Area and volume

Discussion in 'Boat Design' started by Saqa, Jan 3, 2015.

  1. Ad Hoc
    Joined: Oct 2008
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    Ad Hoc Naval Architect

    If you know this..why are you asking?

    Are the other reasons why you will not get the knowledge you seek.
     
  2. Saqa
    Joined: Oct 2013
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    Saqa Senior Member

    This is just getting childish. Quoting a line out of a paragraph and adding it to another line from another paragraph is in poor form and will not work for you to try to change the context of what I wrote

    You listed a few of my recent threads. You stated I have not presented a SOR. You neglected to list the thread that did have have the SOR, so try to do a better job next time if you are going to pick on me

    I had some idea that the cheat might offer usable data but since I am not educated in this I thot to ask on a boat building forum. Again, if you have a problem with this process then point it to a moderator

    Your statement of "not even close" has shown to be incorrect, that is not very professional for someone who boasts his expertise in his user data and goes around like a stalker to someone trying to figure something out

    Please do not bring my search for some help down with your personal vendetta
     
  3. Ad Hoc
    Joined: Oct 2008
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    Ad Hoc Naval Architect

    Please state where i have express this...?

    Sorry, again, just paranoia.
    Please state where this is a personal vendetta?

    May I suggest you moderate you replies as they are becoming emotive, personal and highly subjective. Such replies do not elicit the information you seek from others with such an attitude. All you're doing is alienating yourself.
     
  4. Saqa
    Joined: Oct 2013
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    Saqa Senior Member

    Under your username. As a long term forum programer and admin, with the social study from it I see this as a method of trying to create a place within forum users as perch to fire opinions from that 'should be taken as qualified'

    What I see as personal vendetta, you have come across some some of my questions in this forum. From how you have addressed them in this thread it appears to me that you have drawn some conclusions about me and have used this thread to air them in a personally critical manner. I have requested time and again to keep to the subject of the discussion but you keep on making my use of the forum the subject. There is no paranoia, just your responses and how they read

    Lets address your concerns from the start so anyone who has an inclination to participate in a forum environment in a manner that is of help to those seeking any aspect of any knowledge

    http://www.boatdesign.net/forums/boat-design/comfy-ride-25-knots-50758.html
    This is where it started. I am looking for opinions on what it takes to be comfortable going at a good speed through bad chop unlike the current boats that I travel on that pound

    Here I learn about displacement cats built for performance like the Supercats from Africa and the Americas cup camera boat

    That is my SOR for that query. I have not asked anyone to spoon feed me or design me a boat through any underhand means. Just looking for information on what type of boat I should be looking at on a forum about boat design

    http://www.boatdesign.net/forums/boat-design/light-duty-displacement-cat-51583.html
    This in an attempt to further explore this type of boat, maybe in a smaller lighter model to have some fun in. At the moment there are no plans on the internet that I can find for a vessel like this. There are no second hand boats like this for sale in the remote north west of Fiji Islands where I am located. It is not within my means hire the services of a NA. It is within my means to play around with some experimental builds to see if I can make something that fits my needs. I also find the process very rewarding. Again I have made no attempt to get the forum to make a boat for me.

    http://www.boatdesign.net/forums/boat-design/displacement-powercat-single-40hp-51611.html

    Here I have further refined the SOR, and a target that I can aim towards. By around this stage I think I have also done the correct thing by approaching Richard Woods and inquiring about building an open version of his Skoota and the feasibility of the 40hp motor. The discussion on the forum has been helpful in that by the end of it I have learned limitations of a single motor and changed the SOR to adopt twin motors. Again I have not asked anyone to design or work out a design aspect for me. I have only asked to be pointed in the right direction

    http://www.boatdesign.net/forums/materials/expanding-foam-52076.html
    Leads to here. I am exploring expanding PU in hopes that it can take a beating. I have listed the SOR and asked for opinions on the material as I have no experience with it. Again I have only asked if I am looking in the right direction

    http://www.boatdesign.net/forums/boat-design/help-hull-weights-52092.html
    Then here, I have the type of dimensions I would like. I am asking for two bits of help. Firstly if I am doing the sums correctly, not asking for anyone to do the sums for me!

