Rockets

[mr.evil]

Hey,
i was wondering, has anyone on this forum maked succesfull rockets? i mean, launched...
My experiences with rockets are that they go off the ground, but the stars doesn't get spreaded out. Mostly the top shoots off, no spectaculair effect.. please tell me your experiences with rockets/shells.

[Mr Ketam]

Can you give us more info on you rockets?

What kind of propelant, how much did you use, etc.
Maybe some pics?

See you later mr Evil...

[BrAiNFeVeR]

I've tried rocket, but they don't lift of or they explode :confused:
A buddy of mine has had better luck though.
Both of us used KNO3 + sugar + Sulfur (70/25/5 or something), though the highest he got was about 50 meters ...

These are rockets with solid grain propellant, no core burners or something.

[kingspaz]

do you have a picture or diagram? this would show infinately more than can be explained. then maybe we can help.

[EP]

So your problem is weak star spread right? If you are using the design of just a tube with engine and stars poured on top like these: (3rd, 4th pics down) <a href="http://www.geocities.com/extremepyro2/fireworksbuyersguide.html" target="_blank">http://www.geocities.com/extremepyro2/fireworksbuyersguide.html</a>

the stars will likely just shoot out the end. You could try containing them better with a wad of paper and glue or a glued in cardboard plug.

High end rockets use this design for aerial shell quality breaks:
<a href="http://members.aol.com/pyrosamm/rocket.html" target="_blank">http://members.aol.com/pyrosamm/rocket.html</a>

[vonK]

Last Guy Fawkes I made heaps of skyrockets (over 50).
I use home made black powder as propellant.
My biggest problem was rockets exploding on the ground though this was only about 1 in 10 rockets.
I used a clay end plug in my skyrockets with a tiny little hole going through into the delay. The hole was filled with very fine black powder and then I put about ten stars on top, added more black powder to fill in between the stars then glued a wad of toilet paper on top and put tape over the end.
Just about every rocket that went up made a dull "pop" and sprayed the stars out in no particular pattern. Not all the stars ignited either, only about half.
I built a three inch shell as well that had around 150 stars in it and home made black powder as burst. Only about fifty of these stars ignited but there was definetly a circular pattern at least.
I also built some Stinger Missle type rockets (the ones with the side vent for stability instead of a stick). I built 20 of these and every single one worked perfectly (except no star pattern).

[mr.evil]

hey,
i was experimenting this weekend with an rocket, with an salute payload(60gr KClO3/sucrose), it worked well..but maybe the engine was a little to weak, the distance it reached was about 20meters...
this morning, i was making an rocket with an 200gr. with about 80stars(SrNO3/KClO3/C/Fe dust) the engine is an BP one, it weights about 400grams, the burstcharge is 40gr. of Flashpowder(KClO3/C/Al 600mesh)..hopefully it will work!

EP: Thanks, i will try the shell-on-engine type.. i know they are beautiful(i had some of those rockets this year, buyed)
now i just have to know how to make some round shells :)

but anyway, has anyone some pics of his home-made rockets/shells?
thanx.

[vulture]

I make my engines of a piece of A4 paper cut in two and i roll one half over the other with glue between the layers. Then i wrap some tape around it, perpendiculary.
They mostly survive the burning propellant, even H3.
One slight drawback is that they are also excellent for firecrackers and they throw (harmless) shrapnel quite far in the event of an explosion.

Where do you get strontiumnitrate?????? <img border="0" title="" alt="[Eek!]" src="eek.gif" />

<small>[ March 18, 2002, 12:37 PM: Message edited by: vulture ]</small>

[mr.evil]

Hey,
do you use H3 in your engines??? <img border="0" title="" alt="[Eek!]" src="eek.gif" /> wouldn't dat explode?
i make my SrNO3 myself, i can buy SrCO3 in bags of 5kg. at the pottery stores, then i pour some HNO3 to it(about 12%, i can buy 20l cans 38%HNO3 for about 9$) to turn the CO3 into NO3....

Does anyone on this forum has Sodiumdichromate? what did you payed for it? i buyed last 1kg. of it, for about 7$..nice orange crystalls!

(sorry for my bad english)
Cya

[vulture]

Pressed H3(by hand), very fine, didn't explode, but almost took off without nozzle. Haven't tested with nozzle yet.
I am thinking of keeping them nozzleless and just make the engine exhaust smaller and smaller to the end. That way it there is no nozzle to eject. :)
Makes a neat roaring sound like a jetfighter. :D

The clue with H3 is: keep the engine diameter small, if you put some H3 on a pile, stick a fuse in it, light and run, you'll see what i mean. It has an amazing constant burnrate for such an energetic fuel.
The diameter off my engine is approx. 1-1,5cm i can stick a finger in it.

$7 for 1kg is quite good, i think acros sells 1kg for 17euro excl. VAT!
Would you mind sending me an email where you get all your chems, cause i visit the netherlands frequently... <img border="0" title="" alt="[Wink]" src="wink.gif" />

[EP]

Here are some links with info on spherical shells that would help for making rocket payloads:

<a href="http://www.angelfire.com/al/pyrotech/aerialshells.html" target="_blank">http://www.angelfire.com/al/pyrotech/aerialshells.html</a>
<a href="http://members.aol.com/pamatpct/buildshe.html" target="_blank">http://members.aol.com/pamatpct/buildshe.html</a>

I was sure I had more than that...if I find more I will post them. I also have a good book on fireworks I should scan that I think has spherical shell construction...

[a_bab]

Please scan that book EP ! How much do I have to pay you for this ? <img border="0" title="" alt="[Wink]" src="wink.gif" />

[mr.evil]

Hey,
Vulture; i will try the H3 method. Maybe add some tiny pieces of Mg for an nice effect.
i will send you an e-mail. Do you have MSN messenger?

Ep, Thnx for the Good info.

o yeah, here's a movie of an 1.5'' shell they worked well.
<a href="http://www.freakpyromaniacs.com/75.Mortiertje%201,5%20inch%20B.WMV" target="_blank">Shell</a>

now i'm going to make some shell rockets.
and offcourse, a pic;
<img src="http://www.freakpyromaniacs.com/m3.jpg" alt="" />

<img src="http://www.freakpyromaniacs.com/m195.jpg" alt="" />
1.5'' shell same from the movie

Cya!

<small>[ March 19, 2002, 04:36 AM: Message edited by: mr.evil ]</small>

[vulture]

Yep I have msn, vultureacs@hotmail.com. BTW, i speak dutch. <img border="0" title="" alt="[Wink]" src="wink.gif" />

Be careful with adding Mg, otherwise you'll have a hell of a firecracker. :D
Adding some extra charcoal or some bigger pieces of charcoal works nicely for sparks.
Ever tried Zn/S fuel?
I did, but the rocket went bang. Later turned out that it had gone airborne, but half the engine casing was blown away. Rather explosive takeoff, stunning and impressive... :D

[mr.evil]

No reason to be caraful with the Mg, because it are tiny pieces.
No, i had never tried the Zn/S fuel, i can't get Zn powder :( that's Really shitty because Zn can be used in beautiful fountains(blue electric fire), but i think Charcoal will also work for nice golden sparks. I have also several engine explosions in history, not the effect i was looking for(LIFT OFF!!! :) ) but the explosion is also very impressive, especially when the Payload explodes also(on the ground :D )

Well, Cya

[EP]

Another idea for easy shell building that I saw mentioned on rec.pyrotechnics yesterday:

<img src="http://store1.yimg.com/I/municipaltoy_1679_2078546" alt="" />

Plastic easter eggs! Just make a fuse/ignition hole in one end, fuse, fill and wrap.

[ALENGOSVIG1]

I bought a bunch of those at the grocery store a few fays ago. They work great for casings!

[mr.evil]

Well, that's a pretty easy way to make your own shells, i think i go look this afternoon for those easter eggs, how big are they?
Anyway, thnx for the tip! <img border="0" title="" alt="[Wink]" src="wink.gif" />

See Ya

[Jack Ruby]

Me and mine have been using those as casings for years.

They work great and come in different sizes.

How do you seal yours up? Hot Glue, Electricas Tape, Polyester Resign?

[mr.evil]

Hey,
as i said, i GO look for those eggs... :rolleyes:
but it hink i'm going to use Polyester resign with some hot glue for extra safety.

But anyway, i dont like the plastic shells very much(i guess),Paper with glue works better to me <img border="0" title="" alt="[Wink]" src="wink.gif" />

[ThaFreak]

Hey,

I am working on a couple of shells to.
Burst charge is KCLo3/sugar and I think they'll work great. :rolleyes: At the moment I'm working on the stars. Pic's will be posted. And if everyting goes o.k, maybe a little movie.

Cya,

Edit: nothing important, but "gr8" just looks kewl, so I wrote it out in full.

<small>[ April 08, 2002, 07:46 AM: Message edited by: Mr Cool ]</small>

[mr.evil]

how large will the shells be? what kind of stars are you going to use? TIP. Add some fine Al/Mg pieces to the stars, the result is an nice tail..

can't wait to see the pics :)

[HOOPS123]

Instead of drilling a core, could I use a wooden rod to set in place, then after it hardens, pull it out(this is with BP)? I think this would be easier for larger engines (A foot or more long).

[HOOPS123]

To make your rockets hard, do you guys use immense pressure or alcohol? W/ alcohol do you have problems with the mix drying?

[mr.evil]

i use Dextrin with BP, next i make it wet with some Aceton/ethyl alcohol(water sucks, it takes F*cking long until dried) then i press it into the paper engine casings, and put an Steel core in it.

no, i don't have any problems with driying, my engines are in about 1 day totally dry(room temp.)
only when i maded Ammonpulver, and wetted it with Methyl alcohol, it tooked about 2weeks until it was totally dry!! <img border="0" title="" alt="[Eek!]" src="eek.gif" /> after drying, the mixture wouldn't even burn at all...still i don't know the cause of this...

Cya

[HOOPS123]

Thanks. What does the dex do for it? How can you tell if its totally dried?

[vulture]

Dextrin is the binder here. If totally dry, the mixture will be brittle and if you scrape it with something there will be very fine particles coming off which don't stick together like in wet compo's.

[HOOPS123]

Ok, so how can you tell if the very bottom is dry, or somewhere in the middle. Is it the same as you said?

[vulture]

you can't be totally sure of that, just leave it on a hot (not too hot ofcourse :rolleyes: )spot for half an hour if you see the bottom is dry.

[nbk2000]

Methanol absorbs water from the air. That's probably why it failed.

[xoo1246]

Maybe I got this site from you, I can't recall. This is about sucrose/KNO3 rockets engines.
<a href="http://nakka-rocketry.net/" target="_blank">http://nakka-rocketry.net/</a>

[HOOPS123]

I read through Nakka's site. Its a very good site. One thing confused me and maybe you guys can clear this up for me. After melting the sucrose/KN03 together, you pour it in something for it to cool. If you plan on using a PVC pipe as the body, do you just pour it right in and let it dry for 45 min? Then after the 45 min take it out and let it dry? I read somewhere that it would expand. Wouldn't this expansion make it hard to put back in the pvc?

[Anthony]

The KNO3/sucrose is molten when your pour it into your casing, it then cools, solidifies and hardens, at whihc point it is "dry". Not that's it's "wet" at any point in the process.

[HOOPS123]

Heh. I see. I guess I just wasn't thinking. Won't let it happen again.

[mr.evil]

watch out with methanol, this stuff is f*cking toxic!

[PYRO500]

No, methanol is not really toxic unless you drink it in witch case I thibnk it is somewhere along 10 times as poisonous as ethanol, as long as you don't drink it then you have little to look out for

[Dhzugasvili]

I've made real rocket bombs before, First the engine and the shell are metallic. Welding the damn thing together and for the nozzle i have a metal lathe. SO i can fashion some pretty nice shells and engine. Usually my shells consist of 300g of RDX and a nicely fashioned nosecone. I used a firing pin at the top which transmits the shock to a glass ampoule inside the blasting cap filled with H2SO4, glass ampoule breaks, spilling sulfuric acid on some KCLO3/sugar powder (1g) igniting it virtually instantly, and this in turn ignites the primary within the blasting cap, this usually being freshly made AP or Mercury fulminate. Full detonation takes only a very slight delay between impact of the rocket with the target surface. :D below is a diagram. The nozzle escape angle is 15 degrees as compared to the conversion side of the nozzle which is 30degrees, then the nozzle neck, all made of fine, resistant steel and welded/screwed on. For a propellant I use ammonium perchlorate/rust/potassium perchlorate/Aluminium/and epoxy binder. this is then molded to fit inside the combustion chamber and a mold of a six point star formation placed within the still wet paste of rocket propellant so a six point star core is formed. this is filled with black powder for maximum instant ignition and more ISP developed in less time. The nosecone is also made of fine steel and has hole drilled in it for firing pin. i will upload diagram if people desire, even pic if i make one soon from now.

[Arkangel]

Pictures, pictures!

Dude, are you the guy that's been making the Quassam/Qassam2 rockets for the Palestinians? Sounds similar. They make 'em out of steel, power them with kno3/sugar.

<a href="http://news.bbc.co.uk/hi/english/world/middle_east/newsid_1816000/1816288.stm" target="_blank">http://news.bbc.co.uk/hi/english/world/middle_east/newsid_1816000/1816288.stm</a> :D

[Dhzugasvili]

Wishing not to drift off topic, eheheh, the Aluminum powder/ammonium perchlorate/pottassium perchlorate/rust/epoxy mixture i use for my fuel powers these sons of bitches up to amazing distances. I fired a rocket at this grain storage shack from 40m away and only a slight curve was produced in its flight path, and fuck the exhaust and the sound!! What a amazing sound and then of course, detonating on impact, an even more amazing sound and lovely bits of millet grain everywhere.... :D

[Cricket]

Dhzugasvili, I am really getting into rocketry now and so I am asking, how do you make your special propellant? Any special way to do it? And if you know, what was the mesh of the chemicals? Thanks. And to everyone, do any of you have special mixes you would share?

[NoltaiR]

I should definitlly say that I respect anybody that can make a rocket with a solid grain fuel that flies for more than 10 seconds.. I have tried to many times but I usually don't get much more than a few inches off the ground with my rocket before it decides it either want to blow up as is and shoot my casing (usually pvc coated with a fireproofer) everywhere or the nozzle will blow off and just spray my fuel out everywhere and not actually go anywhere.

