hashashan Posted September 21, 2007 Posted September 21, 2007 The spolettle was perfect it burnt its 3 seconds. The shell was 3" Spherical and yes there was a quick match attached to the end of the spoulette. This could be the reason? What to do in order to avoid this problem? PS of course i didn't find the shell. I also didn't estimate the power of my BP and put 1/5 .. i should use 1/7-1/10 and the shell was lifted to an unbelievable height. So no way I could find it.
pudidotdk Posted September 21, 2007 Posted September 21, 2007 How did you construct your spolette?If you didn't use black match and firetransfer cavity, the fire might not have reached the bursting charge:http://pyrobin.com/files/spolette.jpg
hashashan Posted September 21, 2007 Posted September 21, 2007 Thanks for the drawing. Mine was not exactly like that. The spoulette was without the hollow part it was all filled with BP and set to 3 seconds., the quick match was taped to the end of the spoulette. Ill consider using such a design next time. PS. where is the picture from? do you have more pictures like that?(I mean on various pyro related issues)
psyco_1322 Posted September 21, 2007 Posted September 21, 2007 thats like a salute I made once, visco burned right into it and it didnt go off. At the convention I had a rocket that didnt even shoot fire through the pass fire hole. Had a shell once that the fuse burned into and it didnt go off either. It happens some times, weird things happen some times. Your spoulette could have shot the fire down and out instead of up and in, maybe the tape blocked the fire passage, could be it stopped burning to some odd reason at the last bit of powder. If it was only a 1/16" of powder you wouldnt be able to tell it didnt burn.
Pretty green flame Posted September 21, 2007 Posted September 21, 2007 Another thing you might want to look into is a "special" rammer. Basicly a rammer but shaped into a pointy bit at the end so when you ram your last increment you create a V shaped recess in the powder core causing the spolette to spit fire into the shell. This technique works very well, i've had no failures using this technique. Cheers
psyco_1322 Posted September 21, 2007 Posted September 21, 2007 That does sound like it would be a very good idea. Just that I dont use spoulettes, too much work, fuse is much easier. Ya you should try that cone idea, it eliminate a possible non-ignition.
frogy Posted September 22, 2007 Posted September 22, 2007 What size pulverone must be used to lift 2", 2.5", and 3" shells? I was using 5 grams of about 20-40 mesh white pine w\ 5% dextrin pulverone to lift a 40 gram 2.5" test shell (about half full of kitty litter) and the shell barely cleared the tube... I think I'm either having to go buy Goex Cannon grade, or make a powder die... I have some 3" Solid Core PVC, and I can go buy a repair coupling and some hose clamps, but I don't really now what size to make the pistons, or how to solidify fiberglass resin... I've been looking at Dan Williams page here:http://www.pyrotechs.org/dwilliams/powderdie/powderdie.html and the APC thread here:http://www.apcforum.net/forums/index.php?showtopic=1872 Lloyd says he mixes "sharp" masonry sand with polyester resin and hardener The top piston ram is 5.36cm high.The 8 oz. mark is 1.46 cm below the top.The base cylinder enters the compression sleeves by 0.8cm.The compression sleeves are 3 in. or 7.62cm long. I can get fiberglass resin, sand blasting\masonry sand, and hardener... But how long should I make the pistons? He says 24 fl. oz resin + 1 dry quart sand = piston, but doesn't specify top or bottom... Top piston = 5.36cm... Why do you cut slits into the compression chamber and piston? PS: Great shells Zmuro.... The TT to D1 are great and I like the last TT shell that broke in a fan shape, if that was accidental or not...
asilentbob Posted September 22, 2007 Posted September 22, 2007 Made a 4" Win20 shell with old pumped 3/4" stars... They were kinda brittle... I'm thinking that several will split on burst. Also threw in a couple pieces of crackling fuse. Filled with BP/crispies 2-3.5/1 (can't remember) and like a half teaspoon full of whistle just dumped in and mixed around. Haven't pasted it yet... I'm going to be using this nifty 120lb/sq-inch fiberglass crazy braided packing tape and then pasting over that with gummed kraft tape. Thinking i might add a Win20 or D1 3/4" "comet" and/or a long piece of crackling fuse and/or 2 1-3/4" rising shells... Will be lifted with around 1/14-1/12th its weight in GOEX 1Fg. Thinking ill make a lampari shell or 2 next... minus the fuel for now... Then... I don't know.
