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Awesome Amateur Rocket Launch

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#26 llanitedave

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Posted 12 October 2011 - 11:17 AM

Just read the page. The hybrid rockets do seem pretty cool. From looking at the simplified diagrams I seem to see the possibility of some efficiency losses if part of the oxidizer passes through the combustion chamber without ever making contact with the fuel. I'm sure there are ways of ensuring fairly complete contact, though.

#27 Shadowalker

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Posted 12 October 2011 - 11:34 AM

One of the things they were testing for is combustion efficiency. They tested various sorts of injectors.

Potential efficiency is similar to Gas Generator cycle hydrocarbon engines. All of the ones I've seen are steel cases, which adds significant weight. Aluminum is out because at those temperatures, Aluminum will burn.

#28 shawnhar

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Posted 12 October 2011 - 01:03 PM

What I found much more interesting was the link Carmack uses as an example of documentation.

http://www.rrs.org/m...id=80&Itemid=93

8 Years of work for an 11 second flight right into the ground at Mach 0.6!

#29 Shadowalker

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Posted 12 October 2011 - 09:23 PM

@shawnhar - yeah, that had to be discouraging.

I admit I'm not up on the state of the art in amateur rocketry. Is anyone using guidance? Vectored nozzles? Roll control? I sure would like to see amateur solutions to those things!

#30 KWB

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Posted 12 October 2011 - 10:19 PM

Tom

2 of those abilities you stated seemed to be a bit on display in this video as I watched it.

Once again,any guess what do you think this little fun filled experiment might have really cost?

#31 nytecam

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Posted 13 October 2011 - 04:00 AM

That was a fun ride - good stuff :bow:

#32 FlorinAndrei

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Posted 15 October 2011 - 02:35 AM

Propellant is Ammonium Perchlorate Composite Propellant (APCP)
in a rubber binder with 8% metal powder using a Fin-O-Cyl
grain configuration.


The first model rocket I made back in school (much much smaller than this one) used the perchlorate / aluminum mix for fuel. It burns with a beautiful brilliant white flame. There's almost no residue left.

Also, it's so hot it roasted the bottom of the rocket's tube. The motor itself (a shotgun shell) was destroyed. :)

#33 Ghost7

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Posted 16 October 2011 - 05:15 AM

Great. It's always cool to see amateurs achieving something like this. How much can it cost to this?

#34 Matthew Ota

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Posted 20 October 2011 - 10:06 PM

I dabbled in amateur rocketry from 1981 to 1984. My motors were purchased from a vendor and used ammonium perchlorate in a hydroxyl terminated polybutadene binder (HTPB).

What got me out of continuing it was the political infighting from the rocketry associations and the sheer cost of building and flying the things.

Amateur astronomy is easier on the pocketbook, once you have your equipment in place.

#35 jkaiser

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Posted 30 January 2013 - 06:43 AM

Rocketry associations actually drove the fun out of the hobby, I still design and build my rockets periodically, but don't have the so called certifications. In fact where I live there is nobody around to certfy you, you would have to travel to the closest rocketry club, I dont have time for that and I been building and launching model and high powered rockets for over 30 years.

#36 GlennLeDrew

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Posted 01 February 2013 - 02:41 AM

I don't feel that there is all the vibration feared, requiring image stabilization. The great speed through the air will either induce more vibration than from the motor, or nicely steady out the ride (the likely scenario, methinks.) A clue pointing to the lack of stabilization is provided by the 'stuff' appearing in the window, which is never differentially shifting about in response to an image stabilization scheme.

My first thought regarding the 'stuff' appearing in the window was that it's condensation, not melted material.






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