[Infr1234]

Excuse me, I'm experienced in 3d printing and want to broaden my production capabilities in a home workshop to be able to CNC small things from metal too. To this end I'm planning a 3 linear axis CNC mill build, I'm only really planning to make things out of aluminium not steel so hear that rigidity requirements aren't impossible for DIY built systems so long as one doesn't need a huge working volume (I'm looking at 10cm x 10cm x 5cm). But before I can start on that I need to work out my toolchain for toolpath generation.

For 3d printing Cura works great to turn stl files in to printer gcode, but I'm ofcourse now after something for generating subtractive gcode for a custom built CNC machine.

My requirements list may be a little odd, it is below:

1. Must run on Linux (I've been driven crazy by windows bugs in the past and banished that OS from my life long ago), Windows software which is known to perform well under the Wine compatibility layer is ok too
2. Must be able to generate toolpaths for imported stl files (yes, I know this is unusual, usually one generates toolpaths from imported parametric CAD type files, but I have a very effective (for the sort of shapes I produce) toolpath already in hand which is mesh model based and ends up with stl files or obj/dae if I wanted)
3. Must not be in any way cloud dependent (for operation or for any kind of software activation), must work entirely locally with no dependence on web infrastructure (I don't trust getting oneself reliant on a software tool like the ubiquitous Fusion 360 which can suddenly disappear any day, or be unavailable if one's connection drops out)
4. Free and open source, or atleast open enough in every practical sense

I have tried PyCAM so far but it is horrendously slow to process even a simple low-faces-count stl file, many hours of CPU time, and seems obsessed with using a surfacing pattern of cutting which clearly isn't rational for a lot of shapes. I'd think some sort of contour lines style cut would be a lot more appropriate (many of the things I'd wish to cut are effectively 2.5D with no sloping surfaces on them). I also couldn't see how one instructs the PyCAM software as to the sizing of one's CNC machine, and things like how big a block of metal is sitting waiting to be machined, and what version of gcode the machine "speaks".

Please can anyone give suggestions as to CAM software able to fit the 4 requirements I've listed.
Thank you

P.S. ALL the stls I'll be importing are guaranteed to be watertight, valid files

[peteeng]

Hi 1234 - Sounds like FreeCAD fills your list. Peter

[Infr1234]

Thank you for your recommendation. Can you point me to any good tutorials on using freecad for this process? It is a big program with lots of features so I'd need to see a guide to how to make this use of it. Also any guides on then integrating this workflow in to the gcode interpreting part of CNC machining, I understand that there are tools like LinuxCNC or GRBL which run as firmware on a CNC machine, any guides about how one sorts out settings when generating gcode in FreeCAD so that it will be appropriate to the machine's physical setup (steps per mm, ... and so on). Thank you.

[peteeng]

Hi 123 - Sorry I'm not a FreeCAD user but its open software and it looks like the community is quite large so start the journey at the freecad site and look at its getting started documentation. Its all there. Peter

FreeCAD: Your own 3D parametric modeler (freecadweb.org)