[Microtek]

I have been experimenting with a type of gyrojet weapon because firearms are next to impossible to get around here.
The rockets consist of a short ( 2.5 cm ) piece of aluminium pipe with a wall thickness of 1 mm and an internal diameter of 10 mm.
I make a nozzle by plugging one end of the pipe with epoxy and drilling a 3.2 mm hole in this when it has hardened ( I use my metal lathe for this to ensure coaxiality ). I then use a small hobby drill to make two 1.2 mm holes on opposite sides of the main vent. These holes are tilted so as to impart spin to the rocket.
I then insert the ignition device which doubles as a coring tool through the main vent so that it extends about 1.5 cm into the engine ( beyond the nozzle plug ). I then fill the casing with a whistle mix that I extracted from common fireworks, and compress it with a tamping tool made from plastic. I perform this compression by hammering the plastic tool, and while I realise that pounding with a hammer is a bit brutal, I've never seen any hint that this mix is imact sensitive. Anyway, when the coring tool can no longer be seen, I seal the end of the rocket with epoxy or something similar. Total weight of the round is around 3-5 grams and when ignited, the burn is completed in less than 0.25 seconds ( conservative estimate ) and at the end of this burn, the rocket has been propelled about 30 m up.
The firing looks and sounds more like a recoilless rifle than a bottle rocket, and if you calculate the mean acceleration and top velocity, you'll see that it's quite usable as a smallarm.

[Dhzugasvili]

Here is my diagram but, alas i could not fit in the nozzle, the most important crucial part of the rocket that makes it fly.

-------- ---------------
\ \ \
\ \-----------------------| \
| | ______
/ | | ------
/ /------------------------- /
-------/ |_______________

Fins Engine Bomb firing pin

I make my propellant by mixing 70% ammonium perchlorate 19% aluminum and 1% rust. This is ground together in a mortar and pestle. This is made into a hardened mold after mixing with epoxy/hardener mixture into a thick paste and placed into the rocket combustion chamber and packed tightly. Then a 6 point star core borer is inserted with the anti agent for adhesive coated on it.Once the epoxy is completely hardened coring mandril is removed and voila, you have the rocket engine, assuming you've welded the fins on already and screwed/welded the nozzle with a converging section of 30degrees and a diverging section of 15 degrees. The core section diameter is calculated with a series of formulas and the mass of the propellant is also calculated, the nozzle throat area and diameter are also calculated based on the mass of the propellant grain, etc etc along with a hundred and one other calculations from everything to the ISP to the Nosecone angle, speed elevation, coasting distance, and number of fins and in which angular arrangement. Inside the core borehole, black powder FFF grade is placed, and the whole arrangement is ignited with a squib from which are connected the + and - wires of a battery. powder 400mesh aluminum is used here. ammonium perchlorate is ball milled and so is the rust if not acquired in that form.

[Dhzugasvili]

PS: the diagram didn't work, its a piece of shit, ignore it please, i suppose i could always draw it, scan it, and post it, but i was just feeling lazy, if folks want me to put the diagram, i will.

[HOOPS123]

So far in my designs the nozzle convergence and divergence is the toughest part to complete because I have no access to any type of welding. So far the best I can come up with is two metal funnels, placed end to end and cut to the desired length, and set in cement. Finding the proper 15, 30 degree angles may be impossible though.

[kvitekrist]

me and my friends have made a few rockets that actualy worked.

I use sodiumclorate/sugar mix, packed hard in to an paper rocketbody with wood nossels and are stick stabilized.

video of one that worked:

<a href="http://home.no.net/gjalring/sp/rakettsuksess.WMV" target="_blank">http://home.no.net/gjalring/sp/rakettsuksess.WMV</a>

ones that failed:

<a href="http://home.no.net/gjalring/sp/rakettidass.WMV" target="_blank">http://home.no.net/gjalring/sp/rakettidass.WMV</a>

<a href="http://home.no.net/gjalring/sp/rakett.wmv" target="_blank">http://home.no.net/gjalring/sp/rakett.wmv</a>

[kvitekrist]

hmm i'm not realy sure..

I think it is pure..

it says something like "grass remover".. it is an old pack.. probably about 10 - 20 years,

got it from an old farmer... heh

[HOOPS123]

"October Sky" all over again. Thats what the last two rockets remind me of :) . Im pretty sure they used that propellant too.

[NoltaiR]

To the guy with the screwy text diagram:

use the opening HTML tag < pre> before you start making your diagram and the closing tag < /pre> . (just leave out the spaces in the tags)

[nbk2000]

Man, you guys are having too much fun with those rockets! <img border="0" title="" alt="[Wink]" src="wink.gif" />

In the "rakett" video, I have to wonder what the neighbors thought about all the smoke?

BTW, really pretty country you live in. My mothers side of the family is from Trondheim (SP?), pre-WW2.

<small>[ April 14, 2002, 03:52 AM: Message edited by: nbk2000 ]</small>

[inferno]

Heres an excellent site on how to make rockets(uses KNO3,Sugar,Sulfur):
<a href="http://www.alphalink.com.au/~brucej/nickle.htm" target="_blank">http://www.alphalink.com.au/~brucej/nickle.htm</a>

[kvitekrist]

>nbk2000

yes we are having fun!

and the neigbours dont care... heh

here in this open farmland country nobody cares..

heh.. Trondheim it is.

i live in the southern part of the land

[Dhzugasvili]

how do i put in pics or a diagram in a reply? I upload it to the forum, yes i know, but how do i do THAT?

[Guerilla]

Here´s some pics from my KNO3/sucrose rockets..

Propellant was rammed into the cardboard tubes (15cm x 17mm, wall thickness was about 3mm and the nozzles were 6mm).

Some of those rockets flew over 200 meters. There were no payloads with...

<img src="http://www.pyroteam.netfirms.com/r10.jpg" alt="" />
<img src="http://www.pyroteam.netfirms.com/r2.jpg" alt="" />
<img src="http://www.pyroteam.netfirms.com/r3.jpg" alt="" />
<img src="http://www.pyroteam.netfirms.com/r4.jpg" alt="" />
<img src="http://www.pyroteam.netfirms.com/r6.jpg" alt="" />
<img src="http://www.pyroteam.netfirms.com/r7.jpg" alt="" />
<img src="http://www.pyroteam.netfirms.com/r8.jpg" alt="" />

Hope i didn´t flood very much :D

<small>[ May 14, 2002, 01:35 PM: Message edited by: Guerilla ]</small>

[xoo1246]

Good job, and nice pics.

[mr.evil]

Very Nice Guerilla!

I've did an static test this morning, it was amazing how much power a Blackpowder/Al rocket has!! once i was scared the engine would blow up(huge engine Noise) <img border="0" title="" alt="[Eek!]" src="eek.gif" />

this weekend i will launch some rockets... <img border="0" title="" alt="[Wink]" src="wink.gif" />

Hopefully they work so i can show you the pics, to bad i have no digital cam so you'll have to wait for development.

anyway, i love rocket engines with tiny pieces of Magnalium or Iron fillings, nice tail!! i'm looking hard to get some Sb trisulfide, so i can make even beautifuler tails!(twinkles or whatever, i mean those flittering white lights...)

[xoo1246]

I did a test with a cored bp rocket toady, 2 mm nozle exit, I pressed the bp damp with some ethanol, and I couldn't wait until it was dry, I guess thats why it didn't lift off. <img border="0" title="" alt="[Wink]" src="wink.gif" />
The ignition charge lifted the rocket one meter, then it dropped and the bp burned without propeling the rocket anywhere(it was stuck behind a little pile of soil too). The blackpower wasn't of very high quality, but good enough since another one exploded with dry pb in it(but no core). Doesn't Al/BP erode the nozzle very fast? Propably not fast enough. And since it's only single use, it doesn't mather.
Has anyone used shellac as a binder? results?
I have some Ammonium perchlorate, maybe better for rocket fuels. :p

[DBSP]

Guerilla what ratios did you have for the propellant?
Nice pics btw :)

[SATANIC]

I refuse to go through all my failures, a combination of misfires, explosions, and duds. The best of mine was a KNO3 / sugar that went about a metre before it blew up. I think it was something to do with bubbles forming in the mix. (supposedly a common prob)

Overall i think the nozzles were to blame, as i used the same batches of propellant, with very varied results...

So, has anyone tried nozzleless rockets? they sound easy enough, i'll do some more reserch in the meantime...

[mr.evil]

I know that moontravellers(that little rockets) don't have a choke/nozzle so it has to be possible with bigger rockets too! i will test it this evenening, hopefully they work well because my nozzles shoots out most of the time(pressure) :rolleyes:

[kvitekrist]

I use wood nozzles, they are easy to make and cheap!

I make my own paper tubing and use only wood plugs and seal with hotglue.

[Guerilla]

I used basic 6/4 ratio (KNO3/sucrose), the optimal ratio would be 65/35, but my scale isn´t accurary enough (1g) with a small amounts..

The most easiest, fastest and safest way to make rockets is to use a rammer and a spindle. My rammer(aluminum) is made with lathe, but the spindle is made my sticking an aluminum rod in a tin can full of cement (not very impressive.. <img border="0" title="" alt="[Wink]" src="wink.gif" /> )

The kitty litter(bentonite) is good stuff for the nozzles (cheap and easy to ram). And if the pressure rises too high, the nozzle breaks instead of the casings. That´s good thing especially when you´re using PVC or other non-cardboard tubes which can throw nasty shrapnels.

Here´s my poor rocket set:
<img src="http://www.pyroteam.netfirms.com/r11.jpg" alt="" />
Ramming the propellant:
<img src="http://www.pyroteam.netfirms.com/r9.jpg" alt="" />

[Anthony]

I'm sure I have made nozzleless, core-burning KNO3/surose motors before, I don't remember using nozzles and they flew fine with the core primed with a pinch of black powder.

[Arkangel]

Nozzle-less rocket links. I'm sure I've posted these before, but here you go again, comps, tooling, etc etc. I especially like the blue strobe technique:

<a href="http://www.angelfire.com/nv/bpnozzlelessrockets/index.html" target="_blank">http://www.angelfire.com/nv/bpnozzlelessrockets/index.html</a>
<a href="http://www.angelfire.com/nv/bpnozzlelessrockets/page3.html" target="_blank">http://www.angelfire.com/nv/bpnozzlelessrockets/page3.html</a>
<a href="http://www.angelfire.com/nv/bpnozzlelessrockets/page5.html" target="_blank">http://www.angelfire.com/nv/bpnozzlelessrockets/page5.html</a>
<a href="http://www.angelfire.com/nv/bpnozzlelessrockets/page4.html" target="_blank">http://www.angelfire.com/nv/bpnozzlelessrockets/page4.html</a>

And one for those starting out:

<a href="http://www.alphalink.com.au/~brucej/nickle.htm" target="_blank">http://www.alphalink.com.au/~brucej/nickle.htm</a>

I've spent a fair bit on fireworks recently, and have a selection of roman candle tubes that I plan to convert to rocket bodies. I'm thinking of casting nozzles with plaster of paris - anybody tried it?

<img border="0" title="" alt="[Wink]" src="wink.gif" />

[xoo1246]

I have been experimenting with small BP rockets for a while.
Core burners in plastic pipe with PVC nozzles.
Since I have access to ammonium perchlorate(AP in this post) I'm planing to test a AP/Al/PVC engine when I get my ball mill and some milling media.
Dhzugasvili: When you casted your engines, how do you avoid bubbles in the cast?
Here is some pictures of a protype nozzle, it should be longer and maybe contain some internal steel parts in the core to avoid too heavy nozzle erosion. Maybe one could add Al (or dry, milled clay powder) to the PVC in the nozzle to make it more heat tolerant, what do you think?
Here are the pictures:
<a href="http://w1.478.telia.com/~u47802930/nozzle01.jpg" target="_blank">http://w1.478.telia.com/~u47802930/nozzle01.jpg</a>
<a href="http://w1.478.telia.com/~u47802930/nozzle02.jpg" target="_blank">http://w1.478.telia.com/~u47802930/nozzle02.jpg</a>
<a href="http://w1.478.telia.com/~u47802930/nozzle03.jpg" target="_blank">http://w1.478.telia.com/~u47802930/nozzle03.jpg</a>

<small>[ May 25, 2002, 12:01 PM: Message edited by: xoo1246 ]</small>

[vonK]

Hi guys.
I've been wondering for awhile now about the use of zinc in rockets.
I have never owned any zinc dust but can get it quiet cheaply and I have a few questions

Number one. Does anyone have any experience with zinc sulfer rockets (micrograin)? I can't find a bloody thing on the net.
I was thinking of ramming it in to a cardboard tube (with core) and then placing that inside a PVC engine casing, kind of like the PVC motors on Nakka's site. Does this sound feasible?

Number two. What sort of effect would zinc dust give to the tail of a BP rocket?

Number three. Could I use loose zinc sulfer mix as a payload in skyrockets to give a report?

Finally, number four. Can zinc be used in flash powders instead of aluminium, specifaclly KMnO4 flash? I can't easily get Al powder.

Thanks for any help
Kurt

[mr.evil]

</font><blockquote><font size="1" face="Verdana, Arial, Helvetica">quote:</font><hr /><font size="2" face="Verdana, Arial, Helvetica"> Hi guys.

Number one. Does anyone have any experience with zinc sulfer rockets (micrograin)? I can't find a bloody thing on the net.
I was thinking of ramming it in to a cardboard tube (with core) and then placing that inside a PVC engine casing, kind of like the PVC motors on Nakka's site. Does this sound feasible?

I've made an Zinc rocket once, but it didn't go up very well(only 2 metres, the nozzle shooted out) I get my Zinc from my Uncle(he works in a paintlab, sigma coatings)

Number two. What sort of effect would zinc dust give to the tail of a BP rocket?

Lots of smoke, and if dark nice green/blue colors

Number three. Could I use loose zinc sulfer mix as a payload in skyrockets to give a report?

My Zinc/Sulfer doesn't burn fast, so i don't think it is suitable for reports... I know you can make nice stars with Zinc(see also the Zinc spreader star, from Wouter visser's page)

Finally, number four. Can zinc be used in flash powders instead of aluminium, specifaclly KMnO4 flash? I can't easily get Al powder.

as said above, my zinc doesn't burn fast. But maybe in combination with strong oxidizers it does...

</font><hr /></blockquote><font size="2" face="Verdana, Arial, Helvetica">

[Rat Bastard]

</font><blockquote><font size="1" face="Verdana, Arial, Helvetica">quote:</font><hr /><font size="2" face="Verdana, Arial, Helvetica">No, methanol is not really toxic unless you drink it in witch case I thibnk it is somewhere along 10 times as poisonous as ethanol, as long as you don't drink it then you have little to look out for</font><hr /></blockquote><font size="2" face="Verdana, Arial, Helvetica">You might like this little story...he...he
<a href="http://www.DarwinAwards.com/darwin/darwin2001-22.html" target="_blank">http://www.DarwinAwards.com/darwin/darwin2001-22.html</a>

This may sound silly, but does anyone know the best brand of kitty litter for pyro uses?

