16 replies to this topic

[PyroNitrate]

I saw theys little spinny things that were a circle and had fused rapped in it. It looked sota like a top, when the fused burned it spun faster and faster and launched itself into the air, when in the air it started to wistle and turned green, spun faster and exploded all in a thing the size of my fingure, i thought that was some pretty cool stuff! I was wondering what the best chemical to use for launching things in the air. I have had BP get some good height with a flash bang then burning sparks but was not good enough because the tube that held it went up with it . I want to be able to launch something out of the tube while it is still on the ground like you see in firework shows. I know i just rambled alot, so to the point i wanted to know what is the best launching powder to do this with? -Nick

[Richard H]

All fireworks use blackpowder as a lift charge. Not really sure what the heck your on about to be honest, sounds like some kind of helicopter.

[PyroNitrate]

yeah, it was a helicopter, now about keeping the tube on the ground for instance roman candles, they shoot flying sparks and then explode etc whiel you are holding the tube, how is this achived, how are they launched out of the tube?

[adamw]

then explode etc whiel you are holding the tube

I hope not! Firstly, I think you should do a lot more reading. How are they launched out of a tube? How do you think cannonballs were fired from cannons? Things havent changed much. Having the wealth of information that is the Internet and then asking how a firework is launched from a tube makes you sound not so smart. Look it up and then ask some more sensible questions.

[Jerronimo]

I'm planning to make a mortar, and want to use granulated H3 as a lift charge.

Has anybody got any experience using this formula as a liftcharge?
I want to launch some 2? inch shell's(about 160 gram)and would like to know how much I would have to use.

[a2wpyro]

if you would like to know how to build a roman candal i will tell you.

tube (length needs to bigger than width)
1 end plug
carboard discs to fit down te tube (amount depends on how many shots)
stars to fit the tube
delay powder
black powder
1 fuse that is longer than the tube
glue (best would be a quick drying 1, i use a hot glue gun)

In this guide i will be working from the bottom of the tube to the top.

Cover one side of the fuse with your glue and make sure it is stuck to the side of the tube all the way to the bottom, once dryed pour wanted amount of lift powder into the bottom of tube.
Then insert a disc with a small cut on the side so it will fit over the fuse.
Now apply delay powder and 1 star over the 1st disc .
Insert another disc on top of the star.

This is a rough guide on making 1 shot for a roman candal

If you are woundering what delay powder is, it is:
60%potassium nitrate
25%charcoal
15%sulphur

Well i think this is the right formula, correct me if im wrong.

[Richard H]

You seem to have forgotten to mention the critical process of consolidating the delay powder and seating the star with a rammer.

What is the point of using BOTH delay powder and an internal fuse? In roman candles it is usually common practice to use one or the other.

Internally fused candles seem to be typical of Chinese constuction, while in the west a delay comp is rammed between the stars to be lifted. Alternatively, and somewhat more commonly felt wads and time fuse are used to get a very reliable high performance candle.

Also, please try to find a thread relevent to candles, as this thread is about lift charges. I suggest you read the user guide forum before continuing any further.

Could you please check your spelling, punctuation, and grammar before posting. Thanks.

[Bub]

I'm planning to make a mortar, and want to use granulated H3 as a lift charge.

Has anybody got any experience using this formula as a liftcharge?
I want to launch some 2? inch shell's(about 160 gram)and would like to know how much I would have to use.

J,

Why would you want to use something as dangerous as H3 for the lift when BP lift will do the job just fine ?

There is really no necessity to risk your limbs with H3.

If you make the BP lift correctly and ensure the grain size is big enough then it will easily lift your shell from a strong tube.

I recently tested a batch of lift using an empty 3" shell weighing just over 500gms and the BP lifted it to a fair old height (using only 1.5oz of lift)

The -very poor- video (160k) is here :-

http://www.elporron.net/500g-50g.WMV

Unfortunately is was a very foggy day and filmed at dusk. This video is slowed down somewhat so that you can see the lift firing.

Let us know how you get on

Edited by Bub, 29 December 2003 - 03:02 PM.

[robert johnson]

Absolutley I can not agree more when it comes to life or limb please make sure that when staking mortar tubes to the ground they aredone so correctly especially 8" and over.

[BigG]

A good rule of the thumb is about 30g BP lift for every 500g shell. This will need to be modified according to the quality of the BP, grain powder and shell size/weight ratio, but you can just start with this rule and work is up or down to the materials you work with.

[robert johnson]

500 gms for a 3" shell is interesting, As I have yet to weigh a 3" shell weighing more than 180 gms, and the Spanish 3" canister Shells weigh in the region of 250gms, so when it comes to launching a 200 gm shell, this lift will be insufficent and therefore the shell will burst low.

Edited by robert johnson, 01 January 2004 - 04:08 PM.

[BigG]

500 gms for a 3" shell is interesting, As I have yet to weigh a 3" shell weighing more than  180 gms,  and the Spanish 3" canister Shells weigh in the region of 250gms, so when it comes to launching a 200 gm shell, this lift will be insufficent and therefore the shell will burst low.

Robert ? your post is quite confusing? How much lift will not be sufficient for a 200g shell? Also, in regard to a 500g 3?? shell, I agree that it sounds too much. I assume if was filled with something ? like sand, that weights much more then the usual content of a shell.

[Bub]

G,

You're absolutely correct of course - it was indeed filled with sand.

The sole purpose of the test was to see how much I could lift (and to what height) given a fixed quantity of lift charge.

Usually I'd not expect a 3" shell to weigh more than 200g or so, and therefore would adjust the lift accordingly.

Interestingly, ths 500g 'shell' goes to a significant height - it has more inertia from it's mass though so I suppose that's to be expected.

REgards.

[maxman]

About halfway down this page http://www.unitednuc....com/shell4.htm is a table giving a "ball park" figure for approx lift charges of BP for 4", 6", 8" shells both with homemade and commercial BP.

[robert johnson]

Bub, the reason the shell goes higher has nothing to do with inertia once the shell has left the tube, It is the Mass of the shell, the power of the lift and the speed at which the lift powder develops it power , if you had a 3"shell that weighed 5kg if it leaves the tube at the same speed as a normal weight shell it will reach the same height as the heavier one, the inertia only applies to the shell sitting on the lift.

Edited by robert johnson, 01 January 2004 - 08:03 PM.