AUTOHELM 1000 User manual

Installation and Operating Handbook
ANALOGUE
Autohelm 1000

The Autohelm 1000 is a highly developed autopilot
built to operate reliably in exposed marine
conditions. When correctly installed it will soon
become a vital crew-member giving many y
ears of
invaluable service.
The system has been designed for owner installation
and aided by the following installation guide,
fitting should prove to be a straightforward and
enjoyable job.
Cockpit and tiller configurations vary widely, and
thus in so
me cases special attachments may be
necessary to effect the neatest possible
installation. The attachments available and their
applications are fully described and are stocked
for immediate supply when required.
In cases where special advice is needed you
are
encouraged to contact our Technical Sales
Department who will be pleased to assist.

INSTALLATION

The basic actuator unit is a totally self-
contained
magnetic sensing automatic pilot. The autopilot is
mounted between the tiller and a single a
ttachment
point to the yacht's structure. After connection to
the yacht's 12 volt electrical system the unit
becomes operational.
Since the autopilot incorporates a magnetic sensing
device, it is advisable to ensure that the yacht's
steering compass is s
ituated at least 2'6” (750mm)
away to avoid deviation.
The actuator pushrod attaches to the tiller via a
ball-
ended pin situated 18” (460mm) radially
distant from the rudder stock or rudder pintle
centreline.
If the rudder pivot axis is sloping, the p
osition
of the ball-
ended pin must be positioned at a
radius of l8” (460mm) at 90 degrees to the axis of
rudder rotation as shown on the accompanying
illustration.
The autopilot slots into the bronze mounting socket
A provided, which should be permanantl
y fixed in
position. The mounting socket should be positioned
19” (480mm) to starboard
of the cockpit centreline
to ensure that port and starboard tiller movements
are equalised. It is also important to ensure that
the unit is positioned horizontally and as near as
possible to 90 degrees to the tiller when the
tiller is centralised.
4

Porthand mounting
In certain instances it may be more convenient to
mount the unit on the porthand side. The standard
unit is sensed to operate on the starboard side of
the tiller and where porthand mounting is required
a special porthand system must be ordered.
Porthand systems must be fitted with porthand wind
vane attachments.
Basic installation method
When the tiller is positioned low in the cockpit
and is adjust
able in height, the mounting socket
can be most conveniently positioned on the
starboard cockpit seat. The pushrod is attached to
the tiller via the standard ballpin provided which
is inserted directly into the top of the tiller.
The ballpin is installed by inserting it into a ¼”
(6mm) drilled hole and securing with a good quality
two pack epoxy adhesive such as Araldite. The
shoulder of the ballpin should be positioned ½”
(12.5mm) above the upper surface of the tiller to
avoid fouling when the pushrod is fully retracted.
The autopilot mounting socket is installed by
inserting it into a 1.2” (12.5mm) drilled hole and
permanently bonded with Araldite. It is important
to ensure that the mounting socket is securely
installed. If the mounting site, for example
,
consists only of a single glass fibre skin of less
thickness than the depth of the socket it will be
necessary to provide reinforcement by bonding a
plywood strengthening plate to the underside.
The autopilot is capable of generating very high
pushrod
loads and it must be stressed that in all
cases the mounting socket should be very firmly
bonded into position.
Extended pushrods
In some cases it may not be possible to provide a
convenient site for the mounting socket at the
standard mounting distance
of 19" (480mm). In such
cases the mounting distance can be increased in
increments of 1" (25mm) to a maximum of 6" (l5Omm)
with the use of special pushrod extensions. The
pushrod is extended by first unscrewing the pushrod
end cap and then screwing the pus
hrod extension
into position between the pushrod and the end cap.
This attachment is necessary, for example. When the
cockpit is unusually wide or when it is convenient
to mount the unit on the cockpit coaming.

5

Tiller attachments
When the till
er is not adjustable in height or is
positioned appreciably higher than the most
convenient site for the mounting socket. It is
often convenient to lower the ballpin underneath
the tiller. Standard tiller cranks are available in
a range of sizes to lower t
he ballpin centre in
increments of 1” (25mm) to a maximum of 5” (125mm)
below the underside of the tiller. Since the
pushrod centreline is positioned 2” (62mm) above
the mounting socket, these attachments can cater
for a vertical distance between the mount
ing socket
and the underside of the tiller of up to a maximum
of 7" (190mm). This attachment is particularly
useful-
in the case of transom hung rudder
configurations (such as the Folkboat) where the
tiller passes over an extended counter. In such
cases a tiller crank of suitable ballpin off-
set
will enable the unit to be neatly mounted directly
on the surface of the counter or the rear coaming.
The tiller crank attachments are bolted through the
centreline of the tiller, with ¼” (6mm) diameter
bolts and si
nce the bolts through the neutral
bending axis, the bending strength of the tiller
will not be significantly altered. The securing
bolts should be looked into the clearance holes
through the tiller with epoxy adhesive to ensure
that they do not work loose in operation.

