THE "P" MOTOR
This project started from incessant
badgering from Neil McGilvray and the rest of the MDRA Liberty Project
Team. We decided to lift the Liberty (more info can be found at:
http://www.mdrocketry.org/mgp.html) on a P and 2 O booster motors.
Since I had never done a P motor before, we decided to try it in Neil's
COW rocket first.
Of course, Jeff Taylor at
http://www.lokiresearch.com
made the casing, and it was a beauty! Threaded closures and a
gorgeous finish made the 40lb casing look military-grade.
Neil's cow rocket had already lofted on a
6" O motor, so the airframe was tested.
Jeff and I had some SERIOUS rocket science to do to get the design of
the motor to a state that we were comfortable with. We ended up
deciding to make the first flight a very low pressure flight. Our
original propellant was way to slow, so I ended up adding a bit of
Cupric Oxide to speed it up, hence the wonderful blue flame.
The motor is 6" in diameter, 6 grains
each 8" long. Total motor weight was right around 100lbs.
Sure enough, the button was pushed, and
the 20ft tall, 16" diameter, 400lb rocket pulled a VERY slow 6g's and cruised under power for 6
seconds, and then coasted to 6700ft. What a great accomplishment!
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P grain, O grain, 3" grain, 54mm grain, 38mm grain
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A 54mm grain INSIDE the core of the P motor grain
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6" P grain, 4.5" O grain, 3" M grain, 38mm grain
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Neil and a happy snap with the rocket
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The Cow lifts on P motor power
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The P motor at full thrust
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Here is an Quicktime movie of the cow, courtesy
of Chuck Rudy
Liftoff pictures courtesy of JerryO at
http:/www/vahpr.com
More pictures and videos to follow
