geof
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Ok, here's a scratch build using a 6" tube from my daughter's lava lamp packaging and a plastic lamp shade from another lamp. The fins are very light plywood; one of the key goals is to build something deceptively light.
Because the fins are relatively fragile and the nose will need some weight to keep the rocket stable, I decided to experiment with a form of rear ejection. The motor tube in this photo is 38mm, although I plan to step it down to 29mm and fly G & H motors. The other moon-shaped tube goes all the way through, adjacent to the motor tube the whole way. The plan is/was to glue a bulkhead somewhat above (11", to be exact) the forward end of this motor mount contraption. Then I would stuff a chute tightly in the moon-shaped compartment. Upon ejection, the pressure would push the chute out the back end. Then the rocket would land on its nose, protecting the fins.
I'm worried that inertia will cause the chute to "eject" at liftoff. I've considered this from the beginning, but as the build nears completion those nagging doubts are growing. What do you think? If I stuff the chute in very tightly (and maybe very tight dog barf below it), do you think it will be okay? If not, can you think of any method of retaining the chute during liftoff in a way that can be broken at ejection?
I have another idea that would use conventional ejection and run a line down the side of the rocket (and closing off the moon shaped tube), but that's aesthetically displeasing and breaks the experimental spirit I started with.
Any opinions/ideas?
Geof
Because the fins are relatively fragile and the nose will need some weight to keep the rocket stable, I decided to experiment with a form of rear ejection. The motor tube in this photo is 38mm, although I plan to step it down to 29mm and fly G & H motors. The other moon-shaped tube goes all the way through, adjacent to the motor tube the whole way. The plan is/was to glue a bulkhead somewhat above (11", to be exact) the forward end of this motor mount contraption. Then I would stuff a chute tightly in the moon-shaped compartment. Upon ejection, the pressure would push the chute out the back end. Then the rocket would land on its nose, protecting the fins.
I'm worried that inertia will cause the chute to "eject" at liftoff. I've considered this from the beginning, but as the build nears completion those nagging doubts are growing. What do you think? If I stuff the chute in very tightly (and maybe very tight dog barf below it), do you think it will be okay? If not, can you think of any method of retaining the chute during liftoff in a way that can be broken at ejection?
I have another idea that would use conventional ejection and run a line down the side of the rocket (and closing off the moon shaped tube), but that's aesthetically displeasing and breaks the experimental spirit I started with.
Any opinions/ideas?
Geof