What would be a good computer drafting program for ship design etc?

--
Thank You,
Freddie L. Richard

Several helpful responses assume you want to design hull shapes, but you
didn't mention your particular interest or skill/experience level. I'll
pass on my own experience coming from a different angle in case it's
relavent.

Many times you want to simply lay out furniture, hatch details,
plumbing, technical drawings of things such as layups, deck fitting
placement, etc. For this a "traditional" CAD programs, 3D or even 2D, is
the tool of choice. In many ways, the more powerful the tool, the harder
it is to control and get results. (Cast your mind back to when you tried
to use Styles in Microsoft Word...)

I have used an old version of a 2D CAD program from Intergraph called
Smartsketch for documenting many contruction tasks, and it continues to
be most adequet. It's good points at the time I got it (4 or 5 years
ago) included powerful user interface features such as moveable origin,
automatic double lines, automatic connecting lines, automatic
dimensioning, and quite powerful parametric symbols. I extremely happy
(after several months looking) to find a user interface that was
understandable, accessible, and addressed immediate needs. It still took
me more than 40 hours work with the program before I got to the point of
"just doing" a drawing (I was, and am, not a draftsman).

For recording specific details and printing them for use in working with
others, less is more. Smartsketch is now in version 5 (I have v3). The
others that looked very good and were within reach for a "shade tree"
drafter included Vectorworks (Mac and PC), Vellum (with 3D as well, but
much more expensive). I have heard that AutoCad finally got it close to
right with their basic user interface, so their low-end "home" version
might also be a good tool; at the time I was looking they had an
impossibly dense interface.

CAD provides an extremely complex set of tools, and most people will
probably not be able to use anything except the most basic software, and
then only if it has a clean and accessible user interface and top notch
tutorials and support. If you haven't used CAD before and want it for
technical drawing like I did, check out one (or more) of the programs I
mentioned above and don't crash and burn trying to decipher a "free"
offering, or drown in the maze of one of the super programs. I think the
other poster's link to the Nurbs article makes some similar points
regarding the hull design programs - there's a huge amount to learn and
it takes real work to get decent results.

Rufus


Freddie Richard wrote:

What would be a good computer drafting program for ship design etc?

--
Thank You,
Freddie L. Richard

Rufus has some good points there.
I happen to work with CAD programs (you have to make a living somehow)
and while some are better than others, they all have a learning period.
I can "read and write" with various CAD programs, but for projects at
home (and even initial designs at work) I very often use pad and pencil.
For initial design it is very fast and cheap, provided you have an idea
what you want to accomplish.
If you have no idea what you want to accomplish, even the best software
won't help you.
For occasional use CAD programs are too cumbersome and expensive,
thinking about things like AutoCad (very user unfriendly, and in my
opinion not much better than a drawing board), Solidworks (no Nurbs
splines), CadKey (Silly file structuring), I would say:
if you are not going to use it very frequently, don't bother.
You can also do a websearch, there are a few free cad or design programs
available, can't remember any right now, but I know they are there,
because I have tried a few a while ago.
Can give you a feel for the frustration of an expensive CAD program...

So, here is my plea for the pad and pencil from the dollarstore for
Number One Design Tool, lol :-)

Marty

Rufus wrote:
Several helpful responses assume you want to design hull shapes, but you
didn't mention your particular interest or skill/experience level. I'll
pass on my own experience coming from a different angle in case it's
relavent.

Many times you want to simply lay out furniture, hatch details,
plumbing, technical drawings of things such as layups, deck fitting
placement, etc. For this a "traditional" CAD programs, 3D or even 2D, is
the tool of choice. In many ways, the more powerful the tool, the harder
it is to control and get results. (Cast your mind back to when you tried
to use Styles in Microsoft Word...)

I have used an old version of a 2D CAD program from Intergraph called
Smartsketch for documenting many contruction tasks, and it continues to
be most adequet. It's good points at the time I got it (4 or 5 years
ago) included powerful user interface features such as moveable origin,
automatic double lines, automatic connecting lines, automatic
dimensioning, and quite powerful parametric symbols. I extremely happy
(after several months looking) to find a user interface that was
understandable, accessible, and addressed immediate needs. It still took
me more than 40 hours work with the program before I got to the point of
"just doing" a drawing (I was, and am, not a draftsman).

