Aerial Shells

[FREAKYDUTCHMEN]

Ah ok, pepper seeds are quite big indeed.

 

It explains a lot when your shell fits tight in your mortar

 

I shot a cannister yesterday and I had lot of space left between the shell and the mortar. Nevertheless a great lift, with the one ounce per pound rule 2FA.

[Mumbles]

I must admit, I thought that the TT to D1 was kind of an odd choice for effect changing stars, but it seemed to work out very nicely. It almost looks as if the charcoal fades away to reveal the glittering in the video

[hashashan]

Hi,

I have aquestion that might look stupid.

How long should be a time fuse on a 7" shell?

 

for my 3" i use 2.8 seconds, and the 4" i use 3.7 seconds

 

Is 6 seconds ok?

[Brakkie]

@Hashashan:

Although I do not have any practical advice for you, I do have a link with a table for the delay times. Hope this helps with confirming that you were, more or less, right on the money!

 

Time Fuse Delay Times:

Shell Size (in)................ Delay Time (sec)

3"................................ 3.0   

4"................................ 3.5

5"................................ 4.0

6"................................ 5.0

8"................................ 6.0

10".............................. 6.5

12".............................. 7

Typical delay times from lift until burst for aerial shells.

 

Ofcoarse there are variables for this table and your 7" seems to be missing here. One of the most important variables is the ammount of lift you use. If you're a fan of lifting them hard then maybe you could cut down a little bit. But I think you should be pretty much right on the money with 6 seconds.

 

You can also see that your 3" and 4" are right about perfect as in time delay wise.

 

 

I hope this is of any help.

[nath0r]

Well i've just completed another 4" shell, hopefully get to fire it thursday night depending on the weather. It's my first attempt at using Ruby Red stars in a shell so im hoping they will all light without any problems. I'll try and get it on video if possible, below is a pre fire pic.

 

Shell weight is around 470g

 

Lift is 47g of BP

 

If i remember corectly there are 200g of Ruby Red stars in the shell give or take the few i had left over.

 

Break is BP on grass seed with 5g of flash (70:30) Perc/Al

 

http://www.apcforum.net/files/IMGP0287.JPG

[Mumbles]

I see the rising comet, but what is that in front of the comet? It kind of looks like the comet is starting to grow a pretty thick moustache.

[WarezWally]

Looks like some sort of fuse (flying fish?) covered with BP

[nath0r]

Haha it actually does. After i attatched the rising comet i stumbled over some fairly old cut stars i had left over so i decided to put a few of them on the shell aswell for good measure. They probably wont add much to the rising effect as they're quite small but i didnt fancy making another mine to use them up.

[psyco_1322]

lol @ the rising tail growth. Looks good.

 

 

Hay a question on paper hemis. I got some 3" ones and made a shell but they seem to really be a bit small. Anyone else experience this? Plastics are a bit bigger but the paper ones would require a ton of pasting to fill up the gap.

[BPinthemorning]

I've realized I have quite a few commercial areal shell tubes, and I want to make some shells to fit them. What size should I buy? Thanks!

[nath0r]

Hay a question on paper hemis. I got some 3" ones and made a shell but they seem to really be a bit small. Anyone else experience this? Plastics are a bit bigger but the paper ones would require a ton of pasting to fill up the gap.

Well how big a gap are we talking about? all shell hemis are made slightly smaller than the size specified to allow for pasting and fusing. Obviously this gap isn't huge, so if your 3" shells look more like 2" shells then something is wrong. Could you maybee post a picture of the shell?

 

 

I've realized I have quite a few commercial areal shell tubes, and I want to make some shells to fit them. What size should I buy? Thanks!

Well you need to firstly find out what the ID of the tube is, that will then tell you what size hemis to buy/make.

[BPinthemorning]

1-15/16" inches is what I got I think. Id of the tube that is.

[psyco_1322]

Well BP thats about a 2in tube, so if you'd like easter eggs shoot great out of them. They have some of the paper ones that are 1 3/4" and dont work with them.

