Furuno NAVpilot-700, Installation Manual

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3. INITIAL SETTINGS
3-29
[ COUNT RUDDER ]: If the boat is heavily loaded, the heading could change excessively
because of inertia. This phenomenon causes the vessel to "overshoot" the intended
course. If this happens, the NAVpilot will steer the rudder to the opposite side and the
heading will turn in opposite direction excessively again. In an extreme case the heading
oscillates several times until it finally settles in the new course. An adjustment known as
"counter rudder" prevents this kind of oscillation.
Counter rudder is usually not required for small boats. When your boat zigzags a lot be-
fore settling in the new course, increase the counter rudder setting.
Trim gain
Note: [TRIM GAIN] is not shown in case of Fantum Feedback
TM
.
The NAVpilot continually monitors the boat's trim in order to keep the trim sensitivity opti-
mum. A lower setting is common because boat's trim usually does not change quickly. A
large number changes the trim compensation value more frequently. Too high of a setting
may result in the following problems.
• Trim sensitivity is over-affected, resulting that a trim appears in both port and starboard
directions alternately.
• Trim compensation mechanism responds to the yawing, resulting in more serious oscil-
lation of ship's heading.
To automatically set the trim, do as follows:
1. Rotate the knob to select [TRIM GAIN] from the [PARAMETER SETUP] menu.
2. Push the knob to show the options for [TRIM GAIN].
3. Rotate the knob to select [AUTO] or [MANUAL] then push the knob. For [AUTO] go to
step 4. For [MANUAL] do as follows:
1) Rotate the knob to select the current value and push the knob.
2) Rotate the knob to set a value (1 to 20, the default value is automatically calculated
according to length of your boat, entered on the [SHIP’S CHARACTERISTICS]
menu.
4. Push the knob to finish.
Intended
course
Large course error
The counter rudder feature functions to smoothly
return ship's heading toward intended course.
Counter rudder:
small setting
Counter rudder:
proper setting
Speed
Load Condition
COUNTER RUDDER
Slow
Light
Low
Fast
Heavy
High
MANUAL
AUTO