Well TBH this rocket is a design testbed for a rocket I have been thinking about since I was a kid. I moved to Colorado and was driving out near Hartsel (which is just down the road) and thought I have to get back into rocketry and design my masterpiece! Who new they launched HPR in Hartsel......
So Apogee is just down the road (along with Estes) and I got a copy of Rocksim and built my big bad super duper rocket. After some long hours of mixing and matching it is basically done. (3 stage with clustered first, E&F Black powder motors)
Rocksim says it will fly 5600ft and 600fps! But this brought some issues, first of which being I need a level 1 cert for 210grams of black powder.
Second of which is I want to see this rocket again so this means dual deployment from a BT-60 rocket, so this got me thinking about aft ejection for the drogue shoot but then there is the problem of drag separation......
So, I won't be ready to buy all the stuff I need for a level 1 cert before winter sets in up here at 9400ft, so I thought I would build a test rocket to work on the aft ejection issues. Aft ejection would seem silly in this rocket as front is so much easier but I would rather blow the side out of this rocket then my big one. So here I am. I need in this case to be able to eject the aft end without blowing up the rocket. (Assume it must overcome ~13 newtons of internal restraint against drag separation) This rocket will be 24mm Estes engines, but the big one will be 29mm. I am afraid if I don't deal with the ejection charge elegantly, that it will fail critically somewhere before it pushes the tail off the rocket (and drag on the released aft pulls the shoot out of its sealed container). So here we are at baffles and aluminum foil.......
Current design has the MM tube at 5.75 inches to allow for 2" of brillo at the top of the tube. 1" space from top of MM tube to bottom of baffle 2-3" of baffle and then entering a 1" space below the parachute container. (From top of MM tube to bottom of chute container is double walled) The rocket will separate at this space. I am not sure 4-5" in a BT-60 tube is enough room for those gases in that short amount of time before separation, so I was thinking of venting some out the bottom, but then this will be extra force I will have to overcome as it will work against separation.
Tinker