Mega Rebel from Arkansas [Rocketarium] - Phase 1

Discussion in 'Oddrocs' started by Crawf56, Dec 21, 2019.

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  1. Jan 15, 2020 #61

    Crawf56

    Crawf56

    Crawf56

    Pig Soooiiieee!! TRF Supporter

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    Here is the Estes D12-3 motor from the launch, with a D12-5 for comparison.

    Note that chunks of the nozzle are gone. Not sure if that happened on impact with the ground.

    m_IMG_0699small.jpg

    m_IMG_0701small.jpg
     
  2. Jan 15, 2020 #62

    Crawf56

    Crawf56

    Crawf56

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    Looking at the ejection charge end of the motor.

    m_IMG_0700small.jpg

    m_IMG_0703small.jpg
     
  3. Jan 15, 2020 #63

    Crawf56

    Crawf56

    Crawf56

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    I still am not sure if this was a motor failure, or a construction failure. :confused: (I am leaning toward construction.)

    Will be ordering another engine mount from Apogee. The rebuild begins....;)
     
  4. Jan 19, 2020 #64

    Tobor

    Tobor

    Tobor

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    I have flown enough "D" motors since the 70's to know that your CATO event was due to the motor. I "think" what happened is the nozzle of the D12-3 had one or more fractures. When the motor ignited the thrust forced the fracture(s) to expand and then fragment. With a portion of the nozzle gone, all the characteristics of the motor burn changed, causing accelerated rate of burn and a much larger then normal exhaust plume.

    Alternatively, the fracture(s) could have been in the BP rather then the clay nozzle. But a fracture in the BP usually results in the motor case splitting open upon ignition.
     

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