[PYRO500]

I don't think it really matters what brand you use as long as it doesn't have other crap in there and is just bentonite.I have reason to believe the darwin awards site makes up alot of their material I know for one that labratory grade alcohol besides being highly regulated in pure form (unless you pay the tax) and the high concentration of alcohol would make it down right undrinkable, pure ethanol even straight from the bottle would make you spit all over the place.

[andreas]

he could have mixed it with tapwater to make it drinkable

[Mick]

woo. just made my first KN/sucrose rocket, very sweet indeed =D.
it was by accident too.

i'd been having trouble getting them to ignite properly(didn't have any BP to ignite the core completly, so none of them would take of properly). it was my last one, and i hit it with the blowtorch right up the core and whooosh! off she went..did about 5 loops around my back yard, then flew off into the night sky bout 100m in the air.

it was made in a metal tube about 1' diameter, 5 inch long. with an endcap and nossle made from car putty(bog, resin..whatever) each piece about 1/2 inch thick. it a was dry mix(ie. not candy) of about 60/40 (KN/Su)

needless to say, i was pretty stoked at the time :D

<small>[ June 14, 2002, 11:48 AM: Message edited by: Mick ]</small>

[Anthony]

Off topic but I think I should point this out just incase anyone decides to try it - methanol and water is not drinkable!

[VX]

I think people are realy underestimating the toxicity of Methanol. Although methonol itself is almost completely harmless it is broken down in the body by the same enzymes that eliminate ethanol.

It is eventualy oxidised to CO2 and water, but it is first changed into methanal (formaldegyde) and then into methanoic acid (formic acid) These chemicals are extreemly toxic and formic acid also attacks the eye and cases blindness.

Take a look at this site <a href="http://csf.colorado.edu/envtecsoc/2000/msg00541.html" target="_blank">This site</a>

[xoo1246]

I found a small container of methanol at my work, it sais skin contact can be very harmfull too.

[Purple Fire]

Im not sure that theyd come under the category of pyrotechnical rockets, but my friend and i used to make small flash powder rockets. They were made out of metal AA battery cases which are convieniently open at one end, and sealed off very well at the other. They had a KMNO4/Al/S standard flash mix in them and a bamboo skewer to stabilise them. The mix was pressed in firmly along with the fuse and then there was a clay plug pressed into the end to hold the mix in, but not pressed hard enough for it to provide any confinement. They went with anywhere from a bang to a short but intense whhooooossshhh and by god did they go for miles!!!! we never tried with a charge at the top of any kind as timing it would be incredibly difficult because you cant use the slow brning rocket fuel as a timer. I have borrowed some time fuse from some dismatled firewroks and intend to try one with a charge at the top sometime soon.

<small>[ June 15, 2002, 05:17 AM: Message edited by: Purple Fire ]</small>

[Mick]

how do guys ignite your rockets?

i've seen a few sites and they fill the core with some gunpowder that way it will ignite the all of the core.
unfortunatly, i haven't got any gunpowder.

what else can you use?
i have been trying to think of some to pack into the core all day that is fast burning. i tried a little bit of flash (KMNO4/al/S? - not sure if there was any S) and when it ignited it busted the core, and it didn't take off.

one site i saw said to ignite the top of the core, that way it will ignite all the way down the inside. i tried that, and the rocket took off, but the hole i made for the fuse to ignite the top acted like a nossle and pushed the rocket over so it nose dived back into the ground.(i tried putting it thru the top, but that made the rocket spin around on the ground.)

[Microtek]

When making ( small ) core burners I have found that if you leave the coring tool in the core, and have previously placed a bridgewire at the top of the tool, then when the bridgewire ignites the top of the core, the pressure pushes the rocket off the tool and ignites the rest of the core as it goes. This worked excellently with 10 mm spin-stabilized rockets fired from a launch tube. They were propelled by some sort of whistle mix ( extracted from commercial fireworks ) and were bullet fast.

[Anthony]

KMnO4 flash should work for priming the cores, it's faster than the homemade BP I've used with success. When you say "pack into the core", how much are you putting in? I found a pinch, which probably filled the core less than 1/10th did the trick.

[Mick]

i wasn't packing it in, just pouring a little in, then putting a little bit mixxed with water over the nozzle to hold it in and allowing it to dry.

however, i think i have come up with a better way
i found that putting fine steel wool(not course) accross battery terminals(car 12v battery) may work. its pretty weird tho, i found that if you place the to wires-which are joined with about 2 inches of fine steel wool, twisted up to make "turd" about the thickness of a pencil lead- accross the battery terminals, nothing happens, but if you take one of the wires off, then put it back on the battery quickly, the fine steel wool goes "foomp!" and sparks(breaking in half), then it will glows read for atleast 30 second, in which time is reliably hot enough to ignite KN/Su.
the only thing i don't understand is why you have to touch it on the battery twice..hmmm just one of those things i suppose.

i had some course steel wool, and i tried using a could of strands however it didn't reliably ignite the KN/Su everytime (as opposed to the fine stuff, which did for upto 30 seconds after it came off the battery)

i've gone a little bit further tho, i coated a few wads of steel wool last night, one was coated with KNO3 and acetone, another with KN/su and acetone, and another with KN/C...interesting to see if any of it made a diffence..probably not, but it won't hurt

<small>[ June 15, 2002, 09:07 PM: Message edited by: Mick ]</small>

[Mick]

well..turns out my idea with fine steel wool doesn't work as well as i expected.
it appears that it will ignite a pile of KN/Su, however when in the core of a motor it will not ignite them properly so it wastes half is fuel igniting the rest of the motor.

so back to the drawing board i suppose.

another question, what is activated charcoal?. one recipe i saw for igniters was to combine KN/Activated charcoal in NC lacquer, then coat some nichrome wire with it. would you find activated charcoal in the charcoal art pencils? (there just solid rods of charcoal...messy as all fuck too, they get black shit all over everything)
i am assuming that you can't just burn some timber and then scrape the charcoal of it and use that? (cause that would be too easy)

<small>[ June 16, 2002, 12:15 AM: Message edited by: Mick ]</small>

[green beret]

I found that sparklers can be used to ignite rockets reliably, you need to cut the wire off where the composition begins, and then carefully put the sparkler into the nozzle of the rocket. I did this using estes rockets many years ago, also when the rocket ignites the sparkler just falls away.

This worked for me on estes rockets so it may not work for you, just something for you to try anyway.

[inferno]

Sparklers light anything...they burn really hot, visco is probably better because of its flexibility however, though wrapping a sparkler in masking tape makes it reasonably flexible...

Anyway in my experience, KNO3/sucrose is really easy to ignite, it takes a small spark to ignite it, so using any kind of fuse or sparkler will light it every time. Just stick a sparkler up the nozzle and light the end of it

[Mick]

unfortunately sparklers do not work, well it does but its a complete waste of fuel. you need to ignite the all of the core in one go and sparklers burn to slowly to do it. so by the time you acctualy get enough thrust to get going more then 50% of the fuel has burnt away, which means reduced height..and its way boring to watch - thus = gay.

however, i did a quick test tonight of a single strand of copper wire dipped in KN/Mg(300mesh) and epoxy(join the dots people, its 3am and i can't be stuff explaining the whole thing..i might take some pics tomorrow)
and it worked like a fucking charm. i touched the wire on a car battery and BAM instant thrust, the motor which i had in a 6m length of PVC pipe with one end butted up against a wall(for safety, cause when the rockets don't ingite properly, they don't fly straight which is to dangerous cause both my neighbours live pretty close, and i had close shave with next doors window this arvo) flew down the pipe and smashed into the wall, desintergrating the motor on impact.
from the time i touched the wire, to the time it hit the wall was like .2 seconds, i didn't even get to see it. now if i had used a sparkler, it would have sat in the pipe for a good 5 seconds before it even thought of moving..thats if it bothered to move at all.(the more surface area you ignite in one go = more thrust. however the quicker you burn thru your fuel, but that can be counter acted with two stage motors etc etc. but for time being i just want a reliable way to ignite them. )

i'll do a couple more tomorrow to see if it will work again or if it was a once off fluke type thing.

one thing i'll have to figure out tho, is what set my epoxy off so quick. normaly araldite(2 part epoxy) will stay workable for about 10 to 15 mins. this arvo when i made my igniters, the epoxy only just lasted 2 minutes - i only got to make three igniters, and by the time i put the 3rd one down, and picked up the 4th to dunk it, the epoxy had set rock hard...which to me, is really fucken wierd. i assume it has something to do wtiht the KN...dunno, look into it further tomorow

anyways, going to bed...

<small>[ June 16, 2002, 12:52 PM: Message edited by: Mick ]</small>

[Zambosan]

I imagine the oxidizer helped to crosslink the resin. As far as "double-touching" the steel wool, I think it's part luck... you need to complete a circuit on only a few of the strands for them to burn from resistive heating. Complete a circuit through the whole "turd" and you've got so many parallel paths to ground that the current will be divided (per Kirchoff's current law) to the point where it does not exceed the carrying capacity of each strand, hence no heating to the point of ignition.

[inferno]

Sparklers will only light solid core rockets, not core burners. Gunpowder is obviously the best to ignite the whole core, but two others things you could use if you dont have BP is armstrongs mix from toy caps, or even safety match heads, they wont be as fast as BP but they will ignite it relatively well. 10cm of sliced match heads can burn confined in about .25-.5 seconds, fast enough to launch the rocket.

Another question, has anyone tried making rockets from matches? I think it would work but would be tedious work to cut up the matches

[Microtek]

Having some kind of diaphragm or other light containment will get the gases in the core hot enough to ignite the entire length. It will also raise pressure and combustion rate, so your rocket will be accelerated a bit more.

[Flake2m]

Why not use rocket igniters?
Just place one at the top of the core burner
with a bit of BP for good measure.

[Mick]

because model rocket igniters are to friggin expensive to use regularly.

and if i had BP, i wouldn't use MRI's in the first place.

[0EZ0]

Mick, why don't you just use a KNO3/C to prime your rocket core?

This mix is basically sulferless BP, and burns qute alot quicker than normal BP. One of the characteristics of Sulferless BP is that it produces less gas when it burns, making it less prone to tearing up your rocket fuel if used as a prime.

If this mix does not burn hot enough, add some Al powder.

[xtreme]

Succesfull (little) rocketlaunche !

My first one (with nozzle/without sulphur) say's: BOOOM !
My second works (flying) very well <img border="0" title="" alt="[Wink]" src="wink.gif" />

Second one: I used blackpowder (with sulphur).
This time without nozzle
I insert a smaller aluminum pipe in a 5/8" PVC pipe and fill the PVC pipe with some blackpowder, stamp it, some drops NitroCellulos-Lacquer to hard te blackpowder......some blackpowder, stamp it,.......

When the pipe is totaly filled with blackpowder..I removed the smaller aluminum pipe. Because I hardend the BP with some NC-Lacquer I have now a nice hole in my rocketfuel :)
Close the top end....made a simple launcing setup.
and...GO !

I will make a another one....perhaps with a AP charge on the top of the rocket for a nice boom in the air.

If some people interested....I can post some pictures of the procedure/tools I used.

[kingspaz]

elight, DO NOT TRIPLE POST CRAP! , use the edit function. also don't post crap. read around the forum for a couple of weeks before posting again.
also learn how to spell properly. 'you' DOES NOT equal 'u'.

[mr.evil]

xtreme, cool that your rocket worked! Did you used a stick or just some fins(like real rockets) to stabilize?

</font><blockquote><font size="1" face="Verdana, Arial, Helvetica">quote:</font><hr /><font size="2" face="Verdana, Arial, Helvetica"> If some people interested....I can post some pictures of the procedure/tools I used.

</font><hr /></blockquote><font size="2" face="Verdana, Arial, Helvetica">i'd like to see those pictures :)

[frogfot]

Hi, got my two 90gram KN/Dextrose (melted) rockets in front of me and one 40g "dude". I used to ignit all my rockets with fuse (KN/sucrose in coctail straw) and couple of grams powdered KN/s in the core, worked every time.
But now it's only electrical ignition, instead of running like hell i can take pics from my hiding place :cool:
I myself like soft starts and don't really see any big advantages with simultaneous ignition of whole core. I think 1 meter rod will be enough to accelerate KN/sugar rocket that is &lt;1kg, maby even bigger...

[xulus]

I tried making end burning KNO3/Sucrose rockets (following the design on <a href="http://huizen.dds.nl/~wfvisser/EN/D3_rocket_EN.html" target="_blank">Wouter Visser's page</a>, his D3 rockets, but leaving out the core) but they didnt work well, they took off but hovered about 50cm above launch height before diving into the grass. I havent had any explode/push out endplugs/ be massively unstable though, which is encouraging, although this could be to do with not enough pressure of course..

I don't have a ball mill to make fast enough BP to fill the cores, but I'm gonna try powdered safety match heads as they at least burn faster than BP I made with pestle and mortar.. :rolleyes:
testing tomorrow

[Yi]

Ahh good to see you here Xulus :) How did those weights turn out?

[0EZ0]

I while ago i posted that it is possible to use Sulferless BP to prime rocket cores, but did not post the procedure.
So as the procedures were no where to be found either in the archives or from past topics, i post them <a href="http://www.roguesci.org/cgi-bin/ewforum/ultimatebb.cgi?ubb=get_topic;f=3;t=000391" target="_blank">here</a> , for anyone who is interested.

0EZ0

[Guerilla]

I´m not sure if someone else has already said this but why should you fill the core with bp or any other prime? I´ve used to just roll some paper or foil around the fuse (of course leaving the both ends naked) and stick it to the core. When the burning fuse reaches the top of the core, the core starts to burn inside out, igniting the whole core kinda fast. Or if using electric ignition, just place it at the top of the core.. If the propellant is fine, properly mixed and the nozzle is ok, you´ll get a pretty powerful rocket.

But still core burners might be a bit impractical, if one would really like to send a rocket high.. the problem is that the burning area increases all the time(progressive burning), that means the nozzle have to be ineffective most of the burn time otherwise it´ll blow out.

There´s a good solution for this problem, called "bates grains". The whole idea is that the burning are stays the same (well.. almost) all the time. They call it neutral burning.. More the burn area inside the core increases, as more it decreases from the ends of the grain(s) if you know what I mean <img border="0" title="" alt="[Wink]" src="wink.gif" />

I´m bad as an explainer so check out these:

<a href="http://www.jamesyawn.com/Bates/index.htm" target="_blank">http://www.jamesyawn.com/Bates/index.htm</a>

<a href="http://www.triton.ch/spl/software/Grains2/Grains2.zip" target="_blank">http://www.triton.ch/spl/software/Grains2/Grains2.zip</a> (the .hlp file)

One advantage is also that you don`t need any special tools for making them and you can prepare many grains at a go, albeit a minimum grain diameter seems to be about 3cm (1 1/5").

