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Old 13-12-2010, 07:13   #16
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Quote:
we found that there is an arm, bolted to the rudder stock, above the quadrant, that had worked loose.
That will do it - had the same problem a few years ago with my Alpha autopilot - the set screw had become loose, and a tiny little difference at the rudder post made a huge difference in direction, and for that matter in just driving straight. Only 28 years on my unit, where can I get something that will last? ;-)

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Old 05-05-2017, 19:17   #17
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Re: Alpha 3000 power consumption

My understanding is one of the strong points of the Alpha systems is their energy effeciency. They utilize 80% of the energy needed to run the system while many other systems only utilize 20% effeciency of power needed. So, in effect they require far less power to run than other systems. That is what I have heard.
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Old 05-05-2017, 21:10   #18
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Re: Alpha 3000 power consumption

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Originally Posted by Sailsarefull View Post
My understanding is one of the strong points of the Alpha systems is their energy effeciency. They utilize 80% of the energy needed to run the system while many other systems only utilize 20% effeciency of power needed. So, in effect they require far less power to run than other systems. That is what I have heard.
The biggest power saving with Alpha APs is because their system doesn't use a clutch to engage the drive. This is a small, but constant power draw. Instead they have a mechanical link to the drive arm to engage and disengage the drive to the rudder.

Otherwise the power draw for the drive, computer and overall efficiency of the system is comparable to other units. Not sure exactly how much power a typical AP drive clutch draws but I believe as much as 15-20 amp hours / day.
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Old 05-05-2017, 23:16   #19
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Re: Alpha 3000 power consumption

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Originally Posted by skipmac View Post
The biggest power saving with Alpha APs is because their system doesn't use a clutch to engage the drive. This is a small, but constant power draw. Instead they have a mechanical link to the drive arm to engage and disengage the drive to the rudder.

Otherwise the power draw for the drive, computer and overall efficiency of the system is comparable to other units. Not sure exactly how much power a typical AP drive clutch draws but I believe as much as 15-20 amp hours / day.
Lacombe and Schmitt claim that their "Eco-Drive" saves 25 ah. over a normal clutch relay. From 30 to 5 ah per day.
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Old 06-05-2017, 00:08   #20
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Re: Alpha Autopilot

Alpha may save some power by not using a clutch or bypass solenoid, but the units use a lot more power because their brains are dumber than a fence post. The motor is constantly running as the boat fishtails across the ocean.
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Old 06-05-2017, 05:06   #21
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Re: Alpha Autopilot

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Alpha may save some power by not using a clutch or bypass solenoid, but the units use a lot more power because their brains are dumber than a fence post. The motor is constantly running as the boat fishtails across the ocean.
Interesting. Your's isn't the only comment I've seen that Alphas steer like this but I've also seen several that claim they steer straight as a train on tracks.

Seems like different users have very different experiences.
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Old 06-05-2017, 05:10   #22
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Re: Alpha Autopilot

How much have they upgraded the "brains" on them over the years? As they've been around for a long, long time.
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Old 06-05-2017, 06:12   #23
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Re: Alpha Autopilot

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Alpha may save some power by not using a clutch or bypass solenoid, but the units use a lot more power because their brains are dumber than a fence post. The motor is constantly running as the boat fishtails across the ocean.
That's not accurate.... you can adjust the yaw to limit the "corrections" the pilot makes.

There are multiple factors which are included in the "steering" algorithm... including rudder feed back and data from the fluxgate compass. In bouncy conditions the compass input needs to be damps as it is not representing the heading accurately... the compass will move way more easily than the boat. To mitigate this the fluxgate should ideally be in the center of mass of the boat... obviously the bow and stern move laterally way more than the center of mass. If the compass placement is less than ideal... the compass will show more "false" fluctuations in heading and the pilot will make more "corrections".

Note that a pilot usually does not have the ability to move the rudder as much as a helmsman does. It essentially makes small corrections to maintain heading. When the boat is being tossed about by seas small corrections don't cut it and so the boat CAN trace an S course. This would be true for any pilot which has a limit on rudder range.

The skipper can essentially dampen the corrections and the pilot doesn't respond to every wave....kinda.

The same issue is seen when on a beam reach and you are hit by a gust... the boat will round up and needs a fast response on more rudder to prevent rounding up.

APs don't think and they don't see weather and wave trends. A person at the helm can and should.

My experience with the Alpha is positive and it's been driving Shiva for more than 25 years. My boat in moderate conditions and good sunlight can run the AP and the instruments on 2 - 55 watt solar panels... something like a 3 amp draw.
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Old 06-05-2017, 07:17   #24
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Re: Alpha Autopilot

Without going into all the history ...
We've been running an Alpha 3000 ram controlled by a Raymarine course computer. Power consumption is very low, unit is quiet and she tracks like a train on rails. And we have a wireless remote controller that is a real convenience.
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