A good Fun-fly has to be small, agile, light and must be able to crash without damage. The delta wing has these criteria and does also allow the use of low cost wall isolation foam because of its mechanical characteristics. 

But to get the best out of your Pibros you need a programmable radio. 

Building instructions 

You need : 

Contact glue for foam in spray, a 3mm (1/8 ") thick foam sheet (size: 125cm x 80cm) and adhesive parcel tape 

Cut out the parts from the sheet as shown in illustration #1 (Take care of the direction of the fibers). For the parts 5,6, the elevons and the fin you can use some 6mm (1/4") foam or glue together two 3mm (1/8") foam sheets. 

Place parts 2 and 3 as shown in illustration #2 (Take care of the direction of the fibers) and tape them to part 1 (edge to edge ). 

Glue parts 5,6,7 and 4 on part 1 all at once with the contact glue on the untaped side (illustration #3). 

Keep the part 1 on a flat surface while gluing in place the surrounding of parts 4 and 5. 

Before gluing make a try fold of parts 2 and 3 over part 1 ( you'll need to slightly cut the edge of part 3 to avoid overlap on part 2). The parcel tape will make the leading edge. 

Put some glue on parts 2,3 and 5 and also on the trailing edge (1-2cm) of parts 2,3 and 1 

Refold parts 2 and 3 like before while keeping part 1 on a flat surface (leading and trailing edges) 

Make a straight cut on the trailing edge and tape the elevons in place 

Cut a groove between parts 2 and 3 and glue the fin into place 

Dig the foam to place the receiver, the servos and the batteries (illustration #4). Take care to place the batteries in order to obtain a center of gravity located at 210 mm of the nose without lead 

Fix the servos, receiver and batteries with double sided tape 

Make some 1 mm steel pushrods. They will be flexible enough to save the servos during crashes. 

Last but not least make 3 launching holes with a soldering iron through the wing as shown in illustration #4 and tape the upper wing side to avoid loss of air pressure . 

Flying 

The position of the Center of Gravity is slightly more critical than usual. Too far from nose, Pibros will not fly at all. Too near from the nose the max speed will not be reached and the agility will be just good for your grandfather. A good criteria for the Center of gravity is when inverted flight is obtained just by trimming down a bit. 

There are 2 ways of flying Pibros depending of the elevons throw 

Normal flight: +/- 20 deg at the ailerons and +/-10 deg at the elevators. Tued like this the delta is able to achieve up to 2 rolls per second and is flying pretty fast. 

Controlled stall flight: +/- 45 deg at the ailerons and +80 deg and -60 deg at the elevator with 90 % exponential. There you get a new flight dimension and quite a few unknown aerobatics are possible. Especially the instant air brake (pulling the stick at once) is amazing and very useful for landing at your feet in very strong winds. There is no inertia at all and you can start a left roll, change your mind and finish it on the right instantly. 

Pibros has been tested in very strong winds (70km/h) and is still flying well despite of its low wing loading. The fast reacting rudders are a good weapon against strong turbulence 

Just do it and have fun 

Mail us your best stories about Pibros.... 

Give a look at the photo gallery 

Specifications 
wing span: 800 mm 
length: 460 mm 
Airfoil: 4,5 % thichness, autostable with slightly trimmed elevons 
Surface: 20 dm2 
weight: 250 g 
Wing load :12,5 g/dm2 

Radio 
- 2 micros servos 
- electronically mixed elevators and ailerons 
- Exponential et Dual-Rate 
- Batteries 4x270 mAh 

Tunings 
C. of G. 210 mm 
from the nose 
Throws: see text 

Weights 
- 2 micro-servos: 40 g 
- 1 batterie 270 mAh: 70 g 
- 1 receiver: 30 g 
- Misc. (horns, pushrods, cables): 10 g 
- dépron: 100 g 
-Total: 250g 

Important  

For the first flight it is strongly recommended to use the small throws. A Pibros with a wrong center of gravity and or too much throw may be completely uncontrollable.Use dual-rates to test the new flight dimension. Despite it's simplicity the pibros is definitely not a beginners model and demands fast reactions from its pilot.