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SpaceX Falcon 9 QTV in 1/70 scale
This is my first new design this year (IIRC), and might even be my first in over six months! I've been 'recharging my batteries', and it's been a slow trickle charge fer sure...
First item: RockSim is throwing up a NAN on this design, for reasons I can't locate. It may be my installation of RS acting funny, so if someone could run a few sims with the file, I'd like to hear. Second item: This is not true-scale, in that the lines of the Dragon QTV are totally wrong, and the lengths of the tubes are wrong. However, the length of the model is 1/70th the stated length of 178' for the prototype, and the diameter of 2.04" (ST-20) is only 0.01" smaller than the prototype diameter of 12'. If I can locate the correct shape of the QTV spacecraft and other dimensions, I'll correct this design. In any event, this should be an impressive bird in flight. Specs: Length: 30.51" Diameter: 2.04" (ST-20) Weight: 3.71 oz Fin Span: 4.04" Use a 3/16" launch rod. Since the simulations were NAN, I don't know about guide lengths or deployment velocities yet. See what you can get it to do!
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Craig McGraw BARCLONE Rocketry -- http://barclone.rocketshoppe.com BARCLONE Blogsite -- http://barclone.wordpress.com BARCLONE Forum -- BARCLONE Forum BARs helping BARs SAM 0044 AMA 352635 |
#2
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Craig pitches, Jay swings...
Quote:
From the revised file: v.2 minor tweaks by Jay Goemmer 1) Changed "static margin reference" to Maximum Frontal Diameter. 2) Added 2 SE-14 screw eyes at base of nose cone. 3) Moved parachute 1.5" forward. Stability margin is still only 1.31 calibers on a 24mm "C" motor. First two sims are with "Max Diameter," the second two with 1 more SE-14 in the nose cone, and the last two with two SE-14's. That's about all I can do just now. (shrug) Cheers,
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Jay Goemmer "Centuri Guy"/"Tau Zero" YORF Member 28 Semroc SAM #0029 NAR 86131 "I think about organizing things all the time. Never seems to happen. I find something that piques my interest and I'm off on a quest. Or a Centuri. " --Bill Eichelberger, 02/22/2022 “Centuri fret buzz in an updated form.” Bill “Wallyum” Eichelberger re: Estes Flutter-By 03 Sept 2014 |
#3
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Craig goes deep center...
Thanks, Jay!
It was Max Frontal's problem... He went Full Monty... The length of the rocket was wrong, but I located another reference from Spaceflight Now with a length of 154' for the QTV flight. This drops the length down to 26.4". I was able to get a simulation after changing the margin reference point, and loaded up a D12-5. Next, I tweaked the fin shape and size until I got a margin of 1.39. Did I say this would be impressive in flight? See the specs below... Length: 26.4" Diameter: 2.04" (ST-20) Weight: 3.65 oz Fin Span: 5.54" D12-5......912'......Dv 18 FPS......33" guide length (use a 48" x 3/16" rod) Now try it out! Enjoy!
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Craig McGraw BARCLONE Rocketry -- http://barclone.rocketshoppe.com BARCLONE Blogsite -- http://barclone.wordpress.com BARCLONE Forum -- BARCLONE Forum BARs helping BARs SAM 0044 AMA 352635 |
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Sideline thought...
I wonder how close the Dragon QTV capsule comes to the SEMROC Orion nose cone? These two designs - minus the Orion's pods - are mighty close in size...
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Craig McGraw BARCLONE Rocketry -- http://barclone.rocketshoppe.com BARCLONE Blogsite -- http://barclone.wordpress.com BARCLONE Forum -- BARCLONE Forum BARs helping BARs SAM 0044 AMA 352635 |
#5
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Outta the park!
I just ran some additional sims using the E9-6, and the performance was astounding.
Altitude 1469', with 6 out of 8 sims giving a Dv of 5 FPS (all sims less than 12 FPS!), on a guide length of 43". Margin is 1.04, so it's still technically stable for flight. This will improve as the engine burns off some mass...
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Craig McGraw BARCLONE Rocketry -- http://barclone.rocketshoppe.com BARCLONE Blogsite -- http://barclone.wordpress.com BARCLONE Forum -- BARCLONE Forum BARs helping BARs SAM 0044 AMA 352635 |
#6
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Craig, this looks GREAT! I want to build it!
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