Tayana Vancouver 42 Aft Cockpit
Autopilot Details

Equipment

Hydraulic Ram: Octopus type 1212 LAM 12, doubled ended ram, bore 38 mm, stroke 305 mm, Displacement 345 cu cm.
			
Hydraulic pump: 	Octopus, piston type, Current 19A (peak), 6.8 A(average)
Tiller Arm:	Edison 10 inch,  machined to fit square section on top of ruuder shaft

Controller: 		Raymarine, Core pack X30
Compass: 		Raymarine Flux gate
Control Head: 		Raymarine ST8002,with display (rudder position etc)
Rudder feedback unit: 	Raymarine, rotary type 

Design Data
Ram Thrust (max) =	4000 N = 400 Kg force.
Rudder Torque Max = 	1000 N.m = 100 Kg.m
Rudder angle =		+/- 37  degrees
Rudder lock to lock	=	14 sec

Construction
Ram fitted to 19mm plywood board on starboard side of quadrant,

Plywood board is supported by two 50mm X 50 mm angle mounted transverse and bolted to rear end of cabin on port side. Note the rear wall of the cabin is conventently aligned being offset about 25 cm from the rudder shaft. Thus a 25 cm tiiler arm can be used with the ram operating at right angles to the arm with rudder in central position.
The rudder feedback unit is mounted on the bottom angle section and is attached to the quadrant by a parallelogram linage.
It is necessary to adjust the quadrant stops such that the ram does not bottem out.
The ram is fitted with a bypass valve and solenoid which is connected to the controler. 
The rudder

Performance
We have used the autoplolt for 30 months and travelled more than 2000 Nm in seas up to 4 m swell and wave.
The wheel movement is usually only about 6 inches wth the pump operating for a few seconds as each wave rolls past the yacht. Response level is normally at setting 3.

No addition force is fetlt on the wheel when the pilot is inactive.

The controller works best when steering to a compass course. In rough seas on sterring to a WP has too much rudder correction.

Steering close hauled has a limit of about 40 degrees apparent, but the controller is often too slow to correct foe large wave deflections