The diameter of the rocket engine tube is 18mm A, B, and C grade/ class engines are 18 mm in diameter but I will add a 24 mm rocket engine tube for D grade/ class engines( since there is wiggle room for bigger/smaller diameters ).

The outer layer of the model is 64mm for the 66mm body tube that you can buy anywhere. I will add outer layers to order body tube sizes. ( since there is wiggle room for bigger/smaller diameters ).

Requirements : Servo; SG90 or any servo with the same dimensions (may need to sand the edges of the 3d printed product) Pushrods;1mm servo pushrods or any type of 1mm metal wire Screws; (any type) that fits // can use any type of glue that works with your type of plastic PLA ( I used PBS pipe glue [not the best but ...] ) Servo Horn; (2*) M23-L??? just look at the pictures

NOTE: The design g will be improved over time. And extra components ts will be added. Did not try the model with the model rocket engine YET. I will add a video of the results and with the data, I will improve the design.

Good luck/