This is a recreation of the plastic parts used in this classic out-of-production Estes kit. This kit uses a novel detachable fin unit that can be removed for display and attached securely for flight. Break a fin and just replace the fin unit. The parts are specially designed to be easy to print without worrying about overhangs and support material. This means there are more parts than strictly necessary and some glue is required but it's all very straight-forward.
To build this kit you will need some standard model rocketry parts like BT-60 and BT-55 tubing, motor mount tube, recovery parts etc. Download the plans at:
You will follow these for most of the build. Note that part 030400 is BT-60 13.375" and part 030392 is BT-55 3.25". Refer to the exploded pictures included her for how to assemble the parts into the parts referenced in the kits. The nozzle_base, nozzle_bell, nozzle_plate and nozzle_tube go together to form the removable display nozzle. The fin_unit, motor_mount and motor_tube go together to form the removable fin unit for flight. The lock_ring and lock_collar go together and are glued to the BT-60 tube to provide the bayonet mount for the nozzle or fin unit.
There are two fin units included. One merely has slots for fins that you cut out of clear plastic sheet. The original fin units are crystal clear so they look invisible for flight. This is hard to achieve on the 3D printer so clear fin stock may be preferable.
These are old-school model rocket parts so they are sized in inches not in mm is is common. Make sure you import the parts for printing or scale accordingly.
The parts are designed to be printable without supports. They all lay nice and flat on the bed. Depending on your printer you may need to split the nose cone into two parts as it is rather long. There is some slip built into the designs for the parts that fit together but it's a good idea to make sure your printer is calibrated. i.e. tweak your extruder flow rate to make sure part dimensions are as accurate as possible for nice fits.