EX motors

[rockets]

I have some questions regarding "EX" motors. Are minors are allowed to make EX motors, even under adult or mentor supervision?
I have chunks of propellant from reloads; you guys know where when after you fly an reload, where there's sometimes chunks of un-burnt propellant? Well, is it possible to put those chunks together into a motor?
And last but not least, what's the easiest, safest and best motor type for beginners; Sugar, AP, or something else?

Maybe this needs to be something for me to wait a few more years on, but I was just curious if I can do this now, or in the next year or two, or if I should wait 5 or so years.

Thanks,

 

[rockets]

I've done research for a tad over a year.
Came up with these:
https://www.rocketmotorparts.com/29...tor_Kit-_Phenolic_Liner/p1577809_9654709.aspx
https://www.rocketmotorparts.com/29...Experimental_Motor_Kit/p1577809_15297068.aspx
https://www.rocketmotorparts.com/29..._Motor_Kit-Core_Burning/p1577809_7833146.aspx
Is this premade propellant? https://www.rocketmotorparts.com/29mm_White_Lightning__Propellant_Grain/p1577809_11308659.aspx
__________
I was also wondering if I should start with some LMS motors?

If you guys think this is a terrible & dangerous idea, let me know. I don't want to do anything stupid or dangerous.
Thanks,

 

[cavecentral]

Flying ex motors at a Tripoli launch requires you to be a level 2. I think you must be over 18 for a level 2.

 

[rockets]

Flying ex motors at a Tripoli launch requires you to be a level 2. I think you must be over 18 for a level 2.

Yeah, I think so. But I wonder what the rules are for TMP fliers. EDIT: I checked the safety code for TRA and it doesn't say anything about TMP fliers making research motors.

Thanks,

 

[djs]

I have chunks of propellant from reloads; you guys know where when after you fly an reload, where there's sometimes chunks of un-burnt propellant? Well, is it possible to put those chunks together into a motor?

Definitely don't do this. Nothing good will happen from this, and most likely, bad things will happen. If they really are unburnt chunks of propellant, they should be disposed of.

For EX motors, there's two things here:
1. Making EX motors
2. Flying EX motors

Tripoli is really only concerned with #2.. You'll have to be an L2 to fly a motor. I don't think they will allow any way around this.

As far as #1.. there are some dangers inherent to making motors that aren't obvious up front. Honestly, if I were you, I wouldn't even attempt this until you're older.

 

[DavidMcCann]

I'd recommend getting a 29/180 case, and flying it as much as possible.

Build a foundation of knowledge and understanding based on experience before into deeper topics.

I inderstnad tour your excitement and enthusiasm. But the best thing to do is fly some rockets.

 

[sharkbait]

Andrew,

I am impressed with your interest level and your aspirations into the rocketry hobby.

The way I read it, your TMP mentor is the flyer of record and the TMP rules state that the mentor may fly any motor that he may purchase and/or posess. So if your mentor is over 18 and a level 2 flyer, then I would say yes, you could fly an EX motor with your mentor as the flyer of record under the TM program.

That all said, the world of safely making EX motors is quite complex and dangerous. A large portion of the materials used in making propellant are extremely flammable, highly toxic, and can react very badly with each other if proper procedures are not very carefully followed. I would highly suggest that you wait a few more years and mentor with a seasoned EX flyer before ever thinking of trying this on your own. Keep up the enthusiasm and work on honing your skills in building, recovery, and electronics, and most of all get out and enjoy flying.

 

[Steve Shannon]

Andrew,
You've received some very good advice in the most recent posts, including djs, David McCann, and Sharkbait. Please listen to it. I understand what it's like to be so eager to learn, yet to be held back, but there's a lot to learn about rocketry that you are allowed to do right now. There's staging, electronic deployment, clustering, rocketry videos, high power construction techniques (composite construction), etc. In the mean time study chemistry, algebra, and geometry, in school. You'll need those if you want to truly understand making propellant and not just mixing ingredients following a recipe. You can even begin learning the theory behind making motors while you're under 18 and be ready to start on the practical subjects as soon as you turn Level 2.


Steve Shannon

 

[dhbarr]

Andrew,
You've received some very good advice in the most recent posts, including djs, David McCann, and Sharkbait. Please listen to it. I understand what it's like to be so eager to learn, yet to be held back, but there's a lot to learn about rocketry that you are allowed to do right now. There's staging, electronic deployment, clustering, rocketry videos, high power construction techniques (composite construction), etc. In the mean time study chemistry, algebra, and geometry, in school. You'll need those if you want to truly understand making propellant and not just mixing ingredients following a recipe. You can even begin learning the theory behind making motors while you're under 18 and be ready to start on the practical subjects as soon as you turn Level 2.


Steve Shannon

+1!

Fly MMX through ( with your mentor ) i600r... singly, clustered, staged. Understand and comprehend the length, the width, the depth, and the breadth of the FAR101 "limits".

You will neither be sorry, nor will you miss out when attending these launches. You will gain both wisdom and friends.

