Raymarine autopilot + ST4000+ - Manual (Page 125)

110 ST4000+ Wheel & Tiller Autopilots: Owner’s Handbook
7
Custom
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ing t
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ST
4000+
AutoTrim (AUTOTRIM)
The AutoTrim setting determines the rate at which the autopilot
applies ‘standing helm’ to correct for trim changes caused by varying
wind loads on the sails or superstructure. The possible settings are:
The default setting (Level 3) should provide optimum performance
with the ST4000+ autopilot. However, depending on the boat’s
dynamic stability, an incorrect rate of trim application may result in
poor course keeping due to autopilot instability. After gaining
experience with the ST4000+, you may wish to change the setting.
You must evaluate the effect of the setting while under sail:
• decrease the AutoTrim level if the autopilot gives unstable course
keeping and the boat ‘snakes’ around the desired course
• increase the AutoTrim level if the autopilot hangs off course for
excessive periods of time
Drive type (DRIVE TYP)
The drive type setting controls how the autopilot drives the steering
system. Retain the default setting (DRIVE TYP 1) for mechanically
driven boats.
Magnetic variation (VARIATION)
If required, set this to the level of magnetic variation present at your
boat’s current position – indicated as east (E) or west (W). The
ST4000+ sends this variation setting to other instruments on the
SeaTalk system, and it can be updated by other SeaTalk instruments.
Setting Effect
Off No trim correction
1 Slow trim correction
2 Medium trim correction
3 Rapid trim correction
4 Very rapid correction