For recording specific details and printing them for use in working with
others, less is more. Smartsketch is now in version 5 (I have v3). The
others that looked very good and were within reach for a "shade tree"
drafter included Vectorworks (Mac and PC), Vellum (with 3D as well, but
much more expensive). I have heard that AutoCad finally got it close to
right with their basic user interface, so their low-end "home" version
might also be a good tool; at the time I was looking they had an
impossibly dense interface.

CAD provides an extremely complex set of tools, and most people will
probably not be able to use anything except the most basic software, and
then only if it has a clean and accessible user interface and top notch
tutorials and support. If you haven't used CAD before and want it for
technical drawing like I did, check out one (or more) of the programs I
mentioned above and don't crash and burn trying to decipher a "free"
offering, or drown in the maze of one of the super programs. I think the
other poster's link to the Nurbs article makes some similar points
regarding the hull design programs - there's a huge amount to learn and
it takes real work to get decent results.

Rufus



Freddie Richard wrote:

What would be a good computer drafting program for ship design etc?

--
Thank You,
Freddie L. Richard

I agree and disagree completely.

If you're going to use CAD (or any complex computer program), you have to
use it often enough so you remember all the "normal" commands and almost
never open the manual or go to the Help. Otherwise, as Marty says, you're
better off with pad and pencil.

With that said, I find CAD essential. I draw everything, wood, metal,
wiring diagrams, the whole boat. I find it saves mistakes, particularly
when you're figuring plywood sizes net of rabbets in expensive material, but
also in visualization. When I make a part, I print it full size on the
laser printer and make the piece from that -- some lasers are good at actual
size work, some require a little fiddling of the scale to get an actual size
drawing.

I don't do hull calculations -- mostly I'm working with existing hulls --
but I do draw hulls as a series of planes from the offsets so I can see
exactly what will and won't fit at a given height above baseline. AutoCAD
scripts for this are easy to do in Excel -- I can't imagine entering 3D
planes point by point. Here's Fintry, done this way:
http://www.mvfintry.com/pix/bowqtr800.png

The downside is that there's a steep learning and library curve. I've been
using AutoCAD since 1985. As a result, I'm a competent 3D AutoCAD user. I
have hundreds of boat parts drawn in 3D, so I can pull most things from my
library.

I also have my own custom menus, so I have exactly what I need on the
menubar and toolbar. The most important of the customizations, I think, are
controlling Views, Snap and Layers.

The big advantage comes in doing the sort of thing we're doing now with
Fintry -- should we put two showers in the master and guest bathrooms in the
#2 hold, or share them? Where is the galley and dining area going? A sketch
won't do it, because you're dealing with inches. I find it very fast to
push around pieces -- shower pan, vanity, toilet, doors (my library
furniture is all drawn with light gray lines showing the clearance required
for use) and make this decision.

And, finally, when we're done, we have complete, as-built, drawings. This
isn't important for a small boat, but for a boat with complex systems, it's
significant.


--
Jim Woodward
www.mvFintry.com


..
"Marty" wrote in message
news
Rufus has some good points there.
I happen to work with CAD programs (you have to make a living somehow)
and while some are better than others, they all have a learning period.
I can "read and write" with various CAD programs, but for projects at
home (and even initial designs at work) I very often use pad and pencil.
For initial design it is very fast and cheap, provided you have an idea
what you want to accomplish.
If you have no idea what you want to accomplish, even the best software
won't help you.
For occasional use CAD programs are too cumbersome and expensive,
thinking about things like AutoCad (very user unfriendly, and in my
opinion not much better than a drawing board), Solidworks (no Nurbs
splines), CadKey (Silly file structuring), I would say:
if you are not going to use it very frequently, don't bother.
You can also do a websearch, there are a few free cad or design programs
available, can't remember any right now, but I know they are there,
because I have tried a few a while ago.
Can give you a feel for the frustration of an expensive CAD program...

So, here is my plea for the pad and pencil from the dollarstore for
Number One Design Tool, lol :-)

Marty

Rufus wrote:
Several helpful responses assume you want to design hull shapes, but you
didn't mention your particular interest or skill/experience level. I'll
pass on my own experience coming from a different angle in case it's
relavent.

Many times you want to simply lay out furniture, hatch details,
plumbing, technical drawings of things such as layups, deck fitting
placement, etc. For this a "traditional" CAD programs, 3D or even 2D, is
the tool of choice. In many ways, the more powerful the tool, the harder
it is to control and get results. (Cast your mind back to when you tried
to use Styles in Microsoft Word...)

