Mixer Posted June 9, 2016 Posted June 9, 2016 (edited) If anyone is interested in making these I have a Tutorial I could dig out. https://www.youtube.com/watch?v=utqnO1DBFyk https://www.youtube.com/watch?v=7mikXso4T_g https://www.youtube.com/watch?v=N38GI7Bm3f0 Edited June 9, 2016 by Mixer 1
lloyd Posted June 9, 2016 Posted June 9, 2016 I taught a class on making them at one FPAG Fall Festival. The very next day, there were folks making and shooting versions as large as 1.5" i.d.... and just about all of them worked! LLoyd
ddewees Posted June 9, 2016 Posted June 9, 2016 I'd love to see videos... never seen a homemade one before. I love those things.
memo Posted June 9, 2016 Posted June 9, 2016 that would be great Lloyd if you can find it and post it, I am interested also. memo
lloyd Posted June 9, 2016 Posted June 9, 2016 nah... not on this computer, anyway. They're REALLY simple to make. Just picture a spin-stabilized rocket, but with the spin hole at the end OPPOSITE from the thrust nozzle, and with the thrust core not extending the full length. They're fused in the spin hole. When lit, the thing first spins (like a ground bloom). When the fire reaches the tip of the core, it then continues to spin and also thrusts out the other end. However the precession forces interact, they nearly always then erect themselves thrust nozzle down, and up the go spinning fast enough to make the singing tone as they go. Cute changes include using different colors or powder types for the spinup and thrust portions of the core. So basically, you just ram a small nozzled rocket with a core that doesn't reach quite to the top of the fuel grain. Use a slow enough powder so that it can be BOTH cored AND nozzled. Press and clay-cap just as you would any normal nozzled rocket. Then drill the tangential spin hole as close to 'just under the clay' as you can at the top end of the tube. LLoyd LLoyd
Mixer Posted June 9, 2016 Author Posted June 9, 2016 I`ll post it in the `Member Tutorials` section in a few minutes.
FlaMtnBkr Posted June 14, 2016 Posted June 14, 2016 I see that. And I thought it was supposed to be radial which is why I asked. Like a ground bloom flower. With it tangential it is essentially a spin stabilized rocket.
FlaMtnBkr Posted June 15, 2016 Posted June 15, 2016 There are quite a few videos on YouTube of commercial versions. Many with little kids lighting them and not great video quality. I would post a link but I'm about to break my phone because it keeps messing up so going to stop while I'm ahead. Just search for one of the above names along with 'fireworks'.
FlaMtnBkr Posted June 15, 2016 Posted June 15, 2016 Oh, and from the videos the fusing hole does look radial. I think I would use a slow comp above the core to try and extend the ground spin time.
OldMarine Posted June 15, 2016 Posted June 15, 2016 (edited) Dan, Caleb has video on his youtube channel of some he made. Edited June 15, 2016 by OldMarine
Mixer Posted June 15, 2016 Author Posted June 15, 2016 I posted three video`s! Trust me - if you follow exactly the tutorial directions without deviation, the end product will be as you see in the vids. I have seen many attempts fail dismally when the method and specs have been changed.
dagabu Posted June 15, 2016 Posted June 15, 2016 I have seen similar items with a small report at the end, how is that accomplished?
FlaMtnBkr Posted June 15, 2016 Posted June 15, 2016 Those slow motion vids almost look like they are spinning about their long axis like a spin stabilized rocket. They spin so fast that they almost have to correctly orient themselves because that introduces the least inertial, air, and friction resistance. And things like to orient in a way where the least resistance acts on them. But what Lloyd describes is a spinning about it's short axis like a ground bloom flower. I have in my notes from almost ten years ago that he said the fuse hole is drilled radially. And it spins like a ground bloom and as the fuel is consumed and the center of gravity changes it erects itself like Viagra was crushed and added to the BP. Ok, kidding, but he used a technical term I don't exactly remember. Gyroscopic progression? Anyways, the ones in videos are neat but they fly off too quick for my tastes. Lloyd's version sounds more appealing to me. Though as he pointed out they may not always go where you want them if they aren't completely erect when time to perform. Sorry, it's just too easy not to.
BlueComet24 Posted June 16, 2016 Posted June 16, 2016 I once tried to make a large ground bloom flower using a 25.4x63.5mm (1x2.5") tube with 2.4mm (3/32") walls. I rammed a clay plug into the bottom, drilled a tangential fuse hole/nozzle just above the clay, fused it, and filled it up with sorbitol rocket candy catalyzed by about 1% Fe2O3.Expecting it to spin all over the ground like a souped up ground bloom, I put it on a large, flat surface, lit it, and ran. It spun like a ground bloom for a second, then righted itself and took off vertically, reaching an apex of about 10m! I was very surprised that it flew, and especially so well. Its only nozzle was the tangential one.
FlaMtnBkr Posted June 16, 2016 Posted June 16, 2016 It probably burned the paper so there was a bit of a downward vector to the exiting gases. With a little down force it's light enough that it should be able to climb fairly well. If you used an angled rammer for the clay and drilled an angled vent thru the side wall of the clay so the hole doesn't erode too quick, you could probably make them take off every time.
dagabu Posted June 17, 2016 Posted June 17, 2016 I finished my drilling jig today, tangential hole but no angle, both the vent and nozzle are .33" (aprox) and the fuel chamber is 1" x 3" approximately. I'll be heading off to my build site in the morning and will press one with hot BP for testing.
lloyd Posted June 17, 2016 Posted June 17, 2016 In reply to "tangential" or "radial". They work either way. And they spin like a ground-bloom before lifting, either way. They tend to "sing" better if the hole is tangential. Gyroscopic precession! <G> Lloyd
FlaMtnBkr Posted June 18, 2016 Posted June 18, 2016 Ahh yes, that's it. I remember a lot but not quite everything. Now if I just new what it actually meant.
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