Dynon Avionics RV-9 Roll Kit User Manual
Page 4
DYNON AVIONICS
Servo Mounting Instructions – RV-9 Roll Kit
3
101046-004 Rev G
between it and the servo. Secure it to the upper bell crank support bracket using the
existing
fastener. Remove the necessary hardware in order to add the included linkage attach plate and
0.485" spacer using a combination of Dynon-supplied hardware, and existing hardware. With the
servo and bell crank additions in place, torque all fasteners back to original installation specifications
and add safety wire throughout.
With the servo installed, the linkage needs to be assembled. Refer to the illustration and follow
proper rod end installation techniques. Screw at least half of the threads on each rod end into the
push rod. To prevent the possibility of the servo arm going over-center, the servo arm
must not travel more than a total of +/-60º from neutral throughout the control system's range of
travel. The linkage geometry should be installed as close to the Dynon recommendation drawing as
possible. Dynon suggests installing the linkage at the middle hole of the servo arm. Changing this
location will affect servo torque output, servo arm travel, control surface resolution, and the amount
of force required to shear the safety screw, and should only be changed if the installer has an
understanding of these implications. See the diagram on the following page which illustrates the
linear travel and available force for each mount point on standard-arm servos.
Thread both large rod ends with jam nuts into the supplied 3.0" tube. Standard mounting of the
linkage to the servo arm will include the AN3H-10A bolt, AN970-3 large diameter flat washer (for
capturing the rod end bearing), 2 AN960-10 flat washers on each side of the servo arm itself, and
the AN365-1032A lock nut. The other end of the linkage will require the same type of stack-up, with
the addition of the 0.875" spacer and longer AN3H-17A bolt to secure to the drilled aileron bell
crank bracket.
The distance between the servo arm and the control system attachment point must allow for the
angle between the servo arm and the push rod to be at approximately 90º when the controls are at
neutral. Use the adjustability in the rod ends to achieve this, and then tighten the jam nuts to lock
the rod ends in place. Installers should always keep in mind the range of motion of the servo. Total
servo arm travel is limited, but verify that the arm and linkage do not interfere with anything during
the full motion of the control stick. The built-in control stops of the aircraft will limit the servo arm
travel when installed correctly. We recommend the use of the optional Range of Motion Limiting
Bracket, supplied with the servo to eliminate the chance of the servo arm going over-center. This
bracket should not be used as a normal stop; the aircraft's built-in stops should always be the
primary range limit.
Your servo(s) and AP74/76 (if ordered) came with a CD containing the latest documentation for all
Dynon products (also available a
Please read through that documentation to
understand the wiring and configuration process for your Autopilot system. We also maintain a
collaborative set of this documentation, which is often updated with new information by both
Dynon and fellow builders. Vis
to view and contribute to the latest
version of these documents.
You can also visit
to discuss and share installation notes, pictures, and
suggestions with other builders.
Neglecting to properly install and/or use Dynon autopilot hardware may
result in failures which could cause loss of aircraft control resulting in
aircraft damage, personal injury or death.