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  #31  
Old 09-15-2016, 08:06 AM
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A sonic boom from such a small object is actually a crack and you have to stand a distance away from the pad to hear it. Near the pad, you are within "the cone of silence" according to agent 86.
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  #32  
Old 09-15-2016, 10:41 AM
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Quote:
Originally Posted by stefanj
According to carbon4, who worked at FSI, the "supersonic" booster F100-0 had another difference. There was a layer of black powder added on top, held in with nitrocellulose dope.

I suspect that the whole supersonic thing was a bit of a trick. The "boom" was really a "bang," of that charge going off and the tight-fitting D20 popping out.


All F100-0 motors had a short delay and granular black powder (ejection charge material) held in with clear dope rather than the cardboard disc used on other FSI normal motors. The reason is that the F100-0 would not hold in the pressure of combustion without the delay grain on top of the propellant. The short delay was only a couple of seconds and did not affect any two-stage flights I made or saw (other than adding a bit of altitude).
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  #33  
Old 09-15-2016, 10:45 AM
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Default FSI Dart

For those interested. Note: I'm pretty sure my memory is correct; the Dart had a hardwood nose cone.
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  #34  
Old 09-15-2016, 12:46 PM
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Quote:
Originally Posted by Rocketflyer
For those interested. Note: I'm pretty sure my memory is correct; the Dart had a hardwood nose cone.


Pine is a softwood.

Balsa is a hardwood.

https://en.wikipedia.org/wiki/Hardwood

https://en.wikipedia.org/wiki/Softwood

"Softwoods are not necessarily softer than hardwoods. In both groups there is an enormous variation in actual wood hardness, with the range in density in hardwoods completely including that of softwoods; some hardwoods (e.g. balsa) are softer than most softwoods, while the hardest hardwoods are much harder than any softwood. The woods of longleaf pine, douglas fir, and yew are much harder in the mechanical sense than several hardwoods."
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  #35  
Old 09-15-2016, 02:48 PM
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Quote:
Originally Posted by Shreadvector
Pine is a softwood.

Balsa is a hardwood.

https://en.wikipedia.org/wiki/Hardwood

https://en.wikipedia.org/wiki/Softwood

"Softwoods are not necessarily softer than hardwoods. In both groups there is an enormous variation in actual wood hardness, with the range in density in hardwoods completely including that of softwoods; some hardwoods (e.g. balsa) are softer than most softwoods, while the hardest hardwoods are much harder than any softwood. The woods of longleaf pine, douglas fir, and yew are much harder in the mechanical sense than several hardwoods."


Well Fred, I don't recall the Dart having a Balsa nose cone, and I don't care what YOU, or Wiki says, balsa nose cones are soft.
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  #36  
Old 09-15-2016, 03:15 PM
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Just substitute the word "Sheldon" for "Fred", rocketflyer.
In most instances it is fitting as he often provides information that nobody cares about with a 'smarmy' attitude to boot.
EVERYBODY but FRED knows that the poster was pointing out the nose cone on the FSI Dart is made with a material that is HARDER than Balsa in both feel and workability, NOT some smart-a$$ed whack-job definition.
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  #37  
Old 09-15-2016, 03:16 PM
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Quote:
Originally Posted by ghrocketman
Just substitute the word "Sheldon" for "Fred", rocketflyer.
In most instances it is fitting as he often provides information that nobody cares about with a 'smarmy' attitude to boot.
EVERYBODY but FRED knows that the poster was pointing out the nose cone on the FSI Dart is made with a material that is HARDER than Balsa in both feel and workability, NOT some smart-a$$ed whack-job definition.


Thanks gh, you said it all for me!
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  #38  
Old 09-15-2016, 03:17 PM
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The earliest FSI kits did indeed have hardwood nose cones they were birch if I recall correctly. FSI listed them as hardwood cones in their catalog for as long as I can remember probably until they went out of business. They did switch to Pine in later years and Pine is technically a softwood. Trees with needles also known as conifers are considered softwood trees with leaves are considered Hardwoods the density of the word varies Balsa is the least dense Hardwood
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  #39  
Old 09-15-2016, 07:26 PM
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Beavis and Butthead would die of exhaustion laughing at all this talk of hard wood.
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  #40  
Old 09-16-2016, 08:22 AM
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Quote:
Originally Posted by tbzep
Beavis and Butthead would die of exhaustion laughing at all this talk of hard wood.


Heh, heh, he said hard wood, heh, heh.
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