what CAD software out there would be the best for cat design? When you buy the software do it come with a manual that tells you how to use it?
regards Tom

This topic has been discussed before in a previous thread. SOME people maintain that the BEST method of designing a cat from scratch is pencil and paper, while others amongst us agree that Solidworks is probably your best bet as far as CAD for cats :P

http://www.catsailor.com/forums/sho...ew=&sb=5&o=&fpart=1&vc=1

I am seriously think of purchasing maxsurf design software because of the good reviews. When I look at the prolines design software, I think it preety good alround with reasonalbe prices but people have said it not they good. any comments?
regards
tom

Tom,

I have been using Maxsurf last year and it is a good hull desing software. It's optimized for building commercial crafts and the speed prediction program (hullspeed) will not work for a cat.

You will also need a real cad program to produce the plans and to work with the lines. We were using autocad to produce the plans and we used rhino3d for part of the work as well.
Solidwork is not necessarly a good choice. While it is a good solid modeling software, part of the work to produce the hull is the calculation of the hull stability and buoyancy. I did try to use Surface work marine but I have a busy schedule at this time and no real need to design a hull at this time (hopefully this will change soon)

I did have a look at polycad http://www.polycad.co.uk/ and it looks good to me The only problem is the lack of manual with it.

As far as designing a hull, most software are surprising close to the paper and pencil methode so you could get a book on hull drawing or on naval architecture and the hull designing process will be compatible with most of the Hull design software.

As a last comment, the Tornado catamaran is still the fastest cat in the 20' range and it was designed over 30 years ago with pencil and paper.

Charles Leblanc
Nacra 5.2

The only reason why I'm considering purchasing CAD software is because all the most successful companies in the world, whether it is to do with yachts or to do with cars are using Cad software. I also understand that most of the modern catamarans are designed using CAD software. So if these companies that have turnovers of £500 million, then they must be doing something right!How much did you pay for your maxsurf software?
tom

Based on recent experience (building a cat) the biggest advantage of using CAD software is the ability to make patterns to build the boat by. A good CAD/CAM program can output paper patterns to cut things out.

Most of the calculations provided by commercial design software can be duplicated by an EXCEL spreadsheet and a couple of books on the subject. The advantage of doing it this way is you will have a better understanding of what you are doing.

If you already have EXCEL or it's equivalent, you can start cheap by using equations and designing the hulls numerically. You can then draw the design in section views using the plot capability. For better drawings or 3-d pictures most CAD programs will accept numerical tables as inputs. In analysis it is the numbers that matter, the drawings are for presentations and construction.


None of the commercial PC based programs, that I have seen, even approach industry state of the art. If you look around you may find surplus UNIX workstations loaded with obsolete all in one (CAD, CFD, Dynamics, etc) software. I bought an old APOLLO computer like that once. Be very very careful about advanced software. Make sure a license is included. Companies control it as "Trade Secrets" and Governments control it as tools for designing military hardware.

Good luck and have fun

I do not agree, the companies are sucessfull because of the draftpersons and engineers behind the computer. It takes months to to become efficient with a specific CAD software and it is still the person behind it that will draw the boat.



Maxsurf was purchased by my naval architecture school last year. Before that we were using AutoShip 1988.

The hull design process that I used is to find out the requirement for the boat and to find the main dimension. Once this is one, you can try to find a reference hull or build a simple hull using 3 mastercurves. After, it is a matter of refining the hull. Maxsurf is limited to six surface so you will need to use another cad program to produce the fabrication drawings.

Using excel to design a hull is possible. You have to use a drawing program of to draw the hull to scale on paper. After, you can take some measurement on the drawing and perform the calculation for the stability, buoyancy and even speed prediction. After that it is back on the drawings to refine the shape of the model and it back to the calculation. It takes some time but it is the best way to optimize the hull.
Right now at work I am working with autocad for the drawing of my current project and Excel for weight, buoyancy and stability. I wish that I would get my hands on maxsurf but I have to work with the tools I have.

Charles Leblanc
Nacra 5.2

I have always found the "old" power draw cad excellent, I have upgraded to POWER CADD and that is even better. I do all my 3D (shaping, testing, and rendering) work in Mac surf and have used it since 1989, I have found it to be "EXCELLENT", far and away better than the next - distance - 2nd best. BY using power cadd to draw out a cat hull in conventional plan elevations and perspective it gives me great results and I can loft from those drawings enabling me to set out and construct the boat/hull.

I have also been using Excell for many years, and I have found that unless you are "expert" in the use of it, then to try designing hull forms is extremely difficult. As compared to a CAD package such as Mac surf and or Power Cadd, Excell is like going back and navigating your way through dos directories with the key board, as compared to point and click for a Macintosh! both do the same or similar jobs but the point and click was always much easier and infinitely quicker.

Ohh and please pardon my spelling - MAXSURF - its because I use it on a dual processor G5, with 23" flat LCD screen, Macitosh that I seem to always spell it maC

Charles,
What software would someone purchase for designing the hull of a 5m catamaran?
regards Tom

by the way, does anyone know where I could buy yacht design equipment from e.g. ducks + a spline, Templates - used for drawing line with large curvature etc.
Tom