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Any reference to Raytheon or
RTN in this manual should be
interpreted as Raymarine.
The names Raytheon and RTN
are owned by the
Installation and Operating Handbook
The Autohelm 5000 is a modern high The basic system comprises a Drive Unit
performance autopilot specifically developed and Control Unit inter-connected by a
for sailing and motor vessels of up to 40'(13m) pluggable multi-core cable. A complete range
LOA. It is exceptionally easy to operate and its of optional remote control accessories are
advanced micro-electronic control circuit gives available which are also pluggable to the
outstanding steering performance. Control Unit. After fitting the system it is only
The Autohelm 5000 is distinguished by its necessary to make a single adjustment to the
automatic course locking capability which Control Unit in`,order to match the system's
permits change-over from manual to automatic response range to the character of a particular
steering by a single push-button control. From vessel.
then on the original heading is rigidly The Autohelm 5000 is exceptionally easy to
maintained by the automatic trim system which install and prepare for sea trials. Sound
continuously monitors trim changes and offsets installation however is vital if the system's high
the mean wheel position to compensate. In standard of performance and reliability is to be
addition, the rate of wheel rotation is regulated achieved. The installation notes should be
in proportion to the rate at which the vessel followed carefully and in cases where special
moves off course, giving the Autohelm 5000 the advice may be needed you are encouraged to
smooth steering capability of an experienced contact our Technical Sales Department where
helmsman. expert assistance is always available.
I .O SYSTEM DESCRIPTION
The Autohelm 5000 is a modular system A simple remote control installation is
that can be built up from a minimum number of illustrated in Fig. 2. The auxiliary control unit
standardised units to match the individual repeats the basic working controls of the main
requirements of a wide range of sailing and control unit and is suitable for extending
power vessels. The rudder drive system may be autopilot control to a secondary steering
chosen from a range of rotary, linear and position. Alternatively, in the case of a sailing
hydraulic drive units to best suit the vessel's yacht for example, the auxiliary control unit
particular steering system. provides a watertight cockpit control enabling
The most basic installation (Fig. 1) consists the control unit to be mounted in a protected
of a control unit inter-connected by a pluggable position below deck.
cable system to a drive unit. This installation The full remote control system (Fig. 3)
would be suitable for a motor vessel with a provides the addition of a hand-held remote
single enclosed steering position, and where no control unit.
requirement exists for remote control facilities.
Hand-held remote control unit type DO73 may
be plugged directly into the Control Unit
DRIVE UNIT CONTROL (D073)
CONTROL UNIT (OPTION)
.20 AMP FUSE
Fig. 1 Basic System
20 AMP FUSE
Fig. 2 Basic Remote Control System
f \ CONTROL UNIT
1 HAND HELD
REMOTE SOCKET m
D C SUPPLY
/ Ef /
Fig 3 Full Remote Contrd System
1 .l CONTROL SYSTEM
1.1 .l CONTROL UNIT
The control unit is common to all installations Rotary controls for course alteration, rudder
and is provided with six metres of multi-core response and sea state are grouped on the
cable with pre-connected plugs and sockets to control unit facia, together with the push-button
connect to the drive unit. It houses the main primary working controls. A secondary gain
control circuit PCB together with the automatic control is inset into the rear case to allow
course following compass system. The control adjustment of the system's rudder response
unit case is splash proof, but not watertight, and range to match the widely differing steering
is, therefore, intended for mounting in a dry and characteristics of both planing and
protected position. Two sockets are provided displacement vessels. The control unit is
on the rear case for connecting the drive unit suitable for use on 12 volt systems.
and remote control system.
142mm (5 VI
1 .1.2 REMOTE CONTROL
1 .I .3 AUXILIARY CONTROL UN IT
Autopilot control may be transferred to the
auxiliary control unit by depressing the Remote
push-button on the main control unit facia. The
auxiliary control unit is watertight and designed
for flush mounting in severely exposed
(3.2") 81 mm
It is provided with six metres of cable
terminated in a waterproof plug for direct
1 OOmm (3 9U
connection to the control unit. A connector is
situated on the rear case for connecting hand-
held remote control deck socket.
1 .1.4 REMOTE CONTROL UNITS
The remote control is a hand-held unit that
enables the autopilot to be overriden and the Auxiliary control Unit DO69 86mm (3 38")
vessel to be power steered from anywhere on
board. The unit is fitted with a six-metre flying
lead, Type DO73 is suitable for direct
connection to the Control Unit auxiliary socket. 35mm
Type DO93 is fitted with a waterproof plug for I1 38")
connection to a waterproof deck socket.
1.15 REMOTE SOCKET
The remote socket provides a watertight
socket for the hand-held remote control. The
socket is supplied with 6 metres of 3 core cable
terminating in a plugfor direct connection to
the Auxiliary Control Unit.
1 .1.6 CABLE EXTENSION
The cable extension facilitates the lengthening
of all multi-core cables in six-metre increments.
