Giving rear ejection recovery method another try leads to a whole new adventure in model rocketry

Discussion in 'Beginners & Educational Programs' started by John Rozean, Nov 25, 2018.

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  1. Nov 25, 2018 #1

    John Rozean

    John Rozean

    John Rozean

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    Just me thinking out loud about some of the things I am learning about model rocketry. Discussed are homemade rocket designs, rear ejection recovery methods, center of pressure (CP), center of gravity (CG), and OpenRocket. Writing about these things seems to aide in my learning process.

     
  2. Dec 1, 2018 #2

    BABAR

    BABAR

    BABAR

    Builds Rockets for NASA TRF Lifetime Supporter TRF Supporter

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    Interesting thoughts. Congratulations on a successful rejection project that’s not easy to do. If you haven’t already read Stine’s “Handbook of model rocketry book” I think you’ll find it very interesting it will help you complete some of your thoughts and certainly stimulate new ones. Like you, I really enjoy scratch Rocket design and building. Hope to see some more of your projects soon.
     
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  3. Dec 2, 2018 #3

    JStarStar

    JStarStar

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    Your models look well built with some cool names and color schemes.

    It's always interesting to compare flight simulations in OR or RockSim and try to figure out where "anomalies" come from.

    Looking at the OR diagram of your rocket in the video, I'd guess possibly your model might have been slightly over-stable-- it looked like stability margin > 2 calibers ... which combined with launching with a rod tilted into the wind, may have resulted in weathercocking and rod tip-off, in turn resulting in a near horizontal flight (very low and straight into the wind).

    As you mentioned it is not always easy to get good chute deployment with rear eject models. Chute melting, shock cord getting tangled on ejection, etc etc. lots of potential problems!
     
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