aluminum?

[wergugy]

is it possible to make an aluminum rocket and will it fly? i have the tools (a lathe) so thats not a problem.

 

[Gillard]

is it possible to make an aluminum rocket and will it fly? i have the tools (a lathe) so thats not a problem.

The safety code we fly by pretty much rules out making/flying a rocket out of metal.

 

[ScrapDaddy]

Don't HPR rockets use metal fin cans and retainers, and reload casings?

 

[Gillard]

from the safety code.

MATERIALS: My model rocket will be made of lightweight materials such as paper, wood, rubber, and plastic suitable for the power used and the performance of my model rocket. I will not use any metal for the nose cone, body, or fins of a model rocket.

 

[GRIFFIN]

Don't HPR rockets use metal fin cans and retainers, and reload casings?

"A high power rocket may be constructed of paper,wood, fiberglass or plastic with a MINIMUMamount of metalic parts"

From theTripoli safety code per NFPA 1127

 

[ScrapDaddy]

Thats quite a gray line..... But does the NAR code mention anything about that?

 

[MarkII]

Thats quite a gray line..... But does the NAR code mention anything about that?

Your question has already been answered. See Gillard's post above. Also visit the NAR website for more information.

https://www.nar.org/

I strongly suggest that both ScrapDaddy and wergugy obtain and read "The Handbook of Model Rocketry, 7th edition" by GH Stine and Bill Stine. It will give you a very good grounding in the background, methods and practices involved in the hobby, and it can answer a very great number of questions. I have been active in this hobby for some 10 years total, and I still consult the Handbook quite frequently.

Mark K.

 

[UPscaler]

"A high power rocket may be constructed of paper,wood, fiberglass or plastic with a MINIMUMamount of metalic parts"

From theTripoli safety code per NFPA 1127

So does that mean those fancy new aluminum fin cans can only be flown at TRA launches? :neener:

 

[MarkII]

So does that mean those fancy new aluminum fin cans can only be flown at TRA launches? :neener:

Gillard was quoting from the TRA High Power Safety Code, I believe. A small amount of metal can be used in high power rockets if it is necessary for structural integrity. How much metal do you think is actually in an average HPR? Metal airframes are completely forbidden.

There is no daylight between the NAR and TRA High Power Safety Codes. Both are based on NFPA 1127.

Mark K.

 

[TheAviator]

So does that mean those fancy new aluminum fin cans can only be flown at TRA launches? :neener:

No, as they were quoting the Model Rocket Safety Code. However, the NAR HPR Safety Code has a similar stipulation for a MINIMUM of metal.

2. 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.

Most times there is absolutely no need for aluminum. Search around the site, you'll see machbusters in the Ma >= 2.0 that still don't use metal for structural purposes.

 

[ScrapDaddy]

And anyway metal gets really heavy thats where carbon fiber and fiberglass comes in

 

[ScrapDaddy]

Could you imagine if an airline pilot was flying and paniced because he saw a metal blip coming twords him on his radar screen? :y:

 

[cjl]

Metal airframes are completely forbidden.

Are you sure? I know many BALLS projects use aluminum almost exclusively, including for the airframe.

 

[GregGleason]

is it possible to make an aluminum rocket and will it fly? ...

My assumption is that you would like the airframe to be aluminum, with a possibility of the fins and nose cone as well.

I will answer this two ways:

Can you?
Yes. You can make gold fly, if you have enough thrust and a design that meets the basic criteria of rocket flight.

Should you?
No. Many of us belong to clubs and want the hobby to continue with as little "outside" influence as possible. Part of it "continuing" is people being responsible. Lightweight materials keep the mass down, so if a rocket comes in ballistic it is less likely to cause damage to personnel or property. Where damages exist, so do lawyers and lawmakers. Has anyone seen what has happened to Toyota in the media recently?

We fly according to codes that keep risks to a minimum while preserving the fun we all enjoy. While AL has some nice properties for commercial aerospace applications, paper/cardboard is a great material. If you need something stronger go with laminates of fiberglass, carbon fiber, or Kevlar. Obviously we do use some metal in rocketry, but it minimized to only those areas where it is really needed, like motor cases and closures, motor retention, eyebolts, U-bolts, etc.

Rocketry is a great hobby with a lot of great people. And it one that we all hope to pass along to the next generation.

:2:

Greg

 

[MarkII]

Are you sure? I know many BALLS projects use aluminum almost exclusively, including for the airframe.

