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lakeroadster

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My mind wanders to rocketry when doing mundane home improvement stuff...

Has anybody built a tube finned rocket, lets say 6 fin tubes, and made (3) of the fin tubes scratch built whistles?

The rocket would sing to you on it's way to apogee.

John
 

neil_w

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Has anybody built a tube finned rocket, lets say 6 fin tubes, and made (3) of the fin tubes scratch built whistles?
I can't provide links right now, but I gather that it's very difficult to get a rocket to whistle in that manner, at least so that you can actually hear it. Worth trying though. :)
 

lakeroadster

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I can't provide links right now, but I gather that it's very difficult to get a rocket to whistle in that manner, at least so that you can actually hear it. Worth trying though. :)
Maybe put some mirrors on it off a '76 Chevette... :music1:

I was thinking whistles designed like a pipe organ pipe... sound coming out the back of the fin tubes? Maybe a little R&D with my air compressor...
 

kuririn

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OK, found the bag.
I think it's actually called a Nerf whistling dart, launched from one of their blaster guns.
The top orange part is the whistler, and it needs to be in the airstream.
So I was going to cut it off and glue it into the top of the BT-20 tube fin.
I forgot how big this rocket was.
Maybe I'll move it up the build queue.
0103211933[1].jpg

Laters.
 

BABAR

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I have tried multiple things without success, including real whistles (with a scoop funnel!), vaianky split fins, various size lateral fin holes, tubular “whizzers”, without success. The nerf things sound promising.
 

BABAR

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See post 23
 

aerostadt

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We had a discussion in a TRF thread about 8 years ago about LPR rockets with whistles. I used those gag-type whistles and for me the results were uncertain. The thinking is that you need a high acceleration to get enough air flow to make the whistle, like with a D-motor, but the D-motor may make enough noise to drown out the whistle. Secondly, a high acceleration gets the rocket farther away from the listener, so that the sound is then fainter. Thirdly, if you are at a Club launch with an electric generator running, the background noise can drown out the whistle. I think I have heard people talking about Nerf whistles before, but I have never read any reported results.

 
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kuririn

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Yeah, the whistle sound is much more apparent when the dart is approaching you than when you are shooting the dart at someone else. So the best way to hear the whistle is if the rocket is.............
Never mind.
If the cheap novelty fireworks can produce a loud whistling projectile then someone should be able to figure out a way with rockets.
 

aerostadt

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This was the thread that Gary Byrum started about 6 years ago. If you search TRF, you can find lots of discussion of whistling.

 

SDramstad

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Yeah, the whistle sound is much more apparent when the dart is approaching you than when you are shooting the dart at someone else. So the best way to hear the whistle is if the rocket is.............
Never mind.
If the cheap novelty fireworks can produce a loud whistling projectile then someone should be able to figure out a way with rockets.
Then the logical thing to do is put the whistle on backwards so you can hear it..... :p

I have a few split fin rockets that have gotten to whistle on purpose and I built a 3 inch diameter Jayhawk which really surprised me when it whistled quite loudly.

i-HjG9SBk-X2.jpg
 

kuririn

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I have a few split fin rockets that have gotten to whistle on purpose and I built a 3 inch diameter Jayhawk which really surprised me when it whistled quite loudly.
I have a Sky Wolf that hasn't maidened yet that I'm hoping to get to whistle.
Do you know why the Jayhawk gave off a whistle? Wondering what mechanics would have caused that since there are no split fins.
 

SDramstad

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I have a Sky Wolf that hasn't maidened yet that I'm hoping to get to whistle.
Do you know why the Jayhawk gave off a whistle? Wondering what mechanics would have caused that since there are no split fins.
Not yet. I have had some problems with it. Used motor eject on its first flight and the 2 G125s didnt have enough powder to blow off the nose cone.... ballistic recovery onto a paved road. Salvaged the fins and motor mount and put in an altimeter but the apogee charge igniter opened up after launch. The main came out ok but zippered the body tube. Rebuilt it again except for paint which I will do soon but our club isnt launching right now due to Covid..... Hopefully the spring will be kinder to us. Will update things as it goes.
 

aerostadt

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See that makes me think that an MPR or HPR is going to whistle much better using fins for the whistle mechanism.
 

