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Old Jan 03, 2014, 03:44 AM
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Hi Pete,

I have 2 12V 7A batteries which has always been more then enough power for this model.
I easily sail an entire day on 1 of those batteries.
I can check the smaller windshield washer pumps, I think the bigger ones might be too powerful and too big but I can sure give it a try.
I need to bring my car to the garage next monday anyways so I can ask for some specs then.
I needed to avoid a car coming my way and whilst I did manage to avoid an accident I did scratch the railing...

The new hull will have 9mm thick plywood keel, frames and longitudenal girders and 3mm thick plywood outer hull and ballast tank walls.

Greetings Josse
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Old Jan 03, 2014, 12:39 PM
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Modern versions are useless. Try to find the older VDO version from BMW or Mercedes. The older version create a vacuum and suck the water out, most modern cars need to have a fluid level higher then the pump.

Danny
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Old Jan 03, 2014, 12:56 PM
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Hi Danny,

Do you know how much power those pumps take?
If they use too much juice I'd prefer to be look for other solutions.
I could at least ask how much power the modern pumps use because it will most likely give me some indication of how much power we're talking about.

Greetings Josse
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Old Jan 03, 2014, 02:20 PM
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No idea how much they use. Try google. Robbe and graupner used to have them. Conrad also sold a good pump for fuel models. A small black KAVAN pump. For used/second hand pumps, you can go to the car-wrecker starting with a B and an A in the name (no need to make advertising) in Charlois (Rotterdam South for non-dutch).

Now I should get ready for the grave-yard shift.

Danny
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Old Jan 09, 2014, 10:00 AM
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They can use up to 1.5amp under load,

That said , you may want to go for a reversible gear pump..or you may use a 12v solenoid valve for water below the water line, this will allow you to use gravity to fill your tanks ,and the pumps to dump them..
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Old Jan 09, 2014, 10:23 AM
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Hi Coffee,

Thanks for the info.
The ballast issue is still something that I want to resolve quickly as a large power consuming pump may require a bigger and heavier battery and in that case I need to downsize my ballast tanks now I still can.
If it's just 1,5Amps it shouldn't be a problem as the tanks should be filled in a matter of minutes.
In a worst case I could set 2 pumps up per tank, 1 to fill it and 1 to empty it.

Whilst writing this post I'm doing the maths again in my head and I had already realized that I might only have about 5-8kgs left for the superstructure as the new hull is much heavier then the first hull.
That means I'll probably shorten the ballast tanks by moving the aft end of the tank 1 frame forward.
This all is with the idea that I want the tanks to be completely full when sailing but still want to have enough room for lots of functions and a very good looking superstucture which requires quite some metal parts.

Greetings Josse
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Old Jan 09, 2014, 12:15 PM
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I got to looking around.

I found a that there are 12v DC water pumps for aquarium use on E-Bay.

http://www.ebay.com/itm/P-38E-109GPH...-/301002676248

the link above can offer you 6.5 kilograms of water in a minute @ 500ma

http://www.ebay.ca/itm/2pcs-Mini-Bru...item46181881fd

There are a ton of low power high volume pump's on E-bay.

As a thought , you could divide your hull up , use bladders or such to pump water to different quadrants of the ship to adjust its trim via 12v solenoids.
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Old Jan 09, 2014, 04:42 PM
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Hi Coffee,

Thanks for the links, that's really great help!!
For that kind of money I could easily buy new and have several sets of them.
The pumps in the second link might well be suitable for my application, both for ballast pumps and for the fire monitors.

As for the quadrants, that is exactly what I intended to do, a total of 4 ballast tanks in 2 rows of 2, having the keel serve as watertight seperater and 1 of the frames somewhere in the middle will also be watertight.
I'll search for the solenoids tomorrow, it sounds like a good option to reduce the amount of pumps.

Greetings Josse
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Old Jan 09, 2014, 07:38 PM
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for fire monitors you will require a pressure pump,with a filter or screen. washer pumps ,or something a little more industrial

http://www.ebay.ca/itm/12V-Direct-Cu...item58a642b5b4

(this is not a brushless motor on the pump ,its actually a RS380 motor.)


aquarium pumps are generally flow rated not pressure rated. unless in the case of certain filters that require a pressure pump.

