5 replies to this topic

[GZ22]

I came across this whilst merrily surfing Youtube, and thought I'd share it with you all. Some good quality filming of a display, with some excellent stills too.

http://www.youtube.c...feature=related

Enjoy!

Edited by GZ22, 29 May 2008 - 10:21 PM.

[cooperman435]

I just came across this when folowing on from the last video.............

Largest firework display

Can anyone offer any suggestions as to the design of the blue "swirl" shell that goes off at 2.15 in the left top of the frame. For the life of me I cant figure it out!

[FrankRizzo]

That's a "snail" shell. Both halves of the shell are filled with burst, then the stars are loaded in a spiral fashion at the equator where the two shell halves come together. To keep the pattern from shifting during handling, the stars are usually wrapped in a thin tube of tissue paper placed in the desired shape. It's much the same as making a smiley face or heart shape. Cheers!

[cooperman435]

But the video clearly shows a spiral forming not just a spiral shape expanding which means it has to be made from a rotating point ejecting stars rather than just a shaped burst.

[FrankRizzo]

But the video clearly shows a spiral forming not just a spiral shape expanding which means it has to be made from a rotating point ejecting stars rather than just a shaped burst.

No, it's much simpler than that. The inner spiral pattern expands with the burst...the stars further from the center are propelled with more force from the expanding gas envelope. The stars that make up the blue sphere after the spiral has burned-out are just layer along the inner surface of the shell and coated in a thick layer of a dark prime so they don't appear until later. Does that make sense?

I think there's a post on rec.pyrotechnics that details the construction of these shells. I'll do some searching and get back to you.

Edit: The shell referred to in the rec.pyro post is a significant upgrade of the basic technique that you saw in the YouTube video, but using precisely rolled color-changing stars. It will blow your mind.

A still frame from John Reilly's video:


The actual video: http://pyrotechnics....24jud02_low.wmv
The relevant discussion: http://groups.google...1f3b25fcd0f887/

Edited by FrankRizzo, 30 May 2008 - 03:14 AM.

[xXPyroJoeXx]

OMG That last post was awesome! How in the world that is done is beyond me XD Nice videos people, keep them up