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Thread: RC Blackbird SR71. Is this cool or ICE COOL!?

  1. #16
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  2. #17
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    Don't laugh too hard - there's some serious science at work there.
    The SR 71 for example. My guess would be about $45,000 construction cost. The turbines would be about $8,000 each, fully computerised with automatic start sequence,compressor pressure and exhaust gas temperature sensing, oil injected ceramic mainshaft bearings and a maximum mainshaft speed of about 180,000 rpm.
    In terms of engineering, they are decades ahead of anything that ever came out of Milwaukee.
    The capabilities of modern radio control gear are a whole different chapter, as are the construction techniques and materials used in the model itself.
    Sure, they are still toys, but in a sense, so are F1 cars.
    I may not be as good as I once was, but I'm as good once as I always was.

  3. #18
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    The next gen of RC "toys" will be gliding/cruising over the surface or Mars in the near future! I always love the ingenuity of the creators and the passion that goes into them.

    And the pain that occurs when failure pronounces a terminal impact with earth!
    "I like to ride anyplace, anywhere, any time, any way!"

  4. #19
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    Quote Originally Posted by Bass View Post
    Don't laugh too hard - there's some serious science at work there.
    The SR 71 for example. My guess would be about $45,000 construction cost. The turbines would be about $8,000 each, fully computerised with automatic start sequence,compressor pressure and exhaust gas temperature sensing, oil injected ceramic mainshaft bearings and a maximum mainshaft speed of about 180,000 rpm.
    In terms of engineering, they are decades ahead of anything that ever came out of Milwaukee.
    The capabilities of modern radio control gear are a whole different chapter, as are the construction techniques and materials used in the model itself.
    Sure, they are still toys, but in a sense, so are F1 cars.
    I got the impression that the SR71 in the video may have just been single turbine in the centre (of course would have had to have intake to match), but was just paying attention to the guy starting the thing.

    I could be completely wrong though...

  5. #20
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    Quote Originally Posted by Devil View Post
    I could be completely wrong though...
    Having had a good look at a turbine powered RC jet first hand, and looking at the size of the SR71 model, I'd have to say it's running two - that's a fairly substantial aircraft to be powered by only one model turbine (they aren't THAT powerful).

    If you look on Youtube there is an RC Grumman Tigercat which is running two 400cc 5cyl Radial engines - that's gonna sound awesome when it's flying!
    KiwiBitcher
    where opinion holds more weight than fact.

    It's better to not pass and know that you could have than to pass and find out that you can't. Wait for the straight.

  6. #21
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    cool
    Wonder if they could strap ya on and go a Weee fly lol
    Steel and Bullets
    <! !>

  7. #22
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    Quote Originally Posted by Devil View Post
    I got the impression that the SR71 in the video may have just been single turbine in the centre (of course would have had to have intake to match), but was just paying attention to the guy starting the thing.

    I could be completely wrong though...
    He had an inspection hatch open in the middle of the fuselage for sure, but that means nothing nowadays. He may have been checking clean fuel flows from a central tank. Air bubbles can get an instant motor stop. An engine start on a turbine is just the flick of a switch on the transmitter.
    I may not be as good as I once was, but I'm as good once as I always was.

  8. #23
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    Quote Originally Posted by R6_kid View Post
    that's a fairly substantial aircraft to be powered by only one model turbine (they aren't THAT powerful).
    As I recall, the largest commercially available model turbine puts out about 18 kg of thrust which would be enough to fly that model more than adequately. However, the clip demonstated a pretty good vertical performance and so I tend to think that you are right and that he is running 2 turbines.
    Incidentally, there is a microlite ( the Cri Cri as I recall) available that's powered by a couple of those turbines. I have often wondered why, because while they are effective enough, their compression ratio is quite low (about 2.8 to 1) which means that they are pretty inefficient and really drink the fuel. The result is an eflux velocity of a bit under mach 1 where a full size turbine efluxes at typically a bit over mach 2
    I may not be as good as I once was, but I'm as good once as I always was.

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