The old Raymarine ST4000+ autopilot is still working, even though we don't really trust in it for a longer passage any more. We decided to install a new below deck autopilot, but keep the old one as a backup system too.
We considered going for a Garmin Reactor 40 autopilot with a Class A drive as we have Garmin instruments and a standard NMEA2000 network on board, but unfortunately the Garmin autopilot is much more expensive and nowhere to be found (all stocks are out in Europe and US, and there is no promised date of delivery). So we went with the other option, a Raymarine EV-200 which we could get a good deal on and which is actually manufactured in Hungary, haha!
The installation of an autopilot is always tricky, as all boats are different and most out of the box systems require some customization.
The EV-200 consists of 5 elements:
- p70s Display
- ACU-200 controller
- EV Giro/Compass sensor
- Linear drive
- Rudder angle sensor
Placing the display and the ACU is straight forward as they can be placed without much restriction, but the sensor, linear drive and rudder angle sensor needs more consideration and preparation.
I decided to remove the old fish finder from the instrument panel console and place the new p70 display in it's place. As the plywood had to be re-made, I used this opportunity to optimize and reduce it's size. The new console became much narrower, allowing us to pass by going down the companionway.
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The ACU-200 has to be mounted vertically (to protect the connections from water ingress), we placed it in the technical compartment under the cockpit (engine room), on the aft bulkhead. It's a nice protected place and pretty close to the area where the linear drive will be installed.
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The EV sensor can be mounted off-center, and the bracket allows it to be mounted facing aft too, as the sensor can be rotated in it to point forward. The only requirement is that there should be no magnetic interference. I used a metal detector app on my phone and a handheld compass to find a suitable place, which for us was on the fore bulkhead of the technical compartment, next to the solar charge controller, above the diesel tank. It resulted in a deviation of only 2 degrees.
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The Linear drive was a tricky one. In theory it should be installed to have a grip directly on the rudder stock / steering quadrant which cannot be easily done on the Scanmar 35, as the locker where it's located is not deep/big enough. Our solution was inspired by another Scanmar 35 owner, who placed the drive in the locker between the aft locker and the technical compartment, where the rudder shaft goes through. This required some preparations.
First, I reinforced the bulkhead between the technical compartment and the aft locker by installing a 12mm mahogany plywood there, to double the thickness and spread the load. The plywood was coated with several layers of Epifanes varnish to protect it against moisture. The Linear drive got mounted on a custom made stainless steel bracket, that was through bolted on the bulkhead. The arm of the drive connects to the rudder pole with an off the shelf 32mm NOA fitting with an aluminium plate, that doesn't require any drilling or modification on the rudder shaft.
The stainless steel bracket was manufactured by a local smith workshop which took only a day and was reasonably priced.
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I drilled a hole in the aluminium NOA plate and installed the fitting for the autopilot on it. I also added a stainless steel plate on the bottom of it to reinforce it and installed to additional rubber clamps on both sides of the NOA fitting on the shaft, to make sure there is no slippage if the forces are stronger.
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The travel distance of the Linear drive is just right in this position, allowing a full rudder movement from port to starboard, without any additional stoppers needed.
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The rudder feedback sensor was installed on a small wooden base, that was epoxied in place. I decided to not drill into the rudder stock, but to glue on the fitting of the feedback sensor with a small blob of epoxy and some cable ties. Can decide later if drilling holes is really needed.
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All that was left is the cabling work. I was hoping to be able to connect the Raymarine autopilot to the existing NMEA 2000 network and use the data from the Garmin sensors.
Luckily this is now possible. The SeaTalk NG is basically an NMEA 2000 network, with proprietary connectors. Raymarine is now offering a converting cable, so the two backbones can be connected. The only thing I had to buy was the SeaTalk NG - NMEA 2000 backbone adapter cable and a blank plug for the one connector on the 4-way adapter that we left unused. The reason for leaving one connector unused is that after the two backbones are connected, there should be only one power-in source to the whole network and in our case that was already present on the NMEA 2000 side.
To my surprise, the whole thing worked without a problem. The p70 display powered on, found the EV sensor, the ACU-200, the Garmin Wind, Log, Depth sensor and the Garmin echoMap chartplotter. The chartplotter can use the heading data from the Raymarine EV sensor and the autopilot can use the Garmin Wind data to be able to work in a Wind Vane mode.
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The biggest surprise was that even the waypoint tracking feature is working. I can plot a course on the Garmin echoMap and the Raymarine EV-200 autopilot will receive the waypoints and follow the track. Perfect!
We calibrated the autopilot by running the dockside wizard and doing a sea trial and it was in use under our summer vacation of 4 weeks and so far everything worked very well. It's powerful, steers quietly and keeps the course very well.
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