My Plan

Ideally, I would like to drive my CNC Machine from an Arduino UNO running GRBL so I can get a lightweight, low cost solution that I can plug into a USB port on a laptop or Mac. I know only a little to start with on grbl - but my understanding is that it is a g-code interpreter running on the Arduino, and doesn’t need a lot on the PC driving it.

I know that in most cases I’ll be designing my things in a CAD app, exporting to STL, then generating gCode, and this would apply on the Mach3 + windows, LinuxCNC or GRBL route.

My understanding so far on the Mach3 setup is that it would need a dedicated computer with parallel ports that is not allowed to run other apps at the same time. LinuxCNC may be marginally better on performance in this way. Somehow the Arduino version sounds tidier, and getting it working and well documented would lay down groundwork for others to follow.