Hulldesigner

 赫尔斯是一个伟大的计划。给了我几个小时的乐趣,并帮助我加深了对船只的了解,在进一步了解之前,我要感谢其开发商格雷格·卡尔森(Gregg Carlson)免费提供。

本教程将引导您完成通用的11ft干燥小艇的设计过程,以说明赫尔斯的特点。

 

软件很老,但是有很多样例。可以下载参考

下载:kayacool.com/storage/hulls.zip

 

在我看来,第一步是检查你感兴趣的船体是否还没有被绘制出来,并且以Hulls格式* .hul。你可能会惊讶于Gregg所说的灵感名单,其中包括一个柔软的胶合板激光相机,以及一个以“Derby”为名的Munroe白鹭。还有我自己的小集合在http://home.clara.net/gmatkin/design.htm。

如果已经完成,你可以节省自己的时间不必要的努力 - 除非当然像我一样,你喜欢绘制船体!

如果它不存在,您很有可能会找到类似的东西,您可以将其用作起点 - 将新数字放入现有的和类似的偏移表远比从头开始更容易,至少从头开始。

通过“相似”,我的意思是具有相同数量的中国人,同样的弓和尾巴。例如,如果你想用一个平底和两个河水画一个11英尺的小艇,你可能希望从我的一幅图纸7ft10in.hul(如上图)开始,你应该可以轻松地从我的网页区域使用以下URL:

http://home.clara.net/gmatkin/drawings.htm 这个文件是一个很好的开始,尽管它比我们在这里开发的形状更短,更为重要。

使用Hulls以通常的方式打开此文件,为文件提供一个新的名称,并将其保存,以避免您可能重写原始文件的可能性。当我为了写这个替代导师的目的,我打电话给我的11ft.hul。

接下来的任务是将图纸延伸到11英尺或132英寸。使用“计算”​​菜单在“船体”中进行了简单的设置:

计算> Rescale> Length Overall(全部更改)

输入132英寸的图形,并返回。结果将与以前完全一样,因为在图形的给定尺寸增加的情况下,比例没有任何变化,并且程序将其与以前一样适用于可用的屏幕空间。

我们现在可能需要改变我们的小艇的比例,因为试验和测试的规则规定了梁和干舷。在这一点上,我转向一本由John Teale编写的有用小册子“如何设计小船”的图表,并由Adlard Coles Nautical出版。(约翰·泰勒也是一位经常和有趣的英国“经典船”杂志的贡献者。)

据Teale先生说,这个水槽的合理梁将大约在4英尺6英寸左右,假设水线长度只有11英尺。所以,因此,现在我们做了我们的水槽54in。再次转到“计算”菜单:

计算> Rescale>最大光束>

并输入图27in以产生54in的总最大光束。你会注意到,这使得计划的小艇稍微不那么光滑。

现在是时候想到这个愚蠢的干舷图。在这里Teale先生建议一个1ft7in的数字。但这一次,我们不能简单地重新调整最大高度,因为整个事情都会改变船只的水位。我的猜测是,这艘船的重量约为100磅(这纯粹是纯粹而又简单地在另一艘类似的针迹和胶带上的船上,但你可以稍后查看数字),而且说,每个人的重量为200磅的三个大人,我们很快来到一个巨大的位移数字700lb。

点击顶部的左边视图将给你一个沿着弓到船尾的视线。再次使用“计算”​​菜单,输入700lbs:

计算>位移>

你会观察到水位上升到刚刚接吻中国。为了在通过水流时保持波浪和一般的震撼最小化,我已经看到,确定水线在设计负荷下不会超过水线是明智的。我认为作家特别指的是特别是强力的小船,但我怀疑按照同样的规则,这里不会有任何伤害。

我们不能前进调整弓干干舷,因为我可以看到一个会对我们刚刚看到的排水量结果产生重大影响的问题:艉板的下半部分是在水下,会导致浪费动荡的动荡。

所以我会开始努力解决这个问题,再看看这个严厉的观点。选择表示船尾框架的蓝线,左键单击船体的最下方,将其向上拉至700lb的水线。

(尝试不要双击,因为Hulls会要求您键入新的X,Y和Z坐标,如果发生这种情况,请勿单击取消 - 这使得软件认为您的意思是X,Y和Z都为零并立即将您的合理绘图变成废话,如果发生这种情况,请回到上次保存的版本,我相信格雷格会很快就把这个小问题放在正确的位置,如果在阅读之前还没有这样做的话)