The extension cable is terminated with
compatible waterproof connectors for insertion
into the cable harness in the positions shown in
Fig. 3. Hand Held Remote Control Unit (D093t
Direct Remote Control (0073)
1 .I .7 CATALOGUE NUMBERS
Control Unit 2068
Auxiliary Control Unit DO69
Remote Control DO93
Direct Remote Control DO73
Remote Socket DO91
Cable Extension DO59
DRIVE SYSTEMS 12v only
Linear 2070 Remote Socket DO91
1.2 DRIVE SYSTEMS 1.2.1 ROTARY DRIVE UNIT
Mechanical steering systems may be driven by The output shaft is driven by a continuously
either a rotary or linear drive unit. Some steering rated servo motor via an efficient reduction
systems are fitted with an autopilot drive shaft, gearbox. The gearbox is dry lubricated to permit
and in such cases the choice of a rotary drive operation in any attitude. A fail safe friction
system is straightforward. In general, if a drive clutch within the gear train engages
shaft exists and lost motion does not exceed automatically when the autopilot is switched to
2% of total rudder movement, the rotary drive Duty and will disengage instantly even under
unit becomes the most economic choice. In all extreme load when the autopilot is switched
other cases the linear drive unit will provide the to Set.
simplest installation since it may be connected
directly to a tiller link on the rudder stock. Total Supply voltage 12 volts
independence of the mechanical steering Peak output torque 240lb.in. (27Nm)
linkage also allows the linear drive unit to be Maximum shaft speed 18 rpm
used to power steer the vessel in the event of Power consumption (typical 1 S-3 amps
steering linkage failure, and this is an important average)
safety feature. In addition, minimisation of Suitable for vessels up to 40ft. LOA (12m)
working parts improves the overall efficiency of
the rudder drive system and reduces lost
motion to an absolute minimum.
All vessels with hydraulic steering systems
will require a hydraulic drive unit.
2 Holes: 12Smm (0.5") diameter r - - - - i
1.2.2 LINEAR DRIVE UNIT
The output ram of the linear drive unit is driven Supply voltage 12 volts
by a declutchable re-circulating ball leadscrew Peak thrust 550lbs (225Kg)
which enables the drive unit to .be permanently Maximum stroke speed 1.2in./sec.
coupled to the rudder stock via a simple crank (30mm/sec.)
or tiller arm. The drive is automatically engaged Maximum stroke 12in. (300mm)
by means of an internal friction clutch when the
autopilot is switched to Duty and will Overall length at mid stroke 27.5in. (700mm)
disengage instaltly even under heavy load Tiller arm length 1 Oin. (260mm)
when the autopilot is switched to Set or Off. (+35" rudder)
Maximum rudder torque 500lb.in.
Power consumption (typical 1 Z-3 amps
25mm (1 .o") 207mm (6.15")
Suitable for vessels up to 40ft. LOA (12m)
51 mm (2.0")
_ ,- _
700mm lZ7.5") I
mm (0.7") RADIUS
1.2.3 HYDRAULIC DRIVE UNIT Supply voltage 12 volts
The hydraulic drive unit consists of a precision Regulated peak pressure 4501b.in2 (30 bar)
gear pump with integral valve block driven by a Flow control integral pilot
continuously rated servo motor. A special check and
pressure balance valve corrects the effects of pressure
hydraulic slip and isolates the pump from the balance valve
steering circuit when the autopilot is not sys tern
energised. Peak flow rate (unloaded) 40in3/mm
Maximum ram capacity 1 5in3 (25Occ)
, Power consumption (typical 2-3.5 amps
Overall length 9.5in. (240mm)
/L/ 240mm (9.5") 117mm (4.6")
The Atitohalm 5CCC is excepticnally easy tc essential to operate the autopilot via a weathsr-
install and prepare for sea trials. Sound proof auxiliary control unit. The auxiliary control
installation however is vital if the system's high unit would normally be mounted in the cockpit
standard of performance and reliability is to be adjacent to the steering position and the
achieved. The installation notes should be control unit situated below in a suitably
followed carefully and in cases where special protected position.
advice may be needed you are encouraged to The compass within the control unit is
contact our Technical Sales Department where capable of satisfactory operation at roll and
expert assistance is always available. pitch angles of up to -r-30 degrees. The control
unit should, therefore, be positioned as near to
horizontal as possible to maximise gimbal
2.1 CONTROL SYSTEM action in all directions. In the case of a sailing
yacht where sustained heel angles may on
2.1.1 CONTROL UNIT occasions exceed the above limit, it will be
The control unit is the most sensitive part of the necessary to readjust the control unit to a near
system and care should be taken to select a horizontal position on each tack. To faciliate
mounting position that is reasonably free from this, the control unit's suspension frame should
vibration and protected from external weather be mounted parallel to the direction of the heel
conditions. The control unit is mounted in an axis.
aluminium frame which can be pivoted to
permit fixing to either horizontal or vertical
surfaces. The frame is finally fixed into position 2.1.2 AUXILIARY CONTROL UNIT
by two No. 8 (4mm) diameter countersunk head The Auxiliary Control Unit is connected directly
stainless steel or brass screws. to the auxiliary connector on the Control Unit.
