The field of Rocketry involves the development, construction, and launch of small-scale rockets, serving both educational purposes and competitions, and provides a field of study and practical application that allows the development of reduced-scale technologies simulating rocket behavior under controlled conditions. This work aims to present the design and manufacturing of an engine for mini-rockets with a 200 m apogee, used in the FRMF—Festival Regional de Minifoguetes. The research includes the idealization, modeling, and manufacturing of the rocket engine, utilizing tools such as experimental spreadsheets and computer-aided design (CAD) software, in addition to discussing the results obtained during the development process and the engine’s performance in the competition. The study focuses on the comparison between theoretical results, generated by simulation software, and practical results obtained from tests and during the competition. The structural design of an engine constitutes the starting point in mini-rocket development, being the most determining component for the vehicle's overall performance. This project seeks to integrate fundamental principles of physics, thermodynamics, and fluid mechanics into a compact and efficient system, with a special focus on safety, a critical aspect in rocketry. The adopted methodology was based on a pre-existing project from the literature, serving as a starting point for the adaptation and optimization of the engine. Dimensioning tables were used to simulate critical parameters, such as internal pressure and material resistance. The introduced modifications, such as replacing traditional screw fittings with threading, aim to increase practicality. The parts were manufactured from SAE 1020 steel, and stress analysis was performed using Autodesk Inventor software, employing the finite element method. Through the analyses obtained from burn test results and static bench tests, it was possible to improve safety and performance by adjusting critical parameters identified during testing. After implementing the changes and detailed data analysis, the rocket was successfully launched in the competition, reaching an apogee of 231 m, exceeding initial expectations. This work contributes not only as a practical guide for the manufacturing of mini-rocket engines but also as an in-depth analysis of the tools and techniques employed, evaluating their efficiency and impact on the development of small-scale aerospace projects.