I´m going to test one someday when I got time and see how far it goes :rolleyes:

[Arkangel]

I do this all the time. I read through a thread, thinking, "what they need to do is THIS", and then the very last post is what I was going to say.....ARSE.

Well, Guerilla said it, I'd be inclined to use Quickmatch to light my core burners, and that's what I'll be trying this weekend. For anyone new out there, quickmatch is simply a BP/string fuse encased in a paper sleeve. That way the fire is transported through the sleeve in an instant. The quickmatch I buy burns at about 50m/second. You'd only need as much as the length of your core, with your igniter fastened in the end of it. That way you have a hot flame directed right to the top of the core.

Commercial rocket igniters are not only too expensive, but also too short. Estes motors don't seem to have a core, and their igniters are only 1/2" long. iirc Nakka has some info on this, as does this guy <a href="http://www.angelfire.com/nv/bpnozzlelessrockets/index.html" target="_blank">http://www.angelfire.com/nv/bpnozzlelessrockets/index.html</a>

Edit: btw, Skylighter do this stuff: Lampblack, Conductive

[C] Black powder

Used to make bridge-wireless electric matches.

Any idea how it works?

<small>[ November 04, 2002, 06:32 PM: Message edited by: Arkangel ]</small>

[static_firefly]

I use kno3,sugar 75gram-50gram. With a rocket around 6inch long (not including a guide rod) i get a range of what i estimated to e at 400m but because im not very good a geussing i say they fly 300m. I have a movie as proof too if anyone wants it. its not the best, shit really but its still a movie.

[Korfaction]

With these proportions you don't have problems of impurities sticking into the pipe and slowing the gas emissions ? (And possibly makes the engine explode then). there's much sugar !

[Guerilla]

</font><blockquote><font size="1" face="Verdana, Arial, Helvetica">quote:</font><hr /><font size="2" face="Verdana, Arial, Helvetica">
I use kno3,sugar 75gram-50gram. With a rocket around 6inch long (not including a guide rod) i get a range of what i estimated to e at 400m but because im not very good a geussing i say they fly 300m. I have a movie as proof too if anyone wants it. its not the best, shit really but its still a movie.
</font><hr /></blockquote><font size="2" face="Verdana, Arial, Helvetica">Could you tell us more specific dimensions of your rocket, I think with that much of fuel, it´s possible to get it a lot higher depending on the gross weight.. And yes, movie would be nice :)

[static_firefly]

ok the way i build my rockets may seem a little weird to you people but they work every time. in fact, i dont even melt the fuels, i have never liked the sound of that

I bought a broom handle from the store. $2. I cut 2 half inch peices off and one about 6 inch.. Then i drilled a a core up the middle of the 6inch about 1/3rd the width. I stopped the hole about an inch from the end. For the rocket tube i cut some cardboard from a manilla folder and wrapped it around and secured it with sticky tape. with one of the small half inch bits of wood i drilled another 1/3rd hole through it. then with the aid of PVA glue i stuck it in the bottom. after about 5mins i stuck a bolt in the bottom and poured the powdery kn sugar mix. With the 6inch wood i hammerd the fuel down. i kept this up until it was full but with enough room for the other plug. i glug that in and wait over night.
For a tale i stick 3 bamboo skewers togther (2 next to each other and one out the end) and stick it to the rocket.

For a fuse i use the same rocket fuel mix. i get some cling wrap, about 5inch by 5 inch and stick it to the table. then i pour some fuel onto the wrap and roll it up ( i found sticking it to the table stopes it slinding around). The fuse will burn compleatly submerged under water. I stick it in, plop the tail into a small pipe for a guid and fire it. I dont prime it.

Also i got no where to put the movie and pics so if u want it il have to e-mail it or something

Oh yeah and when i said i use 75g to 50g (kn-sugar) i didnt mean i use it all in one rocket, there just nice ratios for me to remember.

<small>[ November 06, 2002, 06:52 AM: Message edited by: static_firefly ]</small>

[Sparky]

mainly @ Korfaction:
Has anyone ever had a rocket that they think blew up because of this? Because this theory seems strange to me. The residue from the rockets is very hot, and iether a vapour, dust or hot liquid, so how could it block the nozzle? It would have to be solid like a rock or something. I seriously don't think this failure mode is a problem.

[Arkangel]

An incorrect mix of Saltpetre and sugar will produce a load of black shit, or slag, so it's not unusual to see nozzles clogged up. Never had an explosion with it though

[Marvin]

To get the best thrust from your fuel the pressure inside the rocket should be just below the pressure that will cause your rocket to rupture. (Steady state aproximation). This is exactly the same as a car engine, except the limiting factor is the preignition of the fuel/air mix rather than the strength of the parts. Larger compression ratios make better use of the fuel, and diesel engines with a higher ratio do better than petrol engines or jet engines at converting the chemical/thermal energy to motive power.

The more reliable the fuel, the better you can tune the pressure in the rocket without getting ruptures due to burning spikes. The choke is what limits the pressure and in the classical thermodynamic model is what converts the pressure into thrust. Its designed for the normal exhaust viscosity which is mainly hot gas and dust/liquid droplets. If you get a blob of anything trying to go through the nozzle its viscosity/inertia is much greater and you get a huge pressure spike.

Even though its quite liquid and pliable, its mainly the inertia it experiences in the attempt to accelerate it to the exhaust gas velocity compaired to the normal exhaust that causes the problem.

If you are satisfied with the rocket leaving the ground with no payload, and if you are using sugar mix you have to be, then youve probably never had this problem. Rockets are a real pain to fine tune, even with a good fuel mix. Making the fuel mix extremly reliable and consistant from batch to batch, and tweaking the chokes experimentally is the secret of good rockets IMHO. Something I am still very much working on.

[Guerilla]

Taking into account how cheap, safe and still quite useful KNO3/sugar rocket propellant is.. you certainly don´t have to be a satisfied with only payloadless rockets. The rockets I´ve made (25g of fuel) can take 50-100g charges up to 150 meters, maybe higher.. Even 500g lifts up from the launch tube <img border="0" title="" alt="[Wink]" src="wink.gif" />

The sugar rockets are really great fun when got no better things to do.. Once I made a couple of end burning "torpedos" and tried to launch them underwater from a two meters long pvc pipe..

<img src="http://pyroteam.netfirms.com/torp1.jpg" alt=" - " />

<img src="http://pyroteam.netfirms.com/torp2.jpg" alt=" - " />

<img src="http://pyroteam.netfirms.com/torp3.jpg" alt=" - " />

As it might be seen, it didn´t work very well.. just splashed on the surface..

When I tried the same trick with a core burner, it bounched from the bottom through the surface and almost hit my head :D

Maybe it´s a too crazy idea to launch rockets underwater, at least the rocket would have to be a heavier and a more powerful than those are... Wish I had the chems for the composite fuel..

[Nika452]

Cool pictures!
I wouldn't think the propellent would have to be too powerful, because the torpedo would not have to travel as quickly through water as through air to remain stable...although the increased density of water could be a problem. The increases inertia of the water being pushed aside obviously slow down the rocket/torpedo.
It doesn't look like you used and stabilization method, or am I just missing it? How heavy was it? If you were to add just enought weight to the front to tip the center of balance forward of the center of drag, (and with fins for stabilization,) might it not work better?

[kingspaz]

Guerilla, try adding 1% Fe₂O₃ (red iron oxide) to the fuel. this will dramatically increase burn rate and will give a superior fuel.

[mr.evil]

i guess MnO2 or other dioxides will work too?

[vulture]

Oxides from the transition group of the 4th periode of the Periodic table are mostly suited for this. K₂Cr₂O₇ seems to work as a catalyst too. Although I'm not sure about ZnO.

In chlorate composition MnO₂ has the greatest effect.

[kingspaz]

ZnO will probably not work too well. its properties are not really characteristic of transition elements due to the full 3d subshell.

[inferno]

My latest rocket design is taken from James Yawn's site, the micro-rocket. Basically, you roll Al foil around a little primed stick of caramel candy with a fuse sticking out, wrap it nice and tight, tape it to a bamboo skewer and launch it just from a straw.

Most have been failures because I used too much fuel, but some have launched :) .

[Guerilla]

Yep.. it´s amazing how much the presence of iron oxide increases the burn rate, I also just got my sulfur so maybe I´ll add it too to the fuel..

Nika, yes I didn´t use any stabilization method in those torps.. adding weight to the front might certainly help :) . Too bad it´s getting damn cold here and the lakes are starting to freeze..

Finely milled KNO3/sugar burns almost like bp, I´ve even made some firecrackers with it.. I need to build a new mill, the current is too small and slowly rolling. Does any of you use windscreen cleaner motor in ball mill? I´ve heard it would be perfect for this purpose..

[Agent Blak]

When adding sulfur to rocket fuel be careful. I have seen sulfur cause salag the will block the nozzle. Just a caution

[Eliteforum]

Speaking of milling, does anyone know if a food blender/grinder motor would be any good for a mill?

The reason I doubt it to be any use as it runs hot after about 5 mins on constantly, and am worried about the motor burning out.

I'll take it out of the blender (the motor) tomorrow with photo's.

[Marvin]

Youve hit the nail on the head Elite, they arnt designed to be run for any length of time.

I dont like sugar. Its messy, the mixtures dont dry well after being wet, if you try drying on the radiator it melts and still doesnt dry......

Add to all this that sugar is essentially carbon and water, and I really dont see why so many people use it.

Importantly, if you add a burn rate catalyst to a fuel it just burns faster, thats all. Its not in any shape or form, a 'superior' fuel, which only depends on the bulk chemistry. A rocket well designed for a slow fuel will perform exactly the same as a rocket designed for the same fuel better ground, or with catalysts.

There are so many reasons rockets dont work well underwater I'm not even sure where to start. So I wont. Someone had to try it though! I'll just say that underwater you need a much stronger force for a longer period of time, and outside water you need an impulse, equivalent to much weaker force for a very short period of time - which owing to the physics of each situation attains the same energy going into the vehicle. Rockets only provide impulse, if you arnt in a position to absorb the energy provided, its gone regardless, unlike a propellor.

[Guerilla]

A superior or a fast burning, I´m sure we all got the idea so let´s not split hairs <img border="0" title="" alt="[Wink]" src="wink.gif" />

And like I said, I did those "underwater rockets" just for fun.. It´s good to do things also in practise, not just forget them by saying "it wont work"..

After all, why should one criticize so much other´s experiments..? Why should care, if the other knocks his head against a wall <img border="0" title="" alt="[Wink]" src="wink.gif" /> .. Though constructive criticism is always welcome..

[Arkangel]

Well I'm fresh back from a weekend at "home", where I've been doing some serious trials on my new rockets. These are the first ones I've taken any time over, and I've been well pleased. Salvaged tubes from a cake (id 3/4"), along with the stinger tooling from skylighter. Every time I use it I grin at how easy the nozzles are.

My tubes are 6" long (apparently that's average;)), and the stinger core only about 2", so initially they launched ok, but when the the cored part had burnt away, they pretty much lost thrust, but burnt on for 30 seconds or so. Unfortunately this meant that they took off, but then flopped into the garden 3 from ours, or on the cricket pavilion, fizzing away like dinky incendiary bombs....... :)

Anyway, the later ones I tried with a core 90% of the length, and they worked a treat (The nozzle and 1st part of the core was made with the stinger mandrel, the rest was carefully drilled out through the nozzle).

For fuel I used 70% Sodium Chlorate (via the coffee grinder), and 30% icing sugar. I initially got a small amount of slag in each nozzle, but I never recovered the rockets with full length cores, so don't know if it happened with them. I think my Chlorate was damp (surprise surprise), so I'm going to make sure the next lot is bone dry. Marv, I don't know about being happy to have a rocket launch with a sugar comp, but I have no doubt at all that these will carry a good payload.

To fire them, I taped a length of safety fuse into the end of a short length of quickmatch. This I folded in half (lenghtways) and inserted it into the nozzle as far as I could without forcing it. They lit and launched noticeably faster with the quickmatch than just straight safety fuse, although a slower launch is sometimes fun, as it's more like a bigger rocket.

Guerilla, instead of trying to make them travel underwater. with a flat, calm place like you have, I reckon you'd have a lot more fun with a surface skimming "mini exocet". Another project that would make me smile would be to make some mini polaris missiles. You could make an underwater battery of them, sealed into little silo's like a sub. Wait until a duck, or canoeist paddles past, before you launch and let them think WW3 is on the way.

A major problem with sugar comps, as you said Marvin, is water, especially with something like Sodium Chlorate. That said, I'm quite thorough with it. 1st I keep everything somewhere very dry. Secondly, I seal each thing into a tub, a sheet of tissue on top of the chemical, and then a couple of freshly dried bags of silica gel on top of the paper. How do the rest of you deal with hygroscopicity?

<small>[ November 11, 2002, 03:29 PM: Message edited by: Arkangel ]</small>

[Harry]

OK, maybe a fellow has to live among the fisherfolk to see the obvious potential in those homemade torpedoes...

Just add a FP charge. Launch straight down in deep area of lake. Pick up stunned fish, fry. Or submit largest fish to contest judges to win cash prize.

Harry

[Guerilla]

hehe.. thanks for the tip Arkangel, gotta try that next summer :cool: .. the stunning torpedos with a HE would also be worth of trying, although have to be sure that the torpedo really goes off in the deep in water, not under a boat :D

but seriously, I´m gonna do more experiments with those bates grains..

p.s Ark, did you ram your NaClO3/Sugar fuel into the tubes, is it really that safe to ram dry chlorate mix, or was it dampen for that reason?

[Arkangel]

For fishing, it's far simpler just to tie a decent size salute to a rock, cut the right length of fuse and then lower it into the water. Save your rockets for something more appropriate! <img border="0" title="" alt="[Wink]" src="wink.gif" />

Edit: Guerilla, I rammed my mix, using Aluminium tools and a hefty rubber mallet. I'm just getting the feel of ramming it enough for a consistent nozzle and grain, without bursting the tube. The comp was mainly damp because I used some chlorate that I'd milled a while ago and not sealed properly. I re-screened it and then had it drying on a heater for a while. Even so, the mixed fuel was making stuff sticky.

I intend to make a shitload of rockets as soon as I can get the tubes for it, and when I do, I'll be making a mini hydraulic press, plus sleeves to prevent the tubes from bursting when I do it. The press will also incorporate a blast screen just in case.

