View Full Version : Limit switches and Mach3

05-03-2013, 08:39 AM
I have an A4 machine which I am using to gain CNC experience. It has trapeziodal screws and the Z axis is a 10x2. This has stripped the thread twice on the delrin nut and I have just realised that it is probably due to the 2mm pitch thread not being robust enough to withstand the Z axis hitting the upper limit of travel. This was demonstrated when a faulty new keyboard (Thanks ASDA!!!) had a stuck page up key.

The question is - Can I configure Mach 3 so that the Inductive Home switch at the top of the Z axis also inhibits further upward movement ?

You may appreciate that I have no machine at the moment to experiment.


06-03-2013, 09:51 AM
Your lucky you had Delrin nuts has 2mm pitch screw gives very high torque and if it had been Brass nut then would have probably done more damage if decent sized stepper.

To answer your question Yes very easily. Just configure the Z++ Limit Input in ports&pins/Input signals to use the same pin number has the home switch.

Be aware.!! . . .Mach will watch the Pin when machines cutting or Jogging around and treat it has a limit switch but when Homing Limits are turned off.
This has nothing to do with your type or configuration of switch it's just how Mach works. This is what makes it's possible to use same switch for both Limits and Homing.