I want a whistle

Discussion in 'High Power Rocketry (HPR)' started by kramer714, Jan 28, 2013.

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  1. Jan 28, 2013 #1

    kramer714

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    Playing with some 4 inch designs fora K-L size motor. Here is the thing, I want a rocket that whistles, really loud whistle, JU-87 loud, did I mention I'm looking for a whistle.

    I'm even thinking of adding a motor driven or small CO2 driven whistle if i cant get the Db from the rocket itself.

    Anyone have a design for a whistle?

    Mike k.
     
  2. Jan 28, 2013 #2

    Jimmy F.

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    You need to use a split fin design.
    Try something with the bottom fin set's leading edge perpendicular to the airframe
     
  3. Jan 28, 2013 #3

    troj

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    Split fins, squared trailing edge on the forward fin, and squared leading edge on the trailing fin, and you don't want them quite perfectly aligned.

    That said, it's not going to be as loud as what you're after.

    -Kevin
     
  4. Jan 28, 2013 #4

    Mightyrocketman

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    Find some wooden whistles and incorporate them on the fins or make some. A friend told me that someone where he was launching had made a rocket with wooden train whistles that broke window out when it was flown.
     
  5. Jan 28, 2013 #5

    patelldp

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    I am not really sure what causes the whistle. I've heard some weak whistle sounds from split fin rockets, and I have heard stronger whistles from non-split fin rockets. For example, my father's NCR Big Brute has whistled quite loudly with an H128W in the past.
     
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  6. Jan 28, 2013 #6

    JP Morgan

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  7. Jan 28, 2013 #7

    chadrog

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  8. Jan 28, 2013 #8

    qquake2k

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    I've noticed the same thing. Some split fins whistle like crazy and some don't. Likewise with non split fin rockets. Some whistle and some don't. I've thought about trying siren whistles, and even bought some plastic ones off Ebay, but haven't tried them yet. I think you'd need pretty high velocity to make the whistles work. Estes used to make the "Screamin' Mimi", but I understand it didn't whistle.

    http://www.rocketrytoday.com/screaminmimi.html
     
  9. Jan 28, 2013 #9

    kjohnson

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    You could make sort of an air-raid siren that spins when the rocket is flying by either drilling out two plates (like a clown whistle) or making something more complicated with slots and slats and stators. Mount it in the nose, or in a section of tube and make it spin with small rotors that get blown by the rocket moving through the air. I recently saw a video on youtube of a guy making his own air raid siren in his shop.

    kj
     
  10. Jan 28, 2013 #10

    Pantherjon

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    Yep, split fin design..Space between the fins should be between 1/2"-1", and the trailing edge of the front fins and leading edge of back fins should be SQUARE.This creates the most turbulence which produces the louder whistle.
     
  11. Jan 28, 2013 #11

    T-Rex

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    The most common commercial design that whistles is the LOC Athena / BSD THOR. Rocksim files for the designs are available on the web. They are not all that difficult to clone.
    I'm fairly sure you could cut slots in the fins of any rocket to make them whistle. The difficult part is the exact specifications for the slots. One would need to talk to a whistle engineer (?) to get that information.
     
  12. Jan 28, 2013 #12

    jadebox

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    Chris (hcmbanjo) did some experiments trying to come up with a model rocket design that would reliably whistle. He tried many things including using half a fishing bobber that someone recommended, addind store-bought whistles, carving a whistle into the fins, using split fins, and more. Nothing worked reliably. It seemed that right after each of Chris's experimental launches, someone would launch a rocket based on a kit and ... it would whistle. :)

    -- Roger
     
  13. Jan 28, 2013 #13

    chuck5395

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    Kits on the market today that are similar to the ones you list are the Madcow Frenzy (the 4' cardboard version) and the Binder Design Samurai and Raptor. I have the Madcow Frenzy and the fins are just like Pantherjon mentioned. It's a screamer...
     
  14. Jan 28, 2013 #14

    kandsrockets

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    Also our Blue Wolf 54 Split fin and our Windjammer kit. The only thing I found with split fins and whistling is it depended on the speed.
     
  15. Jan 28, 2013 #15

    NateB

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    A motor that whistles loudly while burning and has plenty of lifting capability is possible to make, however it is a very dangerous mixture and requires some specialized equipment and tooling.
     
    Last edited: Jan 28, 2013
  16. Jan 28, 2013 #16

    Rex R

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    judging from my attempts and the MC super batray, you want to get the rocket up to speed quickly before it gets over say 500' with a fairly short motor burn(H148 works nicely for me in the sbatray).
    rex
     
  17. Jan 28, 2013 #17

    Green Jello

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  18. Jan 28, 2013 #18

    jpummil

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    TRUE!

    My Darkstars make hardly any noise at all, but my 3" Thor is a whistling beast! Go figure...
     
  19. Jan 28, 2013 #19

    NateB

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  20. Jan 29, 2013 #20

    Handeman

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    I built a 3" rocket with a fins that were tapered. 3/4" thick at the base, 1/4" wide, 3.5" out at the tip. They had a 1/2" wide slot in the center. Build Thread here

    I also wanted a good whistle. I now call the rocket Dog Whistler. I've never heard it whistle. Other claim they have heard it, but I haven't.

    A 1/2" slot with square faces is no guarantee of a whistle.
     
  21. Jan 29, 2013 #21

    Rocketeer Gator

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    How about build a tube fin rocket and glue a couple of these train whistles inside the tubes and duct air into them with another piece of tube.Hard to explain in type but I have a picture in my head that might work.....
     
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  22. Jan 29, 2013 #22

    CarVac

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    I have glued whistles like those on Vortex nerf footballs to a LPR, but it moved much faster than the whistle's operating speed so I didn't hear it at all.
     
  23. Jan 29, 2013 #23

    Mightyrocketman

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    Works on a Big Daddy. Can only hear it after motor burnout though.
     
  24. Jan 29, 2013 #24

    Wizard

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    The Madcow Phoenix also has a pretty good whistle- I always hear mine shortly after burnout. I left the LE and TE of both sets of fins square, plus the TE of the front and LE of the rear fins at perpendicular to the airframe, so it meets the aero criteria pretty well.
     
  25. Jan 29, 2013 #25

    Kaycee

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    What you want is a quick boost (<1 sec.) so you can actually -hear- the whistle from the combination of airframe and fins. My favorite -whistling- rocket was my Loc Magnum. I launched it many times on AT I-357s. Quick burn, then the whistle...best I've heard yet, and although it didn't fly very high it got everyone's attention.
     
  26. Jan 29, 2013 #26

    RocKiteman

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    Was that window broken from the sound the whistles made, or was the rocket just a bit, uh, “off-course”...?

    :wink:
     
  27. Jan 29, 2013 #27

    JStitz

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    I think I remember from "Rocketry Planet" someone doing a simple hole saw cut "Swiss Cheese" fin rocket and they whistled nicely.
    And it would reduce weight....might have been Jim Conn from Orangeburg....Anyone remember?


    John Stitz
     
    Last edited: Jan 29, 2013
  28. Jan 29, 2013 #28

    Green Jello

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    Has anyone flown their Madcow Piranha yet? I know many of us bought that one when it was on the Black Friday special.
     

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  29. Jan 29, 2013 #29

    Mightyrocketman

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    Sound of the whistle. I believe he told me 4 were on the rocket. It was 4 of the wooden train whistles that you can get at tourist souvenir shops.
     
  30. Jan 29, 2013 #30

    UPscaler

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