Rubber Powered Rocket engine

[turbohacker]

I just tested this crude prototype and it produced an impressive amount of thrust for its size. It is constructed of a peice of half inch pipe about 6 inches long. I welded a 1/4" plate with a small hole in it to one end of the pipe and i threded the other end with a standard 1/2"pipe tap. I then threded a "t" into this and plumed up the oxygen bottle. (i had to plumb up the acetylene bottle too just to ignight the rubber, but i can turn off the acetylene after it starts running.) I have only run it off of fuel hose because that is what i had. Anyways i thaught with a little experementation this could be a viable propultion system for some cool projects- heck it worked on spaceship one...





I dont know if the video will work, and if it does than sorry for the poor quality...

[youtube][/youtube]

[rcman50166]

Ahh yes. I see you've discovered the joys of hybrid rocket engines. In one of my former lives I was an amateur rocketeer. They're very powerful indeed. NO2 can also be used as the oxidizer. I would also recommend removing the acetylene starting fuel and use a disposable rocket engine to start the recation. This cuts down weight and will make it possible to carry loads. I would also recomend you use parrafin wax (candle wax) as the hydro carbon. NO2 and parafin wax is the same fuel used on Space Ship One; the revolutionary space plane built by pioneer Burt Rutan to begin his commercial space flight company. The good thing about hybrids is, unlike it's solid fuel counterpart, it is throttleable. This is important for space planes like Burt's. Another plus that comes about by using hybrid rockets is the fact that the two fuels are inert alone. They are only flammable when together. It's almost like your following the footsteps of Homer Hickam. Best wishes on your future developments. Keep us updated on your progress and be careful.

[benstern]

After you try parrafin wax, try using roofing tar that you have molded. (melted, poured into a mold, then cooled in a freezer)

[youtube][/youtube]

[DYI]

Is that your video Benstern, or just one you dug up?

I'm assuming that you simply run a fuel through the line which is ignited when it leaves the nozzle. After you slowly add oxidiser the gaseous fuel begins to burn inside the chamber, heating the solid hydrocarbon. When a massive excess of oxidiser is added, the hydrocarbon ignites.

[turbohacker]

Sounds like you guys understand it slightly better than I. I am having some troble convincing my father that it is safe to experement with (he will be satisfied with a science teacher giving me the thumbs up) He seems to think that the flame could work its way into the oxygen tank and explode, i tryed to explain to him that it is impossibe for this to happen because their is no fuel in the oxygen tank therefor their can be no fire. He dosent bileve my logic, however i will soon have aproval from a local teacher. O well, sometimes its easyer to just jump through the hoops and try to please them rather than being defiant.

[BigGrib]

Sometimes it is best to go through proper channels, that way when you prove it works they will be impressed by the fact that you were able to do it safely and prove them wrong rather than being pissed and dwelling on the fact that you went against their wishes. A couple buddies of mine and I have been experimenting with these hybrid rockets. They are definitely fun to screw with and we are hoping to go to a bigger scale here soon. good luck with your endeavours and I hope you succeed in getting permission to continue to a larger scale.

[turbohacker]

I have been doing some reserch and i dont bileive that it will be much of a problom convincing him. Have you guys tried mounting it to a car or something yet?

[BigGrib]

I haven't built a full scale rocket yet, and full scale mean big enough for the thrust to be useful in propelling an object of some size whether it be a rocket or a car. So far we have used 1" dia plumbing pipe using parafin wax with a 1/4" hole down the middle with a little bit of gun powder mixed in at the bottom for ignition. I'd like to build one that is at least 3" diameter, that'd be something that i'd strap to a go kart frame or something.

edit how many pounds of thrust does your rocket produce, i have no way to measure our little ones yet and wanted a general idea of how much yours produces

double edit @ benstern that's a great idea the roofing tar. My buddy has a shop that has an old roofing kettle outside that no longer works but it is full of tar. I have a very large supply of fuel for my hybrid rockets. Thanks for the idea.

[turbohacker]

I would guess that my small engine would produce about 4-5 lbs of thrust.
I am going to try and mount this setup to a toy car for a school project. I will fill a paintball tank with oxygen and then mount it all to a toy car.

Any Suggestions?

[benstern]

For measuring thrust you can try to mount the rocket to a fixed scale or something.

And no, not my rocket.
heres their other video:
[youtube][/youtube]