Sunday, March 27, 2005

A Wheel Pilot on an OI41?

 Posted by Hello

We have successfully installed a RayMarine ST4000+ Wheel Pilot onto a Morgan Out Island 41. It's not really rated for such a large boat, but it is working great.

Update: I received a question on how it works since the Out Island displaces much more than the specs for the ST4000+ and here was my reply:

I am a firm believer that I will need a proper below-decks autopilot system that is tied directly into my OI41's hydraulic system -- eventually. I also have first hand experience that autopilots can break down on long trips and you should have a backup. Based on circumstance, I have decided to install the backup first, then later put in the proper (and expensive) hydraulic system. In a couple of years I will look at either Raymarine or SimRad (formerly Robertson).

I had the Raymarine ST4000+ wheel pilot sitting in my garage. When I bought the boat I learned it didn't fit without using a hole saw so I put it away. The ST4000+ had worked great on my last boat which displaced about 14,000 lbs. loaded, had a chain drive wheel/rudder assembly that was way out of balance. If I let go of the wheel it pulled hard to starboard whether under power or sail and took a bit of over correcting to keep the boat on line. The OI416 is very well balanced. The hydraulic steering does not take much torque to turn the wheel at all.

I don't completely understand the guidelines for displacement and autopilots once you move to hydraulic steering. My ten year old son struggled to man the helm on the last boat, and is totally bored at the helm of the Morgan because there isn't much to do.

So I went ahead, took a deep breath, and cut a 2.5" hole into my helm and installed the ST4000. It turns out it works pretty great. I have it talking to my Garmin 182C chart plotter via NMEA. I can plot a course on the Garmin and each leg gets sent to the ST4000 and it stays on course. Our main test so far was a trip across Tampa Bay a couple of weeks ago. We were on a run to a broad reach, about 16-18 knot winds with 2 to 2.5' trailing seas sailing just Jib and Mizzen sails. She kept course just fine.

The tweaking part I referred to is really just trying different software settings for sensitivity, course correction and how hard you have to turn the wheel to turn the boat effectively. Ironically, the best settings turned out to be the factory defaults whereas the ST4000 still remembered the old boat settings. I spent a few hours playing with the software settings as we sailed across the bay to find this out.

One note about sea state. The ST4000+ has a feature that "learns" as you go so that it reduces the amount of corrections, particularly on a following sea. This feature was turned off for the last boat because the less the pilot tried to work, the more prone I was to turning in circles. Once we turned it on during our run across the bay it did an especially good job of keeping us on course with a minimum of course corrections on my beautifully balanced Morgan. But I'm only basing this on a three hour trip in relatively light seas.

Would I do it this way if I didn't already own the ST4000? No. I would spend the $3,500 and get the proper below decks hydraulic unit for a several reasons. 1. My wheel would not have a contraption bolted onto it. 2. With a belt pilot or wheel pilot the motor makes noise when turning the wheel. With the hydraulic system the wheel doesn't even turn while steering the boat. 3. The electronics and software in the new packages are really good now, especially in trailing seas.

That said, total new parts I needed for the installation came to a little under $200 most of which was $170 for the back box for the control unit. And it works very well.


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