Round shot crossettes

[mabuse00]

Since "real" cruciform crossette tools aren't easily available here in europe, I wonder what to expect from a tool like this here:
https://d2isyty7gbnm74.cloudfront.net/unsafe/646x646/square-production.s3.amazonaws.com/files/86a1ed12fe59e38fc58c9912e793d7e6/original.jpeg

Second rammer from the right, that's what I mean.

 

Most likely it will produce a mix of different fragment sizes - might still make a nice effect...?

Have you ever tried such a design?

Edited March 14, 2015 by mabuse00

[Arthur]

That will make a shatter comet -break into several pieces. the cruciform tool makes a star that breaks into four pieces. The effect is a bit different, but if that's the tools you can get then thats the stars you can make. Ask the usual makers whether they will send you a tool by post.

[nater]

Crosettes are traditionally made with round holes and hand rolled shots, similar to firecrackers to break them. Build them this way, dial them in and you will be fine.

[pyrokid]

Are there any videos of the mentioned shatter comets? I've only seen failed crossettes but if the effect exists I'd like to see it.

 

Is it possible and practical to attempt to make jetting stars using round shot crossette tooling?

[WonderBoy]

Here's an example at 23:55, traditional round cavity crossettes:

 

https://youtu.be/nA42JcTZ55Y?t=23m55s

 

 

WB

Edited March 15, 2015 by WonderBoy

[Mumbles]

I have used round shot crossette tooling before, but I have to say that the size of the shot hole on that tooling is gigantic! Normally they're between 30 and 40% of the diameter of the tooling. IE a 25mm tool should have a shot hole between 7.5 and 10mm. That said, once you get used to them, they're not hard to make right. As a slightly advantage, I find them somewhat less susceptible to cracking or being damaged when removing the tooling.

 

When you make them correctly, round shot crossettes will still typically break into 3-5 or 6 pieces. When in a shell with many other crossettes, they difference between exactly 4 and this is basically not noticeable. Even the cruciform cavity tooling tends to have some degree of fragmentation. It's only for single fire comets that I really strive for exactly 4. There is a rather labor intensive way to ensure that you get exactly 4 by pre-cutting the walls of the comet. Alternatively, using a quadrant pump in combination with a normal comet would work, though that is an additional piece of tooling you'd need to purchase.

 

If you want, I can send you or post the information I have saved on making the shots to break them, and the information on how to get them to break into exactly 4.

[mabuse00]

 

If you want, I can send you or post the information I have saved on making the shots to break them, and the information on how to get them to break into exactly 4.

Please do

 

Is it really necessary to do these "hand rolled shots"?

 

 

I wonder if an uncontrolled fragmentation wont lead to a lot of unlit pieces?

I dont mean blown out ones, but since the crossette can only take fire from the uncovered an primed ignition side - what happens if the lines of breakage dont go from the ignition side to the bottom but rather around the crossette?

(Do you understand what I mean?)

 

 

Another question:

What is in your opinion the smallest practical size do cruciform or round shot crossettes? I figure the breakcharge issue will be less problematic in larger sizes?

 

I prefer 4" or smaller headers/shells, so I'd like to stay under 1".

[nater]

The hand rolled shots increase confinement. A friend found they were necessary with his techniques using a dark report mix to get uniform breaks, crisp timing and no jetting. I apologize that I cannot comment from first hand knowledge as I am just now making my first crosette comets as well.

[MrW]

For breaking my limited number of x-ette (crucifix shape) I use granulated whistle mix. Gives a crisp break and not noticable flash. However I have only made a few dozen using wolters tooling.

[pyrokid]

What formulas are you guys using? I just put together a little round shot crossette tool and I need to make some comets.

 

This is the best time of year

[Livingston]

Any glitter or charcoal base formula will work great for crossettes.

[Mumbles]

Oops. forgot about the offer for info. The below information is from John Reilly, whom is a talented traditional fireworker. I'd try out both his method and the method in fulcanelli to see what you like best. I'll see if I can find the stuff on the breaking into exactly 4 pieces. Basically you paste the comet, use a hacksaw to cut the cavity into 4 pieces, and then finish as normal with a shot.