<small>[ November 11, 2002, 04:15 PM: Message edited by: Arkangel ]</small>

[Eliteforum]

I'm wanting to make a rather large rocket, and would like some advice.

I'm planning to use a Pringles tube for the engine, and want to use Sodium Chlorate/Sugar(Charcoal a good idea?) for the fuel.

So, a few questions that I have. Would I really need a nose cone? As I'm planning on launching it from a sort of stick flight.

<img src="http://www.boomspeed.com/eliteforum/r1.gif" alt=" - " />

And would a solid core, or part core rocket be best?

Would the sheer weight of all the fuel be too much for it to able to take off?

[Anthony]

Of course it will take off, if you have made the motor appropriately.

Experiement with core length, there's too many variables for us to be able to simply tell you. Depending on the quality of your propellant you might not need a core.

The pringles can will never hold the pressure.

No, you don't *need* a nose cone, like bicyclers don't *need* those stupid pointy helmets.

Arkangel, are you using a sleeve when ramming your motors or are you getting away without one? The combination of my homemade tubes and my heavy handedness (NO voids in my grains :) ) meant my tubes used to split, or more commonly, bend. I found split sleeves to be a bit of pain in small sizes, but a short length of copper pipe did the trick. The internal wall is nice and smooth and with a bit of vaseline on the motor casing, I never got one stuck.

Depending on how the cardboard tubes go with you, copper pipe might be useful. It's relatively light and doesn't need a sleeve. I never had one explode and only managed to bend one once on full pressure in a 2ton press :)

[Marvin]

Guerilla, my intention was not to piss on your bonfire <img border="0" title="" alt="[Wink]" src="wink.gif" />
The idea of running rocket underwater is too cool not to be tried, but every time I think of it, I just see the reasons it cant work. Eventually this will be a problem, but for the time being the narrow road best guides me.

I do however consider the difference between a fast fuel and a good fuel to be very important indeed. Too important not to be pointed out.

Arkangel, for what its worth, I tried sugar/sodium chlorate mixtures for everything from rockets to stars, and the compositions simply would not dry. Even with forced hot air the mixtures were only superficially dry for a fraction of a milimeter. At that point I gave up on sugar totally and went on to try making my own charcol, with much improvements.

None of my chlorate mixtures contained sulphur or sulphides and were not prone to degredation, self ignition or detonation. However, chlorates are more toxic, and generally have a much longer list of donts, than nitrates or perchlorates.

More recently Ive been able to get KNO3 in quantitity, and Ive given up on chlorates alltogether. Never had 1 accident with sodium chlorate mixtures but damn am I now heartily sick of yellow.

[Arkangel]

Marvin, I do agree, and I'll be moving away from sugar when I have a the time to mill some charcoal, which will be soon. I have a Kg of airfloat, but want to save that for lift charges. I also have a Kg of Sorbitol (both from Skylighter), which I'll probably use next. Any idea how hygroscopic it is compared to sucrose?

Anthony, I haven't used a sleeve for ramming up to now, was going to save that for when I build a hydraulic press. However, I might just make one now, as like you, I want NO voids and I've wasted too many tubes. Thanks for the tip about vaseline. I don't normally keep the stuff :p but since I fancy making some smokes and cheddite I'll nip to Boots and get some.

Btw, I saw one commercial company selling rocket motors, and they sell 3 types of fuel. One has white smoke, and medium power, one has minimal smoke and high power, but the 3rd had lower power, with loads of black smoke. The latter would look most impressive with my multiple launcher, any idea how I'd create that effect - vaseline/napthalene in the fuel?

Finally, for ramming I use all aluminium tools, and a rubber mallet, I'm going to look out for sleeves to stop my tubes splitting. I also have thick welders leather gauntlets, leather sleeves, leather apron over the top of a kevlar vest, plus welding face mask with the black glass removed. (I got my girlfriend making rockets last weekend, she was well into it, especially when we got to fire them :D )

Edit: Eliteforum, as Anthony says, a pringles tube would be way too weak. The larger it is, the harder it is to make a rocket out of cardboard, the walls have to get thicker & thicker & thicker. You're going to have to look elsewehere for materials. Most of the larger model rockets are made from Aluminium casings, and you might be able to do something like that cheaply.

Another alternative would be to use your pringles tube, but carefully laminate 2 or 3 wrappings of fibreglass around it. Weight for weight that stuff is supposedly stronger than steel, and you could make yourself a stong, light body quite easily. If you make something that size, I'd be tempted to ram the grain very carefully and slowly. Then, use a carpentry auger to drill a core by hand. A lot of military rocket cores are not just a simple round hole, but are cast with star shaped profiles, or even have multiple long grains within the motor body for higher acceleration. You'd be looking at a short, very intense burn.......and stand well back! :D (I also wouldn't use a nozzle.)

Btw, I grew up around fibreglass, so if you need any advice on how to...let me know

<small>[ November 12, 2002, 07:07 AM: Message edited by: Arkangel ]</small>

[vulture]

What is your problem with chlorate? Just convert it to potassiumchlorate with some potassium salt, use your imagination.
Chlorates are also much stronger oxidizers than nitrates.
If you're having problems with your mix getting wet, add some dextrin to it, this will bind the mix with the water it absorbs from the air. After the dextrin has done it's work, it won't absorb water anymore.

I have also noticed that mixing strontium or bariumcarbonate through the fuel does not only create a beautifully colored flame, but also reduces hygroscopicity significantly. It also makes your fuel safer to store, because it will neutralise any acid traces.

[Guerilla]

I'll have to build my own chlorate cell soon, so I can test those chlorate rockets. If rc hadn´t done his job, I would have plenty of chems bought from the local pyro suplier (KClO3 3.3€/kg, KClO4 3.7€/kg, fine Al/Mg 10€/kg and so on.. damned! :mad: ).

Anyway's, the tail colored rockets sounds good and pure carbonates are ok with chlorates, but if those carbonates are obtained from the ceramics store, they probably contain some sulphates too, which arnt good to be mixed together :rolleyes:

[vulture]

What is the problem with sulphates? The sulphates of barium and strontium are also insoluble in water and are not acidic, so I don't see your point here.

[kingspaz]

i think he thinks there could be residual H₂SO₄ in the suphate. i find this very unlikely though.

[Marvin]

vulture, to convert the bulk of sodium chlorate into potassium chlorate is easy, but to reduce the sodium content to a point it can be used for other colours requires a lot of work. It took me 5 or 6 recrystalisations to get it to the level I could see the potassium colour through the sodium yellow, and it still wouldnt be suitable for blue.

[EP]

something I just found on underwater rockets:

<a href="http://www.geocities.com/warthaug/rocket/" target="_blank">http://www.geocities.com/warthaug/rocket/</a>

[Guerilla]

I meant the sulphates may contain some residual acid, but the amount might be so small that it doesn´t effect at all.. shit, I should not talk about the things that I haven't yet tried by myself..

btw, have any of you ever added a coarse Al or Fe to the fuel to get a sparky tail? How much one should add it?

[vulture]

If I'm correct, the sulphates from the ceramics supplier are not made with acids, this process would be too expensive, as it would use sulfuric acid. I think the bariumsulphate and strontiumsulphate from your ceramics supplier are industrial waste products, much like calciumsulphate, which have been made by substition by other salts.

EDIT: Something blatently obvious just occured to me: the sulphates which are present in the carbonates CAN NOT contain sulfuric acid traces because these would be immediatly neutralized by the carbonate! :rolleyes:
Let me ask you another question: Do you worry so much about the acid traces (which are far higher in conc) in the peroxide and the acetone you make your AP from?

Marvin, the potassium flame color is very weak compared to the sodium, but if you use other coloring salts like barium the sodium content will be barely visible.

<small>[ November 13, 2002, 12:29 PM: Message edited by: vulture ]</small>

[Marvin]

Sulphuric acid is the most mass produced chemical of all time and is extremely cheep in bulk. I would expect most of the sulphates we use to be ultimatly derived from the industrial acid. I suspect sulphate is one of the methods it is extracted from its ore using and allthough I cant think of any process offhand that would use toxic and relativly expensive barium compounds instead of calcium for example, and then just get rid of the sulphate, but you may be right. The sulphate is fairly easy to convert into the carbonate.

Potassium is weak, which is exactly why I was aiming for it. Sodium disrupts colours very easily, even greens and reds would need several recrystalisations to avoid washing out. If someone is desperate to try colours, it can be made to work, but its a huge amount of effort for a very small amount of oxidiser.

I was wrong about candy, its not half as bad as I thought, sugar is essentially only carbon and water, but for some reason this makes interesting things happen in the exhaust, with the production of unburned hydrogen in the for example. The result is that candy has a specific impulse, which although not impressive, is about 50% higher than blackpowder. I am going to find out more about this, this is very curios.

[inferno]

I have "discovered" a new propellant - Roll some BP into slightly molten caramel candy....Burns VERY fast for KNO3/sucrose, i wrapped a blob of it in 3 layers of newspaper, it shot off in my backyard, just lit on the ground...There was about 20g in it too. I've had little 1" long 5mm sticks shoot off a bit with normal candy, but never such large chunks :)

I have a bentonite nozzle drying in a piece of 15mm uPVC (pressure pipe) at the moment, the inside end of the pipe was roughened up for more nozzle grip. . I will whip up some candy soon, roll it with some BP, and quickly press into the rocket. This part is a problem, as the candy seemed to cool very quickly once i flattened it out to dust it in BP, but then, that was 2AM this morning and it was pretty cold out.

If i can get it pressed into the tube well, i will drill a core up with a hand drill (No electric drill :S) to aid in stabilisation. It will be stick stabilised, as my attempts in the past at making fins have not worked well. The stick is a little small, about 5-6mm by 2ft, it was taken from a kite.

The rocket will either blow out the nozzle, explode, not take off, a mixture of all three, or take off succesfully up into the sky, or take off and kill someone at the park I'll be doing it at :) .

[static_firefly]

Ok i have written up a file on the production of my rockets. As of yet i havent written anything or taken pictures of it in flight but will do that soon, iv just been busy playing with AP salutes. The file is located here
<a href="http://www.pyrosupreme.tk" target="_blank">http://www.pyrosupreme.tk</a>
look under rocketry. I even took some photos of during productions to help with my incohereant rambeling "instructions". I will fix that

[warweed12]

i am curious to when yo make and produce your engines if you can add small amounts os magnessium (sp?) to your mix to produce a blue flame from the back of your rocket?

also as to ignition in a core burning rocket would a christmas light bulb with the top removed with a small amount of KNO3 and Magnessium flash or if not that some smokeless black powder that has had the wires on the base of the bulb extended and a cover or jacket on top of the wires to prevent it from shorting out inserted to the top of your core and ignited electronically would this work realably in the core burning engine ?

also what is a safe way to judge the core size in the maufacture of a rocket and what should the nozzles clay length be inside the main engine tube ?

----------------------------------------
Sorry in advance i have yet to learn my grammer so i hope you can bare with me and my post (i moved alot as a child and the coarse and levels changed alot it made it hard to learn)

[Anthony]

Mg burns with a brilliant white flame, I have no idea where any blue colour would come from in a KNO3 + Mg + sucrose comp.

Plugs/nozzles should be at least as long as the I.D of the tube.

[vulture]

Static_firefly, I looked at your site where you say that KNO₃ is inert and that it just melts when heated. I find this a very dangerous description.
Potassium nitrate will decompose into NO_x and oxygen when heated enough.

[warweed12]

humm intresting when i burn my magnessium in fountain mixes or other slower burning mixes or ignite a small batch of the flash it always explodes and produces blue as for the nozzle what would be the correct Core size ?

[Anthony]

Introductory to Practical Pyrotechnics suggests that nozzles for drivers be 1/3rd of the tube ID.

[warweed12]

Ok thanks for the tip

do you think fertilizer grade potassium nitrate would be good enough to use in a engine if it is milled ? there are a few impuritys but do you think it would effect the overal performance of the burn ?

[0EZ0]

Fertilizer grade Potassium Nitrate should be fine. If you find it to have considerable impurities (packaged as 90% or less KNO3), then just purify it.

[static_firefly]

hmm...how hot does it need to decompose into that? I geuss i should stop melting it. Any way i will change it soon. thank you

[Anthony]

400*C

[Rene]

Hi there,

To get a good break, for small payloads on rockets you need a fast burst to ignite as manny stars you have,(flame will reach faster ALL the stars and afcause not a header witch will burst direct. If you use a to slow burst the stars mosly burn up inside of the header or this header case bursts to fast, mosly a soft flash will do the job,If you use a TO fast burst, it could be possible that the stars will breakinside the header, and you will see only a few of them.
The most german rockets glue a cardboard disk inside to take care that the rocket dont blow the stars out of the top. this is also to keep care that is the noscone pops of the stars wound fall out and kep them on place.

i mosly use 1/2" rocket engine's with normal bp 75-15-10 a 12 mm bentonite nozzle 3 mm dia core, and the lenght of the core of 30 mm from bottem clay nozzle into the BP.
and ram the fuel in verry small layers and en with a 10 mm layer of bentonite with a 3mm hole for transfering the flame into the header.
I ude dry bentonite and also dry BP also dont use any dextrine.
they mosly are ready to use, most wet clay will shrink inside the tube
and also wet bp will shrink, witch give you a nozlle blow or CATO,
what could be done is to use a slight wett tube (will shrink after ramming) but then you need to use a sleeve to keep the tube in one peace.

mosly larger engine's need a slower fuel because they have a mutch bigger core so the trust willget to high

Regards Rene.

[Fukineh]

I’m considering constructing a small liquid fueled rocket engine and I'm wondering if anyone here has done so and what fuels they have used. I have heard of just regular gasoline and compressed air, but since I'm working small I may try hydrogen and pure oxygen- assuming that this reaction would not be overly violent and unpredictable.

<small>[ December 09, 2002, 10:00 PM: Message edited by: Fukineh ]</small>

[Marvin]

You want to make a *liquid* fueled rocket out of hydrogen and oxygen yourself?

Aside from requiring cryogenic equipment, hydrogen and oxygen is one of the most explosive combinations of gases you can have. In a rocket making this combination burn rather than explode is a tricky thing, and if the engine ever goes out you fill large areas with explosive gas mix very fast. Hydrogen/air has very wide combustion thresholds, which is one of the things that make it so dangerous to work with.

'tiny' for a duel liquid fueled rocket would probably be a meter long, so I'm not sure what you mean by 'small', any smaller and its just not practical to build the pipework/pumps/valves/combustion system/exterior and actually have it leave the ground. Container requirements go up with the square of one dimention, volume stored goes up with dimention cubed, which essentially makes liquid fueled rockets big to keep the mass of fuel much larger than the mass of the rest of the rocket.

