DXF Import into FreeCAD

Introduction

• This says that DXF importer is available in FreeCAD since FreeCAD 0.16
• For earlier verion, follow this importer installation: https://github.com/yorikvanhavre/Draft-dxf-importer

Practice

When selecting units in LibreCAD, select inches as the unit.

This is the Edit->Current Drawing Preferences window:

4" square with hole drawn in LibreCAD.

4" square with hole imported into freecad. Note that dimensions appear. The DXFs also appear as dumb objects, with dimenions - not FreeCAD editable sketches.

Bugs

FreeCAD thinks everything it imports is in mm. The CEB Press/Current Downloads files for the brick press from 2014 are in inch units - but LibreCAD dimensions are the same whether inches or mm - in which sense the LibreCAD files do not have an absolute dimensioning system. To allow for correct import to FreeCAD, the LibreCAD files of the brick press need to be scaled by a factor of 25.4 - the number of mm per inch.

Protocol for Converting DXF CNC CUtting Files into a 3D Object

• Check out Index of parts and assemblies
• Select a part that you want to do.
• Open original DXF cutting file of interest in LibreCAD.
• Isolate the component of interest in LibreCAD, and save as the corresponding part in Index
• Open FreeCAD and create new document
• Import DXF file that you created. Import lies in the XY plane. Set grid size to 1/32" or 30 thou, which is the required accuracy.
• Trace the DXF file in Freecad using the Sketcher workbench. Use the Polyline tool for contours, as well as other shapes as needed. Zoom in sufficiently such that When selecting a vertex, the quality control is being within a fraction of line separation from the actual point. This marks ~1/32" accuracy of the vertices.
• When finished tracing, go to the Part Design workbench and make a pad, 1/2", 1/4", or 1/8" thick. Or whatever the metal thickness is.