08-03-2006, 11:03 PM
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BARCLONE Rocketry
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Join Date: Mar 2005
Location: Mobile, Alabama
Posts: 5,357
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New Plan -- ViperJet 4256
Talk about procrastination, I've had this rocket sitting off to one side for so long, I've forgotten how long I've had it. Maybe six years...
The LHS had this LOC Viper 4 in stock probably since the day they opened, and that was long enough for the price sticker to fade, yellow, and crack. I'm not really sure why I bought it, other than I was just looking for "something bigger" than a typical modroc. I didn't particularly care for the fin shape of the Viper, but figured I might find a better fin shape sometime in the future...
Well, it's "Back to the Future" time, and the inspiration is a combination of several EnerJet fin patterns, with a contribution from not just a few Estes models...
The ViperJet 4256...
Length: 45"
Diameter: 2.63" (LOC 2.56)
Fin Span: 12.06"
Weight: 15.5 oz
This is a high-performance cluster model, requiring four (4) 24mm motors. All motor combinations (except the poor E9-8) will reach flight V on a 48" rod, 1/4" diameter.
(4) C11-3..................270'......20 FPS......Margin 4.18
(4) D12-5..................783'......23 FPS......Margin 3.97
(4) D15-6..................992'......11 FPS......Margin 3.93
(2) E9-6 + (2) D12-7......1112'......36 FPS......Margin 3.69
(4) E9-8..................1438'......30 FPS......Margin 3.45 (Needs 56")
(4) E18-8.................2305'......27 FPS......Margin 3.58
(4) E6-8..................2347'......28 FPS......Margin 3.86
(4) F72-10................3879'......47 FPS......Margin 3.31
(4) F32-10................4252'......32 FPS......Margin 3.17
(4) G37-10................5277'......56 FPS......Margin 2.81
The LOC 50" nylon parachute is used for recovery. Use birch plywood, 1/8" thick, for the new fins. All Dv values above 25 need to have their parachute lines reefed to prevent an explosive opening, which may result in a shredder...
Enjoy!
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