 

[djs]

+1 for I600R. Great reload in one of my favorite case sizes (AT 38/720). Flew an I327DM last weekend in my turkey rocket on that case.

 

[rockets]

Special thanks to all of you for the great tips!! I will use those wisely, and wait to mix some AP up until I'm old enough.
I think it's so fun building & flying rockets, and I seem to always want to launch the biggest motors possible. EX kinda stuck out to me, and I though maybe I could try it. Anyway, Hoping that this fall I can fly some small H motors and get used to it.

Thanks,

 

[0011001100]

Special thanks to all of you for the great tips!! I will use those wisely, and wait to mix some AP up until I'm old enough.
I think it's so fun building & flying rockets, and I seem to always want to launch the biggest motors possible. EX kinda stuck out to me, and I though maybe I could try it. Anyway, Hoping that this fall I can fly some small H motors and get used to it.

Thanks,

From a formerly ambitious kid:
WAIT
I've tried things and wasted lots of money because I pushed the limits too far. Now I've got more knowledge from calculus to chemistry and physics so I have better under standing of what I am doing and now I look back and realize how stupid I was and If i could have just saved the grand i spent on a failed two stage rocket then I could build one now for cheaper and actually work. I understand it's hard to wait but you need to learn what you are doing. Always listen to what your mentors have to say and always have multiple. I've been taking advice from some who have been doing this longer than I have been alive. For example one of my mentors has been with Tripoli for 25 years yet I'm only 17. I've built my level 2 so I've started the path into research and you have to be extremely careful because one wrong move could put you in the hospital. My suggestion is to wait till you understand the math behind it before you start making your own motors. I have enough knowledge of chemistry to write out the math for my motors using the names of the chemicals and that's it. Even then I'm still asking tons of questions and doing hours of research so I don't hurt myself. I also am starting out with small mixes so that it is easier to contain if something goes wrong.

Trevor Mushung

 

[3stoogesrocketry]

I have chunks of propellant from reloads; you guys know where when after you fly an reload, where there's sometimes chunks of un-burnt propellant? Well, is it possible to put those chunks together into a motor?


What exactly are you talking about ? Where are the unburnt chunks of propellent ? Would you be able to post a picture of what you have ? Unless the motor Cato's , there should not be any unburt chunks of propellent left over . If you get propellent from a catoed motor , do not fly it or even attempt to fly it . The grain(s) will most likely have micro fractures thruout the grain . Also the casting tube may be compromised , leading to a Cato . Please be safe . You have a huge future in this hobby .

Eric

 

[jimzcatz]

I have been in Tripoli over 25 years. I have never ever heard of nor seen any "unburnt propellant leftovers" when disassembling a motor. Am I missing something here. Andrew, if I was a mentor, I would have no problem including you in the research process. But you would have to be there at the mixing. If you came to me with a motor you mixed alone, not happening. Good luck in your learning process young one.

 

[cbrarick]

Andrew:

I'm happy to mentor adults but no children - sorry 13 and motivated is not the same as 18 and a consenting adult. You can't consent to the potential hazards of EX including poisoning, being burnt or even killed. My son (another dedicated, motivated and gifted kid) doesn't even make propellant. I know it's a bummer to hear, but there's lots of rocketry that is totally good for you to do Enjoy that over the next 5 years, then find a mentor....good luck!

 

[rockets]

Alright; everyone, I'm not trying it until at least I'm 18, probably won't do it for a while after that. I realize the dangers of it, and won't try it.
And also, thank you all for these great tips!!! I very much appreciate all the help, tips, & assistance I can get.

Thanks,

 

[BBrown]

I have never ever heard of nor seen any "unburnt propellant leftovers" when disassembling a motor.

Jim,
Depending on how soon after ignition and how rapidly and throughly you "disassemble" a motor a guy can indeed leave unburnt propellant chunks. Just sayin!
Bob

 

[jimzcatz]

Bob, I hear you, but the physics just don't support that. Unless somehow a burning motor was extinguished. How would that be accomplished? Educate me my friend. Eyes wide open in expectation.

 

[cavecentral]

I recovered propellant from catos. It is usually spongy looking from how it burnt. I would not use these for anything but the burn pile.

 

[Steve Shannon]

Bob, I hear you, but the physics just don't support that. Unless somehow a burning motor was extinguished. How would that be accomplished? Educate me my friend. Eyes wide open in expectation.

I think Bob is referring with some jocularity to very rapidly disassembled motors.
I agree Jim, in a normal burn there is no unburned propellant.

 

[Bat-mite]

A little advice from someone who's 50 and still learning: don't try to live your entire life before you turn 15.

 

[BBrown]

I think Bob is referring with some jocularity to very rapidly disassembled motors.
I agree Jim, in a normal burn there is no unburned propellant.