In the case of a vessel with an enclosed The unit is waterproof and should be positioned
wheelhouse, it would normally be desirable to close to the steering wheel. It is designed for
mount the control unit sufficiently near to the discreet flush mounting and a pattern is
wheel so that the controls are easily accessible provided to assist panel cutting before fitting.
to the helmsman. However, since the control Matching black self-tapping screws are
unit incorporates a magnetic compass it is provided to secure the auxiliary control unit
necessary to position it at least 2ft 6in (80cm) facia in position. A good quality silicone sealant
away from the nearest steering compass in should be used to seal between the facia and
.order to avoid devi&on Df both compasses. the mounting panel.
Deviation of the control unit compass is much
less critical because of its auto-following
capability. Nevertheless excessive deviation 2.1.3 HAND-HELD REMOTE'CONTROL
should be avoided as far as possible in order to
maintain uniform sensitivity on all headings. The SYSTEM
control unit should thus be mounted as far It is usually desirable to arrange for operation
away as possible from iron or other magnetic of the hand-held control unit from anywhere on
devices. If any doubt exists, the chosen site deck. For this purpose up to two remote
should be checked by means of a handbearing sockets may be strategically positioned to
compass. The handbearing compass should be make this practical without the need for long
fixed into the chosen position and the vessel and potentially hazardous flying leads on the
swung through 360 degrees. Relative hand-held unit. In the case of a sailing yacht for
differences in reading between the example, one socket position in the foredeck
handbearing compass and the main steering area and another in the cockpit usually makes
compass should not vary by more than 20 a perfect arrangement. The sockets are flush
degrees. mounted and a pattern is provided to simplify
In rare cases even the above extreme panel cutting. Matching black self-tapping
deviation tolerance may not be achievable, in screws are also supplied. A good quality
which case an alternative site remote from the silicone sealant should be used to seal the joint
steering position must be selected. In such a between the socket facia and the mounting
case it will be necessary to operate the face. When more than one remote control
autopilot through an auxiliary control unit socket is required, the three core inter-
situated near the steering position. Installation connecting cables may be paralled together
in steel hulled vessels invariably presents using a standard cable junction box before
difficulties and the advice of a compass connection to the Auxiliary Control Unit.
adjuster should always be sought.
Sarling yachts with a single external
steering position are a special case where it is
2.2 DRIVE SYSTEM
The following notes describe the installation of equally spaced caphead screws, and may be
both the rotary and linear drive units. rotated through 90 degrees to provide a more
convenient mounting position if required (Fig. 6)
2.2.1 ROTARY DRIVE UNIT tn some cases, it may be necessary to
fabricate a special frame to mount the drive
The rotary drive unit is coupled to the vessel's unit. It should be noted that chain tension can
steering mechanism by a simple chain drive. exceed 3OOlb (.l.50kg), and thus an extremely
Most steering gear manufacturers supply rigid mounting structure is vital to maintain
special autopilot drive attachments and many good chain alignment. Installation failures
include this facility as standard. frequently occur in this area, and as a general
Fig. 7 shows recommended rudder hardover rule it is desirable to `over engineer' the drive
to hardover times for both planing and unit mounting.
displacement vessels up to 42 feet (13m) LOA.
The charts shown in Fig. 8 enables the chain
reduction ratio for optimum rate of rudder 3.22-3.24mm
application to be selected for both planing and (0.127"-0 1275")
displacement vessels. To use the charts, it is 1
first necessary to determine the number of turns
of the driven sprocket when the rudder is driven
from hardover to hardover.
Example: 9 46-9 61 mm
A 40 foot (12m) LOA displacement vessel
requiring two turns of the driven sprocket to / /
drive the rudder from hardover to hardover will 19mm
require a chain reduction ratio of approximately (0.5")
3:l (as indicated by the dotted line on the
chart). The table on the left hand side of the Fig. 4
chart gives suitable sprocket combinations. In
this example, the required reduction ratio of 3:l
would be best achieved by a 38 tooth sprocket
driven by a 13 Mti.mcket on the drive unit.
It should be borne in mind that the
reduction ratios recommended are for the
`average case' and that vessels broadly
classified by length and hull type can vary
significantly in steering characteristics.
Selection of the correct chain reduction ratio is
not over critical however, and any slight
mismatch can usually be corrected later during
sea trials by an adjustment to the gain control
on the control unit.
Standard 3W' pitch chain is recommended
for the chain drive. Sprockets of 13, 15, 17, 19
and 25 teeth are available as standard
accessories. Bore and keyway dimensions for
the drive unit sprocket are detailed in Fig. 4. If
sprockets other than those supplied by
Nautech are fitted, it is essential that bore and
keyway dimensions specified in Fig. 4 are
strictly adhered to. The recommended driven
sprockets tabulated In Fig. 8 are common
standard sizes and should be obtainable from
local suppliers of chain drive equipment. All
sprockets must be "keyed" and grub screwed
to their shafts, and finally secured with `Loctite'.
