Freecad CNC toolpath from SVG

Importing an SVG file to Freecad and creating a toolpath for the Kinetc CNC

The Sketch workbench in Freecad is the more usual way to create the shapes that will form a part in Freecad. The drawing functionality is more limited than 2d tools like Inkscape and it might be preferable to import 2d SVG shapes to construct a part. (This guide is based on experience using v0.19 on a Win10 machine, as Freecad is developing it's very likely that your mileage will vary.)

Prepare the SVG file in Inkscape

Create the shapes you want to import in Inkscape and make sure they are all paths, make sure paths are closed loops. Set units to mm in document and resize page to drawing (Ctrl + Shift + r) The Freecad import process will use the top left of the page as the origin so you want the page size to fit the drawing size to make setting origins easier in Freecad. If you encounter scaling problems there is a suggestion on the Freecad forums that setting line width of zero is required. This hasn't proved necessary but might be useful if there are issues.

Import the paths to Freecad

• Open Freecad and open the SVG file created above, select 'SVG as geometry'.
• Each shape in the SVG will be imported as a separate object, hover over them in the combo view and they will be highlighted.
• Switch to the 'Part Design' workbench and 'create a new body'
• Change to the 'Draft' workbench.
• If you need to move the origin, select all and use the 'Move' tool from the Modification menu.
• Select the shape that will be the outline of your part and convert it to a sketch. (Modification -> Draft to Sketch)
• The sketch will appear at the bottom of the list view in the 'Combo View' window.
• Switch back to the 'Part Design' workbench.
• With the Sketch connected create a 'Shape Binder' from the 'Part Design menu.
• This 'Shape binder' will appear under 'Body' in the tree view. Select it and use 'Pad' to give it a thickness.
• Adding other shapes that have been imported can be achieved in a similar way. In 'Draft' convert the shape to a sketch. Switch back to 'Part design' and select the new sketch. This time use the 'Create a sub-object shape binder' to add it to the body. Use this new shape binder to create holes, pads etc.
• There are many more options for attaching sketches to the body on different faces or planes. Feel free to update this page with what you discover..

Create the Gcode

• Open the 'Path' workbench and select 'Job' from the 'Path' menu.
• On the 'General' tab you can give this job a name and description.
• In 'Output' provide a filename for the Gcode, this should end with the extension .nc
• Select the 'KineticNC' processor from the dropdown list. NB you will need to copy this file into your macros folder and restart FreedCAD to install the postprocessor for the DoES KineticNC mill.
• The 'Setup' tab lets you define the size of your stock and (in theory) determine where the origin is.
• The 'Tools' tab is where you add and define the different tools you are using for this job. Set the tool dimensions and feedrates here.
• Click 'OK' to setup this job.
• Cutting paths are defined by selecting the face(s) or edge(s) you want to use and selecting the operation (Profile, face, drill, pocket etc) from the 'Path' menu.
• These operations each have their own parameters to set, see https://wiki.freecadweb.org/Path_Workbench#Basic_Operations for more details.
• Clicking 'Apply' in the operation window will show the generated path in green in the main window. Clicking OK will apply the operation and close the dialogue window. As you add operations they will be listed in 'Combo view' under 'Job -> Operations' in the order you create them.
• Optionally you can dress up paths to add things like tags to your toolpaths. Select the Operation you want to modify and then the dress up option from 'Path -> Path dressup' menu.
• Once you are happy with the operations use 'Path -> Post Process' to generate the gcode file.

Caveats

As described above this is a workflow that has worked for v0.19, as Freecad develops these instructions are very likely to need changing. If you discover errors, or better ways to achieve the above please add the information here :)