Did a dream got shattered?

Discussion in 'Boat Design' started by BertKu, May 16, 2010.

  1. BertKu
    Joined: May 2009
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    Location: South Africa Little Brak River

    BertKu Senior Member

    I like to burden you with a task. A remote receiver with failsafe code and 40 Amp relay contacts cost me Euro 27.60 to make, some parts potted in.

    Could you please calculate for us what the cost is for tinned MARINE cable 3 core or 4 core for a 8 meter yacht, in total, inclusive labour, faultfinding etc.

    Then we will calcultate, (what you call a gimmick) what it cost with failsafe receivers. The consumption in standby mode is only 20 milliAmpere.

    What are you talking about, what Integrated Circuit? (IC)

    Bert
     
    Last edited: Jun 7, 2010
  2. apex1

    apex1 Guest

    Forget it, senseless.

    IC means Internal Combustion....btw..
     
  3. BertKu
    Joined: May 2009
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    Location: South Africa Little Brak River

    BertKu Senior Member

    I thought already that we were dealing with an hot air balloon. Show us what you are worth. Gives us the calculation. Just 2 calculations. One with all the extra wires and interconnections and labour and another one for just 2 wires, red and black. For all the lights , all of them, we will have LED low current consumption. The only one we need some power is for the anchor.

    Anybody else who is willing to give a rough calculation?
    Bert
     
  4. BertKu
    Joined: May 2009
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    Location: South Africa Little Brak River

    BertKu Senior Member

    So let us assume that it cost Euro 3000 for a yacht to be wired up, inclusive of expensive marine cable. Because we using only 2 wires and not 3, can we assume that the labour is also 1/3 faster and 1/3 less expensive? It would mean we save Euro 1000. Inview that we spend Euro 30 per point to make the connection. I am saving money. Is it really so stupid to follow the trend in the world to go wireless? What about blue tooth, etc?
    I cannot understand why this forum allows characters like Apex1 freely to insult many different readers at various threads.
    Bert
     
  5. BertKu
    Joined: May 2009
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    Location: South Africa Little Brak River

    BertKu Senior Member

    Allright Richard, maybe I should give you this one. Maybe not practical for the average sailor or that it is money saving for a 8 meter yacht. It would be just convienience in my view. Just 2 wires and a couple of small units.

    However for a 20 meter upwards yacht, it would be adventagious. I have been making and exporting for the last 15 years wireless electronic timers for the horse riding shopwjumping industry. With price money's of a few thousand Euro , it had to be accurate and even with disturbances in the air. Thus remote wireless control is thus not new to me.

    Provided, a yacht is made of wood or glass, but without too much metal.
    On a concrete boat (due to the mesh wire frame), alluminium or steel boat it may not work satisfactory. Although we have already receivers which are down to -120dB.

    But can we in the future debate differences of opinions as grown up man, instead of using phrases which can only lead to arguments.
    Bert
     
  6. apex1

    apex1 Guest

    Do´nt get the question? Sorry.

    But I got that:

    And it is YOU insulting ME regularely.............:mad: :!:

    The point you just do´nt accept is, that there is NO el. propulsion possible at present.*** You are not the only one on this Forum dreaming about it, but as stubborn as your predecessors you are unwilling to give up a premature plan.

    Designed and built to the same properties (seaworthiness, safety, speed, weight, cost, etc.) it is just not possible to store enough energy at present.
    Nowhere behind the horizon is a solution in sight for the next decade at least.

    That was, and is all I did say from the very beginning of your "dream" posts. You took it personal and now start a senseless fight here, argueing in a childish, biased way about my contribution on this board. Hundreds of other members have been quite comfortable and fine with my advice.

    Regards
    Richard


    ***please skimp on links to underpowered lake and river boats, thats not what you plan!
     
  7. BertKu
    Joined: May 2009
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    Location: South Africa Little Brak River

    BertKu Senior Member

    You missed the point. I said that you are probably right.

    I like to disagree with you on all the points you mentioned. If you feel that 25Kwh is not sufficient to power 2 motors at 1 kw, at an for me acceptable speed of 8 - 10 km/h. Yes, if we run continous at displacment speed, yes it would not be great. But if you feel that nobody is allowed to experiment, like Jeremy, Rick, Poorqeedo and myself. That is fine with me, but than skip those threads , we did not asked you to read them, nor to give you your insulting advise.

