Nose cone to body tube security?

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Senior Space Cadet

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There is only the tiniest of lips keeping the nose cone from being pushed into the body tube.
Is there any chance of this happening, on liftoff, with a heavy nose cone and an E motor?
If so, what are common methods of preventing this?
 

OverTheTop

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You can estimate the amount of force by using a simulator program to give you the maximum acceleration expected during the flight, and then multiplying the mass of the NC by this number. That will give you the equlvalent mass when it is under maximum acceleration.

You will be surprised by how strong the body tubes actually are. You can strengthen them by smearing on some cyanoacrylate adhesive (superglue) around the inside end of the tube. It soaks in and toughens it up a bit. Probably not necessary for the reason you are asking. It does however make the end of the tube less susceptible to zippering at deployment.

FYI I have never had a tube fail as per your question.
 

dhbarr

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Liftoff never, landing only when the chute is lazy :cool:
 

neil_w

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There is only the tiniest of lips keeping the nose cone from being pushed into the body tube.
Is there any chance of this happening, on liftoff, with a heavy nose cone and an E motor?
If so, what are common methods of preventing this?
You do not need to worry about this.
 

crossfire

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Never seen it happen on the way up. Coming down forsure when it hits hard nose down
 

dr wogz

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Unless you have an obscene amount of instant force and a massively heavy NC, this ain't gonna happen. Paper is stronger than you think it is..

Senior, you seem to be overthinking a lot of this, then jumping to conclusions based on your personal life experiences. (you then try to challenge some of us despite the experience & knowledge we have & are trying to impart to you)
  • Stop. slow down.
  • Stop trying to learn all this in a week-end.
  • Get & read Harry Stine's book: Handbook of Model rocketry. (this alone will answer a lot for you!) Also get the few new books on High power rocketry.
  • Get a few kits & build them, buy a few from different vendors / manufacturers. See what each does, what they do differently, what they do the same. Doing this alone will teach you a great deal.
  • launch these! You should soon be able to predict their flight, delay required, estimated altitude, speed, etc.. (Most kits will tell you most of this on the kit face-card)
  • Join a club, start looking at what others have done. Start asking them why they did what they did..
  • Only then can you start to get an understanding of why things are they way they are, why they work the way they do, and most of all (in your case) why the funky space age science fiction rocket flies higher than the plain ole Patriot kit (or visa versa)
 

Senior Space Cadet

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You can estimate the amount of force by using a simulator program to give you the maximum acceleration expected during the flight, and then multiplying the mass of the NC by this number. That will give you the equlvalent mass when it is under maximum acceleration.

You will be surprised by how strong the body tubes actually are. You can strengthen them by smearing on some cyanoacrylate adhesive (superglue) around the inside end of the tube. It soaks in and toughens it up a bit. Probably not necessary for the reason you are asking. It does however make the end of the tube less susceptible to zippering at deployment.

FYI I have never had a tube fail as per your question.
I was thinking about doing that to prevent zippering, anyway. Now I know it's a good plan.
 

Senior Space Cadet

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OK, I won't stop worrying till I go for Mach 1, which is probably never, and by then I'll be using fiberglass.
 

Not Quite Nominal

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You'll buckle the unsupported part of the BT below the NC shoulder long before you shove the NC down the BT.

The weakest link here. is the unsupported BT.
 

Alan15578

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There is only the tiniest of lips keeping the nose cone from being pushed into the body tube.
Is there any chance of this happening, on liftoff, with a heavy nose cone and an E motor?
If so, what are common methods of preventing this?
That reminds me of the Lovelace effect.
In any event many nose cone shoulders are very short and depend on friction to function correctly.
 

jrap330

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Unless you have an obscene amount of instant force and a massively heavy NC, this ain't gonna happen. Paper is stronger than you think it is..

Senior, you seem to be overthinking a lot of this, then jumping to conclusions based on your personal life experiences. (you then try to challenge some of us despite the experience & knowledge we have & are trying to impart to you)
  • Stop. slow down.
  • Stop trying to learn all this in a week-end.
  • Get & read Harry Stine's book: Handbook of Model rocketry. (this alone will answer a lot for you!) Also get the few new books on High power rocketry.
  • Get a few kits & build them, buy a few from different vendors / manufacturers. See what each does, what they do differently, what they do the same. Doing this alone will teach you a great deal.
  • launch these! You should soon be able to predict their flight, delay required, estimated altitude, speed, etc.. (Most kits will tell you most of this on the kit face-card)
  • Join a club, start looking at what others have done. Start asking them why they did what they did..
  • Only then can you start to get an understanding of why things are they way they are, why they work the way they do, and most of all (in your case) why the funky space age science fiction rocket flies higher than the plain ole Patriot kit (or visa versa)
Concur, I have stated the same thing. Which is why everyone should build a few kits.
 
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