Best Free or Low Cost Marine Design Software? (2008-09)

[ancient kayaker]

Rob: I feel your pain! Naturally you will have studied the tutorial, but FreeShip requires you to develop a feel for the program, a Delft touch as it were. Once you have that it is very powerful and fast. I don’t consider myself an expert but the following approach gets me on the right track quickly:

First of all, forget all that stuff about getting the hull to touch points; you’re playing with flexy surfaces being touched at quite different places which you have to find. Starting off right with a new hull is key; right up front you have to guess the right number of points to specify longitudinal and vertical directions, no clues are given. Too few and you will never get the shape you want, but too many is like juggling too many balls at once.

Think of bending a fairing batten around the sheer plan and midship frame curves you want. Sometimes you can do this by pushing on the batten at only 3 places, that gives a pointy kayak/canoe shape. For a shape like a circular arc 4 are needed, and you’ll need more for full stems and a near-cylindrical mid-section. If you get N(vert) and N(long) right at the get-go you have a great advantage. Never put in more than you need, that way lies madness. See the big picture at this time, not niggly details like schooner bows and wineglass transoms.

Free/DelftShip’s first guess in the vertical direction is often wildly wrong, just use the scaling tool to get it roughly right, don’t obsess about precision yet.

Next step is to get the rough look of the hull by shoving the CPs around without worrying over-much about dimensions, especially the stem, and stern or transom. It is often necessary to move a bunch of CP’s in X; remember where you had to push on the batten. This is the time to fix the sheer, rocker, profile and stations. Trying to get beam and depth exactly right using the CPs is frustrating, so once the overall shape looks right just scale the sucker in XYZ.

Now for the niggly details: extra CPs are often needed on the centerline to get a station right, and refine the stem foot and transom. By this point you are well on your way. I try to remember to run checks on hydrostatics, resistance and developments before getting too far along.

Hope the above helps, and my apologies if I just tried to show Grandma how to suck eggs.

[robherc]

mics_54:
Actually no, I did not go through the tutorial..I find that on about 99.9% of programs, I do better with them if I do NOT go though the tutorials. I'll usually try to about 10 minutes, then give up & see if I can get the feel of the program without it...otherwise it gets pitched & I find another program. It's just something about the way I learn, reading FACs and "read-me"s usually gets my brain so muddled I can't even function anymore.

AK:
Thanks for the tips. I have been able to get the overall GENERAL hull shape that I'm wanting on several attempts, just that I can't get the BWL as wide as I want w/o increasing overall Beam. I found that changing all the way from "high" to "low" in the select box filled out the lower portions of the curves a little for me, but not as much as I'd like. I'll probably have another go at it with a few more vertical CPs, or maybe I'll force my wife to sit through the tutorial, then teach me how to use it.

EDIT: Oh yeah, it probably isn't helping matters much that I'm trying to build catamaran hulls on it either, is it?

[yipster]

i see nobody gave biodesign a vote witch is a pitty
becouse its a pretty good program with ad-on's and easy to learn tutorials

[ancient kayaker]

Originally Posted by robherc

mics_54:
... I found that changing all the way from "high" to "low" in the select box ...

Not sure what you meant by that but I assume you select several control points and move them out together by clicking the arrow. There are so many control points on that figure you posted I would find it difficult to get a fair hull the shape I wanted. Generally I do not have more than 4 control points in either direction, and I would suggest starting over with a new hull with less points, using FreeShip which will deliver the plank developments, before you invest too much time on DeftShip, which (free version) won't.

I have never tried a multihull but have heard reports it is not worth the hassle except for the pretty picture; stuff like hydrostatics may come out weird if the software gets confused.

[thudpucker]

Originally Posted by yipster

i see nobody gave biodesign a vote witch is a pitty
becouse its a pretty good program with ad-on's and easy to learn tutorials

I'd try it. I'm absolutly knot headed on these design programs. It's something I want to learn so badly but I just dont seem to grasp it.
Are you vouching for the tutorials as in "Biodesign for Dummys"?

I went to biodesign.com and got into some Biological science site?

[thudpucker]

I finally got the Bio Design. I still cant find the Tutorial for it.
Any suggestions?

[Knut Sand]

Originally Posted by thudpucker

I finally got the Bio Design. I still cant find the Tutorial for it.
Any suggestions?

I can only find this video:
http://www.vimeo.com/5143080

[yipster]

the biodesign site has changed, but the instruction video works ok
have biodesign on my other computer becouse it dont run in vista

[susheng999]

I use maxsurf

[Jenny Giles]

I use Free!Ship and Michlet.

Has anybody here had problems with Free!ship exporting Michlet files?

It doesn't always work for me. Free!ship sometimes gives me a good Michlet file and sometimes it gives me rubbish if I use a different number of stations and waterplanes.

[thudpucker]

I gave up. I'm just not quick enough to learn that intricate stuff written in a strange vocabulary.
If I need a design, I'll post it and ask!

[sigfinity]

I have looked all through this board and read the postings. Lots of good comments. My experience is not much substitute for a good calculator or spreadsheet to get some basic constraints together, but designing a boat to me is new.

I have Alibre design for another project and was wondering why more commonplace cad applications got so little mention here.

Is it expense? parametric facilities? rendering? or xy table (output) file formats that makes these other packages more popular for designing a hull?

Sorry if this is a dumb question, just getting started and this is my first post thinking about a new cat project.

Thanks for comments in advance.

sig

[apex1]

Originally Posted by sigfinity

I have Alibre design for another project and was wondering why more commonplace cad applications got so little mention here.
sig

Welcome here Sig.

It´s not price, it is the lack of ability. Common CAD programmes are unable to draw a precise hull. Thats it in short.

[thudpucker]

Odd that they are not precise enough for you experts!
They are too tough for people like me to grasp. I'd be happy with enough knowledge to draw out what I'm thinking so I can plan on the material.
I get started, and then lost!

So I do my scribbling on Napkins!

[apex1]

Originally Posted by thudpucker

Odd that they are not precise enough for you experts!
They are too tough for people like me to grasp. I'd be happy with enough knowledge to draw out what I'm thinking so I can plan on the material.
I get started, and then lost!
So I do my scribbling on Napkins!

So do almost all of the pro´s! Do´nt laugh, thats a fact.
Have you tried my tutorial on Freeship?Step by step to design your boat!