autohelm modification - adding a wired remote control
autohelm wired remote;
some conceptual thoughts.
by Adrian Biffen
I was really enjoying the freedom
provided by the autohelm system, but I wanted
to take it a step further by modifying it so that I could control Serenade from other locations in the boat. Being able to sit below in front of the propane fireplace, for instance, would extend our cruising season well into the shoulder months. To do that safely (and to keep warm), I needed to be able to change course from below decks, without having to go outside into the cockpit.
There are two important design elements that always need to be carefully considered when undertaking an automation project involving personal safety: redundancy
Although I am also adding a hand held wireless radio (RF) remote control to provide the most flexible control, I first wanted to install a wired extension of the autohelm course adjustment switches in the salon interior. This will provide me with three levels of redundancy.
If the RF wireless system fails, I can fall back to the wired remote; if that fails, I can fall back to the input switches on the autohelm, and if the autohelm itself fails, I can pull the tiller down from the vertical position, disengaging the autohelm altogether, and assume good old fashioned manual steerage (heaven forbid!).
From the accessibility point of view, there will be several hand held remotes, attached with Velcro, placed in various strategic locations. The wired remote (picture below) will be in the cabin entry area so that it can reached from both the inside and outside. The autohelm unit will be placed just under a hatch opening, so you can just lift the hatch to get at it instead of having to reach down into the bowels of the boat. The tiller will normally stand in the vertical position to keep the cockpit clear and open while in remote mode, but pulling it
down into the normal position will immediately release it mechanically from the autohelm without pushing any buttons, so full manual control can be assumed very quickly in times of emergency.
There are port and starboard steering buttons that accept course change commands. Pressing one of them with a momentary push will change the course by one degree. Pressing it quickly 3 times will change the course by 3 degrees, and she will come around and lock onto the new heading. Hold the button down for a few seconds, and she'll alter course by ten degrees. There are other combinations that allow you to tack or reverse course, but I mainly using the minor course changes only.
The autohelm system quickly became indispensable, especially when I am single-handing her. Whether I'm going below to warm up in front of the fireplace or up on the bow for a sail change, I can count on it to maintain my course heading while I am otherwise occupied. It doesn't compensate for tide drift and other influences, but occasional minor adjustments will keep your heading true. It is truly one of the most useful devices I have ever seen in the boating world.