Propellant Mixing Questions

I was a little surprised to see people mixing their own APCP on Rocket Challenge. Some questions for those of you who have "rolled your
own":
Is this a common occurance in HPR?
What kind of quality can you get from home made APCP? (Does home made propellant tend to cato, have combustion instability, great batch to batch variation, or other problems?)
Any safety incidents? (accidental ignition, near misses, etc)?
WHY do you mix your own? (cost, can't get the right size motor, fun, etc)
I'm asking this out of curiosity. I am not associated with any rocket company or any government agency (real or imagined). I am merely a low/mid power rocketeer killing time on my lunch hour.
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snipped-for-privacy@yahoo.com (Ed Giugliano) wrote:

Never.
All of the above from person to person, and it is in the catagory of "amateur rocketry". It is wacky TRA that intentionally confuses HPR with Amateur rocketry against the advise of the longest running vendors, and national associations, and of course the law and the regulations.

No. APCP is inherently safe (well safer than about anythiong else), but precautions are an essential thing anyway. Best to mix outside (which is a scheduling and geographic bind). Your first propellant accident WILL be your last.

Interaction. It is more expensive, less reliable, harder, more legally vague, etc.

I run a rocket company and have all the equipment, materials, expertise in stock, and it is such a pain in the ass to make propellant I buy at full retail anything I need before I will make a custom motor.
Jerry
--
Jerry Irvine, Box 1242, Claremont, California 91711 USA
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snipped-for-privacy@yahoo.com (Ed Giugliano) writes:

Once you have done it for a while, the number of failures should be pretty small.
From what I've seen, most CATOs are from someone making a bigger motor than they have ever made before.

Never heard of any.

People do it for all of the above reasons. There is only one commerical O motor and no P motors, so you pretty much have to make your own.
The upfront investment is high. The cost savings only comes from making lots of big motors like Ms and above.
Brian Elfert
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That is grossly false. Several real aerospace companies offer them commercially.
HPR ends at O (used to be M then N). Plenty of non HPR D-O motors are available commercially.

Jerry
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Jerry Irvine, Box 1242, Claremont, California 91711 USA
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HPR (as practiced by Tripoli) has used pre-manufactured motors, either single-use or reloadable. While experimental and amateur rocketry enthusiasts have been making their own motors since the beginning of time (ok, maybe a little more recently than that)
motor making was a Verboten subject in NAR and TRA, actually prohibited by their safety codes. However, TRA recently permitted "experimental" launches where home-made motors could be used by flyers already certified at Level 2. But this is relatively new to TRA, and few prefects sponsor experimental launches. Others feel free to correct or expound on this point.
OTOH, The Reaction Research Society has been doing this since 1943. See their website at http://www.rrs.org and their courses under development at http://www.rrs.org/RRS_Courses/rrs_courses.html
I'd also suggest a visit to the IEAS FAQ: Advice to Novices at http://portal.corlabs.com/PortalVBVS/faq-novices.html
IEAS is an national organization which focuses on Experimental Rocketry their website is at http://www.ieas.org
now if you really want to get excited, IMO, visit John Wickman's Rocket Camp webpage at http://www.space-rockets.com/camp.html
The Rocket Camp is an educational outreach program for students to learn about rockets and space exploration. Unlike other types of camps, this is a hands-on program where students work with shop tools and build their rockets from scratch. Unique to this program is that the students will be working on the shop floor of a real aerospace company. They will be able to interact with engineers and technicians as they attend the camp. Enrollment in classes is around five students for a maximum learning experience.
Go to The Rocket Camp Homepage and find out about a variety of great programs for students interested in Rockets and Space. The Rocket Camp For Kids Of All Ages!!! Click here for The Rocket Camp Homepage.
Rocket Camp Programs * Build High Power and Amateur Rockets * Design and Build Your Own Solid Rocket Motors
I plan to take my two boys to Wyoming this and next summer for the camp
- iz
Ed Giugliano wrote:

