so this factory replacement is a smart fix that restores smooth

1-72 screws are commonly used with HO through O scale couplers

Direct-fit factory replacement

Model / SKU : XRotor-15A / 30901100

straight feeder track with wires and rerailer

Hitec 31425CR HSR-1425CR Continuous Rotation DualBB Robot Servo N Bulidings so this factory replacement isHitec 31425CR HSR 1425CR Continuous Rotation DualBB Robot Servo This is the HSR 1425CR Continuous Rotation Robotic Servo from Hitec. FEATURES 360 continuous rotation Dual ball bearing equipped motor INCLUDES HSR 1425CR Robotic Servo with Hitec JR Z connector 0. 94" (24mm) diameter round horn four gromments, four eyelets and four 2x15mm mounting screws REQUIREMENTS Installing in robot and connecting to receiver and linkage SPECIFICATIONS Operating