Official Freewing JAS 39 Gripen 80mm EDF Jet

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[QUOTE=Airguardian;n286277]No-music video edit of my first proper high-alpha flight attempts:

Thank you so much for your kind words!
Means a lot to me!




The fullscale jet can accelerate faster than our model.
The fact that ours doesn't pack a comparable punch makes it look more toyish IMO instead.
[/

[kallend]

My set up.....chinahobbyline 6s5000 65c 839g. 3 1/4 oz of stick on lead on the bottom of the tail cone to get the cg at the mold.marks.

Use my "heavy nozzle" and you can hide all the weight (up to 120g) from view.

https://www.thingiverse.com/thing:4650359

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I’ve had stick on lead weights come unstuck before and that was on the inside of the plane, don’t think it would be much fun if it came off the outside so far back

[sschenck75]

I found a Gripen Jas-39 setup that should work well with Spektrum (6) channel receivers & AS3X. All the setups I previously tried, required reversing one canard (getting them in the same direction). I have smaller servo reversing modules but since Spektrum does Not recommend them with AS3X, I ended up just re-wiring one servo

setup for Elevons and pitch only for Canards:

1. First, I re soldered one Canard servo to get the Canards working in the same direction.
2. Then choose Dual Aileron setup/normal tale.
3. Next, plug one wing into the Aileron port and the other wing into Aux1 (flap), reverse one port to get the Ailerons working in the right directions.
4. Lastly, create one Elevator to left Aileron mix and use 100% in each direction (turn on trims), use a 3 way connector for the canards in the elevator port.

I have full trim in all directions, canards require initial manual centering. AS3X works for roll only on the Elevons and works for pitch only on the Canards. to me this seems like a decent compromise and I have some stabilization on all control surfaces. I will flight test tomorrow and see what happens?

My initial flight was using the same receiver with an Elevon setup (instead of dual aileron) and pitch only on the Canards via an elevator/flap mix (canards using the flap-aux1 port). AS3X worked in all directions for the Elevons but I had no AS3x on the Canards. The flight was successful but I had a bad case of the wing wobbles. I have my AS3X gain on a roller knob and had to drop the gains to 10% to stop the wobbles, effectively turning off AS3X. Although I have Not flight tested this latest setup, it appears to be better than the original Elevon setup. I have never setup AS3X on a delta wing and perhaps having AS3X combined with pitch and roll on Elevons, requires very low gains? If anyone else has tried the Dual Aileron setup or has any ideas, I would appreciate the input.

[HaroldAnderson]

I’ve had stick on lead weights come unstuck before and that was on the inside of the plane, don’t think it would be much fun if it came off the outside so far back

His nozzle has a sleeve section and is pressed onto the foam at the rear of the plane. Mine would almost have stayed on without glue but I glued it on with Foam-Cure. It will have to be ripped off for removal . It's not falling off unless you forget to glue it or cartwheel the plane at a high rate of speed and then it probably won't matter... ;-)

[Mtpisgah99]

I found a Gripen Jas-39 setup that should work well with Spektrum (6) channel receivers & AS3X. All the setups I previously tried, required reversing one canard (getting them in the same direction). I have smaller servo reversing modules but since Spektrum does Not recommend them with AS3X, I ended up just re-wiring one servo

setup for Elevons and pitch only for Canards:

1. First, I re soldered one Canard servo to get the Canards working in the same direction.
2. Then choose Dual Aileron setup/normal tale.
3. Next, plug one wing into the Aileron port and the other wing into Aux1 (flap), reverse one port to get the Ailerons working in the right directions.
4. Lastly, create one Elevator to left Aileron mix and use 100% in each direction (turn on trims), use a 3 way connector for the canards in the elevator port.

I have full trim in all directions, canards require initial manual centering. AS3X works for roll only on the Elevons and works for pitch only on the Canards. to me this seems like a decent compromise and I have some stabilization on all control surfaces. I will flight test tomorrow and see what happens?

My initial flight was using the same receiver with an Elevon setup (instead of dual aileron) and pitch only on the Canards via an elevator/flap mix (canards using the flap-aux1 port). AS3X worked in all directions for the Elevons but I had no AS3x on the Canards. The flight was successful but I had a bad case of the wing wobbles. I have my AS3X gain on a roller knob and had to drop the gains to 10% to stop the wobbles, effectively turning off AS3X. Although I have Not flight tested this latest setup, it appears to be better than the original Elevon setup. I have never setup AS3X on a delta wing and perhaps having AS3X combined with pitch and roll on Elevons, requires very low gains? If anyone else has tried the Dual Aileron setup or has any ideas, I would appreciate the input.

" 1. First, I re soldered one Canard servo to get the Canards working in the same direction." - how did you get to canard servo?

[kallend]

" 1. First, I re soldered one Canard servo to get the Canards working in the same direction." - how did you get to canard servo?

