That's why the quality APs have a rudder position sensor. Good control
cannot be acheived without one.

DOug
s/v Callista

"Bruce in Alaska" wrote in message
...
In article k9elb.83730$sp2.44153@lakeread04,
Glenn Ashmore wrote:

Regular single ended double action cylinders have less
displacement on the rod side because of the volume of the rod. With a
constant pump speed it retracts faster than it extends and with less
force. You would never get an autopilot logic unit to control it
properly.

The above is NOT a correct statement considering that most AutoPilots use
an Electonic Feedback Loop for Rudder Position. This is accomplished by
having a Rudder Position Encoder mounted to the Rudder System that then
feeds back to the Pilot Logic directly. In this type of system, the
travel time of the Piston isn't even considered, unless the Hydrolic
Pump that feeds the system is so underrated that the movement of the
piston is slower than the Pulsewidth Modulation of the Feedback Loop.
All the AutoPilot OEM's I am familiar with take this into account when
designing the Feedback Loop in the first place, and therefor it is a
NONISSUE for the end user.

Bruce in alaska
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add a 2 before @