Hi!
I like the idea of having multiple places you can drive the boat -- it might be nice to have a waterproof pot to take up on the foredeck when deploying or retrieving the anchor singlehanded -- sort of the converse of having a windlass control in the cockpit.
If your lee helm is radio-controlled, be sure you check the spectrum! It would be a shame if someone crashed your boat instead of his toy plane.
I wonder, though, why you would ever want your boat to hover (unless of course you are drilling in the seabed). If you are really in an anchoring situation, you can anchor at no energy cost, and you will swing with the other boats around you, which they may prefer to you actively hovering. If it's too deep to anchor, you can sail. If you need to come back to where you are, you can go in a circle (the man overboard is definitely not interested in the blender hovering over his position).
And, doesn't the first law of thermodynamics say that you can't use the wind and the current to generate electricity to counteract the wind and the current? I understand how you can make electricity from the wind if anchored or docked, and currents if anchored or moored, but I think you would burn it much faster than you made it while actively hovering.
Paul
--- In electricboats@yahoogroups.com, "Galstaf" <richard@...> wrote:
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> I would think that all the things I am looking for would be available as components for a radio control boat set up. Servo and stepper motors are common place, and anyone that has seen an episode of Mythbusters or two has seen some pretty neat setup created by the tech guy Grant.
> Most computer based gps models have a serial output mode that spits out coordinates every 0.5 second or so. This information could be fed into a controller that guns the motor in a particular direction until the acceptable parameters are met again.... effectively keeping the boat in one place.
> I don't personally have this knowledge, but know some kids that do (robot wars types from the local university).
> I just wondered if anyone has already done this and gotten this ahead of me.
> A nice secondary advantage of such a system is the boat could be controlled from anywhere on board... or even a mile or so away with some decent radio controllers! :-)
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> --- In electricboats@yahoogroups.com, Steamboat Willie <stmbtwle@> wrote:
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> > The technology exists, as that's how deepwater drillships maintain position when it's too deep to anchor.  However I rather doubt it's cheap.
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> > --- On Mon, 11/8/10, Galstaf <richard@> wrote:
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> > From: Galstaf <richard@>
> > Subject: [Electric Boats] Re: Long Range Boating with Multidirectional Docking Electric Motors
> > To: electricboats@yahoogroups.com
> > Date: Monday, November 8, 2010, 1:48 PM
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> > Thx for the heads up, Hans! Very good point. One other thing I thought would be useful for the articulating drive is the possibility of having a virtual (or active) anchoring system.
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> > As the boat I am planning will have pretty substantial wind turbines/solar to keep the battery bank topped up and the motors powered (planning a 20kW system), I am hoping to either find a gps based system that one could basically tell the boat to "stay put", and every time the tide or wind push it out of its given gps position, it fires the directional motors to push it back into place.
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> > I don't know whether such a controller currently exists or it is something that I would have to work with some of my electronics buddies with to program.
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> > Anyone know of such a beast? If no one is yet selling something like this that anyone is aware of?
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> > --- In electricboats@yahoogroups.com, Hans Kloepfer <hanskloepfer@> wrote:
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> > > Hello Galstaf.
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> > > I read your post about catamaran drive and maneuvering systems and thought I may put in my two cents. I work for a charter boat company called Adventure Cat in San Francisco Bay which operates sailing catamarans in the size range you are contemplating (www.adventurecat.com). On a normal day we take the boats on and off the dock at least three times in most any conditions. The boats have conventional inboards with spade rudders. I also sail my own boat, an electric auxiliary 32 foot full keel pearson vanguard sailboat.ÂÂ
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> > > The interesting thing is, I can honestly say that with some basic twin screw operation skills, it is probably easier for me to dock the 65 foot cat than my own 32 foot monohull. This is because of the tremendous maneuverability afforded by twin screws so far apart. With a little practice you can pretty much walk the boat sideways if you want. You can spin around on a dime by employing contrary port and starboard thrust. If the screws are counter rotating you can pretty much ignore the effects of prop walk.
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> > > If I were to build an electric cat myself (which I would love to do) I would not ever bother with the extra cost, complexity, or weight of articulating drives because you just don't seem to have that much to gain. Catamarans with hulls spread so far apart with twin screws are already spoiled for maneuverability.
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> > > I can see the advantage of articulating drives on a single screw boat which does not have the luxury of the twin screws. I have seen installations with trolling motor pods mounted on transom hung rudders. I think that looks like a pretty cool and effective concept.
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> > > All things considered though, if that is the system you want, and you can afford it then go for it. You are in the position to build your dream boat (something I have always wanted to do) and you should do it however you want.
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> > > Good luck,
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> > > Hans K.
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> > > --- On Sat, 11/6/10, Galstaf <richard@> wrote:
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> > > From: Galstaf <richard@>
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> > > Subject: [Electric Boats] Long Range Boating with Multidirectional Docking Electric Motors
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> > > To: electricboats@yahoogroups.com
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> > > Date: Saturday, November 6, 2010, 5:16 PM
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> > > Hi all... been following the group for a couple of weeks now with interest and am putting together my plans for an electric catamaran around 50 feet in length, 17 foot beam and about 25000-30000 pounds total weight. Estimated draft is about 20 inches.
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> > > I am working on control systems and have heard of these "easy docking" systems that consist of an electric motor that can rotate in any direction and is guided using a joystick type "drive-by-wire" situation (no mechanical connection between steering control and the actual rotating rudder/propulsion mechanism).
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> > > What I am wanting to do is use this type of system with electric wire controls for long distances (hours at a time) *instead* of having a docking system and a main drive/rudder setup.
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> > > Ideally, when coming into dock, the same system can then be used to drive the boat sideways, forwards, backwards, whatever for easier docking. It could also be a great system for emergency maneuvers if ever necessary.
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> > > So for those with far more experience in these matters, I have a few questions.
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> > > 1. Is it possible to put together one of these systems to power the boat full time... i.e. drive the boat in a mostly forward direction for hours at at time with no ill effect?
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> > > 2. Can these motors be used effectively up to around 10 knots without excessive drag on the hull? Would the propeller size/style need to be changed? (Typical target cruise speed is going to be 4-6 knots).
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> > > 3. Can anyone that is actually using a system or is intimately familiar with one in actual usage make a recommendation for a brand and type of these docking motors for a craft of this sort of size?
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> > > Thoughts and comments from experienced mariners is sincerely appreciated!
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> > > My Best,
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> > > Bill
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