CONTENTS General description 1 .o Control system 1 .l 1 .l .l Course computer Control units 1 .1.2 Fluxgate compass 1 .l .3 Windvane 1 .1 .4 Auxiliary alarm 1 .l .5 Radio navigation interface 1 .1.6 Drive systems Rotary drive unit 1.2.1 Linear drive unit 1.2.2...
1 .O GENERAL DESCRIPTION Autohelm 6000 is a modular automatic pilot system that can be built up to match the individual requirements of all types of sailing and power vessels. The rudder drive system may be selected from a range of rotary, linear and...
1 .I CONTROL SYSTEM 1 .I .l COURSE COMPUTER The course computer houses the central micro I computer and the drive system power amplifier which confines the complete electronic system to a single module. The course computer plugs into a connector unit to which all of the control system peripheral modules are connected.
.I .4 WINDVANE The windvane is designed for permanent attachment to the after rail where it can be sited in clear wind. The windvane interconnecting cable feeds through the deck via a waterproof gland unit and connects directly to the course computer connector unit.
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.
12.2 LINEAR DRIVE UNIT The output ram of the linear drive unit is driven by a declutchable recirculating 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 Supply voltage...
1.2.3 HYDRAULIC DRIVE UNIT The hydraulic drive unit consists of a precision _ gIsar pump with integral valve block driven by a continuously rated servo motor. A special pi’essure balance valve corrects the effects of h!/draulic slip and isolates the pump from the steering circuit when the autopilot is not energised.
INSTALLATION Installation of the Autohelm exceptionally straightforward but sound in:;tallation is vital if the system’s high standard of performance and reliability is to be achieved. 2.1 .l COURSE COMPUTER The course computer must be mounted in a protected position that is reasonably free of vibration, Since the power amplifier dissipates heat when the autopilot is under load, it is also important that the mounting position should be...
2.1.2 CONTROL UNITS Both the indicating and non indicating control units are designed for surface mounting in any position. Both are non magnetic and may be positioned near a steering compass if necessary. In all cases the control units should be placed within easy reach and view of the helmsman.
Installation Precautions Correct installation of the course computer and fluxgate compass is vital to the successful performance of the Autohelm 6000. The installation precautions must be heeded if poor performance or even failure of the autoprlot is to be avordect.
For use with the Autohelm 6000 this plug should be cut off and the cable threaded through the mast. The windvane head is then plugged into the top of the mast (Fig.
2.” 5 AUXILIARY ALARM Thl3 auxiliary alarm unit is waterproof and may therefore be mounted in any position. The alarm unit is supplied with a terminal block to connect a two core interconnection cable to the course computer. A 22mm hole should be bored through the mounting panel/deck to pass through the two way connector block and interconnecting cable (Fig.
2.2 DRIVE SYSTEM The following notes describe the installation of both the rotary, linear and hydraulic drive units. 2.2.1 ROTARY DRIVE UNIT The rotary drive unit is coupled to the steering mechanism by a simple chain drive. Most steering gear manufacturers supply special autopilot drive attachments and many include this facility as standard.
It should be borne in mind that the reduction ratios 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 cri,tical however, and any mismatch can be corrected during sea trials by an adjustment to the gain control switch on the course computer.
cases, it may be necessary to fabricate a special frame to mount the drive unit. It should be noted that chain tension can exceed 500lbs thus an extremely rigid mounting structure is vital to maintain good chain alignment. Installation failures frequently occur in this area and as a general rule, it is desirable to ‘over engineer’...
2.2.2 LINEAR DRIVE UNIT linear drive unit couples directly to the rudder stock at the tiller arm radius recommended in . Figs. 22 and 23. 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 unit should be mounted clear of spray 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.
2.3 CABLING AND POWER SUPPLIES 2.3.1 SIGNAL CABLING Cable interconnections between all sub system modules are shown schematically in (Fig. 1). All peripheral units connect to the connector unit where they are permanently hard wired to colour coded connector blocks situated on a central printed circuit board (Fig.
The total length of screened core cable connected to the serial bus (connectors Al - A5) should not exceed 30m (100’). Similarly, the total length of interconnecting cable to the fluxgate should not exceed 20m (60’). If it is necessary to exceed the above maximum length recommendations, please consult Nautech’s Engineering Department for specific advice.
