I'm running Mach3 to run a router. When I home the machine all axes move to the zero position with z at the top. When a program encounters a g28 g91 z0 (any time it needs a tool change for example) the z rises up to the limit switch but triggers an e stop rather than a limit and the program must be reset. Any guidance on settings? Thanks
You must also set up soft limits even though you have physical limit switches.
For home position, soft limits and limit switches are set identical - all set to zero.
For the other end of the x and y axis make the soft limits 1 mm before hitting the limit switches. I have remove the bottom limit switch for z and use only soft limit because z is always zeroed using the probe to the material surface and soft-limit can be easily changed to avoid cutting the table or even too deeply on the spoil board. It also helps if the auto Z probe fail.
I found that the presence of soft limits help avoid "e-stop" conditions. The limit switches if really triggered must "e-stop" to avoid physical damage to the machine.