Miniature gas turbines or scale jet engines

Many model engineers today are able to create or buy of the shelf the engineering feats of today as tiny working models. The idea of re-creating a powerful engine such as the jet has been dreams of many jet modellers since the very first full size engines were powered up by Hans von Ohain and Frank Whittle back in the 1930s.

How a real Jet Engine works!

Recreating small turbine engines to a different scale is not easy. Because of the square-cube law, the behaviour of many machines does not always scale up or down at the same rate as the machine's size (and often not even in a linear way), usually at best causing a dramatic loss of power or efficiency, and at worst causing them not to work at all. Kurt Schreckling, produced one of the world's first Micro-Turbines, the FD3/67.[1] This engine can produce up to 22 newtons of thrust, and can be built by most mechanically minded people with basic engineering tools, such as a metal lathe.
www.lerc.nasa.gov/WWW/K-12/airplane/bgp.html

A modern turbine JetCat 120SE

Kurt Schreckling (born 1939) is a German who pioneered home constructed turbojet engines for model aircraft. His design was constructed using hand tools, and has a wooden compressor and a bent metal gas turbine. It was fitted into a radio-controlled aircraft that flew successfully. Jet engines following his design are designated with a K, and J for Jesus Artes — his co developer for example 'KJ66'.  Ref (Wikipedia, the free encyclopedia)

Since then, various turbine manufactures have produced an increasing number of ready build and semi kits turbines all based on the schreckling/Artes design. Companies such as Jet Cat, Wren, Graupner, all provide various types of easy start turbines with a good selection of spares and service backup for the jet pilot who wants to get into the air quickly. The turbine used in a model will depend on the size, weight or even scale of the jet in question, usually a model with a good thrust to weight ratio, e.g. (1:1) will fly well. When choosing a turbine, you will be asked by the supplier "how much static thrust do you need your turbine to produce?" usually in pounds, e.g. a Jet cat SE120 turbine, with produce 28lb of static thrust, a jet model weighting 28lb will have a 1:1 ratio, therefore it should fly well, however if you are uncertain, do your research before you buy.