SR-72 DarkStar, 1:20 Scale, design by FoamyDM

FoamyDM

Building Fool-Flying Noob
Moderator
No, that was the battery life of two 64mm edfs sucking down 50a each on a 2200mah battery
2.2ah/100a*60min/hr = 1.32min not at full throttle all the time~1.5 to 2 minutes.

I think that might be the time it took to scale it down.
:LOL: It was quick, but not *THAT* quick. so, thanks!
 
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AIRFORGE

Make It Fly!
Moderator
No, that was the battery life of two 64mm edfs sucking down 50a each on a 2200mah battery
2.2ah/100a*60min/hr = 1.32min not at full throttle all the time~1.5 to 2 minutes.


:LOL: It was quick, but not *THAT* quick. so, thanks!
Daaannng! :eek:
 

FoamyDM

Building Fool-Flying Noob
Moderator
IMG_20220609_130321062.jpg

A quick lunch time update. I took an emery board to very gently sand down the tips of the prop so that they would spin freely in the somewhat flexible duct. Now to solder the electronics. Glue the nacelles down And install servos. Should be quick now.
 

Matthew Sanders

Elite member
Great job! It’s coming along! Very Nice! You’ve sure got a head start on me! I’m making one, too! But, unlike yours which is a legitimate replica of the SR-72, I’m designing the ACTUAL Darkstar from the movie. They look similar, but the designs are QUITE different.
6AB57217-B396-4D0F-A893-FA2E39CD57C2.jpeg

“Top Gun’s DarkStar”

Vs

8563C873-2E01-4723-B2D4-DB31175AC725.png

The Lockheed Martin SR-72
As you can see, the LM SR-72 has longer Scramjet intakes (does sr-72 have Scramjet or just “ramjet”?) Anyway the engine pods are longer. Single tail vs double tail, obviously, that’s already been talked about. Slightly different wing design, and the leading edge is different.
I’ll be powering mine on 2x 64mm EDFs running on 3300 4s 80c. I’m still in the design phase so I can’t give my specs just yet but I will have them soon.
 

FoamyDM

Building Fool-Flying Noob
Moderator
Either way, it will be beautiful. There are a number of 'sketches' of the SR-72, and the movie craft Darkstar. and they are an amalgum of bothe designs above. I saw the movie only once. and the ground beauty shots were over before I really... understood what was happeniing. However the lower (lockheed Martin) design seems to fit this picture, but the centerfold picture I started with clearly has 2 fins.
419127_8bbae7e8968672338156cfc425249e1d.png

i my design I did both. However, your TopGun picture does have a lot of great linework.
I used this picture to get my shapes: (and it looks legit)
1654864064549.png

... but then I see pictures like the ones below. This photo, and that opening hangar shot clearly show 2 vertical stabilizers
1654864273396.png

and then there is THIS REALLY convincing shots, where I see 2 Stabs, but a straight line leading to the wings that follow the nacelle.
1654864812678.png
From Flight Simulator: which has the blended planform with 2 Vert. Stabs.
1654864088347.png

so after this research, I learn... it doesn't matter much. the look is incredible. and that's enough for me.
@Matthew Sanders - Thank you for posting the great 2 and 3 views.

Related - this is where MSFS has the gear placed:
1654867374621.png
 

Matthew Sanders

Elite member
Either way, it will be beautiful. There are a number of 'sketches' of the SR-72, and the movie craft Darkstar. and they are an amalgum of bothe designs above. I saw the movie only once. and the ground beauty shots were over before I really... understood what was happeniing. However the lower (lockheed Martin) design seems to fit this picture, but the centerfold picture I started with clearly has 2 fins.
419127_8bbae7e8968672338156cfc425249e1d.png

i my design I did both. However, your TopGun picture does have a lot of great linework.
I used this picture to get my shapes: (and it looks legit)
View attachment 226831
... but then I see pictures like the ones below. This photo, and that opening hangar shot clearly show 2 vertical stabilizers
View attachment 226833
and then there is THIS REALLY convincing shots, where I see 2 Stabs, but a straight line leading to the wings that follow the nacelle.
View attachment 226834
From Flight Simulator: which has the blended planform with 2 Vert. Stabs.
View attachment 226832
so after this research, I learn... it doesn't matter much. the look is incredible. and that's enough for me.
@Matthew Sanders - Thank you for posting the great 2 and 3 views.

Related - this is where MSFS has the gear placed:
View attachment 226836
Your SR-72 does look more beautiful than the TG DarkStar. For sure the LM designers took a few inspirations from SR-72 in making the Darkstar (there’s no numerical designation in the film, like “X-00” or anything.) For my DarkStar, I’m going to do what FT does and make a Chuck glider and determine CG from that. Yeah, I dunno why in the official 3 view they showed the legit SR-72, because the matchbox toy company released some models from the film (F-18E, F-14A, P-51D, Su-57, and DarkStar.) So this is what the official die cast model looks like:
866EF040-F071-4890-B2AA-5505184D90F0.jpeg

For sure your SR-72 is more of a “scale model” and looks just amazing. Mine is kinda turning out to be an RC technology demonstrator. I definitely am concerned about CG, but your “wheel” post is definitely great advice that I will remember for future builds! Good luck on your maiden, whenever that is!
 