BALLS is a Tripoli research launch festival and it is conducted according to the Tripoli Research Code. It is NOT a normal high power launch. Quoting from the BALLS 19 website:

[FONT=Arial, Helvetica, sans-serif]BALLS 19 is a venue for projects that should NOT be flown publicly due to safety and legal restrictions. This may include, but is not limited to, LARGE rockets, complex staging or clustering, metal rockets, self designed and/or fabricated rocket motors and new technologies being developed or proven. [...] This launch will be primarily for Research Motors and/or Dangerous projects. Do NOT come to observe unless you are directly involved in flight activities, a Pre-Approved Experimental Project or invited by persons active in such ventures.[/FONT]

By definition, participants at BALLS demonstrate projects that do not strictly adhere to the Safety Code.

Mark K.

 

[TheAviator]

For some more constructive criticism, a random thought on aluminum and rockets. One of the more popular ways to build lightweight competition rockets is to make a mandrel (form) from turned aluminum and lay a layer of very light (.6-.75 oz/yd^2) fiberglass over it. The FG airframe then slides right off the mandrel (assuming you used enough mold release) and you clean and use it again. The international competitors do their duration models this way.

This obviously works better for smaller rockets when you're trying to keep a tight tolerance. People generally make molds for larger airframes out of mylar wrapped over a cardboard tube.

 

[Micromeister]

I use Lots of Alumimum, Stainless steel, and other metals...For ground support equipment and launchers.

As so many have already stated it's simply against all the safety codes. That Folks is the NUMBER ONE most important thing every single one of us MUST think about every single time we consider building a model, mid or high power rocket out of anything. THE SAFETY OF OTHERS.

Ask yourself the questions....What IF. If there is the slightest possiblilty of accident or injury to persons or property with what we're thinking about building the answer should alway be don't do it. Bullet proof models are as dangerous and aluminum rockets. Lets stop overbuilding as well. Build for flight NOT The crash regardless of thrust level.

 

[hardinlw]

Model rockets and high power rockets operate under two different sets of rules. With model rockets, there is no need to obtain an FAA waiver as there is with HPR. The model rocket, by virtue of light weight and a good set of operating rules is inherently safe and poses no appreciable risk to aircraft flying at normal altitudes. High power rockets which can go very high and carry considerable weight in a form that could do damage to an airplane require a waiver. Basically, the waiver gives the airspace to the rocket flyers and tells aircraft to stay away. By the rules, a model rocket cannot be constructed of aluminum but a HPR can. Do you really want to go to the hassle of an FAA waiver which will only be granted for places far from the airways?

 

[RoyAtl]

Model rockets and high power rockets operate under two different sets of rules. With model rockets, there is no need to obtain an FAA waiver as there is with HPR. The model rocket, by virtue of light weight and a good set of operating rules is inherently safe and poses no appreciable risk to aircraft flying at normal altitudes. High power rockets which can go very high and carry considerable weight in a form that could do damage to an airplane require a waiver. Basically, the waiver gives the airspace to the rocket flyers and tells aircraft to stay away. By the rules, a model rocket cannot be constructed of aluminum but a HPR can. Do you really want to go to the hassle of an FAA waiver which will only be granted for places far from the airways?

Good answer, except the FAA waiver does not "give the airspace to the rocket flyers". It merely allows them to be in the airspace. Others using the airspace are told about the waiver via Notice To Airmen or NOTAMs, allowing them to make adjustments as necessary. Most of the time, they avoid the area, but usually a waiver attracts at least one or two pilots to come by and see what's going on, which means we have to stand down while they're looking

 

[ben_ullman]

I use Lots of Alumimum, Stainless steel, and other metals...For ground support equipment and launchers.

As so many have already stated it's simply against all the safety codes. That Folks is the NUMBER ONE most important thing every single one of us MUST think about every single time we consider building a model, mid or high power rocket out of anything. THE SAFETY OF OTHERS.

Ask yourself the questions....What IF. If there is the slightest possiblilty of accident or injury to persons or property with what we're thinking about building the answer should alway be don't do it. Bullet proof models are as dangerous and aluminum rockets. Lets stop overbuilding as well. Build for flight NOT The crash regardless of thrust level.

And how many times have you applied this knowledge to large K on up projects?

