Official Freewing JAS 39 Gripen 80mm EDF Jet

[kallend]

I usually go straight from take-off into high alpha to retract the gear at low speeds, then I proceed with the flight. ;)

I go gear up as soon as there's no way to abort to the runway, which is generally immediately after liftoff since our runway is short.

[jasmith41]

I usually go straight from take-off into high alpha to retract the gear at low speeds, then I proceed with the flight. ;)

That's because you're a crazy man... 🤣🤣🤣👍

[Airguardian]

I usually go straight from take-off into high alpha to retract the gear at low speeds, then I proceed with the flight. ;)

[Radar-Guy]

Hello,
I can not find the post now but now O got the same problem as others, the gear door will not be closed when you retrac the landing gear. what is the solution to this? I do not see that something is bent or so.

My Gripen is 8s powered and it always happens when I don‘t retract the landing gear ASAP after take-off, it’s obviously related to higher airspeed. When it happens, reducing the airspeed and cycling the gear helps every time.

[The swede]

Thanks Evan D, I will check that! I didn’t know where to start 😁

[Evan D]

On mine it’s a sign to tighten the set screws holding the strut to the retract.

[The swede]

Hello,
I can not find the post now but now O got the same problem as others, the gear door will not be closed when you retrac the landing gear. what is the solution to this? I do not see that something is bent or so.

[Hugh Wiedman]

...and for those among you who might be interrested, i just uploaded my cockpit *.stl-files to thingyverse, just put Freewing and JAS39 into the search bar and you should be able to find them, cheers

Outstanding, and your 3D HUD display is spectacular!

[WarbirdFan66]

and here something from my workbench, just a little bit of detail work to pass the winter time...

...and for those among you who might be interrested, i just uploaded my cockpit *.stl-files to thingyverse, just put Freewing and JAS39 into the search bar and you should be able to find them, cheers

[Airguardian]

[WarbirdFan66]

and here something from my workbench, just a little bit of detail work to pass the winter time...

[Airguardian]

regarding flaps - forgive me but for some reason I thought it was possible to do something like flaps if I offset the pitching down of the elevons with some pitching up on the canards. maybe that's too risky.

That's what the full scale jet does for landing configuration. Be careful of implementing that in the model as it will likely make your plane stall at a smaller AoA and probably make it quite a bit more 'unstable' feeling, potentially worsening wing rocking. That's for a setup with no gyros. If you are using gyros, then it can be a bit tricky to make a setup like that work properly unless the gyro is designed to do it.

where do you get those missiles?

Freewing MiG-29... so not quite scale, but practical as I have them around and like better how the plane flies with them on.

[xviper]

thank you that is good info. because of this, I set the canard mixing to the aileron function to a lower rate, so that it doesn't deflect very much for roll while still keeping the pitch mix at 100. hopefully this is a reasonable compromise.

I am really terrible at programming spektrum! everything seems to function fine, but if I try to program AS3X or SAFE, the flight modes don't respond to the flight mode switch. instead, they seem to be matched to elevon controls because if I move the elevon stick it switches between mode 2 and 3. flight mode is set to stick F, and it changes the flight mode on the main screen, but has no effect on gyro modes. I am lost yet again.

This may or may not be relevant to your particular situation. Last year, I was trying to dial in gains and priorities on a friend's plane. We buggered around with it for over an hr and a half. Finally, something clicked and it all worked. Like you, the flight mode positions didn't seem to affect the actual degree of gyro effect. I think what happened was ................... first, you must decide whether or not you want to use fixed or variable gain. If you use variable gain, you must assign that function to the rotary knob. If you keep it on a switch, nothing changes. If you decide to use fixed gain, then you can use a switch, BUT that switch must be assigned. You can't have fixed gain on a rotary knob and you can't have variable gain on a switch. Once I declared fixed gain/priority on an assigned switch, it all worked. Of course, you have to end the session by "saving" (or something like that) the values. If you just exit, none of your numbers and switch assignments get recorded.

[Cfreuen20]

"Better" is not well defined - different people are looking for different things.
That said, canards are not efficient in roll for several reasons: (1) they are too close to the centerline to generate a large rolling moment as compared with elevons; (2) the outflow from the canards changes the AoA of the wing center section in the direction that opposes the rolling moment (unlike the case with tailerons), and because of (1) and (2) the canards have to be deflected more in order to produce any sizeable rolling moment, resulting in more drag.

thank you that is good info. because of this, I set the canard mixing to the aileron function to a lower rate, so that it doesn't deflect very much for roll while still keeping the pitch mix at 100. hopefully this is a reasonable compromise.

I am really terrible at programming spektrum! everything seems to function fine, but if I try to program AS3X or SAFE, the flight modes don't respond to the flight mode switch. instead, they seem to be matched to elevon controls because if I move the elevon stick it switches between mode 2 and 3. flight mode is set to stick F, and it changes the flight mode on the main screen, but has no effect on gyro modes. I am lost yet again.

[kallend]

has anyone actually confirmed that the plan does indeed fly better with the canards only doing pitch, or is James' setup actually fine? I want to do pitch only because that's what the full size does, and I'm inclined to trust the brilliant engineers who designed the real thing.

"Better" is not well defined - different people are looking for different things.
That said, canards are not efficient in roll for several reasons: (1) they are too close to the centerline to generate a large rolling moment as compared with elevons; (2) the outflow from the canards changes the AoA of the wing center section in the direction that opposes the rolling moment (unlike the case with tailerons), and because of (1) and (2) the canards have to be deflected more in order to produce any sizeable rolling moment, resulting in more drag.

[Cfreuen20]

When I first got this plane, I had all control surfaces working together (pitch and roll on the canards) and all going through a gyro. I didn't feel it was needed (it also looked "too busy"), so I took some of it off.

has anyone actually confirmed that the plan does indeed fly better with the canards only doing pitch, or is James' setup actually fine? I want to do pitch only because that's what the full size does, and I'm inclined to trust the brilliant engineers who designed the real thing.

[Cfreuen20]

thanks, guys

[Evan D]

I have Johns missiles on both mine. Had Suko’s sidewinders but like the IRIS-T a bit better.

[kallend]

where do you get those missiles?

I have no idea where he gets his missiles, but here are some IRIS-T for the Gripen: https://www.thingiverse.com/thing:4706132

and here are some Sidewinders: https://www.thingiverse.com/thing:4653284 Also some underwing pylons: https://www.thingiverse.com/thing:4713773

[xviper]

Personally, I used two of the big missiles from my Mig29. Mine's in the foreground.