Thanks. I tend to use the autopilot most when motoring to and
from the harbor, where it's ultra-convenient to use the remote to
steer while getting sails ready or putting them away. Or, just for
fun, steering while reclining on the front tramps...
However, sometimes it's also great to just kick back and let the
pilot do the sailing as well. I tend to be awfully lazy when I'm
not in a white-knuckle-bugs-in-your-teeth kind of mood.
I'm still holding onto the possibly unreasonable dream of
counter-rotating balanced fore/aft symmetric foils that work in both
directions. If that works, then the tiller could just stay in
neutral. Heck, you could probably just use a single autopilot;
everything would be the same in either direction with the exception
of the wind and speed inputs. When the autopilot is disengaged the
piston dampens the steering. I sometimes like this, sometimes not,
though I rarely physically disconnect the piston while sailing.
But if the magic rudders don't materialize, you'd definitely have
to disconnect while rotating the foils 180+ degrees.
Note: if you balance the sails well with the steering, the
autopilot does even less work. I know this is obvious, but given
the ability of the longer proas to track well, this might result in
a lower power draw than if you were on a catamaran with significant
rocker.
- Mike
Michael Fischer wrote:
Mike, sounds like a very good setup! I think one still would have to physically disconnect a tiller during shunting, due to rudder rotation - no?
On Thu, Jul 21, 2011 at 2:30 PM, Mike Crawford <mcrawf@nuomo.com> wrote:
As a slight variation/alternative to the standard tillerpilot:
On my catamaran I have an autohelm S1 (same as the old ST4000+) tillerpilot that has the control head, compass, and electronic mounted inside the port hull. The control unit is theoretically waterproof, but I like keeping it under cover anyway. The pilot is just a beefy cylinder, sans display or electronics, that plugs into a waterproof connection on the hull. I keep it inside a hull when not using it.
I believe the S1 is good for boats up to 13,000 lb displacement, with a max thrust of around180 lb (depends upon model), and a current draw of just under an amp at a 25% duty cycle.
I don't know what the specs are on the newest S1's, but even 180 lb thrust is probably overkill. The boat should be sailing close to balanced most of the time, and if you're like most people, it's likely you've never had to apply that much force to a tiller.
Generally I control the pilot with a wireless waterproof smartcontroller, though sometimes I do use the control head.
It's also hooked into the GPS, chartplotters, and TackTick instruments, so it can navigate to a waypoint or series of waypoints, to a compass setting, or to the wind direction (roughly one-minute average). It will happily tack a catamaran, but there's no way it will shunt a proa -- that kind of programmability is generally reserved for the large/expensive/heavy hydraulic systems.
If you wanted to get fancy, you could get two control pistons, one for each tiller, and then flick a switch to determine which is connected to the control unit inside. That would also give you a spare if one breaks. I keep a spare piston in the boat, and also a spare remote that's continuously charging. (a lightning strike required a new system, but left me with working backups of these two components). I don't have a backup control head, but since it's both waterproof and inside the hull, it's not much of an issue.
Besides, the boat is a daysailer, so all of this is over the top.
If you did have a switch that alternated between two pistons, the same switch could also connect alternate sets of wind and water speed instruments, so that the pilot would always be working with sensors that agree with the current tiller being used.
- Mike