 

Here is a prefire pic or one, sorry not pics of it and gun.

http://i108.photobucket.com/albums/n3/psyc...22/S4024055.jpg

 

Here is the video, yes thats all the farther it went.

http://s108.photobucket.com/albums/n3/psyc...nt=S4024060.flv

 

Please do not try and state the my lift is weak, or maybe I didnt put enough in there or blah blah blah. I shot the shell as I made it in a normal 3" gun. It was pasted using the 3 strip method, 3 layers, fiberglass re-enforced gummed craft. It had about a 3/8" gap I would say from memory.

[TheSidewinder]

If that's a Class C tube, remember that they can be ALL over the place with respect to ID.

 

An ID of 1-7/8" is the most common "2-inch tube" for Class C, but I've seen variations which are considerably more than 1/32".

 

How accurate was your measurement, BP? 1/32" is easy to miss.

 

Excalibur tubes are a bit larger than normal, as are Goliath I think. Oddly enough, the generic and Black Cat 6-packs I've bought have been the most consistent at 1-7/8".

 

And there's one brand labelled generically as "Festival Balls" that barely over 1-3/4". If you try to use any shell other than what the tube came with, you'll regret it.

 

You'll likely have to adjust your pasted layers carefully, to get a correct fit.

[Mumbles]

I wonder if you got 2 1/2" paper hemispheres by mistake. Normal paper hemispheres should be around 2 5/8" OD before pasting. The break looked good, so I wouldn't say it's just a matter of lack of pasting.

 

I have noticed that when using plastic 3" shells, I need more BP though. They are exactly 2 5/8" OD, and seem kinda small for the mortars. With the quickmatch and such it normally fills up adequately though.

[justanotherpyro]

Just thought I would toss these up. A comparison between a 4" plastic and paper hemi. The paper one actually fits inside of the plastic hemi.

http://i42.photobucket.com/albums/e301/justanotherpyro/IMG_0703.jpg

 

http://i42.photobucket.com/albums/e301/justanotherpyro/IMG_0704.jpg

 

The festival ball shells are significantly smaller than the TNT ones that they sell in the shacks around here for July 4t. I have an excalibur 2" mortar that works great for easter egg shells.

[Mumbles]

That picture reminds me of an idea I had a few weeks ago. I was wondering if you make a nesting set type of things with paper and plastic. Maybe paste one or two layers on the paper shell, enough to make in snug into the plastic, and then gluing the plastic shell over the paper. The time fuse would probably have to come out the gap in the paper hemis to fit and orient correctly.

 

I hear reports of people having to use only one or even no paste layers with nesting sets. I had a mixture of paper and plastic hemis in a bag, and I saw one snug inside the plastic hemi and got the idea.

 

There is a slight lip inside some plastic hemis around the time fuse that may need to be filed off to fit correctly.

[TheSidewinder]

Now there's an intriguing idea.

 

Sure beats hell out of having to paste layer after layer of Kraft. The cost savings in Kraft wouldn't cover the cost of the outer hemi, though it might cover the cost in aggravation from pasting.

[Pretty green flame]

Sidewinder, pasting shells is half the fun

Anyway, I don't see the point of encasing a paper shell in a plastic one, might as well fill the plastic one and be done with it.

[BPinthemorning]

Well I have found that easter eggs fit perfectly, so I'll stick to that.

[TheSidewinder]

Sidewinder, pasting shells is half the fun

*snip*

Opinions vary.

 

So far, I've cheated and used cardboard cans which really haven't required much additional pasting in.

 

That said, I DO add two layers of Kraft to the casing, each one at right angle grain to the other, before spiking.

 

This year promises to be a complete bust for shell-building, unfortunately, due to finances and a job-hunt (as well as gas prices, ouch), so I won't be putting to use the 6" ball hemis I snagged at the PGI in '06. There's always next year.

[ST1DinOH]

question to all you guys who have made double petal shells...

