crazyboy25 Posted July 21, 2008 Posted July 21, 2008 WOW that was incredible I love the double helix on the way up. I never thought of the Thai as innovators in pyrotechnics like the Maltese or Japanese but that was incredible.
cplmac Posted July 21, 2008 Posted July 21, 2008 Yeah that was a really innovative way of mounting the vertical drivers. I've been trying to think where I could shoot a girandola that big stateside, if I can come up with a reasonable solution I will build one. I've been trying to think of ways to make large lightweight frames, there are a LOT of options. I plan on making Mason City next year, if they have a large enough shoot site I'll bring a 6 foot diameter girandola. I think if I can keep the frame and motor weight under 100 pounds I can get one to fly.
Frozentech Posted July 22, 2008 Posted July 22, 2008 I think if I can keep the frame and motor weight under 100 pounds I can get one to fly. Well if you are going to build a really expensive high tech one, perhaps you can buy carbon fiber tubing, something that can bend like a Shakespeare "Ugly Stik" fishing rod. That would sure keep the weight down.
ULTRABUF Posted July 22, 2008 Posted July 22, 2008 Wow those girandolas were amazing, that smoke trail was awesome. I guess I should have been keeping up on that thread at passfire, woulda seen this sooner.
TheSidewinder Posted July 22, 2008 Posted July 22, 2008 Yeah that was a really innovative way of mounting the vertical drivers. I've been trying to think where I could shoot a girandola that big stateside, if I can come up with a reasonable solution I will build one. I've been trying to think of ways to make large lightweight frames, there are a LOT of options. I plan on making Mason City next year, if they have a large enough shoot site I'll bring a 6 foot diameter girandola. I think if I can keep the frame and motor weight under 100 pounds I can get one to fly. If you can get your hands on the proper sized Bamboo, I think the weight would be a non-issue. Although that "proper sized Bamboo" might be an issue.
Rob Allen Posted July 23, 2008 Posted July 23, 2008 I'm sure no one gives a crap about my dodgy shit, it's all bout girandolas.... I tried the straiaght BP with a much bigger nozzle and yeah same problem but I seem to have fixed it by using RC for the first quarter of the engine and BP for the last 3 with a short core, seems to work well. I didn't post the ones that worked out just the one that f'd up. and a glitter shell that f'd up 2, I know it should be in the other post but it's on the same vid basically the time fuse was too quick! I've launched successful shells with the same fuse, I've tested it but yeah must have some inconsistency in that batch have to scrap it and make more. http://www.apcforum.net/files/rocketedit2.mov Was shot it the rain so no fire risk!
cplmac Posted July 24, 2008 Posted July 24, 2008 I'm getting the feeling you might not be pressing it hard enough. Are you pressing or ramming? How big are you increments? A good rule of thumb is that an increment should compress to roughly the ID of your motor. So if you are pressing a 1" motor your increments should take up 1" of space in your motor after it's pressed, less is okay, more is where you run the risk of not properly consolidating your fuel grain and you could experience CATO's. How long was your core? On the girandola, I was thinking possibly rattan, but I might use aluminum, depends on what I spot in the next month or so that looks right at the time.
Rob Allen Posted July 24, 2008 Posted July 24, 2008 I don't think I'll be able to press it as hard as you could but I'm using a 6t press, my increments are not perfect, I need to work on making them more even and smaller amounts as you say. core was about 2cm into the fuel past the nozzle, the entire length of the engine was about 7cm. In slow mo you can see the rocket is expelling gas for a second or two and just about to take off before cato. I've used a cooler fuel like I said at the base for roughly the first quarter and the hotter BP for the last 3 and it seems to work as long as my core doesn't pass through to the BP. Probably not the best way of doing it
cplmac Posted July 27, 2008 Posted July 27, 2008 There are a lot of ways to slow down your motor, but it's important to rule out construction errors first. Try smaller uniform increments. If that doesn't work try a shorter core or wider nozzle. You could try no core, if it flies then your nozzle is not big enough for a core.
cplmac Posted July 28, 2008 Posted July 28, 2008 My first 8" shell Lots of problems with this shell but mechanically it functioned properly which is more than I can say for the camera. It needs more break, less time fuse and more lift, next one should be in the air in a couple days.
nath0r Posted July 28, 2008 Posted July 28, 2008 Nice shell cpl, I thought the downward break actually looked pretty cool . What did you use for break? Hope the next one functions even better
MilkyJoe Posted July 28, 2008 Posted July 28, 2008 nice upside down starmine! looking forward to the next one.
cplmac Posted July 28, 2008 Posted July 28, 2008 My girandola threw a motor, still flew strangely enough 6lb thrust tooled whistle with brilliant orange Ti comet
FREAKYDUTCHMEN Posted July 29, 2008 Posted July 29, 2008 cplmac, those whistle girandola's are made of endburners right?
TheSidewinder Posted July 29, 2008 Posted July 29, 2008 That 'dola was spinning pretty smartly when it threw the motor off, but still kept going. Well-made, I'd say. Good rocket, too. Very nice all around.
hst45 Posted July 30, 2008 Posted July 30, 2008 4th of July, 2008. 3" ball shell, whistle-boosted break, spheroidal Al. Kind of thin, but pretty good height and good spread. I give me a B+. Comments/ratings/advise appreciated.
Frozentech Posted July 30, 2008 Posted July 30, 2008 4th of July, 2008. 3" ball shell, whistle-boosted break, spheroidal Al. Kind of thin, but pretty good height and good spread. I give me a B+. Comments/ratings/advise appreciated. I'd give you a couple extra credit points on that shell, it wasn't thin at all for a 3" ball shell. Also, your D1 glitter works very well.
nath0r Posted July 30, 2008 Posted July 30, 2008 I agree with Frozentech, really nice shell. Well done!
qwezxc12 Posted July 30, 2008 Posted July 30, 2008 As all above, nice shell hst! Either you make tight fitting shells or you love to over-lift those suckers...my 3's just go "pop", not "WHAM" when they launch Nice break, and I agree, the pattern wasn't sparse by any means. Nice glitter, too. Whose/what atomized Al are you using? I noticed I get the best delayed flashes and hang-time from some shitty, half-oxidized, garbage Al from Plans and Kits Unlimited (yes, the infamous "won't make flash" Al from a year or so ago)...go figure. I get a denser and brighter, but shorter duration glitter from Hawk Mtn's 20-30um atomized.
cplmac Posted July 30, 2008 Posted July 30, 2008 cplmac, those whistle girandola's are made of endburners right? They are basically big whistle inserts, no nozzles whatsoever. Hst, nice shell! For a 3" that's pretty good symmetry on a glitter shell.
TheSidewinder Posted July 31, 2008 Posted July 31, 2008 Very nice, Mac!! Beautiful rising tail and good symmetric burst.
psyco_1322 Posted July 31, 2008 Posted July 31, 2008 Wow, very nice shell cplmac. There was nothing quiet about that one. Loud shot and break. Was that tail commercial?
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