CAD

CAD, Computer Aided Design, helps you draw things to scale for use in designing houses, furniture, surgical instruments, anything you want. There are lots of drawing programs to help you sketch your ideas but they fall down when you want to add specific measurements and angles. CAD lets you enter precise measurements and adds a variety of calculations, including areas. All Draw and CAD programs work in 2D plus some work in 3D and some add lighting and shading. Here are open source CAD programs you can use for free.

I started looking at CAD software again because I have to design a kitchen. There are a number of reasons for using software instead of paper including the ability to creat multiple variations without redrawing the whole page. 3D CAD will let me cover the vertical aspect of the kitchen in the same drawing. If the CAD allows variable based drawing, I can set a dimension, perhaps the cupboard depth, as a variable I can change whenever I like and have all the cupboards change at the same time.

Linux, Windows, anywhere

Archimedes

Read about Archimedes at www.archimedes.iv.org.br. The development started in Brazil and the occasional page is in Portuguese. The good news for Architects is the development is aimed at Architects. The bad news is it is written in Java and still a long way from replacing to top proprietary product.

That Java restriction is a worry. First Sun owned Java and now Java is in the hands of Oracle, an even more powerful reason to not use Java. Fortunately there is an open source alternative to Java under development. If Archimedes works on the open source version of Java then Archimedes can truly be called open.

BRL-CAD

BRL-CAD is the 900 pound gorilla of the open source CAD world. 20 years of development. Runs on computers you never heard of because they were used back before we were born. Download BRL-CAD from brlcad.org.

BRL-CAD started life as a tool for the American military and was made open source back in 2004. Lots of work produced a collection of applications that can perform solid modelling, ray tracing and other complex functions. There are features for designing electronic circuits and other specialised areas.

CADEMIA

I hate people using all CAPS for no reason. CADEMIA is written in and totally dependent on Java, runs on Windows, Mac, and Linux, plus has a stupid all CAPS name. CADEMIA uses the GPL license and has a facility for adding plug-ins.

Cademia has an add on module for structural analysis of beams.

The screen shots of Cademia show 2D designs, not 3D.

There is a generic version for everywhere, special versions for Windows and Mac but not the Mac Mac, only the Intel PC clone version of Mac. Cademia announced a future professional that will probably cost money and restrict the features they will put into the free version.

FreeCAD

FreeCAD is a nice looking choice for modelling in engineering and might be a touch complicated for designing your kitchen. There is a 2D sketching module under development for quick drawings of kitchen floor plans and equivalent. You can then draw your basic ideas and develop them into models later.

Here are the opening paragraphs from the FreeCAD Web site. If one of those abbreviations makes sense to you, you might want to try out FreeCAD. That is one huge advantage of open source, you can try before you buy for as long as you want.

FreeCAD is a general purpose Open Source 3D CAD/MCAD/CAx/CAE/PLM modeler, aimed directly at mechanical engineering and product design but also fits in a wider range of uses around engineering, such as architecture or other engineering specialities. It is a feature-based parametric modeller with a modular software architecture which makes it easy to provide additional functionality without modifying the core system.

FreeCAD is based on OpenCasCade, a powerful geometry kernel, features an Open Inventor-compliant 3D scene representation model provided by the Coin 3D library, and a broad python API. The interface is built with Qt. FreeCAD runs exactly the same way on Windows, Mac OSX and Linux platforms.

Get FreeCAD from sourceforge.net/apps/mediawiki/free-cad/index.php?title=Main_Page.

OpenSCAD

Thank you to Mark for mentioning this one. OpenSCAD is for the programmers out there. OpenSCAD draws diagrams from a script or a drawing file. There is no interactive editor. You could create an application to generate the script then use OpenSCAD to draw the result. You could add the OpenSCAD processing to a Bill Of Materials Processor or replace an SVG generate/render with the OpenSCAD script and render software.

The script is written in a command language that could be read by someone who understands PHP and similar languages. Here is an example from their documentation. The main differences from PHP are the variable names, i instead of $i, the specification of ranges, [0:5], and named parameters r = 1.

for ( i = [0:5] ) {
  rotate( i*360/6, [1, 0, 0])
   translate( [0, 10, 0] ) sphere(r = 1);
}

Linux

QCAD

QCAD is a commercial 2D CAD application with a free community edition available only as source code for Linux.

Maybe one day

avoCADo

avoCADo is an open source 3D CAD from http://avocado-cad.sourceforge.net/ and is stuck at a preAlpha stage from 2008.

PythonCAD

Read the PythonCAD documentation at pythoncad.sourceforge.net/dokuwiki/doku.php. If you are a Python programmer and want to use CAD, the choice is PythonCAD or FreeCAD because you can create your own extensions. The documentation for PythonCAD shows only primitive command line operations. FreeCAD is the better choice.

SagCAD

SagCAD is developed in Japan and available at sagcad.sourceforge.jp with documentation in English, Japanese, and German. SagCAD produces 2D drawings and works with SGY, DXF, IGES, and NC files. The original developers are Yutaka Sagiya (kappa) Sagiya Metal Mold Factory,Inc. and the Yoshimune Kobayashi Kobayashi architectural design office mosoku. The two example drawings in the documentation show the architectural use and the metal mold use, in this case a space shuttle.

One immediate advantage for Japan is the Japanese documentation. The English and German versions are mechanical translations from Japanese and some parts are not translated.

SagCAD can produce numeric control files for machines.

Sailcut CAD

Sailcut CAD is an example of a highly specialised CAD program, in this case designed purely to draw sails and mark up cloth for cutting into sails.

Static Free Software

Static Free Software, www.staticfreesoft.com, produce Electric VLSI Design System, a CAD program for designing VLSI, Very Large Scale Integration, silicon chips. The application was written in C but is now downgraded to Java.

You get the source code for free and there is a charge for the binary versions. Given that Java is supposed to be interpreted source code, the binary version should be the same as the source code version.

Varkon

Read about Varkon at varkon.sourceforge.net. The documentation suggests a primitive product. The documentation mentions a ready to use binary version but the source code is offered for download.

Open source version of Java

Apache Harmony is an open source alternative to the Java Platform Standard Edition and is developed by the Apache Foundation, creators of the Apache Web server. There is a working version to replace Java 5 and a start on a Java 6 version.

Most Java applications specify Java 5 as the minimum version and Apache Harmony should be close to working for some applications. The Apache Foundation place a strong emphasis on their Java based Tomcat extension to Apache. I guess their Harmony will work first for Tomcat and then be developed for the rest of the world. I will try Apache Harmony with jEdit and similar programs.

GCJ is a compiler for Java and should make some Java applications faster.

Kaffe is an open source replacement for the Java run time virtual machine and is still a work in progress.

The Eclipse project started a Java run time replacement project using one of their existing run time projects.

Conclusion

FreeCAD looks like the best starting point for serious CAD work with BRL-CAD the next choice if you work in one of the areas not covered by FreeCAD. When FreeCAD have their Sketcher working, FreeCAD might be the choice for designing kitchens.