1569 replies to this topic

[karlfoxman]

You are correct mate, thats the way to do it. Stars will stay in place that way. The flash booster should blast everything out a good distance and the template should keep it all in place until the break! I like to show other people the contents of the shells because its not as easy as dumping a load of stars in and the adding break charge. Im glad you like the pictures, ill post the vids when I fire them. The sun and planets version 2 should be good and quite loud! Well the bottom shot will be! Ill post more of the construction as i've been asked how the stars a arranged inside the sun break. Watch this space my fellow pyro's!

Karl

EDIT: Some pictures of the 2 ring beraq shell, red flash ring and then white. First delay is 1.5 sec second is 2 sec. Should be a nice suprise.

Second set of pictures show beraq delay, the delay is made from 4 parts fast willow blackpowder and 1 part redgum. Then mix with meths and make paste, the paste is pushed into a 2.5mm hole until it pushes out the hole like a 'poo' This beraq is for the sun and planets, they just require a prime of granulated lift.

Last set of pics is the stacking of the veline orange 1" comets in the sun break. Should be nice bright orange! It weighs just over 1kg and thats just the comets! The very last picture shows how important it is to have the comets 'lock' into place, they should not be able to move and if any gaps are present you need to use slices of wood to make everything fit very tightly. The gaps between the shell wall and comets will be filled with sawdust. The strength for a shell like this is in the stacking of the comets. Imagine the force put on this shell as the lifting shell explodes bearing in mind the finished item will weigh in the region of 3-4kg. Thats a huge pressure on the shell, any defect in build/design will lead to failure.

Edited by karlfoxman, 04 August 2006 - 07:06 AM.

[BrightStar]

Well, here is my first post to the forum - hopefully with many more to follow. I feel honored to be a member with so much expertise in evidence and so much to learn.

This 3-inch cylinder was my first shell as a beginner, launched six months ago for New Year 2006. As my first minor pyro success it has sentimental value, even if it was not very proficient. The powder was made the hard way with just a pestle and mortar (no mill). The BP for the 25g of lift and 100g of 4:1 coated corn cob burst was made in 4 small batches, each hand ground for about an hour. The 120g of pumped D1 glitter stars were also hand ground, with some atomised aluminium screened in at the last stage. The shell was approx. 300g after spiking with strong twine and pasting with 8 layers of kraft. Time fusing was an inch of hot visco wrapped in electrical tape. The shell case was 2.5 inch postal tube with epoxied hard-board end caps, the mortar a 3 inch postal tube, reinforced on the outside with all the kraft paper I had on hand.

The shell was fired by my little sister (as you will hear) on a 330ft command wire using an Xmas bulb / BP / NC lacquer ignitor - you will note the delay caused by my poor quick match.

The break was huge, and while not exactly a perfect D1 glitter (more of a willow due to the coarse mesh charcoal), and not symmetrical, it was certainly spectacular. The mortar barely survived. Here's the vid:

3-inch cylinder shell

Hope this gives encouragement to others starting out in 'the art'.

Edited by BrightStar, 04 August 2006 - 11:35 PM.

[karlfoxman]

Fantastic shell! Well done, looks like you got it all working. Also from your post you worked safely which is nice to see! D1 Glitter is a very nice star composition to use, good luck with any other shells you make.

[karlfoxman]

Me again, I have one more cylinder shell on the build. Was going to make another 5" but decided to go one up. 6", the effect is planned to be. 52 veline blue 1" comets and a solid star pattern in the center, the colour of the star will be red. Its an effect that we learned how to make in Malta. I have one picture if the shell case I have rolled, its 5" long and has 3 solid disks glued at one end. These will be where the 3 second Spoolette will be placed. I will take pictures as I go if I can.

[italteen3]

Have you considered changing your username to "Il Animale"?

Brightstar I loved the shell!

Out of curiosity Karl I have been getting as heavy into pyro lately as I can without a drying box and was wondering what shell building literature you have?

[Karl]

Again Karl, absolutely outstanding! Beautifully made and those stars drying look damn sexy

[BrightStar]

Karl, thank you for your kind words - I hope to reach your level some day!

