Hi,
CNC is a learning curve, no doubt.
I have always maintained that a 'success, or otherwise, of a hobby is gauged by what you have to learn in the process of doing it'.
In this regard CNC has been a great hobby for me, I have had to apply myself to many different facets from design to machining,
and the list of things to learn seems longer now than when I started.
As far a limit switches and home switches go I would commend that you have separate homes and limits, but be aware very few
CNCers agree with me, most combine limits and homes with sometimes un-predictable results.
I prefer mechanical snap action roller plunger microswitches for homes, I find the natural hysteresis distinctly advantageous
in homing routines. Even without Index homing (if you use servos you will be able to explore this further) I achieve 0.02mm
repeatability. It is sufficient, so much so that I have not deemed it necessary to invest the required time and dollars into Index homing.
https://nz.element14.com/honeywell/bzc-2rq18-a2/switch-basic-top-roller-plunger/dp/1525198Note that home switches are not required to be at the end on an axis, they can be anywhere within the travel of the axis. There
is advantage in having it near the end but comfortably within the very end of travel. With roller plunger switches I mount
the switch parallel to the axis and the roller plunger is activated by an small aluminum (adjustable) ramp attached to the axis.
This means that under no circumstance can an over-running axis damage my switch by excessive over-travel.
I also had small mechanical (small=cheap) switches as limits on my mini-mill. I had not thought out the consequences of an
over-running axis and I managed to wipe some of them out. I removed them in disgust. I always meant to replace them....
but I've just never get around to it. With good home switches I find that Soft Limits are adequate, and I haven't crashed my machine
for several years.
My new build mill will have G0's of up to 25m/min and 75-100kg axes so I'd bloody well better have, and well thought out,
limit switches or I'm really going to screw up bigtime.
For limit switches economical proximity sensors are adequate. Hysteresis it not required or even desired with limit switches.
Given the speed and weight of my axes I may have to have both a limit (extreme) and a 'slow limit' just inboard.
In the event of an overrun the 'slow limit' would operate first and decelerate the axis and then should the extreme limit switch
operate, then Estop.
Don't be over concerned with work offsets just at the moment. The single best thing I ever did to my existing mini-mill was add decent
home switches. THEN and ONLY THEN do Soft Limits make any sense and likewise being able to save work offsets like G54 ONLY
make sense relative to a FIXED and REPEATABLE HOME location, ie home switches. If you fit decent home switches and maintain
good homing discipline when starting a Mach session that confusion will evaporate and you will look on in bemusement as others
struggle to control their machine without disaster striking because either they have no home switches or are ill-disciplined about
using them.
Craig