NAR Testing Issues?

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rharshberger said:
ITS A JOKE! I for one want to have fun here, and as such am attacking no individuals (well at least not recently, all the ones that deserved it were banned long ago).
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Hey! I'm still here, but probably deserve whatever the universe throws at me :-D
 
This is pretty simple. I'll run everyones motors through a standard rocket and they can base all the info off that. no more thrust curves....pesky N numbers.

They all just get a "dave flew it to XXXX'" rating. nice and easy
 
rharshberger said:
ITS A JOKE! I for one want to have fun here, and as such am attacking no individuals (well at least not recently, all the ones that deserved it were banned long ago).
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Fair enough, but I took it personally, and hoped that was not the case.

Apologies too, but the only thing I really care about is how much effort it takes to maintain what's left of me.
A suggestion of me not getting any exercise other than running my mouth on an internet forum really hits to the bone.
 
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TopRamen said:
Fair enough, but I took it personally, and hoped that was not the case.

Apologies too, but the only thing I really care about is how much effort it takes to maintain what's left of me.
A suggestion of me not getting any exercise other than running my mouth on an internet forum really hits to the bone.
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I'm absolutely guilty of this way way too often - - But don't let the internet offend you..... A couple posts in this thread have taken chips outta you. This all exists for fun, and this thread went off the rails long ago. Don't take it too seriously.... and something I've realized recently.... is sometimes you have to just get up and walk away from it.
 
DizWolf said:
I'm absolutely guilty of this way way too often - - But don't let the internet offend you..... A couple posts in this thread have taken chips outta you. This all exists for fun, and this thread went off the rails long ago. Don't take it too seriously.... and something I've realized recently.... is sometimes you have to just get up and walk away from it.
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Gotta know when to hold'em, and you gotta know when to fold'em.....(I dont gamble). :)
 
Whatever happened, it appears that RCS is using it as justification for an attempt to push through an "emergency" change to the certification requirements in NFPA 1125. The change would let a manufacturer sell their motors after delivering data to the AHJ/ testing organization. Their approval isn't required.

https://www.nfpa.org/codes-and-stan...nd-standards?mode=code&code=1125&tab=editions

I don't trust any manufacturer that far.

The NFPA is accepting comments from anyone until 21 October.
 
Hmm... the cold war is escalating ? I've asked the NAR S&T chairs (via email) for their comment on this proposal.
 
I saw the email and forwarded it on to the NAR NFPA 1125 committee member.

There are no new motors waiting for testing, nor have any been received in the last couple months.

That's all I can say at the moment.


John
 
Johnly said:
I saw the email and forwarded it on to the NAR NFPA 1125 committee member.

There are no new motors waiting for testing, nor have any been received in the last couple months.

That's all I can say at the moment.


John
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Thanks. Just a strange little tempest in a teapot I hope.
 
UhClem said:
Whatever happened, it appears that RCS is using it as justification for an attempt to push through an "emergency" change to the certification requirements in NFPA 1125. The change would let a manufacturer sell their motors after delivering data to the AHJ/ testing organization. Their approval isn't required.

https://www.nfpa.org/codes-and-stan...nd-standards?mode=code&code=1125&tab=editions

I don't trust any manufacturer that far.

The NFPA is accepting comments from anyone until 21 October.
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Why not trust the manufacture? They have nothing to gain by selling a motor that doesn't work as advertised.
 
markkoelsch said:
Why not? There is some history of manufacturers over rating their motors. Not current manufacturers mind you.
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How about allow self testing and a single verification burn from third party. Allow the manufacture to certify the motor is x, start selling to the public, and allow tmt/nar to verify it when they can fit it in.
 
There has been a good number of motors over the years that seems like the flyers are doing the testing. Other wise how do some motors get out of testing and have problems show up once out in the field. I just feel some times us flyers are TMT or NAR motor testing.
 
crossfire said:
There has been a good number of motors over the years that seems like the flyers are doing the testing. Other wise how do some motors get out of testing and have problems show up once out in the field. I just feel some times us flyers are TMT or NAR motor testing.
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Gary, I think there is a difference between a test stand and a flight. Acceleration forces can cause issue you would never see on a stand.

You and I both have been bitten by such things- first day of MWP last fall.
 
markkoelsch said:
Why not? There is some history of manufacturers over rating their motors. Not current manufacturers mind you.
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Like a G motor with 83 N-s, or an H with 163? Seems like sample variation would be enough to de-rate them...

I think everybody plays that game. That's why I like the CTI rating system... total impulse up front, letter rating secondary.
 
Why? It isn't difficult to find the complete specifications for other motors. Especially using a sim program. I wouldn't think of using a motor I hadn't simulated. Peak acceleration, maximum velocity, velocity off the rod/rail, etc., should be factors in the design/build decisions. It doesn't matter what your goals are for any given rocket, but you should have some idea of what the flight profile will look like before even starting the build. I've built stronger than I would otherwise for short burn motors, but wouldn't consider it appropriate to stuff one into a rocket designed specifically for a different thrust profile.

cerving said:
Like a G motor with 83 N-s, or an H with 163? Seems like sample variation would be enough to de-rate them...

I think everybody plays that game. That's why I like the CTI rating system... total impulse up front, letter rating secondary.
Click to expand...
 
cerving said:
Like a G motor with 83 N-s, or an H with 163? Seems like sample variation would be enough to de-rate them...