The drive unit is mounted by bolting to a
substantial frame member (Fig. 5). The `1
shaped mounting foot is secured by four
Rrovision must also be r;;ade for chain
adjustment, which is most easily achieved by HARDOVER-HARDOVER
removable shims placed under the mounting TIME RECOMMENDATIONS
foot, or by elongated clearance holes in the
mounting frame as illustrated in Fig. 6. Both 40
sprockets must be accurately aligned to run in
the same plane, and this must be carefully 1
checked by means of a straight-edge.
The grease lubricated gearbox permits
mounting of the drive unit in any convenient
attitude without risk of oil leakage. The drive
unit's sprocket may also face any direction,
since steering sense can be corrected by
means of a phase switch located in the control
Finally, the chain should be tensioned until
it is `just' tight and contributes negligible lost
motion to the drive system. Total lost motion
between the driven sprocket attached to the
steering system and the rudder stock should .-
not exceed 2% of total movement. If lost motion .,
exceeds this level, it should be corrected,
otherwise steering performance will be
2.2.2 LINEAR DRIVE UNIT
The linear drive unit couples directly to the LINEAR DRIVE
rudder stock at the tiller arm length TILLER ARM LENGTHS
recommended in Fig. 9. It is usually INS CM
preferable to couple the linear drive unit to the
rudder stock via an independent tiller arm
`*- 3 0
(Edson offer a standard fitting). In certain cases,
however, it may be possible to couple the 1'- `._ .,
pushrod to the same tiller arm or rudder lI: *;L.-.yy
quadrant employed by the main steering
linkage. It is important to note that the linear
drive system can exert a thrust of 550lbs. If any
doubt exists about the strength of the existing
tiller arm or rudder quadrant the steering gear
manufacturer must be consulted. 5-
The method of bolting the pushrod ball end METRES
to the tiller arm or rudder quadrant is illustrated I I 1 1 I I
8 9 10 11 12 13
in Fig. 11. It is vitally important that the
coupling bolt is fully tightened and the nut I I I I
locked by means of the locking tab provided. 25 30 35 40
The standard ball end fitting will allow for a LOA
maximum angular misalignment between the
pushrod and the tiller crank plane of rotation of Fig. 9
up to 5". Accurate angular alignment is
extremely important and under no
circumstances should the above extreme limits
be exceeded. The body of the drive unit is
mounted by bolting to a substantial frame
member (Fig. 10). As a general rule it is
desirable to `over engineer' the linear drive
unit's mounting structure to ensure reliability
and maintenance of correct alignment. An
excessively fletibk mount can also severely
impair the steering performance of the
It is important to ensure that the total rudder
movement is limited by the rudder stops built
into the vessel rather than the end stops of the
linear drive output.
2.2.3 HYDRAULIC DRIVE UNIT
The hydraulic drive unitshould be mounted
clear of spraj/ and the possibility of immersion
in water. It should be located as near as
possible to the hydraulic steering cylinder. It is
important to bolt the hydraulic drive unit 222mm (8 7")
securely to a substantial member to avoid any
possibility of vibration that could damage the
The drive amplifier (Fig. 13) should be
mounted between the drive unit and the power
supply (batteries) in order to minimise the total
length of power cable. It should also be
mounted in a position clear of bilge water and
spray. The drive amplifier is mounted by first
removing the cover marked `Autohelm' and 8
bolting or screwing to a suitable vertical Fig. 13 Drive Amplifier
bulkhead through the four holes in the .base
CONTROL UNIT POWER SUPPLY CABLE
There are three basic types of hydraulic COiVfylECTlON SOCKET fve I
steering system (Fig. 12). Typical connection
points for the drive unit are shown in each case.
In all cases it is strongly recommended that
the steering gear manufacturer be
consulted. The drive unit valve block is tapped
l/4" BSP to accept suitable pipe fittings and
Dowty sealing washers are supplied (Fig. 15).
I DRIVE UNIT
EARTHING TERMINAL CONNECTION
Fig. 14 Drive Amplifier Wiring Diagram
Two Line System
Two Line .
Three Line System
Minimisation of hydraulic fluid loss during CONNECTION OF
connection of the drive unit will help to reduce. HYDRAULIC LINES TO PUMP
the time and effort required later to bleed the
system of trapped air. Absolute cleanliness is DOWTY SEAL
essential since even the smallest particle of
foreign matter could interfere with the correct ' BSP FITTING
function of precision check valves in the
When the installation has been completed
the hydraulic pump may be operated by
switching the control unit to Duty and operating
the Steer control. Greater motor movements will
be obtained if the gain control on the course
computer is set to No. 10 and the rudder Assembly for W' BSP Line Fitting
control set to maximum.
The hydraulic steering system should be Fig. 15
bled according to the manufacturer's DOWTY SEAL
instructions. From time to time during the
bleeding process the drive unit should be run #=%I `h" NPT FllTlNG
in both directions to clear trapped air from the
pump and inter-connecting pipe work.
