I have the part and holes all exported from my OnShape program but the CAM programs I am trying see it as a whole piece. Drill 3 holes with CNC that are accurate and then 2 cuts through the sidewalls. I'd like to clamp the U-Channel in my vice and jog to (about) the center of the piece. I have a simple U-Channel of aluminum and I need to accurately reproduce holes in many of these parts. So here's an example of a real project need. With my CNC mill I'm sort-of left with a gap. With my 3D printer stuff I merely extract the part I want slice it up and print it. I have done quite a bit of work with 3D printers and am becoming pretty good with that technology but that's additive and this is subtractive. But I want to take the next step and start learning how to go from those parts in CAD to a real part or tool-path in CNC.

Now I have a good CAD program (OnShape) that I can use to make accurate 3D parts and extract them.

ngc files from other people and was doing some rudamentary raw gcode myself to do very simple jobs. So I have used LinuxCNC for a few years though I was using it ONLY with pre-programmed.

Free cnc cad