Out of curiosity, has anyone ever ran an always on lever switch inline of the stepper motor so that when the switch is triggered it kills power to the motor before it makes contact?
Switching motors wires directly is a good way to kill your controller.
It’s best to have an emergency stop switch that kills power to everything.
Please forgive my ignorance, I am very new at all of this. If I were to install a set of switches at the upper and lower extremes of the Z axis that would stop current (ie break ground) when tripped, there could be the possibility of damaging the controller? I have an E-Stop but I would like to have something in place in the event my head is rectally inserted.
If you home your machine, you can use soft limits to avoid crashes and then you can set the maximum depth you will allow your Z axis to travel.
You can do hard limits by putting a switch at the top and bottom of the Z axis and configure grbl to stop if one of the switches is tripped.
Neither one of these options will cause any harm to your motors or the electronics.
I use an avatar for that exact condition!