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Nose weight question

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Vicious

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I built a Zenith II and it flew perfectly as a single stage rocket, when I flew as a 2 stage it took off at about a 50 degree angle and is now in a big tree across the road from the park. I'm assuming that the added weight of the booster section required me to add nose weight to make it right (I didn't add any weight). My question is, if I add enough nose weight to make a 2 or 3 stage rocket fly right with the booster/boosters how will the added nose weight affect it's fight as a single stage after the boosters are gone? Is it ok to be nose heavy but not tail heavy? I'm almost done with my Comanche-3 but I'm a little afraid to fly it because I don't want to lose it.

Thanks, Butch

I just realized I put this in the midpower section, I should have put it in lowpower, sorry :(
 

powderburner

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Your rocket has to be stable when extra stages are attached (duh). So it just might end up a bit over-stable when flying only the upper stage. It will still work, but it may not be one that you fly often on windy days.
 

LarryH

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One soloution might be to use removable weighted plugs, you could probably make these by gluing the appropriate size lead weight(fishing sinker, buckshot or whatever ya got) to a rubber stopper plug that will just plug the hole in the base of the nosecone.... this wouldn't help you with your two stage problem, but it might help when you wanted to launch on only one stage, or with a heavier/lighter motor, or to offset your payload.... etc.
 

jflis

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What I've done with some multi state to solve this problem is to come up with a short payload bay the same diameter as the sustainer body tube.

I would design the rocket such that it is stable as a single stager with no payload section. In 2-stage mode, I would pop off the nose and put the payload bay on (only about 1/5" long) and replace the nose. For 3 stage mode I would use a different payload bay with more weight on it.

worked great other than having to keep track of the different payload bays. WOuld also be easy to just make up the short payload bay to take several different weights and just change that.

jim
 

wwattles

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I'm working on an idea to use self-adhesive velcro strips on the inside of a plastic nose cone, with the other half of the velcro attached to some lead strip weights I got from my local hobby store. I'll be flying it on Feb 6th to see if it holds the against the thrust of 4 E's.

WW
 

corpse

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i think he was asking .
if i add wight for 3 stages to fly right
will it fly on 2 stages ,
and on 1 stage will it still fly right ?


how do i make it fly after ALL the stages fall off . ?

i think thats what he was asking
 

powderburner

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If it has the proper stability margin with all stages in place, it should fly fine without weathercocking.

When the first stage pops, it might have a larger stability margin, or it might not. Keep in mind that you lose the weight of the booster stage at the back end, but you also lose the fin area of that booster. After staging it will also have a much greater velocity, so the potential weathercocking effects of any cross-winds would be reduced.

Any ballast that you add to assure stability (whether for the upper stage alone, or with the second stage attached, or with all stages) is, of course, going to reduce the performance and give you a slightly lower altitude. But the Commanche is a 'sport' rocket, not a competition rocket, and a little lost altitude (if any) will not hurt.

Or did I miss the point of your question?
 

Stymye

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Butch,
It should fly ok without extra noseweight.

but you could add a small amount of noseweight to the upper stage
as long as it still flys well as a single stage.
mine flys straight without any extra weight

also dont think about it being nose or tail heavy....
pay more attention to where the center of gravity is
in relation to the center of pressure.
that will determine if you need weight ,and where
 

slim_t

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Originally posted by Vicious
My question is, if I add enough nose weight to make a 2 or 3 stage rocket fly right with the booster/boosters how will the added nose weight affect it's fight as a single stage after the boosters are gone?
If it will fly stable as a single stage before the weight, then adding weight will only make it overstable. This is not necessarily a bad thing. You'll lose a bit of altitude, and it will still fly stable, but will be more susceptable to be influenced by the wind.
But you don't want to be flying stagers in the wind anyway.

Did you build the Zenith by the instructions? I have one still in the bag, and I'd like to not have this problem. Was there any mention of nose weight?

If you ever get it back, see if there's something else that could've caused the problem.

Tim
 

Vicious

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Originally posted by powderburner

Or did I miss the point of your question?


You answered my question perfectly, thank you.
 

Vicious

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Slim_t,

I actually didn't use the red payload bay, it didn't even occur to me until another member here brought it up in another thread. Doh!!! I actually shortened it by about 2 inches, it flew great as a single stage on a C6-5, but with the booster was a whole 'nuther story. Live and learn!


Thanks, Butch
 

slim_t

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Originally posted by Vicious
I actually didn't use the red payload bay. Doh!!! I actually shortened it by about 2 inches. Live and learn!
Thanks. I might have done the same thing, since I don't really see a need for the payload bay. Amazing the difference a couple of inches can make. :rolleyes:

Tim
 
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