I have a more recent batch of plastic 3" ball shells to post. The shells were 100 - 120g, lift 8.5g, spiking with fibreglass packing tape. Timing was approx 1/2 inch of visco and the burst 4:1 BP on corn cob with a 2g whistle booster. Some had simple Chrysanthemum 6 comets.



The first used a simple nitrate flash no. 5 star formula (50% KNO3, 30% sulphur, 20% atomised aluminium), step primed with BP. This was surprisingly effective - a very bright liquid fire which burnt to the ground. Given the low cost of this formula, it could be very good fired as a salvo to fill the sky with hanging stars as a backdrop to larger shells.

3-Inch Nitrate Flash no.5 Ball Shell

The next was my latest D1 glitter. The composition was milled for 30 minutes, with a third of the charcoal rough ground to approx 40-mesh and added for the last 5 minutes of milling.

3-Inch D1 Glitter Ball Shell

I also tried a magnalium orange based on the United Nuclear / Desert Blast formula. As they promise, this is the brightest pumpkin orange you will ever see. I tried to cut this to approx 8mm, but ended up with a wide variety of star sizes - something to improve. These were step primed with BP.

3-Inch Magnalium Orange Ball Shell

A question for the forum: My plastic shell cases have mouldings for a 1/2 inch length of visco. This gives me a delay of approx 1.6s which seems a bit too short. How would you lengthen the delay with these cases?

[karlfoxman]

Lovely shells, loved the glitter one. it looked fantastic! Well done, your doing very well. Your lift is capable of doing the job! How much lift you using, do you have a rule of grams of lift to every 100g of shell weight. I dont use this rule for my maltese shells they have a spiked lifting shell and wad/piston to maximise lift/powder. Works very well, anyone making this size shell will find it uses less lift and lower quality lift but can send heavy weight shell very high!

[karlfoxman]

Karl, thank you for your kind words - I hope to reach your level some day!

I have a more recent batch of plastic 3" ball shells to post. The shells were 100 - 120g, lift 8.5g, spiking with fibreglass packing tape. Timing was approx 1/2 inch of visco and the burst 4:1 BP on corn cob with a 2g whistle booster. Some had simple Chrysanthemum 6 comets.



The first used a simple nitrate flash no. 5 star formula (50% KNO3, 30% sulphur, 20% atomised aluminium), step primed with BP. This was surprisingly effective - a very bright liquid fire which burnt to the ground. Given the low cost of this formula, it could be very good fired as a salvo to fill the sky with hanging stars as a backdrop to larger shells.

3-Inch Nitrate Flash no.5 Ball Shell

The next was my latest D1 glitter. The composition was milled for 30 minutes, with a third of the charcoal rough ground to approx 40-mesh and added for the last 5 minutes of milling.

3-Inch D1 Glitter Ball Shell

I also tried a magnalium orange based on the United Nuclear / Desert Blast formula. As they promise, this is the brightest pumpkin orange you will ever see. I tried to cut this to approx 8mm, but ended up with a wide variety of star sizes - something to improve. These were step primed with BP.

3-Inch Magnalium Orange Ball Shell

A question for the forum: My plastic shell cases have mouldings for a 1/2 inch length of visco. This gives me a delay of approx 1.6s which seems a bit too short. How would you lengthen the delay with these cases?

I would drill the hole out and either use chinese delay fuse. Or you could wrap the visco into tight fitting gummed paper. This will block the flame from burning on the outside. So the length of covered visco will be your delay. This is what I have done to get accurate timing on multi shot fanned candles.

Italteen: He he I could do, but for now im know as Karlfoxman! Me and my pyro buddy have about three books one being Lancasters 4th edition. I gained my knowlage from 10+ years experience with very small fireworks. I learnt alot of mistakes when I was building tiny tiny 15mm shells, I had problems with ignition and other thins. When I started there was no Internet and I never knew of any books on the subject, I really did think I was 'the only pyro in the village.' Since then I have been designing shells and reading all sorts of manufacture notes. I admit going to Malta was a big eye opener and I took away alot of knowlage and tricks of the trade. We are lucky we had private factory tours, we studied alot while we were there. My head was filled with info regarding the amazing fireworks they make. When you look in their shells it makes sense why they are building them the way they do. Small things like locking comets in place make a huge differance, even the type of twine they use will make a massive differance. My only hope is someday I will be able to leagally show people what an amature pyrotechnic can do. To sum it up, SKYS THE LIMIT!

