1" insert cups

[Swede]

A while back, these puppies were on sale and I couldn't resist... I bought about 300. I have always been into so-called "miniature fireworks" because I think the concept is interesting, i.e. working towards a bonsai concept, getting good performance in tiny packages. Stealthy, inexpensive, can they can be passed off as consumer works.

 

I know these things are typically used as inserts in larger shells. Basically, I'd love to hear suggestions for interesting things I could do with them. When cupped together, they are slightly larger than 1". With reinforcing fiberglass or gummed tape, the diameter will allow easy insert into a 1" tube.

 

The obvious answer is miniature cannister-type shells, probably using slow/dirty flash as a break. A small salute would be simple, but I'm more interested in miniscule stars, probably pumped 1/8".

 

I think the trick with these things is a low (but still safe) burst height, and a burst not too strong, but still effective, with the idea being charcoal streamers or glitter will arc in their descent, and not fly outward at supersonic speeds, or break up. Anyone mess with these cups in unusual ways?

 

http://www.5bears.com/firew/tcups01.jpg

 

http://www.5bears.com/firew/tcups02.jpg

 

http://www.5bears.com/firew/tcups03.jpg

[Pretty green flame]

Check out Lady Kate's tutorial on Mouse turd stars . They'd probably be the best choice for these small shells, apart from a salute ofcourse. And with such a small device you're probably better off with using some strong flash composition, because of the realitvely small ammount of it that is used.

 

Your probably won't even need to paste or spike these things, glue them with PVA, let them dry and you're ready to fire. Other than a single shots small mortar, pack a lot of them with flash and send them up in a larger canister shell, break the shell softly with a relatively small BP charge and enjoy the barrage

Edited May 20, 2009 by Pretty green flame

[psyco_1322]

Me and my brother used to take stars from consumer shell stars and fill those little green crackling balls full of them( after removing the dragon eggs). You could only get about 8-10 in there, dump in a bit of whistle, and tape up with some fiberglass tape. Fused with visco we would just take them outside, light and throw in the air. Performance was fine, and even at a thrown height, the stars were long burnt out before they close to the ground. Edited May 20, 2009 by psyco_1322

[Ventsi]

I bought a bunch of these a while back.

 

Here is a vid of a "safe" salute using them:

 

 

Yeah pasting/taping isnt needed at all just some good wood glue to seal the two halves firmlu is all you need.I use the Mouse Turds method with these and stick 'em insde starmines, awsome effect!

[Swede]

Cool. I like the concept of a salute barrage from a 4" or so. I did crank out some miniscule zinc stars (the first time I've tried Zn) and we'll see how it goes. The wall thickness in this small volume creates a good case without further pasting or taping.

 

The ZN stars didn't pump for shit... I couldn't seem to load the tube very well. It didn't work like larger diameter tubes. I ended up cutting a bunch, but they were too wet. I'll figure something out. I keep thinking a boatload of tiny dragon eggs (without further coating) would be a cool effect.

 

I agree, in retrospect plain old 70:30 FP will be needed for reliable break, with good prime on the tiny stars.

[Swede]

LK's site has a PDF file on BP that I had never seen before. It is a really good read, and may interest people:

Modern analysis of BP

 

Interestingly, they discuss substitutes for charcoal which is 98% of the variation in terms of the chemical performance of identically-prepared BP batches.

 

Another edit: "Jet milling?" WTF is that? Apparently there is a method of BP manufacture that is not based upon the traditional mill wheel. Cool stuff.

Edited May 21, 2009 by Swede

[Mumbles]

My understanding is that a jet mill is kind of like a giant air powered centrifuge/sandblaster working in reverse (taking the small stuff out of the middle, and leaving the big stuff on the side to be pulverized more by impacts with itself.

 

http://www.jetpul.com/mequip/milloper.htm

[Swede]

I tried the Mouse Turds method of making tiny stars - whipped up a stiff dough of #8 chrysanthemum, flattened it into a patty about 0.157" thick, then laid that on a #5 screen, which is also 0.157. Hammered it through with a rubber mallet.

