STEP 41-43 Rotor Head Linkages & Elevator Linkage
Step 43
The Elevator linkage is set up the same for both Helicopter and Airplane radios, the elevator pushrod
controls the tilt of the swashplate forward and backward which causes the helicopter to pitch forward or
backward ( hence fore-aft cyclic pitch ).
Use a servo horn in the shape of a cross and trim the 3 of the 4 arms off. Install one steel ball and
one 2mm nut at a distance of 10mm from the center of the servo ( mount the ball directly against the
bottom of the servo arm and tighten the nut on top, trim off the screw level with the nut to avoid
hitting the Aileron pushrods ), remember to use threadlock. With the radio on and the elevator trim set at
the center, attach the elevator pushrod (E) to the elevator bellcrank, then attach the servo horn at an angle of
10-15 degrees behind center of the servo ( the offset enables an equal throw of the swashplate). It is impor-
tant that the swashplate sit at 90 degrees to the main shaft.
Pushrod
A x 2
Pushrod
C x 2
Step 41
When attaching all pushrods, make sure
same length pushrods are actually the same
length from the beginning otherwise it will
be difficult later to figure out where the
linkage problems are coming from. The
entire rotor head is set up the same way for
both types of radios. Attach the two Pitch
Arm to Washout pushrods (A), the two
Bell Mixer to Inner Swashplate pushrods
(C) and the Aileron Bellcrank Swashplate
pushrods (J). Pushrod (I) was previously
installed in Step 4.
Pushrod B
Pushrod
F x 2
Pushrod E
Step 42
The lower linkages (helicopter radio)
are shown here to illustrate the
general setup and layout of the servo
linkages to the respective control
surfaces.
Pushrod J x 2
31
Pushrod
I x 2
Pushrod
G
Pushrod D or H
Note, for Airtronics servos, the ball needs to be installed on the top of the servo horn requiring the aileron servo to be moved up.
This can simply be done with 1/4” thick (6mm) spacer make from wood or plastic with the appropriate holes drilled.