If air is left in the system the steering will
feel spongy particularly when the wheel is
rotated to the hardover position. Trapped air will
severely impair correct operation of the
autopilot and the steering system and must be
removed. Assembly for l/d' NPT Line Fitting
During the installation of the system it has
not been necessary to keep track of the
connection sense to the hydraulic steering
circuit since operating sense of the autopilot
can be corrected if necessary by reversing the
polarity of* pump drive motor connections
(see section 3.3.1).
To check correct phasing of the_autopilot,
switch to Duty and rotate the Steer control
ii3 IN3 RECOMMENDED GAI N
clockwise. If phasing is correct starboard
rudder movement will result. If opposite rudder 50b 3 0 - CONTROL SETTINGS
movement occurs, reverse the phase switch
direction to correct as described in Section 3.2.
The gain control located on the back of the 5-
Control, Unit sets the rudder response of the
autopilot to match the particular installation.
The recommended gain control setting is given
in Fig. 16.
1 _#" __.ii.
I I I II " 11 1
1 2 3 4 5 6 7 8 9 1 0
GAIN CONTROL AVERAGE SE-tllNG
2.3 CABLING AND POWER SUPPLIES
2.3.1 SIGNAL CABLING
Cable inter-connections between system sub-
units are shown schematically in Figs. 1, 2, and
3. The interconnecting multi-core cable
between the control unit and drive unit is 20
feet (6m) long, and is supplied with the control
unit. All other interconnecting cables are
supplied with their related sub-unit and are also
20feet (6m) in length. All 7 core cables are
supplied with pre-wired waterproof connectors
and are extendable in 20 feet (6m) increments
by the addition of standard cable extensions
(Cat. No. 059) as shown in Fig. 3.
Cable connector clamp nuts should be
securely tightened to ensure watertight joints.
All cables should be run at least 3ft (1 m) from
existing cables carrying radio frequency or
pulsed signals, and should be clamped at 1.5
foot (05m) intervals.
2.3.2 DC SUPPLY CABLE
As a general rule the DC supply cable to the
drive unit should be kept as short as possible,
and have a conductor area of 1 .O sq.mm per
metre run to minimise voltage drop.
Length of cable Conductor area Cable size
Up to 2.5m 2.5 sq.mm 50/0.25mm
Upti4m 4 scpnm 56/0.3mm
The two supply cables must run directly from
the vessel's battery or alternatively from the
main distribution panel, and a 20 amp fuse or
overload trip should be included in the circuit.
It is important not to tap into supplies to other
into supplies to other equipment to avoid the
possibility of mutual interference.
The drive unit is supplied with 1.5ft (0.5m)
power supply cable tails. These should be
connected to the main power supply cable via
a heavy-duty terminal block. The red cable tail
should be connected to the positive supply and
the black cable to the negative supply. If
polarity is accidentally reversed the equipment
will not operate, but no damage will result.
The drive unit case must be bonded to the
metal hull or engine frame and a heavy duty
conductor (2.5mm2) should be used for this
3.1 BASIC PRINCIPLES
The following description of the Autohelm 5000 DUTY
principle of operation will help in providing a Push to fully energise the autopilot for
complete understanding of its controls. The automatic steering duty.
control unit houses an extremely sensitive auto-
setting electronic compass. When the autopilot REMOTE
is in operation, deviation from course is Push to transfer basic automatic pilot control to
continuously monitored by the compass and the auxiliary control unit.
corrective rudder is applied by the drive unit to
return the vessel to course. The amount of SEA
applied rudder is proportional to the course Rotate to adjust compass sensitivity to suit sea
error at any time, and thus when the original conditions. In position `0' the compass is fully
course is restored the rudder will be sensitised for operation in calm sea conditions.
neutralised. The amount of the rudder applied Clockwise rotation to position `7' progressively
for a given off-course error is adjustable to densensitises the compass for operation in
match both the steering characteristics of the rough sea conditions. Adjustment of this
vessel and speed through the water. A vessel important control is fully discussed later.
with a small rudder for example, will require
more corrective helm than a similar sized vessel R U D D E R
with a larger rudder. Similarly, a high speed Rotate to adjust rudder response. In position `0'
power boat will require considerably less rudder movement is minimised. Clockwise
corrective helm at planing speeds than it will at rotation to position `7' progressively increases
lower displacement speeds (Fig.1 8.) the amount of applied rudder. Adjustment
The characteristic which distinguishes the technique is fully discussed later.
Autohelm 5000 is its ability to make automatic
correction for changes in trim or weather helm. STEER
When changes in trim occur the set course can Rotate counter-clockwise or clockwise to alter
only be maintained by the application of course to port or starboard respectively. Each
permanent rudder offset to restore balance. scale division represents 5 degrees of course
Many automatic pilots are incapable of this and alteration. The steer control will rotate
will allow the vessel to bear on to a new automatically when the control unit is switched
heading to achieve a new state of balance. to Set.