还提高了屏幕左侧的点,船的中心线与船体的平坦底部相遇。底部必须从前到后弯曲,但是由于胶合板不会被迫采取复合的“折磨”曲线,所以让我们保持简单的方法是保持底部平坦。

然后点击侧视图。坦白说,我们已经形成了一个丑陋的水下形状,所以必须考虑在第三个框架上提高底线。为了补偿bouyancy的损失,并且鉴于我们需要这个小艇有效运载700lbs,我会稍稍在船尾和第三个框架上加宽船体的身体。用于舷外和/或承载大负载的船只在任何情况下都必须具有宽的船尾。

现在让我们来看看那个弓的干舷图。从严厉的观点来看,我发现在我的绘图中,水位在7.5in,而最大高度(弓)为32.3in(尽管现在你的绘画会有所不同,而且越来越多的是你自己的!) 。

从另一个减去一个我得到一个24.8in的干舷数字,而从约翰·泰勒的图表,我真的在寻找约19in。现在,你可以选择一个特别高的弓 - 无论我去哪里,我看到那些无耻地打破了泰勒先生的规则的船只,而且有一些流行的设计,高弓,以应付粗糙的水域。不过,我尊重泰勒先生的判断,我认为我会按照这本书重新调整最大高度。我会通过将最大高度降低5.8in来实现(即,旧的干舷图减少新的)。显然,这将重新缩小船上的每个垂直维度,但是让我们来看看我们的感受。你现在可以预期的是:

计算> Rescale>最大高度>

在我的图纸中,我插入一个新的最大高度26.4,然后再次查看位移情况,要求软件重新计算700磅的水线。好消息是,我对这艘船的整体形式在许多方面仍然感到高兴,但坏消息是,我仍然有一个严重的水在水中,水线现在高于中国水平。我现在应该怎么做?

我可以看到至少有三个选择:

我可以认为这些事情并不重要,什么都不做。没关系,只要我不想像这艘船像泰晤士河小船一样排队。

我可以在水线上增加梁,注意从弓到船尾产生甜美的曲线。从约翰·特雷(John Teale)的书中,我收集到的最大光束通常是水线光束的1.1到1.2倍,但像这样一条小负载的水槽可能会被破坏。 我可以增加船的总长度,比如说六寸。 最后,我可以选择从Teale先生的书中打破另一个规则,并扩大船体,再次使用Rescale最大光束。 在这种情况下,我选择后一种选择(我做出了正确的选择吗?谁知道?),并发现6号车宽阔的船减少了我与中国人和艉板的关系。记住,要扩大6in的船,你只需要添加3in到Rescale Beam图。

我也在每一帧从弓到尾稍微加宽平底。位移计算说,我还在水中有一些横桁和水獭,但是现在我准备合理化了,说可能不会经常携带三个200lb的成年人。

现在看看边和平面图。侧视图现在显示出我绝对不太在意的一面。知道一个甜蜜的纯粹通常可以通过确保它的长度的三分之一的直线是直线,到达最小的一半的中间标记,平坦了一点,然后可爱地上升到船尾。小心翼翼的一段时间,直到它看起来很好,但请记住,这样一个小小的空气需要有一个健康数量的干舷。

在我的绘画的情况下,我也有点不高兴关于bouyancy的中心,这是从茎到尾部的一半,我知道约翰·泰勒说应该是一点点这一点。这一次,我点击了平面图,将第二,第三和第四个框架稍微移向船尾。这也将使弓部更容易制造,因为帘布层不必如此锋利地弯曲。

我还进一步拓宽了平底和相邻的中间线,以产生一套曲线,再次看到底部曲线的方式。我已经读过Uffa Fox,并且明白,给这艘船有一个很好的刨平机会(有一个外在的,显然!),我已经确定了它的“胸部”的最深部分是弓的三分之一。我通过稍微加深第二帧来做到这一点。这可能是最好的做法在严厉的观点。从其他观点来看,要确保曲线从各个角度继续保持公平。

现在是时候再看看流离失所。我看到什么 在水中还有一丝trans子,Dammit!

