Theories on Flight Stability and Big Honkin' Fins

Theories on Flight Stability and Big Honkin' Fins

Post by go4s.. » Sat, 04 Nov 2000 04:00:00



Folks,
   I am in the final stages of cloning a Starship Vega. It is your
basic 9FNC4BT3L (nine fin, nose cone, 4 body tubes, 3 legs) rocket.
It's a great looking rocket, but I haven't seen anything this bottom
heavy since this girl I knew in high school. Will the large fin area
give it all the stability it needs, or should I add plenty of nose
weight?

--Steve

Sent via Deja.com http://www.deja.com/
Before you buy.

 
 
 

Theories on Flight Stability and Big Honkin' Fins

Post by Fred Shecte » Sat, 04 Nov 2000 04:00:00


The center of gravity needs to be in front of the center of pressure.
Period.

Use a simulation program to find the center of pressure.  Insert an engine
and balance on your finger to find the center of gravity.

-Fred Shecter NAR 20117

Quote:

> Folks,
>    I am in the final stages of cloning a Starship Vega. It is your
> basic 9FNC4BT3L (nine fin, nose cone, 4 body tubes, 3 legs) rocket.
> It's a great looking rocket, but I haven't seen anything this bottom
> heavy since this girl I knew in high school. Will the large fin area
> give it all the stability it needs, or should I add plenty of nose
> weight?

> --Steve

> Sent via Deja.com http://www.deja.com/
> Before you buy.


 
 
 

Theories on Flight Stability and Big Honkin' Fins

Post by Jeff Brund » Sat, 04 Nov 2000 04:00:00


Steve,

As long as you are not deviating from the original design and your clone
is made from the same way and from the same materials as the original
then you should be fine. The orginal flew fine as designed so yours
should do the same.

If you have access to rocksim then you could draw it up on there and
verify. If you are in real doubt then add an ounce of weight to the NC,
that should help as well without drastically affecting flight
performance. the model is a drag pig already.

Quote:

> Folks,
>    I am in the final stages of cloning a Starship Vega. It is your
> basic 9FNC4BT3L (nine fin, nose cone, 4 body tubes, 3 legs) rocket.
> It's a great looking rocket, but I haven't seen anything this bottom
> heavy since this girl I knew in high school. Will the large fin area
> give it all the stability it needs, or should I add plenty of nose
> weight?

> --Steve

> Sent via Deja.com http://www.deja.com/
> Before you buy.

 
 
 

Theories on Flight Stability and Big Honkin' Fins

Post by James Steven Yo » Sun, 05 Nov 2000 12:48:39


If you build it stock, it should be fine.  Lots of fin area back
there.  The forward fins cancel some of it out, but it flies just
fine.  I assume you're talking about the original, and not the Super
Vega.  I also assume, from the sound of it, you're building the later
version, with flat caps on the fin pods.  The earlier version used
balsa cones on the pods, and was probably, if anything, more tail
heavy.  Again, that version was a great flier.

Quote:

>Folks,
>   I am in the final stages of cloning a Starship Vega. It is your
>basic 9FNC4BT3L (nine fin, nose cone, 4 body tubes, 3 legs) rocket.
>It's a great looking rocket, but I haven't seen anything this bottom
>heavy since this girl I knew in high school. Will the large fin area
>give it all the stability it needs, or should I add plenty of nose
>weight?

>--Steve

>Sent via Deja.com http://www.deja.com/
>Before you buy.

J. Steven York - www.sff.net/people/j-steven-york - Writer
Generation X Novels: Crossroads, Genogoths
Bolo, The Old Guard (Jan. 2001, Baen Books)
 
 
 

Theories on Flight Stability and Big Honkin' Fins

Post by Peter Cl » Sun, 05 Nov 2000 16:50:48


Quote:
>Starship Vega. It is your
>basic 9FNC4BT3L (nine fin, nose cone, 4 body tubes, 3 legs) rocket.

Fantasy/Sci-Fi writer J. Steven York brought one of these to the first HPR
launch I ever attended. Pictures at
http://hometown.aol.com/peterlynnc/tdvii.html .
Peter W. Clay NAR 18619 SR L1 OREO 555
If it dies, it's biology; if it blows up, it's chemistry; if it breaks, it's
physics.
 
 
 

Theories on Flight Stability and Big Honkin' Fins

Post by James Steven Yo » Sun, 05 Nov 2000 04:00:00


Actually, that was the Super Vega, Estes Bt-60 (with BT-50 pods)
upscale of the original (BT-50, with BT-5 pods) Vega.  I've owned and
flown both.  I've still got a nose cone from my first Vega here, and
I'll use it to build another someday.


Quote:
>>Starship Vega. It is your
>>basic 9FNC4BT3L (nine fin, nose cone, 4 body tubes, 3 legs) rocket.

>Fantasy/Sci-Fi writer J. Steven York brought one of these to the first HPR
>launch I ever attended. Pictures at
>http://hometown.aol.com/peterlynnc/tdvii.html .
>Peter W. Clay NAR 18619 SR L1 OREO 555
>If it dies, it's biology; if it blows up, it's chemistry; if it breaks, it's
>physics.

J. Steven York - www.sff.net/people/j-steven-york - Writer
Generation X Novels: Crossroads, Genogoths
Bolo, The Old Guard (Jan. 2001, Baen Books)
 
 
 

Theories on Flight Stability and Big Honkin' Fins

Post by Dave Pachec » Sun, 05 Nov 2000 04:00:00


Quote:

> 9FNC4BT3L (nine fin, nose cone, 4 body tubes, 3 legs) rocket.

Sorry I don't know about your question but....

I didn't realize we started writing rockest as chemical formulas :)

I'll write the first Periodic Table of the Components
A  Altimeter
Nc Nose Cone
F  Fin
Bt Body tube
Pb Payload Bay (made of lead)
Sc Shock Cord
P  Parachute
S  Streamer
Fw Featherweigth Recovery

Anythign else?

--
Dave Pacheco
ICQ: 6568274            http://modelrockets.8m.com/home.html
NAR#: 77711             G.Y.R.O. #135

"Facts, shmacts. You can use facts to prove anything that's even remotely true!
                                --Homer Simpson