I want a whistle

[PSLimo]

I've built a few Army Hawks from 2.6" to 7.5" and they all whistle on the way up. The faster and harder you hit them, the louder they whistle.

The shorter the motor burn time the longer you could enjoy the whistle.

 

[KenECoyote]

I tried a Rocketaruim Mega Vortex with whistles mounted underneath since it spins on coast, but I didn't hear anything.



I may try it again with the whistles mounted further out.

 

[Handeman]

I built a split fin but ended up calling Dog Whistler.

 

[Ladykate]

I tried a Rocketaruim Mega Vortex with whistles mounted underneath since it spins on coast, but I didn't hear anything.

View attachment 550612

I may try it again with the whistles mounted further out.

I agree about sticking them out on the edge. I just finished the 24mm version of the rocket I posted earlier. Might also mount a couple of light whistles on the outboard of one of the 'Whirl and Hurl's (on Thingiverse). They are fantastic spinning performers and have a unique sound in their own right.

 

[RocketScientistAustralia]

The whistle on the left is a modified version of the one on the right. The one on the right was found on thingiverse as a multi frequency arrow whistle. I cannot find it there now so apologies to whoever designed it for not crediting them. Each hole resonates a different sized chamber. This gives you more of a chance of getting the rocket to actually whistle. The one on the left was fitted to the nosecone of a Der Red Max. It whistles. You do need to print it at a fine resolution. Enjoy. Scale at your own risk. Scaling will definately change things significantly.
Norm

 

[OverTheTop]

Put a harmonica on each leading fin edge. Bonus points for choosing a chord that sounds good .

 

[RocketScientistAustralia]

Put a harmonica on each leading fin edge. Bonus points for choosing a chord that sounds good .

If only it were that simple. When you blow through a harmonica or a normal whistle, the air velocity is low. What this is more like, is the annoying whistle you get from a roof rack. But now you want to recreate it........... And louder.....

 

[lakeroadster]

View attachment 571668
The whistle on the left is a modified version of the one on the right. The one on the right was found on thingiverse as a multi frequency arrow whistle. I cannot find it there now so apologies to whoever designed it for not crediting them. Each hole resonates a different sized chamber. This gives you more of a chance of getting the rocket to actually whistle. The one on the left was fitted to the nosecone of a Der Red Max. It whistles. You do need to print it at a fine resolution. Enjoy. Scale at your own risk. Scaling will definately change things significantly.
Norm

Norm,

Any chance you have these files as cad part files instead of stl's?

Thanks

 

[RocketScientistAustralia]

Norm,

Any chance you have these files as cad part files instead of stl's?

Thanks

They are not my files. So no other format. You can import an STL file into SCAD. You need to re-render after the import as it sometimes does not show.
The one I modified was done by importing into SCAD, scaling in the direction I wanted and removing a bit off the bottom.
Here's what that looks like.

That's the STL file just "open with" SCAD. It automatically writes the file import command when you do that. One trick to using an STL file is to make sure it's centered. You can do that by opening the STL in CURA, select "center on build plate" highlight it and then export selection. Export as an STL file with a modified name like" WhistleCentered.stl" then "open with" SCAD.
Norm

 

[fyrwrxz]

I added three coaches whistled into the fins of a Thumper Jr. (The green and white one in the Polecar catalogue). Forgot to beef up the ejection charge on an I motor. It cratered 50 feet behind me and never whistled once. Saved the chute and kevlar. Scrapped my pride that day along with the rest of the rocket.

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

 

[RocketScientistAustralia]

I added three coaches whistled into the fins of a Thumper Jr. (The green and white one in the Polecar catalogue). Forgot to beef up the ejection charge on an I motor. It cratered 50 feet behind me and never whistled once. Saved the chute and kevlar. Scrapped my pride that day along with the rest of the rocket.

I bought 20 plastic whistles, Strapped them to a rocket in various spots, put funnels on the intake etc etc. Nope...... Came across the arrow whistles. They work at the speeds we fly at. Whoodathought?

Norm

 

[lakeroadster]

They are not my files. So no other format. You can import an STL file into SCAD. You need to re-render after the import as it sometimes does not show.
The one I modified was done by importing into SCAD, scaling in the direction I wanted and removing a bit off the bottom.
Here's what that looks like.
View attachment 571777
That's the STL file just "open with" SCAD. It automatically writes the file import command when you do that. One trick to using an STL file is to make sure it's centered. You can do that by opening the STL in CURA, select "center on build plate" highlight it and then export selection. Export as an STL file with a modified name like" WhistleCentered.stl" then "open with" SCAD.
Norm

Thanks Norm.

Today I was able to open the file in Free Cad and view it as a wire mesh.

For those interested, there's more than meets the eye in regard to these simple looking nose cones. There are multiple internal chambers with convex surfaces.

I had hoped to be able to open these with my old copy of Autodesk Inventor, and then make some drawings of the internals, but the program pre-dates STL files.

 

[BABAR]

View attachment 571668
The whistle on the left is a modified version of the one on the right. The one on the right was found on thingiverse as a multi frequency arrow whistle. I cannot find it there now so apologies to whoever designed it for not crediting them. Each hole resonates a different sized chamber. This gives you more of a chance of getting the rocket to actually whistle. The one on the left was fitted to the nosecone of a Der Red Max. It whistles. You do need to print it at a fine resolution. Enjoy. Scale at your own risk. Scaling will definately change things significantly.
Norm

Do they work?

 

[RocketScientistAustralia]

Do they work?

Launched the one shown on the nosecone of a red max on a G76 yesterday. It whistles loudish. Interesting noise with the harmonics of the different whistles simultaneously. Obviously, you don't notice the whistle during the motor burn. The motor makes a bit more noise.... So a short burn with a long coast would maximise whistle duration.
Here it is on the pad and I can provide contact details of the whistling witnesses if that's required......


I'll be fitting one on each fin tip for the next flight. That'll whistle......