Crossette Stars

[Tweetybird88]

I really love the effects from these kinds of stars and I was wondering how to make them and how to use them in a shell.

 

Does this same process apply to comets?

[ewest]

Does this same process apply to comets?

Yes it does. You can buy crossette pumps in sizes from as small as 3/8" up to 2 1/2".

 

And BTW, someone correct me if I'm wrong but stars and comets are exactly the same thing, it's just that for sizes of 1" and below they are called stars and anything over 1" is called a comet.

[Mumbles]

A star and comet can be used interchangibly in most cases. Theres not really a cutoff. I would call my 3/4" pumped stars comets. How I think of it is if I pump it, it's a comet. So I could pump some 3/4" comets, but if I had a 3/4" starplate I'd call them stars. Same exact product. You could have round comets too, but those are more rare.

 

I make my crossettes slightly different than frozen, but it all works out. The key is the tooling, which you generally have to purchase. I suggest Wouter Pyro tool. wwww.wouterpyrotool.com Skylighter also carries them at about the same price. For the $3 more from Wouter, I greatly suggest them. They are much higher quality. He uses hardened steel that is NiTuff coated. It lubricates the crossettes, and protects from scratches. The Brass from skylighter is shit. I got 1 comet pump from them and never again. It is all scratched up and siezes up now from the scratching or slight identations on the bottom of the sleeve from ramming. I also have a 3/4" crossette pump from wolter, and it is beautiful, and will last near a lifetime.

 

Anyway back to the crossettes themselves. I usually use an arbor press. I don't personally have one, but I have access to one through a friend. A vice is also acceptable. Ramming would work too, but perhaps not as consistantly. I have also been told by several sources that they increase the amount of binder they use in their crossettes, and it really helps with the breaking. They go from 4-5% dextrin up to 7% dextrin, or SGRS. After your comp is properly wet(6-7% water), granulate it through a window screen. This just makes it easier to work with, and not absolutely neccesary. You did ask how we did it through.

 

Press your crossette pump into the composition a few times, pressing down on the rammer to compact it in. Go until the pin is about 1" or so above the top of the sleeve. Line up the pin with the groove in the pump. Press/ram as you please. For a normal crossette I place a thin piece of metal, or popcicle stick or something relatively thin across the groove in the pump. I eject the rammer down until it touches the popcicle stick. I shave off all the excess comp sticking out. I then remove the stick and flip the pump upside down. I grasp the body of the sleeve and press it down to eject the comet. I carefully pull the rammer back and lif the crossette from the top of the pump.

 

For the burst I have been using 70-30 standard flash, and fill the cavity. I had been using thermalite as a passfire, similar to how frozen uses fast visco, but I need to find an alternative. I am back at the experimental stage. I may move to dark flash and get everything dialed in with that. Everything else I do is very similar if not the same as frozen with the end disks and tape. He didn't really go into much depth as far as the actual pressing of the crossettes, so I thought I would. Frozentech has an excellent article there, and from the video, you can see the results.

[Ventsi]

I'm going to bump the hell out of this one.

 

I recently made a very nice 3/4" cavity pump with a removable pin. I really cant understand why the pin is needed though, if the cavity left by it is left empty and flash is poured directly on top, would it serve as a passfire hole to the chamber which holds the burst/flash? Thus cresting more confinement and a better break? I don't understand why people use fuse to put in the cavity either , I'm not trying to diss but I just don't get it.

And as far as rolled shots go, would it be possible to use some fast visco leading into the shot to set it off? Though they concern me as that they will not light the inside of the star cavity the same way flash contacting the star would.

 

Anyone understand what I'm saying? If so help me!

[Arthur]

In a simple croisette the pin on the tool makes the passfire and rise timer when the criosette burns through to the pin hole then the flash takes fire and the croisette breaks into four.

The depth of comp over the pinhole governs the rise before the break, the internal depth of the pinhole governs how much star there is left to break into the quarters.

 

Ususlly a croisette has a card disc and is pasted with paper on the sides. Extreme croisettes have either a puck of their own material or another croisette glued over the opening, that can break eight ways and holds a lot of flash! OR you can use a shallower croisette tool.

[Mumbles]

The pin acts as a passfire into the cavity containing the bursting charge. This is more important for shotless crossettes than with shots. You need some sort of containment for the charge to shatter the top, otherwise it's jets.

 

Think of flash like black powder. What happens when black powder gets compressed, and there are no more air gaps for fire to pass? It burns slowly, like a rocket of course. This same thing can happens with flash. It might not happen for every crossette, but your timing will be poor and there might be a several second gap between the first and last break.

 

This last thing is why fuse is placed in the tube. It prevents flash from getting packed in there, and transfers fire almost instantly to the burst cavity. It also sprays a bunch of fire, ensuring everything lights at once, much in the same reasoning behind packing a spolette with blackmatch on the transfer side, or crossmatching both the interior and exterior. A lot of people like thermalite, but that is getting harder and harder to get. I have gotten them to work with thin blackmatch from 5 strand quickmatch. There are thermalite substitutes, but they are slightly intimidating to make.

 

As far as fast visco, look at Frozentech's blog.

http://www.amateurpyro.com/forums/index.php?autocom=blog&blogid=3&

 

His posts will have some good info there if you search for them. Don't worry about the sides not igniting, they will. Even if they don't the bottom of the fragments will be burning anyway.

[Ventsi]

Quick question:

 

I have 3/4" "crossettes", I need to break them, I have:

 

Kperch

 

Bright Al, 12micron

-325 Sponge Ti

Sulfur

 

I suppose I could go and get a bar of Mg, and extract some material from that, but I'd much rather not.

