I just finished a Madcow 4 inch Nike Smoke and am getting prepared to launch it for the first time in a couple of weeks.
The loaded weight of this rocket will hover just above 7 pounds, so I really don't want anything to go wrong and destroy the rocket or anyone's property or worse.
I have plenty of experience with lighter, smaller diameter rockets and some with a Binder Excel and have no ejection failures to date on these bigger rockets. I would like to keep it that way.
I will be using AT 38mm I motors (for starters) with motor eject, as this is a single deploy rocket with no electronics, for now.
I have 217 cubic inches of space inside the rocket to pressurize, so the nose cone will eject and take my recovery gear with it. When I calculate the size of the expected ejection charge, should I take into account the space the parachute bundle and shock cord bundle take up in the airframe?
The calculators tell me I need about 1.5 grams of BP to create 14 psi of pressure inside the rocket, and since I will not be able to ground test, using motor eject, I want to make sure I use enough (more than enough) BP to get the job done. Up until now, I have followed the manufacturers guidelines for how much BP to use, but this time, I want to be doubly sure I am using enough.
Any help from those that have been where I am is greatly appreciated.
Steve
The loaded weight of this rocket will hover just above 7 pounds, so I really don't want anything to go wrong and destroy the rocket or anyone's property or worse.
I have plenty of experience with lighter, smaller diameter rockets and some with a Binder Excel and have no ejection failures to date on these bigger rockets. I would like to keep it that way.
I will be using AT 38mm I motors (for starters) with motor eject, as this is a single deploy rocket with no electronics, for now.
I have 217 cubic inches of space inside the rocket to pressurize, so the nose cone will eject and take my recovery gear with it. When I calculate the size of the expected ejection charge, should I take into account the space the parachute bundle and shock cord bundle take up in the airframe?
The calculators tell me I need about 1.5 grams of BP to create 14 psi of pressure inside the rocket, and since I will not be able to ground test, using motor eject, I want to make sure I use enough (more than enough) BP to get the job done. Up until now, I have followed the manufacturers guidelines for how much BP to use, but this time, I want to be doubly sure I am using enough.
Any help from those that have been where I am is greatly appreciated.
Steve