现在这艘船的船尾有一个可爱的斜坡。通过平衡它,我可能只是把艉板从水中拿出来。这一次,我们使用偏移表来解决问题。我转到数据菜单,然后单击偏移表。这看起来不像传统的偏移表,但并不是太难以遵循 - 只要记住,X是你所看到的一半的光束,Y是高度,Z是距离杆的距离。

在这种情况下,我可以通过确定船尾的Z坐标全部为132in,然后点击“完成”按钮,从而使船尾伸直。从侧面看,我可以看到,一个小小的调整将使艉板完全脱离水面,仍然产生一个公平的曲线。所以我把船尾和下一个小河的平底移动一下。这变得越来越好 现在,位移曲线告诉我,水线上升到艉板的最底部,水中最上方只有很小的数量。大。但现在bouyancy的中心再次向前迈进。哈! - 这意味着在船尾部的框架中的梁的更多的调整。所以我这样做 我从来没有说过这是一个简单的练习!

在这一点上,我的好奇心让我看看这艘船的稳定性。但是在这里我必须发出一个小小的警告 - 在执行此操作之前将Auto-spline Chines设置为ON,因为在我的PC上,可爱的旧Hulls完全破解并崩溃,而不让您保存。我已经失去了几张图纸。

考虑到它的形式,这个船体应该是高度稳定的,我可以通过在“计算”菜单上的“跟踪”来找出确切的稳定性。这告诉我,在15度的脚跟,其重量在船上平均分布,我的小船将有一个令人印象深刻的383英尺磅的正确的时刻,但这是一个相当学术的人物在这艘船的大小,因为装修将取决于乘客的移动需要。

最后,如果我们有兴趣制作这个dink帆,我们可能会考虑增加侧甲板,以提供舒适的坐姿。我们可以通过添加一个chine来做到这一点。

再次,我们使用偏移表。我使用Chn滑块来添加第五个chine,然后点击偏移表按钮。首先,我在每个框架中使Z坐标与其姐妹们的框架相同。然后,我使第五个中心的高度(Y)与每帧的第四个高度相同。如果我想要的话,我可以稍后加一个外倾。然后,在每个帧处,使宽度(X)在每帧缩小三英寸处。(除了弓,当然!)

我也使这条茎的线条躺在船上,形成一个小甲板区域。如果我将最后一条偏离了弓箭的20厘米左右偏移,我得到一个结果,我认为开始看起来很明智,但是这使得甲板的部分非常狭窄。我通过调整第二个框架的第五个chine来解决这个问题。


在这一点上,当然,我真的不知道你的小艇的细节,这自然会与我的不同。然而,从我看来,我可以看到,11ft可能太短了,因为一个真正的干燥小艇设计为承载一个这样大的负载。如果我再次开始,我可能会选择一个常规的婴儿车,或者在弓上有一个窄的横梁。从我所看到的,我也建议,如果你的意思是在任何地方排列或拖动这个水槽,这将是值得给它一个skeg,将有助于跟踪相当好 - 究竟应该是多大的是一个审判的问题并且错误,但从其他船只看这个大小,面积约一平方英尺,给或采取一点,不应该太错了。使它从船尾跑步,从船尾三英尺处,并以船尾结束,

三维建模随时按下CD按钮,可以使用屏幕顶部的X,Y和Z按钮进行三维视图的移动。此外,如果您的HTML浏览器具有VRML加载项,则按VRML按钮可生成该格式的三维对象。我已经尝试了,但是在我的90megahertz计算机上,40毫米的ram是非常非常慢的,我现在不打扰,因为CD按钮的线框视图效果很好。

开发面板这可能是赫尔斯最令人印象深刻的功能。转到文件保存,并查看对话框。在那里你会发现有用的按钮的按钮,以及输入的标准。最多可以放置八个您喜欢的结构框架。我建议我们的11ft小艇,你可能会选择三到四个,并将它们相当均匀地分配。其中一些将轻松地作为内置bouyancy的墙壁。

如果你改变你的船体模型并希望嵌套一套新的开发的中文,就像你可能会做的,例如,如果你想将一个整个工艺的面板放在有限的一叠薄层上,似乎有助于保存新表单,并关闭Hulls,然后重新打开它和您的文件,以确保您正在嵌套正确的面板。

DXF输出设备在对话窗体中,我也可以点击扩展,DXF和文本。当按下保存时,这些将分别告诉软件将开发的面板以CAD标准.dxf格式保存,如果您有一个3-D CAD软件包(将在计划中显示为图形),则会以三维生成.dxf图像并以2-D包装提升),并输出一组坐标,可以在使用板条铺展之前将其标记在单板上,然后切割 - 至少比正确的放样更好!

