Why is metal not allowed to be used to make a rocket?

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FallsChurchTSA

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Disclaimer: I'm not planning on building a metallic rocket any time soon.

Well, it's just an odd question I've kinda had. NAR says no metal is allowed. Tripoli says "minimum amount of metallic parts" and that they have to be deductible metals (Aluminum & Copper alloys). Which is weird IMO cause doesn't aluminum and copper have very low melting points compared to steel or etc. Also, how is fiberglass able to withstand much higher melting points than aluminum or copper?

also part dumb but how were these guys in the vid below allowed to build with metal?
https://youtu.be/BJppeRWSD94
 

Titan II

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NAR and Tripoli do not regulate all rocket activities. There is a lot going on outside their purview.
 
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KennB

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Also, it's not about the melting point of the material. It's about the shrapnel produced if a rocket motor has a catastrophic failure at launch. Ductile metals will tear apart but will likely stay in large "chunks" that would lose velocity quickly between the launch pad and the crowd which is at the recommended safe distance away. Non-ductile metals and materials such as PVC will shatter into smaller fragments that can do more harm at greater distances.

When someone working outside the control of NAR and TRA makes a rocket, they will likely use metal because it's tough to beat for strength vs. weight and it is, generally, easy to work with. One hopes that all due caution is being exercised when the test and launch so, if something goes wrong, no one is going to get hurt.

I see this is your first post; welcome to TRF. If you're seriously interested in model rocketry and high-power rocketry, this is a great place to be.
 

Bat-mite

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Since it is an FAA requirement, probably has to do with punching holes in aircraft.
 

rstaff3

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I think it is more about punching holes in people and their property. This predated NFPA and probably, at least for modrocs, the FAA. I could be wrong.

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samb

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I few observations about the attached video:

- It was a TV show. That means they had a production budget, i.e. they used other peoples money and they were probably self-insured.

- It was a TV show. That means they had to include a certain amount of "dramatic jack-assery". Like trying their cluster motor ignition stunt. Filmed from way further back with alot of fire supression gear handy I'll bet.

- It was a TV show. You'll note that they flew their metal beastie at FAR in California, one place in the USA set up for it. Did you see the blockhouses ? And they paid for that privilege. And they signed liability waivers.

https://friendsofamateurrocketry.org/ for more information.


Hobby rockets built and flown according to NAR/Tripoli guidelines require relatively fewer regulations. This forum is a great place to learn more about hobby rocketry.
 

modeltrains

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2011-06-08 04:43:05 UTC #1

Got a call today from a woman who said she had a hole in her roof from a rocket. Ok, I'm outside and maybe she said a rock so I ask her again. She is quite serious that she has a rocket sticking through her roof. I'm thinking is this a prank so I bite and ask her what kind of rocket like a toy? She says no she thinks it is from space.

Ok, this merits a site visit from a salesmen ASAP. Sure enough he calls back and informs me there's a metallic rocket lodged in her roof and even sends me pics. We have a signed contract to remove the rocket tomorrow morning and seal up the roof.

WTF??? It's about 4-6 inches in diameter and maybe 4-6 feet long. I am thinking either military or failed science experiment. Certainly not a space ship. It's freaking sticking through the roof.

Sidewinder, Sparrow, IDK???? Anyone ever heard of anything like this????? I'll try to post pics tomorrow.....
https://talk.roofing.com/t/weirdest-roof-call-ever/6976
 

shreadvector

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The NAR does not say what you typed.

The NAR says this: https://www.nar.org/safety-information/model-rocket-safety-code/

"Materials. I will use only lightweight, non-metal parts for the nose, body, and fins of my rocket."

See the NFPA codes (1122, 1125, 1127) for more details.


Disclaimer: I'm not planning on building a metallic rocket any time soon.

Well, it's just an odd question I've kinda had. NAR says no metal is allowed. Tripoli says "minimum amount of metallic parts" and that they have to be deductible metals (Aluminum & Copper alloys). Which is weird IMO cause doesn't aluminum and copper have very low melting points compared to steel or etc. Also, how is fiberglass able to withstand much higher melting points than aluminum or copper?

also part dumb but how were these guys in the vid below allowed to build with metal?
https://youtu.be/BJppeRWSD94
 

modeltrains

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It is interesting. And somewhere on here I recall a report from a launch event where a wayward rocket, non-metallic, punctured someone's trailer roof.
May even have been another another report at one time where a rocket damaged an automobile.
 

