Here’s the latest member of the Park Jet series, the Saab JAS 39 Gripen. This design is very similar in concept to the F-18 and F-15 Park Jets, and uses the same construction methods and power setups. Like the other jets, it’s intended to be a park flyer built using simple construction methods and inexpensive and readily available components. It’s designed to be built almost entirely from either 6mm Depron or BlueCore foam.
Specs:
Wing area: 258 sq in
Span: 23.9 in
Length: 42.3 in
Weight RTF: 16.6 oz as shown unpainted (estimate 17.5 oz painted)
The flight performance of this model is excellent! The Gripen has the same wide speed range and excellent handling characteristics as the F-18 and F-15 Park Jets, and is surprisingly easy to fly. The biggest difference is that the Gripen is slightly less stable than either the F-18 or F-15 and is more maneuverable and quicker on the controls. Just like I suspected, the Gripen loves high alpha slow flight and is rock solid at sustained 30-40 deg alpha. I’ve been able to hold full aft stick and 1/4 throttle and watch the model crawl rock solid at very high alpha only a foot or so off the ground. The model can also do incredibly tight low-level turns with no hint of stalling by holding full aft stick and full throttle, just like a 3D ship. And of course it also flies well at high speed and easily flies as fast as I'm comfortable flying a foam airplane (about 50 mph). Just like the other Park Jets, the Gripen performs best with a power setup that provides 15-20 oz static thrust and 45-50 mph pitch speed.
But the best part about flying the Gripen is that the double delta planform looks just awesome in the air--almost like a spaceship. SINISTER is the best word to describe it! It’s just a thrill to watch this model fly.
Currently, I recommend flying the Gripen with mixed canard/elevon flight controls for pitch. This model is set up so that full aft stick deflects the canard trailing edge down 3/4" and the wing elevons trailing edge up 3/8”. This setup provides excellent pitch control at both high speed and low speed and good stall characteristics. However, I do intend to test other mixing combinations to see if anything else works better. My model also has rudder control, which is optional but invaluable for providing directional control during high alpha flight.
By the link on the left you can download the archive in which, in addition to drawings, also decals and complete instructions for assembling a radio-controlled aircraft model JAS 39 Gripen Park Jet
Amigo parabéns pois esse aero é mto bom estou a baixar a sua planta porem tenho algumas duvidas do tipo:
- Onde fica e como achar o CG - O motor sendo na calda e a bateria na frente onde se posiciona o esc teve que estender o cabo do esc ou o cabo da bateria ate chegar no esc - Pode usar motor de 2200 kv com hélice 7x4 ou 6x4 - teria como aumentar a escala pois queria montar esse projeto com 0.80 cm de asa
Agradeço por sua atenção sou RODRIGO BARRETO e moro na cidade de Campos dos Goytacazes - RJ / BRASIL CONTATO: tsbarreto1@gmail.com / igu.k9@hotmail.com
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