Great information. Thanks. I guess I did leave out considerable information, but I just wanted to confirm your statement that certain different components can be integrated? Yes?
So, my steering is by cable and pulley. So, if I find a liner drive unit I can put it on. Then get the other components separate?
Take some pictures of the current setup and post here.
The autopilot system consists of the following components
-Autopilot unit (the brain)
-A control head (operation panel)
-A rudder sensor(to give the "brain" info on rudder angle) Garmin has this integrated in the drive unit.
-A drive unit
The four first components are normally sold as a package - some packages also include the drive unit. Some kits also include some of the cabling (power cables is normally not part of the kit).
There are several types of drive units available (different makes and designs - just have a look at the different types Jefa make)
The autopilot unit have
-Two power cables (+/-) going to the drive unit, it changes direction by switching polarity
-A clutch output to operate the clutch on the drive unit
-Connection to control head, rudder sensor and compass
Depending on model it can also be integrated with chart plotter and wind instruments.
Also, can I mount the liner drive unit straight to the steering quadrant or do you have to have the rudder arm to shaft mechanism?
Depending on the quadrant it might be possible to attach the linear drive to the quadrant (you might have to reinforce the quadrant as most are not designed for loads from a linear drive)
A separate rudder arm is consider the best option as you get a system interdependent of the steering.
If you have a look at my post Upgrading the autopilot with a new linear drive
you can get some idea on how to measure for fit.
Also have a look at the jefa pages in my previous post.