1 perimeter, hollow
aileron interface: no bottom layer, spiral vase mode

fuselage
Note: The extrusion width must be thick enough to prevent printing infill between the two perimeters of the 1mm hull. You must try out and check it in the preview.
I had to set the width to 0.53mm.

fuselage front: 7 bottom layer, 3 top layer, 2 perimeter, extrusion width 0.53mm, 20% infill
fuselage back: 3 bottom layer, 3 top layer, 2 perimeter, extrusion width 0.53mm, 20% infill
fuselage interface: 2 perimeter 0.4 no bottom/top layer, holow
fin: 4 bottom layer, spiral vase mode
fin cover plate: 2 bottom layer, hollow
The bigger fin:
0.3 layer hight
0.5 width
3 solid bottom layer, spiral vase mode
The bigger fin plate:
3 solid bottom layer
1 perimeter
10% infill