Raymarine ST70+ Operating Manual

Also see for ST70 Instrument: Installation guide User reference guide User reference handbook Installation guide Operating guide

Contents

Raymarine ST70+ Operating Manual Manual pdf 53 page image

Chapter 2: Commissioning Procedures 45Checking rudder gainTo determine whether the rudder gain is set correctly, carry out the following test:1. Ensure you have set the autopilot response to level 5, as described above.2. Motor your boat at a typical cruising speed in clear water.It is easier to recognize the steering response in calm sea conditions where waveaction does not mask steering performance.3. Press AUTO to enter Auto mode, then alter course by 40°:• This course change should result in a crisp turn followed by an overshoot of nomore than 5°, If the rudder gain is adjusted correctly.• If the course change causes a distinct overshoot (more than 5°) and/or there isa distinct ‘S’ in the course (as at A in Figure 2-3), the rudder gain is too high.• If the boat’s performance is sluggish and it takes a long time to make the 40°turn, with no overshoot (as at B in Figure 2-3), the rudder gain is too low.Figure 2-3: The affect of different rudder gain valuesIf necessary, use the Setting rudder gain procedure in Chapter 3:Setup Information toimprove autopilot performance.Checking counter rudderTo check the counter rudder setting:1. Ensure you have set the response to level 5, as described above.2. Motor your boat at cruising speed in clear water.3. Press AUTO to switch the autopilot to Auto mode, then make a 90° course change:• When rudder gain and counter rudder are both set correctly, the boat performsa smooth continuous turn with minimal overshoot.• If the counter rudder is too low, the boat will still overshoot.• If counter rudder is too high, the boat will ‘fight’ the turn and make a series ofshort, sharp turns. This results in a very ‘mechanical’ feel as the boat changescourse.If necessary, use the Setting counter rudder procedure in Chapter 3:SetupInformation to improve autopilot performance.NewheadingCorrectrudder gainD11622-1NewheadingBRudder gaintoo lowNewheadingARudder gaintoo high