Linux CAD

All topics, except for ones related to water fights. Posts made here do not count towards your post count.
Locked
User avatar
SSCBen
Posts: 6449
Joined: Sat Mar 22, 2003 1:00 pm

Linux CAD

Post by SSCBen » Fri Sep 05, 2008 7:56 pm

If you don't run Linux or ever plan to this thread won't be very helpful to you unless you want some free CAD programs that work on Linux (both I describe can run on Windows, though it'll probably take some tweaking). Alibre Xpress is a good free 3D CAD program for Windows.

Recently I've been looking for a good free 3D CAD program for Linux. I was ready to hunker down some money for a more fully featured CAD program until I ran across GraphiteOne. The free version is a little old but still plenty adequate for what I want to do. I barely know anything about how to operate it but it should be more than adequate for what I want to do, and if it's not, I can modify the source code to do that I want (it's somewhat-free software).

For kicks I've attached a screenshot so you can get an idea of what it the program is like. The object shown is an air cylinder I bought off McMaster-Carr. GraphiteOne can import and export a good amount of file formats so I had no problem importing this.

I stopped for a while on BRL-CAD but there's a few reasons why I didn't like BRL-CAD. While it is a fully developed and workable CAD system, it's interface is rather poor and it's too complicated for my purposes. The main difference is that it uses constructive solid geometry (CSG) rather than the boundary representation (Brep) that most CAD systems use. Basically, you make objects by making combinations, differences, and taking what's common between basic 3D shapes. There's a few reasons why BRL-CAD uses that but none of them really apply to me, so there is no advantage to CSG for me.
Attachments
Screenshot-1.png

User avatar
cantab
Posts: 1492
Joined: Fri Oct 19, 2007 1:35 pm

Re: Linux CAD

Post by cantab » Fri Sep 05, 2008 9:19 pm

I know of QCAD and SagCAD, but haven't really used either, so don't know much about them. My guess however is they're more 2d programs.

Though, and I hope this isn't too dumb a question, what makes 3d modelling software, like blender, unsuited to CAD work?
I work on Windows. My toolbox is Linux.
Arsenal:
Super Soaker: XP215, 2xXP220, Liquidator, Aquashock Secret Strike M(odded), Arctic Blast M, CPS1200, CPS2100, SC Power Pak, 3l aquapack, 1.5l aquapack
Water Warriors: Jet, Sting Ray M, Shark, Argon M, Tiger Shark, PulseMaster
Others: Waterbolt, The Blaster, Storm 500, Shield Blaster 2000, generic PR gun, generic backpack piston pumper (broken), 3l garden sprayer M, 10l water carrier:

swirlycurly
Posts: 25
Joined: Mon Mar 31, 2008 11:23 pm

Re: Linux CAD

Post by swirlycurly » Fri Sep 05, 2008 10:34 pm

we have autocad 3d inventer 2009 or whatever year it is and we have only had three classes so far. I have no clue what i am doing with it and kids' computers crash all the time and it is just a mess. The computers are so small and weak they cannot even run it. Hopefully i will be able to figure it out after the course and be able to design stuff though.

User avatar
SSCBen
Posts: 6449
Joined: Sat Mar 22, 2003 1:00 pm

Re: Linux CAD

Post by SSCBen » Fri Sep 05, 2008 10:37 pm

QCAD is great for 2D, but sadly it doesn't have any 3D functions. I've never heard of SagCAD but I'll take a look at it.

There are actually tools to make Blender better for CAD. I've used Blender before. I'm sure Blender's fine for modeling, but it lacks some engineering-oriented features I'd want. I'd like to make technical drawings with measurements. I'd like to be able to spread all the parts out to cut out of plastic sheet. I'd like to (well, in the future) generate code for CNC machines.

From what I've read though there are some scripts for Blender to help with engineering applications. Using Blender for CAD isn't uncommon, so I'm sure people have adapted parts of it to work better in CAD.

WaterWolf uses Blender from what I can tell. Google Sketchup is popular on some woodworking and architecture forums from what I've seen too, mainly because it's easy to use. Sadly Sketchup isn't for Linux, but it runs decently in Wine.

User avatar
Silence
Posts: 3825
Joined: Sun Apr 09, 2006 9:01 pm

Re: Linux CAD

Post by Silence » Fri Sep 05, 2008 11:22 pm

Good thing Sketchup runs in Wine, because Alibre doesn't, according to AppDb.

Blender is to CAD as art is to engineering, from what I can tell. It probably doesn't simulate multiple parts very well (if at all) and, as Ben said, measurements may be difficult to do. There are lots of 3d drawing and animation programs - Maya and 3d Studio Max are used often for games, for example. And there are lots of technical CAD programs - like SolidWorks. But there *is* a good bit of a difference.

Ben, I think you'll have a tough time finding free industrial-quality CAD software (which obviously isn't necessary). Why? Because it's used by engineers and students at companies and universities, run by pointy-haired bosses who are eager to buy the latest $2000 software. With such a big commercial market there's not much demand for freeware. Ie, if you want the software, get it through UMD. Obviously there are illegal methods, too, but I won't advocate those.

Locked