6

Cantilever mounting
It may sometimes be necessary to attach the
autopilot to a vertical face such as the cockpit
sidewall. In this case, a special cantilever
mounting is available and is particularly
convenient when the tiller is pos
itioned
substantially higher than the level of the cockpit
seat. Full instructions are supplied with each
cantilever mounting kit. The standard cantilever
mounting kit allows the autopilot mounting socket
to be off-
set by a maximum of 10” (250mm) from the
vertical mounting face. This maximum dimension may
be reduced by cutting the cantilever to length
during installation. The cantilever screws into a
permanently mounted base which is bolted into
position by three ¼” (6mm) stainless steel bolts.
The cantilev
er may be unscrewed from its permanent
mounting base to allow unobstructed working space
when the autopilot is not in use.
Pedestal mounting
In certain cases it may be convenient to raise the
height of the autopilot mounting socket above the
cockpit seat
or counter for example. Standard
pedestal assemblies are available to raise the
mounting height from 1½” to 3½" above the mounting
surface in ½" (12.5mm) increments. The pedestal
base is bolted into position by three ¼” (6mm)
stainless steel bolts. When t
he autopilot is not in
use the pedestal may be unscrewed from its base to
allow clear working space when necessary.

7

Wind vane attachment
The wind vane attachment consists of two basic
modules –
the mounting mast which elevates the wind
vane into clear wind and the wind vane transducer
head which a
ttaches to the clevis at the head of
the mast by means of the cranked key provided. The
wind vane transducer is electrically connected to
the main autopilot unit by means of the waterproof
jack plug on the end of the interconnecting cable.
When the wind va
ne is not in use and the waterproof
plug is disconnected special care mist be taken to
ensure that the rubber blanking plug attached to
the socket on the main autopilot unit is firmly
pushed into position. If this is not done water
could enter the jack soc
ket and temporarily disable
the autopilot until the water is dried out.
Use of attachments
In very many cases the autopilot can be installed
without the need for special attachments. Where
this is no
t easily possible the above standard
attachments will normally provide a neat solution
and avoid the need for structural alterations. In
very rare cases where the standard range of
attachments do not provide a convenient mounting
arrangement it may be nece
ssary to consider the use
of purpose made attachments. In the event of
difficulties occurring, our Technical Sales
Department will be pleased to advise.
Battery connection
For trial purposes the actuator power lead may be
connected directly to the vessel
's 12 volt battery.
The brown lead should be connected to the positive
terminal and the blue lead to the negative
terminal. If the power connections are accidentally
reversed the autopilot will not function but no
damage will result.
It is recommended th
at a waterproof plug and socket
is situated adjacent to the unit and the power lead
shortened. A standard 5 amp fuse should be provided
in the power supply circuit to protect the internal
supply cable between the battery and the waterproof
outlet socket.
NB The equipment must not be connected to a battery
charger for testing.

8

Similarly when the jack plug is inserted in wet
cockpit conditions, extreme care should be taken to
ensure that the plug is kept dry. Occasional
lubrication of the jack plug
with Vaseline will
help to minimise problems of water intrusion. Once
the jack plug has been inserted, the connection is
absolutely watertight.
The wind vane transducer mounting mast is normally
clamped centrally to either a vertical or
horizontal rail o
f the after pulpit using the 'U'
clamps provided. In the event of an after pulpit
not being fitted the mounting flange may be bolted
directly to a suitable vertical face. Care must be
taken to ensure that the wind vane transducer is in
clear wind on both t
acks and not too close to the
deflected air stream from the mainsail. This is
normally ensured by situating the mounting mast
centrally behind the backstay and by elevating the
wind vane at least 2ft (60cm) above the highest
deck obstruction.
Feedback linkage
The autopilot operates on the principle of
mechanical feedback between the sensors and the
rudder to correlate corrective rudder action with
off course error.
To complete installation of the wind vane
attachment, the feedback drive cord emerging f
rom
the base of the mounting mast must be connected to
the pushrod. You will see that when the feedback
cord is pulled out of the mounting mast against
spring tension, backlash free rotational movement
of the wind vane transducer results.
Two small blocks
are provided for leading the
feedback cord to the tiller. Normally only one
block is necessary to obtain a clear run out but .
occasionally two blocks may be necessary to avoid
obstructions such as the mainsheet. The final
fairlead should be positioned aft
of the actuator
unit as shown so that the final run of the feedback
cord is orientated nearly at right angles to the
tiller. It is important that the final fairlead is
positioned below the centreline of the pushrod so
that the spring tension on the cord h
as a tendency
to pull the pushrod down onto the tiller pin.

