home made jet engine or remote controlled jet engine ( this actually was my graduation project) have a bunch of free online designs the most common is KJ66 the basic components of a model jet engines are the following :
1- a compressor wheel (which accelerate the income air entering the engine).
2- diffuser (it converts the high speed air into a high pressure air , rises its temperature)
3- combustion chamber (in where both air and fuel are mixed together forming a flammable mixture , then the mixture ignite producing a high speed and high temperature gases)
4- nozzle guide vane which guides the gases to hit the turbine wheel in a certain angle.
5- turbine wheel (both turbine and compressor wheel is coupled with a shaft) the turbine main function is to provide the necessary power to drive the compressor wheel.
6- the engine’s thrust is generated by applying a nozzle after the the turbine.