Under these circumstances the Autoheim 5000 The controls on the rear case are used to
detects that the original course has not been adjust the auto-pilot's response to suit the
restored and will continue to apply additional particular installation and the vessel's steering
helm in the appropriate direction until the characteristics.
vessel returns to the original heading. This Each control has the following functions:
facility ensures that the originally set course is GAIN
held irrespective of changes in balance that Presets the overall system gain to compensate
may occur during the course of a passage. for variations in the mechanical reduction
between the drive unit and the rudder and the
vessel's steering characteristics. For initial sea
3.2 CONTROLS trial purposes this control is set according to
the recommendations given in Fig.1 8.
3.2.1 CONTROL UNIT
Fig.1 .I shows the position of all controls. Each PHASE SWITCH
control has the following functions: The phase switch is located on the internal
PCB and is accessible by removal of a blank
OFF rubber grommet from the rear case. The phase
Push to de-energise the autopilot. The electro- switch reverses the direction of corrective
magnetic clutch in the drive unit is disengaged rudder action and its setting procedure is
for manual steering. described later.
SET NB Recommended gain control settings for
Push to energise the compass circuit and hydraulic drive installations are given in
initiate the automatic compass setting the hydraulic drive unit instructions.
sequence. The compass is finally set to the
manually steered heading when both the red
and green pilot lights are extinguished.
GAIN DRIVE UNIT AUXILIARY
CONTROL SOCKET CONTROL SOCKET
Fig. 17 PHASE SWITCH / I I I I I 1
7 8 9 10 11 12 13
3.2.2 AUXILIARY CONTROL UNIT I I I I
25 30 35 40
Autopilot control may be transferred to the
auxiliary control unit (Fig.1 9) by depressing the
Remote push-button on the main control unit " ,,. _s., . I
facia. Fig. 18
Two independent rotary switches are
provided on the auxiliary control unit. The first I
permits Mange-over betweenSet and Duty
modes. The second control permits remote
alteration of heading. Switch movement to the
left or right initiates course alteration to port or
starboard respectively at approximately one
degree per second.
3.2.3 REMOTE CONTROL UNIT
The hand-held remote control unit (Fig.20)
enables the autopilot to be switched out and
the vessel to be power steered from anywhere
on board. Its flying lead may be plugged into .CONTROL WHEEL
any one of the remotely positioned waterproof
sockets and should be switched to Auto for
normal automatic steering operation. The
autopilot may be overriden by switching to
Manual and the vessel then power steered by
means of the control wheel. The automatic trim
system continues to operate in the manual
steering mode and a straight course will be
steered when the `boat' on the control wheel is
aligned with the remote control centre line. The
original course is remembered and will be
resumed immediately the change-over switch is
returned to Auto. If the vessel has been power
steered by the remote control for a long period
it is important to check that there is no chance
of collision when the original automatic
heading is acquired by switching back to Auto. Fig. 26
4.0 FUNCTIONAL TEST PROCEDURES
The following functional test procedure is 4.2 AUXILIARY CONTROL UNIT
recommended before attempting sea trials.
0 Switch the auxiliary control unit to Set and
then depress Remote on the main control
4.1 MAIN CONTROL UNIT unit. In this position the compass
0 Switch to Set and observe that the compass automatically sets to the present heading.
automatically sets to the present heading.
The Steer control will rotate while the 0 Switch the auxiliary control unit to Duty and
compass is setting and slow down as the check that.the drive unit clutch is engaged
null position is approached. When the by attempting to rotate the steering wheel.
compass is finally set both pilot lights will be
4.3 MECHANICAL TEST
0 Switch to Duty and check that the drive unit PROCEDURES
clutch is engaged by attempting to rotate
the steering wheel. Before attempting sea trials it is important to
verify that the vital link between the Autohelm
0 Adjust the Sea and Rudder controls to `0'. 5000 drive actuator and the vessel's steering
Then adjust the Steer control one or two system is free of obstruction and operating
divisions clockwise and then counter- correctly.
clockwise. The steering wheel should rotate It is strongly advised that the following
in the same direction as the Steer control. If simple checks are carried out.
opposite wheel rotation occurs, reverse the
phase switch. (A small screwdriver will be Warning
required to operate the phase switch after When the steering system is being moved
removal of the blank rubber grommet from manually or under drive from the actuator do
the rear case). not touch any part of the system, sprockets,
chains or limit stops. The forces exerted are
0 Increase Rudder control setting and note considerable and could cause injury.
that larger wheel movements result when the
Steer control is adjusted. Rotary Drive Unit
Locate the actuator and with an assistant to
.* Increase theSea control setting and note turn the main steering wheel switch on the pilot.
that larger movements of the Steer control
are necessary in either direction b.efore 0 Press Set - turn the steering wheel from
steering wheei movement commences. hardover to hardover. '
The automatic trimming capability of the 0 Ensure that the chain and sprockets driving
autopilot can be observed by the following test: the actuator move freely and in alignment.
