Old A/T reload kits, delays running really long

Discussion in 'Propulsion' started by byoungblood, Aug 23, 2017.

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  1. Aug 23, 2017 #1

    byoungblood

    byoungblood

    byoungblood

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    I bought a bunch of 24mm reloads from someone in my local club, and launched two of them this past weekend. In both cases, both delays ran long, one was very long, which led to one rocket almost lawn darting after it finally deployed about 100' or so off the ground. It was a 7 second delay that I drilled 2 seconds off using the Aerotech tool. Instead of the planned 5 second delay, it probably ran 8-9 seconds. The drilled end of the delay was facing downwards.

    The delay was bulged out on the ends and was more difficult than usual to install into the delay liner. Looking at the date codes on the kits, they're from 2004-2005. Best just to pitch the delays (propellant all seemed to be OK, they're all Blue Thunder) and buy new ones?
     
  2. Aug 23, 2017 #2

    dhbarr

    dhbarr

    dhbarr

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    Yes, or grab a cheap barometric altimeter.
     
  3. Aug 24, 2017 #3

    markkoelsch

    markkoelsch

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    Probably not uncommon. You may be able to buy new delay elements from Aerotech.
     
  4. Aug 25, 2017 #4

    Howie

    Howie

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    This past Sunday at our club launch a fairly new flier brought an assembled H128 motor. He bought it from someone in that state and it had been that way for some time. After disassembly and cleaning, the delay was heavily bulged. That was replaced as was the starter he owner never received. The propellant grains were lightly bulged and were carefully trimmed flat at both ends, taking care not to cut into the liner. The core of each was filed and the motor reassembled. It performed flawlessly.
     

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