Open Source CAD?

Mesh generators, CAD programs, and other tools
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Browser72
Posts: 1
Joined: 29 Dec 2010, 15:49

Open Source CAD?

Post by Browser72 » 29 Dec 2010, 15:54

I am just about to start using Elmer. I downloaded it from the Ubuntu package manager. (I converted to Linux only about 1 year ago.)

But, anyway, I realised that the Elmer program does not seem to have a feature to design even simple models. Is there a good open source CAD program I could use for at least 2d models? 3d would be helpful as well.

I'm a Mechanical Engineering student at the University of Washington and I would love to play with Elmer to test its usefulness to my studies.

Thanks.

janlietaer
Posts: 9
Joined: 18 Nov 2010, 23:26

Re: Open Source CAD?

Post by janlietaer » 29 Dec 2010, 16:04

Gmsh ( http://geuz.org/gmsh/ ) is basic but it works for small drawings
Jan

hazelsct
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Location: Boston, MA, USA
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Re: Open Source CAD?

Post by hazelsct » 29 Dec 2010, 19:03

I use FreeCAD http://free-cad.sourceforge.net/ to build 3-D geometries and export STEP format which ElmerGUI can read and mesh. (Be careful of units though -- you often get mm this way.) FreeCAD is a nice package, though not quite mature -- especially in the UI, and drawings really need a lot of work. But I absolutely love the Python scripting!

There are a couple of problems though: Elmer can only import and mesh a single body, and its meshing parameter control is limited. Salomé should be able to overcome both of these issues, but I'm having trouble getting its NETGENPLUGIN module to work in Ubuntu...

-Adam

mzenker
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Joined: 07 Dec 2009, 11:49
Location: Germany

Re: Open Source CAD?

Post by mzenker » 10 Jan 2011, 18:38

Hi,

if you want to mesh STEP data, here is (briefly) how I do it:

1. import the STEP geometry in netgen

2. launch the "healing" functionality of netgen (else you might have nonconforming meshes at the interfaces between adjacent bodies)

3. now, two possibilities:

a) create a mesh with netgen, save it in gmsh format (.msh)

b) export the healed geometry in STEP format, open it with gmsh and do the meshing there, save it as .msh

4. open the .msh file with Elmer, using "Coordinate scaling = 0.001" in the Simulation section (to compensate for STEP format being in mm).

Comments:

* If the variant 3a gives a satisfying mesh result: fine. If not, gmsh (variant 3b) gives a better control on mesh width etc. (or maybe I have not yet understood how to do that with netgen).
* Elmer CAN handle multiple bodies, at least if the mesh is generated externally.
* Though I use Linux at home, I have to use Windoze at work, where I do FEM calculations from time to time. So all the above is valid for Windoze. It may very well work under Linux anyway.

HTH,

Matthias

musquida
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Re: Open Source CAD?

Post by musquida » 12 Mar 2011, 08:54

I want to Study a Designing Software which one is good to study Auto CAD or ProE? I am a 4th Sem Mechanical Engg.Student and want to know which software wil prove better in getting good jobs in Future, please tell me which designing I should study in deep among Auto CAD and ProE.
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Last edited by musquida on 17 Mar 2011, 08:12, edited 1 time in total.

tcdonley
Posts: 10
Joined: 29 Jan 2011, 08:55
Location: Virginia, USA

Re: Open Source CAD?

Post by tcdonley » 13 Mar 2011, 06:03

In the future? Who knows? I studied Cadkey in college, and now Cadkey is gone. I work for a multi-national corporation which uses only AutoCad in-house (and I pray for my colleagues in Miyagi). You'll need to learn many softwares in your career, so if you want jobs, learn to use as many as you can! For CAD I mostly work from home using QCad, DraftSight, Alibre, and TurboCad for drafting, and use GMSH, Salome, and GiD (but mostly Salome) for pre-processing for numerical analysis. I like the open source QCad for all my 2D drafting, and only use the commercial software for 3D machine design, and conversion to AutoCad format to send to my employer for archiving. As you graduate from a University, it's probably more important to be proficient at learning software quickly, than to actually be an expert in any particular software. By the time you graduate, a new version will be out, and your next employer might use a version from 10 years ago that you've never seen, or something else you didn't mention like VariCad or SolidWorks!

Best wishes in your studies,

Tim D.

CADMitsy
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Re: Open Source CAD?

Post by CADMitsy » 07 Nov 2011, 18:01

tcdonley wrote:In the future? Who knows? I studied Cadkey in college, and now Cadkey is gone. I work for a multi-national corporation which uses only AutoCad in-house (and I pray for my colleagues in Miyagi). You'll need to learn many softwares in your career, so if you want jobs, learn to use as many as you can! For CAD I mostly work from home using QCad, DraftSight, Alibre, and TurboCad for drafting, and use GMSH, Salome, and GiD (but mostly Salome) for pre-processing for numerical analysis. I like the open source QCad for all my 2D drafting, and only use the commercial software for 3D machine design, and conversion to AutoCad format to send to my employer for archiving. As you graduate from a University, it's probably more important to be proficient at learning software quickly, than to actually be an expert in any particular software. By the time you graduate, a new version will be out, and your next employer might use a version from 10 years ago that you've never seen, or something else you didn't mention like VariCad or SolidWorks!

Best wishes in your studies,

Tim D.
Many apologies for the late response, but I've been looking for an open source CAD program for a while. I'm actually relieved to know that others are having the same amount of difficulty; because I thought I was going crazy! ;)

Anyway, I've been wanting to work with a CAD program for a while. 3D modeling isn't necessarily MY thing, but it can assist someone who's wanting to "create" a living space or building, if you will. After all, CAD (AutoCAD, in particular) is an architectural program. While I have a list of bank owned properties that I'm looking into (buildings/spaces that already exist), I would clearly need to do some remodeling to better fit our business' image. Do CAD programs allow you to create side-by-side models? I would want the old business model and another one to alter by comparison. Can someone help me out? Thanks! =)
A man who dares to waste one hour of time has not discovered the value of life.
Charles Darwin

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