I have used an old version of a 2D CAD program from Intergraph called
Smartsketch for documenting many contruction tasks, and it continues to
be most adequet. It's good points at the time I got it (4 or 5 years
ago) included powerful user interface features such as moveable origin,
automatic double lines, automatic connecting lines, automatic
dimensioning, and quite powerful parametric symbols. I extremely happy
(after several months looking) to find a user interface that was
understandable, accessible, and addressed immediate needs. It still took
me more than 40 hours work with the program before I got to the point of
"just doing" a drawing (I was, and am, not a draftsman).

For recording specific details and printing them for use in working with
others, less is more. Smartsketch is now in version 5 (I have v3). The
others that looked very good and were within reach for a "shade tree"
drafter included Vectorworks (Mac and PC), Vellum (with 3D as well, but
much more expensive). I have heard that AutoCad finally got it close to
right with their basic user interface, so their low-end "home" version
might also be a good tool; at the time I was looking they had an
impossibly dense interface.

CAD provides an extremely complex set of tools, and most people will
probably not be able to use anything except the most basic software, and
then only if it has a clean and accessible user interface and top notch
tutorials and support. If you haven't used CAD before and want it for
technical drawing like I did, check out one (or more) of the programs I
mentioned above and don't crash and burn trying to decipher a "free"
offering, or drown in the maze of one of the super programs. I think the
other poster's link to the Nurbs article makes some similar points
regarding the hull design programs - there's a huge amount to learn and
it takes real work to get decent results.

Rufus



Freddie Richard wrote:

What would be a good computer drafting program for ship design etc?

--
Thank You,
Freddie L. Richard

On Thu, 13 Nov 2003 20:48:05 -0500, Marty
wrote something
.......and in reply I say!:


For occasional use CAD programs are too cumbersome and expensive,
thinking about things like AutoCad (very user unfriendly, and in my
opinion not much better than a drawing board)

Hear here!

, Solidworks (no Nurbs
splines), CadKey (Silly file structuring), I would say:
if you are not going to use it very frequently, don't bother.


Here I disagree. For sketching try DeltaCad. Only 2d, and it hath its
limits, but so bloody simple that I actually use it instead of a paper
and pencil. I can remember every action from session to session even
after weeks, and I just sit down and start using it. I have found no
other CAD programmes that come near being able to allow this. It may
not suuit this particular use as requested, but is easy to learn and
remember.


Shareware and cheap. Demo is available.

http://www.dcad.com
************************************************** ****************************************
I wander in the wilderness, stubbing my toes and barking my shins on the unknown obstacles.
It is better than treading the path that I knew
Nick White --- HEAD:Hertz Music

remove ns from my header address to reply via email

!!
")
_/ )
( )
_//- \__/

On Sat, 15 Nov 2003 07:38:06 +0800, Old Nick
wrote:

TurboCad ment to be a great program for its price...

I only mentioned some CAD software I have actually worked with for a
living, of which Solidworks is my favorite, but very expensive.
I like Jim Woodwards way of using AutoCad. Yes, it is possible, Jim, and
I liked your Fintry hull, pretty cool. And just in passing you gave me a
great hint by mentioning excel for the planes etc, I should be able to
do this in Solidworks as well and probably quicker...

AutoCad is also very expensive, and AutoCad LT does not do 3d as far as
I know.
But you might be able to find an educational version of AutoCad or
Soldworks somewhere, if you want to go that way. Solidworks is a lot
easier to learn, I can get new people up to basics in a week, or less if
I have time.

I don't know SolidWorks at all. I have heard good things about TurboCAD and
might be using it if I hadn't a lot of history with AutoCAD. I tried
IntelliCAD at one point and found it satisfactory, but buggy in a few
annoying places.

As for using Excel to generate Scripts, a long time ago (in a galaxy far far
away) I started to enter hull planes from a table of offsets by hand and
realized that I would have to enter each point four times (for most planes)
and decided there had to be a better way.

In Excel, you can also do things like calculate and prepare to draw the
horizontal planes of decks and tank tops, so that you see how much area you
actually have at any given level.

Unfortunately, for those building a new hull, my planes method doesn't have
the advantage of actually computing accurate offsets. The reason most boats
were lofted full size was that offsets pulled from a scale drawing were not
accurate enough to build a full size hull that was fair. By actually
drawing the hull in CAD, you can get accurate offsets and cut the molds
without lofting. This can be a big time saving.



--
Jim Woodward
www.mvFintry.com


..


