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

[Evan D]

Look at the one on the 70mm Panther main struts.

Update…JB Weld wouldn’t hold. Cleaned it all up and am trying Foam-Tac. It will withstand fracturing better than epoxy. Basically, a sheet of carbon is being glued to the top and bottom flat faces of the anti-torsion arm which “cover” the area of the fractured plastic expansion fork/anti-torsion arm.

Whatever you might engineer, a suggestion is make your anti-torsion arm stronger BEFORE it breaks. It is a spare part on MRC, but this part isn’t shipping, yet.

-GG

[EDF-Jetpilot]

Anyone know if the EG01 can be used for steering as well? Just Y into the RUD maybe? I usually install the Assan AG61 in all my EDFs but I don't have an extra for this one and could not find anything in the manual.

I'm not a fan of steering gyros on the nose wheel, but the B2 is almost impossible to control on the ground in crosswinds without one. But since the SR-71 is much longer than an F-16, I don't think it's needed here. My EDF jets don't usually fly completely straight on the ground, but you can easily correct that during takeoff. I love gyros in the air, but I don't need them on the ground, except for the B2. The longer the wheelbase, the less a nose wheel gyro is needed and vice versa. That's simple physics in my eyes. But to each his own, as far as I'm concerned you can mount a nose wheel gyro on the SR-71 too, I think that's a bit excessive.

[GliderGuy]

Update…JB Weld wouldn’t hold. Cleaned it all up and am trying Foam-Tac. It will withstand fracturing better than epoxy. Basically, a sheet of carbon is being glued to the top and bottom flat faces of the anti-torsion arm which “cover” the area of the fractured plastic expansion fork/anti-torsion arm.

Whatever you might engineer, a suggestion is make your anti-torsion arm stronger BEFORE it breaks. It is a spare part on MRC, but this part isn’t shipping, yet.

-GG

[GliderGuy]

Temporary fix. I will sand it smooth once the Foam-Tac cures.

Basically, I built a carbon fiber box around the weak nose gear expansion fork/anti-torsion arm.

Suggest you reinforce yours before it breaks. Easier now than after it breaks.

-GG

[GliderGuy]

Hi Aros, Time to put the FW re-design team to work.
After 21 flights, GG has uncovered the first design weakness.

The plastic expansion fork/anti-torsion arm on the nose gear is too weak. It MUST be made stronger! The arm snapped. Of course, no steering after that, and when I lifted the bird, the wheels+shaft fell out.

This is going to require some thought as to how to fix it and get the bird going again before spare parts become available.

I’ll start to engineer a solution this evening. Stay tuned. I’m gonna look at a carbon fiber solution.

I have faith your team will come up with a more robust solution. If it must be plastic, then make it a solid piece without any mold cut-outs. The thin molded cut-out area is where it snapped.

So far, other than this, the bird is a solid, robust design. Reinforce yours BEFORE it breaks!
The black line shows where it broke.

-GG

[Aros]

At least on calm days…maybe this is the way to land her short. Impressive! Need to experiment up high first.
No claim to the video’s authenticity is made. Attempt only if you decide it’s safe.

https://m.youtube.com/watch?v=s9pQ6LIorV8

-GG

I believe that video shows Jon (Two Brothers RC) at his well aft of recommended CG flights, not totally sure, plus of course it's slow motion obviously. For me personally I am sticking to recommended CG, at least for my initial flights.

[Aros]

There is a spare parts listing for it, so I hope so.. Just need to wait for stock now.

Yeah I forgot I added that spare part, lol! Total brain fart. The latest estimates are early March but they are verifying exact ETA.

[GliderGuy]

At least on calm days…maybe this is the way to land her short. Impressive! Need to experiment up high first.
No claim to the video’s authenticity is made. Attempt only if you decide it’s safe. So far, I haven’t come close to doing this. I’ve been landing like the AL-37…about 4 clicks of throttle on final until round-out.

https://m.youtube.com/watch?v=s9pQ6LIorV8

-GG

[F106DeltaDart]

Sorry to see that F106DeltaDart. I don't know if we plan to carry the canopies as their own spare parts to be honest. If enough customers are wanting to switch out pilots maybe it's something they will consider?

There is a spare parts listing for it, so I hope so.. Just need to wait for stock now.

[Aros]

Sorry to see that F106DeltaDart. I don't know if we plan to carry the canopies as their own spare parts to be honest. If enough customers are wanting to switch out pilots maybe it's something they will consider?

[F106DeltaDart]

Word of warning to anyone who wants to replace the pilot figures… Tried to take off the canopies yesterday. The rear canopy came off with a bit of work just as you would expect. The front canopy, however, cracked almost immediately right down the center. It appears to be made of a thicker and stiffer plastic that makes it more brittle. And of course, there aren’t any parts in stock yet. Guess I’ll be waiting for the spares to come in..

