David, I was conflating two perennial debates in attempt at humor. oh well.
(I tried foam in the fin can once; doesn't add strength, makes repairs
difficult, is hygroscopic, fail. but if you like it...)
On 2015-11-04 15:23, David Smith wrote:
Linear Polyurethane foam on the shock cord?
I use PML adjustable foam for fin cans and nose cones...
David P Smith
Tripoli 15803
NAR 78668
Amateur Extra: W6DPS
ROC Board Member
On Nov 4, 2015 3:19 PM, "Cliff Sojourner" <cls@xxxxxxxxxxxxx <mailto:cls@xxxxxxxxxxxxx>> wrote:
On 2015-11-04 14:01, David Smith wrote:
I always like to have my launch lugs free to spin.
And prefer tubular nylon shock cords...
hey David, what kind of LPU foam do you use on the shock cords?!?
Cliff
David P Smith
Tripoli 15803
NAR 78668
Amateur Extra: W6DPS
ROC Board Member
On Nov 4, 2015 1:59 PM, <kramer@xxxxxxxxxxxx
<mailto:kramer@xxxxxxxxxxxx>> wrote:
The first launch of the SuperStrypi rocket
http://spaceflightnow.com/2015/11/04/air-force-declares-failure-on-super-strypi-test-launch/
failed
early in the first stage burn. Not to speculate, but the
rocket did use a rail to launch. I'm thinking that they let
the launch lugs spin instead of having the fixed, this caused
a gyroscopic progression combined with the Corilolis effect
caused flow separation at the lugs resulting in unbalanced
mach cone development resulting in asymmetrical buffeting on
the fins causing flight instability resulting in failure....
If they ONLY would have kept the launch lugs from spinning
the failure could have been prevented...
Mike (nylon or Kevlar) Kramer
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