Hirobo Bell UH-1B

Servo installation

Prior to the installation of the servos the servo tray is prepared. The remote glow plug is fitted first is close proximity to the plug. One terminal will be fitted to the engine mount and the other to the plug itself. A remote radio switch is also used, this will be just visible on the underside of the fuselage.

In order for the remote radio switch to operate a small hole is drilled in the servo base plate.

Five servos are used so that the collective pitch can operate independently from the throttle. The throttle servo is a standard economy servo with torque of 3.2 Kg/cm and a speed of 0.23 sec/60^0. The other four helicopter servos are identical with torque of 5.0 Kg/cm and a speed of 0.22 sec/60^0.

The servo floor is modified to accommodate nylon ties to secure the battery and receiver.

The battery is wrapped in a couple of layers of foam and held in place for a snug fit. The gyro is fixed in such a position so that the controls can be accessed through a window in the fuselage.

The receiver is situated in the remaining space, again wrapped in foam and held firmly in place by nylon ties.

The antenna is routed down a plastic pipe away from the mechanics. A couple of surplus ball links are attached to the lower side frame to support the antenna pipe.

The control push rods are assembled next. The aileron servo, which uses the large round servo horn, is designed to have ball joints at each end. However, the elevator, collective pitch, and throttle control rods included in the kit use an old fashioned Z bend. New rod lengths have been fabricated so that ball joints are used at each end.

The control set up is well detailed in the instruction manual and needs no further modification.

The installation of the throttle and collective pitch push rods completes the radio installation for now. The rudder servo will be set-up later when the mechanics are in the fuselage.

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