I think everybody plays that game. That's why I like the CTI rating system... total impulse up front, letter rating secondary.
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I too like the the CTI method of motor identification

I was not talking that type of de- rating.

I was talking a manufacturer saying a motor was a J1500 when it was really a J875 or J975. So far off as to be way outside the realm of normal motor variation.
 
Just to stir up a hornet's nest, did this ever officially get resolved?
 
Self certifying is nothing new in industry. The CE mark is done that way. But you still need to have documented calibration data for any test equipment used and have documented test processes. That would be the minimum any motor manufacturer would need to be able to self certify.
 
falingtrea said:
Self certifying is nothing new in industry. The CE mark is done that way.
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From what I read, that only applies to products with minimal risk. I don't think that rocket motors would qualify.
 
My knowledge on CE ratings is pretty latent and I never delt in pyro and the like but I was under the impression that explosives had to be tested by a notifed body (approved lab). However the certs done by NAR/TRA are at best a subset of CE.
 
rstaff3 said:
My knowledge on CE ratings is pretty latent and I never delt in pyro and the like but I was under the impression that explosives had to be tested by a notifed body (approved lab). However the certs done by NAR/TRA are at best a subset of CE.
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No.

NAR S&T, TRA TMT and CAR MTC are simply recognized certifying authorities. We are disinterested third parties who witness a small number of manufacturer supplied hobby rocket motors motors in operation to make sure they meet the manufacturer's supplied specifications when operated according to the manufacturers directions.

The manufacture supplies a certain number of motors as specified in NFPA 1125, and their specifications. The testing organizations assemble and operate the motors on an instrumented test stand and observe the motor burn and collect the test data and compare what was obtained on the test stand to what is required under NFPA 1125 for the manufacture's motors to meet their own specifications. If the motors perform as the manufacturer specifies, they pass certification testing. If they perform outside the manufacturers own specifications, or one catos, they do not pass certification testing.

It's really that simple.
 
bobkrech said:
If they perform outside the manufacturers own specifications, or one catos, they do not pass certification testing.
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Without naming manufacturers, how often does this happen? Do you get any failures in a given year?
 
bobkrech said:
No.

NAR S&T, TRA TMT and CAR MTC are simply recognized certifying authorities. We are disinterested third parties who witness a small number of manufacturer supplied hobby rocket motors motors in operation to make sure they meet the manufacturer's supplied specifications when operated according to the manufacturers directions.

The manufacture supplies a certain number of motors as specified in NFPA 1125, and their specifications. The testing organizations assemble and operate the motors on an instrumented test stand and observe the motor burn and collect the test data and compare what was obtained on the test stand to what is required under NFPA 1125 for the manufacture's motors to meet their own specifications. If the motors perform as the manufacturer specifies, they pass certification testing. If they perform outside the specified specifications, or one catos, they do not pass certification.

It's really that simple.
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Yes, I understand all that but I obviously wasn't clear. What you responded to was not what I was getting at. Which was that I didn't think you could self-certify motors.

If you CE a motor, do they test the characteristics of the raw propellant only? Do they verify the motor works? Do they run the thrust curves? But my understanding was that 'they' had to be a notified body (approved testing lab) as opposed to the self declaration you can do on some CE stuff. To do self certification say on electronics you test to the CE specs. That often involves a US lab that doesn't have to be approved by the EU folks.

So, if you don't have to use a notified body and you need the thrust curves, you might be able to use NAR or TRA motor cert docs for that part for the testing.
 
djs said:
Without naming manufacturers, how often does this happen? Do you get any failures in a given year?
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We do not comment on failures.

rstaff3 said:
Yes, I understand all that but I obviously wasn't clear. What you responded to was not what I was getting at. Which was that I didn't think you could self-certify motors.

If you CE a motor, do they test the characteristics of the raw propellant only? Do they verify the motor works? Do they run the thrust curves? But my understanding was that 'they' had to be a notified body (approved testing lab) as opposed to the self declaration you can do on some CE stuff. To do self certification say on electronics you test to the CE specs. That often involves a US lab that doesn't have to be approved by the EU folks.

So, if you don't have to use a notified body and you need the thrust curves, you might be able to use NAR or TRA motor cert docs for that part for the testing.
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CE is really a set of EU import/export requirements. You can't sell most products in the EU without a CE certification. CE testing can be done in a number of ways by various organizations but has little to do with hobby rocketry certification.

Regardless of country of origin. Any solid rocket motor is classified as a Class 1 Hazmat. The solid propellant must be submitted to a government certified explosives testing laboratory for independent material classification testing before it can be shipped in-commerce world-wide. This has nothing to do with hobby rocket certification testing.

In the US you do not need an explosives license for APCP hobby rocket motors. In many countries, you need the equivalent of an explosives license for motors above a certain size. This is a legal requirement and really does not have any bearing on the hobby rocket motor certification process.

In the US, in almost every state, the NFPA 1 Fire Code has been adopted. In these states, hobby rocket motors must be certified under NFPA 1125 testing procedures by an independent third party other than the manufacturer. The accepted certifying authorities are: NAR S&T, TRA TMT, CAR MTC and UKRA.

https://www.nar.org/find-a-local-club/section-guidebook/laws-regulations/
 

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