Ben

 

[ben_ullman]

Good answer, except the FAA waiver does not "give the airspace to the rocket flyers". It merely allows them to be in the airspace. Others using the airspace are told about the waiver via Notice To Airmen or NOTAMs, allowing them to make adjustments as necessary. Most of the time, they avoid the area, but usually a waiver attracts at least one or two pilots to come by and see what's going on, which means we have to stand down while they're looking

Or in the case of some of the corn fields, it gives crop dusters notice to A) not fertilize the field we are on B) know we are in the area. Ran into that last weekend. There was a crop duster on the field next to us and we stood down and took care of some launch housekeeping things while waiting a few minutes.

Ben

 

[RoyAtl]

And how many times have you applied this knowledge to large K on up projects?

Ben

But Ben, generally we're not talking about K and up projects. It can certainly be argued that some large projects would actually be safer *and* lighter being made from ductile aluminum than from fiberglassed cardboard or even kevlar/carbon layups depending on the construction techniques used.

Micromeister's point stands up. Build (and fly) for safety, then for performance.

If you need more performance than your safety parameters can handle, you need to find a place where you can expand your safety parameters. I think they call that Black Rock

But, back to the original discussion, the trade-offs for model rockets *and* for most HPR should be skewed toward the model absorbing impact energy rather than transmitting it.

 

[cjl]

And how many times have you applied this knowledge to large K on up projects?

Ben

Micro is right here ben. Regardless of the rocket size, it should be strong enough to withstand flight stresses plus a safety margin (1.5x is typical in engineering for example), and no stronger. I've seen entirely too many projects that are built like a tank completely unnecessarily. I've seen rockets seemingly built such that if they came in ballistic, you could fly them again after digging them out with a backhoe, and to be perfectly honest, those ones scare me a bit. It's true that above a couple of pounds, rockets are going to cause serious damage if they come in ballistic, regardless of the weight, you'll get more performance on smaller motors if you don't overbuild.

I'm not saying high performance or big motors are bad by the way. Just that overbuilding is bad. If you're using 1/8" carbon plate for your fins (as I am on my L3) because your rocket is planned to go mach 2.5 on some of the motors it is capable of using, that's fine. If you're using 1/8" carbon plate because your rocket will be flying on an M motor, despite the fact that it's only ever going to reach mach 0.8, then it's almost definitely a poor choice. Use materials based on the flight profile planned and the required strength, not so it can survive a nuclear blast.

Oh, and believe me, I'm not saying not to use composites. Composites are often the best way to make a rocket. However, most people use far more composites than necessary, and as a result, their rockets weigh a ton compared to what they could, resulting in lower performance and larger (and more expensive) engines needed for flight.

 

[dave carver]

At one point Dr. Rocket had a modular rocket that you basically assembeled as you went along. The foreward enclosure was threaded for a payload bay to screw on, fins that fit in slots, graphite nosecone if I remember right. The TRA board had to come down and say the rocket was not legal for a 3rd level attempt, due to the fact there was no construction by the rocket's owner. Dr. Rocket had done it all.

This was a true minimum diameter 4" rocket and all metal.

 

[The EGE]

IIRC, they did let the doctor certify on it, though, because he did technically make it.

 

[troj]

All-aluminum rockets are indeed made for, and flown at BALLS. These are typically for very high-performance flights, where conventional rocketry materials are more difficult.

It's hard to justify aluminum airframe as "necessary" for a K motor flight that's going 10,000 feet.

In addition, many fields entirely ban aluminum nosecones and fin cans.

You'll have an uphill battle getting me to let you fly one at our field. But, I do understand their place in the world, and that place is typically for performance like many demonstrate at BALLS.

-Kevin

 

[MarkII]

Th BALLS annual launch is specifically for rockets that you cannot launch anywhere else, or at any other type of sanctioned launch. That's why it is done only once a year and only at Black Rock. (And also why the website for it is plastered with beaucoups warnings and advisories and why the launch is not open to the general public.) Saying that something is OK because it can be done at BALLS is kind of like saying that it is OK to shoot missiles with explosive warheads at ground targets because, after all, you did it when you were in the service.

Mark K.

 

[Pat_B]

And then there are bowling ball launching contests. Kind of makes the LP rules look rather silly.

 

[cjl]

And then there are bowling ball launching contests. Kind of makes the LP rules look rather silly.

I honestly don't understand the concern some people have over bowling ball launches. Yes, it's launching a large, heavy object, but I don't see why it would be any more dangerous than any other >15lb fiberglass rocket.

 

[ScrapDaddy]

Wait if the code HPR code only applyies to high power then in MPR (which it's borders have not permanently settled yet) aReopac retainers shouldbt be allowed