5 " double petal purple shell with green pistil

[Karlos]

Outer diameter of main hemispheres: 130 mm

Diameter of core-former hemispheres 70 mm

Outer stars 13 mm purple magnalium composition binding with red gum coated on rape seeds + priming. Colored star cores only 9 mm.

Inner stars 7 mm green magnalium, binding with red gum.

Bursting charge KP with cotton seeds as carrier.

Filling by japanese technology with paper sleeves.

Kyoku do = 6 paper tubes (ID 15 mm, lenght 60 mm)with two stars on each end. 5mm red core coated in winokur 11 to 11mm.

Weight of shell with pasting and kyoku do = 1100 g.

 

http://img718.imageshack.us/img718/60/1propyroforume166.jpg

 

Video:

http://www.youtube.com/user/HajdaHanabi#p/u/7/_sYV2p2TkB0

Edited May 3, 2010 by Karlos

[Mumbles]

Very nice shell.

 

I've been experimenting with that same construction technique, but I constantly had issues with the inner sphere tissue paper tearing. Have you experienced this at all? I was using pumped stars at the time, perhaps they had too sharp of corners, despite being quite rounded from prime. I plan to play a bit more this summer, maybe double up the tissue sheet. When Shimizu describes this method, he shows that the tissue layer is wrapped with string. Your inner petal is obviously quite round as is, but have you experimented with confining the inner petal at all?

[Karlos]

Mumbles: Not, I had not tearing on paper.

I used method with wooden stake which prolonging the time fuse. Paper sheet is fixed on two points. No strings.

http://img18.imageshack.us/img18/7962/core010.jpg

look here:

http://www.japan-fireworks.com/gallery/yoeshin/makingreport.html

[TheSidewinder]

That was a gorgeous shell. Very nice job!

[dagabu]

Beautiful, simply beautiful, both in the construction and in the finished product. You could teach us a lot.

 

D

[PyroMan LTU]

Indeed, a master piece. Thats an interesting assembly technique, I've read about it in shimizu book, however never tried. I always fill two hemis full and then close them together.

 

PyroMan

[FREAKYDUTCHMEN]

Very well done Karlos. I've seen some pictures before on pyrobin and was curious about the result, and here it is.

 

Pyroman, this is just one way to skin the cat, the japanese are known as perfectionists, and this way it's quite impossible to see an equator of the shell in the air, (were no stars are). However this is much more time consuming than the spain/chinese/american way.

 

Pretty heavy shell for a 5" Karlos, the cottonseeds are quite a bit heavier than ricehulls, so that and the rising comets must be some reasons for the heavy weigth. I'm looking forward to see your next project.

[Karlos]

Freakydutchman: Shell with pasting had only 900 g. Bursting charge was by shimizu 1.4 :1 (powder : carrier) and in the shell quite 240g, 140 only powder without seeds.

[dagabu]

2# for a 5"? Sounds pretty good for weight to me.

[PyroMan LTU]

Agree, FREAKYDUTCHMEN I actually have tried it once on a 4in shell when I filled it up with 8x25mm crossettes - this was the best way to do it, since there wasn't much space and snaping the hemis together may cause problems. It performed pretty well.

 

Karlos, can you give some tips about operations #4,#5,#6? I believe, details are important here. I am going to work on 6in shells this year and this technique might come in handy.

 

PyroMan

[ExplosiveCoek]

Also your stars look quite uniform in size, what do you use to size them? Very nice shell!

[Karlos]

http://pyrobin.com/files/sito.jpg homemade separator from aluminum plate. If you need perfect stars and starting with rape seeds, screen is really necessary for small quantity of composition.

[Kraftpaper]

Great star sizer

[ExplosiveCoek]

How much of those screens have you got? And at what sizes do you screen your stars?

[Karlos]

I have follows: 5, 6, 7, 8, 9, 12 mm. I put sifted stars again to the tumbler and this method repeat time after time then all stars are uniform and stayng on sieve. For 3" shell I use 7 or 8 mm main colored or effect stars, and than I cover those cores with priming to etc 9 mm complete stars. japanese usualy uses cut stars as cores for rolling standard round stars - this is good and easy way , how to make uniform stars . If you use seeds as cores for small quantity of stars , the result will be acceptable only with separators. Edited May 6, 2010 by Karlos

[50AE]

Awesome shell dude! Really good stuff, congratulations! Keep up the good work!

[Dr Boom]

That was rather nice! The stars ejecting on the rise was very interesting and well timed- I've seen some rocket headers with such stars but never on a shell the way you put it together, spot on!

[thunderboy]

EXCELLENT I WANT TO LEARN HOW TO MAKE ONE OF THOSE

[dagabu]

EXCELLENT I WANT TO LEARN HOW TO MAKE ONE OF THOSE

 

Shhhhhhhh, dont yell

[angelluis]

This has to be one of the best technics i have seen for putting togehter these types of shells! Would love to learn this type of shell building someday when I am more advanced. Just lovely wonderful job!

[Zumber]

look up at 4th image are they only stars or stars with rice hulls coated with BP at centre

 

http://img718.imageshack.us/img718/60/1propyroforume166.jpg

 

Video:

http://www.youtube.c...u/7/_sYV2p2TkB0

[Mumbles]

Stars with burst at the center.

[Zumber]

Stars with burst at the center.

thanks..!!any video of whole process of building up the shell...??sounds construction is extremely complicated....

[Mumbles]

There is an excellent book on the process. Fireworks: the Art, Science, and Technique. By Dr. Takeo Shimizu. I'd suggest purchasing that, it is invaluable.

[dagabu]

Amazon has the lowest price I have seen, I got mine used from a pyro buddy for $60.00.