Jim,
Steve's right. I was sorta kidding. Folks who blow up motors tend to litter a flying field with chunks of unburnt AP. The rapid drop in pressure during the CATO can snuff out a grain much like Warp 9 motors do to delay grains. In any event, the propellant you pick up off the field cannot be repurposed into another motor.
Bob

 

[prfesser]

Bob, I hear you, but the physics just don't support that. Unless somehow a burning motor was extinguished. How would that be accomplished? Educate me my friend. Eyes wide open in expectation.

Hi Jim, many moons ago we were testing homemade nozzles at Jim Mitchell's place. Graphite powder + epoxy makes nozzles that look pretty but erode very quickly indeed. Loaded a 2-grain 29 mm; it burnt for just a moment, then went out. As the nozzle eroded, Kn dropped below the minimum needed for proper combustion. Disassembled the motor. The grains were slightly shorter and the core slightly larger. Assembled the grains with a new nozzle, same thing happened. Grains were even shorter now, with a larger core. I was able to get three test-firings from that one set of grains. Jim remarked that I had made what was probably the world's first reuseable propellant...

Best,
Terry

 

[Steve Shannon]

Hi Jim, many moons ago we were testing homemade nozzles at Jim Mitchell's place. Graphite powder + epoxy makes nozzles that look pretty but erode very quickly indeed. Loaded a 2-grain 29 mm; it burnt for just a moment, then went out. As the nozzle eroded, Kn dropped below the minimum needed for proper combustion. Disassembled the motor. The grains were slightly shorter and the core slightly larger. Assembled the grains with a new nozzle, same thing happened. Grains were even shorter now, with a larger core. I was able to get three test-firings from that one set of grains. Jim remarked that I had made what was probably the world's first reuseable propellant...

Best,
Terry

Good morning Terry.
What's the mechanism that leads to grains extinguishing when the Kn changes like that? Why do the same grains burn in a burn barrel? I assume it's the significant reduction rate over time of pressure rather than simply the low pressure.


Steve Shannon

 

[BDB]

This motor had an instantaneous forward closure failure on the pad. It was kind of like a huge chuff that self-extinguished. The grains were mostly unburned. I put them in a stealth and they flew great at the next launch.

 

[CORZERO]

... EDIT: I checked the safety code for TRA and it doesn't say anything about TMP fliers making research motors.

Thanks,

Well there ya go! Mix it up! Hell, it's better than cooking up meth, right? It also doesn't say anything about midgets, circus clowns or the Kardashians, so I presume they are exempt from the rules as well.

Just make sure when you're ready to blow yourself up not to do it at a launch, insurance will not cover you. And the blood and guts will probably end the launch prematurely and piss a bunch of people off. Whatever you do, make sure you get it on video.

Thanks,

 

[OverTheTop]

Hi Rockets,
You are very keen and I commend you on this. There is a lot that can go wrong mixing your own fuels up. It is as much an art as a science from what I have seen. Keep thinking and learning and get some experience with commercial motors under your belt then start venturing SLOWLY into Ex. Find a mentor that can ease you into it safely.

Play hard, but play safe!

 

[Steve Shannon]

Yeah, I think so. But I wonder what the rules are for TMP fliers. EDIT: I checked the safety code for TRA and it doesn't say anything about TMP fliers making research motors.

Thanks,

You might want to reread that:
With TMP, Junior flyers can design and build high power rockets, and launch their own rockets under the direct supervision of a Senior flyer, or Mentor. The Mentor will handle all aspects of the launch that, due to legal restrictions, require flyers to be over the age of 18 and certified for high power motor usage.

That's because Federal law prohibits the handling of high power motors or metallic cased motors by those under 18 years of age.

 

[Handeman]

There are no TRA rules or restrictions on who can make motors. TRA in no way wants to get involved in regulating or having anything to do with the manufacture of motors, other then certifying commercial motors. The restrictions TRA puts in place is for flying EX motors at sanctioned launches. They require that the flier of record be L2.

I've know at least one minor that made EX motors. His father also made them and flew both of their motors.

With all of that said, unless the minor has their parents full and informed consent and a parent/mentor to help, I would highly recommend staying away from EX.

 

[ksaves2]

There are no TRA rules or restrictions on who can make motors. TRA in no way wants to get involved in regulating or having anything to do with the manufacture of motors, other then certifying commercial motors. The restrictions TRA puts in place is for flying EX motors at sanctioned launches. They require that the flier of record be L2.

I've know at least one minor that made EX motors. His father also made them and flew both of their motors.

With all of that said, unless the minor has their parents full and informed consent and a parent/mentor to help, I would highly recommend staying away from EX.

Yup, In a controlled say club situation anyone can mix, pack or do whatever but they should do it under the auspices of someone or group who knows what they are doing. That said, a minor isn't going to be able to fly one of their creations
unless the appropriately certified flier steps up to take responsibility and sign the flight card. So sure, no problem mixing but there are limitations as to what they can do in reality.

Cripes, I attended a private mixing class as a newly minted L1 and walked home with two K's and an L motor grains. Didn't fly them of course and did the L2 shortly thereafter.

I certainly don't recommend a youngster attempt mixing by themselves without mentoring. Kurt