REAL Composites.

[Yafmot]

I've looked over the whole rocketry section and couldn't find anything on composites. Since it's apparent that most of you guys' knowledge of the subject would fit in a gnat's ass with room to rattle, and since I have over thirty years experience in the field, to the point of writing about it professionally for a technical publication, I would like to start a thread covering the field.

 

Would it be fitting to put it here, or should I just do a multipart tutorial, or maybe both?

[Ralph]

lovely I don't consider my self to have much knowledge on the subject but there are some who have quite a bit there are a couple threads on composite propellants scattered around. Im not sure how bg gnats are in the US but if they are anything like the ones in Australia than your are mistaken

[Eric70]

Put it in the Members Tutorial section.

 

Keep a lid on your smartass comments.

 

 

I've looked over the whole rocketry section and couldn't find anything on composites. Since it's apparent that most of you guys' knowledge of the subject would fit in a gnat's ass with room to rattle, and since I have over thirty years experience in the field, to the point of writing about it professionally for a technical publication, I would like to start a thread covering the field.

 

Would it be fitting to put it here, or should I just do a multipart tutorial, or maybe both?

[dagabu]

I've looked over the whole rocketry section and couldn't find anything on composites. Since it's apparent that most of you guys' knowledge of the subject would fit in a gnat's ass with room to rattle, and since I have over thirty years experience in the field, to the point of writing about it professionally for a technical publication, I would like to start a thread covering the field.

 

Would it be fitting to put it here, or should I just do a multipart tutorial, or maybe both?

 

APCP has been discussed but we primarily talk about pyrotechnic rockets and not so much about High Power Rocketry. Composites are a little over the top for most of our uses as we would like to bring something up to viewing height and break an effect for viewers.

 

What you are talking about is a returnable rocket because to launch an aluminum motor casing for display is pretty expensive and if you have seen the moderators knock the PVC tubes down for motors, you will see that the Al casings wont make a go here.

 

Pray tell, do you have a new composite that is quick and easy that can easily be used for pyro? I was a High Power guy until 2006 when the ATF put APCP on the explosives list.

 

D

[firetech]

Dagabu, APCP is no longer on that list. I think there is a thread somewhere on here that talks about it.

[Yafmot]

Perhaps I should have been a little more specific. I was talking about composite MATERIALS, not propellants. You know, Carbon fiber, aramids, different grades of glass fiber, SiC fiber, Boron fiber, polymer, metal, and Carbon matrices, processes, Carbon-Carbon etc.

 

As I said, I've spent over 30 years in the field. This, in turn, means I've spent the last three decades fighting the "metal mentality." Continuous fiber reinforced materials are ANISOTROPIC, meaning that they're stronger in some directions than others, depending on fiber orientation. If you try to make a graphite-epoxy rocket motor case and don't know what you're doing, you WILL fuck it up.

 

I recently had to straighten out one guy who swore off Carbon fiber for motors after he had one CATO at ignition. Turns out he used a piece of scrap from a bicycle manufacturer. Of course, that was designed for flexural loads. There was no provision in the layup schedule for internal pressure loads. No hoop strength. Naturally, the thing split wide open. If there were some circumferential reinforcement, he might have had a pretty decent motor (provided he followed a few other do's & don'ts).

 

In other words, you can't just slap this stuff into the shape of a motor and expect it to work. You have to know what you're doing.

[dagabu]

APCP has been discussed but we primarily talk about pyrotechnic rockets and not so much about High Power Rocketry. Composites are a little over the top for most of our uses as we would like to bring something up to viewing height and break an effect for viewers.

 

What you are talking about is a returnable rocket because to launch an aluminum motor casing for display is pretty expensive and if you have seen the moderators knock the PVC tubes down for motors, you will see that the Al casings wont make a go here.

 

Pray tell, do you have a new composite that is quick and easy that can easily be used for pyro? I was a High Power guy until 2006 when the ATF put APCP on the explosives list.

 

D

 

Yup, this past June it came off their list but is still regulated as are all motors.

 

D

[dagabu]

Perhaps I should have been a little more specific. I was talking about composite MATERIALS, not propellants. You know, Carbon fiber, aramids, different grades of glass fiber, SiC fiber, Boron fiber, polymer, metal, and Carbon matrices, processes, Carbon-Carbon etc.

 

As I said, I've spent over 30 years in the field. This, in turn, means I've spent the last three decades fighting the "metal mentality." Continuous fiber reinforced materials are ANISOTROPIC, meaning that they're stronger in some directions than others, depending on fiber orientation. If you try to make a graphite-epoxy rocket motor case and don't know what you're doing, you WILL fuck it up.

 

I recently had to straighten out one guy who swore off Carbon fiber for motors after he had one CATO at ignition. Turns out he used a piece of scrap from a bicycle manufacturer. Of course, that was designed for flexural loads. There was no provision in the layup schedule for internal pressure loads. No hoop strength. Naturally, the thing split wide open. If there were some circumferential reinforcement, he might have had a pretty decent motor (provided he followed a few other do's & don'ts).