这里我要补充一个重要的警告。赫尔斯所生产的坐标在造船方面是传统的。然而,赫尔斯有一个错误,产生了像12-8这样的坐标。解释为13-0。有一天这可能是固定的; 直到那时,不难生活,但你必须了解它! .dxf输出的一个非常重要的用途是确保复杂多线工艺的船尾和弓形横梁真的是平坦的。从Hulls输出文件,使用CAD软件包进行检查,如果需要,请返回并修改。当然,你可以通过毕达哥拉斯几何来完成所有的事情 - 如果你喜欢用可以更好的方式修复的小事情。

按钮模式>嵌套生成一个方便的小工具,可以将开发的工作表嵌入最多五个8×4ft层,并且此处“保存”会生成您之前要求的坐标。

输出偏移我还没有尝试过,但是我收集可以输出使用Hull产生的偏移量的ASCII文件。您安装通用/文本打印机驱动程序。然后,选择我的电脑/打印机 - 然后单击添加打印机。选择GENERIC并安装驱动程序时,选择打印文件选项。要使用,只需右键单击GENERIC / TEXT打印机图标,然后在启动Hull之前选择默认值,并将偏移量保存到您选择的文件中。当然,在退出Hull之后,您需要右键单击常规打印机并恢复其原始默认设置。

赫尔斯还能做什么?如果你有这么远,我真的认为你会发现其余的Hulls的功能是不言自明的。试试吧!

祝你好运。

Gavin Atkin,2001年9月我不承诺支持赫尔斯,但我很感谢使用本教程时遇到的任何困难。我的电子邮件地址是该邮件地址已受到反垃圾邮件插件保护。要显示它需要在浏览器中启用 JavaScript。

 

 

 

 

以下是原文。

Gregg Carlson's Hulls program

an alternative tutorial

 

The 7ft10in hull

Return to boat design home page

Hulls is a great program. It has given me hours of fun and helped to deepen my understanding of boats, and before going any further, I would like to thank its developer, Gregg Carlson, for making it freely available.

This tutorial takes you through part of a design process for a general purpose 11ft stem dinghy in order to illustrate Hulls' features.

To my mind, the first step is to check that the hull you are interested in has not already been drawn and in the Hulls format, *.hul. You may be surprised at what you can find in what Gregg calls his inspiration list, which includes a soft-chine plywood Laser-alike, and a Munroe Egret, which goes by the filename of 'Derby'. There's also my own small collection at http://home.clara.net/gmatkin/design.htm .

If it has already been done, you could save yourself hours of needless effort - unless of course, like me, you enjoy drawing boat hulls!

If it doesn't already exist, you are very likely to find something similar, which you can use as a starting off point - putting new numbers into an existing and similar offset table is far easier than starting from scratch, at least to begin with.

By 'similar', I mean something with the same number of chines, and the same sort of bows and stern. For example, if you wished to draw an 11ft dinghy with a flat bottom and two chines, you might wish to start with one of my drawings '7ft10in.hul' (pictured above), which you should be able to pull down easily from my Web pages area using the following URL:

http://home.clara.net/gmatkin/drawings.htm This file is a good start, even though it's shorter and fatter than the shape we are setting out to develop here.

Having used Hulls to open this file in the usual way, give the file a new name and save it straightaway to avoid the possibility that you might over-write the original. When I did it for the purposes of writing this alternative tutor, I called mine 11ft.hul.

The next task is to extend the drawing to 11ft, or 132 inches. This is made easy in Hulls using the Calculations menu:

Calculations>Rescale>Length Overall (Change All)

Enter the 132in figure for 11 feet, and RETURN. The result will look exactly the same as before, for while the given dimensions of the drawing have increased, the proportions have not changed in any way and the program fits it into the available screen space as before.