 

Results - mostly positive. Quite a few of the stars clumped, which could be prevented a bit by making a stiffer dough. But as they partially dry, these clumps are breaking along the original cleave lines pretty easily. The only other drawback is that there is a significant amount of tiny pieces that are probably best screened from the batch and recycled or discarded; maybe 5 to 10% of the total. I do like the method. Pumping stars this small is phenominally tedious.

[psyco_1322]

My bet is those stars make a nice little cloud of orange dust. Those stars are going to burn up sooo quick, in the break most likely. In case they don't, get a video and make me look like an idiot

 

I would just roll out a paddy and cut them. You might try using some tiger tail, since it burns a bit slower and also produces a denser tail. That might help pronounce the effect.

 

Some strobe comp granulated through that screen might make some nice shells that small.

[Swede]

We'll find out! The SGRS was an impressive binder; it was the first time I've tried it. They are hard little buggers. If they poof into a glowing orange cloud, that'd be OK for such a tiny shell. Maybe it'll be its own unique sort of effect.

 

I did screen out the smaller pieces, so I've got a fairly consistent size. I earlier tried cutting them, but the tiny size makes it more of a challenge, and the pieces tended to distort, probably because I'd wetted it too much.

 

I'd like to try the so-called "egg-crate" stars, where you take one of those fluorescent light fixture panels that have the small squares formed in them, then press a section of the panel onto a rolled patty. Tap it down with a rubber mallet, then let it dry in place for a day or two. Once they harden a bit, supposedly you can poke or shake them right out, as they contract slightly.

[psyco_1322]

I have looked for some of those lighting covers, and I can find them fine at local stores easy. The only problem is that they are not 1/2" square, all of them I have seen are 1/2" x 1/2" x ~3/8". I don't really want 1/2" stars that are only 3/8" thick.

[Swede]

What if your star dough was rtolled to 1/2" thick? When you pressed the egg crate section, you'd end up with 1/8" of the star dough poking above the level of the crate. If the dough is stiff, it should retain its shape fairly well, and you'd end up with correct 1/2" stars.

 

Just a thought. I've never tried those egg-crate fixtures, but it seems like a sound concept. And they are cheap.

 

For those who don't know, it's this:

 

http://www.capitolplastics.com/product%20_image/plas_para_louv2/Egg%20Crate%202008.jpg

 

I don't know why it's called egg crate, but that's the name for it.

Edited May 25, 2009 by Swede

[FrankRizzo]

I have looked for some of those lighting covers, and I can find them fine at local stores easy. The only problem is that they are not 1/2" square, all of them I have seen are 1/2" x 1/2" x ~3/8". I don't really want 1/2" stars that are only 3/8" thick.

 

 

Stars don't have to be perfect cubes to work.

 

 

Swede,

 

Just an FYI, but I looked a few different types at the local hardware store, and each "cell" has a slight internal relief taper to facilitate easy removal from the mold. I was thinking that stacking two on top of each other would be a good way to increase the depth...the taper ruins that possibility.

[Mumbles]

Well, you could them as a large starplate. The taper wont be a problem as the stars are extruded wet. It shouldn't be too hard to make a 10x10 plate from wooden square dowels I would imagine.

[Yankie]

Here is a thread on the light diffuser method: http://www.apcforum.net/forums/index.php?s...=light+diffuser

I managed to find some 1/2" square stuff, stars are a bit hard to get out as it wasnt tapered.

I am going to try master star rolling now as the other methods have drawbacks (time consuming and ugly(cut stars))

[Swede]

One unexplored area of star creation is extrusion under power. It would take quite a setup, probably expensive to boot, but picture a cylinder about 1" to 2" ID, with a piston. Attached to the piston is either a hydraulic pack, or easier/cheaper, an ACME threaded rod + nut. At the nose is a replaceable die hole. Install the die you want, then spin a handle or energize the hydraulics, and the star dough is forced out under pressure. You get consolidation and shaping in one step. When the cylindrical star is long enough, a swipe with a knife will drop the star into a collection screen, layered with prime if necessary.

