#11
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I have a set on order now as well.
As for the additional details (conduit, etc): Based on Space X's own marketing of the kits I suspect their intent was to provide something which would present a moderate challenge to construct, in order to teach several skills to the modeler, and a semi-scale model of their Falcon 9 seemed like the most logical vector. They use the motto "Build rockets, build engineers" so it seems to me that these are meant to be a teaching tool and a form of marketing. That would seem to be the reason that much of the detail is just printed on. Their Falcon 9 with Fairing is a large-ish model rocket with plenty of payload space and decent available engines choices. What a perfect way to get kids into rocketry, experimentation, and build some good will with the more technical public. As it is, I couldn't live with the foam legs, the wooden ones were turning into a lot of work, and I really wanted to get this thing off the ground. If everything works out I might add some more scale details to mine but I'll be happy with the legsvand grid fins for the time being. |
#12
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The Falcon 9 model could be flown finless by utilizing M. Dean Black's finless model rocket stabilization techniques (they're covered in this issue [see: http://www.apogeerockets.com/educat...wsletter379.pdf ] of Apogee Components' "Peak of Flight" newsletter), which use the motor's exhaust and inward-ducted air to stabilize the rockets. His stabilization methods also make launch rods unnecessary (hand-held, tube-launched distress signal flare rockets also use this method of stabilization). Below are links to some examples: Here (see: http://www.cyber-heritage.co.uk/schermuly/mix1.jpg ) are several distress flare rockets (the unpainted metal cylinders) and their hand-held launching tubes, and here (see: http://www.cyber-heritage.co.uk/schermuly/pan2.jpg ) is another. In all of these flare rockets, the finless stabilization vents are readily visible at the rockets’ bottom ends. (Many of these flare rockets are 38 mm and 50 mm in diameter.) M. Dean Black’s finless scale model rockets use much smaller vents in order to preserve their scale appearance (the forward-mounted motor is part of such finless model rockets’ stabilization system). Plus: These and many more photographs of life-saving (flare and line-pulling) rockets—as well as information on them—can be seen here http://www.cyber-heritage.co.uk/schermuly/ on the “Schermuly and his Rockets” website. Also shown on this site is a 2-inch diameter, fin-stabilized illuminating flare rocket (see: http://www.cyber-heritage.co.uk/schermuly/ilu.jpg ) that could be modeled using Estes parts!
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Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see: http://www.lulu.com/content/paperba...an-form/8075185 http://www.lulu.com/product/cd/what...of-2%29/6122050 http://www.lulu.com/product/cd/what...of-2%29/6126511 All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com. NAR #54895 SR |
#13
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Just got an e-mail that my Space - X parts order is on the way!
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Dave, NAR # 21853 SR. |
#14
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__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see: http://www.lulu.com/content/paperba...an-form/8075185 http://www.lulu.com/product/cd/what...of-2%29/6122050 http://www.lulu.com/product/cd/what...of-2%29/6126511 All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com. NAR #54895 SR |
#15
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This was made when they were offering the much different Falcon 9 with Dragon kit, but I think Space X's promotional video shows their line of thinking.
Space X Promotional Video |
#16
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__________________
Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see: http://www.lulu.com/content/paperba...an-form/8075185 http://www.lulu.com/product/cd/what...of-2%29/6122050 http://www.lulu.com/product/cd/what...of-2%29/6126511 All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com. NAR #54895 SR |
#17
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I already have an Aggressor Aerospace kit called the KZ-1 that uses grid fins for stabilization. This is a scale model of a Chinese SLV If you want one, I'll sell it to you wholesale. |
#18
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I just read your description of the KZ-1 model's stability in Posting #1 here: http://forums.rocketshoppe.com/showthread.php?t=15323 , and I am intrigued. The fact that its grid fins work *at all* at that small size--especially considering how "rectangular bar-like" each "flat plate strip airfoil" is, as is apparent in a photo here (see: https://www.apogeerockets.com/Rocke...Rocket-Kits/KZ1 )--bodes well for the usefulness of grid fins on scale model rockets! (I'm not being critical of the KZ-1 kit--its grid fins' narrow-chord "flat plate strip airfoils" are hard to make to scale thickness at that size.) If the grid fins' "strip airfoils" could be made closer to their scale thickness, the turbulence that reduces the fins' effectiveness could be reduced. Maybe such a grid fin "master part" could be made, then be used to create cast polyurethane resin duplicates. If necessary for strength, fine chopped fibers could be mixed in with the resin before it was poured into the molds.
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Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see: http://www.lulu.com/content/paperba...an-form/8075185 http://www.lulu.com/product/cd/what...of-2%29/6122050 http://www.lulu.com/product/cd/what...of-2%29/6126511 All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com. NAR #54895 SR |
#19
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I suspect the grid fins on that KZ-1 are acting more to create drag than in any other aerodymic way. They likely work in the same way that the skirts on many "finless" designs do, just moving the CP to the rear away from the CG. I could probably sort out some perfect-world physics for any effect they are having but I think the reality is that they are slightly more efficient versions of the same overall shape with solid surfaces. I wonder, given other aerodynamic considerations, how much air is actually moving through the grids of the scale model at flight speeds.
Hmmmmm... |
#20
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If the same model was fitted with scale-proportioned grid fins (whose "strip airfoils" were truly thin strips parallel to the airflow), and if it exhibited a lower level of stability (taking longer to respond--with less restoring force--to perturbing forces) than it has with its current grid fins, that would suggest that the narrow "flat plate strip airfoils" produce ineffective lift (because of the Reynolds Numbers at which such tiny airfoils operate, at the model's airspeeds). Another possible cause for such behavior, if such was observed, could be "choking" of the airflow that 'tried' to pass through the grid fins' airfoils, because they were so closely-spaced. (I think this would be a less likely cause, if such behavior occurred.) Determining the characteristics and capabilities of grid fins on model rockets would be an interesting NARAM R&D project...
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Black Shire--Draft horse in human form, model rocketeer, occasional mystic, and writer, see: http://www.lulu.com/content/paperba...an-form/8075185 http://www.lulu.com/product/cd/what...of-2%29/6122050 http://www.lulu.com/product/cd/what...of-2%29/6126511 All of my book proceeds go to the Northcote Heavy Horse Centre www.northcotehorses.com. NAR #54895 SR |
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