I decided it’s finally time to add an autopilot this year. I had been holding off while trying to figure out how to install a below deck unit without spending thousands of dollars, and concluded that it probably wouldn’t ever happen. So I decided to go with a tiller pilot, and after much research on the pros and cons of the Simrad and the Raymarine units, I eventually concluded that the Raymarine tiller pilot was the better choice, primarily based on the number of failures that people had reported of the Simrad units from very small amounts of rain or spray getting on them was far higher than the same number of issues reported on the Raymarine units. I also opted for the larger, ST2000+ unit instead of the ST1000+ since it has the faster hard over time, and the more robust drive unit. Also I still have a couple thoughts about how I may one day convert it to a semi permanent below deck unit, and the extra power would be needed. Check back here in another year or two to see if that idea ever pans out.
I started by determining the location to install the connector and perform drill the holes. I opted to have everything near the engine controls where I could operate, connect and control everything from one spot, so I installed the connector almost directly below the ignition key for the engine.
Just about the whole autopilot project was done in parallel with the fuel system upgrade so I was able to plan the location and install the wiring for both projects at once which made things much easier.
Once the connector (and fuel gauge) was installed it was time to begin the wiring. I already knew I was going to install a terminal block for all the connections so I added short jumpers to the connector before installation that would reach my intended location for the terminal block. For the power wire jumpers to the terminal block I used 16awg wire, which was the recommended wire size from Raymarine.
Originally there was a run of 12awg wires directly from the batteries to the electrical panel that ran directly below the point where I was installing the new terminal block. When I had upgraded the electrical panel last year I replaced that wire with heavier 6awg, but chose to leave the 12awg wire run in place but disconnected. Therefore I already had a run of 12awg red wire in place that just needed connected to a breaker on the panel and connected to the new terminal block. I pulled the black wire out from the run and used some it for a dedicated ground run from the terminal block to the main ground buss, and since this was all done at the same time as the fuel system, another length of the black 12awg wire for a dedicated ground from the fuel tank to the main ground buss.
With the power all settled now it was time for the NMEA 0183 data connection from the chart plotter to the tiller pilot. I had a length of duplex wire originally ran to the old transducer that was long ago removed, but I saved the wire. I figured that would be perfect for the data wire and pulled that through from the lazarette to the head where all the chart plotter wiring is located.
When I first installed the chart plotter I used butt splice connectors for attaching everything, and zip ties to hold the wire bundle together, and on top of that had the wires inside the cabinet where the instrument wires originally were ran, which is a very hard to access place. Since I have had to undo that once before to (unsuccessfully) wire in the old depth alarm klaxon into the chart plotter alarm circuit, I knew that this time I was moving the wires where I can easily get to them, and connecting everything with a terminal block for easy changes down the road. I used 2 more of the small #6 weld-mount studs that I had used left over from the fuel system installation and mounted a terminal block inside the head and against the hull. This space is actually a small void that is covered by a splash panel above the sink and has about 2.5″ of space behind it when screwed into place. I originally discovered the space when I was running the heavier power wires to the new electrical panel, since there is no way to run the heavier gauge wire where the old wires were ran, and had ran them through this space which is directly adjacent to the panel for easy cable routing.
I cut all of the butt splices for the chart plotter and terminated everything with ring connectors, including the NMEA wires, and connected everything to the block.
There was some initial confusion as the Raymarine instructions call one of the wires NMEA- and say it should be attached to the NMEA- wire from the chart plotter, but in reality the wire just needs connected to ground since the tiller pilot does not transmit any NMEA data. Once I got that figured out with a little help from the sailboatowners.com forum, all that was left was to mount the pilot.
The instructions say that the tiller pilot needs to be installed 18 inches forward of the rudder post, but due to the shape of my tiller, that just wasn’t going to work since the tiller curves very sharply upward there at roughly a 45 deg angle. Since the instructions make no differentiation for different rudder types, I concluded that 18″ forward of a skeg hung rudder is really the same as 18″ forward of the leading edge of a balanced spade rudder for whatever calculation they used to determine 18″ as the target distance. Since I have roughly 5 inches of rudder in front of the post, that should mean that I can move the attachment point forward by up to 5 inches without affecting the performance. This solved the issue of installing the pin on a 45 deg angle, and got me onto a close enough to level part of the tiller to be able to accommodate the pilot.
Due to the cockpit config layout I needed to purchase the cantilever mounting arm to attach the pilot, and as it worked out it was already the exact right length, so I didn’t need to cut it down at all. The base of the cantilever arm is a machined aluminum plate that includes a backing plate, and it thru bolted to the side of the cockpit, Once the arm is screwed into place it is a very solid piece, and I am confident in it’s strength and durability. It was hard shelling out an additional $80 for a mounting bracket, but it is a quality machined part that will certainly outlast the tiller pilot itself, so I felt less bad about the cost once I received it. Additionally I was able to mount the bracket right next to an interior support bulkhead so it is very solid.
The only issue with the mounting location was that due to a chine in the cockpit the cantilever arm had to be installed either 1/2″ too high or a couple inches too low for the pushrod to attach to the pin on the tiller. My solution was simple, install the cantilever arm high, and then cut off a piece of the pin on the tillerpilot that in attaches with to make the pilot sit lower on the arm. A quick clamp in the work bench and a few minutes with the Dremel and a cutoff wheel , followed by a cleanup with a grinding wheel and it was all set.
With the shorter pin the pilot fits onto the tiller just right, all that is left is to go sailing!