Guided without fins. Cone

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ASA

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I have been thinking for a while about stabilizing a rocket without fins. Should be easy. Basically move the center of pressure back on the rocket.

To do that I built a paper cone to cover the fin area. It flew straight. My next modification will be to reduce the cone diameter and then the taper.

voncone.JPG


My test mule came to me in a state park about 15 years ago. I found the tube (with US Army insignia) which had plastic motor/fin mount and some broken fins. After carving a balsa nosecone and rebuilding the fins I've flown it numerous times.

I recently lost it (with fins) in my own forest for about 2 or 3 weeks which included a couple of inches of rain. It is getting rough. Not my usual build quality.
 
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Cone rockets have been around a while now. I was reluctant to ever build one simply because I like fins better. BUT, I had a change of heart when I thought of installing siren whistles in one....Hmmmmm, SO, I came up with an idea that I thought might have an advantage over other peoples failed attempts to make a successful whistling rocket. There are 3 BT 50 chamber tubes going through the cone, although you can only see two. The siren whistles are in them. My idea was to use a D motor in it to power up enough, but not so that the whistles would seize. Still don't know if they do. Either you can't hear them over the motor, or the rocket just isn't fast enough to sound them off. Anyhoo, it's flies pretty well. I call it, The Whizzler.

Whizzler.jpg
 
I like your style.
There are fireworks that have whistlers on them. Maybe some deconstruction of them would yield results for you.

I hadn't hear about cone rockets but there is nothing new under the sun.
 
I like your style.
There are fireworks that have whistlers on them. Maybe some deconstruction of them would yield results for you.

I don't think you're going to find a whistle in the bottle rocket. There's a certain type of whistling fuel used, that makes them whistle.
 
No, I mean a motor that uses potassium perchlorate/potassium benzoate whistle fuel, that would whistle as it flies (like a bottle rocket basically). I wonder what's to stop Estes from making a NAR certified version of that, which could be used in a cluster for HPR...
 
No, I mean a motor that uses potassium perchlorate/potassium benzoate whistle fuel, that would whistle as it flies (like a bottle rocket basically). I wonder what's to stop Estes from making a NAR certified version of that, which could be used in a cluster for HPR...

Oh, you stated "rocket" not motor. I suppose that kind of fuel falls into a "firework" category, which rockets are not.
 
There's no need to test to destruction, cone fin rockets should be swing test and wind test able. Simulation is more a mixed bag. I built a long rocket using a milk bottle part as the cone fin and Open Rocket showed it highly stable (!) and it was much less so. I think in that one the milk bottle shape was as smooth to the air as it looked (this also showed the idea of "base drag" as a stabilizer is bunk).

I also built rockets using a 5.5" cone piece. The first had an identity crisis, is it a rocket or a saucer?, and too little recovery gear space caused crashes, so I rebuilt it with a lot more tube. This is almost as draggy as a regular 5.5" diameter rocket, thus lightweight compared to the motor required. If it weren't for the relatively good simulation performance on E9 motors, probably wouldn't have built it. It's a cool cheap flight but better motors have been no big improvement.


Peak of Flight 379 - Finless Rockets

That is interesting!
 
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I always have tested by swinging. The author of the article really takes a punch at that technique and NAR.

Sounds like he knows what he is talking about Kind of making a non-after burner. I seem to remember that there was a test airplane that did something similar with a 10,000 holes.

Most of my aero skills are empirical for our 2 wheeled streamliners with very little exhaust. I am interested in experimenting with it. Time to cut the cone off.
 
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