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Help! 4 TAIL SURFACE/SERVO EDF SR-71 DTFB?

PoorManRC

Well-known member
#21
My cheat. My dad was a senior photo interpreter for the U-2 and the Blackbird out of Henderson AFB, NV. That's a where I was hatched ya know! So Carmine, we be 2 of a kind, don'tcha know! Tail rudders that don't pivot in the slot? Never! I've got two old white PLA cutting boards (I think their PLA) that I use for plastic bearings. Works Fabulously! Even tapped a few tubes to mount on the end of a stick that slip into a outer tube as a no lube pivot point. Hmm... "It don't mean a thing if it ain't got that swing! Do-whop do-whop do-whop do-wow!"
That's cool... Have you ever worked at Beale or DET-1? I've got stories.... And pictures that I'm finally allowed to share! :p
I was just talking to Terry Pappas the other night, about the ground pounding Takeoffs. The BEST was the Orange Cones at Night!

Leaked?? No, she POURED!! She would lose almost 5000lbs. of Fuel, before her first "Stretch". She HAD to hit at least 1.5 Mach before meeting up with the Tanker, just to seal the seams!! At Operational Velocity, She was tight as a Drum.
 

PoorManRC

Well-known member
#22
Now the Black Beastie did have some... assist systems and hydraulics, (mostly useless from what I've heard, one system upgrade even caused a crash), but not much more. She... liked to fly, wanted to fly, but you had to stay on her every second. Even with the Auto-Pilot on. And no one can believe in the roll out shots on the ground, that vapor trail following her everywhere was leaking fuel! Cold on the ground she was a leaking black knife, to heavy to take off with full tanks. "Leak-y Teak-y!"
One of only 2 HABUs lost, was because of an early Avionics System installation! When Kelly Designed that Bird, she was Masterpiece Built as ANALOG.
Hydraulics were always there. No Mortal could move those flight surfaces at 35 Miles per SECOND!! And the Auto Pilot was merely a means to give the Pilot's arms a rest. She still needed Guidance, even with Auto Pilot.
She was NO 777!!! :eek:

..... I wasn't allowed to know much more than that. Even when I was in the USAF myself! I was only an E6 Though.
Gotta tell you.... as an Airman, when the guys found out who my Dad was - well let's just say that College Hazing was NOTHING compared to the ride I got!!! :oops:
Guess I was paying for my childhood. As a HABU Brat, me and the other kids from the 9th..... RULED the School!

EDF?? No less than 9 Blades, 12 preferably. This will never Sound right, or have the Thrust for the VERY Heavy Wing Loading with less.

For an extra "cool factor" try to find some strong, long projecting LEDs, around each Nacelle, that can be switched on after about 60% Throttle, to simulate Afterburners!! :cool:
 

kilroy07

Well-known member
#23
I understand at altitude they flew her with just trim alone... LOL

I've been thinking about the rudders... I don't think there is a way without getting into the exhaust tubes. REALLY open to ideas as I don't think the EDFs can react fast enough to use differential thrust.

For an extra "cool factor" try to find some strong, long projecting LEDs, around each Nacelle, that can be switched on after about 60% Throttle, to simulate Afterburners!
Already there brother, already there... Arduino will handle the mixing. red > orange > white....

I'm about a month away from cutting foam I think... I've started on the CAD plans... I have a few other things on my bench to finish up first.
 

PoorManRC

Well-known member
#24
I understand at altitude they flew her with just trim alone... LOL

I've been thinking about the rudders... I don't think there is a way without getting into the exhaust tubes. REALLY open to ideas as I don't think the EDFs can react fast enough to use differential thrust.
Except for between 0.9 and 1.3 Mach... Pretty much! :whistle: The Transonic range required FULL Sweep of the Surfaces....
BUT, at 80+, the "Atmosphere" was SO thin, they had to go back to full Sweep.

In "Spy Pilot" mode.... delicacy was absolute! Brian Shul made a .06% Course correction error - and got 400 miles off course in SECONDS. Found Himself being FIRED UPON...... By the ISRAELIS!!! :oops::eek:

The Rudders are certainly going to be an issue. The only thing that comes to mind is: a short Steel shaft coming through the Rudders, INTO the Engine Bays slightly. Attach small Servo Arms (like a Nose Gear), to more Shafts, meeting at a central Servo.....

For the Thrust Chambers... the ONLY thing I can think of is either a Venturi to clear the Rudder Gear (WOULD increase Thrust Velocity some).

OR, just leave the Shafts out in the Chambers, sealing the ingress/egress holes as best as you can.

Sorry Bro, that's all I've got.... Although in my defense, I haven't even built my FIRST Aircraft yet!! :LOL::p
It COULD work......
 

PoorManRC

Well-known member
#25
........... Here's one that I took, when I was 9! Dad, on Takeoff Roll, just ignited the first Burner!! :cool:
Except for one time, he and Lee Ransom always flew 979. They even called it THEIR Airplane!! Dad 979_05-72.jpg

I know.... It was 1972, and all I had was a 110 Camera. o_O
 

kilroy07

Well-known member
#26
I have toyed with the idea of a direct drive system, burying a servo in the lower part of the rudder that doesn't move (base?) but I would have to get some higher torque servos than the cheap Chinese ones I have now...