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Unfortunately for those of us on the East Coast, RRS is too far away and is of little use. I would like to attend Wickman's camp (since it the only propellant class that allows minors in and I'm a high school student) but it is a hassle to get out to Wyoming. So far, I've made five 38mm motors, three of which have been fired, two of which are ready to be fired, and only one so far has CATO'd (manufacturing fault, not design error). Since I've had no traing from a professional, I've had to rely on the books and my father, who is a P.H.D. organic chemist.
To answer the original poster's question, rolling your own motors is not a common practice, yet. I do it for the extra amount of involvement. I like to get right down to the heart and bare bones of the system, and toy with that. It becomes more of a precision science than a hobby. I don't do it to save money (prices only break even when you make large motors). With the right equipment and experience, the amateur can make a quality propellant that is just as consistant and reliable as the commercial motors. It is more expensive in regards to the time and brainpower necessary to make your creation come alive. CATO's usually occur due to user error, whether it be a conscious error or otherwise. Handling uncured propellant is no less safe than handling cured propellant. The main hazard is the use of finely powdered metals, which are highly flammable. Once those are mixed into the wet binder, much of the danger goes away. Simple common sense is used to avoid accidents.
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consider the Maryland Delaware Rocketry Assoc. (MDRA) [ website at http://www.mdrocketry.org ]
Upcoming launches are 9:00-5:00 Saturday & Sunday
Dec 13-14, 2003 Jan 10-11, 2004 Feb 7-8, 2004
at Higgs Farm with a 14,000' MSL, 13,900' AGL waiver for the whole launch day
see their launch site location at http://www.mdrocketry.org/directions.html
- iz
Brian McDermott wrote:

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Maryland is still too far. I was thinking more in the Boston area. No more than 150-170 miles. I was thinking of proposing an independant rocket club, not endorsed by NAR or TRA, but I don't know how many would be interested.
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Brian McDermott wrote:

Brian
Contact me offline, there are a couple New Englanders who make the trip. It's a fair ride to Maryland and conversation *might* be something to make their ride go quicker........converstion about motors maybe. ;-) take out the .nospam
--

Chuck Rudy

VooDoo Digital Productions
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snipped-for-privacy@attbi.com (Brian McDermott) wrote:

You could start it and find out. Build it and they will come.
Well leeches from TRA will come too and try to take over (ascimilate) so make sure your waiver of liability also gives you rights to take action against those sorts of actions.
--
Jerry Irvine, Box 1242, Claremont, California 91711 USA
Opinion, the whole thing. <mail to: snipped-for-privacy@gte.net>
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both ARSA and IEAS will have new clubs formed throughout the U.S., and IMO the east cost (esp. northeast) is especially ripe. John Wickman has said that the number of new member requests he received this month is unprecedented, many of whom are have expressed interest in forming local groups
for information on how to form an ARSA group, see http://www.space-rockets.com/arsaform.html
for information on how to form an IEAS chapter, see http://portal.corlabs.com/PortalVBVS/DesktopDefault.aspx?tabindex=2&tabid=7
I don't know of any EX launches closer than 3 hours from New Yoik City (my hometown), the closest is the far side of CT, but those are rare. They would be CTRA/NARCONN (NAR) with a 5,775' AGL ceiling (75% of waiver). I haven't seen any EX launch announcements from CATO (Tripoli).
- iz
Brian McDermott wrote:

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Ismaeel Abdur-Rasheed wrote:

Just don't drink the Kool-Aide! ;)
-John
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I don't think it's real common practice, but many people tend to talk about it a lot. I think motor making depends mostly on if you've got a local friend you can learn from. Learning propellant making on your own is at least twice as difficult as learning from someone else. I learned how from another fellow, and I've intro'ed 6 others.

Because homemade propellant makers typically don't have the same equipment that commercial makers do, I would have to guess that quality (on average) is slightly lower on homemade propellant, but only slightly. I personally have made over two dozen motors from H to K, and only had one surprise cato. But I design all my motors for the conservative end of the scale. My friends are all more confidant of my motors than I am!

