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Is there such thing as an autopilot to hold a heading?

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Is there such thing as an autopilot to hold a heading?

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Old 02-19-2018, 04:29 PM
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Larryy
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Default Is there such thing as an autopilot to hold a heading?

Hi everyone. I'm new to this forum and would like to know if anyone here knows if I can get an accessory or a new radio that will hold the heading of my sailboat when I set it. Maybe a toggle switch to engage. When my boat is distant and I can't see it very well, it is difficult to hold a heading when I am abeam. I would like to be able to tack or jibe then set the course and have the boat go more or less straight until I want to change the heading. Any ideas are appreciated.
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Old 02-20-2018, 06:06 PM
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Just thinking out loud, a gyro should work (?)... if it works for heli tail, I don't see why it wouldn't work on a sail boat
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Old 02-25-2018, 01:24 AM
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Holding a sailboat on a compass heading basically doesn't work. On any typical area of water, the wind direction changes at various points depending on the surroundings. Trying to hold a set compass heading without knowing the wind direction where the boat is simply doesn't work, or is unlikely to work unless there is a very cleverly programmed computer on board.
With free sailing boats, there are various methods of having the boat hold to a heading on the wind - weighted rudder, Braine, vane are some.
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Old 03-04-2018, 05:32 PM
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With the electronics available today (e.g. single board computers smaller than the palm of your hand with built-in pwm servo control function for less than 10 bucks), It would be easy to add relative wind sensing and command a sheating servo in response... or to sense and correct direction... actually, it would be pretty easy to have the computer use those functions along with the location of the next waypoint it's headed for to [somewhat] optimize its route to the point -- and, while we're adding to the function, you could add an override in case it experiences a local wind that has it sailing into a calm or otherwise unsuitable area.

It would be a lot of fun to build, but not a lot of fun to "sail"
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Old 03-04-2018, 05:48 PM
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What about NOT a heading "holding" GYRO but a gyro to smooth wind gusts to keep the sailboat going relatively straight. You would still control the heading, but imagine the sailboat would not "swirl" every time a gust of wind would "hit" the sails or a wave hit the bow. Like in an RC airplane. it does not FLY the plane, just " smoothes" the flight path. So as the model would look more like the real thing. That' what it does for airplanes.

Would,t that be great on a sailboat?
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Old 03-04-2018, 06:34 PM
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That would be a great thing to have!
When a sudden gust hits the boat and it swirls into the wind, what's usually happened is that the boat heeled so far that the rudder lost control. Most boats are set up to naturally turn into the wind if they lose rudder as a safety function. (It doesn't feel very safe when you're on a boat that does it and because the wind pressure is suddenly off the sail as the boat comes into the wind it sometimes capsizes. A sailboat's just no fun when the keel's pointing up and the mast's pointing down.)

I'm thinking that what causes the boat to turn in a gust might keep it from being able to be kept in control by steering -- but maybe that's not true. It's worth thinking about...
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Old 03-05-2018, 05:07 AM
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Originally Posted by Al Stein View Post
That would be a great thing to have!

I'm thinking that what causes the boat to turn in a gust might keep it from being able to be kept in control by steering -- but maybe that's not true. It's worth thinking about...
On a plane , the gyro does not prevent stick control, it just keeps the plane "straight" if the sticks are not moved. I think it would be doable.
Maybe someone here is smart enough to make a prototype.
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Old 03-05-2018, 08:58 AM
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By what might keep the boat from being controlled by steering, I meant lack of rudder effectiveness when the boat's knocked down by a gust of wind. Most of the time, I believe you're quite right... it wouldn't be very hard at all to set up a system to control direction (and allow skipper override) as long as the boat is moving along normally. (Although to move well it would need to control sail set, too)

On a reach or a run that should usually be no problem. Even on a tack, maintaining heading should be doable unless the wind gets too high on the bow or crosses the bow... but all that depends on being able to steer. Using dual rudders should help with that, though I doubt that even a rudder mounted far off center would maintain control in a total knock down. (I'm assuming this is not to be used on a racing boat unless the rules for its class specifically allow such a thing. I would think that would be quite unusual.)

Other than with loss of rudder control, yes, I'm sure that any of a gyro or gps or magnetic compass could do the job.
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Old 03-18-2018, 09:21 PM
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Wow! I really do appreciate all the feedback but somehow the real desire got lost in the brainstorming. I am not class racing, just pleasure sailing. Gusts and changing wind direction is not a problem. My problem is that when my boat gets far away and I am seeing it from abeam it might change heading substantially without me detecting it. I cannot steer a straight heading. Bow to or stern to is no problem. I would simply like to establish a heading and know the boat will hold it until I change it, much the same as I do on my 30' Catalina with my autopilot.
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Old 03-19-2018, 05:40 AM
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Larryy, under the scenario I have described, the boat would NOT change direction unless you'd sent an direction "change" with the input of your stick. So it would achieve what you're looking for IMO.
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Old 03-20-2018, 07:41 AM
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I agree -- for what you're looking for there, in the very first reply to your question vasek proposes what looks to me like a good, straight forward solution (figuratively AND literally straight forward )


(I did enjoy seeing the various related thoughts people had -- always have something to learn!)

Last edited by Al Stein; 03-20-2018 at 07:43 AM.
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