Author Topic: Super Astron Cobra - when one motor isn't enough  (Read 9981 times)

Offline RickB

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Re: Super Astron Cobra - when one motor isn't enough
« Reply #15 on: May 02, 2016, 02:43:52 PM »
That's a great paint job on your upscaled Cobra Rick!
Can't wait to see it fly!
Greg
Thanks, Greg.  I expect this will be a Potter-only (non-Geneseo) flyer...
Rick Barnes

Offline RickB

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Re: Super Astron Cobra - when one motor isn't enough
« Reply #16 on: May 02, 2016, 02:46:45 PM »
Don't forget to cover the tops of the ejection charges of the BP motors with a piece of masking tape just in case all 3 motors do not ignite on launch.  There is always a chance that if one does not ignite on lift-off, the heat of the ejection charges from the other motors can cause the unignited motor to burn backwards, and that can ruin your day.

Bob
Interesting though, Bob.  I hadn't considered that will previous clustered rockets.  How, though, would the ejection charge of one motor light the top of a previous unburned motor, it there's a clay cap at the top of that motor?  Am I missing something?  It seems like the cap would provide better protection than a piece of tape...
Rick Barnes

Offline Bob Krech

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Re: Super Astron Cobra - when one motor isn't enough
« Reply #17 on: May 02, 2016, 04:39:21 PM »
It normally does, but a small fraction of the motors can have a thin or porous clay cap and therein lies the problem.

Bob

Offline Greg Young

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Re: Super Astron Cobra - when one motor isn't enough
« Reply #18 on: May 03, 2016, 08:21:31 AM »
Don't forget to cover the tops of the ejection charges of the BP motors with a piece of masking tape just in case all 3 motors do not ignite on launch.  There is always a chance that if one does not ignite on lift-off, the heat of the ejection charges from the other motors can cause the unignited motor to burn backwards, and that can ruin your day.

Bob

.. not to mention your rocket! :)

Offline Larry Weibert

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Re: Super Astron Cobra - when one motor isn't enough
« Reply #19 on: May 18, 2016, 10:37:11 PM »
Some things in life you just don't think about till someone tells you. That is a great tip thanks Bob
MRSI,TRA,NAR,URRG

Offline RickB

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Re: Super Astron Cobra - when one motor isn't enough
« Reply #20 on: June 27, 2016, 02:17:47 PM »
I finally made the first flight of this rocket on Saturday at URRF3, when the winds were relatively calm.  All three E16-6 motors lit (after multiple continuity checks on black-tip ignitors), and it made a good flight.  The only issue was that my altimeter didn't get a good reading; I'm still learning to use it properly.  However, the Chute Release did it's thing, and it landed close by.  I was able to set it up on the pad just before going on duty as Low Power manager, so I was able to watch it launch fairly up close.  The landing was within the low power pad area as well.  I'll post some photos once I upload them all to flicker...
Rick Barnes

Offline RickB

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Re: Super Astron Cobra - when one motor isn't enough
« Reply #21 on: June 29, 2016, 12:50:39 PM »
I finally made the first flight of this rocket on Saturday at URRF3, when the winds were relatively calm.  All three E16-6 motors lit (after multiple continuity checks on black-tip ignitors), and it made a good flight.  The only issue was that my altimeter didn't get a good reading; I'm still learning to use it properly.  However, the Chute Release did it's thing, and it landed close by.  I was able to set it up on the pad just before going on duty as Low Power manager, so I was able to watch it launch fairly up close.  The landing was within the low power pad area as well.  I'll post some photos once I upload them all to flicker...
First flight photos:





Rick Barnes

Offline RKeller

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Re: Super Astron Cobra - when one motor isn't enough
« Reply #22 on: June 29, 2016, 12:57:40 PM »
love that last shot! very cool flight Rick!
Riley Keller
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L1 25 Oct 2014 Estes MDRM CTI H133
L2 25 June 2015 Rocketry Warehouse DYOK, CTI L1030RL 14.7k ft mach 1.57

I'm addicted to building stuff, rockets are just a way to get high