I have a KFLOP board and i'm using Mach3, other axis are working just fine but Z axis isn't. It's position doesn't even change when I try to do so on the Mach3 interface. This probably won't be enough for you guys to help so if you need any more info, just let me know and i'll deliver.

If it is not changing in Mach when you command a move then it sounds like the Axis is not enabled in Mach.
Not sure how you set up the axis with the kFlop but check you have the Z enabled in Ports and Pins.

Hood