After some interesting questions arose during the previous test. I decided to test the T-2 motor using the prilled KNO3 propellant in a motor that was a known commodity. The T-2 did not have a port for taking a chamber pressure reading, so I could only record thrust.
Above is the chart of the T-2's thrust/time trace. This is exactly what I was expecting to see, and what I had hoped the new 2" motor's thrust curve would look like. This was a perfect burn, and the motor performed as expected.
Here are some numbers from the test:
Burn Time: 1.437 seconds
Propellant Weight: 1.03 lbs. (I accidentally cut the grains a little short, thus the lower than normal fuel weight)
Throat Diameter: .42"
Grains: 2) 1.5"x5.25", outside inhibited, core and ends burning.
Maximum Thrust: 228.25 Lbs.
Average Thrust: 87.375 Lbs.
Total Impulse: 125.5 Lb seconds
Isp: 121.8
There isn't a lot to be said. The motor falls in the strong "I" designation, as expected. The test stand worked great. I shot a video of the test, but it's not too interesting so I won't include it here. It does reconfirm my theory that the 2" motor is suffering from grain fracture do to a design flaw. The next test will be the 2" motor with grains cast in a paper liner.