[Tarakai]

Hello I am a new cnc'er here and I am trying to get an Arix cnc60 up and running.On the front left side there is a handle that freely rotates with a locking nut and guage showing marks down to .02mm. Underneath is a roller ball sensor that rotates whenever the handle turns.
Is this a Z axis back lash adjuster ? Is it also a manual z axis rotating arm that somehow lifts and lowers the deck ?

I have an operators and spare parts manual but there is nothing mentioned about the device at all.

Looking underneath the shaft runs at an angle towards the z axis ballscrew but it is hidden from view and visually obstructed by the internal casting.

Any help would be appreciated.

thanks Phil Lucas