Eyegasm Posted March 9, 2016 Posted March 9, 2016 I had an idea for a cylindrical she'll or medium/large mine. I was wondering if anyone had seen it before or has any input on the idea. I envisioned a long cylindrical shell (3" or larger) or a medium mine. The shell launches vertical and at apogee ejects a parachute. As the shell falls it discharges alternating stars, and go getters at 1 second intervals (2-4 cycles) in a circular pattern and ends with the entire remaining hull becoming a single large spinner with report. I'm thinking under 4" or 6" would be impractical or just not enough. I still have to draw it up and do the math, but I think it's an OK project. What do you guys think?
AzoMittle Posted March 9, 2016 Posted March 9, 2016 Cool idea! Were you thinking something like this: http://imgur.com/X9Yf5El Weingart (?) has a section on parachute headings for rockets in his book. 1
Mumbles Posted March 9, 2016 Posted March 9, 2016 I wouldn't worry about trying to make things eject in a circle. It will be moving around enough that any real attempts at orientation will probably be futile. I'd instead look into how rising split stars/comets are made for shells. There's a description in Fireworks: the Art, Science, and Technique by Shimizu. There's also some very nice examples on the forum from Dean411. I'd also worry about making a parachute shell successfully before worrying about complex effects like this. Spinners, flares, etc. are easy to add. The biggest issue is the parachute not unfolding properly, and coming back to earth far too soon.
Arthur Posted March 9, 2016 Posted March 9, 2016 yes the issue is the parachute not the live bits. I have some commercial parachute shells in the store and they get less good at opening as they get older.
OldMarine Posted March 9, 2016 Posted March 9, 2016 (edited) I think you'd need to use a rocket to keep your orientation otherwise the tumbling shell would simply tangle up your shroud lines if the chute actually deployed.Someone here (pirotek?) posted a video with a short tutorial on parachute signal flares that might be helpful. I'm still looking for the video. Found it:http://www.amateurpyro.com/forums/topic/10526-signal-rocket-red-green-salute/?do=findComment&comment=139937 Edited March 9, 2016 by OldMarine
Eyegasm Posted March 10, 2016 Author Posted March 10, 2016 Those are exactly the concerns I had as well. The effect I was going for is something that would resemble a pagoda in spatial form as it fell adding levels from top to bottom. I had thought a rocket platform would be the easiest and most stable form, but then I was considering the weights. I haven't gotten around to the calculation yet, but I'm pretty sure I would need a fairly large rocket. For what I want to do or drasticly cut back on stars or eliminate the go getters ans replace them with stars. I'm still trying to narrow down exactly what kind of effect I can achieve without ordering an SRB from NASA or trying to rent a 16" gun from the Navy. 😆 Those two options are just a little out of my budget. Then again imagine how cool that would be. Using an SRB as a rocket display or a 16" Naval gun to launch a massive aerial shell. Just for kicks I would load it full of a magnesium strobe powder just to see how many dooms-dayers jump into their bunkers thinking they dropped the bomb. 😂😂😂 I'm pretty sure that would be my last act as a free man though.
OldMarine Posted March 10, 2016 Posted March 10, 2016 (edited) A 6lb rocket will lift a 6" cylinder heading. I imagine you could fit a bunch of goodies in there along with the chute.Another benefit of using a rocket would be no worries of lift gasses igniting the shell and a gentler lift. This would allow you to use less paper which increases payload weight. Edited March 10, 2016 by OldMarine
Eyegasm Posted March 10, 2016 Author Posted March 10, 2016 A very good point. And the rocket can be stabilized much easier as well. I would still prefer a 16" gun though. 😂
schroedinger Posted March 10, 2016 Posted March 10, 2016 Why would you need to rent a 16" gun from the nasa, fibreglass mortars in that size can easly be bought. 2
Eyegasm Posted March 10, 2016 Author Posted March 10, 2016 Now that was funny. Actually, before manned space flight they built a gigantic howitzer to fire shells into outer space with data packages on board. https://en.m.wikipedia.org/wiki/Project_HARP
Arthur Posted March 10, 2016 Posted March 10, 2016 Project HARP was a brilliant plan to put small objects into high flight -possibly low orbit. It was intended for sending tools and objects into space to have a tools on a space craft. The brilliance was it's low fuel cost, the down side was the massive acceleration in the barrel which prevented many objects and animals using the service.
OldMarine Posted March 10, 2016 Posted March 10, 2016 Start braiding some rope boys! We're building a space elevator!https://en.m.wikipedia.org/wiki/Space_elevator
MrB Posted March 11, 2016 Posted March 11, 2016 Start braiding some rope boys! We're building a space elevator!https://en.m.wikipedia.org/wiki/Space_elevator I've seen and read a bit about them elevators. It's a nice bit of kit, but apparently we don't have any material that could actually be used for the cabling. Speculations point in the direction of carbon nanotubes, but it's unconfirmed at this point. I think it's only a matter of time, but even so... Can you imagine suiting up in a space suit, just to sit in the elevator for 5-6 days? (Elevator speed, roughly about 300 km/h, a quite reasonable speed for a self climbing elevator. Well, we think. We don't build elevators that fast.) Anyway, thats crazy cool tech, but i doubt i'll ever get to see it. It IS just a matter of time, but mine might be to short...B!
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