Official Freewing Twin 70mm SR-71 Blackbird with Gyro EDF Jet Thread

[Evan D]

The gyro in the F-14 is in the control board so it's a little different than bypassing an external gyro like the 80mm F-22 PnP has. But still not hard.

[CAPTNG]

The question is, can the AR8360T replace the gyro and PNP receiver in the Freewing SR-71?

I just got a qualified "yes" from MRC. "Depends on your experience level and willingness to test and tune. At your own risk."

Now I need to figure out how to bypass the gyro -- weird wiring coming out (single wires of different colors for AER) but looks like regular leads going to the gyro. Where there's smoke....

[EDF-Jetpilot]

Question for techno-pilots: can this be flown with a Spektrum AR8060T that has SAFE/AS3X and bypass the Freewing gyro?

May I ask why you want to do that? Don't cause yourself any more problems and use the built-in gyro, that will definitely work better. Unless you're an SR-71 pro and can set the AS3X values very precisely on your first flight - otherwise good luck.
You can still use your receiver, you just have to leave the gyro values off, that's no problem and I do that with the B2, the F-14 and probably also with the SR-71.

Why keep it simple when you can do it complicated? Not me, I want to fly and not tinker. ;-)

[CAPTNG]

Why keep it simple when you can do it complicated? Not me, I want to fly and not tinker. ;-)

Good point. I will probably do the first couple of flights with the stock gyro then see about switching over. I like to fly with SAFE. Part of the hobby is tinkering.
I'm hoping to hear from others who switch to Spektrum AS3X receivers.

Also,part of the hobby is model detailing. Not much to do with this one. A lot of models come with black control horns and control-rod ends, so why, oh why did Freewing opt for white ones on the Blackbird? Detailing list: paint the control rod heads and servo horns flat black (carefully so as not to interfere with their operation); take a Sharpie (rather than paint) to the screw heads (it is surprising how much difference in ground appearance this makes); probably going to do this up as a NASA plane and get Callie Graphics instead of using the included water decals; maybe trade out the stock pilots for 1/17 scale (smaller) if I can find some.

[Evan D]

The SR has "SAFE" in the stock gyro.

[GliderGuy]

Removed

[CAPTNG]

Speaking of the included SR-71 GYRO, I'm a little unsure of how to plug the gyro leads into my receiver. The manual doesn't address the connections other than showing a schematic. The AER leads are all single wires split out from a standard 3-wire lead. I'm assuming that I plug these leads into the Signal ports of the corresponding control surface (top pin for Spektrum receivers) and the 3-wire Gyro Mode lead into the Flight Mode port. Yes?

[GliderGuy]

It does seem weird, but it works. The B-2 is the same.
Each of the single wires is a SIGNAL wire. So rotate/install every single wire connector onto the SIGNAL pin of your RX. In other words, all single wires will line up.

The color of the wire can be ignored.


-GG

[GliderGuy]

Can’t edit my prior post….#*!?**$&@

Hi Evan,
According to the documents, GREEN logo light is the basic flight mode (default). A BLUE logo light on the gyro = auto level mode.

Mine came defaulted to GREEN logo.

-GG

[Evan D]

If you don't plug in the gyro mode it does default to basic gyro (same as your B2). If you plug in the mode you can have auto level (SAFE) and off (again same as your B2).

[kallend]

May I ask why you want to do that? Don't cause yourself any more problems and use the built-in gyro, that will definitely work better.

How do you know this? My experience with Freewing gyros, both built-in and stand alone, has been uniformly negative. I won't use them any more.

[GliderGuy]

Comments anyone?
Unterminated inputs on the gyro and control board….

Until I purchase a new TX/RX, I’m not using the parachute, reverser, or Gyro Mode leads. Is it ok to leave the unused wire leads connected only at one end (open/unconnected at the other end), or should I pull them out of the plane?

My concerns are…these “might” pick up stray signals and conduct them into the inputs if left in the plane and only connected at one end.

EE folks out there…Thoughts? Am I being overly cautious? Best practices? Thanks.

-GG

[Evan D]

I always say plug in a surface (aileron, elevator or rudder) surface as airflow could move the surface and crash your plane. I don't think the chute would have this problem and since the gyro defaults to basic gyro I think that's okay as long as you are 100% sure it's doing things right. Not sure about the reverse, it may have to be plugged in for the ESC to arm. I think I have heard some had that problem. Easy to test.

[Aros]

All done except for the decals.

Post build impressions…drum roll please…and I am not affiliated with MRC LOL…here goes…

The quality of this PNP plane is excellent. I did not run into any snags getting her ready. The Admiral 6000 needed to be slid to the aft of the front battery bay to get the CG spot on (gear down). If one were to go with 2 batteries, some tail weight would be needed.

The range check was great. All quadrants. I have yet to taxi her, so I cannot comment on how well the nose gear is centered straight.

I added RF Chokes right at both ESCs on the lines that head back into the fuselage and an additional RF Choke between the UBEC and the RX. There is a green toroid ferrite choke already installed. I added another. RF Chokes are SOOO important to help prevent RF noise from the ESCs from disrupting your receiver.

A majority of the screws are Torx. I liked that! The inner main doors came default to “not scale”. They close after gear extension. I liked that that, too. It gets them out of harms way.

All the factory-installed screws were tight! The gyro was default “normal” (steady green light), and test “flying” in my hands proved that the gyro configuration is correct. There is an App you can download to configure the gyro, should you need to.

With the magnetic nose off, there is ample room in the bed of my Titan. Her right main fit into the tie down for the B-2…nice.

There is a seam line in the tail cone. I lined up the inner control surface with this seam. Then I lined the outer control’s trailing edge to the inner control’s trailing edge. I’m gonna start with about 3-5 mm of “trailing edge up”. Most of my birds require up elevator in cruise.

Rain for the next several days. Ugh.

Overall, I am VERY well pleased with the quality and design features. I’m ready to see how she holds up to her first 1,000 landings.

Next up…pilot flight reports as soon as the weather permits. Not going with any EXPO and will maiden on low rate. 6 ch gear, so no chute, no gyro settings changes, and no reverse thrust. I do plan to upgrade radios, so these other “neat’ features will be enabled soon. Timer is set for 3 minutes, and I will maiden at 50% throttle cruise. I anticipate 4-5 minutes at 50% throttle plus some full power acro (loops) and fast low passes…leaving 3.8V is my goal.

-GG

Nice! I look forward to your full maiden report!

[Evan D]

GG- "A majority of the screws are Torx".

Are you sure they aren't allen?

[CAPTNG]

GG- "A majority of the screws are Torx".

Are you sure they aren't allen?

They are 2mm hex

[GliderGuy]

LOL - My Torx driver fit. That’s what prompted my comment. I made one other mistake in my life. It was when I thought I was wrong, but it turned out that I wasn’t.


-GG

[CAPTNG]

For those of us who need readers for regular print, here's a PDF of 8x10 phone-photos (i.e., not great resolution, but readable) of the Freewing Guard Manual. Some translation need for Chinglish. Freewing Guard Manual.pdf

[Pete914]

So stoked on this jet. Will be buying when I save up some cash. What a beauty. Nice work MotionRC and Freewing. Keep them coming!

[Aros]

A buddy of mine is going to paint his in the M21 scheme. Great scheme and a nice way to help with any concerns of gatoring as well. I painted one of my LX versions years ago. Added bonus points for anyone who would add a 3D printed D-21 drone!