Setting up soft limits in UCCNC .. "Logic"

[JAZZCNC]

Neale,
I'm not going to argue with a word of this, and I am coming at it from a wood-working gantry router perspective which is different to a mill. Like you I often reposition the work coordinate zero to suit the job but this will be a known position relative to the homed (0,0) position so that it can easily be re-acquired after an E-stop or other driver-disabling event.

Kit, you don't need to position the work to a known MACHINE location to get back to WORK ZERO that is the point of the G54, G55,etc WORK OFFSETS and using HOME switches. If you get lost or crash the machine you simply HOME the machine and it uses the WORK OFFSET to get back to WORK ZERO.

The only thing you may need to do is save the WORK OFFSET before starting the job just in case power goes off mid job. However some controllers save the WORKOFFSET before the start of the job, I think Linux does this and UCCNC but Mach3 doesn't which is a pain as it's easy to forget.

Regards Backing off the HOME switch then the only point to me, other than to relocate MACHINE ZERO position is to stop potential false trips if using same switch has limits combined with homing or to square a dual motor gantry.