rudder feedback unit

[Chinook Chaser]

Almost done installing a simrad ap24 helm drive autopilot on my islander. One last thing that remains is to calibrate the rudder feedback unit. To do this I need to be sure the rudder is centered perfectly. Other than just eye balling this how can I make sure this is centered? Maybe measure from each side of the boat to the lower unit with the lower unit all the way down. When measurement is the same on both sides in theory it should be centered. Any ideas or suggestions would be great. This is one of the few remaining things I need to get done before getting her in for the season!!
 

[guffins fisherman]

If the rudder is in the center of the boat, somehow run a string down the center line of the underside of your hull. I would say aligning the rudder with the center line of your hull would most likely give you the most accurate representation of straight ahead. IDK. Just a thought.

[lost a lure]

Turn the wheel from stop to stop and count the turns. Divide that in half and turn the wheel that many turns from one of the stops. Then eyeball the rudder.

Edited April 26, 2016 by lost a lure