 

In other words, you can't just slap this stuff into the shape of a motor and expect it to work. You have to know what you're doing.

 

Uh, huh, wha? Sorry, you want me to lay up a $30.00 a yard fabric along with $50.00 a gallon epoxy just to make pyrotechnic motors? Not only that but then you want to drop them from the sky from 4000'?

 

Unidirectional carbon fiber cloth is longitudinally and torsionaly and horizontally strong as well. However, it is agreed upon that laying up carbon fiber cloth presents real challenges to novices and is easy to mess up due to inexperience. You will need a vacuum to make really good cores too.

 

But why stop there? Lets mill us some graphite nozzles and some Aluminum bulkheads too. That makes a 6# rocket motor cost about $175.00 each without fuel. Lastly, when have you seen a carbon fiber casing without an Aluminum sleeve?

 

If you want to teach High Power, that's fine but consider if you will that most of the stuff we make here cost about $2.00 each to make. The big shells are more, single shot cakes are less. Point being, this stuff is way beyond pyro.

 

How many Tripoli members do we have here? I make one, Yafmot MAY make two...

 

D

 

P.S. I use a lot of laminator cores, I get them for free, clay for nozzles and bulkheads, RC-Candy for fuel.

Edited December 15, 2009 by dagabu

[Yafmot]

And how is anybody who has tired of the same, old, "tobacco road" approach going to progress to the next level of performance? I'm not talking about adherence to some contrived, one-size-fits-all mind mold. What we're dealing with here is optimization.

 

In racing, there's an old saying: "Speed is money. How fast do you want to go?" The same could be said of performance in any field. I'm not trying to trash people who have limited resources. I'm just saying I would be happy to assist those who can appreciate the very best, and are willing to expend the extra effort to get there.

 

Dagabu, show me one currently operational propulsion system that uses monolithic graphite nozzles. That's a job that's reserved Quartz-Phenolic, Glass Phenolic, Graphite FIBER-Phenolic or Carbon-Carbon composites.

 

I began to write a lengthy section on advanced composites for the E&W Forum, completing the section on fibers before the site went down. I'm willing to do the same here, but I can see I've got a lot farther to go to disabuse the members of the notion that composites are out of reach of the average rocketeer.

 

Dagabu, you're still thinking of WOVEN stuff. And WET LAYUPS! That's Fred Flintstone stuff. Sounds to me like there's a whole bunch of people who are more interested in working within artificially contrived limits than there are those willing to roll up their sleeves and learn the real shit.

 

Tell ya' what. if enough people want to learn how this shit REALLY works, I'll be happy to tell you. But as long as you consider anyone who has glued a little cloth together as some kind of expert, and leave it at that, then there's not much hope for you anyway.

 

So if anybody wants to learn the real McCoy, just PM me and I'll try to hook you up with what you need to progress beyond cardboard toys. And as for the rest, if someone gives you a roll of uni tape to play with, don't eat it.

[Ventsi]

I would love to see a tutorial just for knowledge's sake. I doubt I'll ever go into HPR but if I was to do so, it wouldn't be anytime soon.

I'm sure there are a scoop of folks here that would be very interested in HPR. If you have the time to throw up a tut. be sure to post it. I will be greatly appreciated!

[Swede]

Knowledge is good. 90% of the crap I write means zilch to most members, but there are a few guys who I have been corresponding with and we enjoy an exchange of ideas. I for one would always welcome stuff like HP rocketry, but it is up to the mods. It's not pyrotechnic, necessarily, but neither is a lead dioxide anode.

 

Idea: Crank up a blog. What I do that seems to work is do a blog entry, with lots of details and photos, then within the main forum, put up an attractive picture or two, a short description, and a link to the blog. As far as I know, blogs are wide open as far as content and ideas... pretty much.

 

I'd like to read about it, definitely.

[dagabu]

Dagabu, you're still thinking of WOVEN stuff. And WET LAYUPS! That's Fred Flintstone stuff. Sounds to me like there's a whole bunch of people who are more interested in working within artificially contrived limits than there are those willing to roll up their sleeves and learn the real shit.

 

Go for it! Lets see what you got.

 

D

[Eric70]

Yafmot,

 

Pyrotechnic rockets and HPR ones are obviously 2 different things and need to be kept separate. I am primarily interested in pyrotechnics but have always had a strong interest in HPR. I would certainly be very interested in what you have to share.

 

It would be also interesting to know within reason exactly who and what you are. Tell us a little more about yourself. A quick search here with your username did not zero-in on anything specific beyond "30 years of experience." People like me diddling around with BP rockets is small potatoes and of many compared to someone coming in to share information on HPR.

 

Speaking as a guy who is almost 40 years old, I would be concerned that your efforts to bring the fruit of knowledge down to those who do not have a ladder could lead to some dangerous results. I am not ripping on anybody but it is a fact that this is pretty much an open forum and any knucklehead can get access. For you to enable everybody to "learn how this shit works" could backfire. When I say "backfire" this includes all negative things one can think of before and between the concepts of death, injury and domestic terrorism.