They are inside the main wheel wells. Rather awkward to access.

[kallend]

I’ve had stick on lead weights come unstuck before and that was on the inside of the plane, don’t think it would be much fun if it came off the outside so far back

If this refers to my "heavy nozzle", I think the entire rear fuselage will come off before the nozzle does.

[kallend]

I received my Gripen last Wednesday and it came in great condition. I assembled it Thursday and did the maiden on Saturday. It flew great with or without the canards activated. Canards activated definitely give her that extra turn and burn ability for sure though. She's a great flying bird with that classic menacing presence in the air that delta wings pull off so well. Thanks for making another winner Freewing and MotionRC!

Is that a stone wall right at the end of your runway?

(Looks like the runway could do with some TLC).

[sschenck75]

When removing the elevon servo from the wheel well,I tied a small string to the end. After soldering, I tied the servo plug to the string to pull it back thru the fuselage. I watched a YouTube video for “how to” solder/wire.. very simple.

[xviper]

" 1. First, I re soldered one Canard servo to get the Canards working in the same direction." - how did you get to canard servo?

Page 4 of the manual.

[Reborn8]

Is that a stone wall right at the end of your runway?

(Looks like the runway could do with some TLC).

True. The runway is a long 250ft but it does need some TLC but it is so wide people have plenty of room to land. We were supposed to get it resurfaced this year but Covid put the damper on that. There is a rock embankment that goes up at the end but like I said with a 250ft runway only a serious error would cause one to go into it. It has happened though 😊

[kallend]

I figure the pitot tube is very exposed, and based on past experience I expect it to succumb to hangar rash or grass damage before long.

So I made and posted a replacement against such time as this happens.

https://www.thingiverse.com/thing:4654706

(For some reason Thingiverse is rather slow bringing up pictures right now)

In response to requests, I also posted shortened versions that will be rather less prone to being broken off. Same URL

(May not show up for a while, Thingiverse is rather slow to update).

[kallend]

I've tested a few of these installed in a Mirage and Mig-21 and get ~2800-2850 grams at 25V, which drops from there.

Still +20% or so in thrust vs. the Freewing 1857kv fan for not a lot more amps.

Agree they're hard to beat for the price for 6 cells and really help heavier planes accelerate and climb better. I get about 200 ft. of extra vertical with the Mig and about +6-8 mph vs. the 1857kv FW fan. The Mirage is just a missile with this unit, although it's harder to get rearward CGs as it's also ~50 grams lighter than the older FW fan with the metal shroud.

Thrust measurement today. Stock Freewing edf unit, HRB 5000 mAh pack at 75 degrees F:

2.55kg thrust at 97 A peak current.

Rather disappointing. I have the FMS PRO on order from RCCastle. I expect around 2.8kg at much the same current based on my Mirage and Avanti with those units.

[kallend]

There is a rock embankment that goes up at the end but like I said with a 250ft runway only a serious error would cause one to go into it. It has happened though 😊

Murphy is always lurking.

[HaroldAnderson]

In response to requests, I also posted shortened versions that will be rather less prone to being broken off. Same URL

(May not show up for a while, Thingiverse is rather slow to update).

Thanks. Do you have one for the Mig-29? I rolled mine off the runway on the maiden and snapped it. I haven't gotten around to ordering one yet.

[HaroldAnderson]

Thrust measurement today. Stock Freewing edf unit, HRB 5000 mAh pack at 75 degrees F:

2.55kg thrust at 97 A peak current.

Rather disappointing. I have the FMS PRO on order from RCCastle. I expect around 2.8kg at much the same current based on my Mirage and Avanti with those units.

I wonder if anything can be done with the intake ducting or adding more cheater hole area underneath? I'm really enjoying high alpha flying with mine but more power climbing out would be nice especially when your are down really low and slow.

[Evan D]

I think you are at the mercy of your fan and motor. If you want to stay on 6S you'll have to get something more efficient or something more powerful (or both).

[Mizer67]

2550 grams is actually better than I was expecting from the 1920kv 9-blade kallend . I rarely got even 2400 grams once installed on the old 1857kv 12-blade FW fan at ~96 amps.

[RudyD54]

Hey everyone, this is the first plane I setup with elevons and I'm looking for some help getting my throws setup properly with my Spektrum radio. I've been breaking my head the last few days trying to figure out how to get the throws in the manual but all i do is end up confusing myself further.

I've got my wing type set to elevons and everything is moving in the right directions (including the canards, surprisingly those were easy), but I only get about 15mm up and down when i move the aileron or elevator to max deflection. Now, if i combine both full elevator, and full aileron, I get a max of about 23mm before the rod starts binding up against the bottom of the wing. Is that how this is supposed to work or should I be getting the full 23mm called for in the manual?

So far I've tried increasing the travel in the servo menu but that makes the binding i described before much worse. Any pointers or suggestions would be greatly appreciated!

-Rudy