What you build, if ever you can get hold of the chemicals, will probably depend on what you can get. High concentration hydrogen peroxide will work well as a monopropellent, or with ethanol for duel. If you can get someone like BOC to sell you liquid oxygen, or liquid nitrogen, from which you can make liquid oxygen yourself, then LOX/Kerosene is another good one for home build.

I doubt Id be able to build one myself without dedicating about 5 years of my life to it, and it that time its possible to build some very impressive solid fueled rockets. Some people would argue simply getting a liquid fueled rocket launched is worth the effort and if you agree, good luck.

Ive never heard of any rocket that uses compressed air as an oxidiser, Id think whoever thought of it has been dreaming of water rockets. Even compressed oxygen is a lousey oxidiser if you include the weight of the reinforced container.

[Mr Cool]

Search for "microhybrid" motors (I think). They use things like rolled up paper with a hole down the centre for the fuel, and the oxidiser is one of those 12g N2O cylinders. They'd certainly be easier to make than a LF rocket, but more of a challenge than SF.

[static_firefly]

The newest way iv started using for lighting rockets is have a fuse that at the end shoots a heap of sparks into the core. Basicly i dont need to prime them

[Arkangel]

Often there's a time when a rocket doesn't fire all the way up the core initially, and that may be good, for example if you want a slow, dramatic lift off. But generally, it's going to create unreliable results.

There's a phenomenon known as "chuffing", caused when the full length of the core doesn't light immediately. Your motor sounds like a steam train setting off, and it can cause you all sorts of headaches. ( a google search for "chuffing rocket" will produce some interesting results.

If you can light right to the top every time, (or better still FROM the top) it's better all over.

[vulture]

This may seem like a stupid question, but how does one succesfully slow down whistle mix? A static engine test with pressed whistle mix in an open tube created a devastating bang. :confused:
Mind you, I was planning to make them with a core...

[nbk2000]

In artillery ammunition, the primers extend a good length into the powder charge.

This is done to ensure that the propellant charge is sufficiently ignited to completely burn before the projectile leaves the barrel. Otherwise, with only end ignition, some of the propellant will be unburnt and thrown out the barrel, being wasted.

If you can coat the interior of the rockets core with a fast first fire mix, and used an ignitor that would throw the flame the entire length of the core, then you could ensure full grain ignition, without the "chuffing". Some research into the Space Shuttles booster rocket design might give you some ideas.

Maybe a spigot arrangment would be better. You set the rocket over a hollow tube spike which extends the entire length of the rockets core. A fast burning charge of something hot (like sparkler powder) is in the end near the top of the core.

When that is ignited, it acts like a gun, launching the rocket off of the spike. As it does so, the flaming sparklet mix contacts the entire length of the rockets propellant core, ensuring an almost instantaneous, and complete, ignition of the core. :)

[Anthony]

I think you can slow down whistle mix by adding a small percentage of vaseline.

[CyclonitePyro]

Thats what I use in my whistle mix, I'm away from home right now but when I get back I'll post percentages. Just melt the vasaline, add laquer thinner, and pour and mix with fuel.

[ThE mAdD rEaPeR]

i made a kno3 sugar sulfur rocket as followed by instructions fomr this website http://www.alphalink.com.au/~brucej/nickle.htm
i used the same casing, the same ratios, except i used a clay nozel with a 2ml hole.
i atached a 1 foot guide stick and placed stick through a straw for stability.
wen the fuse was lit everything looked fine. the rocket lifted off the ground about 1 foot, then curved about 130 degrees into the ground and stayed burnig for the duration of the fuel. i think it might hav been something to do with the guide stick, but i am not too sure. if anyone could help me it would b greatly a[reciated.

[xyz]

That KNO3/Sugar/Sulfur comp is not a very good one.

Try using 66.7% finely powdered KNO3 (use a coffee grinder) and 33.3% Icing sugar (check the ingredients to make sure that it is pure icing sugar and doesn't contain cornflour). That should give much better results.

[ThE mAdD rEaPeR]

ok, ill try that, i was using granulated kno3, so hopefully it will work this time.
i dont have a cofee grinder, but a mortar and pestle would work wouldnt it?

-----------------------------------------

Just because the filesize limit is set to 512000 bytes you don't need to take full advantage of our free image hosting service and attach images in a size of 1600 x 1200. Apart from messing up the whole thread it takes ages to load and doesn't contain any details one wouldn't see if it had been cropped and resized to 100 x 250 (and yes, I bothered to try this!).

You may attach the file again if you reduce its size, but please don't make me regret not banning you.

Rhadon

[pornopete]

Reaper I was having the same trouble with my bp rockets, Use a longer stick and a larger nozzle seemed to work for me, but if your not getting blow out of your nozzle a much bigger stick should do the trick.

[blindreeper]

i used a clay nozel with a 2ml hole.
I am getting so pissed about this. Sorry for being off topic, but ml is a measurement of volume not distance! Its mm for millimeter not ml for millilitre. I know in Australia we say mil in releation to distance but it should stop here!

Back to propellents, I think BP is the best one out there for amatures. Its very cheap and easy to produce.

[kvitekrist]

Hello again.

since the post is up, I thought I might post our latest development in KNO3/sorbitol rocketry.


Me and my friends have finaly gotten a propper rocket of the ground, the specs:

overal lenght: 1,5m PVC tubing Ø80mm
motor: 500g image (http://home.no/kvitekrist/stasj/rk1.jpg)
recovery system: parachute (failure)
fins: 4 fins, made of wood.

video: http://home.no/kvitekrist/stasj/3,1%20rakett.wmv
picture of the whole thing: http://home.no/kvitekrist/stasj/rcb/r31.jpg
impact picture: http://home.no/kvitekrist/stasj/rcb/impact.JPG

[Bert]

That's a nice looking rocket. The motor looks to be metal cased? What was the mehod used to actuate your recovery system, pyrotechnic delay or other? Have you analyzed the cause of the failure to deploy? More details, please-

The after impact picture is a classic "lawn dart" recovery... I'm guessing the ground was frozen or you'd have seen only the fins!

[kvitekrist]

The motor body is made of aluminium, and the nozzle is made of stainless steel.

And the parachute system Had a "tiltswitch" and a pyrocharge to deploy. The system actualy worked but i guess the BP dident ignite, since the nicromewire had melted trough som plastic.

the impact site had about 30cm of dirt and then rubble and stones, that's why it dident go any deeper..

rocket after (http://home.no/kvitekrist/stasj/rcb/knuust.JPG)

[spydamonkee]

Incase some have not seen this site yet...

http://www.inverseengineering.com/

He has a really good step by step guide (http://www.inverseengineering.com/Pages/2002/Incendio%20project/Incendio%20engine%20overview%20and%20construction. html) to making a 3.65lb Rocket

[AsylumSeaker]

Has anyone had experience using peices of bamboo as casing for a rocket engine? I have stacks of bamboo lying around here. Wall thicknesses range from 5 to 25 mms.

[pornopete]

Bamboo works really well, Its actually quite light. I use car bog to form a nozzle and it seems to stick to the wood nicely. Ive only tried in the following dimensions: 1.5mm by 4mm i drill a 2mm nozzle and core it half way up, these go about 60m high but you need quite a long stick to keep them straight.

[NoltaiR]

Wow it has been a long time since I have been to this forum (well before yesterday). I read over the first page of this rocket thread and this page. So if I accidently repeat something from pages 2 or 3 then just forget it.

Anyways on the first page I read that someone was wondering about Zn/S rockets. Well from the little bit of research I have done, this propellant isn't supposed to be all that impressive and when you do find information on it, it is usually on the same page as your common candy propellant. But in any case now that I have some free time during the holidays (over 3 weeks) I am going to try my hand again at rocketry. I had tried it before a few years back but had many disappointments that led to many wasted dollars!

I ordered 10lbs of powdered Zn and 7lbs of fine sulfur so I will have some extras if I mess a few hundred times. But even if this propellant isn't meant to send much more than its own engine airborne, I have seen some burn tests of it and this stuff makes for quite a show in the dark.

Anyone know what color the sparks would be if I also through in some larger Zn flakes???

The next thing I would like to comment on is the question on bamboo. Well from what I have read, bamboo was the first thing EVER used to make rockets and firecrackers by the Chinese way back in the day.. something like 300AD. So if it worked for those smart little guys then it should work for anyone.

Nextly are some questions that anyone may answer to save me the trouble of more searching the net. And I guess I will just list these questions..

1. I have heard that water putty makes for nice endcaps and nozzles when drilled... anyone tried it or have suggestions on other things?

2. Is epoxy pretty much the universal binder for propellants or are there others that I should consider?

3. How large should the core be made (in both length and diameter) in relation to the fuel stick itself?

Ok those are just some things that I have been searching for but not come across.. any comments are appreciated.

And lastly I stumbled upon a page about making candy rockets but the difference between his (the author's) and your run-of-the-mill 5 cent rocket is that his uses Karo syrup for the binder. He even claims that he has even made a rocket that went 3000 feet high with only 75g of the stuff. Well this may just sound like bullshit but if you read his page it is obvious he has made these things MANY MANY times.

http://www.jamesyawn.com/rcandy/candy.htm

edit: also does anyone know the percentages of materials in H3? I was doing a search on it here in theforum but it seems that you can't put a search word in with less than 3 letters :(

edit: edit: damn i just bought some KClO4.. 20lbs of it.. and I think that H3 just uses KClO3.. oh well anyone think this will make much of a difference?

Anyways I would like to add that I was just doing some more searching and I found a site with a lot of flash compositions but I am going to have to point out that they do suggest using KClO4, charcoal, sulfur in one of their mixtures and in my experience mixing sulfur with any chlorate or perchlorate is not smart!

[pornopete]

For noltair:
Question 1: I use car bog for my caps, it drys in about 10mins and is reasonably heat resistant.
Question 3: Your nozzle size will depend on the size of the engine, core size will depend on size of your nozzle. For example im currently experimenting with 4cm by 1.5cm rockets, i use a 2mm nozzle and a core about 1.5cm up. I find that if I core all the way there is too much pressure and my cap will blow out. It took me awhile to suss this all out but I rekon hands on experiance is the best way to get the dimensions right.
Have fun!:)

[thesentenial]

vulture: Strontium Nitrate is found in commercial road flares, it produces a red flame (i bet you already knew that, but for others reading)

[NoltaiR]

I know this is a little off topic but I had someone inquire via email. What are the laws pertaining to shipping oxidizers outside of the United States? How hard would it be to get it outside of the U.S.?

[Bert]

US pyro suppliers won't ship oxidizers outside the US. You would need an export license, which would be quite expensive. They also won't ship most pyro grades of metal powders.

[vulture]

vulture: Strontium Nitrate is found in commercial road flares, it produces a red flame (i bet you already knew that, but for others reading)


Eh? Where did I enquire about strontiumnitrate? I make it myself, so no use asking...

[NoltaiR]

I was searching for something to use as a nozzle maker and bought some Bondex brand plaster filler. Sounded like it might do the trick but I won't know until this weekend. Anyone have an idea how it might work? I have also heard of people using kitty litter... well it makes sense that you can tamp one end into the tube.. but once the fuel is in, how do you make the other end?

[The ALL-MIGHTY]

NoltaiR:

Sorry if someone said this already but I didn't read all the posts for this topic, 4 pages...., anyway for nozzle mix why don't you just use wood putty? I tried this and it seems to work just fine, dries very hard. Then after you add the propellant you can use epoxy to seal the top or just more wood putty. I got all this from krimzonpyro.com, or rather a link from. The exact link I think is http://www.alphalink.com.au/~brucej/nickle.htm , its mainly on sugar rockets, but it does suggest wood putty and epoxy. Hope this helps, even remotely.

[spydamonkee]

So far i have only had semi-success with rocket's, mainly due to not having proper equipment like scales, nozzle's, iron oxide & tooling... wish i had more $ to buy these thing's :(

The best luck i have had so far is a nozzle-less 1.5cm * 5cm "engine on a stick" take off about 2 seconds after ignition going all of one foot into the air then 3 or four feet across the ground.

As for kitty litter i was unable to find any made from bentonite, however they had some made from zeolite & after a few search's it appear's to be similer if not the same stuff so when i can afford it i shall have nozzle's... and working rocket's hopefully

Mix I use is By volume 50/50 KNO3/Sugar with a marble size scoop of honey seeming i dont have corn syrup (golden syrup or maple syrup?) It seem's to burn ok, A 4cm * 6cm engine I static tested looked impressive with damn near a footlong flame screaming out of the core :D

[Crazy Swede]

Noltair, you asked how the end plug is made for rockets.

Well, the easiest way is to ram clay, bentonite or something else that compacts readily, very hard on top of your rocket fuel. The end plug should be rammed so well that the tube actually expands a little. By doing this the end plug will be secured in a better way, compared to a weaker compacted plug or just adding glue on top of a rammed paper plug!

[mr.pyro]

The strongest way to make engplugs, although they might take longer, is to fill with expoxy, then put wood putty when that is dry, take a pipe end cap a size smaller and invert it into the pipe. and secrure with screws.
Like this
||_||
| |

[frogfot]

I'm currently testing another way of endplug (nozzle) attaching. I reduce slightly the pipes diameter in one end, wrap this end in cotton string to keep it a bit cone-shaped (convergent). Then, nozzle/plug is filled in place (putty or in my case gypsum).

Plug shouldn't go anywhere as long as string holds.

I've tested this several times a year ago with small candy rockets with success. Wanna start making bigger (100g) rockets this time, to make sure that this wasn't only luck that my nozzles held.

[NoltaiR]

Well my shipment of Zn arrived this weekend in a very well wrapped packaging. (The 10 lbs of zinc was in 6 large envelopes that were placed within each other, then wrapped in many layers of plastic, then set in an even larger envelope).

Anyways although my shipment of pure S hasn't arrived yet, I stll have some 90% pure S made for plant dusting. I very roughly mixed a 1 part to 1 part by volume of each (allowing a little more sulfur due to %10 of it being inert ingredients) and then ignited about 1 cup of this stuff at night by means of a match and a little KNO3/sugar mix. Within no time the Zn/S caught fire and made quite a beautiful yellow-green fire with thick clouds of white smoke (this burn test was done unconfined at night). I wasn't expecting anything extraordinary due to my lack of exact measurements of the materials and due to the impurity of the sulfur, but to tell the truth this is one of my most impressive burn tests I have ever done.

The light was quite bright and the heat energy the fire had was quite immense especially considering that it doesn't have a very fast burn rate... the 1 cup pile took at least 7-10 seconds to burn completely unconfined.

