For supplementary motorization of the Z-axis, the focus drive MA 42E is installed by removing the fine focus knob from the microscope and fixing the MA 42E, in conjunction with a special coupling, directly to the shaft of the fine focus. This method prevents any slippage or loss of steps.
Where this is not possible - due to the design of the microscope - the drive ensues via a friction pulley, positioned on the fine focus knob.