Adding an ejection charge to a D12-0

[Stefan2k4]

Speaking to the pressure produced on burn through of a BP motor, Estes once produced a model named "Cato". As the name suggests, it was designed to simulate an engine failure. Anyway, it flew on a C6-0 and the pressure released at burn through actuated a piston attached to a dowel which attached to a larger piston which ejected the nose and deployed the parachute. When the piston reached it's limit the motor mount tube was designed to detach and get kicked backwards releasing the segments the fins were attached to. Anyway, when the motor burnt through the pressure of that alone was used to separate the model into a half dozen pieces. Anyway, the point being, the pressure that is produced is greater than you might think and with the right engineering can certainly be used for deployment. My guess is that when a booster motor approaches the point of burn through, there is a point where the remaining forward "wall" of propellant grain is too thin to contain the pressure. When that happens, it probably shatters and exposes more surface area, which probably adds a bit to this pressure and produces a kind of psuedo "ejection charge" .