These folding propeller adapters are designed to be used in conjunction with TopModel XPower long shaft motors.This combination allows you to add a power system to a sailplane without the need for cutting the nose off of the fuselage. (See pics above). The adapters are machined from aluminum and have very precisely drilled motor shaft holes and are fastened to the motor shaft with set screws. The propellers are retained in the smaller yoke using countersunk threaded screws, while the large yoke, utilizes hardened steel pins retained with E-clips.
Links to the TopModel XPower long shaft motors can be found below.