Bat-mite

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It is interesting. And somewhere on here I recall a report from a launch event where a wayward rocket, non-metallic, punctured someone's trailer roof.
May even have been another another report at one time where a rocket damaged an automobile.
It was AMW-ProX's trailer and a pretty straightforward MPR.
 

Titan II

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The NAR does not say what you typed.

The NAR says this: https://www.nar.org/safety-information/model-rocket-safety-code/

"Materials. I will use only lightweight, non-metal parts for the nose, body, and fins of my rocket."

See the NFPA codes (1122, 1125, 1127) for more details.



That is the model rocket code. The NAR high power states:

Materials. I will use only lightweight materials such as paper, wood, rubber, plastic, fiberglass, or when necessary ductile metal, for the construction of my rocket.
 

dhbarr

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Turns out pointy things falling from on high is bad for other things; hence safety precautions about wind, launch angle, etc.
 

rstaff3

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It turns out a BT-60ish model with not enough thrust can embed itself in a person.
 

rstaff3

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Response confirming dhbarr's comment. Metal or pointy fiberglass would have been worse.

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FallsChurchTSA

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Thanks for all the replies. I'm slowly getting into rocketry and it's really fascinating to me and I'm even thinking about asking if my school can make a club for it.
 

stealth6

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I've explained this before, but will repeat....

It's not about metal or no metal; it's about the precise amount of metal. Too much or too little is problematic. So here is a handy guide:

THIS is far too little metal, and simply will not do:


THIS is a bit too much metal, is kinda scary, & requires a messy cleanup:


THIS is precisely the correct amount of metal, and will bring joy & happiness:


ssixsixsix
 

kclo4

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In Tripoli's version of the rules, metal(like was mentioned, mostly aluminum) can be used where appropriate, and that is generally defined as where necessary for the performance of a vehicle. Different clubs and RSO's define this different I think. A rocket at BALLS fixing to go mach 3.5 is given more allowances for metal parts than some Estes up-scaled kit that is only going to go 1000 feet.

Disclaimer: I'm not planning on building a metallic rocket any time soon.

Well, it's just an odd question I've kinda had. NAR says no metal is allowed. Tripoli says "minimum amount of metallic parts" and that they have to be deductible metals (Aluminum & Copper alloys). Which is weird IMO cause doesn't aluminum and copper have very low melting points compared to steel or etc. Also, how is fiberglass able to withstand much higher melting points than aluminum or copper?

also part dumb but how were these guys in the vid below allowed to build with metal?
https://youtu.be/BJppeRWSD94
 

MClark

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At BALLS rockets made entirely of aluminum are common.
Other launches under TRA rules allow no metal components.

M
 

Steve Shannon

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Disclaimer: I'm not planning on building a metallic rocket any time soon.

Well, it's just an odd question I've kinda had. NAR says no metal is allowed. Tripoli says "minimum amount of metallic parts" and that they have to be deductible metals (Aluminum & Copper alloys). Which is weird IMO cause doesn't aluminum and copper have very low melting points compared to steel or etc. Also, how is fiberglass able to withstand much higher melting points than aluminum or copper?

also part dumb but how were these guys in the vid below allowed to build with metal?
https://youtu.be/BJppeRWSD94
Unfortunately, none of what we do is deductible. [emoji6]

Unless you want to donate to one or the other organizations. We're both 501(c)3 non-profit.


Steve Shannon
 

Lowpuller

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MClark ALL TRA launches allow metal components, otherwise we would have no place to put our grains EX or commercial.
 

rstaff3

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The ban on metal is for the main structural components...cones, BT, fins, etc.
 

kclo4

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The ban on metal is for the main structural components...cones, BT, fins, etc.
But this wouldn't be an internet forum without nitpicking the verbage above recognizing the context.
 

MClark

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There is no, nor has there ever been, a TRA ban on metal airframe components.

I will disregard the comment on metal motor cases.

M
 

Igotnothing

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"Flying case" design has the aluminum motor as it's own airframe.

So there ya go. Minimum metal, and minimum anything else at the same time.
 

cerving

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Things falling out of the sky at a high rate of speed can do a lot of damage regardless of what they are made of. I saw that TV show too, and I immediately recognized that they had more than a little help from some of the FAR folks. Despite that, they still ended up with a crumpled heap of aluminum. The "down" part really needs to be the #1 priority... I thought it was funny that they called the flight a success. They could have accomplished the same thing with a much safer static test... of course, that wouldn't make "good" TV, would it?
 
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