I also like to clean the main rotor and tail rotor shaft and lightly lubricate them with lube oil soaked tissue paper.
These low frequency spectrum lines are basically the harmonics of the rotor shaft frequency and the blade-passing frequency.
A rotor shaft is rotatably mounted at opposite end walls of the reactor and extends through the reactor coaxially with its longitudinal axis.
In addition, using a pair of strength shield which is connected with the flexible docking part can strengthen the bonding between the ear of the shaft and the rotor shaft.
