1- Why I need to upgrade my Z axis?:
The simple answer is: RIGIDITY
Our Z axis replace all the X carriage, it is 3/8" thick instean a thin sheet metal.
2- Can I still use Carbide Motion ?:
Yes but your travel will be limitted, you can use Universal GCode Sender or an other software to be able to use all the potential of your new Z axis.
3- Can I still use my original Z stepper motor ?:
yes you can but you can upgrade to a bigger one like this one: 269oz-in
Maybe it's time to upgrade all your axis with this motor!!
4- How it is difficult to upgrade:
5- Do I need to change my GRBL settings:
Yes, here the basic one:
$3=2 ’ = change the direction of the Z motion
$102=200 ’ = Z axis travel in mm
$122=750 ’ = increase the z axis acceleration
6- What it look like when mounted ?: