1569 replies to this topic

[karlfoxman]

Nice too see you here again Sprengman, fantastc shell. I would love to see pictures of the build if you have any. One day soon i hope to move onto 8 inch ball shells, got a 6 inch getting built. Orange and purple shell of shells. I remember seeing your 6 inch shell of shells, what you got planned next?????

[Sprengman]

I don?t know what I want to do next.

But I?m sure that it would?t be greater than 8"

The last year I don?t made much pyrotechnic things because I build model airplanes and jetengines. Let?s look this year....It?s possible that I go for pyrotechnics again

[Karl]

I just tried to fire my first 2" Can Shell!

The shell was a little under 15cm long and weighed 375g. I used 20g of granulated 3F Blackpowder for my lift charge that was housed in a liftbag.

The shell used 3F blackpowder for the burst-charge which was inside a thin walled tube, surrounded by my hand rolled Titanium Streamers. I primed them with BP just to make sure they lit.

But I slipped up on using a correct time fuse. I used my own blackmatch, that had Dextrin + Titanium Shavings added. I planned on it creating a streamer like trail but not this time!

I think the pressure from the lift forced the Blackmatch to burn quicker than it would do normally and it flowerpotted as soon as it left the mortar. The shell then did it's 'shell like' thing and made a pretty bassy boom and blew the stars everywhere. The burst was pretty symetrical!

I found the shell after firing it, and it had completley unwound itself down the spiral, I think I need to use flash powder instead of BP next time!

[Yugen-biki]

Hello everyone!

I have not posted in this thred for some time, but I have beed reading it every now and then. And I must say that I enjoy all nice videos and pictures of shells you guys have made.

Here is my contribution (the 6", not the three 4" shells):
Picture:

Video:

Info:
Conkling white glitter (I used <44 ?m Sperical Al)
H3 with 15g 70:30 flash
3 second time fuse
Total wheight 1100g
80g lift charge
And this time the rising white comets worked! I dipped them in a BP + NC-laquer slurry. Comets were made of a modified verison of shimizus?s white comet containing Al coarse flake and pot. perc..

Edited by Yugen-biki, 05 January 2006 - 08:55 PM.

[JamesH]

Yugen-biki - you really have got your 6" shells perfected! What an excellent shell, I cannot see a single thing wrong with it! The symmetry is perfect!
Those conkling glitter stars are very nice, is it Formula I. on page 151 of "chemistry of pyrotechnics"? What type of Al and charcoal did you use?
What formula was the white rising tail comets?

I am duly impressed with that shell!

Edited by JamesH, 04 January 2006 - 05:58 PM.

[Jerronimo]

Yugen that was a wonderfull shell, very nice break and deep report.

I launched a 4'' shell tonight, it was a gold streamer with blue pistil stars.
specs:

4'' plastic ballshell reinforced with fibreglass strappingtape
outer stars: 11mm gold streamer
inner stars: 6mm chlorate blue
breakcharge: bp/hulls 5:1 with 4 grams of perchlorate/benzoate wistle
delay: 3 sec. spolette
lift: 35 grams granulated BP
shellweight: 370 gram

In real life the break looked huge, and all stars lit perfectly I think.
We recorded it with two camera's, this:clip was recorded with the video mode of a konica dimage x1, good quality for a photocamera I think,sadly it wasn't captured perfectly.
A friend of mine recorded it with a normal videocamera and got it perfectly on film, he's also the one speaking at the end .
I will try to get it on the PC with a good videocapture card.

Edited by Jerronimo, 04 January 2006 - 09:10 PM.

[riptheory101]

LOL

That was a sweet shell

hope mine come out like that as soon as my shells get here

[sizzle]

Wow, I really must try a shell of my own someday soon, I need to perfect my rockets and fountains yet. Does anyone know why it on sprays for five seconds then just shoots out hot gas for ages with a 8" flame jetting from the nozzle?

[riptheory101]

Cool, Any vids

[sizzle]

I will try and get one next time I do a fountain. It could possibly be Tuesday.

[karlfoxman]

Beautiful shells lads, more more more its great to see some commercial looking stuff going up. Makes you think how much work goes into these things, the fine tuning. Love the blue pistil, next double petal?

[Jerronimo]

Yes double petal would be nice, but it's hard to get that right in a 4'' shell because of the limited space you have.
A silver streamer with red or green magnesium inner petals would look awsome I think.

[Themolehole_9876]

What mesh is the best for lift powder? does it make much difference? Also, atm it only lifts about 1m outta the tube. Im using balsa as my charcoal but i dont actually have a ball mill yet so i have been just using a mortar and pestle while i make my ball mill. Is this the problem?

[sizzle]

Really for lift powder you need to ball mill (as I have sadly found out), I use a sieve for my lift granules which I would say is between 10 and 20 mesh and mine works perfectly now. The reason it doesn't lift out of the tube properly is again probably down to the fact that you haven't ball milled your lift.

[Kevin J]

Karl, yes using blackmatch does not work for the time fuse on shells, whenever I tried it on my micro shells, they went off in the morter like a mine.

Yugen-Biki, nice shell, and thanks for the picture