Not for me. I feel way more safe doing this than making black powder or fireworks. But everyone has different levels of acceptable risk.

Cost? Yes. After the initial investment, I can make a full J motor for less than $7. Can't get right size motor? Yes, when I started making motors, I couldn't get 54mm motors without a LEUP (Although I do have an LEUP now). Fun? Yes, I find motor making very fun. While people all have their own areas of interest, some like gliders, some like cameras, etc..., I like propulsion. For me, the step after seeing rockets that you built fly, was to see them fly on motors that you make. The exhilaration I feel is just like flying my first G motor. I've told all my friends that if they build the rocket, I'll make the motor.
My suggestion to anyone would be if you can take part in a motor making session, do it. Even if you don't pursue it on your own, helping someone make motors is very educational in understanding how they work, and your teacher would probably appreciate the assistance.
Kevin Rezac
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Any comments about the trade-offs between making your own APCP motors vs making sorbitol-based motors?
--
...The Bit Eimer [remove keinewurst to email me]

"My goal in life is to be the kind of person my cat thinks he is"
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bit eimer wrote:

In general sorbitol (or other "candy") formulations are cheaper per motor - but both candy and APCP are cheaper then commercial motors, especially when you are making larger engines. By both weight and volume APCP (and is close relative ANCP) are more powerful then candy engines. The materials used to make candy propellants are far safer then APCP and ANCP - of particular note is the danger of aluminium of magnesium powder used in the APCP/ANCP engines - highly flammable, and if a dust cloud is formed there is a high risk for explosion. AP itself can be dangerous, as it will react with many materials including some fabrics. Once APCP/ANCP engines are cast they are very safe. Candy is safe through and through - you can eat the sugar, and KNO3 is not explosive (or even flammable). There has been some concern lately that nitrates, including KNO3, may be weak carcinogens so you may want to avoid direct exposure to the KNO3. The biggest downfall of candy is the use of an oil bath - the risk of the bath causing a fire or serious burn to yourself is far higher than any danger from the propellant itself.
Bryan Heit
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Thanks for the info.
--
...The Bit Eimer [remove keinewurst to email me]

"My goal in life is to be the kind of person my cat thinks he is"
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Ed Giugliano wrote:

It depends where you are. In some locations it's unheard of, in others it's all the rage. It's definitely growing. I sell some supplies for making propellant and business has been steadily increasing for several years now.

It's not too hard to match or exceed commercial quality. This depends, of course, on how you measure "quality".

There's nothing to prevent you from making excellent propellant every time that you mix. It's not hard to do, but it does take dicipline.

I've only heard of one accident with APCP in the past five or six years, and the one accident was a commercial manufacturer.
Propellant is a dangerous fire hazard. Never forget that and you will never have a problem.

All of those.

Check around at your local TRA clubs and find out if any of them hold experimental launches. Attend one if you can and see for yourself!
-Jeff Taylor www.lokiresearch.com
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Depends. HPR is non denominational as far as we are concerned, it encompasses all of rocketry, regardless of monikers or .org affiliation. High Power Rocketry is precisely that, and expanding based on whatever you call it, Amateur, experimental, et al. Its not for everybody, only those willing to take the next step.It is growing, for many reasons, see below...and above all, don't be dismayed by definitions proferred with alterior motives.

I have kept a log for the last 5 years of commercial versus EX launches at our local club. The failure rate (CATOS) of commercial versus EX has been interesting, to say the least. But first, realize that we (the local club) tightly control motor making for individual, non commercial use. In a nutshell, the success (non cato) rate for commercial propellant has in our experience been logged at 93.857 percent. EX, 99.532 percent. Total NS expended for EX versus commercial as a percentage, EX 75.257 percent, Commercial, 24.743 percent. Motor by motor H and above, almost dead even. Performance? First, allow me this caveat...responsible mgs have to take into account liability, the idiot factor, and suit happy individuals who do not wish to exercise their own responsibility. Sad, but true. For instance, Cessna has the capability of mfg a 152 aircraft for 20k, but because of the tort malfeseance (IMO) existing in this country today, it would sell (should Cessna restart production) for over 60k. OK, back on topic, the well disciplined, safety conscience individual can meet or exceed performance of mass produced motors, in most cases.

