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Official Freewing JAS 39 Gripen 80mm EDF Jet

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  • Originally posted by janmb View Post

    Doesn't the set of videos we have seen this far provide some idea?

    I used to love going large batteries in every model I had, but have realized more and more that increased capacity gives very little real increase in flight time. More weight makes the model less efficient and spends that energy faster. What it does do though is make the model heavier and at least in some respects fly worse.
    Exactly what I am thinking and I am wondering if the 5000 pushes the flight characteristics of the Gripen into the realm of less favourable. If the 5000 is a manageable size for the Gripen and increases the flight time then I will get than one. If it is too weighty then I will go with the 4000. I just want to get best bang for the battery buck with this plane.

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    • I'll not claim to be the most efficient with the go fast stick, but none of my 80mms that are deltas do much better than 3:00 useful throttle time on a 4000, or 3:30-3:45-ish on a 5000 with high 3.7's ending cell voltage. However, flying longer is not my main goal.

      I've not tried the new 9-bld setup, but might be good for 10%-20% more than the 12-blds.

      I like to fly 80mms with 4000's for less weight. A lightweight 5000 doesn't really buy you much vs. a good 4000 and heavy 5000's start to negatively effect flight characteristics I want in the models I fly. The Gripen with its light wing loading may be less effected, but there will still be an effect.

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      • +1 on keeping it light. Another thing to keep in mind is that if concerned about getting good CG, 4000 will quite certainly cater better to that than 5000, which will make it hard to avoid being nose heavy.

        (obviously don't positively know that for this model yet, but based on past experience it is a pretty safe assumption)
        Freewing A-10 turbine conversion: http://fb.me/FreewingA10TurbineConversion

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        • From the looks of James' build video, if the heavier VT tail end is used, a 5000 battery will balance the plane nicely.

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          • Whats the best way to fly it with a 6 channel transmitter?

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            • Ok so far what Ive gathered is that I should use the back elevons as elevons and the canards for pitch, with only six channels available. But what would happen if I used different control layouts? For example; elevons for only roll, and canards for only pitch? Or, what if I used canards for pitch and roll, and elevons for only roll?

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              • .....And here is a video from FRNC. The first 50 seconds or so of the flight footage is out of focus, but it comes right after that.



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                • Originally posted by Monty500 View Post
                  .....And here is a video from FRNC. The first 50 seconds or so of the flight footage is out of focus, but it comes right after that.


                  Some observations that I missed in earlier videos:
                  1. Looks much nicer with missiles on those wing tip rails.
                  2. The sound emanating from the plane while flying is very reminiscent of my Dyson cordless vacuum cleaner - high pitched whine.
                  3. Roller skate sound from the wheels when rolling on the ground.
                  4. This one didn't go SPLAAAT on the maiden.
                  5. He never put the "pedal to the metal" - actually flew it rather sedately.
                  6. Who or what is "FRNC"?
                  7. Gotta have one.

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                  • That video shows the jet to be super nose heavy and trimmed with canards... about the worst thing you can do to a canarded delta IMO.
                    Leave canards enterpoint flat and trim with elevons!
                    That works better! (Definitely does on the Eurofighter and you can expect the Gripen to behave likewise).
                    And move CG back for heaven's sake... it pains me to look at the model flying like that.

                    Originally posted by Pegg00 View Post
                    Ok so far what Ive gathered is that I should use the back elevons as elevons and the canards for pitch, with only six channels available. But what would happen if I used different control layouts? For example; elevons for only roll, and canards for only pitch? Or, what if I used canards for pitch and roll, and elevons for only roll?
                    Very bad options.
                    Elevons are meant to be the main control surfaces, if you are not using them for pitch AND roll, you will cripple the jet's capabilities and lack authority in many scenarios, potentially leading to a well deserved crash if you do :)

                    Whatever you do, elevons MUST work in pitch and roll, everything else is a secondary concern.

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                    • Originally posted by xviper View Post
                      6. Who or what is "FRNC"?
                      FN-RC is a group of guys in Taiwan I believe. Back in the day they used to hand craft special order aircraft. They actually created the 70mm F-104, and then collaborated with Freewing to mass produce it. Don't know if they're still doing special orders, but they seem to get all the new Freewing planes before anyone else due to their proximity to the Freewing production facility. Freewing always releases some kits to the local market at the same time they load the containers for the US and Europe, that's why we're seeing vids from them before they arrive here.

                      Originally posted by xviper View Post
                      7. Gotta have one.
                      I am making a prediction that shipping notices will start going out tomorrow. (No, I don't "know" anything for sure, this is just a prediction on my part )
                      Pat

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                      • Originally posted by crxmanpat View Post
                        I am making a prediction that shipping notices will start going out tomorrow. (No, I don't "know" anything for sure, this is just a prediction on my part )
                        Hope you're right! I have a 4 day weekend ahead with a PERFECT weather forecast...

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                        • Really wanting TV on this one and it’ll go in storage until they get shipped...

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                          • Originally posted by crxmanpat View Post
                            I am making a prediction that shipping notices will start going out tomorrow.
                            May the fates hear this and deliver!

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                            • A lot sooner than "late October" would be a pleasant surprise.

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                              • Originally posted by Evan D View Post
                                Really wanting TV on this one and it’ll go in storage until they get shipped...
                                Same here. I'm not gluing the stock tail on and then have to tear it apart to put the VT tail on. They shoulda packed all the VT tails in with the pallets of Gripens.

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                                • I'm repainting mine when it gets here, so I'll work on that while waiting for the TV unit.
                                  Pat

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                                  • Me too but I’m not going to break out my painting stuff and then pull it all out again later,.

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                                    • Originally posted by Evan D View Post
                                      Really wanting TV on this one and it’ll go in storage until they get shipped...
                                      Same here. Why MRC won't allow a pre-order of the TV is a mystery.

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                                      • Originally posted by crxmanpat View Post
                                        I am making a prediction that shipping notices will start going out tomorrow. (No, I don't "know" anything for sure, this is just a prediction on my part )
                                        Aaaaand... the Fates did listen!
                                        Today I received my MiG-29 shipping notice!

                                        Wait, what do you mean this is the Gripen thread?

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                                        • LOL! Guess I need to go back to my day job. I obviously suck at making predictions.
                                          Pat

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