This is a flying model rocket I designed in solidworks modeled from the brilliant TV accurate designer Lance Walton (his design is a 3d model but not a printable STL).

You will need to make your own motor mount as it depends on what size you decide to print your model. I scaled mine to the maximum size my Ender 5 Plus could handle, as such I ended up with a rocket that was over 17 inches tall...

I scaled it to accept a D or E engine size which is probably what you will need even if you print it with PolyPro like I did. I included a 24mm thread and retaining screw which should slide over a 24mm (E or D size) Estes Tube...(I apologize to the artist who made these, I could no longer find them on thingiverse) you can then make the retaining rings between the tube and the body depending on the size that you print at.

Fill the nosecone with as much clay and lead shot as required to move your center of gravity ahead of your centerpoint for launch...this will also vary depending on the material you choose, size, and how you print it (more or less infill). I did hollow out most of the internal structure, leaving enough to act as internal supports when printing...you should only need external supports.

UPDATE: Added a spot to tie the elastic to on the body that connects the chute and nosecone.

UPDATE: fixed an issue with the nosecone model that wasn't allowing it to slice properly

UPDATE: Since I did significant "lightening" of the model (hollowing out whole sections and adding internal supports so you don't need internal supports" I decided to print the latest version again. Printed in Braskem Polypropylene with Tree Supports touching build plate only...and it came out beautifully..and lighter than my original (easier to change the center of gravity to work).

UPDATE: Added a type E Estes threaded engine Mount which fits if you print the model at the size that I put it on here (full size). I printed it using the same Polypropylene and it fits an E type model rocket engine perfectly. This may be my last update before I launch it! I added a couple pictures of the latest print ready to launch!...in black stealth!