This adaptor implements a folding EDF (27mm inner diameter) for powering RC mini gliders. I made it for a "Multiplex Solius Mini" but it should fit in most any foamy glider of similar size.
The EDF pulls itself upright when power is applied and folds back into the fuselage by its own weight / cable pull when it is turned off - no extra servo needed. Total weight of my sample setup is 18g (adaptor + micro EDF) with a model AUW of 96g. Static thrust is about ~60g with a 27mm / 11000kV micro EDF @ 2S 200mAh Lipo battery.
I printed it PLA / solid.