Edited by karlfoxman, 07 August 2006 - 07:08 AM.

[BrightStar]

Thanks Karl - I'll try wrapping the visco with gummed paper but might have to drill out the casing - an extra 5mm of delay length inside the shell is all I need.

The lift BP for the ball shells was nothing special, just meal riced to about 20-mesh with 3% dextrine to hold it together. The charcoal was a 50/50 blend of artists willow charcoal (soft, clean burning and very fast) and some home made willow from the local river bank (not so clean burning but much cheaper), damp milled for 3 hours. The lift was contained in a thin plastic cup, glued to the shell, so I guess there was some confinement but nothing compared to your Maltese lift methods. I also wrap the whole shell with kraft paper (not shown in the photo) before use, and this provides quite a snug fit to the mortar.

I had thought that 8.5g might not be enough as I have seen 10 - 15g quoted elsewhere, but just used 1/16 shell mass with 33% extra for luck as they were small-ish shells. I guess this is about 1/12 shell mass then - the 21 inch long mortars helped. As these were my first 3-inch ball shells, I don't really have a rule for this yet!

[karlfoxman]

It will work, I used the same delayon a 6" purple shell of shells. The timing was very good so it works. Some people will remember it! Lol, oh and Adam the challenge s still on and cofident it will be done! he he.

Edit: Here are the comets for the 6 inch shell, they are veline blue. Over 1kg of comp here!

Edited by karlfoxman, 07 August 2006 - 08:56 PM.

[karlfoxman]

Alittle update on the sun and planets shell, its complete apart from lift charge. Here is some pictures, I decided to leave the bottom shot out. So its shorter than it would have been. It weighs in at 1.8kg and will lift with 100g maltese style 4" lift shell. Also need to cut the piston and add the shock wadding. Then final wrap.

Some more pictures, the 6" blue comets w/ solid red star shaped pistil and the beraq shell spiked.

Edited by karlfoxman, 09 August 2006 - 04:31 PM.

[leosedf]

I fired a 3 inch today. Total failure!
It only rised up to 10 meters and had a very bad timing (i have no timefuse or visco so i use spolletes).
The stars did not ignite...... Only 2-3 of them, they are Aqua stars (40:30 Zn, BP). I made tests before and they worked fine. The burst was coated rice hulls, total weight of the shell was 140gramms and the used lift was 25 gramms (i added more since the shell had 5mm gap in the mortar).
Result: low altitude, break on 5meters, no stars only a powerfull break.
You can watch the vid here .
Any ideas what i did wrong? Maybe the burst was too much..

Edited by leosedf, 12 August 2006 - 06:58 PM.

[seymour]

I have had mixed success with Zinc stars, some light easily, others need prime. I would definitely try priming those stars, or lower the zinc percentage, I doubt the burst was responsable for the stars blown blind.

With regards to the low altitude, there are a few variables, such as mortar length, but I'm fairly confident that the problem is lift quality. Lower quality lift requires a tight fitting shell to aquire a correct height. to pinpoint the exact problem a little more info will be needed ( charcoal used, grannulation, milling time ect.).

Spolettes are fine, I always use them and I know alot of other people do, just look at the Maltese!

[karlfoxman]

Yes spoolettes are widely used in Malta, they do use timefuse but no where near as much as spoolettes. I would say your lift powder was not up to the job, we have very fast lifting powder that is milled for 16 hours and uses willow charcoal. We are going to switch to Alder as soon as my 3kg arrives. Just a note on our lift powder, we use 12g per every 100g shell weight. This is more than enough but we found after research it was the ratio we would stick to.

As for my Maltese shells there is no rule of thumb, I found that about 1.5kg can be lifted with 100g of 5 hour milled willow powder, so I am using the rule 100g lift for 1500g shell. Bear in mind this lift is put into a strong spiked lifting shell and that a huge percentage of the gasses do not escape until the shell has left the tube.