Deepnest is Open Source Nesting Software

This starts with a sketch in FreeCad. Six simple shapes and a rectangle large enough to contain the shapes.  The container shape does not need to be a rectangle,  it could be an odd shape piece of material.  Export the sketch as dxf.  The shapes can not be inside another shape.  For example the rectangle on the right is empty.

 

The configuration settings in Deepnest.  I changed the Curve tolerance to 0.002".  Unfortunately Deepnest  tolerance doesn't work exactly as expected and that will be the topic of an upcoming post on arc-fitting.  Freecad exported the  sketch dxf in mm so that's chosen here as the import units.  The export setting is inches.  The Space between parts is set to 0.25" to match the diameter of the cutter.  There are mouse-over tool tips to explain the settings.

A true 2D drawing program like QCAD would probably be a better choice to create the dxf file.  Deepnest can also work with svg files.

Here the 4.4" x 3.6" rectangle has been chosen as the container.  Note the option to create multiples of the shapes.  All or none of the shapes can be selected and Deepnest will fit as many as possible.  At the bottom left (not shown) there is a small square icon that will create a container rectangle if none is included in the sketch.

 

 

 

 

This was the first and best nest.  Deepnest will continue trying new arrangements until the stop button is clicked.

  

This was the best of the alternatives offered.  Clicking on the colour bars on the left will display the various nests offered.

All that's left to do is exporting the dxf.  I find that FreeCad will not open this dxf correctly unless it is first opened and saved in QCAD.

In FreeCad import the dxf into Draft Workbench.  Choose "select all" from the edit menu.  Perform a Modification -->  Draft to Sketch.  Take the opportunity to hit the delete key to delete the associated shape entries while they are still highlighted in the tree.

In the Part Workbench select the sketch and extrude.  Create a cube to act as a base for the extrusion.  Then select everything and make a compound.

In the Path Workbench choose the compound as the model.  The tool is a 1/4" end mill.  The image on the right is the cut simulation and it looks okay.  The dxf from Deepnest returned all the original measurements for these simple parts.  The circle has become a series of line segments as you might expect from a dxf.  If the segments are short enough FreeCAD can output g-code containing G2/G3 arcs.  If the segments are too long the g-code output will be a circle approximation using line segments.  This is discussed further in a post labelled 'Arc-fitting and Arc-breaking with bCNC'