Going for 100,000 Feet

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I hate to be that one guy.... But has anyone considered launching from a high altitude balloon? Can BP ignite that high? And I guess stability would be an issue... But has it been Done?

I worked with a few collegiate rocketeers who worked on developing such a system. Their biggest difficulty, by far, was FAA approval due to the perceived unpredictability of a weather balloon at altitude.

Alex
 
When I get to staging and firing apogee charges over 25,000' I will use compressed CO2. BP disperses too quickly so a lot of it does not ignite.
 
I had a design for a kite-launched rocket, but was discouraged from attempting it because launching from an airborne object is against NAR and TRA rules.
 
I had a design for a kite-launched rocket, but was discouraged from attempting it because launching from an airborne object is against NAR and TRA rules.

Isn't that what a second stage does?
 
Isn't that what a second stage does?

Kinda sorta yes... but the rocket staging is more controlled than launching from a kite or a balloon, which is much more unstable. I know it is not allowed to launch a rocket from an RC aircraft.
 
Kinda sorta yes... but the rocket staging is more controlled than launching from a kite or a balloon, which is much more unstable. I know it is not allowed to launch a rocket from an RC aircraft.

Interesting. Can you cite the specific lines in the safety codes?
 
Interesting. Can you cite the specific lines in the safety codes?

The issue has to do with launch angle. With a kite, balloon, or RC aircraft, you cannot reasonably guarantee a launch angle of 20 degrees or less. You can with a 2-stage rocket. And with all due respect, I suggest you start another thread on the subject. Thanks.
 
Anyone care to comment on the components for the first rocket in this project?
 
Coyote, It is a good discussion, but it is not something I am going to do, nor is it something that would qualify for a TRA or NAR altitude record. I'm not trying to cut you down. I'm just saying that the discussion should have and deserves a separate thread. You would reach lot more people who might be interested in the topic. For instance, I would post to it with designs for my kite launch idea there. I won't do it on this thread.
 
Coyote, It is a good discussion, but it is not something I am going to do, nor is it something that would qualify for a TRA or NAR altitude record. I'm not trying to cut you down. I'm just saying that the discussion should have and deserves a separate thread. You would reach lot more people who might be interested in the topic. For instance, I would post to it with designs for my kite launch idea there. I won't do it on this thread.

I have no interest in launching rockets from kites, nor do I wish to start a discussion on the subject. I was simply curious as to what was written about it in the safety codes, and since you seemed to have knowledge about the exact rule, I asked you. Dave's response was appropriate - he cited the lines in NFPA 1127 relevant to the matter. On the other hand, you effectively told me to piss off.

In any case, I'm not going to argue with you about it. If you take issue with the discussion taking occasional tangents, a discussion forum is probably not the best place for you to be documenting your project. I suggest looking into a site like WordPress where you have total ownership of the content. Just an idea.
 
As I said, it is a cool topic, but it is not relevant to this particular thread. Too many safety issues related to Newton's Third Law. David and I responded almost simultaneously to your question. Had I seen his response I would have not responded.

I am by no means the expert on this. I set up this thread so that I could take advice about high altitude, multi-stage rockets. You are more than welcome to discuss the build, ask questions, or be critical of some of the build and flight techniques.

The discussion went out on a tangent. I even responded to the tangential discussion. Now I'm bringing it back in. That's all. Trying to stay focused here. Sorry you took it as an insult. It just does not make sense to discuss something that is borderline legal or against regulations in reference to this particular project, which will not use those techniques.

Please, let's get back to the discussion.
 
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Sustainer fins being attached to the airframe. This is a thin layer of Rocket Poxy at first. I will use RocketPoxy for fillets, then dilute a mixture of RP with alcohol and do a T-to-T attachment. I may not need it with a 29m motor and airframe, but I could use the build practice for the larger and higher altitude versions.

Do 003.jpg
 
When I get to staging and firing apogee charges over 25,000' I will use compressed CO2. BP disperses too quickly so a lot of it does not ignite.

Several folk have used BP over 100K - You just have to know how to contain it/set it up.
 
Sustainer fins being attached to the airframe. This is a thin layer of Rocket Poxy at first. I will use RocketPoxy for fillets, then dilute a mixture of RP with alcohol and do a T-to-T attachment. I may not need it with a 29m motor and airframe, but I could use the build practice for the larger and higher altitude versions.

View attachment 297634


DANGER WILL ROBINSON.....DANGER!

