Limit switch problem

[Clive S]

First of all many thanks for your prompt replies. The idea is to have a lower Z axis limit switch that is easily and quickly adjustable, more for safety reasons than anything. This would mean having both upper and a lower limit switches fitted to the Z axis whilst having a single limit switch on both the Y and X and using soft limits set in MACH3. Do you think that this setup is possible?

Possible but not practicable As Dean (Jazzcnc) has pointed there is no point in a -ve limit switch as you would have to adjust it every time you changed a tool etc.
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Regarding the single limit switches and using soft limits in my opinion that would be a dangerous way to go as the soft limits would only work after you have homed the machine also if you stalled a motor the soft limits would not be correct in that the DRO would then be false.
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If you only want to use one switch on X and Y then make it traveling with a target at each end.