Kelly

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If the cheap novelty fireworks can produce a loud whistling projectile then someone should be able to figure out a way with rockets.
Fireworks that whistle do so by using a propellant that exhibits an oscillatory burning, not by utilizing an airflow. Unfortunately that propellant is probably not safe enough for use in rocketry, and isn't permitted at NAR/TRA launches.
 

kuririn

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Not safe for rocketry but still available for any Tom Dick or Harry to buy from a store?
Yikes!
 

Kelly

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Not safe for rocketry but still available for any Tom Dick or Harry to buy from a store?
Yikes!
Well, you won't find a 'J' impulse whistle rocket at a fireworks stand. Some of the danger is involved in the manufacture, as well. Keep in mind that TRA doesn't allow use of research blackpowder rockets, either.
 

icyclops

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My mind wanders to rocketry when doing mundane home improvement stuff...

Has anybody built a tube finned rocket, lets say 6 fin tubes, and made (3) of the fin tubes scratch built whistles?

The rocket would sing to you on it's way to apogee.

John
They used to sell the nerf footballs with 3 or 4 little whistle mechanisms distributed around it’s widest diameter....they worked very well if you through a spiral.....don’t know if they still sell them or how they were attached. They were very small if I remember correctly.
 

BABAR

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Yeah, the whistle sound is much more apparent when the dart is approaching you than when you are shooting the dart at someone else. So the best way to hear the whistle is if the rocket is.............
Never mind.
If the cheap novelty fireworks can produce a loud whistling projectile then someone should be able to figure out a way with rockets.
Fireworks whistle is due to the flow through the nozzle. Not an option with current commercial motors . Might be something Estes or Aerotech could do, a whistling motor might be a draw, sort of the audio equivalent of a sparky motor. I want my C5-0 first.
 

Daddyisabar

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If you want a true whistling rocket you need to join a pyrotechnic club. Mix up a batch of whistle mix, very similar to commercial BP propellant. Then see Guys on site making their own black powder motors on the tailgates of their pick em up trucks with dies and mallets. Bang bang bang go the mallets. Some even have presses with lexan shields. Things that model rocketeer Jedi would consider unnatural.
 

lakeroadster

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If you want a true whistling rocket you need to join a pyrotechnic club. Mix up a batch of whistle mix, very similar to commercial BP propellant. Then see Guys on site making their own black powder motors on the tailgates of their pick em up trucks with dies and mallets. Bang bang bang go the mallets. Some even have presses with lexan shields. Things that model rocketeer Jedi would consider unnatural.
<-----<<<
 

DES

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Fireworks whistle is due to the flow through the nozzle. Not an option with current commercial motors . Might be something Estes or Aerotech could do, a whistling motor might be a draw, sort of the audio equivalent of a sparky motor. I want my C5-0 first.
The fireworks whistle is a special composition incorporating shock sensitive chemicals into the fuel. Typically sodium benzoates plus burn catalysts. The whistle is caused by rapid oscillation of the burning fuel, rapid shockwaves that quickly alter the burn rate up and down in the sonic kHz range. Most whistles have a completely open bore throat, otherwise they will detonate. While you can get thrust, they are not very efficient for rocket motor use, and the BATF would probably label it as an explosive.
 

BABAR

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The fireworks whistle is a special composition incorporating shock sensitive chemicals into the fuel. Typically sodium benzoates plus burn catalysts. The whistle is caused by rapid oscillation of the burning fuel, rapid shockwaves that quickly alter the burn rate up and down in the sonic kHz range. Most whistles have a completely open bore throat, otherwise they will detonate. While you can get thrust, they are not very efficient for rocket motor use, and the BATF would probably label it as an explosive.
Thanks for the correction. I knew it wasn’t coming from the aerodynamics of the fireworks rocket, but I should have reviewed before posting.
 

jqavins

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(No time to read the whole thread at the moment. I'll get back to it.)

If you do get a three whistle rocket to work, please tune their frequencies in a 4:5:6 ratio. That's a major chord.
 

Cape Byron

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Okay, work with me here...

Bagpipes have a mouthpiece reed and three drones. The drone reeds have a constant airflow through them supplied by the bag. Maybe something similar? The airflow through a drone reed wouldn't be that high.
 

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