"Marty" wrote in message
...
I only mentioned some CAD software I have actually worked with for a
living, of which Solidworks is my favorite, but very expensive.
I like Jim Woodwards way of using AutoCad. Yes, it is possible, Jim, and
I liked your Fintry hull, pretty cool. And just in passing you gave me a
great hint by mentioning excel for the planes etc, I should be able to
do this in Solidworks as well and probably quicker...

AutoCad is also very expensive, and AutoCad LT does not do 3d as far as
I know.
But you might be able to find an educational version of AutoCad or
Soldworks somewhere, if you want to go that way. Solidworks is a lot
easier to learn, I can get new people up to basics in a week, or less if
I have time.

Jim,
Great hull graphic! But out of curiosity...
Generating points for Fintry's hull design in Excel, did you start with
calculations for the transversals? And if so, what family of curves
would evolve so smoothly from the forward V to the mid and aft U
sections? It kind of looks like you morphed a tangent into a secant.
But how do you do that in calcs? Or did you start with the
longitudinals and then somehow connect the dots for the frames?
I'm playing with an Excel development of a one-off hull design and have
a pretty good layout using all secant frames, but a tangent in the bow
would give me just the right entry...if only I could figure out the
transition.
Any thoughts would be greatly appreciated.
boat_dreams

Jim Woodward wrote:
...
If you're going to use CAD (or any complex computer program), you have to
... Here's Fintry, done this way:
http://www.mvfintry.com/pix/bowqtr800.png

Sorry, nothing so sophisticated. I have reams of documentation for the
Fleet Tenders, including a traditional table of offsets. In the Excel
spreadsheet, I have a row for each station (11 stations 0-10 plus some half
stations). The f&a location of each station appears in column A, then pairs
for height and beam of each of the offsets in columns B and up.In AutoCAD, a
script contains exactly the same text as the typing needed to do the same
thing, so you have to pay attention to constructing the command with the
points in the right order. It's basically a matter of creating a command of
the form
3dface x1,y1,z1 x2,y2,z2 x3,y3,z3 x4,y4,z4
(extra spaces inserted for emphasis -- one only is valid) Assuming x is
vertical, y is p&s, and z is f&a, then z1=z2, z3=z4, x1=x4, and x2=x3.
(Just so I don't confuse, these are not Excel RC references, but the actual
locations of the corners of the face.)

So this ends up with creating the first plane Of course, you have to
convert the numbers to text and put in the command and all the spaces and
commas. Then it's just copying in the usual Excel fashion to create all the
rest, paying attention to relative and absolute references, and so forth.

There's a certain amount of slogging needed to create the first plane and
get all the references right, but considering that it's about 350-400
points, each of which has to be entered four times (once for each plane in
which it appears, except at the ends), I can't imagine doing it by hand.

Creating a fair and good looking hull, as you're trying to do, is much
harder. Maybe, though, if you use Excel to do the math, this will help you
visualize it.

Of course the CAD packages have the advantage that the drawing that this png
http://www.mvfintry.com/pix/bowqtr800.png
was created from is a real 3d drawing, so you can rotate it in all three
planes to look at it from various angles. This is the same drawing, rotated:
http://www.mvfintry.com/pix/sternqtr800.png
and this is essentially the same, with half the hull erased on each side:
http://www.mvfintry.com/pix/flines800.png
so that it shows the traditional sections.

I will probably get around to putting up some of these on the site in .dwf
format, which is AutoCAD's 3d answer to PDF that can be viewed with
AutoCAD's free WHIP plug-in.

--
Jim Woodward
www.mvFintry.com


..
"boatdreams" wrote in message
...
Jim,
Great hull graphic! But out of curiosity...
Generating points for Fintry's hull design in Excel, did you start with
calculations for the transversals? And if so, what family of curves
would evolve so smoothly from the forward V to the mid and aft U
sections? It kind of looks like you morphed a tangent into a secant.
But how do you do that in calcs? Or did you start with the
longitudinals and then somehow connect the dots for the frames?
I'm playing with an Excel development of a one-off hull design and have
a pretty good layout using all secant frames, but a tangent in the bow
would give me just the right entry...if only I could figure out the
transition.
Any thoughts would be greatly appreciated.
boat_dreams

Jim Woodward wrote:
...
If you're going to use CAD (or any complex computer program), you have
to
... Here's Fintry, done this way:
http://www.mvfintry.com/pix/bowqtr800.png