I should say that I am quite ready for my pure S to come in so I can start making some rocket shows with this stuff.

edit: I will start making use of my new digital camera and make pics of any further work

[frogfot]

I got a stupid question.. Should one be concerned about rocket falling down on someones head? This really bothers me, doesn't most pyro rockets use heavy putty endplugs?

[Bert]

frogfot-

They say the only stupid question is the one you don't ask- (Here abouts, it's also the one you didn't search on before asking!)

Yes, a rocket falling on your head is a danger. I love rockets, but in the US they are almost never part of a commercial public display for that reason, and also for two other reasons: 1) You really don't know where a rocket is going to go, unlike a shell where it's going in the direction the mortar's pointed pretty much no matter what - And 2) After the display, you might just have to go clean up all those rocket sticks.

In Europe, particularly Portugal and Spain, massive flights of rockets still feature in public displays. The audiences in these countries seem to take more responsibility for their own safety than those in the US- They still understand that they CHOSE to go to a fireworks display and to undertake some risk, whereas a US spectator will often sue you for the slightest damage or injury, then sue you for mental anguish on top!

A large rocket tube still attached to it's stick and returning ballistic will orient motor down to take a core sample out of someone's skull. I've seen them stuck 6" into the ground like a lawn dart, they could quite conceivably kill someone. It's best to head a rocket with a salute large enough to shred the motor tube and blow the stick clear, the separated pieces are not nearly so dangerous. In fact, the Portugese used to like to head theirs with dynamite- And who could blame them?

[flashpoint]

I'd blame them if it didn't go straight up and it came flying at me, laced with dynamite :-/ I find that my rocket motors, are compeletly gone after launch, the sticks I can find usually.

[Blackhawk]

Then they are eaither shit and CATOing at burnout or they are simply flying off the stick and they are still falling somewhere....

[blindreeper]

I have had several of my 4oz BP rockets land on my corrigated (sp?) iron roof and they leave some nasty dings! I use electrical tape to secure the rocket to a bamboo stick and they never seem to come apart. I have also had some come down within metres of the lauch site and they get smashed as they hit the ground. The end of the tube is all mashed and sliced up. I don't think small rockets could do much damage but when they start to get as big as dan williams...well thats a new animal :p

[frogfot]

So, it wouldn't be enough to develop a reliable rocket that can be directed...

Then, one should think about parachutes. Ha, time to learn how to sew! The triggering circuit wouldn't be that expencive.

Btw, is it worthy to by a heat resistent (1300*C for fireplace) cement for nozzles? I'm primarily interested in convergent-divergent nozzles that are reinforced with iron washers (from Nakkas page). Could usual cheap cement perform equal? With usual I specifically mean cement that is used in construction (large bags).

[SpiffyVision]

Im wondering if KNO3/S/Al would make a good propellent for rockets or maybe flares, it burns incredibly bright and would be great for shooting at night. Only problem is the gas output on it, if it gave off more, then it would work better. Any ideas? A freind of mine quite awhile ago (i cant really remember everything he said) said that using a binder and adjusting the ratios (5/3/2) a bit would help out, also maybe using different ingedients. Any thoughts?

[blindreeper]

I thought sulfur would make the gas out put massive. It doesn't burn terrible fast so I don't think iot would be at getting the rocket off the ground. The alumnium would also add weight to the rocket which would make liftoff harder again. To get white rockets I add 5-10% -325mesh spherical aluminium, they are very pretty at night. Other than that KNO3/S/Al probably won't be a rocket fuel too soon, but it does make a hell of a flare :P I have been making some salutes with KMnO4/S/Al and noticed that it burns about as fast as my BP, maybe a tad faster. This produces huge ammounts of smoke and gas so maybe with a large nozzle size it could be some sort of rocket propellent.

[SpiffyVision]

I guess the sulfur does give out a massive gas output but the question is, is it enough to take the rocket/flare to desirable height? I doubt the aluminum would cause big problems. If I were to experiment with this rocket though, should I put a clay nozzle on it or make it like a whistle rocket with no nozzle?

edit: I wonder how magnalium would work with this

[blindreeper]

I think a nozzle would be needed. You could try either but if you do, try the nozzleless rocket first because if that works then it will be easier for all of us to make them and not have to worry about a stupid nozzle :p

[Blackhawk]

Frogfot: I bought a small tub of fireproof cement for nozzles but I found it really annoying, once packed it takes areound a week of decent heat to dry properly (it will look dry on the outside but will still be wet on the inside) which is annoying because as it dries it shrinks and cracks, so I have to ram it with no nozzle and then drill it out later or there is no telling how wide the throat will end up being. This may be related to the specific brand, but I suggest you go for the special anchoring cement that expands as it dries as it will probably give a better seal. As I see it all concrete should be able to survive the heat of combustion for a few seconds but you only need fireproof cement where it will be in contact with heat for a very long time (ie fireplaces or barbacues)

I noticed that some bottle rockets a friend had (whistle mix kind) used no nozzles, I was thinking the same thing you are proposing above with a piece (10mm wide, 5cm long) of Al bar drilled out to 8mm inside with some KMnO4/Mg flash packed hard inside it and no nozzle, seeing as this stuff is quite a lot more violent than similar flash with Al and even S, although the S may increase the gas output.

[xyz]

The need for a nozzle depends on the burn rate of the propellant. Whistle rockets have no nozzle because the propellant burns so quickly.

The purpose of the nozzle is to increase the pressure inside the engine so that the propellant burns more quickly, if the propellant is already fast burning enough then there is no need for a nozzle.

[vulture]

Flash is no good for rockets, as it only creates short peak pressures by heating up surrounding air. A rather loud CATO will be the result.

[Bert]

Whee, an active thread. Happy New Years-

1. Drying type cements are a pain to use for nozzles. They nearly always shrink, Durham's water putty being a notable exception. Rammed clay (kitty litter or oil dry work fine for BP rockets) is quick, easy, cheap and easy on tooling. You will need better materials only for exotic, highly erosive fuels or where you need very high performance, as in composite high powered rockets.

2. I've seen nitrate flash used for rocket fuels. It is touchy and demanding. Get your BP rockets down and if you get bored, it's something to think about. Rockets made with Barium or Strontium nitrates and Magnesium for fuel can have colored tails- They are an advanced project, several articles on this have been published in the PGII Bulletin and elsewhere. Oddly, one of the problems these can have is too low thrust when made as nozzle less. But get a crack in the fuel grain or don't press them hard enough and they quickly become "bombs on a stick"

3.
The purpose of the nozzle is to increase the pressure inside the engine so that the propellant burns more quickly
Not the only reason- The nozzle and it's divergent section in particular are needed to make EFFICIENT use of the expanding gas, turning as much as possible of the available energy into thrust. Look at a space rocket- Why do you think it has that big bell?! Notice the upper stages designed to work in a vacuum have a longer, narrower bell? The parameters for max efficiency change as the pressure the gas is being discharged into changes. For a real mind bender, do a search on "aerospike engine". The whole universe is my nozzle...

The Chinese (who were recently dissed in another thread here) figured out roughly the best proportions and angles for BP nozzles at least 2,000 years ago by trial and error. Never underestimate a peasant, he may not have your education, but he wouldn't be here if his ancestors didn't have a clue. (NBK2000, they did too use BP for weapons. Oriental war rockets, bombs and wall breaching mines all pre-date European use in the 1300's. Give Europeans credit for flintlock and percussion priming though!)

Look at an Estes engine, the angles they use are designed for maximum efficiency with BP fuel at around 1 atmosphere of pressure. They're barely different from a good traditional Chinese or European BP rocket from the days before Newton.
if the propellant is already fast burning enough then there is no need for a nozzle.
True- Nozzle less engines are a good project, especially if you don't have access to a metal lathe and are capable of making fast BP. If anyone is really interested, I will provide an intro to the rocketry/black powder list where you will find a lot of useful information on rocket design, tooling and performance.
E-mail me if you want it bad enough, they don't like having their info posted.

[pornopete]

Next to your propellant I think Nozzles are the most important part in rocket making. I use car bog for my nozzles its ready to go in about 5-10mins its really hard and can take the heat. I havent tried flash rockets and havent had any luck with nozzleless ones.

[Blackhawk]

hah, forget rockets, my latest project will be a supersonic ramjet, can you say isp of over 1000 ;)
Yes the nozzle in a rocket is used to convert slow moving high pressure gas into fast moving low pressure gas as the thrust of the rocket is caused by the reaction of particles flying away so the only way you can increase the thrust is to make what is flying away heavier, or make it fly faster. Seeing as the only particles used in most rockets are very light gas particles the only way you can get better performance is to make the gas fly away faster, and the only way you can do this is to make your nozzle more efficient or to increase the pressure in your case, and most nozzle modifications will not gain you much thrust in such small rockets.

The flash rocket would have a nozzle if it would stand the pressure, but it wouldn't without being excessively heavy, but the ammount of gas moving out of the tube as fast as it does will create enough thrust (if not efficiently) I have made succesful rockets before simply by having BP push a plug out of a tube with a lot of force (sort of like making a gun fly by shooting a bullet into the ground) they work but are nothing special, just a lot of fun and re-usable.

[Bert]

hah, forget rockets, my latest project will be a supersonic ramjet, can you say isp of over 1000
Pray, Sir- Do tell us more. Your masterfull explanation of nozzle mechanics assures me that you are knowledgable to construct such a mechanism.

[T_Pyro]

Hmm... I smell the presence of undesired elemnts here. Blackhawk, exactly what is your idea of a "supersonic ramjet"?

Back on the trail of rocket nozzles:
I don't have access to any Durham's water putty, so I'm experimenting with a resin/hardener epoxy formulation used for sealing pipes here, called M-Seal. I'm not sure as to what its composition might be, but there's no change in its volume as it hardens. I'm currently in the process of testing it for resistance to high temperatures.

[Blackhawk]

A supersonic ramjet, well it will be around 15cm wide made of rolled and welded sheet steel, I am still deciding wether I will use a shock cone diffuser to bring the ram air down to subsonic speeds for combustion or wether I can have the inlet ducts like a simple subsonic ramjet and use the nose spike of the rocket body itself as the shock cone and rely on body difusion to slow the air down. The rocket itself will be boosted to very low mach 1 with an Al case 60mm (wide not long :P) KNO3 + sorbitol motor (aproximate K class with a graphite nozzle running at max 1000psi case pressure) made by a fellow rocketeer at the club I go to. The fuel will be kerosene pressurised with liquid nitrous oxide (only because the club already has fill/fire gear for it for our hybrids) which will be released when a pyrovalve has burnt through (a disc of popellent blocking the injectors untill it is ignited) However I am only basing this on what I have learnt from a lot of resources to do with subsonic ramjets, I have to reborrow a set of books from USYD that deal with 'Guided missile design' (they are old but physics hasn't changed scince the 50's) I won't begin construction for a while because the guy at the club who's machining equipment I will hopefully use will be in the US for work related matters for two months or something in January. But when I begin you will no doubt be keept up to date as you are so interested.
{EDIT} Oh in case you were hazy supersonic was specifically targeted at the airflow speed relative to the rocket body, not a supersonic combustion ramjet (SCRAMJET) as these would be VERY tricky and are still no completely understood, also it is only supersonic because I realised that the predicted thrust I would be acheiving from a much simpler subsonic ramjet would be insufficient to keep the rocket's velocity stable and seeing as the ramjet's thrust is proportional to it's speed the thrust would degrade rapidly once it began to do so.

Undeseriable elements ay, ask me any question about rocketry propolsion and if I can't answer it then I concede that I need to improve myself, but I haven't been flying rockets since I was 8 years old to have information wash through my ears. I don't claim to be all knowledgable but rocketry (and specfically aerospace engeneering) has been the focus of my life for the last several years and I plan to be good at it.

[Sparky]

**There was something here that made me look stupid, but I deleted it ;) **

Nozzless rockets are easy to at least get a fast little rocket out of. Small BP nozzless rockets (say around 1/2" ID) can use quite thin home made tubes, rather slow black powder, can be rammed instead of pressed, and the core can be drilled too instead of using tooling. If your black powder is slow just have a longer core. You don't even need clay for an endplug on the top as you can just ram more BP in there. Can't get much simpler than that. Honestly I can't think of an easier pyrotechnic device, other than a firecracker.

The trouble I see with trying flash rockets is that there is no way one should ram flash. So that means one would need need a press which most people don't have around.

Just a side note on clay, you can use kitty litter straight from the bag but it's too coarse to be pleasant. Ball milling it to a fine powder makes much nicer nozzles. Also, from what I've seen kitty litter clay isn't very good quality. Bentonite from a pottery store compacts better.

My friend has some 200 micron ammonium perchlorate, has anyone tried to make a relatively high performance rocket with ammonium perchlorate, using a paper tube? My thinking has been that normal paper tubes aren't really strong enough to take advantage of an ammonium perchlorate propellant, but maybe that's incorrect.

Another thing my friend was going to try is small (1/2" and 3/4" ID or so) melted dextrose/KNO3 rockets. The problem is pouring the propellant into such a small tube. I was thinking one could ram the propellant as powder then put it in a warm sand bath to melt it. This might leave air bubbles to cause CATO's though.

[Blackhawk]

uhh, read my post, you may have to refresh, but I certainly am not joking :P

Oh and BTW Ramjets do oparate subsonically but as they slow down they thrust produced rapidly decreases and their fuel usage rapidly increases. This just a thrust estimate based on diffuser area but as the ramjet gets larger the thrust produced increases exponentially (as it is a function of area rather than diameter) so while I am trying to build a small ramjet (as i don't want it to be too large to fit into the car) the only way I can increase the thrust to sustainable levels is to increase the speed although it would be far simpler to build a subsonic ramjet (just too large).

[Bert]

Blackhawk-

"A man's reach should exceed his grasp, else what's a heaven for?"

I've seen amateur rocket scientists make liquid fueled and hybrid engines. I've also seen them making flying pulse jets... A flying supersonic ramjet is an order of magnitude more difficult than those projects. You've clearly read about such things, but I'll believe you made one when I see the video/read about it in the papers. Among other things, suggesting you're going to launch it supersonic on a nitrate/sugar rocket (heavy payload, low ISP fuel) and specifying the chamber pressure of such a rocket at 1,000 psi (How 'bout 200-300?) both make me doubt. Also you're planning to pressurize your liquid fuel with an oxidizer? There's a reason for that nitrogen tank in rockets that work.

Reading your other posts, I'd say your heart is in this but your tech skills and PRACTICAL knowledge aren't up to such a project yet. No shame in that, mine aren't either. Is this a project that more um, senior members of your club are considering? Maybe a little bit of clarification (and moving the discussion of this subject to the water cooler) would be a good thing.