LGM Posted September 22, 2007 Posted September 22, 2007 Has anyone used black match as a burst? The idea just popped into my head reading this thread.
frogy Posted September 23, 2007 Posted September 23, 2007 I just lit a pile of blackmatch shreds compared to some 4:1 crispies and it was completely different... Blackmatch just burnt from one side of the pile to the other decently fast... While the BP coated crispies instantly made a poof and was gone... Both the blackmatch and coated crispies were 5% dextrin and sufficiently dry... BM might work if it's fast, but it doesn't really pass fire that fast because it's thin\flat...
deadman Posted September 23, 2007 Posted September 23, 2007 If BM is in confinement then the hot gasses from one side should technically flash to the other side like in QM. It's the same reason we use granulated BP instead of meal so it all ignites as fast as possible. The problem I see arising from using BM is that it would be hard to control the shape of it, as well as not adding support to hold the stars close to the walls of the shell.
Mumbles Posted September 23, 2007 Posted September 23, 2007 Blackmatch should theoretically work as burst, just as any other carrier. I do see a few problems. The first of which is fallout. The string from blackmatch does not always burn completely, which may result in string embers raining to the earth. The second is compressability. String is fairly compressable, which makes it less than ideal for burst charges. The last of which is cost. I would imagine a large amount of string would have to be used in order for it to function as a burst compared to say BP on hulls. 100 feet of string is certainly more expensive than 30g of hulls. While it may not be replacing the well known standards, there is no reason it shouldn't work.
Zmuro Posted September 23, 2007 Posted September 23, 2007 Some shells from saturday.http://www.youtube.com/watch?v=RXNt2BEIuLQhttp://www.youtube.com/watch?v=JqggQ7j-F_4http://www.youtube.com/watch?v=ejwOO80s5JIhttp://www.youtube.com/watch?v=F_MrA5l18wAhttp://www.youtube.com/watch?v=O2A14FLFvlQ
ULTRABUF Posted September 23, 2007 Posted September 23, 2007 Very nice shells zmuro. What kind of hemis did you use on the round shells, paper or plastic?
flying fish Posted September 24, 2007 Posted September 24, 2007 Amazing shells Zmuro. What kind of charcoal are you using for the Tigertail?
Zmuro Posted September 24, 2007 Posted September 24, 2007 Very nice shells zmuro. What kind of hemis did you use on the round shells, paper or plastic? I use homemade paper shells, pasted with fiberglass and polyester resin. For TT stars I used common grill charcoal.
flying fish Posted September 24, 2007 Posted September 24, 2007 Neat! Do you use the charcoal briquets, or the "natural" stuff? Do you know what brand the charcoal is?
Zmuro Posted September 24, 2007 Posted September 24, 2007 Neat! Do you use the charcoal briquets, or the "natural" stuff? Do you know what brand the charcoal is? I use "natural" stuff and not briquets, I don't know what brand it is, I bought it from local gas pump. Briquets are not good for making stars.
ULTRABUF Posted September 24, 2007 Posted September 24, 2007 I lit off 4 shells last night, 3 of which were successfull. Unfortunately no video, my brother and I arent allowed to use the camera anymore because he deleted a bunch of my stepmoms stuff off of it. I dont think I'm going to light off multiple shells at my usual site anymore, the police were driving around afterward.
Cherbanov Posted September 24, 2007 Posted September 24, 2007 I just fired my first and second 3" shell to night. it was a really niceto see. this is really fun to get something right when you do it all byeyour self. thanks to you all, I`ll been reading lots and lots of info hereso you have made it possible for me to make my shells. did use a little to mutch lift, 15g to 120g shell. it went far to high but wath thehell
Mumbles Posted September 24, 2007 Posted September 24, 2007 From the weight, I'd say they were ball shells. Ball shells require more lift per mass than canister shells, as cans can more efficiently use the lift gases. 3" Ball shells are still in the realm of small where generally more lift than theoretically needed is used. 3" canisters routinely use 30g, and balls routinely use around 20g. This is for commercial 2FA. I find a smaller grain size to work better with smaller shells like these anyway. 20g of say 3-4FA will get them up nice and high.
psyco_1322 Posted September 24, 2007 Posted September 24, 2007 Umm... Mumbles you just said that balls use more lift and then listed the canister using 30g and the ball only using 20g.
Mumbles Posted September 24, 2007 Posted September 24, 2007 If you read it a bit more carefully. I said they require more lift PER mass. No biggie. It's an easy mistake. It's only really true of smaller shells anyway. Once they get to be 5 or 6", I use 1/16 reguardless, even though one may go higher than the other. 20g/120g = 1/6 30g/240g-300g = 1/8 - 1/10
psyco_1322 Posted September 24, 2007 Posted September 24, 2007 Oh I see what your talking about now, just wasnt thinking.
jacob Posted September 26, 2007 Posted September 26, 2007 Psyco, what did you use in that lampare? i can't figure it out, and if it took Mumbles a while to find out i'll probably never get it .
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