It's #3 on design challenges to solve. :LOL:

I remember 110s! Not a bad shot for those, you must have been on the taxiway. :love:
 
#27
To this day I know people who say Kelly Johnson was secretly meeting with... Aliens in the design of the Blackbird. She was just too... perfect for her role in life.
Venturi tubes, seal the by pass vents, wood dowel, base Teflon integrated plastic bearing, T-bar driven by two wires feed through tubes for better control, servo small light metal gear in the central wing to nacelle area. Pretty much the same for the everons.
Might check with MIT aerodynamics about adjustment of the engine cone. Even at lower speeds for the RC regulating on a push pull internal shaft might help with air flow. That and possibilities of using a sliding ring where some of the bypass vents could also assist. Ya never know until ya try?
 

kilroy07

Well-known member
#29
The cones are #2... :LOL:
I have thought about just two pieces of foamboard in an X to give the illusion of a cone (would have minimal effect on air intake) but the purest in me wants cones... I would NEED the bypass doors to use as cheater holes then I would think if I went that route.
(I REALLY don't think I'll need them to travel, but it would be cool.)

Maybe a vertical tie to the rudder with a control horn trailing in the tube with a central servo would be the best option. Be a pain to build, but it would keep the two rudders synchronized.
 

PoorManRC

Well-known member
#31
I have toyed with the idea of a direct drive system, burying a servo in the lower part of the rudder that doesn't move (base?) but I would have to get some higher torque servos than the cheap Chinese ones I have now...

It's #3 on design challenges to solve. :LOL:

I remember 110s! Not a bad shot for those, you must have been on the taxiway. :love:
How about Linear Servos?? And a Rod to each Rudder LE.
THIS is one aspect of the build that can be seriously over thought!!!!

Would a Micro Servo, direct driven, have enough Torque? :oops::unsure:

..... I used to REALLY suck up to John Fuller and Noel Widdifield - to get rides in the Chase Car!! :love::cool:
Sometimes a little jaded, being around that Bird all the time, I would get a HUGE thrill on Runway Inspection - barrelling down the Runway at over 120mph! ;)
 

PoorManRC

Well-known member
#32
The cones are #2... :LOL:
I have thought about just two pieces of foamboard in an X to give the illusion of a cone (would have minimal effect on air intake) but the purest in me wants cones... I would NEED the bypass doors to use as cheater holes then I would think if I went that route.
(I REALLY don't think I'll need them to travel, but it would be cool.)

Maybe a vertical tie to the rudder with a control horn trailing in the tube with a central servo would be the best option. Be a pain to build, but it would keep the two rudders synchronized.
You're going down THAT Rabbit Hole!!??? :eek: You know that those Cones were part of a 10ft. long assembly, that changed the Engine from a Turbojet to a Ramjet at Speed?

I'm also a purist when it comes to my Models. (Just watch how much massaging my Storch's LE's get!!)
But to get this Bird to operate as Kelly Designed it, may induce Insanity!!! :ROFLMAO::eek:

Dad-Kelly Johnson 73.jpg

Kelly Johnson really liked my Dad. Here he is, with my Dad.... at a spot that doesn't exist, working on the D-21! This Dude had a HUGE Brain!!!
....... @AkimboGlueGuns - you might appreciate this picture! ;)
 
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JTarmstr

Active member
#33
Kelly really knew how to build a airplane, he is also responsible for the P-38, arguably one of the best interceptors of WW2 (also held the american kill record with 40 kills in the pacific). he also build the U-2, F-104. The P-38 is one of my top 3 favorite airplanes along with the F-14 and the P-47. Also just for cool factor, maybe build a small parachute in the back for landing? It would look great at any flying field with a runway.
 

PoorManRC

Well-known member
#34
To this day I know people who say Kelly Johnson was secretly meeting with... Aliens in the design of the Blackbird. She was just too... perfect for her role in life.
Venturi tubes, seal the by pass vents, wood dowel, base Teflon integrated plastic bearing, T-bar driven by two wires feed through tubes for better control, servo small light metal gear in the central wing to nacelle area. Pretty much the same for the Eleveons.
Might check with MIT aerodynamics about adjustment of the engine cone. Even at lower speeds for the RC regulating on a push pull internal shaft might help with air flow. That and possibilities of using a sliding ring where some of the bypass vents could also assist. Ya never know until ya try?
....... NAW... Kelly was just a FREAKING GENIUS!!! The Pinnacle of her perfection - was using RUSSIAN Titanium to build Her!!

If Linear Servos have enough throw, they could be used for the Eleveons... The Central ones also tripled as Flaps. (Well, more like Spoilers. The far Aft positioning didn't make the most efficient Flaps)
 

PoorManRC

Well-known member
#35
Kelly really knew how to build a airplane, he is also responsible for the P-38, arguably one of the best interceptors of the war (also held the american kill record with 40 kills in the pacific). he also build the U-2, F-104. The P-38 is one of my top 3 favorite airplanes along with the F-14 and the P-47. Also just for cool factor, maybe build a small parachute in the back for landing? It would look great at any flying field with a runway.
Let's not forget about the P-80. He "threw that together" in Record Time, to be America's first operational Jet, after Bell's P-59 dud...
And his first Design, the Vega.

Many Men made Airplanes....... Kelly made HISTORY!