[Blackhawk]

No I came up with the idea of the project and have been discussing it with the more 'seniour members' of the club, which if reffering to age is an impractical and flawed method of judging seniority (which constantly plagues me). As for the chamber pressure, no I am not wrong, this is the chamber pressure of the candy rocket by the way (the ramjet psi would be in order of magnitudes lower) as 1000psi is generally the maximum design chamber pressure of most Al tube based amature and commercial model rocket motors I know of, and is quite within tollerances of the materials used I assure you. As for using nitrate sugar fuels yes it is a low isp fuel and while people at the club also fly much more advanced AP (perchlorate not peroxide ;D) based 'brews' they are also much more expensive. Really the limitation on the usages of these nitrate sugar motors are how big you could be bothered building them, but this motor is a flown and tested stock design, not another 'product of my imagination' as you see it and designed/built by much more 'seniour' members. Realy a ramjet is not that hard (subsonic anyway) and very much within the reach of ammatures including myself, and even though I have little practical experiance (just lots of book smarts I guess people in the US would say) I am not undertaking this project alone, which is the reason behind the correspondace with other people I know who have built and flown countless solid and hybrid designs. Using an oxidiser to pressurise a fuel is a bit silly I know, But I was assuming that with a solid sealed (O-rings) bulkhead between the two would alleviate any concerns, expecailly considering that the rocket would only contain around 50g of fuel (kerosene which is the least reactive of available fuels) and that the nitrous would be criogenic, so it would not only require a ruptre in the solid 'floating' bulkhead but also a very large and sustained heat/flame presance to get the nitrous up to it's (high) decompostion temperature and the autoignition temperature of the kerosene. On the other hand though a pressuriser of an inert gas would probably be a better idea, but the use of N2 would be another problem as it's vapour pressure is 3000psi IIRC which would require a significantly heavy (read thick, using Al) fuel tank.

As for breaking mach with sugar rockets, this is no problem as they are realatively fast burning and I have heard of other rockets passing the speed of sound on H motors (with a K being 16 times the total impulse of a H motor) and i have used rocket simulation software to see how much power would be required to get the ramjet fast enough (look for wRASP software) The ramjet payload would not even be that heavy, only around 700-800g, the main factor in getting this past mach is the drag created by the width of the motor which is many times that of the body tube (64mm diameter body sporting a 150mm ID ramjet) seeing as a ramjet is mostly (volume wise) a big empty tube, the heaviest parts would be the front shock cone and the fuel delivery systems.

As for moving this I am not sure if it would be a good idea to make a new thread in the water cooler, but there is one now, we should continue this discussion over there, can't wait for a reply ;)

[T_Pyro]

Coming down to lesser interesting things... (back on topic)
The resin/hardener epoxy formulation that I spoke of earlier, it turns out, can withstand burning candy propellant, as well as BP, so that part's OK. That should give an alternative to those who are out of options for materials to make nozzles from.

[MACE]

hi
the last days i also tryed to make nozzels with epoxy with realy great results. i used a mix of 1:2 epoxy:cement. i made a 5mm nozzle in a 23mm motor filled with 35:65 sugar kno3. after the burn the nozzle diameter was 6,5mm. i think this is really good for a epoxy nozzle.
MACE

[Blackhawk]

http://www.inverseengineering.com/Pages/2003/1115/1115%20Static.html
If you have a look there, he is making his nozzles out of a KNO3/Epoxy formulation to give tracking smoke (the nozzle burning) after the rocket has burnt, it does however mean that the nozzle throat errodes far more than it would with something such as putty, but hey if you want to find where they land again...

[tranquillity]

I have been attempting to make rockets using this fuel formulation:
75 KClO3
25 Sugar
3 Fe2O3

The other specifications of my rockets are:
12mm inner diameter
10cm long
4mm drilled kitty litter nozzel
~40cm bamboo garden stake is taped to the side to keep it flying straight

I have overcome the problems I was having with explosions and straight flying but now I have another problem which I can't seem to solve. About halfway through the rockets burn (about 40m in the air my best guess) the rocket seems to come to a point where it doesnt have enough thrust to continue flying and comes straight back to the ground still burning.

If I drill the core any deeper than I am already or use a 3mm nozzel the rocket will explode either on the launchpad or about 2m in the air. Making the stick smaller gives the rocket a much less reliable flightpath and since it takes off easily shouldnt be an issue if proper thrust can be maintained throughout the burn.

My question is: Are there any simple measures I havn't thought of that will enable my rockets to fly continuously until all their fuel is used up?

[fluoroantimonic]

Use a stronger housing and drill the core deeper and reduce the nozzle size... More pressure = more thrust, pretty much your only option is to increase the pressure, meaning you need a better container.

What are you using as a housing?

[tranquillity]

I am using paper held together with PVA rolled up on the same size dowel I use to press the powder. They have about 4mm thick walls. I have now gone back to 3mm drilling very shallow core and they don't explode (actually barely take off) so I think more experimentation is required going back to 3mm nozzle drilling a gradually deeper core.

[-=HeX=-]

Normally explosions in the rocket engine are caused by small air pockets forming in the fuel grain which leads to faster burning, pressure spikes and then an explosion.

I saw that you are using almost the same propellant as the boys in 'October sky' used, however they added alcohol and cast it. Before adding alcohol and casting they had only CATO's. It was explained in the movie that air pockets forming in their mix caused their CATO's.

If you recover a fired engine check its nozzle to see has it been worn away, causing loss of thrust. Maybe no nozzle and full core simultaneously ignited.

[tranquillity]

The rocket I spoke of which came down halfway through the burn I recovered. The nozzle had almost no erosion and had a hard, dark, almost metallic coating on it (perhaps the iron oxide was reduced by the sugar but I don't really see that happening in the presence of so much oxidiser). I did another test with a 3mm nozzle this time it took off quite well, got about 4m up, then suddenly shot off to the side and flew away. I couldn't find it but I didn't hear an explosion either. Perhaps I did not drill the hole straight enough I imagine that would become more and more important as the nozzle get smaller.

I have not heard of "October Sky" is that a movie or something? I will try an alcohol cast as you suggest. How long do you expect that will take to dry or would it not matter since ethanol can be burned too? Should I add a little dextrin in place of some sugar to keep the mix together better?

[Bacon46]

You may also want to consider omitting the Fe2O3 and as Fluoroantimonic said, drilling the core almost the entire length of the fuel grain. (8cm) Fe2O3 causes the fuel to burn much faster. I have had better luck without it.

The rocket fuel I use consists of:
KNO3………………59%
Sucrose…………..29%
Fructose………….12% (Corn syrup)

I prefer Jimmy Yawns skillet method (http://www.jamesyawn.com/skillet/large/index.html) for making KNO3 rocket fuel. I wouldn't use this method with chlorates.

You probably already know this but I will throw it in anyway. A “bottle rocket” should balance on your finger with your finger placed 2 or 3cm behind the nozzle.

Were you trying to lift any type of payload with the rocket you mentioned?

[tranquillity]

I am familliar with the balance trick though I did foget to use it before firing. My rockets have had no payload as yet. I am trying to get the process reliable before trying to lift anything up with them.

I will try removing the Fe2O3 for my next batch if I still cannot get them to work I think I will go to KNO3 and Sugar rockets as you suggest. One of my aims of this project was to use a fuel mixture that didn't seem to have been used before and see if I could get it to work but I suppose a failure just goes to support why other people don't seem to use chlorates for this.

[-=HeX=-]

Yes, october sky is a movie. Its really good, plenty of rocketry stuff in it. Now I happen to have my source for Ammonium perchlorate and I am wondering what would be the best Ammonium perch formula for simple cored, maybe nozzleless rockets. I am thinking Ammonium perch, aluminum, iron oxide and sulphur bound with dextrin or simply rammed. I am not so good at coming up with a good fuel. Any ideas?

[Cobalt.45]

For ammonium perchlorate motors, you need to check out the high powered rocket sites for info on APCP motors. Their propellant is composed of ammonium perchlorate, an elastomer binder such as Hydroxyl-terminated polybutadiene (HTPB) or Polybutadiene Acrylic Acid Acrylonitrile Prepolymer (PBAN), small amounts of powdered aluminum, and various burn-rate catalysts.

If you can get ammonium nitrate, very good fuels can be made from it, as well. AN fuel works best with magnesium.

[Bacon46]

HEX

I've got 13 pages of Ammonium Perchlorate based rocket fuels taken from The Preparatory Manual of Black Powder and Pyrotechnics. It's a 3.7mb PDF but I can't get the file to upload as an attachment.:mad:

I can email it to you if you’d like

[waveguider]

If you can get ammonium nitrate, very good fuels can be made from it, as well. AN fuel works best with magnesium.

A friend of mine living in Eastern Europe is having good results with an AN and Aluminium based propellant.
Here are some details of his propellant:


AN - 60% fine ground (unknown mesh ball milled Fert grade prills)
Al - 20% 50 micron
Neutral (sanitary) silicone - 20%

Isp=239s at sea level.
Density - 1,66g/cm3
a=0.0273
n=0,338
r=1,3mm/s open air
Pressing at relatively low pressure /500-600kg/cm2 / or ramming
Mechanical strength is quite low.
This fuel was tested in motors up to 38mm with great results.

Notable things about this propellant is that it works very well in a vast range of Kn=100-300 and where the pressure is from 1MPa to 5Mpa and burning is stable.
The combustion temperature is very high /2800*C/ and graphite nozzles or inserts are needed.Also powerful igniters are required for good ignition, He's been using Nakka's ''spit fire'' igniters, come to think of it, Nakka is working on AN and Aluminium propellant over on his site.

[Cobalt.45]

I applaud your friend for obtaining the results you post.

Nakka has struggled w/this type comp for years now- Nozzle erosion is heavy and lighting them problematic as you've indicated. Forming it into grain required all sort of gyrations, as well. He has stalled currently w/a promise to get back after it at a later date.

I know of no more successful fuel of this type than:
Wickman Propellant
PSAN 60%
Mg 20%
R45HT binder 20%

[fluoroantimonic]

Speaking of rockets, here is an interesting site:

http://www.student.montefiore.ulg.ac.be/~teney/h2o2propulsion.htm

[tranquillity]

Experimental Method
15g of finely powdered KClO3 was added to a bowl with 5g icing sugar and mixed thoroughly. 1mL additions of ‘Diggers Paraffin Oil’ were made in an attempt to bind the mixture with thorough mixing in between each addition.

After 5mL the powder had taken on a slight grey appearance and formed a coherent, but slightly crumbly, mass when pressed against the bowl with a spoon. At this point 10g was isolated for addition to a test rocket. (Comp. 1)

0.5mL additions to the remaining mixture were continued as before. After another 1mL was added the mixture was darker grey and quite transparent in thin slices when pressed against the bowl. Additions were stopped. (Comp. 2)

A burn test was conducted for each composition. Comp. 1 ignited easily from a match and burned producing a tiny amount of black smoke and leaving an oily residue on the brick. Comp. 2 was also ignited with a match but with more difficulty and burned softer also producing an oily residue.

Both Comp. 1 and Comp. 2 were loaded into a 12mm ID paper tube by loading a small amount at a time and hand pressing with a wooden dowel. About 10g of each comp would have been loaded. A 4mm drill bit was used to drill a nozzle and core at a depth of the entire length of the drill bit and a short length of chlorate-cotton fuse was inserted.

Comp. 2 rocket was taped to a counterbalance stick and setup on the launch pad. It ignited and burned producing white smoke and no exhaust flame. It did not leave the launch pad. After burning the nozzle had a ring of slag around it.

Comp. 1 was setup in the same way. It ignited and burned lifting off easily. Unfortunately the top plug on the rocket burst about 3-4m off the ground prematurely ending the flight.

Conclusions
Comp. 1 ratios – 15g KClO3, 5g Sugar, 5mL paraffin oil was a good performer but overall inconclusive due to the flight ending destruction of the end-plug.
Comp. 2 ratios – 15g KClO3, 5g Sugar, 7mL paraffin oil failed to take off.

Further
More testing required with Comp. 1
Performance may be enhanced if needed with the addition of more KClO3 to OB or a few % transition metal oxides (Fe2O3, Cr2O3 or MnO2)

As usual any questions, comments or suggestions are welcome.

[waveguider]

I applaud your friend for obtaining the results you post.

Nakka has struggled w/this type comp for years now- Nozzle erosion is heavy and lighting them problematic as you've indicated. Forming it into grain required all sort of gyrations, as well. He has stalled currently w/a promise to get back after it at a later date.

I know of no more successful fuel of this type than:
Wickman Propellant
PSAN 60%
Mg 20%
R45HT binder 20%

Ah yes PSAN, unless you experience temperature of above 32 C, which is around the phase change temp of AN, then you do not need phase stabilized AN. Mg is just too expensive.

My friend uses FGAN /fertilizer grade 34-0-0/ ,granulated. It consist 0,5% MgO as a stabilizer according to the information provided by the local manufacturer.

[AN is in the form of rhombohedral crystals at room temperature but changes to monoclinic crystals (larger) when heated above 32 degrees Celsius]

I've been in contact with him since and he has this to add:

''New formula AN,SI,AL. 3N
AN - 67%
NN* - 3% /Sodium nitrate/
Aluminium - 18%
Neutral silicone - 12%

*My friend is from eastern Europe and so NN=''natrium nitrat'' IIRC.

In a small motor 25x150mm with 60g propellant.
Kn value was on the low side ~100.
My small rocket flew seemingly well with burning time around 4s.''

Heres a video that he made of this different propellant.

http://www.youtube.com/watch?v=ZzaL0r1LwXQ''


The mixing process of AN
- I grind the granules up to 0,5mm size
- I dry it in oven at a temperature 90-100*C for about 2 hours
- I grind finally the granules up to 50 microns
- I mix the silicone with Al first,then i add the AN from above
Commence long stirring by hand until it moves from wet sand consistence to thick paste.
The Mixing process is a big challenge,but not impossible.
Pressing by hand or ramming directly to the motor case.
I leave it to cure overnight and then I carefully and slowly drill a core.

In the other formula's 70/20/10 or 70/18/12 with less silicone content,
I drill immediately without waiting for curing.

I use this propellant in small motors up to 38mm without any problems with phase changes of the AN.



Silicone N has much better oxygen balance than HTPB. It releases oxygen with hardening which compounds are very efficient depressants of the exponent “n”.
(I'm not sure what he's trying to say here sorry).

Here's a picture of one of the grains.
http://i8.photobucket.com/albums/a30/sequesteredfishy/ANSIAL.gif

The aluminum was about 20-30 microns.

I'm sorry if there are grammatical mistakes in this post[I can not think straight right now, too much grog]