Z axis in GUI

Dont know if this is the right place to put this so I apologise if its wrong.

Finally getting to set my home made machine up after blowing up many drivers and things and getting the homing sorted out. It sort of homes but throws a switch error before back off move unless axis is very close to home switch location. Had a look on the net and it might be that my home speed is too high presently set at 0.5mm so I'll try a lower figure tomorrow.

The main problem/ annoyance I have is the Z axis, it moves in the right direction to home when commanded from the homing sequence but the direction in the GUI is opposite. When I run the linuxcnc Gcode the Z axis moves oposite to the GUI, when the GUI shows the tool moving towards the work surface my actual Z axis is moving up. I have tried inverting the step and direction as well as reversing the settings for the axis in the stepconf wizard bit it made no difference.

What is the best way to configure the Z axis, 0 at the table or 0 as far from the table as you can go in my case 80mm? I must confess for some reason the Z axis really confuses me.

Bill

The actual position of Z 0 does not really matter. What does matter is that up is the positive direction and down is negative. Normally most machines have the machine Z 0 at the top of travel, and all movement is negative from there. You then use work coordinates and or tool offsets to set Z 0 to either the work or table surface. So on your machine Z0 would be 80mm away from the table and Z-80mm would be head crashed into the table.

In addition take a look here...
www.linuxcnc.org/docs/html/config/stepconf.html

Leadscrew Pitch - Enter the pitch of the leadscrew here. If you chose Inch units, enter the number of threads per inch If you chose mm units, enter the number of millimeters per revolution (e.g., enter 2 for 2mm/rev). If the machine travels in the wrong direction, enter a negative number here instead of a positive number, or invert the direction pin for the axis.

Rick G