Efficiency is a pointless term in model aircraft, rc turbines are not efficient they just burn as much fuel as they can get. Electric systems are not much better.

As already said they cost $$$ yet for their output they actually produce more thrust than a P500 pro, and they are around 10k € for the fan unit and brushless controller.(https://www.mgm-compro.com/electric-propulsion-systems/)

There is a reason EDF run at high rpm, while gearing the unit will produce torque, at a certain speed the fan unit will act as a brake. Also printed blades will fail very quickly due to load and flex.

Here is a 400mm in igs you can easily modify and work with if you want.





In thrust we trust :-)

Regards,