shell patterns?

[MWJ]

Is there a chart or video on how to design different shell burst patterns? I'm only using small 1.75" shells for now but I would like to expand soon and would like to make patterns like a heart shape if it's possible.

 

Thanks

[pyrokid]

Patterns in shells as small as 1.75" are very difficult. Most guys prefer 4" and up for those purposes.

 

It's possible that you could make some rings in 1.75" but a heart would be a challenge.

[Zumber]

http://www.skylighter.com/fireworks/how-to-make/star-pattern-shell.asp

 

here is design of star pattern.

[MWJ]

Those are very nice, thanks. I didn't know you could do that!

[Mumbles]

That general technique will let you make most of the common 2D shapes. They'll be distorted some just based on how the physics of a shell burst work. You can see in the image from the skylighter article that the star looks more like a starfish. For a star, I imagine that using a shape with more blunted internal angles might work better. Something like this:

 

http://www.enchantedlearning.com/bwlines/star2.png

[schroedinger]

Have a look at F.A.S.T. and on the passfire tutorials and dissection reports. They show man different patterns and construction

[MWJ]

Thanks. I can see why a 1.75" would be soo hard to do. I would have to use 1/8" or less stars. So would a 3" shell be the min. size?

 

I thought doing a cross for our little church would be kind cool, but if its upside down it wouldn't be cool at all.

Edited February 17, 2014 by MWJ

[BrainDamage]

Thanks. I can see why a 1.75" would be soo hard to do. I would have to use 1/8" or less stars. So would a 3" shell be the min. size?

 

I thought doing a cross for our little church would be kind cool, but if its upside down it wouldn't be cool at all.

yea that might be hard to explain

[nater]

When firing pattern shells in a display, it is usually best to fire them in flights. This increases the chances that some will break with good orientation to your audience. This gets the point across and the ones that break off from the audience will be appreciated as you intended.

 

Rockets when dialed in perfectly are another good way to display pattern shells. By breaking the shell at apogee, you can control 2 of the 3 axis to ensure the best viewing angle.

[Wolverine]

I thought doing a cross for our little church would be kind cool, but if its upside down it wouldn't be cool at all.

I wonder if a length of ribbon (not nylon obviously) could be used to utilize drag to keep the right end down, much like the "foxtails" many of us had as kids.

 

Edit: nvm i see in the article that rope is used so yeah same idea, sorry.

Edited February 17, 2014 by Wolverine

[Mumbles]

Ribbons actually work better for this purpose since they have more drag. It can work fairly well for controlling the orientation in space, but you still have to deal with rotational freedom. Shapes that have rotational symmetry like rings, stars, cubes, simple geometric shapes, etc tend to come out the best for this reason.

[MWJ]

I have to get some larger shell and try some patterns. This sounds like even more fun then just stuffing stars into a casing. Even thought that's still a lot of fun too. This is the first year that i CAN wait until summer.

[nater]

You could always try rings and smiley faces with your small shells. Those patterns are available in consumer kits and rockets and don't end up looking too bad.

[MWJ]

Nater: That does sound fun to do.

[Zingy]

I recall reading an article, years ago, on a mostly minimal, or non-light emiting, timing mix referrred to as "Heat Train", for surprise or secondary patterns in star shells. I thought it was in "Pyrotechnica", but have been unable to locate the article. I somewhat recall lead nitrate, as the oxidizer. Has anyone here experimented with this 'Heat Train', a simular compound, or can direct me to any pertanint literature? Edited February 26, 2014 by Zingy

[bob]

I know of a few dark relay comps (which I believe is the same thing as what you are asking for). There is one in David Blessers book *Round Stars and Shells* below is a simple but very effective dark relay that xtrempyro (I think) shared with me.

Black powder 45 parts

Charcoal 50 parts

Dextrin 5 parts

Hope this helps.

bob

Edited February 26, 2014 by bob

[Mumbles]

There is another called Glusatz that is quite slow burning and emits very little light. It's used as a delay in a german form of firecracker most frequently, but I've often wondered about it's use in stars for a dark delay.

 

http://www.wichitabuggywhip.com/fireworks/glusatz.html

[Zingy]

Thank You, Bob and Mumbles. I apreciate the information, you provided.