We probably need now to change the proportions of our dinghy, as there are tried and tested rules governing beam and freeboard. At this point, I turn to some graphs published in a useful little book, 'How to Design a Boat' by John Teale and published by Adlard Coles Nautical. (John Teale is also a regular and interesting contributor to the superb British magazine Classic Boat.)

According to Mr Teale, a reasonable beam for this dink would be about 4ft 6in or so, presuming a waterline length of just under 11ft. So, accordingly, now we make the beam of our dink 54in. Go to the Calculations menu again:

Calculations>Rescale>Maximum Beam Only>

And enter the figure 27in to produce a total maximum beam of 54in. You'll notice that this makes the planned dinghy a little less beamy.

Now it's time to think of that bows freeboard figure. Here Mr Teale suggests a figure of 1ft7in or so. But this time we can't simply rescale the maximum height, as the whole thing turns on how much water the boat is displacing. My guess is that this boat will weigh about 100lb (this is based purely and simply on another boat of similar stitch and tape construction, but you can check the numbers later) and with, say, three adults weighing 200lb each, we quickly come to a huge-looking displacement figure of 700lb.

Clicking on the top lefthand view will give you a view along the bows to stern axis of the boat. Using the Calculations menu again, enter 700lbs:

Calculations>Displacement>

You will observe that the water level rises to just kiss the chine. In order to keep wavemaking and general fuss to a minimum when travelling through water, I have read that it is wise to make sure the waterline does not rise above the chine at the design load. I think the writer was referring to hard chine boats in particular, but I suspect following the same rule won't do any harm here.

We can't go ahead and adjust the bows freeboard yet, as I can see a problem that will materially affect the displacement results we've just been looking at: it is that the lower part of the transom is under water, and will cause wasteful turbulence as it moves.

So I would start to work on fixing that by looking again at the stern-on view. Select the blue line denoting the stern frame, left click on the lowest chine of the hull and pull it upwards to the 700lb waterline.

(Try not to double click, as Hulls will then ask you to type in new X, Y, Z co-ordinates. If this happens DO NOT click cancel - this makes the software think you mean that X, Y and Z are ALL zero and instantly turn your sensible drawing into nonsense. If it happens, go back to your last saved version. I believe that Gregg will put this minor problem right shortly, if he has not already done so by the time you read this.)

Also raise the point at the left of the screen, where the centre line of the boat meets the flat bottom of the hull. the bottom must curve front to back, but as plywood does not take kindly to being forced to take compound 'tortured' curves, let's keep things simple by keeping the bottom flat from side to side.

Then click on the side view. To be frank, we've produced an ugly underwater shape, and so will have to think about raising the bottom at the third frame as well. To compensate for the loss in bouyancy, and given that we need this dinghy to carry 700lbs efficiently, I would then widen the body of the hull at both the stern and the third frame slightly. Boats intended for use with an outboard and/or for carrying large loads have to have wide sterns in any case.

Now let's have a look at that bows freeboard figure. Again from the stern view, I find that in my drawing the water level is at 7.5in, while the overall maximum height (at the bows) is 32.3in (though by now your drawing will be different, and increasingly all your own!).

Subtracting one from the other I get a freeboard figure of 24.8in, whereas from John Teale's graphs I'm really looking for about 19in. Now, you might choose to have a particularly high bows - wherever I go I see boats that shamelessly break Mr Teale's rules, and there are popular designs that have high bows in order to cope with areas of rough water. However, I respect Mr Teale's judgement and I think I'll follow the book and rescale the maximum height. I'll do this by bringing the maximum height down by 5.8in (that is, the old freeboard figure less the new one). Obviously this will rescale every vertical dimension in the boat, but let's do it anyway and see how we feel about it. As you might now expect it's:

Calculations>Rescale>Maximum height only>

In my drawing, I insert a new maximum height of 26.4, and then look again at the displacement situation by asking the software to recalculate the waterline at 700lbs. The good news is that I'm still happy about the overall form this boat in many ways, but the bad news is that I've still got a stern that's in the water, and the waterline is now above the level of the chine. What should I do now?