 

if i were to use a 3 inch plastic hemi, inside a 6 inch plastic hemi, would the (un taped/reinforced but sealed with xylene) shell be thin enough to still function properly or am i better off making my own inner petal out of a few layers of newspaper.

 

i was thumbing through blessers book and it sounded to me like the kkey to getting a double petal to do it's thing was that inner petal needed to be thin/weak and fragment eaisly to allow passfire to the outer petal of stars.

 

thing is i've got all these plastic 3's and constructing a hemi from scratch seems like a waste of time if it's do-able with the plastic ones i have.

 

whiel we are discussing double petals...

 

is it possible to make a true atom break with a tripple ring outter petal and an inner petal/pistil of densly packed glitter?

 

if so is it then possible to use one star per ring that is larger than the stars which comprise the ring (of a contrasting color) and still have the larger stars stay on plane with the ring they originate from...

 

in other words i'd like the inner petal to be the nucleus of protons and nutrons, the single large stars per ring to indicate the electrons, and the smaller stars per ring to indicate the path of the electrons.

 

http://www.mondotees.com/ProductImages/bangonicons/atom.jpg

 

my fear is that everything would be fine except the larger stars onthe outter rings. it almost seems as if the larger stars would have a different reaction to the break forces than the smaller stars which make up the rings.

 

because the stars are all originating from the same point in the shell i was thinking of off setting the larger stars to be a bit closer to the center of the shell by using a thicker than average glob of hot glue or utilizing some small paper rings to give the stars a slight setback from the inner wall of the outer petal hemi.

 

anyone have any opinions on the behaviour of mixed sized stars in a ring shell?

 

i want the electrons to be noticeable but i fear the more extreame the difference in size of the elcetrons vs the ring stars the further the stars will seperate from thier perspective rings.

 

am i over thinking this or is this a valid concern?

[justanotherpyro]

One tip is that if you were to do a shell like this you would have to break it pretty damned hard to get that effect and to kick the "electron" stars out fast enough. Changing the stars position in the shell seems to me like it would be useless because no matter what they are close to a powerfull explosion. If you hit something with a car going 100mph its going to be basically the same as hitting it at 95 mph, just slightly less force, but not enough to matter.

[FREAKYDUTCHMEN]

Drill or punch lots of holes in the inner petal hemi's. 2 or 3 mm will work.

[ST1DinOH]

One tip is that if you were to do a shell like this you would have to break it pretty damned hard to get that effect and to kick the "electron" stars out fast enough. Changing the stars position in the shell seems to me like it would be useless because no matter what they are close to a powerfull explosion. If you hit something with a car going 100mph its going to be basically the same as hitting it at 95 mph, just slightly less force, but not enough to matter.

 

well i figured that the stars would all start out the same, but because the "elsectron" stars have more mass (and retain more mass longer as they burn) i thought they may seperate out away from the ring.

 

i read last night in one of my books that stars closer to the burst charge of a shell don't move as fast or as far fromthe burst charge as ones located near the inner shell wall. this would be easy to do if i just did one ring, with one "electron" because i could form the ring across the seam and easily place the larger star inward a tad to compensate for this uneven mass balance. but when trying to imagine doing 3 rings in an atomic pattern i'd have trouble offsetting the 2 non seam "electrons" and not having them shift on me.

 

hence the whole concept of hot glueing them to short craft tube "podiums" against the inner shell wall.

 

am i right to be concerned that the larger stars will be traveling faster, and burning longer if had them all touching the inner shell wall?

 

or should i just go with contrasting colors of the same size?

 

is it possible for two stars of the same size to appear as different sizes to the viewer on the ground? do certian star comps have a bigger "footprint" in the sky to make them appear larger?

 

Drill or punch lots of holes in the inner petal hemi's. 2 or 3 mm will work.

 

i like this idea...but wouldn't this prevent the inner petal from breaking if all the break forces are allowed to vent out the holes?

 

i keep imagining this falling wiffle ball filled with burning stars dropping out of my shell pattern?

 

is that even possible if the inner petals walls are too thick?