Exporting a DXF from FreeCAD will require some additional setup: FreeCAD Wiki: Draft DXF and DXF Export in FreeCAD
FreeCAD can be challenging to export two-dimensional DXF files from since it requires add-ons. Check out our recommended software to see if other options will provide a smoother workflow.
After exporting, you can upload your file to our website and check the part preview to verify that the overall dimensions are correct. All files need to be at 1:1 scaling in either millimeters or inch units, with no intersecting or duplicate paths. We have more information about our design requirements here: SendCutSend Design Guidelines
For general preflight, the free, open source program QCAD is great for checking 2D files. If you end up liking it, we have guidance on reviewing designs in QCAD here: How To Preflight Your Designs Using QCAD
