This is a model of a rocket that I entered in a 3D-printed design contest at my job. If you do not want to use the provided model I recommend printing the fins using supports with the long side (hypotenuse) facing down. The infill should be less than 10% to save on weight. It should fit a “C” Estes rocket motor. The parachute only attaches to the payload section, but the motor section is fully reusable after free falling to the ground. Please reach out if you have any questions!