 

The entire thing could be automated. The nose of the extruded star trips an electric eye, and a stepper motor swings a blade through the star to separate it.

 

It's definitely a fantasy device, but a dedicated amateur could make one, I'm sure.

[Pretty green flame]

Swede, If you want mass production think in the direction of a pharmaceutical pill press, I don't know the english name but i saw these things in action, 800.000 pills in an 8 hour shift. Let it run for a day and you're set for life

This would be pretty much better than extrusion, and you could either use no water or a fraction of it compared to extruding it.

[FrankRizzo]

Tabletting presses are used in modern fireworks mfg for things like "snake" pellets. Edited May 28, 2009 by FrankRizzo

[Swede]

Haha, that would be cool. I wonder if those things could be rigged to press giant "tablets" suitable for larger shells.

 

I found a 1/2" X 1/2" egg crate in the neighbor's trash, and grabbed it. I'll give the egg-crate method a shot. Maybe dusting it with graphite might help with the release.

[Mumbles]

They come big enough to make up to 50mm comets from personal experience. Once you have the rotary press, you'd justs need a new set of dies made. Ideally you'd want a deepthroat press. It was a type that allows for deeper dies, and thus more normal sized cylinders.

[Bonny]

I found a 1/2" X 1/2" egg crate in the neighbor's trash, and grabbed it. I'll give the egg-crate method a shot. Maybe dusting it with graphite might help with the release.

 

 

I've used the "egg crate"/ light diffuser many times and it works well. Some stars after drying fall right out on their own due to the taper and star shrinkage. The only ones I had problems with were perc colour stars that were overwetted. Quite a few broke when extracting but it wasn't too bad. I pack the comp in with a rolling pin, scrape flush with a blade, then indivuidually press each square around the outsides of the frame as they never seem full enough. You can also turn the diffuser over and jam more comp in from the other side where needed, just watch the stars don't fall out.

[d4j0n]

I updated my tutorial on the member tutorial's page on 1" aerial can shells. That is almost exclusively what I use these for.

[Swede]

I updated my tutorial on the member tutorial's page on 1" aerial can shells. That is almost exclusively what I use these for.

 

I saw it and it's a great tutorial. My daughter and I have been having a lot of fun making these little shells. The only thing we're having trouble with is the gluing of the two halves together in such a way as to make the OD small enough for a 1" HDPE mortar. What we've been doing with some success is to install a cable tie around the widest portion, and cinch it right down.

 

The only other thing we did differently was to use white glue rather than hot glue to secure the burst tubes over the time fuse. We found by dipping the burst tube end into a puddle of elmer's glue, it installed with ease, and was a bit less messy than hot glue. Also, in rolling the burst tubes, we used a section of teflon round rod rather than a battery, which works great because the glue simply will not stick to the teflon. Otherwise, we're following the directions closely; the shells look good.

 

Thanks for updating it, we're having a good time making these.

[psyco_1322]

Swede,

How did those C-8 stars come out in your little shells?

[Swede]

Swede,

How did those C-8 stars come out in your little shells?

 

If you refer to the "mouse turds" stars, they seem a bit fragile to me. If I were to do it again, I'd up the binder % a bit, but it was probably my technique more than anything else.

 

In the end, I took the whole batch of C-8 turd stars and screened off the dust, which was a pretty fair amount. The manipulation of the screen broke any of the fragile remnants, which then also went through the screen. What was left was a decent bag full of stronger small stars.

 

I haven't had a chance to launch any yet, so I don't know how they will perform - sorry. I get the feeling they are going to POOF into an orange cloud. We'll see.

 

I REALLY can't get the extrusion thing out of my mind. If we have WASP machines, I don't see why we couldn't have a CNC extruder. All you need are three or five dies, a stepper motor and a blade, and a computer to run the show. Heck, you don't even need a computer, just an adjustable electric eye, a DC gearmotor, and a blade. As the star extrudes, it trips the eye, turning on the gearmotor. Blade cuts the star right at the die mouth, electric eye opens back up, motor stops.

Edited June 29, 2009 by Swede