In addition, the rate of wheel rotation is regulated in proportion to the rate at which the vessel moves off course, giving the Autohelm 5000 the smooth steering capability of an experienced helmsman. The basic system comprises a Drive Unit and Control Unit inter-connected by a pluggable multi-core cable.
I .O SYSTEM DESCRIPTION The Autohelm 5000 is a modular system that can be built up from a minimum number of standardised units to match the individual requirements of a wide range of sailing and power vessels. The rudder drive system may be chosen from a range of rotary, linear and hydraulic drive units to best suit the vessel’s...
DRIVE UNIT 20 AMP F U S E SUPPLY System Fig 3 Full Remote Contrd 1 .l CONTROL SYSTEM 1.1 .l CONTROL UNIT The control unit is common to all installations and is provided with six metres of multi-core cable with pre-connected plugs and sockets to connect to the drive unit.
1 .1.2 REMOTE CONTROL ACCESSORIES 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 positions.
1.2 DRIVE SYSTEMS Mechanical steering systems may be driven by either a rotary or linear drive unit. Some steering systems are fitted with an autopilot drive shaft, and in such cases the choice of a rotary drive system is straightforward. In general, if a drive shaft exists and lost motion does not exceed 2% of total rudder movement, the rotary drive unit becomes the most economic choice.
1.2.2 LINEAR DRIVE UNIT The output ram of the linear drive unit is driven by a declutchable re-circulating ball leadscrew which enables the drive unit to .be permanently coupled to the rudder stock via a simple crank or tiller arm. The drive is automatically engaged by means of an internal friction clutch when the autopilot is switched to Duty and will disengage instaltly even under heavy load...
2.0 INSTALLATION The Atitohalm 5CCC is excepticnally easy tc install and prepare for sea trials. Sound installation however is vital if the system’s high standard of performance and reliability is to be achieved. The installation notes should be followed carefully and in cases where special advice may be needed you are encouraged to contact our Technical Sales Department where expert assistance is always available.
2.2 DRIVE SYSTEM The following notes describe the installation of both the rotary and linear drive units. 2.2.1 ROTARY DRIVE UNIT The rotary drive unit is coupled to the vessel’s steering mechanism by a simple chain drive. Most steering gear manufacturers supply special autopilot drive attachments and many include this facility as standard.
Rrovision must also be r;;ade for chain adjustment, which is most easily achieved by removable shims placed under the mounting foot, or by elongated clearance holes in the mounting frame as illustrated in Fig. 6. Both sprockets must be accurately aligned to run in the same plane, and this must be carefully checked by means of a straight-edge.
2.2.2 LINEAR DRIVE UNIT The linear drive unit couples directly to the rudder stock at the tiller arm length recommended in Fig. 9. It is usually preferable to couple the linear drive unit to the rudder stock via an independent tiller arm (Edson offer a standard fitting).
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 securely to a substantial member to avoid any possibility of vibration that could damage the inter-connecting pipework.
Minimisation of hydraulic fluid loss during connection of the drive unit will help to reduce. the time and effort required later to bleed the system of trapped air. Absolute cleanliness is essential since even the smallest particle of foreign matter could interfere with the correct function of precision check valves in the steering system.
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.
(Fig.1 8.) The characteristic which distinguishes the Autohelm 5000 is its ability to make automatic correction for changes in trim or weather helm. When changes in trim occur the set course can only be maintained by the application of permanent rudder offset to restore balance.
GAIN DRIVE UNIT CONTROL SOCKET Fig. 17 PHASE SWITCH 3.2.2 AUXILIARY CONTROL UNIT Autopilot control may be transferred to the auxiliary control unit (Fig.1 9) by depressing the Remote push-button on the main control unit facia. Two independent rotary switches are provided on the auxiliary control unit.
4.0 FUNCTIONAL TEST PROCEDURES The following functional test procedure is recommended before attempting sea trials. 4.1 MAIN CONTROL UNIT Switch to Set and observe that the compass automatically sets to the present heading. The Steer control will rotate while the compass is setting and slow down as the null position is approached.
0 Check that the steering ram moves smoothly and that there is no excessive play or jerkiness in the movement. The performance of the Autohelm 5000 will only reach the designed levels if the installation of the actuator and steering system is correctly engineered and adjusted.
TRIALS 5.0 SEA Initial sea trials should be carried out in calm conditions and with plenty of sea room. The previously conducted functional test will have verified that the autopilot is operating correctly and that you are familiar with all of its controls. Check that the gain control on the rear of the control unit is adjusted to the setting recommended for the particular vessel category...
5.2.2 DISPLACEMENT POWER VESSELS 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.
Providing you ensure that your vessel is properly canvassed for the prevailing conditions, your Autohelm 5000 will be capable to sailing you through gale force winds. Moreover, it is at times like this that it will endear itself most of all by leaving you fresh and alert to sail in safety.
5 Check that the power supply cable connections are tight and free from corrosion. The Autohelm 5000 has an advanced micro- electronic circuit requiring special equipment and knowledge to service. In the unlikely event of failure occuring in any part of the system you...