Feedback Linkage 9

Finally, a loop is formed on the end of the
feedback cord after cutting to length and made fast
by means of the plastic adjustor slide provided.
The end of the loop is pos
itioned so that the
feedback cord is just under tension when attached
to the hook on the end of the pushrod in the fully
retracted position. This ensures that the feedback
cord is under tension over the full stroke of the
pushrod. If the feedback cord is o
ver tensioned,
the remaining free scope of movement may not be
sufficient to accommodate the full stroke of the
pushrod and may cause damage to the feedback
mechanism at the full extremity of pushrod travel.
After adjusting the cord tension as described
ab
ove, carefully check that the remaining scope of
feedback cord movement is sufficient to accommodate
the full stroke of the pushrod.
After rigging the feedback cord, check that the
wind vane transducer head rotates smoothly over the
full stroke of pushro
d movement. Backlash free vane
head movement is essential to ensure accurate
steering performance.

10

Operation
Functional test procedure
After completing the installation you should carry
out the following functional test to familiarise
yoursel
f with the system before attempting sea
trials.
The autopilot is fitted with a 4 position thumb
operated rotary switch located on the upper case.
The autopilot is switched off
when the thumb
control wheel is in the fully anti-
clockwise
position. The rema
ining 3 positions of the control
switch provide the following functions.
Calm
selects compass operation for 'calm' weather
conditions.
Rough
selects compass operation for 'rough' sea
conditions.
In this position minor yawing motions caused by
wave a
ction are neglected. The autopilot will
respond only to changes in mean course, and thus
the duty cycle and power consumption will be
substantially reduced.
Vane
selects wind vane control and enables convenient
transfer of control mode when the wind van
e
attachment is fitted.
Operation under compass control
•
Hold the unit towards the tiller and rotate the
compass dial until the cardinal point graduations
are approximately aligned with your main steering
compass.
•Switch to calm and note that the north g
raduation
on the compass dial then automatically homes to
magnetic north.
Main Control Switch

11

Rotate the compass dial in small increments until
the end of the pushrod remains settled over the
tiller pin and clutch onto the tiller. Rotate the
compass dial clockwise to retract the pushrod and
anti-
clockwise to extend it. Note that after making
adjustments, it is necessary to release the compass
dial to allow the compass to realign with the
earth's magnetic field.
If the yacht is swinging about
its mooring, you
will see that small variations in heading cause the
unit to apply corrective action to the rudder. Now
switch to rough
and note that the frequency of
corrective action is reduced.
Operation under wind vane control
If the system is fitt
ed with a wind vane attachment
the following familiarisation test may be carried
out.
•
Connect the wind vane jack plug to the main
actuator and attach the feedback cord to the end
of the pushrod.
•
Set the wind vane head into its most sensitive
position b
y tilting the head forward until the
vane is almost vertical. Then grip the mounting
mast just above its base and slowly rotate until
the vane feathers into wind. In this position the
vane will flutter evenly between the buffers.
•Switch over to vane to t
ransfer the sensing mode
to wind vane control.
Note that small variations in wind direction will
now cause the actuator unit to apply corrective
action to the rudder. This is how the Autohelm 1000
functions when under sail.
Rotate the mounting mast a li
ttle further and note
how the tiller takes up a new position to one side.
This is how trim corrections are made for weather
or lee helm when under sail.
Finally, tilt the vane head back until the vane is
nearly horizontal. This de-
sensitises the wind
va
ne, and you will note that the frequency of
corrective rudder action is noticeably reduced.
Operation under sail
Preferably, initial trials should be carried out in
reasonably calm conditions and with plenty of sea
room.
The following familiarisation pr
ocedure is
recommended.
Compass control
•
Steer onto a fixed heading under engine or sail
and hold the course steady.
•
Holding the pushrod towards the tiller, rotate
the compass dial until it is approximately
aligned with the yacht's main steering compas
s
and switch to calm.
•
Allow the compass to automatically align with the
earth's magnetic field and then adjust the
compass dial further until the end of the pushrod
is approximately positioned over the tiller pin.
•Clip the pushrod onto the tiller and a
llow the
autopilot to take over.