By safety, I would have to say the only issues we experienced was a J class commercial cato that caught fire near the pad and burned up some launch control relay equipment, but it did not endanger anyone due to our safety codes.

Frankly, it started for the satisfaction of being totally responsible for your project. Then it morphed into availability of reloads due to some mfg's inability to meet demand. Then it realized startup investment cost recouped, and the economy part kicked in (providing you are not lazy and are willing to provide the effort in duplicating a consistent product). As time and experience went on, our reliability records with self made, for individual use, non commercial motors exceeding commercial success became a confidence issue. Just last week a local club member, a veteran of dozens of successful EX flights, used a commercial motor...it catoed. And while I am on the topic of making your own motors, safty is key. For one thing, I don't recommend the raw novice to machine APCP grains with a miter saw like you saw on TV. Though Morton Thiokol does it in closed cells, it is not recommended for people who have little experience.In fact, the whole propellant making process you saw on the DC show left out many safety features we incorporate. But, as they say, "Thats showtime". If you are really interested in "rolling your own", I recommend taking a class given by people who know what they are doing....and no, I don't give classes..

I appreciate your questions, and I enjoyed giving you a brief synopsis of our experience. Rocketeers by nature are indeed "obsessed", and for good reason, it is the most exciting hobby on the planet. Not only exciting, but demanding, for you can take it as far as you are capable, and then some. I have learned more in this hobby than any hobby I have ever experienced, and I'm just scratching the surface. And all due to people who are willing to share what they have learned.
Pat G
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snipped-for-privacy@aol.com (Potrocs) wrote:

This is a very new and recent trend.
For the longest time any mention of non-commercial, non-certified motors or especially ANY motor making principals resulted in hard core flame wars from long time and well known NAR weenies.

This Tripoli profferedconfusionisbad.
Compartmentalizedrocketrymattersfor local permissions.
[consumer] Model Rocketry [consumer] High Power Rocketry [experimenter] Amateur Rocketry
ANY other variance from those terms are illegal, unhelpful, confusing, and a generally bad idea.

There is NO "EX" anywhere in the world except in TRA nomenclature. This is a roughly 3000 member club. There are perhaps 1 million rocketeers worldwide or so. It is instructive to remember this very same club brought the ire of the ATF on the whole of rocketry, is singularly tolerant of repetitious promises of magazine deliveries that never materialize, despite prepayments, and furthermore are at the nexus of intentional and proven misguided regulatory efforts, and CRIMINALIZATION of rocketry despite its impeccable safety record, largely established by predecessors of TRA.
TRA is a public hazard.
Jerry

--
Jerry Irvine, Box 1242, Claremont, California 91711 USA
Opinion, the whole thing. <mail to: snipped-for-privacy@gte.net>
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Jerry, I didn't offer this as a Tripoli profferred comment. It was from me, we. Self described individuals. Realizing our own goals, regardless of affiliation. Chill son, leave your politics behind, and lets have some fun...surely you ain't so old you forgot how to have to have fun, hey?
Pat G

I offer my explanation and its illegal. Drat, guess I'm going to jail or getting sued now for free speech.....
And the Judge says....Pat G, I sentence you to untold years for not following Jerry definitions of Rocketry Allowed Descriptions. Hee hee. come on Jerry, you forget were friends or what?? Had a bad nite? Girl Friend stand ya up? Bourbon substituted for Tea by yore last buddy visiting ya? Jealous cause I make better P motors than you?.......woo hoo, that oughta get ya riled up....chortle, chortle. Too much fun, guess I'll go to bed now, can't wait for manana, Jerry, don't be cruel while I snooze.......nite...
Pat G
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