Design and testing of an electromechanical engine for a small solid-propellant rocket using non-metal materials

Abstract

In this paper an engine prototype of 2 degrees of freedom from a work still in progress that helps a solid fuel rocket to stay vertical during motor operation is presented. One of the philosophies of this paper consists in using cheap and accessible materials, as well as avoiding the use of industrial machinery for its manufacture. This paper describes the procedure to generate solid fuel from a mixture of sugar and potassium nitrate. Subsequently, the design of the engine and tests conserning reusability with the prototype are presented. The design is based solely on obtaining the torques required to keep the prototype rocket moving in a vertical direction. The corresponding equations are written and after linearization, the transfer function is presented and the system is simulated using a PID control. The electromechanical system (ES) as well as the solid fuel motor were manufactured, and even though the ES is not coupled to the motor so the control actions are not evaluated, the performance of the rocket motor is measured using different design options and the propulsion times were evaluated. To measure the orientation and position the BMP280 and MPU6050 sensors were selected, and their stabilization time after turning them on was evaluated. It was found that the materials can be reused at least once for tests up to 23 grams of solid fuel, and that the selected electronic devices must have a stabilization time before ignition.