Mumbles Posted May 16, 2006 Posted May 16, 2006 I can try to give some tips. Keep in mind I've never made a successful multibreak shell, so take this with a grain of salt Well, to be fair, I've only tried one, and the mortar was too small. Anyway, off to the multibreakedness. To transfer fire, a spoolette is used to create the delay between shells with the fire originating from top fusing the first shell. Another, albeit less orthodox, and considered "cheating" by some, is to side fuse. Primed timefuse/spoolette is sticking out the side of the canisters, and are all ignited by the leader. Obviously they should not be sticking out far to avoid being damaged by the lifting action. If it is only a 2 break shell, they can simply be top fused on one, and bottom fused on the other. Really long skinny shells sometimes have problems of breaking it half in midair. Meaning they just fold over upon themselves. This is where the sidefusing method comes in handy. It also allows the bottom shot to be put on top so it is subjected to less forces. Often times you make all the canisters separately, including spiking. Then you spike them all together. Not a huge number of verticals, but enough to hold everything together. Say about a vertical every inch or so, or at least 8 or 10, whichever is more. Sometimes people jam newspaper in between the shells to lessen the stress on the shells. especially on the bottom. A final outer paste wrap is used over everything. You need less lift than you think. The shells make a good seal to make use of nearly all the lift force. It is also not a problem if the shell is sticking out the top of the mortar.
Pretty green flame Posted May 16, 2006 Posted May 16, 2006 I'm guessing this is what a 4 beak shell looks like. Cool, so basicly there are multiple canisters stacked on top of each other and are conected with spollettes. Will attempt a 3" double break shell for a first try and we'll see how it goes.
joe609 Posted May 16, 2006 Posted May 16, 2006 Whats the smallest shell anyone has made? whats the smallest you could sensably build one?
ewest Posted May 16, 2006 Posted May 16, 2006 Smallest? I started out small, I made 9/16" x 1 1/2"Lg. They were fired out of a 3/4"ID mortar. United Nuclear used to have a tutorial on how to make them on their site. The shells are too small to really put anything in, so most of the time I just fill them with BP or Goex for small salutes. I wouldn't use flash for a salute because they only go about 30' in the air at best, and that's just too close for a flash salute. The BP works fine, it sounds like a little firecracker going off. I tried loading them with 1/4" cut stars but you really can't get many in there maybe 10 or so, and it's just a waste of stars as far as I'm concerned. One thing I like to do with them is to string a bunch together into a 9 or 16 shot cake. I know it sounds goofy, but they're quick and fun to make and kids get a hoot out of them because they're so small. here's a pic of the last one I did, I used plastic plugs in the ends of the shells and that's what you see stuck down in the mortar
optimus Posted May 17, 2006 Posted May 17, 2006 You can get reasonably good star breaks with such small shells. Just use a slow burning AP microstar formula - with very small stars, and break with slow or 'dirty' flash. The Chinese employ these kind of bombettes in alot of their cheap cakes. I'd say making a shell smaller than around 1/2-3/4 is starting to get a little pointless, but it's possible.
PyroJoe Posted May 17, 2006 Posted May 17, 2006 I just launched a good 3" shell last night. With 5/16" blue stars. It was a paper ball shell with 3 layers of recycled craft pasted on to it and was lifted with 17 grams of homemade lift. The shell weighed about 120 grams. Video:3" Spherical blue shell You can hear my dad and brother commenting when the quickmatch stopped for a second I rolled the quickmatch tube 15 minutes before the launch. That may have been why! P.S. The blue stars looked awesome! My dad's camera just didn't pick up the color worth crap. I think my old analog 8mm camcorder picks up colors better than my dads digital, at least for fireworks.
Mumbles Posted May 17, 2006 Posted May 17, 2006 It looks pretty good. 3 layers of pasting, even with double layers seems a bit on the low side though. If it was a thicker kraft, 60 or 70lb, then it may be alright. I believe I put on 5, maybe 6, double layers of recycled 30lb the last few times I've made paper ball shells. I don't have everything dialed in yet, but they are certainly strong enough.
PyroJoe Posted May 18, 2006 Posted May 18, 2006 Oh yeah, I would have liked to put at least 6 layers on, but I didn't have the patience! I hate pasting with a passion, at least when I only have one shell to do. If I have a whole line up then ill get into it and by the time I get to the end of the line the first shell is dry enough for another layer. It just seems like it goes faster when there are more to do.
Pyrohawk Posted May 18, 2006 Posted May 18, 2006 I agree completely!!! I hate pasting so badly!! Not to mention my paste jobs always look like crap..... I've tried so many different ways and my paste jobs always look bad.... I've tried 3 different glues and 2 different shapes of paper not to mention different sizes to no avail. Part of my problem is that my hemi's are rough and uneven to start with.
justanotherpyro Posted May 18, 2006 Posted May 18, 2006 Thin strips vertically is what the commercial 2" shells I buy have. I dissasembled one a long time ago and folllowed the pasting procedure and had good results. About 1/2 -3/4" wide shifted in the same direction about 1/8-1/4 an " each time for a 3" shell works well. With enough strips and a good rythm you can get a good paste job fairly fast.
al93535 Posted May 18, 2006 Posted May 18, 2006 Hahahahaha Pyrohawk, how long was your shell sitting waiting to be pasted? I actually rather enjoy pasting, but then again, I do enjoy just about every step of making a shell. Maybe its more I want everything to be just right so I don't mind. Anyways, I only put 4 layers of 70 lb recycled kraft on my shells. Thats 4" and 6" shells, but every layer is doubled, so its more like 8 layers. After that I add two layers of 30 lb kraft to smooth everything out. And Pyrojoe: Man that was an excellent break!! What did you use for break?It almost looks like the stars lit, then went dark, and then came back to life! Good job Pyrojoe! Are you going to submit it in the competition?