    Secondly I am asking for opinions from those that might know, how does this compare to a plywood structure. Is this an inappropriate question on a forum about making boats?

    http://www.boatdesign.net/forums/boat-design/boston-whaler-type-construction-52124.html
    Reading up on PU foam on the net I came across the Boston Whaler. Offcourse they are not going to list the cons of this process on their marketing material. As this material is a subject of interest for me, I asked here on a boat making forum about the pros and cons of this method. Is this an inappropriate type of question?
    From this discussion I have started seeing that I will be looking at a very heavy boat and also pondering on another material being HDPE which is also heavy

    http://www.boatdesign.net/forums/boat-design/sea-seesaw-52130.html
    I have been thinking about the issues so far for while and talking with other boat owners and wondering about the issues of trim with lightly built boat hulls compared to heavily built hulls. I listed a pair of examples and asked two questions. Firstly if I am working this out correctly, not asking for anyone to work this out for me Secondly I am asking for opinions on change in trim with the listed condition and some help in understanding why it is so. Is this an inappropriate question to ask?

    http://www.boatdesign.net/forums/materials/honeycomb-use-52147.html
    This is an unfamiliar building material for me so I asking if this can be used like ply on a forum about making boats. Is this an inappropriate question?

    http://www.boatdesign.net/forums/boat-design/cat-draft-52170.html
    I am playing around with drawings on a software and seeing results that defy any reason that I know off. I am asking on the forum about boat making if if I am missing something in the logic can apply or if this is likely to be a software issue. I am presenting the information I have worked on and asking for opinion, not asking for anyone to fix my errors or make things for me

    http://www.boatdesign.net/forums/boat-design/cat-draft-2-a-52182.html
    Looks to me there is some confusion as to what I might be saying in the previous question. I still want to find out if my reasoning is correct or if I am looking at a software glitch. Towards this process I have drawn a control shape and posted that and the results on the forum. Consensus is that software issue. Is this inappropriate use of the forum?

    http://www.boatdesign.net/forums/boat-design/area-volume-52217.html
    I have thot of a quick and easy cheat to work out area and volume of an object I have in mind. I have asked on the forum if this process will reveal usable data or if I am missing something. Is this an inappropriate question for this forum?


    http://www.boatdesign.net/forums/design-software/trim-52253.html
    I have asked a specific question about using a software in the forum for software. I have also asked to be pointed towards any software that may have the feature I am interested in. Is this an inappropriate quest for that forum?

    Ad Hoc, I have raised 12 topics under suitable topic tittles in a period of seven months. None of them are asking others to spoonfeed me. I have only asked if I am looking in the right direction in the work I am already doing or asked for help with anything that has stumped me. Why do you feel this is inappropriate use of the forum?
     
    Last edited: Jan 9, 2015
  5. Mr Efficiency
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    Mr Efficiency Senior Member

    I like saqa's dream boat musings. They may yet come to fruition ! Ad Hoc has laid out some "saqa bait", and the reel is screaming ! :p
     
  6. Saqa
    Joined: Oct 2013
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    Saqa Senior Member

    Too right, I am begining to get the picture what this forum is really about. Might be time to find a forum aimed at enthusiast level and leave the wonderboys to their own fine company ;)
     
  7. Mr Efficiency
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    Mr Efficiency Senior Member

    Hang around, there are plenty of real gentlemen on this site. And they have a wealth of experience you can draw from.
     
  8. FMS
    Joined: Jul 2011
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    FMS Senior Member

    LP provided a direct answer to how to calculate area and volume. Petros' reply ( and others ) to your question 5 was also something you should understand. Without a specific design you will only be able to guess at material thickness and structural weight based on other similar designs and requirements.
     