There are at least three choices that I can see:

I may consider that these things don't matter too much, and do nothing. That's ok, so long as I'm not looking for this boat to row like a Thames skiff.

I could increase the beam at the waterline, taking care to produce a sweet curve from bows to stern. Again from John Teale's book I gather that maximum beam is usually 1.1 to 1.2 times the waterline beam, but in a small load-carrying dink like this rule could perhaps be broken. I could increase the overall length of the boat by, say, six inches. And, finally, I could chose to break another rule from Mr Teale's book and widen the hull, again using Rescale Maximum Beam Only. In this case, I choose the latter option (Have I made the right choice? Who knows?) and find that widening the boat by 6in overall reduces the problems I'm having with the chine and the transom. Remember that to widen the boat by 6in, you have to add only 3in to the Rescale Beam figure.

I also widen the flat bottom slightly at each frame from bows to stern. The displacement calculation says that I've still got some transom and chine in the water, but by now I'm prepared to rationalise and say that it probably won't carry three 200lb adults all that often, after all.

Now look at the side and plan views. The side view now shows me a sheer that I don't care for too much. Knowing that a sweet sheer can usually be obtained by making sure that the sheerline is straight for the first third of its length, comes to a minimum a little abaft the halfway mark, flattens out for a bit and then rises cutely up to the stern. Fiddle with it for a while until it looks good to you, but remember that a little dinghy like this will need to have a health amount of freeboard amidships.

In the case of my drawing I'm also a little unhappy about the centre of bouyancy, which is just about halfway from stem to stern, and I know that John Teale says it should be a little aft of this point. This time, I click on the plan view and move the second, third and fourth frames slightly towards the stern. This also will make the bows section far easier to make because the ply will not have to curve so sharply.

I also further widen the flat bottom and the adjacent chines to produce fair set of curves, and look again at the way the bottom curves. I have read Uffa Fox, and understand that to give this boat a fair chance of planing (with an outboard, obviously!), I have make sure that the deepest part of its 'chest' is about a third from the bows. I do this by deepening the second frame slightly. This is probably best done in the stern to stem view. Do look at it from the other views too, to ensure that the curves continue to be fair from each angle.

Now it's time to look again at displacement. What do I see? There is still a trace of transom in the water, Dammit!

Now, the stern of this boat has a cute slope. By squaring it off, I might just bring the transom out of the water. This time, let's use the offsets table to fix the problem. I go to the Data menu, and click on Offsets Table. This does not look like a traditional offset's table, but it's not too hard to follow - just remember that X is half the beam at the point you are looking at, Y is the height and Z is the distance from the stem.

In this case, I can straighten out the stern by making sure the Z co-ordinates in the stern are all 132in, and then hitting the 'Done' button. From looking at the side view, I can see that a small tweak will bring the transom out of the water altogether, and still produce a fair curve. So I move both the flat bottom at the stern and the next chine up slightly. This is getting better. Now the displacement curve tells me that the waterline rises to the very bottom of the transom, and that there's only a tiny amount to the uppermost chine in the water. Great. But now the centre of bouyancy has edged forward again. Hah! - that means more tweaking of the beams in the frames in the after part of the boat. So I do it. I never said this was a simple exercise!

At this point my curiosity leads me to look at the stability of this boat. But here I must issue a small warning - leave the Auto-spline Chines set to ON before you do this, as on my PC poor old Hulls goes completely crackers and crashes without letting you save. I have lost a few drawings that way.

Given its form, this hull should be highly stable, and I can find out exactly how stable by going to Heel on the Calculation menu. This tells me that at 15 degrees of heel, and with its weight evenly distributed about the boat, my little vessel would have an impressive-sounding righting moment of 383 foot-pounds, but this is a fairly academic figure in a boat this size, as trim will depend on the passengers moving as required.

Finally, if we were interested in making this dink sail, we might like to consider adding side decks to provide a comfortable sitting out position. We can do this by adding a chine.

Again, let's use the offsets table. I use the Chn slider bar to add a fifth chine, and then hit the offsets table button. First I make the Z co-ordinates for the fifth chine in each frame the same as its sisters lower down the frame. Then I make the height (Y) of the fifth chine the same as the height of the fourth at each frame. I can add a camber later if I want to. Then I make the width (X) at each frame three inches less than the maximum beam at each frame. (Except at the bows, of course!)

