Purito 2m

The Purito is probably the best 2m build-it-yourself model currently available. A direct descendant of the Pures and the Slight the Schweiger family concern have optimised the design as far as possible with current (2020) CNC technology. The main design change is to a lower aspect ratio wing to increase the Reynolds Number and give better overall performance and particularly nice handling. Despite the larger wing the weight has been kept the same, resulting in a lower wing loading and excellent performance in weak conditions.

The Purito flies like a homesick angel and despite its light weight the model has a surprisingly good speed range. As Greg wrote in the RCGroups thread "The big wing bestows a good launch, even when the wind is light; the airplane itself has little drag, so displays very good legs; handling is easy, allowing the pilot to concentrate on thermalling; and finally, the spoilers really make spot landings quite easy."

The amazing wing is the major improvement of this design. The main spar is a substantial carbon tube which gives the structure excellent rigidity. A multitude of ribs are threaded over this tube to give the airfoil shape. This is even better maintained over the critical front portion by utilising two sub-ribs between each full rib, almost eliminating covering sag, and reducing drag appreciably. Becuse the tubular spar is inset below the covering surface there isn't a discontinuity at the spar line which is great feature - this usually trips the boundary layer and causes extra drag.

The kit is beatifully made up with excellently CNC cut balsa and ply parts. The wing is built over/in a 3D jig which ensures all the ribs are perfectly placed and aligned. This can be seen in the clear photos in the Purito German Build Manual. In addition to the manual, full size plans are povided for the tail surfaces. English speakers should refer to the RCGroups Purito thread for detailed build info and Google translate the German text if necessary. Also use Google Translate on this very useful RC-Network.de Purito thread. Before building please checkout this link to the latest manuals and translations.

Purito Specifications
Wing span	2.0 m	78 in
Wing area	39.7 dm2	615 sq in
Length	119 cm	46.9 in
Flying weight from	440 g	15.5 oz
Wing loading	11.1 g/dm2	3.6 oz/sq ft
Aspect ratio	10.0
Wing airfoil	AG35-38 modified
Dihedral (EDA)	11.0º
Centre of Gravity	75-80 mm from wing leading edge
Controls	Rudder, elevator, spoilers

Purito Typical Weights
Bare structure	300 g	10.6 oz
Covering	50 g	1.8 oz
Total structure	350 g	12.3 oz
Wiring	6 g	0.2 oz
Receiver	6 g	0.2 oz
Rudder servo	5 g	0.2 oz
Elevator servo	5 g	0.2 oz
Spoiler servos (2)	10 g	0.4 oz
Battery	55 g	1.9 oz
Noseweight	3 g	0.1 oz
Flying weight	440 g	15.5 oz

Recommended RC
Rudder & elevator servos	Blue Bird BMS-101DMG, Blue Bird BMS-101HV, Blue Bird BMS-A10H, KST X06, Graupner DES 427, ES08
Spoiler servos (2)	Blue Bird BMS-101DMG, Blue Bird BMS-101HV, KST X06, Graupner DES 427, ES08
Receiver	4 or 5 channel receiver to match your transmitter
Battery	Radient 1S 700 mAh LiPo, Dream-Flight 300 mAh 4.8V NiMH, HyperFlight 650 mAh 4.8V NiMH, Dream-Flight 700 mAh 4.8V NiMH, 1S 2600 mAh Li-Ion, 2S 300-600mAh LiPo

Control Throws
Rudder	20 mm each way
Elevator	10 mm up & down
Spoilers	80º - 90º up
Hook location	4 mm from front of cut-out