 

 

Retrieved from rec.pyro on 1/4/10. Originally posted on 6/6/06 by John Reilly

 

http://groups.google.com/group/rec.pyrotechnics/browse_thread/thread/ad1938a90753687a/70aab6618a1aa20b?hl=en&ie=UTF-8&q=John+Reilly+rolled+shots#70aab6618a1aa20b

 

The method described in Fulcanelli part II is the traditional Italian
method and is the best in my opinion. The stringing of the hole shots
as described is an art. The dried shots are cut apart and the string
ears overlap the cavity end of the crossette star and are held in plase
by the pasted paper crown when finishing the loaded star. The string
keeps the shot from falling through the burned open cavity as the comet
is spinning through the air. I cheat a little and use 3" gummed paper
tape to roll the shots using a 4 point crimp to close one end before
punching and fusing.
For the 1-1/4" comet shots I take a 5/16" diameter piece of wooden
dowel (mandrel) which is about 4 to 5" long and waxed by rubbing with a
candle stub to avoid the paper's sticking to it. One end of this
mandrel is bored dead center with an 1/8" hole about 3/8" deep. The 3"
gummed kraft paper tape (std. 60# weight) is cut into 3" lengths to
give three turns around the mandrel. (One 3" strip gives 5 finished
"hole shots". A piece of this paper is placed gum side up with the
mandrel squared and centered on the edge nearest you. With thumbs and
forefingers the first turn of paper is laid on the mandrel and held
tightly against the rolling board with the fingers of the left hand (if
you're right handed) grabbing the damped sponge and wiping the
remaining pasted side of paper to activate the glue. The thin casing
is formed with a push of the palm of the hand and rolled firmly back
and forth the round and tighten the 3" long tube. The damp tube is
slipped up about 1/8" to 3/16" past the drilled end and with athin
awl, a 4 point crimp is started on the overlapping paper. (12:00, 3:00,
6:00 and 9:00 o'clock positions. The mandrel with the overlap crimp
end is smashed smartly down on the rolling table which folds the 4
point crimp down on the end of the mandrel. While the mandrel (crimped
tube end) is held tightly against the table the mallet is taken and the
mandrel is give two or three quick raps to "set" the crimp closed. The
awl is taken and a hole punched in the center of the crimp to allow for
the insertion of the fuse later.
The case is slipped up on the mandrel again and with sharp scissors is
snipped off (into a small box) so you have a shot tube with one end
open , one end crimped closed and with a fuse hole in the center of the
crimp. This is repeated 4 more times and the another 3" paper strip is
rolled and so on till you have 100 "shots" or however many you need.
This sounds like it is time consuming but I could have rolled ten shots
in the time it took me to type this.
I use either specially made thin fast match or chinese firecracker
(tissue) fuse which is cut ahead of time into 3/4" lengths: the fuse is
inserted through the hole in the crimp of the shot leaving about 1/4"
projecting outside the crimped end. The shots are all fused first and
then loaded. A number of 1-1/4" pcs of thin cotton or flax string are
cut (one per shot). First, a shot is taken and a piece of the cut
string dropped into the open end of the shot tube with the tag end
hanging out.
A scoop of dark report comp. (50/50 mix of KClO3 and Antimony Sulfide)
is added to the open end of the shot. A pinch of fairly coarse sawdust
is added on top lightly pressing in with the forefinger (string still
hanging out.) Lastly a good smear of white glue (PVA) is run across
the sawdust (keeping the string end out of the way). Set them aside to
dry. When the shots are loaded into the star cavity the string lays
across the comet end. The comets get a 1-1/4" very thin chipboard disc
on the end (holding the string) before the kraft pastewrap is pleated
down over the shot end. (The chipboard disc helps keep the paste from
soaking into the star). There are many method and tricks to cracking
crossettes and this is just one way I find convenient and workable for
me. There is no "correct" technique except the one you find reliable
and feel comfortable with. Flash powder (70/30 KClO4 to blackhead or
similar fine flake aluminum) will work fine with these shots too. I
only use the black antimony and chlorate to avoid the bright flash'

John

 

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From 6/13/06, same source and acquisition date

 

Hi Tes. When I "star crimp" small tubes like these, I simply use the
pointed 1/2" or so of an awl or ice pick. I've made little awls by
taking the sharp ended pivot pin from a cheap metal compass and turning
a little wooden handle on a mini lathe. Drill a hole in the handle use
good 2 part epoxy cement to secure it. I use the same awl to crimp the
tubes and ream the hole for the fuse in crossette shots (don't have to
switch hands or tools). This is how I've made 1/4" or 5/16" bore
bottle rockets since the mid 60s as well. I posted the method 6 months
or so ago on how to make those with strips of gummed kraft tape. The
"core" is formed by simply twisting and pushing the awl point about a
half or 5/8" through the center of the star crimp and into the rammed
fuel core. Quick and easy and they work great with "chrysanthemum 6"
fuel. If the hole shots were a bit larger in diameter, I could use a
.410 shotshell crimp starter die but it's so quick with the 4 point
"crimp and slam" technique that I don't worry about it.

John