Matthew Sanders

Elite member
And just like that, I have my planform cut out. Before I go on, let me just say that by no means am I trying to subtract from @FoamyDM and the incredible work he’s doing on his GORGEOUS SR-72, but I thought this is the best thread to share my progress on my design of Darkstar. With a wingspan of 28.8” and a length of 48”, I’m actually surprised at how SMALL the model is compared to my expectations. But, since I built a test nacelle and used the nacelles as the “1:1 scale” value, I guess that shows how big they are in comparison to the actual airframe.
image.jpg
Planform with yardstick and one of 2 64mm EDFs that will power it for scale.
For those of you who are wondering, I plan to make the wings “airfoiled” with a legit FT style airfoil (instead of a KFm-2 like on my F-16XL.) Currently it’s just flat but I will make a airfoil plank and tape it to the front of the wing.
 
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FoamyDM

Building Fool-Flying Noob
Moderator
Your SR-72 does look more beautiful than the TG DarkStar. For sure the LM designers took a few inspirations from SR-72 in making the Darkstar (there’s no numerical designation in the film, like “X-00” or anything.) For my DarkStar, I’m going to do what FT does and make a Chuck glider and determine CG from that. Yeah, I dunno why in the official 3 view they showed the legit SR-72, because the matchbox toy company released some models from the film (F-18E, F-14A, P-51D, Su-57, and DarkStar.) So this is what the official die cast model looks like:
View attachment 226871
For sure your SR-72 is more of a “scale model” and looks just amazing. Mine is kinda turning out to be an RC technology demonstrator. I definitely am concerned about CG, but your “wheel” post is definitely great advice that I will remember for future builds! Good luck on your maiden, whenever that is!
Good post here Matthew, and thanks.
 

Bo123

Elite member
And just like that, I have my planform cut out. Before I go on, let me just say that by no means am I trying to subtract from @FoamyDM and the incredible work he’s doing on his GORGEOUS SR-72, but I thought this is the best thread to share my progress on my design of Darkstar. With a wingspan of 28.8” and a length of 48”, I’m actually surprised at how SMALL the model is compared to my expectations. But, since I built a test nacelle and used the nacelles as the “1:1 scale” value, I guess that shows how big they are in comparison to the actual airframe.
View attachment 226874
Planform with yardstick and one of 2 64mm EDFs that will power it for scale.
For those of you who are wondering, I plan to make the wings “airfoiled” with a legit FT style airfoil (instead of a KFm-2 like on my F-16XL.) Currently it’s just flat but I will make a airfoil plank and tape it to the front of the wing.
Just Watched the movie yesterday. Amazing movie, and the aviation scenes are amazing. I'm getting a FMS F-18 70mm and probs gonna do it up in a maverick skin.
 

FoamyDM

Building Fool-Flying Noob
Moderator
I realized thos would best to have a FC board. While rummaging around I found this:
1655034717195.png
This fits most of the bill. I have to look at iNav to see if it supports addressable leds like with betaflight

I printed wheel hubs, wheels printing now.
IMG_20220611_232621687.jpg IMG_20220611_233942221.jpg
Then I worked on the thrust tubes. I wrapping the with addressable leds. This is so I can connect the thrust color to the throttle if I can.
IMG_20220612_022035565.jpg IMG_20220612_023833016.jpg
Realizing the LEDs are bigger than the foambaord thickness, I will have to do something with the wing tip orientation lights.

Boy this is slow.
 

Matthew Sanders

Elite member
Just Watched the movie yesterday. Amazing movie, and the aviation scenes are amazing. I'm getting a FMS F-18 70mm and probs gonna do it up in a maverick skin.
Awesome! I have yet to maiden my E-Flite F-18D “Legacy Hornet” in the Blue Angels scheme. The FMS is a Super Hornet, accurate to the movie, but like the E-Flite, it’s also a 2 seater, so maybe you should put Goose in the backseat!
 

Matthew Sanders

Elite member
I realized thos would best to have a FC board. While rummaging around I found this:
View attachment 226928
This fits most of the bill. I have to look at iNav to see if it supports addressable leds like with betaflight

I printed wheel hubs, wheels printing now.
View attachment 226930 View attachment 226931
Then I worked on the thrust tubes. I wrapping the with addressable leds. This is so I can connect the thrust color to the throttle if I can.
View attachment 226932 View attachment 226933
Realizing the LEDs are bigger than the foambaord thickness, I will have to do something with the wing tip orientation lights.

Boy this is slow.
Oh, you have to do a board? You know, you can buy a 20 dollar aircraft nav light set off of Motion RC, it’s got 7 selectable settings, and it can plug directly into the receiver. The PDB comes in the kit.