Found a great booklet on autopilots & wind-vane steering while surfing around. I'm looking to acquire an auto-pilot for my Cal 21' this winter. I like the idea of wind vane steering but the units are too much for my boat and the type sailing I do. You can down load the booklet, 142 pgs, at the site. A little dated, but not much.
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Do you Have enough Amp hours??
Autopilots draw significant amounts or current!!! Not much of a problem for a few minutes to raise and lower sails, but all day it adds up. Assuming you have an outboard engine you will need a solar panel to power the autopilot. You might want some other self steering such as a jib sheet to tiller and a bungie cord.
Autopilots draw significant amounts or current!!! Not much of a problem for a few minutes to raise and lower sails, but all day it adds up. Assuming you have an outboard engine you will need a solar panel to power the autopilot. You might want some other self steering such as a jib sheet to tiller and a bungie cord.
Amps
Tom, I just checked the specs on the ST series auto pilots, ST1000 tiller pilot in auto pilot mode draws .5 to 1.5 amps (depending on sail trim, etc) and the spec on the ST4000 wheel pilot is 10W at 25% duty cycle which is less than 1 amp (again depending on sail trim). I don't think I'd characterize this as significant amperage. A single G27 house battery could run that all day without a problem. As to wind vanes, I always thought of those for cruisers who would stay on a tack for at least an entire day. Fair winds, Jim
Tom, I just checked the specs on the ST series auto pilots, ST1000 tiller pilot in auto pilot mode draws .5 to 1.5 amps (depending on sail trim, etc) and the spec on the ST4000 wheel pilot is 10W at 25% duty cycle which is less than 1 amp (again depending on sail trim). I don't think I'd characterize this as significant amperage. A single G27 house battery could run that all day without a problem. As to wind vanes, I always thought of those for cruisers who would stay on a tack for at least an entire day. Fair winds, Jim
But the other stuff
Add in the depth sounder VHF FM radio or CD player etc and you can have a load. Don't forget anchor lights. It all adds up. My autopilot is a little old so it draws more. Tom
Add in the depth sounder VHF FM radio or CD player etc and you can have a load. Don't forget anchor lights. It all adds up. My autopilot is a little old so it draws more. Tom
It's called an energy budget
1. West Marine Advisors Online: http://www.westmarine.com/pdf/Elecbugt.pdf 2. The West Marine catalog and just about every single other boating electrical book will give you the loads for various gear needed to input on this worksheet (i.., Calder's, Casey, etc.) 3. Bet you could find a list of loads either somewhere on this website (archives) or BoatUS Ask the Experts.
1. West Marine Advisors Online: http://www.westmarine.com/pdf/Elecbugt.pdf 2. The West Marine catalog and just about every single other boating electrical book will give you the loads for various gear needed to input on this worksheet (i.., Calder's, Casey, etc.) 3. Bet you could find a list of loads either somewhere on this website (archives) or BoatUS Ask the Experts.
Auto-pilot
My energy load can be kept relatively low, due to lack of power hungry items, ie..no stereo and hand-held VHF for monitoring. Depth sounder is not too high draw, VHF is manageable if you don't talk, and I'm searching for LED nav. lts. (without alot of success). I am not enamored with what I've seen in the solar panels, the ones from west marine aren't even water-proof! I'm thinking of a water-generator. Crossing Lake Michigan is where I'd use it. Everywhere else, I can pull and recharge my batteries. I figure I would re-coup the cost of the generator with it's longevity versus the panels, and on Lake Michigan, I think I'm more likely to have enough wind to tow it than sun for the panels. One thing I think I want to do though is to run the auto-pilot off apparent wind versus the internal fluxgate compass. So now I have to consider which "system" would suit me best without spending more than I bought the boat for. Well, I guess the water generator shoots that out of the air anyway! Any thoughts on this? Guy
My energy load can be kept relatively low, due to lack of power hungry items, ie..no stereo and hand-held VHF for monitoring. Depth sounder is not too high draw, VHF is manageable if you don't talk, and I'm searching for LED nav. lts. (without alot of success). I am not enamored with what I've seen in the solar panels, the ones from west marine aren't even water-proof! I'm thinking of a water-generator. Crossing Lake Michigan is where I'd use it. Everywhere else, I can pull and recharge my batteries. I figure I would re-coup the cost of the generator with it's longevity versus the panels, and on Lake Michigan, I think I'm more likely to have enough wind to tow it than sun for the panels. One thing I think I want to do though is to run the auto-pilot off apparent wind versus the internal fluxgate compass. So now I have to consider which "system" would suit me best without spending more than I bought the boat for. Well, I guess the water generator shoots that out of the air anyway! Any thoughts on this? Guy
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