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doing a nongap two stage rocket with a short booster, basically booster is length of the motor.
I am using a REAR thrust ring in the booster so the booster will not eject out the back, it’s minimum diameter 18mm motor, BT-20 tubing.
the motor will be recessed into the rear of the booster tube by 9 mm (1/2 body tube inside diameter.). The FORWARD end of the motor “nests” into the sustainer a corresponding 9 mm, so the sustainer motor will also be recessed 9 mm into the sustainer tube.
normally only 9 mm “nesting” would be borderline to act as a coupler, but since I am taping the motors together (I,e., no gap) I think the booster sustainer junction will be solid for the boost through upper stage ignition.
Both motors will be friction fit.
the sustainer has a coupler forward of the fin can that will be taped at launch, i can disconnect the Sections and shove the sustainer motor out from the inside with a dowel.
my understanding is that Krushnic Effect doesn’t kick until the motor is recessed greater than 1 body tube diameter.
so at 1/2 diameter, am I good?
I am using a REAR thrust ring in the booster so the booster will not eject out the back, it’s minimum diameter 18mm motor, BT-20 tubing.
the motor will be recessed into the rear of the booster tube by 9 mm (1/2 body tube inside diameter.). The FORWARD end of the motor “nests” into the sustainer a corresponding 9 mm, so the sustainer motor will also be recessed 9 mm into the sustainer tube.
normally only 9 mm “nesting” would be borderline to act as a coupler, but since I am taping the motors together (I,e., no gap) I think the booster sustainer junction will be solid for the boost through upper stage ignition.
Both motors will be friction fit.
the sustainer has a coupler forward of the fin can that will be taped at launch, i can disconnect the Sections and shove the sustainer motor out from the inside with a dowel.
my understanding is that Krushnic Effect doesn’t kick until the motor is recessed greater than 1 body tube diameter.
so at 1/2 diameter, am I good?