 

On the flip side, I subscribe to the mentality that it's not guns that kill it's the people. Also, the cost of materials to pursue what you are detailing would likely prohibit knuckleheads from dabbling with it.

 

Eric

[psyco_1322]

Lets all complain when an experienced person wants to teach us something, ay?

 

I'd much like to hear about composites... tell us a story, I'll at least listen.

 

I actually bought some carbon fiber TOW for use in wrapping the tubes of whistle rockets. Of coarse I haven't got to using it yet because I haven't got them that high in pressure to need it, the tubes are holding.

[dagabu]

I subscribe to the mentality that it's not guns that kill it's the people.

 

I apologize, IMHO this forum is about pyrotechnics, HPR and its components just don't seem to fit this forum but what the heck, fire away (bad pun) and we will see where it goes. Do not be suprised if the moderators take a dim view of this thread though.

 

D

 

BTW- In Advanced Intermediate Maintenance Depot level of F-18 skin repair, lay up was not considered cave man. Perhaps if you could back off the "better than all the rest of us goat ranchers" attitude, we would respond differently, I know I would.

[TYRONEEZEKIEL]

I am also a proud tripoli and HP NAR member.

Not to beat a dead horse, but the differences in High power rockets and pyro rockets are like a a group of tree huggers at a drag race. I believe that only when mixing your own APCP do the two blend much better. On the other hand, an average SINGLE USE of making APCP will cost about $25 U.S. the same in weight of just about ANY pyro comp. id give $5-8 granted it is a big batch.

[Yafmot]

Alright then. I'll put together a tutorial in several parts. I'll start with fibers, then go to matrix materials, then processes, and wrap it up with the exotic stuff.

 

This will be a lengthy body of work, so I'll need to write it on MS word & then transfer it over. But I'm computer brain-dead & don't know exactly how to do it. A little help?

 

Also, it may be possible to pull the first section I wrote for E&W, if someone has a recent archival example. That would definitely speed things up.

[psyco_1322]

I say just write it up in Word like you want. When done, upload it to www.pyrobin.com and post the link to the file or files.

[andyboy]

I wrote a lengthy reply yesterday but I wasn't allowed to post, don't know why. Anyway, I think all info is good info especially when pertaining to specialized fields like this. There aren't to many people that have info about this that are willing to share it on a public forum. Even though we might not have any use for it now, there could come a time when it will be of help to us maybe not in the field of pyro but in any number of fields.

 

My interest for growing plants was of help to me when I planted the willows that I use for my BP although I originally became interested because I wanted to grow "strawberries" in my closet.

Edited December 17, 2009 by andyboy

[Swede]

Yafmot, you don't like my idea of a multi-part blog? Making an entry there is as simple as selecting "New Entry" and typing away. No formatting needed, insert pictures as appropriate, and publish. Plus, you get the added benefit of comments and dialogue for each entry where questions can be asked and answered.

[dagabu]

I wanted to grow "strawberries" in my closet.

 

You can grow strawberries in a closet? Dang, I gotta try that...

 

D

[Eric70]

Yafmot, you don't like my idea of a multi-part blog? Making an entry there is as simple as selecting "New Entry" and typing away. No formatting needed, insert pictures as appropriate, and publish. Plus, you get the added benefit of comments and dialogue for each entry where questions can be asked and answered.

 

I don't think he is reading any of the replies.

[Yafmot]

Yes I am.

[derekroolz]

I wrote a lengthy reply yesterday but I wasn't allowed to post, don't know why. Anyway, I think all info is good info especially when pertaining to specialized fields like this. There aren't to many people that have info about this that are willing to share it on a public forum. Even though we might not have any use for it now, there could come a time when it will be of help to us maybe not in the field of pyro but in any number of fields.

 

My interest for growing plants was of help to me when I planted the willows that I use for my BP although I originally became interested because I wanted to grow "strawberries" in my closet.

 

 

Now if anyone wants to post things from Word or any other text program. Just high-light the text and right click select copy and then go over to the place you want it to be and right click agian and select paste and post.

 

HAHA LMAO at the strawberries in my closet, now I am not recommending it but "The anarcist cook book" has great info on how to grow "strawberries" but also many other plants to.

[Yafmot]

That's it then. I'll just write up the whole damned thing, all the subsections, on Word and then post the whole mess at once. If anyone has an archive of the old E&W forum, I'd like to just use the part I already did on fibers, and basically finish from there. I may have it lurking somewhere on my drive. I'll dig around and see if I can find it.

 

I think it may be best to post it in the rocketry section, since that's by far the main area where this information will be of value. I'll also be sure to provide lots of sources for this stuff. Just as importanly, a lot of REsources (SAMPE, AIAA, MRS etc). I'll also try to include applications information, so some of you would be less likely to misuse the stuff.

 

But keep your collective shirt on. This will take a while.