I also make the rabbet line of the stem lie back into the boat to form a small deck area. If I place the final chine offset about 20in from the bows I get a result I think is beginning to look sensible - but which but makes the deck very narrow in parts. I fix this by adjusting the fifth chine at the second frame.


By this point, of course, I don't really know the detail of your dinghy, which will naturally be different to mine. However, from looking at mine, I can see that 11ft is probably too short for a real stem dinghy designed to carry a load as large as this. If I were to start again, I would probably opt instead for a conventional pram, or something with a narrow transom at the bows. From what I have read, I would also suggest that if you mean to row or tow this dink anywhere, it would be worth giving it a skeg that would help it to track reasonably well - exactly how large it should be is a matter of trial and error but, from looking at other boats of about this size, an area of about a square foot, give or take a little, should not be too far wrong. Make it run from, say, three feet from the stern and allow it to end with the stern, round it off, and attach a metal strip for protection.

Three dimensional modelling Pressing the CD button at any time produces a three-dimensional view that can be moved around using the X, Y and Z buttons at the top of the screen. Also, if your HTML browser has a VRML add-on, pressing the VRML button produces a three-dimensional object in that format. I've tried it, but it was very, very slow on my 90megahertz computer with 40megs of ram and I don't bother now, as the wireframe view that the CD button produces works well.

Developing the panels This is possibly the most impressive feature of Hulls. Go to File Save, and take a look at the dialogue box. There you will find scads of useful buttons to press, and criteria to input. Place up to eight structural frames where you like. I suggest for our 11ft dinghy, you might like to choose three or four and distribute them reasonably evenly. Some of these will handily double as walls for built-in bouyancy.

If you change your hull model and wish to nest a new set of developed chines, as you might do if, for example, you wanted to fit the panels for a whole craft onto a limited set of sheets of ply, it seems to help to save the new form, and close Hulls and then reopen it and your file to ensure you are nesting the correct panels.

DXF output facility On the dialogue form I would also click on expansions, DXF, and text. When save is pressed, these will respectively tell the software to save the developed panels in the CAD standard .dxf format, produce a .dxf image in three dimensions if you have a 3-D CAD package (which will appear as a drawing in plan and elevation in a 2-D package), and output a set of co-ordinates that can be marked out on sheets of ply prior to being faired with a batten and then cut - at least it's better than proper lofting!.

Here I have to add an important warning. The co-ordinates that Hulls produces are in eights, as is traditional in boatbuilding. However, there's a bug in Hulls that produces co-ordinates that read like this 12-8. Interpret this as 13-0. One day this may be fixed; until then it isn't hard to live with, but you have to know about it! One very important use for the .dxf output is to ensure that stern and bows transoms of complex multi-chined craft really are flat. Output the file from Hulls, check it using your CAD package, and go back and amend it if you need to. Of course, you could do the whole thing by Pythagorean geometry - if you like fiddling about with small things that can be fixed in better ways..

Buttoning on Patterns>Nesting produces a handy gadget that allows you to nest the developed sheets onto up to five 8 by 4ft ply, and Save here produces the co-ordinates you asked for earlier.

Outputting offsets I haven't tried this, but I gather it's possible to output ASCII files of offsets produced using Hulls. You install the Generic/Text Printer Driver. Then, select MY COMPUTER/ PRINTERS - then click on ADD PRINTER. Select GENERIC and when installing the driver, select the PRINT TO FILE option. To use, simply right click on the GENERIC/TEXT printer icon and select as default before firing-up Hulls and saving the offsets to the file of your choice. Of course, after exiting Hulls you will need to right click on your usual printer and restore its original default setting.

What else can Hulls do? If you've got this far, I honestly think you'll find the rest of Hulls' features fairly self-explanatory. Try them out!

Good luck.

Gavin Atkin, September 2001 I do not undertake to support Hulls, but I would be grateful to hear of any difficulties that arise from using this tutorial. My email address is 该邮件地址已受到反垃圾邮件插件保护。要显示它需要在浏览器中启用 JavaScript。