You can succeed using .DXF and Inkscape. But, there are better approaches to consider.
As a ’Partial’ example of DXF/Inkscape success, below is screenshot of Opening a DXF in Inkscape and using the Gcode Extension to create the Gcode for machining.
It’s been a few years - old memory suggests you’ll need to dig into it but, it was fairly easy after headaches of learning the tricks (mostly with Inkscape).
Better Option(s):
Option 1) I do it this way.
Create the PCB design in Fritzing, Export Gerber files and load into CopperCam. Export the Gcode for machining. Simple. See comments below…
Option 2) Using a DXF, import into FreeCad, Export the Gcode. I have done this many times (mostly for non-PCB work) but don’t recommend it as it requires learning FreeCad.
Pretty easy for a SolidWorks user (the Part Design Workbench is similar enough to SolidWorks to make it Very doable in a couple of hours. I no longer use SolidWorks or ProE as FreeCad has matured to Professional usage.
It will be confusing, especially learning/working between the various Workbenches (Part_Design, Draft, Part, Path. Think of them as Individual Programs under one Umbrella called FreeCad).
Option 3) Using Eagle and plugin, you can do it all but, steeper learning curve.
Option 4) KiCad is like Eagle - but, has it’s own Stand-Alone programs (PCB, Schematic… etc) under the one umbrella called KiCad. I’m not sure about KiCad and Gcode, though in the past few months I’ve gotten quite familiar with KiCad. I use it to create the Gerbers and CopperCam for the Gcode.
The UpShot…
The most efficient and 100% success rate (without steep learning curve) will come from using Fritzing and CopperCam (or other Gcode from Gerber making program).
CopperCam has a Free download good for small projects. Link
Regarding Bowing/Non-Flat PCB’s:
I used 3M double-sided Tape. That worked well but eventually machined some holding frames… screenshot below…
