SpudFiles

im trying to build a hybrid rocket, and i need held finding/casting my solid fuel. Anyone who has experience in the field of amateur rocket, your help would be greatly appreciated. I am working of a 1''x6'' motor and am hoping to build a 1.5''x10'' motor later (if i can get the concept down)

Didn't the mythbusters just use some wax mixed with carbon? That would seem a good choice as it worked well and was cheap.

What exactly do you mean by "Hybrid" rocket?
Excuse my stupidity.

http://en.wikipedia.org/wiki/Hybrid_rocket

some basic knowledge.http://video.google.com/videoplay?docid ... &plindex=5

That video was quite impressive, my idea is this- Find a cardboard tube that fits inside your chamber, a metal rod the size of the desired id of the chamber and a heat source. Lube the rod- make central to the cardboard tube (mould like) and pour in your tar. I don't know what tar i would use though.

yeah the tar is the problem, it is a huge unknown. I want to use ABS but Im not sure.

How about mixing a relatively fine grade of coal together with the tar, it would help it hold together i think, plus it would burn quite cleanly too.
What kind of tar do they use or roads? That seems to set nicely.

Edit: How about using roofing "pitch".

Novacastrian wrote:How about mixing a relatively fine grade of coal together with the tar, it would help it hold together i think, plus it would burn quite cleanly too.
What kind of tar do they use or roads? That seems to set nicely.

Edit: How about using roofing "pitch".

bitumen is what they use on roads, its one of the many fractions of crude oil and it won't burn cleanly, it will produce either co2/co and water when burned.

What region do you life in homedepotpro? The lenth in motors your thinking of will burn for quit some time. If they have suficent thrust, your never going to see you rocket again even with a well timed recovery system. The biggest/longest burning motors iv'e herd of are G-100's, power level being G, burn time being 100 seconds. Really only useable in desert area's of the south western united states. Visabilty reasoning, no humidity gives allmost unlimited visabilty. Here in the north east, I can loose a rocket with a D-11-5, 5 being the delay for parachute ejection charge to deploy recovery system/parachute.

I realize a 2'' motor may be a bit too ambitious but it don't intend to shoot it up. It is more of a science experiment for my physics class. I will most likely end up making a 1.5'' motor

Maybe this is a helpful link to yout project, the oxidiser gas they use is to expensive in my country . Maybe this link will be usefull
http://www.youtube.com/watch?v=hw2uGaImSA8
Tom

Tom wrote:Maybe this is a helpful link to yout project, the oxidiser gas they use is to expensive in my country . Maybe this link will be usefull
http://www.youtube.com/watch?v=hw2uGaImSA8
Tom

Warning: Dail-up users, this video clip is 7+ minutes long. My browser is still running slow!

Mix Saltpeter and sugar on a 1:1 ratio. Then heat it till it melts, then pour it into where you want and let it set. Burns nicely, and makes smoke for traceing the rocket. Hope it helps

MMMh.....interesting, but i've learnt one thing from hybrid rocket engines, you need an important reducer. The smaller du nozzle, the higher the exhaust velocity. you also need to use gal. steel pipe lol, otherwise it wil last a few seconds

CpTn_lAw wrote:MMMh.....interesting, but i've learnt one thing from hybrid rocket engines, you need an important reducer. The smaller du nozzle, the higher the exhaust velocity. you also need to use gal. steel pipe lol, otherwise it wil last a few seconds

True, but you have to be mindfull of to much back pressure, to much and....well....KABOOM! Not enough and a no to low power problem will accure. The proper nozzle has to be used for desired results.