Blackhawk 38 Questions

Discussion in 'High Power Rocketry (HPR)' started by TheNewGuy, Feb 11, 2019 at 7:11 AM.

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  1. Feb 11, 2019 at 7:11 AM #1

    TheNewGuy

    TheNewGuy

    TheNewGuy

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    I just finished attaching the fins, and after doing some reading here on TRF I still have some questions.
    1. My plan is to send this thing as high as it will go, and also to install my own electronics I've built myself. Is dual deploy recommended on this rocket?
    2. For dual deploy, do I use shear pins to secure the upper and lower body tubes to the coupler? Or is there a more recommended way of fixing the coupler to the body tubes?
    3. If one my ejection charges go off, won't it shear both upper and lower pins?
    4. How do I attach my Kevlar shock cord to the top of my Cesaroni rocket motor? I couldn't find anyone selling a forward closure to attach a cord to.
    5. If #4 isn't recommended, and if I go with the standard way of attaching recovery gear in a blackhawk, should I drill a countersunk hole and use a countersunk machine screw to affix that 1" long piece of coupler right above the end of your motor? Would the fiberglass body tube be strong enough for the countersunk hole?
    Thank you in advance for advice anyone might have.

    I can't wait to start flying. I'm building a tracker out of an Arduino Nano and a RFM95W LoRa Module. I also have a couple of ideas for cool payloads to fly as well.
     
    Last edited: Feb 11, 2019 at 7:16 AM
  2. Feb 11, 2019 at 12:31 PM #2

    markg

    markg

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    It's a great kit that'll fly on a variety of motors. It's a bit of a tight squeeze for DD, if this is your first DD I'd suggest building a 2.6" or 3" kit as your first DD instead.

    For your questions :

    1 - yes
    2 - yes
    3 - no
    4 - attach to coupler in body tube above motor (see thread below
    5 - not necessary

    Follow CJ's build thread and you can't go wrong :

    https://www.rocketryforum.com/threads/new-wildman-38mm-blackhawk-prototype-first-look.16374/

    cheers - mark
     
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  3. Feb 11, 2019 at 2:56 PM #3

    GRIFFIN

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  4. Feb 11, 2019 at 2:58 PM #4

    captbk

    captbk

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    If you are going for max altitude then definitely go DD. Mine's has been as high as 11500' and it has taken all I've thrown at it. I use one sheer pin at the booster and av-bay, one at the nose cone which holds the gps tracker, and I use three pins to hold the av-bay and payload tube together. I also go so far as to cut all my sheer pin heads off. I was told I could get a few more feet alt doing it. I have always used Loki and AT hardware so I attach my shock cord to an eye bolt in the forward closure. I also friction fit my motor hardware. Yes DD in a 38mm rocket is a challenge but very do-able and I dont see a need to go bigger first but thats me. If you are worried about popping all your pins at once, ground test...a lot! A deployment charge that is a little too big can pop both pins. Ive had it happen to me and Ive found that a .5g charge in both sections is all you will need. Its such a small space you are pressurizing, it doesnt take much. Ground test for sure and good luck.
     

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