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Thread: "Its A Dud"

  1. #1
    Join Date
    19th March 2009
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    "Its A Dud"

    Hey guys,
    Here is a piece of scrap metal that's the inspiration for an Oddroc I'm building. I'm stacking and shaping styrofoam that will be the core that I'll fiberglass over to become the body. The fins will be plywood and fiberglass. I just hope I can get it to fly right without having to add a lot of weight to the nose. Pictures attached. Comments please.

    Thanks,
    Harry Keyes
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  2. #2
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    18th January 2009
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    Looks cool...

    I've been toying with the idea of making a Mark IV atomic bomb... Always thought it looked rather elegant... I figured that making the tapering body out of fiberglass laid up over a form carved from flower foam balls/cones from Hobby Lobby would be the easiest way to go, then dissolving the foam out with acetone once the fiberglass had set up.

    It would be cool to set the thing up for rear ejection with the parachute coming out of the rear, similar to the high-yield hydrogen bombs dropped from B-52's, though of course the Mark IV was never parachute retarded...

    Your project looks pretty similar... OL JR
    The X-87B Cruise Basselope- THE ultimate weapon in the arsenal of homeland defense and only $52 million per round!

  3. #3
    Join Date
    18th January 2009
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    been dumpster diving at Pantex again?

    that will be cool looking...be sure to plaster "inert" all over it, or you might have a visit from federal authorities!!

  4. #4
    Join Date
    19th March 2009
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    Amarillo, TX
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    I finally finished my oddrock copied from the ordinance tailpiece. It shows to be stable, but I couldn't figure out how to figure the fin box section in on
    Rocksim. I know there has to be some Rocksim experts out there. What do you think.
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  5. #5
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    19th March 2009
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    Mini Nuke - was Its a Dud.

    Here's another picture, from a different angle.
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  6. #6
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    18th January 2009
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    Beautiful build, but I wonder: if the fins are in the bulbous nose cone's aerodynamic "shadow," will they be able to do their job? Gravity bombs aren't propelled; they simply follow a ballistic trajectory to the ground after being dropped from above. I'm guessing that the fin assembly on them is there to keep them from tumbling as they fall? If so then they might not be adequate for the job that a rocket's fins must perform. I hope that I'm wrong about this, because I really like your build.
    Mark S. Kulka NAR 86134 L1, ASTRE 471, Adirondack Mtns., NY
    Opinions Unfettered by Logic • Advice Unsullied by Erudition • Rocketry Without Pity
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  7. #7
    Join Date
    15th May 2009
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    Quote Originally Posted by MarkII View Post
    Beautiful build, but I wonder: if the fins are in the bulbous nose cone's aerodynamic "shadow," will they be able to do their job? Gravity bombs aren't propelled; they simply follow a ballistic trajectory to the ground after being dropped from above. I'm guessing that the fin assembly on them is there to keep them from tumbling as they fall?
    Very nice looking build. I think (with no written documentation to back me up) that the airflow around the bomb part "wraps" a little to still get to the fincan, else it would be useless on the real bomb as well. Kind of like the laminar airflow over a wing, or around the relatively fat body of a scale V2. The fin assembly keeps the Cp behind the Cg for stability. On a real bomb, though, the Cg will be substantially forward, so this one will need a lot of nose weight. I suppose if you just dropped one of our rockets out of an airplane, it would line up with the relative wind in the direction of fall, just like a bomb would.
    Wisconsin Organization of Spacemodeling Hobbyists
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  8. #8
    Join Date
    20th March 2009
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    329
    Cool build. Thanks for posting it!

    Sandy.

  9. #9
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    4th March 2011
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    That's right- unless you really weight the nose down............ ouch! But who cares? It's FUN to experiment, so let's just see what happens. You can always repair

    But one thing: I recommend using a motor size that will get it under 600 feet. If you push this with too many newtons, it won't be stable at all. Just my 2-cents. Good luck, nice job!
    Last edited by jeffgeraci; 24th August 2011 at 05:55 AM. Reason: more info
    Fair winds, soft landings, and total victory! -

  10. #10
    Join Date
    18th January 2009
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    This does look very cool. I suppose you could get RockSim 9 to design the fins by properly aligning 2 fins mounted on a 'pod' that is attached to each radial fins. The bulbous body might occlude the fins. I had a rocket that used an 8" diameter plastic bin form Utz pretzels as a nose. The body was 3" and the fins were pretty big. Flew well on an H123 but was unstable on the H242. I've also heard of such issues on other similar rockets. However, SMR may be correct that the smooth shape might help in this regards. I for one would tend to make it statically stable with a good margin and then just not fly it too fast (on the first flight). Heads up flight of course.
    Dick Stafford
    The Original Rocket Dungeon
    Volunteer compiler of product news for ROCKETS Magazine

  11. #11
    Join Date
    2nd March 2010
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    Milk Dud

    Just something to think about if your thinking of decaling it.
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    NAR 90998
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  12. #12
    Join Date
    4th March 2011
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    Quote Originally Posted by Scotty Dog View Post
    Just something to think about if your thinking of decaling it.
    Scotty is DEFINITELY onto something- GREAT IDEA!!!
    Fair winds, soft landings, and total victory! -

  13. #13
    Join Date
    19th March 2009
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    Amarillo, TX
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    Mini Nuke - was Its a Dud.

    Here is a video of my Mini Nuke flying at LDRS XXX.
    It flew pretty well even with the wind.
    Harry Keyes


    http://www.youtube.com/watch?v=5s3xqMAnF4c

  14. #14
    Join Date
    18th January 2009
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    Maryland
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    Great flight! Thanks for following up.
    Dick Stafford
    The Original Rocket Dungeon
    Volunteer compiler of product news for ROCKETS Magazine

  15. #15
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    16th March 2011
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    That is totally COOL!!

    Eric Foster
    Eric Foster
    http://www.BaddAzzRocketry.com
    Eric@BaddAzzRocketry.com
    TRA 12959 L3
    Home Club Tripoli SC

  16. #16
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    20th January 2009
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    NICE!!!! Was thqt the motor or the fins whistling on the way up?

  17. #17
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    18th January 2009
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    Cool... Looks like Davy Crockett...

    daveycrockett3.bmp
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    Later! OL JR

    PS. Nice flight!
    The X-87B Cruise Basselope- THE ultimate weapon in the arsenal of homeland defense and only $52 million per round!

  18. #18
    Join Date
    18th January 2009
    Location
    Chicago, IL
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    66
    Very nice! Loved the whistle.

    As for the subject of decaling it...might I ask, are you familiar with the video game "Fallout 3?"

    http://fallout.wikia.com/wiki/Mini_nuke_%28Fallout_3%29

    Just sayin'.

    Oh, and I've been gone for quite a while (few months short of two years, in fact). So hi is anyone remembers me.





  19. #19
    Join Date
    15th February 2011
    Posts
    241
    there is a short video on the history channel H2 series "modern marvels" called
    tiny weapons it talks about the Davie Crockett weapon system.

    Check it out !!

    Bobby

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