This is my third test
of this fuel in a 38mm motor. Test results from static test #2
indicated a better than "my" average ISP of 142.7. I
liked the numbers, but they seem way out of bounds, so another
test was conducted to prove, or disprove the first test results.
Attempt #3 was at a KN
of 313. Exactly the same as the previous test. I also used the new
ignition method on this motor. I cast a 3/8" slug of 65% KNO3 - 35%
Dextrose - 1% RIO fuel at the top of the forward grain. The motor came
up to pressure 1.5 seconds after the igniter fired. It was not as fast
as the last static test, but better than normal for the fuel.
The data from this firing was as follows
128.9 gram
of fuel fired in .75 seconds. There were 171.88 Newtons of total
thrust, and 214.83 Newtons of average thrust. As usual my test
stand was calibrated before firing. The ISP for this test was
135.98.
It looks like from a
performance stand point this fuel is a winner. It has some casting
characteristics that will make it undesirable for some people, but I am
willing to except them. Storage safety is still being evaluated and is
of some concern. My next step with this formula is to try and dial in a
better flame color and dim the brightness down a bit. Over all I am
pleased.
38mm x 112mm
static test 2-17-07
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