3.0 OPERATION 3.1 BASIC PRINCIPLES The following description of the Autohelm principle of operation will help you to fully understand its controls. Deviation from course is continuously monitored by a sensitive fluxgate corrlactive rudder is applied by the drive unit to retuln the vessel to course.
3.2 CONTROLS 3.2.1 FIXED CONTROL UNITS I Both the indicating and non-indicating control units provide full control of the autopilot via a simple six button key pad and a rotary rudder control switch. The basic control functions are as follows:- STAND BY RUDDER ’...
3.2.2 HAND HELD CONTROL UNIT The hand held control unit provides remote proportional power steering of the vessel as well as full control of the autopilot. A safety interlock prevents use of the hand held control unit when the autopilot is disengaged by the helmsman. The basic control functions are as follows- MANUAL MANUAL AUTO...
3.2.3 WINDVANE SYSTEM When a windvane is fitted, a new layer of System control functions automatically opened on all control units as follows:- - 1 0 STAND BY Automatic Tacking The autopilot has an automatic tacking function which operates in windvane mode only as follows:- Push both red keys together once to...
X2.4 OPERATING MODE INDICATION AND COURSE DISPLAY l-he operating mode of the autopilot is indicated flashing red LED, or a flashing prefix letter on the course display as summarised below:- OPERATING MODE S-AND BY Autopilot switched on but not engaged AUTO Autopilot engaged to steer compass heading.
3.25 OFF-COURSE ALARM When the autopilot is set to either ‘Auto’ or ‘Vane’ mode a built in off-course alarm is automatically set up. The off-course alarm will sound from all control units when the vessel deviates for any reason from the original course by more than 15 degrees for over 10 seconds.
3.3 FUNCTIONAL TEST PROCEDURES The following functional tests and set up procedures must be carried out before sea trials al-e attempted. 3.3.1 SETTING UP Switch On Switch on the electrical supply from the main panel. All control units will emit a short beep tone to indicate that the computer is now active.
With the Autohelm 6000 in ‘Stand-by’ note the compass heading read by the indicating control unit at 30” increments on the Table below. Allow the vessel to stabilise on each heading for 15 seconds before noting the heading.
Check that the steering ram moves smoothly and that there is no excessive play or jerkiness in the movement. The performance of the Autohelm 6000 will only reach the designed levels if the installation of the actuator and steering system is correctly engineered and adjusted.
No adjustment of the pilot is necessary. After each course change the Automatic that Trim is cancelled and the Autohelm 6000 will reestablish the correct trim for the new heading. This process takes approximately one second per degree of course change. It should be noted that if a large course change is keyed in (greater than 60”) the pilot will not assume...
4.2 RUDDER CONTROL ADJUSTMENT The gain control switch on the course computer should have been set according to the recommendation given in section 3.3.1. control sets the range of adjustment available on the control unit rudder control switch and normally will not need further adjustment. Excessive rudder application results in ‘oversteer’...
- just the time it takes to make a cup of coffee! 5.1 UNSATISFACTORY STEERING PERFORMANCE lf the Autohelm 6000 has been correctly specified, installed in accordance with the instructions and adjusted correctly it will provide outstandingly good steering precision over a very wide range of wind and sea conditions.
5.2 PILOT FAILS TO DISENGAGE ON SELECTING STAND-BY The drive actuators of the Autohelm 6000 are designed to ‘Fail Safe’ - When power is disconnected the drive unit will always disengage leaving the steering system free for rnanual control. When Stand-by is selected the actuator will Disengage leaving the steering Free.
6.0 MAINTENANCE The autopilot is one of the most used and hardest working items Of equipment on board, and therefore fair share-of must receive its attention and maintenance. The working rOUthe parts of the drive svstem are sealed and lubricated for life during manufacture and therefore do not require servicing.
17.0 FAULT LOCATION PROCEDURE Autohelm 6000 has been designed to achieve very high standards of reliability combined with ease of servicing. If a fault should appear, please double check that all connections in the connector unit are sound and that the heavy power cable connections are tight and free from corrosion.
8. WARRANTY LIMITED WARRANTY Nautech or its appointed Distributors or Service Centres will, subject the conditions below, rectify any failures in this product due to faulty manufacture which become apparent within twelve months of its purchase date. Equipment used in the country of purchase should be sent directly to the authorised Distributor for that country or its appointed Service Centres.