Rocketpoxy is an adhesive loaded with fillers, great for bonding & fillets. You need a laminating epoxy for glassing T-T.
 
What do you suggest?

I am partial to West 105....only because I have a West Marine store near by, making it super handy when I need/run out of material. They carry all the fillers ,cloth, materials needed. This is more costly than on-line, but convenience for me rules.
I have used other epoxies for various minimums , and as far as I'm concerned there isn't much difference between them other than cost.
Most all will exceed the needs for all but the MOST Xtreme builds, where maybe high temp. requirements are needed.
I don't think any of your 3 projects fit into that category.....but that's just me/my opinion.

In your case, I would either figure out what to use on all 3 builds, and begin buying supplies now. OR:

Simply get a couple of Hobby bottles of laminating resin such as Z-poxy, only 20 bucks, continue with your 29 project just to learn T-T method and save time. Then get a better, premium product, later on when time to research allows.

The flood gates have now been opened and "epoxy gate" will begin with the normal plethora of which epoxy to use opinions.

Some where in a epoxy thread ,I listed PDF's with the actual manufacturers of ALL epoxies and who they were formulated for etc. There are only 3 resin makers, who send to distributers when then formulate for all the different epoxy re-sellers. If someone could find those lists it would really help you get through all this.
 
Laminating epoxy is required for fiberglass or other composite reinforcements because its thin enough to be easily absorbed by the fabric. It's also just strsight, un-ammended epoxy, you can add your own fillers.

Both Aeropoxy and West Systems are good choices. I prefer the Aeropoxy and get it at Aircraft Spruce. I use the 2032 resin and 3660 hardener which gives you a 1 hour working time. It's probably the most popular combo.

https://www.aircraftspruce.com/catalog/cmpages/aeropoxy.php

You can also get West Systems at Aircraft Spruce. But if you have a West Marine store locally you can get it there as well. The 105/205 combo is the most common and also gives a 1 hour working time.

https://www.aircraftspruce.com/catalog/cmpages/westepoxy.php

There are more choices as well and someone else might chime in with their preference. Slower hardeners might also be nice if this is your first foray into tip to tip.
 
Laminating epoxy is required for fiberglass or other composite reinforcements because its thin enough to be easily absorbed by the fabric. It's also just strsight, un-ammended epoxy, you can add your own fillers.

Both Aeropoxy and West Systems are good choices. I prefer the Aeropoxy and get it at Aircraft Spruce. I use the 2032 resin and 3660 hardener which gives you a 1 hour working time. It's probably the most popular combo.

https://www.aircraftspruce.com/catalog/cmpages/aeropoxy.php

You can also get West Systems at Aircraft Spruce. But if you have a West Marine store locally you can get it there as well. The 105/205 combo is the most common and also gives a 1 hour working time.

https://www.aircraftspruce.com/catalog/cmpages/westepoxy.php

There are more choices as well and someone else might chime in with their preference. Slower hardeners might also be nice if this is your first foray into tip to tip.

I will add US Composites 635 with Medium hardener to the list of excellent laminating epoxies. Its less expensive than either Aeropoxy or West products, I have also found it easier to work with, and it has three hardeners available Slow, Med, Fast.
 
I used West Systems G-Flex on my last T-to-T build. Rocket went up well, but was lost so I don't know how it stood up. I can get the West Systems 105 stuff at a boat supply store. Thanks everyone for the advice. I will go ahead and fillet with RocketPoxy.

As I said, for this rocket the T-to-T isn't necessarily needed but I wanted the practice. The fins simmed to Mach 2.1 just being butt-jointed on a Fin Sim flutter analysis, and this flight will be closer to a max of Mach 1.75. . That assumption was made with RocketPoxy having a 6,000 PSI shear strength instead of their stated 14,300 PSI strength.

However I am hoping to fly this 5-6 times before I build the next rocket up, so overbuilding is a good idea.
 
I spent 2 hrs this morning "re-finding" some of my research to post here. Originally I have months of 3-4 hrs a day doing this. It's the ONLY way you will feel comfortable with your final decisions if your serious about this stuff. Google is your friend.

After discussing adhesion issues with Dr J [CTI] i found they glued aluminum fins, directly bonded to carbon airframe, with this Hysol product.

DSCN5941.jpg

My little go fast project, 75mm minimum, using Hysol. 3M makes a equally good product, by the way. I chose Hysol.

