| Rocksim pegged the CP about where the cone meets the tube.
80 grams of washers were required to move the CG 3" forward of that point.
The rocket was safety checked, and placed on the pad. When the
button was pushed, it went straight in the air maybe 75 feet, then began
sky-writing, crashing to the ground and breaking its back.
The post mortem conclusion was that 3" was not sufficient margin.
The laundry was not packed in and likely shifted under thrust, throwing
the rocket's CG aft and making it unstable. And the estimated CP
may have been off a little. It is, after all, an estimate.
2 calibers (6") would have likely resulted in a successful flight.
The nosecone has been recycled and flown on another rocket using the
same paper roll cores. Two neighborhood teens built it, and I sponsored
their successful flight on an Aerotech H Redline. |
