I have a vmc190 from the mid 90’s and it as home switches on all three axis
I use linuxcnc but mach3 and 4 support soft limits as does linuxcnc

You home the machine so in G53 it knows physically where it is then the soft limits are applied from that known ‘home’ position
I personally set the soft limits 1mm short of the physical limit of movement on each end of each axis
As the home switch is already located at one end of the physical movement of that axis the soft limit is 1 at one end and 250mm at the other assuming that there is 252mm of axis travel before it hits something or runs off the ball screw

There is a tick box to ‘ ignore soft limits ‘ just in case you do get beyond the soft limit area so you can carefully jog back into the soft limit area. I’ve never needed to use this but noted that it was there.
In mach3 as you approach the soft limit boundary the speed is gradually reduced especially if you are jogging or moving at a fast speed
In linuxcnc it just stops at the boundary
I’ve found soft limits work perfectly BUT if your machine was to skip steps then the soft limit may not protect you from damage but if your machine is skipping so many steps then you have much bigger issues to resolve

I’m not sure about mach3 as I don’t use it much these days but linuxcnc (my go to machine control software) will detect that the gcode would exceed the soft limit area and warn / prevent you starting the gcode which is a real life saver on a small mill like the vmc190

Cheers. Paul


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