DSCN5950.jpg

The project [CTI] went Mach-5 with no T-T, just hysol glue holding the fins on with a 5 thousandth's glue gap.

I DID find my PDF of Glue making.....:

View attachment 2006_EpoxyDoDonts copy.pdf

The 3M one: Too large to load.

You just need to Google epoxies, go to the different sites and read all the product research PDF's. It is an eye opening experience.

Good luck with your project, it's a long hard road.....but worth it.:smile:
 
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I spent 2 hrs this morning "re-finding" some of my research to post here. Originally I have months of 3-4 hrs a day doing this. It's the ONLY way you will feel comfortable with your final decisions if your serious about this stuff. Google is your friend.

After discussing adhesion issues with Dr J [CTI] i found they glued aluminum fins, directly bonded to carbon airframe, with this Hysol product.

View attachment 297656

My little go fast project, 75mm minimum, using Hysol. 3M makes a equally good product, by the way. I chose Hysol.

View attachment 297658

The project [CTI] went Mach-5 with no T-T, just hysol glue holding the fins on with a 5 thousandth's glue gap.

I DID find my PDF of Glue making.....:

View attachment 297657

The 3M one: Too large to load.

You just need to Google epoxies, go to the different sites and read all the product research PDF's. It is an eye opening experience.

Good luck with your project, it's a long hard road.....but worth it.:smile:


LOVE THIS!!!
 
So this is the setup of Do.. Fins tacked on. Will add fillets. Not sure now about the T-to-T. May save that for the next rocket. This sims to 20,000' on 640 NS. The rocket is a shade under 4' tall.

I present to you the first note of the scale... "Do." Thanks again to Dan Patell for the nose cone; Nat Kinsey at Upscale CNC for the fins, fin jig and bulkheads; and Mad Cow Rocketry for the 29mm thin wall FG airframe.

Do 005a.jpg
 
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The fin alignment guide/cradle does good work for fillets because Rocketpoxy has a good tendency to settle well, and with the fins laying in a level position, the center of the fillets should bisect the angle made by the airframe and the fin.

Do 006.jpg
 
Looks good. Does the size of filet matter much if you are planning to do T2T?
 
So this is the setup of Do.. Fins tacked on. Will add fillets. Not sure now about the T-to-T. May save that for the next rocket. This sims to 20,000' on 640 NS. The rocket is a shade under 4' tall.

I present to you the first note of the scale... "Do." Thanks again to Dan Patell for the nose cone; Nat Kinsey at Upscale CNC for the fins, fin jig and bulkheads; and Mad Cow Rocketry for the 29mm thin wall FG airframe.

View attachment 297675

Looks fast!

This is a very cool goal and an interesting thread. Best of luck on your endeavor!
 
Looks good. Does the size of filet matter much if you are planning to do T2T?

I'm keeping these fillets at no more than 1/8." Small fins and airframe don't need that much. Beyond adding strength, they also help aerodynamically and also help to make the T2T application a little easier because there are no hard corners to worry about.
 
As the final set of fillets harden I decided to work on another integral part of the airframe; the interstage coupler. The rocket, "Do" is going to use CTI motors because an H255 staged to a second H255 is 99% of a full "I", and that combination sims to the highest altitude. Plus, CTI makes a tapered 29mm aft retainer than comes up to flush with a 29mm airframe. Unfortunately, apart from heavy sanding and grinding of aircraft-grade aluminum, that means that the sustainer needs to be coupled to the booster externally, rather than internally. So I am fabricating a sleeve that will be glued to the interstage coupler. The sleeve will extend 1.5" from the coupler and the sustainer will slide inside it. and rest on the end of the coupler.

Making the sleeve involves using a leftover piece of airframe as the form. I wrapped a single layer of 3 mil plastic around it, then scotch-taped it tightly together. Next I applied G-Flex epoxy to the plastic, then wrapped 2 layers of 6 oz. fiberglass cloth. Then I made several wraps with more plastic and compressed it around the airframe. Finally I tightly wrapped masking tape around everything so it can set.

My hope is that I will end up with a very smooth tube that will slide over the airframe. It should be between 1/32" and 1/64" thick, and be strong enough to hold everything together until staging. Another possible added benefit is that once the booster motor burns out, it should drag-separate off the sustainer, although I am still planning on using a charge for safety sake.

This is how it looks wrapped in place. It will take most of the night to set.

Do 007.jpg
 
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