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black powder rocket anyone??

Unread postPosted: Tue Apr 10, 2007 8:23 pm
Author: spudthug
well i am basically a pyrotechnical guy....i do alot with explosives and pneumatic i dont know if i am aloud to post this here so ban me if u must pcguy...nvm dont ban me just delete the post...ok well basically it is a quick connect with a 1/4x1/8 reducer..a 1/8 nipple...a 1/2x1/8 reducer and a paintball tank cap...

had to edit out instructions for safety conerns ull have to figure out how this works by urself or dont at all...

all i can say is that u fill it and light it and it flies and ges boom...

Unread postPosted: Tue Apr 10, 2007 8:27 pm
Author: schmanman

did you even read the rules?

solid propellent discussion not allowed on this forum.

Unread postPosted: Tue Apr 10, 2007 8:29 pm
Author: spudthug
actually schmanman it is solid propellents in a potato launcher... look for my polish cannon on here...ill try to find it and post a link so there u go....mmkay??

EDIT: sorry about the smartness schmanman but i had an outburst because i was ticked at my mom...anyway i jsut dont like it when people tell me to read the rules when they actually dont know them..

theres a link for u if u never saw it

Discussion of solid propellants, explosive devices or incendiary projectiles fired specifically from a spud cannon is prohibited

Unread postPosted: Tue Apr 10, 2007 8:42 pm
Author: iPaintball
Just make your rockets out of cardboard tubes. I get mine from

Unread postPosted: Tue Apr 10, 2007 8:48 pm
Author: sandman
well, first of all, booster model rocket engines are made with black powder so you are fine

lol, ill take my model rockets over that though

Unread postPosted: Tue Apr 10, 2007 8:51 pm
Author: spudthug
yes but this works ten times better than cardboard tubes...if u work with gunpowder alot u should know how this works....all i can say is that if u look at my rocket u can see there is a big chamber to store the powder...a small diameter nipple connecting it to a second yet smaller chamber so the gases are forced into larger area and the back to the quick connect that is small again that propels it..kinda doesnt works for potato guns...i tried...only with rockets....

note: above paragraph was rambling if u do not know what i am talking about...oh and if u are doing this (*[{dont}]*) dont do it with out proper measuring u will die if u dont...5 grains over and u have urself a pipe bomb...

sand....model rockets are less powerful than this if u get the right measurements...i guarentee u this little device is bette than a small model rocket engine by far..and it is reusable and reloadable...

my larger models i am not going to post....they are huge....does the army want any big a** missles to shoot randomly???

it would be a waste using them on they dont explode so they would only take out one may go through a wall though...

Unread postPosted: Tue Apr 10, 2007 9:50 pm
Author: Blitz
spudthug wrote:it would be a waste using them on they dont explode so they would only take out one may go through a wall though...

Unread postPosted: Wed Apr 11, 2007 8:31 am
Author: BC Pneumatics
Spudthug, I got four words for ya: Power To Weight Ratio.

Also, try writing in a more understandable, incoherent fashion please.

Unread postPosted: Wed Apr 11, 2007 10:37 am
Author: SpudBlaster15
I highly doubt this works better than a properly constructed 'cardboard tube' rocket.

For a solid fueled rocket to work well, the propellant must be cast or pressed into a solid grain to create more even, consistent, and prolonged thrust. Simply filling a chamber with black powder grains is more likely to create a pipe bomb, unless you have extremely shitty black powder. If it doesn't explode, it is likely to produce a split second of thrust, as it fires all of the combustion products out of the nozzle at once. Not much of a rocket if you ask me.

Aside from having terrible aerodynamic qualities, I doubt it even flies anywhere close to straight.

Unread postPosted: Wed Apr 11, 2007 2:32 pm
Author: cannon freak
For building any kind of homemade rockets black powder really isn't the best option, sucrose and potassium nitrate melted together make a much better fuel, maybe not as powerful but definitely easier to cast and get a good density, its quite hygroscopic so water can ruin it.

Cannon Freak.

Unread postPosted: Wed Apr 11, 2007 4:59 pm
Author: BC Pneumatics
I disagree cannon freak. While KNO3/Sucrose is good for a beginner (As spudthug certainly seems to be), black powder is a far better propellant, and pressing it is no harder than casting a sucrose based grain IMHO

Unread postPosted: Wed Apr 11, 2007 5:19 pm
Author: homeflake210
Thats kinda a half ass rocket lol. Try using like 1" PVC and an Aluminum dowel for a nozel, also I think meal powder works better than black powder granules.

Unread postPosted: Wed Apr 11, 2007 6:56 pm
Author: boilingleadbath
Isn't the ISP of sucrose-KNO3 higher than that of black powder by about 50%? (ie, 120 vs 80)

Not that I know much about rockets, so I'll just cite the fact that hezbola used it in their rockets instead of black powder, which probably means <i>something</i>.

Unread postPosted: Wed Apr 11, 2007 7:15 pm
Author: BC Pneumatics
BLB, A propellant's ISP is one of many factors that needs to be considered. Thrust, burn rate, etc, are also important.

Unread postPosted: Wed Apr 11, 2007 8:12 pm
Author: cannon freak
BC Pneumatics, I have to disagree I think casting a sucrose/potassium nitrate propellant is much easier than black powder although I have never personally made a black powder rocket wouldn't you have to use some kind of a binding agent? or would you simply pack it tightly, if packing it it would require quite a bit force to get good density would it not? The (Candy Propellant) on the other hand requires only that you melt it together. Its not as dangerous as you would think since its melting temperature is far from the ignition temperature. Then just pour it into the mould to cast it which requires no press.

You can always increase the burn rate with a little Iron Oxide additive.

I believe increasing the chamber pressure will increase the ISP as well.

Spudthug, you should really give it a long thought, shooting rockets out of a potato gun is just a plain bad idea. First of all your design seems very crude and being made out of metal is never a really good idea. Having a metal chamber does increase the pressure that is can hold but having a metal rocket motor CATO is always bad.

As SpudBlaster15 said, are you even pressing the powder into a solid? If not I agree with him you will probably have a CATO, not only with metal shards but with PVC/ABS or whatever your gun is made of coming at you.

I seriously urge you to reconsider what your doing because as far as I can see that thing is little more than a pipe bomb unless Im missing something.

Cannon Freak.