With the installation of encoder-disk position sensors, the possibility of a crash can be detected in advance and thwarted. Alternately, torque sensors can help determine whether a CNC machine is moving as intended and also detect unwanted cutting.
In garage CNC systems, tools are reliant on the rotational precision of stepper motors for the correct number of degrees. To monitor the tool position, the pulses that go to the stepper must be counted, because in most cases, there’s no form of alternate monitoring.
On industrial CNC machines, closed-loop controls are employed, whereby the control always knows the axis position. If properly controlled, the potential for crashes is significantly lowered, though it’s still the responsibility of programmers to see that codes are inputted accurately for utmost safety.
Over the last two decades, CNC software has advanced to where a vast range of machine tools — axes, clamps, fixtures, spindles, turrets — can be based precisely on 3D solid models. With those specs programmed into the code, it’s easier to determine whether a crash will occur with a particular cycle.