Z Axis calibration

Hi Guys,
Just need a bit of help with the Z axis. It not a little out as the X and Y axis
were which i have altered but its a long way out and the distance its out
is not the same moving up or down.

Many thanks.

I was having the same problem I was able to fix it by checking the steps good video on U tube using a volt meter and after that u can check the cali: in mm and make final in the gbl code.

Many thanks Bob i will try that.