[Skosh25]

Hi Skosh25…I know lots of folks love to use steering gyros, but in my experience…kinda overkill for the SR-71. She tracks very straight.

Anybody else have a comment on the bird’s ground behavior?

-GG

.

That hasn’t been my experience so far GG. Have had to manually adjust the steering linkage after every flight.

[GliderGuy]

Here’s a good color match for the SR-71…

spray can

TAMIYA COLOR TS-29 SEMI GLOSS BLACK

-GG

[GliderGuy]

Anyone know if the EG01 can be used for steering as well? Just Y into the RUD maybe? I usually install the Assan AG61 in all my EDFs but I don't have an extra for this one and could not find anything in the manual.

Hi Skosh25…I know lots of folks love to use steering gyros, but in my experience…kinda overkill for the SR-71. She tracks very straight even after some not-so-good landings while learning her. No steering linkage adjustments needed, so far.

Anybody else have a comment on the bird’s ground behavior?

-GG

[GliderGuy]

Finally got around to checking the post flight cell voltage. The 10 flights yesterday were all made on brand new (first flights on them) Admiral 6000 mAh batteries.

1) Timer = 3:00
2) Gear down and upwind entry started at 1:30 remaining
3) Post touchdown timer showing about 20 sec (so a 2:40 flight)
4) Mix of throttle from 100% take-off to 50% to 75% cruise…no 100% used after the initial take-off.

Most cells measured 3.9V.

So, I’m gonna change my timer to 3:30 and adjust my pattern entry time based on throttle management for any given flight. For an almost total 50% throttle flight after take-off, getting to 4:00 might just be possible.

Also, the stock EC5 connector did not get warm or hot. I still plan to change it to a split barrel type ASAP.

-GG

[Skosh25]

Anyone know if the EG01 can be used for steering as well? Just Y into the RUD maybe? I usually install the Assan AG61 in all my EDFs but I don't have an extra for this one and could not find anything in the manual.

[EDF-Jetpilot]

For me, it’s more that I already had an extra AS3X receiver on the shelf. I had nothing against the stock gyro, but I would have had go buy another receiver to use it.

You wouldn't have had to buy another receiver, you can switch the AS3X on or off as you like on any receiver using forward programming in the transmitter. You can also use any Spektrum receiver with AS3X and Safe as a normal receiver.

[DCORSAIR]

I totally agree! I made 6 more in dead calm. Without the chute or reverse, best have some pavement to roll out on.

Total flights = 17

-GG

I have 12 flights as of now on mine. I have plenty of runway myself to let it roll out and a couple of times I didn't pop the chute just because I got tired of repacking it

[Aros]

Made 4 more flights this morning.
STOCK gyro does fine. New “discoveries”:

1) 5-7 mph direct cross wind = she did well
2) Gotta REALLY keep in your head what you are doing. I was yacking to a bystander and turned downwind. I lost orientation due to the distraction. Only experience saved it. IF YOUR ARE DOING SOMETIHING TO CORRECT THE SIGHT PICTURE AND THINGS GET WORSE….DO THE OPPOSITE FAST!

Doing the opposite fixed my sight picture as the plane leveled out. A novice would have plowed her into the ground. It happened so fast.

Don’t let yourself get distracted. This bird demands focus. Even to the point of talking to yourself like,”Going right, so left will shallow!”

3) She flies well at 1/2 throttle. Will allow for a bit more extended flights.

Loving this bird!

-GG

Oh yes, this bird DEMANDS FULL ATTENTION AT ALL TIMES. As DCORSAIR mentioned, I always talk to myself when flying a SR-71 as I refuse to paint any orientation-non-scale colors on it. "Banking left....Banking right..." etc...Keep those tails pointing up at all times (except when performing an aerobatic maneuver). Distraction is death with this model. Ask me how I know! LOL!

[Aros]

Hi,

I want to mask and paint mine to the M21 or A12 silver/black scheme, but I have never had much luck peeling masking tape off of FW planes without the existing paint peeling up. Those of you who've painted these, what kind of masking did you use? Any tips?

I always use painter's tape. Either the blue or green variants. One key is to stick the piece of tape on your pants or something a few times to help absorb some "tack" of the tape. This way, when you then put the tape down, it's less likely to pull up the stock paint when it's time to pull up the tape. I've had good success with this method over the years. However, I ALWAYS plan ahead and have matching paint to do touchups which are almost always inevitable no matter what you do. You can get a small tester's-size from Home Depot or Lowe's if you bring a piece of the plane in for them to scan the color. Works great! For something like this model you can just grab a rattle can or small paint sample (say, Testors 1/4 ounce enamel for example) of black paint with eggshell finish and be good to go to cover up any dings, blemishes or paint pull ups.