If you notice ,and aquarium pump is often rated in Lph or Gph rarely will you find a PSI or Mpa rating on an aquarium pump.
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Old Jan 10, 2014, 01:12 AM
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Hi Coffee,

Thanks for looking it all up!
That indeed looks like a suitable pump to power the fire monitors.

Greetings Josse
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Old Jan 10, 2014, 03:27 AM
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Hi Coffee,

Did you mean a solenoid like this: http://www.ebay.com/itm/12V-DC-2W-1-...item1c3b1e43ca

The aquarium pumps you gave links for are indicated as brushless.
For as far as I knowledge about brushless motors go those motors can't simply be connected to a power source to make them run at full power, a special ESC is needed for that.
Is that ESC build in to the pump so it's a simple connect-the-power-and-it-runs-at-full-power solution or do I need to buy it seperately to make it work?

I did a recalculation combined with a new ballast tank layout and I found out the calculation which came out at some 8L of ballast tank was off as well, I multiplied the bottom tank of which I had taken a breadth that doesn't fit twice inside this hull.
The new, still to be checked, calculation came out at 4,4L of ballast which is a nice amount to start with.
It leaves room for the heavier hull and superstructure, all the needed equipment and the batteries and maybe I'll still need to add a bit steel but it will certainly not be as much as it used to be.

Greetings Josse
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Old Jan 10, 2014, 08:40 AM
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No you do not need an esc to run these types of motors ,They run 12v from any 12v source .
The brushless motors your thinking about that require an ESC the motor has Three connections
The motor are brushless ,but have an iron ferrite core on the shaft, set-in an encapsulated copper winding

http://www.ebay.com/itm/1-2-DC-12V-E...item20dd18f4dc

I was thinking more like this. cheap ,
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Old Jan 10, 2014, 08:57 AM
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Hi Coffee,

It's great that I don't need an ESC.

The solenoid in your link looks great.
I'd need to think this through properly as using solenoids means I'd need to test how much there should flow to each of the tanks, that will be a matter of testing and adjusting and then start over again but it certainly is cheaper then 4 pumps and it will most likely also consume much less power.

Greetings Josse
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Old Jan 10, 2014, 11:48 AM
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I think ,you may just have to eyeball the trim.

without some sort of water proof sensor array. Its just going to get a lot complicated.
personally ,I would just put the pump on a master, and 4 switches to open or close any particular solenoid to fill.

to dump them , I'm assuming your ballast tanks will be made into the hull ,from wood.
you could put the solenoids at the bottom closest to the keel.

two solenoids on each tank one to fill ,the other to empty. a pump to fill, and a pump to discharge the ballast ,

so Two pumps ,and 8 solenoids , some creative arduino programming to set up 10 ,5v relays. and your in the pipe ...literaly



If you do decide to go for relays, try to get the solidstate relays ,the mechanical relays may cause a whole pile of transient current if they are not properly snubbed..
Also ,solid state relays have no moving parts , and quiet.. they can last 100,000 cycles or more and wont be affected by moisture fouling the contacts.

just make sure the solid state relays are rated to switch DC current..
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Old Jan 10, 2014, 12:15 PM
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Hi Coffee,

Your idea of using a total of 8 solenoids and 2 pumps sounds good.
I just had a good idea, I could fit a polycarbonate in front of a long opening in the wooden inner hull that is the inside of the tank.
Also I can put a electric wire in the top of the tank which, when the water is at the top of the tank, makes contact with another wire end and use that to close the associated solenoid and put the signal through to the Arduino to make sure that the pump will be stopped when all 4 tanks are completely full.
That would take up the best of all possible methods.

The ballast tanks are being put in between the frames, where most frames will have holes to make the water flow through it, so I got as much useful room as possible whilst having relatively large tanks.
Should the outer hull start to leak it will leak into the ballast tank so when it's filled it will first start to flow out of the tank until the water levels.

Greetings Josse
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