Hi All,
I have a 1995 C36 MKII. I just replaced its original Autohelm ST4000 with a new Raymarine kit: EV-1 sensor, Evolution 100 ACU, p70s control head and new wheel drive. I don't have any other items attached to the kit's N2K backbone.
Dockside calibration appeared to go okay. On my first outing, compass linearization was successful. With the autopilot engaged, its first minor heading correction resulted in a small overshoot. Its correction to the overshoot resulted in a larger overshoot. And, so on. Within 4 corrections, the wheel was turning aggressively and the boat was wagging its way out of the ICW channel I was in.
I reread the setup instructions and visited the Raymarine forum archives. There appeared to be two settings I could try to manipulate to stop the oscillations: Wheel Hard Over Time and Rudder Dampening. My timed Hard Over Time is ~14.8 seconds which, from a Raymarine forum post, I understand is outside of the normal 6-12 second range. I took the boat out for a second run yesterday. I first reran the dockside calibration. Did another compass linearization on the water and tried the AP. Same problem. I couldn't discern any improvement by shortening the Hard Over Time. Increasing Rudder Dampening to its maximum setting seemed to delay the occurence of the first course correction, but didn't reduce following oscillations.
Any helpful thoughts? Thanks, in advance
Dan
sv Hiatus
1995 C36MKII
Dan Cross
sv Hiatus
Sailing from Menominee, MI
1995 C36 MKII TR/SK M-35A(C)
There are a number of settings that need to be adjusted for the autopilot to work. Here is a list ti get you started from an older version of your pilot:
https://www.catalina36.org/members/encyclopedias/autopilot-settings-aka-...
Ron St. Onge
C36 MKII Hull 1384
Ron St. Onge
1995 Catalina 36 MKII Hull 1384
Do you have a rudder position sensor? If not then check the ACU firmware. I installed the same and found that the most recent ACU code "Corrects poor steering performance without a rudder refernce transducer". See the bottom of https://www.raymarine.eu/service-and-support/software-updates/autopilot/evolution-acu-all-variants.html.
I have a rudder position sensor so I didn't experience a problem.
Kyle Ewing
Donnybrook, 1990 Catalina 34 #1010
Belmont Harbor, Chicago
Thanks for your responses, gentlemen.
The dockside setup settings for the Evolution generation setup is different than those in the encyclopedia. The dockside setup has been "simplified" from the earlier SmartPilot and SPX systems.
I don't have a Rudder Position Sensor. After three calls to local certified repair shops, where the first question of each was "do you have a rudder position sensor?", I got the message. I ordered one today. And, I found Larry Brandt's good article on installing the sensor. The sensor may not be the full solution to my problem, but it may be a necessary component.
I don't have a Raymarine MFD, so I don't have the ability to update my firmware. I'll check my firmware version. I understand that the service guy I'm bringing in may be able to get the updates onto my devices.
I'll send updates as I progress. Thanks for the input,
Dan
Dan Cross
sv Hiatus
Sailing from Menominee, MI
1995 C36 MKII TR/SK M-35A(C)