Switch to Set to realign the compass. Then
switch to Duty and offset the Steer control by 0 Ensure that chain tension is adjusted
approximately two divisions i.e. approximately correctly (see 2.2.1)
10 degrees of heading change. This effectively
simulates a condition where the need for 0 Select Duty and rotate the Rudder control
standing helm has developed and the vessel is several turns to the right to drive the rudder
not returning to course. You will notice that after hardover.
an initial fixed helm has been applied the drive
unit continues to apply further helm movements, 0 When the actuator drives the rudder onto the
but at a much slower rate. If left in this condition mechanical limit stops ensure that the
the wheel will eventually rotate hardover. If, mounting of the drive actuator shows no
however, the vessel is moving through the water sign of movement.
the progressive application of additional helm
will eventually return the vessel to its original 0 Rotate the Rudder control in the opposite
course with the necessary standing helm direction to reverse the rudder drive to the
applied. This can be simulated by rotating the opposite end stop. Check for any movement.
steer control back to the original course
position. The progressive application of
standing helm will cease when the compass
senses that the original course has been
Linear Drive Unit Hydraulic System
0 Proceed as for rotary drive unit. 0 Proceed as for the rotary drive unit.
0 Check that at no point during movement of l Check that all unions are tight and there is
the steering quadrant and linear drive no seepage of hydraulic fluid.
actuator from hardover to hardover does the
actuator foul any part of the quadrant, l Select Duty and rotate the Rudder control
steering mechanism or yachts structure. Any several times to drive the rudder hardover.
fouling under load could damage the drive
actuator. l Rotate the Rudder control in the opposite
direction and drive the rudder hardover in
0 Check that the Drive actuator operates the opposite direction.
horizontally and that angular movement of
the ball end fitting is minimal (So maximum). 0 Check that the steering ram moves smoothly
and that there is no excessive play or
0 Select Duty and rotate the Rudder control jerkiness in the movement.
several times to drive the rudder hardover.
The performance of the Autohelm 5000 will
0 When the rudder is driven hardover check only reach the designed levels if the installation
that the mechanical limit stop on the of the actuator and steering system is correctly
vessel's steering system is reached before engineered and adjusted. It is strongly advised
the actuator reaches its mechanical limit. that these be checked before sea trials.
0 When the rudder drives hard against the end
stop check there is no visible movement of
the actuator mounting pedestal or the
structure supporting it.
0 Rotate the Rudder control in the opposite
direction and repeat the checks with the
rudder driven hardover inthe opposite
5.0 SEA TRIALS
Initial sea trials should be carried out in calm 0 When the autopilot is set to Duty return to
conditions and with plenty of sea room. The manual steering may be instantly achieved
previously conducted functional test will have by switching to Set or Off on the main
verified that the autopilot is operating correctly control unit. It is very important to remember
and that you are familiar with all of its controls. that manual control can only be obtained on
Check that the gain control on the rear of the auxiliary control unit if the main control
the control unit is adjusted to the setting unit is switched to Remote. The importance
recommended for the particular vessel category of being able to regain manual control of
given in Fig. 3.1, Then set the Sea control to `0' steering must-be stressed. The Off button is
and the Rudder control to `4'. coloured red for easy identification and
Initial sea trials on fast planing vessels manual take-over procedures should be
should be conducted at no more than half practised at an early stage.
engine throttle under which conditions the
recommended mid-way setting of the rudder 5.2 RUDDER CONTROL ADJUSTMENT
control should give acceptable steering
performance. A mid-way setting of the rudder The gain control on the rear of the control unit
control will also give acceptable steering has been previously set according to the
performance in sailing and displacement power recommendation given in Fig. 3.1. This control
vessels under all conditions for initial trial sets the range of adjustment available on the
purposes. Fine setting of the Rudder control is main panel Rudder control and in all but
discussed later. extreme cases should not need further
5.1 FIRST TRIALS In all cases, excessive rudder application
results in `oversteer' which can be recognised
.The following initial trial procedure is by the vessel swinging slowly from side to side
recommended: of the controlled heading. In addition, distinct
overshoot will be observed when the course is
0 Steer manually on to a fixed heading and changed. This extreme condition may be
hold the course steady. corrected by reducing the Rudder control
0 Switch the autopilot to Set and allow up to setting.
1.5 seconds for the compass to adjust Similarly, insufficient rudder application will
automatically to the manually steered result in sluggish steering response which is
: heading. particularly apparent when changing course
0 Switch to Duty and the autopilot will using the Steer control. This condition is
automatically take control. In calm corrected by increasing the Rudder control
conditions an extremely constant heading setting.
will be maintained. Oversteering and understeering tendencies
0 Increase the setting of the Sea control until are most easily recognised in calm sea
a good heading is achieved with a minimum conditions where wave action does not mask
number of wheel movements. Correct setting basic steering performance.
of this control for varying sea conditions is The operational adjustment technique for the
essential to avoid unnecessary wear and Rudder control varies significantly between
tear on the autopilot and to minimise planing and displacement craft and is ,
electrical power consumption. described separately below.
