Page 1 of 5

stupid 2 Stage rocket prototype design...

Posted: Wed Oct 08, 2008 4:25 pm
by Demon
I need your help guys to say me if this thing is going to liftoff or no...

The fuel who is going to be an mix of KNO3 and sugar and other ingredients

How it works:

1. fuse lighted, run away

2. fuel in stage 1 burn

3. the 2nd fuse burn

4. the fuel in the 2nd stage burn and blow the stage one away

5. The stage 2 fuel burn and lands on the moon :lol:

How high will it go?

(I would need an fuel recipe)

Evrything is made of pvc plumbing pieces.

Posted: Wed Oct 08, 2008 4:50 pm
by Fnord
You really have no idea what you are doing, do you?

Posted: Wed Oct 08, 2008 4:50 pm
by ramses
IMHO, you would loose any advantage of decreased weight caused by the drop away of the first stage with the mechanism used to deploy it. Seriously, go get some thin wall-steel or aluminum electrical conduit. the only problem is the nozzle and lack of badass-looking drop away 1st stage. if you used "all PVC", your possibly single stage rocket could drip away slowly, even if you used a metal nozzle.

Be safe, and be damn sure you don't have bubbles in the fuel.

Posted: Wed Oct 08, 2008 5:00 pm
by DYI
I need your help guys to say me if this thing is going to liftoff or no...

The fuel who is going to be an mix of KNO3 and sugar and other ingredients

How it works:

1. fuse lighted, run away

2. fuel in stage 1 burn

3. the 2nd fuse burn

4. the fuel in the 2nd stage burn and blow the stage one away

5. The stage 2 fuel burn and lands on the moon

How high will it go?

(I would need an fuel recipe)

Evrything is made of pvc plumbing pieces.

Oh dear...

Posted: Wed Oct 08, 2008 5:00 pm
by mark.f
Ditto _Fnord's remark.

EDIT - and DYI's.

Posted: Wed Oct 08, 2008 5:02 pm
by mrbadexample
i don't see anything that will stabilize this puppy, if it manages to lift off. i seriously doubt if you could run far enough or fast enough, if it decided to not go "straight up". it could start to "keyhole" on liftoff and pound itself into the ground without proper aerodynamics and a possible guidance system.

do you know the actual burn rate of potassium nitrate and your special "sauce"? and what is the burn temperature? you might end up with molten PVC flying around.

i vote Noo!!!

Posted: Wed Oct 08, 2008 5:35 pm
by Ragnarok
Oh dear. This is the kind of thing only a cat can truly explain.

And here we are:
Image

Apologies. I saw it a couple of weeks back and I've been wanting to use it somewhere...

Posted: Wed Oct 08, 2008 5:35 pm
by explsvcookie257
I could give you a recipe or ratios but it could possibley be used in other ways and is against forums rules I think. Oh and by the way as others have said pvc might not hold up but has anyone seen the model rocket engines they are made of cardboard but still I would use aluminum or something and if you do do this please pack the mix of kn03 and what not in really good becuase you dont want to get hurt from it doing other things but it most likely wont happen unless you use something else and i wont say what they are because that might give someone ideas. ohh and mods feel free to delete this if it gives away bad info lol. wait a second lol i have another idea you could use pvc you just need too line the outside walls with cat litter because it doesnt burn, like i said before i could give you a name of the right stuff but it will take people to sites that shouldnt be talked about on here.

I talk to much haha.

Posted: Wed Oct 08, 2008 6:04 pm
by mrbadexample
explsvcookie257 wrote:I could give you a recipe or ratios but it could possibley be used in other ways and is against forums rules I think. Oh and by the way as others have said pvc might not hold up but has anyone seen the model rocket engines they are made of cardboard
those rocket engines are just a few grams of powder in a thick cardboard sleeve, and are loaded for a "controlled burn". ramming a few kilos of stuff up a few large hunks of PCV is another deal :roll: .

estes made a nice little business in the 60's and 70's with them toy rockets (boy's life mags in the late 60's when i was a "scout") they are still around, but electric RC toys are now the rage.

i play with my fsX, even cheaper, crash and you lose nothing (had a nice death spiral today with a helicopter)

Posted: Wed Oct 08, 2008 6:50 pm
by Demon
Its me or now evryone is taking me for the last idiot?

:violent1:

Why?
Be safe, and be damn sure you don't have bubbles in the fuel.
I think i am really as what described Ragnarok...
(*Whispering very quietly*)what are you talking about?bubbles?

Posted: Wed Oct 08, 2008 6:57 pm
by Demon
do you know the actual burn rate of potassium nitrate and your special "sauce"? and what is the burn temperature? you might end up with molten PVC flying around.
No, i cant answer, and the rocket will be far until it melt, if it flies...

Posted: Wed Oct 08, 2008 7:05 pm
by rp181
tempetures are very high. On a stati test i did with a copper pipe with a reducer soldered on as the nozzle, it shot of. This was a crappy fuel misture too, it wouldn't even stay alight.

Posted: Wed Oct 08, 2008 7:14 pm
by Pilgrimman
I think what everyone is trying to say is that you are starting too big. You ought to research and do A LOT of pre-manufactures rocket tests so you have some hands-on experience. (I don't know if you do or not.) We don't try to insult. We are just afraid one of our members might hurt themselves or others.

Posted: Wed Oct 08, 2008 7:59 pm
by Carlman
Talk to the user watto, he has made and successfully launed dozens of homemade rockets using Kn03, sugar and variouis other thing that the outer casing was indeed PVC.

THEY GO BLOODY HIGH

but yea start simple then advance

Posted: Wed Oct 08, 2008 8:10 pm
by Lentamentalisk
Think about it like this:
Somebody new comes to spudfiles, and asks for plans for how to make a 30x hybrid, to shoot golf balls many times the speed of sound. Then they ask whether hairspray will work, and if ABS is a good chamber material.

Its like that, only with rockets. I suggest you read everything you can on the internet, then watch ever single KNO3 sugar rocket video you can find on youtube, then read the rest of the internet, and then study some basic aerodynamics (your rocket will not be stable in the least,) and then maybe consider making a rocket.

I am making a rocket, but I have been testing fuels on and off for a month now, and haven't even gotten to the point of sticking a nozzle on the end of the pipes filled with fuel, I am just trying to get a consistant mix.

P.S. Read a little on how rockets work on Wikipedia. You didn't even give your second stage a nozzle, and either the 2nd fuse will all ignite at once, because the whole area will be on fire, or by the time the fuse gets to the 2nd stage, it will have turned over, and then becomes a human seeking missile.



Do not do this project.