Adjusting Autopilot Performance - Raymarine ST3000 Owner's Handbook Manual

Chapter 5: Commissioning the Wheel Pilot

5.3 Adjusting autopilot performance

The factory setting for rudder gain provides stable control for initial
sea trials. However, different boats can vary widely in their response
to the helm and further adjustment to the rudder gain may improve the
autopilot's steering characteristics.
The following test will determine whether the rudder gain is set too
high or too low.
1. In clear water and with the autopilot in Auto mode, alter course to
Note: It is easier to recognize these actions in calm sea conditions
where wave action does not mask basic steering performance.
starboard by 40° by pressing +10 four times.
• At cruising speeds, a course change of 40° should result in a
crisp turn followed by an overshoot of no more than 5°.
If this occurs the rudder gain is set correctly.
• If rudder gain is too high, the 40° course change will result in a
distinct overshoot of more than 5° ( A ).
Correct this oversteer by reducing the rudder gain setting.
• If rudder gain is too low, the boat's steering performance will
be sluggish – it will take a long time to make the 40° turn and
there will be no overshoot ( B ).
Correct this understeer by increasing the rudder gain setting.
Rudder gain
too low
New
heading
B
New
heading
Rudder gain
too high
Correct
rudder gain
59
A
New
heading
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