  9. Saqa
    Joined: Oct 2013
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    Saqa Senior Member

    Thats correct FMS, I tried again with freeship after reading what LP had to say and found the data I was after, I posted the results there on page 1. Everything after that has been addressed to Ad Hoc's claim that the process is not even close to generating usable data and addressing his claims that I am making an inappropriate use of the forum

    Any way thanks guys for helping with some of these things. I think I understand enough to draw a hull that might do the trick and I have the experience to end up with a structurally sound item by rigorous testing and rebuilding. Will show what I have settled on soon. As for the question of trim changes with shifting ballast, I may not have the stability calculation ability that Ad Hoc is on about but I can make models and scale things and test these things physically
     
  10. TANSL
    Joined: Sep 2011
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    Location: Spain

    TANSL Senior Member

    As for the question of trim changes : In the stability calculations in a given loading condition, there are two stages. The first is to calculate the equilibrium waterline, the second is to check that the ship complies with the requirements of stability that the rules require for each type of vessel. I think the first stage, which is what worries you right now, can you study it with freeship. Simply raise a table, for example in Excel, which you must itemize weights that make up the total displacement of the vessel and the position of their centers of gravity. One of those weights will be the ballast; changing only the position of the ballast can you study various "load conditions". For each of them, I think freeship, will calculate equilibrium position of the ship, ie, inter alia, the trim.
    It is a study, not simple, of forces and moments that do not require deep knowledge of stability.
     
  11. Saqa
    Joined: Oct 2013
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    Saqa Senior Member

    Thanks mate, I think I can manage something like that. I already have made an Excel file with my items and weights. I will add another column for position. I take it you mean position away from stem, the way bulkhead locations are written?

    I have also come across a ballast feature in the other software that I am using. It gives two options. Firstly selecting seated/standing/laying human figures and you can select height and weight of each person. You can move them around the drawing of the hull. Secondly it a place for selecting a specified ballast and its location away from stem. I have tried using those two features but neither seem to work. I have written to the author asking how to use those features. Will post back here after I hear from him and if they work it might be helpful to others who are at enthusiast level
     
  12. TANSL
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    TANSL Senior Member

    You can take the distances from the point you like better. Typically taking the distances from the aft perpendicular. In any case, consider how your program takes distances when calculated, for example, the longitudinal center of buoyancy. The origin of the distances should be the same in all cases.
     
  13. Saqa
    Joined: Oct 2013
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    Saqa Senior Member

    LP, I think I have finally figured out what you were trying to tell me about layers. I can see the area where area and weight for each plate is displayed when density and thickness is added for that plate. I was trying to find where totals are displayed but this is good enough, I can add them up in excel

    Lol I wish it were that easy to find the mass of each frame too!

    TANSL, got it, thanks
     
  14. Saqa
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    Saqa Senior Member

    Update
    For the hull that I am currently working on in freeship, adding the displayed results for surface area is 22.428m^2 and sinking the hull results in 22.339m^2

    The results are off by 0.089m2 but I will call that usuable. Thanks guys for pointing me in the right direction so I could work it out for myself

    Currently I have 123kg shell weight per hull

    I have some confidence now when I draw both hulls and bridgedeck that I can just sink it and quickly read the wetted area. Instead of having to enter data for each of those plates and adding them up and what not every time I add more plates as I make changes to the drawing in the near future as I play with the design

    Once I have settled on a drawing then I can input individual plates in layers to make everything neat

    Now I am going to use the volume displaced result and find the approximate weight of the 'solid' foam core and add that to the shell weight to find the hull weight

    Edit, using 4lb density pourable foam core weight is 215kg + 123kg 6mm HDPE shell weight = 338kg for each pontoon
    Looks like I am getting there :)
     
    Last edited: Jan 9, 2015

  15. michael pierzga
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    michael pierzga Senior Member

    Careful calculation of Area and Volume is what makes for a good looking beer.

    Just thought Id mention it.

    Hope it helps..........

    [​IMG]
    imag
     
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