0 Alter course to port or starboard using the
Steer control on the main control unit, (or 5.2.1 PLANING CRAFT
the Left/Right control on the auxiliary
control unit with the main control unit Planing craft operate over a very large speed
switched to Remote). Major course range. Rudder effectiveness increases very
alterations are best applied by switching to significantly at higher hull speeds and it is thus
Set and then manually steering the vessel necessary to reduce the Rudder control setting
on to the new heading. When the new as speed increases to avoid oversteer. In
course is acquired, hold for a few seconds normal cases the rudder control setting would
and then switch the autopilot back to Duty be reduced almost to `0' at maximum planing
to maintain the new heading. speed and increased towards `7' at minimum
0 If a hand-held remote control is fitted, switch displacement speeds. Oversteer can be
from Auto to Manual and then power steer extremely violent at planing speeds and it is
the vessel by the control wheel. Switch back thus essential to reduce the rudder setting
to Auto and the vessel will return promptly before opening the throttle.
to the original heading.
5.2.2 DISPLACEMENT POWER
The Rudder control setting is much less critical
on this type of vessel and it is not normally
necessary to change the setting for different
engine speeds. As a general guide initial ._ . .
testing should be carried out at setting `4' and
reduced as much as possible `consistent with
good heading control to minimise wear and
tear on the steering `system.
5.2.3 SAILING CRAFT
Sailing craft average hull speeds do not vary
greatly and thus the Rudder control setting can
remain fixed most of the time. Initial testing
should be carried out at setting `4'. Sailing craft,
however, are particularly stable when sailing
close hauled and under these conditions it is
usually possible to reduce the Rudder control
setting to minimise rudder movement and
hence power consumption. Conversely, when
sailing down wind, directional stability is least,
and improved course holding will result from
increasing the rudder setting. The optimum
range of adjustment is easily found by
6.0 OPERATING HINTS
Unlike sailing yachts, power vessels do not It is also worth mentionina the more obvious
generally suffer with violent changes in trim, and that is that an autopilot cannot anticipate.
and thus, provided the operating instructions Sailing downwind in breaking seas needs
are carefully followed, extremely good course particular care.
holding performance will result in all weather One should avoid sailing under autopilot
conditions. when the wi`nd.is dead astern. Ideally, the wind
Sailing yachts are very different since in should be brought at least 30 degrees towards
gusting wind conditions violent changes in trim the beam, and in breaking seas it is often better
often occur. When a yacht is sailing badly out to remove the mainsail altogether and to sail
of balance, sudden gusts will generally cause it under boomed out headsail alone.
to luff violently to windward. When hand Providing you ensure that your vessel is
steering, the tendency is overcome by applying properly canvassed for the prevailing
sufficient weather helm to maintain the original conditions, your Autohelm 5000 will be capable
heading. The Autohelm 5000's automatic to sailing you through gale force winds.
weather helm compensation circuit however, is Moreover, it is at times like this that it will
intended only to take account of the gradual endear itself most of all by leaving you fresh
changes in standing helm that typically occur and alert to sail in safety.
when passage making due to changing wind Passage making under automatic pilot is a
conditions. wonderful experience that can easily lead you
When a sudden change in helm balance into the temptation of relaxing permanent
occurs the automatic compensation circuit will watch-keeping. This must be avoided however
take approximately one minute to restore the clear the sea ahead may appear to be.
original heading. In gusty conditions the course Remember, a large ship can cover two miles in
will tend to meander particularly if the sails are five minutes - just the time it takes to brew a
badly balanced. Significant improvement to cup of coffee!
course keeping can be obtained by ensuring
that sail balance is maintained.
Bear in mind the following important points.
: 0 00 notallow the yacht to heel excessive!y.
0 Ease the mainsheet traveller to leeward to
reduce heeling and weather helm.
0 If necessary reef the mainsail a little early.
7.0 ROUTINE MAINTENANCE
The autooilot is one of the most used and 3 Check that all inter-connecting cable sockets
hardest working items of equipment on board are fully tightened and free from corrosion.
and, therefore, must receive its fair share of 4 Check that external waterproof sockets are
attention and routine maintenance. The working capped when not in use and periodically
parts of the drive unit and the control unit are spray with WD40 (or similar) to protect from
sealed and lubricated for life during manufacture corrosion. ..
and do not need servicing 5 Check that the power supply cable
Regular inspection and routine maintenance connections are tight and free from
of the installation is recommended in the corrosion.
The Autohelm 5000 has an advanced micro-
1 Check tension and alignment of the drive electronic circuit requiring special equipment
chain and lubricate with a good quality and knowledge to service. In the unlikely event
waterproof light grease. of failure occuring in any part of the system you
2 Check for the development of excessive lost are advised to contact your nearest appointed
motion (backlash) in the steering gear and Service Agent who will provide you with
correct if necessary. Lost motion at the wheel competent and efficient service.
should not exceed 5% of the total wheel
movement from lock to lock.
Nautech Limited, Anchorage Park, Portsmouth
Hampshire PO3 5TD, England. Telephone (0705) 693611
Fax (0705) 694642, Telex 86384 NAUTEC G