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Freewing JAS-39 Gripen

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  • Freewing JAS-39 Gripen


    The Freewing JAS-39 Gripen is a delta wing aircraft with a canard configuration. It can also be assembled and flown in several different configurations and this makes for an interesting model. A vector thrust unit is also available as an option. You will have to make a decision before you start the assembly if you wish to incorporate the vector thrust unit into your model.

    The vector thrust unit has to be fitted first. It’s glued to the front half of the fuselage in a similar way to many other Freewing and Flightline models. However, if you assemble the model as the standard version without the vector thrust unit it would be an almost impossible task to remove the standard tailpipe to fit the VT unit. My suggestion would be to have two fuselages one with the VT unit and one without if you first assemble the model in its standard form. The VT unit also requires 2 extra channels on the transmitter and the receiver to operate it, and this will mean a minimum of a 9channel transmitter.

    In its standard form, you will require a minimum of 7 channels to operate the elevons and the canards. The channel assignment is as follows. Aileron, elevator, rudder, throttle, retracts, canard 1, and canard 2. The elevator and ailerons are mixed as elevons and the canards operate as both elevators and ailerons both being mixed with the elevons. It may seem complicated but Motion RC has a video on the website that explains exactly how to program a Spectrum transmitter and also a Futaba. The VT unit requires one left and right mixed with the rudder and the other up and down mixed with the elevons and canards. The operation of the VT unit should be on a separate switch so it can be switched on and off as you want it. You will find there are no instructions covering the installation and operation of the VT unit. This is left entirely to the pilot to set up however you feel comfortable with it. Having said that there is a video on the Motion RC website covering the setup and operation of the unit. However, you will need to adjust it to suit your style of flying.

    The assembly of the model is typical Freewing and it can be assembled in about an hour and another hour or maybe a little longer if you have never flown with canards before. The quality of the finish is excellent on the model I have. It was picked off the shelf as a regular sale and shipped as normal free shipping.

    With the VT unit fitted and the model finished ready to fly the battery will need to be secured as far forward as possible to obtain the correct CG position. You will also have to have the nose cone and the canopy fitted, it is that close. Without the VT unit, the CG won’t be an issue at all.

    The day I chose for the test flight was really far from ideal with the wind blowing a steady 25MPH gusting to almost 30 at times. In fact, I waited for what seemed like half a day to see if the wind would reduce, but it didn’t.

    With a fully charged 6s 6000mAh battery, I lined up into the wind and pushed the throttle forward. The model accelerates quickly and the take-off was not an issue even in the 25MPH wind the model flew flawlessly. It should be noted I am flying the model WITHOUT a gyro, and I had no problems with the flying characteristics at all. Reducing the power into a headwind the model will almost come to. A standstill with the nose quite high. However, you won’t be able to achieve the same flight characteristics on a calm day. I didn’t play with the VT unit on this occasion in such windy conditions.

    All-round an easy to assembly, and a great flying model.

  • #2
    Congrats.

    Some notes... First I find it interesting you (and a couple others) call the TV's VT... Second I find your battery position interesting. I have two Gripens. One is 8S and has TV. I fly it with batteries weighing 880g and even fully back I had to add weight to the tail to get a proper flying balance (the book CG is quite nose heavy). I also have 3D printed sidewinders on it which help add tail weight . #2 is stock 6S without TV and flying with even 575g packs and added missiles I have a few ounces of lead in the tail.

    One recent mod made to #2 is to replace the servo horn on the canard servos with longer ones to get more travel so I can get proper air brakes. Both mine have airbrakes and they work wonders to reduce roll out after touch down.

    The Gripen is by far my favorite plane as shown by having the two above plus a third spare in the box.

    Click image for larger version

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    • #3
      Not sure why we have two Gripen threads, but. . . . .

      Mine is running 2 gyros, one on the elevons and the other on the canards and TV. It holds very high alpha like it's on rails.

      Click image for larger version

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      • #4
        I also take issue with this statement:

        "With the VT unit fitted and the model finished ready to fly the battery will need to be secured as far forward as possible to obtain the correct CG position. You will also have to have the nose cone and the canopy fitted, it is that close. Without the VT unit, the CG won’t be an issue at all."

        Most of us have found that without the TV unit the CG is way far forward unless weight is added to the tail.

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        • #5
          I assume you didn’t read my post?

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          • #6
            I suggest we move this back over to the proper thread. Not sure why PappaBear created a whole new thread for this one post of his, with some interesting information...

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            • #7
              Originally posted by Evan D View Post
              I assume you didn’t read my post?
              Was admiring the wingtip missiles in the lower photo.

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              • #8
                onboard my 8S powered Gripen:

                (still having issues with gear door closing correctly...working on it)HET 700-60-1865 / JetFan 80RT 45C 4500 4S X 2HobbyWing 150A ESCRuncam2 4K

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                • #9
                  Anyone any ideas when the Thrust Vectiring kit might come available. I'm stalling on buying the Gripen in case it never does come back.

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                  • #10
                    Originally posted by Tabdy View Post
                    Anyone any ideas when the Thrust Vectiring kit might come available. I'm stalling on buying the Gripen in case it never does come back.
                    They are in stock now at both Motion and RC Castle.

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