Chris Posted May 18, 2006 Author Posted May 18, 2006 PyroJoe, that was a really good break. I'm suprised that 3 layers was enough, even with strong paper. Did you use any flash for break? I normally use 9 layers of 30-40 lbs craft for my 3". Since I place every paperstrip in the middle of the last one, the true count of layers is double. Has anyone tried pasting shells with pregummed tape? I believe it's used commonly in the orient, and it seems to be a very fast and neat alternative compared to strips and paste.
ltf Posted May 18, 2006 Posted May 18, 2006 Wow, very nice shell, the breake was very round and symmetrical.A shame that the camera didn't work well.
PyroJoe Posted May 18, 2006 Posted May 18, 2006 The stars had a pretty thick layer of prime on them, so you are seeing the green mix light at the very beginning, then it moves to the perchlorate prime which makes it go dark and then to the actual blue star. It was a cool effect! Thanks for all the comments. I used about 1 gram of flash on BP coated rice hulls for the break. I probably won't be putting this one in the competition mainly because I want to get a better camera that will capture the color well. Im going to roll a bunch of tigertail stars and tigertail-blue stars next. Then I can start on my 4" shells. Im still deciding on some red and green compositions to use. I have a bunch of magnesium im planning on using, but I have never used magnesium in star comps. Does anybody have experience with magnesium? Also, are magnesium based comps difficult to roll since you have to use acetone and alcohol as the solvents?
Pyrohawk Posted May 19, 2006 Posted May 19, 2006 Hahahahaha Pyrohawk, how long was your shell sitting waiting to be pasted? Uhhh about 3 weeks In fact there is one sitting on my desk right now ready to be pasted.... Wonder how long till I paste it?! Today is 24hours since I made it so we'll see!! Very nice shell Joe! It's to bad the camera made the stars appear dim.... Mine does that to. What did you use for break?
Douchermann Posted May 19, 2006 Posted May 19, 2006 Does anybody have experience with magnesium? Also, are magnesium based comps difficult to roll since you have to use acetone and alcohol as the solvents? Just fill your spray bottle with 99% isopropyl if it calls for alcohol only. I'm sure you could use water on coated magnesium though.
PyroPicasso Posted May 20, 2006 Posted May 20, 2006 I have heard of people creating coconuts in a palm tree shell. I however have never seen this effect. What is used, yellow tailless stars, salutes, dragon eggs, or something else?
Spoony Posted May 22, 2006 Posted May 22, 2006 Well, my shell was a complete screw up. It went off in the mortar, and all that was left was a blackened peice of wood. I guess the fuse skipped or there was a gap around the fuse. I doubt it was the lift, I only used 10g. Ah well, live and learn.
Mumbles Posted May 22, 2006 Posted May 22, 2006 I would think coconuts would best be done as some sort of insert. You'd want something that stands out from fronds. Here is some work I did previously on palm shellshttp://www.xsorbit2.com/users/apcforum/ind...0145411&start=0
al93535 Posted May 23, 2006 Posted May 23, 2006 Ok here is my latest shell. It is a 4" can about 10" long, it weighs in at 1420 grams, and uses 93.3 grams of -6+12 lift powder. There are 30 timed hummers, so 3 waves of 10, which will fire about half a second apart. Then I have 10 Titanium salutes (5 grams) which will go off after the last hummers. Then a 60 gram titanium bottom shot. This should be a fun shell! And yes it was a bitch rolling 40 tubes, then ramming 30 of them with plugs and comp Inserts: http://img.photobucket.com/albums/v242/al9.../insertsbs1.jpg http://img.photobucket.com/albums/v242/al93535/insertsbs.jpg Pasted and spiked: http://img.photobucket.com/albums/v242/al9...pikedcanbig.jpg Finished: http://img.photobucket.com/albums/v242/al93535/bigcan.jpg
mr.pyro Posted May 23, 2006 Posted May 23, 2006 I hope you fire that thing tonight... I want to see that video.
dragonman586 Posted May 23, 2006 Posted May 23, 2006 Ooh thats bootiful. I wish I could shoot stuff like that here. Or atleast had the time to build something like that.
PyroJoe Posted May 23, 2006 Posted May 23, 2006 Great looking shell Al! I can't wait to see that one. I think im going to go look for some gummed craft tape at Staples and office max to make my shell pasting an easier process. Al don't you use gummed craft tape to paste your shells? I was wondering how you wet the tape, so it has just the right amount of water.
Pyrohawk Posted May 24, 2006 Posted May 24, 2006 Looks like it only took 6 days this time.... I just finished pasting my 3" shell. Dang I hate that job. Plus it always ends up looking like crap!! I have tried everyones ideas on pasting and somehow mine still sucks. the paper just doesn't form to the shell! Maybe my paper is to thick or heavy?? Its quite thick.... I can't remember what weight it is or whatever but maybe its just to thick..... But I also know that my hemis are so rough that hurts a lot....
al93535 Posted May 24, 2006 Posted May 24, 2006 PyroJoe: No I use kraft paper and thinned wood glue. Ravaz uses gummed tape though. Pyrohawk: Do you use thinned glue? If you are using thick paper I suggest wetting the paper with water a bit first, then smoothering it with glue.
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