 

My cavity is about 3/8 deep, 1/4" wide, no cross just a tapered hole.

What is the hottest mix I can come up with?

 

I was thinking some thing along the lines of:

 

KP-68

Ti--27

Al--5

S--5

 

the Al would be there to simply fluff things up FYI.

 

Any invoice here is greatly appreciated.

 

Picture of the *Crossettes* using Win 25.5

http://pyrobin.com/files/p1080200.jpg

[Mumbles]

Good luck. I had trouble with my crossettes even using straight 70/30 with thermalite. You don't mention if you have it, but many have had success with granulated whistle mix as a break. Personally, I use dark flash on shells this small.

[Bonny]

Any invoice here is greatly appreciated.

 

I'll invoice you shortly... I accept paypal and money orders...

[Aquarius]

I'm wondering if I should make myself a crossette-tool. The thing is, I can't find anything suitable to make the"x" with. I see form the previous post that a cylindrical cavity is used. Is it worth trying, or should I just order one premade right away? I know it won't break into four pieces, but can it still work? I was thinging MgAl-flash for the break.

[Mumbles]

Many people swear by cylindrical cavities. I think they almost all use rolled shots though. There is an excellent writeup on rolled shots on rec.pyro by John Riley if you are interested. Frozentech has a blog entry on it here too.

 

Ventsi, where'd you get that tooling? The passfire pin looks awefully big.

 

If you are set on the X shape, a square works just as well. Just taper a piece of square rod stock.

[Ventsi]

I made it myself for the heck of it. If I was really into crossettes I'd get some tooling from Wolter. Perhaps I'll make some thermalite or substitute it with some black match, I'll make a few rolled shots today and see how they go.

 

And no, unfortunately I don't have whistle. I'll try some the Ti flash though.

If you guys want, I could post a few diagrams and specs of my tooling.

[Mumbles]

You might want to show that they work before trying to pass off diagrams and specs. Mike Swisher posted a quote by Thomas Kentish today on passfire you might want to take to heart. Kentish was talking about another author:

 

"The greater portion of it is absurd and impracticable, and shows that it was written by a person who undertook to teach what he had not learnt."

 

I think you got lucky you have (presumably) silver streamer stars. That Ti flash is going to BRIGHT. It'd be very distracting in any other composition.

 

For reference, because it seems you just winged it, here are dimensions from someone in the industry:

 

From Jeff Doty on passfire 10/2/2006

 

For my 3/4'' pumps with a cylindrical cavity:

 

Length of Cavity: 15mm

Diameter of Cavity: 9mm tapering to 7mm

Length of timing pin: 6mm

Diameter of timing pin: 2mm

Distance from tip of pin to bottom of crossette (ie. burn distance to flash): 10mm

[Ventsi]

I was mainly going to post the specs. to see what I did wrong with it, not for others to copy

 

It seems I got pretty close to your tooling.

 

Length of Cavity: 12mm

Diameter of Cavity: 9.5mm tapering to 7.5mm

Length of timing pin: 3.5mm

Diameter of timing pin: 3mm

Distance from tip of pin to bottom of crossette (ie. burn distance to flash): 6mm

 

I should have pumped them longer. Oh well, I am using silver streamers, and still debating if I should do rolled shots, I just tried 3 and the one I actually closed up well left me deaf, and destroyed the styro-cup it was on. I'll keep testing them and if I settle on a method I'll post a video of it. And don't worry, I only wanted to give these inserts a shot, if I actually started making them I would make sure I had everything to do so.

Edited December 16, 2009 by Ventsi

[Ventsi]

Okay, here are the results, and my process for making rolled shots.

 

These were made per combined instruction of Lloyd S,, John R. and Frozentech.

 

I started with a tube rolled about 1/32" thick around a 3/16" aluminum dowel. Then cut into 10mm pieces

http://i102.photobucket.com/albums/m100/asota_2006/P1080220.jpg

http://i102.photobucket.com/albums/m100/asota_2006/P1080222.jpg

 

3mm was folded over and crimped in a 6star pattern, then flattened out by pushing the tube on a flat surface:

http://i102.photobucket.com/albums/m100/asota_2006/P1080226.jpg

 

A small piece of black match was cut, roughly 6mm long, then wrapped in paper tape making sure the first layer is a bit loose so the BM can" quickmatch" into the shot.

 

http://i102.photobucket.com/albums/m100/asota_2006/P1080227.jpg

http://i102.photobucket.com/albums/m100/asota_2006/P1080231.jpg

http://i102.photobucket.com/albums/m100/asota_2006/P1080232.jpg

 

I then filled the inside with the break powder, only going about half way, so when the fuse is inserted it wouldn't pack the powder down at all.

 

http://i102.photobucket.com/albums/m100/asota_2006/P1080234.jpg

http://i102.photobucket.com/albums/m100/asota_2006/P1080238.jpg

 

Then a very small amount of wood glue was put around the circumference of the tape wrapping the blackmatch, the fuse was a snug fit inside the tube.

http://i102.photobucket.com/albums/m100/asota_2006/P1080239.jpg

http://i102.photobucket.com/albums/m100/asota_2006/P1080240.jpg

 

Here is the final result, these pack quite a punch, which I suppose could easily be adjusted to be weaker or stronger.

 

Again, this is by no means a tutorial, just me showing my method open for criticism.

Edited December 17, 2009 by Ventsi