R-5V flying model rocket

A civilian version of soviet R-5 medium-range nuclear missile in 1:25 scale. Requires at least some understanding of how model rockets fly — tiny fins at the bottom provide almost zero stability so you would have to fine-tune ballast in the nose. CG should be no further than 300mm from the tip of a nosecone, but adding too much weight drastically reduces apogee — good luck finding the perfect solution. On the test flight she went okay-ish with 80 grams of ballast in the nose even with some strong wind present.

Assembly instructions
1) Rocket body consists of the following parts: Tail, F1, F2_LONG (for those who have big printers)/F2_SHORT_1+F2_SHORT_2 (for those who have small ones), F3. F2 and F3 should be printed in vase mode, F1 — normal mode with 1 wall and 0 infill. Tail and F1, F1 and F2 are connected with part SPACER, F2 and F3 with SPACER_TOP. F3 serves as chute compartment. Inner tube is made out of cardboard and has 24mm outer diameter. If you are making F2 out of 2 parts, u