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Posted

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

Do you have PDF copy of that book.....I have searched that book but i havn't find double petel shell method anywhere....

Posted

Do you have PDF copy of that book.....I have searched that book but i havn't find double petel shell method anywhere....

 

 

it's there, Pg 246

Posted
Figure 99?
Posted
http://img69.imageshack.us/img69/4248/34247117.gifhttp://img69.imageshack.us/img69/4248/34247117.gifhttp://img69.imageshack.us/img69/4248/34247117.gif
Posted (edited)
opps Edited by handymanherb
Posted

Stars with burst at the center.

Mumbles i got tht diagram but insted of bp i found only stars allover the globe..

Will it work if we use star primed with thick layer of bp..??

Posted

I have some questions before I start making one of these.

How does the construction of the inner petal affect the burst?

From what I see, in this shell the inner petal is a non pasted, weakly closed 2" ball shell. Is this correct?

If the inner shell is pasted, will the break improve?

Posted
The inner petal is never pasted. You'd have to drill holes in it anyway for fire transfer. Firstly, that would be dangerous, secondly it would remove any additional strength. It is however somewhat common to spike or wrap the inner petal with string when building them inside out.
Posted (edited)

Here´s a part of a documentary. At 4.55 is shown, how they build up this inner petals. Seems you need some special paper for this purpose. It must be flexible.

 

Hanabi Part 2 of 3

Edited by Pyroboy
Posted

Thank you for the advices.

Because I can't make KP here, can I use H3? It's a strong break charge, but because we have a double petal shell, the burst charge is less than in a classic peony. I've already used H3 burst in 4" shells with success.

  • 3 years later...
Posted

just have a confusion here with time fuse.

in Shimizu book he says he uses paper tube which is later used to receive time fuse, once inner petal assembly finishes he says cut that tube near the surface of sphere (fig 12 page 247).

then later on he inserts that empty tube on time fuse tube.

so question is, part from center of sphere to time fuse is empty, how come we overcome this problem? because one end of that empty tube at center side of sphere is covered with thin paper.

how to insert pieces of black match, just like spolette we cant wrap paper and tie black match pieces around the tube.

Posted

If you read more carefully, you'll find out that it is not empty. See figure 90-A. This shows the time fuse inserted into a larger tube filled with granular BP. This tube extends to the center of the shell. The inner petal assembly is placed over the top of this. So you have an empty tube that was used to create the assembly which becomes filled by the tube and granular BP of the actual fuse assembly.

 

The tube from the inner petals is probably just cut short to save space and allow the petal to be centered a little easier.

Posted
Thanks a lot for clarification Mumbles.
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