My contribution
I designed and built the controller around the operator, not the machine: the preflight logic, the datum guard, the screen layout and the remote watch view. Every feature traces back to a real fault I hit while commissioning and running my own CNC router.
The problem
Standard CNC software sends the job and leaves the operator to spot the mistake, usually when the cutter is already in the material. A file that runs past the machine's travel, or a machine that quietly loses its work position, can ruin a part and the stock with it.
How it works
Before every run, the full toolpath is checked against the machine's real travel limits, and any job that would run off the bed is refused with the axis and distance shown. A datum guard watches for lost work position. A live 3D preview, spindle control, saved positions, calibration and job history sit on one screen. A direct USB link carries the job, while Wi-Fi lets a phone or tablet follow progress.
What it delivers
A controller built around the failure rather than the normal run. The recorded preflight scene shows a real out-of-range job being stopped before anything moves, with the exact overrun reported for each axis.
Where it stands
Implemented software. The recordings on this site come from a test environment with the machine disconnected, so they demonstrate the logic, not cutting accuracy.
How the preflight check decides a job is unsafe, and what the operator sees when it does.