    Bert
     
  8. apex1

    apex1 Guest

    You can hardly compare the tiny little boats of Jeremy and Rick with what you have in mind, right?

    And a 1kW motor of course is absolutely insufficient for a safe coastal cruising, which you are planning. (even 4 of them are nothing)

    In bad conditions that is a dangerous, probably deadly joke, nothing else.

    But thats your fun, enjoy it and stop calling my name.
     
  9. hoytedow
    Joined: Sep 2009
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    Location: Control Group

    hoytedow Carbon Based Life Form

    When a child moves toward danger, the parent stops the child with a sharp rebuke, with love and caring. Don't mis-interpret the action.
     
  10. PhotoBoatGuy
    Joined: Feb 2004
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    Location: Redmond, WA

    PhotoBoatGuy Rhino fanatic

    Hi Bert:

    I'm coming lately to this thread, so forgive me if it was covered in your previous thread, but what is the reason for reducing the length of the boat?

    Certainly, it's possible to fit the electric propulsion you talk of into the larger boat. Is there some kind of building constraint? In case it hasn't been pointed out, the longer the waterline, all else being equal, the faster the boat will go given a certain amount of power.

    A sensible approach might be to build the boat as drawn (assuming it's a proven design) and accept whatever speed you get from the propulsion you plan on using.

    Another sensible approach might be to build the boat as drawn and increase the power delivered by the propulsion, being mindful that once you are able to make the boat go approximately 1.2 * square root(LWL), any additional horsepower will be wasteful.

    In either of these cases, take the given center of gravity times the weight of the boat This product is called a moment. Then subtract the weight times the center of gravity of each item of the designed propulsion system that you don't plan on using (also called the moment). Then add back the weight times the center of gravity of each "new" item of propulsion (once again calle the moment). Finally, divide the result (the moment of vessel) by the new weight. The result will be the new center of gravity. If this doesn't vary significantly from the original center of gravity, then you've got a winner. If it does, then add ballast as necessary.

    Example: (Wt in lb, cg in feet from origin)

    Weight Weight LCG Moment VCG Moment
    Orig Design 2400 12.0 28,800 3.0 7,200
    Dsl Engine -200 14.5 -2,900 3.0 -600
    Fuel, 30 gal -210 12.0 -2,520 2.0 -420
    Batteries +400 12.0 +4,800 3.5 +404
    Motor +300 14.5 +4,350 2.5 +700
    ---------------------------------------------------------------
    Totals 2,690 31,730 7,284

    In this greatly simplified, the vessel gains 290 lb. More importantly,

    LCG = 31,730 / 2,690 = 11.79
    VCG = 7,284 / 2,690 = 2.71

    So in the above, the LCG moved forward and the VCG moved up. To compensate install ballast centered below 2.71 and aft of 11.79. The aim of this ballast is to move the CG down and aft to match the designed CG.

    The above assumes I've done my arithmetic correctly, which is always suspect. If it's wrong, I'm sure we'll both hear about it.
     
  11. Knut Sand
    Joined: Apr 2003
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    Location: Kristiansand, Norway

    Knut Sand Senior Member

    Heh. THAT reminds me of something... I borrowed (from the scouts) a sailboat 24' once, those hulls are normally pretty easy driven - right?

    Well, as it was, the mast aft stay packed of, signed off.... Mast stayed up, luck and despair... well sort of at least... Not too pleasant, sailing single handed... Got some sort of "control" after a while.... Weather wasn't on my side, that was partly why that aft stay had "signed off". Got the engine running, a 6 hp (that's about 4,4 kw..) engine was going at full throttle, held me away from land, and breaking waves, but; It wasn't enough power to manouvre sideways, and it wasn't enough power to go against the weather (like "away").... I tried everything, I mean everything.... I knew that within less than an hour I'd run dry of fuel. Then it'd would be pretty interesting. I managed to throw a rope with a spanner up on the stays of the mast, managed to catch that free end, managed to make a "loop"... Got it into the winch, tightened. Then I had a crippled "rig" that I assumed could take wind from port side. The keel went sideways out of the water a couple of times.. The "clearance" to the Mother Norway's rocky coast were close to nothing. Got away, but steering was pretty crippled too. Aimed for a gap in a small island, got there, cut the ropes with a knife, crashparked the boat, tied it up, went to bed, woke up with cramps in most parts of the body...

