Best CAM options

[byersa]

After decades away from the machining world I am getting back into it. I have a home-made 3axis CNC router table running FlashCut and am interested in making jewelry molds - so a lot of curved surfaces. FreeCAD seems like a good option for me as I know the Python language and like the idea of doing a lot of work with scripts. I guess what I want is the same functionality found on http://www.vectorart3d.com/, but with more control and ability to create my own models.

So one question is what would be a good CAM companion to FreeCAD. I got here from investigating HeeksCNC which also uses Python.

The other question is what mode is best for modeling from a CAM point of view - meshes or 3D objects? Do some CAM packages work better with one versus the other or do they all mostly need or work better with one approach.

Thanks,
-Al

[aj5robinson]

Hi Al,

I don't know the answer to your questions but you might have some luck on the #cam and #freecad irc channels at freenode.net.

So one question is what would be a good CAM companion to FreeCAD. I got here from investigating HeeksCNC which also uses Python.

I will answer this with obvious bias. The forthcoming FreeCAD Cam workbench that we are developing; this, incidentally, will borrow at least the post-processor from HeeksCNC. It is presently very early on but hopefully we can have some basic functionality in the coming months.


Cheers
Andrew

[turkishviking]

Hi Al,

I'm new on this forum too and like you I'm working on a home made cnc (with a friend), i'm trying to calculate the Tool Path with a python script and freecad. we have the same problems and the same goals

I can told you a part of what I think for now:

The other question is what mode is best for modeling from a CAM point of view - meshes or 3D objects?

Hmm it's a difficult question that i am a little headbanging to solve, for me the goal is to work with meshes because it's a universal format and give access to more complicated geometry, but there is some difficulties:

• -1) meshes are triangles bag, we need to order them (a face can be described by a lot of triangles, the script has to know the links between them)

• -2) meshes are "2.5D objects" you can't know where there is some material, and where there is not.
  Some files have a normal vector associated to there triangles (like in .stl or .obj) but even with this formats, it's not always the case. It depend how the meshes are made (for example if it's come from a scanner, you have a points cloud, even if you make a mesh with it, you won't have the normal vectors to the faces).

The solution for this problems could be to transform the .stl in........ 3D Object?!
Freecad can make it, So I suppose that my answer is to work with 3D object

Now you would laugh with this thought: The problem with 3D object is than it's much more complicated to work with (open a .step file of a cube, you will see what I mean )

All that think brought me to think 2 solving ways:

• First way:
  • -1) To transform .stl in 3D object
  • -2) To transform 3D object in .stl #----- (to have the normal vectors) -----#
  • -3) To transform the .stl in a own format (each face described entirely with all there points and there vector) #------ To simplify the calculus later--------#
  • -4) To approximate each face with rectangles #------it will be the future tool path, the rectangles height come from the tool------#
  • -5) The direction of machining would be chosen by the user with a little GUI

• Second way:
  • To use what's existing like HeeksCNC but I'm working with 5 axes....
  • Working with 3D parts from freecad and access to the parts geometry directly (I have to learn how freecad stocks it)
  • make the above steps 4) and 5)

• An alternative way would be to convert directly the .stl in a format which describe all that we want (vectors, links) and to work with that to make the steps 4) and 5)

As you can see I don't know how really to make it

What you can make if you want to script is:

• -To fork the repository https://github.com/mrlukeparry/FreeCAD_sf_master.git

• -To clone it in your computer

• -To git --track the Cam-py branch

• (you can find more information for making the above task in viewtopic.php?f=15&t=3225&p=25158&sid=9 ... 486#p25158

• -To compile the program (see: https://sourceforge.net/apps/mediawiki/ ... pileOnUnix if you are on linux (if you aren't there is others tutorials on this website)

Note: in " .../FreeCAD_sf_master/src/Mod/Cam2/App/PyTPG " you can find a readme which explain how to build your own TPG (Tool Path Generator) using Python and linked with freecad .
The buttons in CAM module are not linked yet with your future TPG, Andrew is making a great work, it will possible soon, thanks to him!

I'am regularly on the IRC Channel if you wan't to talk about that, it will be with pleasure, like with anyone else!

I hope that it can help you

Charlie