SR-71 for EDF 50 (Closer than we might think) - RC Groups
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Dec 30, 2001, 09:41 PM
Electric Coolhunter
Thomas B's Avatar

SR-71 for EDF 50 (Closer than we might think)

While out in the garage sanding along on my WB-57F a flash of creativity impaled me.

I happen to have a very few sets of unassembled HobbyLab Sr-71 foam shells from my HobbyLab days of creating rocket boosted gliders. A few moments work trimming with an exacto knife enable me to lay out this little scene, complete with EDF 50 units....<evil grin>

Will HAVE to try this. But, here is the bad news. These shells are no longer available. I think the tooling is over in China somewhere, probably rusting away. Plus, it had a rather poor and flat airfoil, designed to boost straight up first and glide well second. Also,the nacelles will not quite close around the fan units, but there are other ways to deal with that little problem. If nothing else, I will do the Chris Gold trick of letting the units hang out the bottom and fly this thing as a single surface SR-71 for fun...

PLEASE NOTE that this will not be a kit ever in this exact form, and that it is not a Don and Jerry creation..., but it surely is a quick way to see how workable the idea might be.
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Dec 31, 2001, 12:38 PM
Registered User
yes i would think that if designed with the right airfoil it would make a VERY good flyer! with the lifting body, delta wing (low wing loading) and the power of 2 fans it would and could possibly be a little hot rod
Dec 31, 2001, 03:35 PM
Flying...Pushing Air Down
sr71fan's Avatar

Blackbird EDF

Mine flies really good; too big, though.

I took this photo in England, in 1984.

Last edited by sr71fan; Dec 18, 2003 at 02:53 AM.
Jan 02, 2002, 01:56 PM
Crashez-vous sans stress!
Dan H.'s Avatar

Re: Blackbird EDF

Originally posted by sr71fan
Mine flies really good; too big, though.
Me too; I sold mine when I got tired of paying $20,000 for an hour's worth of JP-7 every time I went to the flying field.

Also kind of annoying that it was too hot to go near for a half hour after landing.
Jan 02, 2002, 02:14 PM
Dude, where's My Plane?
JasonJ's Avatar
I am going to try and bash one up out of Depron for twin MF 480 66mm, this airframe with its oversized motors beggs for scale EDF and the foam should make the compound curves easy compared to balsa.
I gave my full scale one to nasa cause it leaked like a harley in my drive way and the JP 7 kept eating up the pavement, I liked the hot titanium thing, no one would try to steal it when I parked it at the mall .
Jan 03, 2002, 04:45 AM
Houng-wen Lin
GWS4CEO's Avatar
Looks like a great choice to fit 2 pcs EDF50 into SR71.

May be GWS should make a SR-71?
Jan 03, 2002, 05:25 AM
Flying...Pushing Air Down
sr71fan's Avatar



I'll do a free-of-charge series of test flights on it for you!

Send it to ... e-mail me for my address.

Last edited by sr71fan; Dec 18, 2003 at 02:56 AM.
Apr 05, 2002, 08:27 PM
Registered User
I stumbled on this old thread while searching for something else, and thought I'd chip in my $.02. I have one of the RC versions of this Hobbylab plane. In my sometimes other life, I also dabble in rocketry (does 4,867 rockets count as dabbling? ) But seriously, I have considered, however briefly, converting mine to electric RC - after I fix the nose. Mine flew great with the stock setup, but on its third flight, the hot melt glue holding in one of the servos gave way during boost, and its last few hundred feet on the way up was a wild corkscrew. I fought the plane all the way down, and was able to flatten out the descent enough to minimize the damage. That being said, I think the Hobbylab SR71 may be too heavy for the GWS fans. I'd be happy if someone proved me wrong, though. I opened mine up and gutted out all of the **heavy** radio gear and control bits that were installed. I'd been thinking of reassembling it with micro equipment to see how that affected the boost and glide, but since I have a couple of other boost gliders in various stages of construction, I'm just going to let the idea simmer for a while, until I clear out a few projects.

