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  #1  
Old 01-12-2019, 09:09 PM
Tau Zero's Avatar
Tau Zero Tau Zero is online now
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Join Date: Mar 2005
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Exclamation Centuri Semroc RockSim nose cones

Back in October 2007, I wrote the following elsewhere on this forum (under "Multi-Part Nose Cones"):

"Here are some basic files on creating nose cones in RockSim from more than one part. Usually, that entails using a nose cone (*sometimes*) and building the rest of the shape up from one or more transitions.

I picked the Semroc nose cones below (BC-723P, 730P, and 734P) because they approximate the Centuri PNC-73, 76, and 74 cones (at least to *my* eye).

If you use these files, make sure you don't use the "Nose cone base diameter" option to figure stability. Instead, pay attention to the "User defined diameter," which in these cases is specified as the outer diameter (O.D.) of a Semroc ST-7 body tube."

Questions? Comments? Please reply below.


Cheers,
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Name:  Centuri_Semroc_Nose_Cones_030X - Jan 2019.png
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Name:  BC-7xxP_NoseCones_Semroc.jpg
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Attached Files
File Type: rkt BC-723P_NoseCone_Semroc.rkt (11.4 KB, 34 views)
File Type: rkt BC-730P_NoseCone_Semroc.rkt (10.3 KB, 32 views)
File Type: rkt BC-734P_NoseCone_Semroc.rkt (11.4 KB, 34 views)
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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
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  #2  
Old 01-12-2019, 11:48 PM
teflonrocketry1's Avatar
teflonrocketry1 teflonrocketry1 is offline
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Jay,

Thanks for posting these files; I think these are great!

Since I 3D print nosecones directly from RockSim using the Export 3D model function; I prefer to print these 2 part constructs using a smoother more tangential fit between the nosecone tip section and the transition following it, see attached files. For blunted ogive nose cones like these; I use a Power series shape (Shape control 0.3 to 0.6) for the tip part and a Sears Haack (Von Karmen) shape (Shape Control 0.45 to 0.75) for the transition.
Attached Files
File Type: rkt BC-723P_Semroc_NC.rkt (11.0 KB, 31 views)
File Type: rkt BC-730P_Semroc_NC.rkt (10.9 KB, 29 views)
File Type: rkt BC-734P_Semroc_NC.rkt (10.9 KB, 31 views)
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  #3  
Old 01-13-2019, 12:52 AM
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Tau Zero Tau Zero is online now
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Quote:
Originally Posted by teflonrocketry1
Jay,

Thanks for posting these files; I think these are great!

Since I 3D print nosecones directly from RockSim using the Export 3D model function; I prefer to print these 2 part constructs using a smoother more tangential fit between the nosecone tip section and the transition following it, see attached files. For blunted ogive nose cones like these; I use a Power series shape (Shape control 0.3 to 0.6) for the tip part and a Sears Haack (Von Karmen) shape (Shape Control 0.45 to 0.75) for the transition.
Bruce,

Thanks for the kind words! They're much appreciated!

Yes, I see what you mean. Your method is *much* smoother. Of course, I originally cobbled these together back in 2007, so...

And for the record... Thanks for bein' so stinkin' smart.


Cheers and blessings,
.
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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
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  #4  
Old 01-13-2019, 12:20 PM
teflonrocketry1's Avatar
teflonrocketry1 teflonrocketry1 is offline
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Location: Whitehouse, Ohio
Posts: 264
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Jay,

Thanks for the complement! I am glad to be part of this hobby that allows me to explore and learn new things on an almost daily basis and to help out people that have a similar interests!

Bruce
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