    I was young and a bit stupid... Now I'm not so young anymore.... :p

    Listen to Apex; 1 kW is not enough for coastal cruising.... protected waters, inland, well probably...
     
    1 person likes this.
  12. BertKu
    Joined: May 2009
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    Location: South Africa Little Brak River

    BertKu Senior Member

    Thank you PhotoBoatGuy, much appreciated.

    Yes, I have restrictions. I am considering to reduce the boatplan (Which was bought, not copied) from a reputable boatdesigner by 7%. Provided I can overcome the instability created by this reduction. Original I would like to have it reduced by 13%, but that is out

    The problem with this APEX1 character is that he does not quote correct information, whereby people like you and others and myself are being brought into disrepute.

    The 2 motors are each 12,5 Kw but only for a very short period of time and modifications. For contineous operation with good cooling 5 - 6 Kw each.
    I am planning to use it between 1 and 3 Kw each, which falls well within the boatdesinger's specification.

    We have the best weatherstation from Norway with many stations here in the area. They have been spot on for the last couple of years. www.yr.no
    I am not planning to take a fat chance, however should ever there be a situation, I have a storm jib.

    This APEX character seem to upset many people and should be removed from this forum. But Jeff probably cannot do that, as he maybe a paid stakeholder.
    Thus we are stuck with him,.

    Here is one of the other people he has seen chance to enrage.

    Thread : "Stainless steel rudder" # 17, #18, #19 For your convienience a repeat for you.


    Hello all,

    I found the link on Youtube please see
    http://www.youtube.com/watch?v=j1SZT2xcuuY

    I think you will get a better idea than I can describe in written form. Please note the coating had not been polished in any way, was simply coated and placed in the water where it remained for slightly over ten months. had the coating been polished to say a satin finish the result would have been the same (no corrosion).

    Hope the above link helps.


    Mercury
    #18 Post Feedback Flag for Moderator 06-01-2010, 04:23 PM
    apex1
    Steamer Join Date: Oct 2005
    Rep: 958 Posts: 4,087
    Location: Hamburg

    Quote:
    Originally Posted by Mercury
    ... Please note the coating had not been polished in any way, .....

    Hope the above link helps.


    No, sorry it cannot help. The question was to replace a GRP rudder with a SS made one. In this case every coating is nonsense and leads to crevice corrosion.

    Leave it!
    __________________
    Fortior est qui se quam qui fortissima vincit Moenia.


    apex1

    #19 Post Feedback Flag for Moderator 06-01-2010, 04:33 PM
    Mercury
    Mercury Join Date: Jun 2009
    Rep: 34 Posts: 23
    Location: California

    why is that people do not read before opening their mouths

    --------------------------------------------------------------------------------

    Dear Ms/Mr. leave it.

    If you took the time to read the thread the question was posed to me directly about the potential of reducing the weight of existing Stainless steel rudders, each weighing 60 LBS. My reference was to perhaps replace the SS rudders with a lighter weight substrate and if still wanting to have the appearance of SS then it could be coated with what has been proven to work for many years, with zero crevice corrosion. It is used on Ocean going tankers for at least ten years. So, I suggest before climbing all over someone who was asked for advice and gave it humbly, you take the time to read.

    I will not post again as this type of BS is not worth my time. <<<<<<<<<<<
    Enjoy!


    You see what I mean,
    Bert
     
  13. BertKu
    Joined: May 2009
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    Location: South Africa Little Brak River

    BertKu Senior Member

    You also got fooled by this APEX character. The motors are 2 x 12,5 Kw for a very short period of time and very good cooling, but maximum 5-6 Kw with normal cooling and I am planning to use it between 1 and 3 Kw each. We don't allways have to go at top speed, like Richard - APEX is pushing me to go for. Well within or exeeding the boatdesigners specification.

    We trust your Norwegians, as we have the best Norwegian weather stations close by. www.yr.no. They have been very accurate for a long time.

    No, I will certainly try to avoid situations as you have described.
    Thanks Knut.
    Bert
     
  14. PhotoBoatGuy
    Joined: Feb 2004
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    Location: Redmond, WA

    PhotoBoatGuy Rhino fanatic

    Best to just ignore. If he's not helpful, then, when a post comes up with his name, just move on to the next one.

    Every forum has one.
     

  15. apex1

    apex1 Guest

    Well, ours is Bert!:D
    At least he is doing his best to become it!

    Bertie

    It was your figure these 1kW not mine! So, shut up, and stop calling my name!
     
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