Official Freewing JAS 39 Gripen 80mm EDF Jet

[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.

[xviper]

you are correct I do only want pitch control on the canards, but was under the impression I couldn't get that on my DX8G2 with stabilization, so just to mess around I thought about trying James' setup to see if I liked it.

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.

also, your response just made me realize what mistake I probably made- I think I probably plugged the first canard into aux1 and the second into aux2 which is why one isn't responding. I feel dumb. I'm going to go take a look to confirm my shame.

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. This is on a DX8G2.

[Cfreuen20]

That's smart. I like the exacto knife idea. :)

Well, anyway... time for some more ass-kickin' Gripen rippin'!

where do you get those missiles?

[Cfreuen20]

I thought you only wanted elevator (pitch control) on the canards? Next, why are you "deploying flaps"? There are no flaps on this plane, thus, the default flap switch needs to be INH. Also, flaps is usually defaulted to AUX1. He's got nothing plugged into AUX1. Somehow, you've got "flaps" and a switch coming into play in your TX. There shouldn't be any flaps or a switch to control them.

you are correct I do only want pitch control on the canards, but was under the impression I couldn't get that on my DX8G2 with stabilization, so just to mess around I thought about trying James' setup to see if I liked it.

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.

also, your response just made me realize what mistake I probably made- I think I probably plugged the first canard into aux1 and the second into aux2 which is why one isn't responding. I feel dumb. I'm going to go take a look to confirm my shame.

[Airguardian]

That's smart. I like the exacto knife idea. :)

Well, anyway... time for some more ass-kickin' Gripen rippin'!

[HockeyMac!]

Nicely done!
What strategy did you go with to pull the thing out in the end?

I took an exacto and cut the foam out around the plastic mount. I would then wiggle the mount to find where there was still glue and cut/remove until it wiggled out. As for the reinstallation, I used a dremel to shave down the sides so it could fit flush in the rear of the bay. Glue was applied to the wood tray and foam. It seems quite sturdy but we'll find out once the landings start happening lol. In the meantime, it seems like every gray I find is too dark a match for the Swedish colors :(

[xviper]

First, James has full aileron and elevator function on the canards with that mix. I thought you only wanted elevator (pitch control) on the canards? Next, why are you "deploying flaps"? There are no flaps on this plane, thus, the default flap switch needs to be INH. Also, flaps is usually defaulted to AUX1. He's got nothing plugged into AUX1. Somehow, you've got "flaps" and a switch coming into play in your TX. There shouldn't be any flaps or a switch to control them.
You can still do the ELE only on the canards if you use just the mix for ELE>AUX2 and ELE>AUX3, but then, you wanted gyro control on the canards and this will NOT allow that. You need to pick which one you want ........................... ELE on the canards or gyro control on them. You can't do can't do both with the RX you've chosen.

[Cfreuen20]

Hey guys, here is the Spektrum mixing on mine.

First, I have model setup for elevon in aircraft type:



then,
I have my left elevon in the ail port,
right elevon in the elevator port
right canard in aux 2
left canard in aux 3



It shouldn't truly matter which elevon is plugged into which AIL/ELE port or which canard is in which AUX port as the mixing will be similar as long as your 2 elevons are in the ail/ele ports and your 2 canards are in 2 aux ports. Once your there it's just playing within the mix as to going 100% or -100% and watching what happens.

So, you see my 4 mixes, 2 for ail, 2 for ele landed as such...



Again, I have the canards in aux2 and aux 3. I have mixed 1 elevon (from the ail port) mixed into both canards separately to control the roll, and 1 elevon (from the ele port) mixed into both canards separately to control the pitch. Here are each mix page:






I hope this helps, its really not hard at all. Within each mix all I did was set (elevon) > (canard) and move the rates to either full 100% or -100%. Took no more than 5 minutes.

She is all ready to fly tomorrow (had rain today). So excited to let you guys know how she goes and obviously videos will come soon afterwards.

I just can't seem to get this to work right, everything except the left canard seems to be functioning correctly. the left canard is not working for any pitch or roll functions, but it does function when I deploy flaps. however, the right canard doesn't function during the flap function. this confusing.

has anyone else experienced this?

[Airguardian]

I did quite a bit of work to keep the weight down, but also shift the CG further back. As you can see below, I flipped the nose gear around, ty airguardian for walking me through this

Nicely done!
What strategy did you go with to pull the thing out in the end?