Just wanted to chime in here. The metals are the most expensive part of the turbine. I would think that the turbine side is using either inconnel or monel for the hot section and either aluminum or stainless for the compressor section.

The machining of these parts is tricky as well and more than likely done on a CNC machine with multi axis. Once programmed correctly the parts can be milled in a few hours.

A jet engine as simple as it seems is a very complex mechanism and with the RPM's they turn must be robust enough to handle the stress not only from heat but from vibration and centrifugal force. If inferior metals are used in it's construction the compressor side and turbine side are susceptible to creep. Basically what this does, is the blades tend to grow and will eventually contact the turbine or compressor case internally and will FOD the engine.

I don't know what China is using in their engines nor do I know what jetcat and others use. However the guys that have been around for awhile have a pretty decent track record. The jury is still out on the China product.

Profit aside for what the modeler is getting for around 2k to 5k is a bargain when it comes to model turbines.

On a business jet or airliner the minimum cost of 1 engine brand new is around $750,000 (Small turbine) and the last time I had to purchase an engine,a (CF-34 engine same one on the A-10 tank killer) that goes on a business jet (Challenger 601-605 models) cost around 2.5 million per side and cost anywhere from 250,000 to 1.2 million to overhaul.


Regards
Glenn Williams