Let's Make Robots!

what cad tool?

SO I've recently got an UP 32 printer, but am not sure what application to use to model my new robot in - they all seem to have various advantages / disadvantages. The ultimate question for this topic is: What cad tool to use? Some of my findings are below but I've still not found something I'm happy with.

What I've learned is I definitiely need a proper cad tool that is focussed on building up engineering models, rather than artwork. I need it to be able to do csg, and have some basic idea of 'components' - i.e. building objects, then making bigger objects out of those etc. So far I've not actually printed much in the way of actuall robot parts.

3ds max:


  • lots of features and ways to create shapes
  • some suport for csg (although not reliable)
  • outputs lots of file formats


  • more of a modeller than a cad tool - very hard to get accurate measurements, sizes etc
  • csg doesn't work properly
  • so expensive I'd have to get a not-so-official copy

Via cad:


  • lots of shapes
  • good csg support
  • lots of videos to show you how to do things


  • poor ui
  • often confusing as to why a tool works in one place but not another
  • generally ropey implementation (unhelpful errors like 'zero rad.x' appear)



  • Very nice UI
  • Quick to build up basic shapes
  • Lots of premade models (like an Arduino Mega)


  • No CSG in free version
  • Seems to struggle with defining solid objects, so I suspect csg might not work well in the pro version anyway

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Blender ...... loads of support and heaps "How To" videos.

(initial steep learning curve...however easy after basics have been grasped)

Export/import STL , plus 3D model checking inbuilt.

Animation and Dynamic Game engines inbuilt. (and fun to use)

A new free CAD SW popped up.

Has anyone tried 'DesignSpark Mechanical' yet?

I've got frustratred with 123d I was using before and had a look at DesignSpark. It's based on SpaceClaim which is a serious CAD package ($2500), but also used in UK schools - My son uses it.  Unfortunately for the OP, no CSG handling.

DesignSpark looks like it's a collaboration with RS COmponents as it has full access to their parts libraries, but you are not tied to them in any way.  Very intuitive to use once you've got used to which mouse action does what but very powerful.  Check out the SpaceClaim tutorials on YouTube.

another free CAD package came to mind. BRL-CAD.

Has anyone tried Free-Cad? I've installed it on a linux computer, but it's an old machine (that's why I had permission to install linux on it) and therefore doesn't do 3d cad very well. It looked intresting, though. At the moment, I use Blender for any 3d cad that I do, but it is not really designed for it, and I'd like to have a try with a parametric modeler. Blender's a good piece of software, though.

... I have tryed, crashes randomly. I'm sticking to Blender for now. 

google "Solidworks torrent"

Just kidding, pirating is wrong...but really, nothing compares to solidworks. Solidedge is close, and Alibre Design is nice. But all the free programs I've used are a joke compared to these. (and I've used a lot of them).

... it's a modeler and it does not do CSG very well but I have grown fond of it since a long time ago. I used it to design a lot of stuff, it works for me, YMMV. The only drawback of using a modeler for your designs is the non parametric part of it, so if someone want's to change the model they need to edit the mesh. It is possible to do parametric stuff using it's python api but I never really got into it so far. OpenSCAD seems to be the standard way, though I find it challenging to use and it has it's own fair share of bugs. Regarding FreeCAD it's going to be nice when done, currently is quite unstable at least on Linux. The same goes for HeeksCAD and most OpenCascade based software.

Thanks guys - downloading 123dapp and openscad now



I have no experience with FreeCAD. OpenSCAD seems useful for a programmer, because, the models are built from coded parts rather than selecting and drawing models. There is an issue with the way OpenSCAD deals with variables. I don't recall what it is exactly, but, it has to do with "I think" a variable 'i' in one function will retain the value if you use 'i' in another function. Even though, you didn't pass the variable 'i' to the second function.

I know there are thousands of models on thingiverse that were produced with OpenSCAD.

Just for reference, here http://www.thingiverse.com/thing:15370 is a link to the most 'impressive' model I have made with it so far.