Tony Turley
Apr 05, 2002, 10:38 PM
jah's Avatar
Tony, how about two Vasa55s. With Speed280bb and 8X500ARs my fan puts out 8 oz's of thrust. Only a few mm bigger than the GWS units, but the fan, motor, and battery weigh 8 1/8oz

I would get right on it but I have the following kits on the shelf:
GWS Zero w retracts
X31 for the EDF50
S3 for EDF50's
Wattage SU-31
scratch built SU25 for ??? (tried EDF50, next attempt twin KP44's)
NCC1701-D for ??? (tried EDF50, next attempt twin GWS IPS DD)
two herr kits
one guillows kit
100 pounds of blue, pink, and white foam (yeah pounds!!!)
8 walmart gliders
cox P51
cox F22
4 American Airlines gliders!!

Now if I only had all the servo's, ESC's, RX's, and motors for all these planes I would be set!

Fellow Bald One
Apr 06, 2002, 10:09 AM
Speed Demon
GregG's Avatar
Great looking plane, I've always loved it. I've got one of these kits NIB that I had planned on R/Cing. Where is the CG for the R/C version? There where no instructions in the box when I got mine.

BTW, The box is one nice carrying case.
Apr 06, 2002, 11:00 AM
Registered User
I don't remember off the top of my head where the CG is located. Mine came ARF with the radio installed and the body sealed; all I had to do was glue on the fins, add batteries, the motor, and fly.

Tony Turley
Apr 19, 2002, 10:08 PM
Registered User

watch your air foil

i have been working on one,kevlar,carbon fiber.i had to slightly hange the air foil.mine is 110"
long and 56" wide.2000" lifting serface,for edf.early proto-type was to unstable,needed to deepen the bottom center line,from the wings to the needel
Apr 23, 2002, 11:01 PM
Registered User
I've been designing a SR71 for about a month now. The first ones going to be made of blue fanfold foam and balsa. It's gonna be almost scale, you'd have to measure it to tell though as there's almost no visual difference. The SR71 kinda makes for a neat project due to it's lifting body. All up weight it gonna be around 16-18 ounces powered by two edf 300's. Not sure about batteries yet as I'm gonna have to just test and see. The real trick for me right now is balancing work, designing, and building. The weather around here has been nice and I keep going out to do some free flight stuff. Maybe soon I'll get some computer stuff and post up some design and construction pics of it.
Apr 24, 2002, 10:44 AM
Real Men Fly Pink Planes...
kepople's Avatar
I am not suggesting breaking any copyright laws, but boy it would sure be nice if someone that owned one of these Rockets would make a mold of the fuse that could be cast in foam, or glass. Boy would that be nice, not breaking any copyright laws or anything, but then that person could loan out a couple of his copies to test this rc possiblity. He could not sell them, but he could loan them out, while maybe recieving something on loan from the person who he loan his fuselage to.

Boy that would be something. I think a little Blue foam strategically placed in the wing would give the airfoil shape we need.

Apr 24, 2002, 11:38 AM
Dude, where's My Plane?
JasonJ's Avatar
Huh, I was just in a little hobby shop I had not been in in years,,, no flight stuff,,, except some old rockets. He had a few SR-71 rockets,,, They did not look like foam though. $18 .
HopFlyr,,, your project sounds cool, I have been kicking the same idea around but for 480 fans but since I trashed one of my rotors,,,, I have one vasa 55 with speed 300 and I think I will get another, the fuse looks like a piece of cake out of blue foam, 8 Radio shack 1600Mah NiMh cells good for about 20 A, or 8 CP 1300s.
My bigest issue is where do you put the C of G on that thing ????
I am very interested in seeing what you have on this project,,, I have yet to see a good SR-71 EDF,,, and the subject always seems to draw intrest.

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