Polyethylene + GOx Hybrid rocket test fire 3

[wobbba89]

I love the *burp* in the end xD

[furburger27]

I am testing with a similar design using solid ruber and gos and I keep burning up nozzles when the psi is above 40 or so are you having a similar problem are do you use a different nozzle material I am using grade8 steel but am considering graphite.On a side note I tried to use a small spray can for a gos tank for static tests (BAD IDEA) and it blew up while against my chest leaving the worst brusing Ive ever had Im lucky to be alive!

[d2001griffiths]

Not to far from being a pipe bomb/IED

[ricande]

ROFL... I love the little puff at the end.. Sooo cute. :D

[denisoG1]

каловое неустойчивое горение

[gopherbar]

Nice firework :O) ill have 10 please.

[d2001griffiths]

You know, It is a realy bad idea to stand next to something that you made your self the could explode.

[Nerusai]

I concur, you clearly were handling the camera yourself and the oxygen is in the mixture so there is danger of an explosion occurring.

It's safer to mount the camera on a tripod and make sure you're safe behind something really solid.

[d2001griffiths]

exactly, nothing like something going boom and shards of mettle in you.

[Nerusai]

Even small explosions can severely damage, for instance, your eyes.

Take precautions, wear safety glasses etc.!

[d2001griffiths]

I was hit by an IED in Iraq and can say that it realy sucks to have something blow up any whear near you. It injured me me and fucked me up for life. I went to see the fire works for the forth and couldn't handle it.

[cheeseboat15]

It's called post tramatc stress syndrome. You'll get over it eventualy

[croniclone81]

@cheeseboat15 u got no fuckin respect,i would like to see u get hit with a bomb bitch

[BowToYourHighness]

Sorry for your loss, man. Much respect for your service. Where do you live?

[larfingshnew]

whats mettle?

[nicksynnz]

Wow you had the thrust of at least an H motor.

[Bellithe]

lol was the blue flare, at the end, zinc burning off from the end of your pipe?

[arpoot]

How do you use polyethylene as a fuel?

[arpoot]

Or, rather, why would you use it as a fuel, instead, of say, kerosene?

[didaloca]

@arpoot

The reason it's called a hybrid is because the fuel and the oxidizer are in diffrent states and are not mixed.

If kerosene was used, it was just be a "liquid rocket motor" and not a hybrid.

Polyethylene is a good fuel because it has lots of energy stored and is not explosive.

To use polyethylene as fuel you can just melt it down into a "tube" that you can fit inside the rocket motor.

[Nerusai]

While it's one of the safer contraptions you can make, and it being pretty safe until you turn it on, it can most decisively so explode after you do so.

[didaloca]

Sure, but who cares? If he kills himself then whatever. Wont affect you or me in the slightest.

[Nerusai]

Yes it will? As a species we can use every endeavoring individual we have, for all we know he could be the next Einstein.

Plus such a warning could help future individuals watching this to build their own contraptions to stand behind something solid and not hurt themselves either.

Humans are also altruistic, there is (almost) no cost incurred for me to place that warning, and the reward (to others) could be tremendous.

So be a little more caring and share knowledge instead.

[didaloca]

There's no point, having built one of these myself. I know the pressures involved and I also know if mine exploded I would not be harmed. Even if I was standing over it.

Also, anyone cleaver enough to literally discover and prove laws of physics are capable enough to understand they might be harmed by a silly little device designed to reach high pressure.

[didaloca]

I quote: "There should be no capital punishment for idiocy; but why not remove the safety labels off everything and let the problem solve itself?"

[yaventil]

wich gas u need for that?

[MediaNexus]

Polyethylene and Oxygen.

[rockets2space]

Wow that was fantastic! Great job =) What was the oxygen pressure?

[boltingskyline]

You should try a Titanium-Benzidrine Compound mixture, this will stop meltdown of nozzle. Best Wishes.

[PepeVonBraun]

where do you get the hose and regulator for the benzomatic oxygen tank?

[davekimgansen]

target i'm sure

[Rocketmang]

home depot

[wasd591]

@Rocketmang Epic reponce ^ :D Cheers.

[pitbike2006]

is thats 15mm copper pipe

[wolboatpo]

so?

[pitbike2006]

just wanted to know if it is 15mm pipe thats all

[Rocketmang]

yes it is

[pitbike2006]

ok thanks and how did you connect a 15mm to a iron fitting like that

[manvstaco]

:) I like it...

[cheeseboat15]

That was amazing, the only thing that went wrong was the nozzle decomposed to an oxide!! Bravo! The only hurdle now is the nozzle and you will be golden

[FTWMikeDero]

looks like your nozzle decomposed a little..

[JKG317]

What is the diameter of the rocket body? And the nozzle?

Also, how did you throttle the oxygen to get the true rocket burn at :17?

Thanks

[Rocketmang]

The diameter of the rocket body is 5/8 inch inside diameter, its just a 6 inch brass pipe nipple.

The throat diameter of the nozzle is 3/16, I just drilled through the steel end cap for that.

[Rocketmang]

In order to throttle the oxygen I have a 1/2 inch ball valve adapted to the other end of the rocket, just off camera to the right. Before I light the rocket I crack the valve open just a bit, enough to hear the oxygen hissing. Then I light the rocket and when it starts burning as at 00:15 you know the fuel is cooking nicely inside, then just crank the oxygen up all the way and you get a plume like in 00:17.

[JKG317]

Hey, thanks. Are you still building hybrids?

Any tips for tar rockets?

[Rocketmang]

Yeah I'm currently working on larger scale hybrids. As far as tips go the most important thing to know is how to get the combustion happening properly as I described above. Once you have the hang of that its just a case of taking any fuel you think might work and drilling a hole through it. Make sure any fuel you use is tight to the wall of the rocket so the oxygen doesn't start burning the fuel from the out side in.

[Rocketmang]

Oh, but more specifically to do with tar rockets, make sure you have the right kind of roofing tar. The kind at home depot that comes in a can doesn't harden. You need asphalt roofing tar that hardens for this to work properly. Find a roofer and see if you can get a couple of chunks of the hard stuff from them, sometimes they have scrap stuff just laying around, otherwise you have to buy a melt pack off them and break chunks off of it.

[Rocketmang]

To form the Tar throw it in a coffee can and put it on a propane stove outside. When its all melted pour it into your rocket tube with a rod lined with paper in the middle to form the passage for the oxygen. The paper taped to the rod will make getting the rod out of the rocket once the tar has hardened easier and you can just burn the paper along with the tar when you fire the rocket.

[JKG317]

How did you fashion for nozzle?

[JKG317]

The nozzle.

[Rocketmang]

The nozzle is just a steel end plug with a hole drilled through it