Add Mechanical Gantry Calibration G34 for users that have dual Z on ender 3 4.2.2

I added z-axis to my ender 3 using a 4.2.2 board. I was wanting to make sure the axis was level but I don’t see G34 as an option for either the firmware builder or in the prebuilt builds.

Since you are using the original 4.2.2 board, you cannot use G34 as it doesnt control each Z stepper seperately, it just sends them the same signal so they move together.

Doesn’t need to have an additional driver as it is mechanical.

I need to look into this - as I also need to understand what safety requirements also need to be set.

I’d hate to enable it, but not have the right knobs to tweak and end up damaging peoples printers…

Sorry for the delay in this - but G34 Mechanical Gantry Calibration is now available in the Firmware Builder.