Official Freewing JAS 39 Gripen 80mm EDF Jet

[HaroldAnderson]

I cut the hot glue off my receiver connectors and tried this. It seems to work fine. Anyone know of a reason that this will not work??
The Fr-Sky S8R has stabilization for two aileron and two elevator servos but this does not work in delta wing mode. I have a A3Super3 I was going to install in it for the canards but if this works it will be a little less nose weight!

Oops. I spoke too soon. The Y harnesses with canards cross wired did not work. I double checked everything again last night and the pitch control is reversed on the canards. Sorry, I didn't look closely enough yesterday...

[Skosh25]

Flying the Gripen and the Mig 29 back to back is quite a contrast. The Mig is like a big stately sedan and the Gripen akin to a Ferrari.

it took me a couple hard landings to realize I need really fly the Gripen onto the runway. It doesn’t float in like the MiG

[Evan D]

Frustrated over no TVs I put 50g in the tail and glued it on.


Motion should sell patience.

[Mizer67]

I'm relatively new canards and mixing. Getting ready for a maiden tomorrow and as I play with the gyros trying to stabilize the canards as well as elevons, the canards like to deflect down or up and stay there. Weirdest thing.

I ended up going with a separate gyro on the canards as it's the only way I've found to get stabilization to them.

I'm able to trim the canards with subtrim or offset in the mix itself, but it's a strange phenomena to me why they would deflect differently just changing from direct receiver input to input from the gyro then into the receiever.

[fredmdbud]

I'm able to trim the canards with subtrim or offset in the mix itself, but it's a strange phenomena to me why they would deflect differently just changing from direct receiver input to input from the gyro then into the receiever.

Are you changing modes in the gyro? For example, the receiver is feeding conventional ailerons and elevators, and the gyro is interpreting them into elevons.

[kallend]

Frustrated over no TVs I put 50g in the tail and glued it on.


Motion should sell patience.

Finally got around to maidening mine. Flew very nicely with 133mm CG. 5000mAh HRB pack with my "heavy nozzle" worked out well.

[xviper]

I'm relatively new canards and mixing. Getting ready for a maiden tomorrow and as I play with the gyros trying to stabilize the canards as well as elevons, the canards like to deflect down or up and stay there. Weirdest thing.

I ended up going with a separate gyro on the canards as it's the only way I've found to get stabilization to them.

I'm able to trim the canards with subtrim or offset in the mix itself, but it's a strange phenomena to me why they would deflect differently just changing from direct receiver input to input from the gyro then into the receiever.

That's really weird. As you can see in that video I posted up, using a single gyro RX, it all works. No mixing involved. Not that it matters but your view of the signal path is backwards. The signal goes from the RX to the gyro, then out to the servos in the case where you have separate units. In either case, the TX must be set to "normal wing/tail". It's the gyro that gets set to "elevon" or "delta".

[Evan D]

I have two to maiden tomorrow. Both 8s. One with AS3X and one without.

Finally got around to maidening mine. Flew very nicely with 133mm CG. 5000mAh HRB pack with my "heavy nozzle" worked out well.

[HaroldAnderson]

Finally got around to maidening mine. Flew very nicely with 133mm CG. 5000mAh HRB pack with my "heavy nozzle" worked out well.

I have mine printed and it really looks nice. The material removed was 15 grams and the heavy nozzle was 62 grams. Now I just need to figure out how much lead to add and glue it on.

[Mizer67]

That's really weird. As you can see in that video I posted up, using a single gyro RX, it all works. No mixing involved. Not that it matters but your view of the signal path is backwards. The signal goes from the RX to the gyro, then out to the servos in the case where you have separate units. In either case, the TX must be set to "normal wing/tail". It's the gyro that gets set to "elevon" or "delta".

Yes, I have the gyros set on delta/elevon, both for the elevons and the canards.

The radio is on "normal".

Still get weird stuff going on, but now that I've got it working, I'm just going to roll with it. All the directions of the stabilization is correct. All of the control surfaces working correctly. I just have to trim out with sub trim strange canard at-rest positions.

[xviper]

Yes, I have the gyros set on delta/elevon, both for the elevons and the canards.

The radio is on "normal".

Still get weird stuff going on, but now that I've got it working, I'm just going to roll with it. All the directions of the stabilization is correct. All of the control surfaces working correctly. I just have to trim out with sub trim strange canard at-rest positions.

What kind of gyro? If possible, use the rotary knob for master gain and start with very low gain. Or at least have the ability to turn both OFF at will.

[Husafreak]

I got my Gripen but its not getting unboxed till Christmas (don't ask) anyway plenty of time to produce a "heavy nozzle" but I know nothing about #D printing and don't have access to a printer. So if I copy the file on thingverse to a USB stick could I take it somewhere to be printed? Or can someone suggest the best and least expensive way to have one made? Thanks

[Husafreak]

Unrelated topic so... If anyone can compare this jet with full function (roll and pitch) canards versus pitch only that would be interesting. I was planning to do full function but there are a few folks here that did pitch only. I wondered why limit them?

[kallend]

Unrelated topic so... If anyone can compare this jet with full function (roll and pitch) canards versus pitch only that would be interesting. I was planning to do full function but there are a few folks here that did pitch only. I wondered why limit them?

1. Because that's how the real plane does it.

2. The canards are close to the centerline so any rolling moment they can produce is small compared with the elevons for the same amount of drag produced.

3. The downwash from the canards will cause an opposite rolling moment on the wing, again reducing their effectiveness for roll input.

4. Asymmetric wake shedding will mess with airflow over the main wing. One of the reasons for having canards in the first place is flow control.

[Robert Belluomini]

Aura 8 setup
FYI I posted this over in groups

https://www.rcgroups.com/forums/show...postcount=1276

You will also find the config file.
The canards act in pitch only and are stabilized along with the Elevons and nose gear steering.

Config file:

https://www.rcgroups.com/forums/showpost.php?p=45869433&postcount=1271

[radfordc]

Unrelated topic so... If anyone can compare this jet with full function (roll and pitch) canards versus pitch only that would be interesting. I was planning to do full function but there are a few folks here that did pitch only. I wondered why limit them?

If the elevons are set to max throw the plane rolls so fast that I can't keep up! I don't see how making it roll faster by use of the canards is a good thing....but that's just me. I reduced the elevon throws to 75% and it still does a full roll in half a second. Different horses for different courses.

[HaroldAnderson]

I got my Gripen but its not getting unboxed till Christmas (don't ask) anyway plenty of time to produce a "heavy nozzle" but I know nothing about #D printing and don't have access to a printer. So if I copy the file on thingverse to a USB stick could I take it somewhere to be printed? Or can someone suggest the best and least expensive way to have one made? Thanks

Check with the members in your club. Surely someone there local has a 3D printer. The guys that fly FPV or quads are very likely to be able to 3D print for you. It isn't a small print job though. It took my printer 13.5 hours but it is an awesome option. Fit and finish is great! I'm hoping I can reuse it with the VT option, when available. Thanks again Kallend.

My Kallend Heavy Nozzle ended up at 104 grams. Nozzle with 42 grams of lead shot added to balance my RT 5800s 35C (771 grams) at 10-15 MM behind factory CG. The plane also has an afterburner installed which helps a little.

[Evan D]

All planes are different for various reasons but mine took 50g (in the stock exhaust) to balance at 133mm with 8S that weigh 865g.

[Colorc]

Haha. I must be too used to the roll rate on the mirage cause with my control throw maxed out on the elevons, im still not feeling like the gripen is spinning that fast. Im not complaining though. I think its a nice balanced plan. Although, i would much rather have the gripen over the mirage if i had to choose. The gripen is just so much smoother than the mirage. I never felt like i was chasing after the plane like the mirage. Like it feels more locked in and not as "loose" as the mirage. High alpha was amazing and landing with about third throttle and pitching up was so stinkin predictable and smooth. Im flying at stock cg though. I was thinking of swapping my aluminum shroud edf from my avanti to get that back end a little heavier. Also, remove magnets and aluminum bits from the front nose.
The mirage deffinetly has it beat in balistic speed and power to weight ratio, but i feel like i can do everything else just as good or even better than the mirage.

[Colorc]

Unrelated topic so... If anyone can compare this jet with full function (roll and pitch) canards versus pitch only that would be interesting.

Having them handle roll and pitch, I noticed some yaw when trying to do a axial roll. I was able to use some differential to get better axial roll, but decided to go pitch only and not have to program any differential. Having it only in pitch also helped with the roll stability in high alphas and landing. The small adjustments to aileron in these situations seemed to make the nose drop and the plane to roll a little making it feel "loose." Other than that, i cant say it made a big enough positive difference for me to have it on roll and pitch. The rudder though. Wow! it has alot of authority in rolling the plane. Want to add a mix to tame it down a little.